Efficient method for large-scale preparation of two components H and I of Sg-6 saponins from whole seeds of wild soybean (Glycine soja Sieb. and Zucc.)

New saponin components, Sg-6 saponins, have been recently reported from the seeds of wild soybean (Glycine soja) which may have specific health benefits. To evaluate the possible health benefits, a large amount of Sg-6 saponins are needed, but general group A acetyl saponins and new Sg-6 saponins are eluted in overlapping peaks by ordinal preparative high-performance liquid chromatography and/or open column methods. A new method is proposed in this report. This method includes (1) deacetylation of group A acetyl saponins in alkali condition with KOH, (2) precipitation of Sg-6 saponins in acid condition with HCl, (3) recovery of Sg-6 saponins with aqueous methanol from the precipitate, and (4) elution of Sg-6 saponins by preparative reverse-phase open column. With this method, from 450?g of wild soybean whole seed powder, about 1?g of Sg-6 saponins (mixture of six components) was clearly separated from other saponins with 61% recovery.     

Development of novel fast-disintegrating tablets by direct compression using sucrose stearic acid ester as a disintegration-accelerating agent

It was attempted to produce novel furosemide (FS) fast-disintegrating tablets by direct compression. The combination of FS, microcrystalline cellulose, croscarmellose sodium and xylitol was used as the basic formulation, and sucrose stearic acid ester (SSE) was chosen as an additional additive. The tablets with SSE were prepared by the simple addition of SSE, using a lyophilized mixture of FS and SSE or using a FS/SSE mixture obtained by evaporation of their ethanol solution. Only the tablets, produced using the FS/SSE mixture obtained by organic solvent (ethanol) evaporation, showed hardness of more than 30 N and a disintegration time of less than 20 s, which were the properties suitable for fast-disintegrating tablets. These properties were considered to result from well-mixed and fine-powdered SSE and FS.     

Purification by centrifugal partition chromatography of amphiphilic compounds, glycolipids and pseudo-glycolipids synthesized by using cells

Centrifugal partition chromatography (CPC) was applied to separate amphiphilic glycolipids and pseudo-glycolipids synthesized by using cells. Neutral and acidic lipid fractions were isolated by CPC under suitable conditions respectively. Separation of neutral lipid, Gb3-type and Gb4-type oligosaccharide synthesized by using cells, was performed with a two-phase solvent system composed of chloroform-methanol-water at a volume ratio of 5:6:4. On the other hand, separation of acidic lipid, GM3-type oligosaccharide synthesized by using cells, and ganglioside extracted from rat brain were performed with a two-phase solvent system composed of butanol-ethanol-1% acetic acid at a volume ratio of 4:1:5. 8.3mg of Gb3 analogue, 5.1mg of Gb4 analogue, and 19.5mg of GM3 analogue were purified from 3.2l of culture medium obtained by incubation of African green-monkey kidney (Vero) cells with 50 microM n-dodecyl beta-lactoside using CPC.     

The movement of a water droplet on a gradient surface prepared by photodegradation

A hydrophobic to hydrophilic gradient surface was prepared using the tuned photodegradation of an alkylsilane self-assembled monolayer (SAM) using irradiation of vacuum ultraviolet light (wavelength=172 nm). The water contact angle on the photodegraded SAM surface was adjusted using the intensity and time photoirradiation parameters. The formation of a gradient was confirmed by fluorescent labeling. The water drop moved from the hydrophobic to hydrophilic surface with a velocity that depended on the gradient. The higher the gradient, the faster the water moved. For the first time, we have prepared a gradient surface using photodegradation where the movement of a water drop was regulated by the degree of gradation. Considering that the photodegradation technique can be applied to various surfaces and to lithography, this technique will be useful for various material surfaces.     

Influence of pectins on preparation characteristics of lactoferrin bioadhesive tablets

For the treatment of chronic inflammation in the oral cavity, we attempted to develop bioadhesive tablets of bovine lactoferrin (B-LF). Pectin was used as a bioadhesive polymer, and the influence of the degree of esterification and the molecular weight of pectins on the characteristics of B-LF tablets were investigated. Concerning bioadhesive force, a tendency increasing the value according to increase of the esterification of the pectin was confirmed. Sustained release of B-LF from the tablets was observed as the esterification increased, and a possibility for prediction of the time required to release 50% of B-LF by using the equation given by the degree of esterification and the logarithm of the molecular weight was suggested. Pectin cross-linked with Ca(2+) (Ca-PC) was also used for the preparation of the B-LF tablets. Prolonged release of B-LF from the tablets was observed as the Ca(2+) in Ca-PC increased. Our findings suggest that pectin with a high degree of esterification is suitable as a bioadhesive polymer since high bioadhesive force and sustained release are shown. Furthermore, a possibility that the B-LF release could be controlled by adjusting the Ca(2+) concentration in Ca-PC was suggested.     

Water-Nafion equilibria. absence of Schroeder's paradox

Water-Nafion phase equilibria and proton conductivities were measured in two ways. First, Nafion was in contact with saturated water vapor. Second, Nafion was in contact with liquid water at the same temperature. At 29 degrees C, for preboiled, vapor-equilibrated Nafion exposed to water with an activity = 1 and air pressures ranging from 0 to 0.96 bar, the water content was lambda = 23 +/- 1 mol H(2)O/mol SO3-. For the preboiled, liquid-equilibrated membrane, lambda = 24 +/- 2. At 100% relative humidity (RH), the water content of preboiled Nafion decreased as the temperature rose from 30 to 80 degrees C but did not recover its initial water content when the temperature returned to 30 degrees C. The water content of predried Nafion at 1 atm and 30 degrees C was lambda = 13.7 +/- 0.2 when vapor-equilibrated and lambda = 13.1 +/- 0.5 when liquid-equilibrated. A Nafion membrane originally boiled in water had much higher liquid- and 100% RH vapor-equilibrated proton conductivities than the same membrane originally dried at 110 degrees C with a RH less than 2%. The liquid-equilibrated and 100% RH vapor-equilibrated membrane conductivities were the same when the membrane had the same thermal history. The conductivity data was fit to a model, and the water content was determined at different temperatures. The predried membrane water content increased with temperature, and the preboiled membrane's water content changed slightly with temperature. Both water sorption and proton-conductivity data do not exhibit Schroeder's paradox. These studies and previous results suggest that Schroeder's paradox is resolved when attention is given to the thermal history of the absorbing polymer.     

Linear and nonlinear inversion schemes to retrieve collision kernel values from droplet size distribution change

This study presents an attempt to retrieve collision kernel values from changes in the droplet size distribution due to collision growth. Original linear and nonlinear inversion schemes are presented, which use the simple a priori assumption that the total collision rate is given by the sum of the gravitational and turbulent contributions. Our schemes directly handle binned (discretized) size distributions and, therefore, do not require any assumptions on distribution functional forms, such as the self-similarity assumption. To validate the schemes, three-dimensional direct numerical simulation (DNS) of colliding droplets in steady isotropic turbulence is performed. In the DNS, air turbulence is calculated using a pseudo-spectral method, while droplet motions are tracked by the Lagrangian method. Comparison between the retrieved collision kernels and the collision kernels obtained directly from the DNS show that for low Reynolds number flows both the linear and nonlinear inversion schemes give good accuracy. However, for higher Reynolds number flows the linear inversion scheme gives significantly larger retrieval errors, while the errors for the nonlinear scheme remain small.     

Rebirth of a dead Belousov-Zhabotinsky oscillator

Long time behaviors of the Belousov-Zhabotinsky (BZ) reaction are experimentally analyzed in a closed reactor. The amplitude of the oscillation is suddenly damped after about 10 h. After about 5-20 h, the dead oscillator is suddenly restored with nearly the same amplitude as before it stopped its oscillation for certain values of the concentrations of sodium bromate and malonic acid (MA). With the other domains of the concentrations, the oscillator simply damps and never restores its oscillation. The phase diagram of the different types of damping behaviors as a function of the concentrations is obtained.     

Synergetic effects of double laser pulses for the formation of mild plasma in water: toward non-gated underwater laser-induced breakdown spectroscopy

We experimentally study the dynamics of the plasma induced by the double-laser-pulse irradiation of solid target in water, and find that an appropriate choice of the pulse energies and pulse interval results in the production of an unprecedentedly mild (low-density) plasma, the emission spectra of which are very narrow even without the time-gated detection. The optimum pulse interval and pulse energies are 15-30 μs and about ~1 mJ, respectively, where the latter values are much smaller than those typically employed for this kind of study. In order to clarify the mechanism for the formation of mild plasma we examine the role of the first and second laser pulses, and find that the first pulse produces the cavitation bubble without emission (and hence plasma), and the second pulse induces the mild plasma in the cavitation bubble. These findings may present a new phase of underwater laser-induced breakdown spectroscopy.