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71.
C. Aragón F. Peñalba J.A. Aguilera 《Applied Physics A: Materials Science & Processing》2004,79(4-6):1145-1148
Spatial distributions of temperature and relative number densities of Fe neutral atoms and ions in a laser-induced plasma have been measured by time- and space-resolved emission spectroscopy. The deconvolution of the intensity spectra has been carried out to obtain the local emissivity of neutral atom and ion lines as a function of the axial (z) and radial (r) coordinates. The plasma was generated with a Fe-Ni-Al alloy in air at atmospheric pressure using a Nd:YAG laser. The distributions present a dark region with negligible neutral atom and ion emissivities and densities, situated close to the sample surface at axial distances z1 mm. In the emitting region, the temperature has its maximum at the plasma axis (16000 K) and shows a monotonous decrease towards the border (6000 K). The neutral atoms and ions occupy regions corresponding to a great extent to different radial positions. At an axial distance z=1.8 mm, at which the maximum emissivities are produced, the maximum of the ion density is at r0.6 mm, whereas the neutral atom density maximum is at r1.3 mm. PACS 52.70.kz; 52.50.Jm; 52.38.Mf 相似文献
72.
María Victoria de Gálvez José Aguilera Jean‐Luc Bernabó Cristina Sánchez‐Roldán Enrique Herrera‐Ceballos 《Photochemistry and photobiology》2015,91(4):966-970
The rising incidence of skin cancers attributable to excessive sun exposure has become a major health concern worldwide. While numerous studies have analyzed the sun protective effect of sunscreens, clothing and antioxidants, none to date have measured the photoprotective effect of hair, despite clinical evidence that individuals with balding or thinning hair are at greater risk of skin lesions that can progress to cancer, hence the recommendation to use hats or umbrellas. We analyzed the level of protection offered by hair according to hair density, thickness and color using the spectral transmittance and corrected for relative erythema effectiveness. Our results show that hair provides a barrier against both UVB and UVA radiation which is significantly increased with respect to the hair density, thickness and the presence of melanins. This is the first study to quantify sun protection factor offered by hair, namely hair ultraviolet protection factor (HUPF). We believe that hair should be recognized as an important natural sun barrier in the prevention of UV‐induced skin cancers. 相似文献
73.
New potential biomarkers for mesterolone misuse in human urine by liquid chromatography quadrupole time‐of‐flight mass spectrometry
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Jianghai Lu María Fernández‐Álvarez Sheng Yang Genye He Youxuan Xu Rodigo Aguilera 《Journal of mass spectrometry : JMS》2015,50(1):153-159
In this paper, mesterolone metabolic profiles were investigated carefully. Mesterolone was administered to one healthy male volunteer. Urinary extracts were analyzed by liquid chromatography quadruple time‐of‐flight mass spectrometry (LC‐QTOFMS) for the first time. Liquid–liquid extraction was applied to processing urine samples, and dilute‐shoot analyses of intact metabolites were also presented. In LC‐QTOFMS analysis, chromatographic peaks for potential metabolites were hunt down by using the theoretical [M–H]? as target ions in full scan experiment, and their actual deprotonated ions were analyzed in targeted MS/MS mode. Ten metabolites including seven new sulfate and three glucuronide conjugates were found for mesterolone. Because of no useful fragment ion for structural elucidation, gas chromatography–mass spectrometry instrumentation was employed to obtain structural details of the trimethylsilylated phase I metabolite released after solvolysis. Thus, their potential structures were proposed particularly by a combined MS approach. All the metabolites were also evaluated in terms of how long they could be detected, and S1 (1α‐methyl‐5α‐androst‐3‐one‐17β‐sulfate) together with S2 (1α‐methyl‐5α‐androst‐17‐one‐3β‐sulfate) was detected up to 9 days after oral administration, which could be the new potential biomarkers for mesterolone misuse. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
74.
E.M. Monge C. Aragón J.A. Aguilera 《Applied Physics A: Materials Science & Processing》1999,69(7):S691-S694
Temperature and electron-density profiles in a laser-produced plasma have been measured at various distances from the sample surface and different delay times from the laser pulse. The plasma is produced with a Nd:YAG laser focused on a low-alloy steel sample in air at atmospheric pressure. The determination of the parameters is made starting from the distinct emission spectra emitted by the plasma along a direction parallel to the sample surface and measured simultaneously by a CCD detector. The experimental relative error is 1.5% for temperatures and 4.5% for electron densities. A small spatial variation of the plasma temperature ((T K) is obtained except for the outer regions, were the intensity is weak. A higher spatial variation is obtained for the electron density, especially at initial times ((Ne17 cm-3 at t=3 7s). 相似文献
75.
The functional principal components analysis (PCA) involves new considerations on the mechanism of measuring distances (the norm). Some properties arising in functional framework (e.g., smoothing) could be taken into account through an inner product in the data space. But this proposed inner product could make, for example, interpretational or (and) computational abilities worse. The results obtained in this paper establish equivalences between the PCA with the proposed inner product and certain PCA with a given well-suited inner product. These results have been proved in the theoretical framework given by Hilbert valued random variables, in which multivariate and functional PCAs appear jointly as particular cases. 相似文献
76.
Praveen K. Roayapalley Jonathan R. Dimmock Lisett Contreras Karol S. Balderrama Renato J. Aguilera Hiroshi Sakagami Shigeru Amano Rajendra K. Sharma Umashankar Das 《Molecules (Basel, Switzerland)》2021,26(23)
A novel series of 1-[3-{3,5-bis(benzylidene)-4-oxo-1-piperidino}-3-oxopropyl]-4-piperidone oximes 3a–h and related quaternary ammonium salts 4a–h were prepared as candidate antineoplastic agents. Evaluation against neoplastic Ca9-22, HSC-2 and HSC-4 cells revealed the compounds in series 3 and 4 to be potent cytotoxins with submicromolar CC50 values in virtually all cases. In contrast, the compounds were less cytocidal towards HGF, HPLF and HPC non-malignant cells revealing their tumour-selective toxicity. Quantitative structure–activity relationships revealed that, in general, both cytotoxic potency and selectivity index figures increased as the magnitude of the Hammett sigma values rose. In addition, 3a–h are cytotoxic towards a number of leukemic and colon cancer cells. 4b,c lowered the mitochondrial membrane potential in CEM cells, and 4d induced transient G2/M accumulation in Ca9-22 cells. Five compounds, namely 3c,d and 4c–e, were identified as lead molecules that have drug-like properties. 相似文献
77.
Guido S. Canessa Carlos Aguilera Jos Luis Serrano Luis Oriol 《Journal of polymer science. Part A, Polymer chemistry》1996,34(8):1465-1473
A series of azo monomers for polycondensation have been synthesized and characterized. These monomers, which contain electron-donor or acceptor substituents, have been condensed with aliphatic monomers to obtain two different series of aliphatic main-chain polyesters with pendant mesogenic groups. The polymers display nematic or smectic phases depending on the structural modifications of pendant mesogenic groups and the length of the flexible main-chain. In addition to these series, two polyesters with a high concentration of side pro-mesogenic groups have been synthesized. © 1996 John Wiley & Sons, Inc. 相似文献
78.
Montesino Luis Enrique Llanes Corrales Yuri Aguilera Páez Ahmed Díaz Mazola Yuniel Tejeda Catasús Judith Domínguez Portela Jorge Borroto 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(9):3359-3364
Journal of Radioanalytical and Nuclear Chemistry - Pretreated silica sand labeling using varying concentrations of tin(II) fluoride and chloride as reducing agents and different times labeling was... 相似文献
79.
Trinh T. Do Vicky J. Tang Joseph A. Aguilera Jamie R. Milligan 《Radiation Physics and Chemistry》2010,79(11):1144-1148
In DNA, guanine bases are the sites from which electrons are most easily removed. As a result of hole migration to this stable location on guanine, guanyl radicals are major intermediates in DNA damage produced by the direct effect of ionizing radiation (ionization of the DNA itself and not through the intermediacy of water radicals). We have modeled this process by employing gamma irradiation in the presence of thiocyanate ions, a method which also produces single electron oxidized guanyl radicals in plasmid DNA in aqueous solution. The stable products formed in DNA from these radicals are detected as strand breaks after incubation with the FPG protein. When a phenolic compound is present in the solution during gamma irradiation, the formation of guanyl radical species is decreased by electron donation from the phenol to the guanyl radical. We have quantified the rate of this reaction for four different phenolic compounds bearing carboxylate substituents as proton acceptors. A comparison of the rates of these reactions with the redox strengths of the phenolic compounds reveals that salicylate reacts ca. 10-fold faster than its structural analogs. This observation is consistent with a reaction mechanism involving a proton coupled electron transfer, because intra-molecular transfer of a proton from the phenolic hydroxyl group to the carboxylate group is possible only in salicylate, and is favored by the strong 6-membered ring intra-molecular hydrogen bond in this compound. 相似文献
80.
R. García-Domenech J. Aguilera A. El Moncef S. Pocovi Jorge Gálvez 《Molecular diversity》2010,14(2):321-329
A topological-mathematical model based on multilinear regression analysis has been built to search new terpenoid actives as
mosquito repellents. The structural depiction was performed using topological indices, and a four-variable model for the prediction
of corrected repellent ratio (r
2 = 0.9672, Q
2 = 0.9435) was selected. The model was checked by cross-validation, internal validation, and randomization test. The results
confirm its capability to predict the property analyzed. After carrying out a virtual screening upon such a model, new structures
with potential repellent activity against mosquitoes are proposed. 相似文献