scholarly journals Design of composite scaffolds and three-dimensional shape analysis for tissue-engineered ear

2013 ◽  
Vol 10 (87) ◽  
pp. 20130413 ◽  
Author(s):  
Thomas M. Cervantes ◽  
Erik K. Bassett ◽  
Alan Tseng ◽  
Anya Kimura ◽  
Nick Roscioli ◽  
...  
Keyword(s):  
Shape Analysis ◽  
Three Dimensional ◽  
Bending Moment ◽  
Three Dimensions ◽  
Local Curvature ◽  
Aesthetic Result ◽  
Before And After ◽  
Titanium Wire ◽  
Invasive Method ◽  
Length Width

Engineered cartilage is a promising option for auricular reconstruction. We have previously demonstrated that a titanium wire framework within a composite collagen ear-shaped scaffold helped to maintain the gross dimensions of the engineered ear after implantation, resisting the deformation forces encountered during neocartilage maturation and wound healing. The ear geometry was redesigned to achieve a more accurate aesthetic result when implanted subcutaneously in a nude rat model. A non-invasive method was developed to assess size and shape changes of the engineered ear in three dimensions. Computer models of the titanium framework were obtained from CT scans before and after implantation . Several parameters were measured including the overall length, width and depth, the minimum intrahelical distance and overall curvature values for each beam section within the framework. Local curvature values were measured to gain understanding of the bending forces experienced by the framework structure in situ . Length and width changed by less than 2%, whereas the depth decreased by approximately 8% and the minimum intrahelical distance changed by approximately 12%. Overall curvature changes identified regions most susceptible to deformation. Eighty-nine per cent of local curvature measurements experienced a bending moment less than 50 µN-m owing to deformation forces during implantation. These quantitative shape analysis results have identified opportunities to improve shape fidelity of engineered ear constructs.

Clinical and laboratory studies of the effectiveness of a non-invasive method of treating caries in the stage of white chalky spot with Icon technology

2021 ◽  
pp. 32-36
Author(s):  
S.U. Maksyukov ◽  
D.V. Yogina ◽  
D.S. Maksyukov
Keyword(s):  
Three Dimensional ◽  
White Spot ◽  
Laboratory Studies ◽  
X Ray ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
Tooth Dentin ◽  
Three Dimensional Models ◽  
Comparison Of The Results

The aim of the study was to evaluate the effectiveness of a non-invasive method of treating caries at the stage of a white chalky spot with the Infiltration Concept (Icon) technology. Materials and methods: the clinical and laboratory study included 5 teeth with caries in the white spot stage, removed according to orthodontic indications. The study included scanning in an X-ray computer microtomograph of selected samples of teeth with caries in the white spot stage before and after treatment of the caries area according to Icon technology. For each sample, 1601 X-ray projections were obtained, which were then reconstructed using the XRM Reconstructor software. The comparison of the mineralization density of the samples was carried out by calibrating the obtained images, reconstructing three-dimensional models of tooth samples and constructing maps of the mineralization fee. Results and conclusions. Data on the mineralization density before and after treatment according to Icon technology were obtained in the following areas of the studied teeth: caries in the white spot stage; dentin bordering on caries (the area touches the dentinoemal border as close as possible to the caries area); the area of healthy enamel on the opposite side of the tooth; dentin bordering on healthy enamel (near the dentinoemal border and as close as possible to the healthy enamel area). A comparison of the results obtained does not allow us to conclude about the effectiveness of treatment according to the Icon technology. Moreover, the mineralization density of the studied areas significantly decreased after the treatment.

scholarly journals Three-Dimensional X-Ray Imaging and Analysis of Fungi on and in Wood

2009 ◽  
Vol 15 (5) ◽  
pp. 395-402 ◽  
Author(s):  
Jan Van den Bulcke ◽  
Matthieu Boone ◽  
Joris Van Acker ◽  
Luc Van Hoorebeke
Keyword(s):  
Three Dimensional ◽  
Three Dimensions ◽  
White Rot ◽  
White Rot Fungus ◽  
Fungal Mycelium ◽  
X Ray ◽  
Fungal Exposure ◽  
X Ray Imaging ◽  
Before And After ◽  
Fundamental Research

AbstractAs wood is prone to fungal degradation, fundamental research is necessary to increase our knowledge aiming at product improvement. Several imaging modalities are capable of visualizing fungi, but the X-ray equipment presented in this article can envisage fungal mycelium in wood nondestructively in three dimensions with submicron resolution. Four types of wood subjected to the action of the white rot fungusCoriolus versicolor(Linnaeus) Quélet (CTB 863 A) were scanned using an X-ray-based approach. Comparison of wood volumes before and after fungal exposure, segmented manually or semiautomatically, showed the presence of the fungal mass on and in the wood samples and therefore demonstrated the usefulness of computed X-ray tomography for mycological and wood research. Further improvements to the experimental setup are necessary to resolve individual hyphae and enhance segmentation.

scholarly journals Tridimensional Regression for Comparing and Mapping 3D Anatomical Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Kendra K. Schmid ◽  
David B. Marx ◽  
Ashok Samal
Keyword(s):  
Shape Analysis ◽  
Three Dimensional ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Coefficient Of Determination ◽  
Anatomical Structures ◽  
Degree Of Similarity

Shape analysis is useful for a wide variety of disciplines and has many applications. There are many approaches to shape analysis, one of which focuses on the analysis of shapes that are represented by the coordinates of predefined landmarks on the object. This paper discusses Tridimensional Regression, a technique that can be used for mapping images and shapes that are represented by sets of three-dimensional landmark coordinates, for comparing and mapping 3D anatomical structures. The degree of similarity between shapes can be quantified using the tridimensional coefficient of determination (). An experiment was conducted to evaluate the effectiveness of this technique to correctly match the image of a face with another image of the same face. These results were compared to the values obtained when only two dimensions are used and show that using three dimensions increases the ability to correctly match and discriminate between faces.

Structural Failure Mechanisms of Common Flexor Tendon Repairs

Hand Surgery ◽  
2015 ◽  
Vol 20 (03) ◽  
pp. 369-379 ◽  
Author(s):  
Tim Sebastian Peltz ◽  
Roger Haddad ◽  
Peter James Scougall ◽  
Sean Nicklin ◽  
Mark Peter Gianoutsos ◽  
...  
Keyword(s):  
Failure Mechanisms ◽  
Biomechanical Testing ◽  
Tendon Repair ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Biomechanical Stability ◽  
Repair Method ◽  
Before And After ◽  
The Stability ◽  
Repair Techniques

Background: This study investigated the exact failure mechanisms of the most commonly used conventional tendon repair techniques. A new method, radiographing repair constructs in antero-posterior and lateral projections before and after tensioning was used. This allowed to precisely analyse failure mechanisms in regards to geometrical changes in all three dimensions. Additionally the biomechanical stability focusing on gapping was tested. Methods: Sheep fore limb deep flexor tendons were harvested and divided in eight groups of ten tendons. Three common variants of the Kessler repair method and four common 4-strand repair techniques were tested. Additionally a new modification of the Adelaide repair was tested. Results: Biomechanical testing showed no significant differences in gapping for the three tested 2-strand Kessler repair groups. Once a double Kessler or 4-strand Kessler repair was performed the stability of the repair improved significantly. Further significant improvements in biomechanical stability could be achieved by using cross locks in the repair like in the Adelaide repair method. Qualitative analysis using radiographs showed that all Kessler repair variants unfolded via rotations around the transverse suturing component, no matter which variant was used. Conclusions: Additional to the commonly described constriction of the repair construct, the rotating deformation is the main reason for repair site gapping in Kessler tendon repair methods. The term “locking” in a Kessler repair is misleading. The cruciate repairs tended to loose grip and drag (cheese-wire) through the tendon and therefore lead to gapping. The most stable repair constructs in all three dimensions were the Adelaide repair and its interlocking modification. This is due to the superior anchoring qualities of its cross locks and three dimensional stability.

Tumor size and prognosis in aggressively treated osteosarcoma.

1996 ◽  
Vol 14 (3) ◽  
pp. 848-858 ◽  
Author(s):  
P Bieling ◽  
N Rehan ◽  
P Winkler ◽  
K Helmke ◽  
R Maas ◽  
...  
Keyword(s):  
Tumor Size ◽  
Tumor Volume ◽  
Cox Regression ◽  
Prognostic Significance ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Cox Regression Analysis ◽  
X Ray ◽  
Dimensional Measure ◽  
Length Width

PURPOSE The aim of this retrospective analysis was to investigate the prognostic significance and optimal measures of tumor size in osteosarcoma treated with intensive neoadjuvant chemotherapy. PATIENTS AND METHODS Initial anterior-posterior (AP) and lateral x-ray films of 128 patients treated within the trials Cooperative Osteosarcoma Study (COSS)-80, -82, and -86, were evaluated for the following three tumor diameters: length, width, and depth. Metastasis-free survival (MFS) analyses were performed in univariate and multivariate models with one, two, and three dimensions of the tumor as absolute or relative measures (tumor length, referred to bone length, plane and volume to body-surface area). RESULTS Univariate analyses of MFS showed a high prognostic significance of all absolute measures. Relative measures, at best, showed a comparable predictive value. Cox regression analysis indicated the high prognostic significance of absolute tumor volume (ATV; P < .0001) and histologic response (P < .0001). None of 19 patients with an ATV < or = 70 cm3 and only four of 53 with an ATV < or = 150 cm3 relapsed, while in patients with an ATV more than 150 cm3, the relapse rate remained 40% to 60%, irrespective of further increase in volume. CONCLUSION Initial tumor size is an important and easily obtainable prognostic factor in osteosarcoma and may serve as a basis for risk-adapted therapy. It is best represented by the absolute three-dimensional measure ATV. There is a cut-off point regarding the incidence of metastases at a tumor volume of approximately 150 cm3 as calculated from two-plane x-ray films.

On Dredging Renovation of High-Piled Wharf by FEA

2014 ◽  
Vol 1065-1069 ◽  
pp. 613-618
Author(s):  
Zhi Hui Liu ◽  
Liang De He ◽  
Ying Fa He ◽  
Yuan Yuan Lu
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
Finite Element Models ◽  
Sheet Pile ◽  
Bank Slope ◽  
Before And After ◽  
Dimensional Finite Element ◽  
Pile Caps ◽  
Three Dimensional Finite Element ◽  
Sheet Pile Wall

In this paper, high-piled wharf is reinforced with a view to studying how the wharf dredging renovation affects its structure. As regarding the problem that the original balance of the bank slope is destroyed after upgrading, two retrofit schemes that set sheet pile wall at anterior wharf and low-piled caps at surcharge area are conducted to analyze the bank slope deformation and the inter force before and after wharf retrofit by means of three-dimensional finite element models. The analysis shows that for the scheme of setting sheet pile wall at front wharf, the inter force of the anterior pile station reduced while that of the post pile station near the stack area remains large. For the other scheme, the bending moment of the pile that closes to stack area significantly decreases after setting low pile caps. If both schemes are adopted coherently, the reinforcement effects to the anterior and post pile stations would be improved greatly.

Three-Dimensional Measurement of Local Strain Distribution by Tracking Microstructural Features in High-Resolution SR-CT Image

2007 ◽  
Vol 345-346 ◽  
pp. 1153-1156 ◽  
Author(s):  
Masakazu Kobayashi ◽  
Hiroyuki Toda ◽  
Tomomi Ohgaki ◽  
Kentaro Uesugi ◽  
David S. Wilkinson ◽  
...  
Keyword(s):  
High Resolution ◽  
Strain Distribution ◽  
Tensile Deformation ◽  
Three Dimensional ◽  
Local Strain ◽  
Three Dimensions ◽  
Inhomogeneous Strain ◽  
Model Sample ◽  
Before And After ◽  
Three Dimensional Measurement

The local elastic and plastic strain during deformation are very complicated and different form the macroscopic strain, because most materials have inhomogeneous microstructure. In this study, local strain distribution in three dimensions has been measured using the new developed method based on image analysis in high-resolution synchrotron radiation computed tomography (SR-CT). Model and practical specimens, which made of cupper alloy and aluminum alloy, respectively, were prepared for a development procedure and application of local strain measurements. Gauging intervals of microstructural features before and after deformation gave us information of inhomogeneous local strain distribution in three dimensions. High strain was observed in a necking region appeared after tensile deformation in the model sample. A combination of non-destructive measurements by SR-CT and three-dimensional analysis revealed inhomogeneous strain distributions in practical aluminum samples.

convergent-beam diffraction from surfaces

1987 ◽  
Vol 45 ◽  
pp. 30-33
Author(s):  
J. A. Eades ◽  
A. E. Smith ◽  
D. F. Lynch
Keyword(s):  
Reciprocal Lattice ◽  
Three Dimensional ◽  
Grazing Incidence ◽  
Three Dimensions ◽  
Plane Figure ◽  
Transmission Electron ◽  
Convergent Beam ◽  
Beam Patterns ◽  
Beam Diffraction

It is quite simple (in the transmission electron microscope) to obtain convergent-beam patterns from the surface of a bulk crystal. The beam is focussed onto the surface at near grazing incidence (figure 1) and if the surface is flat the appropriate pattern is obtained in the diffraction plane (figure 2). Such patterns are potentially valuable for the characterization of surfaces just as normal convergent-beam patterns are valuable for the characterization of crystals.There are, however, several important ways in which reflection diffraction from surfaces differs from the more familiar electron diffraction in transmission.GeometryIn reflection diffraction, because of the surface, it is not possible to describe the specimen as periodic in three dimensions, nor is it possible to associate diffraction with a conventional three-dimensional reciprocal lattice.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

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