Fock space representations of affine lie algebras and integral representations in the Wess-Zumino-Witten models

Fock space representations of affine Lie algebras are studied. Explicit forms of correction terms adding to the currentsF _i (z) are determined. It is proved that the Sugawara energy-momentum tensor on the Fock spaces is quadratic in free bosons. Furthermore, screening operators are constructed. This implies the existence of generalized hypergeometric integrals satisfying the Knizhnik-Zamolodchikov equation.     

Interaction analysis of the carcinoembryonic antigen (CEA) with its monoclonal antibody immobilized on a gold surface using Fourier transform infrared reflection-absorption spectroscopy (FT-IR RAS).

A monoclonal antibody for the carcinoembryonic antigen (CEA) was immobilized on a gold chip surface covered by a self-assembled monolayer of 11-mercaptoundecanoic acid. Upon the addition of CEA, a Fourier transform infrared reflection-absorption spectroscopy (FT-IR RAS) measurement showed an increased absorption at around 1500 - 1700 cm(-1), corresponding to its amide structures. Another addition of CEA polyclonal antibody on this chip caused a further increase of the absorption in this region only after a treatment with CEA. This result shows that an antibody-fixed gold surface coupled with an FT-IR RAS measurement provides a new tool for detecting the antibody-antigen interaction.     

Reversible Boron-Insertion into Aromatic C−C Bonds

Formation of borabicyclo[3.2.0]heptadiene derivatives was achieved via boron-insertion into aromatic C−C bonds in the photo-promoted skeletal rearrangement reaction of triarylboranes bearing an ortho-phosphino substituent (ambiphilic phosphine-boranes). The borabicyclo[3.2.0]heptadiene derivatives were fully characterized by NMR and X-ray analyses. The dearomatized products were demonstrated to undergo the reverse reaction in the dark at room temperature, realizing photochemical and thermal interconversion between triarylboranes and boron-doped bicyclic systems. Experimental and theoretical studies revealed that sequential two electrocyclic reactions involving E/Z-isomerization of an alkene moiety proceed via a highly strained trans-borepin intermediate.     

Molecular-Level Reinforced Adhesion Between Rubber and PTFE Film Treated by Atmospheric Plasma Polymerization

Extremely strong reinforced adhesion between a polytetrafluoroethylene (PTFE) film and butyl rubber is achieved using an atmospheric pressure plasma graft polymerization, involving argon and acrylic acid vapor. The treated PTFE film is then placed over a raw butyl rubber plate and hot-pressed under 157 N/cm² for 40 min at 150 °C or for 10 min at 180 °C. This procedure results in molecular-level or chemical adhesion between the butyl rubber and the PTFE film. The 180° peeling test results show that a high peeling strength of 3.9 N, per 1 mm sample width, is achieved. Adherend failure of the rubber sheet occurs when the peeling is enforced. From X-ray photoelectron spectroscopy analysis of the treated films, chemical bonds with fluorine atoms are absent from the surface. From scanning electron microscopy analysis, a transparent hydrophilic poly(acrylic acid) layer composed of nanoscale spherical particles is formed. This PTFE-rubber composite material is suitable for high-quality, prefilled medical syringe gaskets.     

Synthesis of porphyrin dimers fused with a benzene unit

Bicyclo[2.2.2]octadiene-connected pyrrolo-porphyrins have been prepared by an inverse-type [3+1] porphyrin synthesis of a bicyclo[2.2.2]octadiene-fused dipyrrole with a tripyrrane dicarbaldehyde. Another [3+1] porphyrin synthesis of pyrrole-connected porphyrins with the same or other tripyrrane dicarbaldehydes gave bicyclo[2.2.2]octadiene-bridged diporphyrins, the central metals and/or peripheral substituents of which were different. Thermal decomposition of the bicyclo[2.2.2]octadiene skeleton to a benzene moiety gave pi-system-fused porphyrin dimers in a highly pure form.     

Photochromism of mixed crystals containing bisthienyl-, bisthiazolyl-, and bisoxazolylethene derivatives

Single crystals composed of two or three different kinds of diarylethenes, having similar geometrical structures but different colors in the closed-ring isomers, 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a), 1,2-bis(5-methyl-2-phenyl- 4-thiazolyl)perfluorocyclopentene (2a), and 1,2-bis(5-methyl-2-phenyl-4-oxazolyl)perfluorocyclopentene (3a) have been prepared in an attempt to form single crystals which exhibit different colors, depending on illumination wavelengths. When 1a and 2a are mixed in ethanol and the content of 2a in the feed is higher than that of 1a, only a needle-shaped crystal is obtained. The crystal shape is similar to that of 2a. On the other hand, high content of 1a in the feed leads to formation of a block-shaped crystal, of which the shape is similar to that of 1a. At a feed ratio of 1:1 for 1a and 2a, two types of crystals such as needle- and block-shapes are obtained from the same batch. Mixed crystals composed of three kinds of derivatives 1a/2a/3a have also been prepared. A crystal composed of the three derivatives in the molar ratio of 32 (1a):53 (2a):15 (3a) was obtained. X-ray analysis proved that 1a and 3a are packed in the crystal lattice of 2a. The mixed crystal 1a/2a/3a changed color from colorless to yellow, red, and blue upon irradiation with light of appropriate wavelengths.     

Ca2+ Regulates ERp57-Calnexin Complex Formation

ERp57, a member of the protein disulfide isomerase family, is a ubiquitous disulfide catalyst that functions in the oxidative folding of various clients in the mammalian endoplasmic reticulum (ER). In concert with ER lectin-like chaperones calnexin and calreticulin (CNX/CRT), ERp57 functions in virtually all folding stages from co-translation to post-translation, and thus plays a critical role in maintaining protein homeostasis, with direct implication for pathology. Here, we present mechanisms by which Ca²⁺ regulates the formation of the ERp57-calnexin complex. Biochemical and isothermal titration calorimetry analyses revealed that ERp57 strongly interacts with CNX via a non-covalent bond in the absence of Ca²⁺. The ERp57-CNX complex not only promoted the oxidative folding of human leukocyte antigen heavy chains, but also inhibited client aggregation. These results suggest that this complex performs both enzymatic and chaperoning functions under abnormal physiological conditions, such as Ca²⁺ depletion, to effectively guide proper oxidative protein folding. The findings shed light on the molecular mechanisms underpinning crosstalk between the chaperone network and Ca²⁺.     

Hydrothermal synthesis of spinel Li1+x Mn2O4 as cathode material for rechargeable lithium battery

Abstract

The hydrothermal synthesis of Li-Mn spinel oxide (Li_1+xMn₂O₄) was undertaken in order to develop high quality, low cost cathode material for a rechargeable lithium battery. In our experiments, γ-MnOOH, LiOH · H₂O and H₂O₂ were used as starting materials to synthesize Li-Mn spinel oxide under hydrothermal conditions of 180-230°C and about 1.0-2.8 MPa. The chemical composition and particle size of the Li_1+xMn₂O₄ is easily controlled in the hydrothermal reaction. The Li_1+xMn₂O₄ produced was characterized by X-ray diffraction, with the spinel phase having a Li/Mn ratio of 0.50-0.60. There is convincing evidence, as a result of this work, that our synthesis process is most suitable for producing high quality cathode material that can be used in a rechargeable lithium battery.     

Development of continuous hydrothermal hot-pressing apparatus

Abstract

A process for continuous hydrothermal hot-pressing has been examined, with the resultant development of a new continuous hydrothermal hot-pressing apparatus. In this study, amorphous siliceous material, slaked lime and pulp fiber were mixed and solidified, at 200°C, to produce a board product. The duration of the hydrothermal hot pressing reaction process was 17 minutes. The bending strength of the board product was high; 11MPa.