We demonstrate the generation of high-order harmonics of laser pulses in palladium and cadmium plasmas. We adjusted the wavelength of driving pulses to investigate the resonance enhancement in ...different ranges of extreme ultraviolet region. The summation of incommensurate waves during the two-color pump of Pd and Cd plasmas allowed the generation of a broader range of harmonics. The theoretical aspects of the two-color pump of the laser-induced plasma are discussed.
ZnO nanorods grown by gaseous-disperse synthesis are confirmed by XRD analysis to have the wurtzite crystal structure. The obtained crystallites, as found from SEM studies, are 57 ± 9 nm in diameter ...and 470 ± 30 nm long on the average. Two emission bands of photoluminescence from ZnO nanorods observed at room temperature are centered at 376 and 520 nm. A biosensitive layer is prepared by immobilization of anti-Salmonella antibodies from liquid solutions on the ZnO surface. Immobilization of the biosensitive layer onto ZnO nanorods is found to increase the intensity of PL. After further reaction with Salmonella antigens (Ags), the PL intensity is found to decrease proportional to Ag concentrations in the range of 10 2 - 10 5 cell/ml. The possible mechanism of biosensor response is suggested and discussed.
We report on an indirect optical method for the determination of glucose via the detection of hydrogen peroxide (H
2
O
2
) that is generated during the glucose oxidase (GOx) catalyzed oxidation of ...glucose. It is based on the finding that the ultraviolet (~374 nm) and visible (~525 nm) photoluminescence of pristine zinc oxide (ZnO) nanoparticles strongly depends on the concentration of H
2
O
2
in water solution. Photoluminescence is quenched by up to 90 % at a 100 mM level of H
2
O
2
. The sensor constructed by immobilizing GOx on ZnO nanoparticles enabled glucose to be continuously monitored in the 10 mM to 130 mM concentration range, and the limit of detection is 10 mM. This enzymatic sensing scheme is supposed to be applicable to monitoring glucose in the food, beverage and fermentation industries. It has a wide scope in that it may be extended to numerous other substrate or enzyme activity assays based on the formation of H
2
O
2
, and of assays based on the consumption of H
2
O
2
by peroxidases.
Graphical Abstract
We report the application of ZnO nanoparticles (NPs) in a biosensor for monitoring glucose at a large concentration range. The biosensor is based on the indirect detection of hydrogen peroxide via the respective change of the UV and visible PL of ZnO NPs.
El presente artículo es el producto de una investigación que tuvo como objetivo establecer la relación de la analizar la gestión de la convivencia escolar y el liderazgo de los estudiantes en las ...Instituciones educativas del municipio Valledupar. Se fundamentó en el método de holopráxico con un diseño de campo, contemporáneo y transeccional. Como instrumento se aplicó un cuestionario con escalamiento Likert que permitió la agrupación de un conjunto de preguntas con las alternativas de respuesta Siempre, Casi Siempre, A Veces, Casi Nunca y Nunca. El universo total objeto del estudio estuvo integrado en su fase cuantitativa, por dos poblaciones. Una de 55 sujetos que estructuraron el estamento directivo docente. Y, la otra fue la de los estudiantes cuyo universo poblacional fue de 1278 sujetos de los grados Noveno, Décimo y Undécimo en las Instituciones educativas: Casimiro Raúl Maestre, Leónidas Acuña y Enrique Pupo Martínez, de los cuales se determinó una muestra con el uso de la ecuación propuesta por Sierra Bravo, luego se calculó el muestreo, para lo cual se dividió la población de interés en grupos mutuamente excluyentes y colectivamente exhaustivos llamados estratos empleando la fórmula de Shiffer quedando una muestra definitiva de 139 discentes. Se concluyó que en resultados se observó que el valor de significancia es 0,000 < 0,05, lo que afirma que existe una relación estadísticamente significativa entre las sinergias: gestión de convivencia escolar desde el liderazgo de los estudiantes en las Instituciones educativas del municipio Valledupar, Colombia.
Today's digital electronics and fast computers allow the efficiently processing of large volumes of spectroscopic information, which means the opportunity to reuse and upgrade monochromator with ...sophisticated optical and mechanical systems being designed and used in the middle of the last century. Particular interest is towards high-resolution prism monochromator. We used such an approach to computerize manual operations of universal mirror monochromator SPM-2, which has changeable quartz, glass, NaCl and KBr crystal prisms. SPM-2 was produced by VEB Carl Zeiss JENA in the early sixties of the last century (in former GDR), and its advanced features were widely used 1. The current interest is to use upgraded double pass SPM-2 (with quartz prisma) for atomic spectroscopy measurements in broad intensity range in near VUV, far UV, UV. Alongside standard measurements, cooled photomultipliers, photon counting mode can be used to ensure the fixing of very weak spectroscopic lines. We are using the instrument to investigate resonance spectra of atomic iodine, bromine, arsenic, selenium, tellurium, boron. Particularly duplet of atomic boron resonance lines 249.6769/249.7722 nm is easily resoluble. The approach has a high value for money because of the absence of handy monochromators for high-resolution atomic spectroscopy in the identified spectral region on the market.
We report on an indirect optical method for the determination of glucose via the detection of hydrogen peroxide (H 2 O 2 ) that is generated during the glucose oxidase (GOx) catalyzed oxidation of ...glucose. It is based on the finding that the ultraviolet (~374 nm) and visible (~525 nm) photoluminescence of pristine zinc oxide (ZnO) nanoparticles strongly depends on the concentration of H 2 O 2 in water solution. Photoluminescence is quenched by up to 90 % at a 100 mM level of H 2 O 2 . The sensor constructed by immobilizing GOx on ZnO nanoparticles enabled glucose to be continuously monitored in the 10 mM to 130 mM concentration range, and the limit of detection is 10 mM. This enzymatic sensing scheme is supposed to be applicable to monitoring glucose in the food, beverage and fermentation industries. It has a wide scope in that it may be extended to numerous other substrate or enzyme activity assays based on the formation of H 2 O 2 , and of assays based on the consumption of H 2 O 2 by peroxidases.
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