Pseudo soliton in fluidized beds and its perturbed treatment

The author summarize the recent analysis of a two-fluid model which describes fluidized beds of granular particles. It has been found that near the transition point from stable fluidized beds to unstable ones the two-fluid model is reduced to the KdV equation with small dissipation. The amplitude and the propagating velocity of a pulse of the reduced equation is obtained.Department of Physics, Tohoku University, Sendai 980, Japan. E-mail: hisao@cmpt01.phys.tohoku.ac.jp. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 99, No. 2, pp. 309–314, May, 1994.     

Studies on the effects of imidazole on the peroxyoxalate chemiluminescence detection system for high performance liquid chromatography

The catalytic effect of bases (imidazole, pyridine, Tris and triethylamine) on the peroxyoxalate chemiluminescence (PO-CL) reaction for high performance liquid chromatography (HPLC) was investigated. Imidazole increased PO-CL intensity extraordinarily, whereas the other bases (pyridine, Tris and triethylamine) did not. The peak heights of dipyridamole (coronary vasodilator) obtained using the eluents containing buffers were largest at pH 7.0, a few times less at pH 6.0 and pH 5.0, 100 times less at pH 4.0 and a few hundred times less at pH 3.0. The eluents containing buffers at pH 3, 4, 5, 6 or 7 each with imidazole increased the peak heights by a few to ten times as compared with those without imidazole, and those peak heights were within one order of magnitude. On the other hand, the eluent containing buffer at pH 2 did not affect the peak heights with or without imidazole. Bis(4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl) oxalate (TDPO) alone and bis(2,4-dinitrophenyl)oxalate (DNPO) plus TDPO were recommended to be used against eluents containing buffers of pH 5-7 and pH 3-4, respectively. Dipyridamole and benzydamine hydrochloride (anti-inflammatory drug) were separated on the ODS column and detected by the present system. The detection limits of dipyridamole and benzydamine hydrochloride were 40 amol and 270 fmol, respectively.     

Reversed phase liquid chromatographic determination of organic acids using on-line complexation with copper(II) ion

We describe a simple and sensitive liquid chromatographic method for the analysis of organic acids using on-line complexation with copper(II) ion. Organic acids complexed with copper(II) ion were separated on a reversed-phase C18 column and detected by UV absorption at 240 nm. The copper(II) ion concentration in the mobile phase had a great influence on separation and sensitivity. A mobile phase consisting of 10 mM copper(II) sulfate in 5 mM sulfuric acid (pH 2.3) was used to separate nine organic acids (tartaric, malic, malonic, lactic, acetic, citric, maleic, succinic and fumaric acids). The detection limits of the examined organic acids calculated at S/N = 3 ranged from 0.6 to 100 μM. The detector signal was linear over three orders of magnitude of organic acid concentration. The method successfully measured organic acids in juice and vinegar samples.     

Application of partial-filling capillary electrophoresis using lectins and glycosidases for the characterization of oligosaccharides in a therapeutic antibody

Oligosaccharides in therapeutic recombinant antibodies play important roles in regulation of various biological functions. To monitor the glycosylation profiles of antibody pharmaceuticals in the manufacturing process, a highly sensitive and specific method is required. We extended partial-filling techniques using lectins and exoglycosidases in capillary electrophoresis for the characterization of 8-aminopylene-1,3,6-trisulfonic acid labeled N-linked oligosaccharides derived from the therapeutic antibody rituximab. In the lectin-filling method, Galb1–4GlcNAc-specific Erythrina cristagali agglutinin, a1, 6-linked Fuc-specific Aleuria aurantia lectin and Neu5Aca2–3Gal-specific Maackia amurensis lectin were used. The oligosaccharides migrated through the lectin plug during separation; the changes in separation profiles were observed according to the interaction with the lectins. The glycosidase-filling method allowed rapid digestion as suggested by the electropherograms. Partial-filling CE methods can avoid tedious hands-on procedures such as overnight incubation and optimization reaction condition with lectins and exoglycosidases. Combination of these partial-filling capillary electrophoresis methods makes the characterization of oligosaccharide profiles of therapeutic antibodies easier and faster.     

18O assisted analysis of a γ,δ-epoxyketone cyclization: synthesis of the C16-C28 fragment of ammocidin D

The C16-C28 fragment common to the cytotoxic macrolide ammocidin D has been prepared by a stereospecific 5-exo closure of a γ,δ-epoxyketone followed by a rearrangement to a pyran acetal. The reaction pathway was traced by (18)O labeling of the keto carbonyl and observation of (18)O induced (13)C shifts in the pyran acetal product. NMR data of the synthetic C16-C28 fragment compared favorably to the natural product providing support of the assigned stereochemistry.     

Low temperature thermoelectric properties of Cu intercalated TiSe2: a charge density wave material

Y₂O₃ nanoparticles and nanorods have been firstly synthesized in bulk Ti-Y films prepared by magnetron sputtering on Si (100) substrates at different temperatures. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) are used to characterize the structure, morphology, and composition of the as-synthesized nanoparticles and nanorods. The mechanical properties of the sputtered films are investigated using nanoindentation techniques. The results indicate that both the nanoparticles and nanorods have a pure cubic Y₂O₃ structure resulting from the reaction of Y atoms with the residual O₂ in the vacuum chamber, and are free from defects and dislocations with uniform diameters of about 30 nm. The Y₂O₃ nanoparticles mainly distribute at the grain boundaries of the Ti matrix and the nanorods have lengths ranging from 250 nm to more than 1 μm with the growth direction parallel to the (002) plane. As the growth temperature elevates, the nanoparticles turn to be coarsening while more and longer nanorods are inclined to form. Compared with the Ti film, the TiY films have a remarkable increase in hardness, but do not exhibit expected increase in elastic modulus. Finally, the growth mechanism is also briefly discussed.     

Multiple Coulomb excitation of a 70Ge beam and the interpretation of the 02 + state as a deformed intruder

Electromagnetic properties of the low-lying states in a ⁷⁰Ge nucleus were studied through the multiple Coulomb excitation of a ⁷⁰Ge beam with a ^natPb target. Relative γ-ray intensities were measured as a function of emission angle relative to the scattered projectile. Sixteen E2 matrix elements, including diagonal ones, for 6 low-lying states have been determined using the least-squares search code GOSIA. The expectation values 〈Q ²〉 of 0₁ ⁺ and 0₂ ⁺ states in ⁷⁰Ge are compared with those in ^{72, 74, 76}Ge. Simple mixing calculations indicate that the 0₂ ⁺ states in ⁷⁰Ge and ⁷²Se can be treated as deformed intruder states. It is shown that the deformed intruder becomes the ground state in ⁷⁴Kr. These interpretations of the 0₂ ⁺ states in this region are compared with the potential-energy surface calculations by the Nilsson-Strutinsky model, which allow to interpret the experimental results in a qualitative way from the theoretical point of view. Received: 2 September 2002 / Accepted: 5 November 2002 / Published online: 25 February 2003 RID="a" ID="a"e-mail: sugawara@pf.it-chiba.ac.jp Communicated by D. Schwalm     

Effect of surface covering of lactose carrier particles on dry powder inhalation properties of salbutamol sulfate

The effect of the surface covering of lactose carrier particles on the dry powder inhalation properties of salbutamol sulfate was investigated. Lactose carrier surfaces were covered with sucrose tristearate (J-1803F) by a high-speed elliptical-rotor-type powder mixer (Theta-Composer). In the present study, drug/carrier powder mixtures were prepared consisting of micronized salbutamol sulfate and lactose carriers with various particle surface conditions prepared by surface covering. These powder mixtures were aerosolized by a Jethaler), and the in vitro inhalation properties of salbutamol sulfate were evaluated by a twin impinger. Compared with the powder mixed with uncovered lactose carrier, the in vitro inhalation properties of the powder mixture prepared using the surface covering lactose carrier were significantly different, showing that the in vitro inhalation properties of salbutamol sulfate were improved. In vitro inhalation properties increased with the percentage of J-1803F added. Using this surface covering system would thus be valuable for increasing the inhalation properties of dry powder inhalation with lactose carrier particles.     

169Re的转动带结构研究

利用在束γ谱学方法,通过反应¹⁴⁴Sm(²⁸Si,1p3n)¹⁶⁹Re研究了¹⁶⁹Re的激发态能级结构.实验进行了X-γ符合、γ-γ符合、DCO系数和带内B(M1)/B(E2)比率测量.基于这些测量,建立了组态为π9/2^－[514]的强耦合带和组态为π1/2^－[541]的退耦合带.通过比较¹⁶⁹Re的转动带与邻近奇质子核已知转动带的结构和B(M1)/B(E2)比率,指定了¹⁶⁹Re转动带的组态.实验观测到π9/2^－[514]和π1/2^－[541]转动带的中子AB带交叉的转动频率分别为0.23和0.27MeV.着重讨论了¹⁶⁹Re转动带的中子AB带交叉频率、转动角动量顺排和旋称劈列等,并讨论了奇ARe核转动带结构的系统性