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羊毛是一种很有价值的资源,具有许多优良特性,如弹性好、吸湿性强、不易沾污、保暖、耐磨、光泽柔和等,但也存在缩绒性、穿着针刺感等不足,使羊毛织物的洗后尺寸不稳定、湿膨胀性、以及贴身穿着时对皮肤产生刺痒感等。为了充分发挥羊毛纤维的优点,毛纺工业及该领域的研究者们在挖掘羊毛价值方面进行着不懈的探索,采州各种方法对羊毛进行处理,以改善和约会补纤维性能的不足,赋予 相似文献
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在美国男性中,前列腺癌是最常诊断和位列第二致死率的肿瘤,一生患癌的危险概率约为1/6。前列腺组织是由胚胎泌尿生殖窦(urogenital sinus, UGS)发展形成的一个导管-腺上皮结构,这种导管-腺上皮结构是由高柱状的分泌性的腺细胞和扁平的基底细胞组成,这两种细胞分别表达特异性的细胞角蛋白(cytokeratin, CK)和生物学标记。在大量的前列腺癌研究中发现许多癌基因和抑癌基因存在突变,但是它们在前列腺癌发生和发展中的作用机制还不明确。目前,尚缺乏对正常人前列腺上皮组织如何转变为前列腺癌的分子机制的深入研究。人前列腺癌体外和体内模型的综合应用有助于研究前列腺癌的形成和分子、细胞生物学特征,目前迫切需要建立一些新的来源于手术新鲜组织标本并能表现不同的肿瘤生物学特性的永生化细胞系作为转化医学研究新的实验工具。 相似文献
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Keratinase production and keratin degradation by a mutant strain of Bacillus subtilis 总被引:2,自引:0,他引:2
A new feather-degrading bacterium was isolated from a local feather waste site and identified as Bacillus subtilis based on morphological, physiochemical, and phylogenetic characteristics. Screening for mutants with elevated keratinolytic activity using N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis resulted in a mutant strain KD-N2 producing keratinolytic activity about 2.5 times that of the wild-type strain. The mutant strain produced inducible keratinase in different substrates of feathers, hair, wool and silk under submerged cultivation. Scanning electron microscopy studies showed the degradation of feathers, hair and silk by the keratinase. The optimal conditions for keratinase production include initial pH of 7.5, inoculum size of 2% (v/v), age of inoculum of 16 h, and cultivation at 23 ℃. The maximum keratinolytic activity of KD-N2 was achieved after 30 h. Essential amino acids like threonine, valine, methionine as well as ammonia were produced when feathers were used as substrates. Strain KD-N2,therefore, shows great promise of finding potential applications in keratin hydrolysis and keratinase production. 相似文献
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