Position matters : fluorescent positional isomers for reversible multichannel encryption devices

Fluorescence signals have been widely used in information encryption for a few decades, but still suffer from limited reliability. Here, reversible multichannel fluorescent devices with encrypted information were constructed, based on two fluorescent positional isomers of a diphenylquinoxaline derivative. Possessing the same core fluorescent group and acid-/pH-responsive mechanism, the two isomers showed different fluorescence color in an acidic environment, which allowed us to realize stepwise encryption of information in orthogonal fluorescence channels. Since the protonation was reversible, the revealed information could be re-encrypted, simply by heating. This approach highlights the value of positional isomers to build multichannel encryption devices, improving their reliability on the molecular level

Evaluation De La Qualité Physico-Chimique Des Eaux Souterraines Au Voisinage De La Décharge Contrôlée Mohammedia-Benslimane : (Étude Préliminaire)

L’intérêt de la présente étude est de déterminer la qualité des eaux souterraines au voisinage de la décharge contrôlée de Mohammedia- Benslimane installée dans la région depuis 2012. Il s’agit des eaux de 7 puits destinées à l’irrigation et/ou à la consommation. Les résultats obtenus sont comparés aux normes marocaines et montrent que les teneurs en chlorures sont très élevées dans tous les puits (158.2 à 845.6 mg/L) et dépassent largement les normes d’irrigation (105 mg/L). La DCO varie entre (34.6 et 67.2 mg O2/L) dans cinq puits, ces valeurs sont élevées par rapport à la valeur admissible de l’eau potable (25 mg O2/L). Les concentrations enregistrées pour le Cu, Fe, Mn, Zn et Ni correspondent bien aux normes d’irrigation et de potabilité des eaux. Cependant les teneurs en Pb varient entre (0.07 et 0.14mg/L) dans 4 puits dont 3 sont situés en aval de la décharge. Ces valeurs dépassent celles de la norme de potabilité (0.05 mg/L). Les concentrations les plus élevées en chrome sont observées dans trois puits situés en amont de la décharge et un à l’aval. En ce qui concerne le cadmium, ses teneurs ne dépassent pas les normes de potabilité et d’irrigation, à l’exception d’un puits situé à l’aval de la décharge et dont la valeur dépasse de (0,001 mg/L) la norme de potabilité. Enfin, la qualité générale des eaux étudiées serait probablement liée aux activités humaines et à la nature du sol traversé par les eaux pluviales et non à la décharge. The aim behind this study is to determine the quality of the groundwater surrounding the landfill that has taken place in Mohammedia- Benslimane since 2012. It is a matter of seven wells dedicated to irrigation and/or daily use. The results obtained are compared to Moroccan standards and clearly show that the chlorides levels are abnormally high amongst all the wells (158.2 to 845.6 mg/L) and go well beyond the irrigation’s standards (105 mg/L). The chemical oxygen demand (COD) varies between (34.6 and 67.2 mg O2/L) in five of the wells: values that exceed the allowed drinking water’s value (25 mg O2/L). The recorded concentrations of the Cu, Fe, Mn, Zn and the Ni are well aligned with the standards of irrigation and drinking water quality. However, the Pb levels, which exceed the standards of potability (0.05 mg/L) range from(0.07 and 0.14 mg/L). The highest chromiumconcentrations were recorded in three of the wells upstream from the landfill and a single one amongst the ones located downstream. Even though the Cadmium levels are aligned with the standards of potability and irrigation in six of the wells, it remains exceeding the standards of the drinking water quality by (0.001 mg/L). As a conclusion, the overall quality of the studied groundwater would probably be linked to the human activities on the surroundings, as well as to the nature of the ground crossed by the stormwater not to the landfill

Nanolayer laser absorber for femtoliter chemistry in polymer reactors

Laser-induced forward transfer (LIFT) has the potential to be an alternative approach to atomic force microscopy based scanning probe lithography techniques, which have limitations in high-speed and large-scale patterning. However, traditional donor slides limit the resolution and chemical flexibility of LIFT. Here, we propose a hematite nanolayer absorber for donor slides to achieve high-resolution transfers down to sub-femtoliters. Being wettable by both aqueous and organic solvents, this new donor significantly increases the chemical scope for the LIFT process. For parallel amino acid coupling reactions, the patterning resolution can now be increased more than five times (>111,000 spots/cm2 for hematite donor versus 20,000 spots/cm2 for standard polyimide donor) with even faster scanning (2 versus 6 ms per spot). Due to the increased chemical flexibility, we could explore other types of reactions inside ultrasmall polymer reactors: copper (I) catalyzed click chemistry and laser-driven oxidation of a tetrahydroisoquinoline derivative, suggesting the potential of LIFT for both deposition of chemicals and laser-driven photochemical synthesis in femtoliters within milliseconds. Since the hematite shows no damage after typical laser transfer, donors can be regenerated by heat treatment. These findings will transform the LIFT process into an automatable, precise, and highly efficient technology for high-throughput femtoliter chemistry

Microwave-irradiated rapid synthesis of antimicrobial pyrazine derivatives in reactive eutectic media

Herein, we report of the use of reactive eutectic media from ammonium formate and monosaccharides to synthesize poly(hydroxyalkyl)pyrazines via microwave irradiation. This enabled unprecedented fast rates as well as better atom economy compared to previous methods. We investigated the influence of water on the reaction yield as well as the physical properties of the eutectic media and could thereby drastically reduce the viscosity, while preserving high reaction yields. The results were consistent for different monosaccharide, using fructose, glucose, rhamnose and fucose as reactants. Furthermore, the major reaction products were separated, chemically analyzed and tested on their antimicrobial activity via high-throughput screening

Traitement Expérimental Par Coagulation Floculation Des Effluents Brutes D’une Industrie Aéronautique À Casablanca (Maroc)

Les effluents de l’industrie de traitement de surface présentent souvent une forte charge en produits chimiques très toxiques qui doivent être traités conformément à une réglementation de plus en plus stricte. Dans ce travail, nous avons effectué une caractérisation des effluents liquides d’une unité de traitement de surface au Maroc qui a révélé une forte pollution colloïdale (Turbidité=131 NTU), une charge en matière oxydable élevée (DCO = 960 mg/l) et en éléments métalliques (Fer, cuivre, zinc, nickel, aluminium, chrome et cyanure). L’objectif de cette étude expérimentale consiste à appliquer un traitement physico-chique par coagulation-floculation à ces eaux uses industrielles toxiques en vue de les conformer aux normes de rejet dans le réseau d’assainissement local. En effet, ce traitement, précédé d’un ajustement du pH, une oxydation des cyanures et d’une réduction du chrome hexavalent, a abouti à une réduction très satisfaisante de la toxicité de ces effluents avec des taux d’abattement de 94% pour la DCO et jusqu'à 99 % pour la turbidité et charge métallique. Effluents from the surface treatment industry often have a high load o f highly toxic chemicals that need to be treated in accordance with increasing ly stringent regulations. In this work, we performed a characterization of liqu id effluents from a surface treatment unit in Morocco that revealed high collo idal pollution (Turbidity=131 NTU), high stainless material (COD=960 mg/l ) and metal elements (Iron, copper, zinc, nickel, aluminum, chromium and cy anide). The objective of this experimental study is to apply a physico-chemical treatment by coagulation-flocculation to these toxic industrial wastewater in order to comply with the discharge standards in the local sewage system. This treatment, preceded by pH adjustment, cyanide oxidation and reduction of hexavalent chromium, resulted in a very satisfactory reduction in toxicity of these effluents with abatement rates of 94% for COD and up to 99% for turbidity and metal load

Three-Dimensional Printing of Ellipsoidal Structures Using Mercury

A description of how to use the Mercury software from the CCDC to print 3-dimensional crystal structures that depict the anisotropic displacement parameters, matching the commonly used ellipsoidal depiction used in scientific papers. Details on how to convert a cif file into a 3D printing data file is included in the main paper, and details on the preparation of that data file for printing on a number of different 3D printers is included in the ESI.<br /

Three-Dimensional Printing of Ellipsoidal Structures Using Mercury

A description of how to use the Mercury software from the CCDC to print 3-dimensional crystal structures that depict the anisotropic displacement parameters, matching the commonly used ellipsoidal depiction used in scientific papers. Details on how to convert a cif file into a 3D printing data file is included in the main paper, and details on the preparation of that data file for printing on a number of different 3D printers is included in the ESI.<br