Framework-bound alkoxy groups are well-studied intermediates in zeolite chemistry, but their low stability complicates their spectroscopic study in high-temperature reactions such as alkylation or dealkylation. Taking advantage of the much higher bond strength of Si-O versus C-O, we synthesized trimethylsilylated zeolites by reacting them with phenyltrimethylsilane in a catalytic flow reactor at 648 K. In favorable cases, the reaction accurately titrated the acid sites, and 29Si and 13C MAS NMR spectra of the derivatized catalysts measured at room temperature confirmed the proposed reaction.
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http://dx.doi.org/10.1021/ja034541a | DOI Listing |
Adv Sci (Weinh)
January 2025
Medical 3D Printing Center, Orthopedic Institute, Department of Orthopedic Surgery, The First Affiliated Hospital, School of Basic Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, 215000, China.
Stem cell implantation holds promise for enhancing bone repair, but risks of pathogen transmission and malignant cell transformation should not be ignored. Compared to stem cell implantation, recruitment of endogenous stem cells to injured sites is more critical for in situ bone regeneration. In this study, based on the acidic microenvironment of bone injury, an HG-AA-SDF-1α composite hydrogel with a dual-control intelligent switch function is developed by incorporating stromal cell-derived factor (SDF-1α), arginine carbon dots (Arg-CDs), and calcium ions (Ca) into the oxidized hyaluronic acid/gelatin methacryloyl (HG) hydrogel.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Genome-wide identification of binding profiles for DNA-binding proteins from the limited number of intracellular pathogens in infection studies is crucial for understanding virulence and cellular processes but remains challenging, as the current ChIP-exo is designed for high-input bacterial cells (>1010). Here, we developed an optimized ChIP-mini method, a low-input ChIP-exo utilizing a 5,000-fold reduced number of initial bacterial cells and an analysis pipeline, to identify genome-wide binding dynamics of DNA-binding proteins in host-infected pathogens. Applying ChIP-mini to intracellular Salmonella Typhimurium, we identified 642 and 1,837 binding sites of H-NS and RpoD, respectively, elucidating changes in their binding position and binding intensity during infection.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Genetics, The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Genome graphs, including the recently released draft human pangenome graph, can represent the breadth of genetic diversity and thus transcend the limits of traditional linear reference genomes. However, there are no genome-graph-compatible tools for analyzing whole genome bisulfite sequencing (WGBS) data. To close this gap, we introduce methylGrapher, a tool tailored for accurate DNA methylation analysis by mapping WGBS data to a genome graph.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Genome Sciences, University of Virginia, PO Box 800717, Charlottesville, VA 22908, USA.
Many transcription factors (TFs) have been shown to bind to super-enhancers, forming transcriptional condensates to activate transcription in various cellular systems. However, the genomic and epigenomic determinants of phase-separated transcriptional condensate formation remain poorly understood. Questions regarding which TFs tend to associate with transcriptional condensates and what factors influence their association are largely unanswered.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Ophthalmology, University of North Carolina, 130 Mason Farm Rd, Chapel Hill, NC 27517, USA.
Adeno-associated virus (AAV) inverted terminal repeats (ITRs) induce p53-dependent apoptosis in human embryonic stem cells (hESCs). To interrogate this phenomenon, a synthetic ITR (SynITR), harboring substitutions in putative p53 binding sites was generated and evaluated for vector production and gene delivery. Replication of SynITR flanked transgenic genome was similar compared to wild type (wt) ITR, with a modest increase in vector titers.
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