全文获取类型
收费全文 | 3696篇 |
免费 | 256篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 71篇 |
妇产科学 | 37篇 |
基础医学 | 432篇 |
口腔科学 | 71篇 |
临床医学 | 344篇 |
内科学 | 719篇 |
皮肤病学 | 55篇 |
神经病学 | 352篇 |
特种医学 | 264篇 |
外科学 | 652篇 |
综合类 | 27篇 |
一般理论 | 4篇 |
预防医学 | 277篇 |
眼科学 | 89篇 |
药学 | 186篇 |
中国医学 | 3篇 |
肿瘤学 | 314篇 |
出版年
2023年 | 65篇 |
2022年 | 123篇 |
2021年 | 187篇 |
2020年 | 117篇 |
2019年 | 154篇 |
2018年 | 162篇 |
2017年 | 119篇 |
2016年 | 123篇 |
2015年 | 185篇 |
2014年 | 173篇 |
2013年 | 184篇 |
2012年 | 285篇 |
2011年 | 246篇 |
2010年 | 145篇 |
2009年 | 112篇 |
2008年 | 180篇 |
2007年 | 197篇 |
2006年 | 144篇 |
2005年 | 144篇 |
2004年 | 141篇 |
2003年 | 83篇 |
2002年 | 99篇 |
2001年 | 39篇 |
2000年 | 44篇 |
1999年 | 41篇 |
1998年 | 19篇 |
1997年 | 23篇 |
1995年 | 12篇 |
1994年 | 15篇 |
1992年 | 29篇 |
1991年 | 37篇 |
1990年 | 28篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 21篇 |
1986年 | 22篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1979年 | 12篇 |
1973年 | 12篇 |
1972年 | 9篇 |
1971年 | 7篇 |
1969年 | 7篇 |
1968年 | 9篇 |
1967年 | 9篇 |
1966年 | 9篇 |
1922年 | 7篇 |
排序方式: 共有3969条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
T W Mattox R O Brown B A Boucher E A Buonpane T C Fabian R W Luther 《JPEN. Journal of parenteral and enteral nutrition》1988,12(6):592-596
The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin-C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched-chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched-chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin-C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin-C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin-C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin-C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin-C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients. 相似文献
7.
Research letter: How should abridged scientific articles be presented in journals? A survey of readers and authors 下载免费PDF全文
Marcus Müllner Fabian Waechter Sara Schroter Barbara Squire 《Canadian Medical Association journal》2005,172(2):203-205
SEVERAL SCIENTIFIC AND GENERAL MEDICAL JOURNALS publish full-length articles on their Web sites and abridged versions in their print journals. We surveyed a stratified random sample of BMJ readers and authors to elicit their preferred format for the abridged print version. Each participant received a research paper abridged in 3 different formats: conventional abridged version, journalistic version and enhanced-abstract version. Overall, 45% (95% confidence interval [CI] 42%–48%) of the respondents said they liked the conventional version most, 31% (95% CI 28%–34%) preferred the journalistic version and 25% (95% CI 22%–27%) preferred the enhanced-abstract version. Twenty-eight percent (95% CI 25%–32%) indicated that use of the journalistic format for abridged articles would very likely stop them from submitting papers to BMJ, and 13% (95% CI 11%–16%) said the use of the enhanced-abstract version would stop them from submitting to BMJ. Publishers of general medical journals who publish shortened articles should consider that authors and readers prefer a more conventional style of abridged papers. 相似文献
8.
Interleukin–2 and hyperthermia have been used individually to treat a variety of tumors in both experimental and human trials. Combined adoptive immunotherapy and hyperthermia is an exciting new line of investigation. Previous work in our laboratory has shown that combined local hyperthermia and rIL-2 therapy can significantly decrease the rate of tumor growth. In this study, we investigated the effect of combined whole-body hyperthermia (WBHT) and rIL-2 on the growth of subcutaneous MCA-105 murine tumors in C57BL/6 mice. Treatment of both microscopic (day 3) and macroscopic (day 10) tumors was evaluated. In the treatment of microscopic tumors, animals received either no treatment; rIL-2 (3 × 105 IU ip tid) on days 3–7; plus WBHT(41°C for 30 min) on days 3, 5, and 7; or WBHT only on days 3, 5, and 7. In treating macroscopic tumors, animals received either no treatment; rIL-2 on days 10–14; plus WBHT on days 10, 12, and 14; or WBHT only on days 10, 12, and 14. While combined treatment and WBHT alone had no significant effect on the growth of microscopic tumors, combined IL-2 and WBHT significantly reduced the rate of tumor growth of macroscopic tumors. These results suggest that the tumor microenvironment plays a critical role in combined WBHT and rIL-2 therapy, and may be due to effects of WBHT on the tumor vasculature. © 1993 Wiley-Liss, Inc. 相似文献
9.
Leonore C Dijkgraaf Gustavo Zardeneta Fabian W Cordewener Robert S b Liem John P Schmitz Lambert G m de Bont Stephen B Milam 《Journal of oral and maxillofacial surgery》2003,61(1):101-111
PURPOSE: Adhesion formation in osteoarthritis (OA) of the temporomandibular joint (TMJ) typically results in a sustained limitation of joint movement. We propose the hypothesis that free-radical-mediated crosslinking of proteins underlies this adhesion formation in affected joints. Free radicals may cause oxidative modification of proteins, creating an opportunity for the formation of intramolecular and intermolecular crosslinks via covalent bonds. This may stabilize protein aggregates, rendering them more resistant to degradation. In this study, the free-radical-mediated crosslinking of model proteins (fibrinogen and fibronectin) was investigated to test our hypothesis that free radicals contribute to adhesion formation via this mechanism in OA of the TMJ. MATERIALS AND METHODS: Physiological clot formation of fibrinogen by thrombin and free-radical-induced crosslinking of fibrinogen and of fibronectin were analyzed using spectrophotometric turbidity measurements, light-scattering techniques, polyacrylamide gel electrophoresis (PAGE), and rotary shadowing. RESULTS: Fibrinogen was shown to aggregate after free radical treatment, as detected using turbidity measurements and light-scattering techniques. Using PAGE, fibrinogen as well as fibronectin was shown to degrade under low oxidative stress. Under high oxidative stress, however, fragments from both proteins were found to be covalently crosslinked, resulting in high-molecular-weight protein aggregates. The aggregation was shown to be at random with rotary shadowing. CONCLUSION: The study shows that high oxidative stress contributes to the formation of crosslinked proteins that may serve as an initial scaffolding for the development of adhesions frequently seen in OA of the TMJ. 相似文献
10.
Safety of thrombolysis during cardiopulmonary resuscitation. 总被引:15,自引:0,他引:15
The prognosis is generally poor for patients who experience a cardiac arrest. The most common causes of sudden cardiac arrest are massive pulmonary embolism (PE) and acute myocardial infarction (MI). While thrombolysis is a first-line treatment option in massive PE and acute MI, cardiopulmonary resuscitation (CPR) has been regarded as a relative contraindication for thrombolysis because of the anticipated bleeding risk caused by traumatic cardiocompressions. However, an increasing number of case reports and clinical studies on thrombolysis during and after CPR highlight an increased frequency of the return of spontaneous circulation and a better neurological outcome of surviving patients. These effects are mainly due to the thrombolysis of macroscopic blood clots and the amelioration of microcirculatory reperfusion.This article reviews case reports and clinical studies of thrombolysis during and shortly after CPR in order to estimate the risk of severe bleeding events caused by CPR in association with thrombolysis compared with CPR without thrombolysis.Although thrombolysis per se can cause severe and potentially fatal haemorrhage, there is no evidence that severe bleeding events occur more often when thrombolysis is combined with cardiocompressions. In addition, by far the majority of bleeding complications can be treated effectively. Thus, in many cases, the possible benefit of thrombolysis during CPR seems to outweigh the potential risks. However, there may be a publication bias in some case reports and studies towards reporting successful rather than unsuccessful CPRs. In addition, not enough controlled clinical trials have yet been conducted. Therefore, data from large randomised, multicentre studies are needed to definitely answer the question of the relationship between safety and efficacy of this promising treatment option.We conclude that the currently available data do not indicate that thrombolysis contributes to a significant increase in bleeding complications when administered during CPR. 相似文献