Nagoya Institute of Technology

About: Nagoya Institute of Technology is a education organization based out in Nagoya, Japan. It is known for research contribution in the topics: Thin film & Catalysis. The organization has 10766 authors who have published 19140 publications receiving 255696 citations. The organization is also known as: Nagoya Kōgyō Daigaku & Nitech.

An On-Body Channel Model for UWB Body Area Communications for Various Postures

Abstract: On-body area ultrawideband (UWB) communication is of high importance for promising new biomedical applications. However, there are currently few measurements or models describing on-body area propagation channels which put an emphasis on various body postures. Using the frequency-dependent finite-difference time domain (FDTD) method and a realistic human body model, we simulate various body postures for modeling on-body channels. Based on the FDTD numerical results, we derive an on-body propagation model and determine the model parameters for some representative transmission links on the human body. A good match is obtained between the data derived from FDTD and the statistically implemented models in terms of key communication metrics. In addition, for the chest-to-right-waist transmission link, an experiment is performed in order to verify the results from the FDTD method, and it is found that the model parameters agree well between the two approaches.

Enantioselective Synthesis of (R)‐Convolutamydine A with New N‐Heteroarylsulfonylprolinamides

Abstract: Convolutamydine A is an alkaloid that was isolated from the Floridian marine bryozoan Amathia convoluta by Kamano and co-workers in 1995. (R)-Convolutamydine A exhibits a potent inhibitory activity towards the differentiation of HL-60 human promyelocytic leukaemia cells at 0.1– 25 mgmL . In 2006, Gargen and Tomasini0s group reported the first enantioselective synthesis of natural (R)-convolutACHTUNGTRENNUNGamydine A through a direct aldol reaction of 4,6-dibromoACHTUNGTRENNUNGisatin with acetone by using 10 mol% of a peptidic catalyst derived from d-proline and l-b-homophenylgricine. Very recently, Xiao and co-workers reported the same reaction with 20 mol% of a chiral bisamide, prepared from a chiral diamine and l-proline, as an organocatalyst to give 60% enantionmeric excess (ee) of the unnatural (S)-convolutamydine A. Malkov and co-workers reported the synthesis of (R)-convolutamydine A with high enantiopurity (up to 94% ee) by using 20 mol% of d-leucinol prepared from unnatural d-leucine; however, it takes a long time (RT, 36 h) for the reaction to reach completion. Unsolved problems include high catalyst loading and the use of organocatalysts derived from unnatural a-amino acids to prepare (R)-convolutamydine A. On the other hand, organocatalytic aldol reactions with ketones as acceptors generally need a high catalyst loading (at least 5–10 mol%) of organocatalyst, whereas enantioselective aldol reactions with aldehydes have been achieved with low catalyst loading of organocatalysts. Recently, we and others have reported enantioselective reactions that use 2-point coordinative heteroarylsulfonyl groups, which can control the transition state (TS) or intermediates by chelation with chiral Lewis acids or organocatalysts. To overcome the difficulty of the enantioselective reaction between 4,6-dibromoisatin as the ketone acceptor and acetone, we designed novel natural N-heteroarylsulfonylprolinamide organocatalysts, which would enable the TS to be controlled by intramolecular hydrogen bonding between the sulfonimide NH proton and the heteroatom of the heteroaryl group (Scheme 1). Herein, we report the highly efficient synthesis of (R)-convolutamydine A and its derivatives by using a catalytic amount of novel N-heteroarylsulfonylprolinamide organocatalyst.