Optically active single-walled carbon nanotubes

The optical, electrical and mechanical properties of single-walled carbon nanotubes (SWNTs) are largely determined by their structures, and bulk availability of uniform materials is vital for extending their technological applications1. Since they were first prepared2, 3, much effort has been directed toward selective synthesis and separation of SWNTs with specific structures. As-prepared samples of chiral SWNTs contain equal amounts of left- and right-handed helical structures4, but little attention has been paid to the separation of these non-superimposable mirror image forms, known as optical isomers. Here, we show that optically active SWNT samples can be obtained by preferentially extracting either right- or left-handed SWNTs from a commercial sample. Chiral ‘gable-type’ diporphyrin molecules bind with different affinities to the left- and right-handed helical nanotube isomers to form complexes with unequal stabilities that can be readily separated. Significantly, the diporphyrins can be liberated from the complexes afterwards, to provide optically enriched SWNTs

Synthesis of migrastatin analogues as inhibitors of tumour cell migration: exploring structural change in and on the macrocyclic ring

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Migrastatin and isomigrastatin analogues have been synthesised in order to contribute to structure-activity studies on tumour cell migration inhibitors. These include macrocycles varying in ring size, functionality and alkene stereochemistry, as well as glucuronides. The synthesis work included application of the Saegusa-Ito reaction for regio- and stereoselective unsaturated macroketone formation, diastereoselective Brown allylation to generate 9-methylmigrastatin analogues and chelation-induced anomerisation to vary glucuronide configuration. Compounds were tested in vitro against both breast and pancreatic cancer cell lines and inhibition of tumour cell migration was observed in both wound-healing (scratch) and Boyden chamber assays. One unsaturated macroketone showed low affinity for a range of secondary drug targets, indicating it is at low risk of displaying adverse side effects.This publication has emanated from research supported in part by a research grant from Science Foundation Ireland (SFI) and is co‐funded under the European Regional Development Fund under Grant Number 14/SP/2710. The research leading to these results has also received funding in part from the People Programme (Marie Curie Actions) of the European Union′s Seventh Framework Programme FP7/2007‐2013/ under REA grant agreement No. PIEF‐GA‐2011‐299042 and the Poland National Science Council.Published versio

Mechanical Responses and Physical Factors of the Fingertip Pulp

The images of the mechanical responses were analysed when the fingertip was pressed against a plateau plate, and the influence of the contact angle on the loading pressure and the mechanical responses was investigated. As a result, as the contact angle was smaller, the change ratios due to the loading pressure were significantly larger in the contact length, the contact width and the distortion of lateral-view area. These parameters were thought to be useful in clinical medicine as indices for the degrees of mechanical responses of the fingertip. The length of the central axis and the maximum width of the fingertip were inappropriate as the parameters to represent the mechanical responses of the fingertip. The maximum width of the fingertip scarcely changed. This does not reflect the compressibility of the fingertip, and the fingertip as a whole extended along the central axis and in the vertical direction, and the change was not reflected in the maximum width

A potential glucuronate glycosyl donor with 2-O-acyl-6,3-lactone structure: efficient synthesis of glycosaminoglycan disaccharides

Development of β-selective glucuronylation reaction using phenyl 2,4-di-O-acetyl-1-thio-β-D-glucopyranosidurono-6,3-lactone was described. Glycosylations of this glycosyl donor with hexosamine derivatives proceeded with excellent yield and β-stereoselectivity to afford glycosaminoglycan-type disaccharides

Motion Analysis of Thumb in Cellular Phone Use

The thumb motion of 10 normal subjects during cellular phone use was measured using a reflective marker detection system to compare the maximum, minimum and range of flexion angles of the interphalangeal (IP), metacarpophalangeal (MP) and carpometacarpal (CM) joints. Two micro-reflective markers 3 mm in diameter were each placed on the dorsal surface of the distal phalanx, basal phalanx and metacarpal bone of the thumb. Three markers were placed on the dorsal hand in order to define the dorsal hand plane. Each subject pushed the 12 keys of a folding cellular phone with an 85-mm-long and 40-mm-wide keypad, sequentially from ‘1’ to ‘#’, and the pushing motion was recorded by six infrared video cameras for 12 seconds, using the VICON 612 system. The mean maximum flexion angle of the MP joint was significantly (p < .05) larger than the CM joint, and the mean minimum flexion angle of the CM joint was significantly (p < .01) smaller than the IP and MP joints. The mean range of motion of the IP joint was significantly (p < .05) larger than the MP and the CM joints. In a comparison of different key-pushing motions, only the CM joint was significantly (p < .05) larger in its range of motion. In conclusion, thumb motion on pushing the keys of the cellular phone was produced mainly by the MP and the CM joints. In addition, the ability to reach keys in different areas of the cellular phone keypad is regulated by changing the flexion angle of the CM joint

GaN-based FETs for microwave high-power applications

The present status of GaN-based FETs has been described with a focus on microwave high-power performance. Our latest developments of the devices are presented, and the device and amplifier performance is reported. This includes the demonstration of a 230-W CW output power at 2 GHz, a 156-W pulsed output power at 4 GHz, and a 5.8-W CW output power at 30 GHz. The results confirmed excellent potential of the GaN-based FETs especially for high-voltage, high-power applications at microwave and millimeter-wave frequencies