There are more than 100 beamlines or endstations worldwide that frequently support X-ray absorption fine-structure (XAFS) measurements, thus providing critical enabling capability for research across numerous scientific disciplines. However, the absence of a supporting tier of more readily accessible, lower-performing options has caused systemic inefficiencies, resulting in high oversubscription and the omission of many scientifically and socially valuable XAFS applications that are incompatible with the synchrotron facility access model. To this end, this work describes the design, performance and uses of the Clean Energy Institute X-ray absorption near-edge structure (CEI-XANES) laboratory spectrometer and its use as both a user-present and mail-in facility. Such new additions to the XAFS infrastructure landscape raise important questions about the most productive interactions between synchrotron radiation and laboratory-based capabilities; this can be discussed in the framework of five categories, only one of which is competitive. The categories include independent operation on independent problems, use dictated by convenience, pre-synchrotron preparatory use of laboratory capability, post-synchrotron follow-up use of laboratory capability, and parallel use of both synchrotron radiation and laboratory systems.
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http://dx.doi.org/10.1107/S1600577519012839 | DOI Listing |
Acc Chem Res
January 2025
The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K.
ConspectusThe discovery of reversible hydrogenation using metal-free phosphoborate species in 2006 marked the official advent of frustrated Lewis pair (FLP) chemistry. This breakthrough revolutionized homogeneous catalysis approaches and paved the way for innovative catalytic strategies. The unique reactivity of FLPs is attributed to the Lewis base (LB) and Lewis acid (LA) sites either in spatial separation or in equilibrium, which actively react with molecules.
View Article and Find Full Text PDFRadiology
January 2025
From the Department of Radiology, The Third Affiliated Hospital of Southern Medical University (Academy of Orthopedics, Guangdong Province), Guangzhou, China (W.L., L.S., R.Z., Y.Z.); and Medical Research Center, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Zhongshan 2nd Rd, Yuexiu District, Guangzhou 510000, People's Republic of China (J.L., H.L., X.Z., F.X., T.S., K.L., L.N.).
Background Photoacoustic microscopy (PAM) can be used to detect strong absorption from endogenous and exogenous contrast material, making it promising for detailed structural and functional imaging of hepatic sinusoids, including dynamic visualization of permeability. Purpose To evaluate whether PAM-based quantitative parameters of liver function and integrity (lacunarity, blood oxygen saturation [Sao], and Evans blue [EB] permeability) are associated with histopathologic indexes of fibrosis in a mouse model. Materials and Methods Between October 2022 and July 2023, a total of 35 male C57BL/6 mice were included in this study and received intraperitoneal injection of carbon tetrachloride to establish mouse models of progressive liver fibrosis, with seven mice in each group.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
August 2024
Frequency-domain near-infrared spectroscopy (FD-NIRS) is a noninvasive method for quantitatively measuring optical absorption and scattering in tissue. This study introduces structured interrogation (SI) as an interference-based approach for implementing FD-NIRS in order to enhance optical property estimation in multilayered tissues and sensitivity to deeper layers. We find that, in the presence of realistic noise, SI accurately estimates properties and chromophore concentrations with less than a 5% error.
View Article and Find Full Text PDFBiopolymers
March 2025
Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, College of Chemistry and Materials, Nanning Normal University, Nanning, People's Republic of China.
The crosslinked porous corn starch was prepared by two steps: the native corn starch was hydrolyzed by α-amylase and glucoamylase, then the porous corn was crosslinked by sodium trimetaphosphate (STMP). The morphology and size of granules, spherulites, crystal type, molecular structure, swelling properties, thermal stability and adsorption properties of the crosslinked porous starch were investigated. The results indicated that a lot of holes formed in the porous starch, and the particle size of starch granules decreased.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.
X-ray absorption spectroscopy (XAS) is a powerful method for exploring molecular electronic structure by exciting core electrons into higher unoccupied molecular orbitals. In this study, we present the first integration of the spin-unrestricted similarity-transformed equation-of-motion coupled cluster method (CVS-USTEOM-CCSD) for core-excited and core-ionized states into the ORCA quantum chemistry package. Using the core-valence separation (CVS) approach, we evaluate the accuracy of CVS-USTEOM-CCSD across 13 open-shell organic systems, covering over 20 core excitations with diverse spin multiplicities (doublet, triplet, and quartet).
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