全文获取类型
收费全文 | 3079篇 |
免费 | 178篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 197篇 |
妇产科学 | 148篇 |
基础医学 | 263篇 |
口腔科学 | 68篇 |
临床医学 | 258篇 |
内科学 | 805篇 |
皮肤病学 | 73篇 |
神经病学 | 173篇 |
特种医学 | 236篇 |
外科学 | 467篇 |
综合类 | 134篇 |
一般理论 | 1篇 |
预防医学 | 90篇 |
眼科学 | 76篇 |
药学 | 122篇 |
中国医学 | 4篇 |
肿瘤学 | 104篇 |
出版年
2024年 | 2篇 |
2023年 | 34篇 |
2022年 | 48篇 |
2021年 | 85篇 |
2020年 | 66篇 |
2019年 | 72篇 |
2018年 | 86篇 |
2017年 | 75篇 |
2016年 | 122篇 |
2015年 | 135篇 |
2014年 | 161篇 |
2013年 | 158篇 |
2012年 | 211篇 |
2011年 | 145篇 |
2010年 | 139篇 |
2009年 | 131篇 |
2008年 | 178篇 |
2007年 | 212篇 |
2006年 | 174篇 |
2005年 | 168篇 |
2004年 | 136篇 |
2003年 | 118篇 |
2002年 | 94篇 |
2001年 | 65篇 |
2000年 | 49篇 |
1999年 | 53篇 |
1998年 | 53篇 |
1997年 | 44篇 |
1996年 | 37篇 |
1995年 | 22篇 |
1994年 | 29篇 |
1993年 | 23篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 6篇 |
1989年 | 14篇 |
1988年 | 12篇 |
1987年 | 25篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 8篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1967年 | 1篇 |
排序方式: 共有3287条查询结果,搜索用时 15 毫秒
91.
92.
93.
Gecit I Aslan M Gunes M Pirincci N Esen R Demir H Ceylan K 《Journal of cancer research and clinical oncology》2012,138(5):739-743
Objectives
Prolidase is a member of the matrix metalloproteinase family. It plays a major role in collagen turnover, matrix remodeling and cell growth. Nitric oxide (NO) regulates many processes such as collagen synthesis and matrix remodeling. Thus, NO may augment angiogenesis, tumor invasion, and metastasis. The aim of this study was to investigate total antioxidant status (TAS), malondialdehyde (MDA) and NO levels in patients with bladder cancer and to determine their relationship with prolidase activity.Design and methods
Thirty-five patients with bladder cancer and 32 controls were enrolled. Serum TAS, MDA, prolidase activity and NO levels were determined.Results
Serum prolidase activity, NO levels and MDA levels were significantly higher in bladder cancer than controls (all, P < 0.05), while TAS levels were significantly lower (P < 0.05).Conclusions
Our results show that increased prolidase seems to be associated with increased NO levels and oxidative stress along with decreased antioxidant levels in bladder cancer.94.
95.
Bulent Demir Ilker Murat Caglar Ismail Ungan Murat Ugurlucan Hande Oktay Tureli Osman Karakaya 《Archives of Medical Science》2013,9(6):1055-1061
Introduction
Platelets play a major role in thromboembolic events. Increased mean platelet volume (MPV) indicates higher platelet reactivity and also a tendency to thrombosis. Patent foramen ovale (PFO), persistence of the fetal anatomic shunt between right and left atria, is strongly associated with cryptogenic stroke. The aim of this study is to determine the relationship between MPV and PFO and if such an association exists, whether higher MPV levels may require antiplatelet therapy before a thromboembolic event happens, together with a literature review.Material and methods
Thirty patients (15 women, 15 men), free of any cerebrovascular events, were diagnosed with PFO by transesophageal echocardiography (TEE), enrolled as the study group. Thirty consecutive patients (16 women and 14 men), who were diagnosed as normal in TEE, were enrolled as the control group. These two groups were compared according to MPV and anatomical features of the right atrium.Results
There was no significant difference between study and control groups in clinical features and also no difference was observed in platelet counts; however, MPV in the PFO group was significantly higher than the control group (8.38 ±0.93 fl and 7.45 ±0.68 fl respectively).Conclusions
Our results indicate that elevated MPV may be detected in patients with PFO. This might be one of the explanations for the relationship between PFO and cryptogenic stroke; however, larger cohorts are warranted in order to define further mechanisms. 相似文献96.
AS Winkler K Friedrich S Velicheti J Dharsee R K?nig A Nassri M Meindl A Kidunda TH Müller L Jilek-Aall W Matuja T Gotwald E Schmutzhard 《African health sciences》2013,13(2):529-540
Background
Onchocerciasis has been implicated in the pathogenesis of epilepsy. The debate on a potential causal relationship between Onchocerca volvulus and epilepsy has taken a new direction in the light of the most recent epidemic of nodding syndrome.Objective
To document MRI changes in people with different types of epilepsy and investigate whether there is an association with O. volvulus infection.Methods
In a prospective study in southern Tanzania, an area endemic for O. volvulus with a high prevalence of epilepsy and nodding syndrome, we performed MRI on 32 people with epilepsy, 12 of which suffered from nodding syndrome. Polymerase chain reaction (PCR) of O. volvulus was performed in skin and CSF.Results
The most frequent abnormalities seen on MRI was atrophy (twelve patients (37.5%)) followed by intraparenchymal pathologies such as changes in the hippocampus (nine patients (28.1%)), gliotic lesions (six patients (18.8%)) and subcortical signal abnormalities (three patients (9.4%)). There was an overall trend towards an association of intraparenchymal cerebral pathologies and infection with O. volvulus based on skin PCR (Fisher''s Exact Test p=0.067) which was most pronounced in children and adolescents with nodding syndrome compared to those with other types of epilepsy (Fisher''s Exact Test, p=0.083). Contrary to skin PCR results, PCR of CSF was negative in all patients.Conclusion
The observed trend towards an association of intraparenchymal cerebral pathological results on MRI and a positive skin PCR for O. volvulus despite negative PCR of CSF is intriguing and deserves further attention. 相似文献97.
An investigation was carried out on equal-channel angular pressing (ECAP) and extrusion processing of a ZM21 Mg alloy to obtain an improved candidate material for the manufacturing of biodegradable Mg stents. Ultrafine-grain size billets of the ZM21 alloy were obtained by two-stage ECAP aimed at achieving an initial refining of the structure at 200 °C and then reaching the submicrometer grain size range by lowering the processing temperature down to 150 °C. The investigation revealed a significant improvement in the properties of the ECAP-treated samples compared with the starting coarse-grained ZM21 alloy. The 0.2% yield strength rose from 180 to 340 MPa after 150 °C ECAP processing, while maintaining a fairly high tensile ductility. The ultrafine ZM21 alloy billets were then used for the extrusion of stent precursors having the form of small-size tubes. The grain size after extrusion remained in the submicrometer range while the hardness was revealed to be significantly higher than that of the coarse-grained ZM21 Mg alloy. It was demonstrated that processing of biodegradable Mg stent having an ultrafine-grained microstructure by ECAP and low-temperature extrusion is feasible and that the obtained products feature promising properties. 相似文献
98.
99.
Aytekin E Caglar NS Ozgonenel L Tutun S Demiryontar DY Demir SE 《Clinical rheumatology》2012,31(1):91-97
The home-based exercise therapy recommended to the patients with ankylosing spondylitis (AS) is a simply applicable and cheap
method. The aim of this study was to investigate the effects of home-based exercise therapy on pain, mobility, function, disease
activity, quality of life, and respiratory functions in patients with AS. Eighty patients diagnosed with AS according to the
modified New York criteria were included in the study. Home-based exercise program including range of motion, stretching,
strengthening, posture, and respiratory exercises was practically demonstrated by a physiotherapist. A training and exercise
manual booklet was given to all patients. Patients following home-based exercise program five times a week at least 30 min
per session (exercise group) for 3 months were compared with those exercising less than five times a week (control group).
Visual analog scale pain (VASp) values at baseline were significantly higher in the exercise group. The exercise group showed
improvements in VASp, tragus–wall distance, morning stiffness, finger–floor distance, modified Schober's test, chest expansion,
the Bath Ankylosing Spondylitis Disease Activity Index, the Bath Ankylosing Spondylitis Functional Index, Ankylosing Spondylitis
Quality of Life Questionnaire (ASQoL), forced expiratory volume in first second, and forced vital capacity at third month.
There was significant difference in ASQoL scores between the two groups in favor of the exercise group at third month. Regular
home-based exercise therapy should be a part of main therapy in patients with AS. Physicians should recommend that patients
with AS do exercise at least five times a week at least 30 min per session. 相似文献
100.
Orüm H Pamuk GE Pamuk ON Demir M Turgut B 《Journal of thrombosis and thrombolysis》2012,33(2):154-159
Recently, it has been reported that ankylosing spondylitis (AS) was characterised by endothelial dysfunction and the development
of atherosclerotic complications. In this study, we evaluated platelet and endothelial activation parameters in AS patients.
Fiftynine AS patients and 22 healthy controls were included. The clinical features and acute phase parameters were evaluated.
In all patients and healthy controls, platelet-monocyte complexes (PMC), platelet-neutrophil complexes, basal and ADP-stimulated
P-selectin (CD62P) expression were determined by flow cytometry; soluble E-selectin (sE-selectin) and soluble CD40L (sCD40L)
were determined by ELISA. AS patients were divided into two groups as active and inactive by using BASDAI. In 15 AS patients,
the evaluated parameters were assessed before and after 12 weeks of anti-TNF therapy. PMC and sCD40L levels in AS patients
were significantly higher than in the control group (P values 0.013 and 0.016). The evaluated variables were similar in active and inactive AS groups (P > 0.05). There were no significant changes in platelet and endothelial activation parameters in AS patients after anti-TNF
therapy (P > 0.05). Platelet activation which is reflected by high levels of PMC and sCD40L might be responsible for the increased frequency
of atherosclerosis in AS. The platelet activation in our AS patients was not associated with disease activity and did not
improve after anti-TNF therapy. 相似文献