Spectral characteristics of side face excited microstructured fibers for photonic integrated circuits formations

We propose a new method for mass production of the photonic crystal devices on the basis of widely-known and well-developed technology such as microstructured optical fibers. In this paper, we investigate the optical properties of side-excited microstructured optical fiber and discuss the conditions for utilization such a structure as a planar photonic crystal device, namely, the high-quality resonance filter.Comment: 7 pages, 7 figure

Refractive index sensing setup based on a taper and an intrinsic micro Fabry-Perot interferometer

In this work, a refractive index sensor setup based on a biconically tapered fiber (BTF) concatenated to an intrinsic all-fiber micro Fabry-Perot interferometer (MFPI) is presented. Here, the power of the MFPI spectral fringes decreases as the refractive index interacts with theevanescent field of the BTF segment. Furthermore, it is demonstrated that the RI sensitivity can be enhanced by bending the BTF segment.Finally, it is shown that by using this sensing arrangement, at ~1.53 µm wavelength, it is possible to detect refractive index changeswithin the measurement range of 1.3 to 1.7 RIU, with a sensitivity of 39.92 dB/RIU and a RI resolution of 2.5 x 10^-3 RIU with a curvature of C = 18.02 m^-1

Selective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products

11 pags, 8 figs, 3 tabs. -- Supplementary data to this article can be found online at https://doi.org/10.1016/j.jphotochem.2021.113513.Valorization of lignin into high valuable chemical is a critical challenge. Its availability is a key factor for the development of viable lignocellulosic processes to replace fossil derived compounds. In this work, new insights on the high photocatalytic conversion of guaiacol (82%) as a lignin model compound was achieved, also, high selectivity to p-benzoquinone (59%), catechol (27%), and pyrogallol (6%) was obtained using metal-free pyrolyzed g-C3N4 under visible light irradiation. To highlight the new insights, experimental parameters were modified to control the reaction mechanism to increase selectivity and photo-conversion. g-C3N4 photocatalyst was synthesized through urea calcination at 550 ◦C and the photocatalytic performance was assessed in terms of pyrolysis time, where higher time resulted in better photocatalytic activity. This effect was attributed to smaller structures and therefore better quantum confinement of the charges. The oxidation was promoted by •OH radicals, which were detected through EPR operando mode and the addition of radical scavengers. A reaction pathway was proposed, in which the ⋅OH attacks guaiacol through a methoxy group. The photocatalytic reaction can be tuned using external oxidant agents such as O2 and/or H2O2 to promote certain radical formation, enhancing conversion rates and promoting selectivity for a specific product, where yield shifting from p-benzoquinone to pyrogallol was experimentally observed.The authors thank the funding from ANID Millennium Science Initiative Program NCN17_040, Fondequip EQM150101, EQM160070, Fondecyt proyect No 3210554 and PIA CCTE AFB 170007 projects. To VRI Puente Project No 3913-556-81 and Proyecto Apoyo Investigacion Basica 3913-406-81 at PUC Chile and DICYT-USACH for financial support. To PID2019-107106RB-C32 project funded by the Spanish Ministry of Science and Innovation for financial support. The use of Servicio General de Apoyo a la Investigacion (SAI, University of Zaragoza) is also acknowledged.Peer reviewe

Selective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products (vol 421, 113513, 2021)

1 pag. -- Refers to: Selective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products Journal of Photochemistry and Photobiology A: Chemistry, volume 421, 1 December 2021, Pages 113513The authors regret that in the above article, affiliation c is mistaken. Therefore, afiliation c should be: c Departamento de Química de los materiales, Laboratorio de electroquímica Medio ambiental, LEQMA, Universidad de Santiago de Chile, Avenida Libertador Bernardo O'Higgins 3363, Estación Central, Santiago 9170376, Chile The authors would like to apologize for any inconvenience caused.Peer reviewe

Human Rabies and Rabies in Vampire and Nonvampire Bat Species, Southeastern Peru, 2007

After a human rabies outbreak in southeastern Peru, we collected bats to estimate the prevalence of rabies in various species. Among 165 bats from 6 genera and 10 species, 10.3% were antibody positive; antibody prevalence was similar in vampire and nonvampire bats. Thus, nonvampire bats may also be a source for human rabies in Peru

Single-mode Bragg gratings in tapered few-modes and multimode fibers

We propose the implementation of fiber Bragg gratings in tapered few-modes, and multimode fibers to accomplish single-mode operation by reducing the core diameter while preserving the core-cladding structure. Gratings present a single reflection band and the device show low insertion losses after the taper fabrication and the fiber Bragg gratings inscription. The excitation of high order odd-modes in the core of the fiber has been identified as the main loss mechanism; it can be prevented by means of symmetric illumination of the fibers. We also demonstrate the excitation of high order cladding modes (cladding-air modes) along the taper transitions; these modes can be removed without a significant increment of the insertion loss

7th Drug hypersensitivity meeting: part two

No abstract availabl

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Calibration of a gas sensor based on cross-correlation spectroscopy

In this work an analysis of some calibration effects in the overall response of a gas sensor based on cross-correlation spectroscopy is presented. For this analysis we considered that an FPI with long cavity length (>500 µm) acting as a modulator and a pyroelectric detector are used. Moreover we assumed that the cavity length of the FPI is scanned by driving a PZT with a triangular waveform. Here it is shown that the harmonic composition of the overall sensor response can be affected by small FPI cavity length differences. These effects are due to the pyroelectric responsivity and the triangular waveform used to scan the PZT. Moreover it is shown that the effects over the harmonic composition can be used to calibrate the sensor. Finally simulation results and experimental measurements are provided

Fiber optic fabry-perot micro-displacement sensor based on low-cost polymer film

This manuscript experimentally validates a thin-film polymer andmultimode fiber optic interaction-based low-cost optical fiber displacement sensor. The sensing setup is operated by deflecting a commerciallyMylar® polymer film using multimode optical fiber. The sensor exhibits a higher sensitivity of 24nm/μmand resolution of 41.6nm. The sensor’s analyses also demonstrate good polynomial approximation, with a maximal adjusted square of R = 0.9801, and high stability, in which minimal power (0.4dB-Hour) and wavelength (<2nm-Hour) variations are observed. Moreover, thermal experiments prove that the sensor has lower temperature traits (0.05μm/ C), and this parameter can be distinguished considering the wavelength shifting direction. The simplicity of the scheme, as well as the cost of the elements involved, make this technique a reliable alternative to detect microdisplacements