266 research outputs found

    The Homology Modeling and Docking Investigation of Human Cathepsin B

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    Background: Cathepsin B comprises a group of lysosomal cysteine proteases belonging to the Papain family; it has an intracellular function in the process of protein catabolism, antigen processing in the immune response, and Alzheimer’s disease. In cancers, cathepsin B interferes with autophagy and intracellular catabolism, and breaks down extracellular matrix, decreases protease inhibitors expression, and ultimately helps to accelerate metastasis, tumor malignancy, and reduce immune resistance. Methods: In this study, the 3D structure of cathepsin B was constructed using modeler and Iterative Threading ASSEmbly Refinement (I-TASSER), based on similarity to the crystallographic model of procathepsin B (1PBH). Then, the predicted cathepsin B model was evaluated using PROCHECK and PROSA for quality and reliability. Molecular studies suggested that the amino acids cysteine 108, histidine 189, and histidine 190 form the envelope of the active site of cathepsin B. The docking studies of cathepsin B was performed with protease inhibitors cystatin C, E-64 and leupeptin. Results: The lowest binding energy was related to the cathepsin B-E-64 complex. Accordingly, it was found that E64 interacts with the amino acid cysteine 108 of the active site of cathepsin B. Leupeptin made 2 hydrogen bonds with cathepsin B, but none with the active site of cathepsin amino acids. Cystatin C established a hydrogen bond with the arginine 18 of cathepsin B and made electrostatic bonds with aspartate 148 of cathepsin B. Conclusion: Therefore, the bioinformatics and docking studies of cathepsin B with its inhibitors could be used as reliable identification, treatment, and alternative methods for selecting the inhibitors and controllers of cancer progression

    Key performance indicators for successful simulation projects

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    There are many factors that may contribute to the successful delivery of a simulation project. To provide a structured approach to assessing the impact various factors have on project success, we propose a top-down framework whereby 15 Key Performance Indicators (KPI) are developed that represent the level of successfulness of simulation projects from various perspectives. They are linked to a set of Critical Success Factors (CSF) as reported in the simulation literature. A single measure called Project’s Success Measure (PSM), which represents the project’s total success level, is proposed. The framework is tested against 9 simulation exemplar cases in healthcare and this provides support for its reliability. The results suggest that responsiveness to the customer’s needs and expectations, when compared with other factors, holds the strongest association with the overall success of simulation projects. The findings highlight some patterns about the significance of individual CSFs, and how the KPIs are used to identify problem areas in simulation projects.This study was supported by the Multidisciplinar Assessment of Technology Centre for Healthcare (MATCH) program (EPSRC Grant EP/F063822/1)

    Numerical Simulation of Flow Separation Control using Multiple DBD Plasma Actuators

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    A numerical simulation method is employed to investigate the effect of the steady multiple plasma body forces on the flow field of stalled NACA 0015 airfoil. The plasma body forces created by multiple Dielectric Barrier Discharge (DBD) actuators are modeled with a phenomenological plasma method coupled with 2-dimensional compressible turbulent flow equations. The body force distribution is assumed to vary linearly in the triangular region around the actuator. The equations are solved using adual-timeimplicit finite volume method on unstructured grids. In this paper, the responses of the separated flow field to the effects of single and multiple DBD actuators over the broad range of angles of attack ( 9^0-〖30〗^0) are studied. The effects of the actuators positions on the flow field are also investigated. It is shown that the DBD have a significant effect on flow separation control in low Reynolds number aerodynamics

    Effects of coir fibres modified with Ca(OH)2 and Mg(OH)2 nanopeprintss on mechanical properties of lime-treated marine clay

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    In this study, coir fibres were modified with nanoparticles of calcium hydroxide and magnesium hydroxide via a chemical treatment in order to increase the tensile strength of the fibres and their interaction with soil. To evaluate the modification and its effects, unconfined compressive strength tests, indirect tensile strength tests, flexural strength tests and triaxial compressive strength tests were carried out at 7, 28 and 90 days of curing age on lime-treated soil reinforced with modified and unmodified fibres. The obtained results showed that nano-modification of fibres enhanced the mechanical properties of the lime-treated clay soil due to the tensile strength of the augmented fibres. The results showed that the compressive strength, the indirect tensile strength and the flexural strength of samples treated with modified coir fibres increased by 64%, 122% and 56%, respectively compared to that of samples treated with unmodified fibres. Moreover, an increase in the effective internal friction angle and the cohesion intercept was observed. Also, the results of scanning electron microscopy and energy dispersive X-ray confirmed a desired alteration in morphology of the fibres

    Reinforcement benefits of nanomodified coir fiber in lime-treated marine clay

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    In this study, reinforcing effect of nanomodified coir fibers with ferric hydroxide, Fe(OH)3, and aluminum hydroxide, Al(OH)3, on shear strength of limed marine clay soil was investigated. Accordingly, triaxial compression strength (TCS) testing was carried out to determine the shear strength parameters of the reinforced soil. Also, wetting/drying cycle testing was conducted to assess the durability of samples. The results from the experimental investigation show that the lime and nanomodified fibers improved the shear strength and durability through the intended modification on natural coir fiber. Moreover, an increase in the effective stress internal friction angle and the cohesion intercept were observed. To confirm the morphology alteration in fibers, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) tests were performed. Nanomodification of fibers increased their tensile strength and caused a better interaction with the limed matrix by an enhanced interfacial adhesion. The tensile strength and friction at the interface was the dominant mechanism controlling the reinforcement benefit

    Key performance indicators for successful simulation projects

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    There are many factors that may contribute to the successful delivery of a simulation project. To provide a structured approach to assessing the impact various factors have on project success, we propose a top-down framework whereby 15 Key Performance Indicators (KPI) are developed that represent the level of successfulness of simulation projects from various perspectives. They are linked to a set of Critical Success Factors (CSF) as reported in the simulation literature. A single measure called Project’s Success Measure (PSM), which represents the project’s total success level, is proposed. The framework is tested against 9 simulation exemplar cases in healthcare and this provides support for its reliability. The results suggest that responsiveness to the customer’s needs and expectations, when compared with other factors, holds the strongest association with the overall success of simulation projects. The findings highlight some patterns about the significance of individual CSFs, and how the KPIs are used to identify problem areas in simulation projects

    Flow Control of Transonic Airfoils using Optimum Suction and Injection Parameters

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    In this paper, the application of the surface mass transfer optimization in shock wave-boundary layer interaction control at off-design conditions of transonic aircraft wing is presented. The suction or injection parameters include for example its position on the airfoil, its angle, the length of the hole and the rate of the injected or sucked flow. The optimization process is carried out using an efficient Genetic Algorithm (GA) method. The compressible viscous flow equations in Reynolds Averaged form are solved together with a two-equation k-epsilon turbulence model to accurately compute the objective function. Four different objective functions are introduced including maximum lift to drag ratio, minimum drag coefficient, maximum lift to drag ratio with no drag increment and minimum drag coefficient with no lift decrement. Effectiveness of each objective function is examined by comparing the optimum results in terms of the flow control parameters and flow characteristics

    Analysis of fleet type impact on the threats and errors of an airline using Line Operations Safety Audit (LOSA)

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    In this study, three Line Operations Safety Audits (LOSAs) on an airline are carried out, their results are compared with each other, and a comparison is also made between domestic and international fleets. The LOSA is a proactive and predictive method in the Safety Management System that detects the strengths and weaknesses of airline performance under normal operations. Furthermore, it is a tool to improve the safety margin. The LOSA process is implemented on the basis of ten operating characteristics. Once the data for each LOSA was gathered and processed, the results for the three were compared. Surveys show that LOSAs provide a monitoring system for the Threat and Error Management of old generation aircraft. Domestic and international airline fleets confront different types of threats and errors in different flight phases. It is concluded that the syllabuses of training courses should be different for flight crew with respect to their fleet and the threat and error types. That are most common the obtained results can promote the importance of airlines’ Threat and Error Management based on their fleet type in the future
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