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排序方式: 共有355条查询结果,搜索用时 312 毫秒
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Sobia Noreen Sara Hasan Shazia Akram Ghumman Syed Nasir Abbas Bukhari Bushra Ijaz Huma Hameed Huma Iqbal Afeefa Aslam Mervat Abdelaziz Mohamed Elsherif Shazia Noureen Hasan Ejaz 《International journal of molecular sciences》2022,23(5)
The rapid progression in biomaterial nanotechnology apprehends the potential of non-toxic and potent polysaccharide delivery modules to overcome oral chemotherapeutic challenges. The present study is aimed to design, fabricate and characterize polysaccharide nanoparticles for methotrexate (MTX) delivery. The nanoparticles (NPs) were prepared by Abelmoschus esculentus mucilage (AEM) and chitosan (CS) by the modified coacervation method, followed by ultra-sonification. The NPs showed much better pharmaceutical properties with a spherical shape and smooth surface of 213.4–254.2 nm with PDI ranging between 0.279–0.485 size with entrapment efficiency varying from 42.08 ± 1.2 to 72.23 ± 2.0. The results revealed NPs to possess positive zeta potential and a low polydispersity index (PDI). The in-vitro drug release showed a sustained release of the drug up to 32 h with pH-dependence. Blank AEM -CS NPs showed no in-vivo toxicity for a time duration of 14 days, accompanied by high cytotoxic effects of optimized MTX loaded NPs against MCF-7 and MD-MBA231 cells by MTT assay. In conclusion, the findings advocated the therapeutic potential of AEM/CS NPs as an efficacious tool, offering a new perspective for pH-responsive routing of anticancer drugs with tumor cells as a target. 相似文献
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Waqar Ahmad Ali Al-Matar Zaheer Aslam Izhar A. Malik Hafiz M. Irshad 《Chemical Engineering Communications》2020,207(7):946-960
AbstractA series of Cu-K/Al2O3 catalysts were synthesized by wet impregnation technique. The reduced catalysts were further used for conversion of carbon dioxide to methane and carbon monoxide. Moreover, the fresh and used catalysts were characterized to investigate the changes in the surface morphology, metal dispersion, surface area, crystalline phases, and functional groups of studied catalysts. The SEM analysis of fresh and spent catalysts showed no remarkable difference in surface morphology with irregular shaped agglomerated particles. Furthermore, TEM micrographs presented the well distribution of metal catalyst over alumina support. The decrease in surface area from 115 to 77?m2/g for Cu1.62-K0.5/Al2O3 after reaction was related to sintering and oxidation of catalyst during reaction. XRD revealed the disappearance of some minor peaks which can be associated with the sintering of spent catalyst. FTIR also presented some new peak for spent catalyst which can be linked with metal oxides. Moreover, various reaction conditions of temperature (230, 400, and 600?°C), pressure (1 and 7?bar), and feed molar ratio of H2/CO2 (2:1 and 4:1) were investigated using different Cu loading (0, 1, 1.25, 1.62, and 4 weight percent). A maximum CO2 conversion of 63% with 39% CH4 selectivity was achieved by using Cu1.62-K0.5/Al2O3 at 600?°C, molar ratio of H2/CO2 4 under 7?bar. The presence of K on the surface of synthesized catalyst increased the CO2 conversion from 48% (Cu1/Al2O3) to 55% (Cu1-K0.5/Al2O3) at above mentioned reaction conditions which suggested the promoter effect of K during conversion of carbon dioxide. 相似文献
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Shahid M. Ramay Asif Mahmood Hamid M. Ghaithan Nasser S. Al-Zayed Adnan Aslam Abdullah Murtaza Nisar Ahmad Saadat A. Siddiqi Murtaza Saleem 《中国稀土学报(英文版)》2019,37(9):989-994
Dy_2O_3 is a rare earth oxide having a number of advanced applications in various fields including protective or antireflective coatings, Main objective of this novel research work is to check the effect of Cr and Cu addition on different properties of Dy_2O_3 and achievement of antireflective thin films with enhanced abso rption. Thin films of these materials we re deposited using DC magnetron with reactive cosputtering. XRD studies reveals the crystalline nature of thin films having Dy_2O_3(222) reflection in all samples with Cr_2O_3(116) and CuO(111) reflections in Cr and Cu containing compositions. Field emission scanning electron microscopy demonstrates the homogeneous deposition of thin films with uniform shape, size and distribution of grains. Refractive index, extinction coefficient and absorption coefficient significantly increase while optical reflectance decreases with Cr and Cu mediation corroborating an improved antireflective mechanism. The imaginary part of dielectric constant is found to increase slightly with low tangent loss for Cr containing composition co nsidered favorable for energy storage applications. 相似文献
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The pentacene thin film transistor was fabricated on a SiO2/Si substrate by thermal evaporated method at room temperature. Electrical characteristics of the pentacene transistor subjected to a UV light excitation at a wavelength of 365 nm were analyzed. A significant increase in the drain current of the pentacene thin film transistor under a UV excitation of 365 nm is observed with a maximum photosensitivity of 4.51 in the depletion regime. It is concluded that the pentacene thin film transistor can be used in UV photo-detecting devices. 相似文献
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A Web-based remote interactive laboratory (RIL) developed to deliver Internetworking laboratory experience to geographically remote graduate students is presented in this paper. The onsite Internetworking program employs hands-on laboratories in a group setting that correlates with the constructivist and collaborative pedagogical approach. This paper discusses the pedagogical and technical considerations that influence the design and implementation of the remote laboratory environment given the constraints of the special hardware and learning outcomes of the program. For wide-ranging usability, the remote Internetworking (INWK) laboratory uses de facto networking standards and commercial and broad-band Internet connectivity to ensure real-time secure interaction with equipment. A four-tier role architecture consisting of faculty, local facilitators, remote facilitators, and students has been determined appropriate to maintain academic integrity and ensure good quality of interaction with the remote laboratory. A survey employing a five-point scale has been devised to measure the usability of the remote access INWK laboratory. 相似文献
19.
Tariq D. Aslam 《Journal of scientific computing》2003,19(1-3):37-62
A level set algorithm for tracking discontinuities in hyperbolic conservation laws is presented. The algorithm uses a simple finite difference approach, analogous to the method of lines scheme presented in [36]. The zero of a level set function is used to specify the location of the discontinuity. Since a level set function is used to describe the front location, no extra data structures are needed to keep track of the location of the discontinuity. Also, two solution states are used at all computational nodes, one corresponding to the real state, and one corresponding to a ghost node state, analogous to the Ghost Fluid Method of [12]. High order pointwise convergence was demonstrated for scalar linear and nonlinear conservation laws, even at discontinuities and in multiple dimensions in the first paper of this series [3]. The solutions here are compared to standard high order shock capturing schemes, when appropriate. This paper focuses on the issues involved in tracking discontinuities in systems of conservation laws. Examples will be presented of tracking contacts and hydrodynamic shocks in inert and chemically reacting compressible flow. 相似文献
20.
Magnetic nanoparticles have emerged as an important class of functional nanostructures with potential applications of magnetic resonance imaging, drug targeting, and bio-conjugation. We have developed a modified sol–gel approach to synthesize stable and well-dispersed magnetic Co@SiO2 nanoparticles with improved control over shell thickness and larger core diameters. These well-defined Co@SiO2 core–shell nanoparticles exhibit useful magnetic properties, and the protective silica shell allows them to be surface modified for bioconjugation for various biomedical applications. The core–shell nanoparticles were characterized by transmission electron microscopy, energy-dispersive spectroscopy, elemental mapping, and the line compositional analyses to demonstrate that uniform individually isolated core–shell nanoparticles are obtained through the improved synthetic route. 相似文献