收费全文 | 529398篇 |
免费 | 28225篇 |
国内免费 | 493篇 |
耳鼻咽喉 | 6681篇 |
儿科学 | 16921篇 |
妇产科学 | 12537篇 |
基础医学 | 92608篇 |
口腔科学 | 12346篇 |
临床医学 | 48494篇 |
内科学 | 95430篇 |
皮肤病学 | 11868篇 |
神经病学 | 34006篇 |
特种医学 | 19755篇 |
外国民族医学 | 53篇 |
外科学 | 78060篇 |
综合类 | 7610篇 |
现状与发展 | 2篇 |
一般理论 | 107篇 |
预防医学 | 38532篇 |
眼科学 | 11938篇 |
药学 | 41405篇 |
1篇 | |
中国医学 | 1126篇 |
肿瘤学 | 28636篇 |
2021年 | 3891篇 |
2018年 | 5731篇 |
2017年 | 4126篇 |
2016年 | 4869篇 |
2015年 | 5360篇 |
2014年 | 7114篇 |
2013年 | 10498篇 |
2012年 | 15572篇 |
2011年 | 17389篇 |
2010年 | 9955篇 |
2009年 | 8821篇 |
2008年 | 15710篇 |
2007年 | 17443篇 |
2006年 | 16939篇 |
2005年 | 16259篇 |
2004年 | 15880篇 |
2003年 | 15261篇 |
2002年 | 14782篇 |
2001年 | 22428篇 |
2000年 | 22970篇 |
1999年 | 18919篇 |
1998年 | 5232篇 |
1997年 | 4364篇 |
1996年 | 4397篇 |
1995年 | 4124篇 |
1992年 | 14413篇 |
1991年 | 15817篇 |
1990年 | 15949篇 |
1989年 | 15625篇 |
1988年 | 14308篇 |
1987年 | 14198篇 |
1986年 | 13168篇 |
1985年 | 12686篇 |
1984年 | 9394篇 |
1983年 | 8000篇 |
1982年 | 4177篇 |
1979年 | 8937篇 |
1978年 | 6382篇 |
1977年 | 5149篇 |
1976年 | 5504篇 |
1975年 | 6613篇 |
1974年 | 7419篇 |
1973年 | 7158篇 |
1972年 | 6597篇 |
1971年 | 6309篇 |
1970年 | 5887篇 |
1969年 | 5467篇 |
1968年 | 5161篇 |
1967年 | 4621篇 |
1966年 | 3963篇 |
Objective
Hypertonic saline (HTS) has potent immune and vascular effects. We assessed recipient pretreatment with HTS on allograft function in a porcine model of heart transplantation and hypothesized that HTS infusion would limit endothelial and left ventricular (LV) dysfunction following transplantation.Methods
Heart transplants were performed after 6 hours of cold ischemic storage. Recipient pigs were randomized to treatment with or without HTS (7.5% NaCl) before cardiopulmonary bypass (CPB). Using a myograft apparatus, coronary artery endothelial-dependent (Edep) and -independent (Eind) relaxation was assessed. LV performance was determined using pressure-volume loop analysis. Pulmonary interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α expression was measured.Results
Weaning from CPB and LV performance after transplantation were improved in HTS-treated animals. Successful weaning from CPB was greater in the HTS-treated hearts (8 of 8 vs 2 of 8; P < .05). Mean LV functional recovery was improved in the HTS-treated animals, as assessed by preload recruitable stroke work (65 ± 10% vs 27 ± 10%; P < .001) and end-systolic elastance (55 ± 7% vs 37 ± 4%; P < .001). Treatment with HTS resulted in improved Edep (mean maximum elastance [Emax], 56 ± 5% vs 37 ± 7%; P < .001) and Eind (mean Emax%, 77 ± 6% vs 52 ± 4%; P < .001) vasorelaxation compared with control. Pulmonary expression of IL-2, IL-6, and TNF-α increased following transplantation, whereas HTS therapy attenuated IL production (P < .001). Transplantation increased plasma TNF-α levels and LV TNF-α expression, whereas HTS prevented this up-regulation (P < .001).Conclusions
Recipient HTS pretreatment preserves allograft vasomotor and LV function, and HTS therapy limits CPB-induced injury. HTS may be a novel recipient intervention to prevent graft dysfunction. 相似文献Aims
Variations of the anatomy of donor hepatic arteries increase the number of arterial anastomoses during liver transplantation and, possibly, the incidence of hepatic artery thrombosis (HAT). In this study, we describe the arterial anatomic variations in liver grafts procured and transplanted by a single center in Greece, the techniques of arterial anastomosis, and their effect on the incidence of early HAT.Materials and Methods
From January 2013 to December 2017, the arterial anatomy of 116 grafts procured for liver transplantation were recorded, as well as the technique of arterial anastomosis and the incidence of early hepatic artery thrombosis (HAT <30 days).Results
A single hepatic artery was recorded in 72.41% of the procured grafts, an aberrant left hepatic artery (accessory or replaced) in 18 grafts (15.52%), and an aberrant right hepatic artery (accessory or replaced) in 17 grafts (14.66%), while other variations were observed in less than 1% of the procured livers. Of the 116 primary liver transplantations, 6 patients (5.17%) developed early HAT <30 days. Two of these patients (1.72%) had 1 anastomosis of the hepatic artery and 4 (3.45%) had 2 anastomoses due to anatomic variations.Conclusions
Anatomic variations of the hepatic artery in liver grafts is a common finding and increase the incidence of early HAT but not to a degree to make these grafts unusable. 相似文献Areas covered: the principal pharmacogenetic and non-genetic differences in the pharmacology of tamoxifen and endoxifen are evaluated. To this end, references from PubMed, Embase or Web of Science, among others, were reviewed As non-genetic factors, important differences and similarities such age, or adherence to tamoxifen therapy are comprehensively illustrated. Additionally, since CYP2D6 genotypes are considered the main limitation of tamoxifen, many studies have investigated the association between the worsened clinical outcomes in patients with non-functional CYP2D6 genotypes. In this review, an overview of the research on this field is presented. Also, a summary describing the literature about individualizing tamoxifen therapy with endoxifen concentrations and its limitations is listed.
Expert opinion: z-endoxifen hydrochloride is only investigated in the metastatic setting, still more research is required before its place in therapeutics is known. Similarly, monitoring tamoxifen efficacy based on endoxifen concentrations might not be overall recommended due to the limited evidence available. 相似文献
Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.
Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.
Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents. 相似文献