Influence of UV Radiation on Mechanical Properties of Polymer Optical Fibers.

This paper presents an analysis of the mechanical properties of different polymer optical fibers (POFs) at ultraviolet (UV) radiation conditions. Cyclic transparent optical polymer (CYTOP) and polymethyl methacrylate (PMMA) optical fibers are used in these analyses. In this case, the fiber samples are irradiated at the same wavelength, pulse time and energy conditions for different times, namely, 10 s, 1 min, 2 min and 3 min. The samples are tested in tensile tests and dynamic mechanical thermal analysis (DMTA) to infer the variation in the static and dynamic properties of such fibers as a function of the UV radiation condition. Furthermore, reference samples of each fiber (without UV radiation) are tested for comparison purposes. The results show a lower UV resistance of PMMA fibers, i.e., higher variation in the material features in static conditions (Young's modulus variation of 0.65 GPa). In addition, CYTOP fiber (material known for its high UV resistance related to its optical properties) also presented Young's modulus variation of around 0.38 GPa. The reason for this reduction in the moduli is related to possible localized annealing due to thermal effects when the fibers are subjected to UV radiation. The dynamic results also indicated a higher variation in the PMMA fibers storage modulus, which is around 30% higher than the variations in the CYTOP fibers when different radiation conditions are analyzed. However, CYTOP fibers show a smaller operational temperature range and higher variation in the storage modulus as a function of the temperature when compared with PMMA fibers. In contrast, PMMA fibers show higher variations in their material properties when subjected to oscillatory loads at different frequency conditions. Thus, the results obtained in this work can be used as guidelines for the influence of UV radiation in POFs not only for the material choice, but also on the limitations of UV radiation in the fabrication of the grating as well as in sensor applications at UV radiation conditions.

Perrogator: A Portable Energy-Efficient Interrogator for Dynamic Monitoring of Wavelength-Based Sensors in Wearable Applications.

In this paper, we report the development of a portable energy-efficient interrogator (Perrogator) for wavelength-based optical sensors. The interrogator is based on a compact solution encompassing a white light source and the spectral convolution between the sensor and a tunable filter, which is acquired by a photodetector, where a microcontroller has two functions: (i) To control the filter tuning and to (ii) acquire the photodetector signal. Then, the data is sent to a single-board computer for further signal processing. Furthermore, the employed single-board computer has a Wi-Fi module, which can be used to send the sensors data to the cloud. The proposed approach resulted in an interrogator with a resolution as high as 3.82 pm (for 15.64 nm sweeping range) and maximum acquisition frequency of about 210 Hz (with lower resolution ~15.30 pm). Perrogator was compared with a commercial fiber Bragg grating (FBG) interrogator for strain measurements and good agreement between both devices was found (1.226 pm/µÎµ for the commercial interrogator and 1.201 pm/µÎµ for the proposed approach with root mean square error of 0.0144 and 0.0153, respectively), where the Perrogator has the additional advantages of lower cost, higher portability and lower energy consumption. In order to demonstrate such advantages in conjunction with the high acquisition frequency allowed us to demonstrate two wearable applications using the proposed interrogation device over FBG and Fabry-Perot interferometer (FPI) sensors. In the first application, an FBG-embedded smart textile for knee angle assessment was used to analyze the gait of a healthy person. Due to the capability of reconstructing the FBG spectra, it was possible to employ a technique based on the FBG wavelength shift and reflectivity to decouple the effects of the bending angle and axial strain on the FBG response. The measurement of the knee angle as well as the estimation of the angular and axial displacements on the grating that can be correlated to the variations of the knee center of rotation were performed. In the second application, a FPI was embedded in a chest band for simultaneous measurement of breath and heart rates, where good agreement (error below 5%) was found with the reference sensors in all analyzed cases.

Low-Cost Interrogation Technique for Dynamic Measurements with FBG-Based Devices.

Fiber Bragg gratings are widely used optical fiber sensors for measuring temperature and/or mechanical strain. Nevertheless, the high cost of the interrogation systems is the most important drawback for their large commercial application. In this work, an in-line Fabry-Perot interferometer based edge filter is explored in the interrogation of fiber Bragg grating dynamic measurements up to 5 kHz. Two devices an accelerometer and an arterial pulse wave probe were interrogated with the developed approach and the results were compared with a commercial interrogation monitor. The data obtained with the edge filter are in agreement with the commercial device, with a maximum RMSE of 0.05 being able to meet the requirements of the measurements. Resolutions of 3.6 pm and 2.4 pm were obtained, using the optical accelerometer and the arterial pulse wave probe, respectively.

Anatomia e análise de óleo essencial das folhas de Hennecartia omphalandra J Poisson (Monimiaceae) / Anatomy and essential oil analysis of the leaves from Hennecartia omphalandra J Poisson (Monimiaceae)

Descreve-se a morfo-anatomia e a análise de óleo essencial das folhas de Hennecartia omphalandra J. Poisson (Monimiaceae), uma planta tóxica. A ocorrência de tricomas unicelulares, estômatos paracíticos; braquiesclereídes em grupos no pecíolo e na lâmina foliar, além de esclereídes vermiformes e ramiformes; sistema vascular em arco, com extremidades voltadas para o centro no pecíolo e na forma de arco atenuado na lâmina foliar, sendo o padrão de venação uma variação do tipo craspedódromo-semicraspedódromo, além de óleo essencial armazenado em idioblastos oleíferos não especializados no mesofilo, foram considerados caracteres importantes que podem auxiliar na sua morfo-diagnose. A análise do óleo essencial das folhas revelou a presença de monoterpenos, sesquiterpenos e álcoois sesquiterpênicos, sendo este o grupo mais significativo. Os componentes majoritários identificados foram β-felandreno (24,0 por cento), seguido por germacreno D (10,5 por cento), sabineno (9,3 por cento), biciclogermacreno (8,4 por cento) e β-elemeno (5,3 por cento).

This paper describes the morphological and anatomical aspects and the essential oil analysis of the leaves from Hennecartia omphalandra J. Poisson (Monimiaceae), a toxic plant. The presence of trichomes formed by a single cell, paracitic stomata, groups of braquisclereids in the petiole and leaf blade; vermiform and ramiform sclereids, vascular system in arc softly invaginated at ends in the petiole, and in a flat arc in the middle vein, being the venation pattern a variation of craspedodromous-semicraspedodromous type, and essential oil stored in oil idioblasts in the mesophyll were the most important characters that can help the morphological diagnosis. The analysis of essential oil of the leaves showed the presence of monoterpenes, as well as sesquiterpenes hydrocarbons and alcohols, being the latter the most significant group. The major identified compounds were β-phelandrene (24.0 percent), germacrene D (10.5 percent), sabinene (9.3 percent), bicyclogermacrene (8.4 percent) and β-elemene (5.3 percent).

Considerações anatômicas e análise de óleo essencial do hipanto e do fruto de Hennecartia omphalandra J. Poisson (Monimiaceae) / Anatomical considerations and essential oil analysis of the hypanthium and the fruit of Hennecartia omphalandra J. Poisson (Monimiaceae)

Descreve-se o estudo morfo-anatômico e a análise de óleo essencial do fruto de Hennecartia omphalandra J. Poisson (Monimiaceae), uma planta tóxica. A ocorrência de feixes recurrentes e de um anel descontínuo de braquiesclereides no hipanto; assim como a presença de células oleíferas no mesocarpo, de "idioesclereídes" formando o endocarpo e de células com espessamento parietal em rede, constituindo a testa da semente, foram considerados caracteres importantes que podem auxiliar na sua morfo-diagnose. A análise do óleo essencial dos frutos revelou a presença de monoterpenos, sesquiterpenos e álcoois sesquiterpênicos, sendo este o grupo mais significativo. Os componentes majoritários identificados foram o biciclogermacreno (19,6 por cento) e o β-felandreno (8,7 por cento), além do germacreno D (5,3 por cento), α-bulneseno (5,1 por cento) e valerianol (4,9 por cento).

The morphological and anatomical aspects of flower and fruit and the essential oil analysis of fruits of Hennecartia omphalandra J. Poisson (Monimiaceae), a toxic plant, are described in this paper. The presence of vascular recurrent bundles and of a ring of brachysclereids in the hypanthium; the oil cells in the mesocarp, the "idiosclereids" that constitutes the endocarp and cells with reticulated thick walls, shaping the seed coat were described as characters that may help in its diagnosis. The analysis of the essential oil of fruits showed the presence of monoterpenes, as well as sesquiterpenes hydrocarbons and alcohols, being the latter the most significant group. The major identified compounds were bicyclogermacrene (19.6 percent); β-felandrene (8.7 percent); germacrene D (5.3 percent); α - bulnesene (5.1 percent) and valerianol (4.9 percent).

Neurossífilis congênita: ainda um grave problema de saúde pública / Congenital neurosyphilis: yet a severe problem of public health

Introdução: a sífilis é grave quando transmitida para o feto e invade o sistema nervoso central (SNC). Entretanto, o diagnóstico correto de neurossífilis congênita (NSC) é um dilema, pois testes para sífilis reagentes no LCR são raros. Como critério indireto, o nível mínimo de proteinorraquia passou de 100 para 150 mg/dL, segundo o Ministério da Saúde, em 2003. Objetivo: verificar a prevalência de sífilis congênita (SC) e NSC, avaliar a taxa de falso-positivos (FP) e verdadeiro-positivos (VP) do critério antigo e determinar as diferenças nos títulos de VDRL materno e neonatal e a evolução clínica entre os FP e os VP. Métodos: dados secundários de casos notificados como SC e NSC da Maternidade da Universidade de Pernambuco - Nordeste do Brasil, no período de junho de 1998 a junho de 2003, constituíram um banco de dados e análise pelo Epiinfo, versão Windows 3.3.2. Os dois critérios de NSC foram comparados, por estudo transversal analítico e de validação de teste diagnóstico, verificaram-se os percentuais de FP e VP do critério antigo e adotou-se o teste do qui-quadrado para a avaliação das diferenças de títulos de VDRL e ocorrências neonatais entre os FP e os VP. Resultados: 1.036 entre 32.246 nascidos vivos (3,21%) foram diagnosticados com SC, 360 (34,7%) tinham NSC pelo critério antigo, 282 (27,2%) confirmados pelo critério novo (78,3% dos antigos), representando 78 casos (21,7%) de FP. Não houve diferença significante (p > 0,05) entre os títulos de VDRL e ocorrências (icterícia, infecção, conjuntivite e hipoxia) entre os FP e os VP. Conclusão: a SC, principalmente a NSC, permanece como um grave problema de saúde pública.

Introduction: Syphilis is severe when it is transmitted from mother to child and invades the NSC. However, the correct diagnosis of congenital neurosyphilis(NCS) is a dilemma, because reagents syphilis’s tests in CRL are rare. As indirect criterion the minimum level of protein in CRL changed from 100 to 150 mg/dL, according to the Ministry of Health in Brazil, in 2003. Objectives: verifying congenital syphilis (CS) and CNS, studying the rate of false positive (FP) and true positive (TP) of last criterion and determine differences between titles of maternal and neonatal VDRL and clinical evolutions between FP e TP. Methods: secondary data of notified cases of CS and CNS from the Maternity of the University of Pernambuco - Northeast of Brazil, from June 1998 to June 2003, constituted the data and analysis bank by Epiinfo, version Windows 3.3.2. The two criteria of CNS were compared by analytic transversal and validation of diagnostic test studies, the FP and TP of the last criterion were verified and qui square were applied to determine differences between VDRL titles and neonatal occurrences between FP and TP. Results: 1,036 from 32,246 births (3.21%) had been diagnosed as CS, 360 (34.7%) had CNS by last criterion, 282 (27,2%) confirmed by new criterion (78,3% of last), representing 78 FP cases (21.7%). There were no significant differences (p > 0.05) between VDRL titles and occurrences (jaundice, infections, conjunctivitis and hypoxia) between FP and TP. Conclusion: CS, mainly CNS, continue like a severe problem oh public health.