All issues
Volume 64, Issue 2
Displaying 1-8 of 8 articles from this issue
- |<
- <
- 1
- >
- >|
Annual Topic “Bio” : Reviews
-
Masaru KATOArticle type: Annual Topic “Bio” : Reviews
2015 Volume 64 Issue 2 Pages 77-87
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSMuch attention has been paid concerning the local function of proteins within a cell. Stimuli-responsive nanoparticles containing protein have begun to be used for its analysis. A nanoparticle-encapsulated protein was internalized to a cell, was stored within the cell stably until it received a stimulus, and was released while showing activity within the cell after noninvasive external stimulus. Because these stimuli-responsive nanoparticles allowed us to activate various proteins spatiotemporally, these nanoparticles are promising tools to study the local functions of intracellular proteins. In this review, the latest developments regarding protein-containing nanoparticles have been introduced. Their application to the study of protein function within a cell is also discussed.View full abstractDownload PDF (7462K)
Annual Topic “Bio” : Accounts
-
Hiroshi YUKAWA, Yoshinobu BABAArticle type: Annual Topic “Bio” : Accounts
2015 Volume 64 Issue 2 Pages 89-97
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSQuantum dots (QDs) have excellent fluorescence properties compared to traditional fluorescence probes. Thus, the optical application of QDs is in a rapid expansion to each field of analytical chemistry. In this paper, we described about the application of QDs to regenerative medicine, especially stem cell transplantation therapy. Specifically, labeling technologies of stem cells by QDs composed of semiconductor materials in combination with poly-cationic liposome (Lipofectamine®) or cell-penetrating peptide (octa-arginine) were reviewed. Moreover, in vivo imaging technology of transplanted stem cells in mice by QDs emitting fluorescence in near-infrared region, which could be detected by fluorescence in vivo imaging machines, such as an IVIS imaging system, was reviewed.View full abstractDownload PDF (17339K)
Annual Topic “Bio” : Technical Papers
-
Tomoyuki YASUKAWA, Yuya KIBA, Fumio MIZUTANIArticle type: Annual Topic “Bio” : Technical Papers
2015 Volume 64 Issue 2 Pages 99-104
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSWe fabricated an electrochemical detection system involving redox species flowing in a nitrocellulose membrane incorporated into two plates with both poles and electrodes. We prepared an upper substrate with poles inserted a Pt microelectrode and a Ag/AgCl electrode as well as a bottom substrate with a small pole array and poles that were used as supports of nitrocellulose membranes. The presence of poles allowed a uniform flow of a solution in the membrane and a steady-state oxidation current of hydrogen peroxide. A solution containing different concentrations of glucose was introduced into the device with membranes to be immobilized by glucose oxidase (GOx). Hydrogen peroxide produced through the enzyme reaction in the presence of glucose flowed downstream to give an electrochemical response with the electrode arranged 6 mm away from the GOx immobilization area. Oxidation currents of hydrogen peroxide increased with increasing the concentration of glucose. Thus, an electrochemical detection system of redox species flowing in the membrane indicated the possibility for developing an enzymatic and immunological assay format with electrochemical quantitation.View full abstractDownload PDF (1133K)
Accounts
-
Toshio TAKAYANAGIArticle type: Accounts
2015 Volume 64 Issue 2 Pages 105-116
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSAnalysis methods of equilibrium in an aqueous solution have been developed by capillary zone electrophoresis (CZE) utilizing its separation principle. The equilibrium of interest has been analyzed by affinity capillary electrophoresis (ACE) through the change in the electrophoretic mobility. Coexisting substances including degraded compounds are resolved from the equilibrium species by CZE, and an acid dissociation constant of photo-degradable haloperidol was determined in the presence of the degraded substances. In addition to the classical CZE separation, it has been noticed that gradually generated substances during CZE are resolved from the equilibrium species, and that the generated substances are observed as a leading/tailing signal to the equilibrium species. Slowly generated species from phenolphthalein by the addition of OH− in an alkaline pH solution was resolved from the equilibrium species, and the side reaction to the objective acid-base equilibria was excluded. Thus, two steps of the acid dissociation constants of phenolphthalein were determined by ACE. The acid-base equilibrium of tetrabromophenolphthalein ethyl ester (TBPE) was also analyzed by CZE under the degrading conditions, although the hydrolysis of the ester moiety accompanies with TBPE in acidic pH conditions. The precipitation reaction as a side reaction can also be excluded in the CZE analysis. The low concentration of analyte below its solubility is detected as a usual CZE signal, and the equilibrium of interest can be analyzed. The ion-association constants of dipicrylaminate ion with pairing cations were determined by ACE. Even under precipitating conditions, the precipitate is resolved from the equilibrium species by CZE, and it is dissolved again in the separation buffer. Acid dissociation constants of tetrabromophenolphthalein are determined by ACE under precipitable conditions. It was demonstrated in this study that the utilization of the CZE separation is advantageous on equilibrium analysis by ACE to such reactions as to be degradable and precipitable ones, compared to the ordinary analysis in homogeneous solutions, including potentiometric and photometric titrations.View full abstractDownload PDF (1198K)
Research Papers
-
Toshiko ITAGAKI, Tetsuya ASHINO, Kunio TAKADA, Kazuaki WAGATSUMAArticle type: Research Papers
2015 Volume 64 Issue 2 Pages 117-124
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSIn order to conduct more precise measurements on a flame atomic absorption spectrometer (FAAS) with a continuum light source, the authors investigated a simultaneous internal standard method. For this purpose, an FAAS instrument, equipped with a xenon short-arc lamp as the radiation source and a high-resolution echelle monochromator, was employed. Synthetic mixed solutions of mixed nickel (10 μg mL−1) and iron (500 and 1000 μg mL−1) were prepared so that the determination of nickel in steel samples could be carried out. Neighboring spectrum lines of nickel (Ni I 232.003 nm) and iron (Fe I 232.036 nm) were selected, and their atomic absorbances were simultaneously measured for each test solution and sample solution. The matrix iron was employed as an internal standard element for nickel analysis by FAAS. In the proposed method, any variance of the analytical results in the measurement using a test solution could be reduced; in addition, the physical interference in the FAAS measurement by sulfuric acid coexisting in the sample solution could be removed. The amounts of nickel in steel CRMs were determined by a calibration curve method and the proposed method. Analytical values obtained by the both methods agreed with the certified reference values in the CRMs. However, in six or ten replicate measurements by these methods, the relative standard deviation of the analytical values obtained by the proposed method was lower than that by the calibration curve method. Therefore, the simultaneous internal standard method is very useful for improving the analytical precision in measurements with FAAS. Furthermore, it was effective for correcting any long-term drift of the sensitivity in the experimental system.View full abstractDownload PDF (1047K)
Technical Papers
-
Norio KATOArticle type: Technical Papers
2015 Volume 64 Issue 2 Pages 125-130
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSThis study investigated the combustion conditions for Cr(VI) formation during pulverized coal combustion using three types of furnaces. Cr(VI) compounds can be highly soluble in water, whereas Cr(III) compounds are less soluble. The amount of Cr(VI) in coal ash was measured using the amount of Cr(VI) leached in a leaching solution, with ICP-AES after the separation of Cr(III) by Fe(OH)3 co-precipitation. The results from laboratory drop tube furnace experiments indicated that the amount of Cr(VI) leached from coal ash depended on the temperature of the furnace, the air ratio (amount of air used in combustion to the theoretical air demand), and the O2 concentration in the carrier gas. Since these dependences were similar to those for NOx emission, a two-stage combustion method used as a NOx reducing method was examined by using an experimental furnace with a burner for pulverized coal firing and a coal-fired power plant. The results showed that the amount of leached Cr(VI) decreased along with NOx as the two-stage combustion ratio increased. Low-NOx combustion conditions likely reduced the Cr(VI) formation in the combustion zone.View full abstractDownload PDF (926K) -
Tomoki NAKAO, Takako SUEMATSU, Hiroaki UTSUMI, Toshihiro FURUKAWA, Haj ...Article type: Technical Papers
2015 Volume 64 Issue 2 Pages 131-146
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSFor intensity estimations of the NMR signal, we have proposed the High-Order Estimation Selective Evaluation (HOESE) method. This Method estimates the poles (half-widths, frequencies) and the amplitudes of each signal element included in the NMR signal, and calculates intensity as the sum of these amplitudes. However, the HOESE may obtain a biased estimation value with respect to the parameter under the inhomogeneity of the magnetic distribution. In order to overcome the drawback above, we would like to propose a method in which the Reference Deconvolution Method (RDM) is firstly performed to the observed NMR signal, and the HOESE secondly is applied to the pre-processed NMR signal. Theoretical analysis indicate that the proposed method can obtain approximately an unbiased estimation value of the parameter already mentioned. Computer simulations and experiments show the effectiveness of the proposed method.View full abstractDownload PDF (1058K)
Analytical Reports
-
Natsuhiko SUGIMURA, Asami FURUYA, Takahiro YATSU, Toshimichi SHIBUEArticle type: Analytical Reports
2015 Volume 64 Issue 2 Pages 147-150
Published: February 05, 2015
Released on J-STAGE: March 05, 2015
JOURNAL FREE ACCESSWe tested a practical method for reducing any error in computed 13C-NMR chemical shifts of the halogenated natural product (−)-Napyradiomycin A1. Linear-regression parameters were employed as empirical scaling factors. The DFT (density functional theory) method B3LYP/6 − 311 + (2d,p) with an empirical scaling factor reduced the error of two chlorine attached carbon, from 14.4 to 1.1 ppm, and from 10.8 to 2.4 ppm. This method provide a 1.95 ppm root mean square error and a 0.999 correlation coefficient.View full abstractDownload PDF (477K)
- |<
- <
- 1
- >
- >|