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Wyniki wyszukiwania dla: fragmentation
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Electron-Induced Decomposition of Uracil-5-yl O-(N,N-dimethylsulfamate): Role of Methylation in Molecular Stability
PublikacjaThe incorporation of modified uracil derivatives into DNA leads to the formation of radical species that induce DNA damage. Molecules of this class have been suggested as radiosensitizers and are still under investigation. In this study, we present the results of dissociative electron attachment to uracil-5-yl O-(N,N-dimethylsulfamate) in the gas phase. We observed the formation of 10 fragment anions in the studied range of electron...
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Labellum and gynostemium micromorphology in Polystachya (Orchidaceae)
PublikacjaPolystachya is a large, pantropical orchid genus of 200 species, most of which occur as epiphytes in sub-saharan Africa. The three-lobed labellum of most Polystachya species possesses a fleshy callus and various types of trichomes and papillae. In this paper, we present the results of micromorphological studies on the labellum of 20 species, representing eight of the 13 sections in the genus, using scanning electron microscopy...
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Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography-tandem mass spectrometry
PublikacjaOxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2 isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and...
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Chemical and biological evaluation of antioxidant activity of endogenous redox-active compounds compared to plant-derived exogenous antioxidants
PublikacjaThe research conducted so far has shown that endogenous antioxidants, despite being regarded as the first line of antioxidant defense, may not be sufficient to maintain redox homeostasis in cells exposed to oxidative stress. The results obtained in the doctoral dissertation show that endogenous redox-active compounds were moderate or weak scavengers of ABTS and DPPH radicals, while in cellular setting, their impact on the reducing...
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Learning sperm cells part segmentation with class-specific data augmentation
PublikacjaInfertility affects around 15% of couples worldwide. Male fertility problems include poor sperm quality and low sperm count. The advanced fertility treatment methods like ICSI are nowadays supported by vision systems to assist embryologists in selecting good quality sperm. Computer-Assisted Semen Analysis (CASA) provides quantitative and qualitative sperm analysis concerning concentration, motility, morphology, vitality, and fragmentation....
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Polyacrylamide substrate viscosity impact on temozolomide activity in glioblastoma cells by flow cytometry and rheological measurements
Dane BadawczeDataset includes raw data on cell lines LN-229 and LN-18 treated with temozolomide measured by flow cytometry, rheometry and cell projections. It also includes calculations necessary for creation of figures and conclusions based on those figures in the publication titiled: "Substrate viscosity impairs temozolomide-mediated inhibition of glioblastoma...
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Decomposition of halogenated nucleobases by surface plasmon resonance excitation of gold nanoparticles
PublikacjaHalogenated uracil derivatives are of great interest in modern cancer therapy, either as chemotherapeutics or radiosensitisers depending on their halogen atom. This work applies UV-Vis spectroscopy to study the radiation damage of uracil, 5-bromouracil and 5- uorouracil dissolved in water in the presence of gold nanoparticles upon irradiation with an Nd:YAG ns-pulsed laser operating at 532nm at dierent uences. Gold nanoparticles...
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MINERAL MATTER IN MUNICIPAL SOLID WASTE
PublikacjaMunicipal solid waste (MSW) contains mineral materials which are seldom considered as a potential resource. Currently, the waste management sector pays attention to recyclable parts, biodegradable material, waste-to-energy fraction, and residues after waste reuse and recycle. In contrast, this study focus as on the mineral matter in MSW. The aim was to analyze and discuss the sources of mineral matter in MSW, the impact which the...
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Convenient identification of desulfoglucosinolates on the basis of mass spectra obtained during liquid chromatography-diode array-electrospray ionisation mass spectrometry analysis: Method verification for sprouts of different Brassicaceae species extracts
PublikacjaOver the past decade, glucosinolates (GLs) present in different tissues of Brassicaceae and their breakdown products, especially isothiocyanates formed after myrosinase catalyzed hydrolysis, have been regarded as not only environment friendly biopesticides for controlling soilborne pathogens, but most importantly as promising anticarcinogenic compounds. For these reasons, the identification and quantitative determination of the...
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Identification and characterization of the Indian Yellow dyestuff and its degradation products in historical oil paint tube by liquid chromatography mass spectrometry
PublikacjaAn analytical protocol for identification of dyes using reversed phase liquid chromatography-mass spectrometry with atmospheric pressure electrospray ionization (LC-ESI/MS) is presented. The developed method has been successfully applied in identification of euxanthic acid and euxanthone, the main components of the Indian Yellow dye in a historical oil paint tube produced by Richard Ain`es, a recognizable French company supplying...
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Linear revitalization - problems and challenges. Discursive article
PublikacjaThe aim of the article, defined by the author as discursive, is to give the answer as to whether within ‘revitalization’ we should distinguish the notion of ‘linear revitalization’ – not yet defined in Polish and English-language literature. The author presents the thesis that we should do so by presenting the idea, its specific character and its role. This kind of action seems to have, in the author’s opinion, a positive influence...
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Relationship between conversion rate of glucosinolates to isothiocyanates/indoles and genotoxicity of individual parts of Brassica vegetables
PublikacjaThe studies on the characterisation of glucosinolates (GLs) and their breakdown products in Brassicaceae species focus mainly on the edible parts. However, other products, e.g., dietary supplements, may be produced also from non-edible parts such as roots or early forms of growth: seeds or sprouts. Biological activity of these products depends on quantitative and qualitative GL composition, but is also strictly determined by GL...
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Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulses—A 5-Bromouracil case study
PublikacjaABSTRACT Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to...
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Electrochemistry/mass spectrometry (EC/MS) for fast generation and identification of novel reactive metabolites of two unsymmetrical bisacridines with anticancer activity.
PublikacjaThe development of a new drug requires knowledge about its metabolic fate in a living organism, regarding the comprehensive assessment of both drug therapeutic activity and toxicity profiles. Electrochemistry (EC) coupled with mass spectrometry (MS) is an efficient tool for predicting the phase I metabolism of redox-sensitive drugs. In particular, EC/MS represents a clear advantage for the generation of reactive drug transformation...
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Comparison of classical and modern approach of determination of highly polar compounds by High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry
PublikacjaAbstract: Sugars and sugar alcohols are known as highly polar compounds. Four analytes were taken into consideration for comparison of classical and modern approach of separation of highly polar substances. Mannitol was chosen as an example of simple sugar alcohol, sucrose and lactulose as examples of disaccharides and structural isomers, raffinose as an example of complex trisaccharide. Raffinose was also used as internal standard...
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Soft skills among academics: Five theoretically informed lessons for current times
PublikacjaRESEARCH OBJECTIVE: The aim of this article is to provide a comprehensive examination of the role of soft skills among academics in the context of the evolving higher-education landscape. THE RESEARCH PROBLEM AND METHODS: We use a scoping review of existing literature to discuss the importance of soft skills in academia. Through critical analysis and synthesis, we identify patterns and gaps in current knowledge and develop five...
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Distinct cellular uptake patterns of two anticancer unsymmetrical bisacridines and their metabolic transformation in tumor cells.
PublikacjaUnsymmetrical bisacridines (UAs) represent a novel class of anticancer agents. Their high cytotoxicity towards multiple human cancer cell lines and inhibition of human tumor xenograft growth in nude mice signal their potential for cancer treatment. Therefore, the mechanism of their strong biological activity is broadly investigated. Here, we explore the efflux and metabolism of UAs, as both strongly contribute to the development...
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Elucidation of transformation pathway of ketoprofen, ibuprofen, and furosemide in surface water and their occurrence in the aqueous environment using UHPLC-QTOF-MS
PublikacjaThe identification and determination of transformation products (TPs) of pharmaceuticals is essential nowadays, in order to track their fate in the aqueous environment and, thus, to estimate the actual pollution. However, this is a challenging task due to the necessity to apply high-resolution instruments enable to detect known and unknown compounds. This work presents the use of liquid chromatography quadrupole time-of-flight...
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Activated sodium percarbonate-ozone (SPC/O3) hybrid hydrodynamic cavitation system for advanced oxidation processes (AOPs) of 1,4-dioxane in water
PublikacjaHydrodynamic cavitation (HC) was employed to activate sodium percarbonate (SPC) and ozone (O3) to degrade recalcitrant 1,4-dioxane. The degradation efficiency > 99 % with a rate constant of 4.04 × 10−2 min−1 was achieved in 120 min under the optimal conditions of cavitation number (Cv) 0.27, pH 5, molar ratio of oxidant to pollutant (rox) 8, ozone dose of 0.86 g h−1 under 25 ± 2 °C with initial concentration of 1,4-dioxane 100...
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The relationship between standard reduction potentials of catechins and biological activities involved in redox control
PublikacjaRedox homeostasis involves factors that ensure proper function of cells. The excess reactive oxygen species (ROS) leads to oxidative stress and increased risk of oxidative damage to cellular components. In contrast, upon reductive stress, insufficient ROS abundance may result in faulty cell signalling. It may be expected that dietary antioxidants, depending on their standard reduction potentials (E°), will affect both scenarios....
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Identification of novel halogenated naturally occurring compounds in marine biota by high-resolution mass spectrometry and combined screening approaches
PublikacjaMarine animals, plants or bacteria are a source of bioactive naturally-occurring halogenated compounds (NHCs) such as bromophenols (BPs), bromoanisoles (BAs) and hydroxylated or methoxylated analogues of polybrominated diphenyl ethers (HO-PBDEs, MeO-PBDEs) and bromobiphenyls (HO-BBs, MeO-BBs). This study applied a comprehensive screening approach using liquid chromatography high-resolution mass spectrometry and combining target,...
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Review on friction stir welding of dissimilar magnesium and aluminum alloys: Scientometric analysis and strategies for achieving high-quality joints
PublikacjaMagnesium and aluminum alloys continually attract interest as lightweight structural materials for transport applications. However, joining these dissimilar alloys is very challenging. The main obstacle that hinders progress in dissimilar Mg-Al joining is the formation of brittle intermetallic compounds (IMCs). As a solid-state joining technique, FSW is an excellent candidate to attenuate the deleterious IMC effects in dissimilar...
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Analysis of the influence of polystyrene microplastics and their derivatives on the DNA of human colon epithelial cells HT29 with the comet assay
PublikacjaWe have been using plastic for almost a century and nowadays a lot of them circulates as pollutants in the environment and still defragmenting to micro and nanoscale. The exposition through the food chain and its precise impact on human health is still not clear. In our study, we tested real food packaging after contact with food products and real thermoinsulation and environmental samples of polystyrene in different model liquids,...
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THE STUDY OF WATER POLLUTION OF THE LOWER VISTULA RIVER BY PLASTIC PARTICLES
PublikacjaSince the beginning of widespread use of plastic its consumption and production has been constantly increasing. As a result of human activity part of waste ends up in our environment and is deposited in each of the elements of the biosphere. These impurities can be in the form of large elements, small particles fragmented to macroscopic level (pellets, facial scrub grains) and the microparticles visible under a microscope. Particularly...
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Antitumor DNA-Damaging C-1748 is a New Inhibitor of Autophagy that Triggers Apoptosis in Human Pancreatic Cancer Cell Lines
PublikacjaDespite the enormous progress that has been made over the past decades in diagnosis, treatment and prevention of many types of tumors, survival rates in pancreatic cancer still remain poor. Pancreatic cancer is one of the most malignant and chemoresistant tumors and the profound mechanism supporting these phenomena is the constitutively activated prosurvival autophagy. The antitumor 1-nitroacridine derivative C-1748 belongs to...
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Paweł Możejko dr hab.
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The use of fast molecular descriptors and artificial neural networks approach in organochlorine compounds electron ionization mass spectra classification
PublikacjaDeveloping of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and...
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Formation of CN (B2∑+) radicals in the vacuum-ultraviolet photodissociation of pyridine and pyrimidine molecules
PublikacjaFormation of the excited CN(B2∑+) free radicals in the photodissociation of pyridine (C5H5N) and pyrimidine (C4H4N2) molecules was investigated over the energy ranges 16–27 and 14.7–25 eV, respectively. Photon-induced fluorescence spectroscopy was applied to detect the vibrationally and rotationally excited CN radicals by recording the B2∑+→X2∑+ emission bands (violet system). The measured dissociation yield curves demonstrate...
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Dissociative multi-photon ionization of isolated uracil and uracil-adenine complexes
PublikacjaRecent multi-photon ionization (MPI) experiments on uracil revealed a fragment ion at m/z 84 that was proposed as a potential marker for ring opening in the electronically excited neutral molecule. The present MPI measurements on deuterated uracil identify the fragment as C3H4N2O+ (uracil+ less CO), a plausible dissociative ionization product from the theoretically predicted open-ring isomer. Equivalent measurements on thymine...
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Anionic states of C6Cl6 probed in electron transfer experiments
PublikacjaThis is the first comprehensive investigation on the anionic species formed in collisions of fast neutral potassium (K) atoms with neutral hexachlorobenzene (C6Cl6) molecules in the laboratory frame range from 10 up to 100 eV. In such ion-pair formation experiments, we also report a novel K+ energy loss spectrum obtained in the forward scattering giving evidence of the most accessible electronic states. The vertical electron affinity...