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   65篇
  免费   6篇
林业   2篇
  8篇
综合类   14篇
畜牧兽医   46篇
植物保护   1篇
  2019年   2篇
  2017年   1篇
  2016年   2篇
  2015年   4篇
  2014年   1篇
  2013年   2篇
  2012年   5篇
  2011年   3篇
  2010年   2篇
  2009年   3篇
  2008年   1篇
  2007年   2篇
  2006年   1篇
  2005年   5篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   4篇
  1999年   1篇
  1996年   1篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   3篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1976年   1篇
  1972年   1篇
  1969年   1篇
  1968年   2篇
  1941年   1篇
排序方式: 共有71条查询结果,搜索用时 15 毫秒
51.
Modification of gastroduodenal motility has been proposed to aid endoscopic examination of the duodenum in dogs. The objective of this study was to evaluate the use of the following pharmacologic agents for facilitation of endoscopic intubation of the duodenum in 6 clinically normal dogs: metoclopramide HCl (0.2 mg/kg of body weight), atropine sulfate (0.045 mg/kg), glucagon (0.06 mg/kg), and isotonic saline solution. In a randomized, blinded, crossover design, the ease of endoscopic duodenal intubation was qualitatively scored by 3 endoscopists (in random order), using the following scale: 1 - immediate entry; 2 - rapid entry--moderate manipulation; 3 - difficult entry--multiple attempts; and 4 - no entry after 2 minutes [corrected]. Anesthesia was induced with thiopental and maintained with halothane. The 4 agents were diluted to a fixed volume and randomly administered. Duodenal intubation was attempted 2 minutes after IV injection of 1 of the agents. Four endoscopic procedures (1 for each agent) were performed on each dog with a minimum of 5 days between each procedure. In this study, no agent facilitated endoscopic duodenal intubation at the dose used. Instead, atropine and metoclopramide made duodenal intubation significantly more difficult, compared with use of saline solution. Difference between intubation after administration of glucagon and saline solution was not seen. On the basis of our findings, the use of these agents for facilitating endoscopic duodenal intubation is not recommended. In addition, in this study, we found that experience in endoscopic intubation is an important factor in determining the ease of duodenal intubation.  相似文献   
52.
The purpose of this experiment was to characterize a lesion of the rhamphotheca associated with tryptophan (TIRP) deficiency, search for other histological abnormalities,and determine whether bird size and housing conditions are contributing factors to these lesions. Day-old broiler chicks (Ross X Ross 308) were placed in either floor pens with fresh pine shavings or Petersime battery brooders with two pens of 10 chicks each per treatment. Broiler chicks from 0 to 21 days of age were fed adequate (0.24%) and deficient (0.09%) levels of TRP in diets based on corn, corn gluten meal, and gelatin. Separate groups of control chicks were pair fed daily with the deficient chicks. Deficient chicks grew less efficiently than did the pair-fed controls. Upon gross examination, a lesion of the maxillary rhamphotheca in the vicinity of the nares was observed in 61% of TRP-deficient birds housed in the battery and 13% of the birds housed in floor pens. A similar gross lesion was only observed in one control bird. These lesions were located along the upper portion of the beak between the nares and appeared as a crusty or scab-like area on gross examination, composed of detritus, heterophils, and plasma protein. Inflammation occasionally was observed at the dermoepidermal junction. The incidence of lesions was reduced in floor pens compared to battery brooders, but similarly sized birds did not exhibit the lesion. The number of lesions seen grossly and histologically in TRP-deficient birds, as compared to control birds, supports the hypothesis that TRP deficiency is the primary cause of these lesions around the nares of broilers. Secondary environmental factors, perhaps coprophagy, also influence the incidence of the lesion.  相似文献   
53.
54.
OBJECTIVE: To determine an infusion rate of butorphanol tartrate in horses that would maintain therapeutic plasma drug concentrations while minimizing development of adverse behavioral and gastrointestinal tract effects. ANIMALS: 10 healthy adult horses. PROCEDURE: Plasma butorphanol concentrations were determined by use of high-performance liquid chromatography following administration of butorphanol by single IV injection (0.1 to 0.13 mg/kg of body weight) or continuous IV infusion (loading dose, 17.8 microg/kg; infusion dosage, 23.7 microg/kg/h for 24 hours). Pharmacokinetic variables were calculated, and changes in physical examination data, gastrointestinal tract transit time, and behavior were determined over time. RESULTS: A single IV injection of butorphanol was associated with adverse behavioral and gastrointestinal tract effects including ataxia, decreased borborygmi, and decreased defecation. Elimination half-life of butorphanol was brief (44.37 minutes). Adverse gastrointestinal tract effects were less apparent during continuous 24-hour infusion of butorphanol at a dosage that resulted in a mean plasma concentration of 29 ng/ml, compared with effects after a single IV injection. No adverse behavioral effects were observed during or after continuous infusion. CONCLUSIONS AND CLINICAL RELEVANCE: Continuous IV infusion of butorphanol for 24 hours maintained plasma butorphanol concentrations within a range associated with analgesia. Adverse behavioral and gastrointestinal tract effects were minimized during infusion, compared with a single injection of butorphanol. Continuous infusion of butorphanol may be a useful treatment to induce analgesia in horses.  相似文献   
55.
Observations made during endoscopic evaluation of the stomach, duodenum, and colon of 58 dogs and 17 cats with a history of regurgitation, vomiting, and/or diarrhea were compared with results of histologic examination of tissues obtained during the procedures. Endoscopic observations included normal mucosa, alternations in mucosal color and texture, and luminal masses. Although endoscopy alone is a useful technique for detecting alterations of the gastrointestinal mucosa, histologic assessment of tissues obtained is necessary to confirm either an inflammatory or a neoplastic process.  相似文献   
56.
A 10-year-old German Shepherd Dog with intermittent eructation, borborygmi, flatulence, abdominal bloating, and vomiting was found to have gastric volvulus. Gastric emptying of liquids (determined with a modified emptying-time technique) was normal. Circumcostal gastropexy vastly reduced clinical signs and resulted in weight gain.  相似文献   
57.
58.
Background: Urinary catecholamines and metanephrines have been proposed as a diagnostic tool for identifying canine pheochromocytomas, but the effects of critical illness on urine concentrations of catecholamines and metanephrines currently are unknown. Objectives: To examine the effects of illness on urine concentrations of catecholamines and metanephrines in dogs. Animals: Twenty‐five critically ill dogs and 25 healthy age‐ and sex‐matched control dogs. Methods: Prospective observational study. Urine was collected from healthy and critically ill dogs, and urine concentrations of epinephrine, norepinephrine, metanephrine, and normetanephrine were measured by high‐performance liquid chromatography with electrochemical detection. Urinary catecholamine and metanephrine : creatinine ratios were calculated and compared between groups. Results: Urinary epinephrine, norepinephrine, metanephrine, and normetanephrine : creatinine ratios were higher in critically ill dogs when compared with a healthy control population (P= .0009, P < 0.0001, P < 0.0001, and P < 0.0001, respectively). Conclusions and Clinical Importance: Illness has a significant impact on urinary catecholamines and their metabolites in dogs. Further investigation of catecholamine and metanephrine concentrations in dogs with pheochromocytomas is warranted to fully evaluate this test as a diagnostic tool; however, the findings of this study suggest that the results may be difficult to interpret in dogs with concurrent illness.  相似文献   
59.

Background

The liver sampling technique in dogs that consistently provides samples adequate for accurate histopathologic interpretation is not known.

Hypothesis/Objectives

To compare histopathologic results of liver samples obtained by punch, cup, and 14 gauge needle to large wedge samples collected at necropsy.

Animals

Seventy dogs undergoing necropsy.

Methods

Prospective study. Liver specimens were obtained from the left lateral liver lobe with an 8 mm punch, a 5 mm cup, and a 14 gauge needle. After sample acquisition, two larger tissue samples were collected near the center of the left lateral lobe to be used as a histologic standard for comparison. Histopathologic features and numbers of portal triads in each sample were recorded.

Results

The mean number of portal triads obtained by each sampling method were 2.9 in needle samples, 3.4 in cup samples, 12 in punch samples, and 30.7 in the necropsy samples. The diagnoses in 66% of needle samples, 60% of cup samples, and 69% of punch samples were in agreement with the necropsy samples, and these proportions were not significantly different from each other. The corresponding kappa coefficients were 0.59 for needle biopsies, 0.52 for cup biopsies, and 0.62 for punch biopsies.

Conclusion and Clinical Importance

The histopathologic interpretation of a liver sample in the dog is unlikely to vary if the liver biopsy specimen contains at least 3–12 portal triads. However, in comparison large necropsy samples, the accuracy of all tested methods was relatively low.  相似文献   
60.
Before prioritising regional agroforestry training and extension content, it is necessary to discover which practices are common, what benefits are perceived, which barriers prevent use, and how people feel about practices. Agroforestry taps both agriculture and forestry agencies to increase the possible set of educators for landowners and managers. Interdisciplinary activities also present barriers to professionals unfamiliar with some topics or not served by lead partner agencies. To understand motives, barriers and needs involved in agroforestry extension and training activities for professionals, the Center for Subtropical Agroforestry (CSTAF) designed a survey to gauge knowledge, practice and information needs of professionals in Alabama, Florida and Georgia. Landowners in Alabama and Florida received similar survey questionnaires. Initial interviews of a test group with open-ended questions formed the basis for a closed-ended mail survey to all agriculture and natural resource extension agents and county foresters in the subtropical area. Response rates for various professional groups varied between 14% and 43%, and most ranked the potential for use of agroforestry as moderate or high. In all three states, wildlife habitat, water quality and soil conservation were the most important benefits seen by extension professionals. The most important concerns identified were lack of familiarity, lack of demonstrations, no financial incentive, and lack of information about agroforestry. These data provide insights about how to prioritise research and materials development and indicate that agroforestry training can be expected to be of value to at least half of the regional forestry and extension professionals.  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