Displaying publications 321 - 340 of 616 in total

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  1. Fulltext Robust multiple frequency multiple power localization schemes in the presence of multiple jamming attacks
    Hussein AA, Leow CY, Rahman TA
    PLoS One, 2017;12(5):e0177326.
    PMID: 28493977 DOI: 10.1371/journal.pone.0177326
    Localization of the wireless sensor network is a vital area acquiring an impressive research concern and called upon to expand more with the rising of its applications. As localization is gaining prominence in wireless sensor network, it is vulnerable to jamming attacks. Jamming attacks disrupt communication opportunity among the sender and receiver and deeply impact the localization process, leading to a huge error of the estimated sensor node position. Therefore, detection and elimination of jamming influence are absolutely indispensable. Range-based techniques especially Received Signal Strength (RSS) is facing severe impact of these attacks. This paper proposes algorithms based on Combination Multiple Frequency Multiple Power Localization (C-MFMPL) and Step Function Multiple Frequency Multiple Power Localization (SF-MFMPL). The algorithms have been tested in the presence of multiple types of jamming attacks including capture and replay, random and constant jammers over a log normal shadow fading propagation model. In order to overcome the impact of random and constant jammers, the proposed method uses two sets of frequencies shared by the implemented anchor nodes to obtain the averaged RSS readings all over the transmitted frequencies successfully. In addition, three stages of filters have been used to cope with the replayed beacons caused by the capture and replay jammers. In this paper the localization performance of the proposed algorithms for the ideal case which is defined by without the existence of the jamming attack are compared with the case of jamming attacks. The main contribution of this paper is to achieve robust localization performance in the presence of multiple jamming attacks under log normal shadow fading environment with a different simulation conditions and scenarios.
    Matched MeSH terms: Computer Simulation
  2. Fulltext Docking Based 3D-QSAR Study of Tricyclic Guanidine Analogues of Batzelladine K As Anti-Malarial Agents
    Ahmed N, Anwar S, Thet Htar T
    Front Chem, 2017;5:36.
    PMID: 28664157 DOI: 10.3389/fchem.2017.00036
    The Plasmodium falciparum Lactate Dehydrogenase enzyme (PfLDH) catalyzes inter-conversion of pyruvate to lactate during glycolysis producing the energy required for parasitic growth. The PfLDH has been studied as a potential molecular target for development of anti-malarial agents. In an attempt to find the potent inhibitor of PfLDH, we have used Discovery studio to perform molecular docking in the active binding pocket of PfLDH by CDOCKER, followed by three-dimensional quantitative structure-activity relationship (3D-QSAR) studies of tricyclic guanidine batzelladine compounds, which were previously synthesized in our laboratory. Docking studies showed that there is a very strong correlation between in silico and in vitro results. Based on docking results, a highly predictive 3D-QSAR model was developed with q(2) of 0.516. The model has predicted r(2) of 0.91 showing that predicted IC50 values are in good agreement with experimental IC50 values. The results obtained from this study revealed the developed model can be used to design new anti-malarial compounds based on tricyclic guanidine derivatives and to predict activities of new inhibitors.
    Matched MeSH terms: Computer Simulation
  3. Review of numerical methods for simulation of mechanical heart valves and the potential for blood clotting
    Zakaria MS, Ismail F, Tamagawa M, Aziz AFA, Wiriadidjaja S, Basri AA, et al.
    Med Biol Eng Comput, 2017 Sep;55(9):1519-1548.
    PMID: 28744828 DOI: 10.1007/s11517-017-1688-9
    Even though the mechanical heart valve (MHV) has been used routinely in clinical practice for over 60 years, the occurrence of serious complications such as blood clotting remains to be elucidated. This paper reviews the progress that has been made over the years in terms of numerical simulation method and the contribution of abnormal flow toward blood clotting from MHVs in the aortic position. It is believed that this review would likely be of interest to some readers in various disciplines, such as engineers, scientists, mathematicians and surgeons, to understand the phenomenon of blood clotting in MHVs through computational fluid dynamics.
    Matched MeSH terms: Computer Simulation
  4. An analysis of simple computational strategies to facilitate the design of functional molecular information processors
    Lee Y, Roslan R, Azizan S, Firdaus-Raih M, Ramlan EI
    BMC Bioinformatics, 2016 Oct 28;17(1):438.
    PMID: 27793081
    BACKGROUND: Biological macromolecules (DNA, RNA and proteins) are capable of processing physical or chemical inputs to generate outputs that parallel conventional Boolean logical operators. However, the design of functional modules that will enable these macromolecules to operate as synthetic molecular computing devices is challenging.

    RESULTS: Using three simple heuristics, we designed RNA sensors that can mimic the function of a seven-segment display (SSD). Ten independent and orthogonal sensors representing the numerals 0 to 9 are designed and constructed. Each sensor has its own unique oligonucleotide binding site region that is activated uniquely by a specific input. Each operator was subjected to a stringent in silico filtering. Random sensors were selected and functionally validated via ribozyme self cleavage assays that were visualized via electrophoresis.

    CONCLUSIONS: By utilising simple permutation and randomisation in the sequence design phase, we have developed functional RNA sensors thus demonstrating that even the simplest of computational methods can greatly aid the design phase for constructing functional molecular devices.

    Matched MeSH terms: Computer Simulation
  5. Fulltext Preload-based Starling-like control of rotary blood pumps: An in-vitro evaluation
    Mansouri M, Gregory SD, Salamonsen RF, Lovell NH, Stevens MC, Pauls JP, et al.
    PLoS One, 2017;12(2):e0172393.
    PMID: 28212401 DOI: 10.1371/journal.pone.0172393
    Due to a shortage of donor hearts, rotary left ventricular assist devices (LVADs) are used to provide mechanical circulatory support. To address the preload insensitivity of the constant speed controller (CSC) used in conventional LVADs, we developed a preload-based Starling-like controller (SLC). The SLC emulates the Starling law of the heart to maintain mean pump flow ([Formula: see text]) with respect to mean left ventricular end diastolic pressure (PLVEDm) as the feedback signal. The SLC and CSC were compared using a mock circulation loop to assess their capacity to increase cardiac output during mild exercise while avoiding ventricular suction (marked by a negative PLVEDm) and maintaining circulatory stability during blood loss and severe reductions in left ventricular contractility (LVC). The root mean squared hemodynamic deviation (RMSHD) metric was used to assess the clinical acceptability of each controller based on pre-defined hemodynamic limits. We also compared the in-silico results from our previously published paper with our in-vitro outcomes. In the exercise simulation, the SLC increased [Formula: see text] by 37%, compared to only 17% with the CSC. During blood loss, the SLC maintained a better safety margin against left ventricular suction with PLVEDm of 2.7 mmHg compared to -0.1 mmHg for CSC. A transition to reduced LVC resulted in decreased mean arterial pressure (MAP) and [Formula: see text] with CSC, whilst the SLC maintained MAP and [Formula: see text]. The results were associated with a much lower RMSHD value with SLC (70.3%) compared to CSC (225.5%), demonstrating improved capacity of the SLC to compensate for the varying cardiac demand during profound circulatory changes. In-vitro and in-silico results demonstrated similar trends to the simulated changes in patient state however the magnitude of hemodynamic changes were different, thus justifying the progression to in-vitro evaluation.
    Matched MeSH terms: Computer Simulation
  6. Women in Computational Chemistry
    Wahab HA, Amaro RE, Cournia Z
    J Chem Inf Model, 2018 11 26;58(11):2175-2177.
    PMID: 30277769 DOI: 10.1021/acs.jcim.8b00642
    Matched MeSH terms: Computer Simulation
  7. Fulltext Development of a mechanistic dengue simulation model for Guangzhou
    Mincham G, Baldock KL, Rozilawati H, Williams CR
    Epidemiol Infect, 2019 01;147:e125.
    PMID: 30869038 DOI: 10.1017/S095026881900030X
    Dengue infection in China has increased dramatically in recent years. Guangdong province (main city Guangzhou) accounted for more than 94% of all dengue cases in the 2014 outbreak. Currently, there is no existing effective vaccine and most efforts of control are focused on the vector itself. This study aimed to evaluate different dengue management strategies in a region where this disease is emerging. This work was done by establishing a dengue simulation model for Guangzhou to enable the testing of control strategies aimed at vector control and vaccination. For that purpose, the computer-based dengue simulation model (DENSiM) together with the Container-Inhabiting Mosquito Simulation Model (CIMSiM) has been used to create a working dengue simulation model for the city of Guangzhou. In order to achieve the best model fit against historical surveillance data, virus introduction scenarios were run and then matched against the actual dengue surveillance data. The simulation model was able to predict retrospective outbreaks with a sensitivity of 0.18 and a specificity of 0.98. This new parameterisation can now be used to evaluate the potential impact of different control strategies on dengue transmission in Guangzhou. The knowledge generated from this research would provide useful information for authorities regarding the historic patterns of dengue outbreaks, as well as the effectiveness of different disease management strategies.
    Matched MeSH terms: Computer Simulation
  8. Molecular docking studies of selected medicinal drugs as dengue virus-2 protease inhibitors
    Rufaidah Othman, Saiful Anuar Karsani, Rozana Othman, Aida Baharuddin, Ramakrishnan NR, Noorsaadah Abd. Rahman, et al.
    Sains Malaysiana, 2017;46:1865-1875.
    Dengue is a potentially deadly disease with no effective drug. An in silico molecular docking was performed using Autodock
    4.2.6 to investigate the molecular interactions between protease inhibitors, comprising antibiotic derivatives namely
    doxycycline (3), rolitetracycline (5) and a non-steroidal anti-inflammatory drug (NSAID), meclofenamic acid (4), against
    the NS2B-NS3 protease from dengue virus-2 (DENV-2). The non-competitive inhibitor (3) showed lower binding energy
    (-5.15 kcal/mol) than the predicted competitive inhibitors 4 and 5 (-3.64 and -3.21 kcal/mol, respectively). Structural
    analyses showed compound 3 that bound to a specific allosteric site, interacted with Lys74, a significant amino acid
    residue bonded to one of the catalytic triad, Asp75. Compounds 4 and 5 showed direct binding with two of the catalytic
    triad, His51 and Ser135, hence, predicted to be competitive inhibitors.
    Matched MeSH terms: Computer Simulation
  9. Anticipating local flaps closed-form solution on 3D face models using finite element method
    Kwan Z, Khairu Najhan NN, Yau YH, Luximon Y, M Nor F
    Int J Numer Method Biomed Eng, 2020 11;36(11):e3390.
    PMID: 32735083 DOI: 10.1002/cnm.3390
    A realistic three-dimensional (3D) computational model of skin flap closures using Asian-like head templates from two different genders, male and female, has been developed. The current study aimed to understand the biomechanics of the local flap designs along with the effect of wound closures on the respective genders. Two Asian head templates from opposite genders were obtained to use as base models. A third-order Yeoh hyperelastic model was adapted to characterize as skin material properties. A single layer composed of combined epidermis and dermis was considered, and the models were thickened according to respective anatomical positions. Each model gender was excised with a fixed defect size which was consequently covered by three different local flap designs, namely advancement, rotation, and rhomboid flaps. Post-operative simulation presented various scenarios of skin flap closures. Rotation and rhomboid flaps demonstrated maximal tension at the apex of the flap for both genders as well as advancement flap in the female face model. However, advancement flap closure in the male face model was presented otherwise. Yet, the deformation patterns and the peak tension of the discussed flaps were consistent with conventional local flap surgery. Moreover, male face models generated higher stresses compared to the female face models with a 70.34% mean difference. Overall, the skin flap operations were executed manually, and the designed surgery model met the objectives successfully while acknowledging the study limitations. NOVELTY FILE: 3D head templates were considered to address the gap as 3D face models were uncommonly employed in understanding the biomechanics of the local flaps realistically. Most of the existing studies focus on the 2D and 3D planar geometry in their models. As gender comparison has yet to be addressed, we intended to fill this gap by exploring the stress contours of the local flap designs in different genders. Create a 3D face model from two opposite genders which is capable of simulating closure of wounds using local flaps with a focus on advancement, rotation, and rhomboid flaps.
    Matched MeSH terms: Computer Simulation
  10. Simulation of Rainfall-Runoff Response in Ecological Swale with On-Line Subsurface Detention Using Infoworks SD
    Ghadim HB, Hin LS
    Water Environ Res, 2017 Sep 01;89(9):862-870.
    PMID: 28855022 DOI: 10.2175/106143017X14902968254764
      The Bio-Ecological Drainage System (BIOECODS) is a sustainable drainage (SUDS) to demonstrate the 'control at source' approaches for urban stormwater management in Malaysia. It is an environmentally friendly drainage system that was designed to increase infiltration, reduce peak flow at outlet, improve water quality, through different BMPs, such as grass swale, retention pond, etc. A special feature of BIOECODS is ecological swale with on-line subsurface detention. This study attempted to create a model of ecological swale with on-line subsurface conveyance system with InfoWorks SD. The new technique has been used Storm Water Management Model (SWMM) model to describe overland flow routing and Soil Conservation Service Method (SCS) used to model infiltration or subsurface flow. The modeling technique has been proven successful, as the predicted and observed closely match each other, with a mean error of 4.58 to 7.32%. The calibrated model then used to determine the ratio of the flow exchange between the surface and subsurface drainage system. Results from the model showed that the runoff ratio exchange between the surface and subsurface is 60 to 90%.
    Matched MeSH terms: Computer Simulation
  11. Effect of different stent configurations using Lattice Boltzmann method and particles image velocimetry on artery bifurcation aneurysm problem
    Mokhtar NH, Abas A, Razak NA, Hamid MNA, Teong SL
    J Theor Biol, 2017 11 21;433:73-84.
    PMID: 28844907 DOI: 10.1016/j.jtbi.2017.08.016
    Proper design of stent for application at specific aneurysm effect arteries could help to reduce the issues with thrombosis and aneurysm. In this paper, four types of stent configuration namely half-Y (6 mm), half-Y (4 mm), cross-bar, and full-Y configuration will implanted on real 3D artery bifurcation aneurysm effected arteries. Comparisons were then conducted based on the flow patterns after stent placement using both LBM-based solver and PIV experimental findings. According to the data obtained from all 4 stent designs, the flow profiles and the computed velocity from both methods were in agreement with each other. Both methods found that half-Y (6 mm) stent configuration is by far the best configuration in reducing the blood velocity at the vicinity of the aneurysm sac. The analysis also show that the half-Y (6 mm) stent configuration recorded the highest percentage of velocity reduction and managed to substantially reduce the pressure at the bifurcation region. This high flow velocity reduction through the use of half-Y stent could consequently promote the formation of thrombus thereby reducing the risk of rupture in the aneurysm sac.
    Matched MeSH terms: Computer Simulation
  12. A fuzzy logic control in adjustable autonomy of a multi-agent system for an automated elderly movement monitoring application
    Mostafa SA, Mustapha A, Mohammed MA, Ahmad MS, Mahmoud MA
    Int J Med Inform, 2018 04;112:173-184.
    PMID: 29500017 DOI: 10.1016/j.ijmedinf.2018.02.001
    Autonomous agents are being widely used in many systems, such as ambient assisted-living systems, to perform tasks on behalf of humans. However, these systems usually operate in complex environments that entail uncertain, highly dynamic, or irregular workload. In such environments, autonomous agents tend to make decisions that lead to undesirable outcomes. In this paper, we propose a fuzzy-logic-based adjustable autonomy (FLAA) model to manage the autonomy of multi-agent systems that are operating in complex environments. This model aims to facilitate the autonomy management of agents and help them make competent autonomous decisions. The FLAA model employs fuzzy logic to quantitatively measure and distribute autonomy among several agents based on their performance. We implement and test this model in the Automated Elderly Movements Monitoring (AEMM-Care) system, which uses agents to monitor the daily movement activities of elderly users and perform fall detection and prevention tasks in a complex environment. The test results show that the FLAA model improves the accuracy and performance of these agents in detecting and preventing falls.
    Matched MeSH terms: Computer Simulation
  13. Fulltext Numerical solution of magnetohydrodynamics effects on a generalised power law fluid model of blood flow through a bifurcated artery with an overlapping shaped stenosis
    Zain NM, Ismail Z
    PLoS One, 2023;18(2):e0276576.
    PMID: 36780455 DOI: 10.1371/journal.pone.0276576
    This paper presents a numerical analysis of blood flow in a diseased vessel within the presence of an external magnetic field. The blood flow was considered to be incompressible and fully developed, in that the non-Newtonian nature of the fluid was characterised as a generalised power law model for shear-thinning, Newtonian, and shear-thickening fluids. The impact of a transverse directed external magnetic field on blood flow through a stenosed bifurcated artery was investigated. The arterial geometry was considered as a bifurcated channel with overlapping shaped stenosis. The problem was treated mathematically using the Galerkin Least-Squares (GLS) method. The implementation of this numerical method managed to overcome the numerical instability faced by the classical Galerkin technique when adopted to a highly viscous flow. The benefit of GLS in circumventing the Ladyzhenskaya-Babuška-Brezzi (LBB) condition was utilized by evaluating both the velocity and pressure components at corner nodes of a unstructured triangular element. The non-linearity that emerged from the convective terms was then treated using the Newton-Raphson method, while the numerical integrals were computed using a Gaussian quadrature rule with six quadrature points. The findings obtained from this study were then compared with available results from the literature as well as Comsol multiphysics software to verify the accuracy and validity of the numerical algorithms. It was found that the application of magnetic field was able to overcome flow reversal by 39% for a shear-thinning fluid, 26% for a Newtonian fluid, and 27% for a shear-thickening fluid. The negative pressure and steep wall shear stress which occurs at the extremities of an overlapping stenosis throat were diminished by rise in magnetic intensity. This prevented thrombosis occurrence and produced a uniform calm flow.
    Matched MeSH terms: Computer Simulation
  14. Fulltext Green communication for cognitive radio networks based on game and utility-pricing theories
    Mukhlif F, Noordin KAB, Abdulghafoor OB, Izam TFTMN
    PLoS One, 2020;15(8):e0235953.
    PMID: 32841253 DOI: 10.1371/journal.pone.0235953
    The most crucial challenge in the functioning of the wireless networks is the efficient utilization of radio resources. A significant element of resource handling is power regulation. With increasing requirement of wireless data transmission services, it is essential to devise energy harvesting techniques for mobile devices. In this research, a new methodology has been proposed for distributed power regulation in cognitive radio, networks of CR are grounded on non-cooperation game phenomenon and pricing technique. QoS (Quality of service) of the user of CR is anticipated as a beneficial activity through pricing as well as dissemination of energy generating as an unbeneficial game wherein the consumers increase their overall efficacy. The price is defined as an actual function of transmission power to upraise the pricing of the most distant consumers. The proposed mathematical model shows that the proposed game model has a Nash equilibrium and is also unique. Furthermore, in order to make the proposed algorithm valid for green communication within the wireless network, the best response technique was proposed. Finally, simulation results showed that the proposed energy harvesting technique, grounded on a unique function of the utilization, reduces the consumption of transmission power and greatly improves the convergence speed; which are suitable for the vision of the 5G networks.
    Matched MeSH terms: Computer Simulation
  15. Fulltext Engineering of Naproxen Loaded Polymer Hybrid Enteric Microspheres for Modified Release Tablets: Development, Characterization, in silico Modelling and in vivo Evaluation
    Hameed HA, Khan S, Shahid M, Ullah R, Bari A, Ali SS, et al.
    Drug Des Devel Ther, 2020;14:27-41.
    PMID: 32021089 DOI: 10.2147/DDDT.S232111
    BACKGROUND: Naproxen (NP) is a non-steroidal anti-inflammatory drug with poor aqueous solubility and low oral bioavailability, which may lead to therapeutic failure. NP causes crucial GIT irritation, bleeding, and peptic and duodenal ulcers.

    PURPOSE OF THE STUDY: This study aimed to engineer and characterize polymer hybrid enteric microspheres using an integrated (experimental and molecular modelling) approach with further development to solid dosage form with modified drug release kinetics and improved bioavailability.

    MATERIALS AND METHODS: NP loaded polymer hybrid enteric microspheres (PHE-Ms) were fabricated by using a modified solvent evaporation technique coupled with molecular modelling (MM) approach. The PHE-Ms were characterized by particle size, distribution, morphology, crystallinity, EE, drug-polymer compatibility, and DSC. The optimized NP loaded PHE-Ms were further subjected to downstream procedures including tablet dosage form development, stability studies and comparative in vitro-in vivo evaluation.

    RESULTS: The hydrophobic polymer EUD-L100 and hydrophilic polymer HPMC-E5 delayed and modified drug release at intestinal pH while imparting retardation of NP release at gastric pH to diminish the gastric side effects. The crystallinity of the NP loaded PHE-Ms was established through DSC and P (XRD). The particle size for the developed formulations of PEH-Ms (M1-M5) was in the range from 29.06 ±7.3-74.31 ± 17.7 μm with Span index values of 0.491-0.69, respectively. The produced NP hybrid microspheres demonstrated retarded drug release at pH 1.2 and improved dissolution at pH 6.8. The in vitro drug release patterns were fitted to various release kinetic models and the best-followed model was the Higuchi model with a release exponent "n" value > 0.5. Stability studies at different storage conditions confirmed stability of the NP loaded PHE-Ms based tablets (P<0.05). The molecular modelling (MM) study resulted in adequate binding energy of co-polymer complex SLS-Eudragit-HPMC-Naproxen (-3.9 kcal/mol). In contrast to the NP (unprocessed) and marketed formulations, a significant increase in the Cmax of PHE-MT1 (44.41±4.43) was observed.

    CONCLUSION: The current study concludes that developing NP loaded PHE-Ms based tablets could effectively reduce GIT consequences with restored therapeutic effects. The modified release pattern could improve the dissolution rate and enhancement of oral bioavailability. The MM study strengthens the polymer-drug relationship in microspheres.

    Matched MeSH terms: Computer Simulation
  16. Fulltext Mathematical epidemiologic and simulation modelling of first wave COVID-19 in Malaysia
    Ariffin MRK, Gopal K, Krishnarajah I, Che Ilias IS, Adam MB, Arasan J, et al.
    Sci Rep, 2021 Oct 20;11(1):20739.
    PMID: 34671103 DOI: 10.1038/s41598-021-99541-0
    Since the first coronavirus disease 2019 (COVID-19) outbreak appeared in Wuhan, mainland China on December 31, 2019, the geographical spread of the epidemic was swift. Malaysia is one of the countries that were hit substantially by the outbreak, particularly in the second wave. This study aims to simulate the infectious trend and trajectory of COVID-19 to understand the severity of the disease and determine the approximate number of days required for the trend to decline. The number of confirmed positive infectious cases [as reported by Ministry of Health, Malaysia (MOH)] were used from January 25, 2020 to March 31, 2020. This study simulated the infectious count for the same duration to assess the predictive capability of the Susceptible-Infectious-Recovered (SIR) model. The same model was used to project the simulation trajectory of confirmed positive infectious cases for 80 days from the beginning of the outbreak and extended the trajectory for another 30 days to obtain an overall picture of the severity of the disease in Malaysia. The transmission rate, β also been utilized to predict the cumulative number of infectious individuals. Using the SIR model, the simulated infectious cases count obtained was not far from the actual count. The simulated trend was able to mimic the actual count and capture the actual spikes approximately. The infectious trajectory simulation for 80 days and the extended trajectory for 110 days depicts that the inclining trend has peaked and ended and will decline towards late April 2020. Furthermore, the predicted cumulative number of infectious individuals tallies with the preparations undertaken by the MOH. The simulation indicates the severity of COVID-19 disease in Malaysia, suggesting a peak of infectiousness in mid-March 2020 and a probable decline in late April 2020. Overall, the study findings indicate that outbreak control measures such as the Movement Control Order (MCO), social distancing and increased hygienic awareness is needed to control the transmission of the outbreak in Malaysia.
    Matched MeSH terms: Computer Simulation
  17. Fulltext VSHR: A Mathematical Model for the Prediction of Second-Wave COVID-19 Epidemics in Malaysia
    Yu X, Lu L, Guo J, Qin H, Ji C
    Comput Math Methods Med, 2022;2022:4168619.
    PMID: 35087601 DOI: 10.1155/2022/4168619
    Since December 2019, a novel coronavirus (COVID-19) has spread all over the world, causing unpredictable economic losses and public fear. Although vaccines against this virus have been developed and administered for months, many countries still suffer from secondary COVID-19 infections, including the United Kingdom, France, and Malaysia. Observations of COVID-19 infections in the United Kingdom and France and their governance measures showed a certain number of similarities. A further investigation of these countries' COVID-19 transmission patterns suggested that when a turning point appeared, the values of their stringency indices per population density (PSI) were nearly proportional to their absolute infection rate (AIR). To justify our assumptions, we developed a mathematical model named VSHR to predict the COVID-19 turning point for Malaysia. VSHR was first trained on 30-day infection records prior to the United Kingdom, Germany, France, and Belgium's known turning points. It was then transferred to Malaysian COVID-19 data to predict this nation's turning point. Given the estimated AIR parameter values in 5 days, we were now able to locate the turning point's appearance on June 2nd, 2021. VSHR offered two improvements: (1) gathered countries into groups based on their SI patterns and (2) generated a model to identify the turning point for a target country within 5 days with 90% CI. Our research on COVID-19's turning point for a country is beneficial for governments and clinical systems against future COVID-19 infections.
    Matched MeSH terms: Computer Simulation
  18. Fulltext Silicene Quantum Capacitance Dependent Frequency Readout to a Label-Free Detection of DNA Hybridization- A Simulation Analysis
    Rahman MS, Naima RL, Shetu KJ, Hossain MM, Kaiser MS, Hosen ASMS, et al.
    Biosensors (Basel), 2021 Jun 01;11(6).
    PMID: 34205927 DOI: 10.3390/bios11060178
    The use of deoxyribonucleic acid (DNA) hybridization to detect disease-related gene expression is a valuable diagnostic tool. An ion-sensitive field-effect transistor (ISFET) with a graphene layer has been utilized for detecting DNA hybridization. Silicene is a two-dimensional silicon allotrope with structural properties similar to graphene. Thus, it has recently experienced intensive scientific research interest due to its unique electrical, mechanical, and sensing characteristics. In this paper, we proposed an ISFET structure with silicene and electrolyte layers for the label-free detection of DNA hybridization. When DNA hybridization occurs, it changes the ion concentration in the surface layer of the silicene and the pH level of the electrolyte solution. The process also changes the quantum capacitance of the silicene layer and the electrical properties of the ISFET device. The quantum capacitance and the corresponding resonant frequency readout of the silicene and graphene are compared. The performance evaluation found that the changes in quantum capacitance, resonant frequency, and tuning ratio indicate that the sensitivity of silicene is much more effective than graphene.
    Matched MeSH terms: Computer Simulation
  19. Fulltext Multireceptor Analysis for Evaluating the Antidiabetic Efficacy of Karanjin: A Computational Approach
    Nag S, Stany B, Mishra S, Kumar S, Mohanto S, Ahmed MG, et al.
    Endocrinol Diabetes Metab, 2024 Jul;7(4):e509.
    PMID: 38982323 DOI: 10.1002/edm2.509
    BACKGROUND: Diabetes mellitus, notably type 2, is a rising global health challenge, prompting the need for effective management strategies. Common medications such as metformin, insulin, repaglinide and sitagliptin can induce side effects like gastrointestinal disturbances, hypoglycemia, weight gain and specific organ risks. Plant-derived therapies like Karanjin from Pongamia pinnata present promising alternatives due to their historical use, holistic health benefits and potentially fewer adverse effects. This study employs in silico analysis to explore Karanjin's interactions with diabetes-associated receptors, aiming to unveil its therapeutic potential while addressing the limitations and side effects associated with conventional medications.

    METHODOLOGY: The research encompassed the selection of proteins from the Protein Data Bank (PDB), followed by structural refinement processes and optimization. Ligands such as Karanjin and standard drugs were retrieved from PubChem, followed by a comprehensive analysis of their ADMET profiling and pharmacokinetic properties. Protein-ligand interactions were evaluated through molecular docking using AutoDockTools 1.5.7, followed by the analysis of structural stability using coarse-grained simulations with CABS Flex 2.0. Molecular dynamics simulations were performed using Desmond 7.2 and the OPLS4 force field to explore how Karanjin interacts with proteins over 100 nanoseconds, focusing on the dynamics and structural stability.

    RESULTS: Karanjin, a phytochemical from Pongamia pinnata, shows superior drug candidate potential compared to common medications, offering advantages in efficacy and reduced side effects. It adheres to drug-likeness criteria and exhibits optimal ADMET properties, including moderate solubility, high gastrointestinal absorption and blood-brain barrier penetration. Molecular docking revealed Karanjin's highest binding energy against receptor 3L2M (Pig pancreatic alpha-amylase) at -9.1 kcal/mol, indicating strong efficacy potential. Molecular dynamics simulations confirmed stable ligand-protein complexes with minor fluctuations in RMSD and RMSF, suggesting robust interactions with receptors 3L2M.

    CONCLUSION: Karanjin demonstrates potential in pharmaceutical expansion for treating metabolic disorders such as diabetes, as supported by computational analysis. Prospects for Karanjin in pharmaceutical development include structural modifications for enhanced efficacy and safety. Nanoencapsulation may improve bioavailability and targeted delivery to pancreatic cells, while combination therapies could optimize treatment outcomes in diabetes management. Clinical trials and experimental studies are crucial to validate its potential as a novel therapeutic agent.

    Matched MeSH terms: Computer Simulation
  20. Fulltext Controlling the pressure of hydrogen-natural gas mixture in an inclined pipeline
    Chaharborj SS, Amin N
    PLoS One, 2020;15(2):e0228955.
    PMID: 32106248 DOI: 10.1371/journal.pone.0228955
    This paper discusses the optimal control of pressure using the zero-gradient control (ZGC) approach. It is applied for the first time in the study to control the optimal pressure of hydrogen natural gas mixture in an inclined pipeline. The solution to the flow problem is first validated with existing results using the Taylor series approximation, regression analysis and the Runge-Kutta method combined. The optimal pressure is then determined using ZGC where the optimal set points are calculated without having to solve the non-linear system of equations associated with the standard optimization problem. It is shown that the mass ratio is the more effective parameter compared to the initial pressure in controlling the maximum variation of pressure in a gas pipeline.
    Matched MeSH terms: Computer Simulation
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