全文获取类型
收费全文 | 34195篇 |
免费 | 2787篇 |
国内免费 | 112篇 |
专业分类
耳鼻咽喉 | 443篇 |
儿科学 | 953篇 |
妇产科学 | 625篇 |
基础医学 | 4425篇 |
口腔科学 | 805篇 |
临床医学 | 3556篇 |
内科学 | 6824篇 |
皮肤病学 | 357篇 |
神经病学 | 3536篇 |
特种医学 | 1427篇 |
外科学 | 4950篇 |
综合类 | 656篇 |
一般理论 | 21篇 |
预防医学 | 3372篇 |
眼科学 | 1083篇 |
药学 | 2244篇 |
中国医学 | 61篇 |
肿瘤学 | 1756篇 |
出版年
2021年 | 351篇 |
2020年 | 262篇 |
2019年 | 379篇 |
2018年 | 418篇 |
2017年 | 329篇 |
2016年 | 397篇 |
2015年 | 517篇 |
2014年 | 824篇 |
2013年 | 1397篇 |
2012年 | 1826篇 |
2011年 | 2035篇 |
2010年 | 1127篇 |
2009年 | 1066篇 |
2008年 | 1929篇 |
2007年 | 2151篇 |
2006年 | 2171篇 |
2005年 | 2189篇 |
2004年 | 2068篇 |
2003年 | 2063篇 |
2002年 | 2116篇 |
2001年 | 443篇 |
2000年 | 368篇 |
1999年 | 462篇 |
1998年 | 485篇 |
1997年 | 399篇 |
1996年 | 379篇 |
1995年 | 353篇 |
1994年 | 335篇 |
1993年 | 330篇 |
1992年 | 307篇 |
1991年 | 286篇 |
1990年 | 276篇 |
1989年 | 297篇 |
1988年 | 289篇 |
1987年 | 282篇 |
1986年 | 283篇 |
1985年 | 296篇 |
1984年 | 354篇 |
1983年 | 353篇 |
1982年 | 464篇 |
1981年 | 444篇 |
1980年 | 437篇 |
1979年 | 264篇 |
1978年 | 263篇 |
1977年 | 269篇 |
1976年 | 212篇 |
1975年 | 208篇 |
1974年 | 224篇 |
1973年 | 224篇 |
1972年 | 186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.
O. Morris M. Fairclough J. Grigg C. Prenant A. McMahon 《Journal of labelled compounds & radiopharmaceuticals》2019,62(1):4-23
Affinity peptide and protein‐ (APP) based radiotracers are an increasingly popular class of radiotracer in positron emission tomography (PET), which was once dominated by the use of small molecule radiotracers. Radiolabelled monoclonal antibodies (mAbs) are important examples of APPs, yet a preference for smaller APPs, which exhibit fast pharmacokinetics and permit rapid PET aided diagnosis, has become apparent. 18F exhibits favourable physical characteristics for APP radiolabelling and has been described as an ideal PET radionuclide. Notwithstanding, 18F radiolabelling of APP is challenging, and this is echoed in the literature where a number of diverse approaches have been adopted. This review seeks to assess and compare the approaches taken to 18F APP radiolabelling with the intention of highlighting trends within this expanding field. Generic themes have emerged in the literature, namely the use of mild radiolabelling conditions, a preference of site‐specific methodologies with an impetus for short, automated procedures which produce high‐yielding [18F]APPs. 相似文献
4.
5.
James I. Geller MD Joseph G. Pressey MD Malcolm A. Smith MD Rachel A. Kudgus PhD Mariana Cajaiba MD Joel M. Reid PhD David Hall PhD Donald A. Barkauskas PhD Stephen D. Voss MD Steve Y. Cho MD Stacey L. Berg MD Jeffrey S. Dome MD PhD Elizabeth Fox MD Brenda J. Weigel MD 《Cancer》2020,126(24):5303-5310
6.
Amy Y. Zhang Christopher Burant Alex Z. Fu Gerald Strauss Donald R. Bodner Lee Ponsky 《Journal of psychosocial oncology》2020,38(2):210-227
AbstractPurpose: We examined underlying psychosocial processes of a behavioral treatment for urinary incontinence (UI) of prostate cancer survivors.Design: Secondary analysis of data collected from a clinical trial.Sample: Two hundred forty-four prostate cancer survivors who participated in a clinical trial of behavioral intervention to UI as intervention or control subjects.Methods: The participants had a 3-month behavioral intervention or usual care and were followed up for an additional 3?months. They were assessed at baseline, 3, and 6?months. Latent growth curve models were performed to examine trajectories of each study variable and relationships among the variables.Findings: Increasing self-efficacy and social support were significantly and independently associated with more reduction of urinary leakage frequency over time.Implications for psychosocial oncology: Providing problem-solving skills and social support, including peer support, are essential for empowering patients to reduce UI. 相似文献
7.
8.
Marlene L Hauck Susan M LaRue William P Petros Jean M Poulson Daohai Yu Ivan Spasojevic Amy F Pruitt Allison Klein Beth Case Donald E Thrall David Needham Mark W Dewhirst 《Clinical cancer research》2006,12(13):4004-4010
PURPOSE: To determine the maximum tolerated dose, dose-limiting toxicities, and pharmacokinetic characteristics of doxorubicin encapsulated in a low temperature sensitive liposome (LTSL) when given concurrently with local hyperthermia to canine solid tumors. EXPERIMENTAL DESIGN: Privately owned dogs with solid tumors (carcinomas or sarcomas) were treated. The tumors did not involve bone and were located at sites amenable to local hyperthermia. LTSL-doxorubicin was given (0.7-1.0 mg/kg i.v.) over 30 minutes during local tumor hyperthermia in a standard phase I dose escalation study. Three treatments, given 3 weeks apart, were scheduled. Toxicity was monitored for an additional month. Pharmacokinetics were evaluated during the first treatment cycle. RESULTS: Twenty-one patients were enrolled: 18 with sarcomas and 3 with carcinomas. Grade 4 neutropenia and acute death secondary to liver failure, possibly drug related, were the dose-limiting toxicities. The maximum tolerated dose was 0.93 mg/kg. Other toxicities, with the possible exception of renal damage, were consistent with those observed following free doxorubicin administration. Of the 20 dogs that received > or = 2 doses of LTSL-doxorubicin, 12 had stable disease, and 6 had a partial response to treatment. Pharmacokinetic variables were more similar to those of free doxorubicin than the marketed liposomal product. Tumor drug concentrations at a dose of 1.0 mg/kg averaged 9.12 +/- 6.17 ng/mg tissue. CONCLUSION: LTSL-doxorubicin offers a novel approach to improving drug delivery to solid tumors. It was well tolerated and resulted in favorable response profiles in these patients. Additional evaluation in human patients is warranted. 相似文献
9.
B Sedgmen C McMahon D Cairns R J Benzie R L Woodfield 《Ultrasound in obstetrics & gynecology》2006,27(3):245-251
OBJECTIVE: To explore the impact of timing and type of ultrasound, particularly three-dimensional (3D), exposure on maternal-fetal attachment and maternal health behavior during pregnancy. METHODS: Subjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal-fetal attachment and health behavior, and were then allocated arbitrarily to either two-dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later. RESULTS: Maternal-fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus. CONCLUSIONS: Ultrasound has a positive impact on maternal-fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure. 相似文献
10.