2,332 research outputs found
Definizione, acquisizione sperimentale ed elaborazione di traiettorie di riferimento della mano umana per la sintesi di architetture protesiche di arto superiore
This paper reports an essential part of a wider research activity, which entails the development of a procedure for the Determination of the Optimal Prosthesis Architecture (DOPA) for a given upper limb amputee. A fundamental algorithm of the DOPA procedure performs the kinematic analysis of several prosthetic arm models (also with less than the six degrees of freedom normally required to correctly execute a generic manipulation task). The algorithm must simulate the execution of important daily living activities performed by a prosthesis and thus it requires reference trajectories of the hand. By means of experimental analysis, 59 trajectories of the hand of an able-bodied subject were acquired to identify a modality to correctly perform the corresponding tasks. This paper illustrates in detail the stages of task analysis, experimental acquisition and data processing in order to define the required reference trajectories. The obtained reference trajectories are a temporal succession of the hand pose (position and orientation). A customized algorithm automatically selects the most relevant poses to be considered for the definition of the reference trajectory. The hand pose is reported in the Cartesian Space by means of Natural Coordinates. In order to correctly execute a given task the pose error admitted for the end-effector of the different architectures is associated to each trajectory. In particular, the critical problem to express the orientation error is solved by means of the use of Spherical Rotation Coordinates
Patients’ self-perception of dentofacial attractiveness before and after exposure to facial photographs
open4noObjective: To determine whether exposure to pretreatment photographs of themselves influenced patients’ self-perception of dentofacial attractiveness and willingness to undergo treatment.
Materials and Methods: A total of 100 subjects of white ancestry aged 18 years or older (Study Group) and 100 sex- and age-matched controls (Control Group) were selected. Photographs of the frontal view of the face and the profile view of the face, both at rest and while smiling, were taken of
each participant. Only Study Group subjects were given a printed copy of their own images to be examined at home between the initial observation (T0) and a set date an average of 30 days later (T1). Each of the 200 subjects in the study completed a questionnaire at T0 and T1 exploring
happiness regarding their smiles and their facial profiles, as well as willingness to undergo treatment.
Results: At T1 in the Study Group, 50% of subjects responded with a lower opinion of their facial
profiles than at T0; 11% and 45% were willing to undergo more comprehensive procedures to change the appearance of their smiles and profiles, respectively. No statistically significant change was seen in questionnaire answers between T0 and T1 for the Control Group.
Conclusion: Laypeople generally are not aware of their facial profiles. Pretreatment photograph exposure can increase profile self-awareness, an important factor in reducing the discrepancy between orthodontists’ and patients’ visual emphasis on dentofacial esthetics.openGiulio Alessandri Bonetti; Andrea Alberti; Claudio Sartini; Serena Incerti ParentiGiulio Alessandri Bonetti; Andrea Alberti; Claudio Sartini; Serena Incerti Parent
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The role of inflammation, gut permeability and body weight in asthma: from molecular to human prebiotic interventions
Asthma is an inflammatory disease of the airways affecting 5.4 million people in the UK. Furthermore, obesity increases the risk of developing asthma is associated with worse symptoms and less response to medication. Both asthma and obesity are characterised by increased systemic inflammation that may be exacerbated by poor gut barrier integrity. Increased gut permeability allows endotoxin such as lipopolysaccharide (LPS) to translocate into the blood stream further increasing inflammation and indirectly exacerbating asthma symptoms. Common strategies to treat asthma are limited to targeting symptoms, rather than of the underlying inflammation. Novel strategies that may help ameliorate inflammation are short chain fatty acids (SCFA), end-products of gut bacteria fermentation of dietary substrates such as prebiotics, which appear to have anti-inflammatory properties and provide benefit at molecular and systemic level.
Therefore, a series of studies have been conducted to evaluate whether SCFA (acetate, butyrate, propionate) can mitigate LPS associated damage in organelles that leads to inflammation (mitochondria) at cellular level. Then, a human prebiotic intervention trial, which could indirectly increase circulating SCFAs level, was conducted to explore whether nutritional supplementation could be effective in reducing asthma symptoms and inflammatory, metabolic and permeability markers. Moreover, the effect of obesity and gut permeability on asthma severity was evaluated in cohorts of patients across asthma disease severity. Finally, to support future disease diagnosis a pilot study was conducted to explore difference in metabolic profiling between patients with and without asthma.
The outcome of these studies demonstrates that SCFA limit LPS induced damage in airway cells. The administration of prebiotics in adults with well-controlled asthma revealed a potential improvement in markers of metabolic health and inflammation. Furthermore, patients with obesity and asthma exhibit greater gut permeability which may represent a contributing factor to disease severity. Finally, through a metabolomic pilot study this thesis has revealed a potential metabolite profile that contributes to cluster separation between asthma and healthy controls.
Taken together the data suggested that increasing circulating SCFA via administration of prebiotic may provide an adjunctive tool to reduce inflammatory and metabolic damage at cellular level and in patients with asthma. Moreover, evaluation of the impact of obesity and gut permeability in asthma suggested that a broader range of approaches are needed to better characterize the pathophysiology of disease and improve future diagnosis and treatment
New spatial mechanisms for the kinematic analysis of the tibiotalar joint
In virtually unloaded conditions, the tibiotalar (ankle) joint behaves as a single degree-of-freedom system, and two fibres within the calcaneal-fibular and tibio-calcaneal ligaments remain nearly isometric throughout the flexion arc. A relevant theoretical model also showed that three articular surfaces and two ligaments act together as a mechanism to control the passive kinematics. Two equivalent spatial parallel mechanisms were formulated, with ligament fibres assumed isometric and articulating surfaces assumed rigid, either as three sphere-plane contacts, or as a single spherical pair. Predicted and measured motion in three specimens compared fairly well. Important enhancement of this previous work is here presented, with more accurate experimental data, more anatomical model surfaces, and a more robust mathematical model
Improved models of upper-level wind for several astronomical observatories
An understanding of wind speed and direction as a function of height are
critical to the proper modeling of atmospheric turbulence. We have used
radiosonde data from launch sites near significant astronomical observatories
and created mean profiles of wind speed and direction and have also computed
Richardson number profiles. Using data from the last 30 years, we extend the
1977 Greenwood wind profile to include parameters that show seasonal variations
and differences in location. The added information from our models is useful
for the design of adaptive optics systems and other imaging systems. Our
analysis of the Richardson number suggests that persistent turbulent layers may
be inferred when low values are present in our long term averaged data.
Knowledge of the presence of these layers may help with planning for adaptive
optics and laser communications.Comment: 21 pages, 15 Figures, 8 table
use of the electronic nose on products of cinta senese pigs
The use of a quartz microbalance based (QMB) electronic nose for feed traceability of fresh and cured fat of Cinta Senese pigs has been evaluated. Thirty-three pigs were fed different feeding during fattening: "three months chestnut" (3-CH), "1 month chestnut" (1-CH) "fed commercial feedstuff" (0-CH). Fresh fat and cured lard of each animal were analysed. Overall data set was analysed by factorial analysis to test if the instruments allowed a satisfactory pattern separation among groups. Afterwards, on the three factors generated by factorial analysis, a GLM procedure was applied to estimate effects such as: feeding type, operative temperature, day of analysis, order within day, layer of the subcutaneous fat. The results showed a clear separation according to feeding regimen in fresh fat only, especially between 1-CH and 0-CH, but also a strong effect of the other sources of variability. Concerning this, the date of analysis had a significant effect on each factor generated by factorial analysis that invalidated the discrimination obtained
Electron density in the quiet solar coronal transition region from SoHO/SUMER measurements of S VI line radiance and opacity
Context: The sharp temperature and density gradients in the coronal
transition region are a challenge for models and observations.
Aims: We set out to get linearly- and quadratically-weighted average electron
densities in the region emitting the S VI lines, using the observed opacity and
the emission measure of these lines.
Methods: We analyze SoHO/SUMER spectroscopic observations of the S VI lines,
using the center-to-limb variations and radiance ratios to derive the opacity.
We also use the Emission Measure derived from radiance at disk center.
Results: We get an opacity at S VI line center of the order of 0.05. The
resulting average electron density is 2.4 10^16 m^-3 at T = 2 10^5 K. This
value is higher than the values obtained from radiance measurements.
Conversely, taking a classical value for the density leads to a too high value
of the thickness of the emitting layer.
Conclusions: The pressure derived from the Emission Measure method compares
well with previous determinations and implies a low opacity of 5 10^-3 to
10^-2. The fact that a direct derivation leads to a much higher opacity remains
unexplained, despite tentative modeling of observational biases. Further
measurements need to be done, and more realistic models of the transition
region need to be used.Comment: 11 pages, 9 figure
Geomorphology of the seafloor north east of the Maltese Islands, Central Mediterranean
This paper presents a geomorphological map of the seafloor north east of the Maltese Islands (Central Mediterranean) at a scale of 1:50,000. The map was compiled following the integration, analysis and interpretation of several high-resolution seafloor bathymetry datasets. Several structural features, coastal and marine landforms and anthropogenic features have been mapped. Most of the mapped submerged landforms–including fluvial, gravity-induced and karst landforms–appear to have been formed during the sea-level lowstand of the last glacial cycle. The map provides valuable insights on the submerged landscape of the Maltese Islands and its evolution since the Last Glacial Maximum
The IkB kinase inhibitor nuclear factor-kB essential modulator–binding domain peptide for inhibition of balloon injury-induced neointimal formation
Objective—The activation of nuclear factor-kB (NF-kB) is a crucial step in the arterial wall’s response to injury. The
identification and characterization of the NF-kB essential modulator– binding domain (NBD) peptide, which can block
the activation of the IkB kinase complex, have provided an opportunity to selectively abrogate the inflammation-induced
activation of NF-kB. The aim of the present study was to evaluate the effect of the NBD peptide on neointimal
formation.<br></br>
Methods and Results—In the rat carotid artery balloon angioplasty model, local treatment with the NBD peptide (300
microg/site) significantly reduced the number of proliferating cells at day 7 (by 40%; P<0.01) and reduced injury-induced neointimal formation (by 50%; P<0.001) at day 14. These effects were associated with a significant reduction of NF-kB activation and monocyte chemotactic protein-1 expression in the carotid arteries of rats treated with the peptide. In addition, the NBD peptide (0.01 to 1 micromol/L) reduced rat smooth muscle cell proliferation, migration, and invasion in
vitro. Similar results were observed in apolipoprotein E-/-, mice in which the NBD peptide (150 microg/site) reduced wire-induced neointimal formation at day 28 (by 47%; P<0.01).<br></br>
Conclusion—The NBD peptide reduces neointimal formation and smooth muscle cell proliferation/migration, both effects
associated with the inhibition of NF-kB activation
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