人TRAIL基因cDNA的克隆及其在COS—7细胞中的表达

ＴＲＡＩＬ(ＴＮＦｒｅｌａｔｅｄａｐｏｐｔｏｓｉｓｉｎｄｕｃｉｎｇｌｉｇａｎｄ)是最近克隆的肿瘤坏死因子(ＴＮＦ)家族的新成员,由于它的蛋白质结构和生物学效应类似于ＦＡＳ/ＡＰＯ1Ｌ,因此,也被称为ＡＰＯ2Ｌ。在低浓度下,ＴＲＡＩＬ能迅速地诱导多种肿瘤细胞系的?..     

Ascominuta lignicola, a new loculoascomycete from submerged wood in Hong Kong

Ascominuta lignicola gen. et sp. nov. is described and illustrated based on a specimen collected on submerged wood in Hong Kong.Ascominuta lignicola is characterised by relatively small ascomata, globose, 4-spored asci, and ascospores with an elaborate sheath.Ascominuta lignicola is compared withMassarina, Mycosphaerella andWettsteinina. The placement ofAscominuta in the Ascomycetesincertae sedis is discussed.     

中国三种常见蒿属植物潜在地理分布及其主导气候因子

裂叶蒿(Artemisia tanacetifolia)、大籽蒿(Artemisia sieversiana)和艾(Artemisia argyi)是我国常见的蒿属(Artemisia)植物,其分布区域遍布全国.本文利用MaxEnt模型预测3种蒿属植物在当前气候条件以及未来两种气候情景下的潜在分布区.采用受试者工作特征...     

Reproducibility of swallow-induced cortical BOLD positive and negative fMRI activity

Functional MRI (fMRI) studies have demonstrated that a number of brain regions (cingulate, insula, prefrontal, and sensory/motor cortices) display blood oxygen level-dependent (BOLD) positive activity during swallow. Negative BOLD activations and reproducibility of these activations have not been systematically studied. The aim of our study was to investigate the reproducibility of swallow-related cortical positive and negative BOLD activity across different fMRI sessions. We studied 16 healthy volunteers utilizing an fMRI event-related analysis. Individual analysis using a general linear model was used to remove undesirable signal changes correlated with motion, white matter, and cerebrospinal fluid. The group analysis used a mixed-effects multilevel model to identify active cortical regions. The volume and magnitude of a BOLD signal within each cluster was compared between the two study sessions. All subjects showed significant clustered BOLD activity within the known areas of cortical swallowing network across both sessions. The cross-correlation coefficient of percent fMRI signal change and the number of activated voxels across both positive and negative BOLD networks were similar between the two studies (r ≥ 0.87, P < 0.0001). Swallow-associated negative BOLD activity was comparable to the well-defined "default-mode" network, and positive BOLD activity had noticeable overlap with the previously described "task-positive" network. Swallow activates two parallel cortical networks. These include a positive and a negative BOLD network, respectively, correlated and anticorrelated with swallow stimulus. Group cortical activity maps, as well as extent and amplitude of activity induced by volitional swallowing in the cortical swallowing network, are reproducible between study sessions.     

构建基于CRISPR/Cas9技术敲除ALOX5的质粒

旨在利用CRISPR/Cas9技术构建敲除花生四烯5-脂氧合酶基因(Arachidonate 5-lipoxygenase gene,ALOX5)的重组质粒。设计合成3对靶向敲除ALOX5第六外显子的sgRNA,将其分别插入到CRISPR/Cas9质粒骨架pX458载体中,转化感受态大肠杆菌DH5α后挑取克隆,通过测序评估重组质粒是否构建成功。将构建好的重组质粒转染293T细胞,在荧光显微镜下观察转染效果,挑取转染成功的细胞,用试剂盒提取转染细胞基因组DNA,PCR扩增含敲除位点的DNA片段,用测序技术获得核苷酸序列,用DNAStar软件分析转染细胞中ALOX5基因敲除情况。测序结果表明2对双链sgRNA寡核苷酸已插入质粒,且序列正确,靶向ALOX5基因的重组质粒pX458-sgRNAs-ALOX5构建成功。其在293T细胞中的转染效率约为50%,用一代测序法未检测到sgRNAs的切割效果。初步表明利用CRISPR/Cas9技术成功构建靶向ALOX5基因的重组质粒pX458-sgRNAs-ALOX5。     

Role of fungi in freshwater ecosystems

There are more than 600 species of freshwater fungi with a greater number known from temperate, as compared to tropical, regions. Three main groups can be considered which include Ingoldian fungi, aquatic ascomycetes and non-Ingoldian hyphomycetes, chytrids and, oomycetes. The fungi occurring in lentic habitats mostly differ from those occurring in lotic habitats. Although there is no comprehensive work dealing with the biogeography of all groups of freshwater fungi, their distribution probably follows that of Ingoldian fungi, which are either cosmopolitan, restricted to pantemperate or pantropical regions, or in a few cases, have a restricted distribution. Freshwater fungi are thought to have evolved from terrestrial ancestors. Many species are clearly adapted to life in freshwater as their propagules have specialised aquatic dispersal abilities. Freshwater fungi are involved in the decay of wood and leafy material and also cause diseases of plants and animals. These areas are briefly reviewed. Gaps in our knowledge of freshwater fungi are discussed and areas in need of research are suggested.     

杨树溃疡病生防菌株N6-34抗菌活性物质的分离纯化与结构鉴定

【背景】杨树溃疡病是一种主要由葡萄座腔菌引起的杨树枝干病害,危害严重。前期从杨树中分离到一株内生拮抗细菌N6-34,研究表明该菌株拮抗效果好,对多种植物病原菌均有较强的拮抗作用。【目的】对拮抗细菌N6-34产生的抗菌活性物质进行分离纯化,并鉴定了活性物质组分的结构。【方法】通过硫酸铵盐析、甲醇抽提、分子筛、高效液相色谱等方法分离纯化N6-34菌株的抗菌活性物质,并对其进行结构鉴定。【结果】N6-34菌株发酵液经多步分离纯化,共获得14个组分,其中有13个组分具有抗菌活性,经一级质谱分析,获得了13种抗菌活性组分的分子量;经二级质谱分析,将13种抗菌活性物质鉴定为Fengycin A或Fengycin B的同系物或同分异构体。【结论】从N6-34菌株发酵液中分离获得了13种抗菌成分,为杨树溃疡病的生物防治提供了理论依据。     

The spiral glands of Nereis

Summary The spiral organs of Nereis have been shown to be compound glands and not photoreceptors. The ducts of two or three types of secretory cells attach themselves in a serial manner to a spirally wound axial columella which lies just below the cuticle. The large intra-cellular ducts terminate in a number of fine ducts which penetrate the columella and open through it into the lumen of the gland. This communicates to the outside through a pore in the cuticle. The secretions are muco-polysaccharides which are probably mixed in the lumen before discharge.We should like to acknowledge the support of this work by the Science Research Council.