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   2798485篇
  免费   194906篇
  国内免费   8074篇
耳鼻咽喉   36932篇
儿科学   91309篇
妇产科学   76614篇
基础医学   393125篇
口腔科学   75386篇
临床医学   251996篇
内科学   561233篇
皮肤病学   68272篇
神经病学   232711篇
特种医学   105561篇
外国民族医学   836篇
外科学   413129篇
综合类   51409篇
现状与发展   5篇
一般理论   1024篇
预防医学   215960篇
眼科学   60765篇
药学   202462篇
  8篇
中国医学   5998篇
肿瘤学   156730篇
  2021年   24309篇
  2019年   25040篇
  2018年   36137篇
  2017年   27088篇
  2016年   30715篇
  2015年   34501篇
  2014年   46407篇
  2013年   69329篇
  2012年   95224篇
  2011年   99785篇
  2010年   58834篇
  2009年   55437篇
  2008年   91651篇
  2007年   97356篇
  2006年   98005篇
  2005年   94248篇
  2004年   90190篇
  2003年   86690篇
  2002年   83314篇
  2001年   132018篇
  2000年   134987篇
  1999年   113832篇
  1998年   32301篇
  1997年   28790篇
  1996年   28962篇
  1995年   28080篇
  1994年   25667篇
  1993年   23977篇
  1992年   87165篇
  1991年   83433篇
  1990年   80574篇
  1989年   77665篇
  1988年   71018篇
  1987年   69469篇
  1986年   64912篇
  1985年   61832篇
  1984年   46001篇
  1983年   38829篇
  1982年   23051篇
  1981年   20433篇
  1979年   39902篇
  1978年   28113篇
  1977年   23895篇
  1976年   22041篇
  1975年   23490篇
  1974年   27610篇
  1973年   26207篇
  1972年   24548篇
  1971年   22723篇
  1970年   20957篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
86.
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients.  相似文献   
87.
88.
ABSTRACT: Background: Although increases in perinatal mortality risk associated with fetal macrosomia are well documented, the optimal route of delivery for fetuses with suspected macrosomia remains controversial. The objective of this investigation was to assess the risk of neonatal death among macrosomic infants delivered vaginally compared with those delivered by cesarean section. Methods: Data were derived from the U.S. 1995–1999 Linked Live Birth‐Infant Death Cohort files and term (37–44 wk), single live births to United States resident mothers selected. A proportional hazards model was used to analyze the risk of neonatal death associated with cesarean delivery among 3 categories of macrosomic infants (infants weighing 4,000–4,499 g; 4,500–4,999 g; and 5,000+ g). Results: After controlling for maternal characteristics and complications, the adjusted hazard ratio for neonatal death associated with cesarean delivery among the 3 categories of macrosomic infants was 1.40, 1.30, and 0.85. Conclusions: Although cesarean delivery may reduce the risk of death for the heaviest infants (5,000+ g), the relative benefit of this intervention for macrosomic infants weighing 4,000–4,999 g remains debatable. Thus, policies in support of prophylactic cesarean delivery for suspected fetal macrosomia may need to be reevaluated. (BIRTH 33:4 December 2006)  相似文献   
89.
90.
PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetic characteristics of doxorubicin encapsulated in a low temperature sensitive liposome (LTSL) when given concurrently with local hyperthermia to canine solid tumors. EXPERIMENTAL DESIGN: Privately owned dogs with solid tumors (carcinomas or sarcomas) were treated. The tumors did not involve bone and were located at sites amenable to local hyperthermia. LTSL-doxorubicin was given (0.7-1.0 mg/kg i.v.) over 30 minutes during local tumor hyperthermia in a standard phase I dose escalation study. Three treatments, given 3 weeks apart, were scheduled. Toxicity was monitored for an additional month. Pharmacokinetics were evaluated during the first treatment cycle. RESULTS: Twenty-one patients were enrolled: 18 with sarcomas and 3 with carcinomas. Grade 4 neutropenia and acute death secondary to liver failure, possibly drug related, were the dose-limiting toxicities. The maximum tolerated dose was 0.93 mg/kg. Other toxicities, with the possible exception of renal damage, were consistent with those observed following free doxorubicin administration. Of the 20 dogs that received > or = 2 doses of LTSL-doxorubicin, 12 had stable disease, and 6 had a partial response to treatment. Pharmacokinetic variables were more similar to those of free doxorubicin than the marketed liposomal product. Tumor drug concentrations at a dose of 1.0 mg/kg averaged 9.12 +/- 6.17 ng/mg tissue. CONCLUSION: LTSL-doxorubicin offers a novel approach to improving drug delivery to solid tumors. It was well tolerated and resulted in favorable response profiles in these patients. Additional evaluation in human patients is warranted.  相似文献   
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