全文获取类型
收费全文 | 38144篇 |
免费 | 2690篇 |
国内免费 | 160篇 |
专业分类
耳鼻咽喉 | 285篇 |
儿科学 | 1111篇 |
妇产科学 | 749篇 |
基础医学 | 4707篇 |
口腔科学 | 748篇 |
临床医学 | 3664篇 |
内科学 | 8655篇 |
皮肤病学 | 566篇 |
神经病学 | 3906篇 |
特种医学 | 1164篇 |
外国民族医学 | 1篇 |
外科学 | 5595篇 |
综合类 | 545篇 |
一般理论 | 31篇 |
预防医学 | 3089篇 |
眼科学 | 742篇 |
药学 | 2645篇 |
1篇 | |
中国医学 | 54篇 |
肿瘤学 | 2736篇 |
出版年
2023年 | 237篇 |
2022年 | 354篇 |
2021年 | 727篇 |
2020年 | 487篇 |
2019年 | 713篇 |
2018年 | 821篇 |
2017年 | 636篇 |
2016年 | 689篇 |
2015年 | 828篇 |
2014年 | 1186篇 |
2013年 | 1646篇 |
2012年 | 2451篇 |
2011年 | 2741篇 |
2010年 | 1515篇 |
2009年 | 1406篇 |
2008年 | 2317篇 |
2007年 | 2625篇 |
2006年 | 2465篇 |
2005年 | 2568篇 |
2004年 | 2321篇 |
2003年 | 2213篇 |
2002年 | 2045篇 |
2001年 | 365篇 |
2000年 | 296篇 |
1999年 | 419篇 |
1998年 | 457篇 |
1997年 | 349篇 |
1996年 | 341篇 |
1995年 | 282篇 |
1994年 | 253篇 |
1993年 | 279篇 |
1992年 | 269篇 |
1991年 | 267篇 |
1990年 | 210篇 |
1989年 | 183篇 |
1988年 | 197篇 |
1987年 | 186篇 |
1986年 | 146篇 |
1985年 | 207篇 |
1984年 | 273篇 |
1983年 | 235篇 |
1982年 | 261篇 |
1981年 | 261篇 |
1980年 | 254篇 |
1979年 | 137篇 |
1978年 | 153篇 |
1977年 | 144篇 |
1976年 | 137篇 |
1974年 | 109篇 |
1973年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
991.
992.
993.
994.
Affective symptoms and quality of life in patients with voiding or storage dysfunction: Results before and after sacral neuromodulation: A prospective follow‐up study 下载免费PDF全文
995.
996.
Aortic annulus and root characteristics in severe aortic stenosis due to bicuspid aortic valve and tricuspid aortic valves: Implications for transcatheter aortic valve therapies 下载免费PDF全文
997.
Implication of different cardiac troponin I levels for clinical outcomes and prognosis of acute chest pain patients 总被引:3,自引:0,他引:3
Kontos MC Shah R Fritz LM Anderson FP Tatum JL Ornato JP Jesse RL 《Journal of the American College of Cardiology》2004,43(6):958-965
OBJECTIVES: We compared outcomes in patients with non-ST-segment elevation acute coronary syndromes (ACS) according to the degree of cardiac troponin I (cTnI) elevation. BACKGROUND: Controlled trials of high-risk patients have found that troponin elevations identify an even higher risk subset. It is unclear whether outcomes are similar among a lower risk, heterogeneous patient group. Also, few studies have reported outcomes other than myocardial infarction (MI) or death, based on the peak troponin value. METHODS: Consecutively, admitted patients without ST-segment elevation on the initial electrocardiogram underwent serial marker sampling using creatine kinase (CK), CK-MB fraction, and cTnI. Patients were grouped according to peak cTnI: negative = no detectable cTnI; low = peak greater than the lower limit of detectability but less than the optimal diagnostic value; intermediate = peak greater than or equal to the optimal diagnostic value but less than the manufacturer's suggested upper reference limit (URL); and high = peak greater than or equal to the URL. Thirty-day outcomes included cardiac death, MI based on CK-MB, revascularization, significant disease, and a reversible defect on stress testing. Six-month mortality was also determined. Negative evaluations for ischemia included nonsignificant disease, no reversible stress defect, and negative rest perfusion imaging. RESULTS: Of the 4,123 patients admitted, 893 (22%) had detectable cTnI values. Cardiac events and positive test results at 30 days and 6-month mortality increased significantly with increasing cTnI values. Negative evaluations for ischemia were significantly and inversely related to peak cTnI values. Although adverse events were significantly more common in patients with a low cTnI value than in those with negative cTnI, negative evaluations for ischemia were frequent. CONCLUSIONS: Increased cTnI values are associated with worse outcomes. Although low cTnI values are associated with adverse events, they do not have the same implication as higher cTnI values, and nonischemic evaluations are frequent. 相似文献
998.
999.
Volkmer JP Sahoo D Chin RK Ho PL Tang C Kurtova AV Willingham SB Pazhanisamy SK Contreras-Trujillo H Storm TA Lotan Y Beck AH Chung BI Alizadeh AA Godoy G Lerner SP van de Rijn M Shortliffe LD Weissman IL Chan KS 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(6):2078-2083
Current clinical judgment in bladder cancer (BC) relies primarily on pathological stage and grade. We investigated whether a molecular classification of tumor cell differentiation, based on a developmental biology approach, can provide additional prognostic information. Exploiting large preexisting gene-expression databases, we developed a biologically supervised computational model to predict markers that correspond with BC differentiation. To provide mechanistic insight, we assessed relative tumorigenicity and differentiation potential via xenotransplantation. We then correlated the prognostic utility of the identified markers to outcomes within gene expression and formalin-fixed paraffin-embedded (FFPE) tissue datasets. Our data indicate that BC can be subclassified into three subtypes, on the basis of their differentiation states: basal, intermediate, and differentiated, where only the most primitive tumor cell subpopulation within each subtype is capable of generating xenograft tumors and recapitulating downstream populations. We found that keratin 14 (KRT14) marks the most primitive differentiation state that precedes KRT5 and KRT20 expression. Furthermore, KRT14 expression is consistently associated with worse prognosis in both univariate and multivariate analyses. We identify here three distinct BC subtypes on the basis of their differentiation states, each harboring a unique tumor-initiating population. 相似文献
1000.
Evaluation of 24-locus MIRU-VNTR in extrapulmonary specimens: study from a tertiary centre in Mumbai
Genotyping of Mycobacterium tuberculosis isolates is a useful tool for epidemiological control of tuberculosis (TB) and phylogenetic exploration of the pathogen. There is a lack of information on the discriminatory power of standard 24-locus mycobacterial interspersed repetitive unit (MIRU) - variable number tandem repeats (VNTR) in India, which has the highest tuberculosis (TB) burden worldwide. Therefore, we assessed its utility on 69 M.?tuberculosis (MTB) isolates from patients with extrapulmonary tuberculosis, in comparison to standard insertion sequence (IS) 6110-Restriction fragment length polymorphism (RFLP) fingerprinting and spoligotyping. IS6110-RFLP (HGDI, 0.9987) identified a single cluster of 3 (4.3%) single-copy IS6110 isolates. Spoligotyping showed 69.5% clustering (HGDI, 0.8857). In contrast, MIRU-VNTR analysis identified 69 (100%) unique strains (HGDI, 1.0000). Within the study limits, this observed high discriminatory power suggests that 24-locus MIRU-VNTR genotyping could potentially be used to study long-term transmission of MTB infection in Mumbai. Moreover, high congruence between the MIRU-VNTR-based and spoligotyping-based strain groupings suggests that CAS, EAI and Beijing are the predominant strain lineages in the Mumbai TB patient population. The Beijing lineage isolates were found to be more significantly associated with multi-drug resistance (p?0.01) than CAS and EAI lineages. 相似文献