The synthesis of nonsymmetrical polyamines (PAs) has, up to now, been problematic due to lengthy synthetic procedures, lack of regioselectivity, and very poor atom economy. An innovative synthetic protocol for nonsymmetrical PAs using a modified Ugi reaction ( N-split Ugi) which simplifies the synthesis of these tricky compounds is described. We believe that this new synthesis may open the door...

This paper presents the nonlinear analysis of stability and dynamic rotational accuracy an unbalanced rotor supported by aerostatic journal bearings. A finite element method is utilized with Runge-Kutta fourth order to solve transient Reynolds equation dynamics equations simultaneously for response rotor. The behavior center analyzed under different masses. It shown that responses strongly depe...

286 Ann Dermatol Received April 1, 2013, Revised May 28, 2013, Accepted for publication May 28, 2013 Corresponding author: Soyun Cho, Department of Dermatology, SMG-SNU Boramae Medical Center, 20 Boramae-ro 5-gil, Dongjakgu, Seoul 156-849, Korea. Tel: 82-2-870-2381, Fax: 82-2-870-3866, E-mail: [email protected] This is an Open Access article distributed under the terms of the Creative Commons Att...

ABSTRACT Polyvinylpolypyrrolidone supported chlorosulfonic acid ([PVPP-SO3H]+Cl-) was synthesized and evaluated as a recoverable catalyst for the one-pot synthesis of hexahydroquinolines by reaction of arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione) or 1,3-cyclohexanedione, ethylacetoacetate and ammonium acetate in high to excellent yield in ethanol at 70 °C. The [PVPP-SO3H]+Cl- cat...

This paper seeks to analyze a CSCW (Computer Supported Cooperative Work) approach for supporting Communities of Practice; mainly we focus on discussing how awareness plays a central role for supporting knowledge sharing in a knowledge intensive community.

"To what extent can people be taught to engage in Computer Supported Cooperative Work (CSCW)?" is a question which has rarely been discussed at meetings of CSCW researchers. The present study suggests that qualitative research can contribute to the development of a curriculum for preparing nurses to work with patients who live at a distance from themselves. Building on the ethnographic research...