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81.
In the present work, Cu@KCC-1-NH-CS2 as a green, efficient, and reusable nano-reactor was designed and used for the one-pot, three-component synthesis of 2-amino-4H-chromene derivatives using the reaction of cyclic 1,3-diketones, arylglyoxals, and malononitrile, under reflux conditions in EtOH. Engineered nanocatalyst characterized using different methods including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), adsorption/desorption analysis (BET), and energy dispersive X-ray spectroscopy (EDS). According to the obtained results, presented protocol for the synthesis of 2-amino-4H-chromenes using Cu@KCC-1-NH-CS2 gave the desired products in higher yields (89–98%) with short reaction times. Also, under mild reaction conditions this green nanocatalyst indicated recyclable behavior five times with minor reduce in its catalytic activity. 相似文献
82.
We propose and analyze a novel photonic crystal pulse position modulator utilizing a coupled cavity waveguide delay line. Also, a nonlinear photonic crystal directional coupler is used as an all-optical switch in the proposed structure. The input data acts as the control signal of the switch and activates the switching operation. We show that the device size can be reduced significantly by designing the delay line to achieve a reduced group velocity and a quasi-flat impurity band. The size of the designed modulator is 32a × 16a, where a represents the lattice constant of the photonic crystal. The characteristics of the device are investigated by finite-difference time-domain (FDTD) and plane wave expansion (PWE) methods. 相似文献
83.
Fluorescence imaging of intrinsic fluorophores of tissue is a powerful method to assess metabolic changes at the cellular and intracellular levels. At the same time, exogenous phosphorescent probes can be used to accurately measure intravascular tissue oxygenation. Heart failure is the leading cause of death in America. A rat heart can potentially model the human heart to study failures or other abnormalities optically. We report simultaneous fluorescence and phosphorescence measurements performed on a rat heart. We have used two different optical systems to acquire fluorescence signals of flavoprotein and nicotinamide adenine dinucleotide--the two intrinsic fluorophores of mitochondria--and the phosphorescence signal of an intravascular oxygen probe to extract intracellular and intravascular metabolism loads, respectively. 相似文献
84.
Bakherad Mohammad Moosavi Fatemeh Keivanloo Ali Doosti Rahele Moradian Elmira Armaghan Mahsa 《Research on Chemical Intermediates》2019,45(5):2981-2997
Research on Chemical Intermediates - In this work, magnetized water is applied as a green-promoting medium for the catalyst-free, one-pot, practical, efficient, and environmentally benign... 相似文献
85.
Mahsa Ghasri Arash Jahandideh Kourosh Kabiri Hossein Bouhendi Mohammad J. Zohuriaan‐Mehr Nasrin Moini 《先进技术聚合物》2019,30(2):390-399
The glycerol‐lactic acid‐based star‐shaped modifier (SM) were synthesized and employed for surface modification of hygienic superabsorbent polymer (SAP) hydrogels for the first time. Surface crosslinking was carried out to increase the saline‐absorbency under load (AUL) and the swollen gel strength. The surface treatment process was analyzed employing free absorbency and AUL tests, salt sensitivity, attenuated total reflectance‐Fourier‐transform infrared spectroscopy (ATR‐FTIR), oscillatory rheometry, as well as scanning electron microscopy analysis. The effect of the branched architecture and the contents of SM on the properties of the modified SAPs were studied. The implementation of surface treatment leads to increase up to a 28% in the AUL of the modified SAP. Moreover, the loss modulus was surprisingly increased, while the storage modulus was enhanced (possibly due to the star architecture of oligomers). Mc and crosslink density values have been estimated based on modified rubber elasticity theory. Salt sensitivity factor (f) was calculated; the modified samples showed lower salt sensitivity in NaCl (f = 0.7) and CaCl2 (f = 0.93–0.95) compared with the intact SAP (f = 0.84 for NaCl, and f = 0.95–0.97 for CaCl2). 相似文献
86.
Armaghan Shafaei Kevin Croft Jonathan Hodgson Mary C. Boyce 《Journal of separation science》2019,42(18):2909-2921
A diet rich in polyphenolic compounds has recognized health benefits, and as such is routinely monitored as part of dietary intervention studies. A method for the simultaneous determination of 36 phenolic compounds, including phenolic acids and flavonoids, using liquid chromatography and tandem mass spectrometry is described here. The target analytes were quantified based on their specific mass spectral fragments using a selected reaction monitoring approach. A C18 column with embedded aromatic functionality ensured separation of all phenolic compounds studied which included several pairs of isomers. Sample preparation involved the use of β‐glucuronidase to release the phenolic compounds from their conjugated forms. The intra‐day and inter‐day precision and accuracy was less than 7% for all phenolic compounds studied. Recoveries, where plasma was spiked with three different concentrations of the analytes, ranged from 95–115%. The limits of detection and quantification were 0.23–3.89 and 1.15–7.79 nM, respectively. The method was successfully applied to real samples and the range reported for each phenolic compound, with the exception of hydroferulic acid, nordihydroguaiaretic acid, methylgallate, and m‐coumaric acid, was at least an order of magnitude higher than the limit of quantification for the method. 相似文献
87.
Ahadi Najmieh Mobinikhaledi Akbar Fathehesami Armaghan Bagheri Zahra 《Research on Chemical Intermediates》2022,48(6):2469-2488
Research on Chemical Intermediates - In the present work, a novel Zn salen complex supported on MnCoFe2O4 magnetic nanoparticles, MnCoFe2O4@SiO2-Pr-NH-SA&Zn (MCF@SiO2-Pr-NH-SA&Zn)... 相似文献
88.
Mahsa Majidian Jahan Bakhsh Raoof Sayed Reza Hosseini Reza Ojani 《Journal of the Iranian Chemical Society》2017,14(6):1263-1270
In this work, an antimony trioxide-modified multi-walled carbon nanotube paste electrode (Sb2O3/CNTPE) was employed for determination of Cu2+ ions by using square wave anodic stripping voltammetry (SWASV) in the presence of 8-hydroxy-7-iodo-5-quinoline sulfonic acid (HIQSA) as a chelating agent. The field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS) methods were applied to estimate the morphology and properties of the modified electrode. Measurements related to SWASV were taken in 0.6 M HCl at ?1.0 V versus Ag|AgCl|KCl (3 M) for 90 s (deposition step). After equilibrium time of 15 s, an ASV appeared at 0.0 V versus Ag|AgCl|KCl (3 M) (stripping step). The sensor depicted a fairly linear response for Cu2+ in the concentration range of 2–100 ppb with appropriate detection limit about 0.39 ppb and limit of quantification about 1.3 ppb. The stability of the modified electrode during 7 weeks and its behavior in the presence of some metal ions was evaluated. The practical applicability of the Sb2O3/CNTPE was established on the voltammetric determination of Cu2+ in tap water as a sample. 相似文献
89.
Sulfonic acid groups were grafted onto three different types of synthesized magnetic nanoparticles, namely Fe3O4, Fe3O4@SiO2, and Fe3O4@MCM‐48. The sulfonic acid‐functionalized nanoparticles were evaluated as catalysts for the synthesis of 5‐aryl‐1H‐benzo[f]chromeno[2,3‐d]pyrimidine‐2,4(3H,5H)‐dione derivatives in terms of activity and recyclability. Their catalytic activities were compared with that of the homogeneous acid catalyst 1‐methylimidazolium hydrogen sulfate ([HMIm][HSO4]). The activity of Fe3O4@MCM‐48–SO3H was comparable to those of the other heter‐ogeneous and homogeneous catalysts. 相似文献
90.
Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives
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Nasim Esmati Mahsa Foroughian Mina Saeedi Mohammad Mahdavi Mehdi Khoshneviszadeh Omidreza Firuzi Nader Tanideh Ramin Miri Najmeh Edraki Abbas Shafiee Alireza Foroumadi 《Journal of heterocyclic chemistry》2015,52(1):97-104
Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations. 相似文献