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

.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

Transfer of Electronic Excitation Energy between Randomly Mixed Dye Molecules in the Channels of Zeolite L

Host-guest materials containing strongly fluorescent donor and acceptor molecules have been prepared. Fine-tuning of the donor to acceptor distance in this material allows beautiful visible and quantitative observation of electronic excitation energy transfer phenomena. Oxonine and pyronine have been used as guest molecules and zeolite L as host. The dyes have been inserted by ion exchange. Stationary state and time-resolved experiments have been carried out with zeolite crystals of 300 and 700 nm size in the dye concentration range of 10-4 mol/L up to 0.042 mol/L. The fluorescence decay of the donor and the pumping of the acceptor via energy transfer, which can be well observed, became faster with increasing loading. The behavior of the system follows requirements expected for Förster energy transfer material. 1

The many dimensions of laboratories ' interdisciplinarity

Abstract: Interdisciplinarity is as trendy as it is difficult to define. We propose three different operationalizations of a discipline and two levels (article or laboratory) of integration of these disciplines. This leads to six indicators of interdisciplinarity, achieving a rich characterization of laboratories publication practices. Thanks to a statistical analysis of these indicators on 600 CNRS laboratories, we suggest that, besides an average value of interdisciplinarity, different laboratories can be distinguished by the “distance ” between the disciplines in which they publish and by the level of interdisciplinary integration (article or laboratory). hal-00785249, version 1- 5 Feb 2013 CNRS is the largest scientific organization in Europe, covering most fields of science. According to its website, “CNRS encourages collaboration between specialists from different disciplines [...] thus opening up new fields of enquiry to meet social and economic needs. CNRS has develope

Models of neural networks in computer aided learning

Дан анализ особенностей обучения человека и машины, реализующей искусственную нейронную сеть. Рассмотрена концепция процесса обучения, применимая в условиях удаленности и ограниченности информационных ресурсов. Сформулированы рекомендации по оцениванию объема множества данных для обучения. Main features of human learning procedures via the machine learning procedures are analyzed. The approach to the training procedure in the case of distant and limited information resources is considered. Directions for dataset volume estimation are formulated

Nanochannels for Supramolecular Organisation of Dyes

The supramolecular organisation of molecules, complexes or clusters is a fruitful concept for the design of systems exhibiting specific macroscopic properties. The encapsulation of guest species into the pores or channels of host materials presents a challenging approach to the preparation of novel chemical and optical materials. Zeolite L has been shown to be an ideal host for the supramolecular organisation of organic dyes. A new hierarchy of structural ordering can be achieved by either arranging the zeolite L crystals into densely packed, oriented monolayers or by interfacing them to the environment via molecules bound to the edges of the crystals. These concepts are reviewed here, as well as some potential applications