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Notes: Summary A cytochemical study of gastric K+-stimulated p-nitrophenylphosphatase (K-NPPase) activity, corresponding to a K+-stimulated phosphoprotein phosphatase of H-K-ATPase system, has been made by a new cytochemical method. Sections of fixed guinea pig gastric mucosa in a mixture of 2% paraformaldehyde and 0.25% glutaraldehyde, were incubated with the incubation medium (1.0 M glycine-0.1 M KOH buffer, pH 9.0, 2.5 ml; 1.1 M KCl, 0.5 ml; 10 mM lead citrate dissolved in 50 mM KOH, 4 ml; levamisole, 6.0 mg; dimethyl sulfoxide, 2.0 ml; 0.1 M p-nitrophenylphosphate (Mg-salt), 1.0 ml; ouabain, 73.0 mg) for 30 min at room temperature. Under a light microscope the specific gastric K-NPPase reaction was distributed only in the parietal cells of the fundic glands. The electron microscopic cytochemistry showed that the gastric K-NPPase activity was localized on the membrane lining the apical surfaces, secretory canaliculi and tubulovesicles. On the other hand, ouabain-sensitive K-NPPase activity (Na-K-ATPase) was demonstrated to localize only in the basolateral membrane of parietal cells with Mayahara's method. These findings support the interrelationships between the apical surface membrane, secretory canalicular membrane and tubulovesicles, and the functional differentiation of the membrane between the secretory membrane and basolateral membrane.

Notes: Previous studies have shown that nanoparticle chain aggregates (NCA) of titania are elastic [S. K. Friedlander, H. D. Jang and K. H. Ryu, Appl. Phys. Lett. 72, 1 (1998)]. The NCA were a few tenths of a micron long and composed of (approximately) 7 nm primary particles. They were produced by thermal decomposition of titanium tetraisopropoxide vapor in nitrogen. The goal of this study was to see whether the elastic behavior depends on (a) the material properties, (b) primary particle size, and (c) method of NCA formation. For this purpose, titania, alumina, and iron oxide NCA were generated by laser ablation. Rotating metal foil targets were mounted in a small cylindrical chamber and exposed to an excimer laser beam. The resulting aerosol was swept out by an oxygen stream. The generator was operated to produce NCA with similar mobility diameter and primary particle size. The NCA were deposited on the carbon or formvar films of an electron micrograph grid. Under the electron beam a hole develops in the carbon film in the neighborhood of the deposited NCA. The NCA then stretch and contract as described in our earlier study [S. K. Friedlander, H. D. Jang and K. H. Ryu, Appl. Phys. Lett. 72, 1 (1998)]. The titania, alumina, and iron oxide NCA generated by laser ablation all showed elastic behavior for primary particles smaller than about 10 nm. However, titania NCA composed of 36 nm primary particles did not exhibit elastic behavior indicating that very small primary nanoparticles are needed for this phenomenon to occur. The small scale stretching and contraction of chain segments were studied by measuring changes in the bond angles between adjoining particles and in the lengths of the segments studied. The elastic behavior is probably associated with local folding of chain segments due to van der Waals forces. Under tension, folded chains straighten but when the tension is relaxed, folds tend to reform but not reversibly. Rotation and sliding probably occur at the boundaries between particles during stretching. We hypothesize that elastic behavior is a general property of NCA composed of transition metal oxides with primary particles smaller than 10–15 nm; the phenomenon has now been observed for NCA produced in two ways, thermal decomposition and laser ablation. These phenomena may play a role in the action of nanoparticle additives such as fumed silica and carbon black used to improve the properties of rubber. NCA elasticity may also contribute to the ductile properties of nanoparticle compacts. © 2000 American Institute of Physics.

Notes: We report the first experimental observation of excitonic polaritons in a GaAs/AlGaAs quantum well with incident light propagating parallel to the quantum well layer. We have built a time-of-flight measurement system which allows us to investigate low-temperature optical properties of semiconductor waveguides with picosecond time resolution. This system has been used to measure propagation delay time of an incident light pulse transmitted through the quantum well. The delay time increases drastically near the photon energies resonant to the optical absorption lines of the quantum well excitons. This behavior shows that the group velocity of the light pulse decreases as a result of the formation of quantum well excitonic polaritons. The group velocity drops to 7×104 m/s at a heavy-hole exciton absorption line at 6.0 K.

Notes: Single-crystal layers of ZnSe have been grown on GaP and GaAs substrates in a hydrogen transport system. By the use of the H2 bypass flow, the growth rate versus substrate temperature characteristics are found to be modified. The growth on GaP (111)B substrates is limited by thermodynamic mass transport and that on GaP (100) substrates by the kinetics of the surface chemical reaction. ZnSe layers grown on the GaAs (100) face have larger growth rates and smoother surface morphologies than those on GaP (100). This result may originate from the lattice parameter mismatch between the epitaxial layers and the substrates.

Notes: Blood flow stagnation is said to be an important factor for the incidence of dark eye circles, but there are few reports, which have studied dark eye circles and the relationship to blood flow. We have examined dark eye circles dermatologically using a non-invasive method and made clear the factor related to it. We have also studied the effect of newly developed cosmetics on improvement of dark eye circles. Melanin and haemoglobin content, haemoglobin oxygen saturation and blood flow rate were measured to compare dark eye circles with a normal control. An increased amount of haemoglobin and decreased haemoglobin oxygen saturation were observed at the site of dark eye circles. We also observed that the blood flow rate was slow at dark eye circles in comparison with cheek. From these results, blood flow stagnation seems to be one of the factors that could induce dark eye circles. In addition, the increase of melanin at dark eye circles was also observed in older subjects. It was considered that not only congestion but also an increase of melanin content in the skin could induce dark eye circles. On the basis of these results, we developed anti-dark eye circle cosmetics that can improve blood circulation, reduce melanin content and maintain high moisture retention in the skin. After 3 weeks’ usage of this product, it was confirmed that dark eye circles were improved, judging from the result of non-invasive instrumental measurements.

Notes: Background We have recently demonstrated that the transfer of interleukin (IL)-5-producing CD4+ T cell clones into unprimed mice is sufficient for the development of eosinophilic inflammation in the bronchial mucosa upon antigen inhalation.Objective The aim of this study was to elucidate the possible contribution of mast cells in eosinophilic inflammation and bronchial hyper-responsiveness (BHR), and to discriminate between the roles of CD4+ T cells and mast cells.Methods Mast cell-deficient mice (WBB6F1-W/Wv) and their congenic normal littermates (WBB6F1−+/+) were immunized with ovalbumin and challenged by inhalation with the relevant antigen.Results Airway eosinophilia was induced with equivalent intensity in +/+ and W/Wv mice 6, 24, 96 and 216 h after antigen inhalation. In contrast, 48 h after antigen challenge, eosinophilic infiltration into the bronchial mucosa was significantly less pronounced in W/Wv mice than in +/+ mice. Anti-CD4 monoclonal antibody (mAb), anti-IL-5 mAb, and cyclosporin A were administered next, demonstrating that the airway eosinophilia of W/Wv mice induced 48 h after antigen challenge was almost completely inhibited by each of these three treatments, but that of +/+ mice was significantly less susceptible. Bronchial responsiveness to acetylcholine was increased 48 h after antigen challenge and was not significantly different between +/+ and W/Wv mice. Administration of anti-IL-5 mAb completely inhibited the development of BHR in both +/+ and W/Wv mice.Conclusion These results indicate that, in mice, mast cells do have a supplemental role in the development of pulmonary eosinophilia but not BHR. CD4+ T cells totally regulate these responses by producing IL-5.