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Phenyl-pyridine compounds present a high interest for Photodynamic Therapy due to their important... more Phenyl-pyridine compounds present a high interest for Photodynamic Therapy due to their important anti-inflammatory and anti-tumor properties. In this study, two phenyl-pyridine compounds were investigated BG204 (3-amino, 9-thio [2-N-Ndiethylaminoethyl] acridine) and BG 1120 (4,5 bis [thio(2-N-N-diethylaminoethyl)], 9methyl 1,8-diazantracene), because they present modification during UV irradiation. In order to elucidate these modifications FTIR spectroscopy was used. BG204 and BG1120 were UV irradiated using a Xe lamp, with a power density of 11mW/cm 2 , for 1 hour, and 3 hours, respectively. The FTIR spectra, in the range of 4000 cm -1 -400 cm -1 , were performed by a Nicolet Magna IR 550 spectrometer. The results of the analyzed samples showed that these molecules are photo-reactive, and their therapeutic effects can be improved by UV irradiation.
Journal of Crystal Growth, 2008
Angle-resolved X-ray photoelectron spectroscopy (ARXPS) analysis has been performed on GaAs (1 0 ... more Angle-resolved X-ray photoelectron spectroscopy (ARXPS) analysis has been performed on GaAs (1 0 0) surfaces in different conditions as naturally oxidized, Ar + ion sputtering (E ¼ 1-5 keV) and chemical etching in H 2 SO 4 /H 2 O 2 /H 2 O (3:1:1). The most sensitive angle to the surface compositional changes was the take-off angle (TOA): 251. Native oxide phases on GaAs consist of a mixture of Ga 2 O 3 , As 2 O 3 and As 2 O 5 . Ar + ion sputtering procedure modifies the surface composition, in the altered layer where the concentration ratio C Ga /C As tends to 1.5-1.6. Wet chemical etching removes the oxide layer and the As-rich region from the surface. In the experiment combining chemical etching with Ar + ion sputtering for cleaning purpose, the native oxides are removed from the surface and C Ga /C As tends to stoichiometry. The experiment on native oxide reconstruction after storage in high-vacuum conditions (p$10 À8 Torr) provides evidence of the high reactivity of GaAs (1 0 0) surfaces. We have observed the presence of an As oxide (BE ¼ 43 eV) within a concentration range of 2-3%. r
Phenyl-pyridine compounds present a high interest for Photodynamic Therapy due to their important... more Phenyl-pyridine compounds present a high interest for Photodynamic Therapy due to their important anti-inflammatory and anti-tumor properties. In this study, two phenyl-pyridine compounds were investigated BG204 (3-amino, 9-thio [2-N-Ndiethylaminoethyl] acridine) and BG 1120 (4,5 bis [thio(2-N-N-diethylaminoethyl)], 9methyl 1,8-diazantracene), because they present modification during UV irradiation. In order to elucidate these modifications FTIR spectroscopy was used. BG204 and BG1120 were UV irradiated using a Xe lamp, with a power density of 11mW/cm 2 , for 1 hour, and 3 hours, respectively. The FTIR spectra, in the range of 4000 cm -1 -400 cm -1 , were performed by a Nicolet Magna IR 550 spectrometer. The results of the analyzed samples showed that these molecules are photo-reactive, and their therapeutic effects can be improved by UV irradiation.
Journal of Crystal Growth, 2008
Angle-resolved X-ray photoelectron spectroscopy (ARXPS) analysis has been performed on GaAs (1 0 ... more Angle-resolved X-ray photoelectron spectroscopy (ARXPS) analysis has been performed on GaAs (1 0 0) surfaces in different conditions as naturally oxidized, Ar + ion sputtering (E ¼ 1-5 keV) and chemical etching in H 2 SO 4 /H 2 O 2 /H 2 O (3:1:1). The most sensitive angle to the surface compositional changes was the take-off angle (TOA): 251. Native oxide phases on GaAs consist of a mixture of Ga 2 O 3 , As 2 O 3 and As 2 O 5 . Ar + ion sputtering procedure modifies the surface composition, in the altered layer where the concentration ratio C Ga /C As tends to 1.5-1.6. Wet chemical etching removes the oxide layer and the As-rich region from the surface. In the experiment combining chemical etching with Ar + ion sputtering for cleaning purpose, the native oxides are removed from the surface and C Ga /C As tends to stoichiometry. The experiment on native oxide reconstruction after storage in high-vacuum conditions (p$10 À8 Torr) provides evidence of the high reactivity of GaAs (1 0 0) surfaces. We have observed the presence of an As oxide (BE ¼ 43 eV) within a concentration range of 2-3%. r