Model for the oscillatory reaction between hydrogen peroxide and thiosulfate catalysed by copper(II) ions

1996 ◽  
Vol 92 (16) ◽  
pp. 2851-2855 ◽  
Author(s):  
Krisztina Kurin-Csörgei ◽  
Miklós Orbán ◽  
Gyula Rábai ◽  
Irving R. Epstein
Keyword(s):  
Hydrogen Peroxide ◽  
Oscillatory Reaction

APPLICABILITY OF BRAY-LIEBHAFSKY REACTION FOR CHEMICAL COMPUTING

2021 ◽  
Author(s):  
Željko Čupić ◽  
◽  
Ana I vanović Šašić ◽  
Stevan Maćešić ◽  
Slobodan Anić ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Numerical Simulations ◽  
Reaction System ◽  
Dynamic State ◽  
Oscillatory Reaction ◽  
Oscillatory Reactions ◽  
Dynamic States

The first discovered homogeneous oscillatory reaction was the Bray-Liebhafsky (BL) one, described in a paper published exactly 100 years ago. However, the applicability of oscillatory reactions in chemical computing was recently discovered. Here we intend to expose the native computing concept applied to intermittent states of the BL reaction, because we believe that this particular state may have some advantages. For this purpose, numerical simulations will be used based on the known model. Sequences of perturbations will be introduced by adding iodate (IO3-) and hydrogen peroxide (H2O2), separately, as well as in various combinations with one another. It will be shown that dynamic states obtained after perturbations with same species depend very much on the sequence in which these species were used in perturbations. Additionally, it will be shown that obtained dynamic states shift the system from chaotic intermittent dynamic state to different complex periodic states. Hence, the applicability of the BL reaction system in chemical computing was demonstrated.

scholarly journals Oscillatory reaction as a system detector for doped and undoped phosphate tungsten bronzes

2018 ◽  
Vol 72 (5) ◽  
pp. 275-283
Author(s):  
Tijana Maksimovic ◽  
Jelena Maksimovic ◽  
Ljubinka Joksovic ◽  
Zoran Nedic ◽  
Maja Pagnacco
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Dynamics ◽  
Organic Substrate ◽  
Linear Functions ◽  
Chemical System ◽  
Emission Spectrometry ◽  
Peroxo Complex ◽  
Oscillatory Reaction ◽  
Icp Oes ◽  
Oscillatory Period

Phosphate tungsten bronzes, obtained by thermal treatment, are insufficiently investigated bronzes and there is scarce literature data on their chemical behavior and structure. Due to high-sensitivity of the Briggs-Rauscher (BR) reaction to addition of different analytes, this oscillatory reaction presents a potentially important chemical system for investigation and characterization of phosphate-tungsten bronzes, doped and undoped. The reaction mixture for the oscillatory BR reaction typically consists of H2O2, HClO4, KIO3, Mn(II) (catalyst), and CH2(COOH)2 (malonic acid, as an organic substrate). This paper deals with phosphate tungsten bronzes (PWB) and lithium doped phosphate tungsten bronzes (LiPWB) and their effects on the Briggs-Rauscher reaction dynamics. It is shown that the addition of phosphate tungsten bronzes decreases the oscillatory period length in this reaction. Furthermore, the obtained results show that PWB has a stronger influence on the BR reaction dynamics then LiPWB. In both cases, the oscillatory period is a linear function of the added bronze mass. The obtained linear functions can be successfully used for determination of the unknown bronze mass. Furthermore, due to different slopes of these functions, the Briggs-Rauscher reaction can be used as a system-detector for lithium doped and undoped phosphate tungsten bronzes. In order to elucidate the mechanism of bronze action, the inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the total contents of K, Mn, W, Li. The aliquots of the above solution (i.e. CH2(COOH)2, MnSO4, HClO4, KIO3 but without H2O2) with the identical masses of PWB and LiPWB were examined. For the sake of comparison, contents of the metals in the solution without the bronze addition were measured, as well. Results obtained by the ICP-OES analysis show that the bronze structure is disturbed in the strong oxidizing environment (iodate in acidic solution) so that both, tungsten and lithium, leach into the BR solution. Accordingly, the proposed mechanism of the bronze action is probably by the reaction of tungsten ion with hydrogen-peroxide resulting in formation of a tungsten-peroxo complex. This complex is a stronger oxidizing agent then hydrogen peroxide itself. Thus, formation of the tungsten-peroxo complex potentially affects the kinetics of the Briggs-Rauscher reaction.

The Autocatalytic Oxidation of Iodine with Hydrogen Peroxide in Relation to the Bray-Liebhafsky Oscillatory Reaction

2006 ◽  
Vol 71 (1) ◽  
pp. 91-106 ◽  
Author(s):  
Anna Olexová ◽  
Marta Mrákavová ◽  
Milan Melicherčík ◽  
Ľudovít Treindl
Keyword(s):  
Hydrogen Peroxide ◽  
Singlet Oxygen ◽  
Induction Period ◽  
Surface Area ◽  
Iodine Concentration ◽  
Oh Radicals ◽  
Oscillatory Reaction ◽  
Subsequent Reaction ◽  
Low Concentrations ◽  
Autocatalytic Oxidation

The oxidation of iodine with hydrogen peroxide was studied spectrophotometrically and potentiometrically. At low concentrations of HClO4, after induction period (IP), the iodine concentration decreases sigmoidally and IP decreases with decreasing surface area of the solution interphase. We assume that •OH radicals are produced via the oxidation of iodide with H2O2 and, by their subsequent reaction with H2O2, the HO2• radicals are formed. By their disproportionation, 2 HO2•  ↔   H2O2 + 1O2, very reactive singlet oxygen is produced and the oxidation of iodine can start. The described experimental results are consistent with the Noyes-Treindl mechanism.

scholarly journals Kinetics of the Bray-Liebhafsky oscillatory reaction perturbed by polymer supported cobalt catalyst

2011 ◽  
Vol 43 (1) ◽  
pp. 55-62 ◽  
Author(s):  
J.P. Maksimovic ◽  
Z.D. Cupic ◽  
D. Loncarevic ◽  
N. Pejic ◽  
D. Vasiljevic-Radovic ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Data ◽  
Cobalt Catalyst ◽  
Batch Reactor ◽  
Oscillatory Reaction ◽  
Hydrogen Peroxide Decomposition ◽  
Co Catalyst ◽  
Peroxide Decomposition ◽  
Polymer Supported ◽  
Kinetics Of

The Bray-Liebhafsky (BL) oscillatory reaction generated in the batch reactor at 62- 68 oC was perturbed by cobalt(II)-nitrate, supported on the macroreticular copolymer of poly-4-vinylpyridine with divinylbenzene (Co-PVPDVB). The kinetic data was analyzed of the complex pathways of the hydrogen peroxide decomposition in the examined BL reaction. The obtained results confirm that the kinetics of the BL reaction in the presence Co-PVPDVB comes partially from the Co-catalyst and partially from the macroreticular copolymer support.

Peroxidase Localization in Hartmanella Trophozoites

1971 ◽  
Vol 29 ◽  
pp. 346-347 ◽  
Author(s):  
George E. Childs ◽  
Joseph H. Miller
Keyword(s):  
Hydrogen Peroxide ◽  
Ultrastructural Localization ◽  
Pathogenic Strain ◽  
Oxidative Enzymes ◽  
Differential Centrifugation ◽  
Electron Microscopic ◽  
Microscopic Studies ◽  
The Subject ◽  
Axenic Cultures

Biochemical and differential centrifugation studies have demonstrated that the oxidative enzymes of Acanthamoeba sp. are localized in mitochondria and peroxisomes (microbodies). Although hartmanellid amoebae have been the subject of several electron microscopic studies, peroxisomes have not been described from these organisms or other protozoa. Cytochemical tests employing diaminobenzidine-tetra HCl (DAB) and hydrogen peroxide were used for the ultrastructural localization of peroxidases of trophozoites of Hartmanella sp. (A-l, Culbertson), a pathogenic strain grown in axenic cultures of trypticase soy broth.

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light >600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

Protective effect of chitooligosaccharides on hydrogen peroxide-induced PC-12 cells death by inhibition of oxidative damage

2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Xueling Dai ◽  
Ping Chang ◽  
Ke Xu ◽  
Changjun Lin ◽  
Hanchang Huang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Damage ◽  
Protective Effect ◽  
Pc 12 Cells ◽  
Cells Death

Signal-regulated oxidation of proteins via MICAL

2020 ◽  
Vol 48 (2) ◽  
pp. 613-620
Author(s):  
Clara Ortegón Salas ◽  
Katharina Schneider ◽  
Christopher Horst Lillig ◽  
Manuela Gellert
Keyword(s):  
Signal Transduction ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Redox Regulation ◽  
Signal Transduction Pathways ◽  
Cellular Functions ◽  
Intracellular Signals ◽  
Amino Acid Side Chains ◽  
Specific Receptors ◽  
Sulfur Containing

Processing of and responding to various signals is an essential cellular function that influences survival, homeostasis, development, and cell death. Extra- or intracellular signals are perceived via specific receptors and transduced in a particular signalling pathway that results in a precise response. Reversible post-translational redox modifications of cysteinyl and methionyl residues have been characterised in countless signal transduction pathways. Due to the low reactivity of most sulfur-containing amino acid side chains with hydrogen peroxide, for instance, and also to ensure specificity, redox signalling requires catalysis, just like phosphorylation signalling requires kinases and phosphatases. While reducing enzymes of both cysteinyl- and methionyl-derivates have been characterised in great detail before, the discovery and characterisation of MICAL proteins evinced the first examples of specific oxidases in signal transduction. This article provides an overview of the functions of MICAL proteins in the redox regulation of cellular functions.

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