Alteration of the Unsaturated to Saturated Ratio of Fatty Acids in Bacterial Lipids by Alcohols

Silver-coated cloth (SCC) effectively controlled root rot that was caused by Pythium aphanidermatum in hydroponically grown cucumber plants. The presence of SCC in the hydroponic solution reduced the root rot from 100% to 10% 20 days after inoculation with zoospores of P. aphanidermatum. It was suggested that the inhibition of SCC was caused not only by the silver ion dissolved from SCC, but also by the metallic silver and silver compounds formed on the surface of the root.     

湖南苗族、侗族5项人类群体遗传学特征的调查

对湖南苗族、侗族共648例的5项人类群体遗传学特征(利眼、足趾长、起步类型、耳耵聍、指甲型)进行了调查。结果显示:1)两个民族的多数人属于右利眼、拇趾长于二趾、左起步、干型耵聍和长形指甲;2)两个民族的左利眼出现率和拇趾长于二趾的出现率高于国内多数人群;3)足趾长出现率存在明显的民族间差异;苗族利眼和方形指甲出现率均表现出明显的民族内性别差异;4)5项特征间的相关关系不明显。     

基于河流生境调查的东河河流生境评价

河流生境是河流生态系统的重要组成部分,是河流生物赖以生存的基础。以位于三峡库区腹心区域的典型山区河流东河为研究对象,采用河流生境调查(RHS)方法调查河流生境,选择河流生境质量评价指数(HQA)、河流生境退化指数(HMS)评估河流生境现状,分析生境质量和人为干扰的空间分布规律。结果表明,51个河段的HQA值介于24—66之间。29.4%河段的HQA为优,29.4%为良,23.5%为中,9.8%为较差,7.8%为差。从HMS看,7.8%的河段保持较自然状态,19.6%受到轻微的破坏,41.2%退化明显,27.5%退化严重,3.9%受到剧烈破坏。HQA与HMS存在显著的负相关关系。东河上、中、下游河段的HQA无明显差异,但HMS差异显著。从干扰来源看,东河上游和中游河流生境主要受引水式小水电、沿河公路、河道采砂影响。东河下游河流生境受高强度的土地开发(农业用地、建设用地),河道采砂,河堤、排污管、桥梁等水工构筑物的修建和三峡水库水位的波动影响。RHS评价结果能较直观地反映河流生境状况,以及导致河流生境质量衰退的原因。     

Tungsten Disulfide Catalysts Supported on a Carbon Cloth Interlayer for High Performance Li–S Battery

The capacity limitations of insertion‐compound cathodes has motivated interest in a sulfur cathode for a rechargeable battery cell with a metallic‐lithium anode; but irreversible capacity loss owing to solubility of intermediate Li₂S_x (x = 2–8) polysulfides in the organic‐liquid electrolytes used has prevented practical application. A dual‐function cathode structure consisting of layered tungsten disulfide (WS₂) supported both on the cathode current collector and on a carbon cloth interlayer (CCl) gives excellent performance in a lithium half‐cell by providing strong adsorption of the soluble Li₂S_x on the WS₂ with fast access to electrons from the current collector via a blocking carbon cloth interlayer.     

中国作物种质资源学科的奠基者——记中国农业科学院董玉琛院士

董玉琛院士是我国作物种质资源学科的奠基人之一。将个人的成长置于学科发展和社会大背景下,从时代变迁与个人选择、学科发展与个人贡献、学术特点、科学精神与人格魅力4个方面系统梳理了董玉琛院士学术成长历程,探究其取得成功的影响因素,以启发和激励青年学者,传承和弘扬老科学家的科学精神。     

Immobilization of lipase on cotton cloth using the layer-by-layer self-assembly technique

Lipase from Thermomyces lanuginosus was assembled into multiple layers on polyethylenimine treated cotton flannel cloth, utilising the enzymes property of forming bimolecular aggregates via layer-by-layer (LBL) immobilization technique. An increase in lipase activity with increasing enzyme layers confirmed lipase aggregation. A study to compare the activity of enzyme bound by classical LBL technique, containing alternate layers of polyethylenimine and lipase and the modified approach indicated above, showed that more enzyme was bound to cloth in the modified approach. A total of 13 U/cm² of enzyme were bound to cloth till the fifth layer whereas only 10.2 U/cm² were bound till the fifth bilayer in the classical approach. The successful assembly of lipase molecules has shown that this modified technique is a promising approach to immobilize enzymes that aggregate through hydrophobic interactions as nano-films on cloth.     

Airborne enteric micro-organisms and ammonia levels in diaper-changing rooms in kindergartens

Aims: We evaluated risks associated with diaper changing in Finnish kindergartens where children were using either modern disposable paper or reusable cloth diapers. Methods and Results: We determined enteric micro‐organisms and ammonia in diaper‐changing rooms in four kindergartens in autumn and winter in the ambient air. No coliphages were detected in the air. The numbers of faecal coliforms and enterococci in air were typically low regardless of whether the children used either paper or cloth diapers. Ammonia concentrations increased over the background level because of diaper changing. Conclusions: The numbers of bacteria or coliphages are not expected to pose any high air hygiene risks, and increased ammonia air concentrations are unlikely to impair the health of staff or children when diapers are changed in modern kindergartens. However, increased ammonia gas concentrations indicate that some other diaper‐related gas‐phase emissions should be studied to understand better diaper‐related health risks. Significance and Impact of the Study: Modern reusable cloth baby diapers and the modern paper baby diapers used in this study are equally safe with respect to risks from airborne virus, bacteria or ammonia.     

贵州侗族体质人类学研究

本文对生活在贵州的侗族526人(男280人, 女246人)进行了活体观察和调查(观察项目28个,测量项目64个)。调查对象年龄20—55岁, 三代均为侗族。分析结果表明: 贵州侗族男性属中头型、阔面型, 女性属圆头型、超阔面型; 男女均属中鼻型、宽手型、窄肩型、中间体型、中腿型、矮型身材。与我国南方其他31个少数民族群体聚类分析, 结果显示贵州侗族的体质特征与广西瑶族、贵州布依族最为接近, 与湖南瑶族、土家族、贵州台江苗族次之。贵州侗族属蒙古人种南亚类型。     

湖南侗族的手纹研究

报道了湖南通道侗族337例正常人的指纹型、总指纹嵴数（TFRC）、a-b纹嵴线（a-bRC)、atd角、轴三角百分距（tPD)、大鱼际纹、小鱼际纹、指间区纹、掌褶纹、掌纹主线横向指数（MLIT）等手纹参数正常值,并与侗族不同人群和湖南周边不同民族进行了比较,发现湖南侗族手掌真实花纹和掌褶纹分布频率与湖南周边其他已研究过的民族和侗族群体存在明显差异。