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Volume 66, Issue 1
Displaying 1-6 of 6 articles from this issue
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Annual Topic “photo” : Accounts
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Shunsuke TOMITA, Keitaro YOSHIMOTO, Osamu NIWA, Ryoji KURITAArticle type: Annual Topic “photo” : Accounts
2017 Volume 66 Issue 1 Pages 1-10
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESS"Selectivity" is generally thought to be a key feature of probe molecules that are used to detect proteins, while a novel method for protein detection utilizing the "cross-reactivity" of molecule libraries has been proposed, called Cross-reactive Optical Fingerprinting (COF). In this paper, we summarize the principle and examples of COF for protein identification, followed by the introduction of our approaches to construct COF using polyion complexes (PICs) between enzymes and ionic polymers. In this approach, PICs with various characteristics were used to obtain unique optical fingerprints of changes in enzyme activity for analyte proteins. Statistical analysis of the obtained fingerprints has enabled the identification of human plasma proteins and albumin homologues. In addition, we have recently proposed "secretome fingerprinting" based on discriminating compositions of proteins secreted from cultured cells. This system has successfully allowed markerless and noninvasive identification of cancer cell types and lineages of stem cell differentiation.View full abstractDownload PDF (2519K)
Annual Topic “Transcendence” : Analytical Reports
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Naoki TACHIBANA, Saori IKEDA, Yasuyuki YUKAWA, Masahiro KAWAGUCHIArticle type: Annual Topic “Transcendence” : Analytical Reports
2017 Volume 66 Issue 1 Pages 11-17
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESSX-ray photoelectron spectroscopy (XPS) is used to analyze La-based perovskite-type oxide nanoparticles of interest in electrocatalytic activity for the oxygen reduction reaction. Well-dispersed perovskite nanoparticles were successfully prepared via a reverse micelle method. Their oxygen reduction activity and surface chemical states were investigated by using rotating disk electrode voltammetry and XPS. Mn 2p and 3s, and Fe 2p photoelectron spectra were analyzed to probe the oxidation states for the perovskite-type oxide nanoparticles. The peak position of the Mn 2p3/2 core level and the Mn 3s splitting on La0.5Ca0.5Mn0.9Fe0.1O3 with superior electrocatalytic activity shifted to a higher binding energy and to more narrow than that on LaMnO3, indicating that the negative charge caused by the partial substitution for La3+ by Ca2+ was compensated by an oxidation state increase of a part of Mn3+ to Mn4+. Therefore, XPS characterization of La0.5Ca0.5Mn0.9Fe0.1O3 nanoparticles clarified the existence of Mn4+, which is important in the oxygen reduction activity.View full abstractDownload PDF (859K)
Accounts
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Hirosuke TATSUMIArticle type: Accounts
2017 Volume 66 Issue 1 Pages 19-25
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESSPolarography with dropping carbon fluid electrodes (DCFEs) was studied. Carbon fluids were prepared by mixing graphite powder and binder liquids (low-viscosity liquid paraffin, etc.), delivered by a syringe pump, and injected from the tip of a capillary into a test solution. Using this carbon drop as a working electrode, the polarography of ferrocenecarboxylate (FcCOO−) was performed. Well-defined polarograms with clear limiting currents were observed when the size of the DCFE was sufficiently small. A log plot analysis showed that IR drop was significant at large DCFEs, but nearly reversible polarographic waves could be obtained at small DCFEs. The dependence of the limiting current on the concentration of FcCOO− and on the flow rate of the electrode was in fairly good agreement with the prediction from the Ilkovic equation, suggesting that the equation was applicable to DCFE. The available potential range and the potential of zero charge were also discussed.View full abstractDownload PDF (1196K)
Technical Papers
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Chushiro YONEZAWA, Katsuhiro SHIRONO, Tomoko HARAGAArticle type: Technical Papers
2017 Volume 66 Issue 1 Pages 27-37
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESSThe uncertainties of the analysis results of 134Cs, 137Cs and 40K in the Brown Rice certified reference material by gamma-ray spectrometry using a Ge detector have been evaluated. The massic activities of 134Cs, 137Cs and 40K in the CRM were determined by a simple comparison and efficiency curve methods using standard gamma-ray sources of the analyzing radionuclides and a multi-nuclides mixed standard source, respectively, for gamma-ray peak efficiency calibration. Standard uncertainties of constituted parameters of the model equations of the analysis methods were determined from close examination of each uncertainty component of the parameters. Although it is not contained in the model equations, a parameter of repeatability due to a variation of the sample volume, of the geometrical condition and of the sample preparation were evaluated by an experiment using radionuclide standard solutions of 137Cs and 152Eu. The evaluated combined standard uncertainties of each parameter of the model equations were further combined following the uncertainty propagation law and obtained expanded uncertainties multiplying by a coverage factor (k = 2). Gamma-ray peak efficiency and net peak count were the largest uncertainty components in the simple comparison method, and those of the other components were negligibly small. As compared to the simple comparison method, due to the additional component of true coincidence summing (TCS) correction and gamma-ray emission probability, expanded uncertainty of the efficiency curve method was larger than that of the simple comparison method. Due to lack of appropriate information on uncertainties for TCS correction of cascade gamma-rays from 134Cs, 5 % relative standard uncertainty, which was obtained from radioactivity analysis of the 134Cs standard source by the efficiency curve method, was assigned for the efficiency curve method of 134Cs. The utilization of a low background gamma-ray spectrometer and the development of an accurate correction method of TCS are required to obtain a smaller uncertainty of the analysis methods.View full abstractDownload PDF (1118K) -
Takao KATO, Yasuhiro SUZUKI, Makoto HANDAArticle type: Technical Papers
2017 Volume 66 Issue 1 Pages 39-48
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESSThe extracted dyes for polyester fibers from 50 black glove textiles, which are commercialized, were analyzed by liquid chromatography/-linear ion-trap tandem mass spectrometry (LC/LIT-MSn). The identification of dyes was carried out using the custom-built database. Thirty kinds of disperse dyes were detected from 50 black polyester fibers. It was found that 5 kinds of disperse dyes on the average were used to dye the textiles with black color and that four kinds of disperse dyes, Disperse Violet 93 : 1, Disperse Orange 288 {Disperse Blue 291 : 1 and an unknown dye [basepeak ion (m/z) = 489, λmax: 590 nm]} were more commonly used for the dying compared with other dyes. The analytical results obtained by LC/LIT-MSn allows the discrimination of 1195 pairs (97.6 %) out of 1225 ones. The discrimination was improved to 99.2 % by the combination of LC/LIT-MSn and microspectrophotometry (MSP), although the discriminate rate was 95.9 % when the MPS method was only used.View full abstractDownload PDF (1662K)
Analytical Reports
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Sakura YOSHII, Akihiro IIJIMA, Masanobu MORI, Hideyuki ITABASHIArticle type: Analytical Reports
2017 Volume 66 Issue 1 Pages 49-54
Published: January 05, 2017
Released on J-STAGE: February 04, 2017
JOURNAL FREE ACCESSNitrogen saturation (N-saturation) is a phenomenon caused when nitrogen is saturated in forest soil, which is input into river water. Our purpose was to estimate the degree of N-saturation in the upstream area of the Kanna River in Gunma Prefecture, which has never been contaminated by industrial wastewater and domestic drainage. Here, we analyzed changes in the concentrations of nitrogen species (NO3−) and coexisting components in the river water and the forest soil. The water and soil samples were collected from nine sampling points between 2015 and 2016. Soil samples collected near the river showed the same levels of metallic element content as those in typical forest soil. This NO3− concentration belongs to "Stage 1" of the four N-saturation stages (Stages 0 – 3). The NO3− concentration in the water samples had very low correlations to the concentrations of co-existed ions. In contrast, the nitrogen content in the soil samples had a positive correlation to Ca, while the detail mechanism on the relationship could not be elucidated in this study. Rather, the NO3− concentration was considered to be strongly affected by air pollution in the metropolitan due to geographical and meteorological factors in Gunma Prefecture. Because this stage is an initial step towards serious adverse effect with N-saturation, the maintenance such as forest thinning will be required in order to inhibit the progress.View full abstractDownload PDF (872K)
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