Attosecond Coherence Time Characterization in Hard X-Ray Free-Electron Laser
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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
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Correlative single-cell hard X-ray computed tomography and X-ray fluorescence imaging
Abstract X-ray computed tomography (XCT) and X-ray fluorescence (XRF) imaging are two non-invasive imaging techniques to study cellular structures and chemical element distributions, respectively. However, correlative X-ray computed tomography and fluorescence imaging for the same cell have yet to be routinely realized due to challenges in sample preparation and X-ray radiation damage. Here we report an integrated experimental and computational workflow for achieving correlative multi-modality X-ray imaging of a single cell. The method consists of the preparation of radiation-resistant single-cell samples using live-cell imaging-assisted chemical fixation and freeze-drying procedures, targeting and labeling cells for correlative XCT and XRF measurement, and computational reconstruction of the correlative and multi-modality images. With XCT, cellular structures including the overall structure and intracellular organelles are visualized, while XRF imaging reveals the distribution of multiple chemical elements within the same cell. Our correlative method demonstrates the feasibility and broad applicability of using X-rays to understand cellular structures and the roles of chemical elements and related proteins in signaling and other biological processes.
59 BASIC BIOLOGICAL SCIENCES↗
A hard permanent magnet through molecular design
Permanent magnets constructed from metal ions and organic linkers using molecular design principles could bring transformative advances in areas such as energy conversion, transportation, and information storage. This comment highlights the recent discovery of a metal-organic magnet ordering at 242 °C, and discusses future research directions and possible applications involving such materials.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
High-resolution neutron spectroscopy using backscattering and neutron spin-echo spectrometers in soft and hard condensed matter
The instruments best suited to performing high-energy-resolution neutron spectroscopy are spin-echo spectrometers and backscattering spectrometers. The development of these experimental techniques dates back almost half a century, and most major neutron scattering facilities operate mature spectrometers of one or both classes. Recent advances in instrumentation and neutron sources are enhancing their performance and expanding their capabilities, with the objective of enabling researchers to tackle new and more complex problems. Finally, in this Technical Review, we assess the current state of the art in high-energy-resolution neutron spectrometers, showcasing their role in the study of nanoscale dynamics in soft and biological materials, as well as disordered magnets.
47 OTHER INSTRUMENTATION↗
Radiative forcing from the 2020 shipping fuel regulation is large but hard to detect
Reduction in aerosol cooling unmasks greenhouse gas warming, exacerbating the rate of future warming. The strict sulfur regulation on shipping fuel implemented in 2020 (IMO2020) presents an opportunity to assess the potential impacts of such emission regulations and the detectability of deliberate aerosol perturbations for climate intervention. Here we employ machine learning to capture cloud natural variability and estimate a radiative forcing of +0.074 ±0.005 W m -2 related to IMO2020 associated with changes in shortwave cloud radiative effect over three low-cloud regions where shipping routes prevail. We find low detectability of the cloud radiative effect of this event, attributed to strong natural variability in cloud albedo and cloud cover. Regionally, detectability is higher for the southeastern Atlantic stratocumulus deck. These results raise concerns that future reductions in aerosol emissions will accelerate warming and that proposed deliberate aerosol perturbations such as marine cloud brightening will need to be substantial in order to overcome the low detectability.
54 ENVIRONMENTAL SCIENCES↗
Electrochemically induced crystallization of amorphous materials in molten MgCl2: boron nitride and hard carbon
A novel and versatile strategy for the amorphous-to-crystalline transformation of boron nitride (BN) with the capability to control the degree of crystallization was developed through an electrochemical pathway using MgCl 2 at low temperature (750 °C). This procedure can be extended to the transformation of amorphous carbon to graphite, which significantly reduces the energy and cost, accelerates the synthesis process and could potentially replace industrial graphite synthesis globally. Therefore, the synthesized graphite exhibits much enhanced electrochemical performance at high charge–discharge rates (5C) compared to commercial synthetic graphite.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Following the in-plane disorder of sodiated hard carbon through operando total scattering
Abstract not provided
Mathiesen, Jette K.↗
Coupled hard–soft spinel ferrite-based core–shell nanoarchitectures: magnetic properties and heating abilities
The heating abilities of bi-magnetic core–shell nanostructures are studied depending on core size, nature of the shell, and shell thickness.
36 MATERIALS SCIENCE↗
New reflections on hard X-ray photon-in/photon-out spectroscopy
Analysis of the electronic structure and local coordination of an element is an important aspect in the study of the chemical and physical properties of materials. This is particularly relevant at the nanoscale where new phases of matter may emerge below a critical size. X-ray emission spectroscopy (XES) at synchrotron radiation sources and free electron lasers has enriched the field of X-ray spectroscopy. Additionally, the spectroscopic techniques derived from the combination of X-ray absorption and emission spectroscopy (XAS–XES), such as resonant inelastic X-ray scattering (RIXS) and high energy resolution fluorescence detected (HERFD) XAS, are an ideal tool for the study of nanomaterials. New installations and beamline upgrades now often include wavelength dispersive instruments for the analysis of the emitted X-rays. With the growing use of XAS–XES, scientists are learning about the possibilities and pitfalls. We discuss some experimental aspects, assess the feasibility of measuring weak fluorescence lines in dilute, radiation sensitive samples, and present new experimental approaches for studying magnetic properties of colloidal nanoparticles directly in the liquid phase.
47 OTHER INSTRUMENTATION↗
HANNA: hard-constraint neural network for consistent activity coefficient prediction
We introduce HANNA, the first hybrid neural network model that strictly complies with all thermodynamic consistency criteria for predicting activity coefficients and outperforms current benchmark methods in terms of accuracy and applicability.
Chemistry↗
Provider Perspectives: Identification and Follow-up of Infants who Are Deaf or Hard of Hearing
Objective Without timely screening, diagnosis, and intervention, hearing loss can cause significant delays in a child's speech, language, social, and emotional development. In 2019, Texas had nearly twice the average rate of loss to follow-up (LFU) or loss to documentation (LTD; i.e., missing documentation of services received) among infants who did not pass their newborn hearing screening compared to the United States overall (51.1 vs. 27.5%). We aimed to identify factors contributing to LFU/LTD among infants who do not pass their newborn hearing screening in Texas. Study Design Data were collected through semistructured qualitative interviews with 56 providers along the hearing care continuum, including hospital newborn hearing screening program staff, audiologists, primary care physicians, and early intervention (EI) program staff located in three rural and urban public health regions in Texas. Following recording and transcription of the interviews, we used qualitative data analysis software to analyze themes using a conventional content analysis approach. Results Frequently cited barriers included problems with family access to care, difficulty contacting patients, problems with communication between providers and referrals, lack of knowledge among providers and parents, and problems using the online reporting system. Providers in rural areas more often mentioned problems with family access to care and contacting families compared to providers in urban areas. Conclusion These findings provide insight into strategies that public health professionals and health care providers can use to work together to help further increase the number of children identified early who may benefit from EI services. Key Points
Obstetrics & Gynecology↗
A large field-of-view high-resolution hard x-ray microscope using polymer optics
Here, we present an effective approach using a matched pair of polymer-based condenser-objective lenses to build a compact full-field X-ray microscope with a high spatial resolution. A unique condenser comprising arrays of high-aspect-ratio prisms with equilateral cross-section is used for uniformly illuminating samples over a large field of view (FoV) from all angles, which match the acceptance of an objective made of interdigitated orthogonal rows of one-dimensional lenses. State-of-the-art Talbot grating interferometry used to characterize these lenses for the first time revealed excellent focusing properties and minimal wave-front distortions. Using a specific lens-pair designed for 20 keV X-rays, short-exposure times, and image registration with a cross-correlation technique, we circumvent vibrational instabilities to obtain distortion-free images with a uniform resolution of 240 nm (smallest resolvable line pair) over a large FoV, 80 × 80 µm 2 in extent. The results were contrasted with those collected under illumination using commercial two-dimensional parabolic lenses with a smaller FoV. This approach implemented on a diffractometer would enable diffraction-contrast or dark-field microscopy for fast observations of ‘mesoscopic’ phenomena in real space complementing reciprocal-space studies using diffraction on the same instrument.
47 OTHER INSTRUMENTATION↗
High resolution x-ray emission spectrometer for multiple hard x-ray emission lines: Demonstration for Cu Kα and Kβ emissions
In this work, we present a compact 3D printed x-ray emission spectrometer based on the von Hamos geometry that represents a significant upgrade to the existing von Hamos geometry-based miniature x-ray emission spectrometer (miniXES). The upgrades include the incorporation of a higher pixel density 500K detector for improved energy resolution and an enlarged sample area to accommodate a wider range of sample formats. The versatile spectrometer houses removable crystal holders that can be easily exchanged, as well as movable alignment eyelets that give flexibility in Bragg angle selection. Designed for ease of manufacture, all the components, except for the apertures, can be 3D printed and readily assembled. We describe its implementation in measurements of resonant and non-resonant Cu Kα and Kβ x-ray emission and report the theoretical and measured energy resolution and collected solid angle of the emission.
3D printing↗
Platform development towards ultra-intense laser-based simultaneous hard X-ray and MeV neutron multimodal radiography
Explore the source record for details and available documents.
Physics - Plasma physics , Lasers, Physics↗
Generation of intense phase-stable femtosecond hard X-ray pulse pairs
Significance The generation of phase-stable femtosecond X-ray pulse pairs will advance nonlinear spectroscopies and imaging, providing direct insight into the coupled motions of electrons and nuclei with resolution on the electronic length scale and timescale. This paper presents the generation of such pulse pairs in the X-ray domain. The approach uses X-ray free-electron laser pulses to induce highly directional, intense, phase-stable pairs of superfluorescence and seeded stimulated emission at the 5.9 keV manganese Kα 1 line. The finding is evidenced by strong interference fringes in the superfluorescence and stimulated emission signals.
43 PARTICLE ACCELERATORS↗
Advances in Operando Electrocatalysis with High-Resolution Hard X-Ray Spectroscopy
Electrocatalysis unfolds at the interface—where solids, liquids, and gases meet to exchange charge, transform molecules, and set the foundation for technologies like CO 2 conversion, and water splitting. These interfacial regions are inherently dynamic, chemically diverse, and structurally heterogeneous. How atoms rearrange, oxidize, coordinate ligands, or adsorb reaction intermediates under electro-chemical potential defines a catalyst’s performance. Furthermore, capturing these changes with element specificity and electronic sensitivity under operando conditions remains one of the most critical challenges in the field.
Garcia-Esparza, Angel T. [SLAC National Accelerato↗