116 research outputs found

    Ultrasonic-assisted ruthenium-catalyzed one-pot synthesis of biscoumarins

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    The Ru-grafted zeolite beta was found to be an excellent heterogeneous catalyst for one-pot synthesis of biscoumarins. This reaction was carried out under reflux condition and ultrasonic irradiation. On the other hand, the catalyst could be recovered for the subsequent reactions and reused without appreciable loss of activity

    Effectiveness of Theory-Based Intervention on Knowledge Level, Psychological Constructs, Metabolic Index and Physical Activity Status in Patients with Type 2 Diabetes: Application of the Health Action Process Approach (HAPA) Model

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    Objective: The aim of the study was to determine the effect of the educational intervention based on the health action process approach (HAPA) model on the level of knowledge, metabolic indicators, psychological constructs and physical activity status in type 2 diabetes (T2D) patients in 2022–2023. Material and methods: The present study was a randomized controlled trial and 100 T2D patients were equally assigned to experimental and control groups using multistage random sampling. The educational program included six online sessions, targeted pamphlets, educational audio files and reminder messages. Data were collected before and 3 months after intervention with demographic items, awareness scale, constructs of HAPA model, IPAQ-s, HbA1c and fasting blood glucose (FBG). Data were entered to SPSS 25.0 and analyzed with chi-square, ANOVA and ANCOVA. Results: After controlling the effect of the pre-test variable, the mean of the HAPA model constructs and mean of physical activity improved significantly in posttest. In addition, educational intervention explained 30.2%, 57.8%, 33.2%, 64.4%, 76.3%, 25.3%, 24.6%, 36.1% and 36.9% of the variance of health awareness, risk perception, outcome expectancy, action self-efficacy, maintenance self-efficacy, action plan, coping plan, behavioral intention and physical activity, respectively. In addition, the mean of FBG and HbA1c in the experimental group improved significantly after the intervention by controlling the pre-test effect (p < 0.001). Conclusions: Providing theory-based educational interventions through the web and mobile can increasingly promote the effectiveness of cognitive behavioral interventions and facilitate the process of behavior change in T2D

    On the use of porous nanomaterials to photoinactivate E. coli with natural sunlight irradiation

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    .An organic-inorganic hybrid material based on nanocrystals of zeolite L functionalized with silicon phthalocyanine can develop interesting properties when activated by natural sunlight. Cell viability tests show that this nanomaterial is able to photoinactivate mouse cells and Escherichia coli (. E. coli) bacteria, and is also very efficient against the self-defense mechanisms of E. coli during the first minutes of solar irradiation. The results suggest that Gram-negative E. coli become more resistant to singlet oxygen-based disinfection treatments at higher temperatures. The present work contributes to the development of new functional materials for a range of important sunlight-based applications. © 2015 Elsevier Lt

    Potentiometric Electronic Tongue to Resolve Mixtures of Sulfide and Perchlorate Anions

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    This work describes the use of an array of potentiometric sensors and an artificial neural network response model to determine perchlorate and sulfide ions in polluted waters, by what is known as an electronic tongue. Sensors used have been all-solid-state PVC membrane selective electrodes, where their ionophores were different metal-phtalocyanine complexes with specific and anion generic responses. The study case illustrates the potential use of electronic tongues in the quantification of mixtures when interfering effects need to be counterbalanced: relative errors in determination of individual ions can be decreased typically from 25% to less than 5%, if compared to the use of a single proposed ion-selective electrode

    Exploitation of Unique Properties of Zeolites in the Development of Gas Sensors

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    The unique properties of microporous zeolites, including ion-exchange properties, adsorption, molecular sieving, catalysis, conductivity have been exploited in improving the performance of gas sensors. Zeolites have been employed as physical and chemical filters to improve the sensitivity and selectivity of gas sensors. In addition, direct interaction of gas molecules with the extraframework cations in the nanoconfined space of zeolites has been explored as a basis for developing new impedance-type gas/vapor sensors. In this review, we summarize how these properties of zeolites have been used to develop new sensing paradigms. There is a considerable breadth of transduction processes that have been used for zeolite incorporated sensors, including frequency measurements, optical and the entire gamut of electrochemical measurements. It is clear from the published literature that zeolites provide a route to enhance sensor performance, and it is expected that commercial manifestation of some of the approaches discussed here will take place. The future of zeolite-based sensors will continue to exploit its unique properties and use of other microporous frameworks, including metal organic frameworks. Zeolite composites with electronic materials, including metals will lead to new paradigms in sensing. Use of nano-sized zeolite crystals and zeolite membranes will enhance sensor properties and make possible new routes of miniaturized sensors

    Solid-state ion exchange in zeolites

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    Metal-Substituted Microporous Aluminophosphates

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    This chapter aims to present the zeotypes aluminophosphates (AlPOs) as a complementary alternative to zeolites in the isomorphic incorporation of metal ions within all-inorganic microporous frameworks as well as to discuss didactically the catalytic consequences derived from the distinctive features of both frameworks. It does not intend to be a compilation of either all or the most significant publications involving metal-substituted microporous aluminophosphates. Families of AlPOs and zeolites, which include metal ion-substituted variants, are the dominant microporous materials. Both these systems are widely used as catalysts, in particular through aliovalent metal ions substitution. Here, some general description of the synthesis procedures and characterization techniques of the MeAPOs (metal-contained aluminophosphates) is given along with catalytic properties. Next, some illustrative examples of the catalytic possibilities of MeAPOs as catalysts in the transformation of the organic molecules are given. The oxidation of the hardly activated hydrocarbons has probably been the most successful use of AlPOs doped with the divalent transition metal ions Co2+, Mn2+, and Fe2+, whose incorporation in zeolites is disfavoured. The catalytic role of these MeAPOs is rationalized based on the knowledge acquired from a combination of the most advanced characterization techniques. Finally, the importance of the high specificity of the structure-directing agents employed in the preparation of MeAPOs is discussed taking N,N-methyldicyclohexylamine in the synthesis of AFI-structured materials as a driving force. It is shown how such a high specificity could be predicted and how it can open great possibilities in the control of parameters as critical in catalysis as crystal size, inter-and intracrystalline mesoporosity, acidity, redox properties, incorporation of a great variety of heteroatom ions or final environment of the metal site (surrounding it by either P or Al)
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