776 research outputs found
1-(4-Chlorophenyl)-3-{5-[(E)-2-phenylethenyl]-1,3,4-thiadiazol-2-yl}urea
In the title compound, C17H13ClN4OS, the 1,3,4-thiadiazole ring makes dihedral angles of 9.70 (15) and 7.22 (10)° with the benzene and phenyl rings, respectively; the dihedral angle between these two rings is 6.37 (19)°. In the crystal, pairs of N—H⋯N and C—H⋯O hydrogen bonds between inversion-related molecules result in supramolecular ribbons displaying alternate R
2
2(8) and R
2
2(14) graph-set ring motifs
Design and analysis of electrothermal metasurfaces
Electrothermal metasurfaces have attracted extensive attention due to their
ability to dynamically control thermal infrared radiation. Although previous
studies were mainly focused on the metasurfaces with infinite unit cells, the
finite-size effect can be a critical design factor for developing thermal
metasurfaces with fast response and broad temperature uniformity in practice.
Here, we study the thermal metasurfaces consisting of gold nanorods with a
finite array size, which, with only several periods, can achieve a resonance
close to that of the infinite case. More importantly, such a small footprint
due to the finite array size results in the response time down to a nanosecond
level. Furthermore, the number of the unit cells in the direction perpendicular
to the axis of the nanorods is found to be insensitive to the resonance and
response time, thus providing a tunability in aspect ratio that can boost the
temperature uniformity in the sub-Kelvin level.Comment: 14 pages, 5 figure
Study on the relationship of acute ketosis intoxication and type 2 diabetes mellitus
AbstractObjectiveTo study the change of serum C-reactive protein (CRP) levels and its correlation with ketosis in type 2 diabetes mellitus patients with acute ketosis intoxication.MethodsA retrospective analysis was conducted for the patients with type 2 diabetes mellitus from August 2015 to January 2016. The patients combined with ketosis were included into diabetic ketosis group and the patients without ketosis were included into negative control group. The clinical data were collected from two groups including general data, blood pressure, liver function and the levels of blood fat, glycosylated hemoglobin, blood ketone, β-hydroxybutyric acid and CRP. The discrepancy of clinical data between two groups was analyzed.ResultsThe levels of glycosylated hemoglobin [(11.6 ± 2.1)% vs. (8.3 ± 1.9)%], blood ketone [0.65 (0.3, 1.75) vs. 0.1 (0.1, 0.2) mmol/L], β-hydroxybutyric acid [0.595 (0.303, 1.775) vs. 0.08 (0.06, 0.15) mmol/L] and CRP [0.595 (0.303, 1.775) vs. 0.08 (0.06, 0.15) mmol/L] were significant higher than those of negative control group, while the levels of blood pressure, blood fat and aminopherase had no significant difference. The serum CRP levels showed positive correlation with blood ketone and β-hydroxybutyric acid (r = 0.490 and r = 0.478, respectively).ConclusionsPoor blood glucose control for a long time and strengthening inflammatory response are correlated with the status of acute ketosis in type 2 diabetes mellitus patients. The CRP levels in ketosis patients were significantly elevated and could be used to evaluate the degree of ketosis
Three new xanthone derivatives from an algicolous isolate of Aspergillus wentii
Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5-dihydroxy-3-methoxy-7-methylanthraquinone (5), and 5-hydroxy-1,3-dimethoxy-7-methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt-1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium.Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5-dihydroxy-3-methoxy-7-methylanthraquinone (5), and 5-hydroxy-1,3-dimethoxy-7-methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt-1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium. Copyright (C) 2012 John Wiley & Sons, Ltd
N6-methyl-adenosine (m6A) in RNA: An Old Modification with A Novel Epigenetic Function
AbstractN6-methyl-adenosine (m6A) is one of the most common and abundant modifications on RNA molecules present in eukaryotes. However, the biological significance of m6A methylation remains largely unknown. Several independent lines of evidence suggest that the dynamic regulation of m6A may have a profound impact on gene expression regulation. The m6A modification is catalyzed by an unidentified methyltransferase complex containing at least one subunit methyltransferase like 3 (METTL3). m6A modification on messenger RNAs (mRNAs) mainly occurs in the exonic regions and 3′-untranslated region (3′-UTR) as revealed by high-throughput m6A-seq. One significant advance in m6A research is the recent discovery of the first two m6A RNA demethylases fat mass and obesity-associated (FTO) gene and ALKBH5, which catalyze m6A demethylation in an α-ketoglutarate (α-KG)- and Fe2+-dependent manner. Recent studies in model organisms demonstrate that METTL3, FTO and ALKBH5 play important roles in many biological processes, ranging from development and metabolism to fertility. Moreover, perturbation of activities of these enzymes leads to the disturbed expression of thousands of genes at the cellular level, implicating a regulatory role of m6A in RNA metabolism. Given the vital roles of DNA and histone methylations in epigenetic regulation of basic life processes in mammals, the dynamic and reversible chemical m6A modification on RNA may also serve as a novel epigenetic marker of profound biological significances
Replication and transcription of human papillomavirus type 58 genome in Saccharomyces cerevisiae
<p>Abstract</p> <p>Background</p> <p>To establish a convenient system for the study of human papillomavirus (HPV), we inserted a <it>Saccharomyces cerevisiae </it>selectable marker, Ura, into HPV58 genome and transformed it into yeast.</p> <p>Results</p> <p>HPV58 genome could replicate extrachromosomally in yeast, with transcription of its early and late genes. However, with mutation of the viral E2 gene, HPV58 genome lost its mitotic stability, and the transcription levels of E6 and E7 genes were upregulated.</p> <p>Conclusions</p> <p>E2 protein could participate in viral genome maintenance, replication and transcription regulation. This yeast model could be used for the study of certain aspects of HPV life cycle.</p
Erzhi Pill® Repairs Experimental Liver Injury via TSC/mTOR Signaling Pathway Inhibiting Excessive Apoptosis
The present study aimed to investigate the mechanism of hepatoprotective effect of Erzhi Pill (EZP) on the liver injury via observing TSC/mTOR signaling pathway activation. The experimental liver injury was induced by 2-acetylaminofluorene (2-AAF) treatment combined with partial hepatectomy (PH). EZP treated 2-AAF/PH-induced liver injury by the therapeutic and prophylactic administration. After the administration of EZP, the activities of aspartic transaminase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AKP), and gamma-glutamyl transpeptidase (γ-GT) were decreased, followed by the decreased levels of hepatocyte apoptosis and caspase-3 expression. However, the secretion of albumin, liver weight, and index of liver weight were elevated. Microscopic examination showed that EZP restored pathological liver injury. Meanwhile, Rheb and mammalian target of rapamycin (mTOR) activation were suppressed, and tuberous sclerosis complex (TSC) expression was elevated in liver tissues induced by 2-AAF/PHx and accompanied with lower-expression of Bax, Notch1, p70S6K, and 4E-EIF and upregulated levels of Bcl-2 and Cyclin D. Hepatoprotective effect of EZP was possibly realized via inhibiting TSC/mTOR signaling pathway to suppress excessive apoptosis of hepatocyte
Antimicrobial peptaibols, novel suppressors of tumor cells, targeted calcium-mediated apoptosis and autophagy in human hepatocellular carcinoma cells
<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is one of the most common cancers in the world which is highly chemoresistant to currently available chemotherapeutic agents. Thus, novel therapeutic targets are needed to be sought for the successful treatment of HCC. Peptaibols, a family of peptides synthesized non-ribosomally by the <it>Trichoderma </it>species and other fungi, exhibit antibiotic activities against bacteria and fungi. Few studies recently showed that peptaibols exerted cytotoxicity toward human lung epithelial and breast carcinoma cells. However, the mechanism involved in peptaibol-induced cell death remains poorly understood.</p> <p>Results</p> <p>Here, we showed that Trichokonin VI (TK VI), a peptaibol from <it>Trichoderma pseudokoningii </it>SMF2, induced growth inhibition of HCC cells in a dose-dependent manner. It did not obviously impair the viability of normal liver cells at lower concentration. Moreover, the suppression of cell viability resulted from the programmed cell death (PCD) with characteristics of apoptosis and autophagy. An influx of Ca<sup>2+ </sup>triggered the activation of μ-calpain and proceeded to the translocation of Bax to mitochondria and subsequent promotion of apoptosis. On the other hand, typically morphological characteristics consistent with autophagy were also observed by punctate distribution of MDC staining and the induction of LC3-II, including extensive autophagic vacuolization and enclosure of cell organelles by these autophagosomes. More significantly, specific depletion of Bak expression by small RNA interfering (siRNA) could partly attenuate TK VI-induced autophagy. However, siRNA against Bax led to increased autophagy.</p> <p>Conclusion</p> <p>Taken together, these findings showed for the first time that peptaibols were novel regulators involved in both apoptosis and autophagy, suggesting that the class of peptaibols might serve as potential suppressors of tumor cells.</p
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