Osnovni cilj doktorske disertacije je istraţivanje mogućnosti primene novog anodnog materijala na bazi nanokompozita PbO2-GNR (olovo dioksid-grafen nanotraĉice) za dekontaminaciju otpadnih voda ...zagaĊenih fenolnim jedinjenjima tehnikom elektrohemijske oksidacije (anodne oksidacije-AO). Ispitivanja su izvedena praćenjem procesa simultane AO kompleksne smeše fenola i njegovih metilovanih i hlorovanih derivata u 0,1 M elektrolitu Na2SO4. Nanokompozit PbO2-GNR je dobijen tehnikom mešanja GNR sa nanoĉesticama PbO2 koje su sintetisane hidrotermalnim postupkom. Kristalna struktura, morfologija i sastav sintetisanog materijala su odreĊeni tehnikama rendgenske difraktometrije praha (XRPD), skenirajuće i transmisione elektronske mikroskopije i energetski disperzivne rendgenske spektroskopije (FESEM-EDS i TEM-EDS). FESEM slike su potvrdile prisustvo nanoĉestica PbO2 na GNR. Merenja cikliĉne voltametrije na PbO2-GNR elektrodi u 0,1 M elektrolitu Na2SO4 opterećenog fenolom ukazala su, da se elektrohemijska oksidacija fenola odvija putem indirektnog mehanizma posredstvom hidroksil radikala. Anodna oksidacija fenolnih jedinjenja izvršena je u potenciostatskom reţimu na potencijalima 2,3 V i 3 V. Efikasnost uklanjanja fenolnih jedinjenja povećava se sa povećanjem vremena elektrolize i primenjenog potencijala (do 78 % tokom 60 minuta na potencijalu od 3 V). GC-MS hromatografska analiza potvrĊuje da nakon sukcesivnih procesa dehlorovanja i dimetilacije fenolnih jedinjenja dolazi do razgradnje aromatiĉnog prstena tj. nastaju intermedijerne vrste koje se dalje razlaţu na ugljen dioksid i vodu. Novi sintetisani anodni materijal PbO2-GNR moţe se uspešno primeniti u preĉišćavanju otpadnih voda kontaminiranih sloţenim smešama fenolnih jedinjenja (complex mixtures of phenolic compounds) postupkom anodne oksidacije.
Otpadne vode s karboksimetil-celulozom (CMC) obično imaju visoku kemijsku potrebu za kisikom (COD) i salinitet (> 10 %). Prije primjene biokemijskih metoda važno je otpadne vode pročistiti radi ...smanjenja saliniteta i oporabe vrijednih spojeva. U ovom je radu otpadna voda s CMC-om predobrađena destilacijom i ekstrakcijom. Iz otpadne vode izvučeni su vrijedni kemijski spojevi uključujući etoksioctenu kiselinu i NaCl. Analize metodama GC-MS i NMR pokazuju da čistoća etoksioctene kiseline raste s povećanjem početnog pH otpadne vode. Primijenjen je anaerobno-aerobni postupak za pročišćavanje destilata (reaktor s lebdećim muljem i kontaktna oksidacija), koji je pokazao dobru otpornost na udarna opterećenja. Nakon 45-dnevnog kontinuiranog rada CODCr se može održati ispod 500 mg l−1 što je u skladu sa šangajskim standardima za ispuštanje industrijskih otpadnih voda.
Cilj: Plinska kromatografija s masenom spektrometrijom (GC-MS) osjetljiva je i selektivna metoda s potencijalom za standardno određivanje rokuronijeva bromida u plazmi. Primjenom u postupcima ...izvantjelesne membranske oksigenacije (engl. Extracorporeal Membrane Oxygenation; ECMO) možemo utvrditi utjecaj na koncentracije lijekova. Ciljevi rada bili su ispitati primjerenost GC-MS metode za određivanje rokuronijeva bromida u plazmi te usporediti njegove venske i arterijske koncentracije kod pacijenata s ECMO potporom. Materijali i metode: Korištene su standardne otopine različitih omjera, plazma te otopina rokuronijeva bromida (Esmeron, 10 mg/ml, N. V. Organon, Nizozemska), etanol, diklormetan, natrijev dihidrogenfosfat, kalijev jodid, voda, aceton. GC-MS metoda provedena je u Nastavnom zavodu za javno zdravstvo PGŽ-a, a klinički dio na pet slučajno odabranih pacijenata liječenih ECMO potporom u KBC-u Rijeka. Rezultati: Dobiveni su validacijom: GD 0,553 μg/ml, GK (potvrđen) 5 μg/ml, preciznost RSD = 2,083 % (RSD ≤ 10 %), intermedijarna preciznost RSD = 3,05 % (RSD ≤ 10 % ), točnost 98,9 % (90 – 110 %), koeficijent korelacije r = 0,9961 (r ≥ 0,995), selektivnost metode – RT = 23,25 min, m/z = 413. Klinička vrijednost metode potvrđena je mjerenjem koncentracija rokuronijeva bromida kod pacijenata s ECMO potporom. Sve vrijednosti bile su više u venskom nego u arterijskom uzorku u svim mjerenjima. Zaključci: Validacijom GC-MS metode potvrđeno je kako se validacijski parametri nalaze u kriteriju prihvatljivosti te je metoda primjenjiva za određivanje rokuronijeva bromida u plazmi. ECMO potpora smanjuje razinu lijeka u arterijskom uzorku, ali zbog malog broja uzoraka i velike varijabilnosti u koncentraciji nije postignuta statistički značajna razlika.
Objective: Gas chromatography with mass spectrometry (GC-MS) is a sensitive and selective method with the potential for standard determination of rocuronium bromide in plasma. The use of Extracorporeal Membrane Oxygenation (ECMO) can be used to determine the effect on drug concentrations. The aim of the study was to examine the suitability of the GC-MS method for the determination of rocuronium bromide in plasma and to compare its venous and arterial concentrations in patients with ECMO support. Materials and methods: Standard solutions of different ratios, plasma and rocuronium bromide solution (Esmeron, 10 mg/ml, N.V. Organon, The Netherlands), ethanol, dichloromethane, sodium dihydrogen phosphate, potassium iodide, water, acetone were used. GC-MS was performed in the Teaching Institute for Public Health Rijeka, and the clinical part on five randomly selected patients treated with ECMO support in University hospital of Rijeka. Results: obtained by validation are: GD 0.553 μg/ml, GK (confirmed) 5 μg/ml, accuracy RSD = 2.083% (RSD ≤ 10%), intermediate accuracy RSD = 3.05% (RSD ≤ 10%), accuracy 98.9% (90 – 110%), correlation coefficient k = 0.9961 (r ≥ 0.995), selectivity of the method – RT = 23.25 min, m/z = 413. The clinical value of the method was confirmed by measuring the concentrations of rocuronium bromide in patients with ECMO support. Rocuronium bromide values were higher in the venous than in the arterial sample in all measurements. Conclusions: Validation of the GC-MS method confirmed that all performed validation parameters are in the acceptance criterion and the method is applicable for the determination of rocuronium bromide. ECMO support reduces the drug level in the arterial sample, but due to the small number of samples and high variability in concentration, no statistically significant difference was achieved.
The multicoloured ‘Košna’ conglomerates are investigated in the area of the Košna Voda spring, in the Brušane area of Velebit Mt., Croatia. The studied conglomerates consist of red-coloured matrix ...and clasts of various lithologies (sandstones, limestones, chert and quartz pebbles) and sizes, suggesting provenance from different areas. Average clast size and their percentage was determined by the Udden-Wentworth classification with estimation of the matrix content. Clasts and matrix lithological and mineralogical characteristics were determined using petrographic, ore microscopy, and X-ray diffraction analysis. Sandstone clasts in the studied conglomerates are classified as lithic arenites, subarkoses and arkoses. Limestone clasts are mostly wackestones to packstones with foraminifera, ostracods, echinoid and bryozoan fragments that derive from late Carboniferous/early Permian shallow-marine limestones. Calcispheres and incipient growth forms of Microcodium are also present, suggesting different sediment sources and resedimentation processes. Fragments of fusulinid foraminifera were identified in the matrix of the ‘Košna’ conglomerates. Based on the analyses performed, and field observations, the ‘Košna’ conglomerates are described as early Permian (Cisuralian) polymictic clast-supported to matrix-supported conglomerates and breccia-conglomerates that share structural and textural similarities with conglomerates from other areas in the Dinarides, as well as in the Eastern and Southern Alps. The ‘Košna’ conglomerates are younger than the Sakmarian and are comparable with the Trogkofel limestones of the Carnic Alps and the Karavanke Mts. in Slovenia. We suggest that the studied deposits originated from the uplifted Variscan Mountains during the Variscan and Saalian orogenic movements, and were finally deposited from tractive flows and occasional debris flows in a shallow marine environment of the Palaeo-Tethys, possibly in fan deltas.
Among the multitude of polymers with carbon-based macromolecular architectures that easily ignite in certain applications where short circuits may occur, polyimide has evolved as a class of polymers ...with high thermal stability while exhibiting intrinsic flame retardancy at elevated temperatures via a char-forming mechanism. However, high amounts of aromatic rings in the macromolecular backbone are required for these results, which may affect other properties such as film-forming capacity or mechanical properties; thus, much work has been done to structurally derivatize or make hybrid polyimide systems. In this respect, flexible polyimide films (PI(1–4)) containing bulky 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) units have been developed starting from commercial dianhydrides and an aromatic diamine containing two side chain bulky DOPO groups. The chemical structure of PI(1–4)) was characterized by 1H NMR, 13C NMR and 31P NMR spectroscopy. The optical properties, including absorption and luminescence spectra of these polymers, were analyzed. All polyimides containing DOPO derivatives emitted blue light with an emission maxima in the range of 340–445 nm, in solvents such as N,N-dimethylformamide, N-methyl-2-pyrrolidone, chloroform, and N,N-dimethylacetamide, while green light emission (λem = 487 nm for PI-4) was evidenced in a thin-film state. The thermal decomposition mechanism and flame-retardant behavior of the resulting materials were investigated by pyrolysis-gas-chromatography spectrometry (Py-GC), scanning electron microscopy (SEM), EDX maps and FTIR spectroscopy. The residues resulting from the TGA experiments were examined by SEM microscopy images and FTIR spectra to understand the pyrolysis mechanism.
The intention of this research was to select the ideal condition for accelerated aging of bio-oil and the consequences of additive in stabilizing the bio-oil. The bio-oil was produced from the ...catalytic pyrolysis of empty fruit bunch. The optimum reaction conditions applied to obtain the utmost bio-oil yield were 5 wt% of H-Y catalyst at reaction temperature of 500 °C and nitrogen flow rate of 100 ml/min. A 10 wt% of solvents including acetone, ethanol, and ethyl acetate were used to study the bio-oil’s stability. All the test samples were subjected to accelerated aging at temperature of 80 °C for 7 days. The properties of samples used as the indicator of aging were viscosity and water content. The effectiveness of solvents increased in the following order: acetone, ethyl acetate, and 95 vol% ethanol. Based on the result of Gas Chromatography-Mass Spectrometry (GC-MS), it could impede the chain of polymerization by converting the active units in the oligomer chain to inactive units. The solvent reacted to form low molecular weight products which resulted in lower viscosity and lessen the water content in bio-oil. Addition of 95 vol% ethanol also inhibited phase separation.
Anthropogenic microplastics (MPs) and nanoplastics (NPs) are ubiquitous pollutants found in aquatic, food, soil and air environments. Recently, drinking water for human consumption has been ...considered a significant pathway for ingestion of such plastic pollutants. Most of the analytical methods developed for detection and identification of MPs have been established for particles with sizes > 10 μm, but new analytical approaches are required to identify NPs below 1 μm. This review aims to evaluate the most recent information on the release of MPs and NPs in water sources intended for human consumption, specifically tap water and commercial bottled water. The potential effects on human health of dermal exposure, inhalation, and ingestion of these particles were examined. Emerging technologies used to remove MPs and/or NPs from drinking water sources and their advantages and limitations were also assessed. The main findings showed that the MPs with sizes > 10 μm were completely removed from drinking water treatment plants (DWTPs). The smallest NP identified using pyrolysis-gas chromatography-mass spectrometry (Pyr-GC/MS) had a diameter of 58 nm. Contamination with MPs/NPs can occur during the distribution of tap water to consumers, as well as when opening and closing screw caps of bottled water or when using recycled plastic or glass bottles for drinking water. In conclusion, this comprehensive study emphasizes the importance of a unified approach to detect MPs and NPs in drinking water, as well as raising the awareness of regulators, policymakers and the public about the impact of these pollutants, which pose a human health risk.
The distribution of the alleles and haplotypes for blood groups A1A2B0, MNSs, RHESUS, P1, KELL-CELLANO and biochemical markers of the alleles of loci AMY2, HPA, GC, C3, TF, BF, CP, PI (including ...subtypes) were studied in 125 Moldavian individuals from Karahasani settlement, Stefan- Voda District, Republic of Moldavia. The results show that the gene pool of Moldavians is similar to those of Southeastern European populations. Die Allel- bzw. Haplotyp-Frequenzen der Blutgruppen A1A2B0, MNSs, RHESUS, P1, KELL-CELLANO sowie der Serumproteine AMY2, HPA, GC, C3, TF, BF, CP, PI (einschließlich der Untergruppen) wurden an 125 Individuen aus dem Dorf Karahasani, Stefan Voda Distrikt, Moldawien, untersucht. Die Ergebnisse zeigen, dass der Genpool der moldawischen Bevölkerung dem anderer südosteuropäischer Bevölkerungen ähnlich ist.
The objective of the work was to obtain materials with aromatherapeutic and antibacterial properties by applying emulsions based on peppermint essential oil (PEO) onto cotton fabric. For this ...purpose, some emulsions based on PEO incorporated in various matrices (chitosan + gelatin + beeswax; chitosan + beeswax; gelatin + beeswax and gelatin + chitosan) were prepared. Tween 80 was used as a synthetic emulsifier. The influence of the nature of matrices and of the concentration of Tween 80 on the stability of the emulsions was evaluated by the creaming indices. The materials treated with the stable emulsions were analyzed in terms of sensory activity, of the comfort characteristics, and of the gradual release of the PEO in the artificial perspiration solution. The sum of volatile components retained by samples after exposure to air was determined by GC-MS. The results regarding antibacterial activity showed that materials treated with emulsions have a good inhibitory effect on
(diameters of the inhibition zones between 53.6 and 64.0 mm) and on
(diameters of the inhibition zones between 38.3 and 64.0 mm). Our data suggest that by applying peppermint-oil-based emulsions on a cotton support, aromatherapeutic patches, bandages and dressings with antibacterial properties can be obtained.
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