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1.
Quantitative Detection for Porphyromonas gingivalis in Tooth Pocket and Saliva by Portable Electrochemical DNA Sensor Linked with PCR 下载免费PDF全文
Keiichiro Yamanaka Shinichi Sekine Takahiro Uenoyama Masahiro Wada Tomohiko Ikeuchi Masato Saito Yoshinori Yamaguchi Eiichi Tamiya 《Electroanalysis》2014,26(12):2686-2692
Here, a quantitative electrochemical analysis of periodontal bacteria in gingival crevicular fluid (GCF) and saliva by direct polymerase chain reaction (PCR) is presented. The electrochemical measurement was performed by mixing with PCR products and electrochemical indicator (bisbenzimidazole trihydrochloride). The peak current of indicator is reduced due to slower diffusion when the dye intercalates into the amplified DNA, and the degree of reduction in the peak current is correlates with the quantity of amplified DNA. Therefore, a quantitative analysis is possible by using our electrochemical method at the end point of PCR. In the GCF testing, The number of Porphyromonas gingivalis (Pg) detected by our electrochemical method at the end point of PCR were almost same compared with that were calculated by the conventional method of quantitative real? time PCR. In the saliva testing, the relationship between number of Pg in saliva and average pocket depth, and age‐dependence were also clearly observed. Since the saliva sample is obtained in a non‐invasive manner, this method is useful for the primary screening of periodontal disease. Moreover, our detection method is simple and uses a hand‐held potentiostat making it suitable for development of an on‐site periodontal diagnosis system. 相似文献
2.
Keiichiro Ishikawa Nobuyasu Hanari Yoshitaka Shimizu Toshihide Ihara Akira Nomura Masahiko Numata Takashi Yarita Kenji Kato Koichi Chiba 《Accreditation and quality assurance》2011,16(6):311-322
Purity assay of high-purity materials (HPMs) of phthalic acid esters (PAEs) was carried out by means of a mass balance method.
In this method, chromatographic methods such as gas chromatography-flame ionization detector (GC-FID) and/or high-performance
liquid chromatography (HPLC) in combination with other methods such as Karl-Fischer (KF) titration and vacuum evaporation
(VE) were applied. The sum of the impurities estimated by these methods allowed the estimation of the purity of the main component
by difference. Seven PAEs with varying side chain structures and levels of impurities were analysed on a systematic way in
which impurities were classified into several groups in terms of their abundance, availability of qualitative information
and availability of authentic compounds, etc. The absolute quantity of each impurity was determined by GC-FID and/or HPLC
based on the calibration made by the authentic compounds of impurities whenever available. The purities in mass fraction of
these PAEs were certified at the National Metrology Institute of Japan (NMIJ), and the PAEs were registered as primary reference
materials playing an essential role in linking the metrological traceability of the Japan Calibration Service System (JCSS)
to the International System of Units (SI). 相似文献
3.
Yoshida Keiichiro Ishizuka Tomohiro Mizushima Chiharu Nishidate Izumi Kawauchi Satoko Sato Shunichi Sato Manabu 《Optical Review》2015,22(2):374-384
Optical Review - To evaluate multi-spectral images of the absorption and scattering properties in the cerebral cortex of rat brain, we investigated spectral reflectance images estimated by the... 相似文献
4.
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Theoretical progress in the research of photoinduced phase transitions is reviewed with closely related experiments. After a brief introduction of stochastic evolution in statistical systems and domino effects in localized electron systems, we treat photoinduced dynamics in itinerant-electron systems. Relevant interactions are required in the models to describe the fast and ultrafast charge-lattice-coupled dynamics after photoexcitations. First, we discuss neutral-ionic transitions in the mixed-stack charge-transfer complex, TTF-CA. When induced by intrachain charge-transfer photoexcitations, the dynamics of the ionic-to-neutral transition are characterized by a threshold behavior, while those of the neutral-to-ionic transition by an almost linear behavior. The difference originates from the different electron correlations in the neutral and ionic phases. Second, we deal with halogen-bridged metal complexes, which show metal, Mott insulator, charge-density-wave, and charge–polarization phases. The latter two phases have different broken symmetries. The charge-density-wave to charge–polarization transition is much more easily achieved than the reverse transition. This is clarified by considering microscopic charge-transfer processes. The transition from the charge-density-wave to Mott insulator phases and that from the Mott insulator to metal phases proceed much faster than those between the low-symmetry phases. Next, we discuss ultrafast, inverse spin-Peierls transitions in an organic radical crystal and alkali-TCNQ from the viewpoint of intradimer and interdimer charge-transfer excitations. Then, we study photogenerated electrons in the quantum paraelectric perovskite, SrTiO3, which are assumed to couple differently with soft-anharmonic phonons and breathing-type high-energy phonons. The different electron–phonon couplings result in two types of polarons, a “super-paraelectric large polaron” with a quasi-global parity violation, and an “off-center-type self-trapped polaron” with only a local parity violation. The former is equivalent to a charged and conductive ferroelectric domain, which greatly enhances both the quasi-static electric susceptibility and the electric conductivity. Finally, we outline the development of time-resolved X-ray diffraction experiments, which directly accesses the dynamics of electronic, atomic and molecular motions in photoexcited materials. They are extremely useful when a three-dimensional structural long-range order is established and changes the symmetry. 相似文献
6.
An efficient NIS-promoted guanylation reaction is described. This procedure allows the guanylation of primary and secondary amines through the reaction with di-Boc-thiourea and di-Boc-S-methylisothiourea, respectively. We demonstrated that the use of NIS compares favorably with existing methods and is an attractive alternative to heavy metal or Mukayama’s reagent activation. 相似文献
7.
8.
Keiichiro Yoshida Toshiaki Yamamoto Tomoyuki Kuroki Masaaki Okubo 《Plasma Chemistry and Plasma Processing》2009,29(5):373-386
A pilot-scale pulse corona induced plasma chemical process (PPCP) reactor for controlling gas-phase dioxins and NO
x
simultaneously is installed in a garbage incineration plant. The flow rate of the sampled flue gas is 5,000 Nm3/h (N: standard state) in maximum at the PPCP reactor, which consists of 22 wire-cylinder electrodes and is energized by a
50 kW nanosecond pulse high voltage generator. With an applied plasma energy density of 2.9–6.1 Wh/Nm3, the decomposition efficiency for dioxins is 75–84% based on TEQ (toxic equivalents); the conversion efficiency of NO to
NO2 is ~93% at maximum. The flue gas treated by the PPCP reactor is introduced at a rate of 50 Nm3/h to a wet-type chemical reactor, which uses an aqueous solution of sodium sulfite (Na2SO3). More than 90% of NO
x
is reduced to nitrogen, with negligible byproducts such as NO2
− or NO3
− ions left in the solution. 相似文献
9.
10.
Karen Amirbekyan Justine Mansot Keiichiro Ohara Shiraz A. Markarian Jean-Jacques Vasseur Michael Smietana 《Tetrahedron letters》2018,59(3):295-298
Structurally distinct guanidinium derivatives were evaluated for their ability to interact non-covalently with various nucleic acid sequences. Among the evaluated derivatives, 4-[(pyrene-1-ylmethyl)amino]butyl] guanidinium (pbg) was found to demonstrate strong excimer emission upon nucleic acid addition and high levels of discrimination between ds- and ss-DNA. The intensity of excimer emission proved to be dependent on the length of the linker probe as well as the oligonucleotide length and sequence. In particular, G-quadruplex prone structures were found to induce the highest excimer emissions among all nucleic acids tested. 相似文献