280 research outputs found
Effect Of Salivary Contamination At Different Steps Of The Bonding Process On The Microleakage Around Class V Restorations
This study aimed to investigate the influence of the moment of salivary contamination during the bonding procedure (before or after acid conditioning) on the microleakage around composite resin restorations. Sixty bovine incisors received two Class V preparations (one with dentin margins and other with enamel margins). Teeth were randomly assigned into three, groups (n-20): 1) control (not contaminated); 2) salivary contamination before etching with 34% phosphoric acid; and, 3) salivary contamination after acid etching. Cavities were restored using Prime & Bond NT (Dentsply) adhesive system and TPH Spectrum (Dentsply) composite according to manufacturer instructions. Teeth were thermocycled (500x, 5-55°C, 60s/bath), immersed in 2% methylenee blue buffered solution (pH 7.0), and sectioned into two halves. Three examiners measured the extent of dye penetration or dentin and enamel margins in a stereoscope microscope, using four representative scores. Statistical analysis were performed with Kruskal-Wallis/Wilcoxon tests (α-5%). The results showed that enamel and dentin margins did not present significant differences (p>0.05). However, significantly higher dye penetration was observed on substrates etched and further contaminated with saliva. It was concluded that salivary contamination after acid etching increases the microleakage around composite resin restorations, especially at dentin margins. However, acid etching subsequent to the contamination can avoid negative effects on restorations margins.62314451449Van Meerbeek, B., Van Landuyt, K., De Munck, J., Hashimoto, M., Peumans, M., Lambrechts, P., Technique -sensitivity of contemporary adhesives (2005) Dent Mater J, 24, pp. 1-13Civelek, A., Ersoy, M., L'Hotelier, E., Soyman, M., Say, E.C., Polymerization shrinkage and microleakage in Class II cavities of various resin composites (2003) Oper Dent, 28, pp. 635-641Besnault, C., Attal, J.P., Influence of a simulated oral environment on microleakage of two adhesive systems in Class II composite restorations (2002) J Dent, 30, pp. 1-6Spencer, P., Wang, Y., Bohaty, B., Interfacial chemistry of moisture-aged class II composite restorations (2006) J Biomed Mater Res B Appl Biomater, 77, pp. 234-240Direct and indirect restorative materials (2003) J Am Dent Assoc, 134, pp. 463-472. , Council on Scientific Affairs ADASoldani, F., Foley, J., An assessment of rubber dam usage amongst specialists in paediatric dentistry practising within the UK (2007) Int J Paediatr Dent, 17, pp. 50-56Fernandes, A.S., Rodrigues, S., Singhal, K., Murthi, M.S., Assessment of chair side techniques for composite resin restoration - a survey (2003) Indian J Dent Res, 14, pp. 47-56Taskonak, B., Sertgoz, A., Shear bond strengths of saliva contaminated 'one-bottle' adhesives (2002) J Oral Rehabil, 29, pp. 559-564Eiriksson, S.O., Pereira, P.N., Swift Jr., E.J., Heymann, H.O., Sigurdsson, A., Effects of saliva contamination on resin-resin bond strength (2004) Dent Mater, 20, pp. 37-44Hiraishi, N., Kitasako, Y., Nikaido, T., Nomura, S., Burrow, M.F., Tagami, J., Effect of artificial saliva contamination on pH value change and dentin bond strength (2003) Dent Mater, 19, pp. 429-434Park, J.W., Lee, K.C., The influence of salivary contamination on shear bond strength of dentin adhesive systems (2004) Oper Dent, 29, pp. 437-442Yoo, H.M., Oh, T.S., Pereira, P.N., Effect of saliva contamination on the microshear bond strength of one-step self-etching adhesive systems to dentin (2006) Oper Dent, 31, pp. 127-134Hitmi, L., Attal, J.P., Degrange, M., Influence of the time-point of salivary contamination on dentin shear bond strength of 3 dentin adhesive systems (1999) J Adhes Dent, 1, pp. 219-232Reis, A.F., Giannini, M., Kavaguchi, A., Soares, C.J., Line, S.R., Comparison of microtensile bond strength to enamel and dentin of human, bovine, and porcine teeth (2004) J Adhes Dent, 6, pp. 117-121Eiriksson, S.O., Pereira, P.N., Swift, E.J., Heymann, H.O., Sigurdsson, A., Effects of blood contamination on resin-resin bond strength (2004) Dent Mater, 20, pp. 184-190Toledano, M., Osorio, R., Ceballos, L., Fuentes, M.V., Fernandes, C.A., Tay, F.R., Microtensile bond strength of several adhesive systems to different dentin depths (2003) Am J Dent, 16, pp. 292-29
Phase transition and critical behaviour of the d=3 Gross-Neveu model
A second order phase transition for the three dimensional Gross-Neveu model
is established for one fermion species N=1. This transition breaks a paritylike
discrete symmetry. It constitutes its peculiar universality class with critical
exponent \nu = 0.63 and scalar and fermionic anomalous dimension \eta_\sigma =
0.31 and \eta_\psi = 0.11, respectively. We also compute critical exponents for
other N. Our results are based on exact renormalization group equations.Comment: 4 pages, 1 figure; v4 corresponds to the published articl
ANĂLISE DA CURVA DE CRESCIMENTO DA CIRCUNFERĂNCIA ESCROTAL DE TOUROS DA RAĂA CANCHIM E DO GRUPO GENĂTICO MA
O objetivo deste trabalho foi ajustar diferentes curvas de crescimento para circunferĂȘncia
escrotal (CE) em função da idade, em touros da raça Canchim e do grupo genético MA mediante a
utilização de modelos nĂŁo lineares. Na anĂĄlise foram empregadas 27.363 medidas da circunferĂȘncia
escrotal, provenientes de 5.520 touros da Raça Canchim e, 8.892 medidas de circunferĂȘncia escrotal
oriundas de 1.450 touros do grupo genético MA. Os resultados obtidos demonstram que o modelo
Gompertz foi o que melhor descreveu o crescimento da CE nos touros da raça Canchim e o LogĂstico
foi o mais adequado para descrever o crescimento da CE no grupo genético MA. O modelo Brody
apresentou pouca utilidade no ajustamento da CE em função da idade.
Growth curves of Scrotal circunference in Canchim and MA bulls
Abstract
The objective of this study was to adjust different growth curves of scrotal circumference
(SC) by age. The data consisted of records on Canchim bulls and bulls of the MA genetic group wich
were fit by no linear models. Were considered 27.363 measures on 5.520 Canchim bulls and 8.892
measures on 1.450 bulls of the MA genetic group. The results showed that the Gompertz model was
the best to describe the growth of SC in the Canchim bulls and the Logistic model was the most
appropriate to describe the growth of SC in the MA genetic group. The Brody model presented little
usefulness in the adjustment of SC by age
Trajectory versus probability density entropy
We study the problem of entropy increase of the Bernoulli-shift map without
recourse to the concept of trajectory and we discuss whether, and under which
conditions if it does, the distribution density entropy coincides with the
Kolmogorov-Sinai entropy, namely, with the trajectory entropy.Comment: 24 page
Launch of the Space experiment PAMELA
PAMELA is a satellite borne experiment designed to study with great accuracy
cosmic rays of galactic, solar, and trapped nature in a wide energy range
protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study
of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50
MeV-270 GeV) and search for antimatter with a precision of the order of 10^-8).
The experiment, housed on board the Russian Resurs-DK1 satellite, was launched
on June, 15, 2006 in a 350*600 km orbit with an inclination of 70 degrees. The
detector is composed of a series of scintillator counters arranged at the
extremities of a permanent magnet spectrometer to provide charge,
Time-of-Flight and rigidity information. Lepton/hadron identification is
performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at
the bottom of the device. An Anticounter system is used offline to reject false
triggers coming from the satellite. In self-trigger mode the Calorimeter, the
neutron detector and a shower tail catcher are capable of an independent
measure of the lepton component up to 2 TeV. In this work we describe the
experiment, its scientific objectives and the performance in the first months
after launch.Comment: Accepted for publication on Advances in Space Researc
The Repetitive Element RLEP Is a Highly Specific Target for Detection of Mycobacterium leprae
YesDamien Foundation, Belgium, and R2Stop, Canada. B.C.D.J. and C.J.M. were supported by the European Research Council-INTERRUPTB starting grant 311725
Different classes of genomic inserts contribute to human antibody diversity
Recombination of antibody genes in B cells can involve distant genomic loci and contribute a foreign antigen-binding element to form hybrid antibodies with broad reactivity for Plasmodium falciparum. So far, antibodies containing the extracellular domain of the LAIR1 and LILRB1 receptors represent unique examples of cross-chromosomal antibody diversification. Here, we devise a technique to profile non-VDJ elements from distant genes in antibody transcripts. Independent of the preexposure of donors to malaria parasites, non-VDJ inserts were detected in 80% of individuals at frequencies of 1 in 10(4) to 10(5) B cells. We detected insertions in heavy, but not in light chain or T cell receptor transcripts. We classify the insertions into four types depending on the insert origin and destination: 1) mitochondrial and 2) nuclear DNA inserts integrated at VDJ junctions; 3) inserts originating from telomere proximal genes; and 4) fragile sites incorporated between J-to-constant junctions. The latter class of inserts was exclusively found in memory and in in vitro activated B cells, while all other classes were already detected in naïve B cells. More than 10% of inserts preserved the reading frame, including transcripts with signs of antigen-driven affinity maturation. Collectively, our study unravels a mechanism of antibody diversification that is layered on the classical V(D)J and switch recombination
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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