Effect of barbituric acid on the self-polymerization reaction of bismaleimides

Barbituric acid (BTA) was used as an initiator for the homopolymerization of bismaleimide (BMI). The reaction was controlled by the amount of barbituric acid and ended up with solvent-soluble oligomers. The effects of varying the amounts of BTA, as well as the reaction time, on BMI's self-polymerization reaction were investigated. The thus-formed oligomers were characterized by gel permeation chromatography (GPC), infrared spectra (IR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The degree of reaction increased proportionally to the concentration of BTA or the length of the reaction time. Thus, solvent-soluble BMI oligomer can be controlled and obtained.     

Transverse Shear Effect on Flutter of Composite Panels

The effect of transverse shear deformation on the supersonic flutter of composite panels has been investigated using the finite element method. First‐order shear‐deformation laminated‐plate theory and quasi‐steady aerodynamic theory are employed for the analysis. The total displacement of the plate is expressed as the sum of the displacement due to bending and the displacement due to shear deformation. Thus, the aerodynamic pressure induced by the plate motion is also the sum of the pressure induced by bending deformation and the pressure induced by shear deformation. Numerical results show that the transverse shear deformation may have a significant effect on the flutter boundary if aerodynamic damping were small or neglected in the determination of flutter boundary.     

Membrane association and RNA binding of recombinant hepatitis A virus protein 2C

The direct function of hepatitis A virus (HAV) protein 2C, a putative NTPase, is not known, yet genetic evidence obtained from chimeric viruses carrying the 2C genomic region of different HAV variants indicates that it plays a pivotal role in viral replication. In a first assessment of its potential function(s), membrane and RNA binding properties of HAV 2C were studied after expressing the protein in various recombinant systems. In contrast to poliovirus 2C, expression of HAV 2C was inhibitory to the growth and protein synthesis of bacteria. Deletion of the N-terminal amphipathic helix of 2C abrogated this effect and the ability of 2C to associate with eukaryotic membranes. Both, purified 2C and the N-terminally truncated protein were shown to bind RNA in vitro. Our data taken together suggest that HAV 2C is a multifunctional protein.     

Prolonged fasting in pediatric outpatients does not cause hypoglycemia

The long-term results after the manipulation and strapping in flexion of selected extension supracondylar fractures of the humerus were evaluated in 43 children. Reduced fractures that were stable when immobilized in approximately 110 degrees of flexion, without producing circulatory obstruction, were treated in this manner. After a minimum review of 4 years, 95 per cent of the children had an excellent or good range of elbow motion and 88 per cent had excellent or good elbow alignment. No child had Volkmann's ischaemic contracture. Five children had cubitus varus which was due to malunion in three, but was unrelated to the treatment of the supracondylar fracture in two children. If these two latter children were excluded then excellent or good alignment was observed in all children who had a Baumann (humerocapitellar) angle of 80 degrees or less at the time of reduction and 84 degrees or less 10 days after the fracture. We concluded that manipulation and strapping in flexion was suitable for approximately 60 per cent of children with isolated displaced supracondylar fractures of the humerus.     

Low-threshold, high-power, 1.3-μm wavelength, InGaAsP-InPetched-facet folded-cavity surface-emitting lasers

A 1.3-μm wavelength, InGaAsP-InP folded-cavity, surface-emitting laser with CH₄-H₂ reactive ion-etched vertical and 45° angled facets was demonstrated for the first time. Continuous-wave threshold currents of 32 mA have been achieved, with >15 mW CW power for the surface-emitted light. These surface-emitting lasers with two dry-etched facets are suitable for wafer-level testing and for monolithic integration with other InP-based photonic devices