This review includes the most relevant aspects of the microplastics' presence in the atmosphere, with a complete analysis of possible sources, transport mechanisms, and the health risks associated with these emerging and bio-persistent pollutants.

The use of dyes at an industrial level has become problematic, since the discharge of dye effluents into water disturbs the photosynthetic activity of numerous aquatic organisms by reducing the penetration of light and oxygen, in addition to causing carcinogenic diseases and mutagenic effects in humans, as well as alterations in different ecosystems. Chitosan (CS) is suitable for removing anionic dyes since it has favorable properties, such as acquiring a positive charge and a typical macromolecular structure of polysaccharides. In this study, the optimization of CS beads crosslinked with glutaraldehyde (GA) for the adsorption of reactive blue dye 4 (RB4) in an aqueous solution was carried out. In this sense, the response surface methodology (RSM) was applied to evaluate the concentration of CS, GA, and sodium hydroxide on the swelling degree in the GA-crosslinked CS beads. In the same way, RSM was applied to optimize the adsorption process of the RB4 dye as a function of the initial pH of the solution, initial concentration of the dye, and adsorbent dose. The crosslinking reaction was investigated by scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), and X-ray diffractometry (XRD). The design described for the swelling degree showed an R² (coefficient of determination) adjusted of 0.8634 and optimized concentrations (CS 3.3% w/v, GA 1.7% v/v, and NaOH 1.3 M) that were conveniently applied with a concentration of CS at 3.0% w/v to decrease the viscosity and facilitate the formation of the beads. In the RB4 dye adsorption design, an adjusted R² (0.8280) with good correlation was observed, where the optimized conditions were: pH = 2, adsorbent dose 0.6 g, and initial concentration of RB4 dye 5 mg/L. The kinetic behavior and the adsorption isotherm allowed us to conclude that the GA-crosslinked CS beads’ adsorption mechanism was controlled mainly by chemisorption interactions, demonstrating its applicability in systems that require the removal of contaminants with similar structures to the model presented.

Pyrazolo[3,4- b ]pyridines derivatives have been synthesized via one-pot condensation of 3-methyl-1-phenyl-1 H -pyrazolo-5-amine ( 1 ), paraformaldehyde ( 2 ) and β-diketones ( 3 ) under microwave irradiation in aqueous media catalyzed by InCl ₃ .

(E)-2-(benzo[d]thiazol-2-yl)-3-heteroarylacrylonitriles are described as a new class of selective inhibitors of acetylcholinesterase (AChE). The most potent compound in the series exhibited good AChE inhibitory activity (IC₅₀ = 64 µM). Compound 7f was found to be more selective than galanthamine in inhibiting AChE and it showed a moderate selectivity index. Kinetic studies on AChE indicated that a competitive type of inhibition pattern exist for these acrylonitrile derivates. Molecular docking models of the ligand-AChE complexes suggest that compound 7g is located on the periphery of the AChE active site.