Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Zirconia (ZrO2) doped with lanthanides, such as cerium (Ce), has been extensively studied for a multitude of tailored applications. The ZrxCe1-xO2 solid solutions can occur in three stable structures: monoclinic (m), tetragonal (t), and cubic (c), but also in several metastable ones (t′, t′′, κ, and t*)1. The phase transformation depends on the dopant concentration and the synthesis conditions, such as sintering temperature or cooling rate. In this study, to understand the behavior of cerium in the zirconia structure, 5 solid solution compositions with Ce4⁺ concentrations of 14, 18, 22, 26, and 30 mol % were synthesized through co-precipitation route. As an additional structural probe, a figurative amount of europium was added to the samples to enable luminescence spectroscopic analyses (TRLFS). In addition to these TRLFS investigations, the phase compositions were evaluated by Raman spectroscopy and synchrotron powder X-ray diffraction (PXRD). The PXRD results show that the diffraction peak around 14.9o can be attributed to the tetragonal phase, and the amount of this phase increases with increasing Ce concentration. Due to the substitution of Zr4+ by the larger Ce4+cation, the diffraction peaks are shifted to lower 2, here from 14.92 to 14.87o2. The t’ and c phases are not easy to distinguish. Owing to the high-resolution PXRD data, however, the diffraction peak around 16.91o could be attributed to the t’ phase and the peak at 16.77o to the cubic one. Both peaks could be identified in the compounds with more than 22 mol % of Ce3. At this concentration, no more monoclinic phase could be detected. TRLFS measurements of the Eu environment, corroborated the presence of the above mentioned phases, going from the dominant monoclinic to tetragonal metastable and cubic phases with increasing Ce substitution4. Combining the PXRD, TRLFS, and Raman data, no solid phase separation (CeO2+ZrO2) was detected.

Actinide research is currently experiencing a renaissance in the fields of material science,
nanotechnology, medicine and environmental science. It is now possible to study the
chemistry and physics of the actinide elements (all radioactive) using state-of-the-art
non-destructive techniques at synchrotrons which have not been available before. The
beamlines and instruments dedicated to actinide research have made various spectro-
scopic and scattering methods accessible to scientists worldwide. The new synchrotron
sources at the large-scale facilities offer more advanced possibilities for the development
of new methodologies in actinide science in the future. Theoretical studies of actinides
are followed by unique experimental methods and novel experimental data.

Over 60 years of nuclear activity have resulted in a global legacy of contaminated land and radioactive waste. Uranium (U) is a significant component of this legacy and is present in radioactive wastes and at many contaminated sites. U-incorporated iron (oxyhydr)oxides may provide a long-term barrier to U migration in the environment. However, reductive dissolution of iron (oxyhydr)oxides can occur on reaction with aqueous sulfide (sulfidation), a common environmental species, due to the microbial reduction of sulfate. In this work, U(VI)-goethite was initially reacted with aqueous sulfide, followed by a reoxidation reaction, to further understand the long-term fate of U species under fluctuating environmental conditions. Over the first day of sulfidation, a transient release of aqueous U was observed, likely due to intermediate uranyl(VI)-persulfide species. Despite this, overall U was retained in the solid phase, with the formation of nanocrystalline U(IV)O2 in the sulfidized system along with a persistent U(V) component. On reoxidation, U was associated with an iron (oxyhydr)oxide phase either as an adsorbed uranyl (approximately 65%) or an incorporated U (35%) species. These findings support the overarching concept of iron (oxyhydr)oxides acting as a barrier to U migration in the environment, even under fluctuating redox conditions.

Uranium (U) is a ubiquitous element in the Earth’s crust, having a concentration of about 2 ppm.
Soluble hexavalent uranium (U(VI)) is reduced and immobilized in anoxic environments. The
underlying reduction mechanism is unknown but is likely of critical importance to explain variability in
U biogeochemical behaviors. In this study, we focused on the mechanism of reduction of U(VI) by the
mixed-valence iron oxide magnetite

Immunotherapy using CAR-T cells is a new paradigm technology for cancer treatment. To avoid severe side effects and tumor escape variants observed for conventional CAR-T cells approach, adaptor CAR technologies are under development, where intermediate target modules redirect immune cells against cancer cells. In this work, silicon nanowire field effect transistors are used to assist in the development of target modules for an optimized CAR-T cell operation. Focusing on a library of seven variants of E5B9 peptide that is used as CAR peptide epitope, we performed multiplexed binding tests in serum using nanosensor chips. Peptides have been immobilized onto the sensor to compare the signals of transistor upon titration with anti-E5B9 antibodies. Correlation analysis of binding affinities and sensitivities enabled a selection of best candidates for the interaction between CAR and target modules. Finally, cytotoxic functionality of CAR-T cells in combination with the selected target modules were successfully proven. Our results open the perspective for the nanobiosensorics to go beyond the early diagnostics in the field of clinical cancer research, and paves the way towards personalization and efficient monitoring of the immunotherapeutic treatment, where the quantitative analysis with the standard techniques is not an option.

Due to its unique ability to reduce carbon dioxide (CO₂) into CO or formate at high versus low overpotentials, respectively, palladium is a promising catalyst for the electrochemical CO₂-reduction reaction (CO₂RR). Further improvements aim at increasing its activity and selectivity toward either of these value-added species, while reducing the amount of hydrogen produced as a side product. With this motivation, in this work, we synthesized a range of unsupported, bimetallic PdPt aerogels and pure Pt or Pd aerogels and extensively characterized them using various microscopic and spectroscopic techniques. These revealed that the aerogels’ porous web consists of homogenous alloys of Pt and Pd, with palladium and platinum being present on their surface for all compositions. The subsequent determination of these aeorgels’ CO₂RR performance unveiled that the high activity of these Pt surface atoms toward hydrogen evolution causes all PdPt alloys to favor this reaction over CO₂ reduction. In the case of the pure Pd aerogel, although, its unsupported nature leads to a suppression of H₂ evolution and a concomitant increase in the selectivity toward CO when compared to a commercial, carbon-supported Pd-nanoparticle catalyst.

We present results on the synchronization of the helicity in a liquid-metal Rayleigh-Bénard (RB) experiment under the influence of a tide-like electromagnetic forcing with azimuthal wavenumber m = 2. We show that for a critical forcing strength the typical Large Scale Circulation (LSC) in the cylindrical vessel of aspect ratio unity is entrained by the period of the tide-like forcing, leading to synchronized helicity oscillations with opposite signs in two half-spaces. The obtained experimental results are consistent with and supported by numerical simulations. A similar entrainment mechanism for the helicity in the solar tachocline may be responsible for the astonishing synchronization of the solar dynamo by the 11.07-year triple synodic alignment cycle of the tidally dominant planets Venus, Earth and Jupiter.

1 Introduction
Bentonite is considered as buffer and sealing material in a multi-barrier system for a deep geologic repositories (DGR) of nuclear waste and spent fuel [1]. Another part of the engineered barrier system is the containment of the radioactive waste. Cast iron is often taking into account for the construction of the containers as a candidate material [2]. But the cast iron components are fairly unstable, can corrode to insoluble corrosion products and react with the bentonite buffer matrix. Anaerobic corrosion together with microbially influenced corrosion are dominant forms of corrosion in the a DGR and the interactions at the metal/bentonite interface determines the performance of bentonite-based radioactive waste barriers [3]. The aim of the current study was to characterize the surface damage associated with corrosion of the cast iron and to compare the potential of the indigenous microorganisms present in different bentonites to influence the corrosion of cast iron.

2 Results
Three types of bentonite (B25, Calcigel, MX-80) were chosen for mesocosm-experiment setup as described in [4]. All three bentonites have different smectite content and an indigenous microbial community. The mesocosms with cast iron coupons, artificial Opalinus clay porewater and bentonite were incubated in N2/CO2 atmosphere for 271 days at 30 °C. Some of the mesocosms were supplemented with 5 mM sodium lactate and hydrogen (to a 0.5 bar of total pressure) to stimulate microbial activity. After the incubation period the content of the mesocosms was divided and subjected to different analysis, including geochemical analysis (as e.g. ICP-MS, ion and high-performance liquid chromatography), DNA isolation and amplification of the intergenic spacer to determine the microbial community structure, SEM-EDX and RAMAN spectroscopy to characterize the surface damage of the cast iron coupons.
The black precipitates were visible in the mesocosms containing Calcigel with lactate as substrate and for all the substrate-containing samples with MX-80. The obtained geochemical data confirmed the differences in the different microcosms by demonstrating unequal levels of sulphate and lactate consumption. Moreover, surface analysis of the cast iron coupons showed that corrosion rate and metabolite accumulation are also dependent on the bentonite type. In addition different microbial community structure was observered by intergenic spacer analysis (RISA) depending on the conditions applied and used bentonite. Therefore, the used bentonites varied in respect to reactivity and microbial activity.
Overall, the results show the importance of selection of suitable bentonite for DGR to adjust microbial implications and possibly faster corrosion rate of the metal containers.
We acknowledge funding by the BMBF (Grant 02NUK053B) and HGF (Grant SO-093).
References
[1] P. Sellin and etc., The Use of Clay as an Engineered Barrier in Radioactive-Waste Management – A Review, Clays and Clay Minerals 61(6), pp. 477-498 (2014).
[2] F. King. Container Materials for the Storage and Disposal of Nuclear Waste, Corrosion 69(10), pp. 986-1011 (2013).
[3] S. Kaufhold and etc. About the Corrosion Mechanism of Metal Iron in Contact with Bentonite, ACS Earth Space Chem. 4, 5, pp. 711–721 (2020).
[4] N. Matschiavelli and etc., The Year-Long Development of Microorganisms in Uncompacted Bavarian Bentonite Slurries at 30 and 60 °C, Environ. Sci. Technol., 53, 17, 10514–10524 (2019)

In this work a 1D finite volume based model using coupled meshes is introduced to capture potential and species distribution throughout the discharge process in a lithium–bismuth liquid metal battery while neglecting hydrodynamic effects, focusing on the electrochemical properties of the cell and the mass transport
in electrolyte and cathode. Interface reactions in the electrical double layer are considered through the introduction of a discrete jump of the potential modelled as periodic boundary condition to resolve interfacial discontinuities in the cell potential. A balanced-force like approach is implemented to ensure consistent calculation at the interface level. It is found that mass transport and concentration gradients have a significant effect on the cell overpotentials and thus on cell performance and cell voltage. By quantifying overvoltages in the Li||Bi cell with a mixed cation electrolyte, it is possible to show that diffusion and migration current density could have counteractive effects on the cell voltage. Furthermore, the simulated limiting current density is observed to be much lower than experimentally measured, which can be attributed to convective effects in the electrolyte that need to be addressed in future simulations.
The solver is based on the open source library OpenFOAM and thoroughly verified against the equivalent system COMSOL multiphysics and further validated with experimental results.

Increased dietary phosphate intake has been associated with severity of coronary artery disease, increased carotid intima–media thickness, left ventricular hypertrophy (LVH), and increased cardiovascular mortality and morbidity in individuals with nor-mal renal function as well as in patients suffering from chronic kidney disease. How-ever, the underlying mechanisms are still unclear. To elucidate further the cardiovas-cular sequelae of long-term elevated phosphate intake we maintained male C57BL/6 mice on a calcium, phosphate, and lactose‐enriched diet (CPD, 2% Ca, 1.25% P, 20% lactose) after weaning for 14 months and compared them with age-matched male mice fed a normal mouse diet (ND, 1.0% Ca, 0.7% P). Notably, the CPD has a balanced cal-cium/phosphate ratio, allowing to investigate the effects of elevated dietary phosphate intake largely independent of changes in parathyroid hormone (PTH). In agreement with the rationale of this experiment, mice maintained on CPD for 14 months were characterized by unchanged serum PTH but showed elevated concentrations of circu-lating intact fibroblast growth factor-23 (FGF23) compared with mice on ND. Cardio-vascular phenotyping did not provide evidence for LVH, as evidenced by unchanged LV chamber size, normal cardiomyocyte area, lack of fibrosis, and unchanged molecu-lar markers of hypertrophy (Bnp) between the two groups. However, intra-arterial catheterization revealed increases in systolic pressure, mean arterial pressure, and pulse pressure in mice fed the CPD. Interestingly, chronically elevated dietary phos-phate intake stimulated the renin-angiotensin-aldosterone system (RAAS) as evi-denced by increased urinary aldosterone in animals fed the CPD, relative to ND con-trols. Furthermore, the catecholamines epinephrine, norepinephrine, and dopamine as well as the catecholamine metabolites metanephrine. normetanephrine and methoxy-tyramine as measured by mass spectrometry were elevated in the urine of mice on CPD, relative to mice on ND. These changes were partially reversed by switching 14-month-old mice on CPD back to ND for 2 weeks. In conclusion, our data suggest that excess dietary phosphate induces a rise in blood pressure independent of second-ary hyperparathyroidism, and that this effect may be mediated through activation of the RAAS and stimulation of the sympathetic tone.

Long-living radiotoxic isotopes present in spent nuclear fuel (SNF) requires procedures of complete immobilization of these species. Incorporation of the corresponding elements on atomic level into robust host crystalline matrices is one way to secure SNF during long-term underground storage. Derivatives of zirconia, ZrO2, are promising materials for these applications since these phases are known to remain structurally stable in geological cycles of up to 109 years [1]. The candidate host matrix must provide a sufficient solubility limit for radiotoxic elements, which is studied initially. Afterwards, structural stability of these phases against irradiation and leaching are established in order to asses possible discharge of the incorporated radioactive elements over a long-time scale. In this work we studied systematically structural behaviour of ZrO2-based materials incorporated with Th4+ and Ce4+ under extreme conditions of temperature (T) and pressure (P) in order to simulate experimentally possible phase evolution in conditions of underground storage.
In situ synchrotron radiation powder diffraction experiments under ambient and extreme conditions were performed at the HZDR ROBL BM20 beamline at ESRF, Grenoble, France [2]. It was found that cubic YSZ phases could dissolve 20% more of Th atoms compared to their tetragonal analogues. In situ T-dependent diffraction studies on radionuclide surrogate tetragonal and cubic Ce-YSZ series in a RT-1150 K range revealed excellent phase stabilities. No discharge of guest Ce4+ ions was observed. Nevertheless, application of external pressure on tetragonal Ce-YSZ phase induced transition towards a higher cubic symmetry around the P ~ 8.5 GPa. Remarkably, occupancy of Ce4+ remains stable throughout the transition. This together with T-dependent data indicates excellent affinity of guest Ce atoms with the YSZ structures. Thus, we suggest in situ studies under extreme conditions as a part of standard protocol to validate phases of interest as host matrixes for long-term underground storage of SNF.

References
[1] L. M. Heaman, A. N. LeCheminant, Chem. Geol. 110, 95 (1993). [2] A. C. Scheinost et al., J. Synchr. Rad. 28, 333 (2021).

Majority of man-made radiotoxic elements originate from spent nuclear fuel (SNF). It is composed essentially of uranium and plutonium and some minor actinides (An) like 237Np, 241Am/243Am, and 244Cm. Half-life of these elements can range from few decades up to millions of years (ca. 2.1 million years for 237Np [1]). Therefore, safe disposal of SNF requires matrix materials with strong resistance against corrosion and dissolution over a period of 106 years. Derivatives of zirconium-based ceramics, in particular zirconia, ZrO2, are promising materials for these applications since these phases are known to remain stable in geological cycles of up to 109 years [2]. Here scientific and technological goals are to obtain zirconium-based ceramic materials containing maximum possible tetravalent actinides (An) without Zr/An phase separation. In addition, structural stability of these phases under various external parameters, e.g. temperature (T), pressure (P), irradiation and leaching resistance is essential in order to exclude possible discharge of the incorporated radioactive elements over a long-time scale.
Two series of samples have been synthesized for current study: (I) Th-doped Y-stabilized ZrO2 (YSZ) and (II) Ce-doped YSZ phases, both of tetragonal and cubic symmetries. The series (I) was studied in order to determine maximum possible intake of Th4+ ions into the tetragonal and cubic YSZ matrices. The series II used Ce4+ species as surrogate ions for An4+ for studies under extreme conditions of T and P. Synchrotron radiation powder diffraction experiments under ambient and extreme conditions were performed at the ROBL BM20 beamline at ESRF [3]. Relevant technical details will be presented.
For the tetragonal YSZ phases maximum possible Th intake on the Zr/Y metal site reached ca. 10.3 at.%. Cubic phases could dissolve up to ca. 12.3 at.% Th under non-equilibrium conditions. Larger Th-Zr/Y solubility range for cubic phases was found to be symmetry related. Specifically, introduction of Th into tetragonal YSZ induces flattening of the Zr/YO8 polyhedra with concomitant decrease in tetragonality. This results in better accommodation of larger Th atoms via structural stabilization of longer bonding distances.
To simulate phase stability under conditions of underground nuclear repositories, Ce-based analogues were subjected to in situ studies under elevated temperatures and pressures. T-dependent diffraction studies on tetragonal and cubic Ce-YSZ series in a RT-1150 K range revealed excellent structural stability for all the studied compounds. In particular, occupancy of guest Ce4+ atoms as a function of temperature does not decrease in these systems. However, application of external pressure on tetragonal Ce-YSZ phase induced a structural transformation to a higher cubic symmetry around the P ~ 8.5 GPa. Remarkably, occupancy of Ce4+ remains stable throughout the transition. This together with T-dependent data indicates excellent affinity of guest Ce atoms with the YSZ structures. The parent YSZ phases are, therefore, promising candidates as host matrices for radiotoxic tetravalent elements like U, Th or Pu for a long-term underground storage.

References
[1] R. C. Ewing, W. J. Weber, J. Lian, J. Appl. Phys. 95, 5949 (2004).
[2] L. M. Heaman, A. N. LeCheminant, Chem. Geol. 110, 95 (1993).
[3] A. C. Scheinost et al., J. Synchr. Rad. 28, 333 (2021).

Ultrafast electron beam X-ray computed tomography [4] (UFXCT) is a non-invasive imaging technique based on scanning an electron beam on a tungsten target. This way, a moving X-ray source is generated without mechanically moving parts allowing for very high imaging rates up to 8000 fps.
This technique is used, e.g., for the investigation of multiphase flows, such as bubbly flow in industrial bubble column reactors. The goal of the ROOF experiment is to investigate the hydrodynamics of such a bubbly flow by apply UFXCT for scanning and tracking of objects alongside a vertical axis in real time based on the acquired cross-sectional images. To accomplish the tracking, software is needed to recognize objects in the reconstructed images, as a human would not fulfill realtime constraints. The current CPU-based implementation is the slowest step in the current workflow, thus, the goal of this work is to design a faster algorithm. In this work, the approach used by the RISA [5] (Realtime Image Stream Algorithms) software to realize the tracking of objects is presented and improved by using the GPU to recognize the objects.

INTRODUCTION

Bentonite is a potential barrier material in deep geological repositories (DGR) for nuclear waste and spent fuel [1] and it is critical to maintain its functionality for long periods of time. Bacteria, that can originate from the bentonite itself, can affect important properties of the engineered barrier system, including bentonite’s swelling capability and integrity of the container material [2]. Cast iron is often considered as a suitable material for constructing the containers for the radioactive waste storage [3]. But the container material could be unstable and can corrode to insoluble corrosion products, which react with the bentonite barrier. In a DGR, anaerobic corrosion and microbially influenced corrosion are dominant forms of corrosion and the interactions at the metal/bentonite interface determine the long-term performance of bentonite-based radioactive waste barriers [4].

DESCRIPTION OF THE WORK

Microcosm-type setup described in [5] was used for the current study. Three types of bentonite with different indigenous microorganisms were chosen for the setup: B25, Calcigel, MX-80. Incubation of the microcosms, containing GGG40 cast iron coupons, synthetic Opalinus Clay porewater (OPA) and bentonite, was performed in N2/CO2 atmosphere at 30 °C. Some of the microcosms were supplemented with 5 mM sodium lactate or 0.5 bar of hydrogen to stimulate microbial activity. After a 271-day incubation period, the microcosms were investigated by various geochemical analyses (as e.g. ICP-MS, ion and high-performance liquid chromatography), DNA isolation and amplification of the ribosomal RNA (rRNA) intergenic spacer (RISA) for microbial community analysis, SEM-EDX and RAMAN spectroscopy to characterize the surface structure of the cast iron coupons.
In addition, a similar 3-component experiment was set up with Calcigel including 4 time points to study in more detail the microbial-induced process of cast iron corrosion in Calcigel-microcosms.

RESULTS AND DISCUSSION

After 271 days of incubation under anaerobic conditions at 30 °C, the presence of black precipitants in microcosms containing Calcigel and sodium lactate, and all substrate-containing MX-80 samples became apparent. Geochemical investigation of the respective samples showed a decrease in sulphate concentration which was dominant in microcosms containing MX-80.
Surface analysis with SEM-EDX showed severe damage for all the samples, except B25 without substrates. Two types of crystalline structures were found: iron and/or calcium carbonates and iron sulphide. The presence of the latter could be an indication of the activity of sulphate-reducing bacteria.
Different microbial community structures were observed by RISA analysis depending on the used bentonite and the applied conditions.
Overall, the results show that the reactivity at the bentonite/metal interface and the microbial activity are bentonite-type dependent and the selection of the bentonite for the DGR is highly important for preventing possible microbial implications that could lead to a faster deterioration of the metal container.

ACKNOWLEDGEMENT

Funding was provided by the German Federal Ministry of Education and Research (BMBF, Grant 02NUK053) and the Helmholtz Association (Grant SO-093).

REFERENCES

1. P. Sellin et al., “The Use of Clay as an Engineered Barrier in Radioactive-Waste Management – A Review” Clays and Clay Minerals, 61(6), pp. 477-498 (2014).
2. F. King, “Container Materials for the Storage and Disposal of Nuclear Waste” Corrosion, 69(10), pp. 986-1011 (2013).
3. F. King et al., “Nature of the near-field environment in a deep geological repository and the implications for the
corrosion behaviour of the container” Corrosion Engineering, Science and Technology, 52, 1, pp. 25-30 (2017).
4. S. Kaufhold et al., “About the Corrosion Mechanism of Metal Iron in Contact with Bentonite” ACS Earth Space Chem., 4, 5, pp. 711–721 (2020).
5. N. Matschiavelli et al., “The Year-Long Development of Microorganisms in Uncompacted Bavarian Bentonite Slurries at 30 and 60 °C” Environ. Sci. Technol., 53, 17, 10514–10524 (2019)

Introduction
The cannabinoid receptor 2 (CB2R) is involved in inflammatory processes [1], whereby an increased expression correlates with malignancy in various cancer types like human epidermal growth receptor 2 positive (HER2+) or triple negative breast cancer (TNBC) [2]. Hence, the CB2R is suggested as a pharmacological target and prognostic marker for stratification and staging of patients [3].
In the present in vitro studies, we investigated the expression of the CB2R in HER2+ and TNBC models, as well as the potential of our novel radioligand [18F]JHU94620-d8 to assess the CB2R availability in TNBC models.

Methods
The colocalisation of CB2R with Iba1 (macrophages) and CD31 (blood vessels) in cryosections of mouse TNBC 4T1 tumours heterotopically implanted in both NMRI-nude and Balb/c mice was investigated by immunofluorescence staining (IF). The CB2R expression in 4T1, the human HER2+ cell lines HCC1954 (HCC and LCC2) and human TNBC cell lines MDA-MB-231 (MDA and BrM2) was determined by IF.
Competitive radioligand binding assays with the CB2R-specific ligands [3H]WIN55,212-2 and [3H]A-836339 were performed vs. 10 µM JHU94620-d8, GW405833 and WIN55,212-2, and A 836339 as competitor (n=1). Autoradiography with the CB2R-specific [18F]JHU94620-d8 vs. 10 µM competitor was performed with cryosections obtained from 4T1 tumours (n=3) as well as rat brains harbouring a local overexpression of the human CB2R (AAV-hCB2R, n=1) [4].

Results
A high correlation between the heterogeneously distributed CB2R and Iba1, and a weak correlation between CB2R and CD31 was found in 4T1 tumours. Colocalisation of CB2R and Iba1 (Balb/c: Pearson’s coefficient r=0.69±0.03, Manders’ coefficient M1: 0.7±0.12; NMRI-nude: r=0.7±0.12, M1=0.71±0.15) or CD31 (Balb/c: r=0.35±0.09, M1=0.15±0.02; NMRI-nude: r=0.35±0.11; M1=0.19±0.09) was independent of the mouse breed (CB2R/Iba1: pr=0.9, pM1=0.972; CB2R/CD31: pr=0.41, pM1=0.52).
By IF the expression of CB2R and HER2 was confirmed in HCC and LCC2, but absent in all TNBC cell lines.
The total binding of [3H]WIN55,212-2 in HCC (329.04±37.65 fmol/mg protein) and LCC (160.87±9.53 fmol/mg) homogenates could be reduced by homologues competition with WIN55,212 2 (HCC: 229.66±56.56 fmol/mg, -30.2%; LCC2: 117.73±18.49 fmol/mg, -26.82%) and GW405833 (LCC2: 99.41±2.81 fmol/mg, -38.20%) in contrast to JHU94620-d8. Moreover, a specific binding of [3H]A 836339 was not detectable.
In cryosections of AAV-hCB2R binding of [18F]JHU94620-d8 could be displaced by >80% in the target region with all competitors, however in 4T1 tumours a non-displaceable binding was found.

Conclusions
CB2R expression was detectable in Iba1 positive tumour-associated cells of 4T1 tumours cryosections. In HER2+ cells CB2R expression was cross-validated by IF and competitive binding studies. [18F]JHU94620-d8 binds target specific in the artificial AAV-hCB2R model, whereas heterogenous binding was non-displaceable in cryo-sections of mammary tumours.

The gravitational pressure in many astrophysical objects exceeds one Gigabar (1 billion atmospheres) for a large part of their interior. At theses extreme conditions, matter is compressed to a state where the distance between nuclei becomes as small as the K-shell, containing the most tightly bound electrons, of light elements. These strong interactions of neighbouring particles modify existing bound states and, above a certain pressure, drive the electrons into a delocalised, conducting state. Both modified bound states and increased ionisation significantly affect the equation of state and radiation transport which, in turn, determine the evolution and structure of these objects. Still, our understanding of this transition is far from satisfying and, up to now, experimental data are sparse due to the extreme conditions required. Here, we report on an experiment that creates and diagnoses matter at pressures above 3 Gigabar by utilising the full capabilities of the National Ignition Facility where 184 laser beams were used to implode a beryllium shell, generating highly compressed states. Bright X-ray flashes enable precision radiography and X-ray Thomson scattering measurements revealing both the macroscopic and the microscopic state of the highly compressed beryllium. The inelastic scattering component shows clear signs of quantum degenerate electrons with the density reaching up to 30 times compression, and a temperature of around 2 million Kelvin. At the most extreme conditions, we also observe strongly reduced elastic scattering, which mainly originates from bound K-shell electrons. We attribute this reduction to the onset of delocalisation of the remaining K-shell electron. With this interpretation, the ion charge inferred from the scattering data agrees well with ab initio simulations, but it is significantly higher than widely used models predict. Our results yield a profound understanding of matter in the interior of brown and white dwarfs and will enhance their evolutionary models required to accurately determine the age of stellar populations. They are also imperative for improving the predictive capabilities supporting inertial confinement fusion experiments, ultimately paving the way to an abundant, carbon-free source of energy.

We describe an experimental concept at the National Ignition Facility for specifically tailored spherical im- plosions to compress hydrogen to extreme densities (up to ∼ 800× solid density, electron number density ne ∼ 4 × 10^25 cm−3) at moderate temperatures (T ∼ 200 eV), i.e. to conditions, which are relevant to the interiors of red dwarf stars. The dense plasma will be probed by laser-generated X-ray radiation of differ- ent photon energy to determine the plasma opacity due to collisional (free-free) absorption and Thomson scattering. The obtained results will benchmark radiation transport models, which in the case for free-free absorption show strong deviations at conditions relevant to red dwarfs. This very first experimental test of free-free opacity models at these extreme states will help to constrain where inside those celestial objects energy transport is dominated by radiation or convection. Moreover, our study will inform models for other important processes in dense plasmas, which are based on electron-ion collisions, e.g. stopping of swift ions or electron-ion temperature relaxation.

Control applications targeting fast industrial processes rely on real-time feasible implementations. One of such applications is the stabilization of an electron bunch arrival time in the context of a linear accelerator. In the past, only the electric field accelerating the electron bunches was actively controlled in order to implicitly stabilize the accelerated electron beam. Nowadays, beam properties are specifically measured at a target position and then stabilized by a dedicated feedback loop acting on the accelerating structures. This dedicated loop is usually referred to as a beam-based feedback. Following this, the control system at the linear accelerator ELBE is planned to be upgraded by the beam-based feedback, and the problem of implementing a designed control algorithm becomes highly relevant. In this work, we propose an FPGA-based real-time feasible implementation of a high-order H2 regulator. By presenting the results of the corresponding VHDL simulation and hardware synthesis, we show that the proposed digital solution is fast enough to cover the bunch repetition rates frequently used at ELBE, such as 100 kHz. Finally, we verify the implementation by using a dedicated FPGA testbench.

Extreme conditions inside ice giants like Uranus and Neptune can result in peculiar chemistry and structural transitions, e.g., the precipitation of diamonds or superionic water, as so far experimentally observed only for pure C-H and H2O systems, respectively. Here we investigate a stoichiometric mixture of C and H2O by shock-compressing PET plastics and performing in situ X-ray probing. We observe diamond formation at pressures between 72±7 GPa and 125±13 GPa at temperatures ranging from ~3500 K to ~6000 K. Combining X-ray diffraction and small angle X-ray scattering, we access the kinetics of this exotic reaction. The observed demixing of C and H2O suggests that diamond precipitation inside the ice giants is enhanced by oxygen, which can lead to isolated water and thus the formation of superionic structures relevant to the planets’ magnetic fields. Moreover, our measurements indicate a way of producing nanodiamonds by simple laser-driven shock-compression of cheap PET plastics.

Magnons are elementary excitations in magnetic materials and undergo nonlinear multimode scattering processes at large input powers. In experiments and simulations, we show that the interaction between magnon modes of a confined magnetic vortex can be harnessed for pattern recognition. We study the magnetic response to signals comprising sine wave pulses with frequencies corresponding to radial mode excitations. Three-magnon scattering results in the excitation of different azimuthal modes, whose amplitudes depend strongly on the input sequences. We show that recognition rates above 95\% can be attained for four-symbol sequences using the scattered modes, with strong performance maintained with the presence of amplitude noise in the inputs.

Bone in diabetes mellitus is characterized by an altered microarchitecture caused by abnormal metabolism of bone cells. Together with diabetic neuropathy, this is associated with serious complications including impaired bone healing culminating in complicated fractures and dislocations, especially in the lower extremities, so-called Charcot neuroarthropathy (CN). The underlying mechanisms are not yet fully understood, and treatment of CN is challenging. Several in vitro and in vivo investigations have suggested positive effects on bone regeneration by modifying biomaterials with sulfated glycosaminoglycans (sGAG). Recent findings described a beneficial effect of sGAG for bone healing in diabetic animal models compared to healthy animals. We therefore aimed at studying the effects of low- and high-sulfated hyaluronan derivatives on osteoclast markers as well as gene expression patterns of osteoclasts and osteoblasts from patients with diabetic CN compared to non-diabetic patients with arthritis at the foot and ankle. Exposure to sulfated hyaluronan (sHA) derivatives reduced the exaggerated calcium phosphate resorption as well as the expression of genes associated with bone resorption in both groups, but more pronounced in patients with CN. Moreover, sHA derivatives reduced the release of pro-inflammatory cytokines in osteoclasts of patients with CN. The effects of sHA on osteoblasts differed only marginally between patients with CN and non-diabetic patients with arthritis. These results suggest balancing effects of sHA on osteoclastic bone resorption parameters in diabetes.

2
transparent, with white streak and vitreous luster. No luminescence is observed. Saccoite is uniaxial (–) with refractive indices at 589(1) nm  = 1.705(5) and  = 1.684(2). Pleochroism is distinct, i.e. bluish green (ω) and yellowish green (ε). The chemical composition was studied by means of an electron probe micro-analyser (EPMA) using wavelength-dispersive X-ray spectrometry (WDS). The empirical mineral formula is Ca2.06Mn3+1.78Cu0.10Mg0.07F0.97(OH)8.02(SO4)0.39. The unit-cell dimensions of saccoite (space group P4/ncc) are a = 12.834(3) Å, c = 5.622(2) Å, V = 926.0(4) Å3), and the calculated mass density is 2.73 g·cm-3. Saccoite exhibits a heteropolyhedral framework structure that is composed of edge- and cornersharing CaF2(OH)6 and M(OH)6 polyhedra (M = Mn3+, Cu2+) with large channels along [001], which host disordered and only partially occupied groups, especially SO42-. The hydrogen atoms of the OH groups point into the channel to form hydrogen bonds with the channel anions. Ca–F distances are about 2.3 Å, the Ca–OH distances in the range of 2.44 -2.58 Ǻ, and the M(OH)6 octahedron is strongly 4+2 Jahn-Teller distorted (4 × ~ 1.92 Å, 2 × 2.27 Å). The F atom is tetrahedrally coordinated to calcium atoms. The strongest lines in the X-ray powder pattern [d in Å (relative intensity) (hkl)] are: 9.0735 (35) (110), 4.5370 (95) (220), 4.0644 (20) (310), 3.0105 (100) (321), 2.8117 (20) (002), 2.7242 (75) (411), 1.9755 (35) (611), and 1.8142 (20) (550).

Different SrTiO3 thin films are investigated to unravel the nature of ultra-low conductivities recently found in SrTiO3 films prepared by pulsed laser deposition. Impedance spectroscopy reveals electronically pseudo-intrinsic conductivities for a broad range of different dopants (Fe, Al, Ni) and partly high dopant concentrations up to several percent. Using inductively-coupled plasma optical emission spectroscopy and reciprocal space mapping, a severe Sr deficiency is found and positron annihilation lifetime spectroscopy revealed Sr vacancies as predominant point defects. From synchrotron-based X-ray standing wave and X-ray absorption spectroscopy measurements, a change in site occupation is deduced for Fe-doped SrTiO3 films, accompanied by a change in the dopant type. Based on these experiments, a model is deduced, which explains the almost ubiquitous pseudo-intrinsic conductivity of these films. Sr deficiency is suggested as key driver by introducing Sr vacancies and causing site changes (FeSr and TiSr) to accommodate nonstoichiometry. Sr vacancies act as mid-gap acceptor states, pinning the Fermi level, provided that additional donor states (most probably Ti_Sr) are present. Defect chemical modeling revealed that such a Fermi level pinning also causes a self-limitation of the Ti site change and leads to a very robust pseudo-intrinsic situation, irrespective of Sr/Ti ratios and doping.

In insulators, the longitudinal resistivity becomes infinitely large at zero temperature. For classical insulators, the Hall conductivity becomes zero at the same time. However, there are special systems, such as two-dimensional quantum Hall insulators, in which a more complex scenario is observed at high magnetic fields. Here, we report experimental evidence for a quasiquantized Hall insulator in the quantum limit of the three-dimensional compound SrSi₂. Our measurements reveal a magnetic-field range, in which the longitudinal resistivity diverges with decreasing temperature, while the Hall conductivity approaches a quasiquantized value that is given only by the conductance quantum and the Fermi wave vector in the field direction. The quasiquantized Hall insulator appears in a magnetic field induced insulating ground state of three-dimensional materials and is deeply rooted in quantum Hall physics.

The NeuLAND (New Large-Area Neutron Detector) plastic scintillator based time of flight detector for 0.2-1.6 GeV neutrons is currently under construction at the Facility for Antiproton and Ion Research (FAIR), Darmstadt, Germany. In its final configuration, NeuLAND will consist of 3,000 2.7 m long plastic scintillator bars that are read out on each end by fast timing photomultipliers.

Here, data from a comprehensive study of an alternative light readout scheme using silicon photomultipliers (SiPM) are reported. For this purpose, a typical NeuLAND bar was instrumented on each end with a prototype of the same geometry as a 1'' photomultiplier tube, including four 6x6 mm^2 SiPMs, amplifiers, high voltage supply, and microcontroller.

Tests were carried out using the 35 MeV electron beam from the ELBE superconducting linac with its ps-level time jitter in two different modes of operation, namely parasitic mode with one electron per bunch and single-user mode with 1-60 electrons per bunch, using Acqiris fast digitizers. In addition, offline tests using cosmic rays and the NeuLAND data acquisition scheme were carried out.

Typical time resolutions of sigma <= 100 ps were found for $\geq$99\% efficiency, improving on previous work at ELBE and exceeding the NeuLAND timing goal of sigma < 150 ps. Over a range of 10-300 MeV deposited energy in the NeuLAND bar, the gain was found to deviate by <=10% <=20% from linearity for 35 um (50 um) SiPM pitch, respectively, satisfactory for calorimetric use of the full NeuLAND detector. The dark rate of the prototype studied was found to be 70-200 s^-1, comparable with the unavoidable cosmic-ray induced background.

Silicon, a ubiquitous material in modern computing, is an emerging platform for realizing a source of indistinguishable single photons on demand. The integration of recently discovered single-photon emitters in silicon into photonic structures is advantageous to exploit their full potential for integrated photonic quantum technologies. Here, we show the integration of an ensemble of telecom photon emitters in a two-dimensional array of silicon nanopillars. We developed a top-down nanofabrication method, enabling the production of thousands of nanopillars per square millimeter with state-of-the-art photonic-circuit pitch, all the while being free of fabrication-related radiation damage defects. We found a waveguiding effect of the 1278 nm-G center emission along individual pillars accompanied by improved brightness compared to that of bulk silicon. These results unlock clear pathways to monolithically integrating single-photon emitters into a photonic platform at a scale that matches the required pitch of quantum photonic circuits.

A comprehensive study of direct-contact condensation heat transfer for turbulent, counter-current, liquid/vapour flow in a nearly horizontal channel at high pressure (i.e. 5MPa) has been carried out based on Direct Numerical Simulation (DNS) and highly-resolved Large Eddy Simulation (LES) approaches. To simulate the two-phase flow situation, driven in this case by a constant pressure gradient, a single set of Navier-Stokes equations, coupled with an enthalpy conservation equation, have been employed. The interfacial mass transfer, seen in this case to be dominated by condensation, has been calculated directly from the heat flux at the liquid/vapour interface. To investigate the effect of condensation on the turbulence phenomena, and vice versa, cases have been considered involving two friction Reynolds numbers: namely Re∗ = u∗h/ν = 178 and Re∗ = u∗h/ν = 590 (u∗ = (hΔP/ρ)^1/2). At the lower Reynolds number, three levels of water subcooling – 0K, 10K and 40K – have been investigated. The use of water subcooling of 0K has enabled the validation and verification procedures associated with the numerical approach to be compared against experimental and numerical data reported in the literature. The choice of the maximum degree of water subcooling is dictated by the need to justify the periodic boundary conditions applied in this numerical study. In the simulation for the higher Reynolds number, only the case of 10K subcooling has been included, as a consequence of the very high computation effort involved.

A detailed statistical analysis of the DNS and LES data obtained from the application of the well-known wall laws has also been assessed. In the vicinity of the liquid/vapour interface, the characteristics of the turbulent motions appear somewhat diverse, depending on whether the interface is basically flat or wavy in character. For a flat interface, some damping effect of the presence of the interface on the turbulence intensity has been observed, a feature which becomes enhanced as the level of liquid subcooling is increased. In the case of a wavy interface, the damping effect is predicted as considerably less pronounced.

The between-community beta diversity of fish species - characterized using the similarity of species between river basins shows a non-linear drop with topological distance on river networks. In this work, we investigate the pattern of this drop with network distances and the role of underlying topology. Using the framework of optimal channel networks, the species abundances are evolved under the neutral biodiversity model. We observe that the steady-state species-similarity shows a phase transition-like behaviour at a critical network distance. At this critical distance, the average degree over the nodes crosses the global average degree of the network. This study sheds light on the role of branching in dendritic networks in ecological community assembly rules.

Single-photon sources are one of the elementary building blocks for photonic quantum information and optical quantum computing. One of the upcoming challenges is the monolithic photonic integration and coupling of single-photon emission, reconfigurable photonic elements and single-photon detection on a silicon chip by a controllable manner. To this end, deterministic single-photon sources monolithically integrated with silicon quantum photonic integrated circuits (QPIC) represent a new tool in quantum photonics, complementing heralded probabilistic sources and offering very-large-scale integration (VLSI).
The isolation of single-photon emitters in the optical telecommunication O-band, such as the G centers and W centers, has recently been realized in silicon. In all previous cases, however, single-photon emitters were created randomly and uncontrollably, preventing their scalability. We realize the controllable fabrication of single G and W centers in silicon wafers using focused ion beams with high probability. We also implement a scalable, broad-beam implantation protocol compatible with the complementary-metal-oxide-semiconductor (CMOS) technology to fabricate single telecom emitters in desired positions on the nanoscale.
Our results enable the direct realization of QPIC with monolithically integrated single-photon sources with electrical control. Our findings also provide a route for the quasi-deterministic creation of single G and W centers at desired locations of photonic structures, including SOI waveguides and tunable cavities. This altogether unlocks clear pathways toward the implementation of industrial-scale photonic quantum processors.

The Mu2e experiment [1] at Fermilab will search for the neutrino-less coherent
conversion of a muon into an electron in the field of a nucleus. Mu2e detectors
comprise a strawtracker, an electromagnetic calorimeter and a veto for cosmic
rays. The calorimeter employs 1348 Cesium Iodide crystals readout by silicon
photomultipliers and fast front-end and digitization electronics. The front-end
electronics consists of two discrete chips for each crystal. These provide the
amplification and shaping stage,linear regulation of the SiPM bias voltage and
monitoring. The SiPM and front-end control electronics is implemented in a bat-
tery of mezzanine boards each equipped with an ARM processor that controls
a group of 20 Amp-HV chips, distributes the low voltage and the high-voltage
reference values, sets and reads back the locally regulated voltages. The elec-
tronic is hosted in crates located on the external surface of calorimeter disks.
The crates also host the waveform digitizer board (DIRAC) that performs dig-
itization of the front end signals and transmit the digitized data to the Mu2e
DAQ. Calorimeter electronic is hosted inside the cryostat and it must substain
very high radiation and magnetic field so it was necessary to fully qualify it.
The constraints on the calorimeter front-end and readout electronics, the design
technological choices and the qualification tests will be reviewed.

Radiation of tumor cells can lead to the selection and outgrowth of tumor escape variants. As radioresistant tumor cells are still sensitive to retargeting of T cells, it appears promising to combine radio- with immunotherapy keeping in mind that the radiation of tumors favors the local conditions for immunotherapy. However, radiation of solid tumors will not only hit the tumor cells but also the infiltrated immune cells. Therefore, we wanted to learn how radiation influences the functionality of T cells with respect to retargeting to tumor cells via a conventional bispecific T cell engager (BiTE) and our previously described modular BiTE format UNImAb. T cells were irradiated between 2 and 50 Gy. Low dose radiation of T cells up to about 20 Gy caused an increased release of the cytokines IL2, TNF and interferon-g and an improved capability to kill target cells. Although radiation with 50 Gy strongly reduced the function of the T cells, it did not completely abrogate the functionality of the T cells.

Introduction
Combining MR imaging and beam delivery for image guided precision radiotherapy was already introduced clinically with hybrid MR-linac systems. For proton therapy, given the conformal treatment method as well as the sensitivity to changes in patient anatomy, a hybrid MR and proton therapy device might be even more beneficial. In Dresden, a clinical demonstrator prototype, consisting of an 0.32 T open MR scanner and a horizontal pencil beam scanning beamline was installed. From a medical phyics perspective, the establishment of reliable dosimetry methods is a prerequisite for further pre-clinical and clinical studies.
In MR guided proton therapy (MRgPT), the primary treatment beam itself is influenced by the magnetic field of the scanner. We investigated whether the response of the dosimetry detector depends on the detector orientation with respect to the magnetic field lines.
In this work we focused on potential effects of the 0.32 T magnetic field on commercially available ionization detectors. For photons, considerable orientation effects have been reported. Given the influence of the magnetic field on the particle trajectories, potential orientation effects could have a considerable influence on dosimetric measurements.
Material & Methods
Experiments were performed at the experimental room of the University Proton Therapy Dresden with and without the prototype MRgPT system positioned 58.2 cm downstream of the beam iso-center of the beam line. Four thimble type ionization detectors, a Farmer, a Semiflex, a PinPoint and a PinPoint 3D detector were positioned at 2 cm water-equivalent depth and irradiated using 10 x 15 cm² homogeneous proton fields. Lateral field shifts due to the vertical magnetic field were compensated for. Irradiations were performed for 3 nominal proton energies (100, 150 and 220 MeV) and repeated with the same set-up at 0.32 T (with MR scanner) and 0 T (MR scanner removed). Chambers were positioned in horizontal, vertical and 15° tilted orientation. Magnetic field correction factors were evaluated.

Results
Preliminary results show a small orientation dependence within 0.3 and 1% depending on the chamber, with larger effects for smaller chamber volumes.
A small, but consistent energy dependence of the magnetic field correction factor ranging from 0.5 to 1.6% was determined. The change in correction factors was found to be higher for lower energies as well as smaller sensitive detector volumes.

Discussion
Chamber readings inside an applied magnetic field of 0.32 T were found to depend on detector orientation as well as incident proton energy. For 0 T no noticeable influence was determined. In addition, the effect seems to be more pronounced for small volume chambers. Especially for small volume chambers, such as the PinPoint 3D, it is recommended to introduce a respective correction factor.

The talk introduces the general idea behind the HELIPORT project, which aims to make the entire life cycle of a scientific experiment or project discoverable, accessible, interoperable and reusable by providing an overview from a top-level perspective. Specifically, our data management solution addresses the areas from data generation to publication of primary research data, computing workflows performed and the actual research results.

Although most nuclear spectroscopy as well as atomic hyperfine structure data do not deliver accurate information on nuclear
axiality the ad-hoc assumption of symmetry about one axis found widespread use in nuclear model calculations. In the theoretical
interpretation of nuclear properties as well as in the analysis of experimental data triaxiality was considered – if at all – only
for some, often exotic, nuclides. A breaking of axial symmetry combined to a spin-independent moment of inertia results in a
surprisingly simple heuristic triaxial parametrization of the yrast sequence in all heavy nuclei, including well deformed ones. No
additional fit parameters are needed in detailed studies of the mass and charge dependence of the electric dipole strength in the range
of and outside of giant dipole resonances. Allowing triaxiality also avoids the introduction of an arbitrary level density parameter
˜a to fit the accurate values observed in n-capture experiments and ˜a can be taken from nuclear matter studies. A combination of
this value to the yrast energies no longer based on axiality and the related I(I+1) rule results in agreement to data independent of
spin. And predictions for radiative neutron capture as derived on the basis of non-axiality are improved as well. The experimentally
favoured broken axial symmetry is in accord to HFB and MC-shell model calculations already for nuclei in the valley of stability.

Rationale: Small 225Ac-labeled prostate-specific membrane antigen (PSMA)-targeted radioconjugates have been described for targeted alpha therapy of metastatic castration-resistant prostate cancer. Transient binding to serum albumin as a highly abundant, inherent transport protein represents a commonly applied strategy to modulate the tissue distribution profile of such low-molecular-weight radiotherapeutics and to enhance radioactivity uptake into tumor lesions with the ultimate objective of improved therapeutic outcome.
Methods: Two ligands mcp-M-alb-PSMA and mcp-D-alb-PSMA were synthesized by combining a macropa-derived chelator with either one or two lysine-ureido-glutamate–based PSMA- and 4-(p-iodophenyl)butyrate albumin-binding entities using multistep peptide-coupling chemistry. Both compounds were labeled with [225Ac]Ac3+ under mild conditions and their reversible binding to serum albumin was analyzed by an ultrafiltration assay as well as microscale thermophoresis measurements. Saturation binding studies and clonogenic survival assays using PSMA-expressing LNCaP cells were performed to evaluate PSMA-mediated cell binding and to assess the cytotoxic potency of the novel radioconjugates [225Ac]Ac-mcp-M-alb-PSMA and [225Ac]Ac-mcp-D-alb-PSMA, respectively. The biodistribution of both 225Ac-radioconjugates was investigated in LNCaP tumor-bearing SCID mice. Histological examinations of selected organs were performed to analyze the occurrence of necrosis using H&E staining, DNA damage via γH2AX staining and proliferation via Ki67 expression in the tissue samples.
Results: Enhanced binding to serum components in general and to human serum albumin in particular was revealed for [225Ac]Ac-mcp-M-alb-PSMA and [225Ac]Ac-mcp-D-alb-PSMA, respectively. Moreover, the novel derivatives are highly potent PSMA ligands as their KD values in the nanomolar range (23.38 and 11.56 nM) are comparable to the reference radioconjugates [225Ac]Ac-mcp-M-PSMA (30.83 nM) and [225Ac]Ac-mcp-D-PSMA (10.20 nM) without albumin binders. The clonogenic activity of LNCaP cells after treatment with the 225Ac-labeled ligands was affected in a dose- and time-dependent manner, whereas the dimeric radioconjugate [225Ac]Ac-mcp-D-alb-PSMA has a stronger impact on the clonogenic cell survival than its monomeric counterpart [225Ac]Ac-mcp-M-alb-PSMA. Biodistribution studies performed in LNCaP tumor xenografts showed prolonged blood circulation times for both albumin-binding radioconjugates and a substantially increased tumor uptake (46.04 ± 7.77 %ID/g for [225Ac]Ac-mcp-M-alb-PSMA at 128 h p.i. and 153.48 ± 37.76 %ID/g at 168 h p.i. for [225Ac]Ac-mcp-D-alb-PSMA) with favorable tumor-to-background ratios. Consequently, a clear histological indication of DNA damage was discovered in the tumor tissues, whereas DNA double-strand break formation in kidney and liver sections was less pronounced.
Conclusion: The modification of the PSMA-based 225Ac-radioconjugates with one or two albumin-binding entities resulted in an improved radiopharmacological behavior including a greatly enhanced tumor accumulation combined with a low to neglectable uptake in non-targeted organs.

In this talk I provide an overview of the activities of the FWID department with the focus on curvature effects in magnetic thin films and realization of flexible magnetic field sensors.

Within the last decade, spintronics and magnonics have demonstrated an impressive development in the experimental realization of Boolean logic gates. However, the exponential growth of data and the rise of the internet of things are pushing the deterministic Boolean computing of von-Neumann architectures to their limits or are simply to energy consuming. Moreover, it is accepted commonly that conventional Boolean computer architectures are likely to remain inefficient for certain cognitive tasks in which the human brain excels, such as pattern recognition, particularly when incomplete or noisy data are involved.
One of the most generic and abstract implementations of brain-inspired computing schemes is reservoir computing, where the nonlinear response of a physical system is used to separate patterns hidden in a temporal data stream into distinct manifolds of a higher dimensional output space. In this presentation, I will demonstrate the experimental realization of pattern recognition based on reservoir computing using magnons.
Recently, we reported on the nonlinear scattering of magnons in vortices in micron-sized Permalloy discs [1] which we also learned to control and stimulate by means of other magnons [2]. Now, we utilize these phenomena to employ magnons for pattern recognition without actually relying on magnon transport in real space. I will present a comprehensive overview of experimental results and numerical simulations demonstrating the capabilities and advantages of magnon reservoir computing in reciprocal space.

[1] K. Schultheiss, et al., Physical Review Letters 125, 207203 (2020)
[2] K. Schultheiss, et al., Physical Review Letters 122, 097202 (2019)

Quantitative analyses of cell replication address the connection between metabolism and growth. Various growth models approximate time-dependent cell numbers in culture media, but physio-logical implications of the parametrizations are vague. In contrast, isothermal microcalorimetry (IMC) measures with unprecedented sensitivity to heat (enthalpy) release via chemical turnover in metabolizing cells. Hence, the metabolic activity can be studied independently of modeling the time-dependence of cell numbers. Unexpectedly, IMC traces of various origins exhibit conserved patterns when expressed in the enthalpy domain rather than the time domain, as exemplified by cultures of Lactococcus lactis (prokaryote), Trypanosoma congolese (protozoan) and non-growing Brassica napus (plant) cells. The data comply extraordinarily well with a dynamic Langmuir ad-sorption reaction model of nutrient uptake and catalytic turnover generalized here to the non-constancy of catalytic capacity. Formal relations to Michaelis–Menten kinetics and common analytical growth models are briefly discussed. The proposed formalism reproduces the “life span” of cultured microorganisms from exponential growth to metabolic decline by a succession of distinct metabolic phases following remarkably simple nutrient–metabolism relations. The analysis enables the development of advanced enzyme network models of unbalanced growth and has fundamental consequences for the derivation of toxicity measures and the transferability of metabolic activity data between laboratories.

The European Prevention of Alzheimer Dementia (EPAD) is a multi-center study that aims to characterize the
preclinical and prodromal stages of Alzheimer’s Disease. The EPAD imaging dataset includes core (3D T1w, 3D
FLAIR) and advanced (ASL, diffusion MRI, and resting-state fMRI) MRI sequences.
Here, we give an overview of the semi-automatic multimodal and multisite pipeline that we developed to
curate, preprocess, quality control (QC), and compute image-derived phenotypes (IDPs) from the EPAD MRI
dataset. This pipeline harmonizes DICOM data structure across sites and performs standardized MRI pre-
processing steps. A semi-automated MRI QC procedure was implemented to visualize and flag MRI images next to
site-specific distributions of QC features — i.e. metrics that represent image quality. The value of each of these
QC features was evaluated through comparison with visual assessment and step-wise parameter selection based
on logistic regression. IDPs were computed from 5 different MRI modalities and their sanity and potential clinical
relevance were ascertained by assessing their relationship with biological markers of aging and dementia.
The EPAD v1500.0 data release encompassed core structural scans from 1356 participants 842 fMRI, 831
dMRI, and 858 ASL scans. From 1356 3D T1w images, we identified 17 images with poor quality and 61 with
moderate quality. Five QC features — Signal to Noise Ratio (SNR), Contrast to Noise Ratio (CNR), Coefficient of
Joint Variation (CJV), Foreground-Background energy Ratio (FBER), and Image Quality Rate (IQR) — were
selected as the most informative on image quality by comparison with visual assessment. The multimodal IDPs
showed greater impairment in associations with age and dementia biomarkers, demonstrating the potential of
the dataset for future clinical analyses.

Based on recent calculations of the self-diffusion (SD) coefficient in amorphous silicon (a-Si) by classical Molecular Dynamics simulation [M. Posselt, H. Bracht, and D. Radić, J. Appl. Phys. 131, 035102 (2022)] detailed investigations on atomic mechanisms are performed. For this purpose two Stillinger-Weber-type potentials are employed, one strongly overestimates the SD coefficient, while the other leads to values much closer to the experimental data. By taking into account the individual squared displacements (or diffusion lengths) of atoms the diffusional and vibrational contributions to the total mean squared displacement can be determined separately. It is shown that the diffusional part is not directly correlated with the concentration of coordination defects. The time-dependent distribution of squared displacements of atoms indicates that in a-Si a well-defined elemental diffusion length does not exist, in contrast to SD in the crystalline Si. The analysis of atoms with large squared displacements reveals that the mechanisms of SD in a-Si are characterized by complex rearrangement of bonds or exchange of neighbors. These are mono- and bi-directional exchanges of neighbors and neighbor replacements. Exchange or replacement may concern up to three neighbors and may occur in relatively short periods of some ps. Bi- or mono-directional exchange or replacement of one neighbor atom happen more frequently than processes including more neighbors. A comparison of results for the two interatomic potentials shows that an increased three-body parameter only slows down the migration, but does not change the migration mechanisms fundamentally.

Deep neural networks have by today been established as the goto candidate for semantic or instance segmentation at many scales and image modalities. The pressing challenge in supervised segmentation approaches remains to be the requirement of large annotated image datasets for good performance.
In recent years the expressive capabilities of neural networks have been demonstrated to improve through group convolutional operations which exploit existing symmetries present in the data.
The increased capacity for weight-sharing alongside gains in sample efficiency for training a neural network have led to the empirical success of equivariant neural networks. In our study, we propose and experiment on an equivariant U-net-based model for the task of image segmentation. In this talk, we will discuss our preliminary results on a synthetic datasets consisting of polygonal objects. The results indicate that the performance of our implementation of an equivariant network improves well beyond a vanilla Unet when exposed to symmetrical objects in data different scenarios.

References:

1. Taco S. Cohen, Max Welling, “Group Equivariant convolution networks”, arXiv preprint arXiv: 1602.07576, 2016.
2. Maurice Weiler and Gabriele Cesa, ”General E(2)-Equivariant Steerable CNNs”, NeurIPS 2019.

The electrical properties of single molecules can be investigated using atomically sharp metallic electrodes in mechanically controllable break junctions (MCBJs). The current-voltage (IV) characteristics of single molecules in such junctions are influenced by the binding positions of the end groups on the tip-facets and tip-tip separation. In this talk, we present MCBJ experiments on N,N’-Bis(5-ethynylbenzenethiol-salicylidene)ethylenediamine (Salen). We discuss the evolution of the single level model (SLM) parameters namely, a) the energetic level є of the dominant conducting channel and b) the coupling Γ of the dominant conducting channel to the metallic electrodes. The SLM-parameters were evaluated for IV-curves recorded during opening measurements and fitted to the single level model. We propose a novel, high-throughput approach to model the evolution of the SLM-parameters and explain the recurring peak-like features in the experimentally measured evolution of Γ with increasing tip-tip separation, which we relate to the deformation of the molecule and the sliding of the anchor group above the electrode surface.

There is a general need for alternative structural materials to improve power plants' efficiency and reduce CO2 emissions. Within this framework, two new compositions of temperature-resistant sintered ODS ferritic steels (14Cr-5Al-3W), strengthened by a fine dispersion of precipitates (5·1022 ox. /m3), have been developed. This work focuses on creep properties and microstructure evolution. The creep resistance (at 650°C) could be improved by prior microstructural optimisation, thanks to the consolidation by spark plasma sintering and the tailoring of precipitates' nature when a single compound introduces the oxide-forming elements (Y-Ti-Zr-O) synthesised for this purpose. To this end, the initial pre-alloyed ferritic powder was mechanically alloyed with the synthesised compound and sintered by spark plasma sintering (SPS). Afterwards, EBSD and TEM characterisation were employed to study the microstructures. Small punch creep tests (SPCT) were performed on the steels to analyse their creep performance. These showed an exceptional enhancement of the creep resistance in the steels containing the Y-Ti-Zr-O additions.

Bubble coalescence and breakup is still a complex challenging topic. How far it is understood affects directly the analysis and design optimization of multiphase reactors. Despite years of active research, bubble coalescence in three-phase systems is far from being understood. Contradictory
results on the effect of particles are often reported. Although it still lacks a unique explanation, a general conjecture is that the presence of solid particles affects the film drainage process, and hence the bubble coalescence time and behaviour. This paper presents insights into bubble-pair coalescence in slurry by coupling the multiphase particle in cell (MP-PIC) method with the volume of fluid (VOF) method. The mesh resolution for VOF fields is down to micrometers, which allows for analysis of the film drainage and rupture mechanism in detail. The accuracy of MP-PIC fields during the refinement of CFD grids is guaranteed by a chimera approach (Caliskan and Miskovic, Chemical Engineering Journal Advances 5 (2021) 100054), which allows two overlapping meshes in the Lagrangian-Eulerian framework, namely, a fine mesh for the CFD fields and a coarser mesh for the MP-PIC ones.

Microbial U(VI) reduction influences the uranium mobility in contaminated subsurface environments and can affect the disposal of high-level radioactive waste by transform-ing the water-soluble U(VI) to less mobile U(IV). The reduction of U(VI) by the sulfate-reducing bacterium Desulfosporosinus hippei DSM 8344T, a close phylogenetic relative to naturally occurring microorganism present in clay rock and bentonite, was investigat-ed. D. hippei DSM 8344T showed a relatively fast removal of uranium from the superna-tants in artificial Opalinus Clay pore water. Combined speciation calculations and lumi-nescence spectroscopic investigations showed the dependence of U(VI) reduction on the initial U(VI) species. Scanning transmission electron microscopy coupled with ener-gy-dispersive X-ray spectroscopy showed uranium-containing aggregates on the cell surface and the formation of membrane vesicles. By combining different spectroscopic techniques, including UV/Vis spectroscopy, as well as uranium M4-edge X-ray absorp-tion near-edge structure (XANES) recorded in high-energy-resolution fluorescence-detection (HERFD) mode and extended X-ray absorption fine structure (EXAFS) analy-sis, the partial reduction of U(VI) could be verified, whereby the formed U(IV) product has an unknown structure. Furthermore, the U M4 HERFD-XANES showed the presence of U(V) during the process, suggesting a single-electron transfer mechanism for the microbial U(VI) reduction by sulfate reducers. These findings offer new insights into the U(VI) reduction by sulfate-reducing bacteria and contribute to a comprehensive safety concept for a repository for high-level radioactive waste.

Pressure relief by blowdown is one of the most important measures to prevent excessive pressures in the primary circuit or containment in the event of severe nuclear accidents. Pool scrubbing can significantly reduce the release of radioactive materials, e.g. aerosols, to the environment during the pressure relief. The decontamination factor indicating the particle retention efficiency depends, among other factors, on the hydrodynamic conditions of the gas-liquid two-phase flow inside the pool. In the present work, the hydrodynamics in two typical pool scrubbing experiments is investigated with the two-fluid bubbly flow model, and the influence of some key factors including bubble diameter, nozzle submergence as well as interaction models is analysed. One case is a rectangular pool and the other is a cylindrical column, and their injection Weber number is around 2×103 and 4×105, respectively. The numerical results show that the void fraction and velocity field expand from the central region where the nozzle is located to the whole cross section, as the distance from the nozzle exit increases. The profile as well as its development depends largely on the bubble size and the interaction force model. It reveals that in the monodisperse simulation the tuning of bubble diameter is necessary for achieving good agreement, which is however awkward for high velocity gas injection. More information is required for properly describing the bubble size distribution as well as its evolution in pool scrubbing conditions. Furthermore, the experimental data show clear drag reduction in the bubble swarm generated by the gas jet, and further investigations on the mechanism and model improvement have to be done.

We present a preliminary study of the electrode design of an electrical impedance spectroscopy (EIS) system for fouling detection in heat exchangers. In this study, a basic model of a heat exchanger is created based on finite element method (FEM). Here, an invasive and non-invasive electrode configuration was investigated. Numerical results show that both invasive and non-invasive electrode configurations are suitable for detecting fouling using impedance spectroscopy. The invasive one showed a better contrast between the fouling and non-fouling scenarios. However, from a practical point of view, the latter is preferable in our application since it does not disturb the surface where fouling is formed.

We created a test cell to design a measurement system based on electrical impedance spectroscopy for heat exchangers. In the experimental heat exchanger, the working electrode is connected to the earth potential for safety reasons. To avoid short-circuiting, an isolation transformer to decouple the impedance analyzer from earth potential was used, thus allowing the detection and characterization of thin fouling layers even if the working electrode is still connected to earth.

The performance of hydrocyclones at Buzwagi Gold Mine (BGM) was investigated in three full scale survey campaigns. Thereafter, several empirical and theoretical hydrocyclone models were used for prediction of hydrocyclone performance. The survey data revealed poor performance of the grinding circuit caused by a circulating load higher than the design. Further, the poor performance of the grinding circuit had consequences on hydrocyclones overflow particle size (i.e. a much coarser product, xP,80 > 200 µm) than target (125 µm). In addition, the operation indicates overloading of the hydrocyclones due to feed rates being 10–18% above the design capacity. Apart from their deficiencies, BGM hydrocyclones can be categorized as very good or excellent separators in terms of separation efficiency based on partition curves, T(x). The modelling of BGM hydrocyclones revealed that Nageswararao’s model can well describe and predict the operation and is recommended for future simulation and optimization of the operation. Based on the survey data, there are opportunities to improve current operation through adjustment of operating conditions like dilution of hydrocyclone feed for improved classification efficiency.

When liquid metal batteries are charged or discharged, strong electrical currents are
passing through the three liquid layers that we find in their interior. This may result in
the metal pad roll instability that drives gravity waves on the interfaces between the layers.
In this paper, we investigate theoretically metal pad roll instability in idealised cylindrical
liquid metal batteries that were simulated previously by Weber et al. (Phys. Fluids, vol.
29, no. 5, 2017b, 054101) and Horstmann et al. (J. Fluid Mech., vol. 845, 2018, pp. 1–35).
Near the instability threshold, we expect weakly destabilised gravity waves, and in this
parameter regime, we can use perturbation methods to find explicit formulas for the growth
rate of all possible waves. This perturbative approach also allows us to include dissipative
effects, hence we can locate the instability threshold with good precision. We show that
our theoretical growth rates are in quantitative agreement with previous and new direct
numerical simulations. We explain how our theory can be used to estimate a lower bound
on cell size beneath which metal pad roll instability is unlikely.

Daten, die für die Veröffentlichung "ExponatONE: eine hochpräzise Kleintierbestrahlungsanlage mit Protonenradiographie" verwendet wurden.
Das Repository enthält alle Daten, die zur Erstellung der quantitativen Ergebnisse und Abbildungen im eingereichten Manuskript verwendet wurden.
Satz von Skripten zur Aufnahme und Verarbeitung von Radiografiebildern/CTs, wie im zugehörigen Paper beschrieben.
Bei dem Datensatz handelt es sich um alle verwendeten Bilder und Grafen (CT, Röntgenbilder, Radiografiebilder, Simulationen, Mikroskopiebilder) für die Auswertung der Ergebnisse und die Darstellung in den Figures.

The β-emitting 99Tc isotope is a high-yield fission product in 235U and 239Pu nuclear reactors, raising special concern in nuclear waste management due to its long half-life and the high mobility of pertechnetate (TcO4−). In the conditions of deep nuclear waste repositories, retention of Tc is achieved via biotic and abiotic reduction of TcO4− to compounds like amorphous TcO2·xH2O precipitates. It is generally accepted that these precipitates have linear (Tc(μ O)2(H2O)2)n chains, with trans H2O. Although corresponding Tc Tc and Tc O distances have been obtained from Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, this structure is largely based on analogy with other compounds. Here, we combine Density-Functional Theory with EXAFS measurements of fresh and aged samples to show that, instead, TcO2·xH2O forms zigzag chains that undergo a slow aging process whereby they combine to form longer chains and, later, a tridimensional structure that might lead to a new TcO2 polymorph.

⁹⁴Nb (half-life of 2.03x10⁴ a) is part of the radioactive inventory of the waste in the dismantling process of nuclear power plants. Half-life (34.991 d) and decay mode point out ⁹⁵Nb as appropriate isotopic radiotracer to investigate the fate of ⁹⁴Nb in future waste repositories.

In this study, the coordinate transformation technique was assessed for radial expansion of Sodium cooled Fast Reactor (SFR) cores with the focus on time-dependent calculations. This method was implemented into nodal diffusion code DYN3D and was tested against the already available direct mesh expansion model. The newly implemented method was tested for uniform radial core expansion cases. Within DYN3D, the coordinate transformation method was verified on steady-state cases and was validated on one of the transient scenarios from the Phenix reactor experiments. The obtained results demonstrate equivalence between the coordinate transformation and direct mesh expansion techniques and therefore presenting the viability of the former one in transient calculations of SFR cores.

Certain f-block elements—the lanthanides—have biological relevance in the context of methylotrophic bacteria. The respective strains incorporate these 4 f elements into the active site of one of their key metabolic enzymes, a lanthanide-dependent methanol dehydrogenase. In this study, we investigated whether actinides, the radioactive 5 f elements, can replace the essential 4 f elements in lanthanide-dependent bacterial metabolism. Growth studies with Methylacidiphilum fumariolicum SolV and the Methylobacterium extorquens AM1 ΔmxaF mutant demonstrate that americium and curium support growth in the absence of lanthanides. Moreover, strain SolV favors these actinides over late lanthanides when presented with a mixture of equal amounts of lanthanides together with americium and curium. Our combined in vivo and in vitro results establish that methylotrophic bacteria can utilize actinides instead of lanthanides to sustain their one-carbon metabolism if they possess the correct size and a +III oxidation state.

The electrical properties of single molecules can be investigated using atomically sharp metallic electrodes in mechanically controllable break junctions (MCBJs). The current-voltage (IV) characteristics of single molecules in such junctions are affected by the binding positions of the end groups on the tip-facets and tip-tip separation. In this poster, we present MCBJ experiments on N,N’-Bis(5-ethynylbenzenethiol-salicylidene)ethylenediamine (Salen). We discuss the evolution of the single level model (SLM) parameters namely, a) the energetic level (epsilon) of the dominant conducting channel and b) the coupling (Gamma) of the dominant conducting channel to the metallic electrodes. The SLM-parameters were evaluated for IV-curves recorded during opening measurements and fitted to the single level model. We explain the recurring peak-like features/protusions in the experimentally measured evolution of Gamma with increasing tip-tip separation, which we relate not only to the deformation of the molecule but also to the sliding of the anchor group above the electrode surface. We propose a novel, high-throughput approach to model the evolution of the SLM-parameters and perform transport calculations using the self-consistent charge scheme of the density-functional-based tight binding (SCC-DFTB) approach and the Green’s function formalism. Thereby, we consider many thermodynamically relevant configurations and assess the evolution of SLM-parameters using the SLM-curve fitting of the zero-bias transmission. The SLM-parameters are averaged using statistical weights obtained from a Metropolis simulation considering up to 200 000 configurations for selected tip-tip separations. The behavior of the averaged quantities with respect to the tip-tip separation reflects the experimentally observed evolution of the SLM-parameters astonishingly well.

The structural modifications occurring in zeolites upon heating are of interest because of technological and industrial applications. In this study, we report the anomalous behaviour of a Pb-exchanged zeolite (Pb13.4(OH)10Al17.4Si54.6O144 ∙38H2O) with STI framework type. For the first time, we observed a switch forom negative to positive thermal expansion during continuous heating. The dehydration was tracked in situ from 25 to 450 °C by single crystal X-ray diffraction, infrared, and X-ray absorption spectroscopy. Furthermore, toTo assist interpretation of the experimental results, molecular dynamics simulations were performed on a series of different theoretical models. Initially, Pb-STI unit-cell volume contracts (ΔV = -3.5%) from 25 to 100°C. This is in line with the trend observed in STI zeolites. Surprisingly, at 125°C, the framework expanded (ΔV = +2%), adopting a configuration, which resembles that of the room temperature structure. Upon heating, the structure loses H2O but no de-hydroxylation occurred. This behaviour is explained via the formation of Pbx(OH)x (x= 2,4) clusters, which prevent the shrinking of the channels, rupture of the tetrahedral bonds and occlusion of the pores. This zeolite has therefore an increased thermal stability with respect to other STI metal-exchanged zeolites, with important consequences foron its applications.

This book presents a timely and fundamental overview of magnetism in curved geometries, highlighting numerous peculiarities emerging from geometrically curved magnetic objects such as curves wires, shells, as well as complex three-dimensional structures. Extending planar two-dimensional structures into the three-dimensional space has become a general trend in multiple disciplines across electronics, photonics, plasmonics and magnetics. This approach provides the means to modify conventional and even launch novel functionalities by tailoring the local curvature of an object. The book covers the theory of curvilinear micromagnetism as well as experimental studies of curved magnets including both fabrication and characterization. With its coverage of theoretical and fundamental aspects, together with exploration of numerous applications across magnonics, bio-engineering, soft robotics and shapeable magnetoelectronics, this edited collection is ideal for all scientists in academia and industry seeking an overview and wishing to keep abreast of advances in the novel field of curvilinear micromagnetism. It provides easy but comprehensive access to the field for newcomers, and can be used for graduate-level courses on this subject.

In this chapter, we extend the discussion of curvature effects in magnetism towards the description of
geometrically curved magnetic thin shells. A self-consistent micromagnetic framework of curvilinear
magnetism describes the impact of curvature–induced effects, driven by both local and nonlocal
interactions, on the statics and dynamics of magnetic textures in extended curved thin shells. In particular,
we focus on the effects in magnetic thin films with in-plane and out-of-plane easy axis of magnetization on
spherical, cone-, bump-, and indentation-like objects. The special interest will be addressed to skyrmions in
curved magnetic films. Statics of skyrmions as well as their magnetization dynamics will be considered.
We provide an overview of relevant experimental methods, which allow fabricating these geometrically
curved extended thin films including nanosphere lithography, ion beam induced surface patterning and also
chemical synthesis approaches to realize metal and oxide hollow nanostructures with a tunable
morphology. We anticipate that the strong theoretical background on the fundamental understanding of the
curvature effects in geometrically curved magnetic shells and the availability of the fabrication methods to
produce these architectures will stimulate experimental activities targeting the validation of the exciting
theoretical predictions including curvature–induced skyrmions, pinning of chiral domain walls on local
bends and exploring novel nonlocal chiral symmetry breaking effects.

The concept of curvilinear magnetism can be applied to a wide range of materials and targets the
applications where the interplay of geometry, shape, and magnetic texture arises. A clear advantage of
these deformable magnetic materials is that they can be used for applications that demand flexibility or
stretchability, something that conventionally rigid ferromagnets cannot provide. This advantage can be
readily exploited in the field of flexible electronics, which aims to create electronic circuits and devices
that can be folded or bent upon usage. The firm link between the fundamentals and applications of curved
magnetic thin films is given by the fact that magnetic domain walls can be pinned at bends.
This fundamental discovery has deep consequences for magnetic field sensors based on geometrically
curved magnetic thin films. Indeed, curvature of the structure results in an additional pinning mechanism
for domain walls, which can lead to the enhancement of the coercive field and hence lower the sensitivity
of magnetic field sensors. These considerations came up very recently and its consequences are still to be
explored and confirmed experimentally. Here, we will discuss primary the current advances in the
application of flexible magnetic field sensors based on geometrically curved magnetic thin films and
multilayers. Based on this technology, we present and foresee a wide range of applications in the fields of
eMobility, health, and interactive electronics. The latter is the main focus of this chapter, in particular due
to the added value of flexible magnetoelectronics to the fields of human-machine interfaces and virtual or
augmented reality.

L-[11C]Methionine ([11C]Met) is frequently used for the diagnosis of tumours located in brain, head and neck or for tumours induced by the multiple myeloma. The radio synthesis of [11C]Met commonly starts with [11C]CO2 with subsequent transformation to [11C]CH4 followed by transfer into [11C]CH3I which is used for final labelling of the precursor L-homocystein thiolactone hydrochloride (HCTL). [1,2] By performing these steps with the TRACERLab FXC-pro System (GE HC), however, we observed inconstant radiochemical yields and high maintenance efforts especially of the absorber material used within the gas phase iodination. Accordingly, we have searched for optimization of this radio synthesis procedure.

Free-electron lasers: past, present, and future challenges

As well known, the quality of the photocathodes is essential for the stability and the reliability of photo injector operation. Especially for the superconducting ratio frequency photo injectors (SRF guns), the photocathode represents one of the most critical parts. Benefit from the fast de-veloping photocathode technology in last years, several SRF guns were successfully operated or tested for the beam generation at kHz - MHz repetition rate. In this paper, we will review the achievements as well as the open questions in the applications of the photocathodes for SRF gun operation. Furthermore, we will discuss the possible improvement from cathodes side for the future CW electron sources.

The stability of structural materials in extreme nuclear reactor environments—with high temperature, high radiation and corrosive media—directly affects the lifespan of the reactor. In such extreme environments, an oxide layer on the metal surface acts as a passive layer protecting the metal underneath from corrosion. To predict the irradiation effect on the metal layer in these metal/oxide bilayers, nondestructive depth-resolved positron annihilation lifetime spectroscopy (PALS) and complementary transmission electron microscopy (TEM) were used to investigate small-scale defects created by ion irradiation in an epitaxially grown (100) Fe film capped with a 50 nm Fe2O3 oxide layer. In this study, the evolution of induced vacancies was monitored, from individual vacancy formation at low doses—10^-5 dpa—to larger vacancy cluster formation at increasing doses, showing the sensitivity of positron annihilation spectroscopy techniques. Furthermore, PALS measurements reveal how the presence of a metal-oxide interface modifies the distribution of point defects induced by irradiation. TEM measurements show that irradiation induced dislocations at the interface is the mechanism behind the redistribution of point defects causing their accumulation close to the interface. This work demonstrates that the passive oxide layers formed during corrosion impact the distribution and accumulation of radiation induced defects in the metal underneath, and emphasizes that the synergistic impact of radiation and corrosion will differ from their individual impacts.

Technetium (Tc) is an environmentally relevant radioactive contaminant whose migration is limited when Tc(VII) is reduced to Tc(IV). However, its reaction mechanisms are not well understood yet. We have combined electrochemistry, spectroscopy, and microscopy (cyclic voltammetry, rotating disk electrode, X-ray photoelectron spectroscopy, and Raman and scanning electron microscopy) to study Tc(VII) reduction in non-complexing media: 0.5 mM KTcO₄ in 2 M NaClO₄ in the pH from 2.0 to 10.0. At pH 2.0, Tc(VII) first gains 2.3 ± 0.3 electrons, following Tc(V) rapidly receives 1.3 ± 0.3 electrons yielding Tc(IV). At pH 4.0−10.0, Tc(IV) is directly obtained by transfer of 3.2 ± 0.3 electrons. The reduction of Tc(VII) produced always a black solid identified as Tc(IV) by Raman and XPS. Our results
narrow a significant gap in the fundamental knowledge of Tc aqueous chemistry and are important to understand Tc speciation.
They provide basic steps on the way from non-complexing to complex media.

For purposes of chelation therapy and radiation protection, aminopolycarboxylic acids like ethylenediaminetetraacetic acid (EDTA) or diethylenetriaminepentaacetic acid (DTPA) are clinical approved decorporation agents against lanthanides (Ln) and actinides (An). This well known group of chelating agents shows promising results in complexation of Ln(III)/An(III). For EDTA and DTPA related compound ethylene glycol-bis(β-aminoethyl ether)-N,N,N’,N’-tetraacetic acid (EGTA), complexes with trivalent europium (Eu) have been characterized by NMR spectroscopy and x-ray diffraction. In these complexes, EGTA acts as an octadentate ligand.[1][2] In this work the knowledge on the Eu-EGTA-system is extended by time-resolved laser-induced fluorescence spectroscopy (TRLFS), electrospray ionization mass spectrometry (ESI-MS) and isothermal titration calorimetry (ITC). These speciation studies on Eu(III) show promising results for EGTA as complexing agent.
To expand this ligand group, EGTA related ligands are synthesized. With these compounds, the complexation behaviour towards Eu(III) and curium(III) are determined and comprehensively characterised from both the ligands and metals perspective with TRLFS, NMR spectroscopy, single crystal x-ray diffraction and fourier-transform infrared spectroscopy. The overall goal is a better understanding between ligand design and affinity to trivalent lanthanides and actinides. Hence, in the future these ligands may contribute to chelation therapy as decorporation agents.
This work is funded by the German Federal Ministry of Education and Research (BMBF) under grant number 02NUK057A and part of the joint project RADEKOR.

[1]. S. Aime, A. Barge, A. Borel, M. Botta, S. Chemerisov, A. E. Merbach, U. Müller, D. Pubanz, Inorg. Chem. 1997, 36, 5104.
[2]. R. Xu, D. Li, J. Wang, Y. X. Kong, B. X. Wang, Y. M. Kong, T. T. Fan, B. Liu, Russ. J. Coord. Chem. 2010, 36, 810.

Purpose: We tested the hypothesis that gene expressions from biopsies of locally advanced head and neck squamous cell carcinoma (HNSCC) patients can supplement dose-volume parameters to predict dysphagia and xerostomia following primary radiochemotherapy (RCTx).
Material and methods: A panel of 178 genes previously related to radiochemosensitivity of HNSCC was considered for nanoString analysis based on tumour biopsies of 90 patients with locally advanced HNSCC treated by primary RCTx. Dose-volume parameters were extracted from the parotid, subman-
dibular glands, oral cavity, larynx, buccal mucosa, and lips. Normal tissue complication probability (NTCP) models were developed for acute, late, and for the improvement of xerostomia grade ≥2 and dysphagia grade ≥3 using a cross-validation-based least absolute shrinkage and selection operator (LASSO) approach combined with stepwise logistic regression for feature selection. The final signatures were included in a logistic regression model with optimism correction. Performance was assessed by the area under the receiver operating characteristic curve (AUC).
Results: NTCP models for acute and late xerostomia and the improvement of dysphagia resulted in optimism-corrected AUC values of 0.84, 0.76, and 0.70, respectively. The minimum dose to the contra-lateral parotid was selected for both acute and late xerostomia and the minimum dose to the larynx was selected for dysphagia improvement. For the xerostomia endpoints, the following gene expressions were selected: RPA2 (cellular response to DNA damage), TCF3 (salivary gland cells development), GBE1 (glycogen storage and regulation), and MAPK3 (regulation of cellular processes). No gene expression features were selected for the prediction of dysphagia.
Conclusion: This hypothesis-generating study showed the potential of improving NTCP models using gene expression data for HNSCC patients. The presented models require independent validation before potential application in clinical practice.

Various copper oxide stoichiometries have been grown by Pulsed Laser Deposition (PLD) on MgO (100). The role of oxygen pressure on the structural and physical properties of the films was investigated in the 1·10 –5 Pa – 1 Pa range. Positron annihilation spectroscopy revealed positrons trapped at vacancies and large vacancy clusters with lifetimes ranging from 400 ps to 500 ps. Different stoichiometries were found to be dominated by characteristic vacancies. Single copper vacancies V Cu are found for CuO phase with good indication for p-type applications while for the Cu 2 O complexes of copper vacancies coupled with oxygen vacancies (V Cu + V O and V Cu + 2V O ) are seen. Particular O 2 atmosphere conditions induce a mixture of copper oxide phases with the CuO crystals growing on top of Cu 2 O films. The deposition process was monitored with in situ diagnostic techniques based on optical emission spectroscopy and Langmuir probe method. The kinetics of the plasma during the deposition process are well correlated with the properties of the deposited films.
The monitoring tools define clear energetic threshold for the formation of CuO or Cu 2 O phases.

In recent years, the application focus of phage surface display (PSD) technology has been extended to the identification of metal ion-selective peptides. In previous studies, two phage clones - a nickel-binding one with the peptide motif CNAKHHPRCGGG and a co-balt-binding one with the peptide motif CTQMLGQLCGGG - were isolated and their binding ability to metal-loaded NTA agarose beads was investigated. Here, the free cyclic peptides are characterized by UV/VIS spectroscopy and with respect to their binding capacity for the respective target ion as well as in crossover experiments for the other ion by isothermal titration calorimetry (ITC) in different buffer systems. This revealed differences in selectivity and affinity. While the cobalt-specific peptide is very sensitive to different buffers, but has a 20-fold higher affinity for cobalt and nickel under suitable conditions, the nickel-specific peptide binds more moderately and robustly in different buffers, but selectively only nickel.

The contactless inductive flow tomography is a procedure that enables the reconstruction of the global three-dimensional flow structure of an electrically conducting fluid by measuring the flow-induced perturbation of an applied static magnetic field and by subsequently solving the associated linear inverse problem. The method enables the visualisation of the dynamics of a large-scale circulation in the modified Rayleigh-Bénard experiment.

Abstract: (1) Background: Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) who are at biologically high risk for the development of loco-regional recurrences af-ter postoperative radiotherapy (PORT) but at intermediate risk according to clinical risk factors may benefit from additional concurrent chemotherapy. In this matched-pair study, we aimed to identify a corresponding predictive gene signature. (2) Methods: Gene expression analysis was performed on a multicentre retrospective cohort of 221 patients that were treated with postoper-ative radiochemotherapy (PORT-C) and 283 patients that were treated with PORT alone. Propen-sity score analysis was used to identify matched patient pairs from both cohorts. From differen-tial gene expression analysis and Cox regression, a predictive gene signature was identified. (3) Results: 108 patient matched patient pairs were selected. We identified a 2-metagene signature that stratified patients into risk groups in both cohorts. The comparison of the high-risk patients between the two types of treatment showed higher LRC after treatment with PORT-C (p<0.001), which was confirmed by a significant interaction term in Cox regression (p=0.027), i.e. the 2-metagene signature was indicative for the type of treatment. (4) Conclusion: We have identi-fied a novel gene signature that may be helpful to identify patients with high-risk HNSCC amongst those at intermediate clinical risk treated with PORT, who may benefit from additional concurrent chemotherapy.

Electrical impedance spectroscopy (EIS) is a powerful technique and observed to be more sensitive to complex composite and hydration which provides the estimated solution to our questions. Therefore, this letter deals with some of the preliminary results of the research. It reflects upon studying the complex electrical properties of the cementitious material through the numerical analysis over the range of 1 Hz to 10 MHz frequencies for dry and moist concrete samples.

The important role of structure homogeneity in three-dimensional network nanostructures serving as noble metal aerogels (NMAs) has attracted extensive attention in the field of electrochemistry in the last two decades, whereas a comprehensive study of tailoring skeleton units and element distributions in NMAs is still lacking. Herein, a new modulation strategy to easily prepare multiscale NMAs with tunable composition is developed by utilizing the electrostatic interaction between oppositely charged colloidal metal nanoparticles. The modulation rule of the chemical distribution in bimetallic aerogels leads to the construction of the as-tailored double skeleton aerogels for the first time. Considering their specific structures, the intrinsic and exceptional catalytic and electrocatalytic performances of NMAs were investigated. This study optimizes the structure homogeneity of noble metal aerogels by investigating nanoparticle–ligand interactions and provides further proof of their exceptional electrocatalytic
capabilities.

Binary magnetic alloys like Co-Pt are relevant for applications as components of magnetic exchange coupled composites. Numerous approaches exist to tune the coercive field of Co-Pt alloys primarily relying on hightemperature processing aiming to realize chemically long-range ordered phases. The peculiarity of Co-Pt is that large coercive field and magnetic anisotropy can be achieved even in chemically disordered alloys relying on short-range order. Here, we study alloying of Co-Pt from bilayers of Pt(14 nm) Co(13 nm) at temperatures up to 550 degС, where bulk diffusion processes are suppressed and the dominant diffusion mechanism is grain boundary migration. We demonstrate that grain boundary diffusion mechanism can lead to the realization of a homogeneous yet chemically disordered Co56Pt44 alloy at temperatures of 500 degС and higher. A pronounced increase of the coercive field for samples processed at temperatures higher than 400 degС is attributed to short-range ordering. With this work, we pinpoint the grain boundary diffusion as the mechanism responsible not only for the homogenization of binary alloy films but also as a driving force for the realization of short-range order in Co-Pt. Our results motivate further research on grain boundary diffusion as a mechanism to realize chemically long-range ordered phases in Co-Pt alloys.

Proline-catalyzed aldol reactions have been developed as an important toolbox for the synthesis of valuable chiral intermediates, giving birth to asymmetric organocatalysis. Despite progress, their current applications are generally performed in highly polar solvents that are either difficult to remove or with low substrate/product solubility. In addition, prolines are often used as homogeneous organocatalysts in these solvents, thus, the recycling of catalyst for reuse is also challenging. To solve these problems, we develop a proline-based Pickering emulsion for asymmetric aldol reactions with high reactivity and selectivity. The emulsion was stabilized by proline-functionalized silica nanoparticles that are not only highly active in the presence of water but also easily recycled after the operation. Interestingly, their high stereoselectivity was not compromised after multiple reuse, i.e., >86 ee (enantiomeric excess) in the first and second use. With this demonstration, we prove the concept that efficient and selective aldol reactions are enabled by proline-based Pickering emulsions, which is a great and continuous contribution to the field of asymmetric organocatalysis.

The natural bacterial spores have inspired the development of artificial spores, through coating cells with protective materials, for durable whole-cell catalysis. Despite attractiveness, artificial spores developed to date are generally limited to a few microorganisms with their natural endogenous enzymes, and they have never been explored as a generic platform for widespread synthesis. Here, we report a general approach to designing artificial spores based on Escherichia coli cells with recombinant enzymes. The artificial spores are simply prepared by coating cells with polydopamine, which can withstand UV radiation, heating and organic solvents. Additionally, the protective coating enables living cells to stabilize aqueous-organic emulsions for efficient interfacial biocatalysis ranging from single reactions to multienzyme cascades. Furthermore, the interfacial system can be easily expanded to chemoenzymatic synthesis by combining artificial spores with metal catalysts. Therefore, this artificial-spore-based platform technology is envisioned to lay the foundation for nextgeneration cell factory engineering.

Modern radiotherapy and advances in systemic treatments are
leading to higher tumour control rates and longer survival rates,
thereby the number of long-term survivors of malignant tumours
is increasing. Therefore, minimising late and very late side
effects including radiation-induced secondary malignancies is par-
ticularly important. Accurate quantification of such sequelae is
only possible through very long, optimistically lifelong follow-up
of patients and comprehensive cancer registers

Tumor heterogeneity and cellular plasticity are key determinants of tumor progression, metastatic spread, and therapy
response driven by the cancer stem cell (CSC) population. Within the current study, we analyzed irradiation-induced
plasticity within the aldehyde dehydrogenase (ALDH)-positive (ALDH+) population in prostate cancer. The radiosensitivity of
xenograft tumors derived from ALDH+ and ALDH-negative (ALDH-) cells was determined with local tumor control analyses
and demonstrated different dose-response profiles, time to relapse, and focal adhesion signaling. The transcriptional
heterogeneity was analyzed in pools of 10 DU145 and PC3 cells with multiplex gene expression analyses and illustrated a
higher degree of heterogeneity within the ALDH+ population that even increases upon irradiation in comparison with ALDH-
cells. Phenotypic conversion and clonal competition were analyzed with fluorescence protein-labeled cells to distinguish
cellular origins in competitive three-dimensional cultures and xenograft tumors. We found that the ALDH+ population
outcompetes ALDH- cells and drives tumor growth, in particular upon irradiation. The observed dynamics of the cellular state
compositions between ALDH+ and ALDH- cells in vivo before and after tumor irradiation was reproduced by a probabilistic
Markov compartment model that incorporates cellular plasticity, clonal competition, and phenotype-specific radiosensitivities.
Transcriptional analyses indicate that the cellular conversion from ALDH- into ALDH+ cells within xenograft tumors under
therapeutic pressure was partially mediated through induction of the transcriptional repressor SNAI2. In summary,
irradiation-induced cellular conversion events are present in xenograft tumors derived from prostate cancer cells and may be
responsible for radiotherapy failure. IMPLICATIONS: The increase of ALDH+ cells with stem-like features in prostate
xenograft tumors after local irradiation represents a putative cellular escape mechanism inducing tumor radioresistance.

Negatively charged boron vacancies (VB−) in hexagonal boron nitride (hBN) exhibit a broad emission spectrum
due to strong electron−phonon coupling and Jahn−Teller mixing of electronic states. As such, the direct measurement of the zero-
phonon line (ZPL) of VB− has remained elusive. Here, we measure the room-temperature ZPL wavelength to be 773 ± 2 nm by
coupling the hBN layer to the high-Q nanobeam cavity. As the wavelength of cavity mode is tuned, we observe a pronounced
intensity resonance, indicating the coupling to VB−. Our observations are consistent with the spatial redistribution of VB−
emission. Spatially resolved measurements show a clear Purcell effect maximum at the midpoint of the nanobeam, in accord with
the optical field distribution of the cavity mode. Our results are in good agreement with theoretical calculations, opening the way to using VB− as cavity spin−photon interfaces.

1-(4-Fluorobenzoyl)-9H-carbazole (1) was synthesized starting from 9H carbazole and 4-fluorobenzonitrile by Friedel-Crafts acylation using boron trichloride to direct the substitu-tion in 1-position. Single X-ray crystal structure analysis unambiguously revealed the molecular structure of 1.

Background and purpose: Prognosis after chemoradiotherapy (CRT) for anal squamous cell carcinoma
(ASCC) shows marked differences among patients according to TNM subgroups, however individualized
risk assessment tools to better stratify patients for treatment (de-) escalation or intensified follow-up are
lacking in ASCC.
Materials and methods: Patients’ data from eight sites of the German Cancer Consortium - Radiation
Oncology Group (DKTK-ROG), comprising a total of 605 patients with ASCC, treated with standard defini-
tive CRT with 5-FU/Mitomycin C or Capecitabine/Mitomycin C between 2004–2018, were used to evalu-
ate prognostic factors based on Cox regression models for disease-free survival (DFS). Evaluated variables
included age, gender, Karnofsky performance score (KPS), HIV-status, T-category, lymph node status and
laboratory parameters. Multivariate cox models were separately constructed for the whole cohort and
the subset of patients with early-stage (cT1-2 N0M0) tumors.
Results: After a median follow-up of 46 months, 3-year DFS for patients with early-stage ASCC was 84.9%,
and 67.1% for patients with locally-advanced disease (HR 2.4, p < 0.001). T-category (HR vs. T1: T2 2.02;
T3 2.11; T4 3.03), N-category (HR versus N0: 1.8 for N1-3), age (HR 1.02 per year), and KPS (HR 0.8 per
step) were significant predictors for DFS in multivariate analysis in the entire cohort. The model per-
formed with a C-index of 0.68. In cT1-2N0 patients, T-category (HR 2.14), HIV status (HR 2.57), age
(1.026 per year), KPS (HR 0.7 per step) and elevated platelets (HR 1.3 per 100/nl) were associated with
worse DFS (C-index of 0.7).
Conclusion: Classical clinicopathologic parameters like T-category, N-category, age and KPS remain to be
significant prognostic factors for DFS in patients treated with contemporary CRT for ASCC. HIV and plate-
lets were significantly associated with worse DFS in patients with early stage ASCC.

Introduction: During the first wave of the COVID-19 pandemic in 2020, the German
government implemented legal restrictions to avoid the overloading of intensive care units
by patients with COVID-19. The influence of these effects on diagnosis and treatment of
cancer in Germany is largely unknown.
Methods: To evaluate the effect of the first wave of the COVID-19 pandemic on tumor
board presentations in a high-volume tertiary referral center (the German Comprehensive
Cancer Center NCT/UCC Dresden), we compared the number of presentations of
gastrointestinal tumors stratified by tumor entity, tumor stage, and treatment intention
during the pandemic to the respective data from previous years.
Results: The number of presentations decreased by 3.2% (95% CI −8.8, 2.7) during the
COVID year 2020 compared with the pre-COVID year 2019. During the first shutdown,
March–May 2020, the total number of presentations was 9.4% (−18.7, 1) less than during
March–May 2019. This decrease was significant for curable cases of esophageal cancer
[N =37, 25.5% (−41.8, −4.4)] and colon cancer [N =36, 17.5% (−32.6, 1.1)] as well as
for all cases of biliary tract cancer [N =26, 50% (−69.9, −15)] during the first shutdown
from March 2020 to May 2020.
Conclusion: The impact of the COVID-19 pandemic on the presentation of oncological
patients in a CCC in Germany was considerable and should be taken into account when
making decisions regarding future pandemics.

Although radiation therapy has recently made great advances in cancer treatment, the
majority of patients diagnosed with pancreatic cancer (PC) cannot achieve satisfactory outcomes
due to intrinsic and acquired radioresistance. Identifying the molecular mechanisms that impair
the efficacy of radiotherapy and targeting these pathways are essential to improve the radiation
response of PC patients. Our goal is to identify sensitive targets for pancreatic cancer radiotherapy
(RT) using the kinome-wide CRISPR-Cas9 loss-of-function screen and enhance the therapeutic
effect through the development and application of targeted inhibitors combined with radiotherapy.
We transduced pancreatic cancer cells with a protein kinase library; 2D and 3D library cells were
irradiated daily with a single dose of up to 2 Gy for 4 weeks for a total of 40 Gy using an X-ray
generator. Sufficient DNA was collected for next-generation deep sequencing to identify candidate
genes. In this study, we identified several cell cycle checkpoint kinases and DNA damage related
kinases in 2D- and 3D-cultivated cells, including DYRK1A, whose loss of function sensitizes cells
to radiotherapy. Additionally, we demonstrated that the harmine-targeted suppression of DYRK1A
used in conjunction with radiotherapy increases DNA double-strand breaks (DSBs) and impairs
homologous repair (HR), resulting in more cancer cell death. Our results support the use of CRISPR-
Cas9 screening to identify new therapeutic targets, develop radiosensitizers, and provide novel
strategies for overcoming the tolerance of pancreatic cancer to radiotherapy.

Real-time respiratory motion management (RRMM, intra-fraction geometrical intervention) and Adaptive Particle Therapy (APT, inter-fraction adaptation of treatment plans) enable to account for anatomical variations and changes to optimize target coverage and organs-at-risk sparing. However, their current clinical implementation is unclear and expected to be highly heterogeneous. An institutional questionnaire, Patterns Of Practice for Adaptive and Real-Time Particle Therapy (POP-ART-PT), was distributed between 2021/01-06 to evaluate current clinical practice and wishes and barriers of the implementation. Here, we summarise the international survey results on APT for mitigation of interfractional anatomical changes from 70 particle therapy centers in 17 countries.

The response rate was 100% for Europe, 96% for Japan and 53% for USA. Of the 68 centers in operation, 84% (Figure1a) were APT users for at least one treatment site, with head and neck being the most common. APT was mostly performed offline (ad-hoc or per protocol) with only two users of online APT (plan library) and none using online daily replanning. Plan adaptation was in all cases motivated by both, target and OAR dose considerations (Figure1b). The most common imaging modality guiding APT was X-ray computed tomography. Sixty-eight percent of users plan to increase or change their APT technique. The greatest barriers to implementation were lack of integrated and efficient workflows and human resources (Figure2)

Offline APT has been widely implemented internationally, but online APT is still very rarely used. More research and development for integrated and efficient workflow is needed to facilitate the use of offline APT and enable online APT.

Retirement Home facilities have been widely affected by the COVID-19 pandemic. The residents in these homes are usually elderly people with a high risk of mortality from being infected. Since they are in contact with each other, once an infection arrives at the facility, it propagates quickly. To prevent the outbreaks, it has been demonstrated that regular testing of the residents is the most practical approach. However, testing may result in extra time for the staff that performs the test as well as residents' discontent, which presents a trade-off between the time invested in testing, daily caring activities, and viral spread containment. We introduce a novel optimization approach for testing schedule strategies in retirement homes. We develop a mixed-integer linear programming model for balancing the staff’s workload while minimizing the expected detection time of a probable infection inside the facility. We present a probabilistic approach in conjunction with the optimization models to compute the risk of infection, including contact rates, incidence status, and the probability of infection of the residents. To tackle the combinatorial nature of the problem, we proved an efficient property, called symmetry property of optimal testing strategy and utilized it in proposing an enhanced local search algorithm. We perform several experiments with real-size instances and show that the proposed approach can derive optimal testing strategies.

Clay rock formations are considered as host rocks for underground radioactive waste repositories. Reliable predictions of diffusive transport heterogeneity are critical for assessing the sealing capacity of argillaceous rocks. The predictive power of numerical approaches to flow field analysis and radionuclide migration depends on the quality of the underlying pore network geometry. Both sedimentary and diagenetic complexity are controlling factors.
In this study, we demonstrate a cross-scale approach to reconstruct the pore network geometries of the sandy facies of the Opalinus Clay rock. We identified diagenetic and sedimentary subfacies components based on the concentration of diagenetic carbonates and sulfides and grain size variability, and quantified their pore size distributions and pore network geometries. A viable approach for use in transport modeling is to combine μ-CT data segmentation followed by filling the resulting volumes with representative pore network geometries based on FIB-SEM data. The resulting generalized pore network geometries are applied in digital rock models to calculate effective diffusivities, using a combined upscaling workflow for transport simulations from nanometer to micrometer scales.
Positron emission tomography (PET) diffusion experiments validated the transport simulation results. We introduced a statistical treatment of the PET and μ-CT tomographic datasets based on the spatial variability of both PET tracer concentrations and rock density. The analyzed effective diffusivities confirmed the numerical results.
This study illustrates three important steps in migration analysis: (i) a workflow of general applicability for cross-scale identification of pore network data in argillaceous rocks, (ii) application of the pore network data for the numerical analysis of diffusive transport, and (iii) validation of numerical results via combined PET - μ-CT diffusion experiments. Although the conceptual approach is not feasible for large numbers of samples, it opens up a strong potential for generalization: the validated results of effective diffusivities can now be easily used in a variety of segmented geometries. This allows to efficiently test upscaling concepts for the continuum scale on this basis.

This paper is associated with a video winner of the 2021 American Physical Society’s Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2021.GFM.V0036.