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Heat shock proteins in tumorigenesis
No full textProteini toplinskog šoka (HSP) su molekularni šaperoni koji održavaju proteostazu i
štite stanice od nepovoljnih uvjeta kao što su toplinski šok, oksidativni stres ili hipoksija. U normalnim fiziološkim uvjetima sudjeluju u savijanju proteina i regulaciji staničnog ciklusa. U tumorskim stanicama, HSP-i stabiliziraju onkoproteine, sprječavaju apoptozu i potiču proliferaciju i migraciju, podržavajući rast i migraciju tumora.Heat shock proteins (HSP) are molecular chaperones that maintain proteostasis and protect cells from adverse conditions such as heat shock, oxidative stress or hypoxia. Under normal physiological conditions, they participate in protein folding and regulation of the cell cycle. In tumor cells, HSPs stabilize oncoproteins, inhibit apoptosis and promote proliferation and migration, supporting tumor growth and spread
Chemical composition of natural perfumes
No full textPrirodni parfemi temelje se na složenim smjesama hlapljivih organskih spojeva koji
biljci daju karakterističan miris. Glavne kemijske skupine koje su odgovorne za formiranje mirisnih nota uključuju terpene (limonen, pinen), terpenoide (linalool, geraniol), estere (linalil-acetat, benzil-acetat), aldehide, ketone, prirodne alkohole i fenolne kiseline. Svaka od skupina doprinosi specifičnim mirisnim svojstvima, a ujedno pokazuje i određene biološke učinke, među kojima se ističe antioksidacijsko i antimikrobno djelovanje. U suvremenoj proizvodnji prirodnih parfema ključnu ulogu imaju eterična ulja, koja se dobivaju iz različitih dijelova biljke (list, cvijet, plod, sjemenke i korijen). Posebna važnost posvećuje se kvaliteti i standardizaciji eteričnih ulja jer upravo ona određuju konačnu stabilnost i postojanost mirisne note parfema.
Tijekom povijesti, proizvodnja prirodnih parfema se mijenjala. U najranijim vremenima koristili su se kruti mirisni materijali poput smole i drva, koji su se spaljivanjem pretvarali u mirisni dim s religijskim i ljekovitim značenjem. Razvojem kemije i tehnologije postupno su uvedene metode izdvajanja mirisnih komponenti, što je omogućilo proizvodnju tekućih parfema visoke čistoće i raznovrsnih mirisnih profila.Natural perfumes are based on complex mixtures of volatile organic compounds that give plants their characteristic scent. The main chemical groups responsible for the formation of fragrance notes include terpenes (limonene, pinene), terpenoids (linalool, geraniol), esters (linalyl acetate, benzyl acetate), aldehydes, ketones, natural alcohols, and phenolic acids. Each group contributes to specific aromatic properties while also exhibiting certain biological effects, most notably antioxidant and antimicrobial activity. In modern natural perfumery, essential oils play a central role, and are obtained from various plant parts (leaf, flower, fruit, seeds, and root). Special importance is placed on the quality and standardization of essential oils, as they determine the final stability and persistence of a perfume’s fragrance note. Throughout history, the production of natural perfumes has evolved. In the earliest times, solid aromatic materials
such as resins and woods were used, which, when burned, transformed into fragrant smoke with religious and medicinal significance. With the development of chemistry and technology, methods of extracting aromatic components were gradually introduced, enabling the production
of liquid perfumes of high purity and diverse fragrance profiles
Assessment of boron concentrations in biological samples of the inhabitants of Eastern Croatia
No full textBor je bioaktivni element u nutritivnim količinama koji ima pozitivan učinak na rast
kostiju i funkciju središnjeg živčanog sustava, smanjuje simptome artritisa, povećava aktivnost hormona i povezuje se sa smanjenim rizikom za neke vrste raka. Bor utječe na metabolizam nekoliko enzima i minerala. Referentne vrijednosti su od iznimne važnosti jer razine ispod ili iznad referentnog raspona obično ukazuju na nedostatak ili prekomjernu izloženost određenom izvoru. Nedostatak informacija o koncentraciji bora u ljudskom organizmu stanovnika Hrvatske otežava brzu procjenu zdravstvenih rizika povezanih s izloženošću ovom elementu ili njegovim nedostatkom. U tu svrhu u ovome su radu analizirane koncentracije bora u biološkim uzorcima (kosa, urin, serum) 499 stanovnika iz jedanaest naselja (Vladislavci, Dalj, Čepin, Našice, Osijek, Vukovar, Vinkovci, Slavonski Brod, Voćin, Čačinci, Velika) istočne Hrvatske.
Koncentracije bora analizirane su metodom ICP-MS. Usporedba dobivenih rezultata (kosa 0,55 – 21,88 μg/g, urin 193,87 – 1.226,99 μg/L, serum 10,83 – 42,68 μg/L) s vrijednostima određenima na područjima na kojima stanovništvo nije bilo izloženo antropogenim utjecajima, pokazala je da nema značajnijih odstupanja u koncentracijama bora u biološkim uzorcima populacije istočne Hrvatske.Boron is a bioactive element in nutritional amounts that has a positive effect on bone growth and central nervous system function, reduces symptoms of arthritis, increases hormone activity, and is associated with a reduced risk of certain types of cancer. Boron influences the metabolism of several enzymes and minerals. Reference values are of utmost importance
because levels below or above the reference range usually indicate a deficiency or excessive exposure to a certain source. The lack of information on boron concentrations in the human body of the Croatian population makes it difficult to quickly assess health risks associated with
exposure to this element or its deficiency. For this purpose, this study analyzed boron concentrations in biological samples (hair, urine, serum) of 499 residents from eleven settlements (Vladislavci, Dalj, Čepin, Našice, Osijek, Vukovar, Vinkovci, Slavonski Brod, Voćin, Čačinci, Velika) in Eastern Croatia. Boron concentrations were analyzed using the ICPMS
method. Comparison of the obtained results (hair 0.55–21.88 μg/g, urine 193.87–1,226.99 μg/L, serum 10.83–42.68 μg/L) with values determined in areas where the population was not exposed to anthropogenic influences showed no significant deviations in boron concentrations in the biological samples of the Eastern Croatian population
Mechanochemical synthesis of Schiff bases derived from terephthalic acid dihydrazide
No full textCilj ovog diplomskog rada je doprinjeti zelenoj sintezi Schiffovih baza. Najčešći način kojim se sintetiziraju Schiffove baze uključuju dulje zagrijavanje i korištenje velike količine otapala. Mehanokemijskom sintezom u kugličnom mlinu dobivene su četiri Schiffove baze sintetizirane iz dihidrazida tereftalne kiseline i četiri različita aldehida; salicilaldehida, ortho-vanilin, 3-hidroksibenzaldehid te 4-hidroksibenzaldehid. Prvi korak u pripravi je sinteza etilnog estera tereftalne kiseline iz tereftalne kiseline i etanola. U drugom koraku je sintetiziran dihidrazid tereftalne kiseline iz estera tereftalne kiseline i hidrazida, koji je zatim korišten u trećem koraku za mehanokemijsku sintezu Schiffovih baza. Mehanokemijskom metodom dobivene su manje količine Schiffovih baza koje su analizirane FT-IR spektroskopijom.The aim of this thesis is to synthesize Schiff bases using green chemistry approach. The most common methods for synthesizing Schiff bases involve prolonged heating and the use of large amounts of solvent. Mechanochemical synthesis in a planetary ball mill was done to obtain 4 Schiff bases from terephthalic acid dihydrazide and 4 different aldehydes: salicylaldehyde, ortho-vanillin, 3-hydroxybenzaldehyde and 4-hydroxybenzaldehyde. The first step is the synthesis of terephthalic acid
ethyl ester from terephthalic acid and ethanol. In the second step, terephthalic acid dihydrazide is synthesized from terephthalic acid ester and hydrazide, which will then be used in the third step for the synthesis of Schiff bases with a particular aldehyde. By using mechanochemical synthesis, a small amount of 4 novel Schiff bases was obtained and characterized by FTIR spectroscopy
The influence of praseodymium on the structure of high-entropy oxides
No full textU ovom diplomskom radu proučavan je utjecaj praseodimija (Pr) na strukturu
visokoentropijskih oksida. Serija spojeva sintetizirana je modificiranom sol-gel metodom, s postupnim povećanjem udjela praseodimija. Dobiveni uzorci okarakterizirani su metodama PXRD, FTIR, TGA, SEM-EDS i BET analizom. Rezultati su pokazali da svi spojevi kristaliziraju u strukturi tipa fluorita prostorne grupe Fm-3m, te utjecaj udjela Pr na mikrostrukturne parametre. IR spektroskopija potvrdila je prisutnost karakterističnih vibracija oksidnih sustava, dok je TG analiza ukazala na visoku toplinsku stabilnost. SEM-EDS analiza potvrdila je homogenu raspodjelu elemenata i očuvanje površinske morfologije, a BET analiza ukazala na mezoporoznu
prirodu uzoraka i određene su specifične površine sintetiziranih spojeva. Dobiveni rezultati pokazuju da uvođenje praseodimija ne narušava stabilnost strukture visokoentropijskih oksida, već doprinosi strukturnim promjenama koje mogu povoljno ili nepovoljno utjecati na potencijalnu primjenu.In this master’s thesis, the influence of praseodymium (Pr) on the structure of highentropy oxides was investigated. A series of compounds was synthesized using a modified sol-gel method with a gradual increase in praseodymium content. The samples were characterized by PXRD, FTIR, TGA, SEM-EDS, and BET analyses. Results showed that all compounds
crystallized in the fluorite-type structure of the space group Fm-3m, with praseodymium content affecting microstructural parameters. IR spectroscopy confirmed the presence of characteristic oxide vibrations, while TG analysis indicated high thermal stability. SEM-EDS confirmed a
homogeneous elemental distribution and preserved surface morphology, whereas BET revealed the mesoporous nature of the samples and their specific surface areas. The findings demonstrate that introducing praseodymium does not compromise the structural stability of high-entropy oxides but contributes to structural modifications that may influence potential applications
Design and preparation of novel fluorescent probe for selective H2S determination
No full textU sklopu ovog diplomskog rada opisana je priprava fluorescentne probe koja će se u
nastavku istraživanja koristiti u svrhu detekcije H2S u biološkom uzorku, primarno u ljudskom serumu. Struktura ciljne fluorescentne probe, spoja 2, sastoji se od 1,8-naftalimida kao fluorofora, azidne skupine kao kemijski reaktivnog mjesta za H2S te 2-aminopropan-1,3-diola (serinola) kao podjedinice odgovorne za povećanje topljivosti u vodi. Ciljna fluorescentna proba, spoj 2, u okviru ovoga rada pripravljena je u dva reakcijska koraka. Prvi korak podrazumijevao je uvođenje azidne skupinu u strukturu polaznog 4-brom-1,8-naftalanhidrida, dok je drugi korak uključio prevođenje azidnog derivata 1 u imidni derivat, reakcijom sa odabranim aminom, serinolom. U okviru rada, osnovnu naftalimidnu strukturu pokušalo se modificirati i uvođenjem druge hidrofilne podjedinice, D-glukozamina. Za navedenu reakciju predložena su dva sintetska puta. Nadalje, u osnovnu naftalimidnu strukturu, pokušala se uvesti i 2,4-dinitrobenzensulfonilna podjedinica s ciljem uvođenja novog kemijski reaktivnog mjesta za H2S. Strukture svih ciljnih produkata i međuprodukata pretpostavljene su 1H i/ili 13C NMR spektroskopijom.In this diploma thesis the synthesis of a fluorescent probe for the detection of H₂S in biological samples, primarily human serum, is described. The structure of the fluorescent probe, compound 2, consists of a 1,8-naphthalimide fluorophore, an azide group as a chemically reactive site for H₂S, and 2-aminopropane-1,3-diol (serinol) as a subunit responsible for
enhancing water solubility. The target fluorescent probe, compound 2, was synthesized in two reaction steps. The first step involved the addition of the azide group into the structure of the starting compound, 4-bromo-1,8-naphthalic anhydride, while the second step implied the conversion of the azide derivative 1 into the corresponding imide derivative via reaction with
the selected amine, serinol. In this study, attempts were also made to modify the basic naphthalimide structure by introducing another hydrophilic subunit, D-glucosamine. Two synthetic routes were proposed for this reaction. Additionally, the synthesis of a 2,4-
dinitrobenzenesulfonyl-functionalized naphthalimide derivative was explored to provide a new chemically reactive site for H₂S. The structures of all synthesized products were characterized with 1H and/or 13C NMR spectroscopy
Solvatomorphism of pyridine-2,6-dicarboxylic acid hydrazide quinazoline derivative
No full textsintetiziranog kondenzacijom hidrazina piridin-2,6-dikarboksilne i kinazolinskog derivata u eutektičkoj smjesi kolin-klorida i uree. Kristalizacijom iz metanola, etanola, izopropanola i n-butanola dobiveni su četiri različita solvatna oblika: L•MeOH, L•EtOH, L•iPrOH i L•ButOH. Strukturna i termička karakterizacija provedene su metodama SCXRD, PXRD, TGA/DSC. Svi spojevi kristaliziraju u monoklinskom kristalnom sustavu, no pokazuju različite omjere domaćin:gost, raspored otapala i vrste međumolekulskih interakcija. L•ButOH ima najveću termičku stabilnost, najjače vodikove veze i π···π interakcije, dok L•MeOH ima najjednostavniju strukturu i najslabije vezano otapalo. Svi spojevi transformiraju se zagrijavanjem u istu nesolvatnu fazu, što ukazuje na zajednički termodinamički stabilan oblik. Ovi rezultati naglašavaju važnost izbora otapala u kristalnom inženjeringu te pružaju uvid u dizajn materijala s kontroliranim svojstvima kroz solvatomorfizam.This thesis investigates the solvatomorphism of a quinazoline-based derivative of dipicolinic acid hydrazide (H2L), synthesized via condensation of pyridine-2,6-dicarbohydrazine and a quinazoline precursor in a deep eutectic solvent mixture of choline chloride and urea. Crystallization from methanol, ethanol, isopropanol, and n-butanol yielded four distinct solvates: L•MeOH, L•EtOH, L•iPrOH, and L•ButOH. The structural and thermal characterization was performed using SCXRD, PXRD, and
TGA/DSC techniques. All compounds crystallize in the monoclinic system and exhibit differences in host: guest ratio, solvent arrangement, and intermolecular interactions. L•ButOH displayed the highest thermal stability and the most extensive hydrogen bonding and π···π stacking interactions, while L•MeOH was the simplest structure with the lowest solvent retention. Upon heating, all solvates converted into the same anhydrous form, indicating a common thermodynamically stable phase. These results highlight the importance of solvent selection in crystal engineering and provide insight into the design of materials with tailored properties via solvatomorphism
Assessment of cooper in biological samples of inhabitants of Eastern Croatia
No full textRad je proveden s ciljem procjene koncentracije bakra (Cu) u biološkim uzorcima (serumu, urinu i kosi) stanovnika istočne Hrvatske. Koncentracije bakra određene su metodom ICP-MS (induktivno spregnuta plazma - masena spektrometrija), a dobiveni rezultati su analizirani metodama osnovne statistike i klaster analizom. Većina vrijednosti koncentracije bakra u serumu, urinu i kosi 594 ispitanika s 11 različitih lokacija isto ne Hrvatske, bila je unutar vrijednosti dobivenih na područjima koja nisu bila izložena antropogenim utjecajima. Zabilježene su i manje razlike unutar istraživanih lokacija. Rasponi medijana koncentracija bakra iznosili su: u serumu 744,4 - 1022,23 μg/L, u urinu 6,49 - 28,98 μg/L i kosi 6,2 - 23,57 μg/g.The study was conducted with the aim of assessing copper (Cu) concentrations in biological samples (serum, urine, and hair) of residents from eastern Croatia. Copper concentrations were determined using the ICP-MS method (Inductively Coupled Plasma - Mass Spectrometry), and the obtained results were analyzed using basic statistical methods and cluster analysis. Most of the copper concentration values in serum, urine, and hair of 594 participants from 11 different locations in eastern Croatia were within the range of values observed in areas not exposed to anthropogenic influences. Minor differences were also recorded among the investigated locations. The ranges of median copper concentrations were as follows: in serum 744.4 - 1022.23 μg/L, in urine 6.49 - 28.98 μg/L, and in hair 6.2 - 23.57 μg/g
Theobromine
No full textTeobromin je metilksantin koji se prirodno nalazi u kakaovcu (Theobroma cacao L.) i proizvodima dobivenim iz njegovog ploda. Osim što djeluje blago stimulativno, teobromin ima niz potencijalno korisnih učinaka na ljudsko zdravlje, poput regulacije krvnog tlaka, poticanja rada srca i djelovanja kao diuretik. U ovom radu određivana je koncentracija teobromina u uzorcima kakao praha, kakao zrna i tamne čokolade s 85% kakaa, kako bi se utvrdilo u kojem uzorku se nalazi najveća količina teobromina.
Za određivanje koncentracije korištena je tekućinska kromatografija visoke djelotvornosti s UV-VIS detekcijom. U sklopu rada provedena je optimizacija postupka uklanjanja masnoće i ekstrakcije teobromina, pri čemu se najučinkovitijom pokazala ekstrakcija potpomognuta direktnim ultrazvukom. Dobiveni rezultati pokazali su da je najveća koncentracija teobromina izmjerena u uzorcima kakao praha
31,010 mg/g, zatim u kakao zrnu 24,836 mg/g, a najniža koncentracija utvrđena je u tamnoj čokoladi i iznosila je 15,609 mg/g. Provedenim istraživanjem pokazano je da optimirana metoda uklanjanja masnoća kao i prilagođena metoda kvantificiranja teobromina u realnim uzorcima osiguravaju rezultate koji su u skladu s literaturnim podacima.Theobromine is a methylxanthine naturally found in cocoa (Theobroma cacao L.) and cocoaderived products. In addition to its mild stimulant properties, theobromine has several potentially beneficial effects on human health, such as regulating blood pressure, stimulating heart function, and acting as a diuretic. In this study, the concentration of theobromine was determined in samples of cocoa powder, cocoa beans and dark chocolate containing 85% cocoa, in order to identify the sample with the highest theobromine content. High Performance Liquid Chromatography with UV-VIS detection was used for quantitative determination. As part of the study, the procedure for fat removal and theobromine extraction was optimized, with ultrasound-assisted direct extraction proving to be the most efficient method. The results obtained showed that the highest concentration of theobromine measured in cocoa
powder samples was 31,010 mg/g, followed by cocoa beans at 24,836 mg/g, and the lowest concentration was determined in dark chocolate at 15,609 mg/g. The conducted research has shown that the optimized fat removal method, as well as the adapted method for quantifying theobromine in real samples, provide results that are consistent with the literature data
Development of the potentiometric sensor based on molecularly imprinted polymer for determination of thiabendazole
No full textTiabendazol (TBZ) je organski spoj širokog spektra upotrebe u poljoprivredi i
medicini. To je fungicid koji se često koristi za zaštitu voća i povrća od gljivičnih infekcija tijekom skladištenja. Kako ga ljudi zbog široke upotrebe unose hranom, s vremenom se razvijaju nove metode radi lakšeg i bržeg određivanja u uzorcima. Cilj ovog rada bio je razviti potenciometrijski senzor za određivanje TBZ-a koji koristi molekularno utisnuti polimer (MIP) kao selektivni materijal unutar membrane senzora. Određivanje je provedeno metodom direktne potenciometrije. Prilikom optimizacije membrane senzora, varirani su postotak senzorskog materijala i vrsta plastifikatora. Najbolja svojstva postignuta su senzorom koji sadrži dibutil-ftalat i 10 % MIP-a. Takav senzor pokazao je nagib od 60,8 mV dekada aktiviteta-1, granicu detekcije od 3,2⋅10⁻⁷ mol dm-3, široko mjerno područje (6,2⋅10⁻⁷ –1,0⋅10⁻³ mol dm-3), brzi odziv od 6 s te stabilan odziv s promjenom potencijala od 1,4 mV h-1. S obzirom na visoku selektivnost, senzor je omogućio precizno i točno određivanje TBZ-a u standardnim otopinama i uzorcima voća. Dobiveni rezultati potvrđuju njegovu primjenjivost u kontroli ostataka pesticida u realnim uzorcima.Thiabendazole (TBZ) is an organic compound with a wide range of applications in agriculture and medicine. It is a fungicide commonly used to protect fruits and vegetables from fungal infections during storage. As people ingest it through food due to its widespread use, new methods are being developed over time for the easier and faster determination of its
presence in samples. The aim of this work was to develop a potentiometric sensor for the determination of TBZ that uses a molecularly imprinted polymer (MIP) as a selective material within the sensor membrane. The determination was carried out by the method of direct potentiometry. When optimizing the membrane, the percentage of sensor material and the
type of plasticizer were varied. The best properties were achieved with a sensor containing dibutyl phthalate and 10% MIP. This sensor exhibited a slope of 60.8 mV decade of activity-1, a detection limit of 3.2⋅10⁻⁷ mol dm-3, a wide measuring range (6.2⋅10⁻⁷ – 1.0⋅10⁻³ mol dm-3), a fast response of 6 s, and a stable response with a potential drift of 1.4 mV h-1. Due to its high selectivity, the sensor enabled precise and accurate determination of TBZ in standard solutions and fruit samples. The obtained results confirm its applicability in the monitoring of pesticide residues in real samples