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   423篇
  免费   27篇
林业   10篇
农学   6篇
  41篇
综合类   38篇
农作物   28篇
水产渔业   28篇
畜牧兽医   264篇
园艺   1篇
植物保护   34篇
  2020年   6篇
  2019年   4篇
  2018年   7篇
  2017年   8篇
  2016年   16篇
  2015年   4篇
  2014年   7篇
  2013年   17篇
  2012年   4篇
  2011年   4篇
  2010年   18篇
  2009年   10篇
  2008年   8篇
  2006年   10篇
  2005年   6篇
  2004年   5篇
  1999年   12篇
  1998年   17篇
  1997年   17篇
  1996年   16篇
  1995年   16篇
  1994年   4篇
  1993年   15篇
  1992年   11篇
  1991年   6篇
  1990年   11篇
  1989年   10篇
  1988年   12篇
  1987年   7篇
  1986年   10篇
  1985年   6篇
  1983年   8篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1979年   8篇
  1977年   4篇
  1971年   6篇
  1970年   3篇
  1968年   3篇
  1965年   3篇
  1963年   6篇
  1961年   3篇
  1960年   3篇
  1958年   10篇
  1957年   6篇
  1956年   9篇
  1955年   4篇
  1954年   6篇
  1953年   6篇
排序方式: 共有450条查询结果,搜索用时 15 毫秒
61.
62.
CASE HISTORY: A 14-year-old neutered male Bearded Collie was presented with a history of recurrent, intermittent urinary incontinence of 7 years duration.

CLINICAL FINDINGS: A large, firm, non-painful mass was found in the mid-abdominal region on palpation. Ultrasonography of the mass revealed a compartmentalised structure with mixed echogenicity, and which did not appear to be associated with any of the abdominal organs. Ultrasound-guided fine needle aspirates contained several clusters of epithelial cells with cytological features of hepatocytes. At exploratory laparotomy, the mass was found in the gastrosplenic ligament within the greater omentum.

PATHOLOGICAL FINDINGS AND DIAGNOSIS: Histopathologically, the mass consisted of sheets of hepatocytes, but without the characteristic hepatic architecture. The cells showed moderate variation in nuclear size and were sometimes binucle- ate. A diagnosis of hepatocellular carcinoma (HCC) in the mesentery was made.

CLINICAL RELEVANCE: The presence of ectopic hepatic tissue has been reported rarely in man and cats, but not in the dog. Neoplastic transformation of ectopic hepatic tissue is seen in man. This is the first report of the presentation, clinical findings and treatment of a dog with ectopic HCC.  相似文献   
63.
64.
65.
Surgical resection of a dysgerminoma in a mare   总被引:1,自引:1,他引:0  
A mare was referred for further evaluation of a mass found in the left caudal abdomen during a routine postpartum reproductive palpation. The mare was clinically normal with no history of health problems. Ultrasonographic examination of the mass confirmed its presence, but the origin of the mass could not be accurately determined. Routine haematology and serum biochemistry results were within normal limits. The mare was initially treated conservatively with antibiotics, but the mass continued to increase in size, so it was surgically excised. The mass involved the left ovary. The mare showed transient abdominal pain after surgery, but developed no other complications and was in foal 7 months later. On histology, the mass was diagnosed as a dysgerminoma, a rare ovarian tumour of germ cell origin.  相似文献   
66.
A series of abortions occurred in mares in New South Wales during 2004 that involved similar and unusual findings on post mortem examination of aborted fetuses and fetal membranes. The term Equine Amnionitis and Fetal Loss (EAFL) was developed to describe the condition. This form of abortion had not been previously recognised in Australia. The pathology alone is not specific for EAFL and diagnosis requires demonstration of a combination of certain pathological and bacteriological features. The purpose of this paper is to describe patterns considered consistent with EAFL cases as a working case definition for use by veterinarians and veterinary pathologists in identifying future cases of EAFL. More detailed papers are in preparation to fully describe the epidemiological, histopathological, and microbiological aspects of EAFL.  相似文献   
67.
Abstract Retaining coral reef fish for subsistence during commercial fishing is a common practice for indigenous fishers in the Torres Strait, Australia, despite being inconsistent with legislation. Fisher access point surveys were completed between 2004 and 2006 on three islands in Torres Strait to characterise this subsistence practice and assess the level to which it undermines current minimum legal fish sizes. Approximately 15% of the annual total catch was retained for subsistence during commercial fishing. Notably, subsistence catch of the most commercially valuable species almost entirely comprised individuals smaller than the minimum legal sizes. The higher proportions of undersized individuals of valuable species retained during commercial fishing on some of the islands were most likely associated with an increase in professionalism of the fishers. These results demonstrate how the intended outcomes from a management strategy can be undermined when the specific operational conditions of the fishery are not considered. Successful implementation of management arrangements in indigenous communities ultimately depends on the sociocultural conditions of the communities and their understanding and adherence to the rules. A productive way forward for the management of this fishery is greater engagement of indigenous communities and managers in co‐management arrangements.  相似文献   
68.
69.
70.
The aim of this study was to determine which cells are the source of production and target for leukotriene (LTs) action within the bovine ovary. Luteal (CL, days 14–16 of the oestrous cycle), steroidogenic cells (LSC) and endothelial cells (LEC) of the bovine corpus luteum (CL), and granulosa cells (GC) were isolated enzymatically, cultured in a monolayer and incubated with LTC4, LTB4, Azelastine (an antagonist of LTC4) or Dapsone (an antagonist of LTB4). Then cells were collected for determination of mRNA expression for LT receptors (LTRs) and 5‐lipoxygenase (5‐LO) by real time RT‐PCR, and media were collected for determination of prostaglandin (PG)E2, F, progesterone (P4; LSC only), endothelin‐1 (ET‐1; LEC only) and 17‐β oestradiol (E2; GC only). The greatest mRNA expression for LTR‐II and 5‐LO were found in LEC, whereas LTR‐I mRNA expression did not differ among cell types. The level of PGE2 increased after LTs treatment in each type of ovarian cell, excluding LTC4 treatment in LEC. The secretion of PGF was also increased by LTs, but decreased after LTB4 treatment of LSC. In GC cultures, both LTs stimulated E2 secretion; in LEC cultures, LTB4 stimulated whereas LTC4 inhibited P4 secretion; in LEC cultures, LTC4 stimulated but LTB4 inhibited ET‐1 secretion. The results show that LTs are produced locally and are involved in PGs production/secretion in all examined cells (LSC, LEC and GC) of bovine ovary. Leukotriene treatment modulate secretion of E2, by GC, P4 by LSC and ET‐1 by LEC, which indicates that LTs are involved in regulation of ovarian secretory functions.  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