Enhancement of photocurrents due to the oxidation of water and organic compounds at BiZn2VO6 particulate thin film electrodes by treatment with a TiCl4 solution

Photocurrents due to water oxidation at BiZn₂VO₆ (E_g 2.4 eV) particulate thin film electrodes were largely enhanced by pre-treatment with an aqueous TiCl₄ solution. Photocurrents for BiZn₂VO₆ electrodes with no TiCl₄ treatment were also enhanced by the addition of organic compounds such as methanol and trimethyl amine to the aqueous electrolyte. Interestingly, such enhanced photocurrents by organic compounds were further enhanced by the TiCl₄ pre-treatment. EDAX and SEM investigations showed the formation of a flock-like TiO₂ overlayer on BiZn₂VO₆ particles after the TiCl₄ treatment. The photocurrent enhancement by the TiCl₄ pre-treatment is thus mainly attributed to the necking effect of the flock-like TiO₂ overlayer, which facilitates the transport of photogenerated electrons within the BiZn₂VO₆ particulate thin film electrode.     

Expression and Prognostic Significance of CD47–SIRPA Macrophage Checkpoint Molecules in Colorectal Cancer

Despite the confirmed anti-cancer effects of T-cell immune checkpoint inhibitors, in colorectal cancer (CRC) they are only effective in a small subset of patients with microsatellite-unstable tumors. Thus, therapeutics targeting other types of CRCs or tumors refractory to T-cell checkpoint inhibitors are desired. The binding of aberrantly expressed CD47 on tumor cells to signal regulatory protein-alpha (SIRPA) on macrophages allows tumor cells to evade immune destruction. Based on these observations, drugs targeting the macrophage checkpoint have been developed with the expectation of anti-cancer effects against T-cell immune checkpoint inhibitor-refractory tumors. In the present study, 269 primary CRCs were evaluated immunohistochemically for CD47, SIRPA, CD68, and CD163 expression to assess their predictive utility and the applicability of CD47–SIRPA axis-modulating drugs. Thirty-five percent of the lesions (95/269) displayed CD47 expression on the cytomembrane of CRC cells. CRCs contained various numbers of tumor-associated immune cells (TAIs) with SIRPA, CD68, or CD163 expression. The log-rank test revealed that patients with CD47-positive CRCs had significantly worse survival than CD47-negative patients. Multivariate Cox hazards regression analysis identified tubular-forming histology (hazard ratio (R) = 0.23), age < 70 years (HR = 0.48), and high SIRPA-positive TAI counts (HR = 0.55) as potential favorable factors. High tumor CD47 expression (HR = 1.75), lymph node metastasis (HR = 2.26), and peritoneal metastasis (HR = 5.80) were cited as potential independent risk factors. Based on our observations, CD47–SIRPA pathway-modulating therapies may be effective in patients with CRC.     

The risk of hepatitis C virus infection among blood donors in Osaka, Japan

A 70-year-old male presented with a plasma cell granuloma extending from the extracranial to the intracranial space. Findings of preoperative magnetic resonance imaging and intraoperative observation indicated that the lesion extended from the temporal muscle to the subarachnoid space, penetrating the frontal bone. The subarachnoid lesion was composed of neutrophils indicating the presence of acute or subacute inflammation. The final diagnosis of the resected tumor was plasma cell granuloma. High levels of antibodies against Epstein-Barr (EB) virus in the cerebrospinal fluid and the immunohistochemical demonstration of EB nuclear antigens in the plasma cell granuloma suggested that EB virus infection was associated with the development of plasma cell granuloma in this patient.     

Heat deterioration of phospholipids. V. A new rearrangement reaction of sugars and phosphatidylethanolamine

Novel four 2,3-dihydro-1H-imidazo[1,2-a]pyridine-4-ylium derivatives were obtained with increase of UV absorption at 350 nm and browning of the solution by heating paste lecithin from soybean (SL) in octane. These four derivatives were formed by reaction of one molar of any sugar except 2-deoxysugars with two molar of phosphatidylethanolamines (PE) in SL. To confirm the reaction mechanism, several (13)C-labeled-sugars were reacted with 1,2-di-O-stearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE), respectively. These reactants clearly showed that five carbons of the pyridinium ring and one carbon of the substituted group were based on those of a sugar and that the formation of the pyridinium derivatives was accompanied with cleaving between the carbons of 1- and 2-positions in the sugar and rearrangement. This reaction is a new rearrangement reaction and we named it "new pseudo Maillard rearrangement reaction".     

Medical cuneiform fracture-dislocation associated with medial and intermediate cuneiform fractures

We report the microbiological characteristics of two Rahnella aquatilis strains isolated in the faeces of two patients with acute gastroenteritis, one of whom is an AIDS patient. The biochemical behaviour was studied with different automated identification systems, and the few clinical cases to be found in the literature were reviewed. Of the nine strains isolated in clinical samples, two were obtained from blood cultures, two from respiratory samples, one from urine, one from a burn wound, one from a surgical wound, and two (our strains) from faeces. In almost all cases the patient presented an underlying condition facilitating infection by opportunistic microorganisms. The majority of strains are characterized by their resistance to ampicillin, cephalothin and cefoxitin. Due to the rarity of the isolation of R. aquatilis in human samples it is not yet possible to establish, with any degree of certainty, its true pathogenic capacity.     

Heat deterioration of phospholipids. VI. Clarification of mechanism for the new pseudo Maillard rearrangement reaction by using 2-aminoethyl dihydrogenphosphate

2,3-Dihydro-1H-imidazo[1,2-a]pyridine-4-ylium derivatives with UV absorption at 350 nm were formed by reaction of one molar of any sugar except 2-deoxysugars with two molar of phosphatidylethanolamines involving a new pseudo Maillard rearrangement reaction. To elucidate the reaction mechanism, 2-aminoethyl dihydrogenphosphate, which had a partially similar structural moiety to PE, was reacted with D-galactose. Though the UV absorption at 365 nm was not observed and the four pyridinium derivatives were also not formed in the reactant solution, the UV absorption at 286 nm and browning of the reactant solution were observed. From this reactant solution, two compounds with lambdamax at 283 nm and 297 nm were isolated and former was determined as 5-(hydroxymethyl)furfural (HMF) and later did as phosphoric acid mono{2-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]ethyl}ester (PMPEE), which is a new compound, respectively. Because reaction of PMPEE with PE leads to form the pyridinium derivatives, we concluded that a compound like PMPEE was one of intermediates in this new reaction.     

Two-dimensional crystal growth of thermally converted organic semiconductors at the surface of ionic liquid and high-mobility organic field-effect transistors

We report a novel solution-crystallization method to grow two-dimensional platelet-shaped single-crystals of well-known insoluble organic semiconductors via thermal conversion of their precursor molecules dissolved in ionic liquids (ILs). By optimizing conditions of the crystal growth regarding physical properties of ILs such as density and viscosity, we successfully and reproducibly obtained thin platelets of pentacene and dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) single-crystals, with which nearly the best performing field-effect transistors are constructed for the two compounds. The prompt and simple technique has opened the way to use practically insoluble organic semiconductor materials for high-performance printed electronics, which enables mass-producible and large-area organic circuitry devices.     

Impact of Pd nanoparticle loading method on SnO2 surface for natural gas detection in humid atmosphere

To improve the sensor response to low concentrations of methane (CH₄) at low operating temperatures in humid atmospheres, we prepared Pd-loaded SnO₂ (Pd-SnO₂) nanoparticles via two different Pd-loading processes: (i) a general impregnation method and (ii) a new loading method using poly(N-vinyl-2-pyrrolidone) (PVP) as a protective agent for Pd receptor particles. According to the measured electric resistances, the Pd particles limited the hydroxyl-poisoning of the SnO₂ particle surface. Because Pd is oxidized to PdO, a p–n junction is formed at the interface between PdO and SnO₂, and such interface gives the enlargement of the electron depletion layer. Therefore, Pd further improved the resistance against hydroxyl poisoning of the SnO₂ surface in humid air. In addition, although the sensor based on neat SnO₂ did not respond to low-concentration CH₄ at 200–400 °C, both the sensors based on the Pd-loaded SnO₂ samples exhibited high sensor response to 200 ppm CH₄ in a humid atmosphere. The Pd-SnO₂ obtained by the new loading method exhibited a higher response to CH₄ at lower concentrations in the lower operating temperature range (200–250 °C). This improvement in the sensor response is probably due to the catalytic activity of the larger Pd nanoparticles. According to high-resolution transmission electron microscopy–energy-dispersive X-ray spectroscopy images, the new loading method successfully provided Pd-loaded SnO₂ nanoparticles with Pd nanoparticles dispersed uniformly on the SnO₂ particle surface. The average particle size of Pd nanoparticles loaded on the surface of SnO₂ by the new loading method was slightly larger than that of the Pd nanoparticles loaded by the impregnation method. As the Pd particle size increases, it is thought that crystalline PdO particles are formed more easily, thereby improving the combustion activity of CH₄ under humid conditions. These results are of great significance for further decreasing the energy consumption of the CH₄ sensor and increasing its sensor response in humid atmospheres.