全文获取类型
收费全文 | 1229篇 |
免费 | 91篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 36篇 |
妇产科学 | 36篇 |
基础医学 | 152篇 |
口腔科学 | 34篇 |
临床医学 | 139篇 |
内科学 | 333篇 |
皮肤病学 | 42篇 |
神经病学 | 102篇 |
特种医学 | 27篇 |
外科学 | 96篇 |
综合类 | 11篇 |
预防医学 | 109篇 |
眼科学 | 28篇 |
药学 | 70篇 |
肿瘤学 | 99篇 |
出版年
2024年 | 1篇 |
2023年 | 18篇 |
2022年 | 45篇 |
2021年 | 65篇 |
2020年 | 31篇 |
2019年 | 40篇 |
2018年 | 35篇 |
2017年 | 30篇 |
2016年 | 43篇 |
2015年 | 36篇 |
2014年 | 50篇 |
2013年 | 72篇 |
2012年 | 94篇 |
2011年 | 110篇 |
2010年 | 56篇 |
2009年 | 56篇 |
2008年 | 85篇 |
2007年 | 77篇 |
2006年 | 83篇 |
2005年 | 78篇 |
2004年 | 60篇 |
2003年 | 46篇 |
2002年 | 52篇 |
2001年 | 12篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1991年 | 1篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1326条查询结果,搜索用时 15 毫秒
171.
Daniel E. Spratt Lucas Resende Salgado Nadeem Riaz Michael G. Doran Moses Tam Suzanne Wolden Evangelia Katsoulakis Shyam Rao Alan Ho Richard Wong Nancy Y. Lee 《Radiology and oncology》2014,48(1):56-61
Background
The results of RTOG-MRC randomized trial of photon (n=15) versus neutron (n=17) therapy in the 1980’s reported an improved local control (LC) with neutron radiotherapy for unresectable salivary gland tumors. Due to increased severe toxicity with neutron radiotherapy and the paucity of neutron-therapy centers, we analyzed our institution’s results of photon radiotherapy for unresectable salivary gland tumors.Patients and methods
From 1990 to 2009, 27 patients with unresectable salivary gland cancer underwent definitive photon radiotherapy at our institution. Nodal involvement on presentation was found in 9 patients. Median dose of radiotherapy was 70 Gy. Chemotherapy was given to 18 patients, most being platinum-based regimens. Local control (LC), locoregional control (LRC), distant metastasis-free survival (DMFS), overall survival (OS), and toxicity outcomes were assessed.Results
With a median follow-up of 52.4 months, the 2/5-year actuarial LC was 69% (95%CI ± 21.0%)/55% (± 24.2%), LRC was 65% (± 21.4%)/47% (± 21.6%), and DMFS was 71% (± 21.8%)/51% (± 22.8%), respectively using competing risk analysis. The median OS was 25.7 months, and the 2/5-year OS rates were 50% (± 19.0%)/29% (± 16.6%), respectively. Higher histologic grade was significant for an increased rate of DM (intermediate grade vs. low grade, p=0.04, HR 7.93; high grade vs. low grade, p=0.01, HR 13.50). Thirteen (48%) patient’s experienced acute grade 3 toxicity. Late grade 3 toxicity occurred in three (11%) patients.Conclusions
Our data compares favorably to neutron radiotherapy with fewer late complications. Photon radiotherapy is an acceptable alternative to neutron radiotherapy in patients who present with unresectable salivary gland tumors. 相似文献172.
Christos Chatzakis Alexandros Sotiriadis Evangelia Tsakmaki Maria Papagianni George Paltoglou Konstantinos Dinas George Mastorakos 《Nutrients》2021,13(7)
Background: Gestational diabetes mellitus (GDM) exacerbates the oxidative stress status of the pregnant women. Τo improve the oxidative stress status, several therapeutic interventions have been suggested. The aim of this network meta-analysis is to assess the effect of different dietary supplements on the oxidative stress status in pregnant women with GDM. Methods: A network meta-analysis of randomized control trials was performed comparing the changes delta (Δ) in total antioxidant capacity (TAC) and concentration of malondialdehyde (MDA) as primary outcomes, following different therapeutic interventions with dietary supplements in pregnant women with GDM. Four electronic databases and grey literature sources were searched. The secondary outcomes were other markers of oxidative stress. Results: The meta-analysis included 16 studies of 1173 women with GDM. Regarding ΔTAC: probiotics and omega-3 with vitamin E were superior to placebo/no intervention. Regarding ΔMDA: vitamin D with calcium, omega-3, vitamin D, omega-3 with vitamin E, magnesium with zinc and calcium, and probiotics were superior to placebo/no intervention. Conclusions: Administration of dietary supplements in women with GDM can be helpful in limiting the oxidative stress which develop in these pregnancies. 相似文献
173.
174.
Lambrinoudaki IV Christodoulakos GE Economou EV Vlachou SA Panoulis CP Alexandrou AP Kouskouni EE Creatsas GC 《Maturitas》2008,59(1):62-71
BACKGROUND: Leptin and ghrelin are increasingly being recognized as cardiotropic hormones, promoting or inhibiting the atherosclerotic process, respectively. Apoptosis may be one pathway through which the actions of these hormones are mediated. Sex hormones are reported to influence the secretion and action of ghrelin and leptin. OBJECTIVE: To evaluate (1) the association of circulating ghrelin and leptin with selected markers of receptor-mediated apoptosis and (2) the effect of estrogen monotherapy, low dose estrogen-progestin therapy, tibolone and raloxifene on serum ghrelin and leptin in healthy postmenopausal women. METHODS: Eighty eight postmenopausal women aged 44-62 years were randomly allocated to daily (1) conjugated equine estrogens 0.625 mg (CEE), (2) 17beta-estradiol 1mg plus norethisterone acetate 0.5 mg (E(2)/NETA), (3) tibolone 2.5mg, (4) raloxifene HCl 60 mg or (5) no treatment. Serum markers of apoptosis sFas, Fas-ligand (Fas-L) and caspase-1 were measured at baseline. Serum leptin and ghrelin were measured at baseline and at 3 months. RESULTS: Body Mass Index (BMI) and estradiol levels correlated positively, while FSH correlated negatively with serum leptin (BMI: r=0.646, p=0.005, estradiol: r=0.432, p=0.001, FSH: r=-0.401, p=0.002). Insulin levels associated positively with circulating leptin (r=0.394, p=0.011) and negatively with circulating ghrelin (r=-0.401, p=0.009). Serum leptin decreased significantly in E2/NETA group (baseline: 2.882+/-0.76 ng/ml, 3 months: 2.687+/-0.66 ng/ml, p=0.043), while it increased significantly in the raloxifene group (baseline: 2.671+/-0.54 ng/ml, 3 months: 2.839+/-0.47 ng/ml). Ghrelin levels decreased significantly only in the raloxifene group (baseline: 1634+/-592 pg/ml, 3 months: 1408+/-534 pg/ml). CONCLUSION: Apoptosis may be a pathway through which leptin exerts a pro-atherogenic effect. Low dose HT may act cardioprotectively by decreasing leptin levels in healthy recently menopaused women. 相似文献
175.
Santamaria R Michelakakis H Moraitou M Dimitriou E Dominissini S Grossi S Sánchez-Ollé G Chabás A Pittis MG Filocamo M Vilageliu L Grinberg D 《Human mutation》2008,29(6):E58-E67
Gaucher disease is an autosomal recessive lysosomal storage disease that is mainly due to mutations in the GBA gene. Most of the mutant alleles described so far bear a single mutation. However, there are a few alleles bearing two or more DNA changes. It has been reported that patients homozygous for the [D409H;H255Q] double mutant allele (HGVS-approved nomenclature, p.[D448H;H294Q]) present a more severe phenotype than patients homozygous for the relatively common D409H mutation. In this study, we confirmed the detrimental cumulative effect of these two mutations at the enzymatic activity level by the heterologous expression of the single and double mutant alleles. Additionally, we found a high frequency of the [D409H;H255Q] allele in patients from the Balkans and the Adriatic area of Italy. This prompted us to perform a haplotype analysis, using five microsatellite polymorphisms close to the GBA gene, to determine the origin of this allele. The results of the 37 chromosomes analysed showed that most of them share a common haplotype and are consistent with a single origin in the Balkans and the Adriatic area of Italy for the [D409H;H255Q] allele. 相似文献
176.
177.
178.
E Skarmoutsou F D'Amico M Marchini G Malaponte R Scorza MC Mazzarino 《Human immunology》2012,73(9):950-953
A candidate gene for TIMP-1 gene located on the X-chromosome (rs4898) was selected for a control case study to investigate a possible association of this SNP with the susceptibility to systemic sclerosis and its digit ulcer manifestation. A total of 461 individuals of Italian Caucasian origin (228 SSc patients and 233 healthy control subjects) were genotyped for TIMP-1 +372 T/C single nucleotide polymorphism rs4898. Subgroups were analyzed according to the presence or absence of digital ulcers. The CC genotype and C allele frequencies were significantly lower in female SSc patients than in controls (OR 0.53, CI 0.29-0.96, p=0.03 and OR 0.72, CI 0.53-0.98 p=0.04, respectively). CC genotypes frequency was lower also in female patients with ulcers than those without ulcers (OR 0.37, CI 0.14-1.00, p=0.03). Furthermore, CC genotype and C allele frequencies were lower also in female patients with ulcers in comparison to female healthy control subjects (OR 0.27, CI 0.10-0.70, p=0.004; OR 0.60, CI 0.40-0.89, p=0.01, respectively). The TIMP-1 rs4898 polymorphism may play a protective role in the susceptibility to SSC in females, and in particular to digital ulcer formation. 相似文献
179.
180.
Lagiou A Samoli E Georgila C Zourna P Barbouni A Vassilarou D Tsikkinis A Sekeris CE Trichopoulos D Lagiou P 《Nutrition and cancer》2011,63(1):65-72
Estrogen receptor (ER) and/or progesterone receptor (PR) expression has been associated with more favorable breast cancer prognosis. Results on the differential association of diet with ER and/or PR positive and negative tumors have been inconclusive. In a large case-control study conducted in Athens, Greece, we investigated whether diet is associated with the expression of ER-alpha or PR in mammary tumors of 421 women with histologically confirmed breast cancer. Diet was assessed through an extensive food frequency questionnaire and results were analyzed using multiple logistic regression. After controlling for non-nutritional variables and mutually adjusting for energy-generating nutrients and ethanol, carbohydrate intake was inversely associated with ER-alpha (P = 0.04) and PR (P = 0.10) expression. The odds ratios (OR) per one standard deviation increment were 0.69 with 95% confidence interval (95% CI) 0.48-0.98 for ER-alpha and 0.72 (95% CI 0.49-1.07) for PR expression. No consistent or statistically significant associations were noted for any of the other energy-generating nutrients or food groups examined. Although in these data no strong relations of qualitative aspects of diet with hormone receptor expression in breast cancer tumors were evident, the inverse association of carbohydrate intake with ER-alpha, and perhaps PR, expression merits further study in future investigations. 相似文献