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121.
Alkyl esters of p-hydroxybenzoic acids (parabens), an endocrine disrupter, are used as preservatives in cosmetics and foods. In this study, to understand the relationship between parabens and differentiation in infants, the effects of parabens on apoptosis induced by serum deprivation in PC12 cells were investigated. In addition, apoptosis-related factors were assayed. As results, a tendency toward enhancement of apoptosis was observed in the cells cultured in the serum-free medium with methylparaben, and this tendency was suggested to be related to the contents of BAD, a pro-apoptotic protein. Butylparaben did not show any tendency to enhance apoptosis.  相似文献   
122.
In order to determine whether natural attenuation of chlorinated ethenes by microbial activity occurs in aquitards, sediments at a site contaminated with tetrachloroethene were vertically studied by drilling. The distribution of microbes (Dehalococcoides group and anaerobic hydrogen producers) and the ability of the sediments to sustain microbial dechlorination were determined in an aquitard as well as in an aquifer. Close-spaced sampling revealed the existence of large populations of Dehalococcoides and H(2)-producing bacteria, especially in the organic-rich clayey aquitard rather than in the aquifer. The vinyl chloride reductase gene was also detected in the clay layer. Furthermore, incubation experiments indicated that the clay sediment could sustain transformations of tetrachloroethene at least to vinyl chloride. In contrast, no significant transformation was observed in the aquifer sand. Our results indicate that dechlorination of tetrachloroethene by bacteria can take place in an organic-rich clayey aquitard, and that organic-rich clay may also be important in the natural attenuation in an adjacent aquifer, possibly supplying a carbon source or an electron donor.  相似文献   
123.
Humanity faces an increasing possibility that unusual and extreme natural disasters will increase, compounded with climate change, including global warming. These compound events are designated as compounded natural hazards in this study. A methodology must be developed for predicting what events and risks will confront future societies, to propose countermeasures and adaptation strategies against these events, and to evaluate the influences of compound disasters on infrastructure which is particularly situated near coasts and rivers. Based on the above-stated background and demands, this study was undertaken with the intention of upgrading the methodology for estimating effects on infrastructure of compound events such as increased typhoon and rainfall severity caused by global warming occurring concurrently with a great earthquake in Japan. Such a methodology is expected to contribute to progress in the fields of natural disaster mitigation and land preservation, particularly benefiting coastal and river areas in Japan. Additionally in this study, risk and economic loss analyses for the possible occurrence of compound disasters for coastal infrastructure and foundations are produced for establishing environmental strategies at the governmental level. The authors further propose adaptation strategies and techniques as countermeasures against these events.  相似文献   
124.
We characterized the ability of the cell free extract from polychlorinated dibenzo-p-dioxins degrading bacterium Geobacillus sp. UZO 3 to reduce even highly chlorinated dibenzo-p-dioxins such as octachlorodibenzo-p-dioxins in incineration fly ash. The degradation of 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD) as a model dioxin catalyzed by the cell free extract from this strain implicates that the ether bonds of 2,7-DCDD molecule undergo reductive cleavage, since 4′,5-dichloro-2-hydroxydiphenyl ether and 4-chlorophenol were detected as intermediate products of 2,7-DCDD degradation.  相似文献   
125.
In order to develop a sound material-cycle society, cost-effective municipal solid waste (MSW) management systems are required for the municipalities in the context of the integrated accounting system for MSW management. Firstly, this paper attempts to establish an integrated cost-benefit analysis (CBA) framework for evaluating the effectiveness of MSW management systems. In this paper, detailed cost/benefit items due to waste problems are particularly clarified. The stakeholders of MSW management systems, including the decision-makers of the municipalities and the citizens, are expected to reconsider the waste problems in depth and thus take wise actions with the aid of the proposed CBA framework. Secondly, focusing on the financial cost, this study develops a generalized methodology to evaluate the financial cost-effectiveness of MSW management systems, simultaneously considering the treatment technological levels and policy effects. The impacts of the influencing factors on the annual total and average financial MSW operation and maintenance (O&M) costs are analyzed in the Taiwanese case study with a demonstrative short-term future projection of the financial costs under scenario analysis. The established methodology would contribute to the evaluation of the current policy measures and to the modification of the policy design for the municipalities.  相似文献   
126.
The concentration levels and congener profiles of polychlorinated biphenyls (PCBs), pentachlorobenzene (PeCBz), and hexachlorobenzene (HxCBz) were assessed in commercially available organic pigments. Among the azo-type pigments tested, PCB-11, which is synthesized from 3,3′-dichlorobendizine, and PCB-52, which is synthesized from 2,2′,5,5′-tetrachlorobendizine, were the major congeners detected. It is speculated that these were byproducts of chlorobendizine, which has a very similar structure. The total PCB concentrations in this type of pigment ranged from 0.0070 to 740 mg/kg. Among the phthalocyanine-type pigments, highly chlorinated PCBs, mainly composed of PCB-209, PeCBz, and HxCBz were detected. Their concentration levels ranged from 0.011 to 2.5 mg/kg, 0.0035 to 8.4 mg/kg, and 0.027 to 75 mg/kg, respectively. It is suggested that PeCBz and HxCBz were formed as byproducts and converted into PCBs at the time of synthesizing the phthalocyanine green. For the polycyclic-type pigments that were assessed, a distinctive PCB congener profile was detected that suggested an impact of their raw materials and the organic solvent used in the pigment synthesis. PCB pollution from PCB-11, PCB-52, and PCB-209 pigments is of particular concern; therefore, the monthly variations in atmospheric concentrations of these pollutants were measured in an urban area (Sapporo city) and an industrial area (Muroran city). The study detected a certain level of PCB-11, which is not included in PCB technical mixtures, and revealed continuing PCB pollution originating from pigments in the ambient air.  相似文献   
127.
This paper reports the preparation of chitin/cellulose films compatibilized with polymeric ionic liquids. In-situ (co)polymerization of polymerizable ionic liquids, 1-(3-methacryloyloxypropyl)-3-vinylimidazolium bromide (1) and 1-methyl-3-vinylbenzylimidazolium chloride (3), was carried out in the presence of a radical initiator, AIBN, in the chitin/cellulose solution with ionic liquid solvents (1-butyl-3-methylimidazolium acetate and chloride, BMIMOAc and BMIMCl, respectively), followed by the appropriate procedure to give the desired films. The presence of the polymeric ionic liquid in the film was confirmed by the IR measurement. The powder X-ray diffraction analysis suggested that crystalline structures of the polysaccharides were largely disrupted in the film, as same as that of a chitin/cellulose film prepared by the AMIMOAc/BMIMCl system. These results were different from the XRD result of a chitin/cellulose film prepared by the 1-allyl-3-methylimidazolium bromide/BMIMCl system reported in our previous study, in which some crystalline structures were still remained in the film. Furthermore, the mechanical properties of the present films were evaluated by tensile testing, which were affected by the molar ratios of the polymeric ionic liquids to the polysaccharides and the compositional ratios of the two units 1 and 3.  相似文献   
128.
129.
2,2′,3,5′,6-Pentachlorobiphenyl (PCB 95) and 2,2′,3,4,4′,5′,6-heptachlorobiphenyl (PCB 183) possess axial chirality and form the aS and aR enantiomers. The enantiomers of these congeners have been reported to accumulate in the human body enantioselectively via unknown mechanisms. In this study, we determined the cytochrome P450 (CYP) monooxygenase responsible for the enantioselective oxidization of PCB 95 and PCB 183, using a recombinant human CYP monooxygenase. We evaluated 13 CYP monooxygenases, namely CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, CYP3A4, CYP3A5, CYP4F2, and aromatase (CYP19), and revealed that CYP2A6 preferably oxidizes aS-PCB 95 enantioselectively; however, it did not oxidize PCB 183. The enantiomer composition was elevated from 0.5 (racemate) to 0.54. In addition, following incubation with CYP2A6, the enantiomer fraction (EF) of PCB 95 demonstrated a time-dependent increase.  相似文献   
130.
Risk perception in Northeast Asia   总被引:1,自引:0,他引:1  
Multi-country surveys of the public's perception of risk using the same questionnaire were sequentially implemented from April to December 2006 in Japan, China, and South Korea. Statistical analyses, such as traditional mean tests, rank order tests, two-step cluster analysis, and principal component analysis were used to analyze the survey data. The results revealed that Chinese tend to be more tolerant of risk than Japanese and South Koreans. In all three countries, the threats of global warming, cancer, traffic accidents, and fire were perceived as higher-order risks, while infectious diseases and threats from high technology were perceived as lower-order risks. Looking across the entire multi-country sample, we found that Chinese participants perceived greater risk in typhoons, SARS, and drugs; Japanese saw greater risk from gas explosions and potential threats coming over the Internet; while people in all three countries identified earthquakes as a primary risk. These differences in risk perception reflect the natural and socioeconomic conditions in the three countries. Although the study did not emphasize differences in risk perception within countries based on demographic factors such as education, age, and gender, we found that differences based on education and age tended to be greater in China and South Korea than in Japan. We also found that men perceived greater risks than women in China and South Korea, while in Japan it was the opposite with women perceiving greater risks. A comparison of these results with previous studies reveals a bias in past studies toward student samples and indicates the need for more representative samples in multi-country surveys.  相似文献   
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