RESUMO
Chitosan-based magnetite nanocomposites were synthesized using a versatile ultrasound assisted in situ method involving one quick step. This synthetic route approach results in the formation of spheroidal nanoparticles (Fe3O4) with average diameter between 10 and 24nm, which were found to be superparamagnetic with saturation magnetization (Ms) ranges from 32-57emug(-1), depending on the concentration. The incorporation of Fe3O4 into chitosan matrix was also confirmed by FTIR and TG techniques. This hybrid nanocomposite has the potential application as electrochemical sensors, since the electrochemical signal was excepitionally stable. In addition, the in situ strategy proposed in this work allowed us to synthesize the nanocomposite system in a short time, around 2min of time-consuming, showing great potential to replace convencional methods. Herein, the procedure will permit a further diversity of applications into nanocomposite materials engineering.
Assuntos
Quitosana/química , Eletroquímica/instrumentação , Nanopartículas de Magnetita/química , Nanocompostos/química , Nanotecnologia/métodos , Ondas Ultrassônicas , Técnicas de Química Sintética , Eletrodos , Cinética , Tamanho da PartículaRESUMO
OBJECTIVE: This study examined the joint influence of work- and household-related variables on smoking behavior among a population representative sample of blue-collar workers with live-in partners. METHODS: The study used data on 1389 blue-collar workers from the Tobacco Use Supplement to the United States Current Population Survey 2002 to 2003 longitudinal overlap sample. Unadjusted and adjusted logistical regression analyses, which employed sampling and replicate weights to account for sampling design, were run to estimate independent and joint effects of the predictors. RESULTS: In adjusted analyses, partner smoking (OR=4.97, 95%CI=3.02-8.18) and complete and partial home smoking policy (OR=0.16, 95%CI=0.09-0.29 and OR=0.39, 95%CI=0.23-0.68, respectively) were significant predictors of smoking status, but worksite smoking policies and presence of a young child under 5 in the household were not (p>0.05). Baseline complete home smoking ban was a significant predictor of subsequent cessation (OR=3.49, 95%CI=1.19-10.23), while partner smoking status, workplace smoking policy, and the presence of a young child in the home did not predict cessation (p>0.05). CONCLUSION: Household-related variables were significant predictors of smoking status and cessation among blue-collar workers. Current efforts to decrease smoking in this group, which are mostly focused on work-related risk factors, should consider how to incorporate household risk factors.
Assuntos
Abandono do Hábito de Fumar/psicologia , Fumar/epidemiologia , Local de Trabalho/legislação & jurisprudência , Adulto , Emprego , Feminino , Inquéritos Epidemiológicos , Humanos , Relações Interpessoais , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Características de Residência , Abandono do Hábito de Fumar/estatística & dados numéricos , Estados UnidosRESUMO
Current knowledge of the pathogenic hantavirus indicates that wild rodents are its primary natural reservoir. Specific primers to detect the presence of viral genomes were developed using an SYBR-Green-based real-time RT-PCR protocol. One hundred sixty-four rodents native to the Atlantic Forest biome were captured in São Paulo State, Brazil, and their tissues were tested. The presence of hantavirus RNA was detected in sixteen rodents: three specimens of Akodon montensis, three of Akodon cursor, two of Necromys lasiurus, one of Juliomys sp., one of Thaptomys nigrita, five of Oligoryzomys nigripes, and one of Oryzomys sp. This SYBR Green real-time RT-PCR method for detection of hantavirus may be useful for surveying hantaviruses in Brazil.