Multiscale Characterization of the Ultrastructure of Normal and Osteoporotic Human Trabecular Bone

2002 ◽  
Author(s):  
Matthew A. Rubin ◽  
Iwona Jasiuk
Keyword(s):  
Electron Microscopy ◽  
Trabecular Bone ◽  
Hierarchical Structure ◽  
Lamellar Structure ◽  
Inbred Mice ◽  
Osteoporotic Bone ◽  
Human Trabecular Bone ◽  
Transmission Electron ◽  
The Hierarchical Structure ◽  
Means Of Transmission

In this paper we characterized hierarchical structure of healthy and osteoporotic human trabecular bone from microscale down to nanoscale. To characterize the hierarchical structure, trabecular bone was investigated at the microstructural level (i.e. trabecula, trabecular packets), sub-microstructural level (lamellar structure) and the nanostructural level (crystal-collagen collagen composite). There was an emphasis on evaluating the sub-microstructure and nanostructure of trabecular bone since detailed descriptions of the lamellar structure and of the crystal-collagen relationship in osteoporotic bone are relatively unknown. The ultrastructure of healthy and osteoporotic human trabecular bone was characterized experimentally by means of transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The experiments also involved studying trabecular bone from C57BL/6J and C3H/HeJ mice. These mice have nearly the same size and weight, but have very different bone density. Thus, they were good candidates for a comparative study of healthy and osteoporotic human trabecular bone. TEM and SEM were used to characterize the hierarchical microstructure of trabecular bone in the inbred mice. The understanding of the hierarchical nature of healthy and osteoporotic bone microstructure is needed for a deeper understanding of the state of bone health and its mechanical properties.

scholarly journals The Transport System of Nacre Components through the Surface Membrane of Gastropods

2016 ◽  
Vol 672 ◽  
pp. 103-112 ◽  
Author(s):  
Elena Macías-Sánchez ◽  
Antonio G. Checa ◽  
Marc G. Willinger
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Calcium Carbonate ◽  
Lamellar Structure ◽  
Surface Membrane ◽  
Organic Matrix ◽  
X Ray ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Electron Energy Loss

The surface membrane is a lamellar structure exclusive of gastropods that is formed during the shell secretion. It protects the surface of the growing nacre and it is located between the mantle epithelium and the mineralization compartment. At the mantle side of the surface membrane numerous vesicles provide material, and at the nacre side, the interlamellar membranes detach from the whole structure. Components of nacre (glycoproteins, polysaccharides and calcium carbonate) cross the structure to reach the mineralization compartment, but the mechanism by which this occurs is still unknown. In this paper we have investigated the ultrastructure of the surface membrane and the associated vesicle layer by means of Transmission Electron Microscopy. Electron Energy Loss Spectroscopy and Energy-dispersive X-ray Spectroscopy were used for elemental analysis. The analyses revealed the concentration of calcium in the studied structures: vesicles, surface membrane, and interlamellar membranes. We discuss the possible linkage of calcium to the organic matrix.

TEM Observations of Precipitation of Coherent L12 and D022 Ordered Phases in Ni-V-Ge Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 2365-2368 ◽  
Author(s):  
Yusuke Inuzuka ◽  
Shogo Ito ◽  
Takao Kozakai ◽  
Minoru Doi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Lamellar Structure ◽  
Supersaturated Solid Solution ◽  
Early Stage ◽  
Phase Separations ◽  
Transmission Electron ◽  
Ordered Phases ◽  
Means Of Transmission

Phase separations of A1 (γ) supersaturated solid solution into γ, cubic-L12 (γ') and tetragonal-D022 (γ") phases were investigated in Ni-V-Ge alloys by means of transmission electron microscopy (TEM). When Ni-15.8at%V-9.0at%Ge alloy is aged at 1073 K, at the early stage of ageing γ" phases are observed in the γ matrix as triangle- or diamond-shaped precipitates. With further ageing, colonies of lamellar structure consisting of two variants of γ" phase are dispersedly formed in the γ matrix and then γ" plates grow along the <110> direction. When Ni-14.5at%V-8.8.at%Ge alloy is isothermally annealed at 1023 K, first spherical γ' particles precipitate homogeneously in the γ matrix, followed by the formation of lamellar structure of γ" phases. In the course of further ageing, the lamellar structure develops, and only γ' particles around the lamellar structure grow and others gradually fade out.

Synthesis and Characterisation of Hierarchically Porous HZSM-5 as Catalysts for the Synthesis of 2,3,5-Trimethyl-1,4-benzoquinone

2017 ◽  
Vol 70 (6) ◽  
pp. 691 ◽  
Author(s):  
Yu Shen ◽  
Fumin Wang ◽  
Chaoqun Yang ◽  
Xubin Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Hierarchical Structure ◽  
N2 Adsorption ◽  
Transmission Electron ◽  
The Hierarchical Structure ◽  
Adsorption Desorption

Hierarchical HZSM-5 were synthesised by controlled desilication in alkaline medium and characterised by field-emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, inductively coupled plasma–atomic emission spectrometry, N2 adsorption–desorption, and Fourier transform infrared spectroscopy. The catalytic performance of HZSM-5 towards the selective oxidation of 2,3,6-trimethylphenol by H2O2 was evaluated. Recyclability tests were also carried out. The results showed that 2,3,5-trimethyl-1,4-benzoquinone was produced in high yields (i.e. 90 %), corresponding to a 2,3,6-trimethylphenol percentage of 98 %. The N2 adsorption–desorption and XRD studies suggested that mesopores with an average size of 5 nm were produced and that the structural character of HZSM-5 was preserved after desilication. Transmission electron microscopy analysis of the spent catalyst indicated good stability of the hierarchical structure. The Fourier transform infrared spectroscopy studies revealed the development of acid sites. The combined results suggested that the nature of the solvent, intrinsic acidity, and shape selectivity of the hierarchical structure of the catalyst ensured high catalytic properties.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Structural Properties of Amorphous Silicon Produced by Electron Irradiation

1999 ◽  
Vol 557 ◽  
Author(s):  
J. Yamasaki ◽  
S. Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Distribution Function ◽  
Structural Properties ◽  
Electron Irradiation ◽  
Low Temperatures ◽  
Crystalline Silicon ◽  
Transmission Electron ◽  
Amorphous Si ◽  
Means Of Transmission

AbstractThe structural properties of the amorphous Si (a-Si), which was created from crystalline silicon by 2 MeV electron irradiation at low temperatures about 25 K, are examined in detail by means of transmission electron microscopy and transmission electron diffraction. The peak positions in the radial distribution function (RDF) of the a-Si correspond well to those of a-Si fabricated by other techniques. The electron-irradiation-induced a-Si returns to crystalline Si after annealing at 550°C.

scholarly journals A comparative study on the VOCs sensing behaviors of various ZnO nanostructures

2020 ◽  
Vol 9 (4) ◽  
pp. 117-122
Author(s):  
Vuong Nguyen Minh ◽  
Dung Dinh Tien ◽  
Hieu Hoang Nhat ◽  
Nghia Nguyen Van ◽  
Truong Nguyen Ngoc Khoa ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hierarchical Structure ◽  
Hydrothermal Process ◽  
Zno Nanostructures ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
Electrospinning Technique ◽  
Transmission Electron ◽  
Volatile Organic ◽  
Wet Chemical

The volatile organic compounds (VOCs) sensing layers were studied using ZnO nanomaterials with different morphologies including hierarchical nanostructure (ZnO-H), nanorods (ZnO-NRs), commercial nanoparticles (ZnO-CNPs) and wet chemical synthesized nanoparticles (ZnO-HNPs). ZnO hierarchical structure was fabricated by an electrospinning technique followed by hydrothermal process. ZnO vertical nanorods structure was fabricated by hydrothermal method, while ZnO nanoparticles based sensors were prepared from commercial powder and wet chemical method. The morphology and properties of the fabricated samples were examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). VOCs sensing responses toward acetone, ethanol and methanol with respect to altered ZnO nanostructureswas systematically compared at different working temperatures. The enhanced response at low working temperatures induced by theopen space hierarchical structure was observed. The VOCs sensing mechanisms of the ZnO nanostructures based sensing layer were also explained and discussed in detail. 

scholarly journals EM∩IM: software for relating ion mobility mass spectrometry and electron microscopy data

The Analyst ◽  
2016 ◽  
Vol 141 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Matteo T. Degiacomi ◽  
Justin L. P. Benesch
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Structural Biology ◽  
Cross Sections ◽  
Ion Mobility ◽  
Ion Mobility Mass Spectrometry ◽  
Density Maps ◽  
Transmission Electron ◽  
Microscopy Data ◽  
Means Of Transmission

EM∩IM enables the calculation of collision cross-sections from electron density maps obtained, for example, by means of transmission electron microscopy. This capability will further aid the integration of ion mobility mass spectrometry with modern structural biology.

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