Access to Enantiopure α‐Alkyl‐β‐hydroxy Esters through Dynamic Kinetic Resolutions Employing Purified/Overexpressed Alcohol Dehydrogenases

α‐Alkyl‐β‐hydroxy esters were obtained via dynamic kinetic resolution (DKR) employing purified or crude E. coli overexpressed alcohol dehydrogenases (ADHs). ADH‐A from R. ruber, CPADH from C. parapsilosis and TesADH from T. ethanolicus afforded syn‐(2R,3S) derivatives with very high selectivities for sterically not impeded ketones (‘small‐bulky’ substrates), while ADHs from S. yanoikuyae (SyADH) and Ralstonia sp. (RasADH) could also accept bulkier keto esters (‘bulky‐bulky’ substrates). SyADH also provided preferentially syn‐(2R,3S) isomers and RasADH showed in some cases good selectivity towards the formation of anti‐(2S,3S) derivatives. With anti‐Prelog ADHs such as LBADH from L. brevis or LKADH from L. kefir, syn‐(2S,3R) alcohols were obtained with high conversions and diastereomeric excess in some cases, especially with LBADH. Furthermore, due to the thermodynamically favoured reduction of these substrates, it was possible to employ just a minimal excess of 2‐propanol to obtain the final products with quantitative conversions.     

Side chain porphyrin moiety linked to polymer-fullerene composite solar cell

This work investigates the photovoltaic properties of a BHJ solar cell made of an active layer constituted by phenyl-C₆₁-butyric acid methyl ester and a novel polyalkylthiophene derivative functionalized in the side chain with porphyrin dye. The polymer was fully characterized by FT-IR, NMR, UV–vis, GPC, DSC and TGA techniques and the active layer by cyclic voltammetry and AFM. The results of this study indicate that the solar cell made of polythiophene containing a 25% molar content of sensitizer dye as the active layer, exhibits higher power conversion efficiency, short circuit current and fill factor values than the reference cell based on polythiophene completely devoid of porphyrin.     

Correlating the solubility of supercritical gases in high‐molecular weight substances using a density‐dependent equation

Chrastil (1982) established that the solubility of a substance in a supercritical fluid can be correlated with the density of the pure supercritical gas. Recently, the solubility of supercritical fluids in different organic liquids was successfully correlated as a function solely of the supercritical fluid density, since we demonstrated that the supercritical fluid density also defines the solubility of the gas in the liquid phase. In this work, the solubility of supercritical carbon dioxide in high‐molecular weight substances, such as high‐molecular weight paraffins, alcohols, fatty acids, fatty acid methyl and ethyl esters, has been correlated and constants provided. More than 20 binary systems comprising around 1000 solubility data points were correlated, obtaining regression coefficients greater than 0.96 and confirming the goodness of the density‐dependent equation previously reported. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

Solid State Analysis of Metal-Containing Polymers Employing Mössbauer Spectroscopy, Solid State NMR and F EI TOF MALDI MS

Polymers in general and metal-containing polymers in particular are often sparingly soluble or insoluble, in contrast to small molecules. Thus, special significance is attached to characterization techniques that can be applied to the materials as solids. Here, three techniques are discussed that give structural information gained from the solid material. Mössbauer spectroscopy is a powerful technique that may give information on the structure about the metal-containing moiety for about 44 different nuclei. Its use in describing the structure of the product obtained from organotin dichlorides and the unsymmetrical ciprofloxacin is presented along with the reaction implications of the results. Solid state NMR is also a useful tool in describing the structure of metal-containing polymers and its use is briefly described. Finally, MALDI MS can be used to gain structural information. For many metals it is particularly useful because of the presence of different isotopes that allow the identification of units through comparison of these isotope abundances with ion fragment clusters. Each of these tools can provide important structural characterization information.     

Eruca sativa Might Influence the Growth,Survival under Simulated Gastrointestinal Conditions and Some Biological Features of Lactobacillus acidophilus,Lactobacillus plantarum and Lactobacillus rhamnosus Strains

The growth and viability of three Lactobacillus strains, Lactobacillus acidophilus, Lactobacillus plantarum and Lactobacillus rhamnosus, after their passage through simulated gastric and pancreatic juices were studied as a function of their presence in the growth medium of rocket salad (Eruca sativa). The presence of E. sativa affected some of the biological properties of the strains. For example, L. acidophilus and L. plantarum worked more efficiently in the presence of E. sativa, increasing not only the antioxidant activity of the medium, but also their own antioxidant power and antimicrobial activity; L. rhamnosus was not affected in the same manner. Overall, the presence of vegetables might help to boost, in specific cases, some of the characteristics of lactobacilli, including antioxidant and antimicrobial power.     

Extraction of caffeine from natural matter using a bio-renewable agrochemical solvent

This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications.Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 °C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources.     

A unified methodology for the evaluation of accessibility and usability of mobile applications

This article reports a unified methodology developed to evaluate the accessibility and usability of mobile computing applications, which is intended to guarantee universal access as far as possible. As a basis for the methodology, this paper presents an analysis of the accessibility guidelines, conducted to take into account the specificity of mobile systems, as well as a set of usability heuristics, specifically devised for mobile computing. Finally, it presents the results of the application of the proposed methodology to applications that have been semi-automatically developed by the MAIS Designer, a new design tool that provides applications suited to different mobile devices.     

Tools and algorithms for the construction and analysis of systems: a special issue for TACAS 2017

International Journal on Software Tools for Technology Transfer - This special issue of Software Tools for Technology Transfer presents extended versions of two selected papers from the 23rd...