Multifocal Motor Neuropathy

Objective: Our objective was to do an epidemiologic survey of patients with multifocal motor neuropathy (MMN) in comparison with those with amyotrophic lateral sclerosis (ALS) in Japan. Methods: In this retrospective study, we examined 46 patients with MMN and 1,051 patients with ALS from major neuromuscular centers in Japan from 2005 to 2009. Diagnosis was based on the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) and the revised El Escorial criteria. The efficacy of intravenous immunoglobulin (IVIg) was also taken into consideration in the diagnosis of MMN. Results: The ratio of MMN to ALS patients (0-0.10) varied among the centers, but mostly converged to 0.05. The prevalence was estimated to be 0.29 MMN patients and 6.63 ALS patients per 100,000 population. Conclusions: The frequency of MMN patients was around 1 out of 20 ALS patients, and MMN was possibly underdiagnosed in some centers

Role of block copolymer surfactant on the pore formation in methylsilsesquioxane aerogel systems

Transparent and low-density methylsilsesquioxane (MSQ, CH3SiO1.5) aerogels can be obtained solely from methyltrimethoxysilane (MTMS) by a one-pot two-step process under the co-presence of surfactant. In the present study, we have systematically investigated the effects of the molecular structure of triblock copolymer-type nonionic surfactants PEO-b-PPO-b-PEO (PEO and PPO denote poly(ethylene oxide) and poly(propylene oxide) units, respectively) on the properties of the resultant MSQ aerogels. Macroscopic phase separation of hydrophobic MSQ networks from polar solvent occurs when no surfactant is employed, which results in macroporous opaque aerogels. In contrast, a co-presence of appropriate surfactant effectively suppresses the phase separation and yields transparent aerogels after supercritical drying. By employing various surfactants having different molecular weight and PO/EO ratio, the mechanism of suppression of phase separation or pore formation is discussed in detail. In situ1H NMR suggests that the PO units of surfactant interact with the hydrophobic MSQ network enriched with methyl groups and make the MSQ network hydrophilic by extending EO chains toward the aqueous solvent in the late phase of gelation, until which hydrogen bonding dominates between the Si-OH groups of polymerizing MSQ and the ether oxygens of the EO unit. Through the comprehensive understanding of the role of surfactant, the strategy for rational design of MSQ aerogels materials has become developable

Conformational Change and Orientation Fluctuations Prior to Crystallization of Crystalline Polysty-renes (FUNDAMENTAL MATERIAL PROPERTIES-Polymer Materials Science)

Aiming to clarify the cause of a spinodal decomposition (SD) type microphase separation occuring during the induction period of polymer crystallization, we have made quantitative investigations about the conformational changes using FT-IR spectroscopy as well as the orientation fluctuations of the polymer rigid segments using depolarized light scattering (DPLS) . It is confirmed for syndiotactic and isotactic polystyrenes (sPS and iPS) that during the induction period, the polymer chains first transform partially from the amorpous to the crystalline conformation, involving in the increase of length of the rigid segments, which makes the system unstable to induce the orientation fluctuations of the SD type. Thus, the intensity of orientation fluctuations evloved exponentially with annealing time

A New Discovery of Microphase Separation Initiating In the Induction Period of Polymer Crystallization : characteristic wavelengths at high temperatures (FUNDAMENTAL MATERIAL PROPERTIES-Polymer Materials Science)

On the basis of the previous new discovery that a spinodal decomposition type of microphase separation occurs during the induction period for glass crystallization when a polymer is crystallized at low temperatures just above the glass transition temperature, the effect of crystallization temperature on the characteristic wavelength has been studied using poly(ethylene terephthalate) (PET) because this is an important factor for spinodal structures determining the whole skelton of higher-order structure of crystalline polymers. For melt crystallization when PET is crystallized directly from the melt at high temperatures below the melting point, the characteristic wavelength is obtained to be a few micrometers which is two orders of magnitude larger than that for the glass crystallization. This may provide a possible elucidation for the large difference in size and density of spherulites between the glass and melt crystallization