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1.
Carré V Gaud O Sylvain I Bourdon O Spiro M Blais J Granet R Krausz P Guilloton M 《Journal of photochemistry and photobiology. B, Biology》1999,48(1):57-62
A series of neutral meso-arylglycosylporphyrins has been tested in order to evaluate their potency as antifungal agents against the yeast Saccharomyces cerevisiae. Photodynamic activity of these molecules results in intracellular damage as evidenced by the loss of clonogenicity and DNA fragmentation. The ability of these photosensitizers to permeate yeast cells is determined by microspectrofluorimetry and is correlated with their antifungal potency. Amphiphilic porphyrin derivatives are shown to exhibit the more pronounced photoactivity. 相似文献
2.
We investigate the property of polarization independent reflection using a 1D grating. It is shown to be possible, by choosing the correct parameters of the structure and angle of incidence to adjust the bandwidth of the reflection curves for both polarizations in such a way that these coincide. We expect that the found polarization-independent narrow band filter can be used as a component for WDM applications. 相似文献
3.
M. Granet A. Nonell G. Favre F. Chartier H. Isnard J. Moureau C. Caussignac B. Tran 《Spectrochimica Acta Part B: Atomic Spectroscopy》2008
In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N2O gas in the cell leads to an antagonistic behavior of Cs+ and Ba+ as the latter reacts with the gas to form BaO+ and BaOH+ products whereas Cs+ remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k = 2). This study confirms the strong potential of collision–reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations. 相似文献
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P. Granet M. Loret L. Mosca J. Saudraix J.C. Scheuer C. Dujardin J. Laurent J. Schlesinger R. Windmolders J.J. Dumoni S. Tavernier F. Verbeure H. Blumenfeld K. Dziunikowska I.V. Ajinenko P.V. Chliapnikov L.N. Guerdyukov B.A. Manyukov O.G. Tchikilev 《Physics letters. [Part B]》1976,62(3):350-352
Elastic scattering of 32.1 GeV/c K+ on protons has been measured in a bubble chamber experiment. Results are presented in the momentum transfer interval 0.06–1.40 GeV2 and compared with data at different energies. An effective Regge trajectory is calculated using K+p elastic data from 10 to 175 GeV/c. 相似文献
6.
H. Isnard M. Granet C. Caussignac E. Ducarme A. Nonell B. Tran F. Chartier 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009,64(11-12):1280-1286
In the nuclear domain, precise and accurate isotopic composition determination of elements in spent nuclear fuels is mandatory to validate neutron calculation codes and for nuclear waste disposal. The present study presents the results obtained on Cs isotope ratio by mass spectrometric measurements. Natural cesium is monoisotopic (133Cs) whereas cesium in spent fuels has 4 isotopes (133Cs, 134Cs, 135Cs, and 137Cs). As no standard reference material is available to evaluate the accuracy of Cs isotopic measurements, a comparison of cesium isotopic composition in spent nuclear fuels has been performed between Thermal Ionization Mass Spectrometry (TIMS) and a new method involving Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) measurements. For TIMS measurements, isotopic fractionation has been evaluated by studying the behavior of cesium isotope ratios (133Cs/137Cs and 135Cs/137Cs) during the analyses. For MC-ICPMS measurements, the mass bias effects have been corrected with an external mass bias correction using elements (Eu and Sb) close to cesium masses. The results obtained by the two techniques show good agreement: relative difference on 133Cs/137Cs and 135Cs/137Cs ratios for two nuclear samples, analyzed after chemical separation, ranges from 0.2% to 0.5% depending on the choice of reference value for mass bias correction by MC-ICPMS. Finally the quantification of the 135Cs/238U ratio by the isotope dilution technique is presented in the case of a MOx (mixed oxide) spent fuel sample. Evaluation of the global uncertainties shows that this ratio could be defined at an uncertainty of 0.5% (k = 2). The intercomparison between two independent mass spectrometric techniques is fundamental for the evaluation of uncertainty when no isotopic standard is available. 相似文献
7.
Benoit Enaux Victor Granet Olivier Vermorel Corine Lacour Ludovic Thobois Vincent Dugué Thierry Poinsot 《Flow, Turbulence and Combustion》2011,86(2):153-177
This paper describes a compressible Large Eddy Simulation (LES) used to investigate cyclic variations for nonreacting flow
in an optical single cylinder engine setup. The simulated operating point is part of a large experimental database designed
to validate LES for cycle-to-cycle prediction, and constitutes a first step towards the realization of fired operating points.
The computational domain covers almost the whole experimental setup (intake and exhaust plenums, intake and exhaust ducts,
cylinder) to account for acoustic phenomena. The assessment of the computation is performed in two regions of the domain:
the intake and exhaust duct predictions are compared to the results of a Helmholtz solver and the experiment (pressure transducers
and Particle Image Velocimetry (PIV)) while the in-cylinder dynamics are compared to PIV measurements. The ability of the
developed methodology to capture the correct level of cycle-to-cycle variations is demonstrated considering in-cylinder pressure
and velocity fields predictions. Cycle-to-cycle variations in velocity are highlighted and localized using a proper orthogonal
decomposition analysis. 相似文献
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P. Granet L. Mosca J. Saudraix J.C. Scheuer D. Vilanova H. Blumenfeld V.P. Henri J. Kesteman J. Laurent R. Windmolders E. de Wolf S. Tavernier F. Verbeure I.V. Ajinenko P.V. Chliapnikov L.N. Gerdyukov P.A. Gorbunov A.M. Rybin 《Nuclear Physics B》1978,140(3):389-408
The inclusive production of resonances is systematically studied in K+p interactions at 32 GeV/c. Total production cross sections are given for three baryon resonances, five vector and three 2+ tensor mesons. We also compare the central and fragmentation components of the total production cross sections with quark model predictions. 相似文献
9.
Photodynamic treatment of promyelocytic K562 cells in the presence of a monoglucosylporphyrin or hematoporphyrin leads to a sequence of events recognized as hallmarks of apoptosis: a drop in mitochondrial potential, concurrent with a drop in ATP level and a decrease in cell respiration, translocation of phosphatidylserine of the plasma membrane, DNA fragmentation, appearance of apoptotic bodies and eventually loss of plasma membrane integrity. The chronology of these events is in accordance with sequential events induced by other known proapoptotic agents; in contrast to these agents that induce apoptosis in a restricted part of the cell population, we observed that the entire cell population (apart from a small percentage of cells that endured rapid necrosis during phototreatment) underwent apoptosis after irradiation in the presence of porphyrins. It appears that photodynamic treatment allows the bypass of early apoptotic signals in K562 cells that are otherwise renowned for their resistance to drug-induced apoptosis (A. McGahon, R. Bissonnette, M. Schmitt, K. M. Cotter, D. R. Green and T. G. Cotter, Blood 83, 1179-1187, 1994). Singlet oxygen is believed to be the proximate reactive species generated by porphyrin illumination. Because this molecule reacts with almost every cellular constituent, the way that singlet oxygen or its reactive oxygen species byproducts trigger apoptosis remains to be elucidated. 相似文献
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