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   969845篇
  免费   71756篇
  国内免费   1430篇
耳鼻咽喉   13346篇
儿科学   25415篇
妇产科学   24221篇
基础医学   138674篇
口腔科学   29141篇
临床医学   85585篇
内科学   190208篇
皮肤病学   19686篇
神经病学   75984篇
特种医学   38265篇
外国民族医学   135篇
外科学   157040篇
综合类   18908篇
现状与发展   1篇
一般理论   275篇
预防医学   66326篇
眼科学   22329篇
药学   75466篇
  3篇
中国医学   2183篇
肿瘤学   59840篇
  2018年   9595篇
  2017年   7518篇
  2016年   8298篇
  2015年   9415篇
  2014年   12845篇
  2013年   18851篇
  2012年   25853篇
  2011年   26851篇
  2010年   15901篇
  2009年   15231篇
  2008年   26353篇
  2007年   27442篇
  2006年   28245篇
  2005年   27156篇
  2004年   26293篇
  2003年   25137篇
  2002年   24665篇
  2001年   55882篇
  2000年   57809篇
  1999年   48056篇
  1998年   11256篇
  1997年   9917篇
  1996年   9984篇
  1995年   9334篇
  1994年   8649篇
  1993年   7937篇
  1992年   36343篇
  1991年   34807篇
  1990年   33578篇
  1989年   32687篇
  1988年   29826篇
  1987年   28970篇
  1986年   26988篇
  1985年   25832篇
  1984年   18398篇
  1983年   15626篇
  1982年   8126篇
  1981年   7080篇
  1979年   16318篇
  1978年   11046篇
  1977年   9431篇
  1976年   8215篇
  1975年   8955篇
  1974年   10853篇
  1973年   10237篇
  1972年   9691篇
  1971年   9148篇
  1970年   8710篇
  1969年   8194篇
  1968年   7501篇
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
51.
52.
53.
Journal of Thrombosis and Thrombolysis - Amniotic fluid embolism (AFE) is a catastrophic condition in the peripartum period and still remains as a leading cause of maternal death. Although over 80%...  相似文献   
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.
The retroviral protease of human immunodeficiency virus (HIV) is an excellent target for antiviral inhibitors for treating HIV/AIDS. Despite the efficacy of therapy, current efforts to control the disease are undermined by the growing threat posed by drug resistance. This review covers the historical background of studies on the structure and function of HIV protease, the subsequent development of antiviral inhibitors, and recent studies on drug-resistant protease variants. We highlight the important contributions of Dr. Stephen Oroszlan to fundamental knowledge about the function of the HIV protease and other retroviral proteases. These studies, along with those of his colleagues, laid the foundations for the design of clinical inhibitors of HIV protease. The drug-resistant protease variants also provide an excellent model for investigating the molecular mechanisms and evolution of resistance.  相似文献   
56.
57.
58.
59.
We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6?×?3.3?×?3.8 cm) extending from the superior mucosal lip of Bauhin’s valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20–50 % of all underlying causes are malignant, explorative surgery is favored in adults.  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