Chemistry Commons^™

Effect Of Quercetin, Genistein And Kaempferol On Glutathione And Glutathione-Redox Cycle Enzymes In 3t3-L1 Preadipocytes, William Y. Boadi, Paul K. Amartey, Andrew Lo

Chemistry Faculty Research

Context and objective: Many studies have shown that cellular redox potential is largely determined by glutathione (GSH), which accounts for more than 90% of cellular nonprotein thiols. The aim of this study was to delineate the effect of three flavonoids – namely, quercetin, kaempferol and genistein – and exogenous GSH on oxidative damage by the Fenton’s pathway through the GSH and GSH-redox cycle enzymes in 3T3-L1 cells. Materials and methods: 3T3-L1 preadipocytes were exposed to each flavonoid and GSH at concentrations of 0, 5, 10, 15, 20 and 25 µM and then GSH levels and activities of glutathione peroxidase (GSH-Px), …

Efficient Photochemical Synthesis Of Peptide-Α-Phenylthioesters, Andrew Pardo, Tyrone J. Hogenauer, Zhefeng Cai, Julian A. Vellucci, Efrain M. Castillo, Carl W. Dirk, Andreas H. Franz, Katja Michael

College of the Pacific Faculty Articles

Low yields and substantial epimerization of peptide-α-thioesters often compromise the overall efficiency of native chemical ligation (NCL). Peptide arylthioesters are more reactive than peptide alkylthioesters in NCL, but are also more difficult to handle due to their propensity to hydrolyze, and are therefore often generated in situ. However, pre-prepared peptide arylthioesters are required for some NCL applications. Here we present a 7-nitroindoline-based photochemical method that generates protected peptide phenylthioesters under neutral reaction conditions via their activated esters from photoreactive peptide precursors in high isolated yields, and with low levels of epimerization. This method is fully compatible with Fmoc-strategy solid-phase peptide …

Quantitative Analysis Of The Density Of Trap States At The Semiconductor-Dielectric Interface In Organic Field-Effect Transistors, Peter J. Diemer, Zachary A. Lamport, Yaochuan Mei, Jeremy W. Ward, Katelyn P. Goetz, Wei Li, Marcia M. Payne, Martin Guthold, John E. Anthony, Oana D. Jurchescu

Chemistry Faculty Publications

The electrical properties of organic field-effect transistors are governed by the quality of the constituting layers, and the resulting interfaces. We compare the properties of the same organic semiconductor film, 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene, with bottom SiO₂ dielectric and top Cytop dielectric and find a 10× increase in charge carrier mobility, from 0.17 ± 0.19 cm² V⁻¹ s⁻¹ to 1.5 ± 0.70 cm² V⁻¹ s⁻¹, when the polymer dielectric is used. This results from a significant reduction of the trap density of states in the semiconductor band-gap, and a decrease in the …

Enzyme Localization, Crowding, And Buffers Collectively Modulate Diffusion-Influenced Signal Transduction: Insights From Continuum Diffusion Modeling, Peter M. Kekenes-Huskey, Changsun Eun, J. A. Mccammon

Chemistry Faculty Publications

Biochemical reaction networks consisting of coupled enzymes connect substrate signaling events with biological function. Substrates involved in these reactions can be strongly influenced by diffusion “barriers” arising from impenetrable cellular structures and macromolecules, as well as interactions with biomolecules, especially within crowded environments. For diffusion-influenced reactions, the spatial organization of diffusion barriers arising from intracellular structures, non-specific crowders, and specific-binders (buffers) strongly controls the temporal and spatial reaction kinetics. In this study, we use two prototypical biochemical reactions, a Goodwin oscillator, and a reaction with a periodic source/sink term to examine how a diffusion barrier that partitions substrates controls reaction …

Ambiguity In Speaking Chemistry And Other Stem Content: Educational Implications, Mick D. Isaacson, Michelle Michaels

Journal of Science Education for Students with Disabilities

Ambiguity in speech is a possible barrier to the acquisition of knowledge for students who have print disabilities (such as blindness, visual impairments, and some specific learning disabilities) and rely on auditory input for learning. Chemistry appears to have considerable potential for being spoken ambiguously and may be a barrier to accessing knowledge and to learning. Educators in chemistry may be unaware of, or have limited awareness of, potential ambiguity in speaking chemistry and may speak chemistry ambiguously to their students. One purpose of this paper is to increase awareness of potential ambiguity in speaking chemistry and other STEM fields …

Novel Selected Hetero-Atom Doped Carbon From Renewable Resource Materials For Fuel Cell And Supercapacitor Applications, Sunil Kumar Ramasahayam

Theses and Dissertations

Doped carbon materials have gained a lot of attention recently due to their wide array of applications, for example, in dye degradation, energy conversion and storage, electrocatalysis, sensors and electronics. These doped carbon materials are claimed to have a tremendous potential to substitute expensive metal based electrocatalysts in fuel cell and supercapacitor applications. A recently established microwave assisted technique, which does not make use of any inert or reducing gas during the synthesis, was utilized to synthesize doped carbon materials. The method is simple, rapid, economical and high yielding. Renewable resource materials like tannin, spent coffee grounds and thiamine were …

Characterization Of Folic Acid And Poly(Amidoamine) Dendrimer Interactions With Folate Binding Protein: A Force-Pulling Study, Pascale R. Leroueil, Stassi Dimaggio, Abigail N. Leistra, Craig D. Blanchette

University Faculty Publications and Creative Works

Atomic force microscopy force-pulling experiments have been used to measure the binding forces between folic acid (FA) conjugated poly(amidoamine) (PAMAM) dendrimers and folate binding protein (FBP). The generation 5 (G5) PAMAM conjugates contained an average of 2.7, 4.7, and 7.2 FA per dendrimer. The most probable rupture force was measured to be 83, 201, and 189 pN for G5-FA2.7, G5-FA4.7, and G5-FA7.2, respectively. Folic acid blocking experiments for G5-FA7.2reduced the frequency of successful binding events and increased the magnitude of the average rupture force to 274 pN. The force data are interpreted as arising from a network of van der …

Boron-Rich Benzene And Pyrene Derivatives For The Detection Of Thermal Neutrons, Henok A. Yemam, Adam Mahl, Unsal Koldemir, Tyler Remedes, Sean Parkin, Uwe Greife, Alan Sellinger

Chemistry Faculty Publications

A synthetic methodology is developed to generate boron rich aromatic small molecules based on benzene and pyrene moieties for the detection of thermal neutrons. The prepared aromatic compounds have a relatively high boron content up to 7.4 wt%, which is important for application in neutron detection as ¹⁰B (20% of natural abundance boron) has a large neutron induced reaction cross-section. This is demonstrated by preparing blends of the synthesized molecules with fluorescent dopants in poly(vinyltoluene) matrices resulting in comparable scintillation light output and neutron capture as state-of-the art commercial scintillators, but with the advantage of much lower cost. The …

Nanoscale Alloying In Electrocatalysts, Shiyao Shan, Jinfang F. Wu, Ning Kang, Hannah Cronk, Yinguang G. Zhao, Wei Zhao, Zakiya Skeete, Joseph Pharrah, Bryan Trimm, Jin Luo, Chuan-Jian Zhong

Chemistry Faculty Scholarship

In electrochemical energy conversion and storage, existing catalysts often contain a high percentage of noble metals such as Pt and Pd. In order to develop low-cost electrocatalysts, one of the effective strategies involves alloying noble metals with other transition metals. This strategy promises not only significant reduction of noble metals but also the tunability for enhanced catalytic activity and stability in comparison with conventional catalysts. In this report, some of the recent approaches to developing alloy catalysts for electrocatalytic oxygen reduction reaction in fuel cells will be highlighted. Selected examples will be also discussed to highlight insights into the structural …

Substrate-Mediated Deactivation Of A Ru(PTBu2nBn2) Cooperative Complex, John Paul J. Bow, Paul D. Boyle, Johanna M. Blacquiere

Chemistry Publications

Ligand design for metal-ligand cooperative (MLC) catalysis is inherently more complex than that for traditional non-cooperative ligands. The basicity, sterics and structure of the acid/base group in MLC proton-transfer (PT) complexes, for instance, undoubtedly influence catalyst performance. Herein, we evaluate the highly tunable PR2NR′2 (1,5-R′-3,7-R-1,5-diaza-3,7-diphosphacyclooctane) ligand family for the first time in an organic transformation. With [Ru(Cp)(PtBu2NBn2)(MeCN)][PF6] as the catalyst, no turnover was observed in the anti-Markovnikov hydration of alkynes, a known PT MLC reaction. Treatment of the cooperative complex with phenylacetylene affords a vinylammonium product in which the pendant nitrogen atom of the PtBu2NBn2 ligand forms a Lewis acid-base …

Plasminogen Activator Inhibitor-1 Inhibitors And Methods Of Use Thereof To Modulate Lipid Metabolism, Daniel A. Lawrence, Cory Emal, Jacqueline Cale, Enming Joe Su, Mark Warnock, Shih-Hon Li, Jeanne Ann Cupp

Patents

The invention relates to plasminogen activator-I (PAI-1) inhibitor compounds and uses thereof in the treatment of any disease or condition associated with elevated PAI-1. The invention includes, but is not limited to, the use of such compounds to modulate lipid metabolism and treat conditions associated with elevated PAI-1, cholesterol, or lipid levels.

Design, Synthesis And Evaluation Of Bivalent Inhibitors Of Trehalose-6-Phosphate Phosphatase, Chunliang Liu

Chemistry and Chemical Biology ETDs

The D-glucose disaccharide α, α-D-trehalose is synthesized by a variety of bacteria, fungi, plants and invertebrates to support cell survival by functioning as a fuel, a metabolic regulator or a protectant against environmental stress. Five different trehalose biosynthetic pathways are known to exist, one of which, the OtsA/OtsB pathway is common among pathogenic bacteria and fungi and is also found in parasitic nematodes. Previously reported otsA and otsB gene knockout (or knockdown) experiments have shown that both pathway enzymes are essential for M. tuberculosis cell growth and host colonization. RNAi gene silencing carried out in the nematode model system Caenohabditis …

Mining Public Databases For Discovery Of Structure And Function Within The Hotdog-Fold Thioesterase And Had Phosphatase Enzyme Families, Sarah Toews Keating

Chemistry and Chemical Biology ETDs

For my doctoral work, I have developed strategies to mine public databases for data that can be used to infer structural and functional information for the hotdog-fold and HADSF superfamilies. For the hotdog-fold superfamily, I used curated and automatically applied annotations of structure, taxonomic lineage, function, and subfamily membership from the UniProtKB, gene context and taxonomic information from the NCBI, and the results of several in-depth explorations of subfamily/function and structural class membership. Based on the distribution of the aforementioned annotations mapped onto a sequence similarity network (SSN), I applied structural assignments to sequences and/or specific function/subfamily assignments to ~143,000 …

Case Studies Of The Hot Dog-Fold And Acyl-Adenylate-Forming Superfamilies: Characterizing The Importance Of Functional Divergence In Cellular Metabolism, Lucas R. Zimney

Chemistry and Chemical Biology ETDs

Some of the biggest contributors to cellular respiration (and cellular metabolism in general) are acyl-CoA derivatives, a subclass of biological thioesters. Known to function in a variety of pathways, the regulation of their formation and breakdown are critical, carried about by acyl-CoA synthetases and thioesterases, respectively. The work reported within this dissertation will focus on functional divergence within two enzyme superfamilies -- the hot dog-fold and acyl-adenylate-forming superfamilies — and can be broken down into two main parts. Part one will look at tracking the functional divergence within the hot dog-fold superfamily thioesterases. A highly evolved thioesterase, flK, has been …

Generalized Synthesis Of Eas [E = Fe, Co, Mn, Cr] Nanostructures And Investigating Their Morphology Evolution, Prachi Desai, Nikitaa Ashokan, Manashi Nath

Chemistry Faculty Research & Creative Works

This paper illustrates a novel route for the synthesis of nanostructured transition metal arsenides including those of FeAs, CoAs, MnAs, and CrAs through a generalized protocol. The key feature of the method is the use of one-step hot-injection and the clever use of a combination of precursors which are low-melting and highly reactive such as metal carbonyls and triphenylarsine in a solventless setup. This method also facilitates the formation of one-dimensional nanostructures as we move across the periodic table from CrAs to CoAs. The chemical basis of this reaction is simple redox chemistry between the transition metals, wherein the transition …

Determination Of Triapine, A Ribonucleotide Reductase Inhibitor, In Human Plasma By Liquid Chromatography Tandem Mass Spectrometry, Ye Feng, Charles A. Kunos, Yan Xu

Chemistry Faculty Publications

Triapine is an inhibitor of ribonucleotide reductase (RNR). Studies have shown that triapine significantly decreases the activity of RNR and enhanced the radiation-mediated cytotoxicity in cervical and colon cancer. In this work, we have developed and validated a selective and sensitive LC-MS/MS method for the determination of triapine in human plasma. In this method, 2-[(3-fluoro-2-pyridinyl)methylene] hydrazinecarbothioamide (NSC 266749) was used as the internal standard (IS); plasma samples were prepared by deproteinization with acetonitrile; tripaine and the IS were separated on a Waters Xbridge Shield RP18 column (3.5 µm; 2.1 × 50 mm) using a mobile phase containing 25.0% methanol and …

Data In Support Of Quantification Of Pyrophosphate As A Universal Approach To Determine Polymerase Activity And Assay Polymerase Inhibitors, S. Malvezzi, S. J. Sturla, Marina Tanasova

Michigan Tech Publications, Part 1

Characterization of synthetic oligonucleotides and quantification of primer extension mediated by a human translesion synthesis polymerase η (Pol η) over drug-induced DNA lesions in the presence on modified nucleotide analogs is described. Extent of primer extension for each reaction was monitored by denaturing gel electrophoresis. The data was obtained to assess the performance of the fluorescence-based primer extension (PE-PiPer) assay [1] with respect to the established and conventionally used denaturing gel electrophoresis. The obtained data reflects the specific inhibition of translesion synthesis over cisplatin containing DNA with 5-OH-CTP.

Globally Profiling Sialylation Status Of Macrophages Upon Statin Treatment, Dan Wang, Huan Nie, Evgeny Ozhegov, Lin Wang, Aimin Zhou, Yu Li, Xue Long Sun

Chemistry Faculty Publications

Sialic acids (SAs) are widely expressed on immune cells and their levels and linkages named as sialylation status vary upon cellular environment changes related to both physiological and pathological processes. In this study, we performed a global profiling of the sialylation status of macrophages and their release of SAs in the cell culture medium by using flow cytometry, confocal microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). Both flow cytometry and confocal microscopy results showed that cell surface α-2,3-linked SAs were predominant in the normal culture condition and changed slightly upon treatment with atorvastatin for 24 h, whereas α-2,6-linked SAs …

Revision-Polyurethane-Graphene Nanocomposites For Corrosion-Resistant Coatings, Alexandra Rose Stevenson

Master's Theses

Corrosion is a prevalent concern throughout the world, causing significant monetary and safety concerns. Research has been dedicated to developing cost-effective solutions for corrosion that will also meet increasingly stringent environmental regulations. The recently discovered nanomaterial graphene has been proposed as a potential component in anticorrosion technology due to its strong air and water barrier properties. However, graphene is a relatively expensive, difficult to synthesize material. By incorporating it into nanocomposites, its properties can be exploited even at low concentrations. Previous work has been conducted involving the preparation of anticorrosive polystyrene-graphene nanocomposites; these materials were found to be effective long-term …

A Mechanism For Biologically Induced Iodine Emissions From Sea Ice, A. Saiz-Lopez, Christopher S. Blaszczak-Boxe, L. J. Carpenter

Publications and Research

Ground- and satellite-based measurements have reported high concentrations of iodine monoxide (IO) in coastal Antarctica. The sources of such a large iodine burden in the coastal Antarctic atmosphere remain unknown.We propose a mechanism for iodine release from sea ice based on the premise that micro-algae are the primary source of iodine emissions in this environment. The emissions are triggered by the biological production of iodide (I�) and hypoiodous acid (HOI) from micro-algae (contained within and underneath sea ice) and their diffusion through sea-ice brine channels, ultimately accumulating in a thin brine layer (BL) on the surface of sea ice. Prior …

An Allosteric Interaction Links Usp7 To Deubiquitination And Chromatin Targeting Of Uhrf1, Zhi-Min Zhang, Scott B. Rothbart, David F. Allison, Qian Cai, Joseph S. Harrison, Lin Li, Yinsheng Wang, Brian D. Strahl, Gang Greg Wang, Jikui Song

College of the Pacific Faculty Articles

The protein stability and chromatin functions of UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) are regulated in a cell-cycle-dependent manner. We report a structural characterization of the complex between UHRF1 and the deubiquitinase USP7. The first two UBL domains of USP7 bind to the polybasic region (PBR) of UHRF1, and this interaction is required for the USP7-mediated deubiquitination of UHRF1. Importantly, we find that the USP7-binding site of the UHRF1 PBR overlaps with the region engaging in an intramolecular interaction with the N-terminal tandem Tudor domain (TTD). We show that the USP7-UHRF1 interaction perturbs the TTD-PBR interaction of …

Evaluating Sub-Lethal Effects Of Orchard-Applied Pyrethroids Using Video-Tracking Software To Quantify Honey Bee Behaviors, Erin M. Ingram, Julie Augustin, Marion D. Ellis, Blair Siegfried

Department of Entomology: Faculty Publications

Managed honey bee, Apis mellifera L., colonies are contracted to pollinate fruit and nut orchards improving crop quality and yield. Colonies placed in orchards are potentially exposed to pyrethroid insecticides used for broad-spectrum pest control. Pyrethroids have been reported to pose minimal risk to bees due to their low application rates in the field and putative repellent properties. This repellency is believed to alter foraging behavior with the benefit of preventing bees from encountering a lethal dose in the field. However, sub-lethal exposure to pyrethroids may adversely impact bee behavior potentially resulting in social dysfunction or disruption of foraging.

This …

Molecular View Modeling Of Atmospheric Organic Particulate Matter: Incorporating Molecular Structure And Co-Condensation Of Water, James F. Pankow, Marguerite Colasurdo Marks, Kelley C. Barsanti, Abdullah Mahmud, William E. Asher, Jingyi Li, Qi Ying, Shantanu H. Jathar, Michael J. Kleeman

Chemistry Faculty Publications and Presentations

Most urban and regional models used to predict levels of organic particulate matter (OPM) are based on fundamental equations for gas/particle partitioning, but make the highly simplifying, anonymized-view (AV) assumptions that OPM levels are not affected by either: a) the molecular. characteristics of the condensing organic compounds (other than simple volatility); or b) co-condensation of water as driven by non-zero relative humidity (RH) values. The simplifying assumptions have allowed parameterized chamber results for formation of secondary organic aerosol (SOA) (e.g., “two-product” (2p) coefficients) to be incorporated in chemical transport models. However, a return towards a less simplistic (and more computationally …

A Comparative Study Of Polyurethane Nanofibers With Different Patterns And Its Analogous Nanofibers Containing Mwcnts, Javier Macossay-Torres, Faheem A. Sheikh, Hassan Ahmad, Hern Kim, Gary L. Bowlin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Tissue engineering is a multidisciplinary field that has evolved in various dimensions in recent years. One of the main aspects in this field is the proper adjustment and final compatibility of implants at the target site of surgery. For this purpose, it is desired to have the materials fabricated at the nanometer scale, since these dimensions will ultimately accelerate the fixation of implants at the cellular level. In this study, electrospun polyurethane nanofibers and their analogous nanofibers containing MWCNTs are introduced for tissue engineering applications. Since MWCNTs agglomerate to form bundles, a high intensity sonication procedure was used to disperse …

An Analytical Method For Detecting Toxic Metal Cations Using Cyclotriveratrylene Derivative Capped Gold Nanoparticles, Zachary R. Osner, Richard C. Holz, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

Cyclotriveratrylene-oxime (CTV-oxime) derivatives that terminate with a dithiolate linker were synthesized enabling the supramolecular scaffold to adhere to gold nanoparticles (AuNPs) with the bowl-shaped cavity of the CTV scaffold exposed for utilization in host–guest chemistry. Exposure of these CTV functionalized AuNPs to varying concentrations of di- and trivalent metal cations resulted in the formation of large CTV-AuNP polymeric clusters and an accompanying a shift in the plasmon resonance. These interactions between the CTV-AuNPs and the metal cations in solution provides proof-of-concept that supramolecular functionalized AuNPs can be used as a simple and straightforward, on-site detection system for toxic metal cations …

Does Koopmans' Paradigm For 1-Electron Oxidation Always Hold? Breakdown Of Ip/Eox Relationship For P-Hydroquinone Ethers And The Role Of Methoxy Group Rotation, Marat R. Talipov, Anitha Boddeda, Sergey V. Lindeman, Rajendra Rathore

Chemistry Faculty Research and Publications

Koopmans’ paradigm states that electron loss occurs from HOMO, thus forming the basis for the observed linear relationships between HOMO/IP, HOMO/E_ox, and IP/E_ox. In cases where a molecule undergoes dramatic structural reorganization upon 1-electron oxidation, the IP/E_ox relationship does not hold, and the origin of which is not understood. For example, X-ray crystallography of the neutral and cation radicals of bicyclo[2.2.1]heptane-annulated p-hydroquinone ethers (^THE and ^MHE) showed that they undergo electron-transfer-induced conformational reorganization and show breakdown of the IP/E_ox relationship. DFT calculations revealed that Koopmans’ …

The Ras G Domain Lacks The Intrinsic Propensity To Form Dimers, Elizaveta A. Kovrigina, Azamat R. Galiakhmetov, Evgenii L. Kovrigin

Chemistry Faculty Research and Publications

Ras GTPase is a molecular switch controlling a number of cellular pathways including growth, proliferation, differentiation, and apoptosis. Recent reports indicated that Ras undergoes dimerization at the membrane surface through protein-protein interactions. If firmly established this property of Ras would require profound reassessment of a large amount of published data and modification of the Ras signaling paradigm. One proposed mechanism of dimerization involves formation of salt bridges between the two GTPase domains (G domains) leading to formation of a compact dimer as observed in Ras crystal structures. In this work, we interrogated the intrinsic ability of Ras to self-associate in …

Modeling Volatile Organic Compound Emission From Materials Used In Passenger Vehicle Interiors, Shane Canaday

Master's Theses and Doctoral Dissertations

Travel is an everyday necessity for many people, making the environment of a passenger vehicle a place where they spend a significant amount of time. Previous studies have indicated that more than 100 volatile organic compounds (VOCs) are present in ambient air within the cabins of new cars, some of which have been found to have adverse health effects. While previous VOC models have been produced, there is still uncertainty in these models with respect to changing variables such as temperature, sunlight, and the presence of multiple VOCs. An accurate and reliable model, capable of determining the concentration of different …

Synthesis And Characterization Of A Family Of Air-Stable Ferrocene- And Ruthenocene-Containing Primary, Secondary, And Tertiary Phosphines, Amir Rabiee Kenaree, Tyler J. Cuthbert, Stephanie M. Barbon, Paul D. Boyle, Elizabeth R. Gillies, Paul J. Ragogna, Joe Gilroy

Chemistry Publications

The synthesis and characterization of a family of air-stable primary, secondary, and tertiary phosphines containing all possible combinations of ethylferrocene and ethylruthenocene substituents are reported. Each phosphine was characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy, IR and UV-vis absorption spectroscopy, mass spectrometry, and elemental analysis. With the exception of primary ethylruthenocene phosphine 8a, all of the title compounds have been studied by single crystal X-ray crystallography. Ferrocene-containing phosphines showed maximum absorption at wavelengths of ca. 440 nm and qualitatively reversible oxidation waves in their cyclic voltammograms with intensities scaling to the number of ferrocene units …

Effect Of Adsorption Potential On Co Oxidation At Au@Pt Nanoparticles Electrodes, A Surface Enhanced Raman Spectroscopic Study, Pu Zhang, Yi Wei, Yong-Li Zheng, Yan-Xia Chen, Zhong-Qun Tian

Journal of Electrochemistry

The adsorption/oxidation of CO on the 55 nm [email protected] nm Pt nanoparticles electrode in both potentiodynamic and potentiostatic modes were investigated by surface enhanced Raman spectroscopy in a thin layer electrochemical flow cell under controlled mass transport, with the aim of clarifying the origin CO oxidation at lower electrode potentials (in current pre-wave region of corresponding cyclic voltammograms). Our results demonstrated that the CO oxidation kinetics differed significantly from the three kinds of different CO adsorption history, with almost no CO oxidation current in the pre-peak potential region after 0.35 V_RHE CO adsorption with or without subsequent holding the …