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21.
New complex Co(III) with ligand Pyridoxal-S-methyl-isothiosemicarbazone, (PLITSC) was synthesized. X-ray analysis showed the bis-ligand octahedral structure of the cobalt complex [Co(PLITSC-H)2]BrNO3·CH3OH (compound 1). The intermolecular interactions governing the crystal structure were described by the Hirsfeld surface analysis. The structure of compound 1 and the corresponding Zn complex (([Zn(PLTSC)(H2O)2]SO4·H2O)) were optimized at the B3LYP/6–31 + G (d,p)/LanL2DZ level of theory, and the applicability was assessed by comparison with the crystallographic structure. The natural bond orbital analysis was used for the discussion on the stability of formed compounds. The antibacterial activity of obtained complexes towards S. aureus and E. coli was determined, along with the effect of compound 1 on the formation of free radical species. Activity of compound 1 towards the removal of methylene blue was also investigated. The voltammograms of these compounds showed the reduction of metal ions, as well as the catalyzed reduction of CO2 in acidic media.  相似文献   
22.
Structural Chemistry - Friedel–Crafts acyl rearrangements in PPA (at 80–240 °C) and Scholl reactions in AlCl3/NaCl (at 140–220 °C) of...  相似文献   
23.
1,5-, 1,8- and 9,10-diacetylanthracenes undergo Friedel-Crafts acyl rearrangements in polyphosphoric acid at 130-150 °C to give 3-methylbenz[de]anthracen-1-one via the kinetically-controlled 1,9-diacetylanthracene. The rearrangement mechanism is supported by DFT calculations of diacetylanthracenes, their σ-complexes, O-protonates, and O,O-diprotonates. The importance of kinetic control versus thermodynamic control in Friedel-Crafts acyl rearrangements is highlighted. Certain features of reversibility are also suggested.  相似文献   
24.
Thermomechanical loading, in the same way that mechanical loading can cause significant stress violations, may give rise to significant stress variations and concentrations and in some circumstances can result in structural destruction or even failure. This clearly shows the importance of accurate stress analysis of thermal-loaded structures. This paper presents three-dimensional thermomechanical stress analysis of heterogeneous adhesively bonded joints undergoing steady-state one-dimensional heat conduction using the full layerwise theory. In this approach, the fully coupled three-dimensional governing equilibrium equations are derived generally for an orthotropic joint based on the use of variational calculus and the principle of minimum total potential energy. The through-thickness temperature distribution is determined using the equivalent thermal-resistant model and is rewritten in the layerwise form. The governing equations of equilibrium then are analytically solved using the state space approach. The accurate results presented in this study are compared and verified via analytical as well as numerical investigations, and the study shows rapid converging solutions.  相似文献   
25.
This work investigated the effect of Potassium Permanganate (KMnO4) on graphene oxide (GO) properties, especially on electrical properties. The GO thin films were deposited on a glass substrate using drop casting technique and were analysed by using various type of spectroscopy (e.g. Scanning Electron Microscopy (SEM), Ultra- Violet Visible (UV–VIS), Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), optical band gap, Raman Spectroscopy). Furthermore, the electrical experiments were carried out by using current–voltage (I-V) characteristic. The GO thin film with 4.5 g of KMnO4 resulted in higher conductivity which is 3.11 × 10?4 S/cm while GO with 2.5 g and 3.5 g of KMnO4 achieve 2.47 × 10?9 S/cm and 1.07 × 10?7 S/cm, respectively. This further affects the morphological (SEM), optical (band gap, UV–Vis, FTIR, and Raman), and crystalline structural (XRD) properties of the GO thin films. The morphological, elemental, optical, and structural data confirmed that the properties of GO is affected by different amount of KMnO4 oxidizing agent, which revealed that GO can potentially be implemented for electrical and electronic devices.  相似文献   
26.
This paper describes the synthesis and characterization of heteropolynuclear redox active materials [FerCuCl]4YY′, Y = Y′ = O, Y = Y′ = Cat and Y = O, Y′ = Cat, Fer = N,N-dimethylaminomethylferrocene and Cat = 3,4, 5,6-tetrachlorocatecholato ligand. Manometric O2 uptake measurements in PhNO2 show that tetranuclear [FerCuCl]4 and [FerCuCl]4Cat give the tetranuclear oxocopper(II) products [FerCuCl]4O2 and [FerCuCl]4CatO, respectively. The absence of carbonyl stretching vibrational bands in [FerCuCl]4Cat2 and [FerCuCl]4CatO suggest that tetrachloro-1,2-benzoquinone (TClBQ) is reduced to the corresponding catecholete during the oxidation of copper(I) centers in [FerCuCl]4. The near i.r. electronic spectra for [FerCuCl]4O2, [FerCuCl]4CatO and [FerCuCl]4Cat2 exhibit broad intense split maxima in the 750–875 nm range, attributed to a minimum of three halide ligands per Cu. Room temperature solid state e.p.r. spectra for [FerCuCl]4CatO and [FerCuCl]4Cat2 are of the axial type, suggesting a square pyramidal geometry around CuII.  相似文献   
27.
A layerwise theory is used to analyze analytically displacements and stresses in functionally graded composite plates in cylindrical bending subjected to thermomechanical loadings. The plates are assumed to have isotropic, two-constituent material distribution through the thickness, and the modulus of elasticity of the plate is assumed to vary according to a power-law distribution in terms of the volume fractions of the constituents. The non-linear strain–displacement relations in the von Kármán sense are used to study the effect of geometric non-linearity. The equilibrium equations are solved exactly and also by using a perturbation technique. Numerical results are presented to show the effect of the material distribution on the deflections and stresses.  相似文献   
28.
An analytical solution for bending of composite sector plates is presented using multi-term extended Kantorovich method (MTEKM). The governing equations are derived using the displacement field of the first-order shear deformation theory and converted into two sets of coupled ordinary differential equations (ODEs) utilizing MTEKM. Next, an analytical iterative procedure is presented for solving the derived sets of ODEs based on state-space method. Numerous examples are studied by the present method, and as special cases, solid sector and rectangular plates are also investigated. Next, the results obtained by the present method are compared to those of finite element method and other results available in the literature. It is found that the present method has a high convergence rate as well as good accuracy in all cases.  相似文献   
29.
Cancer is a major disease with a high mortality rate worldwide. In many countries, cancer is considered to be the second most common cause of death after cardiovascular disease. The clinical management of cancer continues to be a challenge as conventional treatments, such as chemotherapy and radiation therapy, have limitations due to their toxicity profiles. Unhealthy lifestyle and poor dietary habits are the key risk factors for cancer; having a healthy diet and lifestyle may minimize the risk. Epidemiological studies have shown that a high fruit and vegetable intake in our regular diet can effectively reduce the risk of developing certain types of cancers due to the high contents of antioxidants and phytochemicals. In vitro and in vivo studies have shown that phytochemicals exert significant anticancer effects due to their free radical scavenging capacity potential. There has been extensive research on the protective effects of phytochemicals in different types of cancers. This review attempts to give an overview of the etiology of different types of cancers and assesses the role of phytonutrients in the prevention of cancers, which makes the present review distinct from the others available.  相似文献   
30.
Nitrogen-containing atoms in their core structures have been exclusive building blocks in drug discovery and development. One of the most significant and well-known heterocycles is the 1,3,4-thidiazole nucleus, which is found in a wide range of natural products and therapeutic agents. In the present work, certain tris-1,3,4-thiadiazole derivatives (6, 7) were synthesized through a multi-step synthesis approach. All synthesized compounds were characterized using different spectroscopic tools. Previously, thiadiazole compounds as anti-Toxoplasma gondii agents have been conducted and reported in vitro. However, this is the first study to test the anti-Toxoplasma gondii activity of manufactured molecular hybrids thiadiazole in an infected mouse model with the acute RH strain of T. gondii. All the observed results demonstrated compound (7)’s powerful activity, with a considerable reduction in the parasite count reaching 82.6% in brain tissues, followed by liver and spleen tissues (65.35 and 64.81%, respectively). Inflammatory and anti-inflammatory cytokines assessments proved that Compound 7 possesses potent antiparasitic effect. Furthermore, docking tests against TgCDPK1 and ROP18 kinase (two major enzymes involved in parasite invasion and egression) demonstrated compound 7’s higher potency compared to compound 6 and megazol. According to the mentioned results, tris-1,3,4-thiadiazole derivatives under test can be employed as potent antiparasitic agents against the acute RH strain of T. gondii.  相似文献   
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