Primena naprednih materijala u biotehnologijama

Materials matter: any breakthrough that changes society owes its success to the molecular building blocks used to create it. Advanced materials are essential to economic security and human well-being, with applications in industries aimed at addressing challenges in clean energy, national security, and human welfare. Therefore, speeding up the pace of development and implementation of advanced material systems is critical for achieving global competetiveness in the 21st century. In recent decades, significant progress has been evident in the processing and properties of materials intended for use in various biotechnologies, biomedicine, and dentistry. This volume specifically introduces new materials based on natural and synthetic substances with improved properties relevant to applications in biomedicine and biotechnologies.Materijali su važni: svaki napredak koji menja društvo duguje svoj uspeh molekularnim gradivnim blokovima koji se koriste za njegovo stvaranje. Napredni materijali su od suštinskog značaja za ekonomsku bezbednost i ljudsko blagostanje, sa primenom u industrijama usmerenim na rešavanje izazova u pogledu čiste energije, nacionalne bezbednosti i ljudskog blagostanja. Stoga je ubrzanje tempa razvoja i implementacije naprednih materijalnih sistema kritično za postizanje globalne konkurentnosti u 21. veku. Poslednjih decenija evidentan je značajan napredak u obradi i svojstvima materijala namenjenih upotrebi u različitim biotehnologijama, biomedicini i stomatologiji. Ova tematska sveska posebno predstavlja nove materijale zasnovane na prirodnim i sintetičkim supstancama sa poboljšanim svojstvima relevantnim za primenu u biomedicini i biotehnologiji

Hydroxyapatite/iron oxide nanocomposite prepared by high energy ball milling

Nanocomposites (HAp/iron oxide), made of hydroxyapatite (HAp) and ferrimagnetic iron oxide, were synthesized by high-energy ball milling a mixture consisting of iron oxide nanoparticles and the starting materials used for the HAp synthesis: calcium hydrogen phosphate anhydrous (CaHPO4), and calcium hydroxide (Ca(OH)2). Two HAp/iron oxide samples with the magnetic phase content of 12 and 30 wt.% were prepared and their microstructure, morphology and magnetic properties were analysed by X-ray diffraction and transmission electron microscopy. Furthermore, the measurement of particle size distribution was performed by laser scattering, and temperature/field dependence on magnetization was determined. X-ray diffraction data confirmed the formation of two-phased samples (HAp and spinel iron oxide) without the presence of any other parasite phase. The shape of particles was nearly spherical in both samples, ranging from only a few to several tens of nanometres in diameter. These particles formed agglomerates with the most common value of the number-based particle size distribution of 380 and 310 nm for the sample with 12 and 30 wt.% of iron oxide, respectively. Magnetization data showed that both HAp/iron oxide composites had superparamagnetic behaviour at room temperature. © 2019 University of Novi Sad, Faculty of Technology. All rights reserved

Predgovor

Pred vami je nova revija Ars & Humanitas – revija za umetnost in humanistiko, področji, ki ju v sodobni družbi pogosto ločuje absurdna potreba po natančnem zamejevanju medsebojnih razmerij, pristojnosti in vsebin, raziskovalnih pristopov in metodologij dela. Ars & Humanitas želi preseči to razločenost. Ars v humanistični tradiciji razumemo kot umetnost, a tudi kot veščino, znanje, znanost. Humanitas kot humanistiko, vsestransko izobrazbo, omiko in plemenitost duha. Eno brez drugega v resnici ne more obstajati. Razdrobljenost intelektualnih horizontov pa je žal še veliko večja. Tudi znotraj same humanistike postaja drobljenje znanstvenega in raziskovalnega prostora na ozko specializirane stroke resna zavora v razvoju humanističnih ved. Ob vse večjem številu specializiranih, v pristopu teoretsko in diskurzivno strogo zamejenih znanstvenih publikacij, njihovih tvorcev in bralcev, je potrebno ponuditi več prostora za nove, interdisciplinarno zasnovane znanstvene revije. Ars & Humanitas hoče biti prav to – spodbuditi želi povezovanje družboslovnih in humanističnih strok, okrepiti dialog med različnimi teoretskimi orientacijami, odpirati izvirne pristope k obravnavi tem, opozarjati na aktualne vidike interferenc in skrbeti za promocijo humanistike tako v strokovnih krogih kot v širši javnosti. Zasnova revije je tridelna: v nosilnem tematskem bloku (študije) bodo objavljene študije domačih in tujih strokovnjakov, ki bodo odražale različne pristope k izbrani temi, medtem ko bo odprti blok (varia) namenjen prispevkom, ki so v določenem trenutku posebej aktualni ali ponujajo svež pogled na obravnavano temo. Tretji del bo namenjen recenzijam najnovejših in najaktualnejših znanstvenih publikacij s širšega humanistično družboslovnega področja. Posebno pozornost bo revija namenjala nacionalni in regionalni specifiki humanistike in družboslovja znotraj Evropske unije, pa tudi promociji nacionalnih kultur in umetnosti. Skladno s tem je eno od pomembnih poslanstev revije Ars & Humanitas krepitev zavesti o pomenu jezika v razvoju humanistike, saj jezik v humanističnih znanostih presega vlogo orodja sporočanja in je neločljivo povezan s samim razvojem humanističnih znanosti. Revija je zasnovana na večjezičnosti, posebno skrb pa bo posvečala slovenski humanistiki in razvoju strokovne terminologije v slovenskem jeziku. V trenutku, ko globalizacija nezadržno spodjeda same temelje kulturne in intelektualne različnosti, ko sodobni razvojni trendi sleherno dejavnost vse pogosteje merijo z enotnim vatlom produktivnosti, ko nam celo nekateri uradni zastopniki znanosti poskušajo na različne načine vcepiti prepričanje, da humanistika postaja odveč in neuporabna, je vsak korak v nasprotno smer vreden pozornosti in spodbude. Ustanovitev nove revije za umetnost in humanistiko je nedvomno tak korak

Uvodnik v tematski sklop

V zadnjem času smo priča povečanemu zanimanju za telo v vsakdanjem življenju in v naših vsakdanjih praksah, pa tudi v družboslovnih in humanističnih raziskavah in analizah. Pri tem zagotovo prednjačijo mediji, ki nas zasipavajo s podobami idealnih, zdravih, zagorelih, lepih, vitkih teles, ki so tako rekoč povprečnemu človeku/ženski nedosegljive. Ti isti mediji nas po eni strani posiljujejo z mnogimi dobrotami, recepti, hrano, po drugi pa s podobami vitkih teles, kar skorajda nujno vodi do frustracij ali pa do različnih oblik trpinčenj lastnega telesa. Ta se lahko kažejo v obliki občasnega hujšanja, anoreksije, bulimije, kompulzivnega prenajedanja, ortoreksije, bigoreksije (pretirane fizične aktivnosti) ipd. Če pa to ni učinkovito ali ni zadosti hitro, se je tudi za težave našlo zdravilo – oz. zdravnik – lepotni kirurg, ki nam izreže, zmanjša ali poveča tisto, kar hočemo oz. česar nočemo. Poraslo je tudi zanimanje za zdravo telo – ljudje hočejo, da bi bili videti zdravo, se počutiti zdravo, zato jejo zdravo hrano, se ukvarjajo s športom, skratka skrbijo za svoje telo. Telo je hkrati del posameznika/posameznice, obenem pa je lahko njen/ njegov objekt oz. projekt – če se odločimo, ga bomo oblikovali tako, da bo krepko ali krhko, obilno ali skoraj shirano, lahko si okrepimo/povečamo ali zmanjšamo ta ali oni del, možnosti so stvar naše domišljije in časovno finančnih možnosti. Ta interes je, kot je opozoril že Bourdieu (1984), najbolj prisoten pri t.i. novem srednjem razredu, najverjetneje se je v zadnjem času razširil tudi na druge sloje. Telo pa ne predstavlja le stvar zanimanja posameznikov in posameznic ampak tudi oblasti oz. politike. Če pritrdimo Foucaultu, se je oblast pravzaprav vedno zanimala za telesa svojih podrejenih. Že davno tega so bila telesa predmet nadzorovanja in kaznovanja, telesne kazni so bile prve oblike kaznovanja neubogljivega ljudstva in za razliko od danes so bila ta kaznovanja vsem na ogled in v opozorilo. Zdi se, da oblast/politika teles ni nikoli izpustila iz svojega primeža, le da so se oblike nadzorovanja in kaznovanja spreminjale/spremenile – predvsem najbrž to velja za ženska telesa. Telo je bilo, je in bo predmet zanimanja različnih ved in polj. Čeprav je bilo videti, da si ga je najprej za ekskluzivno polje svojega delovanja privzela medicina, pa se z njim ukvarjajo (je predmet njihovega raziskovanja) tudi druge vede oz. znanstvene discipline od sociologije in antropologije, študijev spola, umetnostne zgodovine, literarne zgodovine in drugih. Večkrat ponovljena modrost, da nimamo svojega telesa, temveč smo telo, je v sodobnem družbosovju in humanistiki postala prežvečena puhlica. In prav zato, ker nas vabi v objem najbolj duhamornega vulgarnomaterialističnega redukcionizma, jo je vredno od časa do časa premisliti. Imeti telo ali biti telo? Frommovska dilema sploh ni na izbiro: človeštva si ni mogoče predstajati v breztelesnem ali bognedaj! raztelešenem stanju. Celotno človeštvo, ki edino ustvarja, posreduje, uporablja in preobrača simbole, skratka “simboli”, če smeva uporabiti glagol, ki si ga je neuspešno zamislil Leslie White, ustvarja neskončne nize neopredmetenih zamisli, a nikakor ne more ustvariti enega samega simbola, torej predmeta, ki omogoča reprezentacijo, tako da ga postavimo na mesto nečesa drugega, ne da bi se za to pomučilo v potu svojega obraza. Še več, največje skrivnosti, kar si jih lahko zamislimo, izhajajo iz nizov telesih drž in sporočil, ki jih prevzemamo od drugih brez simboljenja. Če smo še pred tremi desetletji govorili skorajda samo o strukturah (ne da bi dobro premislili paleto pomenov tega danes skorajda pozabljenega koncepta), pa pred desetletjem in pol o tekstih in njihovem »branju«, si danes ne moremo predstavljati humanistične razprave, ki ne bi umeščala razumevanja človeške sporočilnosti na raven neposrednih človeških dejavnosti. Pri tem v glavnem ne gre za obujanje pragmatizma, ki bi ga spodbujala prevlada anglosaške teoretske misli, niti za slepo sledenje vmes skorajda pozabljenim spoznanjem o telesnem ustroju človeških svetov Merleau-Pontyja, temveč za premik, v katerega nas sili soočanje z dogajanji v resničnem svetu, na katera se moramo ustrezno odzvati kot raziskovalci in raziskovalke. Pričujoči tematski sklop revije Ars et Humnitas prinaša pestro paleto različnih pristopov in prikazov telesa v polju družboslovja in humanistike od teoretskih razprav v okviru post-fenomenološke sociologije telesa, tematiziranja telesa v odnosu do zdravja in plesa, pa vse do razprav o lepotnem idealu telesa v florentinskem slikarstvu, golote in spola v žanru akta ter pomena fotografij (ki predstavljajo zamrznjena telesa), s pomočjo katerih je mogoče odstirati osebne zgodovine

Badlands in volcano-clastic rocks: examples from Serbia and Hungary

Badlands can develop under different climatic conditions ranging from arid to humid on materials that have a specific combination of physico-chemical properties depending on their mineralogical composition. Mostly these materials are fine-grained terrigenous, lacustrine or marine sediments of different age. However, badlands can also form in volcano-clasitc materials, and Cappadocia badlands in Turkey is the most prominent example. Less known in the literature are two sites also developed in this type of sediments: Đavolja Varoš, on Radan Moutain in SE Serbia and the Kazár badlands in NW Hungary. The Đavolja Varoš badlands, 0.7 km2 in size is formed by the intensive development of rills and gullies on slopes built from thick volcano-clastic material. The initial relief is reduced only to sharp ridges between adjacent gullies. This badland is developed in dacito-andesitic poorly-consolidated poorly-sorted tuffs. The weathering processes are intense and governed by high intensity precipitation and prolonged drying periods. The reddish earth pyramids built of these erodible materials are protected by the cap rock. Loss of balance and fall of the protective cap rock accelerates the erosion. The smaller Kazár badlands covering the area of 1ha are developed in rhyolitic poorly-consolidated highly porous tuffs. Rills and gullies are the dominant geomorphic processes and the weathering is dominated by freeze-thaw processes. At the Kazár badlands earth pyramids are not protected with the cap rock and weathering, disintegration and sheet wash erosion intensively shape the landscape. Although the materials differ slightly in composition, both being poorly sorted, clay-size rich materials make them sensitive to erosion, proving once more the importance of material composition, in this case namely grain size including sorting and mineralogical composition, for badlands development and future evolution

Ternary flower-structured nanoferrites with polyvalent cations for potential applications in electrochemical sensors and magnetic hyperthermia

Nanoferrites have been intensively studied because of the possibility of their use in the fields such as medicine, sensors, environmental, agriculture, weather, battery, etc. Often, they are used as modal systems in fundamental science to study physical and chemical phenomena at the nanoscale. Various pathways were applied for the synthesis of nanoferrites with the same composition were led to different microstructure and structure properties, which further influenced magnetic, electric, catalytic and other properties. Consequently, with a controlled synthesis, it is possible to tune the properties of nanoferrites important for applications. On the other side, properties can be controlled by changing chemical composition. In ternary nanoferrites often deviation of stoichiometry accompanied with cation polyvalence was found [1]. The main idea of our work was the application of the polyol-modified method developed for the synthesis of flower-structured iron oxides nanoparticles in the preparation of ternary ZnxMnyFezO4 samples to seek a correlation among chemical composition and microstructure with magnetic hyperthermia efficiency and electrochemical properties. A series of the samples ZnxMnyFezO4 was prepared by polyol process using a slightly modified procedure described in ref [2]. By elemental analysis performed using the ICP technique, the content of cations in the formula unit was determined as follow: Zn0.640Fe2.360O4, Zn0.394Mn0.138Fe2.468O4, Zn0.309Mn0.240Fe2.451O4, Zn0.182Mn0.344Fe2.474O4, Zn0.098Mn0.447Fe2.455O4, Mn0.624Fe2.376O4. The ICP results pointed to the presence of multivalent cations, Mn2+/Mn3+ and Fe3+/Fe2+. Zn has stable valence +2, while the oxidation state of +4 for Mn couldn’t be excluded. Different oxidation states of Mn and Fe and possible deviation of stoichiometry, can create physical effects [3] and make ZnxMnyFezO4 suitable material in practical applications, used for modification of working electrodesin electrochemical sensors. Consequently, we have performed basic electrochemical characterisation of nanoferrites. Cyclic voltammetry of 5 mM K3[Fe(CN)]6/K4[Fe(CN)]6 (1:1) in 0.1 M KCl at bare SPCE and ZnxMnyFezO4-modified SPCE showed that the highest peak current (Ip) was achieved using a Zn0.098Mn0.447Fe2.455O4/SPCE. The Ip was about 22% higher than the bare electrode. X-ray diffraction pattern showed the samples were single-phase crystallising in spinel structure type. Morphology and particle size of the samples were analysed from TEM micrographs. Particles (or crystallites) were agglomerated in a flower-like structure (Figure 1). The diameter of the flowers was around 50-60 nm. Superparamagnetic behaviour of the samples was found from magnetization versus field measurements (hysteresis loops). Prepared samples were in the form of stable colloids with hydrodynamic diameter in the range of 50-120 nm. The heating properties of the samples were analysed from the data of specific absorption rate (SAR), Figure 1b. The highest SAR value was found for Zn0.098Mn0.447Fe2.455O4. The best heating efficiency and electrochemical properties had the same sample. To correlate ZnxMnyFezO4 different efficiency in magnetic hyperthermia and electrochemical sensor applications with parameters like cation distribution in two non-equivalent spinel crystallographic sites (space group, Fd-3m), local distortion on cationic sites, crystallite size and defects, an integrated study of samples structure and microstructure is in progress

The impact of groove edge temperature and heat input on the structure and hardness of the heat affected zone of steel 460 NL1 welded joint

Polazne strukture i vreme hlađenja u temperaturnom intervalu 800 - 500°C (t8/5) imaju presudan uticaj na strukture i osobine zone uticaja toplote zavarenih spojeva čelika. Na vreme hlađenja t8/5 između ostalog, utiče i temperatura ivice žleba. Zbog zagrevanja toplotom luka temperatura ivice žleba duž spoja raste, zbog čega se vreme hlađenja zone uticaja toplote produžava. Samim tim, duž spoja se produžava i vreme hlađenja t8/5. U radu su prikazani rezultati merenja temperatura ivica žleba pri zavarivanju višeprolaznog sučeonog spoja mikrolegiranog čelika P 460 NL1. Određen je uticaj ovih temperatura na vremena hlađenja t8/5 i na makro i mikrostrukture i tvrdoće u zoni uticaja toplote ovog zavarenog spoja.The starting structures and cooling times in the temperature range 800 - 500°C (t8/5) have a decisive influence on the structures and properties of the heat affected zone of steel welded joints. At the cooling time t8/5, inter alia, the groove edge temperature has an effect. Due to heating by the electrical arc, the groove edge temperature along the joint, increases, resulting in extending of the cooling time of the heat affected zone. Therefore, the cooling time t 8/5 is extended along the joint. The paper presents the measurement results of the groove edges temperature during the welding of the multilayer joint of the microalloyed steel P 460 NL1. The influence of these temperatures on the cooling time t8/5 and on the macro and microstructure and hardness in the heat affected zone of this welded joint was determined

Supplementary material for the article: Samelak, I.; Balaban, M.; Vidović, N.; Koljančić, N.; Antić, M.; Šolević-Knudsen, T.; Jovančićević, B. Application of Alkane Biological Markers in the Assessment of the Origin of Oil Pollutants in the Soil and Recent River Sediments (River Vrbas, Bosnia and Herzegovina). Journal of the Serbian Chemical Society 2018, 83 (10), 1167–1175. https://doi.org/10.2298/JSC180501061S

Supplementary material for: [https://doi.org/10.2298/JSC180501061S]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2237

Determination of bisphenol A traces in water samples from the Vrbas River and its tributaries, Bosnia and Herzegovina

The bisphenol A (BPA) concentration was determined in 12 surface water samples of the Vrbas River and its five tributaries. The samples were taken in the area that belongs to the city of Banja Luka (Bosnia and Herzegovina). BPA was isolated using micro liquid-liquid extraction followed by derivatization and gas chromatography-mass spectrometry analysis (GC-MS). Silylation was used as a derivatization method to increase volatility and allow the GC-MS determination of BPA. The limits of detection (LOD) and quantification (LOQ), obtained by validating the procedure, were determined at 4 and 10 ng L-1, respectively. The concentrations of BPA were ranged between 33 and 354 ng L-1, and all were above the LOQ value. The lowest amount of BPA was found in the sample collected in the river Vrbas, near Švrakava estuary upstream from the city of Banja Luka. The highest concentration of BPA was recorded at the confluence of the Crkvena and Vrbas rivers, which is located in the city center. This study shows that population and human activity could affect the level of BPA in the environment

Application of alkane biological markers in the assessment of the origin of oil pollutants in the soil and recent river sediments (River Vrbas, Bosnia and Herzegovina)

In this paper, an attempt was made to contribute to the use of biological markers, n-alkanes, and polycyclic alkanes of the sterane and terpane type, in the assessment of the source of oil pollutants in the environment using the example of the correlation between recent river and coastal sediments,. Four samples of recent river sediments of the Vrbas River and four samples of adjacent bank sediments (soils), in the part of the River that belongs to the city of Banja Luka (Bosnia and Herzegovina) were analyzed. In the alkane fractions of isolated extracts, a bimodal distribution of the n-alkanes was observed. Lower homologues dominated in the recent river sediments with maximum at C15, but higher n-alkanes dominated in the soil samples, with a maximum at n-C29 or at n-C31. The higher concentration of steranes and terpanes with oil type distributions in the recent/fresh river sediments (compared to the bank sediments) represents evidence that lower n-alkanes originate from oil sources. The higher content of total hydrocarbons in the recent river sediments than in the bank sediments further confirms this conclusion. At the same time, these fundamental considerations provide evidence that oil pollution primarily occurred in the water flow and then the oil pollutants propagated towards the riverbank