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排序方式: 共有133条查询结果,搜索用时 15 毫秒
51.
Hassan Hejase Saleh S. Hayek Shahnaz Qadri Yousef Haik 《Journal of magnetism and magnetic materials》2012
Manganese zinc iron magnetic nanoparticles were synthesized by a co-precipitation method for application as hyperthermia inducing agents. The structure, morphology and magnetic properties of the nanoparticles are characterized using scanning electron microscopy, X-ray diffraction, and a superconducting quantum interference device. The magnetic properties being investigated include Curie temperature, saturation magnetization, remnant magnetization, coercive field, and hysteresis. The study showed that adjusting the Mn contribution to the particles contributed to the adjustment of all magnetic properties of the complex. 相似文献
52.
Syed B. Qadri Anthony Garzarella Terrence Wieting Dong Ho Wu Nadeemullah A. Mahadik 《Applied Physics A: Materials Science & Processing》2009,94(4):1011-1013
Sr0.75Ba0.25NbO3 (SBN-75) has the tungsten-bronze structure with a tetragonal unit cell and exhibits electro-optic properties that are important
for sensors. Due to its quaternary nature, its structural uniformity, integrity, and homogeneity become important for these
applications. In this paper, we present high-resolution X-ray diffraction studies of the crystalline quality and lattice parameter
variation across the surface of single crystals of SBN-75. Using rocking curves, topographs, and point-wise measurements of
lattice parameters, we show that these crystals have a high degree of crystalline quality and microscopic homogeneity for
any electro-optic application. 相似文献
53.
Highly ordered superlattices are typically created through the sequential deposition of two different materials. Here, we report our experimental observation of spontaneous formation of superlattices in coevaporation of Au and Ni under energetic ion bombardment. The superlattice periodicities are on the order of a few nanometers and can be adjusted through the energy and flux of ion beams. Such a self-organization process is a consequence of the bombardment-induced segregation and uphill diffusion within the advancing nanoscale subsurface zone in the film growth. Our observations suggest that ion beams can be employed to make tunable natural superlattices in the deposition of phase-separated systems with strong bombardment-induced segregation. 相似文献
54.
Muhammad Ali Khalid Mohammed Khan Uzma Salar Mohammed Ashraf Muhammad Taha Abdul Wadood Sujhla Hamid Muhammad Riaz Basharat Ali Shahbaz Shamim Farman Ali Shahnaz Perveen 《Molecular diversity》2018,22(4):841-861
This study is focused on the identification of thiazole-based inhibitors for the \(\alpha \)-glucosidase enzyme. For that purpose, (E)-2-(2-(arylmethylene)hydrazinyl)-4-arylthiazole derivatives were synthesized in two steps and characterized by various spectroscopic techniques. All derivatives and intermediates were evaluated for their in vitro \(\alpha \)-glucosidase inhibitory activity. Thiosemicarbazones 20 and 35, and cyclized thiazole derivatives 2, 5–11, 13, 15, 21–24, 27–31, and 36–37 showed significant inhibitory potential in the range of \(\hbox {IC}_{50}=6.2\pm 0.19\)–\(43.6\pm 0.23~\upmu \hbox {M}\) as compared to standard acarbose (\(\hbox {IC}_{50}=37.7\pm 0.19~\upmu \hbox {M}\)). A molecular modeling study was carried out to understand the binding interactions of compounds with the active site of enzyme. 相似文献
55.
Silica supported ammonium dihydrogen phosphate (NH(4)H(2)PO(4)/SiO(2)) is found to be a recyclable heterogeneous catalyst for a rapid and efficient synthesis of various aryl-14-H-dibenzo[a,j]xanthenes with excellent yields using ultrasonic irradiation. The present methodology offers several advantages such as excellent yields, simple procedure, short reaction times and milder conditions. 相似文献
56.
Thamer A. Bouback Sushil Pokhrel Abdulaziz Albeshri Amal Mohammed Aljohani Abdus Samad Rahat Alam Md Saddam Hossen Khalid Al-Ghamdi Md. Enamul Kabir Talukder Foysal Ahammad Ishtiaq Qadri Jesus Simal-Gandara 《Molecules (Basel, Switzerland)》2021,26(16)
Middle East respiratory syndrome coronavirus (MERS-CoV) is a highly infectious zoonotic virus first reported into the human population in September 2012 on the Arabian Peninsula. The virus causes severe and often lethal respiratory illness in humans with an unusually high fatality rate. The N-terminal domain (NTD) of receptor-binding S1 subunit of coronavirus spike (S) proteins can recognize a variety of host protein and mediates entry into human host cells. Blocking the entry by targeting the S1-NTD of the virus can facilitate the development of effective antiviral drug candidates against the pathogen. Therefore, the study has been designed to identify effective antiviral drug candidates against the MERS-CoV by targeting S1-NTD. Initially, a structure-based pharmacophore model (SBPM) to the active site (AS) cavity of the S1-NTD has been generated, followed by pharmacophore-based virtual screening of 11,295 natural compounds. Hits generated through the pharmacophore-based virtual screening have re-ranked by molecular docking and further evaluated through the ADMET properties. The compounds with the best ADME and toxicity properties have been retrieved, and a quantum mechanical (QM) based density-functional theory (DFT) has been performed to optimize the geometry of the selected compounds. Three optimized natural compounds, namely Taiwanhomoflavone B (Amb23604132), 2,3-Dihydrohinokiflavone (Amb23604659), and Sophoricoside (Amb1153724), have exhibited substantial docking energy >−9.00 kcal/mol, where analysis of frontier molecular orbital (FMO) theory found the low chemical reactivity correspondence to the bioactivity of the compounds. Molecular dynamics (MD) simulation confirmed the stability of the selected natural compound to the binding site of the protein. Additionally, molecular mechanics generalized born surface area (MM/GBSA) predicted the good value of binding free energies (ΔG bind) of the compounds to the desired protein. Convincingly, all the results support the potentiality of the selected compounds as natural antiviral candidates against the MERS-CoV S1-NTD. 相似文献
57.
58.
CuBr has been pressurized to 8.3 GPa in four separate runs. Prima facie evidence of pressure-induced disproportionation of cuprous bromide into cupric bromide has been observed on release of pressure from 7 GPa. Evidence is also seen of a phase change in CuBr2 above 5.5 GPa. 相似文献
59.
Khan KM Saify ZS Begum S Noor F Khan MZ Hayat S Choudhary MI Perveen S Atta-Ur-Rahman Zia-Ullah 《Natural product research》2003,17(2):115-125
7-Hydroxy-4-methyl-2H-chromen-2-one (2), 7-hydroxy-4,5-dimethyl-2H-chromen-2-one (15) and their some derivatives were synthesized for exploring selected biological screening. The compounds 9 and 13 had shown high degree of cytotoxic activity. Three compound 9, 10 and 13 showed high degree of bactericidal activity amongst the present series. 相似文献
60.
In situ generation of hydrogen iodide from cesium iodide/methanesulfonic acid was found to be an attractive reagent combination for the conversion of alkyl, allyl, and benzyl alcohols to their corresponding iodides under mild conditions. The method is compared with that using cesium iodide/p-toluenesulfonic acid or cesium iodide/aluminium chloride. 相似文献