全文获取类型
收费全文 | 204850篇 |
免费 | 3545篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 1384篇 |
儿科学 | 7609篇 |
妇产科学 | 3798篇 |
基础医学 | 20293篇 |
口腔科学 | 1992篇 |
临床医学 | 16503篇 |
内科学 | 36196篇 |
皮肤病学 | 1083篇 |
神经病学 | 19075篇 |
特种医学 | 9577篇 |
外国民族医学 | 1篇 |
外科学 | 32912篇 |
综合类 | 2830篇 |
一般理论 | 61篇 |
预防医学 | 21584篇 |
眼科学 | 3177篇 |
药学 | 11354篇 |
1篇 | |
中国医学 | 659篇 |
肿瘤学 | 18369篇 |
出版年
2023年 | 319篇 |
2022年 | 409篇 |
2021年 | 1055篇 |
2020年 | 675篇 |
2019年 | 1066篇 |
2018年 | 22888篇 |
2017年 | 18073篇 |
2016年 | 20168篇 |
2015年 | 1837篇 |
2014年 | 2056篇 |
2013年 | 2488篇 |
2012年 | 9372篇 |
2011年 | 23306篇 |
2010年 | 20032篇 |
2009年 | 12563篇 |
2008年 | 21278篇 |
2007年 | 23534篇 |
2006年 | 2254篇 |
2005年 | 3816篇 |
2004年 | 4854篇 |
2003年 | 5638篇 |
2002年 | 3679篇 |
2001年 | 593篇 |
2000年 | 675篇 |
1999年 | 446篇 |
1998年 | 469篇 |
1997年 | 430篇 |
1996年 | 267篇 |
1995年 | 237篇 |
1994年 | 220篇 |
1993年 | 168篇 |
1992年 | 241篇 |
1991年 | 282篇 |
1990年 | 294篇 |
1989年 | 212篇 |
1988年 | 190篇 |
1987年 | 154篇 |
1986年 | 166篇 |
1985年 | 160篇 |
1984年 | 124篇 |
1983年 | 110篇 |
1982年 | 90篇 |
1980年 | 89篇 |
1979年 | 89篇 |
1978年 | 87篇 |
1974年 | 77篇 |
1973年 | 72篇 |
1972年 | 71篇 |
1968年 | 63篇 |
1932年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
1.
2.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses... 相似文献
3.
4.
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5.
Cameron Duff 《Addiction (Abingdon, England)》2020,115(7):1378-1381
In 1998 Howard Parker, Judith Aldridge & Fiona Measham published Illegal Leisure, a ground‐breaking study of profound changes in British youth cultures in the 1990s, and the place of drugs and drug use in these upheavals. This work introduced the ‘normalization thesis’ to the social sciences, offering a novel vocabulary for re‐imagining the normative character of young people's attitudes towards and experiences of illicit drug use. Arriving at the dawn of the new century, the book offered a thoroughgoing re‐thinking of the character of youth cultures at a time of great social, cultural, economic and technological disruption. In so doing, the book deftly anticipated many of the most interesting currents of critical drug studies that followed. 相似文献
6.
Christopher D Hue Frances S Cho Siqi Cao Cameron R ”Dale” Bass David F Meaney Barclay Morrison III 《Journal of cerebral blood flow and metabolism》2015,35(7):1191-1198
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α− isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury. 相似文献
7.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
8.
9.