Elias C.N.,Military Institute of Engineering of Rio de Janeiro |
Gravina P.A.,Military Institute of Engineering of Rio de Janeiro |
Silva Filho C.E.,Cidade Universitaria
International Journal of Biomaterials | Year: 2012
Statement of Problem. The chemical or topographic modification of the dental implant surface can affect bone healing, promote accelerated osteogenesis, and increase bone-implant contact and bonding strength. Objective. In this work, the effects of dental implant surface treatment and fibronectin adsorption on the adhesion of osteoblasts were analyzed. Materials and Methods. Two titanium dental implants (Porous-acid etching and PorousNano-acid etching followed by fluoride ion modification) were characterized by high-resolution scanning electron microscopy, atomic force microscopy, and X-ray diffraction before and after the incorporation of human plasma fibronectin (FN). The objective was to investigate the biofunctionalization of these surfaces and examine their effects on the interaction with osteoblastic cells. Results. The evaluation techniques used showed that the Porous and PorousNano implants have similar microstructural characteristics. Spectrophotometry demonstrated similar levels of fibronectin adsorption on both surfaces (80). The association indexes of osteoblastic cells in FN-treated samples were significantly higher than those in samples without FN. The radioactivity values associated with the same samples, expressed as counts per minute (cpm), suggested that FN incorporation is an important determinant of the in vitro cytocompatibility of the surfaces. Conclusion. The preparation of bioactive titanium surfaces via fluoride and FN retention proved to be a useful treatment to optimize and to accelerate the osseointegration process for dental implants. © 2012 Carlos Nelson Elias et al.
Elsztein C.,Cidade Universitaria |
de Lucena R.M.,Cidade Universitaria |
de Morais Jr M.A.,Cidade Universitaria |
de Morais Jr M.A.,Federal University of Pernambuco
BMC Molecular Biology | Year: 2011
Background: Polyhexamethylene biguanide (PHMB) is an antiseptic polymer that is mainly used for cleaning hospitals and pools and combating Acantamoeba infection. Its fungicide activity was recently shown by its lethal effect on yeasts that contaminate the industrial ethanol process, and on the PE-2 strain of Saccharomyces cerevisiae, one of the main fermenting yeasts in Brazil. This pointed to the need to know the molecular mechanism that lay behind the cell resistance to this compound. In this study, we examined the factors involved in PHMB-cell interaction and the mechanisms that respond to the damage caused by this interaction. To achieve this, two research strategies were employed: the expression of some genes by RT-qPCR and the analysis of mutant strains.Results: Cell Wall integrity (CWI) genes were induced in the PHMB-resistant Saccharomyces cerevisiae strain JP-1, although they are poorly expressed in the PHMB-sensitive Saccharomyces cerevisiae PE2 strain. This suggested that PHMB damages the glucan structure on the yeast cell wall. It was also confirmed by the observed sensitivity of the yeast deletion strains, Δslg1, Δrom2, Δmkk2, Δslt2, Δknr4, Δswi4 and Δswi4, which showed that the protein kinase C (PKC) regulatory mechanism is involved in the response and resistance to PHMB. The sensitivity of the Δhog1 mutant was also observed. Furthermore, the cytotoxicity assay and gene expression analysis showed that the part played by YAP1 and CTT1 genes in cell resistance to PHMB is unrelated to oxidative stress response. Thus, we suggested that Yap1p can play a role in cell wall maintenance by controlling the expression of the CWI genes.Conclusion: The PHMB treatment of the yeast cells activates the PKC1/Slt2 (CWI) pathway. In addition, it is suggested that HOG1 and YAP1 can play a role in the regulation of CWI genes. © 2011 Elsztein et al; licensee BioMed Central Ltd.
De Albuquerque L.S.C.,Federal University of Pernambuco |
De Souza T.B.,Federal University of Pernambuco |
Maia A.C.D.,Cidade Universitaria |
Iannuzzi L.,Federal University of Pernambuco
Journal of Insect Science | Year: 2014
In order to obtain information on the biology of the masked chafer, Cyclocephala paraguayensis Arrow (Scarabaeidae: Dynastinae: Cyclocephalini), and its immature morphology, the beetle life cycle was studied under laboratory conditions. After field collection, adults were placed inside containers filled with soil obtained in the original capture to provide an oviposition site after mating ocurred. Eggs were collected daily and isolated for manipulation experiments and life cycle observations. Detailed information about the eggs, instars and life cycle duration, and morphological features of immature stages were noted and examined. Egg viability was higher in the "nonmanipulated" batch. The complete ontogenic cycle of C. paraguayensis was 171 ± 11 days (n = 7). Despite the records of Cyclocephala being crop pests, reared larvae of C. paraguayensis thrived and developed into well-formed, fertile adults on an entirely saprophagous diet, indicating that they are not rhizophagous in the wild. The third instar can be distinguished from the other species mainly by the following unique characters: maximum width of the head capsule, distal antennal setae, and bifurcated setae on the raster. © 2014, Library of the University of Arizona. All rights reserved.
Soares Luis H.P.,Cidade Universitaria |
Soares Luis H.P.,University of Lisbon |
Assuncao V.A.,Polytechnic Institute of Portalegre |
Soares Luis L.F.,Polytechnic Institute of Portalegre
International Journal of Adolescent Medicine and Health | Year: 2016
Purpose: Oral health has a profound impact on the health of adolescents. The aim of the present study was to obtain information on habits, knowledge and oral hygiene attitudes of Portuguese teenagers and to study the gender differences concerning these issues. Methods: A total of 1203 adolescents participated in the study (55.8% females; mean age, 14.9 years). To recruit participants, a national network of community dental hygienists, working in the health centers, was created, and adolescents were contacted at the schools. A questionnaire was applied in the classroom, during school hours, under supervision of one researcher and the classroom teacher, after collection of informed consent forms. Results: Portuguese adolescents do not seem to have dental fear but have some anxiety when at the dental office; girls are more anxious than boys. Girls are also more concerned with esthetics and aware of dental problems and care about oral health of family and friends. Parental supervision is more relevant for boys in order to obtain better compliance with dental care; however, 97.2% of the adolescents do not consider maintaining teeth throughout the lifetime as relevant. Conclusion: Teenagers recognize dental professionals as educators and oral health as relevant in their lives. It is possible to assume that gender has an influence on adolescent's habits, behavior and attitudes regarding oral hygiene. There is a difference between boys and girls concerning their habits, knowledge and attitudes in dental hygiene; this difference may show the need to create different strategies for oral health promotion for these two groups of adolescents. © 2016 by De Gruyter.
Salles L.,Cidade Universitaria |
Balbo J.T.,University of Sao Paulo |
da Silva Pereira D.,Federal University of Santa Maria
International Journal of Pavement Research and Technology | Year: 2015
As a proposed long-term pavement solution for bus stops and corridors in highly urbanized areas, four experimental continuously reinforced concrete pavement (CRCP) sections with different percentages of longitudinal steel were built in São Paulo, Brazil. The pavement sections are only 50 meters long each, a short construction length in comparison to traditional CRCP, which is normally built as long as the construction process allows. A four-year cracking survey of the experimental sections showed that the shorter section length, perhaps due in part to the lack of anchorage, results in a cracking pattern unlike that of the CRCP with traditional lengths. Additionally, two non-destructive tests were carried out to evaluate the structural performance of the experimental sections. First, deflection tests using a falling weight deflectometer (FWD) were conducted to measure the load transfer efficiency (LTE) across all cracks and to determinate slab parameters by back calculation. Second, dynamic load tests to obtain the concrete stresses under a known load. The results show that the LTE values are adequate (above 90%) in all sections, despite its distinct crack pattern and that tensile stresses at the bottom of the slab are within critical strength values for the concrete. The results from this experimental study are discussed in light of the current literature for CRCP design and performance. © Chinese Society of Pavement Engineering.
Mendes F.L.,Cidade Universitaria |
Pinho A.R.,Cidade Universitaria |
Figueiredo M.A.G.,State University of Rio de Janeiro
Defect and Diffusion Forum | Year: 2013
The pyrolysis of biomass is a thermal process that converts, at high yield, solid biomass into a liquid product known as bio-oil. One alternative for the production of a bio-oil of better quality and with lower oxygen content is the use of catalysts in the pyrolysis reactor, rather than an inert, a process called catalytic pyrolysis. The objective of this study was to investigate the effects on product yields and the qualities of products of two different catalysts, one acidic, a commercial fluid catalytic cracking (FCC) catalyst, and a basic one containing hydrotalcite. Inert material, a type of silica, was used as reference. The tests were conducted in a pilot plant with a circulating fluidized bed reactor, specially adapted to perform the catalytic pyrolysis tests, at temperatures of 450°C and 550°C. The results showed that the increase in the residence time of the pyrolysis vapors had a significant impact on products yields, when compared with the profile found in the literature for fast pyrolysis. The FCC catalyst presented higher deoxygenation rates by dehydration, while the hydrotalcite showed greater capacity for decarboxylation. Thus, the use of either the FCC catalyst or hydrotalcite are not suitable for intermediate pyrolysis reactors, generating a product with high water content and low content of organic compounds in bio-oil and produce more coke. None of the materials tested produced bio-oils with considerable hydrocarbons yields and presented high amounts of phenolic compounds. In general, silica had the best results in terms of yield and quality of bio-oil. © (2013) Trans Tech Publications, Switzerland.
Magalhaes T.,Cidade Universitaria
Parasites and Vectors | Year: 2014
The aim of this Letter is to call attention to the presence of iron-containing or heme aggregates seen within or near the peritrophic matrix (PM) in published Anopheles gambiae and Aedes aegypti midgut micrographs. The micrographs shown here suggest that the PM of An. gambiae adult female is not a homogenous layer and instead may have a peritrophin layer surrounded by heme aggregates that are possibly associated to other molecules involved in their formation. In depth studies addressing PM structure in different mosquito species are needed, as these will be important to continue clarifying the roles of the PM. © 2014 Magalhaes; licensee BioMed Central Ltd.
Choi Y.-S.,Ohio University |
Farelas F.,Ohio University |
Nesic S.,Ohio University |
Magalhaes A.A.O.,Cidade Universitaria |
De Azevedo Andrade C.,Cidade Universitaria
Corrosion | Year: 2014
The objective of the present study was to evaluate the corrosion properties of carbon steel in supercritical carbon dioxide (CO2)/brine mixtures related to the deep water oil production development. Corrosion tests were performed in 25 wt% sodium chloride (NaCl) solution under different CO 2 partial pressures (4, 8, 12 MPa) and temperatures (65°C, 90°C). Corrosion behavior of carbon steel was evaluated using electrochemical methods (linear polarization resistance [LPR] and electrochemical impedance spectroscopy [EIS]), weight-loss measurements, and surface analytical techniques (scanning electron microscopy [SEM], energy-dispersive x-ray spectroscopy [EDS], x-ray diffraction [XRD], and infinite focus microscopy [IFM]). The corrosion rates measured at 65°C showed a high corrosion rate (~10 mm/y) and a slight difference with pressure. Under these conditions, the sample surface was locally covered by iron carbide (Fe3C), which is porous and non-protective. However, the corrosion rates measured at 90°C increased with time at the initial period of the test and decreased to a very low value (~0.05 mm/y) due to the formation of protective iron carbonate (FeCO3) layer regardless the CO2 partial pressure. © 2014, NACE International.
Pinheiro V.G.,Cidade Universitaria |
Goldman A.,Cidade Universitaria |
Kon F.,Cidade Universitaria
Concurrency Computation Practice and Experience | Year: 2011
The mobile agent paradigm has emerged as a promising alternative to overcome the construction challenges of opportunistic grid environments. This model can be used to implement mechanisms that enable application execution progress even in the presence of failures such as the mechanisms provided by the MAG middleware (Mobile Agents for Grids). MAG includes retrying, replication, and checkpointing as fault tolerance techniques; they operate independently from each other and they are not capable of detecting changes on resource availability. In this paper, we describe a MAG extension that is capable of migrating agents when nodes fail, which optimizes application progress by keeping only the most advanced checkpoint, and also migrates slow replicas. The proposed approach was evaluated via simulations and experiments, which showed significant improvements. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd.
Uemoto L.,UFF |
Nascimento De Azevedo R.,Avenida Pastor Martin Luther King Jr |
Almeida Alfaya T.,UFF |
Nunes Jardim Reis R.,UNIVERSO |
And 2 more authors.
Current Pain and Headache Reports | Year: 2013
The aim of the present review is to discuss two forms of treatment for myofascial pain: laser therapy and dry needling. Although studies have reported the deactivation of myofascial trigger points with these two methods, clinical trials demonstrating their efficacy are scarce. The literature reports greater efficacy with the use of laser over dry needling. It has been suggested that improvements in microcirculation through the administration of laser therapy may favor the supply of oxygen to the cells under conditions of hypoxia and help remove the waste products of cell metabolism, thereby breaking the vicious cycle of pain, muscle spasm and further pain. While laser therapy is the method of choice for patients with a fear of needles and healthcare professionals inexperienced with the dry needling technique, further controlled studies are still needed to prove the greater efficacy of this method. © 2013 Springer Science+Business Media New York.