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   177篇
  免费   4篇
林业   8篇
农学   4篇
基础科学   3篇
  25篇
综合类   16篇
农作物   3篇
水产渔业   1篇
畜牧兽医   104篇
园艺   12篇
植物保护   5篇
  2021年   1篇
  2020年   1篇
  2019年   9篇
  2018年   2篇
  2017年   2篇
  2016年   2篇
  2015年   6篇
  2014年   5篇
  2013年   9篇
  2012年   11篇
  2011年   13篇
  2010年   10篇
  2009年   7篇
  2008年   10篇
  2007年   11篇
  2006年   16篇
  2005年   15篇
  2004年   10篇
  2003年   10篇
  2002年   12篇
  2001年   1篇
  2000年   2篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
排序方式: 共有181条查询结果,搜索用时 109 毫秒
1.
Pleural effusions from 23 dogs and 25 cats hospitalized between November 1986 and April 1987 at the Veterinary Hospital of the University of Pennsylvania (VHUP) were classified as chylous (chylomicrons present) or nonchylous (chylomicrons absent) by the presence or absence, respectively, of a chylomicron band on lipoprotein electrophoresis gels of the effusions. Triglyceride concentrations, cholesterol concentrations, and cholesterol/triglyceride (C/T) ratios were compared between the chylous and nonchylous groups in each species. Cholesterol concentrations were not significantly different between chylous and nonchylous effusions in both dogs and cats. Cholesterol/triglyceride ratios of less than 1 were present in all dogs and cats with chylous effusions; however, 12% of dogs with nonchylous effusions and 50% of cats with nonchylous effusions also had a C/T ratio less than 1. Triglyceride concentrations accurately classified all effusions as chylous or nonchylous in both dogs and cats. Pleural effusions with triglyceride concentrations greater than l00 mg/dl were chylous in all cases, whereas, effusions with triglyceride concentrations less than l00 mg/dl were nonchylous in all cases.  相似文献   
2.
3.
OBJECTIVE: To evaluate primary hemostasis following administration of desmopressin acetate (DDAVP) to Doberman Pinschers with type-1 von Willebrand disease (vWD). ANIMALS: 16 nonanemic Doberman Pinschers with type-1 vWD. PROCEDURE: Closure time (CT), defined as time required for occlusion of an aperture by a platelet plug assessed within the point-of-care instrument, plasma von Willebrand factor (vWF) concentration, and buccal mucosal bleeding time (BMBT) were determined before and 1 hour after administration of DDAVP (1 microg/kg, SC). RESULTS: Baseline closure times measured with adenosine diphosphate ([ADP-CT], 108 to > 300 seconds; reference range, 52 to 86 seconds) and epinephrine ([EPI-CT], 285 to > 300 seconds; 97 to 225 seconds) as platelet agonists were prolonged in all dogs. Following DDAVP administration, ADP-CT (59 to 186 seconds) was significantly shortened from baseline, but there was no decrease in EPI-CT. Although mean plasma vWF concentration increased significantly after DDAVP administration, only 1 dog had an increase of > 35 U/dL. There was no correlation between increase in plasma vWF concentration and shortening of the ADP-CT. Baseline BMBT was prolonged in 12 of 14 dogs, with significant shortening of BMBT after DDAVP administration in 6 of 7 dogs. In vitro replacement of vWF-deficient plasma with plasma from an unaffected dog shortened the ADP-CT whereas in vitro addition of DDAVP had no effect. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of DDAVP to Doberman Pinschers with type-1 vWD resulted in improved hemostatic function, as assessed by the point-of-care instrument and shortening of BMBT, despite minimal increase in plasma vWF concentration.  相似文献   
4.
Canine leukocyte adhesion deficiency (CLAD) is a primary immunodeficiency disease characterized by recurrent bacterial infections in the presence of marked leukocytosis. The disease was 1st described in the mid-1980s in a cross-breed Irish Setter Dog in the United States. It results from a defective beta-2 subunit of heterodimeric leukocyte adhesion proteins. The causative mutation for CLAD in Irish Setter Dogs from Europe has been identified as a missense mutation at base pair position 107 in the beta-2 integrin subunit gene (ITGB2) that results in an amino acid change from cysteine to serine at amino acid 36 (Cys36Ser) in the beta-2 integrin subunit protein. In the current work, the originally described dog with CLAD has been genetically tested and shown to have the same mutation as the European Irish Setters. This suggests that the mutation has been in the Irish Setter population for many generations spanning more than 2 decades. A related breed, the Irish Red and White Setter, has a history of interbreeding with Irish Setters and shares a common ancestry with the Irish Setter breed. DNA from Irish Red and White Setters residing in the United States was screened either by sequencing or by the newly developed restriction enzyme test for the Irish Setter Cys36Ser CLAD mutation. Seven of 54 dogs tested (13%) were found to be carriers of the Irish Setter CLAD mutation. Five of these were directly related to a sire from the UK, demonstrating the importation of an allele from another continent and establishing the need for genetic testing in this breed in the United States.  相似文献   
5.
Our purpose was to identify the main hazards associated with the spread of Listeria monocytogenes in dairy products in Switzerland and to determine the changes in predominant serotypes of the isolates, using databases on dairy-processing and environments from the Swiss Dairy Research Station during the years 1990-1999. Overall, of 76,271 samples collected, 3722 (4.9%) were positive for the presence of L. monocytogenes. Cheese-ripening facilities had the highest proportion of positive samples (7.6%), followed by small-scale local dairies (4.4%). By sample type, the highest proportion of positive samples (9.5%) was observed in water samples used for cheese-washing, followed by cheese-surface swabs (5.0%). During the 10-year period, no positive samples were obtained from cream, ice cream, milk powder, yogurt, or fresh cheese. Of 3722 L. monocytogenes isolates, 1328 (35.7%) were serologically typeable. Serotypes 1/2a, 1/2b, and 4b accounted for 92.7% of the 1328 isolates. Until 1995, the most-prevalent serotype was 1/2b (annual proportional prevalence 39.3-72.2%)--whereas since 1996, 1/2a was the most prevalent (34.7-54.7%). During 1996-1999, serotype 1/2a increased by 88%, compared to the average of 1990-1995. In the final random-effect multivariable logistic model, the strongest predictor of a positive culture was samples from cheese-ripening plant (OR=1.54; 95% CI: 1.14, 2.08) and the second-strongest predictor was samples collected by someone who was employed by the plant (OR=1.48; 1.29, 1.71). Hard and semi-hard cheeses were more likely to be associated with serotype 1/2b and soft cheeses with serotype 1/2a.  相似文献   
6.
We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms. The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely, of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions. In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to further reduce its phytotoxic side effects.  相似文献   
7.
A 5-year-old guinea pig was presented to the University of Berne Small Animal Radiology Department for an ultrasound examination of the abdomen to confirm a suspected diagnosis of Cushing's syndrome. The patient had bilateral alopecia, was apathic and obese. Ultrasonographically, a tumor of the left adrenal gland, obstruction of the left ureter by an ureterolith, as well as hydronephrosis of the left kidney were detected. During surgery to relieve the ureteral obstruction the adrenal gland tumor was removed. The guinea pig died post-operatively due to blood loss. The left adrenal gland tumor was found histopathologically to be an adenoma and the right adrenal gland also had multiple small adenomas, but grossly appeared normal. The ureterolith was analyzed and found by x-ray diffraction to consist of calcium carbonate.  相似文献   
8.
A new acylated quercetin glycoside, quercetin 3-O-(2-t-p-coumaroyl)-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranoside-7-O-beta-D-glucopyranoside (1), together with the known 3-(3,4-dihydroxyphenyl)lactic acid (2) were isolated from Ranunculus lanuginosus leaves and identified on the basis of detailed spectral analysis, including 2D-NMR spectrometry and ESI-MS.  相似文献   
9.
Erythrocyte pyruvate kinase (PK) deficiency is an inherited glycolytic erythroenzymopathy caused by mutations of the PKLR gene. A causative mutation of the feline PKLR gene was originally identified in Abyssinian and Somali cats in the U.S.A. In the present study, a TaqMan probe-based real-time PCR genotyping assay was developed and evaluated for rapid genotyping and large-scale screening for this mutation. Furthermore, a genotyping survey was carried out in a population of four popular purebred cats in Japan to determine the current mutant allele frequency. The assay clearly displayed all genotypes of feline PK deficiency, indicating its suitability for large-scale survey as well as diagnosis. The survey demonstrated that the mutant allele frequency in Abyssinian and Somali cats was high enough to warrant measures to control and prevent the disease. The mutant allele frequency was relatively low in Bengal and American Shorthair cats; however, the testing should still be carried out to prevent the spread of the disease. In addition, PK deficiency should always be considered in the differential diagnosis of anemia in purebred cats in Japan as well as worldwide.  相似文献   
10.
Two Quarter horses with weight loss had glucosuria, euglycemia, and a mild metabolic acidosis suggesting a proximal renal tubular defect. Further testing revealed transient generalized aminoaciduria, lactic aciduria, and glucosuria, indicating Fanconi syndrome. Both horses recovered with supportive therapy. This is the first report of acquired Fanconi syndrome in horses.  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