Article
Multidisciplinary Sciences
Jonas E. Warias, Franziska Reise, Svenja C. Hoevelmann, Rajendra P. Giri, Michael Roehrl, Jule Kuhn, Malte Jacobsen, Kuntal Chatterjee, Thomas Arnold, Chen Shen, Sven Festersen, Andrea Sartori, Philipp Jordt, Olaf M. Magnussen, Thisbe K. Lindhorst, Bridget M. Murphy
Summary: Following the reaction of biological membranes to external stimuli provides important insights into cellular function. In this study, model membranes composed of self-assembled lipid monolayers containing photoswitchable azobenzene glycolipids were used to investigate the structural response during isomerization. The results demonstrate that azobenzene glycolipids can act as a bidirectional switch in DPPC monolayers, causing reproducible changes in surface pressure and layer thickness, indicating monolayer reorientation and providing a tool to explore membrane structure-function relationships in depth.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
David Marecek, Julian Oberreiter, Andrew Nelson, Stefan Kowarik
Summary: An approach is presented for analyzing real-time X-ray reflectivity (XRR) data as a function of both q and time, using convolutional neural networks and differential evolution fitting. This method allows for accurate analysis of sparsely sampled or noisy XRR data, and enables faster measurements with less beam damage.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2022)
Article
Materials Science, Characterization & Testing
Kyle M. Champley, Trevor M. Willey, Hyojin Kim, Karina Bond, Steven M. Glenn, Jerel A. Smith, Jeffrey S. Kallman, William D. Brown, Isaac M. Seetho, Lionel Keene, Stephen G. Azevedo, Larry D. McMichael, George Overturf, Harry E. Martz
Summary: This paper introduces Livermore Tomography Tools (LTT), a customizable scientific software package for computed tomography (CT) research. LTT is capable of processing various CT data accurately and rapidly, with support for multiple CPUs and GPUs. It offers 88 algorithms for pre-processing, reconstruction, post-processing, and simulation, and supports different scanner geometries. Several applications demonstrate LTT's accuracy, speed, and flexibility compared to other solutions.
NDT & E INTERNATIONAL
(2022)
Article
Computer Science, Artificial Intelligence
Daniil Mironov, James H. Durant, Rebecca Mackenzie, Joshaniel F. K. Cooper
Summary: The neural network-based tool described in the study automatically estimates thin film thicknesses and scattering length densities from neutron reflectivity curves, providing accurate parameter estimation for simple cases and lowering the barrier to data analysis for large scale facility experiments. Transfer learning has also shown that the tool works for x-ray reflectivity, and its code is freely available on GitHub.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Applied
Mingzhen Feng, Nolan J. Ahlm, Alexander M. Kane, I-Ting Chiu, Dayne Y. Sasaki, Padraic Shafer, Alpha T. N'Diaye, Apurva Mehta, Yayoi Takamura
Summary: The magnetic properties and interfacial phenomena of epitaxial perovskite oxide films are highly sensitive to parameters such as film thickness and strain state. In this study, it was found that magnetically active Co2+ ions appeared in the bilayer films under certain conditions, depending on the thickness of the LSCO layer and the substrate material. These findings contribute to the understanding of the interfacial exchange spring behavior and have implications for applications in spintronics and magnetic memory devices.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Armando Maestro, Philipp Gutfreund
Summary: This review paper focuses on the structure and composition of Langmuir monolayers (LMs) at the air/water interface using various experimental techniques. From the first experiment by Angels Pockels in her home kitchen to the present day, LMs of different materials have been extensively studied and are important model systems in biology, physics, and chemistry.
ADVANCES IN COLLOID AND INTERFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Pramod Vishwakarma, Gagan Sharma, M. H. Modi, Mukul Gupta, Jochen Stahn, Ajay Gupta
Summary: The migration of boron in CoFeB/MgO multilayer during the amorphous to crystalline transformation in CoFeB has been investigated using Polarized Neutron Reflectivity (PNR) and anomalous Soft X-ray Reflectivity (SXR). Both PNR and anomalous SXR results indicate that boron tends to move away from the MgO/CoFeB interfaces and forms a boride layer in the middle of the magnetic layer upon thermal annealing. These findings are significant for understanding the role of boron in CoFeB/MgO based magnetic tunnel junctions.
MATERIALS RESEARCH BULLETIN
(2023)
Article
Nanoscience & Nanotechnology
Shuntaro Uenuma, Kimika Endo, Norifumi L. Yamada, Hideaki Yokoyama, Kohzo Ito
Summary: A novel approach using pseudo-polyrotaxane nanosheets (PPRNS) to form polymer brush layers on material surfaces was reported, which showed high adhesion and oil-repellent properties. The flexible PPRNS structure enabled it to adhere well to various surfaces, making it a promising method for improving surface properties across different material types.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Stephanie L. Moffitt, Chuntian Cao, Maikel F. A. M. Van Hest, Laura T. Schelhas, Hans-Georg Steinrueck, Michael F. Toney
Summary: In this study, the existence of vertically heterogeneous thermally induced structural relaxation in amorphous In-Zn-O (a-IZO) thin films was observed using in situ X-ray reflectivity, which has not been previously observed. Thermal annealing was found to influence the electrical performance of the films. These findings are important for the development of a-IZO-based devices.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
T. G. Sanchez, S. Amador-Alvarado, Y. Kumar, D. Ariza-Flores, M. A. Basurto-Pensado, V Agarwal
Summary: A simple chemical method for tuning the optical properties of TiO2 nanoparticles-doped VO2 thin films is reported. Increasing dopant concentration improves the homogeneity of the deposited films, and the optical spectra changes can be used to extract corresponding parameters. Furthermore, temperature-induced variations in the spectra of the doped samples allow for an extended optical operating range.
Article
Chemistry, Multidisciplinary
Sara Ungania, Francesco Maria Solivetti, Marco D'Arienzo, Francesco Quagliani, Isabella Sperduti, Aldo Morrone, Carlo de Mutiis, Vicente Bruzzaniti, Antonino Guerrisi
Summary: This study aimed to assess the image quality of reduced radiation dose CT images reconstructed with the ASiR-V algorithm and investigate the optimization of image quality parameters. The results showed that ASiR-V algorithm can provide high diagnostic quality images while reducing the patient dose. The best agreement was obtained for the images reconstructed using ASiR-V with NI24 and a high blending percentage (70-100%).
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Inorganic & Nuclear
Georgi Popov, Goran Bacic, Charlotte Van Dijck, Laura S. Junkers, Alexander Weiss, Miika Mattinen, Anton Vihervaara, Mykhailo Chundak, Pasi Jalkanen, Kenichiro Mizohata, Markku Leskela, Jason D. Masuda, Sean T. Barry, Mikko Ritala, Marianna Kemell
Summary: Atomic layer deposition (ALD) offers excellent film uniformity and conformality for the deposition of mixed-halide perovskite films. However, ALD is only capable of depositing iodine-based halide perovskites and lacks processes for other halides. In this study, six new low temperature ALD processes for PbCl2 and PbBr2 deposition are described, which are crucial steps for depositing mixed-halide perovskites with ALD.
DALTON TRANSACTIONS
(2022)
Article
Ophthalmology
Kehao Wang, Masato Hoshino, Kentaro Uesugi, Naoto Yagi, Barbara K. Pierscionek, Usha P. Andley
Summary: This study aimed to investigate how cataract-linked mutations affect the gradient refractive index and lens opacity in mouse lenses, as well as the impact of treatment with oxysterol compounds on lens optics. The results showed that mutations altered the refractive index gradient of the lenses and topical treatment with VP1-001 improved lens transparency and refractive index contours in some mutant lenses.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Chemistry, Physical
Anupama Chanda, Shalik Ram Joshi, V. R. Akshay, Shikha Varma, Jai Singh, M. Vasundhara, Prashant Shukla
Summary: The investigation focused on the effects of multilayers and cobalt (Co) doping on the structural and optical properties of TiO2 thin films. The findings showed that Co-doped TiO2 multilayered films exhibited enhanced values of refractive index, transmittance, and blue emission, making them promising for optical device applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Constantin Harder, Alexandros E. Alexakis, Yusuf Bulut, Shuxian Xiong, Benedikt Sochor, Guangjiu Pan, Huaying Zhong, Korneliya Goordeyeva, Manuel A. Reus, Volker Koerstgens, Arno Jeromin, Thomas F. Keller, L. Daniel Soederberg, Eva Malmstroem, Peter Mueller-Buschbaum, Stephan V. Roth
Summary: The authors of this paper investigate the correlation between nanostructure and optical properties of thin hybrid films in order to design sustainable applications. They demonstrate how the refractive index of hybrid cellulose nanofibril/water-dispersed colloidal ink thin films can be manipulated through scalable, layer-by-layer slot-die coating. By studying the different colloidal sizes and their glass transition temperature, they show how post-deposition annealing can alter the colloidal nanostructure and the imbibition of colloids into cellulose nanofibril template.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Instruments & Instrumentation
Andrew Wittmeier, Chiara Cassini, Mareike Toepperwien, Manuela Denz, Johannes Hagemann, Markus Osterhoff, Tim Salditt, Sarah Koester
Summary: X-rays are becoming an important tool for imaging biological cells, offering the ability to visualize subcellular structures with nanometer resolution. By combining different X-ray methods, it is possible to spatially localize and physically characterize specific cellular structures, such as nucleoli and chromatin, in complex biological systems like the cell nucleus.
JOURNAL OF SYNCHROTRON RADIATION
(2021)
Article
Multidisciplinary Sciences
Malte Vassholz, Tim Salditt
Summary: The study demonstrates X-ray generation based on directing spontaneous X-ray emission into waveguide modes. The modal pattern excited is affected by the waveguide structure, impacting emission of characteristic radiation and bremsstrahlung. Harnessing X-ray generation in waveguides can enhance brilliance and directional emission of tabletop X-ray sources, increasing spatial coherence. The gain of emission into waveguide modes is regulated by the quality factor of the waveguide, as shown through the Purcell effect.
Article
Biophysics
Max Scheu, Karlo Komorowski, Chen Shen, Tim Salditt
Summary: This work presents evidence of the formation of transient stalks in aligned multilamellar stacks of lipid membranes, with accompanying anomalous elasticity behavior of the membrane stack.
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Veronica Chappa, Yuliya Smirnova, Karlo Komorowski, Marcus Mueller, Tim Salditt
Summary: This study quantifies the effects of size polydispersity, thermal fluctuations, and membrane asymmetry on small unilamellar vesicles' (SUVs) curved bilayer using simulated Small Angle X-ray Scattering (SAXS) curves. The factorization approximation of the scattering intensity holds even for small vesicle radii, but curvature-induced asymmetry in the electron-density profile can arise for very small vesicles. Thermal fluctuations and size polydispersity have distinguishable signatures in the SAXS intensity, with polydispersity affecting low-q features and thermal fluctuations predominantly affecting scattering at larger q.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2021)
Article
Chemistry, Multidisciplinary
Leon M. Lohse, Malte Vassholz, Tim Salditt
Summary: This paper discusses the experimental realization and contrast formation theory of incoherent diffractive imaging (IDI), as well as explicit expressions for the equal-pulse two-point intensity correlations. The study considers factors such as photon detection statistics, temporal coherence, and scattering volume geometry, analyzing their effects on contrast limitation.
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES
(2021)
Article
Optics
Jakob Soltau, Leon Merten Lohse, Markus Osterhoff, Tim Salditt
Summary: Recent advances in nanofabrication and coherent hard X-ray sources have enabled high-resolution X-ray microscopy using large numerical aperture optics for small focal spot sizes. Multilayer optics like multilayer Laue lenses and zone plates have achieved sub-10 nm and sub-5 nm focal spot sizes. However, their extreme aspect ratio presents challenges for kinematic theory and numerical simulation, hindering further progress in design and utilization. Finite-difference propagation method shows promise for accurately simulating X-ray wavefields within multilayer optics and exploring diffraction effects for achieving small focal spot sizes and high diffraction efficiency.
Article
Multidisciplinary Sciences
Marina Eckermann, Bernhard Schmitzer, Franziska van der Meer, Jonas Franz, Ove Hansen, Christine Stadelmann, Tim Salditt
Summary: By studying the three-dimensional cytoarchitecture of the human hippocampus in healthy and AD individuals, focusing on the nuclear structure of dentate gyrus granule cells, we identified changes in volume and electron density in the nuclei, as well as other structural properties reflecting natural variability and effects associated with AD pathology.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemical Research Methods
Marina Eckermann, Franziska Van der Meer, Peter Cloetens, Torben Ruhwedel, Wiebke Moebius, Christine Stadelmann, Tim Salditt
Summary: This work optimized the experimental parameters of X-ray phase-contrast computed tomography for three-dimensional imaging of the cyto-and myeloarchitecture of the cerebral cortex, demonstrating high-quality imaging and successful assessment of neuropathology in multiple sclerosis.
BIOMEDICAL OPTICS EXPRESS
(2021)
Article
Physics, Multidisciplinary
Jakob Soltau, Markus Osterhoff, Tim Salditt
Summary: This novel approach to x-ray microscopy combines a multilayer zone plate with an iterative phase retrieval scheme to achieve high resolution and quantitative phase contrast.
PHYSICAL REVIEW LETTERS
(2022)
Article
Biophysics
Karlo Komorowski, Julia Preobraschenski, Marcelo Ganzella, Jette Alfken, Charlotte Neuhaus, Reinhard Jahn, Tim Salditt
Summary: The size, polydispersity, and electron density profile of synaptic vesicles can be studied using small-angle X-ray scattering (SAXS). In this study, the authors show that SAXS can also monitor the size and shape transformations of synaptic vesicles in a functional context. They investigated the active uptake of neurotransmitters and found that the vesicle size increased by about 12% after the uptake of glutamate, indicating a high extensibility of the vesicle surface. They propose a new method using single free electron laser pulses to overcome the limitations of heterogeneous structures and assess the spatial distances between vesicle proteins.
EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS
(2022)
Article
Optics
Simon Huhn, Leon Merten Lohse, Jens Lucht, Tim Salditt
Summary: Based on phase retrieval, lensless coherent imaging provides quantitative phase and amplitude images. This study proposes a phase retrieval approach for inline x-ray holography based on Tikhonov regularization, achieving nonlinear, constrained phase retrieval and demonstrating high-quality imaging results.
Article
Biochemical Research Methods
Andrew Wittmeier, Marten Bernhardt, Anna-Lena Robisch, Chiara Cassini, Markus Osterhoff, Tim Salditt, Sarah Koester
Summary: This study explores the use of high-resolution imaging techniques combining hard X-ray propagation-based phase contrast tomography and visible light confocal microscopy to study the structure of DNA in the cell nucleus. This method allows for quantification of nuclear material properties and spatial localization and physical characterization of different types of heterochromatin, euchromatin, pericentric heterochromatin foci, and nucleoli.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Optics
Jakob Soltau, Paul Meyer, Robert Hartmann, Lothar Strueder, Heike Soltau, Tim Salditt
Summary: We propose a full-field x-ray fluorescence imaging approach using a Fresnel zone plate as a coded aperture. The incoherent image formation is identical to the coherent propagation image of an equivalent absorption object. Prior knowledge of the coded aperture structure and position is no longer required, and fast and robust reconstruction algorithms can be applied. This imaging scheme is suitable for further dissemination of x-ray fluorescence imaging and enables full-field imaging of other incoherent radiation processes.
Article
Instruments & Instrumentation
Hendrik Bruns, Hannes Hoeppe, Ewen Bellec, Steven Leake, Markus Osterhoff, Tim Salditt
Summary: A sample environment and manipulation tool for single-particle X-ray experiments in an aqueous environment is introduced. The tool is based on a structured substrate with hydrophobic and hydrophilic patterns to stabilize the position of a single water droplet. The droplet can be covered by a thin film of mineral oil to prevent evaporation and single particles can be probed and manipulated using micropipettes. Experimental challenges and preliminary results are discussed, and future applications in coherent imaging and diffraction experiments are considered.
JOURNAL OF SYNCHROTRON RADIATION
(2023)
Article
Chemistry, Physical
Titus Czajka, Charlotte Neuhaus, Jette Alfken, Moritz Stammer, Yuriy Chushkin, Diego Pontoni, Christian Hoffmann, Dragomir Milovanovic, Tim Salditt
Summary: This study investigates the suitability of passive microrheology based on X-ray photon correlation spectroscopy (XPCS) in studying artificial lipid vesicles exhibiting liquid-liquid phase separation (LLPS) and other heterogeneous biomolecular fluids. By adding highly scattering tracer particles to the solution, valuable information on the dynamics of single vesicles and collective behavior can be obtained. At low CaCl2 concentrations, the correlation functions indicate freely diffusing tracer particles, while at higher concentrations, the relaxation rate shows a nonlinear dependence, suggesting arrested diffusion in percolating vesicle clusters.
EUROPEAN PHYSICAL JOURNAL E
(2023)
