35 resultados para Bull semen


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Aim: To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender. Methods: Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris (mTTE) synthetic extender and glycerol as cryoprotectant. The effects of glycerol concentration (1%,3%, 5%, 10% and 15% [v/v]) and its equilibration time (10 min, 30 min, 60 min and 90 min) on post-thaw spermatozoa were examined by sperm motility and sperm head membrane integrity. Results: The post-thaw motility and head membrane integrity of spermatozoa were significantly higher (P < 0.05) for 5% glycerol (42.95 +/- 2.55 and 50.39 +/- 2.42, respectively) than those of the other groups (1%: 19.19 +/- 3.22 and 24.84 +/- 3.64; 3%: 34.23 +/- 3.43 and 41.37 +/- 3.42; 10%: 15.68 +/- 2.36 and 21.39 +/- 3.14; 15%: 7.47 +/- 1.44 and 12.90 +/- 2.18). The parameters for 30 min equilibration (42.95 2.55 and 50.39 2.42) were better (P < 0.05) than those of the other groups (10 min: 31.33 +/- 3.06 and 38. 98 +/- 3.31; 60 min: 32.49 +/- 3.86 and 40.01 +/- 4.18; 90 min: 31.16 +/- 3.66 and 38.30 +/- 3.78). Five percent glycerol and 30 min equilibration yielded the highest post-thaw sperm motility and head membrane integrity. Conclusion: Cynomolgus monkey spermatozoa can be successfully cryopreserved in a chemically defined extender, which is related to the concentration and the equilibration time of glycerol.

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P>Semen sample was collected from two captive adult Yangtze finless porpoises (Neophocaena phocaenoides asiaeorientalis) during physical examination. One individual was aged about 9 years with body length 143 cm (total length) and body weight 46.1 kg in 2003. The age of the other was unknown and its body length was 147 cm and body weight was 43 kg in 2004. Ultrastructure of their spermatozoa was examined using scanning and transmission electron microscope. The sperm concentration was 4.17 x 10(9) spermatozoa per ml by the cytometer. The approximate dimensions of the spermatozoa were as follows: head length, 3.366 +/- 0.140 mu m (mean +/- SE, n = 15); head width, 1.896 +/- 0.099 mu m (n = 15); and neck length, 1.004 +/- 0.074 mu m (n = 10). The tail included midpiece, principal piece and terminal piece. The length of the midpiece was 1.882 +/- 0.077 mu m (n = 9). There is no apparent boundary between the principal piece and the terminal piece, so the length of the principal piece and the terminal piece was 44.612 +/- 3.485 mu m (n = 5). Total length of the spermatozoa was 53.314 +/- 4.580 mu m (n = 10). The acrosome covered approximately 45.8% of the anterior portion of the head.

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Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation of Nostoc sphaeroides Kutzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5 10 μ mol.m(-2)&BULL; s(-1) photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different light radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy dependent process.

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为了确定合理环保的耕作制度,2007~2008安塞田间定位试验黄土丘陵旱作农区大豆(Glycine maxL)、玉米(Zea maysL)、红小豆(Semen Phaseoli)、马铃薯(Solanum tuberosumLinn.)在翻耕化肥(CF)、翻耕有机肥(CM)、翻耕无肥(CN)、免耕化肥(NF)、免耕有机肥(NM)、免耕无肥(NN)等水平下的农田土壤脲酶、蔗糖酶活性。结果表明:在作物花期,大豆、玉米土壤脲酶活性较高,蔗糖酶活性较低,而红小豆、马铃薯则与之相反,差异极显著。到作物收获后,玉米土壤脲酶、蔗糖酶活性增高,增幅在83%以上,而马铃薯、红小豆、大豆三种作物土壤脲酶活性降低,降幅在10%以上,蔗糖酶活性增强,增幅在40%以上。从花期到收获后,免耕降低了土壤脲酶活性,提高了土壤蔗糖酶活性,在黄土丘陵沟壑旱作农区两种土壤酶活性表现较优的作物为大豆、玉米,较优的处理为NM玉米、NF大豆,其田间环保效应为:作物生长期间两种酶活性比较高,收获后两种酶活性则降低,有利于提高作物生长期土壤肥效利用率,减少作物收获后温室气体的排放。

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为了探明多年免耕下农田恶性杂草发生的机理,提高保护性耕作下作物对农田恶性杂草持久稳定的抑制效果,依据陕西安塞田间4a的定位试验,采用小区调查取样和室内实验相结合的方法,从物种组成、密度特征、多样性以及相似性特征等方面,研究了黄土丘陵旱作农区大豆(Glycine max)、玉米(Zea mays)、红小豆(Semen Phaseoli)、马铃薯(Solanum tuberosum)在翻耕化肥(CF)、翻耕有机肥(CM)、翻耕无肥(CN)、免耕化肥(NF)、免耕有机肥(NM)、免耕无肥(NN)等水平下的农田土壤种子库。结果表明:(1)4种作物24种土样中共萌发出12个物种1965株幼苗,隶属于7科12属。1年生杂草占94%,棒头草(fugax nees ex steud)、苋菜(Acalypha australis)、马唐(Digitaria sanguinalis)、早熟禾(Poasphondylodes)为优势种,占87%。(2)在0~20cm土层不同处理间,土壤种子库的密度变动于(282.9±63.4)~(7482.5±1078.3)粒.m-2,其中,红小豆小区>马铃薯小区>大豆小区>玉米小区;翻耕小区>免...

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A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3—5) and nine known phenolics (6—14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1—2, 6—7, and 9—11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0—99.0m g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200m g/ml.

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We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.

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本文报道了浙江天目山自然保护区阔叶树上的两种新的心材腐朽病害,其病原菌分别为变孢绚孔菌(Laeti-porus versisporus(Lloyd)Imazeki)和白蜡多年卧孔菌(Perenniporia fraxinea(Bull.:Fr)Ryvarden)。根据野外调查对这两种新病害的症状进行了报道,并根据实地采样对这两种新的病原菌进行了详细描述。

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A simple and convenient protocol for the cryopreservation of the flounder (Paralichthys olivaceus) sperm was established for "on the spot" cryopreservation of large quantities of semen. The use of three cryoprotectants, dimethyl sulphoxide (DMSO), glycerol (Gly) and methanol was tested in the method. The percentage of motile sperm present in semen after it had been frozen and thawed in the presence of DMSO, Gly or methanol was 60.5 +/- 3.6, 79.17 +/- 4.5 and 13.25 +/- 4.7%, respectively. The fertilization rates of this sperm were 67.06 +/- 15.1, 76.20 +/- 10.0 and 44.93 +/- 22.6%, while the hatching rates of eggs fertilized with this sperm were 37.40 +/- 8.3, 48.18 +/- 25.7 and 23.35 +/- 10.8%, respectively. It was found that Gly and DMSO were better cryoprotectants than methanol, with Gly giving the best overall results. Under scanning electron microscopy, it could be seen that while the majority of the frozen-thawed sperm remained morphologically normal, some exhibited lost or dilated mitochondria, swollen mid-pieces, broken tails, or damaged cell membrane, which probably caused the decrease in motility and fertility of the frozen-thawed sperm. (C) 2003 Elsevier Science Inc. All rights reserved.

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当今世界和平与发展是主题,但是危害人民生命财产安全的恶性事件时有发生。特别是2001年美国“9&bull;11”事件后,国际社会恐怖活动更是愈演愈烈。为了满足打击恐怖分子、消除恐怖活动以及保障社会稳定的需要,世界上许多国家相继开发研制了用于反恐战争的机器人。在国内,政府也逐渐加大了反恐防暴的力度,特别是2008年北京奥运会,2010年上海世博会,安全是一项重要的工作,这就迫切需要我国公安和武警部门必须拥有一批能够执行侦查、排除或销毁爆炸物的高技术警用装备,反恐防暴机器人就是其中之一。 反恐防暴机器人属于地面移动机器人中的一种,是集计算机、传感器、驱动、远程通信以及武器控制等技术所构成的高技术产品。它可应用于核工业、军事、燃化、铁路、公安、武警等部门,代替人在危险、恶劣、有害环境中执行探查、排除或销毁爆炸物、抢救人质以及与恐怖分子对抗等任务。 本文主要对沈阳自动化研究所研制的“灵蜥-HW”反恐防暴机器人进行相关的研究与分析。为了研究的方便,把“灵蜥-HW”机器人分成两部分分别进行研究:一部分是采用轮-腿-履带复合移动机构的移动载体,另一部分是固接在移动载体上的5自由度的机械手。本文首先对机械手与移动载体分别进行了运动学建模,并在对机械手运动学建模的基础上,分析了机械手的最大理想工作空间,从而验证了“灵蜥-HW”机器人机械手设计的合理性。其次,对机器人跨越台阶、斜坡、壕沟障碍的越障方式进行了分析;建立了机器人采用腿-履带复合越障方式跨越台阶障碍过程的动力学模型以及机器人自撑起的动力学模型,并分析了电机驱动力矩与机器人速度、障碍物高度以及地面摩擦力之间的关系,为确定机器人在复杂地面环境的适应能力提供了理论依据。最后,采用有限元方法,对机械手以及移动载体的关键零部件进行了分析,确定了各部分的安全系数分布情况,为以后对机器人进行结构优化设计奠定了基础。

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在复杂工程系统的概念设计优化中,高精度数值分析方法得到广泛应用,将高精度数值分析与优化方法有机结合,对设计空间展开全面搜索与寻优,已经成为现代设计优化方法的重要发展方向。以水下滑翔机的概念设计为研究对象,引入代理模型,控制高精度分析试验的数量,有效地化解精度与效率之间的矛盾。将参数化几何建模、网格划分以及流体数值模拟分析集成为自动分析流程,并以此为基础采用试验设计理论,构建代理模型,解决水下滑翔机机翼的多目标设计优化问题。给出基于代理模型的设计优化过程,并系统地比较几种试验设计方法的适应性,重点讨论多项式响应面和径向基函数代理模型,所得代理模型相对误差小于2%。采用梯度寻优方法与遗传算法在给定设计空间内进行全面搜索,获得机翼的最佳平面构形,水下滑翔机的升阻比提高6.76%,俯仰力矩的绝对值由0.2760N&bull;m降低为0.0015N&bull;m,提高水下滑翔机的运动性能。