Regulation of the binding of 7,12-dimethylbenz[a]-anthracene to DNA of cultured murine epidermal cells at metabolic level: competition of the binding by polycyclic aromatic hydrocarbons and by other precarcinogens.

The binding of labeled carcinogen [3H]DMBA to murine epidermal cells (MEC) DNA in culture has been studied. The influence of unlabeled noncarcinogenic and carcinogenic polycyclic aromatic hydrocarbons (PAH), several PAH metablites, and various directly and indirectly acting non-PAH carcinogens on the binding of [3H]DMBA to MEC DNA has been examined. All the carcinogenic PAH and some of non-carcinogenic PAH effectively inhibit the binding of [3H]DMBA to MEC DNA. The non-PAH chemical carcinogens requiring metabolic activation also reduce the binding of labeled DMBA to MEC DNA; however, a higher concentration of these compounds is required for 50% inhibition of binding than the concentrations of PAH for the same degree of inhibition of binding of [3H]DMBA to MEC DNA. The directly acting carcinogens do not significantly inhibit the binding of [3H]DMBA to DNA. The relationship between structures of PAH and their ability to inhibit the binding of [3H]DMBA to MEC DNA is also discussed. Thus, it appears that the binding of DMBA to cellular DNA is primarily controlled at a level of metabolism and to some extent at the level of binding of reactive metabolites to DNA.     

Zero‐modified Poisson model: Bayesian approach,influence diagnostics,and an application to a Brazilian leptospirosis notification data

In this paper, a Bayesian method for inference is developed for the zero‐modified Poisson (ZMP) regression model. This model is very flexible for analyzing count data without requiring any information about inflation or deflation of zeros in the sample. A general class of prior densities based on an information matrix is considered for the model parameters. A sensitivity study to detect influential cases that can change the results is performed based on the Kullback–Leibler divergence. Simulation studies are presented in order to illustrate the performance of the developed methodology. Two real datasets on leptospirosis notification in Bahia State (Brazil) are analyzed using the proposed methodology for the ZMP model.     

Luminometric measurement of population activity of genetically modified Pseudomonas fluorescens in the soil

Genetically modified cells of Pseudomonas fluorescens, chromosomally marked with genes for bioluminescence, were inoculated into sterile soil microcosms. During incubation for 90 days, viable cell concentration did not change significantly but light output, measured by luminometry, decreased, indicating reduced metabolic activity due to lack of substrates. Amendment with nutrients resulted in parallel increases in both luminescence and dehydrogenase activity. Luminometry therefore enables rapid monitoring of the activity of populations of luminescence-marked microbial inocula in the soil, with greater sensitivity and selectivity than traditional techniques.     

Determination of absolute configuration of photo-degraded catechinopyranocyanidin A by modified Mosher's method

Catechinopyranocyanidins A and B (cpcA and cpcB) are two purple pigments present in the seed-coat of red adzuki bean, Vigna angularis, of which cpcA is the major pigment, containing two chiral carbons in the catechin part. Their absolute configurations were determined by comparison of their experimental and quantum chemical calculated electronic circular dichroisms (ECDs). These purple pigments are labile on light irradiation and easily decompose to photo-degraded catechinopyranocyanidins A and B (pdcpcA and pdcpcB), while retaining the stereostructure of the catechin residue. We applied modified Mosher's method for determining the chirality of the secondary alcohol in pdcpcA. Hexamethylation of pdcpcA by diazomethane followed by esterification using (S)- and (R)-MTPACl gave (R)- and (S)-MTPA esters, respectively. By analysis of the NMR spectra of (R)- and (S)-MTPA esters of tetramethylated (+)-catechin, the chirality of pdcpcA was determined to be 2R, 3S, same as the absolute configuration of cpcA.     

Chiral Imidazolidin-4-one with catalytic amount of Dicationic ionic liquid act as a recoverable and reusable Organocatalyst for asymmetric Diels-Alder reaction

Imidazolidin-4-one is used as a recoverable organocatalyst for the asymmetric Diels-Alder reaction in the presence of catalytic amount of dicationic ionic liquid and trifluoroacetic acid as a co-catalyst. The Diels-Alder reaction between model substrate cyclopentadiene and crotonaldehyde gave the product in 95% conversion and 87% ee of the endo-product. The catalyst was shown better reusability when the 20 mol% of dicationic ionic liquid was used and catalyst was reused upto 5 cycles, conversion remains upto 3 recycles but ee of endo- 9 was slightly droped.     

玉米转基因技术专利权人合作态势分析

转基因玉米是最重要的转基因主粮作物之一,其转基因技术具有一定的代表性。为了更好地了解和掌握玉米转基因技术领域研发主体合作情况,文章构建了基于专利权人合作网络的目标技术领域专利权人合作态势分析框架,并基于社会网络分析方法与技术,以世界范围内的转基因玉米领域的重要专利权人为分析对象,构建合作网络、分析整体合作特征、挖掘合作子网、探测领域内重要专利权人,从而从宏观、中观和微观三个层面客观展现玉米转基因技术领域专利权人合作态势,为科技战略规划提供一定的决策支撑。     

耐除草剂玉米G1105E-823C定性检测方法

转基因耐除草剂玉米G1105E-823C是经过改造的转mG2-aroA基因耐草甘膦玉米新品系,具有更高的草甘膦耐受性,目前已完成生产性试验,具有重要的产业化应用前景。但目前尚无针对G1105E-823C的转化体特异性检测方法的相关报道,这十分不利于对该品系的检测及监管。基于此,以G1105E-823C转化体特异性序列为靶标,建立了转基因耐除草剂玉米G1105E-823C的普通PCR和实时荧光PCR定性检测方法。结果表明,2种方法均能检测出转基因耐除草剂玉米G1105E-823C转化体成分,且具有较高的特异性。普通PCR检测方法检出限达0.1%,实时荧光PCR检测方法检出限达0.05%。研究建立的2种定性检测方法为转基因耐除草剂玉米G1105E-823C的精准检测提供了新的技术手段,可为农业转基因监管提供技术支撑。     

转基因抗虫玉米发展现状与展望*

转基因抗虫玉米的商业化种植,成为大幅提高农业生产力的主要推进器之一。近年来,转基因抗虫玉米产业化规模不断扩大,有效控制了靶标害虫的发生危害,降低了化学杀虫剂的施用,为粮食安全与农民增收提供了重要保障。介绍了全球转基因抗虫玉米的发展现状,分析了与转基因抗虫玉米种植相关的生态问题,并提出了推进转基因抗虫玉米在我国产业化的相关建议。