抚顺城区大气悬浮颗粒物污染与呼吸系统疾病死亡率相关性的定量分析

为了定量分析大气总悬浮颗粒物(TSP)对居民呼吸系统疾病死亡率的影响,采用单因素泊松(Poisson)回归分析法,研究了辽宁省抚顺市城区TSP浓度变化与市区1999～2003年呼吸系统疾病死亡率的相关关系.结果发现,在消除了时间、气象等因素影响后,滞后4日TSP浓度每增加50μg·m-3,呼吸系统疾病总人群组死亡率相对危险度(OR)增加1.02195(95%CI=1.00195～1.04245),即滞后4日TSP浓度变化造成总人群组呼吸系统疾病死亡率明显增加的超额死亡率为2.195%.抚顺城区大气TSP污染可能是市区居民呼吸系统疾病死亡率增加的原因之一.     

Biodegradation of synthetic surfactants by river microorganisms

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Genetic influence on caste determination underlying the asexual queen succession system in a termite

The question of how reproductives and sterile workers differentiate within eusocial groups has long been a core issue in the study of social insects. Recent studies have shown that not only environmental factors but also genetic factors affect caste differentiation. In the termite Reticulitermes speratus, queens produce their replacements (neotenics) asexually but use normal sexual reproduction to produce other colony members. Here, we demonstrate a genetic influence on caste determination underlying the asexual queen succession system in this termite species. Thelytoky in termites is accomplished by automixis with terminal fusion, yielding almost completely homozygous offspring; thus, parthenogenetically and sexually produced offspring profoundly differ in heterozygosity. An analysis of the relationship between the reproductive dominance of female neotenics obtained from experimentally orphaned colonies and their genotypes at five microsatellite loci showed that homozygosity at two loci influenced the developmental priority and/or reproductive quality of neotenics. These results suggest the existence of a multi-locus system affecting the queen fecundity and explain why parthenogens have genetic priority to become neotenics in this termite species.     

Ultraweak photon emission from herbivory-injured maize plants

Following perception of herbivory or infection, plants exhibit a wide range of inducible responses. In this study, we found ultraweak photon emissions from maize leaves damaged by Helicoverpa armigera (Noctuidae). Interestingly, mechanically damaged maize leaves treated with caterpillar regurgitants emitted the same intensity and pattern of photon emissions as those from maize leaves damaged by caterpillars. Furthermore, two-dimensional imaging of the leaf section treated with the oral secretions clearly shows that photon emissions were observed specifically at the lip of the wound exposed to the secretions. These results suggest that the direct interaction between maize leaf cells and chemicals contained in caterpillar regurgitants triggers these photon emissions.     

Removal of pentachlorophenol from contaminated soil by catalytic oxidation with iron(III)-porphyrin complexes and potassium monopersulfate

Pentachlorophenol (PCP) in contaminated soil was removed by treatment with aqueous solutions of iron(III)-porphyrin complexes as catalysts and potassium monopersulfate (KHSO₅) as the oxygen donor. The contaminated soils were artificially prepared by spiking PCP to the kaolin and ando soils. Three types of iron(III)-porphyrin complexes, tetra(?p-sulfophenyl) porphineiron(III) (Fe(III)-TPPS), tetra(N-methyl-4-pyridil)porphineiron(III) (Fe(III)-TMPyP) and heme, were examined, and Fe(III)-TPPS was found to be the most effective for removing PCP. Although the sequential addition of KHSO₅ was examined, in an attempt to improve the efficiency of PCP removal, it was not effective. In a preliminary test of various aqueous solutions, the addition of humic acid (HA), with a lower degree of humification, led to a significant enhancement in PCP removal. When HA was added to the soil system, the percentages of PCP removal were increased by up to 10% compared to the absence of HA. Therefore, the addition of HA to the catalytic system was useful in enhancing PCP removal from contaminated soil.     

Accelerating effect of sodium chloride on mexiletine adsorption onto activated charcoal

The effective use of activated charcoal as an oral adsorbent for primary treatment of acute poisoning was investigated in vitro by evaluating the characteristics of mexiletine, an anti-arrhythmic drug, adsorbed onto activated charcoal in the presence of sodium chloride solutions at various concentrations. The equilibrium amount of mexiletine adsorbed onto activated charcoal was increased by the addition of sodium chloride. In particular, there was a marked increase in the amount adsorbed from a solution of lower mexiletine concentration. The removal rate is another important factor in the evaluation of activated charcoal, and a rapid decrease of mexiletine concentration by the addition of sodium chloride was recognized. The acceleration of mexiletine adsorption onto activated charcoal by the addition of sodium chloride was due to the occurrence of salting-out. It could be concluded that the administration of activated charcoal suspended in saline solution was more effective in the primary treatment of acute poisoning by mexiletine overdose.     

Pharmacogenomics of the human ABC transporter ABCG2: from functional evaluation to drug molecular design

In the post-genome-sequencing era, emerging genomic technologies are shifting the paradigm for drug discovery and development. Nevertheless, drug discovery and development still remain high-risk and high-stakes ventures with long and costly timelines. Indeed, the attrition of drug candidates in preclinical and development stages is a major problem in drug design. For at least 30% of the candidates, this attrition is due to poor pharmacokinetics and toxicity. Thus, pharmaceutical companies have begun to seriously re-evaluate their current strategies of drug discovery and development. In that light, we propose that a transport mechanism-based design might help to create new, pharmacokinetically advantageous drugs, and as such should be considered an important component of drug design strategy. Performing enzyme- and/or cell-based drug transporter, interaction tests may greatly facilitate drug development and allow the prediction of drug–drug interactions. We recently developed methods for high-speed functional screening and quantitative structure–activity relationship analysis to study the substrate specificity of ABC transporters and to evaluate the effect of genetic polymorphisms on their function. These methods would provide a practical tool to screen synthetic and natural compounds, and these data can be applied to the molecular design of new drugs. In this review article, we present an overview on the genetic polymorphisms of human ABC transporter ABCG2 and new camptothecin analogues that can circumvent AGCG2-associated multidrug resistance of cancer.     

Industrial waste management simulation game and its educational effect

The purposes of this study were to develop the Industrial Waste Game and to examine the validity of this game as a tool for environmental education. The aim of this game is to enable players to understand the social dilemma between individual interest of hazardous dumping and the social cost of purifying pollution, and to find a solution to the social dilemma by providing the monitoring and sanction system for illegal dumping or other efficient systems. The game was played by 213 undergraduate students who were divided into 40 groups of 5 to 6 people. One of 4 combinations of monitoring and penalty conditions was assigned to each group. The players were asked to answer questionnaires concerning their interests and understanding of the industrial waste issue before and after the game to evaluate educational effects. The results indicated that the players increased their awareness of industrial waste problems and came to understand that these problems were caused not by psychological factors such as immorality of the illegal dumper but mainly by social structural factors like the social dilemma. Through playing the game and participating in post-game discussion, players were able to obtain interesting experience and gain motivation to learn more.