298 research outputs found
Unconventional and conventional quantum criticalities in CeRhIrIn
An appropriate description of the state of matter that appears as a second
order phase transition is tuned toward zero temperature, {\it viz.}
quantum-critical point (QCP), poses fundamental and still not fully answered
questions. Experiments are needed both to test basic conclusions and to guide
further refinement of theoretical models. Here, charge and entropy transport
properties as well as AC specific heat of the heavy-fermion compound
CeRhIrIn, measured as a function of pressure, reveal two
qualitatively different QCPs in a {\it single} material driven by a {\it
single} non-symmetry-breaking tuning parameter. A discontinuous sign-change
jump in thermopower suggests an unconventional QCP at accompanied by
an abrupt Fermi-surface reconstruction that is followed by a conventional
spin-density-wave critical point at across which the Fermi surface
evolves smoothly to a heavy Fermi-liquid state. These experiments are
consistent with some theoretical predictions, including the sequence of
critical points and the temperature dependence of the thermopower in their
vicinity.Comment: 21+3 pages, 4+2 figures. Change the title, figures et a
The Entrainment Rate of NonâBoussinesq Hazardous Geophysical GasâParticle Flows: An Experimental Model With Application to Pyroclastic Density Currents
The entrainment rate of pyroclastic density currents is investigated by largeâscale experiments. The ground flows are initiated by the impact on the terrain of a dense gasâparticle fountain issuing from a cylindrical conduit, similarly to natural volcanic events. On impact, the excess density with respect to the surrounding atmosphere was up to 11.6 kg/m3, making the currents nonâBoussinesq. A power law model of the entrainment rate is developed, which is similar to that proposed for snow avalanches by Ancey (2004, https://doi.org/10.1029/2003JF000052) and is verified for the Richardson's number range between 0.25 and 5.95. Rapid changes of the entrainment are caused by (i) strong accelerations at the fountain impact on the ground; (ii) break in slope; and (iii) topographic obstacles. Such changes, together with the sedimentation rate, influence flow mobility. The use of the power law is suggested for modeling the motion of unsteady hazardous geophysical mass flows such as pyroclastic density currents and snow avalanches
Minimally invasive approach to eliminate pyogenic granuloma using Er, Cr: YSGG laser
Backgroung. PG or granuloma pyogenicum is a common tumor like growth of the oral cavity that is considered to be
of non-neoplastic nature, arising commonly as a result of constant low grade trauma and poor oral hygiene and in few instances because of hormonal disturbances. Since it is a benign lesion, choice of treatment is surgical excision with removal of underlying cause if any. A newer treatment modality using laser has been reported.
Case report. A 16-year-old male patient reported to our sector of oral medicine with the chief complaint of intra-oral
painless growth since four months. Past history and medical history did not reveal any relevant information. He was
taking no medication and had no history of known drug allergy. On intra-oral examination smooth surfaced and lobulated growth of approximately 1.5 Ă 1 Ă 0.5 cm in size was present in the palate. The lesion was pedunculated and
was freely movable over peduncle. The surface of the lesion showed non-omogenous red color whereas in certain
area was covered by yellowish plaque like material. On palpation, growth was non-tender, nonfluctuant, hard and fibrous in consistency. Treatment plan comprising of excisional biopsy of the lesion using an Er, Cr: YSGG laser. An
elliptical incision was made around the peduncle, the lesion was lifted along with the underlying periosteum from the
bone surface and removed. Hemostasis was achieved with the same laser and healing was obtained for second intention.
Excised specimen was preserved and sent for histopathological examination. At 7 days recall, the gingival tissues were healthy with successful healing.
Conclusion. Excisional surgery is the treatment of choice for PG. The use of laser may be a valid approach for the
excision of this lesion, as it is minimally invasive and offers many clinical advantages (minimal intra-operative bleeding,hemostasis, reduced times of healing)
Analisi delle condizioni ambientali in tre aziende lattiero-casearie lombarde
The environmental conditions of three dairies were ascertained, in order to guarantee the highest level of comfort of the operators and hygiene of the production. Environmental conditions have been characterized by measurements of noise, lighting, air humidity and temperature. Cleaning and washing of tools and machines are the noisiest operations; some workplaces do not comply with the optimum conditions for lighting, recommended by UNI 10380, 10530 and ISO 8995 standards. Temperature and humidity trends follow strictly the various steps of the processes, so they increase rapidly when steam pumps start. The main problems highlighted are: an unfavourable layout, old and worn plants, a poor organization of the job and an inadequate behaviour of the staff. An adequate planning of the workstations is highly recommended, in order to guarantee safety and quality of the production process. At the same time, the operators must be informed and formed on specific risks and the suitable behaviours to be adopted
The effect of maxillary protraction, with or without rapid palatal expansion, on airway dimensions: A systematic review and meta-analysis
Aim The use of maxillary protraction appliances (MPAs) and Facemask (FM), with or without a rapid maxillary expansion (RME), have become a routine orthopaedic treatment procedure for the treatment of Class III in growing individuals; several authors have suggested that maxillary protraction could have a positive impact on airway dimensions. The purpose of this systematic review and meta- analysis was to assess the efficacy of maxillary protraction appliances (MPAs), with or without a rapid maxillary expansion (RME), on airway dimensions in children in mixed or early permanent dentition.
Methods An electronic search was performed on PubMed, Medline, Scopus, The Cochrane Library, EMBASE and the System for Information on Grey Literature in Europe until November 30th, 2019. The Newcastle-Ottawa (NOS) scale was used to assess the studiesâ quality. Review Manager 5.3 (provided by the Cochrane Collaboration) was used to synthesize the effects on airway dimensions.
Results After full text assessment, 8 studies were included in the qualitative and quantitative synthesis. NOS scores ranged 6 to 9 indicating high quality. The effects of two therapeutic protocols were compared, treatment with MPAs only (113 subjects treated - 65 controls) and the treatment with MPAs + RME (137 subjects treated-87 controls). The MPAs only treatment group displayed a significantly increase in nasopharyngeal airway dimension at PNS-AD1 (random: mean difference, 1.39 mm, 95% CI, 0.32 mm, 2.47 mm, p= 0.01) and at PNS-AD2 (random: mean difference, 1.70 mm, 95% CI, 1.14 mm, 2.26 mm, p= 0.00001). No statistically significant changes were found post treatment in MPAs + RME treatment groups at PNS-AD1 (P= 0.15), PNS-AD2 (P= 0.17), McNamaraâs upper pharynx (MPAs + RME P= 0.05, MPAs P= 0.99) and McNamara lower pharynx (MPAs + RME P= 0.25, MPAs P= 0.40).
Conclusion MPAs only treatment can increase the pharyngeal thickness after treatment both at PNS-A1 and PNS-AD2. MPA+ RME had no effect on sagittal widths compared with controls, but the effect on the transverse dimension could not be assessed
TREATMENT OF CLASS I MALOCCLUSION WITH FRANKEL APPLIANCE
Aim. The aim of this paper is to evaluate the effect of the Frankel in child with class I malocclusion,
maxillary and mandibular contraction, and anterior teeth crowding.
Materials and methods. 5 patients with a class I division I malocclusion, maxillary and mandibular
contraction and anterior crowding was enrolled in the present study. All patients presented with a stage
CS2, CS3 or CS4. Patients with CS5 were not enrolled in the study. Before wearing the Frankel, on each
patient head radiographs were taken in lateral plane with the head fixed in a cephalostat with a filmfocus
distance of 4 m and a midsagittal-to-film distance of 0,1 m. Cephalometric analysis and casts
analysis was performed before phase 1 treatment (T1), and immediately following phase 2 treatment
(T2). In addition to standard cephalometric evaluation, another analysis, based on the distance of the
basion, A and B to the T line, was done. Patients were instructed to wear the Frankel for 16 hours per day,
during the night and afternoon, removing it only to eat and brush. Active treatment lasted 24 months for
all patients. A statistical analysis of cephalometric and casts values before and after treatment was
done.Results. After 24 months of treatment the cephalometric effects observed were: an increase of the
anterior facial height (mean 3,8 mm), an increase of the distance of the basion to the T line (mean 3,6
mm), a incisors tip control (upper incisors mean 0°, lower incisors - 3,2°) and a sagittal maxillary growth
control (the mean distance of A to T line was 0°, the mean distance of B to T line was of - 2,2 mm). On
cast authors observed an expansion of the upper and lower arches (anterior upper arch expansion mean 2 mm, posterior upper arch expansion mean 2,5 mm; lower arch mean 1 mm) with anterior crowding resolution and incisors sagittal control.
Conclusions. Authors evaluated that Frankel had a great repeal to control jaw growth, an increase of
maxillary and mandibular expansion, an increase of the anterior facial height with a good control of incisors inclination
Working length transfer in the endodontic clinical practice: A comparative study
8The present paper evaluated the accuracy of two different methods for transferring working
length (WL) between manual endodontic instruments and nickelâtitanium (NiTi) shaping files.
Thirty root canals of extracted permanent teeth were used. Root canals were divided according to
canal length (CL) and canal curvature (CC). The reference cusp and the root end were flattened to
provide reproducible and accurate measurements. During shaping, the WL measurements were
obtained with manual k-files (KF) and transferred to WaveOne (W1) NiTi reciprocating files using
the traditional method with the endodontic ruler (method I) and an alternative clinical procedure
based on the comparison of the instruments side by side from tip to shank (method II). For each file
and each tested method, two measures were taken by two examiners using Rhino (ver. 4.0, McNeel,
Seattle, WA, USA) software for a total of 360 (30 Ă 3 Ă 2 Ă 2) measures. Analysis of variance was
performed by taking the difference in length (Delta WL, DWL) between files used for the same canal.
The difference between methods I and II for WL transfer was found to be statistically significant
(df = 1; F = 71.52; p < 0.001). The DWL absolute values obtained with method II were found to be
closer to 0 mm (i.e., same length as corresponding KF) than those obtained with method I. Both CL
(df = 2; F = 1.27; p = 0.300) and CC (df = 1; F = 2.22; p = 0.149) did not significantly influence WL
measurements. With respect to WL transfer, method II seemed to better preserve the correct WL
transfer between instruments during the clinical endodontic procedures.openopenMario Alovisi; Mario Dioguardi; Massimo Carossa; Giuseppe Troiano; Maria Chiara Domini; Davide Salvatore Paolino; Giorgio Chiandussi; Elio BeruttiAlovisi, Mario; Dioguardi, Mario; Carossa, Massimo; Troiano, Giuseppe; Chiara Domini, Maria; Paolino, DAVIDE SALVATORE; Chiandussi, Giorgio; Berutti, Eli
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