6,284 research outputs found
NeXSPheRIO results on elliptic flow at RHIC and connection with thermalization
Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. Reasonable
agreement with experimental results on is obtained. Various effects
are studied as well: reconstruction of impact parameter direction, freeze out
temperature, equation of state (with or without crossover), emission mecanism.Comment: Contribution to the Proceedings of the Quark-Gluon Plasma
Thermalization workshop. Content slightly increase
Fluctuation of the Initial Conditions and Its Consequences on Some Observables
We show effects of the event-by-event fluctuation of the initial conditions
(IC) in hydrodynamic description of high-energy nuclear collisions on some
observables. Such IC produce not only fluctuations in observables but, due to
their bumpy structure, several non-trivial effects appear. They enhance
production of isotropically distributed high-pT particles, making v2 smaller
there. Also, they reduce v2 in the forward and backward regions where the
global matter density is smaller, so where such effects become more
efficacious. They may also produce the so-called ridge effect in the two
large-pT particle correlation.Comment: 6 pages, 6 figures, presented at the IV Workshop on Particle
Correlations and Femtoscopy (WPCF2008), Krakow, Poland, 11-14 Sep 200
Effects of LatticeQCD EoS and Continuous Emission on Some ObseErvables
Effects of lattice-QCD-inspired equations of state and continuous emission on
some observables are discussed, by solving a 3D hydrodynamics. The particle
multiplicity as well as v2 are found to increase in the mid-rapidity. We also
discuss the effects of the initial-condition fluctuations.Comment: 6 pages, 10 figures, prepared for Workshop on Particle Correlations
and Fentoscopy, Kromeriz (Czech Republic), Aug. 15-17,200
Evaluation of salivary matrix metalloproteinase (MMP-8) in periodontal patients undergoing non-surgical periodontal therapy and mouthwash based on ozonated olive oil: A randomized clinical trial
Background: Extracellular matrix metalloproteinases (MMPs) play a pivotal role in the damage to the periodontal tissue in patients with periodontitis. Scaling and root planning (SRP) attempt to control the plaque amount and consequentially reduce the bacterial load. Non-surgical periodontal treatment could be integrated with drug therapy and physiotherapy procedures such as ozone therapy. The aim of this study was to evaluate in a cohort of patients with a diagnosis of periodontitis: (1) the efficacy of non-surgical periodontal therapy assisted by the use of ozonated olive oil-based mouthwash on salivary metalloproteinase (MMP-8) and (2) the reduction of periodontal indices. Methods: Ninety-six subjects with a diagnosis of periodontitis were enrolled in this study and randomly assigned to the study group (SRP + mouthwash) or control group (SRP). The study duration was 3 months. Data on MMP-8, plaque index (PI), bleeding on probing (BoP) and probing pocket depth (PPD) were recorded at T0, T1 (14 days), T2 (1 month) and T3 (6 months). Group differences were assessed using Student’s t-test for independent samples. Results: A significant improvement in PI, BoP, PPD and salivary MMP-8 levels was observed in both groups. An analysis of differences in relative changes of indices revealed the efficacy of ozonated olive oil in decreasing MMP-8 level. Simultaneously, it slowed the decrease of BoP index. Conclusions: Scaling and root plaining with the aid of ozonated olive oil mouthwash were found to be more effective on salivary MMP-8 reduction than scaling and root plaining alone
Modelling the role of electron attachment rates on column density ratios for CnH-/CnH (n=4; 6; 8) in dense molecular clouds
(abridged) The fairly recent detection of a variety of anions in the
Interstellar Molecular Clouds have underlined the importance of realistically
modeling the processes governing their abundance. To this aim, our earlier
calculations for the radiative electron attachment (REA) rates for C4H-, C6H-,
and C8H- are employed to generate the corresponding column density ratios of
anion/neutral (A/N) relative abundances. The latter are then compared with
those obtained from observational measurements. The calculations involved the
time-dependent solutions of a large network of chemical processes over an
extended time interval and included a series of runs in which the values of REA
rates were repeatedly scaled. Macroscopic parameters for the clouds' modeling
were also varied to cover a broad range of physical environments. It was found
that, within the range and quality of the processes included in the present
network,and selected from state-of-the-art astrophysical databases, the REA
values required to match the observed A/N ratios needed to be reduced by orders
of magnitude for C4H- case, while the same rates for C6H- and C8H- only needed
to be scaled by much smaller factors. The results suggest that the generally
proposed formation of interstellar anions by REA mechanism is overestimated by
current models for the C4H- case, for which is likely to be an inefficient path
to formation. This path is thus providing a rather marginal contribution to the
observed abundances of C4H-, the latter being more likely to originate from
other chemical processes in the network, as we discuss in some detail in the
present work.Possible physical reasons for the much smaller differences against
observations found instead for the values of the (A/N) ratios in two other,
longer members of the series are put forward and analyzed within the
evolutionary modeling discussed in the present work.Comment: Journal of Physics B, accepte
On the necessity to include event-by-event fluctuations in experimental evaluation of elliptical flow
Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. We show
that when symmetry of the particle distribution in relation to the reaction
plane is assumed, as usually done in the experimental extraction of elliptic
flow, there is a disagreement between the true and reconstructed elliptic flows
(15-30% for =0, 30% for =0.5 GeV). We suggest a possible way to
take into account the asymmetry and get good agreement between these elliptic
flows
Stretched chemical bonds in Si6H6: A transition from ring currents to localized pi-electrons?
Motivated by solid-state studies on the cleavage force in Si, and the
consequent stretching of chemical bonds, we here study bond stretching in the,
as yet unsynthesized, free space molecule Si6H6. We address the question as to
whether substantial bond stretching (but constrained to uniform scaling on all
bonds) can result in a transition from ring current behaviour, characteristic
say of benzene at its equilibrium geometry, to localized pi-electrons on Si
atoms. Some calculations are also recorded on dissociation into 6 SiH radicals.
While the main studies have been carried out by unrestricted Hartree-Fock (HF)
theory, the influence of electron correlation has been examined using two forms
of density functional theory. Planar Si6H6 treated by HF is bound to be
unstable, not all vibrational frequencies being real. Some buckling is then
allowed, which results in real frequencies and stability. Evidence is then
provided that the non-planar structure, as the Si-Si distance is increased,
exhibits pi-electron localization in the range 1.2-1.5 times the equilibrium
distance
In vitro activity of ozonated olive oil-based products against carious pathogen streptococcus mutans
Early mandibular canine-lateral incisor transposition: case report
Purpose. The main aim of the present study is to present a case of mandibular transposition between lateral incisor and
canine in a paediatric patient.
Materials and methods. A fixed multibracket orthodontic treatment was performed by means of a modified welded arch
as to correct the transposition and obtaining a class I functional and symmetrical occlusion, also thanks to the early diagnosis
of the eruption anomaly.
Results. Our case report shows that a satisfactory treatment of mandibular transpositions is obtained when detected at
an early stage of the tooth development.
Conclusions. The main treatment options to be taken into consideration in case of a mandibular transposition are two:
correcting the transposition or aligning it leaving the dental elements in their transposed order; in both cases, the followups
show a stable condition, maintained without relapses. Several factors, such as age of the patient, occlusion, aesthetics,
patient’s collaboration, periodontal support and duration of treatment have to be considered as to prevent potential damage
to dental elements and support appliances. The choice between the two treatment approaches for mandibular lateral
incisor/canine transpositions mainly depends on the time the anomaly is detected
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