scholarly journals Ineducable us: the applications and contexts of microscopy used for the characterisation of historic building materials

2017 ◽  
Vol 2 ◽  
pp. 136-144
Author(s):  
John Hughes
Keyword(s):  
Cultural Heritage ◽  
Building Materials ◽  
Materials Science ◽  
Light And Electron Microscopy ◽  
Three Dimensional ◽  
Scientific Work ◽  
Advanced Materials ◽  
Communication Problems ◽  
Transmission Electron ◽  
Historic Structures

The analysis by microscopy of the compositions and microstructures of geomaterials found in historic structures and buildings is integral to archaeological, art-historical, conservation and restoration-related investigations, and supports decision making for material replacement and repair. In archaeology there is a need to elucidate past social, economic and technological processes, and to understand the environmental impacts of past human activities related to materials use. Standard light and electron microscopy are most commonly employed, but high resolution methods such as transmission electron and three-dimensional tomography such as µ-CT are also being used. Experimental and novel developments, where they overlap with advanced materials science, are uncommon. The application of scientific characterisation frames cultural heritage value, reinforcing our understanding of authenticity and integrity. Characterisation is constrained, in turn, by the values system that operates in cultural heritage. International charters and conservation philosophy necessitate the application of science to contextualising conservation. However, the appearance of science in heritage work has also led to the performance of science for its own sake (‘endoscience’, sensu Muñoz Viñas, Contemporary Theory of Conservation, Routledge, 2011). This moves some to suggest that there is a disconnect between scientific work and its practical value. Apparent communication problems between scientists applying microscopy and other stakeholders require changes to management of material characterisation in heritage projects.

Atom Probe Microscopy and its Future

1994 ◽  
Vol 332 ◽  
Author(s):  
T. F. Kelly ◽  
P. P. Camus ◽  
D. J. Larson ◽  
L. M. Holzman
Keyword(s):  
Materials Science ◽  
Three Dimensional ◽  
Atom Probe ◽  
Atomic Level ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Probe Field ◽  
Transmission Electron ◽  
Indispensable Tool ◽  
3D Information

ABSTRACTMuch of the current activity and excitement in materials science involves processing and understanding materials at the atomic scale. Accordingly, it is necessary for materials scientists to control and characterize materials at the atomic level. There are only a few microscopies that are capable of providing information about the structure of materials at the atomic level: the atom probe field ion microscope, the high resolution transmission electron microscope, and the scanning tunneling microscope. The three-dimensional atom probe (3DAP) determines the 3D location and elemental identity of each atom in a sample. It is the only technique that provides 3D information at the atomic scale.The origin and underlying concepts behind the 3DAP are described. Several examples of actual images from existing 3DAPs are shown with emphasis on nanometer-scale analysis. Current limitations of the technique and expected future developments in this form of microscopy are described. It is our opinion that 3D atomic-scale imaging will be an indispensable tool in materials science in the coming decades.

scholarly journals Recent Advances in Multicellular Tumor Spheroid Generation for Drug Screening

Biosensors ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 445
Author(s):  
Kwang-Ho Lee ◽  
Tae-Hyung Kim
Keyword(s):  
Drug Screening ◽  
Materials Science ◽  
Three Dimensional ◽  
Tumor Model ◽  
Advanced Materials ◽  
Multicellular Spheroids ◽  
Multicellular Tumor Spheroid ◽  
Spheroid Culture ◽  
Drug Candidates ◽  
Cancer Spheroids

Multicellular tumor spheroids (MCTs) have been employed in biomedical fields owing to their advantage in designing a three-dimensional (3D) solid tumor model. For controlling multicellular cancer spheroids, mimicking the tumor extracellular matrix (ECM) microenvironment is important to understand cell–cell and cell–matrix interactions. In drug cytotoxicity assessments, MCTs provide better mimicry of conventional solid tumors that can precisely represent anticancer drug candidates’ effects. To generate incubate multicellular spheroids, researchers have developed several 3D multicellular spheroid culture technologies to establish a research background and a platform using tumor modelingvia advanced materials science, and biosensing techniques for drug-screening. In application, drug screening was performed in both invasive and non-invasive manners, according to their impact on the spheroids. Here, we review the trend of 3D spheroid culture technology and culture platforms, and their combination with various biosensing techniques for drug screening in the biomedical field.

Laboratory-Based Cryogenic Soft X-Ray Tomography with Correlative Cryo-Light and Electron Microscopy

2013 ◽  
Vol 19 (1) ◽  
pp. 22-29 ◽  
Author(s):  
David B. Carlson ◽  
Jeff Gelb ◽  
Vadim Palshin ◽  
James E. Evans
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Three Dimensional ◽  
Test Sample ◽  
X Ray ◽  
Whole Cells ◽  
Correlative Imaging ◽  
Transmission Electron ◽  
Cumulative Radiation Dose ◽  
Fluorescence Light

AbstractHere we present a novel laboratory-based cryogenic soft X-ray microscope for whole cell tomography of frozen hydrated samples. We demonstrate the capabilities of this compact cryogenic microscope by visualizing internal subcellular structures of Saccharomyces cerevisiae cells. The microscope is shown to achieve better than 50 nm half-pitch spatial resolution with a Siemens star test sample. For whole biological cells, the microscope can image specimens up to 5 μm thick. Structures as small as 90 nm can be detected in tomographic reconstructions following a low cumulative radiation dose of only 7.2 MGy. Furthermore, the design of the specimen chamber utilizes a standard sample support that permits multimodal correlative imaging of the exact same unstained yeast cell via cryo-fluorescence light microscopy, cryo-soft X-ray microscopy, and cryo-transmission electron microscopy. This completely laboratory-based cryogenic soft X-ray microscope will enable greater access to three-dimensional ultrastructure determination of biological whole cells without chemical fixation or physical sectioning.

Biomimetic synthesis of two different types of renewable cellulosic nanomaterials for scaffolding in tissue engineering

2018 ◽  
Vol 7 (3) ◽  
pp. 181-190
Author(s):  
Parisa Pooyan ◽  
Luke P. Brewster ◽  
Rina Tannenbaum ◽  
Hamid Garmestani
Keyword(s):  
Tissue Engineering ◽  
Materials Science ◽  
Three Dimensional ◽  
Biomimetic Synthesis ◽  
Advanced Materials ◽  
Cellulose Nanowhiskers ◽  
Cellulose Acetate Propionate ◽  
Different Types ◽  
Biomimetic Approach

Abstract As a rapidly growing area in materials design, the biomimetic approach at the frontier between biology and materials science aims to introduce advanced materials with structural diversities and functional versatilities by mimicking remarkable systems available in nature. Inspired by the fascinating nanostructured assembly existing in the cell walls of different plant species, we designed two fully bio-based green nanomaterials reinforced with renewable polysaccharide nanoparticles in the form of cellulose nanowhiskers (CNWs). In our initial design, the CNWs were incorporated into a cellulose acetate propionate matrix to form a bionanocomposite film, while in the second design the CNWs were entangled within a network of a collagenous medium to introduce a bionanocomposite hydrogel. Tensile and rheological measurements were carried out to study the system’s deformation as subjected to axial force or oscillatory shear. Biocompatibility was tested via incubation of human bone marrow-derived mesenchymal stem cells in vitro. Careful control of the processing conditions resulted in a three-dimensional rigid CNW network percolating within both biopolymer matrices, giving rise to an excellent performance at only a small fraction of CNWs at 3 wt.%. This study reveals that the fully bio-based green nanomaterials with enhanced mechanical percolation could construct a suitable platform for scaffolding in tissue engineering.

scholarly journals Three-dimensional nanostructure of an intact microglia cell

2018 ◽  
Author(s):  
Giulia Bolasco ◽  
Laetitia Weinhard ◽  
Tom Boissonnet ◽  
Ralph Neujahr ◽  
Cornelius T. Gross
Keyword(s):  
Electron Microscopy ◽  
Cell Biology ◽  
Light And Electron Microscopy ◽  
Three Dimensional ◽  
Microglia Cell ◽  
Cell Structures ◽  
Transmission Electron ◽  
Morphological Criteria ◽  
Membrane Protrusions ◽  
Microscopy Techniques

Microglia are non-neuronal cells of the myeloid lineage that invade and take up long-term residence in the brain during development (Ginhoux et al. 2010) and are increasingly implicated in neuronal maturation, homeostasis, and pathology (Bessis et al. 2007; Paolicelli et al. 2011; Li et al. 2012; Aguzzi et al. 2013, Cunningham 2013, Cunningham et al. 2013). Since the early twentieth century several methods for staining and visualizing microglia have been developed. Scientists in Ramón y Cajal’s group (Achúcarro 1913, Río-Hortega 1919) pioneered these methods and their work led to the christening of microglia as the third element of the nervous system, distinct from astrocytes and neurons. More recently, a combination of imaging, genetic, and immunological tools has been used to visualize microglia in living brain (Davalos et al. 2005; Nimmerjahn et al. 2005). It was found that microglia are highly motile under resting conditions and rapidly respond to injuries (Kettenmann et al. 2011) suggesting a role for microglia in both brain homeostasis and pathology. Transmission Electron microscopy (TEM) has provided crucial complementary information on microglia morphology and physiology but until recently EM analyses have been limited to single or limited serial section studies (Tremblay et al. 2010; Paolicelli et al. 2011; Schafer et al. 2012; Tremblay et al. 2012; Sipe et al. 2016). TEM studies were successful in defining a set of morphological criteria for microglia: a polygonal nucleus with peripheral condensed chromatin, a relatively small cytoplasm with abundant presence of rough endoplasmic reticulum (RER), and a large volume of lysosomes and inclusions in the perikaryon. Recent advances in volumetric electron microscopy techniques allow for 3D reconstruction of large samples at nanometer-resolution, thus opening up new avenues for the understanding of cell biology and architecture in intact tissues. At the same time, correlative light and electron microscopy (CLEM) techniques have been extended to 3D brain samples to help navigate and identify critical molecular landmarks within large EM volumes (Briggman and Denk 2006; Maco et al. 2013; Blazquez-Llorca et al. 2015, Bosch et al. 2015). Here we present the first volumetric ultrastructural reconstruction of an entire mouse hippocampal microglia using serial block face scanning electron microscopy (SBEM). Using CLEM we have ensured the inclusion of both large, small, and filopodial microglia processes. Segmentation of the dataset allowed us to carry out a comprehensive inventory of microglia cell structures, including vesicles, organelles, membrane protrusions, and processes. This study provides a reference that can serve as a data mining resource for investigating microglia cell biology.

scholarly journals Biological Applications at the Cutting Edge of Cryo-Electron Microscopy

2018 ◽  
Vol 24 (4) ◽  
pp. 406-419 ◽  
Author(s):  
Rebecca S. Dillard ◽  
Cheri M. Hampton ◽  
Joshua D. Strauss ◽  
Zunlong Ke ◽  
Deanna Altomara ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Electron Microscopy ◽  
Sample Preparation ◽  
Light And Electron Microscopy ◽  
Three Dimensional ◽  
Biological Applications ◽  
Preparation Methods ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
Phase Plates

AbstractCryo-electron microscopy (cryo-EM) is a powerful tool for macromolecular to near-atomic resolution structure determination in the biological sciences. The specimen is maintained in a near-native environment within a thin film of vitreous ice and imaged in a transmission electron microscope. The images can then be processed by a number of computational methods to produce three-dimensional information. Recent advances in sample preparation, imaging, and data processing have led to tremendous growth in the field of cryo-EM by providing higher resolution structures and the ability to investigate macromolecules within the context of the cell. Here, we review developments in sample preparation methods and substrates, detectors, phase plates, and cryo-correlative light and electron microscopy that have contributed to this expansion. We also have included specific biological applications.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Effect of Contraceptive Steroids on the Endometrium of Guinea Pig: SEM study

1977 ◽  
Vol 35 ◽  
pp. 668-669
Author(s):  
Mai M. Said ◽  
Ramesh K. Nayak ◽  
Randall E. McCoy
Keyword(s):  
Guinea Pig ◽  
Reproductive Tract ◽  
Three Dimensional ◽  
Female Reproductive Tract ◽  
Human Female ◽  
Surface Ultrastructure ◽  
Transmission Electron ◽  
Sem Study ◽  
Uterine Mucosa ◽  
Group 1

Burgos and Wislocki described changes in the mucosa of the guinea pig uterus, cervix and vagina during the estrous cycle investigated by transmission electron microscopy. More recently, Moghissi and Reame reported the effects of progestational agents on the human female reproductive tract. They found drooping and shortening of cilia in norgestrel and norethindrone- treated endometria. To the best of our knowledge, no studies concerning the effects of mestranol and norethindrone given concurrently on the three-dimensional surface features on the uterine mucosa of the guinea pig have been reported. The purpose of this study was to determine the effect of mestranol and norethindrone on surface ultrastructure of guinea pig uterus by SEM.Seventy eight animals were used in this study. They were allocated into two groups. Group 1 (20 animals) was injected intramuscularly 0.1 ml vegetable oil and served as controls.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

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