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461.
462.
Francesco Bagordo Tiziana Grassi Adele Idolo Francesca Serio Giovanni Gabutti Antonella De Donno 《Food and environmental virology》2013,5(3):169-175
The purpose of this study was to evaluate “in field” the accumulation of virus in shellfish and compare it with the concentration of bacterial indicators. Individuals of Mytilus galloprovincialis were placed in two sampling station located in a contaminated coastal bay and in one control station located one kilometer offshore. The presence of Rotavirus and E. coli was assessed weekly both in seawater and in shellfish samples. The Rotavirus genome was detected in water, preliminarily concentrated by tangential flow ultrafiltration method, and in hepatopancreas of mussels by Real-Time PCR. E. coli was enumerated in water matrices by a filtering method and in mussels by the MPN method. Rotaviruses were not recorded in seawater, while in mussels they were detected since third week after placement. E. coli in mussels were always below the limits set in the Regulation (EC) 854/2004. This study suggests the need for a viral indicator to insure the safety for consumption of shellfish. 相似文献
463.
We report the chemical composition of PM10-associated water-soluble species in Mexico City during the second semester of 2000. PM10 samples were collected at four ambient air quality monitoring sites in Mexico City. We determined soluble ions (chloride, nitrate, sulfate, ammonium, sodium, potassium), ionizable transition metals (Zn, Fe, Ti, Pb, Mn, V, Ni, Cr, Cu) and soluble protein. The higher PM(10) levels were observed in Xalostoc (45-174 microg m(-3)) and the lowest in Pedregal (19-54 microg m(-3)). The highest SO2 average concentrations were observed in Tlalnepantla, NO2 in Merced and O3 and NO(x) in Pedregal. The concentration range of soluble sulfate was 6.7-7.9 and 19-25.5 microg m(-3) for ammonium, and 14.8-29.19 for soluble V and 3.2-7.7 ng m(-3) for Ni, suggesting a higher contribution of combustion sources. PM-associated soluble protein levels varied between 0.038 and 0.169 mg m(-3), representing a readily inhalable constituent that could contribute to adverse outcomes. The higher levels for most parameters studied were observed during the cold dry season, particularly in December. A richer content of soluble metals was observed when they were expressed by mass/mass units rather than by air volume units. Significant correlations between Ni-V, Ni-SO4(-2), V-SO4(-2), V-SO2, Ni-SO2 suggest the same type of emission source. The variable soluble metal and ion concentrations were strongly influenced by the seasonal meteoclimatic conditions and the differential contribution of emission sources. Our data support the idea that PM10 mass concentration by itself does not provide a clear understanding of a local PM air pollution problem. 相似文献
464.
Temporal variations of polycyclic aromatic hydrocarbon (PAH) concentrations in leaves of a Mediterranean evergreen oak, Quercus ilex L., were investigated in order to assess the suitability of this species to biomonitor PAH air contamination. Leaf samples were collected at six sites of the urban area of Naples (Italy) and at a control site in the Vesuvius National Park, in May and September 2001, and in January and May 2002. PAH extraction was conducted by sonication in dichloromethane-acetone and quantification by GC-MS. In winter, leaf total PAH concentrations showed, at all the urban sites, values 2-fold higher than in all the other samplings, reflecting the temporal trend reported for PAH air contamination in the Naples urban area. Moreover, leaf PAH concentrations showed, at all the urban sites, a decrease in May 2002 after the winter accumulation. At the control site leaf PAH concentrations showed lower values and smaller temporal variations than at the urban sites. The findings support the suitability of Q. ilex leaves to monitor temporal variations in PAH contamination. The highest winter concentrations of total PAHs were due to the medium molecular weight PAHs that increased with respect to both low and high molecular weight PAHs. The medium molecular weight PAHs showed the same temporal trend both at the urban and remote sites. 相似文献
465.
Karel De Greef Frans Stafleu Carolien De Lauwere 《Journal of Agricultural and Environmental Ethics》2006,19(1):57-66
Public debate on acceptable farm animal husbandry suffers from a confusion of tongues. To clarify positions of various stakeholder
groups in their joint search for acceptable solutions, the concept of animal welfare was split up into three notions: no suffering,
respect for intrinsic value, and non-appalling appearance of animals. This strategy was based on the hypothesis that multi-stakeholder
solutions should be based on shared values rather than on compromises. The usefulness of such an artificial value distinction
strategy was tested in a small series of experiments. The results demonstrate that the chosen concept to distinguish between
values is effective in a stakeholder context. Farmers’ views on doing good to animals appeared to be largely based on their
value to prevent suffering and predominantly focused on the provision of regular care. Their priority for this value is clearly
shared with other stakeholders, providing a basis for joint solutions. The concept of intrinsic value does not play a discernable
role in farmers’ considerations. Based on the varying views on welfare, it can be inferred that there is a gradual rather
than a principal difference between government legislation and farmers’ values, whereas public perception and acceptance of
farm practices remains complicated. Distinction between value groups and focusing on a selected notion (such as no suffering)
proved to be effective in bringing representatives of stakeholder groups together, but is unlikely to bridge the emotional
gap between commercial farm practices and public ideals. 相似文献
466.
467.
Investigation of the Aerobic Biodegradability of Several Types of Cyclodextrins in a Laboratory-Controlled Composting Test 总被引:1,自引:0,他引:1
Steven Verstichel Bruno De Wilde Eva Fenyvesi József Szejtli 《Journal of Polymers and the Environment》2004,12(2):47-55
The biodegradation of several types of cyclodextrins (CDs) under laboratory-controlled composting conditions was investigated. CDs are used in a broad range of applications in food, pharmaceutical, medical, chemical, and textile industries because of their specific chemical characteristics related to their hydrophobic interior and hydrophilic exterior. The three naturally occurring cyclodextrins -CD, -CD, and -CD proved to be completely and readily biodegradable. Chemical modification of these basic compounds can have a major impact on the biodegradation rate and final biodegradation percentage. Fully acetylated -CD and -CD were found to be nonbiodegradable during 45 days of composting. Reducing the degree of acetylation had a positive effect on the biodegradation. Complete biodegradation was obtained for partially acetylated -CD with a degree of substitution (DS) of 7. The methylation (DS = 13) of -CD resulted in an undegradable compound during the 47 days composting, while (2-hydroxy)propyl--CD reached a plateau in biodegradation at a percentage of 20%. The incorporation of the antimicrobial agents imazalil and allyl-isothiocyanate into -CD had no negative impact on biodegradation, which makes these antimicrobial agents/CD complexes suitable for incorporation into biodegradable active packaging. 相似文献
468.
Van Hulle M De Cremer K Cornelis R Lameire N 《Journal of environmental monitoring : JEM》2001,3(1):86-90
Five Wistar rats were given an intraperitoneal injection of [114mIn]InCl3 during four consecutive days. One hour after the last injection the rats were sacrificed. The in vivo distribution of 114mIn was studied in the blood and in different organs. Differential centrifugation was used to study the distribution in liver, kidney and spleen homogenate. Rat serum, packed cell lysate, urine and the cytosol of liver, kidney and spleen homogenate were examined by size exclusion fast protein liquid chromatography. The results showed that serum accounts for 90% of the indium activity in whole blood. Indium is preferentially accumulated within the liver, spleen and kidney, the highest amount of 114mIn being localised in the cytosolic fraction followed by the mitochondria. Size exclusion experiments showed that, in rat serum, indium is exclusively bound to transferrin. These results differed from earlier in vitro incubation experiments of human serum with 114mIn. It was not possible, from the experiments described herein, to conclude unequivocally whether indium is bound to haemoglobin of packed cell lysate or to another high molecular mass compound. Indium is associated with the high molecular mass fraction in liver, kidney and spleen cytosol; only in kidney are small amounts of 114mIn found in the low molecular mass fraction. The in vivo inhibitory effect of indium on the delta-aminolaevulinic acid dehydratase (ALAD) enzymatic activity in red blood cells and kidney tissue, well documented by other researchers, could not be attributed to direct binding of indium with this enzyme. 相似文献
469.
对武钢一管式炉2000年3月24日发生煤气爆燃事故进行了分析,结合管式炉周围现场情况,提出了避免此类事故再发生的防范措施。 相似文献
470.