Sharif Digital Repository

In this work, an efficient treatment strategy for hepatitis C disease using interferon (IFN) has been proposed on the basis of the back-stepping control technique. The basic model of the hepatitis C virus (HCV) has been considered for controller design. To tackle the problem of model parameter variations, the adaptive version of the back-stepping method has been utilized. For applying the proposed treatment, all states should be available while only the viral load is measured. To solve this problem, a nonlinear Luenberger-like observer has been designed to estimate the unmeasured states. In the proposed treatment, limitation of the drug efficacy has been taken into account. Asymptotical... 

Studies have shown that balance and mobility in people with Parkinson's disease (PD) can improve through rehabilitation interventions. However, until now no quantitative method investigated how these patients improve their balance control. In this study, a single inverted pendulum model with PID controller was used to describe the improvement of forty PD patients after a 12-session therapy program, and to compare their balance with twenty healthy subjects. The Center of Pressure (COP) data were recorded in seven sensory conditions - on rigid and foam surface, each with eyes open and closed, and with visual disturbance; and stance on rigid surface with attached vibrator to the Achilles... 

Degenerative disc disease, associated with discrete structural changes in the peripheral annulus and vertebral endplate, is one of the most common pathological triggers of acute and chronic low back pain, significantly depreciating an individual's quality of life and instigating huge socioeconomic costs. Novel emerging therapeutic techniques are hence of great interest to both research and clinical communities alike. Exogenous crosslinking, such as Genipin, and platelet-rich plasma therapies have been recently demonstrated encouraging results for the repair and regeneration of degenerated discs, but there remains a knowledge gap regarding the quantitative degree of effectiveness and... 

Background:: Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments. Methods:: In this review, we first discussed the anatomy of the cornea and the required properties for... 

Recent progress in the areas of network science and control has shown a significant promise in understanding and analyzing epidemic processes. A well-known model to study epidemics processes used by both control and epidemiological research communities is the susceptible–infected–susceptible (SIS) dynamics to model the spread of disease/viruses over contact networks of infected and susceptible individuals. The SIS model has two metastable equilibria: one is called the endemic equilibrium and the other is known as the disease-free or healthy-state equilibrium. Control theory provides the tools to design control actions (allocating curing or vaccination resources) in order to achieve and... 

Diabetes, as a widespread chronic disease, is caused by the increase of blood glucose concentration (BGC) due to pancreatic insulin production failure and/or insulin resistance in the body. The artificial pancreas (AP) known as a closed-loop insulin delivery control system consists of a glucose sensor for BGC measurement, a control algorithm for calculation of exogenous insulin delivery rate (IDR), and an insulin infusion pump. The AP provides a closed-loop glucose-insulin regulatory system for type-1 diabetes mellitus (T1DM) patients in order to effectively reduce the high BGC level. In this paper, we aim to design a controller in order to regulate the BGC of T1DM patients at its basal... 

Diabetes, as a widespread chronic disease, is caused by the increase of blood glucose concentration (BGC) due to pancreatic insulin production failure and/or insulin resistance in the body. The artificial pancreas (AP) known as a closed-loop insulin delivery control system consists of a glucose sensor for BGC measurement, a control algorithm for calculation of exogenous insulin delivery rate (IDR), and an insulin infusion pump. The AP provides a closed-loop glucose-insulin regulatory system for type-1 diabetes mellitus (T1DM) patients in order to effectively reduce the high BGC level. In this paper, we aim to design a controller in order to regulate the BGC of T1DM patients at its basal... 

Since Gram-negative bacteria have a predominant role in nosocomial infections, there are high demands to develop a fast and sensitive method for diagnosis of bacteria in clinical samples. To address this challenge, we designed a novel electrochemical biosensor based on aptamers immobilized in engineered zeolitic imidazolate Framework-8 (ZIFs-8) via EDC-NHS chemistry. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were conducted to monitor the electrochemical characterization. With respect to unique π-πinteractions between aptamer and graphene oxide (GO), the differential pulse voltammetry technique was applied with ferrocene-graphene oxide (Fc-GO) as an... 

In this paper we study how the meso-scale and micro-scale electroencephalography (EEG) synchronization measures can be used for discriminating patients suffering from Alzheimer's disease (AD) from normal control subjects. To this end, two synchronization measures, namely power spectral density and multivariate phase synchronization, are considered and the topography of the changes in patients vs. Controls is shown. The AD patients showed increased power spectral density in the frontal area in theta band and widespread decrease in the higher frequency bands. It was also characterized with decreased multivariate phase synchronization in the left fronto-temporal and medial regions, which was... 

In this study, we have proposed a novel method investigates MR-Images for normal and abnormal brains which effected by Alzheimer's Disease (AD) to extract 336 number of different features based on texture analysis. Before applying this algorithm, we have to use a registration method because of variety in size of normal and abnormal images. Consequently, the output of Texture Analysis System (TAS) is a vector containing 336 elements that are features extracted from texture. This vector is considered as the input of the Artificial Neural Network (ANN) which is feed-forward one. The features extracted from the Gray-level Co-occurrence Matrix (GLCM) have been interpreted and compared with normal... 

Although graphene/stem cell-based tissue engineering has recently emerged and has promisingly and progressively been utilized for developing one of the most effective regenerative nanomedicines, it suffers from low differentiation efficiency, low hybridization after transplantation and lack of appropriate scaffolds required in implantations without any degrading in functionality of the cells. In fact, recent studies have demonstrated that the unique properties of graphene can successfully resolve all of these challenges. Among various stem cells, neural stem cells (NSCs) and their neural differentiation on graphene have attracted a lot of interest, because graphene-based neuronal tissue... 

COVID-19, as the most significant epidemic of the century, infected 467 million people and took the lives of more than 6 million individuals as of March 19, 2022. Due to the rapid transmission of the disease and the lack of definitive treatment, countries have employed non-pharmaceutical interventions. This study aimed to investigate the effectiveness of the smart travel ban policy, which has been implemented for non-commercial vehicles in the intercity highways of Iran since November 21, 2020. The other goal was to suggest efficient COVID-19 forecasting tools and to examine the association of intercity travel patterns and COVID-19 trends in Iran. To this end, weekly confirmed cases and... 

Conformational diseases have been investigated extensively in recent years; as a result, a number of drug candidates have been introduced as amyloid inhibitors; however, no effective therapies have been put forward. RS-0406 with pyridazine as its core chemical structure has so far shown promising results in inhibiting amyloid formation. In the present work, using molecular dynamics, we undertook the investigation of RS-0406 interactions with U-shaped Aβ1−42 and Aβ1−40 pentamers, Aβ1−42 monomers, and double-horseshoe-like Aβ1−42. To set better parameters for the small molecule, experimental and computational log P values were obtained. In addition, an analogue of RS-0406 was also simulated... 

Obstruction of left anterior descending artery (LAD) due to the thrombosis or atherosclerotic plaques is the leading cause of death worldwide. Targeted delivery of drugs through micro- and nanoparticles is a very promising approach for developing new strategies in clot-busting or treating restenosis. In this work, we modelled the blood flow characteristics in a patient-specific reconstructed LAD artery by the fluid–solid interaction method and based on physiological boundary conditions. Next, we provided a Lagrangian description of micro- and nanoparticles dynamics in the blood flow considering their Brownian motion and the particle–particle interactions. Our results state that the number of... 

Obstruction of left anterior descending artery (LAD) due to the thrombosis or atherosclerotic plaques is the leading cause of death worldwide. Targeted delivery of drugs through micro- and nanoparticles is a very promising approach for developing new strategies in clot-busting or treating restenosis. In this work, we modelled the blood flow characteristics in a patient-specific reconstructed LAD artery by the fluid–solid interaction method and based on physiological boundary conditions. Next, we provided a Lagrangian description of micro- and nanoparticles dynamics in the blood flow considering their Brownian motion and the particle–particle interactions. Our results state that the number of... 

Image fusion means to integrate information from one image to another image. Medical images according to the nature of the images are divided into structural (such as CT and MRI) and functional (such as SPECT, PET). This article fused MRI and PET images and the purpose is adding structural information from MRI to functional information of PET images. The images decomposed with Nonsubsampled Contourlet Transform and then two images were fused with applying fusion rules. The coefficients of the low frequency band are combined by a maximal energy rule and coefficients of the high frequency bands are combined by a maximal variance rule. Finally, visual and quantitative criteria were used to... 

Research question: Would there be differences in muscle activation between healthy subjects’ (HS) dominant leg and transfemoral amputees’ (TFA) intact-leg/contralateral-limb (IL) during normal transient-state walking speed? Methods: The muscle activation patterns are obtained by calculating the linear envelope of the EMG signals for each group. The activation patterns/temporal changes are compared between-population using statistical parametric mapping (SPM). Results: Individual muscle activity showed significant differences in all muscles except vastus lateralis (VL), semitendinosus (SEM) and tensor fascia latae (TFL) activities. Significance: The information could be used by the therapists... 

In recent years, the role of optically sensitive nanomaterials has become powerful moieties in therapeutic techniques and has become particularly emphasized. Currently, by the extraordinary development of nanomaterials in different fields of medicine, they have found new applications. Phototherapy modalities, such as photothermal therapy (PTT) by toxic heat generation and photodynamic therapy (PDT) by reactive oxygen species, are known as promising phototherapeutic techniques, which can overcome the limitations of conventional protocols. Moreover, nanomaterial-based PDT and PTT match the simultaneous immune therapy and increase the immune system stimulation resulting from the denaturation of... 

Coronary artery disease (CAD) causes oscillations in peripheral arteries. Oscillations of the walls of the brachial arteries of 51 patients were recorded [together with the electrocardiogram (ECG)] by an accelerometer at different cuff pressures. By analyzing the energy of the oscillations in the 30-250 Hz band, 16 of 22 patients with CAD and 26 of 29 non-CAD subjects were classified correctly, independent of the ECG, and with no effect of heart murmurs  

In this paper, a nonlinear robust adaptive sliding mode control strategy is presented for the influenza epidemics in the presence of model uncertainties. The nonlinear epidemiological model of influenza with five state variables (the numbers of susceptible, exposed, infected, asymptomatic and recovered individuals) and two control inputs (vaccination and antiviral treatment) is considered. The objective of the proposed controller is decreasing the number of susceptible and infected humans to zero by tracking the desired scenarios. As a result of this decreasing, the number of exposed and asymptomatic individuals is also decreased and converged to the zero. Accordingly, it is shown that the...