红外光谱法在基因探测中的应用研究

应用干涉型傅里叶变换红外分光光度计及聚乙烯膜作载体,得到了单链、双链DNA、生物素-dUTP及经过缺口翻译参入生物素的DNA探针的红外光谱,观察到Bio-dUTP分子内化学键振动产生的特征吸收谱带。利用差谱技术比较了DNA与生物素标记DNA的差异。Bio-dUTP的特征吸收探测灵敏度可达0.1ng。同时分析了硝酸纤维膜与genescreen的红外透过性质。     

蔗糖密度梯度离心——原子吸收法测定锌在血清蛋白中的分布

用蔗糖密度梯度离心及石墨炉原子吸收法分析测定微量元素锌在人血清蛋白中的分布量,此方法具有分离效果好,能保证蛋白的完整性,以及较好的精密度等优点。     

应用荧光、水试和紫外吸收法鉴别伪劣中药材

为了建立快速鉴别多种中药材真伪优劣的方法,利用荧光鉴别、水试和紫外吸收法对多种中药材进行鉴别、检查。实验结果表明,法半夏、金银花、木香、柴胡、巴戟天等可通过紫外激发荧光、水试或紫外吸收图谱来快速鉴别药材真伪。本研究结果表明,以上三种方法快速、简便,可应用于有荧光反应、水试反应和紫外吸收特性的中药材的快检筛查。     

电阻率成像法在树干水分吸收过程研究中的应用

将地球物理学中广泛运用的电阻率成像法成功地运用于树干内部截面电阻率分布特性的监测,利用电阻率平面分布图来分析树干内水分的空间分布和动态变化特征。结果表明：截面内树干水分的含量具有从核心部沿径向向外逐渐递增的趋势;位置较高的截面比较低的截面具有更多的水分含量,但充足的水分补给能打破这种水分分布的规律性,靠近补给源的截面含水率上升幅度最高;即使是在水分补给充足的情况下,树干内水分的吸收并不是面状饱和推进的过程,而是存在着优先纵向流动的生理机制;利用电阻率的变化,可以实现水分在截面上的优势流的定位。     

金标法与免疫发光法检测CEA在健康体检中的应用

目的：探讨金标法和免疫发光法检测CEA在健康体检中的应用价值。方法：对728例健康体检的个人同时应用金标法和免疫发光法测定CEA,对结果进行分析。结果：金标法测定的阳性率为0．69％,免疫发光法测定的阳性率为0．41％,两者具有高度一致性。结论：对健康体检人群应先用金标法进行定性,对阳性结果再用免疫发光法进行定量。     

金标法与免疫发光法检测CEA 在健康体检中的应用

目的:探讨金标法和免疫发光法检测CEA在健康体检中的应用价值。方法:对728例健康体检的个人同时应用金标法和免疫发光法测定CEA,对结果进行分析。结果:金标法测定的阳性率为0.69%,免疫发光法测定的阳性率为0.41%,两者具有高度一致性。结论:对健康体检人群应先用金标法进行定性,对阳性结果再用免疫发光法进行定量。     

中国番茄黄化曲叶病毒利用根吸收法诱导基因沉默(VIGS)的初步研究

以含硫黄素酶Su基因的中国番茄黄化曲叶病毒卫星DNA作为载体,通过冻融法将其转化到农杆菌中,利用根部吸收法进行农杆菌侵染,对农杆菌介导的病毒诱导基因沉默体系进行了优化,探讨对病毒诱导基因沉默效率的影响。结果显示以OD600值为1.5的含质粒pBinPLUS-2mβ-Su,pBinPLUS-1.7A的农杆菌菌液1∶1混合进行根部吸收法侵染22-25 d的番茄幼苗,目的基因Su沉默导致番茄幼苗出现光漂白现象,半定量RT-PCR检测目的基因Su mRNA被显著降解,该体系的建立有利于对植物基因进行高通量功能分析。     

生物电阻抗分析法和双能X射线吸收法测量老年人体脂肪率的对比研究

目的：探究生物电阻抗分析法（Bioelectrical impedance analysis,BIA）和双能X射线吸收法（Dual-energy x-ray absorptiometry,DXA）这2种方法测量老年人体脂肪率的应用价值,为老年人的健康筛查提供工具和方法。方法：在北京招募115例老年志愿者,其中男性46人、女性69人,分别采用DXA法和BIA法进行体成分测量,运用SPSS 16.0和MedCalc统计软件分析2种方法测量体脂肪率的相关性和一致性。结果 采用DXA法和BIA法2种方法对老年人群的体脂肪率进行测量,差异无统计学意义 （P＞0.05）;通过相关性分析发现,老年男性、老年女性及全体老年受试者的相关系数r值分别为0.917 9、0.905 8和0.936 5（P<0.01）,具有较高的相关性;通过Bland-Altman分析发现,2种方法测得的老年男性、老年女性及全体老年受试者的体脂肪率均具有较强的一致性。结论：BIA和DXA测量老年人体脂肪率的相关性和一致性较好。     

傅里叶变换中红外光谱结合偏最小二乘法快速测定蕨菜总多糖含量CSCD

本文建立了一种快速预测蕨菜总多糖含量的方法。采用蒽酮-硫酸比色法测定140份蕨菜总多糖含量作为参比值,采集140份蕨菜样品的傅里叶变换中红外光谱图,结合偏最小二乘法,建立蕨菜总多糖定量分析模型。通过比较多元散射校正法、标准正态变换法、一阶导数法、二阶导数法、多元散射校正+一阶导数法、标准正态变换+一阶导数法、多元散射校正+二阶导数法以及标准正态变换+二阶导数法共8种不同的光谱预处理方法,运用多糖类化合物的中红外光谱学特征吸收筛选建模波段,对蕨菜多糖含量预测模型进行优化。结果表明:采用标准正态变换法作为光谱数据预处理方法,以1750~1600、1500~1400、1350~1290、1160~1070、1060~970、930~800 cm^(-1)作为建模波段,获得校正集相关性系数R^(2)为0.9308,校正均方差(RMSEC)为0.374%,检验集相关性系数R^(2)为0.9145,预测均方差(RMSEP)为0.418%,20组样品进行完全外部验证误差为:-0.35%~0.31%,相对误差值为:-0.83%~5.24%,所构建定量模型可用于蕨菜总多糖含量预测。     

蛋白芯片法在抗核抗体检测中的临床应用

目的：应用蛋白芯片法与欧蒙斑点法检测血清抗核抗体,并对其结果进行比较分析。方法：收集95例血清样本,其中45例确诊为自身免疫性疾病,阴性50例,同时采用蛋白芯片法和欧盟斑点法检测其抗核抗体（SSA、SSB、Sm、RNP、Scl—70、Jo-1、CENPB）,并对结果进行对比分析。结果：45例确诊病例中,蛋白芯片法阳性44份,欧蒙斑点法阳性41份,敏感度分别为97．78％和91．11％,特异度分别为98．95％和95．79％;按卡方检验进行结果统计,x^2=1．75,P〉0．05,差异无统计学意义。结论：蛋白芯片可用于临床检测自身免疫性疾病、治疗监测、疗效评估和预后判断。     

The gravimetric method for the determination of residual moisture in freeze-dried biological products

The gravimetric test for the determination of residual moisture in freeze-dried biological products performed in a humidity- and temperature-controlled room with the use of scrupulous gravimetric analytical technique can be used to accurately determine residual moisture in freeze-dried biological products such as antihemophilic factor (human) or honey bee venom allergenic extract. This method determines the first water of hydration of sodium tartrate dihydrate (7.93%) to within 1.3% of the calculated value with a relative standard deviation of 0.3% for 10 replicates. For this gravimetric procedure, freeze-dried samples containing from 1.12 to 4.4% residual moisture had relative standard deviations ranging from 3.6 to 9.1%. Samples containing less than 1.0% residual moisture by the gravimetric method such as intravenous immune globulin and antihemophilic factor (human) had relative standard deviations ranging from 16.7 to 47.0%. Relative standard deviations for residual moisture tests performed on comparable samples by the Karl Fischer and thermogravimetric methods showed similar variability.     

影响生物制品冻干粉针剂水分的探讨

探讨生物制品冻干粉针剂样品放置一时间后残余水分增高的原因。进行了水分测定,真空度检测,二甲硅油和丁基橡胶药用瓶塞干燥失重的检测。冻干后每只丁基橡胶药用瓶塞平均含水分0.00224g。结果表明丁基橡胶药用瓶塞灭苗,干燥和冻干过程中去除水分不彻底是引起样品中水分升高的直接原因。     

Validation of method for total selenium determination in yeast by flame atomic absorption spectrometry

A procedure using open digestion followed by flame atomic absorption spectrometry is described for measuring the total selenium content of Se-enriched yeast. The limits of detection and quantitation were 2.5 mg/L and 5 mg/L Se, respectively. The signal response was linear over the range of 5–50 mg/L Se, and the average recovery from spiked samples was 98.9%. The validated method was used to measure the Se content of Se-enriched yeast reference material and produced a result of 2145±38 mg/kg (n=3), which is in good agreement with the certified level of 2125 ±65 mg/kg.     

影响RT—PCR产物克隆的因素及其方法的优化

在对１２个以ＲＴ－ＰＣＲ扩增后的ｃＤＮＡ片段进行克隆的工作中,讨论了影响克隆效率的几个因素,并对原有的部分克隆步骤作了优化,取得了对适当长度基因片段进行克隆的快速、简便的方法。     

Two-compartment method for determination of the oxygen transfer rate with electrochemical sensors based on sulfite oxidation

The dissolved oxygen concentration is a crucial parameter in aerobic bioprocesses due to the low solubility of oxygen in water. The present study describes a new method for determining the oxygen transfer rate (OTR) in shaken-culture systems based on the sodium sulfite method in combination with an electrochemical oxygen sensor. The method replaces the laborious titration of the remaining sulfite by an on-line detection of the end point of the reaction. This method is a two-step procedure that can be applied in arbitrary flasks that do not allow the insertion of electrodes. The method does not therefore depend on the type of vessel in which the OTR is detected. The concept is demonstrated by determination of the OTR for standard baffled 1-L shake flasks and for opaque Ultra Yield™ flasks. Under typical shaking conditions, k_La values in the standard baffled flasks reached values up to 220 h^-1, whereas the k_La values of the Ultra Yield flasks were significantly higher (up to 422 h^-1).     

Enumeration of micro-organisms in processed soy products with an automated most probable number method compared with standard plate method

Aim: The automated TEMPO system (bioMerieux) is based on the most probable number (MPN) method for the enumeration of micro‐organisms in foods. In this study, we evaluated the performance of the TEMPO system as a diagnostic tool in comparison with the standard method in processed soy products. Methods and Results: A verification study was conducted using artificially contaminated soy product samples such as soy protein isolate, water‐soluble soy polysaccharides, soy milk and processed soy food. Five types of micro‐organisms were analysed using the automated MPN method (total aerobic bacteria, total coliforms, Enterobacteriaceae, yeast and mould and Staphylococcus aureus) vs the standard plate method. The results from each of the methods were highly correlated (r > 0·95). Naturally contaminated processed soy products on the market were also studied. There were no discrepancies observed between the respective methods. Conclusions: TEMPO methods were equivalent to the corresponding standard plate methods with very good rates of agreement. Significance and Impact of the Study: The automated MPN method is more practical and reliable for in‐house microbiological testing in processed soy products.     

Influence of mineralisation methods on the determination of the mineral content of the brown seaweed Undaria pinnatifida by atomic absorption spectrophotometry

The influence of 8 mineralisation (dry and wet ashings) procedures on the determination of the mineral content of the brown seaweed Undaria pinnatifida by atomic absorption spectrophotometry was studied. Two procedures are proposed for routine analysis: dry ashing using sample calcination at 450 °C, followed by ash treatment with hydrochloric acid and silica elimination by hydrofluoric acid, and wet digestion using hot nitric acid.     

HPLC法测定低pH静脉注射用人血丙种球蛋白麦芽糖含量

本文采用HPLC法测定低pH静脉注射用血丙种球蛋白中麦芽糖含量,所用色谱柱为氨基柱。首先用磺基水杨酸沉淀蛋白并离心分离,上清液上样分析。通过外标法建立三级校正曲线来测定样品中麦芽糖含量,该法准确快速较化学方法好。     

Storage stability of freeze-dried Lactobacillus acidophilus (La-5) in relation to water activity and presence of oxygen and ascorbate

Storage stability of freeze-dried Lactobacillus acidophilus was found to depend on water activity (0.11-0.43), oxygen level (atmospheric oxygen level and <4% oxygen compared) and presence of sodium ascorbate (0% and 10% (w/w)). Increasing water activities decreased bacterial survival, and a reduced oxygen level (<4% oxygen) improved the storage stability, which strongly indicates a connection between oxidative reactions and bacterial instability. The detrimental effect of atmospheric oxygen was reduced by including ascorbate in the freeze drying medium. However, when ascorbate was present a pink/red colour was observed on the surface of the dried samples increasing with the water activity and oxygen level. Increased water activity lead to increased browning also for samples without ascorbate. Free radicals were detected in the dried bacteria by ESR spectroscopy (broad single-peak ESR spectra), where the shape and the g-value was found to depend on the presence of ascorbate and the extent of browning. For increasing water activities the content of radicals increased to a certain level, after which it levelled off and/or decreased. The highest concentrations of radicals were detected in the dried bacteria with highest survival for a given water activity, i.e. low oxygen level and presence of ascorbate, pointing towards a role of semi-stable ascorbyl radicals as a “dead end” for otherwise detrimental free radical reactions.