全文获取类型
收费全文 | 5190篇 |
免费 | 426篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 240篇 |
妇产科学 | 145篇 |
基础医学 | 785篇 |
口腔科学 | 84篇 |
临床医学 | 749篇 |
内科学 | 836篇 |
皮肤病学 | 58篇 |
神经病学 | 446篇 |
特种医学 | 261篇 |
外科学 | 725篇 |
综合类 | 174篇 |
一般理论 | 6篇 |
预防医学 | 508篇 |
眼科学 | 50篇 |
药学 | 289篇 |
中国医学 | 5篇 |
肿瘤学 | 268篇 |
出版年
2023年 | 41篇 |
2022年 | 51篇 |
2021年 | 158篇 |
2020年 | 83篇 |
2019年 | 131篇 |
2018年 | 154篇 |
2017年 | 108篇 |
2016年 | 132篇 |
2015年 | 127篇 |
2014年 | 166篇 |
2013年 | 219篇 |
2012年 | 299篇 |
2011年 | 394篇 |
2010年 | 175篇 |
2009年 | 152篇 |
2008年 | 227篇 |
2007年 | 253篇 |
2006年 | 234篇 |
2005年 | 249篇 |
2004年 | 200篇 |
2003年 | 178篇 |
2002年 | 169篇 |
2001年 | 108篇 |
2000年 | 109篇 |
1999年 | 116篇 |
1998年 | 88篇 |
1997年 | 70篇 |
1996年 | 73篇 |
1995年 | 47篇 |
1994年 | 51篇 |
1993年 | 42篇 |
1992年 | 67篇 |
1991年 | 77篇 |
1990年 | 64篇 |
1989年 | 60篇 |
1988年 | 86篇 |
1987年 | 43篇 |
1986年 | 58篇 |
1985年 | 47篇 |
1984年 | 57篇 |
1983年 | 50篇 |
1982年 | 49篇 |
1981年 | 31篇 |
1980年 | 30篇 |
1979年 | 34篇 |
1978年 | 24篇 |
1974年 | 28篇 |
1973年 | 34篇 |
1972年 | 20篇 |
1967年 | 23篇 |
排序方式: 共有5650条查询结果,搜索用时 15 毫秒
111.
J. L. Casey D. J. King R. B. Pedley J. A. Boden R. Boden L. C. Chaplin M. Dorning R. H. Begent 《British journal of cancer》1998,78(10):1307-1312
Radioimmunotherapy (RIT) is currently limited by toxicity to normal tissues as a result of prolonged circulating radioantibody in the blood. In this study, the use of a clearing antibody was investigated (second antibody) in an attempt to reduce blood background levels of [90Y]A5B7 immunoglobulin G (IgG) activity, and, therefore, improve the therapeutic tumour-blood ratio in nude mice bearing human colorectal tumour xenografts. The second antibody was raised against the 12N4 macrocycle group used for chelation of 90Y, and is, thus, applicable to any anti-tumour antibody labelled with this methodology. Second antibody was administered 18, 24 or 48 h after radiolabelled antibody injection and produced up to a tenfold reduction in blood levels and a tenfold improvement in tumour-blood ratios. This has the advantage of reducing the risk of myelotoxicity caused by prolonged retention of activity in the blood. For all normal tissues, there was a similar or slightly lower uptake of [90Y]IgG with second antibody clearance, apart from a transient rise in liver activity due to complexes of primary and secondary antibody clearing via the liver. As a result of clearance of [90Y]IgG from the blood pool, there was an associated fall in the amount of antibody at the tumour site (up to 3.3-fold) at later time points for mice injected with second antibody. However, despite this, tumour-blood ratios remained superior to the control group at these later time points. Estimated dosimetry evaluation revealed that total dose to normal tissues, blood and tumour was lower than for the non-clearance group. Surprisingly, however, there was little improvement in total estimated tumour-blood dose ratio over the time period studied. This was probably because the majority of the dose was delivered to both the blood and tumour within the first 24 h after administration of [90Y]IgG, so that giving the clearing agent after this time did not produce a large difference in total estimated dose. The anti-macrocycle second antibody proved to be a successful clearing agent and could potentially be applied to any anti-tumour antibody coupled with the 12N4 macrocycle. In the light of the estimated dosimetry results described here, it would probably be most useful given at earlier time points (i.e. before 18 h after injection of primary antibody) to produce an improved tumour-blood ratio of total dose. Development of this strategy may allow higher levels of activity to be administered for RIT, and repeated dosing regimens. 相似文献
112.
Torrance G.W. Keresteci M.A. Casey R.W. Rosner A.J. Ryan N. Breton M.C. 《Quality of life research》2004,13(2):349-359
Health-related quality of life instruments may be generic or specific. In general, only generic instruments use preference-based scoring. We report on a novel approach to combine in one instrument the strengths of the specific approach, greater disease relevance and responsiveness, with those of preference-based scoring, generalizability through utilities. OBJECTIVES: The primary objective was to develop a self-administered, preference-based instrument capable of measuring utilities in the disease-specific context of erectile dysfunction (ED). METHODS: Content derivation/validation began with a literature review. Eight attributes (domains) were selected to provide clinical experts structure for focus group discussion. Four levels describing a continuum of dysfunction-function were defined for each domain. Each domain, including functional levels, was reviewed and modified until consensus was achieved regarding content. This content was then integrated into a preference based scoring instrument using two visual analogue scales (VAS) with which patients rated three 'marker' health states (representing mild, moderate and severe ED), their self-state and a previously validated external marker state. The instrument was pilot tested, and implemented in a clinical trial. Initial validation analyses have been performed. RESULTS: A self-administered, preference-based, VAS instrument was developed for use in the ED population, and the instrument was feasible to complete, was reliable beyond the threshold of acceptability established a priori and demonstrated good validity. Evidence of these properties accumulates over time and this study begins that process with this instrument. Responsiveness is being assessed in the context of a clinical trial. 相似文献
113.
Hirsch GM Casey PJ Raza-Ahmad A Miller RM Hirsch KJ 《The Annals of thoracic surgery》2000,69(2):611-613
Giant coronary artery aneurysms are rare in adults and are usually found in association with Kawasaki's disease arising in childhood. We report a case of a thrombosed giant right coronary artery aneurysm presenting as an intracardiac mass detected after inferior wall myocardial infarction. Histologic analysis indicated that fibromuscular dysplasia was the underlying cause of the aneurysm. 相似文献
114.
Mine S Cicek Xin Liu Graham Casey John S Witte 《Cancer epidemiology, biomarkers & prevention》2005,14(9):2173-2177
Candidate genes involved with androgen metabolism have been hypothesized to affect the risk of prostate cancer. To further investigate this, we evaluated the relationship between prostate cancer and multiple potentially functional polymorphisms in three genes involved in androgen metabolism: CYP1B1 (two single nucleotide polymorphisms: 355G/T and 4326C/G), prostate-specific antigen (PSA/KLK3 (three single nucleotide polymorphisms: -158A/G, -4643G/A, and -5412C/T), and CYP11alpha [(tttta)(n) repeat], using a moderately large (n = 918) sibling-based case-control population. When looking at all subjects combined, no association was observed between any polymorphism-or their haplotypes-and prostate cancer risk. However, among men with more aggressive prostate cancer, the CYP1B1 355G/T variant was positively associated with disease: carrying one or two T alleles gave odds ratios (OR) of 1.90 [95% confidence interval (95% CI), 1.09-3.31; P = 0.02] and 3.73 (95% CI, 1.39-10.0; P = 0.009), respectively. Similarly, carrying the CYP1B1 355T-4326C haplotype was positively associated with prostate cancer among men with high aggressive disease (P = 0.01). In addition, the PSA -158G/-158G genotype was positively associated with prostate cancer among men with less aggressive disease (OR, 2.71; 95% CI, 1.06-6.94; P = 0.04). Our findings suggest that CYP1B1 and PSA variants may affect the risk of prostate cancer and tumor aggressiveness. 相似文献
115.
Using action research to develop midwives’ skills to support women with perinatal mental health needs 下载免费PDF全文
116.
Requests for removal of unwanted body hair are common in dermatologic and surgical practices. Technology continues to improve the achievement of a more permanent reduction through the use of lasers. Despite the increased use of lasers, to date, few guidelines exist in terms of how to approach laser hair removal. Specifically, one must understand the mechanism of hair growth and how lasers work to target the hair follicle. There is significant variation among practitioners in pre‐and post‐laser recommendations to patients as well as intervals between treatment sessions. We performed a thorough review of the literature in order to determine evidence for the ideal interval between treatment sessions and the ideal number of sessions. We also sought to establish, based on published reports, the recommendations for shaving, plucking, waxing or other hair removal methods prior to laser hair removal and the guidelines for sun exposure before and after laser treatments. Finally, we searched the literature to find out whether there are areas that should not be treated with laser hair removal. The evidence and recommendations in this article aim to help guide practitioners in their approach to laser hair removal. 相似文献
117.
118.
Jae Hyun Kim Casey N Ta Cong Liu Cynthia Sung Alex M Butler Latoya A Stewart Lyudmila Ena James R Rogers Junghwan Lee Anna Ostropolets Patrick B Ryan Hao Liu Shing M Lee Mitchell S V Elkind Chunhua Weng 《J Am Med Inform Assoc》2021,28(1):14
ObjectiveThis research aims to evaluate the impact of eligibility criteria on recruitment and observable clinical outcomes of COVID-19 clinical trials using electronic health record (EHR) data.Materials and MethodsOn June 18, 2020, we identified frequently used eligibility criteria from all the interventional COVID-19 trials in ClinicalTrials.gov (n = 288), including age, pregnancy, oxygen saturation, alanine/aspartate aminotransferase, platelets, and estimated glomerular filtration rate. We applied the frequently used criteria to the EHR data of COVID-19 patients in Columbia University Irving Medical Center (CUIMC) (March 2020–June 2020) and evaluated their impact on patient accrual and the occurrence of a composite endpoint of mechanical ventilation, tracheostomy, and in-hospital death.ResultsThere were 3251 patients diagnosed with COVID-19 from the CUIMC EHR included in the analysis. The median follow-up period was 10 days (interquartile range 4–28 days). The composite events occurred in 18.1% (n = 587) of the COVID-19 cohort during the follow-up. In a hypothetical trial with common eligibility criteria, 33.6% (690/2051) were eligible among patients with evaluable data and 22.2% (153/690) had the composite event.DiscussionBy adjusting the thresholds of common eligibility criteria based on the characteristics of COVID-19 patients, we could observe more composite events from fewer patients.ConclusionsThis research demonstrated the potential of using the EHR data of COVID-19 patients to inform the selection of eligibility criteria and their thresholds, supporting data-driven optimization of participant selection towards improved statistical power of COVID-19 trials. 相似文献
119.
Kimberly S. Bowles David W. Horohov Daniel B. Paulsen Casey J. LeBlanc Martha A. Littlefield-Chabaud Terry Ahlert 《Inhalation toxicology》2013,25(1):43-51
Epidemiologic evidence supports a role for environmental tobacco smoke (ETS) in the occurrence and severity of allergies/asthma. However, neither the precise combination of ETS and allergen exposure nor the mechanism (or mechanisms) by which these factors interact and contribute to asthma induction is known. Animal model studies have failed to establish a convincing relationship between ETS exposure and asthma induction, perhaps because of methodological inadequacies. Here, we tested the hypothesis that ETS inhalation would provoke an asthmatic response by overcoming normal airway tolerance to inhaled antigens. Our protocol combined daily ETS exposure with nose-only sensitization to ovalbumin. Three strains of mice were tested, each with a different level of susceptibility to airway hypersensitivity. Immunological responses were assessed by immunoglobulin production. Airway inflammation was assessed by bronchoalveolar lavage differentials and lung histopathology. Airway hyperresponsiveness was determined by methacholine challenge. The mice produced ovalbumin-specific antibodies following ovalbumin exposure in a strain-dependent manner. Only the A/J mice produced detectable levels of ovalbumin-specific immunoglobulin (Ig) E. Both A/J and BALB/c mice produced ovalbumin-specific IgG1 antibodies. The C57Bl/6 mice did not produce detectable levels of antibodies. The A/J mice also exhibited airway inflammation following ovalbumin exposure. Neither the C57Bl/6 nor the BALB/c mice exhibited signs of airway inflammation. Exposure to ETS failed to enhance ovalbumin-specific antibody production, airway inflammation, or hyperresponsiveness. Together these results indicate that ETS exposure accompanied by nose-only allergen sensitization fails to overcome aerosol tolerance in adult mice. 相似文献
120.