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   30531篇
  免费   1593篇
  国内免费   351篇
耳鼻咽喉   54篇
儿科学   872篇
妇产科学   253篇
基础医学   2117篇
口腔科学   38篇
临床医学   6369篇
内科学   9826篇
皮肤病学   57篇
神经病学   448篇
特种医学   1330篇
外国民族医学   1篇
外科学   3853篇
综合类   3545篇
预防医学   1099篇
眼科学   28篇
药学   1731篇
  14篇
中国医学   364篇
肿瘤学   476篇
  2023年   455篇
  2022年   767篇
  2021年   1152篇
  2020年   1053篇
  2019年   1119篇
  2018年   1091篇
  2017年   950篇
  2016年   890篇
  2015年   1066篇
  2014年   2264篇
  2013年   2014篇
  2012年   1712篇
  2011年   1860篇
  2010年   1534篇
  2009年   1505篇
  2008年   1480篇
  2007年   1405篇
  2006年   1279篇
  2005年   1042篇
  2004年   912篇
  2003年   719篇
  2002年   631篇
  2001年   490篇
  2000年   453篇
  1999年   429篇
  1998年   351篇
  1997年   348篇
  1996年   309篇
  1995年   264篇
  1994年   277篇
  1993年   247篇
  1992年   208篇
  1991年   183篇
  1990年   136篇
  1989年   136篇
  1988年   160篇
  1987年   117篇
  1986年   95篇
  1985年   150篇
  1984年   174篇
  1983年   102篇
  1982年   119篇
  1981年   110篇
  1980年   112篇
  1979年   85篇
  1978年   67篇
  1977年   75篇
  1976年   83篇
  1975年   74篇
  1973年   59篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
A 25-year-old, emaciated man without medical treatment was found to have died suddenly at home by his mother. At autopsy, there were no injuries to his body, but significant circulatory insufficiency was observed. Electron microscopy revealed abnormal mitochondria in cells of the cardiac conduction system. The conduction system was filled with mitochondrial size abnormalities and mitochondrial cristae abnormalities. No notable abnormal findings were observed in other organs. Genetic examination of the blood revealed the mitochondrial pathogenetic variant m.3243A>G. Epileptic seizures, diabetic ketoacidosis, and hyperosmolar hyperglycemic state were unlikely to be the cause of sudden death. The cause of death was diagnosed as arrhythmia possibly induced by the failure of the cardiac conduction system due to mitochondrial disease. This is a rare case of sudden death caused by an accumulation of abnormal mitochondria in the cardiac conduction system.  相似文献   
2.
The purpose of this study is to show a very rare complication of acute cocaine poisoning, namely heart rupture. In the present case report, acute cocaine intoxication caused massive myocardial infarction, resulting in heart rupture and cardiac tamponade. A crime scene investigation found a dead body on the street in a drug dealing district. Examination of the body showed no external injuries. A thorough autopsy was performed showing massive cardiac tamponade with 510 ml of blood within the pericardium and full-thickness tissue lesion at the posterior wall of the left ventricle of 3.5 × 3 cm. Histological examination in hematoxylin and eosin was performed and confirmed the interruption of the posterior wall of the left ventricle with the presence of blood. In fact, although the correlation between cocaine and myocardial damage is well established, the relationship between heart rupture and acute cocaine intoxication is an extremely rare event. Moreover, since there are, to date, few reports of similar deaths, our report provides useful information regarding sudden death in a cocaine abuser. It is, therefore, of crucial importance to report this case to the scientific community.  相似文献   
3.
4.
5.
6.

Objectives

Expedient extubation after cardiac surgery has been associated with improved outcomes, leading to postoperative extubation frequently during overnight hours. However, recent evidence in a mixed medical-surgical intensive care unit population demonstrated worse outcomes with overnight extubation. This study investigated the impact of overnight extubation in a statewide, multicenter Society of Thoracic Surgeons database.

Methods

Records from 39,812 patients undergoing coronary artery bypass grafting or valve operations (2008-2016) and extubated within 24 hours were stratified according to extubation time between 06:00 and 18:00 (day) or between 18:00 and 6:00 (overnight). Outcomes including reintubation, mortality, and composite morbidity-mortality were evaluated using hierarchical regression models adjusted for Society of Thoracic Surgeons predictive risk scores. To further analyze extubation during the night, a subanalysis stratified patients into 3 groups: 06:00 to 18:00, 18:00 to 24:00, and 24:00 to 06:00.

Results

A total of 20,758 patients were extubated overnight (52.1%) and were slightly older (median age 66 vs 65 years, P < .001) with a longer duration of ventilation (4 vs 7 hours, P < .001). Day and overnight extubation were associated with equivalent operative mortality (1.7% vs 1.7%, P = .880), reintubation (3.7% vs 3.4%, P = .141), and composite morbidity-mortality (8.2% vs 8.0%, P = .314). After risk adjustment, overnight extubation was not associated with any difference in reintubation, mortality, or composite morbidity-mortality. On subanalysis, those extubated between 24:00 and 06:00 exhibited increased composite morbidity-mortality (odds ratio, 1.18; P = .001) but no difference in reintubation or mortality.

Conclusions

Extubation overnight was not associated with increased mortality or reintubation. These results suggest that in the appropriate clinical setting, it is safe to routinely extubate cardiac surgery patients overnight.  相似文献   
7.

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

Case report

A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.

Conclusion

Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma.  相似文献   
8.
9.
10.
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