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101.
Koichi Inoue Tasuku Sakamoto Yoshihito Fujita Saya Yoshizawa Maiko Tomita Jun Zhe Min Kenichiro Todoroki Kazuya Sobue Toshimasa Toyo'oka 《Biomedical chromatography : BMC》2013,27(7):853-858
Dexmedetomidine (Dex) is a selective central α2‐agonist with anesthetic properties and has been used in clinical practice for sedation in the intensive care unit (ICU) after operations. In this study, an analytical assay for the determination of Dex in a small amount of plasma was developed for the application to pediatric ICU trials. The quantification of Dex was constructed using the original stable isotope Dex‐d3 for electrospray ionization‐tandem mass spectrometry (ESI‐MS/MS) in the selected reaction monitoring mode. A rapid ultra‐performance liquid chromatography technique was adopted using ESI‐MS/MS with a runtime of 3 min. Efficacious concentration levels (50 pg/mL to 5 ng/mL) could be evaluated using a very small amount of plasma (10 μL) from patients. The lower limit of the quantification was 5 pg/mL in the plasma (100 µL). For sample preparation, a solid‐phase extraction was used along with the OASIS‐HLB cartridge type. Recovery values ranged from 98.8 to 100.3% for the intra‐ [relative standard deviation (RSD), 0.9–1.3%] and inter‐ (RSD, 0.9–1.5%) day assays. A stable test had recovery values that ranged from 97.8 to 99.7% with an RSD of 1.0–1.9% for the process/wet extract, bench‐top, freeze–thaw and long‐term tests. This method was used to measure the Dex levels in plasma from pediatric ICU patients. In the clinical ICU trial, the small amount of blood (approximate plasma volume, 200 μL) remaining from blood gas analysis was reused and targeted for the clinical analysis of Dex in plasma. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
102.
103.
The preparation, characterization and ammonia and water adsorption properties of edge-rich carbon nanofibers (CNFs) were studied, including platelet CNFs (PCNFs) and cup-stacked CNFs (CSCNFs). Since PCNFs and CSCNFs have many chemically active exposed edges, functionalization by oxidizing the edges was carried out by ozone stream and by nitric acid. Transmission electron microscopy, N2 adsorption isotherms and temperature-programmed desorption analysis showed that the nitric acid treatment partly destroyed the graphite structure of the PCNFs and created acid functional groups and micropores, whereas the ozone treatment created functional groups without damaging the structure. Ammonia adsorption isotherms clarified that NH3 adsorption on PCNFs and CSCNFs occurred mainly on oxygen-containing groups, whereas the adsorption on activated carbon fibers (ACFs) occurred on both oxygen-containing groups and the carbon surface without the functional groups, and the CSCNFs showed larger amounts of adsorbed ammonia compared to the PCNFs. Especially at a relatively low pressure range (<0.2 atm), the PCNFs/CSCNFs/ACFs showed the same ammonia adsorption mechanism; that is, the one-to-one interaction between oxygen atoms in the functional groups and hydrogen atoms in ammonia molecules. In addition, the adsorption on the ACFs appeared to occur mainly by interaction with the carbon surface at relatively high pressure (0.3–1.0 atm). Our experimental results and previous findings suggest that NH3 adsorption on PCNFs is due mainly to NH…O hydrogen bonding between oxygen-containing groups and ammonia rather than to chemical bonding. 相似文献
104.
Hisanao Yamamoto Akira Fujita Miyuki Harada Mitsukazu Ochi 《Molecular Crystals and Liquid Crystals》2014,588(1):41-50
A liquid crystalline epoxy resin (LCE) having α-methylstilbene as a mesogenic unit and an ethylene-oxy unit as a spacer (DGE(C2-MS-C2)) was synthesized and characterized. DGE (C2-MS-C2) has a lower melting point (MP) compared to the diglycidylether of 4,4′-dihydroxy-α-methylstilbene (DGEDHMS). The curing of DGE (C2-MS-C2) with diaminodiphenylethane (DDEt) in a mesophase generated a liquid crystalline (LC) network, which have a more highly layered structure than DGEDHMS. The LC network showed extensively large fracture energy on a tensile test. Introducing spacers outside the mesogen unit promotes the mesogen unit to form a highly ordered structure, which enhances the versatility of LC epoxy resins. 相似文献
105.
106.
M. Igarashi K. KakimotoT. Hayashida Y. HanadaS. Fujita K. MoritaN. Nakamura S. HanyuY. Sutoh H. KutamiY. Iijima T. Saitoh 《Physica C: Superconductivity and its Applications》2010,470(20):1230-1233
We have studied a hot-wall heating system to produce GdBa2Cu3Oy (GdBCO) films with large critical currents (Ic) at a high production rate by a pulsed-laser-deposition (PLD) method. GdBCO films fabricated at a production rate of 30 m/h under the optimized conditions, especially a distance of 95 mm between the target and the substrate (T–S), exhibited high critical current densities (Jc) of about 3 MA/cm2 and Ic over 300 A at a thickness of 1–2 μm. Furthermore, long GdBCO tapes prepared by repeated depositions at each tape-passing speed of 80 m/h showed uniform Ic distribution along the longitudinal direction, because the hot-wall system enabled to stabilize temperature within a few degrees at 800 °C. A 170 m long tape with Ic over 600 A was successfully fabricated at a production rate of 16 m/h using a laser power of 360 W. 相似文献
107.
Radiation-induced polymerization and pressure-volume (P-V) measurements of acrylonitrile (AN) were studied up to 8000 kg/cm2 in the temperature range of 6–72°C. P-V isotherms of AN have several small breaks, A phase diagram of AN was obtained from the breaking pressures and temperatures. Liquid phases were named LI, LII, and LIII, from low to high pressure. The polymerization behavior and volume contraction on polymerization changed in LI, LII, and LIII. The difference in entropy between original and activated states decreased with increasing pressure at the same phase, but increased with phase change in LI to LII and LII to LIII. It was concluded from these results and from IR data on PAN that molecular packing of AN in liquid changed in LI, LII, and LIII. In LII and LIII, AN molecules aligned in a less suitable geometry for polymerization than in LI. 相似文献
108.
T. Fujita 《SAR and QSAR in environmental research》2013,24(1-2):77-88
A series of our SAR and QSAR studies of synthetic moulting hormone agonists, dibenzoylhydrazines (DBH), exhibiting insecticidal/larvicidal activity are reviewed in this article. We prepared a number of analogues where various substituents are introduced into the two benzene rings of DBH and measured their biological activity using various biological systems. Larvicidal activity was against larvae of the rice stem borer Chilo suppressalis and the moulting hormone activity was in terms of the stimulation of N-acetylglucosamine incorporation in a cultured integument system of the same insect species. Binding affinity to the ecdysone receptor was assayed with intact Sf-9 cell lines in which the ADME processes are negligible as well as using receptor proteins obtained by in vitro translation of the responsible cDNA cloned from cell-free preparation of integumentary tissue of C. suppressalis. Variations in the biological activity indices were either correlated between two types of activity or correlated using physicochemical molecular and substituent parameters in terms of the classical QSAR. Comparisons among correlations and with recently revealed X-ray crystallographic findings clearly indicate the physicochemical meaning of parameters significant in the correlation equations to help understanding molecular mechanism of the moulting hormonal action. 相似文献
109.
Unsaturated nitriles have been synthesized from trisubstituted olefins via ene-type chlorination and regioselective substitution with cyanide ion followed by double bond migration. 相似文献
110.
Masami Sakamoto Kazuya Yoshiwara Fumitoshi Yagishita Wataru Yoshida Takashi Mino Tsutomu Fujita 《Research on Chemical Intermediates》2013,39(1):385-395
The irradiation of methyl 2- and 3-chromonecarboxylate in the presence of various alkenes afforded cyclobutane type adducts, whose structures were established by X-ray structural analysis. Methyl 2-chromonecarboxylate showed higher photochemical reactivity than methyl 3-chromonecarboxylate, in which endo adducts were yielded as major products. 相似文献