Stimulation of In Vivo Antitumor Immunity with Hollow Mesoporous Silica Nanospheres

The use of appropriate adjuvants that support the generation of robust and long‐lasting antitumor immune responses is crucial for tumor immunotherapy owing to the immunosuppressive environment of the growing tumor. However, the most commonly used adjuvant, aluminum hydroxide, is ineffective for generating such immune responses and therefore not suitable for cancer immunotherapy. It is now shown that plain hollow mesoporous silica nanospheres markedly improve the antitumor immunity, the Th1 and Th2 immunity, and the CD4⁺ and CD8⁺ effector memory T cell population in bone marrow in vivo and may thus be used as immunoadjuvants to treat cancer in humans.     

Numerical study of tip opening of hydrogen/air Bunsen flame

To understand tip opening of a hydrogen–air Bunsen flame, the detailed flow, temperature and concentration fields of the flame were studied based on numerical calculations that use the exact transport properties and the full chemical reaction mechanism. The study has revealed that the local chemical reactions along the flame cone portion do not remain uniform; the H₂ consumption rate decreases in the downstream direction. The lowering H₂ concentration of the mixture coming into the cone, caused by the radial outward diffusion of mobile H₂ molecules, leads to the slowdown of the main H₂-consuming reactions downstream and causes the breakdown of the reaction at the downstream end of the cone. This is the tip opening.     

Coprecipitation Behavior of Some Metals with Chitosan and Their Determination by Graphite Furnace Atomic Absorption Spectrometry

Chitosan is derived from chitin by deacetylation. Chitosan forms a complex with metal ions and is soluble an organic acid. The metal ions were concentrated in the precipitates of chitosan when the sample solution containing metal ions was adjusted to neutral after the chitosan solution was added. These properties are applied to the preconcentration of metal ions in water samples and their determination by graphite furnace atomic absorption spectrometry. Metal ions,such as ruthenium, indium, vanadium, strontium,rhodium were collected in the chitosan precipitates.     

New trend of radiation application to polymer modification — irradiation in oxygen free atmosphere and at elevated temperature

Polycarbosilane (PCS) fiber as a precursor for ceramic fiber of silicon carbide was cured by electron beam (EB) irradiation under oxygen free atmosphere. Oxygen content in the cured PCS fiber was scarce and the obtained silicon carbide (SiC) fiber with low oxygen content showed high heat resistance up to 1973 K and tensile strength of 3 GPa. Also, the EB cured PCS fiber with very low oxygen content could be converted to silicon nitride (Si₃N₄) fiber by the pyrolysis in NH₃ gas atmosphere, which was the new processing to produce Si₃N₄ fiber. The process of SiC fiber synthesis was developed to the commercial plant.

The other application was the crosslinking of polytetrafluoroethylene (PTFE). PTFE, which had been recognized to be a typical chain scission polymer, could be induced to crosslinking by irradiation at the molten state in oxygen free atmosphere. The physical properties such as crystallinity, mechanical properties, etc. changed much by crosslinking, and the radiation resistance was much improved.     

ESR study on chemical crosslinking reaction mechanisms of polyethylene using a chemical agent—II. The effect of phenolic antioxidants

The effect of antioxidant on the reaction mechanism of chemical crosslinking of polyethylene (PE) with dicumyl peroxide (DCP) at high temperatures was investigated by electron spin resonance (ESR). The antioxidant reacts with the alkyl radicals in PE formed by the thermal decomposition of DCP above 120°C, and disturbs the crosslinking. A phenolic type antioxidant produced the phenoxy radical by the reaction with alkyl radicals formed in PE. It is suggested that the selection of a suitable antioxidant for PE crosslinking can be made by ESR analysis. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2431–2439, 1997     

Conformation and dynamics of polymer chains in condensed systems

A Stockmayer's type-A chain such as cis-polyisoprene (PI) having dipole components parallel to the chain contour exhibits slow dielectric response, reflecting fluctuation of its end-to-end vector ( dielectric normal modes ). This article reviews our own work on dielectric spectroscopy for studying dynamics and conformational properties of probe PI chains in binary blends with PI or polybutadiene (PB) that does not exhibit normal modes. Through such studies we were able to see the crossover of the probe-chain dynamics from Rouse behaviour in low-molecular-weight (lmw) matrices to pure reptation behaviour in high-molecular-weight (hmw) matrices. We were also able to confirm experimentally Flory's earlier prediction on excluded volumes in dilute blends of hmw probe chains in lmw matrices, for which a proof has never been given before.     

Rheology of heterophase polymer systems

This lecture attempts to elucidate rheological behavior of multiphase polymer systems through a comparison with our studies on much simpler systems such as suspensions of (a) non-aggregating and (b) aggregating monodisperse spheres in viscoelastic media, (c) polymer latex in the same polymer liquids, and (d) emulsions or blends of two polymers with or without an emulsifying block copolymer. For the system (a) not only the viscosity η but also the modulus obey the known simple dependence on volume fraction ϕ of hard-sphere suspensions, while for the system (b) the flow induced-aggregation and dissociation of the particles govern the rheology. In the system (c), relaxations of entanglements of the adsorbed chains as well as the spatial distribution of the latexes are essential. For the emulsion (d) of a biased composition range (e.g., ϕ₁ > ϕ₂) the matrix phase 1 dominates, unless η₁ << η₂. When η₁ ≥ η₂, deformation and/or bursting of the dispersed phase 2 take place. For those of an even composition, the viscosity is additive of those of the components and is enhanced by adding the emulsifying block copolymer component.     

A Quantum Algorithm for a FULL Adder Operation Based on Registers of the CPU in a Quantum-gated Computer

International Journal of Theoretical Physics - So far, the world of quantum-gated computing has been exploited, aimed at the limited applications based upon the Deutsch algorithm in 1985 and a few...     

Insight into chemical mechanisms of sepal color development and variation in hydrangea

Hydrangea (Hydrangea macrophylla) is a unique flower because it is composed of sepals rather than true petals that have the ability to change color. In the early 20th century, it was known that soil acidity and Al³⁺ content could intensify the blue hue of the sepals. In the mid-20th century, the anthocyanin component 3-O-glucosyldelphinidin (1) and the copigment components 5-O-caffeoylquinic, 5-O-p-coumaroylquinic, and 3-O-caffeoylquinic acids (2–4) were reported. Interestingly, all hydrangea colors from red to purple to blue are produced by the same organic components. We were interested in this phenomenon and the chemical mechanisms underlying hydrangea color variation. In this review, we summarize our recent studies on the chemical mechanisms underlying hydrangea sepal color development, including the structure of the blue complex, transporters involved in accumulation of aluminum ion (Al³⁺), and distribution of the blue complex and aluminum ions in living sepal tissue.     

Using Inequalities as Tests for the Kochen-Specker Theorem for Multiparticle States

The Kochen-Specker theorem is investigated for n spin-1/2 systems by using an inequality proposed in Nagata (J. Math. Phys. 46, 102101, 2005) on the basis on binary logic. A measurement theory based on the truth values (binary logic), i.e., the truth T (1) for true and the falsity F (0) for false is used. The values of measurement outcome are either + 1 or 0 (in \(\hbar /2\) unit). The quantum predictions by n-multipartite states violate the inequality by an amount that grows exponentially with n. The measurement theory based on the binary logic provides an exponentially stronger refutation of the existence of hidden-variable when the number of parties of the state increases more. It turns out that the Kochen-Specker theorem becomes a quite strong theorem when the dimension of the multipartite state highly increases, regardless of entanglement properties.