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   3117篇
  免费   123篇
  国内免费   12篇
耳鼻咽喉   10篇
儿科学   112篇
妇产科学   76篇
基础医学   535篇
口腔科学   59篇
临床医学   335篇
内科学   616篇
皮肤病学   46篇
神经病学   268篇
特种医学   50篇
外科学   246篇
综合类   13篇
预防医学   313篇
眼科学   18篇
药学   213篇
中国医学   4篇
肿瘤学   338篇
  2023年   25篇
  2022年   25篇
  2021年   54篇
  2020年   22篇
  2019年   45篇
  2018年   67篇
  2017年   44篇
  2016年   43篇
  2015年   54篇
  2014年   83篇
  2013年   105篇
  2012年   243篇
  2011年   269篇
  2010年   118篇
  2009年   117篇
  2008年   212篇
  2007年   234篇
  2006年   245篇
  2005年   218篇
  2004年   204篇
  2003年   200篇
  2002年   186篇
  2001年   19篇
  2000年   15篇
  1999年   28篇
  1998年   50篇
  1997年   32篇
  1996年   34篇
  1995年   32篇
  1994年   33篇
  1993年   25篇
  1992年   18篇
  1991年   18篇
  1990年   9篇
  1989年   13篇
  1988年   6篇
  1987年   10篇
  1986年   10篇
  1985年   7篇
  1984年   9篇
  1983年   11篇
  1982年   6篇
  1981年   7篇
  1980年   3篇
  1977年   6篇
  1976年   6篇
  1975年   5篇
  1973年   4篇
  1972年   4篇
  1971年   3篇
排序方式: 共有3252条查询结果,搜索用时 62 毫秒
71.

Objective

This study examined if ongoing support delivered by telephone following pulmonary rehabilitation (PR) assisted chronic obstructive pulmonary disease (COPD) patients to maintain health outcomes.

Methods

Phase one (n = 79) compared post-rehabilitation telephone-based support delivered by peers compared to usual care (UC). The second phase (n = 168) compared post-rehabilitation support from peer educators, respiratory therapists (RT), or UC. Primary outcome variables were St. George's Respiratory Questionnaire (SGRQ) total score and the six minute walk test (6MWT). Measures were obtained at baseline, immediately following PR, and six-months post PR.

Results

Six-month follow-up data for phase one was collected for 66 COPD patients (n = 35 peer support, n = 31 UC) and 142 for phase two (n = 42 peer support, n = 52 RT support, n = 48 UC). Per-protocol and intention to treat (ITT) analysis in both phases found no significant group by time differences for SGRQ or 6MWT.

Conclusion

Providing peer or RT support via telephone following PR was not more effective than UC for maintaining health outcomes.

Practice implications

There are concerns with using peers to provide ongoing support to COPD patients. Additionally, COPD patients require a higher level of care than telephone support can provide.  相似文献   
72.
73.
Mutational screening of the breast cancer susceptibility gene BRCA1 leads to the identification of numerous pathogenic variants such as frameshift and nonsense variants, as well as large genomic rearrangements. The screening moreover identifies a large number of variants, for example, missense, silent, and intron variants, which are classified as variants of unknown clinical significance owing to the lack of causal evidence. Variants of unknown clinical significance can potentially have an impact on splicing and therefore functional examinations are warranted to classify whether these variants are pathogenic or benign. Here we validate a mini-gene splicing assay by comparing the results of 24 variants with previously published data from RT-PCR analysis on RNA from blood samples/lymphoblastoid cell lines. The analysis showed an overall concordance of 100%. In addition, we investigated 13 BRCA1 variants of unknown clinical significance or putative variants affecting splicing by in silico analysis and mini-gene splicing assay. Both the in silico analysis and mini-gene splicing assay classified six BRCA1 variants as pathogenic (c.80+1G>A, c.132C>T (p.=), c.213−1G>A, c.670+1delG, c.4185+1G>A, and c.5075−1G>C), whereas six BRCA1 variants were classified as neutral (c.-19-22_-19-21dupAT, c.302−15C>G, c.547+14delG, c.4676−20A>G, c.4987−21G>T, and c.5278−14C>G) and one BRCA1 variant remained unclassified (c.670+16G>A). In conclusion, our study emphasizes that in silico analysis and mini-gene splicing assays are important for the classification of variants, especially if no RNA is available from the patient. This knowledge is crucial for proper genetic counseling of patients and their family members.  相似文献   
74.
This article describes the inter- and intra-familial phenotypic variability in four families with WNT10A mutations. Clinical characteristics of the patients range from mild to severe isolated tooth agenesis, over mild symptoms of ectodermal dysplasia, to more severe syndromic forms like odonto-onycho-dermal dysplasia (OODD) and Schöpf–Schulz–Passarge syndrome (SSPS). Recurrent WNT10A mutations were identified in all affected family members and the associated symptoms are presented with emphasis on the dentofacial phenotypes obtained with inter alia three-dimensional facial stereophotogrammetry. A comprehensive overview of the literature regarding WNT10A mutations, associated conditions and developmental defects is presented. We conclude that OODD and SSPS should be considered as variable expressions of the same WNT10A genotype. In all affected individuals, a dished-in facial appearance was observed which might be helpful in the clinical setting as a clue to the underlying genetic etiology.  相似文献   
75.
76.
Recent data suggest that oxidative injury may play an important role in demyelination and neurodegeneration in multiple sclerosis (MS). We compared the extent of oxidative injury in MS lesions with that in experimental models driven by different inflammatory mechanisms. It was only in a model of coronavirus-induced demyelinating encephalomyelitis that we detected an accumulation of oxidised phospholipids, which was comparable in extent to that in MS. In both, MS and coronavirus-induced encephalomyelitis, this was associated with massive microglial and macrophage activation, accompanied by the expression of the NADPH oxidase subunit p22phox but only sparse expression of inducible nitric oxide synthase (iNOS). Acute and chronic CD4+ T cell-mediated experimental autoimmune encephalomyelitis lesions showed transient expression of p22phox and iNOS associated with inflammation. Macrophages in chronic lesions of antibody-mediated demyelinating encephalomyelitis showed lysosomal activity but very little p22phox or iNOS expressions. Active inflammatory demyelinating lesions induced by CD8+ T cells or by innate immunity showed macrophage and microglial activation together with the expression of p22phox, but low or absent iNOS reactivity. We corroborated the differences between acute CD4+ T cell-mediated experimental autoimmune encephalomyelitis and acute MS lesions via gene expression studies. Furthermore, age-dependent iron accumulation and lesion-associated iron liberation, as occurring in the human brain, were only minor in rodent brains. Our study shows that oxidative injury and its triggering mechanisms diverge in different models of rodent central nervous system inflammation. The amplification of oxidative injury, which has been suggested in MS, is only reflected to a limited degree in the studied rodent models.  相似文献   
77.
78.
79.
80.
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