全文获取类型
收费全文 | 723篇 |
免费 | 72篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 17篇 |
妇产科学 | 15篇 |
基础医学 | 76篇 |
口腔科学 | 58篇 |
临床医学 | 82篇 |
内科学 | 106篇 |
皮肤病学 | 48篇 |
神经病学 | 72篇 |
特种医学 | 23篇 |
外科学 | 149篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 29篇 |
眼科学 | 12篇 |
药学 | 54篇 |
中国医学 | 4篇 |
肿瘤学 | 37篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 26篇 |
2021年 | 38篇 |
2020年 | 22篇 |
2019年 | 46篇 |
2018年 | 52篇 |
2017年 | 33篇 |
2016年 | 34篇 |
2015年 | 24篇 |
2014年 | 41篇 |
2013年 | 52篇 |
2012年 | 61篇 |
2011年 | 67篇 |
2010年 | 47篇 |
2009年 | 34篇 |
2008年 | 46篇 |
2007年 | 35篇 |
2006年 | 28篇 |
2005年 | 25篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1980年 | 2篇 |
1973年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有798条查询结果,搜索用时 15 毫秒
1.
David Simon Koray Tascilar Sara Unbehend Sara Bayat Andreas Berlin Anna-Maria Liphardt Timo Meinderink Juergen Rech Axel J Hueber Georg Schett Arnd Kleyer 《Journal of bone and mineral research》2020,35(9):1695-1702
The impact of primary hand osteoarthritis (HOA) on bone mass, microstructure, and biomechanics in the affected skeletal regions is largely unknown. HOA patients and healthy controls (HCs) underwent high-resolution peripheral quantitative computed tomography (HR-pQCT). We measured total, trabecular, and cortical volumetric bone mineral densities (vBMDs), microstructural attributes, and performed micro–finite element analysis for bone strength. Failure load and scaled multivariate outcome matrices from distal radius and second metacarpal (MCP2) head measurements were analyzed using multiple linear regression adjusting for age, sex, and functional status and reported as adjusted Z-score differences for total and direct effects. A total of 105 subjects were included (76 HC: 46 women, 30 men; 29 HOA: 23 women, six men). After adjustment, HOA was associated with significant changes in the multivariate outcome matrix from the MCP2 head (p < .001) (explained by an increase in cortical vBMD (Δz = 1.07, p = .02) and reduction in the trabecular vBMD (Δz = −0.07, p = .09). Distal radius analysis did not show an overall effect of HOA; however, there was a gender-study group interaction (p = .044) explained by reduced trabecular vBMD in males (Δz = −1.23, p = .02). HOA was associated with lower failure load (−514 N; 95%CI, −1018 to −9; p = 0.05) apparent in males after adjustment for functional status. HOA is associated with reduced trabecular and increased cortical vBMD in the MCP2 head and a reduction in radial trabecular vBMD and bone strength in males. Further investigations of gender-specific changes of bone architecture in HOA are warranted. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research. 相似文献
2.
Monfraix S Bayat S Porra L Berruyer G Nemoz C Thomlinson W Suortti P Sovijärvi AR 《Physics in medicine and biology》2005,50(1):1-11
The aim of this study was to assess the feasibility of a novel respiration-gated spiral synchrotron radiation computed tomography (SRCT) technique for direct quantification of absolute regional lung volumes, using stable xenon (Xe) gas as an inhaled indicator. Spiral SRCT with K-edge subtraction using two monochromatic x-ray beams was used to visualize and directly quantify inhaled Xe concentrations and airspace volumes in three-dimensional (3D) reconstructed lung images. Volume measurements were validated using a hollow Xe-filled phantom. Spiral images spanning 49 mm in lung height were acquired following 60 breaths of an 80% Xe-20% O2 gas mixture, in two anaesthetized and mechanically ventilated rabbits at baseline and after histamine aerosol inhalation. Volumetric images of 20 mm lung sections were obtained at functional residual capacity (FRC) and at end-inspiration. 3D images showed large patchy filling defects in peripheral airways and alveoli following histamine provocation. Local specific lung compliance was calculated based on FRC/end-inspiration images in normal lung. This study demonstrates spiral SRCT as a new technique for direct determination of regional lung volume, offering possibilities for non-invasive investigation of regional lung function and mechanics, with a uniquely high spatial resolution. An example of non-uniform volume distribution in rabbit lung following histamine inhalation is presented. 相似文献
3.
Elaheh Foroumandi Roghayeh Javan Leili Moayed Hossein Fahimi Fereshteh Kheirabadi Mahboubeh Neamatshahi Fazeleh Shogofteh Azam Zarghi 《Phytotherapy research : PTR》2023,37(1):285-294
The aim of the current randomized control trial (RCT) study was to investigate the effects of fenugreek seed extract on memory, depression, quality of life, blood pressure, and serum malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in adult AD patients. This randomized clinical trial was conducted in geriatric homes in Iran. The study participants included 82 AD patients with mild-to-moderate memory deficit. Patients in the intervention group received 5 cc of fenugreek seed extract for 4 months and subjects in the control group received a placebo. Memory, depression, quality of life, and BP levels, as well as serum MDA and TAC, were assessed before and after the intervention. There was a significant increase in serum levels of TAC (p < 0.001) and a reduction in serum MDA status (p < 0.001) after 4 months of fenugreek seed extract supplementation. In addition, increasing levels of memory (p < 0.001) and quality of life (p < 0.001), as well as reduction of depression (p = 0.002), systolic BP (p < 0.001), and diastolic BP (p < 0.001) levels were detected in the intervention group compared with baseline. Fenugreek seed extract supplementation in AD patients shows promising positive effects on memory, quality of life, BP, and selective oxidative indices levels. 相似文献
4.
Cécile Couchoud Florian Bayer Muriel Rabilloud Carole Ayav Sahar Bayat Clemence Bechade Philippe Brunet Sebastien Gomis Emilie Savoye Olivier Moranne Thierry Lobbedez Rene Ecochard the REIN registry 《American journal of transplantation》2021,21(11):3608-3617
Despite national guidelines, medical practices and kidney transplant waiting list registration policies may differ from one dialysis/transplant unit to another. Benefit risk assessment variations, especially for elderly patients, have also been described. The aim of this study was to identify sources of variation in early kidney transplant waiting list registration in France. Among 16 842 incident patients during the period 2016–2017, 4386 were registered on the kidney transplant waiting list at the start of, or during the first year after starting, dialysis (26%). We developed various log-linear mixed effect regression models on three levels: patients, dialysis networks, and transplant centers. Variability was expressed as variance from the random intercepts (± standard error). Although patient characteristics have an important impact on the likelihood of registration, the overall magnitude of variability in registration was low and shared by dialysis networks and transplant centers. Between-transplant center variability (0.23 ± 0.08) was 1.8 higher than between-dialysis network variability (0.13 ± 0.004). Older age was associated with a lower probability of registration and greater variability between networks (0.04, 0.20, & 0.93 in the 18–64, 65–74, and 75–84 age groups). Targeted interventions should focus on elderly patients and/or certain regions with greater variability in waiting list access. 相似文献
5.
Promonet C Anglade D Menaouar A Bayat S Durand M Eberhard A Grimbert FA 《Anesthesiology》2000,92(1):208-218
BACKGROUND: Distortion of the pressure wave by a liquid-filled catheter-transducer system leads most often to an overestimation in systolic arterial blood pressure in pulmonary and systemic circulations. The pressure distortion depends on the catheter-transducer frequency response. Many monitoring systems use either mechanical or electronic filters to reduce this distortion. Such filters assume, however, that the catheter-transducer frequency response does not change over time. The current study aimed to study the changes with time of the catheter-transducer frequency response and design a flush procedure to reverse these changes back to baseline. METHODS: An in vitro setup was devised to assess the catheter-transducer frequency response in conditions approximating some of those met in a clinical environment (slow flushing, 37 degrees C, 48-h test). Several flush protocols were assessed. RESULTS: Within 48 h, catheter-transducer natural frequency decreased from 17.89 +/- 0.36 (mean +/- SD) to 7.35 +/- 0.25 Hz, and the catheter-transducer damping coefficient increased from 0.234 +/- 0.004 to 0.356 +/- 0.010. Slow and rapid flushing by the flush device built into the pressure transducer did not correct these changes, which were reversed only by manual fast flush of the transducer and of the catheter. These changes and parallel changes in catheter-transducer compliance may be explained by bubbles inside the catheter-transducer. CONCLUSIONS: Catheter-transducer-induced blood pressure distortion changes with time. This change may be reversed by a manual fast flush or "rocket flush" procedure, allowing a con. stant correction by a filter. 相似文献
6.
7.
Fereshteh Asgari Akbar Biglarian Behjat Seifi Andisheh Bakhshi Hamid Heidarian Miri Enayatollah Bakhshi 《Annals of epidemiology》2013,23(9):534-538
PurposeThe last study that had a representative sample of the Iranian population and examined the association between sociodemographic and lifestyle factors with obesity used data from the 1999 to 2000 National Health Survey in Iran. Concern about the increased prevalence of obesity has heightened interest in the association between varieties of these factors with obesity among Iranian households.MethodsData (20,917 adults) were taken from the 2009 STEPwise approach to Surveillance survey in Iran that was conducted under the supervision of World Health Organization. Using quadratic inference function, we evaluated the relation of age, sex, physical activity, serving of fruit and vegetable, employment status, smoking, and place of residence with obesity.ResultsUsing 20–30 years as the reference group, the obesity odds ratios (ORs) were 2.48, 3.79, 3.52, and 3.15 for ages 30–40, 40–50, 50–60, and 60+ years, respectively. Obesity OR for female was 2.63, compared with male. Obesity ORs for smokers and ex-smokers were 0.64 and 1.18, respectively, compared with nonsmokers. Among Iranian adult, obesity ORs for the moderate and vigorous physical activity were 0.99 and 0.90, respectively, compared with low level. The estimated odds of obesity were 46% higher for rural adults. Obesity ORs for public and private employed were 0.79 and 0.76, respectively, compared with unemployed.ConclusionsOur results may provide better insights of the factors associated with obesity and can be used as a basis to reinforce health programs to prevent obesity in Iran. 相似文献
8.
Nima Hafezi-Nejad Mohsen Khosravi Nooshin Bayat Ariana Kariminejad Valeh Hadavi Christian Oberkanins 《Hemoglobin》2014,38(3):153-157
Our study aimed to determine the number of couples with normal hemoglobin (Hb) electrophoresis and low-borderline hematological values, which may come up with a clinically critical status in their offspring. The number of couples at risk for severe α-thalassemia (α-thal) needed to be estimated before recommending genetic counseling and prenatal diagnosis (PND). During the past 14 years, from at least 7000 referrals, 754 couples were investigated for α-thal by direct mutation detection methods followed by reverse strip assay and α-globin gene sequencing for inconclusive cases. Detection of silent β-thalassemia (β-thal) mutations was done in suspected cases by complete β-globin gene sequencing. We were able to provide a molecular diagnosis in 87.3% (658/754) of couples. A total of 9.1% (60/658) may have a clinically significant hemoglobinopathy in their offspring. Significant conditions included hydrops fetalis (20.0%; 12/60), certain Hb H (β4) genotypes (78.3%; 47/60) and β-thal intermedia (β-TI) (1.7%; 1/60). The diagnostic flowchart for couples with microcytic hypochromic anemia in countries with a high prevalence of hemoglobinopathies should include α and β gene sequencing. As our results indicate, every nine out of 100 of these couples will face significant hemoglobinopathies and every two out of 100 can carry Hb Bart’s (γ4) hydrops fetalis in their pregnancies. For such cases, PND should be utilized to allow the carrier couples to decide whether or not to abort the fetus. 相似文献
9.
Keloid disease (KD) is a fibroproliferative disorder characterised partly by an altered extracellular matrix (ECM) profile. In fetal scarring, hyaluronic acid (HA) expression is increased, but is reduced in KD tissue compared with normal skin (NS). The expression of Hyaluronan Synthase (HAS) and hyaluronidase (HYAL) in KD and NS tissue were investigated for the first time using a range of techniques. Hyaluronan synthase and HYAL mRNA expression were significantly increased in NS tissue compared with KD tissue (P < 0.05). Immunohistological analysis of tissue indicated an accumulation of HAS and HYAL protein expression in KD compared with NS due to the thicker epidermis. No differences were observed in mRNA or protein expression in KD and NS fibroblasts. Reduced expression of HAS and HYAL may alter HA synthesis, degradation and accumulation in KD. Better understanding of the role of HA in KD may lead to novel therapeutic approaches to address the resulting ECM imbalance. 相似文献
10.