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41.
Little is known about the fate of antimicrobials during common agricultural waste handling procedures. To better define the potential scope of this problem, concentrations of antimicrobials throughout the waste treatment process were estimated based on known antimicrobial usage, and the resulting predictions of high antimicrobial concentrations indicated the need for further investigation. Samples from building pits, a solids settling basin, a holding pond, and soil amended with waste treatment byproducts were therefore analyzed for traditional chemical parameters and macrolide, lincosamide, and tetracycline antimicrobials. Substantial improvements in water quality were observed during the treatment process. While the macrolide tylosin was not detected, chlortetracycline, oxytetracycline, and lincomycin were found at high concentrations throughout the waste treatment process. Oxytetracycline and lincomycin were also detected in soil from a field amended with waste treatment byproducts.  相似文献   
42.
To establish a concise and rapid procedure to analyze hexabromocyclododecane (HBCD) diastereomers in flame-retarded textiles, three different methods of extraction—Soxhlet, ultrasonic, and soaking extractions with toluene and dichloromethane (DCM)—were compared. During Soxhlet extraction using toluene, the percent contribution of α-HBCD to total HBCDs increased slightly and that of γ-HBCD decreased, indicating that γ-HBCD was isomerized to some extent at the boiling point of toluene (110.6 °C). For ultrasonic extraction, the temperature of the water bath can easily increase over time during the procedure, which might lead to undesirable effects. Therefore, we considered soaking extraction with DCM to be the most facile procedure to analyze HBCD diastereomers in textiles. Using the method established in this study, commercially available textiles in Japan (n = 10) were analyzed to understand the actual composition of HBCD contents and its diastereomer profiles. With the exception of one textile sample, HBCDs were detected in all the samples analyzed, with concentrations ranging from 22 000 to 43 000 mg kg−1 (i.e. 2.2–4.3%). We found a higher proportion of the α-diastereomer in most textile products compared with that of commercial HBCD mixtures, indicating that γ-HBCD isomerized to α-diastereomer by heating processes to incorporate the commercial formulation into treated materials or that the α-diastereomer preferentially absorbed onto textile materials during the manufacturing of flame-retarded consumer products.  相似文献   
43.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) accumulates and remains stable in the fatty tissues and liver of rodents for a long time. Considering the pronounced difference between species, long-term, low dose hepatic effects of TCDD were investigated after subcutaneous administration of TCDD into rhesus monkeys during pregnancy. Macroscopic and histopathological examination of the liver carried out 4 y after TCDD administration demonstrated intrahepatic focal fatty changes, infarction, hemorrhage, microthrombi-formation, sinusoidal ectasia, small hepatocyte hyperplasia, and increased number of alpha-smooth muscle actin (alpha-SMA)-positive cells. An electron microscopic study disclosed sinusoidal endothelial cell degeneration and injury in the liver of TCDD-treated monkeys. Western blot analysis showed downregulation of aryl hydrocarbon receptor (AhR) protein expression and decreased level of vascular endothelial (VE) cadherin but increased expression levels of CYP1A1 and transforming growth factor beta (TGF-beta) protein in the liver tissues. These changes observed in TCDD-exposed monkeys indicated sinusoidal endothelial cell injury and impairment in intrasinusoidal microcirculation. Infarction, focal fatty change, and microthrombi-formation are considered to be closely associated with intrahepatic circulatory impairment. Increased number of alpha-SMA-positive cells and decreased level of VE cadherin expression in the liver tissues might also be associated with sinusoidal endothelial cell injury. In addition, downregulation of AhR expression and increased CYP1A1 protein levels in the liver were consistent with persistent effects of TCDD. Although it has been reported that TCDD induced endothelial cell injury, this is the first report to describe vascular disorders and protein expression in the liver after injection with TCDD in a primate model.  相似文献   
44.
BACKGROUND, AIM AND SCOPE: Discussions on management of whales and whaling are factually monopolized by the International Whaling Commission (IWC), resulting in a limitation of information flow to outside communities. With an aim to improve the situation, this article briefly reviews whaling and dolphin/porpoise fisheries in Japan, which is recognized to be the world largest cetacean exploitation. MAIN FEATURES: The Japanese government grants an annual take of 22,647 cetaceans of 15 species for scientific whaling and various kinds of active dolphin/porpoise fisheries by the nationals. Further, over 100 baleen whales and numerous small cetaceans are taken in passive net fisheries. They are used mostly for human consumption and some for aquarium display. RESULTS: Sustainability of the take is not evident and some populations have shown a historical decline. The Japanese program of scientific whaling has been reviewed by IWC and its Scientific Committee (SC), although they have arrived at no consensus. DISCUSSION: The current scientific whaling program invites arguments from the view points of science as well as concerning the ethics of scientists, economy, and interpretation of the International Convention for Regulation of Whaling (ICRW) of 1946. The scientific whaling and other Japanese cetacean fisheries are benefited from nationalistic public attitude, and ambiguity and weakness of the ICRW. CONCLUSIONS: Japanese cetacean harvest will continue supported by domestic demand for whale products as long as the proceeds can sustain the operation, even with criticisms from outside communities. RECOMMENDATIONS AND PERSPECTIVES: For safe management of small cetaceans exploited by Japan, studies are urgent on the population structure, abundance and validity of catch statistics. The results should be open to scientific communities.  相似文献   
45.
In what has become known as the Yusho incident, thousands of people in western Japan were poisoned by the accidental ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds. In this study, we investigated the accumulation patterns of 69 PCB congeners in the blood of Yusho patients in comparison with those of non-exposed controls. The blood samples were collected at medical check-ups in 2004 and 2005. To compare the patterns of PCB congeners, we calculated the concentration ratio of each congener relative to the 2,2′,4,4′,5,5′-hexaCB (CB153) concentration. The concentration ratios of tetra- and penta-chlorinated congeners in the blood of Yusho patients were significantly lower than those of controls. To examine the cytochrome P450 (CYP)-dependent metabolic potential of the 2,3′,4,4′5-pentaCB (CB118), CB153, and 2,3,3′,4,4′5-hexaCB (CB156) congeners, we conducted PCB-CYP (CYP1A1, CYP1A2, CYP2A6, and CYP2B6) docking simulation by in silico analysis. The docking models showed that human CYP1A1, CYP2A6, and CYP2B6 isozymes have the potential to metabolize CB118 and CB153. On the other hand, it was inferred that CB156 is difficult to be metabolized by these four CYP isozymes. These results indicate that CYP1 and CYP2 isozymes may be involved in the characteristic accumulation patterns of PCB congeners in the blood of Yusho patients.  相似文献   
46.
This study presents concentration of nine minerals (Na, K, Mg, Ca, Cl, Mn, Zn, Cd, Pb) in 31 drinking water samples collected in the Papua New Guinea lowland, where coastal villagers draw water from artificial wells blended with sea water, riverside villagers utilize brackish river water, and inland villagers fetch creek or swamp water whose chemical composition is close to rain water. During the dry season, the coastal well water contains 500 mgL−1 of sodium and 50–90 μgL−1 of lead. The inland creek or swamp water contains very small amount of minerals; on the average, for instance, 0.64 mgL−1 of magnesium, 0.84 mgL−1 of calcium, and 4.78 mgL−1 of water hardness (as CaCO3). From some epidemiological evidence in industrialized countries, these mineral concentrations are judged to be indicative of high risk of cardiovascular disorders.  相似文献   
47.
48.
The aim of this paper is to explore and present a proposal for redesigning elements of the workplace for agech workers. The method of research was to observe, record, and measure the actions of sitting workers performing assembly operations on electrical products in the Kani Plant Nagoya Works of Mitsubishi Electric Co. (Japan). The evaluation index used in the experiment was obtained by measuring time motion elements, cycle time per product, and motion velocity waves of elderly workers. Those motion characteristics were then compared to the motion characteristics of young workers. The results led to job redesign elements being identified to reduce handling factors of high difficulty for aged workers and to the necessity to consider a coefficient of correction in Method Time Measurement (MTM) according to differences in the manufactured object’s weight.  相似文献   
49.
Radiocarbon concentration in the atmosphere is significantly lower in areas where man-made emissions of carbon dioxide occur. This phenomenon is known as Suess effect, and is caused by the contamination of clean air with non-radioactive carbon from fossil fuel combustion. The effect is more strongly observed in industrial and densely populated urban areas. Measurements of carbon isotope concentrations in a study area can be compared to those from areas of clear air in order to estimate the amount of carbon dioxide emission from fossil fuel combustion by using a simple mathematical model. This can be calculated using the simple mathematical model. The result of the mathematical model followed in this study suggests that the use of annual rings of trees to obtain the secular variations of 14C concentration of atmospheric CO2 can be useful and efficient for environmental monitoring and modeling of the carbon distribution in local scale.  相似文献   
50.
A combination of sedimentological analysis of beach sands, field surveys and the assessment of the empirical methods for the breakwater design is used to investigate the impacts of offshore breakwaters on beach morphology along Nagahama and Ohgata. The results indicate that the nearshore sedimentation has been substantially disrupted due to the features formed behind the breakwaters stopping littoral transport, which led to sediment accretion on the updrift side of the breakwaters, and erosion on their downdrift side. Sedimentological analysis of beach sands made it possible to recognize the dominant process at the sections considered. In fact, the occurrence of strong offshore-going currents, the removal of finer mean grain size and the predominance of high-density heavy minerals led us to deduce that the two sections undergo a natural sedimentary imbalance.  相似文献   
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