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   184篇
  免费   23篇
林业   6篇
农学   1篇
  16篇
综合类   56篇
农作物   1篇
水产渔业   7篇
畜牧兽医   115篇
园艺   3篇
植物保护   2篇
  2023年   2篇
  2022年   4篇
  2021年   2篇
  2020年   5篇
  2019年   6篇
  2018年   5篇
  2016年   9篇
  2015年   2篇
  2014年   6篇
  2013年   10篇
  2012年   3篇
  2011年   5篇
  2010年   4篇
  2008年   5篇
  2007年   5篇
  2006年   8篇
  2005年   6篇
  2004年   9篇
  2003年   4篇
  2002年   7篇
  2000年   5篇
  1997年   2篇
  1996年   2篇
  1993年   2篇
  1992年   4篇
  1991年   3篇
  1988年   7篇
  1987年   5篇
  1986年   3篇
  1983年   3篇
  1981年   3篇
  1979年   2篇
  1975年   2篇
  1974年   2篇
  1972年   4篇
  1971年   2篇
  1970年   2篇
  1969年   4篇
  1968年   2篇
  1967年   3篇
  1938年   2篇
  1923年   2篇
  1921年   2篇
  1917年   1篇
  1916年   1篇
  1914年   1篇
  1911年   2篇
  1910年   2篇
  1898年   1篇
  1885年   1篇
排序方式: 共有207条查询结果,搜索用时 109 毫秒
61.
A study was conducted to evaluate the nutrient content and variability of distiller's dried grains with solubles (DDGS) originating from new (less than 5 yr old) ethanol plants in Minnesota and South Dakota. Ten plants (8 MN, 2 SD) participated in the study, submitting a total of 118 samples. Samples were collected every 2 mo from ten ethanol plants in the Minnesota-South Dakota (MNSD) region from 1997 to 1999 and were analyzed for amino acid levels, DM, CP, crude fiber, crude fat, ash, ADF, NDF, Ca, P, K, Mg, S, Na, Zn, Mn, Cu, and Fe analysis. Digestible energy (DE), ME, and NFE levels were also calculated. Means (dry-matter basis) and coefficients of variation for each nutrient among all plants during 1997 to 1999 were DM (88.9%, 1.7%), CP (30.2%, 6.4%), crude fat (10.9%, 7.8%), crude fiber (8.8%, 8.7%), ash (5.8%, 14.7%), NFE (45.5%, 6.1%), ADF (16.2%, 28.4%), NDF (42.1%, 14.3%), calculated DE (3,990 kcal/kg, 3.24%), calculated ME (3,749 kcal/kg, 3.28%), Arg (1.20%, 9.1%), His (0.76%, 7.8%), Ile (1.12%, 8.7%), Leu (3.55%, 6.4%), Lys (0.85%, 17.3%), Met (0.55%, 13.6%), Phe (1.47%, 6.6%), Thr (1.13%, 6.4%), Trp (0.25%, 6.7%), Val (1.50%, 7.2%), Ca (0.06%, 57.2%), and P (0.89%, 11.7%), respectively. Among the amino acids analyzed, Lys was the most variable (CV = 17.3%), followed by Met (CV = 13.6%). Nutrient levels of MNSD DDGS were higher in crude fat, NDF, DE, ME, P, Lys, Met, and Thr and lower for DM, ADF, and Ca than NRC (1998) values. Nutrient values differed between years for ash, DE, Mn, Zn, Cys (P < 0.10), Fat, TDN, ME, Met, Ile (P < 0.05), Ca, P, K, Mg, and Cu (P < 0.01). These results suggest that gross energy; P; and total Lys, Met, and Thr levels are higher in DDGS from MNSD ethanol plants compared to published values and chemical analysis values of a DDGS sample obtained from an older Midwestern plant.  相似文献   
62.
63.
64.
65.
66.
A 6‐year‐old, male castrated, domestic shorthair cat presented with a 2‐week history of blindness following general anesthesia. Behavioral changes, lethargy, inappetence and neurological deficits were also noted. Ophthalmic evaluation revealed blindness, normal pupillary light response and dazzle response, but no other abnormalities. Serodiagnostic testing for common infectious agents was negative and a cerebrospinal fluid analysis was normal. History and postmortem examination following euthanasia revealed cerebrocortical necrosis most consistent with anesthesia related hypoxia.  相似文献   
67.
68.
Fifty-six dogs from St. John's, Newfoundland, Canada, were evaluated for Angiostrongylus vasorum infection. Small numbers of nematodes were found within pulmonary arteries of 6 dogs. Larvae were identified in fecal samples in 2 of 6 dogs. All 6 dogs had multifocal granulomatous pneumonia and sometimes foci of chronic thrombosis, which varied from very mild to severe. One dog had extensive pulmonary lesions resulting in cor pulmonale. Right heart failure was characterized by right ventricular hypertrophy, hepatic congestion, ascites, and hydrothorax. Microscopically, in most cases, eggs, larvae, and sometimes intravascular adults, were present within lung tissue sections. Small foci of granulomatous inflammation with and without larvae were present in kidney and brain in 4 dogs. An additional dog, diagnosed antemortem with angiostrongylosis via fecal examination, was also examined. Pathological findings consisted of severe pyogranulomatous interstitial pneumonia with myriad eggs, larvae, and numerous intravascular pulmonary adult nematodes with extensive arterial thrombosis. Five hundred and seventy-two adult worms were removed from pulmonary arteries. Foci of granulomatous inflammation, often associated with larvae and/or eggs, were present in tracheobronchial lymph nodes, adrenal gland, brain, and kidneys. Severe seizuring noted antemortem was attributed to several large, discrete areas of acute hemorrhagic infarction within the cerebrum and cerebellum. Natural A. vasorum infection in domestic dogs in eastern Newfoundland causes lung pathology of variable severity, which in some cases, may progress to cor pulmonale and which may be associated with extrapulmonary lesions and clinical signs.  相似文献   
69.
70.
OBJECTIVE: To determine the effect of 2 doses of metoclopramide on the incidence of gastroesophageal reflux (GER) in anesthetized dogs. ANIMALS: 52 healthy dogs undergoing elective orthopedic surgery. PROCEDURE: In this prospective clinical study, dogs were evaluated before and during orthopedic surgery. The anesthetic protocol used was standardized to include administration of acepromazine, morphine, thiopental, and isoflurane. Dogs were randomly selected to receive an infusion of saline (0.9% NaCl) solution, a low dose of metoclopramide, or a high dose of metoclopramide before and during anesthesia. Treatment groups were similar with respect to age, body weight, duration of food withholding before surgery, duration of surgery, and dose of thiopental administered. Dogs were positioned in dorsal recumbency during surgery. A sensor-tipped catheter was inserted to measure esophageal pH during anesthesia. We defined GER as a decrease in esophageal pH to < 4 or an increase to > 7.5 that lasted more than 30 seconds. RESULTS: The high dose of metoclopramide (bolus loading dose of 1.0 mg/kg, IV, followed by continuous infusion at a rate of 1.0 mg/kg/h) was associated with a 54% reduction in relative risk of developing GER. The low dose did not significantly affect the incidence of GER. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of metoclopramide by bolus and constant rate infusion at doses much higher than commonly used will reduce the incidence but not totally prevent GER in anesthetized dogs undergoing orthopedic surgery.  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