Dyeing properties of cotton fibres treated with liquid ammonia

Both scoured and sodium hydroxide mercerised cotton fibres have been treated with liquid ammonia atndash33.4°C using commercial operating equipment and then the ammonia removed at 130°C in a hot drum. The moisture regain and water absorbency of the fibres treated with liquid ammonia were increased compared with values on untreated fibres, whereas both these parameters on mercerised cotton fibres were decreased by subsequent liquid ammonia treatment. The fibres were dyed with CI Direct Red 2 and CI Direct Blue 1. Liquid ammonia treatment of the scoured cotton fibres increased the rate of dyeing, equilibrium dye adsorption, standard affinity, heat of dyeing and change of entropy, while the dyeing properties of mercerised cotton were adversely affected by subsequent liquid ammonia treatment.     

Amelioration of hyperglycemia and metabolic syndromes in type 2 diabetic KKA(y) mice by poly(gamma-glutamic acid)oxovanadium(IV) complex

Recently, we found that poly(gamma-glutamic acid)oxovanadium(IV) complex (VO(gamma-pga)) exhibits a potent antidiabetic activity in streptozotocin (STZ)-induced type 1 diabetic mice. This result prompted us to examine its ability to treat the type 2 diabetic model KKA(y) mice with insulin resistance. We studied the in vivo antidiabetic activity of VO(gamma-pga), compared with that of vanadium(IV) oxide sulfate (VS) as control. Both compounds were orally administered at doses of 5-10 mg (0.1-0.2 mmol) V kg(-1) body mass to the KKA(y) mice for 30 days. VO(gamma-pga) normalized the hyperglycemia within 21 days, whereas VS lowered the blood glucose concentration only by a small degree. In addition, the glucose intolerance, HbA(1c) level, hyperinsulinemia, hypercholesterolemia, and hyperleptinemia were significantly improved in VO(gamma-pga)-treated KKA(y) mice compared with those treated with VS. Based on these observations, VO(gamma-pga) is proposed to be the first orally active oxovanadium(IV)-polymer complex for the efficacious treatment of not only type 2 diabetes but also metabolic syndrome in animals.     

Barrier mechanism of Pt/Ta and Pt/Ti layers for SrTiO3 thin film capacitors on Si

Abstract

The barrier effect of Pt/Ta and Pt/Ti has been investigated, when used as bottom electrodes for SrTiO₃ thin film capacitors on Si. The Pt/Ta/Si stacks were more stable than the Pt/Ti/Si, both in vacuum and in oxygen annealing. Though the Pt/Ta bilayer was suitable for the SrTiO₃ deposition at 400[ddot]C, its resistivity became slightly higher after the deposition at 600[ddot]C, due to Ta layer oxidation during the SrTiO₃ deposition. This would result in a contact resistance problem for high density dynamic random access memory application.     

Ultrasensitive Molecular Beacon Designed with Totally Serinol Nucleic Acid (SNA) for Monitoring mRNA in Cells

An artificial nucleic acid based on acyclic serinol building blocks and termed “serinol nucleic acid” (SNA) was used to construct a fluorescent probe for RNA visualization in cells. The molecular beacon (MB) composed of only SNA with a fluorophore at one terminus and a quencher at the other was resistant to enzymatic digestion, due to its unnatural acyclic scaffold. The SNA‐MB could detect its complementary RNA with extremely high sensitivity; the signal‐to‐background (S/B) ratio was as high as 930 when perylene and anthraquinone were used as the fluorophore and quencher pair. A high S/B ratio was also achieved with SNA‐MB tethering the conventional Cy3 fluorophore, and this probe enabled selective visualization of target mRNA in fixed cells. Thus, SNA‐MB has potential for use as a biological tool capable of visualizing RNA in living cells.     

Enhancement of Stability and Activity of siRNA by Terminal Substitution with Serinol Nucleic Acid (SNA)

RNA interference (RNAi ), sequence‐specific gene silencing triggered by double‐stranded, small interfering RNA (siRNA), has become a facile and effective tool for biological research and holds potential for therapeutic applications. However, the application of siRNA is hindered by susceptibility to nucleases and off‐target effects. In this study, we introduced artificial nucleotides, serinol nucleic acid (SNA), with an acyclic scaffold, at the termini of siRNA strands. Our aim was appropriately to accommodate the antisense strand in an RNA‐induced silencing complex (RISC) by inhibiting sense‐strand incorporation and thus improve resistance to nuclease‐mediated degradation. Substitution of SNA into siRNA at both termini of the sense strand and at the 3′ terminus of the antisense strand improved antisense strand selectivity remarkably in the formation of RISC, RNAi activity, and nuclease resistance.     

Inkjet Aerosol Generator as Monodisperse Particle Number Standard

The AIST-inkjet aerosol generator (IAG) can generate highly monodisperse solid or liquid aerosol particles in the particle diameter range from 0.3 to 20 μm at precisely known particle generation rates. The device has been developed for evaluating the counting efficiencies of optical and condensation particle counters. Particle generation efficiency of the IAG is defined as the number of aerosol particles generated by one voltage pulse sent to an inkjet head. The 95% confidence interval of the efficiency were 0.998 ± 0.006 within the 0.4 to 10 μm particle diameter range. The efficiencies remained close to unity when the droplet generation rates were within 20–500 s^?1 and 100–900 s^?1 using ultrapure-water and isopropyl alcohol (IPA) as the solvent of the inkjet solution, respectively. The operating aerosol flowrate range of the IAG is currently 0.5 and 1.0 L/min. The coefficients of variations (C.V.) of the size distributions were 2 to 3% indicating the generated particles were highly monodisperse. The generated particle sizes were defined as the volume equivalent diameter, D_ve. The uncertainty analysis on the factors affecting D_ve indicated that 95% confidence interval of the D_ve is expected to be ±5%. The uncertainty of D_ve was entirely caused by the uncertainty of the average mass of a droplet. The reproducibility of particle sizes within 0.5 to 10 μm was evaluated using an aerodynamic particle sizer. The C.V. of the measured particle sizes were less than 6% and 4% when NaCl particles and ionic liquid droplets were generated, respectively.

Copyright 2014 American Association for Aerosol Research     

Nucleation of Ethylene Glycol Vapor and Growth of Sub-10-nm Particles in Nanoparticle Size Magnifier

We investigated the rates of heterogeneous and homogeneous nucleation of ethylene glycol vapor onto sub-10-nm particles in a newly developed condensation device called nanoparticle size magnifier (NanoPSM). The saturation ratio in the NanoPSM is precisely controlled by vapor-feeding system and mixing section, which are designed based on an earlier particle size magnifier (PSM) developed by Okuyama et al. (1984). Size-classified NaCl nanoparticles smaller than 10 nm in mobility diameter are used as heterogeneous nuclei for the condensation of ethylene glycol vapor. The activation efficiency and growth rate of the activated nuclei are determined by a pulse height analysis using an optical particle counter (OPC). A computer fluid dynamics (CFD) simulation is employed to calculate the profiles of the gas velocity, temperature, vapor concentration, and resulting supersaturation in the NanoPSM. Annular high-supersaturation region is generated around the mixing boundary between cold aerosol and hot vapor. The experimental activation efficiency is 50% for 4.5-nm and 0.8% for 2 nm NaCl particles, through the subsequent growth of droplets to 2 μm in diameter. The experimental data are in fairly good agreement with the predicted activation efficiencies based on the classical Kelvin-Thomson theory when the local profiles of supersaturation are taken into account.