植原体DNA提取方法的改良

在总结多种植原体DNA提取方法的基础上 ,发展了一种提取植原体DNA新方法。用此方法提取的DNA经琼脂糖凝胶电泳检测到大于 15kb的DNA主带 ,基本无DNA碎带 ,不用RNase处理 ,也无RNA干扰 ,OD2 60 / 2 80 值显示产物纯度较高 ,无需任何处理 ,即可以作为模板扩增     

Quality-of-life indicators at different scales: Theoretical background

The article is presenting the general analysis of the systems approach and model approaches for the development of QoL indicators and indices. In our study we propose the method of response function as a method of the construction of purposeful, credible integrated models from data and prior knowledge or information. The method of response function implies credible models in the sense that they are identifiable, and, hopefully, explains system output behaviour satisfactorily.Using response function method for the development of QoL models, we are able to obtain QoL indices as the direct output of the models.     

An Algorithm for Cladistics—Method of Minimal Parallel Evolution

The paper presented here is Concerned with the numerical cladisties. In consideration of the fact that the parallel evolution has close relation to the length of evolution graph, a new method of reconstructing evolutionary tree has been developed for the application and practice of cladistics. The procedure of the algorithm of the new method presented in Table I is similar to the method described in paper "An algorithm for cladistics method of maximal same step length". An essential step of the algorithm is how to decide the coefficient between two cladistic units (CTUs). A coefficient called parallel evolutionary coefficient between CTUp and CTUq is defined as follows: where the j is code of CTU and the i is code of character; E(p, q, i, j) is a function given by following expression: min (X_ij, Xpj)+(X_ij, Xqj)-2min(Xpj, Xqj) as Xij>min (Xpj, Xqj) E(p,q, i,j ) = 0 otherwise. where the X_ij is the ith row (CTU) jth colunm (Character) element of the data matrix. Because the method of minimal parallel evolution is closely related to the length of evolutionary graph, it is superior to the method of maximal same step length. A simple datum as an example for comparison shows that the method of minimal parallel evolution can arrive at a better result. But in some cases, we may combine one method with another and thus the coefficient should take following form: S(S_ij)=M·S (C) _ij-N·S(P) _ij in which S (C) _ij and S (P) _ij are the same step coefficients and the parallel evolution coefficient respectively, and the M and N are positive integers as a weightnumber being given in advance.     

测定胸腺肽含量几种定量方法的比较

本文用凯氏定氮法、双缩脲法及福林－酚法测定了胸腺肽含量,并加以比较,说明三种方法对其含量测定没有显著差异．在实践中可以根据不同条件选择适当的方法进行实验．     

SCOP数据库蛋白质折叠类型的自动分类分析

蛋白质折叠规律研究是生命科学领域重要的前沿课题之一,蛋白质折叠类型分类是折叠规律研究的基础。本研究以SCOP数据库的蛋白质折叠类型分类为基础、以Astral SCOPe 2.05数据库中相似性小于40%的α、β、α+β及α/β类所属的折叠类型为研究对象,完成了989种蛋白质折叠类型的模板构建并形成模板数据库;基于折叠类型设计模板建立了蛋白质折叠类型分类方法,实现了SCOP数据库蛋白质折叠类型的自动化分类。家族模板自洽性检验与独立性检验所得的敏感性、特异性以及MCC的平均值分别为:95.00%、99.99%、0.94与90.00%、99.97%、0.92,折叠类型模板自洽性检验与独立性检验所得的敏感性、特异性以及MCC的平均值分别为:93.71%、99.97%、0.91与86.00%、99.93%、0.87。结果表明:模板设计合理,可有效用于对已知结构的蛋白质进行分类。     

乳酸菌天然质粒提取方法的优化

将前人报道的乳酸菌质粒提取方法与大肠杆菌质粒提取方法相结合,对常用试剂盒质粒提取方法进行改进,建立了一种快速、安全、高效的乳酸菌质粒提取方法。提取过程中,溶菌酶最佳浓度为20mg/ml,最佳处理时间为30min,同时避免了毒性物质溴化乙锭的使用。多次实验结果表明,采用改进后的方法可明显提高乳酸菌天然质粒的提取效果。且重复性好,为下一步乳酸菌的分子改良奠定了基础。     

幽门螺杆菌分离培养的研究

采用细菌培养法及快速尿素酶法分别检测了１６９例消化道疾病患者幽门螺杆菌（Ｈｅｌｉ－ｃｏｂａｃｔｅｒｐｙｌｏｒｉ,ＨＰ）感染情况。标本经２０％葡萄糖运送培养基运送后,分别涂布于选择性培养基和本室改良的选择性培养基,３７℃微氧环境（５％Ｏ２,１０％ＣＯ２,８５％Ｎ２）培养８天。标本同时采用快速尿毒酶法进行检测。结果表明,细菌培养法与尿素酶法检测阳性率接近,分别为４６％和５５％;细菌培养第６天与第８天其阳性检出率相同;选择性培养基与本室改良选择性培养基对幽门螺杆菌的检出率差别明显,分别为３４％（１７／４９）和５１％（６１／１２０）,同时其杂菌生长率分别为５４％（２９／４９）和２５％（３０／１２０）。     

细胞色素P450的多样性与介导抗性的研究

细胞色素单加氧酶是一类广泛分布在生物体内的重要酶系,在生物体内广泛分布,CYP450参与多种外源性化合物的代谢,内源性物质的合成,在生物体起到十分重要的作用,对P450的研究已从最开始的功能与定位深入到了它的分子机制和多样性等的研究,就P450的多样性、介导抗性的机制和分离方法作一综述。     

A Note on Testing Segregation between Two Groups of Animals Using Entropy

A kind of sample entropy is used as a measure of segregation between two groups of animals. This index is used to perform a test of segregation under the supposition of samples coming from multinomial independent distributions. For a large sample test the asymptotic distribution is found. This test is asymptotically equivalent to the classical χ² for contingency tables. The exact test is developed in a less general situation.     

Development and validation of a gas chromatographic method for the quantification of D-pinitol in decoctions of Desmodium adscendens

A decoction of the leaves and stems of Desmodium adscendens (Fabaceae), a herb occurring in Africa and South America, is used in traditional medicine. Previous phytochemical research revealed that flavonoids, soyasaponins, β-phenylethylamines, and an indol-3-alkylamine were present. Our investigations have led to the identification of D-pinitol, a carbohydrate with antihyperglycemic, hepatoprotective and anti-inflammatory effects, as a potentially active compound. In order to prepare a quantified extract to be used in in vivo experiments, an analytical method was developed and validated.A gas chromatographic method was developed. Two different derivatization methods, i.e. acetylation and trimethylsilylation, were evaluated. Trimethylsilylation yielded repeatable results and was selected. Five different sugar alcohols were evaluated in order to find a suitable internal standard. Xylitol was chosen since it did not co-elute and its structure closely resembled D-pinitol. Sonication and reflux extraction were investigated in order to obtain a quantitative extraction. This was achieved through reflux extraction during 0.5 h.The method was validated according to the ICH guidelines. The calibration model appeared to be linear, ranging from 5.13 μL/mL to 25.65 μL/mL. The method was precise with an inter-day precision lower than 1.3%. The accuracy ranged from 103.38% to 105.84%. The validated method was used for quantification of D-pinitol in lyophilized decoctions from D. adscendens administered in in vivo experiments. Typically, a D-pinitol level about 5% was measured. Additionally, different food supplements available on the market were screened. The amount D-pinitol found in these supplements ranged from 1.8 mg/capsule to 30 mg/capsule and was 2.0 mg/mL solution.     

酸奶中乳酸菌镜检涂片的特殊染色法

报道了酸奶中乳酸菌涂片的特殊染色法-甲苯胺蓝染色法。涂片固定后,用0．2％甲苯胺蓝染色液染色2min,然后,用1％乙酸溶液脱色数秒,即可使涂片中的菌体着奥蓝色,而背景呈现白色或无色,菌体形状十分清晰。即使涂片很厚且不均,也可清晰看到菌体。便于菌体细胞的计数,形态观察及摄影．     

A model of the plant-to-plant movement of aphids II. Estimation of parameters and the application

1. It was shown in the previous report that the statistical model of the plant-to-plant movement of aphids could be fitted well to the actual population of barley aphids (Shiyomi , 1967). To examine validity of the model, results of the further experiments were analysed and the methods of estimation of parameters were given in this paper.
2. Comparing the estimates of the parameters obtained by the moment method with those obtained by the maximum likelihood method, the estimates from the latter method were somewhat precise.
3. The theoretical frequency distributions calculated from the model were fitted very well to the observed ones.
4. The model was reexamined with reference to the results obtained byItô (1954, 1960). When the distance between plants was less than 4.5 cm, the farther was the distance between plants, the smaller was the rate of the plant-to-plant movement of aphids. When the distance was greater than 4.5 cm, however, the rate of the plant-to-plant movement was independent of the distance. This result is similar to that ofItô .

     

一种根癌农杆菌介导的简单、快捷转化雪柑的新方法

以雪柑种子为外植体,以pC1301-PMI-LFY重组载体为转化载体,将蘸有农杆菌侵染液的接种针在种子胚的顶端分生组织部位刺2-3次,深度1 mm左右,当实生苗成活后移栽.通过PCR检测和PCR-Southern杂交检测得到了1株转基因植株,转化率为4.35％.针刺法简便快速,在雪柑上能够成功应用,为木本植物的遗传转化提供了新的思路.     

Estimation of Distances and Variances in Bookstein's Landmark Model

Planar random figures can be described by series of landmarks. Bookstein's model assumes that the landmarks result from independent individual fluctuations around fixed fictive landmark centres. The aim of this paper is to estimate the distances between the centers and the variances of fluctuations around them. Furthermore, two new shape variable estimators are suggested and compared with an estimator of Bookstein.     

Logistic曲线参数的一个最佳估计方法

本文提出用O．628优选法和SAS/STAT软件NLIN模块中的DUD法,对Logistic曲线中的参数k,a和b可得到最佳估计。     

Nitrification and ammonia volatilisation losses from urea and dicyandiamide-treated urea in a sandy loam soil

Summary Nitrification and ammonia volatilisation losses from urea and dicyandiamide (DCD)-treated urea were studied in a sandy loam soil. Laboratory experiments indicated that 20 ppm (of soil) DCD effectively inhibited nitrification of urea over sixty days. If the urea was treated with DCD (20 ppm), ammonia emission from the soil was extended over 105 days; with urea alone, it was negligible after 15 days. A field study indicated that DCD treatment increased volatilisation losses of ammonia tremondously if urea was applied to the soil surface; these losses were minimised if the urea was placed at 5 cm depth. It would seem that nitrification inhibitors must be combined with a placement technique.     

一类捕食—食饵系统的定性分析

本文分析了一类具有Holling Ⅰ型功能性反应的捕食者种群与食饵种群相互作用的数学模型得出了如下结论:当e≥1,cd+br-ec~2x_0<0时,且b充分小则至少存在一个极限环;如果更要求d+r-ecx_0<0,b充分小时至少存在两个极限环。     

小鼠胃 Cajal 间质细胞分离与培养实验方法探讨

目的:尝试优化体外培养Balb/c小鼠胃Cajal间质细胞(interstitial cells of Cajal,ICC)的实验方法,为深入探索该细胞的生理病理作用机制提供基础。方法:无菌条件下取出小鼠胃组织,使用酶解法消化分离细胞,将细胞悬液接种于含有SCF(干细胞因子)的M199培养基中培养,并进行传代。倒置显微镜下观察不同时间段细胞生长状态,采用ICC特异性标志物c-Kit(酪氨酸激酶受体)进行免疫荧光鉴定。结果:细胞培养24 h后基本已贴壁,呈梭形或三角形,有短突起;72 h后细胞胞体变大,突起伸长;5 d后,细胞之间通过突起彼此相互连接,开始形成网状结构;传代后细胞依然保持其固有特征。免疫荧光鉴定可见细胞c-Kit抗体荧光染色阳性。结论:使用酶解法成功分离细胞,细胞数量较多但不增殖,传代后可见细胞纯度较好,稳定培养3周以上后细胞形态逐渐发生变化并开始凋亡。     

两种给药途径对联合抗生素建立伪无菌大鼠模型比较

利用联合抗生素通过饮水和灌胃2种给药途径干预大鼠,评估是否可建立伪无菌大鼠模型。

将15只SD大鼠随机分为正常组（Nor组）,饮水组（Dri组）和灌胃组（Ig组）,每组5只。饮水组：用超纯水配制成浓度为0.5 g/L万古霉素、1.0 g/L氨苄西林、1.0 g/L新霉素和1.0 g/L甲硝唑的混悬液,自由饮水。灌胃组：用生理盐水配制成浓度为200 mg/mL万古霉素,400 mg/mL氨苄西林,400 mg/mL新霉素和400 mg/mL甲硝唑的混悬液,0.5 mL/kg体积灌胃。建模14 d。收集空肠、盲肠和结肠的肠道内容物分别进行菌群培养,并对混合的肠道内容物样本进行测序。

与正常组相比,在有氧和厌氧培养条件下,饮水组和灌胃组肠道内容物在培养基上的菌落数量显著减少。饮水组和灌胃组肠道菌群丰富度和多样性均明显降低,肠道菌群的物种数量显著减少。饮水组大鼠肠道菌群主要以埃希-志贺菌属为主,灌胃组以克雷伯菌属为主。

通过饮水和灌胃给予大鼠联合抗生素,均清除了其大部分的肠道菌群,可以达到建立伪无菌大鼠模型的要求。