Bioengineering Research and Development Center Bio

Kragujevac, Serbia

Bioengineering Research and Development Center Bio

Kragujevac, Serbia
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Tosovic J.,University of Kragujevac | Markovic S.,University of Kragujevac | Milenkovic D.,Bioengineering Research and Development Center Bio | Markovic Z.,State University of Novi Pazar
Journal of the Serbian Society for Computational Mechanics | Year: 2016

A comprehensive examination of the solvation enthalpies and Gibbs energies of the proton and electron in twenty solvents of different polarities was carried. Eleven quantum mechanical methods were applied in conjunction with the 6-311++G(d,p) basis set and C-PCM solvation model. It was found that different methods produce consistent values for the solvation enthalpy and Gibbs energy of the proton in all solvents, while the corresponding values for the electron are mutually notably different. The fact that the Minnesota functionals often produced inconsistent solvation enthalpy and Gibbs energy values of the electron indicates their unreliable performance without the corresponding SMD solvation model, whereas other studied methods only slightly depend on solvation models. A comparison of the results of the present investigation to those obtained by employing SMD reveals that C-PCM produces slightly more negative (less positive) solvation enthalpies and Gibbs energies of the electron, and less negative values for the proton. These results are also in accord with the literature data where the IEF-PCM solvation model was used.


Radovic M.,Bioengineering Research and Development Center Bio | Petrovic D.,Bioengineering Research and Development Center Bio | Filipovic N.,Bioengineering Research and Development Center Bio
Journal of the Serbian Society for Computational Mechanics | Year: 2012

Arterial geometry variability is present both within and across individuals. To analyze the influence of geometric parameters, blood density, dynamic viscosity and blood velocity on wall shear stress (WSS) distribution in the human carotid artery bifurcation and aneurysm, the computer simulations were run to generate the data pertaining to this phenomenon. In our work we evaluate two prediction models for modeling these relationships: neural network model and k-nearest neighbor model. The results revealed that both models have high prediction ability for this prediction task. The achieved results represent progress in assessment of stroke risk for a given patient data in real time.


Milosevic Z.,Bioengineering Research and Development Center Bio | Radovic M.,Bioengineering Research and Development Center Bio | Bird J.,University of Cambridge | Teng Z.,University of Cambridge | And 2 more authors.
Journal of the Serbian Society for Computational Mechanics | Year: 2012

Atherosclerosis is a disease of large arteries that is characterized by the accumulation of lipids in the arterial wall. Mechanical forces such as low shear stress are implicated in plaque formation and development. The objective of this work is to examine influence of wall shear stress (WSS) and histological and blood analysis data on the atherosclerosis development. Histological data and blood analysis (cholesterol, HDL, LDL and triglycerides) are available for 18 rabbits fed by atherogenic diet at Cambridge University. WSS data are calculated by using Computer Fluid Dynamic (CFD). Navier-Stokes equations and Darcy's law were main governing methods for modeling fluid dynamics in the lumen and wall. Convection diffusion equations were used for modeling LDL and oxygen transport. For coupling fluid dynamics and solute dynamics Kedem-Katchalsky equations were used. Two types of finite element model were used. Wall free models were wall is treated only as boundary condition and single layered model where intima and media of the wall is treated as one entity with homogenous transport characteristics.


Koncar I.,University of Belgrade | Sladojevic M.,University of Belgrade | Nikolic D.,Bioengineering Research and Development Center Bio | Milosevic Z.,Bioengineering Research and Development Center Bio | And 5 more authors.
2015 IEEE 15th International Conference on Bioinformatics and Bioengineering, BIBE 2015 | Year: 2015

The role of intraluminal thrombus (ILT) has special attention in these studies. One of the papers showed that asymmetrical intraluminal thrombus deposition (ATDI) has an important role in growth of the AAA. The aim of our study was to assess the asymmetrical thrombus deposition index in ruptured and symptomatic aneurysms. We collected data for 33 aneurysms, 21 (63.63%) asymptomatic and 12 (33.37%) ruptured or symptomatic. Asymmetrical thrombus deposition index (ATDI) was measured by Onis DICOM viewer software. Also, lumen's geometrical centre (LGC) was defined and ATDI was considered positive when the LGC was laid on the posterior section of the sac (meaning dominant anterior ILT distribution) and negative when it was laid on the anterior section (meaning dominant posterior ILT distribution). Maximum aneurysm diameter was 63.4mm in average (50-100mm, SD=12.89); 59.8mm in asymptomatic and 71.16mm in symptomatic or ruptured aneurysm (p=0.012). The absolute value of asymmetric thrombus deposition index was significantly higher in symptomatic/ruptured compared to asymptomatic aneurysm, 0.54 and 0.33, respectively (p=0.041), while there was no difference in frequency of positive or negative thrombus deposition (p=0.261). There was no significant correlation between maximal aneurysm size and absolute value of ATDI (p=0.505). Values of thrombus deposition index are correlating with the development of symptomatology or rupture of the AAA. This variable should be included in much wider mathematical rupture prediction model in order to have more accurate rupture risk assessment. © 2015 IEEE.


PubMed | Bioengineering Research and Development Center Bio and Temple University
Type: Journal Article | Journal: BMC bioinformatics | Year: 2017

Feature selection, aiming to identify a subset of features among a possibly large set of features that are relevant for predicting a response, is an important preprocessing step in machine learning. In gene expression studies this is not a trivial task for several reasons, including potential temporal character of data. However, most feature selection approaches developed for microarray data cannot handle multivariate temporal data without previous data flattening, which results in loss of temporal information. We propose a temporal minimum redundancy - maximum relevance (TMRMR) feature selection approach, which is able to handle multivariate temporal data without previous data flattening. In the proposed approach we compute relevance of a gene by averaging F-statistic values calculated across individual time steps, and we compute redundancy between genes by using a dynamical time warping approach.The proposed method is evaluated on three temporal gene expression datasets from human viral challenge studies. Obtained results show that the proposed method outperforms alternatives widely used in gene expression studies. In particular, the proposed method achieved improvement in accuracy in 34 out of 54 experiments, while the other methods outperformed it in no more than 4 experiments.We developed a filter-based feature selection method for temporal gene expression data based on maximum relevance and minimum redundancy criteria. The proposed method incorporates temporal information by combining relevance, which is calculated as an average F-statistic value across different time steps, with redundancy, which is calculated by employing dynamical time warping approach. As evident in our experiments, incorporating the temporal information into the feature selection process leads to selection of more discriminative features.


Filipovic N.,University of Kragujevac | Zivanovic M.,Bioengineering Research and Development Center Bio | Savic A.,Tecnalia | Bijelic G.,Tecnalia
Computer Methods in Biomechanics and Biomedical Engineering | Year: 2015

The architecture and composition of stratum corneum act as barriers and limit the diffusion of most drug molecules and ions. Much effort has been made to overcome this barrier and it can be seen that iontophoresis has shown a good effect. Iontophoresis represents the application of low electrical potential to increase the transport of drugs into and across the skin or tissue. Iontophoresis is a noninvasive drug delivery system, and therefore, it is a useful alternative to drug transportation by injection. In this study, we present a numerical model and effects of electrical potential on the drug diffusion in the buccal tissue and the stratum corneum. The initial numerical results are in good comparison with experimental observation. We demonstrate that the application of an applied voltage can greatly improve the efficacy of localized drug delivery as compared to diffusion alone. © 2015 Taylor & Francis


Radovic M.,Bioengineering Research and Development Center Bio | Radovic M.,University of Kragujevac | Milosevic Z.,Bioengineering Research and Development Center Bio | Milosevic Z.,University of Kragujevac | And 13 more authors.
ECCOMAS Special Interest Conference - SEECCM 2013: 3rd South-East European Conference on Computational Mechanics, Proceedings - An IACM Special Interest Conference | Year: 2013

Atherosclerosis is becoming the number one cause of death worldwide. Animal experiments are very important to better understand physiological conditions for atherosclerosis development. We here examined influence of wall shear stress (WSS), histological and blood analysis data on the atherosclerosis lesion development for animal model. The histological cross-sections and blood analysis (cholesterol, HDL, LDL and triglycerides) data are provided from study of 19 rabbits fed by atherogenic diet at Cambridge University, within the ARTreat project research (www.artreat.kg.ac.rs). The Navier-Stokes and continuity equations were the governing equations for modeling fluid dynamics in the lumen. Convection diffusion equations were used for modeling LDL transport. For coupling fluid dynamics and solute dynamics Kedem-Katchalsky equations were used. Four regression models: multiple regression, polynomial regression, factorial regression and response surface regression are used for fitting experimental data for the plaque size. These models showed strong correlation between plaque size and input experimental data. The results represent a progress in the assessment of stroke risk for a given patient's geometry and blood analysis data.


Isailovic V.M.,Bioengineering Research and Development Center Bio | Isailovic V.M.,University of Kragujevac | Nikolic M.M.,Bioengineering Research and Development Center Bio | Nikolic M.M.,University of Kragujevac | And 5 more authors.
2015 IEEE 15th International Conference on Bioinformatics and Bioengineering, BIBE 2015 | Year: 2015

Human hearing system in general, and particularly the cochlea, is very interesting for investigation. The most important reason for it is hearing loss - a health problem that affects a large part of the world's human population. The highest percentage of people with hearing problems are older people, but the problem also occurs in newborns. Experimental research in this area provides some information about the level of hearing loss. Therefore, it is very useful to have a numerical model of the hearing system that can significantly contribute to the understanding of the origin of the mentioned health problem. Two numerical models are developed to investigate hearing problems: passive 3D cochlea model and 2D cochlea cross-section model. Those models are weakly coupled in order to make an active cochlea model [1]. © 2015 IEEE.


Mijailovic N.,University of Kragujevac | Radakovic R.,Bioengineering Research and Development Center Bio | Peulic A.,University of Kragujevac | Milankovic I.,University of Kragujevac | Filipovic N.,University of Kragujevac
2015 IEEE 15th International Conference on Bioinformatics and Bioengineering, BIBE 2015 | Year: 2015

In this paper the methodology of vertical jump analysis is presented. Measured results of vertical force during jump are presented. Six subjects (members of "Red star" football club) perform different types of jump (flywheel jump, jump without flywheel, and jump with landing on the left and right foot while vertical ground reaction force is measured using a force plate. One axial load cell force sensor is also used. The measure value of force and position of a body part is used together with finite element method simulation in order to obtain von Mises stress distribution on the tibia, femur and cartilage in the knee joint. The average value of von Mises stress has a significant impact on the injuries and condition of the knee cartilage. © 2015 IEEE.


Nikolic D.,Bioengineering Research and Development Center Bio | Matovic M.,University of Kragujevac | Jeremic M.,University of Kragujevac | Cvetkovic A.,University of Kragujevac | And 3 more authors.
2015 IEEE 15th International Conference on Bioinformatics and Bioengineering, BIBE 2015 | Year: 2015

Hybrid imaging combining CT and SPECT is becoming a state of the art nuclear medicine technique. Advantages of hybrid imaging are improved quality of the images using CT data for attenuation correction based on true transmission density data in an individual patient, and CT and SPECT fusion images providing accurate localization of the tracer uptake. Accurate localization of increased tracer uptake is very important especially in the diagnostic of tumors. For this purpose a software developed for generating 3D models from standard DICOM images, obtained from CT and SPECT, and then merging these 3D objects, provides us with the exact location of sentinels nodes. This is certainly very helpful for a surgeon performing biopsy. The ability of SPECT/CT to improve diagnostic accuracy, especially specificity, has a great potential in further development of nuclear medicine techniques in evaluation of tumors. © 2015 IEEE.

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