Search results for " technology"

Les enjeux de la sécurité des objets connectés et applications de santé

2016

International audience; The challenges of security of connected objects and health applicationsThe market for connected objects and health applications is booming and is expected to be several billion euros in revenue in the coming years. Their development will have a similar impact to what we experienced with the development of internet earlier this century but even more it should disrupt the organization of our health system, profoundly change the management of care and revolutionize prevention, but it could also call into question medical confidentiality and protection of personal data. This article analyses the societal implications of OCS, the need for a dual medical and ethical evalua…

2,4,5-Triaryl imidazole probes for the selective chromo-fluorogenic detection of Cu(II). Prospective use of the Cu(II) complexes for the optical reco…

2019

The sensing behaviour toward metal cations and biothiols of two 2,4,5-triarylimidazole probes (3a and 3b) is tested in acetonitrile and in acetonitrile-water. In acetonitrile the two probes present charge-transfer absorption bands in the 320-350 nm interval. Among all cations tested only Cu(11) is able to induce bathochromic shifts of the absorption band in the two probes, which is reflected in marked colour changes. Colour modulations are ascribed to the formation of 1:1 Cu(II)-probe complexes in which the cation interacts with the imidazole acceptor heterocycle. Besides, the two probes present intense emission bands (at 404 and 437 nm for 3a and 3b respectively) in acetonitrile that are q…

9,10-Phenanthrenedione as Visible-Light Photoredox Catalyst: A Green Methodology for the Functionalization of 3,4-Dihydro-1,4-Benzoxazin-2- Ones thro…

2018

A visible-light photoredox functionalization of 3,4-dihydro-1,4-benzoxazin-2-ones through a Friedel-Crafts reaction with indoles using an inexpensive organophotoredox catalyst is described. The reaction uses a dual catalytic system that is formed by a photocatalyst simple and cheap, 9,10-phenanthrenedione, and a Lewis acid, Zn(OTf)2. 5W white LEDs are used as visible-light source and oxygen from air as a terminal oxidant, obtaining the corresponding products with good yields. The reaction can be extended to other electron-rich arenes. Our methodology represents one of the most valuable and sustainable approach for the functionalization of 3,4-dihydro-1,4-benzoxazin-2-ones, as compared to th…

Crystallographic snapshots of host–guest interactions in drugs@metal–organic frameworks: towards mimicking molecular recognition processes

2018

We report a novel metal–organic framework (MOF) featuring functional pores decorated with hydroxyl groups derived from the natural amino acid L-serine, which is able to establish specific interactions of different natures, strengths and directionalities with organic molecules of technological interest, i.e. ascorbic acid, pyridoxine, bupropion and 17-β-estradiol, based on their different sizes and chemical natures. The ability of 1 to distinctly organize guest molecules within its channels, through the concomitant effect of different directing supramolecular host–guest interactions, enables gaining unique insights, by means of single-crystal X-ray crystallography, into the host–guest intera…

Formation of dibutyl carbonate and butylcarbamate via CO2 insertion in titanium(IV) butoxide and reaction with n-butylamine

2016

Abstract The species resulting from insertion of 12CO2 and 13CO2 into titanium(IV) butoxide is for the first time fully characterized by means of infrared and nuclear magnetic resonance spectroscopy. Results show formation of Ti-monobutylcarbonate, that easily undergoes nucleophilic attack by an aliphatic amine. The hydrolysis of the resulting species produces butylcarbamate and dibutylcarbonate as the only main products. Characterization results of the carbonate-like adduct, along with its reactivity with amine molecules open the route to new ways of CO2 utilization as building block for valuable organic compounds.

Green synthesis of cavity-containing manganese oxides with superior catalytic performance in toluene oxidation

2019

10 Figuras.- 2 Tablas.- Datos suplementarios disponibles en línea en la página web del editor.-- © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

Automated Diffraction Tomography for the Structure Elucidation of Twinned, Sub-micrometer Crystals of a Highly Porous, Catalytically Active Bismuth M…

2012

Comparative hydroamination of aniline and substituted anilines with styrene on different zeolites, triflate based catalysts and their physical mixtur…

2014

Abstract Catalytic performances of different zeolites (Beta and mordenites), scandium triflate based catalysts, mesoporous UVM-7 encapsulated scandium triflate and physical mixtures prepared under ultrasound irradiation were evaluated in the hydroamination of aniline and substituted anilines with styrene. The performances of these catalysts were controlled by the type of acidity and strength. Thus, the conversion was mainly controlled by the strength of the acid sites and their accessibility, while the selectivity appeared to be controlled by the Lewis/Bronsted type of acidity. Lewis acid catalysts directed the reactions mainly to the formation of the Markovnikov adducts while Bronsted acid…

Hierarchical Beta zeolites obtained in concentrated reaction mixtures as catalysts in tetrahydropyranylation of alcohols

2020

Abstract Hierarchical zeolites consisting of Beta nanoparticles (15–40 nm) were obtained via hydrothermal treatment of a concentrated zeolite gel-precursor (H2O/Si = 2.5–14) without utilization of complex SDAs. The proposed approach is based on the formation of a large number of zeolite nuclei under particular crystallization conditions, followed by their agglomeration resulting in the dense packing of the particles preventing their further growth. The micelles of cetyltrimethylammonium bromide (CTAB) can be used to additionally limit the growth of zeolite nanoparticles during hydrothermal treatment of concentrated reaction mixtures. Such deceleration of crystallization promotes the formati…

Research Regarding the Physical-Mechanical Properties of Knits for Garments – Abrasion Resistance

2017

Abstract During wear, the fabric is subjected to a complex combination of forces acting at various rates, in various intensities, in various directions and for various periods. This is one of the main causes of a fabric and garment becoming unacceptable for further wear. The main goal of this research paper is to improve the physical-mechanical properties of knits for garments by choosing the right fabric structure and raw material. The abrasion resistance is a mechanical deterioration and progressive loss of substance from a fabric, resulting from the fabric rubbing against itself or another surface. Tests was done on weft knitted fabric for garments using cotton, wool and mixed yarns, thr…