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   84篇
  免费   3篇
农学   2篇
  3篇
综合类   6篇
农作物   1篇
水产渔业   2篇
畜牧兽医   63篇
园艺   2篇
植物保护   8篇
  2022年   2篇
  2021年   4篇
  2020年   3篇
  2019年   3篇
  2018年   1篇
  2017年   3篇
  2015年   2篇
  2014年   3篇
  2013年   2篇
  2012年   9篇
  2011年   5篇
  2010年   3篇
  2009年   3篇
  2008年   1篇
  2007年   1篇
  2006年   3篇
  2005年   5篇
  2004年   3篇
  2003年   2篇
  2002年   6篇
  1997年   1篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1991年   1篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1932年   1篇
  1927年   1篇
排序方式: 共有87条查询结果,搜索用时 46 毫秒
31.
Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.  相似文献   
32.
33.
分别采用加热与季也蒙毕赤酵母以及二者相结合的方式对采后樱桃番茄进行处理.研究对其采后腐烂的影响。试验结果表明,38℃加热处理能够显著地抑制3种不同的有害真菌(灰葡萄孢菌、链格孢菌和黑根霉菌)菌丝体的生长,说明加热处理和季也蒙毕赤酵母处理均能够减少由上述3种有害真菌导致的腐烂。  相似文献   
34.
The genus Corchorus includes nutrient-rich indigenous leafy vegetables often grown or harvested in the wild in Africa. It has potential to contribute to food security, but there is need to improve it as a crop through plant breeding. However, not much is known about the genetic variability among Corchorus species. The aim of this study was thus to characterise the available germplasm of Corchorus accessions and investigate heritability of their agro-morphological traits. Eleven Corchorus accessions (4 South African and 7 from the World Vegetable Center) were evaluated in a field study at Roodeplaat, South Africa, for their morpho-agronomic traits using a randomised complete block design with three replications across two seasons (2015/2016 and 2016/2017). Data were subjected to ANOVA, principal component analysis and cluster analysis. Broad sense heritability, genetic advance, genetic parameters and correlations were determined among the accessions and traits. The Corchorus accessions showed significant (P < .05) differences in all the quantitative traits evaluated. The data showed significant variability among the studied Corchorus accessions in their agro-morphological traits for exploitation in future breeding programmes that in turn can contribute to the improvement of this crop.  相似文献   
35.
CANINE HEMANGIOPERICYTOMA   总被引:1,自引:0,他引:1  
The records of 22 dogs treated with postoperative radiation therapy for hemangiopericytomas were retrospectively reviewed to determine which factors affected survival. Based on analysis with the logrank statistics, two factors were significant (p≤5.05): limb (front vs hind) and portal size. Tumor-free interval ranged from 1.5–55 months, with 40.9% of the dogs tumor-free at 24 months. Survival ranged from 2.5–55 months, with 40% of the dogs dead due to tumor recurrence or tumor-related causes.  相似文献   
36.
Recommendations are presented for standardized imaging planes and display conventions for two-dimensional echocardiography in the dog and cat. Three transducer locations ("windows") provide access to consistent imaging planes: the right parasternal location, the left caudal (apical) parasternal location, and the left cranial parasternal location. Recommendations for image display orientations are very similar to those for comparable human cardiac images, with the heart base or cranial aspect of the heart displayed to the examiner's right on the video display. From the right parasternal location, standard views include a long-axis four-chamber view and a long-axis left ventricular outflow view, and short-axis views at the levels of the left ventricular apex, papillary muscles, chordae tendineae, mitral valve, aortic valve, and pulmonary arteries. From the left caudal (apical) location, standard views include long-axis two-chamber and four-chamber views. From the left cranial parasternal location, standard views include a long-axis view of the left ventricular outflow tract and ascending aorta (with variations to image the right atrium and tricuspid valve, and the pulmonary valve and pulmonary artery), and a short-axis view of the aortic root encircled by the right heart. These images are presented by means of idealized line drawings. Adoption of these standards should facilitate consistent performance, recording, teaching, and communicating results of studies obtained by two-dimensional echocardiography. (Journal of Veterinary Internal Medicine 1993; 7:247–252. Copyright © 1993 by the American College of Veterinary Internal Medicine.)  相似文献   
37.
Recommendations are presented for standardized imaging planes and display conventions for two-dimensional echocardiography in the dog and cat. Three transducer locations (“windows”) provide access to consistent imaging planes: the right parasternal location, the left caudal (apical) parasternal location, and the left cranial parasternal location. Recommendations for image display orientations are very similar to those for comparable human cardiac images, with the heart base or cranial aspect of the heart displayed to the examiner's right on the video display. From the right parasternal location, standard views include a long-axis four-chamber view and a long-axis left ventricular outflow view, and short-axis views at the levels of the left ventricular apex, papillary muscles, chordae tendineae, mitral valve, aortic valve, and pulmonary arteries. From the left caudal (apical) location, standard views include long-axis two-chamber and four-chamber views. From the left cranial parasternal location, standard views include a long-axis view of the left ventricular outflow tract and ascending aorta (with variations to image the right atrium and tricuspid valve, and the pulmonary valve and pulmonary artery), and a short-axis view of the aortic root encircled by the right heart. These images are presented by means of idealized line drawings. Adoption of these standards should facilitate consistent performance, recording, teaching, and communicating results of studies obtained by two-dimensional echocardiography.  相似文献   
38.
Thoroughbred mares treated for signs of placentitis are potentially costly to farms and owners. Although these treatments often are effective, the resulting foal may require expensive aftercare. The current study investigated the future racing performance of foals from mares treated for clinical and subclinical signs of placentitis compared with matched control mares that had no signs of placentitis producing foals on the same farms. In total, 190 horses born from mares with suspected placentitis met the criteria for analysis and were matched with 190 horses born on the same farm. Mare data and percentage of stakes winners in each group were analyzed with Student t test. Analysis between pairs of horses was done using a paired t test for number of starts, wins, places, shows, and amount earned. Significance was set at a P value of <.05. Mares with suspected placentitis were slightly older than control mares, had slightly shorter lengths of gestation, and had a longer interval to subsequent pregnancy than control mares (P < .05). Horses out of suspected placentitis mares that were racing as 2 year olds in the study had no difference in starts, wins, places, shows, and percentages of black-type race winners; however, this group earned more than their matched control pairs (P < .05). Older horses (3 year olds) out of suspected placentitis mares had no differences in number of starts, wins, places, shows or amount earned; however, the matched control older horses had more black-type race winners (P < .05). The information from this study may aid owners when making decisions about treatment options.  相似文献   
39.
Blood sample collection from the caudal vena cava at the site of uterine–ovarian drainage provides a more exact evaluation of the concentration and pattern of secretion of uterine or ovarian secreted products for studies of reproductive processes in cyclic and pregnant cattle compared with samples collected from general circulation. This paper describes a thorough and updated procedure for cannulating the coccygeal vein into the caudal vena cava for the collection of serial blood samples at or near the site of uterine–ovarian drainage. Concentrations of progesterone were quantified in cows of different reproductive tract sizes with an active corpus luteum to assess the distance for proper catheter placement compared with circulating concentrations collected from the jugular vein. This procedure has a low risk for side effects, can be used effectively in pregnant animals with no major consequence to the viability of the pregnancy, and provides means for frequent collections up to 12 d.  相似文献   
40.
Eighty normal dogs of four morphologically disparate breeds (Pembroke Welsh Corgi, Miniature Poodle, Afghan Hound, Golden Retriever) (twenty of each breed), were studied by echocardiography to determine the importance of breed and weight in establishing normal echocardiographic reference ranges. Echocardiographic measurements included left-ventricular chamber dimension at systole and end-diastole, right-ventricular chamber dimension at end-diastole, interventricular septal thickness at systole and end-diastole, left-ventricular free wall thickness at systole and end-diastole, E-point septal separation, aortic root dimension at end-diastole, left atrial dimension, and fractional shortening. Analyses of covariance indicated that for all measurements except right-ventricular chamber dimension, the means were significantly different among breeds, after the differences in weight were taken into account. Echocardiographic measurements are variable even within the same breed. Breed must be considered in establishing echocardiographic measurement reference ranges. Echocardiographic values for each breed are presented.  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