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Investigation of solid polymer electrolyte gas sensor with different electrochemical techniques
PublicationIn this work solid polymer electrolyte (SPE) amperometric sulphur dioxide sensor is investigated. Nafion was used as a membrane electrode and 1M sulphuric acid as an internal electrolyte. Sensor response to sulphur dioxide was measured. Besides traditional constant voltage amperometry also different electrochemical techniques were used. Results obtained by these methods are compared.
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Structural change of carbon supported Pt nanocatalyst subjected to a step-like potential cycling in PEM FC
PublicationIn this paper we present detailed X-ray absorption fine structure (XAFS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigations of the changes in the local geometric and electronic structure of Pt nanoparticles used as a cathode catalyst in proton exchange membrane fuel cell (PEMFC), working under controlled potential cycling conditions.
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Self-Organization of Graft Copolymers and Retortable iPP-Based Nanoporous Films Thereof
PublicationPolyolefins might become inexpensive alternatives to the existing membranes based on polyethersulfone. Here we disclose the production of retortable, well-defined PP-based nanoporous membranes derived from amphiphilic graft copolymer precursors. The graft copolymers, containing a polypropylene backbone and polyester grafts, were obtained by grafting lactones, specifically δ-valerolactone and ε-caprolactone, from well-defined randomly...
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Molecular Targets for Anticandidal Chemotherapy
PublicationA relatively small number of anticandidal chemotherapeutics used in clinical practice is at least in part consequence of a limited number of their molecular targets: ergosterol in the membrane, lanosterol demethylase, b(1!3) glucan synthase, and DNA/RNA biosynthesis. Much more potential novel targets have been revealed by the comparative genomic studies identifying essential genes unique for Candida albicans or resulted from recognition...
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The influence of dynamic load changes on temporary impedance in hydrogen fuel cells, selection and validation of the electrical equivalent circuit
PublicationTo achieve optimal performance of a fuel cell, a reliable monitoring and diagnostic method is required. The currently utilized methods give limited information or they are impossible to use under dynamic working conditions. To obtain comprehensive information about the fuel cell operation we utilized novel dynamic electrochemical impedance spectroscopy. Impedance measurements in dynamic mode were performed on a hydrogen fuel cell,...
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Optimization of a Fabric Phase Sorptive Extraction protocol for the isolation of six bisphenols from juice pouches to be analysed by high performance liquid chromatography coupled with diode array detector
PublicationFabric Phase Sorptive Extraction (FPSE) combined with high pressure liquid chromatography using to diode array detection (HPLC-DAD) was applied for the simultaneous determination of bisphenols (BPA, BPB, BPC, BPE, BPF, BPS) in juice pouches. The FPSE procedure was optimized with regards to the critical parameters that affect the performance of the method including the selection of the FPSE membrane type and size, adsorption time,...
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Badania możliwości wykorzystania cieczy jonowych w procesach oczyszczania biogazu
PublicationCelem pracy było lepsze zrozumienie mechanizmu przenikania metanu i tlenku węgla(IV) przez imidazoliowe, amoniowe oraz fosfoniowe ciecze jonowe osadzone na nośniku polimerowym, jak również opracowanie nowych procedur badawczych, przygotowania i użycia immobilizowanych membran ciekłych w procesach separacji gazów. Przeprowadzono badania przenikanie CO2 oraz CH4 przez ciecz jonowe unieruchomione w porach porowatego nośnika polimerowego...
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Chapter 4. Electricity generation from glucose microbial fuel cell
PublicationThe microbial fuel cell was constructed to generate electricity with simultaneous digestion of a glucose fuel by a bacterial biofilm. The decomposition of glucose resulted in releasing of electrons to an anode and to production of some by-products, e.g. metane or organic acids. It was found that maximum electric power density strongly depended on the proton transport through the proton exchange membrane seperating the anolyte and...
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Calix[4]arenes appended with thioamide moieties as powerful tool for heavy metals recognition
PublicationSelectivity of new thioamide derivatives was assessed using those ligands as sensor materials in ion-selective membrane electrodes and tested towards Pb2+ - selectivity. The influence of the nature of the thioamide function (linear, branched or cyclic substituents) on their ionophoric properties was investigated. Electrodes based on cyclic thioamide moieties are promising analytical tools for monitoring Pb2+ concentration in natural...
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Pharmaceutical applications of surfactants
PublicationIn this study we focused on biological activity of various surfactants. According to our research, they con act both as carriers as well as therapeutic agents. Depending on their concentration, they can create different structures in a solution, which influence their properties. Liposomes have a significant role in drug delivery system. Surfactants in from of bilayer are analogous to natural biological cell membrane.
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O-substituted tetrahydroxamate derivatives of p-tert-butylcalix[4]arene as receptors for transition and heavy metal cations
PublicationTetrasubstituted O-hydroxamate derivatives of p-tert-butylcalix[4]arene were applied as active materials in ion-selective membrane electrodes and were tested towards Pb-selectivity. The electrodes gave near-Nernstian characteristics for Pb2+ cations. The selectivity coefficients were determined. The influence of plasticizer on the electrode behaviour was studied. The dependence of the chemical structure on selectivity coefficients...
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Lipopolysaccharides: regulated biosynthesis and structural diversity
PublicationThe cell envelope of Gram-negative bacteria contains two distinct membranes, an inner (IM) and an outer (OM) membrane, separated by the periplasm, a hydrophilic compartment that includes a thin layer of peptidoglycan. The most distinguishing feature of such bacteria is the presence of an asymmetric OM with phospholipids located in the inner leaflet and lipopolysaccharides (LPSs) facing the outer leaflet. The maintenance of this...
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CHARAKTERYSTYKA WYMIANY CIEPŁA I OPORÓW PRZEPŁYWU OMYWANIA MIKROSTRUGAMI ROZWINIĘTEJ POWIERZCHNI
PublicationW artykule przedstawiono eksperymentalne badania kompaktowego wymiennika ciepła z intensyfikacją przejmowania ciepła przy użyciu mikrostrug. Niniejszy artykuł przedstawia projekt i testy prototypu, wymiennika ciepła typu mikrostrugowego. Modułowa konstrukcja wymiennika umożliwia zmianę wymiarów geometrycznych, a także zmianę materiału przegrody wymiennika ciepła. Metoda graficzna Wilsona została z zastosowana w celu określenia...
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A robust sliding mode observer for non-linear uncertain biochemical systems
PublicationA problem of state estimation for a certain class of non-linear uncertain systems has been addressed in this paper. In particular, a sliding mode observer has been derived to produce robust and stable estimates of the state variables. The stability and robustness of the proposed sliding mode observer have been investigated under parametric and unstructured uncertainty in the system dynamics. In order to ensure an unambiguous non-linear...
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Elastoplastic material law in 6-parameter nonlinear shell theory
PublicationWe develop the elastoplastic constitutive relations for nonlinear exact 6-parameter shell theory. A J2-type theory with strain hardening is formulated that takes into account asymmetric membrane strain measures. The incremental equations are solved using implicit Euler scheme with closest point projection algorithm. The presented test example shows the correctness of the proposed approach. Influence of micropolar material parameters...
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New bis(azobenzocrown)s with dodecylmethylmalonyl linkers as ionophores for sodium selective potentiometric sensors
PublicationNovel biscrowns 1 and 2 were synthesized from 13-membered azobenzocrown ethers containing bromoalkylenoxy chains in para position relative to the azo group. The synthesized diester molecules are dodecylmethylmalonic acid derivatives differing by the linker length. The synthesized compounds have the potential of being used as sodium ionophores in ion-selective electrodes. They were characterized and used as ionophores in classic...
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SIMULATION OF PROCEED® SURGICAL MESH APPLIED TO VENTRAL HERNIA REPAIR
PublicationIn the present research, Proceed® implant is considered. The system is subjected to short-time dynamic pressure load, similar to post-operative cough naturally occurring in human abdomen. The model refers to a clinical case of 5cm of hernia operated by Proceed implant fixed by 15 joints every 3cm around the orifice. The simulations of the implanted mesh are performed by means of the Finite Element Method. The implant is modelled...
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Nonlinear FEM analysis of irregular shells composed of fiber metal laminates
PublicationThe paper deals with the analysis of failure initiation in shells made of Fiber Metal Laminates (FML). The elas-tic material law for orthotropic lamina is stated accounting for asymmetric in-plane stress and strain measures. The asymmetry results from the employed general nonlinear 6-field shell theory where the generalized dis-placements involve the translation and the proper rotation field. The novelty of the presented results...
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Galerkin formulations with Greville quadrature rules for isogeometric shell analysis: Higher order elements and locking
PublicationWe propose new Greville quadrature schemes that asymptotically require only four in-plane points for Reissner-Mindlin (RM) shell elements and nine in-plane points for Kirchhoff-Love (KL) shell elements in B-spline and NURBS-based isogeometric shell analysis, independent of the polynomial degree of the elements. For polynomial degrees 5 and 6, the approach delivers high accuracy, low computational cost, and alleviates membrane and...
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Methodology Approach for Microplastics Isolation from Samples Containing Sucrose
PublicationThe growing production and use of plastics significantly contribute to microplastics (MPs) contamination in the environment. Humans are exposed to MPs primarily through the gastrointestinal route, as these particles are present in beverages and food, e.g., sugar. Effective isolation and identification of MPs from food is essential for their elimination. This study aimed to evaluate factors influencing the isolation of MPs from...
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Charakterystyka areodynamiczna membranowego przekrycia wiszącego.
PublicationArtykuł przedstawia charakterystykę aerodynamiczną membranowego przekrycia wiszącego. Prezentowane są dwie koncepcje przyjmowania wartości współczynnika aerodynamicznego. Pierwsza z koncepcji bazuje bezpośrednio na testach laboratoryjnych druga zaś wykorzystuje uproszczone podejście normowe.This paper presents the aerodynamic characteristics of membrane hanging roof. The two concepts of taking the value of the aerodynamic factor...
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Permeation and sorption properties of poly(ether-block-amide) membranesfilled by two types of zeolites
PublicationThe experimental study of transport properties of mixed matrix membranes (MMMs) based on PEBA-4033 with two types of zeolites is reported. Gas (CO2, O2, N2) and vapor (benzene, toluene, methanol, water) permeation measurements were performed using the differential flow permeameter at temperature of 298.15 K and at atmospheric pressure. Gas/vapor permeation was monitored by measuring the changes of the thermal conductivity of carrier...
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A Flexible Nafion Coated Enzyme‐free Glucose Sensor Based on Au‐dimpled Ti Structures
PublicationThe detection of glucose at low concentrations using electrochemical sensors is of great importance due to the possibility of using different human body fluids than blood, such as e.g. urine, saliva, sweat or tears. The interest behind those biofluids is related to their utility in non-invasive sugar determination. In this work, we present flexible, fully biocompatible electrode material based on Au nanoparticles immobilized onto...
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Regulated Assembly of LPS, Its Structural Alterations and Cellular Response to LPS Defects
PublicationDistinguishing feature of the outer membrane (OM) of Gram-negative bacteria is its asymmetry due to the presence of lipopolysaccharide (LPS) in the outer leaflet of the OM and phospholipids in the inner leaflet. Recent studies have revealed the existence of regulatory controls that ensure a balanced biosynthesis of LPS and phospholipids, both of which are essential for bacterial viability. LPS provides the essential permeability...
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Investigation of poly(3,4-ethylenedioxythiophene) deposition method influence on properties of ion-selective electrodes based on bis(benzo-15-crown-5) derivatives
PublicationGlassy carbon electrodes modified by conductive polymers and membrane with derivatives of bis(benzo-15-crown-5) were tested as solid contact ion selective electrodes for K+ ions concentration determination. PEDOT with PSS, Cl- and ClO4- counter ions was electrochemically deposited onto glassy carbon substrates using four different electrochemical approaches (potentiostatic, galvanostatic, potentiodynamic and potentiostatic pulses)....
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Dissection of σE‐dependent cell lysis in Escherichia coli: roles of RpoE regulators RseA, RseB and periplasmic folding catalyst PpiD
PublicationTo understand the mechanism of sigma(E)-dependent cell lysis, we examined the consequences of deletion derivatives of rpoE regulators rseA, rseB and rseC on sigma(E) transcription, on levels of free versus membrane-bound sigma(E) and on OMP-biogenesis limiting factor(s) that could impact cell lysis. RT-PCR showed that individual nonpolar DeltarseA and DeltarseB increased the rpoE expression to varying extents, with pronounced induction...
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Does the chemical modification of Nystatin A1 affect the drug's ability to overcome the multidrug resistance of fungi?
PublicationAlthough 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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Effects of dispersion on predicting longitudinal concentration profiles in activated sludge reactors
PublicationW pracy przedstawiono wpływ dyspersji na prognozowanie stężeń azotu amonowego w komorach osadu czynnego w oczyszczalni ścieków Gdańsk-Wschód. W tym celu wykorzystano jednowymiarowe równanie adwekcji-dyspersji z członem źródłowym (szybkością nitryfikacji). Współczynnik dyspersji został wyznaczony na podstawie pomiarów znacznika fluoroscencyjnego. Model został zweryfikowany w oparciu o pomiary stężeń azotu w 6 sekcjach komory tlenowej...
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Distillery Fusel Oil as an Alternative Carbon Source for Denitrification – from Laboratory Experiments to Full-Scale Applications
PublicationIndustrial waste products may be a viable alternative to commercial external carbon sources, such as ethanol. In this study, the properties of fusel oil (distillery waste product) were investigated in terms of temperature dependency of denitrification, acclimation period, and the effects on NO2-N and PO4-P behavior. Furthermore, results obtained during three different full-scale trials were used to verify similarities and differences...
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Local atomic order in low Pt-content nanocatalysts investigated in situ by XAS
PublicationThe unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis of the EXAFS signal at the Pt L3-edge indicates that upon operating the fuel...
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Electrochemical sensor for measurement of volatile organic compounds employing square wave perturbation voltage
PublicationThe paper presents the results of investigation on a prototype sensor for measurement of benzaldehyde in air. Sensitivity and limit of quantification of the sensor were determined for different internal electrolyte using the square wave voltammetry (SWV) as a detection technique. The working and counter electrodes were made of platinum. Ionic liquids 1-hexyl, 3-methylimidazolium chloride,1-hexyl, 3-methylimidazolium bis (trifluoromethanesulfonyl)...
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The Hydrolysis of Slowly Biodegradable Substrate in Activated Sludge
PublicationIn a present work a novel procedure, based on the standard batch tests and pretreatment of wastewater sample with coagulation-flocculation method, was proposed to evaluate the effects of hydrolysis of slowly biodegradable substrate (Xs) on biological nutrient removal (BNR) processes in activated sludge systems. The study was conducted at two large BNR wastewater treatment plants (WWTPs) in northern Poland: "Wschod" in Gdansk and...
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Torsional elasticity and energetics of F1-ATPase
PublicationFoF1-ATPase is a rotary motor protein synthesizing ATP from ADP driven by a cross-membrane proton gradient. The proton flow through the membrane-embedded Fo generates the rotary torque that drives the rotation of the asymmetric shaft of F1. Mechanical energy of the rotating shaft is used by the F1 catalytic subunit to synthesize ATP. It was suggested that elastic power transmission with transient storage of energy in some compliant...
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Molecular Strategy for Survival at a Critical High Temperature in Eschierichia coli
PublicationThe molecular mechanism supporting survival at a critical high temperature (CHT) in Escherichia coli was investigated. Genome-wide screening with a single-gene knockout library provided a list of genes indispensable for growth at 47°C, called thermotolerant genes. Genes for which expression was affected by exposure to CHT were identified by DNA chip analysis. Unexpectedly, the former contents did not overlap with the latter except...
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PTD4 Peptide Increases Neural Viability in an In Vitro Model of Acute Ischemic Stroke
PublicationIschemic stroke is a disturbance in cerebral blood flow caused by brain tissue ischemia and hypoxia. We optimized a multifactorial in vitro model of acute ischemic stroke using rat primary neural cultures. This model was exploited to investigate the pro-viable activity of cell-penetrating peptides: arginine-rich Tat(49–57)-NH2 (R49KKRRQRRR57-amide) and its less basic analogue, PTD4 (Y47ARAAARQARA57-amide). Our model included glucose...
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Checkpoints that regulate balanced biosynthesis of lipopolysaccharide and its essentiality in Escherichia coli
PublicationThe outer membrane (OM) of Gram-negative bacteria, such as Escherichia coli, is essential for their viability. Lipopolysaccharide (LPS) constitutes the major component of OM, providing the permeability barrier, and a tight balance exists between LPS and phospholipids amounts as both of these essential components use a common metabolic precursor. Hence, checkpoints are in place, right from the regulation of the first committed step...
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Direct injection liquid chromatography-mass spectrometry (DI-LC-MS) analysis for rapid lipidomic profiling of extracellular vesicles
PublicationExtracellular vesicles (EVs) are small, spherical particles produced by eukaryotic and prokaryotic cells, surrounded by a bilayer membrane and carrying various bioactive molecules, such as proteins, surface receptors, membrane and soluble proteins, lipids, and nucleic acids. EVs are of substantial interest because of their important roles in cell communication, epigenetic regulation and possible application in disease diagnosis...
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Badania parametrów metrologicznych amperometrycznego czujnika ditlenku siarki
PublicationW pracy porównano właściwości dwóch nowych prototypowych wersji amperometrycznego czujnika ditlenku siarki, wyposażonego w elektrody robocze wykonane w postaci warstw złota i platyny napylonych bezpośrednio na zewnętrzną powierzchnię membrany nafionowej. Elektrolitami wewnętrznymi były wodne roztwory kwasu siarkowego z dodatkiem dimetylosulfotlenku.
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Ciliated protozoa in the impact zone of the Uzhgorod treatment plant
PublicationThis paper presents the results of studies on the Uzh River (Ukraine, Zakarpattia Oblast) near the effluent point of a sewage treatment plant in Uzhgorod. The samples were taken at various sites of the treatment plant along the stages of purification process, as well as in the river, at a number of different points above and below the wastewater discharge. At each of these objects, the temperature...
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Modelling of wastewater treatment plant for monitoring and control purposes by state - space wavelet networks
PublicationMost of industrial processes are nonlinear, not stationary, and dynamical with at least few different time scales in their internal dynamics and hardly measured states. A biological wastewater treatment plant falls into this category. The paper considers modelling such processes for monitorning and control purposes by using State - Space Wavelet Neural Networks (SSWN). The modelling method is illustrated based on bioreactors of...
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Distillery Fusel Oil as an Alternative Carbon Source for Denitrification – from Laboratory Experiments to Full-Scale Applications
PublicationIndustrial waste products may be a viable alternative to commercial external carbon sources. In this study, the properties of fusel oil (distillery waste product) were investigated in terms of temperature dependency of denitrification and acclimation period. Furthermore, results obtained during three different full-scale trials were used to verify similarities and differences with the results obtained under laboratory-scale conditions....
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Iron(III)-selective materials based on a catechol-bearing amide for optical sensing
PublicationThe synthesis and ion-binding properties of a new amide L derived from 3,4-dihydroxybenzoic acid are described. Due to the presence of a catechol unit, the compound interacts selectively with iron(III) in organic solvent (dimethyl sulfoxide, DMSO) to produce a color change from pale yellow to green. The incorporation of the ligand L into polymeric matrices or its encapsulation into surfactant-based spheres enables analyte detection...
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Lower rim substituted p-tert-butyl-calix[4]arene. Part 17. synthesis, extractive and ionophoric properties of p-tert-butylcalix[4]arene appended with hydroxamix acid moieties
PublicationThe synthesis and characterization of four p-tert-butylcalix[4]arene-hydroxamic acidc are reported. The dependence of the metal ion binding, assessed by liquid extraction of the metal nitrates from water into dichloromethane in individual and competitive experiments, on the ligand structure, is presented. The results showed that those ligands could be successfully used in separation process of trnasition and heavy metals often...
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Functionalized azobenzocrown ethers as sensor materials—The synthesis and ion binding properties
PublicationNew 13- and 16-membered azobenzocrown ethers with aromatic amino, amide, ether–ester or ether–amide residue in para position to an azo moiety were obtained. Acid–base properties and ion binding ability of the colored compounds were studied by spectroscopic methods: UV–vis, fluorimetry and 1H NMR spectroscopy. Selected azobenzocrowns were tested as ionophores in ion-selective membrane electrodes (ISEs) – classic and miniature all...
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Modeling of subarachnoid space width change caused by blood circulation in brain vessels
PublicationThe subarachnoid space is an anatomic space, lying in the central nervous system, between the arachnoid membrane and the pia mater. It is filled with cerebrospinal fluid, which protects and nourishes the brain. The pathological disorder of the subarachnoid space (i.e. increase or decrease of its width) a ects the nervous system. Therefore, it is important to diagnose the width changes of the subarachnoid space. One way to support...
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Green porous benzamide-like nanomembranes for hazardous cations detection, separation, and concentration adjustment
PublicationGreen biomaterials play a crucial role in the diagnosis and treatment of diseases as well as health-related problem-solving. Typically, biocompatibility, biodegradability, and mechanical strength are requirements centered on biomaterial engineering. However, in-hospital therapeutics require an elaborated synthesis of hybrid and complex nanomaterials capable of mimicking cellular behavior. Accumulation of hazardous cations like...
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Lower rim substituted tert-butylcalix[4]arenes (Part VI). Synthesis and ionophoric properties of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(3-diethoxyphosphorylpropoxy)calix[4]arene.
PublicationSyntezowano nowy związek: 5,11,17,23-tetra-tert-butylo-25,26,27,28-tetrakis(3-dietoksyfosforylopropoksy)kaliks[4]aren i badano jego właściwości kompleksujące w membranowych elektrodach jonoselektywnych. Związek wykazuje selektywność na jony wapnia oraz na kationy litu. Wyznaczono stałe tworzenia kompleksów z wymienionymi jonami w membranie elektrody.
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Anaerobic consortia mediate Mn(IV)-dependent anaerobic oxidation of methane
PublicationManganese-dependent anaerobic oxidation of methane (Mn-AOM) is a major methane sink and vital to mitigating global warming. However, it is difficult for microorganisms to mediate electron transfer between the hardly dissolved CH4 and insoluble Mn(IV) minerals, leading to poor understanding of species mediating Mn-AOM. This study successfully enriched an anaerobic consortium mediating AOM driven by Mn-dependent respiratory growth,...
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Microcapsules and their applications in pharmaceutical and food industry.
PublicationMicroencapsulation is a process in which tiny particles or droplets are surrounded by a coating or embedded in a homogeneous or heterogeneous matrix, to generate small capsules in size range from a few to few thousand micrometers. The material inside the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is sometimes called shell, coating, wall material, or membrane. It has found application in...
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Minimal surfaces and conservation laws for bidimensional structures
PublicationWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...