全文获取类型
收费全文 | 1088篇 |
免费 | 41篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 27篇 |
妇产科学 | 18篇 |
基础医学 | 97篇 |
口腔科学 | 64篇 |
临床医学 | 107篇 |
内科学 | 220篇 |
皮肤病学 | 34篇 |
神经病学 | 77篇 |
特种医学 | 46篇 |
外科学 | 162篇 |
综合类 | 31篇 |
预防医学 | 56篇 |
眼科学 | 15篇 |
药学 | 104篇 |
中国医学 | 4篇 |
肿瘤学 | 67篇 |
出版年
2023年 | 16篇 |
2022年 | 46篇 |
2021年 | 71篇 |
2020年 | 34篇 |
2019年 | 47篇 |
2018年 | 58篇 |
2017年 | 30篇 |
2016年 | 38篇 |
2015年 | 43篇 |
2014年 | 37篇 |
2013年 | 64篇 |
2012年 | 69篇 |
2011年 | 82篇 |
2010年 | 30篇 |
2009年 | 35篇 |
2008年 | 55篇 |
2007年 | 70篇 |
2006年 | 48篇 |
2005年 | 68篇 |
2004年 | 51篇 |
2003年 | 41篇 |
2002年 | 48篇 |
2001年 | 4篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1968年 | 1篇 |
1961年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有1139条查询结果,搜索用时 23 毫秒
21.
This study investigated the effect of Ankaferd Blood Stopper (ABS) contamination on bond strength of total- and self-etching systems. Seventy mandibular third molars sectioned in a mesio-distal direction were mounted in acrylic resin, and flat dentin surfaces were exposed. The specimens were randomly assigned to seven groups (n=20), according to the surface treatment: Group I, ABS contamination+37% phosphoric acid+Solobond M; Group II, ABS contamination+Clearfil SE Bond; Group III, ABS contamination+All Bond SE; Group VI, 37% phosphoric acid+ABS contamination+Solobond M; Group V, Solobond M; Group VI, Clearfil SE Bond; and Group VII, All Bond SE. Next, a resin composite (Grandio) was built up using a plastic apparatus and polymerized. The specimens were tested in shear mode at a crosshead speed of 1 mm/min. There were significant differences in bond strengths between the control and ABS-contaminated samples. These findings suggest that ABS contamination reduced bond strength of total- and self-etching adhesives. 相似文献
22.
23.
24.
Ismail Bozkurt Yasar Ozturk Guven Guney Burak Arslan Ozlem Gulbahar Yahya Guvenc Salim Senturk Mesut Emre Yaman 《International journal of clinical and experimental pathology》2022,15(1):20
Traumatic brain injury (TBI) continues to be a significant public healthcare concern. Neuroinflammation that occurs in the secondary phase of TBI leads to cognitive and physical dysfunction. A number of therapeutic modalities have been evaluated in an attempt to find a suitable treatment. The only drug approved for the treatment of idiopathic pulmonary fibrosis, pirfenidone, has been evaluated for its antifibrotic, anti-inflammatory, and anti-oxidant properties for various disorders, but this is the first study to examine its effects in an experimental TBI model. Twenty-four Wistar rats were randomly divided into three groups: control, trauma, and pirfenidone. The two latter groups underwent experimental diffuse cortical injury mimicking TBI. Neurological assessment was performed using the Garcia test, histological analysis was performed to examine neuroprotective and anti-inflammatory effects, and biochemical analyses of neuron-specific enolase (NSE), S-100B, caspase-3, and thiobarbituric acid reactive substances were performed. The pirfenidone group had a better Garcia test score (P=0.001), an increased anti-inflammatory effect (P<0.001), and an enhanced neuroprotective effect (P=0.007) along with decreased NSE, S100B, and TBARS levels compared to the trauma group. However, pirfenidone did not show a beneficial effect on caspase-3 levels. Pirfenidone may help decrease mortality and morbidity rates after TBI through its anti-inflammatory and antioxidant effects. 相似文献
25.
A facile two-step strategy has been reported for the preparation of a ternary 3D reduced graphene oxide/Ni0.5Zn0.5Fe2O4/polyindole nanocomposite (GNP) and this composite is applied as an electrode material for supercapacitor applications. Remarkably, Ni0.5Zn0.5Fe2O4 nanoparticles (NZF) decorated on reduced graphene oxide (GN2) are achieved by a facile hydrothermal method followed by coating with polyindole (PIN) through an in situ emulsion polymerization process. The structure, porosity, morphology, and thermal stability of the resulting ternary GNP hybrid material were characterized via X-ray diffraction (XRD), Raman spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurements, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). This combination of hybrid material has a favorable mesoporous structure that enables high exposure of active sites for fast electron transport for supercapacitor applications. We demonstrate here that the ternary GNP hybrid electrode material is capable of delivering a favorable specific capacitance of ∼320 F g−1 at 0.3 A g−1 within the potential range from −0.1 to 1 V, with desirable rate stability and excellent cycling stability in the three-electrode system. Furthermore, an asymmetric supercapacitor (ASC) of a two-electrode configuration was fabricated using 3D RGO and GNP as the negative and positive electrodes, respectively. Such a device manifests a favourable Csp of 48.9 F g−1 at 0.5 A g−1 and retains stability of 84% even after 2000 cycles. This ASC device exhibits a significant energy density of 16.38 W h kg−1 at a power density of 1784 W kg−1. The synergistic effects of pseudo and double layer capacitive contributions from PIN and GN2 make this ternary GNP hybrid electrode material of great promise in supercapacitor applications.A facile two-step strategy has been reported for the preparation of a ternary 3D reduced graphene oxide/Ni0.5Zn0.5Fe2O4/polyindole nanocomposite (GNP) and this composite is applied as an electrode material for supercapacitor applications. 相似文献
26.
27.
28.
Serefhanoglu S Buyukasik Y Emmungil H Sayinalp N Haznedaroglu IC Goker H Aksu S Ozcebe OI 《International journal of medical sciences》2010,8(1):30-38
Iron deficiency anemia (IDA) is a frequent disorder. Also, it may be a sign of underlying serious diseases. Iron deficiency points to an occult or frank bleeding lesion when occurred in men or postmenopausal women. In this study, we aimed to evaluate the diagnostic yield of endoscopy in patients with IDA and to define predictive factors of gastrointestinal (GI) lesions causing IDA. Ninety-one patients (77 women, 14 men; mean age: 43 years) who were decided to have esophago-duodenoscopy and/or colonoscopy for iron deficiency anemia were interviewed and responded to a questionnaire that included clinical and biochemical variables. The endoscopic findings were recorded as GI lesions causing IDA or not causing IDA. Endoscopy revealed a source of IDA in 18.6 % of cases. The risk factors for finding GI lesions causing IDA were as follows: male gender (p= 0.004), advanced age (> 50 years) (p= 0.010), weight loss (over 20% of total body weight lost in last 6 month) (p= 0.020), chronic diarrhea (p= 0.006), change of bowel habits (p= 0.043), epigastric tenderness (p= 0.037), raised carcinoembryonic antigen (CEA) level (normal range: 0-7 ng/mL) (p= 0.039), < 10 gr/dl hemoglobin (Hb) level (p=0.054). None of these risk factors had been present in 21 (23%) women younger than 51 years. In this group, no patient had any GI lesion likely to cause IDA (negative predictive value= 100%). In multivariate analysis, advanced age (p=0.017), male gender (p< 0.01) and weight lost (p=0.012) found that associated with GI lesions in all patients. It may be an appropriate clinical approach to consider these risk factors when deciding for gastrointestinal endoscopic evaluation in iron deficiency anemia. 相似文献
29.
Neda Sepahi Athar Rasekh Jahromi Yahya Daneshbod Elahe Nimi Hoveidi 《Gynecological endocrinology》2017,33(6):429-432
microRNAs (miRNAs) are negative regulators in a variety of cellular processes that occur in endometriosis. Therefore, functional polymorphisms in miRNA and miRNA binding sites may affect gene expression and contribute to susceptibility of endometriosis. In this study, we evaluated the association of two miRNA related polymorphisms, mir-126 rs4636297 and TGFβRI rs334348, with endometriosis risk and its severity. This case-control study was done on 157 endometriosis patients and 252 healthy women as a control group. Tetra amplification refractory mutation system-polymerase chain reaction (tetra-ARMS PCR) was designed to determine the polymorphisms. Our finding showed significant differences in genotype frequency of mir-126 rs4636297 between the groups (χ2?=?6.26, p?=?0.044). A significant protection against endometriosis was found for mir-126 rs4636297 in allele (G versus A allele: OR?=?0.695, 95% CI?=?0.519–0.931, p?=?0.015) and genotype (GG versus AA genotype: OR?=?0.451, 95%CI?=?0.233–0.873, p?=?0.018). Significant association was also observed between the A allele and severity of endometriosis (OR?=?0.478, 95%CI?=?0.297–0.768, p?=?0.002). Moreover, we found a significant association between AA genotype with the risk of endometriosis (OR?=?0.493, 95%CI?=?0.250–0.970, p?=?0.041) and its severity (OR?=?0.240, 95%CI?=?0.065–0.883, p?=?0.032) regarding TGFβRI rs334348 polymorphism. These finding suggest that, for the first time, mir-126 rs4636297 and TGFβRI rs334348 polymorphisms may influence individual’s susceptibility to endometriosis and its severity. 相似文献
30.
H. Yasemin BALABAN Abdullah Tark ASLAN efika AYAR Osman DA Alpaslan ALP Cem MEK Cavanir VAHABOV Tolga YILDIRIM Hakan G
KER Yahya BÜYÜKAIK Halis MEK 《Turkish Journal of Medical Sciences》2021,51(3):1229
Background/aim Hepatitis B virus (HBV) vaccination rates are insufficient in high-risk patients worldwide. This study aimed to investigate the screening, immunization, and vaccination rates in three high-risk groups for HBV infection: allogeneic hematopoietic stem cell transplantation (AHSCT), renal transplantation (RT), and chronic hepatitis C (CHC) groups. Materials and methods The serological data of consecutive patients between 2014 and 2019 were reviewed using the hospital database. Results The HBV screening rates were 100.0%, 90.4%, and 82.4% in the AHSCT, CHC, and RT groups, respectively (p = 0.003). The immunization rates against HBV through either previous exposure or vaccination were 79.5%, 71.7%, and 46.5% in the AHSCT, RT, and CHC groups, respectively (p < 0.001). The HBV vaccination rate was significantly low in the CHC group (71.5%, 69.0%, 34.6% in the AHSCT, RT, and CHC groups, respectively, p < 0.001). If patients lost their immunity due to immunosuppressive therapy were accounted, the vaccination rates increased to 95.2% in the AHSCT group and 72.9% in the RT group. The rate of annual screening for HBV status was 97.9% in the AHSCT group, but it was only 23.9% in the RT group. Conclusion HBV screening and vaccination rates were significantly lower in the RT and CHC groups than in the AHSCT group. 相似文献