全文获取类型
收费全文 | 20589篇 |
免费 | 1699篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 261篇 |
儿科学 | 708篇 |
妇产科学 | 552篇 |
基础医学 | 2545篇 |
口腔科学 | 207篇 |
临床医学 | 3034篇 |
内科学 | 3740篇 |
皮肤病学 | 229篇 |
神经病学 | 2109篇 |
特种医学 | 425篇 |
外科学 | 2022篇 |
综合类 | 244篇 |
一般理论 | 15篇 |
预防医学 | 2904篇 |
眼科学 | 437篇 |
药学 | 1361篇 |
中国医学 | 16篇 |
肿瘤学 | 1511篇 |
出版年
2023年 | 155篇 |
2022年 | 258篇 |
2021年 | 618篇 |
2020年 | 380篇 |
2019年 | 571篇 |
2018年 | 621篇 |
2017年 | 462篇 |
2016年 | 479篇 |
2015年 | 522篇 |
2014年 | 687篇 |
2013年 | 1033篇 |
2012年 | 1458篇 |
2011年 | 1584篇 |
2010年 | 836篇 |
2009年 | 732篇 |
2008年 | 1236篇 |
2007年 | 1314篇 |
2006年 | 1246篇 |
2005年 | 1136篇 |
2004年 | 998篇 |
2003年 | 1000篇 |
2002年 | 856篇 |
2001年 | 258篇 |
2000年 | 277篇 |
1999年 | 285篇 |
1998年 | 203篇 |
1997年 | 159篇 |
1996年 | 128篇 |
1995年 | 114篇 |
1994年 | 105篇 |
1993年 | 110篇 |
1992年 | 195篇 |
1991年 | 203篇 |
1990年 | 185篇 |
1989年 | 181篇 |
1988年 | 171篇 |
1987年 | 139篇 |
1986年 | 144篇 |
1985年 | 135篇 |
1984年 | 98篇 |
1983年 | 88篇 |
1982年 | 81篇 |
1981年 | 88篇 |
1980年 | 85篇 |
1979年 | 75篇 |
1978年 | 60篇 |
1976年 | 40篇 |
1974年 | 43篇 |
1973年 | 40篇 |
1972年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
S de Bustros J T Thompson R G Michels T A Rice B M Glaser 《The British journal of ophthalmology》1988,72(9):692-695
We used vitreous surgery to remove idiopathic epiretinal membranes from the macular area in 70 consecutive cases. The abnormal tissue was successfully removed in each case. Vision improved postoperatively in 61 eyes (87%), remained unchanged in six eyes (9%), and worsened in three eyes (4%). However, at the time of final examination vision was improved in only 47 eyes (67%), primarily because of the occurrence or progression of nuclear sclerosis, which occurred in 38 of 60 phakic eyes (63%). Four preoperative factors were associated with final visual acuity of 20/60 or better: (1) initial vision of 20/100 or better, (2) shorter preoperative duration of blurred vision, (3) thin epiretinal membrane, and (4) absence of traction retinal detachment. 相似文献
22.
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
23.
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
24.
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
25.
26.
27.
Cystic Fibrosis has effects on many body systems, including the skeletal system. In this case, we describe the impact of respiratory and endocrine disease on bone healing following orthopedic trauma in a 22-year-old woman. Limitations to mobility resulting from trauma complicated her respiratory condition. Disease-related effects on bone health and healing delayed her recovery from the trauma. It is important to recognize the multisystemic nature of CF, even when managing acute orthopedic injuries. 相似文献
28.
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
29.
Kathryn A Atchison Melanie W Gironda Edward E Black Stuart Schweitzer Claudia Der-Martirosian Alan Felsenfeld Richard Leathers Thomas R Belin 《Journal of oral and maxillofacial surgery》2007,65(12):2430-2437
PURPOSE: Patient preferences for treatment choices may depend on patient characteristics. Using standard gamble (SG) and willingness to pay (WTP), this study compares preferences for treatment of mandibular fracture among patients in a low-income urban area. PATIENTS AND METHODS: Surveys of African-American and Hispanic adults receiving treatment at King/Drew Medical Center for either mandibular fracture (n = 98) or third molar removal (n = 105) were used to investigate differences in patient characteristics across treatment groups (third molar vs fracture) and treatment preference (wiring vs surgery). RESULTS: The fracture patients were willing to pay more to restore function without scarring or nerve damage than were the third molar patients. Patients who chose surgery were willing to accept a greater risk of possible nerve damage or scarring than those who chose wiring. Among 15 potential predictors of SG and WTP studied in 4 subgroups defined by actual treatment and treatment preference, significant predictors varied, with associations for education and clinical experience for SG and associations with income and psychosocial predictors for WTP. CONCLUSIONS: SG and WTP capture different domains of health values in patients. There is considerable heterogeneity in relationships among patient characteristics and patient preferences across subgroups defined by actual treatment and treatment preferences. 相似文献
30.