全文获取类型
收费全文 | 25132篇 |
免费 | 1648篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 203篇 |
儿科学 | 879篇 |
妇产科学 | 703篇 |
基础医学 | 3095篇 |
口腔科学 | 260篇 |
临床医学 | 3949篇 |
内科学 | 4543篇 |
皮肤病学 | 299篇 |
神经病学 | 2482篇 |
特种医学 | 525篇 |
外科学 | 2047篇 |
综合类 | 278篇 |
一般理论 | 64篇 |
预防医学 | 3674篇 |
眼科学 | 334篇 |
药学 | 1442篇 |
1篇 | |
中国医学 | 26篇 |
肿瘤学 | 2023篇 |
出版年
2023年 | 96篇 |
2022年 | 155篇 |
2021年 | 428篇 |
2020年 | 290篇 |
2019年 | 455篇 |
2018年 | 549篇 |
2017年 | 427篇 |
2016年 | 439篇 |
2015年 | 493篇 |
2014年 | 778篇 |
2013年 | 1237篇 |
2012年 | 1793篇 |
2011年 | 1870篇 |
2010年 | 1019篇 |
2009年 | 889篇 |
2008年 | 1721篇 |
2007年 | 1815篇 |
2006年 | 1803篇 |
2005年 | 1841篇 |
2004年 | 1761篇 |
2003年 | 1668篇 |
2002年 | 1539篇 |
2001年 | 178篇 |
2000年 | 122篇 |
1999年 | 239篇 |
1998年 | 335篇 |
1997年 | 239篇 |
1996年 | 234篇 |
1995年 | 223篇 |
1994年 | 190篇 |
1993年 | 183篇 |
1992年 | 116篇 |
1991年 | 108篇 |
1990年 | 90篇 |
1989年 | 100篇 |
1988年 | 86篇 |
1987年 | 78篇 |
1986年 | 79篇 |
1985年 | 85篇 |
1984年 | 118篇 |
1983年 | 114篇 |
1982年 | 135篇 |
1981年 | 121篇 |
1980年 | 114篇 |
1979年 | 60篇 |
1978年 | 64篇 |
1977年 | 63篇 |
1976年 | 47篇 |
1975年 | 43篇 |
1974年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Severe persistent asthma can have a substantial impact on a patient's health-related quality of life (HRQL), both as a result of symptoms and from side effects of treatment. The HRQL impact of two doses (400 and 800 microg twice daily) of mometasone furoate dry powder inhaler (MF DPI) was compared with placebo in patients with severe persistent asthma previously maintained on oral steroids as a component of a previously published randomized, 12-week, double-blind, placebo-controlled, multicenter trial. A 9-month open-label extension (OLE), with all patients treated with MF DPI, followed. Patients 12 years of age or older completed a generic HRQL measure, the Medical Outcomes Trust Short Form-36 (SF-36), and an asthma-specific measure, the Marks Asthma Quality of Life Questionnaire (AQLQ-M), at baseline, at endpoint (last evaluable visit) of the double-blind phase (EODBP), and after the first 3 months of the OLE. Of 132 patients enrolled in the study, 128 provided HRQL data at baseline and at EODBP. Mean SF-36 scores at baseline showed significant HRQL impairment compared with U.S. general population norms. With treatment, the reduction in oral corticosteroid (OCS) requirements of the MF-DPI-treated groups was accompanied by significant (p < 0.05) improvement over placebo in the physical domain of HRQL (SF-36 physical component summary score and the physical function subscale) at EODBP. MF-DPI-treated patients also showed significant improvements at EODBP in each of the four subscales of the AQLQ-M (p<0.05). From EODBP to the OLE 3-month endpoint, patients treated with MF DPI twice daily maintained, or improved, SF-36 scores in most domains. Symptomatic improvement and reduction in OCS use with MF DPI were accompanied by significant improvement in HRQL in patients with severe persistent asthma. These improvements were maintained during the 3-month period of the OLE in which HRQL was evaluated. 相似文献
2.
Tony R Cucuzzella Elva G Delport Nancy Kim Julie Marley Christine Pruitt Anton G Delport 《The spine journal》2006,6(4):364-369
BACKGROUND CONTEXT: Substantial variation exists regarding the use of sedation before interventional spine techniques. Patient preference should play an important role in decision making regarding the need for sedation. However, little is known about patients' anxiety levels before spinal injections and their perceptions about the necessity of sedation. PURPOSE: To determine patient perception for need for sedation before epidural steroid injections and zygapophyseal joint injections. STUDY DESIGN/SETTING: Survey of consecutive spinal injection patients in an outpatient spine center. PATIENT SAMPLE: 500 consecutive lumbar, thoracic, and cervical patients receiving spinal injections. OUTCOME MEASURES: A 12-item questionnaire assessing patients' perceived anxiety before to a spinal injection. METHODS: Subjects were given the questionnaire after their spinal injection. Percentages requesting sedation for a first and potential second procedure were assessed. Additionally, anxiety level and pain rating, location of injection, age, sex, and other medication use were analyzed to determine the effect on the request for sedation. RESULTS: 17% of patients questioned requested sedation before an injection, and 28% would request sedation if they were to have a second injection. CONCLUSIONS: Routine sedation before diagnostic and therapeutic injections is not necessary as the majority of patients would not request sedation before the procedure when given the option. However, in some patients sedation is indicated, and all patients would benefit from educational material on sedation before the injection. 相似文献
3.
4.
5.
Nancy L. Snyderman 《The Laryngoscope》1987,97(3):353-356
Trichinosis is a rare cause of a neck mass, but should be considered by the physician when contemplating a differential diagnosis. This disease is still endemic in parts of the world and is directly related to the ingestion of incompletely cooked pork. A case is presented in which a 68-year-old man was diagnosed as having a squamous cell carcinoma of the mandible only to have trichinosis diagnosed on the final pathologic report. The case presentation is followed by a historical review and discussion. 相似文献
6.
7.
8.
Philip S Wells Josdalyne L Anderson Marc A Rodger Nancy Carson Rebecca L Grimwood Steve P Doucette 《Blood coagulation & fibrinolysis》2006,17(7):533-538
The substitution of leucine for valine at amino acid position 34 of the factor XIII gene is commonly referred to as FXIII Val34Leu polymorphism. The homozygous leucine/leucine genotype has been reported to confer protection against venous thromboembolism, but previous studies have not evaluated a population limited to those with idiopathic venous thromboembolism. The primary objective of the study was to determine whether the FXIII Val34Leu polymorphism is independently associated with the occurrence of idiopathic venous thromboembolism. We prospectively enrolled consecutive patients with at least one objectively confirmed idiopathic venous thromboembolism. Friends of cases were recruited as controls and matched to cases by sex, ethnicity, and age. All participants were tested for the FXIII Val34Leu polymorphism in addition to several well-known thrombophilias. Data from 309 cases and 306 controls were analyzed. The FXIII leucine/leucine genotype was present in 4.9% of cases and 6.5% of controls. An adjusted odds ratio of 0.59 (95% confidence interval, 0.25-1.38) was found for the recessive model and 0.69 (95% confidence interval, 0.46-1.02) for the dominant model. Our results do not support an independent association of the FXIII Val34Leu polymorphism with idiopathic venous thromboembolism in our Caucasian Canadian study population. 相似文献
9.
The development of a unifying framework for conceptualizing the commonalities in various forms of substance abuse must encompass the data base focused upon the stimulus functions of drugs. In the first instance, for example, the research on drug self-administration has provided convincing evidence of a remarkable concordance between laboratory animals and human substance abusers in the reinforcing stimulus functions of a range of chemical agents. The recognition of these cross-species and cross-drug generalities has radically changed conceptualizations of substance abuse from a reactive to a more active process and has encouraged the kind of functional analysis of drug-seeking and drug-taking that has proven productive and useful in the study of other behavioral interactions. In this regard as well, recent refinements in the analysis of the discriminative stimulus functions of drugs have provided a more comprehensive basis for characterizing a chemical agent's spectrum of action and evaluating its abuse liability. While the correlation between the discriminative stimulus functions and the reinforcing stimulus functions is remarkably high for some drug classes, there are notable exceptions. Finally, the assessment of abuse liability requires an analysis of the eliciting stimulus functions of drugs as reflected by the physiological and behavioral changes, both acute and chronic, that follow drug administration. The methods used to evaluate both physiological dependence and behavioral toxicity in relationship to sensory and motor effects for a range of abused drugs have depended heavily upon an assessment of the eliciting stimulus functions of such compounds. 相似文献
10.
Frances Rudnick Levin Judith M. Hess David A. Gorelick Nancy A. Kreiter Paul J. Fudala 《The American journal on addictions / American Academy of Psychiatrists in Alcoholism and Addictions》1993,2(2):109-115
The authors systematically evaluated the frequency patterns of cocaine use in 85 cocaine-dependent outpatients and found four patterns of use: continuous (27%), intermittent patterned (35%), intermittent nonpatterned (25%), and occasional (13%). Few subjects reported consistent cycling between binges and crashes. There were no significant differences in patterns of use associated with gender, race, educational level, route of administration, or recency of heroin use. Continuous users and occasional users were older than intermittent users. Because different contingencies may control patterned vs. nonpatterned cocaine use, pattern of use may have implications for treatment, even in individuals reporting similar amounts of cocaine use. 相似文献