影响正常口腔念珠菌检出率的方法学研究

目的:研究不同检测方法对正常口腔念珠菌检出率的影响,寻找一种比较简便可靠的检测方法.方法:以健康的平均年龄7.4岁的儿童为检测人群,比较不同的取样部位,取样方法,检测方法,被检人群口腔中白色念珠菌以及其他念珠菌的检出率.结果:取样和检测方法对检出率有不同程度的影响,PCR检测方法的检出率显著高于培养法.结论:黏膜拭子加离心,和CHROMagar CandidaTM鉴定培养基相结合的方法是一种简便理想的分离培养方法,PCR方法则敏感度更高.     

甘肃兴隆山主要森林类型凋落物累积量及持水特性

2010年,采用野外实地观测与室内浸水法,对甘肃兴隆山6种主要森林类型(青杆林、青杆-白桦林、山杨-白桦林、灌丛林、落叶松林、油松林)林下凋落物的累积量、持水量、持水率和吸水速率进行了研究.结果表明:不同森林类型凋落物层累积量在13.40～46.32 t·hm-2,为油松林＞青杆-白桦林＞落叶松林＞青杆林＞灌丛林＞山杨-白桦林,且针叶林累积量高于阔叶林;半分解层累积量所占比例均高于未分解层.凋落物最大持水率为185.5％～303.6％,落叶松林最大,油松林最小,持水率与浸水时间呈对数关系;针叶林未分解层持水率均小于半分解层,而阔叶林则相反.凋落物最大持水量在3.94～8.59 mm,为油松林＞落叶松林＞青杆-白桦林＞青杆林＞灌丛林＞山杨-白桦林;持水量与浸水时间存在对数关系;半分解层持水量均大于未分解层.凋落物吸水速率与浸水时间存在幂函数关系,在浸水前1h内,吸水速率均直线下降,而浸水1.0h后吸水速率较小,且不同时段间变化较小;半分解层吸水速率高于未分解层.凋落物有效拦蓄量(深)为青杆-白桦林(5.97 mm)＞油松林(5.59 mm)＞落叶松林(5.46 mm)＞青杆林(4.30 mm)＞灌丛林(3.03 mm)＞山杨-白桦林(2.13 mm).     

Evaluation of oxygen adaptation and identification of functional bacteria composition for anammox consortium in non-woven biological rotating contactor

In this study, the anammox consortium was found to adapt to the wastewater containing dissolved oxygen (DO), as the DO was gradually increased. Batch tests indicated the maximum aerobic ammonium oxidizing activity of the consortium was 1.38mmolNH(4)(+)-N(gVSS)(-1)day(-1), which played key roles in the oxygen consumption process; the maximum anaerobic ammonium oxidizing activity was slightly decreased after long-term oxygen exposure, but only from 21.23mmolNH(4)(+)-N(gVSS)(-1)day(-1) to 20.23mmolNH(4)(+)-N(gVSS)(-1)day(-1). Microbiological community analysis identified two strains similar to Nitrosomonas eutropha were responsible for oxygen consumption, which were able to exist in the autotrophic anaerobic condition for long periods and protect anammox bacteria Planctomycetales from the influence of oxygen. Microbiological composition analysis showed Nitrosomonas and Planctomycetales approximately accounted for 10% and 70% of the bacteria, respectively. The possibility of cultivation anammox consortium in presence of DO will lead to substantial savings of energy and resource in the industrial application.     

口蹄疫病毒3A基因在大肠杆菌中的高效表达

将口蹄疫病毒(Foot\|and\|Mouth Disease Virus,FMDV)的3A基因克隆到线形化的原核表达载体pProEX\|HTb中,转化大肠杆菌BL21和DH5α,经氨苄抗性筛选得到阳性克隆,IPTG诱导表达。SDSPAGE和West bolt结果证实大肠杆菌菌体不可溶性蛋白中富含3A蛋白,说明3A蛋白在表达产物中以包涵体的形式存在,所表达的蛋白含量占菌体蛋白的29.2%。     

Glyoxalase in ageing

The glyoxalase system has been studied since 1913. The biochemical function of this enzymatic system is the metabolism of reactive dicarbonyl metabolites, glyoxal and methylglyoxal, to less reactive products. In the last decade research has shown that methylglyoxal is the precursor of quantitatively important damage to the proteome and genome, forming mainly hydroimidazolone and imidazopurinone adducts in protein and DNA respectively. The aim of this article is to review the evidence of the involvement of the glyoxalase system in ageing and role of glyoxalase in future research into healthy ageing-mainly in mammalian systems for insights into consequences and interventions in human health. Protein and DNA damage by glyoxalase system substrates is linked to dysfunction of proteins susceptible to dicarbonyl modification-the dicarbonyl proteome, and DNA instability and mutation. A component of the glyoxalase system, glyoxalase 1, is a gene with expression influential on lifespan-increasing longevity being associated with increased expression of glyoxalase 1. The glyoxalase 1 gene is also a site of copy number variation in both transcribed and non-transcribed regions giving rise to population variation of expression. The glyoxalase system and Glo1 expression particularly is therefore likely linked to healthy ageing.     

Pyrosequencing Reveals Contrasting Soil Bacterial Diversity and Community Structure of Two Main Winter Wheat Cropping Systems in China

Microbes are key components of the soil environment, playing an important role in maintaining soil health, sustainability, and productivity. The composition and structure of soil bacterial communities were examined in winter wheat–rice (WR) and winter wheat–maize (WM) cropping systems derived from five locations in the Low-Middle Yangtze River plain and the Huang-Huai-Hai plain by pyrosequencing of the 16S ribosomal RNA gene amplicons. A total of 102,367 high quality sequences were used for multivariate statistical analysis and to test for correlation between community structure and environmental variables such as crop rotations, soil properties, and locations. The most abundant phyla across all soil samples were Proteobacteria, Acidobacteria, and Bacteroidetes. Similar patterns of bacterial diversity and community structure were observed within the same cropping systems, and a higher relative abundance of anaerobic bacteria was found in WR compared to WM cropping systems. Variance partitioning analysis revealed complex relationships between bacterial community and environmental variables. The effect of crop rotations was low but significant, and interactions among soil properties, locations, and crop rotations accounted for most of the explained variation in the structure of bacterial communities. Soil properties such as pH, available P, and available K showed higher correlations (positive or negative) with the majority of the abundant taxa. Bacterial diversity (the Shannon index) and richness (Chao1 and ACE) were higher under WR than WM cropping systems.     

不同批号蕲蛇酶在家兔血液凝固系统上的生物活性检测

目的：研究不同批号蕲蛇酶静脉给予家兔后,对血液凝固系统各项指标的影响,以判定其药效的稳定性。方法：取家兔,纯白色,体重1．5－2．5kg,雌雄兼用,每日静脉注入蕲蛇酶1．0u/kg.d^-1,连用3－5天,药前、药后从心脏取血6ml,取全血1ml作血栓形成;余血以3．0％枸橼酸钠按1：9抗凝,分离富血小板血浆（PRP）,测定其血小板数目和血小板聚集率,以贫血小板血浆（PPP）测定凝血酶时间（TT）,凝血酶原时间（PT）,部分凝血活酶时间（KPTT）以及纤维蛋白原（Fg)含量。结果：5个批号的蕲蛇酶药后3天或5天均可明显使血栓形成的重量减轻,长度缩短,Fg含量减少（P＜0．01）,TT,PT,KPTT均延长（P＜0．05－0．01）,血小板数轻度减少,聚集率抑制达20％－50％,结论：不同批号的蕲蛇酶静脉给予家兔,具有显著的作用于血液凝固系统,导致血栓形成减少,表明对心脑血管内血栓形成药学相同,说明用家 兔作为鉴定药品质量是可行而必须。     

Identification and characterization of a novel salt‐tolerant esterase from a Tibetan glacier metagenomic library

A salt‐tolerant esterase, designated H9Est, was identified from a metagenomic library of the Karuola glacier. H9Est gene comprised 1071 bp and encoded a polypeptide of 357 amino acids with a molecular mass of 40 kDa. Sequence analysis revealed that H9Est belonged to the family IV of bacterial lypolitic enzyme. H9Est was overexpressed in Escherichia coli and the purified enzyme showed hydrolytic activity towards p‐nitrophenyl esters with carbon chain from 2 to 8. The optimal esterase activity was at 40°C and pH 8.0 and the enzyme retained its activity towards some miscible organic solvents such as polyethylene glycol. A three‐dimensional model of H9Est revealed that S200, D294, and H324 formed the H9Est catalytic triad. Circular Dichroism spectra and molecular dynamic simulation indicated that the esterase had a wide denaturation temperature range and flexible loops that would be beneficial for H9Est performance at low temperatures while retaining heat‐resistant features. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:890–899, 2015