Hexaphyrin as a Potential Theranostic Dye for Photothermal Therapy and 19F Magnetic Resonance Imaging

Two features of meso‐Aryl‐substituted expanded porphyrins suggest suitability as theranostic agents. They have excellent absorption in near infrared (NIR) region, and they offer the possibility of introduction of multiple fluorine atoms at structurally equivalent positions. Here, hexaphyrin (hexa) was synthesized from 2,6‐bis(trifluoromethyl)‐4‐formyl benzoate and pyrrole and evaluated as a novel expanded porphyrin with the above features. Under NIR illumination hexa showed intense photothermal and weak photodynamic effects, which were most likely due to its low excited states, close to singlet oxygen. The sustained photothermal effect caused ablation of cancer cells more effectively than the photodynamic effect of indocyanine green (a clinical dye). In addition, hexa showed potential for use in the visualization of tumors by ¹⁹F magnetic resonance imaging (MRI), because of the multiple fluorine atoms. Our results strongly support the utility of expanded porphyrins as theranostic agents in both photothermal therapy and ¹⁹F MRI.     

New radical salts based on TEMPO-substituted 2,4,6-triphenylpyridinium and transition metal complexes

Series of radical salts derived from a 2,4,6-triphenylpyridinium (TPP) carrying TEMPO-substituent and transition metal complexes were prepared by the anion exchange of the TPP–TEMPO tetrafluoroborate with [n-Bu₄N][Ni(dmit)₂], [n-Bu₄N]₂[Pd(dmit)₂], [n-Bu₄N]₂[Pt(dmit)₂], [n-Bu₄N][Ni(mnt)₂], or [n-Bu₄N]₂[Ni(mnt)₂] to give crystals with different structural features. While weak antiferromagnetic interactions of the Curie–Weiss behavior of S = 1/2 spin are predominantly observed in the salts of Pd(dmit)₂, Pt(dmit)₂ and Ni(mnt)₂, the magnetic behavior of 1:1 Ni(dmit)₂ salt can be explained by the additional contribution from the spins on Ni(dmit)₂ anions (χ − χ_TEMPO), obeying the 2D Heisenberg model. A couple of the oxidized salts, [TPP][Ni(dmit)₂] as well as [TPP]₂[Pd(dmit)₂], exhibit semi-conducting properties with relatively high room temperature conductivities.     

Preventing Fatal Fractures in Carbon-Fiber–Glass-Fiber-Reinforced Plastic Composites by Monitoring Change in Electrical Resistance

A method which monitors the changes in electrical resistance in CFGFRP (carbon-fiber–glass-fiber-reinforced plastics) composites was found to be a promising technique for foreseeing fractures and preventing fatal ones. CFGFRP composites containing two types of carbon fibers along with 31.6 vol% glass fibers were used. U-shaped copper electrodes were attached to both ends of the CFGFRP composites, using a conductive adhesive agent, and electrical resistance was measured via a two-thermal dc method. A strain gauge was attached onto a specimen to measure strain. On loading, the changes in electrical resistance increased linearly with increasing strain, and the value reached 38% for the CFGFRP composites containing 0.36 vol% PAN-based high-strength carbon fibers. A tremendous change in electrical resistance was seen for the CFGFRP composites containing 0.38 vol% pitch-based high-property carbon fibers, and the composites could maintain their shape owing to a hybrid effect after the carbon fibers fractured. The change in electrical resistance can be controlled through suitable selection of the type of carbon fibers according to their values of ultimate elongation. Permanent, residual electrical resistance was found to remain, and the changes in resistance were dependent on the maximum previous strain.     

Preparation, surface-active properties, and antimicrobial activities of bis(alkylammonium) dichlorides having a butenylen or a butynylene spacer

A series of new cationic gemini surfactants, bis(alkylammonium) dichlorides having a butenylene or a butynylene spacer, were prepared almost quantitatively by the reaction of a long-chain alkyldimethylamine with a highly reactive allylic or propargylic dichloride, and their surface-active properties were measured. All of them showed good water solubility and quite low critical micelle concentrations, which were more than one order of magnitude lower than those of the corresponding mono(alkylammonium) salts. They also showed quite high foaming ability and foam stability when they have an appropriate hydrophile-lipophile balance. Many of them showed almost the same antimicrobial activities against the eumycetes Aspergillus sp. and Candida albicans as commercial germicides such as benzalkonium chloride and chlorhexidine gluconate.     

Catalytic reduction system of NOx in exhaust gases from diesel engines with secondary fuel injection

Catalytic NO_x reduction system with secondary fuel injection was studied not only in a laboratory scale, but also in a large bench scale. Diesel fuel was injected before the catalyst bed, and the activity and durability of the catalyst for the NO_x reduction were tested. Using the fuel as a reductant, silver aluminate supported on alumina was selected as the most active and suitable catalyst. The resistance of the silver aluminate catalyst to SO_x was enhanced by the addition of a small amount of WO₃, MoO₃ and Pt. It was found from the engine bench test that NO_x conversion increased in proportion to the amount of aldehydes formed from the injected fuel in the exhaust gas. Thus, the secondary fuel injection into exhaust gas through a partial oxidation catalyst enhanced the NO_x conversion. At 450°C, the engine bench test exhibited maximum NO_x conversion of 75% and 45% at the SV of 15 000 and 70 000 h⁻¹, respectively.     

Optical fiber cables for residential and business premises

This paper describes a new drop cable, a new cluster-type drop cable for residential premises, a new indoor cable, a new termination cable and a new riser cable for fiber distribution in residential and business premises. The structural design of these cables is investigated and the optimum structures for cost reduction of cable and installation are obtained. Based on the results, these cables are manufactured and their transmission and mechanical characteristics are confirmed to be stable