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Ferreira Leide Lene C. Abreu Marina P. Costa Camila B. Leda Paulo O. Behrens Maria Dutra dos Santos Elisabete Pereira 《Food and environmental virology》2022,14(2):120-137
Food and Environmental Virology - The use of natural resources for the prevention and treatment of diseases considered fatal to humanity has evolved. Several medicinal plants have nutritional and... 相似文献
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do A Kehrig H Seixas TG Palermo EA Baêta AP Castelo-Branco CW Malm O Moreira I 《Environmental science and pollution research international》2009,16(1):10-24
Background, aim, and scope Selenium (Se) has been shown to reduce mercury (Hg) bioavailability and trophic transfer in aquatic ecosystems. The study
of methylmercury (MeHg) and Se bioaccumulation by plankton is therefore of great significance in order to obtain a better
understanding of the estuarine processes concerning Hg and Se accumulation and biomagnification throughout the food web. In
the western South Atlantic, few studies have documented trace element and MeHg in fish tissues. No previous study about trace
elements and MeHg in plankton has been conducted concerning tropical marine food webs. Se, Hg, and MeHg were determined in
two size classes of plankton, microplankton (70–290 μm) and mesoplankton (≥290 μm), and also in muscle tissues and livers
of four fish species of different trophic levels (Mugil liza, a planktivorous fish; Bagre spp., an omnivorous fish; Micropogonias furnieri, a benthic carnivorous fish; and Centropomus undecimalis, a pelagic carnivorous fish) from a polluted estuary in the Brazilian Southeast coast, Guanabara Bay. Biological and ecological
factors such as body length, feeding habits, and trophic transfer were considered in order to outline the relationships between
these two elements. The differences in trace element levels among the different trophic levels were investigated.
Materials and methods Fish were collected from July 2004 to August 2005 at Guanabara Bay. Plankton was collected from six locations within the bay
in August 2005. Total mercury (THg) was determined by cold vapor atomic absorption spectrometry (CV-AAS) with sodium borohydride
as a reducing agent. MeHg analysis was conducted by digesting samples with an alcoholic potassium hydroxide solution followed
by dithizone-toluene extraction. MeHg was then identified and quantified in the toluene layer by gas chromatography with an
electron capture detector (GC-ECD). Se was determined by AAS using graphite tube with Pin platform and Zeeman background correction.
Results and discussion Total mercury, MeHg, and Se increased with plankton size class. THg and Se values were below 2.0 and 4.8 μg g−1 dry wt in microplankton and mesoplankton, respectively. A large excess of molar concentrations of Se in relation to THg was
observed in both plankton size class and both fish tissues. Plankton presented the lowest concentrations of this element.
In fish, the liver showed the highest THg and Se concentrations. THg and Se in muscle were higher in Centropomus undecimalis (3.4 and 25.5 nmol g−1) than in Micropogonias furnieri (2.9 and 15.3 nmol g−1), Bagre spp (1.3 and 3.4 nmol g−1) and Mugil liza (0.3 and 5.1 nmol g−1), respectively. The trophic transfer of THg and Se was observed between trophic levels from prey (considering microplankton
and mesoplankton) to top predator (fish). The top predators in this ecosystem, Centropomus undecimalis and Micropogonias furnieri, presented similar MeHg concentrations in muscles and liver. Microplankton presented lower ratios of methylmercury to total
mercury concentration (MeHg/THg) (34%) than those found in mesoplankton (69%) and in the muscle of planktivorous fish, Mugil liza (56%). The other fish species presented similar MeHg/THg in muscle tissue (of around 100%). M. liza showed lower MeHg/THg in the liver than C. undecimalis (35%), M. furnieri (31%) and Bagre spp. (22%). Significant positive linear relationships were observed between the molar concentrations of THg and Se in the
muscle tissue of M. furnieri and M. liza. These fish species also showed significant inverse linear relationships between hepatic MeHg and Se, suggesting a strong
antagonistic effect of Se on MeHg assimilation and accumulation.
Conclusions Differences found among the concentrations THg, MeHg, and Se in microplankton, mesozooplankton, and fishes were probably related
to the preferred prey and bioavailability of these elements in the marine environment. The increasing concentration of MeHg
and Se at successively higher trophic levels of the food web of Guanabara Bay corresponds to a transfer between trophic levels
from the lower trophic level to the top-level predator, suggesting that MeHg and Se were biomagnified throughout the food
web. Hg and Se were positively correlated with the fish standard length, suggesting that larger and older fish bioaccumulated
more of these trace elements. THg, MeHg, and Se were a function of the plankton size.
Recommendations and perspectives There is a need to assess the role of selenium in mercury accumulation in tropical ecosystems. Without further studies of
the speciation of selenium in livers of fishes from this region, the precise role of this element, if any, cannot be verified
in positively affecting mercury accumulation. Further studies of this element in the study of marine species should include
liver samples containing relatively high concentrations of mercury. A basin-wide survey of selenium in fishes is also recommended. 相似文献
3.
Susana Viegas Mário Pádua Ana Costa Veiga Elisabete Carolino Mário Gomes 《Environmental monitoring and assessment》2014,186(11):7807-7818
Despite the classification as known or suspected human carcinogens, by the International Agency for Research on Cancer, the antineoplastic drugs are extensively used in cancer treatment due to their specificity and efficacy. As human carcinogens, these drugs represent a serious threat to the healthcare workers involved in their preparation and administration. This work aims to contribute to better characterize the occupational exposure of healthcare professionals to antineoplastic drugs, by assessing workplace surfaces contamination of pharmacy and administration units of two Portuguese hospitals. Surface contamination was assessed by the determination of cyclophosphamide, 5-fluorouracil, and paclitaxel. These three drugs were used as surrogate markers for surfaces contamination by cytotoxic drugs. Wipe samples were taken and analyzed by HPLC-DAD. From the total of 327 analyzed samples, in 121 (37 %) was possible to detect and quantify at least one drug. Additionally, 28 samples (8.6 %) indicate contamination by more than one antineoplastic drug, mainly in the administration unit, in both hospitals. Considering the findings in both hospitals, specific measures should be taken, particularly those related with the promotion of good practices and safety procedures and also routine monitoring of surfaces contamination in order to guarantee the appliance of safety measures. 相似文献
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Maria Elisabete F. Silva Luís Teixeira de Lemos Olga C. Nunes Ana Cristina Cunha-Queda 《Waste management (New York, N.Y.)》2014,34(1):21-27
The influence of the proportion of C- and N-rich raw materials (initial C/N ratio) and bulking agent on the chemical functional groups composition, humic-like substances (HS-like) content and physicochemical properties of composts was assessed. To achieve these goals, seven initial mixtures (BA1–6 and C1) of dog food (N-rich raw material) were composted with wheat flour (C-rich raw material). Composts were analyzed in terms of chemical functional groups, physicochemical, maturity and stability parameters.The C-rich raw material favored the formation of oxidized organic matter (OM) during the composting process, as suggested by the variation of the ratios of the peaks intensity of FT-IR spectra, corresponding to a decrease of the polysaccharides and an increase of aromatic and carboxyl-containing compounds. However, although with high proportion of C-rich raw material, mixtures with low initial C/N seems to have favored the accumulation of partially oxidized OM, which may have contributed to high electrical conductivity values in the final composts. Therefore, although favoring the partial transformation of OM into stabilized HS-like, initial mixtures with high proportion of C-rich raw material but with low initial C/N led to unstable composts.On the other hand, as long as a high percentage of bulking agent was used to promote the structure of biomass and consequently improve of the aeration conditions, low initial C/N was not a limiting factor of OM oxidation into extractable stabilized humic-like acids. 相似文献
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Bioaccumulation of Cd by a European lacertid lizard after chronic exposure to Cd-contaminated food 总被引:1,自引:0,他引:1
Apart from analyses for elemental contaminants in field collected specimens, very little is known about the assimilation, accumulation and toxic effects of inorganic contaminants in reptiles. This study examined the chronic accumulation of Cd in a European lacertid lizard (Podarcis carbonelli) following dietary provision of an environmentally realistic concentration of Cd for 21 weeks. Lizards were provided with Cd that had either been biologically incorporated into crickets, or as Cd(NO3)2 added superficially to crickets just prior to feeding. Among both treatment groups Cd accumulated in tissues in the following order of concentration: gut>liver>kidney>carcass. The majority of the Cd was retained within the gut, and transfer to internal organs was low. Morphological indices, brain and plasma cholinesterase activities, gut and liver metallothionein content, and standard metabolic rate were measured as biomarkers of exposure and effect; however, no differences between control lizards and Cd-treated lizards were observed. 相似文献
8.
Macacini JF De Nadai Fernandes EA Taddei MH 《Environmental pollution (Barking, Essex : 1987)》2002,120(1):151-155
In case of an accident at a nuclear power plant with liberation of radioactive material into the atmosphere, knowledge about the behavior of plant species when in contact with radionuclides is indispensable for safety reasons. The leaf-fruit translocation is an important route through which agricultural products are contaminated by radionuclides. To quantify the leaf-fruit translocation factors for 137Cs and 90Sr in common beans (Phaseolus vulgaris) an experiment was carried out in a greenhouse with a randomized block design. 137Cs activity was determined by gamma-ray spectrometry, while chemical separation followed by beta counting of 90Y was used for 90Sr determination. The model applied for translocation indicated functional dependence between the moment of tracer application and the physiological development of the bean plant. Translocation factors obtained for 137Cs and 90Sr were 0.16 and less than 0.005, respectively. 相似文献
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Lodeiro Carlos Capelo-Martínez José Luis Santos Hugo M. Oliveira Elisabete 《Environmental science and pollution research international》2021,28(15):18309-18313
Environmental Science and Pollution Research - Every 2 years, the environmental, chemical, and health research communities meet in Costa de Caparica, Portugal to showcase the latest... 相似文献