Análise de densidade linear para reparo ósseo em ratos utilizando radiografia digital direta

The objective of this study was to assess bone density measurements for analysis of repairing fractures in rats using direct digital radiography under Dexamethasone effects. Thirty (30) young adult male Wistar rats were used, with an average weight of 200g, which were submitted to general anesthetics by ethyl ether. One rib of each animal was fractured by surgical technique. The rats were divided into 2 groups, named Control group - intraperitoneal administration of saline solution 1 hour prior to operation, and Group 1: intraperitoneal administration of Dexamethasone 0.1mg/Kg of weight 1 hour prior to operation, and two postoperative doses every 12 hours. The animals were sacrificed at 2, 3, 4, 7 and 14 days. The parts containing the hemi-thorax with the fractured rib were removed and submitted to direct digital radiography, where the linear density of the two extremities of the fracture were analyzed by the Digora System. The results showed that in the control group and in Group 1 there was a gradual and significant increase in linear density. The method used made it feasible to supply data that were statistically significant in assessing the gain in bone density during the period of time analyzed. In conclusion, direct digital radiograph is useful for bone density analysis for fracture repairing. The dose of Dexamethasone was not sufficient to alter the gain in bone density at the extremities of fracture.O objetivo deste estudo foi analisar densidade linear utilizando o sistema de radiografia digital direta intrabucal para verificar o ganho de densidade óssea em fraturas de ratos sob os efeitos da Dexametasona. Trinta (30) ratos Wistar machos, adultos jóvens de 200 g em média foram usados. Os animais foram submetidos á anestesia geral por inalação de éter etílico e 01 costela de cada animal foi fraturada através de técnica cirúrgica. Os ratos foram divididos em grupos de 03 repetições para cada grupo em cada período de tempo: Grupo Controle: administração intraperitoneal de soro fisiológico 01 hora antes da intervenção cirúrugica. Grupo 1: administração intraperitoneal de Dexametasona 0.1mg/Kg de peso 01 hora antes da intervenção e duas doses pós operatórias a cada 12 horas. Os animais foram sacrificados com 02, 03, 04, 07 e 14 dias. As partes contendo o hemi tórax da costela com a fratura foram removidas e submetidas aos raios x, onde as imagens foram analisadas através do sistema Digora. Os resultados mostraram que no grupo Controle e no Grupo 1 houve um ganho gradual na densidade linear. O método utilizado para análise forneceu dados estatisticamente significativos durante o período de tempo analisado. Assim concluimos que o método de radiografia dentária digital pode ser utilizado para análise de densidade linear de fraturas. As doses utilizadas de Dexametasona neste experimento não foram suficientes para alterar a densidade óssea no reparo de fraturas em ratos

Análise de densidade linear para reparo ósseo em ratos utilizando radiografia digital direta

The objective of this study was to assess bone density measurements for analysis of repairing fractures in rats using direct digital radiography under Dexamethasone effects. Thirty (30) young adult male Wistar rats were used, with an average weight of 200g, which were submitted to general anesthetics by ethyl ether. One rib of each animal was fractured by surgical technique. The rats were divided into 2 groups, named Control group - intraperitoneal administration of saline solution 1 hour prior to operation, and Group 1: intraperitoneal administration of Dexamethasone 0.1mg/Kg of weight 1 hour prior to operation, and two postoperative doses every 12 hours. The animals were sacrificed at 2, 3, 4, 7 and 14 days. The parts containing the hemi-thorax with the fractured rib were removed and submitted to direct digital radiography, where the linear density of the two extremities of the fracture were analyzed by the Digora System. The results showed that in the control group and in Group 1 there was a gradual and significant increase in linear density. The method used made it feasible to supply data that were statistically significant in assessing the gain in bone density during the period of time analyzed. In conclusion, direct digital radiograph is useful for bone density analysis for fracture repairing. The dose of Dexamethasone was not sufficient to alter the gain in bone density at the extremities of fracture.O objetivo deste estudo foi analisar densidade linear utilizando o sistema de radiografia digital direta intrabucal para verificar o ganho de densidade óssea em fraturas de ratos sob os efeitos da Dexametasona. Trinta (30) ratos Wistar machos, adultos jóvens de 200 g em média foram usados. Os animais foram submetidos á anestesia geral por inalação de éter etílico e 01 costela de cada animal foi fraturada através de técnica cirúrgica. Os ratos foram divididos em grupos de 03 repetições para cada grupo em cada período de tempo: Grupo Controle: administração intraperitoneal de soro fisiológico 01 hora antes da intervenção cirúrugica. Grupo 1: administração intraperitoneal de Dexametasona 0.1mg/Kg de peso 01 hora antes da intervenção e duas doses pós operatórias a cada 12 horas. Os animais foram sacrificados com 02, 03, 04, 07 e 14 dias. As partes contendo o hemi tórax da costela com a fratura foram removidas e submetidas aos raios x, onde as imagens foram analisadas através do sistema Digora. Os resultados mostraram que no grupo Controle e no Grupo 1 houve um ganho gradual na densidade linear. O método utilizado para análise forneceu dados estatisticamente significativos durante o período de tempo analisado. Assim concluimos que o método de radiografia dentária digital pode ser utilizado para análise de densidade linear de fraturas. As doses utilizadas de Dexametasona neste experimento não foram suficientes para alterar a densidade óssea no reparo de fraturas em ratos.31732

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Odderon Exchange from Elastic Scattering Differences between pp and pp−^{-} Data at 1.96 TeV and from pp Forward Scattering Measurements

We describe an analysis comparing the p¯p elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM crosssections, extrapolated to a center-of-mass energy of √s=1.96  TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4σ level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scatteringamplitude in pp scattering for which the significance is between 3.4σ and 4.6σ. The combined significance is larger than 5σ and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The second-order Fourier coefficients (v(2)) characterizing the azimuthal distributions of Y(1S) and Y(2S) mesons produced in PbPb collisions at root s(NN) = 5.02 TeV are studied. The Y mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb(-1). The scalar product method is used to extract the v2 coefficients of the azimuthal distributions. Results are reported for the rapidity range vertical bar y vertical bar < 2.4, in the transverse momentum interval 0 < pT < 50 GeV/c, and in three centrality ranges of 10-30%, 30-50% and 50-90%. In contrast to the J/psi mesons, the measured v(2) values for the Y mesons are found to be consistent with zero. (C) 2021 The Author(s). Published by Elsevier B.V.Peer reviewe

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in pp Collisions at root s=13 TeV

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at root s = 13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lepton + jets channel of t (t) over bar events, where the lepton is an electron or muon. The products of the hadronic top quark decay t -> bW -> bq (q) over bar' are reconstructed as a single jet with transverse momentum larger than 400 GeV. The t (t) over bar cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6 +/- 2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.Peer reviewe

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat