Polymelamine Formaldehyde-Coated MIL-101 as an Efficient Dual-Functional Core-Shell Composite to Catalyze the Deacetalization-Knoevenagel Tandem Reaction.

Porous organic polymer (POP) coated on a metal-organic framework (MOF) has the functions and advantages of MOF and POP at the same time and has excellent catalytic ability. In this study, an efficient dual-functional core-shell composite MOF@POP with Lewis acid and Brønsted base sites was synthesized using the impregnation method in which MIL-101(Cr) was the core component and polymelamine formaldehyde (PMF) was the shell component. Most importantly, the obtained MIL-101(Cr)@PMF showed perfect catalytic activity in the deacetalization-Knoevenagel tandem reaction. In addition, it could still maintain ultrahigh physical and chemical stability.

Expression characteristics of pineal miRNAs at ovine different reproductive stages and the identification of miRNAs targeting the AANAT gene.

BACKGROUND: Many recent studies have shown that miRNAs play important roles in the regulation of animal reproduction, including seasonal reproduction. The pineal gland is a crucial hub in the regulation of seasonal reproduction. However, little is known about the expression characteristics of pineal miRNAs in different reproductive seasons (anestrus and breeding season). Therefore, the expression profiles and regulatory roles of ovine pineal miRNAs were investigated during different reproductive stages using Solexa sequencing technology and dual luciferase reporter assays. RESULTS: A total of 427 miRNAs were identified in the sheep pineal gland. Significant differences in miRNA expression were demonstrated between anestrus and the breeding season in terms of the frequency distributions of miRNA lengths, number of expressed miRNAs, and specifically and highly expressed miRNAs in each reproductive stage. KEGG analysis of the differentially expressed (DE) miRNAs between anestrus and the breeding season indicated that they are significantly enriched in pathways related to protein synthesis, secretion and uptake. Furthermore, transcriptome analysis revealed that many target genes of DE miRNAs in the ribosome pathway showed relatively low expression in the breeding season. On the other hand, analyses combining miRNA-gene expression data with target relationship validation in vitro implied that miR-89 may participate in the negative regulation of aralkylamine N-acetyltransferase (AANAT) mRNA expression by targeting its 3'UTR at a unique binding site. CONCLUSIONS: Our results provide new insights into the expression characteristics of sheep pineal miRNAs at different reproductive stages and into the negative regulatory effects of pineal miRNAs on AANAT mRNA expression.

The 2019 novel coronavirus resource.

An ongoing outbreak of a novel coronavirus infection in Wuhan, China since December 2019 has led to 31,516 infected persons and 638 deaths across 25 countries (till 16:00 on February 7, 2020). The virus causing this pneumonia was then named as the 2019 novel coronavirus (2019-nCoV) by the World Health Organization. To promote the data sharing and make all relevant information of 2019-nCoV publicly available, we construct the 2019 Novel Coronavirus Resource (2019nCoVR, https://bigd.big.ac.cn/ncov). 2019nCoVR features comprehensive integration of genomic and proteomic sequences as well as their metadata information from the Global Initiative on Sharing All Influenza Data, National Center for Biotechnology Information, China National GeneBank, National Microbiology Data Center and China National Center for Bioinformation (CNCB)/National Genomics Data Center (NGDC). It also incorporates a wide range of relevant information including scientific literatures, news, and popular articles for science dissemination, and provides visualization functionalities for genome variation analysis results based on all collected 2019-nCoV strains. Moreover, by linking seamlessly with related databases in CNCB/NGDC, 2019nCoVR offers virus data submission and sharing services for raw sequence reads and assembled sequences. In this report, we provide comprehensive descriptions on data deposition, management, release and utility in 2019nCoVR, laying important foundations in aid of studies on virus classification and origin, genome variation and evolution, fast detection, drug development and pneumonia precision prevention and therapy.

The Different Resistance of Two Astragalus Plants to UV-B Stress is Tightly Associated with the Organ-specific Isoflavone Metabolism.

In this work, the changes in isoflavone levels and the expression of genes involved in their biosynthesis were studied in two Astragalus by UPLC-MS and real-time PCR after 10 days of UV-B treatment (λmax  = 313 nm, 804 J m-2 ). Isoflavones were significantly induced by UV-B irradiation. The influence might be activated by the regulation of these target genes. Our results indicate that (1) the resistance of Astragalus membranaceus might not be as good as Astragalus mongholicus in the enhanced UV-B radiation environment; (2) the enhanced accumulation of calycosin and calycosin-7-glucoside with UV-B treatment in roots of A. mongholicus might be derived from formononetin which is synthesized in the leaves; (3) the glycosylation process could be stimulated and activated by the enhanced UV-B radiation in both A. mongholicus and A. membranaceus. In other words, glycosylation of isoflavones might play a crucial role for two Astragalus plants in response to UV-B stress. Overall, this study offered a feasible elicitation strategy to understand the accumulation pattern of isoflavone in A. mongholicus and A. membranaceus, and also provided a reference for the changes in isoflavone levels of Astragalus in UV-B enhanced environment in the future.

Circulating microRNA-1a is a biomarker of Graves' disease patients with atrial fibrillation.

PURPOSE: It has been increasingly suggested that specific microRNAs expression profiles in the circulation and atrial tissue are associated with the susceptibility to atrial fibrillation. Nonetheless, the role of circulating microRNAs in Graves' disease patients with atrial fibrillation has not yet been well described. The objective of the study was to identify the role of circulating microRNAs as specific biomarkers for the diagnosis of Graves' disease with atrial fibrillation. METHODS: The expression profiles of eight serum microRNAs, which are found to be critical in the pathogenesis of atrial fibrillation, were determined in patients with Graves' disease with or without atrial fibrillation. MicroRNA expression analysis was performed by real-time PCR in normal control subjects (NC; n = 17), patients with Graves' disease without atrial fibrillation (GD; n = 29), patients with Graves' disease with atrial fibrillation (GD + AF; n = 14), and euthyroid patients with atrial fibrillation (AF; n = 22). RESULTS: Three of the eight serum microRNAs,i.e., miR-1a, miR-26a, and miR-133, had significantly different expression profiles among the four groups. Spearman's correlation analysis showed that the relative expression level of miR-1a was positively correlated with free triiodothyronine (FT3) and free thyroxine (FT4), and negatively related to thyroid stimulating hormone. Spearman's correlations analysis also revealed that the level of miR-1a was negatively correlated with a critical echocardiographic parameter (left atrial diameter), which was dramatically increased in GD + AF group compared to GD group. Furthermore, the receiver-operating characteristic curve analysis indicated that, among the eight microRNAs, miR-1a had the largest area under the receiver-operating characteristic curves not only for discriminating between individuals with and without Graves' disease, but also for predicting the presence of atrial fibrillation in patients with Graves' disease. CONCLUSIONS: Our findings showed that the levels of serum miR-1a were significantly decreased in GD + AF group compared with GD group, suggesting that serum miR-1a might serve as a novel biomarker for diagnosis of atrial fibrillation in patients with Graves' disease.

Interlayer charge-transfer in impacting the second hyperpolarizabilities: radical and cation species of hexathiophenalenylium and its nitro dimers.

Hexathiophenalenylium (HTPLY) has gained increasing attention for its interesting and potentially useful optical properties as a result of the enhancement in spin delocalization and charge-transfer of phenalenyl radicals, occasioned by the attachment of successive three disulfide linkages. Herein, we performed density functional theory to calculate the binding interactions, electronic absorption spectra and the second hyperpolarizabilities of cation and radical dimers of HTPLY and its nitro derivatives. It is found that the equilibrium structures of the π dimers at fully staggered position are most stable. Among these π dimers, radical dimers exhibit stronger binding interactions with respect to cation dimers. In addition, obvious red shifts in electronic spectra of radical dimers are dependent on the large interlayer charge-transfers. More importantly, radical dimers [4]dim3 and [5]dim1 exhibit a significant increase in the second hyperpolarizabilities as compared to cation dimers, which is due to lower excitation energies and larger interlayer charge-transfers. We believe that the results presented in this article shall provide important evidence for the large interlayer charge-transfers in enhancing the NLO properties of the π dimers.

[Separation and determination of selenium polysaccharide in enriched-Se cordyceps militaris].

In the present paper, the water soluble selenium polysaccharide was extracted, and isolated and purified preliminarily. The traditional method was used to extract selenium polysaccharide, which was extracted by water and sank by ethanol. The work also focused on the determination of the experiment conditions, optimizing the experiment conditions such as proportion of extract solution, extract temperature, extract times, proportion of ethanol, and standing time. The recovery of selenium polysaccharide under these conditions is 5.76%. Polysaccharide content in the powder is 46.6%, and selenium content is 92.3 mg x kg(-1).

[Determination of active species of heavy metals in sewage sludge by ICP-MS].

Sewage sludge samples for the research from the sewage disposal plants of the north, Mantang River and Xiannu River in Shenyang were extracted and separated by H2O, HAc and organic solvents of different polarities. The active species of Cd, Pb, Cu, Zn and Cr existing in the sewage sludge were determined by ICP-MS, and the regularity and influential factors were studied under the alternation of environmental conditions. The results showed that the content of acid-soluble heavy metals was more than that of water-soluble ones, and both had coincident regularity under the alternation of time and temperature; the content of the organic solvents was positively correlated to the solvent polarity. The acid-soluble heavy metals were more active during the course of transforming, and the activity sequence of heavy metals in the same species was: water-soluble Zn>Cu>Cd> Pb>Cr, acid-soluble Cd>Cr>Cu>Zn>Pb, and organic-soluble Pb>Cd>Cr>Cu>Zn.