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   3296篇
  免费   208篇
  国内免费   21篇
耳鼻咽喉   18篇
儿科学   107篇
妇产科学   51篇
基础医学   559篇
口腔科学   58篇
临床医学   267篇
内科学   649篇
皮肤病学   53篇
神经病学   410篇
特种医学   48篇
外科学   432篇
综合类   24篇
一般理论   7篇
预防医学   390篇
眼科学   50篇
药学   146篇
中国医学   5篇
肿瘤学   251篇
  2023年   53篇
  2022年   84篇
  2021年   130篇
  2020年   78篇
  2019年   96篇
  2018年   97篇
  2017年   74篇
  2016年   84篇
  2015年   116篇
  2014年   145篇
  2013年   195篇
  2012年   252篇
  2011年   285篇
  2010年   148篇
  2009年   140篇
  2008年   189篇
  2007年   190篇
  2006年   221篇
  2005年   208篇
  2004年   192篇
  2003年   154篇
  2002年   133篇
  2001年   13篇
  2000年   3篇
  1999年   14篇
  1998年   24篇
  1997年   14篇
  1996年   18篇
  1995年   15篇
  1994年   16篇
  1993年   14篇
  1992年   9篇
  1991年   7篇
  1989年   4篇
  1988年   4篇
  1987年   5篇
  1986年   5篇
  1985年   4篇
  1984年   8篇
  1983年   5篇
  1982年   6篇
  1981年   3篇
  1980年   3篇
  1978年   6篇
  1977年   4篇
  1976年   4篇
  1975年   3篇
  1972年   3篇
  1965年   3篇
  1945年   4篇
排序方式: 共有3525条查询结果,搜索用时 15 毫秒
61.
Non‐Uremic Calciphylaxis (NUC) is a rare condition that often manifests as intractable and painful integumentary wounds, afflicting patients with a high burden of co‐morbidity. The Endocannabinoid System (ECS) is a ubiquitous signalling system that is theorised to be dysregulated within wound beds and associated peri‐wound tissues. Preclinical research has shown that the dominant chemical classes derived from the cannabis plant, cannabinoids, terpenes, and flavonoids, interact with the integumentary ECS to promote wound closure and analgesia. This is a prospective open label cohort study involving two elderly Caucasian females with recalcitrant NUC leg ulcers of greater than 6 months duration. Topical Cannabis‐Based Medicines (TCBM) composed of cannabinoids, terpenes, and flavonoids were applied daily to both the wound bed and peri‐wound tissues until complete wound closure was achieved. Wounds were photographed regularly, and the digital images were subjected to planimetric analysis to objectively quantify the degree of granulation and epithelization. Analgesic utilisation, as a surrogate/proxy for pain scores, was also tracked. The cohort had a mean M3 multimorbidity index score of 3.31. Complete wound closure was achieved in a mean of 76.3 days. Additionally, no analgesics were required after a mean of 63 days. The treatments were well tolerated with no adverse reactions. The positive results demonstrated in very challenging wounds such as NUC, among highly complex patients, suggest that TCBM may have an even broader role within integumentary and wound management. This treatment paradigm warrants being trialled in other wound types and classes, and ultimately should be subjected to randomised controlled trials.  相似文献   
62.

Background

For breast-conserving surgery, the method of margin assessment that most frequently achieves negative margins without increasing the volume of tissue excised is uncertain. We examined our institutional experience with three different margin assessment methods used by six experienced breast surgeons.

Methods

Patients undergoing breast-conserving surgery for invasive carcinoma during July to December of a representative year during which each method was performed (perpendicular, 2003; tangential, 2004; cavity shave, 2011) were included. The effect of margin method on the positive margin rate at first excision and the total volume excised to achieve negative margins were evaluated by multivariable analysis, by surgeon, and by tumor size and presence of extensive intraductal component (EIC).

Results

A total of 555 patients were identified, as follows: perpendicular, 140; tangential, 124; and cavity shave, 291. The tangential method had a higher rate of positive margins at first excision than the perpendicular and cavity-shave methods (49, 15, 11 %, respectively; p < 0.0001). Median volumes to achieve negative margins were similar (55 ml perpendicular; 64 ml tangential; 62 ml cavity shave; p = 0.24). Four of six surgeons had the lowest rate of positive margins with the cavity-shave method, which was significant when compared to the tangential method (p < 0.0001) but not the perpendicular method (p = 0.37). The volume excised by the three methods varied by surgeon (p < 0.0001). The perpendicular method was optimal for T1 tumors without EIC; the cavity-shave method tended to be superior for T2–T3 tumors and/or EIC.

Conclusions

Although the cavity-shave method may decrease the rates of positive margins, its effect on volume is variable among surgeons and may result in an increase in the total volume excised for some surgeons and for small tumors without EIC.  相似文献   
63.
Negative affect appears frequently in rheumatic diseases, but studies about their importance and prevalence in systemic sclerosis patients are scarce, and the results are inconclusive separately. We conducted a comprehensive search on April 2013 of PubMed, Medline, and PsycINFO databases to identify original research studies published. A total of 48 studies were included in this systematic review. We found negative emotions have very high levels in these patients, compared to both healthy population other chronic rheumatic patients assessed with the same instruments and cutoffs. Depression has been, of the three negative emotions that we approach to in this review, the most widely studied in systemic sclerosis, followed by anxiety. Despite the fact that anger is a common emotion in these diseases is poorly studied. Methodologic issues limited the ability to draw strong conclusions from studies of predictors. Disease-specific symptoms (swollen joints, gastrointestinal and respiratory symptoms and digital ulcers) and factors related to physical appearance were associated with negative emotions. Interdisciplinary care and biopsychosocial approach would have a great benefit in the clinical management of these patients.  相似文献   
64.
Serum thymus and activation regulated chemokine (TARC) levels reflect classical Hodgkin lymphoma (cHL) disease activity and correspond with treatment response. We compared mid-treatment interim TARC (iTARC) with interim 18F-fluorodeoxyglucose positron-emission tomography (iPET) imaging to predict modified progression-free survival (mPFS) in a group of 95 patients with cHL. High iTARC levels were found in nine and positive iPET in 17 patients. The positive predictive value (PPV) of iTARC for a 5-year mPFS event was 88% compared to 47% for iPET. The negative predictive value was comparable at 86% for iTARC and 85% for iPET. Serum iTARC levels more accurately reflect treatment response with a higher PPV compared to iPET.  相似文献   
65.
66.
Journal of Thrombosis and Thrombolysis - A high incidence of thrombotic events, particularly deep vein thrombosis and pulmonary embolism, has been clearly documented in COVID-19 patients. In...  相似文献   
67.
Adaptive ongoing behavior requires using immediate sensory input to guide upcoming actions. Using a novel paradigm with volitional exploration of visuo‐spatial scenes, we revealed novel deficits among hippocampal amnesic patients in effective spatial exploration of scenes, indicated by less‐systematic exploration patterns than those of healthy comparison subjects. The disorganized exploration by amnesic patients occurred despite successful retention of individual object locations across the entire exploration period, indicating that exploration impairments were not secondary to rapid decay of scene information. These exploration deficits suggest that amnesic patients are impaired in integrating memory for recent actions, which may include information such as locations just visited and scene content, to plan immediately forthcoming actions. Using a novel task that measured the on‐line links between sensory input and behavior, we observed the critical role of the hippocampus in modulating ongoing behavior. © 2013 Wiley Periodicals, Inc.  相似文献   
68.
Given that ecological models of development highlight the interacting influences of multiple environments, further research is needed that explores ethnic-racial socialization from multiple contexts. The current study explores how families, schools, neighborhoods, and the Internet jointly impact academic outcomes, critical consciousness, and psychological well-being in adolescents, both through socialization messages and experiences with racial discrimination. The research questions were: (a) What profiles of multiple contexts of socialization exist? and (b) How are the different profiles associated with academic outcomes, critical consciousness, and psychological well-being? The sample consisted of 1,084 U.S. adolescents aged 13–17 (M = 14.99, SD = 1.37; 49% girls) from four ethnic-racial groups: 25.6% Asian American, 26.3% Black/African American, 25.3% Latinx, and 22.9% White. The participants completed online surveys of socialization and discrimination from four contexts and three types of outcomes: academic outcomes, critical consciousness, and well-being. A latent profile analysis revealed three profiles: Average, High Discrimination, and Positive School. The Positive School class had the most positive academic outcomes and well-being. The High Discrimination class reported the highest critical consciousness. Their academic outcomes and well-being were similar to the Average group. The findings support complexity in perceptions of socialization from different contexts and the associations of socialization with youth outcomes.  相似文献   
69.
Transthoracic parametric Doppler (TPD), unlike conventional ultrasonography, measures signals originating from movements of pulmonary blood vessel walls. In this pilot study, we tested TPD in 15 patients diagnosed with pulmonary embolism on computed tomography pulmonary angiography. Results were mapped to the upper, middle, and lower thirds of the right lung. In the lower third, TPD yielded 100% specificity and positive predictive value for acute pulmonary embolism. If validated in a larger series, this rapid bedside technique might obviate the need for computed tomography in specific cases. This could be advantageous in patients who are unstable, in intensive care, or have allergies to iodinated contrast material.  相似文献   
70.
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