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   134654篇
  免费   8681篇
  国内免费   1625篇
耳鼻咽喉   1975篇
儿科学   2063篇
妇产科学   1965篇
基础医学   21087篇
口腔科学   3227篇
临床医学   13089篇
内科学   23697篇
皮肤病学   4169篇
神经病学   10692篇
特种医学   7630篇
外国民族医学   4篇
外科学   17522篇
综合类   1971篇
现状与发展   3篇
一般理论   28篇
预防医学   7324篇
眼科学   3411篇
药学   12319篇
  5篇
中国医学   2047篇
肿瘤学   10732篇
  2023年   830篇
  2022年   1998篇
  2021年   5114篇
  2020年   2612篇
  2019年   3368篇
  2018年   4066篇
  2017年   3362篇
  2016年   4274篇
  2015年   5969篇
  2014年   7076篇
  2013年   8153篇
  2012年   12144篇
  2011年   11621篇
  2010年   6744篇
  2009年   5768篇
  2008年   8090篇
  2007年   7673篇
  2006年   6935篇
  2005年   6333篇
  2004年   5448篇
  2003年   4748篇
  2002年   4084篇
  2001年   3106篇
  2000年   2859篇
  1999年   2210篇
  1998年   949篇
  1997年   721篇
  1996年   538篇
  1995年   484篇
  1994年   423篇
  1993年   354篇
  1992年   768篇
  1991年   714篇
  1990年   657篇
  1989年   568篇
  1988年   478篇
  1987年   476篇
  1986年   340篇
  1985年   373篇
  1984年   271篇
  1983年   196篇
  1982年   134篇
  1981年   171篇
  1980年   130篇
  1979年   224篇
  1978年   167篇
  1976年   135篇
  1975年   122篇
  1974年   142篇
  1973年   120篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
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   
34.
35.
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   
36.
37.
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   
38.
39.
40.
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   
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