全文获取类型
收费全文 | 475篇 |
免费 | 15篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 8篇 |
妇产科学 | 10篇 |
基础医学 | 30篇 |
口腔科学 | 4篇 |
临床医学 | 44篇 |
内科学 | 193篇 |
皮肤病学 | 7篇 |
神经病学 | 29篇 |
特种医学 | 55篇 |
外科学 | 53篇 |
综合类 | 3篇 |
一般理论 | 1篇 |
预防医学 | 7篇 |
眼科学 | 1篇 |
药学 | 20篇 |
中国医学 | 1篇 |
肿瘤学 | 14篇 |
出版年
2023年 | 1篇 |
2022年 | 12篇 |
2021年 | 9篇 |
2020年 | 9篇 |
2019年 | 9篇 |
2018年 | 18篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 13篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 40篇 |
2011年 | 47篇 |
2010年 | 18篇 |
2009年 | 18篇 |
2008年 | 30篇 |
2007年 | 34篇 |
2006年 | 29篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 24篇 |
2002年 | 22篇 |
2001年 | 13篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有490条查询结果,搜索用时 359 毫秒
1.
2.
Usefulness of leg-crossing for maintaining blood pressure in a sitting position in patients with orthostatic hypotension--case reports 总被引:1,自引:0,他引:1
The authors report a case with idiopathic orthostatic hypotension in which the patient prevents his blood pressure from falling to a symptomatic level by leg-crossing in a sitting position. Including 4 other patients with orthostatic hypotension and 5 normal subjects, their study found that the changes in blood pressure with leg-crossing inversely correlated with those induced by assuming seated posture from a supine position. Leg-crossing may, therefore, be one of the useful nonpharmacologic measures for maintaining blood pressure in a sitting position in patients with orthostatic hypotension. 相似文献
3.
Objectives/Hypothesis: Vocal rehabilitation of patients who have undergone laryngectomy is best accomplished by a tracheoesophageal puncture. Optimal function of the prosthesis requires an adequate stoma. Patients with tracheostomal stenosis require revision of the stoma if vocal rehabilitation is to take place. Revision and tracheoesophageal placement are usually done as two separate procedures. Creating a tracheoesophageal fistula at the time of stomal revision has not been addressed in the literature. Study Design: Prospective analysis and follow-up of 10 patients undergoing simultaneous tracheoesophageal puncture and stomal revision for tracheostomal stenosis between 1991 and 1996. Methods: Ten patients were reviewed. An inferiorly based V-Y advancement flap was used so as not to interfere with the tracheoesophageal puncture. All patients had received radiation prior to revision and tracheoesophageal puncture. Patients were followed for a minimum of 2 years (range, 2–6 y; median, 3 y). Results: All patients maintained an adequate stoma without stenting. Eight of ten patients (80%) developed and maintained good tracheoesophageal speech. Two patients had their speech fistulas removed. There were no intraoperative or postoperative complications. Conclusions: Creation of a tracheoesophageal fistula at the time of stomal revision allows for vocal rehabilitation with a single visit to the operating room. Laryngoscope, 108:1509-1513, 1998 相似文献
4.
5.
6.
Multidetector-row computed tomography and magnetic resonance imaging of atherosclerotic lesions in human ex vivo coronary arteries 总被引:8,自引:0,他引:8
Nikolaou K Becker CR Muders M Babaryka G Scheidler J Flohr T Loehrs U Reiser MF Fayad ZA 《Atherosclerosis》2004,174(2):243-252
In the present study, we tested the ability of multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI) to identify and retrospectively characterize atherosclerotic lesions in human ex vivo coronary arteries. Thirteen ex vivo hearts were studied with MDCT and MRI. MDCT-images were obtained with an isotropic voxel size of 0.6mm(3). MR images were obtained with an in-plane resolution of 195 microm and 3mm slice thickness. All images were matched with histopathology sections. For both modalities, the sensitivity for the detection of any atherosclerotic lesion was evaluated, and a retrospective analysis of plaque morphology according to criteria defined by the American Heart Association (AHA) was performed. At histopathology, 28 atherosclerotic lesions were found. 21 and 23 of these lesions were identified by MDCT and MRI, respectively. Both modalities detected a small number of false-positive lesions. After retrospective matching with histopathology, MDCT as well as MRI were able to differentiate typical morpholocigal features for fatty, fibrous or calcified plaque components. Using the information presented in this study, in vivo coronary artery wall imaging using MDCT as well as MRI could be facilitated and supported for future investigations on this subject. 相似文献
7.
Cardiovascular risk factors associated with pulse pressure in a screened cohort in Okinawa, Japan. 总被引:6,自引:0,他引:6
Taku Inoue Mitsuteru Matsuoka Kazufumi Nagahama Chiho Iseki Takashi Touma Kunitoshi Iseki Kozen Kinjo Shuichi Takishita 《Hypertension research》2003,26(2):153-158
We evaluated the association between pulse pressure (PP) and cardiovascular risk factors in a screened cohort. Individuals who were receiving medications for hypertension or heart disease, who had no ECG record, or who had a record of arrhythmia were excluded. In total, 8,508 subjects (5,299 men and 3,209 women; age range, 18 to 89 years) were studied. Subjects were divided into four PP classes: PP.1 (PP < or = 40 mmHg, n=2,127), PP.2 (40 < or = PP < or = 44 mmHg, n=2,127), PP.3 (44 < or = PP < or = 50 mmHg, n=2,127) and PP.4 (50 mmHg < or = PP, n=2,127). Multiple regression analysis was used for evaluating the association between PP and cardiovascular risk factor or lifestyle. In men, the regression coefficient was 0.27 for age, 2.50 for diabetes mellitus, 0.33 for uric acid, 0.20 for body mass index, 0.07 for heart rate, -0.83 for current smoking habit and 1.23 for habitual drinking. In women, the regression coefficient was 0.37 for age, 4.09 for diabetes mellitus, 0.42 for body mass index, 0.14 for heart rate, and 0.84 for habitual exercise. In both men and women, PP was significantly increased in association with an increase in the number of risk factors (diabetes mellitus, obesity, current drinking status, heart rate, and hyperuricemia). In conclusion, higher PP was associated with cardiovascular risk factors. These associations were similar in both men and women. 相似文献
8.
Kang H. Zheng Sotirios Tsimikas Tania Pawade Jeffrey Kroon William S.A. Jenkins Mhairi K. Doris Audrey C. White Nyanza K.L.M. Timmers Jesper Hjortnaes Maximillian A. Rogers Elena Aikawa Benoit J. Arsenault Joseph L. Witztum David E. Newby Marlys L. Koschinsky Zahi A. Fayad Erik S.G. Stroes S. Matthijs Boekholdt Marc R. Dweck 《Journal of the American College of Cardiology》2019,73(17):2150-2162
Background
Lipoprotein(a) [Lp(a)], a major carrier of oxidized phospholipids (OxPL), is associated with an increased incidence of aortic stenosis (AS). However, it remains unclear whether elevated Lp(a) and OxPL drive disease progression and are therefore targets for therapeutic intervention.Objectives
This study investigated whether Lp(a) and OxPL on apolipoprotein B-100 (OxPL-apoB) levels are associated with disease activity, disease progression, and clinical events in AS patients, along with the mechanisms underlying any associations.Methods
This study combined 2 prospective cohorts and measured Lp(a) and OxPL-apoB levels in patients with AS (Vmax >2.0 m/s), who underwent baseline 18F-sodium fluoride (18F-NaF) positron emission tomography (PET), repeat computed tomography calcium scoring, and repeat echocardiography. In vitro studies investigated the effects of Lp(a) and OxPL on valvular interstitial cells.Results
Overall, 145 patients were studied (68% men; age 70.3 ± 9.9 years). On baseline positron emission tomography, patients in the top Lp(a) tertile had increased valve calcification activity compared with those in lower tertiles (n = 79; 18F-NaF tissue-to-background ratio of the most diseased segment: 2.16 vs. 1.97; p = 0.043). During follow-up, patients in the top Lp(a) tertile had increased progression of valvular computed tomography calcium score (n = 51; 309 AU/year [interquartile range: 142 to 483 AU/year] vs. 93 AU/year [interquartile range: 56 to 296 AU/year; p = 0.015), faster hemodynamic progression on echocardiography (n = 129; 0.23 ± 0.20 m/s/year vs. 0.14 ± 0.20 m/s/year] p = 0.019), and increased risk for aortic valve replacement and death (n = 145; hazard ratio: 1.87; 95% CI: 1.13 to 3.08; p = 0.014), compared with lower tertiles. Similar results were noted with OxPL-apoB. In vitro, Lp(a) induced osteogenic differentiation of valvular interstitial cells, mediated by OxPL and inhibited with the E06 monoclonal antibody against OxPL.Conclusions
In patients with AS, Lp(a) and OxPL drive valve calcification and disease progression. These findings suggest lowering Lp(a) or inactivating OxPL may slow AS progression and provide a rationale for clinical trials to test this hypothesis. 相似文献9.
Drousiotou A Touma EH Andreou N Loiselet J Angastiniotis M Verrelli BC Tishkoff SA 《Blood cells, molecules & diseases》2004,33(1):25-30
In the present study, we determined the frequency of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Cyprus using two different procedures in two separate adult population groups: a semiquantitative fluorescence test on blood spotted on filter paper and a quantitative spectrophotometric test on liquid blood. The frequency of G6PD deficiency among healthy adult males was found to be 5.1% using the semiquantitative procedure and 6.4% using the quantitative procedure. Neither method was able to detect all the expected female heterozygotes (5.3% and 47.1% of the expected number, respectively). A total of 21 male hemizygotes, 1 female homozygote and 9 female heterozygotes that tested positive for G6PD deficiency were studied at the molecular level. All 32 chromosomes were genotyped and five different mutations were identified. The Mediterranean mutation in exon 6 (563C-->T) (Ser188Phe) was found to be the most common variant in the Cypriot population, accounting for 52.6% of the deficient alleles. In the remaining chromosomes, four different mutations were identified: three known mutations, Kaiping 1388G-->A (Arg463His), Chatham 1003G-->A (Ala335Thr) and Acrokorinthos 463C-->G (His155Asp), and one previously undescribed mutation in exon 3, 148C-->T (Pro50Ser), which we called G6PD Kambos. We conclude that the frequency of G6PD deficiency in Cypriot males is 6.4%, and that this deficiency is the result of several different mutations. Although all the individuals carrying the Mediterranean variant can be detected using a semiquantitative screening method, a quantitative enzyme measurement is required to detect the G6PD variants with less severe enzyme deficiencies, while the most appropriate method for heterozygote detection is DNA analysis. 相似文献
10.