Search

Your search keyword '"Gawdzik, Barbara"' showing total 203 results
Start Over Author "Gawdzik, Barbara" Search Limiters Full Text
203 results on '"Gawdzik, Barbara"'

2. Analysis of the Model of Atherosclerosis Formation in Pig Hearts as a Result of Impaired Activity of DNA Repair Enzymes

Author

Paslawski, Robert, primary, Kowalczyk, Paweł, additional, Paslawska, Urszula, additional, Wiśniewski, Jerzy, additional, Dzięgiel, Piotr, additional, Janiszewski, Adrian, additional, Kiczak, Liliana, additional, Zacharski, Maciej, additional, Gawdzik, Barbara, additional, Kramkowski, Karol, additional, and Szuba, Andrzej, additional

Published
2024
Full Text
View/download PDF

9. Aluminium(III) Oxide—The Silent Killer of Bacteria

Author

Schabikowski, Mateusz, primary, Kowalczyk, Paweł, additional, Karczmarska, Agnieszka, additional, Gawdzik, Barbara, additional, Wypych, Aleksandra, additional, Kramkowski, Karol, additional, Wrzosek, Karol, additional, and Laskowski, Łukasz, additional

Published
2023
Full Text
View/download PDF

15. A Series of Green Oxovanadium(IV) Precatalysts with O, N and S Donor Ligands in a Sustainable Olefins Oligomerization Process

Author

Urbaniak, Mariusz, primary, Pobłocki, Kacper, additional, Kowalczyk, Paweł, additional, Kramkowski, Karol, additional, Drzeżdżon, Joanna, additional, Gawdzik, Barbara, additional, Świtała, Patrycja, additional, Miler, Maja, additional, Heleniak, Daria, additional, Rybiński, Przemysław, additional, and Jacewicz, Dagmara, additional

Published
2022
Full Text
View/download PDF

17. Functionalised Anodised Aluminium Oxide as a Biocidal Agent

Author

Schabikowski, Mateusz, primary, Laskowska, Magdalena, additional, Kowalczyk, Paweł, additional, Fedorchuk, Andrii, additional, Szőri-Dorogházi, Emma, additional, Németh, Zoltán, additional, Kuźma, Dominika, additional, Gawdzik, Barbara, additional, Wypych, Aleksandra, additional, Kramkowski, Karol, additional, and Laskowski, Łukasz, additional

Published
2022
Full Text
View/download PDF

19. Chalcone-Derived Lactones: Synthesis, Whole-Cell Biotransformation, and Evaluation of Their Antibacterial and Antifungal Activity.

Author

Gładkowski, Witold, Siepka, Monika, Żarowska, Barbara, Białońska, Agata, Gawdzik, Barbara, Urbaniak, Mariusz, and Wawrzeńczyk, Czesław

Subjects
ANTIBACTERIAL agents, LACTONES, BIOCONVERSION, ASPERGILLUS niger, CHALCONE, ANTI-infective agents
Abstract

Four compounds with lactone moiety were synthesized from chalcone 1 in three- or four-step synthesis. γ-Bromo-δ-lactone 5 was the only product of bromolactonization of acid 4 whereas bromolactonization of ester 3, apart from lactone 5 also afforded its isomer 6 and two diastereoisomeric δ-hydroxy-γ-lactones 7 and 8. Lactone 8 was also obtained in 88% yield as a product of simultaneous dehalogenation and translactonization of γ-bromo-δ-lactone 5 by Penicillum frequentans AM 359. Chalcone-derived lactones 5–8 were subjected to the tests on antimicrobial activity and the results compared with activity of starting chalcone 1. Obtained lactones 5–8 in most cases limited the growth of tested bacterial and fungal strains. The highest activity was found for δ-hydroxy-γ-lactone 8 which completely inhibited the growth of Staphylococcus aureus, Fusarium graminearum, Aspergillus niger, and Alternaria sp. The introduction of lactone moiety into chalcone scaffold significantly improved antimicrobial activity of the compound: γ-bromo-δ-lactone 6 and δ-hydroxy-γ-lactone 8 were significantly stronger growth inhibitors of S. aureus and F. graminearum. In the case of the latter, a clear positive effect of the lactone function on the antifungal activity was also observed for γ-bromo-δ-lactone 5. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

27. Synthesis and Characterization of Biodegradable Polymers Based on Glucose Derivatives.

Author

Gawdzik, Barbara, Bukowska-Śluz, Izabela, Koziol, Anna E., and Mazur, Liliana

Subjects
*X-ray powder diffraction, *GLUCOSE, *MONOMERS, *NUCLEAR magnetic resonance spectroscopy, *COPOLYMERS, *POLYMERS
Abstract

Syntheses of two new monomers, namely the glucose derivatives 2,3,4,6-tetra-O-acetyl-1 methacryloyl-glucopyranose (MGlc) and 2,3,4,6 tetra-O-acetyl-1-acryloylglucopyranose (AGlc), are presented. Their chemical structures were determined by the FTIR, 1H and 13C NMR spectroscopies, the single-crystal X-ray analysis, supported by the powder X-ray diffraction, and the DSC analyses. Molecules of both monomers exist in the β-anomeric form in the solid state. The variable temperature X-ray diffraction studies, supported by the DSC analyses, revealed AGlc's propensity for polymorphism and temperature-induced phase transitions. MGlc and AGlc crystallised from methanol were polymerized or copolymerized with methyl methacrylate and N-vinylpyrrolidone. The biodegradabilities of polymers as well as thermal and optical properties were studied. The results show that some properties of the obtained homopolymers and copolymers resemble those of PMMA. The main difference is that the AGlc and MGlc homopolymers are biodegradable while PMMA is not. The ternary copolymers, i.e., MGlc/AGlc-MMA-NVP lose more than 10% of their weight after six months. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

28. Assessment Study on the Solvent Resistance of Low-Density Polyethylene with Pumpkin Seed Hulls.

Author

Głogowska, Karolina, Pączkowski, Przemysław, and Gawdzik, Barbara

Subjects
PUMPKIN seeds, SOLVENTS, COMPOSITE materials, DISTILLED water, THERMAL properties, POLYMERIC composites, LOW density polyethylene
Abstract

When designing products that are made of composite materials and that contain natural fillers, it is particularly important to consider the long-term exposure of these materials to caustic liquids and substances (concentrated acids, bases), and to ensure that these products meet strict requirements for reliability and operational safety. This study investigated the effects of different solvents on the mass, mechanical, thermal, surface, and structural properties of polymer composites containing natural fillers in the form of pumpkin seed hulls. Experiments were conducted using four different filler contents (5, 10, 15, and 20 wt%) and grain sizes ranging from 0.2 to 0.4 mm and 0.6 to 0.8 mm. Hybrid injection-moulded pieces were immersed in distilled water (H2O), 1% NaOH solution, acetone (C3H6O), and toluene (C7H8) for 84 days. After that, their mechanical and thermal properties as well as their structure geometries were analysed statistically. Changes in the properties of the tested composite materials were assessed depending on the solvent type, and the statistical significance of these changes were determined. The results showed that the nature of degradation depended on the applied solvent type. It was observed that the polymer matrix of the toluene-immersed samples absorbed the liquid to a significant extent first and then underwent a gradual degradation with time. In contrast, the samples immersed in water showed a slight increase in their mass. It was found that all tested properties of the composite samples deteriorated irrespective of the solvent type. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

44. Synthesis and characterization of vinyl derivatives of naphthalene-2,7-diol as a photoluminescent dopant useful in optical materials

Author

Demirci Gokhan, Gawdzik Barbara, Gil Malgorzata, Podkoscielna Beata, Podkoscielny Wieslaw, and Bartnicki Andrzej

Subjects
Photoluminescence, Dopant, General Chemical Engineering, Diol, 02 engineering and technology, General Chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, Characterization (materials science), 010309 optics, chemistry.chemical_compound, chemistry, Optical materials, 0103 physical sciences, 0210 nano-technology, Naphthalene
Abstract

In this study synthesis and characterization of the new methacrylic derivatives of naphthalene-2,7-diol are presented. This reaction was performed in the three stages. In first stage 2,7-NAF was reacted with dimethyl sulfate in the NaOH solutions at 0°C. Next, the obtained 2,7-NAF.Me was modified by epichlorohydrine leading to epoxide compound (2,7-NAF.Me.EP). Finally, the reaction of opening oxirane rings by methacrylic acid was carried out. The chemical structures of all derivatives were confirmed by 1H and 13C NMR. Next, copolymerization reaction with methyl methacrylate (MMA), styrene (St) or divinylbenzene (DVB) was carried out. New monomer (2,7-NAF.MePM) possesses only one double bond and it can be used as a dopant in optical materials technology. The studies of their thermal properties were investigated by means TG/DTG/QMS coupled method. The influence of photoluminescence dopant on thermal stability of the obtained copolymers was also discussed.

Published
2016

45. The Influence of Lignin Diversity on the Structural and Thermal Properties of Polymeric Microspheres Derived from Lignin, Styrene, and/or Divinylbenzene

Author

Goliszek, Marta, Podkoscielna, Beata, Sevastyanova, Olena, Gawdzik, Barbara, Chabros, Artur, Goliszek, Marta, Podkoscielna, Beata, Sevastyanova, Olena, Gawdzik, Barbara, and Chabros, Artur

Abstract

This work investigates the impact of lignin origin and structural characteristics, such as molecular weight and functionality, on the properties of corresponding porous biopolymeric microspheres obtained through suspension-emulsion polymerization of lignin with styrene (St) and/or divinylbenzene (DVB). Two types of kraft lignin, which are softwood (Picea abies L.) and hardwood (Eucalyptus grandis), fractionated by common industrial solvents, and related methacrylates, were used in the synthesis. The presence of the appropriate functional groups in the lignins and in the corresponding microspheres were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), while the thermal properties were studied by differential scanning calorimetry (DSC). The texture of the microspheres was characterized using low-temperature nitrogen adsorption. The swelling studies were performed in typical organic solvents and distilled water. The shapes of the microspheres were confirmed with an optical microscope. The introduction of lignin into a St and/or DVB polymeric system made it possible to obtain highly porous functionalized microspheres that increase their sorption potential. Lignin methacrylates created a polymer network with St and DVB, whereas the unmodified lignin acted mainly as an eco-friendly filler in the pores of St-DVB or DVB microspheres. The incorporation of biopolymer into the microspheres could be a promising alternative to a modification of synthetic materials and a better utilization of lignin., QC 20191031

Published
2019
Full Text
View/download PDF

48. Antimicrobial, cytotoxic, and antioxidant activities and physicochemical characteristics of chromium(III) complexes with picolinate, dipicolinate, oxalate, 2,2′-bipyridine, and 4,4′-dimethoxy-2,2′-bipyridine as ligands in aqueous solutions

Author

Drzeżdżon, Joanna, primary, Piotrowska-Kirschling, Agnieszka, additional, Malinowski, Jacek, additional, Kloska, Anna, additional, Gawdzik, Barbara, additional, Chmurzyński, Lech, additional, and Jacewicz, Dagmara, additional

Published
2019
Full Text
View/download PDF

49. Fast bragg grating inscription in PMMA polymer optical fibres:impact of thermal pre-treatment of preforms

Author

Marques, Carlos A.F., Pospori, Andreas, Demirci, Gökhan, Çetinkaya, Onur, Gawdzik, Barbara, Antunes, Paulo, Bang, Ole, Mergo, Pawel, André, Paulo, and Webb, David J.

Abstract

In this work, fibre Bragg gratings (FBGs) were inscribed in two different undoped poly- (methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and their inscription times, temperature and strain sensitivities are investigated. The POF Bragg gratings (POFBGs) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. Two PMMA POFs are used in which the primary and secondary preforms (during the two-step drawing process) have a different thermal treatment. The PMMA POFs drawn in which the primary or secondary preform is not specifically pre-treated need longer inscription time than the fibres drawn where both preforms have been pre-annealed at 80 °C for 2 weeks. Using both UV lasers, for the latter fibre much less inscription time is needed compared to another homemade POF. The properties of a POF fabricated with both preforms thermally well annealed are different from those in which just one preform step process is thermally treated, with the first POFs being much less sensitive to thermal treatment. The influence of annealing on the strain and temperature sensitivities of the fibres prior to FBG inscription is also discussed, where it is observed that the fibre produced from a two-step drawing process with well-defined pre-annealing of both preforms did not produce any significant difference in sensitivity. The results indicate the impact of preform thermal pre-treatment before the PMMA POFs drawing, which can be an essential characteristic in the view of developing POF sensors technology.

Published
2017

50. Bragg gratings inscription using PMMA polymer optical fibers drawn from preforms with specific thermal pre-treatment

Author

Marques, Carlos A.F., Pospori, Andreas, Demirci, Gökhan, Cetinkaya, Onur, Gawdzik, Barbara, Antunes, Paulo, Mergo, Pawel, André, Paulo, Webb, David J., Scully, Patricia, and Sugden, Kate

Abstract

In this work, fiber Bragg gratings (FBGs) are inscribed in various undoped poly(methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and inscription time and their temperature and strain sensitivities are investigated. The polymer optical fiber Bragg gratings (POFBGs) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. The PMMA POFs drawn from a preform without specific thermal pre-treatment need more inscription time than the fibers drawn from a preform that has been pre-annealed at 80ºC for 2 weeks. Using both UV lasers, for the latter fiber less than half the inscription time is needed compared with a commercial undoped PMMA POF and other homemade POFs, where the preforms have not had a well-defined thermal pre-treatment. The effect on a POF from a preform that has been annealed prior to drawing is different as previously shown in the literature, where these POFs are much less sensitive to thermal treatment. Also, a proper polymerization process plays a key role as will be discussed. These results indicate the impact of preform thermal pre-treatment as well as polymerization process before the PMMA POFs drawing, which can be an essential characteristic in view of developing POF sensors technology.

Published
2016

Catalog

Books, media, physical & digital resources
See catalog results