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   442145篇
  免费   30890篇
  国内免费   7578篇
耳鼻咽喉   5559篇
儿科学   8888篇
妇产科学   10913篇
基础医学   61153篇
口腔科学   12863篇
临床医学   38753篇
内科学   87482篇
皮肤病学   9227篇
神经病学   30576篇
特种医学   16208篇
外国民族医学   123篇
外科学   66952篇
综合类   21441篇
现状与发展   18篇
一般理论   66篇
预防医学   21315篇
眼科学   11178篇
药学   37888篇
  74篇
中国医学   5782篇
肿瘤学   34154篇
  2021年   6062篇
  2020年   4179篇
  2019年   5021篇
  2018年   6804篇
  2017年   5399篇
  2016年   5477篇
  2015年   7046篇
  2014年   9505篇
  2013年   10511篇
  2012年   14627篇
  2011年   15673篇
  2010年   9358篇
  2009年   8224篇
  2008年   12747篇
  2007年   13643篇
  2006年   13691篇
  2005年   12629篇
  2004年   10936篇
  2003年   10648篇
  2002年   9954篇
  2001年   29669篇
  2000年   30308篇
  1999年   25419篇
  1998年   6310篇
  1997年   5508篇
  1996年   4800篇
  1995年   4347篇
  1994年   3857篇
  1993年   3314篇
  1992年   16555篇
  1991年   15254篇
  1990年   14542篇
  1989年   14277篇
  1988年   12848篇
  1987年   12251篇
  1986年   11278篇
  1985年   10443篇
  1984年   6986篇
  1983年   5642篇
  1982年   2731篇
  1979年   5505篇
  1978年   3345篇
  1977年   2963篇
  1975年   2636篇
  1974年   3064篇
  1973年   2863篇
  1972年   2828篇
  1971年   2773篇
  1970年   2509篇
  1969年   2543篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
52.
53.
54.
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   
55.
56.
随着腔镜技术的进一步发展以及微创理念应用于结直肠外科疾病的诊治中,结直肠相关疾病的诊治发生了翻天覆地的变化。由传统的经腹手术到腹腔镜手术、经自然腔道手术,再到经自然腔道取标本手术(NOSES),结直肠疾病的外科诊治在微创领域取得了巨大成果。NOSES技术是目前结直肠外科在微创领域前沿的手术方式之一,它通过经直肠、阴道取标本来避免了腹壁的辅助取标本切口,从而将结直肠外科手术进一步微创化。NOSES技术集传统腹腔镜手术的优势与现代微创外科的理念于一体,它在确保手术效果的基础上集中体现了微创、加速康复外科、功能外科、"无疤"等理念的特点。本文主要就国内外各中心开展NOSES技术在结直肠外科诊治开展中的相关经验、心得和体会进行综述。  相似文献   
57.
58.
59.
By means of the ultrasonic surface impact (amplitude of 30 μm, strike number of 48,000 times/mm2), nanograins have been achieved in the surfaces of both Ti6Al4V(TC4) and Ti3Zr2Sn3Mo25Nb(TLM) titanium alloys, mainly because of the dislocation motion. Many mechanical properties are improved, such as hardness, residual stress, and roughness. The rotating–bending fatigue limits of TC4 and TLM subjected to ultrasonic impact are improved by 13.1% and 23.7%, separately. Because of the bending fatigue behavior, which is sensitive to the surface condition, cracks usually initiate from the surface defects under high stress amplitude. By means of an ultrasonic impact tip with the size of 8 mm, most of the inner cracks present at the zone with a depth range of 100~250 μm in the high life region. The inner crack core to TC4 usually appears as a deformed long and narrow α-phase, while the cracks in TLM specimens prefer to initiate at the triple grain boundary junctions. This zone crosses the grain refined layer and the deformed coarse grain layer. With the gradient change of elastic parameters, the model shows an increase of normal stress at this zone. Combined with the loss of plasticity and toughness, it is easy to understand these fatigue behaviors.  相似文献   
60.
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