全文获取类型
收费全文 | 4242篇 |
免费 | 204篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 65篇 |
妇产科学 | 28篇 |
基础医学 | 153篇 |
口腔科学 | 18篇 |
临床医学 | 716篇 |
内科学 | 413篇 |
皮肤病学 | 14篇 |
神经病学 | 131篇 |
特种医学 | 50篇 |
外科学 | 524篇 |
综合类 | 545篇 |
预防医学 | 1252篇 |
眼科学 | 8篇 |
药学 | 476篇 |
1篇 | |
中国医学 | 24篇 |
肿瘤学 | 44篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 67篇 |
2021年 | 94篇 |
2020年 | 127篇 |
2019年 | 90篇 |
2018年 | 101篇 |
2017年 | 72篇 |
2016年 | 87篇 |
2015年 | 139篇 |
2014年 | 266篇 |
2013年 | 312篇 |
2012年 | 376篇 |
2011年 | 364篇 |
2010年 | 313篇 |
2009年 | 249篇 |
2008年 | 201篇 |
2007年 | 190篇 |
2006年 | 160篇 |
2005年 | 128篇 |
2004年 | 109篇 |
2003年 | 76篇 |
2002年 | 68篇 |
2001年 | 57篇 |
2000年 | 67篇 |
1999年 | 63篇 |
1998年 | 32篇 |
1997年 | 51篇 |
1996年 | 38篇 |
1995年 | 74篇 |
1994年 | 38篇 |
1993年 | 43篇 |
1992年 | 48篇 |
1991年 | 65篇 |
1990年 | 52篇 |
1989年 | 40篇 |
1988年 | 62篇 |
1987年 | 31篇 |
1986年 | 21篇 |
1985年 | 26篇 |
1984年 | 15篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
排序方式: 共有4483条查询结果,搜索用时 15 毫秒
11.
112例脑动脉系统微栓子监测的临床研究 总被引:1,自引:1,他引:0
目的 研究脑动脉系统微栓子 (MES)的产生机制及其相关因素。方法 将 112例 MES监测的临床资料进行总结分析。结果 本组微栓子检出率为 33.93% ,且全部见于有明显脑卒中症状者 ;脑梗死 MES检出率为35 .87%且以原发性大面积梗死为主 ;MES阳性与病程有明显相关 ,病程 <72 h易检出微栓子 ,阳性率为 4 7.72 % ;颅内血管狭窄是微栓子产生的主要原因 ;颈动脉异常与正常组微栓子出现率无明显差异 ,但发现本组病例中微栓子出现以左侧为主 ,与颈动脉病变部位一致率为 5 5 .5 5 % ;确定微栓子来源于有病变的颅外颈动脉 2例 ,来源于有病变的颅内颈动脉系 5例 ,来源于同时伴有颅内外血管病变 12例 ,表明颅内外动脉同时伴有病变时微栓子检出率增高 ;MES的阳性率与血液成分无相关性 ,但在血液成分异常组中血粘度增高以及血小板聚集降低 MES阳性率明显增高。结论 脑动脉系统中监测到微栓子说明患者有活动的栓子来源 ,易发生或复发脑梗死 ,TCD能正确的监测、判断脑循环中微栓子 ,确定其发生率、性质、来源以及与疾病的联系 相似文献
12.
Specific factors have limited the interpretation of studies regarding the efficacy, effectiveness and efficiency of technology in anaesthesia. Some of these problems are reviewed, including the lack of specific outcomes necessitating the use of intermediate measures (e.g., hypoxaemia, myocardial ischaemia), which are not necessarily related to ultimate patient outcomes. This emphasizes the need for anaesthesia investigators to define fundamental issues specifically and design studies accordingly. With respect to anaesthesia monitors, the “lead time” or early warning provided by a monitor relative to that required to alter therapy effectively needs to be defined better and compared with the “lead time” without the monitor. After defining the benefit of a monitor, investigators should analyze the cost relative to alternatives (cost-benefit and cost-effectiveness). A hierarchical model to guide technology assessment is presented that addresses in order, the scientific basis of the technology, and the influence on the patient followed by societal issues. Anaesthetists have relied on traditional methods of technology assessment adopted from other disciplines. These methodologies do not address specific issues related to anaesthesia practice (such as “lead time”). In defining problems specific to the specialty of anaesthesia, new outcome measures that focus on the human factors related to decision-making in the operating room need to be developed. Future evaluations of anaesthesia technology require innovative approaches that address specific anaesthesia-related problems. One such approach is the use of simulation-based studies of response patterns to critical incidents. 相似文献
13.
Dr Arthur J. L. Schneider MD W. Bosseau Murray MBChB MD Steven C. Mentzer BS Fernando Miranda BS Sorin Vaduva MS 《Journal of clinical monitoring and computing》1995,11(6):358-364
Objective. The medical practitioner is faced with an increasing list of protocols and algorithms related to patient care. These recommendations are often difficult to recall, particularly in stressful emergency situations. Using advanced cardiac life support (ACLS) protocols, we built a computer-based system to exhibit precompiled response plans for medical emergencies. To validate the usefulness of this prompting device, we tested application of two of the nine ACLS algorithms, pulseless ventricular fibrillation/ventricular tachycardia (Vfib/Vtach) and bradycardia, in a simulated operating room (OR) environment.Methods. The system utilized the software authoring system IconAuthor (Aimtec Inc., Nashua, NH) and a touch-screen monitor (DiamondScan, Microtouch, Methuen, MA). Prior to testing our system, all 39 subjects were given time to familiarize themselves with its operation. Subsequently, all subjects were videotaped while managing a standard simulated anesthetic. During the anesthetic, the subjects were presented with two emergency scenarios, not viewed during the familiarization period. The electrocardiographic (EKG) signals for normal sinus rhythm, ventricular fibrillation, and second-degree heart block were presented. By random selection, the prompter was available to half of the subjects for help with arrhythmia management (experimental group), while to half it was not (control group).Results. A total of 39 subjects completed the exercise. Use of the prompter enabled significantly more subjects to administer correct drugs and dosages during ventricular fibrillation. The correct lidocaine dose was chosen more often by the experimental group than by the control (p=0.015); similarly MgSO4 was appropriately ordered more often in the experimental group (p=0.003). During second-degree heart block, atropine was correctly followed with a dopamine infusion (p=0.004), and epinephrine infusion was ordered for refractory bradycardia (p=0.002) more often in the experimental than the control group.Conclusions. These data demonstrate the value of a prompting device at the anesthesia workstation. We foresee the use of such prompters in many areas of medicine.This study was made possible by a grant from the Anesthesia Patient Safety Foundation. Results were presented, in part, at the meeting of the STA/SEA Orlando, Florida, January 1994. 相似文献
14.
To study the effect of vascularized fibulargraft on large defects of long bones and the monitoringmethod for the vascular status of the grafted fibula. 相似文献
15.
16.
Experimental studies demonstrated a severe cardiac load of the CO2 pneumoperitoneum caused by an accelerated after- and a decreased preload. Patients displaying cardiovascular risks are therefore
often rejected from laparoscopic surgery. Hence, the pathophysiological changes and the intraoperative risk of the CO2 pneumoperitoneum in high-risk cardiopulmonary patients (NYHA II–III, n= 15) undergoing laparoscopic cholecystectomy are described. The changes in cardiac after- and preload seem to be due to the
elevated intraabdominal pressure rather than transperitoneally resorbed CO2 and are reversible by desufflation. In one patient conversion to open operation had to be performed because of a severe drop
in cardiac output and right ventricle ejection fraction. Mixed oxygen saturation was predicting intraoperative worsening in
this case. The described pathophysiological changes may seem to be well tolerated even in high-risk cardiac patients. Monitoring
of hemodynamics should include an arterial catheter line and blood gas analyses. Pharmacologic interventions or pressureless
laparoscopic procedures might not be necessary as long as laparoscopic cholecystectomy is performed.
Received: 13 December 1996/Accepted: 8 January 1997 相似文献
17.
Auditory evoked potential index: a quantitative measure of changes in auditory evoked potentials during general anaesthesia 总被引:30,自引:0,他引:30
We describe a novel index derived from the auditory evoked potential, the auditory evoked potential index, and we compare it with latencies and amplitudes related to clinical signs of consciousness and unconsciousness. Eleven patients, scheduled for total knee replacement under spinal anaesthesia, completed the study. The initial mean (SD) value of the auditory evoked potential index was 72.5 (11.2). During the first period of unconsciousness it decreased to 39.6 (6.9) and returned to 66.8 (12.5) when patients regained consciousness. Thereafter, similar values were obtained whenever patients lost and regained consciousness. Latencies and amplitudes changed in a similar fashion. From all parameters studied, Na latencies had the greatest overlap between successive awake and asleep states. The auditory evoked potential index and Nb latencies had no overlap. The consistent changes demonstrated suggest that the auditory evoked potential index could be used as a reliable indicator of potential awareness during propofol anaesthesia instead of latencies and amplitudes. 相似文献
18.
Sidestream versus mainstream carbon dioxide analyzers 总被引:1,自引:0,他引:1
19.
The extensometer is a new device with potential in the field of respiratory pattern analysis. This paper describes the physical principles upon which the extensometer depends and also assesses its performance as a noninvasive respiratory monitor in respect of its ability to measure tidal volume and to determine obstructive breathing patterns in awake volunteers in the supine position over a limited time period. Further developments of the device are outlined and the current status of torso transducers in anaesthesia and intensive care are discussed. 相似文献
20.
利用单光子发射型计算机断层显象仪监测移植肾功能25例,计34例次。观察表明,在肾移植早期,SPECT有利于鉴别少层原因,避免冒然切除移植肾;肾移植后期,如有肾功能减退,肾小球滤过率的降低较肌酐升高更敏感,更准确,故SPECT监测是了解肾功能及判断预后的最佳方法之一。 相似文献