Investigation of twisted monofilament cord properties made of nylon 6.6 and polyester

A tire is a composite of rubber and reinforcing materials. Polymeric materials used as reinforcing components are usually synthetic yarns. These synthetic yarns have high tenacity, they are made of continuous multifilaments. The yarns are converted in the cord form to provide desired mechanical, thermal and adhesion properties by a series of conversion processes. Besides of multifilament synthetic cords, there are some specific areas in which single ply monofilament cords have been utilized as a reinforcing element. In this study, new cord structures have been developed by using monofilament yarns and by imitating multifilament cords. New cord structures exhibited some very interesting cord properties compared to both single ply monofilament cord and multifilament cords. Monofilament yarns having diameter between 0.23 and 0.50 mm have been twisted together from 3 to 6 plies based on mixed Taguchi model to form cords. Nylon 6.6 and Polyester monofilament yarns have been selected because of common application of their multifilament counterpart yarns in tire carcass and capply. The twisted monofilament cords have been adhesive treated to produce cords ready to adhere rubber. The mechanical properties, thermal stability, adhesion with rubber, fatigue properties under dynamic conditions, retention of properties after curing and microscopic analysis of the cords have been analyzed. The cords have been found to possess some benefits for tire carcass, breaker, belt and belt protective layer applications with their superior fatigue performance, cut resistance, stiffness, ligth weigth etc.     

Effect of puffing on ultrastructure and physical characteristics of cereal grains and flours

Puffed cereals are commonly used as ready-to-eat breakfast foods or as ingredients in snack formulations. Few investigations have been made on the ultrastructure and physical characteristics of puffed cereals; the properties of the flours milled from them have been even less investigated. The changes associated with the gun puffing process were evaluated for six different grains: common wheat, emmer wheat, rye, barley, rice and buckwheat. The results demonstrate that the effect of the puffing treatment is strongly influenced by the morphology and composition of the kernel. Puffed rye and rice have a very porous matrix, made up of numerous cavities of different sizes separated by a very thin ‘wall’ puffed wheat, emmer wheat and barley on the other hand show a much more compact, homogeneous and less porous structure; puffed buckwheat is characterised by a large number of small and regular cavities. Moreover, puffing induces significant changes in the structure and physical properties of the starch and an increased water holding capacity of both the grains and the flours.     

大豆分子标记及辅助选择育种技术的发展

分子标记、QTL的研究和辅助选择应用已经得到很大的发展,一批与大豆形态性状、产量性状、品质性状、生态性状、抗生物胁迫性状相关的QTL在国内外均有报道.但近年来分子标记和QTL研究在比较发达的国家已经转向功能标记(FMs:EST-SSR、SNP和候选基因)的研究,相继肩动大豆EST计戈呼和大豆功能基因组计划,以期使功能基因和性状直接联系起来,目前已经取得了显著成效.而我国目前分子标记和QTL的研究还主要集中在利用随机标记(RMs:RAPD、SSR和AFLP)对性状进行研究.该文就国内外大豆分子标记和分子标记辅助育种及分子育种技术发展动态和发展中存在的主要问题做一概述.     

Sorghum and millet phenols and antioxidants

Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.     

Sorghum and millet phenols and antioxidants

Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.     

Comparative and Combined Effects of Epigallocatechin-3-gallate and Caffeine in Reducing Lipid Accumulation in Caenorhabditis elegans

Plant Foods for Human Nutrition - Epigallocatechin-3-gallate (EGCG) and caffeine, two phytochemicals found in a wide range of natural dietary sources, have been reported to have protective effects...     

The concept and development of management profiles for potato cultivars and selections

Potato (Solanum tuberosum L.) growers in Ontario, Canada have funded research specifically to develop management profiles for potato cultivars. Such profiles have been developed for Atlantic, Conestoga, Jemseg, Monona, Norchip, Shepody, Superior and Yukon Gold grown under Ontario conditions. The development of management profiles to facilitate the optimum production and storage of different potato cultivars and selections is recognized as a valuable tool in aiding in the technology transfer of potato research and information to growers and processors. Unique differences among cultivars such as herbicide tolerance, time and duration of bulking, fertility requirements, processing quality and other variables may have significant impact on management of a particular cultivar. Some cultivar traits can be modified via management techniques while others cannot. A clarification of such information is critical to the industry.     

微量元素与胆固醇的相互作用

微量元素与影响人类健康的某些疾病密切相关,高胆固醇血症是动脉粥样硬化Ahterosclerosis(As)的致病原因,而Cu、Zn、Cr、Cd四种金属元素与胆固醇血症紧密相关,诸多医学、生物学实验进行了有关报道与解释,本文对此阐述了我们的研究结果。     

落花生之黄曲毒素防治与其保健植物化合物之探讨

落花生是全球熟悉与普遍消费的作物,其特殊之香气与酥脆质地吸引绝大多数消费者的味口。然而,由于落花生可能被黄曲毒素产生菌污染产毒,导致许多消费者常将落花生与黄曲毒素（系一种天然致癌物质）联想在一起,因而犹豫甚至拒绝进食含落花生之产品。落花生虽然是黄曲毒素产生菌生长之良好基质,但必须遭受其侵入,且得到充分生长才会产毒。田间栽种时有适当灌溉、采收后花生荚果迅速干燥,以及良好仓储条件,是落花生采收前后有效降低黄曲毒素污染的最重要方法。加工时,先将花生仁轻度焙烤,再脱膜并以色差电子自动筛检,则能更进一步将被霉菌污染之花生仁筛除,筛选后之花生仁可加工制作安全无虞之高品质食品。另外,有鉴于黄曲毒素产生菌普遍存在于土壤中,但采收后之健康花生荚或花生仁几乎均无黄曲毒素之污染,经探讨得知,落花生具有生合成二苯乙烯类化合物（包括熟知的白藜芦醇在内之植物防御素）以抵抗微生物入侵之本能。因此,落花生可经由发芽制备花生芽作为机能蔬菜,并促进生合成二苯乙烯类化合物,包括白藜芦醇,Arachidin-1,Arachidin-3及Isopentadienylresveratrol（IPD）等,这些二苯乙烯类化合物目前已知,具有相当值得重视的抗氧化与抗发炎活性,具有进一步开发作为饮食补充或保健产品之潜力。     

Characterisation and physical mapping of cyclophilin A genes and identification of new classes of cyclophilins in wheat

The cyclophilins, a class of ‘foldase’ enzymes that catalyse the rate-limiting step of peptidyl-prolyl cis–trans isomerization, are up-regulated during wheat endosperm development and suggested to be important for folding of the storage proteins, thus influencing wheat quality. However, little information exists on the types of cyclophilins expressed, the genes encoding these, and their possible functions in wheat endosperm. We have characterised three isoforms of genes encoding cyclophilin A from eight wheat cultivars, using previously isolated cDNAs. The genes are small, intronless, comprise a small multi-gene family, lack any inter-cultivar polymorphisms and localise to chromosomal arms 6AS, 6BS and 6DS, in a region where genes for other quality traits are localised, the locus at 6AS possibly having duplicated genes. Further, cDNAs encoding two novel, endosperm-expressed classes of cyclophilins have been isolated, one being potentially plastid-localised and the other, a nuclear protein with cyclophilin-like domains. In-silico analyses have further led to identification of another form of cyclophilin A and a potentially ER-localised, endosperm-expressed cyclophilin B. The plastid and ER-localised forms are of particular relevance to events occurring during endosperm maturation. The results thus provide valuable data and molecular tools for isolation and analysis of these genes, to address their roles and any association with wheat quality traits.     

余甘提职物及其制品清除自由基和抗氧化的特性

用化学发光法（CL）和顺磁共振法（ESR）测定结果表明,余甘提取物及其制品有清除活性氧的能力。通过大鼠大脑缺血、缺氧模型试验,证明余甘果汁对大脑缺血再灌的氧化损伤有防护作用。余甘提取物混入霜剂后,仍然有清除自由基的活性,而已其有效成分可透过皮肤,清除皮肤内部产生的过量自由基。该有效成分既耐热又耐贮存,因而具有较好的应用前景。     

Synthesis and Biological Activities of Cyclodepsipeptides of Aurilide Family from Marine Origin

Aurilides are a class of depsipeptides occurring mainly in marine cyanobacteria. Members of the aurilide family have shown to exhibit strong cytotoxicity against various cancer cell lines. These compounds bear a pentapeptide, a polyketide, and an α-hydroxy ester subunit in their structure. A large number of remarkable studies on aurilides have emerged since 1996. This comprehensive account summarizes the biological activities and total syntheses of natural compounds of the aurilide family as well as their synthetic analogues.     

The Microstructure,Antibacterial and Antitumor Activities of Chitosan Oligosaccharides and Derivatives

Chitosan obtained from abundant marine resources has been proven to have a variety of biological activities. However, due to its poor water solubility, chitosan application is limited, and the degradation products of chitosan oligosaccharides are better than chitosan regarding performance. Chitosan oligosaccharides have two kinds of active groups, amino and hydroxyl groups, which can form a variety of derivatives, and the properties of these derivatives can be further improved. In this review, the key structures of chitosan oligosaccharides and recent studies on chitosan oligosaccharide derivatives, including their synthesis methods, are described. Finally, the antimicrobial and antitumor applications of chitosan oligosaccharides and their derivatives are discussed.     

华南地区热带亚热带草种质资源考察收集与保存利用现状及前景

作为最基本的农业自然资源,牧草在草地畜牧业、生态环境保存和农业可持续发展方面具有重要作用。本文简述了热带亚热带草种质资源在华南地区的调查收集、保存鉴定及繁育保存的方法。自20世纪40年代以来,中国热带农业科学院热带牧草研究中心一直致力于热带亚热带草种质资源的收集、保存和利用。目前已建成完整的热带牧草种质资源保存利用体系,包括低温保存种子库、离体保存库及无性繁殖材料田间保存圃,已收集保存华南地区12科161属435种5 190份野生牧草种质资源,引进保存豆科和禾本科2科42属87种1 042份外来牧草种质资源。其中低温种子库保存6科96属207种2 870份,离体保存3科6属6种482份,无性繁殖材料田间保存3科8属10种341份。     

Geographic variability and anti-staphylococcal activity of the chrysophaentins and their synthetic fragments

Drug-resistant Staphylococcus aureus is a continuing public health concern, both in the hospital and community settings. Antibacterial compounds that possess novel structural scaffolds and are effective against multiple S. aureus strains, including current drug-resistant ones, are needed. Previously, we have described the chrysophaentins, a family of bisdiarylbutene macrocycles from the chrysophyte alga Chrysophaeum taylori that inhibit the growth of S. aureus and methicillin-resistant S. aureus (MRSA). In this study we have analyzed the geographic variability of chrysophaentin production in C. taylori located at different sites on the island of St. John, U.S. Virgin Islands, and identified two new linear chrysophaentin analogs, E2 and E3. In addition, we have expanded the structure activity relationship through synthesis of fragments comprising conserved portions of the chrysophaentins, and determined the antimicrobial activity of natural chrysophaentins and their synthetic analogs against five diverse S. aureus strains. We find that the chrysophaentins show similar activity against all S. aureus strains, regardless of their drug sensitivity profiles. The synthetic chrysophaentin fragments indeed mimic the natural compounds in their spectrum of antibacterial activity, and therefore represent logical starting points for future medicinal chemistry studies of the natural products and their analogs.     

人参三七皂苷化学成分及药理作用对比研究

对来源于五加科人参属近缘植物人参和三七的化学成分和药理作用进行了综合比较。两种药材在化学成分上既具有相似性又存在着差异性,因而在药理作用上也表现出一定的相似性和区别。     

磷运筹和干旱胁迫对冬小麦农艺性状和品质性状的影响

为探究不同水磷运筹对冬小麦农艺性状和品质性状的影响,以冬小麦品种新冬20号和新冬23号为材料,研究了不同水分和施磷时期处理对冬小麦农艺性状、籽粒蛋白和淀粉含量、淀粉特性、植株和籽粒全磷含量的影响.结果表明:(1)品种、水分、施磷时期及其互作效应对小麦株高和千粒重均有显著影响;(2)品种、水分及三个试验因素的互作效应对籽粒淀粉和蛋白含量均有显著影响;籽粒淀粉含量以新冬20号干旱胁迫下一次施磷(DT+P1)处理的最高,新冬23号以干旱胁迫下三次施磷(DT+P3)处理最高;两个品种均以适水对照下三次施磷(WT+P3)处理的籽粒蛋白含量最高;(3)不同磷素运筹和干旱胁迫条件下,小麦淀粉粒的微观结构发生了变化,进而影响了淀粉粒的水解效率;(4)两个小麦品种的籽粒硬度均以DT+P3处理最低;(5)水分和施磷处理的互作效应对植株和籽粒磷含量有显著影响.     

森林生态系统养分循环及其动态模拟研究

养分循环是研究森林生态系统的一个重要部分。国内外学者对森林生态系统的研究有很长的历史,建立了养分的分室模型,经历了森林生态系统养分循环研究从一个静态向动态转变的过程。随着计算机技术的发展,养分循环进入动态模拟阶段,推进了对森林生态系统养分循环的研究。本文综述森林生态系统养分循环的发展概况、养分循环过程及其动态模拟过程,为整体了解森林生态系统养分循环提供帮助。     

动物科学和动物医学专业复合应用型人才培养体系的构建、创新与实践

在动物科学和动物医学专业的教学改革中,以培养学生的实践能力、创新精神和适应社会需求为目标,通过专业课程整合、教学方法改革以及校内外实践实习基地建设等, 实现复合应用型专业技术人才培养体系的构建、创新与实践, 有效地提高2个专业的人才培养质量,得到社会各界的广泛认可。     

分子标记技术在茶树资源与育种中的研究进展

分子标记技术的不断发展为茶树资源与育种研究提供了新的途径,本文综述了RAP]）、AFLP、ISSR、EST—SSR等分子标记在茶树起源与传播、遗传多样性、亲缘关系、遗传图谱构建、性状连锁标记筛选等方面的研究进展。