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21.
22.
Determination of cefodizime in biological materials by high-performance liquid chromatography 总被引:1,自引:0,他引:1
Cefodizime (THR-221) is a new semi-synthetic cephalosporin. A high-performance liquid chromatographic method has been developed for the determination of cefodizime in biological materials. A plasma or serum sample was deproteinized with methanol and the resulting methanol eluate was concentrated to a volume of 0.5 ml. Urine and bile samples were diluted with buffer and each diluted sample was filtered. Faeces samples were homogenized and the supernate obtained after centrifugation was filtered. Visceral tissue samples were homogenized, the centrifuged supernate was deproteinized with methanol, and the methanol eluate was concentrated to a volume of 0.5 ml. Aliquots of each preparation were chromatographed on a reversed-phase column with an ion-pair chromatographic technique on a high-performance liquid chromatograph equipped with an UV detector set at 264 nm. The detection limits for cefodizime were 0.1 microgram/ml in plasma or serum, 0.3 microgram/ml in bile, and 0.5 microgram/ml in urine, 0.5 microgram/g in faeces and visceral tissue. This precise and sensitive assay for the determination of cefodizime is described, and its stability in several media is reported. 相似文献
23.
Sensitive, reactive, and hydrophilic fluorogenic reagents for thiols with the benzofurazan skeleton, 4-(N-acetylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (AcABD-F) and 4-(N-trichloroacetylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (TCAcABD-F) have been developed. These reagents reacted with thiols within 10 min at 60 degrees C. AcABD-F and TCAcABD-F themselves do not fluoresce but are strongly fluorescent after the reaction with thiol compounds. The generated derivatives were highly water-soluble, since they dissociated a proton and ionized in the neutral pH region. The derivatives with four biologically important thiol compounds were separated on a reversed-phase HPLC column and detected fluorometrically at 504 nm with excitation at 388 nm. The detection limit attained for homocysteine with AcABD-F was 25 fmol on column (11 nM) (signal-to-noise ratio = 3), and that for glutathione with TCAcABD-F was 45 fmol on column (20 nM). 相似文献
24.
H.?Matsushima T.?Nohira Y.?ItoEmail author 《Journal of Solid State Electrochemistry》2004,8(3):195-200
The effects of a magnetic field (5 T) on crystal orientation and surface morphology were investigated for iron films electrodeposited in ferrous aqueous solution. XRD measurements for the iron films showed that the preferred orientation parallel to the substrate was determined by the current density and not influenced by the magnetic field. By X-ray pole figure measurements, however, the crystal texture of the iron films electrodeposited at 10 mA cm–2 and 30 mA cm–2 was found to be controlled by the magnetic field. That is, the (110) planes were orientated in same direction of the magnetic field vector at angles of 30° and 35° to the direction normal to the substrate plane at 10 mA cm–2 and 30 mA cm–2, respectively. When the morphology was observed by SEM, iron grains at 30 mA cm–2 changed from a triangular pyramid shape at 0 T to a complex star-like shape at 5 T.Presented at the 3rd International Symposium on Electrochemical Processing of Tailored Materials held at the 53rd Annual Meeting of the International Society of Electrochemistry, 15–20 September 2002, Düsseldorf, Germany 相似文献
25.
Seiichi Nakamura Jun Inagaki Tomohiro Sugimoto Yasuyuki Ura Shunichi Hashimoto 《Tetrahedron》2002,58(52):10375-10386
An efficient, highly stereoselective synthesis of the C10–C31 (BCDEF ring) portion of pinnatoxin A has been achieved utilizing tandem double hemiketal formation/intramolecular hetero-Michael addition to construct the 6,5,6-dispiroketal (BCD ring) system and subsequent intramolecular ketalization to form the 5,6-bicycloketal (EF ring) system as key steps. 相似文献
26.
Atsuo Fukuda Hans J. Paus Akira Matsushima 《Zeitschrift für Physik B Condensed Matter》1976,25(3):211-218
Magnetic circular dichroism (MCD) of theA- andB-absorption band region has been obtained at 4.2 K and 50 kG in KI:Ga+, KI:In+, and KI:Sn2+. The MCD spectra indicate the complex nature of these bands more clearly than the absorption spectra themselves do. TheA-band MCD consists in all cases of a positive and a negative part reflecting the structure of the absorption band. TheB-band MCD shows three peaks, two positive peaks at 4.34 and 4.415 eV (4.09 and 4.175 eV) and a negative peak at 4.38 eV (4.125 eV) in KI:Ga+ (KI:In+). TheB-band in KI:Sn2+ consists of a shoulder (b
0) at 3.76 eV and a main band which has at least 5 sub-peaks (b
1~b
5) at 3.821, 3.841, 3.861, 3.880, and 3.895 eV; each of the subpeaks (b
1~b
5) gives a derivative-like MCD.The MCD shape functionf() for the transitiona
1g
2
a
1g
t
1u
has been obtained for one set of parameter values by using the classical Franck-Condon approximation and the Monte Carlo integration method. The result can explain the observed salient features of theB- as well asA-band MCD's, indicating the validity of the Franck-Condon approximation and the interaction mode coordinates. 相似文献
27.
trans-Stilbene, 1, 1-diphenylethylene, and α-methylstyrene were allowed to react with dibenzylmagnesium to form their oligomers in hexamethylphosphortriamide (HMPA). One and two molecules of stilbene and 1, 1-diphenylethylene were incorporated into the magnesium carbon bond, and the carbanions obtained in HMPA were stable in analogy with the anionic living polymer having alkali cation as the gegenion in eithers. Intense coloration was observed during the reaction between α-methylstyrene and dibenzylmagnesium as well as in the case of stilbene and 1, 1-diphenylethylene. The low molecular weight products which were formed after a long time in the reaction between α-methylstyrene and dibenzylmagnesium were found to have no magnesium-carbon bond. It was considered that the cleavage of the propagating chain occurred gradually after the rapid propagation had proceeded to consume the monomer. 相似文献
28.
Susumu Takigawa Masanori Koshimizu Takio Noguchi Tsutomu Aida Seiichi Takami Tadafumi Adschiri Yutaka Fujimoto Akira Yoko Gimyeong Seong Takaaki Tomai Keisuke Asai 《Journal of Radioanalytical and Nuclear Chemistry》2017,314(2):611-615
We synthesized liquid scintillators incorporating ZrO2 nanoparticles for application in neutrinoless double beta decay experiments. ZrO2 nanoparticles of less than 10 nm in size were synthesized with sub- and supercritical hydrothermal methods. The Zr concentrations in the liquid scintillators were determined to be up to 1.4 wt% with inductively coupled plasma analysis, and the liquid scintillators were transparent to scintillation. These results indicate that these methods are applicable for the preparation of liquid scintillators for neutrinoless double beta decay experiments. 相似文献
29.
Observation of bubble layer formed on hydrogen and oxygen gas-evolving electrode in a magnetic field
Hisayoshi Matsushima Takami Iida Yasuhiro Fukunaka 《Journal of Solid State Electrochemistry》2012,16(2):617-623
The evolution of hydrogen and oxygen gasses in a 0.36-M KOH electrolyte was observed in a magnetic field, and the void fraction
was calculated by a hydrodynamic model. Both gasses evolving on a platinum working electrode formed a bubble layer which increased
the ohmic resistance. In addition to natural convection, magnetohydrodynamic (MHD) convection in a magnetic field improved
the electrolytic conductivity by supplying a fresh solution (pumping effect) and removing gas bubbles. The MHD convection
reduced the void fraction of hydrogen gas more than that of oxygen, which can be explained by the poor wettability of the
oxygen evolving electrode. 相似文献
30.
Seiichi Ohta Susumu Inasawa Yukio Yamaguchi 《Journal of Polymer Science.Polymer Physics》2012,50(12):863-869
When a mixture of liquid crystal (LC) and photo reactive monomer is irradiated by UV light, polymerization occurs and LC droplets form through phase separation, producing polymer dispersed LCs (PDLCs). Although size control of LC droplets and reduced amounts of LC in PDLC films are important in applications, precise size control of LC droplets at a low LC fraction has not yet been accomplished. In this study, the phase diagrams of the LC/initial monomer and the LC/polymer during polymerization were used to control LC droplet size at various LC fractions. Both the relative position of the sample in the initial phase diagram and the shift of the phase separation line during polymerization were shown to be important in determining the size of LC droplets. Our results are expected to provide a new strategy for precise size control of LC droplets especially at a low LC fraction range, which would be a great help for PDLC applications. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 相似文献