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Search results for: FURAN FRAGMENTATION
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Buserelin Acetate Reduces Mortality and DNA Defragmentation of Bovine Sperm Cells Exposed to Oxidative Stress
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Ionization and fragmentation of the six-membered heterocycles containing oxygen – Comparative studies of electron and photon impact on the 3,4-dihydro-2H-pyran molecules
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Inner-shell fragmentation of molecules into neutral fragments in high-Rydberg states induced by soft X-ray excitation with pulsed-field ionization
PublicationIn the present communication, we will show the results of measurements probing the production of neutral high-Rydberg fragments at the K edges of the molecules containing oxygen and nitrogen atoms. The experiments were performed at the Gas Phase beamline of the Elettra synchrotron radiation laboratory (Trieste, Italy), exploiting a combined soft X-ray excitation with pulsed-field ionization and ion time-of-flight (TOF) spectrometry...
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A Novel [4+2] Cycloaddition Reaction Involving Lawesson’s Reagent. Structure and Specific Fragmentations of a New Cyclic 1,2-Thiaphosphinane-4-one
PublicationA crude morpholine enamine of acetone treated with Lawesson’s reagent unexpectedly yielded a six-membered thiaphosphinane-4-one. This compound is the first example of a new class of heterocycles. It has been proven that it is formed from 4-methyl-2-morpholino-1,3-pentadiene which is usually present in crude morpholine enamine batches. A mechanism of this regioselective reaction was postulated and a characteristic chair-like conformation...
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Superexcited states in the vacuum-ultraviolet photofragmentation of isoxazole molecules
PublicationThe photofragmentation of isoxazole molecules producing excited atomic and molecular fragments has been investigated over the energy range 16-50 eV, using photon-induced fluorescence spectroscopy. The following fragments have been identified by their fluorescence: the excited hydrogen atoms H(n), n = 3-7 and the diatomic CH(A2Δ, B2Σ−), CN(B2Σ+) and C2(d3Πg) fragments. The diatomic fragments are vibrationally and highly rotationally...
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Ocena wpływu pokarmowych kwasów nukleinowych i ich komponentów na replikacyjną i naprawczą syntezę DNA w modelach komórek ludzkiego układu pokarmowego
PublicationKwasy nukleinowe, do których należą DNA i RNA, są podstawowymi elementami każdej komórki niezbędnymi do prawidłowego funkcjonowania organizmu. Pomimo, że cząsteczki te stanowią również nieodłączne składniki produktów żywnościowych spożywanych przez człowieka, to badania na temat ich zawartości w żywności oraz wartości odżywczej są ograniczone. Wyniki uzyskane w niniejszej pracy doktorskiej pokazały istotne różnice w ilości, wielkości...
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Neutral Dissociation of Pyridine Evoked by Irradiation of Ionized Atomic and Molecular Hydrogen Beams
PublicationThe interactions of ions with molecules and the determination of their dissociation patterns are challenging endeavors of fundamental importance for theoretical and experimental science. In particular, the investigations on bond-breaking and new bond-forming processes triggered by the ionic impact may shed light on the stellar wind interaction with interstellar media, ionic beam irradiations of the living cells, ion-track nanotechnology,...
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Public spaces connecting cities. Green and Blue Infrastructures potential.
PublicationA city fragmentation causes a lot of negative effects in urban environment such as: disconnecting the environmental, functional and compositional relations, a loss of urban compactness, chaotic development, visual chaos, a domination of technical landscape, reduction of security. This is why one of main challenges for urban planners is to connect the fragmented structures by creating friendly, attractive and safe public space....
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PHOTON LUMINESCENCE STUDIES OF TETRAHYDROFURAN FOLLOWING TRIHYDROGEN CATIONS IMPACT IN THE 20–1000 EV ENERGY RANGE
PublicationPhoton emission arising during tetrahydrofuran (C4H8O, THF) fragmentation initiated by H3 + ion impact has been studied experimentally. Luminescence fragmentation spectra and the relative emission cross-sections of the excited fragments have been measured using collision-induced emission spectroscopy in the 20–1000 eV energy range. The main features in the spectra are the H Balmer series lines, whose intensities decrease with increasing...
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Application of gas chromatography,mass spectrometry and olfactometry for quality assessment of selected food products = Zastosowanie chromatografii gazowej, spektrometrii mas i olfaktometrii w ocenie jakości wybranych produktów spożywczych
PublicationStosując mikroekstrakcję do fazy stacjonarnej z fazy nadpowierzchniowej jako metodę przygotowania próbek i chromatografię gazową (GC) ze spektrometrią mas (MS) i olfaktometrią (O) jako metodę oznaczeń końcowych oznaczono lotne związki w spirytusach i miodach. Identyfikację przeprowadzono przez porównanie widm masowych z widmami z biblioteki NIST. Dodatkowo, wykrywane przez panel oceniający związki zapachowe rejestrowano w formie...
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4-[(tert-Butyldimethylsilyl)oxy]-6-methoxy-7-methyl-5-(oxiran-2-ylmethyl)-2-benzofuran-3(1H)-one
PublicationThe title compound, C19H28O5Si, was obtained in the reaction of 1,3-dihydro-4-[(tert-butyldimethylsilyl)oxy]-6-methoxy-7-methyl-3-oxo-5-(prop-2-enyl)isobenzofuran with meta-chloroperbenzoic acid. This reaction is one of the stages of the total synthesis of mycophenolic acid, which we attempted to modify. The title compound forms crystals with only weak intermolecular interactions. The strongest stacking interaction is found between...
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Electron interactions with Bis(pentamethylcyclopentadienyl) titanium(IV) dichloride and difluoride
PublicationWe present a combined experimental and theoretical study of the interaction of electrons with Bis(pentamethylcyclopentadienyl)titanium(IV) dichloride (Cp∗2TiCl2) and difluoride (Cp∗2TiF2). We report the experimental measurements of partial cross sections for the dissociative electron attachment (DEA) and the electron ionization (EI) mass spectra of isolated molecules. Estimates of the absolute cross sections are done on the basis...
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Organohalogen compounds in the environment.
PublicationPrzedyskutowano problem związków chloroorganicznych w środowisku, takich jak: pestycydy chloroorganiczne, polichlorowane bifenyle, polichlorowane dibenzodioksyny i furany. Omówiono podstawowe właściwości fizykochemiczne, toksykologiczne oraz ścieżki przemian w środowisku.
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Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea
PublicationDissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation...
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Dissociative photo-double-ionization of isoxazole
PublicationIn the present communication, we present results on the photo-double-ionization and fragmentation of the isoxazole molecules. The experiments were carried out at the CiPo beamline at the Elettra-Sincrotrone radiation facility exploiting the VUV excitation and the ion time-of-flight spectrometry combined with the PEPICO technique. The dissociative processes where only one electron is emitted are quite well known [1]. However, double...
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Elastic electron scattering and vibrational excitation of isoxazole molecules in the energy range from 2 to 20 eV
PublicationDifferential cross sections for elastic electron scattering and the excitation of the C-H vibrational modes of isoxazole molecules were measured in the energy range from 2 to 20 eV and over the scattering angle range from 10◦ to 180◦. The cross sections at the scattering angles of and above 90◦ were accessible with the use of a magnetic angle changer. The differential cross sections were integrated to yield integral and momentum...
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Photofragmentation of tetrahydrofuran molecules in the vacuum-ultraviolet region via superexcited states studied by fluorescence spectroscopy
PublicationPhotofragmentation of tetrahydrofuran molecules in the vacuum-ultraviolet region, producing excited atomic and molecular fragments, has been studied over the energy range 14-68 eV using photon-induced fluorescence spectroscopy. Excited hydrogen atoms H(n), n = 3-11, have been detected by observation of the Hα to Hı lines of the Balmer series. The diatomic CH(A2Δ), CH(B2Σ-) and C2(d3Πg) fragments, which are excited to low vibrational...
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Moving object tracking algorithm evaluation in autonomous surveillance system
PublicationResults of evaluation of video object tracking algorithm being a part of an autonomous surveillance system are presented. The algorithm was investigated employing a set of benchmarks recorded locally. The precision of object detection, evaluated with such metrics as fragmentation, object area recall and object precision, is in focus. The experiments aimed at examining the detection quality using various object detection algorithm...
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Podejście środowiskowe w dydaktyce projektowania Sustainable approach in teaching of design
PublicationThe aim of the paper is to assess the inclusion of academic teaching design to the process of sustainable development and proposals for an integrated approach in training architects. The article presents an original interpretation of environmental design in the field of architecture and urban planning. The significance of the environmental perspective is presented in the context of growing spatial and social fragmentation. The...
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Influence of Property Division on the Technical Condition of a Building
PublicationIn this article, the correlation between a technical condition of a building and property division is analyzed and assessed. In the course of the usage of a building, the process of its degradation and the increase in the demands of property occupants can be observed. There is a direct connection between the difficult technical condition of a building and the fragmentation of the ownership structure. Although not considered in...
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Collision-induced luminescence spectra of pyridine bombarded by 1000 eV He+ cations
PublicationHere we show collision-induced luminescence spectra measured for collisions of the He+cations with thearomatic six-membered ring of the pyridine molecule (C5H5N). Distinct emission bands due to the CH(A2Δ→X2Πr;B2Σ+→X2Πr;C2Σ+→X2Πr), CN(B2Σ+→X2Σ+), C2(d3Πg→a3Πu), and NH(A3Π→X3Σ−) transitions, aswell as atomic H, He, and C lines have been observed. Apart from the He atoms, all the emitters arise from thefragmentation of the pyridine...
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Mass spectrometry based identification of geometric isomers during metabolic stability study of a new cytotoxic sulfonamide derivatives supported by quantitative structure-retention relationships
PublicationA set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships...
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A headspace solid-phase microextraction method development and itsapplication in the determination of volatiles in honeys by gas chromatography
PublicationThe first part of the paper presents the detailed optimisation of all steps of the determination procedureof volatiles from Polish honeys by headspace solid-phase microextraction (HS-SPME) as the sample preparationmethod and gas chromatography/mass spectrometry (GC-MS) as the method of final determination.The methodology of semi-quantative analysis allowed the isolation and identification of volatile fractioncompounds from popular...
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Efficient Method for the Synthesis of Functionalized Basic Maleimides
PublicationA three-step procedure involving Diels-Alder condensation of maleic anhydride with furane, formation of N-substituted imide upon reaction with appropriate diamine and a final retro Diels-Alder regeneration of the maleic carbon-carbon double bond is proposed for an unequivocal synthesis of N-substituted basic maleimides. The novel method is characterized by mild reaction conditions, easy work-up, high yields and no need for additional...
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Import Intensity of Production, Tasks and Wages: Microlevel Evidence for Poland.
PublicationObjective: This article relates to recent literature on labour market consequences of production fragmentation within Global Value Chains, analysed in the presence of workers’ heterogeneity and differences in the task content of jobs. The main aim is to assess if there is a relationship between wages of Polish workers and the degree of Polish production dependence on imported inputs. Research Design & Methods: Using microdata from...
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The need for linear revitalization. Gdynia case
PublicationThe aim of the article is to discuss the need of defining and implementation of the linear revitalization - the new approach related to the revitalization processes. The results of the preliminary investigations indicate that this kind of revitalization seems to be an important tool supporting city management and planning, especially in cases of cities fragmentation - causing lack of physical, social, economic and ecological cohesion....
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<i>N,N,N</i>-Trimethyl-N-(methyl 5-deoxy-2,3-<i>O</i>-isopropylidene-β-D-ribofuranosid-5- yl)ammonium 4-methylbenzenesulfonate sesquihydrate.
PublicationThe structure of the title compound, [C12H24NO4][C7H7O3S]·1.5H2O, contains alternating layers parallel to (001) of hydrophobic and polar character, stabilized by C-H...O hydrogen bonding. The furan ring adopts an envelope conformation with the C(OMe) atom as the flap, and the dioxolane ring is twisted about one of the O-C(methine) bonds. A comparison to related compounds is presented. The tosylate-O atoms were disordered over two...
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Position in global value chains and wages in Central and Eastern European countries
PublicationThis paper examines the relationship between the relative position of industries in Global Value Chains (GVC) and wages in 10 Central and Eastern European countries. We combine GVC measures of global import intensity of production, upstreamness and the length of the value chain with micro-data on workers. We find that the wages of Central and Eastern European countries workers are higher when their industry is at the beginning...
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Global Value Chains and Wages: Multi-Country Evidence from Linked Worker-Industry Data
PublicationThis paper uses a multi-country microeconomic setting to contribute to the literature on the nexus between production fragmentation and wages. Exploiting a rich dataset on over 110,000 workers from nine Eastern and Western European countries and the United States, we study the relationship between individual workers’ wages and industry ties into global value chains (GVCs). We find an inverse (but weak) relationship between the...
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Electron attachment to representative cations composing ionic liquids
PublicationUsing ab initio electronic structure methods with flexible atomic orbital basis sets, we investigated the electronic structure and stability of reduction products of selected representative cations (C+) constituting ionic liquids. We found that an electron attachment to such cations leads to the neutral radicals, whereas a subsequent attachment of another (i.e., excess) electron leads to adiabatically stable anions only in two...
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Towards β-selectivity in functional estrogen receptor antagonists
PublicationBased on the benzo[b]naphtho[1,2-d]furan and benzo[b]naphtho[1,2-d]thiophene frameworks, a series of ligands with different basic side chains (BSCs) has been synthesized and pharmacologically evaluated. Also, their binding modes have been modelled using docking techniques. It was found that the introduction of a BSC in these systems brings about a decrease of affinity for both estrogen receptors α and β in an in vitro competitive...
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Nowe stanowiska Dicranum viride (Dicranaceae) w północno-wschodniej Polsce na tle jego rozmieszczenia w województwie podlaskim
PublicationDicranum viride (Sull. & Lesq.) Lindb. is a rare moss species from the Dicranaceae family. It is strictly protected in Poland and is considered as a relic of primeval forests. The plant is also included in Annex II of the Natura 2000 Habitats Directive and Annex I of the Bern Convention. Its populations are threatened by habitat fragmentation and economic use of forest...
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Low-energy interactions related to atmospheric and extreme conditions
PublicationThis Topical Issue, entitled “Low-Energy Interactions Related to Atmospheric and Extreme Conditions”, showcases a collection of eighteen articles that reported recent theoretical and experimental findings pertaining to the following topics: – low-energy interactions of charged particles (electrons [1–7], protons [8], positrons [9]), and photons [10] with atoms and molecules of biological [1–4,7,8], astrochemical [10], industrial,...
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A simple modification to improve the accuracy of methylation-sensitive restriction enzyme quantitative polymerase chain reaction
PublicationDNA digestion with endonucleases sensitive to CpG methylation such as HpaII followed by polymerase chain reaction (PCR) quantitation is commonly used in molecular studies as a simple and inexpensive solution for assessment of region-specific DNA methylation. We observed that the results of such analyses were highly overestimated if mock-digested samples were applied as the reference.We determined DNA methylation levels in several...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublicationWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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Cross sections for electron collision with five-membered ring heterocycles
PublicationCałkowity absolutny przekrój czynny (TCS) na rozpraszanie elektronów na cząsteczce izoksazolu (CH)3NO, został zmierzony przy wykorzystaniu liniowej techniki transmisyjnej dla energii zderzenia od 1 do 400 eV. Zależność energetyczna funkcji TCS jest typowa dla cząsteczek silnie polarnych; w całym zakresie badanych energii wartość TCS maleje wraz ze wzrostem energii zderzenia. Zaobserwowano wąskie struktury rezonansowe w okolicy...
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IZOLACJA I IDENTYFIKACJA NATURALNYCH SUBSTANCJI BARWIĄCYCH OBECNYCH W PRÓBKACH FARB ARTYSTYCZNYCH I TKANINACH POCHODZENIA HISTORYCZNEGO
PublicationNatural organic dyes are group of substances that belong to various types of chemical compounds. The most commonly used in paintings and dyeing textiles were naturally occurring dyestuffs from group of anthraquinones, flavones and indigoid dyes. Identification of coloring substances present in historical artistic paints provides relevant information for a wide range of specialists dealing with works of art and in the field of conservation science....
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Effect of microstructure on mechanical properties of BA1055 bronze castings
PublicationThe article presents research results performed on aluminum bronze CuAl10Fe5Ni5 (BA1032) castings used for marine propellers. Metallographic studies were made on light microscope and a scanning electron microscope to assess quantitatively and qualitatively the alloy microstructure. It has been shown that the shape, size and distribution of the iron-rich phase precipitates in bronze microstructure significantly affect its mechanical...
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Tetrahedrally modified MnMe0.1Co1.9O4 (Me = Zn, Mg, Li) spinels for non-enzymatic glucose sensing
PublicationIn this work, tetrahedrally modified MnMe0.1Co1.9O4 (Me = Zn, Mg, Li) spinels were prepared via the sol–gel synthesis method with subsequent ball-milling fragmentation. The prepared samples were evaluated as glucose–sensing catalyst. The reference MnCo2O4 spinel exhibited a sensitivity of 49 µA mM−1 cm−2 and a nonlinearity error of 5.2% in the response range from 0.02 to 1 mM. The partial substitution of cobalt in the reference...
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The Usefulness of Cyclic Diamidines with Different Core-substituents as Antitumor Agents
PublicationA series of related polycationic compds. has been screened for potential antitumor activity by the NCI's in vitro testing (one dose primary anticancer assay and the NCI-60 full panel screening). The GI50 values of triazines 3 and 4 are on av. 1.9 μM and 2.4 μM, resp. Furan 8 deserves mention too (1.9 μM). The biol. test results showed that carbazole 10 possessed cytotoxic activity in the nanomolar range, much better than...
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Electron attachment to hexafluoropropylene oxide (HFPO)
PublicationWe probe the electron attachment in hexafluoropropylene oxide (HFPO), C3F6O, a gas widely used in plasma technologies. We determine the absolute electron attachment cross section using two completely different experimental approaches: (i) a crossed-beam experiment at single collision conditions (local pressures of 5 × 10−4 mbar) and (ii) a pulsed Townsend experiment at pressures of 20–100 mbar. In the latter method, the cross sections...
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Elimination and migration of hydrogen in the vacuum-ultraviolet photodissociation of pyridine molecules
PublicationElimination of the excited hydrogen atoms H(n), n = 4–7, and hydrogen migration in formation of the excited NH(A 3Π) free radicals in the photodissociation of pyridine, C5H5N, molecules have been studied over the 17.5–70 eV photon energy range. In the measurements the photon-induced fluorescence spectroscopy technique has been applied. Both fragments are produced through excitation of pyridine molecules into higher-lying superexcited...
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Dehydrogenation in electron-induced dissociative ionization of pyridine molecule
PublicationThe electron-impact dissociative ionization of pyridine has been investigated using mass spectrometry. Thirty-two well-resolved mass peaks have been identified in the cation mass spectra and assigned to the most likely ionic molecular fragments. The new sixteen ionic fragments' appearance energies have been determined, and sixteen others remeasured. The total cross-section for electron-impact ionization of pyridine has been measured...
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Resistive gas sensors – Perspectives on selectivity and sensitivity improvement
PublicationResistive gas sensors are very popular and relatively inexpensive; they can operate at elevated or room temperature for years on end. The main disadvantage of resistive gas sensors is their limited selectivity and sensitivity, but various methods have been applied to improve their behavior. The composition of the porous gas sensing layer, or changes in the sensor’s operating temperature, can enhance the gas detection ability. Furthermore, emerging...
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VUV photofragmentation of the six-membered heterocyclic molecules containing oxygen
PublicationCancer is a significant public health concern worldwide, which results in millions of deaths each year. The standard cure routine for cancer is surgery, and nowadays, radiotherapy or a hadrontherapy. Depending on the type of cancer, patients may undergo additional treatment, including targeted therapy. A combination of radio- or hadron-therapy with proper drug treatment can inhibit the proliferation of cancer cells and thus can...
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Comparing Apples and Oranges: A Mobile User Experience Study of iOS and Android Consumer Devices
PublicationWith the rapid development of wireless networks and the spread of broadband access around the world, the number of active mobile user devices continues to grow. Each year more and more terminals are released on the market, with the smartphone being the most popular among them. They include low-end, mid-range, and of course high-end devices, with top hardware specifications. They do vary in build quality, utilized type of material,...
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Environmental Fate of Two Psychiatric Drugs, Diazepam and Sertraline: Phototransformation and Investigation of their Photoproducts in Natural Waters
PublicationExperimental studies were conducted to investigate the photodegradation of diazepam and sertraline, two of the most frequently used psychiatric drugs, induced by xenon lamp irradiation, which overlap the sunlight spectra, and natural sunlight. Degradation kinetics was established indicating the occurrence of autocatalytic reactions. The application of liquid chromatography coupled to quadrupole time-of-flight mass spectrometry...
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Influence of the ionic strength on the amyloid fibrillogenesis of hen egg white lysozyme
PublicationThe study investigates the role of the electrostatic interactions in the fibrillation of the hen egg white lysozyme (HEWL). In order to achieve this aim the influence of the cations Na+, Mg2+ and Al3+ on the amyloid fibril formation and amorphous aggregation was tested. The amyloids are formed in the solution without added salt but the Thioflavin T fluorescence gives the false-negative result. In these conditions, the HEWL fibrils...
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Palindromic carbazole derivatives: unveiling their antiproliferative effect via topoisomerase II catalytic inhibition and apoptosis induction
PublicationHuman DNA topoisomerases are essential for crucial cellular processes, including DNA replication, transcription, chromatin condensation, and maintenance of its structure. One of the significant strategies employed in cancer treatment involves the inhibition of a specific type of topoisomerase, known as topoisomerase II (Topo II). Carbazole derivatives, recognised for their varied biological activities, have recently become a significant...
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Key-Marker Volatile Compounds in Aromatic Rice (Oryza sativa) Grains: An HS-SPME Extraction Method Combined with GC×GC-TOFMS
PublicationThe 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...