Drastic Layer‐Number‐Dependent Activity Enhancement in Photocatalytic H2 Evolution over nMoS2/CdS (n ≥ 1) Under Visible Light

Exploiting noble‐metal‐free cocatalysts is of huge interest for photocatalytic water splitting using solar energy. As an efficient cocatalyst in photocatalysis, MoS₂ is shown promise as a low‐cost alternative to Pt for hydrogen evolution. Here we report a systematical study on controlled synthesis of MoS₂ with layer number ranging from ≈1 to 112 and their activities for photocatalytic H₂ evolution over commercial CdS. A drastic increase in photocatalytic H₂ evolution is observed with decreasing MoS₂ layer number. Particularly for the single‐layer (SL) MoS₂, the SL‐MoS₂/CdS sample reaches a high H₂ generation rate of ≈2.01 × 10^?3m h^?1 in Na₂S–Na₂SO₃ solutions and ≈2.59 × 10^?3m h^?1 in lactic acid solutions, corresponding to an apparent quantum efficiency of 30.2% and 38.4% at 420 nm, respectively. In addition to the more exposed edges and unsaturated active S atoms, valence band–XPS and Mott–Schottky plots analysis indicate that the SL MoS₂ has the more negative conduction band energy level than the H⁺/H₂ potential, facilitating the hydrogen reduction.     

Analysis of particle size reduction on overall surface area and enzymatic hydrolysis yield of corn stover

Particle size of lignocellulose materials is an important factor for enzymatic hydrolysis efficiency. In this study, corn stover was milled and sieved into different size fractions from 1.42, 0.69, 0.34, to 0.21 mm, and the corresponding enzymatic hydrolysis yields were 24.69, 23.96, 25.34, and 26.97 %, respectively. The results indicate that the hydrolysis yield is approximately constant with changing corn stover particle sizes in the experimental range. The overall surface area and the inner pore size measurement show that the overall specific surface area was less than 2 % with the half reduction of particle size due to the greater inner pore surface area. The scanning electron microscope photographs gave direct evidence of the much greater inner pore surface area of corn stover particles. This result provided a reference when a proper size reduction of lignocellulose materials is considered in biorefining operations.     

基因重组TNFα衍生物TRSP10的高效制备及其对DU145细胞抑制作用研究

利用基因工程技术表达能够促使肿瘤细胞DU145凋亡的肿瘤坏死因子α(TNFα)的衍生物TRSP10,并在体外研究其对DU145细胞的抑制效应。以重叠延伸PCR方法合成TRSP10基因序列,并插入高效表达的质粒载体p KYB-MCS的NdeⅠ和SapⅠ酶切位点之间,优化融合蛋白诱导表达的条件,建立了从载体构建到重组菌表达、制备的工艺技术条件。MTT法检测TRSP10对前列腺癌细胞DU145增殖的抑制作用。实验结果表明:重组菌ER2566诱导表达可溶性融合蛋白的最佳条件是诱导剂IPTG浓度为0.8 mmol/L、诱导表达温度37℃、诱导表达时间8h。利用IMPACT系统及HPLC技术纯化制备TRSP10,得到产物纯度达到96%,质谱鉴定确定其分子质量为3.59k Da,与理论值相符;体外细胞学研究结果表明,TRSP10对前列腺癌细胞DU145有明显的抑制作用,在5,10,20,40μmol/L TRSP10及10μmol/L TNFα阳性对照处理后48h抑制率分别达到11.40%,22.97%,33.26%,48.35%及42.50%。     

Mutation of Oryza sativa CORONATINE INSENSITIVE 1b (OsCOI1b) delays leaf senescence

Jasmonic acid (JA) functions in plant development, including senescence and immunity. Arabidopsis thaliana CORONATINE INSENSITIVE 1 encodes a JA receptor and functions in the JA‐responsive signaling pathway. The Arabidopsis genome harbors a single COI gene, but the rice (Oryza sativa) genome harbors three COI homologs, OsCOI1a, OsCOI1b, and OsCOI2. Thus, it remains unclear whether each OsCOI has distinct, additive, synergistic, or redundant functions in development. Here, we use the oscoi1b‐1 knockout mutants to show that OsCOI1b mainly affects leaf senescence under senescence‐promoting conditions. oscoi1b‐1 mutants stayed green during dark‐induced and natural senescence, with substantial retention of chlorophylls and photosynthetic capacity. Furthermore, several senescence‐associated genes were downregulated in oscoi1b‐1 mutants, including homologs of Arabidopsis thaliana ETHYLENE INSENSITIVE 3 and ORESARA 1, important regulators of leaf senescence. These results suggest that crosstalk between JA signaling and ethylene signaling affects leaf senescence. The Arabidopsis coi1‐1 plants containing 35S:OsCOI1a or 35S:OsCOI1b rescued the delayed leaf senescence during dark incubation, suggesting that both OsCOI1a and OsCOI1b are required for promoting leaf senescence in rice. oscoi1b‐1 mutants showed significant decreases in spikelet fertility and grain weight, leading to severe reduction of grain yield, indicating that OsCOI1‐mediated JA signaling affects spikelet fertility and grain filling.     

ABORTED GAMETOPHYTE 1 is required for gametogenesis in Arabidopsis

In flowering plants, the male and female gametogenesis is a crucial step of sexual reproduction. Although many genes have been identi fied as being involved in the gametogenesis process, the genetic mechanisms underlying gametogenesis remains poorly understood. We reported here characterization of the gene, ABORTED GAMETOPHYTE 1(AOG1) that is newly identi fied as essential for gametogenesis in Arabidopsis thaliana. AOG1 is expressed predominantly in reproductive tissues including the developing pollen grains and ovules. The AOG1 protein shares no signi ficant amino acid sequence similarity with other documented proteins and is located mainly in nuclei of the cells. Mutation in AOG1 caused degeneration of pollen at the uninucleate microspore stage and severe defect in embryo sacs, leading to a signi ficant reduction in male and female fertility.Furthermore, the molecular analyses showed that the aog1 mutant signi ficantly affected the expression of several genes, which are required for gametogenesis. Our results suggest that AOG1 plays important roles in gameto genesis at the stage prior to pollen mitosis I(PMI)in Arabidopsis, possibly through collaboration with other genes.     

上海口岸输入性传染性肺结核病患者中结核分枝杆菌北京型特征及耐药性分析

本研究旨在了解上海口岸输入性传染性肺结核病患者中结核分枝杆菌北京型特征及其对一线抗结核药物的耐药情况,从而正确评估输入性结核病给上海地区带来的公共卫生危害,同时为地区传染性结核病防治策略的制定提供依据。针对2009年1月～2013年5月上海口岸入境体检人员中胸部影像学诊断疑似活动性肺结核病的人群,采集其连续3 d的晨痰分离培养结核分枝杆菌,用MGIT960培养法分析其对抗结核药物（链霉素、异烟肼、利福平、乙胺丁醇、吡嗪酰胺）的耐药情况,用目标缺失多重聚合酶链反应（DTM-PCR ）进行结核分枝杆菌北京型分子分型,同时采集其人口学资料。期间共监测到入境外籍疑似活动性肺结核病者193例,其中50例痰液中分离培养到结核分枝杆菌,菌培阳率为25．9％,与我国结核病普查工作中活动性肺结核病菌培阳率（25．9％）相同。分离培养并成功传代、分型的40株结核分枝杆菌中,北京型占57．5％（23／40）,显著低于同期上海口岸出境人群中的90．2％（37／41）。输入性结核分枝杆菌北京型主要来自东南亚地区（71．4％,5／7）和西太平洋地区（57．1％,16／28）。一线5种抗结核药物的耐药性检测结果显示,输入性结核分枝杆菌北京型的总耐药率为30．4％（7／23）,接近上海口岸出境人群的34．1％。输入性耐多药菌株占2．4％（1／42）,分子分型结果显示为非北京型。输入性传染性肺结核病对吡嗪酰胺的耐药率为16．7％,显著高于上海口岸出境人群的2．4％。结果提示,上海口岸输入性肺结核病患者中结核分枝杆菌北京型所占比例显著低于同期出境人群,未发现与性别和年龄相关,未发现输入性结核分枝杆菌北京型对抗结核药物耐药性的显著变化。输入性耐药性结核病带来的公共卫生危害不容忽视,在直接督导下的短程化疗（DOTS）方案中需考虑其高吡嗪酰胺耐药特征。在口岸公共卫生安全风险评估中,需重视输入性结核分枝杆菌北京型与本地流行株的差异。     

胆固醇结晶激活动脉粥样硬化斑块巨噬细胞NLRP3炎症体的途径

动脉粥样硬化既是胆固醇在血管壁聚集的疾病,也是发生在动脉壁的一种低强度慢性炎症形式。近年来有研究证实胆固醇结晶在动脉粥样硬化发生发展中具有重要作用。新的显微技术证实,胆固醇结晶在动脉粥样硬化斑块形成的早期即已出现,并与早期炎症有关。胆固醇结晶通过诱发局部炎症,促进大的脂质核心形成;刺破纤维帽,导致斑块破裂进而促进动脉粥样硬化斑块的进展。在影响斑块进程中,NLRP3炎症体的激活对此发挥了重要的作用。NLRP3炎症体是研究最多最明确的炎症体,其与非炎症性疾病的发生发展密切相关。以胆固醇结晶激活NLRP3炎症体的途径作为研究靶点,为动脉粥样硬化的诊断和治疗提供了新的思路和方法。该文就胆固醇结晶在动脉粥样硬化斑块中激活巨噬细胞NLRP3炎症体的两种途径做一综述。     

食用菌厉眼蕈蚊Lycoriella ingenua在温度逆境下的存活率

以食用菌重要害虫-厉眼蕈蚊属的Lycoriella ingenua为研究对象,研究了不同逆境温度下各虫态存活率的差异。结果表明温度对不同虫态存活率的影响存在显著性差异。成虫和蛹对高温具有一定适应性,卵对高温的适应性最低但具有一定的低温耐受力。在35-40℃高温下,相同暴露时间,各虫态的存活率随温度的升高而降低,但成虫的存活率均高于其它虫态。38℃下全部死亡的暴露时间分别为:成虫48 h,蛹24 h,幼虫12 h,卵2h。在40℃达到全部死亡的暴露时间分别为:成虫24 h、蛹12 h、卵和幼虫0.5 h。低温处理下,各虫态随着暴露时间的延长存活率逐渐降低。5℃低温下,相同暴露时间,成虫存活率均高于其它虫态,但在0℃低温下暴露24 h后全部死亡,显著高于其它虫态;幼虫在低温下取食活动减弱,5℃下暴露24 h后停止取食,相同暴露时间下随着温度的降低存活率下降;蛹对0℃的耐受力高于成虫和幼虫,暴露4 h后可以正常羽化,48 h后全部死亡;卵对短时间的低温具有一定耐受力,但随着暴露时间的延长存活率降低幅度大。