Analysis of ATPase and succinic dehydrogenase in F1 hybrids of rice (Oryza sativa L.)

Summary Activities of ATPase and succinic dehydrogenase were assessed in three F₁ hybrids of rice and their parental lines during boot leaf stage, flowering, on 10th and 20th days after flowering. ATPase activity showed increase at the flowering and on 20th day after flowering. Succinic dehydrogenase activity continued to rise till 10th day after flowering and declined on 20th day after flowering. Hybrids with high yield were generally endowed with more positive heterosis for these two enzymes. Correlation coefficient of grain yield per panicle was significantly positive with ATPase activity at all the stages studied. Heterosis for ATPase activity might serve a reliable criterion for the selection of efficient F₁ combinations.     

Vapor phase reaction of wood with maleic anhydride (II): mechanism of dimensional stabilization

The vapor phase reaction of wood with maleic anhydride (MA) was investigated from the aspect of the mechanism of dimensional stabilization. Notably the existence of cross-links was examined by detailed analyses of dimensional stability and related properties, diffuse reflectance infrared Fourier transform (DRIFT) spectra, and changes in mechanical properties such as creep property and vibrational property. Higher reaction temperature resulted in less leaching of reagent. Also a peak in DRIFT spectra at 1730 cm⁻¹ showed the esterification of wood components with MA, while that at around 1780 cm⁻¹, which became remarkable with increasing reaction temperature, suggested the formation of cross-linking. The loss tangent decreased and the creep deformation was restrained for the specimens treated at high temperature. From these results it is plausible that MA mainly forms monoester with wood components at lower temperature; however, at elevated temperature cross-linking appears in addition to formation of the monoester.     

Chemical modification of wood: A short review

For most markets for wood, it is used without any treatments or modifications. When wood is used in adverse environments, it may be treated with chemicals to help prevent decay, improve water resistance, reduce the effects of ultraviolet radiation or increase fire retardancy. Many of these treatments involve the use of toxic or corrosive chemicals that can harm the environment. Chemical modification of wood provides an alternative by providing protection against water, decay, UV and thermal degradations by bonding chemicals to the cell wall polymers that do not leach out. Dimensional stability and decay resistance are two major properties that can be greatly improved by simple reactions with acetic anhydride.     

桐油酸酐酰亚胺环氧树脂耐热性研究

以桐油、双马来酰亚胺、马来酸酐及环氧树脂为基本原料,合成了具有较好耐热性的桐油酸酐酰亚胺环氧树脂.重点讨论了不同原料,如桐油、马来酐、双马来酰亚胺及环氧树脂的用量、固化反应温度及固化反应时间等因素对树脂耐热性的影响.当桐油、双马来酰亚胺、马来酐和环氧树脂的质量比为1∶0.25∶0.2∶0.4,150 ℃烘烤5 h固化时,所得树脂具有较好的耐热性,温度指数(T20000)可达160.8 ℃.     

伊维菌素聚酯酸酐微球的制备

将2种聚酯酸酐（P（SA：RA20：80）,P（SA：RA30：70））分别与伊维菌素溶于三氯甲烷中作为有机相,以聚乙烯醇水溶液为水相,用乳化溶剂挥发法制备出2种伊维菌素聚酯酸酐微球。采用光学显微镜考察所制备微球的形态及粒径,紫外分光光度法测定载药量和包封率。结果显示,制备出的P（SA：RA30：70）／IVM微球的平均粒径为（72．240±24．747）μm,载药量为19．67％,包封率为87．70％。P（SA：RA20：80）/IVM微球的平均粒径为（64．18±26．14）μm,载药量为17．72％,包封率为87．27％。这表明采用乳化溶剂挥发法成功制备出2种伊维菌紊聚酯酸酐微球。     

交联辛烯基琥珀酸淀粉酯微球对阿司匹林的吸附性能研究

采用反相微乳法制备交联辛烯基琥珀酸淀粉酯微球,利用红外光谱、粒度分析仪、扫描电镜和X射线衍射仪对微球进行表征,研究微球对阿司匹林的吸附性能,采用单因素固定变量法探讨投药量、交联剂用量、反应时间对吸附量的影响。结果表明:原淀粉已成功酯化交联合成变性淀粉微球,微球平均粒径为42.61μm,粒径在80μm以下占93.7%;微球表面粗糙多孔,外观圆整,由原淀粉颗粒的晶体形态变为无定性态;在交联剂用量1.5 g,反应时间3.5 h,投药量22 mg的最佳制备条件下,微球的载药量达到21.48%,包封率达到97.63%,可以作为一种优良的阿司匹林吸附载体。     

抗球虫药莫能菌素钠盐半抗原的改造

生产中制备的莫能菌素以钠盐形式存在,没有直接与选用的载体蛋白偶联的基团,因此不能直接用于免疫原的合成,必须加以改造形成含羧基的物质才能偶联,合成免疫原以便生产抗体。本实验采用三种方法将莫能菌素钠盐改造成含羧基的莫能菌素酸及莫能菌素-琥珀酸酐衍生物,为建立免疫检测方法提供基础。     

苊烯完全抗原的制备与鉴定

为制备免疫原性较好的苊烯完全抗原,以3-苊烯丁酸(ACE)为原料,分别采取活化酯法和混合酸酐法与牛血清白蛋白(BSA)和鸡卵清白蛋白(OVA)偶联,制备免疫原和包被原,经非变性聚丙烯酰胺凝胶电泳和紫外光谱吸收法鉴定偶联结果。足垫免疫BALB/C小鼠,间接ELISA检测血清效价。结果表明:BSA(OVA)、过程载体、BSA(OVA)-ACE在Native-PAGE中迁移率发生明显改变,紫外光谱扫描发现3种物质在最大吸收峰处波长发生明显偏移,表明2种方法制备的苊烯完全抗原偶联成功。间接ELISA检测血清效价最高为1∶256 000,可以进行苊烯单克隆抗体的制备。