全文获取类型
收费全文 | 1332篇 |
免费 | 97篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 59篇 |
妇产科学 | 25篇 |
基础医学 | 177篇 |
口腔科学 | 45篇 |
临床医学 | 147篇 |
内科学 | 318篇 |
皮肤病学 | 39篇 |
神经病学 | 60篇 |
特种医学 | 153篇 |
外科学 | 99篇 |
综合类 | 40篇 |
预防医学 | 118篇 |
眼科学 | 13篇 |
药学 | 55篇 |
中国医学 | 4篇 |
肿瘤学 | 78篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 16篇 |
2020年 | 19篇 |
2019年 | 30篇 |
2018年 | 24篇 |
2017年 | 28篇 |
2016年 | 27篇 |
2015年 | 29篇 |
2014年 | 37篇 |
2013年 | 57篇 |
2012年 | 43篇 |
2011年 | 37篇 |
2010年 | 75篇 |
2009年 | 57篇 |
2008年 | 44篇 |
2007年 | 51篇 |
2006年 | 44篇 |
2005年 | 45篇 |
2004年 | 29篇 |
2003年 | 40篇 |
2002年 | 31篇 |
2001年 | 22篇 |
2000年 | 38篇 |
1999年 | 27篇 |
1998年 | 52篇 |
1997年 | 41篇 |
1996年 | 43篇 |
1995年 | 28篇 |
1994年 | 40篇 |
1993年 | 32篇 |
1992年 | 23篇 |
1991年 | 14篇 |
1990年 | 16篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 20篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 10篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1979年 | 9篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1974年 | 7篇 |
1973年 | 10篇 |
排序方式: 共有1446条查询结果,搜索用时 15 毫秒
61.
62.
63.
AL Naik A Savlania A Gupta P Rastogi A Singh 《Annals of the Royal College of Surgeons of England》2021,103(3):e94
Behçet’s disease is a rare disease characterised by recurrent oral ulcers, with systemic manifestations including genital ulcers, ocular disease, skin lesions, gastrointestinal disease, neurologic disease, vascular disease and arthritis. Most clinical manifestations of Behçet’s disease are believed to be due to vasculitis. The heterogeneous clinical spectrum is influenced by sex, ethnicity and country of residence. Vascular manifestation in the form of isolated large brachial artery aneurysm is rare in children. Treatment involves aneurysmorrhaphy to avoid rupture or ischaemic sequelae in addition to lifelong medical management to control vasculitis. 相似文献
64.
65.
66.
Burling D Halligan S Atchley J Dhingsar R Guest P Hayward S Higginson A Jobling C Kay C Lilford R Maskell G McCafferty I McGregor J Morton D Kumar Neelala M Noakes M Philips A Riley P Taylor A Bassett P Wardle J Atkin W Taylor SA 《Clinical radiology》2007,62(5):424-9; discussion 430-1
AIM: To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice. MATERIALS AND METHODS: Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation. RESULTS: Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced radiologists (mean 75 versus 88%, p=0.04) but not significantly different from recently trained radiologists (p=0.48). Interpretation time was not significantly different to experienced readers (mean 12.4 min versus 11.7, p=0.74), but shorter than recently trained radiologists (p=0.05). There was a significant, positive, linear correlation between prior experience and accuracy (p<0.001) with no plateau. CONCLUSION: Accuracy for sub-specialist radiologists working in a non-academic environment is, on average, equivalent to radiologists trained using 50 cases. However, there is wide variability in individual performance, which generally falls short of the average performance suggested by meta-analysis of published data. Experience improves accuracy, but alone is insufficient to determine competence. 相似文献
67.
Halligan S Marshall M Taylor S Bartram C Bassett P Cardwell C Atkin W 《Clinical radiology》2003,58(12):948-54; discussion 945-7
AIM: To assess inter-observer error for the diagnosis of neoplasia on double contrast barium enema (DCBE) in the light of claims that no additional interpretative training would be needed for implementation in a national screening programme. MATERIALS AND METHODS: 10 experts, 10 consultants, and 10 experienced trainees each reported 20 DCBE studies, of which two showed cancer, three showed large polyps, four showed small polyps, and 12 were normal. Inter-observer variation was compared using odds ratios with the trainee group as reference (baseline group). RESULTS: Experts were significantly more likely to correctly identify neoplasia on DCBE than trainees. The odds of a correct diagnosis for experts were 2.79 (95% CI 2.04, 3.81) for cancer, 2.36 (1.88, 2.97) for large polyps, and 3.50 (1.98, 6.18) for small polyps. While consultants were more likely to correctly diagnose a large polyp than trainees, 1.45 (1.15, 1.84), there was no significant difference between these two groups for the correct diagnosis of either cancer, 1.24 (0.52, 2.96), or small polyps, 1.26 (0.83, 1.90). A cancer was missed by 6 (60%) experts, 9 (90%) consultants, and 8 (80%) trainees. Large polyps were missed by 4 (40%) experts, 5 (50%) consultants, and 6 (60%) trainees. There was no significant difference between any group when false positive diagnoses were considered. CONCLUSIONS: There is considerable inter-observer perceptive error for the diagnosis of neoplasia on DCBE. Experts performed significantly better than other observers but the overall standard of performance was poor, even amongst experts. 相似文献
68.
Cardiovascular effects at multi-detector row CT colonography compared with those at conventional endoscopy of the colon 总被引:4,自引:0,他引:4
Taylor SA Halligan S O'Donnell C Morley S Mistry H Saunders BP Vance M Bassett P Windsor A Stern Y Bethel H Atkin W Bartram CI 《Radiology》2003,229(3):782-790
PURPOSE: To compare the cardiovascular effects of computed tomographic (CT) colonography and conventional endoscopy in a group of patients undergoing both procedures. MATERIALS AND METHODS: A total of 144 patients underwent CT colonography followed by flexible sigmoidoscopy (40 patients) or colonoscopy (104 patients). Pulse, blood pressure, and oxygen saturation were measured before, during, and after the procedures. Forty patients also underwent continuous Holter electrocardiographic (ECG) monitoring. Periprocedural pain was assessed by using a handheld counting device. Outcome variables were assessed by using a combination of paired t testing and multilevel linear regression. RESULTS: When a spasmolytic was not used, CT colonography was associated with only a small increase in oxygen saturation (P =.03), while use of a spasmolytic caused an increase in pulse (mean increase, 19.9 beats per minute; P <.001) and diastolic blood pressure (mean increase, 5 mm Hg; P <.001). Compared with that at CT, oxygen saturation decreased significantly during and after colonoscopy and sigmoidoscopy (mean decrease after colonoscopy with sedation, 1.0%; P <.001). Systolic and diastolic blood pressure also decreased during and after colonoscopy (mean systolic decrease after colonoscopy with sedation, 16.6 mm Hg, P <.001; mean diastolic decrease after colonoscopy with sedation, 7.5 mm Hg, P <.001). Patients were 30.3 times more likely to develop bradycardia after endoscopy (95% CI: 2.65, 346; P =.006). Ventricular couplets were significantly higher at endoscopy than at CT in patients with a history of cardiac disease (odds ratio: 72.5 and 95% CI: 4.56, 1,153 at CT vs odds ratio: 14.6 and 95% CI: 0.96, 222 at endoscopy; P =.002). Patients were 1.89 times more likely to register pain during colonoscopy than during CT (95% CI: 1.06, 3.38; P =.03). CONCLUSION: CT colonography had no significant cardiovascular effect other than spasmolytic-induced tachycardia. Endoscopy-and colonoscopy in particular-causes cardiovascular effects that are largely related to sedation. CT colonography is less painful than colonoscopy and is comparable to flexible sigmoidoscopy. 相似文献
69.
Summary The use of three‐dimensional (3D) models of the dentition obtained from cone beam computed tomography (CBCT) is becoming increasingly more popular in dentistry. A recent trend is to replace the traditional dental casts with digital CBCT models for diagnosis, treatment planning and simulation. The accuracy of these models was previously assessed through comparing linear physical and radiographical measurements. However, this assessment technique is both observer and landmark dependent. The accuracy of 3D CBCT teeth reconstructions is yet to be reliably measured. To assess the accuracy of 3D CBCT reconstructions of the teeth using a semi‐automated and observer‐independent method and to assess the influence of field of view (FoV) selection on reconstruction accuracy. Fully dentate upper and lower dry human jaws, placed in a plastic box and immersed in water, were scanned using CBCT with small, medium and large FoV. The teeth were then scanned separately using MicroCT. Cone beam computed tomography and MicroCT 3D teeth models were compared, and mean surface difference was calculated per tooth for each FoV. Mean and (maximum) differences between MicroCT and CBCT were 120 ± 40 (max. 679) μm, 157 ± 39 (max. 824) μ and 207 ± 80 (max. 862) μm for the small, medium and large FoV, respectively. Cone beam computed tomography models were larger than MicroCT because of larger voxel size. Our results indicate that CBCT may provide accurate 3D reconstructions of the teeth that can be useful for some clinical applications. 相似文献
70.