SRT1720 attenuates obesity and insulin resistance but not liver damage in the offspring due to maternal and postnatal high-fat diet consumption

© 2018 the American Physiological Society. Recent studies indicate that sirtuin-1 (SIRT1), an important metabolic sensor and regulator of life span, plays a mechanistic role in maternal obesity-induced programming of metabolic disorders in the offspring. In this study we investigate whether SIRT1 activation in early childhood can mitigate metabolic disorders due to maternal and postnatal high-fat feeding in mice. Male offspring born to chow-fed (MC) or high fat diet-fed dams (MHF) were weaned onto postnatal chow or high-fat diet and treated with SRT1720 (25 mg/kg ip every 2 days) or vehicle control for 6 wk and examined for metabolic disorders. MHF exacerbated offspring body weight and insulin resistance in the offspring exposed to postnatal HFD (OHF). These metabolic changes were associated with reduced hepatic lipid droplet accumulation but increased plasma levels of alanine aminotransferase (ALT), a marker of liver damage. SRT1720 significantly decreased offspring body weight, adiposity, glucose intolerance, and hyperleptinemia due to OHF and reversed hyperinsulinemia and adipocyte hypertrophy due to the additive effects of MHF. Although SRT1720 suppresses liver lipogenesis, inflammation, and oxidative stress markers, it also reduces antioxidants and increased liver collagen deposition in OHF offspring independent of MHF. Hepatic steatosis was attenuated only in MC/OHF offspring in association with elevated plasma ALT levels. The study suggests that postnatal SRT1720 administration can mitigate obesity and insulin resistance in the offspring due to maternal and postnatal HFD exposure. However, the possibility of liver toxicity needs to be further examined

FXR expression is associated with dysregulated glucose and lipid levels in the offspring kidney induced by maternal obesity

© 2015 Glastras et al. Background: Maternal obesity is associated with dysregulation of glucose and lipid metabolism with consequent exposure of the fetus to an abnormal metabolic milieu. It is recognized that maternal obesity predisposes offspring to chronic kidney disease (CKD). We aimed to determine whether the nuclear Farnesoid X receptor (FXR), known to play a role in maintaining homeostasis of glucose and lipid metabolism, is involved in renal injury in offspring of obese mothers. Methods: Maternal obesity was established in a rat model by feeding dams with high-fat diet prior to and during pregnancy and lactation. The offspring's kidneys were examined at postnatal Day 1and Day 20. Human kidney 2 (HK2) cells were exposed to high glucose with or without the FXR agonist GW4064 or when FXR mRNA was silenced. Results: Glucose intolerance in the offspring of obese mothers was evident at weaning, with associated downregulation of renal FXR expression and upregulation of monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-β1 (TGF-β1). HK2 cells exposed to high glucose had reduced FXR expression and increased MCP-1, TGF-β1, fibronectin and collagen IV expression, which was reversed in the presence of GW4064. FXR-silenced HK2 cells had amplified pro-inflammatory and pro-fibrotic markers under high glucose conditions. Conclusions: Maternal obesity influences renal expression of pro-inflammatory and fibrotic factors that predispose the offspring to CKD. This was associated with the downregulation of the renal FXR expression suggesting a potential protective role for FXR

Maternal L-carnitine supplementation ameliorates renal underdevelopment and epigenetic changes in male mice offspring due to maternal smoking

© 2018 John Wiley & Sons Australia, Ltd Objectives: Epidemiological and animal studies showed that L-carnitine (LC) supplementation can ameliorate oxidative stress-induced tissues damage. We have previously shown that maternal cigarette smoke exposure (SE) can increase renal oxidative stress in newborn offspring with postnatal kidney underdevelopment and renal dysfunction in adulthood, which were normalised by LC administration in the SE dams during pregnancy. Exposure to an adverse intrauterine environment may lead to alteration in the epigenome, a mechanism by which adverse prenatal conditions increase the susceptibility to chronic disease later in life. The current study aimed to determine whether maternal SE induces epigenetic changes in the offspring's kidney are associated with renal underdevelopment, and the protective effect of maternal LC supplementation. Method: Female Balb/c mice (7 weeks) were exposed to cigarette smoke (SE) or air (Sham) for 6 weeks prior to mating, during gestation and lactation. A subgroup of the SE dams received LC via drinking water (SE + LC, 1.5 mmol/L) throughout gestation and lactation. Male offspring were studied at postnatal day (P)1, P20, and 13 weeks. Results: Maternal SE altered the expression of renal development markers glial cell line-derived neurotrophic factor and fibroblast growth factor 2, which were associated with increased renal global DNA methylation and DNA methyltransferase 1 mRNA expression at birth. These disorders were reversed by maternal LC administration. Conclusion: The effect of maternal SE on renal underdevelopment involves global epigenetic alterations from birth, which can be prevented by maternal LC supplementation

A two-grid temporal second-order scheme for the two-dimensional nonlinear Volterra integro-differential equation with weakly singular kernel

A two-grid temporal second-order scheme for the two-dimensional nonlinear Volterra integro-differential equation with a weakly singular kernel is of concern in this paper. The scheme is targeted to reduce the computation time and to improve the accuracy of the scheme developed by Xu et al. (Appl Numer Math 152:169–184, 2020). The constructed scheme is armed by three steps: First, a small nonlinear system is solved on the coarse grid using a fix-point iteration. Second, Lagrange’s linear interpolation formula is used to arrive at some auxiliary values for the analysis of the fine grid. Finally, a linearized Crank–Nicolson finite difference system is solved on the fine grid. Moreover, the algorithm uses a central difference approximation for the spatial derivatives. In the time direction, the time derivative and integral term are approximated by the Crank–Nicolson technique and product integral rule, respectively. By means of the discrete energy method, stability and space-time second-order convergence of the proposed approach are obtained in L2-norm. Finally, the numerical verification is fulfilled as the numerical results of the given numerical experiments agree with the theoretical analysis and verify the effectiveness of the algorithm. © 2023, The Author(s) under exclusive licence to Istituto di Informatica e Telematica (IIT).CX20220454; Russian Science Foundation, RSF: 22-21-00075The authors are grateful for helpful comments and suggestions from the reviewers. This work was supported by Postgraduate Scientific Research Innovation Project of Hunan Province (No. CX20220454). Ahmed S. Hendy wishes to acknowledge the support of the RSF grant, project 22-21-00075

Numerical Reconstruction of a Space-Dependent Reaction Coefficient and Initial Condition for a Multidimensional Wave Equation with Interior Degeneracy

A simultaneous reconstruction of the initial condition and the space-dependent reaction coefficient in a multidimensional hyperbolic partial differential equation with interior degeneracy is of concern. A temporal integral observation is utilized to achieve that purpose. The well-posedness, existence, and uniqueness of the inverse problem under consideration are discussed. The inverse problem can be reformulated as a least squares minimization and the Fréchet gradients are determined, using the adjoint and sensitivity problems. Finally, an iterative construction procedure is developed by employing the conjugate gradient algorithm while invoking the discrepancy principle as a stopping criterion. Some numerical experiments are given to ensure the performance of the reconstruction scheme in one and two dimensions. © 2023 by the authors.Russian Science Foundation, RSF: 22-21-00075Ahmed Hendy wishes to acknowledge the RSF, Russia grant, project 22-21-00075

Numerical Simulation for a Multidimensional Fourth-Order Nonlinear Fractional Subdiffusion Model with Time Delay

The purpose of this paper is to develop a numerical scheme for the two-dimensional fourth-order fractional subdiffusion equation with variable coefficients and delay. Using the L2 − 1σ approximation of the time Caputo derivative, a finite difference method with second-order accuracy in the temporal direction is achieved. The novelty of this paper is to introduce a numerical scheme for the problem under consideration with variable coefficients, nonlinear source term, and delay time constant. The numerical results show that the global convergence orders for spatial and time dimensions are approximately fourth order in space and second-order in time. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: M.A.Z. wishes to acknowledge the support of Nazarbayev University Program 091019CRP2120 and the partial support of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant “Dynamical Analysis and Synchronization of Complex Neural Networks with Its Applications”). M.A.Z. wishes also to acknowledge the financial support of the National Research Centre of Egypt (NRC)

New recursive approximations for variable-order fractional operators with applications

To broaden the range of applicability of variable-order fractional differential models, reliable numerical approaches are needed to solve the model equation.In this paper, we develop Laguerre spectral collocation methods for solving variable-order fractional initial value problems on the half line. Specifically, we derive three-term recurrence relations to efficiently calculate the variable-order fractional integrals and derivatives of the modified generalized Laguerre polynomials, which lead to the corresponding fractional differentiation matrices that will be used to construct the collocation methods. Comparison with other existing methods shows the superior accuracy of the proposed spectral collocation methods

NUMERICAL RECONSTRUCTION OF A SPACE-DEPENDENT SOURCE TERM FOR MULTIDIMENSIONAL SPACE-TIME FRACTIONAL DIFFUSION EQUATIONS

In this paper, we consider the problem of identifying the unknown source function in the time-space fractional diffusion equation from the final observation data. An implicit difference technique is proposed in conjunction with the matrix transfer scheme for approximating the solution of the direct problem. The challenge pertains to an inverse scenario encompassing a nonlocal ill-posed operator. The problem under investigation is formulated as a regularized optimization problem with a least-squares cost function minimization objective. An approximation for the source function is obtained using an iterative non-stationary Tikhonov regularization approach. Three numerical examples are reported to verify the efficiency of the proposed schemes. © 2023, Publishing House of the Romanian Academy. All rights reserved.Deanship of Scientific Research, Imam Mohammed Ibn Saud Islamic University: IMSIU-RP23095Acknowledgements. This work was supported and funded by the Deanship of Scientific Research at Imam Mohammad Ibn Saud Islamic University (IMSIU) (grant number IMSIU-RP23095)

The impact of memory effect on space fractional strong quantum couplers with tunable decay behavior and its numerical simulation

The nontrivial behavior of wave packets in the space fractional coupled nonlinear Schrödinger equation has received considerable theoretical attention. The difficulty comes from the fact that the Riesz fractional derivative is inherently a prehistorical operator. In contrast, nonlinear Schrödinger equation with both time and space nonlocal operators, which is the cornerstone in the modeling of a new type of fractional quantum couplers, is still in high demand of attention. This paper is devoted to numerically study the propagation of solitons through a new type of quantum couplers which can be called time-space fractional quantum couplers. The numerical methodology is based on the finite-difference/Galerkin Legendre spectral method with an easy to implement numerical algorithm. The time-fractional derivative is considered to describe the decay behavior and the nonlocal memory of the model. We conduct numerical simulations to observe the performance of the tunable decay and the sharpness behavior of the time-space fractional strongly coupled nonlinear Schrödinger model as well as the performance of the numerical algorithm. Numerical simulations show that the time and space fractional-order operators control the decay behavior or the memory and the sharpness of the interface and undergo a seamless transition of the fractional-order parameters. © 2021, The Author(s).This study was supported financially by RFBR Grant (19-01-00019), the National Research Centre of Egypt (NRC) and Ghent university

Electroosmotically induced peristaltic flow of a hybrid nanofluid in asymmetric channel: Revolutionizing nanofluid engineering

The exploration of electroosmotic peristaltic flow in asymmetric channels using hybrid non-Newtonian nanofluids holds significant promise across multiple domains. From microfluidics and electronics cooling to energy systems and biomedical applications, its implications are vast. By leveraging the distinctive attributes of nanofluids and the precision offered by electroosmotic and peristaltic flow, this research has the potential to drive the development of more efficient and innovative designs in these diverse fields. The current investigation reveals an analysis of heat transfer concerning hybrid nano liquid based on water. This nano liquid is influenced by both electroosmosis and peristalsis, operating simultaneously. Within this water-based hybrid nanofluid, there are nanoparticles composed of copper and iron oxide (Fe2O3−Cu/H2O). The study investigates into characteristics of flow and heat transport processes, considering key factors such as the applied electric and magnetic fields, thermal conductivity, mixed convection, shape of nanoparticles, variable viscosity, and assumptions related to Ohmic heating. Thermal and velocity slip boundary conditions are considered. To handle the analysis, the Poisson-Boltzmann equation is approximated using the Debye-Hückel approximation. The governing equations are then simplified using lubrication approximation. To solve the resulting system of dimensionless differential equations, NDSolve build in command of computational package Mathematica is employed. The outcomes of study affirm that inclusion of nanomaterials plays a vital role in enhancing heat transfer processes. Specifically, an increase in Joule heating and electromagnetic parameters contributes to a higher heat transfer rate at the boundary. Additionally, the incorporation of nanomaterials leads to a decrease in the flow rate of the nanofluid due to an increase in Helmholtz-Smoluchowski velocity. Furthermore, the heat transfer rate at wall diminishes as the Hartman number and Helmholtz-Smoluchowski velocity are increased. Showcasing the potential to enhance heat transfer, microfluidic devices, and various systems by harnessing the distinctive characteristics of hybrid nanofluids and regulating flow through peristaltic and electroosmotic methods. Providing insights into potential applications and industries that could profit from these findings, including microfluidics, electronics cooling, biomedical devices, and energy systems. © 2023 The Authors21498; 202104010911016, 22088; BK20200429; King Khalid University, KKU: RGP.1/435/44; Deanship of Scientific Research, King Saud University; 2023-JC-YB-375, 22040The authors are thankful to the Deanship of Scientific Research, King Khalid University, Abha, Saudi Arabia, for financially supporting this work through the General Research Project under Grant No: RGP.1/435/44 and The science and technology project of Jiangsu: BK20200429; the science and technology project of Shanxi Province: 2023-JC-YB-375; China TIESIJU Civil Engineering Group Co. Ltd: 22040; China Design Group Co. Ltd: 21498; Nanjing Huizhu Information Technology Research Institute Co. Ltd: 22088; Suzhou Rail Transit, Shanxi Technology Innovation Center project: 202104010911016.The authors are thankful to the Deanship of Scientific Research, King Khalid University , Abha, Saudi Arabia, for financially supporting this work through the General Research Project under Grant No: RGP.1/435/44 and The science and technology project of Jiangsu : BK20200429 ; the science and technology project of Shanxi Province : 2023-JC-YB-375 ; China TIESIJU Civil Engineering Group Co., Ltd : 22040 ; China Design Group Co., Ltd : 21498 ; Nanjing Huizhu Information Technology Research Institute Co., Ltd : 22088 ; Suzhou Rail Transit, Shanxi Technology Innovation Center project : 202104010911016