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   1877篇
  免费   96篇
  国内免费   28篇
耳鼻咽喉   11篇
儿科学   19篇
妇产科学   4篇
基础医学   245篇
口腔科学   634篇
临床医学   61篇
内科学   134篇
皮肤病学   14篇
神经病学   86篇
特种医学   28篇
外科学   319篇
综合类   172篇
预防医学   68篇
眼科学   11篇
药学   122篇
中国医学   56篇
肿瘤学   17篇
  2024年   3篇
  2023年   37篇
  2022年   46篇
  2021年   104篇
  2020年   50篇
  2019年   55篇
  2018年   52篇
  2017年   38篇
  2016年   41篇
  2015年   68篇
  2014年   134篇
  2013年   115篇
  2012年   97篇
  2011年   136篇
  2010年   101篇
  2009年   84篇
  2008年   100篇
  2007年   103篇
  2006年   103篇
  2005年   68篇
  2004年   66篇
  2003年   54篇
  2002年   55篇
  2001年   43篇
  2000年   40篇
  1999年   42篇
  1998年   32篇
  1997年   34篇
  1996年   11篇
  1995年   15篇
  1994年   13篇
  1993年   9篇
  1992年   8篇
  1991年   6篇
  1990年   6篇
  1989年   6篇
  1988年   4篇
  1987年   7篇
  1986年   5篇
  1985年   1篇
  1983年   3篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1977年   1篇
排序方式: 共有2001条查询结果,搜索用时 15 毫秒
1.
2.
Objectives:To compare a fluorescence-aided identification technique (FIT) with a conventional light source (CLS) for removing composite during debonding of brackets with respect to time needed, composite remnants, and tooth substance loss.Materials and Methods:Twelve maxillary models with 10 bovine teeth each were digitally surface-scanned and metal brackets were bonded on each tooth with Opal Seal and Opal Bond. Two operators: an experienced orthodontist (A) and an undergraduate student (B) received six models each and were asked to remove the composite remnants with a tungsten carbide bur and Sof-Lex discs by both a conventional light source (CLS group, n = 3), and fluorescent inducing light (FIT group, n = 3). The time taken was recorded, and a postoperative scan was digitally superimposed on the preoperative scan to quantify number of teeth with composite remnants and volume and thickness of enamel loss and composite remnants. Chi-square test and independent t-tests were performed to compare methods with a significance level of 5%.Results:Compared to CLS, both operators needed significantly less time when using the FIT method and degree of enamel loss, height, and volume of composite remnants and total remaining composite remnants were significantly reduced. By FIT, the volume of enamel loss was significantly reduced for operator A only. Operator B removed the same enamel volume with either method.Conclusions:Cleanup after orthodontic debonding with the FIT was superior regarding time needed and removal of composite remnants. Total enamel loss reduction was operator-dependent.  相似文献   
3.
4.
While decreasing trend in gender differences in alcohol use disorders was reported in Western countries, the change in Asian countries is unknown. This study aims to explore the shifts in gender difference in alcohol abuse (AA) and dependence (AD) in Korea. We compared the data from two nation-wide community surveys to evaluate gender differences in lifetime AA and AD by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Face-to-face interviews using the Composite International Diagnostic Interview (CIDI) were applied to all subjects in 2001 (n=6,220) and 2011 (n=6,022). Male-to-female ratio of odds was decreased from 6.41 (95% CI, 4.81-8.54) to 4.37 (95% CI, 3.35-5.71) for AA and from 3.75 (95% CI, 2.96-4.75) to 2.40 (95% CI, 1.80-3.19) for AD. Among those aged 18-29, gender gap even became statistically insignificant for AA (OR, 1.59; 95% CI, 0.97-2.63) and AD (OR, 1.18; 95% CI, 0.80-2.41) in 2011. Men generally showed decreased odds for AD (0.55; 95% CI, 0.45-0.67) and women aged 30-39 showed increased odds for AA (2.13; 95% CI 1.18-3.84) in 2011 compared to 2001. Decreased AD in men and increased AA in women seem to contribute to the decrease of gender gap. Increased risk for AA in young women suggests needs for interventions.  相似文献   
5.
6.
Acute GVHD occurs in nearly 50% of patients receiving hematopoietic cell transplantation (HCT), and is the major driver of mortality. However, progress in the development of new acute GVHD therapeutics has been slow, in part due to heterogeneity in acute GVHD data collection and interpretation among centers. Herein, we first describe the methods used by the Mount Sinai Acute GVHD International Consortium (MAGIC) to standardize acute GVHD data collection and curation. We then review the utility of serum biomarkers, specifically the MAGIC Algorithm Probability (MAP) that combines two GI biomarkers (ST2 and REG3α) that has been shown to be more accurate than changes in clinical symptom severity after GVHD treatment. We then present preliminary data on the feasibility of a surrogate clinical trial endpoint that combines clinical response and MAP two weeks after treatment. This novel endpoint is an earlier and potentially better predictor of non-relapse mortality than the current gold standard of clinical response four weeks after treatment.  相似文献   
7.
8.
Composite intestinal adenoma-microcarcinoid (CIAM) is a rare intestinal lesion consisting of conventional adenoma and small, well differentiated carcinoid [microcarcinoid (MC)] at its base. The incidence of CIAM is 3.8% in surgically resected colorectal polyps. While its pathogenesis is unknown, studies support the role of Wnt/β-catenin pathway in the tumorigenesis of CIAM. CIAMs have been primarily reported in the colon wherein they present as polyps with well-defined margins, similar to conventional adenomatous polyps. MC is usually found in adenomatous polyps with high-risk features such as large size, villous architecture, or high grade dysplasia. Histologically, the MC component is often multifocal and spans 3.9 to 5.8 millimeters in size. MC is usually confined within the mucosa but occasional CIAM cases with MC extending to the submucosa have been reported. MC of CIAM demonstrates bland cytology and inconspicuous proliferative activity. The lesional cells are positive for synaptophysin and 60% to 100% of cases show nuclear β-catenin positivity. MC poses a diagnostic challenge with its morphologic and immunohistochemical resemblance to both benign and malignant lesions, including squamous morules/metaplasia, adenocarcinoma, squamous cell carcinoma, sporadic neuroendocrine tumor and goblet cell adenocarcinoma. CIAM is an indolent lesion with a favorable outcome. Complete removal by polypectomy is considered curative. Awareness and recognition of this rare entity will help arrive at correct diagnosis and improve patient care. Currently, CIAM is not recognized as a subtype of mixed neuroendocrine-non-neuroendocrine neoplasm by WHO.  相似文献   
9.
10.
Objective To explore associations between lipoprotein-associated phospholipase A2(Lp-PLA2) and the risk of cardiovascular events in a Chinese population, with a long-term follow-up.Methods A random sample of 2,031 participants(73.6% males, mean age = 60.4 years) was derived from the Asymptomatic Polyvascular Abnormalities Community study(APAC) from 2010 to 2011. Serum Lp-PLA2 levels were determined by enzyme-linked immunosorbent assay(ELISA). The composite endpoint was a combination of first-eve...  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