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101.
Glasses in the system TeO2/Nb2O5/ZnO/CdS were studied with respect to the density, molar volume, refractive index, polarizability, molar refraction, metallization and third order non-linear optical susceptibility. The third order non-linear optical susceptibilities, χ(3), were measured using degenerate four-wave mixing (DFWM). The addition of CdS to TeO2-based glasses leads to increasing refractive as well as the non-linear refractive indices. The largest measured value of the third order non-linear optical susceptibility was 7.8 × 10?13 esu and has been found in the 90TeO2 · 5Nb2O5 · 5ZnO · 0.4 CdS glass. The non-linear optical susceptibility increased with increasing CdS-concentration. In order to estimate the third order non-linear optical susceptibility, the theoretical model of Lines and the empirical equation of Miller were used. 相似文献
102.
Hussein Bassal Akram Hijazi Hussein Farhan Christine Trabolsi Bouchra Sayed Ahmad Alia Khalil Marc Maresca Fawaz El Omar 《Molecules (Basel, Switzerland)》2021,26(15)
Psophocarpus tetragonolobus has long been used in traditional medicine and cuisine. In this study, Psophocarpus tetragonolobus extracts were isolated by maceration and ultrasound-assisted extraction and were evaluated for their antioxidant and anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The obtained results show that both extracts (maceration and ultrasound) were rich in bioactive molecules and exerted substantial antioxidant and anti-inflammatory effects. The P. tetragonolobus extracts’ treatment in LPS-stimulated RAW264.7 macrophages resulted in a significant downregulation of the expressions of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β mRNA. In addition, the P. tetragonolobus extracts’ treatment attenuated inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. Our observations indicate that there is no significant difference between the two studied extracts of P. tetragonolobus in terms of biological properties (specifically, antioxidant and anti-inflammatory effects. Regardless of the extraction method, P. tetragonolobus could be used for treating diseases related to oxidative stress and inflammatory reactions. 相似文献
103.
Nagwa Abo El-Maali Asmaa Y. Wahman Aref A.M. Aly Ahmed Y. Nassar Douaa M. Sayed 《应用有机金属化学》2020,34(6):e5594
Lanthanide complexes are of increasing importance in cancer diagnosis and therapy. In the present study 1:1 and 1:3 solid complexes of La (III)–5-FU (5-fluorouracil) were prepared and characterized. In solution, the formation of 1:1 La (III) and Eu (III) complexes enabled the enhancement of 5-FU's effectiveness. Binding constants of the 1:1 complexes of both metals were estimated using spectrophotometry and HPLC with fluorescence detection methods. The thermodynamic parameters ΔG ° , ΔH ° and ΔS ° were calculated using differential scanning calorimetry. Evaluation of the cytotoxic activity of the 1:1 La (III)- and Eu (III)–5-FU complexes was performed through two methodologies, trypan blue for cell viability where La (III)- and Eu (III)–5-FU complexes were found to have 52,000 and 80,000 dead cells, respectively, and via flow cytometric analysis to measure the apoptotic values, which were found to be 59.87 and 86.86% respectively. 相似文献
104.
Omar Abo-Bakr Omar Abdel-Rahman Mohamed A. E. El-Mongy Sayed A. 《Physics of Particles and Nuclei Letters》2019,16(6):835-841
Physics of Particles and Nuclei Letters - The natural radioactivity measurements and analysis of 232Th have been studied using γ-ray spectroscopy depending on its decay daughters in... 相似文献
105.
The electrochemical behavior of Zn in 0.5 M NaOH solutions containing various concentrations (0.01–0.1 M) of ClO3 ? or ClO4 ? anions was studied with potentiodynamic anodic polarization and chronoamperometry techniques. Microstructural and topographical characterization of the pitted surfaces was carried out by ex situ scanning electron microscopy and atomic force microscopy examinations. Addition of either ClO3 ? or ClO4 ? stimulated general corrosion and ruptured the passive layer (stable pitting), with ClO3 ? being more aggressive than ClO4 ?. Metastable pitting events appear as current oscillations (spikes) at potentials close to the pitting potential when Cl? ions are produced by cathodic reduction of ClO3 ? and ClO4 ? before passive layer growth. Current–time measurements are performed at fixed potential after production of Cl? ions and show that the rate of metastable pitting and the intensity of current spikes increase with the potential and the concentration of aggressive anions. Concepts of thin film growth are applied to the passive layer formation in order to explain those results. Metastable events are related to the presence of defects in the passive layer because their frequency and intensity are enhanced in conditions that favor defect formation and roughening in growing films, while stable pitting typically occurs at regions of high metal disorder. 相似文献
106.
Hexametaphosphate‐Capped Silica Mesoporous Nanoparticles Containing CuII Complexes for the Selective and Sensitive Optical Detection of Hydrogen Sulfide in Water 下载免费PDF全文
Sameh El Sayed Dr. Michele Milani Prof. Maurizio Licchelli Prof. Ramón Martínez‐Máñez Dr. Félix Sancenón 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7002-7006
CuII‐macrocycle functionalized hexametaphosphate‐capped silica mesoporous nanoparticles have been prepared and used for the selective and sensitive detection of hydrogen sulfide in aqueous environments. The possibility of using different metal complexes combined with different capping anions and choice of different dyes or other sensing molecules as indicators makes this new protocol highly appealing for the preparation of new sensing systems for sulfide detection in different environments. 相似文献
107.
The present study illustrates conventional and microwave reactions of 5-amino-1,3-diaryl-pyrazole-4-carbonitrile derivative with phenacyl bromide under different conditions, hydrazine hydrate, hydroxylamine hydrochloride, tetrahydrofuran, phthalic anhydride, and cyanoacetic acid. The product of the latter reaction condensed with hydrazine and cyclohexanone to give the pyrazolotriazepine acetonitrile and cyclohexylidene derivatives. The new cyclohexylidene is used as key intermediate to synthesize some new spiro compounds. The behavior of the starting compound with benzaldehyde, ethylenediamine, phenylenediamine, sodium azide, 1-amino-2-hydroxynaphthalene-7-sulphonic acid, diethylmalonate, terephthalaldehyde, acetyl chloride, and acetic anhydride were also investigated. The new compounds structures were established from spectroscopic data. Some of the new pyrazole derivatives showed antibacterial and anticancer activities. 相似文献
108.
109.
Sayed Ali Akbar Ghorashi 《Annalen der Physik》2020,532(2):1900336
It is shown that hybrid Dirac and Weyl semimetals can be realized in a 3D Luttinger semimetal with quadratic band touching (QBT). This is illustrated using a periodic kicking scheme. In particular, the focus is on a momentum-dependent driving (nonuniform driving) and the realization of various hybrid Dirac and Weyl semimetals is demonstrated. A unique hybrid dispersion Dirac semimetal with two nodes is identified, where one of the nodes is linear while the other is dispersed quadratically. Next, it is shown that by tilting QBT via periodic driving and in the presence of an external magnetic field, one can realize various single/double hybrid Weyl semimetals depending on the strength of external field. Finally, it is noted that in principle, phases that are found in this work can also be realized by employing the appropriate electronic interactions. 相似文献
110.
Hani A. Alhadrami Ahmed M. Sayed Ahmed M. Sharif Esam I. Azhar Mostafa E. Rateb 《Molecules (Basel, Switzerland)》2021,26(9)
SARS CoV-2 pandemic is still considered a global health disaster, and newly emerged variants keep growing. A number of promising vaccines have been recently developed as a protective measure; however, cost-effective treatments are also of great importance to support this critical situation. Previously, betulinic acid has shown promising antiviral activity against SARS CoV via targeting its main protease. Herein, we investigated the inhibitory potential of this compound together with three other triterpene congeners (i.e., ursolic acid, maslinic acid, and betulin) derived from olive leaves against the viral main protease (Mpro) of the currently widespread SARS CoV-2. Interestingly, betulinic, ursolic, and maslinic acids showed significant inhibitory activity (IC50 = 3.22–14.55 µM), while betulin was far less active (IC50 = 89.67 µM). A comprehensive in-silico analysis (i.e., ensemble docking, molecular dynamic simulation, and binding-free energy calculation) was then performed to describe the binding mode of these compounds with the enzyme catalytic active site and determine the main essential structural features required for their inhibitory activity. Results presented in this communication indicated that this class of compounds could be considered as a promising lead scaffold for developing cost-effective anti-SARS CoV-2 therapeutics. 相似文献