7,772 research outputs found
Clustering stock market companies via chaotic map synchronization
A pairwise clustering approach is applied to the analysis of the Dow Jones
index companies, in order to identify similar temporal behavior of the traded
stock prices. To this end, the chaotic map clustering algorithm is used, where
a map is associated to each company and the correlation coefficients of the
financial time series are associated to the coupling strengths between maps.
The simulation of a chaotic map dynamics gives rise to a natural partition of
the data, as companies belonging to the same industrial branch are often
grouped together. The identification of clusters of companies of a given stock
market index can be exploited in the portfolio optimization strategies.Comment: 12 pages, 3 figure
Hausdorff clustering of financial time series
A clustering procedure, based on the Hausdorff distance, is introduced and
tested on the financial time series of the Dow Jones Industrial Average (DJIA)
index.Comment: 9 pages, 3 figure
Monolithic zirconia and digital impression: case report
The aim of this study is to present a clinical case of a full arch prosthetic rehabilitation on natural teeth, combining both digital work-flow and monolithic zirconi
Aesthetic satisfaction in lip and palate clefts: a comparative study between secondary and tertiary bone grafting
Lip and palate cleft represent one of the most frequently occurring congenital deformity, which includes dental anomalies, such as variation in tooth number and position. In case of hypodontia implant-prosthetic rehabilitation offers significant advantages in terms of function, aesthetics and quality of life and bone graft is usually needed. Secondary bone grafting, generally performed in the mixed dentition phase (years 8-11) seems to be the most successful method to allow for rehabilitation. It's often necessary to perform a tertiary bone grafting in adult age in order to achieve better bone quantity and quality before implant placement. Aim of this retrospective study was to evaluate the aesthetic perception that patients had of themselves comparing dental implants placed in tertiary grafted alveolar cleft sites with a previous secondary grafting to only secondary grafting. Between 2009 and 2012, fourteen alveolar cleft were treated with implant rehabilitation and eleven of them received tertiary bone grafting six months prior to implant placement. All patients were questioned to give a score from 1 to 10 their aesthetic satisfaction of their smile before and after implant rehabilitation and during pre-surgery provisional rehabilitation. At the end of their prosthesis rehabilitation patients who received tertiary bone grafting resulted more satisfied than those who had secondary bone grafting only (9.5 vs 8)
Confocal laser scanning microscope, raman microscopy and western blotting to evaluate inflammatory response after myocardial infarction
Cardiac muscle necrosis is associated with inflammatory cascade that clears the infarct from dead
cells and matrix debris, and then replaces the damaged tissue with scar, through three overlapping phases: the
inflammatory phase, the proliferative phase and the maturation phase.
Western blotting, laser confocal microscopy, Raman microscopy are valuable tools for studying the inflammatory
response following myocardial infarction both humoral and cellular phase, allowing the identification and
semiquantitative analysis of proteins produced during the inflammatory cascade activation and the topographical distribution
and expression of proteins and cells involved in myocardial inflammation. Confocal laser scanning microscopy
(CLSM) is a relatively new technique for microscopic imaging, that allows greater resolution, optical sectioning of the
sample and three-dimensional reconstruction of the same sample. Western blotting used to detect the presence of a specific
protein with antibody-antigen interaction in the midst of a complex protein mixture extracted from cells, produced
semi-quantitative data quite easy to interpret. Confocal Raman microscopy combines the three-dimensional optical resolution
of confocal microscopy and the sensitivity to molecular vibrations, which characterizes Raman spectroscopy.
The combined use of western blotting and confocal microscope allows detecting the presence of proteins in the sample
and trying to observe the exact location within the tissue, or the topographical distribution of the same. Once demonstrated
the presence of proteins (cytokines, chemokines, etc.) is important to know the topographical distribution, obtaining in this
way additional information regarding the extension of the inflammatory process in function of the time stayed from the
time of myocardial infarction. These methods may be useful to study and define the expression of a wide range of inflammatory
mediators at several different timepoints providing a more detailed analysis of the time course of the infarct
Gingival hyperplasia around dental implants in jaws reconstructed with free vascularized flaps: a case report series
Free vascularized flaps are the gold standard for reconstruction of the facial skeleton after surgical ablation of pathologies or when important atrophy of the jaws exists. A frequent problem seen during prosthetic rehabilitation after reconstruction with free vascularized flaps is the onset of hyperplastic granulomatous reactive tissue around the prosthetic abutment of the implant. The features of this phenomenon seem to be directly related to the characteristics of the periimplant tissue and of the manufacturing materials of the prosthesis and abutments. This complication can be seen quite often; we found it in 7 of 40 patients (17.5%). It does not seem to significantly affect the survival rate of implants. The aim of the study was to analyze the behavior of such lesions and to suggest our clinical approach with the management of these kinds of patients and complications. To remove gingival hyperplasia, we used either a traditional cold scalpel or an electric cautery or laser. We had good results using these tools. The onset of this phenomenon was not influenced by either the kind of implant and free flaps used or by the local conditions of the patients (such as radiotherapy). The number of recurrences was highly influenced by the oral hygiene of the patients
Histological and immunohistochemical evaluation of mandibular bone tissue regeneration
The purpose of the study was to perform an immunohistochemical and histological evaluation of samples taken from different bone regeneration procedures in atrophic human mandible. 30 patients (15 men and 15 women, age range of 35-60 years), non-smokers, with good general and oral health were recruited in this study and divided into three groups. The first group included patients who were treated with blood Concentration Growth Factors (bCGF), the second group included patients who were treated with a mixture of bCGF and autologous bone, while the third group of patients was treated with bCGF and tricalcium phosphate/hydroxyapatite (TCP-HA). Six months after the regenerative procedures, all patients undergone implant surgery, and a bone biopsy was carried out in the site of implant insertion. Each sample was histologically and immunohistochemically examined. Histological evaluation showed a complete bone formation for group II, partial ossification for group I, and moderate ossification for group III. Immunohistochemical analysis demonstrated a statistically significant difference between the three groups, and the best clinical result was obtained with a mixture of bCGF and autologous bone
Finite size scaling of current fluctuations in the totally asymmetric exclusion process
We study the fluctuations of the current J(t) of the totally asymmetric
exclusion process with open boundaries. Using a density matrix renormalization
group approach, we calculate the cumulant generating function of the current.
This function can be interpreted as a free energy for an ensemble in which
histories are weighted by exp(-sJ(t)). We show that in this ensemble the model
has a first order space-time phase transition at s=0. We numerically determine
the finite size scaling of the cumulant generating function near this phase
transition, both in the non-equilibrium steady state and for large times.Comment: 18 pages, 11 figure
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