Clinical Features of COVID-19 on Patients With Neuromyelitis Optica Spectrum Disorders.

Background And Objectives: To describe the clinical features and disease outcomes of coronavirus disease 2019 (COVID-19) in patients with neuromyelitis optica spectrum disorder (NMOSD).

Methods: The Neuroimmunology Brazilian Study Group has set up the report of severe acute respiratory syndrome (SARS-CoV2) cases in patients with NMOSD (pwNMOSD) using a designed web-based case report form. All neuroimmunology outpatient centers and individual neurologists were invited to register their patients across the country.

Self-reported adherence among people with epilepsy in Brazil.

Background: Nonadherence rates among people with epilepsy (PWE) are widely variable, ranging from 26% to 95.4%. We aimed to identify nonadherence in Brazil, its determinant factors, its impact on patients' management, and to compare it with other chronic nonparoxysmal diseases.

[Symptoms and upper limb work-related musculo-skeletal disorders among 173 supermarket cashiers].

Background: Cashiers in supermarket chains have long been considered at risk for the development of work related musculo-skeletal disorders of the upper limbs (UL-WMSDs). The aim of this study was to assess the prevalence of UL-WMSDs among workers operating supermarket cash tills and, after clinical tests, their frequency.

Methods: A standardized questionnaire was given to a random group of 173 workers in order to collect information regarding symptoms in the upper limbs (pain and parasthesia).

Q-switching and efficient harmonic generation from a single-mode LMA photonic bandgap rod fiber laser.

We demonstrate a Single-Mode (SM) Large-Mode-Area (LMA) ytterbium-doped PCF rod fiber laser with stable and close to diffraction limited beam quality with 110W output power. Distributed-Mode-Filtering (DMF) elements integrated in the cladding of the rod fiber provide a robust spatial mode with a Mode-Field-Diameter (MFD) of 59μm. We further demonstrate high pulse energy Second-Harmonic-Generation (SHG) and Third Harmonic Generation (THG) using a simple Q-switched single-stage rod fiber laser cavity architecture reaching pulse energies up to 1mJ at 515nm and 0.

Single-Mode ytterbium-doped Large-Mode-Area photonic bandgap rod fiber amplifier.

Enabling Single-Mode (SM) operation in Large-Mode-Area (LMA) fiber amplifiers and lasers is critical, since a SM output ensures high beam quality and excellent pointing stability. In this paper, we demonstrate and test a new design approach for achieving SM LMA rod fibers by using a photonic bandgap structure. The structure allows resonant coupling of higher-order modes from the core and acts as a spatially Distributed Mode Filter (DMF).

Electrically tunable Yb-doped fiber laser based on a liquid crystal photonic bandgap fiber device.

We demonstrate electrical tunability of a fiber laser using a liquid crystal photonic bandgap fiber. Tuning of the laser is achieved by combining the wavelength filtering effect of a tunable liquid crystal photonic bandgap fiber device with an ytterbium-doped photonic crystal fiber. We fabricate an all-spliced laser cavity based on the liquid crystal photonic bandgap fiber mounted on a silicon assembly, a pump/signal combiner with single-mode signal feed-through and an ytterbium-doped photonic crystal fiber.

Biased liquid crystal infiltrated photonic bandgap fiber.

A simulation scheme for the transmission spectrum of a photonic crystal fiber infiltrated with a nematic liquid crystal and subject to an external bias is presented. The alignment of the biased liquid crystal is simulated using the finite element method to solve the relevant system of coupled partial differential equations. From the liquid crystal alignment the full tensorial dielectric permittivity in the capillaries is derived.

Frequency tunability of solid-core photonic crystal fibers filled with nanoparticle-doped liquid crystals.

We infiltrate liquid crystals doped with BaTiO3 nanoparticles in a photonic crystal fiber and compare the measured transmission spectrum with the one achieved without dopant. New interesting features, such as frequency modulation response of the device and a transmission spectrum with tunable attenuation on the short wavelength side of the widest bandgap, suggest a potential application of this device as a tunable all-in-fiber gain equalization filter with an adjustable slope. The tunability of the device is achieved by varying the amplitude and the frequency of the applied external electric field.

Continuously tunable all-in-fiber devices based on thermal and electrical control of negative dielectric anisotropy liquid crystal photonic bandgap fibers.

We infiltrate photonic crystal fibers with a negative dielectric anisotropy liquid crystal. A 396 nm bandgap shift is obtained in the temperature range of 22-80 degrees C, and a 67 nm shift of long-wavelength bandgap edge is achieved by applying a voltage of 200 Vrms. The polarization sensitivity and corresponding activation loss are measured using polarized light and a full broadband polarization control setup.

Noise filtering in a multi-channel system using a tunable liquid crystal photonic bandgap fiber.

This paper reports on the first application of a liquid crystal infiltrated photonic bandgap fiber used as a tunable filter in an optical transmission system. The device allows low-cost amplified spontaneous emission (ASE) noise filtering and gain equalization with low insertion loss and broad tunability. System experiments show that the use of this filter increases for times the distance over which the optical signal-to-noise ratio (OSNR) is sufficient for error-free transmission with respect to the case in which no filtering is used.

Avoided-crossing-based liquid-crystal photonic-bandgap notch filter.

We demonstrate a highly tunable deep notch filter realized in a liquid-crystal photonic-bandgap (LCPBG) fiber. The filter is realized without inducing a long-period grating in the fiber but simply by filling a solid-core photonic-crystal fiber with a liquid crystal and exploiting avoided crossings within the bandgap of the LCPBG fiber. The filter is demonstrated experimentally and investigated using numerical simulations.

Electrically and mechanically induced long period gratings in liquid crystal photonic bandgap fibers.

We demonstrate electrically and mechanically induced long period gratings (LPGs) in a photonic crystal fiber (PCF) filled with a high-index liquid crystal. The presence of the liquid crystal changes the guiding properties of the fiber from an index guiding fiber to a photonic bandgap guiding fiber - a so called liquid crystal photonic bandgap (LCPBG) fiber. Both the strength and resonance wavelength of the gratings are highly tunable.

Development of educational tools to demonstrate the effects of hyper and microgravity on different test bodies.

Educational and outreach programs in space sciences have been a major concern since the beginning of the Space Era. Education curricula in Brazil rarely consider topics related to manned and unmanned space flight. This lack in the Brazilian education system has motivated the development of educational tools, used to demonstrate the effects of hyper- and microgravity on test bodies, both gravitational environments commonly found in aerospace missions.

Continuously tunable devices based on electrical control of dual-frequency liquid crystal filled photonic bandgap fibers.

We present an electrically controlled photonic bandgap fiber device obtained by infiltrating the air holes of a photonic crystal fiber (PCF) with a dual-frequency liquid crystal (LC) with pre-tilted molecules. Compared to previously demonstrated devices of this kind, the main new feature of this one is its continuous tunability due to the fact that the used LC does not exhibit reverse tilt domain defects and threshold effects. Furthermore, the dual-frequency features of the LC enables electrical control of the spectral position of the bandgaps towards both shorter and longer wavelengths in the same device.

Characterisation of the TAPIRO BNCT thermal facility.

Dosimetry and spectrometry measurements have been carried out in the thermal column of the research fast reactor RSV-TAPIRO (ENEA-Casaccia, Rome) in order to investigate its suitability for irradiation of cells or mice, with a view to research in the interests of boron neutron capture therapy (BNCT). The thermal column consists of a graphite moderator (40 cm thick) containing a lead shield (13 cm thick) in order to shield reactor background. The irradiation volume, inside this structure, has cubic shape (18 x 18 x 18 cm3).

Characterisation of the TAPIRO BNCT epithermal facility.

A collimated epithermal beam for boron neutron capture therapy (BNCT) research has been designed and built at the TAPIRO fast research reactor. A complete experimental characterisation of the radiation field in the irradiation chamber has been performed, to verify agreement with IAEA requirements. Slow neutron fluxes have been measured by means of an activation technique and with thermoluminescent detectors (TLDs).

Alanine and TLD coupled detectors for fast neutron dose measurements in neutron capture therapy (NCT).

A method was investigated to measure gamma and fast neutron doses in phantoms exposed to an epithermal neutron beam designed for neutron capture therapy (NCT). The gamma dose component was measured by TLD-300 [CaF2:Tm] and the fast neutron dose, mainly due to elastic scattering with hydrogen nuclei, was measured by alanine dosemeters [CH3CH(NH2)COOH]. The gamma and fast neutron doses deposited in alanine dosemeters are very near to those released in tissue, because of the alanine tissue equivalence.

Study of a method based on TLD detectors for in-phantom dosimetry in BNCT.

A method has been developed, based on thermoluminescent dosemeters (TLD), aimed at measuring the absorbed dose in tissue-equivalent phantoms exposed to thermal or epithermal neutrons, separating the contributions of various secondary radiation generated by neutrons. The proposed method takes advantage of the very low sensitivity of CaF2:Tm (TLD-300) to low energy neutrons and to the different responses to thermal neutrons of LiF:Mg,Ti dosemeters with different 6Li percentage (TLD-100, TLD-700, TLD-600). The comparison of the results with those obtained by means of gel dosemeters and activation foils has confirmed the reliability of the method.

Bone marrow percentage of plasma cells in the staging of monoclonal gammopathies.

In the present study, the relationships between percentage of bone marrow plasma cells (BMP%), tumor cell mass, stage, and survival are statistically analyzed in a large number (90) of monoclonal gammopathies (MG). Though BMP% has not been included among the criteria for the staging of multiple myeloma, our results indicate that the above mentioned parameters correlate at highly significant degrees. BMP% is therefore proposed as a new, useful parameter in the staging of MG.

[The nature of crystals in plasma cells present in a case of apparently benign biclonal gammapathy].

A 77 years old white man presents, in his blood serum, a moderate gammapathy with 2 monoclonal peaks, IgAk and IgGlambda, and in his urine a little quantity of BJk, without any clinical or radiological manifestation. The sternal bone marrow showed 3-5% plasmacells, mostly containing many needlelike inclusions in the cytoplasm. These inclusions, red-violet at the May-Grünwald-Giemsa, were PAS and Sudan negative; positive at the Danielli reaction (for proteins).

Late appearance of an IgA (kappa) monoclonal protein in a patient with IgG (kappa) multiple myeloma: sharing of idiotypic specificities between the two serum proteins.

A patient with an IgG(chi) monoclonal serum protein developed in the course of the disease a second monoclonal spike of the same light chain type and of the IgA class. The latter monoclonal protein progressively increased and eventually exceeded the first IgG(chi) protein. Antigenic analysis of the two myeloma proteins demonstrated that they shared idiotypic determinants.

Ultrastructural aspects of crystal-like inclusions in a case of IgA plasma cell proliferation.

A case of apparently benign plasma cell proliferation is described. Needle-like paracrystalline inclusions were observed in numerous plasma cells outside the cisternae of the rough endoplasmic reticulum. They had a dense protein core surrounded by a layer of carbohydrate.