All-optical modulation in a CMOS-compatible amorphous silicon-based device

Active silicon photonic devices, which dynamically control the flow of light, have received significant attention for their use in on-chip optical networks. High-speed active silicon photonic modulators and switches rely on the plasma dispersion effect, where a change in carrier concentration causes a variation in the refractive index. The necessary electron and hole concentration change can be introduced either by optical pumping, or by direct electrical injection and depletion. We demonstrate a fast photoinduced absorption effect in low loss hydrogenated amorphous silicon (a-Si:H) waveguides deposited at a temperature as low as 190°C. Significant modulation (M% ~90%) occurs with a 1 mm-long device. We attribute the enhanced modulation to the significantly larger free-carrier absorption effect of a-Si:H. The complementary metal-oxide semiconductor (CMOS) compatible technology of a-Si:H could be considered as a promising candidate to enable an easy back-end integration with standard microelectronics processes

OSAS severity is associated to decreased heart rate turbulence slope

Obstructive sleep apnea syndrome (OSAS) has been associated to impaired baroreflex sensitivity (BRS) which has recently been shown to be non-invasively assessed by heart rate turbulence (HRT) analysis. Although HRT seems to be better suited than traditional heart rate variability indexes for autonomic assessment in presence of respiratory and arrhythmic disorders, very few papers addressed its evaluation in OSAS. Aim of the study is to find out whether and to which extend HRT is associated to OSAS severity. We studied HRT in polysomnographic recordings of 221 mild to severe OSAS pts. Results showed that, while HRT onset values did not significantly differ between mild (-0,78±1,50), moderate (-0,89±1,78) and severe (-0,70±1,28) pts., HRT slope significantly decreases (Kruskal-Wallis P value <0.05) from mild (3,27±2,7) to moderate (2,6±2,6) and severe (1,98±2,5) pts., with a significant Dunn's multiple comparisons post test only between mild vs. severe OSAS pts. Data indicate that the main BRS alterations do not appear in the early HRT phase triggered by transient vagal inhibition, but during the slow one, due to the sympathetic hyperactivity affecting the heart rate recovery. These findings support the conclusion that HRT assessment could have a prognostic value related to the development of cardiovascular disease in OSAS

Statistical Analysis and Kinematic Assessment of Upper Limb Reaching Task in Parkinson’s Disease

The impact of neurodegenerative disorders is twofold; they affect both quality of life and healthcare expenditure. In the case of Parkinson’s disease, several strategies have been attempted to support the pharmacological treatment with rehabilitation protocols aimed at restoring motor function. In this scenario, the study of upper limb control mechanisms is particularly relevant due to the complexity of the joints involved in the movement of the arm. For these reasons, it is difficult to define proper indicators of the rehabilitation outcome. In this work, we propose a methodology to analyze and extract an ensemble of kinematic parameters from signals acquired during a complex upper limb reaching task. The methodology is tested in both healthy subjects and Parkinson’s disease patients (N = 12), and a statistical analysis is carried out to establish the value of the extracted kinematic features in distinguishing between the two groups under study. The parameters with the greatest number of significances across the submovements are duration, mean velocity, maximum velocity, maximum acceleration, and smoothness. Results allowed the identification of a subset of significant kinematic parameters that could serve as a proof-of-concept for a future definition of potential indicators of the rehabilitation outcome in Parkinson’s disease

Evaluation of in vitro penetration of fluticasone propionate from MP-AzeFlu and fluticasone propionate nasal spray through EpiAirway (TM) 606 tissues using vertical diffusion cells

Purpose: Most patients with allergic rhinitis (AR) have moderate-to-severe disease, requiring complete and prompt relief when symptoms occur. The time course of fluticasone propionate (FP) penetration into nasal tissues after intranasal administration is not well characterized. The goal of this proof-of-concept study was to evaluate the mucosal penetration of FP from fixed-combination FP-azelastine nasal spray (MP-AzeFlu) compared with an FP-only nasal spray in an in vitro, 3-dimensional human bronchial tissue model. Materials and Methods: Absorption of FP from MP-AzeFlu and FP nasal spray was modeled using EpiAirway (TM) 606 (MatTek Corporation; Ashland, MA, USA) tissue cultured in vertical diffusion cells. The dosing amount of MP-AzeFlu was optimized in a pilot study. Based on the results of the pilot study, 10 mu L of MP-AzeFlu (3.65 mu g; n = 8) and 10 mu L of FP nasal spray (5.00 mu g; n = 8) were evaluated for penetration of tissue. Tissue integrity was monitored with Lucifer yellow. FP in the receiving media was quantified for each sample using liquid chromatography with tandem mass spectrometry. Results: MP-AzeFlu and FP nasal spray were associated with similar FP accumulation profiles in the receiving media, but the permeability of FP was greater for MP-AzeFlu during hours 0 to 6, suggesting faster absorption for MP-AzeFlu. No indications of compromised tissue integrity were found in any of the tested cells. Conclusion: The higher and more rapid penetration of FP from MP-AzeFlu supports the use of MP-AzeFlu for patients with AR, particularly when prioritizing fast and pronounced symptom relief

Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk

Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis

Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk

Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis

Methodes sub-optimales pour la suppression adaptative du fouillis

Dans plusieurs situations opérationnelles l'interférence des radars est composée d'un numéro limité de sources de fouillis (typiquement, jusqu' a deux) plus bruit blanc. Dans ce papier on présente une méthode paramétrique pour l'élimination adaptative de plusieurs sources de fouillis. Le filtre de suppression a tous les zéros sur le cercle unitaire; leur position dépends ou bien du rapport de puissance des sources (adaptivité paramétrique partielle) ou encore de leur corrélation (adaptivité paramétrique totale). Des stratégies simplifiées pour l'allocation des zéros comportent des trés petites pertes du facteur d'amélioration. Les filtres paramétriques optimal et sub-optimal ont été analyseés d'une façon detailée; les principaux résultats sont la position des zéros et le facteur d'amélioration avec deux sources de fouillis, sans erreurs d'éstimation