Occurrence of 24(E)-ethylidene sterols in two solanaceae seed oils and rice bran oil

The occurrence of two 24 (E)-ethylidene sterols, fucosterol and 28-isocitrostadienol, in the unsaponifiable matters of two Solanaceae seed oils fromDatura stramonium andCapsicum annuum, and rice bran oil from the seeds ofOryza sativa (Gramineae) was demonstrated by their isolation or by gas liquid chromatography. AlthoughZ-isomers of the above two 24-ethylidene sterols, 28-isofucosterol and citrostadienol, are a frequent occurrence in higher plant materials including some Solanaceae seed oils and rice bran oil, the report might be the second instance of the unambiguous demonstration of the occurrence of the 24(E)-ethylidene sterols in higher plants.     

Positional and fatty acid specificities of Geottichum candidum Upases

Geotrichum candidum ATCC34614 produces a major (I) and threeminor (II, HI and TV) forms of lipase with similar molecularmasses, but different positional and fatty acid specificities.The major and one of the minor (II) forms were confirmed tocleave both the inside and outside ester bonds of triolein indiscriminately.The non-positional specificity was also retained on l,3-dipalmitoyl-2-oleoyl-glycerol(POP) hydrolysis. In contrast, the remaining two forms (IIIand IV) showed unusual positional specificity; they cleavedthe inside (2-position) ester bond of triolein at nearly twicethe rate of cleavage at the l(3)-position. The preference forthe inside ester bond was increased upon POP hydrolysis.     

High-Strength Mica-Containing Glass-Ceramics

Glass-ceramics containing barium–mica in the system Ba_0.5 Mg₃ (Si₃AIO₁₀)F₂–2MgO · 2Al₂O₃· 5SiO₂–Ca₃ (PO₄)₂ are two to three times stronger than conventional mica-containing glass-ceramics. Moreover, the barium-mica glass-ceramics are easier to machine, as confirmed by a drilling test using conventional steel tools. Such mechanical properties are attributable to the microstructure of the barium–mica glass-ceramics. Very fine, interlocking mica crystals are precipitated in the glass, and a crack-deflection mechanism is observed by scanning electron microscopy.     

Residual stress estimation of a silicon carbide-Kovar joint

Residual stress of silicon carbide and Kovar is calculated using the elasto-plastic method and its validity is checked by the four-point bending test. Silicon carbide and Kovar (Fe-27% Ni-7% Co) are diffusion bonded using Al-10% Si alloy clad on a pure aluminium sheet at 883 K and 4.9 MPa under a vacuum condition. The non-linear structure analysis program (ADINA) is used for the stress estimation. It is found by the calculation that the maximum tensile stress, about 170 MPa, is generated in the silicon carbide close to the interlayer. In the bending test, the fracture of the joint is found to occur from the point where the maximum calculated tensile stress is generated, and the bending strength of the joint is 113 MPa. It becomes clear that the calculated stress and the measured strength of the joint is nearly equal to the strength of the silicon carbide itself (280 MPa). Therefore, it can be concluded that the stress estimation in this method indicates a good approximation of the practical residual stress of the joint.     

Interaction of dyes with chitosan derivatives

The states of water in N-acylated, both aliphatic and aromatic, chitosan gels were investigated by DSC technique. The amounts of two states of water, freezable and nonfreezable water, were found to depend on the chemical and physical structure of the gels. The interaction between these hydrophobic gels and the dyes which have been designed and prepared to carry the ionic, hydrophilic, and hydrophobic nature was determined in detail. The dyes having ? OH, ? N(C₄H₉)₂, and naphthalene nucleus show a remarkable increase of the equilibrium sorption to compare with that of methyl orange. The contribution of the electrostatic, hydrophobic, and hydrogen bonding interaction in the sorption was discussed. The predominant contribution of the hydrophobic interaction in the systems of butyl orange/N-octanoyl chitosan gels has been made clear by means of the temperature dependence of the sorption.     

On non-Newtonian flow past a sphere

The approximate solutions for flow of and Ostwald-de Waele fluid past a sphere at R_e·0 = 60 and 1 ? n ? 0·8 are obtained by the use of an extended method of moments. As n decreases, (1) friction drag decreases, (2) pressure drag increases for flow past a blunt body, (3) total drag increases for flow past a sphere, (4) wake length increases for flow past a sphere, (5) separation point moves forward for flow past a sphere.     

Effect of surface properties of silica nanoparticles on their cytotoxicity and cellular distribution in murine macrophages

Surface properties are often hypothesized to be important factors in the development of safer forms of nanomaterials (NMs). However, the results obtained from studying the cellular responses to NMs are often contradictory. Hence, the aim of this study was to investigate the relationship between the surface properties of silica nanoparticles and their cytotoxicity against a murine macrophage cell line (RAW264.7). The surface of the silica nanoparticles was either unmodified (nSP70) or modified with amine (nSP70-N) or carboxyl groups (nSP70-C). First, the properties of the silica nanoparticles were characterized. RAW264.7 cells were then exposed to nSP70, nSP70-N, or nSP70-C, and any cytotoxic effects were monitored by analyzing DNA synthesis. The results of this study show that nSP70-N and nSP70-C have a smaller effect on DNA synthesis activity by comparison to unmodified nSP70. Analysis of the intracellular localization of the silica nanoparticles revealed that nSP70 had penetrated into the nucleus, whereas nSP70-N and nSP70-C showed no nuclear localization. These results suggest that intracellular localization is a critical factor underlying the cytotoxicity of these silica nanoparticles. Thus, the surface properties of silica nanoparticles play an important role in determining their safety. Our results suggest that optimization of the surface characteristics of silica nanoparticles will contribute to the development of safer forms of NMs.     

Instrument for ceramic particle dispersion II: Computational fluid dynamics analysis

A planetary-type mixer using a container equipped with stainless steel mesh has been developed. For various slurries (Al₂O₃ in water), each modeled as Newtonian fluid, the shear stress was calculated using computational fluid dynamics (CFD) under various mixing conditions and with different equipment properties. The meshed-geometry included more than 100,000 nodes with hexahedral cells in one zone, with quadrilateral cells in the remaining zones. The fluid viscosity, rotation rate, and mesh opening affected the maximum shear stress. The shear stress increased concomitantly with increasing fluid viscosity. The container rotation rate and the maximum shear stress share a proportional relation. For a fluid with 9.2 mPa s, the shear stress was 134 Pa or more for a 0.81 mm and larger mesh opening, as observed at the bottom of the container. Mesh having an opening smaller than 0.81 mm generated high shear stress on the mesh surface. The maximum shear stress increased with decreasing mesh opening size. The particle size distributions of the Al₂O₃ particles in the slurries after treatment by the mixer were estimated under conditions similar to those of the calculations. Results show peaks in the particle size distributions of the Al₂O₃ particles in the slurries before treatment at 0.2 and 2-70 μm because of the primary particle size and agglomerates. The amounts of the agglomerate decreased concomitantly with the decreased mesh opening size. When slurries pass through the small mesh openings, high shear stress is generated. That achieves the good dispersion of the sub-micron sized Al₂O₃ particles in the slurry.     

Identification and characterisation of a calcium carbonate-binding protein, blue mussel shell protein (BMSP), from the nacreous layer

The nacreous layer of molluscan shells consists of a highly organised, layered structure comprising calcium carbonate aragonite crystals, each surrounded by an organic matrix. In the Japanese pearl oyster Pinctada fucata, the Pif protein from the nacreous layer functions in aragonite binding, and plays a key role in nacre formation. Here, we investigated whether the blue mussel Mytilus galloprovincialis also has a protein with similar functions in the nacreous layer. By using a calcium carbonate-binding assay, we identified the novel protein blue mussel shell protein (BMSP) 100 that can bind calcium carbonate crystals of both aragonite and calcite. When the entire sequence of a cDNA encoding BMSP 100 was determined, it was found that BMSP is a preproprotein consisting of a signal peptide and two proteins, BMSP 120 and BMSP 100. BMSP 120 contains four von Willebrand factor A (VWA) domains and one chitin-binding domain, thus suggesting that it has a role in maintaining structure within the matrix. Immunohistochemical analysis revealed that BMSP 100 is present throughout the nacreous layer with dense localisation in the myostracum. Posttranslational modification analysis indicated that BMSP 100 is phosphorylated and glycosylated. These results suggest that there is a common molecular mechanism between P. fucata and M. galloprovincialis that underlies the nacreous layer formation.