scholarly journals Monitoring Light-induced Structural Changes of Channelrhodopsin-2 by UV-visible and Fourier Transform Infrared Spectroscopy

2008 ◽  
Vol 283 (50) ◽  
pp. 35033-35041 ◽  
Author(s):  
Eglof Ritter ◽  
Katja Stehfest ◽  
Andre Berndt ◽  
Peter Hegemann ◽  
Franz J. Bartl
Author(s):  
S. J. Pradeeba ◽  
K. Sampath

This research was carried out based on the significance of protecting the environment by preventing the contamination of water caused from effluents discharge from dyeing industries, effective nanocomposite were prepared to solve this problem. The poly(azomethine), ZnO, and poly(azomethine)/ZnO nanocomposites were prepared and characterized by Fourier transform-infrared spectroscopy, ultraviolet (UV)–visible spectroscopy, powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), scanning electron Microscope (SEM), and transmission electron microscopy (TEM) techniques. Methylene blue (MB), Malachite green (MG), and Bismarck brown (BB) were degraded from water using poly(azomethine) (PAZ), zinc oxide (ZnO), PAZ/ZnO (PNZ) nanocomposites as photocatalyst in the presence of natural sunlight. The degradation efficiency and reaction kinetics were calculated, and the outcome of the photocatalytic experiments proved that the PAZ/ZnO nanocomposites reveals excellent photocatalytic activity and effective for decolorization of dye containing waste water than PAZ and ZnO in the presence of natural sunlight. The maximum degradation efficiency 97%, 96%, and 95% was obtained for PNZ nanocomposites at optimum dosage of catalyst as 500 mg and 50 ppm of MB, MG, and BB dye concentration, respectively. The maximum degradation time was 5 h. After photocatalytic study, the samples were characterized by Fourier-transform infrared spectroscopy (FT-IR) and UV–visible spectroscopy.


1998 ◽  
Vol 52 (2) ◽  
pp. 222-225
Author(s):  
Mamoru Hashimoto ◽  
Hiro-O Hamaguchi

The surface (about 130 molecular layers) of an oriented thin crystal of decanoic acid was subjected to sudden melting by a laser-induced temperature jump (T-jump), and the process of subsequent crystal re-growth was monitored by millisecond time-resolved multichannel Fourier transform infrared spectroscopy. The gauche–trans structural change of the alkane part of the molecule has been probed by the CH stretch bands in the 2800–3000 cm−1 region. The change in the molecular orientation has been detected by the OH stretch band around 3065 cm−1. The recovery curves for the CH2 antisymmetric stretch and the OH stretch bands are markedly different from each other in the first 200 ms, suggesting that the gauche–trans structural changes precedes the crystal re-growth. After 500 ms, the recovery curves become identical. This result means that the rate of the gauche to the trans structural change is equal to the rate of the recovery of the molecular orientation. It is highly likely that a fast equilibrium is attained between the gauche and the trans conformations in the liquid phase after 500 ms from the sudden melting and that the crystal re-growth takes place solely via the all-trans structure in the liquid phase.


Author(s):  
A ANTONY LAWRENCE ◽  
J THOMAS JOSEPH PRAKASH

Objective: The present study was to synthesize nanoparticles using Manilkara hexandra stem bark extract its characterization and evaluating it by an antimicrobial and antioxidant assay. Methods: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) was done by mixing silver nitrate (1 mmol) and aqueous stem bark extract and it was analyzed by UV-Visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), Zeta potential, Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDAX), Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC). The antibacterial assay was done by a well diffusion method and also examined for antifungal assay was done by disk diffusion method and antioxidant potential Diphenyl-1-picryl hydrazyl (DPPH method) Results: Manilkara hexandra stem bark silver nanoparticles (MHSB-AgNPs) is characterized by various techniques such as UV-visible absorption spectrum ranges from 430 nm to 440 nm indicate silver nanoparticles. The Fourier Transform Infrared Spectroscopy consists of biomolecules acts as capping agent to form silver nanoparticles. Field Emission Scanning Electron Microscopy shows particle size ranges from 15 nm to 50 nm. Energy Dispersive Spectroscopy shows the presence of Silver. X-ray Diffraction corresponds to face-centered lattice planes (111), (200), (220) and (311). Dynamic Light Scattering show the range of 68 nm and Zeta potential show the negative value of-17 nm which has high stability. Silver nanoparticles is also examined by Thermogravimetry/Differential Thermal Analysis (TG/DTA) and Differential scanning calorimetry (DSC) this project the thermal stability of the nanoparticles. The aqueous stem bark is also examined by UV-visible absorption spectrum, Fourier Transform Infrared Spectroscopy (FTIR), and Gas Chromatography-Mass Spectrometry (GCMS). In GCMS 20 compounds were identified. Silver nanoparticles show high zone of inhibition in antimicrobial assays and act as a good antioxidant agent. Conclusion: It is eco-friendly, non-toxic, and it’s easy to synthesis and it shows good result in an antimicrobial and antioxidant assay can be applied in a pharmaceutical application.


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