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During passage of hamster spermatozoa through the epididymis their maturation is shown to involve changes in the sperm head, midpiece (mitochondria) and tail. The sum of these changes results in a dramatic increase in the fertilizing potential of the spermatozoa. When comparable numbers of spermatozoa from the caput or corpus epididymis were injected into one uterine horn of mature females, following ovulation induction, and spermatozoa from the cauda epididymis were injected into the contralateral horn, no fertilization was observed with caput epididymal spermatozoa, 1.7% of oocytes were fertilized by corpus epiddymal spermatozoa, whereas 79.5% fertilization was obtained with cauda epididymal spermatozoa. Total sperm numbers increased from caput to corpus to cauda [28.3 ± 12.2, 40.6 ±20.8, 1434 ±62 mihon, respectively]. The percentage of progressively motile spermatozoa increased from 27.9 ±6.4 to 33.8 ± 4.8 to 70 ± 10.7 during this passage. Viability, measured by exclusion of the dye, propidium iodide, was significantly less in spermatozoa from the cauda than from the proximal or mid-caput epididymis. The percentage of the live cells that were stained intensely by rhodamine-123 (a measure of mitochondrial membrane potential) increased during epididymal passage from 22.8 ±7.8% in the proximal caput epididymis to 57.2 ± 16.5% in the cauda epididymis. Staining with acridine orange (a measure of DNA packaging in the sperm head) indicated an increase in chromatin condensation in cauda epididymal spermatozoa, when compared to those obtained from the caput or corpus.  相似文献   
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摘要:包装内气氛与包装材料选择性透气性是影响果蔬气调包装质量的主要因素。对青豌豆采用6组不同初始气体组分、3种包装材料进行气调包装,在5℃,相对湿度85%的环境下贮藏7d后,测定青豌豆的相关质量指标,并与未包装产品进行比较,结果表明气调包装对青豌豆保鲜效果显著;在此基础上,用主成分分析法构造了气调包装产品质量的综合评价模型,对气调包装青豌豆质量进行综合评价,得出青豌豆气调包装的最佳初始气体组分,分析了不同包装材料对青豌豆气调包装质量的影响。  相似文献   
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Summary Techniques and protocols are described for the generation of genetically modified cells that can be used for gene therapy. Primary fibroblast cultures are established from skin biopsies, maintained in culture, frozen for long-term storage, and retrieved when necessary. Retroviral packaging cell lines are generated by transfection of DNA into retroviral packaging cells by calcium-phosphate precipitation method or by lipofection method. To generate cell lines expressing high titer virus, individual colonies of cells are cloned and the virus titer is determined. Virus collected from packaging cells expressing high titer virus is then used to infect primary fibroblasts. To obtain fibroblast cell lines expressing high amounts of transgenes, individual cells can be cloned to generate clonal cell lines. Although the methods described here are for fibroblasts, the same methods or modification of the methods can be used for other cell types.  相似文献   
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Annamalai P  Rao AL 《Virology》2005,338(1):96-111
To begin elucidation of the relationship between Brome mosaic virus (BMV) replication and encapsidation, we used a T-DNA-based Agrobacterium-mediated transient expression (agroinfiltration) system in Nicotiana benthamiana leaves to express either individual or desired pairs of the three genomic RNAs. The packaging competence of these RNAs into virions formed by the transiently expressed coat protein (CP) was analyzed. We found that in the absence of a functional replicase, assembled virions contained non-replicating viral RNAs (RNA1 or RNA2 or RNA3 or RNA1 + RNA3 or RNA2 + RNA3) as well as cellular RNAs. By contrast, virions assembled in the presence of a functional replicase contained only viral RNAs. To further elucidate the specificity exhibited by the functional viral replicase in RNA packaging, replication-defective RNA1 and RNA2 were constructed by deleting the 3' tRNA-like structure (3' TLS). Co-expression of TLS-less RNA1 and RNA2 with wt RNA3 resulted in efficient synthesis of subgenomic RNA4. Virions recovered from leaves co-expressing TLS-less RNA1 and RNA2 and either CP mRNA or wt RNA3 exclusively contained viral RNAs. These results demonstrated that packaging of BMV genomic RNAs is not replication dependent whereas expression of a functional viral replicase plays an active role in increasing specificity of RNA packaging.  相似文献   
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葡萄籽提取物的质量标准   总被引:4,自引:0,他引:4  
概述了国际市场上葡萄籽提取物的几种质量标准,综合分析了中国葡萄籽提取物各生产厂家的质量标准情况。鉴于国内还没有葡萄籽提取物质量的国家标准或行业标准,笔者根据多年的葡萄籽提取物研究、生产、出口情况,结合相关文献,提出了建立2种规格质量标准的观点:多酚含量大于95%、单体含量大于10%作为高品质葡萄籽提取物的质量标准;原花青素值大于95、单体含量大于6%作为一般品质葡萄籽提取物的质量标准。  相似文献   
8.
药品包装材料对液体药剂质量的影响   总被引:7,自引:0,他引:7  
目的:探讨药品包装材料与用药安全的关系。方法:参考有关文献并结合我国实际情况进行分析。结果:药品包装材料质量对人体能产生一定的危害,对药品质量也产生一定的影响。结论:应按药品的理化性质选用合适的药品包装材料,药品包装材料生产企业也要按专业标准化生产药品包装材料,以适应各种药品包装的需求。  相似文献   
9.
Control of food spoilage is a critical concern in the current world scenario, not only to ensure the quality and safety of food but also to avoid the generation of food waste. This paper evaluates a dual-sensor strategy using six different pH indicators stamped on cardboard for the detection of spoilage in three different foods: beef, salmon, and strawberries. After function validation and formulation optimizations in the laboratory, the halochromic sensors methyl orange and bromocresol purple 2% (w/v) were stamped on cardboard and, in contact with the previously mentioned foods, were able to produce an easily perceptible signal for spoilage by changing color. Additionally, when it comes to mechanical characterization the inks showed high abrasion (>100 cycles) and adhesion resistance (>91%).  相似文献   
10.
中药上市后安全性医院集中监测技术规范(征求意见稿)   总被引:2,自引:5,他引:2  
为了推动中药药品生产企业开展药品重点监测工作,积极响应国家食品药品监督管理总局发布的相关工作指南具有重要意义。因此,该技术规范在经过多次专家论证后,现公开征求意见,旨在为中药上市后安全性再评价监测研究真实报告不良反应/事件并进行客观评价提供技术支撑。该技术规范围绕中药上市后监测的关键环节进行阐述,目的是对大样本、观察性医院集中监测方案设计与实施;采用巢式病例对照设计对"过敏反应的发生特征及机制进行深入研究"的设计与实施进行指导。  相似文献   
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