Fluorescence intensities in both excitation wavelength ranges decayed exponentially with irradiation time consistent with firstorder kinetics
There was little change in wavelength for primary oil peaks. However, in the CDOM, wavelength range peaks typically shifted to longer excitation and shorter emission wavelengths, moving into the protein peak region of the CDOM EEM spectrum. This is consistent with a decrease in the complexity of the structure of the organic material. Half-lives for photodegradation ranged from 06 to 7 days for the oil wavelength range and 04 to 28 days for the CDOM wavelength range. Higher density oils typically had higher degradation rate constants. Peak locations and peak behaviour are consistent with the primary fluorophore in the oil products being PAH-related.
Evaluation of L929 fibroblast attachment and proliferation on Arg-Gly-Asp-Ser (RGDS)-immobilized chitosan in serum-containing/serum-free cultures.In this study, chitosan membranes prepared by the solvent casting method were modified with the Arg-Gly-Asp-Ser (RGDS) sequence of fibronectin using the photochemical immobilization technique. The results obtained from attenuated total reflection-Fourier transform infrared spectra and X-ray photoelectron spectroscopy studies confirmed the successful immobilization of RGDS on chitosan membranes. The immobilized peptide concentration was determined by ninhydrin performed with L929 mouse fibroblasts to investigate the effect of biomodification on fibroblast cell behaviour in serum-free and 10% serum-containing media. The results obtained from cell culture studies pointed out the specific interactions between biosignal RGDS molecules and fibroblast cells. A triggered cell attachment and proliferation were observed on RGDS-modified chitosan membranes that were more distinguishable in serum-free medium. In addition, the photochemical immobilization technique was realized in the presence of a photomask that was used to immobilize the RGDS molecules in a defined micropattern.
L929 mouse fibroblasts attached on the RGDS-micropatterned areas indicating integrin-mediated interactions.Heat treatment for reduction of surface roughness on holographic gratings.Controlled postdevelopment heat treatment of the photoresist polymer used in the preparation of holographic gratings has been shown to enhance the diffraction efficiency of gratings and reduce the scattering losses. We prove this effect by analyzing the resonant reflection spectra of a waveguide grating and observing the reduction in the arc-shaped light scattering associated with the excitation Copying computer-generated-holographic interconnects by the use of partially Fimia A, Fuentes R, Pascual I, Beléndez A, Egozcue JJ, Navarro MT.Dichromated gelatin, bleached photographic emulsion, photoresist, and silver halide-sensitived gelatin are studied as holographic recording materials for holographic optical interconnects. We make the analysis by using a copying process with a computer-generated interconnect, which produces 64 diffracted beams on axis, as a master. The experimental results obtained confirm that it is possible to obtain copies in which we improve the performance of the master.
Structural concept for fluorinated Y-enynes with solvatochromic properties.An approach to the development of fluorescent probes to follow polymerizations in situ using fluorinated cross-conjugated enediynes (Y-enynes) is reported. Different substitution patterns in the Y-enynes result in distinct solvatochromic behavior. beta,beta-Bis(phenylethynyl)pentafluorostyrene 7, which bears no donor substituents and only fluorine at the styrene moiety, shows no beta,beta-bis(3,4,5-trimethoxyphenylethynyl)pentafluorostyrene 8 and beta,beta-bis(4-butyl-2,3,5,6-tetrafluorophenylethynyl)-3,4,5-trimethoxystyrene 9 exhibit solvatochromism upon change of solvent polarity. Y-enyne 8 showed the largest solvatochromic shift (94 nm bathochromic shift) upon changing solvent from cyclohexane to acetonitrile. A smaller solvatochromic response (44 nm bathochromic shift) was observed for 9. Lippert-Mataga treatment of 8 and 9 yields slopes of -10,800 and -6,400 cm(-1), respectively.
This corresponds to a change in dipole moment of 9 and 6 D, respectively. The solvatochromic behavior in 8 and 9 supports the formation of an intramolecular charge transfer (ICT) state. The low fluorescence quantum yields are caused by competitive double bond rotation. 6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid in Medicinal Chemistry of 9 decreases in methyltetrahydrofuran from 2 ns at 77 K to 01 ns at 200 K. Efficient single bond rotation in 9 was frozen at -50 degrees C in a configuration in which the trimethoxyphenyl ring is perpendicular to the fluorinated rings. 7-9 are photostable compounds. The X-ray structure of 7 shows it is not planar and that its conjugation is distorted.
Y-enyne 7 stacks in the solid state showing coulombic, actetylene-arene, and fluorine-pi interactions.Exploring the influence of graphene on antiaromaticity of pentalene.Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala, 695551, India. Theoretical investigations on the influence of graphene fragments on the antiaromaticity of pentalene are conducted by employing multiple aromaticity descriptors based on magnetic, geometric and electronic criteria.
