9 research outputs found
Measuring the strength of interaction between the ebola fusion peptide and lipid rafts: implications for membrane fusion and virus infection
9 p. : il., tab.The Ebola fusion peptide (EBO16) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola
virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromaticaromatic
interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently,
several steps still remain unclear, a lacuna that makes it difficult to develop strategies to block infection. In order to gain
insight into the mechanism of membrane fusion, we probed the structure, function and energetics of EBO16 and its mutant
W8A, in the absence or presence of different lipid membranes, including isolated domain-resistant membranes (DRM), a
good experimental model for lipid rafts. The depletion of cholesterol from living mammalian cells reduced the ability of
EBO16 to induce lipid mixing. On the other hand, EBO16 was structurally sensitive to interaction with lipid rafts (DRMs), but
the same was not observed for W8A mutant. In agreement with these data, W8A showed a poor ability to promote
membrane aggregation in comparison to EBO16. Single molecule AFM experiments showed a high affinity force pattern for
the interaction of EBO16 and DRM, which seems to be a complex energetic event as observed by the calorimetric profile. Our
study is the first to show a strong correlation between the initial step of Ebola virus infection and cholesterol, thus providing
a rationale for Ebola virus proteins being co-localized with lipid-raft domains. In all, the results show how small fusion
peptide sequences have evolved to adopt highly specific and strong interactions with membrane domains. Such features
suggest these processes are excellent targets for therapeutic and vaccine approaches to viral diseases
Biodiesel compatibility with carbon steel and hdpe parts
8 p.: il., tab.Compatibility of the new environmentally-friendly alternative of diesel engine fuels, biodiesel, with storage
and engine part materials, is still an open issue. In this work, the interaction between three fuels (petroleum
diesel and two types of biodiesel — soybean and sunflower) and two materials (carbon steel and high density
polyethylene) used in storage and automotive tanks, is analyzed in detail. A wide set of characterization
techniques was used to evaluate the changes in both solid and fluid materials, as weight change
measurement, optical, scanning electron and atomic force (AFM) microscopies, Raman and FTIR spectroscopies,
and differential scanning calorimetry. The AFM technique allowed detecting surface roughness and
morphology changes in the metallic material following the trends in the weight losses. In the case of
polymeric material, weight gain by fluid absorption occurred, being detected by the spectroscopic
techniques. The biodiesel fuels underwent some ageing however this phenomenon did not affect the
interaction between the biodiesel fuels and the substrates. The petrodiesel, which did not age, caused more
significant degradation of the substrates
Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)
Low Doses of Simvastatin Therapy Ameliorate Cardiac Inflammatory Remodeling in Trypanosoma cruzi-Infected Dogs
Chagas cardiomyopathy remodeling is based on the presence of Trypanosoma cruzi in heart tissue and on the complex inflammatory response leading to a myocardium fibrosis and alterations in conductive and functional heart parameters. This study aims to evaluate Simvastatin on the inflammatory response and heart functionality using dogs infected with Y strain of T. cruzi. Animals were treated daily with Simvastatin (20 mg) for 6 months and submitted to clinical and immunopathological evaluations. Simvastatin reduced heart expression and serum levels of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) but not interleukin-10 (IL-10), possibly favoring blood parasitism but reducing inflammation and fibrosis in the left ventricle and right atrium. Simvastatin also ameliorated ejection fraction, diastolic diameter, and mass index of the left ventricle 6 months after infection. This study suggests that more investigation should be performed on the use of statins as a prophylactic therapy against cardiac remodeling because of their effects on modifying immune response and benefiting functional parameters in dogs with T. cruzi-induced ventricular dysfunctions
O treinamento de merendeiras: análise do material instrucional do Instituto de Nutrição Annes Dias - Rio de Janeiro (1956-94)
O Protagonismo Infantojuvenil nos Processos Educomunicativos
Neste volume “O protagonismo infantojuvenil nos processos educomunicativos”, reunimos 53 artigos que transitam sobre a temática do protagonismo infantojuvenil em diversas experiências e processos educomunicativos e para facilitar sua leitura e busca por temas de seu interesse, eles estão organizados em 8 capítulos que abordam a educomunicação a partir do fazer das crianças e da apropriação da produção midiática. Expressão artística, rádio, vídeo, jornalismo, cultura digital, redes sociais entre outros são os temas abordados pelos autores destes trabalhos. convidamos o leitor a mergulhar nesta jornada educomunicativa, vivendo e revivendo junto conosco essas experiências vividas por outros, refletindo em cada texto sobre como estamos, como evoluímos e como seguimos os passos daqueles que com sua ousadia, amor e luta elaboraram os fundamentos da educomunicação