564 research outputs found

    Comments on “Probiotic Bifidobacterium strains and galactooligosaccharides improve intestinal barrier function in obese adults but show no synergism when used together as synbiotics”

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    A finite strain constitutive model to predict a complex elastoplastic deformation behaviour involves very high pressures and shockwaves in orthotropic materials is developed in this work. The important feature of the proposed hyperelastic-plastic constitutive model is a Mandel stress tensor combined with the new generalised orthotropic pressure. The formulation is developed in the isoclinic configuration and allows for a unique treatment for elastic and plastic orthotropy. The elastic orthotropy is taken into account through a stress tensor decomposition combined with the new pressure. A yield surface of Hill’s yield criterion aligned uniquely within the principal stress space is adopted to characterise plastic orthotropy by means of the evolving structural tensors. An isotropic hardening is adopted to define the evolution of plastic orthotropy. The formulation is further combined with a shock equation of state (EOS) and Grady spall failure model to predict shockwave propagation and spall failure in the materials, respectively. The proposed constitutive model is implemented as a new material model in the Lawrence Livermore National Laboratory (LLNL)-DYNA3D code of UTHM’s version. The ability of the newly constitutive model to describe finite strain deformation and shock propagation in orthotropic materials is first investigated against plate impact data of aluminium alloy in the longitudinal and transverse directions before a comparison against plate impact test data of carbon fibre reinforced epoxy composites along the through-thickness direction is finally conducted. A good agreement is obtained in each test

    Copper and Magnesium Deficiency are Associated with Osteoporosis in Southern Gaza Patients

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    Osteoporosis is a common disease in old ages, trace minerals are central components of bone density and hardness. The present study aims to measure copper, magnesium, iron, calcium and phosphorus levels in osteoporotic southern Gaza patients and control groups. A case –control study included 35 osteoporotic patients and 35 controls aged 40-70 years. Copper, magnesium iron, calcium and phosphorus levels were measured in the serum at PalestinianMedical Relieve Society-Gaza by absorption spectrophotometry method-XLFS Kit (Diasys Diagnostic System GmbH). Serum copper and magnesium levels in osteoporotic patients (74.3±9.8μg/dL 1.56±0.18mg/dl) respectively is significantly (p<0.001) lower than control (98.3±15.2μg/dL, 2.06±0.13mg/dl ). The present work indicated a positive correlation between copper and magnesium levels (r=0.627, p<0.00), positive correlation between copper and number of daily meals (r=0.263, p<0.030), and also positive correlation between calcium and daily exercises (r=0.449, p<0.010). In conclusion copper and magnesium levels are significantly lower in postmenopausal women and men with osteoporosis. Optimizing levels of those trace minerals in old people is beneficial in prevention of osteoporosis. Daily exercises and ingestion of food containing trace minerals is highly recommended for this age group

    Effect of Empagliflozin on Thioacetamide-Induced Liver Injury in Rats: Role of AMPK/SIRT-1/HIF-1α Pathway in Halting Liver Fibrosis

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    Hepatic fibrosis causes severe morbidity and death. No viable treatment can repair fibrosis and protect the liver until now. We intended to discover the empagliflozin’s (EMPA) hepatoprotective efficacy in thioacetamide (TAA)-induced hepatotoxicity by targeting AMPK/SIRT-1 activity and reducing HIF-1α. Rats were treated orally with EMPA (3 or 6 mg/kg) with TAA (100 mg/kg, IP) thrice weekly for 6 weeks. EMPA in both doses retracted the serum GGT, ALT, AST, ammonia, triglycerides, total cholesterol, and increased serum albumin. At the same time, EMPA (3 or 6 mg/kg) replenished the hepatic content of GSH, ATP, AMP, AMPK, or SIRT-1 and mitigated the hepatic content of MDA, TNF-α, IL-6, NF-κB, or HIF-1α in a dose-dependent manner. Likewise, hepatic photomicrograph stained with hematoxylin and eosin or Masson trichrome stain of EMPA (3 or 6 mg/kg) revealed marked regression of the hepatotoxic effect of TAA with minimal injury. Similarly, in rats given EMPA (3 or 6 mg/kg), the immunohistochemically of hepatic photomicrograph revealed minimal stain of either α-SMA or caspase-3 compared to the TAA group. Therefore, we concluded that EMPA possessed an antifibrotic effect by targeting AMPK/SIRT-1 activity and inhibiting HIF-1α. The present study provided new insight into a novel treatment of liver fibrosis

    Modeling and control of single-stage quadratic-boost split source inverters

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    This paper aims to develop the recently introduced Spilt-Source Inverter (SSI) topology to improve its boosting characteristics. New SSI topologies with high voltage gain are introduced in this paper. The proposed converters square the basic SSI’s boosting factor by utilizing an additional inductor, capacitor, and two diodes. Thus, the proposed converters are called Quadratic-Boost (or Square-Boost) SSIs (QBIs or SBIs). Four different QBI topologies are presented. One with continuous input current (CC-QBI), and the other draws a discontinuous input current (DC-QBI) but with reduced capacitor voltage stresses. This paper also introduces the small-signal model of the CC-QBI using state variables perturbance. Based on this model, the closed-loop voltage and current control approach of the dc-boosting factor are designed. Moreover, a modified space vector modulation (MSVM) scheme is presented to reduce the input current ripples. To evaluate the performance of the proposed topologies, a comparative study between them and the other counterpart from different perspectives is introduced. It can be found that the CC-QBI topology has superior boosting characteristics when operating with low input voltage compared with their counterparts. It has a higher boosting capability, lower capacitor voltages, and semiconductor stresses, especially when high voltage gains are required. These merits make the proposed topologies convenient to the Photovoltaic and Fuel-Cell systems. Finally, the feasibility of the suggested topology and the introduced mathematical model is verified via simulation and experimental results, which show good accordance with the theoretical analysis. AuthorScopu

    Insulin-Like Growth Factor (IGF) Binding Protein-2, Independently of IGF-1, Induces GLUT-4 Translocation and Glucose Uptake in 3T3-L1 Adipocytes

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    Insulin-like growth factor binding protein-2 (IGFBP-2) is the predominant IGF binding protein produced during adipogenesis and is known to increase the insulin-stimulated glucose uptake (GU) in myotubes. We investigated the IGFBP-2-induced changes in basal and insulin-stimulated GU in adipocytes and the underlying mechanisms. We further determined the role of insulin and IGF-1 receptors in mediating the IGFBP-2 and the impact of IGFBP-2 on the IGF-1-induced GU. Fully differentiated 3T3-L1 adipocytes were treated with IGFBP-2 in the presence and absence of insulin and IGF-1. Insulin, IGF-1, and IGFBP-2 induced a dose-dependent increase in GU. IGFBP-2 increased the insulin-induced GU after long-term incubation. The IGFBP-2-induced impact on GU was neither affected by insulin or IGF-1 receptor blockage nor by insulin receptor knockdown. IGFBP-2 significantly increased the phosphorylation of PI3K, Akt, AMPK, TBC1D1, and PKCζ/λ and induced GLUT-4 translocation. Moreover, inhibition of PI3K and AMPK significantly reduced IGFBP-2-stimulated GU. In conclusion, IGFBP-2 stimulates GU in 3T3-L1 adipocytes through activation of PI3K/Akt, AMPK/TBC1D1, and PI3K/PKCζ/λ/GLUT-4 signaling. The stimulatory effect of IGFBP-2 on GU is independent of its binding to IGF-1 and is possibly not mediated through the insulin or IGF-1 receptor. This study highlights the potential role of IGFBP-2 in glucose metabolism

    Umbelliferone prevents isoproterenol-induced myocardial injury by upregulating Nrf2/HO-1 signaling, and attenuating oxidative stress, inflammation, and cell death in rats

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    The role of oxidative injury and inflammatory response in cardiovascular diseases and heart failure has been well-acknowledged. This study evaluated the protective effect of umbelliferone (UMB), a coumarin with promising radical scavenging and anti-inflammatory activities, on myocardial injury induced by isoproterenol (ISO) in rats. Rats received 50 mg/kg UMB orally for 14 days and 85 mg/kg ISO twice at an interval of 24 h. Administration of ISO elevated serum troponin I, creatine kinase-MB and lactate dehydrogenase, and caused histopathological alterations, including degeneration, fatty vacuolation, myolysis, and atrophy of myocardial fibers. Malondialdehyde (MDA), nitric oxide (NO), nuclear factor-kappaB (NF-κB) p65, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β were increased, whereas reduced glutathione (GSH), superoxide dismutase (SOD), and catalase were decreased in ISO-administered rats. UMB effectively ameliorated myocardial injury, alleviated cardiac function markers, MDA, NO, NF-κB p65, and the inflammatory mediators, and enhanced cellular antioxidants. Bax, caspase-3, and 8-OHdG were decreased, and Bcl-2 was increased in ISO-administered rats treated with UMB. In addition, UMB upregulated nuclear factor-erythroid factor 2-related factor 2 (Nrf2) and heme oxygenase (HO)-1 in the heart of ISO-administered rats. In conclusion, UMB can protect the myocardium from oxidative injury, inflammatory response, and cell death induced by ISO by upregulating Nrf2/HO-1 signaling and antioxidants

    Selective Hydrogenation of Cinnamaldehyde over Salt-Promoted Pd-Based Catalysts

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    Abstract The effect of salt additives (AlCl 3 , SnCl 2 , FeCl 3 ) on the catalytic behavior o

    A New Chaotic System with Line of Equilibria: Dynamics, Passive Control and Circuit Design

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    A new chaotic system with line equilibrium is introduced in this paper. This system consists of five terms with two transcendental nonlinearities and two quadratic nonlinearities. Various tools of dynamical system such as phase portraits, Lyapunov exponents, Kaplan-Yorke dimension, bifurcation diagram and Poincarè map are used. It is interesting that this system has a line of fixed points and can display chaotic attractors. Next, this paper discusses control using passive control method. One example is given to insure the theoretical analysis. Finally, for the  new chaotic system, An electronic circuit for realizing the chaotic system has been implemented. The numerical simulation by using MATLAB 2010 and implementation of circuit simulations by using MultiSIM 10.0 have been performed in this study
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