Analiza koncentracije toksičnih i esencijalnih elementa (as, cd, cu, cr, hg, ni, pb, sr, zn) u zooplanktonu sa šaranskog ribnjaka

U poslednjih 20 godina zagađivanje slatkovodnih ekosistema toksičnim elementima je u porastu širom sveta. Zagađenjem su pogođeni pre svega izvori za vodosnabdevanje stanovništva i životno okruženje, ali i industrija kao i privreda uopšte. Međutim zbog perzistentnosti i transfera kroz lance ishrane i potencijalnog akumuliranja u ribama i drugim vodenim organizmima koji se koriste u ishrani, toksični elementi predstavljaju stalnu pretnju ljudskom zdravlju. Zagađivanje naših reka teškim metalima nameće pitanje ne samo zdravstvene ispravnosti riba iz reka već i riba iz ribnjaka obzirom da se većina šaranskih ribnjaka napaja vodom iz sistema kanala DTD. Cilj ove studije je bio da se analizira koncentracija 9 elemenata u zooplanktonu koji predstavlja značajnu prirodnu hranu šarana u poluintenzivnom sistemu gajenja. Istraživanje je obavljeno na 4 ribnjačka objekta, tokom dva ciklusa gajenja šarana, od juna do oktobra, na ribnjaku „Despotovo“. Uzorci zooplanktona za analizu elemenata su uzimani sa tri tačke u svakom jezeru pomoću planktonske mrežice veličine 250 µm jednom mesečno. Na ovaj način su sakupljene samo krupnije veličinske klase zooplanktona (Cladocera i Copepoda), koje šaranska mlađ najviše konzumira. Sa svakog jezera je uziman po još jedan uzorak zooplanktona za kvantitativnu i taksonomsku analizu. Koncentracija elemenata je analizirana induktivno spregnutom plazma masenom (ICP-MS) i optičkom emisionom spektrometrijom (ICP-OES). Rezultati su obrađeni jednofaktorijalnom analizom varijanse (ANOVA) u statističkom programu PAST 3.06. Značajnost razlika testirana je primenom Tukey’s post hoc testa. Podaci su klasifikovani na prolećni, letnji i jesenji aspekt tokom jednog proizvodnog ciklusa. Cladocera su dominirale u populaciji zooplanktona, osim u junu kada su Copepoda bile zastupljenije. Iako nije bilo značajnih razlika u koncentraciji elemenata između godina, osim za Cu i Sr, uočen je karakterističan sezonski obrazac kretanja koncentracija elemenata tokom celog istraživanja. Prolećni i jesenji aspekti u 2012 su bili veći nego u 2013, dok je letnji aspekt u 2013 bio viši nego u 2012. godini. Izuzetak je bila koncentracija Zn u zooplanktonu gde je situacija bila obrnuta. Povišene vrednosti većine toksičnih metala u zooplanktonu na ribnjaku Despotovo se mogu objasniti relativno velikim afinitetom egzoskeleta Cladocera za većinu dvovalentih jona. Nakon adsorbcije elementi na površini ljuštura ovih životinja, tokom vremena bivaju absorbovani kroz telesni zid u unutrašnje organe. Neke studije čak navode da površinski akumulirani kontaminanti na plenu mogu biti dostupniji predatorima od onih akumuliranih u tkivima, zbog niskog pH i visokog nivoa jonske kompleksacije koji vladaju na mestu abstorpcije, u digestivnom traktu većine životinja, Ovi rezultati nameću zaključak da je u budućim istraživanjima kontaminacije vodenih ekosistema i riba poželjno uključiti analize ne samo vode kao izvora toksičnih elemenata, već i odgovarajućih izvora hrane (plena) koji, kako je pokazano, sadrži potencijal ne samo za značajnu akumulaciju elemenata već i njihovu potencijalnu veću biodostupnost konzumentima

Antioxidant, Antimicrobial and Antiproliferative Activities of Five Lichen Species

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells

Phytochemical and antioxidant studies of Laurera benguelensis growing in Thailand

The aim of this study was to investigate metabolites of the lichen Laurera benguelensis. A high-performance liquid chromatographic (HPLC) method has been developed for the characterization of xanthones and anthraquinones in extracts of this lichen. Lichexanthone, secalonic acid D, norlichexanthon, parietin, emodin, teloschistin and citreorosein were detected in the lichen samples, which were collected from two places in Thailand. Components of the lichen were identifed by relative retention time and spectral data. This is the frst time that a detailed phytochemical analysis of the lichen L. benguelensis was reported and this paper has chemotaxonomic signifcance because very little has been published on the secondary metabolites present in Laurera species. Some of the metabolites were detected for the frst time in the family Trypetheliaceae. The results of preliminary testing of benzene extract and its chloroform and methanol fractions showed that all samples showed a weak radical scavenging activity. The chloroform extract showed the highest antioxidant activity

6th International Conference The Future of Information Sciences INFuture2017: Integrating ICT in Society

This is the sixth publication in the series of biennial international conferences, The Future of Information Sciences (INFuture) organised by the Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb. This year it is co-organised with the Miroslav Krleža Institute of Lexicography. The title of the conference is INFuture2017: Integrating ICT in Society. The conference explores the influence the information and communication sciences have on the society as a whole.This is the sixth publication in the series of biennial international conferences, The Future of Information Sciences (INFuture) organised by the Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb. This year it is co-organised with the Miroslav Krleža Institute of Lexicography. The title of the conference is INFuture2017: Integrating ICT in Society. The conference explores the influence the information and communication sciences have on the society as a whole

6th International Conference The Future of Information Sciences INFuture2017: Integrating ICT in Society

This is the sixth publication in the series of biennial international conferences, The Future of Information Sciences (INFuture) organised by the Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb. This year it is co-organised with the Miroslav Krleža Institute of Lexicography. The title of the conference is INFuture2017: Integrating ICT in Society. The conference explores the influence the information and communication sciences have on the society as a whole.This is the sixth publication in the series of biennial international conferences, The Future of Information Sciences (INFuture) organised by the Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb. This year it is co-organised with the Miroslav Krleža Institute of Lexicography. The title of the conference is INFuture2017: Integrating ICT in Society. The conference explores the influence the information and communication sciences have on the society as a whole