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   51351篇
  免费   4270篇
  国内免费   122篇
耳鼻咽喉   425篇
儿科学   2068篇
妇产科学   1442篇
基础医学   7324篇
口腔科学   1036篇
临床医学   6761篇
内科学   10060篇
皮肤病学   991篇
神经病学   5199篇
特种医学   1175篇
外科学   5178篇
综合类   442篇
一般理论   64篇
预防医学   6041篇
眼科学   782篇
药学   2899篇
  3篇
中国医学   83篇
肿瘤学   3770篇
  2023年   431篇
  2022年   268篇
  2021年   1400篇
  2020年   1021篇
  2019年   1527篇
  2018年   1669篇
  2017年   1318篇
  2016年   1449篇
  2015年   1511篇
  2014年   1914篇
  2013年   2798篇
  2012年   3915篇
  2011年   4066篇
  2010年   2250篇
  2009年   1989篇
  2008年   3288篇
  2007年   3416篇
  2006年   3306篇
  2005年   3134篇
  2004年   3004篇
  2003年   2792篇
  2002年   2509篇
  2001年   521篇
  2000年   463篇
  1999年   459篇
  1998年   571篇
  1997年   435篇
  1996年   377篇
  1995年   377篇
  1994年   295篇
  1993年   274篇
  1992年   273篇
  1991年   239篇
  1990年   211篇
  1989年   166篇
  1988年   165篇
  1987年   135篇
  1986年   135篇
  1985年   138篇
  1984年   133篇
  1983年   125篇
  1982年   144篇
  1981年   141篇
  1980年   114篇
  1979年   78篇
  1978年   75篇
  1977年   60篇
  1976年   55篇
  1973年   63篇
  1972年   55篇
排序方式: 共有10000条查询结果,搜索用时 557 毫秒
1.
2.

Microdeletions encompassing 14q11.2 locus, involving SUPT16H and CHD8, were shown to cause developmental delay, intellectual disability, autism spectrum disorders and macrocephaly. Variations leading to CHD8 haploinsufficiency or loss of function were also shown to lead to a similar phenotype. Recently, a 14q11.2 microduplication syndrome, encompassing CHD8 and SUPT16H, has been described, highlighting the importance of a tight control of at least CHD8 gene-dosage for a normal development. There have been only a few reports of 14q11.2 microduplications. Patients showed variable neurodevelopmental issues of variable severity. Breakpoints of the microduplications were non-recurrent, making interpretation of the CNV and determination of their clinical relevance difficult. Here, we report on two patients with 14q11.2 microduplication encompassing CHD8 and SUPT16H, one of whom had normal intelligence. Review of previous reports describing patients with comparable microduplications allowed for a more precise delineation of the condition and widening of the phenotypic spectrum.

  相似文献   
3.
4.
Purpose: Family psychosocial risk in pediatric oncology can be assessed using the Psychosocial Assessment Tool (PAT), a brief parent report screener based on the Pediatric Psychosocial Preventative Health Model (PPPHM; universal, targeted, and clinical). However, little is known about risk over the course of treatment and its association with medical and psychosocial healthcare utilization. Methods: Primary caregivers of children with cancer participated in this prospective multisite investigation, completing the PAT at diagnosis (T1; n = 396) and 6 months later (T2; n = 304). Healthcare utilization data were extracted from electronic health records. Results: The distribution of PPPHM risk levels at T1 and T2 was highly consistent for the samples. Two‐thirds of families remained at the same level of risk, 18% decreased and 16% increased risk level. Risk was not related to sociodemographic or treatment variables. The PAT risk score correlated with psychosocial contacts over the 6‐month period. Conclusions: Although the majority of families reported universal (low) risk on the PAT and were stable in their risk level over 6 months, reassessing risk is helpful in identifying those families who report higher level of risk during treatment than at diagnosis. PAT scores were related to psychosocial services that are provided to most but not all families and could be tailored more specifically to match risk and delivery of evidence‐based care.  相似文献   
5.
6.
7.
In the current immunosuppressive therapy era, vessel thrombosis is the most common cause of early graft loss after renal transplantation. The prevalence of IgA anti–β2-glycoprotein I antibodies (IgA-aB2GPI-ab) in patients on dialysis is elevated (>30%), and these antibodies correlate with mortality and cardiovascular morbidity. To evaluate the effect of IgA-aB2GPI-ab in patients with transplants, we followed all patients transplanted from 2000 to 2002 in the Hospital 12 de Octubre prospectively for 10 years. Presence of IgA-aB2GPI-ab in pretransplant serum was examined retrospectively. Of 269 patients, 89 patients were positive for IgA-aB2GPI-ab (33%; group 1), and the remaining patients were negative (67%; group 2). Graft loss at 6 months post-transplant was significantly higher in group 1 (10 of 89 versus 3 of 180 patients in group 2; P=0.002). The most frequent cause of graft loss was thrombosis of the vessels, which was observed only in group 1 (8 of 10 versus 0 of 3 patients in group 2; P=0.04). Multivariate analysis showed that the presence of IgA-aB2GPI-ab was an independent risk factor for early graft loss (P=0.04) and delayed graft function (P=0.04). There were no significant differences regarding patient survival between the two groups. Graft survival was similar in both groups after 6 months. In conclusion, patients with pretransplant IgA-aB2GPI-ab have a high risk of early graft loss caused by thrombosis and a high risk of delayed graft function. Therefore, pretransplant IgA-aB2GPI-ab may have a detrimental effect on early clinical outcomes after renal transplantation.  相似文献   
8.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  相似文献   
9.
10.
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