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   1464642篇
  免费   95217篇
  国内免费   1990篇
耳鼻咽喉   19520篇
儿科学   49242篇
妇产科学   41103篇
基础医学   207237篇
口腔科学   36969篇
临床医学   120853篇
内科学   284845篇
皮肤病学   27315篇
神经病学   116417篇
特种医学   59239篇
外国民族医学   366篇
外科学   229818篇
综合类   29207篇
现状与发展   1篇
一般理论   302篇
预防医学   111114篇
眼科学   31777篇
药学   107908篇
  1篇
中国医学   3119篇
肿瘤学   85496篇
  2018年   34375篇
  2017年   27001篇
  2016年   31193篇
  2015年   12593篇
  2014年   16809篇
  2013年   25144篇
  2012年   40435篇
  2011年   57320篇
  2010年   40104篇
  2009年   31939篇
  2008年   55905篇
  2007年   62103篇
  2006年   39080篇
  2005年   40553篇
  2004年   40743篇
  2003年   41317篇
  2002年   38603篇
  2001年   58537篇
  2000年   60310篇
  1999年   50967篇
  1998年   14525篇
  1997年   13168篇
  1996年   13238篇
  1995年   12522篇
  1994年   11963篇
  1993年   11025篇
  1992年   41110篇
  1991年   40533篇
  1990年   40069篇
  1989年   38848篇
  1988年   36231篇
  1987年   35478篇
  1986年   33829篇
  1985年   32240篇
  1984年   23998篇
  1983年   20896篇
  1982年   12475篇
  1981年   10946篇
  1979年   22728篇
  1978年   15947篇
  1977年   13755篇
  1976年   13032篇
  1975年   14210篇
  1974年   16723篇
  1973年   16086篇
  1972年   15320篇
  1971年   14235篇
  1970年   13251篇
  1969年   12773篇
  1968年   12010篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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   
72.
73.
74.
75.
76.
77.
78.
79.
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   
80.
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