Detection of processed genetically modified food using CIM monolithic columns for DNA isolation

The availability of sufficient quantities of DNA of adequate quality is crucial in polymerase chain reaction (PCR)-based methods for genetically modified food detection. In this work, the suitability of anion-exchange CIM (Convective Interaction Media; BIA Separations, Ljubljana, Slovenia) monolithic columns for isolation of DNA from food was studied. Maize and its derivates corn meal and thermally pretreated corn meal were chosen as model food. Two commercially available CIM disk columns were tested: DEAE (diethylaminoethyl) and QA (quaternary amine). Preliminary separations were performed with standard solution of salmon DNA at different pH values and different NaCl concentrations in mobile phase. DEAE groups and pH 8 were chosen for further isolations of DNA from a complex matrix-food extract. The quality and quantity of isolated DNA were tested on agarose gel electrophoresis, with UV-scanning spectrophotometry, and by amplification with real-time PCR. DNA isolated in this way was of suitable quality for further PCR analyses. The described method is also applicable for DNA isolation from processed foods with decreased DNA content. Furthermore, it is more effective and less time-consuming in comparison with the existing proposed methods for isolation of DNA from plant-derived foods.     

亚运会兴奋剂检测

本文建立了检查IOC禁用的五大类100种药物的筛选和确证方法。对药物检查机构及资格认可,药物检验的一般步骤,第十一届亚运会兴奋剂的检测均作了简要的介绍。     

Some comments on the use of nitrogen selective detectors

Summary Several detectors which have a selective response toward nitrogen containing compounds are discussed. Data on sensitivities, detection limits and reproducibility of response are given. The application of chemiluminescence to provide a nitrogen selective GC detector is proposed.     

兴奋剂检测中的化学衍生化方法

本文评述了兴奋剂检测中的各种化学衍生化方法,对蛋白同化激素、麻醉镇痛剂、β-阻断剂和利尿剂分别进行了讨论。这四类药物结构各不相同,但绝大多数属于高沸点、难挥发的极性化合物,不适于直接进行GC或GC/MS分析。通过化学衍生化.不仅可增大试样的挥发性和稳定性,减小样品的极性,使原来难以进行GC分析的试样转变成适合于色谱分析的试样,而且通过衍生化还可达到改善分离效果、提高检测灵敏度的目的。     

Existence of finitely optimal solutions for infinite-horizon optimal control problems

In this paper, we investigate the existence of finitely optimal solutions for the Lagrange problem of optimal control defined on [0, ) under weaker convexity and seminormality hypotheses than those of previous authors. The notion of finite optimality has been introduced into the literature as the weakest of a hierarchy of types of optimality that have been defined to permit the study of Lagrange problems, arising in mathematical economics, whose cost functions either diverge or are not bounded below. Our method of proof requires us to analyze the continuous dependence of finite-interval Lagrange problems with respect to a prescribed terminal condition. Once this is done, we show that a finitely optimal solution can be obtained as the limit of a sequence of solutions to a sequence of corresponding finite-horizon optimal control problems. Our results utilize the convexity and seminormality hypotheses which are now classical in the existence theory of optimal control.This research forms part of the author's doctoral dissertation written at the University of Delaware, Newark, Delaware under the supervision of Professor Thomas S. Angell.     

Sufficient conditions for a strong relative minimum in an optimal control problem

In this paper, on the basis of Young's method (Ref. 1), sufficient conditions for a strong relative minimum in an optimal control problem are given. Young's method generalizes geodesic coverings and the simplest Hilbert integral from the standard variational calculus. This paper carries Young's method over to nonparametric problems.     

司帕沙星软膏的制备与质量控制

为研制司帕沙星软膏，建立其含量测定方法。用差示紫外分光光度法在306nm外测定司帕沙星的含量。平均回收率为99．98％，RSD为0．72％，线性范围15．62－40．14μg/ml。该法简便、准确、快捷。     

微机控制离子色谱仪自动操作与数据处理系统

用转换器和ＩＢＭＰＣ／ＸＴ微机与Ｄｉｏｎｅｘ２０２０ｉ型离子色谱仪连接组成自动控制与数据处理系统，转换器由８０３１及８２５５等芯片组成，其功能是采集数据和转送数据，软件由汇编及Ｃ语言编制。这套新系统增加了注入／记录同步，分级梯度淋洗，自动连续进样等功能以及很强的数据处理能力。     

Reactions of lithiated 2,5-dimethylazaferrocene with selected electrophiles

Lithiation of 2,5-dimethylazaferrocene 1 with sec-BuLi/TMEDA in THF at −78 °C proceeds (as shown by quenching with D₂O) to comparable extent on the methyl groups and the Cp ring. However, the outcome of the reaction of the lithiated 1 with an electrophile depends on the nature of this electrophile. In the reaction with 4-methoxybenzaldehyde only the product originated from the lateral lithiation is formed, whereas the reaction with 4-methoxyacetophenone and 4,4′-dimethoxybenzophenone afforded mixtures of the products resulting from lateral and ring-lithiation. Similar results were also obtained in the reaction of lithiated 1 with chlorodiphenylphosphine and diphenyl diselenide. On the other hand, the exclusive formation of the Cp-substituted product was observed in the reaction of lithiated 1 with N,N-dimethylformamide. The structures of selected products (oily compounds were transformed into the corresponding crystalline W(CO)₅-complexes) were confirmed by X-ray diffraction. The presented reactions open a novel entry to specifically substituted azaferrocenes (especially those containing heteroatom substituents) with potential applications as ligands for the homogenous catalysis.     

Insecticidal Activity and Free Radical Scavenging Properties of Isolated Phytoconstituents from the Saudi Plant Nuxia oppositifolia (Hochst.)

Chromatographic purification of the alcoholic extract from the aerial parts of the Saudi plant Nuxia oppositifolia (Hochst.), Benth., resulted in five isolated phenolic compounds. Two flavones, hispidulin (1) and jaceosidin (2), and the phenylethanoid glycosides, verbascoside (3), isoverbascoside (4), and conandroside (5), were identified and their chemical structures were determined by spectroscopic analyses. The insecticidal activity of compounds 1 and 2, in addition to 11 compounds isolated in a previous research (6–16), was evaluated against the Yellow Fever mosquito, Aedes aegypti. Four compounds displayed adulticidal activity with LD₅₀ values of 2–2.3 μg/mosquito. Free radical scavenging properties of the plant extracts and compounds (1–5) were evaluated by measuring the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate radical cation (ABTS^•+) scavenging activity. All compounds exhibited notable activity, compared with the positive control, l-Ascorbic acid. This study suggests that N. oppositifolia could be a promising source of secondary metabolites, some with lethal adulticidal effect against Ae. aegypti.