Fire extinguishing tactic in correctional facilities

Ovaj rad istražuje taktiku gašenja požara u zgradama kaznenih institucija, s naglaskom na specifične izazove i zahtjeve koje takvi objekti postavljaju pred vatrogasne postrojbe. Zgrade kaznenih institucija imaju jedinstvenu arhitekturu i sigurnosne mjere koje dodatno kompliciraju vatrogasne intervencije. Analizirane su karakteristike požara u zatvorenim prostorima, uključujući načine na koje se požar može širiti i specifične rizike povezane s ovim tipom objekata. Razmatrane su različite strategije gašenja požara, od tradicionalnih metoda do upotrebe naprednih tehnologija poput termovizijskih kamera i automatskih sustava za gašenje. Rad također naglašava važnost sigurnosnih protokola, uključujući pravilnu procjenu rizika prije ulaska u zatvoreni prostor. Identifikacija opasnosti i implementacija mjera predostrožnosti ključni su za smanjenje rizika za vatrogasce i zatvorenike. Procjena rizika obuhvaća analizu strukturalne stabilnosti zgrade, identifikaciju potencijalno opasnih materijala i procjenu uvjeta unutar prostora zahvaćenog požarom. Posebna pažnja posvećena je komunikaciji i koordinaciji među vatrogasnim timovima i drugim službama. Učinkovita komunikacija i koordinacija ključni su za brzo donošenje odluka i uspješno upravljanje intervencijom. Korištenje naprednih komunikacijskih sustava omogućuje neprekidnu razmjenu informacija, što je od vitalne važnosti u dinamičnim i opasnim situacijama. Evidentno da uspjeh intervencija u zgradama kaznenih institucija ovisi o detaljnoj procjeni rizika, učinkovitoj upotrebi naprednih tehnologija i jasnoj komunikaciji. Potrebna je kontinuirana obuka vatrogasaca kako bi se osigurala njihova spremnost za specifične uvjete ovih intervencija. Rad također naglašava potrebu za daljnjim istraživanjima i razvojem novih strategija koje će dodatno poboljšati taktiku gašenja požara, s ciljem osiguravanja sigurnosti zatvorenika, osoblja i vatrogasaca.This paper investigates firefighting tactics in prison buildings, focusing on the specific challenges and demands these structures impose on fire brigades. Prison buildings have unique architecture and security measures that further complicate firefighting operations. The study analyses the characteristics of fires in confined spaces, including how fires spread and the specific risks associated with these types of buildings. Various firefighting strategies are considered, from traditional methods to advanced technologies like thermal imaging cameras and automatic suppression systems. The paper also highlights the importance of safety protocols, including proper risk assessment before entering confined spaces. Identifying hazards and implementing precautionary measures are crucial for reducing risks to firefighters and inmates. Risk assessment involves analysing the structural stability of the building, identifying potentially hazardous materials, and assessing conditions within the fire-affected area. Special attention is given to communication and coordination among fire teams and other services. Effective communication and coordination are crucial for quick decision-making and successful management of interventions. The use of advanced communication systems ensures continuous information exchange, which is vital in dynamic and hazardous situations. It is evident that the success of interventions in prison buildings depends on detailed risk assessment, effective use of advanced technologies, and clear communication. Continuous training of firefighters is necessary to ensure their readiness for the specific conditions of these interventions. The paper also emphasizes the need for further research and development of new strategies to improve firefighting tactics, with the aim of ensuring the safety of inmates, staff, and firefighters

Physiotherapy interventions in radial nerve damage

Nervus radialis je mješoviti živac koji nastaje iz stražnjeg snopa ručnog spleta. Osjetno inervira kožu stražnje strane nadlaktice i podlaktice, hrbat šake i djelomično kožu prstiju. Glavne motoričke funkcije su ekstenzija podlaktice, ručnog zgloba i prstiju, ekstenzija i abdukcija palca, supinacija podlaktice, te pregibanje podlaktice u položaju između supinacije i pronacije. Kao posljedica oštećenja živca ovisno o mjestu ozljede mogu nastati kljenuti svih mišića koje inervira ili su pošteđene grane za pojedine mišiće. Najčešće se manifestira visećom šakom. Oštećenje je najčešće u razini spiralnog žlijeba humerusa, a rjeđe u razini m.supinatora. Liječenje ovisi o uzroku, lokalizaciji i stupnju oštećenja, a može biti konzervativno ili kirurško. Uz prikladnu i preciznu dijagnostiku potreban je stručan plan i program rehabilitacije pacijenta koji mora biti individualno prilagođen. Fizioterapijske intervencije kao dio rehabilitacije uključuju kineziterapiju, termoterapiju, elektroterapiju, biofeedback, magnetoterapiju, hidroterapiju, laser, radnu terapiju, masažu, akupunkturu, primjenu ortoza. Fizioterapijskim intervencijama poboljšava se opseg pokreta zglobova, snaga i fleksibilnost mišića, smanjuje bol, preveniraju se ili korigiraju kontrakture te ubrzava oporavak živca. Učinkovitost fizioterapijskih procedura je dokazana u brojnim istraživanjima, ali su potrebna i daljnja istraživanja koja bi uspoređivala različite fizioterapijske intervencije.Nervus radialis is a mixed nerve that arises from the posterior bundle of the manual plexus. It sensibly innervates the skin of the back of the upper arm and forearm, the back of the hand and partially the skin of the fingers. The main motor functions are extension of the forearm, wrist and fingers, extension and abduction of the thumb, supination of the forearm, and flexion of the forearm in a position between supination and pronation. As a result of nerve damage, depending on the location of the injury, numbness of all the muscles it innervates may occur, or branches for individual muscles may be spared. Most often is manifested by a hanging fist. The damage is most often at the level of the spiral groove of the humerus, and less often at the level of the supinator m. Treatment depends on the cause, localization and degree of damage, and can be conservative or surgical. In addition to appropriate and precise diagnostics, a professional plan and program of rehabilitation of the patient is needed, which must be individually adapted to the patient. Physiotherapy interventions as part of rehabilitation include kinesitherapy, thermotherapy, electrotherapy, biofeedback, magnetotherapy, hydrotherapy, laser, occupational therapy, massage, acupuncture, application of orthoses. Physiotherapy interventions improve joint range of motion, muscle strength and flexibility, reduce pain, prevent or correct contractures, and accelerate nerve recovery. The effectiveness of physiotherapy procedures has been proven in numerous studies, but further research comparing different physiotherapy interventions is needed

Prirodne tvari u liječenju neuropatske boli

Cilj istraživanja Neuropatska bol zahvaća 7-10 % opće populacije, a standardna farmakoterapija je učinkovita u manje od 50 % pacijenata i uzrokuje mnogo nuspojava koje ograničavaju njihovo korištenje. Cilj ovog specijalističkog rada je pretražiti kliničke znanstvene spoznaje o učinkovitosti i sigurnosti primjene odabranih prirodnih tvari u liječenju neuropatske boli kako bi se istražile nove učinkovite terapijske mogućnosti kod ove vrste boli. Materijali i metode Istraživanja u okviru ovoga specijalističkog rada teorijskog su karaktera i uključuju pregled dostupne literature o dosadašnjim suvremenim znanstvenim spoznajama o odabranim prirodnim tvarima u liječenju neuropatske boli. U pretraživanju radova relevantnih za temu ovoga rada korištene su elektronske bibliografske baze podataka PubMed (Medline), Science Direct, Scopus i Cochrane Library. Važan izvor informacija bile su i monografije i izvješća o ocjeni biljnih droga koje donosi Europska agencija za lijekove. Rezultati Potencijal u liječenju neuropatske boli, temeljem utvrđenih mehanizama djelovanja i pretkliničkih istraživanja, pokazale su sljedeće biljne tvari i vrste: kapsaicin, kanabinoidi, kurkumin, noćurak, šafran i gospina trava. Najviše kliničkih dokaza ima lokalna primjena kapsaicina u obliku flastera (8 %) kod liječenja postherpetične i dijabetičke neuropatije te neuropatije povezane s HIV-om. Kvaliteta dokaza je bila umjerena ili vrlo niska, uglavnom zbog malog broja istraživanja i nedovoljno ispitanika. Iako su provedena brojna istraživanja s pripravcima na bazi kanabinoida, dokazi o njihovoj učinkovitosti su nedostatni. Oromukozni sprej na bazi kanabinoida (2,7 mg THC/2,5 mg CBD) smanjuje bol i olakšava spavanje kod pacijenata s perifernom neuropatskom boli i centralnom neuropatijom kod multiple skleroze. Dvije studije su ukazale na povoljan učinak različitih formulacija kurkumina kod perifernih neuropatija. Također, kliničke studije koje bi potvrdile povoljan učinak noćurka, šafrana i gospine trave u liječenju neuropatske boli nedostaju (jedna do dvije relevantne studije). Zaključak Za navedene biljne tvari i vrste potrebno je provesti velike, dobro dizajnirane i kontrolirane studije kako bi se osigurali čvrsti dokazi o njihovoj mogućoj učinkovitosti i sigurnosti u liječenju neuropatske boli. Poticanje primjene prirodnih tvari u liječenju ove vrste boli može smanjiti upotrebu i nuspojave konvencionalnih lijekova te povećati kvalitetu života pacijenata.Objectives The prevalence of neuropathic pain is estimated between 7 and 10 % in the general population and standard pharmacological treatments are effective in less than 50 % of patients and often are associated with undesirable side-effects that limit their use. The aim of this specialistic work is to research clinical scientific knowledge about efficacy and safety of selected natural products in the treatment of neuropathic pain in order to examine new therapeutic options for this type of pain. Material and Methods Research in this work is of theoretical character and includes an overview of the available literature on the up-to-date scientific knowledge about selected natural products in the treatment of neuropathic pain. Electronic bibliographic databases such as PubMed (Medline), Science Direct, Scopus and Cochrane Library were searched for relevant literature for this work. European Union herbal monographs and assessment reports were also an important source of information. Results Based on established mechanisms of action and preclinical research, these are natural products and plant species that have potential in treating neuropathic pain: capsaicin, cannabinoids, curcumin, evening primrose, saffron and St John's wort. Best evidence has local use of the capsaicin patch (8 %) in the treatment of postherpetic, diabetic neuropathy and neuropathy associated with HIV. Quality of the evidence was moderate or very low, mainly due to the small number of studies and insufficient number of participants. Despite a large number of studies with cannabinoids, evidence of efficacy is still lacking. Oromucosal spray with cannabinoids (2.7 mg THC/2.5 mg CBD) reduces the pain and sleep disorders in patients with peripheral neuropathic pain and central neuropathic pain in multiple sclerosis. Two studies have shown beneficial effects of different formulations of curcumin on peripheral neuropathies. Likewise, clinical studies that prove beneficial effects for evening primrose, saffron and St John's wort in treating neuropathic pain are lacking (one or two relevant studies). Conclusion Large, well-designed and controlled studies are needed for these herbal substances and species to provide strong evidence of their possible efficacy and safety in the treatment of neuropathic pain. Encouraging the use of natural products in the treatment of this type of pain can reduce the use and side effects of conventional drugs and increase the quality of life of patients

Application of the methodology of artificial intelligence and machine vision in the field of metrology

Mnogo je optičkih mjernih uređaja koji se danas koriste u kontroli kvalitete, a svaki od njih koristi barem neki algoritam koji spada u kategoriju strojnog učenja i umjetne inteligencije. Na temelju jednog takvog uređaja analizirat će se njegov rad i algoritmi za prepoznavanje oblika, detekciju rubova i detekciju kontura. Kako bi predmet mjerenja bio što manje ovisan o mjeritelju, napravljen je i nosač koji je postavljen na uređaj i na kojem je, nakon izrade programa, izmjereno sto uzoraka i alat kojim su oni napravljeni. Na temelju izmjera napravljena je analiza o potrošnji alata na navedenim uzorcima. Ovisnost izmjera oduvijek je povezana sa načinom osvjetljenja te su u radu navedena najčešća osvjetljenja i koja se od njih koriste na mikroskopu i optičkom profilometru. Na uređajima je napravljen i test koji pokazuje varijacije u dimenzijama ovisno o osvjetljenju.There are many optical measuring devices used in quality control today, and each of them employs at least some algorithm falling into the category of machine learning and artificial intelligence. Based on one such device, its operation and algorithms for shape recognition, edge detection, and contour detection will be analyzed. To minimize the dependence of the measurement object on the operator, a fixture has been created and placed on the device. After programming, a hundred samples were measured with the tool created. An analysis of tool wear on the specified samples was conducted based on the measurements. The dependency of measurements has always been associated with the lighting conditions, and the most common illuminations used on the microscope and optical profilometer are mentioned in the paper. A test was conducted on the devices to show the variations in dimensions relative to the lighting conditions

Role of clathrin mediated endocytosis in adenovirus type 26 induced inflammasome activation in vitro

Vektorske vakcine na bazi adenovirusa čovjeka tipa 26 (HAdV-D26) intenzivno se istražuju unazad nekoliko godina. Unatoč tome mehanizmi aktivacije urođenog imunosnog sustava ovim virusom još nisu u potpunosti istraženi. Inflamasom je signalni kompleks koji preko kaspaze-1 aktivira proupalne interleukine važne za upalni odgovor i zaštitu od patogena. Cilj ovog rada bio je istražiti kako inhibicija endocitoze posredovane klatrinom utječe na aktivaciju inflamasoma u epitelnim stanicama čovjeka inficiranima virusom HAdV-D26. Metodom reverzne trenskripcije i lančanom reakcijom polimerazom u stvarnom vremenu utvrđeno je smanjenje ekspresije gena za proupalne interleukine IL-1β i IL-18 i kaspazu-1 nakon infekcije, a inhibicijom endocitoze posredovane klatrinom ona se povećala. Aktivacija inflamasoma je bila analizirana i na razini proteina westernskom metodom otiska i metodom imunofluorescencije. Pritom nisu uočene značajne promjene u ekspresiji proteina NLRP3, AIM2 i ASC koji sudjeluju u nastanku inflamasoma, kao ni u njihovoj unutarstaničnoj lokalizaciji, neovisno o inhibiciji endocitoze posredovane klatrinom. Također nisu bili detektirani ni aktivni oblici kaspaze-1 i proupalnih interleukina IL-1β i IL-18. Na temelju toga se može zaključiti da infekcija virusom HAdV-D26 ne aktivira inflamasom u epitelnim stanicama čovjeka. No s druge su strane infekcija virusom HAdV-D26 i inhibicija endocitoze posredovane klatrinom potaknule oslobađanje katepsina B iz lizosoma što može biti signal za sklapanje i aktivaciju inflamasoma.Vector vaccines based on human adenovirus type 26 (HAdV-D26) have been intensively researched for several years. Regardless, the mechanisms of activation of the innate immune system by this virus have not yet been fully investigated. The inflammasome is a signaling complex that via caspase-1 activates pro-inflammatory interleukins important for the inflammatory response and protection against pathogens. The aim of this study was to investigate how inhibition of clathrin-mediated endocytosis affects inflammasome activation in human epithelial cells infected with HAdV-D26. The quantitative polymerase chain reaction revealed a decrease in gene expression for pro-inflammatory interleukins IL-1β i IL-18 and caspase-1 after infection, while inhibition of clathrin-mediated endocytosis increased it. Inflammasome activation was also analyzed at the protein level by western blot and immunofluorescence. No significant changes were observed in the expression of proteins NLRP3, AIM2 and ASC which are involved in the formation of inflammasome, nor in their intracellular localization, regardless of the inhibition of clathrin-mediated endocytosis. Active forms of caspase-1 and pro-inflammatory interleukins IL-1β i IL-18 were also not detected. Based on this, it can be concluded that infection with HAdV-D26 does not activate inflammasome in human epithelial cells. However, infection with HAdV-D26 and inhibition of clathrin-mediated endocytosis stimulated the release of cathepsin B from lysosomes, which could be the signal for inflammasome assembly and activation

Thermodynamic and structural studies on the complexation of methyl esters of tetra and hexaphenylalanine with anions in acetonitrile

Ciklički peptidi predstavljaju posebno zanimljivu klasu supramolekulskih anionskih receptora zbog svoje raznolikosti i vrlo dobrih kompleksacijskih svojstava. Prvi korak sinteze cikličkih peptida je priprava njihovih linearnih analoga, a zatim se provodi reakcija ciklizacije. Najvažnija komponenta uspješne ciklizacije je konformacijska preorganizacija linearnog peptida u kojoj dolazi do približavanja N i C reaktivnih krajeva. Preorganizacija se može pospješiti korištenjem templatnih iona. U ovom radu istraženo je kompleksiranje metilnih estera linearnog tetra i heksafenilalanina s halogenidnim i oksoanionima u acetonitrilu. Konstante stabilnosti nastalih kompleksa određene su metodama 1H NMR spektroskopije, spektrofluorimetrije i spektroskopije cirkularnog dikroizma. Strukturne karakteristike anionskih kompleksa oba receptora istražene su simulacijama molekulske dinamike. Rezultati upućuju na to da su anioni koordinirani pomoću amidnih i amino protona peptida. Većina nastalih kompleksa je stehiometrije 1:1, osim u slučaju dihidrogenfosfata kod kojeg je uočena i stehiometrija 1:2 (receptor:anion)Cyclic peptides represent a particularly interesting class of supramolecular anion receptors due to their diversity and good complexation properties. The first step in the synthesis of cyclic peptides is the preparation of their linear analogues after which the cyclization is carried out. The most important factor for a successful cyclization is the conformational reorganization of the linear peptide, in which the N and C reactive ends approach each other. Reorganization can be enhanced using templating ions. In this work, the complexation of methyl esters of linear tetra and hexaphenylalanine with halide and oxoanions in acetonitrile was investigated. The stability constants of corresponding complexes were determined by 1H NMR spectroscopy, spectrofluorimetry and circular dichroism spectroscopy. The structural characteristics of the anionic complexes of both receptors were investigated by molecular dynamics simulations as well. The results indicate that the anions are coordinated by the amide and amino protons of the peptide. Most of the resulting complexes are of 1:1 stoichiometry, except in the case of dihydrogen phosphate, where a 1:2 stoichiometry (receptor:anion) was also observed

Hazards of radiation in non-destructive testing of metal materials using the radiographic method

Nerazorna metoda radiografije, koja se sve više koristi u industriji za ispitivanje metalnih materijala donosi brojne prednosti, ali istovremeno izlaže osoblje i radnu okolinu opasnosti od zračenja. Upravo zbog toga, sigurnost pri primjeni ove metode je iznimno važna tema. Cilj završnog rada je pružiti dublji uvid u opasnosti i rizike od zračenja pri ispitivanju metalnih materijala nerazornom metodom radiografije, kroz konkretni primjer ispitivanja metalne cijevi u tvrtki STSI d.o.o. Prikazane su i provedene mjere predostrožnosti koje treba poduzeti kako bi se osigurala sigurnost osoblja i radne okoline. Nepravilna primjena ili nedostatak sigurnosnih mjera mogu dovesti do ozbiljnih posljedica, uključujući ozračenje osoblja i štetne utjecaje na okolinu. Stoga, osiguranje sigurnosti tijekom ispitivanja metodom radiografije postaje ključno. Pravilna obuka osoblja o sigurnosnim postupcima i korištenju zaštitne opreme poput dozimetara provedena je u ovom radu pri ispitivanju nerazornom metodom radiografije. Važnost održavanja sigurnosnih standarda u radnom okruženju, uključujući označavanje radioloških područja, ograničavanje pristupa neautoriziranim osobama i pravilno odlaganje radioaktivnog otpada utvrđeno je u radu kroz ispitivanje metalne cijevi nerazornom metodom radiografije. U radu je naglašena važnost sigurnosti pri primjeni metode radiografije u industrijskom ispitivanju metalnih materijala. Uz sigurnost osoblja pri ispitivanju metodom radiografije provedeno je ispitivanje kvalitete zavara na metalnoj cijevi pri čemu je utvrđeno je da ne pokazuje nikakve nedostatke. Također su utvrđene potencijalne opasnosti od zračenja prije, za vrijeme i nakon provođenja radiografskih ispitivanja pri čemu je određena obavezna zaštitna oprema i postupci.The non-destructive method of radiography, which is increasingly being used in the industry for testing metallic materials, brings numerous advantages but at the same time exposes personnel and the working environment to radiation hazards. Due to this, safety in the application of this method is an extremely important topic. The aim of paper is to provide a deeper insight into the dangers and risks of radiation during the testing of metal materials using the non-destructive method of radiography, through a specific example of testing a metal pipe at STSI Ltd. The precautionary measures that need to be taken to ensure the safety of personnel and the working environment are presented and performed. Improper application or lack of safety measures can lead to serious consequences, including personnel irradiation and adverse effects on the environment. Therefore, ensuring safety during radiographic testing becomes crucial. Proper staff training on safety procedures and the use of protective equipment such as dosimeters was carried out in this paper during examination by the non-destructive method of radiography. The importance of maintain safety standards in the work environment, including the marking of radiological areas, restricting access to unauthorized individuals, and proper disposal of radioactive waste is established in the paper through the examination of a metal pipe by the non- destructive method of radiography. In the paper, the importance of safety in the application of radiographic methods in industrial testing of metallic materials is emphasized. In addition to the safety of the personnel during the examination by radiography, a test of the weld quality on the metal pipe was carried out. It was determined that it did not show any defects. Potential hazards from radiation before, during and after radiographic tests were also determined, where protective equipment and procedures are provided

Surfactant-free microemulsion composed of water, ethanol and heptanol and its effect on silicon dioxide synthesis

Mikroemulzije su prozirni, termodinamički stabilni i optički izotropni sustavi koji se sastoje od različitih omjera ulja, vode, surfaktanta i kosurfaktanta. Dugo se smatralo da moraju sadržavati značajnu količinu površinski aktivne tvari. Ipak, dokazano je da se mogu formirati i iz ternarnih smjesa ulja, vode i „amfi-otapala“. Prema faznom dijagramu trokomponentnog sustava voda/etanol/heptanol mikroemulzijskom tehnikom sintetizirao sam nanočestice silicijeva dioksida i njihova svojstva (oblik i veličinu) analizirao pretražnom elektronskom mikroskopijom. Ovim radom želim osvijestiti važnost nanotehnologije u naznovrsnim područjima ljudske djelatnosti i zainteresirati istraživače za daljnji rad na ovom sustavu.Microemulsions are transparent, thermodynamically stable and optically isotropic systems consisting of different ratios of oil, water, surfactant and cosurfactant. For a long time, it was considered that they must contain a significant amount of surfactant. However, it has been proven that they can also be formed from ternary mixtures of oil, water and an "amphi-solvent". According to the phase diagram of the three-component system water/ethanol/heptanol, I synthesized solid silica nanoparticles using the microemulsion technique and analyzed their properties (shape and size) by scanning electron microscopy. With this work, I want to raise awareness of the importance of nanotechnology in various areas of human activity and interest researchers in further work on this system

Preparation of polymer nanocomposites with cellulose and functional amino methacrylates

Kao i brojne druge svjetske industrije, kemijska industrija u novije doba napušta uporabu fosilnih sirovina kako zbog saznanja o njihovoj ograničenosti tako i zbog povećane svijesti o njihovom štetnom utjecaju na okoliš. Zbog toga je jedna od glavnih zadaća ,,zelene kemije'' pronalazak ,,zelenih alternativa'', no one moraju zadovoljavati svojstva koja su do tada imali materijali dobiveni iz fosilnih sirovina te pritom trebaju biti ekonomski isplativi kako bi se mogli koristiti u široj upotrebi. Također, trebaju se pronaći i povoljna zelena otapala koja će zamijenti štetna organska otapala. Općeniti cilj priprave ekološki prihvatljivih polimera i kompozita je zamijeniti udio fosilnog sintetskog dijela nanokompozita s obnovljivom sastavnicom koja je povoljnija za okoliš, a u ovom radu pokušat će se zamijeniti čak 50 mas. % fosilnog sintetskog polimera obnovljivim biopunilom - celulozom. Celulozni nanokristali osim svojeg bio-podrijetla, imaju veliku specifičnu površinu i udio kristalnosti, male su mase te su nanometarskih veličina što ih čini vrlo poželjnim u primjeni prilikom pripreme polimernih nanokompozita. U radu su ispitana svojstva čistih kopolimera metil-metakrilata (MMA) s 2-(diizopropil-amino)etil metakrilatom (DPA) ili 2-(dimetilamino)etil metakrilatom (DMAEMA) ili 2-N-morfolinoetil metakrilatom (NMPEM) u udjelima od 10 mol. % kao i njihovih nanokompozita s celuloznim nanokristalima u udjelima od 1, 5, 10, 15, 20 i 50 mas.%. Kopolimerizacije su provedene u zelenom otapalu, dihidrolevoglukozenonu poznatijem pod nazivom Cyrene™. Obzirom da je Cyrene™ dobiven pirolizom iz biomase celuloze, kao punilo odabrala se upravo celuloza zbog očekivane dobre disperzije u matrici. Ispitana su toplinska i mehanička svojstva polimernih nanokompozita te raspodjela molekulskih masa kopolimera. Sinteze kopolimera i kompozita uspješno su provedene do visokih konverzija monomera, te su dobiveni uzorci velike molekulske mase kopolimera, osobito za kopolimere s DPA i NMPEM. Za ove sustave rezultirale su i široke raspodjele molekulskih masa koje nisu potpuno unimodalne, vjerojatno zbog izraženog gel efekta tijekom polimerizacije. Utvrđeno je da se temperature staklastog prijelaza povećavaju s udjelom celuloznih nanokristala kod kompozita s DMAEMA, dok se kod drugih smanjuju, vjerojatno zbog nepovoljnih molekulskih međudjelovanja, osim za najveće udjele nanoceluloze od 20 i 50 mas. %. Dodatkom celuloznih nanokristala kopolimeru s NMPEM mehanička svojstva se blago poboljšavaju, dok za one s DPA i DMAEMA vrijedi suprotno, osim za najmanje udjele nanoceluloze.Like many other global industries, the chemical industry in recent times is moving away from the use of fossil resources due to their limited availability and the increased awareness of their harmful impact on the environment. Therefore, one of the main tasks of "green chemistry" is to find "green alternatives," but these alternatives must meet the properties that materials obtained from fossil resouces had so far and must also be economically viable for broader use. Additionally, it is necessary to find favorable green solvents to replace harmful organic solvents. The general goal of preparing environmentally friendly polymers and composites is to replace the portion of fossil synthetic components in nanocomposites with a more environmentally friendly renewable component. In this work, an attempt will be made to replace as much as 50% by weight of fossil synthetic polymer with renewable bioreinforcement - cellulose. Cellulose nanocrystals, in addition to their bio-origin, have a large specific surface area and crystallinity, low weight, and nanometer-sized dimensions, making them highly desirable for use in the preparation of polymeric nanocomposites. The properties of pure copolymers of methyl methacrylate (MMA) with 2-(diisopropylamino)ethyl methacrylate (DPA) or 2-(dimethylamino)ethyl methacrylate (DMAEMA) or 2-N-morpholinoethyl methacrylate (NMPEM) at 10 mol.% were investigated, as well as their nanocomposites with cellulose nanocrystals at 1, 5, 10, 15, 20, and 50 wt.%. The copolymerizations were carried out in a green solvent, dihydrolevoglucosenone, better known as Cyrene™. Since Cyrene™ is derived from biomass cellulose through pyrolysis, cellulose was chosen as the filler due to the expected good dispersion in the matrix. The thermal and mechanical properties of polymeric nanocomposites were examined, as well as the molecular weight distribution of the copolymers. The synthesis of copolymers and composites was successfully carried out to high monomer conversions, and samples of high molecular weight copolymers were obtained, especially for copolymers with DPA and NMPEM. For these systems, broad molecular weight distributions that were not entirely unimodal were observed, likely due to the pronounced gel effect during polymerization. It was found that the glass transition temperatures increase with the cellulose nanocrystal content in the DMAEMA composites, while they decrease in other cases, probably due to unfavorable molecular interactions, except for the highest cellulose nanocrystal content of 20 and 50 wt.%. The addition of cellulose nanocrystals to the NMPEM copolymer slightly improves the mechanical properties, while the opposite is true for DPA and DMAEMA, except for the lowest cellulose nanocrystal content

Green synthesis of 2-substituted benzoxazole derivatives with antitumoral potential

U ovom radu opisana je konvencionalna i zelena sinteza te strukturna karakterizacija 2-supstituiranih derivata benzoksazola s potencijalnim antitumorskim djelovanjem. O-alkilirani benzaldehidi (1-4) dobiveni su reakcijom 4-hidroksibenzaldehida i 4-hidroksi-3- metoksibenzaldehida s odgovarajućim alkilirajućim reagensom. Zatim su reakcijom O-alkiliranih benzaldehida (1-4) i o-aminofenola pripravljeni derivati Schiffovih baza (5-7). Reakcijom oksidativne ciklizacije Schiffovih baza (5-7) dobiveni su 2-supstituirani derivati benzoksazola (8-9). Sinteze svih pripravljenih spojeva su provedene konvencionalno i primjenom zelenih metoda (mikrovalovima i ultrazvukom potpomognuta sinteza, mehanokemijska sinteza i sinteza u niskotemperaturnom eutektičkom otapalu). Strukturna analiza priređenih spojeva provedena je 1H- i 13C-NMR spektroskopijom.This work describes the conventional and green synthesis as well as structural characterization of 2-substituted benzoxazole derivatives with potential antitumor activity. O-alkylated benzaldehydes (1-4) were obtained by the reaction of 4-hydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde with the appropriate alkylating reagent. Derivatives of Schiff's bases (5-7) were prepared by reaction of O-alkylated benzaldehydes (1-4) with o-aminophenols. By oxidative cyclization reaction of Schiff bases (5-7), 2-substituted benzoxazole derivatives (8-9) were obtained. The syntheses of all prepared compounds were carried out conventional and by using green methods (microwave- and ultrasound-assisted synthesis, mechanochemical synthesis and synthesis in deep eutectic solvent). The structural analysis of prepared compounds were performed by 1H- and 13C-NMR spectroscopy