Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ultsonch.2017.08.004.The ultrasound-assisted hydrolysis of aspirin methyl ester (AME) was investigated using immobilized Candida antarctica lipase B (CALB) (1%) in the presence of solvents like triolein, chloroform (CHCl3) and dichloromethane (DCM). The effect of ultrasound and the role of water on the conversion rates have also been investigated. Proton nuclear magnetic resonance spectroscopic (1H NMR) was chosen to calculate hydrolysis convertion rates. We observed that lipase-ultrasound assisted hydrolysis of AME in the presence of triolein and water showed the highest hydrolysis conversion rate (65.3%). Herein low water amount played an important role as a nucleophile being crucial for the hydrolysis yields obtained. Lipase activity was affected by the conjugated action of ultrasound and solvents (35.75% of decrease), however not disturbing its hydrolytic efficiency. It was demonstrated that lipase is able to hydrolyse AME to methyl 2-hydroxy benzoate (methyl salicylate), which applications include fragrance agents in food, beverages and cosmetics, or analgesic agent in liniments.All authors gratefully acknowledge the financial support provided by International Joint Research Laboratory for Textile and Fibre Bioprocesses at Jiangnan University. The authors are also thankful to the Department of Oils, Oleochemicals and Surfactants technology, Institute of Chemical Technology, Mumbai, India and to the Bioprocess and Bio nanotechnology Research Group (BBRG) of University of Minho. Authors would like also to acknowledge the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte and to the Fundamental Research Funds for the Central Universities (No. JUSRP51622 A and No. JUSRP115A03), and to the Jiangsu Province Scientific Research Innovation Project for Academic Graduate Students in 2016 (No. KYLX16_0788).info:eu-repo/semantics/publishedVersio

An integrated model of technology acceptance for mobile computing

Technology acceptance models have been an important area of research in the Information Systems arena especially in the last 20 years. Most technology acceptance studies use factors from Davis\u27s Technology Acceptance Model (TAM), Davis and Venkatesh\u27s Extended Technology Acceptance Model (TAM2), Ajzen\u27s Theory of Planned Behavior (TPB), and/or Goodhue\u27s Task-Technology Fit (TTF) model. This study integrates factors from these four models and focuses on the acceptance of mobile computing. The purpose of this research is fourfold. First, the research improves the understanding of technology acceptance for mobile computing devices. It does this by examining the components of four known technology acceptance models (TAM, TAM2, TPB, TTF). Using the definition of each component the research assesses which factors should be extracted into an integrated technology acceptance model for mobile computing devices. Subsequent interviews of PDA users resulted in the identification of three additional factors for the integrated model. The factors are adaptability, mobility, and security. Second, this derived model is useful for technology acceptance not only for mobile computing but also for location dependent domains, since the factors are derived from general purpose technology acceptance models. Third, the research assesses this integrated model. For this research the PDA is selected as an example of a mobile computing device. A questionnaire exploring the relevance of factors in the integrated model was constructed from those items used in previous models. These questions were included in a survey and augmented by questions from literature. The questionnaire was developed and administered to 134 PDA users from 5 different groups. The answers to the questionnaire have confirmed the importance of the additional factors in that the results of the questionnaire analysis points to the conclusion that respondents find adaptability, mobility and to a lesser extent security are important to them. The research uses a set of new analysis techniques, namely data mining, which shows the integrated model is the one of the best predictors of the measurement of usage behavior. In some cases the prediction is several percentage points higher for each of the four contributing models. Furthermore the data mining information gain analysis find mobility to be the second largest predictor variable for intention to use indicating that in the minds of these users mobility is significantly important in accepting the technology. Fourth, the research explains the relationships between the factors. Using regression analysis and correlation coefficients the research shows that mobility is the strongest of the three new factors because it is related to 13 of the other 14 factors. The other two new factors show significant correlation with one another

Effect of exogenous administration of Candida albicans autoregulatory alcohols in a murine model of hematogenously disseminated candidiasis

Candida albicans supernatants contain a mixture of autoregulatory alcohols. In vitro, when added individually or in combination, these alcohols inhibit the yeast to filamentous form conversion. Here we evaluate the in vivo effect of the exogenous administration of a Cocktail solution simulating the composition of alcohols present in a C. albicans culture supernatant(1 ml; 94 μmol l–1 isoamyl alcohol, 70 μmol l–1 2-phenylethanol, 3.2 n mol l–1 E-nerolidol, and 18 n mol l–1 E,E-farnesol) using the well established murine model of hematogenously disseminated candidiasis. Mice injected intraperitoneally with the Cocktail solution demonstrated increased survival and decreased organ fungal burden compared to control mice. Histological observations suggest that the Cocktail, to some extent, has an inhibitory effect on cell filamentation within the kidney. These findings suggest that the exogenous administration of C. albicans autoregulatory alcohols displays a protective effect during disseminated candidiasis.M. M. was financially supported by a fellowship from Fundacao para a Ciencia e Tecnologia, Portugal (contracts SFRH/BD/28222/2006 and SFRH/BPD/73663/2010), co-financed by the Programa Operacional Potencial Humano (POPH)/Fundo Social Europeu (FSE). Work in the laboratory of J.L.L.-R. is supported by grant number R21AI080930 from the National Institute of Allergy and Infectious Diseases. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIAID or the NIH

Macrocyclic fragrance materials: A screening-level environmental assessment using chemical categorization

A screening-level aquatic environmental risk assessment for macrocyclic fragrance materials using a "group approach" is presented using data for 30 macrocyclic fragrance ingredients. In this group approach, conservative estimates of environmental exposure and ecotoxicological effects thresholds for compounds within two subgroups (15 macrocyclic ketones and 15 macrocyclic lactones/lactides) were used to estimate the aquatic ecological risk potential for these subgroups. It is reasonable to separate these fragrance materials into the two subgroups based on the likely metabolic pathway required for biodegradation and on expected different ecotoxicological modes of action. The current volumes of use for the macrocyclic ketones in both Europe and North America ranges from < 1 (low kg quantities) to no greater than 50 metric tonnes in either region and for macrocyclic lactones/lactides the volume of use range for both regions is < 1 to no greater than 1000 metric tonnes in any one region. Based on these regional tonnages, biodegradability of these two subgroups of materials, and minimal in stream dilution (3:1), the conservatively predicted exposure concentrations for macrocyclic ketones would range from < 0.01 to 0.05 mu g/L in Europe and from < 0.01 to 0.03 mu g/L in North America. For macrocyclic lactones/lactides, the concentration within the mixing zone would range from < 0.01 to 0.7 mu g/L in Europe and from < 0.01 to 1.0 mu g/L in North America. The PNECs derived for the macrocyclic ketones is 0.22 mu g/L and for macrocyclic lactones/lactides is 2.7 mu g/L. The results of this screening-level aquatic ecological risk assessment indicate that at their current tonnage, often referred to as volumes of use, macrocyclic fragrance materials in Europe and North America, pose a negligible risk to aquatic biota; with no PEC/PNEC ratio exceeding 1 for any material in any subgroup. (C) 2011 Elsevier Inc. All rights reserved