全文获取类型
收费全文 | 124796篇 |
免费 | 8282篇 |
国内免费 | 454篇 |
专业分类
耳鼻咽喉 | 1632篇 |
儿科学 | 3297篇 |
妇产科学 | 2072篇 |
基础医学 | 16005篇 |
口腔科学 | 2371篇 |
临床医学 | 12547篇 |
内科学 | 26395篇 |
皮肤病学 | 1916篇 |
神经病学 | 11973篇 |
特种医学 | 4273篇 |
外国民族医学 | 4篇 |
外科学 | 18041篇 |
综合类 | 1894篇 |
现状与发展 | 1篇 |
一般理论 | 167篇 |
预防医学 | 11138篇 |
眼科学 | 2942篇 |
药学 | 8714篇 |
2篇 | |
中国医学 | 172篇 |
肿瘤学 | 7976篇 |
出版年
2023年 | 511篇 |
2022年 | 831篇 |
2021年 | 2074篇 |
2020年 | 1228篇 |
2019年 | 2016篇 |
2018年 | 2321篇 |
2017年 | 1789篇 |
2016年 | 1960篇 |
2015年 | 2417篇 |
2014年 | 3446篇 |
2013年 | 5339篇 |
2012年 | 7769篇 |
2011年 | 8292篇 |
2010年 | 4694篇 |
2009年 | 4520篇 |
2008年 | 7974篇 |
2007年 | 8526篇 |
2006年 | 8360篇 |
2005年 | 8648篇 |
2004年 | 8176篇 |
2003年 | 8011篇 |
2002年 | 7584篇 |
2001年 | 1192篇 |
2000年 | 936篇 |
1999年 | 1231篇 |
1998年 | 1708篇 |
1997年 | 1427篇 |
1996年 | 1164篇 |
1995年 | 1153篇 |
1994年 | 947篇 |
1993年 | 962篇 |
1992年 | 759篇 |
1991年 | 709篇 |
1990年 | 674篇 |
1989年 | 623篇 |
1988年 | 577篇 |
1987年 | 545篇 |
1986年 | 546篇 |
1985年 | 666篇 |
1984年 | 833篇 |
1983年 | 836篇 |
1982年 | 1162篇 |
1981年 | 1056篇 |
1980年 | 952篇 |
1979年 | 466篇 |
1978年 | 578篇 |
1977年 | 548篇 |
1976年 | 452篇 |
1975年 | 410篇 |
1974年 | 366篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
Steven J Lobritto Philip Rosenthal Rene Bouw Mimi Leung Paul Snell Richard D Mamelok 《Liver transplantation》2007,13(11):1570-1575
There are few pharmacokinetic data for mycophenolate mofetil (MMF) when used in combination with cyclosporine (CsA) in pediatric liver transplant recipients. The aim of this study was to assess the pharmacokinetics of MMF in stable pediatric liver transplant patients and estimate the dose of MMF required to provide a mycophenolic acid (MPA) exposure similar to that observed in adult liver transplant recipients receiving the recommended dose of MMF (target area under the plasma concentration-time curve from 0 to 12 hours [AUC(0-12)] for MPA of 29 mug.hour/mL in the immediate posttransplantation period and 58 microg x hour/mL after 6 months). A 12-hour pharmacokinetic profile was collected for 8 pediatric patients (mean age 20.9 months) on stable doses of MMF and CsA who had received a liver transplant > or = 6 months prior to entry and who had started on MMF within 2 weeks of transplantation. Mean MMF dosage was 285 mg/m(2) (range, 200-424 mg/m(2)). Of 8 patients, 7 had a MPA AUC(0-12) (range, 11.0-37.2 microg x hour/mL) well below the target. One patient had an AUC(0-12) > or = 58 microg x hour/mL but was considered an outlier and was excluded from analyses. Mean MPA AUC(0-12) and maximum plasma concentration values were 22.7 +/- 10.5 microg x hour/mL and 7.23 +/- 3.27 microg/mL, respectively; values normalized to 600 mg/m(2) (the approved pediatric dose in renal transplantation) were 47.0 +/- 21.8 microg x hour/mL and 14.5 +/- 4.21 microg/mL. In conclusion, assuming that MPA exhibits linear pharmacokinetics, when used in combination with CsA, a MMF dose of 740 mg/m(2) twice daily would be recommended in pediatric liver transplant recipients to achieve MPA exposures similar to those observed in adult liver transplant recipients. This finding should be confirmed by a prospective trial. 相似文献
75.
David H. Wilson Catherine R. Chittleborough Kerry Kirke Janet F. Grant Richard E. Ruffin 《Sozial- und Pr?ventivmedizin》2004,13(5):406-412
Objectives: Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.Methods: South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36. 相似文献
76.
77.
Scalp electrical recording during paralysis: quantitative evidence that EEG frequencies above 20 Hz are contaminated by EMG. 总被引:2,自引:0,他引:2
Emma M Whitham Kenneth J Pope Sean P Fitzgibbon Trent Lewis C Richard Clark Stephen Loveless Marita Broberg Angus Wallace Dylan DeLosAngeles Peter Lillie Andrew Hardy Rik Fronsko Alyson Pulbrook John O Willoughby 《Clinical neurophysiology》2007,118(8):1877-1888
OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation. 相似文献
78.
79.
Amit Badhwar Thomas L Forbes Marge B Lovell Alison A Dungey Sarah D McCarter Jeffrey R Scott Guy DeRose Kenneth A Harris Richard F Potter 《Canadian journal of surgery》2004,47(5):352-358
BACKGROUND: Ischemic preconditioning (IPC) has been found in animals to have a protective effect against future ischemic injury to muscle tissue. Such injury is unavoidable during some surgical procedures. To determine whether chronic ischemia in the lower extremities would imitate IPC and reduce ischemic injury during vascular surgery, we designed a controlled clinical study. PATIENTS AND METHODS: Two groups of patients at a university-affiliated medical centre with chronic lower-extremity ischemia served as models of IPC: 6 patients awaiting femoral distal bypass (FDB) and 4 scheduled for aortobifemoral (ABF) bypass grafting for aortoiliac occlusive disease. Seven patients undergoing elective open repair of an infrarenal abdominal aortic aneurysm (AAA) were chosen as non-IPC controls. Three hematologic indicators of skeletal-muscle injury, lactate dehydrogenase (LDH), creatine kinase (CK) and myoglobin, were measured before placement of the proximal clamp, during surgical ischemia, immediately upon reperfusion, 15 minutes after and 1 hour after reperfusion, and during the first, second and third postoperative days. RESULTS: Baseline markers of skeletal-muscle injury were similar in all groups. In postreperfusion samples, concentrations of muscle-injury markers were significantly lower in the 2 PC groups than in the control group. For example, at day 2, LDH levels were increased by about 30% over baseline measures in the elective AAA (control) group, whereas levels in the FDB and ABF groups remained statistically unchanged from baseline. Myoglobin in controls had increased by 977%, but only by 160% in the FDB and 528% in the ABF groups. CK levels, in a similar trend, were 1432% higher in the control group and only 111% (FDB) and 1029% (ABF) in the study groups. Taken together, these data represent a significant level of protection. CONCLUSIONS: Patients with chronic lower-extremity ischemia suffered less severe ischemic injury after a period of acute ischemia than those with acute ischemia alone. Ischemic preconditioning is one proposed mechanism to help explain this protective effect. 相似文献
80.