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   15559篇
  免费   1136篇
  国内免费   21篇
耳鼻咽喉   95篇
儿科学   499篇
妇产科学   410篇
基础医学   1982篇
口腔科学   104篇
临床医学   2205篇
内科学   2863篇
皮肤病学   199篇
神经病学   1525篇
特种医学   340篇
外科学   1458篇
综合类   195篇
一般理论   18篇
预防医学   2233篇
眼科学   184篇
药学   1016篇
中国医学   15篇
肿瘤学   1375篇
  2023年   101篇
  2022年   160篇
  2021年   343篇
  2020年   228篇
  2019年   390篇
  2018年   415篇
  2017年   328篇
  2016年   357篇
  2015年   413篇
  2014年   535篇
  2013年   841篇
  2012年   1239篇
  2011年   1219篇
  2010年   644篇
  2009年   605篇
  2008年   967篇
  2007年   1144篇
  2006年   1074篇
  2005年   1055篇
  2004年   945篇
  2003年   922篇
  2002年   782篇
  2001年   127篇
  2000年   78篇
  1999年   133篇
  1998年   162篇
  1997年   129篇
  1996年   103篇
  1995年   115篇
  1994年   91篇
  1993年   84篇
  1992年   57篇
  1991年   51篇
  1990年   51篇
  1989年   43篇
  1988年   54篇
  1987年   51篇
  1986年   38篇
  1985年   34篇
  1984年   50篇
  1983年   41篇
  1982年   51篇
  1981年   45篇
  1980年   37篇
  1979年   30篇
  1978年   26篇
  1976年   33篇
  1970年   34篇
  1969年   30篇
  1968年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
On-line imaging of prostate markers can be used to compensate for errors in radiation delivery. This study assessed the patient acceptability and morbidity associated with the trans-perineal route of implantation. A minority experienced acute pain or bleeding. Placement was accurate in all but one subject. An operator related learning curve exists. Although this is an invasive procedure most patients found it acceptable. Implementation for routine clinical practice is feasible.  相似文献   
15.
16.
ABSTRACT: Background: The addition of supplementary prenatal support may improve the health and well‐being of high‐risk women and families. The objective of this randomized controlled trial was to examine the impact of supplementary prenatal care on resource use among a community‐based population of pregnant women. Methods: Pregnant women from three urban maternity clinics were randomized (a) to current standard of physician care, (b) to current standard of care plus consultation with a nurse, or (c) to (b) plus consultation with a home visitor. Participants were 1,352 women who received 3 telephone interviews. The primary outcome was resource use (e.g., attended prenatal classes, used nutritional counseling). Results: Overall, those in the nurse intervention group were more likely to attend an “Early Bird” prenatal class and parenting classes, and to use nutrition counseling and agencies that assist with child care. Women provided with extra nursing and home visitation supports were more likely to use a written resource guide, nutrition counseling, and agencies that assist with child care. Among women at higher risk (e.g., language barriers, young maternal age, low income), the nurse intervention significantly increased use of early prenatal classes, whereas the nurse and home visitor intervention significantly increased use of the written resource guide and nutrition counseling. The intervention substantially increased the amount of information received on numerous pregnancy‐related topics but had little impact on resource use for mental health and poverty‐related needs. Among those with added support, resource use among low‐risk women was generally greater than among high‐risk women. Conclusions: Additional support provided by nurses, or nurses and home visitors, can successfully address informational needs and increase the likelihood that women will use existing community‐based resources. This finding was true even for high‐risk women, although this intervention did not reduce the difference in resource use between high‐ and low‐risk women. (BIRTH 33:3 September 2006)  相似文献   
17.
Huntington's disease (HD) is a neurodegenerative disorder associated with expansion of CAG trinucleotide repeats in the huntingtin gene. A minimum of 36 CAG repeats is usually reported in patients with clinical features of HD; 30 to 35 repeats represent an intermediate range. Here we report a 65-year-old male with autopsy-proven HD and 29 CAG repeats.  相似文献   
18.
Parkin mutations account for the majority of familial and sporadic early onset Parkinson's disease (EOPD) cases with a known genetic association. More than 100 mutations have been described in the Parkin gene that includes homozygous, compound heterozygous, and single heterozygous mutations. We have designed a Parkin mutation genotyping array (gene chip) that includes published Parkin sequence variants and allows their simultaneous detection. The chip was validated by screening 85 PD cases and 47 controls previously tested for Parkin mutations. Similar genotyping microarrays have been developed for other genetically heterogeneous diseases including age-related macular degeneration. Here, we show the utility of a genotyping array for Parkinson's disease by analysis of 60 subjects from the Genetic Epidemiology of Parkinson Disease (GEPD) study that includes 15 early-onset PD case probands and 45 relatives.  相似文献   
19.
BACKGROUND: Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the relationships between circulating levels of the inflammatory markers interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-alpha) and total as well as site-specific cancer incidence. METHODS: Study subjects (n = 2,438) were older adults (ages 70-79 years) participating in the Health Aging and Body Composition study, who did not report a previous cancer diagnosis (except for nonmelanoma skin cancer) at baseline. Incident cancer events (n = 296) were ascertained during an average follow-up of 5.5 years. Inflammatory markers were measured in stored baseline fasting blood samples. RESULTS: The adjusted hazard ratios (95% confidence intervals) for incident cancer associated with a 1-unit increase on the natural log-scale were 1.13 (0.94-1.37), 1.25 (1.09-1.43), and 1.28 (0.96-1.70) for IL-6, CRP, and TNF-alpha, respectively. Markers were more strongly associated with cancer death: hazard ratios were 1.63 (1.19-2.23) for IL-6, 1.64 (1.20-2.24) for CRP, and 1.82 (1.14-2.92) for TNF-alpha. Although precision was low for site-specific analyses, our results suggest that all three markers were associated with lung cancer, that IL-6 and CRP were associated with colorectal cancer, and that CRP was associated with breast cancer. Prostate cancer was not associated with any of these markers. CONCLUSIONS: These findings suggest that (a) the associations between IL-6, CRP, and TNF-alpha and the risk of cancer may be site specific and (b) increased levels of inflammatory markers are more strongly associated with the risk of cancer death than cancer incidence.  相似文献   
20.
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