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71.
Results of red tide formation in Tokyo Bay   总被引:2,自引:0,他引:2  
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72.
Impact of FEBRA (fermented brown rice with Aspergillus oryzae, a rich dietary fiber) intake on the concentrations of polychlorinated-biphenyls (PCBs), -dioxin-like polychlorinated biphenyls (DLPCBs), -dibenzo-p-dioxins (PCDDs), and -dibenzofurans (PCDFs) in blood of nine married Japanese were studied for 2 years. Concentrations of total PCBs (average+/-standard deviation) were greater 326,000+/-263,000 and 207,000+/-89,000 in FEBRA-intake and non-FEBRA-intake groups, respectively, on pg/g lipid (from now onwards data expressed on pg/g lipid). DLPCBs were second major contaminants 94,000+/-77,000 and 60,000+/-28,000, orderly in FEBRA-intake and non-FEBRA-intake groups. The concentrations of PCDD/DFs were several orders of magnitude lower than those of PCBs, whereas PCDDs were greater (433+/-233 and 512+/-511, in FEBRA-intake and non-FEBRA-intake groups, respectively) than PCDFs (56+/-50 and 43+/-35). Calculated toxic equivalency (TEQ) concentrations were 34+/-24 and 23+/-10 in FEBRA-intake and non-FEBRA-intake groups, respectively. In order to corroborate the impact of FEBRA, the changes of PCDD/DFs and PCB concentrations for 0.5-year, 1-year, 1.5-year, and 2-year samples were estimated from average concentration of 1-day before study commences and 1-week study samples. The results explicit FEBRA-intake group eliminated 7%, 33%, 45%, 36%, and 26% and non-FEBRA-intake group eliminated 8%, 28%, 36%, 31%, and 20% of DLPCBs, PCDDs, PCDFs, PCDD/DF TEQ and total TEQ, respectively. This study is the first of its kind showing the possible elimination of PCDDs, PCDFs and their TEQ in humans from Japan after the consumption of FEBRA.  相似文献   
73.
The poly(-caprolactone) (PCL) and poly[(R)-3-hydroxybutyrate] (R-PHB) films with a hydrophilic surface were prepared by the alkali treatment of their as-cast films in NaOH solutions of different concentrations. The alkali-treated PCL and R-PHB films, as well as the as-cast PCL and R-PHB films, were biodegraded in soil controlled at 25°C and the effects of alkali treatment or surface hydrophilicities on their biodegradation were investigated by the use of gravimetry, gel permeation chromatography (GPC), scanning electron microscopy (SEM), and polarization optical microscopy. It became evident that the alkali treatment enhanced the hydrophilicities and biodegradabilities of the PCL and R-PHB films in soil. The biodegradabilities of the as-cast aliphatic polyester films in controlled soil decreased in the following order: PCL > R-PHB > PLLA, in agreement with that in controlled static seawater.  相似文献   
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Surveys of 4-nonylphenols (NOs) and 4-tert-octylphenol (OC) were performed for water and fish samples obtained from eight rivers flowing into Lake Biwa once every two months from April 1998 to March 1999. For water samples, NOs were detected all the year round (0.11-3.08 ng ml(-1)) at high frequency (48/48) in the eight rivers. OC was detected at lower concentrations (ND approximately 0.09 ng ml(-1)) and at lower frequency (23/48). The concentrations of NOs in the river water always showed minimum values at 5-8 degrees C in winter. It was presumed that the formation of NOs by the biotransformation of nonylphenol polyethoxylates decreased much in the sludge treatment of nonionic surfactants at the low temperature (5-8 degrees C) in winter. Average BCF values of NOs and OC in the six kinds of fish were calculated from the field data. The field BCF values of NOs 15-31 in the six kinds of fish were lower than the laboratory BCF values of 167 in Killifish and 282 in Salmon. For OC, the field BCF values 129-297 for the three kinds of fish were nearly equal to the laboratory BCF value, 261, in Killifish.  相似文献   
77.
Evolution of caste is a central issue in the biology of social insects. Comparative studies on their morphology so far suggest the following three patterns: (1) a positive correlation between queen–worker size dimorphism and the divergence in reproductive ability between castes, (2) a negative correlation among workers between morphological diversity and reproductive ability, and (3) a positive correlation between queen–worker body shape difference and the diversity in worker morphology. We conducted morphological comparisons between castes in Pachycondyla luteipes, workers of which are monomorphic and lack their reproductive ability. Although the size distribution broadly overlapped, mean head width, head length, and scape length were significantly different between queens and workers. Conversely, in eye length, petiole width, and Weber’s length, the size differences were reversed. The allometries (head length/head width, scape length/head width, and Weber’s length/head width) were also significantly different between queens and workers. Morphological examinations showed that the body shape was different between queens and workers, and the head part of workers was disproportionately larger than that of queens. This pattern of queen–worker dimorphism is novel in ants with monomorphic workers and a clear exception to the last pattern. This study suggests that it is possible that the loss of individual-level selection, the lack of reproductive ability, influences morphological modification in ants.  相似文献   
78.
Environmental Science and Pollution Research - We assessed the contamination, dynamics, and health risks of the pesticides cyanazine, simetryn, fenarimol, isoprothiolane, diazinon, irgarol,...  相似文献   
79.
Humic acids (HA) didn’t cause obvious reverse osmosis (RO) membrane fouling in 45 h. Osmotic pressure (NaCl) affected slightly the RO membrane fouling behavior of HA. Ca2+ promoted aggregation of HA molecules and thus aggravated RO membrane fouling. Ozonation eliminated the effect of Ca2+ on the RO membrane fouling behavior of HA. The change of the structure of HA was related to its membrane fouling behavior. Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the change of its molecular structure has not been well developed yet. In this study, the RO membrane fouling behavior of humic acid was studied systematically with ozonation as a pretreatment method to control RO membrane fouling. Furthermore, the effect of ozone on the structure of humic acid was also explored to reveal the mechanisms. Humic acid alone (10–90 mg/L, in deionized water) was found not to cause obvious RO membrane fouling in 45-h operation. However, the presence of Ca2+ aggravated significantly the RO membrane fouling caused by humic acid, with significant flux reduction and denser fouling layer on RO membrane, as it was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). However, after the pretreatment by ozone, the influence of Ca2+ was almost eliminated. Further analysis revealed that the addition of Ca2+ increased the particle size of humic acid solution significantly, while ozonation reduced the SUVA254, particle size and molecular weight of the complexes of humic acid and Ca2+ (HA-Ca2+ complexes). According to these results and literature, the bridge effect of Ca2+ aggregating humic acid molecules and the cleavage effect of ozone breaking HA-Ca2+ complexes were summarized. The change of the structure of humic acid under the effect of Ca2+ and ozone is closely related to the change of its membrane fouling behavior.  相似文献   
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