Clinical and microbiological effects of copaiba oil (Copaifera officinalis) on dental plaque forming bacteria in dogs

O potencial de uso do óleo de copaíba (Copaifera officinalis) na prevenção da doença periodontal, eliminando seu agente etiológico, foi avaliado em 18 cães sem raça definida, distribuídos homogeneamente em três grupos: teste, (contendo óleo de copaíba) controle positivo e controle negativo. Os tratamentos ocorreram três vezes ao dia, durante oito dias. Ao nono dia, os animais receberam aplicação tópica de fucsina básica 0,5% para evidenciação do biofilme. Mudanças na halitose e gengivite foram avaliadas diariamente por inspeção visual. Adicionalmente, foram realizados testes laboratoriais de inibição de aderência de Streptococcus mutans e ensaio antimicrobiano de difusão em ágar, sobre bactérias formadoras de placa dental. Os resultados da placa evidenciada apontaram áreas de cobertura microbiana nos dentes de 53,4±8,8%, 28,5±5,4%, e 22,3±5,3% para os grupos negativo, positivo e teste, respectivamente, indicando diferença entre o controle negativo e os demais grupos (P<0,05). Quanto à melhora nos aspectos clínicos, halitose e gengivite, o grupo teste respondeu melhor quando comparado ao grupo controle negativo (P<0,05). A análise dos ensaios de difusão e inibição de aderência mostrou superioridade do grupo da copaíba (teste) em relação aos outros grupos (P<0,05). Os resultados sugerem o uso do óleo de copaíba na prevenção da doença periodontal e como um possível substituto da clorexidina na terapia antimicrobiana oral.The copaiba oil (Copaifera officinalis) potential was evaluated in preventing periodontal disease and reducing its etiology. For that 18 mongrel dogs were homogeneously distributed in three groups: test (copaiba oil), positive control (chlorexidine) and negative control. The treatments were carried out three times a day, during eight days. On the 9th day, the animals were tested with a 0.5% basic solution of fuchsin for the detection of biofilm. Changes in halitosis and gingivitis were daily observed. In addition, the following laboratory tests were done: inhibition of the adherence of Streptococcus mutans, and plaque forming bacteria antimicrobial assays by the agar diffusion method. The results of the fuchsin test showed that dental plaque reached areas of 53.4±8.8%, 28.5±5.4%, and 22.3±5.3% in the negative control, positive control, and test groups, respectively, showing differences between dogs from the negative control group and dogs from the other two groups (P<0.05). Furthermore, halitosis and gingivitis decreased in the copaiba group animals when compared with the negative group (P<0.05). The results of the attachment inhibition and agar diffusion tests showed that copaiba induced better effects against the microorganisms as compared to the results of the other groups (P<0.05). These findings suggest that copaiba oil may effectively replace chlorexidine for oral antimicrobial therapy and prevention of periodontal disease.FAPEMI

A New Approach to Searching for Dark Matter Signals in Fermi-LAT Gamma Rays

Several cosmic ray experiments have measured excesses in electrons and positrons, relative to standard backgrounds, for energies from ~ 10 GeV - 1 TeV. These excesses could be due to new astrophysical sources, but an explanation in which the electrons and positrons are dark matter annihilation or decay products is also consistent. Fortunately, the Fermi-LAT diffuse gamma ray measurements can further test these models, since the electrons and positrons produce gamma rays in their interactions in the interstellar medium. Although the dark matter gamma ray signal consistent with the local electron and positron measurements should be quite large, as we review, there are substantial uncertainties in the modeling of diffuse backgrounds and, additionally, experimental uncertainties that make it difficult to claim a dark matter discovery. In this paper, we introduce an alternative method for understanding the diffuse gamma ray spectrum in which we take the intensity ratio in each energy bin of two different regions of the sky, thereby canceling common systematic uncertainties. For many spectra, this ratio fits well to a power law with a single break in energy. The two measured exponent indices are a robust discriminant between candidate models, and we demonstrate that dark matter annihilation scenarios can predict index values that require "extreme" parameters for background-only explanations.Comment: v1: 11 pages, 7 figures, 1 table, revtex4; v2: 13 pages, 8 figures, 1 table, revtex4, Figure 4 added, minor additions made to text, references added, conclusions unchanged, published versio

On Dark Matter Annihilation in the Local Group

Under the hypothesis of a Dark Matter composed by supersymmetric particles like neutralinos, we investigate the possibility that their annihilation in the haloes of nearby galaxies could produce detectable fluxes of $\gamma$-photons. Expected fluxes depend on several, poorly known quantities such as the density profiles of Dark Matter haloes, the existence and prominence of central density cusps and the presence of a population of sub-haloes. We find that, for all reasonable choices of Dark Matter halo models, the intensity of the $\gamma$-ray flux from some of the nearest extragalactic objects, like M31, is comparable or higher than the diffuse Galactic foreground. We show that next generation ground-based experiments could have the sensitivity to reveal such fluxes which could help us unveiling the nature of Dark Matter particles.Comment: 11 pages, 10 figures. Accepted for publication in Phys. Rev. D.; added a new paragraph on the detectability of Galactic sub-halos in our Galaxy; added a discussion on their model dependence. The relation of our results with the "CDM crisis" issue has also been adde

Study of Inclusive Strange-Baryon Production and Search for Pentaquarks in Two-Photon Collisions at LEP

Measurements of inclusive production of the Lambda, Xi- and Xi*(1530) baryons in two-photon collisions with the L3 detector at LEP are presented. The inclusive differential cross sections for Lambda and Xi- are measured as a function of the baryon transverse momentum, pt, and pseudo-rapidity, eta. The mean number of Lambda, Xi- and Xi*(1530) baryons per hadronic two-photon event is determined in the kinematic range 0.4 GeV < pt< 2.5 GeV, |eta| < 1.2. Overall agreement with the theoretical models and Monte Carlo predictions is observed. A search for inclusive production of the pentaquark theta+(1540) in two-photon collisions through the decay theta+ -> proton K0s is also presented. No evidence for production of this state is found

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters

Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO