交联酶聚集体制备中钙离子的结构调控作用

以葡萄糖氧化酶(GOx)为研究对象,系统地研究了钙离子对交联酶聚集体(CLEA)粒子尺寸和微观结构的调控作用以及酶催化性能和实用性的影响。研究结果表明,GOx酶沉淀过程中引入钙离子可显著降低CLEA粒子尺寸并导致粒子内纳米孔道结构逐步消失。在0.1 mmol/L钙离子浓度下,GOx酶的CLEA仍保有清晰的纳米孔道结构。以葡萄糖为底物的GOx酶CLEA催化结果显示,该CLEA粒子的酶活性为对照CLEA粒子的2.69倍。即便1.0 mmol/L钙离子浓度下制备的CLEA粒子的GOx酶活性仍高出对照CLEA粒子约42%。此外,0.1 mmol/L钙离子浓度下制备的CLEA不仅具有更高的底物转化速率和很好的操作稳定性,而且CLEA中GOx酶的最大反应速度显著提高。这些实验结果明确了钙离子对CLEA粒子尺寸和微观结构的调控作用,为制备具有高效生物催化活性的CLEA粒子奠定了基础。     

适于癌基因表达数据集的新特征提取标准NFEC及其分类新算法研究

癌基因表达数据集具有小样本、高维数之特点,一般的机器学习机难以对其有效分类。因此,通常需要采用某些特征提取度量标准来进行降维处理。可是常用的一些特征提取度量标准亦会导致分类效果欠佳之问题。依据微分容量控制学习机DCCM,提出了一个新的特征提取度量标准NFEC,然后依据NFEC和DCCM,提出了适于癌基因表达数据集的特征提取算法DCCFE。实验表明,新的度量NFEC和新的特征提取算法DCCFE较之现有方法对癌基因表达数据集分类时更为有效。本文的工作意义在于:(1)提出了一个新的更有意义的特征提取度量标准;(2)DCCM可以采用比核函数更为一般的一阶可微函数,因而提出的新的特征提取算法更具普遍应用意义。     

Subfamily of submaxillary gland-specific Mup genes: chromosomal linkage and sequence comparison with liver-specific Mup genes

Mouse major urinary proteins (MUPs) are encoded by a family of ca. 35 genes that are expressed in a tissue-specific manner in several secretory organs; in the liver, in the submaxillary, sublingual, parotid and lachrymal glands, and in the skin sebaceous glands. In this paper we describe the isolation of a Mup gene, Mup-1.5a, which is expressed predominantly in the submaxillary gland of BALB/c mice. We show that Mup-1.5a is a member of a subfamily consisting of two closely related genes, both of which are closely linked to the Mup-1 locus on mouse chromosome 4. Mup-1 is the locus of a class of Mup genes (Group 1) expressed in the liver. The complete nucleotide sequence of Mup-1.5a has been determined, and was compared to a previously sequenced Group 1 Mup gene. The comparison shows that the differentially expressed Mup genes are uniformly divergent in exons, introns and in their flanking sequences. The regions of homology extend at least 5 kb into the 5' flanking region of Mup genes.     

实验性脾虚证大鼠内分泌腺形态学与细胞化学研究

成年Ｗｉｓｔａｒ大鼠２０只,分对照组和实验组。实验组用大黄煎剂灌服４２天致实验性脾虚证。对两组睾丸,肾上腺和甲状腺进行常规形态学与细胞化学观察。形态学显示：睾丸,肾上腺和甲状腺的组织和细胞均有不同程度的损伤。细胞化学显示：各内分泌腺均表现酸性磷酸酶（ＡＣＰ）减弱,个别内分泌腺细胞显示琥珀酸脱氢酶（ＳＤＨ）,三磷酸腺苷酶（ＡＴＰａｓｅ）和ＰＡＳ反应的变化。结果证明脾虚证不仅消化系统功能低下,而且内分泌功能也受到了影响     

Transmission in near‐infrared optical windows for deep brain imaging

Near‐infrared (NIR) radiation has been employed using one‐ and two‐photon excitation of fluorescence imaging at wavelengths 650–950 nm (optical window I) for deep brain imaging; however, longer wavelengths in NIR have been overlooked due to a lack of suitable NIR‐low band gap semiconductor imaging detectors and/or femtosecond laser sources. This research introduces three new optical windows in NIR and demonstrates their potential for deep brain tissue imaging. The transmittances are measured in rat brain tissue in the second (II, 1,100–1,350 nm), third (III, 1,600–1,870 nm), and fourth (IV, centered at 2,200 nm) NIR optical tissue windows. The relationship between transmission and tissue thickness is measured and compared with the theory. Due to a reduction in scattering and minimal absorption, window III is shown to be the best for deep brain imaging, and windows II and IV show similar but better potential for deep imaging than window I.

     

灰茶尺蛾核型多角体病毒某些生化特性的研究

灰茶尺蛾核型多角体病毒某些生化特性的研究李彦章,石正丽,陈棣华（中国科学院武汉病毒研究所,武汉４３００７１）关键词灰茶尺蛾,核型多角体病毒,结构多肽,限制性内切酶图谱灰茶尺蛾核型多角体病毒（Ｅｃｔｒｏｐｉｓｇｒｉｓｅｓｃｅｎｓｎｕｃｌｅａｒｐｏｌｙｈ...     

利用植物激素调控嫁接形成的初步研究

利用黄瓜（Ｃｕｃｕｍ ｉｓｓａｔｉｖｕｓ）试管苗进行离体茎段自体嫁接,研究ＩＢＡ 和６－ＢＡ 对嫁接形成的影响时发现：进行离体茎段嫁接时,用试管苗茎段可简化嫁接过程,减少污染。嫁接茎段的颜色变化、不定根发生和愈伤组织形成与激素浓度有关。植物激素通过影响砧木和接穗间维管束桥形成的时间和数目调控嫁接组合的发育。在作者的实验中,最佳的激素条件是：在接穗培养基中加ＩＢＡ １．２ ｍ ｇ／Ｌ,在接穗和砧木培养基中加６－ＢＡ ０．３ ｍ ｇ／Ｌ。