Two quantum chemical models have been derived for the prediction of 13C NMR chemical shifts of novel PCB acids obtained from PCBs by catalytic carbonylation. 13C isotropic shielding constants were calculated employing the GIAO (gauge-independent atomic orbital) method with density functional theory (DFT). The best results were obtained by cluster calculations, which took the solvent effects into account properly. In this approach, a solvent molecule (acetone) was attached by a hydrogen bond to every hydrogen atom present in a PCB acid, and the geometry of the molecular cluster was optimized employing the AM1 method. For 158 chemical shifts, the cross-validated standard error was 2.8 ppm and the cross-validated correlation coefficient was 0.94.
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http://dx.doi.org/10.1016/j.chemosphere.2005.04.105 | DOI Listing |
Exp Hematol Oncol
January 2025
Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore.
Background: Radiotherapy is the primary treatment modality for most head and neck cancers (HNCs). Despite the addition of chemotherapy to radiotherapy to enhance its tumoricidal effects, almost a third of HNC patients suffer from locoregional relapses. Salvage therapy options for such recurrences are limited and often suboptimal, partly owing to divergent tumor and microenvironmental factors underpinning radioresistance.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Department of Radiology, Changhai Hospital, Naval Medical University, Changhai Road 168, Shanghai 200433, China. Electronic address:
Background: Lysosomes, as an indispensable subcellular organelle have numerous physiological functions closely associated with HS and viscosity, and accurate assessment of HS/viscosity fluctuations in lysosomes is essential for gaining a comprehensive understanding of lysosome-related physiological activities and pathological processes. The previous single-response fluorescent probes for either HS or viscosity alone have the potential to generate "false positive" signals in a complex biological environment. In contrast, dual-locked probes can simultaneously respond to multiple targets simultaneously, which could effectively eliminate this defect.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Department of Biology, College of Science, Mathematics and Technology, Wenzhou-Kean University, Wenzhou, China; School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address:
Understanding the impact of different soil amendments on microbial communities and antibiotic resistance genes (ARGs) dissemination is crucial for optimizing agricultural practices and mitigating environmental risks. This study investigated the effects of different fertilizer regimes and biochar on plant-associated bacterial communities and ARGs dissemination. The biochar's structural and chemical characteristics were characterized using scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy, revealing a porous architecture with diverse functional groups.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemical and Biological Engineering, University of Saskatchewan, 57 Campus Drive, Saskatoon, SK S7N 5A9, Canada. Electronic address:
This study explores the effect of sucrose addition on the properties of chiral nematic cellulose nanocrystal (CNC) films for potential food industry applications, including biodegradable packaging and food coloring. The addition of sucrose altered the films' structural color, shifting from blue in pure CNC films to aqua blue, green, yellow-green, and red with increasing sucrose concentrations (up to 21 %). Surface analysis revealed a reduction in contact angle from 96° to 48° due to sucrose's hydrophilic nature and smoother film surfaces.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China. Electronic address:
Triclocarban (TCC) and triclosan (TCS) are applied in a wide range of pharmaceutical and personal care products to prevent or reduce bacterial growth. Due to their extensive application, they are frequently detected in marine environments. In this study, marine sediment systems exposed to different concentrations of TCC and TCS were established to evaluate their effects on microbial communities.
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