236 research outputs found
Diagnosis and management of benign fibro-osseous lesions of the jaws: a current review for the dental clinician
Benign fibro-osseous lesions of the maxillofacial skeleton constitute a heterogeneous group of disorders that includes developmental, reactive (dysplastic) and neoplastic lesions. Although their classification has been reviewed multiple times in the past, the most common benign fibro-osseous lesions are fibrous dysplasia, osseous dysplasia and ossifying fibroma. For the dental clinician, the challenges involve diagnosis and treatment (or lack thereof). A careful correlation of all clinical, radiologic and microscopic features is essential to establish a proper diagnosis and a clear treatment plan. This article aimed to review the clinical, radiologic and histopathologic characteristics of benign fibro-osseous lesions of the jaws, with emphasis on their differential diagnoses. With a deeper understanding of benign fibro-osseous lesions, clinicians will be better prepared to manage these lesions in their practice
Oral pyoderma gangrenosum: diagnosis, treatment and challenges: a systematic review
Pyoderma gangrenosum (PG) is a distinctive ulcerative skin disorder of unknown etiology, associated with
an underlying systemic disease in up to 70% of cases. The condition is characterized by the appearance of one or more
necrotic ulcers with a ragged undermined violaceous border and surrounding erythema. Lesions are often initiated by
minor trauma. The condition can affect any anatomical site, however the head and neck are rarely involved. Although
the oral cavity is subject to recurrent minor trauma through everyday activities such as mastication and oral hygiene,
as well as during dental treatment, oral lesions appear to be extremely rare. In an effort to provide a detailed
explanation of the oral manifestations of PG, a systematic search was conducted using medical databases. A total of
20 cases of PG with oral involvement were reported in the English and French literature. The objectives of this article
are to present the pertinent diagnostic criteria and to discuss the differential diagnosis and therapeutic modalities
How to compute the thermodynamics of a glass using a cloned liquid
The recently proposed strategy for studying the equilibrium thermodynamics of
the glass phase using a molecular liquid is reviewed and tested in details on
the solvable case of the -spin model. We derive the general phase diagram,
and confirm the validity of this procedure. We point out the efficacy of a
system of two weakly coupled copies in order to identify the glass transition,
and the necessity to study a system with copies ('clones') of the
original problem in order to derive the thermodynamic properties of the glass
phase.Comment: Latex, 17 pages, 6 figure
The Fully Frustrated Hypercubic Model is Glassy and Aging at Large
We discuss the behavior of the fully frustrated hypercubic cell in the
infinite dimensional mean-field limit. In the Ising case the system undergoes a
glass transition, well described by the random orthogonal model. Under the
glass temperature aging effects show clearly. In the case there is no sign
of a phase transition, and the system is always a paramagnet.Comment: Figures added in uufiles format, and epsf include
Optical activity in the Drude helix model
An old classical one-particle helix model for optical activity, first
proposed by Drude, is reconsidered here. The quantum Drude model is very
instructive because the optical activity can be calculated analytically without
further approximations apart from the Rosenfeld long wavelength approximation.
While it was generally believed that this model, when treated correctly, is
optically inactive, we show that it leads to optical activity when the motion
of the particle is quantum mechanically treated. We also find that optical
activity arises even in the classical regime at non-zero energy, while for zero
energy the model is inactive, in accordance with previous results. The model is
compared with other one-electron models and it is shown that its predicted
optical activity is qualitatively different from those of other one-electron
systems. The vanishing of optical activity in the classical zero-energy limit
for the Drude model is due to the localization of the particle at the
equilibrium position, whereas in the analogous model of a particle moving
freely on a helix without a definite equilibrium position, optical activity
does not vanish but the spectrum is rescaled. The model under study leads to
interesting predictions about the optical properties of e. g. helicene
derivatives
Statistical Physics of the Glass Phase
This paper gives an introduction to some of the statistical physics problems
which appear in the study of structural glasses. It is a shortened and updated
version of a more detailed review paper which has appeared in cond-mat/0005173.Comment: 10 pages, 4 figures, Proceedings of Statphys 2
Stripe glasses: self generated randomness in a uniformly frustrated system
We show that a system with competing interactions on different length scales,
as relevant for the formation of stripes in doped Mott insulators, undergoes a
self-generated glass transition which is caused by the frustrated nature of the
interactions and not related to the presence of quenched disorder. An
exponentially large number of metastable configurations is found, leading to a
slow, landscape dominated long time relaxation and a break up of the system
into a disordered inhomogeneous state.Comment: 5 pages, 2 figure
Statistical Physics of Structural Glasses
This paper gives an introduction and brief overview of some of our recent
work on the equilibrium thermodynamics of glasses. We have focused onto first
principle computations in simple fragile glasses, starting from the two body
interatomic potential. A replica formulation translates this problem into that
of a gas of interacting molecules, each molecule being built of atoms, and
having a gyration radius (related to the cage size) which vanishes at zero
temperature. We use a small cage expansion, valid at low temperatures, which
allows to compute the cage size, the specific heat (which follows the Dulong
and Petit law), and the configurational entropy. The no-replica interpretation
of the computations is also briefly described. The results, particularly those
concerning the Kauzmann tempaerature and the configurational entropy, are
compared to recent numerical simulations.Comment: 21 pages, 6 figures, to appear in the proceedings of the Trieste
workshop on "Unifying Concepts in Glass Physics
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