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
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
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
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
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
() for NuMI is smaller than or equal to that of JHF. Whereas to determine
the small mixing angle, , and the CP or T violating phase
, 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
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
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
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 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 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
that would provide evidence of appearance at T2K or
NOA (). Exploitation of matter effects at the
CERN to Gran Sasso distance provides sensitivity to the neutrino mass hierarchy
in significant areas of the plane
Interactions between Glutathione S-Transferase P1, Tumor Necrosis Factor, and Traffic-Related Air Pollution for Development of Childhood Allergic Disease
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
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 values greater than 4.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
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