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关键词： 二酰基甘油转移酶   生物学功能   多态性  

摘要： 二酰基甘油酰基转移酶(DGAT,EC2.***.1.20)是一种微粒体酶,与脂肪代谢、脂类在组织中的沉积有很大关系,它的主要作用机制是使二酰甘油加上脂肪酸酰基形成三酰甘油。DGAT在细胞甘油代谢中起根本性的作用,并在高等真核生物甘油三酯代谢途径如肠脂肪吸收、脂蛋白集合、脂肪形成和泌乳中发挥着重要的功能,提示DGAT不仅是调控甘油三酯与脂肪酸之间的关键因子,而且可能在动物脂肪沉积中起着关键的调控作用。

关键词： 农产品   分析   饲料   动物   细菌纲   组分   培养基   定义   测定   粪便   食品检验   食品   食品测试   调查方法   分析方法   微生物分析   微生物学   沙门氏菌属   抽样方法   测试   试验   验证  

标准号: NF V08-013/A1-2007

摘要： Le présent document spécifie une méthode de recherche des Salmonella spp. dans les matières fécales d'animaux et les échantillons d'environnement au stade de la production primaire.

关键词： eutrophication   fragmentation   GIS   grazing marshes   habitat suitability   invertebrates   niche   ordination  

摘要： Three gastropods in the UK red data book (RDB) occupy drainage ditches on threatened grazing marshes. Segmentina nitida, Anisus vorticulus and Valvata macrostoma are affected by habitat loss, ditch management and eutrophication, but dispersal and fragmentation effects have also been postulated. We used landscape ecological approaches to examine such effects on these and 17 other gastropods on four English marshes, specifically combining ordination to identify suitable habitat with spatially-explicit analysis of occupancy. Among all gastropods, the occupancy of suitable habitat declined significantly as the distance to the nearest occupied site increased. S. nitida and A. vorticulus were among the species most affected, with median nearest distances from occupied to unoccupied suitable sites significantly greater by 3 - 4X than distances between occupied sites. V. macrostoma was not limited locally by dispersal, but was absent from three out of four marshes with suitable habitat. Eutrophication (elevated N) had no effects on distances between occupied and unoccupied sites and did not contribute to fragmentation. Although four non-threatened species were apparently also limited by dispersal, only two (Armiger crista;Gyraulus albus) showed some combination of the dispersal effects, low occupancy of suitable habitat (<50%) and small niche extent that characterized RDB species. While dispersal alone cannot explain unfavourable conservation status in these wetland snails, our data support the hypothesis that limited dispersal between (all species) and within marshes (S. nitida and A. vorticulus) affect all three RDB snails in their remaining UK range. Action is required to better understand the population and genetic consequences;to better understand dispersal mechanisms;and to evaluate re-introduction and reinforcement as aids to recovery. The latter could double the existing site occupancy. (C) 2007 Elsevier Ltd. All rights reserved.

关键词： invasive crustaceans   Onychopoda   Ponto-Caspian species   invasion history   risk assessment  

摘要： We review the patterns of recent range expansions and the biology of the invasive Ponto-Caspian predatory onychopod cladocerans: Cercopagis pengoi, Evadne anonyx, Podonevadne trigona, Cornigerius maeoticus and Cornigerius bicornis. Recent invasions of C. pengoi, E. anonyx and C. maeoticus into the Baltic Sea can be attributed to the climate change, facilitating invasibility of the eastern Baltic Sea coastal ecosystems by the warm water Ponto-Caspian species and intensive shipping activities via the Volga-Baltic waterway (European "northern invasion corridor"). All three species can be considered to be established in pelagic communities of the eastern Gulf of Finland. Only one onychopod species, C. pengoi has invaded the North American Great Lakes via an existing invasion corridor between the eastern Baltic and the Great Lakes. Invasive onychopods may possess adaptive life cycles, switching to early gamogenetic reproduction which enables their establishment in recipient ecosystems and further dispersal. Analysis of temperature and salinity ranges of the Ponto-Caspian onychopod species in native and invaded habitats, indicates that they are potentially able to form populations in a wide range of inland and coastal water ecosystems in temperate zones. Ponto-Caspian onychopods can be considered as "high risk" invasive species, in terms of their potential for range expansion and impact on recipient ecosystems.

关键词： 硒   生物学功能   硒中毒  

摘要： 硒是畜禽生长代谢必需的微量元素之一,适量的硒对畜禽机体的抗氧化,抗病毒,增强免疫力,拮抗其他重金属毒性等有着积极作用,本文综述了硒的来源、需要量、吸收、分布、代谢、生物学功能和过量硒对机体健康的影响,并简要介绍了硒中毒的防治措施。

关键词： 动物保护   减少   精致   代替  

摘要： 2006版"医疗器械生物学评价-动物保护要求"国际标准规定了在用于评价医疗器械的材料或医疗器械本身的生物相容性的动物试验中,爱护动物和使用动物的最基本要求。目的在于:为进行医疗器械生物学评价的委托者,设计者以及进行试验或从动物试验进行推测、评价的科研人员,提供尊重生命的通用性要求;也推荐并提供以下指南:促进今后进一步"减少(reduction)"应用动物全部的数量;"精致(refinement)"在动物中减少或除去痛苦或苦恼的试验方法;以及其他的合乎科学、有效的不需要动物的方法来"代替(replacement)"动物试验。该标准适用于在除人类之外的脊椎动物体上进行医疗器械或材料的生物相容性试验。

关键词： 磁化水   生物学效应   动物   微生物   人体  

摘要： 探讨了磁化水的生物学效应，简述了磁化水对微生物、低、高等动物的生长发育和生殖的影响，对人体的生理作用。对其在动脉粥样硬化的调节、治愈结石症、自由基代谢、医疗保健、抗菌消炎、促进细菌生长等方面的作用进行了分析。

关键词： 反刍动物   瘤胃酸中毒   微生物学   防治  

摘要： 瘤胃酸中毒是集约化养殖反刍动物的重要营养代谢病,给反刍动物养殖业造成了巨大的经济损失。在临床诊断上应注意对瘤胃酸中毒与瘤胃积食、瘤胃臌胀进行症状鉴别诊断。防治瘤胃酸中毒的瘤胃微生物途径包括两个方面:一方面促进乳酸的利用,如添加电子受体、乳酸利用菌以及酵母和曲霉等真菌;另一方面减少乳酸的产生,如给反刍动物接种牛链球菌和乳酸菌疫苗。通过调控乳酸利用菌群和乳酸产生菌群之间的平衡,控制乳酸的利用和产生,阻止瘤胃酸中毒的发生。

关键词： 教学策略   生命活动   新课程标准   动物   生物学   高中   激素调节   神经调节  

摘要： 在“稳态与环境”模块中，动物生命活动的调节包括神经调节和激素调节。本文将从学习目标、教学策略和建议等方面，谈谈对本单元的教学构思。

关键词： 鼻咽癌   移植瘤   动物模型  

摘要： 目的研究并优化建立鼻咽癌移植瘤动物模型的成熟方法,观察移植瘤的肿瘤生物学特性。方法采用免疫组化(SP)法,对鼻癌细胞株CNE-2对数生长期瘤细胞爬片行EB病毒潜伏膜蛋白2A(LMP-2A)免疫组化检测。对数生长期瘤细胞,分别以5×105/0.2ml,1×106/0.2ml,2×106/0.2ml,4×106/0.2ml及肿瘤组织接种于裸小鼠右侧前肢肩背部皮下,观察移植瘤生物学特性,并取肿瘤行常规病理切片及LMP2A免疫组化检测。结果BALB/c裸小鼠接种CNE-2细胞后,2×106/0.2ml组和4×106/0.2ml组移植瘤成功,3周左右接种部位皮下出现肉眼可见的瘤体肿块,逐渐增大,约4周进入加速期,其致瘤成功率为83.3%;瘤块包埋的裸鼠移植瘤成活率100%,无潜伏期,成功率显著高于另两组(P<0.01)。经病理及免疫组化证实移植瘤成功。病理提示肿瘤长至直径约1.0cm以上时,瘤体中央见坏死区域。结论皮下接种CNE-2细胞成瘤的难易与肿瘤细胞浓度成正相关,2～3×106/0.2ml的肿瘤细胞接种是较为理想的浓度。当肿瘤直径为0.5～0.8cm大小时进行干预研究是理想时机。