A meshless point collocation method for 2-D multi-term time fractional diffusion-wave equation

In this paper, a meshless collocation method is considered to solve the multi-term time fractional diffusion-wave equation in two dimensions. The moving least squares reproducing kernel particle approximation is employed to construct the shape functions for spatial approximation. Also, the Caputo’s time fractional derivatives are approximated by a scheme of order O(τ ^3?α ), 1< α < 2. Stability and convergence of the proposed scheme are discussed. Some numerical examples are given to confirm the efficiency and reliability of the proposed method.     

Synthesis of Novel 3-(5-(Alkyl/arylthio)-1,3,4-Oxadiazol-2-yl)-8-Phenylquinolin-4(1H)-One Derivatives as Anti-HIV Agents

Novel quinolone derivatives featuring an 1,3,4-oxadiazole ring as a metal-chelating component and a benzyl group base on HIV-1 integrase inhibitors pharmacophore were designed and synthesized. An antiviral assay revealed that most analogues inhibited HIV-1 replication in the cell culture. Our results showed that compounds bearing small alkyl groups as R group were inactive in anti-HIV-1 assay, whereas compounds possessing benzyl or substituted benzyl at the same position showed good anti-HIV activity with the range of 20–57% at 100 μM concentration. Among them, 3-(5-((2-fluorobenzyl)thio)-1,3,4-oxadiazol-2-yl)-8-phenylquinolin-4-(1H)-one (compound 13) showed reasonable cell-based antiviral activity (EC₅₀ = 50 μM) with no considerable cytotoxicity (CC₅₀ > 100 μM) in the cell viability assay, suggesting that it may be amenable to further development for identifying new anti-HIV-1 agents. Docking studies using the later crystallographic data available for PFV integrase corroborate favorable binding to the active site of HIV integrase, providing a basis for the design of more potent analogues.     

C-20 ketone reduction of hydrocortisone by rice field microalga <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> MCCS 013

A unicellular microalga, Chlorella vulgaris, was isolated from rice field and applied in the biotransformation experiment of hydrocortisone (1). This strain has not been previously tested for hydrocortisone bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25°C for 14 days incubation. The products obtained were chromatographically purified followed by their characterization using spectroscopic methods. 11β,17α,20β,21-Tetrahydroxypregn-4-en-3-one (2), 11β,17β-dihydroxyandrost-4-en-3-one (3), and 11β-hydroxyandrost-4-ene-3,17-dione (4) were the main bioproducts in the hydrocortisone bioconversion. Bioreaction characteristics observed were 20-ketone reduction for accumulation of compound 2 and side chain degradation of the substrate to prepare compounds 3 and 4. Time course study showed the accumulation of the product 2 from the second day of the fermentation and 3 as well as 4 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of six strains of Chlorella vulgaris.     

A method based on meshless approach for the numerical solution of the two‐space dimensional hyperbolic telegraph equation

In the current article, we investigate the RBF solution of second‐order two‐space dimensional linear hyperbolic telegraph equation. For this purpose, we use a combination of boundary knot method (BKM) and analog equation method (AEM). The BKM is a meshfree, boundary‐only and integration‐free technique. The BKM is an alternative to the method of fundamental solution to avoid the fictitious boundary and to deal with low accuracy, singular integration and mesh generation. Also, on the basis of the AEM, the governing operator is substituted by an equivalent nonhomogeneous linear one with known fundamental solution under the same boundary conditions. Finally, several numerical results and discussions are demonstrated to show the accuracy and efficiency of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.     

A meshless based numerical technique for traveling solitary wave solution of Boussinesq equation

In this paper, we employ the boundary-only meshfree method to find out numerical solution of the classical Boussinesq equation in one dimension. The proposed method in the current paper is a combination of boundary knot method and meshless analog equation method. The boundary knot technique is an integration free, boundary-only, meshless method which is used to avoid the known disadvantages of the method of fundamental solution. Also, we use the meshless analog equation method to replace the nonlinear governing equation with an equivalent nonhomogeneous linear equation. A predictor-corrector scheme is proposed to solve the resulted differential equation of the collocation. The numerical results and conclusions are obtained for both the ‘good’ and the ‘bad’ Boussinesq equations.     

The numerical solution of the non-linear integro-differential equations based on the meshless method

This article investigates the numerical solution of the nonlinear integro-differential equations. The numerical scheme developed in the current paper is based on the moving least square method. The moving least square methodology is an effective technique for the approximation of an unknown function by using a set of disordered data. It consists of a local weighted least square fitting, valid on a small neighborhood of a point and only based on the information provided by its n closet points. Hence the method is a meshless method and does not need any background mesh or cell structures. The error analysis of the proposed method is provided. The validity and efficiency of the new method are demonstrated through several tests.     

Compression ratio energy and exergy analysis of a developed Brayton-based power cycle employing CAES and ORC

Journal of Thermal Analysis and Calorimetry - Energy consumption growth in the world is one of the primary concerns of researchers in the energy fields. Providing demanded power, especially in peak...     

Hydrazine trapping ability of Si12C12 fullerene-like nanoclusters: a DFT study

Structural Chemistry - In this study, the nondissociative hydrazine (N2H4) adsorption on the surface of Si12C12 nanoclusters have been investigated using density functional theory at...     

Expression of miRNAs Targeting <Emphasis Type="Italic">mTOR</Emphasis> and <Emphasis Type="Italic">S6K1</Emphasis> Genes of mTOR Signaling Pathway Including miR-96, miR-557, and miR-3182 in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer. Aberrant expression of genes in mTOR pathway and their targeting miRNAs plays an important role in TNBC. The aim of this study was to determine the expression of mTOR and S6K1 and their targeting miRNAs in breast cancer cell lines and clinical samples. miRNAs targeting 3′-UTR of mTOR and S6K1 mRNAs were predicted using bioinformatic algorithms. MDA-MB-231, MCF-7, and MCF-10A as well as 20 TNBC samples were analyzed for gene and miRNA expression using quantitative real-time PCR (RT-qPCR). A receiver operating characteristic (ROC) curve analysis was performed for evaluation of candidate miRNAs as diagnostic biomarkers. miR-96 and miR-557 targeting mTOR and S6K1 mRNAs, respectively, were selected, and miR-3182 was selected as the miRNA targeting both genes. The miRNAs were down-regulated in cell lines, while their target mRNAs were up-regulated. Similar findings were observed in clinical samples. The ROC curve analysis revealed decline in expression of these miRNAs. We suggest that miR-96, miR-557, and miR-3182 can be used as inhibitory agents for mTOR and S6K1 in TNBC-targeted therapy.     

Polynomial and nonpolynomial spline methods for fractional sub-diffusion equations

We consider one-dimensional fractional sub-diffusion equations on an unbounded domain. For a problem of this type for which an exact or approximate artificial boundary condition is available we reduce it to an initial-boundary value problem on a bounded domain. We then analyze the numerical solution of the problem by polynomial and nonpolynomial spline methods. The consistency and the Von Neumann stability analysis of these methods are also discussed. Numerical experiments clarify the effectiveness and order of accuracy of the proposed methods.