番茄红素作用机理研究

对番茄红素作用机理的最新研究成果进行了综述。指出番茄红素是类胡萝卜素的一种,它的摄入量以及在人体血液中的含量与多种慢性疾病和癌症的发病率呈负相关。番茄红素独特的分子结构使它具有很多特有的生物化学特性和生理活性。     

叶青双对水稻白叶枯病的光活化研究

叶青双经光照处理２－１６ｈ后,对水稻白叶枯病的活性显著增强。接菌前１天和接菌当时施药,第１０天的抑病效果＞８０％,接菌后１天施药,第１５天的抑病效果达６０％左右,说明光产物不仅有很好的保护作用,叶片内吸后的治疗作用母体显著增强,光产物叶面施用的残效期比母体延长５－７天;根部内吸作用良好,根施１０天报抑病效果达９０％左右。光产物溶液经１年黑暗贮存后仍具有稳定的活性。     

生防菌株对地黄枯萎病的防治效果及其促生作用

从地黄根际土壤中分离到对地黄枯萎病菌有较强抑制作用的B6、B2 1、S15、S5 2、S72、S92、S95、T3和T4等9株生防菌。经盆栽试验和田间小区防治试验,结果表明,S15、S72、S5 2、B6和T4对地黄枯萎病的防效都达到了5 0 %以上,且S5 2、S15和S95对地黄具有明显的促生增产作用,具有较好的开发利用价值。     

Membrane Action in Full Width X-joints SHS Loadedwith In-plane Bending Moments

Based on 'yielding-line' method, in this paper, the static strength of X-joints, SHS loaded with in-plane bending moments is analyzed and two static strength formulas are derived: one considers the membrane action and the another not. This paper can be helpful to researchers of tubular structures.     

兽用非甾体类抗炎药美洛昔康研究现状

美洛昔康作为非甾体类抗炎药(NSAIDs),不仅可广泛用于抗炎、镇痛、解热,还具有安全高效、副作用小、半衰期长等优点。研究显示,此药具有较好的抗炎及解热镇痛作用,无毒或低毒性,在美国已广泛应用于犬、猫等宠物临床疾病治疗。由于目前兽用美洛昔康剂型较为单一,且临床应用靶动物种类较少,因此未来需开发更多种类剂型,同时应增加不同靶动物的临床应用研究。本文对兽用美洛昔康的理化性质、作用机理、药理作用、药代动力学、不良反应和临床应用等方面的研究进行综述,旨在为开发新型的兽用美洛昔康及其临床安全、合理用药提供参考。     

外泌体的生物学功能及其在动物遗传育种中的应用

外泌体是一种广泛存在于多种细胞间质中的囊泡,多种细胞在正常情况下或在细胞外刺激等应激条件下都能产生外泌体,来自不同细胞类型的外泌体作用机制及功能有很大区别。外泌体可通过膜蛋白与靶细胞膜蛋白结合、膜蛋白碎片与细胞膜上受体结合、膜与靶细胞膜直接融合等方式传递生物活性分子,从而参与机体免疫、细胞分化等过程。由于外泌体具有来源天然、穿越屏障能力好、生物相容性强等特点,在许多研究领域均受到广泛的关注。作者介绍了外泌体的形态特点、形成过程、作用机制、分离纯化、生物学特性、功能及应用;总结了近年来外泌体在畜禽研究中的应用。外泌体不仅可应用于动物遗传育种中,还可作为工具或载体来研究动物体内各种生化途径。该综述可为外泌体的相关研究及应用提供参考。     

Unexpected indirect effect of spiders on the rate of litter disappearance in a deciduous forest

Previous experiments in meadow and forest-floor communities have uncovered a negative indirect effect of spiders and other large epigeic predators on decomposition, presumably through depression of densities of microbi-detritivores. We report the results of a 17-month field experiment in a deciduous forest in which spiders exerted the opposite effect on decomposition. In autumn we collected falling leaves of oak (Quercus), maple (Acer) and hickory (Carya), and placed three bags of mixed litter, and three groups of tethered leaves, in 1-m² fenced plots. We determined the disappearance rate of these leaves through April of the second year. Spider densities were reduced by >50% in the spider-removal treatment. The rate of leaf-litter disappearance was not higher in spider-removal plots, but instead was ca. 20% lower (P=0.057). Thus, spider predation clearly was not decreasing the rates of litter decomposition in our experiment; on the contrary, the results suggest that spiders were indirectly enhancing decomposition. Possible hypotheses to explain this unexpected result are discussed.     

Genetic analysis of resistance to Fusarium wilt disease,yield and yield-related traits of pigeonpea (Cajanus Cajan (L.) Millsp.)

ABSTRACT

Understanding the genetic control of Fusarium wilt resistance is crucial in pigeonpea breeding programme. This study aimed to study the gene action controlling Fusarium wilt resistance, yield and yield components and select promising crosses possessing resistance to Fusarium wilt along with important agronomic yield traits. Six lines were crossed with four testers in a line x tester mating design. For Fusarium wilt reaction, F₁’s progenies were evaluated in a sick field having inoculums of Fusarium wilt at one location for two seasons and in a pot as well. The F₁’s and parents were evaluated for yield and yield components at two locations for two seasons using a row-column design with two replications. Results indicated that parents and crosses had highly significantly difference for yield and important agronomic traits. General combining ability (GCA) effects of lines and testers were also significant. Specific combining ability (SCA) was also significant for some crosses. Non-additive gene action was more important than additive gene action except for days to maturity and plant height. Crosses ICEAP 00932?×?TZA 2439 and ICEAP 00932?×?TZA 197 displayed small effects of SCA for Fusarium wilt and large SCA for most of yield traits and should be used for integrated disease management.     

粪肥堆腐中尿囊素含量变化及添加物对其变化的影响

研究粪肥堆腐过程中尿囊素 ( All)含量变化表明 :4种粪肥的变化趋势相同即呈抛物线型 ,但变化的速度不同。加入含氮添加物能显著提高粪肥中 All的含量 ,并在堆腐后期能减缓All的下降速率。研究还表明 ,蛋白质和核酸的变化对 All的含量也有影响 ,通径分析结果 ,蛋白质对 All的累积直接贡献大 ,核酸的直接作用较小 ,两者的间接作用都小