Adsorption of Methylene Blue and Tetracycline by Zeolites Immobilized on a PBAT Electrospun Membrane.

The detection of emerging contaminants in bodies of water has steadily increased in recent years, becoming a severe problem threatening human and ecosystem health. Developing new materials with adsorption properties to remove these pollutants represents an important step toward a potential solution. In this paper, a polybutylene adipate terephthalate (PBAT) nanofibrous membrane incorporating clinoptilolite zeolite was developed and its excellent performance in removing tetracycline (TC) and methylene blue (MB) from water was demonstrated. The composite membrane was prepared in two steps: firstly, a homogeneous dispersion of clinoptilolite (1 wt% respect to polymer) in a PBAT solution (12.6 wt%) was electrospun; secondly, the electrospun membrane was subjected to an acid treatment that improved its wettability through the protonation of the surface silanol groups of clinoptilolite. The resulting membrane was hydrophilic and showed higher adsorption for TC (800 mg/g) and MB (100 mg/g), using a low dose (90 mg/L) powdered zeolite. The maximum removal capacity was obtained at neutral pH, being the cation exchange reaction the main adsorption mechanism. Pseudo-second-order kinetics and Henry's law agree well with the proposed chemisorption and the high affinity of TC and MB for the adsorbent. The material can be reused after the removal process without generating additional contamination, although losing some effectivity.

Unveiling the Therapeutic Potential of Squalene Synthase: Deciphering Its Biochemical Mechanism, Disease Implications, and Intriguing Ties to Ferroptosis.

Squalene synthase (SQS) has emerged as a promising therapeutic target for various diseases, including cancers, owing to its pivotal role in the mevalonate pathway and the antioxidant properties of squalene. Primarily, SQS orchestrates the head-to-head condensation reaction, catalyzing the fusion of two farnesyl pyrophosphate molecules, leading to the formation of squalene, which has been depicted as a highly effective oxygen-scavenging agent in in vitro studies. Recent studies have depicted this isoprenoid as a protective layer against ferroptosis due to its potential regulation of lipid peroxidation, as well as its protection against oxidative damage. Therefore, beyond its fundamental function, recent investigations have unveiled additional roles for SQS as a regulator of lipid peroxidation and programmed cell death pathways, such as ferroptosis-a type of cell death characterized by elevated levels of lipid peroxide, one of the forms of reactive oxygen species (ROS), and intracellular iron concentration. Notably, thorough explorations have shed light on the distinctive features that set SQS apart from other members within the isoprenoid synthase superfamily. Its unique biochemical structure, intricately intertwined with its reaction mechanism, has garnered significant attention. Moreover, considerable evidence substantiates the significance of SQS in various disease contexts, and its intriguing association with ferroptosis and lipid peroxidation. The objective of this report is to analyze the existing literature comprehensively, corroborating these findings, and provide an up-to-date perspective on the current understanding of SQS as a prospective therapeutic target, as well as its intricate relationship with ferroptosis. This review aims to consolidate the knowledge surrounding SQS, thereby contributing to the broader comprehension of its potential implications in disease management and therapeutic interventions.

Improvement in thallium hydride generation using iodide and Rhodamine B.

A continuous flow hydride generation atomic absorption spectrometry (CF-HG-AAS) system was used to study the enhancement effect of different substances for conventional chemical HG of thallium. At room temperature, the acidified sample solution containing the respective enhancement reagent merged with the aqueous NaBH4 solution. The generated thallium hydride was stripped from the eluent solution by the addition of a nitrogen flow and thereafter the bulk phases were separated in a gas-liquid separator. The main factors under study were concentration and type of enhancement reagent (Te, iodide added as KI, Rhodamine B, malachite green and crystal violet) and acid (HCl, H2SO4 or HNO3). Other parameters affecting the thallium hydride generation, such as: NaBH4 concentration, carrier gas flow rate, length of reaction-mixing coil and reagents flow rates, were studied and optimized. Among the enhancement reagents tested, the combination of Rhodamine B and iodide produced the best results. A linear response was obtained between the detection limit (LOD (3σ)) of 1.5µg L(-1) and 1000µg L(-1). The RSD% (n=10) for a solution containing 15µg L(-1) of Tl was 2.9%. The recoveries of thallium in environmental water samples by spiking the samples with 10 and 20µg L(-1) of Tl were in the 97.0-102.5% range. The accuracy for Tl determination was further confirmed by the analysis of a water standard reference material (1643e form NIST, USA). Finally, it was demonstrated that malachite green and crystal violet showed similar enhancement effect like Rhodamine B for thallium HG.

Desarrollo de un método analítico para la determinación de selenio en huevos fortificados de gallinas (Isa Brown) por espectroscopia de absorción atómica con generación de hidruros / Development of an analytical method for the determination of selenium in fortified hens eggs (Isa Brown) by atomic absorption spectroscopy hydride generation

El huevo es una fuente proteica de uso masivo, en consideración a su bajo costo, es consumido con mayor frecuencia por toda la población. Por esta razón, es de gran interés introducir al mercado un tipo de huevo "saludable", que disminuya los riesgos ligados a enfermedades cardiovasculares y que actúe como antioxidante. Por ello, se evaluó la incorporación del Selenio Orgánico (Sel-Plex®, Alltech Inc) en el programa de alimentación de gallinas ponedoras comerciales raza isa brown con el objeto de obtener huevos fortificados con selenio. Estos fueron evaluados empleando la técnica de espectroscopia analítica con generación de hidruros (HGAAS) y para llevar a cabo la digestión se empleó una mezcla de HNO3/H2O2. El intervalo lineal fue de 6,0 a 200,0 µg/L para el selenio. Con un límite detección de 0,11 µg/L. La precisión de 0,82% y la recuperación de 97-104,4% y una frecuencia de análisis de 24 muestras/hora. La principal ventaja de este método es la determinación de selenio en huevo completo. Los resultados indican que luego de un período de 12 semanas la concentración de selenio es de 62,45 de mg Selenio/huevo lo que muestra que estos proporcionan los requerimientos necesarios. Por lo tanto los huevos enriquecidos en Venezuela contribuirían a mejorar la dieta diaria de estos consumidores.

The egg is a protein source for mass use, considering its low cost, is most commonly consumed by the population. For this reason, it is of great interest to enter the market a type of egg "healthy" to decrease the risks associated with cardiovascular disease and act as an antioxidant. Therefore, it evaluated the incorporation of organic selenium (Sel-Plex ®, Alltech Inc.) in the feeding program commercial layers “Isa Brown” race in order to obtain eggs fortified with selenium. These were assessed using analytical technique spectroscopy with hydride generation (HGAAS) and to conduct the digestion was used a mixture of HNO3/H2O2. The linear range was from 6.0 to 200.0 mg / L for selenium. With detection limit of 0.11 mg / L 0.82% accuracy and recovery of 97 to 104.4% and a frequency analysis of 24 samples / hour. The main advantage of this method is the determination of selenium in whole egg. The results indicate that after a period of 12 weeks the concentration of selenium is 62.45 Selenium mg / egg showing that these provide the necessary requirements. Therefore enriched eggs in Venezuela would help improve the diet of these consumers.