全文获取类型
收费全文 | 199292篇 |
免费 | 11128篇 |
国内免费 | 120篇 |
专业分类
林业 | 7482篇 |
农学 | 6092篇 |
基础科学 | 1331篇 |
23052篇 | |
综合类 | 36864篇 |
农作物 | 7700篇 |
水产渔业 | 9905篇 |
畜牧兽医 | 101826篇 |
园艺 | 2551篇 |
植物保护 | 13737篇 |
出版年
2018年 | 2465篇 |
2017年 | 2768篇 |
2016年 | 2632篇 |
2015年 | 2272篇 |
2014年 | 2802篇 |
2013年 | 7581篇 |
2012年 | 5319篇 |
2011年 | 6555篇 |
2010年 | 4182篇 |
2009年 | 4135篇 |
2008年 | 6345篇 |
2007年 | 6147篇 |
2006年 | 5889篇 |
2005年 | 5490篇 |
2004年 | 5321篇 |
2003年 | 5340篇 |
2002年 | 5173篇 |
2001年 | 6238篇 |
2000年 | 6019篇 |
1999年 | 4877篇 |
1998年 | 2047篇 |
1997年 | 2001篇 |
1996年 | 1874篇 |
1995年 | 2281篇 |
1994年 | 2081篇 |
1993年 | 2044篇 |
1992年 | 4142篇 |
1991年 | 4319篇 |
1990年 | 4286篇 |
1989年 | 4353篇 |
1988年 | 3957篇 |
1987年 | 4109篇 |
1986年 | 4244篇 |
1985年 | 4036篇 |
1984年 | 3391篇 |
1983年 | 3046篇 |
1982年 | 2145篇 |
1981年 | 1958篇 |
1980年 | 1856篇 |
1979年 | 2997篇 |
1978年 | 2495篇 |
1977年 | 2137篇 |
1976年 | 1937篇 |
1975年 | 2045篇 |
1974年 | 2658篇 |
1973年 | 2730篇 |
1972年 | 2682篇 |
1971年 | 2433篇 |
1970年 | 2303篇 |
1969年 | 2108篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
M M Otremba M E Dikeman G A Milliken S L Stroda J A Unruh E Chambers 《Journal of animal science》1999,77(4):865-873
993.
C J Henry M S Buss K A Potter K J Wardrop 《Journal of the American Animal Hospital Association》1999,35(3):236-239
Thirteen dogs with histopathologically confirmed malignancies were treated with mitoxantrone and cyclophosphamide combination therapy. One to four doses were administered at 21-day intervals. Recombinant human granulocyte colony-stimulating factor was administered to ameliorate myelosuppression in dogs with neutrophil nadirs less than 1,000/microl. While the protocol appears to be safe for use in tumor-bearing dogs, an advantage over mitoxantrone single-agent protocols in terms of tumor response was not demonstrated in this initial pilot study. 相似文献
994.
K Konno J A Abella Y Oku N Nonaka M Kamiya 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1999,61(4):317-324
Rats heavily infected with larval Taenia taeniaeformis show hyperplasia of the gastric mucosa accompanied by mucous cell proliferation, increase in the level of intragastric pH and hypergastrinemia. Sixty one rats were divided into 2 groups designed as infected (36 rats) and control (25 rats) group. These rats were examined with time course of the infection histopathologically and physiopathologically, during 14-112 days postinfection (DPI). In the infected rats, gastric mucosal hyperplasia began to be observed at 56 DPI, and the structural disturbance of zymogenic units in the corpus and mucous units in the antrum had increased with time. However, the degree of these changes in the antrum was weaker than those in the corpus. Alcianblue and/or PAS-positive cells increased in their numbers with time, and 4 types of cells other than typical surface mucous cell and mucous neck cell were observed by electron-microscopy. However, zymogenic and parietal cells decreased in their number after 56 DPI. Further, the infected rats showed changes in the serum concentration of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, glucose and total protein. Some similarities with Menetrier's disease were discussed. 相似文献
995.
996.
997.
Horses with tears that involve all layers of the rectum except the mesocolon (grade IIIb) have a poor prognosis for survival because of the difficulty in treating these wounds and the propensity for them to progress to full perforations (grade IV). Most treatments for grade-IIIb rectal tears involve surgery of some kind, but not all grade-IIIb rectal tears require surgical intervention. We report on 4 horses with grade-IIIb rectal tears that were evaluated via palpation per rectum and endoscopy. Two of 4 horses were admitted with signs consistent with shock and endotoxemia, and evaluation of all peritoneal fluid samples was indicative of nonseptic peritonitis. Horses were treated via administration of antibiotics and anti-inflammatory drugs and repeated manual evacuation of the terminal portion of the small colon and rectum. Treatment centered on preventing further enlargement of the rectal tear by eliminating the storage function of the terminal portion of the small colon and rectum. None of our horses had worsening of the original injury, and horses were discharged within 2 weeks of admission with full resolution of the rectal tear. Outcomes in the horses of our report indicate that repeated manual evacuation can be successful for treatment of horses with grade-IIIb rectal tears. 相似文献
998.
W. Lilenbaum J. C. Schettini G. N. Souza E. R. Ribeiro E. C. Moreira L. S. Fonseca 《Zoonoses and public health》1999,46(5):353-358
Bovine tuberculosis is a major problem in Brazil. The intradermal tuberculin test is the standard test for detection of bovine tuberculosis in Brazil but can lack both sensitivity and specificity. The purpose of this study was to compare a bovine γ-IFN assay with the tuberculin test under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested using the single cervical tuberculin test (SCTT). Among those animals, about 15% of each herd, 220 in total, represented a high-risk group and were selected to be tested using the γ-IFN test. Of the 1632 animals tested, 207 presented significant reactions representing 12.7% of the cattle studied. In the selected group the number of animals positive by the γ-IFN assay was 126/220 (57.3%) and the total number of reactive cows on SCTT was 106/220 (48.2%). The real number of infected cattle, following standards, was 120/220 (54.5%). From these results the relative sensitivity rate of γ-IFN test was 100% including the false-positive results and 88.3% for the SCTT — a significant (P < 0.01) difference in favour of the γ-IFN test of 11.7%. The γ-IFN assay also identified some positive animals 60–120 days earlier than the SCTT. In conclusion, we believe that the γ-IFN assay can be used alone or in combination with the SCTT, as a valuable tool for the control of bovine tuberculosis in the Brazilian national herd. 相似文献
999.