全文获取类型
收费全文 | 4141篇 |
免费 | 588篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 147篇 |
妇产科学 | 84篇 |
基础医学 | 520篇 |
口腔科学 | 77篇 |
临床医学 | 363篇 |
内科学 | 1092篇 |
皮肤病学 | 46篇 |
神经病学 | 420篇 |
特种医学 | 227篇 |
外科学 | 587篇 |
综合类 | 139篇 |
预防医学 | 481篇 |
眼科学 | 101篇 |
药学 | 259篇 |
肿瘤学 | 171篇 |
出版年
2021年 | 45篇 |
2019年 | 35篇 |
2018年 | 35篇 |
2015年 | 50篇 |
2014年 | 55篇 |
2013年 | 91篇 |
2012年 | 124篇 |
2011年 | 135篇 |
2010年 | 91篇 |
2009年 | 90篇 |
2008年 | 109篇 |
2007年 | 128篇 |
2006年 | 146篇 |
2005年 | 159篇 |
2004年 | 149篇 |
2003年 | 106篇 |
2002年 | 119篇 |
2001年 | 107篇 |
2000年 | 100篇 |
1999年 | 103篇 |
1998年 | 63篇 |
1997年 | 65篇 |
1996年 | 76篇 |
1995年 | 54篇 |
1994年 | 54篇 |
1993年 | 59篇 |
1992年 | 110篇 |
1991年 | 99篇 |
1990年 | 120篇 |
1989年 | 146篇 |
1988年 | 126篇 |
1987年 | 136篇 |
1986年 | 138篇 |
1985年 | 130篇 |
1984年 | 123篇 |
1983年 | 137篇 |
1982年 | 84篇 |
1981年 | 83篇 |
1980年 | 83篇 |
1979年 | 111篇 |
1978年 | 85篇 |
1977年 | 77篇 |
1976年 | 51篇 |
1975年 | 55篇 |
1974年 | 49篇 |
1973年 | 41篇 |
1972年 | 46篇 |
1971年 | 47篇 |
1970年 | 48篇 |
1969年 | 36篇 |
排序方式: 共有4758条查询结果,搜索用时 15 毫秒
101.
Evidence suggests a role for central dopaminergic activity in determining an individual's level of hypnotizability. The authors measured the correlation between blink rate, which has been shown to correlate with central dopaminergic activity, and hypnotizability. Forty-eight healthy participants were evaluated for hypnotizability by the Harvard Group Scales of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scale: Form C. Blink rate was assessed under conditions of conversation, staring at a cross, listening to music, and resting. Contrary to their hypothesis, the authors found a negative correlation between hypnotizability and blink rate, accounted for primarily by the higher blink rates at rest in medium as compared to high hypnotizables. The results do not provide evidence for a role of dopamine in determining hypnotizability. 相似文献
102.
M. Kay Libbus Linda F. C. Bullock Teak Nelson Linda Robrecht Mary Ann Curry Tina Bloom 《Issues in mental health nursing》2013,34(9):927-938
This study used Landenburger's theory, a process of leaving and recovering from an abusive relationship, as a framework to interview 35 pregnant women identified as being at high risk for abuse. Results are reported on 18 women who disclosed active abuse during the study. Landenburger's model was not a good fit. Our participants became trapped and endured violent relationships if they perceived this was the best situation for their unborn child. Additionally the chaos, instability, and lack of resources experienced by these women likely contributed to their inability to complete the four phases described by Landenburger's model for non-pregnant women 相似文献
103.
Intra-arterial tissue adhesive for medical splenectomy in humans 总被引:2,自引:0,他引:2
104.
Identification of the molecular defect in the erythrocyte membrane skeleton of some kindreds with hereditary spherocytosis 总被引:12,自引:0,他引:12
We have localized the molecular alteration in the membrane skeleton of two of four kindreds with hereditary spherocytosis (HS) to an alteration in the spectrin-protein-4.1 interaction due to a defective spectrin molecule. The defective spectrin-protein-4.1 interaction in these kindreds (referred to as type I HS) leads to a weakened spectrin- protein-4.1-actin ternary complex, which in turn may lead to the friable membrane skeleton and suggested membrane instability related to this disorder. Type I HS spectrin binds approximately 63% as much protein-4.1 as normal spectrin (with equal affinity). This defect does not correlate with splenic function or erythrocyte age in the circulation. However, the approximately 37% reduction in binding of protein-4.1 to HS spectrin approaches the theoretical value of 50% expected in this autosomal dominant disorder. All other type I membrane skeletal interactions (spectrin-syndein, spectrin heterodimer- heterodimer, syndein-band-3) were found to be normal. It would appear therefore that the defective HS spectrin-protein-4.1 interaction in type I hereditary spherocytosis may be the primary molecular defect rather than a secondary phenomena. 相似文献
105.
David M. Gilligan Antonios Marsonis Jayshree Joshi Stephen R. Bloom Celia M. Oakley Petros Nihoyannopoulos Mohammad A. Ghatei 《Clinical cardiology》1996,19(2):129-135
Some patients with hypertrophic cardiomyopathy experience postprandial exacerbation of symptoms. The aim of this study was to determine whether the hemodynamic and/or hormonal responses to a meal differ between patients with and without postprandial symptoms. Ten hypertrophic cardiomyopathy patients with postprandial symptoms, 10 patients without postprandial symptoms, and 10 normal subjects ate a 740 Kcal meal, following which heart rate, blood pressure, and echocardiographic and gastrointestinal hormone changes were compared among the three groups. Heart rate increased (p<0.001) and diastolic blood pressure fell (p < 0.001) to a similar degree in the three groups. Left ventricular outflow tract velocity increased (p< 0.01) and some patients had substantial increases in outflow tract pressure gradient; however, this was independent of the presence or absence of postprandial symptoms. The atrial contribution to filling increased in normal subjects and in both groups of hypertrophic cardiomyopathy patients. There was no significant difference in the gastrointestinal hormone changes in the three groups. In summary, there is no evidence for a distinctive hemodynamic or hormonal response to food in hypertrophic cardiomyopathy patients with postprandial symptoms. These symptoms more likely reflect differences in underlying cardiac disease characteristics and severity. 相似文献
106.
Carlson D Hernandez J Bloom BJ Coburn J Aversa JM Steere AC 《Arthritis and rheumatism》1999,42(12):2705-2709
OBJECTIVE: To determine whether Borrelia burgdorferi DNA may be detected in synovial tissue from patients with Lyme arthritis who have persistent synovial inflammation after antibiotic treatment. METHODS: Synovial specimens obtained at synovectomy from 26 patients with antibiotic treatment-resistant Lyme arthritis and from 10 control subjects were tested for B burgdorferi DNA using 3 primer-probe sets that target genes encoding outer surface proteins A or B or a flagellar protein (P41) of the spirochete. RESULTS: The 26 patients with Lyme arthritis, who had received antibiotic therapy for a mean total duration of 8 weeks prior to synovectomy, and the 10 control subjects each had negative polymerase chain reaction (PCR) results in synovial samples. When the samples were spiked with approximately 1-10 B burgdorferi, all but 1 had positive PCR results, suggesting that spirochetal DNA could have been detected in most of the unspiked samples if it had been present. CONCLUSION: These results indicate that synovial inflammation may persist in some patients with Lyme arthritis after the apparent eradication of the spirochete from the joint with antibiotic therapy. 相似文献
107.
Druce MR Wren AM Park AJ Milton JE Patterson M Frost G Ghatei MA Small C Bloom SR 《International journal of obesity (2005)》2005,29(9):1130-1136
OBJECTIVE: To investigate whether effects on food intake are seen in obese subjects receiving exogenous administration of ghrelin. DESIGN: Randomised, double-blind, placebo-controlled study of intravenous ghrelin at doses 1 pmol/kg/min and 5 pmol/kg/min. SUBJECTS: In all, 12 healthy lean subjects (mean body mass index (BMI) 20.5+/-0.17 kg/m(2)) and 12 healthy overweight and obese subjects (mean BMI 31.9+/-1.02 kg/m(2)). MEASUREMENTS: Food intake, appetite and palatability of food, ghrelin and other obesity-related hormones, growth hormone. RESULTS: Low-dose infusion of ghrelin increased ad libitum energy intake at a buffet meal in the obese group only (mean increase 36.6+/-9.4%, P<0.01.) High-dose ghrelin infusion increased energy intake in both groups (mean increase 20.1+/-10.6% in the lean and 70.1+/-15.5% in the obese, P<0.01 in both cases.) Ghrelin infusion increased palatability of food in the obese group. CONCLUSION: Ghrelin increases food intake in obese as well as lean subjects. Obese people are sensitive to the appetite-stimulating effects of ghrelin and inhibition of circulating ghrelin may be a useful therapeutic target in the treatment of obesity. 相似文献
108.
Cytogenetic and histologic correlations in malignant lymphoma 总被引:9,自引:0,他引:9
Koduru PR; Filippa DA; Richardson ME; Jhanwar SC; Chaganti SR; Koziner B; Clarkson BD; Lieberman PH; Chaganti RS 《Blood》1987,69(1):97-102
Although a number of studies have indicated correlations between histologic subtypes of tumors and certain nonrandom chromosome changes, cytogenetic studies of lymphoma are in an early stage compared to those of leukemia. No comprehensive analysis of available data has so far been attempted in the literature either. Here we present an analysis of chromosome changes and their correlation with subtypes of lymphoma studied by conventional histology and cell surface markers, as observed in two sets of data: a group of 65 karyotypically abnormal tumors sequentially ascertained and studied by us during the period January 1, 1984 to April 30, 1985, and a larger data set derived by combining our data with those from two published series from the University of Minnesota that are comparable to our data. These combined data, which comprise the largest data set on the cytogenetics of lymphomas assembled so far, enabled a comprehensive analysis of correlation between chromosome change and tumor histology and the patterns of chromosome instability in these tumors. We found several significant associations, some previously described and others now recognized, between nonrandom chromosome gains, breaks, translocations, and deletions and histologic subtypes of tumors that characterize lymphomas. The data indicate that finding of chromosome breaks at certain sites (eg, 8q24, 14q32, 18q21) is of diagnostic value in dealing with cases of unusual lymphoma. Furthermore, nonrandom chromosome breakage exhibited three distinct patterns that reflected three levels of etiologically relevant genetic change. 相似文献
109.
Electrical and mechanical alternation in pericardial effusion 总被引:3,自引:0,他引:3
110.