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81.
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
82.
Saeedi Mina Raeisi-Nafchi Maryam Sobhani Sepideh Mirfazli Seyedeh Sara Zardkanlou Mahsa Mojtabavi Somayeh Faramarzi Mohammad Ali Akbarzadeh Tahmineh 《Molecular diversity》2021,25(4):2399-2409
Molecular Diversity - In this work, various imidazo[1,2-a]pyridines linked to carbamate moiety were designed, synthesized, and evaluated for their α-glucosidase inhibitory activity. Among... 相似文献
83.
In this work, two different maximum likelihood approaches for multivariate curve resolution based on maximum likelihood principal component analysis (MLPCA) and on weighted alternating least squares (WALS) are compared with the standard multivariate curve resolution alternating least squares (MCR‐ALS) method. To illustrate this comparison, three different experimental data sets are used: the first one is an environmental aerosol source apportionment; the second is a time‐course DNA microarray, and the third one is an ultrafast absorption spectroscopy. Error structures of the first two data sets were heteroscedastic and uncorrelated, and the difference between them was in the existence of missing values in the second case. In the third data set about ultrafast spectroscopy, error correlation between the values at different wavelengths is present. The obtained results confirmed that the resolved component profiles obtained by MLPCA‐MCR‐ALS are practically identical to those obtained by MCR‐WALS and that they can differ from those resolved by ordinary MCR‐ALS, especially in the case of high noise. It is shown that methods that incorporate uncertainty estimations (such as MLPCA‐ALS and MCR‐WALS) can provide more reliable results and better estimated parameters than unweighted approaches (such as MCR‐ALS) in the case of the presence of high amounts of noise. The possible advantage of using MLPCA‐MCR‐ALS over MCR‐WALS is then that the former does not require changing the traditional MCR‐ALS algorithm because MLPCA is only used as a preliminary data pretreatment before MCR analysis. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
84.
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
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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
86.
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
87.
Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives 下载免费PDF全文
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
88.
Geometrical characterizations are given for the tensor R⋅S, where S is the Ricci tensor of a (semi-)Riemannian manifold (M,g) and R denotes the curvature operator acting on S as a derivation, and of the Ricci Tachibana tensor ∧g⋅S, where the natural metrical operator ∧g also acts as a derivation on S. As a combination, the Ricci curvatures associated with directions on M, of which the isotropy determines that M is Einstein, are extended to the Ricci curvatures of Deszcz associated with directions and planes on M, and of which the isotropy determines that M is Ricci pseudo-symmetric in the sense of Deszcz. 相似文献
89.
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
90.