Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
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43712 Publications
X-ray absorption spectroscopy reveals the transient oxidation state during microbial uranium(VI) reduction by a sulfate-reducing microorganism
Hilpmann, S.; Roßberg, A.; Steudtner, R.; Drobot, B.; Hübner, R.; Bok, F.; Prieur, D.; Bauters, S.; Kvashnina, K.; Stumpf, T.; Cherkouk, A.
Abstract
High-energy-resolution fluorescence-detected X-ray absorption near-edge structure (HERFD-XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy was used to investigate the reduction of U(VI) by the sulfate-reducing bacterium Desulfosporosinus hippei DSM 8344T, confirming the partial reduction of U(VI) and the presence of U(V).
Keywords: uranium(VI) reduction; sulfate-reducing bacteria; HERFD-XANES
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Contribution to external collection
in: ESRF Highlights 2023, Grenoble: European Synchrotron Radiation Facility, 2024
Downloads
Permalink: https://www.hzdr.de/publications/Publ-38242
Resonance-Based Sensing of Magnetic Nanoparticles Using Microfluidic Devices with Ferromagnetic Antidot Nanostructures
Dowling, R.; Narkovic, R.; Lenz, K.; Oelschlägel, A.; Lindner, J.; Kostylev, M.
Abstract
We demonstrated resonance-based detection of magnetic nanoparticles employing novel designs based upon planar (on-chip) microresonators that may serve as alternatives to conventional magnetoresistive magnetic nanoparticle detectors. We detected 130 nm sized magnetic nanoparticle clusters immobilized on sensor surfaces after flowing through PDMS microfluidic channels molded using a 3D printed mold. Two detection schemes were investigated: (i) indirect detection incorporating ferromagnetic antidot nanostructures within microresonators, and (ii) direct detection of nanoparticles without an antidot lattice. Using scheme (i), magnetic nanoparticles noticeably downshifted the resonance fields of an antidot nanostructure by up to 207 G. In a similar antidot device in which nanoparticles were introduced via droplets rather than a microfluidic channel, the largest shift was only 44 G with a sensitivity of 7.57 G/ng. This indicated that introduction of the nanoparticles via microfluidics results in stronger responses from the ferromagnetic resonances. The results for both devices demonstrated that ferromagnetic antidot nanostructures incorporated within planar microresonators can detect nanoparticles captured from dispersions. Using detection scheme (ii), without the antidot array, we observed a strong resonance within the nanoparticles. The resonance’s strength suggests that direct detection is more sensitive to magnetic nanoparticles than indirect detection using a nanostructure, in addition to being much simpler.
Keywords: nanoparticles; sensors; fluids; ferromagnetic resonance; magnetism; microfluidics
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Nanomaterials 14(2024), 19
Online First (2023) DOI: 10.3390/nano14010019
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38241
Graphene and Other 2D Materials: Basics and Light-Matter interaction
Abstract
We discuss basic physical properties of graphene and other 2D materials, in particular TMDCs and their heterostructures with a focus on light-matter interaction.
Keywords: graphene; 2D materials; light-matter interaction
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Lecture (others)
Summer school CRC 1242, 21.-25.08.2023, Selb, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38240
Auger scattering in Landau-quantized graphene and Hg0.83Cd0.17Te
Abstract
We explore the carrier dynamics in graphene and gapless bulk Hg0.83Cd0.17Te under Landau quantization. To this end, individual levels of the non-equidistant Landau ladders are pumped and probed by circularly polarized mid-infrared radiation pulses. While Auger scattering is very efficient in graphene, resulting in carrier redistribution on a ps timescale, this process is strongly suppressed in Hg0.83Cd0.17Te, yielding two orders of magnitude longer lifetimes.
Keywords: graphene; HgCdTe; Landau quantization
Involved research facilities
- Radiation Source ELBE DOI: 10.17815/jlsrf-2-58
- F-ELBE
Related publications
- DOI: 10.17815/jlsrf-2-58 is cited by this (Id 38239) publication
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Invited lecture (Conferences)
24th Conference on onApplied Electromagnetics and Communication (ICECOM 2023), 27.-29.09.2023, Dubrovnik, Kroatien
Permalink: https://www.hzdr.de/publications/Publ-38239
Low energy carrier dynamics in Landau quantized graphene and HgCdTe - Perspectives for optical gain?
Winnerl, S.; Seidl, A.; But, D.; Orlita, M.; Helm, M.
Abstract
Over six decades ago, the potential of relativistic electrons to emit electromagnetic radiation was initially reported [1]. The discovery of graphene with a band structure resembling massless Dirac fer-mions revitalized the search for Landau-level lasing schemes [2, 3] that started earlier on non-parabolic semiconductors. The realization of a maser based on this concept, with tuning through changes in magnetic field, holds significant appeal, especially for applications within the terahertz frequency range.
The initial steps towards reaching optical gain are selective pumping of individual Landau levels (LLs) and characterizing the lifetimes in these levels. The carrier dynamics in the three-level system LL-1, LL0 and LL1 of the non-equidistant Landau ladder in graphene was investigated by pump-probe ex-periments. Circularly polarized radiation was utilized to selectively pump and probe the energetically degenerate transitions LL-1 → LL0 and LL0 → LL1 [4]. The experiments were carried out at a photon energy of 75 meV (wavelength 16.5 µm) using the free-electron laser FELBE as a source for intense ps pulses [5]. Our findings indicate, fast Auger scattering rapidly redistributes the carriers [4]. Since several Landau laser schemes [2, 3] involve the levels LL1 and LL2, we performed pump-probe experiments on the transitions LL-1 → LL2 and LL-2 → LL1.
Pumping and probing with co-polarized radiation results in higher pump-probe signals as compared to counter-polarized configurations (cf. Fig. 1). Note that in the absence of scattering, the coun-ter-polarized configuration would provide no signal as it probes levels that are not directly affected by optical pumping. The results show that within the temporal resolution of the experiment, a non-equilibrium distribution is achieved. However, it rapidly thermalizes as indicated by the induced transmission in counter-polarized configurations that reaches a maximum a few ps later than the signals in co-polarized configuration. In summary, while the linear band structure is ideal for selective optical pumping, our experiments indicate that rapid Coulomb scattering severely limits potential to achieve population inversion in Landau-quantized graphene. For comparison, we have explored the dynamics in HgCdTe. Materials with a Cd concentration of 17 % feature (three dimensional) linear dispersion along with flat bands. The main difference to graphene is the strong spin-orbit coupling in this material. As a consequence, the energy Eigenvalues are modified to a non-equidistant ladder that does not comprise pairs of levels that match energetically for Auger scattering. Pump-probe experiments on the lowest levels reveal lifetimes of 0.5 ns, i.e. two orders of magnitude longer than in graphene, indicating that indeed Auger scattering is strongly suppressed. In this material, tunable classical cyclotron emission in the THz range has been realized upon electrical excitation.
References:
[1] J. Schneider, Phys. Rev. Lett. 2, 504 (1959).
[2] Y. R. Wang, M. Tokman, A. Belyanin, Phys. Rev. A 91, 033821 (2015).
[3] S. Brem, F. Wendler, S. Winnerl, E. Malic, Phys. Rev. Mater. 2, 034002 (2018)
[4] M. Mittendorff et al. Nature Phys. 11, 75 (2015).
[5] M. Helm et al., Eur. Phys. J. Plus 138, 158 (2023).
[6] D.B. But et al., Nat. Photonics 13, 783 (2019).
Keywords: Landau quantization; graphene; HgCdTe; Landau level gain
Involved research facilities
- Radiation Source ELBE DOI: 10.17815/jlsrf-2-58
- F-ELBE
Related publications
- DOI: 10.17815/jlsrf-2-58 is cited by this (Id 38238) publication
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Invited lecture (Conferences)
22nd International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON 22), 14.-18.08.2023, Münster, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38238
Terahertz radiation from a large-area photoconductive emitter via high average power Yb-oscillator
Khalili, M.; Vogel, T.; Mansourzadeh, S.; Winnerl, S.; Saraceno, C.
Abstract
Photoconductive emitters excited by fs-lasers are the most commonly used emitters in THz-TDS systems, enabling record high dynamic range and wide bandwidths [1,2]. So far, these emitters have mostly optimized for operation with low average power, low-cost fs-laser systems and have a typical dimension of a few µm^2 for the photoconductive gap [3]. In parallel, large-area emitters with mm^2 size have been explored for scaling fluence and obtaining high fields [4]. However, so far, no attempts have been made of using high average power laser systems as excitation sources, as a possible path to increase the THz source average power and reach even higher dynamic range than current reported records. In this work, we present our first results in this direction and show THz emission from a large area photoconductive emitter (LAE) based on SI-GaAs with a 1×1 cm^2 active area, excited by a frequency-doubled home-built high average power ultrafast oscillator, capable of 92 fs at a centre frequency 515 nm with 90 MHz repetition rate and 17 W of average power. We show here preliminary results exciting the LAE with 1 W from this laser system, which is to the best of our knowledge the highest average power applied to such an emitter, without any apparent sign of thermal saturation.
1. R. B. Kohlhaas, S. Breuer, L. Liebermeister, S. Nellen, M. Deumer, M. Schell, M. P. Semtsiv, W. T. Masselink, and B. Globisch, Appl. Phys. Lett. 117, 131105 (2020).
2. U. Nandi, K. Dutzi, A. Deninger, H. Lu, J. Norman, A. C. Gossard, N. Vieweg, and S. Preu, Opt. Lett. 45, 2812 (2020).
3. S. Winnerl, J Infrared Milli Terahz Waves 33, 431 (2012).
4. M. Beck, H. Schäfer, G. Klatt, J. Demsar, S. Winnerl, M. Helm, and T. Dekorsy, Opt. Express 18, 9251 (2010).
Keywords: terahertz; photoconductive emitter; large-area emitter
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Poster
CLEO Europe/EQEC, 26.-30.06.2023, München, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38237
Low-energy population inversion in graphene evidenced in a three-pulse pump-probe experiment
Mavridou, K.; Seidl, A.; Pashkin, O.; Helm, M.; Winnerl, S.
Abstract
Population inversion and optical gain are often difficult to measure in systems that do not exhibit lasing. For example, two-color pump-probe experiments targeting gain require precise reference measurements in order to distinguish gain from simple absorption bleaching due to Pauli blocking. In the mid-infrared (MIR) and far-infrared (FIR) spectral range such experiments are even more difficult as free-carrier absorption complicates the analysis. Here we utilize a three-pulse technique [1], which has been employed to find evidence for gain and spectral hole burning in the near-infrared (NIR), to study the dynamics of the MIR population inversion in optically pumped intrinsic graphene. Graphene is an interesting material to apply this technique since there are on one hand many reports on ultrafast thermalization, excluding inversion, but on the other hand many suggestions to realize gain, in particular in the THz range.
The principle of the technique is sketched in Fig. 1a. A strong NIR “gain” pulse (photon energy 1.55 eV) excites interband transitions in an epitaxial multilayer graphene sample on SiC. The majority of graphene layers is almost intrinsic. The low-energy carrier dynamics is monitored by measuring the differential transmission change in a degenerate MIR (photon energy 250 meV) pump-probe experiment. This differential transmission generally is positive, corresponding to bleaching via Pauli blocking by carriers that are photoexcited by the MIR pump pulse. If, however, the gain pulse is strong enough to induce an inverted population at 250 meV, the situation is qualitatively different: Now the mid-infrared pulse causes stimulated emission from the inverted population, thus decreasing the number of carriers in the conduction band at the probed energy. Consequently, the differential transmission with regard to the MIR pump pulse changes from positive to negative (cf. Fig.1b)
In addition to the NIR fluence dependence shown in Fig. 1b we also present for the gain dynamics varying the time delay between gain pulse and mid-infrared pump pulse. The observed transient gain is a consequence of a bottleneck of carrier relaxation via optical phonons and the decreasing density of states in the vicinity of the Dirac point. NIR transient gain has been observed previously in doped graphene [2], where a bottleneck appears above the Fermi level.
References
[1] K. Kim, J. Urayama, T. B. Norris, J. Singh, J. Phillips, and P. Bhattacharya, "Gain dynamics and ultrafast spectral hole burning in In(Ga)As self-organized quantum dots," Appl. Rev. Lett. 81, 670 (2002).
[1] T. Li, L. Luo, M. Hupalo, J. Zhang, M. C. Tringides, J. Schmalian, and J. Wang, "Femtosecond population inversion and stimulated emission of dense Dirac fermions in graphene," Phys. Rev. Lett. 108, 167401 (2012).
Keywords: gain; population inversion; ultrafast dynamics; graphene
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Poster
CLEO Europe/EQEC, 26.-30.06.2023, München, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38236
Solution-processable, flexible, and highly conductive polycaprolactone/molybdenum composites for fully biodegradable transient electronic sensors
Janićijević, Ž.; Huang, T.; Davydiuk, N.; Tonmoy, T. H.; Oliveros Mata, E. S.; Sandoval Bojorquez, D. I.; Besford, Q. A.; Makarov, D.; Baraban, L.
Abstract
The design and construction of transient electronic sensors face significant constraints, primarily due to the scarcity of degradable materials capable of meeting the criteria for safe degradation, adequate physicochemical properties, and compatibility with existing fabrication and processing methods. Materials-related challenges become particularly pronounced when direct contact between the electrically conductive component of the sensing element and the aqueous electrolyte medium is required for measurements,1 as is the case in the electrochemical determination of various (bio)chemical analytes. In such scenarios, conductive films based on biodegradable metals frequently dissolve in an insufficiently controlled manner,2 leading to compromised structural integrity and disruption of the measurement process. Here, we introduce highly conductive, flexible, and free-standing composite films comprised of polycaprolactone and molybdenum (PCL/Mo). These PCL/Mo films are well-suited for use in conductive lines, interconnects, and degradable electrodes within transient sensors. The films are fabricated using conventional solution processing techniques, commencing with a viscous ink formulation that includes PCL and fine Mo microparticles. The PCL/Mo films exhibit electrical conductivities of up to ~10 kS/m and maintain a flat impedance profile that resembles an ideal resistor at frequencies up to 100 kHz. Furthermore, they remain stable after undergoing hundreds of bending cycles. When tested in a simulated physiological medium in vitro, the PCL/Mo films degrade gradually due to Mo corrosion and PCL hydrolysis, while still retaining their electrical and mechanical properties for up to 2 months. The desired patterning of PCL/Mo films can be achieved through laser cutting or printing approaches. Additionally, patterned PCL/Mo films can be joined with flexible PCL films using biodegradable glue or thermal bonding to create fully biodegradable sensors. Therefore, PCL/Mo films are excellent candidates for the construction of impedance-based degradable sensors and reliable flexible interconnects in transient electronic devices, unlocking the opportunity to address challenging applications such as fully biodegradable electrochemical biosensors for point-of-care testing or implantable transient devices for healthcare monitoring. As a proof-of-concept application of PCL/Mo films, we demonstrate a fully biodegradable impedimetric sensor for the detection of amylase, relying on monitoring the degradation of thin glycogen (polysaccharide) coatings.
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Lecture (Conference)
9th International Winterschool on Bioelectronics, 16.-23.03.2024, Kirchberg in Tirol, Austria
Permalink: https://www.hzdr.de/publications/Publ-38235
All-silicon single photon sources based on deterministic defect engineering in photonic diodes
Schmitt, S. W.; Ritter, S.; Arslan, D.; Klingner, N.; Hlawacek, G.; Eilenberger, F.
Abstract
In this study, we propose the development of a purely silicon-based photonic enhanced single photon emitter that can be optically or electrically pumped. Its design is based on an introduction of near-infrared (NIR) single photon emitting color centers in silicon photonic resonators and diodes by focused ion beams and high energy ion implantation. Color centers will deterministically be implanted in positions of guided high-Q modes to ensure an efficient optical coupling and to enhance the single photon purity, photon indistinguishability and brightness of the device. Implanted species to be tested in the experiments are C and Si that create various NIR single photon emitting centers in silicon.
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38234) publication
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Lecture (Conference)
SPIE Nanoscience + Engineering, 23.08.2023, San Diego, USA
DOI: 10.1117/12.2677738
Permalink: https://www.hzdr.de/publications/Publ-38234
Nonlinear dynamics and time-resolved spectroscopy in graphene investigated at the free-electron laser FELBE
Abstract
The FELBE free-electron laser delivers intense THz and mid infrared pulses that are ideal to excite various low-energy quasipartcles in solids and to study their ultrafast dynamics [1]. We present the capabilities in the FELBE laboratories for degenerate and two-color pump-probe experiments, four-wave mixing and time-resolved near-field experiments. As an example, we show how nonlinear intraband transport in bilayer graphene manifests itself in polarization resolved pump-probe experiments [2]. Polarization resolved pump-probe experiments furthermore shed light into the microscopic scattering mechanisms, allowing us to disentangle Coulomb and phonon-related scattering processes [3].
[1] M. Helm, S. Winnerl, A. Pashkin, J. M. Klopf, J.-C. Deinert, S. Kovalev, P. Evtushenko, U. Lehnert, R. Xiang, A. Arnold, A. Wagner, S. M. Schmidt, U. Schramm, T. Cowan & P. Michel, Eur. Phys. J. Plus 138, 158 (2023).
[2] A. Seidl, R. Anvari, M. M. Dignam, P. Richter, T. Seyller, H. Schneider, M. Helm, and S. Winnerl Phys. Rev. B 105, 085404 (2022).
[3] J. C. König-Otto, M. Mittendorff, T. Winzer, F. Kadi, E. Malic, A. Knorr, C. Berger, W. A. de Heer, A. Pashkin, H. Schneider, M. Helm, and S. Winnerl, Phys. Rev. Lett. 117, 087401 (2016).
Keywords: FELBE; pump-probe spectroscopy; ultrafast dynamics
Involved research facilities
- Radiation Source ELBE DOI: 10.17815/jlsrf-2-58
- F-ELBE
Related publications
- DOI: 10.17815/jlsrf-2-58 is cited by this (Id 38232) publication
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Poster
Dynamical Control of Quantum Materials, 22.-26.05.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38232
Generation and detection of THz radiation with photoconductive devices
Abstract
We discuss the basics and modern developements regarding generation and detection of pulsed and cw THz radiation with photoconductive antennas.
Keywords: terahertz; photoconductive antenna
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Lecture (others)
Winter College on Optics: Terahertz Optics and Photonics, 06.-17.02.2023, Trieste, Italia
Permalink: https://www.hzdr.de/publications/Publ-38231
RBS HEDGEHOG – New 680 msr RBS Setup for fastest channeling experiments and ultra-high sensitivity measurements
Klingner, N.; Heller, R.; Bektas, U.; Hlawacek, G.
Abstract
RBS as one of the most widely used IBA methods requires a rather high beam fluence due to the small backscattering cross-section. Although the lack of measurement statistics can be compensated by a longer measurement time, this can only be applied to macroscopic beam spots and is not possible for sensitive samples or in a micro beam setup.
Larger detectors are an easy means to increase the covered solid angle, however this is limited in terms of kinematic broadening and decreasing energy resolution due to increasing detector capacitance [1]. Multi-detector setups overcome this limitation and are attracting increasing interest in various laboratories. Geometric constraints, mechanical robustness, the cost of multiple MCA systems, as well as the difficulty of simultaneously analyzing data from the individual detectors make this a difficult but worthwhile endeavor.
In this contribution, we report on our recently commissioned setup - namely, the "RBS hedgehog" located at the 3 MV tandem accelerator of the HZDR’ Ion Beam Center. The setup is equipped with 78 independent RBS detectors arranged in 5 concentric rings with backscattering angles from 165° to 105° covering a total solid angle of 680 msr - equivalent to 34% of the total backscatter angle. The 78 independent MCA systems can handle up to 8 Mega counts per second.
The presentation will start with an introduction to RBS technique, it’s advantages and disadvantages. It will be followed by a theoretical design study of the influence of different detector configurations on the kinematic broadening for different energies and ion species. We then introduction the used in-house designed and fabricated PIPS detectors and MCA systems and present initial experimental results for various projectiles and energies. Finally, we will illustrate its power at a future application of ion beam induced phase transformation in Ga2O3 [2].
[1] Klingner, N., et al. (2013), Optimizing the Rutherford Backscattering Spectrometry setup in a nuclear microprobe, NIMB, 306, 44-48. DOI: 10.1016/j.nimb.2012.12.062
[2] Azarov A., et al. (2023), Universal radiation tolerant semiconductor. Nat Commun. 2023 DOI: 10.1038/s41467-023-40588-0
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38230) publication
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Lecture (Conference)
WG1 FIT4NANO Meeting, 09.10.2023, Belval, Luxembourg
Permalink: https://www.hzdr.de/publications/Publ-38230
On demand spatially, controlled fabrication of single photon emitters in Silicon by liquid metal alloy ion source focused ion beam implantation
Klingner, N.; Hollenbach, M.; Bischoff, L.; Hlawacek, G.; Astakhov, G.
Abstract
Single photon emitters (SPE) are fundamental building blocks for future quantum technology applications. However, many approaches lack the required spatial placement accuracy and Si technology compatibility required for many of the envisioned applications. Here, we present a method to place single or few SPEs emitting in the telecom O-band1. The successful integration of these telecom quantum emitters into photonic structures such as micro-resonators, nanopillars and photonic crystals with sub-micrometer precision paves the way toward a monolithic, all-silicon-based semiconductor-superconductor quantum circuit for which this work lays the foundations.
To achieve our goal, we employ home built AuSi liquid metal alloy ion sources (LMAIS) and an Orsay Physics CANION M31Z+ focused ion beam (FIB). Silicon-on-insulator substrates from different fabrication methods have been irradiated with Si++ 40 keV ions in a spot pattern of 6 to 500 ions per spot.
For the analysis and confirmation of the fabrication of true SPEs a home build photo luminescence setup has been used. G-centers formed by the combination of two carbon atoms and a silicon atom with a zero phonon lines (ZPL) at 1278 nm have been created in carbon rich SOI wafers. In ultra clean SOI wafers W-centers, a tri-interstitial Si complex has been created with a ZPL at 1218 nm. The achieved lateral SPE placement accuracy is below 50 nm in both cases and the success rate of SPE formation is more than 50%.
Finally, we give an overview on possible other applications and give an outlook on future projects and instrumentation developments.
1Hollenbach, M., Klingner, N., Jagtap, N.S. et al. Wafer-scale nanofabrication of telecom single-photon emitters in silicon. Nature Communications 13, 7683 (2022). https://doi.org/10.1038/s41467-022-35051-5
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38229) publication
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Lecture (Conference)
ICMAT 2023, 26.06.2023, Singapore, Singapore -
Lecture (Conference)
3rd FIT4NANO Workshop, 19.07.2023, Lissabon, Portugal
Permalink: https://www.hzdr.de/publications/Publ-38229
TIBUSSII - the first triple beam single ion implantation setup for quantum applications
Klingner, N.; Hlawacek, G.; Facsko, S.; Wedel, G.; Grunze, S.; Kirschke, T.; Lange, B.; Findeisen, S.; Silvent, J.; Delobbe, A.
Abstract
The ongoing miniaturization has reached a point where dopants, impurities or active impurities reach the quantum limit, making deterministic single ion implantation (SII) indispensable. Moreover, applications in quantum computing, spintronics, and magnonics require at the same time, a very precise spatial placement of these implants. Other requirements for such an implantation system would be a wide range of available ion species, the ability to implant at extremely low fluence as well as low voltage operation.
Our new system, named Tibussii, is expected to address all of these requirements. It will be the first UHV system to include a liquid metal alloy ion source (LMAIS) focused ion beam (FIB) column, a plasma FIB, and a scanning electron microscope (SEM). The 4-nm SEM will be used for damage-free navigation, orientation and inspection. Both FIB columns are mass-separated columns with three Einzellenses, a chicane for neutral particles, and additional blankers and features optimized for single ion implantation.
We will show the current status of the system, which is currently being installed and further developed by HZDR and Orsay Physics. To verify the implantation of single ions, we are currently developing a secondary electron (SE) detection system with a sensitivity close to unity. It will be based on a semiconductor detector and is expected to surpass the detection efficiency of existing systems based on electron multiplication, such as channeltrons or microchannel plates.
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38228) publication
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Poster
6th EUFN Workshop 2023, 08.06.2023, Zürich, Schweiz -
Invited lecture (Conferences)
AVS 69, 09.11.2023, Portland, USA -
Lecture (others)
(Online presentation)
Sino-German Symposium Defect Engineering in SiC and Other Wide Bandgap Semiconductor, 23.10.2023, Shenzhen, China
Permalink: https://www.hzdr.de/publications/Publ-38228
Influence of crystal structure on helium-induced tendril formation in an FeCoCrNiV high-entropy alloy
Klingner, N.; Svenja, L.; Hlawacek, G.; Hübner, R.; Amy, S. G.; Russell, G.; Le, M.
Abstract
High-entropy alloys (HEAs) are a relatively new class of metal alloys composed of several principal elements, usually at (near) equiatomic ratios. Our goal is to understand how such a multicomponent alloy behaves under irradiation. The FeCoCrNiV HEA exhibits both a face-centred cubic (fcc) and a body-centred tetragonal (bct) phase, thus allowing us to specifically study the influence of crystalline structure at very similar chemical composition. We irradiated both phases with a focussed He beam provided by a helium ion microscope (HIM) at temperatures between room temperature and 500∘C. The irradiation fluence was varied between 6× 1017 ions/cm2 and 1× 1020 ions/cm2. High-resolution images of the irradiated areas were taken with the same HIM. Selected irradiated areas were additionally studied by TEM in combination with EDXS. Under irradiation, pores start to be generated in the material with pore sizes differing significantly between the two phases. At higher fluences and above a critical temperature, a tendril structure forms in both phases. We found that the critical temperature depends on the phase and is lower for fcc. TEM images reveal that the tendrils span the whole depth of the irradiated area, and are accompanied by bubbles of various sizes. Scanning TEM-based EDXS of these structures indicates a He-induced change in composition.
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38227) publication
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Lecture (Conference)
MML Workshop Jülich, 20.04.2023, Jülich, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38227
Fabrication of 2D magnets by ion implantation of phyllosilicates
Zubair Khan, M.; Klingner, N.; Hlawacek, G.; Matković, A.; Teichert, C.
Abstract
Since the first reports on intrinsically magnetic two-dimensional (2D) materials in 2017 [1,2], the price-to-pay for accessing their monolayers is still the lack of ambient stability. Recently, we demonstrated weak ferromagnetism in 2D Fe:talc at room temperature and proposed iron-rich phyllosilicates as a promising platform for air-stable magnetic monolayers [3]. Since these minerals are rather rare and since phyllosilicates are hard to synthesize, we suggest here as an alternative ion implantation to tailor the magnetic properties of the phyllosilicates. Nonmagnetic, single-crystalline bulk talc crystals [4] were implanted with 50 keV iron and cobalt ion beams at different substrate temperatures. In all cases, ultra-thin layers could be exfoliated indicating that the layered crystal structure is maintained after ion irradiation. For both ion species, the Mg-OH Raman peak showed a triplet formation implying a successful substitution of Mg by Fe or Co in the talc layers.
[1] Gong, C., et al., Nature 546, 265 (2017).
[2] Huang, B., et al., Nature 546, 270 (2017).
[3] A. Matković, et al., npj 2D Mat. Appl. 5, 94 (2021).
[4] B. Vasić, et al., Nanotechnology 32, 265701 (2021).
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38226) publication
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Lecture (Conference)
DPG Frühjahrstagung, 20.03.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38226
Spatially controlled fabrication of telecom single-photon emitters in Si by focused ion beam implantation
Klingner, N.; Hollenbach, M.; Jagtap, N.; Bischoff, L.; Fowley, C.; Kentsch, U.; Hlawacek, G.; Erbe, A.; Abrosimov, N. V.; Helm, M.; Berencen, Y.; Astakhov, G.
Abstract
Single photon emitters (SPE) are the starting point and foundation for future photonic quantum technologies. We present the laterally
controlled fabrication of single G and W centers in silicon that emit in the telecom O-band. We utilized home built gold-silicon liquid metal
alloy ion sources (LMAIS) in a focused ion beam (FIB) system to perform mask-free implantation of 40 keV Si ions from 6 to 500 ions per
spot. Analysis and confirmation of SPEs has been done in a home-build cryo-photoluminescence setup. We will demonstrate a success rate of
more than 50% and upscaling to wafer-scale. We will also provide an insight and overview on the LMAIS technology and an outlook on
other potential applications of FIB implantation.
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38225) publication
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Lecture (Conference)
DPG Frühjahrstagung, 20.03.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38225
Applying thallium isotopic compositions as novel and sensitive proxy for Tl(I)/Tl(III) transformation and source apportionment
Liu, J.; Wang, L.; Lin, J.; Yuan, W.; Li, L.; Peng, Y.-K.; Xiong, X.; Cao, H.; Wei, X.; Ouyang, Q.; Lippold, H.; Wang, J.; Lin, K.
Abstract
Thallium is a rare metal known for its highly toxic nature. Recent research has indicated that the precise determination of Tl isotopic compositions using Multi Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP MS) provides new opportunities for understanding Tl geochemical behavior. While isotopic fractionation of Tl derived from anthropogenic activities (e.g., mining, smelting) have been reported, there is limited information regarding Tl influenced by both natural weathering processes and anthropogenic origins. Herein, we investigated, for the first time, the Tl isotopic compositions in soils across a representative Tl-rich depth profile from the Lanmuchang (LMC) quicksilver mine (southwest China) in the low-temperature metallogenesis zone. The results showed significant variations in Tl isotope signatures (ε205Tl) among different soil layers, ranging from –0.23 to 3.79, with heavier isotope 205Tl enrichment observed in the bottom layers of the profile (ε205Tl = 2.18–3.79). This enrichment of 205Tl was not solely correlated with the degree of soil weathering but was also partially associated with oxidation of Tl(I) by Fe (hydr)oxide minerals. Quantitative calculations using ε205Tl vs. 1/Tl data further indicated that the Tl enrichment across the soil depth profile was predominantly derived from anthropogenic origins. All these findings highlight the robustness and reliability of Tl isotopes as a proxy for identifying both anthropogenic and geogenic sources, as well as tracing chemical alterations and redox-controlled mineralogical processes of Tl in soils. The nascent application of Tl isotopes herein not only offers valuable insights into the behavior of Tl in surface environments, but also establishes a framework for source apportionment in soils under similar circumstances.
Keywords: Soil profile; Thallium contamination; Isotope fractionation; Geochemical fractionation; Environmental pollution tracer
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Science of the Total Environment 913(2024), 169542
Online First (2023) DOI: 10.1016/j.scitotenv.2023.169542
Cited 9 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38224
Magnetically aware actuating composites: Sensing features as inspiration for the next step in advanced magnetic soft robotics
Oliveros Mata, E. S.; Xu, R.; Guo, L.; Makarov, D.
Abstract
In this perspective, we explore the convergence of sensing and actuation in magnetic composites and its potential applications in various fields. There is a need for multifunctional mechanically flexible materials that can be easily processed into functional devices that respond to a wide range of physical stimuli, including magnetic fields. These characteristics aim for lightweight and mechanically imperceptible systems that help us to interact with technology and with each other without the need for a bulky gadget. Typically, magnetically responsive devices are constructed using materials that do not necessarily possess flexible properties, so magnetosensitive composites with tailored magnetic, conductive, and flexible properties arising from the combination of their constituents have been proposed. Such property tunability is, in turn, beneficial for achieving functional convergence. This perspective aims to address several of the challenges associated with magnetoresponsive soft composites while highlighting the synergistic Q2 convergence that will take further the applications of magnetically aware actuating composites.
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Physical Review Applied 20(2023), 060501
DOI: 10.1103/PhysRevApplied.20.060501
Cited 3 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38223
Transport of dust across the Solar System: Constraints on the spatial origin of individual micrometeorites from cosmic-ray exposure
Feige, J.; Airo, A.; Berger, D.; Brückner, D.; Gärtner, A.; Genge, M.; Leya, I.; Habibi Marekani, F.; Hecht, L.; Klingner, N.; Lachner, J.; Li, X.; Merchel, S.; Nissen, J.; Patzer, A. B. C.; Peterson, S.; Schropp, A.; Sager, C.; Suttle, M. D.; Trappitsch, R.; Weinhold, J.
Abstract
The origin of micrometeorites (MMs) from asteroids and comets is well-established, but the relative contribution from these two classes remains poorly resolved. Likewise, determining the precise origin of individual micrometeorites is an open challenge. Here, cosmic-ray exposure ages are used to resolve the spatial origins of twelve MMs collected from urban areas and Antarctica. Their 26Al and 10Be concentration, produced during cosmic-ray irradiation in space, were measured by accelerator mass spectrometry. These data are compared to results from a model simulating the transport and irradiation of the MM precursors in space. This model, for the first time, considers a variety of orbits, precursor particle sizes, compositions, and densities and incorporates non-isotropic solar and galactic cosmic-ray flux profiles, depth-dependent production rates, as well as spherical evaporation during atmospheric entry. While the origin for six MMs remains ambiguous, two MMs show a preferential tendency towards an origin in the Inner Solar System (Near Earth Objects to the Asteroid Belt) and four towards an origin in the Outer Solar System (Jupiter Family Comets to the Kuiper Belt). These findings challenge the notion that dust originating from the Outer Solar System is unlikely to survive long-term transport and delivery to the terrestrial planets.
Keywords: micrometeorites; exposure age; 26Al; 10Be; AMS
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38222) publication
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Philosophical Transactions of the Royal Society A 382(2024)2273
DOI: 10.1098/rsta.2023.0197
Cited 3 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38222
Design and Development of Transient Sensing Devices for Healthcare Applications
Janićijević, Ž.; Huang, T.; Sandoval Bojorquez, D. I.; Tonmoy, T. H.; Pané, S.; Makarov, D.; Baraban, L.
Abstract
With the ever-growing requirements in the healthcare sector aimed at personalized diagnostics and treatment, continuous and real-time monitoring of relevant parameters is gaining significant traction. In many applications, health status monitoring should be carried out by dedicated wearable or implantable sensing devices only within a defined period and followed by sensor removal without additional risks for the patient. At the same time, disposal of the increasing number of conventional portable electronic devices with short life cycles raises serious environmental concerns due to the dangerous accumulation of electronic and chemical waste. An attractive solution to address these complex and contradictory demands is offered by biodegradable sensing devices. Such devices should be able to perform required tests within a programmed period and then disappear by safe resorption in the body or harmless degradation in the environment. This review critically assesses the design and development concepts related to biodegradable and bioresorbable sensors for healthcare applications. We comprehensively address different aspects, from fundamental material properties and sensing principles to application-tailored designs, fabrication techniques, and device implementations. We emphasize the emerging approaches spanning the last 5 years and provide a broad insight into the most important challenges and future perspectives of biodegradable sensors in healthcare.
Keywords: biodegradable electronics; biosensors; healthcare applications; biomedical devices; point-of-care diagnostics; clinical diagnostics; wearable electronics
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Advanced Science 11(2024)20, 2307232
DOI: 10.1002/advs.202307232
Cited 6 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38221
Advances in biomedical device engineering: From polymeric biomaterials for electrically controlled drug delivery systems to cost-effective electrochemical biosensors
Abstract
The engineering of biomedical devices necessitates comprehensive and multidisciplinary approaches to tackle specific problems in the biomedical field. These devices must also be designed to operate effectively in real-world applications, which demand scalability and cost-efficiency. The complexity of encountered challenges often sparks creative approaches, innovative designs, and sometimes unexpected collaborations, making the research journeys in the biomedical field truly exciting.
This seminar provides illustrative examples of how a seamless blending of knowledge and methodologies from electronics design, chemical engineering, biomaterials engineering, and biophysics can yield innovative devices or their components in two distinct yet complementary areas: controlled drug delivery and in vitro diagnostics. In the first part of the seminar, we delve into the development of polymeric biomaterials serving as compact reservoirs for active and passive controlled drug delivery, driven by non-specific electrical interactions. In the second part, we explore the development of cost-effective potentiometric field-effect transistor-based biosensing platforms and impedimetric biosensors tailored for advanced point-of-care applications. To conclude, the seminar provides a concise overview of the ongoing research endeavors within the Department of Nano-Microsystems for Life Sciences at the Institute of Radiopharmaceutical Cancer Research at Helmholtz-Zentrum Dresden-Rossendorf in Germany. This overview aims to highlight critical research challenges and interesting opportunities for future collaborations.
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Invited lecture (Conferences)
Seminar at the Department of Physics and Astronomy "Augusto Righi“, University of Bologna, 28.11.2023, Bologna, Italy
Permalink: https://www.hzdr.de/publications/Publ-38220
Deep underground measurement of ¹¹B(α,n)¹⁴N
Borgwardt, T. C.; Deboer, R. J.; Boeltzig, A.; Couder, M.; Görres, J.; Gula, A.; Hanhardt, M.; Manukyan, K. V.; Kadlecek, T.; Robertson, D.; Strieder, F.; Wiescher, M.
Abstract
The primordial elemental abundance composition of the first stars leads to questions about their modes of energy production and nucleosynthesis. The formation of 12C has been thought to occur primarily through the 3α process, however, alternative reaction chains may contribute significantly, such as 7Li(α,γ)11B(α,n)14N. This reaction sequence cannot only bypass the mass A=8 stability gap, but could also be a source of neutrons in the first star environment. However, the efficiency of this reaction chain depends on the possible enhancement of its low energy cross section by α-cluster resonances near the reaction threshold. A new study of the reaction 11B(α,n) 14N has been undertaken at the CASPAR underground facility at beam energies from 300–700keV. A 4π neutron detector in combination with pulse shape discrimination at low background conditions resulted in the ability to probe energies lower than previously measured. Resonance strengths were determined for both the resonance at a laboratory energy of 411keV, which was measured for the second time, and for a new resonance at 337keV that has been measured for the first time. This resonance, found to be significantly weaker than previous estimates, dominates the reaction rate at lower temperatures (T<0.2KG) and reduces the reaction rate in first star environments.
Keywords: Nuclear Astrophysics; Sanford Underground Laboratory; CASPAR; Neutron Detection
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Physical Review C 108(2023), 035809
DOI: 10.1103/PhysRevC.108.035809
Cited 2 times in Scopus
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Permalink: https://www.hzdr.de/publications/Publ-38219
CLYC as a neutron detector in low background conditions
Plaza, J.; Bécares, V.; Cano-Ott, D.; Gómez, C.; Martínez, T.; Mendoza, E.; Pérez De Rada, A.; Pesudo, V.; Sáez-Vergara, J. C.; Santorelli, R.; Villamarín, D.; Ianni, A.; Peña, C.; Balibrea-Correa, J.; Boeltzig, A.; Imbriani, G.
Abstract
We report on the thermal neutron flux measurements carried out at the Laboratorio Subterráneo de Canfranc (LSC) with two commercial 2"x2" CLYC detectors. The measurements were performed as part of an experimental campaign at LSC with He detectors, for establishing the sensitivity limits and use of CLYCs in low background conditions. A careful characterization of the intrinsic α and γ-ray background in the detectors was required and done with dedicated measurements. It was found that the activities in the two CLYC crystals differ by a factor of three, and the use of Monte Carlo simulations and a Bayesian unfolding method allowed us to determine the specific activities from the 238U and 232Th decay chains. The simulations and unfolding also revealed that the γ-ray background registered in the detectors is dominated by the intrinsic activity of the components of the detector such as the aluminum housing and photo-multiplier and that the activity within the crystal is low in comparison. The data from the neutron flux measurements with the two detectors were analyzed with different methodologies: one based on an innovative α/neutron pulse shape discrimination method and one based on the subtraction of the intrinsic α background that masks the neutron signals in the region of interest. The neutron sensitivity of the CLYCs was calculated by Monte Carlo simulations with MCNP6 and GEANT4. The resulting thermal neutron fluxes are in good agreement with complementary flux measurement performed with 3He detectors, but close to the detection limit imposed by the intrinsic α activity.
Keywords: Neutron Detection; Scintillator; CLYC; Underground Laboratory; Backgrounds
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European Physical Journal C 83(2023), 1049
DOI: 10.1140/epjc/s10052-023-12221-3
Permalink: https://www.hzdr.de/publications/Publ-38218
Innovative UniCAR/RevCAR-engineered T-cell therapy
Abstract
Innovative UniCAR/RevCAR-engineered T-cell therapy
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Invited lecture (Conferences)
B-specific Kick Off Meeting, 23.10.2023, Leiden, Niederlande
Permalink: https://www.hzdr.de/publications/Publ-38217
TheraSTAR – Project Overview
Feldmann, A.; Schmitz, M.; Bachmann, M.
Abstract
TheraSTAR – Project Overview
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Lecture (Conference)
SaxoCell Konsortium und SAB Meeting, 11.-12.09.2023, Leipzig, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38216
Robust Reconstruction of the Void Fraction from Noisy Magnetic Flux Density Using Invertible Neural Networks
Kumar, N.; Krause, L.; Wondrak, T.; Eckert, S.; Eckert, K.; Gumhold, S.
Abstract
Electrolysis stands as a pivotal method for environmentally sustainable hydrogen production. However, the formation of gas bubbles during the electrolysis process poses significant challenges by impeding reactions, diminishing cell efficiency, and dramatically increasing energy consumption. Furthermore, the inherent difficulty in detecting these bubbles arises from the non-transparency of the wall of electrolysis cells. Fortunately, these gas bubbles induce alterations in the cell’s conductivity, leading to corresponding fluctuations in the surrounding magnetic flux density. In this context, we can leverage external magnetic sensors to measure the magnetic flux density fluctuations induced by gas bubbles. Next, by solving the inverse problem of the Biot-Savart Law, we can estimate the conductivity, bubble size, and location within the cell. Nevertheless, reconstructing a high-resolution conductivity map from limited induced magnetic flux density measurements poses a formidable challenge as an ill-posed inverse problem. To overcome this challenge, we employ Invertible Neural Networks (INNs) to reconstruct the conductivity field. The inherent property of INNs, characterized by a bijective mapping between the input and output space, makes them exceptionally well-suited for resolving ill-posed inverse problems. We conducted extensive qualitative and quantitative evaluations to compare the performance of INNs with traditional approaches such as Tikhonov regularization. Our experiments demonstrate that, particularly in the presence of noise in the magnetic sensor data, our INN-based approach outperforms Tikhonov regularization in accurately reconstructing bubble distributions and conductivity fields. We hope that, given the efficacy of INNs shown in this work, they will become an indispensable deep-learning based approach for addressing inverse problems not only in Process Tomography but across various other domains.
Keywords: Machine Learning; Invertible Neural Networks; Normalizing Flows; Water Electrolysis; Biot-Savart Law; Inverse Problems; Current Tomography; Random Error Diffusion
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Sensors 24(2024)4, 1213
DOI: 10.3390/s24041213
Permalink: https://www.hzdr.de/publications/Publ-38215
Data publication: Learning from nature: recovery of rare earth elements by the extremophilic bacterium Methylacidiphilum fumariolicum
Singer, H.; Steudtner, R.; Sottorff, I.; Drobot, B.; Pol, A.; Op Den Camp, H. J. M.; Daumann, L. J.
Abstract
Rohdaten aus denen Ergebnisse und Grafiken erstellt wurden um die benötigten Erkenntnisse für diese Publikation zu generieren
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- DOI: 10.1039/d3cc01341c references this (Id 38214) publication
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Learning from nature: recovery of rare earth elements by the extremophilic …
ROBIS: 37960 has used this (Id 38214) publication of HZDR-primary research data
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Reseach data in the HZDR data repository RODARE
Publication date: 2024-01-05 Open access
DOI: 10.14278/rodare.2631
Versions: 10.14278/rodare.2632
License: CC-BY-4.0
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Permalink: https://www.hzdr.de/publications/Publ-38214
Development of UniCAR TM for targeting of FAP positive cells
Feldmann, A.; Rodrigues Loureiro, L. R.; Robinson, A.
Abstract
Development of UniCAR TM for targeting of FAP positive cells
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Lecture (Conference)
Monash-Helmholtz Laboratory for Radio-Immuno-Theranostics (MHELTHERA) Research Symposium, 16.-17.03.2023, Melbourne, Australia
Permalink: https://www.hzdr.de/publications/Publ-38213
Wie Dresdner Forschende Immunzellen gegen Krebs nutzen.
Abstract
Wie Dresdner Forschende Immunzellen gegen Krebs nutzen.
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Invited lecture (Conferences)
SaxoCell lecture, 10.02.2023, CRTD, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38212
Retention of trivalent actinides (Am, Cm) and lanthanides (Eu) by Ca feldspars
Lessing, J.; Neumann, J.; Bok, F.; Lützenkirchen, J.; Brendler, V.; Schmidt, M.; Stumpf, T.
Abstract
Abstract. The transport of radionuclides in the environment is a major problem for the safety assessment of radioactive waste repositories. Storage in deep geological repositories is considered a safe disposal strategy because of their ability to isolate hazardous components from the biosphere for hundreds of thousands of years. Minor actinides (i.e. Am, Cm and Np) dominate the radiotoxicity of spent nuclear fuel over geological time scales. In underground repositories, reducing conditions are expected and therefore the trivalent oxidation state is dominant for Am and Cm, as well as possibly for Pu. For investigations of the mobility of the trivalent actinides Am3+ and Cm3+, the less toxic trivalent rare earth elements, in particular Eu3+, are commonly used.
Besides clay and salt, crystalline rock is considered as a possible host rock for deep geological repositories. Crystalline rock (e.g. granite), consists mainly of quartz, mica, and feldspar. The latter are common alumino silicates making up ~60 Vol-% of the earth’s crust, but their sorption behaviour is not well understood, especially for the Ca-bearing members of the group.
Here, we study the sorption of trivalent actinides and their rare earth element homologues on plagioclase, Ca-bearing feldspars, quantitatively and mechanistically. Zeta potential of various Ca-feldspars show an unexpected increase at pH 4-7, which becomes more pronounced as the amount of Ca in the crystal lattice increases. This can be interpreted by assuming uptake of Al3+ and/or the precipitation of an Al phase, where Al originates from feldspar dissolution at different pH values.
Nevertheless, only minor differences were found in the retention and surface speciation of Cm3+ on Ca and K-feldspar (Neumann et al., 2021). Ca-feldspar has a slightly higher potential to retain trivalent metal ions compared to K feldspar. An inner sphere (IS) complex and its two hydrolysis forms have been identified on both minerals, but the hydrolysis of the IS complex is stronger in the Ca-rich mineral.
A surface complexation model for Ca-feldspar was developed by combining the batch sorption data and the spectroscopically identified surface complexes to describe the experimental data. These data will be the basis for the improvement of transport simulations for a reliable safety assessment of potential radioactive waste repositories in crystalline rock.
References
Neumann, J. et al.: Sorption of trivalent actinides (Cm, Am) and their rare earth analogues (Lu, Y, Eu, Nd, La) onto orthoclase: Batch experiments, Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) and Surface Complexation Modeling (SCM), J. Colloid Interface Sci. 591, 490-499, https://doi.org/10.1016/j.jcis.2020.11.041, 2021.
Keywords: Ca-Feldspar; Anorthite; Sorption; Trivalent Actinides; Lanthanides
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Poster
safeND 2023: Forschungssymposium des BASE, 13.-15.09.2023, Berlin, Germany
Permalink: https://www.hzdr.de/publications/Publ-38211
Influence of the Competition of Al on the Retention of Trivalent Actinides and their Homologues in Feldspar
Lessing, J.; Neumann, J.; Bok, F.; Lützenkirchen, J.; Brendler, V.; Schmidt, M.; Stumpf, T.
Abstract
Crystalline rock is one possible host rock for the final disposal of nuclear waste in a deep geological formation. For a proper safety assessment, it is of utmost importance to understand retention mechanisms of radionuclides at the water-mineral interface. The retention of trivalent actinides by K-feldspars, a main component of crystalline rock, was recently investigated by our group [1]. However, no sorption data of minor actinides is available for the series of Ca-feldspars (plagioclases) with different Al:Si ratios in the crystal lattice, which most likely causes differences in surface charge, dissolution, and sorption behavior.
Here, we study the sorption of trivalent actinides and their rare earth element homologues on Ca-feldspars quantitatively and mechanistically. We find that plagioclases show a stronger sorption affinity to actinides than K-feldspars (alkali feldspars). A possible explanation might be an increased concentration of Al³⁺ in the aqueous phase due to enhanced dissolution of the Ca-feldspars. The dissolved Al3+ may affect surface charge and sorption processes onto mineral surfaces, and in such case the underlying molecular mechanisms are expected to be complex and are clearly not well understood.
Therefore, we study the impact of Al3+ on the surface charge of K-feldspar and the concomitant effects on the retention of trivalent actinides and lanthanides. Zeta potential investigations reveal a strong impact of Al3+ on the surface charge of K-feldspar. The zeta potential increases for pH 4.5–7.5, and this increase is enhanced by higher added Al3+ concentration. Results from batch sorption experiments of Eu onto K-feldspar show a steeper sorption edge upon addition of Al3+, which can be interpreted as a slightly stronger sorption affinity. Indeed, in the presence of Al3+, K-feldspar behaves much like Ca-feldspar. To gain information about the formed surface complexes time resolved laser-induced fluorescence spectroscopy is applied. Potentially formed secondary phases of Al are evaluated by a combination of microscopy (SEM, TEM, Raman, AFM) and diffractometry (CTR/RAXR, high resolution PXRD). Ultimately, this will provide a better understanding of the fundamental mechanisms of sorption process of the minor actinides on naturally occurring mineral phases.
References
[1] Neumann, J. et al. (2021) J. Colloid Interface Sci. 591, 490-499.
Keywords: Feldspar; Actinide; Sorption; Charge Revearsal
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Lecture (Conference)
Goldschmidt Conference2023, 09.-14.07.2023, Lyon, France -
Poster
18th International Conference on the Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere (Migration Conference), 24.-29.09.2023, Nantes, France
Permalink: https://www.hzdr.de/publications/Publ-38210
Vorhersage der Abszessbildung bei Patienten mit chirurgisch bestätigter infektiöser Endokarditis anhand FDG-PET/CT-basierter Biomarke
Grosse, J.; Sag, S.; Menhart, K.; Hitzenbichler, F.; Schmid, C.; Hofheinz, F.; van den Hoff, J.; Maier, L.; Sag, C.; Hellwig, D.
Abstract
Ziel/Aim Die Leitlinien der Europäischen Gesellschaft für Kardiologie (ESC) aus dem Jahr 2015 definieren eine pathologische F-18-FDG-Anreicherung in der PET/CT als Hauptkriterium der modifizierten Duke-Kriterien zur Diagnose einer infektiösen Endokarditis (IE) bei Klappenprothesen. Ziel der Studie ist die Untersuchung der Bedeutung quantitativer F-18-FDG-PET/CT-Parameter in unserer realen Kohorte von Patienten mit chirurgisch bestätigter IE.
Methodik/Methods Die retrospektive Analyse umfasst alle Patienten (n=27), die in unserem Universitätsklinikum von 01/2014 bis 10/2018 mit chirurgisch bestätigter IE hospitalisiert waren und präoperativ eine F-18-FDG-PET/CT erhalten hatten. In der F-18-FDG-PET/CT wurden die bildbasierten Biomarker Maximum Standard Uptake Ratio (SURmax), metabolisch aktives Volumen (MTV) und Total Lesion Glycolysis (TLG) gemessen.
Ergebnisse/Results Bei der Dichotomisierung in Patienten mit (n=10) und ohne chirurgisch bestätigte Abszessbildung (n=17) stellten wir fest, dass bei Patienten mit chirurgisch gesicherter Abszessbildung MTV (etwa 5-fach) und TLG (etwa 7-fach) signifikant erhöht waren. Receiver-Operation-Characteristics (ROC)-Analysen zeigten, dass in unserer Studienkohorte TLG (berechnet als MTV x SURmean, d. h. TLG(SUR)) die größte Fläche unter der ROC-Kurve für die Vorhersage einer IE-bedingten Abszessbildung aufwies (0,841, 95%-Konfidenzintervall: 0,659-1) bei einer Sensitivität von 80% und Spezifität von 88% für TLG(SUR)>14,14 ml.
Schlussfolgerungen/Conclusions Die F-18-FDG-PET/CT-basierte quantitative Bewertung der TLG(SUR) könnte ein neuer Parameter für die Vorhersage der Endokarditis-assoziierten Abszessbildung und somit für die Planung der herzchirurgischen Klappensanierung von besonderer Relevanz sein.
Involved research facilities
- PET-Center
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Lecture (Conference)
Jahrestagung der Deutschen Gesellschaft für Nuklearmedizin, 19.-22.04.2023, Leipzig, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38209
Validation of the prognostic value of tumor asphericity and an extracellular matrix-related prognostic gene signature in non-small cell lung cancer patients
Hofheinz, F.; Klinger, B.; Amthauer, H.; Apostolova, I.; Blüthgen, N.; Cegla, P.; Cholewinski, W.; Kreißl, M.; Zips, D.; van den Hoff, J.; Zschaeck, S.
Abstract
Ziel/Aim The aim of the study was an independent evaluation of the prognostic value of a gene expression signature (EPPI) and the PET-derived tumor asphericity (ASP) in non-small cell lung cancer (NSCLC) patients.
Methodik/Methods This was a retrospective evaluation of PET imaging and gene expression data from three public databases and two institutional datasets. Altogether 253 NSCLC patients were included, all treated with curative intent surgery. Clinical parameters, standard PET parameters and ASP were evaluated in all patients. Additional gene expression data was available for 120 patients. Univariate and multivariate Cox regression and Kaplan-Meier analysis were calculated for the primary endpoint progression-free survival (PFS) and additional endpoints.
Ergebnisse/Results In the whole cohort a significant association with PFS was observed for ASP (p<0.001) and EPPI (p=0.012). On multivariate testing, EPPI remained significantly associated with PFS (p=0.018) in the subgroup of patients with additional gene expression data, while ASP was significantly associated with PFS in the whole cohort (p=0.012). In stage II patients, ASP was significantly associated with PFS (p=0.009) and a previously published cutoff value for ASP (19.5%) was successfully validated (p=0.008). In patients with additional gene expression data, EPPI showed a significant association with PFS, too (p=0.033). Exploratory combination of ASP and EPPI showed that the combinatory approach has potential to further improve patient stratification compared to the use of only one parameter.
Schlussfolgerungen/Conclusions The combination of EPPI and ASP seems to be a very promising approach for improvement of risk stratification in a group of patients with urgent need for a more personalized treatment approach.
Involved research facilities
- PET-Center
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Poster
Jahrestagung der Deutschen Gesellschaft für Nuklearmedizin, 19.-22.04.2023, Leipzig, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38208
Recovery of gallium (and indium) from spent LEDs: strong acids leaching versus selective leaching by siderophore desferrioxamine E
Zheng, K.; Benedetti, M. F.; Jain, R.; Pollmann, K.; van Hullebusch, E.
Abstract
This study aimed to carry out the adapted pre-treatment and subsequent characterization of spent surface mounted device (SMD) light emitting diodes (LEDs) as well as strong acids leaching and selective leaching of gallium (Ga) and indium (In) using desferrioxamine E (DFOE). The results show that the pre-treated spent SMD LED powder fraction (< 500 μm) contained the highest concentration of Ga and In, 290.4 ± 21.2 mg/kg and 64.9 ± 20.2 mg/kg, respectively. The use of strong acid 3 M HCl and 30% H2O2 was found to the highly effective in achieving a high leaching yield for Ga and In, 97 ± 6 % and 98 ± 4 %, respectively. However, the associated leaching of highly concentrated non-targeted elements (i.e. Cu, Pb, Al, and Fe) was found to be significantly higher than the targeted metals (Ga and In). Therefore, selective leaching could offer a promising approach to recover targeted metals from waste streams. It is the first attempt to test DFOE for the selective leaching of Ga and In from spent LEDs by adjusting the pH, solid/liquid (S/L) ratio, molar concentration ratio of DFOE and Ga (n = n(DFOE)/n(Ga)), and temperature to investigate the behavior of metal-DFOE complexation. The highest Ga leaching efficiency (12%) was found to be at pH 4, with a S/L ratio of 5 g/L and n = 20 at 40 °C. However, the competing elements (Al and Fe), can have a significant effect on the efficiency of the Ga leaching process. Concerning In recovery, selective leaching could achieve maximum In recovery yield (24%) within 24 hours at pH 7.3. This study provides deep knowledge to better understand the development of sustainable processes for the selective recovery of critical metals from spent SMD LEDs by DFOE.
Keywords: Characterization; pre-treatment; acids leaching; selective leaching; operational conditions; competition
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Separation and Purification Technology 338(2024), 126566
DOI: 10.1016/j.seppur.2024.126566
Cited 12 times in Scopus
Downloads
- Secondary publication expected
Permalink: https://www.hzdr.de/publications/Publ-38207
Blood-brain barrier permeability measured with arterial spin labeling as potential cerebrovascular biomarker over the lifespan
Padrela, B. E.; Tee, M.; Markus, S. H.; Geier, O.; Mahroo, A.; Grydeland, H.; Fladby, T.; Eickel, K.; Günther, M.; Barkhof, F.; Hilal, S.; Mutsaerts, H.-J.; Petr, J.
Abstract
Blood-brain barrier (BBB) dysfunction is considered a hallmark of Alzheimer’s disease
(AD), making non-invasive imaging of BBB with arterial spin labeling (ASL) MRI a potential imaging
biomarker (BBB-ASL). However, the normal BBB development over the lifespan is unknown. Here, we
created population-based BBB-ASL permeability reference maps, and aimed to investigate associations
between BBB-ASL, chronological age, and biological cerebrovascular age – expressed as white matter
hyperintensities (WMH) volume
Involved research facilities
- PET-Center
-
Contribution to proceedings
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, The Netherlands -
Poster
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, The Netherlands -
Contribution to proceedings
OHBM '23: Proceedings of the Organization for Human Brain Mapping Annual Meeting, 22.07.2023, Montreal, Canada -
Poster
OHBM '23: Proceedings of the Organization for Human Brain Mapping Annual Meeting, 22.07.2023, Montreal, Canada
Permalink: https://www.hzdr.de/publications/Publ-38206
Intrinsic magnetic properties of the layered antiferromagnet CrSBr
Long, F.; Mosina, K.; Hübner, R.; Sofer, Z.; Klein, J.; Prucnal, S.; Helm, M.; Dirnberger, F.; Zhou, S.
Abstract
van der Waals magnetic materials are an ideal platform to study low-dimensional magnetism. Opposed to other members of this family, the magnetic semiconductor CrSBr is highly resistant to degradation in air, which, in addition to its exceptional optical, electronic, and magnetic properties, is the reason the compound is receiving considerable attention at the moment. For many years, its magnetic phase diagram seemed to be well-understood. Recently, however, several groups observed a magnetic transition in magnetometry measurements at temperatures of around 40 K that is not expected from theoretical considerations, causing a debate about the intrinsic magnetic properties of the material. In this Letter, we report the absence of this particular transition in magnetization measurements conducted on high-quality CrSBr crystals, attesting to the extrinsic nature of the low-temperature magnetic phase observed in other works. Our magnetometry results obtained from large bulk crystals are in very good agreement with the magnetic phase diagram of CrSBr previously predicted by the mean-field theory; A-type antiferromagnetic order is the only phase observed below the Néel temperature at TN = 131 K. Moreover, numerical fits based on the Curie–Weiss law confirm that strong ferromagnetic correlations are present within individual layers even at temperatures much larger than TN.
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38205) publication
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Applied Physics Letters 122(2023), 222401
DOI: 10.1063/5.0175185
Cited 7 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38205
Associations Between Cardiovascular Risk Factors and Arterial Spin Labelling Derived Perfusion Parameters
Tee, M.; Padrela, B. E.; Konstandin, S.; Eickel, K.; Günther, M.; Petr, J.; Mutsaerts, H.-J.; Hilal, S.
Abstract
Decreased cerebral blood flow (CBF) and deterioration of blood-brain barrier (BBB) are suggested to be
precursor conditions of cognitive impairment. Using a novel multi-echo-time arterial spin labelling (ASL)
protocol, we examined the time of exchange (Tex) of water across the BBB as a measurement of BBB
permeability. We further examined the association of cardiovascular risk factors with Tex in an ongoing cohort
study.
Involved research facilities
- PET-Center
-
Poster
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, The Netherlands -
Contribution to proceedings
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, The Netherlands
Alzheimer's & Dementia
Downloads
Permalink: https://www.hzdr.de/publications/Publ-38204
An unsupervised deep learning framework for respiratory motion correction in PET
Rosin, B.; Nikulin, P.; Hofheinz, F.; Maus, J.; Braune, A.; Kotzerke, J.; van den Hoff, J.
Abstract
Breathing related patient motion is a serious source of image blurring in oncological whole body PET. Respiratory gating allows to subdivide the aquisition data into temporal bins ("gates") depending on the breathing cycle which are basically motion-free but exhhibit increased noise levels. Image registration of all gates to a reference gate and subsequent averaging is possible but traditional registration algorithms are frequently slow or of limited accuracy.
Deep learning methods have recently attracted much interest and have been successfully applied to image registration tasks. Their flexibility and execution speed are especially attractive in the present context. We have therefore implemented and evaluated an unsupervised deep learning framework for the registration of gated PET images.
Image volume pairs consisting of a fixed gate and a second moving gate serve as input to a convolutional neural network
which predicts a deformation vector field (DVF) mapping the moving image to the fixed image. The network is trained unsupervised by optimizing a similarity
metric between the registered image pairs as well as an additional regularization loss.
Fifty-two gated PET/CT scans (8 gates) were available for training (N=42; 2352 gate pairs) and testing (N=10).
Normalized cross correlation (NCC) was used as a measure of registration accuracy.
The motion corrected images were compared to the respective ungated image, single reference gate
and a commercially available motion correction method ("OncoFreeze", Siemens). Lesion SUVmax and noise levels in the liver were determined.
Our method achieved visually very satisfactory motion compensation and consequently improved NCC for all test scans. Motion artifacts were substantially reduced while maintaining the noise level of the ungated images. The detailed numerical results will be reported.
The proposed framework is suitable for efficient reduction of motion artifacts in PET and is competitive to the OncoFreeze method.
Keywords: motion correction; CNN; unsupervised; registration; PET; gates
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Lecture (Conference)
61. Jahrestagung der Deutschen Gesellschaft für Nuklearmedizin, 19.-22.04.2023, Leipzig, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38203
Associations between ASL-derived cerebrovascular health and cognitive performance: results from the Insight 46 study
Dijsselhof, M. B.; Lu, K.; Lorenzini, L.; Collij, L. E.; James, S.-N.; Thomas, D. L.; Scott, C. J.; Manning, E. N.; Cash, D. M.; Hughes, A. D.; Richard, M.; Barkhof, F.; Schott, J. M.; Petr, J.; Mutsaerts, H. J. M. M.
Abstract
Cardiovascular and cerebrovascular pathology may accelerate brain aging and cognitive
decline. Structural cerebrovascular imaging biomarkers, such as white matter
hyperintensities, reflect mostly irreversible accumulated damage. In contrast, cerebral blood
flow (CBF), measured with arterial spin labelling (ASL) perfusion MRI, is a potential early
haemodynamic biomarker of cognitive impairment. However, our understanding of
physiological CBF variability and its relation with cognition is limited.
Involved research facilities
- PET-Center
-
Poster
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, The Netherlands -
Contribution to proceedings
Alzheimer's Association International Conference, 15.07.2023, Amsterdam, Alzheimer's & Dementia
Alzheimer's & Dementia
DOI: 10.1002/alz.081945
Permalink: https://www.hzdr.de/publications/Publ-38202
Ten years of VASARI features: A systematic review and meta-analysis of its impact and performance in glioma imaging
Azizova, A.; Prysiazhniuk, Y.; Wamelink, I. J. H. G.; Petr, J.; Barkhof, F.; Keil, V. C.
Abstract
VASARI feature are a controlled vocabulary aiming to create reproducible terminology for glioma interpretation
Involved research facilities
- PET-Center
-
Lecture (Conference)
46th ESNR Annual meeting, 23.09.2023, Vienna, Austria
Permalink: https://www.hzdr.de/publications/Publ-38201
Recycling von Seltenen Erden
Abstract
Welche Materielien können heute schon gut recycelt werden und wie sieht das für die Seltenen Erden aus. Beim Parlamentarischen Abend Sustainability der mathematisch-naturwissenschaftlichen Gesellschaften stehen Wissenschaftler den Abgeordneten des Bundestages Rede und Antwort.
-
Invited lecture (Conferences)
SUSTAINABILITY - Parlmentarischer Abend der mathematisch-naturwissenschaftlichen Gesellschaften, 14.11.2023, Berlin, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38200
Potentiale von Biomolekülen zur Trennung von Mikroschadstoffen und zur Rückgewinnung von Metallen aus Industriewasser
Abstract
Vorstellung von Arbeiten die am Helmholtz Institut Freiberg für Ressourcentechnologie rund um das Thema Wasserausbereitung laufen.
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Invited lecture (Conferences)
Wissenstag "Sauberes Wasser", 3.11.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38199
[¹⁸F]Fluspidine – a PET tracer for imaging of σ1 receptors in the central nervous system
Ludwig, F.-A.; Laurini, E.; Schmidt, J.; Pricl, S.; Deuther-Conrad, W.; Wünsch, B.
Abstract
σ1 Receptors play a crucial role in various neurological and neurodegenerative diseases including pain, psychosis, Alzheimer’s disease, and depression. Spirocyclic piperidines represent a promising class of potent σ1 receptor ligands. The relationship between structural modifications and σ1 receptor affinity and selectivity over σ2 receptors led to the 2-fluoroethyl derivative fluspidine (2, Ki = 0.59 nM). Enantiomerically pure (S)-configured fluspidine ((S)-2) was prepared by enantioselective reduction of the α,β-unsaturated ester 23 with NaBH4 and the enantiomerically pure Co-catalyst (S,S)-24. The pharmacokinetic properties of both fluspidine enantiomers (R)-2 and (S)-2 were an-alyzed in vitro. Molecular dynamics simulations revealed very similar interactions of both fluspidine enantiomers with the σ1 receptor protein with a strong ionic interaction between the protonated amino moiety of the piperidine ring and the COO- moiety of glutamate 172. The ¹⁸F-labeled radiotracers (S)-[¹⁸F]2 and (R)-[¹⁸F]2 were synthesized in automated syntheses using a TRACERlab FX FN synthesis module. High radiochemical yields and radiochemical purity were achieved. Radiometabolites were not found in the brains of mice, piglets, and rhesus monkeys. While both enantiomers revealed similar initial brain uptake, the slow washout of (R)-[¹⁸F]2 indicated a kind of irreversible binding. In a first clinical trial, (S)-[¹⁸F]2 was used to visualize σ1 receptors in the brain of patients with major depressive disorder (MDD). This study revealed an in-creased density of σ1 receptors in cortico-striato-(para)limbic brain regions of MDD patients. The increased density of σ1 receptors correlated with the severity of the depressive symptoms. In an occupancy study with the PET tracer (S)-[¹⁸F]2, the selective binding of pridopidine at σ1 receptors in the brain of healthy volunteers and HD patients was shown.
Keywords: σ1 receptor ligands; σ1:σ2 selectivity; structure-affinity-relationships; enantioselective synthes
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Pharmaceuticals 17(2024)166, 1-21
DOI: 10.3390/ph17020166
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38198
Added value from residuals: Potentials and relevance for circular economy
Abstract
The talk focusses on metal resources, their applications and their recovery from end-of-life products.
Keywords: metal resources; recycling; biological recycling tools
-
Invited lecture (Conferences)
Internationales Dresdner Leichtbausymposium, 22.-23.06.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38197
Wie Biologie beim Recycling hilft
Abstract
Neuste biotechnologische Methoden nutzen Biolaugung, Biosorption und Bioflotation, um die eher klassisch ausgerichteten Industriezweige Bergbau und Mülltrennung zu ergänzen. In der Abteilung Biotechnologie am Helmholtz Institut Freiberg für Ressourcentechnologie werden durch die Kombination von Biotechnologie mit verschiedenen klassischen Wissenschaften neue Lösungen für bisher ungelöste Probleme und neue Abfallströme gefunden.
Keywords: Biolaugung; Biosorption; Bioflotation
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Invited lecture (Conferences)
Tag der Wissenschaft, 25.05.2023, Radebeul, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38196
Bio-based microplastic detection and separation
Abstract
Identification of microplastic binding peptides and their application in Microplastic detection assays.
Keywords: microplastics; peptides; biodegradation; detection assay
-
Lecture (others)
PRIORITY Training School, 22.-26.05.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38195
How Biology helps in Recycling of Metals for Renewables
Abstract
Presentation of novel recycling tools developed at HIF Biotechnology to recover valuables for renewables.
Keywords: metal resources; recycling; biotechnology; BioKollekt
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Invited lecture (Conferences)
Building Bridges for the next Generations, 16.-17.05.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38194
A convolutional neural network for respiratory motion correction in PET
Rosin, B.; Nikulin, P.; Hofheinz, F.; Maus, J.; Braune, A.; Kotzerke, J.; van den Hoff, J.
Abstract
Breathing related patient motion is a serious source of image blurring in oncological PET. Respiratory gating allows to subdivide the acquisition data into temporal bins ("gates") depending on the breathing cycle which are basically motion-free but exhibit increased noise levels. Image registration of all gates to a reference gate and subsequent averaging is possible but traditional registration algorithms are frequently slow or of limited accuracy. Deep learning methods have recently attracted much interest and have been successfully applied to image registration tasks. Their flexibility and execution speed are especially attractive in the present context. We have therefore implemented and evaluated an unsupervised deep learning framework for the registration of gated PET images.
Image volume pairs consisting of a fixed gate and a second moving gate serve as input to a U-Net convolutional neural network which predicts a deformation vector field (DVF) mapping the moving image to the fixed image. The network is trained unsupervised by optimizing a similarity metric between the registered image pairs as well as an additional regularization loss. Fifty-two gated PET scans (8 gates) were available for training (N=42; 2352 gate pairs) and testing (N=10). Normalized cross correlation (NCC) was used as a measure of registration accuracy. The motion corrected images were compared to the respective ungated image, single reference gate and a commercially available motion correction method (OncoFreeze, Siemens). Lesion SUVmax and noise
levels in the liver were determined.
Our method achieved visually very satisfactory motion compensation and consequently improved NCC for all test scans (by 4.9% on average). Motion artifacts were substantially reduced while maintaining the noise level of the
ungated images.
The proposed framework is suitable for efficient reduction of motion artifacts in PET and is competitive to the OncoFreeze method.
Keywords: CNN; gates; motion correction; PET; registration; unsupervised
-
Lecture (Conference)
2023 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room Temperature Semiconductor Detector Conference, 04.-11.11.2023, Vancouver, Canada
Permalink: https://www.hzdr.de/publications/Publ-38193
Identification of yttrium oxide-specific peptides for future recycling of rare earth elements from electronic scrap
Maass, D.; Boelens, P.; Bloß, C.; Claus, G.; Harter, S. D.; Günther, D.; Pollmann, K.; Lederer, F.
Abstract
Yttrium is a heavy rare earth element that acquires remarkable characteristics when it is in oxide form and doped with other rare earth elements. Owing to these characteristics Y2O3 can be used in the manufacture of several products. However, a supply deficit of this mineral is expected in the coming years, contributing to its price fluctuation. Thus, developing an efficient, cost-effective, and eco-friendly process to recover Y2O3 from secondary sources has become necessary. In this study, we used phage surface display to screen peptides with high specificity for Y2O3 particles. After three rounds of enrichment, a phage expressing the peptide TRTGCHVPRCNTLS (DM39) from the random pVIII phage peptide library Cys4 was found to bind specifically to Y2O3, being 531.6-fold more efficient than the wild-type phage. The phage DM39 contains two arginines in the polar side chains, which may have contributed to the interaction between the mineral targets. Immunofluorescence assays identified that the peptide’s affinity was strong for Y2O3 and negligible to LaPO4:Ce3+,Tb3+. The identification of a peptide with high specificity and affinity for Y2O3 provides a potentially new strategic approach to recycle this type of material from secondary sources, especially from electronic scrap.
Keywords: e-waste; mineral binding peptides; next-generation sequencing; phage surface display; waste of electrical and electronic equipment
Related publications
-
Data publication - Danielle Maass and BioKollekt article 2024: Identification …
ROBIS: 38423 HZDR-primary research data are used by this (Id 38192) publication
-
Biotechnology and Bioengineering 121(2024)3, 1026-1035
DOI: 10.1002/bit.28629
Cited 1 times in Scopus
Downloads
- Final Draft PDF 346 kB Secondary publication
Permalink: https://www.hzdr.de/publications/Publ-38192
A first-principles study on the CdS-Te van der Waals heterostructure for Photocatalytic Hydrogen Production
Tejaswini, G.; Sudheer, A. E.; Devaraj, M.; Posselt, M.
Abstract
Two dimensional (2D) materials are showing advantageous electronic and optical properties compared to their bulk counterparts. Recently 2D heterostructures attracted much attention in catalysis. Here, we demonstrate novel chalcogen based 2D-2D heterostructure CdS-Te with improved efficiency for the water splitting hydrogen production. We analysed the structural, electronic and optical properties of this CdS-Te heterostructure using first principles DFT calculations. Compared with the pristine monolayers of Te and CdS, we noticed significant improvement in the solar visible light absorption, and charge transfer properties in the material after heterostructure construction. This is due to the electric field created at the interface of CdS and Te monolayers. To attain the favorable band alignment for the water redox reaction, we applied the biaxial strain and electric field on the CdS-Te heterostructure. The Gibbs free energy calculations also exhibit less energy barrier for the CdS-Te heterostructure. From the obtained results, it is observed that the applied biaxial strain followed by the heterostructure construction improved the photocatalytic water splitting capacity of the material proficiently.
Keywords: 2D materials; van der Waals heterostructures; CdS-Te; DFT calculations
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Poster
"Recent Progress in Graphene and 2D materials Research” (RPGR) 2023, 20.-23.11.2023, Bengaluru, India
Permalink: https://www.hzdr.de/publications/Publ-38191
DFT Insight into the Photocatalytic Properties of PtSSe-Se vdW Heterostructure
Sudheer, A. E.; Devaraj, M.; Posselt, M.
Abstract
Inspired by the high photoconversion efficiency of 2D nanomaterials, we designed novel vdW heterostructure PtSSe-Se for the solar mediated photocatalytic hydrogen production. We investigated basic electrical and optical characteristics using ab-initio Density Functional Theory (DFT) calculations. Further, we performed electrostatic potential calculation to evaluate band alignments of PtSSe and Se, which revealed the water splitting capacity of the heterostructure. Later, the Gibbs free energy analysis also shows the heterostructure construction reduced the barrier height for the water reduction reaction effectively. Our in-depth investigation revealed the synergistic effect of built in electric field in the Janus PtSSe structure as well as generated electric field due to the heterostructure model have significant role in improving the photocatalytic efficiency. The dual electric field creation due to this unique structure effectively suppressed the charge carrier recombination and lead to enhanced lifetime of charge carriers in this PtSSe-Se heterostructure. In addition to that, the decreased lattice mismatch, elevated visible light response and fast charge transfer are the other factors that enhanced the photocatalytic efficiency of this Janus-chalcogenide heterostructure in a better way.
Keywords: 2D materials; van der Waals heterostructures; PtSSe-Se; DFT calculations
-
Poster
Recent Progress in Graphene and 2D materials Research” (RPGR) 2023, Bengaluru, India, 20.-23.11.2023, Bengaluru, India
Permalink: https://www.hzdr.de/publications/Publ-38190
Graphene Oxide and Bacteria Interactions. What is Known and What Should We Expect?
Simeonova, D.; Pollmann, K.; Bianco, A.; Lièvremont, D.
Abstract
Graphene-based nanomaterials have gained over the last two decades’ considerable attention due to their intrinsic physicochemical properties that are or can potentially be exploited. Besides, a lot of concern regarding the potential toxicity of graphene-based nanomaterials has emerged. One aspect of this concern is the interactions between graphene-based materials and different environmental compartments, especially indigenous microbial communities. As recent research showed that these graphene-based materials impacted bacterial pure culture or bacterial communities, these interactions have to be further studied to better understand and assess the fate of these materials in the environment.
Keywords: Biodegradation; graphene
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mSphere 9(2024)1
DOI: 10.1128/msphere.00715-23
Permalink: https://www.hzdr.de/publications/Publ-38189
Multiphase Experiments and CFD for Nuclear Reactor Safety Research
Abstract
While according to the state of the art safety analyses related to nuclear reactor thermal hydraulics are done using system codes, CFD becomes more and more important as a tool to support such analyses. Often multiphase flows are involved in the flow situations that have to be considered. Since the Euler-Euler CFD modelling is not yet mature, experiments are necessary to improve and validate the CFD models.
This lecture will discuss typical topics of Nuclear Reactor Safety (NRS) research related to multiphase CFD. Several experiments done at the TOPFLOW facility of Helmholtz-Zentrum Dresden – Rossendorf (HZDR) to support the qualification of multiphase CFD for safety related issues will be presented. This includes information on the applied two-phase flow measuring techniques. The experiments range from rather generic experiments investigating vertical pipe flows at parameters relevant for safety analyses to experiments that represent specific safety related scenarios. Examples of the latter are counter-current flow limitation in a hot leg model and experiments on a model of a PWR cold leg and downcomer simulator. Finally, the applicability of Open Source codes for nuclear reactor safety research will be discussed and a German project to establish a validated CFD-tool based on OpenFOAM will be presented.
Keywords: CFD; multiphase; experiments; measuring techniques
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Lecture (others)
Advanced nuclear energy technology and nuclear safety, 14.-17.11.2023, Xi'an, China
Permalink: https://www.hzdr.de/publications/Publ-38188
Euler-Euler CFD Modelling for Multiphase Flows
Abstract
Computational Fluid Dynamics (CFD) becomes more and more important for industrial process design and optimisation as well as analyses related to safety issues. While CFD is an established tool for single phase flows, e.g. in automotive or aviation industries, it is not yet mature for multiphase flows. The main reason is the complexity and multiscale nature of the interactions between the phases.
For medium and large industrial scales, as they are typical for nuclear reactor safety research, the multi-fluid or Euler-Euler approach is most frequently used and often the only feasible one. It allows for relative large sizes of the numerical cells, but has the price that all the unresolved phenomena have to be considered by closure models. The accuracy of these closure models is still limited because of a lack of knowledge and data for the small scale phenomena of multiphase flows.
The lecture will focus on gas-liquid flows and present strategies to 1) improve the reliability of Euler-Euler-CFD simulations and 2) extent the range of applicability of CFD by considering different morphologies of multiphase flows and allowing for transitions between these morphologies.
Keywords: CFD; multiphase; Euler-Euler
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Lecture (others)
Advanced nuclear energy technology and nuclear safety, 14.-17.11.2023, Xi'an, China
Permalink: https://www.hzdr.de/publications/Publ-38187
Novel Deep Learning Algorithms for Microscopy and Where to Find Them in Clinics
Abstract
ML and DL are revolutionising our abilities to analyse biomedical images. Among other host-pathogen interactions may be readily deciphered from microscopy data using convolutional neural networks (CNN). We demonstrate in several studies how the definition of novel ML/DL tasks may aid in studying infection and disease phenotypes. Specifically, ML/DL algorithms may allow unambiguous scoring of virus-infected and uninfected cells in the absence of specific labelling. Accompanied by interpretability approaches, the ability of CNN to learn representations, without explicit feature engineering, may allow for uncovering yet unknown phenotypes in microscopy. Furthermore, we demonstrate novel ML/DL approaches to simplified 3D microscopy acquisition using conventional 2D hardware. Taken together, we show novel approaches to established algorithms in Computer Vision and Data Science. Applied to microscopy data, these approaches allow for the extraction of observations from datasets large enough to not be suitable for manual analysis. We argue that this shows that reformulating conventional ML/DL tasks to answer biological questions may facilitate novel discoveries in Infection and Disease Biology.
Keywords: clinical microscopy; deep learning
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Invited lecture (Conferences)
IUGA 48th Annual Meeting 2023, 21.-23.06.2023, Hague, Netherlands
Permalink: https://www.hzdr.de/publications/Publ-38186
Novel machine learning and data science tools to study infection phenotypes in cells
Abstract
Advances in Machine Learning and Deep Learning are revolutionising our abilities to analyse biomedical images. These algorithms may allow unambiguous scoring of virus-infected and uninfected cells in the absence of specific labelling. Furthermore, accompanied by interpretability approaches, the ability of convolutional neural networks to learn representations, without explicit feature engineering, may allow for uncovering yet unknown phenotypes in microscopy. In our recent work, we employ the CapsNet architecture equipped with a discriminator and generator. This allowed us to differentiate between intracellular and extracellular Vaccinia virus particles through a classification task using the discriminator part of the architecture. Additionally, using the generator part we were able to visualise the differences between these particles. Finally, we show how a phenotype-centric open-source Python package we developed can facilitate the data science work on virological plaque assay. We designed the package to provide biologists with tools that make phenotypes as intuitive as data frames. We show that our phenotype-centric library can be employed for a range of pathogens like Vaccinia virus or Coronavirus, as well as variations of virological plaque assay including fluorescence-based or crystal violet staining-based assay images.
Keywords: deep learning; virology; high-content imaging; microscopy
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Invited lecture (Conferences)
COVID-19 Workshop: lessons learned from the pandemic, 05.-7.06.2023, Goerlitz, Germany
Permalink: https://www.hzdr.de/publications/Publ-38185
Precipitation Stripping of V(V) as a Novel Approach for the Preparation of Two-Dimensional Transition Metal Vanadates
Guadalupe Sánchez-Loredo, M.; Chekhonin, P.; Ebert, D.; Fischer, U.; Liu, X.; Möckel, R.; Judith Labrada-Delgado, G.; Passerini, S.; Kelly, N.
Abstract
Cobalt, nickel, manganese and zinc vanadates were synthesized by a hydrometallurgical two-phases method. The extraction of vanadium(V) ions from alkaline solution using Aliquat®336
was followed by the production of metal vanadates through precipitation stripping. Precipitation stripping was carried out using solutions of the corresponding metal ions (Ni(II), Co(II), Mn(II) and Zn(II), 0.05 mol/L in 4 mol/L NaCl), and the addition time of the strip solution was varied (0, 1 and 2 h). The time-dependent experiments showed a notorius influence on the composition, structure, morphology and crystallinity of the two-dimensional vanadate products. Inspired by these findings, we selected two metallic vanadate products and studied their properties as alternative cathode materials for nonaqueous sodium and lithium metal batteries.
Keywords: two-dimensional materials; transition metal vanadates; solvent extraction; precipitation stripping; cathode materials; batteries
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Nanomaterials 14(2024), 38
Online First (2023) DOI: 10.3390/nano14010038
Permalink: https://www.hzdr.de/publications/Publ-38184
Colouring impurities removal and feldspar flotation using pneumatic ImhoflotTM H-Cell
Hoang, D. H.; Huber, S.; Imhof, R.; Rudolph, M.
Abstract
The beneficiation of feldspar ore typically consists of desliming, magnetic separation, high solids conditioning, and flotation. Depending on the mineral composition, different flotation processes could be applied, i.e., double-reverse or reverse-direct flotation to remove the colouring impurities such as mica, Fe-bearing minerals, rutile, clay etc. and float feldspar from feldspar-quartz. Applications of 60 m3/h semi-industrial ImhoflotTM H-16 cell demonstrated its ability to achieve high feldspar grade and recovery in only one single cell which is compared to the existing bank mechanical cells. For oxide flotation, the underflow product contains 0.048 % Fe2O3 which is slightly higher than 0.043 % Fe2O3 using four industrial cells. The feldspar concentrate grade of one H-Cell is 93.7 % is similar to the existing flotation circuit, including rougher, scavenger and cleaner banks, even the feldspar feed grade fed to the pilot plant was only 38.7 % compared to 63.9 % in the industrial flotation circuit.
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Poster
Flotation '23 Conference, 06.-09.11.2023, Cape Town, South Africa
Permalink: https://www.hzdr.de/publications/Publ-38183
Novel application of pneumatic flotation cell for efficient graphite recovery from black mass: advancing critical raw material recycling
Vanderbruggen, A.; Salces, A. M.; José Rodríguez-Medina, A.; Rudolph, M.; Hoang, D. H.
Abstract
Black mass, the fine fraction from spent Li-ion batteries, needs to be recycled both for its valuable metal oxides and spheroidized graphite particles. Still, current recycling techniques show less preference for graphite, despite being a critical raw material, due to lower economic incentives. Flotation is a suitable and cost-efficient process for graphite recovery before downstream processing, however its effective separation from the black mass is hindered by the (ultra)fine particles. To address this challenge, a pneumatic ImhoflotTM cell is employed in this study. The cell utilizes high-shear turbulence to generate fine bubbles, facilitating dispersion/de-agglomeration of particles and removal of adhered slimes, enhancing reagent selectivity, and reducing dosing requirements. ImhoflotTM cell offers advantages over mechanical and column flotation, including increased recovery of fine particles, rapid flotation kinetics, and high attachment rates and reducing the fine entrained metal oxides particles into the concentrate. This research presents a promising approach for efficient graphite recovery from spent Li-ion batteries, securing the sustainable recycling of critical raw materials.
Involved research facilities
- Metallurgy Technical Centre
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Lecture (Conference)
Flotation '23 Conference, 06.-09.11.2023, Cape Town, South Africa
Permalink: https://www.hzdr.de/publications/Publ-38182
Fused beads for the analysis of Li bearing samples by LIBS and XRF
Ebert, D.; Möckel, R.; Renno, A.; Schneider, A.; Dittrich, T.
Abstract
In recent decades, it has become apparent that due to the increasing complexity of deposits, the complexity of ore samples is also increasing. At the same time, the need for detailed geological and mineralogical information also increased. Therefore, it is important to combine methods in order to obtain more comprehensive conclusions.
We present a method of combining WDXRF (wavelength dispersive X-ray fluorescence) analyses with a wide spectrum of elements and pLIBS (portable laser induced breakdown spectroscopy, see Fig. 1) with a likewise spectrum and the additional possibility to detect light elements such as Li. Nevertheless, the representativeness of LIBS analyses is significantly smaller compared to XRF. To overcome this and effectively combine both methods, we designed and produced fused beads using Na2B4O7 as flux. Unfortunately, such beads are transparent to the laser which makes LIBS analysis almost impossible, therefore, we tested two different approaches: 1) dying the bead by adding CuO to the flux and 2) roughen the beads surface. We used a mixture of Na2B4O7 (+ CuO) + KI as matrix. Potassium iodide (KI) was added as a releasing agent. We used Greisen rocks from the Altenberg-Zinnwald district with known composition – including Li – and LiBO2 in different concentration ratios to adjust the Li content.
To produce crack-free beads, we had to adapt the melting process in the fully automatic melting furnace TheOx (CLAISSE). For the analytical work, we use a portable LIBS instrument manufactured by SciAps (Z-300, laser wavelength 1064 nm) and a PANalytical Axiosmax minerals XRF spectrometer.
The fused beads will now serve as calibration samples for both XRF and LIBS measurements (see Fig. 2). Samples with unknown composition will be analysed by XRF first. It turned out that roughening the beads has no significant influence on the XRF-spectra as revealed in before and after scan measurements. In a second step the LIBS analysis is performed in particular for light element determination such as Li. Furthermore, adding a dying component such as Cu might be suitable as a robust internal standard for both LIBS and XRF.
The obvious disadvantage of the method is that neither Cu, K nor Na can be included in the quantitative analysis. Depending on the analytical problem, they would have to be determined in a preceding step (e.g. via a conventional Li-borate melt and XRF).
Keywords: LIBS; XRF; Lithium
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Poster
MinWien2023, 17.-21.09.2023, Wien, Österreich
Permalink: https://www.hzdr.de/publications/Publ-38181
Application of pneumatic ImhoflotTM G-Cell in recovering fine particles: A case study of KGHM copper ore
Hoang, D. H.; Kurzydło, P.; Kwiatkowski, P.; Imhof, R.; Hassanzadeh, A.; Pereira, L.; Rudolph, M.
Abstract
The depletion of deposits and ever-increasing metal demand requires the processing of low-grade, complex, and finely disseminated ores and reprocessing of tailings. Even though flotation is capable of handling relatively fine particles, the use of conventional tank cells is limited in such cases. This study presents the results of applying a semi-industrial pneumatic G-Cell (tangential feed to the separator vessel with 1.4 m diameter, throughput is 20 - 30 m3/h) at KGHM Polkowice plant, one of the biggest copper concentrators in Europe. The testworks were conducted on three streamlines i.e., scavenger, cleaner, and final tailings using four different aerator designs with different operating parameters (feed flowrate, air flowrate, and recycling load). It demonstrated that G-Cell with advanced aerator concepts can be applied for plant expansions and retrofits to existing conventional cells to improve flotation performance, especially to reduce losses of fine copper-bearing particles to tailings.
Keywords: fine particle flotation; aerator/reactor–separator; fine bubbles; entrainment; reprocessing tailings; high-shear
Involved research facilities
- Metallurgy Technical Centre
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Contribution to proceedings
MEI Flotation '23 Conference, 06.-09.11.2023, Cape Town, South Africa
Permalink: https://www.hzdr.de/publications/Publ-38180
Data-driven Simulation of Target Normal Sheath Acceleration by Fourier Neural Operator
Rustamov, J.; Stiller, P.; Miethlinger, T.; Kluge, T.; Bussmann, M.; Hoffmann, N.
Abstract
Particle-in-Cell simulations are a ubiquitous tool for linking theory and experimental data in plasma physics rendering the comprehension of non-linear processes such as Laser Plasma Acceleration (LPA) feasible. These numerical codes can be considered as state-of-the-art approach for studying the underlying physical processes in high temporal and spatial resolution. The analysis of experiments is performed by optimising simulation parameters so that the simulated system is able to explain experimental results. However, a high spatio-temporal resolution comes at the cost of elevated simulation times which makes the inversion nearly impossible. We tackle that challenge by introducing and studying a reduced order model based on Fourier neural operator that is evolving the ion density function of Laser-driven Ion acceleration via 1D Target Normal Sheath acceleration (TNSA). The ion density function can be dynamically generated over time with respect to the thickness of the target. We show that this approach yields a significant speed-up compared to numerical code Smilei while retaining physical properties to a certain degree promising applicability for inversion of experimental data by simulation-based inference.
Involved research facilities
- Data Center
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Lecture (Conference)
Helmholtz AI Conf 2023, 12.-14.06.2023, Hamburg, Deutschland -
Lecture (Conference)
SMuK DPG conference, 20.-24.03.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38179
Application of a self-aspirated ImhoflotTM H-16-Cell in a copper flotation circuit
Hassanzadeh, A.; Ali Cinar, Y.; Gungor, E.; Hoang, D. H.
Abstract
The current work investigates the application of one H-16 cell (hybrid ImhoflotTM cell) positioning at four different stages in the Gökirmak copper flotation circuit of the Acacia (Türkiye) copper beneficiation plant. For this purpose, hourly-based samples were taken from selective streams during three shifts after installing the H-16 cell. The pneumatic flotation cell was situated at i) pre-flotation, ii) rougher, iii) cleaner-scavenger tailing, and iv) first cleaning aiming at enhancing the flotation circuit capacity through flash flotation in the rougher stage, reducing copper grade in the final tailing, and increasing cleaning throughput, respectively. All operations were performed at the fresh feed capacity of 15-40 m3/h at the neutral pH range of 7.5-8 and solid content of 20-30% (w/w) using potassium amyl xanthate (PAX) as the main collector (130-150 g/t). The pilot test results indicated that locating one pneumatic cell with the duty of pre-floating led to the enrichment ratio and recovery of 4.84 and 89%, respectively. Positioning the pneumatic cell at the cleaner-scavenger tailing could diminish the copper tailing grade from 0.43% to 0.31%. Further, it was shown that the enrichment ratios using only one ImhoflotTM cell were relatively better (1.76 vs 1.45) than four tanks in the operation of mechanical cells at the first cleaner stage. Corresponding recoveries of 64% and 60% were obtained through the pneumatic cell and the mechanical ones.
Keywords: ImhoflotTM H-16-Cell; copper grade and recovery; enrichment ratio; cleaning flotation stage
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Contribution to proceedings
28th International Mining Congress and Exhibition of Türkiye - IMCET 2023, 28.11.-01.12.2023, Ankara, Turkey
Proceedings of the 28th International Mining Congress and Exhibition of Turkey, 78-605-01-1589-5
Permalink: https://www.hzdr.de/publications/Publ-38178
Flotation of apatite and REEs as co-products from a Vietnamese sedimentary phosphate ore rich in carbonate and finely intergrowth
Hoang, D. H.; Pereira, L.; Rudolph, M.
Abstract
Vietnamese phosphate deposits are of marine sedimentary origin and one of the largest phosphate rock deposits of Southeast Asia. Lao Cai phosphate reserves have been estimated at about 526 million tonnes with hypothetical reserves of about 2.6 billion tonnes. Froth flotation is considered the most effective process for the beneficiation of phosphate ore, with more than 60 % (140 million tons per year) of the marketable phosphate in the world being processed by flotation. However, for finely disseminated sedimentary carbonaceous phosphate ores, flotation is facing various challenges due to similarities in surface properties of the semi-soluble salt-type carbonate and phosphate calcium minerals. Many processes and reagents have been developed to separate carbonates from carbonaceous phosphate ores, however with limited success. This paper will present the effect of hydrodynamics parameters, particle size, liberation and association on flotation performance using automated mineralogy and machine learning. Also, through a combination of time-resolved dynamic froth analysis (DFA) and automated mineralogy (MLA) the effects governing in the froth with different flotation times have been identified and compared with the entrainment results of existing models. Significantly changing pulp and froth properties with time was found due to decreasing reagent and particle concentrations when processing high-grade ores in lab-scale batch flotation testwork. Furthermore, Lao Cai phosphate ores contain about 200 g/t rare earth elements (REEs) which are enriched by froth flotation via co-flotation of the REEs-bearing apatite that could be considered as a secondary REEs source as the large tonnages of phosphate rock mined and processed annually.
Keywords: carbonaceous apatite; rare earth elements (REEs); fine particle flotation; finely disseminated
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Lecture (Conference)
Beneficiation of Phosphates IX, 05.-10.06.2022, Helsinki, Finland
Downloads
Permalink: https://www.hzdr.de/publications/Publ-38177
Increasing resource efficiency in the mining industry: sustainability assessment of Grecian Magnesite case study
Rigamonti, L. E.; Hazem, C.; Giuseppe, Y.; Haris, H.; Hoang, D. H.
Abstract
Separation by flotation is one of the common technologies used during beneficiation stage in mining industry, aiming at concentrating valuable minerals for downstream refining stages. Currently a new froth flotation technology is being developed under FineFuture (FF) project, funded by the European Union Horizon 2020 research and innovation programme (grant agreement No 821265). If implemented, this technology can valorise fine mineral particles instead of discarding them as residues, nevertheless this does not necessarily ensure the sustainability of the technology.
To verify this, a sustainability assessment has been performed for one of the project case studies, i.e. the one that involves the industrial partner Grecian Magnesite (GM). GM is a Greek mining company specialized in magnesite concentrate (MgCO3) and magnesia production (MgO). The beneficiation plant under study is in Yerakini Mines and Works in Chalkidiki, Greece.
The aim of the sustainability assessment is the comparison between the current beneficiation system of GM with the future one that will have FF flotation implemented on full scale to benefit from the very fine particles with granular size < 4 mm that are currently discarded as waste.
The sustainability assessment has been performed considering the three pillars of sustainability. For the environment, a comparative Life Cycle Assessment (LCA) has been carried out, whereas the Material Flow Cost Accounting (MFCA) methodology has been applied to evaluate the economic costs. To assess the potential social risks that must be tackle when implementing the new technology, a Social Hotspot analysis has been carried out, taking into account the Other Mining and Quarriyng sector in Greece (NACE rev. 2) and using the PSILCA database.
The presentation will show the main results of the assessment, together with the challenges of an evaluation of this type, both technical and methodological: in fact, both the technology under assessment and the methodology itself for the assessment are still under development.
Keywords: Sustainability assessment; mining solid waste; emerging technology; froth flotation
Involved research facilities
- Metallurgy Technical Centre
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Lecture (Conference)
(Online presentation)
The Role of LCA in Raw Material Sustainability, Circularity and Criticality, 12.-14.10.2022, Virtual Event, Belgium
Downloads
Permalink: https://www.hzdr.de/publications/Publ-38176
Impact of hyperfine contributions on the ground state of spin-ice compounds
Gronemann, J.; Chattopadhyay, S.; Gottschall, T.; Osmic, E.; Islam, A. T. M. N.; Anand, V. K.; Lake, B.; Kaneko, H.; Suzuki, H.; Wosnitza, J.; Herrmannsdörfer, T.
Abstract
We examined the magnetic ground state of the pyrochlore spin-ice compounds Pr2Hf2O7 and Ho2Ti2O7 by means of specific-heat, magnetization, and ac-susceptibility measurements in the mK regime. At these low temperatures, we observe an unexpected large specific heat and corresponding entropy, which diminish in applied magnetic fields. This evidences the presence of additional states beyond the electronic spin and orbital degrees of freedom. We can qualitatively explain the large specific heat by the coupling of the nuclear spins of 141Pr and 165Ho with their electronic counterparts, which leads to a complex hyperfine-coupled term scheme. With increasing fields, the nuclear and electronic spins decouple leaving only the electronic excitations in the measured temperature window. At intermediate fields, a rather evolved term scheme emerges that may explain the unusual hysteretic magnetization and a remarkable state with a negative magnetization found for Ho2Ti2O7. Our findings bring deep insights to the complex ground state of pyrochlore spin-ice compounds and their low-energy excitations.
Involved research facilities
- High Magnetic Field Laboratory (HLD)
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Physical Review B 108(2023), 214412
DOI: 10.1103/PhysRevB.108.214412
Downloads
- Final Draft PDF 3 MB Secondary publication
Permalink: https://www.hzdr.de/publications/Publ-38175
Field-induced compensation of magnetic exchange as the possible origin of reentrant superconductivity in UTe2
Helm, T.; Kimata, M.; Sudo, K.; Miyata, A.; Stirnat, J.; Förster, T.; Hornung, J.; König, M.; Sheikin, I.; Pourret, A.; Lapertot, G.; Aoki, D.; Knebel, G.; Wosnitza, J.; Brison, J.-P.
Abstract
The potential spin-triplet heavy-fermion superconductor UTe2 exhibits signatures of multiple distinct superconducting phases. For field aligned along the b axis, a metamagnetic transition occurs at μ0Hm ≈ 35 T. It is associated with magnetic fluctuations that may be beneficial for the field-reinforced superconductivity surviving up to Hm. Once the field is tilted away from the b towards the c axis, a reentrant superconducting phase emerges just above Hm. In order to better understand this remarkably field-resistant superconducting phase, we conducted magnetic-torque and magnetotransport measurements in pulsed magnetic fields. We determine the record-breaking upper critical field of μ0Hc2 ≈ 73T and its evolution with angle. Furthermore, the normal-state Hall effect experiences a drastic suppression indicative of a reduced band polarization above Hm in the angular range around 30° caused by a partial compensation between the applied field and an exchange field. This promotes the Jaccarino-Peter effect as a likely mechanism for the reentrant superconductivity above Hm.
Involved research facilities
- High Magnetic Field Laboratory (HLD)
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Nature Communications 15(2024), 37
DOI: 10.1038/s41467-023-44183-1
arXiv: arXiv:2207.08261
Cited 8 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38174
Neutron radiography of an anisotropic drainage flow
Skrypnik, A.; Cole, K.; Lappan, T.; Brito-Parada, P. R.; Neethling, S. J.; Trtik, P.; Eckert, K.; Heitkam, S.
Abstract
The data set includes original data for the paper "Neutron radiography of an anisotropic drainage flow".
Keywords: drainage; foam; neutron radiography; anisotropic draiange
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Physical Review E 109(2024)1, 014609
DOI: 10.1103/PhysRevE.109.014609
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38173
alpaka-group/alpaka: alpaka 1.0.0: The One Release
Bastrakov, S.; Bastrakova, K.; Bocci, A.; Di Pilato, A.; Ehrig, S.; Ferragina, L.; Gruber, B. M.; Kaever, C.; Kelling, J.; Martin-Haugh, S.; Perego, A.; Stephan, J.; Widera, R.; Young, J.
Abstract
The alpaka library is a header-only C++17 abstraction library for accelerator development. Its aim is to provide performance portability across accelerators through the abstraction (not hiding!) of the underlying levels of parallelism.
Keywords: CUDA; HPC; alpaka; OpenMP; HIP; C++; GPU; heterogeneous computing; performance portability; FPGA; SYCL
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Software in external data repository
Publication year 2023
Programming language: C++
System requirements: OS: Linux, Windows, or macOS Software requirements: C++17 compiler, Boost 1.74.0+, CMake 3.22+
License: MPL-2.0 (Link to license text)
Hosted on GitHub: Link to location
DOI: 10.5281/zenodo.4452613
Permalink: https://www.hzdr.de/publications/Publ-38172
Leveraging Automatic Differentiation in Complex Model Fitting
Thiessenhusen, E.; Aguilar, R. A.; Smid, M.; Bussmann, M.; Kluge, T.; Cowan, T.; Huang, L.; Hoffmann, N.; Kelling, J.
Abstract
Understanding laser-solid interactions is important for the development of laser-driven particle and photon sources, e.g., tumor therapy, astrophysics, and fusion. Currently, these interactions can only be modeled by simulations that need to be verified experimentally. Consequently, pump-probe experiments were conducted to examine the laser-plasma interaction that occurs when a high intensity laser hits a solid target. Since we aim for a femtosecond temporal and nanometer spatial resolution at European XFEL, we employ Small-Angle X-ray Scattering (SAXS) and Phase Contrast Imaging (PCI) that can each be approximated by an analytical propagator. In our reconstruction of the target, we employ a gradient descent algorithm that iteratively minimizes the error between experimental and synthetic patterns propagated from proposed target structures. By implementing the propagator in PyTorch we leverage the automatic differentiation capabilities, as well as the speed-up by computing the process on a GPU. We perform a scan of different initial parameters to find the global minimum, which is accelerated by batching multiple parallel reconstructions. The fully differentiable implementation of a forward function may serve as a physically-constraining loss, enabling training with unpaired data or unsupervised training of neural networks to predict the initial parameters for the gradient descent fit.
Involved research facilities
- HIBEF
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Poster
From Matter to Materials and Life, 27.-29.09.2023, Jena, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38170
Prediction of radiation pneumonitis using the effective α/β of lungs and heart in NSCLC patients treated with proton beam therapy
Weiß, A.; Löck, S.; Xu, T.; Liao, Z.; Hoffmann, A. L.; Troost, E. G. C.
Abstract
Purpose: Radiation pneumonitis (RP) remains a major complication in non-small cell lung cancer (NSCLC) pa-
tients undergoing radiochemotherapy (RCHT). Traditionally, the mean lung dose (MLD) and the volume of the
total lung receiving at least 20 Gy (V20Gy) are used to predict RP in patients treated with normo-fractionated
photon therapy.
However, other models, including the actual dose-distribution in the lungs using the effective α/β model or a
combination of radiation doses to the lungs and heart, have been proposed for predicting RP. Moreover, the
models established for photons may not hold for patients treated with passively-scattered proton therapy (PSPT).
Therefore, we here tested and validated novel predictive parameters for RP in NSCLC patient treated with PSPT.
Methods: Data on the occurrence of RP, structure files and dose-volume histogram parameters for lungs and heart
of 96 NSCLC patients, treated with PSPT and concurrent chemotherapy, was retrospectively retrieved from
prospective clinical studies of two international centers. Data was randomly split into a training set (64 patients)
and a validation set (32 patients). Statistical analyses were performed using binomial logistic regression.
Results: The biologically effective dose (BED) of the’lungs - GTV’ significantly predicted RP ≥ grade 2 in the
training-set using both a univariate model (p = 0.019, AUCtrain = 0.72) and a multivariate model in combination
with the effective α/β parameter of the heart (pBED = 0.006, pα/βeff = 0.043, AUCtrain = 0.74). However, these
results did not hold in the validation-set (AUCval = 0.52 andAUCval = 0.50, respectively). Moreover, these models
were found to neither outperform a model built with the MLD (p = 0.015, AUCtrain = 0.73, AUCval = 0.51), nor a
multivariate model additionally including the V20Gy of the heart (pMLD = 0.039, pV20Gy,heart = 0.58, AUCtrain =
0.74, AUCval = 0.53).
Conclusion: Using the effective α/β parameter of the lungs and heart we achieved similar performance to
commonly used models built for photon therapy, such as MLD, in predicting RP ≥ grade 2. Therefore, prediction
models developed for photon RCHT still hold for patients treated with PSPT.
Keywords: NTCP; NSCLC; PSPT; Radiation pneumonitis; Effective α/β
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Radiotherapy and Oncology 190(2024), 110013
Online First (2023) DOI: 10.1016/j.radonc.2023.110013
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38169
A Phase I Study of the DNA-PK Inhibitor Peposertib in Combination with Radiotherapy with or without Cisplatin in Patients with Advanced Head and Neck Tumors
Samuels, M.; Falkenius, J.; Bar-Ad, V.; Dunst, J.; van Triest, B.; Yachnin, J.; Rodriguez-Gutierrez, A.; Kuipers, M.; You, X.; Sarholz, B.; Locatelli, G.; Becker, A.; Troost, E. G. C.
Abstract
Purpose: DNA-dependent protein kinase (DNA-PK) plays a key role in the repair of DNA double strand breaks via nonho-
mologous end joining. Inhibition of DNA-PK can enhance the effect of DNA double strand break inducing anticancer thera-
pies. Peposertib (formerly “M3814”) is an orally administered, potent, and selective small molecule DNA-PK inhibitor that has
demonstrated radiosensitizing and antitumor activity in xenograft models and was well-tolerated in monotherapy. This phase
1 trial (National Clinical Trial 02516813) investigated the maximum tolerated dose, recommended phase 2 dose (RP2D),
safety, and tolerability of peposertib in combination with palliative radiation therapy (RT) in patients with thoracic or head
and neck tumors (arm A) and of peposertib in combination with cisplatin and curative-intent RT in patients with squamous
cell carcinoma of the head and neck (arm B).
Methods and Materials: Patients received peposertib once daily in ascending dose cohorts as a tablet or capsule in combina-
tion with palliative RT (arm A) or in combination with intensity modulated curative-intent RT and cisplatin (arm B).
Results: The most frequently observed treatment-emergent adverse events were radiation skin injury, fatigue, and nausea in
arm A (n = 34) and stomatitis, nausea, radiation skin injury, and dysgeusia in arm B (n = 11). Based on evaluations of dose-
limiting toxicities, tolerability, and pharmacokinetic data, RP2D for arm A was declared as 200 mg peposertib tablet once daily
in combination with RT. In arm B (n = 11), 50 mg peposertib was declared tolerable in combination with curative-intent RT
and cisplatin. However, enrollment was discontinued because of insufficient exposure at that dose, and the RP2D was not for-
mally declared.
Conclusions: Peposertib in combination with palliative RT was well-tolerated up to doses of 200 mg once daily as tablet with each
RT fraction. When combined with RT and cisplatin, a tolerable peposertib dose yielded insufficient exposure. Ó 2023 The Authors.
Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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International Journal of Radiation Oncology Biology Physics 118(2024)3, 743-756
Online First (2023) DOI: 10.1016/j.ijrobp.2023.09.024
Cited 17 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38168
Patients’ needs in Proton Therapy: a survey among 10 European Facilities
Mazzola, G. C.; Bergamaschi, L.; Vincini, M.; Pepa, M.; Zaffaroni, M.; Volpe, S.; Rombi, B.; Doyen, J.; Fossati, P.; Haustermans, K.; Hoyer, M.; Langendijk, H.; Matute, R.; Orlandi, E.; Rylander, H.; Troost, E. G. C.; Orecchia, R.; Alterio, D.; Jereczek-Fossa, B.
Abstract
Aims: The number of Proton Therapy (PT) facilities is still limited worldwide, and the access to treatment could
be characterized by patients’ logistic and economic challenges. Aim of the present survey is to assess the support
provided to patients undergoing PT across Europe.
Methods: Through a personnel contact, an online questionnaire (62 multiple-choice and open-ended questions)
via Microsoft Forms was administered to 10 European PT centers. The questionnaire consisted of 62 questions
divided into 6 sections: i) personal data; ii) general information on clinical activity; iii) fractionation, concurrent
systemic treatments and technical aspects of PT facility; iv) indication to PT and reimbursement policies; v)
economic and/ or logistic support to patients vi) participants agreement on statements related to the possible
limitation of access to PT. A qualitative analysis was performed and reported.
Results: From March to May 2022 all ten involved centers filled the survey. Nine centers treat from 100 to 500
patients per year. Paediatric patients accounted for 10–30%, 30–50% and 50–70% of the entire cohort for 7, 2
and 1 center, respectively. The most frequent tumours treated in adult population were brain tumours, sarcomas
and head and neck carcinomas; in all centers, the mean duration of PT is longer than 3 weeks. In 80% of cases,
the treatment reimbursement for PT is supplied by the respective country’s Health National System (HNS). HNS
also provides economic support to patients in 70% of centers, while logistic and meal support is provided in 20%
and 40% of centers, respectively. PT facilities offer economic and/or logistic support in 90% of the cases. Logistic
support for parents of pediatric patients is provided by HNS only in one-third of centers. Overall, 70% of re-
spondents agree that geographic challenges could limit a patient’s access to proton facilities and 60% believe that
additional support should be given to patients referred for PT care.
Keywords: Proton therapy Facilities; Europe; Survey; Support strategies; Patients
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Clinical and Translational Radiation Oncology 43(2023), 100670
DOI: 10.1016/j.ctro.2023.100670
Cited 5 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38167
Lung cancer multi-omics digital human avatars for integrating precision medicine into clinical practice: the LANTERN study
Lococo, F.; Boldrini, L.; Diepriye, C.-D.; Evangelista, J.; Nero, C.; Flamini, S.; Minucci, A.; de Paolis, E.; Vita, E.; Cesario, A.; Annunziata, S.; Calcagni, M.; Chiappetta, M.; Cancellieri, A.; Larici, A.; Cicchetti, G.; Troost, E. G. C.; Róza, Á.; Farré, N.; Öztürk, E.; van Doorne, D.; Leoncini, F.; Urbani, A.; Trisolini, R.; Bria, E.; Giordano, A.; Rindi, G.; Sala, E.; Tortora, G.; Valentini, V.; Boccia, S.; Margaritora, S.; Scambia, G.
Abstract
Background The current management of lung cancer patients has reached a high level of complexity. Indeed, besides the traditional clinical variables (e.g., age, sex, TNM stage), new omics data have recently been introduced in clinical practice, thereby making more complex the decision-making process. With the advent of Artificial intelligence (AI) techniques, various omics datasets may be used to create more accurate predictive models paving the way for a
better care in lung cancer patients.
Methods The LANTERN study is a multi-center observational clinical trial involving a multidisciplinary consortium of five institutions from different European countries. The aim of this trial is to develop accurate several predictive models for lung cancer patients, through the creation of Digital Human Avatars (DHA), defined as digital representations of patients using various omics-based variables and integrating well-established clinical factors with genomic data, quantitative imaging data etc. A total of 600 lung cancer patients will be prospectively enrolled by the recruiting centers and multi-omics data will be collected. Data will then be modelled and parameterized in an experimental context of cutting-edge big data analysis. All data variables will be recorded according to a shared common ontology based on variable-specific domains in order to enhance their direct actionability. An exploratory
analysis will then initiate the biomarker identification process. The second phase of the project will focus on creating multiple multivariate models trained though advanced machine learning (ML) and AI techniques for the specific areas of interest. Finally, the developed models will be validated in order to test their robustness, transferability and generalizability, leading to the development of the DHA. All the potential clinical and scientific stakeholders will
be involved in the DHA development process. The main goals aim of LANTERN project are: i) To develop predictive models for lung cancer diagnosis and histological characterization; (ii) to set up personalized predictive models for individual-specific treatments; iii) to enable feedback data loops for preventive healthcare strategies and quality of life management.
Discussion The LANTERN project will develop a predictive platform based on integration of multi-omics data. This will enhance the generation of important and valuable information assets, in order to identify new biomarkers that can be used for early detection, improved tumor diagnosis and personalization of treatment protocols.
Ethics Committee approval number 5420 − 0002485/23 from Fondazione Policlinico Universitario Agostino Gemelli IRCCS – Università Cattolica del Sacro Cuore Ethics Committee.
Trial registration clinicaltrial.gov - NCT05802771.
Keywords: Lung cancer; Artificial intelligence (AI); Digital human avatars (DHA); Personalize medicine; Machine learning; system medicine; precision medicine; genomics; radiomics; big data
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BMC Cancer 23(2023), 540
DOI: 10.1186/s12885-023-10997-x
Cited 9 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38166
Eco-sustainable Printed Magnetoresistance Sensors
Guo, L.; Xu, R.; Oliveros Mata, E. S.; Peng, X.; Das, P. T.; Bao, X.; Veremchuk, I.; Zabila, Y.; Baraban, L.; Makarov, D.
Abstract
As an important member of printed electronics, printed magnetic sensors have revealed potential in industrial production, consumer electronics, etc, relying on large scale, low cost and high production fabrication [1]. However, the excessive use and short lifespan for electronics contribute significantly to the accumulation of electronic waste, meanwhile magnetic sensors usually contain hazardous elements. Therefore, there is a growing demand for eco-sustainable printed magnetoresistance sensors. Firstly, we introduced self-healing property to printed magnetoresistance sensors to extend their lifetime[2]. Take one step further, we designed biocompatible and biodegradable printed magnetic sensors to address the e-waste issues using non-toxic iron particles bonded with edible starch. Benefiting from a completely eco-friendly printing process and food-grade materials, these sensors can be applied not only on conventional substrates but also on surfaces like plants, human skin, and nails, meanwhile demonstrate washability and degradability in aqueous environments. By virtue of these advantages, these magnetic sensors hold promising application in speedometer, IoT, and human-machine interfaces.
[1] D. Makarov et al, ChemPhysChem 2013, 14, 1771.
[2] R. Xu, et al, Nature Communications 2022, 13, 6587.
Keywords: Eco-sustainable; Printed Magnetoresistance Sensors
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Lecture (Conference)
87. Jahrestagung der DPG und DPG-Frühjahrstagung (87. Annual Conference of the DPG and DPG Spring Meeting), 17.-22.03.2024, Berlin, Germany
Permalink: https://www.hzdr.de/publications/Publ-38165
Normo-or hypo-fractionated photon or proton radiotherapy in the management of locally advanced unresectable pancreatic cancer: a systematic review
Elkhamisy, S. A.; Valentini, C.; Lattermann, A.; Radhakrishna, G.; Künzel, L. A.; Löck, S.; Troost, E. G. C.
Abstract
LAPC is associated with a poor prognosis and requires a multimodal treatment approach. However, the role of radiation therapy in LAPC treatment remains controversial. This systematic review aimed to explore the role of proton and photon therapy, with varying radiation techniques and fractionation, in treatment outcomes and their respective toxicity profiles. Methods: Clinical studies published from 2012 to 2022 were systematically reviewed using PubMed, MEDLINE (via PubMed) and Cochrane databases. Different radiotherapy-related data were extracted and analyzed. Results: A total of 31 studies matched the inclusion criteria. Acute toxicity was less remarkable in stereotactic body radiotherapy (SBRT) compared to conventionally fractionated radiotherapy (CFRT), while in proton beam therapy (PBT) grade 3 or higher acute toxicity was observed more commonly with doses of 67.5 Gy (RBE) or higher. Late toxicity was not reported in most studies; therefore, comparison between groups was not possible. The range of median overall survival (OS) for the CFRT and SBRT groups was 9.3–22.9 months and 8.5–20 months, respectively. For the PBT group, the range of median OS was 18.4–22.3 months. Conclusion: CFRT and SBRT showed comparable survival outcomes with a more favorable acute toxicity profile for SBRT. PBT is a promising new treatment modality; however, additional clinical studies are needed to support its efficacy and safety.
Keywords: locally advanced pancreatic adenocarcinoma; photon therapy; SBRT; proton beam therapy; systematic review
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Cancers 15(2023), 3771
DOI: 10.3390/cancers15153771
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38164
CFD simulation of flashing scenarios for nuclear safety analysis: possibilities and challenges
Abstract
Due to its relevance for the safety analysis of pressurized water reactors, many research activities on flashing flows in pipes and nozzles arose from the mid of last century. Most of them have focused on the mass flow rate and pressure or temperature fluctuation by means of experiments and system codes. Owing to the increase in computer speed and progress in numerical algorithm, CFD is used more and more in the investigation of flashing flows, which has the advantage of providing further insights regarding the internal flow structure as well as its evolution. Various mixture or two-fluid models have been proposed in the literature. However, knowledge on local non-equilibrium effects, interphase transfer as well as interfacial area under different flashing conditions is still insufficient; a general and precise definition of the problem remains a challenge. In this lecture, two-fluid modelling of various nuclear flashing scenarios such as pipe blowdown, nozzle flow, steam-generator leakage, flashing-induced instability and pressure release will be presented. The performance of different mass transfer models including thermal phase-change, pressure phase-change, relaxation and equilibrium models will be compared. Challenges related to interfacial heat transfer, bubble poly-dispersity as well as flow regime transition will be discussed.
Keywords: Computational Fluid Dynamics; Flashing flows; Nuclear safety analysis; Challenges
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Lecture (others)
Advanced nuclear energy technology and nuclear safety, 14.-17.11.2023, Xi'an, China
Permalink: https://www.hzdr.de/publications/Publ-38163
Morphology-adaptive simulation of pool-scrubbing hydrodynamics
Liao, Y.; Meller, R.; Krull, B.
Abstract
Pool scrubbing is often used for removing harmful aerosol particles by injecting the gas mixture
into a liquid pool [1], where hydrodynamics affects the decontamination factor significantly. The poolscrubbing
bubble column is characterized by a large nozzle and high injection flow rates, which lead to
large gas structures in the injection zone. As they rise up, these globules break up and form a swarm of
small bubbles. The wide range of bubble size and shape poses a challenge for both two-fluid model
(TFM) and interface-tracking approaches [2].
In this work, we apply the hybrid multi-field two-fluid model MultiMorph [3] to simulate a
rectangular pool-scrubbing bubble column. The MultiMorph model considers the interaction between
the gas and liquid according to the scale of the interfaces, applying a VOF-like treatment at the largescale
interfaces and the conventional TFM to the small-scale ones. In this way, the description of the
topology changes and regime transition is realized with the same set of equations. In the simulation,
both the gas and liquid can be treated as either dispersed or continuous phases depending on the ratio
between the particle (droplet or bubble in this work) size and the local cell size. The capability of the
model is validated by comparing with experimental data from reference [4] as well as results obtained
with the VOF and TFM, respectively. The MultiMorph model turns out to show significantly improved
agreement with experimental data.
Keywords: hybrid multi-field two-fluid; morphology transfer; multiMorph; OpenFOAM; Pool scrubbing
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Lecture (Conference)
International Conference on Numerical Methods in Multiphase Flows 5 -, 26.-28.06.2024, Reykjavik, Iceland
Permalink: https://www.hzdr.de/publications/Publ-38162
Effect of particles on coaxial bubble-pair coalescence in a slurry bubble column
Abstract
Bubble coalescence in three-phase systems is known to be different from that in two-phase ones. Understanding how the coalescence process is affected by particles is of great significance to various engineering applications. Despite decades of research, high-resolution data on the coalescence and film drainage in bubble columns are scarce, which prevents a precise description of the phenomenon and the derivation of reliable models for further analyses. The existing work is either performed under nearly hydrostatic conditions, or limited to the mesoscopic scale, i.e., by acquiring void fraction and bubble size distribution. The present work aims to fill the gap in-between and provide microscopic insights into the bubble-pair coalescence and film drainage under bubble column hydrodynamic conditions. By coupling the volume-of-fluid (VOF) and multiphase particle-in-cell (MPPIC) methods with a chimera mesh approach in OpenFOAM, a high resolution of the gas-liquid interface and fluid flow field is realized and meaningful results on the effect of particles are achieved. In the investigated parameter range, the presence of particles in liquid is found to affect majorly the film drainage process, while has negligible effects on the bubble rise regarding shape and velocity. The results agree well with the observations in previous literature.
Keywords: coaxial bubble-pair coalescence; particle effect; VOF-MPPIC coupled method
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Lecture (Conference)
the 16th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor Engineering (GLS-16), 02.-05.09.2024, Dresden, Germany
Permalink: https://www.hzdr.de/publications/Publ-38161
Planar Hall effect sensors enabling improved Magnetic Particle Tracking
Schmidtpeter, J.; Zabila, Y.; Makarov, D.; Wondrak, T.
Abstract
Magnetic Particle Tracking is able to track the position and orientation of magnetic particles in opaque media by measuring the magnetic field outside the vessel. This technique was already applied in granular flows with a magnet of 8 mm³ volume [1]. The extension of this technique to flotation, which is used in ore processing and recycling, requires magnetic particles in sub-mm range, which float with the foam. The vessel diameter of 100 mm demands for sensors with a resolution in the order of nT. Thin-film sensors reduce the distance from the sensor to the magnet. We will present in detail a newly developed measurement system with an array of 12 tailored planar Hall magnetoresistive sensors with a measurement range from 300 µT down to 10 nT and
demonstrate the reliable detection of the position of a cubic magnet with edge length of 0.4 mm. The sensors consist of single layer permalloy in a 5 ring Wheatstone bridge configuration. Furthermore, we will show preliminary results of an sensor array on a flexible substrate [2],
which can be easily and accurately placed around a complex shaped vessel.
[1] Buist, et al. AIChE Journal 60.9 (2014): 3133-3142.
[2] Granell, et al. npj Flexible Electronics 3.1 (2019): 3.
Keywords: Planar Hall Effect; Magnetic Field Sensor
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Lecture (Conference)
DPG Spring Meeting of the Condensed Matter Section (SKM), 17.-22.03.2024, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38160
An Operator-Independent Quality Assurance System for Automatically Generated Structure Sets
Bookbinder, A.; Bobić, M.; Sharp, G. C.; Nenoff, L.
Abstract
Objective: This paper describes intensity-based tools for quality assurance (QA) of automatically generated structures for online adaptive radiotherapy, and designs an operator-independent traffic light system that identifies erroneous structures.
Approach: A cohort of eight head and neck (HN) patients with daily CBCTs was selected for test development. Radiotherapy contours were propagated from planning CT to daily cone beam CT (CBCT) using deformable image registration (DIR). These propagated structures were visually verified for acceptability. For each CBCT, several error scenarios were used to generate what were judged unacceptable structures. Ten additional HN patients with daily CBCTs were selected for validation and different error scenarios were created for them. A suite of tests based on image intensity, intensity gradient, and structure geometry was developed using acceptable and unacceptable HN planning structures. Structure-test combinations were selected for inclusion in the QA system based on their discriminatory power. A traffic light system was used to aggregate the structure-test combinations, and the system was evaluated on all fractions of the ten validation HN patients.
Results: The QA system distinguished between acceptable and unacceptable fractions with high accuracy, labeling 294/324 acceptable fractions as green or yellow and 19/20 unacceptable fractions as yellow or red.
Significance: This study demonstrates a system to supplement manual review of radiotherapy planning structures. Automated QA is performed by aggregating results from multiple intensity- and geometry-based tests.
Keywords: Adaptive radiotherapy; adaptive proton therapy; Deformable Image Registration; Structure QA; Structure propagation
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Physics in Medicine and Biology 69(2024), 175003
DOI: 10.1088/1361-6560/ad6742
Permalink: https://www.hzdr.de/publications/Publ-38159
Wearable Magnetic Field Sensor with Low Detection Limit and Wide Operation Range for Electronic Skin Applications
Li, S.; Wu, Y.; Asghar, W.; Li, F.; Zhang, Y.; He, Z.; Liu, J.; Wang, Y.; Liao, M.; Shang, J.; Ren, L.; Du, Y.; Makarov, D.; Liu, Y.; Li, R.-W.
Abstract
Flexible electronic devices extended abilities of humans to perceive their environment conveniently and comfortably. Among them, flexible magnetic field sensors are crucial to detect changes in the external magnetic field. State-of-the-art flexible magnetoelectronics do not exhibit low detection limit and large working range simultaneously, which limits their application potential. Herein, a flexible magnetic field sensor possessing a low detection limit of 22 nT and wide sensing range from 22 nT up to 400 mT is reported. With the detection range of seven orders of magnitude in magnetic field sensor constitutes at least one order of magnitude improvement over current flexible magnetic field sensor technologies. The sensor is designed as a cantilever beam structure accommodating a flexible permanent magnetic composite and an amorphous magnetic wire enabling sensitivity to low magnetic fields. To detect high fields, the anisotropy of the giant magnetoimpedance effect of amorphous magnetic wires to the magnetic field direction is explored. Benefiting from mechanical flexibility of sensor and its broad detection range, its application potential for smart wearables targeting geomagnetic navigation, touchless interactivity, rehabilitation appliances, and safety interfaces providing warnings of exposure to high magnetic fields are explored.
Keywords: flexible magnetic field sensors
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Advanced Science 11(2023)37, 2304525
DOI: 10.1002/advs.202304525
Cited 5 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38157
Curvilinear and 3D magnetism: current research and technology perspectives
Abstract
Extending 2D structures into 3D space has become a general trend in multiple disciplines, including electronics, photonics, plasmonics, superconductivity and magnetism [1,2]. This approach provides means to modify conventional or to launch novel functionalities by tailoring curvature and 3D shape of magnetic thin films and nanowires [2,3]. In this talk, we will address fundamentals of curvature-induced effects in magnetism and review the envisioned application scenarios. In particular, we will demonstrate that curvature allows tailoring fundamental anisotropic and chiral magnetic interactions [4] and enables fundamentally new non-local chiral symmetry breaking effect [5,6]. Application potential of geometrically curved magnetic architectures is currently being explored as mechanically reshapeable magnetic field sensors for automotive applications, memory, spin-wave filters, high-speed racetrack memory devices, magnetic soft robotics [7] as well as on-skin interactive electronics relying on thin films [8,9,10] as well as printed magnetic composites [11,12] with appealing self-healing performance [13].
[1] P. Gentile et al., Electronic materials with nanoscale curved geometries. Nature Electronics (Review) 5, 551 (2022).
[2] D. Makarov et al., New Dimension in Magnetism and Superconductivity: 3D and Curvilinear Nanoarchitectures. Advanced Materials (Review) 34, 2101758 (2022).
[3] D. Makarov et al., Curvilinear micromagnetism: from fundamentals to applications (Springer, Zurich, 2022).
[4] O. Volkov et al., Experimental observation of exchange-driven chiral effects in curvilinear magnetism. Physical Review Letters 123, 077201 (2019).
[5] D. D. Sheka et al., Nonlocal chiral symmetry breaking in curvilinear magnetic shells. Communications Physics 3, 128 (2020).
[6] O. M. Volkov et al., Chirality coupling in topological magnetic textures with multiple magnetochiral parameters. Nature Communications 14, 1491 (2023).
[7] M. Ha et al., Reconfigurable Magnetic Origami Actuators with On-Board Sensing for Guided Assembly. Advanced Materials 33, 2008751 (2021).
[8] G. S. Canon Bermudez et al., Magnetosensitive e-skins for interactive devices. Advanced Functional Materials (Review) 31, 2007788 (2021).
[9] J. Ge et al., A bimodal soft electronic skin for tactile and touchless interaction in real time. Nature Communications 10, 4405 (2019).
[10] G. S. Canon Bermudez et al., Electronic-skin compasses for geomagnetic field driven artificial magnetoception and interactive electronics. Nature Electronics 1, 589 (2018).
[11] M. Ha et al., Printable and Stretchable Giant Magnetoresistive Sensors for Highly Compliant and Skin-Conformal Electronics. Advanced Materials 33, 2005521 (2021).
[12] E. S. Oliveros Mata et al., Dispenser printed bismuth-based magnetic field sensors with non-saturating large magnetoresistance for touchless interactive surfaces. Adv. Mater. Technol. 7, 2200227 (2022).
[13] R. Xu et al., Self-healable printed magnetic field sensors using alternating magnetic fields. Nature Communications 13, 6587 (2022).
Keywords: curvilinear magnetism; shapeable magnetoelectronics; printed magnetoelectronics; magnetic composites
Involved research facilities
- Ion Beam Center DOI: 10.17815/jlsrf-3-159
Related publications
- DOI: 10.17815/jlsrf-3-159 is cited by this (Id 38156) publication
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Invited lecture (Conferences)
VIII Conference of the Italian Association of Magnetism (AIMAGN) - Magnet-2024, 07.-09.02.2024, Milano, Italy
Permalink: https://www.hzdr.de/publications/Publ-38156
Dimensional crossover and reentrant superconductivity in pressurized kagome metals AV3Sb5
Uykur, E.; Wenzel, M.; Faria, M.; Mavridou, K.; Luferau, A.; Ortiz, B. R.; Wilson, S.; Tsirlin, A. A.
Abstract
Non-magnetic kagome metals, AV₃Sb₅ (A: K, Rb, Cs), offer a new promising platform for engineering topological and correlated electrons [1,2]. At ambient pressure, these compounds show a competition between an exotic charge-density wave and superconductivity that are rooted in an intricate interplay of topologically non-trivial Dirac fermions, localized flat-band electrons, and van Hove singularities in the vicinity of the Fermi level. These features can be traced back to the effectively 2D band structure of vanadium kagome planes. We pioneered the broadband optical studies of AV₃Sb₅ and identified a significant damping of charge carriers [3, 4, 5], potentially related to electron-phonon coupling that has immediate implications for superconductivity.
The tunability of these properties with external means opens interesting new directions in the research of kagome metals. For example, an unusual reentrant superconductivity of AV₃Sb₅ was observed in transport measurements under pressure. In this presentation, I will summarize pressure evolution of AV₃Sb₅ revealed by single-crystal XRD, high-pressure infrared spectroscopy, and density-functional calculations. This combination of experimental and computational techniques allows a simultaneous probe of crystal and electronic structures under both hydrostatic and non-hydrostatic conditions. We show that, despite the initial similarity of AV₃Sb₅ with different alkaline metals (A = K, Rb, Cs) at ambient pressure, these compounds show a different sequence of pressure-induced structural phase transitions, which further depend on the extent of non-hydrostaticity of the pressure environment [6, 7].
Electronic structure calculated using experimental atomic positions and also probed directly by infrared spectroscopy reveals a dimensional crossover caused by the formation of interlayer Sb-Sb bonds [7]. The strongly 2D structures of AV₃Sb₅ become essentially 3D at elevated pressures. These changes lead to a reconstruction of the Fermi surface that clearly correlates with the reentrant behavior of superconductivity. We further reveal the interplay between topological and localized carriers that follow the evolution of the Fermi surface.
Our study demonstrates pressure-induced dimensional crossover as an important tool for tailoring novel electronic materials, such as kagome metals. Concurrently, we show that their high-pressure phases intimately depend on the pressure environment and its deviation from hydrostaticity.
[1] B. R. Ortiz et al., Phys. Rev. Materials 3, 094407 (2019)
[2] H. Luo et al., Nature Communications 13, 273 (2022)
[3] E. Uykur et al., Phys. Rev. B 104, 045130 (2021)
[4] E. Uykur et al., npj Quantum Materials 7, 16 (2022)
[5] M. Wenzel et al. Phys. Rev. B 105, 245123 (2022)
[6] A. A. Tsirlin et al. SciPost Physics 12, 049 (2022)
[7] A. A. Tsirlin et al. arXiv: 2209.02794
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Lecture (Conference)
The Joint 28th AIRAPT and 60th EHPRG International Conference on High Pressure Science and Technology, 23.-28.07.2023, Edinburgh, UK
Permalink: https://www.hzdr.de/publications/Publ-38155
Optical studies of magnetic kagome metals: Effect of magnetism, localized carriers and phonons
Abstract
Kagome metals attract a lot of attention as materials that combine two extreme features in their electronic structure: Massless Dirac fermions with linear band dispersion and flat bands hosting massive localized electrons. Topological nature of the former and strongly correlated nature of the latter lead to multitude of exotic phenomena, including quantum anomalous Hall effect and novel states, such as axion insulators. The electron dynamics of these systems is the key for understanding the proposed exotic phenomena including topological properties, strong electron correlations, and magnetism; along with the interplay of those.
To this end, we have employed optical spectroscopy on a series of kagome metals with different magnetic ground states. Interband and intraband transitions have been traced with broadband IR spectroscopy, where the signatures of itinerant and localized carriers have been identified. The relaxation dynamics of different contributions have also been investigated via ultrafast optical pump-probe spectroscopy. Moreover, the effect of underlying magnetic structure on the observed features and the behavior of the phonons have been discussed. In this talk, I summarize the optical fingerprints of unconventional features in magnetic kagome metals.
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Invited lecture (Conferences)
Low-Energy Electrodynamics in Solids 2023, 25.-30.06.2023, Sankt Pölten, Austria
Permalink: https://www.hzdr.de/publications/Publ-38154
Broadband optical investigations of the CDW state in kagome metals AV3Sb5 (A = K, Rb, Cs)
Uykur, E.; Wenzel, M.; Ortiz, B. R.; Wilson, S. D.; Winnerl, S.; Dressel, M.; Tsirlin, A. A.
Abstract
We present a broadband optical study of non-magnetic kagome metals AV3Sb5 (A = K, Rb, Cs) down to 10 K. Different contributions to the optical spectra have been discussed and compared with the DFT calculations in normal and charge density wave (CDW) states. Spectra reflect the response of the 2D Dirac fermions and are frequency-independent in a broad energy range. Low energies are governed by the itinerant and localized charge carriers that show a spectral weight redistribution below the CDW transition. Our results show that the CDW gaps evolve systematically between the siblings (K
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Lecture (Conference)
DPG-Frühjahrstagung der Sektion Kondensierte Materie (SKM), 26.-31.03.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38153
Optimisation of synthesis procedures and structural investigation of monazite-cheralite solid solutions
Lender, T.; Braga Ferreira Dos Santos, L.; Gericke, R.; Huittinen, N. M.; Peters, L.
Abstract
The monazite-cheralite solid solutions LnPO4-Ca0.5Th0.5PO4 with Ln = La, Gd were prepared via a co-precipitation route, showcasing an optimised, scalable synthesis procedure for a possible waste form accommodating high level liquid waste streams. A distortion of the cheralite structure with respect to the monazite structure was observed throughout both solid solutions as evidenced by a deviation of the lattice parameters from the linear behaviour known from other monazite solid solutions. Using a high temperature flux method, cheralite single crystals were grown for the first time for in-depth structural investigations. Both thorium and calcium were found to deviate from the central position of the LnO9 polyhedron, supporting previous neutron diffraction investigations of identical cheralite samples.
Keywords: X-ray diffraction; solid solution; cheralite; lanthanides; actinides; single crystal flux growth
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MRS Advances 9(2024), 433-438
DOI: 10.1557/s43580-024-00792-6
Cited 1 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-38152
Thermal sensing interface for bioassay monitoring in well plates
Nieder, D.; Janićijević, Ž.; Baraban, L.
Abstract
Poster on a single-element thermal sensor in a 3D printed well format for the monitoring of biological assays. The modified Transient Plane Source sensing technique is used for simultaneous measurement of the thermal effusivity of various samples and as a heating element.
Keywords: Thermal sensor; Well plate; Biosensor
Involved research facilities
- ZRT
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Poster
HZDR DocSeminar 2023, 17.-19.10.2023, Schilbach, Germany
Permalink: https://www.hzdr.de/publications/Publ-38151
Fermiology of Strongly Correlated Metals
Wosnitza, J.
Abstract
ein Abstract hat nicht vorgelegen
Involved research facilities
- High Magnetic Field Laboratory (HLD)
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Invited lecture (Conferences)
Workshop on "Electron Correlations: From Basic Properties to Applications, 30.11.2023, Dresden, Deutschland
Permalink: https://www.hzdr.de/publications/Publ-38150
Euler-Euler simulation of a bubble column flow up to high gas fraction
Abstract
This study investigates homogeneous flow in a bubble column up to 50% gas-holdup. For low to medium gas-holdup, the good performance of an established baseline model is confirmed. In this range, the mixture pressure gradient is decisive in determining the relative velocity, resulting in good predictions without considering swarm effects. However, beyond a gas-holdup of ~20%, a swarm corrector to the drag-force becomes necessary, for which several proposals from the literature are evaluated. In addition, the lift-force influences the shape of the gas-fraction profile depending on the bubble size, which has a significant impact on the liquid flow inside the column. For wall-peaked profiles, the liquid flow remains moderate, while center-peaked profiles strongly boost the liquid velocity. Finally, several mechanisms proposed in the literature for inducing unstable flow based on the lift-force, bubble-induced turbulence or flooding are investigated. Of these only the first gave qualitative agreement with the observed gas-holdup.
Keywords: dispersed gas-liquid flow; homogeneous and heterogeneous bubble-column flow; Euler-Euler two-fluid model; swarm effect; lift force; CFD simulation
Involved research facilities
- Data Center
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International Journal of Multiphase Flow 181(2024), 104969
DOI: 10.1016/j.ijmultiphaseflow.2024.104969
Permalink: https://www.hzdr.de/publications/Publ-38149
Eulerian simulation of a bubble column up to high gas fractions
Abstract
This study investigates homogeneous flow in a bubble column up to a 50% gas holdup. For low to medium gas holdup the good performance of an established baseline model is confirmed. In this range, the mixture pressure gradient is decisive in determining the relative velocity, resulting in good predictions without considering the swarm effect. However, beyond a gas holdup of ~20%, a swarm corrector becomes necessary, for which several proposals from the literature are evaluated. In addition, the lift force influences the gas fraction profile depending on the bubble size. The resulting profile shape has a significant impact on the liquid flow inside the column. If the profile is wall-peaked, the liquid flow remains moderate, while a center-peaked profile strongly boosts the liquid velocity.
Keywords: dispersed gas-liquid flow; homogeneous bubble-column flow; Euler-Euler two-fluid model; swarm effect; lift force; CFD simulation
Involved research facilities
- Data Center
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Lecture (Conference)
The 11th International Flotation Conference (Flotation '23), 05.-09.11.2023, Kapstadt, Südafrika
Permalink: https://www.hzdr.de/publications/Publ-38148
Perfusion and Time of Exchange Measurements Using BBB-ASL in Gliomas: The Initial Experience
Turhan, G.; Çetin, A. İ.; Mahroo, A.; Padrela, B.; Konstandin, S.; Hoinkiss, D. C.; Breutigam, N. J.; Eickel, K.; Petr, J.; Mutsaerts, H.; Danyeli, A. E.; Ozduman, K.; Guenther, M.; Dincer, A.; Ozturk-Isik, E.
Abstract
Subtle changes in BBB integrity might be missed by contrast-enhanced T1-weighted MRI. Blood-brain barrier arterial spin labeling (BBB-ASL) is a new technique to assess BBB disruptions. In this work, we measured the cerebral blood flow (CBF) and exchange time (Tex) values of the tumor, normal-appearing white matter, and normal-appearing gray matter regions in gliomas using BBB-ASL technique. Our results indicated higher CBF and leakier BBB in contrast-enhanced regions of gliomas than in the normal-appearing GM.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 1757 -
Poster
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
Permalink: https://www.hzdr.de/publications/Publ-38147
DEveloping Blood-Brain barrier arterial spin labeling as a non-Invasive Early biomarker (DEBBIE)
Padrela, B.; Tee, M.; Sneve, M.; Mahroo, A.; Geier, O.; Thomas, D.; Morgan, C.; Moyaert, P.; Ozturk, E.; Nordhøy, W.; Pålhaugen, L.; Linn, J.; Selnes, P.; Eickel, K.; Konstandin, S.; Kuijer, J.; Hoinkiss, D.; Breutigam, N.; Buck, M.; Achten, R.; Barkhof, F.; Hilal, S.; Fladby, T.; Anazodo, U.; Petr, J.; Mutsaerts, H. J. M. M.; Günther, M.
Abstract
One of the earliest signs of Alzheimer’s disease (AD) is the loss of blood-brain barrier (BBB) integrity. Arterial spin labeling (ASL) MRI is a non-invasive way to measure perfusion and several other hemodynamic and physiological parameters, including vascular permeability. The DEveloping BBB-ASL as non-Invasive Early biomarker (DEBBIE) consortium aims to develop and integrate innovative techniques to allow robust BBB permeability assessments by ASL to develop a sensitive, non-invasive, and early biomarker for AD and related dementias. This work summarizes our planned efforts to develop and establish an MRI-based BBB permeability biomarker.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 0367 -
Lecture (Conference)
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
Permalink: https://www.hzdr.de/publications/Publ-38146
Blood-brain barrier permeability changes over the lifespan
Padrela, B.; Sneve, M. H.; Zelhorst, S.; Tee, M.; Mahroo, A.; Kuijer, J.; Walhovd, K.; Konstandin, S.; Eickel, K.; Barkhof, F.; Hilal, S.; Günther, M.; Mutsaerts, H. J. M. M.; Petr, J.
Abstract
Blood-brain-barrier (BBB) dysfunction is a hallmark of aging-related disorders, including cerebral small vessel disease and Alzheimer’s disease. An emerging biomarker of BBB dysfunction is time of exchange (Tex) of water across the BBB as measured by multi-echo arterial spin labeling MRI. We evaluated Tex across the age spectrum in 40 adults from two cohorts of healthy controls, and demonstrated that Tex is higher in gray than in white matter, higher in females than in males, and that Tex decreases with age. These findings suggest that BBB permeability changes over the lifespan can be investigated using arterial spin labeling approaches.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 1919 -
Poster
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
Permalink: https://www.hzdr.de/publications/Publ-38145
ASL spatial coefficient of variance predicts increased white matter hyperintensities volume over time in cognitively unimpaired subjects
Padrela, B.; Collij, L. E.; Lorenzini, L.; Ingala, S.; Sudre, C.; Visser, P. J.; Den Braber, A.; Barkhof, F.; Petr, J.; Mutsaerts, H. J. M. M.
Abstract
Arterial transit artifacts (ATAs) in arterial spin labeling (ASL) images are common in populations with prolonged arterial transit time (ATT) and may be associated with vascular insufficiency. The spatial coefficient of variance (sCoV) of ASL images can quantify the presence of these artifacts. Vascular insufficiency could contribute to the development of white matter hyperintensities (WMH), a common marker of cerebral small vessel disease. We demonstrated that baseline sCoV of CBF is associated with WMH at baseline and predicts WMH volume change, in a cognitively unimpaired population of 88 subjects.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 0580 -
Poster
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
Permalink: https://www.hzdr.de/publications/Publ-38144
Classification of IDH mutation with Arterial Spin Labeling and Dynamic Susceptibility Contrast MRI in adult gliomas
Prysiazhniuk, Y.; Server, A.; Bech-Aase, Ø.; Helseth, E.; Kala, D.; Eijgelaar, R. S.; Fuster-García, E.; Brandal, P.; Bjørnerud, A.; Otáhal, J.; Petr, J.; Nordhøy, W.
Abstract
IDH genotype status is an important marker in glioma diagnostics. Given that IDH mutation affects the tumor vascularization pattern, perfusion imaging has the potential to become a non-invasive tumor histopathology assessor. In this study, two methods of perfusion MRI – Dynamic Susceptibility Contrast (DSC) and Arterial Spin Labeling (ASL) – were compared in their ability to assess IDH mutation status. DSC- and ASL-derived perfusion maps correlated significantly and were feasible parameters in the IDH classification task. Mean tumor CBF quantified with ASL had the highest AUC score, sensitivity, and specificity, supporting the feasibility of using ASL in clinical glioma diagnostics.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 1747 -
Poster
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
Permalink: https://www.hzdr.de/publications/Publ-38143
Cardiovascular and cerebrovascular health in 70-year-olds: a population-based ASL study
Dijsselhof, M. B. J.; James, S.-N.; Lorenzini, L.; Collij, L.; Thomas, D. L.; Scott, C.; Manning, E.; Józsa, T. I.; Cash, D.; Study, I.; Sudre, C.; Hughes, A. D.; Richards, M.; Barkhof, F.; Schott, J.; Petr, J.; Mutsaerts, H. J. M. M.
Abstract
While mid-life cardiovascular pathology may lead to late-life cognitive decline, our understanding of the role of cerebrovascular health as an intermediate biomarker is limited. We explored the association between cardiovascular health biomarkers and cross-sectional and longitudinal cerebrovascular health assessed by ASL MRI in Insight46, a well-characterised cognitively normal population-based sample.
We found several cross-sectional and longitudinal associations between blood pressure and CBF. These findings suggest that the effects of BP on cerebrovascular health can be imaged with ASL perfusion MRI, possibly offering opportunities to prevent or intervene before cognitive decline sets in.
Involved research facilities
- PET-Center
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Contribution to proceedings
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada
ISMRM '23: Proceedings of the ISMRM 31th Annual Meeting & Exhibition, 1304 -
Lecture (Conference)
2023 ISMRM & ISMRT Annual Meeting & Exhibition, 03.06.2023, Toronto, Canada -
Contribution to proceedings
OHBM '23: Proceedings of the Organization for Human Brain Mapping Annual Meeting, 22.07.2023, Montreal, Canada -
Poster
OHBM '23: Proceedings of the Organization for Human Brain Mapping Annual Meeting, 22.07.2023, Montreal, Canada
Permalink: https://www.hzdr.de/publications/Publ-38142
Data publication: Geochemistry and fluid inclusion analyses of the Sadisdorf Li-Sn-(W-Cu) magmatic-hydrothermal greisen and vein system, eastern Erzgebirge, Germany
Leopardi, D.; Gutzmer, J.; Lehmann, B.; Burisch-Hassel, M.
Abstract
This data repository contains the sample locations and descriptions as well as the result for whole-rock, microthermometric and Raman analyses for the publication: “ The spatial and temporal evolution of the Sadisdorf Li-Sn-(W-Cu) magmatic-hydrothermal greisen and vein system, eastern Erzgebirge, Germany”.
Keywords: Fluid inclusions; Sn-W; Lithium
Related publications
- DOI: 10.5382/econgeo.5077 references this (Id 38141) publication
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The spatial and temporal evolution of the Sadisdorf Li-Sn-(W-Cu) …
ROBIS: 38050 has used this (Id 38141) publication of HZDR-primary research data
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Reseach data in the HZDR data repository RODARE
Publication date: 2023-12-14 Open access
DOI: 10.14278/rodare.2619
Versions: 10.14278/rodare.2620
License: CC-BY-4.0
Downloads
Permalink: https://www.hzdr.de/publications/Publ-38141
Data-driven Simulation of Target Normal Sheath Acceleration by Fourier Neural Operator
Rustamov, J.; Stiller, P.; Miethlinger, T.; Kluge, T.; Hoffmann, N.; Bussmann, M.; Kelling, J.
Abstract
Particle-in-Cell simulations are a ubiquitous tool for linking theory and experimental data in plasma physics rendering the comprehension of non-linear processes such as Laser Plasma Acceleration (LPA) feasible. These numerical codes can be considered as state-of-the-art approach for studying the underlying physical processes in high temporal and spatial resolution. The analysis of experiments is performed by optimising simulation parameters so that the simulated system is able to explain experimental results. However, a high spatio-temporal resolution comes at the cost of elevated simulation times which makes the inversion nearly impossible. We tackle that challenge by introducing and studying a reduced order model based on Fourier neural operator that is evolving the ion density function of Laser-driven Ion acceleration via 1D Target Normal Sheath acceleration (TNSA). The ion density function can be dynamically generated over time with respect to the thickness of the target. We show that this approach yields a significant speed-up compared to numerical code Smilei while retaining physical properties to a certain degree promising applicability for inversion of experimental data by simulation-based inference.
Involved research facilities
- Data Center
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Poster
Matter and Technologies, 09.-11.10.2023, Karlsruhe, Deutschland -
Poster
DPG Spring Meeting "Berlin 2024", 21.03.2024, Berlin, Germany
Permalink: https://www.hzdr.de/publications/Publ-38140
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