Recently, we realized the highly selective one-pot synthesis of 2,6-diarylpyridines by using a Pd-catalyzed direct C-H arylation approach via a transient activator strategy. Although methylation reagent as a transient activator and Cu(I) salt or oxide were found to be prerequisites, details regarding the mechanism remained unclear. In this paper, DFT calculations combined with experimental investigations were carried out to elucidate the principle features of this transformation. The results reveal (1) the origin of the exquisite diarylating selectivity of the pyridine under the transient strategy; (2) the possible demethylating reagent as the counteranion of the pyridinium salt; (3) the reason why CuO is a better Cu(I) resource than others.
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http://dx.doi.org/10.1021/acs.joc.8b01480 | DOI Listing |
Programmed cell death (apoptosis) is essential part of the process of tissue regeneration that also plays role in the mechanism of pathology. The phenomenon of fast and transient permeability of mitochondrial membranes by various triggers, known as permeability transition pore (mPTP) leads to the release of proapoptotic proteins and acts as an initial step in initiation of apoptosis. However, a role for mPTP was also suggested for physiology and it is unclear if there is a threshold in number of mitochondria with mPTP which induces cell death and how this mechanism is regulated in different tissues.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Physics & Chemistry, DGIST Daegu 42988 Korea
Metal-organic frameworks (MOFs), characterized by dynamic metal-ligand coordination bonding, have pivotal roles in catalysis, gas storage, and separation processes, owing to their open metal sites (OMSs). These sites, however, are frequently occupied by Lewis-base solvent molecules, necessitating activation to expose the OMSs for practical applications. Traditional thermal activation methods involve harsh conditions, risking structural integrity.
View Article and Find Full Text PDFFront Immunol
December 2024
Norwegian College of Fishery Science, Faculty of Bioscience, Fisheries and Economics, University of Tromsø - The Arctic University of Norway, Tromsø, Norway.
Non-classical MHC class I genes which, compared to classical MHC class I, are typically less polymorphic and have more restricted expression patterns are attracting interest because of their potential to regulate immune responses to various pathogens. In salmonids, among the numerous non-classical MHC class I genes identified to date, L lineage genes, including Sasa- and , are differentially induced in response to microbial challenges. In the present study, we show that while transcription of both and are induced in response to SAV3 infection the transcriptional induction patterns are distinct for each gene.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran 1458889694, Iran.
We present a novel approach for enhancing photocatalytic efficiency by developing polyaniline (PANI) and polyindole (PIN)-coated TiO nanotubes (TNT) through a combination of chemical oxidation and hydrothermal processes. The PANI-PIN coating was systematically applied to both the internal and external surfaces of the nanotubes to enhance the photocatalytic active sites and optimize pollutant adsorption. The dual-coated structure enhances the interaction with pollutants, facilitating a more efficient degradation of 4-nitrophenol (4-NP) when exposed to visible light.
View Article and Find Full Text PDFMicroPubl Biol
December 2024
Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
Macrophages are present in various forms throughout metazoans and play conserved roles in phagocytosis, immunity, and tissue homeostasis. In s larval hematopoietic organ, the lymph gland, transient caspase-mediated activation of caspase-activated DNase triggers the DNA damage response (DDR), which is crucial for macrophage-type cell differentiation. Here, we report that other species having different-sized mature lymph glands show effector caspase activity and DDR similar to those in , indicating that the developmental mechanism regulating phagocytic macrophage differentiation is conserved in different species of .
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