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   62265篇
  免费   4522篇
  国内免费   144篇
耳鼻咽喉   819篇
儿科学   1721篇
妇产科学   1592篇
基础医学   10238篇
口腔科学   1677篇
临床医学   5789篇
内科学   12333篇
皮肤病学   961篇
神经病学   5866篇
特种医学   2624篇
外国民族医学   45篇
外科学   8125篇
综合类   527篇
一般理论   83篇
预防医学   4851篇
眼科学   1193篇
药学   4551篇
中国医学   162篇
肿瘤学   3774篇
  2021年   761篇
  2020年   615篇
  2019年   905篇
  2018年   1109篇
  2017年   780篇
  2016年   905篇
  2015年   1080篇
  2014年   1328篇
  2013年   2315篇
  2012年   2986篇
  2011年   3082篇
  2010年   2220篇
  2009年   1857篇
  2008年   2787篇
  2007年   2929篇
  2006年   2909篇
  2005年   2750篇
  2004年   2814篇
  2003年   2551篇
  2002年   2617篇
  2001年   2131篇
  2000年   2169篇
  1999年   1919篇
  1998年   763篇
  1997年   639篇
  1996年   551篇
  1995年   651篇
  1994年   546篇
  1993年   597篇
  1992年   1439篇
  1991年   1392篇
  1990年   1331篇
  1989年   1315篇
  1988年   1097篇
  1987年   1100篇
  1986年   1042篇
  1985年   959篇
  1984年   689篇
  1983年   645篇
  1982年   454篇
  1981年   440篇
  1980年   375篇
  1979年   622篇
  1978年   373篇
  1977年   357篇
  1975年   369篇
  1974年   411篇
  1973年   346篇
  1972年   339篇
  1971年   301篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer mainly caused by asbestos exposure. Specific and sensitive noninvasive biomarkers may facilitate and enhance screening programs for the early detection of cancer. We investigated DNA methylation (DNAm) profiles in MPM prediagnostic blood samples in a case-control study nested in the European Prospective Investigation into Cancer and nutrition (EPIC) cohort, aiming to characterise DNAm biomarkers associated with MPM. From the EPIC cohort, we included samples from 135 participants who developed MPM during 20 years of follow-up and from 135 matched, cancer-free, controls. For the discovery phase we selected EPIC participants who developed MPM within 5 years from enrolment (n = 36) with matched controls. We identified nine differentially methylated CpGs, selected by 10-fold cross-validation and correlation analyses: cg25755428 (MRI1), cg20389709 (KLF11), cg23870316, cg13862711 (LHX6), cg06417478 (HOOK2), cg00667948, cg01879420 (AMD1), cg25317025 (RPL17) and cg06205333 (RAP1A). Receiver operating characteristic (ROC) analysis showed that the model including baseline characteristics (age, sex and PC1wbc) along with the nine MPM-related CpGs has a better predictive value for MPM occurrence than the baseline model alone, maintaining some performance also at more than 5 years before diagnosis (area under the curve [AUC] < 5 years = 0.89; AUC 5-10 years = 0.80; AUC >10 years = 0.75; baseline AUC range = 0.63-0.67). DNAm changes as noninvasive biomarkers in prediagnostic blood samples of MPM cases were investigated for the first time. Their application can improve the identification of asbestos-exposed individuals at higher MPM risk to possibly adopt more intensive monitoring for early disease identification.  相似文献   
3.
4.
AIDS and Behavior - To assess PrEP service delivery preferences among Black cis-gender women living in urban and rural settings in Alabama, we conducted a cross-sectional discrete choice experiment...  相似文献   
5.
6.
7.
Upfront resection is becoming a rarer indication for pancreatic ductal adenocarcinoma, as biologic behavior and natural history of the disease has boosted indications for neoadjuvant treatments. Jaundice, gastric outlet obstruction and acute cholecystitis can frequently complicate this window of opportunity, resulting in potentially deleterious chemotherapy discontinuation, whose resumption relies on effective, prompt and long-lasting management of these complications. Although therapeutic endoscopic ultrasound (t-EUS) can potentially offer some advantages over comparators, its use in potentially resectable patients is primal and has unfairly been restricted for fear of potential technical difficulties during subsequent surgery. This is a narrative review of available evidence regarding EUS-guided choledochoduodenostomy, gastrojejunostomy and gallbladder drainage in the bridge-to-surgery scenario. Proof-of-concept evidence suggests no influence of t-EUS procedures on outcomes of eventual subsequent surgery. Moreover, the very high efficacy-invasiveness ratio over comparators in managing pancreatic cancer-related symptoms or complications can provide a powerful weapon against chemotherapy discontinuation, potentially resulting in higher subsequent resectability. Available evidence is discussed in this short paper, together with technical notes that might be useful for endoscopists and surgeons operating in this scenario. No published evidence supports restricting t-EUS in potential surgical candidates, especially in the setting of pancreatic cancer patients undergoing neoadjuvant chemotherapy. Bridge-to-surgery t-EUS deserves further prospective evaluation.  相似文献   
8.
9.
10.
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of...  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