Auto-oxidation products of astaxanthin

The auto-oxidation products of astaxanthin were investigated. Astaxanthin was allowed to react with atmospheric oxygen at 55°C in the dark for 35 days. A series of oxidative cleavage products, 7-apoastaxanthinal (1), 9-apoastaxanthinone (2), 11-apoastaxanthinal (3), 13-apoastaxanthinone (4), 15-apoastaxanthinal (5), 14'-apoastaxanthinal (6), 12'-apoastaxanthinal (7), 10'-apoastaxanthinal (8), and 8'-apoastaxanthinal (9), were identified. Among them, 3 and 6 were isolated and characterized for the first time. Cleavage of the double bond in astaxanthin was discussed on the basis of the calculation of the stable molecular energy.     

Materials science of carbon nanotubes: fabrication,integration, and properties of macroscopic structures of carbon nanotubes

In this Account, we summarize some of our recent studies on the materials properties of the carbon nanotubes (CNTs). The focus is on single-wall carbon nanotubes (SWNTs). We describe experiments on synthesis of SWNTs with controlled molecular structures and assembly of functional macroscopic structures. In addition, we present results on the electron field emission properties of macroscopic CNT cathodes.     

An experimental and theoretical investigation of rarefied gas flow through circular tube of finite length

The conductance of nitrogen gas through circular tube of finite length was measured in the continuum and transition regimes for length to diameter ratios L/D ranging from 0.045 to 33.4 and pressure ratios across the tubes P₁/P₂ from 1.1 to 23. A numerical analysis was carried out to estimate the conductance using the continuum approach in the continuum regime and transition regime at low Knudsen number, and using direct simulation Monte Carlo (DSMC) method in the transition regime at high Knudsen number. The observed conductances were compared with the simulation and an empirical equation derived by Hanks-Weissberg. Both the experimental and simulation results show that the conductances at a constant gas flow rate increases linearly with increasing arithmetic mean pressure across the tube P_av=(P₁+P₂)/2, irrespective of the P₁/P₂ ratio. The observed conductances were smaller than those predicted by the Hanks-Weissberg's equation. The deviation increases with increasing gas flow rate, and with decreasing L/D ratio. It was confirmed that the deviation occurs due to the increase in the effects of inertia and expansion in the flowing gas with increasing flow rate and decreasing L/D. A semi-empirical equation was derived by substituting the Poiseuille term in the Bernoulli formula with Hank-Weissberg's equation under the condition of isothermal expansion. The proposed equation was found to be valid in the range of the continuum regime to the transition regime at low Knudsen number.     

Synthesis and properties of novel fluoroalkyl end‐capped oligomers containing silsesquioxane segments

Fluoroalkyl end‐capped homo‐ and co‐ oligomers containing silsesquioxane segments were prepared by the reactions of fluoroalkanoyl peroxides with the corresponding methacrylate monomer‐bearing silsesquioxane unit (Si‐MMA) and comonomers such as N,N‐dimethylacrylamide (DMAA) and acrylic acid (ACA). These new fluorinated Si‐MMA oligomers were easily soluble in various organic solvents and were able to reduce the surface tension of m‐xylene effectively. The modified poly(methyl methacrylate) [PMMA] and glass surface treated with fluorinated Si‐MMA homo‐oligomers exhibited a strong oleophobicity, although these fluorinated oligomers possess high oleophilic silsesquioxane segments. In contrast, the modified PMMA surface treated with fluorinated Si‐MMA–DMAA cooligomers exhibited a good hydrophilicity with a strong oleophobicity. In a series of fluorinated Si‐MMA oligomers, fluorinated Si‐MMA homo‐oligomers had a relatively high thermal stability. Therefore, these fluoroalkyl end‐capped Si‐MMA oligomers are suggested to have high potential for new functional materials through their unique properties such as a high solubility and surface active properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3486–3493, 2002     

Immunomodulation by TYB-2285 of Dermatophagoides farinae (Df) antigen-induced IFN-gamma and IL-4 production in lymphocytes from children with bronchial asthma

Effect of TYB-2285 and its metabolites on immune responses by peripheral blood mononuclear cells (PBMC) from children with bronchial asthma was investigated. TYB-2285 and its metabolites have immunosuppressive activity for the proliferation by Df-stimulated patients' lymphocytes. Concanavalin A (Con A)-activated peripheral blood mononuclear cells (PBMC) from the patients were not affected by the same treatment. The results indicate that TYB-2285 and its metabolites are capable of suppressing antigen-induced 3H-thymidine (3H-TdR) uptake but not the response induced by Con A. Interferon-gamma (IFN-gamma) production by Df-stimulated PBMC from patients with active asthma, which was lower than that of normal lymphocytes, were reversed beyond the levels of that in normal subjects. Thus reduced production of IFN-gamma by Df-stimulated patients' lymphocytes was increased by TYB-2285 and its metabolites in a dose-dependent manner. This phenomenon was not observed in lymphocytes from normal subjects. Furthermore, TYB-2285 inhibited IL-4 production induced by Df antigen in asthmatic patients' lymphocytes. Taken, together, TYB-2285 could work as a weak immunosuppressant to modify lymphocytes' responses to allergen in patients with bronchial asthma. These data underscore the potential benefit for the patients with bronchial asthma.     

Prevalence and risk factors of allergic rhinitis and cedar pollinosis among Japanese men

Sequences of the 5.8S rDNA were obtained for 14 species of nematode from different superfamilies and families within the order Ascaridida. All sequences were 157 bp in length. Sequence differences among species ranged from 0 to 18 bp (0-11.5%). A phenetic analysis of the sequence data groups the 14 taxa into their respective superfamilies and families, but does not discriminate fully at the subfamily level. A phylogenetic analysis of the sequence data failed to resolve the evolutionary relationships at the superfamily level. The 5.8S gene may be useful for phylogenetic studies of the phylum Nematoda at the ordinal level.     

Human cortico-hippocampal activity related to auditory discrimination revealed by neuromagnetic field

We carried out multi-dipole estimation and pursued spatio-temporal brain activity on a time scale of several milliseconds during an auditory discrimination task using a whole-cortex type SQUID system. Neuronal activities were estimated in the medial (hippocampus, parahippocampal gyrus, etc.) and lateral temporal cortices (superior and middle temporal gyri, etc.), the dorsolateral prefrontal cortex (middle and inferior frontal gyri, etc.) and the parietal cortex (supramarginal gyrus, etc.) in the 280-400 ms latency range. The activity in the posterior hippocampal region was the most prominent and long-lasting in parallel with the activities in the other regions. Therefore, the posterior hippocampal region is a central structure engaged in auditory discrimination. The whole-cortex neuromagnetic measurements provided the possibility of imaging the time-varying activities of the human cortico-hippocampal neural networks.     

Design and testing of a new cisplatin form using a base material by combining poly-D,L-lactic acid and polyethylene glycol acid against peritoneal metastasis

Microspheres containing cisplatin (CDDP) embedded in poly-d,l-lactic acid (PLA) and polyethylene glycol acid (CDDP-PPMS) were developed to improve treatment of malignant effusions. In vitro studies demonstrated that CDDP was released continuously for more than 4 weeks from CDDP-PPMS without initial burst. CDDP-PPMS was compared with CDDP aqueous solution (CDDP-SOL) by i.p. administration in rats for 1) tissue distribution, 2) toxicity and 3) therapeutic effects against Yoshida sarcoma. We found that the CDDP concentration in the omentum was maintained at a higher level than in the CDDP-SOL group, while the particles of CDDP-PPMS were observed in the stomata of the omentum by electron microscopy. Concentrations of CDDP in the lung, liver, kidney and blood were lower in the CDDP-PPMS group than in the CDDP-SOL group. All rats given CDDP-PPMS containing < or = 28 mg/kg were alive, whereas in the CDDP-SOL group, all rats given > or = 16 mg/kg died from side effects. The LD50 of CDDP-PPMS and CDDP-SOL were 32.8 and 14.8 mg/kg, respectively. The survival of rats with peritoneal metastasis was better in the CDDP-PPMS group than in the CDDP-SOL group.     

Ketosis-onset diabetes in young adults with subsequent non-insulin-dependency, a link between IDDM and NIDDM?

Reactivation of infections with herpes viruses is a frequent and major cause of morbidity after bone marrow transplantation. In this case report we stress that HSV infections of the colon and small intestine should be considered in the differential diagnosis of diarrhea and intestinal bleeding in the early post-transplantation period. Severe acute GVHD and subsequent intensive immunosuppressive treatment may increase the risk for reactivation of HSV infection particularly in situations in which acyclovir prophylaxis has been omitted.     

Sensitivity improvement of automatic pulmonary nodules detection in chest X-ray CT images

In this article, we develop an automatic detection method for non-isolated pulmonary nodules as part of a computer-aided diagnosis (CAD) system for lung cancers in chest X-ray computed tomography (CT) images. An essential core of the method is to separate non-isolated nodules from connecting structures such as the chest wall and blood vessels. The isolated nodules can be detected more easily by the CAD systems developed previously. To this end, we propose a preprocessing technique for nodule candidate detection by using double-threshold binarization. We evaluate the performance using the receiver operating characteristic (ROC) analysis in clinical chest CT images. The results suggest that the detection rate for non-isolated nodules by the proposed method is superior to that by the conventional preprocessing methods.