100 research outputs found

    Curvilinear coordinates for full-core atoms

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    Curvilinear coordinates, first introduced by F. Gygi for valence-only electronic systems within the local-density functional theory, can be used to describe both core and valence electrons in electronic-structure calculations. A simple and quite general coordinate transformation results in a large, yet affordable plane-wave energy cutoff for full-core systems (e.g., about 120 Ryd for carbon or silicon) within the local-density functional theory, and in a reduced correlation time for full-core variational Monte Carlo calculations. Numerical tests for isolated Li, C, and Si atoms are presented.Comment: 14 pages, 8 Postscript figures; acknowledgements and two refs. adde

    Clear aligners: between evolution and efficiency—a scoping review

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    In recent years, clear aligners have diversified and evolved in their primary characteristics (material, gingival margin design, attachments, divots, auxiliaries), increasing their indications and efficiency. We overviewed the brands of aligners used in Italy and reviewed the literature on the evolution of clear aligners based on their characteristics mentioned above by consulting the main scientific databases (PubMed, Scopus, Lilacs, Google Scholar, Cochrane Library). Inclusion and ex-clusion criteria were established. The data were collected on a purpose-made data collection form and analyzed descriptively. From the initial 580 records, 527 were excluded because they were not related to the subject of the review or because they did not meet the eligibility criteria. The remaining 31 studies were deemed comprehensive for the purpose of the review, although the “gingival margin design” feature and “auxiliaries” tool are not well represented in the more recent literature. Current knowledge on invisible aligners allows us to have a much clearer idea of the basic characteristics of aligner systems. There remains a need to deepen the use of systems other than In-visalign™ to give greater evidence to aligners that are very different based on the characteristics analyzed here and that are very widespread on the market

    Intraoral scanners in personal identification of corpses: usefulness and reliability of 3d technologies in modern forensic dentistry

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    Aims: This study aims to verify the applicability of modern dental technologies and their related principles of use to the forensic sciences in the field of personal identification. Background: Personal identification has always had a major role in many legal and administrative actions regarding both living and death beings. The techniques used are much less advanced than the technologies potentially available. Objective: Modern technologies, available to the daily dental clinic practice, as intraoral scanners, combined in particular to the specialist skill in orthodontics, can help redefine the methods of personal identification according to the levels of accuracy, trueness and feasibility greater than those applied in traditional forensic dentistry. Methods: 23 corpses (12F;11M) have been selected for intraoral scanning with the Carestream 3500® digital device. The superimposition of initial and late digital models, digital models and radiographs (orthopantomography and full mouth periapical films) has been evaluated to verify the stability of some structures as palatal rugae after death and to assess intraoral scanning as a successful comparative method between antemortem and postmortem records (digital models or radiographs). Obtained results were subjected to statistical analysis by the t-student test and X-square test with Yates correction (p<0.05). Results: After death, palatal rugae significatively change especially in mouths with restorations/prosthesis/missing teeth. The percentages of correct matching between scans and radiographs are very higher (up 90%; p<0.05). Conclusion: This study has been set up to study and develop new, reliable and fast methods of personal identification that can surpass many of the issues seen with the other techniques by a modern rugoscopy, a modern radiographic-digital comparison and virtual oral autopsy

    An efficient k.p method for calculation of total energy and electronic density of states

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    An efficient method for calculating the electronic structure in large systems with a fully converged BZ sampling is presented. The method is based on a k.p-like approximation developed in the framework of the density functional perturbation theory. The reliability and efficiency of the method are demostrated in test calculations on Ar and Si supercells

    Validation of PARADISE 24 and Development of PARADISE-EDEN 36 in Patients with Dementia

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    Dementia was one of the conditions focused on in an EU (European Union) project called “PARADISE” (Psychosocial fActors Relevant to brAin DISorders in Europe) that later produced a measure called PARADISE 24, developed within the biopsychosocial model proposed in the International Classification of Functioning Disability and Health (ICF). The aims of this study are to validate PARADISE 24 on a wider sample of patients with mild to moderate dementia to expand PARADISE 24 by defining a more specific scale for dementia, by adding 18 questions specifically selected for dementia, which eventually should be reduced to 12. We enrolled 123 persons with dementia, recruited between July 2017 and July 2019 in home care and long-term care facilities, in Italy, and 80 participants were recruited in Warsaw between January and July 2012 as part of a previous cross-sectional study. The interviews with the patient and/or family were conducted by health professionals alone or as a team by using the Paradise data collection protocol. The psychometric analysis with the Rasch analysis has shown that PARADISE 24 and the selection of 18 additional condition-specific items can be expected to have good measurement properties to assess the functional state in persons with dementia

    Seismic Vulnerability Assessment of Priority Cultural Heritage Structures in the Philippines

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    At the end of 2013 two catastrophic events occurred in the Philippines: the M 7.2 earthquake in Bohol and the strongest ever recorded Typhoon Haiyan, causing destruction across the islands of Cebu, Bohol and the Visayas region. These events raised the need to carry out a multi-hazard risk assessment of heritage buildings, many of which were irretrievably lost in the disasters. Philippines’ Department of Tourism engaged ARS Progetti S.P.A., Rome, Italy, and the Center for Conservation of Cultural Property and Environment in the Tropics (CCCPET), University of Sto. Tomas, Manila, to undertake the “Assessment of the Multi-Hazard Vulnerability of Priority Cultural Heritage Structures in the Philippines”, with experts from University College London, UK, and De La Salle University. The main objective of the project was to reduce the vulnerability of cultural heritage structures to multiple natural hazards, including earthquake, typhoon, flood, by: (i) prioritizing of specific structures based on hazard maps and historical records; (ii) assessing their vulnerability; and (iii) recommending options to mitigate the impacts on them. The paper presents the methodology introduced to determine the seismic risk these heritage buildings are exposed to. All the selected cultural heritage structures are under the jurisdiction of the National Museum Commission of Philippines and of the National Commission for Culture and Arts

    Photoelasticity of crystalline and amorphous silica from first principles

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    Based on density-functional perturbation theory we have computed from first principles the photoelastic tensor of few crystalline phases of silica at normal conditions and high pressure (quartz, α\alpha-cristobalite, β\beta-cristobalite) and of models of amorphous silica (containig up to 162 atoms), obtained by quenching from the melt in combined classical and Car-Parrinello molecular dynamics simulations. The computational framework has also been checked on the photoelastic tensor of crystalline silicon and MgO as prototypes of covalent and ionic systems. The agreement with available experimental data is good. A phenomenological model suitable to describe the photoelastic properties of different silica polymorphs is devised by fitting on the ab-initio data.Comment: ten figure
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