Eletrodos de SrTiO3 através de um novo método de precursores poliméricos.

Entrada padronizada: RIBEIRO, C

Cholinesterase Inhibitors: Drugs Looking for a Disease?

Maggini and colleagues examine the evidence on cholinesterase inhibitors for treating dementia. "What seemed a biologically plausible intervention," they say, "has not led to a proven, real improvement in patients' well-being.

Cholinesterase Inhibitors in Mild Cognitive Impairment: A Systematic Review of Randomised Trials

A systematic review of trials of cholinesterase inhibitors for preventing transition of mild cognitive impairment (MCI) to dementia, conducted by Roberto Raschetti and colleagues, found no difference between treatment and control groups and concluded that uncertainty regarding the definition of MCI casts doubts on the validity of such trials

Sudden Unexpected Deaths and Vaccinations during the First Two Years of Life in Italy: A Case Series Study

Background The signal of an association between vaccination in the second year of life with a hexavalent vaccine and sudden unexpected deaths (SUD) in the two days following vaccination was reported in Germany in 2003. A study to establish whether the immunisation with hexavalent vaccines increased the short term risk of SUD in infants was conducted in Italy. Methodology/Principal Findings The reference population comprises around 3 million infants vaccinated in Italy in the study period 1999–2004 (1.5 million received hexavalent vaccines). Events of SUD in infants aged 1–23 months were identified through the death certificates. Vaccination history was retrieved from immunisation registries. Association between immunisation and death was assessed adopting a case series design focusing on the risk periods 0–1, 0–7, and 0–14 days after immunisation. Among the 604 infants who died of SUD, 244 (40%) had received at least one vaccination. Four deaths occurred within two days from vaccination with the hexavalent vaccines (RR = 1.5; 95% CI 0.6 to 4.2). The RRs for the risk periods 0–7 and 0–14 were 2.0 (95% CI 1.2 to 3.5) and 1.5 (95% CI 0.9 to 2.4). The increased risk was limited to the first dose (RR = 2.2; 95% CI 1.1 to 4.4), whereas no increase was observed for the second and third doses combined. Conclusions The RRs of SUD for any vaccines and any risk periods, even when greater than 1, were almost an order of magnitude lower than the estimates in Germany. The limited increase in RRs found in Italy appears confined to the first dose and may be partly explained by a residual uncontrolled confounding effect of age

Deep reactive Ion Etching of Nb2O5/SiO2 multilayer structures for multispectral imaging devices

International audienceMultispectral or hyperspectral images allow acquiring new information that could not be acquired using colored images and, for example, Identifying chemical species on an observed scene using specific highly selective thin film filters. Those images are commonly used in numerous fields, e.g. in agriculture or homeland security and are of prime interest for imaging systems for onboard scientific applications (e.g. for Planetology). Those instruments are generally composed with a rotating filters wheel placed inside the imaging system. However, it is obvious that these rotating filters wheels are a bulky and heavy solution that make them non optimal solution for onboard applications. To overcome this problem, a solution is the fabrication of pixelated optical filters, similar to the Bayer filters used for color cameras but using specific thin film filters technologies (Fig. 1)

Glancing angle deposition for tuning electronic transport properties of Si thin films

International audienceIn this work, we developed a one-dimensional tight-binding model to study conductivity in solid-state superlattices. We investigated the localization properties of a tight-binding equation where the on-site potential is replaced by both quasiperiodic and periodicfunctions. We compared the metal–insulator transitions obtained using a periodic potential with an external electric field and an Aubry–André potential, which is the only known case of a 1D model with a mobility edge. For the case of a periodic potential, wefound the existence of a similar mobility edge if the applied electric field is small enough. In such a case, the extended and localized states in the superlattice can be controlled by an external source

Deep reactive Ion Etching of Nb2O5/SiO2 multilayer structures for multispectral imaging devices

International audienceMultispectral or hyperspectral images allow acquiring new information that could not be acquired using colored images and, for example, Identifying chemical species on an observed scene using specific highly selective thin film filters. Those images are commonly used in numerous fields, e.g. in agriculture or homeland security and are of prime interest for imaging systems for onboard scientific applications (e.g. for Planetology). Those instruments are generally composed with a rotating filters wheel placed inside the imaging system. However, it is obvious that these rotating filters wheels are a bulky and heavy solution that make them non optimal solution for onboard applications. To overcome this problem, a solution is the fabrication of pixelated optical filters, similar to the Bayer filters used for color cameras but using specific thin film filters technologies (Fig. 1)

Identification of an efficient adsorbent for ethanol sensing at room temperature using quartz crystal microbalance

International audienceZeolite coated quartz crystal microbalance (QCM) is proposed as an efficient sensor for the detection of ethanol at room temperature. In this work, three zeolites DaY, ZSM-5, and BEA were investigated in order to determine the most efficient adsorbent for ethanol sensing at room temperature. The sensing performances were found to be mostly influenced by the acid site density and the zeolite's pore size. The BEA coated QCM sensor exhibited the best performances with a high relative frequency shift from 9.0&nbsp;×&nbsp;10<sup&gt−7</sup&gt to 2&nbsp;×&nbsp;10<sup&gt−6</sup&gt for 10&nbsp;ppm of ethanol. Furthermore, this sensor exhibited fast response and recovery times which makes it a suitable material for the monitoring of ethanol in the air. In addition, the ethanol diffusion order was evaluated using Fickian diffusion law and was found to be the highest for the zeolite BEA. A sensing mechanism was also proposed for the adsorption and desorption of ethanol into zeolites based on unstable protonated dimers, water and diethyle ether resides for the energy-efficient ethanol sensor