Search for: central-nervous-systems
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    Nanotechnology-Abetted Astaxanthin Formulations in Multimodel Therapeutic and Biomedical Applications

    , Article Journal of Medicinal Chemistry ; 2021 ; 00222623 (ISSN) Jafari, Z ; Bigham, A ; Sadeghi, S ; Dehdashti, S. M ; Rabiee, N ; Abedivash, A ; Bagherzadeh, M ; Nasseri, B ; Karimi Maleh, H ; Sharifi, E ; Varma, R. S ; Makvandi, P ; Sharif University of Technology
    American Chemical Society  2021
    Astaxanthin (AXT) is one of the most important fat-soluble carotenoids that have abundant and diverse therapeutic applications namely in liver disease, cardiovascular disease, cancer treatment, protection of the nervous system, protection of the skin and eyes against UV radiation, and boosting the immune system. However, due to its intrinsic reactivity, it is chemically unstable, and therefore, the design and production processes for this compound need to be precisely formulated. Nanoencapsulation is widely applied to protect AXT against degradation during digestion and storage, thus improving its physicochemical properties and therapeutic effects. Nanocarriers are delivery systems with many... 

    Integrated one-against-one classifiers as tools for virtual screening of compound databases: A case study with CNS inhibitors

    , Article Molecular Informatics ; Volume 32, Issue 8 , 2013 , Pages 742-753 ; 18681743 (ISSN) Jalali Heravi, M ; Mani-Varnosfaderani, A ; Valadkhani, A ; Sharif University of Technology
    A total of 21 833 inhibitors of the central nervous system (CNS) were collected from Binding-database and analyzed using discriminant analysis (DA) techniques. A combination of genetic algorithm and quadratic discriminant analysis (GA-QDA) was proposed as a tool for the classification of molecules based on their therapeutic targets and activities. The results indicated that the one-against-one (OAO) QDA classifiers correctly separate the molecules based on their therapeutic targets and are comparable with support vector machines. These classifiers help in charting the chemical space of the CNS inhibitors and finding specific subspaces occupied by particular classes of molecules. As a next... 

    Three dimensional modeling of axonal microtubules

    , Article 2014 21st Iranian Conference on Biomedical Engineering, ICBME 2014, 26 November 2014 through 28 November 2014 ; November , 2014 , Pages 298-302 ; 9781479974177 (ISBN) Manuchehrfar, F ; Shamloo, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2014
    Axon is a filament in neuronal system and axonal microtubules are bundles in axons. In axons, microtubules are coated with microtubule-associated protein tau, a natively unfolded profuse filamentous protein in the central nervous system. These proteins are responsible for the cross-linked structure of the axonal microtubule bundles. Through complimentary dimerization with other tau proteins, bridges are formed to nearby microtubules to create bundles. The transverse reinforcement of microtubules by cross-linking to the cytoskeleton has been shown to enhance their ability to bear compressive loads. Though microtubules are conventionally regarded as bearing compressive loads, in certain... 

    How resiliency and hope can predict stress of covid-19 by mediating role of spiritual well-being based on machine learning

    , Article Musculoskeletal Science and Practice ; Volume 51 , 2021 ; 24688630 (ISSN) Noorollahzadeh, K ; Kahrizi, S ; Fesharaki, M. G ; Heidarian, M ; Neblett, R ; Behzadipour, S ; Sharif University of Technology
    Elsevier Ltd  2021
    Background: The Central Sensitization Inventory (CSI) is a patient-reported tool to assess symptoms associated with central sensitization (CS). It consists of two parts: Part A assesses 25 somatic and emotional CS-related health symptoms, and part B asks if one has previously been diagnosed with a list of 10 Central Sensitivity Syndromes and related conditions. Objectives: The aim of this study was to translate and cross-culturally adapt the CSI into Persian and to evaluate its psychometric properties. Design: Cross-sectional study. Method: After completing the Persian translation, the psychometric properties of the Persian CSI (CSI-Per) were evaluated in 256 patients with chronic pain and... 

    How does the central nervous system address the kinetic redundancy in the lumbar spine? Three-dimensional isometric exertions with 18 Hill-model-based muscle fascicles at the L4-L5 level

    , Article Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine ; Volume 224, Issue 3 , 2010 , Pages 487-501 ; 09544119 (ISSN) Rashedi, E ; Khalaf, K ; Nassajian, M. R ; Nasseroleslami, B ; Parnianpour, M ; Sharif University of Technology
    The human motor system is organized for execution of various motor tasks in a different and flexible manner. The kinetic redundancy in the human musculoskeletal system is a significant property by which the central nervous system achieves many complementary goals. An equilibrium-based biomechanical model of isometric three-dimensional exertions of trunk muscles has been developed. Following the definition and role of the uncontrolled manifold, the kinetic redundancy concept is explored in mathematical terms. The null space of the kinetically redundant system when a certain joint moment and/or stiffness are needed is derived and discussed. The aforementioned concepts have been illustrated,... 

    A mixture of modular structures to describe human motor planning level: A new perspective based on motor decomposition

    , Article 2011 18th Iranian Conference of Biomedical Engineering, ICBME 2011 ; 2011 , Pages 199-204 ; 9781467310055 (ISBN) Sadeghi, M ; Andani, M. E ; Fattah, A ; Parnianpour, M ; Sharif University of Technology
    A modular hierarchical structure is developed to describe human movement planning level. The modular feature of the proposed model enables it to generalize planning a task. The movements are planned based on decomposing a task into its corresponding subtasks (motion phases). There is a module responsible for one condition. The final plan is constructed using soft computing of the plans proposed by different modules. Each module estimates the kinematics of the joints at the end of each subtask; we call them kinematic estimator modules (KEMs). A timing module estimates the duration of motion and a gating module determines the responsibility of each KEM under different conditions. To evaluate... 

    Application of Bhattacharyya distance as a dissimilarity index for automated prediction of epileptic seizures in rats

    , Article 2010 International Conference on Intelligent and Advanced Systems, ICIAS 2010, 15 June 2010 through 17 June 2010 ; 2010 ; 9781424466238 (ISBN) Niknazar, M ; Vosoughi Vahdat, B ; Shamsollahi, M. B ; Sayyah, M ; Sharif University of Technology
    Seizures are defined as manifest of excessive and hypersynchronous activity of neurons in the cerebral cortex and represent a frequent malfunction of the human central nervous system. Therefore, the search for precursors and predictors of a seizure is of utmost clinical relevance and may even guide us to a deep understanding of the seizure generating mechanisms. In this study we analyzed invasive electroencephalogram (EEG) recordings in rats with experimentally induced generalized epilepsy with a nonlinear method called, dissimilarity index. In order to predict epileptic seizures automatically, Bhattacharyya distance between trajectory matrix of reference window, during an interval quite... 

    Optimal control of human-like musculoskeletal arm: prediction of trajectory and muscle forces

    , Article Optimal Control Applications and Methods ; Volume 38, Issue 2 , 2017 , Pages 167-183 ; 01432087 (ISSN) Sharifi, M ; Pourtakdoust, S. H ; Parnianpour, M ; Sharif University of Technology
    Optimal trajectory and muscle forces of a human-like musculoskeletal arm are predicted for planar point-to-point movements using optimal control theory. The central nervous system (CNS) is modeled as an optimal controller that performs a reaching motion to final states via minimization of an objective function. For the CNS strategy, a cubic function of muscles stresses is considered as an appropriate objective function that minimizes muscles fatigue. A two-DOF nonlinear musculoskeletal planar arm model with four states and six muscle actuators is used for the evaluation of the proposed optimal strategy. The nonlinear variational formulation of the corresponding optimal control problem is... 

    Nonlinear optimal control of planar musculoskeletal arm model with minimum muscles stress criterion

    , Article Journal of Computational and Nonlinear Dynamics ; Volume 12, Issue 1 , 2017 ; 15551415 (ISSN) Sharifi, M ; Salarieh, H ; Behzadipour, S ; Sharif University of Technology
    American Society of Mechanical Engineers (ASME)  2017
    In this paper, the optimal performance of a planar humanlike musculoskeletal arm is investigated during reaching movements employing an optimal control policy. The initial and final states (position and velocity) are the only known data of the response trajectory. Two biomechanical objective functions are taken into account to be minimized as the central nervous system (CNS) strategy: (1) a quadratic function of muscle stresses (or forces), (2) total time of movement plus a quadratic function of muscle stresses. A two-degress of freedom (DOF) nonlinear musculoskeletal arm model (for planar movements) with six muscle actuators and four state variables is used in order to evaluate the proposed... 

    Development a planar neuro-musculoskeletal arm model in post-stroke patients

    , Article 26th National and 4th International Iranian Conference on Biomedical Engineering, ICBME 2019, 27 November 2019 through 28 November 2019 ; 2019 , Pages 236-241 ; 9781728156637 (ISBN) Nikzad Goltapeh, A ; Asghari, M ; Behzadipour, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Computational models of the central nervous system after a stroke helps to reveal the physiological mechanisms that may have strong impacts on the neuro-motor rehabilitation approaches. This paper studies the stroke subject's motor control mechanism in reaching movements by extending the previous study by incorporating the kinematics of motion as well as neural disconnection between the muscles and the CNS to further develop a planar patient specific neuro-musculoskeletal model of arm. The developed model was calibrated to eight post-stroke individuals by altering the Muscle Significance Factors (MFS) using numerical optimization to match the simulated motions with those measured... 

    EEG/PPG effective connectivity fusion for analyzing deception in interview

    , Article Signal, Image and Video Processing ; Volume 14, Issue 5 , 2020 , Pages 907-914 Daneshi Kohan, M ; Motie Nasrabadi, A ; Shamsollahi, M. B ; Sharifi, A ; Sharif University of Technology
    Springer  2020
    In this research, the interaction between electroencephalogram (EEG) and, a cardiac parameter, photoplethysmogram (PPG), using connectivity measures to emphasize the importance of autonomic nervous system over the central nervous system during a deception is investigated. In this survey, connectivity analysis was applied, since it can provide information flow of brain regions; moreover, lying and truth appear to be cohered with the flow of information in the brain. Initially, a new wavelet-based approach for EEG/PPG effective connectivity fusion was introduced; then, it was validated for 41 subjects. For each subject, after extracting specific wavelet component of EEG and PPG signals, an... 

    Adjustable primitive pattern generator: A novel cerebellar model for reaching movements

    , Article Neuroscience Letters ; Volume 406, Issue 3 , 2006 , Pages 232-234 ; 03043940 (ISSN) Vahdat, S ; Maghsoudi, A ; Haji Hasani, M ; Towhidkhah, F ; Gharibzadeh, S ; Jahed, M ; Sharif University of Technology
    Cerebellum has been assumed as an array of adjustable pattern generators (APGs). In recent years, electrophysiological researches have suggested the existence of modular structures in spinal cord called motor primitives. In our proposed model, each "adjustable primitive pattern generator" (APPG) module in the cerebellum is consisted of a large number of parallel APGs, the output of each module being the weighted sum of the outputs of these APGs. Each spinal field is tuned by a coefficient, representing a descending supraspinal command, which is modulated by ith APPG correspondingly. According to this model, motor control can be interpreted in terms of the modification of these coefficients.... 

    How well do the muscular synergies extracted via non-negative matrix factorisation explain the variation of torque at shoulder joint?

    , Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 16, Issue 3 , 2013 , Pages 291-301 ; 10255842 (ISSN) Moghadam, M. N ; Aminian, K ; Asghari, M ; Parnianpour, M ; Sharif University of Technology
    The way central nervous system manages the excess degrees of freedom to solve kinetic redundancy of musculoskeletal system remains an open question. In this study, we utilise the concept of synergy formation as a simplifying control strategy to find the muscle recruitment based on summation of identified muscle synergies to balance the biomechanical demands (biaxial external torque) during an isometric shoulder task. A numerical optimisation-based shoulder model was used to obtain muscle activation levels when a biaxial external isometric torque is imposed at the shoulder glenohumeral joint. In the numerical simulations, 12 different shoulder torque vectors in the transverse plane are... 

    Linear and non-linear dynamic methods toward investigating proprioception impairment in non-specific low back pain patients

    , Article Frontiers in Bioengineering and Biotechnology ; Volume 8 , 2020 Shokouhyan, S. M ; Davoudi, M ; Hoviattalab, M ; Abedi, M ; Bervis, S ; Parnianpour, M ; Brumagne, S ; Khalaf, K ; Sharif University of Technology
    Frontiers Media S.A  2020
    Central nervous system (CNS) uses vision, vestibular, and somatosensory information to maintain body stability. Research has shown that there is more lumbar proprioception error among low back pain (LBP) individuals as compared to healthy people. In this study, two groups of 20 healthy people and 20 non-specific low back pain (NSLBP) participants took part in this investigation. This investigation focused on somatosensory sensors and in order to alter proprioception, a vibrator (frequency of 70 Hz, amplitude of 0.5 mm) was placed on the soleus muscle area of each leg and two vibrators were placed bilaterally across the lower back muscles. Individuals, whose vision was occluded, were placed... 

    An improved multi-joint EMG-assisted optimization approach to estimate joint and muscle forces in a musculoskeletal model of the lumbar spine

    , Article Journal of Biomechanics ; Volume 44, Issue 8 , 2011 , Pages 1521-1529 ; 00219290 (ISSN) Gagnon, D ; Arjmand, N ; Plamondon, A ; Shirazi Adl, A ; Larivière, C ; Sharif University of Technology
    Muscle force partitioning methods and musculoskeletal system simplifications are key modeling issues that can alter outcomes, and thus change conclusions and recommendations addressed to health and safety professionals. A critical modeling concern is the use of single-joint equilibrium to estimate muscle forces and joint loads in a multi-joint system, an unjustified simplification made by most lumbar spine biomechanical models. In the context of common occupational tasks, an EMG-assisted optimization method (EMGAO) is modified in this study to simultaneously account for the equilibrium at all lumbar joints (M-EMGAO). The results of this improved approach were compared to those of its... 

    A bio-inspired modular hierarchical structure to plan the sit-to-stand transfer under varying environmental conditions

    , Article Neurocomputing ; Volume 118 , 2013 , Pages 311-321 ; 09252312 (ISSN) Sadeghi, M ; Emadi Andani, M ; Parnianpour, M ; Fattah, A ; Sharif University of Technology
    Human motion planning studies are of considerable importance in producing human-like trajectories for various industrial or clinical applications (e.g. assistive robots). In this case, the capability of Central Nervous System (CNS) in generating a large repertoire of actions can be inspirational to develop more efficient motion planning approaches. Here, inspired by structural and functional modularity in the CNS, a novel modular and hierarchical model is developed to plan the sit-to-stand (STS) transfer under varying environmental conditions. In this model, the planning process is distributed among several functionally simple modules. The cooperation of modules enables the model to plan the... 

    Is there a reliable and invariant set of muscle synergy during isometric biaxial trunk exertion in the sagittal and transverse planes by healthy subjects?

    , Article Journal of Biomechanics ; Volume 48, Issue 12 , Sep , 2015 , Pages 3234-3241 ; 00219290 (ISSN) Sedaghat Nejad, E ; Mousavi, S. J ; Hadizadeh, M ; Narimani, R ; Khalaf, K ; Campbell Kyureghyan, N ; Parnianpour, M ; Sharif University of Technology
    Elsevier Ltd  2015
    It has been suggested that the central nervous system simplifies muscle control through basic units, called synergies. In this study, we have developed a novel target-matching protocol and used non-negative matrix factorization (NMF) technique to extract trunk muscle synergies and corresponding torque synergies. Isometric torque data at the L5/S1 level and electromyographic patterns of twelve abdominal and back muscles from twelve healthy participants (five females) were simultaneously recorded. Each participant performed a total number of 24 isometric target-matching tasks using 12 different angular directions and 2 levels of uniaxial and biaxial exertions. Within- and between-subject... 

    Digital implementation of a biological astrocyte model and its application

    , Article IEEE Transactions on Neural Networks and Learning Systems ; Volume 26, Issue 1 , 2014 , Pages 127-139 ; 2162237X (ISSN) Soleimani, H ; Bavandpour, M ; Ahmadi, A ; Abbott, D ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2014
    This paper presents a modified astrocyte model that allows a convenient digital implementation. This model is aimed at reproducing relevant biological astrocyte behaviors, which provide appropriate feedback control in regulating neuronal activities in the central nervous system. Accordingly, we investigate the feasibility of a digital implementation for a single astrocyte and a biological neuronal network model constructed by connecting two limit-cycle Hopf oscillators to an implementation of the proposed astrocyte model using oscillator-astrocyte interactions with weak coupling. Hardware synthesis, physical implementation on field-programmable gate array, and theoretical analysis confirm... 

    Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor-critic reinforcement learning method

    , Article Computer Methods in Biomechanics and Biomedical Engineering ; Volume 8, Issue 2 , 2005 , Pages 103-113 ; 10255842 (ISSN) Golkhou, V ; Parnianpour, M ; Lucas, C ; Sharif University of Technology
    In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency. The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear musclelike- actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organlike sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex... 

    Recent advances in the design and applications of amyloid-β peptide aggregation inhibitors for Alzheimer’s disease therapy

    , Article Biophysical Reviews ; Volume 11, Issue 6 , 2019 , Pages 901-925 ; 18672450 (ISSN) Jokar, S ; Khazaei, S ; Behnammanesh, H ; Shamloo, A ; Erfani, M ; Beiki, D ; Bavi, O ; Sharif University of Technology
    Springer  2019
    Alzheimer’s disease (AD) is an irreversible neurological disorder that progresses gradually and can cause severe cognitive and behavioral impairments. This disease is currently considered a social and economic incurable issue due to its complicated and multifactorial characteristics. Despite decades of extensive research, we still lack definitive AD diagnostic and effective therapeutic tools. Consequently, one of the most challenging subjects in modern medicine is the need for the development of new strategies for the treatment of AD. A large body of evidence indicates that amyloid-β (Aβ) peptide fibrillation plays a key role in the onset and progression of AD. Recent studies have reported...