Silver/poly(N-vinyl-2-pyrrolidone) and silver/alginate nanocomposites obtained by electrochemical procedures.

Cilj ove doktorske disertacije je elektrohemijsko dobijanje i karakterizacija nanokompozitnih sistema srebro/poli(N-vinil-2-pirolidon) (Ag/PVP), i srebro/alginat (Ag/alginat), u obliku koloidnih disperzija i hidrogelova, za biomedicinsku primenu. Elektrohemijska sinteza, u odnosu na hemijsku, pokazuje prednost u dobijanju malih čestica metala visoke čistoće, i to sa manjim brojem hemikalija, što je od izuzetnog značaja za primenu u biomedicini. Takođe, elektrohemijska sinteza daje mogućnost precizne kontrole veličine nanočestica, podešavanjem vrednosti gustine struje ili potencijala. Izvršena je optimizacija elektrohemijske sinteze nanočestica srebra u rastvorima PVP i alginata. Dobijene Ag/PVP i Ag/alginatne koloidne disperzije su karakterisane različitim fizičko-hemijskim metodama radi izbora najefikasnijeg režima i uslova sinteze. U cilju dobijanja što veće koncentracije nanočestica, sfernog oblika, ispitan je uticaj potencijala, gustine struje, vremena implementacije, sastava rastvora za sintezu. Sastav, morfologija i struktura nanokompozitnih sistema su ispitani UV-vidljivom spektroskopijom, optičkom, transmisionom i skenirajućom elektronskom mikroskopijom, cikličnom voltametrijom, spektroskopijom infracrvene svetlosti sa Furijeovom (Fourier) transformacijom (FT-IR). Elektrohemijska sinteza nanočestica srebra u rastvoru PVP je vršena u galvanostatskim i potenciostatskim uslovima, kao i primenom reversne struje. Utvrđeno je da galvanostatska sinteza obezbeđuje veću koncentraciju dobijenih nanočestica, koja raste sa povećanjem primenjene gustine struje. Najveća koncentracija nanočestica srebra dobijena je galvanostatskom sintezom, gustinom struje od 62 mA cm-2, tokom 10 min. Veličina dobijenih nanočestica je oko 75 nm. FT-IR spektroskopijom je utvrđeno da se interakcija između molekula PVP i nanočestica srebra dešava ili na atomu azota ili na atomu kiseonika u pirolidonskom prstenu (u zavisnosti od veličine nanočestica) koordinacionim vezama sa nanočesticama srebra. Dobijeni rezultati ukazuju na vezivanje molekula PVP sa Ag nanočesticama, što potvrđuje...The objective of this doctoral dissertation is the electrochemical synthesis and characterization of silver/poly(N-vinyl-2-pyrrolidone) (Ag/PVP), and silver/alginate (Ag/alginate), nanocomposite systems, in forms of colloid dispersions and hydrogels, for biomedical purposes. The electrochemical synthesis, in comparison with the chemical, exhibits the advantages in obtaining of small metal nanoparticles of high purity, using smaller number of chemicals. This becomes of a great importance in biomedical applications. Electrochemical synthesis also gives a possibility of a precise particle size control, by the adjustment of the applied current density or potential. The optimization of the electrochemical synthesis of silver nanoparticles in PVP and alginate solutions was performed. As obtained Ag/PVP and Ag/alginate colloid dispersions were characterized by various physico-chemical methods in order to find the most efficacious regime and conditions of the synthesis. Aiming the highest possible nanopartcle concentration, the influence of the applied potential, current density, implementation time and the synthesis solution composition were examined. The composition, morphology and the structure of nanocomposite systems were investigated by UV-visible spectroscopy, optic, transmission and scanning electron microscopy, cyclic voltammetry and Fourier transform infrared spectroscopy (FT-IR). The electrochemical synthesis of silver nanoparticles inside PVP solution was performed in galvanostatic and potentiostatic conditions, as well as by using a reverse current. It is determined that the galvanostatic synthesis provides higher concentration of the obtained silver nanoparticles, increasing with the increase of the applied current density. So, the highest concentration of silver nanoparticles is obtained galvanostatically, at the applied current density of 62 mA cm-2, during 10 min. The size of the obtained silver nanoparticles was ~75 nm. FT-IR spectroscopy results showed the interaction between PVP..

Softveri za glazbenu tehnologiju u usvajanju nastavnih sadržaja na satovima glazbene kulture

The paper examines the use of music technology software in music classes among younger pupils.  The sample consists of the fourth grade primary school pupils (E-65, C-64) from Serbia.  The experiment was carried out in classes in which pupils\u27 intellectual processes (learning, attention, and memory) were encouraged through the use of music technology software. While the E group achieved better results regarding all examined parameters, a decline was recorded in the C group regarding some parameters.  The results of this research also provide a basis for further research which would be aimed at pupils of all age groups.   Keywords: music via technology, educational software, pupils\u27 achievementU radu se istražuje korištenje softvera za glazbenu tehnologiju u usvajanju nastavnih sadržaja i realizaciji nastave glazbene kulture. Uzorak se sastoji od 129 učenika četvrtog razreda osnovne škole podijeljenih u dvije skupine, eksperimentalni (E-65 učenici) i kontrolni (K-64 učenici). Eksperiment se temelji na konceptu nastave u kojoj se učenici potiču na poticanje intelektualnih procesa (učenje, pažnja, pamćenje) korištenjem glazbene tehnologije. Rezultati ove studije pokazuju da postoji značajna razlika između dviju skupina u pogledu razine usvojenog sadržaja. Ovaj je rad temelj daljnjih istraživanja koja bi bila usmjerena na učenike svih uzrasta, kao korisnike novih tehnologija u nastavi glazbene kulture

Reconstruction of the mandible with an autogenous corticocancellous bone graft and fibrin glue: An animal experiment

This paper reports on an experimental animal study evaluating a method of mandibular reconstruction in dogs using autogenous corticocaneclous bone graft and fibrin glue. Eight animals underwent a resection at the mandibular body and primary reconstruction was carried out using osteosynthesis plates and screws. The defect was bridged with an autogenous particulate bone graft from the anterior iliac crest. To accelerate bone healing, fibrin glue (FG) was mixed with particulate bone graft. The hypothesis of this study was based on the presumption that bone healing, in segmental reconstruction of the dog mandible with a particulate cancellous bone graft mixed with FG, would be successful. All dogs had eventful healing. The histological results were less favorable with regard to bone remodeling than the results obtained in similar experiments with a particulate corticocancellous bone graft

Određivanje koncentracija metamizol-natrijuma u inflamiranim zglobovima svinja posle intravenske i elektroforetske aplikacije

Concentrations of the NSAID metamizol sodium (MmNa) in the synovial fluid and hyaline cartilage of inflamed knee and elbow joints of pigs after i.v. application and iontophoresis (IPh) were investigated. The research was conducted on 14 male pigs divided equally into two experimental groups and exposed to artificial inflammation of knees and elbows prior to the application of MmNa. The first group (A) was administered 2.5 g (twice the maximum therapeutic dose) MmNa intravenously, whilst the second group (B) was exposed to the same dose, but applied by IPh into contralateral knee and elbow joints. Four hours after the application of MmNa biopsies of the affected knee and elbow joints were performed. The average concentration of MmNa in the synovial fluid of inflamed joints in group A was 9.81±1.96μg/g, while in group B was 170.66±2.07 μg/g, being 17 times higher. The average concentration of MmNa in the hyaline cartilage was 2.29±1.16μg/g following i.v. administration and 98.36±21.58μg/g after IPh, i.e. approximatelly 43 times higher. This led to the conclusion that IPh of MmNa, resulting in incomparably higher concentrations in inflamed joints without any adverse systemic effects, has an advantage over i.v. application.U sinovijalnoj tečnosti i hijalinoj hrskavici inflamiranog kolenog i lakatnog zgloba svinja određivane su koncentracije metamizol-natrijuma (MmNa) aplikovanog i.v. i putem elektroforeze. Arteficijelno zapaljenje kolena i lakta prasadi izazvano je terpentinskim uljem. Metamizol-natrijum je primenjen u dozi od 2.5 g u prvoj grupi prasadi intravenski, a u drugoj putem elektroforeze u kontalateralni koleni i lakatni zglob. Četiri sata posle aplikacije MmNa urađena je biopsija tretiranih zglobova. Prosečna koncentracija MmNa u sinovijalnoj tečnosti inflamiranih zglobova prasadi posle i.v. aplikacije iznosila je 9,81±1,96μg/g, a posle elektroforeze bila je 170,66±2,07μg/g tkiva, odnosno oko 17 puta viša. Izmerena prosečna koncentracija MmNa u hijalinoj hrskavici iznosila je 2,29±1,16μg/g posle i.v. aplikacije i 98,36±21,58μg/g posle aplikacije elektroforezom, odnosno oko 43 puta više. Zaključujeno je da MmNa primenjen elektroforezom postiže statistički veoma značajno više prosečne koncentracije u inflamiranim zglobovima u odnosu na i.v. aplikaciju. Primena MmNa elektroforezom ima značajnu prednost nad i.v. aplikacijom ovog leka ne samo zbog postizanja značajno viših koncentracija u inflamiranim zglobovima, već i zbog izostajanja sistemskih neželjenih reakcija

Ekstremno visoke vrednosti specifične aktivnosti berilijuma-7 u prizemnom sloju atmosfere u Evropi

Seasonal and spatial patterns of extremely high beryllium-7 surface concentration recorded over the 2001-2010 period across Europe are investigated. The beryllium-7 measurements for 14 sites are taken from the Radioactivity Environmental Monitoring Database. The maxima and minima in the annual cycle of the beryllium-7 surface concentration occur later in the year as the latitude of the measurement site decreases. Extremely high beryllium-7 surface concentrations are defined here as values greater than the 95th percentile in each measurement site. Most of the extremes occur over the March-August period. At least 10 % of the total number of extremes appear during autumn and winter, with an exception of Vienna, where all the extremes took place during spring and summer. The regional spread of extremes common to pairs of measurement sites points to an existence of three distinct regions in Europe: north of 55°N, between 45°N and 55°N, and south of 45°N. Although the beryllium-7 concentration records are significantly correlated across all the investigated sites, the strongest correlations are found within the identified regions.Sezonska i prostorna raspodela ekstremno visokih specifičnih aktivnosti berilijuma-7 u prizemnom sloju atmosfere analizirane su u ovom radu. Merenja tokom 2001-2010. godine na 14 evropskih stanica preuzeta su iz REMdb-baze podataka Monitoring radioaktivnosti u životnoj sredini. Prvo su razmotreni godišnji ciklusi specifične aktivnosti berilijuma-7 koji pokazuju da se godišnje maksimalne i minimalne srednje mesečne vrednosti pomeraju ka kasnijim mesecima kako se smanjuje geografska širina merne stanice. Za ekstremno visoke vrednosti specifične aktivnosti berilijuma-7 uzete su vrednosti veće od 95-og percentila, koji je izračunat za svaku stanicu posebno. Najveći broj ovih ekstrema događa se od marta do avgusta, a najmanje 10 % od ukupnog broja ekstrema tokom jeseni i zime. Izuzetak je merna stanica Beč na kojoj su se svi ekstremi dogodili tokom proleća i leta. Rasprostranjenost ekstrema koji su zajednički za parove mernih mesta, ukazuje da postoje tri različita regiona u Evropi: severno od 55°N, između 45°N i 55°N, i južno od 45°N. Iako su merenja specifične aktivnosti berilijuma-7 značajno korelisana za sve analizirane stanice, najveći koeficijenti korelacije dobijeni su u okviru ovih regiona

Uticaj odgajivačkog područja i godine na osobine mlečnosti bikovskih majki simentalske rase

Cows which represent top of the genetic value of the population in regard to their traits are chosen for bull dams. Selection is based on origin, production performance (quantity of milk, milk fat and protein content), milking/dairy traits, reproductive indicators, exterior and linear type scores. This study included 292 cows of Simmental breed selected for bull dams on the territory of Republic of Serbia during one year. Selection of cows for herd of bull dams was done after finalized first and subsequent lactation. In this study, the effect of region and year of calving on milk traits is presented. Applying the method of least squares average value of milk production was obtained - 5.754,49 kg, milk fat content - 3,98% and quantity of milk fat - 230,24 kg. Regions had statistically highly significant effect (P (lt) 0,01) on all investigated milk traits. Year of calving showed no statistically significant effect on milk yield, yield of milk fat and content of milk fat (P>0,05).Za bikovske majke se odabiraju krave koje prema osobinama predstavljaju vrh genetske vrednosti populacije. Izbor se vrši na osnovu porekla, proizvodnih osobina (količina mleka, sadržaj mlečne masti i proteina), muznih osobina, reproduktivnih pokazatelja, eksterijera i linearnih ocena tipa. Ovim istraživanjem je obuhvaćeno 292 krave simentalske rase odabrane za bikovske majke na području Republike Srbije u toku godine. Odabiranje krava u zapat bikovskih majki izvršeno je posle završene prve, odnosno na osnovu sledećih laktacija. U radu je ispitan uticaj odgajivačkog područja i godine telenja na osobine mlečnosti. Koristeći metod najmanjih kvadrata dobijene su prosečne vrednosti proizvodnje mleka 5.754,49 kg, sadržaja mlečne masti 3,98% i količine mlečne masti 230,24 kg. Regioni su imali statistički visoko značajan uticaj (P (lt) 0,01) na sve ispitivane osobine mlečnosti. Na osobine prinosa mleka, mlečne masti i sadržaja mlečne masti, godina telenja nije ispoljila statistički značajan uticaj (P>0,05)

Spectroscopic investigation of milo milunović’s canvas painting “the inspiration of the poet”

A canvas painting by Milo Milunović “The Inspiration of the poet” was investigated in this work by multianalitical approach in order to identify pigments used by the artist as well as his painting technique. Results obtained by optical microscopy, fluorescence photography under UV light, energy dispersive X-Ray fluorescence (EDXRF) and FTIR Spectroscopy revealed following pigments on the painting: lead white, zinc white, cobalt blue, red pigment vermilion, green pigment viridian, as well as several earth colours. Optical micrographs show regions with no separation between layers, indicating that these areas were painted wet paint over wet paint

Supplementary data for article: Marković, V.; Janićijević, A.; Stanojković, T.; Kolundzija, B.; Sladić, D.; Vujčić, M.; Janović, B.; Joksović, L.; Djurdjevic, P. T.; Todorović, N.; et al. Synthesis, Cytotoxic Activity and DNA-Interaction Studies of Novel Anthraquinone-Thiosemicarbazones with Tautomerizable Methylene Group. European Journal of Medicinal Chemistry 2013, 64, 228–238. https://doi.org/10.1016/j.ejmech.2013.03.071

Supplementary material for: [https://doi.org/10.1016/j.ejmech.2013.03.071]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1370