Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O

The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC−H)H2O]Br•H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

Formation of niobium oxides by electrolysis from acidic aqueous solutions on glassy carbon

In this study niobium oxide films were formed without peroxo-precursors from three different mixed acidic aqueous solutions on glassy carbon. Linear sweep voltammetry and potential step were techniques used for electrochemical experiments. The simultaneous and consecutive electrochemical reduction of water, nitrate and sulphate ions provided an alkaline environment with oxygen in the near vicinity of the working cathode, which in combination with the present niobium ions, produced niobium oxides and/or oxyhydroxides on the glassy carbon substrate. The formed deposits were analyzed using scanning electron microscopy and energy dispersive spectroscopy and appear to consist of NbO, NbO2 and Nb2O5. Both the niobium and acid concentration of the electrolytes used influenced the morphology and particle size of the deposits. The formation of niobium-fluoride and hydrogen-niobiumoxide complexes is addressed

Elektrohemijsko taloženje niobijum oksida iz kiselih rastvora na staklastom ugljeniku

Electrochemical synthesis of niobium oxides from four different strongly acidic solutions onto vitreous carbon electrodes was studied. Linear sweep voltammetry and potential step techniques were used for electrochemical experiments and scanning electron microscopy and energy dispersive spectroscopy for analysis of the working electrode surface and deposits formed. Change of the working electrode potential to negative values, negative to 0.5 V vs. SCE, leads to simultaneous reduction of niobium, hydrogen, nitrate and sulphated ions, which induces alkaline media in the immediate vicinity of the electrode surface and formation of several niobium oxides and oxyhidoxides. Despite reduction of niobium ions there are no firm evidence of the permanent metal niobium clusters. Change of the electrode potential into positive direction, positive to – 1.000 vs. SCE, leads to simultaneous oxidation of niobium ions from lower oxidation state and additional formation of niobium oxides. Morphology and crystallographic forms of the deposits obtained by SEM and EDS analysis confirmed above assumptions.Elektrohemijskim putem sintetizovani su oksidi niobijuma iz četiri različita veoma kisela rastvora na elektrodi od staklastog ugljenika. U elektrohemijskim eksperimentima upotrebljavane su metode linearne cikličke voltametrije i potenciostatskog pulsa, a metode skenirajuće elektronske mikroskopije i energetsko disperzivne spektroskopije poslužile su za analizu elektrodne površine i taloga formiranog na njoj. Pri promeni radnog potencijala u negativnu stranu (a negativnije od 500 mV vs. ZKE) dolazi do simultanog odvijanja procesa redukcije niobijumovih, vodonikovih, hidroksidnih, nitratnih i sulfatnih jona, što u formiranoj baznoj sredini u neposrednoj blizini radne elektrode dovodi do nastanka nekoliko niobijumovih oksida i oksihidroksida na njenoj površini. Mada dolazi do redukcije niobijumovih jona nema čvrstih dokaza da se njihova redukcija odvija do formiranja održivih nakupina metalnog niobijuma. Pri promeni radnog potencijala u pozitivnom smeru (pri potencijalima pozitivnijim od – 1.000 vs. ZKE) dolazi do zajedničkog odvijanja oksidacije niobijumovih jona nižeg oksidacionog stanja i dodatno se formiraju niobijumovi oksidi. Morfologija dobijenih taloga i uočene kristalografske forme analizirane SEM i EDS tehnikama potvrđuju gore navedene pretpostavke

The occurrence of Trichophytosis among people and cattle on a farm in Vojvodina, Serbia

Dermatophytoses are frequent contagious fungal skin diseases that affect the skin of people and animals. Zoophile dermatophytes pose a significant problem for both human and veterinary medicine, and they are especially present among bovines. In this paper we showed a simultaneous occurrence of trichophytosis among professionally exposed people and bovines on a farm in Vojvodina, Serbia. The tested samples (skin scrapings and hair) originating from people and animals, were positive for Trichophyton verrucosum dermatophyte which was determined by applying a direct microscopic examination of the smears, as well as the isolation and identification of the agents

Syntheses and characterization of 2-acetylpyridine-aminoguanidine and its copper(II) complexes: Crystallographic and antimicrobial study

The syntheses, physico-chemical and microbiological properties of the ligand, 2-acetylpyridine-aminoguanidine dihydrogensulfate monohydrate and its five complexes with Cu(II) are described. The compounds were characterized by single crystal X-ray crystallography. Common fragments encountered in some of the structures were compared by r.m.s. overlay calculations as well as half-normal probability plots. In these complexes the chelate ligand is coordinated in its neutral form in a tridentate N-3-coordination mode, via pyridine, azomethine and imino nitrogen atoms of the aminoguanidine fragment. In these complexes the Cu(II) ion is situated in moderately or severely distorted square-pyramidal surroundings. The antimicrobial activity of the ligand and the complexes were examined against 6 selected bacterial and 3 fungal strains.This is peer-reviewed version of the following article: Vojinović-Ješić, L. S.; Radanović, M. M.; Rodić, M. V.; Živković-Radovanović, V.; Jovanović, L. S.; Leovac, V. M. Syntheses and Characterization of 2-Acetylpyridine-Aminoguanidine and Its Copper(II) Complexes: Crystallographic and Antimicrobial Study. Polyhedron 2016, 117, 526–534. [https://doi.org/10.1016/j.poly.2016.06.032]Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3583

Electrodeposition of Nb and Al from chloroaluminate melt on vitreous carbon

Niobium and aluminium were electrodeposited at 200 °C under argon atmosphere onto vitreous carbon from inorganic chloroaluminate melts (AlCl3+NaCl) with added niobium. Niobium was introduced into the electrolyte by anodic dissolution of metallic niobium or by chemical dissolution of Nb2O5 in a melt of equimolar AlCl3+NaCl mixture. The processes of deposition/dissolution onto/from vitreous carbon were investigated by cyclic voltammetry and chronoamperometry. Characterization of the obtained deposits was done by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The only observed reduction processes on the working electrode in the potential window from 1.000 V to – 1.000 V vs. Al, were individual niobium deposition and codeposition of niobium and aluminium with Al-Nb alloys formation. Electrodeposition of niobium from the chloroaluminate melt with added niobium (V) oxide seems to start at around – 0.100 V vs. Al and at about – 0.200 V vs. Al aluminium starts codepositing. During the codeposition Nb-Al alloys were formed. Niobium deposition starting potential from the electrolyte with niobium added by anodic dissolution starts at 0.100 V vs. Al, and aluminium codeposition starting potential was at around – 0.025 V vs. Al, followed by Nb/Al alloy formation

Alloy Formation by Electrodeposition of Niobium and Aluminium on Gold from Chloroaluminate Melts

Niobium and aluminium have been electrodeposited from inorganic chloroaluminate melts onto gold substrate at 473 K. The melts were prepared from an equimolar mixture of AlCl3+NaCl with niobium added by anodic dissolution. It was found that aluminium and niobium underpotential deposition on gold precedes overpotential deposition of niobium and subsequent aluminium deposition. Niobium was overpotentially deposited individually and co-deposited with aluminium. Applied electrochemical techniques (linear sweep voltammetry, polarization, open circuit and potential step) indicated, then physical analytical methods (scanning electron microscopy, energy dispersive spectrometry, atomic force microscopy and X-ray diffraction) confirmed formation of several niobium-aluminium, niobiumgold and aluminium- gold alloys in niobium and aluminium underpotential as well as in niobium and aluminium overpotential regions

Electrodeposition of Nb and Al from chloroaluminate melt on vitreous carbon

Niobium and aluminium were electrodeposited at 200 °C under argon atmosphere onto vitreous carbon from inorganic chloroaluminate melts (AlCl3+NaCl) with added niobium. Niobium was introduced into the electrolyte by anodic dissolution of metallic niobium or by chemical dissolution of Nb2O5 in a melt of equimolar AlCl3+NaCl mixture. The processes of deposition/dissolution onto/from vitreous carbon were investigated by cyclic voltammetry and chronoamperometry. Characterization of the obtained deposits was done by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The only observed reduction processes on the working electrode in the potential window from 1.000 V to – 1.000 V vs. Al, were individual niobium deposition and codeposition of niobium and aluminium with Al-Nb alloys formation. Electrodeposition of niobium from the chloroaluminate melt with added niobium (V) oxide seems to start at around – 0.100 V vs. Al and at about – 0.200 V vs. Al aluminium starts codepositing. During the codeposition Nb-Al alloys were formed. Niobium deposition starting potential from the electrolyte with niobium added by anodic dissolution starts at 0.100 V vs. Al, and aluminium codeposition starting potential was at around – 0.025 V vs. Al, followed by Nb/Al alloy formation

Morphometric Analysis of Nonsclerosed Glomeruli Size and Connective Tissue Content during the Aging Process

Number of sclerotic glomeruli increases during the aging process. Consequently, majority of remained nonsclerosed glomeruli become hypertrophic and some of them sclerotic, too. The aim of this study was to quantify the size and connective tissue content of nonsclerosed glomeruli and to evaluate the percentage of hypertrophic ones in examined human cases during the aging. Material was right kidney's tissue of 30 cadavers obtained during routine autopsies. Cadavers were without previously diagnosed kidney disease, diabetes, hypertension, or any other systemic disease. Tissue specimens were routinely prepared for histological and morphometric analysis. Images of the histological slices were analyzed and captured under 400x magnification with digital camera. Further they were morphometrically and statistically analyzed with ImageJ and NCSS-PASS software. Multiple and linear regression of obtained morphometric parameters showed significant increase of glomerular connective tissue area and percentage. Cluster analysis showed the presence of two types of glomeruli. Second type was characterized with significantly larger size, connective tissue content, and significantly lower cellularity, in relation to the first type. Such glomeruli might be considered as hypertrophic. First type of glomeruli was predominant in younger cases, while second type of glomeruli was predominant in cases older than 55 years

Natural Diatomite (Rudovci, Serbia) as Adsorbent for Removal Cs from Radioactive Waste Liquids

The removal of Cs (I) ions from aqueous solution was studied using natural diatomite as adsorption materials originated from Rudovci, Serbia. The microstructure of natural diatomite has been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) while the degree of Cs adsorption was evaluated by atomic emission spectroscopy. The cation exchange capacity (CEC) values for natural diatomite was 50 meq/100g. Depending on whether the Cs adsorption occurred in the acidic and alkaline media at a temperature of 298.15 K in acidic media Delta G(0) values was -12.674 kJ/mol, while in alkaline media Delta G(0) was 13.142 kJ/mol and a change of Delta S-0 to 42.51 J/molK in acidic media and 44.08 J/molK in alkaline medium