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Preparation of quaternary salts of nicotinamide with supstituted phenacyl bromides in eutectic solvents
No full textU ovom su radu izvedene reakcije kvaternizacije nikotinamida sa supstituiranim fenacil-bromidima u eutektičkim otapalima. Od supstituenata fenacil-bromida korišteni su: 2-brom-4'-metoksiacetofenon, 2-brom-4'-fenilacetofenon, 2,4'-dibromacetofenon. Reakcije kvaternizacije provodile su se u eutektičkim otapalima na bazi kolin klorida (ChCl), te na tri različita načina: klasičnom sintezom, sintezom potpomognutom mikrovalnim zračenjem i sintezom potpomognutom ultrazvučnim valovima. Ovim radom ispitano je mogu li eutektička otapala zamijeniti klasična organska otapala, kao i koja od metoda sinteze daje najveći prinos reakcije.In this thesis, the quaternization reactions of nicotinamide with substituted phenacyl bromides in eutectic solvents were performed. Substituted phenacyl-bromides used in this paper are: 2-bromo-4'-methoxyacetophenone, 2-bromo-4'-phenylacetophenone, 2,4'- dibromacetophenone. Quaternization reactions were performed in choline chloride (ChCl) based eutectic solvents and were performed in three different ways: classical synthesis, microwave assisted synthesis, and ultrasonic wave assisted synthesis. This paper examined the possibility for eutectic solvents to replace conventional organic solvents, as well as which synthesis method gives highest yield of the reaction
Antioxidant properties of carnosine
No full textKarnozin je dipeptidni protein građen od β-alanina i L-histidina. U tijelu se nalazi u skeletnim mišićima, mozgu, jetri, bubrezima i srcu. Karnozin posjeduje antioksidativna svojstva. U ovom radu pobliže su opisani slobodni radikali, pojam oksidativnog stresa te mehanizami lipidne peroksidacije i oštećenja DNA molekula. Govori se o karnozinu, njegovom nastajanju i njegovim metaboličkim putovima. Detaljno su objašnjeni i potkrijepljeni primjerima istraživanja načini antioksidativnog djelovanja karnozina kao i njegova uloga u liječenju bolesti i "anti-age" efektu. Rad je podijeljen u sedam poglavlja, od kojih su prva tri posvećena oksidativnom stresu u općenitom smislu, a četvrto i peto fokusiraju se detaljno na karnozin i njegova antioksidativna djelovanja.Carnosine is a dipeptide protein constructed of β-alanine and L-histidine. In the body it is found in the skeletal muscles, the brain, the liver, the kidneys and the heart. Carnosine has antioxidant properties. This paper closely describes free radicals, the notion of oxidative stress and mechanisms of lipid peroxidation and DNA molecule damage. The paper talks about carnosine, the way it is synthetized and what its metabolic pathways are. Detailed explanations show the antioxidant properties of carnosine as well as its roles in disease treatments and "anti-aging", all of which are supported with examples of actual research. The paper is divided into seven chapters, the first three of which are dedicated to oxidative stress in general terms, and the fourth and the fifth one focus on carnosine and its antioxidant effects
Investigation of the influence of titrant concentration on potentiometric determination of anionic surfactants using sensor with functionalized carbon nanotubes
No full textPovršinski aktivne tvari ili tenzidi bifunkcionalni su organski spojevi s hidrofilnim i hidrofobnim djelom koji imaju tendenciju nakupljanja između dvije faze. Dijele se na anionske, kationske, amfolitske i neionske. Anionski tenzidi u vodi disociraju dajući negativno nabijene organske ione koji su površinski aktivni. Mogu se odrediti korištenjem kromatografskih, titracijskih, spektrofotometrijskih i drugih metoda. Prilikom određivanja anionskih tenzida titracijskim metodama, uglavnom se koriste ionsko-selektivne elektrode (ISE) koje služe kao potenciometrijski senzori. Tijekom potenciometrijskog određivanja anionskih tenzida korišten je senzor temeljen na funkionaliziranim ugljikovim nanocjevčicama i tetrafenilboratu (MWCNT-TPB). Određivan je utjecaj koncentracije titranta na oblik titracijskih krivulja kako bi se odredila najniža koncentracija titranta koja daje analitički uporabljivu završnu točku titracije. Kao titrant korišten je cetilpiridinijev klorid (CPC) koncentracija: 4 x mol/, 4 x mol/, 1 x mol/ i 4 x mol/, a kao analit natrijev dodecilsulfat (NaDDS) istih koncentracija.Surfactants or surface-active agents are bifunctional organic compounds composed of hydrophilic and hydrophobic groups which have tendency of accumulating between two phases. Surfactants are classified into four types: anionic, cationic, amphoteric and nonionic. Anionic surfactants ionize in water solution into the negatively charged surface active organic ions. Anionic surfactants can be determined using titration methods of analysis, chromatographic methods, spectrometric methods, etc. Nowadays, when determining anionic surfactants through the titration methods of analysis, ion-selective electrodes (ISE) are the most frequently used as potentiometric sensors. For potentiometric determination of anionic surfactants, the sensor based on functionalized multi-walled carbon nanotubes and tetraphenylborate (MWCNT-TPB) was used. The effect of titrant concentration on the shape of titration curves was investigated in order to determine the lowest titrant concertation that enables reliable end-point location. Cetylpyridinium chloride (CPC) at concentrations: 4 x mol/, 4 x mol/, 1 x mol/ and 4 x mol/ was used as titrant and the same concentrations of sodium dodecyl sulfate (NaDDS) were used as the analytes
Iron Triad
No full textOvaj završni rad obuhvaća tematiku vezanu za osobine elementa Trijade željeza (željezo, kobalt i nikal). Pobliže su objašnjena zasebna svojstva elemenata te skupine i njihova sposobnost stvaranja jakog magnetskog polja što se naziva feromagnetizam. Zbog svojih feromagnetskih svojstva ovi metali imaju široku primjenu u industriji. Najčešće se koriste u legurama s ugljikom i međusobnim legurama kako bi se dobio zadovoljavajući karakter metala. Također ovi elementi pronalaze svoju primjenu i u bojenju materijala (stakla, tinte), baterijama, zaštitama od korozije, elektronikama i u različitim drugim svrhama koje su od velike važnosti za opći napredak. Stoga cilj ovog rada bio je opisati svojstva elemenata Trijade željeza, njihovu specifičnost i objasniti važnost njihove upotrebe.This final thesis includes theme related to element properties to the Triad of iron (iron, cobalt and nickel). Closely explained separately properties for elements of that group and their ability of creating a strong magnetic field what called ferromagnetism. Cause of it's ferromagnetism performance this materials have a wide application in the industry. Usually they are used in alloys with carbon and mutal alloys in order to obtain satisfactory character of metal. Also this elemente find their use in metal dyeing (glass, ink), batteries, corrosion, protection, electronics and in various of their things which are of a great importance for general progression. Hence the aim of this paper was to bring closer performance elements Triad of iron, their specify and explain importance of their use
Comparison of methods for determining the expression of photosynthetic proteins
No full textFotosinteza je biološki važan proces koji se odvija u kloroplastima. Naizgled jednostavan proces u kojem dolazi do stvaranja ugljikohidrata i kisika iz vode i ugljikova dioksida, zapravo je niz oksidacijsko-redukcijskih reakcija potpomognutih svjetlošću za čije su uspješno odvijanje zaslužni brojni proteinski kompleksi. Jedan od najvažnijih proteinskih kompleksa je fotosustav II (PSII), koji je i mjesto inicijacije fotosintetskih reakcija na svjetlu. Njegove najvažnije komponente su antena kompleks i reakcijsko središte (građeno od D1 i D2 proteina) te kompleks za razvijanje kisika (OEC) na čijoj vanjskoj strani se nalaze tri male proteinske podjedinice: PsbO, PsbP i PsbQ. U reakcijama neovisnim o svjetlosti (Calvinov ciklus) nastaju organske molekule iz , a prvi korak (fiksaciju ) katalizira enzim Rubisco. Cilj našeg istraživanja bio je usporediti metode za određivanje ekspresije fotosintetskih proteina: D1, PsbO podjedinice OEC-a i velike podjedinice Rubisca. Proteini su izdvojeni iz biljnog materijala pomoću dvije različite metode: metodom izolacije ukupnih proteina i metodom izolacije proteina iz kloroplasta. Odvojeni su prema molekulskoj masi (SDS-PAGE) i detektirani imunodetekcijom (Western blot). Proteinske vrpce dobivene su na filmu pomoću metode kemiluminiscencije. Usporedbom proteinskih vrpci dviju metoda, određena je pogodnija metoda za određivanje ekspresije pojedinih fotosintetskih proteina.Photosynthesis is a biologically important process in plants that takes place in chloroplasts. Even though it seems like a simple process which produces carbohydrates and oxygen from water and carbon dioxide, it is actually a series of light-driven oxidation-reduction reactions in which a large number of protein complexes take part. One of the most important protein complexes is photosystem II (PSII), where initiation of light-dependent photosynthetic reactions happens. The most important components of PSII are: antenna complex, the reaction center (made of D1 and D2 proteins) and oxygen evolving complex (OEC) which contains three small extrinsic protein subunits: PsbO, PsbP and PsbQ. In dark reactions (the Calvin cycle), organic molecules are formed from and the first step ( fixation) is catalyzed by enzyme Rubisco. The aim of this work was to compare methods for determining the expression of photosynthetic proteins: D1, PsbO subunit of OEC and the large subunit of Rubisco. Proteins were isolated from the plant tissue using two methods: isolation of the total soluble proteins and isolation of proteins from chloroplasts. Isolated proteins were separated by molecular mass using electrophoresis (SDS-PAGE) and detected by Western blot method. Protein bands were detected on film using chemiluminescence. Comparison of protein bands obtained by two methods, the more suitable method for detection of photosynthetic proteins expression of was determined
Molecular motion in gases
No full textKinetička teorija plinova znanstveni je model koji objašnjava fizikalna svojstva plinova kao posljedicu gibanja molekularnih čestica koje čine plin. Na kinetičkoj teoriji plinova zasniva se i Maxwell-Boltzmannova raspodjela brzina koja je ključna u definiranju pojmova kao što su najvjerojatnija brzina, prosječna brzinu te korijen srednjeg kvadrata brzine. Pomoću kinetičke teorije možemo objasniti i sudare molekula, te definirati pojmove: sudarni presjek, učestalost sudara i kolizijski tok. Efuzija je pojava širenja plina iz posude u okolinu kroz otvor čiji je promjer relativno velik u odnosu na promjer molekule i kvantitativno je opisana Grahamovim zakonom.The kinetic theory of gases is a scientific model that explains the physical behavior of a gas as the motion of the molecular particles that compose the gas. Maxwell-Boltzmann speed distribution is also based on kinetic gas theory, which is crucial in defining terms such as the most probable speed, average speed and root-mean-square of the velocity. The kinetic theory of gases also explains the collisions of gas molecules, defining the terms: the collisional cross section, the collision frequency, the mean free path and the collision flux. Effusion is the process in which a gas escapes from a container through an opening considerably bigger than the diameter of the molecule and was quantitatively described by Graham's law
Polyphenolic profile and bioactivity of compounds present in Black Elderberry, Sambucus nigra L.
No full textAntioksidansi su spojevi koji svojim djelovanjem povoljno utječu na obranu organizma od bolesti. Iz tog razloga konzumacija antioksidansa dovodi do poboljšanja općeg stanja organizma. Crna bazga (Sambucus nigra L.) je biljka bogata antioksidansima koji primarno štite biljku od destruktivnog djelovanja mikroorganizama, ali i od ostalih štetnih djelovanja. Crna bazga je u svijetu široko rasprostranjena biljka. Za njezina antioksidacijska svojstva odgovorna je prisutnost polifenolnih spojeva, točnije flavonoida. Flavonoidi su heterociklički spojevi s više aromatskih jezgara, organizirani su u sedam podskupina, od kojih se uz crnu bazgu vežu antocijanini i flavonoli. Cilj ovog završnog rada je analizirati polifenolni sastav crne bazge, te proučiti njihovu biološku aktivnost. Ovakvom analizom dobiti će se stvarna slika crne bazge kao ljekovite biljke.Antioxidants are compounds that have a beneficial effect on the body's defence against diseases. Therefore, in order to improve general health, it is necessary to implement food rich with antioxidants in everyday diet. Black elderberry (Sambucus nigra L.) is a plant rich in antioxidants whose primary role is to protect the plant from destructive effects of microorganisms, and also against other harmful effects. Black elderberry is generally a largely widespread plant. The presence of polyphenolic compounds, specifically flavonoids, is the main contributing factor for its antioxidant properties. Flavonoids are heterocyclic compounds with multiple aromatic nuclei and are organized into seven subgroups, of which anthocyanins and flavonols can be found in black elderberry. The aim of this bachelor's thesis is to analyse the polyphenolic profile of black elderberry, and the biological activity of present compounds. Through such analysis we can obtain an actual image of black elderberry as a medicinal plant
Selection of the titrant for potentiometric determination of anionic surfactants using sensor with functionalized carbon nanotubes
No full textTenzidi su bifunkcionalni organski spojevi koji smanjuju površinsku napetost tekućina. Sastoje se od hidrofilnog i hidrofobnog dijela. U vodenim otopinama disociraju kationski, anionski i amfolitski tenzidi, dok neionski tenzidi ne disociraju. Anionski tenzidi su glavni sastojak deterdženata te se u kućanstvima najčešće koriste, no bitna je njihova kontrola jer mogu djelovati štetno na okoliš i otpadne vode. Metoda kojom se tenzidi vrlo često određuju naziva se potenciometrijska titracija. Sustav za potenciometrijsku titraciju se sastoji od potenciometra, referentne i indikatorske elektrode. Preko potencijala indikatorske elektrode može se odrediti koncentracija iona u otopini u koju je elektroda uronjena. U ovom radu je kao indikatorska elektroda korištena ionsko-selektivna elektroda s čvrstim kontaktom u kojoj je kao senzorski materijal korišten ionski par izgrađen od funkcionaliziranih višestjenčanih ugljikovih nanocjevčica i tetrafenilborata (MWCNT-TPB). Pri potenciometrijskoj titraciji natrijeva dodecil sulfata koncentracije 4 x 10-3 mol/dm3 su kao titranti korišteni cetilpiridinijev klorid (CPC), 1,3-didecil-2-metilimidazolijev klorid (DMIC), diizobutil-fenoksietoksi-etil-dimetil-benzil-amonijev klorid (Hyamine) i heksadecil-trimetil-amonijev bromid (CTAB) koncentracije 4 x 10-3 mol/dm3. Najbolji rezultati su uočeni korištenjem CPC-a i DMIC-a, dok su CTAB i Hyamine pokazali nešto lošije rezultate. Iako je DMIC imao najveći skok potencijala u točki ekvivalencije, kao titrant je izabran CPC s obzirom na točnije rezultate.Surfactants are bifunctional organic compounds that lower the surface tension between liquids. They contain hydrophilic and hydrophobic groups. Cationic, anionic and amphoteric surfactants dissociate in aqueous solutions, while nonionic surfactants don't dissociate. Anionic surfactants are the main ingredients in detergents and they are mostly used in households, but it's necessary to control them because they can be dangerous to the environment and the wastewaters. They are most often determinated by potentiometric titration. The system for potentiometric titration is composed of potentiometer, reference and indicator electrode. Concentrations of ions are determinated by using the potential of indicator electrode in the solution that the electrode is put in. In this paper, the solid-state ion-selective electrode was used as the indicator electrode. Ionic pair used as a sensor material was functionalized multiwalled carbon nanotubes and tetraphenilborate (MWCNT-TPB). In potentiometric titration of sodium dodecyl sulfate concentration of 4 x mol/, cetylpyridinium chloride (CPC), 1,3-didecyl-2-methylimidazolium chloride (DMIC), diisobutyl-phenoxyethoxy-ethyl-dimethylbenzyl ammonium chloride (Hyamine) and hexadecyltrimethylammonium bromide (CTAB) were used as titrants. All concentrations were 4 x mol/. CPC and DMIC showed the best performances. Although DMIC had a slightly higher potential jump in equivalence point, CPC was selected as a titrant due to more accurate results
Innate system and natural killer cells
No full textImunosni sustav razlikuje vlastito od stranog i odstranjuje potencijalno štetne strane molekule i stanice iz organizma. Imunosni sustav također ima sposobnost prepoznavanja i uništavanja promijenjenih vlastitih stanica koje potječu iz tkiva domaćina. Antigen je svaka molekula koju imunološki sustav prepoznaje. Urođeni (prirodni ili nespecifični) imunitet ne zahtjeva prethodni kontakt s antigenom za aktivaciju. Ukoliko virus ili bakterija prođu kožu ili sluznicu na našem tijelu i napadnu našu stanicu, aktiviraju se signali koje odmah registiraju prirodne stanice ubojice (NK stanice). One imaju sposobnost uništiti inficiranu stanicu u nekoliko sati dok zdravu poštede. Prirodne stanice ubojice pomažu i u obrani od tumora na način da, identificiraju i razlikuju tumorske stanice od normalnih. Sve zdrave stanice u tijelu sadrže MHC I receptore, a ukoliko je stanica zaražena ona neće posjedovati ove receptore. Ako NK stanice nemogu pronaći MHC I receptore na nekoj stanici odmah ju uništavaju.The immune system differentiates its own from the foreign and removes potentially harmful alien molecules and cells from the organism. The immune system also has the ability to recognize and destroy its own cells, those from the host tissue, but have been some ways transformed. An antigen is any molecule that is recognized by the immune system. Innate (natural or non-specific) immunity does not require prior contact with activating antigen. If a virus or bacterium passes the skin or mucous membrane in our body, and attacks our cells, the signals immediately register the natural cells of the killer. If the virus or bacteria pass through the skin or mucous membrane in our body and attack our cells, the signals that are activated are immediately registered by the natural killer cells (NK cells). They have the ability to destroy the infected cell in a matter of hours while not affecting the healthy cells. Natural killer cells also help in protecting against tumors by identifying and distinguishing tumor cells from normal. All healthy cells in the body contain MHC I receptors, and if the cell is infected it will not possess these receptors. If the NK cells can not find the MHC I receptors on a cell, they will immediately destroy them
Voltametric detection of arsenic in artesian water samples
No full textU ovom radu ispitivana su elektrokemijska svojstva arsenitnih () iona u standardnim otopinama arsenitnih iona te u uzorcima bunarske vode iz arteških bunara u fosfatnom puferu pH = 7. Cilj rada bila je elektrokemijska detekcija arsena u modelnim sustavima te uzorcima bunarske vode pomoću nemodificirane i modificirane elektrode od staklastog ugljika. Razlike između površine nemodificirane i modificirane elektrode od staklastog ugljika utvrđene su elektrokemijskom impedancijskom spektroskopijom. Za detekciju arsena korištene su dvije voltametrijske metode, ciklička i diferencijalna pulsna voltametrija. Za voltametrijska mjerenja koristio se troelektrodni sustav s radnom elektrodom od staklastog ugljika, referentnom Ag/AgCl elektrodom te protuelektrodom platinskom žicom. Mjerenja su provedena u otopini fosfatnog pufera (pH = 7), uz dodatak iona (c () = 1 · mol ) te u uzorcima bunarske vode s modificiranom elektrodom od staklastog ugljika. U svim uzorcima bunarske vode uzorkovanim tijekom 9. i 10. mjeseca utvrđena je prisutnost arsena što je dodatno potvrđeno porastom strujnih vrhova dodatkom iona u ispitivani uzorak. Nakon modifikacije elektrode od staklastog ugljika, arsen se mogao kvalitativno detektirati i cikličkom i diferencijalnom pulsnom voltametrijom prilikom čega se prednost daje diferencijalnoj pulsnoj voltametriji zbog izraženijih oksidacijskih strujnih vrhova.In this study, we have investigated the electrochemical properties of arsenic () ions in standard solutions of arsenic ions and in samples of well water from the artesian wells in phosphate buffer pH = 7. The goal of the study was the electrochemical detection of arsenic in the model systems, and well water samples using unmodified and modified glassy carbon electrodes. Differences between the surface of unmodified and modified glassy carbon electrodes were determined by electrochemical impedance spectroscopy. For the detection of arsenic, two voltammetric methods were used, cyclic and differential pulse voltammetry. For voltammetric measurements, a three-electrode system with a working glassy carbon electrode, a reference Ag / AgCl electrode and a platinum counter electrode were used. The measurements were performed in a phosphate buffer solution (pH = 7), with the addition of ion (c () =1 · mol ) and in samples of well water with a modified glassy carbon electrode. In all samples of well water taken during the September and October, the presence of arsenic was found and additionally confirmed by the increase of oxidation and reduction peaks with the addition of ions in tested samples. After modification of the glassy carbon electrode, arsenic could be qualitatively detected by cyclic and differential pulse voltammetry with the advantage on differential pulse voltammetry because of the more pronounced oxidation peak currents