全文获取类型
收费全文 | 2110篇 |
免费 | 131篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 84篇 |
妇产科学 | 51篇 |
基础医学 | 257篇 |
口腔科学 | 32篇 |
临床医学 | 272篇 |
内科学 | 419篇 |
皮肤病学 | 16篇 |
神经病学 | 234篇 |
特种医学 | 119篇 |
外科学 | 246篇 |
综合类 | 51篇 |
一般理论 | 2篇 |
预防医学 | 220篇 |
眼科学 | 16篇 |
药学 | 173篇 |
中国医学 | 3篇 |
肿瘤学 | 135篇 |
出版年
2022年 | 11篇 |
2021年 | 41篇 |
2020年 | 20篇 |
2019年 | 27篇 |
2018年 | 40篇 |
2017年 | 27篇 |
2016年 | 40篇 |
2015年 | 40篇 |
2014年 | 48篇 |
2013年 | 75篇 |
2012年 | 78篇 |
2011年 | 86篇 |
2010年 | 70篇 |
2009年 | 60篇 |
2008年 | 70篇 |
2007年 | 129篇 |
2006年 | 77篇 |
2005年 | 103篇 |
2004年 | 85篇 |
2003年 | 71篇 |
2002年 | 100篇 |
2001年 | 68篇 |
2000年 | 48篇 |
1999年 | 44篇 |
1998年 | 62篇 |
1997年 | 46篇 |
1996年 | 37篇 |
1995年 | 40篇 |
1994年 | 37篇 |
1993年 | 46篇 |
1992年 | 33篇 |
1991年 | 32篇 |
1990年 | 52篇 |
1989年 | 45篇 |
1988年 | 42篇 |
1987年 | 47篇 |
1986年 | 49篇 |
1985年 | 40篇 |
1984年 | 35篇 |
1983年 | 20篇 |
1982年 | 21篇 |
1981年 | 18篇 |
1980年 | 21篇 |
1979年 | 20篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 8篇 |
1974年 | 11篇 |
1973年 | 8篇 |
1968年 | 8篇 |
排序方式: 共有2340条查询结果,搜索用时 15 毫秒
51.
Continuous monitoring of mixed venous oxygen saturation in patients with acute myocardial infarction 总被引:1,自引:0,他引:1
Continuous measurement of mixed venous oxygen saturation (SvO2) has been suggested as an adjunct in monitoring critically ill patients. We evaluated SvO2 monitoring in 24 patients suffering from complicated myocardial infarctions. Cardiac output and arterial lactate levels were measured when there were persistent 5 percent changes in SvO2, and otherwise, every 12 hours or as indicated clinically. Increases in SvO2 by 5 and 10 percent corresponded with an increase in cardiac index in 78.5 percent and 75 percent of measurements, respectively. Decreases in SvO2 by 5 and 10 percent corresponded with decreases in cardiac index in 45.5 percent and 61 percent of measurements. Twenty percent changes in cardiac index showed dissimilar directional changes with SvO2 in 62 percent of cases. Arterial blood lactate levels correlated poorly with SvO2. Survivors had significantly higher mean SvO2 and cardiac indices than nonsurvivors (p less than 0.01). The clinical management of patients with myocardial infarction may not be altered in view of the limitations of SvO2 in reflecting tissue hypoxia. We conclude that continuous monitoring of SvO2 may not be a sensitive measure of cardiac output after acute myocardial infarction. 相似文献
52.
Diagnosis and Management of Insomnia in Older People 总被引:4,自引:1,他引:4
53.
BRCA1 and BRCA2 are major breast cancer susceptibility genes. Nineteen single nucleotide polymorphisms (SNPs) at 18 loci have been associated with breast cancer. We aimed to determine whether these predict breast cancer incidence in women with BRCA1/BRCA2 mutations. BRCA1/2 mutation carriers identified through the Manchester genetics centre between 1996 and 2011 were included. Using published odds ratios (OR) and risk allele frequencies, we calculated an overall breast cancer risk SNP score (OBRS) for each woman. The relationship between OBRS and age at breast cancer onset was investigated using the Cox proportional hazards model, and predictive ability assessed using Harrell's C concordance statistic. In BRCA1 mutation carriers we found no association between OBRS and age at breast cancer onset: OR for the lowest risk quintile compared to the highest was 1.20 (95% CI 0.82–1.75, Harrell's C = 0.54), but in BRCA2 mutation carriers the association was significant (OR for the lowest risk quintile relative to the highest was 0.47 (95% CI 0.33–0.69, Harrell's C = 0.59). The 18 validated breast cancer SNPs differentiate breast cancer risks between women with BRCA2 mutations, but not BRCA1. It may now be appropriate to use these SNPs to help women with BRCA2 mutations make maximally informed decisions about management options. 相似文献
54.
A non-human primate antiserum was prepared to acute lymphoblastic leukemia of T-cell phenotype (T-ALL) and, after absorptions with normal blood elements, reacted by immunofluorescence and microcytotoxicity to all the T-ALL tested. In addition, the antiserum reacted with cells from about 70% of the common ALL studied and immunoprecipitated the common ALL antigen of 100,000 daltons. However, when the anti-T-ALL serum was absorbed with with lymphoblasts from common ALL, it failed to react with common ALL lymphoblasts, yet reacted significantly with cells from patients with T-ALL phenotype and defined a 100,000-dalton membrane component not found on common ALL lymphoblasts. In addition, sequential immunoprecipitation of 125I-labeled T-ALL membranes by anti- common-ALL serum followed by anti-T-ALL serum detected the T-ALL membrane component of 100,000 daltons that was not found on common ALL. Thus, our results demonstrate the presence of of a unique human T-ALL antigen present on all T-ALL distinct from the common ALL antigen. 相似文献
55.
Confirmation of Correlations and Common Quantitative Trait Loci Between Neurotensin Receptor Density and Hypnotic Sensitivity to Ethanol 总被引:3,自引:0,他引:3
V. Gene Erwin Vaughn M. Gehle Kirsten Davidson Richard A. Radcliffe 《Alcoholism, clinical and experimental research》2001,25(12):1699-1707
BACKGROUND: In previous studies, genetic correlations were observed between hypnotic sensitivity to ethanol and high-affinity neurotensin receptor (NTS1) binding. Provisional quantitative trait loci (QTLs) were identified for these traits, and some of these QTLs were found on common chromosomal regions. In continued efforts to examine the relationship between NTS1 binding capacity and hypnotic sensitivity to ethanol, studies were designed to confirm correlations between NTS1 densities in the brain, duration of ethanol-induced loss of righting reflex (LORR), and blood ethanol concentrations at regain of righting reflex (BECRR). Another purpose of the study was to confirm QTLs for these traits. METHODS: ILS X ISS F2 mice and HAS X LAS F2 rats as well as the progenitors were tested for LORR, BECRR, and NTS1 densities. Phenotypic correlations were calculated between LORR and BECRR and between these measures and NTS1 densities in striatum from both mice and rats. The F2 mice were genotyped by using polymorphic markers for five previously reported QTLs for LORR to confirm QTLs for BECRR and NTS1 densities in striatum, ventral midbrain, and frontal cortex. RESULTS: Phenotypic correlations were found between LORR and BECRR (r = -0.66 to -0.74, p < 10(-9)) and between these measures and NTS1 densities in striatum (r = 0.28-0.38, p < 10(-2)) from both mice and rats. QTLs for LORR and BECRR (lod score = 2-6) were found in common regions of chromosomes 1, 2, and 15. By using the combined results from a previous LSXSS RI study and the current results, a suggestive QTL (lod score = 3.1) for striatal NTS1 receptor densities was found on chromosome 15 at approximately 60 cM, in the same region as the chromosome 15 LORR/BECRR QTL. CONCLUSIONS: The results are in agreement with previously reported correlations and QTLs for NTS1 receptor densities and measures of hypnotic sensitivity to ethanol in mice and extend those correlations to another species, the rat. These findings support a role for NTS1 in genetically mediated differences in hypnotic sensitivity to ethanol. 相似文献
56.
57.
Abstract: The prevalence of Parkinson’s disease (PD) is expected to double over the next 20 years owing to the increase in life expectancy. This progressive disease has several implications relating to oral health, and many are manageable with proper awareness and knowledge about the disease. This article reviews the epidemiology, pathophysiology, and characteristics of PD, as well as the treatments and oral health considerations to enable dental hygienists to undertake an informed approach to patient management strategies and provide optimal care. 相似文献
58.
J Tang DJ Humes E Gemmil NT Welch SL Parsons JA Catton 《Annals of the Royal College of Surgeons of England》2013,95(5):323-328
Introduction
The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.Methods
Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.Results
There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).Conclusions
The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality. 相似文献59.
JEFF S. HEALEY M.D. M.Sc. LORNE J. GULA M.D. DAVID H. BIRNIE M.D. LAWRENCE STERNS M.D. STUART J. CONNOLLY M.D. JOHN SAPP M.D. EUGENE CRYSTAL M.D. CHRIS SIMPSON M.D. DEREK V. EXNER M.D. M.P.H. TERESA KUS M.D. FRANCOIS PHILIPPON M.D. GEORGE WELLS Ph.D. ANTHONY SL. TANG M.D. 《Journal of cardiovascular electrophysiology》2012,23(12):1313-1316
Comparing ICD Implantation with and Without Intraoperative Defibrillation Testing. Introduction: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT. Methods: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT. Results: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all‐cause mortality occurred in 10% of patients in the no‐DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21–1.31, P = 0.14). Conclusions: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1313‐1316, December 2012) 相似文献
60.