285 research outputs found
Growth model with restricted surface relaxation
We simulate a growth model with restricted surface relaxation process in d=1
and d=2, where d is the dimensionality of a flat substrate. In this model, each
particle can relax on the surface to a local minimum, as the Edwards-Wilkinson
linear model, but only within a distance s. If the local minimum is out from
this distance, the particle evaporates through a refuse mechanism similar to
the Kim-Kosterlitz nonlinear model. In d=1, the growth exponent beta, measured
from the temporal behavior of roughness, indicates that in the coarse-grained
limit, the linear term of the Kardar-Parisi-Zhang equation dominates in short
times (low-roughness) and, in asymptotic times, the nonlinear term prevails.
The crossover between linear and nonlinear behaviors occurs in a characteristic
time t_c which only depends on the magnitude of the parameter s, related to the
nonlinear term. In d=2, we find indications of a similar crossover, that is,
logarithmic temporal behavior of roughness in short times and power law
behavior in asymptotic times
Risk of chronic arthralgia and impact of pain on daily activities in a cohort of patients with chikungunya virus infection from Brazil
Objectives: To investigate risk factors for persistent arthralgia in patients with chikungunya, and describe its impact on daily activities. Methods: From September 2014 to July 2016, a surveillance study enrolled patients with acute febrile illness in Salvador, Brazil, and detected those with chikungunya virus infection using IgM enzyme-linked immunosorbent assay or reverse transcriptase polymerase chain reaction. Telephone follow-ups were performed to ascertain the progression of disease. Results: Of 153 followed cases, 65 (42.5%) reported chronic arthralgia that lasted >3 months, and 47 (30.7%) were still symptomatic at the time of the interview (approximately 1.5 years after symptom onset). Limitations in daily activities and mental distress were reported by 93.8% and 61.5% of those with chronic arthralgia, respectively. Female sex [risk ratio (RR) 1.79, 95% confidence interval (CI) 1.95–2.69] and age (RR 1.02 for each 1-year increase, 95% CI 1.01–1.03) were independent risk factors for chronic arthralgia. Chronic arthralgia was not associated with co-infection with dengue virus (RR 0.97, 95% CI 0.48–1.94) or chikungunya viral load at diagnosis (median chikungunya virus RNA of 5.60 and 5.52 log10 copies/μL for those with and without chronic arthralgia, respectively; P = 0.75). Conclusions: These findings reinforce the high frequency of chronic chikungunya arthralgia, and highlight the substantial disability associated with the persistence of pain. Development of novel strategies to mitigate the transmission of chikungunya virus and to provide long-term medical assistance for patients with chikungunya are needed urgently.Fil: Silva, Monaíse M. O.. Fundación Oswaldo Cruz; BrasilFil: Kikuti, Mariana. Universidade Federal da Bahia; Brasil. Fundación Oswaldo Cruz; BrasilFil: Anjos, Rosângela O.. Fundación Oswaldo Cruz; BrasilFil: Portilho, Moyra M.. Fundación Oswaldo Cruz; BrasilFil: Santos, Viviane C.. Fundación Oswaldo Cruz; BrasilFil: Gonçalves, Thaiza S.F.. Fundación Oswaldo Cruz; BrasilFil: Tauro, Laura Beatriz. Fundación Oswaldo Cruz; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Moreira, Patrícia S. S.. Fundación Oswaldo Cruz; BrasilFil: Jacob Nascimento, Leile C.. Fundación Oswaldo Cruz; BrasilFil: Santana, Perla M.. Fundación Oswaldo Cruz; BrasilFil: Campos, Gúbio S.. Universidade Federal da Bahia; BrasilFil: Siqueira, André M.. Fundación Oswaldo Cruz; BrasilFil: Kitron, Uriel D.. University of Emory; Estados Unidos. Fundación Oswaldo Cruz; BrasilFil: Reis, Mitermayer G.. University of Yale; Estados Unidos. Fundación Oswaldo Cruz; Brasil. Universidade Federal da Bahia; BrasilFil: Ribeiro, Guilherme S.. Fundación Oswaldo Cruz; Brasil. Universidade Federal da Bahia; Brasi
Human toxocariasis: contribution by Brazilian researchers
In the present paper the main aspects of the natural history of human infection by Toxocara larvae that occasionally result in the occurrence of visceral and/or ocular larva migrans syndrome were reviewed. The contribution by Brazilian researchers was emphasized, especially the staff of the Tropical Medicine Institute of São Paulo (IMT)
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