全文获取类型
收费全文 | 32892篇 |
免费 | 1666篇 |
国内免费 | 209篇 |
专业分类
耳鼻咽喉 | 360篇 |
儿科学 | 631篇 |
妇产科学 | 946篇 |
基础医学 | 3865篇 |
口腔科学 | 1571篇 |
临床医学 | 2515篇 |
内科学 | 8552篇 |
皮肤病学 | 486篇 |
神经病学 | 3077篇 |
特种医学 | 1287篇 |
外国民族医学 | 1篇 |
外科学 | 4771篇 |
综合类 | 143篇 |
一般理论 | 9篇 |
预防医学 | 1854篇 |
眼科学 | 655篇 |
药学 | 1810篇 |
中国医学 | 122篇 |
肿瘤学 | 2112篇 |
出版年
2023年 | 175篇 |
2022年 | 434篇 |
2021年 | 873篇 |
2020年 | 501篇 |
2019年 | 707篇 |
2018年 | 913篇 |
2017年 | 625篇 |
2016年 | 751篇 |
2015年 | 864篇 |
2014年 | 1197篇 |
2013年 | 1644篇 |
2012年 | 2477篇 |
2011年 | 2680篇 |
2010年 | 1549篇 |
2009年 | 1369篇 |
2008年 | 2335篇 |
2007年 | 2380篇 |
2006年 | 2264篇 |
2005年 | 2222篇 |
2004年 | 1970篇 |
2003年 | 1734篇 |
2002年 | 1615篇 |
2001年 | 256篇 |
2000年 | 200篇 |
1999年 | 237篇 |
1998年 | 269篇 |
1997年 | 219篇 |
1996年 | 201篇 |
1995年 | 174篇 |
1994年 | 152篇 |
1993年 | 112篇 |
1992年 | 130篇 |
1991年 | 122篇 |
1990年 | 102篇 |
1989年 | 104篇 |
1988年 | 97篇 |
1987年 | 81篇 |
1986年 | 80篇 |
1985年 | 77篇 |
1984年 | 113篇 |
1983年 | 82篇 |
1982年 | 100篇 |
1981年 | 61篇 |
1980年 | 46篇 |
1979年 | 40篇 |
1978年 | 47篇 |
1977年 | 46篇 |
1976年 | 31篇 |
1974年 | 39篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Michelle Moffa Ryan Cronk Donald Fejfar Sarah Dancausse Leslie Acosta Padilla Jamie Bartram 《International journal of hygiene and environmental health》2019,222(3):335-346
Background
There are well-established relationships between health and homelessness, and shelters can facilitate the transmission of diseases and contribute to their prevention. Adequate environmental health conditions and hygiene behaviors in homeless shelters are fundamental to the health of their clients, a marginalized population. We report the status of environmental health conditions and hygiene behaviors in homeless shelters and associated health outcomes; interventions to improve these conditions, behaviors, and outcomes; and obstacles to improvement.Methods
PubMed, Web of Science, Scopus, and EBSCOhost were searched for peer-reviewed studies, and additional sources for grey literature. Studies were included if they reported primary data on one or more environmental health condition or hygiene behavior in homeless shelters.Results
Twenty-eight studies were included in the review. Insufficient ventilation systems, unhygienic bedding, and overcrowding were the most documented environmental health and hygiene deficiencies in homeless shelters, and tuberculosis infections and skin diseases were the most documented associated health outcomes among clients. Studies frequently recommended or described implementation of behavioral and administrative controls, ventilation system improvements, and ultraviolet germicidal irradiation fixtures.Discussion
Most studies addressed airborne transmission of tuberculosis and were conducted in high-income countries, revealing an imbalance in the literature. Insufficient resources and the transience of clients are barriers to improving hygiene behaviors and environmental conditions in homeless shelters. Further investment and research into ensuring adequate hygiene and environmental health in this setting can protect and promote the health and well-being of people experiencing homelessness. 相似文献2.
3.
Angela Mauro Salvatore Mauro Roberto Rega Luigi Martemucci Rita Sottile 《Pediatric dermatology》2019,36(1):e34-e36
Henoch‐Schonlein purpura (HSP) is the most common systemic vasculitis in childhood. There is no consensus about the management for isolated cutaneous manifestations in HSP. We describe a case of HSP presenting with severe skin lesions that did not respond to standard therapy with corticosteroids. The 11‐year‐old child was treated with intravenous immunoglobulins, which induced rapid and persistent resolution of symptomatology. 相似文献
4.
A growing body of data suggests that therapies based on Toll-like receptors (TLR) targeting, in particular TLR4, holds promise in curing autoimmune and inflammatory pathologies still lacking specific treatment, included several rare diseases. While TLR4 activators (agonists) have already found successful clinical application as vaccine adjuvants, the use of TLR4 blockers (antagonists) as antisepsis agents or as agents against inflammatory diseases (including arthritis, multiple sclerosis, neuroinflammations) and cancer is still at a preclinical phase of development. This minireview focuses on recent achievements on the development of TLR4 modulators based on lipid A structure simplification, in particular on compounds having disaccharide or monosaccharide structures. As the TLR4 activity of natural TLR4 ligands (lipopolysaccharide, LPS and its biologically active part, the lipid A) depends on both the structure of endotoxin aggregates in solution and on single-molecule interaction with MD-2 and CD14 receptors, the rational design of TLR4 modulators should in principle take into account both these factors. In the light of the most recent advances in the field, in this minireview we discuss the structure–activity relationship in simplified lipid A analogs, with cationic or anionic amphiphilic structures. 相似文献
5.
6.
7.
Melatonin reduces oxidative stress and improves vascular function in pulmonary hypertensive newborn sheep 下载免费PDF全文
Flavio Torres Alejandro González‐Candia Camilo Montt Germán Ebensperger Magdalena Chubretovic María Serón‐Ferré Roberto V. Reyes Aníbal J. Llanos Emilio A. Herrera 《Journal of pineal research》2015,58(3):362-373
Pulmonary hypertension of the newborn (PHN) constitutes a critical condition with severe cardiovascular and neurological consequences. One of its main causes is hypoxia during gestation, and thus, it is a public health concern in populations living above 2500 m. Although some mechanisms are recognized, the pathophysiological facts that lead to PHN are not fully understood, which explains the lack of an effective treatment. Oxidative stress is one of the proposed mechanisms inducing pulmonary vascular dysfunction and PHN. Therefore, we assessed whether melatonin, a potent antioxidant, improves pulmonary vascular function. Twelve newborn sheep were gestated, born, and raised at 3600 meters. At 3 days old, lambs were catheterized and daily cardiovascular measurements were recorded. Lambs were divided into two groups, one received daily vehicle as control and another received daily melatonin (1 mg/kg/d), for 8 days. At 11 days old, lung tissue and small pulmonary arteries (SPA) were collected. Melatonin decreased pulmonary pressure and resistance for the first 3 days of treatment. Further, melatonin significantly improved the vasodilator function of SPA, enhancing the endothelial‐ and muscular‐dependent pathways. This was associated with an enhanced nitric oxide‐dependent and nitric oxide independent vasodilator components and with increased nitric oxide bioavailability in lung tissue. Further, melatonin reduced the pulmonary oxidative stress markers and increased enzymatic and nonenzymatic antioxidant capacity. Finally, these effects were associated with an increase of lumen diameter and a mild decrease in the wall of the pulmonary arteries. These outcomes support the use of melatonin as an adjuvant in the treatment for PHN. 相似文献
8.
9.
10.
Phenotypic and genetic features of enteropathogenic Escherichia coli isolates from diarrheal children in the Ribeirão Preto metropolitan area,São Paulo State,Brazil 下载免费PDF全文
André Pitondo‐Silva Gerson Nakazato Juliana P. Falcão Kinue Irino Roberto Martinez Ana Lúcia C. Darini Rodrigo Tavanelli Hernandes 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(2):128-135
This study was designed to characterize a collection of 60 enteropathogenic Escherichia coli (EPEC) isolates from diarrheic feces of patients in the Ribeirão Preto metropolitan area regarding different phenotypic and molecular features. We examined antibiotic resistance profiles, occurrence of virulence factors‐encoding genes, intimin subtypes and the correlation of serotypes among typical (tEPEC) and atypical (aEPEC) EPEC isolates. The results demonstrated that atypical EPEC was more heterogeneous than typical EPEC concerning the characteristics investigated and 45.2% do not belong to classical EPEC serogroups. Intimin subtype β was the most frequent among the EPEC isolates (46.7%), being detected in both tEPEC and aEPEC. The majority of aEPEC isolates presented localized adherence‐like (LAL) pattern to HEp‐2 cells, although aEPEC isolates displaying diffuse adherence (DA) or non‐adherent were also detected. High prevalence of antimicrobial resistance was found for ampicillin, cephalothin, sulfonamide and tetracycline. In general, tEPEC isolates were more resistant to the antimicrobials tested than aEPEC isolates. 相似文献