全文获取类型
收费全文 | 2497篇 |
免费 | 165篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 16篇 |
妇产科学 | 26篇 |
基础医学 | 303篇 |
口腔科学 | 111篇 |
临床医学 | 180篇 |
内科学 | 737篇 |
皮肤病学 | 13篇 |
神经病学 | 154篇 |
特种医学 | 72篇 |
外科学 | 561篇 |
综合类 | 8篇 |
预防医学 | 68篇 |
眼科学 | 22篇 |
药学 | 92篇 |
中国医学 | 9篇 |
肿瘤学 | 286篇 |
出版年
2023年 | 15篇 |
2022年 | 38篇 |
2021年 | 74篇 |
2020年 | 42篇 |
2019年 | 59篇 |
2018年 | 83篇 |
2017年 | 61篇 |
2016年 | 73篇 |
2015年 | 71篇 |
2014年 | 90篇 |
2013年 | 141篇 |
2012年 | 198篇 |
2011年 | 193篇 |
2010年 | 110篇 |
2009年 | 96篇 |
2008年 | 173篇 |
2007年 | 192篇 |
2006年 | 151篇 |
2005年 | 154篇 |
2004年 | 134篇 |
2003年 | 134篇 |
2002年 | 125篇 |
2001年 | 23篇 |
2000年 | 31篇 |
1999年 | 29篇 |
1998年 | 16篇 |
1997年 | 19篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 13篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1976年 | 2篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 3篇 |
排序方式: 共有2674条查询结果,搜索用时 0 毫秒
41.
Mycotoxin exposure in humans is primarily assessed through its occurrence in external sources, such as food commodities. Herein, we have developed a direct competitive ELISA to facilitate the detection of aflatoxin B1 (AFB1), deoxynivalenol (DON), fumonisin (FUM B1/B2), ochratoxin A (OTA), and zearalenone (ZEA) in human serum. The analytical validation of the assay followed practices endorsed by the international research community and the EU directive 96/23/EC in order to examine detection capability, recovery, and cross-reactivity. The assay demonstrated a lower limit of quantitation (LLOQ) for AFB1 [0.61 ng/mL (hereon ng/mL = ppb)], DON (19.53 ppb), FUM (4.88 ppb), OTA (19.53 ppb), and ZEA (0.15 ppb). Recovery from human serum for all mycotoxins spanned from 73% to 106%. Likewise, the specificity for monoclonal antibodies against cross-reactant mycotoxins ranged from 2% to 11%. This study compares the LLOQ and recovery values with commercial and emerging immuno-based methods for detecting mycotoxins in foodstuffs. The LLOQ values from the present study were among the lowest in commercial or emerging methods. Despite the differences in the extraction protocols and matrices, the recovery range in this study, commercial tests, and other procedures were similar for all mycotoxins. Overall, the assay detected AFB1, DON, FUM, OTA, and ZEA in human serum with excellent accuracy, precision, and specificity. 相似文献
42.
43.
Angela Zagatina Nadezhda Zhuravskaya Maxim Kamenskikh Dmitry Shmatov Sergey Sayganov Fausto Rigo 《Ultrasound in medicine & biology》2018,44(7):1402-1410
There is a lack of information on the prognostic value of local high velocity in coronary arteries during echocardiography. The aim of the study described here was to define the prognostic value of local velocity >70?cm/s in the left main, anterior or circumflex artery during echocardiography. There were 412 patients in the prospective study. Death, non-fatal myocardial infarction, acute pulmonary edema, acute coronary syndrome and revascularization were defined as major adverse cardiac events (MACEs). Over 10.5?mo, there were 207 patients with MACEs. Seventeen patients died, 10 had non-fatal acute cardiac events and 184 underwent revascularization. Deaths occurred in patients with high local velocity (6.4% vs. 0%, p?<0.009). Acute cardiac events occurred in 10% versus 0% (p?<0.003). MACEs were observed in 62% versus 0% (p?<0.0000001). Only maximal velocity was an independent prognostic predictor of death (odds ratio?=?1.02, 95% confidence interval: 1.01–1.03, p?<0.02) and MACEs (odds ratio?=?1.04, 95% confidence interval: 1.02–1.05, p?<0.0001). The success rate of coronary artery visualization for at least one segment was 91%. 相似文献
44.
45.
46.
Robert D Catena Paul van Donkelaar Li-Shan Chou 《Journal of neuroengineering and rehabilitation》2009,6(1):25-7
The purpose of this study was to longitudinally compare the sensitivity of previously documented paradigms for measuring balance
control during gait following a concussion. We hypothesized that gait with a concurrent cognitive task would be most sensitive
to the effects of concussion on dynamic balance control. Individuals with concussion (n = 30) and matched controls (n = 30)
performed a single task of level walking, attention divided walking, and an obstacle-crossing task at two heights. Testing
occurred four times post-injury. Balance control during gait was assessed with whole-body center of mass and center of pressure
motion. The single-task level walking task did not result in any significant differences in balance control between individuals
with concussion and control subjects. Within 48 hours post-injury, individuals with concussion walked slower and allowed less
motion of their center of mass in the sagittal plane when attention was divided during walking, but there were no group differences
by day 6 for this task. Group differences in balance control during obstacle crossing was unremarkable during the first two
testing sessions, but by day 14 individuals with concussion displayed less mediolateral motion of their center of mass. Attention
divided gait is able to better distinguish gait adaptations immediately following a concussion, but obstacle crossing can
be used further along in the recovery process to detect new gait adaptations. 相似文献
47.
Decreased treatment failure in recipients of HLA-identical bone marrow or peripheral blood stem cell transplants with high CD34 cell doses 总被引:3,自引:0,他引:3
Ringdén O Barrett AJ Zhang MJ Loberiza FR Bolwell BJ Cairo MS Gale RP Hale GA Litzow MR Martino R Russell JA Tiberghien P Urbano-Ispizua A Horowitz MM 《British journal of haematology》2003,121(6):874-885
We studied the association between CD34 cell dose and transplant outcomes in 359 bone marrow (BM) and 511 peripheral blood stem cell (PBSC) transplant recipients from human leucocyte antigen (HLA)-identical siblings, reported to the International Bone Marrow Transplant Registry (IBMTR). Transplants for leukaemia were performed between 1995 and 1998. Patients were divided into those receiving below or above the median CD34+ dose, for BM (3 x 106/kg) and PBSC (6 x 106/kg) grafts respectively. Cox proportional hazards regression was used to adjust for baseline patient-, disease- and transplant-related characteristics. Analysis of the BM recipients showed that high CD34 cell dose was associated with lower transplant-related mortality [relative risk (RR) = 0.60, P = 0.033] and treatment failure (inverse of leukaemia-free survival, RR = 0.69, P = 0.032). Among PBSC recipients, high CD34 dose was associated with faster recovery of neutrophils to > 0.5 x 109/l (RR = 1.38, P < 0.001) and platelets to > 20 x 109/l (RR = 1.34, P = 0.003), lower risk of relapse (RR = 0.62, P = 0.029) and treatment failure (RR = 0.74, P = 0.03). We conclude that higher CD34 cell doses decrease treatment failure in recipients of HLA-identical sibling BM and PBSC transplants. 相似文献
48.
Staiger H Machicao F Werner R Guirguis A Weisser M Stefan N Fritsche A Häring HU 《Metabolism: clinical and experimental》2008,57(5):637-643
Angiopoietin-like protein 4 (ANGPTL4) represents an adipokine with metabolic effects within adipose tissue, such as inhibition of lipoprotein lipase activity and stimulation of lipolysis. These effects were convincingly demonstrated in mice. Therefore, we asked whether genetic variation within the ANGPTL4 gene contributes to prediabetic phenotypes, such as dyslipidemia, insulin resistance, or beta-cell dysfunction, in white subjects at an increased risk for type 2 diabetes mellitus. We genotyped 629 subjects with and without a family history of diabetes for the 4 single nucleotide polymorphisms (SNPs) rs4076317, rs2278236, rs1044250, and rs11672433 and performed correlational analyses with metabolic traits. For metabolic characterization, all subjects underwent an oral glucose tolerance test; a subset was additionally characterized by hyperinsulinemic-euglycemic clamp. The 4 SNPs rs4076317, rs2278236, rs1044250, and rs11672433 cover 100% of common genetic variation (minor allele frequency>or=0.05) within the ANGPTL4 gene (r2>or=0.8). None of these SNPs revealed significant correlation with anthropometric data (sex, age, body mass index, body fat, and waist-hip ratio) or with family history of diabetes. Furthermore, no reliable correlations were found with fasting triglycerides, fasting nonesterified fatty acids, and area under the curve of nonesterified fatty acids during oral glucose tolerance test or with parameters of insulin sensitivity and insulin secretion. Finally, haplotype analysis revealed the existence of 8 common diplotypes. None of these, however, was significantly correlated with insulin sensitivity, insulin secretion, or plasma lipid measures. We conclude that common genetic variation within the ANGPTL4 gene may not play a major role in the development of prediabetic phenotypes in our white population. 相似文献
49.
Feres F Munoz J Abizaid A Staico R Kuwabara M Mattos L Centemero M Maldonado G Albertal M Vaz VD Ferreira E Tanajura LF Chaves A Sousa A Sousa JE 《The Journal of invasive cardiology》2005,17(9):473-477
We report one-year angiographic and intravascular ultrasound (IVUS) outcomes of in-stent restenosis (ISR) patients treated with intravascular brachytherapy (IVBT). The benefit of IVBT for treating ISR is well documented. However, few data exist on significant angiographic and intravascular ultrasonic in-stent lumen deterioration beyond the habitual 6-month analysis after the index radiation procedure or so-called late catch-up process in the treatment of ISR. Twenty-five consecutive patients with ISR were treated with IVBT using the Beta-Cath System (a 40 mm 90 Sr per 90 gamma source). Quantitative angiographic and IVUS analysis was performed in all of them at 6 and 12 months. IVBT was successful in all patients. Four patients (16%) developed recurrent angiographic binary restenosis at 6-month follow-up, all located within the adjacent reference segments, with 2 being associated with geographical miss. An additional 4 patients (16%) presented with recurrent ISR at 12-month follow-up, all within the stented segment. Significant in-stent lumen loss (0.16 +/- 0.42 mm to 0.34 +/- 0.46 mm; p = 0.008) and in-stent intimal hyperplasia growth (+11.2 +/- 0.48 mm3; p = 0.03) was observed between 6 and 12 months. Intracoronary beta-radiation for the treatment of ISR was associated with significant luminal deterioration (late catch-up) within the stents between 6 and 12 months due to an important late progression of in-stent intimal hyperplasia. 相似文献
50.
Alexandre Abizaid Mariano Albertal John Ormiston Hugo Londero Peter Ruygrok Ana Cristina Seixas Fausto Feres Luiz A Mattos Rodolfo Staico Roberto L Silva Mark Webster Jim Stewart Francisco Paoletti Tori Kataoka Peter Fitzgerald Amanda Sousa J Eduardo Sousa 《Catheterization and cardiovascular interventions》2005,66(4):491-495
The purpose of the study was to examine the safety and efficacy of two different formulations of mycophenolic acid (MPA)-eluting Duraflex stents on coronary de novo lesions. Recent data indicate that local delivery of MPA in the porcine overstretch coronary model significantly reduces neointimal hyperplasia (NIH). Patients were divided into three consecutive groups. The first (n=50) and second (n=55) groups received moderate- and slow-release MPA-eluting Duraflex stent, respectively. The last group (n=50) received the bare metal Duraflex stent. Clinical, angiographic, and intravascular ultrasound analysis were performed at 6-month follow-up. All stents were successfully deployed and patients were discharged home without clinical events. Compared to controls, 6-month in-lesion and in-stent minimum luminal diameter as well as late lumen loss were not significantly different in the moderate- and slow-release treatment groups. At follow-up, percentage obstruction and NIH volume were also similar between the three groups. At 30 days and 6 and 12 months, there were no differences noted between the three groups with respect to major adverse cardiac events as well as the individual rates of mortality, myocardial infarction, or repeat revascularization. There were no cases of subacute or late thrombosis. In this feasibility trial, the MPA-eluting Duraflex stents in either slow- or moderate-release formulations were well tolerated, but showed no benefit for treatment of coronary lesions when compared to controls. Further testing with different drug dosing or delivery rate might improve these results. 相似文献