全文获取类型
收费全文 | 1534篇 |
免费 | 58篇 |
国内免费 | 171篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 85篇 |
妇产科学 | 6篇 |
基础医学 | 117篇 |
口腔科学 | 19篇 |
临床医学 | 212篇 |
内科学 | 304篇 |
皮肤病学 | 29篇 |
神经病学 | 22篇 |
特种医学 | 343篇 |
外科学 | 285篇 |
综合类 | 28篇 |
预防医学 | 47篇 |
眼科学 | 25篇 |
药学 | 156篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 67篇 |
出版年
2021年 | 4篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 17篇 |
2017年 | 17篇 |
2016年 | 15篇 |
2015年 | 16篇 |
2014年 | 28篇 |
2013年 | 50篇 |
2012年 | 40篇 |
2011年 | 47篇 |
2010年 | 53篇 |
2009年 | 50篇 |
2008年 | 39篇 |
2007年 | 147篇 |
2006年 | 56篇 |
2005年 | 67篇 |
2004年 | 42篇 |
2003年 | 46篇 |
2002年 | 54篇 |
2001年 | 37篇 |
2000年 | 35篇 |
1999年 | 34篇 |
1998年 | 85篇 |
1997年 | 82篇 |
1996年 | 73篇 |
1995年 | 63篇 |
1994年 | 42篇 |
1993年 | 55篇 |
1992年 | 13篇 |
1991年 | 21篇 |
1990年 | 20篇 |
1989年 | 56篇 |
1988年 | 37篇 |
1987年 | 40篇 |
1986年 | 37篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 28篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 16篇 |
1976年 | 28篇 |
1975年 | 14篇 |
1973年 | 8篇 |
1972年 | 5篇 |
1969年 | 6篇 |
排序方式: 共有1763条查询结果,搜索用时 15 毫秒
21.
Marrow regeneration after mechanical depletion 总被引:1,自引:0,他引:1
The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration. 相似文献
22.
A 15 year old boy with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome suffered recurrent episodes of severe intractable diarrhoea, steatorrhoea, and hypocalcaemia. The only treatment modality, which controlled the malabsorption syndrome, was immunosuppression with intravenous high dose methylprednisolone and oral methotrexate maintenance therapy. 相似文献
23.
Wang WS; Hsieh RK; Chiou TJ; Liu JH; Fan FS; Yen CC; Tung SL; Chen PM 《Japanese journal of clinical oncology》1998,28(9):551-554
A 54-year-old man was treated with weekly 24-h infusion of high-dose
5-fluorouracil (2600 mg/m2) and leucovorin (100 mg/m2) for metastatic colon
cancer. At first, he tolerated the treatment well and no significant
toxicity was identified. After a total of eight courses of treatment, a
stable disease was observed, but mild shortness of breath was found on
occasion. The patient had no previous history of cardiac disease and the
heart performance assessed by left ventricular ejection fraction before
treatment was normal. Unfortunately, acute pulmonary edema with lethal
cardiogenic shock occurred during the ninth course of treatment, in spite
of intensive medical treatment. The chest X-ray showed extreme
cardiomegaly. Repeated assessment of his heart function by echocardiogram
and ventricular ejection fraction revealed a very poor cardiac performance.
Toxic cardiogenic shock during weekly 24-h infusion of high-dose
5-fluorouracil and leucovorin is extremely rare. To the best of our
knowledge, no case has been reported in the English literature. We report a
case and the relevant literature about the incidence, clinical picture and
possible pathophysiology on 5-fluorouracil-related cardioxicity is
reviewed.
相似文献
24.
Eliminating blood transfusions: new aspects and perspectives 总被引:16,自引:0,他引:16
25.
26.
Sebastian D. Sahli Alexander Kaserer Julia Braun Maximilian Halbe Yuliya Dahlem Muriel A. Spahn Julian Rssler Bernard Krüger Francesco Maisano Donat R. Spahn Markus J. Wilhelm 《Journal of thoracic disease》2022,14(6):1960
BackgroundExtracorporeal life support (ECLS) therapy is increasingly used for cardiac and respiratory support postcardiotomy, refractory cardiogenic shock and cardiopulmonary resuscitation. This study aims to describe in-hospital mortality of patients requiring ECLS, identify independent predictors associated with mortality and analyze changes of mortality over time.MethodsThis retrospective study includes all adult ECLS cases at the University Hospital Zurich, a designated ECLS center in Switzerland, in the period 2007 to 2019.ResultsECLS therapy was required in 679 patients (median age 60 years, 27.5% female). In-hospital mortality was 55.5%. Cubic spline interpolation did not detect evidence for a change in mortality over the whole period of 13 years. In-hospital mortality significantly varied between ECLS indications: 70.7% (152/215) for postcardiotomy, 67.9% (108/159) for cardiopulmonary resuscitation, 47.0% (110/234) for refractory cardiogenic shock, and 9.9% (7/71) for lung transplantation and expansive thoracic surgery (P<0.001). Logistic regression modelling showed excellent discrimination in the receiver operating characteristic (ROC) area under the curve (AUC) of 0.89 [95% confidence interval (CI): 0.87–0.92] and identified significant mortality predictors: age, simplified acute physiology score (SAPS) II, as well as new liver failure and each allogenic blood transfusion unit given per day. ECLS after cardiopulmonary resuscitation was associated with significantly higher mortality compared to ECLS for refractory cardiogenic shock.ConclusionsIn-hospital mortality of patients treated with ECLS therapy is high. Outcomes have not changed significantly in the observed period. We identified age, SAPS II, new liver failure and each allogenic blood transfusion unit given per day as independent mortality predictors. Knowledge of predictors strongly associated with in-hospital mortality may affect future decisions about ECLS indications and the respective management to use this elaborate therapy more effectively. 相似文献
27.
Marcel JH Aries Adnan Aslan Jan Willem J Elting Roy E Stewart Jan G Zijlstra Jacques De Keyser Patrick CAJ Vroomen 《Journal of clinical nursing》2012,21(13-14):1825-1830
Background. Routine lateral turning of patients has become an accepted standard of care to prevent complications of immobility. The haemodynamic and oxygenation effects for patients in both lateral positions (45°) are still a matter of debate. We aimed to study the effect of these positions on blood pressure, heart rate and oxygenation in a general intensive care population. Design. Observational study. Method. Twenty stable intensive care unit patients had intra‐arterial blood pressure recordings in the supine and lateral positions with the correction of hydrostatic height compared with a fixed reference point (phlebostatic level). A multilevel model was used to analyse the data. Results. Mean arterial pressure readings in the lateral positions were, on average, 5 mmHg higher than in the supine position (p < 0·001). There were no significant differences between mean arterial pressure recordings in the left and right lateral position (p = 1·0). No important differences in oxygenation and heart rate were observed. After correction for covariates, the effects persisted. Conclusion. Our study demonstrated an increase, albeit small, in blood pressure in the lateral positions. No major differences between the left and right lateral position were found. No important differences in oxygenation and heart rate were observed. Relevance to clinical practice. Turning haemodynamically stable patients in the intensive care unit has no important effects on blood pressure measurements when continuous hydrostatic height correction is applied. 相似文献
28.
Eberth F. Gantz S. Grifka J. Liebers F. Schiltenwolf M. Spahn G. Vaitl T. 《Trauma und Berufskrankheit》2012,14(4):441-443
This contribution gives a brief overview of the current state of scientific knowledge on the genetic causes of knee osteoarthrosis. Correlations between genetic and molecular biological characteristics and the increased risk of premature knee joint degeneration are revealed, based on the results of numerous international studies. Their relevance to the assessment according to the Social Security Code VII is discussed. 相似文献
29.
SB Cho JH Kim S Cho JM Park YK Park SH Oh 《Journal of the European Academy of Dermatology and Venereology》2011,25(1):64-67
Background The clinical characteristics of vitiligo in children and adolescents with an emphasis on thyroid dysfunction have only been reported in a few studies. Objective The purpose of this study was to examine the characteristics of children and adolescents with vitiligo and compare the incidence of thyroid dysfunction between them and controls without vitiligo at the same age. Methods A retrospective analysis of 324 Korean children and adolescents with vitiligo was performed. The results of thyroid function screening tests in them (n = 254) were compared with controls (n = 122). Results Of the total 324 children and adolescents with vitiligo, vitiligo vulgaris was the most common type (42.3%) and the most commonly involved site was the face (54.6%). A total of 15 of 254 (5.9%) patients screened for thyroid function were diagnosed with thyroid disease (four had Hashimoto’s thyroiditis; two, Graves’ disease; seven, subclinical hypothyroidism; and two, subclinical hyperthyroidism). None of the 50 patients with segmental vitiligo showed any thyroid dysfunction (P = 0.047). There was no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group, in which seven of 122 (5.7%) showed thyroid dysfunction. Conclusion In this study, we demonstrated the characteristics of children and adolescents with vitiligo and also observed no significant difference in the incidence of thyroid disease between children and adolescents with vitiligo and the control group. 相似文献
30.
Familial protein S deficiency with a variant protein S molecule in plasma and platelets 总被引:3,自引:0,他引:3
A protein S deficient family presenting a variant protein S molecule in plasma and platelets is described. The propositus, age 20, and two brothers suffered from venous thrombotic disease. The propositus, the only family member studied while taking oral anticoagulants, had a protein S antigen (ag) level of 17% and undetectable activity. As demonstrated by immunoblotting both the propositus and one clinically affected brother (42% ag, 7% activity) presented variant protein S molecules of 65,000 molecular weight (mol wt) while the other clinically affected brother (64% ag, 11% activity) had only protein S with normal electrophoretic mobility of 70,000 mol wt. The mother had normal protein S levels (93% ag, 100% activity) but had both normal and variant protein S molecules and based on her functional protein S data a normal anticoagulant activity of the variant molecule is suggested. One asymptomatic but protein S deficient sister (68% ag, 9% activity) as well as the asymptomatic protein S deficient father (59% ag, 10% activity) had only protein S molecules of 70,000 mol wt. The variant protein S bound to C4b-binding protein in plasma, and differed from normal protein S in carbohydrate content. Platelets of each family member contained the same immunoblotting pattern of normal and variant protein S forms as found in plasma, consistent with the hypothesis that protein S gene expression involves codominant expression of two alleles that is similar in cells that control the synthesis of both platelet and plasma forms of protein S. 相似文献