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   454篇
  免费   27篇
林业   26篇
农学   11篇
  34篇
综合类   16篇
农作物   16篇
水产渔业   51篇
畜牧兽医   291篇
园艺   4篇
植物保护   32篇
  2023年   1篇
  2022年   9篇
  2021年   18篇
  2020年   6篇
  2019年   6篇
  2018年   8篇
  2017年   12篇
  2016年   14篇
  2015年   19篇
  2014年   23篇
  2013年   29篇
  2012年   37篇
  2011年   36篇
  2010年   12篇
  2009年   16篇
  2008年   23篇
  2007年   25篇
  2006年   24篇
  2005年   23篇
  2004年   33篇
  2003年   50篇
  2002年   27篇
  2001年   8篇
  2000年   4篇
  1999年   1篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1992年   2篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1963年   1篇
排序方式: 共有481条查询结果,搜索用时 31 毫秒
31.
In the present study, we investigated plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) in seven Japanese macaques (Macaca fuscata) infected with Plasmodium coatneyi. Concentrations of sICAM-1 and sVCAM-1 were significantly elevated in the severe phase; the levels were maximally increased up to six times and three times those before infection, respectively. We subsequently examined kinetic profiles of sICAM-1 and sVCAM-1 concentration in plasma obtained from two infected monkeys. Both infected monkeys had markedly increased levels of these adhesion molecules when they exhibited severe clinical signs correlated with rapid increase in parasitemia. These results suggest that the elevation of levels of sICAM-1 and sVCAM-1 is a critical step in the pathogenesis of severe malaria in vivo.  相似文献   
32.
Epidemiological and bacteriological survey of buffalo mastitis in Nepal   总被引:2,自引:0,他引:2  
A total of 355 Murrah cross buffaloes, consisting of 23 subclinical and 332 clinical mastitis cases brought to the Veterinary Teaching Hospital, Chitwan, Nepal from 2002 to 2005, were analyzed to determine the organisms involved, the seasonal occurrence of mastitis, and antibiotic susceptibility of mastitis pathogens. Coagulase negative Staphylococci (CNS) such as Staphylococcus albus and S. epidermidis were the predominant organisms associated with subclinical cases, and CNS and Coliforms in clinical cases. The maximum number (16%) of clinical cases of mastitis were observed in the month of July, when temperature and humidity are highest. The incidence of clinical mastitis was higher in animals during 1st calving and during the 1st month of parturition. Resistance to antibiotics was determined for 55, 23 and 149 isolates of Staphylococcus spp., Streptococcus spp. and Coliforms, respectively. In vitro drug sensitivity testing revealed that enrofloxacin had the highest average sensitivity (91%) for all types of bacteria. The effectiveness of other drugs detected were gentamicin (87%), tetracycline (83%) and chloramphenicol (82%). The antibiogram showed that both gentamicin and enrofloxacin are slowly becoming resistant. Mastitis pathogens have developed resistance to ampicillin and penicillin.  相似文献   
33.
Medical records of dogs with colorectal polyps were retrospectively reviewed, and clinical presentation of inflammatory colorectal polyps in miniature dachshunds was evaluated. Of 33 dogs found to have colorectal polyps, miniature dachshunds were markedly over-represented with 16 dogs (48%), of which 12 (75%) were found to have inflammatory polyps. Multiple polyps localized between the rectum and the descending colon was the most common finding in miniature dachshunds with inflammatory polyps. Twenty dogs (80%) out of 25 miniature dachshunds with inflammatory colorectal polyps responded to immunosuppressive therapy using prednisolone and cyclosporine. The results of this study indicate that miniature dachshunds are predisposed to develop inflammatory colorectal multiple polyps, for which immunosuppressive therapy may be a treatment option.  相似文献   
34.
Intramammary infusion of Bifidobacterium breve (B. breve)-induced somatic cell (SC) counts, chemiluminescent response (CL), lactoferrin (LF) concentrations and mastitis-causing pathogens from quarters with subclinical mastitis were measured to evaluate innate immune response of mammary glands in dairy cows at 3 to 4 weeks before drying off. SC counts in 7 quarters of 7 control cows and 5 quarters of 6 cows with mastitis increased markedly on day 1 and SC values in control cows were significantly (P<0.05) increased and returned to pre-infusion levels on day 5 after B. breve-infusion. CL values in both groups increased markedly on day 1 and then decreased after B. breve-infusion; however, CL values in cows with mastitis did not return to normal levels on day 5 and at postpartum. The CL values were highly correlated with their SC counts in milk from both groups. LF concentrations increased toward day 3 after B. breve-infusion and were higher in cows with mastitis. B. breve-infusion eliminated 16.6% (1/6) of pathogens from 6 quarters with chronic subclinical mastitis. B. breve-induced SC responses in quarters from 3 cows with mastitis showed characteristic patterns of recovery, persistent and new infections. B. breve-induced SC counts in quarters from the cows in the pre-drying off were lower (25.7–70.6%) than those of the cows in mid-lactation. The intrinsic innate immune response in cows on pre-drying off may be decreased and appears to be insufficient to eliminate pathogens from mammary gland in the pre-drying off.  相似文献   
35.
36.
37.
Serum cytokine levels and their expression of mRNA on neutrophils from a bone marrow (BM) transplanted heifer with leukocyte adhesion deficiency were evaluated. The clinical condition of the affected heifer was relatively stable after BM-transplantation. Persistent hyper gamma-globulinemia and increased serum immunoglobulin G (IgG) concentrations were monitored longitudinally. The concentration of interleukin (IL)-1beta in serum from the affected heifer ranged from 15.8 to 321.7 ng/ml, and maximum concentration occurred at the time which coincided with peak IL-6. Serum levels of IL-6 ranged from 0.32 to 27.9 ng/m l, and they appeared to be associated with the increment of serum IgG in the affected heifer. mRNAs for IL-1beta, IL-6, IL-8 and granulocyte and macrophage colony stimulating factor (GM-CSF) were increased in neutrophils from the affected heifer compared to controls. Persistent hyper gamma-globulinemia of the affected heifer appeared to be associated with enhanced mRNA expression for IL-6 and its serum levels. These findings suggest that humoral immunity of the affected heifer is activated and the production of neutrophils appears to be enhanced under the incapability of beta(2) integrin-mediated functions of phagocytic cells.  相似文献   
38.
The present study was conducted to obtain new information on relationships among serum testosterone (T), estradiol-17 beta (E(2)), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) concentrations and histology of seminiferous tubules in captured common minke and Bryde's whales during the feeding season. Blood samples and testes were collected from common minke (n=39 for blood samples, n=15 for testes) and Bryde's (n=14 for blood samples, n=7 for testes) whales captured from May 2001 to August 2001 in the Western North Pacific. Serum T concentrations, in 35.9% of the common minke and 57.1% of Bryde's whales, were below the detection limit (< 2.5 pg/ml). There were no significant differences in the serum concentrations of E(2), FSH, and LH among immature, mature common minke and Bryde's whales except that LH levels of immature Bryde's whales was higher than those of common minke whales. In most seminiferous tubules of mature whales, only a single-layer of spermatogonia was observed. However, spermatozoa were observed in seminiferous tubules in 2/13 of mature common minke and 4/4 of mature Bryde's whales with the low or undetectable T levels. These results indicate that the low serum T concentrations reflect the inactivity of spermatogenesis in both baleen whales, and that it is not possible to assess gonadal activity in either common minke or Bryde's whales using serum sex hormone concentrations during the feeding season.  相似文献   
39.
Two cats showing chronic vomiting, diarrhea and weight loss were found to have leukocytosis with marked eosinophilia. Both cats were diagnosed with hypereosinophilic syndrome by the findings of increased eosinophils and their precursors in the bone marrow, eosinophilic infiltration into multiple organs, and exclusion of other causes for eosinophilia. Although cytoreductive chemotherapy with hydroxycarbamide and prednisolone was performed, these two cats died 48 days and 91 days after the initial presentation.  相似文献   
40.
High-mobility group box 1 (HMGB1), a nonhistone chromosomal protein, has recently been suggested as a late mediator of the inflammatory cascade. Blood HMGB1 levels are increased in a number of human diseases, and HMGB1 has been suggested to be a useful marker for disease severity and prognosis. The objective of this study was to assess the clinical usefulness of HMGB1 in dogs. Plasma HMGB1 levels, as well as C-reactive protein (CRP), a typical canine inflammatory marker, were measured in dogs with various diseases, especially systemic inflammatory response syndrome (SIRS), and dogs that had undergone surgery. HMGB1 gradually increased and attained a maximum level 72 hr after surgery, whereas CRP increased rapidly, peaking at 24 hr. Although both HMGB1 and CRP levels were significantly increased in dogs with various diseases compared with the control dogs, no correlation was found between the HMGB1 and CRP values. HMGB1 levels in the SIRS group were significantly elevated compared with those in the non-SIRS group. However, the increase in HMGB1 levels above the reference range was not indicative of SIRS. Instead, the presence of increased HMGB1 and CRP levels above the reference ranges significantly affects the poor outcome of SIRS. The present study indicates that HMGB1 is a novel canine inflammatory marker and is distinct from CRP. However, the additional clinical value of HMGB1 measurement remains unclear, and further studies are warranted.  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