全文获取类型
收费全文 | 15097篇 |
免费 | 1228篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 163篇 |
儿科学 | 528篇 |
妇产科学 | 426篇 |
基础医学 | 1755篇 |
口腔科学 | 228篇 |
临床医学 | 1790篇 |
内科学 | 3139篇 |
皮肤病学 | 256篇 |
神经病学 | 1586篇 |
特种医学 | 477篇 |
外国民族医学 | 1篇 |
外科学 | 1931篇 |
综合类 | 319篇 |
一般理论 | 6篇 |
预防医学 | 1620篇 |
眼科学 | 281篇 |
药学 | 853篇 |
中国医学 | 5篇 |
肿瘤学 | 983篇 |
出版年
2023年 | 88篇 |
2022年 | 175篇 |
2021年 | 344篇 |
2020年 | 217篇 |
2019年 | 253篇 |
2018年 | 342篇 |
2017年 | 263篇 |
2016年 | 269篇 |
2015年 | 330篇 |
2014年 | 430篇 |
2013年 | 609篇 |
2012年 | 875篇 |
2011年 | 926篇 |
2010年 | 512篇 |
2009年 | 458篇 |
2008年 | 771篇 |
2007年 | 760篇 |
2006年 | 691篇 |
2005年 | 712篇 |
2004年 | 686篇 |
2003年 | 666篇 |
2002年 | 594篇 |
2001年 | 300篇 |
2000年 | 325篇 |
1999年 | 270篇 |
1998年 | 154篇 |
1997年 | 132篇 |
1996年 | 125篇 |
1995年 | 100篇 |
1994年 | 96篇 |
1993年 | 100篇 |
1992年 | 235篇 |
1991年 | 251篇 |
1990年 | 227篇 |
1989年 | 208篇 |
1988年 | 248篇 |
1987年 | 221篇 |
1986年 | 233篇 |
1985年 | 198篇 |
1984年 | 192篇 |
1983年 | 172篇 |
1982年 | 111篇 |
1981年 | 101篇 |
1979年 | 150篇 |
1978年 | 92篇 |
1977年 | 95篇 |
1976年 | 89篇 |
1974年 | 102篇 |
1973年 | 95篇 |
1972年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Childhood tuberculosis in Leeds, 1982-90: social and ethnic factors and the role of the contact clinic in diagnosis. 总被引:1,自引:1,他引:0 下载免费PDF全文
A retrospective analysis of childhood tuberculosis in Leeds over a nine year period (1982-90) was performed which showed that the contact clinic is important for the early detection and treatment of disease in children. Two thirds of the cases of tuberculosis in children under 15 years were diagnosed and treated at the clinic. The incidence of tuberculosis was greater in Asian than in white children and, independent of race, was greater in the most deprived area of the city. 相似文献
42.
J C Horrow J Hlavacek M D Strong W Collier I Brodsky S M Goldman I P Goel 《The Journal of thoracic and cardiovascular surgery》1990,99(1):70-74
Thirty-eight patients undergoing a cardiac operation randomly received either tranexamic acid, a potent inhibitor of plasminogen, or placebo in an effort to determine whether prophylactic antifibrinolytic therapy reduces chest tube drainage. Twelve-hour blood loss was 750 +/- 314 (standard deviation) ml in the placebo group and 496 +/- 228 ml in the drug group (p = 0.0057). Fibrin split products were present more frequently in patients in the placebo group (17 of 20 compared with four of 18 in the drug group; p = 0.0002). Tranexamic acid markedly decreased plasminogen availability (112 +/- 104 units in the placebo group versus 36 +/- 18 units in the drug group, p = 0.0058). Plasma fibrinogen concentrations were similar in the placebo and drug groups. Patients in the placebo group received more fresh-frozen plasma and more mediastinal shed blood than those in the drug group. No coagulation-related complication occurred in the group receiving tranexamic acid. We conclude that prophylactic tranexamic acid can be administered safely to inhibit fibrinolysis during cardiac operations, decrease postoperative bleeding, and possibly decrease the frequency of blood product transfusion. 相似文献
43.
Advertisers have adopted the use of highly abstract visual metaphors and symbols in addressing physicians about antidepressant drugs. Campaigns built around an abstract visual aesthetics are designed to generate cognitive connections between named drug entities and the meaning of abstract visual images: these connections are called 'carry-over symbols'. In this study we critically dismantle and analyze the encoding practices used in two recent ad campaigns for antidepressants. In addition to asking what the ads mean, we ask how they mean it. This analysis is joined to a comparison of the information provided by these ads with the pharmacological and therapeutic properties of the drugs themselves. Our analysis suggests this style of drug advertising produces, as a social side-effect, a reified and medicalized account of psychiatric illness (depression). It also poses an obstacle to scientific discourse and understanding; privileges certain types of social knowledge concerning mental illness, psychiatric patients, and drug taking; and discourages professional d debate regarding therapeutic approaches to treating illness. These ads reflect a positivistic conceptualization of mental illness and doctoring as mind mechanics. 相似文献
44.
45.
Rajiv Tandon Robert Goldman John R. DeQuardo Mona Goldman Melinda Perez Michael Jibson 《Journal of psychiatric research》1993,27(4):341-347
Although negative symptoms were traditionally considered to be unresponsive to neuroleptic medication, recent studies have demonstrated that negative symptoms do improve during neuroleptic treatment and that such improvement tends to occur concurrently with improvement in positive symptoms. Clozapine is an atypical neuroleptic that is effective in a significant proportion of otherwise neuroleptic-nonresponsive schizophrenic patients; in contrast to conventional neuroleptics, clozapine is also purported to possess unique efficacy in the amelioration of negative symptoms. How clozapine-associated reduction in negative symptoms relates to change in positive symptoms is not clear. To study the relationship between change in positive and negative symptoms during clozapine treatment, we monitored symptomatology in 40 DSM-III-R schizophrenic patients before and about 8 weeks after a trial of clozapine. Both positive and negative symptoms improved significantly. There was a significant correlation (r = .63,p <.01) between change in positive symptoms and change in negative symptoms; as with conventional neuroleptics, negative symptoms improved concomitantly with positive symptoms during clozapine treatment. Clozapine's apparent greater efficacy on negative symptoms may be related to its greater efficacy on positive symptoms in otherwise neuroleptic-refractory patients and its lesser propensity to cause extrapyramidal side-effects. 相似文献
46.
47.
A new computed tomographic and sonographic appearance of renal metastatic melanoma is described. Bilateral cystic masses with thick walls, many with mural nodules, were noted. Sonography also demonstrated complex echopenic masses with irregularly thickened walls and mural nodules. 相似文献
48.
This study describes our experience using a percutaneously placed small-bore catheter for drainage of malignant pleural effusions and subsequent instillation of a sclerosing agent to obliterate the pleural space. We treated 15 consecutive patients with known metastatic cancer and a symptomatic pleural effusion. Twelve patients survived for more than four weeks after the procedure; 11 of these 12 patients had a successful objective clinical response. The procedure was well tolerated, with little or no discomfort during catheter placement and the maintenance period. No serious complications were encountered. We conclude that the use of a small-bore percutaneously placed "pneumothorax" catheter in the management of malignant pleural effusions is an effective and more comfortable alternative to large-bore closed-tube thoracostomy. 相似文献
49.
In 1987 Medicare benefits for the mentally ill were expanded for the first time in 22 years. A major change was the removal of limits and copayments for the "medical management of psychopharmacologic agents." Payment for medical management recognizes the trend toward the remedicalization of psychiatry; however, medical management can be defined either broadly or narrowly. The authors suggest pricing strategies for both medical management of mental disorders and psychotherapy. Enlightened design of psychiatric benefits will cover all forms of treatment according to appropriate rules. Access to treatment for mental illness is at stake as these rules develop. 相似文献
50.
The mere exposure effect was examined in patients with mild to moderate Alzheimer's disease (AD). Twenty patients and 20 elderly controls judged the physical characteristics of faces. Implicit memory was tested later by presenting pairs of faces (old and new) and asking participants which faces they liked better. Patients and controls exhibited above chance preference for previously exposed faces. Experiment 2 evaluated whether the preserved implicit memory of patients was mediated by explicit memory. Patients and controls again judged faces but then later chose which faces they had seen before. Patients exhibited impaired recognition memory compared to controls. These findings suggest that a mere exposure effect for unfamiliar faces is present in mild to moderate AD. The results are discussed in terms of perceptual and conceptual priming and relatively spared occipital lobe functioning in early AD. 相似文献