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   2513626篇
  免费   220883篇
  国内免费   12638篇
耳鼻咽喉   34350篇
儿科学   78713篇
妇产科学   62428篇
基础医学   425153篇
口腔科学   66225篇
临床医学   223948篇
内科学   421309篇
皮肤病学   74919篇
神经病学   223295篇
特种医学   98863篇
外国民族医学   26篇
外科学   398022篇
综合类   81777篇
现状与发展   23篇
一般理论   2001篇
预防医学   216167篇
眼科学   56009篇
药学   167216篇
  22篇
中国医学   7803篇
肿瘤学   108878篇
  2022年   22531篇
  2021年   54104篇
  2020年   34532篇
  2019年   57388篇
  2018年   68631篇
  2017年   52139篇
  2016年   57395篇
  2015年   72299篇
  2014年   106257篇
  2013年   171153篇
  2012年   65813篇
  2011年   61434篇
  2010年   108887篇
  2009年   115657篇
  2008年   49238篇
  2007年   48581篇
  2006年   61050篇
  2005年   56916篇
  2004年   59509篇
  2003年   51124篇
  2002年   41324篇
  2001年   52210篇
  2000年   43253篇
  1999年   53676篇
  1998年   59659篇
  1997年   59002篇
  1996年   56595篇
  1995年   52225篇
  1994年   46407篇
  1993年   43548篇
  1992年   34507篇
  1991年   32130篇
  1990年   29547篇
  1989年   30096篇
  1988年   28188篇
  1987年   27458篇
  1986年   26162篇
  1985年   27676篇
  1984年   30732篇
  1983年   29717篇
  1982年   35608篇
  1981年   34121篇
  1980年   32257篇
  1979年   22998篇
  1978年   24467篇
  1977年   23554篇
  1976年   21306篇
  1975年   18824篇
  1974年   17328篇
  1973年   16577篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的 观察改良睑黄色瘤切除术的应用效果。方法 选择病灶〈10mm以下的瘤体为手术观察对象,共22例(38眼)。按超皮损病灶边界1mm设计切口缘,梭形切除病灶,深达真皮层,在显微镜下清除皮下组织及切缘脂肪组织,松解切口边缘皮肤,连续皮内缝合切口。另外,酌情行上睑松弛矫治术。结果 失访2例(2眼),随访20例(36眼)6—12个月,未见黄色瘤复发,切口平整,痕迹隐约。结论 采用改良睑黄色瘤切除术更会增强眼睑形态美感。  相似文献   
992.
Background The objective was to measure the plasma concentrations of thymulin and nerve growth factor (NGF) in a group of patients with primary open angle glaucoma (POAG) and compare them with age- and sex-matched normal controls.Methods Twenty-eight patients newly diagnosed with POAG who were not undergoing treatment were compared with the same number of age- and sex-matched healthy controls. Blood samples were drawn into heparinized tubes and plasma samples were collected for the determination of the concentrations of thymulin and NGF, using specific enzyme-linked immunosorbent assay (ELISA). The Student’s t test was used to perform the necessary statistical analysis of the results.Results Seventeen women and 11 men were enrolled in each of the two groups (study and control), with a mean age of 63.7 (SD 10.3) years in the former and 63.3 (SD 9.6) years in the latter. There was a highly significant (p<0.001) elevation in the thymulin levels in POAG patients compared with the control group. However, no significant difference was observed when comparing the plasma NGF levels.Conclusion This is the first report to measure plasma thymulin levels in glaucoma patients. The significant results point the possible role of this immunomodulator in the pathogenesis of primary open angle glaucoma. The potential role of NGF seems to be less likely. These findings warrant further investigation.  相似文献   
993.
目的探讨脉冲微波治疗前列腺炎的效果。方法收治前列腺炎病人532例。用南京亿高ECO—100型电脑微波前列腺炎治疗仪,经肛门途径发射脉冲微波,前列腺部位温度控制在41℃~42℃,每次持续45~60min,共七次。以显效、有效为判断疗效标准。结果17~25岁组显效47.93%,有效52.07%,26~45岁组显效52.06%,有效47.94%,两组有效率100%。结论脉冲微波经肛门途径治疗前列腺炎效果明显,有推广价值。  相似文献   
994.
Toby O. Smith   《Physiotherapy》2006,92(3):135-145
Pretibial lacerations and lower limb wounds are referred to plastic surgery teams for split skin graft surgery. Traditionally, these patients have been immobilised on bedrest following surgery. More recently, patients have commenced ambulation earlier to avoid medical complications and facilitate discharge. The objective of this literature review was to determine when such patients should begin walking. A literature search was undertaken using the electronic databases AMED, Cinahl, Embase, Medline (via Ovid), PEDro and Pubmed. Clinical trials using human subjects, written in English, were included. Seventeen (of 1137) papers met the inclusion criteria and were reviewed. The literature suggested that patients should begin walking immediately or at the earliest possible opportunity after lower limb skin graft surgery. Although the literature advocated early ambulation, the evidence base presented with a number of recurrent methodological limitations, including small sample sizes, lack of a control sample, and limited follow-up. Accordingly, further research employing large, well-designed, randomised controlled trials is recommended. It will then be possible to understand with greater certainty when patients should begin walking after lower extremity split skin graft surgery.  相似文献   
995.
996.
997.
998.
BACKGROUND: Three dimensional skin equivalents are widely used in dermatopharmacological and toxicological studies and as autologous transplants in wound healing. In pharmacology, there is tremendous need for monitoring the response of engineered skin equivalents to external treatment. Transplantation of skin equivalents for wound healing requires careful verification of their quality prior to transplantation. Optical coherence tomography (OCT) is a non-contact, non-destructive imaging technique for living tissues offering the potential to fulfill these needs. This work presents an analysis of OCT for high-resolution monitoring of skin equivalents at different stages during the culture process. METHODS: We developed a high-resolution OCT imaging setup based on a commercially available OCT system. A broadband femtosecond laser light source replaces the original superluminescence diode. Tomograms of living skin equivalents were recorded with an axial resolution of 3 mum and correlated with histology and immunofluorescence images. Comparison with standard low-resolution OCT is presented to emphasize the advantages of high-resolution OCT for this application. RESULTS: OCT is particularly able to distinguish between different layers of skin equivalents including stratum corneum, epidermal and dermal layer as well as the basement membrane zone. The high-resolution OCT scans correlate closely with two key benchmarks, histology and immunofluorescence imaging. CONCLUSIONS: This study clearly demonstrates the benefits of high-resolution OCT for identifying living tissue structure and morphology. Compared with the current gold standard histology, OCT offers non-destructive tissue imaging, enabling high-resolution evaluation of living tissue morphology and structure as it evolves.  相似文献   
999.
    
Ohne Zusammenfassung
Endpunkt- und Verlaufsmessungen bei entzündlichen rheumatischen Erkrankungen in Studien und Praxis
  相似文献   
1000.
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