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排序方式: 共有93条查询结果,搜索用时 15 毫秒
71.
Barnali Naskar Dr. Anamika Dhara Prof. Dilip K. Maiti Mercedes Kukułka Prof. Mariusz P. Mitoraj Dr. Monika Srebro-Hooper Chandraday Prodhan Prof. Keya Chaudhuri Dr. Sanchita Goswami 《Chemphyschem》2019,20(12):1630-1639
Fluorescent chemosensors with aggregation induced emission enhancement (AIEE) emerge as promising tools in the field of sensing materials. Herein, we report the design, synthesis and applicability of a Schiff base chemosensor 1-(benzo[1,3]dioxol-4-ylmethylene-hydrazonomethyl)-naphthalen-2-ol ( Hbdhn ) of AIE characteristics that exhibits highly effective and selective response towards Zn2+. The sensing effect of Hbdhn was evaluated by means of absorption/emission spectra and corresponding underlying photophysical mechanisms were proposed based on extensive quantum-chemical (TD)DFT calculations. The aggregated states in different DMSO/H2O ratios and in a presence of Zn2+ were examined by fluorescence lifetime measurements, dynamic light scattering and scanning electron microscopy studies. The bioimaging abilities of Hbdhn were evaluated for Zn2+ in HepG2 cancer cells. The results demonstrate instant, stable in time and reproducible, colorimetric turn-on response with superb selectivity and sensitivity of Hbdhn towards Zn2+, based on chelation enhanced fluorescence mechanism. AIEE improves further Hbdhn properties, leading to strong, long-lived fluorescence, with appearance of rod-like particles, in 90 % of water in DMSO and only 10 % of water in DMSO in the presence of Zn2+. All these features combined with successful biomaging studies make Hbdhn one of the most promising candidate for practical applications among recently proposed related systems. 相似文献
72.
73.
P. S. Bassi B. S. Randhawa C. M. Khajuria Sandeep Kaur 《Journal of Thermal Analysis and Calorimetry》1987,32(2):569-577
The thermal decompositions of maleates and fumarates of Cu(II) and Zn(II) have been studied by employing simultaneous non-isothermal techniques (DTG, DTA and TG). The end-products are the corresponding metal oxides, as characterized by chemical analysis and X-ray diffraction. Comparison of theTm values led to the stability sequences Cu(F)>Cu(M); Zn(F)>Zn(M) and Cu(M)≈ Cu(F); Zn(F)>Zn(M) for dehydration and decomposition, respectively. 相似文献
74.
We investigated the temperature dependence of the splay elastic constant (K11) and rotational viscosity (γ1) of a binary liquid crystal system comprising 5-trans-n-butyl-2-(4-isothiocyanatophenyl)-1,3-dioxane (4DBT) and 4-cyano-4′-n-undecyloxy-biphenyl (11OCB), exhibiting induced nematic phase. Both the splay elastic constant and rotational viscosity increased following lowering of the temperature. In the vicinity of smectic A-nematic (SmA-N) transition, both the relaxation time and rotational viscosity exhibited a strong pretransitional behaviour. The critical exponent (ν) presented here led to valuable qualitative information about the pre-transitional behaviour of the rotational viscosity data near the SmA-N phase transition. The extracted ν values ranging between 0.336 and 0.352 are in fair agreement with those predicted in the de Gennes model as compared to that by the mean-field model. 相似文献
75.
Ashok K.S. Chauhan Anamika Ramesh C. Srivastava Jens Beckmann Andrew Duthie 《Journal of organometallic chemistry》2005,690(5):1350-1355
The unsymmetrically substituted diorganotellurium dihalides [2-(4,4′-NO2C6H4CHNC6H3Me]RTeX2 (R = 4-MeOC6H4, X = Cl, 1a; Br, 1b; I, 1c; R = 4-MeC6H4; X = Cl, 2; R = C6H5, X = Cl, 3) were prepared in good yields and characterized by solution and solid-state 125Te NMR spectroscopy, IR spectroscopy and X-ray crystallography. In the solid-state, molecular structures of 1a and 1c possess scarcely observed 1,4-type intramolecular Te?N secondary interaction. Crystal packing of these compounds show an unusually rich diversity of intermolecular secondary, Te?O, Te?I and I?I interactions, Te?π contacts as well as extensive π-stacking of the organic substituents. 相似文献
76.
Azizah M. Malebari Rakia Abd Alhameed Zainab Almarhoon Muhammad Farooq Mohammad A. M. Wadaan Anamika Sharma Beatriz G. de la Torre Fernando Albericio Ayman El-Faham 《Molecules (Basel, Switzerland)》2021,26(4)
Several derivatives containing morpholine/piperidine, anilines, and dipeptides as pending moieties were prepared using s-triazine as a scaffold. These compounds were evaluated for their anticancer activity against two human breast cancer cell lines (MCF-7 and MDA-MB-231), a colon cancer cell line (HCT-116), and a non-tumorigenic cell line (HEK 293). Tamoxifen was used as a reference. Animal toxicity tests were carried out in zebrafish embryos. Most of these compounds showed a higher activity against breast cancer than colon cancer. Compound 3a—which contains morpholine, aniline, and glycylglycinate methyl ester—showed a high level of cytotoxicity against MCF-7 cells with IC50 values of less than 1 µM. This compound showed a much lower level of toxicity against the non-tumorigenic HEK-293 cell line, and in the in vivo studies using zebrafish embryos. Furthermore, it induced cell cycle arrest at the G2/M phase, and apoptosis in MCF-7 cells. On the basis of our results, 3a emerges as a potential candidate for further development as a therapeutic drug to treat hormone receptor-positive breast cancer. 相似文献
77.
Khajuria RK Bhardwaj V Gupta RK Sharma P Somal P Mehta P Qazi GN 《Journal of chromatographic science》2007,45(8):519-523
This paper describes the development of a normal-phase liquid chromatograph-UV-diode array detection-positive ion atmospheric pressure chemical ionization-mass spectrometry method for the simultaneous identification and quantitation of cholesterol, androst-4-ene-3,17-dione (AD), and androsta-1,4-diene-3,17-dione (ADD) in fermentation broths. The compounds detected under positive ion atmospheric pressure chemical ionization on a mass spectrometer by selected ion monitoring are separated by normal-phase high-performance liquid chromatography. [M+H]+ ions are taken into consideration for quantitation of AD and ADD, and [M-H2O+H]+ ions are considered for quantitation of cholesterol. The compounds are analyzed on a Si60 silica (5 microm, 125 x 4-mm i.d.) Merck column using a 2:3 isocratic mixture of isopropyl alcohol and hexane. The calibration curves resulting from the reference compounds in the concentration range of 100-5000 pg on column exhibit a good linear correlation (r2 > or = 0.996). The method is validated by analyzing six replicates of broth samples fortified with three compounds, namely, cholesterol, AD, and ADD, at 0.050 and 0.5 microg/g levels. The mean recoveries for the fortifications range from 90% to 98% with relative standard deviations in the range of 3.36% to 9.78%. The method is developed to study the qualitative as well as quantitative conversion of cholesterol to AD and ADD by a microorganism identified as Nocardia sp. These studies helped the investigation of the reaction kinetics, which showed that the molar biotransformation of cholesterol into AD and ADD was 21%, even when the reaction was prolonged for 96 h. 相似文献
78.
One‐pot oxidation of aromatic and cyclic hydrocarbons using the Au (III) and Pd (II) catalyst under microwave irradiation
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Manish Srivastava Anamika Srivastava Ashu Goyal Aakanksha Mishra Preeti Tomer Jaya Dwivedi D. Kishore 《Journal of Physical Organic Chemistry》2017,30(2)
We report here in highly efficient one‐pot catalytic system which utilizes in situ generated sodium ferrate for the oxidation of aromatic and cyclic hydrocarbons in the presence of Au (III) and Pd (II) metal ions catalyst under ecofriendly green synthetic method. Results of these studies revealed that Au (III) catalytic system gave higher yield as compared with Pd (II) catalytic system because of the higher electrode potential of Au(III) than Pd(II). All compounds were characterized by infrared and NMR spectral analysis. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
79.
Anamika Gambhir Manju Gerard Shailesh K. Jain B. D. Malhotra 《Applied biochemistry and biotechnology》2001,96(1-3):313-319
The article describes the adsorption characteristics of DNA onto electrochemically generated polypyrrole-polyvinyl sulfonate
(PPY-PVS) films obtained as a function of pH. Adsorption on PPY doped with an anion proceeds by anion exchange, and since
DNA possesses a fixed negative charge owing to PO
4
−
, it favors a very strong binding displacing PVS with favorable energetic interactions. Characterization of adsorbed DNA onto
the PPY-PVS films was carried out by ultraviolet-visible, Fourier transform infrared spectroscopy, and cyclic voltammetric
studies. 相似文献
80.
An efficient, cost‐effective and simple protocol has been developed for the synthesis of Hantzsch 1,4‐dihydropyridines and their oxidation into pyridines using benzyltrimethylammonium fluoride hydrate as an excellent catalyst under solvent‐free condition. All of the products synthesized by this method are characterized by various spectroscopic methods (IR, 1H NMR, 13C NMR, and DEPT). 相似文献