scholarly journals Immersive 3D Educational Contents: A Technical Note for Dental Educators

Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 178
Author(s):  
Sabira Barour ◽  
Raphaël Richert ◽  
François Virard ◽  
Claudine Wulfman ◽  
Régis Iozzino ◽  
...  
Keyword(s):  
Dental Education ◽  
Three Dimensional ◽  
Technical Note ◽  
Educational Activity ◽  
Second Step ◽  
Educational Inequalities ◽  
Intraoral Scanner ◽  
Collaborative Tools ◽  
Definition Of ◽  
Educational Contents

Three-dimensional files featuring patients’ geometry can be obtained through common tools in dental practice, such as an intraoral scanner (IOS) or Cone Beam Computed Tomography (CBCT). The use of 3D files in medical education is promoted, but only few methodologies were reported due to the lack of ease to use and accessible protocols for educators. The aim of this work was to present innovative and accessible methodologies to create 3D files in dental education. The first step requires the definition of the educational outcomes and the situations of interest. The second step relies on the use of IOS and CBCT to digitize the content. The last “post-treatment” steps involve free software for analysis of quality, re-meshing and simplifying the file in accordance with the desired educational activity. Several examples of educational activities using 3D files are illustrated in dental education and discussed. Three-dimensional files open up many accessible applications for a dental educator, but further investigations are required to develop collaborative tools and prevent educational inequalities between establishments.

Application of high-resolution field-emission LVSEM, backscatter imaging, immunogold staining to definition of the spatial distributions of two human neutrophil adherence receptors

1993 ◽  
Vol 51 ◽  
pp. 36-37
Author(s):  
Robert D. Nelson ◽  
Sharon R. Hasslen ◽  
Stanley L. Erlandsen
Keyword(s):  
Cell Surface ◽  
Surface Membrane ◽  
Three Dimensional ◽  
Human Neutrophils ◽  
Spatial Distributions ◽  
Immunogold Staining ◽  
Functional Control ◽  
Neutrophil Adherence ◽  
Definition Of ◽  
Mode Of Attachment

Receptors are commonly defined in terms of number per cell, affinity for ligand, chemical structure, mode of attachment to the cell surface, and mechanism of signal transduction. We propose to show that knowledge of spatial distribution of receptors on the cell surface can provide additional clues to their function and components of functional control.L-selectin and Mac-1 denote two receptor populations on the neutrophil surface that mediate neutrophil-endothelial cell adherence interactions and provide for targeting of neutrophil recruitment to sites of inflammation. We have studied the spatial distributions of these receptors using LVSEM and backscatter imaging of isolated human neutrophils stained with mouse anti-receptor (primary) antibody and goat anti-mouse (secondary) antibody conjugated to 12 nm colloidal gold. This combination of techniques provides for three-dimensional analysis of the expression of these receptors on different surface membrane domains of the neutrophil: the ruffles and microvilli that project from the cell surface, and the cell body between these projecting structures.

An innovative prone positioning system for advanced deformity and frailty in complex spine surgery

2020 ◽  
Vol 32 (2) ◽  
pp. 229-234
Author(s):  
Benjamin Kolb ◽  
John Large ◽  
Stuart Watson ◽  
Glyn Smurthwaite
Keyword(s):  
Ankylosing Spondylitis ◽  
Three Dimensional ◽  
Technical Note ◽  
Positioning System ◽  
Prone Positioning ◽  
Economic Implications ◽  
Potential Safety ◽  
Chest Deformity ◽  
Positioning Device ◽  
Skin Quality

The authors present a technical note for a prone positioning system developed to facilitate cervical extension osteotomy for ankylosing spondylitis in the presence of severe deformity and frailty. Chin-on-chest deformity represents one of the most debilitating changes of ankylosing spondylitis. Where the chin-brow angle approaches or exceeds 90°, prone positioning becomes problematic due to the fixed position of the head. Furthermore, the challenge is compounded where physiological deconditioning leads to frailty, and the side effects of medical therapies decrease muscle mass and skin quality. Conventional prone positioning equipment is not able to cater to all patients. A versatile system was developed using a 3D reconstruction to enable a positioning simulation and verification tool. The tool was used to comprehensively plan the perioperative episode, including spatial orientation and associated equipment. Three-dimensional printing was used to manufacture a bespoke positioning device that precisely matched the contours of the patient, reducing contact pressure and risk of skin injury. The authors were able to safely facilitate surgery for a patient whose deformity and frailty may otherwise have precluded this possibility. The system has potential safety and economic implications that may be of significant utility to other institutions engaging in complex spinal surgery.

scholarly journals Three-Dimensional Finite Element Analysis of Stress Distribution in a Tooth Restored with Full Coverage Machined Polymer Crown

2021 ◽  
Vol 11 (3) ◽  
pp. 1220
Author(s):  
Azeem Ul Yaqin Syed ◽  
Dinesh Rokaya ◽  
Shirin Shahrbaf ◽  
Nicolas Martin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Intraoral Scanner ◽  
Element Analysis ◽  
Dental Ceramic ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Ceramic Crown

The effect of a restored machined hybrid dental ceramic crown–tooth complex is not well understood. This study was conducted to determine the effect of the stress state of the machined hybrid dental ceramic crown using three-dimensional finite element analysis. Human premolars were prepared to receive full coverage crowns and restored with machined hybrid dental ceramic crowns using the resin cement. Then, the teeth were digitized using micro-computed tomography and the teeth were scanned with an optical intraoral scanner using an intraoral scanner. Three-dimensional digital models were generated using an interactive image processing software for the restored tooth complex. The generated models were imported into a finite element analysis software with all degrees of freedom concentrated on the outer surface of the root of the crown–tooth complex. To simulate average occlusal load subjected on a premolar a total load of 300 N was applied, 150 N at a buccal incline of the palatal cusp, and palatal incline of the buccal cusp. The von Mises stresses were calculated for the crown–tooth complex under simulated load application was determined. Three-dimensional finite element analysis showed that the stress distribution was more in the dentine and least in the cement. For the cement layer, the stresses were more concentrated on the buccal cusp tip. In dentine, stress was more on the cusp tips and coronal 1/3 of the root surface. The conventional crown preparation is a suitable option for machined polymer crowns with less stress distribution within the crown–tooth complex and can be a good aesthetic replacement in the posterior region. Enamic crowns are a good viable option in the posterior region.

scholarly journals Proposing 3D Thermal Technology for Heritage Building Energy Monitoring

2021 ◽  
Vol 13 (8) ◽  
pp. 1537
Author(s):  
Antonio Adán ◽  
Víctor Pérez ◽  
José-Luis Vivancos ◽  
Carolina Aparicio-Fernández ◽  
Samuel A. Prieto
Keyword(s):  
Computer Vision ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Building Energy ◽  
Energy Monitoring ◽  
3D Computer Vision ◽  
Building Monitoring ◽  
Heritage Buildings ◽  
Heritage Building ◽  
Definition Of

The energy monitoring of heritage buildings has, to date, been governed by methodologies and standards that have been defined in terms of sensors that record scalar magnitudes and that are placed in specific positions in the scene, thus recording only some of the values sampled in that space. In this paper, however, we present an alternative to the aforementioned technologies in the form of new sensors based on 3D computer vision that are able to record dense thermal information in a three-dimensional space. These thermal computer vision-based technologies (3D-TCV) entail a revision and updating of the current building energy monitoring methodologies. This paper provides a detailed definition of the most significant aspects of this new extended methodology and presents a case study showing the potential of 3D-TCV techniques and how they may complement current techniques. The results obtained lead us to believe that 3D computer vision can provide the field of building monitoring with a decisive boost, particularly in the case of heritage buildings.

scholarly journals Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keunbada Son ◽  
Young-Tak Son ◽  
Ji-Min Lee ◽  
Kyu-Bok Lee
Keyword(s):  
Three Dimensional ◽  
Clinical Situation ◽  
Intraoral Scanner ◽  
Replica Technique ◽  
Finish Line ◽  
Marginal Fit ◽  
Tooth Preparation ◽  
The Right ◽  
Internal Fit ◽  
Marginal Region

AbstractThis study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

Grammatik der Narration

2020 ◽  
Vol 48 (3) ◽  
pp. 457-494
Author(s):  
Sonja Zeman
Keyword(s):  
Narrative Discourse ◽  
Linguistic Theory ◽  
Second Step ◽  
Narrative Fiction ◽  
The Status ◽  
Definition Of ◽  
Narrative Syntax

AbstractIs there a ‚narrative syntax‘, i. e. a special grammar restricted to narrative fiction? Starting from this question which has been investigated since early structuralism, the paper focusses on grammatical characteristics of narrative discourse mode and their implications for a linguistic theory of narration. Its goal is two-fold: In a first step, the traditional accounts by Benveniste, Hamburger, Kuroda and recent typological studies are brought together in order to support the claim that the distinction between narrative and non-narrative discourse mode is a fundamental one that has consequences for the use of grammar. In a second step, I discuss three central questions within the intersection between narrative micro- and macro-structures, namely (i) the definition of narrativity, (ii) the status of the narrator, and (iii) the relation between narration and fictionality. In sum, the article argues that investigations on the ‘grammar of narration’ do not just offer insights into a specific text configuration next to others, but are deeply linked to fundamental theoretical questions concerning the architecture of language – and that the comparison between linguistic and narratological categories offers a potential for addressing them.

Anion packing density: a universal quantity for both dense and porous crystalline inorganic phases

2002 ◽  
Vol 58 (3) ◽  
pp. 457-462 ◽  
Author(s):  
F. Liebau ◽  
H. Küppers
Keyword(s):  
High Pressure ◽  
Packing Density ◽  
Three Dimensional ◽  
Ionic Radii ◽  
Generalized Framework ◽  
Molal Volumes ◽  
Definition Of ◽  
Anion Packing ◽  
Very High ◽  
Framework Density

To compare densities of inorganic high-pressure phases their molal volumes or specific gravities are usually employed, whereas for zeolites and other microporous materials the so-called framework density, FD, is applied. The definition of FD, which refers only to phases with three-dimensional tetrahedron frameworks, is extended to a `generalized framework density' d f, which is independent of the dimensionality of the framework and the coordination number(s) of the framework cations. In this paper the anion packing density, d ap, is introduced as a new quantity which is not only applicable to any inorganic phase but, in contrast to FD and d f, also allows quantitative comparisons to be made for crystalline inorganic phases of any kind. The anion packing density can readily be calculated if the volume and content of the unit cell and the radii of the anions of a phase are known. From d ap values calculated for high-pressure silica polymorphs studied under very high pressure, it is concluded that Shannon–Prewitt effective ionic radii do not sufficiently take into account the compressibility of the anions.

The Use of Photogrammetry in Piping Design

1983 ◽  
Vol 197 (2) ◽  
pp. 125-138 ◽  
Author(s):  
P A Bracewell ◽  
U R Klement
Keyword(s):  
Information Retrieval ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Cost Effective ◽  
Process Industry ◽  
Process Plant ◽  
Definition Of ◽  
High Degree ◽  
Positional Data

Piping design for ‘revamp’ projects in the process industry requires the retrieval of large amounts of ‘as-built’ data from existing process plant installations. Positional data with a high degree of accuracy are required. Photogrammetry, the science of measurement from photographs, was identified in Imperial Chemical Industries plc (ICI) as a suitable tool for information retrieval. The mathematical formulation enabling the definition of three-dimensional positions from photographic information is described. The process of using ICI's photogrammetric system for the definition of complete objects such as structures and pipes is illustrated. The need for specialized photogrammetric software for design purposes is explained. A case study describing how the photogrammetric system has been applied is described and graphical outputs from this exercise are shown. It is concluded that this particular photogrammetric system has proved to be a cost effective and accurate tool for the retrieval of ‘as-built’ information.

scholarly journals Three-dimensional quantification of twisting in the Arabidopsis petiole

2021 ◽  
Author(s):  
Yuta Otsuka ◽  
Hirokazu Tsukaya
Keyword(s):  
Cross Sections ◽  
Three Dimensional ◽  
Light Sheet ◽  
Underlying Mechanism ◽  
Two Dimensions ◽  
Observation Angle ◽  
Differential Growth ◽  
Light Sheet Microscopy ◽  
Definition Of ◽  
Twisting Angle

AbstractOrganisms have a variety of three-dimensional (3D) structures that change over time. These changes include twisting, which is 3D deformation that cannot happen in two dimensions. Twisting is linked to important adaptive functions of organs, such as adjusting the orientation of leaves and flowers in plants to align with environmental stimuli (e.g. light, gravity). Despite its importance, the underlying mechanism for twisting remains to be determined, partly because there is no rigorous method for quantifying the twisting of plant organs. Conventional studies have relied on approximate measurements of the twisting angle in 2D, with arbitrary choices of observation angle. Here, we present the first rigorous quantification of the 3D twisting angles of Arabidopsis petioles based on light sheet microscopy. Mathematical separation of bending and twisting with strict definition of petiole cross-sections were implemented; differences in the spatial distribution of bending and twisting were detected via the quantification of angles along the petiole. Based on the measured values, we discuss that minute degrees of differential growth can result in pronounced twisting in petioles.

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