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Heavy metals belong to a group of substances, which, after reaching a natural habitat, can manifest various negative effects. This paper analyses heavy metals (Cu, Cd, and Pb) in the Una river and fish samples, whereby individuals of grayling (Thymallus thymallus) were used for analysis. The samples were taken at three locations at the Una river: Ripac, Hatinac, and Grmusa. Alongside with the examination of the content of heavy metals, quality of water was tracked, including the following parameters: temperature, pH, electrical conductivity, dissolved oxygen, suspended matter, BPK5, KPK – Cr, total nitrogen – N, total phosphorus P, sulphates, chlorides, nitrites – NO2, nitrates – NO3, fluoride, and heavy metals (Cu, Cd, and Pb). Besides the content of heavy metals, proteins, fats, water, carbohydrates, and mineral matter were found in the grayling fillets. Amount of heavy metals (Pb, Cu, and Cd) were under maximum allowed concentration (MAC).             Key words: heavy metals, water, fish.

Coefficients of organs, along with haematological characteristics, represent an important means of monitoring the health and condition of fish. Organosomatic indices show the state of organ systems and individual organs. They manifest as changes in size, which are reflected through a decrease or increase, under the influence of environmental factors. Chub individuals from the Suturlija River were used for analysis. The paper analyses the Fulton's condition factor, heart, liver, and spleen coefficients as a condition factor. Furthermore, the values of total length, standard length, and body weight were determined for all individuals. Also, certain haematological parameters were analysed in the paper: total leukocyte count and differential blood count. A total of 19 chubs caught from the Suturlija River were analysed. The obtained result of Fulton's condition factor (1.53) indicates favourable habitats for chub individuals in the Suturlija River. The results of organosomatic indices are without major variations between individuals (CSI = 0.184, SSI = 0.992, HSI = 0.133). The mean leukocyte count was 45.857x109/l, with the highest proportion of lymphocytes in the differential

Objectives: The global burden of the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing the corona virus disease-19 (COVID-19) is enormous No definitive treatment and prophylactic guidelines for COVID-19 currently exist except for physical distancing and aerial barriers between individuals This work explored the natural compound-binding efficiency of SARS-CoV-2 proteins essential for host cell interaction and infection Methods: The binding activity of artemisinin to SARS-CoV-2 spike glycoprotein (Protein Data Bank (PDB) ID: 6VYB), SARS-CoV-2 main protease (3C-like main protease (3CLpro);PDB ID: 6Y84) and SARS-CoV-2 papain-like protease (PLpro;PDB ID: 6W9C), were tested using in silico methods Moreover, chloroquine and hesperidin were used as the positive control of binding affinity and proven therapeutic effect, respectively Results: The highest affinities for binding to all tested SARS-CoV-2 proteins are observed for hesperidin (-5 8,-10 0, and -8 1 kcal/mol), then for artemisinin (-4 8,-8 3, and -6 0 kcal/mol), and the lowest for chloroquine (-4 1,-8 2, and -4 8 kcal/mol) Artemisinin, hesperidin, and chloroquine had similar positioning toward targeted proteins at specific sites when these interactions were visualized Conclusion: This study shows that artemisinin has the potential to bind and inhibit the SARS-CoV-2 spike protein, the 3CLpro main protease, and PLpro proteinase similar to hesperidin and chloroquine that have been proven as antivirals in previous preclinical and clinical studies

Cationic NLCs represent lipid vesicles bearing cationic lipids on its surface, which leads to electrostatic interactions with negative charges of the nucleic acids such as miRNA and formation of a complex which protect the nucleic acids from the inevitable physicochemical biological impacts within the blood circulation [1]. This study aimed to develop cNLCs in order to obtain the most suitable formulation for further delivery of miRNAs.

Oil-in-water cationic nanoemulsions (CNE) are fine dispersions consisting of an oil core (from natural or synthetic origin) stabilized by a single cationic lipid or a mixture with phospholipids, non-ionic surfactants, and/or PEG-lipids. CNEs are considered to be suitable and potential delivery system for nucleic acids in gene therapy field due to their positively charged surface which complex with negatively charged gene material through electrostatic interactions [1]. The aim of the present study was to evaluate the effect of cationic lipid-sterylamine (SA) on mean droplet size, zeta potential and pH of the CNEs. Formulations containing various concentrations of SA were prepared on high-pressure homogenizer. The mean droplet size and zeta potential of the emulsions were determined by photon correlation spectroscopy and electrophoretic light scattering, respectively (Malvern NanoZs Zetasizer). The mean droplet size of emulsions varied from 126 to 129 nm while the polydispersity index varied from 0,068 to 0,137. As expected, zeta-potential increased from +43,7 mV to +53,7 mV with the SA concentration increase from 0,25 to 0,75 % (w/w). During the 60-day storage period at 25 °C, the droplets stayed in the nanometer range with only a minor size increase (~10 nm), no significant changes in droplet size distribution nor zeta potential or any difference in their visual appearance (no creaming or phase separation) proving therefore a satisfactory formulation stability.

The total excellence of university teaching largely depends on pedagogical and didactical­methodical competencies of university professors. The development and promotion of academic teaching is enabled by the modernization of the teaching process which does not encompass only modernization of curriculum but the entire didactical­methodical organization of teaching. Pleasure and requirements of students are to be accentuated accordingly, as well as competencies of teachers and expectations of labor market. The purpose of this paper is to establish which element of didactical­methodical organization of university teaching is the most important dimension of excellence of teaching as well as in what way university professors perform self­evaluation of the excellence of didactical­methodical organization of teaching at the University of Tuzla. The analytical­descriptive survey method was used as a variant of analytical­descriptive method as well as procedures of analysis of contents and polling. It is supposed that there is statistically significant difference in self­evaluation of the importance of elements of excellence in didactical­methodical organization of teaching at the University of Tuzla and that self­evaluations of the importance of individual elements of excellence of university teaching differ with regard to age, sex, teaching/academic title, years of experience in academic institutions and scientific field the faculty belongs to. The results of this research show that the excellence of planning and preparation and excellence in choice of teaching methods are the most important elements of excellence in the organization of university teaching, and that 90% of teaching personnel evaluates that the classes they organize are at very high level of excellence.