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   381379篇
  免费   43524篇
  国内免费   12575篇
耳鼻咽喉   2929篇
儿科学   5620篇
妇产科学   6760篇
基础医学   40712篇
口腔科学   5195篇
临床医学   34133篇
内科学   43332篇
皮肤病学   3000篇
神经病学   8251篇
特种医学   10678篇
外国民族医学   327篇
外科学   44208篇
综合类   55861篇
现状与发展   51篇
一般理论   28篇
预防医学   21419篇
眼科学   4422篇
药学   32551篇
  169篇
中国医学   14026篇
肿瘤学   103806篇
  2024年   727篇
  2023年   6282篇
  2022年   9982篇
  2021年   17509篇
  2020年   16139篇
  2019年   15151篇
  2018年   14606篇
  2017年   15216篇
  2016年   16225篇
  2015年   17700篇
  2014年   26442篇
  2013年   27232篇
  2012年   22456篇
  2011年   23849篇
  2010年   18817篇
  2009年   18794篇
  2008年   19014篇
  2007年   19642篇
  2006年   17583篇
  2005年   15856篇
  2004年   13474篇
  2003年   11569篇
  2002年   9153篇
  2001年   8731篇
  2000年   7186篇
  1999年   6369篇
  1998年   4941篇
  1997年   4424篇
  1996年   4097篇
  1995年   3832篇
  1994年   3275篇
  1993年   2806篇
  1992年   2457篇
  1991年   2142篇
  1990年   1750篇
  1989年   1614篇
  1988年   1488篇
  1987年   1193篇
  1986年   906篇
  1985年   1066篇
  1984年   1012篇
  1983年   658篇
  1982年   755篇
  1981年   662篇
  1980年   574篇
  1979年   453篇
  1978年   344篇
  1977年   287篇
  1976年   300篇
  1975年   199篇
排序方式: 共有10000条查询结果,搜索用时 25 毫秒
21.
Breast core biopsies are a standard component of the triple approach that includes clinical examination, imaging and tissue sampling. Conventional cores, diagnostic vacuum assisted biopsy and vacuum assisted excisions are established methods for sampling and managing breast lesions. It is important to be aware of the potential pitfalls in the technical handling and interpretation of the limited core biopsy samples. Here, we present a clinically oriented, well illustrated overview of the common diagnostic pitfalls based on the author's diagnostic and second opinion practice, emphasize the value of clinicopathological correlation and provide histological tips and clues with useful immunohistochemistry to aid the reporting pathologists in their daily interpretation of breast core biopsies.  相似文献   
22.
23.
24.
25.
26.
《Cancer cell》2021,39(9):1214-1226.e10
  1. Download : Download high-res image (204KB)
  2. Download : Download full-size image
  相似文献   
27.
Abstract

Purpose

Financial hardship can be a major cause of distress among persons with cancer, resulting in chronic stress and impacting physical and emotional health. This paper provides an analysis of the lived experience of cancer patients’ financial hardship from diagnosis to post-treatment.  相似文献   
28.
ObjectivesMap regional lymph node metastases for lateralized oral cavity squamous cell carcinoma (OCSCC) and evaluate factors associated with regional metastases and recurrence.Materials and methodsRetrospective cohort study of 715 patients with lateralized OCSCC surgically treated in 1997–2011. Analysis was performed using log-rank, Kaplan-Meier, and multivariable logistic and Cox regression.ResultsRegional metastases were identified in ipsilateral levels IIA (24%), IB (18%), III (13%), V (9%), IV (7%), IA (2%) and IIB (1%) and the contralateral neck (3%). Lymphovascular invasion (LVI) (Hazard Ratio [HR] 2.2, 95% Confidence Interval [CI] 1.2–3.9) and T category (T3 vs. T1: HR 4.1, 95% CI 1.9–9.3; T4 vs. T1: HR 2.3, 95% CI 1.2–4.3) were associated with regional metastases. Most (71%) isolated regional metastatic recurrences were in undissected levels of the neck, including 58% in levels IV and V. Tumors of the hard palate (HR 4.3, 95% CI 1.2–16.1), upper alveolus (HR 3.2, 95% CI 1.0–4.7) or with LVI (HR 2.0, 95% CI 1.0–3.9) were associated with isolated regional recurrence. For upper alveolar/hard palate tumors, depth of invasion (DOI) ≥4 mm (P = .003) and LVI (P = .04) were associated with regional metastases.ConclusionsFor lateralized OCSCC, elective neck dissection of level IIB or the contralateral neck may rarely be needed, but additional surgical or radiation treatment of levels IV and V may be considered based on patient risk factors, including T category 3–4 or LVI. For upper alveolar/hard palate tumors, DOI ≥4 mm is an appropriate threshold for elective neck dissection.  相似文献   
29.
30.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  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