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   284篇
  免费   13篇
  国内免费   2篇
林业   9篇
农学   5篇
基础科学   3篇
  37篇
综合类   37篇
农作物   10篇
水产渔业   15篇
畜牧兽医   165篇
园艺   7篇
植物保护   11篇
  2022年   3篇
  2021年   1篇
  2020年   10篇
  2019年   8篇
  2018年   6篇
  2017年   4篇
  2016年   2篇
  2015年   7篇
  2014年   7篇
  2013年   17篇
  2012年   22篇
  2011年   33篇
  2010年   12篇
  2009年   7篇
  2008年   24篇
  2007年   14篇
  2006年   25篇
  2005年   20篇
  2004年   16篇
  2003年   15篇
  2002年   13篇
  2001年   3篇
  2000年   1篇
  1999年   1篇
  1997年   3篇
  1996年   5篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1991年   2篇
  1988年   2篇
  1987年   1篇
  1985年   1篇
  1979年   1篇
  1975年   2篇
  1968年   1篇
  1966年   1篇
  1963年   1篇
  1962年   1篇
  1959年   1篇
  1958年   1篇
排序方式: 共有299条查询结果,搜索用时 15 毫秒
21.
22.
Arginine-utilising mycoplasmas isolated from the pneumonic lungs of 4 pigs were identified as M. hyosynoviae by their growth characteristics, biochemical activity and serological similarity to each other and to 2 type strains of M. hyosynoviae in growth inhibition tests. A purified culture of one M. hyosynoviae isolate was inoculated intravenously into 3 pigs which were killed 9 days later. Although arthritis was not observed clinically, M. hyosynoviae was isolated from 8 of 9 joints cultured, the tonsils and retropharyngeal lymph nodes of all 3 pigs and the lungs of 2 pigs. No histopathological changes were observed in synovial membranes of the joints cultured or lungs but severe depletion of lymphocytes in the cortex of lymphoid follicles in lymph nodes and tonsils was observed.  相似文献   
23.
Gunduz I  Buss GR  Chen P  Tolin SA 《Phytopathology》2004,94(7):687-692
ABSTRACT Resistance to Soybean mosaic virus (SMV) was identified in PI 88788 soybean, a germ plasm accession from China that is used widely as a source of resistance to soybean cyst nematode. Strains SMV-G1 through -G7 infected the inoculated leaves of PI 88788 but were not detected in upper, noninoculated trifoliolate leaves. Inheritance of resistance was determined by inoculating progenies of crosses of PI 88788 with susceptible cvs. Essex and Lee 68 with SMV strains G1 and G7. Allelomorphic relationships with known genes for resistance to SMV were tested in crosses with the resistant genotypes PI 96983, L29, and V94-5152, possessing Rsv1, Rsv3, and Rsv4 genes, respectively. Data analyses showed that resistance in PI 88788 to SMV-G1 is controlled by a single, partially dominant gene; however, to SMV-G7, the same gene was completely dominant. The PI 88788 gene was independent of the Rsv1 and Rsv3 loci, but allelic to Rsv4 in V94-5152. Expression of the Rsv4 gene in PI 88788 resulted in a reduced number of infection sites and restricted short- and long-distance movement of virus, rather than hypersensitivity. A unique late susceptible phenotype was strongly associated with heterozygosity. This gene has potential value for use in gene pyramiding to achieve resistance to several SMV strains, as well as for rate-reducing resistance.  相似文献   
24.
The responses of 15 cats with histologically (n=14) or cytologically (n=1) confirmed nasal squamous cell carcinoma treated with (90)Strontium plesiotherapy were reviewed retrospectively. Cats were treated such that a total dose of 50Gy was delivered at a depth of 2mm, administered in five fractions over a 10-day period. Of the cats, 11 were stage T(2), three were T(is) and one had only a cytological diagnosis precluding staging. Eleven of the cats achieved complete response (no visible lesion after 6-8 weeks) following the first cycle of therapy, and two cats with partial response achieved complete response with a second cycle of therapy. The remaining two cats achieved partial response following therapy, but further intervention was declined. Euthanasia was performed in these two cats because of progressive disease after 81 and 142 days. Of the 85% of cats that achieved a complete response, there was no recurrence of disease during a follow-up period of 134-2,043 days (median 652 days). In addition to prolonged disease-free survivals, (90)Strontium therapy produced excellent cosmetic results from the owners' perspective. These results demonstrate that superficial squamous cell carcinoma of the feline nasal planum responds excellently to (90)Strontium plesiotherapy, and this form of therapy may offer advantages over other alternatives currently available.  相似文献   
25.
CASE DESCRIPTION: A 5-year-old sexually intact male cockatiel was examined because of progressive dyspnea of 1 week's duration. CLINICAL FINDINGS: On auscultation of the lungs and air sacs, crackles were detected; the abdomen was distended and fluctuant on palpation. Eleven milliliters of clear yellow fluid was collected via abdominocentesis. Radiography (with and without contrast medium) and ultrasonography revealed a soft tissue mass in the caudoventral portion of the coelom. TREATMENT AND OUTCOME: Exploratory surgery of the coelomic cavity was performed and the neoplasm was excised. Histologic examination of the neoplasm was consistent with a high-grade pancreatic exocrine adenocarcinoma. Celecoxib, a cyclooxygenase (COX)-2 inhibitor, was administered for pain management and for potential antineoplastic activity. For 4.5 months after surgery, the bird had no recurrence of clinical signs; however, dyspnea recurred and during evaluation, the bird died. Necropsy findings indicated that the pancreatic adenocarcinoma had metastasized to surrounding tissues and vessels, which was not unexpected given the high grade assigned to the neoplasm during histologic analysis. CLINICAL RELEVANCE: Pancreatic neoplasms are associated with a poor prognosis, regardless of treatment modality. Celecoxib can be administered as palliative treatment to affected birds, but as with any nonsteroidal anti-inflammatory drug, COX-2 inhibitors should be used cautiously because they can adversely affect renal function by decreasing renal prostaglandin synthesis.  相似文献   
26.
The challenges of reusing mining and mineral-processing wastes   总被引:2,自引:0,他引:2  
Mining and mineral-processing wastes are one of the world's largest chronic waste concerns. Their reuse should be included in future sustainable development plans, but the potential impacts on a number of environmental processes are highly variable and must be thoroughly assessed. The chemical composition and geotechnical properties of the source rock determine which uses are most appropriate and whether reuse is economically feasible. If properly evaluated, mining waste can be reused to reextract minerals, provide additional fuel for power plants, supply construction materials, and repair surface and subsurface land structures altered by mining activities themselves.  相似文献   
27.
Objective-To evaluate whether dogs undergoing splenectomy had an increased risk of gastric dilatation-volvulus (GDV), compared with a control group of dogs undergoing enterotomy. Design-Retrospective case-control study. Animals-219 dogs that underwent splenectomy for reasons other than splenic torsion (splenectomy group; n = 172) or enterotomy (control group; 47) without concurrent gastropexy. Procedures-Medical records were reviewed for information on signalment, date of surgery, durations of surgery and anesthesia, reason for splenectomy, histopathologic findings (if applicable), whether gastropexy was performed, duration of follow-up, and date of death (if applicable). Follow-up information, including occurrence of GDV, was obtained via medical records review and a written client questionnaire. Results-Reasons for splenectomy included splenic neoplasia, nonneoplastic masses, infarction, traumatic injury, and adhesions to a gossypiboma. Incidence of GDV following surgery was not significantly different between dogs of the splenectomy (14/172 [8.1 %]) and control (3/47 [6.4%]) groups. Median time to GDV for the 17 affected dogs was 352 days (range, 12 to 2,368 days) after surgery. Among dogs that underwent splenectomy, sexually intact males had a significantly higher incidence of GDV (4/16) than did castrated males and sexually intact or spayed females (10/156). Incidence of GDV among sexually intact male dogs did not differ between groups. Conclusions and Clinical Relevance-Results did not support a recommendation for routine use of prophylactic gastropexy in dogs at the time of splenectomy. Other patient-specific risk factors should be assessed prior to recommending this procedure.  相似文献   
28.
Objective The aim of this study was to perform a retrospective review of parotid duct transposition (PDT) in the dog to determine the rate and nature of complications, the success and failure rates and to evaluate owner satisfaction. Methods Medical records of 56 dogs (92 eyes) that underwent PDT and subsequent follow‐up by a veterinary ophthalmologist were reviewed. Forty owners (40 dogs/66 eyes) were contacted by telephone and 37 owners (37 dogs/60 eyes) also completed a visual analog scale questionnaire. Statistical evaluation included Wilcoxon Signed Rank tests, one‐way analysis of variance and Kaplan–Meier survival analysis with Wilcoxon and Log‐rank tests. Results The mean follow‐up was 38.7 months (range 1–109 months). The surgical success rate was 92% (85/92 eyes). Total failures (8%, 7/92 eyes) were because of severe saliva intolerance (n = 5 eyes) and PDT failure (n = 2 eyes). The complication rate was 50% (46/92 eyes) of which 61% (28/46 eyes) were managed medically and 39% (18/46 eyes) required further surgery. Ninety percent (36/40) of owners indicated that they would proceed with surgery again. Statistically significant improvements in owner perception of ocular comfort, number of daily topical treatments, ocular wetness, and postoperative vision were identified. Conclusions This study shows that PDT is a successful procedure based on clinical findings and in terms of owner perception. It has also demonstrated that PDT improves ocular comfort and vision in medically refractive cases of keratoconjunctivitis sicca, and that a low level of on‐going management is required in 33% of cases.  相似文献   
29.
30.
Inflammatory colorectal polyps (ICRPs) in miniature dachshunds are recently recognized as a major cause of large bowel diarrhea in this dog breed in Japan. ICRPs are characterized by the formation of multiple small polyps and a space-occupying large polyp in the colorectal area, and are thought to be a novel form of inflammatory bowel disease (IBD). In humans, specific cytokine patterns attributed to T helper (Th)1, Th17 and regulatory T cells have important roles in the pathogenesis of IBD. Thus, the aim of the present study was to assess the gene expression of cytokines of T cell subsets in the colorectal mucosa from dogs with ICRPs. Colorectal mucosal specimens from 10 dogs with ICRPs and 14 control dogs were used in this study. Interferon (IFN)-γ, interleukin (IL)-4, IL-17A and IL-10 mRNA expression was assessed using quantitative real-time PCR. IL-17A mRNA expression was significantly increased in large polyps compared to small polyps and controls. IFN-γ and IL-10 mRNA expression in large polyps were significantly higher than in controls. There was no significant difference in IL-4 mRNA expression among the three groups. IL-17A is thought to play important roles in the pathogenesis of ICRPs. IL-10 up-regulation could oppose the proinflammatory function of IL-17A.  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