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   139篇
  免费   4篇
林业   17篇
农学   16篇
  10篇
综合类   1篇
农作物   2篇
水产渔业   15篇
畜牧兽医   61篇
园艺   2篇
植物保护   19篇
  2021年   2篇
  2020年   3篇
  2019年   2篇
  2018年   3篇
  2016年   5篇
  2015年   4篇
  2014年   6篇
  2013年   5篇
  2012年   4篇
  2011年   6篇
  2010年   6篇
  2009年   5篇
  2008年   7篇
  2007年   9篇
  2006年   12篇
  2005年   8篇
  2004年   10篇
  2003年   6篇
  2002年   3篇
  2001年   8篇
  2000年   3篇
  1999年   4篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1992年   1篇
  1990年   1篇
  1989年   4篇
  1984年   2篇
  1981年   1篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
排序方式: 共有143条查询结果,搜索用时 0 毫秒
141.
In this study, we attempted to produce piglets by non-surgically transferring blastocysts produced in vitro, using a flexible catheter as the transfer instrument. Cumulus-oocyte complexes (COCs) were aspirated from the follicles of ovaries obtained at a local slaughterhouse. They were then matured in modified North Carolina State University (NCSU)-37 medium for 44-46 h and fertilized in porcine gamete medium (PGM). Ten hours after in vitro fertilization (IVF), presumptive zygotes were removed from the cumulus cells and cultured in porcine zygote medium (PZM)-5. Blastocysts were cultured for five days after IVF and, using a catheter for deep intrauterine insemination without sedation, they were transcervically transferred into the uterine horn of six recipients (45-50 blastocysts/recipients) whose estrous cycles were synchronized, at 5 days after human chorionic gonadotropin (hCG) injection. Of the six recipients, one sow became pregnant and farrowed seven piglets (four live piglets) 119 days after hCG injection. The body weight at birth of the newborns ranged from 0.8 to 1.4 kg. These results indicate that it is possible to obtain piglets by transcervically transferring blastocysts produced by IVF and in vitro cultures in chemically defined media.  相似文献   
142.
We examined the regulation of haptoglobin (Hp) secretion in primary cultured bovine hepatocytes using recombinant bovine (rb) proinflammatory cytokines. The concentrations of Hp in the supernatant of cultured hepatocytes after incubation with rb interleukin (IL)-6, rb tumor necrosis factor (TNF)-alpha, rbIL-1 beta or rbIFN-gamma alone or with combinations of two of these cytokines were measured by ELISA. The rbIL-6, rbTNF-alpha and rbIL-1 beta increased Hp synthesis, but rbIFN-gamma did not, and rbIL-6 was the most effective Hp inducer among these cytokines. The Hp secretion was accelerated synergistically by combined treatment with rbIL-6 and rbTNF-alpha, whereas it remained unchanged with a combination of rbIL-6 and rbIL-1 beta. In contrast, the combination of rbIL-6 and rbIFN-gamma downregulated Hp secretion. In conclusion, IL-6 is the principal cytokine in Hp secretion in bovine hepatocytes in vitro, and its activity may be regulated by other cytokines.  相似文献   
143.
Summary

Japanese pear ‘Kosui’ fruits were stored under a continuous flow of 0%, 1%, 3%, 5% and 10% O2 (balance N2) or air for 7 d at 20°C to study the effects of low O2 on their physiological responses and quality attributes. Low O2 treatments did not significantly influence changes in skin colour and soluble solids content. However, weak off-flavours were detected in the fruits stored at 0% O2 on day 3, and the intensity of these off-flavours increased as storage progressed. The concentrations of acetaldehyde in fruit increased throughout the storage period. The ethanol concentration was greatly increased in fruits stored at 0% O2. Moreover, ethanol concentrations were much higher than those of acetaldehyde and remained very low during storage in air, but their concentration were just slightly increased in fruits exposed to 1%, 3%, 5% and 10% O2. Pyruvate decarboxylase activity was greatly increased in fruits exposed to 1% and 3% O2, while its activity in fruits exposed to 5% and 10% O2 were only slightly higher than that of the control and at 0% O2 at the same level as the control. Alcohol dehydrogenase (ADH) activity greatly increased in fruit exposed to 0%, 1%, 3% and 5% O2, while at 10% O2, ADH was only slightly higher than the control. Changes in ADH isozymes correlated well with changes in ADH activity. The homogenate pH of fruits exposed to 1%, 3%, 5% and 10% O2 and air remained constant, while in fruit stored at 0% O2 their pH increased. The potential for using low O2 atmospheres to help in maintaining the quality of Japanese pear ‘Kosui’ is discussed.  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