全文获取类型
收费全文 | 3139篇 |
免费 | 189篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 44篇 |
妇产科学 | 69篇 |
基础医学 | 427篇 |
口腔科学 | 23篇 |
临床医学 | 276篇 |
内科学 | 1003篇 |
皮肤病学 | 65篇 |
神经病学 | 249篇 |
特种医学 | 62篇 |
外科学 | 238篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 285篇 |
眼科学 | 35篇 |
药学 | 165篇 |
中国医学 | 3篇 |
肿瘤学 | 348篇 |
出版年
2023年 | 12篇 |
2022年 | 54篇 |
2021年 | 108篇 |
2020年 | 56篇 |
2019年 | 109篇 |
2018年 | 86篇 |
2017年 | 74篇 |
2016年 | 61篇 |
2015年 | 67篇 |
2014年 | 112篇 |
2013年 | 144篇 |
2012年 | 242篇 |
2011年 | 258篇 |
2010年 | 146篇 |
2009年 | 139篇 |
2008年 | 211篇 |
2007年 | 206篇 |
2006年 | 205篇 |
2005年 | 174篇 |
2004年 | 175篇 |
2003年 | 140篇 |
2002年 | 166篇 |
2001年 | 42篇 |
2000年 | 26篇 |
1999年 | 44篇 |
1998年 | 33篇 |
1997年 | 28篇 |
1996年 | 35篇 |
1995年 | 28篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 29篇 |
1991年 | 19篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 14篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有3338条查询结果,搜索用时 156 毫秒
81.
Montserrat Reyes Gonzalo Rojas-Alcayaga Andrea Maturana Juan-Pablo Aitken Carolina Rojas Ana-Verónica Ortega 《Medicina oral, patología oral y cirugía bucal》2015,20(5):e540-e546
Background
Deregulation of ?-catenin is associated with malignant transformation; however, its relationship with potentially malignant and malignant oral processes is not fully understood. The aim of this study was to determine and compare the nuclear ?-catenin expression in oral dysplasia and oral squamous cell carcinoma (OSCC).Material and Methods
Cross sectional study. Immunodetection of ?-catenin was performed on 72 samples, with the following distribution: 21 mild dysplasia, 12 moderate dysplasia, severe dysplasia 3, 36 OSCC including 19 well differentiated, 15 moderately differentiated and 2 poorly differentiated. Through microscopic observation the number of positive cells per 1000 epithelial cells was counted. For the statistical analysis, the Kruskal Wallis test was used.Results
Nuclear expression of ?-catenin was observed in all samples with severe and moderate dysplasia, with a median of 267.5, in comparison to mild dysplasia whose median was 103.75. Only 10 samples (27.7%) with OSCC showed nuclear expression, with statistically significant differences between groups (p < 0.05).Conclusions
Our results are consistent with most of the reports which show increased presence of ?-catenin in severe and moderate dysplasia compared to mild dysplasia; however the expression of nuclear ?-catenin decreased after starting the invasive neoplastic process. This suggests a role for this protein in the progression of dysplasia and early malignant transformation to OSCC. Immunodetection of ?-catenin could be a possible immune marker in the detection of oral dysplasia. Key words:Oral squamous cell carcinoma (OSCC), ?-catenin, oral dysplasia. 相似文献82.
Sergi Valero Constanza Daigre Laia Rodríguez-Cintas Carmen Barral Montserrat Gomà-i-Freixanet Marc Ferrer Miquel Casas Carlos Roncero 《Comprehensive psychiatry》2014
Objective
Neuroticism and impulsivity are the personality variables most consistently associated with drug-dependent patients. To date, no data mining procedures have been applied to explore the differential role of personality variables in this population.Methods
The personality profile of 336 drug-dependent patients was compared with that of a sample of community participants in the context of a decision tree learning approach using the Alternative Five Factor Model. The resulting discriminant model was cross-validated.Results
Neuroticism and impulsivity were the most relevant variables in the resulting model, but their association appeared to be hierarchically organized. In the personality characterization of these patients, neuroticism became the main discriminant dimension, whereas impulsivity played a differential role, explained by means of an interaction effect. Decision tree learning models appear to be a heuristic theoretical and empirical approximation to the study of relevant variables, such as personality traits, in drug-dependency research. 相似文献83.
Ortega E Gilabert R Nuñez I Cofán M Sala-Vila A de Groot E Ros E 《Atherosclerosis》2012,220(1):275-281
ObjectiveRelationship of high sensitivity C-reactive protein (hsCRP) with Metabolic Syndrome (MetS) is well documented in many populations, but comprehensive data is lacking in Indian population. Thus, we set out to investigate the association of hsCRP levels with MetS and its features and the effect of obesity and insulin resistance on this association in urban Indians.MethodsThis is a cross-sectional study that included 9517 subjects comprising 4066 subjects with MetS. MetS was defined according to the modified National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP III) criteria for Asians.ResultsMedian levels of hsCRP were considerably higher in individuals with MetS with higher levels in women compared to men. Among the features of MetS, waist circumference was most strongly correlated with hsCRP levels (r = 0.28) and contributed maximally (β = 0.025 mg/l ln hsCRP, P = 7.4 × 10?147). Subjects with high risk hsCRP levels (>3 mg/l) were at high risk of MetS (OR (95% CI) = 1.65(1.41–1.92), P = 1.7 × 10?10). Risk of MetS increased in a dose dependent manner from low risk to high risk hsCRP category with increase in BMI and HOMA-IR.ConclusionsOur findings suggest that hsCRP predicts the risk of MetS, independent of obesity and insulin resistance, and therefore, can be a valuable tool to aid the identification of individuals at risk of MetS. The study provides a lead for future investigation for effects of hsCRP, obesity, and insulin resistance on MetS in this population. 相似文献
84.
85.
Gaudet MM Falk RT Stevens RD Gunter MJ Bain JR Pfeiffer RM Potischman N Lissowska J Peplonska B Brinton LA Garcia-Closas M Newgard CB Sherman ME 《The Journal of clinical endocrinology and metabolism》2012,97(9):3216-3223
Context: Endometrial cancer is associated with metabolic disturbances related to its underlying risk factors, including obesity and diabetes. Identifying metabolite biomarkers associated with endometrial cancer may have value for early detection, risk assessment, and understanding etiology. Objective: The objective of the study was to evaluate the reliable measurement of metabolites in epidemiological studies with nonstandardized blood collection; confirm previously reported correlations of metabolites with body size; and assess differences in metabolite levels between cases and controls. Design: This was the Polish Endometrial Cancer Study (2001-2003). Setting: This study was a population-based case-control study. Patients: Patients included 250 cases and 250 controls. Intervention: The intervention included the measurement of serum metabolite levels of 15 amino acids, 45 acylcarnitines, and nine fatty acids. Main Outcome Measure: The main outcome measure was endometrial cancer. Results: Body mass index was correlated with levels of valine (r = 0.26, P = 3.4 × 10(-5)), octenoylcarnitine (r = 0.24, P = 1.5 × 10(-4)), palmitic acid (r = 0.26, P = 4.4 × 10(-5)), oleic acid (r = 0.28, P = 9.9 × 10(-6)), and stearic acid (r = 0.26, P = 2.9 × 10(-5)) among controls. Only stearic acid was inversely associated with endometrial cancer case status (quartile 4 vs. quartile 1: odds ratio 0.37, 95% confidence interval 0.20-0.69, P for trend = 1.2 × 10(-4)). Levels of the C5-acylcarnitines, octenoylcarnitine, decatrienoylcarnitine, and linoleic acid were significantly lower in cases than controls (odds ratios ranged from 0.21 to 0.38). Conclusions: These data demonstrate that previously reported variations in metabolomic profiles with body mass index can be replicated in population-based studies with nonfasting blood collection protocols. We also provide preliminary evidence that large differences in metabolite levels exist between cases and controls, independent of body habitus. Our findings warrant assessment of metabolic profiles, including the candidate markers identified herein, in prospectively collected blood samples to define biomarkers and etiological factors related to endometrial cancer. 相似文献
86.
López C Baumann T Costa D López-Guerra M Navarro A Gómez C Arias A Muñoz C Rozman M Villamor N Colomer D Montserrat E Campo E Carrió A 《British journal of haematology》2012,156(5):612-618
The analysis of chromosomal abnormalities provides significant prognostic information in patients with chronic lymphocytic leukaemia (CLL), a disease with a highly heterogeneous clinical course. Chromosomal abnormalities commonly found are trisomy 12, del(13)(q14), del(11)(q22-23), del(17)(p13) and del(6)(q21). Translocations are present in some patients and affect regions recurrently involved in CLL. This report describes the clinical and pathological characteristics of four CLL patients showing a new recurrent chromosomal abnormality dic(8;17)(p11;p11), that implied loss of the TP53 gene in all cases. In addition, TP53 gene was mutated in three out of four patients. Mechanically, Low Copy Repeats (LCR) in 17p12 and 8p11 may explain the origin of the translocation by non-allelic homologous recombination (NAHR). Isolated dic(8;17)(p11;p11) in patients with mutated IGHV genes status may not have the same prognostic impact as other mutations or deletions affecting the TP53 gene. Larger series are needed to better evaluate the clinical impact of this chromosomal aberration during the course of the disease. 相似文献
87.
88.
89.
90.
Montserrat Solá MD José A. Alberro MD Manuel Fraile MD Pilar Santesteban MD Manuel Ramos MD Rafael Fabregas MD Antonio Moral MD Blas Ballester MD Sergi Vidal MD 《Annals of surgical oncology》2013,20(1):120-127