A pseudo-spectral scheme for systems of two-point boundary value problems with left and right sided fractional derivatives and related integral equations

We target here to solve numerically a class of nonlinear fractional two-point boundary value problems involving left- and right-sided fractional derivatives. The main ingredient of the proposed method is to recast the problem into an equivalent system of weakly singular integral equations. Then, a Legendre-based spectral collocation method is developed for solving the transformed system. Therefore, we can make good use of the advantages of the Gauss quadrature rule. We present the construction and analysis of the collocation method. These results can be indirectly applied to solve fractional optimal control problems by considering the corresponding Euler-Lagrange equations. Two numerical examples are given to confirm the convergence analysis and robustness of the scheme. © 2021 Tech Science Press. All rights reserved.Russian Foundation for Basic Research, РФФИ: 19-01-00019The Russian Foundation for Basic Research (RFBR) Grant No. 19-01-00019

Integral spectral Tchebyshev approach for solving space Riemann-Liouville and Riesz fractional advection-dispersion problems

Abstract The principal aim of this paper is to analyze and implement two numerical algorithms for solving two kinds of space fractional linear advection-dispersion problems. The proposed numerical solutions are spectral and they are built on assuming the approximate solutions to be certain double shifted Tchebyshev basis. The two typical collocation and Petrov-Galerkin spectral methods are applied to obtain the desired numerical solutions. The special feature of the two proposed methods is that their applications enable one to reduce, through integration, the fractional problem under investigation into linear systems of algebraic equations, which can be efficiently solved via any suitable solver. The convergence and error analysis of the double shifted Tchebyshev basis are carefully investigated, aiming to illustrate the correctness and feasibility of the proposed double expansion. Finally, the efficiency, applicability, and high accuracy of the suggested algorithms are demonstrated by presenting some numerical examples accompanied with comparisons with some other existing techniques discussed in the literature

Covid-19 and the central nervous system: what is the interplay?

Since the outbreak of COVID-19 in 2019-2020, the highly contiguous disease caused by coronavirus 2 (SARS-CoV-2) spread worldwide in a short life span causing a disastrous effect and nearly 5.8 million deaths until February 2022. This global health crisis caused concerns about the disease's aetiology, epidemiology, and management. Understanding the virus's long- and short-term consequences on diverse human body organs and systems was one of the scientist's concerns despite the virus' respiratory system principal effect. Thus, after reporting neurological symptoms in approximately one-third of hospitalised patients with COVID-19, demonstrating how COVID-19 infects the central nervous system (CNS), causing neurodegenerative diseases in various patients and how the virus affects CNS function became quintessential. There are various mechanisms for COVID-19 pathophysiology, some implicating the potential virus invasion of the blood-brain barrier (BBB). Trans-synaptic and hematogenous routes are the main routes for the virus to pass through the barrier. Binding to the BBB endothelial cells is causing significant alterations in the permeability and integrity properties of the barrier, which cause an elevation of the incidence rate of neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis among COVI-19 patients. COVID-19 patients developed neurological manifestations ranging from mild symptoms to severe diseases such as headache and loss of smell, encephalitis and CNS-mediated respiratory distress. However, encephalitis is not a common complication, and it has a significant mortality rate in severely ill patients due to the hyperactivation of the host immune response. Although more investigations are needed, severe COVID- 19 patients are considered at a high risk of neurodegenerative disorder as a long-term consequence of SARS-CoV-2 infection

Insights into the Microbiological and Physicochemical Properties of Bio-Frozen Yoghurt Made with Probiotic Strains in Combination with Jerusalem Artichoke Tubers Powder

Frozen yoghurt is a refreshing and nutritious dessert, with or without the flavour that combines the texture of ice cream and yoghurt. Several previous studies have been conducted on Jerusalem artichoke tubers due to their components, which contain inulin compounds and other nutrients with beneficial properties of fresh yoghurt. However, limited studies explored the potential benefits of the addition of Jerusalem artichoke tuber powder as a fat replacer on the physicochemical properties and survival of probiotics in frozen yoghurt. In this respect, the aim of this study was to determine the effect of Jerusalem artichoke tuber powder (JATP) (0, 5, 10, 15, and 20% w/w) of the fat source used in the mix as a fat, and sugar replacer in frozen yoghurt production. The microbiological, physicochemical, textural, and sensory properties of frozen yoghurt were investigated. Samples with JATP contained viable counts of bifidobacterium bifidum BGN4 and Lactobacillus casei Lc-01 of 7 log cfu/g during 90 days of storage, as compared to the control sample. The highest viability of probiotics was obtained in the sample formulated with 10% JATP. The formulation of frozen yoghurt with JATP increased the acidity and enhanced the overrun. Compared with the control sample, the incorporation of JATP into frozen yoghurt increased the melting resistance, overrun, and viscosity of the frozen yoghurt. The addition of JATP up to 10% significantly increased sensory attributes. Collectively, the study concluded that the enrichment of frozen yoghurt with JATP up to 20% will provide consumers with health benefits and could be introduced to markets as functional frozen yoghurt

Tolmetin Sodium Fast Dissolving Tablets for Rheumatoid Arthritis Treatment: Preparation and Optimization Using Box-Behnken Design and Response Surface Methodology

Tolmetin sodium (TLM) is a non-steroidal anti-inflammatory drug (NSAIDs). TLM is used to treat inflammation, skeletal muscle injuries, and discomfort associated with bone disorders. Because of the delayed absorption from the gastro intestinal tract (GIT), the currently available TLM dosage forms have a rather protracted start to the effect, according to pharmacokinetic studies. The aim of this study was to create a combination for TLM fast dissolving tablets (TLM-FDT) that would boost the drug’s bioavailability by increasing pre-gastric absorption. The TLM-FDTs were developed using a Box-Behnken experimental design with varied doses of crospovidone (CP), croscarmellose sodium (CCS) as super-disintegrants, and camphor as a sublimating agent. In addition, the current study used response surface approach to explore the influence of various formulation and process factors on tablet qualities in order to verify an optimized TLM-FDTs formulation. The optimized TLM-FDTs formula was subsequently evaluated for its in vivo anti-inflammatory activity. TLM-FDTs have good friability, disintegration time, drug release, and wetting time, as well as fast disintegration and dissolution behavior. Significant increase in drug bioavailability and reliable anti-inflammatory efficacy were also observed, as evidenced by considerable reductions in paw thickness in rats following carrageenan-induced rat paw edema. For optimizing and analyzing the effect of super-disintegrants and sublimating agents in the TLM-FDTs formula, the three-factor, three-level full factorial design is a suitable tool. TLM-FDTs are a possible drug delivery system for enhancing TLM bioavailability and could be used to treat rheumatoid arthritis

Tailoring of Rosuvastatin Calcium and Atenolol Bilayer Tablets for the Management of Hyperlipidemia Associated with Hypertension: A Preclinical Study

Hyperlipidemia is still the leading cause of heart disease in patients with hypertension. The purpose of this study is to make rosuvastatin calcium (ROS) and atenolol (AT) bilayer tablets to treat coexisting dyslipidemia and hypertension with a single product. ROS was chosen for the immediate-release layer of the constructed tablets, whereas AT was chosen for the sustained-release layer. The solid dispersion of ROS with sorbitol (1:3 w/w) was utilized in the immediate-release layer while hydroxypropyl methylcellulose (HPMC), ethylcellulose (EC), and sodium bicarbonate were incorporated into the floating sustained-release layer. The concentrations of HPMC and EC were optimized by employing 32 full factorial designs to sustain AT release. The bilayer tablets were prepared by the direct compression method. The immediate-release layer revealed that 92.34 ± 2.27% of ROS was released within 60 min at a pH of 1.2. The second sustained-release layer of the bilayer tablets exhibited delayed release of AT (96.65 ± 3.36% within 12 h) under the same conditions. The release of ROS and AT from the prepared tablets was found to obey the non-Fickian diffusion and mixed models (zero-order, Higuchi and Korsmeyer–Peppas), respectively. Preclinical studies using rabbit models investigated the impact of ROS/AT tablets on lipid profiles and blood pressure. A high-fat diet was used to induce obesity in rabbits. Bilayer ROS/AT tablets had a remarkable effect on decreasing the lipid profiles, slowing weight gain, and lowering blood pressure to normal levels when compared to the control group

Population genomic analysis of Aegilops tauschii identifies targets for bread wheat improvement.

Aegilops tauschii, the diploid wild progenitor of the D subgenome of bread wheat, is a reservoir of genetic diversity for improving bread wheat performance and environmental resilience. Here we sequenced 242 Ae. tauschii accessions and compared them to the wheat D subgenome to characterize genomic diversity. We found that a rare lineage of Ae. tauschii geographically restricted to present-day Georgia contributed to the wheat D subgenome in the independent hybridizations that gave rise to modern bread wheat. Through k-mer-based association mapping, we identified discrete genomic regions with candidate genes for disease and pest resistance and demonstrated their functional transfer into wheat by transgenesis and wide crossing, including the generation of a library of hexaploids incorporating diverse Ae. tauschii genomes. Exploiting the genomic diversity of the Ae. tauschii ancestral diploid genome permits rapid trait discovery and functional genetic validation in a hexaploid background amenable to breeding