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   1350140篇
  免费   99058篇
  国内免费   2681篇
耳鼻咽喉   19115篇
儿科学   44561篇
妇产科学   39600篇
基础医学   197229篇
口腔科学   37144篇
临床医学   114413篇
内科学   267462篇
皮肤病学   28081篇
神经病学   106263篇
特种医学   52959篇
外国民族医学   386篇
外科学   207782篇
综合类   28056篇
现状与发展   2篇
一般理论   343篇
预防医学   97393篇
眼科学   30275篇
药学   103759篇
  4篇
中国医学   2964篇
肿瘤学   74088篇
  2018年   13508篇
  2016年   11479篇
  2015年   13264篇
  2014年   18183篇
  2013年   27472篇
  2012年   37719篇
  2011年   40277篇
  2010年   24065篇
  2009年   22507篇
  2008年   38686篇
  2007年   41855篇
  2006年   42214篇
  2005年   41303篇
  2004年   40137篇
  2003年   38959篇
  2002年   38540篇
  2001年   60598篇
  2000年   61926篇
  1999年   52571篇
  1998年   15075篇
  1997年   13517篇
  1996年   13703篇
  1995年   12901篇
  1994年   12303篇
  1993年   11350篇
  1992年   42120篇
  1991年   41479篇
  1990年   40842篇
  1989年   39662篇
  1988年   36947篇
  1987年   36111篇
  1986年   34477篇
  1985年   32829篇
  1984年   24456篇
  1983年   21271篇
  1982年   12695篇
  1981年   11207篇
  1979年   23038篇
  1978年   16148篇
  1977年   13993篇
  1976年   13190篇
  1975年   14496篇
  1974年   17053篇
  1973年   16428篇
  1972年   15627篇
  1971年   14525篇
  1970年   13476篇
  1969年   12984篇
  1968年   12226篇
  1967年   10714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