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The nuclear industry generates significant radioactive waste (RW) amounts, with its safe disposal being a primary safety and environmental issue. RW management involves solidification and disposal, often in deep underground facilities. Cement mortar is commonly used for liquid RW solidification due to its cost-effectiveness and simplicity. However, Portland cement concrete production raises environmental concerns, such as CO2 emissions and natural resource depletion. Additionally, RW storage and disposal costs drive research into low-cost matrices, especially those made from final waste products. The main requirements for matrix materials for liquid RW immobilization, which accept the role of primary barrier, are compatibility with RW material, good mechanical properties, and resistance to chemical and biological agents. However, partially substituting cement with waste materials can reduce strength and durability, increase susceptibility to cracking, porosity, and corrosion, further leading to harmful substance release. The matrix material must demonstrate longterm stability under various environmental conditions, including changes in temperature, humidity, and exposure to radiation ensuring that RW remains stable and safe within the matrix for decades or centuries. In addition, factors such as groundwater infiltration and seismic activity should also be considered when evaluating the long-term effectiveness of a protective structure. To manage these hazards, the selection, treatment, and preparation of recycled waste are crucial, alongside with proper design and utilization of such concrete. Monitoring concrete performance over time and implementing maintenance measures are necessary to ensure the long-term durability and reliability of structures. This work aims to assess the overall impact of recycled materials utilized in liquid RW solidification matrix.

Praseodymium doped calcium hydroxyapatite (PrHAP) nanopowder was synthesized by the co-precipitation method and characterized by X-Ray Diffraction, Fourier Transform Infrared, and Fluorescence Spectroscopy. Characterization studies from XRD and FTIR spectra showed that obtained crystals are monophase hydroxyapatites and that the sample particles are of nano size. A fluorescence study has shown that PrHAP particles have fluorescent emission under UV‐ Visible excitation. These results may open new avenues for developing bioactive materials for bone regeneration and fluorescent probes for bio-imaging applications.

Linden honey represents a unique honey variety valued for its nutritional benefits, distinctive taste and aroma. Phenols, polyphenols, flavonoids, ascorbic acid and phenolic acids in honey have antioxidant activities. This study aimed to investigate the effects of linden honey on the activities of antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), as well as on the concentration of malondialdehyde (MDA) in individually housed animals. The investigated parameters were quantified using spectrophotometric method for determination of enzyme activities and MDA concentration in the blood. We found that treatment with linden honey in the socially isolated animals significantly increased the enzyme activities of CAT and GPx, and significantly decreased the concentration of MDA. The modulation of CAT and GPx activities in socially isolated animals treated with linden honey may be very important for understanding the role of honey in the capacity of antioxidant defense system to increase and maintain its stability in psychosocial stress conditions. Our results may be important in biomedical research for understanding the role of honey in the amelioration of oxidative stress.

Lanthanide-doped apatite biomaterials are highly promising in medicine because of their excellent chemical and optical properties. In this study, Eu(III)-doped fluorapatite particles have been successfully synthesized by a wet method at room temperature. The characterization study from XRD showed that obtained powder is monophasic fluorapatite. Biomaterials based on fluorapatite (Ca10(PO4)5F2) doped with lanthanide elements are ideal contrast agents for a variety of biomedical applications, e.g. detection, imaging, cell tracking, and therapy [1]. Eu(III) received a great deal of interest because of several desirable properties like emission in the visible region, long luminescent lifetime, and less sensitivity to quenching by singlet oxygen [2].

The applicability of solid bricks waste in geopolymerization technique was considered. Waste samples were characterized in terms of mineralogical composition by XRD prior to mechanical testing. XRD analysis showed that both brick samples contained anorthite, wollastonite, and mullite as the main components. The compressive strength investigation was carried out by screening method with three geopolymer mixtures. Geopolymer mixtures were prepared with alkaline activators; the mixtures were poured into molds and air-dried for 28 days. The compressive strength of samples was measured according to the standard SRPS EN 12390-3:2010 for cubic samples. The compressive strength values ranged from 9.8 MPa for the newer solid brick, 10.2 MPa for the older solid brick, and 10.5 MPa for the solid brick mix waste geopolymer sample. The most likely underlying reason for the higher compressive strength results of the older solid brick and the mixed sample is their mineral composition, i.e. higher proportion of aluminosilicate. However, all samples showed satisfactory compressive strengths, and it represents an excellent basis for further research.

Gabrovnica, uranium mine near Kalna in the Eastern Serbia was a natural ore with uranium content. Exploitation of the uranium ore in this region was started in the 1960s and it was terminated in 1996. The aim of this work was to analyze radiological characterization of environmental samples around uranium mine Gabrovnica. Soil samples were taken in the autumn of 2022 and spring 2023, while surface soil samples (Gabrovnička River) were taken continuously for six month (July-December 2022 and January-June 2023). All samples were analyzed in order to determine gross alpha and gross beta activities and measured on ultra low level gas proportional counter Thermo-Eberline FHT 770T.

Gasni proporcionalni brojač koristi se za određivanje ukupne alfa i ukupne beta aktivnosti u različitim matriksima kao i za određivanje aktivnosti antropogenog radionuklida 90Sr koji je čist beta emiter. Ovaj rad predstavlja pregled kontrole kvaliteta gasnog proporcionalnog brojača Thermo-Eberline FHT 770T i određivanja efikasnosti, koja se sprovodi sa sertifikovanim standardima 241Am i 90Sr. Brojač ima mogućnost simultanog merenja na 6 detektora i određivanja aktivnosti reda mBq. U radu su prikazani i rezultati sprovedene eksterne kontrole kvaliteta učešćem u interkomparativnom merenju 90Sr, ukupne alfa i ukupne beta aktivnosti u uzorcima vode, organizovanom od strane Međunarodne Agencije za Atomsku Energiju tokom 2022. godine.

Sprovedeno istraživanje je usmereno na analizu trenda promene ukupne alfa i ukupne beta aktivnosti u poljoprivrednom zemljištu i usevima višegodišnjeg oglednog polja. Analiza je urađena primenom akreditovane metode za određivanje ukupne alfa i ukupne beta aktivnosti u čvrstim matriksima. Merenja su obavljena u Laboratoriji za zaštitu od zračenja i zaštitu životne sredine Instituta za nuklearne nauke “Vinča” na niskofonskom gasnom proporcionalnom brojaču Thermo Eberline FHT 770T. Izmerene vrednosti ukupne alfa aktivnosti variraju od 158 Bq/kg do 324 Bq/kg i ukupne beta aktivnosti od 600 Bq/kg do 1324 Bq/kg za uzorke zemljišta. Za uzorke biljnih kultura vrednosti ukupne alfa aktivnosti su u intervalu od 5 Bq/kg do 167 Bq/kg suve materije, dok su vrednosti ukupne beta aktivnosti u intervalu od 180 Bq/kg do 584 Bq/kg suve materije. Rezultati istraživanja su značajni, jer daju osnovne radiološke informacije od vitalnog značaja za ispitivano područje. Ovo je prvi pokušaj generisanja osnovnih podataka o radijacionom opterećenju zemljišta i biljnih kultura poljoprivrednog ekosistema alfa i beta emiterima, koji su određeni skrining metodom za monitoring životnog okruženja., The conducted research is focused on the analysis of the trend of changes in gross alpha and gross beta activity in agricultural soil and crops of perennial experimental fields. The analysis was performed using an accredited method for determining gross alpha and gross beta activity in solid matrix. The measurements were performed in the Radiation and Environmental Protection Department in Vinča Institute of nuclear Sciences on a low-level gas proportional counter Thermo Eberline FHT 770T. The measured values of gross alpha activity varied from 158 Bq/kg to 324 Bq/kg, and from 600 Bq/kg to 1324 Bq/kg for the gross beta activity in soil samples. For plant samples, values ranged from 5 Bq/kg to 167 Bq/kg of dry matter, and from 180 Bq/kg to 584 Bq/kg of dry matter for gross alpha and gross beta activity, respectively. The results of the research are significant, because they provide basic radiological information of vital importance for the investigated area. This is the first attempt to generate data base on the radiation load of soil and crops of the agricultural ecosystem with alpha and beta emitters, which were determined by the screening method for environmental monitoring.

Brzi napredak elektronske industrije doveo je do generisanja velike količine električnog otpada pre isteka njegovog odgovarajućeg životnog veka. Nelegalno odlaganje starih monitora i TV ekrana, odnosno njihovih katodnih cevi (Cathode-Ray Tubes, CRT), predstavlja veliki problem po životnu sredinu iz razloga što je CRT otpad klasifikovan kao opasan zbog visokog sadržaja olova. Stoga, konačnom zbrinjavanju navedenog otpada mora da prethodi tretman u topionici kako bi se olovo odvojilo od stakla. Dosadašnju praksu u Republici Srbiji (RS) dodatno komplikuje nedostatak takvih postrojenja, što zahteva izvoz CRT-a u Zapadnu Evropu uz dodatni trošak. Dosadašnja istraživanja ukazuju na mogućnost primene CRT stakla u izradi opeka, keramičkih pločica, specijalnih prostorija za odlaganje nuklearnog otpada ili kao agregata u građevinarstvu. Takođe, delimična supstitucija cementa fino mlevenim CRT staklom smanjuje količinu njegove potrošnje povećavajući nivo održivosti ovakvog procesa. Ovaj rad se bavi istraživanjima upotrebe CRT stakla u cementnim materijalima, kako bi se procenila mogućnost njegove upotrebe u malter-matriksima za imobilizaciju tečnog radioaktivnog otpada., The rapid progress of the electronic industry has led to the generation of a large amount of electrical waste before the end of its useful life. Illegal disposal of old monitors and TV screens, i.e. their Cathode-Ray Tubes (CRT), represents a major concern for the environment being CRT waste is classified as hazardous due to its high lead content. Therefore, the final disposal of this waste must be preceded by treatment in a smelter in order to separate the lead from the glass. The current practice in the Republic of Serbia (RS) is additionally complicated by the lack of such facilities, which requires the export of CRT to Western Europe at an additional cost. Previous research indicates the possibility of CRT glass utilization in the production of bricks, ceramic tiles, and special rooms for the disposal of nuclear waste or as an aggregate in construction. Also, the partial substitution of cement with fine ground CRT glass reduces the amount of its consumption, increasing the level of sustainability of this process. This paper deals with the investigation of CRT glass usage in cement materials, in order to evaluate the possibility of its use in mortar-matrix for the immobilization of liquid radioactive waste.

Malondialdehyde (MDA) is the end product of lipid peroxidation and biomarker of free radicals. The aim of this study is to investigate the effect of honey on concentrations of MDA in plasma exposed to a therapeutic dose of radiation. In this experiment animals were divided into two groups: in CONTROL group the animals were given distilled water orally for 28 days, and HONEY group consisted of animals given 1,5 ml/kg honey orally for 28 days. Blood samples of both groups were collected from a rat's tail. All blood samples were exposed to radiation of 2 Gy. Malondialdehyde concentration in plasma was determined using spectrophotometric method. Honey treatment in the blood plasma exposed to a therapeutic dose of 2 Gy significantly decreased MDA level by 30 % compared with control group. The present results indicated that honey had an effect on the levels of MDA in plasma exposed to radiation., Malondialdehid (MDA) je krajnji proizvod peroksidacije lipida i biomarker slobodnih radikala. Cilj ovog istraživanja je bio da se ispita uticaj meda na koncentraciju MDA u krvnoj plazmi izloženoj terapijskoj dozi zračenja. U ovom eksperimentu životinje su podeljene u dve grupe: u kontrolnoj grupi životinje su dobijale destilovanu vodu oralno tokom 28 dana, a drugu grupu činile su životinje koje su tokom 28 dana dobijale oralno 1.5 ml/kg meda. Uzorci krvi obe grupe su sakupljeni iz repa pacova. Svi uzorci krvi bili su izloženi zračenju od 2 Gy. Koncentracija MDA u plazmi određena je spektrofotometrijskom metodom. Tretman medom u krvnoj plazmi izložen terapijskoj dozi od 2 Gy značajno je smanjio nivo MDA (30 %) u poređenju sa kontrolnom grupom.

Nanomaterials based on metal–doped fluorapatite (FAP) have attracted considerable interest as potential next–generation antimicrobial agents. In this study, Cu2+–doped FAP nanocrystals have been successfully synthesized by a neutralization method at room temperature. Their structural, optical, antimicrobial, and hemcompatible properties have been investigated. XRD, FTIR, FESEM, and N2 adsorption–desorption studies indicate the formation of single–phase FAP mesoporous nanopowders, composed of rod–like particles. TEM images confirmed the formation of nanorodes with a length of 60 nm and a width of about 18 nm. Rietveld analysis shows that the Cu2+ ions preferentially substitute Ca2 (6 h) sites in the hexagonal fluorapatite crystal structure. Fluorescence spectroscopy accompanied by MCR–ALS method confirms substitution of Cu2+ ions in FAP crystal lattice with extracting additional d–d band transition at green color from FAP broadband self–activated luminescence in violet–blue color. Antimicrobial studies conducted on Staphylococcus aureus, Escherichia coli and Micrococcus lysodeikticus showed that FAP nanopowder with the highest Cu2+ content have strong bacteriostatic action on Staphylococcus aureus bacterial strain in mediums containing nutrition matters. In addition, this sample in comparison to pure FAP achieved a high percentage of relative reduction of bacterial population for all three species, being >90% in most cases. Fungistatic action is noticed too, throwgh the slowing down mycelium growth of fungus Aspergillus niger, Aspergillus flavus and Penicillium roqueforti and reduction of sporulation of Aspergillus niger species. Cu2+–doped FAP nanocrystals shows a synergistic antimicrobial effect with Cu2+ and F− ions. Concerning the potential biomedical applications, the hemolysis ratios of the Cu2+–doped FAP samples were below 5%. The obtained results pointed out the possible use of the synthesized nanocrystals as broad–spectrum antimicrobial agents for various

In vitro cytotoxic evaluation, formation constants and thermal stability of four mixed-ligand Co(II) complexes with tpmc = N,N',N",N'"-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane and carboxylate/dicarboxylate co-ligands of formulas [Co2(benz)2tpmc](ClO4)2•3H2O (1), benz– = benzoate anion; [Co2(L)tpmc](ClO4)2•nH2O, L = pht2– (phthalate dianion), n=2 (2), L = ipht2– (isophthalate dianion), n=4 (3) and L = tpht2–(terephthalate dianion), n=4 (4) are reported. The stoichiometric composition of the compounds in the solution were determined spectrophotometrically using Job's methods. Formation constants, K and Gibbs free energy, ΔG values were calculated. The thermal behavior of the complexes was investigated by simultaneous TG/DSC and TG – MS measurements. The cytotoxic effect of the complexes, the free ligands, the DMSO solvent and cis-platin, as referent cytostatic drug, was evaluated on Human cervix adenocarcinoma (HeLa), human melanoma (Fem-x) and human colon carcinoma (LS174) cell lines. The IC50 values were between 12.7–42.3 μM. The first crystal structure determination of the Co(II) complex [Co2(µ-pht)tpmc](ClO4)2•H2O with boat conformation of tpmc ligand, was also done. The complex crystallizes in monoclinic crystal system, C2/c space group. The geometries around both Co(II) atoms are highly distorted octahedral. The Co(II) ions exhibit CoN4O2 coordination environments with the four nitrogen donor atoms of the tpmc ligand and two oxygen atoms belonging to the one carboxylate group of pht2− ligand. The carboxylate groups of pht2− are coordinated in an endo-bidentate mode. The tpmc ligand adopted a boat conformation in which the two coordinated Co(II) atoms are located on the same side of the ring, with Co•••Co distance amounting 5.4799(5) Å. © 2021

In vitro cytotoxic evaluation, formation constants and thermal stability of four mixed-ligand Co(II) complexes with tpmc = N,N',N",N'"-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane and carboxylate/dicarboxylate co-ligands of formulas [Co2(benz)2tpmc](ClO4)2•3H2O (1), benz– = benzoate anion; [Co2(L)tpmc](ClO4)2•nH2O, L = pht2– (phthalate dianion), n=2 (2), L = ipht2– (isophthalate dianion), n=4 (3) and L = tpht2–(terephthalate dianion), n=4 (4) are reported. The stoichiometric composition of the compounds in the solution were determined spectrophotometrically using Job's methods. Formation constants, K and Gibbs free energy, ΔG values were calculated. The thermal behavior of the complexes was investigated by simultaneous TG/DSC and TG – MS measurements. The cytotoxic effect of the complexes, the free ligands, the DMSO solvent and cis-platin, as referent cytostatic drug, was evaluated on Human cervix adenocarcinoma (HeLa), human melanoma (Fem-x) and human colon carcinoma (LS174) cell lines. The IC50 values were between 12.7–42.3 μM. The first crystal structure determination of the Co(II) complex [Co2(µ-pht)tpmc](ClO4)2•H2O with boat conformation of tpmc ligand, was also done. The complex crystallizes in monoclinic crystal system, C2/c space group. The geometries around both Co(II) atoms are highly distorted octahedral. The Co(II) ions exhibit CoN4O2 coordination environments with the four nitrogen donor atoms of the tpmc ligand and two oxygen atoms belonging to the one carboxylate group of pht2− ligand. The carboxylate groups of pht2− are coordinated in an endo-bidentate mode. The tpmc ligand adopted a boat conformation in which the two coordinated Co(II) atoms are located on the same side of the ring, with Co•••Co distance amounting 5.4799(5) Å.

Coupled substitution of fluorapatite (FAP) crystal lattice plays an important role in the engineering of optically active nanomaterials. Uniform fluorapatite nanopowders doped with praseodymium (Pr3+) and carbonate (CO32−) ions have been successfully synthesized by precipitation method under room temperature (25 °C). The structural, morphological, chemical and optical properties of monophase material were characterized by X-ray diffraction (XRD), Fourier Transform Infrared and Far Infrared Spectroscopy (FTIR and FIR, respectively), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), Transmission Electron Microscopy (TEM) and Photoluminescence Spectroscopy (PL). Coupled substitution of FAP crystal lattice with Pr3+ and CO32− reduces the crystallite size with a constant c/a ratio of 1.72. FTIR study showed that synthesized nanopowders were AB-type CO32− substitution, and FIR study revealed new Pr–O vibrations. TEM analysis was found that synthesized nanopowders were composed of irregular spheres in the nanometer range. The fluorescence of FAP nanoparticles was in the violet-blue region of the visible part of the spectrum. When Pr3+ was doped in a lattice, the violet-blue emission becomes sharper due to reabsorption. MCR–ALS analyses of fluorescence spectra indicated the shift of the maximum to the blue color with the increase in the concentration of Pr3+ ions. Additionally, luminescent nanopowders demonstrated significant antibacterial activity against Escherichia coli. As the obtained nanoparticles showed a good absorption of ultraviolet A light and reabsorption of blue-green luminescence, they are suitable for further development of optically active nanomaterials for light filtering. Optically active PrCFAP nanopowders with antibacterial properties may be promising additives for the development of multifunctional cosmetic and health care products.

The aim of the study was to assess Cs+ ions transport phenomena from solidified spent ion exchange resin by mathematical modeling. The experimental results comparison was obtained by Hespe's Standard Leaching Method. For the leaching prediction rate as a function of time, diffusion and semi-empirical models were used. Due to the presence of spent ion exchange resin, the cement matrix absorbed a larger amount of water, swelled, and degraded. This phenomenon caused a significantly lower value of mechanical resistance to pressure. Also, through the increase of bentonite and zeolite content, the cement matrix decreased its mechanical resistance. The retention of cesium ions in the cement matrix was low and they were leached during the early phase of the investigation. The diffusion coefficient, De, decreased by three orders of magnitude with the addition of zeolite and bentonite in the cement matrix. Linear regression of experimental Cs+ leaching results, under static conditions, displayed that the semi-empirical parameter K3 than the absolute values of the parameters K2 and K1. Therefore, the contribution of matrix dissolution to the total radionuclides transport was irrelevant to the prevailing share of diffusion and surface washing processes.

U radu su prikazani rezultati određivanja koncentracije proizvedenih radionuklida 90Sr i 137Cs u rečnom sedimentu reke Dunav u Beogradu u 2020. godini. Rezultati su dobijeni u okviru sistematskog ispitivanja nivoa radioaktivnosti u životnoj sredini na teritoriji Beograda. Za analizu sadržaja 90Sr primenjena je radiohemijska metoda, dok je određivanje sadržaja 137Cs urađeno gamaspektrometrijskom analizom. Dobijene vrednosti proizvedenih radionuklida u rečnom sedimentu ne predstavljaju rizik po životnu sredinu, The paper presents the results of activity concentrations of 90Sr and 137Cs in the river sediment of the Danube in Belgrade for 2020. The results were obtained as part of a systematic examination of the radioactivity level in the environment in Belgrade. For determination of 90Sr content, radiochemical method was used, while determination of 137Cs content was done by gamma spectrometric analysis. The obtained values of artificial radionuclides in Danube river sediment do not pose a risk to the environment.

Coupled substitution of fluorapatite (FAP) crystal lattice plays an important role in the engineering of optically active nanomaterials. Uniform fluorapatite nanopowders doped with praseodymium (Pr3+) and carbonate (CO32-) ions have been successfully synthesized by precipitation method under room temperature (25 degrees C). The structural, morphological, chemical and optical properties of monophase material were characterized by X-ray diffraction (XRD), Fourier Transform Infrared and Far Infrared Spectroscopy (FTIR and FIR, respectively), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), Transmission Electron Microscopy (TEM) and Photoluminescence Spectroscopy (PL). Coupled substitution of FAP crystal lattice with Pr3+ and CO32- reduces the crystallite size with a constant c/a ratio of 1.72. FTIR study showed that synthesized nanopowders were AB-type CO32- substitution, and FIR study revealed new Pr-O vibrations. TEM analysis was found that synthesized nanopowders were composed of irregular spheres in the nanometer range. The fluorescence of FAP nanoparticles was in the violet-blue region of the visible part of the spectrum. When Pr3+ was doped in a lattice, the violet-blue emission becomes sharper due to reabsorption. MCR-ALS analyses of fluorescence spectra indicated the shift of the maximum to the blue color with the increase in the concentration of Pr3+ ions. Additionally, luminescent nanopowders demonstrated significant antibacterial activity against Escherichia coli. As the obtained nanoparticles showed a good absorption of ultraviolet A light and reabsorption of blue-green luminescence, they are suitable for further development of optically active nanomaterials for light filtering. Optically active PrCFAP nanopowders with antibacterial properties may be promising additives for the development of multifunctional cosmetic and health care products.

Positive matrix factorization (PMF) is a dimension reduction method used to model the covariance structures of observable variables in order to impel a smaller number of latent nonnegative factors. It resolves receptor modeling problem, which is based on the chemical mass balance equation (CMB) and may discover hidden patterns in the environmental data, where each extracted factor is accompanied by an actual source of emission. In this paper, PMF source apportionment analyses of fine aerosol fraction (PM2.5 mode) at Belgrade suburban background site, in 2016/17 year, have been performed by processing a data set of 130 PM2.5 mass concentrations and twenty-one elemental concentrations and soot concentrations in each PM2.5 sample (mode). The PM2.5 mass concentrations in collected samples have been determined following SRPS EN 12341:201 procedure, elemental concentrations were obtained by PIXE alanytical technique in the frame of the regional IAEA project, in the Institute of Nuclear Research, Hungarian Academy of Sciences, and soot concentrations were analyzed by smoke stain reflectometry in accordance with ISO 9835:1993 (E). The EPA PMF program ver 5.0, was used to solve the PMF model. Since the determination of an optimal PMF solution is a strongly heuristic procedure, there is a necessity of finding a more quantitative ways to reduce the arbitrariness of this technique. In order to reduce the range of possible solutions, we have analyzed how the values of model parameters changes as a function of the number of factors. PMF modeling was performed in a robust mode. For the purpose of finding the best fit solution wich minimize the object function Q, we varied the number of factors in the range from 4 to 8. Additionally, influence of rotations are also analyzed in iterative steps by varying FPEAK function in the range -1 to +1 with an increment of 0.5. Obtained results indicated significant role of Q/Qexp ratio analysis for optimal solution choice. In optimization proc

Besides the evident harmful impact to human health, black carbon (BC) is considered as second important contributor to climate change due to its sunlight absorption and warming effects. It is a major component of fine atmospheric particulate matter emitted during the incomplete combustion of fossil fuels and biomass burning emissions from both natural and anthropogenic sources. Atmospheric carbon was recognized in forms of soot, black carbon, elemental carbon, inorganic carbon, organic carbon, brown carbon, etc, depending on the origin and absorption characteristics. Measurement methodologies for BC analysis in aerosol samples are mostly based on optical and thermal properties of carbon species. Here are presented results of the application of the optical analytical technique which relies on the multi-wavelenght light attenuation by black carbon component of fine particulate matter deposited on filter media. For that purpose, standard polytetrafluoroethylene (PTFE), quartz and carbon nanotube filters with different qualitative features and pore diameters were exposed to fine aerosol fraction at urban background monitoring site in heating and non heating seasons, using low-volume air samplers with 2.3 m3/h air flow. A multi wavelength absorption black carbon instrument (MABI) with 405 nm, 465 nm, 525 nm, 639 nm, 870 nm, 940 nm and 1050 nm LEDs was used for blank and exposed filters analysis and black carbon evaluation. Differences in obtained BC values are discussed in relation to various absorption potential of different filter media, taking into account absorption coefficients dependence on the wavelength and density. Main advantage of this method is simplicity and complementarity with nondestructive nuclear analytical techniques (EDXRF, PIXE) for elemental analysis of fine aerosol fraction on specific filter media. Differentiation between black carbon coming from fossil fuels combustion and from biomass burning sources would be additional information valuable for

Luminescentni nanokristali (nanofosfori) na bazi fluorapatita (FAP-a) dopirani elementima retkih zemalja idealni su kontrastni agenti za bio-medicinske primene, kao što su detekcije, snimanja, praćenja i terapije ćelija kancera. Kancer je jedna od najčešćih bolesti modernog doba čiji uspeh lečenja zavisi od rane dijagnostike i neinvazivnog tretmana. Luminescentne nanočestice mogu uneti inovativnu paradigmu u lečenje kancera kombinovanjem biosnimanja, dijagnostike i tretmana. Za studije fluorescentnih biosnimanja nanokristali fluorapatita dopirani retkim zemljama kao kontrastni agenti pružaju značajne prednosti u vidu velikih kontrasta i dugotrajnosti luminescencije, i što je još važnije visoke biokompatibilnosti, netoksičnosti i bioaktivnosti. Glavni ciljevi ove doktorske disertacije su sinteza novih luminescentnih multifotonskih bionanomaterijala na bazi fluorapatita dopiranih jonima prazeodimijuma (Pr3+), njihova karakterizacija i evaluacija primene za fluorescentna biosnimanja kancera. Sintezom nanoprahova u umerenim uslovima metodom ko-precipitacije, a potom sušenjem na 110 oC i kalcinacijom na temperaturama od 700 i 1000 oC očekuje se pronalaženje najboljih uslova za dobijanje novih nanofosfora koji bi našli i različite bio-medicinske primene u oblasti fluorescentnih biosnimanja. Proučavane su tri vrste PrFAP nanokristala, sa 0,1%, 0,5% i 1% atomskih procenta Pr3+, zajedno sa nedopiranim FAP kontrolnim uzorkom. Nivoi energije aktivator jona Pr3+ sadrže metastabilna multipletna stanja koja nude mogućnosti efikasnih emisionih linija u više boja u FAP nanokristalima, kao i u infracrvenoj i ultravioletnoj oblasti spektra. Metodom ko-precipitacije na sobnoj temperaturi (25 oC), a potom sušenjem na 110 oC, sintetisani su monofazni heksagonalni nanokristali PrFAPs nepravilnog sfernog oblika. Termičkom analizom sintetisanih uzoraka, na osnovu detektovanih temperaturnih opsega procesa dekarbonacije i dehidroksilacije, utvrđene su temperature kalcinacije od 700, Luminescent nanocrystals (nanophosphorus) based on fluorapatite (FAP) doped with rare earth elements are ideal contrast agents for biomedical applications such as cancer cell detection, imaging, tracking and therapy. Cancer is one of the most common diseases of the modern times whose success of the cure depends on early diagnosis and non-invasive treatment. Luminescent nanoparticles can bring an innovative paradigm into the treatment of cancer by combining bioimaging, diagnostics and treatment. Rare earth doped fluorapatite nanocrystals as contrast agents for studies of fluorescence bioimaging, offer significant advantages in terms of high contrasts and long-term luminescence, and more importantly high biocompatibility, non-toxicity and bioactivity. The main objectives of this doctoral dissertation are the synthesis of novel luminescent multiphoton bionanomaterials based on fluorapatites doped with praseodymium ions (Pr3+), their characterization and evaluation of their application for cancer fluorescence bioimaging. Synthesis of nanopowders under moderate conditions by the co-precipitation method, followed by dried at 110 °C and calcination at 700 and 1000 °C, is expected to find the best conditions for obtaining new nanophosphors that would find different bio- medical applications in the field of fluorescence bioimaging. Three types of PrFAP nanocrystals were studied, with 0,1%, 0,5%, and 1% atomic percentages of Pr3+, together with an undoped FAP control sample. Energy levels of the Pr3+ ion activator contain metastable multiplet states that offer the possibility of efficient multi-color emission lines in FAP nanocrystals as well as in the infrared and ultraviolet regions of the spectrum. Single-phase hexagonal nanocrystals PrFAPs of irregular spherical shape were synthesized by the method of co-precipitation at room temperature (25 oC) and then drying at 110 oC. Thermal analysis of the synthesized samples, based on the detected temperature ranges of the decarbon

Fluorapatite doped with rare-earth elements has a wide-range of biomedical applications. Here, a new type of fluorapatite nanocrystals doped with praseodymium (FAP-Pr) with excitation-emission profiles in visible part of the spectrum is fabricated. Energy levels of Pr3+ activator ion contain metastable multiples states that offer the possibility of efficient multicolor emission lines in FAP nanocrystals. Three types of FAP-Pr nanocrystals with 0.1%, 0.5% and 1% atomic percent of Pr3+ (along with the undoped FAP control sample) are studied. Their novel chemical production method is described, the FAP-Pr nanocrystals structure, biocompatibility and the suitability for cell imaging are analyzed. Physicochemical characterization confirms crystals down to nanometer size. In addition, quantum-chemical calculation predicts that Pr3+ ions are incorporated into the FAP crystal lattice at Ca2 (6 h) sites. In vitro viability results shows that FAP-Pr nanocrystals are nontoxic to live cells. Additionally, the cell uptake of the FAP-Pr nanocrystals is studied using fluorescence-based widefield and confocal microscopy. The nanocrystals show characteristic green emission at 545 nm (P-3(0)-> H-3(5) transition of Pr3+ ion) and orange emission at 600 nm (D-1(2)-> H-3(4)), which we use to discriminate from cell autofluorescence background. Orthogonal projections across 3D confocal stacks show that the nanocrystals are able to enter the cells positioning themselves within the cytoplasm. Overall, the new FAP-Pr nanocrystals are biocompatible and of the tested types, the 0.5% Pr3+ doped nanocrystals show the highest promise as a tracking nanoparticle probe for bioimaging applications.