scholarly journals Microanatomy of Early Devonian book lungs

2008 ◽  
Vol 4 (2) ◽  
pp. 212-215 ◽  
Author(s):  
Carsten Kamenz ◽  
Jason A Dunlop ◽  
Gerhard Scholtz ◽  
Hans Kerp ◽  
Hagen Hass
Keyword(s):  
Comparative Studies ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Early Devonian ◽  
Book Lungs ◽  
Air Space ◽  
Fine Structures ◽  
First Time ◽  
Non Destructive

The book lungs of an exceptionally preserved fossil arachnid (Trigonotarbida) from the Early Devonian (approx. 410 Myr ago) Rhynie cherts of Scotland were studied using a non-destructive imaging technique. Our three-dimensional modelling of fine structures, based on assembling successive images made at different focal planes through the translucent chert matrix, revealed for the first time fossil trabeculae: tiny cuticular pillars separating adjacent lung lamellae and creating a permanent air space. Trabeculae thus show unequivocally that trigonotarbids were fully terrestrial and that the microanatomy of the earliest known lungs is indistinguishable from that in modern Arachnida. A recurrent controversy in arachnid evolution is whether the similarity between the book lungs of Pantetrapulmonata (i.e. spiders, trigonotarbids, etc.) and those of scorpions is a result of convergence. Drawing on comparative studies of extant taxa, we have identified explicit characters (trabeculae, spines on the lamellar edge) shared by living and fossil arachnid respiratory organs, which support the hypothesis that book lungs were derived from a single, common, presumably terrestrial, ancestor.

A Methodology for Mechanical Measurements of Technical Constants of Trabecular Bone

1988 ◽  
Vol 17 (4) ◽  
pp. 169-173 ◽  
Author(s):  
L H Yahia ◽  
G Drouin ◽  
P Duval
Keyword(s):  
Trabecular Bone ◽  
Three Dimensional ◽  
Lumbar Vertebrae ◽  
Bony Tissue ◽  
Ultrasonic Methods ◽  
Vertebral Trabecular Bone ◽  
Young’S Moduli ◽  
Orthotropic Properties ◽  
First Time ◽  
Non Destructive

Vertebral trabecular bone was tested by non-destructive uniaxial and triaxial loadings with the purpose of investigating the orthotropic properties of bone. A triaxial testing apparatus using hydrostatic pressure was developed and allowed to characterise the bony tissue in a three-dimensional stressed state. Thirty specimens, in the form of 10 mm cubes, were tested. The Young's moduli obtained in this study for the trabecular bone of human lumbar vertebrae are found to be in agreement with the values obtained by ultrasonic methods. Analyses of triaxial compressive tests provided, for the first time, the Poisson's ratios of vertebral trabecular bone. These values are found to satisfy thermodynamic restrictions established by Cowin and Van Buskirk (1986). Finally, no significant differences in the material properties were found for segment level (L3-L4).

Three-Dimensional Ultrastructure of Agmenellum Quadruplicatum

1982 ◽  
Vol 40 ◽  
pp. 318-319
Author(s):  
S. A. Nierzwicki ◽  
D. L. Balkwil ◽  
S. E. Stevens
Keyword(s):  
Green Alga ◽  
Three Dimensional ◽  
Cyanobacterial Cell ◽  
Blue Green Alga ◽  
Unicellular Cyanobacterium ◽  
Cell Structures ◽  
Agmenellum Quadruplicatum ◽  
Fine Structures ◽  
First Time

Agmenellum quadruplicatum is a unicellular cyanobacterium (blue-green alga) measuring ≃2.5 x 5.0 μm. The basic ultrastructural features of this organism have been characterized previously, but there have been no reports fully describing the three-dimensional organization of these features within the cell. Yet, such information would be valuable in regard to understanding the mechanism by which cell structures in cyanobacteria function. The purpose of this study, then, was to reconstruct for the first time the three-dimensional arrangement of fine structures in a cyanobacterial cell.

Abstract 18237: Non-invasive Three Dimensional Imaging of Ventricular Arrhythmias: In-procedure Simultaneous Mapping of Ventricular Tachycardia and Premature Ventricular Complexes

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Long Yu ◽  
Steve Pogwizd ◽  
Hugh T McElderry ◽  
Ting Yang ◽  
Bin He
Keyword(s):  
Ventricular Tachycardia ◽  
Imaging Technique ◽  
Three Dimensional ◽  
3 Dimensional ◽  
Premature Ventricular Complexes ◽  
Non Invasive ◽  
Imaging Results ◽  
Body Surface Potential ◽  
Good Concordance ◽  
First Time

Introduction: Noninvasive activation imaging and the identification of initiation sites or reentrant circuits are highly desirable for aiding catheter ablative treatment of ventricular arrhythmia. While approaches are being developed to image epicardial potential, Cardiac Electrical Sparse Imaging (CESI), a 3-dimensional noninvasive activation imaging technique offers insight into intramural activation. In this study, we report the first clinical study of the CESI technique with in-procedure simultaneous mapping of Ventricular Tachycardia (VT) and Premature Ventricular Complexes (PVCs). Methods: Body surface potential maps (BSPMs) were recorded using 170±9 electrodes in 4 patients (2 males, 2 females, age 53±5) with VT and/or PVC in the EP lab simultaneously with CARTO mapping and ablation. CT or MRI images were obtained for individualized volume conductor modeling. Activation sequences were estimated using CESI upon the 40 isolated PVC or VT beats induced by programmed stimulation or isoproterenol infusion. Imaging results were compared with CARTO map and ablation sites/outcomes. Results: Good concordance was observed between the imaged results and the EP study. A Correlation Coefficient of 0.76±0.04 and Relative Error of 0.22±0.05 were found between the imaged activation sequences and the Local Activation Time maps from CARTO. The imaged initiation sites well co-localized with the ablation outcomes with Localization Error of 8±1.3mm from the last ablation site and 3.3±1.7mm from the nearest ablation site. Conclusions: We demonstrate for the first time that the beat-to-beat 3D activation imaging technique CESI can be applied clinically with simultaneous mapping in the EP lab. The noninvasive imaging results are in good agreement with the EP study and catheter ablation outcome. The promising results suggest CESI warrants further investigation and has the potential to become a clinically useful technology guiding ablation procedures in patients.

3D Laser Scanner Techniques

2011 ◽  
pp. 500-527
Author(s):  
Mercedes Farjas ◽  
Jesús Martinez-Frias ◽  
Jose María Hierro
Keyword(s):  
Morphological Study ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanner ◽  
3D Laser Scanning ◽  
The Subject ◽  
First Time ◽  
Non Destructive ◽  
Arbitrary Objects ◽  
Scanning Systems

The use of 3D scanning systems for acquiring and analyzing the external shape features of arbitrary objects has different applications in different cultural, scientific, and technological fields. In this work, 3D laser scanning techniques are used, for the first time, to our knowledge, as a novel and non-destructive application for the morphological study of meteorite impact rocks. The subject of the study was a rock displaying impact textures and associated with the Karikkoselkä impact crater (Finland) (Lehtinen et al. 1996). This methodology permitted: (1) a computerized three-dimensional modelling to be carried out on the bulk impact-related rock; (2) other more specific characterizations to be performed, such as detailed topographic studies of its surface impact features; (3) some physical properties of the rock to be determined (volume); (4) the shatter cone impact texture to be completed with a realistic estimation of its convergence angle; and (5) a broad demonstration of the significance and effectiveness of 3D laser scanning techniques as a complementary tool for the study of this type of meteoritic impact-related rocks.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

EMCAT: An automatic image-processing system for electron-microscopic tomography

1994 ◽  
Vol 52 ◽  
pp. 418-419
Author(s):  
Weiping Liu ◽  
John W. Sedat ◽  
David A. Agard
Keyword(s):  
Image Processing ◽  
Structural Information ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Processing System ◽  
Electron Microscopic ◽  
Data Set ◽  
Ordered Structures ◽  
Automatic Image Processing ◽  
Em Tomography

Any real world object is three-dimensional. The principle of tomography, which reconstructs the 3-D structure of an object from its 2-D projections of different view angles has found application in many disciplines. Electron Microscopic (EM) tomography on non-ordered structures (e.g., subcellular structures in biology and non-crystalline structures in material science) has been exercised sporadically in the last twenty years or so. As vital as is the 3-D structural information and with no existing alternative 3-D imaging technique to compete in its high resolution range, the technique to date remains the kingdom of a brave few. Its tedious tasks have been preventing it from being a routine tool. One keyword in promoting its popularity is automation: The data collection has been automated in our lab, which can routinely yield a data set of over 100 projections in the matter of a few hours. Now the image processing part is also automated. Such automations finish the job easier, faster and better.

Electrical Capacitance Volume Tomography (ECVT) for industrial and medical applications-An Overview

2015 ◽  
Vol 11 (1) ◽  
pp. 2897-2908
Author(s):  
Mohammed S.Aljohani
Keyword(s):  
Imaging Technique ◽  
Three Dimensional ◽  
Biological Processes ◽  
Electrical Capacitance ◽  
Image Reconstruction Techniques ◽  
Phase Dynamics ◽  
Non Invasive ◽  
Electrical Capacitance Volume Tomography ◽  
And Performance ◽  
Optimization And Performance

Tomography is a non-invasive, non-intrusive imaging technique allowing the visualization of phase dynamics in industrial and biological processes. This article reviews progress in Electrical Capacitance Volume Tomography (ECVT). ECVT is a direct 3D visualizing technique, unlike three-dimensional imaging, which is based on stacking 2D images to obtain an interpolated 3D image. ECVT has recently matured for real time, non-invasive 3-D monitoring of processes involving materials with strong contrast in dielectric permittivity. In this article, ECVT sensor design, optimization and performance of various sensors seen in literature are summarized. Qualitative Analysis of ECVT image reconstruction techniques has also been presented.

Acoustic and Photoacoustic Inspection of Through-Silicon Vias in the GHz-Frequency Band

2017 ◽  
Author(s):  
Sebastian Brand ◽  
Michael Kögel ◽  
Frank Altmann ◽  
Ingrid DeWolf ◽  
Ahmad Khaled ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Frequency Band ◽  
Process Development ◽  
Three Dimensional ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Vertical Interconnection ◽  
Testing Techniques ◽  
Silicon Vias ◽  
Non Destructive

Abstract Through Silicon Via (TSV) is the most promising technology for vertical interconnection in novel three-dimensional chip architectures. Reliability and quality assessment necessary for process development and manufacturing require appropriate non-destructive testing techniques to detect cracks and delamination defects with sufficient penetration and imaging capabilities. The current paper presents the application of two acoustically based methods operating in the GHz-frequency band for the assessment of the integrity of TSV structures.

scholarly journals Cobalt-based magnetic Weyl semimetals with high-thermodynamic stabilities

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Luo ◽  
Yuma Nakamura ◽  
Jinseon Park ◽  
Mina Yoon
Keyword(s):  
Tight Binding ◽  
Three Dimensional ◽  
Interlayer Coupling ◽  
First Principles Calculation ◽  
Optimization Approach ◽  
Binding Model ◽  
Nodal Lines ◽  
Weyl Semimetal ◽  
Topological Quantum ◽  
First Time

AbstractRecent experiments identified Co3Sn2S2 as the first magnetic Weyl semimetal (MWSM). Using first-principles calculation with a global optimization approach, we explore the structural stabilities and topological electronic properties of cobalt (Co)-based shandite and alloys, Co3MM’X2 (M/M’ = Ge, Sn, Pb, X = S, Se, Te), and identify stable structures with different Weyl phases. Using a tight-binding model, for the first time, we reveal that the physical origin of the nodal lines of a Co-based shandite structure is the interlayer coupling between Co atoms in different Kagome layers, while the number of Weyl points and their types are mainly governed by the interaction between Co and the metal atoms, Sn, Ge, and Pb. The Co3SnPbS2 alloy exhibits two distinguished topological phases, depending on the relative positions of the Sn and Pb atoms: a three-dimensional quantum anomalous Hall metal, and a MWSM phase with anomalous Hall conductivity (~1290 Ω−1 cm−1) that is larger than that of Co2Sn2S2. Our work reveals the physical mechanism of the origination of Weyl fermions in Co-based shandite structures and proposes topological quantum states with high thermal stability.

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