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911.
Ali Firoozichahak Abdulrahman Bahrami Farshid Ghorbani Shahna Saber Alizadeh Davood Nematollahi Maryam Farhadian 《Journal of separation science》2020,43(5):1011-1018
We developed a novel method of needle trap device packed with titanium‐based metal‐organic framework for the extraction of phenolic derivatives in air followed by gas chromatography‐flame ionization detector analysis. The synthetized adsorbent was packed inside a 22‐gauge spinal needle. This method was first tested at laboratory scale, and then was used for field sampling of phenolic derivatives in air. A glass chamber placed on a heater at 60°C was used to provide different concentrations of phenolic derivatives. The desorption conditions and breakthrough volume were optimized using response surface methodology. The limit of detection and limit of quantitation of the proposed method were estimated to be in the range of 0.001–0.12 and 0.003–0.62 ng/mL, respectively, indicating a high sensitivity for the suggested sampler. Storing the packed needle trap device in a refrigerator at 4?C for 60 days did not dramatically affect the storage stability. Our findings indicated that there was a high correlation coefficient (R2 = 0.99) between the measurement results of this method and the NIOSH recommended method (XAD‐7 sorbent tube). Therefore, it can be concluded that the needle trap device packed with titanium‐based metal‐organic framework can be used as a efficient method for extraction of phenolic derivatives in air. 相似文献
912.
Maryam Arsalanfar Mahdi Fatemi Nima Mirzaei Majid Abdouss Esmaeil Rezazadeh 《中国化学会会志》2020,67(7):1152-1166
An investigation of the kinetic and mechanism of CO hydrogenation reaction was performed on impregnated Co-Ni/Al2O3. Determination of kinetic parameters from the experiments was carried out in a micro fixed-bed reactor. Kinetic evaluations were performed under various operational conditions of T = 473–673 K, p = 1–14 bar, H2/CO = 1–3, and GHSV = 4,500 hr−1. Kinetic models and rate equations for CO consumption were obtained by using two main-type rate equations of Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (ER). Estimation of various kinetic parameters was performed using a nonlinear regression method. According to the obtained experimental results and using statistical criteria, one kinetic expression based on the LHHW mechanism (-rCO = kp.bCO.PCO. bH2. PH2/[1+ bCO.PCO + bH2.PH2]2) was chosen as the best-fitted model. For this fitted model, the activation energy was found to be 109.2 kJ/mol. Characterization of the catalyst was also performed using X-ray diffraction (XRD), BET, scanning electron microscopy (SEM), and energy-dispersive x-ray spectrometer (EDS) techniques. 相似文献
913.
Maryam Mohammadi-Khanaposhtani Hoda Yahyavi Somaye Imanparast Fereshte Nazemi Harandi Mohammad Ali Faramarzi Alireza Foroumadi Bagher Larijani Mahmood Biglar Mohammad Mahdavi 《中国化学会会志》2020,67(5):856-863
Benzoylquinazolinone derivatives 3a–n were synthesized via a simple one-step reaction, and evaluated for in vitro α-glucosidase inhibitory activity. Compounds 3d , 3f–g , 3i , and 3m–n showed more inhibitory activity than standard drug acarbose (IC50 = 750.0 ± 1.5 μM), and among them, compound 3d displayed the highest α-glucosidase inhibitory activity (IC50 = 261.6 ± 0.1 μM). The kinetic analysis of the compound 3d revealed that this compound inhibited α-glucosidase in a competitive manner (Ki = 255 μM). The docking studies were applied to predict binding modes of the synthesized compounds in active site of α-glucosidase. 相似文献
914.
Mohammad Ali Karimi Maryam Iliyat Mojdeh Atashkadi Mehdi Ranjbar Aziz Habibi-Yangjeh 《中国化学会会志》2020,67(11):2032-2041
The preparation and photocatalytic performance of the Fe2O3/g-C3N4 nanocomposites with different weight percentage of iron was investigated in this study. Samples were successfully synthesized using melamine and ferric nitrate as the precursors via the green and facile microwave-assisted method. The physicochemical and structural properties of the Fe2O3-doped g-C3N4 were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), the Brunauer–Emmett–Teller (BET) method, transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and ultraviolet–visible spectroscopy (UV–Vis). The photocatalytic activity of the Fe2O3/g-C3N4 catalysts was evaluated by the degradation of methylene blue (MB) at room temperature under visible light irradiation. As expected, the as-synthesized samples exhibited considerable improvement in the photodegradation of MB. The Fe2O3/g-C3N4 (1.0 wt%) nanocomposite had superior photocatalytic activity, with almost 70% degradation efficiency within 90 min of irradiation. The enhanced performance was ascribed to the separation and migration of the photoinduced electron–hole pairs and taking part of the charge carriers in the chemical redox reactions at the surface of the photocatalyst. In this work, the effect of Fe weight percentage on the degradation potential was also studied, and the photocatalytic mechanism was proposed with the main reactive species •OH. 相似文献
915.
Maryam Kargar Karkhah Hassan Kefayati Shahab Shariati 《Journal of heterocyclic chemistry》2020,57(12):4181-4191
Fe3O4 magnetic nanoparticles were synthesized and functionalized by propylsilan and after that arginine. The synthesized Fe3O4@PS-Arginine magnetic nanoparticles were modified to obtain Fe3O4@PS-Arg[HSO4]. These nanoparticles were used as environmental friendly solidacid magnetic nanocatalyst for the synthesis of 2-amino-4-arylbenzo[h]quinoline-3-carbonitrile and 10,10-dimethyl-7-aryl-9,10,11,12-tetrahydrobenzo[c]acridin-8(7H)-one derivatives via the one-pot reaction of α-naphthilamine and aromatic aldehydes with malononitrile or dimedone. Simple operation, high reaction yields, reusability of catalyst for several times, short reaction time and easy separation from reaction mixture are the key advantages of using this catalyst. 相似文献
916.
Three‐component One‐pot Synthetic Route to Functionalized N‐Phenyl‐ and N,N‐(1,4‐phenylene)‐2‐alkylimino‐2,3‐dihydrothiazoles under Mild,Solvent‐ and Catalyst‐free Conditions
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A simple and efficient one‐pot synthesis of alkyl‐2‐(alkylimino)‐4‐methyl‐3‐phenyl‐2,3‐dihydrothiazole‐5‐carboxylate and dialkyl 3,3′‐(1,4‐phenylene)‐bis‐[2‐(alkylimino)‐4‐methyl‐2,3‐dihydrothiazole‐5‐carboxylate] derivatives from the reaction of phenylisothiocyanate (and also 1,4‐phenylene diisothiocyanate) and primary alkylamines in the presence of 2‐chloro‐1,3‐dicarbonyl compounds is described. This new protocol has several advantages such as lack of necessity of the catalyst and solvent, good yields,mild conditions and short times for reaction. 相似文献
917.
Maryam Chalabi Fatemeh Khademi Reza Yarani Ali Mostafaie 《Applied biochemistry and biotechnology》2014,172(8):4025-4037
Actinidin, a member of the papain-like family of cysteine proteases, is abundant in kiwifruit. To date, a few studies have been provided to investigate the proteolytic activity and substrate specificity of actinidin on native proteins. Herein, the proteolytic activity of actinidin was compared to papain on several different fibrous and globular proteins under neutral, acidic and basic conditions. The digested samples were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and densitometry to assess the proteolytic effect. Furthermore, the levels of free amino nitrogen (FAN) of the treated samples were determined using the ninhydrin colorimetric method. The findings showed that actinidin has no or limited proteolytic effect on globular proteins such as immunoglobulins including sheep IgG, rabbit IgG, chicken IgY and fish IgM, bovine serum albumin (BSA), lipid transfer protein (LTP), and whey proteins (α-lactalbumin and β-lactoglobulin) compared to papain. In contrast to globular proteins, actinidin could hydrolyze collagen and fibrinogen perfectly at neutral and mild basic pHs. Moreover, this enzyme could digest pure α-casein and major subunits of micellar casein especially in acidic pHs. Taken together, the data indicated that actinidin has narrow substrate specificity with the highest enzymatic activity for the collagen and fibrinogen substrates. The results describe the actinidin as a mild plant protease useful for many special applications such as cell isolation from different tissues and some food industries as a mixture formula with other relevant proteases. 相似文献
918.
Emna Chichti Matthieu George Jean-Yves Delenne Farhang Radjai Valérie Lullien-Pellerin 《European Polymer Journal》2013
An original method based on atomic force microscopy (AFM) in contact mode was developed to abrade progressively the surface of tablets made of starch or gluten polymers isolated from wheat. The volume of the material removed by the tip was estimated from the analysis of successive topographic images of the surface, and the shear force was measured by keeping a constant normal force. Our data together with a simple tribological model provide clear evidence for a higher hardness and shear strength of starch compared to gluten. Gluten appears to have mechanical properties close to soft materials, such as talc, whereas starch displays higher hardness close to calcite. Our results are in a better agreement with structural properties of gluten (complex protein network) and starch (granular and semi-cristalline structure) than earlier studies by micro-indentation. This work shows that the AFM scratching method is relevant for the characterization of any polymer surface, in particular in application to materials made of different polymers at the nano-scale. 相似文献
919.
A regioselective and highly efficient method for bromination of phenol and aniline derivatives using ethylenebis(N-methylimidazolium) ditribromide (EBMIDTB) as an efficient reagent in dichloromethane at ambient temperature is reported. The reagent can be recovered and reused several times. 相似文献
920.
Firouz Matloubi Moghaddam Ghasem Rezanejade Bardajee Hossein Ismaili Seyedeh Maryam Dokht Taimoory 《合成通讯》2013,43(17):2543-2548
Rapid and efficient condensation reactions of 2‐aminothiophenol and 2‐aminophenol with various aldehydes were carried out using I2 in solvent‐free conditions with or without microwave irradiation to afford the corresponding 2‐substituted benzothiazole and benzoxazole derivatives in good to excellent yields. 相似文献