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Porphyrin selectively shows tumour accumulation and has attracted attention as a carrier molecule for drug delivery systems (DDS). Porphyrin has two functional sites termed the meso- and β-positions. In previous work, meso-porphyrin derivatives with an alkyl group were found to exhibit greater accumulation in human breast cancer cells (MCF-7). To identify the correlation between porphyrin accumulation and functional porphyrin positions of other functional groups, the accumulation of porphyrin derivatives with a phenyl group was investigated. The β-porphyrin derivative with a phenyl group showed higher accumulation in MCF-7 cells and greater affinity for albumin than the meso-porphyrin derivative. The results of density functional theory (DFT) calculations suggest that the β-porphyrin derivative with a phenyl group had higher planarity across the total structure than the meso-porphyrin derivative. It was concluded that the greater planarity of the β-porphyrin derivative with a phenyl group might lead to superior MCF-7 cell accumulation.

Techniques for large-area pattern formation on polymeric substrates are important for fabricating a large variety of functional devices, such as flexible electronics, tunable optical devices, adhesives, and so on. The present study demonstrates a method for pattern formation on poly(dimethylsiloxane) that involves grafting methacrylate polymers through photo-initiated polymerization. The influence of substrate stiffness and monomers type on pattern formation was investigated. Firstly, the stiffness of the substrate was found to affect the topology of the patterns produced. The gap width of convex regions of the pattern was enlarged with decreasing stiffness. It was found that the gap width trended in a manner that was consistent with previous reports, but in this study, relatively large gap widths were observed compared with those from previous studies. Secondly, it was revealed that the solubility of the monomer in the poly(dimethylsiloxane) precursor was the dominant factor in determining whether or not pattern formation occurred. When using insoluble monomers (glycidyl methacrylate and benzyl methacrylate), characteristic patterns were observed. It is speculated that intermolecular attractive forces between the grafted polymers induce lateral aggregation on the substrate, resulting in buckling instability of the grafted polymer layer caused by a mismatch in the equilibrium between the grafted polymer layer and the substrate. Copyright © 2017 John Wiley & Sons, Ltd.

The surface of nanodiamond (ND) particles was modified with 1-octadecene via a simple thermal reaction to obtain octadecyl-modified ND. Fourier transform infrared spectroscopy and thermogravimetric analysis results indicated that octadecyl groups were successfully introduced onto the ND surface. The amount of the octadecyl groups on the ND surface was observed to increase with increasing reaction time and to eventually saturate. A bead-milling process, which enabled disaggregation of NDs in 1-octadecene, was observed to increase the amount of octadecyl groups adsorbed onto the ND surface. The estimated surface coverage was as high as 2.2 × 1014 molecules cm−2, which corresponds to submonolayer level. Dispersion tests revealed that the octadecyl-modified ND particles exhibit hydrophobic/lipophilic character, whereas the oxidized ND (before surface modification with 1-octadecene) exhibited good dispersibility in water. Particle size distribution analysis by dynamic light scattering revealed that the particle size of the octadecyl-modified ND in chloroform, a non-polar solvent, was ca. 20 nm. Thus, the present method should be useful for fabricating NDs that can be dispersed in non-polar organic solvents and should facilitate the expansion of the application fields of ND.

Primary challenges in electrochemical CO2 reduction lie with its product selectivity and competitive hydrogen evolution reaction (HER). Therefore, selective CO2 reduction with less hydrogen evolution or without any hydrogen evolution is very essential for industrial interests. In this study, we report a selective electrochemical CO2 reduction at a boron-doped diamond electrode modified with Cu nanoparticles in ionic liquid. In addition to the improved product selectivity, control of the competitive HER was also achieved in this work.

Petrological and geochemical characteristics of low- and high-temperature alterations were investigated in volcanic rocks from the northern Philippine Sea. The assemblage of secondary minerals is divided into two groups based on microprobe and XRD analyses. The first group, comprising samples from the Kyushu-Palau Ridge and Urdaneta Plateau, includes calcite, phillipsite, clay minerals and Fe-oxyhydroxides, reflecting low-temperature alteration. The content of secondary deposition is high in the Kyushu-Palau Ridge, but low in the Urdaneta Plateau. The second group, consisting of samples from the Amami Plateau, includes secondary alkali feldspar, analcime, and chlorite, reflecting high-temperature hydrothermal alteration. As groundmass alteration is dominant in the studied volcanic rocks, the alteration index, defined as the ratio of secondary minerals in voids to the total material count, is useful for estimating alteration degree when precise identification of secondary materials is difficult in highly vesicular rocks. Alteration indexes correlate with bulk H2O+ and loss on ignition (LOI) contents, and bulk major and trace element compositions of the studied volcanic rocks change with alteration. The difference of alteration types in three regions may depend on the tectonic setting of volcanism. That is: (i) the Kyushu-Palau Ridge is covered with the last lava flow of rifting volcanism associated with spreading of the Shikoku Basin, and the volcanics reacted with circulating seawater under low temperatures and oxidative conditions; (ii) the Urdaneta Plateau was formed as a result of intra-plate volcanism, and the volcanics were under seafloor weathering without seawater circulation associated with volcanic activity; and (iii) the Amami Plateau was produced by Cretaceous arc volcanism, which suffered high-temperature alteration associated with intrusive activity of tonalite.

Search for non-platinum metal catalyst as the cathode of polymer electrolyte membrane fuel cell (PEMFC) is an important subject in the recent fuel cell research. Macromolecule–metal complexes with macrocyclic ligands such as porphyrin and macromolecular ligands such as polypyrrole, all of which contain four nitrogen donors (Co-N4 chelates) and are adsorbed on carbon, were prepared and heat-treated in the hope that they can be an alternate to the conventional carbon-supported platinum catalyst. Carbon-supported cobalt (5,10,15,20-tetraethylporphyrin) (HT-CoTEtP/C), poly(cobalt (5-mono(3-thienyl)-10,15,20-triethylporphyrin)) (HT-P(CoM3ThTEtP)/C), and cobalt-(polypyrrole) (HT-CoPPy/C) were chosen as candidate heat-treated catalysts based on the electrocatalytic activity tests on the prepared macromolecule–metal complexes. The rotating ring-disk method revealed that these catalysts reduce oxygen mainly with four electrons. Characterization using X-ray photoelectron spectroscopy showed that the catalysts maintain the Co-N4 chelate structure, strongly suggesting a major contribution of the Co-N4 chelate to the four-electron reduction of oxygen. Membrane electrode assemblies (MEAs) of PEMFCs were then constructed using HT-CoTEtP/C, HT-P(CoM3ThTEtP/C), and HT-CoPPy/C as the cathode catalysts and the current density-cell voltage and current density-power density relationships were examined for the PEMFC. HT-CoTEtP/C exhibited a much higher performance than the other macromolecule–metal complexes. Although the open circuit voltage and power density values of the PEMFCs were lower than those of the conventional carbon supported platinum catalyst, the power density per unit metal weight was almost comparable for the cobalt and platinum catalysts. Copyright © 2011 John Wiley & Sons, Ltd.

In this article the novel design of an anticancer drug delivery system is reported based on a pH-sensitive liposome retaining the Fe-porphyrin as a superoxide dismutase(SOD) mimic. The liposomes contained cationic/anionic lipid combinations and were composed of Fe-porphyrin, L-α-phosphatidylcholine (DMPC), dimethylditetradecylammonium bromide (DTDAB), sodispdum oleate (OA Na ), and Tween-80. The size of the liposome was approximately 30 nm. The EC 50 value (the effective concentration of compound required to produce a 50% lethal dose against cells) of the liposome was found to be significantly smaller than that of cisplatin as the control drug, suggesting that the liposome showed a high cytotoxicity toward the cancer cells. This is due to the fact that the pH-sensitive liposome rapidly corresponds to the acidic environments of the endosomes and is unstable, and the Fe-porphyrin is delivered into the cytosol. This result suggests that O - 2 may be useful as a target molecule to induce the selective death of cancer cells and that a pH-sensitive liposome retaining Fe-porphyrin as an SOD mimic is a new class of anticancer agent.

5-(3-Thienyl)-10,15,20-triethyl-21H,23H-porphine (H 2 (ttep)) was synthesized and characterized. Oxidative polymerization of H 2 (ttep) gave a novel oligomeric porphyrin linked at the 2,5-positions of the thienyl group. Electric conductivity of 4 x 10 -1 S/cm after Ι 2 doping indicated that the oligomer had a π-conjugated structure with a delocalization of n electrons over the thienylene backbone. PM3 calculations revealed a low HOCO-LUCO gap, which was consistent with the relatively high electric conductivity. Regioregular (head-to-tail) structure was inferred from spectroscopic and calculational results. The pendant porphyrin groups formed a regular J-type array along the thienylene backbone, which was indicated by a significant red shift of the Soret band maximum.

meso-Substituted cobalt porphyrins adsorbed on carbon black were prepared as catalysts for the electroreduction of O2. The catalyst, which was prepared by using a homogenizer in mixing cobalt tetraethylporphyrin and carbon black, gave rise to electroreduction of O2 at a remarkably positive potential (Ep = 0.45 V versus saturated calomel electrode (SCE)) and showed a high selectively for the four-electron reduction (n = 3.8). Electrochemical study and extended X-ray absorption fine structure (EXAFS) analysis revealed that the adsorbed face-to-face dimeric aggregates of cobalt porphyrin molecules were highly efficient catalysts for electroreduction of O2. Copyright © 2005 John Wiley & Sons, Ltd.

Oxidative polymerization of bromoiron(III) meso-tetrakis(3-thienyl)porphyrin gave a novel polymeric porphyrin complex randomly crosslinked at the 2,5-positions of the peripheral thienyl groups. The electrical semiconductivity of ca. 10−5 S/cm after I2 doping indicated that the polymer had a π-conjugated structure with a moderate delocalization of π electrons over the thienylporphyrin units. PM3 calculations for free-base models revealed that HOCO (the highest occupied crystal orbital) band width was reduced by introduction of the porphyrin moieties into the thienylene backbone and yet low HOCO-LUCO (the lowest unoccupied crystal orbital) gap was maintained, which accounted for the relatively low electrical conductivity of the porphyrin polymer. The modified electrode prepared by electropolymerization was redox-active due to the presence of iron(II/III) couple and the semiconductivity of the film, which served as a novel non-enzymatic electrochemical sensor for superoxide anion radical based on the facile electrocatalytic oxidation of the superoxide. Copyright © 2005 John Wiley & Sons, Ltd.

A needle-type electrochemical sensor for the facile detection of superoxide anion radical (O - . 2 ) was devised using an electrodeposited film of a polymeric porphyrin complex attached to a carbon microelectrode which wasplaced in a stainless steel 18G needle tube as an auxiliary electrode. The sensing element was prepared by means of electropolymerization of bromoiron(III) mesotetra(3-thienyl)porphyrin in the presence of 1-methylimidazole in CH 2 Cl 2 containing 100 mM tetrabutylammonium perchlorate (TBAP) as a supporting electrolyte, which gave a smooth film of the corresponding polymer. The film was electrochemically active to give a redox response near -0.05 V versus Ag/AgCl due to the iron(II/III) couple. The microsensor was applied to detect O 2 produced by xanthine oxidation catalyzed by xanthine oxidase. The amperometric response for O 2 was monitored at an electrode potential of 0.5V versus the auxiliary electrode in a 10 mM phosphate buffer. The microsensor displayed a high catalytic activity for the oxidation of O - . 2 and showed a linear relationship between the current and the O - . 2 concentration. Axial coordination of an imidazole ligand to the iron porphyrin center enhanced selectivity for O - . 2 by impeding the undesired coordination of H 2 O 2 that resulted from the dismutation of O - . 2 .

A magnetic anomaly map of the northern part of the Philippine Sea plate shows two conspicuous north–south rows of long-wavelength anomalies over the Izu–Ogasawara (Bonin) arc, which are slightly oblique to the present volcanic front. These anomalies are enhanced on reduced-to-pole and upward-continued anomaly maps. The east row is associated with frontal arc highs (the Shinkurose Ridge), and the west row is accompanied by the Nishi-Shichito Ridge. Another belt of long-wavelength anomalies very similar to the former two occurs over the Kyushu–Palau Ridge. To explain the similarity of the magnetic anomalies, it is proposed that after the spreading of the Shikoku Basin separated the Izu–Ogasawara arc from the Kyushu–Palau Ridge, another rifting event occurred in the Miocene, which divided the Izu–Ogasawara arc into the Nishi-Shichito and Shinkurose ridges. The occurrence of Miocene rifting has also been suggested from the geology of the collision zone of the Izu–Ogasawara arc against the Southwest Japan arc: the Misaka terrain yields peculiar volcanic rocks suggesting back-arc rifting at ∼ 15 Ma. The magnetic anomaly belts over the Izu–Ogasawara arc do not extend south beyond the Sofugan Tectonic Line, suggesting a difference in tectonic history between the northern and southern parts of the Izu–Ogasawara arc. It is estimated that the Miocene extension was directed northeast–southwest, utilizing normal faults originally formed during Oligocene rifting. The direction is close to the final stage of the Shikoku Basin spreading. On a gravity anomaly relief map, northeast–southwest lineaments can be recognized in the Shikoku Basin as well as over the Nishi-Shichito Ridge. We thus consider that lines of structural weakness connected transform faults of the Shikoku Basin spreading system and the transfer faults of the Miocene Izu–Ogasawara arc rifting. Volcanism on the Nishi-Shichito Ridge has continued along the lines of weakness, which could have caused the en echelon arrangement of the volcanoes.

Noble gas concentrations and isotopic compositions have been measured in eight samples of pillow basalt glasses collected from seven different localities along 250 km of the Mariana Trough spreading and rifting axis. The samples have uniform and mid-ocean ridge basalt (MORB)-like ^(3)He/^(4)He values of 9–12 × 10^(–6) (6.4–8.6 times atmospheric) despite large variations in 4He. Concentrations of the noble gases Ne, Ar, Kr, and Xe show much smaller variations between samples, but larger variations in isotopic compositions of Ne, Ar, and Xe. Excess radiogenic ^(21)Ne is observed in some samples. ^(40)Ar/^(36)Ar varies widely (atmospheric to 1880). Kr is atmospheric in composition for all samples. Some samples show a clear excess ^(129)Xe, which is a well-known MORB signature. Isotopic compositions of the heavier noble gases (Ar, Kr, and Xe) in some samples, however, show more atmospheric components. These data reflect the interaction of a MORB-like magma with an atmospheric component such as seawater or of a depleted mantle source with a water-rich component that was probably derived from the subducting slab.

The Izu–Ogasawara arc contains, from east to west, a volcanic front, a back-arc extensional zone (back-arc knolls zone), and a series of across-arc seamount chains that cross the extensional zone in an east-northeast and west-southwest direction and extend into the Shikoku Basin. K–Ar ages of dredged volcanic rocks from these across-arc seamount chains and extension-related edifices in the back-arc region of the Izu–Ogasawara arc were measured to constrain the volcanic and tectonic history of the arc since the termination of spreading in the Shikoku Basin. K–Ar ages range between 12.5 and 1 Ma. Andesitic to dacitic rocks of 12.5–2.9 Ma occur mainly on the western part of the chains. The western part of the chains are the locus of volcanism behind the front which erupted mainly calc-alkaline andesitic lavas. The youngest rocks ( 2.0 wt%), Zr (> 50 p.p.m.) and Y (> 20 p.p.m.) and low CaO ( 12 wt%). The age inferred for the initiation of back-arc rifting (∼ 2.35–2.9 Ma: Taylor 1992) behind the current volcanic arc coincides with the time that basalt chemistry changed drastically (eruption of the low-Na2O and high-CaO basalt). This implies that post-2.8 Ma volcanism in the back-arc knolls zone is associated with rifting. Similarly, the change in chemical composition might be explained by a different type of source mantle following rift initiation. Volcanism in the western seamounts ceased after the onset of rifting at ∼ 2.8 Ma.

Corrosion behavior of mild steel in various hydroxy acid solutions of glycolic, lactic, malic, tartaric, and citric acids was investigated by corrosion tests, electrochemical measurements, solution analysis, and new methods of surface analyses

A novel and amphiphilic 5,10,15,20-tetraphenylporphyrinatoiron complex substituted with phosphocholine groups, 5,10,15,20-tetra{α,α,α,α-o-[2′,2′-dimethyl-20′-(2″-trimethylammonioethyl phosphonatoxy)eicosanamido]phenyl}porphyrinatoiron(II)(lipid-heme), has been synthesized. The lipid-heme formed a stable liposome with a phospholipid. The liposomal lipid-heme reversibly bound oxygen in neutral aqueous media at 37 °C, and its oxygen-binding rate and affinity were similar to those of red blood cells.

Mossbauer spectra, i.r. spectra (Fe–CO stretching), and photodissociation quantum yields of the oxygen and CO adducts were measured for synthetic iron–porphyrin complexes with oxygen transporting ability in aqueous media: the 5,10,15,20-tetra{α-o-[2′,2′-dimethyl-20′-(2″-trimethyl-ammonioethylphosphonatoxy)eicosanamido]phenyl}porphyrinatoiron(II)(lipid-heme) complex of 1-laurylimidazole (lauryl = dodecyl) or 1-lauryl-2-methylimidazole embedded in the bilayer of phospholipid liposome (abbreviated as liposome–lipid-heme) and the tetradecyl-substituted copper–iron(II)–diporphyrin (diheme) complex of 1-laurylimidazole solubilized in a surfactant micelle (micelle–diheme). The quadrupole splitting (ΔEQ) for the CO adduct of the diheme indicated a large electric-field gradient at the iron nucleus, probably due to steric hindrance of the diheme structure. Its CO-stretching vibration (νCO) and photodissociation quantum yield (Φ), obtained by flash photolysis, were similar to those of carboxy hemoproteins and suggested the distorted ligation of CO to Fe. Mossbauer parameters for the oxygen adducts of liposome–lipid-heme and micelle–diheme in aqueous media agreed with those for the oxy hemoproteins.

Activation parameters have been determined for the binding of oxygen to 5,10,15,20-tetra{α-o-[2′,2′-dimethyl-20′-(2″-trimethylammonioethylphosphonatoxy)eicosanamido]phenyl}porphyrinato-iron(II)(lipid-heme) and 5,10,15,20-tetra(α-o-pivalamidophenyl)porphyrinatoiron(II)(heme) complexes of 1-lauryl-2-methylimidazole embedded in the bilayer of phospholipid liposome (abbreviated liposome-embedded lipid-heme and heme, respectively). Activation parameters, ΔH‡on and ΔS‡on, for the liposome-embedded lipid-heme were consistent with those of hemoglobin and myoglobin, but those for the liposome-embedded heme were similar to those of red blood cells. A potential energy diagram and binding pathway for the oxygen-binding reaction to the Iiposome-embedded lipid-heme and to the liposome-embedded heme are discussed in comparison with those of hemoglobin.

Rate parameters for oxygen and carbon monoxide binding to a liposome-embedded heme were measured under physiological conditions (pH 7.0 at 37 °C) by stopped-flow spectrophotometry. The rate constants were similar to those of red blood cells in suspension. It is concluded that liposome-embedded heme is a suitable model to study the binding of gaseous molecules to red blood cells.

The oxygen-binding affinity (p½; oxygen pressure at 50% binding for the heme) of a heme derivative embedded in a bilayer of natural phospholipid liposomes was influenced by the solution pH: the p½ value of the liposome–lipid-heme increased with pH {Bohr coefficient, r=d[log(p½)]d(pH)=+0.09 to +0.32}, which is the reverse of the Bohr effect for hemoglobin. This pH dependence was affected by the composition of the liposome–lipid-heme. Its mechanism is discussed in relation to the surrounding lipid bilayer structure and protonation equilibrium of the imidazole ligand. pH-induced oxygen-uptake and -evolution was observed, in a process which was sensitive to ±1 unit of pH change at pH 7.