Potential-modulated electrochemiluminescence of a tris(2,2′-bipyridine) ruthenium(II) / lidocaine system under 430 kHz ultrasound irradiation

ArticleUltrasonics Sonochemistry. 63: 104947 (2020)journal articl

Enzymatic flow injection method for rapid determination of choline in urine with electrochemiluminescence detection

In order to determine trace choline in human urine, a flow injection analysis (FIA) system has been developed by coupling an enzyme reactor with an electrochemiluminescence (ECL) detector. The enzyme reactor is prepared by covalently immobilizing choline oxidase (ChOx) onto the aminopropyl-controlled pore glass beads, which are then carefully packed into a micro column. The enzyme reactor catalyzes the production of hydrogen peroxide that is in direct proportion to the concentration of choline. In this study, the enzymatically produced hydrogen peroxide was detected by an ECL detector positioned at the down stream of an enzyme react:or based on the luminol/H2O2 ECL system. Under the optimized condition, the enzymatic FIA/ECL provided high sensitivity for the determination of choline with the detection limit as low as 0.05 mu M (absolute detection limit was at sub pmol level). The method was successfully applied in the determination of choline in the samples of human urine, and the analytical results were in good agreement with those obtained by using the microbore HPLC with an immobilized enzyme reactor-electrochemical detection system.ArticleBioelectrochemistry. 79(1):147-151 (2010)journal articl

Characterization of electrochemiluminescence of tris(2,2′-bipyridine)ruthenium(II) with glyphosate as coreactant in aqueous solution

Glyphosate, a phosphorus-containing amino acid type herbicide was used as a coreactant for studying of electrochemiluminescence (ECL) reaction of tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] in an aqueous solution. In a phosphate buffer solution of pH 8, glyphosate itself was known to be electrochemically inactive at glassy carbon electrode, however, it participated in a homogeneous chemical reaction with the electrogenerated Ru(bpy)(3)(3+), and resulted in producing Ru(bpy)(3)(2+) species at the electrode surface. Kinetic and mechanistic information for the catalysis of glyphosate oxidation were evaluated by the steady-state voltammetric measurement with an ultramicroelectrode. The simulated cyclic voltammogram based on this mechanism was in good agreement with that obtained experimentally. ECL reaction of Ru(bpy)(3)(2+)/glyphosate system was found to be strongly dependent on the media pH. In a pH region of 5-9, an ECL wave appeared at ca. +1.1 V vs. Ag/AgCl, which was caused by the generation of *Ru(bpy)(3)(2+) via a Ru(bpy)(3)(3+)-mediated oxidation of glyphosate. When pH >10, a second ECL wave was observed at ca. +1.35 V vs. Ag/AgCl, which was believed to be associated with a reaction between Ru(bpy)(3)(3+) and the species from direct oxidation of GLYP at a GC electrode surface.ArticleElectrochimica Acta 55(20):5532-5537 (2010)journal articl

High-Frequency Heating Extraction Method for Sensitive Drug Analysis in Human Nails

ArticleMolecules. 23(12): 3231(2018)journal articl

Double photon emission coincidence imaging with GAGG-SiPM Compton camera

Compton imaging is a promising gamma-ray imaging method based on the Compton scattering kinematics due to high Compton scattering probability for sub-MeV to MeV gamma-rays. A conventional Compton camera has a disadvantage of low signal-to-background ratio (SBR), which is caused by drawing of multiple Compton cones. A method to solve this fundamental problem is the double-photon emission computed tomography (DPECT), which uses the coincidence detection for cascade gamma-rays and significantly increases the SBR using intersections of two Compton cones. In this study, we demonstrated the DPECT method by using 134Cs radio isotope, which is one of important radioisotopes for the imaging of fuel debris, with two Ce:Gd(Al,Ga)O12 (GAGG) scintillator Compton cameras

Ecological considerations on the development, conservation of environment and the assistance to developing countries for peace

The effects of agricultural development on the environment, as a means of assisting developing countries in tropical regions. are considered as an ecological aspect of human activity. Good results, with high short-term productivity, were obtained from the development by modern agricultural technology, for example. by increased crop-yields from the use of new varieties and chemicals and by farm cultivation through deforestation. However, in the long term harmful effects accumulated for agricultural land, with the loss of stability of production, and with the onset of 'desertification', due to poor understanding of the ecosystem. The ecological activities of organisms are reviewed from the viewpoint of two aspects: disoperation (an 'opposing' term), such as competition and exploitation, and cooperation (a 'harmonizing' term), such as mutualism and aggregation, which are characteristic to each species of organism in the pioneer phase and in the climax phase of the ecological succession, respectively. The human population, as one species of the biological community in the ecosystem, possesses the two aspects within a population and even in an individual. The pioneer character of the human population promotes the development of civilization in human society, but this character often accompanies the disoperative character, as so-called r-strategic organisms. On the other hand, its climax (so-called K-strategic) character tends to conserve nature against the development of environment. The human being has a special character of elasticity, which is an ability to integrate the two terms in harmony, thus creating culture. The assistance of developing countries by those more developed, would promote peace, when they keep cooperation with each other both at the national level and at the personal level

A comprehensive approach for managing feasible solutions in production planning by an interacting network of Zero-Suppressed Binary Decision Diagrams

Product Lifecycle Management (PLM) ranges from design concepts of products to disposal. In this paper, we focus on the production planning phase in PLM, which is related to process planning and production scheduling and so on. In this study, key decisions for the creation of production plans are defined as production-planning attributes. Production-planning attributes correlate complexly in production-planning problems. Traditionally, the production-planning problem splits sub-problems based on experiences, because of the complexity. In addition, the orders in which to solve each sub-problem are determined by priorities between sub-problems. However, such approaches make solution space over-restricted and make it difficult to find a better solution. We have proposed a representation of combinations of alternatives in production-planning attributes by using Zero-Suppressed Binary Decision Diagrams. The ZDD represents only feasible combinations of alternatives that satisfy constraints in the production planning. Moreover, we have developed a solution search method that solves production-planning problems with ZDDs. In this paper, we propose an approach for managing solution candidates by ZDDs׳ network for addressing larger production-planning problems. The network can be created by linkages of ZDDs that express constraints in individual sub-problems and between sub-problems. The benefit of this approach is that it represents solution space, satisfying whole constraints in the production planning. This case study shows that the validity of the proposed approach