scholarly journals A quasi-3D model of the whole lung: airway extension to the tracheobronchial limit using the constrained constructive optimization and alveolar modeling, using a sac–trumpet model

2021 ◽  
Author(s):  
Ravishekar (Ravi) Kannan ◽  
Narender Singh ◽  
Andrzej Przekwas ◽  
Xianlian Alex Zhou ◽  
Ross Walenga ◽  
...  
Keyword(s):  
Drug Transport ◽  
Computational Models ◽  
Three Dimensional ◽  
Ct Scans ◽  
Surface Geometry ◽  
Upper Airways ◽  
Surface Areas ◽  
Starting Point ◽  
Residual Capacity ◽  
The Individual

Abstract Existing computational models used for simulating the flow and species transport in the human airways are zero-dimensional (0D) compartmental, three-dimensional (3D) computational fluid dynamics (CFD), or the recently developed quasi-3D (Q3D) models. Unlike compartmental models, the full CFD and Q3D models are physiologically and anatomically consistent in the mouth and the upper airways, since the starting point of these models is the mouth–lung surface geometry, typically created from computed tomography (CT) scans. However, the current resolution of CT scans limits the airway detection between the 3rd–4th and 7th–9th generations. Consequently, CFD and the Q3D models developed using these scans are generally limited to these generations. In this study, we developed a method to extend the conducting airways from the end of the truncated Q3D lung to the tracheobronchial (TB) limit. We grew the lung generations within the closed lung lobes using the modified constrained constructive optimization, creating an aerodynamically optimized network aiming to produce equal pressure at the distal ends of the terminal segments. This resulted in a TB volume and lateral area of ∼165 cc and ∼2000 cm2, respectively. We created a “sac–trumpet” model at each of the TB outlets to represent the alveoli. The volumes of the airways and the individual alveolar generations match the anatomical values by design: with the functional residual capacity at 2611 cc. Lateral surface areas were scaled to match the physiological values. These generated Q3D whole lung models can be efficiently used for conducting multiple breathing cycles of drug transport and deposition simulations.

Dimensional Quantification of Embedded Voids or Objects in Three Dimensions Using X-Ray Tomography

2012 ◽  
Vol 18 (2) ◽  
pp. 390-398 ◽  
Author(s):  
Brian M. Patterson ◽  
Juan P. Escobedo-Diaz ◽  
Darcie Dennis-Koller ◽  
Ellen Cerreta
Keyword(s):  
Digital Imaging ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Post Processing ◽  
X Ray ◽  
Individual Object ◽  
Starting Point ◽  
X Ray Computed ◽  
The Individual ◽  
Processing Steps

AbstractScientific digital imaging in three dimensions such as when using X-ray computed tomography offers a variety of ways to obtain, filter, and quantify data that can produce vastly different results. These opportunities, performed during image acquisition or during the data processing, can include filtering, cropping, and setting thresholds. Quantifying features in these images can be greatly affected by how the above operations are performed. For example, during binarization, setting the threshold too low or too high can change the number of objects as well as their measured diameter. Here, two facets of three-dimensional quantification are explored. The first will focus on investigating the question of how many voxels are needed within an object to have accurate geometric statistics that are due to the properties of the object and not an artifact of too few voxels. These statistics include but are not limited to percent of total volume, volume of the individual object, Feret shape, and surface area. Using simple cylinders as a starting point, various techniques for smoothing, filtering, and other processing steps can be investigated to aid in determining if they are appropriate for a specific desired statistic for a real dataset. The second area of investigation is the influence of post-processing, particularly segmentation, on measuring the damage statistics in high purity Cu. The most important parts of the pathways of processing are highlighted.

Synthesis of Polyacetylene-like Modified Graphene Oxide Aerogel and Its Enhanced Electrical Properties

2019 ◽  
Author(s):  
Enrico Greco ◽  
Jing Shang ◽  
jiali zhu ◽  
Tong Zhu
Keyword(s):  
Graphene Oxide ◽  
Three Dimensional ◽  
Single Layer ◽  
Internal Surface ◽  
Solid Material ◽  
Single Layer Graphene ◽  
Covalent Bonds ◽  
Surface Areas ◽  
Modified Graphene Oxide ◽  
The Individual

<p>A graphene-based or carbon-based aerogel is a three-dimensional (3D) solid material in which the carbon atoms are arranged in a sheet-like nanostructure. In this study, we report the synthesis of low-density polymer-modified aerogel monoliths by 3D macro-assemblies of graphene oxide sheets that exhibit significant internal surface areas (982 m<sup>2</sup>/g) and high electrical conductivity (∼0.1 to 1 × 10<sup>2</sup> S/cm). Different types of materials were prepared to obtain a single monolithic solid starting from a suspension of single-layer graphene oxide (GO) sheets, and a polymer, made from the precursors 4-carboxybenzaldehyde and polyvinyl alcohol. These materials were used to cross-link the individual sheets by covalent bonds, resulting in wet-gels that were supercritically dried and then, in some cases, thermally reduced to yield graphene aerogel composites. The average densities were approaching 15-20 mg/cm<sup>3</sup>. This approach allowed for the modulation of distance between the sheets, pore dimension, surface area, and related properties. This specific GO/Polymer ratio has suitable malleability making it a viable candidate for use in conductivity 3D printing; it also has other properties suitable for energy storage, catalysis, sensing and biosensing applications, bioelectronics, and superconductors.</p>

scholarly journals Existence of a Neutral-Impact Maxillo-Mandibular Displacement on Upper Airways Morphology

2021 ◽  
Vol 11 (3) ◽  
pp. 177
Author(s):  
Giovanni Badiali ◽  
Ottavia Lunari ◽  
Mirko Bevini ◽  
Barbara Bortolani ◽  
Laura Cercenelli ◽  
...  
Keyword(s):  
Scientific Evidence ◽  
Three Dimensional ◽  
3D Models ◽  
Individual Case ◽  
Mandibular Advancement ◽  
Upper Airways ◽  
Displacement Threshold ◽  
Significant Difference ◽  
The Individual ◽  
Area And Volume

Current scientific evidence on how orthognathic surgery affects the airways morphology remains contradictory. The aim of this study is to investigate the existence and extension of a neutral-impact interval of bony segments displacement on the upper airways morphology. Its upper boundary would behave as a skeletal displacement threshold differentiating minor and major jaw repositioning, with impact on the planning of the individual case. Pre- and post-operative cone beam computed tomographies (CBCTs) of 45 patients who underwent maxillo-mandibular advancement or maxillary advancement/mandibular setback were analysed by means of a semi-automated three-dimensional (3D) method; 3D models of skull and airways were produced, the latter divided into the three pharyngeal subregions. The correlation between skeletal displacement, stacked surface area and volume was investigated. The displacement threshold was identified by setting three ∆Area percentage variations. No significant difference in area and volume emerged from the comparison of the two surgical procedures with bone repositioning below the threshold (approximated to +5 mm). A threshold ranging from +4.8 to +7 mm was identified, varying in relation to the three ∆Area percentages considered. The ∆Area increased linearly above the threshold, while showing no consistency in the interval ranging from −5 mm to +5 mm.

Synthesis of Polyacetylene-like Modified Graphene Oxide Aerogel and Its Enhanced Electrical Properties

2019 ◽  
Author(s):  
Enrico Greco ◽  
Jing Shang ◽  
jiali zhu ◽  
Tong Zhu
Keyword(s):  
Graphene Oxide ◽  
Three Dimensional ◽  
Single Layer ◽  
Internal Surface ◽  
Solid Material ◽  
Single Layer Graphene ◽  
Covalent Bonds ◽  
Surface Areas ◽  
Modified Graphene Oxide ◽  
The Individual

<p>A graphene-based or carbon-based aerogel is a three-dimensional (3D) solid material in which the carbon atoms are arranged in a sheet-like nanostructure. In this study, we report the synthesis of low-density polymer-modified aerogel monoliths by 3D macro-assemblies of graphene oxide sheets that exhibit significant internal surface areas (982 m<sup>2</sup>/g) and high electrical conductivity (∼0.1 to 1 × 10<sup>2</sup> S/cm). Different types of materials were prepared to obtain a single monolithic solid starting from a suspension of single-layer graphene oxide (GO) sheets, and a polymer, made from the precursors 4-carboxybenzaldehyde and polyvinyl alcohol. These materials were used to cross-link the individual sheets by covalent bonds, resulting in wet-gels that were supercritically dried and then, in some cases, thermally reduced to yield graphene aerogel composites. The average densities were approaching 15-20 mg/cm<sup>3</sup>. This approach allowed for the modulation of distance between the sheets, pore dimension, surface area, and related properties. This specific GO/Polymer ratio has suitable malleability making it a viable candidate for use in conductivity 3D printing; it also has other properties suitable for energy storage, catalysis, sensing and biosensing applications, bioelectronics, and superconductors.</p>

scholarly journals La Torre della Marina di Vietri sulla Costa d’Amalfi: test statistico-predittivi di dati fotogrammetrici

X ◽  
2020 ◽  
Author(s):  
Sara Morena ◽  
Salvatore Barba
Keyword(s):  
Single Case ◽  
Low Cost ◽  
Relative Effectiveness ◽  
Three Dimensional ◽  
3D Models ◽  
Predictive Test ◽  
Historical Building ◽  
Starting Point ◽  
Propagation Law ◽  
The Individual

The Tower of Marina di Vietri on Amalfi Coast: a statistical-predictive test of photogrammetric dataThe focus of the work is on close-range photogrammetry and mainly on the low-cost technologies, experimented in the survey of Tower of Marina di Vietri, a historical building erected in the sixteenth century at Vietri sul Mare in the Province of Salerno. The general objective is to codify a methodology for objectifying the comparisons of the results; hence, the research starts from an original analysis conducted on the returned orthophotos by several photogrammetric paradigms. To estimate its reliability and precision, we proceeded, at first, with the extension and application of an error propagation law and then with the validation of the comparison according to a predictive type test. The first results are presented here after a study on raster images generated according to different algorithms. Subsequently, on each graphic product, 73 points were identified and for each of the relative coordinates the deviation are evaluated by verifying them with the value of the standard deviation. Consequently, for the purpose of greater validation of the methodology, a predictive test was implemented with the aim to confirm the criterion used for the comparison and to guarantee, in probabilistic terms, the values analysed; finally, a further three-dimensional analysis was conducted directly on the 3D models. It is banal to observe that aleatory –subjectivity, etc.– which often characterizes already known approaches, in any case assumed as a starting point, does not always allow to obtain generally valid results and, therefore, extendable beyond the single case study. The implementation of this first test, otherwise, proved to be extremely valid in the survey for architecture, both for an absolute evaluation of the quality of the individual results and for the possibility to estimate, also predictively, the relative effectiveness of the method used. This guarantees the evaluation of the relative percentages of errors in probabilistic terms.

scholarly journals Salbutamol Transport and Deposition in the Upper and Lower Airway with Different Devices in Cats: A Computational Fluid Dynamics Approach

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2431
Author(s):  
Rocio Fernández-Parra ◽  
Pascaline Pey ◽  
Carol Reinero ◽  
Mauro Malvè
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Computational Models ◽  
Three Dimensional ◽  
Airway Disease ◽  
Lower Airway ◽  
Upper Airways ◽  
Tomographic Images ◽  
Computed Tomographic ◽  
Metered Dose

Pressurized metered-dose inhalers (pMDI) with or without spacers are commonly used for the treatment of feline inflammatory airway disease. During traditional airways treatments, a substantial amount of drugs are wasted upstream of their target. To study the efficiency of commonly used devices in the transport of inhaled salbutamol, different computational models based on two healthy adult client-owned cats were developed. Computed tomographic images from one cat were used to generate a three-dimensional geometry, and two masks (spherical and conical shapes) and two spacers (10 and 20 cm) completed the models. A second cat was used to generate a second model having an endotracheal tube (ETT) with and without the same spacers. Airflow, droplet spray transport, and deposition were simulated and studied using computational fluid dynamics techniques. Four regions were evaluated: device, upper airways, primary bronchi, and downstream lower airways/parenchyma (“lung”). Regardless of the model, most salbutamol is deposited in devices and/or upper airways. In general, particles reaching the lung varied between 5.8 and 25.8%. Compared with the first model, pMDI application through the ETT with or without a spacer had significantly higher percentages of particles reaching the lung (p = 0.006).

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

The Solidarity of Distance1

2005 ◽  
Vol 36 (3) ◽  
pp. 103-115 ◽  
Author(s):  
Robert A. Wicklund
Keyword(s):  
Physical Contact ◽  
Emotional Distance ◽  
Starting Point ◽  
Shared Emotions ◽  
Common Goals ◽  
Full Interaction ◽  
The Individual ◽  
Social Incompetence

Abstract: Solidarity in the classic sense pertains to a cohesion among humans that entails physical contact, shared emotions, and common goals or projects. Characteristic cases are to be found among families, close friends, or co-workers. The present paper, in contrast, treats a phenomenon of the solidarity of distance, a solidarity based in fear of certain others and in incompetence to interact with them. The starting point for this analysis is the person who is motivated to interact with others who are unfamiliar or fear-provoking. Given that the fear and momentary social incompetence do not allow a full interaction to ensue, the individual will move toward solidarity with those others on a symbolic level. In this manner the motivation to approach the others is acted upon while physical and emotional distance is retained.

Phonetic iconicity in the evaluative morphology of a sample of Indo-European, Niger-Congo and Austronesian languages

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann
Keyword(s):  
Three Dimensional ◽  
Sound Symbolism ◽  
Three Dimensional Model ◽  
Austronesian Languages ◽  
Place Of Articulation ◽  
European Languages ◽  
Phonetic Symbolism ◽  
The Individual ◽  
Core Vocabulary

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.

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