全文获取类型
收费全文 | 5412篇 |
免费 | 316篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 93篇 |
妇产科学 | 277篇 |
基础医学 | 563篇 |
口腔科学 | 92篇 |
临床医学 | 557篇 |
内科学 | 1202篇 |
皮肤病学 | 59篇 |
神经病学 | 413篇 |
特种医学 | 177篇 |
外科学 | 681篇 |
综合类 | 96篇 |
一般理论 | 2篇 |
预防医学 | 250篇 |
眼科学 | 304篇 |
药学 | 466篇 |
中国医学 | 30篇 |
肿瘤学 | 467篇 |
出版年
2023年 | 26篇 |
2022年 | 74篇 |
2021年 | 155篇 |
2020年 | 60篇 |
2019年 | 118篇 |
2018年 | 165篇 |
2017年 | 100篇 |
2016年 | 120篇 |
2015年 | 160篇 |
2014年 | 199篇 |
2013年 | 257篇 |
2012年 | 416篇 |
2011年 | 383篇 |
2010年 | 287篇 |
2009年 | 217篇 |
2008年 | 308篇 |
2007年 | 326篇 |
2006年 | 328篇 |
2005年 | 283篇 |
2004年 | 244篇 |
2003年 | 210篇 |
2002年 | 191篇 |
2001年 | 166篇 |
2000年 | 161篇 |
1999年 | 132篇 |
1998年 | 27篇 |
1997年 | 38篇 |
1996年 | 27篇 |
1995年 | 26篇 |
1994年 | 25篇 |
1993年 | 14篇 |
1992年 | 79篇 |
1991年 | 55篇 |
1990年 | 66篇 |
1989年 | 40篇 |
1988年 | 27篇 |
1987年 | 39篇 |
1986年 | 27篇 |
1985年 | 26篇 |
1984年 | 18篇 |
1983年 | 9篇 |
1981年 | 9篇 |
1980年 | 16篇 |
1979年 | 20篇 |
1978年 | 16篇 |
1977年 | 9篇 |
1975年 | 10篇 |
1973年 | 8篇 |
1972年 | 12篇 |
1971年 | 8篇 |
排序方式: 共有5780条查询结果,搜索用时 15 毫秒
81.
Context Oxidative stress plays a key role in neurodegenerative disorders, including Parkinson’s disease (PD). Rice fermented with Monascus purpureus Went (Monascaceae) NTU 568 (red mould rice) was found to contain antioxidants, including dimerumic acid (DMA) and deferricoprogen (DFC).Objective The effects of DMA and DFC on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity and potential protective mechanisms in differentiated PC-12 pheochromocytoma cells were investigated.Materials and methods DMA (0–60?μM) or DFC (0–10?μM) was co-treated with 6-OHDA (200?μM, 24?h exposure) in differentiated PC-12 cells. Cell viability and intercellular reactive oxygen species (ROS) were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2′,7′-dichlorofluorescein-diacetate (DCFH-DA) assays, respectively. Cell apoptosis was determined by DNA fragmentation analysis and propidium iodide staining by flow cytometry. Western blot analysis was used to measure the levels of cell protein expression.Results DMA and DFC significantly increased cell viability to 72% and 81% in 6-OHDA-induced differentiated PC-12 cell cultures, respectively. Furthermore, DMA and DFC reduced 6-OHDA-induced formation of extracellular and intercellular ROS by 25% and 20%, respectively, and decreased NADPH oxidase-2 expression in differentiated PC-12 cells. DMA and DFC inhibited 6-OHDA-induced apoptosis and decreased activation of caspase-3 via regulation of Bcl-2-associated X protein (Bax) and Bcl-2 protein expression in differentiated PC-12 cells.Conclusion DMA and DFC may protect against 6-OHDA toxicity by inhibiting ROS formation and apoptosis. These results showed that the metabolites from M. purpureus NTU 568 fermentation were potential therapeutic agents for PD induced by oxidative damage and should be encouraged for further research. 相似文献
82.
Real‐world effectiveness and safety of paritaprevir/ritonavir,ombitasvir, and dasabuvir with or without ribavirin for patients with chronic hepatitis C virus genotype 1b infection in Taiwan 下载免费PDF全文
83.
Ping-Tao Tseng Hung-Yu Wang Yu-Shian Cheng Feng-Chih Shen Pao-Yen Lin Ching-Kuan Wu 《The Kaohsiung journal of medical sciences》2014,30(11):579-586
The prevalence rate of metabolic syndrome (MS) and coronary artery disease (CAD) has been found to be high in patients with chronic schizophrenia. Current evidence shows that CAD is underdiagnosed in this group. Our study evaluated the prevalence of MS and the risk of CAD in patients with chronic schizophrenia in a chronic care mental hospital in southern Taiwan. We included all patients with the diagnosis of schizophrenia or schizoaffective disorder. We collected all laboratory, physical examination, psychiatric interview, and chart review data. We also evaluated the risk of CAD in these patients using the Framingham point system. There was no significant age difference in the MS prevalence rate in these patients. The young patients with schizophrenia in our study tended to have a higher prevalence of MS than the general population. In addition, female patients had a higher prevalence rate of MS than males. Based on the Framingham point system, we found the 10-year risk of CAD to be higher among the patients with schizophrenia than in the general population. Our study highlights the importance of the high risk of MS in both younger and older patients with schizophrenia, without a significant relationship to the use of antipsychotics. More complete cohort studies are needed to confirm these findings. Psychiatrists may want to establish more specific and detailed clinical guidelines for patients with chronic schizophrenia with comorbid physical diseases, especially MS and CAD. 相似文献
84.
85.
Follistatin is a glycoprotein with various biologic functions that plays a role in adipocyte differentiation, muscle stimulation, anti-inflammation, and energy homeostasis. Thyroid hormones influence energy expenditure, glucose, and lipid metabolism. The association between serum follistatin level and thyroid function statuses has seldom been evaluated.The objectives of this study were to compare serum follistatin concentrations in different thyroid function statuses and to evaluate the associations between serum follistatin and free thyroxine (fT4) levels.In this study, 30 patients with hyperthyroidism (HY group) and 30 euthyroid individuals (EU group) were recruited. The patients of HY group were treated with antithyroid regimens as clinically indicated, whereas no medication was given to EU group. The demographic and anthropometric characteristics, biochemical data, serum levels of follistatin, and thyroid function of both groups at baseline and at the 6th month were compared. Data of all patients were pooled for the analysis of the associations between the levels of follistatin and fT4.At baseline, the HY group had significantly higher serum follistatin levels than the EU group (median [Q1, Q3]: 1.81 [1.33, 2.78] vs 1.13 [0.39, 1.45] ng/mL, P < 0.001). When treated with antithyroid regimens, the follistatin serum levels in HY group decreased to 1.54 [1.00, 1.88] ng/mL at the 6th month. In all patients, the serum levels of follistatin were positively associated with fT4 levels at baseline (β = 0.54, P = 0.005) and at the 6th month (β = 0.59, P < 0.001). The association between follistatin and fT4 levels remained significant in the stepwise multivariate regression analysis, both initially and at the 6th month.In comparison to the EU group, patients with hyperthyroidism had higher serum follistatin levels, which decreased after receiving antithyroid treatment. In addition, the serum follistatin concentrations were positively associated with serum fT4 levels in patients with hyperthyroidism or euthyroidism. 相似文献
86.
87.
Chin-Yun Pan Szu-Ting Chou Yu-Chuan Tseng Yi-Hsin Yang Chao-Yi Wu Ting-Hsun Lan Pao-Hsin Liu Hong-Po Chang 《The Kaohsiung journal of medical sciences》2012,28(12):673-678
This study evaluates the influence of different implant materials on the primary stability of orthodontic mini-implants by measuring the resonance frequency. Twenty-five orthodontic mini-implants with a diameter of 2 mm were used. The first group contained stainless steel mini-implants with two different lengths (10 and 12 mm). The second group included titanium alloy mini-implants with two different lengths (10 and 12 mm) and stainless steel mini-implants 10 mm in length. The mini-implants were inserted into artificial bones with a 2-mm-thick cortical layer and 40 or 20 lb/ft3 trabecular bone density at insertion depths of 2, 4, and 6 mm. The resonance frequency of the mini-implants in the artificial bone was detected with the Implomates® device. Data were analyzed by two-way analysis of variance followed by the Tukey honestly significant difference test (α = 0.05). Greater insertion depth resulted in higher resonance frequency, whereas longer mini-implants showed lower resonance frequency values. However, resonance frequency was not influenced by the implant materials titanium alloy or stainless steel. Therefore, the primary stability of a mini-implant is influenced by insertion depth and not by implant material. Insertion depth is extremely important for primary implant stability and is critical for treatment success. 相似文献
88.
89.
90.
Zhuhuang Zhou Dar-In Tai Yung-Liang Wan Jeng-Hwei Tseng Yi-Ru Lin Shuicai Wu Kuen-Cheh Yang Yin-Yin Liao Chih-Kuang Yeh Po-Hsiang Tsui 《Ultrasound in medicine & biology》2018,44(7):1327-1340
Nonalcoholic fatty liver disease is a type of hepatic steatosis that is not only associated with critical metabolic risk factors but can also result in advanced liver diseases. Ultrasound parametric imaging, which is based on statistical models, assesses fatty liver changes, using quantitative visualization of hepatic-steatosis–caused variations in the statistical properties of backscattered signals. One constraint with using statistical models in ultrasound imaging is that ultrasound data must conform to the distribution employed. Small-window entropy imaging was recently proposed as a non–model-based parametric imaging technique with physical meanings of backscattered statistics. In this study, we explored the feasibility of using small-window entropy imaging in the assessment of fatty liver disease and evaluated its performance through comparisons with parametric imaging based on the Nakagami distribution model (currently the most frequently used statistical model). Liver donors (n?=?53) and patients (n?=?142) were recruited to evaluate hepatic fat fractions (HFFs), using magnetic resonance spectroscopy and to evaluate the stages of fatty liver disease (normal, mild, moderate and severe), using liver biopsy with histopathology. Livers were scanned using a 3-MHz ultrasound to construct B-mode, small-window entropy and Nakagami images to correlate with HFF analyses and fatty liver stages. The diagnostic values of the imaging methods were evaluated using receiver operating characteristic curves. The results demonstrated that the entropy value obtained using small-window entropy imaging correlated well with log10(HFF), with a correlation coefficient r?=?0.74, which was higher than those obtained for the B-scan and Nakagami images. Moreover, small-window entropy imaging also resulted in the highest area under the receiver operating characteristic curve (0.80 for stages equal to or more severe than mild; 0.90 for equal to or more severe than moderate; 0.89 for severe), which indicated that non–model-based entropy imaging—using the small-window technique—performs more favorably than other techniques in fatty liver assessment. 相似文献