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   1174篇
  免费   70篇
  国内免费   37篇
耳鼻咽喉   16篇
儿科学   51篇
妇产科学   30篇
基础医学   120篇
口腔科学   32篇
临床医学   151篇
内科学   184篇
皮肤病学   14篇
神经病学   90篇
特种医学   38篇
外科学   376篇
综合类   21篇
预防医学   66篇
药学   42篇
中国医学   1篇
肿瘤学   49篇
  2023年   3篇
  2022年   13篇
  2021年   14篇
  2020年   14篇
  2019年   21篇
  2018年   33篇
  2017年   20篇
  2016年   18篇
  2015年   30篇
  2014年   60篇
  2013年   65篇
  2012年   75篇
  2011年   60篇
  2010年   35篇
  2009年   47篇
  2008年   44篇
  2007年   63篇
  2006年   53篇
  2005年   74篇
  2004年   38篇
  2003年   39篇
  2002年   56篇
  2001年   32篇
  2000年   40篇
  1999年   33篇
  1998年   26篇
  1997年   24篇
  1996年   27篇
  1995年   18篇
  1994年   16篇
  1993年   7篇
  1992年   17篇
  1991年   15篇
  1990年   16篇
  1989年   12篇
  1988年   11篇
  1987年   9篇
  1986年   15篇
  1985年   14篇
  1984年   6篇
  1983年   8篇
  1982年   4篇
  1981年   5篇
  1979年   4篇
  1978年   9篇
  1977年   5篇
  1976年   8篇
  1975年   6篇
  1962年   5篇
  1944年   2篇
排序方式: 共有1281条查询结果,搜索用时 808 毫秒
131.
The present study examined the psychometric properties and diagnostic efficiency of the Davidson Trauma Scale (DTS), a self-report measure of posttraumatic stress disorder (PTSD) symptoms. Participants included 158 U.S. military veterans who have served since September 11, 2001 (post-9/11). Results support the DTS as a valid self-report measure of PTSD symptoms. The DTS demonstrated good internal consistency, concurrent validity, and convergent and divergent validity. Diagnostic efficiency was excellent when discriminating between veterans with PTSD and veterans with no Axis I diagnosis. However, although satisfactory by conventional standards, efficiency was substantially attenuated when discriminating between PTSD and other Axis I diagnoses. Thus, results illustrate that potency of the DTS as a diagnostic aid was highly dependent on the comparison group used for analyses. Results are discussed in terms of applications to clinical practice and research.  相似文献   
132.
Ciguatoxins (CTX) are a suite of cyclic polyether toxins produced by the marine dinoflagellate Gambierdiscus sp., are potent activators of voltage-gated sodium channels and a leading cause of human poisoning from food fish. This report characterizes the genomic and proteomic response in whole blood of adult male mice exposed i.p. to 264 ng/kg of the Pacific congener of CTX (P-CTX-1) at 1, 4 and 24h. Whole genome microarray expression data were filtered by tightness of fit between replicates, fold change (1.8) and p-value (10(-5)), resulting in 183 annotated genes used for trending analysis, K-means clustering and ontology classification. Genes involved with cytokine signaling, proteasome complex and ribosomal function were dominant. qPCR performed on 19 genes of interest had a correlation of 0.95 to array results by Pearson's correlation coefficient. Serum protein analysis showed small but significant changes in 6 of 60 proteins assayed: Ccl2, Ccl12, CD40, IL-10, leptin and M-CSF. In large part, the gene expression was consistent with a Th2 immune response with interesting similarities to expression seen in asthmatic models.  相似文献   
133.
134.
135.
OBJECTIVES: To explore the potential of using step activity monitoring to detect differences in ambulatory activity associated with advancing age and declining function in community-dwelling seniors. DESIGN: Cross-sectional pilot study. SETTING: General communities of Seattle, Washington; Catonsville, Maryland; and Durham, North Carolina. PARTICIPANTS: Thirty healthy younger adults, 28 healthy older adults, and 12 older adults reporting functional limitations. MEASUREMENTS: Ambulatory activity data were collected over 6 days with the StepWatch 3. Average daily values were calculated for number of steps, number of minutes of activity, number of activity bouts, variability of minute-to-minute activity, and randomness of minute-to-minute activity fluctuations. RESULTS: Healthy older adults engaged in fewer bouts of activity (P=.03) and displayed less-variable activity (P=.02) than younger adults. Older adults reporting functional limitations not only engaged in fewer bouts of activity (P=.009) and less variable activity (P<.001) than younger adults, but also accumulated fewer total steps (P=.003) and minutes of activity (P=.008) and had less-random minute-to-minute activity fluctuations (P=.02). CONCLUSION: Step activity monitoring data were useful for detecting differences in ambulatory activity according to age and functional limitation. Monitor-based measures reflecting patterns of ambulatory activity show promise for use in studies of physical functioning.  相似文献   
136.
137.
138.
Role of the polycomb repressive complex 2 in acute promyelocytic leukemia   总被引:4,自引:0,他引:4  
Epigenetic changes are common alterations in cancer cells. Here, we have investigated the role of Polycomb group proteins in the establishment and maintenance of the aberrant silencing of tumor suppressor genes during transformation induced by the leukemia-associated PML-RARalpha fusion protein. We show that in leukemic cells knockdown of SUZ12, a key component of Polycomb repressive complex 2 (PRC2), reverts not only histone modification but also induces DNA demethylation of PML-RARalpha target genes. This results in promoter reactivation and granulocytic differentiation. Importantly, the epigenetic alterations caused by PML-RARalpha can be reverted by retinoic acid treatment of primary blasts from leukemic patients. Our results demonstrate that the direct targeting of Polycomb group proteins by an oncogene plays a key role during carcinogenesis.  相似文献   
139.
Everolimus (Eve) has shown good efficacy and safety profiles in clinical trials in combination with low doses of cyclosporine but there is limited experience in other modes, especially with calcineurin inhibitor elimination. We developed a retrospective study to analyze its clinical use after approval in Europe in 2005. Herein we have presented the results of a series of 272 patients followed for the first 6 months after Eve introduction. In 93.8% of cases Eve was introduced after the first month posttransplantation (conversion use), and 6 months after introduction, the CNI had been eliminated in 75% of cases. The main indication for Eve introduction was the diagnosis of a malignant neoplasm (42%), whereas the combined indication of prevention and/or treatment of toxicity, especially nephrotoxicity, accounted for 46.3% of cases. Initial doses were low (1.37 mg/d), but were progressively increased up to 2 mg/d at 6 months. Renal function remained unchanged during the follow-up period, whereas proteinuria moderately increased. Only 5 cases (2%) of acute rejection episodes were observed with excellent patient and graft survivals at 6 months after conversion. Further analysis of this extensive series of patients with a longer follow-up is needed.  相似文献   
140.
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