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Volume 64, Issue 11
Displaying 1-5 of 5 articles from this issue
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Annual Topic “Bio” : Accounts
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Michio NIWANO, Ayumi HIRANO-IWATAArticle type: Annual Topic “Bio” : Accounts
2015 Volume 64 Issue 11 Pages 793-800
Published: November 05, 2015
Released on J-STAGE: December 09, 2015
JOURNAL FREE ACCESSWe are investigating reactions at Si surfaces and interfaces using infrared spectroscopy in the multiple internal reflection geometry (MIR-IRAS). This technique, in which infrared light beams penetrate a Si crystal wafer internally while reflecting many times, enables us to monitor surface reactions with a quite high surface sensitivity. Since Si surfaces can be observed from inside, we can monitor chemical processes at Si surfaces under various environments. In this review, our MIR-IRAS approaches for the label-free detection of biomolecular interactions are presented. In our MIR-IRAS method, by analyzing IR absorption signals we can detect any structural changes induced by the biomolecular interactions. MIR-IRAS is applicable to in situ real-time monitoring of versatile samples including DNA, proteins, and living cells, regardless of the molecular size and state of the samples.View full abstractDownload PDF (1649K)
Annual Topic “Bio” : Research Papers
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Mao HONDA, Nobuyuki KITAJIMA, Tomoko ABE, Tomonari UMEMURA, Akiko HOKU ...Article type: Annual Topic “Bio” : Research Papers
2015 Volume 64 Issue 11 Pages 801-810
Published: November 05, 2015
Released on J-STAGE: December 09, 2015
JOURNAL FREE ACCESSPteris vittata L. is known as an arsenic hyper-accumulator. To understand the tolerance mechanism, this study investigated the speciation and distribution of chromium accumulated in fern using synchrotron-radiation X-ray fluorescence analysis. The plants were separately treated with K2Cr2O7 and CrCl3·H2O in a hydroponic system. The chemical speciations of chromium and sulfur in the fern were carried out by X-ray absorption near edge structure (XANES) analysis; the elemental distributions in their tissues were visualized by micro-XRF imaging. Chromium was highly accumulated in the roots. μ-XANES and XANES indicated that highly toxic Cr(VI) was reduced Cr(III) as less-toxic Cr(III). The fern-cultivated Cr(III) was accumulated as Cr(III). The chemical speciation of sulfur showed that the ratio of S(-II) compounds, such as glutathione (GSH) and cysteine in the roots, increased when was treated with Cr(VI) and Cr(III). This result demonstrated that sulfur had a certain function in the detoxification process of P. vittata L.View full abstractDownload PDF (1947K)
Accounts
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Yoshinori INOUEArticle type: Accounts
2015 Volume 64 Issue 11 Pages 811-819
Published: November 05, 2015
Released on J-STAGE: December 09, 2015
JOURNAL FREE ACCESSThe design factors for chelating resins were evaluated in detail using a chromatographic method to improve the complexation abilities, the adsorption/desorption equilibrium and element selectivities on chelating resins. The adsorption properties on the chelating resins were drastically improved by adopting a hydrophilic base matrix and a spacer arm. A good correlation was obtained between the retention factors of rare-earth elements and the stability constants of the ligand on the chelating group immobilized. In consideration of these results, novel polyaminocarboxylic acid-type chelating resins were designed. They were synthesized by partial carboxymethylation of oligo-/polyethyleneimine that was immobilized onto the hydrophilic base matrix. Further, an unique element exclusion mechanism was added by introducing positive sites into the ligands. Consequently, the adsorption pH range was expanded by introducing ligands having a multidentate ligand, and alkaline and alkaline earth elements were scarcely retained. On the other hand, the recoveries under acidic conditions for molybdenum and vanadium, which form oxo-acid in water, were reinforced by the ion-exchange interaction with the positive site. These chelating resins were applied to the solid-phase extraction of trace metal elements in environmental water and biological fluid, and the target metal elements could be effectively extracted without any interferences of coexisting elements, such as alkaline and alkaline earth elements. Furthermore, chelate fiber was developed by a wet-spining method mixed with rayon and a macromolecule polyaminocarboxylic acid compound. However, despite the mixed spining into rayon, the element adsorption characteristics on the polyaminocarboxylic acid-type chelating fiber mentioned above was completely preserved. These chelating materials having unique element adsorption characteristics in this studies will contribute to improving of the measurement accuracy and precision in the element analyses.View full abstractDownload PDF (1190K) -
Akira KOTANI, Fumiyo KUSU, Hideki HAKAMATAArticle type: Accounts
2015 Volume 64 Issue 11 Pages 821-833
Published: November 05, 2015
Released on J-STAGE: December 09, 2015
JOURNAL FREE ACCESSLiquid Chromatography with electrochemical detection (LC-ECD) systems by means of a variety of voltammetric reactions have been developed as a sensitive, selective, and accurate method for determining bioactive compounds in plasma. Capillary LC-ECD (CLC-ECD) utilizing voltammetric oxidation on a glassy carbon electrode was applicable to determine attomole levels of flavonoids that have antioxidant activities. A boron-doped diamond (BDD) electrode was used to provide sensitive CLC-ECD for determining femtomole levels of polymethoxyflavones (PMFs) that were difficult to be oxidized on a carbon electrode. Voltammetric acid sensing by the means of reducing 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) was applied to determine electro-inactive acid compounds, such valproic acid and free fatty acids (FFAs), and thus enabling one to detect valproic acid and FFAs without derivatization by HPLC-ECD. Moreover, voltammetric base sensing by the means of oxidizing trolox was applied to determine theophylline in plasma. In conclusion, the present HPLC-ECD systems characterized by sensitivity and selectivity are powerful analytical methods for determining plasma bioactive compounds using a small blood sample (about 10 μL). Additionally, the present HPLC-ECD systems are useful to examine concentration-time profiles of bioactive compounds and determine pharmacokinetic parameters in rat and/or human blood.View full abstractDownload PDF (1062K)
Research Papers
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Yoshiko NAGATA, Yurie ANAN, Hideko KANAZAWAArticle type: Research Papers
2015 Volume 64 Issue 11 Pages 835-844
Published: November 05, 2015
Released on J-STAGE: December 09, 2015
JOURNAL FREE ACCESSWe have studied possible differences of bioavailability between single-drugs and antihypertensive combination tablets of amlodipine besylate. The elution behaviors of four kinds of combination tablets were investigated using the dissolution test, and the formulation properties were studied using 3DX analysis with high-resolution X-ray and hardness measurements. The two components in combination tablets could be analyzed within 4 min using ultra-high-performance liquid chromatography (UHPLC). In the four combination tablets used in this study, elution behaviors of amlodipine besylate were the same as that of the single-drug. In 3DX analysis of these tablets, it was possible to observe the thickness of the coating and the particle size distribution. The data obtained in the present study are of use from clinical sites because there is seldom any information about comparisons of single-drug with a combination tablet.View full abstractDownload PDF (1374K)
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