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Wyniki wyszukiwania dla: AROMATIC POLYENE MACROLIDES
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Chemical and biological stability of polyene macrolides
PublikacjaThe polyene macrolide antibiotics have been used in an-tifungal therapy since first o f them were discovered in 1950's. Up to now, four polyene macrolides are being used in medical practice, namely amphotericin B, nystatin, candi-cidin and pimaricin.The antifungal activity and mode of ac-tion of polyene macrolides is determined by their structure, chemical and physical properties.The main fragment of polyene...
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Heptaene macrolides biosynthesis by Streptomyces species
PublikacjaPolyene macrolides are one of the groups of secondary metabolites, generated by microorganisms belonging to the Streptomyces genus. These compounds, containing 3 - 7 conjugated double bonds systems in their molecules exhibit high antifungal activity against a broad spectrum of fungal pathogens with heptaenes demonstrating the highest antifungal potential. At the large extent, efficiency of biosynthesis of these natural products...
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Antibiotic-sterol interactions provide insight into the selectivity of natural aromatic analogues of amphotericin B and their photoisomers
PublikacjaAromatic heptaene macrolides (AHMs) belong to the group of polyene macrolide antifungal antibiotics. Members of this group were the first to be used in the treatment of systemic fungal infections. Amphotericin B (AmB), a non-aromatic representative of heptaene macrolides, is of significant clinical importance in the treatment of internal mycoses. It includes the all-trans heptaene chromophore, whereas the native AHMs contain two...
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Analytical studies on ascosin, candicidin and levorin multicomponent antifungal antibiotic complexes. The stereostructure of ascosin A2
PublikacjaIn the class of polyene macrolides, there is a subgroup of aromatic heptaenes, which exhibit the highest antifungal activity within this type of antibiotics. Yet, due to their complex nature, aromatic heptaenes were not extensively studied and their potential as drugs is currently underexploited. Moreover, there are many inconsistencies in the literature regarding the composition and the structures of the individual components...
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Light-Induced Transformation of the Aromatic Heptaene Antifungal Antibiotic Candicidin D into Its All-Trans Isomer
PublikacjaIllumination of the aromatic heptaene macrolide antifungal antibiotic candicicin D with UV light results in an isomerization of the molecule. The product formed after irradiation of the candicidin complex with UV light (λ=365nm), namely, iso-candicidin D, was isolated and subjected to 2D NMR studies, consisting of DQF-COSY, ROESY, TOCSY, HSQC, and HMBC experiments. The obtained spectral data unambiguously evidenced that iso-candicidin...
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Quest for the Molecular Basis of Improved Selective Toxicity of All-Trans Isomers of Aromatic Heptaene Macrolide Antifungal Antibiotics
PublikacjaThree aromatic heptaene macrolide antifungal antibiotics, Candicidin D, Partricin A (Gedamycin) and Partricin B (Vacidin) were subjected to controlled cis-trans to all trans photochemical isomerization. The obtained all-trans isomers demonstrated substantially improved in vitro selective toxicity in the Candida albicans cells: human erythrocytes model. This effect was mainly due to the diminished hemotoxicity. The molecular modeling...
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Does the chemical modification of Nystatin A1 affect the drug's ability to overcome the multidrug resistance of fungi?
PublikacjaAlthough the contemporary medicine keeps moving forward, disseminated infections caused by fungal pathogens are an emerging challenge. The dramatic rise of fungal diseases, especially the most life-threatening systemic mycoses is associated with a permanently growing number of immunodeficient patients. Undoubted difficulties in the treatment of fungal infections are caused by lack of highly effective and selective antifungal drugs,...
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Molecular Umbrellas Modulate the Selective Toxicity of Polyene Macrolide Antifungals
PublikacjaAntifungal polyene macrolide antibiotics Amphotericin B (AmB) and Nystatin (NYS) were conjugated through the ω-amino acid linkers with diwalled “molecular umbrellas” composed of spermidine-linked deoxycholic or cholic acids. The presence of “umbrella” substituents modulated biological properties of the antibiotics, especially their selective toxicity. Some of the AmB-umbrella conjugates demonstrated antifungal in vitro activity...
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Versatility of putative aromatic aminotransferases from Candida albicans.
PublikacjaAmino acids constitute the key sources of nitrogen for growth of Candida albicans. In order to survive inside the host in different and rapidly changing environments, this fungus must be able to adapt via its expression of genes for amino acid metabolism. We analysed the ARO8, ARO9, YER152C, and BNA3 genes with regards to their role in the nutritional flexibility of C. albicans. CaAro8p is undoubtedly the most versatile enzyme...
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Chalcogen bonding interactions in a series of aromatic selenocyanates
PublikacjaSelenium atoms in aromatic selenocyanates are characterized by the occurrence of two σ-holes, a stronger one in the prolongation of the NC–Se bond and a weaker one in the prolongation of the Ar–Se bond. The crystal structures of several bis(selenocyanato) derivatives, prepared by a method originally developed for ortho bis-substituted derivatives, illustrate very well this difference, with a short NC–Se⋯NC ChB interaction organizing...
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Propensity of salicylamide and ethenzamide cocrystallization with aromatic carboxylic acids
PublikacjaThe cocrystallization of salicylamide (2-hydroxybenzamide, SMD) and ethenzamide (2-ethoxybenzamide, EMD) with aromatic carboxylic acids was examined both experimentally and theoretically. The supramolecular synthesis taking advantage of the droplet evaporative crystallization (DEC) technique was combined with powder diffraction and vibrational spectroscopy as the analytical tools. This led to identification of eleven new cocrystals...
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Modulation of polyene antibiotics self-association by ions from the hofmeister series
PublikacjaZbadano wpływ soli z serii hofmeistera na zjawisko samoasocjacji antybiotyku polienowego amfoterycyny B i jego pochodnych. Wykazano, że sole te zmieniając właściwości wody, wpływają istotnie na strukturę roztworów tych antybiotyków. Sole kosmotropowe zmniejszają rozpuszczalność związków, chaotropowe dają efekt przeciwny. Informacja ta jest istotna dla zrozumienia natury toksyczności amfoterycyny B i jej pochodnych.
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Molecular modelling of membrane activity of amphotericin B, a polyene macrolide antifungal antibiotic
PublikacjaPraca dotyczy różnego typu modelowań molekularnych cząsteczki przeciwgrzybowego antybiotyku (amfoterycyny B). Praca przeglądowa obejmuje opis badań nad właściwościami molekularnymi samej cząsteczki antybiotyku, jej oddziaływań z powierzchnią błony oraz struktur kanałowych jakie tworzą cząsteczki amfoterycyny wewnątrz błony lipidowej.
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Identification of aromatic compounds in odours mixture by gas chromatography and field olfactometry techniques
PublikacjaThis paper shows the results of investigation on identification aromatic compounds present in odorous mixture in atmospheric air samples collected in a vicinity of the oil refinery LOTOS S.A., located in Gdansk, during March and April period have be presented. The studies were conducted by the use of comprehensive two-dimensional gas chromatograph equipped with a cryogenic modulator and coupled with a time-of-flight mass spectrometer,...
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Application of BDD thin film electrode for electrochemical decomposition of heterogeneous aromatic compounds
PublikacjaThe aim of the presented study is to investigate the applicability of electrochemical oxidation of aromatic compounds containing heteroatoms, e.g. waste from production of pesticides or pharmaceutics, at a borondoped diamond (BDD) electrode. The BDD electrodes were synthesized by microwave plasma enhanced chemical vapour deposition (MW PE CVD). Investigation of the electrode surface by optical microscopy and scanning electron microscopy...
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Bio-based semi-aromatic polyesters for coating applications
PublikacjaLinear and branched bio-based semi-aromatic (co)polyesters were evaluated as resins for solvent-basedand powder coatings. Dimethyl-2,5-furandicarboxylate (DMF), 2,3-butanediol and various multifunc-tional comonomers were used to synthesize amorphous hydroxyl-end-capped (co)polyesters. The resinswere cross-linked using the -caprolactam blocked trimer of isophorone diisocyanate. Both the solvent-based and powder coatings proved to...
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Advanced oxidation processes for the removal of mono and polycyclic aromatic hydrocarbons – A review
PublikacjaAromatic hydrocarbons (AHs) are toxic environmental contaminants presented in most of the environmental matrices. Advanced oxidation processes (AOPs) for the removal of AHs in the account of complete mineralization from various environmental matrices have been reviewed in this paper. An in-depth discussion on various AOPs for mono (BTEX) and polyaromatic hydrocarbons (PAHs) and their derivatives is presented. Most of the AOPs were...
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The occurrence of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the chosen area of Svalbard
PublikacjaIn the recent years, scientists have been paying more attention to the impact of compounds of anthropogenic origin on the environment. Polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) are both groups of stable organic compounds, difficult to biodegrade, and potentially toxic. Because of their affinity to lipids, they can accumulate in fat tissue and exert influence on animal health. This paper present...
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Arctic as a reservoir for polycyclic aromatic hydrocarbons and polychlorinated biphenyls- water samples from Foxfonna glacier
PublikacjaPolycyclic aromatic hydrocarbons and polychlorinated biphenyls are groups of stable compounds, hard to biodegrade, potentially toxic. Their presence in Arctic environment may have a big impact on natural balance, fauna and flora. Although Arctic areas should be unpolluted, some amounts of pollutants are transferred from lower latitudes with sea currents and air masses. This paper presents the amounts of selected persistent organic...
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Contamination of Runoff Water at Gdańsk Airport (Poland) by Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs)
PublikacjaAirport runoff can contain high concentrations of various pollutants, in particular polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), the environmental levels of which have to be monitored. Airport runoff water samples, collected at the Gdańsk-Rębiechowo Airport from 2008 to 2009, were analysed for PAHs and PCBs by gas chromatography. The aromatic fractions were separated by liquid-liquid extraction...
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Monosubstituted hydrazone β-cyclodextrin derivatives for pH-sensitive complex formation with aromatic drugs
PublikacjaA new and convenient synthetic pathway was developed to produce monosubstituted cyclodextrins with high yields. Each of the β-cyclodextrin derivatives described in this work has an aromatic substituent connected with cyclodextrin core by a pH-sensitive hydrazone linker and a carbon chain. Carbon chains differ in lengths having one or three carbon atoms. The correlation between water solubility and linker length was determined using...
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Differences between selected volatile aromatic compound concentrations in sludge samples in various steps of wastewater treatment plant operations
PublikacjaSewage sludge, one of the main wastes generated during wastewater treatment, constitutes an important source of emissions of volatile chemical compounds such as volatile aromatic compounds These substances may undergo various changes as a result of operations and unit processes, which affects their concentrations in sewage sludge. An important factor determining the potential hazardousness of volatile organic compounds is the quality...
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Method for the simultaneous determination of monoaromatic and polycyclic aromatic hydrocarbons in industrial effluents using dispersive liquid-liquid microextraction with GC-MS
PublikacjaWe present a new method for simultaneous determination of 22 monoaromatic and polycyclic aromatic hydrocarbons in postoxidative effluents from the production of petroleum bitumen using dispersive liquid-liquid microextraction coupled to gas chromatography and mass spectrometry. The eight extraction parameters including the type and volume of extraction and disperser solvent, pH, salting out effect, extraction and centrifugation...
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Polychlorinated Biphenyls (PCBs) and Polycyclic Aromatic Hydrocarbons (PAHs): Sediments and Water Analysis
PublikacjaUnfavorable side effects of different forms of anthropogenic activities can be found anywhere in the world. One of the basic characteristics of pollutants entering marine and ocean waters is their spread and movement in the global ocean. A portion of the substances entering the marine environment is rapidly degraded by chemical processes occurring in the air, sediments, and water, thereby losing their toxic properties. The biggest...
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Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives
PublikacjaIt is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest–CD interactions, rendering structure-based prediction of the complexation efficiency with...
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Key-Marker Volatile Compounds in Aromatic Rice (Oryza sativa) Grains: An HS-SPME Extraction Method Combined with GC×GC-TOFMS
PublikacjaThe aroma of rice essentially contributes to the quality of rice grains. For some varieties, their aroma properties really drive consumer preferences. In this paper, using a dynamic headspace solid-phase microextraction (HS-SPME) system coupled to a two-dimensional gas chromatography (GC×GC) using a time-of-flight mass spectrometric detector (TOFMS) and multivariate analysis, the volatile compounds of aromatic and non-aromatic...
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Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen
PublikacjaThis paper describes a novel method of samplepreparation for the determination of trace concentrations ofpolycyclic aromatic hydrocarbons (PAHs) in high-boilingpetroleum products. Limits of quantitation of the investigatedPAHs in materials of this type range from tens ofnanograms per kilogram to <20 μg/kg. The studies revealedthat in order to separate most of interferences from theanalytes without a significant loss of PAHs, it...
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Effect of the ionic liquids on extraction of aromatic and sulfur compounds from the model petrochemical stream
PublikacjaSuitability of a imidazolium ionic liquids (ILs) as solvents in dearomatization and desulfurization in the ternary systems and in a model multicomponent systems has been analyzed. With this aim, ternary liquid-liquid phase equilibrium data (LLE) have been obtained for ternary mixtures of {IL + benzene, or toluene, or thiophene, or 2-butanethiol + hexane}, or {IL + benzene + 2-methylpentane} at T = 298.15 K and ambient pressure,...
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Aromagrams - aromatic profiles in the appreciation of food quality
PublikacjaW ostatnich latach obserwuje się coraz powszechniejsze stosowanie analizy instrumentalnej do oceny jakości organoleptycznej produktów spożywczych. Nowe podejście polega na tworzeniu profili zapachowych, swego rodzaju "aromagramów" charakterystycznych dla danego produktu. Do najczęściej stosowanych technik pozwalających na tworzenie i rozpoznawanie "aromagramów" należą techniki chromatograficzne, w szczególności chromatografia gazowa...
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Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
PublikacjaThe paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons...
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Morphology and local chain structure of polyamide 6 modified in the solid state with a semi-aromatic nylon salt
PublikacjaStructural and conformational differences between the polyamide 6 (PA6) homopolymer and two copolymers of PA6 modified in the solid state with 20 and 30 wt% of the semi-aromatic nylon salt of 1,5-diamino-2-methylpentane (Dytek A) and isophthalic acid (IPA) in the feed were investigated. Room temperature wide-angle X-ray diffraction (WAXD) analysis together with 13C{1H} cross-polarization/magic-angle spinning solid-state (CP/MAS)...
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Antimycobacterial activity of 5-arylidene aromatic derivatives of hydantoin
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Polycyclic aromatic hydrocarbons in smoked fish - a critical review
PublikacjaDym wędzarniczy zawiera wśród setek składników co najmniej 100 wielopierścieniowych węglowodorów aromatycznych (WWA). Benzo{a}piren (BaP) jest uważany za wskaźnikowy, rakotwórczy WWA w wędzonych rybach. Współczesne procedury analityczne obejmujące ekstrakcję węglowodorów z matrycy, oczyszczenie, rozdzielenie metodą GC lub HPLC przy użyciu, odpowiednio, detektora MS albo FLD, umożliwiają oznaczenie indywidualnych WWA w wędzonych...
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Studies of the aromatic β-diketones as extractant of copper ions
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Polycyclic aromatic hydrocarbons as test probes to investigate the retention behavior of 1,3-alternate calix[4]arene silica-bonded stationary phases
PublikacjaA series of polycyclic aromatic hydrocarbons (PAHs) of different size and shape has been used to characterize the chromatographic behavior of five calix[4]arene stationary phases in 1,3-alternate conformation synthesized in our laboratory. The selection of linear, fourring nonlinear, and five-ring PAHs gave data on selectivity changes across range of the calix[4]arene columns. Retention of the 12 aromatic solutes has been evaluated...
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Effect of Aromatic System Expansion on Crystal Structures of 1,2,5-Thia- and 1,2,5-Selenadiazoles and Their Quaternary Salts: Synthesis, Structure, and Spectroscopic Properties
PublikacjaRational manipulation of secondary bonding interactions is a crucial factor in the construction of new chalcogenadiazole-based materials. This article reports detailed experimental studies on phenanthro[9,10-c][1,2,5]chalcogenadiazolium and 2,1,3-benzochalcogenadiazolium salts and their precursors. The compounds were synthesized, characterized employing NMR and UV-Vis spectroscopy. TD-DFT calculations were also performed. The influence...
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Photoelectrochemical and thermal characterization of aromatic hydrocarbons substituted with a dicyanovinyl unit
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The presence of polycyclic aromatic hydrocarbons in disposable baby diapers: A facile determination method via salting-out assisted liquid-liquid extraction coupled with gas chromatography-mass spectrometry
PublikacjaIn this paper we demonstrate the development of the extraction procedure of polycyclic aromatic hy- drocarbons from baby diapers along with their quantification by gas chromatography-mass spectrometry. Apart from covering plastic foil, disposable baby diapers contain sorbents intended to absorb urine and feces. A hygroscopic, adsorptive, and tough-to-homogenize fibrous sorbent, represents an analytical chal- lenge to analytical...
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Antimicrobial activity of 5-arylidene aromatic derivatives of hydantoin. Part 2
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Metallochromic crown ether analogs bearing aromatic residues and azo groupings
PublikacjaPraca zawiera przegląd syntezowanych, różnych chromogenicznych związków koronowych, zawierających oprócz dwóch grup azowych i łańcucha polieterowego fragmenty heterocykliczne. Porównano właściwości otrzymanych związków w zależności od obecności heteroatomów w pierścieniu makrocyklicznym oraz różnego podstawienia cząsteczki heterocykliczej.
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The Effect of Aromatic Diimide Side Groups on the π-Conjugated Polymer Properties
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Aromatic heptaene antibiotics as an alternative for synthetic triazole fungicides in plant protection
PublikacjaAn in vitro antifungal activity of candicidin and ascosin antibiotics (0,01-10 μg/mL) towards representative strains of phytopathogenic fungi was detd. Both compds. exhibited similar half max. effective concns. inhibiting growth of the fungi as that of tebuconazole used for comparison.
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Surface and Trapping Energies as Predictors for the Photocatalytic Degradation of Aromatic Organic Pollutants
PublikacjaIn this study, anatase samples enclosed by the majority of three different crystal facets {0 0 1}, {1 0 0}, and {1 0 1} were successfully synthesized. These materials were further studied toward photocatalytic degradation of phenol and toluene as model organic pollutants in water and gas phases. The obtained results were analyzed concerning their surface structure, reaction type, and surface development. Moreover, the regression...
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The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites
PublikacjaIn this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency...
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A hierarchical porous composite magnetic sorbent of reduced graphene oxide embedded in polyvinyl alcohol cryogel for solvent‐assisted‐solid phase extraction of polycyclic aromatic hydrocarbons
PublikacjaA hierarchical porouscomposite magnetic sorbent was fabricated and applied tothe dispersive solvent-assisted solid-phase extraction of five polycyclic aromatichydrocarbons. A sorbent was first prepared by incorporating graphene oxide,calcium carbonate, and magnetite nanoparticles into a polyvinyl alcohol cryo-gel. The graphene oxide was converted to reduced graphene oxide using ascorbicacid and a hierarchical porous structure was...
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Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea
PublikacjaThe possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first...
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The effects of exogenous application of melatonin on the degradation of polycyclic aromatic hydrocarbons in the rhizosphere of Festuca
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Anion binding by p-aminoazobenzene-derived aromatic amides: spectroscopic and electrochemical studies
PublikacjaThe synthesis and complexing properties of p-aminoazobenzene-derived mono-, bis-, and trisamides were described. Ligands 3 and 4 bind anions, including fluorides, chlorides, bromides, acetates, benzoates, dihydrogen phosphates, hydrogen sulfates, and p-toluenesulfonates, in chloroform forming 1 : 1 complexes. The highest value of stability constant was evaluated for the 4-F− complex (log K = 5.63 ± 0.21). On the basis of 1H NMR,...
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Activated biochars reduce the exposure of polycyclic aromatic hydrocarbons in industrially contaminated soils
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Aromatic Dendrimers Bearing 2,4,6-Triphenyl-1,3,5-triazine Cores and Their Photocatalytic Performance
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