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11.
Yang Liu Dr. Yong Yu Jacky W. Y. Lam Dr. Yuning Hong Mahtab Faisal Wang Zhang Yuan Dr. Ben Zhong Tang Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(28):8433-8438
A handy, specific, sensitive bioprobe has been developed. Tetraphenylethene (TPE) was functionalized by a maleimide (MI) group, giving a TPE‐MI adduct that was nonemissive in both solution and the solid state. It was readily transformed into a fluorogen showing an aggregation‐induced emission (AIE) property by the click addition of thiol to its MI pendant. The click reaction and the AIE effect enabled TPE‐MI to function as a thiol‐specific bioprobe in the solid state. Thus, the spot of TPE‐MI on a TLC plate became emissive when it had been exposed to L ‐cysteine, an amino acid containing a thiol group, but remained nonemissive when exposed to other amino acids that lack free thiol units. The thiol‐activated emission was rapid and strong, readily detected by the naked eye at an analyte concentration as low as approximately 1 ppb, thanks to the “lighting up” nature of the bioprobing process. Similarly, the emission of TPE‐MI was turned on only by the proteins containing free thiol units, such as glutathione. Clear fluorescence images were taken when living cells were stained by using TPE‐MI as a visualization agent, affording a facile fluorescent maker for mapping the distribution of thiol species in cellular systems. 相似文献
12.
Optical tweezers have proven to be very useful in various scientific fields, from biology to nanotechnology. In this Letter we show, both by theory and experiment, that the interference intensity pattern at the back focal plane of the condenser consists of two distinguishable areas with anticorrelated intensity changes when the bead is moved in the axial direction. We show that the space angle defining the border of two areas linearly depends on the NA of the objective. We also propose a new octant photodiode, which could significantly improve the axial resolution compared to the commonly used quadrant photodiode technique. 相似文献
13.
Synthesis of Novel and Thermally Stable Water Insoluble Coumarin‐based Azo Dyes via a Mild and Green Procedure 下载免费PDF全文
A series of novel azo coumarin dyes were synthesized by the diazotization of 7‐amino coumarins in the presence of catalytic amounts of tungstate sulfuric acid (TSA) followed by coupling with phenol derivatives. Tungstate sulfuric acid catalyzes this reaction at room temperature and short reaction time with high yields. 相似文献
14.
Synthesis of 5‐Amino‐3,3‐dimethyl‐7‐phenyl‐3H‐[1,2]oxathiolo[4,3‐b]pyridine‐6‐carbonitrile 1,1‐Dioxides 下载免费PDF全文
Mourad Chioua Abdelouahid Samadi Denis Postel Jan Balzarini José Marco‐Contelles 《Journal of heterocyclic chemistry》2014,51(5):1452-1456
The reaction of 4‐amino‐5,5‐dimethyl‐5H‐1,2‐oxathiole 2,2‐dioxide ( 1 ) with 2‐(arylidene)malononitriles 2 in ethanol, at reflux, using piperidine as catalyst, afforded 5‐amino‐3,3‐dimethyl‐7‐aryl‐3H‐[1,2]oxathiolo[4,3‐b]pyridine‐6‐carbonitrile 1,1‐dioxides ( 3 ) in moderate chemical yields. 相似文献
15.
Mahtab HejazifarSaeid Azizian Hassan SarikhaniQiang Li Dongyuan Zhao 《Journal of Analytical and Applied Pyrolysis》2011,92(1):258-266
Grapevine rhytidome (the outer layer of bark on trunk), as an abundant and low-cost precursor, was used to prepare granular activated carbon with high surface area for the removal of methyl violet from aqueous solution. Microwave heating source was used to reduce the treatment time and energy consumption. To optimize the preparation, the effects of the different parameters, such as phosphoric acid concentration, acid/precursor weight ratio, impregnation time, microwave power, radiation time, and oven heating time on the ability of the samples for removal of methyl violet were studied. The obtained activated carbon was characterized by N2 adsorption/desorption, SAXS, TEM and SEM methods. The adsorption of methyl violet onto the activated carbon was studied from both equilibrium and kinetic point of view and the results were compared with the commercial granular activated carbon. The rate of adsorption onto the prepared activated carbon was faster than commercial activated carbon. Different kinetic models were used to analyze the experimental kinetic data. The obtained activated carbon showed higher adsorption capacity (more than twice) for the adsorption of methyl violet in comparison with the commercial one. The equilibrium data were analyzed using different isotherm models. Adsorption was found to be maximum in the pH range 7-9. 相似文献
16.
An ionic liquid mediated sol-gel sorbents for hollow fiber solid-phase microextraction (HF-SPME) was developed for extraction of the pesticides: diazinon, fenitrothion, malathion, fenvalerate, phosalone and tridemorph from human hair and water samples. The analytes were subsequently analyzed with high performance liquid chromatography and diode array detection (HPLC-DAD). Preliminary experiments were carried out in order to study experimental conditions for pesticides' extraction from spiked hair and water samples with HF-SPME using hollow fiber-supported ionic liquid mediated sol-gel sorbent. The sol-gel nanocomposites were reinforced with nanoparticles such as carboxylic functionalized multi-walled carbon nanotubes (COOH-MWCNTs), amino functionalized multi-walled carbon nanotubes (NH(2)-MWCNTs), nano SiO(2), nano TiO(2) and nano MgO comparatively to promote extraction efficiency. In this device, the innovative solid sorbents were developed by the sol-gel method via the reaction of tetraethylorthosilicate (TEOS) with 2-amino-2-hydroxymethyl-propane-1,3-diol (TRIS). In the basic condition (pH 10-11), the gel growth process in the presence of ionic liquid and nanoparticles was initiated. Then, the sol was injected into a polypropylene hollow fiber segment for in situ gelation process. Parameters affecting the efficiency of HF-SPME were thoroughly investigated. Linearity was observed over a range of 0.01-25,000 ng/mL with detection limits between 0.004 and 0.095 ng/mL for the pesticides in the aqueous matrices and 0.003-0.080 ng/mL in the hair matrices. The relative recoveries in the real samples ranged from 82.0% to 94.0% for the pesticides store seller's hair and the work researchers' hair. Results are showing the great possibilities of HF-SPME-HPLC-PDA for analysis of pesticides in biological and environmental samples. 相似文献
17.
Reza Ranjbar-Karimi Mahtab Mashak-Shoshtari Reza Kia 《Journal of fluorine chemistry》2011,132(4):285-290
Bis-perfluoropyridyl bridged by 1,4 and 1,2 dihydropyridine compounds was synthesized by reaction of 2 and 4 aminopridine derivatives with pentafluoropyridine. The structures were determined by X-ray crystallography. Compound 3a comprises two crystallographically independent molecules in the asymmetric unit in which one of them shows 1-D infinite chains along [0 1 0] direction due to the intermolecular C-H?N hydrogen bonds. In compound 5 intermolecular C-H?F and C-H?N hydrogen bonds link neighbouring molecules to each other. In addition, in both structures a series of C-F?π interactions stabilize the crystal packing. 相似文献
18.
A method is described to solve constrained HFB-equations without introduction of a Lagrangian multiplier. To demonstrate the versatility of the method rotational bands in164Er and168Yb are calculated. 相似文献
19.
Samadi Morasae Zirak Mohammad Naseri Amene Kheirabadi Malihe Ebrahimi Mahdi Moshfegh Alireza Z. 《Research on Chemical Intermediates》2019,45(4):2197-2254
Research on Chemical Intermediates - Photocatalysis using semiconductors has emerged as a promising wastewater treatment process to overcome the major challenges faced by conventional technologies.... 相似文献
20.
Malihe Samadi Kazemi Elham Ataeei Malihe Nasrabadi 《Russian Journal of Electrochemistry》2016,52(10):975-982
The complexation reaction between Tl+, Ag+ and Pb2+ cations with 2,6-di(furyl-2yl)-4-(4-methoxy phenyl)pyridine as a new synthesis ligand in acetonitrile (ACN)–H2O and methanol (MeOH)–H2O binary solutions has been studied at different temperatures using conductometric method. The conductometric data show that the stoichiometry of the complexes is 1: 1 [M: L] and the stability constant of complexes changes with the binary solutions identity. Also, the structure of the resulting 1: 1 complexes was optimized using the LanL2dz basis set at the B3LYP level of theory using GAUSSIAN03 software. The results show that the change of logKf for (DFMP.Pb)2+ and (DFMP.Ag)+ complexes with the mole ratio of acetonitrile and for (DFMP.Ag)+ and (DFMP.Tl)+ complexes with the mole ratio of methanol have a linear behavior, while the change of logKf of (DFMP.Tl)+complex in ACN–H2O binary solutions (with a minimum in XACN = 0.5) and (DFMP.Ag)+ complex in MeOH–H2O binary solutions (with a minimum in XMeOH = 0.75) show a non-linear behavior. The selectivity order of DFMP ligand for these cations in mol % CAN = 25 and 75 obtain Tl+ > Pb2+ > Ag+ but in mol % CAN = 50, the selectivity order observe Pb2+ > Tl+ > Ag+. Also, this selectivity sequence of DFMP in MeOH–H2O (mol % MeOH = 75 and 100) and (mol % MeOH = 50) is obtained Pb2+ > Ag+ and Tl+ > Ag+ > Pb2+ respectively. The values of thermodynamic parameters show that these values are influenced by the nature and the composition of binary solution. In all cases, the resulting complexes are enthalpy stabilized and entropy destabilized. The TΔSC° versus ΔHC° plot of all obtained thermodynamic data shows a fairly good linear correlation which indicates the existence of enthalpy-entropy compensation in the complexation reactions. 相似文献