Modelling the hypothalamic-pituitaryadrenal (hpa) axis response to external perturbations with cortisol

Glucocorticoids, the end products of the Hypothalamic-Pituitary-Adrenal (HPA) axis, are widely used as anti-inflammatory and immunosuppressive drugs. However, the feed-back effects of externally induced glucocorticoids on the HPA axis activity remain widely unknown. In this study, we use numerical simulations to investigate changes in the HPA axis activity caused by externally introduced cortisol. We emulate the basal HPA activity using a stoichiometric model of the HPA axis, and perturb its dynamics by abruptly changing cortisol levels during the course of numerical integration, thereby mimicking cortisol increase under treatment. Our study shows that the HPA axis activity is susceptible to perturbations by cortisol and that external cortisol pulses elicit different responses, depending on the dose and the time of cortisol introduction

COMPARATIVE ANALYSIS OF SELECTED TISSUES OF BROWN TROUT FROM THE FISH POND AND RIVER PLIVA, BOSNIA AND HERZEGOVINA

Potočna pastrva česta je vrsta ribe koja se uzgaja u otvorenim, protočnim ribogojilištima u konzumne svrhe na rijekama Bosne i Hercegovine. Lokalitet Pljeva na rijeci Plivi u srednjoj Bosni idealan je za uzgoj pastrve te uzgajivači ovih područja imaju dugu tradiciju uzgoja u otvorenim - protočnim ribogojilištima. U cilju sagledavanja morfoloških i histoloških obilježja pastrva iz ovih ribnjaka u usporedbi s onima izvan ribnjačkog uzgoja provedena je ova studija kroz tri sezone: proljeće, ljeto i jesen, kako bi se vidjela potpuna slika stanja odabranih tkiva i kondicije potočnih pastrva. Analizirana su fizičko-kemijska obilježja vode iz rijeke Plive kod Pljeve i iz ribogojilišta koji se bavi intenzivnim uzgojem potočnih pastrva. Ove analize su pokazale da ne postoje velika odstupanja u kvaliteti vode i da je voda u ribogojilištu dobre kvalitete. Izlovljeno je ukupno 90 jedinki kroz sve tri sezone i analizirane su morfometrijske karakteristike na deset parametara. Nakon disekcije provedena je histološka i stereološka analiza s ciljem komparacije tkiva jetre, želuca, škrga i mišića. Ove analize su pokazale značajne razlike u histoarhitekturi odabranih tkiva pastrva iz ribnjaka u odnosu na rijeku. Tkivo jetre bilo je s izmijenjenim oblikom hepatocita i prisustvom adipocita; tkivo želuca bilo je s jačom mukozom i slabijim mišićnim slojem; tkivo škrga imalo je niže respiratorne lamele, dok je mišićno tkivo imalo znatno prisustvo masnog tkiva kod pastrva iz ribogojilišta u odnosu na one iz rijeke. Sve promjene su posljedica kvalitete komercijalne hrane kao i nemogućnosti slobodnog kretanja.Brown trout is a common type of fish grown for consumption in open and flowing fish ponds on the rivers of Bosnia and Herzegovina. We conducted this study during three seasons (spring, summer and autumn) to obtain a complete picture of the morphological and histological characteristics of selected trout tissues. The physicochemical characteristics of the water from the Pliva River near Pljeva and the fish pond where intensive breeding of trout is carried out were analyzed. These analyses have shown that there are no major deviations in water quality and that the water in the pond is of excellent quality. A total of 90 trout were harvested during all three seasons and their morphometric characteristics were determined by analyzing ten parameters. After the dissection of all individuals, histological and stereological analysis was performed to compare the tissues of the liver, stomach, gills and muscles. These analyses showed significant differences in the histoarchitecture of selected trout tissues from the pond compared to the river. Liver tissue had altered hepatocyte shape and presence of adipocytes; stomach tissue had stronger mucosa and weaker muscle layer; gill tissue had lower respiratory lamellae; while muscle tissue had a significant presence of adipose tissue in brown trout living in the fish pond compared to those in the river. All these changes are due to the quality of commercial feed and the inability to move freely

Dynamic adsorption characteristics of thin layered activated charcoal materials used in chemical protective overgarments

The efficiency of a thin layered activated charcoal material used in chemical protective overgarments has been evaluated. The study has been conducted with the aim to obtain protective materials with best characteristics considering resistance to benzene effect under dynamic conditions and to create a new filtration protection device. In order to evaluate dynamic adsorption characteristics of thin layered sorption materials, sophisticated dynamic gas chromatography method is used. The curves of benzene penetration are determined for sandwich materials, and sorption layers used in filtrating protective clothing shows that thin layered carbon sorption materials (type MOO) have good protective properties as compared to other similar materials. The findings will help to create conditions for developing a functional model for producing a new protective overgarment in the near future

Dynamic adsorption characteristics of thin layered activated charcoal materials used in chemical protective overgarments

The efficiency of a thin layered activated charcoal material used in chemical protective overgarments has been evaluated. The study has been conducted with the aim to obtain protective materials with best characteristics considering resistance to benzene effect under dynamic conditions and to create a new filtration protection device. In order to evaluate dynamic adsorption characteristics of thin layered sorption materials, sophisticated dynamic gas chromatography method is used. The curves of benzene penetration are determined for sandwich materials, and sorption layers used in filtrating protective clothing shows that thin layered carbon sorption materials (type MOO) have good protective properties as compared to other similar materials. The findings will help to create conditions for developing a functional model for producing a new protective overgarment in the near future

Kinetics study of the disproportionation of the iodous acid in aqueous sulfuric acid solution

In this paper we reported the kinetics of the disproportionation reaction of iodous acid (HOIO) in aqueous sulfuric acid solutions (0.18 mol/dm3) studied by spectrophotometrical measurements of the absorbance at suitable wavelength. The changes of the absorbance were caused because the absorbing I2 molecule species were generated during the reaction. The disproportionation rate constants are calculated at the temperature range between 285 and 303 K with average values: k285 = (0.90 ± 0.08) dm3mol-1s-1, k291 = (1.10 ± 0.10) dm3mol-1s-1, k298 = (1.30 ± 0.07) dm3mol-1s-1 and k303 = (1.50 ± 0.10) dm3mol-1s-1, respectively. The corresponding activation energy was determined, for the chosen temperature interval, by a graphical method. In addition, obtained value of activation energy is Ea = 38 ± 5 kJ/mol. The negative value of Gibbs energy change and other thermodynamical parameters show that is the disproportionation reaction thermodynamically feasible

One-Pot Syntheses of PET-Based Plasticizer and Tetramethyl Thiuram Monosulfide (TMTS) as Vulcanization Accelerator for Rubber Production

Styrene-butadiene (SBR) and acrylonitrile-butadiene (NBR) rubber blends with tetramethyl thiuram disulfide (TMTD) and tetramethyl thiuram monosulfide (TMTS) accelerators and environmentally friendly plasticizers, obtained from PET recycling and biobased resources (LA/PG/PET/EG/LA), were prepared. The mechanical properties of the obtained rubber products were tested and compared with those of commercial dioctyl terephthalate (DOTP). TMTS was prepared by simple and efficient one-pot synthesis from dimethylamine, carbon disulfide, potassium cyanide, and ammonium chloride as catalysts in recycled isopropanol/water azeotrope as solvent. In a comparative study, methoxide, ethoxide, iodide, and amide ions were also used. The two-step reaction mechanism of TMTS synthesis involves the oxidation of the amine salt of dimethyldithiocarbamic acid to TMTD by hydrogen peroxide and sulfur elimination from the TMTD disulfide bond. Potassium cyanide appears to be the most efficient nucleophile. The simplicity of operation, mild reaction conditions, solvent recycling, high yields, and applicability to the industrial level are the advantages of this process. Shore hardness, tensile strength, and compression test results of vulcanized blends before and after aging showed similar properties for both accelerators, while somewhat better results were obtained with LA/PG/PET/EG/LA plasticizer