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Investigation of seasonal variations of air pollutants in the area of Central Slavonia
No full textOnečišćenje zraka dušikovim oksidima (NOX), sumporovim dioksidom (SO2) i
lebdećim česticama predstavlja jedan od glavnih ekoloških i zdravstvenih problema u Europi i svijetu. U ovom diplomskom radu istražene su sezonske varijacije koncentracija dušikova dioksida, sumporovog dioksida i lebdećih čestica PM10 na području središnje Slavonije u razdoblju od 2019. do 2024. godine, prema javno dostupnim podacima izmjerenim na mjernoj postaji Zoljan. Analiza podataka uključivala je deskriptivnu statistiku, Kruskal-Wallis test i Fourierovu analizu. Rezultati su pokazali izraženu sezonalnost koncentracija za sva tri polutanta koje su bile značajno veće u zimskim mjesecima od onih u ljetnim mjesecima. Uočeno je kako
NO2 i SO2 pokazuju trend smanjenja koncentracija, a PM10 ne pokazuje jasan trend, već stabilne koncentracije s povremenim porastima, najčešće povezanim sa sezonom grijanja i spaljivanja biomase s poljoprivrednih površina. Uloga fotolize i stvaranje prizemnog ozona naglašena je kod NO2, dok je za SO2 i PM10 poveznica prestanak sezone grijanja i povoljniji uvjeti disperzije. Rezultati istraživanja potvrdili su značaj kontinuiranog praćenja kvalitete zraka u svrhu smanjenja emisija onečišćujućih tvari u zrak i očuvanja okoliša.Air pollution by nitrogen oxides (NOX), sulfur dioxide (SO2) and particulate matter is one of the main environmental and health problems in Europe and the world. This thesis investigated seasonal variations in nitrogen dioxide, sulfur dioxide and particulate matter PM10 concentrations in the area of central Slavonia in the period from 2019 to 2024, according to publicly available data measured at the Zoljan measuring station. Data analysis included descriptive statistics, Kruskal-Wallis test and Fourier analysis. The results showed a pronounced seasonality of concentrations for all three pollutants, which were significantly higher in the winter months than in the summer months. It was observed that NO2 and SO2 show a decreasing trend in concentrations, while PM10 does not show a clear trend, but stable concentrations with occasional increases, most often associated with the heating season and biomass burning from agricultural areas. The role of photolysis and ground-level ozone formation is emphasized for NO2, while for SO2 and PM10 the link is the end of the heating season and more favorable dispersion conditions. The research results confirmed the importance of continuous air quality monitoring for the purpose of reducing air pollutant emissions and preserving the environment
Interactions between the lysine derivative of desmuramyl-peptide and the NOD2 receptor
No full textNOD2 receptor spada u skupinu receptora za prepoznavanje patogena te kao takav ima važnu ulogu u imunosnom sustavu živih bića. Na njega se primarno vežu peptidoglikani, fragmenti bakterijskog staničnog zida. Najmanja jedinica potrebna za aktivaciju NOD2 zove se desmuramil-peptid (DMP). Derivati DMP istražuju se kao potencijalni imunomodulatori koji se mogu koristiti kao adjuvanti cjepivima ili protutumorski agensi. U radu je sintetiziran i istražen jedan takav derivat. Radi se o lizinskom derivatu DMP sa inkorporiranom adamantanskom skupinom. Vezanje
dobivenog spoja na NOD2 receptor računalno je modelirano metodom molekulskog uklapanja, a rezultati su analizirani u PyMol-u te uspoređeni sa vezanjem literaturno poznatih liganda. Na temelju rada napravljen je nastavni sat za učenike 4. razreda srednje škole obzirom na kurikulum i gradivo potrebno za državnu maturu.The NOD2 receptor is one of many pathogen recognition receptors and as such it has a vital role in the immune system of living organisms. It primarily binds peptidoglycans, fragments of the bacterial cell wall. The smallest such fragment is called desmuramyl-peptide (DMP).
Derivatives of DMP are being researched as potential immune system modulators witch can be used as adjuvants in vaccines or as anti-cancer agents. This thesis includes the synthesis of one such derivative, the lysine derivative of DMP with an incorporated adamantane group. The binding
of that compound was computationally modeled by docking. Results were analysed in PyMol and compared to the binding of known ligands. This work was the basis for creating a lesson for fourth grade highschool students with regards to their curriculum and material needed for their state
exams
Preparation and structural characterization of fluorescent probe for NO detection
No full textU okviru ovog završnog rada opisana je priprava derivata naftalimida. Ciljni produkt, spoj 3, pripravljen je u tri reakcijska koraka. Prvi korak podrazumijevao je reakciju komercijalno dostupnog, 4-brom-1,8-naftalanhidrida s 2-nitro-p-fenilendiaminom što je rezultiralo pripravom imidnog derivata, spoja 1. 2-nitro-p-fenilendiamin odabran je kao aminski derivat za adicijsko-eliminacijsku reakciju polaznog derivata 4-brom-1,8-naftalanhidrida s ciljem konverzije u odgovarajući imidni derivat. Na ovaj način generira se potencijalno mjesto za reakciju s NO. U strukturu spoja 1, uvedena je 2-aminopropan-1,3-diolna podjedinica s ciljem povećanja topljivosti ciljnog produkta, odnosno s ciljem priprave spoja 2. Spoj 2, imidni derivat, u svojoj strukturi posjeduje vicinalne amino i nitro skupinu. Korištenjem hidrazin-hidrata kao reducensa i Raney nikla kao katalizatora, uspješno je provedena redukcija nitro skupine u amino skupinu, odnosno pripravljen je spoj 3. Spoj 3, s dvije vicinalne amino u svojoj strukturi poslužit će kao fluorescentna proba za detekciju NO u biološkim sustavima. Strukture svih pripravljenih spojeva pretpostavljene su 1H i/ili 13C NMR spektroskopijom.In this thesis, the preparation of naphthalimide derivatives is described. The target product, compound 3, was synthesized in three reaction steps. The first step involved the reaction of commercially available 4-bromo-1,8-naphthalic anhydride with 2-nitro-p-phenylenediamine, resulting in the formation of the imide derivative, compound 1. 2-nitro-p-phenylenediamine was chosen as the amine derivative for the addition-elimination reaction with the starting compound, 4-bromo-1,8-naphthalic anhydride, in order to convert it into the corresponding imide derivative. This generates a potential site for reaction with NO. Into the structure of compound 1, a 2-aminopropane-1,3-diol moiety was introduced with the purpose of increasing the solubility of the target product, specifically for the preparation of compound 2. Compound 2, an imide derivative, contains vicinal amino and nitro groups in its structure. By using hydrazine hydrate as a reducing agent and Raney nickel as a catalyst, successful reduction of the nitro group to an amino group was achieved, resulting in the formation of compound 3. Compound 3, containing two vicinal amino groups in its structure, will serve as a fluorescent probe or the detection of NO in biological systems. The structures of all synthesized compounds were assumed by ¹H and/or ¹³C NMR spectroscopy
Preparation and characterization of macrocyclic compounds with pyridine-2,6-dicarboxylic acid hydrazide
No full textCilj ovog diplomskog rada je pripraviti nove makrocikličke spojeve koriste i hidrazidni derivat piridin-2,6-dikarboksilne kiseline i aromatske dialdehide kao polazne reaktante. Sinteza cikličkog hidrazidnog derivata provodi se u tri koraka, gdje je prvi korak esterifikacija u kojoj sudjeluju piridin-2,6-dikarboksilna kiselina i etanol. U drugom koraku dietilpiridin-2,6-dikarboksilat reagira s molekulama hidrazina pri emu nastaje hidrazidni derivat dipikolinske kiseline i na posljetku, u trećem koraku, dolazi do stvaranja finalnog makrocikličkog spoja reakcijom hidrazidnog derivata dipikolinske kiseline i aromatskih dialdehida u etanolu. Struktura i svojstva novonastalih makrocikličkih spojeva određena su 1H NMR, MS i FT-IR spektroskopijom. U ovom radu uspješno su dobivena i identificirana četiri nova makrociklička spoja.The aim of this thesis is to prepare new macrocyclic compounds using the hydrazide derivative of pyridine-2,6-dicarboxylic acid and aromatic dialdehydes as starting reactants. The synthesis of cyclic hydrazide derivative is carried out in three steps, where the first step involves esterification of pyridine-2,6-dicarboxylic acid acid and ethanol. In the second step, diethylpyridine-2,6-dicarboxylate reacts with hydrazine molecules, resulting in the formation of the hydrazide derivative of pyridine-2,6-dicarboxylic acid, and finally, in the third step, the formation of the final macrocyclic compound occurs by the reaction of the hydrazide derivative of pyridine-2,6-dicarboxylic acid and aromatic dialdehydes in ethanol. Structure and properties of the newly formed macrocyclic compounds have been characterized using 1H NMR, MS, and FT-IR spectroscopy. In this thesis, four new macrocyclic compounds were successfully obtained and identified
Application of differential pulse voltammetry in detection of antioxidants
No full textU ovom završnom radu ispitivana su elektrokemijska svojstva p-kumarinske, 3,4-dihidroksibenzojeve i galne kiseline, koje pripadaju skupini fenolnih spojeva poznatih po svom snažnom antioksidativnom djelovanju, a koji se u novije vrijeme sve više istražuju zbog svojih pozitivnih učinaka na zdravlje ljudi. Analiza ovog istraživanja je provedena primjenom elektrokemijske metode diferencijalne pulsne voltametrije s ciljem detekcije oksidacije navedenih antioksidansa te ispitivanja utjecaja njihove koncentracije na visinu oksidacijskog strujnog vrha. Eksperimenti su izvedeni korištenjem troelektrodnog sustava koji se sastojao od radne elektrode od staklastog ugljika, Ag/AgCl referentne elektrode i platinske protuelektrode. Prije svakog mjerenja, elektrokemijska ćelija bila je propuhivana argonom visoke čistoće (99,999 %) kako bi se uklonio otopljeni kisik. Rezultati su pokazali da svi analizirani spojevi oksidiraju pri određenim uvjetima te da postoji linearna povezanost između njihove koncentracije i visine oksidacijskog strujnog vrha. Metoda standardnog dodatka korištena je za potvrdu prisutnosti antioksidansa u modelnim otopinama. Također su analizirani realni uzorci - čaj od šipka i zeleni čaj, u kojima je potvrđena prisutnost galne kiseline. Dobivene koncentracije galne kiseline u realnim uzorcima iznosile su 2,72×10⁻⁵ mol dm⁻³ u čaju od šipka i 6,09×10⁻⁵ mol dm⁻³ u zelenom čaju, što potvrđuje primjenjivost korištene metode u analizi složenih uzoraka.In this final thesis, the electrochemical properties of p-coumaric acid, 3,4-dihydroxybenzoic acid, and gallic acid were investigated. These compounds belong to the group of phenolic compounds known for their strong antioxidant activity and are increasingly being studied due to their positive effects on human health. The analysis was conducted using the electrochemical method of differential pulse voltammetry, with the aim of detecting the oxidation of the mentioned antioxidants and examining the influence of their concentration on the height of the oxidation peak current. Experiments were carried out using a three-electrode system consisting of a glassy carbon working electrode, an Ag/AgCl reference electrode, and a platinum counter electrode. Prior to each measurement, the electrochemical cell was purged with high-purity argon (99.999%) to remove dissolved oxygen. The results showed that all analyzed compounds undergo oxidation under certain optimal conditions and that there is a linear relationship between their concentration and the height of the oxidation peak current. The standard addition method was used to confirm the presence of antioxidants in model solutions. Real samples - rosehip tea and green tea - were also analyzed, in which the presence of gallic acid was confirmed. The measured concentrations of gallic acid in real samples were 2.72×10⁻⁵mol dm⁻³ in rosehip tea and 6.09×10⁻⁵ mol dm⁻³ in green tea, confirming the applicability of the method used in the analysis of complex samples
Mechanisms of opiates effects on pregnancy and fetal development
No full textOvaj rad istražuje mehanizam djelovanja opijata na trudnoću i razvoj ploda, s posebnim
naglaskom na razvojne posljedice za fetus. Opijati lako prolaze kroz posteljicu i usporavaju rast i razvoj fetusa te povećavaju i rizik prijevremenog poroda, niske porođajne mase i neonatalnog apstinencijskog sindroma. Mehanizam njihova djelovanja povezan je s promjenama u funkciji opioidnih receptora, poremećajem razvoja mozga te smanjenom opskrbom kisikom i hranjivim tvarima. Posljedice se ne zaustavljaju na rođenju – djeca izložena opijatima nose rizik trajnih neurokognitivnih i emocionalnih poteškoća.This paper explores the mechanism of action of opioids on pregnancy and fetal development, with particular emphasis on developmental consequences for the fetus. Opioids easily cross the placenta, slowing fetal growth and development while increasing the risk of preterm birth, low birth weight, and
neonatal abstinence syndrome. Their mechanism of action is linked to alterations in opioid receptor function, impaired brain development, and reduced supply of oxygen and nutrients. The consequences do not end at birth – children exposed to opioids carry the risk of lasting neurocognitive and emotional difficulties
Coordination complexes of transition metals with hydroxypyranones
No full textKoordinacijski spojevi prijelaznih metala s hidroksipiranonskim ligandima predstavljaju ključnu temu istraživanja u anorganskoj i bioanorganskoj kemiji, zbog sposobnosti navedenih liganada da stvaraju stabilne komplekse s metalnim ionima. Ovaj rad istražuje sintezu i karakterizaciju kompleksa bakra(II) i vanadija(IV) s odabranim hidroksipiranonskim ligandima – maltolom i kojinskom kiselinom. Cilj istraživanja bio je proučiti koordinacijske sposobnosti ovih liganada, analizirati strukturne značajke te termodinamičku stabilnost dobivenih kompleksa. Za postizanje ovog cilja primijenjene su različite analitičke metode, uključujući FT-IR spektroskopiju, termalnu analizu (TGA/DSC) i rendgensku difrakciju na polikristalnom uzorku (PXRD), kako bi se dobio uvid u interakcije između metalnih iona i liganada. Rezultati FT-IR spektroskopije pokazali su pomak vibracija karakterističnih funkcijskih skupina, što ukazuje na interakciju između metalnih iona i liganada. Termalna analiza otkrila je razlike u termičkoj stabilnosti kompleksa, pri čemu je vanadijev(IV) kompleks pokazao veću stabilnost pri višim temperaturama u odnosu na bakrov(II) kompleks. Rezultati PXRD analize ukazali su na jedinstvene
kristalne strukture za oba kompleksa, čime su potvrđene specifične interakcije između metala i liganda. Ovi rezultati pridonose boljem razumijevanju stabilnosti i koordinacijskih svojstava metalnih kompleksa s hidroksipiranonskim ligandima. Daljnja istraživanja mogu omogućiti procjenu bioloških svojstava ovih spojeva te
njihov potencijal u biomedicinskim terapijama, kao i industrijskim primjenama, što otvara prostor za razvoj novih funkcionalnih materijala.Coordination compounds of transition metals with hydroxy-pyranone ligands represent an important and active research area in inorganic and bioinorganic chemistry, due to their ability to form stable complexes with metal ions. This study investigates the synthesis and characterization of copper(II) and vanadium(IV) complexes with selected hydroxy-pyranone ligands—maltol and kojic acid. The aim of the research was to explore the
coordination properties of these ligands, analyze the structural features, and assess the thermodynamic stability of the resulting complexes. To achieve this, various analytical methods were employed, including FT-IR
spectroscopy, thermal analysis (TGA/DSC), and powder X-ray diffraction (PXRD), to gain insight into the interactions between the metal ions and ligands. FT-IR spectroscopy results showed shifts in the vibrations of
characteristic functional groups, indicating interaction between the metal ions and ligands. Thermal analysis revealed differences in the thermal stability of the complexes, with the vanadium(IV) complex showing greater
stability at higher temperatures compared to the copper(II) complex. PXRD analysis results indicated unique crystalline structures for both complexes, confirming specific interactions between the metal and ligand. These
findings contribute to a better understanding of the stability and coordination properties of metal complexes with hydroxy-pyranone ligands. Further research may enable the evaluation of the biological properties of these compounds, as well as their potential in biomedical therapies and industrial applications, thus opening up opportunities for the development of new functional materials
Comparison of the toxicity of cigarettes and e-cigarettes
No full textOvaj rad uspoređuje toksičnost tradicionalnih cigareta i elektroničkih cigareta, usredotočujući se na njihov kemijski sastav i moguće učinke na zdravlje. Cigarete su dobro poznate po tome što sadrže tisuće štetnih tvari, od kojih su mnoge povezane s ozbiljnim bolestima poput raka, bolesti srca i pluća. E-cigarete, koje se često reklamiraju kao sigurnija opcija, obično sadrže manje toksičnih spojeva, ali nisu bez rizika. Njihovi aerosoli još uvijek sadrže nikotin, metale i druge kemikalije koje mogu biti štetne za tijelo. Dok ecigarete mogu smanjiti izloženost nekim od najopasnijih spojeva koji se nalaze u duhanskom dimu, njihov dugoročni učinak na zdravlje još uvijek nije jasan. S obzirom na sve veću popularnost konzumiranja ecigareta, osobito među mladima, potrebno je više istraživanja kako bi se u potpunosti razumjeli rizici.
Općenito, ovaj rad naglašava da iako su e-cigarete možda manje štetne od tradicionalnih cigareta, daleko su od sigurnih.This paper compares the toxicity of traditional cigarettes and electronic cigarettes, focusing on their chemical composition and potential health effects. Cigarettes are well known for containing thousands of harmful substances, many of which are linked to serious diseases such as cancer, heart disease and lung disease. E-cigarettes, often touted as a safer option, typically contain fewer toxic compounds, but they are not without risk. Their aerosols still contain nicotine, metals and other chemicals that can be harmful to the body. While e-cigarettes can reduce exposure to some of the most dangerous compounds found in tobacco smoke, their long-term health effects are still unclear. Given the growing popularity of e-cigarette use, especially among young people, more research is needed to fully understand the risks. Overall, this paper highlights that while e-cigarettes may be less harmful than traditional cigarettes, they are far from safe
Assessment of manganese in biological samples of the inhabitants of Eastern Croatia
No full textEsencijalni element u tragovima, mangan, ključan je za brojne biološke procese, uključuju i metabolizam, antioksidativnu obranu te funkciju vitalnih sustava. Iako je neophodan za zdravlje, pretjerana izloženost manganu povezuje se s pojavom neurodegenerativnih poremećaja poput manganizma te Parkinsonove i Alzheimerove bolesti. Referentne vrijednosti koncentracije mangana korisne su istraživa ima jer odstupanja ispod ili iznad navedenih granica mogu ukazivati na nedostatak ili prekomjerni unos ovog elementa. Zbog nedostatka podataka o razinama mangana u organizmu stanovnika Republike Hrvatske, otežana je procjena zdravstvenih rizika. U tu svrhu, analizirali smo koncentracije mangana u biološkim uzorcima (serum, kosa, urin) 50 ispitanika iz osam naselja isto ne Hrvatske (Vladislavci, Dalj, Čepin, Našice, Osijek, Vukovar, Slavonski Brod i Vinkovci). Mjerenja su provedena metodom masene spektrometrije s induktivno spregnutom plazmom (ICP-MS). Usporedbom referentnih vrijednosti s rezultatima biomonitoringa (serum: 0,28-4,13 g/L; kosa: 0,05-4,87 g/g; urin: 0,08-3,63 g/L) nisu utvrđena značajna odstupanja u koncentracijama mangana među stanovnicima analiziranih područja.Manganese is an essential trace element crucial for numerous biological processes, including metabolism, antioxidant defense, and the function of vital systems. Although necessary for health, excessive exposure to manganese has been associated with neurodegenerative disorders such as manganism, Parkinson's disease, and Alzheimer's disease. Reference values for manganese concentrations are useful for researchers, as deviations below or above the specified limits may indicate a deficiency or excessive intake. Due to a lack of data on manganese levels in the population of the Republic of Croatia, assessing health risks is challenging. To address this, we analyzed manganese concentrations in biological samples (serum, hair, and urine) from 505 subjects across eight settlements in eastern Croatia (Vladislavci, Dalj, Čepin, Našice, Osijek, Vukovar, Slavonski Brod, and Vinkovci). Measurements were performed using inductively coupled plasma mass spectrometry (ICP-MS). When comparing reference values with biomonitoring results (serum: 0.28-4,13 μg/L; hair: 0.05-4.87 μg/g; urine: 0.08-3.63 μg/L), no significant deviations in manganese concentrations were observed among residents of the analyzed areas
Methods for optical detection of perfluoroalkyl compounds
No full textPerfluoroalkilne i polifluoroalkilne tvari, PFAS, predstavljaju skupinu toksičnih i vrlo opasnih spojeva koje se dugoročno zadržavaju u okolišu i ljudskom organizmu. Vrlo su otporne i stabilne čak i pri ekstremnim uvjetima te ih je zbog toga teško detektirati i ukloniti. Nakon dugotrajnih istraživanja i mnogo uloženog truda razvijene su metode koje pomažu u prepoznavanju PFAS spojeva u vodi, tlu, krvi i hrani. Ovaj rad obuhvaća detaljan prikaz djelovanja tih metoda, a kao najpouzdanija i kao metoda koja donosi najbolje rezultate bez da zahtjeva kompleksnu pripremu prije same detekcije, smatra se LC-MS/MS analiza. U ovom radu opisane se mnoge druge metode kao što su elektrokemijske, optičke, fluorescencijske i kolorimetrijske. Glavni cilj ovog rada je predstaviti opasnost koju uzrokuju PFAS spojevi te opisati najpouzdanije metode kojima se navedeni spojevi detektiraju u prirodi.Perfluoroalkyl and polyfluoroalkyl substances (PFAS) represent a group of toxic and highly hazardous compounds that persist in the environment and the human body over long periods. They are extremely resistant and stable, even under extreme conditions, which makes them difficult to detect and remove. After extensive research and significant effort, methods have been developed to help identify PFAS compounds in water, soil, blood, and food. This paper provides a detailed overview of how these methods work, with LC-MS/MS analysis being considered the most reliable and effective technique, as it delivers the best results without requiring complex sample preparation prior to detection. The paper also describes various other methods such as electrochemical, optical, fluorescence, and colorimetric techniques. The main objective of this work is to present the dangers posed by PFAS compounds and to describe the most reliable methods used to detect these substances in the environment