4,255 research outputs found

    Facial implant gingival level and thickness changes following maxillary anterior immediate tooth replacement with scarf-connective tissue graft: A 4-13-year retrospective study

    Get PDF
    ObjectiveA scarf-shaped connective tissue graft can be placed at the facial and proximal aspect of the peri-implant soft tissue zone during immediate implant placement and provisionalization (IIPP) procedures in the esthetic zone to optimize implant esthetics without the need of flap reflection. This retrospective study evaluated soft tissue stability after scarf-connective tissue graft (S-CTG) in conjunction with IIPP procedures in the esthetic zone. Materials and MethodsPatients who received IIPP with S-CTG with a minimum 1-year follow-up were evaluated. Mid-facial gingival level (MFGL) change and mid-facial gingival thickness (MFGT) change were measured and compared at the pre-op (T0), IIPP + S-CTG surgery (T1), follow up appointment with MFGT measurement (T2), and latest follow-up appointment (T3). Implant success rate and graft necrosis were also recorded. ResultsA total of 22 IIPP and S-CTG procedures in 20 patients were evaluated in the study. After a mean follow-up of 8.2 years (3.9-13.4) (T3), all implants remained osseointegrated (22/22 [100%]), with statistically insignificant mean midfacial gingival level change of -0.19 mm (-1.5 to 0.8). Statistically significant difference in midfacial gingival thickness (MFGT) was noted (2.5 mm [1.8-3.5 mm]) after a mean follow-up time (T2) of 2.3 years (1-8.6) when compared with MFGT at baseline (1.1 mm [0.6-1.3 mm]) (T1). Necrosis of S-CTG during initial healing phase was noted in 9% (2/22) of the sites. ConclusionsWithin the confines of this study, scarf-connective tissue graft at time of immediate implant placement and provisionalization can thicken the gingiva and maintain the gingival level at the critical soft tissue zone. Clinical SignificanceManaging the soft tissue zone is as important as that of the hard tissue zone for peri-implant esthetics. Connective tissue graft is one of the methods that can enhance the final esthetic outcomes. This retrospective study has demonstrated that Scarf-CTG technique is an effective treatment modality to maintain soft tissue stability

    Beam Cooling with ionisation losses

    Full text link
    A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady configuration in which ionisation losses are recovered at each turn by a RF-cavity. For a uniform target "foil" the longitudinal momentum spread diverges exponentially since faster (slower) particles ionise less (more) than the average. In order to "cool" also longitudinally, a chromaticity has to be introduced with a wedge shaped "foil". Multiple scattering and straggling are then "cooled" in all three dimensions, with a method similar to the one of synchrotron cooling, but valid for low energy ions. Particles then stably circulate in the beam indefinitely, until they undergo for instance nuclear processes in the thin target foil. This new method is under consideration for the nuclear production of a few MeV/A ion beams. Simple reactions, for instance Li 7 + D Li 8 + p, are more favourably exploited with the heavier ion colliding against a gas-jet D2 target. Kinematics is generally very favourable, with emission angles in a narrow angular cone and a relatively concentrated outgoing energy spectrum which allows an efficient collection as a neutral gas in a tiny volume with a technology at high temperatures perfected at ISOLDE. It is however of a much more general applicability. The method appears capable of producing a "table top" storage ring with an accumulation rate in excess of 10**14 Li-8 radioactive ion/s for possible use for radioactive beams for physics studies (for example for beta-beams) or for therapy.Comment: 27 pages, 11 figure

    Signals for strange quark contributions to the neutrino (antineutrino) scattering in quasi-elastic region

    Full text link
    Strange quark contributions to the neutrino (antineutrino) scattering are investigated on the elastic neutrino-nucleon scattering and the neutrino-nucleus scattering for 12C target in the quasi-elastic region on the incident energy of 500 MeV, within the framework of a relativistic single particle model. For the neutrino-nucleus scattering, the effects of final state interaction for the knocked-out nucleon are included by a relativistic optical potential. In the cross sections we found some cancellations of the strange quark contributions between the knocked-out protons and neutrons. Consequently, the asymmetries between the incident neutrino and antineutrino which is the ratio of neutral current to charged current, and the difference between the asymmetries are shown to be able to yield more feasible quantities for the strangeness effects. In order to explicitly display importance of the cancellations, results of the exclusive reaction 16O(\nu, \nu' p) are additionally presented for detecting the strangeness effects.Comment: 14 pages, 8 figures, submitted to Phys. Lett.

    The Complementarity of Eastern and Western Hemisphere Long-Baseline Neutrino Oscillation Experiments

    Get PDF
    We present a general formalism for extracting information on the fundamental parameters associated with neutrino masses and mixings from two or more long baseline neutrino oscillation experiments. This formalism is then applied to the current most likely experiments using neutrino beams from the Japan Hadron Facility (JHF) and Fermilab's NuMI beamline. Different combinations of muon neutrino or muon anti-neutrino running are considered. To extract the type of neutrino mass hierarchy we make use of the matter effect. Contrary to naive expectation, we find that both beams using neutrinos is more suitable for determining the hierarchy provided that the neutrino energy divided by baseline (E/LE/L) for NuMI is smaller than or equal to that of JHF. Whereas to determine the small mixing angle, θ13\theta_{13}, and the CP or T violating phase δ\delta, one neutrino and the other anti-neutrino is most suitable. We make extensive use of bi-probability diagrams for both understanding and extracting the physics involved in such comparisons.Comment: 21 pages, Latex, 3 postscript figure

    Neutrino tomography - Learning about the Earth's interior using the propagation of neutrinos

    Full text link
    Because the propagation of neutrinos is affected by the presence of Earth matter, it opens new possibilities to probe the Earth's interior. Different approaches range from techniques based upon the interaction of high energy (above TeV) neutrinos with Earth matter, to methods using the MSW effect on the neutrino oscillations of low energy (MeV to GeV) neutrinos. In principle, neutrinos from many different sources (sun, atmosphere, supernovae, beams etc.) can be used. In this talk, we summarize and compare different approaches with an emphasis on more recent developments. In addition, we point out other geophysical aspects relevant for neutrino oscillations.Comment: 22 pages, 9 figures. Proceedings of ``Neutrino sciences 2005: Neutrino geophysics'', December 14-16, 2005, Honolulu, USA. Minor changes, some references added. Final version to appear in Earth, Moon, and Planet

    Working Group Report: Neutrino and Astroparticle Physics

    Get PDF
    This is the report of neutrino and astroparticle physics working group at WHEPP-8. We present the discussions carried out during the workshop on selected topics in the above fields and also indicate progress made subsequently. The neutrino physics subgroup studied the possibilites of constraining neutrino masses, mixing and CPT violation in lepton sector from future experiments. Neutrino mass models in the context of abelian horizontal symmetries, warped extra dimensions and in presence of triplet Higgs were studied. Effect of threshold corrections on radiative magnification of mixing angles was investigated. The astroparticle physics subgroup focused on how various particle physics inputs affect the CMBR fluctuation spectrum, and on brane cosmology. This report also contains an introduction on how to use the publicly available code CMBFAST to calculate the CMBR fluctuations.Comment: Prepared for the 8th Workshop on High-Energy Physics Phenomenology (WHEPP-8), IIT Mumbai, India, 5-16 Jan 200

    A Beta Beam complex based on the machine upgrades for the LHC

    Get PDF
    The Beta Beam CERN design is based on the present LHC injection complex and its physics reach is mainly limited by the maximum rigidity of the SPS. In fact, some of the scenarios for the machine upgrades of the LHC, particularly the construction of a fast cycling 1 TeV injector (``Super-SPS''), are very synergic with the construction of a higher γ\gamma Beta Beam. At the energies that can be reached by this machine, we demonstrate that dense calorimeters can already be used for the detection of ν\nu at the far location. Even at moderate masses (40 kton) as the ones imposed by the use of existing underground halls at Gran Sasso, the CP reach is very large for any value of θ13\theta_{13} that would provide evidence of νe\nu_e appearance at T2K or NOν\nuA (θ133\theta_{13}\geq 3^\circ). Exploitation of matter effects at the CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy in significant areas of the θ13δ\theta_{13}-\delta plane

    Interactions between Glutathione S-Transferase P1, Tumor Necrosis Factor, and Traffic-Related Air Pollution for Development of Childhood Allergic Disease

    Get PDF
    BACKGROUND: Air pollutants may induce airway inflammation and sensitization due to generation of reactive oxygen species. The genetic background to these mechanisms could be important effect modifiers. OBJECTIVE: Our goal was to assess interactions between exposure to air pollution and single nucleotide polymorphisms (SNPs) in the beta2-adrenergic receptor (ADRB2), glutathione S-transferase P1 (GSTP1), and tumor necrosis factor (TNF) genes for development of childhood allergic disease. METHODS: In a birth cohort originally of 4,089 children, we assessed air pollution from local traffic using nitrogen oxides (traffic NO(x)) as an indicator based on emission databases and dispersion modeling and estimated individual exposure through geocoding of home addresses. We measured peak expiratory flow rates and specific IgE for inhalant and food allergens at 4 years of age, and selected children with asthma symptoms up to 4 years of age (n = 542) and controls (n = 542) for genotyping. RESULTS: Interaction effects on allergic sensitization were indicated between several GSTP1 SNPs and traffic NO(x) exposure during the first year of life (p(nominal) < 0.001-0.06). Children with Ile105Val/Val105Val genotypes were at increased risk of sensitization to any allergen when exposed to elevated levels of traffic NO(x) (for a difference between the 5th and 95th percentile of exposure: odds ratio = 2.4; 95% confidence interval, 1.0-5.3). In children with TNF-308 GA/AA genotypes, the GSTP1-NO(x) interaction effect was even more pronounced. We observed no conclusive interaction effects for ADRB2. CONCLUSION: The effect of air pollution from traffic on childhood allergy appears to be modified by GSTP1 and TNF variants, supporting a role of genes controlling the antioxidative system and inflammatory response in allergy

    Neutrino hierarchy from CP-blind observables with high density magnetized detectors

    Get PDF
    High density magnetized detectors are well suited to exploit the outstanding purity and intensities of novel neutrino sources like Neutrino Factories and Beta Beams. They can also provide independent measurements of leptonic mixing parameters through the observation of atmospheric muon-neutrinos. In this paper, we discuss the combination of these observables from a multi-kton iron detector and a high energy Beta Beam; in particular, we demonstrate that even with moderate detector granularities the neutrino mass hierarchy can be determined for θ13\theta_{13} values greater than 4^\circ.Comment: 16 pages, 7 figures. Added a new section discussing systematic errors (sec 5.2); sec.5.1 and 4 have been extended. Version to appear in EPJ
    corecore