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   27篇
  免费   0篇
农学   1篇
基础科学   2篇
综合类   13篇
畜牧兽医   9篇
园艺   1篇
植物保护   1篇
  2024年   1篇
  2019年   1篇
  2014年   1篇
  2012年   1篇
  2011年   1篇
  2010年   3篇
  2009年   4篇
  2008年   2篇
  2007年   1篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   1篇
  1999年   1篇
  1998年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1981年   1篇
排序方式: 共有27条查询结果,搜索用时 31 毫秒
1.
2.
Gaining a detailed knowledge on the impact of a feedstuff on pig growth and physiological responses is critical for its effective utilization. Thus, the purpose of this study was to investigate the effect of distillers dried grains with solubles derived from co‐fermentation of wheat and corn (wcDDGS) on performance, carcass and visceral organ weights, whole‐body O2 consumption and heat production (HP) in growing barrows. The experimental diets were as follows: corn–soybean meal diet (Control), Control + 15% wcDDGS and Control + 30% wcDDGS. In Exp. 1, 48 pair‐housed pigs of average BW 18.6 ± 1.5 kg (mean ± SD) were allotted to the 3 diets (n = 8). Pigs had free access to water and feed for a 28‐day period during which ADG and ADFI were calculated weekly. Thereafter, 1 pig/pen was killed to measure carcass and visceral organ weights. Overall, wcDDGS linearly decreased (p < 0.05) ADFI and ADG but had no effect on G:F (p > 0.10). The ADFI was 1.55, 1.45 and 1.36 kg/day for diets containing 0, 15 and 30% wcDDGS respectively; corresponding values for ADG were 0.79, 0.75 and 0.67 kg/day respectively. A linear decline (p = 0.01) in eviscerated hot carcass weight was observed as dietary wcDDGS increased. In Exp. 2, 18 pigs of average BW 20.4 ± 2.4 kg (mean ± SD) were individually housed in metabolism crates and fed the 3 diets (n = 6) at 550 kcal ME kg BW?0.60day for a 16‐day period followed by measurement of O2 consumption using an indirect calorimeter. Diet had no effect (p > 0.10) on whole‐body O2 consumption and HP. In conclusion, increasing wcDDGS content in growing pig diets linearly reduced ADFI, ADG and eviscerated hot carcass weight but had no effect on G:F, visceral organ weights or HP.  相似文献   
3.
Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds.  相似文献   
4.
As a first step toward understanding how rare variants contribute to risk for complex diseases, we sequenced 15,585 human protein-coding genes to an average median depth of 111× in 2440 individuals of European (n = 1351) and African (n = 1088) ancestry. We identified over 500,000 single-nucleotide variants (SNVs), the majority of which were rare (86% with a minor allele frequency less than 0.5%), previously unknown (82%), and population-specific (82%). On average, 2.3% of the 13,595 SNVs each person carried were predicted to affect protein function of ~313 genes per genome, and ~95.7% of SNVs predicted to be functionally important were rare. This excess of rare functional variants is due to the combined effects of explosive, recent accelerated population growth and weak purifying selection. Furthermore, we show that large sample sizes will be required to associate rare variants with complex traits.  相似文献   
5.
AIM: Our purpose was to induce MSCs differentiating into endothelial cells (EC) in vitro and to provide the seed cells for study of cardiovascular tissue-engineering. METHODS: MSCs were separated by gradient centrifugation on Percoll (density 1 073 g/L) from human bone marrow (HBM), and incubated for purification and amplification in DMEM (low glucose) with 10% fetal bovine serum (FBS). Then, the MSCs were incubated for orientation differentiated into EC in DMEM (high glucose) with 20% FBS, VEGF (10 μg/L), bFGF (5 μg/L), L-glutamine (2 mmol/L), penicillin (1×105U/L) and streptomycin (100 mg/L) for about 14-21 days and their phenotypic characteristics were analyzed by flow cytometry. Afterwards, the differentiating cells were evaluated by histology and immunohistochemistry. RESULTS: The quantity of MSCs was increased from 5.0×105 in the primary culture to 8.0×1012, or to increase to 1.6×107 times after 15 generations of incubation. The purity of MSCs was above 95% and 98% homogeneous at passages 2 and 3, respectively. About 80%-90% of the differentiating cells from MSCs after 14-21 days were positively stained for Ⅷ factor (vWF) related antigen by immunohistochemistry assay, and Weible-palade corpuscle was also observed by transmission electron microscopy in the cytoplasm. CONCLUSION: MSCs from HBM have the capability of differentiation into ECs in vitro, which may be a potential source of seed cells for fabrication of tissue-engineering heart valve, particularly in children with congenital heart disease.  相似文献   
6.
加工类型黄瓜品质性状的主成分及聚类分析   总被引:6,自引:0,他引:6  
对19个加工类型黄瓜品种的7个品质性状进行了主成分和聚类分析.结果表明19个品种分为产量、形态和品质3个主成分因子,其主成分的累计贡献率达89.81%,而且基本上可描述7个品质性状的遗传变异.当类平均距离为1.035时,19个品种被聚为短果和长果2种类型,而当类平均距离为0.942时,19个品种被聚为短果中等品质、短果优质和长果高产3种类型.  相似文献   
7.
8.
The Anopheles gambiae genome sequence will accelerate identification of new insect vector target genes leading to improved strategies for malaria control.  相似文献   
9.
东北三省番茄叶霉病生理小种分化的初步研究   总被引:7,自引:4,他引:7  
采用国际通用番茄叶霉病鉴别寄主谱,利用苗期人工喷雾接种方法,参照国外N·Hubbeling氏叶霉病生理小种分化表(1971),仿照P.Day分类方法,对东北三省郊区大棚番茄叶霉病进行鉴定.结果表明.东北三省郊区大棚番茄叶霉病生理小种为小种1,2,3;小种1,3和小种3;而以小种1,2,3为主.  相似文献   
10.
Diarrhoeic faecal samples from 210 humans and 192 swine were screened for Yersinia enterocolitica in 1990. Ten and 8 Y. enterocolitica strains were isolated from pig and man, respectively. The isolates were found to belong to Wauter's biotypes 1, 2, 3 and 4. Biotype 2 was isolated mainly from human stool samples. Biotype 3 was found only in swine while biotypes 1 and 4 were isolated from both man and swine. All the 18 strains showed varying degrees of sensitivity to antibiotics used in this investigation. The organisms were consistent in their resistance to ampicillin and penicillin.  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