Gravure printing for thin film ceramics manufacturing from nanoparticles

Printing technologies can offer high potential for the thin film deposition of functional materials. Among the printing techniques, the gravure is considered one of the most promising, although to date it is still little employed, especially for the inorganic functional materials. In this work, the study of the gravure printing process for the metal oxides thin film production on flexible polymer substrate is reported. For this purpose, zinc oxide (ZnO) was chosen due to its versatile properties and nanosize effects, which make it suitable for many high technology areas. The gravure printing was made using low viscosity inks of ZnO nanoparticles. The characteristics of the printed thin films were examined and discussed. Thanks to the understanding of the physics underlying the film forming during the printing process combined to the knowledge on such specific material, uniform, compact, very transparent and smooth films were obtained in different nanometric thicknesses. Moreover, the possibility of fabricating ceramic nanocomposite films directly through this printing technique is also presented. Thanks to its scientific approach, this work makes available to the world of ceramics an industrial versatile and low-cost production technique which can allow to study and develop high-quality thin film ceramics with technologically interesting properties as well as nanoparticles behavior and their treatments in order to develop and use their fascinating nanosize properties.     

Pressure-induced changes on the optical properties and microstructure of silica-gel matrices doped with rhodamine 6G

Sol–gel method and high-pressure technique were associated to produce silica compacts with low porosity and doped with rhodamine 6G (R6G). Acid catalyzed solutions of tetraethyl orthosilicate mixed with dye previously dissolved in ethanol were used for the synthesis of doped silica gel. The monolith obtained was comminuted and the powder was compacted between 3.0 and 7.7 GPa, at room temperature, using a toroidal-type high-pressure chamber. Excitation–emission fluorescence spectroscopy was used to investigate the optical properties of R6G embedded in the closed pores of the silica matrix. Measurements of surface areas and pore size distribution for the powders and compacts, using the N₂ isotherms were performed, showing a great reduction in surface area and porosity, after compaction. The dye entrapped in the compacted silica maintains its optical properties similar to that in ethanolic solutions, meaning that the dye is dispersed in a molecular level. Additionally, these samples are optically transparent, hard and resistant to dye leaching and to chemical attacks, being a promising material to be used in optical devices.     

Coffee with jelly or unbuttered toast: Commissions and omissions are dissociable aspects of everyday action impairment in Alzheimer's disease.

Relative to our understanding of the memory and language deficits associated with Alzheimer's disease (AD), little is known about problems with everyday action performance (i.e., meal preparation, grooming). The resource theory proposes that everyday action problems are best explained by a unitary deficit in general cognitive resources. However, recent research suggests that omission and commission errors may reflect dissociable aspects of action impairment, with only omissions associated with resource limitations. This study examined everyday action performance in 70 participants with AD who also underwent a neuropsychological evaluation. First, correlation and principal component analyses were performed to examine the construct(s) that might explain everyday action impairment. Second, relations between everyday task component(s) and neuropsychological tests were examined by using correlation and regression analyses. Third, differences in everyday action error patterns were examined among participants of comparable overall impairment levels. Results showed omission and commission errors were uncorrelated and distinct components of everyday action performance, predicted by different neuropsychological tests, and differentially distributed even among participants with comparable overall impairment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of the anti-inflammatory efficacy of Passiflora edulis

The aim of this study was to investigate the anti-inflammatory effect of the aqueous extract of Passiflora edulis forma flavicarpa Degenerer leaves in the air pouch inflammation model induced by carrageenan, histamine or substance P, in mice. An aqueous extract was prepared by infusion and lyophilized. Part of the extract was fractionated with n-butanol, resulting in the butanolic and aqueous residual fractions. The anti-inflammatory activities of the lyophilized extract and these two derived fractions were evaluated. In the inflammation induced by carrageenan, aqueous extract (100 mg/kg, i.p.), butanolic fraction (50 mg/kg, i.p.), aqueous residual fraction (100 mg/kg, i.p.) and dexamethasone (0.5 mg/kg, i.p.) inhibited the leukocyte, neutrophil, myeloperoxidase, nitric oxide, and interleukin-1 beta (IL-1β) levels (p < 0.05). The aqueous extract and butanolic and aqueous residual fractions, but not dexamethasone, decreased macrophage inflammatory protein-2 (MIP-2) levels (p < 0.05). Only dexamethasone inhibited mononuclear cells (p < 0.01). In the inflammation induced by histamine, the aqueous extract, butanolic and aqueous residual fractions, and dexamethasone inhibited total and differential leukocytes (p < 0.01). In the inflammation induced by substance P, the aqueous extract, butanolic and aqueous residual fractions, and dexamethasone also inhibited total leukocytes and mononuclears (p < 0.01). Neutrophils were only inhibited by aqueous extract, butanolic fraction, and dexamethasone (p < 0.05). In conclusion, the active principle(s) present in the P. edulis aqueous extract and its two fractions showed pronounced anti-inflammatory properties, inhibiting cell migration, proinflammatory cytokines, enzymes and mediators.     

Controlling Electrochemically Induced Volume Changes in Conjugated Polymers by Chemical Design: from Theory to Devices

Electrochemically induced volume changes in organic mixed ionic-electronic conductors (OMIECs) are particularly important for their use in dynamic microfiltration systems, biomedical machinery, and electronic devices. Although significant advances have been made to maximize the dimensional changes that can be accomplished by OMIECs, there is currently limited understanding of how changes in their molecular structures impact their underpinning fundamental processes and their performance in electronic devices. Herein, a series of ethylene glycol functionalized conjugated polymers is synthesized, and their electromechanical properties are evaluated through a combined approach of experimental measurements and molecular dynamics simulations. As demonstrated, alterations in the molecular structure of OMIECs impact numerous processes occurring during their electrochemical swelling, with sidechain length shortening decreasing the number of incorporated water molecules, reducing the generated void volumes and promoting the OMIECs to undergo different phase transitions. Ultimately, the impact of these combined molecular processes is assessed in organic electrochemical transistors, revealing that careful balancing of these phenomena is required to maximize device performance.     

Changes in reflectin protein phosphorylation are associated with dynamic iridescence in squid

Many cephalopods exhibit remarkable dermal iridescence, a component of their complex, dynamic camouflage and communication. In the species Euprymna scolopes, the light-organ iridescence is static and is due to reflectin protein-based platelets assembled into lamellar thin-film reflectors called iridosomes, contained within iridescent cells called iridocytes. Squid in the family Loliginidae appear to be unique in which the dermis possesses a dynamic iridescent component with reflective, coloured structures that are assembled and disassembled under the control of the muscarinic cholinergic system and the associated neurotransmitter acetylcholine (ACh). Here we present the sequences and characterization of three new members of the reflectin family associated with the dynamically changeable iridescence in Loligo and not found in static Euprymna iridophores. In addition, we show that application of genistein, a protein tyrosine kinase inhibitor, suppresses ACh- and calcium-induced iridescence in Loligo. We further demonstrate that two of these novel reflectins are extensively phosphorylated in concert with the activation of iridescence by exogenous ACh. This phosphorylation and the correlated iridescence can be blocked with genistein. Our results suggest that tyrosine phosphorylation of reflectin proteins is involved in the regulation of dynamic iridescence in Loligo.     

Ion‐conductivity study and anomalous diffusion analysis of plasticized gelatin films

In this article, we report a study on ion conduction in gelatin films with different concentrations of glycerol as a plasticizer; these films might be a candidate for electrolyte materials in solid polymer batteries. The ion conductivity was appreciable, showing a maximum of about 9.14 × 10^?3 S/m at room temperature without the addition of any ionic salt. Analysis of the impedance measurements was done with a model based on material properties instead of the usual equivalent circuit formalism, where circuit elements are difficult to interpret. Generalized calculus was used to model the anomalous diffusion in the system. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3018–3024, 2013     

Deposition of controlled thickness ultrathin SnO2:Sb films by spin-coating

The technological interest in transparent conductive oxide films (TCOs) has motivated several works in processing techniques, in order to obtain adequate routes to application. In this way, this work describes a new route to obtain antimony-doped tin oxide (ATO) films, based in colloidal dispersions of oxide nanocrystals. The nanoparticles were obtained by a hydrolisis method, using SnCl2 and SbCl3 in ethanolic solutions. The residual halides were removed by dyalisis, obtaining a limpid and transparent colloidal suspension. By this, the method offers the advantage of producing ultrathin films without organic contaminants. This route was employed to produce films with 5, 10, 14, and 18 mol% Sb doping, with thickness ranging from 40 to 70 nm. The physical characterization of the samples showed a uniform layer deposition, resulting in good packing density and high transmittance. A preliminar electrical study confirmed the low electrical resistivity even in the ultrathin films, in such level similar of reported data. The method described is similar in some aspects to layer-by-layer (LbL) techniques, allowing fine control of thickness and interesting properties for ultrathin films, however, with low cost when compared to similar routes.     

Development of an Ingredient Containing Apple Peel,as a Source of Polyphenols and Dietary Fiber

Abstract: Apple peel is a waste product from dried apple manufacture. The content of phenolic compounds, dietary fiber, and mineral are higher in apple peel, compared to other edible parts of this fruits. The objective of this study was to develop an ingredient from Granny Smith apple peel, using a pilot scale double drum-dryer, as drying technology. The control of all steps to maximize the retention of phenolic compounds and dietary fiber was considered. Operational conditions, such as drying temperature and time were determined, as well as important preprocessing steps like grinding and PPO inhibition. In addition, the physical–chemical characteristics, mineral and sugar content, and technological functional properties such as water retention capacity, solubility index, and dispersability among others, were analyzed. A simple, economical, and suitable pilot scale process, to produce a powder ingredient from apple peel by-product, was obtained. The drying process includes the application of ascorbic acid at 0.5% in the fresh apple peel slurry, drum-dryer operational conditions were 110 °C, 0.15 rpm and 0.2 mm drum clearance. The ingredient developed could be considered as a source of phenolic compounds (38.6 mg gallic acid equivalent/g dry base) and dietary fiber (39.7% dry base) in the formulation of foods. Practical Application: A method to develop an ingredient from Granny Smith apple peel using a pilot scale double drum-dryer as drying technology was developed. The method is simple, economical, feasible, and suitable and maximizes the retention of phenolic compounds and dietary fiber present in the raw matter. The ingredient could be used in the formulation of foods.     

Nanograined Ferroelectric Ceramics Prepared by High-Pressure Densification Technique

For the first time, nanograined Pb_{1−1.5 x} La _x TiO₃ ferroelectric ceramics, with x =0.2, were produced by a process based on a high-pressure densification technique (HPD) that eliminates the need of high-temperature sintering. Our results showed the production of workable dense ceramics with average grain size around 100 nm and free from secondary phase. Regarding the dielectric measurements, the samples showed satisfactory dielectric losses as well as remarkable diffusivity in the dielectric curves. Moreover, ferroelectric hysteresis measurements showed that samples produced by the HPD technique can stand high electric fields necessary to switch the polarization and thus to induce piezoelectric activity. Our results demonstrated clearly the viability of the proposed method to produce nanograined ferroelectric bulk ceramics, then opening the possibility of developing new technologies.