Evidence for electron-phonon interaction in Fe1−x_{1-x}Mx_{x}Sb2_{2} (M=Co, Cr) single crystals

We have measured polarized Raman scattering spectra of the Fe$_{1-x}$Co$_{x}$Sb$_{2}$ and Fe$_{1-x}$Cr$_{x}$Sb$_{2}$ (0$\leq x\leq$0.5) single crystals in the temperature range between 15 K and 300 K. The highest energy $B_{1g}$ symmetry mode shows significant line asymmetry due to phonon mode coupling width electronic background. The coupling constant achieves the highest value at about 40 K and after that it remains temperature independent. Origin of additional mode broadening is pure anharmonic. Below 40 K the coupling is drastically reduced, in agreement with transport properties measurements. Alloying of FeSb$_2$ with Co and Cr produces the B$_{1g}$ mode narrowing, i.e. weakening of the electron-phonon interaction. In the case of A$_{g}$ symmetry modes we have found a significant mode mixing

The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller

The fractional PID controllers tuned by genetic algorithms for expansion turbine in the cryogenic air separation process

Ovaj rad se bavi realizacijom jednog novog algoritma PID upravljanja zasnovanog na računu necelobrojnog reda (fractional calculus) u proizvodnji tehničkih gasova, odnosno u procesu separacije utečnjenog vazduha. Proizvodnja utečnjenog vazduha niskog pritiska je po prvi put bila uvedena od strane Kapice gde se ekspanzija odvijala u gasnoj turbini. Za primenu u sintezi upravljanja ulazne temperature i protoka vazduha u ekspanzionoj turbini, potrebno je odrediti odgovarajuće diferencijalne jednačine kriogenog procesa mešanja dva gasa na različitim temperaturama na ulazu u ekspanzionu turbinu. Pri tome, odgovarajući model je linearizovan i dekuplovan gde su primenjeni istovremeno klasični PID kao i PIβDα kontroleri necelobrojnog reda da bi se procenio kvalitet predloženog novog upravljanja datim procesom. Skup optimalnih parametara datih kontrolera se postiže primenom optimizacione procedure bazirane na genetskim algoritmima minimizovanjem odgovarajućeg kriterijuma optimalnosti. Naš metod se fokusira u okviru kriterijuma optimalnosti na smanjenje preskoka, vreme smirenja i minimizaciju integralne greške. Simulacije sprovedene u vremenskom domenu pokazuju bolje performance optimalnog PIβDα kontrolera u odnosu na klasični optimalni PID kontroler.This paper deals with the design of a new algorithm of PID control based on fractional calculus (FC) in production of technical gases, i.e. in a cryogenic air separation process. Production of low pressure liquid air was first introduced by P.L. Kapitsa and involved expansion in a gas turbine. For application in the synthesis of the control law, for the input temperature and flow of air to the expansion turbine, it is necessary to determine the appropriate differential equations of the cryogenic process of mixing of two gaseous airflows at different temperatures before entrance to the expansion turbine. Thereafter, the model is linearized and decoupled and consequently classical PID and fractional order PIβDα controllers are taken to assess the quality of the proposed technique. A set of optimal parameters of these controllers are achieved through the genetic algorithm optimization procedure by minimizing a cost function. Our design method focuses on minimizing performance criterion which involves IAE, overshoot, as well as settling time. A time-domain simulation was used to identify the performance of PIβDα controller with respect to a traditional optimized PID controller

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

Optical properties of plastically deformed copper

Pure copper (99.99), prepared in the sample of square cross-section (10 x 10 mm2) and length about 50 mm, was extremely plastically deformed with the repeated application of Equal Channel Angular Pressing (ECAP). ECAP was applied as an effective technique for producing bulk nano-scaled structures. Optical properties of the sample were investigated using Raman spectroscopy. Two types of lines: narrow (with width of 7 cm¡1) and wide ( 40 cm¡1) are registered. Existence of two types of lines indicates that in the specimen exists nano-sized crystal structures of both Cu and CuO related with three dimensional amorphous boundary spaces, which indicates that plastic deformation of the sample did not lead to total amorphisation of the specimen

Modulacija eksperimentalnog autoimunog encefalomijelitisa (EAE) DA pacova levamizolom

We investigated the influence of an antiparasitic drug, levamisole (2,3,5,6 - tetrahydro - 6- phenyl-imidazo (2,1 - b) thiazole -hydrochloride) with potent immunomodulatory properties on the course and development of experimental autoimmune encepha-lomyelitis (EAE). EAE was induced in female Dark Agouti (DA) rats aged two months by immunization with guinea pig spinal cord in complete Freunds adjuvant. Following immunization animals were subcutaneously treated every other day with 2.2 mg/kg levamisole. The course, development and characteristics of this autoimmune process were monitored as indirect indicators of immune system activity. Our results indicate that in EAE levamisole exerts immunosuppressive effects when administered every other day from the moment of immunization until the end of the disease. This application regime and dose postponed the onset of the first clinical signs, shortened the duration of the disease, abrogated the severity of clinical symptoms and accelerated the recovery of sick animals. In the period of induction and during EAE, levamisole also decreased the severity of changes in the cerebral perivascular spaces. In the peripheral blood of levamisole treated animals with induced EAE, a significant increase of CD4-CD8+ T cells was demonstrated. Furthermore, all rats with induced EAE had decreased numbers of CD4+CD8- T cells in their blood. These changes were in correlation with clinical signs of EAE.U ovom radu su prikazani rezultati ispitivanja anthelmintika levamizola (2,3,5,6 tetrahidro - 6 - fenil - imidazo (2,1 - b) tiazol hidrohlorida) sa snažnim imunomodulatornim svojstvima na tok i razvoj eksperimentalnog autoimunog encefalomijelitisa (EAE). EAE je indukovan imunizacijom ženki pacova soja DA (Dark Agouti) starih dva meseca pomoću homogenata kičmene moždine zamorčeta u kompletnom Freundovom adjuvansu. Posle imunizacije, životinje su tretirane subkutanim injekcijama levamizola (2.2 mg/kg) svaki drugi dan a praćeni su tok, razvoj i karakteristike ovog autoimunog oboljenja kao indirektni indikatori aktivnosti imunološkog sistema. Postignuti rezultati ukazuju dalevamizol ispoljava imunosupresivno delovanje u modelu EAE ako se aplikuje svaki drugi dan od momenta imunizacije do kraja bolesti. Primenjena doza i režim aplikacije odložili su momenat pojavljivanja prvih kliničkih simptoma, skratili trajanje bolesti, ublažili ispoljavanje simptoma i ubrzali oporavak bolesnih životinja. U periodu indukcije i tokom EAE-a levamizol je smanjio stepen promena u cerebralnim perivaskularnim prostorima. U ženskoj krvi ženki pacova sa indukovanim EAE i tretiranim levamizolom uočeno je značajno povećanje broja CD4-CD8+ T ćelija. Osim toga, u obe imunizovane grupe životinja zapaženo je smanjenje broja CD4+CD8- ćelija. Ove promene su bile u skladu sa kliničkom slikom bolesti

Terapija endometritisa krmača intrauterinom instilacijom preparata na bazi zida kvasca

On the basis of our investigations it was possible to conclude that intrauterine treatment of sows with puerperal uterine infections with sterile YCW (Yeast Cell Wall) resulted in significant clinical improvement. The percent of recidivism was the lowest (10%) in groups of sows treated with 10 and 20 g of YCW. The degree of bacterial CFU (Colony Forming Units) reduction in samples of sows uterine flushings following instillation of YCW (5, 10 and 20 g) was wery high and ranged from 1361 to 1444 times, while in sows treated with Lotagen 2% solution (100 mL) this parametar was only 32. At the moment of weaning, piglets from sows treated with 10 and 20 g of YCW were heavier when compared to the control and Lotagen group and their DBWG (Daily Body Weight Gain) was higher when compared to the Lotagen and control group. Treatment of sows by IU instillation of YCW did not influence the number of piglets in the next breeding cycle.Na osnovu rezultata naših istraživanja bilo je moguće zaključiti da tretman krmača obolelih od puerperalnih infekcija materice, sterilnim preparatom dobijenim iz zida kvasca (YCW), ima za posledicu značajan klinički napredak. Procenat krmača sa recidivom je bio najniži (10%) u grupi tretiranoj sa 10 i 20g YCW. Stepen redukcije broja bakterijskih kolonija (CFU) u uzorcima dobijenih iz materice krmača posle tretmana YCW preparatom je bio veoma visok i kretao se u opsegu od 1361 do 1444 puta. Kod obolelih krmača, tretiranih rastvorom Lotagena (2%), vrednost ovog parametra je bila svega 32. U momentu zalučenja, prasad krmača tretiranih YCW preparatom u količini od 10 i 20 g bila su teža u poređenju sa prasadima krmača grupe tretirane Lotagenom i prasadima kontrolnih (neteretiranih) krmača. Osim toga i njihovi prosečni dnevni prirasti su bili veći. Tretman krmača intrauterinom instilacijom preparata na bazi YCW nije negativno uticao na broj prasadi u sledećem reproduktivnom ciklusu