Besides inorganic constituents, renal stones contain organic matter known as stone matrix. We have examined such matrix obtained from stones that had been crushed by extracorporeal shock-wave lithotripsy, in order to determine its chemical properties. Morphologically, the matrix was composed of fibers of different colors, most of them exhibiting autofluorescence. Proteins or any other well-known biochemical material were not present. It was remarkably stable against chemical degradation, and could not be dissolved in hot concentrated acids or bases or any common organic solvent. Elementary analysis revealed carbon (60.8%), oxygen (26.9%), nitrogen (7.6%), hydrogen (5.3%) and sulfur (0.77%) to be present. Furthermore, X-ray emission spectroscopy revealed the presence of titanium and chromium. Solid-phase 13C NMR spectroscopy revealed the presence of aromatic and aliphatic carbon as well as carbon bound to O and/or N. The material was paramagnetic. All findings indicated the matrix to be composed of a new class of organic compound, probably a polyaromatic heterocyclic organic material. We welcome suggestions on further methods that can ultimately elucidate the nature of lithofibrins.
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http://dx.doi.org/10.3891/acta.chem.scand.50-0633 | DOI Listing |
J Am Chem Soc
January 2025
National Center for Nanoscience and Technology, No. 11 ZhongGuanCun BeiYiTiao, Beijing 100190, China.
The development of highly active and stable cathodes in alkaline solutions is crucial for promoting the commercialization of anion exchange membrane (AEM) electrolyzers, yet it remains a significant challenge. Herein, we synthesized atomically dispersed CoP moieties (CoP-SSC) immobilized on ultrathin carbon nanosheets via a phosphidation exfoliation strategy at medium temperature. The thermodynamic formation process of the Co-P moieties was elucidated using X-ray absorption spectroscopy (XAS) and theoretical calculations.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Fire Science, University of Science and Technology of China, 443 Huangshan Road, Hefei 230027, P. R.China.
The next generation of stretchable electronics seeks to integrate superior mechanical properties with sustainability and sensing stability. Ionically conductive and liquid-free elastomers have gained recognition as promising candidates, addressing the challenges of evaporation and leakage in gel-based conductors. In this study, a sustainable polymeric deep eutectic system is synergistically integrated with amino-terminated hyperbranched polyamide-modified fibers and aluminum ions, forming a conductive supramolecular network with significant improvements in mechanical performance.
View Article and Find Full Text PDFChemphyschem
January 2025
Shanxi University, Institute of Molecular Science, CHINA.
Delocalized multicenter bonds play a crucial role in clusters with a planar hypercoordinate center(s), making it difficult for highly electronegative elements, especially halogen atoms, to achieve the planar hypercoordinate arrangement. Herein, we introduce a star-like cluster Br6Li5-, whose global minimum contains a planar pentacoordinate bromine (ppBr). In this cluster, the central ppBr atom coordinates with five alkali metal Li atoms, which in turn bridge an equal number of electronegative Br atoms in the periphery, leading to the formation of the binary cluster Br6Li5-.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Chemical and Metallurgical Engineering, School of Chemical Engineering, Aalto University, 02150 Espoo, Finland.
Alginate hydrogels have gathered significant attention in biomedical engineering due to their remarkable biocompatibility, biodegradability, and ability to encapsulate cells and bioactive molecules, but much less has been reported on the kinetics of gelation. Scarce experimental data are available on cross-linked alginates (AL) with bioactive components. The present study addressed a novel method for defining the crosslinking mechanism using rheological measurements for aqueous mixtures of AL and calcium chloride (CaCl) with the presence of hydroxyapatite (HAp) as filler particles.
View Article and Find Full Text PDFBiomedicines
December 2024
Department of Cardiology, West China Hospital, Sichuan University, Chengdu 610041, China.
Coronary obstruction following plaque rupture is a critical pathophysiological change in the progression of stable angina (SAP) to acute coronary syndrome (ACS). The accumulation of platelets and various inflammatory cells on apoptotic endothelial cells is a key factor in arterial obstruction after plaque rupture. Through single-cell sequencing analysis (scRNA-seq) of plaques from SAP and ACS patients, we identified significant changes in the annexin V and P-selectin glycoprotein ligand 1 pathways.
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