Influence of magnetic field on the reduction of 4,8-diaza-3,6,6,9-tetramethyl undecane-3,8-diene2,10-dione dioxime

The influence of the magnetic field with the magnetic induction up to 1,35T on the reduction of 4,8-diaza-3,6,6,9-tetramethylundecane-3,8-diene-2,10-dione dioxime (DI) in anhydrous protic solvents (anhydrous ethanol and 2-propanol) was defined. As the reductants NaBH4 and KBH4 were usedPhysical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Hydrothermally processed 1D hydroxyapatite: Mechanism of formation and biocompatibility studies

Recent developments in bone tissue engineering have led to an increased interest in one-dimensional (1D) hydroxyapatite (HA) nano- and micro-structures such as wires, ribbons and tubes. They have been proposed for use as cell substrates, reinforcing phases in composites and carriers for biologically active substances. Here we demonstrate the synthesis of 1D HA structures using an optimized, urea-assisted, high-yield hydrothermal batch process. The one-pot process, yielding HA structures composed of bundles of ribbons and wires, was typified by the simultaneous occurrence of a multitude of intermediate reactions, failing to meet the uniformity criteria over particle morphology and size. To overcome these issues, the preparation procedure was divided to two stages: dicalcium phosphate platelets synthesized in the first step were used as a precursor for the synthesis of 1D HA in the second stage. Despite the elongated particle morphologies, both the precursor and the final product exhibited excellent biocompatibility and caused no reduction of viability when tested against osteoblastic MC3T3-E1 cells in 2D culture up to the concentration of 2.6 mg/cm2. X-ray powder diffraction combined with a range of electron microscopies and laser diffraction analyses was used to elucidate the formation mechanism and the microstructure of the final particles. The two-step synthesis involved a more direct transformation of DCP to 1D HA with the average diameter of 37 nm and the aspect ratio exceeding 100:1. The comparison of crystalline domain sizes along different crystallographic directions showed no signs of significant anisotropy, while indicating that individual nanowires are ordered in bundles in the b crystallographic direction of the P63/m space group of HA. Intermediate processes, e.g., dehydration of dicalcium phosphate, are critical for the formation of 1D HA alongside other key aspects of this phase transformation, it must be investigated in more detail in the continuous design of smart HA micro- and nano-structures with advanced therapeutic potentials.This is the peer-reviewed version of the articleStojanović, Z.S., Ignjatović, N., Wu, V., Žunič, V., Veselinović, L., Škapin, S., Miljković, M., Uskoković, V., Uskoković, D., 2016. Hydrothermally processed 1D hydroxyapatite: Mechanism of formation and biocompatibility studies. Materials Science and Engineering: C 68, 746–757. [https://doi.org/10.1016/j.msec.2016.06.047]Published version: [https://vinar.vin.bg.ac.rs/handle/123456789/7576

Rare-earth (Gd3+,Yb3+/Tm3+, Eu3+) co-doped hydroxyapatite as magnetic, up-conversion and down-conversion materials for multimodal imaging

Taking advantage of the flexibility of the apatite structure, nano- and micro-particles of hydroxyapatite (HAp) were doped with different combinations of rare earth ions (RE3+ = Gd, Eu, Yb, Tm) to achieve a synergy among their magnetic and optical properties and to enable their application in preventive medicine, particularly diagnostics based on multimodal imaging. All powders were synthesized through hydrothermal processing at T ≤ 200 °C. An X-ray powder diffraction analysis showed that all powders crystallized in P63/m space group of the hexagonal crystal structure. The refined unit-cell parameters reflected a decrease in the unit cell volume as a result of the partial substitution of Ca2+ with smaller RE3+ ions at both cation positions. The FTIR analysis additionally suggested that a synergy may exist solely in the triply doped system, where the lattice symmetry and vibration modes become more coherent than in the singly or doubly doped systems. HAp:RE3+ optical characterization revealed a change in the energy band gap and the appearance of a weak blue luminescence (λex = 370 nm) due to an increased concentration of defects. The "up"- and the "down"-conversion spectra of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders showed characteristic transitions of Tm3+ and Eu3+, respectively. Furthermore, in contrast to diamagnetic HAp, all HAp:RE3+ powders exhibited paramagnetic behavior. Cell viability tests of HAp:Gd/Yb/Tm and HAp:Gd/Eu powders in human dental pulp stem cell cultures indicated their good biocompatibility

Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion

Tanja Veselinović,1,2 Ingo Vernaleken,1,2 Paul Cumming,3,4 Uwe Henning,5 Lina Winkler,1,2 Peter Kaleta,1,2 Michael Paulzen,1,2 Christian Luckhaus,6 Gerhard Gründer1,2,7 1Department of Psychiatry, Psychotherapy, and Psychosomatics, Faculty of Medicine, RWTH Aachen University, Aachen, 2Translational Brain Medicine, Jülich Aachen Research Alliance (JARA), Jülich, Germany; 3IHBI, School of Psychology and Counselling, Queensland University of Technology, 4QIMR Berghofer Institute, Brisbane, Australia; 5Neurobiochemical Research Unit, Department of Psychiatry, Heinrich Heine University, Düsseldorf, 6LWL University Hospital Bochum, Department of Psychiatry, Division of Cognitive Neuropsychiatry and Psychiatric Preventive Medicine, Ruhr University Bochum, Bochum, 7Department of Molecular Neuroimaging, Central Institute of Mental Health, Mannheim, Germany Objectives: Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals.Methods: In this randomized, single-blinded study, groups of healthy volunteers (n=18) received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine) and each subject’s mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II) were assessed at the start and end of the trial.Results: Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective and subjective changes in general psychopathology scores, which correlated with individual increases in plasma homovanillic acid concentrations. Both objective and subjective impairments were significantly more pronounced in the subgroup with greatest increase of plasma prolactin. Subjects experiencing the most pronounced side effects under haloperidol, which compelled them to drop out, showed significantly higher prolactin concentration increases than those who tolerated haloperidol well.Conclusion: We found consistent associations between altered markers of dopamine transmission and several objective and subjective mental impairments in healthy volunteers after 1 week’s treatment with antidopaminergic medications. These findings should draw attention to a more intensive risk–benefit evaluation in cases of off-label prescription of antipsychotic medications. Keywords: catecholamine metabolites, HVA, prolactin, dopamine, reserpine, aripiprazole, haloperidol, off-label prescriptio

The missing link between wages and labour productivity in tourism

The present article aims to analyse wage-labour productivity cau-salities in Croatia and Slovenia using cointegration methods basedon monthly time series data of variables for labour productivityand real gross wages in tourism industry during the periodDecember 1999%January 2020. The data vector is integrated bychain indices with the constant base January 2000%100. A sto-chastic trend and shocks are covered in the analysis. Shocks arelinked to the European Union accession, and economic crisis fol-lowing with overwhelmed tourist arrivals. The contribution of theresearch is two-fold. First, the equations for at most normal dis-tributed variables of labour productivity and real wages in tourismare exposed. Three spatial cointegration relations confirm labourproductivity integrity of the regional tourism market. Second,pair-wise causalities indicate one cointegrated vector for labourproductivity, which drives real gross wages in tourism sub-indus-tries. These results suggest that for a higher non-seasonal assess-ment of real gross wage, the labour productivity should rise, i.e.less workers, more robotization or more tourist arrivals with betterquality solutions. These findings are at most important to beimplemented after the COVID-19 infection crisis with expectedrestructurings and digital transformation in the tourism industry

Soil gas mapping in the vicinity of Nikola Tesla thermo power plant disposal field

This paper presents the results of identification of natural ionizing irradiation in the vicinity of Nikola Tesla B power plant ash disposal field. The investigations have comprised the determination of natural gas (radon and thoron) activities with a passive discriminative nuclear track detector (CR 39) in the air column of the depth of 80 cm in the soil. The determination of gamma dose rate has been given as well, including the corresponding GPS coordinates of 28 measuring points

Microsatellite variability of Drosophila subobscura populations from the central Balkans

Background: Some populations of Drosophila subobscara (Collin) inhabit geographically separate and ecologically distinct habitats of the central Balkans. Hypothesis: Some of the separate populations were genetically isolated in glacial refugia and have subsequently diverged, leading to high genetic diversity. Methods: We sampled five different D. subobscum populations. Using fragment analysis for 11 microsatellite loci, we used standard diversity parameters (expected heterozygosity, allelic richness, allele size range) to estimate population genetic structure and genetic diversity. Results: We found significant differences in the number of alleles, range of allele sizes, and expected heterozygosity between populations from ecologically distinct microhabitats. However, their geographical distance from each other did not contribute to their genetic differences. Analysis of molecular variance showed slight inter-population differentiation (F-ST = 0.00996, P = 0.0215). Conclusions: Microsatellite variability parameters generally match those of other European populations. Drosophila subobscura populations of the Balkan Peninsula likely did not remain isolated in glacial refugia. Instead, our results indicate high levels of gene flow and local divergence at the molecular level.Ministry of Science and Technological Development, Republic of Serbia [173012

Microsatellite variability of Drosophila subobscura populations from the central Balkans

Background: Some populations of Drosophila subobscara (Collin) inhabit geographically separate and ecologically distinct habitats of the central Balkans. Hypothesis: Some of the separate populations were genetically isolated in glacial refugia and have subsequently diverged, leading to high genetic diversity. Methods: We sampled five different D. subobscum populations. Using fragment analysis for 11 microsatellite loci, we used standard diversity parameters (expected heterozygosity, allelic richness, allele size range) to estimate population genetic structure and genetic diversity. Results: We found significant differences in the number of alleles, range of allele sizes, and expected heterozygosity between populations from ecologically distinct microhabitats. However, their geographical distance from each other did not contribute to their genetic differences. Analysis of molecular variance showed slight inter-population differentiation (F-ST = 0.00996, P = 0.0215). Conclusions: Microsatellite variability parameters generally match those of other European populations. Drosophila subobscura populations of the Balkan Peninsula likely did not remain isolated in glacial refugia. Instead, our results indicate high levels of gene flow and local divergence at the molecular level.Ministry of Science and Technological Development, Republic of Serbia [173012

Multiyear indoor radon variability in a family house - a case study in serbia

The indoor radon behavior has complex dynamics due to the influence of the large number of different parameters: the state of indoor atmosphere (temperature, pressure, and relative humidity), aerosol concentration, the exchange rate between indoor and outdoor air, construction materials, and living habits. As a result, indoor radon concentration shows variation, with the usual periodicity of one day and one year. It is well-known that seasonal variation of the radon concentration exists. It is particularly interesting to investigate indoor radon variation at the same measuring location and time period, each year, due to estimation of individual annual dose from radon exposure. The long-term indoor radon measurements, in a typical family house in Serbia, were performed. Measurements were taken during 2014, 2015, and 2016, in February and July, each year. The following measuring techniques were used: active and charcoal canisters methods. Analysis of the obtained results, using multivariate analysis methods, is presented. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 171002: Nuclear Methods Investigations of Rare Processes and Cosmic Rays and Grant no. 43002: Biosensing Technologies and Global System for Continuous Research and Integrated Management

Effective population size in Drosophila subobscura: ecological and molecular approaches

The effective population size (Ne) represents the number of individuals that can contribute genes equally to the next generation and is usually smaller then the actual size of a population. The aims of this study were: (i) to assess the Ne for two Drosophila subobscura populations sampled from geographically close, but ecologically and topologically distinct habitats, (ii) to compare the results obtained from two independent approaches for estimating Ne [an ecological (capture-mark-release-recapture) and a molecular (microsatellite data, linkage disequilibrium and heterozygote excess)], and (iii) to obtain a long-term Ne estimation using a variety of mutational models for D. subobscura populations. The ecological method showed that the beech wood population (B) had a significantly larger Ne compared to the oak wood population (O). Observed sex ratio was in favor of females in both populations studied. The microsatellite analysis of populations showed that short-term effective population size in beech wood was larger when compared to population from oak wood, which is in concordance with results obtained by the ecological method. Long term Ne of both natural populations is infinite according to a variety of mutational models. Our results confirmed concordance between ecological and molecular methods in Ne estimation, but also suggested that ecological approach showed less robustness. Molecular approach provides a promising opportunity for more effective monitoring of Ne in Drosophila subobscura. However, the biology, demography and history of the populations may affect different estimators differently so we suggest that ecological and molecular approach should be combined in Ne estimation.Ministry of Education and Science and Technological Development, Republic of Serbia [173012