Effect of total flavonoid in rabdosia rubescens on tolerant mice models under cerebral anoxia

ObjectiveTo study the protective effect of total flavonoid in rabdosia rubescens on BIT model by brain ischemic tolerance (hereinafter BIT) model of mice.MethodBIT model is used to block bilateral common carotid arteries and to copy BIT model of mice. After 10 min of transient ischemia for rats in preconditioning group, the mice in the nimodipine group and naoluotong capsule group were given the total flavonoid in rabdosia rubescens (300 mg/kg, 150 mg/kg, 75 mg/kg) for gavage, sham operation group, ischemia/reperfusion injury (hereinafter IRI) group and BIT group were fed with the same volume of 0.5% sodium carboxymethyl cellulose (CMC) once a day for 5 days. After administration for 1 h on day 5 (120 h), the rats in the other groups except for the sham operation group were treated with blood flow block for 30 min and reperfusion for 22 h. The serum NSE level were measured and the brain NO content and NOS activity changes was measured to observe the histopathological changes of brain tissue.ResultsBIT models of mice and in rats were both successfully replicated. The total flavonoid in rabdosia rubescens can decrease the mortality of mice, decrease serum NSE level, increase the content of NO and the activity of NOS in the brain tissue of mice, and improve the pathological damage of cortex and hippocampus of mice.ConclusionThe total flavonoid in rabdosia rubescens can stimulate an endogenous protective mechanism by inducing the release of low levels of cytokines NO and NOS, which reduces the release of serum NSE, relieves the brain tissue ischemia-reperfusion injury, and further improves the protection effect of ischemic preconditioning on brain injury. The damage of brain tissue ischemia and reperfusion, and further improve the ischemia Protective effect of preconditioning on brain injury.     

Site-directed mutagenesis of UbiA to promote menaquinone biosynthesis in Elizabethkingia meningoseptica

To increase the menaquinone (MK) content of an Elizabethkingia meningoseptica, site-directed mutagenesis was generated to suppress 4-hydroxybenzoate octaprenyl transferase (UbiA) activity and subsequently blocked the ubiquinone (UQ) biosynthesis pathway. Fourteen conserved residues except L174 and G211 were mutated to analyze the effect of site-directed mutagenesis. The expression of UbiA in twelve mutants was decreased in both mRNA and protein levels, which resulted in the decrease of UQ concentration. Based on MenA expression level, 12 mutants were divided into two groups. Second group such as N72A, D76A, K81A, L139A, and D198A enhanced the expression of MenA, which increased MK production by 127.1%, 87.9%, 96.2%, 109.7% and 130.0% in wt-EmUbiA, respectively. In general, blocking UQ synthesis pathway for by site-directed mutagenesis of the active site of UbiA in E. meningoseptica was a promising strategy to increase MK production in E. meningoseptica.     

人桥本甲状腺炎甲状腺组织中miRNAs表达谱的差异性分析

目的：桥本甲状腺炎是一种自身免疫性甲状腺疾病，且其发病率呈逐年上升趋势，在医疗实践中，HT 被认为是原发性甲状腺 功能减退最常见的原因，同时较易发生甲状腺癌和淋巴瘤。另外，HT 缺乏早期诊断标准，临床上发病隐匿且表现多样，病人多不 易察觉而延误治疗。本文旨在应用microRNA 芯片技术系统筛查HT病变甲状腺组织，以此研究并揭示其HT 的miRNA 表达谱 变化。方法：本研究首先采用microRNA芯片技术，对正常甲状腺组织及桥本甲状腺炎甲状腺组织中microRNA 的表达进行比较， 筛选桥本甲状腺炎中差异性表达的miRNAs。结果：与正常甲状腺相比，在桥本甲状腺炎及其合并甲状腺乳头状癌的一侧桥本甲 状腺炎中分别有39 个和25 个miRNAs 分子发生了差异性表达（P<0.05），比较2 组中共有的miRNAs 发现，miR-142-3p、 miR-338-3p、miR-454、miR-146a、miR-29b-1*、miR-150、miR-223 表达上调，miR-654-5p、miR-601、miR-198、miR-1226* 表达下调 （log2 FC≥ 2，P＜0.05）；而miR-142-5p 在原发性桥本甲状腺炎中表达显著性升高近8 倍（log2 FC=7.959，P＜0.01）。结论：我们通 过microRNA芯片，首次直接系统筛查了桥本甲状腺炎病变组织相关miRNA 表达谱，总体上初步掌握了与正常甲状腺相比，桥 本甲状腺炎及合并甲状腺乳头状癌时其miRNA 表达谱的变化情况，为我们后续的研究提供了方向与基础。     

Thiophene Rings Improve the Device Performance of Conjugated Polymers in Polymer Solar Cells with Thick Active Layers

Developing novel materials that tolerate thickness variations of the active layer is critical to further enhance the efficiency of polymer solar cells and enable large‐scale manufacturing. Presently, only a few polymers afford high efficiencies at active layer thickness exceeding 200 nm and molecular design guidelines for developing successful materials are lacking. It is thus highly desirable to identify structural factors that determine the performance of semiconducting conjugated polymers in thick‐film polymer solar cells. Here, it is demonstrated that thiophene rings, introduced in the backbone of alternating donor–acceptor type conjugated polymers, enhance the fill factor and overall efficiency for thick (>200 nm) solar cells. For a series of fluorinated semiconducting polymers derived from electron‐rich benzo[1,2‐b:4,5‐b′]dithiophene units and electron‐deficient 5,6‐difluorobenzo[2,1,3]thiazole units a steady increase of the fill factor and power conversion efficiency is found when introducing thiophene rings between the donor and acceptor units. The increased performance is a synergistic result of an enhanced hole mobility and a suppressed bimolecular charge recombination, which is attributed to more favorable polymer chain packing and finer phase separation.     

Insights into the discrepant luminescence for BaSiO3:Eu2+ phosphors prepared by solid‐state reaction and precipitation reaction methods

Two synthesis routes, solid‐state reaction and precipitation reaction, were employed to prepare BaSiO₃:Eu²⁺ phosphors in this study. Discrepancies in the luminescence green emission at 505 nm for the solid‐state reaction method sample and in the yellow emission at 570 nm for the sample prepared by the precipitation reaction method, were observed respectively. A detail investigation about the discrepant luminescence of BaSiO₃:Eu²⁺ phosphors was performed by evaluation of X‐ray diffraction (XRD), photoluminescence (PL)/photoluminescence excitation (PLE), decay time and thermal quenching properties. The results showed that the yellow emission was generated from the BaSiO₃:Eu²⁺ phosphor, while the green emission was ascribed to a small amount of Ba₂SiO₄:Eu²⁺ compound that was present in the solid‐state reaction sample. This work clarifies the luminescence properties of Eu²⁺ ions in BaSiO₃ and Ba₂SiO₄ hosts.     

Side chain flexibility and coupling between the S4‐S5 linker and the TRP domain in thermo‐sensitive TRP channels: Insights from protein modeling

The transient receptor potential (TRP) superfamily is subdivided into several subfamilies on the basis of sequence similarity, which is highly heterogeneous but shows a molecular architecture that resembles the one present in members of the Kv channel superfamily. Because of this diversity, they produce a large variety of channels with different gating and permeability properties. Elucidation of these particular features necessarily requires comparative studies based on structural and functional data. The present study aims to compilate, analyze, and determine, in a coherent way, the relationship between intrinsic side‐chain flexibility and the allosteric coupling in members of the TRPV, TRPM, and TRPC families. Based on the recently determined structures of TRPV1 and TRPV2, we have generated protein models for single subunits of TRPV5, TRPM8, and TRPC5 channels. With these models, we focused our attention on the apparently crucial role of the GP dipeptide at the center of the S4‐S5 linker and discussed its role in the interaction with the TRP domain, specifically with the highly‐conserved Trp during this coupling. Our analysis suggests an important role of the S4‐S5L flexibility in the thermosensitivity, where heat‐activated channels possess rigid S4‐S5 linkers, whereas cold‐activated channels have flexible ones. Finally, we also present evidence of the key interaction between the conserved Trp residue of the TRP box and of several residues in the S4‐S5L, importantly the central Pro. Proteins 2017; 85:630–646. © 2016 Wiley Periodicals, Inc.     

Rhodobacteraceae on the marine brown alga Fucus spiralis are abundant and show physiological adaptation to an epiphytic lifestyle

Macroalgae harbour specific microbial communities on their surface that have functions related to host health and defence. In this study, the bacterial biofilm of the marine brown alga Fucus spiralis was investigated using 16S rRNA gene amplicon-based analysis and isolation of bacteria. Rhodobacteraceae (Alphaproteobacteria) were the predominant family constituting 23% of the epibacterial community. At the genus level, Sulfitobacter, Loktanella, Octadecabacter and a previously undescribed cluster were most abundant, and together they comprised 89% of the Rhodobacteraceae. Supported by a specific PCR approach, 23 different Rhodobacteraceae-affiliated strains were isolated from the surface of F. spiralis, which belonged to 12 established and three new genera. For seven strains, closely related sequences were detected in the 16S rRNA gene dataset. Growth experiments with substrates known to be produced by Fucus spp. showed that all of them were consumed by at least three strains, and vitamin B₁₂ was produced by 70% of the isolates. Since growth of F. spiralis depends on B₁₂ supplementation, bacteria may provide the alga with this vitamin. Most strains produced siderophores, which can enhance algal growth under iron-deficient conditions. Inhibiting properties against other bacteria were only observed when F. spiralis material was present in the medium. Thus, the physiological properties of the isolates indicated adaption to an epiphytic lifestyle.