共查询到19条相似文献,搜索用时 109 毫秒
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神经病靶酶活性测定(NTE)是目前筛选有机磷化合物迟发神经毒性能力的唯一生化试验方法。我国现阶段研究中多采用经典的Lowry氏法测定被检生物样品中的蛋白含量,据以推算NTE活性,其操作费时、复杂,不适于大样本检测。Bradfordf提出用蛋白—染料复合物试验较Lowry氏方法快速而且灵敏,最低检出量为2ug。为此,我们就这一方法本身从几个方面做了探讨。 相似文献
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蛋白质测定是食品等检验中的常规项目 ,国家标准中蛋白质的检验方法 (GB 5 0 0 9 5 -85 )是用硫酸铜和硫酸钾作催化剂 ,以凯氏定氮法来测定其含量。用硫酸铅和硫酸钾作催化剂消化样品 ,存在着消化时间长这一缺点。为此我们对催化剂作了改进 ,选用过氧化氢作为强氧化剂和催化剂 ,结果报告如下。1 原理过氧化氢 (H2 O2 )作为强氧化剂和催化剂 ,其反应原理大致为过氧化氢 (H2 O2 )在强氧化剂硫酸 (H2 SO4)及高温的作用下放出新生态氧 (O) ,使食品中有机物分解 ,放出CO2 、SO2 、NH3 及各种无机元素 ,NH3 和H2 SO4结合生成 (NH4) 2 S… 相似文献
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蛋白质定量分析与进展 总被引:2,自引:0,他引:2
蛋白质是组成人体重要的成分之一 ,是生命的物质基础。与营养、细胞结构、酶、激素、病毒、免疫、物质运转、遗传、生命的起源和进化都有着密不可分的关系。蛋白质对肝脏、肾脏、胶体浸透压、水肿等都起调节作用 ,人体的神经和生理功能、大脑的兴奋与抑制 ,都离不开蛋白质的支持。因此 ,蛋白质的定量分析涉及到生产与科研的各个领域及生命有关的各个行业 ,是生物学科、食品检验及掺假掺伪〔1〕、临床检验、诊断疾病〔2〕、药物分离提纯和质量检验中最常用的手段。本文就蛋白质的定量分析及进展作一综述。1 凯氏定氮及分光光度法蛋白质分子… 相似文献
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食品中蛋白质的测定常选用国家标准《食品卫生检验方法·理化部分(一)》(GB/T5009.5-2003)中第一法凯氏定氮法,该法繁琐费时。参考有关资料,通过实验发现用十二烷基硫酸钠(SDS)直接滴定酸化稀释后的奶粉中的蛋白质,方法简便且与凯氏法测得结果无显著差异。1原理当SDS溶液缓慢滴入蛋白质溶液时,在酸性介质中,可溶性蛋白质会突然沉淀出来,且SDS的消耗量与蛋白质含量成正比。2试剂2.1 2g/LSDS溶液称取干燥24h的SDS 20.00g用蒸馏水溶解,并定容至1000m l。2.2 0.1 mol/L盐酸2.3标定用的试剂与仪器同凯氏法3方法吸取奶样1.00 m l~2.00 m l… 相似文献
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<正>英国研究人员日前报告说,他们发现一种使人衰老的蛋白质,在心脏病发病过程中起着重要作用,这将有助于研发治疗心脏病的新途径。英国伦敦国王学院等机构研究人员在新一期美国《循环》医学期刊上报告说,以前研究曾发现名为"A型核纤层 相似文献
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目的:建立一种牛奶及奶粉中蛋白质的快速测定方法。方法:在试管中以双氧水-硫酸加热,快速消解牛奶及奶粉中的蛋白质,使用纳氏试剂比色法测定。结果:快速消解只需5分钟即可完成。两个品种牛奶中蛋白质各测定8次,相对标准偏差分别为3.9%和1.3%,用甘氨酸标准溶液做回收试验,回收率99.4%。用本法测定奶粉标准物质(GBW10017)6次,与标准值比较结果无显著性差异。结论:该方法操作简单,结果可靠。 相似文献
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TJ6:一种与妊娠相关的蛋白质 总被引:1,自引:0,他引:1
本文综述了近年来发现的一种与妊娠相关的细胞因子TJ6。TJ6完善蛋白分子量约为70kd,由两部分组成:一个是由7个跨膜区域组成的TJ6m蛋白,并包含有羧基末端,分子量约为50kd;另一个是膜外可溶性的N-末端肽TJ6s,分子量约为20kd。在妊娠期间TJ6可作为一种免疫调节因子发挥作用。TJ6在胸腺、脾、蜕膜和胎盘等组织中有丰富表达。此外,在妊娠期间外周血中,若TJ6在B(CD19)细胞上有高表达 相似文献
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目的探讨同时口服给予两种示踪剂1-13C-亮氨酸和α-15N-赖氨酸测量人体蛋白质需要量,结果是否一致。方法选取20名健康青年女性作为研究对象,预设6个膳食蛋白质水平,3个连续的实验周期,在每个实验周期给予日常膳食6d,在D7持续口服13C-亮氨酸和15N-赖氨酸4h,收集给予同位素过程中的静脉血、呼出气和尿液样本。测定血浆、呼出气和尿液中的13C、15N的丰度,计算13C-亮氨酸和15N-赖氨酸的氧化率,建立二项回归曲线计算蛋白质的需要量。结果通过13C-亮氨酸计算的蛋白质需要量是0.92 g/kg/d,无法通过15N-赖氨酸的氧化率建立二项回归曲线求得蛋白质需要量。结论口服途径以15N-赖氨酸作为示踪剂,不能较好的反映蛋白质摄入量的变化情况。 相似文献
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Sinacore JM Connell KJ Olthoff AJ Friedman MH Gecht MR 《Evaluation & the health professions》1999,22(2):221-234
A method for measuring interrater agreement on checklists is presented. This technique does not assign individual scores to raters, but computes a single agreement score from the concordance of their check mark configurations. An overall coefficient of agreement, called phi, is derived. The agreement coefficient that is expected by chance and the statistical significance of phi are determined by statistical simulation. Despite the dichotomous nature of the checklist agreement (raters either agree or disagree on items), we show that the binomial distribution does not provide a means for testing the statistical significance of phi. A medical education study is used to illustrate the phi methodology. 相似文献
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Lipscomb IP Sihota AK Botham M Harris KL Keevil CW 《The Journal of hospital infection》2006,62(2):141-148
Hospital sterile service departments (SSDs) currently rely on simple visual confirmation of cleanliness as an assessment of the efficacy of cleaning surgical instruments. The inherent inability to monitor low levels of infectious or proteinaceous contamination on surgical instruments creates the possibility that highly dangerous and robust biological agents may remain infectious and undetected even after standard cleaning and sterilization procedures have been employed. This paper describes the development of a novel microscopy technique, episcopic differential interference contrast microscope, combined with the fluorescent reagent, SYPRO Ruby, to rapidly detect brain tissue protein to below 400 pg/mm(2) on an instrument surface. This technique has displayed a minimum level of detection observed by 50% of volunteers of 85 pg/mm(2) (95% confidence intervals 67-112 pg/mm(2)). Quantitative assessment of instruments supplied from various SSDs enabled the establishment of a 'contamination index' of both proteinaceous and non-proteinaceous deposits on the surface. This new methodology for the assessment of surface contamination is generally applicable and should facilitate future quantitative surveys of instrument contamination in hospitals and other healthcare environments. 相似文献
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The isolation of Fusobacterium necrophorum present in small numbers in heavily contaminated material such as faeces or soil is hampered by the lack of an efficient selective medium and by the high minimum infective dose of the organism. A sensitive method for the detection and isolation of faecal strains of F. necrophorum type A was based on the subcutaneous injection of faeces, suspended (5% w/v) in broth culture of Actinomyces (Corynebacterium) pyogenes or Staphylococcus aureus to increase fusobacterial infectivity, into mice pretreated with clostridial antitoxins. When necrobacillosis developed F. necrophorum was identified microscopically in tissue from the advancing edge of the lesion and isolated on a partly selective medium. The enhancement of fusobacterial infectivity produced by A. pyogenes and by S. aureus was high, but the latter was slightly the more efficient, enabling as few as 80 F. necrophorum organisms/g of faeces to be detected. Use of the method showed that 3 of 16 wallabies had F. necrophorum in their faeces at the time of examination. Numerous epidemiological applications are suggested. 相似文献
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微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质 总被引:1,自引:0,他引:1
目的:建立简便、准确、绿色的食品中蛋白质的批量测定方法。方法:利用微波溶样技术处理样品,并与乙酰丙酮和甲醛显色定量。结果:微波消解-乙酰丙酮甲醛分光光度法与国标凯氏定氮法相比测定结果差异无显著性,该方法线性范围在5~100μg/10 m l,相关系数r=0.9997,检出限为0.546μg/10 m l,相对标准偏差(RSD)为1.29%~2.21%,加标回收率93.3%~103%。结论:微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质方法简便、试剂用量少且环保,方法具有较好的准确度和精密度,适合于批量蛋白质样品的测定。 相似文献