Search

Mercury (Hg) is a widespread environmental pollutant and toxicant that induces multiple organ damage in humans and animals. Hg toxicity is mediated by the induction of oxidative stress in the target cells. We used uric acid (UA), a potent antioxidant found in biological fluids, to protect human red blood cells (RBC) and lymphocytes against Hg-mediated cell, organelle, and genotoxicity. RBCs were incubated with mercuric chloride (Hg[Cl.sub.2]), an Hg(II) compound, either alone or in the presence of UA. Incubation of RBCs with only Hg[Cl.sub.2] increased the production of nitrogen and oxygen radical species, enhanced methemoglobin levels, heme degradation, free ferrous iron, oxidation of proteins and membrane lipids, and reduced the antioxidant capacity of cells. UA enhanced the antioxidant capacity of RBCs and restored metabolic, plasma membrane-bound, and antioxidant enzyme activities. Scanning electron microscopy showed that UA prevented Hg[Cl.sub.2]-mediated morphological changes in RBCs. Hg[Cl.sub.2] dissipated the mitochondrial membrane potential and increased lysosomal membrane damage in lymphocytes, but UA pre-treatment attenuated these effects. Genotoxicity analysis by comet assay showed that UA protected lymphocyte DNA from Hg[Cl.sub.2]-induced damage. Importantly, UA itself did not exhibit any deleterious effects on RBCs or lymphocytes. Thus, UA protects human blood cells from Hg(II)-mediated oxidative damage, reducing the harmful effects of this extremely toxic metal. We suggest that UA has a similar protective role in plasma against heavy metal toxicity. Key words: mercury, uric acid, oxidative stress, red blood cells, antioxidant, DNA damage, lymphocytes. Le mercure (Hg) est un polluant et un agent toxique environnemental repandu qui induit des dommages organiques multiples chez les humains et les animaux. La toxicite du Hg est mediee par l'induction d'un stress oxydant dans les cellules cibles. Les auteurs ont utilise l'acide urique (AU), un puissant antioxydant present dans les liquides biologiques, pour proteger les globules rouges (GR) et les lymphocytes humains contre la toxicite cellulaire, aux organites et genique mediee par le Hg. Les GR ont ete incubes avec du Hg[Cl.sub.2], un compose Hg(II), soit seul, soit en presence d'AU. L'incubation des GR avec le Hg[Cl.sub.2] seul augmentait la production de derives reactifs d'azote et d'oxygene, augmentait les niveaux de methemoglobine, la degradation de l'heme, le fer ferreux libre, l'oxydation des proteines et des lipides membranaires et reduisait la capacite antioxydante des cellules. L'AU accroissait la capacite antioxydante des globules rouges et retablissait les activites enzymatiques metaboliques, liees a la membrane plasmique et antioxydantes. La microscopie electronique a balayage montrait que l'AU prevenait les modifications morphologiques des GR causees par le Hg[Cl.sub.2]. Le Hg[Cl.sub.2] dissipait le potentiel de la membrane mitochondriale et augmentait les dommages dela membrane lysosomale dans les lymphocytes, mais le pretraitement a l'AU attenuait ces effets. L'analysedelagenotoxicite par le test des cometes montrait que l'AU protegeait l'ADN des lymphocytes des dommages induits par le Hg[Cl.sub.2]. Il est important de noter que l'AU lui-meme n'exercait pas d'effets nocifs sur les GR ou les lymphocytes. Ainsi, l'AU protege les cellules sanguines humaines des dommages oxydants causes par le Hg(II), reduisant ainsi les effets nocifs de ce metal extremement toxique. Les auteurs suggerent que l'AU joue un role protecteur similaire dans le plasma contre la toxicite des metaux lourds. [Traduit par la Redaction] Mots-cles: mercure, acide urique, stress oxydant, globules rouges, antioxydant, dommages a l'ADN, lymphocytes., Introduction Mercury (Hg) is a heavy metal that is widely dispersed in nature (Pirrone et al. 2010). Hg and its compounds have applications in chemical laboratories, hospitals, dental clinics, and [...]

This paper conducts an extensive comparative analysis of numerical methods employed in modeling blood flow through arteries with Magnetohydrodynamics (MHD) and hybrid nanofluids. The study investigates the effectiveness and precision of distinct numerical approaches: Akbari Ganji's Method (AGM), Fourth-Order Runge–Kutta (RK4), Finite Volume Method (FVM), and the Finite Element Method (FEM). These methods are essential for comprehending the intricate fluid dynamics that arise in the presence of magnetic fields and hybrid nanofluids a phenomenon relevant in numerous medical applications. Blood flow is subjected to a homogeneous magnetic field in a radial direction while the magneto-hemodynamics effect is taken into account. A variety of medical, physiological, and surgical procedures, as well as the regulation of blood pressure, heat distribution, wound healing, diagnostic imaging, and drug discovery, depend on blood flow through arteries to carry out vital functions such as oxygen and nutrition delivery, organ maintenance, and wound healing. Our findings highlight that while each method has strengths, their applicability varies based on the problem's characteristics and computational resource constraints. This analysis aids researchers and practitioners in selecting the most suitable method for their modeling requirements, advancing numerical techniques for complex fluid dynamics involving MHD and hybrid nanofluids. [ABSTRACT FROM AUTHOR]

A new area of applied chemistry called chemical graph theory uses combinatorial techniques to explain the complex interactions between atoms and bonds in chemical systems. This work investigates the use of edge partitions to decipher molecular connection patterns. The main goal is to use topological indices that capture important topological features to create a connection between the thermodynamic properties and structural characteristics of chemical molecules. We specifically examine the complex web of atoms and links that make up the Fe phthalocyanine chemical graph. Moreover, our study demonstrates a relationship between the calculated topological indices and the thermodynamic properties of Fe phthalocyanine (Phthalocyanine Iron (II)). This work offers insight into the thermodynamic consequences of molecule structures. It advances the subject of chemical graph theory, providing a useful perspective for future applications in catalysis and materials science. [ABSTRACT FROM AUTHOR]

This paper introduces a groundbreaking method, Homotopy-based Fourier transform, integrating Fourier transform and Homotopy perturbation for refined nonlinear problem-solving. The modification enhances solution technique efficiency, notably accelerating convergence, particularly in solving the Korteweg–de Vries equation. Demonstrating versatility, the method effectively addresses ordinary and partial differential equations, showcasing its applicability across diverse mathematical scenarios. Moreover, the approach is extended to nonlinear dynamical systems, illustrating its robustness in handling complex dynamic behaviors. This method proves especially suitable for highly nonlinear differential equations, offering an efficient and effective tool for scientists and engineers dealing with intricate mathematical models. By significantly improving convergence rates, the Homotopy-based Fourier transform stands out as a valuable asset in unraveling the complexities of nonlinear systems across various scientific and engineering applications. [ABSTRACT FROM AUTHOR]

In this analysis, the solutions of the Linear and Non-Linear models are explored and compared using two distinct methods: the Finite Difference Method (FDM) and the Physics-Informed Neural Networks (PINNs). Initially, the solution is derived employing the principles of FDM, followed by solving the same problem using the methodology of PINNs. Subsequently, a comparative examination of the solution graphs with the exact solution is conducted. [ABSTRACT FROM AUTHOR]

The adoption of green chemistry protocols in nanoparticle (NP) synthesis has exhibited substantial potential and is presently a central focus in research for generating versatile NPs applicable across a broad spectrum of applications. In this scientific contribution, we, for the first time, examined the ability of Aconitum Laeve (A. Laeve) crude extract to synthesize silver and gold nanoparticles (AgNPs@AL; AuNP@AL) and explored their potential applications in biological activities and the catalytic degradation of environmental pollutants. The synthesized NPs exhibited a distinctive surface plasmon resonance pattern, a spherical morphology with approximate sizes of 5–10 nm (TEM imaging), a crystalline architecture (XRD analysis), and potential functional groups identified by FTIR spectroscopy. The antibacterial activity was demonstrated by inhibition zones that measured 16 and 14 mm for the AgNPs@AL and AuNP@AL at a concentration of 80 µg/mL against Staphylococcus aureus and 14 and 12 mm against Escherichia coli, respectively. The antioxidant potential of the synthesized NPs was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO), and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Our findings suggest that the AuNP@AL effectively countered the tested radicals considerably, displaying IC50 values of 115.9, 103.54, and 180.85 µg/mL against DPPH, PTIO, and ABTS, respectively. In contrast, the AgNPs@AL showed IC50 values of 144.9, 116.36, and 95.39 µg/mL against the respective radicals. In addition, both the NPs presented significant effectiveness in the photocatalytic degradation of methylene blue and rhodamine B. The overall observations indicate that A. Laeve possesses a robust capability to synthesize spherical nanoparticles, exhibiting excellent dispersion and showcasing potential applications in both biological activities and environmental remediation. [ABSTRACT FROM AUTHOR]