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91.
92.
Yue Dong Eser Metin Akinoglu Heyou Zhang Fatemeh Maasoumi Jinping Zhou Paul Mulvaney 《Advanced functional materials》2019,29(40)
Stimuli‐responsive optical etalons are an exciting class of next‐generation sensors because they are scalable, cost‐effective and offer tunability of their optical response across the entire UV–vis–NIR wavelength range. In this study, double‐network cellulose hydrogels are used as a soft, responsive medium and are incorporated into Fabry–Pérot optical etalons. The thin cellulose hydrogel layer can be solution processed. The hygroscopic hydrogel undergoes both refractive index and thickness changes in response to changes in humidity. This leads to strong changes in reflection due to optical interference within the metal–insulator–metal (MIM) cavity. The response can be optimized by adjusting the chemical crosslinker ratio. These flexible MIM structures provide a robust platform for optically based chemical sensors. 相似文献
93.
Gorji Marzban Anita Herndl Sara Pietrozotto Srijib Banerjee Christian Obinger Fatemeh Maghuly Rainer Hahn Donato Boscia Hermann Katinger Margit Laimer 《Food chemistry》2009
Mal d 2, a thaumatin-like protein from apple was previously described to react to almost 75% of the apple allergic patient sera. Based on the molecular structure of this protein, the present study focused on the conformational stability of Mal d 2 in relation to in vitro IgE-binding under different physico-chemical conditions and proteolysis. The structural integrity of Mal d 2 was monitored using SDS–PAGE, Western blotting using polyclonal antibodies and human sera, fluorescence spectrometry and circular dichroism. Results confirmed the stability of Mal d 2. However, Mal d 2 was reactive to human serum IgEs mainly after reduction of disulphide bridges fixing the α-helical domain II. Contrary to previous assumptions, the current findings suggest that the allergenic epitopes of Mal d 2 are hidden inside the protein structure and none of the rigorous conditions applied in industrial juice processing or digestive proteolysis enhance or reduce the binding to IgE molecules. 相似文献
94.
This paper describes a simple method based on three-phase hollow-fibre liquid-phase microextraction (HF-LPME) for the determination of phenolic acids in fruit juices. Analytes including gallic acid, p-hydroxy benzoic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and cinnamic acid were separated and determined using high-performance liquid chromatography–photodiode array detection (HPLC–DAD). Parameters affecting the enrichment factors (EFs) were investigated. These compounds were extracted from 5 mL aqueous samples (pH 2) to a thin layer of organic solvent (hexyl acetate) phase impregnated into the pores of the polypropylene hollow fibre wall, and then back extracted to a basic acceptor solution (0.02 M NaOH). EFs ranged from 15 (gallic acid) to 408 (cinnamic acid). The RSD of the method for the analysis of spiked water and fruit juice samples varied from 3.1% to 11.3%. The LODs ranged from 0.01 (cinnamic acid) to 2.0 (caffeic acid) μg/L. 相似文献
95.
A series of biopolymer‐based superabsorbent hydrogels based on carboxymethyl cellulose has been prepared by free‐radical graft copolymerization of acrylamide and 2‐acrylamido‐2‐methylpropan sulfonic acid (AMPS) in aqueous solution using methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator. The effect of variables on the swelling capacity such as: acrylamide/AMPS weight ratio, reaction temperature, and concentration of the initiator and crosslinker were systematically optimized. The results indicated that with increasing the amount of AMPS, the swelling capacity is increased. FT‐IR spectroscopy and scanning electron microscope analysis were used to confirm the hydrogel structure. Swelling measurements of the synthesized hydrogels in different salt solutions indicated considerable swelling capacity. The absorbency under load of the superabsorbent hydrogels was determined by using an absorbency under load tester at various applied pressures. A preliminary swelling and deswelling behaviors of the hydrogels were also studied. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
96.
Mehran Javanbakht Faten Divsar Fatemeh Fatollahi Mohammad Reza Ganjali Marzieh Chaloosi 《Electrochimica acta》2009,54(23):5381-5386
This study introduces the design of an anodic stripping voltammetric (ASV) method for the silver ion determination at a carbon paste electrode (CPE), chemically modified with phenylthiourea-nanoporous silica gel (Tu-SBA-15-CPE). The electroanalytical pro includes two steps: preconcentration of metal ions at an electrode surface, followed by quantification of the accumulated species by differential pulse anodic stripping voltammetric methods. Factors affecting the performance of the anodic stripping were investigated, including the modifier quantity in the paste, the electrolyte concentrations, the solution pH and the accumulation potential or time. The most sensitive and reliable electrode contained 10% Tu-SBA-15 and 90% carbon paste. The accumulation potential and time were set at, −200 mV and 300 s, respectively, and the scan rate at 50 mV s−1 in the scan range of −200 to 700 mV. The resulting electrode demonstrated a linear response over range of silver ion concentration of 8.0-80 pmol/L with detection limit (S/N = 3) of 5 pmol/L. The prepared electrodes were used for the silver determination in sea and tap water samples and very good recovery results were obtained. The accuracy was assessed through recovery experiments and independent analysis by graphite furnace atomic absorption spectrometry. 相似文献
97.
Behrooz Maleki Fatemeh Barakchi Tabrizy Reza Tayebee Mehdi Baghayeri 《Polycyclic Aromatic Compounds》2019,39(2):93-98
Oxidative aromatization of 1,3,5-trisubstituted 2-pyrazolines by in-situ generation of NO+ from oxalic acid/sodium nitrite system has been described. The main advantages of this procedure are the use of an inexpensive and readily available catalyst, facile work-up, and improved yields in aqueous ethanol. 相似文献
98.
Fatemeh Hosseinzadeh Hossein Sarpoolaky 《International Journal of Applied Ceramic Technology》2019,16(4):1544-1556
Taguchi method (TM) and response surface methodology (RSM) have been employed to optimize three parameters, including the amounts of P123, the amounts of nitric acid and calcination temperature, in order to define an optimal setting for sol-gel synthesis of high surface area mesoporous alumina powder (MA). Herein, the comparison of the both statistical approaches has been examined and discussed considering the nitrogen adsorption as the response variable because this important character for mesoporous materials is exceedingly sensitive to the synthesis parameters. The BET surface area (SBET) and pore volume of MA under Taguchi optimal condition were 323.5 m2 g−1 and 0.551 cm3 g−1, respectively, by conducting confirmation test. Furthermore, the confirmation test showed high SBET of MA (363.4 m2 g−1), which was in a good agreement with calculated SBET result (431.25 m2 g−1) by a quadratic model under RSM optimal condition. Moreover, 3D response surface plots and 2D contour plots of desirability have been discussed to visualize the influence of input factors on response variable. It is also concluded that RSM shows more appropriate (12.33% higher SBET than TM) and efficient optimal condition with determining a quadratic function as the relationship between SBET and synthesis parameters. 相似文献
99.
Controlled Preparation and Characterization of Nigella Sativa Electrospun Pad for Controlled Release
Kalhori Fatemeh Arkan Elham Dabirian Farzad Abdi Gisya Moradipour Pouran 《SILICON》2019,11(2):593-601
Silicon - Nigella sativa (NS) oil is an anti-inflammatory agent in the traditional medicine. In the present study, novel electrospun mats contained NS oil/polyacrylonitrile as a sustained release... 相似文献
100.
Shima Ghaffari Maryam Yousefzadeh Fatemeh Mousazadegan 《Polymer Engineering and Science》2019,59(10):2032-2040
The development of functional nanofiber materials with high specific surface area and porosity has been a highly interesting field of research in recent years due to its versatile properties for diverse applications. The combination of nanofibers into material clothes can open up new opportunities to improve comfort performance and thermal management properties. In this work, we demonstrated that the porous lightweight nanofibrous membrane could be coated on the fabric and laminated to improve its thermal comfort. The polyacrylonitrile was electrospun onto the surface of the polyester fabric with three different fineness and laminated with a warp knitted interlining in a controlled condition by sewing/fusing. The effect of the nanofibers diameter, sewing and fusing process on thermal insulation, air permeability, breathability, and water resistance of the obtained three‐layer samples were studied. The results showed that the presence of the nanofibers thin layer could improve the thermal comfort by controlling the studied parameters compared to the external face fabric as control. It was obtained that the fusing technique is more efficient than sewing for this purpose. The fused samples are waterproof and windproof, while instantly venting moisture and had good thermal insulation to protect the body from cold. POLYM. ENG. SCI., 59:2032–2040, 2019. © 2019 Society of Plastics Engineers 相似文献