Li-ion battery system is a successful example for putting the intercalation theory into practice. An overview on the principle, cell chemistry, components, performance characteristics and advances of the Li ion battery is presented.

BACKGROUND:The aims of this study were to develop immunologic reagents and a sensitive and specific immunoassay for human kallikrein 13 (hK13) and to examine the presence of hK13 in human tissues and biological fluids.METHODS:Recombinant hK13 protein was produced and purified with use of a Pichia pastoris yeast expression system. The protein was used as an immunogen to generate mouse monoclonal and rabbit polyclonal anti-hK13 antibodies. A sandwich-type immunoassay was developed with these antibodies. The assay was used to measure hK13 in various biological fluids and tissue extracts. Immunohistochemical analysis was also performed on nondiseased and cancerous prostatic sections.RESULTS:The hK13 immunoassay had a detection limit of 0.05 micro g/L and showed no cross-reactivity with homologous kallikreins. The assay was linear at 0-20 micro g/L, and within-and between-run CVs were <10% (n = 12). hK13 was detected in tissues, including esophagus, tonsil, trachea, lung, cervix, and prostate. hK13 was also found in seminal plasma, amniotic fluid, follicular fluid, ascites of ovarian cancer patients, breast milk, and cytosolic extracts of ovarian cancer tissues. hK13 was immunohistochemically localized in epithelial cells of both nondiseased and cancerous prostate. hK13 appears to be overexpressed in 50% of ovarian cancer tissues compared with healthy ovarian tissues. Recovery of active enzyme added to milk or amniotic fluid was 70-98%, but was <20% when added to serum, suggesting rapid sequestration by protease inhibitors. In fluids and tissue extracts, hK13 was found in its free (approximately 30 kDa) form.CONCLUSIONS:This immunofluorometric assay for hK13 may be used to examine the value of hK13 as a disease biomarker and to further explore the physiologic and pathobiologic role of this enzyme in human disease.

We have previously reported the successful development of a targeted genetic method for the creation of temperature-sensitive vaccinia virus mutants [D. E. Hassett and R. C. Condit (1994)Proc. Natl. Acad. Sci. USA91, 4554–4558]. This method has now been applied to the large subunit of the multifunctional vaccinia virus capping enzyme, encoded by gene D1R. Ten clustered charge-to-alanine mutations were created in a cloned copy of D1R. Four of these mutations were successfully transferred into the viral genome using transient dominant selection, and each of these four mutations yielded viruses with plaque phenotypes different from that of wild-type virus. Two of the mutant viruses, 516 and 793, were temperature sensitive in a plaque assay. Mutant 793 was also temperature sensitive in a one-step growth experiment. Phenotypic characterization of the 793 virus under both permissive and nonpermissive conditions revealed nearly normal patterns of viral protein and mRNA synthesis. Under nonpermissive conditions the 793 virus was defective in telomere resolution and blocked at an intermediate stage of viral morphogenesis.In vitroassays of various capping enzyme activities revealed that in permeabilized virions, enzyme guanylylate intermediate formation was reduced and methyltransferase activity was thermolabile, while in solubilized virion extracts enzyme guanylylate activity was reduced and both guanylyltransferase and methyltransferase activities were absent. Thus, the 793 mutation affects at least two separate enzymatic activities of the capping enzyme, guanylyltransferase and methyltransferase, and when incorporated into the virus genome, the mutation yields a virus that is temperature sensitive for growth, telomere resolution, and virion morphogenesis.

The electro-oxidation of dihydronicotinamide adenine dinucleotide (NADH) on three low-index basal single crystal gold faces was studied in a phosphate buffer solution. The reaction was found highly structure-sensitive; the Au(100) and Au(111) faces showed a high electrocatalytic activity, while the Au(110) face was much less active. The high electrocatalytic effect was attributed to the oxidation-mediator ability of the partially discharged OH(1 − r)− species on the gold surface. The structural effect of the gold faces on the electro-oxidation of NADH may result from the difference in the adsorption of NAD+, via its pyridine moiety as the adsorption site, on the different gold faces. The possibility of developing a highly sensitive NADH sensor based on the electrochemical faceting technique is suggested.

The underpotential deposition (upd) of Pb and Cd on Ag(111) and Au(111) single crystals grown on freshly cleaved mica has been examined in propylene carbonate (PC), water, tetrahydrofuran (THF), and dimethoxyethane (DME) by cyclic voltammetric techniques. Insight into the cleanliness of the single crystal metal electrode/non-aqueous electrolyte interfaces was gained from a comparison of the potential (E) dependence of the differential capacity (C) in PC solutions with that reported in aqueous media. The cyclic voltammetric features for the Pb/Ag(111) and Pb/Au(111) upd systems in PC were found to be very similar to those obtained in aqueous media. This behavior was unlike that observed for the upd of Cd on these single crystal substrates in the same two solvents, for which the differences in the voltammetric features, especially in the case of Ag(111), were quite substantial. This latter effect has been ascribed, in part, to the ability of Cd ad-ions to undergo partial discharge on the electrode surface, a factor that changes the solvation characteristics of the adsorbed species and thus modifies the energetics and kinetics of the upd process. For solvents of low dielectric constant, ie THF and DME, the same four upd/substrate systems yielded highly distorted cyclic voltammetry curves. This has been tentatively attributed to extensive ion pairing both at the interface and in the bulk electrolyte. The presence of ion-pairs in the solution phase was evidenced by the lifting of the degeneracy of the v(4) mode of the perchlorate ion (as monitored by transmission FTIR measurements), for which the detailed nature of the band splitting was found to be metal-ion specific.

The feasibility of a metal palladium electrode as the pH sensor in air-saturated aqueous solutions was evaluated. The measurement was based on an ''on-site'' precleaning step and a potential decay process. The experimental results showed a linear pH response with a sensitivity of around 60 mV/pH and good reproducibility. The temperature effect on the measurement was also evaluated.

A fiber-optic-based pH sensor using phenol red as the indicator is described. This pH sensor employs two different optical fibers, one a hard polymer-cladded silica core and one a fluorinated acrylic-cladded methyl-methacrylate core, and is constructed in a single-path device that increases the signal level and simplifies the signal processing and the replacement of the dye. The sensor performs reasonably well over the pH range 6.0–8.0 in terms of the sensitivity and reproducibility. The sensor shows a response time of 2–5 min and can operate for up to seven days with periodic calibrations. The major limiting factor in the sensor's operational life is the deterioration of the membrane and thus the leakage of phenol red from the gel matrix.

Studies of in-situ Fourier transform infrared reflection-absorption spectroscopy (FTIRRAS) showed that L-ascorbic acid (AA) undergoes a spontaneous dissociative or destructive adsorption at a Pt electrode in acid solutions at the hydrogen adsorption-desorption region with linearly bonded carbon monoxide (CO)L as the adsorbate. This dissociative adsorption process most likely takes place via an interaction between the side-chain of AA and the Pt surface. The overall electro-oxidation of AA at Pt in acid solutions may involve a contribution from its ethylene glycol (EG)-like side-chain portion as well as its lactone ring portion. This process may consist of three major stages: (1) dissociative adsorption via the EG-like side-chain to form (CO)L on Pt at the hydrogen adsorption-desorption region; (2) direct oxidation via the lactone ring to form dehydro-L-ascorbic acid (DHA) and its hydrated derivatives in the potential region from the onset of oxidation to the current peak; (3) the EG-like side-chain and (CO)L undergo further oxidation to form CO2 as the final product when the potential is driven to a more positive region.

The experimental results obtained in this study show that a thick-film graphite sensor assembly (with a Pt counter and an Ag/AgCl reference electrode) can be conveniently fabricated by the photolithographic and screen-print metallization techniques. This sensor has been successfully employed for quantitatively determining L-ascorbic acid concentration in aqueous solutions with reasonably good reproducibility. This sensor provides the possibility of developing a miniature size practical device for detecting ascorbic acid in biochemical processing, such as in food and drug production. The mechanistic aspects of the oxidation of L-ascorbic acid on optical pyrolytic graphite electrodes were further studied with a rotating OPG disk electrode in two different electrolyte solutions. It was found that the oxidation of L-ascorbic acid is more favored in pH = 7 solutions than in pH = 1 solutions although a common 2-electron transfer pathway is applied in both cases.

Optical fiber sensors have gained much attention in recent years. Optical fiber based chemical sensors often use a reaction chamber within which a chemical reaction involving the sensing species occurs. A color change may result from this chemical reaction and, with light passing through the reaction chamber, the light intensity can be modulated by this color change. Consequently, this change in light intensity can be used to quantify the sensing species present. In most of these chemical sensors, either one or two optical fibers will be used. If a single fiber is used, the signal derived from the chemical reaction is relatively weak. On the other hand, if either one or two optical fibers are used, a mirror-finished surface is usually required for the reflection of light to the detector. In this research, optical fiber sensors are constructed using two different types of fibers. One is a quartz fiber and the other is a plastic fiber. The plastic fiber is more flexible and can be bent or connected with a slant surface at the top of the fiber at 45 degree(s). Two types of sensors were constructed--a temperature sensor employing a thermochromic solution and a pH sensor using a pH sensitive dye. By using the two types of fiber, a mirror-finished surface is no longer necessary. The weak signal due to the use of a single fiber is also minimized.

The electro-oxidation Of L-ascorbic acid is examined on three low index planes of gold single crystals in various aqueous electrolytes. The overall oxidation process in the double-layer potential region of gold consists of two major stages. The first stage is structure insensitive and is not affected significantly by anions of different specific adsorption ability. This stage corresponds to an outer-sphere two-electron transfer process with the formation of dehydro-L-ascorbic acid and/or its hydration product as the primary product. The second stage is structure sensitive and is affected significantly by the anions in solution. This stage is believed to correspond to the further oxidation of dehydro-L-ascorbic acid, which is an inner-sphere process.

The electrochemical oxidation of carbon monoxide on a platinum-Nafion electrode was examined. It was found that the oxidation of CO on the Pt-Nafion electrode is more favored in an acidic solution than in an alkaline medium. This is in contrast with what was reported for bulk metal electrodes, for which the oxidation rate of CO in acid is much smaller than in alkaline solutions. This phenomenon is believed to be directly related to the cation-exchange capability of the Nafion membrane. The rest potential of the Pt-Nafion electrode was found to be dependent on the partial pressure of CO, which is also in contrast with the behavior of bulk metal electrodes. This result was attributed to a mixed potential phenomenon. A quantitative determination of CO concentration in the gas phase was carried out on the basis of the Pt-Nafion electrode system in a controlled-potential mode. The results obtained showed a number of attractive properties, including a low detection limit, good reproducibility, and a fast response time.

Electrochemical oxidation of α-D( + )-glucose on a polycrystalline platinum electrode in 0.1 M HC1O4 was studied in situ by Fourier transform infrared reflection-absorption spectroscopy. The spectra showed unambiguously that the major adsorbate on the platinum surface during the glucose oxidation over the potential range −0.20 to +0.40 V vs. a saturated calomel reference electrode is linearly adsorbed CO. The strong adsorption of this species inhibits the electrode reaction. The oxidation products in the solution were found to be gluconolactone, carboxylic acids and CO2 whose formation occurred to the greatest extent in the platinum oxide region.

Abstractis found to be dependent on the pH of the nitrate solution.

Rotating ring‐disk electrode techniques have been employed for the investigation of the electrocatalytic reduction of nitrate induced by underpotential‐deposited cadmium on Au and Ag surfaces. Based on Albery's kinetic analysis it has been concluded that for concentrations of nitrate in the millimolar range, the reaction products depend on the of the solution. Specifically, for , the reaction yields predominantly nitrite, whereas for , the process proceeds beyond the nitrite stage to generate products which do not undergo oxidation on a Au ring electrode polarized at potentials as high as 1.0V vs. SCE. Additional evidence in support of these results was provided by exhaustive bulk electrolysis experiments. The lack of linearity of some of Albery's diagnostic plots could be accounted for quantitatively by a numerical integration of the differential equations which govern disproportionation‐type reactions at rotating ring electrodes. Good agreement was found between theory and experiment using independently determined values for the rate constant of disproportionation of in solution.

AbstractAn underpotential‐deposited cadmium layer formed on a gold electrode was used to amperometrically determine PCO2 in an aqueous medium. This electrode reduces nitrate anions in an aqueous solution. The reduction current produced can be related to the proton concentration. Thus, when dissolved CO2 is present in a nitrate solution it alters the proton concentration, which can then be measured amperometrically. Experimental investigation of this system and a Nafion coated gold electrode were both carried out. The effect of oxygen present in the system is also discussed.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIonic transport effects in in situ Fourier-transform infrared reflection adsorption spectroscopyIn Tae. Bae, Xuekun. Xing, Ernest B. Yeager, and Daniel. SchersonCite this: Anal. Chem. 1989, 61, 10, 1164–1167Publication Date (Print):May 15, 1989Publication History Published online1 May 2002Published inissue 15 May 1989https://pubs.acs.org/doi/10.1021/ac00185a022https://doi.org/10.1021/ac00185a022research-articleACS PublicationsRequest reuse permissionsArticle Views100Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

The formation of submonolayers of Cu adatoms on polycrystalline Au in 0.1 M HClO4 solutions containing only perchlorate anions has been found to proceed at unusually slow rates. This has made it possible to examine the electrocatalytic activity of submonolayer coverages of Cu adatoms exhibiting UPD like properties at potentials more negative than Cu bulk deposition. Rotating ring disk measurements have provided evidence that such layers show electrocatalytic properties for the reduction of nitrate. This process proceeds by a parallel mechanism yielding nitrite as one of the intermediates.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical oxidation of nitrite on a rotating gold disk electrode: a second-order homogeneous disproportionation processXuekun. Xing and Daniel A. SchersonCite this: Anal. Chem. 1988, 60, 14, 1468–1472Publication Date (Print):July 15, 1988Publication History Published online1 May 2002Published inissue 15 July 1988https://pubs.acs.org/doi/10.1021/ac00165a023https://doi.org/10.1021/ac00165a023research-articleACS PublicationsRequest reuse permissionsArticle Views345Altmetric-Citations48LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts