Effects of Cell Shape and Strut Cross-Sectional Area Variations on the Elastic Properties of Three-Dimensional Open-Cell Foams

2004 ◽  
Author(s):  
Ke Li ◽  
Xin-Lin Gao ◽  
Ghatu Subhash
Keyword(s):  
Elastic Properties ◽  
Cell Shape ◽  
Three Dimensional ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Open Cell ◽  
Open Cell Foams

Form follows function: how muscle shape is regulated by work

2000 ◽  
Vol 88 (3) ◽  
pp. 1127-1132 ◽  
Author(s):  
Brenda Russell ◽  
Delara Motlagh ◽  
William W. Ashley
Keyword(s):  
Muscle Cell ◽  
Cell Shape ◽  
Force Production ◽  
Cardiac Cells ◽  
Cross Sectional Area ◽  
Dynamic Responses ◽  
Mechanical Activity ◽  
Sectional Area ◽  
Cross Sectional ◽  
A Cell

What determines the shape, size, and force output of cardiac and skeletal muscle? Chicago architect Louis Sullivan (1856–1924), father of the skyscraper, observed that “form follows function.” This is as true for the structural elements of a striated muscle cell as it is for the architectural features of a building. Function is a critical evolutionary determinant, not form. To survive, the animal has evolved muscles with the capacity for dynamic responses to altered functional demand. For example, work against an increased load leads to increased mass and cross-sectional area (hypertrophy), which is directly proportional to an increased potential for force production. Thus a cell has the capacity to alter its shape as well as its volume in response to a need for altered force production. Muscle function relies primarily on an organized assembly of contractile and other sarcomeric proteins. From analysis of homogenized cells and molecular and biochemical assays, we have learned about transcription, translation, and posttranslational processes that underlie protein synthesis but still have done little in addressing the important questions of shape or regional cell growth. Skeletal muscles only grow in length as the bones grow; therefore, most studies of adult hypertrophy really only involve increased cross-sectional area. The heart chamber, however, can extend in both longitudinal and transverse directions, and cardiac cells can grow in length and width. We know little about the regulation of these directional processes that appear as a cell gets larger with hypertrophy or smaller with atrophy. This review gives a brief overview of the regulation of cell shape and the composition and aggregation of contractile proteins into filaments, the sarcomere, and myofibrils. We examine how mechanical activity regulates the turnover and exchange of contraction proteins. Finally, we suggest what kinds of experiments are needed to answer these fundamental questions about the regulation of muscle cell shape.

Nasal vestibule wall elasticity: interactions with a nasal dilator strip

1999 ◽  
Vol 86 (5) ◽  
pp. 1638-1643 ◽  
Author(s):  
T. C. Amis ◽  
J. P. Kirkness ◽  
E. di Somma ◽  
J. R. Wheatley
Keyword(s):  
Elastic Properties ◽  
Cross Sectional Area ◽  
Horizontal Direction ◽  
Sectional Area ◽  
Cross Sectional ◽  
Nasal Vestibule ◽  
Wall Displacement ◽  
Recoil Force ◽  
Wall Compliance

We studied the effect of an adhesive external nasal dilator strip (ENDS) on external nasal geometry in 20 healthy Caucasian adults (10 men, 10 women; age 21–45 yr). The recoil force exerted by ENDS was estimated by bending the device ( n = 10) with known weights. In the horizontal direction, a small/medium-sized ENDS in situ exerted a unilateral recoil force of 21.4–22.6 g. Application of ENDS resulted in a displacement of the lateral nasal vestibule walls that had both anterosuperior and horizontal components and that was maintained over an 8-h period. The resultant unilateral nasal vestibule wall displacement at the tip of the device was at 47.6 ± 2.0° to the horizontal (as related to the plane of the device when in situ) and had a magnitude of 3.5 ± 0.1 mm. ENDS increased external nasal cross-sectional area by 23.0–65.3 mm2. Nasal vestibule wall compliance was estimated at 0.05–0.16 mm/g. Thus ENDS applies a relatively constant abducting force irrespective of nasal width. Variable responsiveness to ENDS may be related to differences in elastic properties of the nasal vestibule wall.

scholarly journals Nondimensional translational characteristics of elastomer components

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Andreas Dutzler ◽  
◽  
Christian Buzzi ◽  
Martin Leitner ◽  
◽  
...  
Keyword(s):  
Elastic Properties ◽  
Numerical Study ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Component Size ◽  
Rail Vehicles ◽  
Force Displacement

Elastomer components are used in both primary and secondary spring stages in bogies of rail vehicles. The design of spring components of a bogie requires knowledge of the calculation of the elastic properties of these components. An elastomer spring component is typically analyzed in the dimension to be investigated. Calculated force-displacement curves are directly related to the material and dimension of the component itself. The objective of this paper is to establish generalized or, in other words, universally valid force-displacement characteristics by breaking the entanglement with component size. The advantage of this approach is the extended validity of the results for a specific spring shape of any size. The simulations are performed only once for each shape and may be converted to any other size using the proposed methodology. A numerical study of a layer spring with rectangular cross-sectional area and fixed edges on both top and bottom sides serves as a reference example.

scholarly journals X-ray CT Analysis of the Cross-Section of a 3D-Printed Deformed Layer

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7764
Author(s):  
Ho-Jae Lee ◽  
Eun-A Seo ◽  
Won-Woo Kim ◽  
Jun-Mo Yang ◽  
Jae-Heum Moon
Keyword(s):  
Three Dimensional ◽  
Travel Speed ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
X Ray ◽  
Deformed Layer ◽  
Ct Analysis ◽  
3D Printed ◽  
The Cross

In this study, we experimentally analyzed the deformation shape of stacked layers developed using three-dimensional (3D) printing technology. The nozzle traveling speed was changed to 80, 90, 100, and 110 mm/s when printing the layers to analyze its effect on layer deformation. Furthermore, the cross-sectional area and the number of layers were analyzed by printing five layers with overall dimensions of 1000 (w) × 2200 (l) × 50 (h) mm (each layer was 10 mm high) using Vernier calipers. Moreover, we analyzed the interface and cross-sectional area of layers that are difficult to confirm visually using X-ray computed tomography (X-ray CT) analysis. As a result of measuring the deformation at the center of the layer, it was confirmed that the deformation was greater for lower nozzle traveling speeds. Consequently, the X-ray CT analysis verified that the layer had the same cross-sectional area irrespective of the layer printing order at the same nozzle travel speed, even if the layer was deformed.

Serial measurement of cross-sectional area in peripheral vein grafts using three-dimensional ultrasound

2001 ◽  
Vol 27 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Daniel F Leotta ◽  
Jean F Primozich ◽  
Kirk W Beach ◽  
Robert O Bergelin ◽  
D.Eugene Strandness
Keyword(s):  
Three Dimensional ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Peripheral Vein ◽  
Cross Sectional ◽  
Vein Grafts ◽  
Serial Measurement

scholarly journals Risk factors for small pharyngeal airway dimensions in preorthodontic children: A three-dimensional study

2016 ◽  
Vol 87 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Seerone Anandarajah ◽  
Raahib Dudhia ◽  
Andrew Sandham ◽  
Liselotte Sonnesen
Keyword(s):  
Skeletal Maturity ◽  
Three Dimensional ◽  
Cross Sectional Area ◽  
Craniofacial Morphology ◽  
Sectional Area ◽  
Cross Sectional ◽  
Pharyngeal Airway ◽  
And Gender ◽  
Relevant Factors ◽  
Airway Dimensions

ABSTRACT Objective: To analyze which parameters, gathered from standard orthodontic diagnostic material, were most relevant for identifying small pharyngeal airway dimensions in preorthodontic children. Materials and Methods: The sample was composed of 105 cone beam computed tomography scans of healthy preorthodontic children (44 boys, 61 girls; mean age, 10.7 ± 2.4 years). Airway volume and minimal cross-sectional area were three-dimensionally assessed. Cephalometric features and skeletal maturity were assessed on generated two-dimensional cephalograms. Associations were analyzed and adjusted for age, gender, and skeletal maturity by multiple regression analyses. Results: Airway volume and minimal cross-sectional area were significantly smaller in prepubertal children (P < .001, P < .05, respectively) and positively associated with age (P < .001, P < .01, respectively). After adjustment of age, skeletal maturity and gender significant associations were found between pharyngeal airway dimensions and craniofacial morphology. Airway volume was positively associated with maxillary and mandibular width (P < .01; P < .001, respectively) and anterior face height (P < .05; P < .05, respectively). Minimal cross-sectional area was positively associated with maxillary and mandibular width (P < .01; P < .001, respectively) and negatively associated with sagittal jaw relationship (AnPg, P < .05). Mandibular width and age were the most relevant factors for airway volume (r2 = 0.36). Mandibular width and sagittal jaw relationship were the most relevant factors for minimal cross-sectional area (r2 = 0.16). Conclusion: Pharyngeal airway dimensions were significantly associated with age, skeletal maturity, and craniofacial morphology in all three planes. Children with a reduced mandibular width and increased sagittal jaw relationship are particularly at risk of having small pharyngeal airway dimensions.

scholarly journals Three-dimensional muscle architecture of the infant and adult trapezius: a cadaveric study

2021 ◽  
Vol 15 (1) ◽  
pp. 26-35
Author(s):  
Mikaela L. Stiver ◽  
Luke R. Bradshaw ◽  
Ethan M. Breinhorst ◽  
Anne M. R. Agur ◽  
S. Ali Mirjalili
Keyword(s):  
Fiber Bundle ◽  
Three Dimensional ◽  
Trapezius Muscle ◽  
Shoulder Girdle ◽  
Muscle Architecture ◽  
Cross Sectional Area ◽  
Cadaveric Study ◽  
Sectional Area ◽  
Cross Sectional ◽  
3D Architecture

Objectives: The elaborate morphometry of the human trapezius muscle facilitates its involvement in numerous active movements of the shoulder girdle and passive stabilization of the upper extremity. Despite its functional importance throughout the lifespan, little is known about the 3D architecture of trapezius at any post-natal timepoints. Accordingly, the aim of this preliminary cadaveric study was to digitize, quantify, model, and compare the 3D architecture of trapezius at two temporal extremes: infancy and adulthood. Methods: We examined trapezius in two female formalin-embalmed cadavers, aged 6 months and 72 years, respectively. We meticulously dissected each muscle, allowing us to digitize and model the comprehensive muscle architecture in situ at the fiber bundle level. We quantified standard architectural parameters to facilitate comparison between each functional partition of trapezius (i.e., descending, transverse, ascending) and proportionally between the infant and adult specimens. Results: We found markedly different patterns in fiber bundle length range, physiological cross-sectional area, and muscle volume within and between muscles. Notably, the proportional physiological cross-sectional area of the ascending and descending partitions was equal (1:1) in the infant, in contrast to 3:1 in the adult. The transverse partitions were proportionally similar, accounting for over half of the whole muscle physiological cross-sectional area in both specimens. Conclusion: This study provides preliminary insights into infant and adult trapezius architecture at an unparalleled level of detail and precision. The quantifiable architectural differences appear to coincide with functional development-a notion that warrants further investigation in larger samples and with longitudinal approaches.

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