Abstract The amperometric biosensor was created using a flat sheet of the Cu-Zn-Al shape memory alloy, with a shiny surface and uniform thickness below 1 mm. The high biocompatibility and a large specific surface area for enzyme loading are evaluated. In vitro biomedical corrosion testing of samples revealed successful immobilization of catalase, which has undergone quasi-reversible electron transfer from the surface and saline solution. A catalase that had been immobilized retained its basic structure and bioactivity and demonstrated a remarkable electrocatalytic response to hydrogen peroxide reduction. The reduction of hydrogen peroxide on the catalase-modified Cu-25.38Zn-3.3Al alloy was investigated using hydrodynamic amperometry in both the absence and presence of l-cysteine and K2[B3O3F4OH] inhibitors. Catalytic reduction currents have increased as a result of the gradual increase in hydrogen peroxide concentration. The study on enzyme activity inhibition has shown a lower corrosion rate of catalase-modified bioalloy than the initial sample because inhibitor ions occupy all sites of the immobilized enzyme.

Glucocorticoids prevent or suppress the full inflammatory response to the infectious, immunological or physical agents by inhibiting early inflammatory events such as edema or cell exudation. The main effect of glucocorticoids on the inflammatory process is the inhibition or recruitment of neutrophils and monocytes. In this study, the effect of the glucocorticoid betamethasone on the hematological parameters of rats of the species Rattus norvegicus Berkenhout 1769 was examined in vivo. Betamethasone has been shown to affect the values of hematological parameters four hours after application and leads to a significant decrease in the prevalence of lymphocytes and monocytes, but also leads to a statistically significant increase in erythrocyte count, hemoglobin concentration and hematocrit values.

Aim: The chief aim of this study was monitoring of laboratory parameters of chronic kidney failure in elderly patients. Methods: All samples were taken and processed by standard methods and according to the principles of good laboratory practice. Data were collected in an organized and systematic manner in the form of a questionnaire with respect to ethical principles and as such were analyzed by statistical tests and analyses (Student's t-test, Analysis of variance-ANOVA, Pearson's and Spearman's correlation coefficients). The limit of statistical significance was set at p < 0.05. Results: Mean values of creatinine clearance and proteinuria for the total study population were: 41.30 ± 21.43 mL/min, 1.5 ± 2.3 g/L/24 h, respectively. Hematological parameters did not significantly differ from normal values. The highest frequency of comorbidities was observed in subjects aged ≥ 80 years with an average of 2.03 comorbidities per subject. Serum creatinine and urea values as well as creatinine clearance are good indicators of disease progression. Conclusion: The results of the presented research suggest that old age is a predisposing risk factor for the development of chronic kidney disease, and that in combination with comorbidities (hypertension and/or diabetes), it contributes to poor prognosis or disease progression.

Aluminium and its alloys have excellent corrosion resistance. When aluminium is exposed to the atmosphere, a thin invisible oxide Al2O3 is formed, protecting the metal from further oxidation. Compared to pure metals, alloys can have higher corrosion resistance depending on the content of certain alloying elements. Various substances such as organic or inorganic inhibitors can affect the corrosion of aluminium alloys and thus slow down the degradation of the material. In this paper, we studied the inhibitory effect of potassium dichromate on the corrosion processes of aluminium alloy. All measurements were performed in 0.5 M sodium chloride solution with the addition of different concentrations of inhibitors. The methods used were potentiodynamic polarization, cyclic voltammetry, and chronoamperometry.

Most pharmaceutical and nutritional compounds are marketed as enzyme inhibitors, and such inhibitors show their specific action in inhibiting enzymes within cells. Since their discovery, corticosteroid treatment has been one of the most used and effective treatments for various inflammatory and autoimmune disorders. Corticosteroids have anti-inflammatory and immunosuppressive effects, so it is hypothesized that these corticosteroids will have an inhibitory effect on the enzyme catalase. This study aimed to examine the effect of the corticosteroid’s betamethasone dipropionate and prednisone on catalase activity in vitro. A spectrophotometric method was used based on the reaction between hydrogen peroxide, enzymes, and corticosteroids. After incubation at 37°C with the addition of ammonium heptamolybdate, a stable complex was formed, and the absorbances were analysed. The obtained results indicate an uncompetitive type of inhibition in betamethasone dipropionate, while prednisone acts as a partial competitive agent.

Department of Chemistry, Faculty of Science, University of Sarajevo, Zmaja od Bosne 33–35, 71000 Sarajevo, Bosnia and Herzegovina Department of Biology, Faculty of Science, University of Sarajevo, Zmaja od Bosne 33–35, 71000 Sarajevo, Bosnia and Herzegovina Faculty of Metallurgy and Technology, University of Montenegro, Džordža Vašingtona bb, Podgorica, Montenegro University "Vitez", Vitez, Bosnia and Herzegovina

The Spectrophotometric method is one of the most suitable analytical techniques for testing the activity of enzymes under the influence of various factors. The effect of H1-antihistamines of loratadine and calcium ions on enzyme catalase under in vitro conditions was investigated in this paper. It has been shown that loratadine is a partial inhibitor of catalase, but this effect is diminished in the presence of calcium ions. Calcium as well as other cations are important for many biological and cellular functions. The kidneys play a central role in the homeostasis of these ions. The activity of the catalase enzyme under the given conditions, the type of inhibition, and the kinetic parameters of the enzyme reaction were determined. We concluded that loratadine is a partially competitive inhibitor.

Galvanic coatings are applied so that the surface of the base material obtains appropriate properties, corrosion resistance, durability, aesthetic appearance, and long-term application in the appropriate industry. In this paper, the aim was to protect steel fuel filters with alkaline and acid zinc coatings of different thicknesses. The coating of zinc, which is applied from the alkaline electrolyte, provides good corrosion protection with excellent coating flexibility. The thickness of the coating by the X-ray fluorescence method was tested, followed by coating tests, corrosion resistance, and electrochemical tests. The results of adhesion showed a high quality coating, as no corrosion occurred during the test. The corrosion resistance tested by the salt chamber method speaks of the appearance of white and red corrosion. On alkaline electrolyte coatings, white corrosion occurred after 168 hours of exposure to the salt test, while on white zinc samples there was a white corrosion after 240 hours of exposure. Tafel polarization diagrams have been determined: corrosion potentials, current intensities, anode and cathode Tafel coefficients and calculated corrosion rates. The active and passive corrosion zone is determined by the cyclic voltammetry.

1 Department of Chemistry, Faculty of Science, University of Sarajevo, Zmaja od Bosne 33-35, 71 000 Sarajevo, Bosnia and Herzegovina; 2 Faculty of Chemistry and Technology, University of Split, Teslina 10, 21 000 Split, Croatia; 3 Department of Biology, Faculty of Science, University of Sarajevo, Zmaja od Bosne 33-35, 71 000 Sarajevo, Bosnia and Herzegovina; 4 Clinical Center of the University of Sarajevo, Organizational unit Clinical chemistry and biochemistry, Bolnička 25, 71 000 Sarajevo, Bosnia and Herzegovina; 5 Faculty of Pharmacy, University of Sarajevo, Zmaja od Bosne 8, 71 000 Sarajevo, Bosnia and Herzegovina; E-mail: islamovic.safija@gmail.com