9 resultados para Maux de tête

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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我们提出了一种新颖的利用脉冲重复率倍增和时域泰伯效应实现毫米波脉冲信号产生的光学方法。在我们的方案中,一个级联的马赫振德干涉仪被用来实现脉冲重复率倍增,一个线性的啁啾光纤光栅被用来实现时域泰伯效应。文中对这种方法的基本理论进行了分析,并给出了相应的数值模拟的结果。研究结果显示这种灵活的毫米波脉冲信号产生的方案在未来的宽带的Radio over Fiber技术将有一个很好的潜在的应用。

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Although spermatozoa from several species of nonhuman primates have been cryopreserved, there has been no report of success with rhesus macaque spermatozoa as judged by functional assays. Two Tris-egg yolk freezing media. TEST and TTE. which have: been successfully used for cynomolgus macaque (Macaca fascicularis) spermatozoa, were compared for cryopreservation of spermatozoa From four rhesus macaques (Macaca mulatta). The postthaw motility (percentage and duration) of spermatozoa cryopreserved in TTE was much higher than that for spermatozoa cryopreserved in TEST. The function of sperm cryopreserved in TTE was evaluated by in vitro fertilization or oocytes collected from gonadotropin-stimulated prepubertal rhesus macaques. Of the inseminated oocytes. 82 +/- 13% were fertilized and 63 +/- 22 and 39 +/- 21% of the resulting zygotes developed into morulae and blastocysts. respectively. These results indicate that rhesus macaque spermatozoa can be effectively cryopreserved in TTE medium. This finding will facilitate the application of in vivo and in vitro assisted reproductive technologies in this species. (C) 2001 Academic Press.

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Many fluorescent probes excited by visible light have been used to assess sperm quality by flow cytometry. Developing a viability evaluation method using UV excited stains would be useful for multiparameter analysis of sperm function. This investigation was conducted to determine the efficacy of Hoechst 33342 (H342) and propidium iodide (PI) dual staining for evaluating rhesus monkey sperm viability through use of flow cytometry and excited by a single UV laser. The results showed that the live cells stained only with H342 strongly correlated with expected sperm viability, and flow cytometric analyses were highly correlated with fluorescence microscopic observation. Using H342/PI/SYBR-14 triple staining method, it was found that the live/dead sperm distributions were completely concordant in both H342/PI and SYBR-14/PI assays. In addition, this dual staining was extended with fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) to simultaneously analyze viability and acrosome integrity of sperm cryopreserved using two different extenders, TTE and TEST, and indicated that TTE offered better Preservation of plasma and acrosome integrity than TEST Therefore, the H342/PI dual staining provides an accurate technique for evaluating viability of rhesus monkey sperm and should be valuable for multiparameter flow cytometric analysis of sperm function.

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以稀释液TTE (382 mOsm/ kg) 为对照, 研究了5 种渗透压(688 、389 、329 、166 、43 mOsm/ kg) 的TEST 稀释液(TEST、mTEST1、mTEST2、mTEST3、mTEST4) 在冷冻过程中对猕猴精子功能的影响。精液一 步稀释于含甘油的防冻液中, 甘油的终浓度为5 % (v/ v) 。在冷冻前后分别检测精子的运动度和质膜完整性, 后者用Hoechst 33342 和碘化丙锭双色标记流式细胞术分析。结果表明: 冷冻之前, 与鲜精相比, 用TEST 和 mTEST4 稀释的精子运动度和质膜完整性显著降低( P < 01001) , 其余组中除mTEST2 稀释的精子质膜完整性显 著降低( P < 0105) 外, 精子运动度无差异; 冷冻复苏后, TTE、mTEST3 和mTEST1 冻存精子的运动度和质膜 完整性最高, 其次是mTEST2 , TEST和mTEST4 冷冻效果最差( P < 0105) 。提示等渗、适当高渗或低渗的稀释 液适合猕猴精子的冷冻保存; 对精子产生高渗毒害作用是导致猕猴精子用TEST 冷冻存活率低的主要原因。

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TTE或TEST防冻液在冻存猕猴精子时产生不同结果,其主要不同在于防冻液中糖成分的不同。实验结果表明,冷冻复苏过程对精子结构产生了影响,TTE法低温保存的猕猴精子的头部的质膜出现少许皱褶或泡化现象,但精子的顶体、核或是精子尾部的结构与鲜精的结构基本相似。猕猴精子经TEST法低温保存后,大部分精子结构则发生了明显的变化,精子膜、顶体和精子核明显泡化、损伤或破裂,精子尾部不能分辨出正常的超微结构。这提示,可能由于TTE防冻液中复杂的糖成分在降温/复苏过程对精子起到了较好的协同冷冻保护作用;而TEST防冻液中单一的糖成分不能完全保护精子避免低温损伤,低温保存过程破坏了精子的结构,并影响了复苏后精子体外存活能力与受精能力。

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The effects of three amino acids (proline, glutamine, and glycine) added to the freezing medium Tes-Tris-egg yolk (TTE) for cryopreservation of cynomolgus monkey (Macaca fascicularis) spermatozoa were studied. This is the first report on the effects of amino acids on nonhuman primate sperm cryopreservation. The addition of 5 mM proline, 10 mM glutamine, and 10 or 20 mM glycine each significantly improved post-thaw sperm motility and membrane and acrosome integrity compared with the control (TTE alone). However, a significant decrease in motility and membrane/acrosome integrity was observed when amino acid concentrations increased to 60 mM for proline and glutamine, and 80 mM for glycine. The results suggest that adding a limited amount of amino acids to the freezing media is beneficial for freezing cynomolgus monkey sperm.

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The cryoprotective effects of 11 different extenders, TTE, DM, mDM, LG-DM, G-DM, TCG, TEST, TSM, Test-M, Test-H, and LM, on sperm cryopreservation of cynomolgus monkey (Macaca fascicularis) have been compared with glycerol as cryoprotectant. Sperm motility, plasma membrane, and acrosomal integrity were examined to evaluate frozen-thawed sperm function. The results showed that TTE, DM, mDM, LG-DM, G-DM, and TCG exhibited the best and similar protective efficiencies for cynomolgus monkey sperm cryopreservation in terms of sperm motility and plasma membrane integrity (P > .05). The acrosomal integrity for spermatozoa cryopreserved in TCG was statistically lower than that of TTE, DM, mDM, LG-DM, and G-DM (P < .05) but was significantly higher than that of TEST, TSM, Test-M, Test-H, and LM (P < .05). The postthaw sperm motility for 5 other extenders (TEST, TSM, Test-M, Test-H, and LIVI) did not exceed 30%, and the 3 sperm parameters evaluated for them were significantly lower than that of TTE, DM, mDM, LG-DM, G-DM, and TCG (P < .05). On the basis of these findings, 5 commonly used permeating cryoprotectants, glycerol, ethylene glycol, dimethyl sulfoxide, acetamide and propylene glycol have further been tested for their effectiveness on sperm cryopreservation in extenders of TTE, DM, mDM, LG-DM, G-DM, and TCG. The results showed that the sperm cryoprotective efficiencies of glycerol and ethylene glycol were similar and best among 5 permeating cryoprotectant treatments (P > .05). Dimethyl sulfoxide or acetamide resulted in average cryoprotection for cynomolgus monkey spermatozoa: poorer than glycerol or ethylene glycol but better than that of propylene glycol (P < .05). In addition, the action of permeating cryoprotectant appeared to be independent of extenders. The results in the present study demonstrate that 1) TTE, DM, mDM, LG-DM, G-DM, and TCG are excellent extenders and suitable for cynomolgus monkey sperm cryopreservation; 2) the mechanism of action of permeating cryoprotectants are not affected by extender composition; 3) ethylene glycol has a similar cryoprotective efficacy to glycerol that makes it a successful cryoprotectant for sperm cryopreservation in cynomolgus monkeys.

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Ejaculated spermatozoa from cynomolgus monkeys and rhesus monkeys were frozen in straws with six different extenders (TTE, DM, mDM, LG-DM, G-DM, and TCG) containing glycerol. Sperm motility and head membrane and acrosomal integrity were evaluated after fr

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精液的冷冻保存对家畜繁殖、人类辅助生殖以及濒危物种保护有着重要意义。然而目前精子冷冻的研究很大程度上是经验性的,并且要使用含卵黄、脱脂乳等复杂成分的稀释液。这些复杂成分不仅是潜在的污染源,也使精子冷冻中的质量控制及分析特定物质的功能变得困难。即便如此也仅有约50%的精子能够存活下来,而且存活精子的受精能力也有所下降。称猴是生物医学研究中使用广泛的灵长类动物,开展赫猴精子的冷冻保存有利于该物种的繁殖并促进基础胚胎学的研究,成功的称猴精子冷冻方法还可以为其它珍稀濒危灵长类动物所借鉴。但是目前成功的称猴精子冷冻的报道仍然很少,且精子质量检测方法并不完善。因此本文致力于建立简单有效的称猴精子冷冻方法和活率检测方法。主要结果如下:1)建立了一种用单一紫外激光同时激发Hoechst33342和碘化丙锭结合流式细胞术检测称猴精子活率的有效方法,并将此方法用于称猴精子冷冻研究。2)发现甘油的一步加入或去除与分步加入或去除对称猴精子冷冻效果没有明显影响,在此基础上发现各种糖类稀释液之间的作用差异很小,但不含糖的化学成分确定的TT稀释液对精子冷冻保护作用显著高于糖类稀释液。这可能是因为TT的渗透压(138mOsm/kg)较好地适合于猫猴精子的冻存,高渗毒害作用可能是导致称猴精子用TEST冷冻存活率低的重要原因。3)以TT为基础稀释液,探讨了精子冷冻中一些关键因素,以期进一步改进冷冻方法。结果表明精液一步稀释于含5%甘油的一倍浓度TT,平衡0.5h可得到最佳效果,总体上复苏精子的运动度可达到55%以上,质膜完整性能达到6D%左右。这种方法与传统的以含有卵黄的TTE为稀释液的称猴精子冷冻方法效果相当,复苏精子还能够成功地进行体外受精。另外,用液化精液1:2直接稀释于防冻液还能进一步提高冷冻效果。本研究建立的用化学成分确定稀释液冷冻称猴精子的简单方法,有利于提高称猴精子的冻存效率,并有助于分析特定成分在精子冷冻中的作用。而Hoechst33342和碘化丙锭双染方法,是一种简单有效的精子活率检测方法,并在多参数精子功能的流式检测中有很高应用价值。