排序方式: 共有65条查询结果,搜索用时 12 毫秒
1.
Jing Qin Guohai Liang Bingxi Feng Gen Wang Na Wu Yonghui Deng Ahmed A. Elzatahry Abdulaziz Alghamdi Yongxi Zhao Jing Wei 《中国化学快报》2021,32(2):842-848
Plant polyphenol-based coordination polymers(CPs) with ultra-small particle size and tailorable compositions are highly desired in biomedical applicatio ns,but their synthesis is still challenging due to the sophisticated coordination assembly process and unavoidable self-oxidation polymerization of polyphenol. He rein,a general ligand covalent-modification mediated coordination assembly strategy is proposed for the synthesis of water-dispersible CPs with tunable metal species(e.g., Gd,Cu,Ni,Zn,Fe)and ultra-small diameter(8.6-37.8 nm) using nontoxic plant polyphenol(e.g..tannic acid,gallic acid) as a polymerizable ligand.Polyphenol molecules react with formaldehyde firstly,which can effectively retard the oxidation induced self-polymerization of polyphenol and lead to the formation of metal ions containing CPs colloidal nanoparticles.These ultrafine nanoparticles with stably chelated metal io ns are highly water dispersible and thus advantageous for bioimaging.As an example,ultra-small Gd contained CPs exhibit higher longitudinal relaxivity(r_1=25.5 L mmol ~1 s ~1) value with low r_2/r_1(1.19) than clinically used Magnevist(Gd-DTPA,r_1=3.7 L mmol ~1 s ~1).Due to the enhanced permeability and retention effect,they can be further used as a positive contrast agent for T_1-weighted MR imaging of tumour. 相似文献
2.
Ashraf M. Muhammad Ali Zari Nouf H. Alsubhi Maryam H. Al-Zahrani Rana Abdullah Alghamdi Mai M. Labib 《Molecules (Basel, Switzerland)》2022,27(14)
Aptamers, the nucleic acid analogs of antibodies, bind to their target molecules with remarkable specificity and sensitivity, making them promising diagnostic and therapeutic tools. The systematic evolution of ligands by exponential enrichment (SELEX) is time-consuming and expensive. However, regardless of those issues, it is the most used in vitro method for selecting aptamers. Therefore, recent studies have used computational approaches to reduce the time and cost associated with the synthesis and selection of aptamers. In an effort to present the potential of computational techniques in aptamer selection, a simple sequence-based method was used to design a 69-nucleotide long aptamer (mod_09) with a relatively stable structure (with a minimum free energy of −32.2 kcal/mol) and investigate its binding properties to the tyrosine kinase domain of the NT-3 growth factor receptor, for the first time, by employing computational modeling and docking tools. 相似文献
3.
4.
Hassan A. Zedan M. Alghamdi Seham Sh. Tantawy 《Mathematical Methods in the Applied Sciences》2015,38(17):4357-4364
We study in this paper the Q‐symmetry and conditional Q‐symmetries of Drinfel'd–Sokolov–Wilson equations. The solutions which we obtain in this paper take the form of convergent power series with easily computable components. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
5.
Andy K. W. Ma Ali A. Alghamdi Kassem Tofailli Nicholas M. Spyrou 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(2):353-357
Early detection of the red palm weevils (RPW) is a major challenge in agriculture among all kinds of palm trees due to the
nature of the insect and the difficulty to trace them through their life stages associated with the tree life. Many methods
have been applied for the weevil detection such as X-ray diffraction techniques, fluoroscopy and ultrasound. On the other
hand, the idea of tomography has been used for other purposes such as the determination of the age of the tree and for applied
environmental studies. Such technology can also reveal the weevil in principle. In this study, we explore the use of X-ray
CT for weevil detection with the Monte Carlo method. A model of the stem of a palm tree is developed for simulations. MCNPX
is chosen to carry out the simulations for the radiography tally in the code. The tally records the 2D data of the X-ray beams
irradiating the tree model. An iterative reconstruction method for cone beam CT is applied to obtain the 3D slices of the
tree model. We are exploring the minimum number of projection angles and the detectability of the weevil. We shall also report
the sensitivity of weevil detection using X-ray CT with a large set of simulations with different weevil sizes and tree diameters. 相似文献
6.
D. G. Beasley A. Alghamdi M. C. Freitas A. Fernandes Z. Révay 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(2):307-311
The epithermal beamline at the Portuguese Research Reactor is being optimized for Prompt Gamma Neutron Activation Analysis
(PGNAA). One of the major changes is to thermalise the beam by the introduction of a sapphire crystal into the beamline. Placing
the sapphire at the exit of the beamline would greatly reduce the alterations and work necessary to the port and make the
crystal easily removable. However, the scattered neutrons from the sapphire would increase both the neutron-induced detector
damage and the background radiation. MCNPX was used to simulate the crystal in the beam port and at the exit of the port. 相似文献
7.
Ahmad H. Alghamdi 《Arabian Journal of Chemistry》2010,3(1):1-7
Stripping voltammetric techniques are powerful analytical tools that are becoming widely used in various chemical analysis fields. Hence, the objective of this survey is to give a general overview on the scope of the applicability of stripping voltammetric methods in food industries. The applications discussed include recent studies on the utilization of these electroanalytical methods in determination of food contaminants (toxic metals, pesticide, fertilizers and veterinary drugs residuals), trace essential elements, food additive dyes and other organic compounds of biological significance. Tables that give method summaries referenced to the original work are provided. 相似文献
8.
A. A. Alghamdi J. Al-Mokhlef A. Alhaj N. M. Spyrou 《Journal of Radioanalytical and Nuclear Chemistry》2007,271(3):783-787
The technique of photon activation analysis (PAA) is widely employed in many fields as an effective non-invasive tool for
measuring elemental compositions and concentrations. In recent years there has been a revival and growing interest of PAA
in general and for medical applications in particular. The feasibility of using a PET scanner (Ecat Exact 931) to determine
nitrogen concentration in a dead rabbit is described. This method is based on the photon activation of 14N(γ,n)13N (T
1/2 = 9.9 min) using an 18 MV photon beam Medical Linear Accelerator (Varian 2300EX). 相似文献
9.
Afrah E. Mohammed Sahar S. Alghamdi Nada K. Alharbi Fatma Alshehri Rasha Saad Suliman Fahad Al-Dhabaan Maha Alharbi 《Molecules (Basel, Switzerland)》2022,27(22)
An in silico approach applying computer-simulated models helps enhance biomedicines by sightseeing the pharmacology of potential therapeutics. Currently, an in silico study combined with in vitro assays investigated the antimicrobial ability of Limoniastrum monopetalum and silver nanoparticles (AgNPs) fabricated by its aid. AgNPs mediated by L. monopetalum were characterized using FTIR, TEM, SEM, and DLS. L. monopetalum metabolites were detected by QTOF–LCMS and assessed using an in silico study for pharmacological properties. The antibacterial ability of an L. monopetalum extract and AgNPs was investigated. PASS Online predictions and the swissADME web server were used for antibacterial activity and potential molecular target metabolites, respectively. Spherical AgNPs with a 68.79 nm average size diameter were obtained. Twelve biomolecules (ferulic acid, trihydroxy-octadecenoic acid, catechin, pinoresinol, gallic acid, myricetin, 6-hydroxyluteolin, 6,7-dihydroxy-5-methoxy 7-O-β-d-glucopyranoside, methyl gallate, isorhamnetin, chlorogenic acid, 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-oxo-4H-chromen-3-yl 6-O-(6-deoxy-β-l-mannopyranosyl)-β-d-glucopyranoside) were identified. The L. monopetalum extract and AgNPs displayed antibacterial effects. The computational study suggested that L. Monopetalum metabolites could hold promising antibacterial activity with minimal toxicity and an acceptable pharmaceutical profile. The in silico approach indicated that metabolites 8 and 12 have the highest antibacterial activity, and swissADME web server results suggested the CA II enzyme as a potential molecular target for both metabolites. Novel therapeutic agents could be discovered using in silico molecular target prediction combined with in vitro studies. Among L. Monopetalum metabolites, metabolite 12 could serve as a starting point for potential antibacterial treatment for several human bacterial infections. 相似文献
10.
Uzma Yasmeen Fazal Haq Mehwish Kiran Arshad Farid Naveed Ullah Tariq Aziz Muhammad Haroon Sahid Mehmood Muhammad Muzammal Shakira Ghazanfar Majid Alhomrani Abdulhakeem S. Alamri Syed Mohammed Basheeruddin Asdaq Saleh A. Alghamdi Irfan Ullah 《Molecules (Basel, Switzerland)》2022,27(18)
In this research, a new biodegradable and eco-friendly adsorbent, starch-grafted polymethyl methacrylate (St-g-PMMA) was synthesized. The St-g-PMMA was synthesized by a free radical polymerization reaction in which methyl methacrylate (MMA) was grafted onto a starch polymer chain. The reaction was performed in water in the presence of a potassium persulfate (KPS) initiator. The structure and different properties of the St-g-PMMA was explored by FT-IR, 1H NMR, TGA, SEM and XRD. After characterization, the St-g-PMMA was used for the removal of MB dye. Different adsorption parameters, such as effect of adsorbent dose, effect of pH, effect of initial concentration of dye solution, effect of contact time and comparative adsorption study were investigated. The St-g-PMMA showed a maximum removal percentage (R%) of 97% towards MB. The other parameters, such as the isothermal and kinetic models, were fitted to the experimental data. The results showed that the Langmuir adsorption and pseudo second order kinetic models were best fitted to experimental data with a regression coefficient of R2 = 0.93 and 0.99, respectively. 相似文献