Insect prothoracicotropic hormone: a new member of the vertebrate growth factor superfamily

Prothoracicotropic hormone (PTTH) is a brain neurosecretory protein that controls insect development. PTTH of the silkmoth Bombyx mori is a homodimeric protein, the subunit of which consists of 109 amino acids. Clear-cut sequence similarity to any other proteins has not been observed. By disulfide-bond pattern analysis and modeling of the PTTH structure based on the known three-dimensional (3D) structures of growth factor family with cystine-knot motif, we propose that the PTTH protomer adopts the fold unique to the structural superfamily of the growth factors, beta-nerve growth factor (beta-NGF), transforming growth factor-beta 2 (TGF-beta 2), and platelet-derived growth factor-BB (PDGF-BB). The insect neurohormone PTTH appears to be a member of the growth factor superfamily, sharing a common ancestral gene with the three vertebrate growth factors, beta-NGF, TGF-beta 2 and PDGF-BB.     

Preparation of C60 Thin Films and Cs-Rb Doping

The effect of preparation conditions onto the crystallinity of C₆₀ thin films were studied by using two different vapor deposition methods. Rb and Cs were found to be doped in C₆₀ thin films by the resistance measurement during the course of the doping experiment. The Rb/Cs-doped film showed a superconducting transition at Tc(onset)=24±3K and Tc(zero)=8K.     

Measurement of Elastic Moduli from the Impact Sound of Engineering Ceramics and Composites at Elevated Temperatures

A simple instrumentation system is developed for determining the elastic moduli of engineering ceramics and their composites from the sound produced by the impact of a sphere on a specimen which is suspended by thin wires or ceramic threads in a furnace. The natural frequencies of the flexural and torsional vibration modes are measured from the impact noise by using a fast Fourier transform analyzer. Elastic moduli are then computed from those frequencies by using Timoshenko's beam theory and also Saint-Venant's torsion theory. The validity of the measurementmethod is demonstrated by room-temperature tests on ceramic and metallic specimens of known elastic moduli. SiAION and Al-Al₂O₃ composites are tested at elevated temperatures up to 900°C. It is shown that the Young's and shear moduli of the materials tested decrease with an increase in temperature, while Poisson's ratio remains almost constant.     

Reduction of n-C5H11N3 Catalyzed by [Mo2Fe6S8(OMe)3(SC6H4-p-n-C8H17)6]3– in an Aqueous Micellar Solution

Reduction of n-C₅H₁₁N₃ by Na₂S₂O₄ was performed in the presence of (n-Bu₄N)₃ [Mo₂Fe₆S₈(OMe)₃(SC₆H4-p-n-C₈H₁₇)₆] ((n-Bu₄N)₃ [Mo-Fe]) as a catalyst in aqueous Triton X-100 micellar solutions. The rate of the reduction is enhanced efficiently by the addition of methyl viologen (MV²⁺). The methyl viologen radical cation (MV⁺) produced by the reaction of MV²⁺ with Na₂S₂O₄ undergoes a disproportionation reaction to afford MV²⁺ and MV° in the micellar solution. The resultant MV° formed in the micelle transfers two electrons to [Mo-Fe]³⁻ effectively to give [Mo-Fe]⁵⁻, which reduces n-C₅H₁₁N₃ with two electrons to produce n-C₅H₁₁NH₂ and N₂.     

Synthesis of poly(N,N-dimethylaminopropylacryl amide-g-acrylic acid) and crosslinking of its trunk sequence

Summary The graft copolymers composed of weak base and weak acid sequences, i.e., poly(N,N-dimethylaminopropylacryl amide-g-acrylic acid) (poly(DAPA-AA)) including 51–87 mol% of acrylic acid (AA) were prepared by redox system using cerium(IV) ammonium sulfate as initiator. Microphase separation of two sequences was observed in basic casting solvent. The crosslinking of DAPA sequence, which had shown spheric morphology, was carried out by mean of gas-solid phase quaternization reaction with 1,4-dibromobutane. The reaction product was soluble in NaOH aq. or HCl aq. until 4.3% quaternization of DAPA unit without remarkable increase of intrinsic viscosity. And they were found to be very different in solubility from the raw graft copolymer.     

Prospective Validation of High-Shear Wet Granulation Process by Wet Granule Sieving Method. II. Utility of Wet Granule Sieving Method

The general utility of a method for determination of high-shear wet granulation end point by monitoring the wet granule particle size distribution was evaluated. Wet granulation was conducted in a 25-liter high-shear mixer using four model drugs with different solubilities and particle sizes (ethenzamide, unmilled and milled acetaminophen, and antipyrine). For each drug formulation, its wet granule particle size fraction and target range for granulation end point determination were selected based on the tablet characteristics that are known to be influenced by the wet granulation process. Granules manufactured under different conditions (i.e., different main and chopper blade speeds and binder supplying rate) but manufactured to the same granulation end point determined by the selected fraction and range showed very similar granule characteristics and subsequently very similar tabler characteristics. From the fact that there was a good correlation between the wet and dry-sized granule particle size distributions even if the drying method was changed from fluid-bed drying to vacuum drying, the general application of the end point determining method was verified. Further, the method was shown to be sensitive to the critical granulation parameters for granulation progression and to be very capable of determining the granulation extent. Thus, it was suggested that the method is applicable to various drugs and formulations for determination of wet granulation end point.     

Measurement of contact resistance distribution using a 4k-contactsarray

A new test structure suitable for measuring a contact resistance distribution has been developed. It includes the following two components: a 256 row, 16 column (= 4096) four-terminal cross-contact array; and peripheral circuits, which consist of an eight-stage CMOS binary counter and 256-bit CMOS decoders. It was found that contact resistance can be fitted by a Gaussian distribution for more than three standard deviations of the mean value. The relationship between the contact size and the standard deviation of the contact resistance has been discussed for two types of contacts: Al/TiN/TiSi₂-n⁺Si, and WSi₂/poly-n⁺Si. This test structure can simultaneously measure the series resistance of a two-terminal contact chain and the individual contact resistance. By comparing the results of the two measurement modes, it was found that there are three kinds of contact resistance distribution in the chips which have high series resistance of the two-terminal contact chain     

Ice formation process by cooling water–oil emulsion with stirring in a vessel

An emulsion, which was a mixture of silanol-aqueous solution and silicone oil, was investigated as a heat storage material for a dynamic type ice storage system. The emulsion was poured into a vessel, which was immersed into a constant temperature bath at a low temperature, and frozen with stirring. Using stainless steel vessels coated with PFA resin and PTFE vessels with different thickness, the experiments were carried out under various conditions of temperature. Measuring the temperature history in the vessel, overall heat transfer coefficients before the start of freezing and during the ice formation were obtained. The effects of the material of the cooling surface and the thermal resistance of the wall on the ice formation process were clarified. If the heat flux of the wall was less than a critical value, slurry ice was formed without adhesion to the cooling surface. The results obtained under the same condition of the thermal resistance proved that it was effective against ice adhesion to coat PFA resin inside the vessel. It was found by the experiments in which the PTFE vessels were used that the critical value of the heat flux was nearly constant regardless of the thermal resistance.