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排序方式: 共有327条查询结果,搜索用时 15 毫秒
111.
Virginia Funes-Collado Roser Rubio José Fermín López-Sánchez 《Water, air, and soil pollution》2011,222(1-4):315-324
Several approaches have been used to estimate the bioaccessibility of trace metals from soils. Here, we applied phosphoric acid extraction and the in vitro test physiologically based extraction (PBET) to soils containing selenium (Se) and compared their performance in estimating the bioaccessibility of Se. For this purpose, we used two soil samples and two Certified Reference Material soil samples with a range of Se concentrations. The total Se contents were measured in the samples and in the extracts by hydride generation–atomic fluorescence spectroscopy. Moreover, we also measured selenite and selenate in the soil extracts (from phosphoric acid and from the PBET) using the coupled techniques liquid chromatography–UV photooxidation–atomic fluorescence spectroscopy and liquid chromatography–mass spectrometry with inductively coupled plasma. From the results obtained in the present study, the PBET showed that the selenium bioaccessible fraction was mainly attributed to the gastrointestinal step. When comparing the results from PBET with those of the phosphoric acid extraction, similar values of Se (IV) and Se (VI) were obtained for both extraction systems. An estimation of the bioaccessibility percentage of Se is also reported. 相似文献
112.
Loquat is a subtropical fruit tree that presents an annual cycle reverse to that of the well-known temperate fruit crops. Loquat rests during summer, blooms in autumn, develops its fruit through winter and ripens them in early spring. Its unusual phenology allows growers to obtain high prices for its fruits, especially for early harvests. Although loquat is harvested based on skin colour, a minimum soluble solid content (TSS) of 10° Brix is often required for commercialization. However, we have noticed that the relationship between skin colour and eating quality seems to change along the season leading costumers to complain for the high acidity of the earliest fruits. In order to establish a reliable maturity index, we have evaluated the changes in different fruit maturation parameters along the harvest period in four consecutive seasons for ‘Algerie’ loquat. The results show that in samples collected with similar skin colour, TSS and, especially, fruit titratable acidity (TA) tend to decline as harvest season progresses. This makes fruit skin colour on its own not suitable as a harvest index to assure an adequate fruit quality under all circumstances. We propose instead to monitor continuously TSS and TSS/TA ratio along the season in order to fulfill consumer's expectations. 相似文献
113.
Virginia?H.?DaleEmail author Rebecca?A.?Efroymson Keith?L.?Kline 《Landscape Ecology》2011,26(6):755-773
Landscape ecology focuses on the spatial patterns and processes of ecological and human interactions. These patterns and processes
are being altered by both changing resource-management practices of humans and changing climate conditions associated, in
part, with increases in atmospheric concentrations of greenhouse gases. Dominant resource-extraction and land-management activities
involve energy, and the use of fossil energy is one of the key drivers behind increasing greenhouse gas emissions as well
as land-use changes. Alternative energy sources (such as wind, solar, nuclear, and bioenergy) are being explored to reduce
greenhouse gas emission rates. Yet, energy production, including alternative-energy options, can have a wide range of effects
on land productivity, surface cover, albedo, and other factors that affect carbon, water, and energy fluxes and, in turn,
climate. Meanwhile, climate influences the potential output, relative efficiencies, and sustainability of alternative energy
sources. Thus, land use, climate change, and energy choices are linked, and any comprehensive analysis in landscape ecology
that considers one of these factors should be cognizant of these interactions. This analysis explores the implications of
linkages between land use, climate hange, and energy and points out ecological patterns and processes that may be affected
by their interactions. 相似文献
114.
Elizabeth J. Hammer DVM Kate Chope VMD Tanya D. Lemire DVM Virginia B. Reef DVM 《Veterinary radiology & ultrasound》2002,43(1):63-65
This report describes the identification and surgical removal of a lipoma from the extensor tendon sheaths of a horse. To the authors' knowledge, this is the first report of a lipoma of the extensor tendon sheaths of a horse. Ultrasonographic evaluation was crucial to patient management, providing information regarding the soft tissue mass characteristics, tumor margins and synovial involvement prior to surgical exploration. Surgical removal was performed and was curative. 相似文献
115.
Virginia Buechner-Maxwell Chonghui Zhang John Robertson N. C. Jain Douglas F. Antczak Bernard F. Feldman Michael J. Murray 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):258-263
Leukemia is a neoplastic disease of one or more of the cell types of the hemopoietic system and is rarely diagnosed in the horse. This report describes a case of subleukemic acute myelomonocytic leukemia in an 11 -year-old gelding. Preliminary cytological diagnosis was supported by two types of laboratory investigations. Cytochemical characterization of blood and bone marrow neoplastic cells was consistent with a myelomonocytic origin. Neoplastic blast cells in peripheral blood were labeled by monoclonal antibodies specific for cell surface molecules of horse granulocytes, but they were not labeled by antibodies to T- or B-lymphocytes or macrophages. Treatment was attempted but was unsuccessful. At necropsy, intravascular leukostasis was present in all tissues examined. Fungal hyphae were also found in lung interstitium and colonic submucosa, suggesting the presence of a systemic mycosis. Nucleated cells were isolated from peripheral blood and cultured in vitro; they survived for up to 2 weeks and had evidence of cell division that was not sustained. Frozenthawed cells stored in liquid nitrogen were also successfully cultured in vitro, but no permanent cell lines could be established. 相似文献
116.
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118.
Xiao Jingxiu Yin Xinhua Sykes Virginia R. He Zhongqi 《Journal of Soils and Sediments》2022,22(3):844-858
Journal of Soils and Sediments - Heavy metal contamination in soil and crop grain due to long-term poultry litter (PL) application is largely unknown under no-till production and subtropical... 相似文献
119.
Ezequiel?Grondona Gerardo?Gatti Abel?G.?López Leonardo?Rodolfo?Sánchez Virginia?Rivero Oscar?Pessah María?P.?Zunino Andrés?A.?PonceEmail author 《Plant foods for human nutrition (Dordrecht, Netherlands)》2014,69(4):351-357
The aim of this study was to investigate the bioactivity of the essential oil isolated from Origanum vulgare L. (EOv). We analyzed the in vivo anti-inflammatory properties in a mouse-airway inflammation model and the in vitro antimicrobial activity, genotoxicity over the anaphase-telophase with the Allium cepa strain and its cytotoxicity/viability in A549 culture cells. In vivo, EOv modified the levels of tumor necrosis factor -α and viable activated macrophages and was capable to mitigate the effects of degradation of conjugated dienes. In vitro, EOv reduced the viability of cultured A549 cells as well as the mitotic index and a number of chromosomal aberrations; however, it did not change the number of phases. We found that EOv presents antimicrobial activity against different Gram (?) and (+) strains, measured by disc-diffusion test and confirmed with a more accurate method, the AutoCad software. We postulate that EOv presents antibacterial, antioxidant and chemopreventive properties and could be play an important role as bioprotector agent. 相似文献
120.
Copaciu Florina Opriş Ocsana Coman Virginia Ristoiu Dumitru Niinemets Ülo Copolovici Lucian 《Water, air, and soil pollution》2013,224(3):1-11
The use of aqueous suspension of nanoparticles of titanium dioxide for photocatalytic removal of pollutants is not suitable for industrial applications due to the inconvenient and expensive separation of nanoparticles of titanium dioxide for reuse. The nanosized titanium dioxide needs to be immobilized on the support for improving the efficiency and economics of the photocatalytic process. In the present paper, nanoparticles of titanium dioxide have been immobilized on the surface of the support using three different techniques. The immobilized films of titanium dioxide have been characterized using X-ray diffraction and scanning electron microscopy to notice any change in the phase composition and photocatalytic properties of the titanium dioxide after immobilization on the support. A photocatalytic test has been performed under similar reaction conditions to compare the photocatalytic performance of the films of immobilized titanium dioxide prepared using different techniques. 相似文献