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   343篇
  免费   55篇
林业   8篇
基础科学   5篇
  13篇
综合类   6篇
农作物   12篇
水产渔业   5篇
畜牧兽医   345篇
植物保护   4篇
  2024年   1篇
  2023年   13篇
  2022年   4篇
  2021年   8篇
  2020年   27篇
  2019年   5篇
  2018年   11篇
  2017年   15篇
  2016年   11篇
  2015年   16篇
  2014年   31篇
  2013年   23篇
  2012年   27篇
  2011年   19篇
  2010年   10篇
  2009年   23篇
  2008年   11篇
  2007年   9篇
  2006年   9篇
  2005年   5篇
  2004年   10篇
  2003年   7篇
  2002年   16篇
  2001年   9篇
  2000年   8篇
  1999年   3篇
  1998年   8篇
  1997年   1篇
  1996年   9篇
  1995年   2篇
  1994年   6篇
  1993年   3篇
  1992年   3篇
  1991年   4篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   3篇
  1984年   2篇
  1983年   1篇
  1976年   3篇
  1974年   2篇
  1973年   1篇
  1966年   1篇
  1960年   2篇
  1959年   1篇
  1958年   4篇
  1957年   2篇
排序方式: 共有398条查询结果,搜索用时 343 毫秒
81.
82.
83.
In 90 cats with naturally occurring feline immunodeficiency virus (FIV) infection, the clinicopathologic changes seen at the time of first diagnosis of FIV infection included lymphopenia (29%), neutrophilia (27%), monocytosis (23%), anemia (18%), leukocytosis (13%), leukopenia (13%), neutropenia (11%), hyperproteinemia (38%), and hyperglobulinemia (25%). Forty-nine (54%) of the cats showed multiple hematologic abnormalities, and a further 24 (17%) had a single abnormality. The most consistent changes in serum protein electrophoretic patterns were increases in the concentrations of alpha2 globulin and gammaglobulin subfractions. Although there is no established system for staging the degree of immunosuppression in cats infected with FIV, cytopenias appeared to be more commnn in cats with advanced clinical signs of disease.  相似文献   
84.
A prospective study was undertaken to compare the analgesic effect of intra-articular bupivacaine, morphine, or saline in the 24-hour period following cranial cruciate ligament repair in dogs. Thirty-six clinical patients with ruptured cranial cruciate ligaments were randomly assigned to one of three groups. After surgical stabilization, and before skin closure, an intra-articular injection was given; group one (n = 12) received 0.5% bupivacaine HCl at 0.5 mL/kg, group two (n = 12) received morphine at 0.1 mg/kg diluted with saline to a volume of 0.5 mL/kg, and group three (n = 12) received saline at 0.5 mL/kg. Heart rate, respiratory rate, mean arterial blood pressure, cumulative pain score, visual analog pain score, and pain threshold test on both stifles were recorded preoperatively and at 0 to 6 and 24 hours postoperatively. Surgeons and pain scoring investigators were unaware of the intra-articular medication given. Supplemental analgesia, if needed, was provided in the postoperative period according to subjective assessment of patient discomfort. Postoperative pain scores were lowest in the bupivacaine group and highest in the saline group. Pain threshold, measured by applying calibrated loads to the knee, was higher postoperatively in the bupivacaine group than in the saline group. Dogs in the morphine and bupivacaine groups required less supplemental analgesia than dogs in the saline group. The local provision of analgesia reduces the need for systemic drugs with potential side effects. Both intra-articular morphine and intra-articular bupivacaine provided better postoperative analgesia than intra-articular saline, with intra-articular bupivacaine showing the greatest effect.  相似文献   
85.
Seventeen serum biochemical variables were determined in 40 donkeys of the Brazilian breed (34 females and 6 males) aged from 3 to 19 years. Mean ± standard deviation (SD) (minimum–maximum) values, obtained by automated analysis, were as follows: glucose, 58.35 ± 10.40 (44.00–90.00) mg/dL; cholesterol, 88.41 ± 9.86 (73.58–124.26) mg/dL; serum protein, 6.82 ± 0.40 (6.00–7.52) g/dL; albumin, 3.13 ± 0.21 (2.65–3.69) g/dL; creatinine, 1.80 ± 0.14 (1.51–2.19) mg/dL; urea, 24.25 ± 5.37 (14.12–34.39) mg/dL; lactate, 20.10 ± 4.58 (12.99–33.47) mg/dL; aspartate aminotransferase (AST), 295.81 ± 62.79 (173.71–466.07) IU/L; creatine kinase (CK), 158.00 ± 76.94 (51.69–440.33) IU/L; γ-glutamil-transferase (GGT), 45.82 ± 13.34 (26.17–86.38) IU/L; lactate dehydrogenase (LDH), 576.02 ± 156.32 (213.53–1162.81) IU/L; alkaline phosphatase (AP), 345.36 ± 65.90 (227.25–490.16) IU/L; calcium (Ca), 8.54 ± 0.18 (8.19–8.90) mg/dL; phosphorus (P), 2.76 ± 0.38 (1.99–3.97) mg/dL; chloride (Cl), 106.05 ± 3.20 (99.00–112.00) mEq/L; sodium (Na), 121.50 ± 4.14 (116.00–132.00) mEq/L; and potassium (K), 3.70 ± 0.42 (2.80–4.40) mEq/L. Comparisons of biochemical ranges obtained for the Brazilian donkey breed with reference ranges for other donkey breeds suggested that most values were similar. Biochemical values determined in the present study serve as reference ranges for donkey populations and can be used for health control and diagnosis of diseases.  相似文献   
86.
The holding power of orthopedic screws in the third metacarpal and metatarsal cadaver bones of foals that were aged from 1 to 14 days was tested. Comparative trials between screws inserted at the same site in contralateral bones from the same foal were performed to compare the holding power of 5.5 mm cortical and 6.5 mm cancellous screws in the metaphysis, and the holding power of 5.5 and 4.5 mm cortical screws in the diaphysis. A MTS servohydraulic tensile testing machine was used to perform screw pullouts at a displacement rate of 19 mm/sec. There was no significant difference between maximum holding power of 5.5 mm cortical screws and 6.5 mm cancellous screws in the metaphysis when expressed as kg per mm of bone width at the screw insertion site (p = 0.097) or as kg per mm of screw thread engaged in the bone (p = 0.17). There was no significant difference in holding power of 5.5 and 6.5 mm screws in the proximal versus distal metaphysis (p = 0.10). The 5.5 mm screws had significantly greater holding power than the 4.5 mm screws in the diaphysis (p = 0.0097). Fixation failure at screw pullout was always due to bone shear. In internal fixation in foal bone, the 5.5 mm screws may be a suitable alternative to 6.5 mm screws in the metaphysis. Use of 5.5 mm rather than 4.5 mm screws is recommended in the diaphysis because of greater holding power.  相似文献   
87.
88.

Objective

To investigate the effects of a low dose of dexmedetomidine (DEX) followed by constant rate infusion (CRI) and reversal with atipamezole on systolic and diastolic functions in isoflurane-anesthetized healthy cats.

Study design

Prospective cohort study.

Animals

A group of 11 client-owned adult cats.

Methods

Baseline transthoracic echocardiography (TTE) was performed, followed by intramuscular (IM) administration of DEX (5 μg kg?1). After 10 minutes, sedation was scored, adverse effects were recorded and another TTE performed. Approximately 40 minutes after DEX administration, anesthesia was induced by isoflurane mask and maintained with 1.2% end-tidal isoflurane and DEX CRI (1 μg kg?1 hour?1) for 80 minutes. Physiological variables were recorded every 10 minutes, and TTE was repeated 10, 30 and 60 minutes after the start of anesthesia. CRI was stopped, atipamezole (30 μg kg?1) was administered IM and a final TTE was performed after 10 minutes. Repeated measures over time were submitted to one-way analysis of variance or Kruskal–Wallis test according to data distribution; significance was assumed at p < 0.05.

Results

After DEX premedication, mild sedation and a slight but significant increase in systolic arterial pressure occurred, and vomiting was a common adverse effect. The cardiac output (CO) and heart rate decreased during anesthesia, with no changes after administration of atipamezole. Trivial valvular insufficiencies were commonly seen after DEX premedication and during CRI. Myocardial radial and longitudinal systolic functions were not affected by sedation or by anesthesia. The late phase of diastole on both right and left ventricles was affected by isoflurane–DEX CRI. Global left ventricular myocardial performance was not impaired.

Conclusions

and clinical relevance Decreased CO and late diastolic impairment were observed in healthy cats administered a low dose of DEX for premedication followed by anesthesia with isoflurane and DEX CRI.  相似文献   
89.
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