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   269篇
  免费   14篇
林业   23篇
农学   5篇
  13篇
综合类   34篇
农作物   4篇
水产渔业   8篇
畜牧兽医   174篇
园艺   4篇
植物保护   18篇
  2021年   2篇
  2020年   10篇
  2019年   4篇
  2018年   5篇
  2017年   6篇
  2016年   5篇
  2014年   8篇
  2013年   17篇
  2012年   8篇
  2011年   6篇
  2010年   9篇
  2009年   4篇
  2008年   9篇
  2007年   6篇
  2006年   5篇
  2005年   8篇
  2004年   13篇
  2003年   8篇
  2002年   14篇
  2001年   6篇
  2000年   7篇
  1999年   10篇
  1998年   2篇
  1996年   4篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1992年   7篇
  1991年   3篇
  1989年   3篇
  1988年   6篇
  1987年   4篇
  1985年   3篇
  1984年   2篇
  1983年   3篇
  1979年   5篇
  1977年   2篇
  1976年   3篇
  1974年   6篇
  1973年   4篇
  1972年   5篇
  1971年   7篇
  1970年   7篇
  1969年   9篇
  1967年   2篇
  1945年   1篇
  1934年   1篇
  1933年   1篇
  1932年   1篇
  1926年   1篇
排序方式: 共有283条查询结果,搜索用时 78 毫秒
221.
222.
223.
224.
A randomised double-blind parallel study compared the clinical and antimicrobial efficacies of a miconazole-chlorhexidine shampoo with a selenium sulphide shampoo for the treatment of seborrhoeic dermatitis associated with Malassezia pachydermatis in 33 basset hounds. All 16 miconazole-chlorhexidine treated hounds and 11 of 17 selenium sulphide treated hounds improved when shampooed at three-day intervals for three weeks. The miconazole-chlorhexidine treated hounds showed significantly greater reductions in pruritus (P<0·01), erythema (P<0·001), exudation (P<0·01) and overall severity (P<0·001), and in counts of M pachydermatis (P<0·001), total bacteria (P<0·001) and coagulase-positive staphylococci (P<0·001), when compared to the selenium sulphide treated group. Improvements in scaling and coat condition did not vary significantly between the two groups. These results indicate that seborrhoeic dermatitis in basset hounds is often associated with elevated  相似文献   
225.
A questionnaire was sent to veterinary surgeons who had diagnosed exocrine pancreatic insufficiency (EPI) by assay of low serum concentration of trypsin-like immunoreactivity in 302 dogs. Two-thirds of cases were German shepherd dogs, in which EPI was found equally in males and females. The disease was also diagnosed in 33 other breeds, most commonly in crossbreeds, spaniels, small terriers and collies, and was more common in females. Detailed replies on 160 cases were returned; 79 dogs were alive and 41 dead, with the remainder lost to long term follow-up. The major reasons for death were euthanasia because of the cost, the prognosis, and failure to respond to treatment. An adequate response to treatment was obtained in 92 per cent of dogs. Uncoated preparations of pancreatic enzyme replacement were found to be more successful, and the use of dietary manipulation and antibiotics were frequently reported to be useful adjunctive therapies.  相似文献   
226.
227.

Background

Recently, a Risk Assessment methodology was applied to animal welfare issues in a report of the European Food Safety Authority (EFSA) on intensively housed calves.

Methods

Because this is a new and potentially influential approach to derive conclusions on animal welfare issues, a so-called semantic-modelling type ''validation'' study was conducted by asking expert scientists, who had been involved or quoted in the report, to give welfare scores for housing systems and for welfare hazards.

Results

Kendall''s coefficient of concordance among experts (n = 24) was highly significant (P < 0.001), but low (0.29 and 0.18 for housing systems and hazards respectively). Overall correlations with EFSA scores were significant only for experts with a veterinary or mixed (veterinary and applied ethological) background. Significant differences in welfare scores were found between housing systems, between hazards, and between experts with different backgrounds. For example, veterinarians gave higher overall welfare scores for housing systems than ethologists did, probably reflecting a difference in their perception of animal welfare.Systems with the lowest scores were veal calves kept individually in so-called "baby boxes" (veal crates) or in small groups, and feedlots. A suckler herd on pasture was rated as the best for calf welfare. The main hazards were related to underfeeding, inadequate colostrum intake, poor stockperson education, insufficient space, inadequate roughage, iron deficiency, inadequate ventilation, poor floor conditions and no bedding. Points for improvement of the Risk Assessment applied to animal welfare include linking information, reporting uncertainty and transparency about underlying values.

Conclusion

The study provides novel information on expert opinion in relation to calf welfare and shows that Risk Assessment applied to animal welfare can benefit from a semantic modelling approach.  相似文献   
228.
The effect of co‐culture of buffalo preantral follicles (PFs) with different somatic cells, i.e, cumulus, granulosa, ovarian mesenchymal and oviductal epithelial cells was studied. Large PFs (250–450 μm) were isolated by microdissecting the trypsin (1%) digested ovarian cortical slices. Cumulus cells were isolated by repeated pipetting of oocytes, granulosa cells were isolated by aspirating from punctured PFs and ovarian mesenchymal cells were isolated from ovarian cortex by scraping the cortical slices and passing through 20 μm filter. Preantral follicles were cultured in standard culture medium without somatic cells or co‐cultured with cumulus cells, granulosa cells, ovarian mesenchymal cells and oviductal epithelial cells for 80 days. The growth rate (μm/day) of the PFs was monitored by measuring follicular diameter on day 0, 30, 60 and 80 days of culture. The viability of PFs was evaluated by trypan blue staining. The results indicated that PFs co‐cultured with cumulus, granulosa and ovarian mesenchymal cells had a better development and survivality compared with control and those co‐culture with oviductal epithelial cells. Maximum growth and survivality of PFs were achieved when cultured with cumulus cells. It is concluded that inclusion of somatic cells in PF culture media had beneficial effect on the growth of PFs and cumulus cells supported maximum growth and survivality of PFs in vitro of all somatic cells tested.  相似文献   
229.
230.
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