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111.
Yagüe C Bayarri S Conchello P Lázaro R Pérez-Arquillué C Herrera A Ariño A 《Journal of agricultural and food chemistry》2005,53(13):5105-5109
A multicolumn solid-phase extraction cleanup for the determination of organophosphorus (OP) and organochlorine (OC) pesticides plus PCB congeners in virgin olive oil is presented. The method involves dissolution of the olive oil in hexane, followed by a cleanup system using a diatomaceous earth column (Extrelut-QE) with reversed (C(18)) and normal (alumina) phase SPE columns. Determination of OPs was by GC-NPD, while the OCs and PCBs were analyzed using GC-ECD. Recovery assays for OPs varied from 81.7% to 105.3%, for OCs ranged between 74.3% and 99.4%, while for PCBs were from 60.1% to 119.2%. Quantitation limits ranged from 10 to 25 microg/kg olive oil for OPs, and from 1 to 6 microg/kg olive oil for OCs and PCBs. In the case of positive samples, the confirmation of pesticide identity was performed by ion-trap GC-MS/MS. The applicability of the method was assayed with 19 virgin olive oil samples collected from different olive mills of Aragón (Spain). Only one OP pesticide (acephate) was detected in one sample at a concentration of 10 microg/kg. Organochlorine pesticides were found in 5-47% of samples at very low levels ranging from 1.5 to 5.2 microg/kg. PCBs were found in 20-90% of samples, showing concentrations between 2.3 and 17.3 microg/kg. 相似文献
112.
Gallart M López-Tamames E Suberbiola G Buxaderas S 《Journal of agricultural and food chemistry》2002,50(24):7042-7045
The influence of fatty acids (free and bound as ethyl esters) on wine foaming was studied in different white wines and the corresponding sparkling wines. Moreover, from three of these wines the foam formed by CO(2) injection was separated, and two fractions were then obtained: foam wine (FW) and remainder wine (RW). In these fractions and the sparkling wines produced from them, foam properties and fatty acids were also determined. The free fatty acids C8, C10, and C12 were negatively correlated with foamability (HM), whereas the ethyl esters of hexanoic, octanoic, and decanoic acids were positively related to HM. The value of HM was directly proportional to the ratio of esterified to unesterified fatty acids. This was confirmed by the changes that occur in the esterification ratio during the second fermentation and aging. No influence was observed on either the Bikerman coefficient or the stability time of foam. 相似文献
113.
Jean D Picandet V Céleste C Macieira S Cesarini C Morisset S Rossier Y Marcoux M 《The Canadian veterinary journal. La revue veterinaire canadienne》2011,52(11):1203-1208
This retrospective study evaluated the efficacy and side effects of palatal sclerotherapy in standardbred racehorses suspected to have intermittent dorsal displacement of the soft palate (IDDSP). Fifty-one horses were treated with multiple endoscopically guided injections of 3% sodium tetradecyl sulfate in the soft palate. Two groups were identified: those that had respiratory noises during exercise (n = 27) and those that did not (n = 24). Treatment was well-tolerated. Furthermore, horses significantly reduced their racing times for the last 400 m compared with their times before treatment and even when their times were compared to the mean times for horses in the same race. In conclusion, palatal sclerotherapy appears to be a suitable alternative therapeutic option for horses suspected to have IDDSP. 相似文献
114.
Matito C Agell N Sanchez-Tena S Torres JL Cascante M 《Journal of agricultural and food chemistry》2011,59(9):4489-4495
UV radiation leads to the generation of reactive oxygen species (ROS). These molecules exert a variety of harmful effects by altering key cellular functions and may result in cell death. Several studies have demonstrated that human skin can be protected against UV radiation by using plant-derived antioxidants. Here we evaluated the in vitro capacity of several antioxidant polyphenolic fractions from grape, which differ in their degree of polymerization and percentage of galloylation, to protect HaCaT human keratinocytes against UV-induced oxidative damage. These fractions inhibited both basal and UVB- or UVA-induced intracellular ROS generation in this cell line. Consequently, the same fractions inhibited p38 and JNK1/2 activation induced by UVB or UVA radiation. The highest protective effect was for fractions rich in procyanidin oligomers and gallate esters. These encouraging in vitro results support further research and should be taken into consideration into the clinical pharmacology of plant-derived polyphenolic extracts as novel agents for skin photoprotection. 相似文献
115.
The influence of watershed land use on microzooplankton was examined. Six rivers and a shallow lake located in rural (agriculture, livestock) and urban areas were sampled during 4 weeks at low water, low temperatures and 3 weeks at high water, high temperatures. The major aim of this study was to analyze the composition, richness and abundance of the microzooplankton in relation to land use, taking into account nutrient concentration, biological oxygen demand (BOD5), conductivity, pH, transparency, dissolved oxygen, and chlorophyll-a. Redundancy analysis was used to assess microzooplankton response to environmental gradients. The composition and abundance can be considered good indicators of the land used and characteristic of the basin (broad range of conductivity water). The species composition show a gradient along the conductivity, pH and chlorophyll-a. Brachionus spp. were associated with saline waters on rural area and Keratella spp. (except Keratella tropica) were associated with urban water bodies. The microzooplankton abundance diminished by a factor of ten from the rivers in livestock?Cagriculture-dominated watersheds to those located in strictly urban areas. Urban rivers had low abundances of chlorophyll-a and microzooplankton despite the high concentration of nutrients. However, the effect of urbanization (mesotrophic/mesosaprobious state and lead presence) cannot be analyzed alone due to the potential effect of a filter-feeding invasive mollusk that colonizes the hard surfaces of harbor buildings and bridge pillars. 相似文献
116.
Ana Belen Vicente Susana Pallares Amparo Soriano Teofilo Sanfeliu Manuel Miguel Jordan 《Water, air, and soil pollution》2011,222(1-4):149-161
The relationship between ambient concentrations of fine particulate matter and detrimental health effects remains a highly controversial issue. Increased incidence of mortality and morbidity due to cardiopulmonary complications has been associated with elevated levels of urban air particles with an aerodynamic of <2.5 ??m (PM2.5). The main aim of this paper was to present the assessment of the temporal and spatial variations of the PM2.5 fraction and its contents in arsenic, cadmium, nickel and lead in order to identify possible emission sources of these pollutants. Daily ambient aerosol samples (PM2.5) were taken in the province of Castellón from 2008 to 2009. Particle concentration levels were determined by gravimetry, and the As, Cd, Ni and Pb levels in the samples were determined by inductively coupled plasma mass spectroscopy. The season variation of these pollutants differs according to the emission source and the factors involved in dispersion. In the weekly trend, there were no significant differences in levels among sampling sites in relation to the day activity (working vs. non-working) due to chemical pollutants that are found in fine particulate fractions residing in the atmosphere longer than coarse particles, resulting in a more homogeneous concentration of pollutants over time. In order to identify similar behaviour between chemical pollutants and PM2.5, an assessment of the correlation between them was carried out. This behaviour study shows whether the source of contaminants is the same. A statistical analysis of the levels of PM2.5 and the presence of As, Cd, Ni and Pb in the different sampling sites was performed in order to evaluate the influence of the sampling point on the concentrations of these pollutants. 相似文献
117.
Rolle L Gerbi V Schneider A Spanna F Río Segade S 《Journal of agricultural and food chemistry》2011,59(19):10624-10634
The main aims of this work were to classify 30 colored and white wine grape varieties according to the berry skin hardness, to assess the influence of annual variations in climate on the berry skin hardness, and to establish significant relationships among berry skin mechanical properties and some climatic-bioclimatic indices calculated for different grape-ripening periods, close to the harvest date. The results obtained show that the most influential bioclimatic indices on the skin mechanical attributes were temperature parameters. In the same season, the influence of the production area was also evaluated, precipitation parameters being the best correlated with the berry skin hardness. This first work has permitted us to know the relationship among skin texture characteristics and seasonal climatic indices. 相似文献
118.
Two specific sites for binding of K88ab Escherichia coli fimbriae to porcine intestinal brush border membranes 总被引:1,自引:0,他引:1
We have studied the characteristics of the binding of the K88ab Escherichia coli fimbrial antigen to porcine brush border membranes by solid phase binding assay. Binding of biotinylated K88ab to brush border membranes followed a sigmoidal dependence and was saturable, apparent saturation occurring with 0.8 ng of fimbriae (approx. 7 ng of fimbriae per microg of brush border protein) irrespective of incubation temperature in the range of room temperature to 4 degrees C. A Hill plot of log [(fimbriae bound)/(maximal binding-fimbriae bound)] vs. log free fimbriae gave a maximal slope of about 2, indicating the existence of two binding sites. From an analysis of an Scatchard plot, apparent binding constants (1)K(2) and (2)K(2) of 7.1 x 10(8) and 17.1 x 10(8)M(-1) were obtained at room temperature. Nor did temperature have any effect on the rate of binding or on receptor affinity (S(0.5)). 相似文献
119.
Castillo M Martín-Orúe SM Nofrarías M Manzanilla EG Gasa J 《Veterinary microbiology》2007,124(3-4):239-247
An experiment was designed to monitor the changes in caecal microbiota associated with early weaning. Twelve piglets (20+/-2 days) from six different litters were selected from a commercial source. For the two experimental groups, one animal from each litter was weaned onto a post-weaning diet (W) and the other remained with the sow (S). After 1 week, animals were sacrificed and caecal samples taken. Microbial counts for total bacteria, enterobacteria and lactobacilli populations were determined by quantitative PCR using SYBR Green dye. Microbial profiles were assessed by terminal restriction fragment length polymorphism (t-RFLP). Weaning promoted an increase in the enterobacteria:lactobacilli ratio (0.27 versus 1.67 log/log 16S rRNA gene copy number, P=0.05). Total bacteria and richness of the caecal microbial ecosystem (number of peaks) were similar in both experimental groups (49.3 for S and 53.4 for W, respectively, P=0.22), although the band patterns were clearly grouped in two different clusters by dendogram analysis. Weaning was also associated with a decrease in crypt density, an increase in mytotic index and a decrease in the number of goblet cells. A reduced immunological response was also observed and was manifested by an increase in intraepithelial lymphocytes and lymphocyte density in the lamina propria. Weaning appears to be critical in the establishment of the caecal microbiota in pigs with important changes, particularly in microbial groups and in caecal mucosal architecture. 相似文献
120.
Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline
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Annette E. SIEG Megan M. GAMBONE Bryan P. WALLACE Susana CLUSELLA‐TRULLAS James R. SPOTILA Harold W. AVERY 《Integrative zoology》2015,10(3):282-294
Desert resource environments (e.g. microclimates, food) are tied to limited, highly localized rainfall regimes which generate microgeographic variation in the life histories of inhabitants. Typically, enhanced growth rates, reproduction and survivorship are observed in response to increased resource availability in a variety of desert plants and short‐lived animals. We examined the thermal ecology and reproduction of US federally threatened Mojave desert tortoises (Gopherus agassizii), long‐lived and large‐bodied ectotherms, at opposite ends of a 250‐m elevation‐related rainfall cline within Ivanpah Valley in the eastern Mojave Desert, California, USA. Biophysical operative environments in both the upper‐elevation, “Cima,” and the lower‐elevation, “Pumphouse,” plots corresponded with daily and seasonal patterns of incident solar radiation. Cima received 22% more rainfall and contained greater perennial vegetative cover, which conferred 5°C‐cooler daytime shaded temperatures. In a monitored average rainfall year, Cima tortoises had longer potential activity periods by up to several hours and greater ephemeral forage. Enhanced resource availability in Cima was associated with larger‐bodied females producing larger eggs, while still producing the same number of eggs as Pumphouse females. However, reproductive success was lower in Cima because 90% of eggs were depredated versus 11% in Pumphouse, indicating that predatory interactions produced counter‐gradient variation in reproductive success across the rainfall cline. Land‐use impacts on deserts (e.g. solar energy generation) are increasing rapidly, and conservation strategies designed to protect and recover threatened desert inhabitants, such as desert tortoises, should incorporate these strong ecosystem‐level responses to regional resource variation in assessments of habitat for prospective development and mitigation efforts. 相似文献