水稻磷脂酶A活性测定方法的研究

为了优化水稻磷脂酶A活性测定方法,研究了多种因素对水稻磷脂酶A活性的酸碱滴定测定方法的影响.结果表明水稻磷脂酶A活性酸碱滴定法测定的适宜条件为:起始pH8.0,反应温度40℃,20.0 mL底物,4.0mL酶的粗提液,提取缓冲液的体积与叶片样品重量的比值(mL/g)为2.5,反应时间7h.     

PLA沙障防风效益研究

为了解新材料PLA沙障对近地表气流的影响,通过测定铺设PLA沙障沙丘距地表不同高度的风速,并以铺设麦草沙障沙丘及裸沙丘为对照,对比研究各种规格、迎风坡、坡顶及背风坡地表粗糙度、风速效能及风速廓线差异。     

鸡PLA2基因的克隆与原核表达及PLA2蛋白卵黄抗体的制备

【目的】克隆并原核表达鸡PLA2基因,小量制备鸡PLA2卵黄抗体,为大规模制备PLA2卵黄抗体作为饲料添加剂提供参考。【方法】提取鸡胰脏总RNA,利用RT-PCR方法获得鸡PLA2基因,将其克隆至pGEX-4T-1原核表达载体中,构建表达载体pGEX-4T-1-PLA2,转入大肠杆菌BL21(DE3),IPTG诱导表达GST-PLA2融合蛋白。将GST-PLA2融合蛋白免疫青年蛋鸡,每次0.3mg/只,共免疫4次,收集鸡蛋,提取卵黄抗体,采用West-ern Blotting检测抗体的特异性。【结果】成功克隆出了鸡PLA2基因,构建了pGEX-4T-1-PLA2原核表达载体,并诱导表达了分子质量为44.59ku的GST-PLA2融合蛋白。GST-PLA2融合蛋白免疫蛋鸡后获得了卵黄抗体,经West-ern Blotting检查,制备的卵黄抗体具有很好的特异性。【结论】构建了表达鸡PLA2基因的表达系统,并成功的制备了抗鸡PLA2的卵黄抗体。     

Calcium nutrition affects cold hardiness,yield, and fruit disorders of apple and pear trees 1

Foliar sprays of calcium chloride (CaCl₂) and to a lesser extent, soil applications of calcium nitrate [Ca(NO₃)₂] fertilizer, increased calcium (Ca) concentrations in leaves and fruit of apple, (Malus domestica) and pear (Pyrus communis L.) trees. For most years, CaCl₂ sprays or Ca(NO₃)₂ fertilizer increased cold hardiness of ‘Anjou’ pear trees, and reduced the incidence of fruit disorders (alfalfa greening and cork spot of pears and bitter pit of ‘Delicious’ apples). Yield of ‘Anjou’ pears was usually increased with the higher rates of nitrogen (N) fertilizers [ammonium nitrate (NH₄NO₃), Ca(NO₃)₂, or urea]. Calcium chloride sprays increased yield of ‘Anjou’ pears if it was applied over many years.     

PLA沙障对土壤硬度的影响

 为了解新材料聚酯纤维(PLA)沙障对沙丘土壤硬度的影响,通过测定铺设PLA沙障沙丘表层的土壤硬度,并以铺设麦草沙障沙丘及裸沙丘为对照,对比研究各种规格、迎风坡、坡顶及背风坡土壤硬度的差异。结果表明:铺设PLA沙障沙丘表层土壤硬度显著高于麦草沙障沙丘(P<0.001),且2者土壤硬度均显著高于未铺设沙障的裸沙丘(P<0.001);2 m×2 m和1 m×1 m PLA沙障土壤硬度比较接近,均显著小于3 m×3m规格的(P<0.01),而麦草沙障3种规格的土壤硬度差异较小;2种沙障所在沙丘不同部位土壤硬度变化趋势相似,均是迎风坡的最大,坡顶次之,背风坡的最小;PLA沙障及麦草沙障单个障格内的土壤硬度分布都是不均匀的,并且二者的土壤硬度分布规律存在差异。     

伊维菌素聚乳酸微球制备条件的优化及药物含量测定

用乳化溶剂挥发法制备了伊维菌素聚乳酸微球。试验采用Ｌ１８（３＾７）正交设计,以微球粒径分布为主要优选水平,结合微球收率和包裹率,筛选出最佳制备条件：连续相为２０ｇ．Ｌ＾－１的聚乙烯醇（ＰＶＡ）水溶液;分散相为ＰＬＡ（Ｍｒ８．２万,投量２．０ｇ）和ＩＶＭ原料药（０．６７或１．００ｇ）溶于２５ｍＬ二氯甲烷;搅拌速度为４５０ｒ．ｍｉｎ＾－１,在３７℃恒温下搅拌１２ｈ挥干二氯甲烷,过滤收集微球。所得微球干     

Polymer-Based Electrophoretic Deposition of Nonwovens for Medical Applications: The Effect of Carrier Structure,Solution, and Process Parameters

Hyaluronate and alginate are non-toxic and biocompatible polymers, which can be used for surface modification and functionalization of many kinds of materials. Electrophoretic deposition (EPD) has several advantages, including its versatility, simplicity, and ability to coat substrates with complex shapes, and is used for the creation of antimicrobial or hydrophobic coatings on metallic biomaterials, among other applications. However, its utilization for applying biopolymer layers on textiles is very limited due to the more complex structure and spatial characteristics of fibrous materials. The aim of this research was to analyze the effects of selected EPD process parameters and the structural characteristics of fibrous carriers on the kinetics of the process and the microscopic characteristics of the deposited layers. The influence of solution characteristics, process parameters, and carrier structures obtained using two different techniques (melt blown and spun-bonded) were analyzed. The morphology and structure of the created deposits were analyzed using scanning electron microscopy and computed tomography, and molecular structure analysis was performed with Fourier Transform Infrared spectroscopy. The surface mass and thickness of fibrous poly (lactic acid)-based carriers were analyzed in accordance with the respective standards. This study serves as a basis for discussion and further development of this method with regard to fibrous materials for medical applications.     

部队医院图书馆“一卡通”使用情况评析

结合解放军第309医院图书馆管理系统将图书借阅卡合并到医院“一卡通”的使用情况,分析了医学图书馆“一卡通”的作用,以及需注意的问题。     

丹顶鹤“表演”驯化实用技术研究

为探讨丹顶鹤“表演”驯化实用技术．的基础上，从雏、幼鸟开始，根据动物“印记”以现代动物行为学和条件反射理论为指导，在对丹项鹤的生态生物学特征、行为学特点研究行为特点，建立驯养人员和驯化对象的“亲和力”，进行丹顶鹤的定向“表演”驯化。经长期的“表演”驯化，丹顶鹤可具有呜叫、舞蹈、飞翔、伏卧等4种“表演”技能。“非条件反射...     

仿生增强制备聚乳酸基骨组织工程复合材料

依据仿生原理制备了纳米羟基磷灰石聚乳酸(nHA-PLA)复合的骨框架材料.此复合材料中的主要成分是纳米羟基磷灰石,纳米相的羟基磷灰石就是天然骨中主要的无机相.在保持高孔隙率(90%)的同时,复合材料的抗压性能达到2.07 MPa,高于单纯的聚乳酸框架材料(为0.89 MPa).分离成骨细胞并在三维框架材料上培养,用扫描电镜进行观察,复合材料具有很好的细胞贴附性能.仿生制备的三维纳米羟基磷灰石聚乳酸复合骨框架材料,无论从结构还是性能上,都是骨组织工程中的优选材料之一.