2,5-Dihydroxyterephthalic acid (H) is well-known for its use in the construction of functional metal-organic frameworks (MOFs). Among them, simple coordination polymers (CPs), such as lithium and sodium coordination polymers with H, have been used successfully to synthesize electrically conductive MOFs and have also demonstrated great potential as positive or negative electrode materials on their own. However, there has been little exploration of the structure and physicochemical properties of these and other alkali complexes of H.
View Article and Find Full Text PDFA significant challenge for chimeric antigen receptor (CAR) T cell therapy against glioblastoma (GBM) is its immunosuppressive microenvironment, which is densely populated by protumoral glioma-associated microglia and macrophages (GAMs). Myeloid immune checkpoint therapy targeting the CD47-signal regulatory protein alpha (SIRPα) axis induces GAM phagocytic function, but CD47 blockade monotherapy is associated with toxicity and low bioavailability in solid tumors. In this work, we engineer a CAR T cell against epidermal growth factor receptor variant III (EGFRvIII), constitutively secreting a signal regulatory protein gamma-related protein (SGRP) with high affinity to CD47.
View Article and Find Full Text PDFThis study reports the synthesis and crystal structure determination of a novel CrTe phase using various experimental and theoretical methods. The average stoichiometry and local phase separation of this quenched high-pressure phase were characterized by synchrotron powder X-ray diffraction and total scattering. Several structural models were obtained using simulated annealing, but all suffered from an imperfect Rietveld refinement, especially at higher diffraction angles.
View Article and Find Full Text PDFIn antiquity, Pb was a common element added in the production of large bronze artifacts, especially large statues, to impart fluidity to the casting process. As Pb does not form a solid solution with pure Cu or with the Sn-Cu alloy phases, it is normally observed in the metal matrix as globular droplets embedded within or in interstitial positions among the crystals of Sn-bronze (normally the α phase) as the last crystallizing phase during the cooling process of the Cu-Sn-Pb ternary melt. The disequilibrium Sn content of the Pb droplets has recently been suggested as a viable parameter to detect modern materials [Shilstein, Berner, Feldman, Shalev & Rosenberg (2019).
View Article and Find Full Text PDFWe show that the non-canonical nucleobase 2,6-diaminopurine (D) spontaneously base pairs with uracil (U) in water and the solid state without the need to be attached to the ribose-phosphate backbone. Depending on the reaction conditions, D and U assemble in thermodynamically stable hydrated and anhydrated D-U base-paired cocrystals. Under UV irradiation, an aqueous solution of D-U base-pair undergoes photochemical degradation, while a pure aqueous solution of U does not.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
June 2024
SnGeNO was synthesized at high pressure (16 and 20 GPa) and high temperature (1200 and 1500°C) in a large-volume press. Powder X-ray diffraction experiments using synchrotron radiation indicate that the derived samples are mixtures of known and unknown phases. However, the powder X-ray diffraction patterns are not sufficient for structural characterization.
View Article and Find Full Text PDFBackground: Arthroscopic rotator cuff repair (ARCR) is among the most commonly performed orthopaedic procedures. Several factors-including age, sex, and tear severity-have been identified as predictors for outcome after repair. The influence of the tear etiology on functional and structural outcome remains controversial.
View Article and Find Full Text PDFThe "in situ electrolyte" displays a concept for electric double-layer- as well as metal-ion capacitors in which the by-products formed during carbon synthesis serve directly as electrolyte salt to minimize waste. In this work, the concept is applied for lithium- and sodium-based systems realizing EDLCs containing aqueous, "Water in Salt" (up to 1.8 V) as well as organic (2.
View Article and Find Full Text PDFA plug-flow fixed-bed cell for synchrotron powder X-ray diffraction (PXRD) and X-ray absorption fine structure (XAFS) idoneous for the study of heterogeneous catalysts at high temperature, pressure and under gas flow is designed, constructed and demonstrated. The operating conditions up to 1000°C and 50 bar are ensured by a set of mass flow controllers, pressure regulators and two infra-red lamps that constitute a robust and ultra-fast heating and cooling method. The performance of the system and cell for carbon dioxide hydrogenation reactions under specified temperatures, gas flows and pressures is demonstrated both for PXRD and XAFS at the P02.
View Article and Find Full Text PDFIn pursuit of accessible and interpretable methods for direct and real-time observation of mechanochemical reactions, we demonstrate a tandem spectroscopic method for monitoring of ball-milling transformations combining fluorescence emission and Raman spectroscopy, accompanied by high-level molecular and periodic density-functional theory (DFT) calculations, including periodic time-dependent (TD-DFT) modelling of solid-state fluorescence spectra. This proof-of-principle report presents this readily accessible dual-spectroscopy technique as capable of observing changes to the supramolecular structure of the model pharmaceutical system indometacin during mechanochemical polymorph transformation and cocrystallisation. The observed time-resolved spectroscopic and kinetic data are supported by X-ray diffraction and solid-state nuclear magnetic resonance spectroscopy measurements.
View Article and Find Full Text PDFComplex functional materials play a crucial role in a broad range of energy-related applications and in general for materials science. Revealing the structural mechanisms is challenging due to highly correlated coexisting phases and microstructures, especially for or investigations. Since the grain sizes influence the properties, these microstructural features further complicate investigations at synchrotrons due to the limitations of illuminated sample volumes.
View Article and Find Full Text PDFGlasses, unlike crystals, are intrinsically brittle due to the absence of microstructure-controlled toughening, creating fundamental constraints for their technological applications. Consequently, strategies for toughening glasses without compromising their other advantageous properties have been long sought after but elusive. Here we report exceptional toughening in oxide glasses via paracrystallization, using aluminosilicate glass as an example.
View Article and Find Full Text PDFWe report the experimental discovery of a new structural phase of well-known orthorhombic BaCuO ( = Sm and Eu), exhibiting a tetragonal crystal structure with space group . The high-pressure tetragonal phase is isostructural with the brown phase BaCuO ( = La, Pr, and Nd). In this structure, the Cu ions form an isolated square planar environment, contrary to the orthorhombic phase, where the Cu ions are located in a distorted square pyramid.
View Article and Find Full Text PDFPurpose: Hemorrhagic stroke, particularly occurring from ruptured cerebrovascular malformations, is responsible for 5-12% of all maternal deaths during pregnancy and the puerperium. Whether endovascular treatment is feasible and safe for both the mother and the fetus, is still a matter of debate. The main objective of this case series and systematic review was to share our multi-institutional experience and to assess the feasibility and safety of endovascular treatment during pregnancy, as well as the corresponding maternal and fetal outcomes based on currently available evidence.
View Article and Find Full Text PDFThe outstanding diversity of Zr-based frameworks is inherently linked to the variable coordination geometry of Zr-oxo clusters and the conformational flexibility of the linker, both of which allow for different framework topologies based on the same linker-cluster combination. In addition, intrinsic structural disorder provides a largely unexplored handle to further expand the accessibility of novel metal-organic framework (MOF) structures that can be formed. In this work, we report the concomitant synthesis of three topologically different MOFs based on the same MO(OH) clusters (M = Zr or Hf) and methane-tetrakis(-biphenyl-carboxylate) (MTBC) linkers.
View Article and Find Full Text PDFUtilizing direct mechanocatalytical conditions, the Sonogashira coupling was successfully performed on the surface of milling tools by using pure Pd and Pd coated steel balls. The optimization of co-catalyst forming additives led to a protocol, which generates quantitative yields under aerobic conditions for various substrates within as little as 90 minutes. Using state-of-the-art spectroscopic, diffractive, as well as in situ methods lead to the identification of a previously unknown and highly reactive complex of the co-catalyst copper.
View Article and Find Full Text PDFControlled synthesis of phase-pure metal-organic frameworks (MOFs) is essential for their application in technological areas such as catalysis or gas sorption. Yet, knowledge of their phase formation and growth remain rather limited, particularly with respect to species such as water whose vital role in MOF synthesis is often neglected. As a consequence, synthetic protocols often lack reproducibility when multiple MOFs can form from the same metal source and linker, and phase mixtures are obtained with little or no control over their composition.
View Article and Find Full Text PDFPhys Chem Chem Phys
February 2023
The high stability, high availability, and wide size-dependent bandgap energy of sulphidic semiconductor nanoparticles (NPs) render them promising for applications in optoelectronic devices and solar cells. However, the tunability of their optical properties depends on the strict control of their crystal structure and crystallisation process. Herein, we studied the structural evolution during the formation of CdS and ZnS in solution by combining luminescence spectroscopy, synchrotron-based X-ray diffraction (XRD) and pair distribution function (PDF) analyses for the first time.
View Article and Find Full Text PDFBackground: Injuries of the long head of the biceps (LHB) tendon are a prevalent source of anterior shoulder pain and are commonly treated with tenodesis. Not only a stable fixation of the LHB but also anatomic restoration of the length-tension relationship plays a central role in providing satisfactory functional and cosmetic outcomes, especially in young patients. We report the clinical outcomes of 2 different subpectoral tenodesis techniques using unicortical button fixation.
View Article and Find Full Text PDFDespite the importance of layered double hydroxides (LDHs) in catalysis, medicine and water treatment, the crystallisation process of these materials is seldom investigated. In this study, characterisation techniques granted unprecedented experimental access to the formation dynamics of carbonate-intercalated Mg/Al LDHs as model system when applying the most relevant co-precipitation approaches by exploring the effects of temperature and concentration of reactants. For this purpose, a combinatorial multi-modal characterisation approach was applied involving measurements of pH, ion conductivity and light scattering, as well as synchrotron-based X-ray diffraction (XRD).
View Article and Find Full Text PDFGrowing evidence links COVID-19 with acute and long-term neurological dysfunction. However, the pathophysiological mechanisms resulting in central nervous system involvement remain unclear, posing both diagnostic and therapeutic challenges. Here we show outcomes of a cross-sectional clinical study (NCT04472013) including clinical and imaging data and corresponding multidimensional characterization of immune mediators in the cerebrospinal fluid (CSF) and plasma of patients belonging to different Neuro-COVID severity classes.
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