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81.
In this Letter, we have introduced a technique, new to our knowledge, to fabricate gratings on a waveguide of azo-functionalized polymeric films using a slit mask and a fast, direct-writing method. To prevent the destruction of the waveguide by the grating formation on the waveguide, we placed a slit mask on the waveguide. By properly adjusting the resonance, this grating can be used as an integrated wavelength filter. We have produced an attenuation of 13.4?dB at 1562?nm with a FWHM of 3.45?nm. The grating has been fabricated as narrow as the width of the waveguide to couple filtered light into the waveguide by using a slit mask. Any light shifted from the resonance will pass through the waveguide undisturbed. 相似文献
82.
Osama Saber Mostafa Osama Nagih M. Shaalan Aya Osama Adil Alshoaibi Doaa Osama 《Molecules (Basel, Switzerland)》2022,27(12)
Energy and water related problems have attracted strong attention from scientists across the world because of deficient energy and water pollution. Following this line, new strategy depended on preparing nanolayers of Al/Zn and magnetic nanoparticles of cobalt iron oxides nanocomposite in addition to long chains of hydrocarbons of stearic acid to be used as roofs, fillers and pillars; respectively, to design optical-active nanohybrids in sunlight for removing the colored pollutants from water in few minutes. By using long chains of hydrocarbons of stearic acid, X-ray diffraction (XRD) results and TEM images showed expansion of the interlayered spacing from 0.76 nm to 2.02 nm and insertion of magnetic nanoparticles among the nanolayers of Al/Zn. The optical properties and activities showed that the nanohybrid structure based on zinc oxide led to clear reduction of the band gap energy from 3.3 eV to 2.75 eV to be effective in sunlight. Photocatalytic degradation of the dye of acid green 1 confirmed the high activity of the prepared zinc oxide nanohybrids because of a complete removal of the dye after ten minutes in sunlight. Finally, this strategy was effective for producing photo-active nanohybrids for using renewable and non-polluting energy for purifying water. 相似文献
83.
Shakri Natasa Mohd Salleh Wan Mohd Nuzul Hakimi Wan Khamis Shamsul 《Chemistry of Natural Compounds》2021,57(6):1114-1115
Chemistry of Natural Compounds - 相似文献
84.
Igor Linkov Jeffery Steevens Gitanjali Adlakha-Hutcheon Erin Bennett Mark Chappell Vicki Colvin J. Michael Davis Thomas Davis Alison Elder Steffen Foss Hansen Pertti Bert Hakkinen Saber M. Hussain Delara Karkan Rafi Korenstein Iseult Lynch Chris Metcalfe Abou Bakr Ramadan F. Kyle Satterstrom 《Journal of nanoparticle research》2009,11(3):513-527
Nanomaterials and their associated technologies hold promising opportunities for the development of new materials and applications
in a wide variety of disciplines, including medicine, environmental remediation, waste treatment, and energy conservation.
However, current information regarding the environmental effects and health risks associated with nanomaterials is limited
and sometimes contradictory. This article summarizes the conclusions of a 2008 NATO workshop designed to evaluate the wide-scale
implications (e.g., benefits, risks, and costs) of the use of nanomaterials on human health and the environment. A unique
feature of this workshop was its interdisciplinary nature and focus on the practical needs of policy decision makers. Workshop
presentations and discussion panels were structured along four main themes: technology and benefits, human health risk, environmental
risk, and policy implications. Four corresponding working groups (WGs) were formed to develop detailed summaries of the state-of-the-science
in their respective areas and to discuss emerging gaps and research needs. The WGs identified gaps between the rapid advances
in the types and applications of nanomaterials and the slower pace of human health and environmental risk science, along with
strategies to reduce the uncertainties associated with calculating these risks. 相似文献
85.
We consider the problem of the minimum number of Hamiltonian cycles that could be present in a Hamiltonian maximal planar graph on p vertices. In particular, we construct a p-vertex maximal planar graph containing exactly four Hamiltonian cycles for every p ≥ 12. We also prove that every 4-connected maximal planar graph on p vertices contains at least p/(log2 p) Hamiltonian cycles. 相似文献
86.
87.
Schrand AM Huang H Carlson C Schlager JJ Omacr Sawa E Hussain SM Dai L 《The journal of physical chemistry. B》2007,111(1):2-7
Finely divided carbon particles, including charcoal, lampblack, and diamond particles, have been used for ornamental and official tattoos since ancient times. With the recent development in nanoscience and nanotechnology, carbon-based nanomaterials (e.g., fullerenes, nanotubes, nanodiamonds) attract a great deal of interest. Owing to their low chemical reactivity and unique physical properties, nanodiamonds could be useful in a variety of biological applications such as carriers for drugs, genes, or proteins; novel imaging techniques; coatings for implantable materials; and biosensors and biomedical nanorobots. Therefore, it is essential to ascertain the possible hazards of nanodiamonds to humans and other biological systems. We have, for the first time, assessed the cytotoxicity of nanodiamonds ranging in size from 2 to 10 nm. Assays of cell viability such as mitochondrial function (MTT) and luminescent ATP production showed that nanodiamonds were not toxic to a variety of cell types. Furthermore, nanodiamonds did not produce significant reactive oxygen species. Cells can grow on nanodiamond-coated substrates without morphological changes compared to controls. These results suggest that nanodiamonds could be ideal for many biological applications in a diverse range of cell types. 相似文献
88.
A highly sensitive impedimetric immunosensor based on a gold nanoparticles/multiwall carbon nanotube-ionic liquid electrode (AuNPs/MW-CILE) was developed for the determination of human epidermal growth factor receptor 2 (HER2). Gold nanoparticles were used to enhance the extent of immobilization and to retain the immunoactivity of the antibody Herceptin on the electrode. Cyclic voltammetry and electrochemical impedance spectroscopy were employed for characterization of various layers coated onto the AuNPs/MW-CILE. The impedance measurements at different steps were based on the charge transfer kinetics of the [Fe(CN)6]3−/4− redox pair. The immobilization of antibody and the corresponding antigen–antibody interaction at the electrode surface altered the interfacial electron transfer. The interactions of antibody with various concentrations of antigen were also monitored via the change of impedance response. The results showed that the charge transfer resistance increases linearly with increasing concentrations of HER2 antigen. The linear range and limit of detection were found as 10–110 ng mL−1 and 7.4 ng mL−1, respectively. The sensitivity and specificity of the immunosensor were validated. The results showed that the prepared immunosensor is a useful tool for screening of trace amounts of HER2 in serum samples of breast cancer patients. 相似文献
89.
Many researchers have shown that plant-derived polyphenolic compounds are helpful nutraceuticals in restraining various disorders such as neoplastic diseases. In this study two linear furanocoumarins, aviprin and aviprin-3″-O-D-glucopyranoside (A3G), were isolated from methanol extract of Prangos uloptera roots. The evaluation of free radical scavenging capacity of the compounds showed that aviprin is a more effective antioxidant than A3G with RC50 of 0.54?mg?mL?1. The biological and antiproliferative activities of the furanocoumarins were examined using human cervical carcinoma HeLa cell line and LNCaP prostatic cell line. Cell membrane integrity and cell viability were evaluated by measuring trypan blue exclusion assay and reduction of the tetrazolium blue compound, respectively. Treating the LNCaP cell line with various concentrations of the furanocoumarins showed that IC?? of aviprin and A3G were 0.4 and 6.6?mg?mL?1, whereas their CC50 values were 0.7 and 11?mg?mL?1, respectively. These results indicated that 42.7% of LNCaP cells were not dead by necrosis. Treating the HeLa cells by the furanocoumarins showed the greater sensitivity of the HeLa cell line than the LNCaP cell line. A morphological analysis and the study of DNA fragmentation provided further some evidence for the inhibition of the LNCaP cell line via apoptosis induction. 相似文献
90.
Saber M. Elsayed Ruhul A. Sarker Daryl L. Essam 《Computational Optimization and Applications》2013,54(3):771-790
A considerable number of differential evolution variants have been proposed in the last few decades. However, no variant was able to consistently perform over a wide range of test problems. In this paper, propose two novel differential evolution based algorithms are proposed for solving constrained optimization problems. Both algorithms utilize the strengths of multiple mutation and crossover operators. The appropriate mix of the mutation and crossover operators, for any given problem, is determined through an adaptive learning process. In addition, to further accelerate the convergence of the algorithm, a local search technique is applied to a few selected individuals in each generation. The resulting algorithms are named as Self-Adaptive Differential Evolution Incorporating a Heuristic Mixing of Operators. The algorithms have been tested by solving 60 constrained optimization test instances. The results showed that the proposed algorithms have a competitive, if not better, performance in comparison to the-state-of-the-art algorithms. 相似文献