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21.
Flávia R. O. Silva Camila T. Nabeshima Maria H. Bellini Nestor Schor Nilson D. Vieira Jr Lilia C. Courrol 《Journal of fluorescence》2013,23(1):131-135
This paper describes the elimination of porphyrins by feces. It was demonstrated that porphyrin accumulates substantially more in tumors than in normal tissues, and consequently more PPIX reaches the blood of patients and animals with tumors, and then, it needs to be eliminated. The fluorescence of feces revealed that there are large amounts of PPIX in the excreta of animals with cancer comparing with healthy animals. The autofluorescence of feces porphyrin extracted with acetone was analyzed using fluorescence spectroscopy of animals inoculated with DU145 cells into the prostate and healthy animals to monitor the PPIX concentration. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences were observed in autofluorescence intensities measured in the 575–725 nm spectral regions for the studied groups. The results showed a noninvasive, simple, rapid and sensitive method to detect cancer by feces analysis. 相似文献
22.
E.M. de Miguel-Sanz M. Tebaldi S. Granieri N. Bolognini L. Arizmendi 《Applied physics. B, Lasers and optics》2000,70(3):379-383
A photorefractive optical correlator stored and fixed in lithium niobate is presented. The device shows good correlation characteristics
together with very high output efficiency and insensitivity to optical erasure during read-out.
Received: 10 May 1999 / Revised version: 21 June 1999 / Published online: 16 September 1999 相似文献
23.
24.
Nestor Guillen 《Calculus of Variations and Partial Differential Equations》2009,36(4):533-546
We prove under general assumptions that solutions of the thin obstacle or Signorini problem in any space dimension achieve
the optimal regularity C
1,1/2. This improves the known optimal regularity results by allowing the thin obstacle to be defined in an arbitrary C
1,β
hypersurface, β > 1/2, additionally, our proof covers any linear elliptic operator in divergence form with smooth coefficients. The main
ingredients of the proof are a version of Almgren’s monotonicity formula and the optimal regularity of global solutions. 相似文献
25.
Claudio Darıo Archubi Nestor R. Arista 《The European Physical Journal B - Condensed Matter and Complex Systems》2017,90(1):18
A comparative study of the energy loss, mean free path and straggling of protons, positrons and electrons in an electron gas is performed using three dielectric models which represent the case of metals (Lindhard model for a free electron gas) and the cases of semiconductors and insulators (Levine and Louie model and Brandt and Reinheimer model for systems with a band gap). The properties of individual and collective contributions according to each model and for each of the particles are analyzed. In particular, the effects produced by the band gap of the material and by the properties of the incident particle are analyzed in detail. Significant differences related to the mass and to the indistinguishability (in the case of electrons) are described. Analytical expressions for the high-energy limit are derived in a simple way using the plasmon-pole approximation. 相似文献
26.
Ebenezer O. Oniya George S. Polymeris Nestor C. Tsirliganis George Kitis 《Radiation measurements》2012,47(9):864-869
Pre-dose sensitization of various components of LM-OSL signal of a Nigerian annealed quartz sample has been investigated along side with that of 110 °C TL peak in this work. Successive cycles of irradiations and TL/OSL readings using different heating rates were employed to attain pre-dose sensitization. The results showed that the pre-dose sensitization factor of 110 °C TL peak depends strongly on the heating rate of thermal activation. The pre-dose sensitization of 110 °C TL and all components of RT LM-OSL yield HR dependence on the sensitization after TA. This dependence was ascribed to the different heating time associated with each HR. Sensitization of LM-OSL measured at 125 °C generally does not show dependence on HR of TA. This was with the exception of components C1 and C3. Increasing sensitization pattern with increasing HR suggests a correlation between the TL glow-peak at 110 °C, the component C4 of RT LM-OSL and the component C3 of the LM-OSL signal at 125 °C. Extension of the present investigation to diverse quartz kinds from different origins was suggested in order to study the prevalence of the pre-dose sensitization on component C4 of RT LM-OSL. Finally fast heating is suggested for lower sensitization of fast component while applying OSL dating protocols. 相似文献
27.
Jorge A. Gómez Edgar RuedaÁngel Salazar Myriam TebaldiNestor Bolognini Alberto Lencina 《Optics and Lasers in Engineering》2012,50(3):359-365
In this work, we show that it is possible to change the properties of an optical vortex formed in a speckle pattern by the control of an external electric field applied to a sillenite-type photorefractive material in a non-holographic configuration. To show it, a scheme that allows the recovering of both, the polarization state and the phase distribution of an optical field was implemented. Changes in the polarization state of the light in the neighborhood of the vortex were observed with the application of an external electric field. Likewise, changes in the phase structure around the vortex and displacements of the vortices themselves were measured. These displacements have a fairly linear dependence on the applied field to the photorefractive crystal. Experimental results are qualitatively explained with the theoretical treatment of non-holographic recording in photorefractive crystals. 相似文献
28.
A. Alberti L. Bolognini D. Macciantelli M. Caratelli 《Research on Chemical Intermediates》2000,26(3):253-267
The alkoxy and peroxy radicals formed in the degradation of hydroperoxides brought about by transition metal ions in acidic
media can convert substrates with suitably low oxidation potentials, such as N,N-diethyl-para-phenylendiamine, to the corresponding radical cations. The possibility that these reactions are used in the evaluation of
oxidative stress in human beings is discussed. 相似文献
29.
30.
H. H. Sutherland Z. Ali Adib G. W. Gray D. Lacey G. Nestor K. J. Toyne 《Liquid crystals》1988,3(10):1293-1300
A series of terminally cyano substituted side chain polysiloxanes have been characterized using optical microscopy, D.S.C., and X-ray diffraction. Values for the lamellar spacings, d, of the interdigitated smectic A phases were obtained, and the variations in d with temperature and length of the flexible aliphatic spacer are discussed. The spacing for m = 4, 5, and 6 increased regularly with m whereas the short m = 3 spacer gave an anomalously high value. 相似文献