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   2018篇
  免费   121篇
  国内免费   140篇
耳鼻咽喉   44篇
儿科学   60篇
妇产科学   14篇
基础医学   275篇
口腔科学   101篇
临床医学   227篇
内科学   459篇
皮肤病学   36篇
神经病学   64篇
特种医学   159篇
外科学   193篇
综合类   48篇
预防医学   51篇
眼科学   176篇
药学   221篇
中国医学   27篇
肿瘤学   124篇
  2023年   15篇
  2022年   30篇
  2021年   58篇
  2020年   29篇
  2019年   48篇
  2018年   53篇
  2017年   44篇
  2016年   52篇
  2015年   84篇
  2014年   98篇
  2013年   132篇
  2012年   139篇
  2011年   147篇
  2010年   106篇
  2009年   113篇
  2008年   105篇
  2007年   150篇
  2006年   103篇
  2005年   71篇
  2004年   85篇
  2003年   54篇
  2002年   61篇
  2001年   31篇
  2000年   32篇
  1999年   30篇
  1998年   48篇
  1997年   37篇
  1996年   37篇
  1995年   25篇
  1994年   27篇
  1993年   18篇
  1992年   11篇
  1991年   11篇
  1990年   17篇
  1989年   21篇
  1988年   28篇
  1987年   14篇
  1986年   8篇
  1985年   9篇
  1983年   5篇
  1982年   5篇
  1981年   9篇
  1980年   8篇
  1977年   5篇
  1976年   5篇
  1975年   8篇
  1962年   4篇
  1961年   4篇
  1958年   14篇
  1955年   4篇
排序方式: 共有2279条查询结果,搜索用时 15 毫秒
51.
Although diagnosis of Plasmodium vivax malaria has been difficult when it is present at a low parasite density, it was recently revealed that an antibody assay was a good method of screening for malaria in blood banks. However, the use of this method for the diagnosis of malaria is limited due to the persistence of specific immunoglobulin (Ig) G. Therefore, we evaluated specific IgM antibody responses against the C-terminal region of the merozoite surface protein 1 of P. vivax (PvMSP1c) in sera obtained from patients with vivax malaria using various assays. The IgM capture enzyme-linked immunosorbent assay showed good sensitivity (97.7%; 308/315) and specificity (99.1%, 446/450). In addition, the results of this assay were not related to parasite density, and a high reactivity was observed when there was a low level of parasitemia. Furthermore, we found that patients with cases of malaria that had relapsed still had the IgM titers against PvMSP1c. Therefore, the use of IgM ELISA for the detection of specific IgM that was not involved in memorial immune activity could be an alternative tool for the diagnosis of malaria and blood screening, even in areas in which malaria is endemic.  相似文献   
52.
53.
54.
55.
56.
In this 2-part overview, the current status of phakic intraocular lens (pIOL) surgery to correct refractive errors is reviewed. Three types of pIOLs, categorized by their intraocular position, are included: angle-supported anterior chamber, iris-fixated anterior chamber, and posterior chamber (usually fixated in the ciliary sulcus). Part 1 reviews the main models of each pIOL type, the selection criteria, and the surgical techniques, with emphasis on currently available pIOLs. Bioptics, adjustable refractive surgery, and enhancements are addressed, and applications of the new anterior segment imaging techniques are reviewed.  相似文献   
57.
OBJECTIVE: To describe the design and operations of the South Carolina Traumatic Brain Injury (TBI) Follow-up Registry. DESIGN: Statewide prospective cohort study. SETTING: State of South Carolina. PARTICIPANTS: 2118 persons discharged from acute care hospitals after experiencing TBI. INTERVENTION: Telephone interviews. MAIN OUTCOME MEASURES: Service needs, alcohol and drug use, psychosocial health, health-related quality of life, functional status, symptoms of TBI, employment, global life satisfaction, and death. RESULTS: Selected initial and 1-year follow-up findings concerning demographic, insurance status, income, and employment factors. CONCLUSIONS: Population-based outcome studies that describe longer term problems associated with TBI, the need for services, and estimated disability could be useful to inform public policy.  相似文献   
58.
Radiosensitization of tumor cells by modulation of ATM kinase   总被引:2,自引:0,他引:2  
PURPOSE: To elucidate the relationship between the radiation-induced activation of ataxia telangiectasia mutated (ATM) kinase, G2 arrest and the caffeine-induced radiosensitization. METHOD: RKO cells (human colorectal cancer cells) and ATM kinase over-expressing RKO/ATM cells were used. The cellular radiosensitivity was determined with clonogenic survival assay and the cell cycle progression, including G2 arrest, was studied with flow cytometry. The activity of ATM kinase, check point 2 (Chk2) kinase and cycline B1/cell division cycle 2 (Cdc2) kinase was investigated. The radiosensitivity of RKO xenografts grown in nude mice was studied. RESULTS: RKO/ATM cells were radioresistant as compared with RKO cells. There was a greater increase in ATM kinase activity and G2 arrest in RKO/ATM cells than in RKO cells. Caffeine also sensitized both RKO cells and RKO/ATM cells to radiation. The caffeine treatment suppressed the radiation-induced activation of ATM kinase, suppressed the activation of Chk2 kinase and inhibited the accumulation of cells in G2 phase. The activity of cycline B1/Cdc2 kinase increased earlier but decayed rapidly in the presence of caffeine. Caffeine enhanced radiation-induced growth delay of RKO xenografts. CONCLUSIONS: Caffeine inhibited the radiation-induced activation of ATM kinase, thereby preventing the accumulation of cells in G2 phase. Consequently, radiosensitivity of cells increased in the presence of caffeine both in vitro and in vivo.  相似文献   
59.
60.
PURPOSE: To compare quantitative polarimetric measurements in eyes with NTG and HTG using GDx-VCC. Both groups were matched by age and glaucoma stage based on the Humphrey visual field test. METHODS: We retrospectively reviewed the records of 146 patients who underwent Humphrey field analysis (HFA) and GDx-VCC. We compared outcomes of retinal nerve fiber layer (RNFL) parameters among the three groups by ANOVA and between each pair of groups using the Tukey-Kramer Post-Hoc test. We also evaluated the sensitivity and specificity of GDx-VCC in detecting glaucoma in each group. RESULTS: The mean age and HFA mean deviation (MD) were 55.6 +/- 9.5 years and -0.8 +/- 1.5 dB in 47 control patients, 59.4 +/- 9.0 years and -5.77 +/- 4.38 dB in 49 NTG patients, and 59.4 +/- 11.7 years and -8.09 +/- 6.77 dB in 51 HTG patients, respectively. All thickness parameters were lower in HTG patients compared to NTG patients, but there were no significant differences in ratio parameters between age-matched early HTG and NTG patients. The sensitivity of GDx-VCC was significantly higher in both early and total HTG patients compared to the respective groups of NTG patients. CONCLUSIONS: Compared to eyes with NTG, eyes with HTG showed reduced RNFL thickness and ratio parameters when patients were age and visual field matched. GDx-VCC appeared to be more sensitive in detecting RNFL damage in HTG patients.  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