全文获取类型
收费全文 | 4644篇 |
免费 | 260篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 137篇 |
妇产科学 | 105篇 |
基础医学 | 561篇 |
口腔科学 | 92篇 |
临床医学 | 433篇 |
内科学 | 904篇 |
皮肤病学 | 93篇 |
神经病学 | 436篇 |
特种医学 | 115篇 |
外科学 | 580篇 |
综合类 | 21篇 |
一般理论 | 4篇 |
预防医学 | 515篇 |
眼科学 | 127篇 |
药学 | 283篇 |
中国医学 | 4篇 |
肿瘤学 | 491篇 |
出版年
2023年 | 43篇 |
2022年 | 82篇 |
2021年 | 182篇 |
2020年 | 121篇 |
2019年 | 150篇 |
2018年 | 170篇 |
2017年 | 124篇 |
2016年 | 137篇 |
2015年 | 140篇 |
2014年 | 186篇 |
2013年 | 236篇 |
2012年 | 375篇 |
2011年 | 362篇 |
2010年 | 223篇 |
2009年 | 211篇 |
2008年 | 271篇 |
2007年 | 324篇 |
2006年 | 299篇 |
2005年 | 261篇 |
2004年 | 222篇 |
2003年 | 233篇 |
2002年 | 165篇 |
2001年 | 27篇 |
2000年 | 26篇 |
1999年 | 28篇 |
1998年 | 46篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1970年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有4924条查询结果,搜索用时 187 毫秒
61.
62.
E. Leighton Durham Hee Jung Jeong Tyler M. Moore Randolph M. Dupont Carlos Cardenas-Iniguez Zaixu Cui Farrah E. Stone Marc G. Berman Benjamin B. Lahey Antonia N. Kaczkurkin 《Neuropsychopharmacology》2021,46(7):1333
Childhood is an important time for the manifestation of psychopathology. Psychopathology is characterized by considerable comorbidity which is mirrored in the underlying neural correlates of psychopathology. Both common and dissociable variations in brain volume have been found across multiple mental disorders in adult and youth samples. However, the majority of these studies used samples with broad age ranges which may obscure developmental differences. The current study examines associations between regional gray matter volumes (GMV) and psychopathology in a large sample of children with a narrowly defined age range. We used data from 9607 children 9–10 years of age collected as part of the Adolescent Brain Cognitive DevelopmentSM Study (ABCD Study®). A bifactor model identified a general psychopathology factor that reflects common variance across disorders and specific factors representing internalizing symptoms, ADHD symptoms, and conduct problems. Brain volume was acquired using 3T MRI. After correction for multiple testing, structural equation modeling revealed nearly global inverse associations between regional GMVs and general psychopathology and conduct problems, with associations also found for ADHD symptoms (pfdr-values ≤ 0.048). Age, sex, and race were included as covariates. Sensitivity analyses including total GMV or intracranial volume (ICV) as covariates support this global association, as a large majority of region-specific results became nonsignificant. Sensitivity analyses including income, parental education, and medication use as additional covariates demonstrate largely convergent results. These findings suggest that globally smaller GMVs are a nonspecific risk factor for general psychopathology, and possibly for conduct problems and ADHD as well.Subject terms: Human behaviour, Risk factors, Neuroscience 相似文献
63.
Antonia Raya-Tena Maria Isabel Fernndez-San-Martín Jaume Martín-Royo Rocío Casaas Grup Psicodep María Francisca Jimnez-Herrera 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2021,53(2)
ObjetivoEl objetivo del estudio es describir la percepción de la calidad de vida relacionada con la salud de personas con depresión y comorbilidad física bajo una perspectiva de género. Se incluyeron 380 individuos mayores de 49 años con, al menos, una patología de las siguientes: diabetes, enfermedad obstructiva pulmonar crónica y cardiopatía isquémica, reclutadas en 31 equipos de atención primaria de Cataluña. La calidad de vida se midió con la escala EuroQol (EQ-5D). Además, se recogieron variables sociodemográficas, gravedad de depresión, índice de privación económica y ámbito de residencia. Se evaluó la relación ajustada entre el sexo y las dimensiones de calidad de vida, mediante una regresión logística multivariante.ResultadosEl 81,3% fueron mujeres; la media de edad fue de 68,4 años (DE: 8,8), La media de la escala visual analógica fue de 57,8 (DE: 17,4) en hombres y 55,8 (DE: 18,6) en mujeres. La media del EQ-Health Index fue de 0,74 (DE: 0,17) en hombres y 0,65 (DE: 0,21) en mujeres (p = 0,001). La probabilidad de presentar problemas en las dimensiones del EQ-5D mostró el sexo como factor de más peso (mujer = 1/hombre = 0) en: autocuidado OR: 2,29 (IC 95% 1,04 a 5,07) y actividades cotidianas OR: 3,09 (IC 95% 1,67 a 5,71). La movilidad se asoció con la edad OR: 1,87 (IC 95% 1,22 a 2,86), el ámbito de residencia con el dolor OR: 2,51 (IC 95% 1,18 a 5,34) y el Beck Depression Inventory (BDI) con la ansiedad/depresión OR: 4,77 (IC 95% 1,77 a 12,88).ConclusiónLa percepción en la calidad de vida de las mujeres con depresión y comorbilidad física es inferior a la de los hombres, siendo en ambos casos inferior a la de población general.Palabras clave: Calidad de vida, Depresión, Comorbilidad física, Género, Atención Primaria 相似文献
64.
Laura Pérez-Egido María Antonia García-Casillas Isabel Simal María Fanjul Agustin Cañizo Julio A. Cerdá Beatriz Fernandez Manuel de la Torre Javier Ordoñez Juan Carlos de Agustin 《Journal of pediatric surgery》2019,54(4):693-695
Introduction
New digital thoracic drainage systems allow an objective measurement of air leakage. They have proven their usefulness in the postoperative thoracic surgery in adults, but there is little experience with its use in the pediatric population. The objective of our study is to analyze their safety and effectiveness in the postoperative period of the pediatric patients.Method
A prospective consecutive observational study was done. All patients submitted to pulmonary resection between 2011 and 2017 and in whom digital thoracic drainage system was used (Thopaz Chest Drain System, Medela, Switzerland) were prospectively enrolled in this study. We analyzed variables: duration of chest tube (CT), days of hospitalization and radiographs in the immediate postoperative period related to the presence of CT. This group was compared with a historical cohort of patients (from 2011 to 2015) with a pulmonary resection in whom the traditional thoracic drainage was used. For the statistical analysis, the Mann–Whitney U-Test was used for independent samples.Result
Twenty-six patients were included, Digital drainage system was used in13 patients and traditional drainage was used in 13 patients. The median age was 18?months (12?days-14?years). The mean number of days with the chest tube was 1.69?±?0.6 in digital drainage group versus 5.38?±?4?days in traditional drainage group (p?<?0.05) The mean number of postoperative radiographs was 2.8?±?1.1 in digital drainage group versus 6.23?±?5.2 radiographs in traditional drainage group (p?<?0.05). The average hospital stay in digital drainage group was 5.69?±?2.7?days versus 7?±?4.7?days in the traditional drainage group (p?>?0.05). No complications related to the use of digital drainage group were registered.Conclusion
The digital thoracic drainage systems provide an objective measurement of air leakage, allowing early chest tube removal and decreasing the number of radiographs performed postoperatively. Its use in the pediatric population appears to be safe and potentially beneficial.Level of evidence
II. 相似文献65.
66.
Amina Amadou Heinz Freisling Mazda Jenab Konstantinos K. Tsilidis Antonia Trichopoulou Paolo Boffetta Bethany Van Guelpen Olatz Mokoroa Tom Wilsgaard Frank Kee Ben Schttker Jos M. Ordez-Mena Satu Mnnist Stefan Sderberg Roel C. H. Vermeulen J. Ramn Quirs Linda M. Liao Rashmi Sinha Kari Kuulasmaa Hermann Brenner Isabelle Romieu 《British journal of cancer》2021,124(11):1882
Background We investigated whether associations between prevalent diabetes and cancer risk are pertinent to older adults and whether associations differ across subgroups of age, body weight status or levels of physical activity.Methods We harmonised data from seven prospective cohort studies of older individuals in Europe and the United States participating in the CHANCES consortium. Cox proportional hazard regression was used to estimate the associations of prevalent diabetes with cancer risk (all cancers combined, and for colorectum, prostate and breast). We calculated summary risk estimates across cohorts using pooled analysis and random-effects meta-analysis.Results A total of 667,916 individuals were included with an overall median (P25–P75) age at recruitment of 62.3 (57–67) years. During a median follow-up time of 10.5 years, 114,404 total cancer cases were ascertained. Diabetes was not associated with the risk of all cancers combined (hazard ratio (HR) = 0.94; 95% confidence interval (CI): 0.86–1.04; I2 = 63.3%). Diabetes was positively associated with colorectal cancer risk in men (HR = 1.17; 95% CI: 1.08–1.26; I2 = 0%) and a similar HR in women (1.13; 95% CI: 0.82–1.56; I2 = 46%), but with a confidence interval including the null. Diabetes was inversely associated with prostate cancer risk (HR = 0.81; 95% CI: 0.77–0.85; I2 = 0%), but not with postmenopausal breast cancer (HR = 0.96; 95% CI: 0.89–1.03; I2 = 0%). In exploratory subgroup analyses, diabetes was inversely associated with prostate cancer risk only in men with overweight or obesity.Conclusions Prevalent diabetes was positively associated with colorectal cancer risk and inversely associated with prostate cancer risk in older Europeans and Americans.Subject terms: Risk factors, Cancer epidemiology 相似文献
67.
68.
Andreana Marino Simona Pergolizzi Eugenia R. Lauriano Giuseppe Santoro Francesca Spataro Francesco Cimino Antonio Speciale Antonia Nostro Giuseppe Bisignano 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(2):163-168
The Toll‐Like Receptor 2 (TLR2) plays an active and important role in Staphylococcus aureus‐induced chronic ocular inflammation. The aim of this study was to investigate the expression and function of TLR2 of corneal stromal cells in ex vivo rabbit model of S. aureus keratitis. Corneal buttons with sclera rims placed in an ex vivo air‐interface organ culture were assigned to two groups: corneas with epithelial and stromal abrasions. Each group was then divided into two sub‐groups exposed to UV‐killed S. aureus ATCC 6538P and S. aureus ATCC 29213, respectively. TLR2 and IL‐8 mRNA expressions were analyzed by quantitative real‐time RT‐PCR. TLR2 localization was visualized by immunofluorescence analysis. The results demonstrated that TLR2 and IL‐8 mRNA were significantly expressed in the stromal cells of the groups exposed to S. aureus strains. Moreover, it has been demonstrated that, after corneal injury, keratocytes differentiated into myofibroblasts became able to express TLR2 only when exposed to S. aureus. Identification of mechanisms regulation of corneal TLRs may lead to development of therapeutic interventions aimed at controlling corneal inflammation. This ex vivo model can be used to clarify the molecular events of bacterial‐corneal tissue interactions and their inflammatory consequences. 相似文献
69.
70.