Implantable CMOS Biomedical Devices

The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented

Active methylene compounds in asymmetric organocatalytic synthesis of natural products and pharmaceutical scaffolds

International audienceLast decades have witnessed the golden rush of organocatalysis, which opened an effective and efficient way to high yielding, metal free, stereoselective strategies toward the synthesis of a plethora of natural products. The present review provides an overview of the current achievements of those organocatalytic methodologies in which active methylene compds. have been used as key intermediates. Ranging from covalent to non-covalent activation mode, from monofunctional to bifunctional catalysts, recent results suggest a variety of new powerful tools to accomplish the formal and total synthesis of both the simplest and the most complex natural compds. with facile procedures in high yields and excellent stereoselectivities. At the same time, it is clear how the organocatalytic approach might offer an outstanding and impressive answer to unsolved longstanding synthetic challenges. Finally the possible application to industrial protocols and to the prepn. of novel potential drugs has been highlighted

4D deformation modeling of cortical disease progression in Alzheimer's dementia

This work describes the development of a model of cerebral atrophic changes associated with the progression of Alzheimer's disease (AD). Linear registration, region-of-interest analysis, and voxel-based morphometry methods have all been employed to elucidate the changes observed at discrete intervals during a disease process. In addition to describing the nature of the changes, modeling disease-related changes via deformations can also provide information on temporal characteristics. In order to continuously model changes associated with AD, deformation maps from 21 patients were averaged across a novel z-score disease progression dimension based on Mini Mental State Examination (MMSE) scores. The resulting deformation maps are presented via three metrics: local volume loss (atrophy), volume (CSF) increase, and translation (interpreted as representing collapse of cortical structures). Inspection of the maps revealed significant perturbations in the deformation fields corresponding to the entorhinal cortex (EC) and hippocampus, orbitofrontal and parietal cortex, and regions surrounding the sulci and ventricular spaces, with earlier changes predominantly lateralized to the left hemisphere. These changes are consistent with results from post-mortem studies of AD. (C) 2001 Wiley-Liss, Inc