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   5065篇
  免费   479篇
农学   3篇
综合类   3篇
水产渔业   10篇
畜牧兽医   5517篇
植物保护   11篇
  2024年   7篇
  2023年   90篇
  2020年   167篇
  2019年   2篇
  2018年   122篇
  2017年   134篇
  2016年   86篇
  2015年   140篇
  2014年   225篇
  2013年   244篇
  2012年   181篇
  2011年   214篇
  2010年   166篇
  2009年   252篇
  2008年   151篇
  2007年   102篇
  2006年   83篇
  2005年   81篇
  2004年   143篇
  2003年   147篇
  2002年   166篇
  2001年   159篇
  2000年   122篇
  1999年   118篇
  1998年   171篇
  1997年   180篇
  1996年   159篇
  1995年   161篇
  1994年   141篇
  1993年   151篇
  1992年   175篇
  1991年   148篇
  1990年   188篇
  1989年   131篇
  1988年   113篇
  1987年   146篇
  1986年   58篇
  1985年   79篇
  1984年   85篇
  1983年   80篇
  1982年   35篇
  1981年   13篇
  1980年   5篇
  1978年   2篇
  1977年   3篇
  1976年   4篇
  1974年   4篇
  1960年   2篇
  1956年   2篇
  1946年   1篇
排序方式: 共有5544条查询结果,搜索用时 15 毫秒
81.
The results of clinical and pulmonary functional evaluation of 24 cats with bronchopulmonary disease and 15 healthy cats are presented. Affected cats had historical evidence of excessive reflexes (coughing, sneezing); physical evidence of airway secretions (crackles), obstruction (wheezing), and increased tracheal sensitivity; radiographic evidence of bronchial and interstitial lung disease; and cytological evidence of airway inflammation or mucous secretions. Bacterial isolates from healthy and affected cats were predominantly Gram-negative rods, indicating that bronchi of cats are not always sterile and that normal flora should be considered in interpreting cultures from cats with suspected bronchopulmonary disease. Cats were grouped according to relative disease severity based on scored historical, physical, and radiographic abnormalities. The mean (± standard deviation) baseline lung resistance measurement in healthy cats was 28.9 cm H2O/L/s (±6.2 cm H2O/L/s), whereas in mildly, moderately, and severely affected cats it was 38.3 cm H2O/L/s (±21.5 cm H2O/L/s), 44.8 cmH2O/L/s (±7.7 cm H2O/L/s), and 105.2 cm H2O/L/s (±66.9 cm H2O/L/s), respectively. In healthy cats, dynamic lung compliance was 19.8 (±7.4), whereas in mildly, moderately, and severely affected cats it was 14.7 mL/cm H2O (±3.8 mL/cm H2O), 17.7 mL/cm H2O (±6.9 mL/cm H2O), and 13.0 mL/cm H2O (±7.9 mL/cm H2O), respectively. Thus, airway obstruction was present in many of the affected cats. Based on acute response to the bron-chodilator, terbutaline, airway obstruction was partially reversible in many affected cats, although the degree of reversibility varied. Furthermore, based on bronchoprovocation testing, 6 (of 7) affected cats evaluated also had increased airway responsiveness to aerosolized methacholine.  相似文献   
82.
83.
84.
85.
86.
87.
88.
A 12-year-old Thoroughbred gelding exhibited a unilateral exophthalmos on the left side. There had been no other clinical symptoms, such as rhinorrhea, before the first consultation. Clinical, hematologic, plasma biochemical, cytologic, and computed tomography (CT) examinations and complete necropsy were performed. These examinations did not reveal neoplastic lesions. CT images suggested that maxillary and frontal sinuses may have been filled with fluid. Cytologic and pathologic examinations revealed that the maxillary and orbital bones were pushed up with a large amount of the inflammatory fluid effused by chronic sinusitis. The CT and cytologic examinations were of great use for differential diagnosis in this case. This was an unusual case of exophthalmos induced by deformation of the orbital bones resulting from chronic sinusitis.  相似文献   
89.
Objective – To compare the placement feasibility and amount of bone trauma induced by 3 intraosseous (IO) access techniques in cats: an automatic impact penetration device (A), an automatic rotary insertion device (B), and a manual IO needle (C). Design – Prospective ex vivo study. Setting – University. Animals – Eighteen adult mixed breed feline cadavers. Interventions – Cadavers provided 72 total IO insertion locations divided equally between the right and left humerus and tibia. The 3 IO techniques were randomly allocated to these locations. Time to successful insertion, ease of insertion, and success rate were recorded. Each insertion site was analyzed for the number of bone fragments and defect diameter by computed tomography. Measurements and Main Results – Device B had lower time of insertion (P=0.01) compared with devices A and C. Device B had better ease of insertion scores (P<0.01) compared with devices A and C. No differences were detected between insertion sites (tibia versus humerus). No differences in the number of bone fragments, defect diameter, or success rate were detected among devices (P=0.06, 0.31, and 0.14, respectively). Conclusions – All 3 IO access methods evaluated yield acceptable results. Device B is significantly faster and easier to place in cat cadavers when compared with other methods.  相似文献   
90.
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