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Belgrade, Serbia

The University of Belgrade is the oldest and largest university in Serbia.Founded in 1808 as the Belgrade Higher School in revolutionary Serbia, by 1838 it merged with the Kragujevac-based departments into a single university. The University has nearly 90,000 students and over 4,200 members of teaching staff. Since its founding, the University has educated more than 330,000 bachelors, around 21,300 magisters, 29,000 specialists and 12,600 doctors. The University comprises 31 faculties, 11 research institutes, the university library, and 7 university centres. The faculties are organized into 4 groups: social science and humanities; medical science; natural science and mathematics; and technological science.The University of Belgrade has found its place amongst the top 400 universities in the world, according to the most recent global ranking carried out by the Shanghai List. In the area of mathematics, it is ranked among the top 150 universities in the world. Wikipedia.

Tulic C.,University of Belgrade
European cytokine network | Year: 2011

The aim of the study was to correlate the preoperative activity of Th1 and Th17 cytokine axes with the development of sepsis after radical cystectomy. The study involved twenty patients with the infiltrative transitional cell carcinoma of the urinary bladder without previous radiotherapy/chemotherapy, who underwent open radical cystectomy with urinary diversion. Preoperative plasma concentrations of Th1 cytokines interleukin 12 (IL-12) and interferon gamma (IFN-γ), and Th17 cytokines IL-23 and IL-17, were measured using ELISA. Preoperative expression of mRNA for IL-12p35, IFN-γ, IL-23p19 and IL-17 was quantified by real-time RT-PCR using mRNA extracted from peripheral blood mononuclear cells. Eight patients developed postoperative sepsis, diagnosed within two weeks post-operation as systemic inflammatory response syndrome in the presence of local or systemic infection. The preoperative basal plasma concentrations of Th1 and Th17 cytokines were slightly above the detection limits, with a tendency toward lower concentrations in patients who developed sepsis, but the difference was not significant (p>0.05). The preoperative expression of mRNA encoding IL-12p35 and IL-17 was significantly lower in patients who developed sepsis (p=0.003 and p=0.028, respectively). The similar trend was observed for IL-23p19 and IFN-γ, but the differences did not reach the statistical significance (p=0.051 and p=0.172, respectively). These data suggest that determination of preoperative Th1 and Th17 cytokine mRNA levels might be useful in predicting sepsis development after radical cystectomy.

The intersystem crossing rate from the lowest singlet to the lowest triplet state of thymine was studied by means of ab initio methods. The rate was calculated employing the timedependent approach based on the correlation function. The normal modes of the singlet and triplet electronic states are related by the Duschinsky transformation, i.e. by rotation and translation. The correlation function was calculated using the Condon approximation for the spin-orbit matrix element and harmonic approximation for the nuclear motion. The intersystem crossing rate strongly depends on the singlet-triplet adiabatic energy gap and on the normal mode mixing.

Bolzon G.,Polytechnic of Milan | Buljak V.,University of Belgrade
Computational Mechanics | Year: 2011

Parametric studies and identification problems require to perform repeated analyses, where only a few input parameters are varied among those defining the problem of interest, often associated to complex numerical simulations. In fact, physical phenomena relevant to several practical applications involve coupled material and geometry non-linearities. In these situations, accurate but expensive computations, usually carried out by the finite element method, may be replaced by numerical procedures based on proper orthogonal decomposition combined with radial basis function interpolation. Besides drastically reducing computing times and costs, this approach is capable of retaining the essential features of the considered system responses while filtering most disturbances. These features are illustrated in this paper with specific reference to some elastic-plastic problems. The presented results can however be easily extended to other meaningful engineering situations. © 2011 Springer-Verlag.

Nicolin A.I.,Horia Hulubei National Institute of Physics and Nuclear Engineering | Raportaru M.C.,Horia Hulubei National Institute of Physics and Nuclear Engineering | Balaz A.,University of Belgrade
Romanian Reports in Physics | Year: 2015

In the first part of this article we briefly overview the fundamentals of Bose-Einstein condensation and survey a series of results concerning the effective equations which describe the dynamics of elongated and oblate Bose-Einstein condensates. In the second part of the paper we show how one can construct effective one- and two-dimensional polynomial Schr¨odinger equations which describe the longitudinal (transversal) dynamics of high-density cigar-shaped (pancake-shaped) Bose-Einstein condensates. These equations do not account for the interplay between the radial and the transversal modes of the condensate, but can accurately describe the dynamics of effectively longitudinal (transversal) nonlinear waveforms through the rescaled effective nonlinearity in the case of cigar-shaped (pancake-shaped) condensates. © 2015, Editura Academiei Romane. All rights reserved.

As the number of end-of-life vehicles (ELVs) is estimated to increase to 79.3 million units per year by 2020 (e.g., 40 million units were generated in 2010), there is strong motivation to effectively manage this fast-growing waste flow. Intensive work on management of ELVs is necessary in order to more successfully tackle this important environmental challenge. This paper proposes an interval-parameter chance-constraint programming model for end-of-life vehicles management under rigorous environmental regulations. The proposed model can incorporate various uncertainty information in the modeling process. The complex relationships between different ELV management sub-systems are successfully addressed. Particularly, the formulated model can help identify optimal patterns of procurement from multiple sources of ELV supply, production and inventory planning in multiple vehicle recycling factories, and allocation of sorted material flows to multiple final destinations under rigorous environmental regulations. A case study is conducted in order to demonstrate the potentials and applicability of the proposed model. Various constraint-violation probability levels are examined in detail. Influences of parameter uncertainty on model solutions are thoroughly investigated. Useful solutions for the management of ELVs are obtained under different probabilities of violating system constraints. The formulated model is able to tackle a hard, uncertainty existing ELV management problem. The presented model has advantages in providing bases for determining long-term ELV management plans with desired compromises between economic efficiency of vehicle recycling system and system-reliability considerations. The results are helpful for supporting generation and improvement of ELV management plans. © 2016 Elsevier Ltd.

Andelic N.M.,University of Belgrade
FME Transactions | Year: 2012

The main purpose of this paper is to present one approach to the optimization of thin-walled I, Z and channel-section beams subjected to constrained torsion. The displacement constraints are introduced: allowable angle of twist and allowable angle of twist per unit length. The area of the cross-section is assumed to be the objective function. Applying the Lagrange multiplier method, the equations whose solutions represent the optimal values of the ratios of the parts of the chosen cross-sections are derived. © Faculty of Mechanical Engineering, Belgrade.

Jankovic M.,University of Belgrade | Jankovic M.,Institute for the Application of Nuclear Energy
Journal of Medical Biochemistry | Year: 2011

Protein glycosylation is a ubiquitous and complex co- and post-translational modification leading to glycan formation, i.e. oligosaccharide chains covalently attached to peptide backbones. The significance of changes in glycosylation for the beginning, progress and outcome of different human diseases is widely recognized. Thus, glycans are considered as unique structures to diagnose, predict susceptibility to and monitor the progression of disease. In the «omics» era, the glycome, a glycan analogue of the proteome and genome, holds considerable promise as a source of new biomarkers. In the design of a strategy for biomarker discovery, new principles and platforms for the analysis of relatively small amounts of numerous glycoproteins are needed. Emerging glycomics technologies comprising different types of mass spectrometry and affinity-based arrays are next in line to deliver new analytical procedures in the field of biomarkers. Screening different types of glycomolecules, selection of differentially expressed components, their enrichment and purification or identification are the most challenging parts of experimental and clinical glycoproteomics. This requires large-scale technologies enabling high sensitivity, proper standardization and validation of the methods to be used. Further progress in the field of applied glycoscience requires an integrated systematic approach in order to explore properly all opportunities for disease diagnosis.

This paper analyzes a class of nonconservative systems, whose Lagrangian equations can be reduced to Euler-Lagrangian equations by introducing a new Lagrangian, which is equal to a product of some function of time f (t) and the primary Lagrangian. These equations formally have the same form as for the systems with potential forces, while the influence of nonconservative forces is contained in the factor f (t), and such systems are called pseudoconservative. It is further shown that the requirement for a nonconservative system to be considered as a pseudoconservative is the existence of at least one particular solution of a system of differential equations with unknown function f (t), or their linear combination with suitably chosen multipliers. Further on, the energy relations and corresponding conservation laws of those systems are analyzed from two aspects: directly, on the basis of the corresponding Lagrangian equations and via modified Emmy Noether's theorem. So, it has been shown, even in two different ways, that there are two types of the integrals of motion, in the form of the product of an exponential factor and the sum of the generalized energy (energy function) and an additional term. For the existence of these integrals of motion, it is necessary and sufficient that there exists at least one particular solution of a partial differential equation, which is in accordance with the Lagrangian equations for the observed problem. The obtained results are equivalent to so-called energy-like conservation laws, obtained via Vujanovíc-Djukíc's generalized Noether's theorem for nonconservative systems (Vujanovíc and Jones in: VariationalMethods in Nonconservative Phenomena (monograph). Acad. Press, Boston, 1989). © 2012 Springer-Verlag.

Nesic A.D.,Institute IMTEL | Nesic D.A.,University of Belgrade
IEEE Antennas and Wireless Propagation Letters | Year: 2012

A new type of printed millimeter planar antenna with circular polarization for 60-GHz range is proposed. Radiation elements with two open tape rings are arranged in a two-dimensional 8 × 8 antenna array. Feeding is synphase network with tapered symmetrical (balanced) microstrip in the same plane as the radiation elements. The 8×8 array is fabricated in the conventional technology. To test reproducibility, three samples are fabricated. Measured $S 11 (VSWR), gain, and axial ratio (AR) are very good and in very good agreement between all three samples: AR <3 dB about 25% and gain near 20 dBi. © 2011 IEEE.

This article discusses current problems in rural Serbia and investigates development opportunities. The intention is to indicate strengths and weaknesses of the present situation and to highlight possible solutions for sustainable development. The results were presented in the form of potential methods for future development and are discussed through several issues: sustainable regional development and sustainable rural development as an alternative to excessive urbanization; cultivating the tradition of the village and development of rural tourism; cultural heritage in the service of sustainable development; building the ecological image of the village through promotion of the local economy and organic farming; and social capital and infrastructure development as factors of sustainable development. The conclusion is that in planning the development of rural areas, villages should be seen as a value and their potentials and regional characteristics should be promoted and used in order to contribute to sustainable development.

Tadic M.,University of Belgrade | Cuspidi C.,University of Milan Bicocca
Clinical Cardiology | Year: 2013

Metabolic syndrome represents a cluster of atherogenic risk factors including hypertension, insulin resistance, obesity, and dyslipidemia. Considering that all of these risk factors could influence the development of atrial fibrillation, an association between atrial fibrillation and the metabolic syndrome has been suggested. Additionally, oxidative stress and inflammation have been involved in the pathogenesis of both metabolic syndrome and atrial fibrillation. The mechanisms that relate metabolic syndrome to the increased risk of atrial fibrillation occurrence are not completely understood. Metabolic syndrome and atrial fibrillation are associated with increased cardiovascular morbidity and mortality. Because atrial fibrillation is the most common arrhythmia, and along with the prevalence of metabolic syndrome constantly increasing, it would be very important to determine the relationship between these 2 entities, especially due to the fact that the risk factors of metabolic syndrome are mainly correctable. This review focused on the available evidence supporting the association between metabolic syndrome components and metabolic syndrome as a clinical entity with atrial fibrillation. © 2013 Wiley Periodicals, Inc.

Zidverc-Trajkovic J.,University of Belgrade | Zidverc-Trajkovic J.,Headache Center
Headache | Year: 2013

Background According to the International Classification of Headache Disorders diagnostic criteria, the differences between migraine and cluster headache (CH) are clear. In addition to headache attack duration and pain characteristics, the symptoms accompanying headache represent the key features in a differential diagnosis of these 2 primary headache disorders. Just a few studies of patients with CH exist examining the presence of nausea, vomiting, photophobia, phonophobia, and aura, the features commonly accompanying migraine headache. The aim of this study was to determine the presence of migraine-like features (MF) in patients with CH and establish the significance of these phenomena related to other clinical features and response to treatment. Methods One hundred and fifty-five patients with CH were studied, and 24.5% of them experienced at least one of MF during every CH attack. Nausea and vomiting were the most frequently reported MF. The clinical presentation between CH patients with and without MF was not significantly different with the exception of aggravation of pain by effort (20.6% vs 4.1%) and facial sweating (13.2% vs 0.85%), both more frequent in CH patients with MF. Conclusion Inferred from the results of our study, the presence of MF in CH patients had no important influence on the diagnosis and treatment of CH patients. The major differences of these 2 primary headache disorders, attack duration, lateralization, and the nature of associated symptoms, as delineated in the International Classification of Headache Disorders, are still useful tools for effective diagnosis. © 2013 American Headache Society.

Dobardzic A.,University of Belgrade | Prodanovic T.,University of Novi Sad
Astrophysical Journal | Year: 2014

For more than a decade now, the complete origin of the diffuse gamma-ray emission background (EGRB) has been unknown. Major components like unresolved star-forming galaxies (making ≲ 50% of the EGRB) and blazars (≲ 23%), have failed to explain the entire background observed by Fermi. Another, though subdominant, contribution is expected to come from the process of large-scale structure formation. The growth of structures is accompanied by accretion and merger shocks, which would, with at least some magnetic field present, give rise to a population of structure-formation cosmic rays (SFCRs). Though expected, this cosmic-ray population is still hypothetical and only very weak limits have been placed to their contribution to the EGRB. The most promising insight into SFCRs was expected to come from Fermi-LAT observations of clusters of galaxies, however, only upper limits and no detection have been placed. Here, we build a model of gamma-ray emission from large-scale accretion shocks implementing a source evolution calibrated with the Fermi-LAT cluster observation limits. Though our limits to the SFCR gamma-ray emission are weak (above the observed EGRB) in some cases, in others, some of our models can provide a good fit to the observed EGRB. More importantly, we show that these large-scale shocks could still give an important contribution to the EGRB, especially at high energies. Future detections of cluster gamma-ray emission would help place tighter constraints on our models and give us a better insight into large-scale shocks forming around them. © 2014. The American Astronomical Society. All rights reserved..

Drulovic J.,University of Belgrade
Disability and rehabilitation | Year: 2013

The aim of our study was to investigate the impact of a short-term inpatient rehabilitation program on fatigue in patients with multiple sclerosis (MS) and to assess whether the scales of Multiple Sclerosis Quality of Life 54 (MSQoL-54) could predict change in fatigue after rehabilitation. Included in the study were 151 moderately disabled MS patients admitted for 3 weeks of inpatient rehabilitation. Fatigue (Fatigue Severity Scale; FSS) was assessed at baseline and after treatment, and quality of life (MSQoL-54), disability (Expanded Disability Status Scale; EDSS) and depression (Beck Depression Inventory; BDI) were estimated at baseline. Sixty-four percentage of the subjects showed fatigue. Both EDSS (r = 0.720, p = 0.001) and BDI (r = 0.655, p = 0.001) scores showed statistically significant positive correlation with FSS scores. Significant negative correlation was demonstrated between FSS and both, Physical Health Composite (PHC) and Mental Health Composite (MHC) scores of MSQoL-54 (r = -0.770, p = 0.001, and r = -0.646, p = 0.001, respectively). The mean FSS score significantly decreased by 0.19 ± 0.29 points in the fatigue group, immediately after rehabilitation. The multiple regression analyses with change of FSS as dependent variable and baseline scores of MSQoL-54 as independent variables showed statistically significant relation between change in fatigue and baseline PHC score (p = 0.034). Inpatient rehabilitation decreased MS patients' fatigue. Change in fatigue was predicted with certain domains of QoL at baseline.

Grozdanov T.P.,University of Belgrade | Solov'Ev E.A.,Joint Institute for Nuclear Research
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

The concept of dynamical adiabatic states, originally proposed to describe one-electron atom(ion)-ion collision systems is developed and the properties of the corresponding dynamical adiabatic potential energy curves are studied for a complete range of internuclear separations R. The advantages of a dynamical adiabatic basis are threefold. First, it is compatible with the boundary conditions, whereas in standard adiabatic two-Coulomb center basis we have nonvanishing inelastic transitions when internuclear distance R→∞. Second, rotational transitions are transformed into radial transitions via a type of hidden crossings in contrast with the standard adiabatic basis, where these transitions could only be included by numerical close-coupling calculations. And third, the ionization process can be described using a basis of the complete discrete orthogonal wave packets, which is much more satisfactory for the process compared with the standard adiabatic approach where the continuum states which have no direct physical meaning are employed. Results of the calculation for the (HeH)2+ quasimolecular system are presented and discussed. Comparison is made with previous results derived by perturbation theory in the united-atom and separated atoms limits. © 2013 American Physical Society.

The kinetic process of isothermal curing of an unsaturated polyester resin samples has been studied. The differential isoconversional method is used to yield dependency of the apparent activation energy, Ea, on the degree of cure. It was found that the dependence of Ea on α is complex, but in the conversion range α=0.10-0.50, Ea is practically constant. It was found that the gelling stage of curing process is mainly controlled chemically which can be best described by two-parameter autocatalytic model. At higher values of α, when vitrification point is reached, the change in rate-limiting step was observed. As the consequence of shifting effect from the kinetics to diffusion control, the kinetic law equation is modified with additional diffusion term. It was found that the experimentally obtained density distribution function of the apparent activation energy can be approximate by unbalanced modified Gaussian distribution function with quite satisfactory precision. © 2010 Elsevier B.V.

Ribic A.I.,Institute Mihajlo Pupin | Matausek M.R.,University of Belgrade
Journal of Process Control | Year: 2014

In the presence of rate constraints in actuator, design of cascade controller based on the primary controller conditional integration can result into closed-loop system oscillations. Stability analysis, performed by the describing function technique and confirmed by simulation, demonstrates that the solution based on the Anti-Reset Windup Cascade Control System (ARW CCS) structure is successful. Design and tuning of the ARW CCS secondary controller is a standard ARW single-input single-output problem. In the present paper tuning is proposed for the ARW CCS primary controller. For the serial process modeling simple rules are derived and confirmed by experimental results, obtained on a drum type boiler of a 210 MWe lignite coal fired unit. General design of the ARW CCS is based on the parallel process modeling and optimization of the primary controller. Optimization is performed in the frequency domain, under constraints on the maximum sensitivity, multiplicative uncertainty bound and sensitivity to measurement noise. Simulation and experimental results on a laboratory thermal plant demonstrate effectiveness of the proposed optimization. © 2014 Elsevier Ltd. All rights reserved.

Jankovic B.,University of Belgrade
Carbohydrate Polymers | Year: 2013

Detailed kinetic analysis of Cassava starch thermo-oxidative degradation was performed, using thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) at four different heating rates. It was found that degradation process is very complex, as identified through continuous change of apparent activation energy with degree of degradation. It was established that process proceeds through three main degradation stages with one additional sub-stage attached to the second degradation stage, which was detected by appearance of "shoulder" on DTG curves. It was found that most important degradation stage can be described by "lumped" model, which implies that free radicals simultaneously attack both linear and branched molecular forms of the starch. This is characterized by an unusually high value of obtained reaction order (n = 3.49). Application of nonlinear least squares method was confirmed the reliability of evaluated kinetic parameters and function of reaction mechanism, which were derived on the basis of other kinetic methods. © 2013 Elsevier Ltd. All rights reserved.

Kaludjerovic-Radoicic T.,University of Belgrade | Raicevic S.,Vinca Institute of Nuclear Sciences
Chemical Engineering Journal | Year: 2010

Natural apatites represent a cost effective soil amendment, which can be used for in situ reduction of lead bioavailability and mobility. In our previous work, we selected Lisina apatite (LA) as a promising natural mineral for lead immobilization based on theoretical predictions. This study investigated the adsorption equilibrium and kinetics of aqueous Pb sorption onto Lisina apatite and synthetic hydroxyapatite (HAP) at different temperatures. XRD analysis indicated that LA consists of three minerals: fluorapatite, quartz and muscovite. After reaction with a Pb solution, only FA peaks were changed, confirming that fluorapatite present in LA is responsible for Pb sorption. Sorption experiments confirmed that both LA and HAP are effective in Pb removal. Langmuir, Freundlich, Temkin, Koble-Corrigan and Redlich-Peterson isotherm models were applied to experimental data. The kinetics of the sorption process on both minerals was well characterized by the pseudo-second order reaction rate. Results indicate that Pb immobilization by HAP is a two-step process: the first rapid phase, possibly surface complexation and secondary dissolution of HAP and precipitation of pyromorphite. The sorption of Pb by Lisina apatite is also a two-step process, but the reaction mechanisms are more complicated and need further research as the results indicate that different mechanisms dominate at different temperatures. The values of thermodynamic equilibrium constants and Gibbs free energy were also calculated. The values of ΔG0 obtained confirm the feasibility of both HAP and LA as effective sorbents of the Pb ion. © 2010 Elsevier B.V.

Cvetkovic N.J.,Regional Museum of Jagodina | Dimitrijevic V.M.,University of Belgrade
Quaternary International | Year: 2014

Cave bear remains are known from 36 caves and other karst features, and from one open-air site in Serbia. The sites vary greatly by their morphology and size, position, altitude, stratigraphy and diversity of the fossil fauna. The cave bear stands out as a dominant species at the majority of the sites; at a number of sites it is the single species found. There are only few sites where herbivores' or predators' remains exceed those of the cave bears. The majority of cave bear remains originate from the Late Pleistocene deposits. Previously, they have been identified as Ursus spelaeus.We present a morphology and metric study of cave bears from three sites: two recently discovered localities of Middle Pleistocene age, and the Risovača cave, which may be regarded as the reference site for the Late Pleistocene mammals in the region based on a large number of collected remains and published data. The remains of the Middle Pleistocene spelaeoid bears are described from Mala Balanica cave (Eastern Serbia) and an open-air site at Ruma brickyard (Northern Serbia) for the first time. Considering the size and morphology of cheek teeth and metapodial bones, these cave bears are identified as Ursus spelaeus deningeroides. The cheek teeth morphology and size, as well as metapodial bones' metric, relate the cave bear from the Risovača cave to the advanced evolutive type of the cave bear established in Central and Eastern Europe Ursus spelaeus ingressus. © 2013 Elsevier Ltd and INQUA.

Colovic M.B.,Vinca Institute of Nuclear Sciences | Krstic D.Z.,University of Belgrade | Lazarevic-Pasti T.D.,Vinca Institute of Nuclear Sciences | Bondzic A.M.,Vinca Institute of Nuclear Sciences | Vasic V.M.,Vinca Institute of Nuclear Sciences
Current Neuropharmacology | Year: 2013

Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer's disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases. ©2013 Bentham Science Publishers.

Vucic V.,University of Belgrade
Serbian Journal of Experimental and Clinical Research | Year: 2013

Low-grade systemic infl ammation is at the base of the most chronic non-communicable diseases, which are reaching epidemic proportions worldwide. Key players in the regulation of infl ammation are n-6 and n-3 polyunsaturated fatty acids (PUFAs), in particular arachidonic acid (n-6) and eicosapentaenoic acid (n-3). They are precursors of eicosanoids-signaling molecules involved in modulating the intensity and duration of infl ammatory responses. Eicosanoids derived from n-6 PUFAs have proinfl ammatory actions, while those derived from n-3 PUFAs act anti-infl ammatory. Therefore, dietary intake of n-6 and n-3 PUFAs, as well as their ratio, could markedly affect the pathogenesis and manifestation of many chronic diseases associated with low-grade infl ammation. This review will focus on the relationship between dietary PUFAs and infl ammation, with reference to PUFAs status in plasma phospholipids in Serbian population.

Suvakov M.,University of Belgrade | Shibayama M.,Osaka University | Shibayama M.,Kyoto University
Celestial Mechanics and Dynamical Astronomy | Year: 2016

Choreographies are periodic orbits in which all bodies move on the same trajectory with equal time delay. The best known three-body choreography is figure-eight orbit. Here we introduce a search method specialized for choreographies and present three new orbits with vanishing angular momentum that are the first clear examples of choreographies that cannot be described as k-th powers of the figure-eight solution, according to the topological classification of orbits. We have also found 17 new “powers of the eight” choreographies. According to our numerical computation, one of two distinct (Formula presented.) choreographies is linearly stable. © 2015, Springer Science+Business Media Dordrecht.

Bayesian inference was used to test the powdered cellulose pyrolysis, under the isothermal experimental conditions. A completely new procedure that was based on obtaining the reliable distribution functions of the effective (apparent) activation energy (Ea) values by the statistical derivation of prior and posterior functions was introduced. It has been found that the pyrolysis of the powdered cellulose can be described by the kinetics, which differs from the first-order model. It was established that the apparent activation energy value presented as average magnitude in the conversion fraction range of 0.20 ≤ α ≤ 0.65 does not represent the “lumped” kinetic parameter, so in indicated conversion range, the pyrolysis process can be described through single-step reaction model with six-eighths-order (n* = 0.75) kinetics. Based on the presented Bayesian inference results, it was assumed that mechanism of pyrolysis takes place through the decomposition reactions which start from the cellulose chains. From the main characteristics of the prior distribution, relationship between the ingredients of Bayesian inference and the cellulose characteristic energy constant (c) [which is related to the rigidity angle (ψ) as a measure of tenseness of the cellulose chains] has been established in this paper. Based on evaluated prior and posterior distributions and their characteristics, it was found that the pyrolysis process of powdered cellulose takes place probably through formation of levoglucosan, where depolymerization represents the primary reaction path. Bayesian approach can be applied to highly structured reaction systems and complex physico-chemical processes, which include the reactivity distribution of various energy counterparts, which has been often un-tractable by traditional statistical access. © 2015, Springer Science+Business Media Dordrecht.

Maluckov B.S.,University of Belgrade
JOM | Year: 2015

Bioassisted phytomining implies targeted use of microorganisms and plants for the selective recovery of the metal. Metals from undissolved compounds are dissolved by applying specially chosen microorganisms and therefore become available to the hyperaccumulating plants. In the article, the selective extraction method of base metals and the precious metal gold by using microorganisms and plants is discussed. © 2015 The Minerals, Metals & Materials Society.

In the present study the SHETRAN river basin modelling system was used in conjunction with Geographic Information System (GIS) to estimate potential erosion and deposition rates within the catchment and the concentrations of sediment in a flow at the catchment outlet on the example of the 114.31 km2 mountainous torrential Lukovska River catchment in Serbia. The streams in the Lukovska River catchment are short, steep and often produce hazardous torrential floods as a consequence of strong rainfall of short duration. The soil erosion and sediment discharge were analysed in view of the catchment response to physical characteristics of the catchment. Considering that the most of total annual sediment discharge in watersheds of torrential character is achieved during storm events, the SHETRAN modelling system was calibrated on the example of a storm event in 1986 and validated for three other storm events in 1974, 1976 and 1979. The simulated results of discharges and sediment concentrations at the catchment outlet for both calibration and validation events were compared with the observed data and found to be reasonable. The changes of erosion and deposition rates within the catchment and in the course of time were estimated for the calibration event in 1986. The simulated erosion rates were within the range of 1 to 10.5 t/ha and corresponded to the observed rates of erosion in Europe during extreme rain events. The presented methodology is useful in identifying the erosion vulnerable regions in a catchment where erosion control measures should be implemented. © 2014, Springer Science+Business Media Dordrecht.

Bogaczyk M.,University of Greifswald | Sretenovic G.B.,University of Belgrade | Wagnerl H.-E.,University of Greifswald
European Physical Journal D | Year: 2013

For the investigation of a barrier discharge (BD) operated in helium, a discharge cell configuration was used which allows an electrical characterization and simultaneous measurements of volume processes as well as the interaction of the BD with a dielectric surface. The emission development in the volume has been recorded spatio-temporally and spectrally resolved by the established cross-correlation spectroscopy (CCS) operating in the PPG mode. The phase resolved measurement (over one discharge period) of surface charges deposited on a BSO crystal was realized by the utilization of the electro-optic Pockels effect in combination with a high-speed camera. Depending on the gap distance, the dielectrics, and the shape of feeding voltage, the BD can operate either in the diffuse Townsend-like or glow-like mode. The emission is localized near the anode and cathode for the Townsend-like mode and glow-like mode, respectively. In small gaps (distance about 1mm), a sinusoidal feeding voltage leads to the unusual Townsend-like mode in helium. But, a square wave voltage shape induces the glow-like mode, probably due to the fast rise and fall time of the applied voltage slopes. A sawtooth voltage generates both discharge modes over one period. The presented results show clearly the correlation of the emission development with electrical measurements, and deposited surface charge and transported charges. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2013.

Tomi S.,University of Salford | Vukmirovic N.,University of Belgrade
Journal of Applied Physics | Year: 2011

The role of interfaces and higher bands on the electronic structure of embedded semiconductor quantum dots (QDs) was investigated. The term in the multiband kp Hamiltonian that captures the effect of interface band mixing was derived starting from the microscopic theory. It was shown, analytically and numerically, that, with such a term included, the right symmetry of the QD system can be captured. It leads to splitting of otherwise degenerate energy levels of the order of several meV. The inclusion of additional higher bands beyond the ones from the standard eight-band model also leads to the reduction of symmetry from an artificially high one to the true atomistic symmetry of the system, however their quantitative effect is weaker. These results prove that the multiband kp Hamiltonians are fully capable of describing the correct symmetry of a QD. © 2011 American Institute of Physics.

Krstajic P.M.,University of Belgrade | Krstajic P.M.,University of Antwerp | Peeters F.M.,University of Antwerp
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

The Coulomb interaction and the correlation of a remote electron with a single layer of graphene is investigated in the presence of a magnetic field applied perpendicular to the graphene layer. The remote electron polarizes the electron gas in the graphene layer, which we describe in terms of excitations of virtual plasmons in graphene. The composite quasiparticle formed by electron plus polarization is called a plasmon polaron. The ground-state energy of this quasiparticle is calculated within perturbation theory for remote electrons in different environments. © 2012 American Physical Society.

Gligorijevic V.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2010

To evaluate the role of pelvic MRI in diagnosis and assesment of combined surgical and infliximab treatment of perianal Crohn's disease (PACD). 24 patients with signs of PACD were prospectively evaluated. They were previously treated with azathyoprin for a period of 6 months to 7 years and antibiotics and than started on Infliximab 5 mg/kg (IFX) at 0, 2 and 6 weeks induction protocol. Luminal CD activity was assesed by colonoscopy. Perianal Disease Activity Index (PDAI) was calculated to evaluate perianal fistulae activity. Surgical examination under anesthesia (EUA) was performed and non-cutting seton placed where appropriate. Pelvic MRI was performed in each patient before Infliximab treatment, and in half of the patients after IFX. MRI criteria were used to asses activity and remission of PACD. 14/24 (58.5%) patients had ileocolitis, 10/24 (41.5%) colitis, and in 22/24 (91.7%) rectum was affected. Median disease duration was 5.5 +/- 2.5 years. MRI revealed simple fistula in 4/24 (16.7%) and complex fistula in 20/24 (83.3%) patients. Abscess was present in 19/24 (79%) patients. Enterocutaneous and recto-vaginal fistula was found in 2 (8.3%) and 3 (12.5%) patients, respectively. Median PDAI before and 8 weeks after IFX treatment was 8.3 +/- 2.08 and 3.5 +/- 1.03, respectively (p = 0.00064). Incomplete response (reduction fistulae drainage by 50%) was found in 10/24 (42%) patients, complete response (no drainage) in 11/24 (46%) patients, while in 3/24 (12.5%) new fistula opened. Control pelvic MRI was performed in 13/24 (54%) patients. Of those, 9/13 (69%) had complete remission according to MRI criteria. Seton was removed after second IFX dose in 15/24 (62.5%) patients and placed again in 2/24 (8%) patients 4 months after completion of IFX treatment. In patients with PACD, pelvic MRI before and after IFX treatment is an important diagnostic tool to asses fistula tract localisation, reveal abscess, planning adequate treatment approach and assess the effect of treatment. Surgical decision to remove seton was in accordance with MRI criteria for remission in PACD.

Bankovic M.,University of Belgrade
Artificial Intelligence Review | Year: 2016

The usual approach in parallelizing SAT and SMT solvers is either to explore different parts of the search space in parallel (divide-and-conquer approach) or to run multiple instances of the same solver with suitably altered parameters in parallel, possibly exchanging some information during the solving process (parallel portfolio approach). Quite a different approach is to parallelize the execution of time-consuming algorithms that check for satisfiability and propagations during the search space exploration. Since most of the execution time is spent in these procedures, their efficient parallelization might be a promising research direction. In this paper we present our experience in parallelizing the simplex algorithm which is typically used in the SMT context to check the satisfiability of linear arithmetic constraints. We provide a detailed description of this approach and present experimental results that evaluate the potential of the approach compared to the parallel portfolio approach. We also consider the combination of the two approaches. © 2016 Springer Science+Business Media Dordrecht

Orlic V.D.,Institute For Microwave Technique And Electronics Imtel Komunikacije Ad | Dukic M.L.,University of Belgrade
Electronics Letters | Year: 2010

An algorithm is described for estimation of multipath fading channels without a priori information on channel characteristics, for application in automatic modulation classification based on normalised sixth-order cumulants. Compared with existing approaches, the proposed algorithm can achieve much better classification accuracy in distinguishing complex-valued modulation techniques. Theoretical analysis is verified via extensive Monte-Carlo simulations. © 2010 The Institution of Engineering and Technology.

Stankovic K.D.,University of Belgrade
Nuclear Technology and Radiation Protection | Year: 2011

This paper investigates, through theory and experiment, the influence of the plain-parallel electrode surface dimensions change on the type A measurement uncertainty of a GM counter. The possibilities of applying these results to practical structures are examined by using the methods of mathematical statistics. Special attention is devoted to the influence of electrode surface enlargement on the statistical be havior of the pulse number random variable, expressed in the form of the en large ment law. In the the oretical part of the paper, the general surface enlargement law is derived. Comparison of experimental results with those predictedby the surface enlargement law proved its validity for expressing the type A measure mentun certainty of GM counters constructed with a plainparallel electrode configuration with a homogenous electric field.

Ren J.,Lawrence Berkeley National Laboratory | Ren J.,Shandong Normal University | Vukmirovic N.,University of Belgrade | Wang L.-W.,Lawrence Berkeley National Laboratory
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

We present a large-scale nonadiabatic molecular dynamics simulation to study carrier transport in an organic monolayer. This simulation calculates a 4802-atom system for 825 fs in about 3 h using 51 744 computer cores, while deploying a plane-wave pseudopotential density-functional theory Hamiltonian. A new approach is developed that makes such large-scale calculation possible. Our simulation on the pentathiophene butyric acid monolayer reveals the mechanism for the carrier transport in the system: the hole wave functions are localized by thermal fluctuation-induced disorder, while the hole transport is via charge transfer during state energy crossing. The simulation also shows that the system is never in a thermodynamic equilibrium in terms of adiabatic-state populations according to Boltzmann distribution. © 2013 American Physical Society.

In the present study, the pyrolysis process under dynamic conditions of swine manure solids collected from rearing farm was investigated. Tested type of biomass feedstock was analyzed from the point of view of technological exploitation in order to obtain the highest possible quality and yields of bio-oil and bio-char. Furthermore, char gasification process was also examined. It was found that pyrolysis process can be described by parallel independent two-portion process model (PI-TPPM), which includes two processing state of the system (marked by processes # 1 and # 2), where process # 1 can be attributed to decomposition processes of hemicelluloses and fats/proteins, while process # 2 corresponds to pyrolyses of cellulose and lignin. Also, it was found that liquid and gas yields increase with an increase in heating rate, while approximately 40% of heavy oil yield is achieved by proposed experimental setup, which have been attained the satisfactory results for a good support in industrial extraction procedures. It was found that results associated with the presence of high reactivity at highest heating rate can be attributed to the highly porous structures formed, as we approach to the fast pyrolysis conditions. © 2015 Elsevier B.V. All rights reserved.

Objectives: The relevance of placental growth factor was analyzed at the admission of patients with acute coronary syndrome (ACS) without ST elevation in prognosis of fatal outcome after 30 days. Methods: We collected blood samples from 102 ACS patients admitted to the coronary unit with acute chest pain manifesting within the last 12 hours. Results: In all 102 admitted patients, higher values of placental growth factor (PLGF; >13.2 ng/L, average value) indicated a higher risk of fatal outcome (hazard ratio [HR] 2.28, 95% confidence interval [CI] 1.21- 4.76, P = 0.0125). PLGF is an important independent prognostic marker (adjusted HR 2.35, 95% CI 1.98-4.61, P = 0.1338), and this was shown in a multiparameter model, which involved other statistically important markers of relative risk (age > 65, gender, and estimated glomerular filtration rate [eGFR]). Conclusion: PLGF levels measured at 12 hours of symptom onset and 30 days later may independently predict fatal outcome in patients with ACS without ST elevation. Copyright © 2010 by The Southern Medical Association.

Batalovic V.,University of Belgrade
International Journal of Mineral Processing | Year: 2011

Treatment of flotation slurries, waste waters containing a large amount of: solid particles, dissolved air or gas, chemicals etc. imposes centrifugal separation as one of the technically and economically acceptable solutions. There are numerous technical solutions and devices which use the centrifugal force for: separation, classification, dewatering, etc.; in mineral processing, waste water treatment, etc. The separator that we hereby present, removing some of the noted deficiencies on the existing solutions, introduces improvements in the sphere of self-suction, continual discharge and product transport. It is significant that this new solution can be used for the treatment of flotation tailings containing large amounts of finest particles. Displaying the innovative separator solution, the author analyses the existing theoretical separation basis and while noting certain weaknesses, forms a new approach to defining separation capacities. The theoretical and constructive innovations have been tested, using the separator prototype and displaying the acquired results. The aim of the research is to acquire accurately defined data based on which not only the designer, but the user as well, would be able to choose the most suitable solution for its problem. The secondary, but not less important aim, is to respond to the requests of a potential user: "Suva Ruda"- Raška Flotation. © 2011 Elsevier B.V. All rights reserved.

Urosevic D.,University of Belgrade
Astrophysics and Space Science | Year: 2014

The theoretical fundamentals of formation of the supernova remnant (SNR) continuum radio spectra are presented in this review. Mainly based on the Fermi 1 theory—also known as diffuse shock acceleration (DSA)—the different shapes (linear or curved in log-log scale) of SNR radio spectra are predicted for both young and evolved SNRs. On the other hand, some particular forms of spectra of older SNRs can be predicted by including the additional processes such as Fermi 2 acceleration mechanism or thermal bremsstrahlung radiation. Also, all of these theoretically predicted forms of radio spectra are compared with real spectra obtained from observations. Finally this review can represent some kind of “atlas” with initial patterns for the different kinds of SNR radio spectra—it should be helpful for radio astronomers in their interpretation of the observed radio spectra. © 2014, Springer Science+Business Media Dordrecht.

Lazic V.,ENEA | Jovicevic S.,University of Belgrade | Carpanese M.,ENEA
Applied Physics Letters | Year: 2012

Light transmission through a laser formed bubble (LFB) following ablation of a metallic target inside water was studied. During the early expansion and late collapsing phases, the refraction index n b of the hot high-pressure vapor bubble is higher than 1.23 and close to that of the surrounding liquid. The cavity growth lowers n b down to 1.00 and causes strong defocusing of the incident laser beam with consequent enlargement of the ablation crater diameter, here overcoming factor two. Inhomogeneous water vapor clustering inside the cool expanded bubble further perturbs the light transmission and induces irregular ablation by the successive laser pulse. © 2012 American Institute of Physics.

Pejcic A.,University of Nis | Kesic L.J.,University of Nis | Milasin J.,University of Belgrade
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2011

Periodontitis has been identified as a potential risk factor for systemic pathologies such as cardiovascular disease (CVD). The aims of this investigation were to assess the relationship between periodontitis and systemic inflammatory factor, as well as to discover whether there is a relation to the severity of periodontitis and to the periodontopathogens. Periodontal examinations and serum C-reactive protein (CRP) level measurements were performed in 50 patients with periodontitis. Periodontal health indicators included the gingival bleeding on probing index and periodontal disease status. The patients with moderate periodontitis had low attachment loss and pocket depth <4 mm. The patients with severe periodontitis had high attachment loss and pocket depth >5 mm. The control group comprised 25 volunteers with healthy gingiva, gingival sulcus <2 mm and no attachment loss. The presence of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in subgingival plaque samples was analysed by the polymerase chain reaction (PCR) method. The periodontal parameters and CRP levels were significantly higher in the patients with periodontitis. Patients who had severe periodontitis, with high levels of mean clinical attachment loss, and subjects with moderate periodontitis had higher mean CRP levels. The percentage of subjects with elevated levels of CRP >5 mg/l was greater in the higher clinical attachment loss group compared to the group with lower attachment loss. The presence of P. gingivalis and A. actinomycetemcomitans were also associated with elevated CRP levels and poor periodontal status. Periodontitis and the presence of P. gingivalis are associated with an enhanced inflammatory response expressed by higher CRP levels. The association of periodontitis with CRP levels appears to be a contributing factor for CVD and might be a possible intermediate pathway in this association. © 2010 Springer-Verlag.

Popovic D.B.,University of Belgrade | Popovic D.B.,Serbian Academy of Science and Arts
Journal of Electromyography and Kinesiology | Year: 2014

This review discusses the advancements that are needed to enhance the effects of electrical stimulation for restoring or assisting movement in humans with an injury/disease of the central nervous system. A complex model of the effects of electrical stimulation of peripheral systems is presented. The model indicates that both the motor and sensory systems are activated by electrical stimulation. We propose that a hierarchical hybrid controller may be suitable for functional electrical stimulation (FES) because this type of controller acts as a structural mimetic of its biological counterpart. Specific attention is given to the neural systems at the periphery with respect to the required electrodes and stimulators. Furthermore, we note that FES with surface electrodes is preferred for the therapy, although there is a definite advantage associated with implantable technology for life-long use. The last section of the review discusses the potential need to combine FES and robotic systems to provide assistance in some cases. © 2014 Elsevier Ltd.

Lazic L.,University of Belgrade | Pejanovic G.,South Environment and Weather Agency | Zivkovic M.,South Environment and Weather Agency
Renewable Energy | Year: 2010

The goal of this article is to apply the regional atmospheric numerical weather prediction Eta model and describe its performance in validation of the wind forecasts for wind power plants. Wind power generation depends on wind speed. Wind speed is converted into power through characteristic curve of a wind turbine. The forecasting of wind speed and wind power has the same principle. Two sets of Eta model forecasts are made: one with a coarse resolution of 22 km, and another with a nested grid of 3.5 km, centered on the Nasudden power plants, (18.22°E, 57.07°N; 3 m) at island Gotland, Sweden. The coarse resolution forecasts were used for the boundary conditions of the nested runs. Verification is made for the nested grid model, for summers of 1996-1999, with a total number of 19 536 pairs of forecast and observed winds. The Eta model is compared against the wind observed at the nearest surface station and against the wind turbine tower 10 m wind. As a separate effort, the Eta model wind is compared against the wind from tower observations at a number of levels (38, 54, 75 and 96 m). Four common measures of accuracy relative to observations - mean difference (bias), mean absolute difference, root mean square difference and correlation coefficient are evaluated. In addition, scatter plots of the observed and predicted pairs at 10 and 96 m are generated. Average overall results of the Eta model 10 m wind fits to tower observations are: mean difference (bias) of 0.48 m/s, mean absolute difference of 1.14 m/s, root mean square difference of 1.38 m/s, and the correlation coefficient of 0.79. Average values for the upper tower observation levels are the mean difference (bias) of 0.40 m/s; mean absolute difference of 1.46 m/s; root mean square difference of 1.84 m/s and the correlation coefficient of 0.80. © 2009 Elsevier Ltd. All rights reserved.

Milic D.,University of Belgrade | Prato M.,University of Trieste
European Journal of Organic Chemistry | Year: 2010

Two classes of unsymmetrical, orthogonally protected bisfulleropyrrolidine amino acids have been prepared as models for fullerene-based peptidomimetics with the carbon sphere inserted into the peptide backbone. Two successive [3+2] cycloadditions of azomethine ylides (thermally generated from formaldehyde and the corresponding orthogonally protected glycino-amines and -acids) to C 60 afforded NHFmoc/ CO2tBu and NHBoc/CO2Me fulleropyrrolidine couples, offering the possibility of selective deprotection under both acidic and basic conditions. In both classes of unsymmetrical bis-adducts, the distribution of all the trans (t1-t4) and equatorial (e′ and e″) isomers was quite similar except for the t3 NHBoc/CO2Me compound, which rapidly decomposed during chromatography. All compounds were characterized by UV/Vis, 1H and 13C NMR spectroscopy, and mass spectrometry. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Chen H.-X.,Beihang University | Dmitrasinovic V.,University of Belgrade
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

Fierz identities follow from permutations of quark indices and thus determine which chiral multiplets of baryon fields are Pauli allowed and which are not. In a previous paper we investigate the Fierz identities of baryon fields with two light flavors and find that all bilocal fields that can be constructed from three quarks are Pauli allowed. That does not mean that all possible chiral multiplets exist; however, some chiral multiplets do not appear among structures with a given spin in the local limit, say J=1/2. One such chiral multiplet is the [(6,3)âŠ(3,6)], which is necessary for a successful chiral mixing phenomenology. In the present paper we extend those methods to three light flavors, i.e., to SUF(3) symmetry and explicitly construct all three necessary chiral SUL(3)×SU R(3) multiplets, viz. [(6,3)âŠ(3,6)], [(3,3̄)âŠ(3̄,3)], and [(3̄,3)âŠ(3, 3̄)] that are necessary for a phenomenologically successful chiral mixing. We complete this analysis by considering some bilocal baryon fields that are sufficient for the construction of the "missing" spin-1/2 baryon interpolating fields. Bilocal baryon fields have definite total angular momentum only in the local limit. The physical significance of these results lies in the fact that they show that there is no need for higher Fock space components, such as the q4q̄, in the baryon chiral mixing framework, for the purpose of fitting the observed axial couplings and magnetic moments: all of the sufficient "mirror components" exist as bilocal fields. © 2013 American Physical Society.

In this work, Apis mellifera carnica and A. m. macedonica honey bees from Serbia, Bosnia and Herzegovina and Republic of Macedonia were analysed using molecular techniques in order to improve our knowledge about biogeography of A. mellifera on the Balkan peninsula. This is the first time that the indigenous honey bees from Bosnia and Herzegovina and Republic of Macedonia have been analyzed using a molecular approach. Sampling was carried out from 560 stationary apiaries where bees were kept in traditional hives (woven skeps). The COI-COII regions of 1680 samples were PCR-amplified and sequenced. To reveal the haplotype of studied bees, the obtained sequences were aligned with published sequence data of haplotypes that belong to A. mellifera C phylogenetic lineage. The C2D mtDNA haplotype was found in all honey bees sampled from Serbia, Bosnia and Herzegovina and Republic of Macedonia. These results show that A. m. carnica and A. m. macedonica share the same C2D mtDNA haplotype. COI gene segments of 1680 samples were PCR-amplified and digested with restriction enzymes NcoI and StyI in order to discriminate A. m. macedonica from A. m. carnica. Amplified fragment patterns produced by both restriction enzymes matched with diagnostic pattern characteristic for A. m. macedonica in case of samples from east, south and south-west parts of Serbia, and Republic of Macedonia, fragments of samples from northern part of Serbia and Bosnia and Herzegovina did not include NcoI and StyI restriction sites. These results indicate that honey bees from east, south and south-west parts of Serbia, and Republic of Macedonia belong to the A. m. macedonica, and honey bees from northern part of Serbia and Bosnia and Herzegovina belong to another subspecies, probably to the A. m. carnica. Therefore A. m. macedonica has much wider area of distribution than it was previously considered.

Blachnio A.,Catholic University of Lublin | Przepiorka A.,Catholic University of Lublin | Pantic I.,University of Belgrade
Computers in Human Behavior | Year: 2016

In recent years, many research efforts have been focused on investigation of potential connection between social networking and mental health issues. Particularly important and controversial remains the association between Facebook use, self-esteem and life satisfaction. In our cross-sectional study, on a sample of 381 Facebook users, we tested the existence and strength of this relationship using Bergen Facebook Addiction Scale (BFAS), Facebook Intensity Scale (FBI), Rosenberg's Self-Esteem Scale (SES), and Satisfaction With Life Scale (SWLS). With k-means cluster analysis, we divided the sample into 3 groups: ordinary, intensive, and addicted Facebook users. The results of our study show that ordinary Facebook users differ statistically in self-esteem and life satisfaction from both addicted and intensive users. Facebook addiction was in relation with lower self-esteem. Facebook addiction was also negatively related to life satisfaction. These results are in accordance with the previously published findings of other authors in the fields of social networking psychology and psychiatry. © 2015 Elsevier Ltd. All rights reserved.

Geschke R.H.,Stellenbosch University | Jokanovic B.,University of Belgrade | Meyer P.,Stellenbosch University
IEEE Transactions on Microwave Theory and Techniques | Year: 2011

A configuration of composite resonators consisting of three split-ring resonators is proposed to obtain a triple-band response with two transmission zeros between the passbands. Two new topologies are presented to design triple-band filters with controllable responses. A systematic filter design approach is presented based on a filter coupling model. The model is established to enable triple-band filter design with controlled passbands. Two methods are proposed and compared for the extraction of filter parameters. Coupling between nonadjacent elements is considered in the model and shown to have a significant effect. By changing the orientation of the coupled composite resonators, it is possible to introduce additional transmission zeros. Two sixth-order filter examples illustrate the use of the coupling model with the filter design approach to design filters with specified responses. The limitations of this filter topology are discussed. © 2006 IEEE.

Markovic D.,University of Belgrade
European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry | Year: 2010

Children with amelogenesis imperfecta (AI) experience many oral difficulties including sensitivity and aesthetics. The methods of treating AI children are limited and therefore a program of care was evaluated in order to assess the clinical efficacy of providing preventive and restorative treatments. A non-randomised convenience sample of 12 patients with AI was evaluated. A comprehensive patient history was recorded, followed by a clinical and radiographic assessment of oral health. In 8/12 patients a hypoplastic form of AI was diagnosed, in 2/12 cases hypomaturation and in 2/12 cases hypocalcified form were noted. Chief complaints were mainly related to unsatisfactory aesthetics and dental sensitivity. In 8 patients there was active dental caries. Most of the patients had gingivitis and showed fair oral hygiene. The presence of non-enamel dental anomalies was recorded in 9 patients. All patients received meticulous preventive care. Initial treatment depended on AI type and oral health of the patient. During the transition period, both conventional and resin modified glassionomer cements, as well as composite resin materials, were used to restore posterior teeth. Direct composite resin restorations were used to improve the appearance of anterior teeth. In 4 patients a long-lasting interdisciplinary approach including orthodontics, metal-ceramic crowns and fixed partial dentures, and direct composite restorations was required. FOLLOW-UP: Follow-up periods varied between 2-11 years. All children have been regularly recalled at 3 monthly intervals. Caries prevalence has remained low during the follow-up postoperative period and patients have reported satisfaction with the treatment they have received. AI is associated with multiple non-enamel anomalies and requires a complex treatment. Treatment planning is related to the age of the patient, the type and severity of the disorder, and the oral health of the patient. Early diagnosis, preventive care and timely treatment are of foremost importance to improve oral health in children with AI.

Zhong W.-P.,Shunde Polytechnic | Belic M.R.,Texas A&M University at Qatar | Belic M.R.,University of Belgrade | Huang T.,Texas A&M University at Qatar
Nonlinear Dynamics | Year: 2012

Two-dimensional parity-time (PT) symmetric potentials are introduced, which allow the existence of spatial solitons in the model of the strongly nonlocal nonlinear Schrödinger equation. Two-dimensional accessible solitons are found in the form of solutions separating the radial amplitude, given in terms of Laguerre polynomials, a phase function involving quadratic, linear, and constant phase shifts, and a specific azimuthal modulation function. Shape-preserving solitons are constructed from Laguerre-Gaussian functions containing the self-similar variable and an exponential form of the azimuthal modulation, containing sine and cosine functions, when a suitable PT-symmetric potential is chosen. Interesting soliton profiles and the corresponding PT-symmetric potentials are displayed for different values of the parameters. © Springer Science+Business Media B.V. 2012.

Majkic-Singh N.,University of Belgrade
Journal of Medical Biochemistry | Year: 2011

The term biomarker in medicine most often stands for a protein measured in the circulation (blood) whose concentration indicates a normal or a pathological response of the organism, as well as a pharmacological response to the applied therapy. From a wider perspective, a biomarker is any indicator that is used as an index of the intensity of a disease or other physiological state in the organism. This means that biomarkers have a very important role in medical research and practice providing insight into the mechanism and course of a disease. Since a large number of biomarkers exist today that are used for different purposes, they have been classified into: 1) antecedent biomarkers, indicating risk of disease occurrence, 2) screening biomarkers, used to determine a subclinical form of disease, 3) diagnostic biomarkers, revealing an existing disease, 4) staging biomarkers, that define the stage and severity of a disease, and 5) prognostic biomarkers, that confirm the course of disease, including treatment response. Regardless of their role, their clinical significance depends on their sensitivity, specificity, predictive value, and also precision, reliability, reproducibility, and the possibility of easy and wide application. For a biomarker to become successful, it must undergo the process of validation, depending on the level of use. It is very important for every suggested biomarker, according to its purpose or its nature, to possess certain characteristics and to meet the strict requirements related to sensitivity, accuracy and precision, in order for the proper outcome to be produced in the estimation of the state for which it is intended. Finally, the development of guidelines for biomarker application is very important, based on well defined and properly conducted assessments of biomarker determination, providing the means by which research is translated into practice and allowing evidence based on facts to promote the clinical application of new biomarkers.

Loncar N.,University of Belgrade | Fraaije M.W.,University of Groningen
Applied Microbiology and Biotechnology | Year: 2015

Catalases represent a class of enzymes which has found its place among industrially relevant biocatalysts due to their exceptional catalytic rate and high stability. Textile bleaching prior to the dyeing process is the main application and has been performed on a large scale for the past few decades. Their limited substrate scope has not prevented the development of various other catalase-based applications. Newly developed approaches continue to exploit their excellent catalytic potential to degrade hydrogen peroxide while (per)oxidase activity of catalases is opening a new range of possibilities as well. This review provides an overview of applications that involve heme-containing catalases that have been demonstrated in recent years. © 2015, Springer-Verlag Berlin Heidelberg.

Denic L.M.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2012

Health workers and medical students are at occupational risk of blood-borne diseases during the accidents, that is, via percutaneous injury or entry of blood or body fluids through the mucosa or injured skin. to review and analyze the knowledge, attitudes and perception of risks of bloodborne diseases of the clinical course students and health workers as well as the frequency of accidents. Cross-sectional study was carried out among the students of the Faculty of Medicine in Belgrade, and health workers of the Clinical Center of Serbia. The subjects responded anonymously to questionnaire specially designed for the study. Both students and health workers were aware, in a high percentage, of the fact that the risk of hepatitis B spread was about 30%. Significantly more students gave affirmative reply that blood as biological material was a potential hazard of HIV infection spread (p = 0.001), and significantly more students knew that HIV would not be spread by sweat (p = 0.001). Hepatitis B vacci-nation was administered only to 24.1% of students and 71.4% of health workers. About 10% of students and 65.5% of health workers experienced some accident. There was no significant difference of accidents bet-ween nurses/technicians and physicians (p > 0.05), as well as of accidents and a total length of service (p > 0.05). The majority of accidents occurred during the use of needle/sharp object (in 27.3% of students and 33.1% of health workers). About 40% of students and slightly over a half of the workers reported the accidents to appropriate authorities. Additional education in this field is considered necessary by 73% of students. During the studies and via continuous medical education it is necessary to upgrade the level of knowledge on prevention of accidents, what would, at least partially, influence their reduction.

Brajevic I.,University of Belgrade | Tuba M.,Megatrend University
Studies in Computational Intelligence | Year: 2014

Multilevel image thresholding is a technique widely used in image processing, most often for segmentation. Exhaustive search is computationally prohibitively expensive since the number of possible thresholds to be examined grows exponentially with the number of desirable thresholds. Swarm intelligence metaheuristics have been used successfully for such hard optimization problems. In this chapter we investigate performance of two relatively new swarm intelligence algorithms, cuckoo search and firefly algorithm, applied to multilevel image thresholding. Particle swarm optimization and differential evolution algorithms have also been implemented for comparison. Two different objective functions, Kapur's maximum entropy thresholding function and multi Otsu between-class variance, were used on standard benchmark images with known optima from exhaustive search (up to five threshold points). Results show that both, cuckoo search and firefly algorithm, exhibit superior performance and robustness. © 2014 Springer International Publishing Switzerland.

Vulevic B.,Vinca Institute of Nuclear Sciences | Osmokrovic P.,University of Belgrade
Radiation Protection Dosimetry | Year: 2010

With regard to Non-ionising radiation protection, the relationship between human exposure to electromagnetic fields and health is controversial. Electromagnetic fields have become omnipresent in the daily environment. This paper assesses the problem of how to compare a measurement result with a limit fixed by the standard for human exposure to electric, magnetic and electromagnetic fields (0 Hz-300 GHz). The purpose of the paper is an appropriate representation of the basic information about evaluation of measurement uncertainty. © The Author 2010. Published by Oxford University Press. All rights reserved.

Simic D.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2011

In patients with respiratory pathology changes in respiratory physiology may lead to clinical problems during the conduct of anesthesia and the perioperative period. An understanding of the disease processes that can affect the lungs and pleura allows the anesthesiologist to account for the potential complications of these conditions and manage the anesthetic accordingly. This article describes the initial evaluation of a patient with respiratory problems. A thorough medical history, physical examination and some functional tests are the keys in decision-making in preparation for anesthesia and surgery. The burden of respiratory disease is reviewed, and some important areas of current interest are highlighted.

Vanevic M.,Technical University of Delft | Vanevic M.,University of Belgrade | Nazarov Y.V.,Technical University of Delft
Physical Review Letters | Year: 2012

Quantum phase slips are traditionally considered in diffusive superconducting wires which are assumed homogeneous. We present a definite estimate for the amplitude of phase slips that occur at a weak inhomogeneity in the wire where local resistivity is slightly increased. We model such a weak link as a general coherent conductor and show that the amplitude is dominated by the topological part of the action. We argue that such weak links occur naturally in apparently homogeneous wires and adjust the estimate to that case. The fabrication of an artificial weak link would localize phase slips and facilitate a better control of the phase-slip amplitude. © 2012 American Physical Society.

Belojevic G.,University of Belgrade
Noise & health | Year: 2011

Research on the cardiovascular effects of noise in Serbia started in the year 2002, including experimental studies on humans and epidemiological studies on the adult and children population of Belgrade and Pancevo. Experimental exposure to noise [L eq = 89 dB (A)] had a hypodynamic effect, significantly lowering the cardiac index, cardiac work, and pump performance (P < 0.01). The vasoconstrictive effect of noise was shown through the significant elevation of after-load (P < 0.01). In a cross-sectional population study that was carried out on 2874 residents [1243 males and 1631 females] in Pancevo City, a significant odds ratio (adjusted for age, body mass index (BMI), and smoking habits) was found for self-reported hypertension (OR = 1.8, 95% CI = 1.0 - 2.4, P < 0.01) in men with a high level of noise annoyance compared to those with a low level of noise annoyance. In another study on 2503 residents (995 men and 1508 women) residents of Belgrade, the proportions of men with hypertension in the noisy [(L night , 8h > 45 dB (A)] and quiet areas [(L night , 8h ≤ 45 dB (A)] were 23.6% and 17.5%, respectively. The adjusted odds ratio (OR) for hypertension of the exposed group was 1.58 (95% CI = 1.03 - 2.42, P = 0.038), where men living in quiet streets were taken as a reference category. Associations between road traffic noise and blood pressure were also investigated in 328 preschool children in Belgrade. The systolic blood pressure was significantly higher among children from noisy residences and kindergartens, compared to children from both quiet environments (97.30 ± 8.15 and 92.33 ± 8.64 mmHg, respectively, P < 0.01). As a continuation of the study on preschool children, investigations were also carried out on 856 school children, aged between seven and eleven years, in Belgrade. It was found that systolic pressure was significantly higher among children from noisy schools and quiet residences, compared to children from both quiet environments (102.1 ± 9,3 and 100.4 ± 10.4 mmHg, respectively, P < 0.01).

Liu G.,Lawrence Berkeley National Laboratory | Xun S.,Lawrence Berkeley National Laboratory | Vukmirovic N.,Lawrence Berkeley National Laboratory | Vukmirovic N.,University of Belgrade | And 6 more authors.
Advanced Materials | Year: 2011

A conductive polymer is developed for solving the long-standing volume change issue in lithium battery electrodes. A combination of synthesis, spectroscopy and simulation techniques tailors the electronic structure of the polymer to enable in situ lithium doping. Composite anodes based on this polymer and commercial Si particles exhibit 2100 mAh g -1 in Si after 650 cycles without any conductive additive. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

End-of-life vehicles (ELVs) are vehicles that have reached the end of their useful lives and are no longer registered or licensed for use. The ELV recycling problem has become very serious in the last decade and more and more efforts are made in order to reduce the impact of ELVs on the environment. This paper proposes the fuzzy risk explicit interval linear programming model for ELV recycling planning in the EU. It has advantages in reflecting uncertainties presented in terms of intervals in the ELV recycling systems and fuzziness in decision makers' preferences. The formulated model has been applied to a numerical study in which different decision maker types and several ELV types under two EU ELV Directive legislative cases were examined. This study is conducted in order to examine the influences of the decision maker type, the α-cut level, the EU ELV Directive and the ELV type on decisions about vehicle hulks procuring, storing unprocessed hulks, sorting generated material fractions, allocating sorted waste flows and allocating sorted metals. Decision maker type can influence quantity of vehicle hulks kept in storages. The EU ELV Directive and decision maker type have no influence on which vehicle hulk type is kept in the storage. Vehicle hulk type, the EU ELV Directive and decision maker type do not influence the creation of metal allocation plans, since each isolated metal has its regular destination. The valid EU ELV Directive eco-efficiency quotas can be reached even when advanced thermal treatment plants are excluded from the ELV recycling process. The introduction of the stringent eco-efficiency quotas will significantly reduce the quantities of land-filled waste fractions regardless of the type of decision makers who will manage vehicle recycling system. In order to reach these stringent quotas, significant quantities of sorted waste need to be processed in advanced thermal treatment plants. Proposed model can serve as the support for the European vehicle recycling managers in creating more successful ELV recycling plans. © 2014 Elsevier Ltd.

Vukmirovic N.,University of Belgrade | Bruder C.,University of Basel | Stojanovic V.M.,University of Basel
Physical Review Letters | Year: 2012

We consider electron-phonon coupling in crystalline organic semiconductors, using naphthalene for our case study. Employing a first-principles approach, we compute the changes in the selfconsistent Kohn-Sham potential corresponding to different phonon modes and go on to obtain the carrier-phonon coupling matrix elements (vertex functions). We then evaluate perturbatively the quasiparticle spectral residues for electrons at the bottom of the lowest unoccupied (LUMO), and holes at the top of the highest occupied (HOMO), band, obtaining Z e≈0.74 and Z h≈0.78, respectively. Along with the widely accepted notion that the carrier-phonon coupling strengths in polyacenes decrease with increasing molecular size, our results provide strong microscopic evidence for the previously conjectured nonpolaronic nature of bandlike carriers in these systems. © 2012 American Physical Society.

Palibrk I.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2011

Ageing of populataion world wide has significant contribution as one of the major risk factor for neurodegenerative disorders. The patients with neurodegenerative as well as other neuological diseases presented the population with possible great need either of small or big surgical intervention. There are several important issues in patients with neurological diseases: the nature, disease duration, therapy, the patient's ability to live without assistance. Neurological disease may become worst by general and regional anesthesia. Stopping therapy may lead to worsening of neurological diseases. One of the main common threat is the risk of significant cardiorespiratory complications, which is important in assessing operational risk, in preoperative preparation and in terms of postoperative recovery and outcomes of surgical treatment. This has resulted in greater preoperative care by detailed patient history evaluation and examination, patient information and informed consent. Besides the effect of the anaesthetic technique upon the course of the disease, there is also the interaction of drugs administered during anaesthesia and patient medication. Several undiagnosed diseases may be disclosed following a surgical/anaesthetic intervention.

Mandic L.J.,Military Medical Academy | Dragovic S.,University of Belgrade
Radiation Protection Dosimetry | Year: 2010

The activity concentrations of 226Ra, 232Th and 40K in 178 samples from 52 locations of the territory of Belgrade, the capital of Serbia, were determined by gamma-ray spectrometry. Based on the results obtained, the values of absorbed gamma dose rate at 1 m above the ground, radium equivalent activity, external hazard index, annual effective dose, annual gonadal dose and excess lifetime cancer risk were calculated. The results of the present study were compared with values reported worldwide and also with internationally recommended values. The total absorbed dose rate varied between 24.7 and 89.6 nGy h-1 with a mean of 60.5 nGy h-1, which is close to the world average value. Since all estimated radiological impact assessment factors were lower than the recommended values there seems to be no radiological health hazard for the population living in the investigated area. © The Author 2010. Published by Oxford University Press.

Gudimenko E.,Dublin City University | Milosavljevic V.,Dublin City University | Milosavljevic V.,University of Belgrade | Daniels S.,Dublin City University
Optics Express | Year: 2012

Accurate optical emission spectroscopy (OES) measurements are necessary for plasma semiconductor processing and for optical emission analysis. In this paper we investigate the effects of self-absorption on the most important neutral Argon spectra lines. One of these Argon spectral lines (750 nm) is frequently used for actinometry. The experiment is performed in a reactive ion etch (RIE) capacitively coupled plasma (CCP) system. A comprehensive design of experiments has been created to establish all plasma conditions, power, pressure and gas flow rate which affect the Argon emission intensity by self-absorption. The results are then compared to theoretical calculated line ratios. © 2012 Optical Society of America.

Matauek M.R.,University of Belgrade
Journal of Process Control | Year: 2010

The proposed method for designing multivariable controller is based on ideal decoupler D(s) and PID controller optimization under constraints on the robustness and sensitivity to measurement noise. The high closed-loop system performance and robustness are obtained using the same controller in all loops. The method is effective despite the values and positions of the right half plane zeros and dead-times in the process transfer function matrix Gp(s). The validity of the proposed multivariable control system design and tuning method is confirmed using a test batch consisting of Two-Input Two-Output (TITO) stable, integrating and unstable processes, and one Three-Input Three-Output (TITO) stable process. © 2010 Elsevier Ltd. All rights reserved.

Jankovic B.,University of Belgrade
Journal of Thermal Analysis and Calorimetry | Year: 2016

The on-line dynamic pyrolysis kinetics of swine manure solid samples was investigated in this paper. It has been found that the model which includes combined Friedman's isoconversional and multi-distributed reactivity approaches can best describe the pyrolysis process. Pyrolysis kinetics of swine manure samples proceeds through two major pyrolysis zones, where in first zone exists the kinetically complex reactions related to decompositions of hemicelluloses and fat/proteins, as well as decomposition reactions related to degradation of cellulose and lignin structures. Second zone includes the reactions attached to follow-up devolatilization and carbonization processes. It was found that identified high reaction orders represent the measure of complexity and multiplicity of the mechanism. It has been found that the change in reaction order (n) values is the result of reactions that are taking place due to the instability of products, or the secondary reactions, change in apparent activation energy, and effect of varying of the pre-exponential factor values. © 2015 Akadémiai Kiadó, Budapest, Hungary.

In order to study the variability and heritability of directly measured traits (growth and body development traits) in performance test of Simmental bulls the data on 371 bulls born and tested over the period of 13 years were used in the analysis. The data were analysed in order to estimate year and month of calving, herd of origin and group in test effect as well as error components. The components of variance were obtained using restricted maximum likelihood (REML) methodology applied to sire model. The year and month of birth had different effect on the variability of the growth traits, while the herd of origin and the test group manifested a consistent, highly significant effect on those growth traits which they could have an effect on. On the other hand, all the body development traits were under a constant and highly significant effect manifested by the year of calving, while the month of calving manifested its effect, during test, at different levels of statistical significance. A decreased effect of herd of origin on almost all body dimensions from the start until the end of performance test was universally observed. Heritability estimates for pre-test ADG, in-test and lifetime ADG were 0.27, 0.39 and 0.29, respectively. Heritability estimates for body weights were 0.23, 0.25, and 0.30 for birth weight, test-on weight, and test-off weight, respectively. Heritability estimates for test-off height at withers, circumference of chest, depth of chest and body length were 0.43, 0.30, 0.33 and 0.29.

Nikolic B.,University of Belgrade
Journal of Physics Condensed Matter | Year: 2010

In this work Raman excitation profiles of metallic carbon nanotubes have been calculated and thoroughly analyzed. Suppression and vanishing of the high-energy resonance is completely confirmed by our calculations. The presented results clearly show that the suppression, and finally the absence, of the resonance is caused by electron-phonon interaction and interference effects. Electron-phonon coupling for low-energy resonance is significantly larger than for high-energy resonance. Furthermore, the transition energies of those two transitions are close enough to make interference effects important. The type of interference is determined by the sign of the electron-phonon interaction matrix elements. Constructive interference makes the low-energy resonance more intensive and destructive interference destroys the high-energy resonance for most of the metallic tubes. © 2010 IOP Publishing Ltd.

Cica Z.,University of Belgrade
Electronics Letters | Year: 2016

It has been shown that input queued (IQ) switches have throughput limitations when loaded with multicast traffi c. However, if circulation of packets is allowed, the IQ switches can be non-blocking for any admissible multicast traffi c scenario using only a speedup of two. The non-blocking frame based algorithm for schedulin g the multicast traffi c is proposed. © 2016 The Institution of Engineering and Technology.

Blachnio A.,Catholic University of Lublin | Przepiorka A.,Catholic University of Lublin | Pantic I.,University of Belgrade
European Psychiatry | Year: 2015

Facebook has become a very popular social networking platform today, particularly among adolescents and young adults, profoundly changing the way they communicate and interact. However, some reports have indicated that excessive Facebook use might have detrimental effects on mental health and be associated with certain psychological problems. Because previous findings on the relationship between Facebook addiction and depression were not unambiguous, further investigation was required. The main objective of our study was to examine the potential associations between Internet use, depression, and Facebook intrusion. A total of 672 Facebook users took part in the cross-sectional study. The Facebook Intrusion Questionnaire and the Center for Epidemiologic Studies Depression Scale were used. For collecting the data, the snowball sampling procedure was used. We showed that depression can be a predictor of Facebook intrusion. Our results provides additional evidence that daily Internet use time in minutes, gender, and age are also predictors of Facebook intrusion: that Facebook intrusion can be predicted by being male, young age, and an extensive number of minutes spent online. On the basis of this study, it is possible to conclude that there are certain demographic - variables, such as age, gender, or time spent online - that may help in outlining the profile of a user who may be in danger of becoming addicted to Facebook. This piece of knowledge may serve for prevention purposes. © 2015 Elsevier Masson SAS.

Stankovic S.,University of Belgrade | Jovic M.,Vinca Institute of Nuclear Sciences
Environmental Chemistry Letters | Year: 2012

In recent years, mussels have already become commercially important seafood species worldwide. Mussels accumulate a wide range of metals in their soft tissue. Thus, the determination of accumulated concentrations of heavy metals, such as Pb, Cd, Hg, and As, in mussels is essential because of their usage as seafood and the potential adverse effects of their consumption on human health. In this review, these issues are presented and discussed using the Mediterranean mussel Mytilus galloprovincialis as an example. M. galloprovincialis is very efficient at converting low value victuals into high quality animal protein. The production of M. galloprovincialis in Mediterranean countries has been increasing rapidly, but Spain is still the largest producer of mussels. Only China has a larger production of these mussels than Spain. M. galloprovincialis is a filter feeding animal and accumulates a wide range of metals from their environment. The metal concentrations in the soft tissue of M. galloprovincialis are indicators of marine ecosystems contamination. In the same time, the bioaccumulation of heavy metals remains an issue concerning the consumption of mussels. Thereby, the Cd, Pb, Hg, and As concentration measurement in mussel soft tissue as a seafood have become significant. A review of literature data revealed large variations in the Cd, Pb, Hg, and As concentrations in M. galloprovincialis from their endemic areas, e. g., Mediterranean, Adriatic, and Black Sea, and the concentrations of these toxic metals were generally in the following order: As > Pb > Cd > Hg. The guidelines on heavy metals for seafood safety set by different countries and associations are reviewed. Comparison of the published data with European legislation showed that the levels of the heavy metals generally did not exceed the existing limits in all the mussels analyzed, excluding mussels from hot spots, such as lagoons and harbors, in the Mediterranean, Adriatic, and Black Sea. © 2011 Springer-Verlag.

Text line segmentation represents the key element in the optical character recognition process. Hence, testing of text line segmentation algorithms has substantial relevance. All previously proposed testing methods deal mainly with text database as a template. They are used for testing as well as for the evaluation of the text segmentation algorithm. In this manuscript, methodology for the evaluation of the algorithm for text segmentation based on extended binary classification is proposed. It is established on the various multiline text samples linked with text segmentation. Their results are distributed according to binary classification. Final result is obtained by comparative analysis of cross linked data. At the end, its suitability for different types of scripts represents its main advantage.

Devedzic V.,University of Belgrade
International Journal of Artificial Intelligence in Education | Year: 2016

If you ask me "Will Semantic Web ever happen, in general, and specifically in education?", the best answer I can give you is "I don't know, but I know that today we are still far away from the hopes that I had when I wrote my paper Education and The Semantic Web (Devedzic 2004) more than 10 years ago. Much of the things from that paper are today obsolete, but some remain. With the experience gained and lessons learned over time, as well as with many other developments in the general field of Web-based education, it is possible to sketch a much more realistic picture about Semantic Web and its implications for education than it was possible back then. This article attempts to capture that picture by discussing a diagram. © 2015 International Artificial Intelligence in Education Society.

urisic-Bojanovic M.,University of Belgrade
Journal for East European Management Studies | Year: 2016

In the process of organisational change, there are two broad categories of employees’ reactions: those who are open to change and those who have a difficult time accepting change in general, including organisational change. These differences can be linked to differences in cognitive style. Our hypotheses were tested and confirmed in two companies in different industrial sectors in Serbia (N=265). The results showed that cognitive style was a strong single predictor of general attitudes towards organizational change. We have proposed a procedure for obtaining the index of dispositional readiness for change, which is of critical importance for planning different strategies of change management. © Rainer Hampp Verlag.

Pajic-Lijakovic I.,University of Belgrade
Critical Reviews in Biotechnology | Year: 2015

Various modeling approaches have been applied to describe the rearrangement of immobilized cell clusters within the extracellular matrix. The cell rearrangement has been related with the micro-environmental restrictions to cell growth. Herein, an attempt is made to discuss and connect various modeling approaches on various time scales which have been proposed in the literature in order to shed further light to this complex phenomenon which induces microenvironmental restrictions to cell growth. The rearrangement is driven by internal stress generated within the cluster. The internal stress represents a consequence of the matrix rheological response to cell expansion. The rearrangement includes the interplay between the processes of: (1) single and collective cell migrations, (2) cell deformation and orientation, (3) decrease of cell-to-cell separation distances and (4) cell growth. It has been considered on two time scales: a short time scale (i.e. the rearrangement time) and a long time scale (i.e. the growing time). The results indicate that short and long times cell rearrangement induces energy dissipation. The dissipation provokes biological responses of cells which cause the resistance effects to cell growth. Deeper insight in the anomalous nature of the energy dissipation would be useful for understanding the biological mechanisms which causes the resistance effects to cell growth. © 2015 Informa Healthcare USA, Inc.

Jankovic S.,University of Belgrade
The European journal of esthetic dentistry : official journal of the European Academy of Esthetic Dentistry | Year: 2010

The main objective of this study was to evaluate the clinical effectiveness of platelet-rich fibrin membrane used in combination with a coronally advanced flap (CAF) and to compare it with the use of an enamel matrix derivative (EMD) in combination with a coronally advanced flap in gingival recession treatment. 20 split-mouth cases of maxillary anterior teeth or bicuspids presenting with Miller Class I or II gingival recession were treated with a CAF combined with a platelet-rich fibrin membrane (PRF group) or with EMD (EMD group) placed under a CAF. The following parameters were measured at baseline and at 12 months post treatment: gingival recession (GR), apicocoronal width of the keratinized tissue (WKT), and probing depth (PD). Complete rot coverage in the PRF group was 65% (13 out of 20 recessions) and 60% in the EMD group (12 out of 20 recessions). GR was 4.10 ± 1.05 mm in the PRF group and 3.90 ± 1.00 mm in the EMD group at baseline, and 1.05 ± 0.45 mm in the PRF group and 1.15 ± 0.65 mm in the EMD group at 12 months. The difference observed between the tow groups at 12 months was statistically significant. Average root coverage was 70.5% in the EMD group and 72.1% in the PRF group. WKT was 1.30 ± 0.56 mm in the EMD group and 1.45 ± 0.86 mm in the PRF group at baseline, and 1.90 ± 0.81 mm in the EMD group and 1.62 ± 0.28 mm in the PRF group at 12 months. The difference observed between the two groups at 12 months was not statistically significant. Twelve-month changes in PD were not significantly different between the two groups. The pain intensity was statistically different between the two groups. The pain intensity was statistically different between groups for the first 5 days, favoring the PRF group. The present study did not succeed in demonstrating any clinical advantage of the use of PRF compared to EMD in the coverage of gingival recession with the CAF procedure. The EMD group showed a higher success rate in increasing WKT than did the PRF group.

Aleksendric D.,University of Belgrade
Wear | Year: 2010

Wear of brake friction materials depends on many factors such as temperature, applied load, sliding velocity, properties of mating materials, and durability of the transfer layer. Prediction of friction materials wear versus their formulation and manufacturing conditions in synergy with brakes operating conditions can be considered as a crucial issue for further friction materials development. In this paper, the artificial neural network abilities have been used for predicting wear of the friction materials versus influence of all relevant factors. The neural model of friction materials wear has been developed taking into account: (i) complete formulation of the friction material (18 ingredients), (ii) the most important manufacturing conditions of the friction material (5 parameters), (iii) applied load and sliding velocity of the friction material both represented by work done by brake application, and (iv) brake interface temperature. © 2009 Elsevier B.V. All rights reserved.

The inhibition behaviour of the TRITON-X-405 mixed with KBr or C 4H 12NI in 2.0M H 2SO 4 on the ferritic SS was studied using potentiodynamic and EIS measurements. The electrochemical data showed that mixtures used in this study adsorbed on the SS's surface, in agreement with the Flory-Huggins adsorption isotherm. Polarization and EIS measurements indicated that KBr or C 4H 12NI had a significant synergistic effect with TRITON-X-405 in 2.0M H 2SO 4. This effect was more pronounced when adding C 4H 12NI, and at concentrations above the CMC of the used mixtures, which had been determined via corrosion-kinetic parameters. The inhibitive mechanism is proposed. © 2012 Elsevier Ltd.

Dimitrijevic S.,Mott MacDonald Ltd. | Rajakovic N.,University of Belgrade
IEEE Transactions on Smart Grid | Year: 2015

Minimization of the de-energized consumers load and reduction of the service restoration costs are considered in the proposed heuristic graph-based approach for finding the solution of the service restoration in distributed networks. The approach is based on the logic of the modified Prim's algorithm that finds the minimum spanning trees (i.e., a forest). Operation costs including an actual status ("open" or "close") of the switching equipment in a de-energized area is represented by the switching cost coefficients. The cost coefficients are assigned to all branches in a de-energized area. The switching action is performed by switching equipment with minimal switching costs coefficient in each iteration of the algorithm. The results confirm that the service restoration costs are decreased by the consideration of the actual status of the switching equipment. © 2010-2012 IEEE.

Potpara T.S.,University of Belgrade | Lip G.Y.H.,University of Birmingham
International Journal of Clinical Practice | Year: 2014

Atrial fibrillation (AF) sometimes develops in younger individuals without any evident cardiac or other disease. To refer to these patients who were considered to have a very favourable prognosis compared with other AF patients, the term 'lone' AF was introduced in 1953. However, there are numerous uncertainties associated with 'lone' AF, including inconsistent entity definitions, considerable variations in the reported prevalence and outcomes, etc. Indeed, increasing evidence suggests a number of often subtle cardiac alterations associated with apparently 'lone' AF, which may have relevant prognostic implications. Hence, 'lone' AF patients comprise a rather heterogeneous cohort, and may have largely variable risk profiles based on the presence (or absence) of overlooked subclinical cardiovascular risk factors or genetically determined subtle alterations at the cellular or molecular level. Whether the implementation of various cardiac imaging techniques, biomarkers and genetic information could improve the prediction of risk for incident AF and risk assessment of 'lone' AF patients, and influence the treatment decisions needs further research. In this review, we summarise the current knowledge on 'lone' AF, highlight the existing inconsistencies in the field and discuss the prognostic and treatment implications of recent insights in 'lone' AF pathophysiology. © 2013 John Wiley & Sons Ltd.

Vidovic D.,Jaroslav Cerni Institute for the Development of Water Resources | Dimkic M.,Jaroslav Cerni Institute for the Development of Water Resources | Pusic M.,University of Belgrade
Journal of Computational Physics | Year: 2011

A non-linear finite volume method with monotone matrix for the diffusion equation is presented. It does not extrapolate the primary variable to Neumann boundaries, as this was previously done in similar methods. This change results in faster convergence. Computation time is significantly shortened further using the reduced rank extrapolation method (RRE), and imposing an upper limit on the number of linear iterations per non-linear step. Second-order accuracy and performance improvement are demonstrated by numerical examples. © 2011 Elsevier Inc.

Lausevic Z.,Vinca Institute of Nuclear Sciences | Apel P.Y.,Joint Institute for Nuclear Research | Krstic J.B.,University of Belgrade | Blonskaya I.V.,Vinca Institute of Nuclear Sciences
Carbon | Year: 2013

Activation effects on carbon films, derived from commercial aromatic polyimide films (Kapton, DuPont), in CO2 atmosphere at 1203 K on capacitance properties were studied. Two thicknesses of polyimide films were used: 7 and 25 μm. Pore formation during the activation process progresses in two steps due to the existence of a denser surface layer and a more porous core material. In the first step micropores are opening in the dense surface region of the material with average pore diameter smaller than 1 nm. During the second step, mesopores start opening, while micropore volume remains constant with the average micropore diameter of over 1 nm, producing bimodal texture. The first step finishes after 30 min for the thinner samples while for the thicker samples it finishes after 60 min of activation. As a consequence of such textural changes during activation, the thicker sample has a maximum areal capacitance of 0.35 F/cm2. The thinner sample activated for 30 min has a maximum volumetric capacitance of 220 F/cm3 and achieves a maximum gravimetric capacitance of 240 F/g when the texture becomes bimodal after 240 min of activation. These results confirm that activation of carbonized Kapton films gives promising electrode materials for supercapacitors. © 2013 Elsevier Ltd. All rights reserved.

Cvijic S.,Johannes Gutenberg University Mainz | Parojcic J.,University of Belgrade | Langguth P.,Johannes Gutenberg University Mainz
European Journal of Pharmaceutical Sciences | Year: 2014

Concomitant food intake can diminish oral absorption of drugs with limited permeability and an absorption window in the proximal intestine, due to viscosity-mediated decrease in dosage form disintegration time and drug dissolution rate. Three poorly-permeable drugs (atenolol, metformin hydrochloride, and furosemide) exhibiting negative food effect, and one highly-soluble and highly-permeable (metoprolol tartrate), serving as a negative control, were selected for the study. In vitro and in silico tools were used to evaluate the influence of media viscosity on drug bioperformance under fasted and fed conditions. The obtained results demonstrated that increased medium viscosity in the presence of food is one of the key factors limiting oral absorption of drugs with limited permeability and absorption restricted to the upper parts of the intestine, while having negligible effect on pharmacokinetic profile of drugs with pH- and site-independent absorption. Dissolution medium pH 4.6 with the addition of hydroxypropyl methylcellulose was suggested to simulate postprandial gastric conditions for drugs whose solubility under these conditions is not the limiting factor for drug absorption. In addition, drug formulation was found to be an interfering factor in relation to the impact of medium viscosity on the rate and extent of drug absorption. © 2014 Elsevier B.V. All rights reserved.

Brodic D.,University of Belgrade
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

This paper identifies the advantages of the specific approach to water flow algorithm for multi-skewed handwritten text line segmentation. Original water flow algorithm assumes that hypothetical water flows, from both left and right sides of the document image frame, face obstruction from part of character, character, and group of characters in text lines. The stripes of areas left unwetted on the document image frame are finally labeled for the extraction of text lines. However, the method defines parameter water flow angle for flooding which depends on the text line slopes of each specific document. The estimation of the appropriate parameter value is difficult and limited as well. The limitation is manifested by possible election of only 4 values for this parameter. Extended approach has introduced enlargement of the parameter range. Consequently, decision making and the selection of the small values of the parameter below the minimum given by the original method shows improvement in the handwritten text line segmentation process. It is confirmed by the measurement on different types of letters. © 2011 Springer-Verlag Berlin Heidelberg.

Spasojevic I.,University of Belgrade
Redox Report | Year: 2016

Here, I address the topic of suitability for redox research of common settings in cell cultures. This is done through the prism of in vitro anticancer effects of vitamin C. Cell culture media show lower concentrations of iron and a higher level of oxygen compared to interstitial fluid. Such a setup promotes ascorbate-mediated production and accumulation of hydrogen peroxide, which efficiently kills a variety of cancer cell lines. However, the anticancer effects are annihilated if the iron level is corrected to mimic in vivo concentrations. It appears that the potential benefits of application of vitamin C in cancer treatment have been significantly overestimated. This might be true for other pro-oxidative agents as well, such as some (poly)phenols. We urgently need to establish medium formula and culture maintenance settings that are optimal for redox research. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Lazarevic M.P.,University of Belgrade
International Journal of Non-Linear Mechanics | Year: 2015

The modern dynamical systems of various physical natures, such as natural, social, economic, and technical ones, are complexes of various subsystems. They are connected by processes of intensive dynamic interaction and exchange of energy, matter, and information and incorporate nonlinear dynamics, memory, complicated transients, bifurcation and chaotic motion modes. Particularly, synergetics as a very young discipline deals with complex systems, i.e. it is concerned with the spontaneous formation of macroscopic spatial, temporal, or functional structures of systems via self-organization and is associated with systems composed of many subsystems, which may be of quite different natures. Synergetics take into account deterministic processes as treated in the dynamic systems theory including bifurcation theory, catastrophy theory, as well as basic notions of the chaos theory and develops its own approaches. Here, the fundamental basis of nonlinear theory of system's synthesis based on synergetics as well as fractional calculus approach in modern control theory together with its application will be presented. The difference of synergetic approach from the classical scientific methods is in identification of the fundamental role of self-organization in nonlinear dynamic systems and it is necessary to keep the conceptual correspondence to the main qualities of self-organization: nonlinearity - open systems - coherence. Synergetic approach is based on the natural homeostatic-conservation of the internal qualities of the dynamic systems of various natures. Namely, Russian scientist A.A. Kolesnikov developed a novel synergetic approach based on the ideas of modern mathematics, cybernetics, and synergetics to the synthesis of control systems for nonlinear, multidimensional and multilinked dynamic systems of various natures. The synergetic approach to control theory (synergetic control theory-SCT) is a novel nonlinear control method where the nonlinearities of a system are considered in the control design and a systematic design procedures. The invariants (synergies) and attractors, introduced as the main element of SCT, allow establishing direct link to the energy conservation laws, i.e. to the fundamental qualities of various objects. So, invariants, self-organization, and cascade synthesis are the fundamental notions of the SCT determining its essence, novelty, and content. Also, fractional calculus (FC) has a long history of three hundred years, over which a firm theoretical foundation has been established. All fractional operators consider the entire history of the process being considered, thus being able to model the non-local and distributed effects often encountered in natural and technical phenomena and they provide an excellent instrument for description of the memory, heredity, non-locality, self-similarity, and stochasticity of various materials and processes. Fractional dynamics can be encountered in various nonlinear dynamical systems such as visco-elastic materials, electrochemical processes, thermal systems, transmission and acoustics, chaos and fractals, biomechanical systems, and many others. The fractional dynamic systems with nonlinear control represent a relatively new class of applications of the FC which certified the FC as being a fundamental tool in describing the dynamics of complex systems as well as in advanced nonlinear control theory. © 2014 Elsevier Ltd. All rights reserved.

Sekulic D.,University of Split | Spasic M.,University of Split | Mirkov D.,University of Belgrade | Cavar M.,University of Mostar | Sattler T.,University of Ljubljana
Journal of Strength and Conditioning Research | Year: 2013

Sekulic, D, Spasic, M, Mirkov, D, Cavar, M and Sattler, T. Gender-specific influences of balance, speed, and power on agility performance. J Strength Cond Res 27(3): 802-811, 2013-The quick change of direction (i.e., agility) is an important athletic ability in numerous sports. Because of the diverse and therefore hardly predictable manifestations of agility in sports, studies noted that the improvement in speed, power, and balance should result in an improvement of agility. However, there is evident lack of data regarding the influence of potential predictors on different agility manifestations. The aim of this study was to determine the gender-specific influence of speed, power, and balance on different agility tests. A total of 32 college-aged male athletes and 31 college-aged female athletes (age 20.02 ± 1.89 years) participated in this study. The subjects were mostly involved in team sports (soccer, team handball, basketball, and volleyball; 80% of men, and 75% of women), martial arts, gymnastics, and dance. Anthropometric variables consisted of body height, body weight, and the body mass index. Five agility tests were used: a t-test (T-TEST), zigzag test, 20-yard shuttle test, agility test with a 180-degree turn, and forward-backward running agility test (FWDBWD). Other tests included 1 jumping ability power test (squat jump, SQJ), 2 balance tests to determine the overall stability index and an overall limit of stability score (both measured by Biodex Balance System), and 2 running speed tests using a straight sprint for 10 and 20 m (S10 and S20, respectively). A reliability analysis showed that all the agility tests were reliable. Multiple regression and correlation analysis found speed and power (among women), and balance (among men), as most significant predictors of agility. The highest Pearson's correlation in both genders is found between the results of the FWDBWD and S10M tests (0.77 and 0.81 for men and women, respectively; p < 0.05). Power, measured using the SQJ, is significantly (p < 0.05) related to FWDBWD and T-TEST results but only for women (20.44; 20.41). The balance measures were significantly related to the agility performance for men but not for women. In addition to demonstrating a known relationship between speed and agility in both genders, and a small but statistically significant relationship between power and agility in women, these results indicate that balance should be considered as a potential predictor of agility in trained adult men. © 2013 National Strength and Conditioning Association.

Rakic V.,University of Belgrade
Journal of Medical Ethics | Year: 2014

I discuss the argument of Persson and Savulescu that moral enhancement ought to accompany cognitive enhancement, as well as briefly addressing critiques of this argument, notably by John Harris. I argue that Harris, who believes that cognitive enhancement is largely sufficient for making us behave more morally, might be disposing too easily of the great quandary of our moral existence: the gap between what we do and what we believe is morally right to do. In that regard, Persson and Savulescu's position has the potential to offer more. However, I question Persson and Savulescu's proposal of compulsory moral enhancement (a conception they used to promote), proposing the alternative of voluntary moral enhancement.

Stevanovic V.,University of Belgrade
Spatium | Year: 2011

On a broader scale, the aim of this paper is to examine theoretically the effects a cultural context has on the aesthetic experience of images existing in perceived reality. Minimalism in architecture, as direct subject of research, is a field of particularities in which we observe functioning of this correlation. Through the experiment with the similarity phenomenon, the paper follows specific manifestations of general formal principles and variability of meaning of minimalism in architecture in limited areas of cultural backgrounds of Serbia and Japan. The goal of the comparative analysis of the examples presented is to indicate the conditions that may lead to a possibly different aesthetic experience in two different cultural contexts. Attribution of different meanings to similar formal visual language of architecture raises questions concerning the system of values, which produces these meanings in their cultural and historical perspectives. The establishment of values can also be affected by preconceptions resulting from association of perceived similarities. Are the preconceptions in aesthetic reception of architecture conditionally affected by pragmatic needs, symbolic archetypes, cultural metaphors based on tradition or ideologically constructed dogmas? Confronting philosophical postulates of the Western and Eastern traditions with the transculturality theory of Wolfgang Welsch, the answers may become more available.

Zekovic D.N.,University of Belgrade
International Journal of Non-Linear Mechanics | Year: 2015

The work analyzes energy relations for nonholonomic systems, whose motion is restricted by nonlinear nonholonomic constraints. For the mechanical systems with linear constraints, the analysis of energy relations was carried out in [1-6].... On the basis of corresponding Lagrange's equations, a general law of the change in energy dε/dt is formulated for mentioned systems by the help of which it is shown that there are two types of the laws of conservation of energy, depending on the structure of elementary work of the forces of constraint reactions. Also, the condition for existing the second type of the law of conservation of energy is formulated in the form of the system of partial differential equations. The obtained results are illustrated by a model of nonholonomic mechanical system. © 2014 Elsevier Ltd. All rights reserved.

Stijepovic M.Z.,Texas A&M University at Qatar | Linke P.,Texas A&M University at Qatar | Kijevcanin M.,University of Belgrade
Energy and Fuels | Year: 2010

The new approach for simulation and optimization of a continuous catalytic regenerative (CCR) reformer process is proposed. Typical CCR reforming processes consist of three to four reactors with recycle. The reaction patterns and reactors are typicallymodeled using a system of partial differential equations (PDEs). The numerical simulation solution of the entire model for a process system consisting of multiple reaction zoneswith recycle is extremely time-consuming and, thus, impractical in optimization studies.That iswhy we proposed amore efficient simulation and optimization scheme based on quasi-steady-state assumptions. We define criteria for reactor fragmentation to avoid the introduction of large errors in the quasi-steady-state calculations. The optimization problem is formulated with the objective of minimizing fuel consumption. The employed objective function constitutes a combined measure for economic and environmental performance. It is shown that the proposed approach identifies considerable improvements for the process. © 2010 American Chemical Society.

Cao G.,Yale University | Cao G.,University of Texas at Austin | Platisa J.,John B Pierce Laboratory | Platisa J.,University of Belgrade | And 5 more authors.
Cell | Year: 2013

Nervous systems process information by integrating the electrical activity of neurons in complex networks. This motivates the long-standing interest in using optical methods to simultaneously monitor the membrane potential of multiple genetically targeted neurons via expression of genetically encoded fluorescent voltage indicators (GEVIs) in intact neural circuits. No currently available GEVIs have demonstrated robust signals in intact brain tissue that enable reliable recording of individual electrical events simultaneously in multiple neurons. Here, we show that the recently developed "ArcLight" GEVI robustly reports both subthreshold events and action potentials in genetically targeted neurons in the intact Drosophila fruit fly brain and reveals electrical signals in neurite branches. In the same way that genetically encoded fluorescent sensors have revolutionized the study of intracellular Ca2+ signals, ArcLight now enables optical measurement in intact neural circuits of membrane potential, the key cellular parameter that underlies neuronal information processing. © 2013 Elsevier Inc.

Jankovic S.,University of Belgrade
The International journal of periodontics & restorative dentistry | Year: 2013

Risk factors such as smoking, genetic factors, and tissue biotype play an important role in the etiology, predictability, and long-term stability of gingival recession treatment. This study was designed to evaluate the influence of interleukin 1 (IL-1) polymorphism and smoking on the stability of gingival recession treatment after 1 and 3 years. All patients (n = 55) were treated for type I and II recession defects using a connective tissue graft. Clinical evaluations were performed, which included assessment of vertical recession depth, gingival inflammation, and clinical attachment level. A fingerstick blood sample was collected using specially provided DNA filter paper and mailed for processing in a laboratory using polymerase chain reaction-based methodology. The results indicated that 19 subjects were genotype positive (34.5%). Treatment of the localized recessions was effective and provided a similar amount of coverage in genotype-positive and genotype-negative subjects within smoking and nonsmoking groups after 1 year. In a 3-year period, nonsmoking patients with positive IL-1 genotype lost approximately 20% of the root coverage gained at 1 year and were almost four times more inferior compared with genotype-negative patients. Patients who smoked and had a positive IL-1 genotype lost approximately 35% of the gained root coverage. IL-1 polymorphism and smoking habit did not affect gingival recession treatment at 1 year but had a great impact on long-term stability.

Brodic D.,University of Belgrade
Revista Facultad de Ingenieria | Year: 2015

The paper considers the level of the extremely low frequency magnetic fi eld produced by the portable computers. Accordingly, the magnetic fi eld characterized with the low frequencies up to 300 Hz has been measured. The experiment consists of testing 10 different portable computers in normal operating condition and under heavy load. The measurement of the magnetic fi eld is performed in the laptop neighborhood. The measured data are presented and discussed. They are compared with the magnetic fi eld safe limit values suggested by MPR II, TCO, ICNIRP, the SMEMSP (Serbian Ministry of Environment, Mining and Spatial Planning), and those given in the literature. It is shown that some of the portable computers radiate a very strong magnetic fi eld. Hence, they should be used with caution.

Popovic D.M.,University of Belgrade
Amino Acids | Year: 2013

The function of cytochrome c oxidase as a biomolecular nanomachine that transforms energy of redox reaction into protonmotive force across a biological membrane has been subject of intense research, debate, and controversy. The structure of the enzyme has been solved for several organisms; however details of its molecular mechanism of proton pumping still remain elusive. Particularly, the identity of the proton pumping site, the key element of the mechanism, is still open to dispute. The pumping mechanism has been for a long time one of the key unsolved issues of bioenergetics and biochemistry, but with the accelerating progress in this field many important details and principles have emerged. Current advances in cytochrome oxidase research are reviewed here, along with a brief discussion of the most complete proton pumping mechanism proposed to date, and a molecular basis for control of its efficiency. © 2013 Springer-Verlag Wien.

Atrial fibrillation (AF) commonly co-exists with heart failure (HF). The risk factors for and prognostic implications of incident HF development in patients with first-diagnosed AF and structurally normal hearts are poorly defined. In a cohort of patients with first-diagnosed AF and structurally normal hearts on baseline echocardiography, we investigated baseline risk factors for the development of incident HF and tested the hypothesis that incident HF was an independent predictor of adverse outcomes during a mean 10-year follow-up period. This was a registry-based, observational cohort study of 842 patients initially diagnosed between 1992 and 2007 (mean age 51.6 ± 12.4 years), whereby 83 (9.9%) developed HF. The linearized rate of incident HF was 0.97% [95% confidence interval (CI) 0.78-1.19%] per 100 patient-years. Baseline history of hypertension, diabetes mellitus, dilated left atrium, and low-normal LVEF (50-54%) were multivariable predictors of subsequent HF (all P < 0.05). HF development was significantly associated with increased number of hospitalizations, AF progression, any stroke/peripheral thrombo-embolism, ischaemic stroke, cardiovascular death, and all-cause mortality (all P < 0.001). Kaplan-Meier 10-year estimates of survival free of the composite endpoint of AF progression, thrombo-embolism, and mortality were significantly worse for AF patients with incident HF compared with those without HF (68.8%; 95% CI 64.7-72.9 vs. 25.9% 95% CI 15.7-36.1, P < 0.001). Underlying co-morbidities or subtle alterations such as mild left atrial dilatation or low-normal LVEF in the absence of overt underlying heart disease are baseline independent risk factors for incident HF during a long-term follow-up. Incident HF was an independent predictor of adverse outcomes in patients initially diagnosed with first-diagnosed AF and structurally normal hearts. These findings could facilitate the identification of AF patients at increased risk for adverse outcomes within the cohort perceived as being at 'low risk' given a structurally normal heart on echocardiography.

Net fluxes of Ca2+ and H+ ions were measured non-invasively close to the surface of Phycomyces blakesleeanus sporangiophores stage I using ion-selective vibrating microelectrodes. The measurements were performed on a wild type (Wt) and a gravitropic mutant A909 kept in either vertical or tilted orientation. Microelectrodes were positioned 4 μm from the surface of sporangiophore, and ion fluxes were recorded from the apical (0-20 μm) and subapical (50-100 μm) regions. The magnitude and direction of ionic fluxes measured were dependent on the distance from the tip along the growing zone of sporangiophore. Vertically oriented sporangiophores displayed characteristic tip-to-base ion fluxes patterns. Ca2+ and H+ fluxes recorded from apical region of Wt sporangiophores were inward-directed, while ion fluxes from subapical locations occurred in both directions. In contrast to Wt, mutant A909 showed opposite (outward) direction of Ca2+ fluxes and reduced H+ influxes in the apical region. Following gravistimulation, the magnitude and direction of ionic fluxes were altered. Wt sporangiophore exhibited oppositely directed fluxes on the lower (influx) and the upper (efflux) sides of the cell, while mutant A909 did not show such patterns. A variable elongation growth in vertical position and reduced growth rate upon gravistimulation were observed in both strains. The data show that tip-growing sporangiophores exhibit a tip-to-base ion flux pattern which changes characteristically upon gravistimulation in Wt in contrast to the mutant A909 with a strongly reduced gravitropic response. © 2012 Springer-Verlag.

Knezevic-Jugovic Z.D.,University of Belgrade
Methods in molecular biology (Clifton, N.J.) | Year: 2011

A selection of the best combination of adequate immobilization support and efficient immobilization method is still a key requirement for successful application of immobilized enzymes on the industrial level. Eupergit) supports exhibit good mechanical and chemical properties and allow establishment of satisfactory hydrodynamic regime in enzyme reactors. This is a good recommendation for their wide application in enzyme immobilization after finding the most favorable immobilization method. Methods for enzyme immobilization that have been previously reported as efficient, considering the obtained activity of immobilized enzyme are presented: direct binding to polymers via their epoxy groups, binding to polymers via a spacer made from ethylene diamine/glutaraldehyde, and coupling the periodate-oxidized sugar moieties of the enzymes to the polymer beads.

Ajdzanovic V.Z.,University of Belgrade
General physiology and biophysics | Year: 2012

Advanced age is often accompanied by glucocorticoid excess which contributes to the pathogenesis of the metabolic syndrome associated with some hemodynamic disorders. Impaired central regulation of stress hormones secretion and increased glucocorticoids/adrenal androgens ratio trigger hyperglycemia, elevated blood lipids and visceral fat accumulation, associated with hypertension and increased blood viscosity, all of which represent cardiovascular morbidity factors in this age. Finding the adequate therapeutic solutions is set as an imperative in the treatment of listed symptoms. Biologically active soy isoflavones, exhibiting estrogen- and membrane-receptor agonistic/antagonistic activity, and antioxidative and tyrosine kinase/steroidogenic enzyme inhibiting effects, appear as alternative therapeutics for various ageing-related diseases. It has been shown that soy isoflavones reduce some of the listed risk factors, while affecting the hemodynamic group of cardiovascular parameters directly, as well as indirectly via endocrine perturbations. Soy isoflavones may reverse the glucocorticoids/adrenal androgens ratio, lower serum cholesterol, slow the development of atherosclerotic plaque formation, inhibit platelet aggregation, increase cardiac contractility, but they may have diverse effects on blood viscosity and may increase triglyceride levels. Herein, we present the projection of soy isoflavones-based therapy of glucocorticoid excess and disturbed hemodynamics in advanced age, concluding that although promising, it requires the impartial approach and certain precautions.

Milinkovic Z.B.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2010

The goals of surgery for spinal deformity are to correct or improve the deformity to get a stable, balanced and fused spine. The long-term success of any procedure for scoliosis depends on a solid arthrodesis. Getting fusion of the instrumented segment with the aid of copious autogenous iliac graft has been the most important goal of treatment. However, harvesting copious graft from teenage iliac bone has its limitation in the quantity of graft, surgical time, and other complications of graft sites. Bone substitute is a promising concept, but there is not ideal bone substitute with all the characteristics of an autogenous bone graft. Several alternative graft materials like tricalcium phosphate, hydroxyapatite, and demineralized bone matrix have osteoinductive properties. Bone morphogenic protein has osteoconductive properties. The limitations with bone substitutes are osteoinduction and osteoconduction properties, sterilization, chances of transmitting infective disease and cost. We consider that the introduction of segmental spinal instrumentation which enables strong and firm correction and fixation of the scoliotic deformity has enabled getting fusion with less graft. We can obtain that quantity of graft after laminae and spinous process decortication. This retrospective study has been done in our hospital from January 2002 to December 2004. A total of 188 patients underwent posterior corrections for adolescent idiopathic scoliosis using segmental fixation by Moss-Miami. No autogenous iliac crest graft was taken or graft substitutes. After meticulous decortication and destruction of facet joints, we used local graft taken from spinous process and laminae. All patients had minimum thirty months follow-up. We have excellent results. Out of these 188 patients, 177 patients have fused spine, no implant failure, no pain, no infection and no loss of correction. Eleven (5.8%) patients underwent re-operation; four among them because of infection, three for symptomatic implants and four due to pseudarthrosis. We consider that the use of local harvesting graft is enough for getting good spondylodesis.

Sljukic B.,University of Lisbon | Milikic J.,University of Belgrade | Santos D.M.F.,University of Lisbon | Sequeira C.A.C.,University of Lisbon
Electrochimica Acta | Year: 2013

Electrochemical oxidation of sodium borohydride (NaBH4) at carbon-supported platinum (Pt/C) and carbon-supported bimetallic platinum alloys (Pt0.75M0.25/C, with M = Ni or Co) is studied in alkaline media using cyclic voltammetry and linear scan voltammetry with rotating disc electrode. Main kinetic parameters (e.g., charge transfer coefficients, number of electrons exchanged, standard heterogeneous rate constants and activation energies) for NaBH4 oxidation on these electrocatalysts are determined. Results indicate the highest catalytic activity of Pt 0.75Ni0.25/C alloy electrocatalyst, followed by Pt 0.75Co0.25/C, while the lowest activity is observed for Pt/C electrocatalyst. The influence of electrolyte composition and temperature on NaBH4electrooxidation at the three materials is also explored. The good performance of these bimetallic alloys makes them a lower cost alternative to single Pt as electrocatalysts for the direct borohydride fuel cell anode. © 2013 Elsevier Ltd. All rights reserved.

Vukmirovic N.,Lawrence Berkeley National Laboratory | Vukmirovic N.,University of Belgrade | Wang L.-W.,Lawrence Berkeley National Laboratory
Journal of Physical Chemistry B | Year: 2011

We present large-scale calculations of electronic structure of strongly disordered conjugated polymers. The calculations have been performed using the density functional theory based charge patching method for the construction of single-particle Hamiltonian and the overlapping fragments method for the efficient diagonalization of that Hamiltonian. We find that the hole states are localized due to the fluctuations of the electrostatic potential and not by the breaks in the conjugation of the polymer chain. The tail of the density of hole states exhibits an exponentially decaying behavior. The main features of the electronic structure of the system can be described by an one-dimensional nearest neighbor tight-binding model with a correlated Gaussian distribution of on-site energies and constant off-site coupling elements. © 2011 American Chemical Society.

Blazencic J.,University of Belgrade
Botanica Serbica | Year: 2014

The study provides insights into stoneworts of Serbia (1851-2013). For each taxon, the synonym(s), distribution, threat factors and the IUCN threat category is given. In Serbia, 23 species are present of ca. 400 known worldwide. © 2014 Institute of Botany and Botanical Garden Jevremovac, Belgrade.

Golovatch S.I.,RAS A.N. Severtsov Institute of Ecology and Evolution | Makarov S.E.,University of Belgrade
Arthropoda Selecta | Year: 2011

Two new species of the Mediterranean genus Anamastigona are being described: A. ter-raesanctae sp.n. from Israel, and A. mauriesi sp.n. from Abkhazia, Caucasus. At present, both of these species are the easternmost representatives of this genus, while the one from Israel is simultaneously the first and south-easternmost member of the order Chordeumatida in the diplopod fauna of the entire Near East. The new species from Abkhazia is the first record of Anamastigona in the Caucasus, one of the long acknowledged centres of an-throleucosomatid generic and species differentiation globally. The following new synonymy is formalized: Ana-mastigona aspromontis (Strasser, 1970) = A. meridio-nalis Silvestri, 1898, syn.n., and Anamastigona halophi-la (Verhoeff, 1940) = A. bilselii (Verhoeff, 1940), syn.n. (the valid names in the right). © arthropoda selecta, 2011.

Batas Bjelic I.,University of Belgrade
Renewable and Sustainable Energy Reviews | Year: 2014

With the Law on Energy and its acceptance by the Covenant of Mayors, local authorities in Serbia are obliged to prepare action plans for the development of distributed generation and energy efficiency measures aiming at reducing CO2 emissions. The development of distributed generation (wind, photovoltaic, hydro and combined heat and power plant) is an asset to the local authorities wishing to become energy independent microgrids that could relieve the national transmission grid in the way of reducing amount of electricity to be transported from centralized generation to the end-user. Using the simulation tool HOMER, an optimal configuration plan of the municipal microgrids for Serbia has been drawn, in order to obtain the lowest total net present costs during the planning period under various levels of CO2 reduction constraint. The increase of the end-user specific costs for energy has been quantified in a sensitivity analysis based on this constraint in the local authority microgrid. © 2014 Elsevier Ltd.

Djordjevic M.,University of Belgrade
Physical Review Letters | Year: 2014

Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which - contrary to pQCD expectations - may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data. © 2014 American Physical Society.

Maric N.P.,University of Belgrade | Svrakic D.M.,University of Washington
Psychiatria Danubina | Year: 2012

Schizophrenia (SZ) is a highly heritable disorder, with about 80% of the variance attributable to genetic factors. There is accumulating evidence that both common genetic variants with small effects and rare genetic lesions with large effects determine risk of SZ. As recently shown, thousands of common single nucleotide polymorphisms (SNPs), each with small effect, cumulatively could explain about 30% of the underlying genetic risk of SZ. On the other hand, rare and large copy number variants (CNVs) with high but incomplete penetrance, variable in different individual, could explain about additional 30% of SZ cases. Although these rare CNVs frequently develop de novo, it is not clear whether they affect risk independently or via interaction with a polygenic liability in the background. Finally, the role of environmental risk factors has been well established in SZ. Environmental factors are rarely sufficient to cause SZ independently, but act in parallel or in synergy with the underlying genetic liability. Epigenetic misregulation of the genome and direct CNS injury are probably the main mechanism to mediate prenatal environmental effects (e.g., viruses, ethanol, or nutritional deficiency) whereas postnatal risk factors (e.g., stress, urbanicity, cannabis use) may also affect risk via usebased potentiation of vulnerable CNS pathways implicated in SZ. In this review, we outline a general theoretical background of epigenetic mechanisms involved in GxE interactions, and then discuss epigenetic and neurodevelopmental features of SZ based on available information from genetics, epigenetics, epidemiology, neuroscience, and clinical research. We argue that epigenetic model of SZ provides a framework to integrate a variety of diverse empirical data into a powerful etiopathogenetic synthesis. The promising future of this model is the possibility to develop truly specific prevention and treatment strategies for SZ. © Medicinska naklada.

Potpara T.S.,University of Belgrade | Lip G.Y.H.,University of Birmingham
Best Practice and Research: Clinical Haematology | Year: 2013

Atrial fibrillation (AF) confers a significant risk of stroke or systemic thromboembolism. Oral anticoagulation is the most effective therapy for AF-related stroke prevention. A decision to advise oral anticoagulation should be based upon the individual absolute risks of stroke and bleeding, and almost all AF patients with ≥1 stroke risk factors have a positive net clinical benefit of oral anticoagulation. The novel oral anticoagulants (NOACs) dabigatran, rivaroxaban and apixaban are more convenient, and are at least equally effective and safer (regarding bleeding complications) for stroke prevention compared with vitamin K antagonists (VKAs). Availability of NOACs and improved stroke and bleeding risks assessment should increase the number of AF patients who receive adequate thromboprophylaxis. In this review article, we present an overview of the clinical phase III trials with NOACs for stroke prevention and discuss the contemporary principles of thromboprophylaxis in AF patients with various stroke and bleeding risk profiles, as well as practical aspects of NOACs therapy. © 2013 Elsevier Ltd. All rights reserved.

Radetic M.,University of Belgrade
Journal of Materials Science | Year: 2013

Nanoparticles gained much scientific attention in the past decade due to their specific surface chemistry and properties which are significantly different from that of the corresponding bulk materials. Silver nanoparticles were the most extensively studied and they can be already found in a wide range of commercially available products. This article reviews the latest developments in finishing of textile materials with differently synthesized silver nanoparticles. Although antimicrobial activity of functionalized textile materials was primarily discussed, the possibilities to apply silver nanoparticles as a colorant or antistatic agent were also evaluated. In addition, the effect of chemical and physico-chemical activation of fibers before loading of silver nanoparticles on their binding efficiency was considered. Taking into account the importance of environmental impact of novel technologies, potential environmental risks emerging from silver release during washing of textile materials have been also discussed. © 2012 Springer Science+Business Media, LLC.

Radetic M.,University of Belgrade
Journal of Photochemistry and Photobiology C: Photochemistry Reviews | Year: 2013

Extraordinary photocatalytic activity, non-toxicity, high availability, biocompatibility, and low price make TiO2 nanoparticles particularly attractive for manufacturing of different high value-added products. During the past several years, many efforts have been made to immobilize TiO2 nanoparticles onto textile materials with an aim to produce goods with multifunctional properties such as UV protective, self-cleaning and antibacterial. The processing of textile materials with TiO2 nanoparticles is relatively simple, but insufficient binding efficiency between certain fibers and TiO2 nanoparticles imposes a problem concerning the stability and durability of nanocomposite systems during their exploitation. Therefore, recent studies were more oriented toward chemical and physico-chemical modification of fiber surfaces that may enhance the binding efficiency of TiO2 nanoparticles. This article looks at some latest advances in finishing of different textile materials with TiO2 nanoparticles. © 2013 Elsevier B.V.

Jovic D.M.,University of Munster | Jovic D.M.,University of Belgrade | Denz C.,University of Munster | Belic M.R.,Texas A&M University at Qatar
Optics Letters | Year: 2012

Anderson localization (AL) of light is investigated numerically in a disordered parity-time (PT )-symmetric potential, in the form of an optical lattice. The lattice is recorded in a nonlinear medium with Kerr nonlinearity. We demonstrate enhancement of light localization in a PT -symmetric lattice, as compared to the localization in the corresponding real lattice. The effect of strength of the gain-loss component in the PT lattice on various regimes of AL is also discussed. It is found that the localization exists and is further enhanced above the threshold strength of the imaginary part of the potential. The influence of nonlinearity and disorder level on the transverse localization of light in such a complex-valued potential is addressed. © 2012 Optical Society of America.

Rasuo B.,University of Belgrade
Transactions of the Japan Society for Aeronautical and Space Sciences | Year: 2012

The establishment of exact two-dimensional flow conditions in wind tunnels is a very difficult problem. This has been evident for wind tunnels of all types and scales. In this paper, the principal factors that influence the accuracy of two-dimensional wind tunnel test results are analyzed. The influences of the Reynolds number, Mach number and wall interference with reference to solid and flow blockage (blockage of wake) as well as the influence of side-wall boundary layer control are analyzed. Interesting results are brought to light regarding the Reynolds number effects of the test model versus the Reynolds number effects of the facility in subsonic and transonic flow. © 2012 The Japan Society for Aeronautical and Space Sciences.

Elezovic I.,University of Belgrade
Srpski arhiv za celokupno lekarstvo | Year: 2010

Acquired inhibitors against coagulation factor VIII (FVIII), also termed acquired haemophilia A, neutralize its procoagulant function and result in severe or often life-threatening bleeding. The antibodies arise in individuals with no prior history of clinical bleeding. Acquired haemophilia occurs rarely with the incidence of approximately 1 to 4 per million/year, with severe bleeds in up to 90% of affected patients, and high mortality between 8-22%. About 50% of diagnosed patients were previously healthy, while the remaining cases may be associated with postpartum period, autoimmune diseases, malignancy, infections, or medications. Most patients have spontaneous haemorrhages into the skin, muscles or soft tissues, and mucous membranes, or after trauma and surgery, whereas haemarthroses are uncommon. The diagnosis of acquired haemophilia A based on the prolongation of activated partial thromboplastin time which does not normalize after the addition of normal plasma, reduced FVIII, with evidence of FVIII inhibitor measured by the Bethesda assay (Nijmegen modification). The treatment of acute bleeding episodes and the long-term eradication of the autoantibodies in acquired haemophilia are the main therapeutic strategy. Two options are currently available for acute bleeding control: the use rFVIIa or FEIBA in patients with higher inhibitor titer (> 5 BU), or to raise the level of FVIII by administration of DDAVP or concentrates of FVIII in patients with low level of inhibitors (< 5 BU). Treatment with FEIBA (50-100 IU/ kg every 8-12 hours) has shown good haemostatic response in 76-89% of the bleeding episodes. Patients treated with rFVIIa (90 microg/kg every 2-6 hours) have achieved good response in 95-100% as a first-line, and 75-80% as a salvage therapy. Patients with low inhibitor titer and lower response can be treated with concentrate of FVIII in the recommended dose of 40 IU/kg plus 20 IU/kg for each BU of inhibitor. The treatment of non-life-threatening haemorrhages with desmopressin (DDAVP 0.3 microg/kg) may increase both FVIII and vWF. Sometimes inhibitors disappear spontaneously, but long-term management is necessary for eradication of inhibitors by immunosuppression (prednisone 1 mg/kg 3 weeks alone or in combination cyclophosphamide 2 mg/kg), immunomodulation, intravenous immunoglobulin (HD IgG 2 g/kg 2 or 5 d), physical removal of antibodies (plasmapheresis or immunoadsorption), or various combinations. Recently, a therapy with rituximab, an anti-CD20 monoclonal antibody, has shown to be effective in acquired haemophilia.

Batalovic V.,University of Belgrade
Journal of Tribology | Year: 2010

Erosion wear is a process that accompanies the facility for hydraulic transportation of solids. Since the pump is one of the vital parts of this facility, the working life of the pump is conditioned by the amount of wear. The working life can be realized only if the parameters chosen, for the pump elements, slurry, and transport conditions, will provide economic transport with minimal wear. Testing is the most reliable method for acquiring valid data. The two issues that need to be solved while planning the testing process are the choice of valid similarity criteria (test-industrial facility) and data selection. After the theoretical analyses, technically acceptable similarity criteria are obtained. A group of data needs to be defined through the experiment. © 2010 by ASME.

Pantic I.,University of Belgrade
Reviews on Advanced Materials Science | Year: 2010

Despite intensive research efforts, cancer remains one of the leading causes of death in the world. Many new methods and techniques have been developed in order to improve diagnosis and treatment, often promising in the beginning, but with limited results during the course of their application. This concise review focuses on novel approaches in development and production of magnetic nanoparticals, as well as their application in today's cancer diagnosis and treatment. © 2010 Advanced Study Center Co. Ltd.

Kukavica B.M.,University of Banja Luka | Veljovic-Jovanovic S.D.,University of Belgrade | Menckhoff L.,University of Hamburg | Luthje S.,University of Hamburg
Journal of Experimental Botany | Year: 2012

Cell wall isolated from pea roots was used to separate and characterize two fractions possessing class III peroxidase activity: (i) ionically bound proteins and (ii) covalently bound proteins. Modified SDS-PAGE separated peroxidase isoforms by their apparent molecular weights: four bands of 56, 46, 44, and 41 kDa were found in the ionically bound fraction (iPOD) and one band (70 kDa) was resolved after treatment of the cell wall with cellulase and pectinase (cPOD). Isoelectric focusing (IEF) patterns for iPODs and cPODs were significantly different: five iPODs with highly cationic pI (9.5-9.2) were detected, whereas the nine cPODs were anionic with pI values between pH 3.7 and 5. iPODs and cPODs showed rather specific substrate affinity and different sensitivity to inhibitors, heat, and deglycosylation treatments. Peroxidase and oxidase activities and their IEF patterns for both fractions were determined in different zones along the root and in roots of different ages. New iPODs with pI 9.34 and 9.5 were induced with root growth, while the activity of cPODs was more related to the formation of the cell wall in non-elongating tissue. Treatment with auxin that inhibits root growth led to suppression of iPOD and induction of cPOD. A similar effect was obtained with the widely used elicitor, chitosan, which also induced cPODs with pI 5.3 and 5.7, which may be specifically related to pathogen defence. The differences reported here between biochemical properties of cPOD and iPOD and their differential induction during development and under specific treatments implicate that they are involved in specific and different physiological processes. © 2012 The Author(s).

Market pressures for shorter product turnover and faster selling result in modified production practices of Serbian traditional dry, cured beef ham known as " govedja prŠuta" . These are mainly characterized by incomplete maturation and drying of the hams, resulting in higher water activity levels of products that require correctly chosen intrinsic and extrinsic factors to control foodborne pathogens. An incidence of almost 90% has been found after the enrichment of . Staphylococcus aureus in 20 tested samples produced by five different producers and marketed in different parts of Serbia. Although important these findings do not completely surprise due to known high prevalence of . S. aureus. However, combined with market-driven shorter and incomplete maturation and drying of the products this high prevalence of low numbers resulted in growth and staphylococcal enterotoxin (SE) production in 35% of samples tested (7/20). Results of the analysis showed that enumerable . S. aureus counts were found only in four out of twenty samples, but with counts ranging from 2.8 to 3.7 log CFU/g suggesting that actual outgrowth and toxin production perhaps occurred earlier in the production stages. Nevertheless, inoculation of enterotoxigenic isolates in the same type of product, previously found negative on the presence of . S. aureus and SE, showed that both growth and SE production can occur even in the final product at 22 °C and 37 °C, but not at 12 °C, regardless of whether vacuum or aerobic packaging of the product was applied. © 2012 Elsevier Ltd.

Korac R.R.,University of Belgrade | Khambholja K.M.,Ganpat University
Pharmacognosy Reviews | Year: 2011

Herbs have been used in medicines and cosmetics from centuries. Their potential to treat different skin diseases, to adorn and improve the skin appearance is well-known. As ultraviolet (UV) radiation can cause sunburns, wrinkles, lower immunity against infections, premature aging, and cancer, there is permanent need for protection from UV radiation and prevention from their side effects. Herbs and herbal preparations have a high potential due to their antioxidant activity, primarily. Antioxidants such as vitamins (vitamin C, vitamin E), flavonoids, and phenolic acids play the main role in fighting against free radical species that are the main cause of numerous negative skin changes. Although isolated plant compounds have a high potential in protection of the skin, whole herbs extracts showed better potential due to their complex composition. Many studies showed that green and black tea (polyphenols) ameliorate adverse skin reactions following UV exposure. The gel from aloe is believed to stimulate skin and assist in new cell growth. Spectrophotometer testing indicates that as a concentrated extract of Krameria triandra it absorbs 25 to 30% of the amount of UV radiation typically absorbed by octyl methoxycinnamate. Sesame oil resists 30% of UV rays, while coconut, peanut, olive, and cottonseed oils block out about 20%. A "sclerojuglonic" compound which is forming from naphthoquinone and keratin is the reaction product that provides UV protection. Traditional use of plant in medication or beautification is the basis for researches and making new trends in cosmetics. This review covers all essential aspects of potential of herbs as radioprotective agents and its future prospects.

Miljkovic D.,University of Belgrade
Archives of Biological Sciences | Year: 2012

I. pumila natural populations usually occur in two different habitat types: dune and forest. These I. pumila habitats differ in many abiotic environmental factors, but mostly in available light intensity and quality. The effects of different light intensity on the developmental stability of I. pumila floral traits were analyzed on clones taken from two different natural light habitat types that were raised in contrasting light treatments in experimental garden conditions (common garden experiment). As an indicator of developmental stability, we used two fluctuating asymmetry indices (FA1 and FA8a) of three bilateral symmetric traits of I. pumila flower (FW-fall width, SW-standard width and STW- style branch width). In addition, statistically significant treatment x population interaction was observed for style width. According to the presented results, the observed FA patterns of particular traits did not reflect the whole organism buffering capacity under the given environmental conditions.

Jankovic B.,University of Belgrade
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2015

Isothermal decomposition process of chemically transforming indium tin oxide (ITO) powders into indium (III) hydroxide powders was investigated. Two types of powders were analyzed, i.e., non-activated and mechanically activated. It has been found that in the case of activated sample, shorter induction periods appear, which permits growth of smaller crystals, while in the case of non-activated sample, long induction periods appear, characterized by the growth of larger crystals. DAEM approach has shown that decomposition processes of non-activated and mechanically activated samples can be described by contracting volume model with a linear combination of two different density distribution functions of apparent activation energies (Ea), and with first-order model, with a single symmetrical density distribution function of Ea, respectively. It was established that specific characteristics of particles not only affect the mechanism of decomposition processes, but also have the significant impact on thermodynamic properties. © 2015 The Nonferrous Metals Society of China.

Cirilo Antonio N.,University of Lisbon | Manojlovic N.,University of Lisbon | Manojlovic N.,University of Algarve | Salom I.,University of Belgrade
Nuclear Physics B | Year: 2014

We implement fully the algebraic Bethe ansatz for the XXX Heisenberg spin chain in the case when both boundary matrices can be brought to the upper-triangular form. We define the Bethe vectors which yield the strikingly simple expression for the off shell action of the transfer matrix, deriving the spectrum and the relevant Bethe equations. We explore further these results by obtaining the off shell action of the generating function of the Gaudin Hamiltonians on the corresponding Bethe vectors through the so-called quasi-classical limit. Moreover, this action is as simple as it could possibly be, yielding the spectrum and the Bethe equations of the Gaudin model. © 2014 The Authors.

Berec V.,University of Belgrade | Berec V.,Vinca Institute of Nuclear Sciences
PLoS ONE | Year: 2012

Selective coherence control and electrically mediated exchange coupling of single electron spin between triplet and singlet states using numerically derived optimal control of proton pulses is demonstrated. We obtained spatial confinement below size of the Bohr radius for proton spin chain FWHM. Precise manipulation of individual spins and polarization of electron spin states are analyzed via proton induced emission and controlled population of energy shells in pure 29Si nanocrystal. Entangled quantum states of channeled proton trajectories are mapped in transverse and angular phase space of 29Si <100> axial channel alignment in order to avoid transversal excitations. Proton density and proton energy as impact parameter functions are characterized in single particle density matrix via discretization of diagonal and nearest off-diagonal elements. We combined high field and low densities (1 MeV/92 nm) to create inseparable quantum state by superimposing the hyperpolarizationed proton spin chain with electron spin of 29Si. Quantum discretization of density of states (DOS) was performed by the Monte Carlo simulation method using numerical solutions of proton equations of motion. Distribution of gaussian coherent states is obtained by continuous modulation of individual spin phase and amplitude. Obtained results allow precise engineering and faithful mapping of spin states. This would provide the effective quantum key distribution (QKD) and transmission of quantum information over remote distances between quantum memory centers for scalable quantum communication network. Furthermore, obtained results give insights in application of channeled protons subatomic microscopy as a complete versatile scanning-probe system capable of both quantum engineering of charged particle states and characterization of quantum states below diffraction limit linear and in-depth resolution. PACS numbers: 03.65.Ud, 03.67.Bg, 61.85.+p, 67.30.hj. © 2012 Vesna Berec.

Redzic D.V.,University of Belgrade
Serbian Astronomical Journal | Year: 2014

We made an attempt to remedy recent confusing treatments of some basic relativistic concepts and results. Following the argument presented in an earlier paper (Redžić 2008b), we discussed the misconceptions that are recurrent points in the literature devoted to teaching relativity such as: there is no change in the object in Special Relativity, illusory character of relativistic length contraction, stresses and strains induced by Lorentz contraction, and related issues. We gave several examples of the traps of everyday language that lurk in Special Relativity. To remove a possible conceptual and terminological muddle, we made a distinction between the relativistic length reduction and relativistic FitzGerald-Lorentz contraction, corresponding to a passive and an active aspect of length contraction, respectively; we pointed out that both aspects have fundamental dynamical contents. As an illustration of our considerations, we discussed briefly the Dewan-Beran-Bell spaceship paradox and the 'pole in a barn' paradox.

Buric M.,University of Belgrade | Wohlgenannt M.,Vienna University of Technology
Journal of High Energy Physics | Year: 2010

We analyze properties of a family of finite-matrix spaces obtained by a truncation of the Heisenberg algebra and we show that it has a three-dimensional, noncommutative and curved geometry. Further, we demonstrate that the Heisenberg algebra can be described as a two-dimensional hyperplane embedded in this space. As a consequence of the given construction we show that the Grosse-Wulkenhaar (renormalizable) action can be interpreted as the action for the scalar field on a curved background space. We discuss the generalization to four dimensions. © 2010 SISSA.

This study was intended to investigate, through resonance frequency analysis (RFA), the stability of implants placed in an early loading protocol via the osteotome sinus floor elevation technique in the posterior maxilla. All implants featured a sandblasted/acid-etched active surface. An early loading protocol was considered for patients in whom implants with a sandblasted, large-grit/acid-etched active surface (SLActive) were placed in the posterior maxilla by the osteotome sinus floor elevation technique. Implant stability, which was measured by RFA at surgery and at weekly intervals for the following 6 weeks, was used as the most significant inclusion criterion. At the end of the stability observation period, only implants with a stability quotient of 65 or higher were loaded. Implants were followed for 2 years. Twenty-seven patients received 42 implants, 40 of which were subjected to an early loading protocol 6 weeks after placement. Two years after loading, all 40 implants were surviving, without clinically or radiographically detectible complications. An early loading protocol can be used for SLActive implants placed in the posterior maxilla via the osteotome sinus floor elevation technique if their stability is confirmed by RFA.

Stosic D.,CNRS Research on Catalysis and Environment in Lyon | Bennici S.,CNRS Research on Catalysis and Environment in Lyon | Rakic V.,University of Belgrade | Auroux A.,CNRS Research on Catalysis and Environment in Lyon
Catalysis Today | Year: 2012

In this work, ceria-niobia mixed oxides have been prepared by coprecipitation. The structural, textural, and surface properties of these materials have been fully characterized using appropriate techniques (low-temperature adsorption-desorption of nitrogen, thermogravimetric analysis, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and temperature-programmed reduction/oxidation (TPR/O)). The acid-base properties were estimated by the adsorption of appropriate probe molecules - NH 3 or SO 2 were used to estimate the population, strength and strength distribution of acid or basic sites, by means of adsorption microcalorimetry. The nature of acidic sites was determined through the adsorption/desorption of pyridine, studied by infrared spectroscopy. New phases between the oxides were not formed, while there is evidence of interaction between them, as revealed by XRD and Raman spectroscopy. All investigated mixed oxide samples are amphoteric and possess red-ox centers on their surface. Both red-ox and acid-base properties are dependent on the ratio of ceria to niobia in the samples. Both Lewis and Brönsted acid sites are present on the surface of the mixed oxides. In order to check catalytic abilities of these materials, reaction of fructose dehydration has been performed. All the investigated materials are catalytically active in fructose dehydration; conversion of fructose and selectivity to 5-hydroxymethylfurfural (5-HMF) improved with increasing content of niobia in the samples. © 2011 Elsevier B.V.

Bondzulic B.P.,University of Belgrade | Petrovic V.S.,University of Manchester
Signal Processing | Year: 2014

Objective quality metrics predict perceived quality of image signals computationally and can: (i) benchmark and monitor compression and processing algorithms and (ii) optimise their performance for a given application (content, bandwidth, packet loss.). Structural similarity, represented by the well known SSIM index is a framework for objective assessment of image quality well known for its relative simplicity and robustness. Despite its practical appeal, SSIM's performance level, measured as agreement with subjective quality scores, lags more complex state-of-the-art metrics. We present a new look into structural similarity that uses an additive model and a spatial pooling approach that decouples individual structural comparisons and utilises the quality driven aggregation paradigm. We apply this new approach to both baseline intensity SSIM and gradient SSIM (GSSIM) frameworks and show, through extensive evaluation on four publicly available subjective datasets that it provides considerably more ordered (linear) relationship between objective and subjective quality for a variety of input conditions. We demonstrate that newly formulated structural similarity metrics using this approach are capable of equal or even better performance than more complex state-of-the-art objective metrics in the process lending support to the theory that humans base their opinion on the worst sections of the observed signal. © 2013 Elsevier B.V.

Pyrolysis process of coffee paper cup samples was investigated in a flow stream of nitrogen at different heating rates (10, 20, 30 and 40 °C min -1), using thermo-analytical techniques. It was found that second pyrolysis stage can be described by Šesták-Berggren (SB) autocatalytic model, with mechanism function f(α) = α 0.011(1 - α)1.459. Based on analysis of SB kinetic exponents (designated by M and N), it was found that second pyrolysis stage is mainly controlled by chemical process, involving reactions with reaction-order (n) higher than unity. Applying specific statistical analysis, in order to obtain precise distribution of reactivity, the discrete (binomial) distribution has shown that there are two important areas of current distribution for corresponding energy outcomes, within the apparent activation energy as random variable. The first "concentration" area of energy outcomes corresponds to start of chain end depolymerization reaction forming levoglucosan at high enough temperature region, while second "concentration" area of energy outcomes includes occurrence of macro-radicals in liquid phase propagate with radical addition on unsaturated C-C bonds, with cross-linking and formation of small chemical species. It was found that further elevating of temperature (above 340 °C), will leads to fact that rate of tar-forming reactions increases and formation of char decreases. © 2014 Elsevier Ltd. All rights reserved.

In pathophysiological conditions related to oxidative stress, the application of selected antioxidants could have beneficial effects on human health. Electron paramagnetic resonance (EPR) spectroscopy is a technique that provides unique insight into the redox biochemistry, due to its ability to: (i) distinguish and quantify different reactive species, such as hydroxyl radical, superoxide, carbon centered radicals, hydrogen atom, nitric oxide, ascorbyl radical, melanin, and others; (ii) evaluate the antioxidative capacity of various compounds, extracts and foods; (iii) provide information on other important parameters of biological systems. A combination of EPR spectroscopy and traditional biochemical methods represents an efficient tool in the studies of disease mechanisms and antioxidative therapy prospects, providing a more complete view into the redox processes in the human organism.

Matausek M.R.,University of Belgrade | Ribic A.I.,Institute Mihajlo Pupin
Journal of Process Control | Year: 2012

The Modified Smith Predictor (MSP) is designed, and in the literature classified, as a Dead-Time Compensator for integrating processes. In the present paper it is shown that the MSP is a PID controller in series with a second-order filter, defined by the dead-time and an adjustable parameter. Optimization of the regulatory performance of this controller is performed under constraints on the robustness and sensitivity to measurement noise. Excellent performance/robustness tradeoff is obtained for stable, integrating and unstable processes, including dead-time, as confirmed by simulations and by experimental result obtained on a laboratory thermal process. © 2011 Elsevier Ltd. All Rights Reserved.

Baranac-Stojanovic M.,University of Belgrade
RSC Advances | Year: 2014

Nuclear magnetic resonance (NMR) spectroscopy is an important technique for structure determination. Within it, anisotropic effects of different functional groups and ring systems, depicted as familiar "anisotropy cones", are broadly used to deduce the stereochemistry, for chemical shift assignments and to explain shielding or deshielding of nuclei spatially close, or directly attached to the corresponding functional group, or ring. Progress in computational methods has enabled the quantification of anisotropic effects, an insight into their origin and to the source of (de)shielding of proximal nucleus. Some widely accepted traditional explanations, presented in NMR spectroscopy textbooks, have been questioned. The purpose of this review is to collect and discuss the research, mainly based on theoretical calculations, that provided new insight into the anisotropic effects, their origin and factors responsible for (de)shielding of proximal protons. © 2014 The Royal Society of Chemistry.

Dragovic G.,University of Belgrade
Asian Pacific Journal of Tropical Biomedicine | Year: 2013

Pancreatitis is a well-described complication of human immunodeficiency virus (HIV) itself and its combination antiretroviral therapy. Historically, this has been predominantly associated with the usage of nucleoside reverse transcriptase inhibitors such as didanosine and stavudine, but only rarely with the usage of protease inhibitors via the induction of hypertriglyceridemia. Pancreatitis rates in HIV/AIDS population may have been exceedingly high because of the comorbid conditions prevalent in HIV/AIDS patients (e.g. ethanol use and biliary disease), and the use of non-combination antiretroviral therapy medications such as pentamidine, corticosteroids, ketoconazole, sulphonamides, metronidazole, isoniazid and opportunistic infections (e.g. cytomegalovirus, cryptosporidiosis, mycobacterial disease). In resource limited settings, where didanosine and stavudine are widely available in cheaper generic fixed dose combinations it is likely that their usage will remain in the first line HIV treatment in common. In such settings management or estimation of a patient's risk of pancreatitis still remains an issue of concern. © 2013 Asian Pacific Tropical Biomedical Magazine.

Sestak J.,University of West Bohemia | Holba P.,University of West Bohemia | Zivkovic Z.,University of Belgrade
Journal of Mining and Metallurgy, Section B: Metallurgy | Year: 2014

The famous Kissinger's kinetic evaluation method (Anal. Chem. 1957) is examined with respect to the feasible impact of the individual quantities and assumptions involved, namely the model of reaction mechanism, f(α) (with the iso-and nonisothermal degrees of conversion, λ and l) the rate constant, k(T) (and associated activation energy, E), heating/cooling rate, β (supplementing additional thermodynamic term for the melt undercooling, δT) and above all, the association of the characteristic temperature, Tm , with the DTA peak apex. It is shown that the Kissingeŕs equation, in contrary to the results of Vold (Anal. Chem. 1949), is omitting the term of heat inertia arising from the true balance of heat fluxes. The absence of this term skews the evaluated values of activation energies.

Mijailovic R.,University of Belgrade
Transport | Year: 2011

The paper deals with the problem of a dynamic analysis of truck-cranes. Therefore, the article has developed a mechanical-mathematical model having 18 generalized coordinates. Depending on the type of truck crane operation as well as on the fact whether the aim of the article is to conduct the dynamic analysis of the whole truck crane or only that of one of its components, simpler mechanical models are also offered. The presented model is more realistic than those describing the dynamic behaviour of the truck-crane performing all necessary functions, i.e. a mobile means of lifting, transportation and reloading. © 2011 Copyright Vilnius Gediminas Technical University (VGTU) Press Technika.

Stojkovic-Filipovic J.,University of Belgrade
Applied Immunohistochemistry and Molecular Morphology | Year: 2016

Minichromosome maintenance (MCM) proteins are a group of proteins involved in DNA replication and cell-cycle regulation. Because they are associated with DNA through G1 into S phase, MCM proteins are potentially specific indicators of cell proliferation that could be valuable markers of dysplasia, and preinvasive and invasive malignant tumors. To analyze MCM protein expression patterns in actinic keratosis (AK), Bowen disease (BD), and cutaneous squamous cell carcinoma (SCC), we performed immunohistochemical staining of MCM2, -5, and -7 on tissue microarray blocks from 91 AK, 50 BD, and 174 SCC samples. The distribution and semiquantitatively assessed number of positive cells were analyzed in relation to the type of the lesion and the SCC prognostic parameters (grade, diameter, and thickness). Basal expression of all 3 proteins was observed more frequently in AK, whereas the distribution in BD was predominantly diffuse (P<0.001). All 3 proteins showed peripheral distribution in most well-differentiated SCC and diffuse distribution in poorly differentiated tumors (P<0.001). Using the 50% cut-off value, there was a statistically significant difference among AK, BD, and SCC (P<0.001). In addition, all MCM proteins showed highly significant differences (P<0.001) between well-differentiated SCC and both moderately and poorly differentiated SCC. The diffuse distribution and 50% cut-off value of positive cells revealed statistically significant associations of all MCM proteins with SCC thicker than 6 mm. Our results suggest a role for MCM proteins in the progression of in situ keratinocytic lesions and their association with high-risk features in SCC. Copyright 2016 Wolters Kluwer Health, Inc. All rights reserved.

Jovanovic M.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2012

The study describes ocular injuries caused by airsoft guns pellets, type of these injuries and their incidence in different age groups. This is a retrospective review of medical charts of patients who were hospitalized due to airsoft guns ocular injuries in ten-year period (from 2000 to 2009). Patient's age, gender, duration of hospitalization, type of treatment and initial and final visual acuity were analyzed. Overall 92 patients with ocular injuries caused by airsoft gun pellets were hospitalized in ten-year period. In all patients only one eye was injured and there were 72 (78.3%) male patients. Injuries involved ocular adnexa, anterior and posterior segment of the eye. On initial examination 41 (44.6%) patients were presented with subconjunctival hemorrhages, 42 (45.6%) with corneal abrasion, 42 (45.6%) patients had corneal edema, 6 (6.5%) had traumatic mydriasis, 90 (97.8%) patients exhibited hyphema, 10 (10.9%) iridodialysis, in 27 (29.3%) patients high intraocular pressure (IOP) was measured, one patient had subluxation of intraocular lens (IOL) and one patient had traumatic cataract. Posterior segment findings included vitreous hemorrhage in 3 (3.3%) patients, retinal hemorrhage in 15 (16.3%) patients, retinal edema in 35 (38.0%) patients and one patient had globe rupture. Average duration of hospitalization was 5.7 days (range from 1 to 18 days). Three patients (3.3%) required eye surgery, eight patients (8.7%) had anterior chamber washout while rest of the patients were conservatively managed. Visual acuity at hospital release was significantly improved comparing to initial visual acuity, ranging from counting fingers at 1 meter to 20/60 in 7 (8.6%) patients, from 20/50 to 20/30 in 13 (16.0%) patients and from 20/25 to 20/20 in 61 (75.3%) patients. In 11 patients testing the visual acuity was not possible because of their young age. Injuries attributed to airsoft guns were confined mostly to anterior segment. There was also high percentage of severe posterior segment trauma requiring hospital admission. The most important factors in preventing such injuries are restricting access to airsoft guns, especially to minors, as well as mandatory use of protective equipment such as protective eyeglasses.

Devedzic V.,University of Belgrade | Milenkovic S.R.,Megatrend University
IEEE Transactions on Education | Year: 2011

This paper describes the authors' experience of teaching agile software development to students of computer science, software engineering, and other related disciplines, and comments on the implications of this and the lessons learned. It is based on the authors' eight years of experience in teaching agile software methodologies to various groups of students at different universities, in different cultural settings, and in a number of courses and seminars. It specifically discusses three different courses on agile software development, given in different teaching settings and at different levels, and briefly surveys variations to these courses given elsewhere. Based on the experience acquired, analyses and evaluations conducted, and current pedagogical trends at relevant university departments, the authors provide recommendations on how to overcome potential problems in teaching agile software development and make their adoption more effective. © 2011 IEEE.

Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2015

In order to establish associations of trace and major elements in dump coal ash taken from active, currently filled cassette of "Nikola Tesla A" power plant dump (Obrenovac near Belgrade, Serbia), eight samples of dump ash were subjected to a five-step sequential extraction, comprising of the following phases: distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, acidic solution of H2O2, and 6 M solution of HCl. The obtained concentrations were subjected to correlation analysis, and results compared to those obtained by analysis of leached concentrations from fresh, lignite filter coal ash. © Taylor and Francis Group, LLC.

Petrovic J.,University of Belgrade | Petrovic J.,University of Novi Sad | Serpico P.D.,University of Savoy | Zaharijas G.,University of Nova Gorica | And 2 more authors.
Journal of Cosmology and Astroparticle Physics | Year: 2015

Several groups of authors have analyzed Fermi LAT data in a region around the Galactic Center finding an unaccounted gamma-ray excess over diffuse backgrounds in the GeV energy range. It has been argued that it is difficult or even impossible to explain this diffuse emission by the leading astrophysical candidates - millisecond pulsars (MSPs). Here we provide a new estimate of the contribution to the excess by a population of yet unresolved MSP located in the bulge of the Milky Way. We simulate this population with the GALPLOT package by adopting a parametric approach, with the range of free parameters gauged on the MSP characteristics reported by the second pulsar catalogue (2PC). We find that the conclusions strongly depend on the details of the MSP luminosity function (in particular, its high luminosity end) and other explicit or tacit assumptions on the MSP statistical properties, which we discuss. Notably, for the first time we study the importance of the possible secondary emission of the MSPs in the Galactic Center, i.e. the emission via inverse Compton losses of electrons injected in the interstellar medium. Differently from a majority of other authors, we find that within current uncertainties a large if not dominant contribution of MSPs to the excess cannot be excluded. We also show that the sensitivities of future instruments or possibly already of the latest LAT data analysis (Pass 8) provide good perspectives to test this scenario by resolving a significant number of MSPs. © 2015 IOP Publishing Ltd and Sissa Medialab srl .

Simeunovic S.,University of Belgrade
Srpski arhiv za celokupno lekarstvo | Year: 2011

Athersclerosis is a multifactorial disease that begins in childhood. There are few reports regarding influence of risk factors on the atherosclerotic processes in early period of life and adolescence. The aim of this study was to present and analyze risk factor trends in school children over a 10-year period that were included and followed-up by the Yugoslav Study of Atherosclerosis Precursors in School Children (YUSAD Study). There were three examinations of selected population from 13 centres. The first examination was performed when children were 10 years of age (first group; N = 6381 participants), the second examination on the same population when they were 15 years of age (second group; N = 5017) and third when children were 19/20 years of age (third group; N = 1293). Evaluated parameters included: BMI, waist circumference (WaC) and lipid profile (total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride). A significant elevation of values (p < 0.001) of BMI, WaC and triglycerides and a significant decline (p < 0.001) of total cholesterol and LDL cholesterol in boys over 5 and 10-year period was noticed. There was a significant elevation (p < 0.001) of BMI, WaC and HDL values and a significant decline in LDL cholesterol values in girls over the 5 and 10-year period. Our results point out that girls between 10 and 19/20 years have a better lipid profile during growth. It should be stressed out that childhood and adolescence can be more beneficial in the observation of risk factor influences on pathological, genetic and clinical levels.

Vasiljevic A.L.,University of Belgrade
Thermal Science | Year: 2015

The paper presents the analysis of possible potentials for the production of forest biomass in Serbia taking into consideration the condition of forests, present organizational and technical capacities as well as the needs and situation on the firewood market. Starting point for the estimation of production potentials for forest biomass is the condition of forests which is analyzed based on the available planning documents on all levels. Potentials for biomass production and use refer to initial periods in the production and use of forest biomass in Serbia.

The paper brings forth a detailed analysis of the solution of the problem of the material realization of a nonlinear nonholonomic constraint (NNC). The existing models of the NNC are shown that can be classified into two groups: the first group comprises correctly realized physical models, while the second group contains the so-called "quasinonlinear" nonholonomic constraints which in fact represent mathematical models. The correctness of the cited models is considered in detail, and the essential nature of such constraints, the basic of which is holonomic, is shown. The second group of models, i.e., the "quasinonlinear" NC (nonholonomic constraints) in fact represents the given program of motion, while the additional force, which carries out the program, has the analytical form of the reaction of the NNC. That is why are presented the models of the NNC which possess a clear physical sense, on the basis of which certain statements on the method of variation and the reaction of the NNC can be given. With regard to the clear physical sense and the nature of the models cited, the NNC that come out of them are used quite normally in the analysis of motion of such a system. The cited models, together with standard models oh nonholonomic Mechanics (sphere, disk, blade) make a group of basic nonholonomic constraints which can be classified, according to the three criteria, into certain types. Finally, it is shown that the cited model can be used for the construction of "nonholonomic chains", both open and closed ones. The paper brings forth a detailed analysis of the solution of the problem of the material realization of a nonlinear nonholonomic constraint (NNC). The existing models of the NNC are shown that can be classified into two groups. With regard to the clear physical sense and the nature of the models citied, the NNC that come out of them are used quite normally in the analysis of motion of such a system. The cited models, together with standard models oh nonholonomic Mechanics (sphere, disk, blade) make a group of basic nonholonomic constraints which can be classified, according to the three criteria, into certain types. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zekovic D.N.,University of Belgrade
ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik | Year: 2011

Depending on how the nonholonomic constraints have been introduced to the Lagrange-D'Alemberts's principle, there are several differential equations of motion in the mechanics of nonholonomic systems. In this work, the most general type of differential equations of motion (fundamental to all known forms of the equations of motion for nonholonomic as well as holonomic systems) is derived. Here, the equations represent the generalization of Poincare's equation [1]. In published works [2, 3, 4, 5, 6], these have already taken into account nonlinear nonholonomic constraints and linear relations between real velocities and kinematic parameters. A method of dedication of the most generalized form of the equations of motion will be shown. It is followed by the analysis of particular cases. Then, it will be shown how to get form the generalized form to Maggi, Appell, Voronec, Chaplygin, Volterra, Ferrers, and Boltzmann-Hamel's equations appearing in nonholonomic systems. Further, a system of material points of variable mass, where the equations of motion are derived for the most general case of reactive forces and in case of constraints depending on mass variables will be considered. All theoretical considerations are illustrated with the analysis of the relevant nonholonomic model. Depending on how the nonholonomic constraints have been introduced to the Lagrange-D'Alemberts's principle, there are several differential equations of motion in the mechanics of nonholonomic systems. In this work, the most general type of differential equations of motion (fundamental to all known forms of the equations of motion for nonholonomic as well as holonomic systems) is derived. Here, the equations represent the generalization of Poincaré's equation. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vukosavic S.N.,University of Belgrade
IET Electric Power Applications | Year: 2011

This study presents a novel algorithm for the induction motor torque control in field-weakening region. The proposed method insures maximum DC bus utilisation and extends the torque-speed curve up to the system limits. Controller is based on the stator voltage angle control. It provides full DC-link disturbance rejection and offers the torque response time sufficient for most applications. The algorithm is simple, without neither the outer flux loop nor the inner current loop. Dynamic response is preserved over wide speed range by means of gain-scheduling. Simulations and experiments prove an ease of implementation and the robustness of the proposed solution. This study comprises analytical considerations, simulation results, a detailed description of implementation steps and extensive experimental results. © The Institution of Engineering and Technology 2011.

Abstract Essential oil of Carum copticum seeds, obtained from a local shop, was extracted and content of thymol was analyzed using square-wave voltammetry at boron-doped diamond electrode. The effect of various parameters, such as pH of supporting electrolyte and square-wave voltammetric parameters (modulation amplitude and frequency), was examined. In Britton-Robinson buffer solution (pH 4), thymol provided a single and oval-shaped irreversible oxidation peak at +1.13 V versus silver/silver chloride potassium electrode (3 M). Under optimal experimental conditions, a plot of peak height against concentration of thymol was found to be linear over the range of 4 to 100 μM consisting of two linear ranges: from 4 to 20 μM (R2 = 0.9964) and from 20 to 100 μM (R2 = 0.9993). The effect of potential interferences such as p-cymene and γ-terpinene (major components in essential oil of C. copticum seeds) was evaluated. Thus, the proposed method displays a sufficient selectivity toward thymol with a detection limit of 3.9 μM, and it was successfully applied for the determination of thymol in essential oil of C. copticum seeds. The Prussian blue method was used for validation of the proposed electroanalytical method. © 2015 Elsevier Inc.

Brajevic I.,University of Belgrade
Proceedings of the European Computing Conference, ECC '11 | Year: 2011

This paper presents an artificial bee colony (ABC) algorithm adjusted for the capacitated vehicle routing problem. The vehicle routing problem is an NP-hard problem and capacitated vehicle routing problem variant (CVRP) is considered here. The artificial bee metaheuristic was successfully used mostly on continuous unconstrained and constrained problems. Here this algorithm has been implemented for rather different type of problems and tested on twelve benchmark instances of small scale problems. Our results were compared to the best known results. The computational study showed that the proposed algorithm is a good and promising approach for capacitated vehicle routing problem.

Kostic V.S.,University of Belgrade | Filippi M.,University of Milan
Journal of the Neurological Sciences | Year: 2011

Depression and apathy are among the most common neuropsychiatric disturbances in Parkinson's disease (PD), and among the most important factors associated with a poor quality of life. However, their neural bases remain unclear. The results of the magnetic resonance imaging (MRI) studies on depression in PD differ dramatically. Some of them proposed a role of morphologic changes in the mediodorsal thalamus. In contrast to previous voxel-based morphometry (VBM) data, our study did not confirm a decrease in gray matter (GM) density in any brain region of depressed PD patients. Instead, a more severe white matter (WM) loss in the right frontal lobe was found, including the anterior cingulate bundle and the inferior orbitofrontal (OF) region. We suggested that the negative correlation between the severity of depression and WM density in the right OF region reinforces the hypothesis of depression in PD as a "disconnection syndrome". Only one MRI study using VBM found that high apathy scores correlated with low GM density values in the right (posterior) cingulate gyrus and the bilateral inferior frontal gyrus, in line with the findings in Alzheimer's disease and elderly adults with major depression. © 2011 Elsevier B.V.

The non-isothermal pyrolysis kinetics of Acetocell (the organosolv) and Lignoboost® (kraft) lignins, in an inert atmosphere, have been studied by thermogravimetric analysis. Using isoconversional analysis, it was concluded that the apparent activation energy for all lignins strongly depends on conversion, showing that the pyrolysis of lignins is not a single chemical process. It was identified that the pyrolysis process of Acetocell and Lignoboost® lignin takes place over three reaction steps, which was confirmed by appearance of the corresponding isokinetic relationships (IKR). It was found that major pyrolysis stage of both lignins is characterized by stilbene pyrolysis reactions, which were subsequently followed by decomposition reactions of products derived from the stilbene pyrolytic process. It was concluded that non-isothermal pyrolysis of Acetocell and Lignoboost® lignins can be best described by n-th (n>1) reaction order , using the Weibull mixture model (as distributed reactivity model) with altekineticsrnating shape parameters. © 2011 Elsevier Ltd.

Lazarevic I.,University of Belgrade
World Journal of Gastroenterology | Year: 2014

Hepatitis B virus (HBV) infection is a major cause of acute and chronic hepatitis, and of its long-term complications. It is the most variable among DNA viruses, mostly because of its unique life cycle which includes the activity of error-prone enzyme, reverse transcriptase, and the very high virion production per day. In last two decades, numerous research studies have shown that the speed of disease progression, reliability of diagnostic methods and the success of antiviral therapy and immunization are all influenced by genetic variability of this virus. It was shown that mutations in specific regions of HBV genome could be responsible for unwanted clinical outcomes or evasion of detection by diagnostic tools, thus making the monitoring for these mutations a necessity in proper evaluation of patients. The success of the vaccination programs has now been challenged by the discovery of mutant viruses showing amino acid substitutions in hepatitis B surface antigen (HBsAg), which may lead to evasion of vaccine-induced immunity. However, the emergence of these mutations has not yet raised concern since it was shown that they develop slowly. Investigations of HBV genetic variability and clinical implications of specific mutations have resulted in significant advances over the past decade, particularly in regard to management of resistance to antiviral drugs. In the era of drugs with high genetic barrier for resistance, on-going monitoring for possible resistance is still essential since prolonged therapy is often necessary. Understanding the frequencies and clinical implications of viral mutations may contribute to improvement of diagnostic procedures, more proper planning of immunization programs and creating the most efficient therapeutic protocols. © 2014 Baishideng Publishing Group Inc. All rights reserved.

Kim J.T.,Kyung Hee University | Todorovic M.S.,Kyung Hee University | Todorovic M.S.,University of Belgrade
Energy and Buildings | Year: 2013

Further advance of glazed, healthy building's energy efficiency and sustainability is inextricable linked to the building's envelopes/facades fundamental physics study related to the dynamic control of sunlight and optimal control of solar heat gains. Relevant mathematical models and algorithms, as well as infrastructure/hardware and software integrated performance prediction and validation are studied. Reviewed is the most recent analytical and experimental research, current state of science and art, as well as some of the on-going R&D at the edge of new breakthroughs of the healthy buildings daylighting dynamic control's performance prediction and validation. It has been shown that, concerning the variability of the solar radiation spectra incident on the building's envelope, and also variability of outdoor and indoor air temperature differences, it is necessary tuning control of glazing's transmittance dependence on the solar radiation wavelength, with an aim to optimize daylighting with the reference to people needs (their health and comfort), and energy (thermal and electrical loads minimization). Finally, presented are elements of an analytical modeling approach, as initial results of study, aimed to reach a challenging research goal - Tuning control of buildings Glazing's transmittance dependence on the solar radiation wavelength to optimize daylighting and building's energy efficiency. © 2013 Elsevier B.V. All rights reserved.

Kim J.T.,Kyung Hee University | Todorovic M.S.,Kyung Hee University | Todorovic M.S.,University of Belgrade
Energy and Buildings | Year: 2013

As, fossil energy resources are closer to their exhaustion, global warming in raise, and more catastrophic weather extremes are occurring worldwide, there are more and more warnings that the risks to the Earth humanity survival are also in growth. The Earth/humanity as a whole is becoming more complex system than ever. Trying to find a way to make a turn from the current one-way irreversibility to sustainability, it is necessary to find universal schemes, quantities, indicators and criteria relevant for the Earth and humanity's resilience and sustainability. Presented is a review of the multi-criteria sustainability analysis methods (intrinsic thermodynamic based on energy, exergy, sustainability index, analytic hierarchy process, etc.). It has been shown that crucial sensitivity of all methods is related to the selected sets of energy criteria (economical, social and environmental) and to the mathematical algorithms for the determination of the weighted factor and sub-indicators agglomeration. Also, shown is that concerning buildings sustainability is missing indicator relevant to the indoor comfort and people health, accompanied with a comprehensive, physically sound assessment methodology for building's synergetic environmental performance - twofold metrics with the reference to outdoor and indoor built environment concerning people health and comfort. A scheme of a structure and spatio-temporal vision of the Global sustainable development is presented - showing that the approach to the global sustainable development can be reliable only if it is based on a system of real human and ethical values applicable to every social, cultural and economic situation. Finally paper summarizes needs for future multidisciplinary, inter- and cross-disciplinary study on healthy sustainable buildings, interwoven with harmony and holistic people health and well-being research. That research is to be physically sound - intrinsic thermodynamic, harmonious green, and relevant metrics is to be free of the short-term politically shaped and quasi-economically distorted approaches, because the world is to get what is painfully missing - a standard metrics of the sustainability index, universally acceptable. © 2013 Elsevier B.V. All rights reserved.

Zhuang Z.,U.S. National Institutes of Health | Yang C.,U.S. National Institutes of Health | Lorenzo F.,University of Utah | Merino M.,U.S. National Institutes of Health | And 6 more authors.
New England Journal of Medicine | Year: 2012

Hypoxia-inducible factors are transcription factors controlling energy, iron metabolism, erythropoiesis, and development. When these proteins are dysregulated, they contribute to tumorigenesis and cancer progression. However, mutations in genes encoding α subunits of hypoxia-inducible factors (HIF-α) have not previously been identified in any cancer. Here we report two novel somatic gain-of-function mutations in the gene encoding hypoxia-inducible factor 2α (HIF2A) in two patients, one presenting with paraganglioma and the other with paraganglioma and somatostatinoma, both of whom had polycythemia. The two mutations were associated with increased HIF-2α activity and increased protein half-life. Copyright © 2012 Massachusetts Medical Society.

Balaz A.,University of Belgrade | Paun R.,Horia Hulubei National Institute of Physics and Nuclear Engineering | Nicolin A.I.,Horia Hulubei National Institute of Physics and Nuclear Engineering | Balasubramanian S.,Center for Nonlinear Science | Ramaswamy R.,Center for Nonlinear Science
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We study the emergence of Faraday waves in cigar-shaped collisionally inhomogeneous Bose-Einstein condensates subject to periodic modulation of the radial confinement. Considering a Gaussian-shaped radially inhomogeneous scattering length, we show through extensive numerical simulations and detailed variational treatment that the spatial period of the emerging Faraday waves increases as the inhomogeneity of the scattering length gets weaker, and that it saturates once the width of the radial inhomogeneity reaches the radial width of the condensate. In the regime of strongly inhomogeneous scattering lengths, the radial profile of the condensate is akin to that of a hollow cylinder, while in the weakly inhomogeneous case the condensate is cigar shaped and has a Thomas-Fermi radial density profile. Finally, we show that when the frequency of the modulation is close to the radial frequency of the trap, the condensate exhibits resonant waves which are accompanied by a clear excitation of collective modes, while for frequencies close to twice that of the radial frequency of the trap, the observed Faraday waves set in forcefully and quickly destabilize condensates with weakly inhomogeneous two-body interactions. © 2014 American Physical Society.

Prvanovic S.,University of Belgrade
Progress of Theoretical Physics | Year: 2011

The self-adjoint operator of time in nonrelativistic quantum mechanics is found within the approach where the ordinary Hamiltonian is not taken to be conjugate to time. Quantization of the re-expressed Liouville equation with the total Hamiltonian, consisting of the part that is a conventional function of coordinate and momentum and the part that is conjugate to time, is considered. The von Neumann equation with quantized time is found and discussed from the point of view of exact time measurement.

Netjasov F.,University of Belgrade
Transportation Research Part C: Emerging Technologies | Year: 2012

This paper presents a framework for airspace planning and design based on a conflict risk assessment developed for the purpose of preventing aircraft conflicts and collisions. The paper also presents a conflict risk assessment model developed for airspace strategic planning, as a first step of the proposed framework. The model is intended to facilitate comparisons and sensitivity analyses of different airspace designs and organizational scenarios under different traffic flow levels. Risk is assessed using two variables: the conflict probability and the number of conflicts in the observed airspace under the given circumstances. The model is based on the concept of critical sections, which are traversed by the aircraft during level flight, or while climbing or descending through these sections. For a given pair of aircraft conflict probability is defined as product of the probability that one aircraft is in a critical section of its own trajectory, and the conditional probability that another aircraft is in its own critical section while the first aircraft is already in it. The number of conflicts is defined as the product of conflict probability and estimated traffic flows for the given airway. The final values for conflict numbers are determined taking into account all available flight levels and airway combinations in the given airspace. The model provides an analysis of influence of separation reduction on conflict risk and could be used in both en-route and terminal manoeuvring airspace. © 2012 Elsevier Ltd.

Netjasov F.,University of Belgrade
Transportation Research Part C: Emerging Technologies | Year: 2012

This paper presents a conflict risk assessment model developed for the purpose of airspace tactical planning under the framework for airspace planning and design based on conflict risk assessment. The model is intended for comparison of different alternative flight scheduling scenarios for a given airspace sectorisation, from a risk and safety point of view. Conflict risk is assessed using duration and severity of conflict situation in the observed airspace under given circumstances. The model is based on the assumption that conflict between pair of aircraft exists when either horizontal or vertical separation minima are violated. For the purpose of risk assessment at the tactical planning level, a term "elementary risk" is introduced. It is defined as the ratio between: (1) the surface limited by minimum separation line and function representing the change of aircraft separation and the surface limited by minimum separation and time moments presenting the conflict duration, and (2) abscissa. The risk is then defined as the ratio between the "elementary risk" and the observed period of time. Apart from the risk between aircraft pair, an assessment of the total risk is also considered. A simple illustration of the model application shows that in addition to airspace geometry, the conflict risk between aircraft pair and total conflict risk also depends on traffic demand, aircraft speed, spatial and temporal distribution of traffic in the airspace as well as the applied separation minima. The developed model is intended for use both in en-route as well as terminal airspace and allows for the determination of the most suitable flight schedule which would be balanced with risk and capacity requirements (lower risk, greater capacity). © 2012 Elsevier Ltd.

Jovanovic R.,Qatar Environment and Energy Research Institute | Jovanovic R.,University of Belgrade | Voss S.,University of Hamburg
Computers and Industrial Engineering | Year: 2014

In the Blocks Relocation Problem (BRP) one is given a block retrieval sequence and is concerned with determining a relocation pattern minimizing the total number of moves required to enforce the given retrieval sequence. The importance of the BRP has been constantly growing in recent years, as a consequence of its close connection with the operations inside of a container terminal. Due to the complexity of the BRP, a large number of methods has been developed for finding near optimal solutions. These methods can be divided in two main categories greedy heuristics and more complex methods. The latter achieve results of higher quality, but at the cost of very long execution times. In many cases, this increased calculation time is not an option, and the fast heuristic methods need to be used. Greedy heuristic approaches, in general, apply the heuristic based only on the properties of the block that is being relocated and the current state of the bay. In this paper we propose a new heuristic approach in which when deciding where to relocate a block we also take into account the properties of the block that will be moved next. This idea is illustrated by improving the Min-Max heuristic for the BRP. We compare the new heuristic to several existing methods of this type, and show the effectiveness of our improvements. The tests have been conducted on a wide range of sizes of container bays, using standard test data sets. © 2014 Elsevier Ltd. All rights reserved.

Popa A.,Institute of Chemistry Timioara | Sasca V.,Institute of Chemistry Timioara | Holclajtner-Antunovic I.,University of Belgrade
Microporous and Mesoporous Materials | Year: 2012

The Cs salt of molybdophosphoric acid Cs 2.5H 0.5PMo 12O 40 (CsHPM) was supported on SBA-15 in the concentration of 20, 30 and 40 wt.% loadings. Because Cs acid salts are insoluble, the SBA-15 supported Cs-acid salts were prepared by two-step sequential impregnation and in situ reaction on the support. The structure and texture of these CsHPM/SBA-15 composites were studied by XRD, SEM-EDS, FT-IR and micro-Raman spectroscopy and N 2 adsorption. Thermal stability was investigated by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). The dehydration of ethanol was used to probe the catalytic properties of the CsHPM samples incorporated on the silica matrix. FT-IR and Raman studies demonstrated that CsHPM maintained its Keggin structure after deposition on mesoporous SBA-15, regardless of the active phase concentration. The values of specific surface area of pure CsHPM were increased by deposition on mesoporous silica support. The immobilization of CsHPM on mesoporous SBA-15 obviously increases the thermal stability of the Keggin structures in comparison with their parent bulk Cs salts. The main reaction products obtained on acid (dehydration) catalytic centres were ethylene and diethyl ether, and respectively acetaldehyde which was obtained on redox (dehydrogenation) catalytic centres. © 2012 Elsevier Inc. All rights reserved.

Zikic D.,University of Belgrade
European Biophysics Journal | Year: 2016

The differences in the pressure and flow waveforms in the aortic root have not been explained so far in a satisfactory mathematical way. It is a generally accepted idea that the existence of the reflected wave causes the differences in shapes of pressure and flow. In this paper, a mathematical model is proposed that explains the blood pressure and flow waveforms based on changes in left ventricular volume during blood ejection into the aorta. According to the model, a change in volume of the left ventricle during contraction can be mathematically presented with solutions of differential equations that describe the behavior of a second-order system. The proposed mathematical equations of pressure and flow waveforms are derived from left ventricular volume change and basic equations of fluid dynamics. The position of the reflected wave depends on the age and elasticity of arteries, and has an effect on the flow and pressure waveforms. The model is in acceptable agreement with the experimental data available. © 2016 European Biophysical Societies' Association

Milovic L.,University of Belgrade
Materials at High Temperatures | Year: 2010

The microstructural changes in the heat affected zone (HAZ) of 9% chromium ferritic steel for manufacturing fossil fired power plant components are investigated. The heat treatment region of 925°C in HAZ was tested as a potential location of Type IV cracks which occur during operation. For comparison of characteristics and material behaviour, the microstructural investigation of simulated specimens of HAZ was carried out at room temperature, i.e. 20°C and at an operating temperature of 600°C, using two Types of specimens: with postweld heat treatment (PWHT) and without PWHT. The test results revealed the presence of precipitates at the grain boundaries in specimens simulated at 925°C with subsequent PWHT. These results confirmed that PWHT is necessary for P91 steel to be integrated into components in service under creep condition. © 2010 Science Reviews 2000 Ltd.

Nikolic N.D.,University of Belgrade | Brankovic G.,Serbian Institute for Multidisciplinary Research
Materials Letters | Year: 2012

Formation of open porous copper structures by the electrodeposition processes in the hydrogen co-deposition range was considered. Morphologies of copper deposits obtained by the reversing current (RC) regimes at the same average current density but with the different the anodic current density/anodic pulse ratios were compared with those obtained by the pulsating current (PC) regime at the same average current density and in the constant galvanostatic mode at the current density which was equal to this average current density. The considerable increase of the specific surface area of the honeycomb-like structures, determined by the increase of number of holes, as well as by the decrease of both holes size and wall width among them, can be attained if the appropriate parameters of the RC regimes are applied. In this way, it is shown that the regime of reversing current (RC) is superior in the production of open porous structures suitable to be used as electrodes in many electrochemical devices in relation to other current regimes of electrolysis, such as the PC and the galvanostatic regimes. © 2011 Elsevier B.V. All rights reserved.

Pantic I.,University of Belgrade
Journal of Biosciences | Year: 2011

Although questioned on several occasions, the existence of cancer stem cells (CSCs) has been confirmed by a number of studies on experimental animal models. Nevertheless, it was shown that CSC hypotheses have several limitations and inconsistencies regarding the explanation of CSC origin, CSC identification and isolation, possible heterogeneity within CSC population, as well as methodology issues in some studies that were carried out in order to prove CSC existence. The aim of this article is to give a short and comprehensive review of recent advances concerning CSC hypothesis and to describe its impact on modern molecular physiology and pharmacology research. © Indian Academy of Sciences.

Nikolic D.M.,University of Belgrade
British Journal of Biomedical Science | Year: 2011

This study aims to determine the origin of bacterial contamination of pancreatic tissue cultures, as well as its influence on insulin secretory activity (expressed as stimulation index [SI]) of the pancreatic islets. Pancreatic tissue was obtained after pancreatectomy in patients who had chronic pancreatitis or benign tumours. Islets were isolated under aseptic conditions by a manual method. Microbiological analyses were performed by standard procedures and the SI was determined on the first and seventh day of cultivation. In cultures contamminated by Pseudomonas, SI was 1.58±1.16 on day 1 and 0.22±0.14 on day 7 (P<0.01). Cultures contaminated by Enterobacter showed an SI of 0.21±0.1 on day 1, which increased to 1.19±0.66 on day 7 (P<0.01). In cases of Staphylococcus contamination, SI was 0.07±0.05 on day 1 and 0.33±0.21 on day 7 (P<0.01). The study shows that cell culture contamination originates from an original pancreatic tissue infection. The presence of bacteria may reduce or increase insulin secretion in cell culture, depending on the type of microorganism, and this can provoke reduced or elevated levels of insulin secretion in recipients, thus increasing the chances for the onset of diabetes.

Kovacevic J.J.,University of Belgrade
Genomics, Proteomics and Bioinformatics | Year: 2012

A bioinformatics analysis of disorder content of proteins from the DisProt database has been performed with respect to position of disordered residues. Each protein chain was divided into three parts: N- and C- terminal parts with each containing 30 amino acid (AA) residues and the middle region containing the remaining AA residues. The results show that in terminal parts, the percentage of disordered AA residues is higher than that of all AA residues (17% of disordered AA residues and 11% of all). We analyzed the percentage of disorder for each of 20 AA residues in the three parts of proteins with respect to their hydropathy and molecular weight. For each AA, the percentage of disorder in the middle part is lower than that in terminal parts which is comparable at the two termini. A new scale of AAs has been introduced according to their disorder content in the middle part of proteins: CIFWMLYHRNVTAGQDSKEP. All big hydrophobic AAs are less frequently disordered, while almost all small hydrophilic AAs are more frequently disordered. The results obtained may be useful for construction and improving predictors for protein disorder. © 2012.

Banovic M.D.,University of Belgrade
Acta cardiologica | Year: 2011

Patients with moderate and severe aortic stenosis (AS) and without obstructive epicardial coronary disease have been shown to have an impairment of coronary flow velocity reserve (CFVR). Recently, it has been shown that CFVR is an independent predictor for future cardiovascular events in AS patients. We investigated parameters representing left ventricular (LV) mass and wall thickness, diastolic dysfunction, LV workload and haemodynamic indexes of AS severity to determine which contributes the most to impaired CFVR in patients with AS and a nonobstructed coronary angiogram. A total of 77 patients with moderate or severe AS, mean age 65.66 +/- 11.02 y (57.14% males), were enrolled in this prospective study. All patients had standard Doppler-echo study, coronary angiography and adenosine-stress transthoracic Doppler-echo for CFVR measurement. We took 2.5 as a cut-off value for impaired CFVR. Univariate analysis showed that aortic valve area (AVA), maximal velocity (Vmax), mean pressure gradient (Pmean), energy loss index (ELI), aortic valve resistance (AVR) and stroke work loss (SWL) were associated (P = 0.05) with impaired CFVR. Multivariate analysis showed that AVR was the best predictor of impaired CFVR (RR 0.900, Cl: 0.983-0.997, P = 0.007). Using ROC analysis, the AVR value of 211.22 dynes x s x cm(-5) had the highest accuracy in predicting the impaired CFVR (AUC-0.681, P=0.007, sensitivity 72%, specificity 52%, CI: 0.561-0.800). Haemodynamic indices of AS severity, together with LV workload parameters, are the main determinants of CFVR. Among all parameters, AVR is the strongest predictor of CFVR in patients with moderate or severe AS and a nonobstructed coronary angiogram.

Pekmezovic T.,University of Belgrade
Journal of Medical Biochemistry | Year: 2010

Classical epidemiology addresses the distribution and determinants of diseases in populations, and the factors associated with disease causation, with the aim of preventing disease. Both genetic and environmental factors may contribute to susceptibility, and it is still unclear how these factors interact in their influence on risk. Genetic epidemiology is the field which incorporates concepts and methods from different disciplines including epidemiology, genetics, biostatistics, clinical and molecular medicine, and their interaction is crucial to understanding the role of genetic and environmental factors in disease processes. The study of gene-environment interaction is central in the field of genetic epidemiology. Gene-environment interaction is defined as a different effect of an environmental exposure on disease risk in persons with different genotypes, or, alternatively, a different effect of a genotype on disease risk in persons with different environmental exposures. Five biologically plausible models are described for the relations between genotypes and environmental exposures, in terms of their effects on disease risk. Therefore, the study of gene-environment interaction is important for improving accuracy and precision in the assessment of both genetic and environmental factors, especially in disorders of less defined etiology. Genetic epidemiology is also applied at the various levels of disease prevention.

Novakovic B.,University of Belgrade
Monthly Notices of the Royal Astronomical Society | Year: 2010

The (778) Theobalda asteroid family has attracted little attention so far, but in our study we show that it is important in several ways. In this paper, we investigate the origin and evolution of the Theobalda family. First, we identify the family as a statistically relevant group in the space of synthetic proper elements. Using the hierarchical clustering method and the adopted cut-off velocity of dcut-off= 85 ms-1, we have found that the Theobalda family currently consists of 128 members. This family is located in the outer belt, near the proper semimajor axis ap≈ 3.175 au. This region is crossed by several three-body mean motion resonances, which give rise to significant chaotic zones. Consequently, the majority of family members reside on chaotic orbits. Using two independent methods, chaotic chronology and backward integration, we have found the Theobalda family to be only 6.9 ± 2.3 Myr old. We have also estimated that the family was likely produced by the cratering impact on a parent body of diameter DPB≈ 78 ± 9 km. © 2010 The Author. Journal compilation © 2010 RAS.

Clarner T.,RWTH Aachen | Parabucki A.,University of Belgrade | Beyer C.,RWTH Aachen | Kipp M.,RWTH Aachen
Journal of Neuroendocrinology | Year: 2011

Corticosteroids (CS) are effective in the treatment of many brain disorders, such as multiple sclerosis (MS) or traumatic brain injury. This has been scrutinised in different experimental animal models. However, neither the mechanisms, nor the site of CS action are fully understood. Short-term high-dose CS treatment improves MS symptoms and severity of clinical disability during an acute inflammatory exacerbation of disease. In the present study, we analysed the influence of CS on the expression of cellular and molecular markers of spontaneous endogenous remyelination in the toxic non-immune cuprizone animal model at early (9days) and intermediate (21days) remyelination, as well as steroidal effects in primary astrocytes and oligodendrocyte progenitor cultures. Dexamethasone (Dex) and methylprednisolone (MP) induced a higher expression of the differentiation markers myelin basic protein and proteolipid protein (PLP) in cultured oligodendrocyte progenitor cells (OPC). CS exposure of primary cultured astrocytes resulted in a greater expression of those genes involved in OPC proliferation [fibroblast growth factor 2 (FGF2) and platelet-derived growth factor (PDGF)-αα] and a reduced expression of the pro-maturation factor insulin-like growth factor 1. Pro-maturating effects of CS were completely blocked by FGF2 and PDGF-αα co-application in OPC cultures. MP treatment in vivo resulted in a reduced recovery of PLP-staining intensity, whereas the re-population of the demyelinated corpus callosum with adenomatous polyposis coli-expressing oligodendrocytes was not affected. The numbers of brain intrinsic inflammatory cells, microglia and astrocytes during remyelination were similar in placebo and MP-treated animals. Our findings suggest that treatment with CS might have, in addition to the well-known benefical effects on inflammatory processes, a negative influence on remyelination. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Sentic M.,CNRS Institute of Molecular Sciences | Loget G.,CNRS Institute of Molecular Sciences | Manojlovic D.,University of Belgrade | Kuhn A.,CNRS Institute of Molecular Sciences | Sojic N.,CNRS Institute of Molecular Sciences
Angewandte Chemie - International Edition | Year: 2012

Swimmer in the dark: Propulsion of a conducting object is intrinsically coupled with light emission using bipolar electrochemistry. Asymmetric redox activity on the surface of the swimmer (black bead; see picture) causes production of gas bubbles to propel the swimmer in a glass tube with simultaneous electrochemiluminescence (ECL) emission to monitor the progress of the swimmer. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mihailovic N.,University of Belgrade | Drazic G.,Faculty for Applied Ecology Futura
Plant, Soil and Environment | Year: 2011

The aim of the experiment was to test the capacity of NO to reverse harmfull effects of nickel on bean (Phaseolus vulgaris L.) seedlings. Bean seedlings were grown on culture medium and treated with NO-donor - sodium nitroprusside (0.3 mmol/L) and Ni (0.2 mmol/L NiCl 2). After 4 days, the parameters of antioxidative response were determined in roots and leaves, as well as the concentrations of essential cations and Ni. In the presence of Ni alone, soluble protein, proline and superoxide-dismutase activity were increased, while peroxidase and especially catalase activities were supressed. Also, Ni induced a depletion of K, Ca, Mg, Mn and Zn, while the contents of Cu and Fe in the roots were increased. In the presence of NO, Ni-induced stimulation of superoxide-dismutase activity, soluble protein and proline accumulations was decreased, while the inhibition of peroxidase and catalase activities was eliminated. Calcium and Zn concentrations were increased by Ni in NO-treated seedlings, suggesting specific activation of the uptake of these elements as part of the protective processes regulated by NO. However, NO had no effect on the impact of Ni on K, Cu, Fe, and Mn concentrations. In conclusion, exogenous NO efficiently attenuates oxidative stress in bean, but does not prevent Ni-induced ion leakage.

Jemcov I.,University of Belgrade
Environmental Earth Sciences | Year: 2014

Rational use of karst water resources depends considerably on the existence of a successful approach to estimating karst groundwater potential for exploitation. The term groundwater potential for exploitation involves the application of regulatory measures affecting natural outflow regime. Generally, the concept of controlling the artificial discharge regime is based on two principles. The first one, the “borrowing” of water from deeper (storage) part of storage, is based mainly on the construction of groundwater wells. The second one, considers increasing dynamic reserves by providing additional artificial water storage thereby controlling the groundwater discharge regime, is based on the construction of underground dams. This paper examines how these two concepts can be used to increase potential groundwater usage from two karst springs in Serbia—St. Petka and Perućac. The ability to potentially increase the amount of karst ground water available for future exploitation may facilitate and give important directions to the future research. © 2013, Springer-Verlag Berlin Heidelberg.

Devic G.J.,University of Belgrade
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2016

ABSTRACT: Eight samples of powdered brown coal (Krepoljin coal basin, Miocene age) were successively extracted by two extractants at room temperature: bidistilled water, Me1, and 2 M MgCl2 solution, Me2. Large amounts of Ni and Zn are leached from the coal deposit by water. On the contrary, no significant amounts of Pb and Cu are washed under normal conditions. Also, the mobility of Zn and Ni especially depends, to a high extent, on ionic strength. It can be assumed that the humic acids co-extracted during water leaching, Me1, and being a highly competitive ligand for metal ions, will act as a disturbing agent in metal speciation procedure in coals. This assumption is supported by the obtained significant correlation between the Me1:Me2 ratio and the humic acid complex stability constants. © 2016 Taylor & Francis Group, LLC.

Cvetkovic B.,University of Belgrade
SISY 2011 - 9th International Symposium on Intelligent Systems and Informatics, Proceedings | Year: 2011

The paper presents the new algorithms of PID control based on fractional calculus (FC) and optimal procedure in the position and tracking control of robotic system with 3 DOFs driven by DC motors. The objective of this work is to find out optimal settings for a fractional PIαD β controller in order to fulfill proposed design specifications for the closed-loop system, taking advantage of the fractional orders, α and β. Finally, the effectiveness of suggested optimal fractional PID control is demonstrated with a suitable robot with three degrees of freedom as the illustrative example. © 2011 IEEE.

Janevic T.,Yale University | Jankovic J.,University of Belgrade | Bradley E.,The New School
International Journal of Public Health | Year: 2012

Objective: Roma experience high levels of discrimination and social exclusion. Our objective was to examine differences in self-rated health (SRH) between Roma and non-Roma in Serbia. Methods: Using data from the 2007 Living Standards Measurement Survey in Serbia (n = 14,313), we used binomial regression to estimate the relative risk (RR) of poor (SRH) among Roma (n = 267) relative to non-Roma. We additionally conducted group comparisons of combinations of Romani ethnicity, poverty, and gender, relative to the baseline group of non-Roma males not in poverty. Results: Adjusting for age, Roma were more than twice as likely as non-Roma to report poor SRH (RR = 2.3, 95% Confidence Interval (CI) = 1.8, 2.8). After adjustment for household consumption, employment, and education, the RR was reduced to 1.6 (95% CI = 1.3, 2.0). Romani women, regardless of whether they were living in poverty or not, experienced the greatest risk of poor SRH, with risks relative to non-Roma males not in poverty of 3.2 (95% CI = 2.3, 4.2) and 3.1 (95% CI = 2.4, 4.0), respectively. Conclusion: Roma in Serbia are at increased risk of poor SRH; Romani women experience the greatest burden of poor SRH. © 2011 Swiss School of Public Health.

Bankovic M.,University of Belgrade
Constraints | Year: 2015

In this paper we consider integration of SMT solvers with the filtering algorithms for the finite domain alldifferent constraint. Such integration makes SMT solvers suitable for solving constraint satisfaction problems with the alldifferent constraint involved. First, we present a novel algorithm for explaining inconsistencies and propagations in the alldifferent constraint. We compare it to Katsirelos’ algorithm and flow-based algorithms that are commonly used for that purpose. Then we describe our DPLL(T)-compliant SMT theory solver for constraint satisfaction problems that include alldifferent constraints. We also provide an experimental evaluation of our approach. © 2015 Springer Science+Business Media New York

Kourieh R.,CNRS Research on Catalysis and Environment in Lyon | Rakic V.,University of Belgrade | Bennici S.,CNRS Research on Catalysis and Environment in Lyon | Auroux A.,CNRS Research on Catalysis and Environment in Lyon
Catalysis Communications | Year: 2013

Catalytic dehydration of fructose and its conversion to 5-hydroxymethylfurfural was studied using tungstated zirconia oxides, with various tungsten oxide loadings (1-20 wt.%). The samples were prepared by incipient wetness impregnation and thoroughly characterized using a combination of different techniques: structural, thermal and calorimetric analyses. Zirconia was predominantly present in the investigated samples in the tetragonal phase when the WO3 loading was above 10 wt.%. The samples exhibited amphoteric characteristics, as they adsorbed both ammonia and sulfur dioxide on their surface. The number of surface acid sites increased with increasing WO3 content. Fructose dehydration tests evidenced the formation of 5-hydroxymethylfurfural and by-products (formic and levulinic acids). The results show that the ratio of basic to acidic sites of the solid catalysts is the key parameter for the selectivity in 5-HMF, while the global fructose conversion was mainly related to the presence of acid sites of a given strength with 150 > Qdiff > 100 kJ·molNH3 - 1. © 2012 Elsevier B.V.

Fleischmann R.M.,University of Texas Southwestern Medical Center | Damjanov N.S.,University of Belgrade | Kivitz A.J.,Altoona Center for Clinical Research | Legedza A.,Vertex Pharmaceuticals | And 2 more authors.
Arthritis and Rheumatology | Year: 2015

Objective. To assess the efficacy and safety of oral decernotinib (VX-509; Vertex Pharmaceuticals) monotherapy in a 12-week, randomized, double-blind, placebo-controlled, dose-ranging study of patients with rheumatoid arthritis (RA). Methods. Two hundred four adults with active RA who had been unsuccessfully treated with ≥1 disease-modifying antirheumatic drug were administered placebo tablets or decernotinib twice a day at dosages of 25 mg, 50 mg, 100 mg, or 150 mg. Primary measures of efficacy at week 12 were the response rate according to the American College of Rheumatology 20% improvement criteria (ACR20) and mean change from baseline in the Disease Activity Score in 28 joints using the C-reactive protein level (DAS28-CRP). Results. At week 12, the ACR20 response rates were 39.0%, 61.0%, 65.0%, and 65.9% in the 25-mg, 50-mg, 100-mg, and 150-mg groups, respectively, and were significantly higher in the 50-mg group (P = 0.007) and the 100-mg and 150-mg groups (P = 0.002) as compared to the response rates in the placebo group (29.3%). The mean change from baseline in DAS28-CRP was greater in the 50-mg, 100-mg, and 150-mg groups as compared to the placebo group (P < 0.001). Decernotinib treatment resulted in higher ACR50 and ACR70 response rates, more patients with DAS28-CRP scores <2.6, and improvements in the Health Assessment Questionnaire disability index as compared to placebo. The most common adverse events in any decernotinib group were nausea (6.1%), headache (4.3%), an increase in levels of alanine aminotransferase (4.3%), and hypercholesterolemia (3.7%). In the groups receiving decernotinib, there was an increased risk of infections and increased liver transaminase levels. Conclusion. Decernotinib was efficacious in improving clinical signs and symptoms of RA at week 12 at dosages of 50-150 mg twice a day. Infections and increases in liver transaminase and lipid levels were noted as potential safety signals. Copyright © 2015 by the American College of Rheumatology.

Popovic V.,University of Belgrade
Journal of Clinical Endocrinology and Metabolism | Year: 2013

Identification of adults with GH deficiency (GHD) is challenging because clinical features of adult GHD are not distinctive and because clinical suspicion must be confirmed by biochemical tests. Adults are selected for testing for adult GHD if they have a high pretest probability of GHD, ie, if they have hypothalamic-pituitary disease, if they have received cranial irradiation or central nervous system tumor treatment, or if they survived traumatic brain injury or subarachnoid hemorrhage. Testing should only be carried out if a decision has already been made that if deficiency is found it will be treated. There are many pharmacological GH stimulation tests for the diagnosis of GHD; however, none fulfill the requirements for an ideal test having high discriminatory power; being reproducible, safe, convenient, and economical; and not being dependent on confounding factors such as age, gender, nutritional status, and in particular obesity. In obesity, GH secretion is reduced, GH clearance is enhanced, and stimulated GH secretion is reduced, causing a false-positive result. This functional hyposomatotropism in obesity is fully reversed by weight loss. In conclusion, GH stimulation tests should be avoided in obese subjects with very low pretest probability. Copyright © 2013 by The Endocrine Society.

Radulovic M.,University of Montenegro | Stevanovic Z.,University of Belgrade
Environmental Earth Sciences | Year: 2012

The recharge of a karst aquifer, in terms of its quantity and spatial distribution, depends on various natural factors such as climate, topography, vegetation, soil, and geology. Selection of an adequate method for assessing recharge in karst is often a matter of dispute. Multi-parameter methods using Geographical information systems tools have recently been successfully developed and applied in karstic terrains of Spain and Lebanon. Specific local conditions such as highly karstified terrains could additionally complicate such an assessment. The Montenegro karstified terrains in the southern part of the External Dinarides are characterized by a very high precipitation rate, irregular seasonal distribution, and absence of surface waters (extremely high infiltration capacity of karst). Considering such conditions, an attempt to apply existing knowledge and experiences to the development of an appropriate multi-parameter method for assessing spatial distribution of autogenous recharge has been made. The KARSTLOP method has been developed, applied, and calibrated at catchments of several large karst springs of Montenegro. Obtained results in tested catchment areas confirm that with some further improvements the KARSTLOP method could be a useful tool to support research of karstic aquifers in similar highly karstified terrains. © 2011 Springer-Verlag.

Hudec M.,INFOSTAT Institute of Informatics and Statistics | Vujosevic M.,University of Belgrade
Expert Systems with Applications | Year: 2012

A concept of integration of fuzzy data selection and classification by fuzzy Generalized Logical Condition (GLC) is presented in this paper. The GLC that extends SQL queries with fuzzy logic was developed for the purpose of fuzzy data selection. In order to classify data by generating fuzzy queries from fuzzy rules, the extension of the GLC was created. The proposed methodology leads to the integration of data selection and data classification into one entity, while the access to relational databases remains unchanged. The obtained approach was presented on data from the municipal and urban statistical database. Data selection and classification problems can often be described more naturally in terms of natural language rather than by crisp numbers. © 2012 Elsevier Ltd. All rights reserved.

Lesic A.R.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2012

Injuries of the talus represents an important part of the foot and ankle trauma. Since talar bone connect the lower limb and foot, the sequelas of its trauma could have significant influence on the function of the whole lower limb and gait. The specific vascularization of the talus results in delayed union and even in the avascular necrosis. The diagnosis of the fractures of the talus can be made on the x-rays, but sometimes real picture of the fracture pattern can be seen only in the CT scans. Ocult fractures such as osteochondral fractures and avascular necrosis can be exactly detected on MRI in aim not to be overlookded as the ankle sprain diagnosis. The precise reduction and stable internal fixation is mandatory in the treatment to enable the anatomical position of the talonavicular, talocrural and subtalar joint and to make possible early motion and rehabilitation, without weight bearing. On the other hand, crushed fractures, open fractures and the Hawkins III-IV fractures with the dislocations of the talar body sometimes needs salvage procedures like Blair or tibio-talar or tibio-calcaneal fusion.

Radetic T.,University of Belgrade | Ophus C.,Lawrence Berkeley National Laboratory | Olmsted D.L.,University of California at Berkeley | Asta M.,University of California at Berkeley | Dahmen U.,Lawrence Berkeley National Laboratory
Acta Materialia | Year: 2012

This work investigates the mechanism and dynamics of grain boundary migration driven by capillary forces via in situ electron microscopy, complemented by molecular-dynamics simulations. Using thin films of Au with the mazed bicrystal geometry, the shrinkage of island grains with 90°〈1 1 0〉 tilt grain boundaries was observed by diffraction contrast and high-resolution imaging. The grains remained cylindrical throughout the shrinkage, and there was no measurable grain rotation even at very small sizes. The rate of shrinkage was found to be erratic and inconsistent with parabolic kinetics, accelerating before complete disappearance. Residual defects were found immediately after complete shrinkage, although the type and magnitude of the defects varied from grain to grain. Measurement of the grain boundary shape anisotropy showed a preference for facets on low-index planes of the crystals, including the mirror-symmetry planes of the bicrystal. These facets were also found directly on individual images extracted from high-resolution video recordings of shrinking grains at ∼300°C. The dynamics of boundary motion were found to be limited by nucleation and propagation of steps on these facets. The cylindrical geometry and size of the experimentally observed island grains allow direct comparison with molecular-dynamics simulations on the same length scale, which reproduced many of the experimentally observed features, including non-parabolic shrinkage, absence of systematic grain rotation, step-controlled migration and dislocation debris after complete grain shrinkage. Differences between model and experiment are discussed in terms of the possible role of impurities, surfaces and interfacial steps. © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Pantelic I.,University of Belgrade
Alkyl Polyglucosides: From Natural-Origin Surfactants to Prospective Delivery Systems | Year: 2014

The on-going 'green' trend in the personal care industry coupled with global environmental concerns, place natural-origin, biodegradable and skin-friendly surfactants such as alkyl polyglucosides (APGs) in high demand. After successful use in cosmetics, sufficient data has been obtained to welcome some sugar emulsifiers into the field of drug dosage. Alkyl Polyglucosides presents a comprehensive compendium which guides a researcher from the APG-related preformulation stages to formulation processing, including the investigation of various APG-stabilized systems skin performance. This book introduces various APG representatives, their benefits in relation to certain conventional surfactants, physicochemical and interfacial properties, possible interaction with commonly used ingredients and diverse characterization techniques indispensable for the assessment of colloidal systems. The first chapter introduces alkyl polyglucosides, followed by chapters on their properties, behaviour, an overview of the patent protection mechanisms and guidelines for submitting patent applications. Finally, a conclusion surveys international patent applications involving APGs. introduces the field of alkyl polyglucoside emulsifiers, listing all the contemporary and newly synthesized APG emulsifiers. provides detailed information on various aspects of APG-based structures reveals potential of APG-stabilized vehicles as prospective delivery systems using several model drugs and cosmetic actives includes an up-to-date review of research conducted in the field of APGs, facilitating future preformulation and formulation studies for researchers offers a concise and practical compendium of characterization techniques. © 2014 Elsevier Ltd. All rights reserved.

Ding B.,Johannes Kepler University | Hrelescu C.,Johannes Kepler University | Arnold N.,Johannes Kepler University | Isic G.,Johannes Kepler University | And 2 more authors.
Nano Letters | Year: 2013

Spectral and directional reshaping of fluorescence from dye molecules embedded in self-assembled hybrid plasmonic-photonic crystals has been examined. The hybrid crystals comprise two-dimensional hexagonal arrays of dye-doped dielectric nanospheres, capped with silver semishells. Comparing the reshaped fluorescence spectra with measured transmission/reflection spectra and numerical calculations reveals that the spectral and directional reshaping of fluorescence is the result of its coupling to photonic crystal Bloch modes and to void plasmons localized inside the silver caps. © 2013 American Chemical Society.

Kostic M.M.,WIPL D d.o.o. | Kolundzija B.M.,University of Belgrade
IEEE Transactions on Antennas and Propagation | Year: 2013

This paper presents a general theory of maximally orthogonalized div-and curl-conforming higher order basis functions (HOBFs) over generalized wires, quadrilaterals, and hexahedra. In particular, all elements of such bases, necessary for fast and easy implementation, are listed up to order $n=8$. Numerical results, given for div-conforming bases applied in an iterative method of moments solution of integral equations, show that the condition number and the number of iterations are a) much lower than in the case of other HOBFs of polynomial type and b) practically not dependent on the applied expansion order. © 2013 IEEE.

Bankovic-Ilic I.B.,University of Nis | Stojkovic I.J.,University of Belgrade | Stamenkovic O.S.,University of Nis | Veljkovic V.B.,University of Nis | Hung Y.-T.,Cleveland State University
Renewable and Sustainable Energy Reviews | Year: 2014

Biodiesel, an alternate and ecologically acceptable substitute for the conventional fuel, is usually produced from a wide range of edible vegetable oils, which are normally used for human consumption and whose prices are expected to increase in the future. In this regard, reliable and low-cost raw materials have increasingly drawn interest for biodiesel production, such as by-products of the meat-processing industries or waste animal fats. This paper provides a review of the different methods employed for biodiesel production from waste animal fats employing transesterification reaction. The aim of this paper is to present the exploitation possibilities of waste animal fats as low-cost feedstocks for biodiesel production. Also, the various methods for treatment of waste animal fats such as chemical (homogeneous and heterogeneous) and enzyme catalysis as well as non-catalytic processes were considered with emphasis on the influence of the operating and reaction conditions on the process rate and the ester yield. In depth discussions were given to the process optimization, kinetics and possibilities for improvement of biodiesel production from waste animal. © 2014 Elsevier Ltd.

Rasuo B.,University of Belgrade
Aeronautical Journal | Year: 2011

In this note, the experimental results of wind-tunnel measurements of lift coefficient and lift-curve slope for aerofoil NACA 0012 obtained from the VTI-Institute Zarkovo, are presented. The results were obtained from tests and integrations of surface staticpressure data over a model of the NACA 0012 aerofoil section. The data were obtained for a free-stream Mach number range of 0-25-0-8 and a chord Reynolds number range of 2-25MRe. The essential results of these measurements along with the results from other authors are presented and evaluated. The principal factors which influence the accuracy of two-dimensional wind-tunnel test results are analysed. The influences of Reynolds number, Mach number and wall interference with reference to solid and flow blockage as well as the influence of side-wall boundary-layer control arc analysed. Interesting results brought to light the Reynolds number effects of the test model versus Reynolds number effects of the facility in subsonic and transonic flow as well as the effects of the side-wall boundary-layer control and wall interference.

Brodic D.,University of Belgrade
Journal of Electrical Engineering | Year: 2011

In this manuscript the algorithm for identification of the initial skew rate for printed text is presented. Proposed algorithm creates rectangular hull around all text characters. Combining nearby rectangular hulls form objects. After applying mathematical morphology on it, the biggest object is characterized as well as selected. Rectangular hull gravity center forms reference points on these objects used as a base for calculation ieestimation of the initial skew rate. Using the least square method, initial skew rate is calculated. Comparative analysis of the origin and estimated skew rate is presented as well as discussed. Algorithm is examined with a number of printed text examples. Proposed algorithm showed robustness for skewness of printed text in the wide range. © 2011 FEI STU.

Popovic A.,University of Belgrade | Djordjevic D.,Chemistry Center
Energy Sources, Part A: Recovery, Utilization and Environmental Effects | Year: 2015

Eight samples each of coal ash taken from active, currently filled, and passive, previously filled cassettes of "Nikola Tesla A" power plant dump (Obrenovac near Belgrade, Serbia) were subjected to a sequential extraction, comprising of the following five phases: distilled water, 1 M ammonium acetate, 0.2 M ammonium oxalate/0.2 M oxalic acid, acidic solution of H2O2, and 6 M solution of HCl. Leached concentrations were discussed from the standpoint of their environmental significance, keeping in mind the processes occurring during and after coal ash transport to the dump, as well as the concentrations washed from the original filter lignite ash. © Taylor and Francis Group, LLC.

OBJECTIVE: to compare ultrasound (US) changes of the painful shoulder between patients with rheumatoid arthritis (RA) and patients with degenerative shoulder disease (DSD). PATIENTS AND METHODS: Patients with painful shoulder (n=178) were divided according to clinical diagnosis made by rheumatologist: Group1-77 patients with RA, Group2-101 patients with DSD. US changes were evaluated by linear transducer 7.5 MHz for: long head biceps tendon-LHB, supraspinatus tendon-SSP, infraspinatus tendon-ISP, subscapularis tendon-SSC, subacromial/subdeltoid bursa-SA/SD-B, glenohumeral joint effusion-JE, bone cartilage-BC and humeral erosions-HE. The ultrasound examiner was blinded for clinical findings, diagnosis and patient identification. RESULTS: Frequent pathological changes were found in: SSP tendon (84.4% RA and 71.7% DSD), LHB tendon (81,8% RA and 69,3% DSD), ISP tendon (58.4% RA and 56.4% DSD) and SSC tendon (49,4% RA and 46,5% DSD) (p=0.045 p=0.058 p=0.951 and p=0.710 respectively). Evaluating changes separately, statistical differences were noted in: LHB tenosynovitis, SSP tendon rupture (three times more in RA patients), ISP tendon rupture (five times more in RA patients), as well as in glenohumeral JE, BC reduction and HE (p=0,019 p=0.001 p=0.005 p=0.000 p=0.003 and p=0.007, respectively). LHB tendon pathology (tendinopathy, subluxatio and rupture), SSC tendinopathy, global SSP and ISP tendinopathy as well as bursitis of SA/SD did not show statistical difference between the patient groups. Using logistic regression model, the following set of items: glenohumeral JE, BC reduction and HE has shown to be distinctive between RA and DSD group. CONCLUSION: Ultrasound detected different frequencies of LHB tenosynovitis, SSP and ISP tendon ruptures, glenohumeral JE, BC reduction and HE in RA and DSD patients comparisons. Combination of glenohumeral joint effusion, bone cartilage reduction and humeral erosions was able to identify patients with RA in a population of patients with painful shoulder disease with a moderately high degree of confidence.

Simic V.,University of Belgrade
Metalurgia International | Year: 2013

As various resources are rapidly being depleted, efficient automobile shredder residue (ASR) processing is considered as one of the most important methods to promote sustainable development. In this review paper, we presented a holistic view of the ASR problem by covering a wide range of peer-reviewed journal papers. The purpose of this review paper is to give an extensive content analysis overview of the literature published in the period 2003-2012. In addition, the major classification scheme and a distribution list of journal papers published in the considered period are created to identify the primary publication outlets. Finally, on the basis of the performed review, several important recommendations for the future research are given and briefly discussed.

Vasilic M.,University of Belgrade
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

I examine the idea that our world is a branelike object of negligible influence on the bulk spacetime. No particular action functional is specified. Instead, the probe brane dynamics is derived from the universally valid stress-energy conservation equations. As an example, I study the case of a three-sphere in the five-dimensional Minkowski spacetime. The resulting four-universe turns out to depend on the equation of state of the brane constituent matter but differs from that of general relativity. One observes that, for every general relativistic universe, there exists a brane universe of equal geometry but a slightly different equation of state. As for the stability of brane universes, I find that no equation of state leads to a stable solution. However, the situation changes if the bulk spacetime has a Euclidean signature. In this case, a class of stable cosmological solutions is obtained. The brane vibrations are guided by the covariant Klein-Gordon equation with an effective metric of the Minkowski signature. It is this effective metric that local observers actually detect. As a consequence, the detected Universe is of bouncing type, with an accelerating expanding phase. © 2013 American Physical Society.

Pajic-Lijakovic I.,University of Belgrade
Progress in Biophysics and Molecular Biology | Year: 2015

Various modeling approaches have been applied to describe structural changes of the erythrocyte constituents under osmotic stress. The constituents: (1) the lipid bilayer, (2) the actin-spectrin cortex, (3) the trans-membrane protein band 3, (4) the intracellular hemoglobin contribute to the relaxation phenomenon. Cells response includes the successive sub-bioprocesses: (1) erythrocyte swelling, (2) lifetime of the lipid structural integrity and the rearrangements of trans-membrane protein band 3, (3) the reversible hemolytic hole formation and hemoglobin release to surrounding solution. Herein, an attempt is made to discuss and connect various modeling approaches on various time scales which have been proposed in the literature in order to shed further light to this complex phenomenon which induces the erythrocyte to ghost phase transition.The results indicate that the erythrocyte swelling rate represents the key control factor for the structural ordering of the cell parts which induces anomalous nature of energy dissipation. © 2014 Elsevier Ltd.

Gieseler J.,ICFO - Institute of Photonic Sciences | Spasenovic M.,ICFO - Institute of Photonic Sciences | Spasenovic M.,University of Belgrade | Novotny L.,ETH Zurich | And 2 more authors.
Physical Review Letters | Year: 2014

We study the dynamics of a laser-trapped nanoparticle in high vacuum. Using parametric coupling to an external excitation source, the linewidth of the nanoparticle's oscillation can be reduced by three orders of magnitude. We show that the oscillation of the nanoparticle and the excitation source are synchronized, exhibiting a well-defined phase relationship. Furthermore, the external source can be used to controllably drive the nanoparticle into the nonlinear regime, thereby generating strong coupling between the different translational modes of the nanoparticle. Our work contributes to the understanding of the nonlinear dynamics of levitated nanoparticles in high vacuum and paves the way for studies of pattern formation, chaos, and stochastic resonance. © 2014 American Physical Society.

Markovic G.Z.,University of Belgrade
Advances in Electrical and Computer Engineering | Year: 2016

Wavelength converters placement (WCP) in alloptical WDM networks belongs to the class of hard combinatorial optimization problems. So far, this problem has been solved by various heuristic strategies or by application of metaheuristic approaches such as genetic algorithms (GA), particle swarm optimization (PSO), differential evolution (DE), etc. In this paper, we introduce the application of Bee Colony Optimization (BCO) metaheuristic to solve the WCP problem in all-optical WDM networks. Numerous studies prove that BCO is a fast, robust and computationally efficient tool in tackling complex optimization problems. The objective of the proposed BCO-WCP algorithm is to find the best placement of limited number of wavelength converters in given optical network such that the overall network blocking probability is minimized. To evaluate the performances of the BCO-WCP algorithm, numerous simulation experiments have been performed over some realistic optical network examples. The blocking probability performance and computational complexity are compared with optimal solution obtained by exhaustive search (ES) approach as well as with DE and PSO metaheuristics. It will be shown that the BCO-WCP algorithm is not only be able to produce high quality (optimal) solution, but significantly outperforms the computational efficiency of other considered approaches.

Lesic A.R.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2012

Since the ancient times, man was faced with the problem of fracture treatment, which is first described in the records from ancient Egypt. Ever since, many treatment methods have been developed, but the real revolution in the fracture treatment was achieved by internal fixation. Since it was described for the first time, at the end of the 18th century, this method has continuously developed, but sterilization, radiographies, anaesthesiology, antibiotics made this surgery modern and safe. The great ideas and practical solutions of the new methods were done by Albin Lambotte, William Arbuthnot Lane, Robert Danis, William Hey Groves. They lead to the expansion of this method and truly made the principles for the future AO school. New methods, biological internal fixation, minimally invasive procedures, new technologies and devices for internal fixation are introduced in the surgical practice daily.

Nikolic M.,University of Belgrade
Pediatric Dermatology | Year: 2014

Pustular psoriasis (PP) is rare in children. The small number of reported cases makes deciding on treatment and follow-up challenging. The current study was an evaluation of treatment approaches and courses of PP in 18 children diagnosed and followed over a 20-year period. From 1992 to 2011 we treated 1,447 children with psoriasis, 18 of whom had PP. Follow-up was 2 to 19 years. At the time of initial manifestation of PP, our patients were 1.5 months to 16 years old. Seven patients had a previous history of psoriasis vulgaris. Three children entered long-term remission after one pustular attack, 10 developed psoriasis vulgaris, 2 are currently under treatment, and 3 were lost to follow-up. Treatment with acitretin, cyclosporine, or methotrexate was efficacious and well tolerated. PP is rare, but according to our experience, it has a good prognosis in children. © 2014 Wiley Periodicals, Inc.

Stankovic G.,University of Belgrade | Lassen J.F.,Copenhagen University
EuroIntervention | Year: 2015

Bioresorbable coronary scaffolds (BRS) may offer potential advantages compared to metallic DES, aiming to restore vessel patency without implanting a permanent prosthesis, which may be especially important for bifurcation treatment. On the other hand, there are some inherent limitations, which may impact on the widespread use of BRS. In the current article we discuss the bench testing data and initial clinical results on BRS use in bifurcation lesions presented during European Bifurcation Club (EBC) meetings and review some of the limited number of published real-world registry results. © 2015 Europa Digital & Publishing. All rights reserved.

Djordjevic M.L.,University of Belgrade
Current Urology Reports | Year: 2014

Surgical treatment of long urethral stricture disease remains one of the most challenging problems in urology. In recent years there has been continuous discussion with regard to the etiology, location, length, and management of extensive urethral stricture disease. Various tissues such as genital and extragenital skin, buccal mucosa, lingual mucosa, small intestinal submucosa, and bladder mucosa have been proposed for urethral reconstruction. The most frequent questions pertain to the optimal technique for urethroplasty and the optimal graft for substitution urethroplasty, as judged by both patient satisfaction and outcome success. We review the recent literature with respect to any new information on graft urethroplasty for extensive urethral stricture. © 2014 Springer Science+Business Media.

Golic K.,Union University of Serbia | Kosoric V.,SEEEA D.o.o. | Furundzic A.K.,University of Belgrade
Renewable and Sustainable Energy Reviews | Year: 2011

The building sector, which accounts for about 40% of total energy consumption in Europe, offers various possibilities for achieving higher energy efficiency by introducing distributed RES. As 20% of total energy consumption in this sector is used for water heating, it follows that 8% of total energy in Europe is consumed for water heating purposes, which provides great opportunities for energy savings. Solar water heating systems (SWHSs) are a suitable technology for renewable energy source (RES) exploitation to be applied in residential building refurbishment that generate both fossil fuel savings and reductions in CO2 emissions. Due to its complexity, SWHS integration requires a comprehensive approach including consideration of the functional and aesthetic, energy performance, and economic and ecological aspects from conceptual design through to design realization. This article defines a general model of SWHS integration in residential building refurbishment. The model is divided into several basic phases in order to facilitate problem-solving and to enable the individual optimization processes for variant design. The phases are systematically analyzed and a proper procedure and/or methods are established to solve them. At the very beginning of the suggested problem-solving procedure, the measures 'Building Potential', P̃B, and 'Degree of Feasibility', pB, are first introduced in order to estimate the suitability of SWHS integration. A Multi-Criteria compromise ranking method, is recommended for a comprehensive evaluation of design variants and for the selection of the optimal SWHS integration Design Variant. The proposed general model is also applied for solving a real problem - namely, the integration of SWHS through the refurbishment of residential buildings in the suburb of "Konjarnik" in Belgrade, Serbia, which is one of the many that were built in Belgrade after the Second World War. © 2010 Elsevier Ltd.

Krstajic P.M.,University of Belgrade | Peeters F.M.,University of Antwerp
Physical Review B - Condensed Matter and Materials Physics | Year: 2013

The relation between the energy and momentum of plasmarons in bilayer graphene is investigated within the Overhauser approach, where the electron-plasmon interaction is described as a field theoretical problem. We find that the Dirac-like spectrum is shifted by ΔE(k) ∼100÷150meV depending on the electron concentration ne and electron momentum. The shift increases with electron concentration as the energy of plasmons becomes larger. The dispersion of plasmarons is more pronounced than in the case of single layer graphene, which is explained by the fact that the energy dispersion of electrons is quadratic and not linear. We expect that these predictions can be verified using angle-resolved photoemission spectroscopy (ARPES). © 2013 American Physical Society.

Kesic V.,University of Belgrade | Poljak M.,University of Ljubljana | Rogovskaya S.,Moscow Medical Academy
Cancer Epidemiology Biomarkers and Prevention | Year: 2012

Cervical cancer is an important public health care problem in Europe. The overall incidence rate of cervical cancer in Europe is 10.6 per 100,000. However, within Europe, the incidence rates significantly differ, being lower in Western Europe where prevention programs are better developed. Significantly higher are the incidence and mortality rates in Central and Eastern Europe, being in close correlation to the intensity of organized screening. Human papillomavirus (HPV) vaccines are being delivered to the low-incidence populations that already have extensive screening programs, whereas the high-incidence countries have not implemented the vaccination programs yet. The resolution of the problem of cervical cancer control in Europe will be a matter of the implementation of public health care programs across the whole continent. © 2012 AACR.

Mrcross D Sign Enovic T.,University of Belgrade
Journal of Applied Engineering Science | Year: 2011

Urban design is nowadays challenged by contemporary concept of regeneration. Regeneration meens creating sustainable places, with specific identity, protection and promotion of cultural values, social cohesion and economic prosperity. The aim of the paper is to discussa role of urban design as a transformative insrument in the regeneration process. It will question the possibilities of urban design to provide strategic framework for regeneration through the process that enable creative milieu for integration of different developmental aspects and interests in plural society. The scope of the research is bounded by the urban design process in line with rational and collaborative approach in urban decision making. The theoretical and conceptual framework will be elaborated on the case of Plan of tourist valorisation of Golubac fortress in Serbia, as a place of great cultural importance and as a generator of socio-economic development in Municipality of Golubac. Describing an integrative model for urban design as an instrument for regeneration is a main contribution of the paper. Expected results of the research are definition of basic principles for achieving sustainable places in regeneration.

Tasic N.N.,University of Belgrade
Quaternary International | Year: 2015

The site of Vinča is often regarded as a yardstick for the entire Late Neolithic period of southeast Europe. Neolithic farmers, cattle-breeders, fishers, hunters, craftsmen, tradesmen and artists lived here for more than a millennium between 5600 and 4500 B.C. The site contains more than 9m of cultural deposits, and its exceptional position at the crossroads of natural routes, at the bank of the River Danube, between the vast Pannonian plain and hilly inland made it ideal for scientific research. The site of Vinča-Belo Brdo became known among archaeologists and general public soon after its discovery in 1908. Since then, there three generations of archaeologists have been excavating here. Miloje M. Vasić will be remembered as the first one to bring to light artefacts and dwelling objects of what later became known as the Vinča culture. He had excavated the entire cultural deposit in ten campaigns between 1908 and 1934at the central part of the site and discovered at least ten dwelling horizons, all yielding rich and abundant archaeological material. The excavations of 1978-1987, led by N. Tasić, D. Srejović and G. Marjanović-Vujović, have ascertained the existence of post Neolithic dwelling horizons dated in the Copper Age, late Bronze Age and Medieval periods. Archaeological material from the site that has been excavated in the course of 105 years has been thoroughly studied, analysed, and published. It seems that it has given all the answers regarding internal division, style and function of pottery, procurement of raw materials, and relationship with other contemporaneous populations, but there are questions which cannot be answered by traditional archaeological means. The ongoing research at Belo Brdo in Vinča which started in 1998 and directed by the author of this text focuses not only on archaeological research but also on attracting and involving experts from different scientific disciplines. Archaeo-botany, archaeo-zoology, geology, geophysics, chemistry, IT, soil sciences, and geography will be used in our attempt to reconstruct some aspects of the palaeoenvironment of the site of Vinča. These new results of applied sciences, combined with archaeological knowledge, will help us answer much more complex questions concerning the relationship of human populations and their environment; explain some of the choices these people made; and perhaps give us an answer as to why they had left the site by the end of the Neolithic. © 2015 Elsevier Ltd and INQUA.

Vuksanovic J.R.,University of Belgrade
International Journal of Speech-Language Pathology | Year: 2015

Purpose: The aim of this paper is to explore the relationship between language development and the frequency of social interaction (SI) behaviours during language acquisition in late-talking (LT) children who exhibit delays in expressive vocabulary development but have age-appropriate cognitive skills.Method: The research consists of a longitudinal study with a first test followed by two re-tests 5 months apart, in which LT children were compared to 5-months-younger typically-developing (TD) children.Result: Data showed that LT children performed significantly fewer initiation of SI behaviours, but no differences between groups in responding to SI behaviours were observed. Furthermore, LT children who have lower language comprehension scores initiate social interaction more frequently.Conclusion: The results showed that LT children seem to be less active in starting social interaction and participation, but, once they get involved, they respond similarly to TD children of comparable expressive language competence. Additionally, the correlation pattern between the frequency of SI behaviours and language functions showed that LT toddlers with more prominent receptive language delay are more interested in initiating interaction with their partner, thus suggesting that they need a partner's "scaffolding" to overcome this lack. © 2015 © 2015 The Speech Pathology Association of Australia Limited.

Krdzavac N.,University of Belgrade | Gasevic D.,Athabasca University
Knowledge-Based Systems | Year: 2011

In this paper, we propose an extension of the SROIQ description logic (DL) in order to support part-part relations among concepts in knowledge representation. The proposed extension introduces a conjunction of a pair of role inclusion axioms (RIAs) and defines quasi simple roles. In our proposal, we define the syntax, semantics and knowledge base for the extension of the SROIQ DL. We also present a sound and complete tableau algorithm for the SROIQ DL extension. Finally, we give an analysis of the expressiveness of the proposed extension of the SROIQ DL for modeling part-part relations and compare it with the state of the art in the area. © 2010 Published by Elsevier B.V. All rights reserved.

Kartelj A.,University of Belgrade
Journal of Multiple-Valued Logic and Soft Computing | Year: 2015

The paper presents an improved electromagnetism-like method (EML) for solving the feature selection problem. The objective function of EML is calculated as a classification accuracy, while the feature reduction rate is used as a comparison index. Efficient local search procedure and a solution scaling mechanism enforce better search process exploitation. The speedup of the objective function evaluation is achieved by introducing caching procedure for EML. EML is tested in two separate experiments, the first one is based on 13, and the second on 6 real life instances. The results show that the presented approach outperforms previously introduced EML algorithm and genetic algorithm in 10 out of 13 cases, with respect to the feature reduction rate. The running times are in some cases up to two orders of magnitude shorter. In the second experiment, EML performed better than two variants of particle swarm optimization technique in 3 out of 6 cases. © 2015 Old City Publishing, Inc.

Simic A.,University of Belgrade
Acta chirurgica Iugoslavica | Year: 2012

Barrett's esophagus (BE) is a well established precursor of esophageal adenocarcinoma. Both, surveillance and therapeutic strategies have been proposed over the years. Recent deve-lopment of endoscopic radiofrequency ablation (RFA) brought new perspectives in the treatment of BE, with excellent initial results. The study of 40 pts with macroscopically visible BE on endoscopy and biopsy proven goblet cells presence, was conducted from January 2010 until March 2012. In all pts a complete symptomatic, endoscopic and manometric evaluation was performed. Initially RFA HALO 90 and 360 were performed in 28 and 12 pts respectively. Repeated treatments were conducted in 7 pts. The overall number was 50, while the mean number of RFA procedures per patient was 1.25. The mean circumferential length and maximal extent of BE were 1.61 and 3.29 cm respectively. We did not encounter esophageal perforation or hemorrhage during the procedure. Complications were transient short-term retrosternal pain (23 pts) and dysphagia (11 pts). Three months after the RFA mean values of cumulative symptom and heartburn score dropped significantly (p < 0.05). Functional diagnostics did not disclose any statistically significant decrease of lower esophageal sphincter pressure or esophageal body contraction amplitudes. One year foIlow-up was obtained in 26 pts and revealed a complete macroscopically visible BE eradication. So far, in 19 pts a laparoscopic Nissen fundoplication was performed up to 3 months after complete RFA BE eradication. HALO RFA procedure is safe and very effective in the treatment of pts with BE, does not lead to esophageal function impairment, and produces no long term and serious side effects.

Vujovic P.,University of Belgrade
Advances in Physiology Education | Year: 2016

Making the transition from more traditional to more interactive lecturing can be successfully achieved by applying numerous teaching techniques. To use lecture time in the most efficient way, a lecturer should first instruct students to acquire basic knowledge before coming to class. Various in-class activities then can be used to help students develop higher thinking skills and gain better understanding of the studied material. These in-class activities can take many forms (multiple-choice questions of various complexities, compare-and-contrast tasks, quantitative and problemsolving tasks, questions dealing with interpretations of tables, graphs, and charts, etc.) and should be designed to help student integrate their knowledge, to facilitate communication among students, and at the same time to allow the lecturer to closely monitor the learning process as it happens in the classroom. © 2016 The American Physiological Society.

Konings R.,Technical University of Delft | Kreutzberger E.,Technical University of Delft | MaraS V.,University of Belgrade
Journal of Transport Geography | Year: 2013

This paper examines ways in which the handling of container barges in the seaport of Rotterdam could be improved with the ultimate aim of expanding the role of barges in the transportation of containers to the hinterland. It argues that the replacement of the present barge services with hub-and-spoke networks would be a promising strategy. The main purpose of the paper is to point out that hub-and-spoke networks can be set up in different ways and to explore the different impacts that these can have on their economic feasibility. A cost model is presented which compares the cost performance of present services to the hinterland with that of the different settings in the hub-and-spoke network, i.e. type and size of vessel, the barge-handling process in the hub, the location of the hub and the handling process at the seaport terminal. The results show that hub-and-spoke has the potential to deliver a better cost performance provided the handling costs in the hub can be kept within limits. © 2013 Elsevier Ltd.

Jecmenica-Lukic M.,University of Belgrade | Poewe W.,University of Innsbruck | Tolosa E.,University of Barcelona | Wenning G.K.,University of Innsbruck
The Lancet Neurology | Year: 2012

Diagnostic criteria for multiple system atrophy are focused on motor manifestations of the disease, in particular ataxia and parkinsonism, but these criteria often cannot detect the early stages. Non-motor symptoms and signs of multiple system atrophy often precede the onset of classic motor manifestations, and this prodromal phase is estimated to last from several months to years. Autonomic failure, sleep problems, and respiratory disturbances are well known symptoms of established multiple system atrophy and, when presenting early and preceding ataxia or parkinsonism, should be regarded as evidence of premotor multiple system atrophy. An early and accurate diagnosis is becoming increasingly important as new neuroprotective agents are developed. © 2012 Elsevier Ltd.

Djordjevic M.,University of Belgrade
Nuclear Physics A | Year: 2013

Reliable predictions for jet quenching in ultra-relativistic heavy ion collisions require accurate computation of radiative energy loss. While all available energy loss calculations assume zero magnetic mass, in accordance with the one-loop perturbative calculations, different non-perturbative approaches report a non-zero magnetic mass at RHIC and LHC. We generalized the dynamical energy loss formalism, to consistently include a possibility for existence of non-zero magnetic screening. We show that this generalization indicates a fundamental constraint on electric to magnetic mass ratio, which appears to be supported by lattice QCD simulations. Jet suppression patterns, obtained from this newly developed generalization, show reasonable agreement with the available RHIC and LHC measurements. © 2012 Elsevier B.V.

Djordjevic M.,University of Belgrade
Journal of Physics: Conference Series | Year: 2014

Suppression of light and heavy flavor observables is one of the most important probes in studying the properties of QCD matter created at RHIC and LHC experiments. We will here summarize the most up-to-date light and heavy flavor suppression predictions for 2.76 TeV central Pb+Pb collisions at LHC. The predictions are based on our recent improvements in the energy loss calculations that take into account: i) theoretical formalism which includes finite size dynamical QCD medium with finite magnetic mass effects and running coupling, and ii) numerical procedure which includes path-length and multi-gluon fluctuations. Our theoretical predictions, obtained with no free parameters used in model testing, show a very good agreement with the experimental results for all available particle species. Our results show that the developed theoretical formalism is able to robustly explain suppression data at LHC, which strongly suggests that pQCD in Quark-Gluon Plasma can provide a reasonable description of the underlying jet physics in ultra relativistic heavy ion collisions.

Dimitrijevic M.,University of Belgrade | Jonke L.,Ruder Boskovic Institute
Journal of High Energy Physics | Year: 2011

Kappa-Minkowski space-time is an example of noncommutative space-time with potentially interesting phenomenological consequences. However, the construction of field theories on this space, although operationally well-defined, is plagued with ambiguities. A part of ambiguities can be resolved by clarifying the geometrical picture of gauge transformations on the κ-Minkowski space-time. To this end we use the twist approach to construct the noncommutative U(1) gauge theory coupled to fermions. However, in this approach we cannot maintain the kappa-Poincaré symmetry; the corresponding symmetry of the twisted kappa-Minkowski space is the twisted igl(1,3) symmetry. We construct an action for the gauge and matter fields in a geometric way, as an integral of a maximal form. We use the Seiberg-Witten map to relate noncommutative and commutative degrees of freedom and expand the action to obtain the first order corrections in the deformation parameter. © SISSA 2011.

Tadic M.,University of Belgrade
Clinical Cardiology | Year: 2015

The assessment of the volumes, function, and mechanics of the right ventricle (RV) is very challenging because of the anatomical complexity of the RV. Because RV structure, function, and deformation are very important predictors of cardiovascular morbidity and mortality in patients with heart failure, pulmonary hypertension, congenital heart disease, or arrhythmogenic RV cardiomyopathy, it is of great importance to use an appropriate imaging modality that will provide all necessary information. In everyday clinical practice, 2-dimensional echocardiography (2DE) represents a method of first choice in RV evaluation. However, cardiac magnetic resonance (CMR) remained the gold standard for RV assessment. The development of new imaging tools, such as 3-dimensional echocardiography (3DE), provided reliable data, comparable with CMR, and opened a completely new era in RV imaging. So far, 3DE has shown good results in determination of RV volumes and systolic function, and there are indications that it will also provide valuable data about 3-dimensional RV mechanics, similar to CMR. Two-dimensional echocardiography-derived strain is currently widely used for the assessment of RV deformation, which has been proven to be a more significant predictor of functional capacity and survival than CMR-derived RV ejection fraction. The purpose of this review is to summarize currently available data about RV structure, function, and mechanics obtained by different imaging modalities, primarily 2DE and 3DE, and their comparison with CMR and cardiac computed tomography. © 2015 Wiley Periodicals, Inc.

Background/Aim. Although postoperative complications are rare, postadenoidectomy hemorrhage is one of the most frequent. The aim of this prospective study was to evaluate the incidence and timing of postadenoidectomy hemorrhage requiring hemostatic control under endotracheal anesthesia. Methods. A two-year prospective study of patients undergoing inpatient adenoidectomy, with (n = 462) or without tonsillectomy (n = 589), was undertaken. Surgery was performed in endotracheal anesthesia using an adenoid curette. Every bleeding event which needed procedure in general anesthesia for its treatment was recorded. The timing of postadenoidectomy hemorrhage was classified as primary or secondary. Results. Severe bleeding following adenoidectomy with tonsillectomy which needed hemostatic control under endotracheal anesthesia occurred in only 0.19% (2/1051) patients (average age = 7.5 years). Postadenoidectomy hemorrhage was primary in both of the patients. Conclusion. Severe postoperative hemorrhage requiring hemostasis under endotracheal anesthesia can be expected in a small number of children undergoing adenoidectomy with tonsillectomy.

Simic V.,University of Belgrade
Journal of Cleaner Production | Year: 2016

The amount of material entering end-of-life vehicles (ELVs) management systems all over the EU has been reduced due to increased export of used vehicles to non-EU countries. According to the latest data, only 6.23 million ELVs were processed in 2012 (e.g.; 8.37 million ELVs were processed in 2009). Considering that currently 342 active vehicle recycling factories exist in the EU, as well as that in the last ten years the total processing capacity has been increased several times, it is clear that there is a serious conflict. This paper proposes a multi-stage interval-stochastic programming model for planning end-of-life vehicles allocation. The developed model is able to reflect dynamics in terms of decisions for ELV allocation from a multi-region waste management system to multiple vehicle recycling factories within a multi-period context. It is capable of incorporating multiple policies within the optimization framework. Uncertainties expressed as probability distributions and discrete intervals are effectively handled, based on a multi-layered scenario tree with a finite set of scenarios. A semi-hypothetical case study is conducted in order to demonstrate the potentials and applicability of the proposed model. Influences of parameter uncertainty on model solutions are thoroughly examined. Comprehensive analyses of various policy situations, associated with different levels of economic penalties and system failure risks, are presented. The proposed model is effective for solving difficult ELV allocation problems with uncertainties included as part of the formulation. It can help quantify the relationships between ELV management system profit and disruption risk of the vehicle recycling factories, and thus provide optimal ELV allocation schemes. © 2015 Elsevier Ltd.

Jovic D.M.,University of Belgrade | Jovic D.M.,University of Munster | Belic M.R.,Texas A&M University at Qatar | Denz C.,University of Munster
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

In a numerical study, we demonstrate the dimensionality crossover in Anderson localization of light. We consider crossover from the two-dimensional (2D) to the one-dimensional (1D) lattice, optically induced in both linear and nonlinear dielectric media. The joint influence of nonlinearity and disorder on Anderson localization in such systems is discussed in some detail. We find that, in the linear regime, the localization is more pronounced in two dimensions than in one dimension. We also find that the localization in the intermediate cases of crossover is less pronounced than in both the pure 1D and 2D cases in the linear regime, whereas in the nonlinear regime this depends on the strength of the nonlinearity. There exist strongly nonlinear regimes in which 1D localization is more pronounced than the 2D localization, opposite to the case of the linear regime. We find that the dimensionality crossover is characterized by two different localization lengths, whose behavior is different along different transverse directions. © 2011 American Physical Society.

End-of-life vehicle (ELV) waste flow is an important environmental concern, because of its rapidly increasing amount and special composition of hazardous substances. Its recycling is a matter of country's attitude towards supporting the environment preservation and it has emerged as a novel area of scientific research. In this paper, we presented a holistic view of the environmental engineering issues of the ELV recycling by covering a wide range of peer-reviewed journal papers. The purpose of this review paper is to give an extensive content analysis overview of the literature published in the period 2003 ÷ 2012. In addition, the major classification scheme and a distribution list of journal papers published in the considered period are created to identify the primary publication outlets. Finally, on the basis of the performed review, several important recommendations for the future research are highlighted and discussed.

Arsenovic M.,Serbian Institute for Testing of Materials IMS | Radojevic Z.,Serbian Institute for Testing of Materials IMS | Stankovic S.,University of Belgrade
Construction and Building Materials | Year: 2012

The aim of this study was to test utilization possibilities of industrial sludge in masonry industry, as well as risk of toxic elements leaching potential. Sludge is generated in a hot-dip galvanizing process after waste water neutralization. This waste is considered to be hazardous due to the presence of toxic elements, which can be fixed within heavy clay matrix after thermal treatment. Relatively large amounts of toxic metals were found in used raw materials, but their leachability reduces to a negligible level after firing at 1020 °C. The results show that sludge can be used to produce eco-friendly bricks. © 2012 Elsevier Ltd. All rights reserved.

Durr H.-B.,University of Stuttgart | Stankovic M.S.,University of Belgrade | Ebenbauer C.,University of Stuttgart | Johansson K.H.,KTH Royal Institute of Technology
Automatica | Year: 2013

Extremum seeking feedback is a powerful method to steer a dynamical system to an extremum of a partially or completely unknown map. It often requires advanced system-theoretic tools to understand the qualitative behavior of extremum seeking systems. In this paper, a novel interpretation of extremum seeking is introduced. We show that the trajectories of an extremum seeking system can be approximated by the trajectories of a system which involves certain Lie brackets of the vector fields of the extremum seeking system. It turns out that the Lie bracket system directly reveals the optimizing behavior of the extremum seeking system. Furthermore, we establish a theoretical foundation and prove that uniform asymptotic stability of the Lie bracket system implies practical uniform asymptotic stability of the corresponding extremum seeking system. We use the established results in order to prove local and semi-global practical uniform asymptotic stability of the extrema of a certain map for multi-agent extremum seeking systems. © 2013 Elsevier Ltd. All rights reserved.

Grdic Z.J.,University of Nis | Curcic G.A.T.,University of Nis | Ristic N.S.,University of Nis | Despotovic I.M.,University of Belgrade
Construction and Building Materials | Year: 2012

This paper presents a research of abrasive resistance of classic concrete and micro-reinforced concrete with two types of polypropylene fibers. Water/cement factor was varied from 0.5 to 0.7, while the content (in%) of the remaining components remained constant. An accelerated test of abrasive erosion of concrete was performed on the equipment allowing the high-velocity jet of water/sand mixture to act on the surface of the test specimens. The research results demonstrate that the abrasive resistance of concrete is in an inverse function of the water/cement factor; the concretes with higher compressive strength and higher bending strength have also the higher abrasive resistance; the micro-reinforced concretes demonstrate higher abrasive resistance in comparison to the benchmark concrete. © 2011 Elsevier Ltd. All rights reserved.

Grozdanov T.P.,University of Belgrade | Solov'Ev E.A.,Joint Institute for Nuclear Research
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

Inelastic transitions in slow ion-atom collisions are described using an adiabatic representation of the collision system, where the transition probabilities are determined by the branch points of the potential energy curves in the complex plane of internuclear separation R. As an example, the HeH2+ system is treated, in which the evolution of the branch points related to hidden, avoided, and L3 crossings in the dynamical adiabatic basis of three-body Coulomb problem as functions of parameter ω=ρv (ρ is the impact parameter and v the impact velocity) is studied. Rearrangement of hidden couplings due to the passage of L3 branch points with the increase of ω is discussed. © 2014 American Physical Society.

Djordjevic M.,University of Belgrade
Physical Review C - Nuclear Physics | Year: 2012

Jet suppression is considered to be a powerful tool to study the properties of a QCD medium created in ultrarelativistic heavy ion collisions. However, theoretical predictions obtained by using jet energy loss in a static QCD medium show disagreement with experimental data, which is known as the heavy flavor puzzle at Relativistic Heavy Ion Collisider (RHIC). We calculate the suppression patterns of pions and single electrons for Au+Au collisions at RHIC by including the energy loss in a finite size dynamical QCD medium, with finite magnetic mass effects taken into account. We here report a notably improved agreement with the experimental results compared to the static case; this agreement is robust with respect to a realistic range of magnetic mass values. Therefore, the inclusion of dynamical QCD medium effects provides an important step toward understanding the heavy flavor puzzle at RHIC. © 2012 American Physical Society.

Dmitrasinovic V.,University of Belgrade
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

In a previous paper, based on a calculation in the nonrelativistic quark model, we advanced the hypothesis that the D s(2317), D 0(2308) mesons are predominantly four-quark states lowered in mass by the flavor-dependent Kobayashi-Kubo-Maskawa 't Hooft U A(1) symmetry breaking effective interaction. Here we show similar results and conclusions in a relativistic effective chiral model calculation, based on three-light-quark (i.e., two q plus one q̄) local interpolators. To this end we classify the four-quark (three light plus one heavy quark) local interpolators according to their chiral transformation properties and then construct chiral invariant interactions. We evaluate the diagonal matrix elements of the Kobayashi-Kubo-Maskawa 't Hooft interaction between different interpolating fields and show that the lowest-lying one is always the (antisymmetric) SU(3) F antitriplet belonging to the chiral (3, 3) multiplet. We predict bottom-strange B s0 and the bottom-nonstrange B 0 scalar mesons with equal masses at 5720 MeV, the strange meson being some 100 MeV lower than in most of the quark potential models. We also predict the JP=1 + bottom-nonstrange B 1 and the bottom-strange B s1 meson masses as 5732 MeV and 5765 MeV, respectively, using the Bardeen-Hill-Nowak-Rho-Zahed scalar-vector mass relation. © 2012 American Physical Society.

Ciric-Marjanovic G.,University of Belgrade
Synthetic Metals | Year: 2013

The recent progress made in the period 2010-2012 in the preparation and application of polyaniline (PANI) composites with metals, metalloids and nonmetals is reviewed. A systematic overview of PANI composites with noble (Au, Pt, Pd, and Ag) and non-noble transition metals (Cu, Ni, Co, Fe, Ta, Zn, Mn, Zr, and rare earth metal Ce), as well as with main-group post-transition metals (Bi and Al) and alloys, is given. PANI/Si composites were in the focus of this review regarding PANI/metalloid composites, while an overview of PANI/nonmetal composites was focused on PANI/C, PANI/S and PANI/Se composites. Special attention was paid to PANI composites with C nanomaterials such as carbon nanotubes (CNTs) and graphene. Ternary PANI/metal/nonmetal composites are also comprehensively reviewed from an application point of view. © 2013 Elsevier B.V. All rights reserved.

Rasuo B.,University of Belgrade
Plastics, Rubber and Composites | Year: 2010

In this paper, the experimental results of structural vibratory testing for the light multipurpose helicopter main rotor blade of composite laminated materials are presented. The aim of the main rotor blade vibratory testing was to define the basic aeroelastic properties of the blade. This testing included the determination of the natural oscillation modes and natural frequency of the structure in oscillations, as well as defining the blade structural damping. The measurement was performed for three different full scale models with three different types of cores of the main rotor blade: Rohacell 71 polyurethane foam, Nomex aramid honeycomb and Nomex phenolic honeycomb. The results are presented in this paper. © Institute of Materials, Minerals and Mining 2010.

Recent progress in synthesis, characterization, processing and application of polyaniline (PANI), with the focus on the period 2010-2012, is reviewed. Special attention was paid to new insights in the mechanism of formation of molecular/supramolecular PANI structures. An overview of PANI nanostructures is given. Formation, structure, properties and applicability of oligoanilines (OANIs) formed as intermediates and/or final products in oxidative oligomerization/polymerization of aniline are also discussed. Advances in carbonized OANI/PANI are outlined. © 2013 Elsevier B.V. All rights reserved.

Onic D.,University of Belgrade
Astrophysics and Space Science | Year: 2013

A considerable fraction of Galactic supernova remnants (SNRs) characterize flat spectral indices (α<0.5). There are several explanations of the flat radio spectra of SNRs in the present literature. The most of models involve a significant contribution of the second-order Fermi mechanism but some of them also discuss high compressions (>4), contribution of secondary electrons left over from the decay of charged pions, as well as the possibility of thermal contamination. In the case of expansion in high density environment, intrinsic thermal bremsstrahlung could theoretically shape the radio spectrum of an SNR and also account for observable curved-"concave up" radio spectra of some Galactic SNRs. This model could also shed a light on the question of flat spectral indices determined in some Galactic SNRs. On the other hand, present knowledge of the radio continuum spectra (integrated flux densities at different frequencies) of SNRs prevent definite conclusions about the significance of proposed models so the question on flat spectral indices still remains open. New observations, especially at high radio continuum frequencies, are expected to solve these questions in the near future. Finally, as there is a significant connection between the majority of Galactic SNRs with flat integrated radio spectrum and their detection in γ-rays as well as detection of radiative recombination continua in their X-ray spectra, the analysis of high energy properties of these SNRs is very important. © 2013 Springer Science+Business Media Dordrecht.

Graovac J.,University of Belgrade
Intelligent Data Analysis | Year: 2014

A technique for automated categorization of text documents, based on byte-level n-gram profiles and a new dissimilarity measure between profiles is presented. K nearest neighbors classifier is used. The technique is language independent. It has been applied to four document collections in English, Chinese and Serbian: Reuters-21578 newswire articles, 20-Newsgroups, Tancorp and Ebart. The evaluation was done by using the micro- and macro-averaged F-1 function. The results obtained confirm that the presented technique, although very simple, in the case of Tancorp and 20-Newsgroups corpora achieves better results than other n-gram based techniques. As compared to other state-of-the-art methods, it performs better than "bag-of-words" K nearest neighbors classifier and in the case of 20-Newsgroups corpus it works even better than "bag-of-words" Support vector machines classifier. It can be successfully used in a variety of related problems. © 2014 - IOS Press and the authors. All rights reserved.

Svorc L.,Slovak University of Technology in Bratislava | Stankovic D.M.,University of Belgrade | Kalcher K.,University of Graz
Diamond and Related Materials | Year: 2014

A sensitive, selective and reliable electrochemical method for the determination of nicotine using differential pulse voltammetry on a bare boron-doped diamond electrode has been developed. Nicotine yielded a single oxidation peak at a highly positive potential of + 1.45 V (vs. Ag/AgCl/3 M KCl) in Britton-Robinson buffer solution at pH 8. The influence of supporting electrolyte, pH and scan rate on the current response of NIC was investigated. At optimized experimental conditions, a linear relation between peak current and concentration of nicotine was found for the range from 0.5 to 200 μM (0.08-32.9 mg L-1) with a detection limit of 0.3 μM (0.05 mg L-1) and a good repeatability (relative standard deviation of 2.1% at 25 μM concentration level, n = 10) was achieved without any electrode surface modification. The practical usefulness of the developed procedure was successfully demonstrated with the determination of nicotine in tobacco products and anti-smoking pharmaceuticals with results similar to those obtained by a high-performance liquid chromatography and to the contents declared by the manufacturer, respectively. Prior to analysis, the sample pretreatment includes only sonication and/or simple liquid-liquid extraction. The proposed sensor represents an effective electrochemical tool and a promising alternative for quality control analysis of products in tobacco and pharmaceutical industry. © 2013 Elsevier B.V. All rights reserved.