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1.
Anushree Das Emily A. Lao Anna D. Gudmundsdottir 《Photochemistry and photobiology》2016,92(3):388-398
Photolysis of ester 1 in argon‐saturated methanol and acetonitrile does not produce any product, whereas irradiation of 1 in oxygen‐saturated methanol yields peroxide 2 . Laser flash photolysis studies demonstrate that 1 undergoes intramolecular H atom abstraction to form biradical 3 (λ max ~ 340 nm), which intersystem crosses to form photoenols Z ‐ 4 and E ‐ 4 (λ max ~ 380 nm). Photoenols 4 decay by regenerating ester 1 . With the aid of density functional theory calculations, it was concluded the photoenol E ‐ 4 does not undergo spontaneous lactonization or electrocyclic ring closure because the transition state barriers for these reactions are too large to compete with reketonization of E ‐ 4 to form 1 . 相似文献
2.
Effect of high‐energy light‐ion irradiation on SI‐GaAs and GaAs:Cr as observed by Raman spectroscopy
Shramana Mishra D. Kabiraj Anushree Roy Subhasis Ghosh 《Journal of Raman spectroscopy : JRS》2012,43(2):344-350
The structural evolutions of high‐energy (50 MeV) lithium ion (Li3+) irradiated undoped semi‐insulating GaAs (SI‐GaAs) and chromium‐doped SI‐GaAs (GaAs:Cr) were investigated by Raman measurements. It is shown that high‐energy Li3+ irradiation causes amorphization beyond a fluence of 3 × 1013 ions/cm2 in undoped SI‐GaAs. Interestingly, the same fluence of ions does not seem to affect the crystallinity in GaAs:Cr appreciably. The effect of ion irradiation on the change in lattice ordering and anharmonicity of the phonon modes of undoped SI‐GaAs and GaAs:Cr is also compared. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Enzyme from Daucus carota root catalyzed Henry reaction of substituted benzaldehydes and nitromethane in phosphate buffer of pH 7 at 28?°C to afford β-nitroalcohols in excellent yields (up to 94%). 相似文献
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Dr. Sourav Sarkar Anushree Shil Suman Maity Dr. Yun Lim Jung Dr. Mingchong Dai Prof. Atanu Acharya Prof. Kyo Han Ahn 《Angewandte Chemie (International ed. in English)》2023,62(43):e202311168
Aryl alcohol-type or phenolic fluorophores offer diverse opportunities for developing bioimaging agents and fluorescence probes. Due to the inherently acidic hydroxyl functionality, phenolic fluorophores provide pH-dependent emission signals. Therefore, except for developing pH probes, the pH-dependent nature of phenolic fluorophores should be considered in bioimaging applications but has been neglected. Here we show that a simple structural remedy converts conventional phenolic fluorophores into pH-resistant derivatives, which also offer “medium-resistant” emission properties. The structural modification involves a single-step introduction of a hydrogen-bonding acceptor such as morpholine nearby the phenolic hydroxyl group, which also leads to emission bathochromic shift, increased Stokes shift, enhanced photo-stability and stronger emission for several dyes. The strategy greatly expands the current fluorophores’ repertoire for reliable bioimaging applications, as demonstrated here with ratiometric imaging of cells and tissues. 相似文献
5.
Venkatraman Senthil Kumar Choudhary Rajan Genasan Krishnamurithy Murali Malliga Raman Raghavendran Hanumantha Rao Balaji Kamarul Tunku Suresh Anushree Abraham Jayanthi Venkateswaran Seshasailam Livingston Abel Swamiappan Sasikumar 《Journal of Sol-Gel Science and Technology》2021,100(3):506-516
Journal of Sol-Gel Science and Technology - Biocompatibility and bacterial infections are the primary concerns associated with the current bone graft substitutes. The application of... 相似文献
6.
Harshita Sharma Anushree Saha Arun Kumar Mishra Manish Kumar Rai Manas Kanti Deb 《印度化学会志》2022,99(7):100483
A new sensitive spectrophotometric method for the determination of glyphosate herbicide in environmental and agricultural samples is developed. The reaction is based on diazotization followed by coupling of glyphosate with p-dimethyl amino benzaldehyde. The resulted complex absorption spectra was observed at λmax = 420 nm. The effects of other metal ions and pesticides were also tested for selective determination of glyphosate. The analytical parameters were optimized and have been successfully applied for determination of glyphosate in various environmental samples such as soil, water and vegetables. This method has a lower limit detection of 6 μg of glyphosate. Beer's law is obeyed over the concentration range of 6.0 μg–24.0 μg glyphosate in 25 mL of the final solution at 420 nm. The standard deviation and relative standard deviation calculated are 0.0055 and 1.023, respectively. The molar absorptivity of the colored system is 1.91 × 1010 L mol?1cm?1 and Sandell's sensitivity is found 0.408 × 10?5 μg cm?2. The proposed method is simple, sensitive, highly reproducible and time saving as compare to those complicated time consuming methods. 相似文献
7.
Shramana Mishra D. Kabiraj Anushree Roy Subhasis Ghosh 《Solid State Communications》2010,150(39-40):1892-1895
The second-order transverse acoustic mode and amorphous Raman modes, originating from a continuous random network and medium range ordering (MRO), in high energy light ion (HELI) irradiated GaAs are investigated. The change in the phonon density of states of the transverse acoustic mode phonon distinguishes the effect of HELI irradiation on highly resistive undoped and chromium-doped GaAs. The boson mode, originating from the MRO of the system, has been identified and a model based on phonon-fracton scattering has been used for the explanation of this “boson mode”. The spectral dimension, correlation length and the scaling factor, with which the elastic constant varies with length in MRO regions in GaAs, are estimated. 相似文献
8.
Inhibition of Candida albicans growth was shown by lemon grass oil (LGO) and lemon grass oil vapour (LGO vapour) at 288 μg/ml and 32.7 μg/ml concentration, respectively. The assessment of cell damage by LGO and LGO vapour was done through scanning electron microscope (SEM), transmission electron microscope (TEM) and atomic force microscope (AFM) observations. SEM analysis showed complete rupture of C. albicans cells treated with LGO vapour while in those treated with LGO in broth, only shrinkage was observed. TEM study showed the alterations in morphology upon treatment with LGO while complete degradation of the Candida cells was observed in case of LGO vapour. Further three dimensional morphological changes and roughness of the cells have also been evaluated with AFM after the treatment with LGO & LGO vapour. Roughness (root mean square value) was significantly higher in control C. albicans cells (211.97 nm) than LGO (143 nm) and LGO vapour (5.981 nm) treated cells. The results for the first time demonstrate relatively higher efficacy of LGO vapours for inhibition and cellular damage of C. albicans cells as compared to the LGO in liquid phase. This suggests the potential application of LGO vapour phase against infections caused by C. albicans. 相似文献
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10.
Susmita Bhattacharya Nidhi Vyas Animesh K. Ojha Swagata Dasgupta Anushree Roy 《Journal of Raman spectroscopy : JRS》2012,43(6):718-723
The interaction of l ‐tryptophan (Trp) with silver colloids was investigated at between pH values of 6.11 and 10.6 of the sol. The measurements of surface‐enhanced Raman bands of Trp in the colloidal solution indicate the evolution of interaction between the metal particles and the molecules with increasing pH values for the sol. The experimental observations were explained using the estimated atomic charge distribution in the zwitterionic and anionic forms of the residue, obtained by density functional theory calculations. The variation in the ratio of the spectral intensities of the Fermi resonance bands with the pH reflects the effect of the colloidal environment on Trp. The results obtained can be used as a marker for describing the nature of the interaction of silver colloids with the specific terminus of the residue, at varying pH environments. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献