全文获取类型
收费全文 | 15158篇 |
免费 | 1017篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 150篇 |
儿科学 | 584篇 |
妇产科学 | 390篇 |
基础医学 | 1836篇 |
口腔科学 | 134篇 |
临床医学 | 2238篇 |
内科学 | 2732篇 |
皮肤病学 | 218篇 |
神经病学 | 1640篇 |
特种医学 | 286篇 |
外科学 | 1346篇 |
综合类 | 161篇 |
一般理论 | 15篇 |
预防医学 | 2128篇 |
眼科学 | 340篇 |
药学 | 873篇 |
中国医学 | 11篇 |
肿瘤学 | 1118篇 |
出版年
2024年 | 21篇 |
2023年 | 136篇 |
2022年 | 230篇 |
2021年 | 538篇 |
2020年 | 329篇 |
2019年 | 499篇 |
2018年 | 518篇 |
2017年 | 388篇 |
2016年 | 413篇 |
2015年 | 427篇 |
2014年 | 580篇 |
2013年 | 878篇 |
2012年 | 1207篇 |
2011年 | 1337篇 |
2010年 | 681篇 |
2009年 | 586篇 |
2008年 | 1015篇 |
2007年 | 1050篇 |
2006年 | 1011篇 |
2005年 | 895篇 |
2004年 | 792篇 |
2003年 | 769篇 |
2002年 | 655篇 |
2001年 | 79篇 |
2000年 | 62篇 |
1999年 | 84篇 |
1998年 | 125篇 |
1997年 | 90篇 |
1996年 | 70篇 |
1995年 | 69篇 |
1994年 | 66篇 |
1993年 | 51篇 |
1992年 | 44篇 |
1991年 | 34篇 |
1990年 | 28篇 |
1989年 | 29篇 |
1988年 | 27篇 |
1987年 | 19篇 |
1986年 | 30篇 |
1985年 | 33篇 |
1984年 | 33篇 |
1983年 | 20篇 |
1982年 | 30篇 |
1981年 | 32篇 |
1980年 | 33篇 |
1979年 | 14篇 |
1978年 | 18篇 |
1976年 | 18篇 |
1974年 | 11篇 |
1971年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Timothy W Puetz Kathryn M Beasman Patrick J O'Connor 《European journal of cardiovascular prevention and rehabilitation》2006,13(6):886-893
BACKGROUND: Physical activity is a healthful behavior that has promise for combating feelings of low energy and fatigue. Despite evidence suggesting that fatigue is a prodromal symptom of major cardiac events, improvements in feelings of energy and fatigue have largely been ignored by reviewers of cardiac rehabilitation literature who have focused on anxiety, depression and general measures of quality of life. DESIGN: A meta-analytical review. METHODS AND RESULTS: Computer databases were searched from January 1945 to May 2005 to identify relevant literature. A total of 36 studies consisting of 4765 subjects were included. Cardiac rehabilitation exercise programs were consistently associated with increases in energy and decreases in fatigue. The magnitude of the effect was moderately large (mean delta 0.51; 95% confidence interval 0.42-0.61) but was heterogeneous and modified by features of the research design. Comparison of effect sizes in cardiac rehabilitation studies concurrently measuring energy/fatigue, anxiety and depression suggest that exercise-based cardiac rehabilitation programs have larger effects on feelings of energy and fatigue compared with anxiety and depression. CONCLUSION: This review quantifies the potential benefit of cardiac rehabilitation exercise programs on feelings of energy and fatigue, and suggests that cardiac rehabilitation researchers and practitioners may benefit from examining, and perhaps even focusing on, feelings of energy and fatigue as an important outcome variable. A greater understanding of the effect of cardiac rehabilitation exercise programs on feelings of energy and fatigue will be reached when more true experiments are conducted thereby avoiding the primary limitation of the literature reviewed; that is, the frequent use of non-experimental research designs. 相似文献
2.
Fibromyalgia is a syndrome of widespread pain, nonrestorative sleep, disturbed mood, and fatigue. Optimal treatment involves
a multidisciplinary approach with a team of health care providers using pharmacologic and nonpharmacologic treatment. Because
of the heterogeneity of the illness, management should be individualized for the patient. Pharmacologic treatment should address
issues of pain control, sleep disturbance, fatigue, and any underlying coexisting mood disorder. Nonpharmacologic treatment
should include patient education, a regular exercise and stretching program, and cognitive behavioral therapy. All of these
are essential to improving functional capacity and quality of life. This review provides general guidelines in initiating
a successful pharmacologic treatment program for patients with fibromyalgia. 相似文献
3.
Kay Kathryn L Roberts Beverley J Turnbull 《The Australian journal of advanced nursing》2002,20(2):8-14
The aim of this study was to document the amount of recent change in Australian nurse academics' scholarly productivity and to investigate the influence of demographic factors such as gender, academic rank, qualifications, increase in qualifications, state of residence, university and university size. Scholarly productivity was calculated from an audit of journal articles. The findings of this study indicate that, while there has been a slight increase in scholarly productivity in the last five years, nursing still lags behind other disciplines. Scholarly productivity was found to be positively associated with highest academic qualification, academic rank and promotion. The study indicates the continuing need for senior nurse academics to provide mentoring to colleagues and foster the development of skills associated with scholarly productivity. 相似文献
4.
Kathryn Nichol Sean P. Deeny Joseph Seif Kevin Camaclang Carl W. Cotman 《Alzheimer's & dementia》2009,5(4):287-294
BackgroundHuman studies on exercise, cognition, and apolipoprotein E (APOE) genotype show that ε4 carriers may benefit from regular physical activity.MethodsWe examined voluntary wheel-running, memory, and hippocampal plasticity in APOE ε3 and APOE ε4 transgenic mice at 10–12 months of age.ResultsSedentary ε4 mice exhibited deficits in cognition on the radial-arm water maze (RAWM), a task dependent on the hippocampus. Six weeks of wheel-running in ε4 mice resulted in improvements on the RAWM to the level of ε3 mice. Hippocampal brain-derived neurotrophic factor (BDNF) levels were similar in ε3 and ε4 mice, and after exercise BDNF was similarly increased in both ε3 and ε4 mice. In sedentary ε4 mice, tyrosine kinase B (Trk B) receptors were reduced by 50%. Exercise restored Trk B in ε4 mice to the level of ε3 mice, and in ε4 mice, exercise dramatically increased synaptophysin, a marker of synaptic function.ConclusionsOur results support the hypothesis that exercise can improve cognitive function, particularly in ε4 carriers. 相似文献
5.
FDA’S Perspectives on Cardiovascular Devices 总被引:1,自引:0,他引:1
Eric A. Chen Sonna M. Patel-Raman Kathryn O’Callaghan Matthew G. Hillebrenner 《Journal of cardiovascular translational research》2009,2(2):143-146
The Food and Drug Administration (FDA) decision process for approving or clearing medical devices is often determined by a
review of robust clinical data and extensive preclinical testing of the device. The mission statement for the Center for Devices
and Radiological Health (CDRH) is to review the information provided by manufacturers so that it can promote and protect the
health of the public by ensuring the safety and effectiveness of medical devices deemed appropriate for human use (Food, Drug
& Cosmetic Act, §903(b)(1, 2(C)), December 31, 2004; accessed December 17, 2008 ). For high-risk devices, such as ventricular assist devices (VADs), mechanical heart valves, stents, cardiac resynchronization
therapy (CRT) devices, pacemakers, and defibrillators, the determination is based on FDA’s review of extensive preclinical
bench and animal testing followed by use of the device in a clinical trial in humans. These clinical trials allow the manufacturer
to evaluate a device in the intended use population. FDA reviews the data from the clinical trial to determine if the device
performed as predicted and the clinical benefits outweigh the risks. This article reviews the regulatory framework for different
marketing applications related to cardiovascular devices and describes the process of obtaining approval to study a cardiovascular
device in a U.S. clinical trial. 相似文献
6.
7.
8.
Pamela D Reiter Adam A Rosenberg Robert Valuck Kathryn Novak 《Journal of perinatology》2005,25(2):125-129
OBJECTIVE: To determine the effectiveness of a 10-day subcutaneous erythropoietin (rHuEpo) course of 300 units per kg per dose plus oral iron compared to oral iron alone in anemic infants during their convalescent phase of illness. STUDY DESIGN: Prospective, randomized trial performed at a 40-bed, teaching, referral, level III, neonatal intensive care unit. Infants with a gestational age at birth of less than 32 weeks, hematocrit of less than or equal to 28% with a corrected reticulocyte count of less than or equal to 5%, postconceptual age of less than 48 weeks or 5 months chronological age, and a diagnosis of anemia of prematurity were considered for inclusion. Major outcome parameters included hematocrit, corrected reticulocyte count and red cell transfusion requirements. RESULTS: A total of 60 infants were enrolled (n=30 per group). Infants randomized to rHuEpo had a significantly higher post-treatment hematocrit and corrected reticulocyte count than infants in the iron only group (p<0.001). There was a trend towards fewer red cell requirements in the rHuEpo group. CONCLUSIONS: The rHuEpo regimen studied here was associated with an acute improvement in hematocrit and corrected reticulocyte counts. This study did not demonstrate a statistically significant decrease in transfusion therapy, in part related to increased subsequent use of rHuEpo in the control group. Taken together, these data demonstrate that this regimen can effectively treat anemia in convalescent premature infants. 相似文献
9.
Christian J. Sauder Cheryl X. Zhang Malen A. Link W. Paul Duprex Kathryn M. Carbone Steven A. Rubin 《Vaccine》2009
The recent global resurgence of mumps has drawn attention to the continued need for robust mumps immunization programs. Unfortunately, some vaccines derived from inadequately attenuated vaccine strains of mumps virus have caused meningitis in vaccinees, leading to withdrawal of certain vaccine strains from the market, public resistance to vaccination, or in some cases, cessation of national mumps vaccination programs. The most widely implicated mumps vaccine in cases of postvaccination meningitis is derived from the Urabe AM9 strain, which remains in use in some countries. The Urabe AM9 vaccine virus has been shown to exhibit a considerable degree of nucleotide and amino acid heterogeneity. Some studies have specifically implicated variants containing a lysine residue at amino acid position 335 in the hemagglutinin-neuraminidase (HN) protein with neurotoxicity, whereas a glutamic acid residue at this position was associated with attenuation. To test this hypothesis we generated two modified Urabe AM9 cDNA clones coding either for a lysine or a glutamic acid at position 335 in the HN gene. The two viruses were rescued by reverse genetics and characterized in vitro and in vivo. Both viruses exhibited similar growth kinetics in neuronal and non-neuronal cell lines and were of similar neurotoxicity when tested in rats, suggesting that amino acid 335 is not a crucial determinant of Urabe AM9 growth or neurovirulence. 相似文献
10.
Movement detection at the human big toe 总被引:1,自引:1,他引:0