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   371篇
  免费   35篇
  国内免费   6篇
林业   4篇
农学   2篇
综合类   35篇
农作物   5篇
水产渔业   18篇
畜牧兽医   333篇
园艺   12篇
植物保护   3篇
  2023年   11篇
  2022年   11篇
  2021年   18篇
  2020年   15篇
  2019年   24篇
  2018年   19篇
  2017年   10篇
  2016年   14篇
  2015年   15篇
  2014年   16篇
  2013年   25篇
  2012年   23篇
  2011年   24篇
  2010年   11篇
  2009年   15篇
  2008年   16篇
  2007年   22篇
  2006年   7篇
  2005年   14篇
  2004年   12篇
  2003年   9篇
  2002年   5篇
  2001年   9篇
  2000年   12篇
  1999年   5篇
  1998年   8篇
  1997年   6篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1993年   5篇
  1992年   3篇
  1991年   1篇
  1990年   3篇
  1989年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1978年   3篇
  1977年   1篇
排序方式: 共有412条查询结果,搜索用时 46 毫秒
91.
A 10‐month‐old German Shepherd Dog presented for evaluation of intermittent vomiting. Abdominal radiographs revealed a marked right cranial mass effect. Initial differentials included abscess/cyst or less likely neoplasia from undetermined origin. On abdominal ultrasound the mass appeared cystic and thin walled. Computed tomography revealed a large cystic lesion originating from the pyloroduodenal junction causing pyloric outflow obstruction. A noncommunicating duodenal duplication cyst was found on exploratory laparotomy and further confirmed with histopathology and immunohistochemistry. Enteric duplication cyst should be considered as a differential in young dogs with gastrointestinal signs and a cystic abdominal mass detected with different imaging modalities.  相似文献   
92.
A viral isolate from Egypt associated with symptoms of enations and leaf curling on hollyhock (Althea rosea) was characterized at the cytopathological and molecular levels. Microscopic observations showed that enations resulted from a reorganization of the vascular tissues, including activation of a cambial activity in the phloem, the development of a palisade parenchyma in place of a spongy one and the differentiation of minor vascular tissues. From this isolate, the full-length DNA-A of a begomovirus (family Geminiviridae) was cloned and sequenced. This genome exhibited a genetic organization similar to that of other old-world begomoviruses like Tomato yellow leaf curl virus from Israel and Ageratum yellow vein virus from Singapore. However, its sequence was significantly distinct (similarity < 69%) from any other geminivirus. This begomovirus was thus considered as representative of a new viral species named Althea rosea enation virus (AREV). AREV was agroinfectious on Nicotiana benthamiana, on which it induced a severe leaf-curling and vein distortion, but could not re-establish infection on A. rosea. To determine if AREV was also associated with a similar disease affecting okra in Upper-Egypt, the partial sequence of the coat protein gene of an isolate was determined. It exhibited 90% nt identity with the hollyhock isolate (97% amino acid), suggesting a genetic heterogeneity in the begomovirus population associated with the enation diseases.  相似文献   
93.
A 2‐day‐old Warmblood filly was presented for examination of an angular limb deformity of the left front limb and an upright conformation of both metacarpophalangeal joints. Radiological examination revealed bilateral absence of the metacarpophalangeal joint space with fusion of the third metacarpal bone and first phalanx (synostosis). No treatment was undertaken. The filly was readmitted to the clinic 10 weeks later for bilateral front limb lameness. On radiological examination, the synostosis of the front metacarpophalangeal joints was still present. Physitis of the distal growth plate of the right third metacarpal bone and proximal growth plate of the right proximal phalanx, and an avulsion fracture of the palmaromedial and proximal aspect of the left middle phalanx, with a cystic like lesion on the medial aspect of distal first phalanx and proximal middle phalanx were diagnosed. Given the poor prognosis, the foal was subjected to euthanasia. Post mortem examination confirmed the absence of the metacarpophalangeal joint space with a trabecular bony union between the third metacarpal bone and the first phalanx. A rudimentary joint capsule was present at the level of the absent joints as well as a small zone of articular cartilage, which invaginated over a short distance into the dorsal trabecular bone on the right front limb. On the medial aspect of the left proximal interphalangeal joint, a focal defect of articular cartilage with exposure of subchondral bone was observed. This is the first case report of a foal born with congenital aplasia of both metacarpophalangeal joints. Congenital malformations should be considered as differential diagnosis in lame foals or foals born with angular or flexural limb deformities.  相似文献   
94.
95.
96.
A 2‐year‐old American Pit Bull dog was presented for surgical evaluation of imperforate cor triatriatum dexter (CTD) and patent foramen ovale (PFO). Echocardiography identified an imperforate CTD associated with a right‐to‐left shunting PFO and valvular pulmonary stenosis. A 2‐step interventional and surgical approach was used. Initially, a pulmonary balloon valvuloplasty was performed, and subsequently the dog underwent a surgical correction of the atrial anomaly under cardiopulmonary bypass.  相似文献   
97.
Studies about prevalence of uterine pathologies in bitches are scarce. Although correlation between age and uterine disorders was documented, the most suitable age for a preventive sonographic screening has not been proposed yet. Present study aimed to estimate the eligible age for an ultrasonographic screening of uterine abnormalities in dogs. Data regarding ultrasound examination and clinical records of non‐pregnant intact females were retrospectively analysed. The age of each bitch was expressed as age ratio (actual/maximum age expected for the respective breed). The cut‐off age ratio was determined by a ROC curve for overall uterine abnormalities. Frequencies of different abnormalities below and over the cut‐off derived from the ROC curve were calculated and statistically analysed by chi‐Square and OR. Prevalence of three categories of ultrasonographic findings was as follows: cystic endometrial hyperplasia (CEH) 18%; uterine collections (UC) 10.5%; masses (M) 1.3%. By the cut‐off age ratio (0.325), derived by ROC curve (AUC = 0.91; SP 84.23%; SE 79.2%; PPV 83.4%; NPV 80%), 228 cases were divided into two subgroups: bitches over (exposed group: n.83) and below cut‐off (control group: n.145). All abnormalities resulted more frequent in exposed group: OR was 24.96 (p < 0.0001: 71.1% over vs. 9% below cut‐off) for overall abnormalities; 13.68 (p < 0.0001: 40.9% vs. 4.8%) for CEH; 6.13 (p < 0.002: 21.7% vs. 4.1%) for UC; 12.65 (p = 0.09: 3.6% vs. 0%) for M. Cystic endometrial hyperplasia represents the most common finding in adult bitches, followed by UC. A preventive sonographic screening for uterine abnormalities should start from 33% of expected longevity to preventively select animals requiring further evaluations.  相似文献   
98.
A 3-year-old Warmblood mare was presented with spinal ataxia of 3 months’ duration. Clinically, reduced mobility of the neck and a prominent atlas were identified. Neurological evaluation revealed hypermetria, circumduction and reduced proprioception, predominantly in the hindlimbs. Occipitoatlantoaxial malformation (OAAM) was diagnosed based on radiography and computed tomography, and confirmed on post-mortem magnetic resonance imaging and pathological examination. Both the atlas and axis were hypoplastic and dysplastic, and a fusion of the atlanto-occipital joint was found. A dynamic compression of the spinal cord was present at the first and second cervical vertebrae. Histologically, the spinal cord was degenerated due to compression. Furthermore, there were muscular malformations including a fibrotic obliquus capitis cranialis muscle, aplasia of parts of the rectus capitis muscles and presence of additional abnormal muscle. Such muscular abnormalities associated with OAAM have not been reported yet and this is the first report of a case of OAAM in a Warmblood horse.  相似文献   
99.
A 3‐day‐old male foal was presented with a fluctuant 25 × 15 cm mass on the thorax. The mass had increased in size since birth. The mass did not respond to conservative treatment consisting of aspiration of serohaemorrhagic contents and compression bandages, and it was therefore surgically removed when the foal was approximately 2½ weeks. A histopathological diagnosis of cavernous haemangioma was made. Healing progressed without complications despite a large surgical wound left to heal by second intention. Recurrence was not observed during the 1.5‐year follow‐up period.  相似文献   
100.

Background

Gallbladder mucocele (GBM) is an increasingly recognized extrahepatic biliary disease in dogs.

Objectives

To investigate cases of GBM and identify variables associated with survival and the sensitivity and specificity of ultrasonography to identify gallbladder rupture.

Animals

Two hundred and nineteen client‐owned dogs with GBM.

Methods

Multicenter, retrospective study of dogs with GBM, presented from January 2007 to November 2016 to 6 academic veterinary hospitals in the United States. Interrogation of hospital databases identified all cases with the inclusion criteria of a gross and histopathologic diagnosis of GBM after cholecystectomy and intraoperative bacteriologic cultures of at least 1 of the following: gallbladder wall, gallbladder contents, or abdominal effusion.

Results

Two hundred and nineteen dogs fulfilled the inclusion criteria. Dogs with GBM and gallbladder rupture with bile peritonitis at the time of surgery were 2.7 times more likely to die than dogs without gallbladder rupture and bile peritonitis (P = 0.001; 95% confidence interval [CI], 1.50–4.68; n = 41). No significant associations were identified between survival and positive bacteriologic cultures, antibiotic administration, or time (days) from ultrasonographic identification of GBM to the time of surgery. The sensitivity, specificity, positive, and negative likelihood ratios for ultrasonographic identification of gallbladder rupture were 56.1% (95% CI, 39.9–71.2), 91.7% (95% CI, 85.3–95.6), 6.74, and 0.44, respectively.

Conclusion and Clinical Importance

Dogs in our study with GBM and intraoperative evidence of gallbladder rupture and bile peritonitis had a significantly higher risk of death. Additionally, abdominal ultrasonography had low sensitivity for identification of gallbladder rupture.  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