全文获取类型
收费全文 | 4376篇 |
免费 | 299篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 122篇 |
妇产科学 | 96篇 |
基础医学 | 605篇 |
口腔科学 | 77篇 |
临床医学 | 400篇 |
内科学 | 998篇 |
皮肤病学 | 87篇 |
神经病学 | 435篇 |
特种医学 | 103篇 |
外科学 | 452篇 |
综合类 | 23篇 |
一般理论 | 2篇 |
预防医学 | 373篇 |
眼科学 | 110篇 |
药学 | 367篇 |
中国医学 | 12篇 |
肿瘤学 | 372篇 |
出版年
2024年 | 9篇 |
2023年 | 82篇 |
2022年 | 142篇 |
2021年 | 247篇 |
2020年 | 138篇 |
2019年 | 156篇 |
2018年 | 202篇 |
2017年 | 116篇 |
2016年 | 149篇 |
2015年 | 149篇 |
2014年 | 216篇 |
2013年 | 255篇 |
2012年 | 389篇 |
2011年 | 370篇 |
2010年 | 207篇 |
2009年 | 177篇 |
2008年 | 281篇 |
2007年 | 289篇 |
2006年 | 228篇 |
2005年 | 219篇 |
2004年 | 171篇 |
2003年 | 139篇 |
2002年 | 122篇 |
2001年 | 25篇 |
2000年 | 23篇 |
1999年 | 21篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 13篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1971年 | 3篇 |
排序方式: 共有4706条查询结果,搜索用时 15 毫秒
41.
42.
Hélder Pereira Rita Calé Fausto J. Pinto Ernesto Pereira Daniel Caldeira Sofia Mello Sílvia Vitorino Manuel de Sousa Almeida Jorge Mimoso 《Revista portuguesa de cardiologia》2018,37(5):409-421
Introduction and Aims
Shorter patient delays are associated with a better prognosis for patients diagnosed with ST-segment elevation myocardial infarction (STEMI). This study aimed to identify predictors of patient delay in the Portuguese population.Methods
Data on 994 patients with suspected STEMI of less than 12 hours’ duration and referred for primary percutaneous coronary intervention (pPCI) and admitted to 18 Portuguese interventional cardiology centers were collected for a one-month period every year from 2011 to 2015. Univariate and multivariate linear regression models were used to identify predictors of patient delay.Results
No significant differences were observed in patient delay over the course of the survey. The multivariate analysis identified five predictors of patient delay: age ≥75 years (exp[beta] 1.28; 95% CI 1.10-1.50; p=0.001), symptom onset between 0:00 and 8:00 a.m. (exp[beta] 1.26; 95% CI 1.10-1.45; p=0.001), and attending a primary care unit before first medical contact (exp[beta] 1.75; 95% CI 1.41-2.16; p<0.001) predicted longer patient delay, while calling the national medical emergency number (112) (exp[beta] 0.84; 95% CI 0.71-1.00; p=0.045) and transport by the emergency medical services to the pPCI facility (exp[beta] 0.71; 95% CI 0.59-0.84; p<0.001) predicted shorter patient delay.Conclusions
We identified five factors predicting patient delay, which will help in planning interventions to reduce patient delays and to improve the outcome of patients with STEMI. 相似文献43.
Carmen Barba Massimo Cossu Renzo Guerrini Giancarlo Di Gennaro Flavio Villani Luca De Palma Laura Grisotto Alessandro Consales Domenica Battaglia Nelia Zamponi Piergiorgio dOrio Martina Revay Michele Rizzi Sara Casciato Vincenzo Esposito Pier Paolo Quarato Roberta Di Giacomo Giuseppe Didato Chiara Pastori Giusy Carfi Pavia Simona Pellacani Giulia Matta Mattia Pacetti Gianpiero Tamburrini Elisabetta Cesaroni Gabriella Colicchio Giampaolo Vatti Sofia Asioli Massimo Caulo Carlo Efisio Marras Laura Tassi 《Epilepsia》2021,62(1):128-142
44.
Dimitrios Krikelis Mattheos Bobos Georgia Karayannopoulou Liliana Resiga Sofia Chrysafi Epaminontas Samantas Dimitrios Andreopoulos Vassilios Vasiliou Elisabeta Ciuleanu George Fountzilas 《BMC clinical pathology》2013,13(1):1-15
Background
Since scarce data exist on the pathogenesis of nasopharyngeal carcinoma in Caucasian patients, we attempted to elucidate the responsible molecular pathways in this patient population.Methods
Formalin-fixed paraffin-embedded tumor tissue samples from 107 patients, diagnosed with locally-advanced nasopharyngeal carcinoma and treated with chemotherapy or chemo-radiotherapy, were analyzed by immunohistochemistry for the expression of the following proteins: E-cadherin, P-cadherin, Fascin-1, Cyclin D1, COX-2, EGFR, VEGF-A, VEGF-C, VEGFR-2, VEGFR-3, ERCC1, p53, p63, Ki67, MAPT, phospho-p44/42MAPK, PTEN, phospho-AKT, phospho-mTOR, and phospho-GSK-3β. EBER status was assessed by in situ hybridization. The majority of the cases were included in tissue microarray. All stains were performed and assessed centrally by two pathologists. The median follow-up time was 76.8 (42.3 – 99.2) months.Results
Biomolecules expressed in >90% of cases were: p53, COX-2, P-cadherin, EBER, phospho-GSK-3β, and Fascin-1. WHO II+III tumors were more frequently EBER & PTEN positive and VEGF-A negative. Advanced age was significantly associated with positive phospho-GSK-3β and ERCC1 expression; male gender with positive phospho-AKT and phospho-p44/42MAPK; and worse performance status (1 or 2) with negative Ki67, ERCC1, PTEN, and phospho-mTOR expression. Earlier disease stage was closely associated with p63, MAPT, PTEN, and Cyclin D1 positivity. Univariate Cox regression analysis highlighted Cyclin D1 as a negative prognostic factor for disease-free survival (p=0.034) and EBER as a positive one for overall survival (p=0.048). In multivariate analysis, advanced age and stage, poor performance status, and positive ERCC1 emerged as predictors of worse disease-free and overall survival, as opposed to positive phospho-mTOR. Clustering analysis defined two protein-expression groups being predictive of better overall survival (p=0.043).Conclusions
Our study is the first to examine the activation and interaction of established biomolecules and signaling pathways in Caucasian NPC patients in an effort to reveal new therapeutic targets. 相似文献45.
Pascal Büttner Dirk Dhler Sofia Korenko Sebastian Mhrlein Sebastian Bochmann Nicolas Vogel Ignacio Mínguez-Bacho Julien Bachmann 《RSC advances》2020,10(47):28225
TiO2 nanotubes generated by anodization of metallic titanium sputter-coated on indium tin oxide (ITO) substrates are used as a conductive scaffold for all solid-state Sb2S3-sensitized extremely thin absorber (ETA) solar cells. A blocking layer of TiO2 placed between Ti and ITO in combination with optimized Ti deposition and anodization conditions enables the formation of crack-free layers of straight, cylindrical TiO2 nanotubes of tunable length and diameter. ALD (atomic layer deposition) is subsequently used to coat this substrate conformally with a highly pure Sb2S3 light absorber layer under an inert atmosphere. The high absorption coefficient of Sb2S3 as compared to molecular dyes allows for the utilization of very short nanotubes, which facilitates the infiltration of the organic hole transport material and formation of a p–i–n heterojunction in an interdigitated and tunable geometry. We investigate the influence of nanotube length and of the absorber thickness to enhance the photocurrent value to twice that of planar reference structures.TiO2 nanotubes generated by anodization of metallic titanium sputter-coated on indium tin oxide (ITO) substrates are used as a conductive scaffold for all-solid-state Sb2S3-sensitized extremely thin absorber (ETA) solar cells. 相似文献
46.
47.
48.
Ednei Luiz Antonio Andrey Jorge Serra Alexandra Alberta dos Santos Stella Sousa Vieira Jairo Montemor Augusto Silva Amanda Yoshizaki Renato Rodrigues Sofia Paulo José Ferreira Tucci 《Brazilian Journal Of Cardiovascular Surgery》2015,30(1):70-76
Objective
An unclear issue is whether gender may influence at cardiac remodeling after myocardial infarction (MI). We evaluated left ventricle remodeling in female and male rats post-MI.Methods
Rats were submitted to anterior descending coronary occlusion. Echocardiographic evaluations were performed on the first and sixth week post-occlusion to determine myocardial infarction size and left ventricle systolic function (FAC, fractional area change). Pulsed Doppler was applied to analyze left ventricle diastolic function using the following parameters: E wave, A wave, E/A ratio. Two-way ANOVA was applied for comparisons, complemented by the Bonferroni test. A P≤=0.05 was considered significant.Results
There were no significant differences between genders for morphometric parameters on first (MI [Female (FE): 44.0±5.0 vs. Male (MA): 42.0±3.0%]; diastolic [FE: 0.04±0.003 vs. MA: 0.037±0.005, mm/g] and systolic [FE: 0.03±0.0004 vs. MA: 0.028±0.005, mm/g] diameters of left ventricle) and sixth (MI [FE: 44.0±5.0 vs. MA: 42.0±3.0, %]; diastolic [FE: 0.043±0.01 vs. MA: 0.034±0.005, mm/g] and systolic [FE: 0.035±0.01 vs. MA: 0.027±0.005, mm/g] of LV) week. Similar findings were reported for left ventricle functional parameters on first (FAC [FE: 34.0±6.0 vs. MA: 32.0±4.0, %]; wave E [FE: 70.0±18.0 vs. MA: 73.0±14.0, cm/s]; wave A [FE: 20.0±12.0 vs. MA: 28.0±13.0, cm/s]; E/A [FE: 4.9±3.4 vs. MA: 3.3±1.8]) and sixth (FAC [FE: 29.0±7.0 vs. MA: 31.0±7.0, %]; wave E [FE: 85.0±18.0 vs. MA: 87.0±20.0, cm/s]; wave A [FE: 20.0±11.0 vs. MA: 28.0±17.0, cm/s]; E/A [FE: 6.2±4.0 vs. MA: 4.6±3.4]) week.Conclusion
Gender does not influence left ventricle remodeling post-MI in rats. 相似文献49.
RotaFlow and CentriMag Extracorporeal Membrane Oxygenation Support Systems as Treatment Strategies for Refractory Cardiogenic Shock 下载免费PDF全文
50.
Alessandro Martorana Francesco Di Lorenzo Lorena Belli Giuseppe Sancesario Sofia Toniolo Fabrizio Sallustio Giulia Maria Sancesario Giacomo Koch 《CNS Neuroscience & Therapeutics》2015,21(12):921-925
Impaired amyloid beta (Aβ) metabolism is currently considered central to understand the pathophysiology of Alzheimer's disease (AD). Measurements of cerebrospinal fluid Aβ levels remain the most useful marker for diagnostic purposes and to individuate people at risk for AD. Despite recent advances criticized the direct role in neurodegeneration of cortical neurons, Aβ is considered responsible for synaptopathy and impairment of neurotransmission and therefore remains the major trigger of AD and future pharmacological treatment remain Aβ oriented. However, experimental and clinical findings showed that Aβ peptides could have a wider range of action responsible for cell dysfunction and for appearance of clinico‐pathological entities different from AD. Such findings may induce misunderstanding of the real role played by Aβ in AD and therefore strengthen criticism on its centrality and need for CSF measurements. Aim of this review is to discuss the role of CSF Aβ levels in light of experimental, clinical pathologic, and electrophysiological results in AD and other pathological entities to put in a correct frame the value of Aβ changes. 相似文献