Characteristics of IgA anti-HIV antibodies in plasma from patients with HIV infection

The concentration of total IgA and the specificity and molecular size of IgA anti-human immunodeficiency virus (HIV) type-1 antibodies in plasma obtained from individuals at different stages of HIV infection were analyzed. The concentration of total IgA in the plasma was not decreased even in the late stage of HIV infection, in contrast with those of total IgG and IgM. The IgA anti-HIV antibodies differed to the IgG anti-HIV antibodies in their specificity as determined by Western blotting. The IgA antibodies mainly bind to Env glycoproteins. The IgA anti-HIV antibodies in plasma were detected between IgG and IgM by gel filtration, suggesting the presence of polymeric IgA anti-HIV antibodies. These results indicate that the production of non-specific IgA in plasma is enhanced by unknown mechanisms in every stages of HIV infection, and suggest that IgA anti-HIV antibodies in plasma which are possibly polymeric and have unique specificity may play an important role in HIV infection.     

Conductive Papers Containing Metallized Polyester Fibers for Electromagnetic Interference Shielding

Conductive papers were developed for preventing or reducing electromagnetic interference (EMI), and their shielding efficiency was evaluated. This type of conductive paper consists of wood pulp, synthetic pulp and metallized polyester fibers (0.5–2.0 mm long and 14 m in diameter) whose surfaces are coated with nickel alone (Ni-PET) or copper and nickel double layers (Ni-Cu-PET) by electroless plating. In this report, the effect of the characteristics of these metallized fibers, such as their conductivity, geometry and the concentration of fibers in paper, which lead to high efficiency for shielding effectiveness is discussed. For instance, one of the conductive papers (80 g/m2) which was prepared by mixing 40% Ni-Cu-PET and 60% synthetic polyethylene pulp showed over 40 dB shielding effectiveness between 10 MHz and 1 GHz.     

Graft copolymerization of styrene onto cellulose acetate p-nitrobenzoate by chain transfer reaction

Styrene was grafted onto cellulose acetate p-nitrobenzoate (CANB) by chain transfer reaction of growing polymer radicals to the pendant nitro groups of CANB. A copolymer with a branch for every 17.2 nitro groups was obtained. This result indicates that the pendant aromatic nitro group is more effective in obtaining a graft copolymer by radical mechanism than pendant double bond on the trunk polymer previously reported, where graft copolymers with a branch for several hundred of double bonds are produced.     

New pixel driving circuit using self‐discharging compensation method for high‐resolution OLED micro displays on a silicon backplane

A new 4T2C pixel circuit formed on a silicon substrate is proposed to realize a high‐resolution 7.8‐μm pixel pitch AMOLED microdisplay. In order to achieve high luminance uniformity, the pixel circuit compensates its Vth variation of the MOSFET for the driving transistor internally by using self‐discharging method. Also presented are 0.5‐in Quad‐VGA and 1.25‐in wide Quad‐XGA microdisplays with the proposed pixel circuit.     

Superconductivity of Zr-Nb-Si amorphous alloys

Superconducting amorphous alloys with high strength and good ductility have been found in rapidly quenched alloys of the Zr-Nb-Si system. These alloys were produced in a continuous ribbon form of 1 to 2 mm width and 0.02 to 0.03 mm thickness using a modified single roller quenching apparatus. The amorphous alloys were formed over the whole composition range between zirconium and niobium, but the silicon content was limited to the relatively narrow range between about 12 and 24 at%. All the amorphous alloys showed a superconducting transition whose temperature, T _c, increased from 2.31 to 4.20 K with increasing niobium content or with decreasing silicon content. The upper critical magnetic field, H _c2, and the critical current density, J _c, for Zr₁₅Nb₇₀Si₁₅ alloy were of the order of 4.5 Tesla(T) and 5.5×10⁶ A m^–2 at 1.5 K in the absence of applied field. The upper critical field gradient at T _c, , and the electrical resistivity at 4.2 K, _n, decreased from 2.89 to 2.10 T K^–1 and from 2.70 to 1.80m, respectively, with the amount of niobium. The Debye temperature, _D, the electron-phonon coupling constant, , and the bare density of electronic states at the Fermi level, N(E _f ) were calculated from the experimentally measured values of _n, , Young's modulus and density by using the strong-coupling theories. From the comparison of T _c with their calculated parameters, it was found that is the most dominant parameter for T _c. The GL parameter, , and the GL coherence length, _GL(0), were estimated to be 70 to 100 and about 7.6 nm, respectively, from the experimental values of and _n by using the GLAG theory and hence it is concluded that the present amorphous alloys are an extremely dirty type-II superconductor having a very weak flux pinning force.     

Thermodynamic study and intrinsic type II superconductivity in the A-15 compound V3Si

The specific heat of a single crystal of the A-15-type compound V₃Si in the normal, mixed, and superconducting states has been measured from 4 to 30 K in magnetic fields up to 50 kOe. The analysis has been performed in a self-consistent way based on the second-order phase transition from the normal to the superconducting state. The thermodynamic critical field and then various physical parameters characterizing the superconducting and normal states are almost consistently derived from the thermodynamics and the microscopic BCS-GLAG theory. It is confirmed that V₃Si is an intrinsic type II superconductor with a high intrinsic GL parameter ₀.This work was partially supported by a Grant in Aid for Scientific Research (B) from the Ministry of Education.     

Development of dual-probe atomic force microscopy system using optical beam deflection sensors with obliquely incident laser beams

We developed a dual-probe (DP) atomic force microscopy (AFM) system that has two independently controlled probes. The deflection of each cantilever is measured by the optical beam deflection (OBD) method. In order to keep a large space over the two probes for an objective lens with a large numerical aperture, we employed the OBD sensors with obliquely incident laser beams. In this paper, we describe the details of our developed DP-AFM system, including analysis of the sensitivity of the OBD sensor for detection of the cantilever deflection. We also describe a method to eliminate the crosstalk caused by the vertical translation of the cantilever. In addition, we demonstrate simultaneous topographic imaging of a test sample by the two probes and surface potential measurement on an α-sexithiophene (α-6T) thin film by one probe while electrical charges were injected by the other probe.