406 research outputs found

    Mie plasmons: modes volumes, quality factors and coupling strengths (Purcell factor) to a dipolar emitter

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    Using either quasi-static approximation or exact Mie expansion, we characterize the localized surface plasmons supported by a metallic spherical nanoparticle. We estimate the quality factor QnQ_n and define the effective volume VnV_n of the nthn^{th} mode in a such a way that coupling strength with a neighbouring dipolar emitter is proportional to the ratio Qn/VnQ_n/V_n (Purcell factor). The role of Joule losses, far-field scattering and mode confinement in the coupling mechanism are introduced and discussed with simple physical understanding, with particular attention paid to energy conservation.Comment: (in press) International Journal of Optics (2011

    Pharmacokinetics and pharmacodynamics of tiotropium solution and tiotropium powder in chronic obstructive pulmonary disease

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    The aim of the study was to characterize pharmacokinetics of tiotropium solution 5 µg compared to powder 18 µg and assess dose-dependency of tiotropium solution pharmacodynamics in comparison to placebo. In total 154 patients with chronic obstructive pulmonary disease (COPD) were included in this multicenter, randomized, double-blind within-solution (1.25, 2.5, 5 µg, and placebo), and open-label powder 18 µg, crossover study, including 4-week treatment periods. Primary end points were peak plasma concentration (Cmax,ss ), and area under the plasma concentration-time profile (AUC0-6h,ss ), both at steady state. The pharmacodynamic response was assessed by serial spirometry (forced expiratory volume in 1 second/forced vital capacity). Safety was evaluated as adverse events and by electrocardiogram/Holter. Tiotropium was rapidly absorbed with a median tmax,ss of 5-7 minutes postdosing for both devices. The gMean ratio of solution 5 µg over powder 18 µg was 81% (90% confidence interval, 73-89%) for Cmax,ss and 76% (70-82%) for AUC0-6h,ss , indicating that bioequivalence was not established. Dose ordering for bronchodilation was observed. Powder 18 µg and solution 5 µg were most effective, providing comparable bronchodilation. All treatments were well tolerated with no apparent relation to dose or device. Comparable bronchodilator efficacy to powder18 µg at lower systemic exposure supports tiotropium solution 5 µg for maintenance treatment of COPD

    PTA and stenting after previous aortoiliac endarterectomy

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    Objectives: to evaluate the feasibility and long-term results of angioplasty and stenting in the treatment of restenosis following aortoiliac endarterectomy. Materials and Methods: between 1991 and 1999 19 patients underwent angioplasty with selective stenting for recurrent stenosis after previous aortoiliac endarterectomy. Aortic lesions were treated five times in four patients. At the iliac level 28 lesions (25 stenosis and three occlusions) were treated in 16 patients (one patient had a stenosis at the aortic as well as iliac level). All patients were followed clinically and by ultrasound. In the second half of 1999, an angiogram or spiral CT-angiography was performed in all patients to determine long-term outcome. Results: technical success was obtained In all patients and clinical succes was achieved in 18 of the 19 patients, Angio,graphic cumulative primary patency for aortoiliac lesions was 96% at 1 year and 76% at 3 years, Conclusions: angioplasty with selective stenting of recurrent aortoiliac disease after previous aortoiliac endarterectomy is feasable and safe. Long-term clinical and angiographic patency rates are in accordance with results of aortoiliac angioplasty in general

    Endurance and Resistance Training in Radically Treated Respiratory Cancer patients: A Pilot Study

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    Introduction. Respiratory cancer and its treatment are known to contribute to muscle weakness and functional impairment. Aim. To assess the effects of rehabilitation in patients with respiratory cancer. Methods. Radically treated respiratory cancer patients were included in a 12-week multidisciplinary rehabilitation program. Results. 16 patients (age: 61 ± 7 years; FEV1: 57 ± 16% pred.) showed a reduced exercise tolerance (VO2max: 56 ± 15% pred.; 6 MWD: 67 ± 11% pred.), muscle force (PImax: 54 ± 22% pred.; QF: 67 ± 16% pred.), and quality of life (CRDQd: 17 ± 5 points; CRDQf: 16 ± 5 points). Exercise tolerance, muscle force, and quality of life improved significantly after rehabilitation. Conclusion. Radically treated patients with respiratory cancer have a decreased exercise capacity, muscle force, and quality of life. 12 weeks of rehabilitation leads to a significant improvement in exercise capacity, respiratory muscle force, and quality of life

    Curves of Placental Weights of Live-Born Twins

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    The purpose of this study is to present curves of estimated placental growth in twins and to evaluate the relative contribution of gestational age, zygosity, chorionicity, fusion of the placentas, sex of the individual and of the twin pair, site of the umbilical cord insertion, birth order, maternal age, and parity. Perinatal data and placental data were obtained from 6315 live-born twin pairs from the East Flanders Prospective Twin Survey. Of 4318 twin pairs, with no missing values, the placental weights of different gestational ages were analyzed using a nonlinear multivariate Gaussian regression. Two groups were distinguished: (1) twins with two separate placentas, and (2) twins with only one placental mass (one placenta in case of monochorionic twins or two fused placentas in case of dichorionic placentas). Overall, placental weight was influenced by gestational age, fusion of the placentas, and parity. In the case of one placental mass, monozygotic dichorionic twins had the lowest weights. If two separate placentas were present, birth order played a role in favor of the first-born twin. For parity and zygosity, the differences were most pronounced between 27 and 29 weeks, whereas the difference for birth order was most pronounced between 33 and 37 weeks. In conclusion, basic physiological characteristics, routinely examined at birth, influence placental weight. Taking these covariates into account allows a better evaluation of the placental weight given a gestational age, as an indicator of growth

    Rehabilitation in patients with radically treated respiratory cancer: A randomised controlled trial comparing two training modalities.

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    INTRODUCTION: The evidence on the effectiveness of rehabilitation in lung cancer patients is limited. Whole body vibration (WBV) has been proposed as an alternative to conventional resistance training (CRT). METHODS: We investigated the effect of radical treatment (RT) and of two rehabilitation programmes in lung cancer patients. The primary endpoint was a change in 6-min walking distance (6MWD) after rehabilitation. Patients were randomised after RT to either CRT, WBVT or standard follow-up (CON). Patients were evaluated before, after RT and after 12 weeks of intervention. RESULTS: Of 121 included patients, 70 were randomised to either CON (24), CRT (24) or WBVT (22). After RT, 6MWD decreased with a mean of 38m (95% CI 22-54) and increased with a mean of 95m (95% CI 58-132) in CRT (p<0.0001), 37m (95% CI -1-76) in WBVT (p=0.06) and 1m (95% CI -34-36) in CON (p=0.95), respectively. Surgical treatment, magnitude of decrease in 6MWD by RT and allocation to either CRT or WBVT were prognostic for reaching the minimally clinically important difference of 54m increase in 6MWD after intervention. CONCLUSIONS: RT of lung cancer significantly impairs patients' exercise capacity. CRT significantly improves and restores functional exercise capacity, whereas WBVT does not fully substitute for CRT
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