A Review of the Role of Flavonoids in Peptic Ulcer (2010–2020)

Peptic ulcers are characterized by erosions on the mucosa of the gastrointestinal tract that may reach the muscle layer. Their etiology is multifactorial and occurs when the balance between offensive and protective factors of the mucosa is disturbed. Peptic ulcers represent a global health problem, affecting millions of people worldwide and showing high rates of recurrence. Helicobacter pylori infection and the use of non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most important predisposing factors for the development of peptic ulcers. Therefore, new approaches to complementary treatments are needed to prevent the development of ulcers and their recurrence. Natural products such as medicinal plants and their isolated compounds have been widely used in experimental models of peptic ulcers. Flavonoids are among the molecules of greatest interest in biological assays due to their anti-inflammatory and antioxidant properties. The present study is a literature review of flavonoids that have been reported to show peptic ulcer activity in experimental models. Studies published from January 2010 to January 2020 were selected from reference databases. This review refers to a collection of flavonoids with antiulcer activity in vivo and in vitro models.     

The Cu- and Zn-complex-catalyzed methanolysis of the chemical warfare nerve agents soman,sarin, and VX

The catalytic methanolysis of the chemical warfare nerve agents soman, sarin, and VX was investigated by using Cu or Zn complexes. Although VX withstood decontamination, the decomposition yield being around 96%, the soman and sarin deposited on different surfaces were almost fully destroyed under ambient conditions. The catalytic tests performed on a wide range of contaminated surfaces confirm the activity of the investigated catalytic systems, these complexes being suitable, from an economical point of view, for use in the formulation of a possible decomposition kit with military or civilian applicability.     

A class of Sasakian 5-manifolds

We obtain some general results on Sasakian Lie algebras and prove as a consequence that a (2n + 1)-dimensional nilpotent Lie group admitting left-invariant Sasakian structures is isomorphic to the real Heisenberg group H _{2n + 1}. Furthermore, we classify Sasakian Lie algebras of dimension five and determine which of them carries a Sasakian α-Einstein structure. We show that a five-dimensional solvable Lie group with a left-invariant Sasakian structure and which admits a compact quotient by a discrete subgroup is isomorphic to either H ₅ or a semidirect product ? ? (H ₃ × ?). In particular, the compact quotient is an S ¹-bundle over a four-dimensional Kähler solvmanifold.     

Influence of anabolic steroid treatment associated to physical exercise in the ultrasonic vocalization of rats

Unlike humans, who communicate in frequency bands between 250 Hz and 6 kHz, rats can communicate in frequencies above 18 kHz. Their vocalization types depend on the context and are normally associated to subjective or emotional states. It was reported significant vocal changes due to administration of replacement testosterone in a trained tenor singer with hypogonadism. Speech-Language Pathology clinical practices are being sought by singers who sporadically use anabolic steroids associated with physical exercise. They report difficulties in reaching and keeping high notes, "breakage" in the passage of musical notes and post singing vocal fatigue. Those abnormalities could be raised by the association of anabolic steroids and physical exercise. Thus, in order to verify if this association could promote vocal changes, maximum, minimum and fundamental frequencies and call duration in rats treated with anabolic steroids and physically trained (10 weeks duration) were evaluated. The vocalizations were obtained by handling the animals. At the end of that period, rats treated and trained showed significant decrease in call duration, but not in other parameters. The decrease in call duration could be associated to functional alterations in the vocal folds of treated and trained animals due to a synergism between anabolic steroids and physical training.     

Application of linear regression analysis for iron and copper removal process using natural zeolites

Natural zeolites (zeolitic volcanic tuffs) cropped out from three regions of Transilvania, Vultureni (V), Pagli?a (P) and M?cica? (M), were evaluated in the process of iron (V, P, M) and copper (M) removal from wastewaters. Iron and copper removal process was studied using a fixed bed column, when equilibrium and kinetic data were acquired. Four isotherms, Langmuir, Freundlich, Langmuir?CFreundlich and Redlich?CPeterson, were used to fit the experimental data obtained for each natural zeolite sample. Parameters of the adsorption isotherms were estimated from the experimental equilibrium data using MATLAB. Using these data the best fit with one of the chosen isotherm can be found. Isotherm constants were determined by linear regression analysis of the experimental data. We concluded that the mathematical model based on Freundlich isotherm is the most appropriate to describe the iron and copper exchange on our natural zeolite samples.     

Spectral methods for the equations of classical density-functional theory: relaxation dynamics of microscopic films

We propose a numerical scheme based on the Chebyshev pseudo-spectral collocation method for solving the integral and integro-differential equations of the density-functional theory and its dynamic extension. We demonstrate the exponential convergence of our scheme, which typically requires much fewer discretization points to achieve the same accuracy compared to conventional methods. This discretization scheme can also incorporate the asymptotic behavior of the density, which can be of interest in the investigation of open systems. Our scheme is complemented with a numerical continuation algorithm and an appropriate time stepping algorithm, thus constituting a complete tool for an efficient and accurate calculation of phase diagrams and dynamic phenomena. To illustrate the numerical methodology, we consider an argon-like fluid adsorbed on a Lennard-Jones planar wall. First, we obtain a set of phase diagrams corresponding to the equilibrium adsorption and compare our results obtained from different approximations to the hard sphere part of the free energy functional. Using principles from the theory of sub-critical dynamic phase field models, we formulate the time-dependent equations which describe the evolution of the adsorbed film. Through dynamic considerations we interpret the phase diagrams in terms of their stability. Simulations of various wetting and drying scenarios allow us to rationalize the dynamic behavior of the system and its relation to the equilibrium properties of wetting and drying.     

Density functional theory study of the oxidation reaction in the gas and aqueous phase of allyl methyl disulfide with hydroxyl radical

Structural Chemistry - An in silico analysis of the oxidation mechanism of allyl methyl disulfide (AMDS) by hydroxyl radical was achieved at DFT level using B3LYP, CAM-B3LYP, M06-2X, and BMK...