木素过氧化物酶合成的部分影响因素

研究了黄孢原毛平革菌（Ｐｈａｎｅｒｏｃｈａｅｔｅｃｈｒｙｓｏｓｐｏｒｉｕｍ）在以０．４％微晶纤维素为碳源、２０ｍＭＮＨ＋４氮源的富碳富氮液体振荡培养条件下,木素过氧化物酶与起始ｐＨ值、诱导剂、孢子年龄、添加吐温及碳源设置的关系。试验结果显示,起始ｐＨ值６．０所得酶活最高,黎芦醇诱导效果明显。添加吐温、少量单糖可明显提高酶产量。     

受阻胺光稳定剂的热失重分析

使用热失重分析仪对ＴＭＰ,ＰＭＰ,ＴＭＰＭ,ＧＷ５４０,Ｔｉｎｕｖｉｎ７７０等小分子型受阻胺光稳定剂、ＴＭＰＭ的均聚物ＰＴＭＰＭ和ＰＭＰＭ的均聚物ＰＰＭＰＭ、一系列具有不同单体配比的ＰＤＳ,ＴＭＰＭ和ＰＭＰＭ分别与ＭＭＡ,Ｓｔ,ＭＡＡ,ＡＡ共聚得到的共聚物等受阻胺类光稳定剂进行了热失重分析（ＴＧ）。实验发现小分子型的受阻胺光稳定剂的热稳定性均较差,它们的热稳定顺序是ＴＭＰ〈ＰＭＰ〈ＴＭＰＭ〈ＧＷ５     

烷基胺对盐类矿物捕收性能的溶液化学研究

根据溶液化学计算,确定了不同碳链长度的烷基胺形成沉淀的临界pH值及其与无机阴离子生成胺盐的顺序为WO_4~(2-)>SO_4~(2-)～PO_4~(3-)〉〉F~-～CO_3~(2-)。浮选实验结果表明,阳离子捕收剂浮选盐类矿物的临界pH值上限对应于生成胺沉淀的临界pH值。烷基胺浮选盐类矿物的捕收能力大小顺序为白钨矿>重晶石～磷灰石>萤石～方解石,与胺和相应矿物阴离子生成胺盐的顺序一致。动电位测定表明,烷基胺使带负电的盐类矿物表面ξ-电位变正,使带正电的萤石表面ξ-电位增加。因而,烷基胺浮选盐类矿物的作用机理主要归因于胺与矿物阴离子生成胺盐。无机阴离子对盐类矿物的胺浮选起活化作用。     

伯胺N1923萃取Re(Ⅶ)的研究

用平衡法研究了伯胺 N1923的正辛烷溶液从氯化物介质中苹取铼(Ⅶ),其反应方程式为RNH_3Cl_((0))+ReO_4~-RNH_3ReO_4_((0))+Cl~-求得 Kex=10~(1.08)。运用 ReO_4~-离子选择电极作检测手段,用恒界面搅拌法研究了该苹取体系的动力学。结果表明,苹取反应机理是两步界面反应RNH_3Cl_(i)+ReO_4~-RNH_3ReO_(4(i))+Cl~-RNH_3ReO_(4(i))+RNH_3Cl_((0))RNH_3ReO_(4(0))+RNH_3Cl_((i))用计算机模拟方法求出了各 k 值。     

有机胺制碱的碳化过程及其数学模型

通过理论分析和合理简化,确定了碳化过程及其控制步骤,并提出了“液-液相界面反应-扩散”模型。以50(v)%叔胺～50(v)%正丁醇作为有机溶液,相比为2∶1,CO_2流量50.0 L/h,转速600r/min,初始NaCl浓度为5.42mol/L,用线性回归得到碳化速度为(相关系数>0.95):     

Characterization of threerice CCoAOMT genes

Caffeoyl-Coenzyme A 3-O-Methyltransferase (CCoAOMT) is a key enzyme in lignin biosynthesis pathway. Three rice CCoAOMT genes were identified and designated as OsCOAI, OsCOA20 and OsCOA26. OsCOAI contains four exons and three introns, while the other two have three exons and two introns. The deduced amino acid sequences of these rice genes share a high identity (75.43%) with other plant CCoAOMT proteins and contain the CCoAOMT specific motifs. Phylogenetic analysis indicates that OsCOAI has the closest evolutionary relationship to maize CCoAOMT. In contrast, OsCOA20 and OsCOA26 belong to another clade.Northern blot analyses and in situ hybridization studies indicate that the three rice CCoAOMT genes are highly expressed in developing sclerenchyma cells and vessel bundles of young leaves, suggesting that they are probably involved in constitutive lignification.     

Obtaining the transgenic poplars with low lignin content through down-regulation of 4CL

The antisense 4CL (4-coumarate: CoA ligase)gene was transformed into triploid Chinese white poplar(Populus tomentosa) mediated by Agrobacterium tumefaciens.PCR and Southern blot analysis indicated that antisense 4CLgene had been integrated into the genome of the transgenicChinese white poplars. The antisense gene had also beenexpressed, which was indicated by RT-PCR and Westernanalysis. Klason lignin content assay showed that repressionof 4CL expression could result in remarkable reduction oflignin content in transgenic poplars, with most reduction of 41.73% compared with that of wild type in this paper. Butthere is no significant difference in holocellulose content be-tween trans- genic and wild poplars. We considered that 4CLmight not be the metabolism control point between ligninand carbohy- drate biosynthesis. The stems of transgenicpoplars displayed red-brown color with different levels afterthe bark was peeled, while those of untransformed plantswere white. No visible differences in growth and developmentwere observed between transgenic and wild plants. Wiesnerreaction analysis of the transgenic plant stems with reducedlignin content exhibited red color, while that of untrans-formed plant was typically purple-red.     

β内酰胺类抗生素的合理应用

目的 为临床正确选用β内酰胺类抗生素及制订治疗方案．了解β内酰胺类抗生素的抗菌机制，影响β内酰胺类抗菌作用的因素，以及耐药机制．方法 通过介绍各类β内酰胺类抗生素的抗菌谱、抗菌作用及临床药理学特性，正确使用β内酰胺娄抗生素．结果 根据疾病和药物的适应症，正确选用药物，既要考虑疗效，又要确保医疗安全，合理使用β内酰胺抗生素，切忌滥用．结论 充分发挥杀菌活性强、毒性低的优点，合理应用，达到防治感染性疾病的目的．     

以2,5-二(苯并咪唑亚甲基)环二肽为桥以二(2-苯并咪唑亚甲基)胺为配体的Zn(Ⅱ)双核配合物的合成和量化计算

合成了二(2-苯并咪唑亚甲基)胺及其副产物的混合配体与Zn( )的双核超氧化物歧化酶模型化合物,并对其进行了元素分析、紫外和红外表征;采用X射线衍射方法对其晶体结构进行了测定;以晶体结构数据为依据,采用HF方法在LanL2DZ基组下对桥连双锌配合物的配位正离子进行量子化学计算,结果表明,标题配合物的电子结构有利于该配合物呈现清除超氧阴离子自由基(O2-·)的生物功能.     

转基因抗虫棉花木质素含量及其生物合成关键酶活性研究

通过盆栽试验,以不同转基因抗虫棉花及其亲本对照为供试对象,研究木质素含量及其生物合成关键酶活性.结果表明:与非转基因棉花比较,在蕾期及铃期,转基因抗虫棉花Z30,CCRI41,SGK321叶片、茎秆组织中的木质素含量及叶片内的苯丙氨酸解氨酶和过氧化物酶活性发生了一些变化,但其显著性改变仅特异性地发生在某些品种、某些组织或某些时期内.在蕾期,转Bt基因棉花Z30茎秆组织中的木质素含量比其常规棉对照Z16显著下降,幅度达34.96%;转CpTI-Bt棉花CCRI41茎秆组织和SGK321叶片组织中的木质素含量比其常规棉对照显著下降,幅度分别为27.15%,13.22%.所有供试转基因抗虫棉花的木质...