全文获取类型
收费全文 | 1120篇 |
免费 | 66篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 15篇 |
妇产科学 | 19篇 |
基础医学 | 100篇 |
口腔科学 | 126篇 |
临床医学 | 62篇 |
内科学 | 285篇 |
皮肤病学 | 4篇 |
神经病学 | 97篇 |
特种医学 | 44篇 |
外科学 | 147篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 80篇 |
眼科学 | 30篇 |
药学 | 123篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 26篇 |
2020年 | 28篇 |
2019年 | 19篇 |
2018年 | 20篇 |
2017年 | 21篇 |
2016年 | 26篇 |
2015年 | 20篇 |
2014年 | 32篇 |
2013年 | 55篇 |
2012年 | 80篇 |
2011年 | 64篇 |
2010年 | 58篇 |
2009年 | 54篇 |
2008年 | 89篇 |
2007年 | 77篇 |
2006年 | 73篇 |
2005年 | 57篇 |
2004年 | 61篇 |
2003年 | 64篇 |
2002年 | 55篇 |
2001年 | 18篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 22篇 |
1991年 | 15篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 5篇 |
1965年 | 1篇 |
排序方式: 共有1188条查询结果,搜索用时 0 毫秒
61.
Michelson J Moskovitz P Labropoulos P 《Foot & ankle international / American Orthopaedic Foot and Ankle Society [and] Swiss Foot and Ankle Society》2004,25(3):149-150
Although most of the controversy surrounding the treatment of intra-articular, vertical impact fractures of the lower tibia is due to the difficult clinical problems they pose, there is a minor, ongoing dispute regarding nomenclature. In the last several decades, these fractures have been called either pilon or pylon fractures. This study traces the etymology of both terms and relates them to their usage in the orthopaedic literature. Based on the origins of each word, and how they were introduced into the orthopaedic literature, it is concluded that the correct term for an intra-articular, vertical impact fracture of the lower tibia is pilon fracture. 相似文献
62.
Tischler V Karim K Rustall S Gregory P Vostanis P 《Health & social care in the community》2004,12(4):327-335
The objective of the present study was to establish the psychosocial characteristics and perspectives of 49 consecutive homeless families who received input from a new designated family support worker (FSW) post at a large statutory hostel for homeless parents and children. The FSW provided: assessment of social, educational and health needs; support and parent training; and liaison with and referral to specialist services. Measures included quantitative questionnaires (i.e. the Hospital Anxiety and Depression Scale, the Parenting Daily Hassles Scale, the Eyberg Child Behaviour Inventory, and the Health of the Nation Outcome Scales for Children and Adolescents), and a qualitative (semistructured) interview on service experiences and satisfaction. The psychosocial measures indicated high rates of parenting difficulties, mental health and related needs among children and their parents. Parenting difficulties were associated with child behaviour problems. Parents expressed satisfaction with the service whilst they were residents at the hostel, but they were often not clear about the objectives of agencies and interventions. Family support interventions have a key role in service provision for homeless and other vulnerable families by providing direct parenting interventions and ensuring that specialist agencies are appropriately involved. Family support worker involvement needs to continue when families are re-housed in the community. 相似文献
63.
64.
PURPOSE: i) To develop novel approaches for the construction of bioequivalence (BE) limits incorporating both the intrasubject variability and the geometric mean ratio (GMR), and ii) to assess the performance of the novel approaches in comparison to several scaled BE procedures and the classic unscaled average BE. METHODS: Plots of the BE limits or the extreme GMR values accepted as a function of the coefficient of variation (CV) were constructed for published and the developed scaled procedures. Two-period crossover BE investigations with 12, 24, or 36 subjects were simulated with assumptions of a CV 10%, 20%, 30%, or 40%. The decline in the percentage of accepted studies was recorded as the true GMR for the two formulations was raised from 1.00 to 1.50. Acceptance of BE was evaluated by published and the developed scaled procedures, and, for comparison, by the unscaled average BE. RESULTS: Two GMR-dependent BE limits are proposed for the evaluation of average BE: i) BELscG1 with Ln(Upper, Lower BE limit) = +/-[(5 - 4GMR)0.496s + Ln(1.25)], and ii) BELscG2 with Ln(Upper, Lower BE limit) = +/-[(3 - 2GMR)(0.496s + Ln(1.25))], where s is the square root of the intrasubject variance. The range of BE limits becomes narrower as GMR values deviate from unity, and increases with variability. The two new approaches exhibit the highest statistical power at low CV values. At high levels of variability, BELscG1 and BELscG2 show high statistical power, as well as the lowest percentages of acceptance among the scaled methods when GMR = 1.25. The latter becomes more obvious when a large number of subjects is incorporated in the studies. CONCLUSIONS: The GMR and CV estimates of the BE study can be used in conjunction with the GMR vs. CV plot for the assessment of average BE. The new approaches, BELscG1 and BELscG2, appear to be highly effective at all levels of variation investigated. 相似文献
65.
Georgopoulos PG Fedele P Shade P Lioy PJ Hodgson M Longmire A Sands M Brown MA 《American journal of industrial medicine》2004,46(5):432-445
BACKGROUND: Hospitals distant from the immediate site of an incident involving a hazardous materials (HAZMATs) release which could include chemical warfare agents, must develop emergency response plans (ERPs) to protect healthcare professionals if they receive potentially contaminated victims. The ERP must address OSHA, EPA, and JCAHO requirements. METHODS: The VHA convened groups to develop a hazard and exposure assessment, identify actions for compliance with existing regulatory standards, and review site and operational planning issues. Exposure modeling results were used to derive relationships between operational parameters (time and distance from sites/sources) and potential exposure for healthcare workers. RESULTS: According to exposure modeling, level C personal protective equipment is adequate to protect hospital staff distant from the chemical release site. Decontamination runoff and contaminated clothing should also be controlled to limit exposure. CONCLUSIONS: Development and coordination of ERPs must include the local emergency planning committee, with clear assignment of tasks, locations, and training in order to prevent exposures to healthcare workers. 相似文献
66.
Intracytoplasmic Injection Using Spermatids and Subsequent Pregnancies: Round Versus Elongated Spermatids 总被引:6,自引:0,他引:6
The purpose of this clinical trial study was to report the outcome of intracytoplasmic injection of round (RS) and elongated (ES) spermatids retrieved from the testis of nonobstructive men. Seven and three cycles using RS and ES injections were performed, respectively. Only one cycle utilizing the late stage of ES (Sd2) resulted in an on-going pregnancy. The remarkable low success rate following RS microinjection was established in this study. 相似文献
67.
Christoforakis JJ Kontakis GM Katonis PG Maris T Voloudaki A Prassopoulos P Hadjipavlou AG 《Acta orthopaedica Belgica》2003,69(3):226-232
Sixteen patients, with a fracture of the upper humerus treated with hemiarthroplasty, were followed-up for 45.7 +/- 15.1 (20-72) months after surgery. The results were assessed using the Constant-Murley scale. The mean score was 75.8 +/- 15.7 (54-96) points out of a possible maximum of 100. At the time of their last follow-up they underwent CT of the fractured and contralateral humerus. Humeral length and retroversion were measured and evaluated. A very good final outcome (Constant score more than 71) was achieved in patients with a difference in retroversion less than 10 degrees and a difference in length less than 14 mm, between fractured and sound humerus. The mean difference in retroversion was 8.7 degrees and the mean difference in length was 0.65 cm, between fractured and sound humerus. We attribute the very good clinical outcome in our series to the quality of the anatomical reconstruction that was performed. 相似文献
68.
Self-immolative nitrogen mustards prodrugs cleavable by carboxypeptidase G2 (CPG2) showing large cytotoxicity differentials in GDEPT 总被引:1,自引:0,他引:1
Niculescu-Duvaz D Niculescu-Duvaz I Friedlos F Martin J Lehouritis P Marais R Springer CJ 《Journal of medicinal chemistry》2003,46(9):1690-1705
Nineteen novel potential self-immolative prodrugs and their corresponding drugs have been synthesized for gene-directed enzyme prodrug therapy (GDEPT) with carboxypeptidase G2 (CPG2) as the activating enzyme. The compounds are derived from o- and p-amino and p-methylamino aniline nitrogen mustards. Their aqueous stability, kinetics of drug release by CPG2, and cytotoxicity in the colon carcinoma cell line WiDr, expressing either surface-tethered CPG2 (stCPG2(Q)3) or control beta-galactosidase, are assessed. The effect of various structural features on stability, kinetics of activation, and biological activity is discussed. The p-methylamino prodrugs are the most stable compounds from this series, with the largest cytotoxicity differentials between CPG2-expressing and nonexpressing cells. The most potent compounds in all series are prodrugs of bis-iodo nitrogen mustards. 4-[N-[4'-Bis(2' '-iodoethyl)aminophenyl]-N'-methylcarbamoyloxymethyl]phenylcarbamoyl-l-glutamic acid, compound 39b, is 124-fold more cytotoxic to WiDr cells expressing CPG2 than to cells expressing beta-galactosidase. An additional six compounds show better cytotoxicity differential than the published N-[4-[(2-chloroethyl)(2-mesyloxyethyl)amino]benzoyl]-l-glutamic acid (CMDA) prodrug. 相似文献
69.
Purpose. To verify the Higuchi law and study the drug release from cylindrical and spherical matrices by means of Monte Carlo computer simulation.
Methods. A one-dimensional matrix, based on the theoretical assumptions of the derivation of the Higuchi law, was simulated and its time evolution was monitored. Cylindrical and spherical three-dimensional lattices were simulated with sites at the boundary of the lattice having been denoted as leak sites. Particles were allowed to move inside it using the random walk model. Excluded volume interactions between the particles was assumed. We have monitored the system time evolution for different lattice sizes and different initial particle concentrations.
Results. The Higuchi law was verified using the Monte Carlo technique in a one-dimensional lattice. It was found that Fickian drug release from cylindrical matrices can be approximated nicely with the Weibull function. A simple linear relation between the Weibull function parameters and the specific surface of the system was found.
Conclusions. Drug release from a matrix, as a result of a diffusion process assuming excluded volume interactions between the drug molecules, can be described using a Weibull function. This model, although approximate and semiempirical, has the benefit of providing a simple physical connection between the model parameters and the system geometry, which was something missing from other semiempirical models. 相似文献
70.