231 research outputs found

    Radioactivity Measurements of Ceramic Tiles Produced in Serbia

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    This paper presents the results of gamma spectrometry measurements of natural radionuclides ( 226Ra, 232Th, and 40K) in some floor and wall ceramic tiles produced in Serbia and used in homes and workplaces. The level of radioactivity of some ceramic tiles produced in Serbia by two major manufacturers–Zorka Keramika and Toza Markovic was examined. The measured mean value of the activity concentration of 226Ra, 232Th, and 40K exceeds the average values in the world for building materials with values of 67.2±6.9 Bq kg-1 for 226Ra, 57.4±4.7 Bq kg-1 for 232Th and 808±48 Bq kg-1 for 40K. Based on these calculated values, the representative level index gamma index, associated with gamma radiation, whose average value is 0.78±0.06, and annual effective dose, whose average value is 0.117±0.009 mSv y-1 for home was obtained. Estimated values fulfill all the recommendations of the European Union for building materials, thus analyzed materials are considered not to be a health hazard for the public.BPU11 : 11th International Conference of the Balkan Physical Union : Proceedings book; Aug 11 - Sep 1, 2022S01-NPNE Nuclear Physics and Nuclear Energ

    Primjena tehnologije rekombinantne DNA za pripravke kolinesteraza kao antidota i detektora organofosfata

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    To develop new avenues for synthesizing novel antidotes for organophosphate poisoning and for detection of the organophosphates, we have turned to recombinant DNA methods to synthesize cholinesterases with unusual properties. For antidotal therapy we describe mutations of the native mouse and human enzymes that allow for enhanced rates of oxime reactivation. Such enzymes, when localized in the circulation, would enable the circulating cholinesterase to become a catalytic rather than simply a stoichiometric scavenger. Hence, “oxime-assisted catalysis” provides a means for scavenging the organophosphates in the circulation thereby minimizing their tissue penetration and toxicity. Accordingly, the oxime antidote or prophylactic agent has a dual action within the circulation and at the tissue level. Second, through a novel chemistry, termed freeze-frame, click chemistry, we have used organophosphate conjugates of acetylcholinesterase as templates for the synthesis of novel nucleophilic reactivating agents. Finally, acetylcholinesterase can be modified through cysteine substitution mutagenesis and attachment of fluorophores at the substitution positions. When linked at certain locations in the molecule, the attached fluorophore is sensitive to organophosphate conjugation with acetylcholinesterase, and thus the very target of insecticide or nerve agent action becomes a detection molecule for organophosphate exposure.Razvijajući novi pristup sintezi antidota pri otrovanju organofosfatima kao i njihovu detekciju, primijenili smo metode rekombinantne DNA za pripremu kolinesteraza s neuobičajenim svojstvima. Za antidotsku terapiju istražili smo mutacije prirodnih enzima miša i čovjeka koje povećavaju brzine reaktivacije oksimom. Takvi enzimi bi po unosu u cirkulaciju postali katalitički, a ne samo stehiometrijski odstranjivači organofosfata. Na taj način “oksimom potpomognuta kataliza” omogućava čišćenje organofosfata iz cirkulacije umanjujući prodiranje organofosfata u tkiva i njihovu toksičnost. Prema tome, oksim kao antidot ima dvojaku ulogu: u cirkulaciji i na razini tkiva. S druge strane, uporabom novog sintetskog pristupa u oblikovanju biološki aktivnih spojeva poznatog kao “klik kemija” diskretnih proteinskih konformacija, organofosforilirani konjugati acetilkolinesteraze služe kao kalup u sintezi novih nukleofilnih reaktivatora. Naposljetku, acetilkolinesteraza se može mutagenezom modificirati uvo|enjem cisteina na koje se mogu vezati fluorofori. Fluorofori uvedeni na određena mjesta u molekuli acetilkolinesteraze mijenjaju svoja fluorescentna svojstva pri konjugaciji organofosfata s enzimom koji na taj način od objekta djelovanja insekticida i živčanih bojnih otrova postaje molekula za detekciju izloženosti organofosfatima

    Таксононімія логічних девіацій у нормативно-правових актах

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    Розглянуто особливості логічних девіацій у текстах нормативно-правових актів, які є складовою частиною офіційно-ділового стилю української літературної мови. Запропоновано власний підхід до класифікації виявлених у текстах чинних кодексів логічно аномальних уживань.The features of the logical deviations in the texts of laws which belong to the official style of Ukrainian literary language is under consideration. The taxonomy for the notion above in Ukrainian laws is proposed

    Bentos sjevernog dijela Velebitskog kanala (Jadransko more, Hrvatska)

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    Infralittoral and circalittoral hard bottom communities in the northern part of the Velebit Channel were investigated. The benthos was collected along six transects: three on Prvić Island (Šilo, Samonjin and Stražica) and three facing them along the Velebit mountain coast (Grmac, Žrnovnica and Kola). Three benthic biocoenoses were noted: the biocoenosis of photophilic algae, precoralligenous facies and a climax of coralligenous biocoenosis, and the biocoenosis of semi-dark caves. A total of 431 taxa were recorded: 60 taxa of algae and 371 taxa of fauna. Along the three coastal transects under Mt Velebit numerous submarine freshwater springs (vruljas) are present. The results were compared using two statistical methods: the application of the Sørensen index of similarity and cluster analysis. The most topographically and geomorphologically similar transects were Šilo and Samonjin, while StraŽica and Žrnovnica were the most distant.Istraživane su bentoske zajednice čvrstog dna u infralitoralu i cirkalitoralu u području sjevernog dijela Velebitskog kanala. Obrađeno je šest profila od čega tri na otoku Prviću (Šilo, Samonjin i Stražica), a tri nasuprot, na kopnu (Grmac, Žrnovnica i Kola). Utvrđene su tri biocenoze: biocenoza fotofilnih alga, pretkoraligenski aspekt i klimaks stadij koraligenske biocenoze te biocenoza polutamnih špilja. Na svih šest istraživanih profila ukupno je utvrđeno 60 biljnih i 371 životinjska svojta. Duž profila podno Velebita nalaze se brojne vrulje. Sørensenovom metodom i klaster-analizom obrađ|eni su rezultati istraživanja. Najveća sličnost u sastavu flore i faune obrađenih biocenoza utvrđena je među profilima Šilo i Samonjin, a najmanja među profilima Stražica i Žrnovnica

    The influence of adding of flaxseed oil to sunflower oil on the content of tocopherols and carotenoids in blended edible oils

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    Blending vegetable oils of different composition and properties is one of the simplest methods for creating new specific products with the desired properties, which increases their commercial application and improves their nutritional quality. The effect of blending vegetable oils on tocopherols and carotenoids content was examined. Refined sunflower seed oil (S) and cold pressed flaxseed oil (F) were used in the experiment. These oils are blended in three different content of mass: sample 70S:30F (70% S and 30% F), sample 50S:50F (50% S and 50% F) and sample 30S:70F (30% S and 70% F). The results showed significant differences in the content of total tocopherols and total carotenoids between the two oils used for the preparation of three blended oils. Refined sunflower seed oil contains higher amounts of tocopherols and fewer amounts of carotenoids compared to cold pressed flaxseed oil in which the content of tocopherols is lower and the content of carotenoids is higher. In the obtained blends of edible vegetable oils, the content of total tocopherols ranged from 387.96 to 447.83 mg/kg while the determined total carotenoids content (as B-caroten) ranged from 3.11 to 5.63 mg/kg. By blending refined oil of sunflower seed and cold pressed oil of flax-seed, the balance of the parameters studied is contributed. The research in the work showed that the blending of vegetable oils provides the possibility of modulating their composition, and therefore of nutritive quality

    The determination of patulin in apple juice

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    Istraživana je mogućnost kvantitativnog određivanja patulina tu jabučinom soku. Postupak je uključivao ekstrakciju patulina iz soka s pomoću etil-acetata, pročišćavanje ekstrakata kromatografijom na stupcu silikagela te kvalitativno i kvantitativno određivanje s pomoću tankoslojne kromatografijc. Izlaganjem ploča za tankoslojnu kromatografiju koncentriranim parama amonijaka dobiveni su derivati s intenzivnijom fluorescencijom, što je olakšalo kvantitativno fluorodenzitometrijsko određivanje patulina. Granična koncentracija, što se s pomoću upotrijebljene metode mogla odrediti, bila je 200 ng čistog patulina i 100 µg patulina na litru soka. Djelotvomost postupka bila je od 78 do 110%, a prosječna vrijednost djelotvornosti bila je 98%.A quantitative method for the determination of patulin in apple juice was examined. The procedure involved patulin extraction from apple juice with ethyl acetate, clean-up with column chromatography and preparative thin-layer chromatography. Fluorescent derivatives, obtained by exposure of patulin on chromatographic plates to concentrated ammonia fumes, permitted a convenient quantitative fluorodensitometric assay of patulin by means of the fluorescence quenching method. The detection limits were 200 ng of pure patulin and 100 µg of patulin per litre of apple juice. The recoveries of added patulin ranged from 78 to 110.4 per cent, with a mean recovery of 97.8 per cent

    Artemia salina larvae as a test organism in research on mycotoxin synergism

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    lstraživan je utjecaj koncentracije i vremena djelovanja aflatoksina B1 i diacetoksiscirpenola na larve račića Artemia solina, u rasponu temperature od 20 do 35°C. Određeno je toksičko djelovanje za svaki mikotoksin zasebno i u kombinaciji različitih koncentracija. Nakon što su određene LC50 i T50 vrijednosti, dokazan je sinergistički odziv na osnovi smanjenja koncentracija za podjednak toksički učinak.The effect of concentration and contact time of two mycotoxins, aflatoxin 81 and diacetoxyscirpenol was studied on the larvae of Artemia salina. These organisms are sensitive to sub-microgram quantities of the toxins and can be used as bioassay test organisms. In a study of aflatoxin 81 and diacetoxys-cirpcnol synergism in acute toxicity, the LC50 values of toxin pairs exhibited a distinct increase in toxicity
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