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   441篇
  免费   13篇
  国内免费   22篇
耳鼻咽喉   2篇
儿科学   37篇
妇产科学   2篇
基础医学   19篇
口腔科学   9篇
临床医学   49篇
内科学   55篇
皮肤病学   8篇
神经病学   6篇
特种医学   122篇
外科学   29篇
综合类   29篇
预防医学   20篇
眼科学   30篇
药学   29篇
中国医学   3篇
肿瘤学   27篇
  2023年   1篇
  2022年   2篇
  2020年   2篇
  2019年   2篇
  2018年   6篇
  2017年   2篇
  2016年   2篇
  2015年   8篇
  2014年   8篇
  2013年   13篇
  2012年   6篇
  2011年   10篇
  2010年   15篇
  2009年   12篇
  2008年   11篇
  2007年   24篇
  2006年   29篇
  2005年   7篇
  2004年   15篇
  2003年   5篇
  2002年   7篇
  2001年   16篇
  2000年   8篇
  1999年   9篇
  1998年   33篇
  1997年   22篇
  1996年   26篇
  1995年   22篇
  1994年   19篇
  1993年   22篇
  1992年   6篇
  1991年   4篇
  1990年   9篇
  1989年   5篇
  1988年   8篇
  1987年   5篇
  1986年   11篇
  1985年   8篇
  1984年   7篇
  1983年   6篇
  1982年   7篇
  1981年   7篇
  1980年   13篇
  1979年   3篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   1篇
排序方式: 共有476条查询结果,搜索用时 0 毫秒
471.
472.
Ilex paraguariensis St Hilaire (Aquifoliaceae) is a plant widely cultivated in South America and with various reputed medicinal properties that can be attributed to phenolic constituents of the leaves: caffeine, theophylline and theobromine, besides the flavonoids, quercetin and rutin. This study examined the antiparkinsonian activity of the hydroalcohol extract of Ilex paraguariensis in models of protection against cerebral injury induced by MPTP and reversal of the catatonia induced by reserpine in mice. The hydroalcohol extract prevented MPTP-induced hypolocomotion at doses of 250 and 500 mg/kg at the all time points observed and also prevented the reserpine-induced catalepsy at the same doses. The extract potentiated the effect of apomorphine in preventing catatonia, suggesting a non-dopaminergic activity, probably through antagonism of adenosine. In biochemical studies the hydroalcohol extract caused a significant decrease in the NO levels, exhibited a DPPH-scavenging ability and was effective in preventing the oxidation of deoxyribose. The results obtained suggest that the hydroalcohol extract of Ilex paraguariensis may have an antiparkinsonian profile in animal models, probably through its antioxidant activity and antagonist action on adenosine A(2A) receptors.  相似文献   
473.
We have characterized the earliest antigen-specific Th cells in murine mesenteric lymph nodes (MLN), following oral immunization with the hen egg lysozyme (HEL) as antigen and cholera toxin (CT) as adjuvant. We did this by analyzing in vitro proliferation and cytokine production in response to HEL by the MLN T cells. MLN cells taken 5 days after a single oral immunization with HEL and CT provided the earliest source of proliferating HEL-specific T cells. This proliferation was completely inhibited by anti-IL-2, but not inhibited by anti-IL-4 antibody. IL-2 protein was detected in culture supernatants but not IL- 4 using ELISA or bioassays. IL-4 mRNA was not found in responding cells using RT-PCR. Some of the day 5 MLN cultures produced IFN-gamma in response to HEL, but isolated T cells from the same MLN did not. Exogenous IL-4 alone did not stimulate day 5 MLN T cells, but IL-4 did synergize with HEL to induce a large proliferative response. The data indicate that the HEL-specific CD4 T cell pool in MLN 5 days after oral immunization is composed of undifferentiated precursor Th cells. These cells have the potential for IL-2 production and IL-4R expression upon re-stimulation in vitro.   相似文献   
474.

Background

To evaluate and compare efficacy and outcome after single site phacotrabeculectomy and conventional combined surgery in cases of coexisting primary open angle glaucoma and cataract.

Methods

This prospective study on fifty patients of concurrent primary open angle glaucoma and cataract, who had undergone combined surgery as single site phacotrabeculectomy or conventional single site trabeculectomy with extracapsular lens extraction with IOL implantation in 25 cases each. Evaluation was based on operative and postoperative complications, control of IOP and visual outcome. The follow up period ranged between twelve months to eighteen months.

Results

The mean medically controlled preoperative intraocular pressure was 22 mm of Hg (Range 18 to 35 mm of Hg) by applanation method of tonometry. The range of postoperative intra-ocular pressure after one year was 11 to 22 mm of Hg in first and 14 to 26 mm Hg in second group. Failure to maintain optimum postoperative IOP without Beta-blocker was more frequent after conventional combined procedure. There was no significant difference in incidence and pattern of postoperative complications.

Conclusion

Phacotrabeculectomy provides effective and sustained visual recovery and adequate control of intraocular pressure as compare to conventional combined procedure.Key Words: Phacotrabeculectomy, Comparison with conventional combined procedure  相似文献   
475.

Background

Evaluation of penetrating keratoplasty in cases of pseudophakic bullous keratopathy with AC/PC IOL exchange.

Methods

This retrospective study included 120 cases of pseudophakic bullous keratopathy managed over 9 years at three tertiary care eye centres followed up for 4 years. Cases were taken up for penetrating keratoplasty along within adjuvant procedures like IOL explantation and Secondary Posterior Chamber IOL implantation over the frill of posterior capsule.

Results

Lens exchange with Penetrating Keratoplasty (PK) was done in 93 and PK without lens exchange in 27 cases. 25% required systemic steroids for 2-3 weeks. Re-grafting was performed in 5% and 85% attained moderate visual acuity.

Conclusion

Intra ocular lens exchange and Posterior chamber IOL are suitable for penetrating keratoplasty in terms of optical clarity, graft survival and visual outcome.Key Words: PBK, IOL exchange (AC/PC)  相似文献   
476.
30 cases of open angle glaucoma with cataract who underwent phacoemulsification, PMMA phaco profile IOL implantation and trabeculectomy through same incision were critically evaluated. The mean controlled, preoperative intra ocular pressure was 20 mm of Hg (range 18 to 35 mm of Hg) by aplanation method. Mean post operative pressure after 12 months was 13 mm of Hg (range 11 to 22 mm of Hg) intra operative hyphaema, post operative uveitis were noted problems. Periodic, post operative optic disc and field evaluation remained static in 66% cases. Visual acuity of 6/12 or better was achieved in 60% cases. Failure to restore glaucoma control without medication was seen in 13.3% cases after 9–12 months. The combined phacotrabeculectomy is an effective single step technique of managing concurrent glaucoma with cataract.Key words: Single incision, Phacotrabeculectomy  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