Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (3)

Search Parameters:
Authors = Lech Chmurzynski

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
12 pages, 3091 KB  
Article
A Novel Biosensor for Evaluation of Apoptotic or Necrotic Effects of Nitrogen Dioxide during Acute Pancreatitis in Rat
by Dagmara Jacewicz, Aleksandra Dabrowska, Dariusz Wyrzykowski, Joanna Pranczk, Michal Wozniak, Jolanta Kubasik-Juraniec, Narcyz Knap, Kamila Siedlecka, Alexander J. Neuwelt and Lech Chmurzynski
Sensors 2010, 10(1), 280-291; https://doi.org/10.3390/s100100280 - 30 Dec 2009
Cited by 16 | Viewed by 10171
Abstract
The direct and accurate estimation of nitric dioxide levels is an extremely laborious and technically demanding procedure in the molecular diagnostics of inflammatory processes. The aim of this work is to demonstrate that a stop-flow technique utilizing a specific spectroscopic biosensor can be [...] Read more.
The direct and accurate estimation of nitric dioxide levels is an extremely laborious and technically demanding procedure in the molecular diagnostics of inflammatory processes. The aim of this work is to demonstrate that a stop-flow technique utilizing a specific spectroscopic biosensor can be used for detection of nanomolar quantities of NO2 in biological milieu. The use of novel compound cis-[Cr(C2O4)(AaraNH2)(OH2)2]+ increases NO2 estimation accuracy by slowing down the rate of NO2 uptake. In this study, an animal model of pancreatitis, where nitrosative stress is induced by either 3g/kg bw or 1.5 g/kg bw dose of L-arginine, was used. Biochemical parameters and morphological characteristics of acute pancreatitis were monitored, specifically assessing pancreatic acinar cell death mode, NO2 generation and cellular glutathione level. The severity of the process correlated positively with NO2 levels in pancreatic acinar cell cytosol samples, and negatively with cellular glutathione levels. Full article
(This article belongs to the Section Biosensors)
►▼ Show Figures

10 pages, 30 KB  
Article
A Study of Acid-Base Equilibria in Acetonitrile Systems of 2-Halo(Cl,Br,I)-4-nitropicoline(3,5,6) N-oxides
by Ewa Kaczmarczyk, Aniela Puszko, Jadwiga Lorenc and Lech Chmurzynski
Molecules 1999, 4(4), 94-103; https://doi.org/10.3390/40400094 - 29 Mar 1999
Cited by 5 | Viewed by 9863
Abstract
An attempt has been made to determine potentiometrically (1) acid dissociation constants of cations obtained by protonation of nine trisubstituted pyridine N-oxides, namely 2-halo(Cl, Br and I)-4-nitropicoline N-oxides with the methyl group at positions 3, 5, and 6, as well as (2) the [...] Read more.
An attempt has been made to determine potentiometrically (1) acid dissociation constants of cations obtained by protonation of nine trisubstituted pyridine N-oxides, namely 2-halo(Cl, Br and I)-4-nitropicoline N-oxides with the methyl group at positions 3, 5, and 6, as well as (2) the cationic homoconjugation constants of these cationic acids with conjugated N-oxides in acetonitrile. On the basis of the substitution effect, variations of the acid dissociation constants of the trisubstituted pyridine N-oxide cations are discussed. The determined pKa values of the protonated 2-halo-4-nitropicoline N-oxides are compared with the previously determined equilibrium constants of the cationic acids conjugated with the mono- and disubstituted pyridine N-oxides in acetonitrile. Further, based on the pKa values of the protonated 2-halo-4-nitropicoline N-oxides in acetonitrile, supplemented with correlations between pKa’s of the protonated mono- and disubstituted pyridine N-oxides in acetonitrile and water, the pKa's of the acids conjugated with the trisubstituted N-oxides studied in aqueous solutions have been estimated. Moreover, it has been concluded that the cationic homoconjugation constants cannot be determined by potentiometric titration in acetonitrile solutions of the 2-halo-4-nitropicoline N-oxide systems. Full article
7 pages, 31 KB  
Article
Experimental Studies on the UV-Spectra of Several Substituted Pyridine N-Oxides and Conjugated Cationic Acids in Acetonitrile
by Lech Chmurzynski
Molecules 1997, 2(11), 169-175; https://doi.org/10.3390/21100169 - 15 Nov 1997
Cited by 4 | Viewed by 7711
Abstract
The ultraviolet spectra of heterocyclic N-oxides of pyridine N-oxide series and the conjugated cationic acids (simple cations of protonated N-oxides) in acetonitrile as the representative of polar aprotic solvents, were determined. The obtained spectra of N-oxides studied (mainly tri-substituted pyridine N-oxides) and their [...] Read more.
The ultraviolet spectra of heterocyclic N-oxides of pyridine N-oxide series and the conjugated cationic acids (simple cations of protonated N-oxides) in acetonitrile as the representative of polar aprotic solvents, were determined. The obtained spectra of N-oxides studied (mainly tri-substituted pyridine N-oxides) and their cations obtained by the protonation of free N-oxides by the excess of perchloric acid, have been collected and discussed. Taking into account the spectroscopic results, a scheme of acid-base equilibria in polar aprotic solvents has been discussed. The influence of the traces of water on acid-base equilibria in nonaqueous media has been stressed. Full article
Back to TopTop