Mechanochemical block copolymerization in heterogeneous systems of the solid poly(vinyl chloride) with styrene by ultrasonic irradiation

Summary Mechanochemical block copolymerization in heterogeneous systems of the solid poly(vinyl chloride)-styrene-sodium dodecyl sulfate aqueous solutions has been studied by ultrasonic irradiation at 65 °C. The block copolymerization of styrene was initiated by free radicals produced from the poly(vinyl chloride) particles by ultrasonic waves. The initial rate of the block copolymerization Rp was given by Rp α [Styrene] [Sodium dodecyl sulfate]^1/2. Both copolymer and homopolymer were obtained. For example, when 2.506 g of the poly(vinyl chloride) particles, 24.23 g of styrene, and 54.00 g of sodium dodecyl sulfate aqueous solution (0.500 wt%) were added in the reaction system, the weight proportions of the block copolymer and polystyrene after 60 min were approximately 50 and 20%.     

Development of an Artificial Lipid-Based Membrane Sensor with High Selectivity and Sensitivity to the Bitterness of Drugs and with High Correlation with Sensory Score

This paper reports the development of membrane sensors based on an artificial lipid and plasticizers with high selectivity and sensitivity to drug bitterness by using bis(1-butylpentyl) adipate (BBPA), bis(2-ethylhexyl) sebacate (BEHS), phosphoric acid tris(2-ethylhexyl) ester (PTEH), and tributyl o-acetylcitrate (TBAC) as a plasticizer and phosphoric acid di-n-decyl ester (PADE) as an artificial lipid to optimize surface hydrophobicity of the sensors. In addition, a sensor with highly correlated bitterness sensory score was developed by blending BBPA and TBAC to detect the bitterness suppression effect of sucrose, and other bitter-masking materials. Therefore, this sensor can be used to evaluate the bitterness of various drug formulations with high accuracy. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Application of the environmental SEM in human dentin bleached with hydrogen peroxide in vitro.

The environmental SEM (E-SEM) can be used unfixed biological samples under a low vacuum and wet condition. In this study, the fractured dentin of unfixed human teeth was treated with a 30% hydrogen peroxide solution (H2O2) for the examination of tooth-bleaching prior to the E-SEM and a conventional SEM. The peritubular matrix (PM) always showed a few cracks along the long axis of a dentinal tubule, and the ends of fine fibrils rose to the smoothly changed surface of the intertubular matrix (IM). The E-SEM with non-fixation and the conventional SEM following fixation indicated that the hydrogen peroxide solution easily permeated the PM and dissolved the non-fibrillar substance including the cracks of the PM by the constriction. In the IM, the solution may partially dissolve the organic parts within mineralized fibrils as well as non-fibrillar substance between the fibrils, although these remnants might precipitate again there.     

Fast electro‐optical response at low temperature for metal nanoparticle embedded STN‐LCDs (Invited Paper)

Abstract— STN‐LCDs embedded with special metal nanoparticles of Ag/Pd are shown to be useful for a direct‐multiplexed dot‐matrix STN‐LCD with 320 × 240 pixels and show a fast response time by 3–5 times compared to those without nanoparticles. This phenomenon is shown to be attributed to the reduction of rotational viscosity by 70% at room temperature and by 30% at a low temperature (?20°C). The alteration of elastic constants by doping nanoparticles could be also essential.     

A novel surface plasmon resonance immunosensor for 2,4,6-trinitrotoluene (TNT) based on indirect competitive immunoreaction: a promising approach for on-site landmine detection

A surface plasmon resonance (SPR) immunosensor for the determination of 2,4,6-trinitrotoluene (TNT) has been developed based on the principle of indirect competitive immunoreaction. 2,4,6-trinitrophenol-bovine serum albumin (TNP-BSA) conjugate was immobilized onto a SPR gold chip by means of simple physical adsorption. Binding of anti-TNP antibody with TNP-BSA conjugate was detected based on an increase in resonance angle due to antigen-antibody interaction. Preincubation of anti-TNP antibody with TNT suppresses its interaction with immobilized TNP-BSA conjugate, which leads to a decrease in resonance angle shift. Following the dependence of the resonance angle shift, concentration of TNT was detected. Pepsin solution was used for the regeneration of the sensing surface. The response time for TNT measurement is about 22 min. The immunosensor showed excellent sensitivity to TNT in a wide concentration range from 60 ppt to 1000 ppb with good selectivity, stability, and reproducibility. The proposed system is promising for future application for the on-site detection of landmines.     

Surface plasmon resonance immunosensor using Au nanoparticle for detection of TNT

In order to develop the fully integrated portable surface plasmon resonance (SPR) system for detection of explosives, the amplification strategy of SPR signal was investigated. Indirect competitive inhibition method allowed the middle-sized SPR sensor to detect trinitrotoluene (TNT) at ppt level. However, this enhanced SPR signal was not high enough to detect TNT at ppt level by a miniaturized SPR sensor. Therefore, localized surface plasmon resonance (LSPR) effect using Au nanoparticle as further signal amplification approach was used. The amplification method of indirect competitive inhibition and LSPR were combined together for fabrication of the immunosurface using Au nanoparticle. TNT detectable range of this immunosurface was from 10 ppt (10 pg/ml) to 100 ppb (100 ng/ml), which was almost comparable to that without Au nanoparticle. The observed resonance angle change due to binding monoclonal TNT antibody (M-TNT Ab) with the immunosurface modified with Au nanoparticle was amplified to four times higher than that in absence of Au nanoparticle.     

SAFETY EXAMINATION OF SOME EDIBLE OR MEDICINAL PLANTS AND PLANT CONSTITUENTS, PART 3

The carcinogenicity of vicia, galanga, lathyrus and lycium, which are plants used as human food or in folk medicine, and of caffeic acid and prunasin, which are plant constituents, was examined in an inbred strain of ACI rats. Fresh plant materials were dried, milled and mixed with the rat basal diet in the ratio of 16% and 33% of the total. The plant constituents, caffeic acid and prunasin, were mixed with the basal diet in the ratio of 0.5% and 0.03%, respectively. These diets were administered to rats for periods ranging upward from 180 days. Carcinogenic activity was not observed with any of the plants or plant constituents.     

Multilayer polarization elements and their applications to polarimetric studies in vacuum ultraviolet and soft X-ray regions

Multilayer polarization elements and their applications to polarimetric studies in 20～400 eV region are mainly reviewed.General principle of selecting material combinations to get high linear polarizance multilayers of reflection type is given with practical examples,with periodic or non-periodic layer structures depending on the usage.Transmission type is introduced as linear polarizer and phase shifter.Their applications include polarization diagnosis of laboratory optical systems and synchrotron radiation beamlines of linear and circular polarization,magnetic rotation experiments such as Faraday rotation and magnetic Kerr rotation on magnetic films and multilayers,and ellipsometry to measure optical constants of thin films precisely.Polarization analysis of soft X-ray fluorescence using multilayer-coated grating is also mentioned.Finally this review is summarized with outlook of further developments.     

Strained single-crystal GOI (Ge on Insulator) arrays by rapid-melting growth from Si (1 1 1) micro-seeds

Liquid-phase epitaxial growth of Ge islands on insulator (GOI) using Ni-imprint-induced Si (1 1 1) micro-crystal seeds (∼1 μm?) is proposed. As a result, single-crystalline GOI (1 1 1) structures with large area (∼10 μm?) are realized. The transmission electron microscopy observations reveal no dislocation or stacking fault in the laterally grown regions. Moreover, the Raman measurements show that the tensile strain (∼0.2%) which enhances the carrier mobility is induced in the growth regions. This new method can be employed to realize the multi-functional SiGe large scale integrated circuits.