Universidade Federal de Minas Gerais

About: Universidade Federal de Minas Gerais is a education organization based out in Belo Horizonte, Minas Gerais, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 41631 authors who have published 75688 publications receiving 1249905 citations.

The role of parasite persistence in pathogenesis of Chagas heart disease

Abstract: Summary Chagas disease (CD) is caused by the infection with the protozoan haemoflagellate Trypanosoma cruzi. This disease is still a great menace to public health, and is largely neglected as it affects mostly the poorest populations of Latin America. Nonetheless, there are neither effective diagnostic markers nor therapeutic options to accurately detect and efficiently cure this chronic infection. In spite of the great advances in the knowledge of the biology of natural transmission, as well as the immunobiology of the host–parasite interaction, the understanding of the pathogenesis of CD remains largely elusive. In the recent decades, a controversy in the research community has developed about the relevance of parasite persistence or autoimmune phenomena in the development of chronic cardiac pathology. One of the most notable aspects of chronic CD is the progressive deterioration of cardiac function, derived mostly from structural derangement, as a consequence of the intense inflammatory process. Here we review the evidence supporting the multifactorial nature of Chagas heart disease comprising pathogen persistence and altered host immunoregulatory mechanisms.

Quantifying carbon-nanotube species with resonance Raman scattering

Abstract: The method for quantifying the amount of each carbon nanotube specie, as defined by its diameter and chiral angle, as well as the semiconducting-to-metallic ratio in any type of carbon nanotube sample is discussed. Single-wall carbon nanotubes grown by the cobalt-molybdenum catalyst based (CoMoCAT) process are characterized. The semiconducting-to-metallic ratio is found to be 11:1. A single semiconducting specie, named the (6,5) nanotube represents $2∕5$ of the sample, while the most abundant metallic nanotube is the (7,4), which exhibits a diameter similar to the (6,5).

Validity of self-reported hypertension and its determinants (the Bambuí study)

Abstract: OBJETIVO: Determinar a validade da hipertensao auto-referida e seus determinantes em adultos residentes na comunidade. METODOS: Foi selecionada uma amostra aleatoria simples de moradores da cidade de Bambui, Estado de Minas Gerais, com 18 anos de idade ou mais. Tres medidas de pressao arterial foram realizadas em 970 individuos, que correspondiam a 89,3% dos selecionados. A sensibilidade, especificidade e os valores preditivos positivo e negativo da hipertensao auto-referida foram calculados em relacao a hipertensao (media da pressao arterial >90 ou >140 mmHg e/ou uso atual de medicamentos para hipertensao). RESULTADOS: A sensibilidade e a especificidade da hipertensao auto-referida foram 72,1% (IC 95%: 69,3-75,0) e 86,4% (IC 95%: 84,3-88,6), respectivamente. Sua prevalencia foi 27,2% (IC 95%: 24,4-30,1), sendo razoavelmente semelhante a da hipertensao (23,3%; IC 95%: 20,7-26,1%). A validade da hipertensao auto-referida foi maior entre mulheres, entre aqueles com idade igual a 40-59 e >60 anos, entre os que haviam visitado medicos mais recentemente ( 25 kg/m²). CONCLUSOES: Os resultados mostram que a hipertensao auto-referida e um indicador apropriado da prevalencia da hipertensao arterial, mesmo em uma populacao residente fora de grandes centros urbanos, e que os seus determinantes sao semelhantes ao observado em paises desenvolvidos.

Determination of LA and TO phonon dispersion relations of graphene near the Dirac point by double resonance Raman scattering

Abstract: Raman spectroscopy was used to determine the dispersion of the longitudinal acoustic (LA) and in-plane transverse optic phonon branches near the Dirac $K$ point of monolayer graphene from the analysis of the dispersion of two second-order Raman peaks involving the LA and TO phonons. We show that the velocities of the phonons involved in the double resonance Raman process are given by ${v}_{\mathit{LA}}=7.70\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}{v}_{F}$ and ${v}_{\mathit{TO}}=5.47\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}{v}_{F}$, where ${v}_{F}$ is the Fermi velocity of the associated electrons. The experimental results for the phonon dispersion in monolayer graphene are compared with those for turbostratic graphite and also with different theoretical models.