全文获取类型
收费全文 | 31355篇 |
免费 | 2575篇 |
国内免费 | 210篇 |
专业分类
耳鼻咽喉 | 318篇 |
儿科学 | 1094篇 |
妇产科学 | 705篇 |
基础医学 | 3639篇 |
口腔科学 | 643篇 |
临床医学 | 2955篇 |
内科学 | 6650篇 |
皮肤病学 | 549篇 |
神经病学 | 2407篇 |
特种医学 | 1118篇 |
外科学 | 4690篇 |
综合类 | 841篇 |
一般理论 | 14篇 |
预防医学 | 2068篇 |
眼科学 | 1311篇 |
药学 | 2347篇 |
1篇 | |
中国医学 | 131篇 |
肿瘤学 | 2659篇 |
出版年
2023年 | 218篇 |
2022年 | 344篇 |
2021年 | 739篇 |
2020年 | 472篇 |
2019年 | 696篇 |
2018年 | 801篇 |
2017年 | 568篇 |
2016年 | 657篇 |
2015年 | 752篇 |
2014年 | 1032篇 |
2013年 | 1216篇 |
2012年 | 1989篇 |
2011年 | 2047篇 |
2010年 | 1185篇 |
2009年 | 1037篇 |
2008年 | 1794篇 |
2007年 | 1763篇 |
2006年 | 1618篇 |
2005年 | 1544篇 |
2004年 | 1552篇 |
2003年 | 1372篇 |
2002年 | 1228篇 |
2001年 | 1138篇 |
2000年 | 1033篇 |
1999年 | 886篇 |
1998年 | 333篇 |
1997年 | 257篇 |
1996年 | 224篇 |
1995年 | 230篇 |
1994年 | 212篇 |
1993年 | 180篇 |
1992年 | 514篇 |
1991年 | 481篇 |
1990年 | 442篇 |
1989年 | 413篇 |
1988年 | 373篇 |
1987年 | 344篇 |
1986年 | 340篇 |
1985年 | 337篇 |
1984年 | 230篇 |
1983年 | 208篇 |
1982年 | 148篇 |
1981年 | 112篇 |
1980年 | 119篇 |
1979年 | 162篇 |
1978年 | 96篇 |
1977年 | 104篇 |
1976年 | 74篇 |
1974年 | 85篇 |
1973年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Despite improvements in surgical techniques, some complex bile duct strictures continue to present difficult management problems. Strictures recurring after previous biliary-enteric bypass, those associated with established biliary cirrhosis or coexistent malignancy, and those that follow hepatic resection may pose almost insuperable technical and physiological problems. Percutaneous transhepatic balloon dilatation will not solve all problems, but can help in some instances. Six patients are presented in whom this technique has been used in attempts to overcome particular problems. The strengths and weaknesses of the method are discussed. 相似文献
72.
73.
74.
75.
A double-blinded study was conducted to compare the effects of mupirocin and tetracycline ointments in the treatment of skin infections. 111 patients were available for clinical assessment, of which 53 were treated with mupirocin and 58 treated with tetracycline. Clinically, both groups were improved, and there was no significant difference. Bacteriological assessment however revealed a better response to mupirocin. Staphylococcus aureus and Streptococcus pyogenes were the most common organisms isolated. 99% of Staphylococci were sensitive to mupirocin compared with 61% to tetracycline and 29% to penicillin G. 57% of Group A beta haemolytic Streptococci were resistant to tetracycline compared to 14% to mupirocin. Gram-negative organisms were mostly resistant to both preparations. No side effects were observed in both treatment groups. This study suggests that mupirocin is a safe and effective topical preparation for treating most of our common skin infections. 相似文献
76.
X. Liu R. L. Phillips S. M. Resnick V. L. Villemagne D. F. Wong J. M. Stapleton E. D. London 《Acta neurologica Scandinavica》1995,92(1):83-90
Previous studies of cerebral structure in substance abusers yielded controversial results, largely due to issues of subject selection and/or limitations of experimental techniques. The purpose of the present study was to assess whether the ventricle-to-brain ratio (VBR), determined volumetrically by magnetic resonance imaging (MRI), differed in polysubstance abusers (n = 10), as compared with age-matched controls (n = 10). Subjects were male volunteers 21–39 years of age. The values of VBR in the polydrug abuse group were not larger than those in control group, nor was there any tendency toward relative ventriculomegaly in the substance abusers. Therefore, the present findings provide no evidence that polysubstance abuse produces abnormalities of gross brain structure in relatively young and physically healthy men. 相似文献
77.
78.
Wing-Yen Wong Donald Williams Marilyn L. Slovak Bishan Charak Amitabha Mazumder David Snyder Darleen R. Powars Russell K. Brynes 《American journal of hematology》1993,43(2):133-138
Congenital agranulocytosis terminating in acute myelogenous leukemia has been previously reported in only two cases of adolescent males. We describe the clinical and laboratory features of a 13-year-old male with congenital agranulocytosis, treated with G-CSF with initial good neutrophil response, who subsequently developed acute myeloid leukemia. This rare complication may define a preleukemic subset of patients for whom G-CSF therapy is ineffective. The diagnostic challenges of this case are presented. 相似文献
79.
M Ahumada Ayala D Lozano O Lozano J A Rull M Cárdenas V Valles B Wong 《Archivos del Instituto de Cardiología de México》1988,58(1):15-26
Several lines of evidence have clearly established the role of lipoproteins as risk factors for the development of atherosclerosis. Epidemiologic studies from different countries have found that about one third of myocardial infarction survivors under 60 years of age are hyperlipidemic. The acute stress reaction occurring in the first hours following an acute myocardial infarction causes distinct changes in the patient's metabolic profile, these changes include a significant reduction of total cholesterol and cholesterol associated with low density lipoproteins and a usually mild elevation of blood glucose. With the purpose of establishing the prevalence and severity of lipoprotein disorders found in myocardial infarction survivors living in Mexico city we conducted a prospective study of 106 consecutive admissions to the coronary care unit at the National Institute of Cardiology with the fully proven diagnosis of acute myocardial infarction, we included only patients younger than 60 years of age that could be sampled within the first 72 hours of the appearance of typical symptoms, at this time the coronary risk factor profile was assessed and blood samples were drawn (acute sample). After three months of the diagnosis we sampled 81 of the original 106 patients (chronic sample). The comparison of these 81 patients showed remarkable differences in the lipid values obtained on each sample. The mean value for total cholesterol in the acute sample was 225 mg/dl whereas the corresponding value for the chronic sample was 240.5 mg/dl (p less than 0.005). This difference was also highly significant for the low density fraction. On the basis of the chronic sample analysis we estimated a prevalence of hyperlipoproteinemia of 35.8%. (II: 18.5%, III: 2.5%, IV: 14.8%), an additional subgroup of 10 patients (12.3%) had the hypo-HDL phenotype raising the number of subjects at risk for atherosclerosis to as high as 48.1% considering only the lipoproteins. The prevalence figures for the rest of the risk factors were as follows: 70.3% for tobacco smoking, 35.8% for Systemic Arterial Hypertension, 33.4% for Obesity and 30.8% for Diabetes Mellitus. Among the group of 81 patients, 17 were known diabetics, eight additional cases of Diabetes Mellitus were diagnosed at the chronic phase (two with fasting hyperglycemia and six with diagnostic oral glucose tolerance tests). The "acute plase" glycemia for these eight subjects was significantly higher (mean: 98.4 mg/dl) than the corresponding value for the non diabetic patients (mean: 83.4 mg/dl p less than 0.002), the seventeen known diabetics had a mean glycemia of 150.6 mg/dl in the acute sample.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
80.