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1.
J Obes ; 2023: 7392513, 2023.
Article in English | MEDLINE | ID: mdl-37901192

ABSTRACT

Obesity develops largely due to genetic factors, with the genetic polymorphism of lipid metabolism enzymes being of particular importance. However, it is still unclear how the genetic variants of one of the key enzymes in lipid transport, lipoprotein lipase (LPL), are associated with the endocrine function of mesenchymal tissues in obesity. The current study was aimed at the investigation of the LPL rs328 gene variant association with adipokines and myokines levels, as well as lipid metabolism indices in the blood of children and adolescents of both genders with obesity. We found that LPL polymorphism rs328 is not characterized by the differences in the levels of hormones, adipokines, and myokines and in the blood of healthy children and adolescents; however, it significantly affects these indices during obesity in gender-dependent manner. The shifts in hormones, adipokines, and myokines manifest mostly in the obese individuals with Ser447Ser genotype rather than with 447Ter genotype. Obese boys homozygous for Ser447Ser have more elevated leptin levels than girls. They also demonstrate lower adiponectin, apelin, prolactin, and osteocrine levels than those in obese girls with the same genotype. The gender-based differences are less pronounced in individuals with 447Ter genotype than in the homozygotes for 447Ser. Thus, we conclude that the polymorphism rs328 of the lipoprotein lipase gene is accompanied by the changes in hormones, adipokines, and myokines levels in the blood of children and adolescents with obesity in gender-dependent manner.


Subject(s)
Lipoprotein Lipase , Pediatric Obesity , Adolescent , Child , Female , Humans , Male , Adipokines/blood , Adiponectin , Genotype , Lipoprotein Lipase/genetics , Pediatric Obesity/genetics
2.
Genet Test Mol Biomarkers ; 25(6): 419-425, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34152846

ABSTRACT

Background: Obesity is one of the most common metabolic disorders in the world, which develops due to an imbalance in energy consumption and expenditure, and both genetic and environmental factors are of great importance. We investigated the potential interactions of single nucleotide polymorphisms that might contribute to the development of polygenic obesity in children. Objective: The study involved 367 children and adolescents of both sexes aged from 4 to 18 years. The control group (normal weight) and the overweight groups included 65 and 302 children respectively. Methods: DNA for analysis was isolated from peripheral blood lymphocytes, then allelic variants rs99305069 of the FTO gene (chr16:53786615), Gln192Arg of the PON1 gene (chr7: 95308134), -250G>A of the LIPC gene (chr15: 58431740), and Ser447Ter of the LPL gene (chr8:19957678) were studied using the SNP-Express reagent kit. The results of allelic interactions were analyzed using the multifactor dimensionality reduction method. Results and Discussion: Among overweight children, the distribution of genotype and allele frequencies for the studied single nucleotide polymorphisms of the four genes corresponded to those of the control group (p > 0.05). It was found that in obese children SerSer homozygotes at the Ser447Ter polymorphism of the LPL gene, had serum triglyceride (TG) levels 2.3 times higher than in children with the same genotype from the control group. In overweight Ser447Ter heterozygotes (p < 0.0001), the TG level exceeded the control values by only 13% (p = 0.044). A two-locus genotype FTO AT/LPL SerTer, was associated with a reduced risk of childhood obesity.


Subject(s)
Genetic Predisposition to Disease , Lipid Metabolism/genetics , Pediatric Obesity/genetics , Adolescent , Body Mass Index , Case-Control Studies , Child , Child, Preschool , Female , Gene Frequency , Humans , Male , Pediatric Obesity/diagnosis , Pediatric Obesity/epidemiology , Polymorphism, Single Nucleotide , Risk Assessment/methods
3.
J Reprod Infertil ; 22(2): 92-102, 2021.
Article in English | MEDLINE | ID: mdl-34041005

ABSTRACT

BACKGROUND: The purpose of this study was to investigate the association between IL-4 -589C>T, IL-6 -174G>C, IL-1ß -31T>C and IL-1ß -511C>T genes polymorphism with high concentrations of human papillomavirus (HPV), and the influence of gene-gene interactions on persistent human papillomavirus infection. METHODS: In this study, 101 infected women with high HPV viral load and 93 healthy women were involved in a case-control study. Genotyping of SNPs for IL-4 -589C>T, IL-6 -174G>C, IL-1ß -31T>C and IL-1ß -511C>T genes was carried out by allele-specific PCR. Quantitative analysis of HPV-DNA was performed by Amplisens HPV HCR genotype-titer software. Gene-gene interactions were analyzed using multifactor dimensionality reduction (MDR) algorithm. Haplotype interactions were analyzed by HaploView 4.2 tool. RESULTS: The study of single individual SNPs in promoters of IL-4 -589C>T, IL-6 -174G>C and IL-1ß -31T>C genes did not reveal statistically significant difference in genotypes and allele frequencies among women with high HPV viral load and control group. The frequency of -511T allele and TT genotype of the IL-1ß gene in case group was significantly higher than the one in control group (OR=1.71, p=0.012 and OR=2.02, p=0.046, respectively). Haplotype analysis revealed that -511C/-31T haplotype for IL-1ß gene is significantly less common among women with high HPV viral load (p=0.018). CONCLUSION: The haplotype -511C/-31T for IL-1ß gene is associated with a protective effect against increasing HPV viral load. The frequencies of -511T allele and -511TT genotype of the IL-1ß -511C>T were significantly higher among women with HPV in comparison to control group.

4.
J Reprod Infertil ; 19(4): 219-228, 2018.
Article in English | MEDLINE | ID: mdl-30746337

ABSTRACT

BACKGROUND: The study was aimed to investigate the association of VEGFA gene polymorphic variants -2578C>A (rs699947) and -634G>C (rs2010963) and TGFB1 gene 915G>C (rs1800471) and gene expression level with miscarriage in the first trimester. METHODS: 288 women with different courses of pregnancy and 61 chorionic tissue samples were involved in case-control study. Allele-specific polymerase chain reaction in real time was used for genotyping. Next, gene-gene interactions were analyzed using the multifactor dimensionality reduction method. VEGFA and TGFB1 genes expression levels were determined by RT-PCR. RESULTS: It was found that SNP rs699947 was associated with the miscarriage risk change (p=0.05). The CC genotype was associated with reduced risk of abortion in the first trimester, and the CA genotype with increased risk. Genotypes VEGFA -2578CC/VEGFA -634CG, VEGFA -2578AA/VEGFA -634CG,and VEGFA -2578CC/ VEGFA -634CG/TGFB1 936CC were associated with lowered risk of miscarriage in the first trimester. mRNA level of TGFB1 was significantly higher in decidual tissue compared to chorionic tissue in normally progressing pregnancy (p=0.003). VEGFA gene expression level was directly correlated with the TGFB1 mRNA level (R=0.60; p=0.038). In pregnancy loss, an inverse relationship was observed (R=-0.76; p=0.028). CONCLUSION: The SNP rs699947 is associated with pregnancy loss in the first trimester. The MDR analysis data showed the significant relationship between VEGFA and TGFB1 genes in two-locus and three-locus models. A change in the ratio of the concentrations of growth factors can disrupt the processes of cell division, apoptosis and angiogenesis processes.

5.
Genet. mol. biol ; 40(2): 515-524, Apr.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-892411

ABSTRACT

Abstract Pathway activity assessment-based approaches are becoming highly influential in various fields of biology and medicine. However, these approaches mostly rely on analysis of mRNA expression, and total mRNA from a given locus is measured in the majority of cases. Notably, a significant portion of protein-coding genes produces more than one transcript. This biological fact is responsible for significant noise when changes in total mRNA transcription of a single gene are analyzed. The NFE2L2/AP-1 pathway is an attractive target for biomedical applications. To date, there is a lack of data regarding the agreement in expression of even classical target genes of this pathway. In the present paper we analyzed whether transcript variants of GPX2, NQO1 and SQSTM1 were characterized by individual features of expression when HeLa cells were exposed to pro-oxidative stimulation with hydrogen peroxide. We found that all the transcripts (10 in total) appeared to be significantly individually regulated under the conditions tested. We conclude that individual transcripts, rather than total mRNA, are best markers of pathway activation. We also discuss here some biological roles of individual transcript regulation.

6.
Genet Mol Biol ; 40(2): 515-524, 2017.
Article in English | MEDLINE | ID: mdl-28558074

ABSTRACT

Pathway activity assessment-based approaches are becoming highly influential in various fields of biology and medicine. However, these approaches mostly rely on analysis of mRNA expression, and total mRNA from a given locus is measured in the majority of cases. Notably, a significant portion of protein-coding genes produces more than one transcript. This biological fact is responsible for significant noise when changes in total mRNA transcription of a single gene are analyzed. The NFE2L2/AP-1 pathway is an attractive target for biomedical applications. To date, there is a lack of data regarding the agreement in expression of even classical target genes of this pathway. In the present paper we analyzed whether transcript variants of GPX2, NQO1 and SQSTM1 were characterized by individual features of expression when HeLa cells were exposed to pro-oxidative stimulation with hydrogen peroxide. We found that all the transcripts (10 in total) appeared to be significantly individually regulated under the conditions tested. We conclude that individual transcripts, rather than total mRNA, are best markers of pathway activation. We also discuss here some biological roles of individual transcript regulation.

7.
Anal Chem ; 88(9): 4724-32, 2016 05 03.
Article in English | MEDLINE | ID: mdl-27041344

ABSTRACT

Estimation of thermodynamic and kinetic parameters in electrochemical studies is usually undertaken via comparison of the experimental results with theory based on a model that mimics the experiment. The present study examines the credibility of transient d.c. and a.c. voltammetric theory-experiment comparisons for recovery of the parameters needed to model the ubiquitous mechanism when an electron transfer (E) reaction is followed by a chemical (C) step in the EC process ([Formula: see text]). The data analysis has been undertaken using optimization methods facilitated in some cases by grid computing. These techniques have been applied to the simulated (5% noise added) and experimental (reduction of trans-stilbene) voltammograms to assess the capabilities of parameter recovery of E(0) (reversible potential for the E step), k(0) (heterogeneous electron transfer rate constant at E(0)), α (charge transfer coefficient for the E step), and k(f) and k(b) (forward and backward rate constants for the C step) under different kinetic regimes. The advantages provided by the use of a.c. instead of d.c. voltammetry and data optimization methods over heuristic approaches to "experiment"-theory comparisons are discussed, as are the limitations in the efficient recovery of a unique set of parameters for the EC mechanism. In the particular experimental case examined herein, results for the protonation of the electrochemically generated stilbene dianion demonstrate that, notwithstanding significant advances in experiment and theory of voltammetric analysis, reliable recovery of the parameters for the EC mechanism with a fast chemical process remains a stiff problem.

8.
Inorg Chem ; 54(9): 4292-302, 2015 May 04.
Article in English | MEDLINE | ID: mdl-25898208

ABSTRACT

A closo-type 11-vertex osmaborane [1-(η(6)-pcym)-1-OsB10H10] (pcym = para-cymene) has been synthesized and characterized by single-crystal X-ray diffraction and elemental analysis, as well as by (11)B and (1)H NMR, UV-visible, and mass spectrometry. The redox chemistry has been probed by dc and Fourier transformed ac voltammetry and bulk reductive electrolysis in CH3CN (0.10 M (n-Bu)4NPF6) and by voltammetry in the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide (Pyrr1,4-NTf2), which allows the oxidative chemistry of the osmaborane to be studied. A single-crystal X-ray diffraction analysis has shown that [1-(η(6)-pcym)-1-OsB10H10] is isostructural with other metallaborane compounds of this type. In CH3CN (0.10 M (n-Bu)4NPF6), [1-(η(6)-pcym)-1-OsB10H10] undergoes two well-resolved one-electron reduction processes with reversible potentials separated by ca. 0.63-0.64 V. Analysis based on a comparison of experimental and simulated ac voltammetric data shows that the heterogeneous electron transfer rate constant (k(0)) for the first reduction process is larger than that for the second step at GC, Pt, and Au electrodes. k(0) values for both processes are also larger at GC than metal electrodes and depend on the electrode pretreatment, implying that reductions involve specific interaction with the electrode surface. EPR spectra derived from the product formed by one-electron reduction of [1-(η(6)-pcym)-1-OsB10H10] in CH3CN (0.10 M (n-Bu)4NPF6) and electron orbital data derived from the DFT calculations are used to establish that the formal oxidation state of the metal center of the original unreduced compound is Os(II). On this basis it is concluded that the metal atom in [1-(η(6)-pcym)-1-OsB10H10] and related metallaboranes makes a 3-orbital 2-electron contribution to the borane cluster. Oxidation of [1-(η(6)-pcym)-1-OsB10H10] coupled to fast chemical transformation was observed at 1.6 V vs ferrocene(0/+) in Pyrr1,4-NTf2. A reaction scheme for the oxidation involving formation of [1-(η(6)-pcym)-1-OsB10H10](+), which rearranges to an unknown electroactive derivative, is proposed, and simulations of the voltammograms are provided.

9.
Anal Chem ; 86(16): 8408-17, 2014 Aug 19.
Article in English | MEDLINE | ID: mdl-25047798

ABSTRACT

Many electrode processes that approach the "reversible" (infinitely fast) limit under voltammetric conditions have been inappropriately analyzed by comparison of experimental data and theory derived from the "quasi-reversible" model. Simulations based on "reversible" and "quasi-reversible" models have been fitted to an extensive series of a.c. voltammetric experiments undertaken at macrodisk glassy carbon (GC) electrodes for oxidation of ferrocene (Fc(0/+)) in CH3CN (0.10 M (n-Bu)4NPF6) and reduction of [Ru(NH3)6](3+) and [Fe(CN)6](3-) in 1 M KCl aqueous electrolyte. The confidence with which parameters such as standard formal potential (E(0)), heterogeneous electron transfer rate constant at E(0) (k(0)), charge transfer coefficient (α), uncompensated resistance (Ru), and double layer capacitance (CDL) can be reported using the "quasi-reversible" model has been assessed using bootstrapping and parameter sweep (contour plot) techniques. Underparameterization, such as that which occurs when modeling CDL with a potential independent value, results in a less than optimal level of experiment-theory agreement. Overparameterization may improve the agreement but easily results in generation of physically meaningful but incorrect values of the recovered parameters, as is the case with the very fast Fc(0/+) and [Ru(NH3)6](3+/2+) processes. In summary, for fast electrode kinetics approaching the "reversible" limit, it is recommended that the "reversible" model be used for theory-experiment comparisons with only E(0), Ru, and CDL being quantified and a lower limit of k(0) being reported; e.g., k(0) ≥ 9 cm s(-1) for the Fc(0/+) process.

10.
J Phys Chem B ; 118(24): 6839-49, 2014 Jun 19.
Article in English | MEDLINE | ID: mdl-24842567

ABSTRACT

Detailed electrochemical studies have been undertaken on molecular aggregation of the organic semiconductor 7,14-bis((triisopropylsilyl)-ethynyl)dibenzo[b,def]chrysene (TIPS-DBC), which is used as an electron donor material in organic solar cells. Intermolecular association of neutral TIPS-DBC molecules was established by using (1)H NMR spectroscopy as well as by the pronounced dependence of the color of TIPS-DBC solutions on concentration. Diffusion limited current data provided by near steady-state voltammetry also reveal aggregation. Furthermore, variation of concentration produces large changes in shapes of transient DC and Fourier transformed AC (FTAC) voltammograms for oxidation of TIPS-DBC in dichloromethane. Subtle effects of molecular aggregation on the reduction of TIPS-DBC are also revealed by the highly sensitive FTAC voltammetric method. Simulations of FTAC voltammetric data provide estimates of the kinetic and thermodynamic parameters associated with oxidation and reduction of TIPS-DBC. Significantly, aggregation of TIPS-DBC facilitates both one-electron oxidation and reduction by shifting the reversible potentials to less and more positive values, respectively. EPR spectroscopy is used to establish the identity of one-electron oxidized and reduced forms of TIPS-DBC. Implications of molecular aggregation on the HOMO energy level in solution are considered with respect to efficiency of organic photovoltaic devices utilizing TIPS-DBC as an electron donor material.

11.
Langmuir ; 30(11): 3264-73, 2014 Mar 25.
Article in English | MEDLINE | ID: mdl-24571209

ABSTRACT

New insights into electrochemical kinetics of the flavin adenine dinucleotide (FAD) redox center of glucose-oxidase (GlcOx) immobilized on reduced graphene oxide (rGO), single- and multiwalled carbon nanotubes (SW and MWCNT), and combinations of rGO and CNTs have been gained by application of Fourier transformed AC voltammetry (FTACV) and simulations based on a range of models. A satisfactory level of agreement between experiment and theory, and hence establishment of the best model to describe the redox chemistry of FAD, was achieved with the aid of automated e-science tools. Although still not perfect, use of Marcus theory with a very low reorganization energy (≤0.3 eV) best mimics the experimental FTACV data, which suggests that the process is gated as also deduced from analysis of FTACV data obtained at different frequencies. Failure of the simplest models to fully describe the electrode kinetics of the redox center of GlcOx, including those based on the widely employed Laviron theory is demonstrated, as is substantial kinetic heterogeneity of FAD species. Use of a SWCNT support amplifies the kinetic heterogeneity, while a combination of rGO and MWCNT provides a more favorable environment for fast communication between FAD and the electrode.


Subject(s)
Carbon/chemistry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Flavin-Adenine Dinucleotide/metabolism , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Aspergillus niger/enzymology , Electrochemistry , Electrodes , Flavin-Adenine Dinucleotide/chemistry , Kinetics , Oxidation-Reduction
12.
Mol Diagn Ther ; 18(3): 355-69, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24504888

ABSTRACT

BACKGROUND AND OBJECTIVES: Oxidative status-based interactomic profiling is a promising approach for fundamental integrative cell biology, diagnostics, and therapy. However, this approach has been neither utilized as a method nor tested as a tool. Thus, we aimed (1) to develop an oxidative status pathway state assessment-based analytical procedure relying on NFE2L2/AP1 pathway evaluation, and (2) to preliminarily assess its responsiveness, performance and diagnostic properties when applied to deciphering stress conditions of the academic examination period and academic term. These conditions were chosen as those representing a common model of mild, everyday-life stressors causing shifts in oxidative status. METHODS: To meet the aim of the study, we performed a repetitive-measurements study collating gene expression of NFE2L2/AP1 pathway targets and controllers under the two stress conditions using semi-quantitative reverse transcription-polymerase chain reaction. RESULTS: Surprisingly, even with some sensitivity limitations of the methods employed, a pathway state analysis approach based on a multiple target-to-controller ratio calculation was highly responsive and yielded very high receiver operating characteristics in deciphering the model stress conditions. CONCLUSION: Although further testing of the approach is required, the interactomic pathway activation assaying concept was preliminarily experimentally proven to be a highly promising clinical diagnostic tool that may easily be adapted for current tasks.


Subject(s)
NF-E2-Related Factor 2/genetics , Oxidative Stress , Signal Transduction , Stress, Psychological/genetics , Transcription Factor AP-1/genetics , Biomarkers/analysis , Biomarkers/blood , Female , Gene Expression Profiling , Humans , Young Adult
13.
Anal Chem ; 85(24): 11780-7, 2013 Dec 17.
Article in English | MEDLINE | ID: mdl-24160752

ABSTRACT

Fully automated and computer assisted heuristic data analysis approaches have been applied to a series of AC voltammetric experiments undertaken on the [Fe(CN)6](3-/4-) process at a glassy carbon electrode in 3 M KCl aqueous electrolyte. The recovered parameters in all forms of data analysis encompass E(0) (reversible potential), k(0) (heterogeneous charge transfer rate constant at E(0)), α (charge transfer coefficient), Ru (uncompensated resistance), and Cdl (double layer capacitance). The automated method of analysis employed time domain optimization and Bayesian statistics. This and all other methods assumed the Butler-Volmer model applies for electron transfer kinetics, planar diffusion for mass transport, Ohm's Law for Ru, and a potential-independent Cdl model. Heuristic approaches utilize combinations of Fourier Transform filtering, sensitivity analysis, and simplex-based forms of optimization applied to resolved AC harmonics and rely on experimenter experience to assist in experiment-theory comparisons. Remarkable consistency of parameter evaluation was achieved, although the fully automated time domain method provided consistently higher α values than those based on frequency domain data analysis. The origin of this difference is that the implemented fully automated method requires a perfect model for the double layer capacitance. In contrast, the importance of imperfections in the double layer model is minimized when analysis is performed in the frequency domain. Substantial variation in k(0) values was found by analysis of the 10 data sets for this highly surface-sensitive pathologically variable [Fe(CN)6](3-/4-) process, but remarkably, all fit the quasi-reversible model satisfactorily.

14.
Philos Trans A Math Phys Eng Sci ; 369(1949): 3336-52, 2011 Aug 28.
Article in English | MEDLINE | ID: mdl-21768143

ABSTRACT

As in many scientific disciplines, modern chemistry involves a mix of experimentation and computer-supported theory. Historically, these skills have been provided by different groups, and range from traditional 'wet' laboratory science to advanced numerical simulation. Increasingly, progress is made by global collaborations, in which new theory may be developed in one part of the world and applied and tested in the laboratory elsewhere. e-Science, or cyber-infrastructure, underpins such collaborations by providing a unified platform for accessing scientific instruments, computers and data archives, and collaboration tools. In this paper we discuss the application of advanced e-Science software tools to electrochemistry research performed in three different laboratories--two at Monash University in Australia and one at the University of Oxford in the UK. We show that software tools that were originally developed for a range of application domains can be applied to electrochemical problems, in particular Fourier voltammetry. Moreover, we show that, by replacing ad-hoc manual processes with e-Science tools, we obtain more accurate solutions automatically.

15.
J Phys Chem A ; 115(24): 6493-502, 2011 Jun 23.
Article in English | MEDLINE | ID: mdl-21612272

ABSTRACT

Heterogeneous charge transfer rate constants (k°) for the oxidation of ferrocene, Fc (k° = 0.21 cm s(-1) at 20 °C), and the reduction of the cobaltocenium cation, Cc(+) (k° = 0.12 cm s(-1) at 18 °C), in CH(2)Cl(2) (0.5 M Bu(4)NPF(6)) at a glassy carbon (GC) electrode were determined as a function of temperature using the higher harmonic components available in Fourier transformed large amplitude ac voltammetry. The measured k° values lie at the upper end of the analytically useful range available for the acquisition of meaningful kinetic data for these very fast (i.e., close to reversible) processes. Measurements of the kinetics are facilitated by the ac technique because contributions resulting from uncompensated resistance and slow electrode kinetics, both of which also vary with temperature, can be distinguished via their different contributions to individual harmonics. Values of k° measured over the temperature range of -18 to +20 °C for the Fc(0/+) and Cc(+/0) processes gave linear Arrhenius plots yielding free energies of activation (ΔG(‡)) estimates of 17.0 and 18.0 kJ mol(-1), respectively, in excellent agreement with theoretical values derived from Marcus theory. An analogous temperature dependence is indicated in a study of the Fc(0/+) process in acetonitrile (0.1 M Bu(4)NPF(6)), but the greater k° value evident makes the temperature dependence of these parameters more difficult to quantify as departures from reversibility are minimal, even in the higher harmonics.

16.
Anal Chem ; 83(5): 1791-9, 2011 Mar 01.
Article in English | MEDLINE | ID: mdl-21302902

ABSTRACT

Sinusoidal large amplitude ac voltammetric techniques gene-rate very large data sets. When analyzed in the frequency domain, using a Fourier transform (FT)-band filtering- inverse FT sequence, the data may be resolved into the aperiodic dc, fundamental, second, and higher order ac harmonics. Each of these components exhibit a different level of sensitivity to electrode kinetics, uncompensated resistance and capacitance. Detailed simulations illustrate how the heuristic approach for evaluation of each data subset may be implemented and exploited in the assessment of the electrode kinetics for the fast Fc [symbol:see text] Fc(+) + e (Fc = ferrocene) oxidation process at a glassy carbon macrodisk electrode. The simulations presented in this study are based on the Butler-Volmer model and incorporate consideration of the uncompensated resistance (R(u)), double-layer capacitance (C(dl)), rate constant (k(0)), and charge transfer coefficient (α). Error analysis of the heuristically evaluated simulation-experiment comparison is used to assist in establishing the best fit of data for each harmonic. The result of the heuristic pattern recognition type approach for analysis of the oxidation of ferrocene (0.499, 0.999, and 5.00 mM) at a glassy carbon macrodisk electrode in acetonitrile (0.1 M Bu(4)NPF(6)) implies that k(0) ≥ 0.25 cm s(-1) on the basis of analysis of the first 4 harmonics and plausibly lies in the range of 0.25-0.5 cm s(-1) with α = 0.25-0.75 when analysis of the next four harmonics is undertaken. The k(0) value is significantly faster then indicated in most literature reports based on use of dc cyclic voltammetry under transient conditions at glassy carbon macrodisk electrode. The data analysis with a sinusoidal amplitude of 80 mV is conducted at very low frequency experiments of 9 Hz to minimize contribution from electrode heterogeneity, frequency dispersion, and adsorption, all of which can complicate the response for the oxidation of Fc in acetonitrile at a glassy carbon electrode.

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