The Clinical Significance of Phosphorylated Heat Shock Protein 27 (HSPB1) in Pancreatic Cancer

Pancreatic cancer is one of most aggressive forms of cancer. After clinical detection it exhibits fast metastatic growth. Heat shock protein 27 (HSP27; HSPB1) has been characterized as a molecular chaperone which modifies the structures and functions of other proteins in cells when they are exposed to various stresses, such as chemotherapy. While the administration of gemcitabine, an anti-tumor drug, has been the standard treatment for patients with advanced pancreatic cancer, accumulating evidence shows that HSP27 plays a key role in the chemosensitivity to gemcitabine. In addition, phosphorylated HSP27 induced by gemcitabine has been associated with the inhibition of pancreatic cancer cell growth. In this review, we summarize the role of phosphorylated HSP27, as well as HSP27, in the regulation of chemosensitivity in pancreatic cancer.     

Emission and charge transport properties of thiophene-terminated thiophene/phenylene co-oligomer crystals

We have grown the crystals of two thiophene/phenylene co-oligomers (TPCOs) composed of in-line five and seven alternating thiophene and benzene rings. These TPCOs are characterized by thiophenes located at both molecular terminals. The grown crystals had several pairs of parallel crystal faces that function as optical resonators. These produced interference fringes in their emission and reflectance spectra. We measured the emission spectra in both weak broadband excitation and intense laser excitation regimes. From these spectra we determined the phase refractive index dispersion and the anisotropic group refractive indices. We made field-effect transistor devices using the above TPCO crystals and carried out their electrical measurements. These optical and charge transport properties are compared with those of crystals of other alternating TPCOs with phenylenes located at both molecular terminals.     

Microscale Contacting of Two Immiscible Liquid Droplets to Measure Interfacial Tension

In various microfluidic devices, surface tension and interfacial tension values are necessary to analyze the fluid behavior in microchannels, and evaluating the values of interfacial tension is especially important for gas–liquid and liquid–liquid flows. A pendant drop method is commonly used to measure the interfacial tension value; however, the pendant drop method requires strict accuracy in measuring the droplet size when the droplet has a nonspherical shape, as well as an accurate value of the density difference between the two liquids. In this work, a new measurement method called the “liquid bridge-inducing microscale contact method” has been developed in which the interfacial tension can be obtained from the bridging of two liquid droplets extruded from opposing ends of glass capillary tubes or formed on the ends of round metal rods. By measuring the radii of curvature of each liquid surface and interface, we calculate the Laplace pressure on the surface and interface, and derive the interfacial tension value using the Laplace equation. The results show that the values of interfacial tension obtained from the two methods are approximately the same and that the liquid bridge-inducing microscale contact method is capable of accurate interfacial tension measurements.     

Solid insulated switchgear and investigation of its mechanical and electrical reliability

SF₆ gas is widely employed in medium‐voltage switchgear because of its high insulation reliability and down‐sizing ability. However, SF₆ gas was placed on the list of greenhouse gases under the Kyoto Protocol in 1997. Since then, research on low‐SF₆ or SF₆‐free insulation has been carried out actively. Therefore, we focused on solid materials with higher dielectric strength than SF₆, and we have now developed solid insulated switchgear (SIS) that uses molding of all main circuits. A new epoxy casting material is used which contains a large amount of spherical silica and a small amount of rubber particles. This new material has high mechanical strength, high thermal resistance, high toughness, and also high dielectric strength because of direct molding of the vacuum bottle, as well as reduced size and high reliability. This paper describes the technology of the new epoxy casting material which makes possible SIS. In addition, mechanical and electrical reliability tests of SIS using a new epoxy resin were performed, and the effectiveness of the developed material and the mechanical and electrical reliability of the SIS were verified. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 28–36, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21057     

Characterization of the anionic polymerization of 2-(ethoxy)ethyl methacrylate by t-C4H9MgBr in toluene

Anionic polymerizations of 2-(ethoxy)ethyl methacrylate (EOEMA) were carried out under several conditions that allowed for living polymerization of methyl methacrylate (MMA). It was found that the polymerization rate of EOEMA by t-C₄H₉MgBr in toluene was much lower than that of MMA under these conditions. However, the polymerization rate of EOEMA by t-C₄H₉MgBr in tetrahydrofuran was not much lower than the polymerization of MMA. Interactions between the counter cation (magnesium) and the ether oxygen of the ester moiety in the EOEMA unit are considered important to delay the polymerization. Random and block copolymerizations of EOEMA and MMA by t-C₄H₉MgBr in toluene were also carried out and the results support the interaction of ether oxygen. 4-(Ethoxy)butyl methacrylate (EOBMA) was successfully prepared from 4-ethoxy-1-butanol and methacryloyl chloride and purified. Polymerization of EOBMA with t-C₄H₉MgBr in toluene provides a polymer with good yield, suggesting that the number of carbon atoms between the ester group and the ether oxygen is important to the interactions with the ether oxygen. Some of the thermal properties of the polymers and copolymers, including their glass transition temperature and thermal stability, were also evaluated.     

Experimental study on the reaction rate of a second‐order chemical reaction in a planar liquid jet

Instantaneous concentrations of reactive species are simultaneously measured in a planar liquid jet with a second‐order chemical reaction to investigate the statistical properties of the chemical reaction rate and the validity of models which have been proposed for concentration correlation. The jet flow contains the reactant A, and the ambient flow contains the reactant B. The results show that the concentration correlation of the reactants makes a negative contribution to the mean reaction rate, and this contribution is important in the downstream direction. The concentration correlation changes owing to the chemical reaction. The effects of the chemical reaction on the concentration correlation change with the flow location and the Damköhler number. The concentration correlation predicted by the Toor's model and the three‐environment model are compared with the experimental results. The results show that these models fail to accurately estimate the concentration correlation. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3969–3988, 2014     

Reinvestigation of Thermoelectric Properties of n- and p-Type Ba8−d Au x Si46−x−y Clathrate

We have synthesized n- and p-type clathrates Ba_8?d Au _x Si_46?x?y with various Au contents (4.6 < x < 6.0) by arc-melting, annealing at 1173 K, and spark plasma sintering at 1073 K. The Au compositions found by wavelength-dispersive x-ray spectrometry for the synthesized samples were slightly lower than the nominal compositions. Ba_7.8Au_4.6Si_41.4 and Ba_7.7Au_4.9Si_41.1 samples showed n- and p-type conduction, respectively. According to the electron count (Ba²⁺)₈Au(^3?)_5.33Si_40.67, the clathrate composition with x = 5.33 is expected to be an intrinsic semiconductor. Our experimental results show that increase of the Au composition causes a transition from n-type to p-type conduction between x = 4.6 and 4.9. We have also calculated the band structures of the Ba₈Au _x Si_46?x clathrate including a vacancy by ab initio calculation based on density functional theory with structure optimization. It was found that the vacancy behaves like an electron acceptor and the numbers of vacancies at 24k sites for the synthesized Ba₈Au _x Si_46?x?y clathrates can be estimated as ～0.4 in a unit cell.