Caffeic Acid Phenethyl Ester: A Review of Its Antioxidant Activity,Protective Effects against Ischemia-reperfusion Injury and Drug Adverse Reactions

Propolis, a honey bee product, has been used in folk medicine for centuries for the treatment of abscesses, canker sores and for wound healing. Caffeic acid phenethyl ester (CAPE) is one of the most extensively investigated active components of propolis which possess many biological activities, including antibacterial, antiviral, antioxidant, anti-inflammatory, and anti-cancer effects. CAPE is a polyphenolic compound characterized by potent antioxidant and cytoprotective activities and protective effects against ischemia–reperfusion (I/R)-induced injury in multiple tissues such as brain, retina, heart, skeletal muscles, testis, ovaries, intestine, colon, and liver. Furthermore, several studies indicated the protective effects of CAPE against chemotherapy-induced adverse drug reactions (ADRs) including several antibiotics (streptomycin, vancomycin, isoniazid, ethambutol) and chemotherapeutic agents (mitomycin, doxorubicin, cisplatin, methotrexate). Due to the broad spectrum of pharmacological activities of CAPE, this review makes a special focus on the recently published data about CAPE antioxidant activity as well as its protective effects against I/R-induced injury and many adverse drug reactions.     

Thermal Conductivity in Nanocrystalline Ceria Thin Films

The thermal conductivity of nanocrystalline ceria films grown by unbalanced magnetron sputtering is determined as a function of temperature using laser‐based modulated thermoreflectance. The films exhibit significantly reduced conductivity compared with stoichiometric bulk CeO₂. A variety of microstructure imaging techniques including X‐ray diffraction, scanning and transmission electron microscopy, X‐ray photoelectron analysis, and electron energy loss spectroscopy indicate that the thermal conductivity is influenced by grain boundaries, dislocations, and oxygen vacancies. The temperature dependence of the thermal conductivity is analyzed using an analytical solution of the Boltzmann transport equation. The conclusion of this study is that oxygen vacancies pose a smaller impediment to thermal transport when they segregate along grain boundaries.     

Organotin polymers XIV. Synthesis and copolymerization reactions of p-acryloyloxy-tri-n-butyltin benzoate with some vinyl monomers

p-Acryloyloxy-tri-n-butyltin benzoate (ABTB) was prepared by the reaction of p-hydroxy-tri-n-butyltin benzoate and acrylic acid in the presence of dicyclohexylcarbodiimide. The monomer reactivity ratios for the copolymerizations of ABTB (M₁) with methyl acrylate (M₂), ethyl acrylate (M₂), n-butyl acrylate (M₂), methyl methacrylate (M₂), styrene (M₂) and acrylonitrile (M₂) have been found to be r₁ = 0.080, r₂ = 1.046; r₁ = 0.039, r₂ = 1.585; r₁ = 0.019, r₂ = 2.076; r₁ = 0.150, r₂ = 1.710; r₁ = 0.113, r₂ = 1.339 and r₁ = 0.007, r₂ = 2.853, respectively. The Q and e values for the prepared organotin monomer were calculated. Copolymerization reactions were carried out in solution at 70°C using 1 mol-% azobisisobutyronitrile. The structure of the ABTB monomer and the prepared copolymers was investigated by IR and ¹H-NMR spectroscopy.     

Organotin polymers—XVII. Azeotropy in terpolymerization reactions of tri-n-butyltin 4-acryloyloxybenzoate wit alkyl acrylates or styrene and acrylonitrile

Ternary copolymerizations of tri-n-butyltin 4-acryloyloxybenzoate (ABTB) with acrylonitrile (AN) and alkyl acrylates [methyl (MA), ethyl (EA) or butyl acrylate (BA)], methyl methacrylate (MMA) or styrene (ST) were carried out in solution at 70°C in the presence of free radical initiator. Experimental terpolymerization data agreed well with calculations based on the Alfrey-Goldfinger equation. The determination of unitary, binary and ternary azeotropies of various systems studied was easily handled by a computer program. The results obtained show that there is no ternary azeotropic composition for any terpolymer, system studied. Selective unitary and binary azeotropic compositions were polymerized and the results obtained show good agreement between the theoretical and experimental terpolymer composition for each case.     

Influence of Mo or Cu doping in Fe/MgO catalyst for synthesis of single-walled carbon nanotubes by catalytic chemical vapor deposition of methane

A series of mono-, bi- or tri-metallic Fe–Mo-Cu/MgO catalysts with the same metal loading of 6 wt% were prepared by impregnation method and used as catalysts for synthesis single-walled carbon nanotubes (SWCNTs) via methane decomposition. XRD, H₂-TPR, and nitrogen physisorption techniques were used to characterize the freshly calcined catalysts, while HRTEM, Raman spectroscopy and TGA were employed to investigate the morphology and microstructure of the SWCNTs product. The obtained results indicated that the introduction of Mo or Cu in the Fe/MgO catalyst enhanced the catalytic growth activity. TEM images showed that both bundles and isolated SWCNTs were obtained over Mo containing catalysts, whereas only SWCNTs bundles were grown over the Fe-Cu/MgO catalyst. The obtained SWCNTs having a diameter of around 0.9–2.4 nm. Raman analysis illustrated that all promoted catalysts produced high quality of SWCNTs compared to the unpromoted Fe/MgO catalyst.     

Structure,morphology, optical and magnetic studies of Fe3O4-doped CdS nanocomposite

Journal of Materials Science: Materials in Electronics - The possibility to integrate the different nanomaterials offers a perfect chance to obtain new nanocomposites with new features...     

High performance decoupled active and reactive power control for three-phase grid-tied inverters using model predictive control

Finite control set-model predictive control (FCS-MPC) is employed in this paper to control the operation of a three-phase grid-connected string inverter based on a direct PQ control scheme. The main objective is to achieve high-performance decoupled control of the active and reactive powers injected to the grid from distributed energy resources (DER). The FCS-MPC scheme instantaneously searches for and applies the optimum inverter switching state that can achieve certain goals, such as minimum deviation between reference and actual power; so that both power components (P and Q) are well controlled to their reference values. In addition, an effective method to attenuate undesired cross coupling between the P and Q control loops, which occurs only during transient operation, is investigated. The proposed method is based on the variation of the weight factors of the terms of the FCS-MPC cost function, so a higher weight factor is assigned to the cost function term that is exposed to greater disturbance. Empirical formulae of optimum weight factors as functions of the reference active and reactive power signals are proposed and mathematically derived. The investigated FCS-MPC control scheme is incorporated with the LVRT function to support the grid voltage in fulfilling and accomplishing the up-to-date grid codes. The LVRT algorithm is based on a modification of the references of active and reactive powers as functions of the instantaneous grid voltage such that suitable values of P and Q are injected to the grid during voltage sag. The performance of the elaborated FCS-MPC PQ scheme is studied under various operating scenarios, including steady-state and transient conditions. Results demonstrate the validity and effectiveness of the proposed scheme with regard to the achievement of high-performance operation and quick response of grid-tied inverters during normal and fault modes.     

An efficient bifunctional Ni-Nb2O5 nanocatalysts for the hydrodeoxygenation of anisole

The Ni-Nb₂O₅ nanocatalysts have been prepared by the sol–gel method, and the catalytic hydrodeoxygenation (HDO) performance of anisole as model compound is studied. The results show that Nb exists as amorphous Nb₂O₅ species, which can promote Ni dispersion. The addition of Nb₂O₅ increases the acidity of the catalyst. However, when the content of niobium is high, there is an inactive Nb-Ni-O mixed phase. The size and morphology of Ni grains in catalysts are different due to the difference of Nb/Ni molar ratio. The Ni_0.9Nb_0.1 sample has the largest surface area of 170.8 m²·g^-1 among the catalysts prepared in different Nb/Ni molar ratios, which is mainly composed of spherical nanoparticles and crack pores. The HDO of anisole follows the reaction route of the hydrogenation HYD route. The Ni_0.9Nb_0.1 catalyst displayed a higher HDO performance for anisole than Ni catalyst. The selectivity to cyclohexane over the Ni_0.9Nb_0.1 sample is about 10 times that of Ni catalyst at 220 ℃ and 3 MPa H₂. The selectivity of cyclohexane is increased with the increase of reaction temperature. The anisole is almost completely transformed into cyclohexane at 240 ℃, 3 MPa H₂ and 4 h.