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21.
Photodithazine (PDZ) is an N-methyl-D-glucosamine derivative of chlorine e6 that is water soluble and has an intense absorption in the range of 650?C680 nm. PDZ photobleaching and photoproduct formation were induced by illumination with laser at two wavelengths: 514 nm (ion argon laser) as well as in 630 nm (dye laser). The time constants of PDZ photobleaching were: 18 min for 630 nm irradiation and 50 min for 514 nm irradiation, suggesting that degradation after irradiation with red light is faster than with green light. Photoproducts formation was evidenced by the appearance of a new absorption band at 668 nm with slight broaden of the Soret band, suggesting that there was no break of the macrocycle. The cytotoxicity of the photodegradated PDZ was investigated and showed to be lower in the dark and higher than non irradiated PDZ. These results may have important clinical implications for PDT such as the possibility to use the previously irradiated PDZ just before clinical application in order to get increased efficiency. 相似文献
22.
J. K. Brooks Kazuyuki Saitô JD Maitland Wright 《Rendiconti del Circolo Matematico di Palermo》2003,52(1):5-14
LetA be aC*-algebra with second dualA″. Let (φ
n)(n=1,...) be a sequence in the dual ofA such that limφ
n(a) exists for eacha εA. In general, this does not imply that limφ
n(x) exists for eachx εA″. But if limφ
n(p) exists whenever p is the range projection of a positive self-adjoint element of the unit ball ofA, then it is shown that limφ
n(x) does exist for eachx inA″. This is a non-commutative generalisation of a celebrated theorem of Dieudonné. A new proof of Dieudonné’s theorem, for
positive measures, is given here. The proof of the main result makes use of Dieudonné’s original theorem. 相似文献
23.
V.S. Bagnato L.A.O. Nunes S.C. Zilio H.J. Scheel J.C. Castro 《Solid State Communications》1984,49(1):27-30
Infrared 7FO → 7FJ electronic transitions are reported for Eu+3 in GdAlO3. The low symmetry of the crystalline field allows the observation, for the first time, of transitions with J = 3, 4, 5 and 6. The spectra are explained by means of a crystal-field model where a Cs term is added as a perturbation to the cubic field in order to take into account the lattice distortion. This model predicts energy levels which are in good agreement with the experimental data. 相似文献
24.
As it is known [1] an intense laser field can induce atom-atom interaction according to a dipole-dipole R
–3 law. Such an interaction depends on the angle between light polarization and interatomic vector-position R. This angular dependence may produce an anisotropy in the spatial density distribution of the confined sample of cold atoms. We develop the main relations and apply them to the case of an atomic cloud of cold trapped neutral atoms with the density higher than or of the order of –3, where is the wavelength of light. The results presented here show the effect of such an interaction in a density regime of high experimental interest. 相似文献
25.
26.
Dutra-Correa M. Nicolodelli G. Rodrigues J. R. Kurachi C. Bagnato V. S. 《Laser Physics》2011,21(5):965-971
This study evaluated the process of ablation produced by a Ti:Sapphire femtosecond laser under different average powers taking
place at the enamel/dentin interface. Based on the geometry of ablated microcavities the effective intensity for ablation
was obtained. This study shows the validity for the local effective intensity analysis and allows a quantification of the
variation in the ablation geometry taking place at the interface of two naturally different materials. It shows that the variation
of the diameter of the ablated region as a function of the cavity depth comes essentially from a mechanism of effective intensity
attenuation, as a result of a series of complex effects. Additionally, our data are sufficient to predict that a discontinuity
on the ablation profile will occur on the interface between two biological media: enamel-dentin, showing a suddenly jump on
the ablated cavity dimensions. 相似文献
27.
A. G. de Sousa A. B. F. da Silva V. S. Bagnato 《Journal of mathematical chemistry》2010,48(3):687-696
In this paper we consider the case of a Bose gas in low dimension in order to illustrate the applicability of a method that
allows us to construct analytical relations, valid for a broad range of coupling parameters, for a function which asymptotic
expansions are known. The method is well suitable to investigate the problem of stability of a collection of Bose particles
trapped in one- dimensional configuration for the case where the scattering length presents a negative value. The eigenvalues
for this interacting quantum one-dimensional many particle system become negative when the interactions overcome the trapping
energy and, in this case, the system becomes unstable. Here we calculate the critical coupling parameter and apply for the
case of Lithium atoms obtaining the critical number of particles for the limit of stability. 相似文献
28.
Johan Sebastián Díaz Tovar Dr. Giulia Kassab Dr. Natalia Mayumi Inada Prof. Dr. Vanderlei Salvador Bagnato Prof. Dr. Cristina Kurachi 《Chemphyschem》2023,24(18):e202300381
Indocyanine green is an attractive molecule for photodynamic therapy due to its near infrared absorption, resulting in a higher tissue penetration. However, its quantum yields of the triplet and singlet state have been reported to be low and then, reactive oxygen species are unlikely to be formed. Aiming to understand the ICG role in photodynamic response, its photobleaching behavior in solution has been studied under distinct conditions of CW laser irradiation at 780 and 808 nm, oxygen saturations and solvents. Sensitizer bleaching and photoproduct formation were measured by absorption spectroscopy and analyzed using the PDT bleaching macroscopic model to extract physical parameters. ICG photobleaching occurs even at lower oxygen concentrations, indicating that the molecule presents more than one way of degradation. Photoproducts were produced even in solution of less than 4 % oxygen saturation for both solvents and excitation wavelengths. Also, the amplitude of absorption related to J-dimers was increased during irradiation, but only in 50 % PBS solution. The formation of photoproducts was enhanced in the presence of J-type dimers under low oxygen concentration, and the quantum yields of triplet and singlet states were one order of magnitude and two times higher, respectively, when compared to ICG in distilled H2O. 相似文献
29.
30.
E. G. Saade M. C. Bandeca A. N. S. Rastelli V. S. Bagnato S. T. Porto-Neto 《Laser Physics》2009,19(6):1276-1281
The aim of this study was to evaluate the hardness of a dental composite resin submitted to temperature changes before photo-activation with two light-curing unite (LCUs). Five samples (4 mm in diameter and 2 mm in thickness) for each group were made with pre-cure temperatures of 37, 54, and 60°C. The samples were photo-activated with a conventional quartz-tungsten-halogen (QTH) and blue LED LCUs during 40 s. The hardness Vickers test (VHN) was performed on the top and bottom surfaces of the samples. According to the interaction between light-curing unit and different pre-heating temperatures of composite resin, only the light-curing unit provided influences on the mean values of initial Vickers hardness. The light-curing unit based on blue LED showed hardness mean values more homogeneous between the top and bottom surfaces. The hardness mean values were not statistically significant difference for the pre-cure temperature used. According to these results, the pre-heating of the composite resin provide no influence on Vickers hardness mean values, however the blue LED showed a cure more homogeneous than QTH LCU. 相似文献