全文获取类型
收费全文 | 2702篇 |
免费 | 160篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 58篇 |
妇产科学 | 129篇 |
基础医学 | 276篇 |
口腔科学 | 71篇 |
临床医学 | 223篇 |
内科学 | 564篇 |
皮肤病学 | 29篇 |
神经病学 | 201篇 |
特种医学 | 116篇 |
外国民族医学 | 3篇 |
外科学 | 505篇 |
综合类 | 26篇 |
一般理论 | 3篇 |
预防医学 | 132篇 |
眼科学 | 106篇 |
药学 | 168篇 |
中国医学 | 2篇 |
肿瘤学 | 234篇 |
出版年
2024年 | 2篇 |
2023年 | 24篇 |
2022年 | 45篇 |
2021年 | 119篇 |
2020年 | 79篇 |
2019年 | 105篇 |
2018年 | 163篇 |
2017年 | 113篇 |
2016年 | 91篇 |
2015年 | 90篇 |
2014年 | 128篇 |
2013年 | 160篇 |
2012年 | 241篇 |
2011年 | 244篇 |
2010年 | 148篇 |
2009年 | 96篇 |
2008年 | 170篇 |
2007年 | 158篇 |
2006年 | 130篇 |
2005年 | 124篇 |
2004年 | 115篇 |
2003年 | 115篇 |
2002年 | 102篇 |
2001年 | 18篇 |
2000年 | 8篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1979年 | 1篇 |
排序方式: 共有2875条查询结果,搜索用时 31 毫秒
31.
Aim: Several tests are available for aphasia screening following stroke. However, some of them have shortcomings such as need of specialist knowledge, low sensitivity and/or specificity and lengthy administration time. Our study aims to evaluate the language component of the Addenbrooke's Cognitive Examination – Revised (ACE‐R) as a screening tool for aphasia in stroke patients. Methods: The language component of ACE‐R was administered to consecutive patients admitted to a post‐acute stroke unit. Patients who were medically unstable or had a significant history of sensory impairment or mental health issues were excluded. The test was administered by two junior doctors with basic training in ACE‐R administration. Patients recruited were also assessed by an experienced speech and language therapist (SLT). The results of the two assessments were documented by a different member of the team and the SLT results were used as the benchmark to calculate the ACE‐R language component sensitivity and specificity. Results: Fifty‐nine participants were recruited and 27 of them were women. The mean age was 72 (SD 11.9). Thirty‐four participants had left and 11 right hemisphere stroke. Fourteen had bilateral affection. Six participants were left handed. A cut‐off value of 22/26 of ACE‐R language component showed 100% specificity and 83.1% sensitivity, while a cut‐off value of 16/26 had 88.2% specificity and 100% sensitivity. Conclusion: Our results suggest that the language component of ACE‐R has a satisfactory sensitivity and specificity compared with other screening tests used in strokes. It is easy to administer and free to use. 相似文献
32.
33.
34.
Analysis of IN.PACT DEEP trial on the association between changes in perfusion from pre‐ to postrevascularization and clinical outcomes in critical limb ischemia
下载免费PDF全文
![点击此处可从《Catheterization and cardiovascular interventions》网站下载免费的PDF全文](/ch/ext_images/free.gif)
35.
36.
Clinicopathological analysis of papillary thyroid cancer with PIK3CA alterations in a Middle Eastern population 总被引:1,自引:0,他引:1
Abubaker J Jehan Z Bavi P Sultana M Al-Harbi S Ibrahim M Al-Nuaim A Ahmed M Amin T Al-Fehaily M Al-Sanea O Al-Dayel F Uddin S Al-Kuraya KS 《The Journal of clinical endocrinology and metabolism》2008,93(2):611-618
CONTEXT: Genetic aberration in phosphatidylinositol 3-kinase (PI3K)/AKT pathway has been detected in numerous and diverse human cancers. PIK3CA, which encodes for the catalytic subunit of p110alpha of PI3K, is amplified in some cases of papillary thyroid cancer (PTC). Mutations in the PIK3CA have also been identified in thyroid cancers and, although relatively common in anaplastic thyroid carcinoma, are uncommon in PTC. OBJECTIVE: The objective of the study was to investigate genetic alterations like PIK3CA gene mutation, PIK3CA amplification, RAS, and RAF mutations and to further explore the relationship of these genetic alterations with various clinicopathological characteristics in Middle Eastern PTC. DESIGN: We used the fluorescence in situ hybridization technique for analysis of PIK3CA amplification from 536 PTC cases, and selected amplified samples were further validated by real-time quantitative PCR. Mutation analysis was done by direct DNA sequencing of PIK3CA, N2-RAS, and BRAF genes. RESULTS: PIK3CA amplification was seen in 265 of 499 PTC cases analyzed (53.1%); PIK3CA gene mutations in four of 207 PTC (1.9%); N2-RAS mutations in 16 of 265 PTC (6%); and BRAF mutations in 153 of 296 PTC (51.7%). N-RAS mutations were-associated with an early stage (P = 0.0465) and lower incidence of extrathyroidal extension (P = 0.027), whereas BRAF mutations were-associated with metastasis (P = 0.0274) and poor disease-free survival (P = 0.0121) in PTCs. CONCLUSION: A higher incidence of PIK3CA alterations and the possible synergistic effect of PIK3CA alterations and BRAF mutations suggest their major role in Middle Eastern PTC tumorigenesis and argue for therapeutic targeting of PI3K/AKT and MAPK pathways. 相似文献
37.
38.
Dieterich DT Wasserman R Bräu N Hassanein TI Bini EJ Bowers PJ Sulkowski MS 《The American journal of gastroenterology》2003,98(11):2491-2499
OBJECTIVE: The aim of this study was to determine the efficacy of epoetin alfa in alleviating anemia and minimizing ribavirin (RBV) dose reductions in patients with chronic hepatitis C virus (HCV) infection receiving combination RBV/interferon alfa (IFN) therapy. METHODS: HCV-infected patients who had Hb levels of 12 g/dl or less during the first 24 wk of combination RBV/IFN therapy (n=64) were randomized to treatment with epoetin alfa (40,000 units) s.c. q.w. or to standard of care (SOC) for anemia management (RBV dose reduction or discontinuation, transfusions). Primary and secondary efficacy endpoints were changes in Hb level and RBV dosage, respectively, from baseline to week 16 of epoetin alfa therapy.Based on intent-to-treat analysis, the mean changes from baseline Hb levels at week 16 were +2.8 g/dl for epoetin alfa versus +0.4 g/dl for SOC (p<0.0001), and the mean changes in RBV dosage were -34 mg/day for epoetin alfa versus -146 mg/day (p=0.060) for SOC. The mean Hb level at week 16 in the epoetin alfa group (13.8 g/dl) was significantly (p<0.0001) higher than that of the SOC group (11.4 g/dl). At week 4 and subsequently, significantly more patients in the epoetin alfa group did not have RBV dosage reductions (p<0.011). At study end, 83% of epoetin alfa-treated patients maintained RBV dosages of at least 800 mg/day, compared with 54% of patients receiving SOC (p=0.022). Epoetin alfa was well tolerated. CONCLUSIONS: In anemic HCV-infected patients treated with RBV/IFN, epoetin alfa increases Hb levels and maintains RBV dosing. Based on these results, epoetin alfa seems to be promising in the treatment of HCV treatment-related anemia. Further research is warranted to determine the potential impact on outcomes, including quality of life and sustained viral response rate. 相似文献
39.
Tarek Alsaied Lynn A. Sleeper Marco Masci Sunil J. Ghelani Nina Azcue Tal Geva Andrew J. Powell Rahul H. Rathod 《Journal of cardiovascular magnetic resonance》2018,20(1):85
Background
Maldistribution of pulmonary artery blood flow (MPBF) is a potential complication in patients who have undergone single ventricle palliation culminating in the Fontan procedure. Cardiovascular magnetic resonance (CMR) is the best modality that can evaluate MPBF in this population. The purpose of this study is to identify the prevalence and associations of MPBF and to determine the impact of MPBF on exercise capacity after the Fontan operation.Methods
This retrospective single-center study included all patients after Fontan operation who had maximal cardiopulmonary exercise test (CPET) and CMR with flow measurements of the branch pulmonary arteries. MPBF was defined as >?20% difference in branch pulmonary artery flow. Exercise capacity was measured as percent of predicted oxygen consumption at peak exercise (% predicted VO2). Linear and logistic regression models were used to determine univariate and multivariable predictors of exercise capacity and correlates of MPBF, respectively.Results
A total of 147 patients who had CMR between 1999 and 2017 were included (median age at CMR 21.8?years [interquartile range (IQR) 16.5–30.6]) and the median time between CMR and CPET was 2.8?months [IQR 0–13.8]. Fifty-three patients (36%) had MPBF (95% CI 29–45%). The mean % predicted VO2 was 63?±?16%. Patients with MPBF had lower mean % predicted VO2 compared to patients without MPBF (60?±?14% versus 65?±?16%, p?=?0.04). On multivariable analysis, a lower % predicted VO2 was independently associated with longer time since Fontan, higher ventricular mass-to-volume ratio, and MPBF. On multivariable analysis, only compression of the branch pulmonary arteries by the ascending aorta or aortic root was associated with MPBF (OR 6.5, 95% CI 5.6–7.4, p?<?0.001).Conclusion
In patients after the Fontan operation, MPBF is common and is independently associated with lower exercise capacity. MPBF was most likely to be caused by pulmonary artery compression by the aortic root or the ascending aorta. This study identifies MPBF as an important risk factor and as a potential target for therapeutic interventions in this fragile patient population.40.
Mohamed Tarek M. Youssef Menna Allah M. Bakry Azza A. El-Keiy Mai M. 《Metabolic brain disease》2021,36(2):255-264
Metabolic Brain Disease - The foremost neurodegenerative disease is Alzheimer’s (AD), which is characterized as a gradual decrease in memory, cognitive function, and also personal changes... 相似文献