全文获取类型
收费全文 | 1638篇 |
免费 | 89篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 74篇 |
妇产科学 | 15篇 |
基础医学 | 169篇 |
口腔科学 | 22篇 |
临床医学 | 198篇 |
内科学 | 454篇 |
皮肤病学 | 53篇 |
神经病学 | 65篇 |
特种医学 | 307篇 |
外科学 | 98篇 |
综合类 | 31篇 |
预防医学 | 80篇 |
眼科学 | 16篇 |
药学 | 135篇 |
中国医学 | 2篇 |
肿瘤学 | 60篇 |
出版年
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 17篇 |
2020年 | 14篇 |
2019年 | 10篇 |
2018年 | 26篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 23篇 |
2014年 | 26篇 |
2013年 | 70篇 |
2012年 | 47篇 |
2011年 | 46篇 |
2010年 | 54篇 |
2009年 | 83篇 |
2008年 | 52篇 |
2007年 | 82篇 |
2006年 | 52篇 |
2005年 | 54篇 |
2004年 | 38篇 |
2003年 | 43篇 |
2002年 | 42篇 |
2001年 | 34篇 |
2000年 | 30篇 |
1999年 | 37篇 |
1998年 | 73篇 |
1997年 | 85篇 |
1996年 | 105篇 |
1995年 | 64篇 |
1994年 | 61篇 |
1993年 | 59篇 |
1992年 | 20篇 |
1991年 | 22篇 |
1990年 | 28篇 |
1989年 | 46篇 |
1988年 | 39篇 |
1987年 | 39篇 |
1986年 | 48篇 |
1985年 | 43篇 |
1984年 | 10篇 |
1983年 | 17篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1976年 | 14篇 |
1975年 | 15篇 |
1974年 | 3篇 |
排序方式: 共有1783条查询结果,搜索用时 156 毫秒
1.
2.
3.
4.
Lynne?MooreEmail author Howard?Champion Pier-Alexandre?Tardif Brice-Lionel?Kuimi Gerard?O’Reilly Ari?Leppaniemi Peter?Cameron Cameron?S.?Palmer Fikri?M.?Abu-Zidan Belinda?Gabbe Christine?Gaarder Natalie?Yanchar Henry?Thomas?Stelfox Raul?Coimbra John?Kortbeek Vanessa?K.?Noonan Amy?Gunning Malcolm?Gordon Monty?Khajanchi Teegwendé?V.?Porgo Alexis?F.?Turgeon Luke?Leenen On behalf of the International Injury Care Improvement Initiative 《World journal of surgery》2018,42(5):1327-1339
Background
The effectiveness of trauma systems in decreasing injury mortality and morbidity has been well demonstrated. However, little is known about which components contribute to their effectiveness. We aimed to systematically review the evidence of the impact of trauma system components on clinically important injury outcomes.Methods
We searched MEDLINE, EMBASE, Cochrane CENTRAL, and BIOSIS/Web of Knowledge, gray literature and trauma association Web sites to identify studies evaluating the association between at least one trauma system component and injury outcome. We calculated pooled effect estimates using inverse-variance random-effects models. We evaluated quality of evidence using GRADE criteria.Results
We screened 15,974 records, retaining 41 studies for qualitative synthesis and 19 for meta-analysis. Two recommended trauma system components were associated with reduced odds of mortality: inclusive design (odds ratio [OR] = 0.72 [0.65–0.80]) and helicopter transport (OR = 0.70 [0.55–0.88]). Pre-Hospital Advanced Trauma Life Support was associated with a significant reduction in hospital days (mean difference [MD] = 5.7 [4.4–7.0]) but a nonsignificant reduction in mortality (OR = 0.78 [0.44–1.39]). Population density of surgeons was associated with a nonsignificant decrease in mortality (MD = 0.58 [?0.22 to 1.39]). Trauma system maturity was associated with a significant reduction in mortality (OR = 0.76 [0.68–0.85]). Quality of evidence was low or very low for mortality and healthcare utilization.Conclusions
This review offers low-quality evidence for the effectiveness of an inclusive design and trauma system maturity and very-low-quality evidence for helicopter transport in reducing injury mortality. Further research should evaluate other recommended components of trauma systems and non-fatal outcomes and explore the impact of system component interactions.5.
M G Bergeron Y Bergeron M Tardif S Marchand D Beauchamp 《Antimicrobial agents and chemotherapy》1989,33(8):1342-1345
Gentamicin is a commonly used antibiotic for the treatment of gram-negative-bacterial infections. Bacterial endotoxin is liberated during antibiotic therapy, and we have shown that endotoxemic animals accumulate more aminoglycosides in their renal parenchyma than normal animals. Vasoactive mediators, such as prostaglandins and thromboxanes, are released after endotoxin and are involved in inflammation. Indomethacin, a nonsteroidal anti-inflammatory drug known to inhibit the synthesis of these hormones, was infused intravenously as a bolus (3.0 mg/kg) or as a bolus followed by a continuous infusion (0.75 mg/kg per h) to rats given gentamicin. Levels of gentamicin in serum and kidney were increased 2 h post-antibiotic treatment in the endotoxemic animals. Renal function was not significantly disturbed. Indomethacin given as a bolus failed to correct the disturbed intrarenal pharmacokinetics of gentamicin induced by endotoxin. However, a bolus followed by continuous infusion of indomethacin resulted in low cortical and high papillary levels of antibiotic. These changes were correlated with the inhibition of prostaglandin synthesis from the kidney. These observations suggest an important role for prostaglandins in the interaction among endotoxin, aminoglycosides, and the kidney. Specific inhibitors of arachidonic acid metabolites should be investigated to further understand the mechanisms of this interaction. 相似文献
6.
Effect of clindamycin on intracellular replication, protein synthesis, and infectivity of Toxoplasma gondii. 总被引:2,自引:1,他引:2 下载免费PDF全文
We studied the effects of clindamycin and a combination of clindamycin and pyrimethamine on the proliferation of Toxoplasma gondii in cultured mammalian cells and the effect of clindamycin on the parasite's RNA and protein syntheses. Infected macrophages were treated for 48 h with clindamycin or a combination of clindamycin and pyrimethamine, and the 50% inhibitory concentrations for parasite growth were 32.50 +/- 1.30 and 10.78 +/- 0.56 micrograms/ml, respectively. A modified susceptibility assay was also used to measure the effect of low concentrations of clindamycin on T. gondii. Macrophages and bovine turbinate cells were infected with low numbers of tachyzoites and were exposed to low concentrations of clindamycin for 5 days. In these systems, a concentration of 10 ng of clindamycin per ml inhibited 50% of the growth of the parasite in macrophages, while it completely prohibited the growth of the parasite in epithelial cells. When free tachyzoites were preexposed to clindamycin for 4 h, the reduction of parasite infectivity was proportional to the amount of drug; 100 ng of clindamycin per ml reduced the infectivity of T. gondii to 46.5% +/- 8.5% of that of the untreated control. A concentration of 40 micrograms of clindamycin per ml reduced protein synthesis by 56.2% +/- 6.0% but had no effect on RNA synthesis after a 4-h exposure of free tachyzoites of T. gondii to the drug. Our results show that long-term exposure to low concentrations of clindamycin reduces the level of replication of T. gondii, that clindamycin affects the protein synthesis of free parasites, and that clindamycin impairs the ability of tachyzoites to infect host cells. 相似文献
7.
M Ngeleka P Auclair D Tardif D Beauchamp M G Bergeron 《Antimicrobial agents and chemotherapy》1989,33(9):1575-1579
We previously observed that the intrarenal distribution of aminoglycosides was modified by Escherichia coli endotoxin in the absence of any major renal physiological disturbance or histological changes. In the present study, we evaluated the role of E. coli endotoxin on the intrarenal distribution of vancomycin. At the beginning of the experiment, female Sprague-Dawley rats were infused intravenously with saline (control) or endotoxin (0.25 mg/kg) during 15 min. Thereafter, saline was constantly infused for the following 4 h. Two hours after the beginning of the infusion, animals were injected intravenously with a single dose of vancomycin (20 mg/kg). The drug levels in serum; renal cortex, medulla, and papilla; and urine were evaluated from 0.08 to 24 h after injection. Analysis of the area under the curve of the drug concentration in the different kidney components versus time showed a higher accumulation of vancomycin in the renal cortex and medulla in the endotoxin-infused rats than in the normal rats (P less than 0.01). Endotoxin was associated with an increase in the half-life in serum (P less than 0.01) and a lower elimination rate constant. The total clearance of vancomycin from plasma was significantly decreased in endotoxin-treated rats (P less than 0.01). These results demonstrate that endotoxin modifies the renal handling of vancomycin. 相似文献
8.
9.
10.
François Roubille Benoît Lattuca David Busseuil Florence Leclercq Jean-Marc Davy Eric Rhéaume Jean-Claude Tardif 《Medical hypotheses》2013
Inotropic treatment remains the cornerstone for cardiogenic shock, an emergency that requires immediate resuscitative therapy before shock irreversibly damages vital organs. Although the sympathomimetic drug dobutamine is the most widely-used inotropic drug worldwide, it has several side effects including sinus tachycardia. Dobutamine partly restores systolic heart failure (HF); however, it increases the heart rate (HR) which counterbalances the beneficial effects. Ivabradine, a new selective If inhibitor, provides specific HR reduction and is indicated in stable coronary artery disease and in stable chronic HF with left ventricular dysfunction. Despite scarce data indicating beneficial effects of ivabradine in sinus tachycardia in various clinical settings, this drug remains contraindicated in acute HF. We propose that ivabradine could help to prevent the dobutamine-induced side effects, and that their combination in clinical practice could lead to pure inotropic effects, useful for the management of cardiogenic shock. 相似文献