68 research outputs found

    Coupling fluid and solid domains in modeling drug transport within tumor

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    Development of a feasible model for transport within complex vasculature network and tissue remains a challenge. Such a model is particularly important when considering drug transport within tumor environment. A drug used to cure the cancer is first transported through blood vessels, then it attaches to the vessel endothelium and faces biological barriers in the vessel wall to reach cancerous cells. We have developed a model for convective-diffusive drug transport which is simple and computationally efficient. One of the challenges was to couple fluid domain within blood vessels and solid domain of the tumor microenvironment. We have introduced fictitious 1D finite elements which appropriately take into account transport characteristics of the vessel walls. These characteristics include leakage and permeability of the walls. In evaluating wall permeability of a drug, we implemented our hierarchical multiscale methodology which couples molecular dynamics (MD) and continuum FE model. A numerical homogenization procedure was employed to obtain equivalent continuum transport parameters which account for interaction on molecular level between drug and solid components of the wall microstructure. Also, a possibility of using equivalent continuum transport models for capillary beds is investigated in order to further simplify and increase efficiency for the overall model of tumor. As a numerical example, we calculate transport through a capillary bed to illustrate applicability of our methodology

    COMPUTATIONAL MODELING OF INTRAOCULAR DRUG TRANSPORT

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    In this work we present computational model for intraocular drug transport using coupled convective-diffusive equations. Model can simulate drug transport using either injection or by state of the art implant devices. We are using Navier-Stokes equation for fluid flow in vitreous humor, and composite smeared finite element (CSFE) for convection in rest of the eye and also for diffusion within the whole model. CSFE takes into account blood vessel properties, such as hydraulic and diffusive components. User interface tool CAD for pre- and post- processing is constructed which enables generation of geometries for patient specific purposes. Computational model provides results in a form convenient for investigation of effects of the drugs on different diseases, such as diabetic macular edema, uveitis, etc. This computational platform has potentials to become a powerful tool for optimization of therapies and simulation of different drugs.Publishe

    Free weight training vs. elastic band training: What is a more effective strategy for increasing maximal velocity ability during handball throws?

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    The aim of this study was to assess the effectiveness of two resistance training (RT) programmes (free weight [FW] and elastic band [EB]) on velocity variables (handball throwing velocity [HTV] and maximal theoretical velocity [V0]) using load-velocity (L-V) relationship modelling. Both programmes lasted 6 weeks and consisted of performing bench press and overarm dumbbell pull-over using free weights (FW group) or elastic bands (EB group). Nineteen male sports science students were randomly assigned to EB (n=10) or FW group (n=9). Both RT programmes increased HTV and V0, although the increment was greater in the FW (>2 m·s-1) compared to the EB group (<1 m·s-1). RT programmes had selective effects on the strength variables being FW more effective in increasing 1-repetition maximum, while EB in increasing maximal isometric force. Very large correlations were observed between two-point (L-V relationship modelled through two pairs of L and V data) and multiple-point methods (L-V relationship modelled through six pairs of L and V data) (V0: r=0.96; HTV: r=0.93). All coefficients of variation showed high validity both for V0 and HTV (≤6.2%). Altogether, FW training should be used for increasing the velocity of the throwing performance, while the two-point method for following training-induced changes

    Design and Comparison of Two Web Service Based Frameworks for Parallel Evaluation of the Population in Genetic Algorithms

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    Genetic algorithms are powerful techniques for optimization of complexsystems. These methods require a large number of evaluations of candidate solutionswhich take huge CPU time. This paper introduces two web service based frameworksfor parallel evaluation of the population in genetic algorithm using the master-slavemodel. Developed frameworks can be easily incorporated into any genetic algorithm,giving a universal mechanism for distribution of individuals and collection of the eval-uation results. This concept provides parallelization of genetic algorithms on variousdistributed architectures, including multiprocessors and computing clusters. Performedtests have shown that proposed frameworks achieve signicant speedup, especially whenevaluating large-scale problems. In addition, a case study from the eld of hydrologyis presented

    Enhancing Safety: the Challenge of Foresight - ESReDA Project Group Foresight in Safety

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    This Deliverable is the result of a joint effort by experts, working in the fields of risks management, accident analysis, learning from experience and safety management. They come from 10 countries mainly from Europe and also from USA and Australia. Their expertise covers several industrial sectors. They attempted to provide useful information, both from a theoretical and a practical point of views, about "Foresight in Safety". Safety is still an ongoing issue for which a number of subjects remain under debate (e.g. is goal of safety to ensure that 'as few things as possible go wrong' or to ensure that ‘as many things as possible go right’?). Anyway, we can assume that safety is to act in a way for both the process continues to be run right and that errors and failures to not lead to a major accident. Even if "foresight in safety" is the implicit underlying goal of every practitioner in safety, the outlines of its domain remain blurred and the relevant topics associated with it have never been clearly defined. A humble ambition of this Deliverable is to display some aspects of "foresight in safety" according to the current state of practices and scientific knowledge.JRC.G.10-Knowledge for Nuclear Security and Safet

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    Measurement of the W boson polarisation in ttˉt\bar{t} events from pp collisions at s\sqrt{s} = 8 TeV in the lepton + jets channel with ATLAS

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    Measurements of top-quark pair differential cross-sections in the eμe\mu channel in pppp collisions at s=13\sqrt{s} = 13 TeV using the ATLAS detector

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    Measurement of the charge asymmetry in top-quark pair production in the lepton-plus-jets final state in pp collision data at s=8TeV\sqrt{s}=8\,\mathrm TeV{} with the ATLAS detector

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