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排序方式: 共有306条查询结果,搜索用时 156 毫秒
301.
Watkins NN Sridhar S Cheng X Chen GD Toner M Rodriguez W Bashir R 《Lab on a chip》2011,11(8):1437-1447
We have developed a microfabricated biochip that enumerates CD4+ T lymphocytes from leukocyte populations obtained from human blood samples using electrical impedance sensing and immunoaffinity chromatography. T cell counts are found by obtaining the difference between the number of leukocytes before and after depleting CD4+ T cells with immobilized antibodies in a capture chamber. This differential counting technique has been validated to analyze physiological concentrations of leukocytes with an accuracy of ~9 cells per μL by passivating the capture chamber with bovine serum albumin. In addition, the counter provided T cell counts which correlated closely with an optical control (R(2) = 0.997) for CD4 cell concentrations ranging from approximately 100 to 700 cells per μL. We believe that this approach can be a promising method for bringing quantitative HIV/AIDS diagnostics to resource-poor regions in the world. 相似文献
302.
Chamakura K Perez-Ballestero R Luo Z Bashir S Liu J 《Colloids and surfaces. B, Biointerfaces》2011,84(1):88-96
Engineered nanomaterials display significant advantages due to their unique nanostructure, along with their tuneable properties for the designed application. Silver nanoparticles (Ag-NPs) have drawn attention due to their use as potent bactericidal agents and were characterized in this research to provide an understanding of the interaction between nanomaterials and bacteria. This work presents the bactericidal performance of Ag-NPs using Escherichia coli (E. coli) as a model microorganism. Several state-of-the-art techniques, such as high-angle annular dark-field detector in scanning transmission electron microscopy, and energy filtered imaging in electron energy loss spectroscopy, were employed to obtain nanostructural and elemental information. The bactericidal activities of Ag-NPs were then compared with two commonly used disinfectants, sodium hypochlorite (NaClO) and phenol (C(6)H(5)OH). These two chemical disinfectants exhibited rapid bactericidal activity, showing a minimal bactericidal concentration (MBC) of 16 parts-per-million (ppm) and 16 part-per-thousand (ppth), respectively for NaClO and C(6)H(5)OH within about 10 min. In contrast, Ag-NPs exhibit slow but long-term bactericidal effect demonstrating MBCs of 0.6 parts-per-million (ppm) within 6h when used as disinfectant. An advantage using Ag-NPs to inactivate E coli at low dosages is negligible environmental waste or hazardous by-products. The results showed that Ag-NPs caused bacterial inactivation by a mechanism involving several steps, including cell wall and cytoplasmic membrane damage. 相似文献
303.
Ashraf Ali Sarah Alharthi Bashir Ahmad Alia Naz Idrees Khan Fazal Mabood 《Molecules (Basel, Switzerland)》2021,26(22)
The adsorptive removal of lead (II) from aqueous medium was carried out by chemically modified silica monolith particles. Porous silica monolith particles were prepared by the sol-gel method and their surface modification was carried out using trimethoxy silyl propyl urea (TSPU) to prepare inorganic–organic hybrid adsorbent. The resultant adsorbent was evaluated for the removal of lead (Pb) from aqueous medium. The effect of pH, adsorbent dose, metal ion concentration and adsorption time was determined. It was found that the optimum conditions for adsorption of lead (Pb) were pH 5, adsorbent dose of 0.4 g/L, Pb(II) ions concentration of 500 mg/L and adsorption time of 1 h. The adsorbent chemically modified SM was characterized by scanning electron microscopy (SEM), BET/BJH and thermo gravimetric analysis (TGA). The percent adsorption of Pb(II) onto chemically modified silica monolith particles was 98%. An isotherm study showed that the adsorption data of Pb(II) onto chemically modified SM was fully fitted with the Freundlich and Langmuir isotherm models. It was found from kinetic study that the adsorption of Pb(II) followed a pseudo second-order model. Moreover, thermodynamic study suggests that the adsorption of Pb(II) is spontaneous and exothermic. The adsorption capacity of chemically modified SM for Pb(II) ions was 792 mg/g which is quite high as compared to the traditional adsorbents. The adsorbent chemically modified SM was regenerated, used again three times for the adsorption of Pb(II) ions and it was found that the adsorption capacity of the regenerated adsorbent was only dropped by 7%. Due to high adsorption capacity chemically modified silica monolith particles could be used as an effective adsorbent for the removal of heavy metals from wastewater. 相似文献
304.
Xingming Zeng Yi Hu Rongbin Xie Sadaf Bashir Khan Shern-Long Lee 《Molecules (Basel, Switzerland)》2021,26(24)
In recent years, extending self-assembled structures from two-dimensions (2D) to three-dimensions (3D) has been a paradigm in surface supramolecular chemistry and contemporary nanotechnology. Using organic molecules of p-terphenyl-3,5,3′,5′-tetracarboxylic acid (TPTC), and scanning tunneling microscopy (STM), we present a simple route, that is the control of the solute solubility in a sample solution, to achieve the vertical growth of supramolecular self-assemblies, which would otherwise form monolayers at the organic solvent/graphite interface. Presumably, the bilayer formations were based on π-conjugated overlapped molecular dimers that worked as nuclei to induce the yielding of the second layer. We also tested other molecules, including trimesic acid (TMA) and 1,3,5-tris(4-carboxyphenyl)-benzene (BTB), as well as the further application of our methodology, demonstrating the facile preparation of layered assemblies. 相似文献
305.
An Accelerated Algorithm Involving Quasi-$\phi$-Nonexpansive Operators for Solving Split Problems 下载免费PDF全文
Bashir Ali Aisha Aminu Adam Abubakar Adamu 《Journal of Nonlinear Modeling and Analysis》2023,5(1):54-72
In this paper, an algorithm of inertial type for approximating solutions of split equality fixed point problems involving quasi-$\phi$-nonexpansive maps is proposed and studied in the setting of certain real Banach spaces. Weak and strong convergence theorems are proved under some conditions. Some applications of the theorems are presented. The results presented extend and improve some existing results. Finally, some numerical illustrations are presented to support our theorems and their applications. 相似文献
306.
Natasha Bokhari Abida Yasmeen Asif Ali Hamad Khalid Rong Wang Mustehsan Bashir Faiza Sharif 《Macromolecular bioscience》2023,23(9):2300039
Meshes from natural silk are hand knitted and surface functionalized to facilitate hernia repair and other load bearing, tissue applications. Purified organic silk is - hand knitted and then coated with chitosan (CH)/bacterial cellulose (BC) blend polymer using four phytochemicals such as pomegranate (PG) peel, Nigella sativa (NS) seed, Licorice root (LE), and Bearberry leaf extracts (BE) separately. Characterizations using GCMS analysis shows the presence of bioactive chemicals in the extracts. Scanning electron microcopy (SEM) shows that the surface is coated with the composite polymer t. Fourier transform infrared spectroscopy (FTIR) shows significant elements found in CH, BC, and phytochemicals in plant extracts with no chemical changes. Tensile strength of the coated meshes is higher to support tissue as implants. The release kinetics suggest sustained release of phytochemical extracts. In vitro studies confirmed the noncytotoxic, biocompatible, wound healing potential of the meshes. Furthermore, gene expression analysis of 3-wound healing genes shows marked increase in the in vitro cell cultures due to the presence of extracts. These results suggest that the composite meshes can efficiently support hernia closure while facilitating wound/tissue healing and combating bacterial infections. Therefore, these meshes can be good candidates for fistula and cleft palate repair. 相似文献