Electron whirl resonance from the itinerant ferromagnets LaCrGe3 CeCrGe3and PrCrGe3

From Informatic
Jump to navigation Jump to search

Epilepsy is a chronic neurological disorder, characterized by recurrent, spontaneous, and transient seizures, and affects more than 70 million people worldwide. Although two dozen antiepileptic drugs (AEDs) are approved and available in the market, seizures remain poorly controlled in one-third of epileptic patients who are suffering from drug resistance or various adverse effects. Recently, the xanthone skeleton has been regarded as an attractive scaffold for the discovery and development of emerging anticonvulsants. We had isolated several dihydroxanthone derivatives previously, including oliganthin H, oliganthin I, and oliganthin N, whose structures were similar and delicately elucidated by spectrum analysis or X-ray crystallographic data, from extracts of leaves of Garcinia oligantha. These xanthone analogues were evaluated for anticonvulsant activity, and a novel xanthone, oliganthin H, has been identified as a sound and effective natural inhibitor of convulsions in zebrafish in vivo. mTOR activator A preliminary structy of oliganthin H, provide a novel scaffold for further modifications, and highlight the xanthone skeleton as an attractive and reliable resource for the development of emerging AEDs.The deacetylation of a diacetoxytetraindole formed the basis of a first-generation synthetic route toward the alkaloid bisindigotin. However, this conceptually straightforward plan led to unexpected results. Acid-mediated hydrolysis initiated skeletal rearrangement processes that resulted in the formation of two novel heteroaromatic scaffolds, both of which contain nine rings. Upon treating the same diacetoxytetraindole with base followed by a silica-mediated autoxidation, a distinct cascade process occurred, generating another novel scaffold also comprising nine rings. A mechanistic rationale for these observations is provided.We propose a general machine learning-based framework for building an accurate and widely applicable energy functional within the framework of generalized Kohn-Sham density functional theory. To this end, we develop a way of training self-consistent models that are capable of taking large datasets from different systems and different kinds of labels. We demonstrate that the functional that results from this training procedure gives chemically accurate predictions on energy, force, dipole, and electron density for a large class of molecules. It can be continuously improved when more and more data are available.Agrobacterium-mediated transformation is the most commonly used technique for plant genetic engineering. During the transformation, a T-DNA region, which is flanked by the right border (RB) and the left border, is transferred to plant nuclear chromosomes. Simultaneously, a sequence adjacent to the RB on T-DNA is frequently transferred to plant genomes together with the intentionally introduced recombinant DNA. We developed a novel polymerase chain reaction (PCR)-mediated detection method targeting this region. The conserved sequence of the region found in genetically modified (GM) crops is only 25 bp in length. To detect this ultrashort 25 bp sequence near the RB region, we designed a primer set consisting of a 12-base forward primer and a 13-base reverse primer. The predicted band was detected from GM crops by optimizing the PCR conditions. We used lateral flow DNA chromatography for rapid and inexpensive detection. The developed method would be applicable for screening the GM crops generated by Agrobacterium-mediated transformation.N-Glycans are structurally similar to human milk oligosaccharides, the gold standard prebiotics for infants. Bovine milk N-glycans released by endo-β-N-acetylglucosaminidase (EndoBI-1) were shown to have similar prebiotic selectivity as human milk oligosaccharides, explaining the interest for N-glycan recovery for use as prebiotics. Industrial thermal treatments such as high-temperature short-time (HTST) and ultra-high-temperature (UHT) might favor the enzymatic deglycosylation of N-glycans through promoting protein denaturation. We investigated the effects of HTST (72 °C for 15 s) and UHT (135 °C for 3 s) on N-glycan release from bovine colostrum glycoproteins by nonimmobilized and amino-immobilized EndoBI-1. A total of 104 N-glycans including isomers/anomers were identified by high-resolution mass spectrometry. In both EndoBI-1 forms, HTST increased the release of N-glycans; however, the impact of UHT on releasing N-glycans was comparable to the nonthermal treatment. Although the amino-immobilized enzyme similarly released neutral N-glycans as the free form, it released fewer sialylated and fucosylated N-glycans.Four new aromatic polyketides (1-4) were isolated from Penicillium sp. RO-11, obtained from the sediment of a hydrothermal spring in the southwestern region of Saudi Arabia. The new compounds are penipyranicins A-C (1-3), characterized by a 4-methyl-4H-pyran moiety, a structural motif unprecedented among fungal polyketides, and the naphthopyrone derivative isopyrenulin (4). The structures of the new compounds were elucidated on the basis of data from mass spectrometry, 1D and 2D NMR analysis, and comparison between experimental and time-dependent density functional theory-calculated electronic circular dichroism spectra. A plausible biosynthetic pathway connecting penipyranicins and isopyrenulin is proposed. The isolated compounds were active against Gram-positive and Gram-negative bacteria.The selective FeCl3-catalyzed oxidative cross-coupling reaction between phenols and primary, secondary, and tertiary 2-aminonaphthalene derivatives was investigated. The generality of this scalable method provides a sustainable alternative for preparing N,O-biaryl compounds that are widely used as ligands and catalysts. Based on a comprehensive kinetic investigation, a catalytic cycle involving a ternary complex that binds to both the coupling partners and the oxidant during the key oxidative coupling step is postulated. Furthermore, the studies showed that the reaction is regulated by off-cycle acid-base and ligand exchange processes.The synthesis, structure, and thermal stability of the periodate double perovskites A2NaIO6 (A= Ba, Sr, Ca) were investigated in the context of potential application for the immobilization of radioiodine. A combination of X-ray diffraction and neutron diffraction, Raman spectroscopy, and DFT simulations were applied to determine accurate crystal structures of these compounds and understand their relative stability. The compounds were found to exhibit rock-salt ordering of Na and I on the perovskite B-site; Ba2NaIO6 was found to adopt the Fm-3m aristotype structure, whereas Sr2NaIO6 and Ca2NaIO6 adopt the P21/n hettotype structure, characterized by cooperative octahedral tilting. DFT simulations determined the Fm-3m and P21/n structures of Ba2NaIO6 to be energetically degenerate at room temperature, whereas diffraction and spectroscopy data evidence only the presence of the Fm-3m phase at room temperature, which may imply an incipient phase transition for this compound. The periodate double perovskites were found to exhibit remarkable thermal stability, with Ba2NaIO6 only decomposing above 1050 °C in air, which is apparently the highest recorded decomposition temperature so far recorded for any iodine bearing compound.