核酸与罗丹明B体系作用的共振散射光谱研究

基于脱氧核糖核酸（DNA）对罗丹明B（RhB）的共振散射的增强效应,拟定了一种新的测定DNA的共振散射法,在pH=0．93的条件下,罗丹明B只有极弱的光散射,但它与脱氧核糖核酸作用后却有强烈的共振光散射作用,在入=298nm处,光散射有最大的散射强度,并且光散射强度与脱氧核糖核酸（DNA）的浓度呈线性关系,线性方程为：I=4．40＋11．28C（mg／L）,线性范围为：O．0128mg／L～8．96mg／L,基于此建立了具有较高灵敏度、操作简单的脱氧核糖核酸测定方法,将该方法用于脱氧核糖核酸人工合成样品的测定,结果满意。     

过渡金属催化的2,3-联烯酸环化合成γ-丁烯酸内酯

γ-丁烯酸内酯是一类具有重要潜在活性的化合物.发展了二价钯催化的2,3-联烯酸和(ω-1)-烯基卤化物的偶联关环反应.反应经过了二价钯催化的氧钯化-碳钯化,重复的去钯氢化/钯氢化及β-脱卤钯化反应.同时还发展了两种联烯之间的二聚环化反应,两分子2,3-联烯酸的反应生成二丁烯酸内酯,2,3-联烯酸与1,2-联烯酮反应则生成呋喃基取代的γ-丁烯酸内酯.     

Production of conjugated linoleic acids by Lactobacillus plantarum strains isolated from naturally fermented Chinese pickles

Naturally fermented pickles harbour many lactic acid bacteria (LAB). Forty-three LAB strains with conjugated linoleic acid (CLA)-producing ability were isolated from three naturally fermented pickle brines. Of these isolates, lp15 identified as Lactobacillus plantarum by API 50 CHL system and full-length 16S rDNA sequence analysis exhibited the highest CLA-producing ability (26.1% conversion) at 48 h in de Man Rogosa Sharpe (MRS) broth in the presence of 100 μg/ml of linoleic acid (LA). Compared to other strains, L. plantarum strain lp15 showed the highest tolerance upon increased levels of LA in the medium, i.e., up to 600 μg/ml. This strain converted about 25% of LA into CLA isomers [predominantly cis-9, trans-11 CLA (9-CLA) and trans-10, cis-12 CLA (10-CLA)], of which 75% was 9-CLA. Interestingly, though the conversion rate of LA into CLA by lp15 remained stable between 100 to 600 μg/ml LA levels in the medium, it dropped sharply at 1000 μg/ml. Taken together, the lp15 strain displayed relatively high LA tolerance with higher conversion rate, which implies that this strain is a valuable candidate for enhancing the CLA content in food-sources like pickles.     

人工饲料蛋白质含量与桑蚕（Bombyx mori）对氨基酸的吸收

本试验用５种脱脂大豆粉和纤维素粉含量不同的人工饲料饲养５龄雌蚕。结果表明随着饲料蛋白质含量从９．１２％增至３７．１８％，每头蚕的氨基酸排出量从５４．９２增至２５９．８２ｍｇ。但蚕体对Ｌｅｕ、Ｐｈｅ、Ｖａｌ、Ｔｈｒ、Ｈｉｓ、Ｇｌｕ等氨基酸的吸收率则随饲料中蛋白质含量的增加而降低。而蚕体对Ａｒｇ、Ｌｙｓ、Ａｌａ、Ｉｌｅ、Ｇｌｙ、Ｐｒｏ、Ａｓｐ的吸收率及对所测１６种氨基酸的平均吸收率，则均以饲料蛋白质含量为１６．１４％时为最高。蚕体对氨基酸的吸收与氨基酸性质有关，吸收率依次为：碱性＞中性＞杂环＞酸性。     

Comparative analysis of RBC membrane fatty acids, proteins and glycophorin in patients with heterozygous beta thalassemia and iron deficiency anemia

Membrane lipid and protein composition was compared in erythrocytes from iron deficiency anemia (IDA) and heterozygous beta thalassemia patients. The study was planned to correlate the influence of iron deficiency with the intrinsic defect of the heterozygous condition on the membrane structural integrity as well as to investigate whether there are differences in membrane changes between the two conditions. Results indicate high levels of saturated fatty acids and low unsaturated fatty acids in both disorders although arachidonic acid and the unsaturation index were lower in heterozygous thalassemia than IDA. Nevertheless, neither of the conditions provoked any alterations in membrane protein or glycophorin suggesting alterations in the lipid moiety only. Present findings indicate that irrespective to the etiology, both, iron deficiency and the heterozygous condition show a common pattern of lipid derangement, which may in turn result in increased membrane rigidity and decreased cellular deformability.     

DNA生物传感器研究综述

DNA生物传感器在检测特定序列基因时因具有灵敏度高、响应快、操作简便、价格低廉、所需仪器简单等优点已经被广泛应用在疾病诊断、食品检验、环境监测以及军事反恐等领域.为此,通过大量的文献资料对DNA生物传感器的研究内容和设计原理、DNA生物传感器的分类、DNA生物传感器的应用等进行阐述,并且对DNA生物传感器的发展趋势进行探讨.     

大竹蛏软体部分的氨基酸组成分析

测定大竹蛏软体部分的氨基酸组成。结果表明,大竹蛏软体部分干物质中水解氨基酸总量为81.213%,其中必需氨基酸为27.221%,占氨基酸总量的33.518%;游离氨基酸中6种呈味氨基酸含量丰富,占游离氨基酸总量的81.09%;大竹蛏软体部分限制氨基酸为缬氨酸,必需氨基酸指数为49.88。认为大竹蛏是一种营养价值和养殖价值都较高的品种。     

硬软酸碱原理与Baeyer-Villiger重排反应

本文应用硬软酸碱原理对Baeyer-Villiger重排反应选择性规律进行理论解释,并说明了异丙苯氧化酸性水解重排反应也遵循硬软酸碱原理。     

偶氮苯修饰的DNA对引物延伸的光调控

研究偶氮苯单元修饰在核酸上控制引物延伸的行为。系统地筛选5、6、7和8个碱基的保护链通过4,4'-二羟甲基偶氮苯连接的25 mer DNA模板,并研究其在紫外光照前后调控的引物延伸效率。结果表明,具有7个保护碱基的C3对Pri.15和6个碱基短链的C2对Pri.17都具有较好的光调控延伸效果。其中C3,在Vent酶作用下紫外光照后引物延伸效率增加1倍以上。而C2,尽管紫外光照前增加了引物延伸的背景,在Vent酶催化下紫外光照射后的延伸产率达到91.4%,比紫外光照前增加84%。本工作为分子水平上研究基因功能、基因表达网络以及疾病的发生和发展提供了一种新的策略和研究手段。