Strategic Trade and Industrial Policies with International R&D Spillovers

本稿では,企業の研究開発(R&D)の成果が国境を越えてスピルオーバーする国際貿易モデルにおいて,輸出補助金ならびにR&D補助金の効果を分析する.国際寡占企業間のR&D投資競争がクールノー型数量競争ないしベルトラン型価格競争に先んじて行なわれるという仮定のもとで,輸出国の貿易政策と産業政策の最適な組合せを導出する.最適な輸出補助金とR&D補助金の符号は製品間の代替性,R&Dスピルオーバーの程度,そしてR&D投資の効率性をそれぞれ表すパラメーターに依存して変化することが示される.さらに,輸出国にとって利用可能な政策手段が1つしかない状況下での輸出補助金あるいはR&D補助金の最適性を検討する

Flow-injection amperometric determination of DOPA and tyrosine at a dual electrode modified with the gold–Cobalt binary system

© Pleiades Publishing, Ltd., 2018. The gold–cobalt binary system, electrodeposited on the surface of a screen-printed electrode, exhibits catalytic activity in the electrooxidation of DOPA and tyrosine. The catalytic effect is shown in a multiple increase in current compared with the oxidation current of the modifier and a decrease in the oxidation overvoltage of organic compounds. Methods for the flow-injection amperometric determination of DOPA and tyrosine at the proposed modified electrode are developed. The simultaneous amperometric determination of DOPA and tyrosine at a dual screen-printed electrode modified with an Au–Co binary system the under conditions of flow-injection analysis is demonstrated. The linear dependence of the analytical signal on the concentration of DOPA and tyrosine is observed in the ranges from 1 × 10−9 to 1 × 10−4 M and from 5 × 10−8 to 5 × 10−4 M, respectively

The electrochemistry of fluorinated β-ketoamines, their sulfur analogues and metal chelates in nonaqueous media

The electrochemistry of eighty fluorinated β-ketoamines, β-thioketoamines, monothio-β-diketones and their complexes of Cu(II) and Ni(II) in dimethylformamide has been investigated. The reduction products of the ligands (LH2) are found to be unstable anion-radicals; the chemical and electrochemical transformations of the latter result in the elimination of the F- ion. Metal complexes are characterized by reversible electron transfer. According to ESR data either Ni(I)(LH)2 or Ni(II)(LH)-{radical dot} 2 are formed as the one-electron reduction products. The dependence of the electrochemical and ESR parameters of complexes on the ligand structure is discussed. © 1984

Electrochemical Biosensors for Inhibitor Determination: Selectivity and Sensitivity Control

The behavior of cholinesterase based potentiometric and amperometric biosensors with renewable membranes toward irreversible inhibitor determination has been investigated. Tracing paper, gelatin and cellulose nitrate were examined, as membrane materials. The membranes are replaced in the biosensor assembly after 15-20 inhibition measurements. The detection limits as well as other analytical characteristics of inhibitor determination for different enzyme supports and detection systems are compared and discussed

Term "nano" in electroanalysis: A trendy prefix or a new stage of its development?

The use of term "nano" in electroanalytical methods (electroanalysis) is considered. Attention is paid to the recent trend in the development of electroanalysis in context of modern views on processes in the double electric layer, or interface, as a nanosize structure in an electrochemical nanoreactor determining the nature of the analytical signal. It is shown that the creation of new methods of chemical analysis of usual objects using nanostructures, nanosystems, and nanomaterials immobilized in an electrochemical interface has favored the development of nanoelectroanalytics. The use of terms with the prefix nano- in electroanalysis and some nanotechnologies is considered. It was noticed that the nomenclature in the nanofield has not been established yet. Not only the available terms should be refined and formulated, but also those that have not been adequately translated into Russian. With the application of nanotechnologies, electroanalysis follows the world trend in the choice of priority objects of analysis. © 2013 Pleiades Publishing, Ltd

Spice Antioxidants as Objects of Analytical Chemistry

© 2018, Pleiades Publishing, Ltd. Abstract: The literature data on the antioxidant composition of spices are summarized; methods of the extraction of antioxidants of various classes from plant material and their advantages and disadvantages are discussed. The possibilities of using ultrasonic, microwave, and enzymatic treatment of raw materials for increasing the recovery of target components and their stabilization are considered. The present-day approaches to the identification and quantification of antioxidants in extracts of spices, based on the use of high-sensitive and high-resolution detectors in chromatography and involving new materials (mostly nanoscale) as modifiers of the electrode surface in electrochemical methods, are described. A comparative analysis of the methods of the overall evaluation of the antioxidant properties of spices with the help of integral parameters is carried out

Evaluation of the antioxidant properties of spices by cyclic voltammetry

© 2014, Pleiades Publishing, Ltd. The individual antioxidants of spices (gallic and rosmarinic acids, capsaicin, thymol, and eugenol) are irreversibly oxidized at 0.88–1.25 V at a glassy carbon electrode in 0.1 M LiClO4 solution in ethanol. Corresponding electrode reactions are proposed. A linear dependence of the oxidation step area on the concentration is observed for all the analytes. The detection limits and the lower limits of quantification vary from 0.57–12 and 1.8–40 μM, respectively. Distinct steps and peaks of oxidation are observed on cyclic voltammograms of the methanolic extracts of spices; the potentials and areas of these peaks depend on the type of spice. The contribution of individual antioxidants to integral responses of spice extracts is evaluated. A method is developed for the voltammetric evaluation of the antioxidant capacity (AOC) of spices based on the oxidation of their antioxidants. The total area of the oxidation steps was selected as a parameter characterizing the antioxidant properties. The AOC of spices was expressed as a weight of gallic acid in milligrams per 1 g of a dry spice. Seventeen different spices were tested. The AOC decreases in the series of clove > juniper berries > nutmeg > cinnamon > rosemary > anise ≥ oregano > black pepper ≥ ginger ≥ basil > turmeric > red pepper ≈ bay leaf ≥ coriander ≈ red sweet pepper > cumin > caraway. A correlation between the AOC obtained by voltammetry and the total AOC, ferric reducing power, antiradical activity, and total content of phenolic compounds and these parameters with each other is found; the correlation coefficients vary in the range 0.8886–0.9615

Natural phenolic antioxidants in bioanalytical chemistry: State of the art and prospects of development

© 2015 Russian Academy of Sciences and Turpion Ltd. Published data of the last decade on the chemical analysis and related problems of investigation of phenolic antioxidants as components of complex biomedical and food objects are generalized. The physicochemical properties of these compounds are presented in accordance with the up-to-date classification of their structures. Particular attention is paid to the development of new and advancement of traditional methods for determination of natural phenolic antioxidants in relation to public health protection problems. The interdisciplinary character of the considered problems is emphasized and the ways for problem solution are outlined

Electroanalysis of antioxidants in pharmaceutical dosage forms: State-of-the-art and perspectives

© Springer-Verlag Wien 2015. Abstract Recent developments and future trends in electroanalytical chemistry of antioxidants in pharmaceutical dosage forms are discussed. The advantages of constant-current coulometry and different types of voltammetry in particular rapid response, sensitivity, selectivity, and low detection limits are demonstrated. The special attention is paid to various types of chemically modified electrodes including carbon nanomaterials, nanoparticles of metals, self-organized systems, and their combination. The data presented confirm that electroanalysis can be considered as alternative or additional technique to spectrophotometric and separation methods for determination of antioxidants in pharmaceuticals