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   364832篇
  免费   24704篇
  国内免费   8293篇
耳鼻咽喉   4459篇
儿科学   10191篇
妇产科学   7028篇
基础医学   28839篇
口腔科学   8215篇
临床医学   40671篇
内科学   50024篇
皮肤病学   4807篇
神经病学   20041篇
特种医学   9722篇
外国民族医学   39篇
外科学   40281篇
综合类   53345篇
现状与发展   15篇
一般理论   29篇
预防医学   35297篇
眼科学   5523篇
药学   30915篇
  388篇
中国医学   30627篇
肿瘤学   17373篇
  2023年   5992篇
  2022年   10456篇
  2021年   14292篇
  2020年   13377篇
  2019年   19033篇
  2018年   16687篇
  2017年   13595篇
  2016年   11199篇
  2015年   10558篇
  2014年   21392篇
  2013年   22994篇
  2012年   19380篇
  2011年   20999篇
  2010年   16914篇
  2009年   15657篇
  2008年   15330篇
  2007年   15768篇
  2006年   13877篇
  2005年   12075篇
  2004年   9866篇
  2003年   8573篇
  2002年   6791篇
  2001年   6080篇
  2000年   5007篇
  1999年   4361篇
  1998年   3629篇
  1997年   3439篇
  1996年   2993篇
  1995年   2838篇
  1994年   2762篇
  1993年   2178篇
  1992年   2180篇
  1991年   1911篇
  1990年   1680篇
  1989年   1506篇
  1988年   1418篇
  1987年   1209篇
  1985年   3887篇
  1984年   4892篇
  1983年   3395篇
  1982年   3874篇
  1981年   3622篇
  1980年   3220篇
  1979年   2959篇
  1978年   2571篇
  1977年   1940篇
  1976年   2173篇
  1975年   1634篇
  1974年   1432篇
  1973年   1281篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
《Immunity》2022,55(9):1725-1731.e4
  1. Download : Download high-res image (182KB)
  2. Download : Download full-size image
  相似文献   
23.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
24.
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations.  相似文献   
25.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
26.
27.
Forgiveness has been found one substantial element in the recovery for women survivors from intimate partner violence following the termination of the abusive relationship. To further investigate the details of forgiveness in this specific context, the present study explored the process of forgiveness using grounded theory. In-depth and semi-structured interviews were conducted with 25 Chinese women survivors of IPV. The findings suggest that forgiveness is a strength-based process including empowerment, transformation, and integration phases. In the empowerment phase, survivors obtain strength at the intrapersonal, behavioural, and interpersonal levels. In the transformation phase, survivors complete cognitive transformation for their IPV experiences and emotional transformation towards former partners. In the integration phase, survivors—now freed from the past—reflect upon and apply the changes they have undergone. Two trajectories in the process were found. One trajectory is going through stages sequentially and the other trajectory is experiencing back and forth between empowerment and transformation stages before moving into the integration stage. The study's findings broaden our knowledge of the strength-based forgiveness process that women survivors of IPV undergo during recovery. Practitioners and policymakers could develop programmes and policies that support forgiveness by holistically facilitating their recovery and empowerment like assistance in dealing with life difficulties and promoting their reconnection with social networks. To improve the transferability and validity of the findings, the forgiveness of survivors of IPV could be explored in a diverse sample (e.g., survivors with low educational background or live in the rural area).  相似文献   
28.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  相似文献   
29.
30.
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