A comparison of low temperature neutron and X-ray structures of K2Pt(CN)4Br0.3·3H2O,KCP (Br)

We compare the structure of KCP determined at 77°K by neutron methods with that recently determined at 90°K by x-rays. Both methods find two Pt-Pt distances which are equal within normal error limits. The neutron study shows however that the Pt thermal motion is slightly anisotropic with preferred motion perpendicular to $\text{c}$; this is contrary to the x-ray result which finds a strongly anisotropic thermal vibration parallel to $\text{c}$. No evidence is found in the neutron study for the occupation by water of a second disordered site located at $\text{～}\text{c}\text{6}$ from the normal Br^? site at $\text{1}\text{2}$$\text{1}\text{2}$$\text{1}\text{2}$.     

Importance of residues carboxyl terminal relative to the cleavage site in substrates of mitochondrial processing peptidase for their specific recognition and cleavage

We previously identified distal and proximal arginine residues in the N-terminal portion and an aromatic amino acid at position 1 (P1' site3) relative to the cleavage site as important recognition signals in substrates of mitochondrial processing peptidase [Niidome, T., Kitada, S., Shimokata, K., Ogishima, T., and Ito, A. (1994) J. Biol. Chem. 269, 24714-24722; Ogishima, T., Niidome, T., Shimokata, K., Kitada, S., and Ito, A. (1995) ibid. 270, 30322-30326]. To further elucidate the elements required for the specific recognition and cleavage by the enzyme, we synthesized synthetic peptides that possessed only the distal and proximal arginine residues and phenylalanine at the P1' site in a poly alanine sequence, and analyzed the processing reaction toward them. They were not cleaved by the peptidase although they inhibited the peptidase activity. However, when serine was introduced into the C-terminal portions of the sequence, processing was observed. The efficiency of the resultant peptides improved as the number of serine residues was increased. A peptide with serine or histidine at P2' and threonine at P3' was processed most efficiently. These results indicate that the processing reaction catalyzed by the peptidase depends not only on the N-terminal portion but also on the C-terminal portion from the cleavage site in the substrates.     

Iridium‐Catalyzed Annulation of Aromatic Imines with 1,3‐Dienes via Direct Functionalization of an Aromatic C?H Bond

The [3+2] annulation of N‐sulfonyl aromatic imines with 1,3‐dienes proceeded via a direct C H functionalization to give 1‐aminoindane derivatives in high yields with high regio‐ and stereoselectivities. The iridium complex coordinated with a substrate 1,3‐diene displayed high catalytic activity. The reaction proceeds via the direct formation of the aryliridium(I) species from the aromatic aldimine and an iridium(I) acetate species via a concerted metalation‐deprotonation pathway.

     

Carbon Interlayer Between CVD SiC and SiO2 in High‐Temperature Passive Oxidation

The oxidation behavior of high‐purity silicon carbide (SiC) prepared by chemical vapor deposition was investigated by thermogravimetry, transmission electron microscopy, and Raman spectroscopy in the temperature range 1534–1902 K in pure O₂. The carbon layer formed at the SiC/SiO₂ interface upon oxidation above 1784 K. Raman peaks corresponding to D‐ and G‐bands could be identified from the carbon layer. Bubbles were observed in the SiO₂ scale after the oxidation at 1873 K. This could be attributed to the accumulation of CO gas at the SiC/SiO₂ interface, resulting in the formation of the carbon layer and bubbles. These suggest that the oxidation rate of SiC is limited by the outward diffusion of CO in the SiO₂ scale in this temperature range.     

Daily Ingestion of Aloe Vera Gel Powder Containing Aloe Sterols Prevents Skin Photoaging in OVX Hairless Mice

Estrogen deficiencies associated with menopause accelerate spontaneous skin aging and stimulate the ultraviolet (UV) irradiation‐induced photoaging of skin. However, food compositions with the potential to ameliorate the UV irradiation‐induced acceleration of skin aging with menopause have not yet been investigated in detail. In the present study, we examined the ability of plant sterols derived from Aloe vera gel to prevent the UV irradiation‐induced acceleration of skin aging in ovariectomized mice. Skin transepidermal water loss (TEWL) was significantly higher in the ovariectomy group than in the sham operation group following UVB irradiation, whereas skin elasticity was significantly lower. Ultraviolet B (UVB) irradiation induced greater reductions in skin hyaluronic acid levels and more severe collagen fiber damage in the derims in the ovariectomy group than in the sham group. The intake of AVGP significantly ameliorated this acceleration in skin aging by reducing the expression of matrix metalloproteinases (MMPs) and increasing that of epidermal growth factor (EGF) and hyaluronan synthase (HAS) in the skin. These results indicate that AVGP supplementation prevents skin damage induced by UVB irradiation and ovariectomy in part by inhibiting damage to the extracellular matrix.     

Bonding Properties of Liquid Crystalline Epoxy Resins Having Different Phase Structures

Liquid-crystalline epoxy resin systems, which have different phase structures (isotropic and nematic polydomain), were prepared. The bonding properties of their systems were investigated and related to their phase structure. As a result, the lap shear strength of the nematic system was lower than that of the isotropic system, although the nematic adhesive layer showed larger deformability than the isotropic one. The interfacial bonding properties of both the isotropic and nematic systems were investigated, and, thus, it was clarified that the low bonding strength of the nematic system was due to the low concentration of hydroxyl groups at the adhesive interface. The decrease in the concentration of hydroxyl groups was due to the restriction of the molecular motion derived from the ordered structure of the nematic system.     

Material performance in a solvent extraction Liquefaction plant in Japan

Corrosion behaviour of various steels and alloys in the solvent extraction coal liquefaction process in Japan has been studied by the inplant testing in a 1 ton/ day plant and by the laboratory tests related to it. The severest corrosion was observed in the high pressure separator, corrosion thickness loss and pitting depth being the greatest and stress corrosion cracking being observed for 18–8 series austenitic stainless steels. The cause may be the occurrence of water condensate containing high Cl^? and H₂S. Otherwise corrosion was relatively mild. No obvious symptom of notorious organic-chloride corrosion reported in the U.S. has been observed.     

Effect of amorphous silica nanoparticles on in vitro RANKL-induced osteoclast differentiation in murine macrophages

Amorphous silica nanoparticles (nSP) have been used as a polishing agent and/or as a remineralization promoter for teeth in the oral care field. The present study investigates the effects of nSP on osteoclast differentiation and the relationship between particle size and these effects. Our results revealed that nSP exerted higher cytotoxicity in macrophage cells compared with submicron-sized silica particles. However, tartrate-resistant acid phosphatase (TRAP) activity and the number of osteoclast cells (TRAP-positive multinucleated cells) were not changed by nSP treatment in the presence of receptor activator of nuclear factor κB ligand (RANKL) at doses that did not induce cytotoxicity by silica particles. These results indicated that nSP did not cause differentiation of osteoclasts. Collectively, the results suggested that nanosilica exerts no effect on RANKL-induced osteoclast differentiation of RAW264.7 cells, although a detailed mechanistic examination of the nSP70-mediated cytotoxic effect is needed.     

Bonding Properties of Liquid Crystalline Epoxy Resins Having Different Phase Structures

Liquid-crystalline epoxy resin systems, which have different phase structures (isotropic and nematic polydomain), were prepared. The bonding properties of their systems were investigated and related to their phase structure. As a result, the lap shear strength of the nematic system was lower than that of the isotropic system, although the nematic adhesive layer showed larger deformability than the isotropic one. The interfacial bonding properties of both the isotropic and nematic systems were investigated, and, thus, it was clarified that the low bonding strength of the nematic system was due to the low concentration of hydroxyl groups at the adhesive interface. The decrease in the concentration of hydroxyl groups was due to the restriction of the molecular motion derived from the ordered structure of the nematic system.     

Development of the automated gold-linked electrochemical immunoassay system for blood monitoring

This paper reports the development of fully automated miniaturized immunoassay system. The system consist of postage stamp sized microchip and compact (post card sized foot print) microchip driver. To realize easy sample loading into the microchip, surface modification of polydimethylsiloxane (PDMS) was developed, and life time of the modified surface up to 9 days is confirmed. The microchip just consumes a droplet of blood (2 μl) and the loading and metering of the sample is realized by capillary action, therefore the microchip is compatible with blood collection method by using lancet needle. Fully automated immunoassay protocol in the system is demonstrated within 15 min using whole blood sample. Finally, fully automated detection of antigen (insulin) was successfully demonstrated in the developed system.