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   130815篇
  免费   7988篇
  国内免费   1126篇
耳鼻咽喉   2017篇
儿科学   1993篇
妇产科学   1958篇
基础医学   20829篇
口腔科学   3147篇
临床医学   12264篇
内科学   23283篇
皮肤病学   4141篇
神经病学   10672篇
特种医学   7624篇
外科学   17366篇
综合类   606篇
现状与发展   3篇
一般理论   37篇
预防医学   6784篇
眼科学   3299篇
药学   11823篇
中国医学   1514篇
肿瘤学   10569篇
  2023年   699篇
  2022年   2119篇
  2021年   4591篇
  2020年   2218篇
  2019年   3098篇
  2018年   3880篇
  2017年   3139篇
  2016年   4102篇
  2015年   5680篇
  2014年   6748篇
  2013年   7845篇
  2012年   11691篇
  2011年   11228篇
  2010年   6442篇
  2009年   5537篇
  2008年   7834篇
  2007年   7477篇
  2006年   6740篇
  2005年   6232篇
  2004年   5434篇
  2003年   4739篇
  2002年   4065篇
  2001年   3084篇
  2000年   2839篇
  1999年   2171篇
  1998年   934篇
  1997年   700篇
  1996年   538篇
  1995年   473篇
  1994年   407篇
  1993年   351篇
  1992年   763篇
  1991年   723篇
  1990年   651篇
  1989年   560篇
  1988年   473篇
  1987年   474篇
  1986年   346篇
  1985年   373篇
  1984年   266篇
  1983年   203篇
  1982年   141篇
  1981年   174篇
  1980年   134篇
  1979年   225篇
  1978年   163篇
  1976年   134篇
  1975年   121篇
  1974年   140篇
  1973年   124篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
31.
32.
ObjectiveTo compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS).Materials and MethodsThe Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements.ResultsLumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm3; 95% confidence interval [CI], 4.9–24.3 mm3); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, −0.7 mm3; 95% CI, −9.1–7.7 mm3). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm2; 95% CI, 0.89–1.25 mm2) but not in the larger lumen area group (mean of difference, −0.07 mm2; 95% CI, −0.22–0.08 mm2). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm2; 95% CI, 0.27–0.65 mm2) than in that of IVUS and SATM (1.53 mm2; 95% CI, 1.27–1.79 mm2).ConclusionSATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.  相似文献   
33.
34.
Hypertrophic lichen planus (HLP) is a T‐cell‐mediated process typically presenting with hypertrophic or verrucous plaques on the lower limbs. We report the case of a 24‐year‐old woman with a history of HLP since age 3 years presenting with rapid malignant transformation of one lesion into a large squamous cell carcinoma (SCC). Subsequent examination revealed progressive, widespread metastatic involvement, and the patient ultimately died from her disease. SCC associated with HLP is rare, with a review of the literature revealing fewer than 50 cases. This case highlights the need to be aware of suspicious changes in HLP and to educate patients as to when to be reevaluated.  相似文献   
35.
36.
TL1A is a TNF‐like cytokine which has been shown to co‐stimulate TH1 and TH17 responses during chronic inflammation. The expression of this novel cytokine has been investigated in inflammatory disorders like rheumatoid arthritis and inflammatory bowel disease, but little is known about expression and induction in psoriasis. Indeed, the pathogenesis in psoriasis is still not fully understood and it is speculated that cytokines other than TNF‐α are important in subsets of patients. Also, for patients with severe disease that are treated with systemic anti‐TNF‐α blockade, novel candidates to be used as disease and response biomarkers are of high interest. Here, we demonstrate TL1A expression in biopsies from psoriatic lesions. Also, we investigated spontaneous and induced TL1A secretion from PBMCs and blood levels from a cohort of psoriasis patients. Here, increased spontaneous secretion from PBMCs was observed as compared to healthy controls and a small subset of patients had highly elevated TL1A in the blood. Interestingly, activation of PBMCs with various cytokines showed a decreased sensitivity for TL1A activation in psoriasis patients compared to healthy controls.TL1A levels in blood and biopsies could not be correlated with disease activity with this patient cohort. Thus, additional large‐scale studies are warranted to investigate TL1A as a biomarker.  相似文献   
37.
38.
39.
Erythema induratum of Bazin (EIB) is a form of tuberculid resulting from hypersensitivity to tuberculosis antigen. EIB occurs most commonly in middle‐aged women and is not typically seen in children. Here, we present a rare case of EIB, presenting as a chronic nodular panniculitis, in a 10‐year‐old Korean boy.  相似文献   
40.
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