Thermochromic behaviour of cobalt(II) halide complexes in multicomponent systems

U ovoj doktorskoj disertaciji proučavano je građenje i termohromno ponašanje hloro kompleksa kobalt(II) jona u tri različita medijuma: amonijum-nitrat + zformamid (z= 2, 3, 4, 5, 6 i 20), amonijum-nitrat + zN-metilformamid (z = 3, 4, 5, 6 i 20) i amonijum-nitrat +  zN,N-dimetilformamid (z = 3) u temperaturnom intervalu od 308,15 do 348,15 K. Cilj ovog istraživanja je bio određivanje stabilnosti termohromnih kompleksa kobalta(II) koji se grade sahloridnim i nitratnim jonima i molekulima rastvarača, pronalaženje kvalitativne i kvantitativne zavisnosti konstanti stabilnosti kompleksa kobalta(II) od temperature i molskog odnosa komponenti ispitivanih sistema. Termodinamički parametri, koji karakterišu reakcije asocijacije u ispitivanim sistemima izračunati su na osnovu dobijenih konstanti stabilnosti na različitim temperaturama. Drugi deo ovog rada obuhvata fizičko-hemijsku karakterizaciju ispitivanih sistema, i  to: merenje gustine, provodljivosti i njihove viskoznosti. Na osnovu dobijenih podataka razmotrene su vrste interakcija koje se javljaju među česticama rastvarača i rastvorene supstance, kao i njihov uticaj na građenje kompleksnih  čestica kobalta(II). Ispitivani sistemi su posebno interesantni, jer predstavljaju dobre medijume za ispitivanje termohromizma u praksi.In this thesis absorption spectra of cobalt(II) chloride in three ammonium nitrate binary mixtures with organic solvents (formamide, N-methylformamide and  N,N-dimethylformamide) at different temperatures (from 308.15 to 248.15 K) and compositions have been investigated in the wavelength range 400-800 nm. Influence of the temperature and composition of the mixture on complex formation between cobalt(II) and nitrate ions, chloride ions  and/or solvent molecules have been studied. Thermodynamic parameters for cobalt(II)-ligand association in different solventswere also determined. The second part of this work involves physical-chemical characterization of the studied systems, namely: density, electrical conductivity and viscosity measurements. On the basis of the obtained data, the types and nature of the solute-solvent interactions that occur, as well as their impact on the cobalt(II) complex formation were discussed. In all investigated systems, complexes of cobalt(II) change the geometry and colour from pale pink to dark blueupon addition of  chloride ions and upon heating/cooling. Hence, additional chemical energy can be stored in such system. Because the effective working temperatures match very well with that readily achievable under sunlight, these thermochromic systems present an  example of novel materials suitable for auto-regulated protection and energy storage

Epidemiološko istraživanje lajšmanijaze u Crnoj Gori 1992-2013. godine

Introduction The diseases caused by Leishmania are spread worldwide and represent a significant public health problem. Objective The aim of this study was to present the results of epidemiological surveillance of leishmaniasis in humans in Montenegro in the period from 1992 to 2013. Methods The study was planned and realized as a descriptive epidemiological study. The sample included patients of leishmaniasis in Montenegro in the period from 1992 to 2013. The health and demographic data were collected from medical records. The disease was microbiologically proven in the patients. For statistical analysis the χ2-test was used, which examined the significance of the incidence rate. Results During this period, 66 cases of leishmaniasis were identified (40 men and 26 women) aged 0 to 62 (mean 15.61±16.76 years). A visceral form of the disease was diagnosed in 65 (98%) patients, and one patient was diagnosed with cutaneous leishmaniasis. The average incidence rate for the abovementioned period is 0.48 per 100,000 inhabitants. The highest average incidence rate was identified in patients up to seven years of age (3.50 per 100,000 inhabitants). The highest average incidence rates of leishmaniasis were identified in the coastal region of Montenegro, while seasonal distribution indicates that the disease occurs throughout the year with predominance in late spring and summer. Conclusion The research has shown that Montenegro is among the countries with low incidence of leishmaniasis. Nevertheless, because of leishmaniasis re-emergence in the entire Mediterranean Basin, a comprehensive research of ecological and epidemiological characteristics of leishmaniasis, including better monitoring and notification system, is required.Uvod Oboljenja izazvana lajšmanijama su rasprostranjena širom sveta i značajan su zdravstveni problem. Cilj rada Cilj rada je bio da se predstave rezultati epidemiološkog istraživanja lajšmanijaze kod ljudi na području Crne Gore u periodu 1992-2013. godine. Metode rada Istraživanje je planirano i realizovano kao deskriptivna epidemiološka studija. Uzorak istraživanja su činili oboleli od lajšmanijaze u Crnoj Gori od 1992. do 2013. godine. Zdravstveni i demografski podaci prikupljeni su iz medicinske dokumentacije. Kod svih obolelih bolest je mikrobiološki dokazana. Za statističku analizu rezultata korišćen je χ2-test, kojim je ispitana značajnost stopa incidencije. Rezultati U navedenom periodu od lajšmanijaze je obolelo 66 osoba (40 muškaraca i 26 žena) starih do 62 godine (prosečno 15,61±16,76 godina). Kod 65 (98%) bolesnika dijagnostikovan je visceralni oblik oboljenja, a kod jednog bolesnika kožni tip lajšmanijaze. Prosečna stopa incidencije bila je 0,48 obolelih na 100.000 stanovnika. Najviša prosečna stopa incidencije bila je u uzrastu do sedam godina (3,50 na 100.000 stanovnika). Prosečne stope incidencije lajšmanijaze s najvišom vrednosti bile su u priobalju Crne Gore, dok sezonska distribucija ukazuje na to da se bolest javlja tokom cele godine s predominacijom s kraja proleća i na leto. Zaključak Naše istraživanje je pokazalo da je Crna Gora među državama s niskom stopom incidencije obolevanja od lajšmanijaze. Ipak, zbog ponovnog pojavljivanja ove bolesti u Mediteranskom basenu i značaja za narodno zdravlje, potrebno je sveobuhvatno istraživanje ekoloških i epidemioloških odlika lajšmanijaze, uključujući bolji monitoring i sistem registracije

The salting-out effect and impact of temperature on phase diagrams of aqueous biphasic systems based on novel synthesized dicyanamide ionic liquids

Pod jonskim tečnostima (JT) se podrazumevaju jonska jedinjenja koja su tečna na temperaturama ispod 100°C.1 Jonske tečnosti se sastoje od velikih, asimetričnih organskih katjona (amonijum, fosfonijum, sulfonijum, imidazolijum, piridinijum, pirolidinijum itd.) i manjih organskih ili neorganskih anjona (bromid, hlorid, dicijanamid, metansulfonat, tetrafluoroborat itd.). Dimenzije i oblik samih jona, pre svega katjona, onemogućavaju njihovo „gusto“ pakovanje i obrazovanje jonske kristalne strukture, čime se objašnjava niska temperatura topljenja i tečno agregatno stanje ovih sistema na sobnoj temperaturi.2,3 Jonske tečnosti poseduju niz jedinstvenih svojstva kao što su zanemarljiv napon pare, hemijska i termalna stabilnost, širok elektrohemijski prozor, visoku provodljivost, veliki toplotni kapacitet, podesivu hemijsku strukturu i fizičke osobine i jaku sposobnost solvatacije.4 Jonske tečnosti su ekološki prihvatljivija i pogodna alternativa isparljivim i toksičnim organskim rastvaračima. Među brojnim zanimljivim svojstvima koje poseduju hidrofilne jonske tečnosti je i njihova sposobnost da grade dvofazne vodene sisteme u kombinaciji sa neorganskim ili organskim solima. Naime, dodatak neorganske soli u vodeni rastvor jonske tečnosti uzrokuje razdvajanje tečnih faza i formiranje dvofaznog vodenog sistema.5 Bifazni vodeni sistemi mogu biti značajni pri recikliranju ili koncentrovanju hidrofilnih jonskih tečnosti iz vodenih rastvora, zatim u reakciji metateze pri sintezi novih jonskih tečnosti, a od naročitog su interesa u separacionoj hemiji. Izborom adekvatnih komponenata (jonske tečnosti i neorganske/organske soli) i jednostavnom manipulacijom sastava faza može se postići visoka selektivnost i željeni koeficijent raspodele za ekstrakciju velikog broja jedinjenja kao što su alkaloidi, lekovi, aminokiseline, proteini, hormoni, alkoholi, aromatična i fenolna jedinjenja itd.6 Ispitivanje faznih dijagrama dvofaznih vodenih sistema sa jonskim tečnostima predstavlja prvu fazu u optimizaciji uslova za ekstrakciju određenog jedinjenja. Cilj ovog rada je da se odrede ravnotežni dijagrami dvofaznih vodenih sistema {JT + neorganska so + + H2O} za novosintetisane jonske tečnosti 1-etil-3-etilimidazolijum-dicijanamid [1-C23-C2im][DCA] i 1-butil-3-etilimidazolijum-dicijanamid [1-C43-C2im][DCA] i da se ispitaju uticaji jonske tečnosti, neorgaske soli i temperature na mogućnost formiranja bifaznih vodenih sistema.In this work, novel phase diagrams for aqueous solutions of 1-ethyl-3-ethylimidazolium dicyanamide [1-C23- C2im][DCA] and 1-butyl-3-ethylimidazolium dicyanamide [1-C43-C2im][DCA] -based ionic liquids (ILs) combined with phosphate and carbonate based salts, K3PO4 and K2CO3, are reported and discussed. Merchuk equation was applied in order to correlate the experimental binodal data. It was found that K3PO4 has better salting-out ability to induce aqueous biphasic system (ABS) than K2CO3. The cation influence on the ability to form ABS is investigated for the IL with the same anion, dicyanamide [DCA]- and various alkyl chain lengths in the imidazolium N-1 position. It was found that ability to form ABS increases with the increase of the alkyl chain length on the imidazolium cation because of increasing ionic liquid hydrophobicity and poorer affinity for water. The effect of temperature and the alkyl chain length of ionic liquid on two phase formation were investigated. The experimental results show that biphasic region expands with reduction in temperature.53. savetovanje Srpskog hemijskog društva : knjiga radova; 10-11. jun 2016; Kragujevac / 53rd Meeting of the Serbian Chemical Society : Proceedings; June 10-11, 2016; Kragujeva

Epidemiological surveillance of Leishmaniasis in Montenegro, 1992-2013

Introduction. The diseases caused by Leishmania are spread worldwide and represent a significant public health problem. Objective. The aim of this study was to present the results of epidemiological surveillance of leishmaniasis in humans in Montenegro in the period from 1992 to 2013. Methods. The study was planned and realized as a descriptive epidemiological study. The sample included patients of leishmaniasis in Montenegro in the period from 1992 to 2013. The health and demographic data were collected from medical records. The disease was microbiologically proven in the patients. For statistical analysis the χ2-test was used, which examined the significance of the incidence rate. Results. During this period, 66 cases of leishmaniasis were identified (40 men and 26 women) aged 0 to 62 (mean 15.61±16.76 years). A visceral form of the disease was diagnosed in 65 (98%) patients, and one patient was diagnosed with cutaneous leishmaniasis. The average incidence rate for the abovementioned period is 0.48 per 100,000 inhabitants. The highest average incidence rate was identified in patients up to seven years of age (3.50 per 100,000 inhabitants). The highest average incidence rates of leishmaniasis were identified in the coastal region of Montenegro, while seasonal distribution indicates that the disease occurs throughout the year with predominance in late spring and summer. Conclusion. The research has shown that Montenegro is among the countries with low incidence of leishmaniasis. Nevertheless, because of leishmaniasis re-emergence in the entire Mediterranean Basin, a comprehensive research of ecological and epidemiological characteristics of leishmaniasis, including better monitoring and notification system, is required

Liquid-Liquid Equilibria in Aqueous 1-Alkyl-3-methylimidazolium- and 1-Butyl-3-ethylimidazolium-Based Ionic Liquids

In this work, novel phase diagrams for aqueous solutions of 1-alkyl-3-methylimidazolium- and 1-butyl-3-ethylimidazolium-based ILs combined with phosphate-based salts, namely, K3PO4 or K2HPO4, are reported and discussed. To correlate the binodal data, the Merchuk equation is applied. The tie lines and tie-line lengths are also presented. The anion influence on the ability to form aqueous biphasic system (ABS) is investigated for the IL with the same1-butyl-3-methylimidazolium cation, [bmim](+), and various anions, for example, salicylate, [SAL](-); trifluoromethanesulfonate, [TFS](-); dicyanamide, [DCA](-); and chloride, [Cl](-). The order of studied anions to form ABS is [TFS](-) GT [SAL](-) GT [DCA](-) GT [Cl](-). The effect of alkyl chain length on imidazolium ion on liquidliquid equilibrium is discussed in terms of increasing ionic liquid hydrophobicity and poorer affinity for water. It is shown that 1-hexyl-3-methylimidazolium chloride ionic liquid has a better ability to form ABS comparing to ionic liquid with butyl chain and the same anion. Newly synthesized ionic-liquid-containing ethyl group 1-butyl-3-ethylimidazolium bromide was also investigated, showing the influence of both ethyl group and bromide anion on the ability of ABS formation

Aqueous biphasic system formation using 1-alkyl-3-ethylimidazolium bromide ionic liquids as new extractants

In this work three 1-alkyl-3-ethylimidazolium bromide ionic liquids (alkyl = ethyl, hexyl and octyl) were synthesized applying both, conventional and microwave assisted synthetic paths. The phase diagrams for aqueous solutions of 1-alkyl-3-ethylimidazolium bromide ionic liquids as novel extractants combined with phosphate-based salts are reported and discussed in terms of aqueous biphasic system (ABS) formation. Merchuk equation was applied in order to correlate the,experimental binodal data. The liquid-liquid equilibrium data (tie-line compositions and tie-line length) were also experimentally determined by a gravimetric method. The influence of the alkyl chain length on ABS formation ability was investigated. It was found that ability to form ABS increases with the increase of the alkyl chain length on the imidazolium cation. Also, it was found that ionic liquids with ethyl group in the N-3 position better form ABS compared to those with methyl substituent. This was discussed in terms of increasing ionic liquid hydrophobicity and poor affinity for water. In order to better understand the impact of the alkyl side chain of the imidazolium ion and the efficiency of ABS formation, computer simulations were performed using investigated ionic liquids with the ethyl group in the position N-3 of the cation and different alkyl substituents in the position N-1. Also, extraction of selected organic dyes was performed to demonstrate application of studied ionic liquids as novel extractants. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved

Antioxidative status of saliva before and after non-surgical periodontal treatment

Introduction. Oxidative stress and antioxidants play an important role in the pathogenesis of inflammatory disease, including chronic periodontitis (CP). Saliva contains enzymatic (glutathione peroxidase - GPx, superoxide dismutase - SOD, etc.) and non-enzymatic (albumin - ALB, uric acid - UA, glutathione, etc.) antioxidants. Objective. The aims of this study were to investigate: a) level of SOD, GPx, UA, ALB and total antioxidative status (TAS) of saliva in CP patients before and after non-surgical treatment, and b) correlations between clinical periodontal parameters and levels of salivary antioxidants. Methods. Saliva was collected from 21 CP patients before and after non-surgical treatment. The condition of periodontium was assessed by plaque index, gingival index, bleeding on probing, probing depth and clinical attachment loss. Level of investigated antioxidants (except GPx) and TAS was determined using colorimetric method and commercial kits. GPx activity was determined using UV method and commercial kits. Results. After the treatment significant increase of UA, ALB, Gpx, TAS was detected (p0.05). A significant correlation was observed between GPx and PI (r=0.575, p=0.008), SOD and GI (r=0.525, p=0.017) before therapy, and SOD and bleeding on probing (BP) (r=0.59, p=0.006), TAS and BP (r=0.453, p=0.045) after therapy. Conclusion. These data suggest that levels of salivary antioxidants generally increase after non-surgical periodontal treatment. Correlation between some clinical periodontal parameters and level of salivary antioxidants was found. [Projekat Ministarstva nauke Republike Srbije, br. 41008

Immunohistochemical expression of cyclin-dependent kinase inhibitors p16 and p57 in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a highly malignant cancer and is the most common soft tissue sarcoma in children and adolescents, but it is rare in adults ( 50 yrs. (HR 2.447), tumors > 5 cm (HR 21.31), involvement of regional lymph nodes (HR 3.96), the presence of metastases (HR 2.53), and low p57 expression (HR 2.11) as predictors of lower OS. Tumor size, regional lymph nodes involvement, and metastases were the independent predictors after multivariate analysis, while p57 did not predict OS in an independent way. In summary, although p57 was not confirmed to be an independent predictor of OS, our results indicate that its low expression may be the marker of aggressive phenotype and poor prognosis in adult RMS patients. Also, our findings suggest that epigenetic inactivation of p16 is not important in the pathogenesis of rhabdomyosarcoma