全文获取类型
收费全文 | 2707765篇 |
免费 | 196686篇 |
国内免费 | 7275篇 |
专业分类
耳鼻咽喉 | 35356篇 |
儿科学 | 89055篇 |
妇产科学 | 73585篇 |
基础医学 | 388920篇 |
口腔科学 | 77308篇 |
临床医学 | 252761篇 |
内科学 | 522824篇 |
皮肤病学 | 58309篇 |
神经病学 | 216209篇 |
特种医学 | 100253篇 |
外国民族医学 | 592篇 |
外科学 | 396107篇 |
综合类 | 61884篇 |
现状与发展 | 5篇 |
一般理论 | 959篇 |
预防医学 | 215271篇 |
眼科学 | 62817篇 |
药学 | 198979篇 |
12篇 | |
中国医学 | 6736篇 |
肿瘤学 | 153784篇 |
出版年
2021年 | 21118篇 |
2019年 | 22138篇 |
2018年 | 31727篇 |
2017年 | 24019篇 |
2016年 | 26325篇 |
2015年 | 30008篇 |
2014年 | 41683篇 |
2013年 | 62479篇 |
2012年 | 86212篇 |
2011年 | 91178篇 |
2010年 | 53757篇 |
2009年 | 49907篇 |
2008年 | 84146篇 |
2007年 | 89354篇 |
2006年 | 89937篇 |
2005年 | 86303篇 |
2004年 | 82755篇 |
2003年 | 78761篇 |
2002年 | 76305篇 |
2001年 | 131481篇 |
2000年 | 134909篇 |
1999年 | 112412篇 |
1998年 | 30814篇 |
1997年 | 27201篇 |
1996年 | 27143篇 |
1995年 | 25942篇 |
1994年 | 24045篇 |
1993年 | 22341篇 |
1992年 | 87007篇 |
1991年 | 84438篇 |
1990年 | 81357篇 |
1989年 | 77870篇 |
1988年 | 71499篇 |
1987年 | 69858篇 |
1986年 | 66245篇 |
1985年 | 63062篇 |
1984年 | 46882篇 |
1983年 | 39914篇 |
1982年 | 23152篇 |
1979年 | 41950篇 |
1978年 | 29440篇 |
1977年 | 24657篇 |
1976年 | 23422篇 |
1975年 | 24416篇 |
1974年 | 29713篇 |
1973年 | 28827篇 |
1972年 | 26708篇 |
1971年 | 24777篇 |
1970年 | 23044篇 |
1969年 | 21341篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
991.
J L Dubois-Randé D Loisance A M Duval-Moulin P Deleuze D Lellouche O Tavolaro L Hittinger C Benvenuti P Merlet D Brun 《Archives des maladies du coeur et des vaisseaux》1989,82(8):1433-1438
Enoximone is a positive inotropic agent belonging to the group of phosphodiesterase F-III inhibitors. The drug was tested in 34 patients uncontrolled by sympathomimetic drugs and referred to our department for urgent heart transplantation or circulatory assistance. After insertion of a Swan-Ganzgatheter and a radial artery catheter for haemodynamic monitoring, enoximone was administered as a 15-minute intravenous bolus injection of 1 to 2.5 mg/kf every 8 hours, in addition to sympathomimetic agents. Clinical and haemodynamic improvement was observed after thirty minutes in 30 patients. The cardiac index rose from 1.82 to 2.67 l/min/m2 and the pulmonary wedge pressure fell from 30.8 to 18.9 mmHg. Systemic arterial resistance decreased from 2170 to 1520 dyn. s. cm-5, and pulmonary resistance from 5.5 to 4.6 Wood units (p less than 0.01 for all values). Four patients had no haemodynamic improvement and were put on circulatory assistance, using a Jarvik 7 total artificial heart in 3 of them and heterotopic circulatory assistance in one. After clinical investigation for contra-indication to heart transplantation, and as their improved haemodynamic status permitted, 12 of the 30 patients were considered suitable (group B) for heart transplantation. Transplantation was performed within a week of admission in 11 patients without any need for mechanical assistance. One of the group B patients who required implantation of a Jarvik 7 artificial heart died after 12 hours of assistance. Eighteen patients were considered unsuitable for transplantation (group A) and treated medically.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
992.
In 422 patients admitted from the emergency department (ED) for suspected acute myocardial infarction, the hypothesis that chest pain that persists on arrival in the ED or recurs during the initial ED evaluation is a useful predictor of acute myocardial infarction (AMI) and complications of coronary ischemia was tested. Compared with patients whose chest pain spontaneously ceased before arrival in the ED, patients whose chest pain persisted or recurred during the initial ED evaluation had a 2.3 times greater risk of interventions (P less than .001), a 1.7 times greater risk of complications (P = .045), a 3.8 times greater risk of life-threatening complications (P = .04), and a 2.4 times greater risk of AMI (P = .005). A third group of patients with suspected AMI never experienced chest pain. This group of patients who never experienced chest pain had a three times higher risk of death (P = .02) compared with patients whose chest pain persisted or recurred in the ED, and a 2.1 times greater risk of intervention (P = .01), a 5.2 times greater risk of life-threatening complication (P = .015), and a 7.9 times greater risk of death (P = .025) compared with patients whose chest pain resolved before arrival in the ED. It was concluded that patients with chest pain that resolves spontaneously before arrival to the ED have a better in-hospital prognosis than any other group. 相似文献
993.
994.
While the family's primacy in the patient's adaptation to chronic illness increasingly is being recognized by health professionals and social scientists, the reverse side of the coin, that is, the impact of chronicity on the family, has received little attention. A life-span development perspective is used to enrich the more traditional frameworks employed to study family development and also as a unifying framework from which to view the impact of illness on individual family members and the family as a unit. A review of selected literature reveals a profile of families most at risk for serious disruption in situations involving chronic illness. Propositions suggesting interventions directed at patients and families experiencing chronicity are derived. 相似文献
995.
Computed tomography is currently the modality of choice in imaging acutely traumatized patients. This is based upon CT's documented ability to detect surgically significant lesions. Furthermore, the use of MRI is limited by a lack of bone detail, the degradation of MR images in frequently uncooperative patients, and a limited supply of nonferromagnetic monitoring equipments. CT and MRI are largely equivalent in their ability to diagnose epidural hematoma, but CT is readily available and quick. MRI provides information in addition to that obtained by CT in many instances, such as subacute and chronic subdural hematomas, contusions, and intracerebral hematomas. 相似文献
996.
Adverse hemodynamic and clinical effects of encainide in severe chronic heart failure 总被引:1,自引:0,他引:1
STUDY OBJECTIVE: To evaluate the hemodynamic effects of the antiarrhythmic drug, encainide, in patients with severe chronic heart failure. DESIGN: Unblinded, before-after study. SETTING: Referral center for patients with heart failure. PATIENTS: Thirty patients with severe chronic heart failure and a left ventricular ejection fraction less than 40%. INTERVENTIONS: Invasive hemodynamic measurements were done (using a balloon-tipped thermodilution catheter) before and for 3 hours after a single oral dose of 50 mg of encainide. MEASUREMENTS AND MAIN RESULTS: Ninety to one hundred and twenty minutes after its administration, encainide produced a significant deterioration in cardiac performance, as reflected by a fall in cardiac index from 2.3 to 1.8 L/min.m2 body surface (mean change 0.5 +/- 0.1; P less than 0.001), a fall in stroke work index from 26 to 18 g.m/m2 (mean change 8 +/- 2; P less than 0.001), and an increase in left ventricular filling pressure from 19 to 22 mm Hg (mean change 3 +/- 2; P less than 0.05). These deleterious hemodynamic effects were accompanied by worsening symptoms of heart failure in 8 of the 30 patients. Serum levels of encainide and its metabolites, O-desmethylencainide and 3-methoxy-O-desmethylencainide, were within the therapeutic range in most patients. CONCLUSIONS: Encainide can cause adverse hemodynamic and clinical effects in patients with severe chronic heart failure. 相似文献
997.
A single trypanosome is sufficient to infect a tsetse fly 总被引:2,自引:0,他引:2
998.
999.
Retrosternal dislocations of the clavicle have been reported previously in adults throughout the orthopedic literature. However, in children few cases have been noted in either the pediatric, emergency, or orthopedic literature. The potential for great vessel injury as well as acute airway compromise makes the retrosternal disruption of the sternoclavicular joint a surgical emergency that must be diagnosed quickly. Diagnosis is enhanced by the cephalic tilt view and by computed tomography (CT scan), as planar x-ray and tomography do not always reveal this potentially life-threatening condition. Surgical consultation must be sought acutely; however, management may need to begin prior to definitive repair. Emergency management begins by suspecting the injury, and with immediate airway and circulatory support for the patient. 相似文献
1000.
A S Kalayjian 《Archives of Psychiatric Nursing》1989,3(3):166-172
This study explored coping difficulties experienced by wives of patients with a diagnosis of cancer. Concomitantly, the study explored the ways in which nurses intervened to help these wives. This study was designed as an exploratory study. The qualitative analysis made use of data derived from responses to open-ended questions presented to the respondents by the interview method. The study sample consisted of 40 wives who acknowledged experiencing coping difficulties in meeting the demands of everyday living as a result of their husband's diagnosis of cancer. Respondents were selected randomly from seven eligible representative settings located in the Mid-Atlantic region until the desired sample number was reached. Wives, who encountered the unexpected and uncontrollable situation of having a husband with diagnosed cancer, experienced a multitude of coping difficulties. In addition, wives underwent psychological disorganization, disequilibrium, and emotional imbalance. They attempted to cope with the resulting imbalance by using their habitual problem-solving behavior patterns and experienced difficulty when seeking situational supports. This, in turn, added to their stress. Wives also reported that their children had coping difficulties. Wives identified listening, talking, caring, availability of nurses to patients and patients' spouses, sensitivity, empathy, and honesty as essential helpful nursing behaviors. The study underscored the importance of viewing wives of cancer patients as unique systems in need of therapeutic support, and reaffirmed a view of nursing as the art of understanding the unique needs of individuals who are experiencing coping difficulties. This study also underscored the key role of psychiatric liaison nurses in providing supportive therapeutic interventions to the spouses of cancer patients as well as to the nursing staff. 相似文献