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《嘉应学院学报》2017,(8):31-36
在低温条件下利用Al诱导结晶在绝缘衬底上生长高晶体质量的多晶Ge薄膜.使用厚度为1~10 nm的Ge插入层可以改善多晶Ge薄膜的生长条件,Ge插入层放置在Al层的下方.使用Ge插入层的目的是提高Ge原子在Al层中的超饱和浓度.Ge插入层可以在275°C的低温下产生Al诱导结晶.Ge插入层可以导致较高的成核率,厚度大于3 nm的Ge插入层可以产生大量的Ge晶体小颗粒,厚度为1 nm的Ge插入层可以促使多晶Ge薄膜快速生长,并产生直径为100μm的Ge晶体大颗粒.从电子背散射衍射(EBSD)测量中可知,Al诱导结晶生长的多晶Ge薄膜具有良好的(111)晶向. 相似文献
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本文对影响谷氨酰胺结晶的一些因素(如Gln浓度、溶液温度、pH、乙醇浓度等)进行了试验。结果表明,在较高Gln浓度、较低温度(4℃)、pH5.6,以及糖、蛋白质等杂质较少的条件下,可获得较高产量和质量的G1n结晶。试验还证明,温和的搅拌有助于结晶的形成和生长,乙醇浓度高也易于产生较大量的Gln沉淀。 相似文献
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在应用高分辨电子显微技术测定蛋白质晶体结构中,由于蛋白质晶体对辐射损伤的敏感性和真空损伤等原因,使蛋白质晶体高分辨成象困难且有别于通常的高分辨成象.本文应用光学衍射方法,对蛋白质晶体高分辨成象条件进行了测定和分析. 相似文献
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营养盐对小球藻生长及胞内蛋白质含量的影响 总被引：2，自引：0，他引：2
微藻含有的蛋白质、糖蛋白等活性物质具有许多重要的生物活性和生理功能.在24～26℃、自然光照的条件下,首先考察小球藻生长与胞内蛋白质积累的关系,其次利用正交设计实验考察不同浓度的营养盐对小球藻生长及胞内蛋白质含量的影响.结果表明,小球藻中蛋白质的合成与积累主要发生在生长过程的平衡期.利于小球藻生长的营养盐的优化组合为:C6H12O6:2g/L,KNO3:0.8g/L,Na2PO4:0.2g/L,细胞的最大密度为6.46×107个细胞/L培养液.获得最高蛋白质含量的营养盐的优化组合为:C6H12O6:6g/L,KNO3:1.6g/L,NaH2PO4:0.2g/L,与之对应蛋白质含量为:655.4mg/g.此结果为进一步从微藻中获取单一组成的,具有重要生物和生理活性的蛋白质及糖蛋白提供了优化培养微藻的实验依据和规模化生产的基础条件. 相似文献
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介绍了用于晶体衍射研究和NMR研究的蛋白质自动化生产的步骤,这些步骤包括建立克隆和表达载体,蛋白质的表达,蛋白质纯化,蛋白质质量控制和NMR或晶体衍射方法的选择. 相似文献
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贵刊 2 0 0 2年第 1期刊出了《“晶体的制备”实验分析》(以下简称《制备》) ,文中比较了几种硫酸铜大晶体制备的实验条件 ,拜读后很受启发。我对实验中涉及的几个重要操作条件进行了正交实验分析 ,得出的实验结果 ,较好地解决了这些实验问题。有些结论与《制备》相符 ,有些结论明显不符 ,提出来与原文作者探讨并供读者参考。1 结晶原理在化学工业领域 ,结晶是一项非常重要的单元操作 ,用于制备高纯度和漂亮外观的产品。结晶与溶质在溶剂中的溶解度和结晶过程中的操作方式等有关 ,溶液的过饱和度是结晶的主要动力。硫酸铜晶体属三斜晶系 ,… 相似文献
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Juliana FELGUEIRAS Joana Vieira SILVA Margarida FARDILHA 《Journal of Zhejiang University. Science. B》2014,15(1):16-42
Prostate cancer （PCa） incidence and mortality have decreased in recent years. Nonetheless, it remains one of the most prevalent cancers in men, being a disquieting cause of men＇s death worldwide. Changes in many cell signaling pathways have a predominant role in the onset, development, and progression of the disease. These include prominent pathways involved in the growth, apoptosis, and angiogenesis of the normal prostate gland, such as an- drogen and estrogen signaling, and other growth factor signaling pathways. Understanding the foundations of PCa is leading to the discovery of key molecules that could be used to improve patient management. The ideal scenario would be to have a panel of molecules, preferably detectable in body fluids, that are specific and sensitive biomarkers for PCa In the early stages, androgen deprivation is the gold standard therapy. However, as the cancer progresses, it even- tually becomes independent of androgens, and hormonal therapy fails. For this reason, androgen-independent PCa is still a major therapeutic challenge. By disrupting specific protein interactions or manipulating the expression of some key molecules, it might be possible to regulate tumor growth and metastasis formation, avoiding the systemic side effects of current therapies. Clinical trials are already underway to assess the efficacy of molecules specially designed to target key proteins or protein interactions. In this review, we address that recent progress made towards under- standing PCa development and the molecular pathways underlying this pathology. We also discuss relevant molecular markers for the management of PCa and new therapeutic challenges. 相似文献
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通过分析基因进化过程,以＂融合＂蛋白产生新功能或新蛋白质为实例,总结出蛋白融合的相关规则,规则包括协同作用、联合作用、多功能组合、多聚体组合和结构域重组等,根据这些规则设计了一个融合蛋白辅助筛选系统,用于融合蛋白规律的探讨以及为蛋白改造和设计提供辅助方案. 相似文献
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以单链随机寡核苷酸序列为文库,通过指数富集配体系统进化技术（systematic evolution of ligands by exponential enrichment,SELEX）能够获得与靶标特异性结合的核酸适体,这是一类新型的分子识别探针,其与靶标的亲和力可以同抗原抗体相媲美,甚至优于抗原抗体的结合。核酸适体广泛应用在生化分析、疾病诊断、药物研发等领域。该文将介绍核酸适体的筛选和特点以及核酸适体在生物分子检测、疾病的诊断和治疗中的应用,最后介绍核酸适体在神经系统疾病研究中的应用。 相似文献
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Folin-酚试剂法蛋白质定量测定 总被引：16，自引：0，他引：16
罗芳 《黔南民族师范学院学报》2005,25(3):46-47,72
蛋白质分子在碱性条件下，与酚试剂作用生成蓝色化合物，其颜色深浅与蛋白质含量成正比，根据这一原理，用比色法对蛋白质的浓度进行定量测定。 相似文献
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盛懿 《广东广播电视大学学报》2013,(4):109-112
通过神经网络进行信息筛选,可实现计算机对信息的筛选,从而把管理者从繁琐的信息筛选工作中解脱出来。在系统的设计过程中,首先标准化企业数据样本,根据数据建立系统理论模型;然后通过神经网络理论分析和训练模型,并确定模型的相关参数与结构形式;最后对模型进行仿真。通过该模型,用户可根据自身的需要建立信息筛选系统。 相似文献
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The influence of water on protein conformation was investigated by simulating the molecular dynamics of a model protein lysozyme in different water systems.The lysozyme-water system with TIP3P water model and lysozyme-water cluster system with six-ring water model were evaluated.In addition,the radial distribution function of solvent around lysozyme was calculated.It is found that the distribution of water molecules around lysozyme is similar to that of water clusters.The analyses of dihedral angles and disulfide bonds of lysozyme show that the conformation of lysozyme is severely damaged in the lysozyme-water cluster system compared with that in the lysozyme-water system.This difference can be attributed to the formation of larger number of intermolecular hydrogen bonds between lysozyme and water cluster.It is in agreement with the analysis that water clusters can change the degree of denaturation in the process of heat denaturation of lysozyme. 相似文献
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目的 :了解不同水平的蛋白质日粮对实验大鼠生长发育、繁殖性能的影响。方法 :用三种不同蛋白质水平的日粮饲喂实验大鼠 ,观察其生长发育、繁殖性能并测量相关数据。结果 :饲喂高蛋白配方大鼠其体重、平均日增重及料重比等指标极显著 (P <0 .0 1 )或显著 (P <0 .0 5)高于低蛋白配方组和中等水平蛋白配方组。结论 :实验大鼠在生长发育高峰期可喂以高蛋白日粮 ,之后喂以中等水平蛋白质日粮 ,既可保证动物质量 ,亦可获得较好的经济效益 相似文献
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网络成瘾会对青少年健康成长产生多方面影响,造成极大危害。基于网络成瘾症的临床表现及初中生的认知特点,并参阅相关网络成瘾调查问卷等资料编制的量表,适合青少年的年龄特点。通过采用此量表对上海市初中生进行的问卷调查表明,该量表具有较好的内在一致性信度及准则关联效度,是测查初中生网络成瘾的有效工具,可用于青少年网络成瘾症的筛查和预防。 相似文献
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6-aminopenicillanic acid (6-APA) crystals obtained under different physical and chemical conditions of the solutions may present different habits. The habits of diamond-shaped plates are desirable compared with other habits of 6-APA crystals. To obtain ideal 6-APA crystals, the effects of the mixed solvents and additives on 6-APA crystal habits were investigated. Ethanol or acetone was used as the organic solvent, and impurities existing in the ,6-APA purification process were used as the additives. 6-APA growth habits were changed when the concentrations of ethanol, acetone or phenyl acetic acid were increased to exceed their critical concentration. The observed results show that the dominant face on 6-APA crystals was identified to be , {020}, but the overall habit was controlled by the relative growth rates of the : 101 and {002} faces. Crystal growth rates and habits can be appreciably changed by specific adsorption of additives on crystal faces. In some cases solvent molecules can act in a similar way and may be regarded as bulk additives. The effects of additives and organic solvents on 6-APA crystal habits were the results of adsorption effect,which fitted the experimental results quite well. 相似文献