4,947 research outputs found
Maxillary nerve block: A comparison between the greater palatine canal and high tuberosity approaches.
Aim: Analgesia and anxiolysis during dental procedures are important for dental care and
patient compliance. This study aims to compare two classical maxillary nerve block (MNB)
techniques: the greater palatine canal (GPC) and the high tuberosity (HT) approaches,
seldom used in routine dental practice.
Methods: The study was conducted on 30 patients, scheduled for sinus lift surgery, who
were randomly divided into 2 groups: the GPC approach to the MNB was used in 15 and the
HT one in the other 15 patients. Anxiolysis was also used, depending on the results of the
pre- preoperative assessment. Patients\u2019 sensations/pain during the procedure, details about
anesthesia, and the dentist\u2019s considerations were all recorded. Data are expressed as mean
\ub1SD. Statistical tests including ANOVA, \u3c72 following Yates correction and linear regression
analysis were carried out. A < 0.05 p value was considered significant.
Results: Study results showed that the anesthesia was effective and constant in the molar
and premolar area. Additional infiltrations of local anesthetics were necessary for vestibular
and palatal areas in the anterior oral cavity, respectively, in the GPC and HT groups. The
two techniques were equally difficult to carry out in the dentist\u2019s opinion. There were
no differences in pain or unpleasant sensations between the two groups, nor were any
anesthesia-related complications reported.
Conclusion: The GPC approach ensures effective anesthesia in the posterior maxillary
region as far as both the dental pulp and the palatal/vestibular mucous membranes are
concerned; the HT approach did not guarantee adequate anesthesia of the pterygopalatine
branch of the maxillary nerve. These regional anesthesia techniques were characterized
by a low incidence of intra and postoperative pain, no noteworthy complications, and high
patient satisfaction
Magnetic Raman Scattering of Insulating Cuprates
We study the and Raman profiles of MCu (with
M= La, Pr, Nd, Sm, Gd), BiSrCaYCuO%,
YBaCuO and PrBaCuAlO insulating
cuprates within the Loudon-Fleury theory, in the framework of an extended
Hubbard model for moderate on-site Coulomb interaction . We calculate the
non-resonant contribution to these Raman profiles by using exact
diagonalization techniques and analyze two types of contributing mechanisms to
the line shapes: 4-spin cyclic exchange and spin-phonon interactions. Although
these interactions contribute to different parts of the spectra, together, they
account for the enhanced linewidth and asymmetry of the mode, as well
as the non-negligible intensity of the Raman line observed in these
materials.Comment: 8 pages, 2 eps figures. To be published in PR
Study of RPC gas mixtures for the ARGO-YBJ experiment
The ARGO-YBJ experiment consists of a RPC carpet to be operated at the
Yangbajing laboratory (Tibet, P.R. China), 4300 m a.s.l., and devoted to the
detection of showers initiated by photon primaries in the energy range 100 GeV
- 20 TeV. The measurement technique, namely the timing on the shower front with
a few tens of particles, requires RPC operation with 1 ns time resolution, low
strip multiplicity, high efficiency and low single counting rate. We have
tested RPCs with many gas mixtures, at sea level, in order to optimize these
parameters. The results of this study are reported.Comment: 6 pages, 3 figures. To be published in Nucl. Instr. Meth. A, talk
given at the "5th International Workshop on RPCs and Related Detectors", Bari
(Italy) 199
Pulse-Shape Discrimination of CaF2(Eu)
We measured the decay time of the scintillation pulses produced by electron
and nuclear recoils in CaF2(Eu) by a new fitting method. In the recoil energy
region 5-30 keVee, we found differences of the decay time between electron and
nuclear recoil events. In the recoil energy region above 20 keVee, we found
that the decay time is independent of the recoil energy.Comment: 10 pages, 4 figure
High intensity X/ γ photon beams for nuclear physics and photonics
In this manuscript we review the challenges of Compton back-scattering sources in advancing photon beam performances in the1−20MeVenergy range, underlining the design criteria bringing tomaximum spectral luminosity and briefly describing the main achieve-ments in conceiving and developing new devices (multi-bunch RF cav-ities and Laser recirculators) for the case of ELI-NP Gamma BeamSystem (ELI-NP-GBS)
EuPRAXIA@SPARC_LAB: the high-brightness RF photo-injector layout proposal
At EuPRAXIA@SPARC_LAB, the unique combination of an advanced high-brightness
RF injector and a plasma-based accelerator will drive a new multi-disciplinary
user-facility. The facility, that is currently under study at INFN-LNF
Laboratories (Frascati, Italy) in synergy with the EuPRAXIA collaboration, will
operate the plasma-based accelerator in the external injection configuration.
Since in this configuration the stability and reproducibility of the
acceleration process in the plasma stage is strongly influenced by the
RF-generated electron beam, the main challenge for the RF injector design is
related to generating and handling high quality electron beams. In the last
decades of R&D activity, the crucial role of high-brightness RF photo-injectors
in the fields of radiation generation and advanced acceleration schemes has
been largely established, making them effective candidates to drive
plasma-based accelerators as pilots for user facilities. An RF injector
consisting in a high-brightness S-band photo-injector followed by an advanced
X-band linac has been proposed for the EuPRAXIA@SPARC_LAB project. The electron
beam dynamics in the photo-injector has been explored by means of simulations,
resulting in high-brightness, ultra-short bunches with up to 3 kA peak current
at the entrance of the advanced X-band linac booster. The EuPRAXIA@SPARC_LAB
high-brightness photo-injector is described here together with performance
optimisation and sensitivity studies aiming to actual check the robustness and
reliability of the desired working point.Comment: 5 pages,5 figures, EAAC201
New results from an extensive aging test on bakelite Resistive Plate Chambers
We present recent results of an extensive aging test, performed at the CERN
Gamma Irradiation Facility on two single--gap RPC prototypes, developed for the
LHCb Muon System. With a method based on a model describing the behaviour of an
RPC under high particle flux conditions, we have periodically measured the
electrode resistance R of the two RPC prototypes over three years: we observe a
large spontaneous increase of R with time, from the initial value of about 2
MOhm to more than 250 MOhm. A corresponding degradation of the RPC rate
capabilities, from more than 3 kHz/cm2 to less than 0.15 kHz/cm2 is also found.Comment: 6 pages, 7 figures, presented at Siena 2002, 8th Topical Seminar on
Innovative Particle and Radiation Detectors 21-24 October 2002, Siena, Ital
Resonant two-magnon Raman scattering in parent compounds of high-T superconductors.
We propose a theory of two-magnon Raman scattering from the insulating parent
compounds of high-T superconductors, which contains information not only on
magnetism, but also on the electronic properties in these materials. We use
spin density wave formalism for the Hubbard model, and study diagrammatically
the profile of the two-magnon scattering and its intensity dependence on the
incoming photon frequency both for and in the
resonant regime, in which the energy of the incident photon is close to the gap
between conduction and valence bands. In the nonresonant case, we identify the
diagrams which contribute to the conventional Loudon-Fleury Hamiltonian. In the
resonant regime, where most of the experiments have been done, we find that the
dominant contribution to Raman intensity comes from a different diagram, one
which allows for a simultaneous vanishing of all three of its denominators
(i.e., a triple resonance). We study this diagram in detail and show that the
triple resonance, combined with the spin-density-wave dispersion relation for
the carriers, explains the unusual features found in the two-magnon profile and
in the two-magnon peak intensity dependence on the incoming photon frequency.
In particular, our theory predicts a maximum of the two-magnon peak intensity
right at the upper edge of the features in the optical data, which has been one
of the key experimental puzzles.Comment: Revtex, 12 postscript figures (uuencoded
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