Fractionation of soil phosphorus in a long-term phosphate fertilization

The changes in inorganic and organic phosphorus (P) fractions of soil resulting from long-term fertilization (40 years) were investigated. In order to improve understanding of the sink and sources of phosphorus, P-fractions were extracted from soil samples of 0-30 and 30-60 cm depth with different amounts of monoammonium-phosphate (MAP) and then determined. Stagnosol was the type of the studied soil. Phosphate fertilizer was applied in 26, 39 and 52 kgP/ha amounts during the period of 40 years. Samples were subjected to sequential extraction according to the modified Chang and Jackson method and BCR (Community Bureau of Reference) sequential extraction procedure in order to extract different forms of phosphorus. The Certified Reference material CRM 684 (River Sediment Extractable Phosphorus) was used to provide accuracy of the instrument and both used methods. Furthermore, the association of phosphorus with substrates was provided by comparison of the results of sequential methods of phosphorus species with the sequential extraction of metals (Fe, Al, Mn and Ca). Results of continuous fertilization during 40 years indicated the increase of all the phosphorus forms in the soil except of phosphorus bound to calcium and organic phosphorus. Application of higher amounts of P-fertilizer resulted in dominance of Al-P fraction in studied soil which indicated that this fraction was the most responsible for the migration of phosphorus along the soil profile

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

Redox properties of alkyl-substituted 4-aryl-2,4-dioxobutanoic acids

© 2017 J. Serb. Chem. Soc. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (https://creativecommons.org/licenses/by-nc-nd/4.0/).Redox properties of a set of aryldiketo acids (ADKs), small organic molecules that comprise 2,4-dioxobutanoic acid moiety, were studied. Along with well-known HIV-1 integrase (IN) inhibition, ADKs exert widespread biological activities. The aim of this work was to evaluate effects of aryl substitutions on properties of dioxobutanoic moiety that is involved in key interactions with metal ions within active sites of target enzymes. The effect of pH on electronic properties of nine congeners was examined using cyclic voltammetry and differential pulse polarography. Compounds were chosen as a simple set of congeners, bearing Me-groups on phenyl ring which should not be involved in electrochemical reactions, leaving diketo moiety as sole electrophore. Substitution pattern was systematically varied, yielding a set having different torsion between phenyl ring and aryl keto group (Ar-C(O)). Protonation state of ADKs at different pH values was determined from experimentally obtained pKas. The results showed that the equal number of protons and electrons is involved in the oxidation and reduction reactions at the surface of electrode. Quantitative linear correlations between reduction potentials and energies of frontier orbitals, calculated for neutral, monoanionic and corresponding radical anionic species, and steric parameter were found.Peer reviewe

Opis przypadku — występujący rodzinnie wewnątrzczaszkowo germinoma

Background. Intracranial germinomas (ICG) are uncommon brain neoplasms with extremely rare familial occurance. Since ICG invades hypothalamus and/or pituitary, the endocrine dysfunction is one of the common determinants of these tumors. We presented two brothers with the history of ICG. Patient 1 is a 25-year-old male who had been suffering from the weakness of the right half of his body at the age of 18. Cranial MRI revealed mass lesion in the left thalamus. He underwent neurosurgery, tumor was removed completely. Histopathological (HP) and immunohistochemical analyses verified the diagnosis of pure germinoma. He experienced complete remission of the tumor after a radiation therapy. At the age of 22 the diagnosis of isolated growth hormone deficiency (IGHD) was established and GH replacement was initiated. Patient 2 is a 20-year old boy who was presented with diabetes insipidus at the age of 12. MRI detected tumor in the third ventricle and pineal region. After the endoscopic tumor biopsy the HP diagnosis was pure germinoma. He received chemotherapy followed by radiotherapy, and treated with GH during childhood. At the age of 18 GH replacement was reintroduced. A six month follow-up during the next two years in both brothers demonstrated the IGF1 normalization with no MRI signs of tumor recurrence. Conclusion. To the best of our knowledge so far, only six reports have been published related to familial ICG. The presented two brothers are the first report of familial ICG case outside of Japan. They are treated successfully with GH therapy in adult period. Wstęp: Rozrodczaki wewnątrzczaszkowe (intracranial germinomas, ICG) to rzadkie nowotwory mózgu, a szczególnie rzadko stwierdza się ich występowanie rodzinne. W związku z tym, że ICG zajmuje podwzgórze i/lub przysadkę mózgową, zaburzenia endokrynologiczne są jednym z najczęstszych wyznaczników obecności tych guzów. W pracy przedstawiono dwóch braci z ICG. Pacjent 1 to 25-letni mężczyzna, u którego w wieku 18 lat wystąpiło osłabienie mięśni po lewej stronie ciała. Badanie metodą rezonansu magnetycznego (MRI) czaszki ujawniło masę w lewym wzgórzu. Chorego poddano zabiegowi neurochirurgicznemu, podczas którego guz został całkowicie usunięty. Badania histopatologiczne i immunohistochemiczne potwierdziły rozpoznanie czystej postaci rozrodczaka. Po radioterapii nastąpiła całkowita remisja guza. W wieku 22 lat u chorego zdia­gnozowano izolowany niedobór hormonu wzrostu (isolated growth hormone deficiency, IGHD) i wdrożono terapię zastępczą hormonem wzrostu (growth hormone, GH). Genetyczna analiza molekularna tkanki guza wykazała mutację w eksonie 2 w genie KRAS. Pacjent 2 to 20-letni mężczyzna, u którego w wieku 12 lat stwierdzono moczówkę prostą. W badaniu MRI wykryto guz w okolicy trzeciej komory i szyszynki. Po ocenie histopatologicznej materiału pobranego za pomocą biopsji endoskopowej postawiono diagnozę czystego rozrod­czaka. U chorego zastosowano chemioterapię, a następnie radioterapię, a także podawano GH w okresie dzieciństwa. W wieku 18 lat u chorego wznowiono terapię GH. Sześciomiesięczna obserwacja obu braci w następnych 2 latach wykazała normalizację IGF1 przy braku objawów nawrotu guza w badaniu MRI. Wnioski: Według najlepszej wiedzy autorów dotychczas opublikowano 6 doniesień na temat rodzinnego występowania ICG. Przed­stawieni w niniejszej pracy bracia są pierwszym opisanym przypadkiem rodzinnego ICG poza Japonią. W okresie dorosłym chorzy są leczeni GH z dobrym skutkiem

CROSS DOCKING IMPLEMENTATION IN DISTRIBUTION OF FOOD PRODUCTS

The research domain of this paper is food distribution improvement using the logistic concept of cross docking. The study purpose is to explore, analyse and demonstrate effects of cross docking implementing in business trading company and the factors influencing to implementation effectivness, as well. The metodology used in the study includes the actual logistics and supply chain management literature review and the real-world study with the concept implementation. Thе main achieved results are that under defined circumstances cross docking can be suitable tool for food distribution improvement and valuable for the company’s competitivness increasing. The validity of the cross docking implementation is reflected in multiple (direct and indirect) benefits not only for the company, but also for the whole supply chain

Degradation of benzodiazepines using water falling film dielectric barrier discharge reactor

Classical methods of wastewater treatment are often not suitable for the treatment of pharmaceutical waste. The previous studies have shown that the use of the advanced oxidation procedures (AOP) can lead to a more efficient degradation of various biologically active compounds, which are active pharmaceutical ingredients of applied drugs. The aim of this paper is the application of the plasma technology on the degradation of a two active pharmaceutical ingredients (APIs, diazepam and alprazolam) and the finished products (Bensedin((R)) and Ksalol((R))) using the dielectric barrier discharge (DBD) reactor for AOP. We studied the degradation rate of these pharmaceuticals, depending on the number of passes through the reactor. This degradation method was efficient 61 % for diazepam and 95 % alprazolam. We also examined the influence of the pH adjustment between the passes of APIs through the DBD reactor. The degradation rate of APIs and the finished products was monitored by the high performance liquid chromatography (HPLC) technique, using a photodiode array detector. The concentration of the dissolved ozone was determined using the iodometric procedure

Immobilisation d'hydrogel redox pour la détection par électrochimiluminescence

Ce travail de thèse a pour objectif l étude de l électrochimiluminescence (ECL) et son application pour le développement de nouvelles techniques analytiques. De par son importante sensibilité, l ECL est une technique performante pour des applications telles que les diagnostics cliniques ou la chimie environnementale (présence d agents contaminants dans l eau ou la nourriture). L immobilisation du luminophore ECL est réalisée généralement sur une phase solide. Cette étape constitue une phase essentielle pour obtenir une méthode d immobilisation rapide, simple, flexible et efficace de ces luminophores ECL, tout en permettant une utilisation pour des systèmes variés. La première partie de ce travail présente l optimisation de la déposition électrochimique de films de métallopolymère de ruthénium et son application pour la détection enzymatique. Un film d'épaisseur micrométrique de cet hydrogel redox a été préparé par voltamétrie cyclique. Cet hydrogel immobilisé a permis la détection d un substrat modèle (le glucose) en utilisant l'enzyme glucose déshydrogénase. La seconde partie se concentre sur le développement d une nouvelle méthode de photodéposition d un polymère. Celle-ci permet l immobilisation de centres actifs sur des régions sélectives. En utilisant les techniques de photolithographie, les figures du masque sont projetées sur la surface des électrodes. Cela permet la réalisation de spots micrométriques dont la taille, forme et épaisseur sont modulables. Les propriétés électrochimiques des films nanométriques obtenus sont comparables à ceux obtenues par électrodéposition. De même, les spectres ECL réalisés avec polymères immobilisés par ces deux stratégies sont identiques. Ces résultats montrent que les états excités induits lors de l ECL sont identiques avec les deux techniques d immobilisation. Le développement d'un tel procédé constitue une alternative prometteus pour la réalisation de réseaux de spots ECL différenciés et permettant la détection multipléxée par imagerie ECL. Dans la troisième partie de ce travail, nous avons associé la spectroélectrochimie et l'imagerie ECL pour contribuer à l étude des mécanismes ECL au niveau d'une bille micrométrique fonctionnalisée par des complexes de ruthénium. En combinant microscopie de fluorescence et imagerie ECL, la distribution des sites électroactifs et des sites ECL a pu être mise en évidence. A partir de cette étude, nous pouvons clarifier les mécanismes conduisant à l'émission ECL au niveau de ces billes fonctionnalisées.The main goal of this thesis was to study electrogenerated chemiluminescence (ECL) and its application in development of new analytical techniques. Due to its high sensitivity, ECL presents a powerful method for applications in clinical diagnostic and environmental chemistry (presence of contaminants in water or food). The immobilisation of an ECL luminophore is usually performed on a solid phase. This step is an essential point to obtain a technique for fast, simple, flexible and effective immobilisation of ECL luminophores with possibility of applications in various configurations. The first part of this work presents the optimisation of the electrochemical deposition of a ruthenium metallopolymer and its application in enzymatic detection. A redox hydrogel film with micrometric thickness was prepared using cyclic voltammetry. This immobilised hydrogel allows the detection of model substrate (glucose) using enzyme glucose dehydrogenase. The second part of this thesis is focused on the development of a new photodeposition method for the ECL polymer immobilisation. This method allows region-selective immobilisation of active centres. Using photolithographic methods, the figures from the mask are projected on the electrode surface. This allows the formation of micrometric spots which size, shape and thickness is modulated. Electrochemical properties of obtained nanometric films are comparable with those of electrodeposited films. Also, ECL spectra recorded with both immobilisation strategies are identical. It shows that the ECL excited state is the same. The obtained photopatterns were imaged using ECL. The development of such process presents an alternative for realisation of different ECL spot arrays and allows multiplexed detection by ECL imaging. In the third part of this work we have associated spectroelectrochemistry and ECL imaging to study the ECL mechanisms at the level of a single microbead, functionalised with ruthenium complex. Combining fluorescence microscopy and ECL imaging, the distribution of electroactive and ECL sites have been highlighted. From this study we can clarify the mechanism that leads to ECL emission at the level of functionalised beads.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Photopatterning of ultrathin electrochemiluminescent redox hydrogel films

Photoinitiated polymerisation is efficiently and rapidly carried out to immobilise ultrathin electrochemiluminescent redox hydrogel films. Microscale patterns are fabricated on an electrode surface by a simple photolithographic procedure and revealed by ECL imaging

The isolation, analytical characterization by HPLC-UV and NMR spectroscopy, cytotoxic and antioxidant activities of baeomycesic acid from Thamnolia vermicularis var. subuliformis

The aim of this work was the analytical characterization of the β-orcinol depside, baeomycesic acid in lichens extracts. The extract of Thamnolia vermicularis var. subuliformis was analyzed by two different methods, namely HPLC-UV and 1H-NMR analysis. The results showed that baeomycesic acid was the most abundant depside in the lichens. These results could be of use for rapid identification of this metabolite in other lichen species. Besides baeomycesic acid, three depsides and one monocyclic phenolic compound were isolated from the lichen extract on the chromatographic column. The structure of baeomycesic acid was confirmed by HPLC-UV and spectroscopic methods. In addition, antioxidant and cytotoxic activities of baeomycesic acid were determined. The result of the testing showed that baeomycesic acid exhibited a moderate radical scavenging activity (IC50 = = 602.10±0.54 μg/mL) and good cytotoxic activity. This is the first report of detailed analytical characterization and isolation, as well as antioxidant and cytotoxic activities of baeomycesic acid from Thamnolia vermicularis. These results may be helpful in future industrial production of herbal medicines that include this important natural product

Microscopic imaging and tuning of electrogenerated chemiluminescence with boron-doped diamond nanoelectrode arrays

Nanoelectrode arrays (NEAs) are increasingly applied for a variety of electroanalytical applications; however, very few studies dealt with the use of NEAs as an electrochemical generator of electrogenerated chemiluminescence (ECL). In the present study, arrays of nanodisc and nanoband electrodes with different dimensions and inter-electrode distances were fabricated by e-beam lithography on a polycarbonate layer deposited on boron-doped diamond (BDD) substrates. In particular, NEAs with 16 different geometries were fabricated on the same BDD sample substrate obtaining a multiple nanoelectrode and ultramicroelectrode array platform (MNEAP). After electrochemical and morphological characterization, the MNEAP was used to capture simultaneously with a single image the characteristic behaviour of ECL emission from all the 16 arrays. Experiments were performed using Ru(bpy)3 2+ as the ECL luminophore and tri-n-propylamine (TPrA) as the co-reactant. With a relatively limited number of experiments, such an imaging procedure allowed to study the role that geometrical and mechanistic parameters play on ECL generation at NEAs. In particular, at high concentrations of TPrA, well-separated individual ECL spots or bands revealed an ECL signal which forms a pattern matching the nanofabricated structure. The analysis of the imaging data indicated that the thickness of the ECL-emitting zone at each nanoelectrode scales inversely with the co-reactant concentration, while significantly stronger ECL signals were detected for NEAs operating under overlap conditions