112 research outputs found
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 hroniÄna, inflamacijska, demijelinizujuÄa, neurodegenerativna bolest
centralnog nervnog sistema. U cilju boljeg razumevanja faktora koji utiÄu na patogenezu MS-e, kao i
definisanja novih potencijalnih terapeutika, u ovoj doktorskoj disertaciji je ispitivan efekat
sporooslobaÄajuÄeg donora vodonik-sulfida, GYY4137, na imunske Äelije ukljuÄene u patogenezu
eksperimentalnog autoimunskog encefalomijelitisa (EAE), najÄeÅ”Äe koriÅ”Äenog životinjskog modela
MS-e. GYY4137 je ostvario jasan antiiflamacijski efekat na BV2 Äelije (Äelijska linija mikroglije), dok
je njegov efekat na dendritske Äelije (DÄ) diferentovane iz Äelija kostne srži C57BL/6 miÅ”eva bio
ograniÄen. TakoÄe, GYY4137 nije uticao na procentualnu zastupljenost Th1 i Th17 limfocita, glavnih
patogenih populacija T limfocita u patogenezi EAE-a, unutar populacije Äelija poplitealnih limfnih
Ävorova (PLÄ) imunizovanih C57BL/6 miÅ”eva i/ili DA pacova, ali je doveo do smanjenja
zastupljenosti Th17 limfocita unutar populacije imunskih Äelija izolovanih iz kiÄmene moždine
imunizovanih pacova. S druge strane, ovo jedinjenje je dovelo do smanjenja zastupljenosti regulatornih
T limfocita (Treg) unutar populacije Äelija PLÄ, ali nije uticalo na njihovu zastupljenost unutar
populacije imunskih Äelija izolovanih iz kiÄmene moždine. Mehanizam kojim je GYY4137 ostvario
efekat na zastupljenost Treg unutar populacije Äelija PLÄ je obuhvatao smanjenje ekspresije
transkripcionog faktora FoxP3, koje je najverovatnije bilo posredovano stimulacijom njegove
proteazomalne degradacije. Pored toga, ovo jedinjenje je dovelo do poveÄanja produkcije reaktivnih
vrsta kiseonika u BV2 Äelijama i CD4+ T limfocitima izolovanim iz PLÄ imunizovanih miÅ”eva.
Rezultati ove doktorske disertacije ukazuju na to da GYY4137 ostvaruje imunomodulacijski efekat na
imunske Äelije ukljuÄene u patogenezu EAE-a, pri Äemu priroda i intenzitet ovog efekta zavise od
Äelijske populacije na koju se dejstvo ostvaruje, kao i od miljea iz kojeg Äelije potiÄu. TakoÄe, ovi
rezultati ukazuju na to da GYY4137 poseduje znaÄajan 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. ā 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 plantās 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 tehniÄki uslovi za sisteme Å”inskih priÄvrÅ”Äenja 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 železniÄke mreže Republike Srbije treba uskladiti s tehniÄkim uslovima evropske železniÄke mreže, kako bi se realizovali zahtevi interoperabilnosti železniÄ kog sistema. Na osnovu usvojene serije standarda SRPS EN 13481 i SRPS EN 13146, analiziraju se tehniÄki uslovi za primenu sistema Å”inskih priÄvrÅ”Äenja za betonske pragove. Cilj rada jeste da se inženjerska javnost u Srbiji upozna s pomenutim serijama standarda i da se olakÅ”a njihova praktiÄna primena
TehniÄki zahtevi za izbor kvaliteta Å”inskog Äelika
NajÄeÅ”Äi tipovi Å”inskih defekata na savremenim železniÄkim prugama nastaju usled zamora Å”inskog Äelika pri kotrljanju toÄkova železniÄkih vozila. Jedan od naÄina da se uspori njihov razvoj je primena novih tipova Å”inskog Äelika poveÄane tvrdoÄe u krivinama veÄih radijusa i drugim karakteristiÄnim deonicama koloseka. Srpski standard SRPS EN 13674ā1:2017 ā Primene na železnici ā Kolosek ā Å ine ā Deo 1: Vinjolove Å”ine mase 46 kg/m i veÄih masa po dužnom metru, obuhvata devet vrsta perlitnog Å”inskog Äelika tvrdoÄe od 200 do 440 HBW. UpravljaÄi infrastrukture sve ÄeÅ”Äe primenjuju tvrdoÄe Å”inskih Äelika ā„ 350 HBW u cilju produženja životnog veka Å”ina u koloseku. U radu su prikazane UIC preporuke u vezi primene kvaliteta Å”inskog Äelika zasnovane na rezultatima najnovijih istraživanja i iskustava iz prakse, kao i preporuke za reprofilisanje glave voznih Å”ina
Upravljanje Ŕinskim 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 comĀparison 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 Å”ine, UpravljaÄ infrastrukture treba da prati habanje Å”inskog Äelika i razvoj defekata na voznoj povrÅ”i glave Å”ine tokom vremena. Na osnovu prikupljenih statistiÄkih podataka o habanju i napredovanju prslina u funkciji akumuliranog saobraÄajnog optereÄenja, moguÄe je formiranje matematiÄkih modela troÅ”enja Å”inskog Äelika usled habanja, glodanja i bruÅ”enja na karakteristiÄnim sekcijama koloseka. U radu je prikazan model vertikalnog troÅ”enje Å”ine 60E1 usled vertikalnog habanja i cikliÄnog bruÅ”enja. Na osnovu formiranog modela moguÄe je poreÄenje razliÄitih strategija cikliÄnog bruÅ”enja Å”ine sa stanoviÅ”ta 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 železniÄkih 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
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