Water Formation Reaction under Interfacial Confinement: Al0.25Si0.75O2 on O-Ru(0001)

Confined nanosized spaces at the interface between a metal and a seemingly inert material, such as a silicate, have recently been shown to influence the chemistry at the metal surface. In prior work, we observed that a bilayer (BL) silica on Ru(0001) can change the reaction pathway of the water formation reaction (WFR) near room temperature when compared to the bare metal. In this work, we looked at the effect of doping the silicate with Al, resulting in a stoichiometry of Al0.25Si0.75O2. We investigated the kinetics of WFR at elevated H2 pressures and various temperatures under interfacial confinement using ambient pressure X-ray photoelectron spectroscopy. The apparent activation energy was lower than that on bare Ru(0001) but higher than that on the BL-silica/Ru(0001). The apparent reaction order with respect to H2 was also determined. The increased residence time of water at the surface, resulting from the presence of the BL-aluminosilicate (and its subsequent electrostatic stabilization), favors the so-called disproportionation reaction pathway (*H2O + *O ↔ 2 *OH), but with a higher energy barrier than for pure BL-silica.

Nanocrystals- A substantial platform for drug delivery applications.

Poor solubility of a drug is one of the major concerns in drug delivery. Many strategies have been employed for solving this problem, but there are still some deficiencies with current strategies, such as low drug loading, high toxicity, poor stability, potential drug loss during storage and complex manufacturing method. By formulating nanocrystals, problems associated with the delivery of drugs with low water or lipid solubility can be addressed. Unlike polymeric nanoparticles and lipidic nanoparticles, they are not a reservoir or matrix system. Nanocrystals are colloidal suspensions of nanosized particles stabilized by polymeric or electrostatic stabilization. They can be prepared by Top-down or Bottom-up approaches. Some of the methods for the preparation of nanocrystals are nanoprecipitation, media milling, high-pressure homogenization, emulsions and microemulsions as templates, supercritical fluid technology and co-grinding. They can be used for oral, intravenous, ocular, inhalation, intramuscular drug delivery and drug targeting.

Cinnamon Essential Oil Nanocellulose-Based Pickering Emulsions: Processing Parameters Effect on Their Formation, Stabilization, and Antimicrobial Activity

This work aimed to prepare nanocellulose-based Pickering emulsions using cinnamon essential oil. Different formulations were investigated by varying the preparation time, homogenization speed, oil and nanocellulose concentration, and morphology. The emulsions were first characterized by droplet size, morphologies, and storage stability. The Design of Experiments (DoE) was used to evaluate the parameter’s effects on the emulsions’ stability, and the emulsions with optimum particle size and stability were evaluated by antimicrobial activity. The more stable emulsions required higher energy in the system to obtain efficient emulsification. The cellulose nanocrystal (CNC) emulsions showed a 30% oil volume as a constant to obtain a low creaming index (34.4% and 42.8%) and zeta potential values around −29 mV, indicating an electrostatic stabilization. The cellulose nanofiber (CNF) emulsions showed 100% stability after a month using a 20% oil volume as a constant and Zeta potential values around −15 mV, indicating a steric stabilization. CNF-emulsions’ inhibition halos for Bacilus subtilis were 30.1 ± 3.7% smaller than those found in CNC-emulsions (65 ± 2.9 mm), while Pseudomonasaeruginosas almost do not present differences in the inhibition halos. These results suggest that the nanocellulose morphology may promote a regulation on the EO migration to the medium, as well that this migration ratio does not affect the bacteria.

2-[Carbamothioyl(2-hydroxyethyl)amino]ethyl benzoate: crystal structure, Hirshfeld surface analysis and computational study

The title di-substituted thiourea, C12H16N2O3S, has the hydroxylethyl and ethyl benzoate substituents bound to the same amine-N atom, and is twisted, having a (+)syn-clinal conformation with the Namine—C—C—O(hydroxyl, carbonyl) torsion angles of 49.39 (13) and 59.09 (12)°, respectively; the dihedral angle between the almost planar CN2S core and the pendent benzene ring is 69.26 (4)°. In the crystal, supramolecular layers propagating in the ac plane are formed via a combination of hydroxyl-O—H...S(thione), amine-N—H...O(hydroxyl, carbonyl) hydrogen-bonds. The layers stack along the b axis with inter-digitation of the benzene rings allowing the formation of π–π stacking [inter-centroid separation = 3.8722 (7) Å] and parallel C=O...π interactions. A computational chemistry study shows the conventional hydrogen bonding in the crystal leads to significant electrostatic stabilization but dispersion terms are also apparent, notably through the interactions involving the benzene residue.

TO THE QUESTION OF BASIC PRINCIPLES OF CONSTRUCTION OF THE MESOSCOPIC MODEL OF THE CISTEINE-SILVER SOLUTION

Исследована структура агрегатов меркаптида серебра (МС) в рамках крупномасштабного атомистического моделирования цистеин-серебряного раствора (ЦСР). Выполнен анализ строения, характеристик и потенциала взаимодействия супрамономеров в составе агрегатов МС. Эти данные являются основой для перехода на мезоскопический уровень моделирования ЦСР. В работе также рассмотрен вопрос о роли соли инициатора в нарушении электростатической стабилизации ЦСР. The analysis of the structure of silver mercaptide (SM) aggregates obtained in the framework of large-scale atomistic modeling of L-cysteine and silver nitrate solution (CSS) was performed. Information was obtained on the structure, characteristics and interaction of supramonomers forming SM aggregates. These data can serve as the basis for the transition to the mesoscopic level of CSS simulations The paper also examined the role of the initiator salt in disrupting the electrostatic stabilization of the CSS.

Nutraceutical approach to enhance lutein bioavailability via nanodelivery systems

Lutein, a potent dietary carotenoid, has considerable biological activity and confers protection against age-related macular degeneration. Its bioavailability following consumption, however, depends on its rate of degradation. Nanodelivery systems with improved efficacy and stability are currently being developed to increase the bioavailability of lutein. This review examines nutraceutical approaches used in the development of such nanodelivery systems. It describes the methods of lutein preparation, the characteristics of various delivery systems, and the lutein delivery profile. In order to enhance lutein loading, provide electrostatic stabilization, and achieve the controlled release of lutein, adjuvants such as dextran moieties, whey proteins, medium-chain triglycerides, and chitosan polymers can be used to effectively reduce the particle size (< 70 nm) and improve encapsulation efficiency (to 99.5%). The improved bioavailability of lutein via nanocrystals incorporated into rapidly dissolving films for oral consumption is a new area of exploratory research. This review aims to provide clarity about current research aimed at enhancing the bioavailability of lutein through the development of nanodelivery systems.