Investigation of potentially toxic elements in urban sediments in Belgrade, Serbia.

Concentrations of 10 potentially toxic trace elements were measured in soil samples collected from 18 sites in urban areas of Belgrade, the capital and the largest city in Serbia. Samples were analysed in order to assess the extent of soil contamination and to distinguish natural and anthropogenic input. The results demonstrated a general Zn, Pb, and Cd enrichment in surface samples, hence, after comparison with guidelines, it has been determined that there is a potential risk for human health. In the surface and buried samples, traces of cooper were detected. The highest concentrations of Cr (121 ± 12.3 mg/kg) and Ni (94.9 ± 12.6 mg/kg) were found at a sediment depth of 2 m and should be ascribed to geogenic sources. The results of HCA and PCA analysis supported a natural origin of Co, Cu, Mn, Cr, and Ni, while Cd, Zn, and Pb originated from anthropogenic inputs. Based on the pollution indices, Cd made the most dominant contribution, posing a high contamination risk in the studied area. Results of Nemerow pollution index (PIN) and potential ecological risk index (PER) demonstrated that pollution by heavy metals in sediments on several sites is moderately intense.

Natural attenuation of petroleum hydrocarbons-a study of biodegradation effects in groundwater (Vitanovac, Serbia).

The role of natural attenuation processes in groundwater contamination by petroleum hydrocarbons is of intense scientific and practical interest. This study provides insight into the biodegradation effects in groundwater at a site contaminated by kerosene (jet fuel) in 1993 (Vitanovac, Serbia). Total petroleum hydrocarbons (TPH), hydrochemical indicators (O2, NO3-, Mn, Fe, SO42-, HCO3-), δ13C of dissolved inorganic carbon (DIC), and other parameters were measured to demonstrate biodegradation effects in groundwater at the contaminated site. Due to different biodegradation mechanisms, the zone of the lowest concentrations of electron acceptors and the zone of the highest concentrations of metabolic products of biodegradation overlap. Based on the analysis of redox-sensitive compounds in groundwater samples, redox processes ranged from strictly anoxic (methanogenesis) to oxic (oxygen reduction) within a short distance. The dependence of groundwater redox conditions on the distance from the source of contamination was observed. δ13C values of DIC ranged from - 15.83 to - 2.75‰, and the most positive values correspond to the zone under anaerobic and methanogenic conditions. Overall, results obtained provide clear evidence on the effects of natural attenuation processes-the activity of biodegradation mechanisms in field conditions.

Half of expectant women in Montenegro show iodine deficiency, indicating that supplementation during pregnancy is necessary.

OBJECTIVE: In this study, iodine level in pregnant women of Montenegro and their needs for supplementation were investigated. METHODS: A urinary iodine concentration (UIC) study of 326 pregnant women between September and December 2017 in three regions of Montenegro was performed. UIC was related to creatinine (UI/Cr ratio). RESULTS: The median UIC (133 ± 5 µg/L) was indicative of iodine deficiency, as the WHO recommended UIC is 150-249 µg/L. The UI/Cr ratio (160 ± 6 µg/g creatinine) was just above the WHO/UNICEF/IGN recommendation. Approximately 50% of the surveyed women had a lower UIC than that recommended. CONCLUSION: Iodine deficiency is present in pregnant women in Montenegro. Monitoring the UIC during routine analyses in pregnant women in Montenegro is recommended, along with iodine supplementation for individuals that need it.

Study on the assessment of humification processes during biodegradation of heavy residual fuel oil.

The aim of this study was to investigate the creation of humic substances during biodegradation of heavy residual fuel oil, because there are indications that substances similar to humic substances are generated during biodegradation of polycyclic aromatic hydrocarbons. In the study, which lasted for 110 days, biodegradation of heavy residual fuel oil was carried out in a layer of artificial soil substrate. The initial concentration of the total petroleum hydrocarbon in the prepared artificial soil substrate (biopile) was 23.1 g kg-1 dry weight (d.w.). At the end of the process, the total petroleum hydrocarbons were reduced to 8.1 g kg-1 d.w. in the inoculated biopile, while the content of humic acids increased during bioremediation from 3.15 g kg-1 d.w. to 4.95 g kg-1 d.w. The humic acids extracted from biopile during the biodegradation process were characterized by various chemical techniques (elemental analysis, spectrofluorimetric analysis, electrochemical measurements, and size exclusion chromatography). The results showed that levels of C, H and the H/C ratio decreased as the biodegradation process progressed. This indicated that humic acids aromatization process took place and this was confirmed by the spectrofluorimetric analysis. The increase of oxygen percentage and the O/C ratio in the humic acids after the biodegradation treatment indicated an increase in functional oxygen groups. Additional analyses of humic acids from the inoculated biopile showed that they were transformed during the bioremediation process. They had greater redox and buffering capacities and a larger portion of the fractions had high molecular mass. Also, the humification parameters (the CHAs/CFAs ratio and CHAs/Corg ratio) increased during the biodegradation. This is one of the few studies that describes the generation of humic substances during the biodegradation of oil compounds.

Edaravone May Prevent Ferroptosis in ALS.

Radicava™ (Edaravone) was approved the Food and Drug Administration (FDA) as a new treatment for amyotrophic lateral sclerosis (ALS). Edaravone is a synthetic antioxidant that specifically targets oxidative damage interacting with lipid radicals in the cell. In ALS disease the multiple cell types are involved in devastating loss of motor neurons. Mutations and biochemical changes in various cell types jointly contribute to motor neuron death, disease onset, and disease progression. The overall mechanism of neurodegeneration in ALS is still not completely understood. Dying motor neurons have been reported to exhibit features of apoptosis. However, non-apoptotic features of dying motor neurons have also been reported such as ferroptosis. The role of Edaravone in the prevention of ferroptosis in parallel with other therapeutic approaches to ALS therapy is discussed.

Zinc concentrations in human milk and infant serum during the first six months of lactation.

Normal supply of zinc to the newborn via milk is essential for normal development. Using ICP-OES, we analyzed changes in the level of Zn in milk and infant serum in the neonatal period (Day 1 and Day 28 post partum) and at 6 months after delivery, in the cohort of 60 mothers and exclusively breastfed babies. Zn level in the serum showed increase (significant at 6 months) during this period (mg/mL): Day 1: 0.52±0.12; Day 28: 0.59±0.19; 6 months: 0.68±0.28. The concentration of Zn in the milk showed an opposite (decreasing) trend during the follow up: Day 1: 4.70±1.74mg/L; Day 28: 2.65±1.06; 6 months: 0.46±0.36. A significant negative correlation was established between serum and milk [Zn] at day 28 (R=-0.338; p=0.008), whereas a positive correlation was found at 6 months between these parameters (R=0.306; p=0.018). There was no significant correlation between [Zn] in the milk and serum and infants' body mass, mothers' age and mass at delivery. The level of Zn in the milk at 6 months of lactation is not sufficient to meet the recommended values. This implies that in Serbian population, Zn supplementation might be needed in the later phase of lactation.

Aqua regia extracted metals in sediments from the industrial area and surroundings of Pancevo, Serbia.

Surface and buried sediments were analyzed for Ba, Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn and V, as well as for total carbon and hydrogen to assess the distribution of sediment pollution due to the vicinity of the petrochemical complex. The samples, collected from 20 locations within the petrochemical complex and from 16 locations outside the complex, were aqua regia extracted and analyzed by ICP/OES. Metals were determined with an acceptable accuracy for certified metals of 82-113%. The precision for the aqua regia extraction was satisfactory, less than 20%, except for Cd where it was 28%. Comparison of the data from the petrochemical with those from the non-petrochemical areas showed different distributions of the metals. Metals that exceeded the baseline range; Ba, Cd, Cu, Zn and Pb, were detected in higher concentrations in sediments that were under the influence of the chlor-alkali plant within the petrochemical complex. Comparison with data from the petrochemical complex and its surroundings and their distribution demonstrated that the metal compositions of the sediments were modified by anthropogenic activities.

Relationships between structure, retention and biological activity of some Schiff base ligands and their complexes.

The lipophilicity of a series of Schiff base ligands and their complexes with nickel(II) and copper(II) has been determined by reversed-phase thin-layer chromatography using binary dioxane-water mobile phase. Chelate ligands were prepared by condensation of diamine and the corresponding beta-diketone. Copper(II) and nickel(II) complexes with chelate ligands containing ethane-1,2-diamine or propane-1,2-diamine as the amine part and pentane-2,4-dione and/or 1-phenylbutane-1,3-dione, pentane-2,4-dione and/or 1,1,1-trifluoropentane-2,4-dione, or 1,1,1-trifluoropentane-2,4-dione and/or 1-phenylbutane-1,3-dione as the beta-diketone part were synthesized. Some of investigated compounds were screened for their in vitro antifungal activity against Sacharomyces cerevisiae and antibacterial activity against Escherichia coli. Chromatographically obtained lipophilicity parameters were correlated both with calculated n-octanol-water partition coefficient C log P and antimicrobial activities. Satisfactory correlations were obtained. Chromatographic data proved to be reliable parameters for describing the lipophilic properties of the investigated compounds. Additionally, the principal components analysis was performed on the data chromatographically obtained. This statistical method was useful for distinguishing compounds and objective comparison of their lipophilicity parameters.