Performance requirements for rail fastening systems on European railway network

In order to realize interoperability of railway system, the reconstruction and modernization plan of railway network in the Republic of Serbia should be harmonized with technical requirements of European railway network. The paper presents hierarchical approach to harmonization of legal and technical regulations in the area of railway infrastructure, with special attention drawn to the rail fastening systems. Performance requirements for rail fastening systems were analysed according to the adopted standard series SRPS EN 13481 and SRPS EN 13146

Effects of hydrogen-sulfide donor, morpholin- 4-ium 4-methoxyphenyl (morpholino) phosphinodithioate, on immune cells involved in experimental autoimmune encephalomyelitis pathogenesis

Multipla skleroza (MS) je hronična, inflamacijska, demijelinizujuća, neurodegenerativna bolest centralnog nervnog sistema. U cilju boljeg razumevanja faktora koji utiču na patogenezu MS-e, kao i definisanja novih potencijalnih terapeutika, u ovoj doktorskoj disertaciji je ispitivan efekat sporooslobađajućeg donora vodonik-sulfida, GYY4137, na imunske ćelije uključene u patogenezu eksperimentalnog autoimunskog encefalomijelitisa (EAE), najčešće korišćenog životinjskog modela MS-e. GYY4137 je ostvario jasan antiiflamacijski efekat na BV2 ćelije (ćelijska linija mikroglije), dok je njegov efekat na dendritske ćelije (DĆ) diferentovane iz ćelija kostne srži C57BL/6 miševa bio ograničen. Takođe, GYY4137 nije uticao na procentualnu zastupljenost Th1 i Th17 limfocita, glavnih patogenih populacija T limfocita u patogenezi EAE-a, unutar populacije ćelija poplitealnih limfnih čvorova (PLČ) imunizovanih C57BL/6 miševa i/ili DA pacova, ali je doveo do smanjenja zastupljenosti Th17 limfocita unutar populacije imunskih ćelija izolovanih iz kičmene moždine imunizovanih pacova. S druge strane, ovo jedinjenje je dovelo do smanjenja zastupljenosti regulatornih T limfocita (Treg) unutar populacije ćelija PLČ, ali nije uticalo na njihovu zastupljenost unutar populacije imunskih ćelija izolovanih iz kičmene moždine. Mehanizam kojim je GYY4137 ostvario efekat na zastupljenost Treg unutar populacije ćelija PLČ je obuhvatao smanjenje ekspresije transkripcionog faktora FoxP3, koje je najverovatnije bilo posredovano stimulacijom njegove proteazomalne degradacije. Pored toga, ovo jedinjenje je dovelo do povećanja produkcije reaktivnih vrsta kiseonika u BV2 ćelijama i CD4+ T limfocitima izolovanim iz PLČ imunizovanih miševa. Rezultati ove doktorske disertacije ukazuju na to da GYY4137 ostvaruje imunomodulacijski efekat na imunske ćelije uključene u patogenezu EAE-a, pri čemu priroda i intenzitet ovog efekta zavise od ćelijske populacije na koju se dejstvo ostvaruje, kao i od miljea iz kojeg ćelije potiču. Takođe, ovi rezultati ukazuju na to da GYY4137 poseduje značajan antiencefalitogeni potencijal.Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, neurodegenerative disease of the central nervous system. The aim of this doctoral dissertation has been to improve knowledge about factors that influence MS pathogenesis and to define new potential MS therapeutics by examination of the effects of slow-releasing hydrogen-sulfide donor, GYY4137, on immune cells involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), commonly used MS animal model. Immunomodulatory effect of in vitro treatment with GYY4137 was investigated on BV2 cells (microglial cell line) and dendritic cells (DC) differentiated from bone marrow precursors of C57BL/6 mice. GYY4137 exerted potent anti-inflammatory effects on BV2 cells, while its effects on DC were limited. Further, GYY4137 effect on the percentage of different T cell subpopulations among cells isolated from popliteal lymph nodes (PLN) or spinal cords of immunized C57BL/6 mice and/or DA rats was evaluated. The results showed that, despite having no effect on the percentage of two major pathogenic T helper (Th) cell populations in EAE (Th1 and Th17 cells) among cells from PLN, GYY4137 reduced the percentage of Th17 among immune cells isolated from spinal cords of immunized rats. In contrast to the effect on the percentage of Th17 cells, GYY4137 reduced the percentage of regulatory T cells (Treg) among PLN cells, but not among immune cells obtained from spinal cords of immunized rats. GYY4137 accomplished its effect on the Treg percentage by reducing the relative protein expression of FoxP3, which was probably mediated by stimulation of its proteasomal degradation. Furthermore, GYY4137 potentiated reactive oxygen species generation in BV2 cells and CD4+ T cells isolated from PLN of immunized mice. The results of this doctoral thesis indicate that GYY4137 exerts immunomodulatory effects on immune cells involved in EAE pathogenesis, while the nature and intensity of these effects depend on the cell type and the milieu of cellular origin. Also, these results suggest that GYY4137 has a significant anti-encephalitogenic potential

Sustainable Railway Infrastructure and Specific Environmental Issues in the Republic of Serbia

Transport represents both need and threat to the modern human society. European transport policy aims at sustainable transport development based on the efficient use of natural resources, protection and improvement of environment, as well as the real and diverse needs of potential users. The paper points out that the development of railway infrastructure is a necessary but not sufficient condition for shaping the sustainable mobility. Railway infrastructure has to meet the requirements of the society, economy, protection and improvement of the environment. In general, electrification of railways leads to reduction of the carbon footprint. On the other hand, thermal power plants in Serbia are the main suppliers of electric power. The results of previous geotechnical laboratory testing showed that investigated fly ash could be suitable for utilisation in the railway infrastructure. This paper presents the results of laboratory tests to determine the presence of radionuclides and trace elements in fly ash samples

Biological and chemical diversity of Angelica archangelica L. — case study of essential oil and its biological activity

Garden angelica (Angelica archangelica L.), native to the northern temperate region, is widespread in Europe and Asia. Since the middle ages, it has been used for healing and as a vegetable in traditional dishes. In the modern era, it has been proven that A. archangelica has a complex chemical composition. The main derivatives that contribute to the plant’s biological activities are essential oil and coumarins. In this review, the focus is on the cross-analysis of the taxonomy of A. archangelica, and its distribution in different regions, with the presentation of the richness of its biochemical composition, which overall contributes to the widespread use of the roots of this plant in folk medicine. It belongs to the plants that were introduced to the wider area of Central, Eastern, and Southern Europe; as a medicinal plant, it represents a significant part of the medical flora of many areas. Cluster analysis of pooled data indicates a clear differentiation of chemotypes

Metode ispitivanja i tehnički uslovi za sisteme šinskih pričvršćenja za betonske pragove

In order to realize interoperability of railway system, the reconstruction and modernization plan of railway network in the Republic of Serbia should be harmonized with technical requirements of European railway network. Performance requirements for fastening systems for concrete sleepers were analysed according to the adopted standard series SRPS EN 13481 and SRPS EN 13146. The aim of the paper is to introduce engineering public in Serbia with mentioned two standard series and to facilitate their practical implementation.Program rekonstrukcije i modernizacije železničke mreže Republike Srbije treba uskladiti s tehničkim uslovima evropske železničke mreže, kako bi se realizovali zahtevi interoperabilnosti železnič kog sistema. Na osnovu usvojene serije standarda SRPS EN 13481 i SRPS EN 13146, analiziraju se tehnički uslovi za primenu sistema šinskih pričvršćenja za betonske pragove. Cilj rada jeste da se inženjerska javnost u Srbiji upozna s pomenutim serijama standarda i da se olakša njihova praktična primena

Tehnički zahtevi za izbor kvaliteta šinskog čelika

Najčešći tipovi šinskih defekata na savremenim železničkim prugama nastaju usled zamora šinskog čelika pri kotrljanju točkova železničkih vozila. Jedan od načina da se uspori njihov razvoj je primena novih tipova šinskog čelika povećane tvrdoće u krivinama većih radijusa i drugim karakterističnim deonicama koloseka. Srpski standard SRPS EN 13674–1:2017 – Primene na železnici – Kolosek – Šine – Deo 1: Vinjolove šine mase 46 kg/m i većih masa po dužnom metru, obuhvata devet vrsta perlitnog šinskog čelika tvrdoće od 200 do 440 HBW. Upravljači infrastrukture sve češće primenjuju tvrdoće šinskih čelika ≥ 350 HBW u cilju produženja životnog veka šina u koloseku. U radu su prikazane UIC preporuke u vezi primene kvaliteta šinskog čelika zasnovane na rezultatima najnovijih istraživanja i iskustava iz prakse, kao i preporuke za reprofilisanje glave voznih šina

Upravljanje šinskim defektima usled zamora materijala

Infrastructure Manager should monitor the wear of rail steel and development of defects on the running surface of rails in order to accomplish efficient lifecycle management of rails. According to the collected statistical data on wear as a function of accumulated load, it is possible to create mathematical models of rail steel wear and removal of surface defects by wear, milling and grinding of specific track sections. The paper presents the combined model of the vertical wear and cyclical grinding of the rail profile 60E1. Developed model provide the basis for com­parison of different cyclical grinding strategies from the aspect of rail lifecycle and matching the cycles of integral maintenance of ballasted track. Length of maintenance cycle for each element of superstructure was assumed according to the experience of representative European railway managers.Za efikasno upravljanje životnim vekom šine, Upravljač infrastrukture treba da prati habanje šinskog čelika i razvoj defekata na voznoj površi glave šine tokom vremena. Na osnovu prikupljenih statističkih podataka o habanju i napredovanju prslina u funkciji akumuliranog saobraćajnog opterećenja, moguće je formiranje matematičkih modela trošenja šinskog čelika usled habanja, glodanja i brušenja na karakterističnim sekcijama koloseka. U radu je prikazan model vertikalnog trošenje šine 60E1 usled vertikalnog habanja i cikličnog brušenja. Na osnovu formiranog modela moguće je poređenje različitih strategija cikličnog brušenja šine sa stanovišta njenog životnog veka i uklapanja u cikluse integralnog održavanja koloseka sa betonskim pragovima u zastoru od tucanika. Pretpostavljene su dužine ciklusa održavanja elemenata konstrukcije gornjeg stroja prema iskustvima razvijenih evropskih železničkih uprava

Performance requirements for rail fastening systems on European railway network

In order to realize interoperability of railway system, the reconstruction and modernization plan of railway network in the Republic of Serbia should be harmonized with technical requirements of European railway network. The paper presents hierarchical approach to harmonization of legal and technical regulations in the area of railway infrastructure, with special attention drawn to the rail fastening systems. Performance requirements for rail fastening systems were analysed according to the adopted standard series SRPS EN 13481 and SRPS EN 13146