7,218 research outputs found
Functional implications of minor mandibular asymmetry: clinical and digital research on a sample of healthy patients
OBJECTIVE.The aim of the study is to evaluate the influence that the mandibular asymmetry could have towards the other components of the Stomathognatic system and to further related structures from a functional point of view. MATERIALS and METHODS. A sample of 18 young asymmetric patients, in healthy status, was investigated with clinical evaluation and questionnaires and digital devices such as Electromiography, Stabilometry, T-scan and Formetric. Descriptive and quantitative statistical analysis were performed. RESULTS. ASIM electromyography index was significant only in a short percentage of the sample. Hypertonia of temporalis muscle in the same side of mandibular deviation and the cross-activation of the contralateral masseter were present. The data of the stabilometric platform showed that only 33% of patients had a load discrepancy between right and left side. All patients presented similar and limited postural anomalies during the Formetric examination. No significant results emerged from statistics . CONCLUSIONS. From the emerging data, mandibular asymmetry does not seem to be considered a potential risk factor for the development of functional anomalies both in the stomatognatic system and in the postural one. The only issue that should be considered is the condylar retrusion of the mandibular shortest side that is a possible destabilizing factor of the TMJ condyle-disc coordination
Functional implications of minor mandibular asymmetry: clinical and digital research on a sample of healthy patients
OBJECTIVE.The aim of the study is to evaluate the influence that the mandibular asymmetry could have towards the other components of the Stomathognatic system and to further related structures from a functional point of view. MATERIALS and METHODS. A sample of 18 young asymmetric patients, in healthy status, was investigated with clinical evaluation and questionnaires and digital devices such as Electromiography, Stabilometry, T-scan and Formetric. Descriptive and quantitative statistical analysis were performed. RESULTS. ASIM electromyography index was significant only in a short percentage of the sample. Hypertonia of temporalis muscle in the same side of mandibular deviation and the cross-activation of the contralateral masseter were present. The data of the stabilometric platform showed that only 33% of patients had a load discrepancy between right and left side. All patients presented similar and limited postural anomalies during the Formetric examination. No significant results emerged from statistics . CONCLUSIONS. From the emerging data, mandibular asymmetry does not seem to be considered a potential risk factor for the development of functional anomalies both in the stomatognatic system and in the postural one. The only issue that should be considered is the condylar retrusion of the mandibular shortest side that is a possible destabilizing factor of the TMJ condyle-disc coordination
COMPUTER AIDED RESTORATION TOOLS TO ASSIST THE CONSERVATION OF AN ANCIENT SCULPTURE. THE COLOSSAL STATUE OF ZEUS ENTHRONED
The research focuses on the contribution of the integrated application of Computer Aided Restoration digital procedures as a means to guide the integration measure of an artifact, innovating and implementing the traditional investigation methods. The aim of the study was to provide effective geometrical-formal investigation tools in the frame of the conservation work of Zeus enthroned from Soluntum, conserved in the Archaeological Museum \u201cA. Salinas\u201d of Palermo. The paper describes the workflow of the 3D acquisition and graphical modeling with non-invasive digitalization and high information density techniques to assist the conservation of the legs of the throne, especially the integration of the missing part. Thanks to the technique of the digital fabrication it has been reconstruct the two missing parts following the theoretical criteria as: recognisability, compatibility and retractability. This innovative application of 3D digital technologies have showed as the integrated use of the new technology can be a useful tools for improving the conservation of a work of art
The finite element method for the mechanically-based model of non-local continuum
In this paper the finite element method (FEM) for the mechanically based non-local elastic continuum model is proposed. In such a model each volume element of the domain is considered mutually interacting with the others, beside classical interactions involved by the Cauchy stress field, by means of central body forces that are monotonically decreasing with their inter-distance and proportional to the product of the interacting volume elements. The constitutive relations of the long-range interactions involve the product of the relative displacement of the centroids of volume elements by a proper, distance-decaying function, which accounts for the decrement of the long-range interactions as long as distance increases. In this study, the elastic problem involving long-range central interactions for isotropic elastic continuum will be solved with the aid of the FEM. The accuracy of the solution obtained with the proposed FEM code is compared with other solutions obtained with Galerkins' approximation as well as with finite difference method. Moreover, a parametric study regarding the effect of the material length scale in the mechanically based model and in the Kr"oner-Eringen non-local elasticity has been investigated for a plane elasticity proble
Stationary and non-stationary stochastic response of linear fractional viscoelastic systems
A method is presented to compute the stochastic response of single-degree-of-freedom (SDOF) structural
systems with fractional derivative damping, subjected to stationary and non-stationary inputs. Based on
a few manipulations involving an appropriate change of variable and a discretization of the fractional
derivative operator, the equation of motion is reverted to a set of coupled linear equations involving
additional degrees of freedom, the number of which depends on the discretization of the fractional
derivative operator. As a result of the proposed variable transformation and discretization, the stochastic
analysis becomes very straightforward and simple since, based on standard rules of stochastic calculus,
it is possible to handle a system featuring Markov response processes of first order and not of infinite
order like the original one. Specifically, for inputs of most relevant engineering interest, it is seen that
the response second-order statistics can be readily obtained in a closed form, to be implemented in any
symbolic package. The method applies for fractional damping of arbitrary order α (0 ≤ α ≤ 1). The
results are compared to Monte Carlo simulation data
Non-local stiffness and damping models for shear-deformable beams
This paper presents the dynamics of a non-local Timoshenko beam. The key assumption involves modeling non-local effects as long-range volume forces and moments mutually exerted by non-adjacent beam segments, that contribute to the equilibrium of any beam segment along with the classical local stress resultants. Elastic and viscous long-range volume forces/moments are endowed in the model. They are built as linearly depending on the product of the volumes of the interacting beam segments and on generalized measures of their relative motion, based on the pure deformation modes of the beam. Attenuation functions governing the space decay of the non-local effects are introduced. Numerical results are presented for a variety of non-local parameter
Image Based Modeling Technique for Pavement Distress surveys: a Specific Application to Rutting
Image-based modeling (IBM) is a well-known
technique to obtain high quality 3D models based on multi view
images. IBM started being used in several applications such as
inspection, identification of objects and visualization, due to the
user-friendly approach, the low cost and highly automated
technique.
This paper focuses on the investigation of the potential
application of IBM in the diagnosis of road pavement distresses
and in particular rutting. Indeed, the evaluation of the rutting
distress is a fundamental step to define the whole state of a
pavement as demonstrated by the calculation of Present
Serviceability Index (PSI). Currently, the permanent
deformation is measured monitoring visually the rut depth with
the approximations that this procedure involves. Nevertheless,
the exact measure of the rut depth is necessary to evaluate
precisely the cause and the severity of this distress and be
effective in the maintenance and rehabilitation of the pavement
structure.
The objective of this study is to apply the IBM technique on a
laboratory rutted sample, in order to verify the accuracy of the
method in determining the rut depth. To achieve this, a
comparison has been made between the 3D model obtained with
IBM and the one obtained with blue led 3D scan (Artec Spider)
of the same rutted asphalt concrete. The metric accuracy of the
model is then defined and its validity is assessed, in terms of
distress diagnosis
GALNT2 as a novel modulator of adipogenesis and adipocyte insulin signaling
Background/objectives: A better understanding of adipose tissue biology is crucial to tackle insulin resistance and eventually coronary heart disease and diabetes, leading causes of morbidity and mortality worldwide. GALNT2, a GalNAc-transferase, positively modulates insulin signaling in human liver cells by down-regulating ENPP1, an insulin signaling inhibitor. GALNT2 expression is increased in adipose tissue of obese as compared to that of non-obese individuals. Whether this association is secondary to a GALNT2-insulin sensitizing effect exerted also in adipocytes is unknown. We then investigated in mouse 3T3-L1 adipocytes the GALNT2 effect on adipogenesis, insulin signaling and expression levels of both Enpp1 and 72 adipogenesis-related genes. Methods: Stable over-expressing GALNT2 and GFP preadipocytes (T 0 ) were generated. Adipogenesis was induced with (R+) or without (R−) rosiglitazone and investigated after 15 days (T 15 ). Lipid accumulation (by Oil Red-O staining) and intracellular triglycerides (by fluorimetric assay) were measured. Lipid droplets (LD) measures were analyzed at confocal microscope. Gene expression was assessed by RT-PCR and insulin-induced insulin receptor (IR), IRS1, JNK and AKT phosphorylation by Western blot. Results: Lipid accumulation, triglycerides and LD measures progressively increased from T 0 to T 15 R- and furthermore to T 15 R+. Such increases were significantly higher in GALNT2 than in GFP cells so that, as compared to T 15 R+GFP, T 15 R- GALNT2 cells showed similar (intracellular lipid and triglycerides accumulation) or even higher (LD measures, p < 0.01) values. In GALNT2 preadipocytes, insulin-induced IR, IRS1 and AKT activation was higher than that in GFP cells. GALNT2 effect was totally abolished during adipocyte maturation and completely reversed at late stage maturation. Such GALNT2 effect trajectory was paralleled by coordinated changes in the expression of Enpp1 and adipocyte-maturation key genes. Conclusions: GALNT2 is a novel modulator of adipogenesis and related cellular phenotypes, thus becoming a potential target for tackling the obesity epidemics and its devastating sequelae
Effect of titanium dioxide crystalline structure on the photocatalytic production of hydrogen
The effect of the crystalline phase of TiO 2 (anatase, rutile and brookite) on its photocatalytic activity in hydrogen production from methanol-water vapours has been investigated by testing a series of both home-made and commercial TiO 2 photocatalysts, either bare or surface-modified by deposition of a fixed amount, i.e. 1 wt%, of platinum as co-catalyst. For all of the TiO 2 samples the rate of hydrogen production increased by one order of magnitude upon Pt deposition, because of the ability of Pt to enhance the separation of photoproduced electron-hole pairs. Under irradiation in the 350-450 nm wavelength range, brookite and anatase showed similar photoactivities, both superior to that of rutile. By contrast, rutile, possessing a narrower band gap, was active also under visible light (λ > 400 nm), whereas no hydrogen evolution was observed with anatase and brookite under such conditions. Surface area proved to be a key parameter, strongly influencing photoactivity. However, as the particle size became ultra-small, the semiconductor absorption edge was blue-shifted because of size quantisation effects, with a consequent decrease in hydrogen production rate due to the smaller portion of incident photons absorbed by the photocatalyst. © The Royal Society of Chemistry and Owner Societies 2011
Aqueye+: a new ultrafast single photon counter for optical high time resolution astrophysics
Aqueye+ is a new ultrafast optical single photon counter, based on single
photon avalanche photodiodes (SPAD) and a 4-fold split-pupil concept. It is a
completely revisited version of its predecessor, Aqueye, successfully mounted
at the 182 cm Copernicus telescope in Asiago. Here we will present the new
technological features implemented on Aqueye+, namely a state of the art timing
system, a dedicated and optimized optical train, a high sensitivity and high
frame rate field camera and remote control, which will give Aqueye plus much
superior performances with respect to its predecessor, unparalleled by any
other existing fast photometer. The instrument will host also an optical
vorticity module to achieve high performance astronomical coronography and a
real time acquisition of atmospheric seeing unit. The present paper describes
the instrument and its first performances.Comment: Proceedings of the SPIE, Volume 9504, id. 95040C 14 pp. (2015
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