全文获取类型
收费全文 | 26343篇 |
免费 | 1295篇 |
国内免费 | 251篇 |
专业分类
耳鼻咽喉 | 213篇 |
儿科学 | 513篇 |
妇产科学 | 620篇 |
基础医学 | 2771篇 |
口腔科学 | 523篇 |
临床医学 | 2284篇 |
内科学 | 7684篇 |
皮肤病学 | 565篇 |
神经病学 | 2314篇 |
特种医学 | 916篇 |
外科学 | 4301篇 |
综合类 | 62篇 |
一般理论 | 5篇 |
预防医学 | 951篇 |
眼科学 | 346篇 |
药学 | 1375篇 |
中国医学 | 43篇 |
肿瘤学 | 2403篇 |
出版年
2024年 | 32篇 |
2023年 | 224篇 |
2022年 | 461篇 |
2021年 | 773篇 |
2020年 | 487篇 |
2019年 | 641篇 |
2018年 | 765篇 |
2017年 | 586篇 |
2016年 | 722篇 |
2015年 | 784篇 |
2014年 | 998篇 |
2013年 | 1372篇 |
2012年 | 2119篇 |
2011年 | 2078篇 |
2010年 | 1220篇 |
2009年 | 1093篇 |
2008年 | 1906篇 |
2007年 | 1803篇 |
2006年 | 1648篇 |
2005年 | 1659篇 |
2004年 | 1519篇 |
2003年 | 1344篇 |
2002年 | 1241篇 |
2001年 | 159篇 |
2000年 | 110篇 |
1999年 | 160篇 |
1998年 | 219篇 |
1997年 | 200篇 |
1996年 | 154篇 |
1995年 | 183篇 |
1994年 | 149篇 |
1993年 | 139篇 |
1992年 | 87篇 |
1991年 | 74篇 |
1990年 | 87篇 |
1989年 | 52篇 |
1988年 | 46篇 |
1987年 | 38篇 |
1986年 | 49篇 |
1985年 | 51篇 |
1984年 | 56篇 |
1983年 | 41篇 |
1982年 | 53篇 |
1981年 | 32篇 |
1980年 | 43篇 |
1979年 | 25篇 |
1978年 | 15篇 |
1977年 | 17篇 |
1975年 | 19篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Molecular and Cellular Analysis of Human T Lymphocytes Expressing γδ T-Cell Receptor 总被引:1,自引:0,他引:1
72.
Cornaglia G 《Le infezioni in medicina : rivista periodica di eziologia, epidemiologia, diagnostica, clinica e terapia delle patologie infettive》2002,10(2):61-72
The cephalosporins today, and particularly the third-generation cephalosporins, still possess an activity spectrum and microbiological potency such that several authors continue to regard them as the gold standard of beta-lactam antibiotic therapy. Comparison with the rapid onset of resistance to other extensively used drugs, such as the macrolides and quinolones, places the emphasis once again squarely on the great reliability of the antibacterial action of the cephalosporins and, particularly, on the validity of their targets at the bacterial cell level. The beneficial use of cephalosporins for a vast range of infectious diseases is amply confirmed by the most authoritative international guidelines and bears witness to the role of great importance that these drugs still play in all fields of antibiotic therapy, as a result of the variety of the compounds available, their broad spectrum of antibacterial activity, their multiple clinical potentialities and their excellent tolerability. The cephalosporins therefore continue to constitute a firm reference point in the overcrowded antibiotics scene and, if used appropriately, promise to conserve their leading role for a long time to come. 相似文献
73.
74.
ABSTRACT Renal agenesis (RA) appears to be a multifactorial condition with combined genetic and environmental influences. We performed a retrospective case-control study of reproductive history of 26 isolated RA live births cases referred to Sicilian Registry of Congenital Malformations. A statistical significant association for birth weight if we considered all RA together and for bilateral RA alone, an increasing risk for maternal age only in the bilateral RA subgroup and a male predominance both for unilateral and bilateral RA was found. Our results show that some reproductive risk factors may be associated with RA, moreover differences found between subgroups indicate that some risk factors may be different in unilateral and bilateral RA. The association between reproductive risk factors and RA may reflect pathogenetic interaction between genetic and environmental factors. Nevertheless further studies are needed to clarify these associations and to explore the role of perinatal factors in the etiology of renal agenesis. In fact if prenatal or perinatal risk factors are in a causal chain influencing the risk for developing RA, then these data could have important implications in the prevention or treatment of this condition. 相似文献
75.
Ivo Giovannini M.D. Giuseppe Boldrini M.D. Carlo Chiarla M.D. Marco Castagneto M.D. Gabriele Sganga M.D. Giuseppe Tramutola M.D. Francesco Caracciolo M.D. Giancarlo Castiglioni M.D. F.A.C.S. 《World journal of surgery》1987,11(2):202-209
The cirrhotic condition is characterized by a series of changes in physiological functions and of subclinical alterations that imply an abnormal and fragile adaptive pattern with reduced resistance to superimposed distress. In the care of the critically ill cirrhotic patient, the supportive measures aimed at maintaining physiological stability through the control of such debilitating factors have a key role and are not secondary in importance to the more obvious measures needed to treat clinically evident and specific alterations or complications. The relationship between hepatic malfunction and the development of these physiological abnormalities is not fully understood. Our knowledge of the problem, however, has been recently improved and the need for supportive measures motivated by a series of notions on cardiorespiratory and metabolic abnormalities and interactions in hepatic decompensation.
Resumen La condición cirrótica se caracteriza por una serie de cambios en las funciones fisiológicas y por alteraciones subclinicas que implican un patrón de adaptación anormal y fragil de resistencia reducida al estrés. Estas incluyen disfunción respiratoria con tendencia a la hipoxemia arterial en presencia de elevados indices cardiacos, una situatión crónica de hiperdinamismo cardiovascular pero con precaria eficacia miocárdica y latente riesgo de falla de alto débito, y cambios metabólicos que se traducen en un estado de fallas multisistémicas interrelacionadas características del cirrótico. En el cuidado del paciente cirrótico en estado crítico, las medidas de soporte orientadas al mantenimiento de la estabilidad fisiológica mediante el control de tales factores debilitantes tienen una importancia capital y no son secundarias frente a aquellas muy obvias que se requieren para tratar alteraciones o complicaciones específicas y clínicamente evidentes. La relación entre la disfunción hepática y el desarrollo de las mencionadas anormalidades fisiológicas no está totalmente aclarada, sin embargo, el estado de nuestro conocimiento sobre el problema ha sido enriquecido recientemente y se ha fortalecido la necesidad de establecer medidas de soporte por una serie de nociones relativas a las anormalidades e interacciones cardiorrespiratorias y metabólicas de la descompensación hepática.
Résumé La cirrhose est caractérisée par des séries de variations des fonctions physiologiques et de modifications cliniques qui impliquent des modalités d'adaptation anormale et fragile se traduisant par une résistance réduite à l'état de détresse ou peut se trouver le cirrhotique. Des mesures appropriées pour maintenir la stabilité physiologique ont un rôle principal en présence de ces facteurs défavorables. Elles ne doivent pas être considérées comme moins importantes que les mesures essentielles qui sont nécessaires pour traiter les complications et les modifications cliniques spécifiques. La relation entre l'altération des fonctions du foie et le développement des anomalies physiologiques précitées n'est pas parfaitement élucidée, cependant, nos connaissances de ce problème ont été récemment améliorées et le besoin de mesures adéquates de soutien est devenu manifeste en raison de séries acquises de notions concernant les anomalies cardio-respiratoires et métaboliques ainsi que les interactions de la décompensation hépatique.相似文献
76.
Giuseppe Giuffrè 《Documenta ophthalmologica. Advances in ophthalmology》1987,64(2):187-199
In a study of 15 eyes with optic pits fluorescein angiography revealed that only pits associated with serous detachment of the macular retina showed fluorescence in the late venous phase, while the pits uncomplicated by detachment remained hypofluorescent throughout the test. This finding strongly supports the hypothesis that the subretinal fluid producing the macular detachment originates from leakage of vessels located in the floor of the pit. In addition a high incidence of anomalies was found to be associated with optic pits. Therefore the author suggests to call the association between optic pit and large optic disc, parapapillary chorioretinal changes, cilioretinal vessels, situs inversus and eventual other vessel abnormalities, the optic pit syndrome. 相似文献
77.
A new metabolite of the diuretic drug bumetanide, the 4-[(4-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment. 相似文献
78.
Salvatore Corrao Raffaella Mallaci Bocchio Marika Lo Monaco Giuseppe Natoli Attilio Cavezzi Emidio Troiani Christiano Argano 《Nutrients》2021,13(4)
More than one year has passed since the first cases of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome (SARS)-CoV-2 coronavirus were reported in Wuhan (China), rapidly evolving into a global pandemic. This infectious disease has become a major public health challenge in the world. Unfortunately, to date, no specific antivirals have been proven to be effective against COVID-19, and although a few vaccines are available, the mortality rate is not decreasing but is still increasing. One therapeutic strategy has been focused on infection prevention and control measures. In this regard, the use of nutraceutical supports may play a role against some aspect of the infection, particularly the inflammatory state and the immune system function of patients, thus representing a strategy to control the worst outcomes of this pandemic. For this reason, we performed an overview including meta-analyses and systematic reviews to assess the association among melatonin, vitamin C, vitamin D, zinc supplementation and inflammatory markers using three databases, namely, MEDLINE, PubMed Central and the Cochrane Library of Systematic Reviews. According to the evidence available, an intake of 50,000 IU/month of vitamin D showed efficacy in CRP. An amount of 1 to 2 g per day of vitamin C demonstrated efficacy both in CRP and endothelial function, and a dosage of melatonin ranging from 5 to 25 mg /day showed good evidence of efficacy in CRP, TNF and IL6. A dose of 50 mg/day of elemental zinc supplementation showed positive results in CRP. Based on the data reported in this review, the public health system could consider whether it is possible to supplement the current limited preventive measures through targeted nutraceutical large-scale administration. 相似文献
79.
Vincenzo Di Stefano Raffaele Ornello Andrea Gagliardo Angelo Torrente Elisa Illuminato Valeria Caponnetto Ilaria Frattale Raffaella Golini Chiara Di Felice Fabiola Graziano Maria Caccamo Davide Ventimiglia Salvatore Iacono Gabriella Matarazzo Francesco Armetta Giuseppe Battaglia Alberto Firenze Simona Sacco Filippo Brighina 《Nutrients》2021,13(4)
Background: The restrictions taken to control the rapid spread of COVID-19 resulted in a sudden, unprecedented change in people’s lifestyle, leading to negative consequences on general health. This study aimed to estimate the impact of such changes on migraine severity during 2020 March–May lockdown. Methods: Patients affected by migraine with or without aura, diagnosed by expert physicians, completed a detailed interview comprehensive of: assessment of migraine characteristics; measure of physical activity (PA) levels; measure of the intake frequency of main Italian foods; the Insomnia Severity Index (ISI) questionnaire investigating sleep disorders. Results: We included 261 patients with a mean age of 44.5 ± 12.3 years. During social distancing, 72 patients (28%) reported a headache worsening, 86 (33%) an improvement, and 103 (39%) a stable headache frequency. A significant decrease of the PA levels during COVID-19 quarantine in the whole study sample was observed (median total metabolic equivalent task (METs) decreased from 1170 to 510; p < 0.001). Additionally, a significant difference was reported on median ISI scores (from 7 to 8; p < 0.001), which were increased in patients who presented a stable or worsening headache. Conclusions: Our study confirmed that the restrictions taken during the pandemic have affected the practice of PA levels and sleep quality in migraine. Hence, PA and sleep quality should be assessed to find strategies for an improvement in quality of life. 相似文献
80.
Ostinelli Edoardo G. D’Agostino Armando Pesce Luisa Zangani Caroline Miragoli Paolo Durbano Federico Biffi Giuseppe Mencacci Claudio Scarone Silvio Gambini Orsola 《Zeitschrift fur Gesundheitswissenschaften》2021,29(6):1343-1355
Journal of Public Health - Neighbourhood composition is considered a social determinant of mental health that can be addressed by policymakers to improve outcomes. Deprived neighbourhoods typically... 相似文献