Mechanical properties of stingray tesserae: High-resolution correlative analysis of mineral density and indentation moduli in tessellated cartilage

2019 ◽  
Vol 96 ◽  
pp. 421-435 ◽  
Author(s):  
Ronald Seidel ◽  
Andreas Roschger ◽  
Ling Li ◽  
Joseph J. Bizzarro ◽  
Qiuting Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Resolution ◽  
Mineral Density ◽  
Correlative Analysis

scholarly journals Jumping exercise preserves bone mineral density and mechanical properties in osteopenic ovariectomized rats even following established osteopenia

2017 ◽  
Vol 28 (4) ◽  
pp. 1461-1471 ◽  
Author(s):  
R . Okubo ◽  
L. S. Sanada ◽  
V. A. Castania ◽  
M. J. Q. Louzada ◽  
F. J. A. de Paula ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Mineral Density ◽  
Bone Mineral ◽  
Ovariectomized Rats ◽  
Mineral Density ◽  
Jumping Exercise

Three-Dimensional High Resolution Scaffold Fiber Architecture and Morphology in Tissue Engineered Heart Valve Tissue

2010 ◽  
Author(s):  
Chad E. Eckert ◽  
Brandon T. Mikulis ◽  
Dane Gerneke ◽  
Danielle Gottlieb ◽  
Bruce Smaill ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Resolution ◽  
Heart Valve ◽  
Structural Information ◽  
Three Dimensional ◽  
Tissue Scaffold ◽  
Valve Tissue ◽  
Sampling Protocols ◽  
Heart Valve Tissue

Engineered heart valve tissue (EHVT) has received much attention as a potential pediatric valve replacement therapy, offering prospective long-term functional improvements over current options. A significant gap in the literature exists, however, regarding estimating tissue mechanical properties from tissue-scaffold composites. Detailed three-dimensional structural information prior to implantation (in vitro) and after implantation in (in vivo) is needed for improved modeling of tissue properties. As such, a novel high-resolution imaging technique will be employed to obtain three-dimensional microstructural information. Analysis techniques will be used to fully quantify constituents of interest including scaffold, collagen, and cellular information and to develop appropriate two-dimensional sectioning sampling protocols. It is the intent of this work to guide modeling efforts to better elucidate EHVT tissue-specific mechanical properties.

The Influence of Trabecular Microstructure on Mechanical Properties and the Pullout Strength of Suture Anchors

2010 ◽  
Author(s):  
Mariya Poukalova ◽  
Christopher M. Yakacki ◽  
Robert E. Guldberg ◽  
Angela Lin ◽  
Ken Gall
Keyword(s):  
Mechanical Properties ◽  
Bone Mineral Density ◽  
Suture Anchor ◽  
Common Type ◽  
Tissue Fixation ◽  
Suture Anchors ◽  
Pullout Strength ◽  
Mineral Density ◽  
Trabecular Microstructure ◽  
Type Of Surgery

Suture anchors provide soft-tissue fixation, often tendons and ligaments, to bone. The most common type of surgery in which suture anchors are used is in rotator cuff repairs, where the anchor is implanted into the humerus to create a point of fixation for the supraspinatus.[1–2] Pullout strength, or the force necessary to pull the anchor from the bone, has been previously used as a metric to compare suture anchor performance. In investigating suture anchor performance, it has been suggested that pullout strength is positively correlated to bone mineral density (BMD).[2]

scholarly journals Heterogeneity of Bone Mineral Density and Fatigue Failure of Human Vertebrae

2012 ◽  
Author(s):  
Yener N. Yeni ◽  
Laila M. Poisson ◽  
Michael J. Flynn
Keyword(s):  
Mechanical Properties ◽  
Bone Mineral Density ◽  
Vertebral Fracture ◽  
Bone Mineral ◽  
Vertebral Fractures ◽  
Important Determinant ◽  
Fatigue Properties ◽  
Static Properties ◽  
Mineral Density ◽  
Significant Interest

Bone qualities that are measurable via clinically available modalities and that can explain fracture risk beyond what is explainable by bone mineral density (BMD) are of significant interest. Evidence from literature suggests that the heterogeneity of BMD within a vertebra, in addition to the average BMD, may be an important determinant of the mechanical properties of a vertebra 1–3 and risk of a clinical vertebral fracture 4. Much of the experimental evidence comes from tests, in which vertebrae are monotonically loaded and relates BMD heterogeneity to the quasi-static properties of a vertebra 1, 3. The appearance of clinical vertebral fractures is in the form of progressive deformities indicating that fatigue processes are involved. However, the relationships between BMD heterogeneity and fatigue properties of a vertebra are not well-understood.

RESERVOIR SCALE CHEMOSTRATIGRAPHY AND FACIES MODELING USING HIGH SAMPLE RATE GEOPHYSICAL SCANS OF WHOLE CORE

2021 ◽  
Author(s):  
John J. Degenhardt ◽  
◽  
Safdar Ali ◽  
Mansoor Ali ◽  
Brian Chin ◽  
...  
Keyword(s):  
Machine Learning ◽  
Mechanical Properties ◽  
High Resolution ◽  
Operating Characteristics ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Vertical Heterogeneity ◽  
Austin Chalk ◽  
Sample Rate ◽  
Petrophysical Logs

Many unconventional reservoirs exhibit a high level of vertical heterogeneity in terms of petrophysical and geo-mechanical properties. These properties often change on the scale of centimeters across rock types or bedding, and thus cannot be accurately measured by low-resolution petrophysical logs. Nonetheless, the distribution of these properties within a flow unit can significantly impact targeting, stimulation and production. In unconventional resource plays such as the Austin Chalk and Eagle Ford shale in south Texas, ash layers are the primary source of vertical heterogeneity throughout the reservoir. The ash layers tend to vary considerably in distribution, thickness and composition, but generally have the potential to significantly impact the economic recovery of hydrocarbons by closure of hydraulic fracture conduits via viscous creep and pinch-off. The identification and characterization of ash layers can be a time-consuming process that leads to wide variations in the interpretations that are made with regard to their presence and potential impact. We seek to use machine learning (ML) techniques to facilitate rapid and more consistent identification of ash layers and other pertinent geologic lithofacies. This paper involves high-resolution laboratory measurements of geophysical properties over whole core and analysis of such data using machine-learning techniques to build novel high-resolution facies models that can be used to make statistically meaningful predictions of facies characteristics in proximally remote wells where core or other physical is not available. Multiple core wells in the Austin Chalk/Eagle Ford shale play in Dimmitt County, Texas, USA were evaluated. Drill core was scanned at high sample rates (1 mm to 1 inch) using specialized equipment to acquire continuous high resolution petrophysical logs and the general modeling workflow involved pre-processing of high frequency sample rate data and classification training using feature selection and hyperparameter estimation. Evaluation of the resulting training classifiers using Receiver Operating Characteristics (ROC) determined that the blind test ROC result for ash layers was lower than those of the better constrained carbonate and high organic mudstone/wackestone data sets. From this it can be concluded that additional consideration must be given to the set of variables that govern the petrophysical and mechanical properties of ash layers prior to developing it as a classifier. Variability among ash layers is controlled by geologic factors that essentially change their compositional makeup, and consequently, their fundamental rock properties. As such, some proportion of them are likely to be misidentified as high clay mudstone/wackestone classifiers. Further refinement of such ash layer compositional variables is expected to improve ROC results for ash layers significantly.

Bone Evaluation by High-Resolution Peripheral Quantitative Computed Tomography in Patients With Adrenal Incidentaloma

2020 ◽  
Vol 105 (8) ◽  
pp. e2726-e2737
Author(s):  
Aline Barbosa Moraes ◽  
Marcela Pessoa de Paula ◽  
Francisco de Paula Paranhos-Neto ◽  
Emanuela Mello Ribeiro Cavalari ◽  
Felipe Fernandes Cordeiro de Morais ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Bone Mineral Density ◽  
High Resolution ◽  
Distal Radius ◽  
Bone Mineral ◽  
Quantitative Computed Tomography ◽  
Adrenal Incidentaloma ◽  
Peripheral Quantitative Computed Tomography ◽  
Mineral Density ◽  
X Ray

Abstract Context Data regarding high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with adrenal incidentaloma (AI) are unknown. Purpose To evaluate the areal bone mineral density (aBMD), microstructure, and fractures in patients with nonfunctioning AI (NFAI) and autonomous cortisol secretion (ACS). Methods We evaluated 45 patients with NFAI (1 mg dexamethasone suppression test [DST] ≤1.8 µg/dL) and 30 patients with ACS (1 mg DST 1.9-5.0 µg/dL). aBMD was measured using dual-energy X-ray absorptiometry; vertebral fracture by spine X-ray; and bone geometry, volumetric bone mineral density (vBMD), and microstructure by HR-pQCT. Results Patients with ACS showed lower aBMD values at the spine, femoral neck, and radius 33% than those with NFAI. Osteoporosis was frequent in both groups: NFAI (64.9%) and ACS (75%). Parameters at the distal radius by HR-pQCT were decreased in patients with ACS compared to those with NFAI: trabecular vBMD (Tb.vBMD, P = 0.03), inner zone of the trabecular region (Inn.Tb.vBMD, P = 0.01), the bone volume/tissue volume ratio (BV/TV, P = 0.03) and trabecular thickness (P = 0.04). As consequence, a higher ratio of the outer zone of the trabecular region/inner zone vBMD (Meta/Inn.vBMD, P = 0.003) was observed. A correlation between the cortisol levels after 1 mg DST and Meta/Inn.vBMD ratio was found (r = 0.29; P = 0.01). The fracture frequency was 73.7% in patients with ACS vs 55.6% in patients with NFAI (P = 0.24). Conclusion Our findings point to an association between trabecular bone microarchitectural derangement at the distal radius and ACS. Our data suggest that AI have a negative impact on bone when assessed by HR-pQCT, probably associated to subclinical hypercortisolism.

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