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187 results on '"Brzezinski, Krzysztof"'

1. Three-dimensional organization of pyrrolo[3,2-b]pyrrole-based triazine framework using nanostructural spherical carbon: enhancing electrochemical performance of materials for supercapacitors

Author

Hryniewicka, Agnieszka, Breczko, Joanna, Siemiaszko, Gabriela, Papathanassiou, Anthony N., Góra-Marek, Kinga, Tarach, Karolina A., Brzezinski, Krzysztof, Ilnicka, Anna, Terzyk, Artur P., Markiewicz, Karolina H., Echegoyen, Luis, and Plonska-Brzezinska, Marta E.

Published
2023
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2. A closer look at molecular mechanisms underlying inhibition of S-adenosyl-L-homocysteine hydrolase by transition metal cations.

Author

Gawel, Magdalena, Malecki, Piotr H., Sliwiak, Joanna, Stepniewska, Marlena, Imiolczyk, Barbara, Czyrko-Horczak, Justyna, Jakubczyk, Dorota, Marczak, Łukasz, Plonska-Brzezinska, Marta Eliza, and Brzezinski, Krzysztof

Subjects
ENZYME inactivation, TRANSITION metals, CATIONS, OXIDATION, ENZYMES
Abstract

We report biochemical and structural studies on inhibiting bacterial S-adenosyl- L -homocysteine hydrolase by transition metal cations. Our results revealed diverse molecular mechanisms of enzyme inactivation. Depending on the cation, the mechanism is based on arresting the enzyme in its closed, inactive conformation, disulfide bond formation within the active site or oxidation of the intermediate form of a cofactor. [ABSTRACT FROM AUTHOR]

Published
2024
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3. Essays on effects of uncertainty on competition among firms and political parties

Author

Brzezinski, Krzysztof, Zank, Horst, and Krol, Michal

Subjects
330, contest, issue divergence, issue convergence, competence, campaign, salience, uncertain demand, asymmetric costs, endogenous timing, quantity competition, elections
Abstract

This thesis investigates different aspects of competition under uncertainty using the tools of game theory. In Chapter 1, I consider a quantity oligopoly game. One of the firms is presented with an opportunity to commit to some output before the demand becomes known, but may add to it afterwards, then moving simultaneously with the rivals. I show that the more cost-efficient firm is more likely to behave like a Stackelberg leader, i.e. to produce the optimal Stackelberg leader quantity ex-ante and refrain from adding to it later, letting the rivals respond to its ex-ante output in the manner of Stackelberg followers. In Chapter 2, I study a model of an electoral contest. Two symmetric parties allocate their endowments to building platforms on various issues before the start of a campaign. Next, one of the issues becomes decisive in the course of the campaign with a commonly known probability. The outcome of the election depends on the difference in competence in this issue. I show that if the payoff functions are convex in this difference-the case of 'increasing returns to power'-parties differentiate each other by selecting different campaign issues. On the contrary, when the payoff functions are concave in this difference-the case of 'decreasing returns to power'-parties mimic each other by investing the same amounts into the same issues. Thus, incentives for selecting campaign issues depend critically on the shape of the payoff functions, which might be determined by (1) a non-linear technology transforming parties' investment in various topics into voters' perception of their competence, (2) or parties' inherent motivation for winning by a big margin due to parties' ideological convictions or rent-seeking, (3) or an electoral system giving winners or big parties a disproportionate advantage in the assigned number of seats, (4) or a relatively high extent of power given to the winning party once in office.

Published
2017

4. Tiny TTCN for IoT-Related Testing: That Shrinking Feeling

Author

Brzeziński, Krzysztof M., Kacprzyk, Janusz, Series Editor, Pal, Nikhil R., Advisory Editor, Bello Perez, Rafael, Advisory Editor, Corchado, Emilio S., Advisory Editor, Hagras, Hani, Advisory Editor, Kóczy, László T., Advisory Editor, Kreinovich, Vladik, Advisory Editor, Lin, Chin-Teng, Advisory Editor, Lu, Jie, Advisory Editor, Melin, Patricia, Advisory Editor, Nedjah, Nadia, Advisory Editor, Nguyen, Ngoc Thanh, Advisory Editor, Wang, Jun, Advisory Editor, Borzemski, Leszek, editor, Świątek, Jerzy, editor, and Wilimowska, Zofia, editor

Published
2019
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8. Analysis of Arabidopsis non-reference accessions reveals high diversity of metabolic gene clusters and discovers new candidate cluster members

Author

Marszalek-Zenczak, Malgorzata, Satyr, Anastasiia, Wojciechowski, Pawel, Zenczak, Michal, Sobieszczanska, Paula, Brzezinski, Krzysztof, Iefimenko, Tetiana, Figlerowicz, Marek, Zmienko, Agnieszka, Marszalek-Zenczak, Malgorzata, Satyr, Anastasiia, Wojciechowski, Pawel, Zenczak, Michal, Sobieszczanska, Paula, Brzezinski, Krzysztof, Iefimenko, Tetiana, Figlerowicz, Marek, and Zmienko, Agnieszka

Abstract

Metabolic gene clusters (MGCs) are groups of genes involved in a common biosynthetic pathway. They are frequently formed in dynamic chromosomal regions, which may lead to intraspecies variation and cause phenotypic diversity. We examined copy number variations (CNVs) in four Arabidopsis thaliana MGCs in over one thousand accessions with experimental and bioinformatic approaches. Tirucalladienol and marneral gene clusters showed little variation, and the latter was fixed in the population. Thalianol and especially arabidiol/baruol gene clusters displayed substantial diversity. The compact version of the thalianol gene cluster was predominant and more conserved than the noncontiguous version. In the arabidiol/baruol cluster, we found a large genomic insertion containing divergent duplicates of the CYP705A2 and BARS1 genes. The BARS1 paralog, which we named BARS2, encoded a novel oxidosqualene synthase. The expression of the entire arabidiol/baruol gene cluster was altered in the accessions with the duplication. Moreover, they presented different root growth dynamics and were associated with warmer climates compared to the reference-like accessions. In the entire genome, paired genes encoding terpene synthases and cytochrome P450 oxidases were more variable than their nonpaired counterparts. Our study highlights the role of dynamically evolving MGCs in plant adaptation and phenotypic diversity.

Published
2023

12. Intrusion Detection as Passive Testing: Linguistic Support with TTCN-3 (Extended Abstract)

Author

Brzezinski, Krzysztof M., Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, M. Hämmerli, Bernhard, editor, and Sommer, Robin, editor

Published
2007
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15. Pyrrolo[3,2-b]pyrrole-Based Covalent Triazine Framework: Three-dimensional Organization of Pores Using Nanostructural Spherical Carbon

Author

Hryniewicka, Agnieszka, primary, Breczko, Joanna, additional, Siemiaszko, Gabriela, additional, Papathanassiou, Anthony, additional, Góra-Marek, Kinga, additional, Tarach, Karolina, additional, Brzezinski, Krzysztof, additional, Ilnicka, Anna, additional, Terzyk, Artur, additional, Markiewicz, Karolina, additional, Echegoyen, Luis, additional, and Plonska-Brzezinska, Marta, additional

Published
2022
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23. Analysis of Arabidopsis nonreference accessions reveals high diversity of metabolic gene clusters and discovers new candidate cluster members.

Author

Marszalek-Zenczak, Malgorzata, Satyr, Anastasiia, Wojciechowski, Pawel, Zenczak, Michal, Sobieszczanska, Paula, Brzezinski, Krzysztof, Iefimenko, Tetiana, Figlerowicz, Marek, and Zmienko, Agnieszka

Abstract

Metabolic gene clusters (MGCs) are groups of genes involved in a common biosynthetic pathway. They are frequently formed in dynamic chromosomal regions, which may lead to intraspecies variation and cause phenotypic diversity. We examined copy number variations (CNVs) in four Arabidopsis thaliana MGCs in over one thousand accessions with experimental and bioinformatic approaches. Tirucalladienol and marneral gene clusters showed little variation, and the latter was fixed in the population. Thalianol and especially arabidiol/baruol gene clusters displayed substantial diversity. The compact version of the thalianol gene cluster was predominant and more conserved than the noncontiguous version. In the arabidiol/baruol cluster, we found a large genomic insertion containing divergent duplicates of the CYP705A2 and BARS1 genes. The BARS1 paralog, which we named BARS2, encoded a novel oxidosqualene synthase. The expression of the entire arabidiol/baruol gene cluster was altered in the accessions with the duplication. Moreover, they presented different root growth dynamics and were associated with warmer climates compared to the reference-like accessions. In the entire genome, paired genes encoding terpene synthases and cytochrome P450 oxidases were more variable than their nonpaired counterparts. Our study highlights the role of dynamically evolving MGCs in plant adaptation and phenotypic diversity. [ABSTRACT FROM AUTHOR]

Published
2023
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25. Monocarbonyl Analogs of Curcumin Based on the Pseudopelletierine Scaffold: Synthesis and Anti-Inflammatory Activity

Author

Pawelski, Damian, primary, Walewska, Alicja, additional, Ksiezak, Sylwia, additional, Sredzinski, Dariusz, additional, Radziwon, Piotr, additional, Moniuszko, Marcin, additional, Gandusekar, Ramesh, additional, Eljaszewicz, Andrzej, additional, Lazny, Ryszard, additional, Brzezinski, Krzysztof, additional, and Plonska-Brzezinska, Marta E., additional

Published
2021
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27. In vitro cytotoxicity and catalytic evaluation of dioxidovanadium(V) complexes in an azohydrazone ligand environment

Author

Mohanty, Monalisa, Maurya, Shailendra K., Banerjee, Atanu, Patra, Sushree Aradhana, Maurya, Mannar R., Crochet, Aurélien, Brzezinski, Krzysztof, and Dinda, Rupam

Abstract

Three new anionic dioxidovanadium(V) complexes (HNEt3)[VO2(L)1–3] (1–3) of tridentate binegative aroylhydrazone ligands containing the azobenzene moiety were synthesized and structurally characterized. The aroylhydrazone ligands (H2L1–3) were derived from the condensation of 5-(arylazo) salicylaldehyde derivatives with the corresponding aroyl hydrazides. All the synthesized ligands and metal complexes were successfully characterized by several physicochemical techniques, namely, elemental analysis, electrospray ionization mass spectrometry, spectroscopic methods (IR, UV-vis and NMR), and cyclic voltammetry. Single-crystal X-ray diffraction crystallography of 1–3 revealed five-coordinate geometry, where the ligand coordinates to the metal centre in a binegative tridentate O, N, O coordinating anion and two oxido-O atoms, resulting in distortion towards the square pyramidal structure. The complexes were further evaluated for their in vitro cytotoxicity against HeLa and HT-29 cancer cell lines. All the complexes manifested a cytotoxic potential that was found to be comparable with that of clinically referred drugs, while complex 3 proved to be the most cytotoxic among the three complexes for both cell lines, which may be due to the synergistic effect of the naphthyl substituent in the azohydrazone ligand environment coordinated to the vanadium metal. The synthesized complexes 1–3 were probed as catalysts for the oxidative bromination of thymol and styrene as a functional mimic of vanadium haloperoxidases (VHPOs). All the reactions provided high percentages of conversion (>90%) with a high turnover frequency (TOF) in the presence of the catalysts 1–3. In particular, for the oxidative bromination of thymol, the percentage of conversion and TOF were in the ranges of 98–99% and 5380–7173 (h−1), respectively. Besides, 3 bearing the naphthyl substituent showed the highest TOF among all the complexes for the oxidative bromination of both thymol and styrene.

Published
2020

32. New VIV, VIVO, VVO, and VVO2 Systems: Exploring their Interconversion in Solution, Protein Interactions, and Cytotoxicity

Author

Banerjee, Atanu, primary, Dash, Subhashree P., additional, Mohanty, Monalisa, additional, Sahu, Gurunath, additional, Sciortino, Giuseppe, additional, Garribba, Eugenio, additional, Carvalho, M. Fernanda N. N., additional, Marques, Fernanda, additional, Costa Pessoa, João, additional, Kaminsky, Werner, additional, Brzezinski, Krzysztof, additional, and Dinda, Rupam, additional

Published
2020
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34. Nanostructural catalyst: metallophthalocyanine and carbon nano-onion with enhanced visible-light photocatalytic activity towards organic pollutants

Author

Regulska, Elzbieta, primary, Olejnik, Piotr, additional, Zubyk, Halyna, additional, Czyrko-Horczak, Justyna, additional, Chaur, Manuel N., additional, Tomczykowa, Monika, additional, Butsyk, Olena, additional, Brzezinski, Krzysztof, additional, Echegoyen, Luis, additional, and Plonska-Brzezinska, Marta E., additional

Published
2020
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40. In vitro cytotoxicity and catalytic evaluation of dioxidovanadium(V) complexes in an azohydrazone ligand environment.

Author

Mohanty, Monalisa, Maurya, Shailendra K., Banerjee, Atanu, Patra, Sushree Aradhana, Maurya, Mannar R., Crochet, Aurélien, Brzezinski, Krzysztof, and Dinda, Rupam

Subjects
ELECTROSPRAY ionization mass spectrometry, THYMOL, VANADATES, X-ray crystallography
Abstract

Three new anionic dioxidovanadium(V) complexes (HNEt3)[VO2(L)1–3] (1–3) of tridentate binegative aroylhydrazone ligands containing the azobenzene moiety were synthesized and structurally characterized. The aroylhydrazone ligands (H2L1–3) were derived from the condensation of 5-(arylazo) salicylaldehyde derivatives with the corresponding aroyl hydrazides. All the synthesized ligands and metal complexes were successfully characterized by several physicochemical techniques, namely, elemental analysis, electrospray ionization mass spectrometry, spectroscopic methods (IR, UV-vis and NMR), and cyclic voltammetry. Single-crystal X-ray diffraction crystallography of 1–3 revealed five-coordinate geometry, where the ligand coordinates to the metal centre in a binegative tridentate O, N, O coordinating anion and two oxido-O atoms, resulting in distortion towards the square pyramidal structure. The complexes were further evaluated for their in vitro cytotoxicity against HeLa and HT-29 cancer cell lines. All the complexes manifested a cytotoxic potential that was found to be comparable with that of clinically referred drugs, while complex 3 proved to be the most cytotoxic among the three complexes for both cell lines, which may be due to the synergistic effect of the naphthyl substituent in the azohydrazone ligand environment coordinated to the vanadium metal. The synthesized complexes 1–3 were probed as catalysts for the oxidative bromination of thymol and styrene as a functional mimic of vanadium haloperoxidases (VHPOs). All the reactions provided high percentages of conversion (>90%) with a high turnover frequency (TOF) in the presence of the catalysts 1–3. In particular, for the oxidative bromination of thymol, the percentage of conversion and TOF were in the ranges of 98–99% and 5380–7173 (h−1), respectively. Besides, 3 bearing the naphthyl substituent showed the highest TOF among all the complexes for the oxidative bromination of both thymol and styrene. [ABSTRACT FROM AUTHOR]

Published
2019
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50. New VIV, VIVO, VVO, and VVO2Systems: Exploring their Interconversion in Solution, Protein Interactions, and Cytotoxicity

Author

Banerjee, Atanu, Dash, Subhashree P., Mohanty, Monalisa, Sahu, Gurunath, Sciortino, Giuseppe, Garribba, Eugenio, Carvalho, M. Fernanda N. N., Marques, Fernanda, Costa Pessoa, João, Kaminsky, Werner, Brzezinski, Krzysztof, and Dinda, Rupam

Abstract

The synthesis and characterization of one oxidoethoxidovanadium(V) [VVO(L1)(OEt)] (1) and two nonoxidovanadium(IV) complexes, [VIV(L2–3)2] (2and 3), with aroylhydrazone ligands incorporating naphthalene moieties, are reported. The synthesized oxido and nonoxido vanadium complexes are characterized by various physicochemical techniques, and their molecular structures are solved by single crystal X-ray diffraction (SC-XRD). This revealed that in 1the geometry around the vanadium atom corresponds to a distorted square pyramid, with a O4N coordination sphere, whereas that of the two nonoxido VIVcomplexes 2and 3corresponds to a distorted trigonal prismatic arrangement with a O4N2coordination sphere around each “bare” vanadium center. In aqueous solution, the VVO moiety of 1undergoes a change to VVO2species,yielding [VVO2(L1)]−(1′), while the nonoxido VIV-compounds 2and 3are partly converted into their corresponding VIVO complexes, [VIVO(L2–3)(H2O)] (2′and 3′). Interaction of these VVO2, VIVO, and VIVsystems with two model proteins, ubiquitin (Ub) and lysozyme (Lyz), is investigated through docking approaches, which suggest the potential binding sites: the interaction is covalent for species 2′and 3′, with the binding to Glu16, Glu18, and Asp21 for Ub, and His15 for Lyz, and it is noncovalent for species 1′, 2, and 3, with the surface residues of the proteins. The ligand precursors and complexes are also evaluated for their in vitroantiproliferative activity against ovarian (A2780) and prostate (PC3) human cancer cells and in normal fibroblasts (V79) to check the selectivity of the compounds for cancer cells.

Published
2020
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