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   184743篇
  免费   34320篇
  国内免费   2791篇
耳鼻咽喉   5688篇
儿科学   5695篇
妇产科学   2880篇
基础医学   9162篇
口腔科学   2394篇
临床医学   29349篇
内科学   53896篇
皮肤病学   8817篇
神经病学   17242篇
特种医学   8874篇
外国民族医学   1篇
外科学   45118篇
综合类   417篇
现状与发展   72篇
一般理论   5篇
预防医学   8594篇
眼科学   4072篇
药学   4606篇
中国医学   519篇
肿瘤学   14453篇
  2024年   700篇
  2023年   5007篇
  2022年   2056篇
  2021年   4444篇
  2020年   6608篇
  2019年   3028篇
  2018年   8369篇
  2017年   8154篇
  2016年   9617篇
  2015年   10051篇
  2014年   17371篇
  2013年   17778篇
  2012年   8803篇
  2011年   8707篇
  2010年   12154篇
  2009年   15794篇
  2008年   7955篇
  2007年   6032篇
  2006年   8222篇
  2005年   5393篇
  2004年   4268篇
  2003年   3067篇
  2002年   3019篇
  2001年   4590篇
  2000年   3731篇
  1999年   3723篇
  1998年   3837篇
  1997年   3592篇
  1996年   3467篇
  1995年   3285篇
  1994年   2030篇
  1993年   1635篇
  1992年   1516篇
  1991年   1555篇
  1990年   1227篇
  1989年   1304篇
  1988年   1130篇
  1987年   959篇
  1986年   972篇
  1985年   776篇
  1984年   587篇
  1983年   557篇
  1982年   540篇
  1981年   435篇
  1980年   371篇
  1979年   330篇
  1978年   350篇
  1977年   419篇
  1975年   295篇
  1972年   318篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Introduction: Opioid-induced rigidity often makes bag-mask ventilation difficult or impossible during induction of anesthesia. Difficult ventilation may result from chest wall rigidity, upper airway closure, or both. This study further defines the contribution of vocal cord closure to this phenomenon.

Methods: With institutional review board approval, 30 patients undergoing elective cardiac surgery participated in the study. Morphine (0.1 mg/kg) and scopolamine (6 micro gram/kg) given intramuscularly provided sedation along with intravenous midazolam as needed. Lidocaine 10% spray provided topical anesthesia of the oropharynx. A fiberoptic bronchoscope positioned in the airway photographed the glottis before induction of anesthesia. A second photograph was obtained after induction with 3 micro gram/kg sufentanil administered during a period of 2 min. A mechanical ventilator provided 10 ml/kg breaths at 10/min via mask and oral airway with jaw thrust. A side-stream spirometer captured objective pulmonary compliance data. Subjective airway compliance was scored. Pancuronium (0.1 mg/kg) provided muscle relaxation. One minute after the muscle relaxant was given, a third photograph was taken and compliance measurements and scores were repeated. Photographs were scored in a random, blinded manner by one investigator. Wilcoxon signed rank tests compared groups, with Bonferroni correction. Differences were considered significant at P <0.05.

Results: Twenty-eight of 30 patients exhibited decreased pulmonary compliance and closed vocal cords after opioid induction. Two patients with neither objective nor subjective changes in pulmonary compliance had open vocal cords after opioid administration. Both subjective and objective compliances increased from severely compromised values after narcotic-induced anesthesia to normal values (P = 0.000002) after patients received a relaxant. Photo scores document open cords before induction, progressing to closed cords after the opioid (P = 0.00002), and opening again after a relaxant was administered (P = 0.00005).  相似文献   

992.
993.
994.
Nonoperative treatment is generally the choice for Type I and II acromioclavicular (AC) joint injuries. The situation issomewhat more controversial when Type III AC dislocations are considered, particularly with respect to athletes and heavy laborers. A number of recent studies have supported conservative treatment in these groups. There is general consensus as to the need for surgical intervention for Type IV, V, and VI AC injuries. Integral to any form of management, nonoperative or operative, is a rehabilitation program that addresses range of motion, strength, and neuromuscular control. We describe our program, which is divided into four phases: (1) Pain control and immediate protected range of motion and isometric exercises; (2) strengthening exercises using isotonic contractions and proprioceptive neuromuscular facilitation (PNF) exercises; (3) Unrestricted functional participation with the goal of increasing strength, power, endurance, and neuromuscular control; and (4) return to activity with sport specific functional drills. An athlete is ready to return to competitive sports once the following criteria are met: full range of motion (ROM), no pain or tenderness, satisfactory clinical exam, and demonstration of adequate strength on isokinetic testing. The unique considerations in a throwing athlete with an AC injury are also addressed. The primary goal of the nonoperative treatment protocol is to return the athlete to full activities as quickly and as safely as possible.  相似文献   
995.
996.
997.
998.
999.
A case is presented of a 16-year-old girl with ectodermal dysplasia for whom dental surgery under general anaesthesia was planned. Following a priming dose of vecuronium, and immediately after injection of sodium thiopentone (5 mg·kg−1) pulmonary aspiration of gastric contents occurred. It is hypothesized that, because of the rapid speed of onset of neuromuscular blocking agents on the laryngeal muscles, that partial laryngeal paralysis was present at the time of induction of anaesthesia and that this was responsible in part for the episode of pulmonary aspiration.  相似文献   
1000.
Perceptions of family cohesion and hierarchy structures were assessed by theFamily System Test (FAST), a clinically-derived figure placement technique. Parents (N=140) and their preadolescent offspring (N=70) completed typical and conflict representations in individual as well as group settings. Typical representations were characterized by balanced family structures (i.e. cohesive and moderately hierarchical) and those displaying conflict situations showed predominantly unbalanced patterns. FAST portrayals were related to respondent (mother vs. father vs. child). Fathers represented typical family relations as balanced more often than mothers. Regarding conflict representations, children were more likely than fathers to portray the family as unbalanced. However, analyses of representations of the same family (i.e. intra-family comparisons) indicated that all respondents differed in their perceptions and, that fathers' typical portrayals showed most often the same structure as those done by the family members as a group.  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