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   466篇
  免费   79篇
林业   9篇
农学   3篇
  19篇
综合类   73篇
农作物   8篇
水产渔业   21篇
畜牧兽医   398篇
园艺   3篇
植物保护   11篇
  2022年   4篇
  2020年   9篇
  2019年   5篇
  2018年   7篇
  2017年   18篇
  2016年   8篇
  2015年   7篇
  2014年   18篇
  2013年   25篇
  2012年   29篇
  2011年   16篇
  2010年   9篇
  2009年   19篇
  2008年   21篇
  2007年   20篇
  2006年   13篇
  2005年   9篇
  2004年   13篇
  2003年   19篇
  2002年   10篇
  2001年   6篇
  2000年   16篇
  1999年   12篇
  1998年   21篇
  1996年   10篇
  1995年   7篇
  1994年   6篇
  1993年   11篇
  1992年   6篇
  1991年   18篇
  1990年   8篇
  1989年   14篇
  1988年   6篇
  1987年   6篇
  1986年   4篇
  1985年   11篇
  1984年   9篇
  1983年   9篇
  1982年   5篇
  1981年   3篇
  1980年   4篇
  1979年   3篇
  1978年   5篇
  1977年   9篇
  1975年   5篇
  1974年   4篇
  1973年   7篇
  1972年   6篇
  1967年   6篇
  1966年   4篇
排序方式: 共有545条查询结果,搜索用时 15 毫秒
481.
482.
483.
Background: Transarterial ductal occlusion with the Amplatzer vascular plug was first reported in dogs by Hogan et al in 2005. Hypothesis: Use of the Amplatzer vascular plug is a safe, efficacious method of patent ductus arteriosus (PDA) occlusion. Animals: Thirty‐one client‐owned dogs with PDA. Methods: Records of 31 dogs in which transarterial occlusion of PDA with an Amplatzer vascular plug was attempted were reviewed. Results: All dogs had a type II PDA, with 27 dogs having type IIA morphology and 4 dogs having type IIB morphology. Appropriate device deployment was achieved in 29 of 31 dogs. Postdeployment angiography in 21 dogs documented complete occlusion in 10 dogs, trivial residual flow in 5 dogs, mild residual flow in 2 dogs, moderate residual flow in 3 dogs, and severe residual flow in 1 dog. Transthoracic color Doppler echocardiography documented complete occlusion in 22 dogs, whereas 2 dogs had trivial residual flow, 2 dogs had mild residual flow, 2 dogs had mild to moderate residual flow, and 1 dog had severe residual flow. Of the 7 dogs with residual flow, 2 had complete occlusion 2–4 months postoperatively, 1 had moderate residual flow 1 month postoperatively, and 4 were lost to follow‐up. One dog required a larger device than was able to be deployed through the largest sheath placed in the femoral artery. Pulmonary embolization of the device occurred in 1 dog. Conclusion: We conclude that ductal occlusion with an Amplatzer vascular plug is a safe and efficacious therapy for PDA in dogs.  相似文献   
484.
ObjectiveTo evaluate the effect of medetomidine–butorphanol sedation on serum cardiac troponin I (cTnI) concentration, a marker of myocardial ischemia and injury, in healthy dogs undergoing pre–surgical radiographs for orthopedic procedures.Study designProspective clinical study.AnimalsTwenty client–owned dogs with no history of cardiac disease.MethodsDogs were evaluated for pre–existing cardiac disease with electrocardiogram (ECG), noninvasive blood pressure and echocardiogram. Sedation was achieved using a combination of medetomidine (10 μg kg?1) and butorphanol (0.2 mg kg?1) intravenously. Blood pressure, heart rate and ECG were serially recorded throughout the duration of sedation. Serum cTnI concentration was measured at baseline and 6, 18, and 24–hours post–sedation.ResultsFollowing administration of medetomidine and butorphanol, all dogs were adequately sedated for radiographs and had a decreased heart rate and increased diastolic blood pressure. Arrhythmias associated with increased parasympathetic tone occurred, including a sinus arrhythmia further characterized as a sinus bigeminy in 17 of the dogs. Serum cTnI was undetectable at all time points in all but three dogs. Two of the three dogs had a detectable concentration of cTnI at all time points measured, including prior to sedation. Only one of the two dogs had a cTnI concentration above the normal reference interval. The dogs that exhibited detectable cTnI had no significant difference in signalment, heart rate, blood pressure, or lactate concentration as compared to those with undetectable cTnI.Conclusions and clinical relevanceSedation with medetomidine and butorphanol had predictable cardiovascular effects including bradycardia, an increase in arterial blood pressure, and arrhythmias in apparently healthy dogs requiring radiographs for orthopedic injuries, but did not induce significant increases in serum cTnI concentration following the drug doses used in this study.  相似文献   
485.
486.
487.
488.

Objectives

To describe signalment, clinical characteristics, diagnostic, treatment, and outcome data in a large case series of cats with patent ductus arteriosus (PDA).

Animals

Fifty cats with confirmed PDA.

Methods

Retrospective review of medical records from five referral veterinary hospitals for cats with PDA between 2000 and 2015. Cats were included if a PDA was visualized echocardiographically, during surgery, or on post-mortem examination.

Results

Median age at presentation was 6 months (range: 36 days–9.7 years; n = 50), and sex distribution was approximately equal (27 male, 23 female). Most cats did not have clinical signs (70.2%; 33/47) at the time of presentation. Murmurs were classified as continuous (55%; 22/40) or systolic (45%; 18/40). Echocardiography confirmed left-to-right shunting in 33 cats (82.5%; 33/40) and right-to-left shunting in 7 (17.5%; 7/40). Concurrent cardiac anomalies were identified in 54.5% (18/33) and pulmonary hypertension in 45.7% (16/35). Closure was pursued in 68% (34/50), and complications associated with the procedure occurred in 14.7% (5/34) of cats, including one intraoperative mortality. Long-term follow up was available in 80% (40/50) of cats.

Conclusions

Cats with PDA often do not display clinical signs and may not have the characteristic physical examination findings typical of PDA in dogs. An increased prevalence of concurrent cardiac anomalies and pulmonary hypertension were found relative to previous reports. Thoracic radiographs and echocardiogram may provide the most comprehensive information for making a diagnosis and treatment recommendations. PDA closure was associated with a favorable long-term outcome in cats included in this study.  相似文献   
489.
490.
A 5-year old, 5.8 kg, castrated male Pomeranian was diagnosed with a type IIa patent ductus arteriosus (PDA) with a minimal ductal diameter of 3.5 mm and ampulla width of 7.1 mm based on angiographic assessment. A 6 mm Amplatz® Canine Duct Occluder (ACDO) was deployed within the PDA. Once deployed, the device assumed it's native shape and back-and-forth maneuvering was performed with the delivery cable to assess device stability. Device position and complete occlusion were confirmed with both angiography and transesophageal echocardiography prior to and after release of the device. The device location was confirmed within the ductus arteriosus by echocardiography prior to discharge. The dog was discharged with instructions for strict activity restriction. Two days after discharge, the dog was left unsupervised in the backyard and shortly afterwards was found coughing with severe respiratory distress. The dog was evaluated at an emergency hospital and thoracic radiographs documented embolization of the ACDO to the main pulmonary artery along with a severe alveolar pattern throughout the right lung fields. Shortly after obtaining thoracic radiographs, the dog experienced cardiopulmonary arrest with unsuccessful resuscitation. This case describes a possible complication of transcatheter PDA occlusion with an ACDO, which has not been previously reported. An incident report, or catalog of adverse events with these devices, may prove useful in identifying additional fatal complications that others may have encountered, but are not reported in the literature. The report of this complication emphasizes the importance of strict activity restriction after device placement in dogs.  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