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Fused 3D boron heterocycles via EnT catalysis: synthesis, modification and validation as beta-lactamase inhibitors
No full textThe installation of a boron unit into bioactive scaffolds continues to unlock novel modes of molecular recognition in drug discovery. As such, de novo strategies to access 3D boron-containing frameworks, that modulate the intrinsic reactivity at boron, are being intensively pursued. Herein, we report a visible light-mediated energy transfer (EnT) catalysis strategy that enables the [2 + 2] cycloaddition of boron-containing heterocycles to construct 3D frameworks with high structural complexity. Leveraging both inter- and intramolecular cycloadditions, a suite of angularly fused boron heterocycles was accessed, offering enhanced steric shielding and modular handles for additional interactions. A boron deletion strategy permits the synthesis of benzofuran scaffolds, otherwise inaccessible via direct EnT. Crucially, the resulting 3D architectures mimic structural motifs found in the potent β-lactamase inhibitor Xeruborbactam. The biological relevance of these frameworks was validated by NMR titration, pKa analysis, and co-crystallisation with serine β-lactamase CTX-M-14, revealing enantiospecific binding and a well-defined hydrogen bonding network. These results establish a versatile platform for the synthesis of functionalised boron heterocycles with direct translational potential in medicinal chemistry
Structural transition and emission enhancement in vacancy-ordered halide double perovskite CsTeCl under pressure
No full textThe effect of pressure on the structural evolution, the enhancement of the photoluminescence intensity, and the optical bandgap of a vacancy-ordered double halide perovskite, Cs2TeCl6, is investigated systematically. We use synchrotron x-ray diffraction, Raman spectroscopy, optical bandgap, and photoluminescence measurements to explore the structural and optical properties of Cs2TeCl6 under pressure up to 30.0 GPa. We find that Cs2TeCl6 undergoes a structural transition from cubic Fm m to monoclinic P21/n at very low pressure below 1.0 GPa. A significant increase in photoluminescence intensity and a rapid decrease in optical bandgap are observed, which are related to the octahedral distortion and structural transition. Interestingly, with increasing pressure, the sample regains its ambient Fm m structure at around 3.4 GPa, maintaining the cubic phase up to 30.0 GPa. The sample undergoes an iso-structural transition at around 14.1 GPa pressure with a slight decrease in compressibility
Programmable Focal Elongation and Shaping of High-Intensity Laser Pulses using Adaptive Optics
No full textControlling the intensity distribution of laser pulses in the focal region is essential for optimizing optically generated plasma waveguides and enabling advanced plasma acceleration techniques, including dephasingless wakefield acceleration. Here, we present a method for programmatic structuring of the high-intensity focal region of a standard off-axis parabolic mirror, extending the length of the focal region well beyond the Rayleigh length and enabling control over the longitudinal intensity distribution. The theoretical framework is validated through numerical simulations and experimental measurements. Further, we demonstrate the use of this technique in an existing plasma accelerator system using readily available hardware components. Finally, we illustrate the potential application of this method to multi-GeV laser plasma acceleration and the generation of flying foci, research areas which would significantly benefit from improved programmatic structuring of high-intensity laser pulses
Synthesis of Gold Hydride at High Pressure and High Temperature
No full textGold is an unreactive metal and its chemical interactions with hydrogen have only recently been explored. Here, we report the formation of gold hydride above 40 GPa and 2200 K in X-ray free electron laser heated diamond anvil cells using various hydrocarbons as hydrogen sources. Above 40 GPa, a hexagonal phase emerges close to the gold melting point, corresponding to a hydride with stoichiometry mathematical equation, with mathematical equation increasing from 0 to near 1 with pressure from 40 to 80 GPa. This is a high-temperature phase which reverts to face centered cubic gold on cooling to 295 K. Accompanying DFT-MD simulations are in excellent agreement with experiment and reveal the structure to consist of an hexagonal close packed gold lattice with atomic hydrogen disordered in the interstices. The hydrogen is superionic and exhibits high diffusivity through the crystalline gold lattice. Our results present the first solid-state binary compound of gold and hydrogen
Modular reactor for in situ X-ray scattering, spectroscopy and ATR-IR studies of solvothermal nanoparticle synthesis
No full textUnderstanding the chemical processes that occur during the solvothermal synthesis of functional nanomaterials is essential for their rational design and optimization for specific applications. However, these processes remain poorly understood, primarily due to the limitations of conventional ex situ characterization techniques and the technical challenges associated with in situ studies, particularly the design and implementation of suitable reactors. Here, we present a versatile reactor suitable for in situ X-ray scattering, X-ray spectroscopy and infrared spectroscopy studies performed during solvothermal synthesis under autoclave-like, inert conditions. The reactor enables precise control of the temperature between −20°C and 200°C, pressure up to 8 bar, magnetic stirring, and injection of gas or liquids. The reactor's capabilities are demonstrated by comprehensively studying the solvothermal synthesis of magnetite nanoparticles from iron acetylacetonate in benzyl alcohol through in situ X-ray scattering and spectroscopy, and attenuated total reflection infrared (ATR-IR) spectroscopy
X-ray Near-Field Holotomography Reconstruction Using Implicit Neural Representations
No full textX-ray near-field holotomography provides non-destructive, in situ 3D visualization of specimen interiors at nanometer-scale resolution.Reconstruction traditionally involves two separate steps: first retrieving the projected phase for different rotation angles, then applying tomographic reconstruction to obtain a 3D volume from 2D projections.Both steps are ill-posed inverse problems and separating them leads to information loss, due to reconstruction errors.Recent advances in implicit neural representations (INRs) have demonstrated remarkable capabilities in scene rendering and tomographic reconstruction.In this work, we propose a unified INR-based framework that jointly solves the phase retrieval and tomographic reconstruction problems.This joint formulation enforces 3D consistency, resulting in significantly improved phase, absorption, and volumetric reconstructions.Moreover, INRs provide substantial data compression.This compression reduces storage requirements by , which is particularly important with the advent of fourth-generation synchrotron sources and the corresponding growth in data volume
Local chemical disorder as the origin of anomalous thermal expansion in TiFe Laves phase alloys
No full textTiFe2 alloys, a C14 Laves phase system, exhibit negative or zero thermal expansion (NTE/ZTE) despite theabsence of the first-order transitions that typically drive such behavior in related compounds. Across thecompositional range, the magnetic ground state evolves from ferromagnetic ordering in Fe-rich alloysto antiferromagnetic ordering in Ti-rich variants, yet the thermal expansion response remains invariant.High-resolution synchrotron X-ray and neutron diffraction detect no anomalies in lattice volume ormagnetic moment, and Rietveld refinements exclude significant antisite disorder. In contrast, Fe and TiK-edge extended X-ray absorption fine structure (EXAFS) and elemental mapping via energy-dispersiveX-ray spectroscopy (EDAX) reveal pronounced nanoscale compositional inhomogeneity, forming Fe-richand Ti-rich regions. The coexistence of competing ferro- and antiferromagnetic interactions from thesechemically distinct domains gives rise to an invar-like effect below a characteristic temperature, T*.These results establish local chemical disorder as a key mechanism for stabilizing NTE/ZTE behavior inintermetallic systems, independent of long-range structural or magnetic transitions
Persistent incommensurate charge density wave in chalcogen-disordered 1-TaSeTe
No full textCharge density waves (CDWs) are a canonical interaction-driven electronic phenomenon with potential technological applications, such as collective electronic switching and local information storage. Here, we investigate the properties of the CDW in the mixed-chalcogen compound 1T-TaSeTe using bulk- and surface-sensitive diffraction and spectroscopy techniques and transport measurements. Compared to the pristine parent compound 1T-TaSe2, we find that the incommensurate CDW appears to remain incommensurate down to low temperatures. The CDW-induced gapping of the Fermi surface is pronounced and may explain the observed semiconductor-like electrical resistivity behavior in combination with chalcogen disorder. Our results demonstrate that disordered chalcogen substitution doping can modify, yet preserve, the characteristic emergent electronic properties of a transition metal dichalcogenide
A Novel Biosensor for Ferrous Iron Developed via CoBiSe: A Computational Method for Rapid Biosensor Design
No full textGenetically encoded biosensors enable the monitoring of metabolite dynamics in living organisms. We present CoBiSe, a computational biosensor design approach using Constraint Network Analysis to identify optimal insertion sites for reporter modules in molecular recognition elements (MREs). Applied to the iron-binding protein DtxR from Corynebacterium glutamicum, CoBiSe identified a flexible connective loop (residues 138–150) for inserting the reporter module, resulting in IronSenseR, a novel ratiometric biosensor for ferrous iron (Fe2+). IronSenseR demonstrates high specificity for Fe2+ with dissociation constants of 1.78 ± 0.03 (FeSO4) and 2.90 ± 0.12 μM (FeCl2), while showing no binding to Fe3+ and other divalent cations. In vivo assessment in Escherichia coli, Pseudomonas putida, and Corynebacterium glutamicum confirmed IronSenseR’s capability to detect changes in the intracellular iron pool. The creation of IronSenseR underlines that by reducing search space and eliminating labor-intensive screening, CoBiSe streamlines biosensor development and enables precise creation of next-generation biosensors for diverse metabolites
Measurements of the inclusive W and Z boson production cross sections and their ratios in proton-proton collisions at TeV
No full textMeasurements are presented of the W and Z boson production cross sections in proton-proton collisions at a center-of-mass energy of 13.6 TeV. Data collected in 2022 and corresponding to an integrated luminosity of 5.01 fb with one or two identified muons in the final state are analyzed. The results for the products of total inclusive cross sections and branching fractions for muonic decays of W and Z bosons are (acceptance) nb for W boson production, (acceptance) nb for W boson production, and (acceptance) nb for the Z boson production in the dimuon mass range of 60–120 GeV, all with negligible statistical uncertainties. Furthermore, the corresponding fiducial cross sections, as well as cross section ratios for both fiducial and total phase space, are provided. The ratios include charge-separated results for W boson production (W and W) and the sum of the two contributions (W), each relative to the measured Z boson production cross section. Additionally, the ratio of the measured cross sections for W and W boson production is reported. All measurements are in agreement with theoretical predictions, calculated at next-to-next-to-leading order accuracy in quantum chromodynamics.[graphic not available: see fulltext