C-H Arylation of Benzene with Aryl Halides using H2 and a Water-Soluble Rh-Based Electron Storage Catalyst.

This paper reports the first example of C-H arylation of benzene under mild conditions, using H2 as an electron source {turnover numbers (TONs)=0.7-2.0 for 24 h}. The reaction depends on a Rh-based electron storage catalyst, and proceeds at room temperature and in aqueous solution. Furthermore, the H2 is inactive during the radical transfer step, greatly reducing unwanted side reactions.

Reductive C(sp3)-C(sp3) homo-coupling of benzyl or allyl halides with H2 using a water-soluble electron storage catalyst.

This paper reports the first example of a reductive C(sp3)-C(sp3) homo-coupling of benzyl/allyl halides in aqueous solution by using H2 as an electron source {turnover numbers (TONs) = 0.5-2.3 for 12 h}. This homo-coupling reaction, promoted by visible light, is catalysed by a water-soluble electron storage catalyst (ESC). The reaction mechanism, and four requirements to make it possible, are also described.

Thermal and Chemical Stabilization of Silver Nanoplates for Plasmonic Sensor Application.

Thermal and chemical stabilities of silver nanoplates (AgPLs), which are triangle plate-shaped silver nanoparticles, were improved by coating with titanium oxide. The titanium oxide layer prepared by a dip-coating method was certainly advantageous for the improvement of thermal stability. Furthermore, the overlayering of titanium oxide by a spray pyrolysis method was quite useful for improving the chemical stability against I(-) exposure. Such a coating exhibited satisfactory refractive index sensitivities.

Temperament and character as predictors of recurrence in remitted patients with major depression: a 4-year prospective follow-up study.

The aim of the present study was to examine whether the specific personality traits, Harm-Avoidance (HA) and Self-Directedness (SD) as measured by the Temperament and Character Inventory (TCI), were predictive for subsequent depressive episodes in remitted patients with major depressive disorders (MDDs) over a 4-year follow-up. A total of 109 inpatients with MDD participated in this study. The subjects completed the TCI when they were assessed to be in remission. They were divided into high or low HA groups and high or low SD groups, as discriminated by the quartile value. A total of 69 patients were followed-up over a 4-year period or until recurrence. Both Kaplan-Meier analysis and Cox׳s proportional hazards regression analysis indicated that patients with a low SD score had a significantly shorter time to recurrence from remission than patients with a high SD score even when some prognostic predictors were controlled for. In contrast, HA was not found to be a predictor of recurrence for future depressive episodes. A part of MDD patients with low scores in Self-Directedness are likely to develop depression over a subsequent period of time. Interventions that improve SD may help to delay recurrence of depression in MDD patients.

Podocyte injury-driven intracapillary plasminogen activator inhibitor type 1 accelerates podocyte loss via uPAR-mediated ß1-integrin endocytosis.

Podocyte-endothelial cell cross-talk is paramount for maintaining the filtration barrier. The present study investigated the endothelial response to podocyte injury and its subsequent role in glomerulosclerosis using the podocyte-specific injury model of NEP25/LMB2 mice. NEP25/LMB2 mice showed proteinuria and local podocyte loss accompanied by thrombotic microangiopathy on day 8. Mice showed an increase of glomerular plasminogen activator inhibitor type 1 (PAI-1) mRNA and aberrant endothelial PAI-1 protein already on day 1, before thrombosis and proteinuria. A PAI-1-specific inhibitor reduced proteinuria and thrombosis and preserved podocyte numbers in NEP25/LMB2 mice by stabilization of ß1-integrin translocation. Heparin loading significantly reduced thrombotic formation, whereas proteinuria and podocyte numbers were unchanged. Immortalized podocytes treated with PAI-1 and the urokinase plasminogen activator (uPA) complex caused significant cell detachment, whereas podocytes treated with PAI-1 or uPA alone or with the PAI-1/uPA complex pretreated with an anti-uPA receptor (uPAR) antibody failed to cause detachment. Confocal microscopy and cell surface biotinylation experiments showed that internalized ß1-integrin was found together with uPAR in endocytotic vesicles. The administration of PAI-1 inhibitor or uPAR-blocking antibody protected cultured podocytes from cell detachment. In conclusion, PAI-1/uPA complex-mediated uPAR-dependent podocyte ß1-integrin endocytosis represents a novel mechanism of glomerular injury leading to progressive podocytopenia. This aberrant cross-talk between podocytes and endothelial cells represents a feedforward injury response driving podocyte loss and progressive glomerulosclerosis.

Effects of silver nanoparticles with different sizes on photochemical responses of polythiophene-fullerene thin films.

Effects of size and coverage density of silver nanoparticles (AgPs) on the fluorescence emission and fluorescence lifetime of poly(3-hexylthiophene-2,5-diyl) (P3HT) thin films were investigated. AgPs of 64 nm diameter showed greater effects on the fluorescence decay process of P3HT films as compared with 7 nm AgPs. The fluorescence lifetime (FL) of P3HT decreased from 0.61 to 0.22 ns in the presence of 64 nm AgPs, while no appreciable change (0.60 ns) was seen in the case of 7 nm AgPs. The results suggest that the 64 nm AgPs showed a greater effect on the enhancement of the decay rate of excited P3HT. The photoelectric conversion of thin films consisting of P3HT and phenyl-C61-butyric acid methyl ester (PCBM) was also investigated. AgPs of 7 or 64 nm diameters were first deposited on indium-tin-oxide substrates with controlled surface coverage densities from ~1 to 40%. When the coverage densities of deposited AgPs were ~20% for both 7 and 64 nm, the enhancement of photoelectric conversion efficiency reached maximum. The degree of enhancement in the case of 64 nm AgPs was larger than in the case of 7 nm AgPs.

Gold cluster-nanoparticle diad systems for plasmonic enhancement of photosensitization.

Quantum-sized gold clusters are deposited on TiO2 both as a photosensitizer and catalyst, and coupled to plasmonic gold nanoparticles as a light harvesting antenna. Photocurrent enhancement was observed for Au25(SG)18 and Au38(SG)24 but not for Au102(SG)44 (SG = glutathione). The maximum enhancement factor of ~9 is reached at 900 nm.

Gold nanorods embedded in titanium oxide film for sensing applications.

We succeeded in fabricating a localized surface plasmon resonance (LSPR) sensor comprising gold nanorods (AuNRs) that were immobilized in a thin film of titanium oxide. First, AuNRs were electrostatically immobilized onto a glass substrate; then, dip-coating of the thin titanium oxide film was carried out. These procedures were realized to prepare well-dispersed AuNRs onto a substrate with a uniform titanium oxide layer. The titanium-oxide-coated AuNRs could retain their rod-shape, even after annealing at 300°C for 1 h, since titanium oxide effectively prevented any heat-induced shape change of the AuNRs. The peak shifts of the plasmon bands of the immobilized AuNRs were observed with the change in the environmental refractive indices, even after titanium oxide coating. In addition, the as-prepared titanium oxide layer exhibited photocatalytic activity for methylene blue dye molecule under UV irradiation. This suggests that the titanium-oxide-coated AuNRs can conveniently be reusable even for unwanted contamination with organic compounds, due to their photocatalytic decomposition with UV light.

Electropolymerized polythiophene photoelectrodes with density-controlled gold nanoparticles.

A polythiophene thin film was fabricated on gold nanoparticle (AuNP)-deposited indium-tin-oxide (ITO) electrodes with electropolymerization, whereas AuNPs were predeposited on the ITO surface. A photocurrent via photoexcited polythiophene increased with AuNPs which was attributed to the localized surface plasmon resonance. Investigation of the AuNP-density dependence on the relative enhancement of photocurrent revealed the maximum effect at 14% of AuNP-density, while 68% of AuNP-density exhibited smaller photocurrent than the polythiophene electrode without AuNPs. We have revealed that the effects of AuNPs saturate in the fairly low density region, and that the excess AuNPs even in the range of submonolayer resulted in the decrement of photocurrents.

Enhancement of dye-sensitized photocurrents by gold nanoparticles: effects of dye-particle spacing.

Photocurrents of a ruthenium dye-TiO(2) system are enhanced by gold nanoparticles (100 or 40 nm diameter) embedded in TiO(2). As dye-particle spacing decreases to 10 nm, enhancement factor and intensity of localized electric fields at the TiO(2) surface increase. A further decrease in the spacing suppresses the enhancement.

Anisotropic light absorption by localized surface plasmon resonance in a thin film of gold nanoparticles studied by visible multiple-angle incidence resolution spectrometry.

Anisotropic light absorptions via localized surface plasmon resonance in a gold-evaporated film parallel (in-plane; IP) and perpendicular (out-of-plane; OP) to the film surface are studied using visible multiple-angle incidence resolution spectrometry (Vis-MAIRS). When the thin film was aged for eighteen days, the time-dependent Vis-MAIRS IP spectra exhibited significantly different variation from that of the OP spectra: the IP spectra exhibited a large shift to the shorter wavelength side, whereas the OP spectra were explained by a linear combination of three-constituent spectra. The surface topographical analysis of the film revealed that a continuous film coalesced to form aggregates of metal particles. The intrinsic difference between the IP and OP spectra was readily elucidated by considering the surface-parallel and -perpendicular dipoles interaction depending on the topographical changes, which was confirmed by performing spectral simulation using metal particle array models.

Electrodeposition of thermally stable gold and silver nanoparticle ensembles through a thin alumina nanomask.

Hemispheric gold or silver nanoparticle (Au and AgNP) ensembles were electrodeposited on a smooth ITO electrode through a thin Al(2)O(3) nanomask. The nanomask reduced the deviation in the particle size and interparticle distance. The absorption peak based on localized surface plasmon resonance (LSPR) of the AuNP ensemble redshifted with increasing environmental refractive index, suggesting that the ensemble would be used as a LSPR sensor for chemical analysis and bioanalysis. The Al(2)O(3) nanomask prevented the Au and AgNPs from thermal coalescence even at 500 degrees C, and consequently, it improved thermal stabilities of nanoparticle ensembles. The ensembles exhibit LSPR-based absorption peak in the visible region, even after annealing. The nanomask allowed AgNPs, which are thermally and chemically less stable than AuNPs, to be coated with sintered TiO(2). The ITO/AgNP/TiO(2) electrode thus obtained functions as a photocathode on the basis of photoinduced electron transfer from silver nanoparticles to TiO(2).

Oxidation of methanol and formaldehyde to CO2 by a photocatalyst with an energy storage ability.

A TiO(2)-Ni(OH)(2) bilayer photocatalyst is known as a photocatalyst with energy storage abilities. Oxidative energy from the UV-irradiated TiO(2) underlayer can be stored in the Ni(OH)(2) overlayer. We investigated oxidation and mineralization of methanol and formaldehyde by the stored oxidative energy by mean of gas chromatography. When the methanol concentration in air is as low as 10 ppm, the mass conversion efficiency from methanol to CO(2) is approximately 86%. Formaldehyde can also be oxidized to CO(2) by the stored energy.

Plasmon-resonance-based generation of cathodic photocurrent at electrodeposited gold nanoparticles coated with TiO2 films.

Reversed photoresponse: Indium tin oxide (ITO)/Au nanoparticle (NP)/TiO(2) electrodes (see picture) exhibit cathodic photocurrents and positive photopotentials under visible light, whereas ITO/TiO(2)/Au NP electrodes show an inverted response. This behavior indicates that electron transfer occurs from the plasmon-excited Au NPs to the TiO(2) film. An enhanced O(2) photoreduction activity is found for ITO/Au NP/TiO(2)/Pt electrodes.

Remote energy storage in Ni(OH)2 with TiO2 photocatalyst.

Oxidative energy generated by UV-irradiated TiO2 photocatalyst was stored in Ni(OH)2 that was 12.5-50 microm apart from the TiO2. It is likely that active oxygen species generated on TiO2 diffused into the gas phase and oxidized Ni(OH)2. Loading the TiO2 with Pt accelerated the remote energy storage by an order of magnitude. It was revealed that the stored energy could be taken out and used chemically or electrochemically. The oxidized Ni(OH)2 was reduced by gaseous formaldehyde, formate, ethanol and H2O2.

Oxidative energy storage ability of a TiO2-Ni(OH)2 bilayer photocatalyst.

A TiO2-coated indium tin oxide electrode was further coated with Ni(OH)2 by electrodeposition to obtain a TiO2-Ni(OH)2 bilayer film. Upon irradiation of the bilayer film with UV light in a pH 10 buffer, the Ni(OH)2 layer was oxidized, and it turned from colorless to brown; oxidative energy was stored in the layer. The potential of the oxidative energy thus stored was about +0.7 V versus Ag|AgCl. The stored energy could be reversibly taken out of the film by chemical and electrochemical means. The photooxidized Ni(OH)2 was rereduced by alcohols, aldehydes, phenol, I-, H2O2, formate, and acetone.