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   1422407篇
  免费   124745篇
  国内免费   4216篇
耳鼻咽喉   23100篇
儿科学   47702篇
妇产科学   40311篇
基础医学   191429篇
口腔科学   36933篇
临床医学   134168篇
内科学   296204篇
皮肤病学   33800篇
神经病学   113814篇
特种医学   56079篇
外国民族医学   366篇
外科学   236149篇
综合类   26781篇
现状与发展   73篇
一般理论   313篇
预防医学   99881篇
眼科学   32350篇
药学   99318篇
  1篇
中国医学   2519篇
肿瘤学   80077篇
  2018年   18844篇
  2017年   15932篇
  2016年   18068篇
  2015年   19589篇
  2014年   30707篇
  2013年   39349篇
  2012年   39414篇
  2011年   41805篇
  2010年   31303篇
  2009年   33618篇
  2008年   40930篇
  2007年   42368篇
  2006年   45225篇
  2005年   41894篇
  2004年   39782篇
  2003年   37755篇
  2002年   37393篇
  2001年   61668篇
  2000年   62411篇
  1999年   53761篇
  1998年   17746篇
  1997年   16087篇
  1996年   16205篇
  1995年   15336篇
  1994年   13555篇
  1993年   12313篇
  1992年   42239篇
  1991年   41668篇
  1990年   40877篇
  1989年   39778篇
  1988年   37039篇
  1987年   36157篇
  1986年   34547篇
  1985年   32804篇
  1984年   24439篇
  1983年   21299篇
  1982年   12869篇
  1981年   11302篇
  1979年   22931篇
  1978年   16198篇
  1977年   14106篇
  1976年   13195篇
  1975年   14463篇
  1974年   16898篇
  1973年   16285篇
  1972年   15594篇
  1971年   14415篇
  1970年   13443篇
  1969年   12808篇
  1968年   11995篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Alterations in autophagy are increasingly being recognized in the pathogenesis of proteinopathies like Alzheimer's disease (AD). This study was conducted to evaluate whether melatonin treatment could provide beneficial effects in an Alzheimer model related to tauopathy by improving the autophagic flux and, thereby, prevent cognitive decline. The injection of AAV‐hTauP301L viral vectors and treatment/injection with okadaic acid were used to achieve mouse and human ex vivo, and in vivo tau‐related models. Melatonin (10 μmol/L) impeded oxidative stress, tau hyperphosphorylation, and cell death by restoring autophagy flux in the ex vivo models. In the in vivo studies, intracerebroventricular injection of AAV‐hTauP301L increased oxidative stress, neuroinflammation, and tau hyperphosphorylation in the hippocampus 7 days after the injection, without inducing cognitive impairment; however, when animals were maintained for 28 days, cognitive decline was apparent. Interestingly, late melatonin treatment (10 mg/kg), starting once the alterations mentioned above were established (from day 7 to day 28), reduced oxidative stress, neuroinflammation, tau hyperphosphorylation, and caspase‐3 activation; these observations correlated with restoration of the autophagy flux and memory improvement. This study highlights the importance of autophagic dysregulation in tauopathy and how administration of pharmacological doses of melatonin, once tauopathy is initiated, can restore the autophagy flux, reduce proteinopathy, and prevent cognitive decline. We therefore propose exogenous melatonin supplementation or the development of melatonin derivatives to improve autophagy flux for the treatment of proteinopathies like AD.  相似文献   
102.
103.
104.
105.
106.
107.
108.
109.
PurposeOur purpose was to determine the effect of chemoradiotherapy (CRT) on patient-reported quality of life (QOL) for patients with intact pancreas cancer.Methods and MaterialsWe reviewed a prospective QOL registry for patients with intact, clinically localized pancreatic ductal adenocarcinoma treated with CRT between June 2015 and November 2018. QOL was assessed pre-CRT (immediately before CRT, after neoadjuvant chemotherapy) and at the completion of CRT with the Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) and its component parts: FACT-General (FACT-G) and hepatobiliary cancer subscore (HCS). A minimally important difference from pre-CRT was defined as ≥ 6, 5, and 8 points for FACT-G, HCS, and FACT-Hep, respectively.ResultsOf 157 patients who underwent CRT, 100 completed both pre- and post-CRT surveys and were included in the primary analysis. Median age at diagnosis was 65 years (range, 23-90). National Comprehensive Cancer Network resectability status was resectable (3%), borderline resectable (40%), or locally advanced (57%). Folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX) (75%) or gemcitabine and nab-paclitaxel (42%) were given for a median of 6 cycles (range, 0-42) before CRT. Radiation therapy techniques included 3-dimensional conformal (22%), intensity modulated photon (55%), and intensity modulated proton (23%) radiation therapy to a median dose of 50 Gy (range, 36-62.5). Concurrent chemotherapy was most commonly capecitabine (82%). Sixty-three patients (63%) had surgery after CRT. The mean decline in FACT-G, HCS subscale, and FACT-Hep from pre- to post-CRT was 3.5 (standard deviation [SD], 13.7), 1.7 (SD 7.8), and 5.2 (SD 19.4), respectively. Each of these changes were statistically significant, but did not meet the minimally important difference threshold. Pancreatic head tumor location was associated with decline in FACT-Hep. Nausea was the toxicity with the greatest increase from pre- to post-CRT by both physician-assessment and patient-reported QOL.ConclusionsFor patients with intact pancreatic adenocarcinoma, modern CRT is well tolerated with minimal decline in QOL during treatment.  相似文献   
110.
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