全文获取类型
收费全文 | 7863篇 |
免费 | 2656篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 255篇 |
儿科学 | 241篇 |
妇产科学 | 222篇 |
基础医学 | 240篇 |
口腔科学 | 73篇 |
临床医学 | 1235篇 |
内科学 | 2126篇 |
皮肤病学 | 468篇 |
神经病学 | 707篇 |
特种医学 | 225篇 |
外科学 | 2612篇 |
综合类 | 38篇 |
预防医学 | 612篇 |
眼科学 | 608篇 |
药学 | 173篇 |
中国医学 | 5篇 |
肿瘤学 | 717篇 |
出版年
2024年 | 89篇 |
2023年 | 708篇 |
2022年 | 103篇 |
2021年 | 309篇 |
2020年 | 411篇 |
2019年 | 194篇 |
2018年 | 717篇 |
2017年 | 761篇 |
2016年 | 668篇 |
2015年 | 609篇 |
2014年 | 824篇 |
2013年 | 742篇 |
2012年 | 385篇 |
2011年 | 376篇 |
2010年 | 534篇 |
2009年 | 708篇 |
2008年 | 321篇 |
2007年 | 187篇 |
2006年 | 270篇 |
2005年 | 173篇 |
2004年 | 130篇 |
2003年 | 105篇 |
2002年 | 121篇 |
2001年 | 140篇 |
2000年 | 93篇 |
1999年 | 98篇 |
1998年 | 106篇 |
1997年 | 110篇 |
1996年 | 70篇 |
1995年 | 71篇 |
1994年 | 50篇 |
1993年 | 37篇 |
1992年 | 48篇 |
1991年 | 46篇 |
1990年 | 34篇 |
1989年 | 30篇 |
1988年 | 32篇 |
1987年 | 14篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1973年 | 5篇 |
1971年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
Betina N?rager Mirza Husic Jacob E M?ller Kenneth Egstrup 《Journal of the American Society of Echocardiography》2004,17(7):732-738
BACKGROUND: Wall-motion analysis during low-dose dobutamine echocardiography (LDDE) is a semiquantitative measure of left ventricular contractile reserve after myocardial infarction (MI). The Doppler echocardiographic myocardial performance index (MPI) is a quantitative measure of combined left ventricular systolic and diastolic function. We sought to characterize the changes in MPI during LDDE in control subjects and patients with MI, and to describe the relation of these changes to changes in regional systolic function. METHODS: MPI was obtained at rest and during LDDE (10 microg/kg/min) in 25 healthy volunteers (group 1) and 50 patients with a recent MI. Patients were divided into two subsets; those with (n = 23; group 2A) and those without (n = 27; group 2B) a contractile reserve defined as an improvement of wall motion in more than two contiguous infarct-zone segments during LDDE. DeltaMPI was defined as the change from rest to LDDE. RESULTS: MPI decreased significantly during LDDE in groups 1 and 2A, whereas MPI increased in group 2B (DeltaMPI = 0.12 +/- 0.04 and 0.10 +/- 0.08 vs -0.03 +/- 0.08, P <.0001). On multivariate analysis, Deltawall-motion score index predicted DeltaMPI (beta = 0.65, P <.0001) independently of age, sex, and the dobutamine-induced change in heart rate and systolic blood pressure. CONCLUSIONS: Data suggest that the change in MPI during LDDE may provide a simple and quantitative measure of overall left ventricular functional reserve in patients with a recent MI. 相似文献
24.
Images in emergency medicine 总被引:1,自引:0,他引:1
25.
Paul Devakar Yesudian MD Srivilliputtur G.S. Krishnan MBBS Muriugaiya Jayaraman MD Vanakampadi R. Janaki MD Patrick Yesudian FRCP 《International journal of dermatology》1997,36(3):194-196
Background Pemphigus is a group of vesiculobullous disorders in which the blisters usually heal with hyper- or hypopigmentation. The appearance of acanthomata at sites of previous blisters has been noted in some cases. Methods All cases of pemphigus admitted to the Madras Medical College hospitals during a 2-year period from March 1993 to March 1995 were taken into the study and screened for the presence of acanthomata. Results Fifty-two cases of pemphigus were identified, 47 of pemphigus vulgaris and five of pemphigus foliaceus; and of these 13 developed acanthomata when the blisters healed. Ten of these cases were of pemphigus vulgaris and three were of pemphigus foliaceus; biopsy of these lesions showed hyperkeratosis, acanthosis, papillomatosis, and intraepidermal clefting. Immunofluorescence carried out in two of these acanthomata also showed intercellular fluorescence. Conclusions The occurrence of acanthomata in healed lesions of pemphigus is not uncommon; because histopathologic and immunofluorescence evidence of disease activity is present, cases of this sort require careful follow-up. 相似文献
26.
27.
B.H. Lim MRCOG FRNZCOG C.L. Barry MBBS G.H. Brown MRCOG 《The Australian & New Zealand journal of obstetrics & gynaecology》1991,31(1):20-21
We describe a case of preeclampsia with the HELLP (Haemolysis, Elevated Liver enzymes, Low Platelets) syndrome and highlight the delayed diagnosis due to its nonspecific presentation. This syndrome is associated with significant maternal and perinatal mortality and morbidity and we discuss the importance of early recognition of the condition, aggressive management and a multidisciplinary approach. 相似文献
28.
OBJECTIVE--To identify prognostic factors in a consecutive series of patients with bleeding oesophageal varices and develop an optimum regimen of treatment. DESIGN--Retrospective review. SETTING--I Department of Surgery, University Hospital, Vienna, Austria. PATIENTS--301 consecutive patients with bleeding oesophageal varices. OUTCOME MEASURES--Median survival and survival at one year after sclerotherapy alone (n = 213), or sclerotherapy with portosystemic shunt (n = 54), Hassab's devascularisation (n = 29), or liver transplantation (n = 5). RESULTS--Prognosis was dependent on the severity of liver damage at the start of treatment. Median survival for Child's class A was 47 months, for Child's class B 54 months, and for Child's class C 2 months. The overall one year survival for patients in Child's class C was 33%, for sclerotherapy alone 28%, and for sclerotherapy and portosystemic shunt 42%, Hassab's devascularisation 50%, and liver transplantation 80%. CONCLUSION--Despite the small number of patients who underwent liver transplantation and their poor initial prognosis (Child's class C, n = 4; class B, n = 1) our results suggest that liver transplantation should be considered for the treatment of patients with end stage cirrhosis and bleeding varices. 相似文献
29.
30.
D. P. Southall M.D. M.R.C.P. V. A. Stebbens B.Sc. Research Assistant R. Mirza B.Sc. Research Assistant M. H. Lang B.Sc. Research Assistant C. B. Croft M.B. Ch.B. F.R.C.S E. A. Shinebourne M.D. F.R.C.P 《Developmental medicine and child neurology》1987,29(6):734-742
Six of 12 children with Down syndrome (DS) tested by means of long-term tape-recordings of oxygen saturation, breathing movements and expired CO2 were found to have previously undetected and severe upper airway obstruction during sleep. In five cases the obstruction occurred in the pharynx and in the sixth it was due to bilateral choanal stenosis. When compared with age-matched controls, overnight tape-recordings showed episodes of abnormal arterial hypoxaemia and an abnormally elevated end-tidal CO2. Episodes of obstruction were most marked during sleep associated with a non-regular breathing pattern. Abnormal episodes of hypoxaemia were associated with continued breathing movements. Sometimes there was no airflow (complete obstruction); at other times airflow continued normally or was reduced in amplitude (partial obstruction). During episodes of partial or complete airway obstruction the inspiratory waveform showed a characteristic shape. These results show sleep-related upper airway obstruction to be an often undetected complication of DS and all necessary measures should be taken to overcome the obstruction when it reaches the stage of producing abnormal hypoxaemia. Choanal dilatation and tracheostomy were successful in treating two of the children. Tonsillectomy and adenoidectomy were successful for one child, but only of marginal benefit for two others. 相似文献