Optimized Multimode Interference Fiber Based Refractometer in A Reflective Interrogation Scheme

A fiber based refractometer in a reflective interrogation scheme is investigated and optimized. A thin gold film was deposited on the tip of a coreless fiber section, which is spliced with a single mode fiber. The coreless fiber is a multimode waveguide, and the observed effects are due to multimode interference. To investigate and optimize the structure, the multimode part of the sensor is built with 3 different lengths: 58 mm, 29 mm and 17 mm. We use a broadband light source ranging from 1475 nm to 1650 nm and we test the sensors with liquids of varying refractive indices, from 1.333 to 1.438. Our results show that for a fixed wavelength, the sensor sensitivity is independent of the multimode fiber length, but we observed a sensitivity increase of approximately 0.7 nm/RIU for a one-nanometer increase in wavelength

Evolution of density perturbations in decaying vacuum cosmology: The case of non-zero perturbations in the cosmological term

We extend the results of a previous paper where a model of interacting dark energy, with a cosmological term decaying linearly with the Hubble parameter, is tested against the observed mass power spectrum. In spite of the agreement with observations of type Ia supernovas, baryonic acoustic oscillations and the cosmic microwave background, we had shown previously that no good concordance is achieved if we include the mass power spectrum. However, our analysis was based on the ad hoc assumption that the interacting cosmological term is strictly homogeneous. Now we perform a more complete analysis, by perturbing such a term. Although our conclusions are still based on a particular, scale invariant choice of the primordial spectrum of dark energy perturbations, we show that a cosmological term decaying linearly with the Hubble parameter is indeed disfavored as compared to the standard model.Comment: Version accepted for publication in Physical Review

Enhancing the Sensitivity of SMS Fiber Sensors by the Use of High Refractive Index Coatings

This paper presents a study on the behavior of single-mode/multimode/single-mode sensors with diamond-like carbon coating of high refractive index. Spectra and response for different values of the external medium refractive index are recorded and analyzed

Gastric Antral Vascular Ectasia (GAVE) and Hereditary Hemorrhagic Telangiectasia (HHT): Two Different Conditions, One Treatment

info:eu-repo/semantics/publishedVersio

Carotenoides Pro-vitamina A em frutos de bananeira.

Os tipos de carotenóides variam muito nas frutas, sendo que aproximadamente 50 carotenóides possuem atividade pró-vitamina A. Dentre esses o β-caroteno é o mais importante e abundante em alimentos, seguido do α-caroteno e β-criptoxantina, os quais possuem a metade da atividade de vitamina A, comparativamente ao primeiro caroteno. Outros carotenóides não pró-vitamina A, porém com efeitos relevantes à saúde humana (e.g., antioxidante, antitumoral e inibidores da degeneração macular), também ocorrem em alimentos (luteína, zeaxantina e licopeno, por exemplo - RODRIGUEZ-AMAYA, 2001) e sua identificação em frutos de bananeira é considerado relevante. A banana destaca-se pelo seu alto potencial como alimento funcional, devido a seu alto consumo, principalmente em países subdesenvolvidos

Colite a CMV Mimetizando Tumor Rectal num Doente com VIH Não Diagnosticado

Introduction: Cytomegalovirus (CMV) is the most common opportunistic agent in HIV-infected patients. It can affect the entire gastrointestinal tract, but frequently involves the oesophagus and the colon. Case Report: We report the case of a 70-year-old female, ultimately diagnosed with HIV infection, whose inaugural clinical manifestation was CMV colitis with endoscopic findings resembling a rectal tumour in which initial histological evaluation was not able to provide a proper diagnosis. Discussion/Conclusion: Since clinical presentation is variable and histopathological yield without immunohistochemical analysis is poor, recognizing CMV infection in the absence of known risk factors may be difficult. It is crucial to consider this entity with suspicious lesions or when initial evaluation, either clinical or histopathological, is inconclusive, thus avoiding potentially debilitating and superfluous treatment or life-threatening complications.info:eu-repo/semantics/publishedVersio