Effects of solvent volatilization time on the bond strength of etch-and-rinse adhesive to dentin using conventional or deproteinization bonding techniques

José Aginaldo de Sousa Júnior,Márcia Luciana Carregosa Santana,Fabricio Eneas Diniz de Figueiredo,André Luis Faria-e-Silva 대한치과보존학회 2015 Restorative Dentistry & Endodontics Vol.40 No.3

Objectives: This study determined the effect of the air-stream application time and the bonding technique on the dentin bond strength of adhesives with different solvents. Furthermore, the content and volatilization rate of the solvents contained in the adhesives were also evaluated. Materials and Methods:Three adhesive systems with different solvents (Stae, SDI, acetone; XP Bond, Dentsply De Trey, butanol; Ambar, FGM, ethanol) were evaluated. The concentrations and evaporation rates of each adhesive were measured using an analytical balance. After acid-etching and rinsing, medium occlusal dentin surfaces of human molars were kept moist (conventional) or were treated with 10% sodium hypochlorite for deproteinization. After applying adhesives over the dentin, slight air-stream was applied for 10, 30 or 60 sec. Composite cylinders were built up and submitted to shear testing. The data were submitted to ANOVA and Tukey’s test (α = 0.05). Results: Stae showed the highest solvent content and Ambar the lowest. Acetone presented the highest evaporation rate, followed by butanol. Shear bond strengths were significantly affected only by the factors of ‘adhesive’ and ‘bonding technique’ (p < 0.05), while the factor ‘duration of air-stream’ was not significant. Deproteinization of dentin increased the bond strength (p < 0.05). Stae showed the lowest bond strength values (p < 0.05), while no significant difference was observed between XP Bond and Ambar. Conclusions: Despite the differences in content and evaporation rate of the solvents, the duration of air-stream application did not affect the bond strength to dentin irrespective of the bonding technique.

Effects of Dietary Spirulina on Vascular Reactivity

M.A. Juárez-Oropeza,D. Mascher,P.V. Torres-Durán,J.M. Farias,M.C. Paredes-Carbajal 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.1

There are several reports suggesting that Spirulina (Arthrospira) may have a beneficial effect in the prevention of cardiovascular diseases. Here we review the results of studies on the effects of dietary Spirulina on the vasomotor reactivity of aortic rings excised from either lean or obese Wistar rats. We also review preliminary results on the effects of Spirulina intake on plasma lipids and blood pressure in humans. The results of the former studies strongly suggest that Spirulina induces a tone-related increase in the synthesis/release of nitric oxide by the endothelium as well as an increase in the synthesis/release of a vasodilating cyclooxygenase-dependent metabolite of arachidonic acid and/or a decrease in the synthesis/release of a vasoconstricting eicosanoid by the endothelium. In humans, Spirulina maxima intake decreases blood pressure and plasma lipid concentrations, especially triacylglycerols and low-density lipoprotein-cholesterol, and indirectly modifies the total cholesterol and high-density lipoprotein-cholesterol values.

Gas expulsion in highly substructured embedded star clusters

Farias, J P,Fellhauer, M,Smith, R,Domí,nguez, R,Dabringhausen, J Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.476 No.4

SPIF-A: on the development of a new concept of incremental forming machine

R.J. Alves de Sousa,J.A.F. Ferreira,J.B. Sá de Farias,J.N.D. Torrão,D.G. Afonso,M.A.B.E Martins 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5

This paper presents the design and project of an innovative concept for a Single PointIncremental Forming (SPIF) Machine. Nowadays, equipment currently available for conducting SPIF resultmostly from the adaptation of conventional CNC machine tools that results in a limited range of applicationsin terms of materials and geometries. There is also a limited market supply of equipment dedicated toIncremental Sheet Forming (ISF), that are costly considering low batches, making it unattractive forindustry. Other factors impairing a quicker spread of SPIF are large forming times and poor geometricalaccuracy of parts. The following sections will depict the development of a new equipment, designed toovercome some of the limitations of machines currently used, allowing the development of a sounding basisfor further studies on the particular features of this process. The equipment here described possesses sixdegrees-of freedom for the tool, for the sake of improved flexibility in terms of achievable tool-paths and anextra stiffness provided by a parallel kinematics scheme. A brief state of the art about the existing SPIFmachines is provided to support the project’s guidelines.

Antimicrobial Activity of Benzophenones and Extracts from the Fruits of Garcinia brasiliensis

F.J. Naldoni,A.L.R. Claudino,J.W. Cruz Jr.,J.K. Chavasco,P.M. Faria e Silva,M.P. Veloso,M.H. Dos Santos 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.2

The pericarp and seeds from fruits of Garcinia brasiliensis were subjected to extraction with hexane and ethanol. The pericarp hexane extract (PHE) and seed ethanol extract (SEE) were purified by silica gel column chromatography, which permitted isolation of the prenylated benzophenones 7-epiclusianone (1) and guttiferone-A (2), respectively. The antimicrobial activity of PHE, SEE, and compounds 1 and 2 were evaluated against Candida albicans, Staphylococcus aureus, Escherichia coli, and Bacillus cereus cultures. The minimum inhibitory concentration and minimum bactericidal concentration were established. The substances presented activity against S. aureus and B. cereus as follows: PHE, 4.0 μg/mL and 2.4 μg/mL; SEE, 10.0 μg/mL and 12.6 μg/mL; 7-epiclusianone, 1.2 μg/mL and 0.6 μg/mL; and guttiferone-A, 2.4 μg/mL and 2.4 μg/mL, respectively. The direct relationship between the lipophilic character of the structure and activity in Gram-positive bacteria was specifically observed. Therefore these extracts and prenylated benzophenones represent an interesting topic for further studies and open possibilities for an alternative control of diseases associated with Gram-positive bacteria.

Evaluation of nuclear ribosomal RNA and chloroplast gene markers for the DNA taxonomy of centric diatoms

Lee, M.A.,Faria, D.G.,Han, M.S.,Lee, J.,Ki, J.S. Pergamon Press ; Elsevier Science Ltd 2013 Biochemical systematics and ecology Vol.50 No.-

Diatoms are highly diversified microeukaryotes with a taxonomy that has been under perpetual revision, particularly by means of molecular analyses. In this study, we evaluated typical genes to find the best molecular marker for the DNA taxonomy of centric diatoms, including Chaetoceros Ehrenberg, Cyclotella Kutzing ex de Brebisson, Discostella Houk & Klee, Stephanodiscus Ehrenberg, and Thalassiosira Cleve. Our test genes included nuclear ribosomal RNA (e.g. small subunit, 5.8S, and large subunit [LSU]), and chloroplast genes (e.g. ribulose-1, 5-biphoshate carboxylase oxygenase and D1 protein of the photosystem II reaction centre core complex [psbA]). Calculated genetic divergence was highest for LSU ribosomal RNA D1-D5 (p-distance of 12.3), followed by 5.8S (7.7), ribulose-1, 5-biphoshate carboxylase oxygenase (7.4), small subunit (6.6), and psbA (3.7). The phylogenetic trees for individual genes effectively separated taxonomically tested centric diatoms with different phylogenetic resolutions; however, psbA was incongruent with others. These taxonomic resolving powers were in agreement with genetic divergences. Parsimony analysis showed that LSU evolved 1.97 times more rapidly than psbA and 1.07 times more rapidly than 5.8S. These results suggest that all of the tested genes except psbA can be used as taxonomic markers for centric diatoms and that LSU is the best molecular marker.

High-performance circular sawing of AISI 1045 steel with cermet and tungsten carbide inserts

A. M. Abrão,M. C. Moreira,P. E. Faria,J. C. Campos Rubio 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

This work investigated the influence of cutting speed and feed rate on cutting forces, surface roughness, and slot width circular sawingof AISI 1045 steel. The effects of tool material (cermet and tungsten carbide) and geometry (chip breaker flute and pre-cutting/postcuttingteeth) were also investigated. Thrust and radial forces generally tended to decrease as the cutting speed increased and tended toincrease with the feed rate. The lowest values of thrust and radial forces were obtained using a tungsten carbide saw ground with precuttingand post-cutting teeth. With regard to the quality of the machined wall, the lowest surface roughness was obtained by applying thehighest cutting speed and lowest feed rate and employing a cermet brazed saw. Under this condition, roughness values comparable toface turning and parting off operations were obtained. The cermet brazed saw was responsible for producing the narrowest slot widths.

Antimicrobial Activity of Benzophenones and Extracts from the Fruits of Garcinia brasiliensis

Naldoni, F.J.,Claudino, A.L.R.,Cruz, J.W. Jr,Chavasco, J.K.,Silva, P.M. Faria e,Veloso, M.P.,Santos, M.H. Dos The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.2

The pericarp and seeds from fruits of Garcinia brasiliensis were subjected to extraction with hexane and ethanol. The pericarp hexane extract (PHE) and seed ethanol extract (SEE) were purified by silica gel column chromatography, which permitted isolation of the prenylated benzophenones 7-epiclusianone (1) and guttiferone-A (2), respectively. The antimicrobial activity of PHE, SEE, and compounds 1 and 2 were evaluated against Candida albicans, Staphylococcus aureus, Escherichia coli, and Bacillus cereus cultures. The minimum inhibitory concentration and minimum bactericidal concentration were established. The substances presented activity against S. aureus and B. cereus as follows: PHE, $4.0\;{\mu}g/mL$ and $2.4\;{\mu}g/mL$; SEE, $10.0\;{\mu}g/mL$ and $12.6\;{\mu}g/mL$; 7-epiclusianone, $1.2\;{\mu}g/mL$ and $0.6\;{\mu}g/mL$; and guttiferone-A, $2.4\;{\mu}g/mL$ and $2.4\;{\mu}g/mL$, respectively. The direct relationship between the lipophilic character of the structure and activity in Gram-positive bacteria was specifically observed. Therefore these extracts and prenylated benzophenones represent an interesting topic for further studies and open possibilities for an alternative control of diseases associated with Gram-positive bacteria.

A molecular survey of freshwater microeukaryotes in an Arctic reservoir (Svalbard, 79°N) in summer by using next-generation sequencing

Boopathi, T.,Faria, D. G.,Lee, M. D.,Lee, J.,Chang, M.,Ki, J. S. Springer Science + Business Media 2015 Polar biology Vol.38 No.2

<P>The molecular diversity of freshwater microeukaryotes, particularly phytoplankton, in the Arctic Svalbard, has been relatively unexplored. Freshwater algae are considered biological indicators of environmental change and can be useful in assessing the impact of global climate change and increased environmental pollution. In this study, freshwater microeukaryotes in an Arctic reservoir at Ny-C(0)lesund (Svalbard, Norway) were studied using the hypervariable V1-V3 small subunit rRNA and 454 pyrosequencing. On the basis of 8,956 reads, we revealed high genetic diversity in eukaryotes, representing all known eukaryotic supergroups, except Excavata. 'Chromalveolata' (previously supergroup Chromalveolata) and Archaeplastida were the most and least abundant supergroups, respectively. After data mining, 57 phylotypes were detected from 7,398 pyrosequences. They were dominated by stramenopiles (84 %) and Dinoflagellata (13 %), with minor contributions from Cryptophyta, Chlorophyta, and Telonemida. The detection of algae belonging to the orders Mamiellales and Monomastigales provides a window into a fraction of the 'rare biosphere' that had previously been undetected in such environments. Interestingly, no haptophytes were recorded. Stramenopiles and Dinoflagellata mainly comprised taxa belonging to the families Chrysophyceae, Synurophyceae, and Dinophyceae. On the basis of the proportion of operational taxonomic units, the dominant phylotypes were found to include Ochromonas spp., Mallomonas spp., and Uroglena americana. These results demonstrate the significance of a chrysophyte-dominated microeukaryotic community, which is of great potential for future studies in terms of reconstruction of past climate trends and monitoring of environmental change in the Arctic.</P>

Effects of Dietary Spirulina on Vascular Reactivity

Juarez-Oropeza, M.A.,Mascher, D.,Torres-Duran, P.V.,Farias, J.M.,Paredes-Carbajal, M.C. The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.1

There are several reports suggesting that Spirulina (Arthrospira) may have a beneficial effect in the prevention of cardiovascular diseases. Here we review the results of studies on the effects of dietary Spirulina on the vasomotor reactivity of aortic rings excised from either lean or obese Wistar rats. We also review preliminary results on the effects of Spirulina intake on plasma lipids and blood pressure in humans. The results of the former studies strongly suggest that Spirulina induces a tone-related increase in the synthesis/release of nitric oxide by the endothelium as well as an increase in the synthesis/release of a vasodilating cyclooxygenase-dependent metabolite of arachidonic acid and/or a decrease in the synthesis/release of a vasoconstricting eicosanoid by the endothelium. In humans, Spirulina maxima intake decreases blood pressure and plasma lipid concentrations, especially triacylglycerols and low-density lipoprotein-cholesterol, and indirectly modifies the total cholesterol and high-density lipoprotein-cholesterol values.