首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   18篇
  免费   0篇
基础科学   2篇
  3篇
农作物   3篇
水产渔业   5篇
畜牧兽医   3篇
植物保护   2篇
  2021年   2篇
  2016年   1篇
  2013年   2篇
  2012年   3篇
  2011年   2篇
  2010年   2篇
  2008年   1篇
  2007年   1篇
  2005年   2篇
  2003年   1篇
  2002年   1篇
排序方式: 共有18条查询结果,搜索用时 31 毫秒
11.
12.
Hypertension development in the spontaneously hypertensive rat (SHR) leads to vascular wall widening by smooth muscle cell proliferation. In these cells, triglycerides (TG) and cholesteryl esters (CE) can accumulate until they become foam cells. We administrated two oleic rich oils, virgin olive (VOO) and high oleic sunflower oils (HOSO), to Wistar-Kyoto rats (WKY) and SHR because these oils have been reported to reduce the risk for coronary heart disease in hypertensive patients and SHR. After 12 weeks of feeding, we analyzed the TG and CE composition and the lipolytic (lipoprotein lipase, LPL, and non-LPL) activity in aortas of these animals. HOSO increased the content of linoleic acid in CE and TG of aortas from both WKY and SHR as compared with animals fed VOO by proportionally decreasing the content of oleic acid. Conversely, VOO reduced the LPL and non-LPL lipolytic activities, hence limiting the free fatty acids available for the synthesis of TG and CE in the vascular wall.  相似文献   
13.
Nixtamalization process is the first step to obtain maize based products, like tortillas; however, in both the traditional and commercial processes, white grain is generally preferred. Creole maize races, mainly pigmented varieties, have increasingly attention since these are rich in anthocyanins and carotenoids. The aim of this investigation was to evaluate the antioxidant and antimutagenic activity of rich anthocyanins and carotenoids extracts from creole maize races before (grain) and after (masa and tortilla) the nixtamalization process. Most anthocyanins and carotenoids were lost during nixtamalization. Before nixtamalization, blue and red genotypes contained either higher antioxidant capacity and anthocyanin contents (963?±?10.0 and 212.36?±?0.36 mg of cyanidin-3-glucoside eq/100 g, respectively) than the white and yellow genotypes. However, the highest carotenoid levels were displayed by red grains (1.01?±?0.07 to 1.14?±?0.08 μg of β-carotene eq/g extract). Anthocyanins losses were observed when the blue grains were processed into masa (83 %) and tortillas (64 %). Anthocyanins content correlated with antiradical activity (r?=?0.57) and with 2-aminoanthracene -induced mutagenicity inhibition on TA98 and TA100 (r?=??0.62 and r?=??0.44, respectively). For white grains, nixtamalization also reduced carotenoids (53 to 56 %), but not antioxidant activity and 2-Aa-induced mutagenicity. Throughout the nixtamalization process steps, all the extracts showed antimutagenic activity against 2-aminoanthracene—induced mutagenicity (23 to 90 %), displaying higher potential to inhibit base changes mutations than frameshift mutations in the genome of the tasted microorganism (TA100 and TA98, respectively). The results suggest that even though there were pigment losses, creole maize pigments show antioxidant and antimutagenic activities after nixtamalization process.  相似文献   
14.
The development of an automated recirculation aquaculture system (ARAS) is presented here. The production system facility was built in a 672-m2 polyethylene greenhouse using four 20-m3 tanks, each of which was stocked with 1,000 tilapia (O. niloticus). The growth of the fish was evaluated from a starting weight of 2 g to a final average weight of 418 g, during a production cycle from July 2008 to January 2009. Our objective was to develop new technological approaches, based on fuzzy logic control, to integrate into novel automated equipment for recirculation aquaculture systems used for fish production under intensive conditions. This technique allows farmers to incorporate their knowledge and experience into the control system. The results demonstrated a substantial water savings of 97.42%. There was a total fish biomass production of 1,655.3 kg and an average feed conversion rate of 1.55. The environmental variables were kept within acceptable ranges for tilapia production. We conclude that it is possible to increase the productivity and profitability of aquaculture systems, by applying new approaches based on modern control techniques, such as fuzzy logic control, that promote resource optimization.  相似文献   
15.
Regulated deficit irrigation strategies are common practices in areas with low water availability. Thus, water stress, which can limit fruit growth, is imposed to the trees. Fruit thinning can be used to relieve this water stress in peach. In this paper, the ability of an existing fruit tree model (QualiTree) for describing the effects of water stress and fruit thinning on peach fruit and vegetative growth was assessed. The model was parameterized and calibrated for a very early-maturing peach cultivar (“Flordastar”). Important parameters were those expressing the effect of distance between organs on carbon exchange within the tree, the potential dry masses, and the relative growth rates of fruits and leafy shoots. Then, the model was tested in a wide range of water stress situations and three fruit thinning intensities: no thinning, commercial thinning, and heavy thinning. Fruit and vegetative growth simulations were consistent with observed data derived from 2006 field experiments. The variability over time of fruit and vegetative growth was well predicted. The model reproduced reductions in fruit growth observed in field experiments. It also reacted to simulated scenarios that combined water stress and thinning. Increasing thinning intensity reduced total fruit yield but increased fruit size at harvest, compensating the negative effects of water stress on fruit growth. These simulations broadened the predictive capabilities of the model and showed that it might be a useful tool in the design of innovative horticultural practices.  相似文献   
16.
The present study characterizes, for the first time, two emerging avian pathogenic Escherichia coli (APEC) clonal groups of serogroup O111: O111:H4-D-ST117 and O111:H4-D-ST2085. The clonal group O111:H4-D-ST117 was already present in APEC strains isolated between 1991 and 2000, and was still present in strains isolated between 2004 and 2009, showing long time evolution according to the virulence-gene differences and macrorestriction profiles. Among ST117 strains, two virulence profiles could be distinguished: papG II-positive tsh-negative strains which satisfied criteria for extraintestinal pathogenic E. coli (ExPEC), and papG II-negative tsh-positive strains without ExPEC status. Interestingly, we have detected a human septicemic O111:H4-D-ST117 ExPEC strain isolated from a hemocultive in 2000 whose macrorestriction profile showed >85% similarity with four APEC strains of the study. The clonal group O111:H4-D-ST2085 was exclusively detected in 17 APEC strains isolated in 2008 and 2009, and showed short time evolution based on its homogeneity since all were nalidixic acid-resistant, all had ExPEC status, and most carried papG II and tsh genes. From the clinical point of view, O111:H4-D-ST2085 seems a successful clonal group that could be the result of the epidemiological evolution of O111:H4-D-ST117. Due to the increasing prevalence of both clonal groups among clinical APEC isolates, their high virulence-gene content, and zoonotic potential, we suggest them as possible candidates for the development of a future vaccine against avian colibacillosis.  相似文献   
17.
An indirect enzyme linked immunosorbent assay (iELISA) for diagnosis of anaplasmosis using undiluted individual milk samples from dairy cows was developed. The recombinant 19 kDa major surface protein 5 (rMSP5) of Anaplasma marginale was used as antigen. A monoclonal antibody against bovine IgG1 conjugated with peroxidase and the chromogen 3,5,3',5'-tetramethylbenzidine were used in the test. Strong and weak, positive and negative milk samples were set up as reference controls. Results were expressed as percentage of positivity (PP) contrasting with the strongest positive control. The test was evaluated in two groups (G1 and G2) of lactating dairy cows from herds located in A. marginale non-endemic areas of Argentina. The infection status of both groups, G1 (n=128) sampled after anaplasmosis outbreak, and G2 (n=216) free of anaplasmosis was established by polymerase chain reaction (PCR). Serum samples of cows from G1 and G2 were analyzed by card agglutination test (CAT) and competitive ELISA (cELISA), while the novel iELISA was evaluated in their corresponding milk samples. At a cutoff of 42 PP, the ELISA has 98% sensitivity and 95% specificity. A significant difference (P<0.0001) was found between the mean PP value of negative samples from G1 (17.4+/-14.9), and G2 (8.6+/-7.1). The agreement and kappa (kappa) value between iELISA and PCR was 96%, kappa=0.919; between iELISA and CAT was 97%, kappa=0.880; and between iELISA and cELISA was 97%, kappa=0.899. These results strongly support the usefulness of iELISA to detect A. marginale antibodies in milk. Additional studies are necessary to define the ability of the milk iELISA to detect not only acutely infected, but also carrier cattle.  相似文献   
18.

Elicitation is a biotechnological approach to improve phenolic compounds content and antioxidant properties of ready-to-eat functional foods. This study aimed to evaluate the chemical elicitation effects using salicylic acid (SA) and hydrogen peroxide (H2O2) in optimized-germination conditions on seedling vigor, phenolic content, and their antioxidant capacities in vitro and serum and urine of Wistar obese rats. Optimized-germination conditions of 26.5 °C and 178 h produced a 64% of germination and a sprout length of 56 mm. Only, the elicitation with H2O2 (20 mM) enhanced the germination (75%) and H2O2 (10 and 20 mM) the sprout length (69 and 59 mm, respectively). In contrast, both elicitors enhanced phenolic contents, being more significant total phenolic compounds content for SA (1 and 2 mM), up to 65.5–73.5%. SA and H2O2 improved total flavonoids content (36.5–64.1%), ABTS (19.3–61.1%), and DPPH capacities (51–86%), depending on SA and H2O2 concentration, compared with non-elicited chia sprouts. The QUENCHER antioxidant capacities of elicited chia sprouts increased up to three times more than extracts capacities, principally Q-ABTS, which could be attributed to phenolic bounds to dietary fiber. Rats fed with a high-fat and fructose diet (HFFD) and supplemented with chia sprouts, especially 1-mM SA, improve the obesity-related oxidative stress through an increase of antioxidant capacities, using DPPH and ABTS test, on serum (70–118%) and urine samples (80–116%). These results suggest that chia sprouts elicited with 1-mM SA are a source of antioxidant compounds that can be used to decrease obesity related oxidative stress.

  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号