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   5355篇
  免费   310篇
  国内免费   11篇
耳鼻咽喉   123篇
儿科学   238篇
妇产科学   199篇
基础医学   601篇
口腔科学   126篇
临床医学   526篇
内科学   1117篇
皮肤病学   144篇
神经病学   608篇
特种医学   653篇
外科学   571篇
综合类   89篇
一般理论   2篇
预防医学   227篇
眼科学   79篇
药学   142篇
肿瘤学   231篇
  2021年   57篇
  2020年   43篇
  2019年   41篇
  2018年   58篇
  2017年   63篇
  2016年   64篇
  2015年   67篇
  2014年   105篇
  2013年   237篇
  2012年   212篇
  2011年   192篇
  2010年   118篇
  2009年   113篇
  2008年   176篇
  2007年   211篇
  2006年   210篇
  2005年   167篇
  2004年   184篇
  2003年   158篇
  2002年   155篇
  2001年   162篇
  2000年   129篇
  1999年   140篇
  1998年   71篇
  1997年   53篇
  1996年   80篇
  1995年   64篇
  1994年   50篇
  1993年   48篇
  1992年   110篇
  1991年   111篇
  1990年   128篇
  1989年   121篇
  1988年   118篇
  1987年   140篇
  1986年   154篇
  1985年   119篇
  1984年   94篇
  1983年   94篇
  1982年   66篇
  1981年   60篇
  1980年   53篇
  1979年   79篇
  1978年   66篇
  1977年   63篇
  1976年   44篇
  1975年   41篇
  1974年   61篇
  1973年   45篇
  1969年   40篇
排序方式: 共有5676条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Ohne ZusammenfassungVortrag, gehalten in der Dermatologen-Vereinigung des rheinischwestphälischen Industriebezirks in Düsseldorf am 28. April 1901.  相似文献   
85.
The ACR Dose Index Registry (DIR) provides a new source of clinical radiation exposure data that has not been used previously to establish or update the relative radiation level (RRL) values in the ACR Appropriateness Criteria (AC). The results of a recent review of DIR data for 10 common CT examinations were compared with current ACR AC RRL values for the same procedures. The AC RRL values were previously determined by consensus of members of the AC Radiation Exposure Subcommittee based on reference radiation dose values from the literature (when available) and anecdotal information from individual members’ clinical practices and experiences. For 7 of the 10 examination types reviewed, DIR data agreed with existing RRL values. For 3 of 10 examination types, DIR data reflected lower dose values than currently rated in the AC. The Radiation Exposure Subcommittee will revise these RRL assignments in a forthcoming update to the AC (in October 2018) and will continue to monitor the DIR and associated reviews and analyses to refine RRL assignments for additional examination types. Given recent attention and efforts to reduce radiation exposure in CT and other imaging modalities, it is likely that other examination types will require revision of RRL assignments once information from the DIR database is considered.  相似文献   
86.
The treatment of patients with recurrent glioblastoma remains a major oncologic problem, with median survival after progression of 7–9 months. To determine the maximum tolerated dose and dose-limiting toxicity (DLT), the combination of dasatinib and cyclonexyl-chloroethyl-nitrosourea (CCNU) was investigated in this setting. The study was designed as multicenter, randomized phase II trial, preceded by a lead-in safety phase. The safety component reported here, which also investigated pharmacokinetics and preliminary clinical activity, required expansion and is therefore considered a phase I part to establish a recommended dosing regimen of the combination of CCNU (90–110 mg/m2) and dasatinib (100–200 mg daily). Overall, 28 patients were screened, and 26 patients were enrolled. Five dose levels were explored. DLTs, mainly myelosuppression, occurred in 10 patients. Grade 3 or 4 neutropenia was recorded in 7 patients (26.9%) and thrombocytopenia in 11 patients (42.3%). No significant effect of CCNU coadministration on dasatinib pharmacokinetics was found. Median progression-free survival (PFS) was 1.35 months (95% confidence interval: 1.2–1.4) and 6-month PFS was 7.7%. In this phase I study of recurrent glioblastoma patients, the combination of CCNU and dasatinib showed significant hematological toxicities and led to suboptimal exposure to both agents.  相似文献   
87.
88.
89.
Objective. We were aware of a small number of cases in our EMS system where patients in respiratory distress had a worsening of their condition after being removed from the home on a Reeves® stretcher (RS). We sought to determine if this prehospital lifting device causes additional respiratory effort used in normal subjects by describing changes in heart rate, pulse oximetry, tidal volume, minute ventilation, andrespiratory rate. Methods. Forty-nine subjects were entered into this study. Data were collected while the subject was supine on the floor in the RS andonce while suspended over the floor in the device. A randomized crossover design was used. Ten subjects were excluded because of inadvertent omission of a nose plug during spirometry. Data points were recorded in the final minute of a 3-minute exposure. Three minutes was chosen to simulate a prehospital transport time from the scene to the ambulance. Minute ventilation, tidal volume, heart rate, pulse oximetry, andrespiratory rate were recorded for each subject during each phase. Subjects were also asked to rate the difficulty of breathing using the modified Borg scale. Results. Data were obtained for 39 subjects. The mean respiratory rate while suspended was 9.9 ± 3.0 breaths per minute compared to 9.1 ± 2.5 breaths per minutes supine on the floor (p = 0.007). The mean minute ventilation while suspended in a RS was 8.17 ± 3.25 L/min versus 7.37 ± 2.37 while lying flat (p = 0.03). There was no difference in tidal volume, heart rate, pulse oximetry, or subjective modified Borg scale ratings. Conclusions. Subjects suspended in a RS for 3 minutes had statistically higher respiratory rates andminute ventilation than the same subjects lying flat. Although these modest changes are clinically insignificant in normal subjects, they could present a significant challenge to subjects in respiratory distress.  相似文献   
90.
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