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Kao odgovor na veliku nesreću koja se dogodila u Meksičkom zaljevu 2010. godine, Europski parlament i Vijeće donijeli su Direktivu 2013/30/EU o sigurnosti odobalnih naftnih i plinskih djelatnosti. Direktiva 2013/30/EU je prenesena u pravni sustav Republike Hrvatske putem Zakona o sigurnosti pri odobalnom istraživanju i eksploataciji ugljikovodika NN 78/15, 50/20. Sukladno zakonskoj regulativi, svako odobalno postrojenje mora imati izrađeno Izvješće o velikim opasnostima, prihvaćeno od strane nadležnog tijela, kao dokaz da su utvrđene velike opasnosti, da je procijenjena njihova vjerojatnost i posljedice te da su mjere nadzora tih opasnosti prikladne kako bi se rizik od nesreća smanjio na prihvatljivu razinu. U ovom radu predstavljeni su svi važni dokumenti koje operator ili vlasnik odobalnog postrojenja izrađuje u svrhu usklađivanja sa zakonskom regulativom na području sprječavanja velikih nesreća, s posebnim naglaskom na najvažniji dokument, Izvješće o velikim opasnostima. Predstavljene su metode procjene rizika koje se mogu primijeniti kod izrade Izvješća o velikim opasnostima, kao i opis kontrolnih mjera za svođenje rizika od pojave velikih nesreća na odobalnim eksploatacijskim objektima na prihvatljivu razinu. Europska komisija objavljuje Godišnja izvješća o stanju sigurnosti u europskim vodama. Analizom podataka iz godišnjih Izvješća, procijenjen je doprinos nove zakonske regulative u postizanju veće sigurnosti pri odobalnom istraživanju i eksploataciji ugljikovodika., In response to the major accident that has occurred in the Gulf of Mexico in 2010, the European Parliament and the Council adopted the Directive 2013/30/EU on the safety of offshore oil and gas activities. The Directive 2013/30/EU was transposed into the legal system of the Republic of Croatia by the Act on Safety in Offshore Exploration and Production of Hydrocarbons OG 78/15, 50/20. According to the legislation, a Report on Major Hazard accepted by the competent authority must be prepared for each offshore installation, demonstrating that the main hazards have been identified, that their likelihood and consequences have been assessed, and that the control measures for these hazards are adequate to reduce the risk of accidents to an acceptable level. This thesis presents all the main documents prepared by the offshore operator or owner for the purpose of harmonization with the legislation in the field of major accident prevention, focusing on the most important document, the Report on Major Hazards. The thesis presents the risk assessment methods that can be used in the preparation of the hazard report, as well as the description of control measures used to reduce the risk of major accidents in offshore installations to an acceptable level. The European Commission publishes the Annual Reports on the Safety of Offshore Oil and Gas Operations in the EU. By analyzing the data from the annual reports, the contribution of the new legislation to increased safety in offshore hydrocarbon exploration and production was assessed.

Turizam je stekao status jedne od najmasovnijih, najdinamičnijih i najsloženijih društveno-ekonomskih pojava suvremenoga doba, zadire gotovo u sve sfere društvenog i gospodarskog razvoja općenito, a međusobno djeluje kompleksno i komplementarno te je duboko inkorporiran u tijekove svakidašnjeg života sveobuhvatnog društva. Uz ekonomsko značenje, turizam je postala i popularna aktivnost većine ljudi u razvijenom svijetu, a uz to je i najbrže rastućih grana svjetske ekonomije. Turizam je također od velike važnosti za nacionalno gospodarstvo, ukratko turizam pozitivno utječe na zaposlenost u zemlji, BDP, investicije, pozitivan imidž zemlje u prezentiranom svijetu, utječe na kulturni razvoj itd. Veliku ulogu u samom razvoju turizma ima i suradnja javnog i privatnog sektora, čija je suradnja na ovom području neizbježna. Javno–privatno partnerstvo generalno označava suradnju tijela javne vlasti i privatnog sektora, a sve kako bi se zadovoljile određene potrebe javnosti. Svaki od partnera ima određene odgovornosti, preuzima razne vrste rizika, ali i ostvaruje različite koristi. Javni sektor ne može sam zadovoljiti rastuće potrebe za uslugama pa s obzirom na to treba potporu raznih sektora iz društva. Ekonomska efikasnost javno-privatnog partnerstva u turizmu ovisi o tome jesu li javno-privatna partnerstva uistinu prava, što podrazumijeva povećanje opće društvenog blagostanja te ovisi o tome da li se može društveno opravdati primjenom istog metodološkog postupka kao i u slučaju javno-privatnih partnerstva u sferi opskrbe tržišta javnim dobrima. Tourism has acquired the status of one of the most massive, dynamic and complex socioeconomic phenomena of the modern era, it penetrates into almost all spheres of social and economic development in general, and permeates each other in a complex and complementary manner and is deeply integrated into the everyday life of a comprehensive society. In addition to its economic importance, tourism has become a popular activity for most people in the developed world, and it is also one of the fastest growing branches of the world economy. Tourism is also of great importance for the national economy, in short tourism has a positive effect on employment in the country, GDP, investments, a positive image of the country in the presented world, influences cultural development, etc. Cooperation between the public and private sectors also plays a major role in the development of tourism itself, and their cooperation in this area is inevitable. Public-private partnership generally means cooperation between public authorities and the private sector, all in order to meet certain needs of the public. Each of the partners has certain responsibilities, assumes various types of risks, but also realizes different benefits. The public sector cannot meet the growing needs for services alone, so it needs the support of various sectors of society. The economic efficiency of public-private partnerships in tourism depends on whether public-private partnerships are truly right, which implies an increase in general social well-being, and depends on whether it can be socially justified by applying the same methodological procedure as in the case of public-private partnerships in the sphere of supply public goods markets.

Microalgae and their potential for food supplementation are a growing trend in modern society. Whole microalgal biomass and their extracts are rich in nutrients which give various health benefits. To further improve their characteristics as food supplements a co-cultivation with probiotic strains emerged as a new innovative way to increase nutrititional value. In order to increase probiotic strain acitivites, algae are usually added in powder form to cultivating broth. In this study, we performed co-cultivation of probiotic bacteria and viable microalga Chlorella vulgaris. Our main goal was to investigate if this approach can benefit to both organisms. We focused on optimization of growth conditions, examing inoculation ratio, temperatures, culturing volumes and media in correlation with biomass accumulation. Determination of C. vulgaris biomass composition has been performed using Nile Red (NR) method with flourescence microscopy for lipid accumulation ; spectrophotometry for pigments and Lowry method for protein yield. Metabolite products synthesized and released in culture medium, as well as metabolites embedded in biomass composition, were analysed using quadrupole time-of-flight (q-TOF) mass spectrometry revealing production of new compounds. Results of these comprehensive analysis will be presented.

Brown macroalgae or seaweeds have recently been in the focus of many researchers due to their composition and the accumulation of specific metabolites with great antioxidant potential. They represent a valuable source of bioactive compounds: polyphenols, pigments, peptides and polysaccharides that are associated with several health benefits and biological activities. Food, cosmetics and pharmaceutical industries are constantly working to find natural, non-toxic compounds that can be used in their products. In this study, we evaluated the antioxidant activity of two (methanolic F3 and dichlormethane F4) different fractions from macroalga Halopteris scoparia in order to determine differences between harvesting season. Total protein content, chlorophyll and carotenoid content were determined. Also, several methods were used for evaluation of antioxidant activity. The semipurified fractions were also tested for antimicrobial activity using broth microdilution method for quantitative assessment and the toxicity of samples was determined using the zebrafish embryotoxicity test up to 96 h of embryonal development in order to reveal the safety of their usage and further implementation. Pearson’s correlation coefficient was used to correlate obtained results for antioxidant activity. All methanolic fractions showed higher antioxidant activity than the dichloromethane fractions of the same season by implementing 3 different antioxidants assays, namely reduction of the radical cation (ABTS), the 2, 2-diphenyl-1 picrylhydrazyl (DPPH) and the oxygen radical absorbance capacity (ORAC) assays. April sample of H. scoparia (HASC) methanolic fraction (F3) showed the highest activity (268.6±20.6 mg AAE/g fraction) followed by HASC F4 April and HASC F3 February samples by DPPH method (Fig.1a). By using ABTS assay, the highest activity was observed for HASC F3 February followed by F3 April and F3 July fractions. The highest protein value was observed for Halopteris scoparia April sample (20.5%) followed by HASC July (19.7%) and February (14.3%) samples. Chloropyll a and its derivate pheophytin a are dominant pigments in all three samples and the highest pigment content (chloropyll a and b, pheophytine a and b and carotenoids) was observed for HASC February sample. Obtained results indicate that harvesting season has a crutial role in obtaining samples with the best properties that have a potential to be used as a source of natural antioxidants in the food, pharmaceutical and cosmetic industry.

Spirulina sp. is a widely cultivated cyanobacteria which contains a high amount of bioactive compounds with health-promoting effects and remarkable antioxidant activity due to the abundant presence of polyphenols and carotenoids. The effect of different drying temperatures (room temperature, 40, 50, 60, 80, and 100°C) on the phenolic profile and biological activity of Spirulina sp. was investigated. Samples were dried at various temperatures, extracted and then fractioned. Antioxidant activity of methanolic (F3) and dichloromethane (F4) fractions was evaluated using ABTS, FRAP, ORAC and DPPH assays. To determine the toxicity potential of prepared fractions, zebrafish embryotoxicity test was performed [2]. Phenolic compounds in Spirulina sp. samples were identified using HPLC, while LC/ MS- Q-TOF screening was used to predict the most probable bioactivities, chemical classes and drug- likeness properties of examined compounds. According to antioxidative assays, F3 fraction had higher ABTS and FRAP activity, while F4 fraction had higher DPPH and ORAC activity. The F4 fraction dried at 50°C showed the highest antioxidant activity using DPPH (687.06 +/- 11.41 mg AAE/g fraction), while ABTS and FRAP assays showed high activity for F3 fractions dried at 25, 30 and 100°C. There was no negative impact on the survival of zebrafish embryos and larvae observed at concentrations lower than 0.02 mg/mL. The most abundant polyphenols were epicatechin, vanillic acid, caffeic acid, diosmin, thymol, apigenin, while the presence of 3 alkanolamines and 25 lipid-like molecules was revealed by QTOF analysis. High antioxidant activity was observed at lower temperatures can be related to the presence of carotenoids and chlorophyll. Antioxidant potential of sample dried at 100°C can be attributed to pigment derivatives. The optimal temperature for preservation of polyphenols was 50 °C. A strong correlation between structural class of detected compounds and highly predicted activities (cardiovascular, antiinflammatory, anticancer) has been observed. The results indicate that drying at a lower temperature retains phenols and other components and maintains high antioxidant activity. From the obtained results, it can be concluded that lower drying temperatures better influence the content of phenolic compounds and biological activity of Spirulina sp., when compared to higher temperatures.

Marine macroalgae or seaweeds are in a continuous focus of the scientific community, but even in the focus of a wider public as they are acknowledged as a valuable source of different bioactive compounds such as polyphenols, peptides, pigments, and polysaccharides that are associated with several health benefits and biological activities. Brown algae are known for their accumulation of specific metabolites with great antioxidant potential. In this study, we evaluated the antioxidant activity of different fractions from two brown macroalgae, Dichtyota dichotoma, and Dichtyota fasciola. The primarily used method was square-wave voltammetry (SWV), followed by the reduction of the radical cation (ABTS), the 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) assay, the Folin–Ciocalteu, and the oxygen radical absorbance capacity (ORAC) assays. To correlate obtained results for antioxidant activity, Pearson’s correlation coefficient was used. Toxicity evaluation of obtained fractions revealed the safety of their usage and further implementation. In this research, the dry residues of extracts from brown macroalgae samples were immobilized on the surface of GCE and immersed into a 0.1 mol/L phosphate buffer solution. To evaluate their activity and optimal electrochemical response, a change in the pH values, ranging from 3 to 11, for all obtained extracts was tested. To assess antioxidant activity using voltammetric analysis, the area under the curve (AUC) was integrated, the value of which represents an estimate of the total antioxidant activity of the extracts. The highest antioxidant activity based on the AUC value was obtained for D. fasciola F2 (0.099±0.001 mg/g GAE) followed by D. fasciola F3 (0.068±0.006 mg/g GAE) > D. dichotoma F3 (0.050±0.002 mg/g GAE) > D. dichotoma F2 (0.028±0.002mg/g GAE). No significant difference in antioxidant activity was observed between fractions of two Dictyota species. Other employed spectrophotometric methods also revealed similar behavior of two Dictyota species, however, somewhat higher activity was observed for both D. dichotoma fractions. The Pearson’s correlation coefficient for SWV versus Folin-Ciocalteu method was a negative value of -0.99 (p

Co- culture systems are lately being explored as a potential replacement for monoculturing of various microorganisms in order to enhance the biomass yield, increase synthesis of described and yet unidentified bioactive compounds. Utilization of microalgae-bacteria co-cultivation has been well documented on wastewater treatment and downstream proccessing such as biomass harvesting. In contrast, very little data is known considering identification of novel metabolites produced only during co- cultivation. This area of research is of particular interest since most of these compounds have a great potential for medical and biotechnological application. Chlorella vulgaris is a model microalgae intensively investigated because of its ability to produce various bioactive compounds benefitial for human health. Streptomycetes are well known bacterial producers of antibiotics, anticancer and immunosupresssors. Abundantly present in soil, they are adapted to various ecological niches. Capacity to produce diverse metabolites is a result of their interaction with various organisms. Streptomyces rimosus G7 is specifically known for its ability of oxytetracycline production.In this study, S.rimosus and C.vulgaris consortium was cultivated in Triptic Soy Broth medium, under mixotrophic conditions. Reugular monitoring of growth curves served to detemine most relevant bioprocess parameters under which these organisms co-existed. Extracted biomass as well as metabolites excreted into the medium were invesitgated in order to determine the significant effects on their metabolomic flux. Determination of biomass composition of both microorganisms has been performed using Nile Red (NR) method with flourescence microscopy for lipid accumulation ; spectrophotometry for pigments and Lowry method for protein yield. Antimicrobial acitvity was tested using agar well diffusion method for detection of antibiotics.Co-culture systems resulted in increased yield of neutral lipids which identification and quantification of the fatty acids content was furtherly studied using gas chromatography (GC). Interestingly, antimicrobial acitvity of S. rimosus was tested using agar well diffusion method showing decreased antibiotic production in co- culture systems. Pigment content also decreased which can be linked to allelochemicals production, while protein composition remained the same.Optimization of bioprocess parameters of the co-culture system was successfully carried out in both Tryptic Soy Agar and Tryptic Soy Broth culture media. The total pigment content of chlorophyll a, b and pheophytin a, b was analysed regularly during co- cultivation. Moreover, the content of neutral lipids in the co- culture of C. vulgaris and S. rimosus (1:100 dilution) showed a significant increase in triolein production, which was 4, 353 mg/mL on the last day of cultivation. These results indicate the potential of co- culture systems for biodiesel production and still need to be confirmed by GC (gas chromatography). Interestingly, the antimicrobial activity assay showed that oxytetracycline was not produced in both C. vulgaris + S. rimosus 1:100 and 1:1000 dilution systems. This specific metabolic shift in co- culture systems will also be further validated by HPLC (high performance liquid chromatography). Metabolites synthesized and released in the culture medium, as well as those embedded in the biomass, will also be analysed by quadrupole time- of-flight (q-TOF) mass spectrometry to reveal the production of new compounds.

Spirulina sp. is a widely cultivated cyanobacteria which contains a high amount of bioactive compounds with health-promoting effects and remarkable antioxidant activity due to the abundant presence of polyphenols and carotenoids. The effect of different drying temperatures (room temperature, 40, 50, 60, 80, and 100°C) on the phenolic profile and biological activity of Spirulina sp. was investigated. Samples were dried at various temperatures, extracted and then fractioned. Antioxidant activity of methanolic (F3) and dichloromethane (F4) fractions was evaluated using ABTS, FRAP, ORAC and DPPH assays. To determine the toxicity potential of prepared fractions, zebrafish embryotoxicity test was performed. Phenolic compounds in Spirulina sp. samples were identified using HPLC, while LC/ MS-Q-TOF screening was used to predict the most probable bioactivities, chemical classes and drug-likeness properties of examined compounds. According to antioxidative assays, F3 fraction had higher ABTS and FRAP activity, while F4 fraction had higher DPPH and ORAC activity. The F4 fraction dried at 50°C showed the highest antioxidant activity using DPPH (687.06 +/- 11.41 mg AAE/g fraction), while ABTS and FRAP assays showed high activity for F3 fractions dried at 25, 30 and 100°C. There was no negative impact on the survival of zebrafish embryos and larvae observed at concentrations lower than 0.02 mg/mL. The most abundant polyphenols were epicatechin, vanillic acid, caffeic acid, diosmin, thymol, apigenin, while the presence of 3 alkanolamines and 25 lipid-like molecules was revealed by QTOF analysis. High antioxidant activity observed at lower temperatures can be related to the presence of carotenoids and chlorophyll. Antioxidant potential of sample dried at 100°C can be attributed to pigment derivatives. The optimal temperature for preservation of polyphenols was 50°C. A strong correlation between structural class of detected compounds and highly predicted activities (cardiovascular, anti-inflammatory, anticancer) has been observed. The results indicate that drying at a lower temperature retains phenols and other components and maintains high antioxidant activity. It can also be concluded that lower drying temperatures better influence the content of phenolic compounds and biological activity of Spirulina sp., when compared to higher temperatures.

Co-culture systems are lately being explored as a potential replacement for monoculturing of various microorganisms in order to enhance the biomass yield, increase synthesis of described and yet unidentified bioactive compounds. Utilization of microalgae-bacteria co- cultivation has been well documented on wastewater treatment and downstream processing such as biomass harvesting. In contrast, very little data is known considering the identification of novel metabolites produced only during co-cultivation. This area of research is of particular interest since most of these compounds have a great potential for medical and biotechnological applications. Streptomycetes are well-known bacterial producers of antibiotics, anticancer and immunosuppressant drugs. Abundantly present in the soil, they are adapted to various ecological niches. The capacity to produce diverse metabolites is a result of their interaction with various organisms. Streptomyces rimosus G7 is specifically known for its ability of oxytetracycline production. Chlorella vulgaris is a model microalgae intensively investigated because of its ability to produce various bioactive compounds beneficial for human health. In this study, oxytetracycline producer S.rimosus and C.vulgaris consortium was investigated in order to determine the most relevant bioprocess parameters showing significant effects on the metabolomic flux of both organisms.

Brown macroalgae have recently been the focus of many research due to their composition and the accumulation of specific metabolites with several health benefits and biological activities. Additionally, the extracts of Halopteris scoparia (HASC) have shown to have protective and preventive activity against human cancer cells. In this study, the evaluation of HASC against harmful ultra-violet (UV) light was done in regard to different activities, namely pigment determination by HPLC analysis, the transmission of erythema (Te) and pigmentation (Tp), along with the calculation of sun protective factor (SPF), antityrosinase and antioxidant activities. Antioxidant activity was also analysed before and after irradiation using UV-B light (8 W, 2000 μW cm−2) for different time periods (30, 60, and 120 minutes). Analysis was performed on two different fractions obtained with the solid-phase extraction (SPE) method, methanolic F3 and dichloromethane F4 fractions, from three different harvesting seasons (February, April, and June 2021). HPLC analysis revealed several pigments in HASC samples. The most abundant were fucoxanthin, lutein, and β-carotene. The highest concentrations were found in the sample from February. Interestingly, the less lipophilic pigments such as fucoxanthin, lutein, astaxanthin, and canthaxanthin, were observed in the F3 fraction, while the F4 fraction contained more lipophilic pigments chlorophyll a and β-carotene. The highest antioxidant activity using DPPH and ABTS assays was also observed for the February sample which could be explained by the presence of pigments such as β-carotene with known activity against free radicals. SPF was high for all HASC samples when compared to a known UV filter Benzophenone-3 (BP-3). % Te and % Tp showed a high protective effect for all samples, with the lowest transmission for HASC from February, especially the F4 fraction which can be attributed to the presence of β- carotene. No significant difference was observed in antioxidant activity after UV-B irradiation for all tested time periods and samples. Only the HASC June samples have shown a slight decrease in antioxidant activity after 120 minutes. Additional chemical characterization of obtained extracts is in progress to further evaluate additional bioactive compounds present in samples that could influence the photostability of these samples and could have applications as natural sun-protective agents.

Spirulina sp. is a widely cultivated microalgae that contains numerous bioactive compounds with health-promoting properties. Phenolic profile and biological activity were investigated in regard to different drying temperatures (25, 40, 50, 60, 80, 100°C). Antioxidant activity (ABTS, FRAP, ORAC, DPPH) of methanolic (F3) and dichloromethane (F4) fractions was evaluated. To assess the toxicity of the fractions, zebrafishembryos were used. Phenolic compounds were identified using HPLC, while prediction of most probable bioactivities, chemical classes, and drug-likeness properties were made using LC/MS-Q-TOF. The F4 (50°C) showed the highest altioxidant activity using DPPH, while ABTS and FRAP showed high activity for F3 (25, 30 and 100°C). No negative impact on the survival of zebrafish was observed at concentrations lower than 0.02 mg/mL. Most abundant polyphenols were epicatechin, vanillic and caffeic acid, while the presence of alkanolamines and lipid-like molecules was revealed by LC/MS-Q-TOF. High antioxidant activity was observed at lower temperatures, due to the presence of carotenoids and chlorophylls, while for the sample dried at 100°C this can be attributed to pigment derivatives. Optimal temperature for preservation of polyphenols was 50°C. A strong correlation between structural class of detected compounds and highly predicted activities (cardiovascular, anti- inflammatory, anticancer) has been observed.

Chlorella vulgaris is a green unicellular that has been subjected to extensive studies within the last decade and has experienced imense applications in food and cosmetic industries [1]. C. vulgaris biomass represents a valuable and sustainable source of numerous bioactive compounds that can positively affect human health, such as proteins, vitamins, polysaccharides, microelements and polyunsaturated fatty acids (PUFA) [2]. Proteins and PUFAs recently gained a special interest of the nutraceutical sector due to their ability to accelerate wound healing, decrease blood pressure and cholesterol levels, but also improve bone health and neurological function [3]. For those reasons, particular focus is placed on the microalgal potential to enhance the nutritional value of conventional foods. Drying harvested microalgae while at the same time preserving all beneficial activities has shown to be a challenging step for the industry. To deepen the knowledge gap, C. vulgaris biomass was dried at different temperatures (lyophilized, 25, 40, 60 and 100), followed by determination of protein, carbohydrate and lipid contents. The highest protein value was observed for C. vulgaris dried at 25°C (58.5377±0.0007% (µg/µg), followed by samples dried at 40°C and 100°C. According to the findings, lower-temperature dried samples had higher levels of chlorophyll a and b, as well as their derivatives pheophytin a and b. The biomass dried at 40°C had the highest amount of carotenoids. The lipid profile determined by gas chromatography analysis showed a predominance of monounsaturated and polyunsaturated fatty acids, in specific essential omega-6 (linoleic acid) and omega-3 (docosahexaenoic acid) fatty acids. The highest total lipid content of C. vulgaris was around 5% for samples dried at 60 and 100°C. The results obtained confirmed C. vulgaris as a microalga with a great potential source of proteins, pigments and essential fatty acids, but also emphasized the importance of optimization of drying techniques.

Brown macroalgae have recently been in the focus of many researches due to their composition and the accumulation of specific metabolites with great antioxidant potential. Food, cosmetics, and pharmaceutical industries are constantly working to find natural, non-toxic compounds that can be used in their products. In this study, we evaluated the antioxidant activity of two (methanolic and dichloromethane) different fractions from three brown macroalgae, Dichtyota dichotoma, Dichtyota fasciola, and Halopteris scoparia. Several methods were used for the evaluation of antioxidant activity including the reduction of the radical cation (ABTS), the 2, 2-diphenyl-1-picryl-hydrazyl (DPPH), the Folin–Ciocalteu, and the oxygen radical absorbance capacity (ORAC) assays. Also, total protein content was determined by the Lowry method with slight modifications, while chlorophyll and carotenoid content were determined spectrophotometrically by the Lichtenthaler method. The toxicity of samples was determined using the zebrafish embryotoxicity test up to 96 h of embryonal development. All methanolic fractions showed higher antioxidant activity than the dichloromethane fractions, while H. scoparia methanolic fraction showed the highest activity (IC50 concentration of 1.947 mg/mL). The highest protein value was observed for Halopteris scoparia (20.7%) followed by Dichtyota dichotoma (7.4%) and Dichtyota fasciola (3.3%). Because of their good antioxidant potential, all three researched brown macroalgae have the potential to be used as a source of natural antioxidants in the cosmetic industry.

Chlorella vulgaris, a green unicellular microalga with numerous biological and pharmacological properties important for human health, was isolated and subjected to different drying conditions in order to determine the effect of applied temperature on phenolic profile and biological activity. The antioxidant activity was investigated by four spectrophotometric methods (ABTS, FRAP, ORAC, DPPH). In terms of anti-aging properties, in vitro collagenase inhibition was determined. The potential toxicity of tested samples was determined by zebrafish embryotoxicity test. Moreover, the qualitative identification of phenolic compounds in each sample was performed using HPLC. By using the ABTS assay, the highest antioxidant activity was observed for lyophilized sample. The same sample exhibited the highest anti-collagenase activity (up to 60.98 % on 0.13 mg/mL). Tested extracts showed no negative impact on the survival of zebrafish embryos. HPLC analysis showed that the lyophilized sample of C. vulgaris contains higher content of phenolic compounds compared to the dried sample. Collectively, both biological and chemical analysis, lyophilized C. vulgaris shows higher polyphenolic content and biological activity compared to dried biomass.

Microalgae and bacteria are part of the vital components of various ecosystems. Photosynthetic microalgae capture solar energy and convert it to bioenergy and biochemical products. They exude dissolved organic carbon that becomes available to bacteria. In return, the bacteria remineralize sulphur, nitrogen and phosphorous to support the further growth of microalgae. Microalgae-bacteria symbiosis represents commensal and mutualistic inter-kingdom relationships, that may result in stimulation of algal growth, but also in the development of new metabolites with a prominent potential for application in the industry sector. Chlorella vulgaris is a green unicellular microalga with numerous biological and pharmacological properties important for human health. Streptomycetes are the most thoroughly studied microorganisms producing biologically active compounds, such as antibiotics, anticancer agents, immunosuppressives, antifungals, etc. In the recent decade, co-cultivation, as a potential replacement for monoculturures of various microorganisms, gained special interest due to a whole range of desirable characteristics, such as modularity, robustness, predictability, scalability and stability. However, very little is known about the significance of S. rimosus and C. vulgaris co-cultures concerning the production of high-value metabolites with anti-bacterial, anti- oxidant, and anti-aging activities. To determine the significance of their co-cultivation, a rangeseries of biological assays were performed on algal and bacterial monocultures, as well as co- culture. The antimicrobial activity of extracts against Gram-positive and -negative bacteria was tested using the microdilution broth method. Extracts from single cultures had dose-dependent inhibitor activity against tested microorganisms, while co-culture extracts showed higher activity compared to extracts from monocultures. Furthermore, the antioxidant activity was investigated by 4 spectrophotometric methods. The highest antioxidant activity was obtained using the ferric reducing antioxidant power assay on algal monoculture and co-cultivation. In terms of anti-aging properties, inhibition of collagenase activity was recorded on S. rimosus monoculture and co-culture. Tested extracts showed no negative impact on the survival/development of zebrafish Danio rerio embryos, which taken together with other results implies their potential for broadening their biotechnological applications.

Arthrospira platensis is a promising and sustainable microalga characterized by easy growth without the need for herbicide or pesticide usage, and the possibility to utilize the whole microalgae without waste and harmful greenhouse gas emissions. It represents a valuable source of bioactive compounds with different health-promoting properties which make A. platensis an attractive ingredient for the formulation of eco-friendly cosmetics. As dehydration is one of the crucial production steps in the cosmetic, pharmaceutic, and food industries, the aim of this work was to investigate the influence of different drying temperatures on the chemical composition of A. platensis. Antioxidant activity of methanol: dichloromethane (1:1) extracts from differently dried (40, 50, 60, 80, and 100°C) samples were analyzed using 2, 2-diphenyl-1-picryl-hydrazyl (DPPH), reduction of the radical cation (ABTS), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. The influence of drying temperature on total protein, carbohydrate, pigment, and lipid content was evaluated, while gas chromatography was carried out to determine fatty acid composition. By implementing ABTS and DPPH methods, the highest antioxidant activity was observed for the sample dried at 40°C followed by 50 and 80°C dried samples with 1.5- and 2.5-fold lower activity (p

The present study was undertaken to evaluate the toxic potential and novel in-vivo antioxidant activity determination of polysaccharide fractions and to complete this research by developing a robust platform for the high-throughput screening of novel marine compounds with antioxidant properties.

Neutronska karotaža je jedna od metoda karotažnih istraživanja kojima mjerimo fizikalna svojstva nabušenih stijena i fluida u porama. To je jedna od metoda izazvane radioaktivnosti. U prirodi ne postoje slobodni neutroni, pa se kao izvori neutrona koriste umjetno izazvane nuklearne reakcije. U svrhu istraživanja ovim metodama koriste se sonde koje koriste brze neutrone ili pulseve brzih neutrona. Metoda se temelji na činjenici da je vodik izrazito učinkovit u usporavanju brzih neutrona, stoga je usporavanje brzih neutrona povezano s postojanjem jezgre vodika u stijeni. Prvo se je mogućnost detekcije vodika u stijeni povezivala s poroznošću stijene, no kasnije je zaključeno da se neutronskom karotažom zapravo ne može mjeriti poroznost s potrebnom točnošću, jer se vodik u stijeni ne nalazi samo u vodi u pornom prostoru, već se može nalaziti i u zaglinjenim naslagama, koje povećavaju izmjerenu poroznost. Također, mjerenje poroznosti pomoću detekcije vodika je jako otežano u sloju zasićenom plinom, koji će dati manje vrijednosti poroznosti zbog male koncentracije vodika. Danas se neutronska karotaža koristi za procjenu vodikovog indeksa (HI) i za otkrivanje slojeva zasićenih plinom. Neutronska karotaža može se primjenjivati i u nezacijevljenim i u zacijevljenim bušotinama, no za mjerenja u zacijevljenim bušotinama potrebno je koristiti posebne sonde koje mogu dati kvalitetniju sliku o svojstvima stijene i pornog fluida koji se nalazi iza zaštitnih cijevi.

Rad ne sadrži sažetak.

Koronarna bolest srca vodeći je uzrok smrtnosti kako u većini europskih zemalja, tako i u Hrvatskoj. Akutni infarkt miokarda među najčešćim je pojedinačnim dijagnozama i u mortalitetu i bolničkom morbiditetu, te predstavlja značajan javnozdravstveni problem, kako zbog učestalosti, tako i posljedica. Nastaje zbog začepljenja koronarne arterije i nekroze tkiva u području prekida dovoda krvi. Začepljenje najčešće nastaje zbog aterosklerotskih promjena krvnih žila. Nakon preboljele bolesti srca, promjena stila života smatra se važnom za sprečavanje i smanjenje kardiovaskularnih bolesti. Kardiološka rehabilitacija usmjerena je na potencijalne promjene načina života. Cilj joj je promjena kardiovaskularnih čimbenika rizika kroz prehrambene promjene, prestanak pušenja, tjelovježbu i psihosocijalnu podršku. Medicinska sestra ima važnu ulogu u procesu promjene nezdravoga životnog stila kod pacijenata nakon nedavnoga kardiološkog događaj. Rehabilitacija bolesnika s akutnim koronarnim sindromom započinje u akutnoj fazi i nastavlja se dok bolesnik ne bude osposobljen za rad ili napore koji su dovoljni za obavljanje lakših dnevnih aktivnosti, tj. za samozbrinjavanje. Za uspjeh kardiološke rehabilitacije važno je da medicinska sestra posjeduje specifična znanja i alate za procjenu i rad u kliničkoj praksi, kao i biti samo-kritična i poslužiti kao pozitivan uzor. CILJ: Prikazati važnost promjene životnog stila nakon preboljelog akutnog infarkta miokarda te ulogu medicnske sestre kao člana multidisciplinarnog tima u rehabilitacijskim programima. Coronary heart disease is the leading cause of mortality in most European countries, including Croatia. Acute myocardial infarction among the most common individual diagnoses and mortality and hospital morbidity is a significant public health problem due to its frequency and its consequences. It is caused by blockage of coronary arteries and necrosis of tissue in the area of blood interruption. Clogging usually occurs due to atherosclerotic changes in blood vessels. After overcoming heart disease, lifestyle changes are considered important for the prevention and reduction of cardiovascular disease. Cardiological rehabilitation focuses on potential lifestyle changes. Its goal is to change cardiovascular risk factors through nutritional change, smoking cessation, exercise and psychosocial support.A nurse has an important role in the process of changing unhealthy lifestyle in patients after a recent cardiac event. Rehabilitation of patients with acute coronary syndrome begins at an acute stage and continues until the patient is trained for work or efforts that are sufficient to carry out easier day-to-day activities, is self-refreshment. For the success of cardiologic rehabilitation it is important that the nurse possesses specific knowledge and tools for evaluation and work in clinical practice, as well as being self-critical and serving as a positive model. AIM: To demonstrate the importance of lifestyle change after the acute myocardial infarction and the role of the nurse as a member of the multidisciplinary team in rehabilitation programs.

The paper is based on the assumption that each consumer individually creates the expected value of a service. Confirmation of expectations can be viewed through the difference between the expected and perceived value for the customer. Thus, a perceived value for customers is the difference between all the benefits and all drawbacks of the offer and the possible alternatives considered and assessed by them. Therefore, the main goal of the study is to examine the attitudes of the respondents about the importance/performance of services provided by business hotels. For this purpose, Importance- Performance Analysis was applied to explore the importance the respondents give to certain service elements (Importance), as well as their satisfaction with them (Performance). The data was collected by a survey conducted from July- September, 2017 and the answers of 61 respondents were obtained. Finally, the results are presented in the Coordinate System of the Importance/Performance Matrix with the goal of defining strong and weak points of the services in business hotels. The main findings indicate that factor Reliability is the most important for guests and Tangibility is the least important. Regarding performance, the results are quite similar, with Reliability being the highest rated and Tangibility the lowest. Thus, the Reliability is the only factor in the matrix positioned in the quadrant Concentrate here, while there are no factors in the field Possible Overkill, which is an encouraging finding. The position of the other dimensions and the ratings of all items are discussed in the paper in the light of the practical implications.

Skrb za osobe s traumatskom ozljedom glave