The Bone Cartilage Interface and Osteoarthritis

Calcified Tissue International ◽

10.1007/s00223-021-00866-9 ◽

2021 ◽

Author(s):

Alan Boyde

Keyword(s):

Deep Layer ◽

High Density ◽

X Ray ◽

Local Loss ◽

Woven Bone ◽

Rest Periods ◽

Calcified Cartilage ◽

Marrow Space ◽

Micro Tomography ◽

Repair Phase

AbstractThis review describes results obtained with tissue from prior studies of equine and human osteoarthritis (OA). The main methods considered are scanning electron microscopy, novel methods in light microscopy and X-ray Micro-tomography. The same samples have been re-utilised in several ways. The tissues described are hyaline articular cartilage (HAC; or substitutes), with its deep layer, articular calcified cartilage (ACC), whose deep surface is resorbed in cutting cone events to allow the deposition of subchondral bone (SCB). Multiple tidemarks are normal. Turnover at the osteochondral (ACC-HAC-SCB) junction is downregulated by overload exercise, conversely, during rest periods. Consequent lack of support predisposes to microfracture of the ACC-SCB plate, in the resorption-related repair phase of which the plate is further undermined to form sink holes. The following characteristics contribute to the OA scenario: penetrating resorption canals and local loss of ACC; cracking of ACC and SCB; sealing of cracks with High-Density Mineral Infill (HDMI); extrusion of HDMI into HAC to form High-Density Mineral Protrusions (HDMP) in HAC which may fragment and contribute to its destruction; SCB marrow space infilling and densification with (at first) woven bone; disruption, fibrillation and loss of HAC; eburnation; repair with abnormal tissues including fibrocartilage and woven bone; attachment of Sharpey fibres to SCB trabeculae and adipocyte-moulded extensions to trabeculae (excrescences).

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Three-dimensional orientation of compression-molded high-density polyethylene/wood fibers using X-ray micro-tomography

Journal of Cellular Plastics ◽

10.1177/0021955x14528932 ◽

2014 ◽

Vol 51 (1) ◽

pp. 45-57 ◽

Cited By ~ 3

Author(s):

U Saeed ◽

G Rizvi

Keyword(s):

High Density Polyethylene ◽

Three Dimensional ◽

High Density ◽

Wood Fibers ◽

X Ray ◽

Micro Tomography

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X-ray micro tomography in the scanning electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100107678 ◽

1978 ◽

Vol 36 (1) ◽

pp. 106-107 ◽

Cited By ~ 1

Author(s):

W. Brünger

Keyword(s):

Electron Beam ◽

Electron Microscope ◽

Scanning Electron Microscope ◽

Target Surface ◽

The Body ◽

X Rays ◽

Cross Sectional ◽

X Ray ◽

Micro Tomography ◽

Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

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Composition and Surface Topography Effects on Apatite-Forming Ability of Ceramic-Polymer Composites

MRS Proceedings ◽

10.1557/proc-774-o7.26 ◽

2003 ◽

Vol 774 ◽

Author(s):

Susan M. Rea ◽

Serena M. Best ◽

William Bonfield

Keyword(s):

Surface Topography ◽

High Density Polyethylene ◽

High Density ◽

Apatite Layer ◽

Biologically Active ◽

Human Blood Plasma ◽

Apatite Formation ◽

Polyethylene Matrix ◽

Composite Surface ◽

X Ray

AbstractHAPEXTM (40 vol% hydroxyapatite in a high-density polyethylene matrix) and AWPEX (40 vol% apatite-wollastonite glass ceramic in a high density polyethylene matrix) are composites designed to provide bioactivity and to match the mechanical properties of human cortical bone. HAPEXTM has had clinical success in middle ear and orbital implants, and there is great potential for further orthopaedic applications of these materials. However, more detailed in vitro investigations must be performed to better understand the biological interactions of the composites and so the bioactivity of each material was assessed in this study. Specifically, the effects of controlled surface topography and ceramic filler composition on apatite layer formation in acellular simulated body fluid (SBF) with ion concentration similar to those of human blood plasma were examined. Samples were prepared as 1 cm × 1 cm × 1 mm tiles with polished, roughened, or parallel-grooved surface finishes, and were incubated in 20 ml of SBF at 36.5 °C for 1, 3, 7, or 14 days. The formation of a biologically active apatite layer on the composite surface after immersion was demonstrated by thin-film x-ray diffraction (TF-XRD), environmental scanning electron microscopy (ESEM) imaging and energy dispersive x-ray (EDX) analysis. Variations in sample weight and solution pH over the period of incubation were also recorded. Significant differences were found between the two materials tested, with greater bioactivity in AWPEX than HAPEXTM overall. Results also indicate that within each material the surface topography is highly important, with rougher samples correlated to earlier apatite formation.

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Synchrotron X-ray phase contrast micro tomography to explore the morphology of abdominal organs in Pterostichus melas italicus Dejean, 1828 (Coleoptera, Carabidae)

Arthropod Structure & Development ◽

10.1016/j.asd.2021.101044 ◽

2021 ◽

Vol 62 ◽

pp. 101044

Author(s):

Sandro Donato ◽

Maria Luigia Vommaro ◽

Giuliana Tromba ◽

Anita Giglio

Keyword(s):

Phase Contrast ◽

X Ray ◽

Abdominal Organs ◽

Micro Tomography

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Freeze–Thaw Resistance and Air-Void Analysis of Concrete with Recycled Glass–Pozzolan Using X-ray Micro-Tomography

Materials ◽

10.3390/ma14010154 ◽

2020 ◽

Vol 14 (1) ◽

pp. 154

Author(s):

Marija Krstic ◽

Julio F. Davalos ◽

Emanuele Rossi ◽

Stefan C. Figueiredo ◽

Oguzhan Copuroglu

Keyword(s):

Fly Ash ◽

Pore Structure ◽

The United States ◽

Adsorption Method ◽

X Ray ◽

Freeze Thaw ◽

Void System ◽

Spatial Parameters ◽

Micro Tomography ◽

Air Void

Recent studies have shown promising potential for using Glass Pozzolan (GP) as an alternative supplementary cementitious material (SCM) due to the scarcity of fly ash and slag in the United States. However, comprehensive studies on the freeze–thaw (FT) resistance and air void system of mixtures containing GP are lacking. Therefore, this study aimed to evaluate GP’s effect on FT resistance and characterize mixtures with different GP contents, both macro- and microscopically. In this study, six concrete mixes were considered: Three mixes with 20%, 30% and 40% GP as cement replacements and two other comparable mixes with 30% fly ash and 40% slag, as well as a mix with 100% Ordinary Portland cement (OPC) as a reference. Concrete samples were prepared, cured and tested according to the ASTM standards for accelerated FT resistance for 1000 cycles and corresponding dynamic modulus of elasticity (Ed). All the samples showed minimal deterioration and scaling and high F/T resistance with a durability factor of over 90%. The relationships among FT resistance parameters, air-pressured method measurements of fresh concretes and air void analysis parameters of hardened concretes were examined in this study. X-ray micro-tomography (micro-CT scan) was used to evaluate micro-cracks development after 1000 freeze–thaw cycles and to determine spatial parameters of air voids in the concretes. Pore structure properties obtained from mercury intrusion porosimetry (MIP) and N2 adsorption method showed refined pore structure for higher cement replacement with GP, indicating more gel formation (C-S-H) which was verified by thermogravimetric analysis (TGA).

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Enhanced Water Resistance of Recycled Newspaper/High Density Polyethylene Composite Laminates via Hydrophobic Modification of Newspaper Laminas

Polymers ◽

10.3390/polym13030421 ◽

2021 ◽

Vol 13 (3) ◽

pp. 421

Author(s):

Binwei Zheng ◽

Weiwei Zhang ◽

Litao Guan ◽

Jin Gu ◽

Dengyun Tu ◽

...

Keyword(s):

Stearic Acid ◽

Photoelectron Spectroscopy ◽

Composite Laminates ◽

High Density Polyethylene ◽

Water Resistance ◽

Laminated Composite ◽

High Strength ◽

High Water ◽

High Density ◽

X Ray

A high strength recycled newspaper (NP)/high density polyethylene (HDPE) laminated composite was developed using NP laminas as reinforcement and HDPE film as matrix. Herein, NP fiber was modified with stearic acid (SA) to enhance the water resistance of the NP laminas and NP/HDPE composite. The effects of heat treatment and SA concentration on the water resistance and tensile property of NP and composite samples were investigated. The chemical structure of the NP was characterized with X-ray diffractometer, X-ray photoelectron spectroscopy and attenuated total reflectance Fourier transform infrared spectra techniques. The surface and microstructure of the NP sheets were observed by scanning electron microscopy. An expected high-water resistance of NP sheets was achieved due to a chemical bonding that low surface energy SA were grafted onto the modified NP fibers. Results showed that the hydrophobicity of NP increased with increasing the stearic acid concentration. The water resistance of the composite laminates was depended on the hydrophobicity of the NP sheets. The lowest value of 2 h water absorption rate (3.3% ± 0.3%) and thickness swelling rate (2.2% ± 0.4%) of composite were obtained when the SA concentration was 0.15 M. In addition, the introduction of SA can not only enhance the water resistance of the composite laminates, but also reduce the loss of tensile strength in wet conditions, which shows potential in outdoor applications.

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Improvement of the Properties of Polyethylene with Chlorinated Polyethylene (CPE)

Polymers and Polymer Composites ◽

10.1177/096739110301100206 ◽

2003 ◽

Vol 11 (2) ◽

pp. 115-122

Author(s):

Kálmán Marossy ◽

Pál Bárczy

Keyword(s):

High Density Polyethylene ◽

Industrial Applications ◽

Mechanical Tests ◽

High Density ◽

Structural Units ◽

Chlorinated Polyethylene ◽

X Ray ◽

Dynamic Mechanical ◽

X Ray Scattering ◽

Multiphase Systems

Blends of high density polyethylene (HDPE) and chlorinated polyethylene (CPE) have been tested across the whole concentration range. Polyethylene is used to modify the properties of CPE in the elastomer industry, but modification of the properties of polyethylene with CPE is still not usual. Conventional mechanical tests and dynamic mechanical tests were carried out. The blends were found to be multiphase systems of excellent technological compatibility. Between 10 and 15% by weight CPE increased the modulus of polyethylene. X-ray scattering studies showed that the blends contained structural units not present either in the polyethylene or in the CPE. The blends were melt processable and may have industrial applications, too.

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A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography

Zootaxa ◽

10.11646/zootaxa.2742.1.4 ◽

2011 ◽

Vol 2742 (1) ◽

pp. 60 ◽

Cited By ~ 17

Author(s):

DAVID PENNEY ◽

ANDREW MCNEIL ◽

DAVID I. GREEN ◽

ROBERT BRADLEY ◽

YURI M. MARUSIK ◽

...

Keyword(s):

New Species ◽

Phase Contrast ◽

Baltic Amber ◽

X Ray ◽

The Family ◽

X Ray Computed ◽

Micro Tomography ◽

The Baltic ◽

A New Species ◽

Eocene Amber

A new species of the extant spider family Anapidae is described from a fossil mature male in Eocene amber from the Baltic region and tentatively assigned to the genus Balticoroma Wunderlich, 2004. Phase contrast X-ray computed micro-tomography was used to reveal important features that were impossible to view using traditional microscopy. Balticoroma wheateri new species is easily diagnosed from all other anapids by having clypeal extensions that run parallel to the ectal surface of the chelicerae and in having the metatarsus of the first leg highly reduced and modified into what is presumably a y-shaped clasping structure. Although only a single extant anapid species occurs in northern Europe, the family was diverse in the Eocene. The discovery of yet another anapid species in Baltic amber supports the idea that Eocene European forests may have been a hotspot of evolution for this family of spiders.

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