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   52篇
  免费   5篇
林业   3篇
农学   2篇
  11篇
综合类   4篇
农作物   11篇
水产渔业   11篇
畜牧兽医   10篇
植物保护   5篇
  2021年   2篇
  2020年   5篇
  2019年   5篇
  2018年   3篇
  2017年   9篇
  2016年   8篇
  2014年   2篇
  2013年   3篇
  2012年   4篇
  2011年   3篇
  2010年   4篇
  2009年   2篇
  2008年   4篇
  2007年   2篇
  2006年   1篇
排序方式: 共有57条查询结果,搜索用时 15 毫秒
51.
Two experiments were conducted to investigate the effects of oral supplementation of the lactic-acid-producing bacterium Enterococcus faecium EF212 alone or in combination with Saccharomyces cerevisiae (yeast) on mediators of the acute phase response in feedlot steers. Eight fistulated steers were used to study the effects of E. faecium alone or with yeast in a crossover design with 2 Latin squares, 4 steers within each square, and 2 periods. The length of each period was 3 wk, with a 10-d adaptation and an 11-d measurement period. The experimental diet contained 87% steam-rolled barley, 8% whole-crop barley silage, and 5% supplement (DM basis). In Exp. 1, treatments were control vs. the lactic-acid-producing bacterium E. faecium (6 x 10(10) cfu/d). In Exp. 2, treatments were control vs. E. faecium (6 x 10(10) cfu/d) and S. cerevisiae (6 x 10(10) cfu/d). The bacteria and yeast supplements were blended with calcium carbonate to supply 6 x 10(10) cfu/d when top-dressed into the diet once daily at the time of feeding (10 g/d). Steers fed the control diet received only carrier (10 g/d). Blood samples were collected from the jugular vein on d 17 and 21 of each period, and serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), haptoglobin, and alpha1-acid glycoprotein (alpha1-AGP) were measured. Supplementation of feed with E. faecium had no effect on concentrations of SAA, LBP, haptoglobin, or alpha1-AGP in plasma compared with those of controls. However, feeding E. faecium and yeast increased (P = 0.02) plasma concentrations of SAA, LBP, and haptoglobin but had no effect on plasma alpha1-AGP. In conclusion, oral supplementation of E. faecium alone had no effect on the mediators of the acute phase response that were measured, whereas feeding of E. faecium and yeast induced an inflammatory response in feedlot steers fed high-grain diets. Further research is warranted to determine the mechanism(s) by which E. faecium and yeast stimulated production of acute phase proteins in feedlot steers.  相似文献   
52.
The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3O4 composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe3O4 composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe3O4 and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe3O4 nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications.  相似文献   
53.
Spirogyra is commonly found as accessible algae in freshwater areas all over the world. Some medical uses have been reported from this genus. Biological activities of Spirogyra singularis were investigated employing eight in vitro assays. The extract showed different antioxidant activity. IC50 for DPPH radical-scavenging was 4.71 ± 0.11 μg mL?1. The extract showed very strong nitric oxide-scavenging activity with IC50 = 77.3 ± 2.07 μg mL?1, but its Fe2+ chelating ability was weak. The extract also exhibited high antioxidant activity in hemoglobin-induced linoleic acid peroxidation tests and scavenging of hydrogen peroxide. The extract also showed good antihemolytic activity. The total amount of phenolic content in the extract was determined as gallic acid equivalents, and total flavonoid content was calculated as quercetin equivalents. Biological activities may be attributed, at least in part, to the presence of phenol and flavonoid contents in the extract.  相似文献   
54.
The aim of this study was to compare the effect of a 40:2, 15:2 versus 30:2 Compression: Ventilation (C:V) ratio on rate of Chest Compression (CC), rescuer fatigue and satisfaction. We measured the BP and pulse. Fifty three persons performed BLS and CPR using C:V of 15:2, 30:2 and 40:2 on an adult resuscitation lardal manikin for 2 min. Two researchers measured the above mentioned variables. Data were analyzed by ANOVA, student's t-test or Mann-Whitney U test between groups. The value of p < 0.05 was considered as significant. The results revealed fatigue after 2 min and satisfaction from the performed technique in the groups differed (p< 0.05). Number of breathing in two minutes was 8.8 +/- 4.7(1-24). Total cardiac massage in 2 min. in the study groups was 131.7 +/- 40.6 (20-265), of this number in 130.6 +/- 40.5 was done correctly. The number of compression per 2 min increased with C:V ratio of 40:2 than to other C:V ratio. Most of participants (71.7%) prefer using 30:2 ratios to achieve the primary goal of Cardiopulmonary Resuscitation (CPR). The PR and systolic, diastolic BP of rescuers before and 2 min after resuscitation had insignificant difference (p < 0.001) and SBP differed between groups (p < 0.04). Although the rescuers prefer to perform the C:V ratio 30:2, but number of CC is less than standard recommended by AHA. Alternative C:V ratio of 40:2 methods, is equal to the AHA recommended 80 compressions/minute and also highest number of CC is done in 2 min, while, in the other methods is less than the recommended number.  相似文献   
55.
The comparative effects of Freund's and Aloe vera gel as adjuvants on the expression of IL‐1β and TNF‐α genes were studied in vaccinated common carp (Cyprinus carpio) with Aeromonas hydrophila bacterin. Fishes were intraperitoneally immunized with A. hydrophila bacterin in combination with Aloe vera gel or Freund's and also without any adjuvant. At day 28 after immunization, all groups were challenged by lethal dose of A. hydrophila (107 cells/fish). Changes in the expression of IL‐1β and TNF‐α genes were evaluated in anterior kidney before challenge and 12, 24, 72 and 7 days postchallenge using quantitative real‐time PCR. Higher expression levels of both genes were observed in all vaccinated groups compared with non‐immunized group. Fishes which received Aloe vera gel showed higher expression of IL‐1β and TNF‐α in relation to animals which vaccinated with or without Freund's adjuvant. We concluded that Aloe vera gel in compared with Freund's adjuvant had a more stimulatory effect on the expression of immune‐related genes in vaccinated common carp and it can use as a novel adjuvant in aquaculture.  相似文献   
56.
Today's customers are looking for non-fat or low-fat containing products. One of the methods to reduce oil absorption in fried products is partial drying before frying. In this study, influence of partial drying (10 min, 20 min, 30 min) on oil absorption and quality attributes of three potato cultivars (Agria, Satina, kenebek) was evaluated. Our results reveled that in Agria, partial drying leads to an increase in oil absorption compared with non-dried sample (p〈0.05). In kenebek, partial drying reduced the oil absorption and improved the texture and color of the produced French fries (p〈0.05). Similar results were observed with Satina as with kenebek. In all three varieties, partial drying increased the dry matter, color quality and required cutting force of the French fries (p〈0.05).  相似文献   
57.
Freezing injury is one of the most restrictive dynamics issues that commercial fig producers are fronting. This study was aimed to compare cold hardiness among seven commercial fig cultivars at three different developmental stages. We investigated the association between freezing tolerance and soluble carbohydrate and proline fluctuations during acclimation in the one-year-old fig shoots. Using both electrolyte leakage measurement and tetrazolium stain test LT50 values were calculated, which differentiate freezing tolerance among the studied cultivars. The results showed significant differences among the cultivars at three evaluation stages of dormancy. The average of cold winter resistance in studied cultivars in November, January, and March, were ?16.89, ?20.23, and ?21.35?°C, respectively. LT50 electrolyte leakage, cold hardiness index, significantly varied among the fig cultivars. In November to January, ‘Atabaki’ and ‘Kashki’ cultivars showed the maximum of ?0.11?°C/per day, and the minimum of ?0.01?°C/per day of adaptation rate, respectively. Soluble carbohydrate (sugars) concentrations of shoot samples increased during cold acclimation from November (49?mg/g dry weight (DW)) to January (130?mg/g DW) and then decreased in March (93?mg/g DW). Proline content varied significantly among the cultivars in November and January. High correlations were observed between LT50 values and the soluble carbohydrates content compared with proline. Soluble sugars content might be a better indication of cold hardiness than proline content in fig trees. ‘Atabaki’ cultivar showed a very good resistance to winter freezing in comparison to others cultivars, although it seems to be very sensitive to fall freezing. The outcome of this study can be considered for sustainable production and breeding programs in common figs.  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