Influence of 60-MeV Proton-Irradiation on Standard and Strained n- and p-Channel MuGFETs

In this work the proton irradiation influence on Multiple Gate MOSFETs (MuGFETs) performance is investigated. This analysis was performed through basic and analog parameters considering four different splits (unstrained, uniaxial, biaxial, uniaxial+biaxial). Although the influence of radiation is more pronounced for p-channel devices, in pMuGFETs devices, the radiation promotes a higher immunity to the back interface conduction resulting in the analog performance improvement. On the other hand, the proton irradiation results in a degradation of the post-irradiated n-channel transistors behavior. The unit gain frequency showed to be strongly dependent on stress efficiency and the radiation results in an increase of the unit gain frequency for splits with high stress effectiveness for both cases p- and nMuGFETs.

Organic and inorganic sources of zinc, copper and selenium in diets for dairy cows: intake, blood metabolic profile, milk yield and composition

The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn), copper (Cu) and selenium (Se) on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9) or inorganic (n = 10) sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS) was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.

Desnutrição em crianças menores de 60 meses em dois municípios no Estado do Acre: prevalência e fatores associados

OBJETIVO: Investigar a prevalência da desnutrição e fatores associados em crianças menores de 60 meses em dois municípios do Estado do Acre. MÉTODOS: Estudo transversal de base populacional realizado com 667 crianças da área urbana dos municípios de Acrelândia e Assis Brasil. A prevalência da desnutrição foi calculada pelo padrão de crescimento da Organização Mundial da Saúde de 2006, com o ponto de corte -2 escores Z. Informações sobre condições socioeconômicas, acesso aos serviços e cuidado da criança, peso ao nascer e morbidade foram obtidas por questionário estruturado. A regressão de Poisson foi utilizada para identificar os fatores associados à desnutrição de crianças. RESULTADOS: A prevalência do déficit estatura para idade e déficit peso para estatura foi de 9,9% e 4,1%, respectivamente. Os fatores associados ao déficit estatura para idade foram o baixo índice de riqueza (razão de prevalência [RP]: 1,74; intervalo de confiança em 95% [IC95%]: 0,95 - 3,18), analfabetismo do pai ou padrasto (RP: 1,82; IC95%: 1,01 - 3,27), ter 2 ou mais irmãos menores (RP: 2,88; IC95%: 1,45 - 5,72), ausência da mãe biológica no domicílio (RP: 2,63; IC95%: 1,32 - 5,24) e exposição ao esgoto a céu aberto no âmbito domiciliar (RP: 2,46; IC95%: 1,51 - 4,00). Somente o baixo peso ao nascer mostrou-se como fator associado ao déficit peso para estatura (RP: 2,91; IC95%: 1,16 - 7,24). CONCLUSÕES: Nos municípios estudados, a desnutrição em crianças menores de 60 meses apresenta-se como um importante problema de saúde pública, associado aos indicadores de iniquidades sociais, acesso aos serviços de saúde e ausência da mãe no domicílio.

Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients

BACKGROUND: Porphyria cutanea tarda is the most common form of porphyria, characterized by the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several reports associated HFE gene mutations of hereditary hemochromatosis with porphyria cutanea tarda worldwide, although up to date only one study has been conducted in Brazil. OBJECTIVES: Investigation of porphyria cutanea tarda association with C282Y and H63D mutations in the HFE gene. Identification of precipitating factors (hepatitis C, HIV, alcoholism and estrogen) and their link with HFE mutations. METHODS: An ambispective study of 60 patients with PCT was conducted during the period from 2003 to 2012. Serological tests for hepatitis C and HIV were performed and histories of alcohol abuse and estrogen intake were investigated. HFE mutations were identified with real-time PCR. RESULTS: Porphyria cutanea tarda predominated in males and alcohol abuse was the main precipitating factor. Estrogen intake was the sole precipitating factor present in 25% of female patients. Hepatitis C was present in 41.7%. All HIV-positive patients (15.3%) had a history of alcohol abuse. Allele frequency for HFE mutations, i.e., C282Y (p = 0.0001) and H63D (p = 0.0004), were significantly higher in porphyria cutanea tarda patients, compared to control group. HFE mutations had no association with the other precipitating factors. CONCLUSIONS: Alcohol abuse, hepatitis C and estrogen intake are prevalent precipitating factors in our porphyria cutanea tarda population; however, hemochromatosis in itself can also contribute to the outbreak of porphyria cutanea tarda, which makes the research for HFE mutations necessary in these patients

Layer-by-Layer assembled cobalt ferrite nanoparticles for chemical sensing

Ultra-thin (thicknesses of 50-90 nm) nanocomposite films of cobalt ferrite nanoparticles (np-CoFe2O4, 18 nm in diameter) and polyelectrolytes (doped polyaniline-PANI, poly-3,4-ethylenedioxy thiophene: polystyrene sulfonic acid-PEDOT:PSS, and sulfonated lignin-SL) are assembled layer-by-layer onto interdigitated microelectrodes aiming at to create novel nanostructured sensoactive materials for liquid media chemical sensors. The nanocomposites display a distinctive globular morphology with nanoparticles densely-packed while surrounded by polyelectrolytes. Due to the presence of np-CoFe2O4 the nanocomposites display low electrical conductivity according to impedance data. On the other hand, this apparent shortcoming turns such nanocomposites much more sensitive to the presence of ions in solution than films made exclusively of conducting polyelectrolytes. For example, the electrical resistance of np-CoFe2O4/PEDOT:PSS and PANI/SL/np-CoFe2O4/SL architectures has a 10-fold decrease when they are immersed in 20 mmol. L-1 NaCl solution. Impedance spectra fitted with the response of an equivalent circuit model suggest that the interface created between nanoparticles and polyelectrolytes plays a major role on the nanocomposites electrical/dielectrical behavior. Since charge transport is sensitive to nanoparticle-polyelectrolyte interfaces as well as to the physicochemical conditions of the environment, the np-CoFe2O4-based nanocomposites can be used as sensing elements in chemical sensors operated under ac regime and room temperature.

Dielectric properties of cobalt ferrite nanoparticles in ultrathin nanocomposite films

Multilayered nanocomposite films (thickness 50-90 nm) of cobalt ferrite nanoparticles (np-CoFe2O4, 18 nm) were deposited on top of interdigitated microelectrodes by the layer-by-layer technique in order to study their dielectric properties. For that purpose, two different types of nanocomposite films were prepared by assembling np-CoFe2O4 either with poly(3,4-ethylenedioxy thiophene):poly(styrene sulfonic acid) or with polyaniline and sulfonated lignin. Despite the different film architectures, the morphology of both was dominated by densely-packed layers of nanoparticles surrounded by polyelectrolytes. The dominant effect of np-CoFe2O4 was also observed after impedance spectroscopy measurements, which revealed that dielectric behavior of the nanocomposites was largely influenced by the charge transport across nanoparticle-polyelectrolyte interfaces. For example, nanocomposites containing np-CoFe2O4 exhibited a single low-frequency relaxation process, with time constants exceeding 15 ms. At 1 kHz, the dielectric constant and the dissipation factor (tan ᵟ) of these nanocomposites were 15 and 0.15, respectively. These values are substantially inferior to those reported for pressed pellets made exclusively of similar nanoparticles. Impedance data were further fitted with equivalent circuit models from which individual contributions of particle's bulk and interfaces to the charge transport within the nanocomposites could be evaluated. The present study evidences that such nanocomposites display a dielectric behavior dissimilar from that exhibited by their individual counterparts much likely due to enlarged nanoparticle- polyelectrolyte interfaces.

Prevalencia del déficit de vitamina B12 en mayores de 60 años hospitalizados. Estudio del polimorfismo C677T de la enzima 5-10 MTHFR en pacientes con déficit de vitamina B12

Programa de doctorado: Avances en Medicina Interna.

Evaluación de la calidad de vida de los pacientes entre 18 y 60 años de la Comunidad Autónoma de Canarias portadores de implante coclear

Programa de doctorado: Nuevas perspectivas en cirugía