Risk factors associated with long covid syndrome: A retrospective study

Background: Recently, people have recognized the post-acute phase symptoms of the COVID-19. We investigated the long-term symptoms associated with COVID-19, (Long COVID Syndrome), and the risk factors associated with it. Methods: This was a retrospective observational study. All the consecutive adult patients referred to the healthcare facilities anywhere in Fars province from 19 February 2020 until 20 November 2020 were included. All the patients had a confirmed COVID-19 diagnosis. In a phone call to the patients, at least three months after their discharge from the hospital, we obtained their current information. The IBM SPSS Statistics (version 25.0) was used. Pearson Chi square, Fisher’s exact test, t test, and binary logistic regression analysis model were employed. A P value of less than 0.05 was considered to be significant. Results: In total, 4,681 patients were studied, 2915 of whom (62.3%) reported symptoms. The most common symptoms of long COVID syndrome were fatigue, exercise intolerance, walking intolerance, muscle pain, and shortness of breath. Women were more likely to experience long-term COVID syndrome than men (Odds Ratio: 1,268; 95% Confidence Interval: 1,122-1,432; P=0.0001), which was significant. Presentation with respiratory problems at the onset of illness was also significantly associated with long COVID syndrome (Odds Ratio: 1.425; 95% Confidence Interval: 1.177-1.724; P=0.0001). A shorter length of hospital stay was inversely associated with long COVID syndrome (Odds Ratio: 0.953; 95% Confidence Interval: 0.941-0.965; P=0.0001). Conclusion: Long COVID syndrome is a frequent and disabling condition and has significant associations with sex (female), respiratory symptoms at the onset, and the severity of the illness

High Signal-to-Noise Ratio Successive Approximation Analog to Digital Converters

RÉSUMÉ: Les systèmes d'acquisition de données nécessitent des convertisseurs anaologique numérique (CAN) multicanaux, offrant de hautes performances et des larges bandes passantes. Ces besoins ont abouti à la conception de structures hybrides. Les CAN à registre d'approximations successives avec mise en forme du bruit (NS-SAR) ont montré des performances très intéressantes en termes d'énergie/surface en combinant les avantages des CAN à registre d'approximations successives et ceux à modulateurs delta-sigma (ΔΣMs). Étant compatibles avec de haut niveau d'intégration technologique, les CAN NS-SAR resteront une solution prometteuse dans l'avenir. Améliorer les performances des CAN NS-SAR sans augmenter la complexité de la conception des circuits et des techniques d'étalonnage est une exigence primordiale. D'autre part, les CAN incrémentiels hybrides (IADC) à partage de matériel et multi-étapes ont présenté les meilleures performances pour les applications multicanaux en ajoutant plusieurs avantages aux ΔΣMs. Les principaux facteurs qui limitent l'efficacité des IADC sont la bande passante étroite, la grande consommation d'énergie des intégrateurs basés sur l'amplificateur à transimpédance (OTA) des quantificateurs à plusieurs bits, le taux élevé de suréchantillonnage (OSR) et la complexité des architectures hybrides. Cette thèse contribue à ce sujet en proposant deux architectures de CAN basées sur des CAN NS-SAR. Premièrement, l'architecture de mise en forme du bruit à plusieurs étages (MASH) améliore l'ordre de mise en forme du bruit (NS) des CAN NS-SAR, en ajoutant une deuxième étape avec des exigences de conception assouplies et, sans excès significatif de complexité et de consommation d'énergie supplémentaires. Ce CAN est implémenté en technologie ST-28nm FD-SOI, réalisant une opération de NS de quatrième ordre avec un rapport signal sur bruit et sur distorsion (SNDR) de 75 dB et un taux de suréchantillonnage (OSR) de 10 avec une bande passante de 100 kHz. Deuxièmement, l'utilisation de la structure MASH NS-SAR proposée dans un mode incrémental en deux étapes augmente l'ordre de NS à six et atteint une résolution adéquate pour un système d'acquisition de données multicanal combinant les avantages des IADC multi-étapes, le CAN NS-SAR et la topologie MASH. Les structures proposées dans cette thèse sont caractérisées par un OSR requis plus faible, des quantificateurs SAR à faible puissance et un retour d'erreur (EF) basé sur un amplificateur à faible gain au lieu de filtres à boucle d'intégration en cascade (CIFF) basés sur des OTA de haute performance. Une simulation à l'aide d'un macro-modèle dans Cadence Spectre® a été réalisée pour vérifier l'idée proposée. De plus, des simulations basées sur SIMULINK®, modélisant les imperfections des circuits, et les équations analytiques dérivées prédisent les performances ainsi que la consommation d'énergie de l'architecture proposée. ABSTRACT: High channel-density data acquisition systems require high-performance and wide-bandwidth multi-channel analog to digital converters (ADCs). This demand resulted in an approach to designing hybrid structures. Noise-shaping successive approximation register (NS-SAR) ADCs have shown power/area-efficient performance combining the advantages of SAR ADCs and delta-sigma (ΔΣ) modulators. Being technology scaling friendly, NS-SAR ADCs will remain a promising solution in the future. Improving the performance of NS-SAR ADCs without increasing the complexity of circuit design and calibration methods is a crucial requirement. On the other hand, multi-step hardware-sharing hybrid incremental ADCs (IADCs) have presented the best performance for the multi-channel applications, adding several advantages to ΔΣMs. Narrow bandwidth, high power consumption of the operational transconductance amplifiers (OTA)-based integrators and multi-bit quantizers, high oversampling ratio (OSR), and complex hybrid architectures limit the efficiency of IADCs. This thesis contributes to this topic by proposing two ADC structures based on NS-SAR ADCs. First, multi-stage noise-shaping (MASH) architecture enhances the NS order of NSSAR ADCs, adding a second stage with relaxed design requirements without significant additional complexity and power consumption. This ADC is implemented in ST-28nm fully depleted silicon-on-insulator (FD-SOI) technology, achieving a fourth-order NS operation with an signal-to-noise-and-distortion-ratio (SNDR) of 75 dB and OSR of 10 at a bandwidth of 100 kHz. Second, using the proposed MASH NS-SAR structure in a two-step incremental mode augments the NS order to six and achieves a resolution suitable for the multi-channel data acquisition system combining advantages of multi-step IADCs, NS-SAR ADCs, and MASH topology. Lower required OSR, low-power SAR quantizers, and low-gain amplifierbased error feedback (EF) instead of OTA-based cascaded integrator feedforward (CIFF) loop filters address the limitations of hybrid multi-step IADCs. A macro-model simulation in Cadence Spectre® was performed to verify the proposed idea. Furthermore, SIMULINKbased simulations, modeling the circuit imperfections and the derived analytical equations, predict the proposed architecture's performance and power consumption

Research Paper: Effect of Play-based Therapy on Metacognitive and Behavioral Aspects of Executive Function: A Randomized, Controlled, Clinical Trial on the Students With Learning Disabilities

Introduction: Although the effect of educational methods on executive function (EF) is well known, training this function by a playful method is debatable. The current study aimed at investigating if a play-based intervention is effective on metacognitive and behavioral skills of EF in students with specific learning disabilities. Methods: In the current randomized, clinical trial, 49 subjects within the age range of 7 to 11 years with specific learning disabilities were randomly assigned into the intervention (25 subjects; mean age 8.5±1.33 years) and control (24 subjects; mean age 8.7±1.03 years) groups. Subjects in the intervention group received EF group training based on playing activities; subjects in the control group received no intervention. The behavior rating inventory of executive function (BRIEF) was administered to evaluate the behavioral and cognitive aspects of EF. The duration of the intervention was 6 hours per week for 9 weeks. Multivariate analysis of covariance was used to compare mean changes (before and after) in the BRIEF scores between the groups. Results: The assumptions of multivariate analysis of covariance were examined. After controlling pre-test conditions, the intervention and control groups scored significantly differently on both the metacognition (P=0.002; effect size=0.20) and behavior regulation indices (P=0.01; effect size=0.12) of BRIEF.  Conclusion: Play-based therapy is effective on the metacognitive and behavioral  aspects of EF in students with specific learning disabilities. Professionals can use play-based therapy rather than educational approaches in clinical practice to enhance EF skills