Publications by authors named "Sahrai M"

Background: Although obesity is on the rise in Afghanistan, to date no studies have investigated associations with diet and dietary patterns. Therefore, the present study aimed to assess the different dietary patterns consumed among Afghan adults living in Kandahar province and evaluate the correlations between those predominant dietary patterns and anthropometric measures.

Methods: A cross-sectional study was conducted in Kandahar, Afghanistan, where data on sociodemographic characteristics, anthropometric measurements and diet were collected.

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Objective: Hypertension exerts a substantial financial burden on individuals, families, communities, and the health system of a country. The current study aimed to describe the association of hypertension with its main risk factors in the Afghan population living in Kandahar city.

Results: The prevalence of tobacco smoking, naswar use, physical activity and a healthy diet was 22%, 55%, 63.

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A nondiffracting propagation of an optical beam through a four-level double-V-type quantum system near a plasmonic nanostructure is investigated. We study the linear absorption and dispersion properties of the quantum system as it interacts with two laser fields. We discuss the effect of the control beam with a Laguerre-Gaussian (LG) profile on the focusing of the probe beam in the presence of a plasmonic nanostructure.

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Background: Successful implementation of preventive measures and level of awareness in particular among university students in Afghanistan could play a crucial role in spreading the information for better control of the ongoing pandemic. Therefore, the aim of this study was to determine the level of knowledge, attitudes and practices (KAP) regarding COVID-19 among Kandahar university students.

Methods: A cross-sectional study conducted among undergraduate students to investigate their KAP regarding COVID-19 from January to March, 2021.

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The Hartman effect is studied in a one dimensional photonic crystal doped with graphene quantum dots. It is shown that the Hartman effect can be switched from negative to positive by increasing the Rabi-frequency of the controlling field and also by manipulating the relative phase of the applied fields. The effect of the vortex beam on the Hartman effect is also presented.

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A narrow-band transmission filter based on one-dimensional photonic crystals with /() layers is grown by sol-gel spin-coating processing. The structural and optical properties of fabricated samples are characterized by an atomic force microscope, scanning electron microscope, and UV-visible spectroscopy. Specific wavelength transmission and bandgap in the optical filter with and without a defect layer have been investigated by engineering the layer thickness and defect layer material.

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Utilizing the vortex beams, we investigate the entanglement between the triple-quantum dot molecule and its spontaneous emission field. We present the spatially dependent quantum dot-photon entanglement created by Laguerre-Gaussian (LG) fields. The degree of position-dependent entanglement (DEM) is controlled by the angular momentum of the LG light and the quantum tunneling effect created by the gate voltage.

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Background: Soil-transmitted helminth (STH) infections are still a major health problem, especially in resource-limited countries. The community-based prevalence of STH is unknown in Afghanistan. Main objectives of this study were to estimate the prevalence and associated factors of STH among children in Daman district of Kandahar province in Afghanistan.

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A five-level atomic system is proposed in vicinity of a two-dimensional (2D) plasmonic nanostructure with application in atom-photon entanglement. The behavior of the atom-photon entanglement is discussed with and without a control laser field. The amount of atom-photon entanglement is controlled by the quantum interference created by the plasmonic nanostructure.

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Background: Non-communicable diseases (NCDs) cause more than 70% of deaths worldwide and share modifiable risk factors including obesity and metabolic abnormalities. Over the past 15 years, many changes in lifestyle, dietary patterns, physical activity, and socioeconomic status have been observed in the Afghan population. This study aims to investigate which specific lifestyle factors, dietary patterns, and characteristics of Westernization are associated with an increased risk of being overweight or obese and with poor metabolic health in the Afghan population.

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We consider a four-level molecular system with two ground-state vibrational levels and two excited-state vibrational levels inside a constant cavity configuration. We discuss the reflected and transmitted Goos-Hänchen (GH) shifts of a positive and negative single-chirped laser pulse. The impacts of the laser field detuning, intensity of applied laser field, and appropriately tuning the chirp rate on GH shifts are then analyzed.

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We investigate the quantum linear and nonlinear effects in a novel five-level quantum system placed near a plasmonic nanostructure. Such a quantum scheme contains a double-V-type subsystem interacting with a weak probe field. The double-V-subsystem is then coupled to an excited state by a strong coupling field, which can be a position-dependent standing-wave field.

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In this study, we investigated the possibility of interactions between the solvent molecules with the Heme group in the human hemoglobin. The results of this study answer a key question: whether the interactions of the Heme unit with its surroundings are interdependent or independent of the protein units of human hemoglobin. Contributions of the intermolecular interactions were determined by exploiting the solvatochromism spectroscopic data by Kamlet-Taft (KAT) polarity functions.

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We theoretically investigate the optical and magneto-optical Faraday and Kerr rotations of a probe field that propagates through a nonmagnetic dielectric slab doped with double-V type atoms. Both rotations and corresponding ellipticities, as well as the intensities of transmitted and reflected beams, are modified by quantum coherence induced in the atomic system. We show that applying a control laser field makes the system optically active and simultaneously, transparent to one component of the probe field.

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We study the nonlinear optical properties in an asymmetric double AlGaAs/GaAs quantum well nanostructure by using an external control field and resonant tunneling effects. It is found that the resonant tunneling can modulate the third-order and fifth-order of susceptibilities via detuning frequency of coupling light. In presence of the resonant tunneling and when the coupling light is in resonance with the corresponding transition, the real parts of third-order and fifth-order susceptibilities are enhanced which are accompanied by nonlinear absorption.

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We propose a new model for a fiber Bragg grating (FBG) filter based on one-dimensional defective photonic bandgap structures, which operates within telecom windows. The device is realized in an asymmetric $ {{\rm SiO}_2}/{{\rm TiO}_2} $SiO/TiO photonic crystal (PC) microcavity with the defect layer of the graphene disk placed in the center of the structure. The theoretical analysis of the optical properties of the narrowband FBG filter is given based on the combination of the density matrix approach with the transfer matrix method.

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Flexoelectric coefficients of carbon nanotube (CNT) doped nematic liquid crystals (NLCs) are studied based on the Helfrich theory. Weak and hard anchoring conditions between the NLC molecules and CNTs are considered. The volume fraction of the CNTs in nematic host is assumed to be low, which makes nanotubes aggregation phenomena negligible.

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Background: Population-specificity of exploratory dietary patterns limits their generalizability in investigations with type 2 diabetes incidence.

Objective: The aim of this study was to derive country-specific exploratory dietary patterns, investigate their association with type 2 diabetes incidence, and replicate diabetes-associated dietary patterns in other countries.

Methods: Dietary intake data were used, assessed by country-specific questionnaires at baseline of 11,183 incident diabetes cases and 14,694 subcohort members (mean age 52.

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This cross-sectional study aimed to evaluate associations between a priori defined dietary patterns and anthropometric measures in Mexican women. A total of 1062 women aged 35 to 69 years old from the control participants of the CAMA (Cancer de Mama) study, a multi-center population-based case-control study on breast cancer conducted in Mexico, were interviewed and dietary intakes were assessed using questionnaires. The following indices were derived from these data: Dietary Approaches to Stop Hypertension (DASH) score, the Healthy Eating Index (HEI), the Mediterranean Diet Score (aMED), the Diet Quality Index (DQI), glycemic index (GI) and glycemic load (GL).

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We discuss the light pulse propagation in a one-dimensional photonic crystal doped by graphene quantum dots in a defect layer. The graphene quantum dots behave as a three-level quantum system and are driven by three coherent laser fields. It is shown that the group velocity of the transmitted and reflected pulses can be switched from subluminal to superluminal light propagation by adjusting the relative phase of the applied fields.

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We propose a multilayer medium with semiconductor quantum dot nano-structures as a defect layer for all-optical control of the 1.55 μm probe beam. The effect of the coupling field and incoherent pump on absorption and dispersion properties of the quantum dot defect layer is investigated.

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A compact design for semiconductor cavities including coupled AlGaN/AlGaAs quantum wells is proposed for all-optical switching of the bistability process. First, physical and geometrical parameters are optimized to engineer the conducting electrons' energy levels in the quantum wells. Then, finite element simulations based on Schrödinger equations are executed to estimate the states of the charge carriers for AlGaN/AlGaAs as the active region.

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The paper is aimed at modeling the enhanced Kerr nonlinearity in a five-level double-ladder-type atomic system based on electromagnetically induced transparency (EIT) by using the semi-classical density matrix method. We present an analytical model to explain the origin of Kerr nonlinearity enhancement. The scheme also results in a several orders of magnitude increase in the Kerr nonlinearity in comparison with the well-known four- and three-level atomic systems.

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This paper presents the Goos-Hänchen (GH) shifts of a probe light beam in a fixed cavity configuration containing the three level V-type atomic medium. We found that in the presence of decay-induced interference, the lateral shifts of both the reflected and transmitted probe light beam can easily be controlled just by the relative phase of applied fields. We also discuss the intensity of the applied field on GH shifts of the reflected and transmitted probe light beam.

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