Arborinol methyl ether from Areca catechu L.

The title compound isolated from Areca catechu L. (common name: arborinol methyl ether; a member of the arborane family) was established as 3α-methoxyarbor-9(11)-ene, C31H52O. Rings A/B/C/D assume a chair conformation, while ring E has an envelope conformation. The absolute configuration was determined to be (3R,5R,8S,10S,13R,14S,17S,18S, 21S) by analysis of Bijvoet pairs based on resonant scattering of light atoms, yielding a Hooft parameter y of −0.03 (3)

Incommensurate Magnetic Order in Hole-Doped Infinite-layer Nickelate Superconductors

Magnetism and superconductivity are closely entangled, elucidating the magnetic interactions in nickelate superconductors is at the heart of understanding the pairing mechanism. Our first-principles and spin-wave theory calculations highlight that NdNiO$_2$ is in the vicinity of a transition between a quasi-two-dimensional (2D) antiferromagnetic (AFM) state and a three-dimensional (3D) C-AFM state. Both states could accurately reproduce the experimentally measured magnetic excitation spectra, which was previously explained in terms of a 2D model. We further reveal that hole doping stabilizes an incommensurate (IC) spin state and the IC wave vector increases continuously. Direct links between hole doping, magnetization, exchange constants, and magnetic order are established, revealing that the competition between first-neighbor and third-neighbor in-plane magnetic interactions is the key for the IC magnetic order

Relationship between IL-10 gene -819C/T polymorphism and the risk of inflammatory bowel disease: A meta-analysis

Background: The -819C/T polymorphism in interleukin 10 (IL-10) gene has been reported to be associated with inflammatory bowel disease (IBD) ,but the previous results are conflicting.Materials and methods: The present study aimed at investigating the association between this polymorphism and risk of IBD using a meta-analysis.PubMed,Web of Science,EMBASE,google scholar and China National Knowledge Infrastructure (CNKI) databases were systematically searched to identify relevant publications from their inception to April 2016.Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects models.Results: A total of 7 case-control studies containing 1890 patients and 2929 controls were enrolled into this meta-analysis, and our results showed no association between IL-10 gene -819C/T polymorphism and IBD risk(TT vs. CC:OR=0.81,95%CI 0.64- 1.04;CT vs. CC:OR=0.92,95%CI 0.81-1.05; Dominant model: OR=0.90,95%CI 0.80-1.02; Recessive model: OR=0.84,95%CI 0.66-1.06). In a subgroup analysis by nationality, the -819C/T polymorphism was not associated with IBD in both Asians and Caucasians. In the subgroup analysis stratified by IBD type, significant association was found in Crohn’s disease(CD)(CT vs. CC:OR=0.68,95%CI 0.48-0.97).Conclusion: In summary, the present meta-analysis suggests that the IL-10 gene -819C/T polymorphism may be associated with CD risk.Keywords: Interleukin 10, -819C/T polymorphism, inflammatory bowel diseaseDue to errors in the previous PDF especially in the 'Cite as' authors names, the PDF fulltext has been reloaded. This information is now correct

The world's largest macroalgal bloom in the Yellow Sea, China: Formation and implications

The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved.The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved

Comparative transcriptomics in Yersinia pestis: a global view of environmental modulation of gene expression

<p>Abstract</p> <p>Background</p> <p>Environmental modulation of gene expression in <it>Yersinia pestis </it>is critical for its life style and pathogenesis. Using cDNA microarray technology, we have analyzed the global gene expression of this deadly pathogen when grown under different stress conditions <it>in vitro</it>.</p> <p>Results</p> <p>To provide us with a comprehensive view of environmental modulation of global gene expression in <it>Y. pestis</it>, we have analyzed the gene expression profiles of 25 different stress conditions. Almost all known virulence genes of <it>Y. pestis </it>were differentially regulated under multiple environmental perturbations. Clustering enabled us to functionally classify co-expressed genes, including some uncharacterized genes. Collections of operons were predicted from the microarray data, and some of these were confirmed by reverse-transcription polymerase chain reaction (RT-PCR). Several regulatory DNA motifs, probably recognized by the regulatory protein Fur, PurR, or Fnr, were predicted from the clustered genes, and a Fur binding site in the corresponding promoter regions was verified by electrophoretic mobility shift assay (EMSA).</p> <p>Conclusion</p> <p>The comparative transcriptomics analysis we present here not only benefits our understanding of the molecular determinants of pathogenesis and cellular regulatory circuits in <it>Y. pestis</it>, it also serves as a basis for integrating increasing volumes of microarray data using existing methods.</p

SNR periodical variation of Chang’E-3 spacecraft orbiting the Moon

AbstractChang’E-3 spacecraft was orbiting the Moon from December 6–14, 2013, and very long baseline interferometry (VLBI) observations were performed to improve the accuracy of its orbit determination. In the process of recording VLBI raw data, 2 bits quantization was implemented. Interesting phenomenon was that signal-to-noise ratio (SNR) of each VLBI station experienced periodical change and had large variation on amplitude while in the Moon’s orbit, whereas SNR kept in a stable level after Chang’E-3 landed on the Moon. Influence of varying elevation angle on SNR was analyzed and compensation of 2 bits quantization harmonics to SNR calculation was investigated. Most importantly, telescope system noise temperature increase caused by the Moon was computed along the time of Chang’E-3 orbiting the Moon, and well matched SNR changing trend in terms of correlation coefficients

Anticonvulsant activities of α-asaronol ((E)-3'-hydroxyasarone), an active constituent derived from α-asarone.

BACKGROUND: Epilepsy is one of chronic neurological disorders that affects 0.5-1.0% of the world's population during their lifetime. There is a still significant need to develop novel anticonvulsant drugs that possess superior efficacy, broad spectrum of activities and good safety profile. METHODS: α-Asaronol and two current antiseizure drugs (α-asarone and carbamazepine (CBZ)) were assessed by in vivo anticonvulsant screening with the three most employed standard animal seizure models, including maximal electroshock seizure (MES), subcutaneous injection-pentylenetetrazole (PTZ)-induced seizures and 3-mercaptopropionic acid (3-MP)-induced seizures in mice. Considering drug safety evaluation, acute neurotoxicity was assessed with minimal motor impairment screening determined in the rotarod test, and acute toxicity was also detected in mice. RESULTS: In our results, α-asaronol displayed a broad spectrum of anticonvulsant activity (ACA) and showed better protective indexes (PI = 11.11 in MES, PI = 8.68 in PTZ) and lower acute toxicity (LD50 = 2940 mg/kg) than its metabolic parent compound (α-asarone). Additionally, α-asaronol displayed a prominent anticonvulsant profile with ED50 values of 62.02 mg/kg in the MES and 79.45 mg/kg in the sc-PTZ screen as compared with stiripentol of ED50 of 240 mg/kg and 115 mg/kg in the relevant test, respectively. CONCLUSION: The results of the present study revealed α-asaronol can be developed as a novel molecular in the search for safer and efficient anticonvulsants having neuroprotective effects as well as low toxicity. Meanwhile, the results also suggested that α-asaronol has great potential to develop into another new aromatic allylic alcohols type anticonvulsant drug for add-on therapy of Dravet's syndrome

Characterization of Zur-dependent genes and direct Zur targets in Yersinia pestis

<p>Abstract</p> <p>Background</p> <p>The zinc uptake regulator Zur is a Zn²⁺-sensing metalloregulatory protein involved in the maintenance of bacterial zinc homeostasis. Up to now, regulation of zinc homeostasis by Zur is poorly understood in <it>Y. pestis</it>.</p> <p>Results</p> <p>We constructed a <it>zur </it>null mutant of <it>Y. pestis </it>biovar <it>microtus </it>strain 201. Microarray expression analysis disclosed a set of 154 Zur-dependent genes of <it>Y. pestis </it>upon exposure to zinc rich condition. Real-time reverse transcription (RT)-PCR was subsequently used to validate the microarray data. Based on the 154 Zur-dependent genes, predicted regulatory Zur motifs were used to screen for potential direct Zur targets including three putative operons <it>znuA, znuCB </it>and <it>ykgM</it>-<it>RpmJ2</it>. The LacZ reporter fusion analysis verified that Zur greatly repressed the promoter activity of the above three operons. The subsequent electrophoretic mobility shift assay (EMSA) demonstrated that a purified Zur protein was able to bind to the promoter regions of the above three operons. The DNase I footprinting was used to identify the Zur binding sites for the above three operons, verifying the Zur box sequence as predicted previously in γ-Proteobacteria. The primer extension assay was further used to determine the transcription start sites for the above three operons and to localize the -10 and -35 elements. Zur binding sites overlapped the -10 sequence of its target promoters, which was consistent with the previous observation that Zur binding would block the entry of the RNA polymerase to repress the transcription of its target genes.</p> <p>Conclusion</p> <p>Zur as a repressor directly controls the transcription of <it>znuA, znuCB </it>and <it>ykgM</it>-<it>RpmJ2 </it>in <it>Y. pestis </it>by employing a conserved mechanism of Zur-promoter DNA association as observed in γ-Proteobacteria. Zur contributes to zinc homeostasis in <it>Y. pestis </it>likely through transcriptional repression of the high-affinity zinc uptake system ZnuACB and two alternative ribosomal proteins YkgM and RpmJ2.</p