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Sample records for block-face scanning electron

  1. Reporting methods for processing and analysis of data from serial block face scanning electron microscopy.

    Science.gov (United States)

    Borrett, S; Hughes, L

    2016-07-01

    Serial block face scanning electron microscopy is rapidly becoming a popular tool for collecting large three-dimensional data sets of cells and tissues, filling the resolution and volume gap between fluorescence microscopy and high-resolution electron microscopy. The automated collection of data within the instrument occupies the smallest proportion of the time required to prepare and analyse biological samples. It is the processing of data once it has been collected that proves the greatest challenge. In this review we discuss different methods that are used to process data. We suggest potential workflows that can be used to facilitate the transfer of raw image stacks into quantifiable data as well as propose a set of criteria for reporting methods for data analysis to enable replication of work. PMID:26800017

  2. 3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy.

    Science.gov (United States)

    Hashimoto, Teruo; Thompson, George E; Zhou, Xiaorong; Withers, Philip J

    2016-04-01

    Mechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems. PMID:26855205

  3. 3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy.

    Science.gov (United States)

    Hashimoto, Teruo; Thompson, George E; Zhou, Xiaorong; Withers, Philip J

    2016-04-01

    Mechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems.

  4. Serial block face scanning electron microscopy for the study of cardiac muscle ultrastructure at nanoscale resolutions.

    Science.gov (United States)

    Pinali, Christian; Kitmitto, Ashraf

    2014-11-01

    Electron microscopy techniques have made a significant contribution towards understanding muscle physiology since the 1950s. Subsequent advances in hardware and software have led to major breakthroughs in terms of image resolution as well as the ability to generate three-dimensional (3D) data essential for linking structure to function and dysfunction. In this methodological review we consider the application of a relatively new technique, serial block face scanning electron microscopy (SBF-SEM), for the study of cardiac muscle morphology. Employing SBF-SEM we have generated 3D data for cardiac myocytes within the myocardium with a voxel size of ~15 nm in the X-Y plane and 50 nm in the Z-direction. We describe how SBF-SEM can be used in conjunction with selective staining techniques to reveal the 3D cellular organisation and the relationship between the t-tubule (t-t) and sarcoplasmic reticulum (SR) networks. These methods describe how SBF-SEM can be used to provide qualitative data to investigate the organisation of the dyad, a specialised calcium microdomain formed between the t-ts and the junctional portion of the SR (jSR). We further describe how image analysis methods may be applied to interrogate the 3D volumes to provide quantitative data such as the volume of the cell occupied by the t-t and SR membranes and the volumes and surface area of jSR patches. We consider the strengths and weaknesses of the SBF-SEM technique, pitfalls in sample preparation together with tips and methods for image analysis. By providing a 'big picture' view at high resolutions, in comparison to conventional confocal microscopy, SBF-SEM represents a paradigm shift for imaging cellular networks in their native environment. PMID:25149127

  5. Rapid specimen preparation to improve the throughput of electron microscopic volume imaging for three-dimensional analyses of subcellular ultrastructures with serial block-face scanning electron microscopy.

    Science.gov (United States)

    Thai, Truc Quynh; Nguyen, Huy Bang; Saitoh, Sei; Wu, Bao; Saitoh, Yurika; Shimo, Satoshi; Elewa, Yaser Hosny Ali; Ichii, Osamu; Kon, Yasuhiro; Takaki, Takashi; Joh, Kensuke; Ohno, Nobuhiko

    2016-09-01

    Serial block-face imaging using scanning electron microscopy enables rapid observations of three-dimensional ultrastructures in a large volume of biological specimens. However, such imaging usually requires days for sample preparation to reduce charging and increase image contrast. In this study, we report a rapid procedure to acquire serial electron microscopic images within 1 day for three-dimensional analyses of subcellular ultrastructures. This procedure is based on serial block-face with two major modifications, including a new sample treatment device and direct polymerization on the rivets, to reduce the time and workload needed. The modified procedure without uranyl acetate can produce tens of embedded samples observable under serial block-face scanning electron microscopy within 1 day. The serial images obtained are similar to the block-face images acquired by common procedures, and are applicable to three-dimensional reconstructions at a subcellular resolution. Using this approach, regional immune deposits and the double contour or heterogeneous thinning of basement membranes were observed in the glomerular capillary loops of an autoimmune nephropathy model. These modifications provide options to improve the throughput of three-dimensional electron microscopic examinations, and will ultimately be beneficial for the wider application of volume imaging in life science and clinical medicine. PMID:26867664

  6. Serial block face-scanning electron microscopy: a tool for studying embryonic development at the cell-matrix interface.

    Science.gov (United States)

    Starborg, Tobias; Kadler, Karl E

    2015-03-01

    Studies of gene regulation, signaling pathways, and stem cell biology are contributing greatly to our understanding of early embryonic vertebrate development. However, much less is known about the events during the latter half of embryonic development, when tissues comprising mostly extracellular matrix (ECM) are formed. The matrix extends far beyond the boundaries of individual cells and is refractory to study by conventional biochemical and molecular techniques; thus major gaps exist in our knowledge of the formation and three-dimensional (3D) organization of the dense tissues that form the bulk of adult vertebrates. Serial block face-scanning electron microscopy (SBF-SEM) has the ability to image volumes of tissue containing numerous cells at a resolution sufficient to study the organization of the ECM. Furthermore, whereas light microscopy was once relatively straightforward and electron microscopy was performed in specialist laboratories, the tables are turned; SBF-SEM is relatively straightforward and is becoming routine in high-end resolution studies of embryonic structures in vivo. In this review, we discuss the emergence of SBF-SEM as a tool for studying embryonic vertebrate development.

  7. Cardiac Myocyte Diversity and a Fibroblast Network in the Junctional Region of the Zebrafish Heart Revealed by Transmission and Serial Block-Face Scanning Electron Microscopy

    KAUST Repository

    Lafontant, Pascal J.

    2013-08-23

    The zebrafish has emerged as an important model of heart development and regeneration. While the structural characteristics of the developing and adult zebrafish ventricle have been previously studied, little attention has been paid to the nature of the interface between the compact and spongy myocardium. Here we describe how these two distinct layers are structurally and functionally integrated. We demonstrate by transmission electron microscopy that this interface is complex and composed primarily of a junctional region occupied by collagen, as well as a population of fibroblasts that form a highly complex network. We also describe a continuum of uniquely flattened transitional cardiac myocytes that form a circumferential plate upon which the radially-oriented luminal trabeculae are anchored. In addition, we have uncovered within the transitional ring a subpopulation of markedly electron dense cardiac myocytes. At discrete intervals the transitional cardiac myocytes form contact bridges across the junctional space that are stabilized through localized desmosomes and fascia adherentes junctions with adjacent compact cardiac myocytes. Finally using serial block-face scanning electron microscopy, segmentation and volume reconstruction, we confirm the three-dimensional nature of the junctional region as well as the presence of the sheet-like fibroblast network. These ultrastructural studies demonstrate the previously unrecognized complexity with which the compact and spongy layers are structurally integrated, and provide a new basis for understanding development and regeneration in the zebrafish heart. © 2013 Lafontant et al.

  8. Analysis of Brain Mitochondria Using Serial Block-Face Scanning Electron Microscopy.

    Science.gov (United States)

    Mukherjee, Konark; Clark, Helen R; Chavan, Vrushali; Benson, Emily K; Kidd, Grahame J; Srivastava, Sarika

    2016-01-01

    Human brain is a high energy consuming organ that mainly relies on glucose as a fuel source. Glucose is catabolized by brain mitochondria via glycolysis, tri-carboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS) pathways to produce cellular energy in the form of adenosine triphosphate (ATP). Impairment of mitochondrial ATP production causes mitochondrial disorders, which present clinically with prominent neurological and myopathic symptoms. Mitochondrial defects are also present in neurodevelopmental disorders (e.g. autism spectrum disorder) and neurodegenerative disorders (e.g. amyotrophic lateral sclerosis, Alzheimer's and Parkinson's diseases). Thus, there is an increased interest in the field for performing 3D analysis of mitochondrial morphology, structure and distribution under both healthy and disease states. The brain mitochondrial morphology is extremely diverse, with some mitochondria especially those in the synaptic region being in the range of information on mitochondrial number, volume, size and distribution in a defined brain region. Since the obtained image resolution is high (typically under 10 nm) any gross mitochondrial morphological defects may also be detected. PMID:27501303

  9. Scanning ultrafast electron microscopy

    OpenAIRE

    Yang, Ding-Shyue; Mohammed, Omar F.; Zewail, Ahmed H.

    2010-01-01

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for whic...

  10. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  11. Scanning electron microscopy of biomaterials

    OpenAIRE

    McKinlay, K.J.; Scotchford, C A; Grant, D M; Oliver, J M; King, John R.; Brown, Paul D.

    2004-01-01

    A comparison of conventional high vacuum scanning electron microscopy (HVSEM), environmental SEM (ESEM) and confocal laser scanning microscopy (CLSM) in the assessment of cell-material interactions is made. The processing of cells cultured for conventional HVSEM leads to the loss of morphological features that are retained when using ESEM. The use of ESEM in conjunction with CLSM of the labeled cytoskeleton gives an indication of changes to the cell morphology as a consequence of incubation t...

  12. A fluorescence scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Takaaki Kanemaru

    2010-01-01

    Full Text Available Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM and an electron microscope (EM. In the current study, a scanning electron microscope (SEM (JEOL JXA8600 M was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM. In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

  13. Control on Electron Beam Scanning Track

    Institute of Scientific and Technical Information of China (English)

    王学东; 姚舜

    2004-01-01

    In order to use electron beam as a movable welding heat source and whose energy distribution along its moving trace can be controlled, a method of electron beam scanning track and scanning mode control was put forward. Based on it, the electron beam scanning track and scanning mode can be edited at will according to actual requirements, and the energy input of each point of the scanning track can be controlled. In addition, the scanning frequency and points control, real time adjusting of the scanning track etc. were explained. This method can be used in electron beam brazing, surface modification, surface heat treatment etc.

  14. Electronically-Scanned Fourier-Transform Spectrometer

    Science.gov (United States)

    Breckinridge, J. B.; Ocallaghan, F. G.

    1984-01-01

    Instrument efficient, lightweight, and stable. Fourier-transform spectrometer configuration uses electronic, instead of mechanical, scanning. Configuration insensitive to vibration-induced sampling errors introduced into mechanically scanned systems.

  15. Scanning electron microscopy - application and techniques

    International Nuclear Information System (INIS)

    The application of the scanning electron microscope, and other image forming scanning systems (STEM and the nuclear microprobe), to a range of nuclear reactor problems is described. Particular attention is given to the solution of fracture problems. Autoradiography, electron spectroscopy, and an investigation of irradiation damage in boron carbide using the transmission electron microscope are also described. (author)

  16. Proximity Scanning Transmission Electron Microscopy/Spectroscopy

    CERN Document Server

    Hwang, Ing-Shouh

    2016-01-01

    Here a new microscopic method is proposed to image and characterize very thin samples like few-layer materials, organic molecules, and nanostructures with nanometer or sub-nanometer resolution using electron beams of energies lower than 20 eV. The microscopic technique achieves high resolution through the proximity (or near-field) effect, as in scanning tunneling microscopy (STM), while it also allows detection of transmitted electrons for imaging and spectroscopy, as in scanning transmission electron microscopy (STEM). This proximity transmission electron microscopy (PSTEM) does not require any lens to focus the electron beam. It also allows detailed characterization of the interaction of low-energy electron with materials. PSTEM can operate in a way very similar to scanning tunneling microscopy, which provides high-resolution imaging of geometric and electronic structures of the sample surface. In addition, it allows imaging and characterization of the interior structures of the sample based on the detected...

  17. Electron Beam Scanning in Industrial Applications

    Science.gov (United States)

    Jongen, Yves; Herer, Arnold

    1996-05-01

    Scanned electron beams are used within many industries for applications such as sterilization of medical disposables, crosslinking of wire and cables insulating jackets, polymerization and degradation of resins and biomaterials, modification of semiconductors, coloration of gemstones and glasses, removal of oxides from coal plant flue gasses, and the curing of advanced composites and other molded forms. X-rays generated from scanned electron beams make yet other applications, such as food irradiation, viable. Typical accelerators for these applications range in beam energy from 0.5MeV to 10 MeV, with beam powers between 5 to 500kW and scanning widths between 20 and 300 cm. Since precise control of dose delivery is required in many of these applications, the integration of beam characteristics, product conveyance, and beam scanning mechanisms must be well understood and optimized. Fundamental issues and some case examples are presented.

  18. Phosphogypsum surface characterisation using scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2003-01-01

    Full Text Available This paper presents the results of application of Scanning Electron Microscopy (SEM to examinations of the samples of natural gypsum and phosphogypsum. Phosphogypsum has a well developed crystalline structure, and appear in two polymorphous forms, of rombic and hexagonal shape crystals. Natural gypsum has a poorly crystalline structure. The differences in crystalline structure influence the chemical behavior of these row materials.

  19. Application of scanning electron microscopy in catalysis

    OpenAIRE

    Lomić Gizela A.; Kiš Erne E.; Bošković Goran C.; Marinković-Nedučin Radmila P.

    2004-01-01

    A short survey of various information obtained by scanning electron microscopy (SEM) in the investigation of heterogeneous catalysts and nano-structured materials have been presented. The capabilities of SEM analysis and its application in testing catalysts in different fields of heterogeneous catalysis are illustrated. The results encompass the proper way of catalyst preparation, the mechanism of catalyst active sites formation catalysts changes and catalyst degradation during their applicat...

  20. Scanning electron microscopy of superficial white onychomycosis*

    Science.gov (United States)

    de Almeida Jr., Hiram Larangeira; Boabaid, Roberta Oliveira; Timm, Vitor; Silva, Ricardo Marques e; de Castro, Luis Antonio Suita

    2015-01-01

    Superficial white onychomycosis is characterized by opaque, friable, whitish superficial spots on the nail plate. We examined an affected halux nail of a 20-year-old male patient with scanning electron microscopy. The mycological examination isolated Trichophyton mentagrophytes. Abundant hyphae with the formation of arthrospores were found on the nail's surface, forming small fungal colonies. These findings showed the great capacity for dissemination of this form of onychomycosis. PMID:26560225

  1. [Pili annulati. A scanning electron microscopy study].

    Science.gov (United States)

    Lalević-Vasić, B; Polić, D

    1988-01-01

    A case of ringed hair studied by light and electron microscopy is reported. The patient, a 20-year old girl, had been presenting with the hair abnormality since birth. At naked eye examination the hairs were dry, 6 to 7 cm long, and they showed dull and shining areas giving the scalp hair a scintillating appearance (fig. 1). Several samples of hair were taken and examined by light microscopy under white and polarized light. Hair shafts and cryo-fractured surfaces were examined by scanning electron microscopy. RESULTS. 1. Light microscopy. Lesions were found in every hair examined. There were abnormal, opaque and fusiform areas alternating with normal areas all along the hair shaft (fig. 2). The abnormal areas resulted from intracortical air-filled cavities. Fractures similar to those of trichorrhexis nodosa were found in the opaque areas of the distal parts of the hairs. 2. Scanning electron microscopy. A. Hair shaft surface. The abnormal areas showed a longitudinal, "curtain-like" folding of the cuticular cells which had punctiform depressions on their surface and worn free edges (fig. 4, 5, 6); trichorrhexis-type fractures were seen in the distal parts of the hair shafts (fig. 7, 8). Normal areas regularly presented with longitudinal, superficial, short and non-systematized depressions (fig. 9); the cuticular cells were worn, and there were places where the denuded cortex showed dissociated cortical fibres (fig. 10).(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Scanning electron microscopy analysis of dental cements

    Directory of Open Access Journals (Sweden)

    Radosavljević Radivoje D.

    2009-01-01

    Full Text Available The aim of this study was to compare in vitro the characteristics of different types of luting cements (zinc phosphate, glass-ionomer and resin based composite cement using scanning electron microscopy (SEM analysis and microleakage for the quality range of materials. Dental cements were mixed in accordance with the manufacturer's instructions and formed with posts in dental root canals of extracted teeth. The quality of cement was determined by SEM observation on horizontal sectioned roots with fixed posts according to specific pore and marginal gap diameter. The microleakage was measured on specimens immersed in Lofler (methylene blue solution. The mean values of the maximal diameter of pores, marginal gaps and microleakage of conventional cements are remarkably larger in comparison with composite luting agents. In conclusion, the quality and efficiency of composite luting agents in comparison with conventional cements are more successful in protecting the interior of tooth from penetration of oral fluids, bacteria and bacterial toxins into unprotected dentine.

  3. Scanning electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1998-01-01

    Scanning Electron Microscopy provides a description of the physics of electron-probe formation and of electron-specimen interations The different imaging and analytical modes using secondary and backscattered electrons, electron-beam-induced currents, X-ray and Auger electrons, electron channelling effects, and cathodoluminescence are discussed to evaluate specific contrasts and to obtain quantitative information

  4. Fabrication of electron sources for a miniature scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L

    1999-10-01

    The thesis describes the fabrication of a micro field emitter, which is designed as an electron source for application in a miniature scanning electron microscope. A micro field emitter has a cathode tip, insulating layer, metal gate, sandwich structure. This structure is fabricated on a silicon substrate. The tip normally has a tenth of a nanometer apex radius, and is separated from the surrounding gate electrode by a space, ranging from sub-micron to several microns in width, where a high electric field is formed. The micro field emitter is capable of delivering electrons into the surrounding vacuum. The emitted electron current is governed by the Fowler-Nordheim theory. A new fabrication technique for producing arrays of silicon nanotips with precise control of tip size and geometry, without the need for a conventional oxidation sharpening process, was developed. Gated micro field emitter arrays were fabricated using an electron beam evaporation technique. Also volcano shaped micro field emitters were fabricated using plasma enhanced chemical vapor deposition and etch back techniques. Silicon based gated field emitters with tungsten coating, silicon carbide coating and diamond like carbide coating were produced for evaluation. Field emission studies from these micro field emitters were carried out in ultra high vacuum systems. The current/voltage characteristic, emission current stability, field emission spatial distribution, and the field emission pressure dependence were investigated. Failures of devices were investigated and the failure mechanisms were drawn out. A feedback back control circuit was designed and built to control the field emission current fluctuation and stabilized emission current from the micro field emitters was obtained. Various suggestions for developing the entire miniature scanning electron microscope are made and future work for studying the micro field emitters is proposed. (author)

  5. Dental Wear: A Scanning Electron Microscope Study

    Directory of Open Access Journals (Sweden)

    Luca Levrini

    2014-01-01

    Full Text Available Dental wear can be differentiated into different types on the basis of morphological and etiological factors. The present research was carried out on twelve extracted human teeth with dental wear (three teeth showing each type of wear: erosion, attrition, abrasion, and abfraction studied by scanning electron microscopy (SEM. The study aimed, through analysis of the macro- and micromorphological features of the lesions (considering the enamel, dentin, enamel prisms, dentinal tubules, and pulp, to clarify the different clinical and diagnostic presentations of dental wear and their possible significance. Our results, which confirm current knowledge, provide a complete overview of the distinctive morphology of each lesion type. It is important to identify the type of dental wear lesion in order to recognize the contributing etiological factors and, consequently, identify other more complex, nondental disorders (such as gastroesophageal reflux, eating disorders. It is clear that each type of lesion has a specific morphology and mechanism, and further clinical studies are needed to clarify the etiological processes, particularly those underlying the onset of abfraction.

  6. Electron optics of multi-beam scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi-Gheidari, A., E-mail: A.M.Gheidari@tudelft.nl [Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Kruit, P. [Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

    2011-07-21

    We have developed a multi-beam scanning electron microscope (MBSEM), which delivers a square array of 196 focused beams onto a sample with a resolution and current per beam comparable to a state of the art single beam SEM. It consists of a commercially available FEI Nova-nano 200 SEM column equipped with a novel multi-electron beam source module. The key challenge in the electron optical design of the MBSEM is to minimize the off-axial aberrations of the lenses. This article addresses the electron optical design of the system and presents the result of optics simulations for a specific setting of the system. It is shown that it is possible to design a system with a theoretical axial spot size of 1.2 nm at 15 kV with a probe current of 26 pA. The off-axial aberrations for the outermost beam add up 0.8 nm, increasing the probe size to 1.5 nm.

  7. The new method of electronic scanning

    OpenAIRE

    Khludneva, A.; Mikhailov, M.; Paslyon, V.

    2009-01-01

    We investigate the possibility of using the reversing mediums in the antenna engineering that gives us the ability to improve characteristics of the antenna systems; particularly we can receive the adjusted form and width of the directional diagram in the microwave range and we can also command the directional diagram while scanning within the adjusted rule.

  8. Electron-beam-assisted Scanning Tunneling Microscopy Of Insulating Surfaces

    CERN Document Server

    Bullock, E T

    2000-01-01

    Insulating materials are widely used in electronic devices. Bulk insulators and insulating films pose unique challenges for high resolution study since most commonly used charged particle surface analysis techniques are incompatible with insulating surfaces and materials. A, method of performing scanning tunneling microscopy (STM) on insulating surfaces has been investigated. The method is referred to as electron-beam assisted scanning tunneling microscopy (e-BASTM). It is proposed that by coupling the STM and the scanning electron microscopy (SEM) as one integrated device, that insulating materials may be studied, obtaining both high spatial resolution, and topographic and electronic resolution. The premise of the technique is based on two physical consequences of the interaction of an energetic electron beam (PE) with a material. First, when an electron beam is incident upon a material, low level material electrons are excited into conduction band states. For insulators, with very high secondary electron yi...

  9. Quantitative Scanning Transmission Electron Microscopy of Electronic and Nanostructured Materials

    Science.gov (United States)

    Yankovich, Andrew B.

    Electronic and nanostructured materials have been investigated using advanced scanning transmission electron microscopy (STEM) techniques. The first topic is the microstructure of Ga and Sb-doped ZnO. Ga-doped ZnO is a candidate transparent conducting oxide material. The microstructure of GZO thin films grown by MBE under different growth conditions and different substrates were examined using various electron microscopy (EM) techniques. The microstructure, prevalent defects, and polarity in these films strongly depend on the growth conditions and substrate. Sb-doped ZnO nanowires have been shown to be the first route to stable p-type ZnO. Using Z-contrast STEM, I have showed that an unusual microstructure of Sb-decorated head-to-head inversion domain boundaries and internal voids contain all the Sb in the nanowires and cause the p-type conduction. InGaN thin films and InGaN / GaN quantum wells (QW) for light emitting diodes are the second topic. Low-dose Z-contrast STEM, PACBED, and EDS on InGaN QW LED structures grown by MOCVD show no evidence for nanoscale composition variations, contradicting previous reports. In addition, a new extended defect in GaN and InGaN was discovered. The defect consists of a faceted pyramid-shaped void that produces a threading dislocation along the [0001] growth direction, and is likely caused by carbon contamination during growth. Non-rigid registration (NRR) and high-precision STEM of nanoparticles is the final topic. NRR is a new image processing technique that corrects distortions arising from the serial nature of STEM acquisition that previously limited the precision of locating atomic columns and counting the number of atoms in images. NRR was used to demonstrate sub-picometer precision in STEM images of single crystal Si and GaN, the best achieved in EM. NRR was used to measure the atomic surface structure of Pt nanoacatalysts and Au nanoparticles, which revealed new bond length variation phenomenon of surface atoms. In

  10. Probing Nanoscale Electronic and Magnetic Interaction with Scanning Tunneling Spectroscopy

    DEFF Research Database (Denmark)

    Bork, Jakob

    This thesis is concerned with fundamental research into electronic and magnetic interaction on the nanoscale. From small metallic and magnetic islands and layers to single atoms. The research revolves around magnetic interaction probed through the spectroscopic capabilities of the scanning...

  11. Collective electronic effects in scanning probe microscopy

    Science.gov (United States)

    Passian, Ali

    The surface plasmon dispersion relations are calculated for a metal coated dielectric probe above a dielectric half space with and without metal coating. Employing prolate spheroidal coordinate system this configuration was modeled as confocal single-sheeted hyperboloids of revolution superimposed on planar domains. The involved media are characterized by frequency dependent, spatially local dielectric functions. Due to subwavelength dimensions of the region of interest, nonretarded electrodynamics is utilized to derive exact analytical expressions describing the resonant surface modes. The dispersion relations are studied as functions of the parameter that defines the hyperboloidal boundaries of the tip and the corresponding coating, and as functions of the involved coating thicknesses. Both parallel and perpendicular polarizations are considered. The results are simulated numerically and limiting cases are discussed with comparison to the Cartesian thin foil case. Using this new type of probe-substrate configuration, the surface plasmon coupling mechanism is investigated experimentally utilizing a scanning probe microscope, and the signal strength acquired by the probe is measured as a function of the distance between the probe and the sample. This is repeated at three different wavelengths of the incident p-polarized photons used to stimulate surface plasmons in the thin metal foil. The results are compared with the theory. Utilizing the prolate spheroidal coordinate system, the related and relevant problem of the Coulomb interaction of a dielectric probe tip with a uniform field existing above a semiinfinite, homogeneous dielectric substrate was studied. This is of interest in atomic force microscopy when the sample surface is electrically charged. The induced polarization surface charge density and the field distribution at the bounding surface of the dielectric medium with the geometry of a single-sheeted hyperboloid of revolution located above the dielectric

  12. Electronic Scanning of UterineEndometrium in Postpartum Cow

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two postpartum cows were used to study the ultrastructural changes of uterine endometrium by using scanning electron microscope. The results showed that the process of repair of uterine endometrium after calving was demonstrated by scanning electron microscope through a series of endometrium biopsy. Some part of the endometrium was damaged after calving and its adjacent endometrium cells became necrosis and exfoliated during the first 7 days post-partum;the cilium and microvillus of the epithelial cell in the undamaged area of the endometrium disappeared. By 26 days postpartum the damaged area reduced and the cilium and microvillus increased in their numbers. The damaged tissues were all repaired by day 60 postpartum.

  13. A new clustering algorithm for scanning electron microscope images

    Science.gov (United States)

    Yousef, Amr; Duraisamy, Prakash; Karim, Mohammad

    2016-04-01

    A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with the sample atoms, producing various signals that are collected by detectors. The gathered signals contain information about the sample's surface topography and composition. The electron beam is generally scanned in a raster scan pattern, and the beam's position is combined with the detected signal to produce an image. The most common configuration for an SEM produces a single value per pixel, with the results usually rendered as grayscale images. The captured images may be produced with insufficient brightness, anomalous contrast, jagged edges, and poor quality due to low signal-to-noise ratio, grained topography and poor surface details. The segmentation of the SEM images is a tackling problems in the presence of the previously mentioned distortions. In this paper, we are stressing on the clustering of these type of images. In that sense, we evaluate the performance of the well-known unsupervised clustering and classification techniques such as connectivity based clustering (hierarchical clustering), centroid-based clustering, distribution-based clustering and density-based clustering. Furthermore, we propose a new spatial fuzzy clustering technique that works efficiently on this type of images and compare its results against these regular techniques in terms of clustering validation metrics.

  14. Surface sensitivity effects with local probe scanning Auger-scanning electron microscopy

    NARCIS (Netherlands)

    Van Agterveld, DTL; Palasantzas, G; De Hosson, JTM; Bentley, J; Allen, C; Dahmen, U; Petrov,

    2001-01-01

    Ultra-high-vacuum segregation studies on in-situ fractured Cu-Sb alloys were performed in terms of nanometer scale scanning Auger/Electron microscopy. S contamination leads to the formation Of Cu2S precipitates which, upon removal due to fracture, expose pits with morphology that depends on the prec

  15. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    OpenAIRE

    Levin, Barnaby D.A.; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D.; Richard D Robinson

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the cu...

  16. Applications of orientation mapping by scanning and transmission electron microscopy

    DEFF Research Database (Denmark)

    Juul Jensen, D.

    1997-01-01

    The potentials of orientation mapping techniques (in the following referred to as OIM) for studies of thermomechanical processes are analysed. Both transmission electron microscopy (TEM) and scanning electron microscopy (SEM) based OIM techniques are considered. Among the thermomechanical processes......, focus is on cold deformation and recrystallization processes. It is described how the OIM techniques may be applied for studies of such processes. Results of OIM measurements supplement more traditional TEM and SEM microstructure characterizations as well as bulk texture measurements, and new...

  17. Scanning tunneling spectroscopy on electron-boson interactions in superconductors

    CERN Document Server

    Schackert, Michael Peter

    2015-01-01

    This work describes the experimental study of electron-boson interactions in superconductors by means of inelastic electron tunneling spectroscopy performed with a scanning tunneling microscope (STM) at temperatures below 1 K. This new approach allows the direct measurement of the Eliashberg function of conventional superconductors as demonstrated on lead (Pb) and niobium (Nb). Preparative experiments on unconventional iron-pnictides are presented in the end.

  18. Orientation mapping of semicrystalline polymers using scanning electron nanobeam diffraction.

    Science.gov (United States)

    Panova, Ouliana; Chen, X Chelsea; Bustillo, Karen C; Ophus, Colin; Bhatt, Mahesh P; Balsara, Nitash; Minor, Andrew M

    2016-09-01

    We demonstrate a scanning electron nanobeam diffraction technique that can be used for mapping the size and distribution of nanoscale crystalline regions in a polymer blend. In addition, it can map the relative orientation of crystallites and the degree of crystallinity of the material. The model polymer blend is a 50:50w/w mixture of semicrystalline poly(3-hexylthiophene-2,5-diyl) (P3HT) and amorphous polystyrene (PS). The technique uses a scanning electron beam to raster across the sample and acquires a diffraction image at each probe position. Through image alignment and filtering, the diffraction image dataset enables mapping of the crystalline regions within the scanned area and construction of an orientation map. PMID:27323282

  19. [Scanning electron microscope study of chemically disinfected endodontic files].

    Science.gov (United States)

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made. PMID:1659857

  20. Scanning electron microscopy of ULPA and HEPA filtering papers

    International Nuclear Information System (INIS)

    The behavior of newly developed ULPA and HEPA filtering papers has been examined in an abnormal condition due to overheating up to 400 degree C. A noteworth failure in mechanical resistance has been observed, whereas efficiency was scarcely affected. Scanning electron microscopy showed that observed anticipated failures were accompanied with ruptures of the glass microfibers of the papers

  1. Preparation of Articular Cartilage Specimens for Scanning Electron Microscopy.

    Science.gov (United States)

    Stupina, T A

    2016-08-01

    We developed and adapted a technology for preparation of articular cartilage specimens for scanning electron microscopy. The method includes prefixation processing, fixation, washing, and dehydration of articular cartilage specimens with subsequent treatment in camphene and air-drying. The technological result consists in prevention of deformation of the articular cartilage structures. The method is simpler and cheaper than the known technologies. PMID:27591865

  2. [Scanning electron microscope study of chemically disinfected endodontic files].

    Science.gov (United States)

    Navarro, G; Mateos, M; Navarro, J L; Canalda, C

    1991-01-01

    Forty stainless steel endodontic files were observed at scanning electron microscopy after being subjected to ten disinfection cycles of 10 minutes each one, immersed in different chemical disinfectants. Corrosion was not observed on the surface of the files in circumstances that this study was made.

  3. New Scanning Electron Microscope Used for Cryogenic Tensile Testing

    CERN Multimedia

    Maximilien Brice

    2013-01-01

    At CERN engineering department's installation for cryogenic tensile testing, the new scanning electron microscope (SEM) allows for detailed optical observations to be carried out. Using the SEM, surface coatings and tensile properties of materials can investigated in order to better understand how they behave under different conditions.

  4. Scanning electron microscope facility for examination of radioactive materials

    International Nuclear Information System (INIS)

    An AMRAY model 1200B scanning electron microscope was modified to permit remote examination of radioactive specimens. Features of the modification include pneumatic vibration isolation of the column, motorized stage controls, improvements for monitoring vacuum, and a system for changing filaments without entering the hot cell

  5. Scanning electron microscopy of the male genitalia of Sarcophagidae (Diptera

    Directory of Open Access Journals (Sweden)

    Hugo de Souza Lopes

    1990-03-01

    Full Text Available The male genitalia of nine species of Sarcophagidae (Diptera - Goniophyto honsuensis Rohdendorf, 1962, Tricharaea brevicornis (Wiedemann, 1830, Chaetoravinia derelicta (Walker, 1852, Austrohartigia spinigena (Rondani, 1864, Chrysagria duodecimpunctata Townsend, 1935, Boettcheria bisetosa Parker, 1914, Lipoptilocnema lanei Townsend, 1934, L. crispina (Lopes, 1938 and Euboettcheria alvarengai Lopes & Tibana, 1982 - were examined by scanning electron microscope (SEM and the main morphological features are descirbed.

  6. Development of scanning electron and x-ray microscope

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Tomokazu, E-mail: tomokzau.matsumura@etd.hpk.co.jp; Hirano, Tomohiko, E-mail: tomohiko.hirano@etd.hpk.co.jp; Suyama, Motohiro, E-mail: suyama@etd.hpk.co.jp [Hamamatsu Photonics K.K., 314-5, Shimokanzo, Iwata City, Shizuoka-Pref. (Japan)

    2016-01-28

    We have developed a new type of microscope possessing a unique feature of observing both scanning electron and X-ray images under one unit. Unlike former X-ray microscopes using SEM [1, 2], this scanning electron and X-ray (SELX) microscope has a sample in vacuum, thus it enables one to observe a surface structure of a sample by SEM mode, to search the region of interest, and to observe an X-ray image which transmits the region. For the X-ray observation, we have been focusing on the soft X-ray region from 280 eV to 3 keV to observe some bio samples and soft materials. The resolutions of SEM and X-ray modes are 50 nm and 100 nm, respectively, at the electron energy of 7 keV.

  7. Adaptive noise Wiener filter for scanning electron microscope imaging system.

    Science.gov (United States)

    Sim, K S; Teh, V; Nia, M E

    2016-03-01

    Noise on scanning electron microscope (SEM) images is studied. Gaussian noise is the most common type of noise in SEM image. We developed a new noise reduction filter based on the Wiener filter. We compared the performance of this new filter namely adaptive noise Wiener (ANW) filter, with four common existing filters as well as average filter, median filter, Gaussian smoothing filter and the Wiener filter. Based on the experiments results the proposed new filter has better performance on different noise variance comparing to the other existing noise removal filters in the experiments. SCANNING 38:148-163, 2016. © 2015 Wiley Periodicals, Inc. PMID:26235517

  8. Closed-Loop Autofocus Scheme for Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    Cui Le

    2015-01-01

    Full Text Available In this paper, we present a full scale autofocus approach for scanning electron microscope (SEM. The optimal focus (in-focus position of the microscope is achieved by maximizing the image sharpness using a vision-based closed-loop control scheme. An iterative optimization algorithm has been designed using the sharpness score derived from image gradient information. The proposed method has been implemented and validated using a tungsten gun SEM at various experimental conditions like varying raster scan speed, magnification at real-time. We demonstrate that the proposed autofocus technique is accurate, robust and fast.

  9. Miniaturized Environmental Scanning Electron Microscope for In Situ Planetary Studies

    Science.gov (United States)

    Gaskin, Jessica; Abbott, Terry; Medley, Stephanie; Gregory, Don; Thaisen, Kevin; Taylor , Lawrence; Ramsey, Brian; Jerman, Gregory; Sampson, Allen; Harvey, Ralph

    2010-01-01

    The exploration of remote planetary surfaces calls for the advancement of low power, highly-miniaturized instrumentation. Instruments of this nature that are capable of multiple types of analyses will prove to be particularly useful as we prepare for human return to the moon, and as we continue to explore increasingly remote locations in our Solar System. To this end, our group has been developing a miniaturized Environmental-Scanning Electron Microscope (mESEM) capable of remote investigations of mineralogical samples through in-situ topographical and chemical analysis on a fine scale. The functioning of an SEM is well known: an electron beam is focused to nanometer-scale onto a given sample where resulting emissions such as backscattered and secondary electrons, X-rays, and visible light are registered. Raster scanning the primary electron beam across the sample then gives a fine-scale image of the surface topography (texture), crystalline structure and orientation, with accompanying elemental composition. The flexibility in the types of measurements the mESEM is capable of, makes it ideally suited for a variety of applications. The mESEM is appropriate for use on multiple planetary surfaces, and for a variety of mission goals (from science to non-destructive analysis to ISRU). We will identify potential applications and range of potential uses related to planetary exploration. Over the past few of years we have initiated fabrication and testing of a proof-of-concept assembly, consisting of a cold-field-emission electron gun and custom high-voltage power supply, electrostatic electron-beam focusing column, and scanning-imaging electronics plus backscatter detector. Current project status will be discussed. This effort is funded through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program.

  10. Low-Temperature Scanning Capacitance Probe for Imaging Electron Motion

    International Nuclear Information System (INIS)

    Novel techniques to probe electronic properties at the nanoscale can shed light on the physics of nanoscale devices. In particular, studying the scattering of electrons from edges and apertures at the nanoscale and imaging the electron profile in a quantum dot, have been of interest [1]. In this paper, we present the design and implementation of a cooled scanning capacitance probe that operates at liquid He temperatures to image electron waves in nanodevices. The conducting tip of a scanned probe microscope is held above the nanoscale structure, and an applied sample-to-tip voltage creates an image charge that is measured by a cooled charge amplifier [2] adjacent to the tip. The circuit is based on a low-capacitance, high- electron-mobility transistor (Fujitsu FHX35X). The input is a capacitance bridge formed by a low capacitance pinched-off HEMT transistor and tip-sample capacitance. We have achieved low noise level (0.13 e/VHz) and high spatial resolution (100 nm) for this technique, which promises to be a useful tool to study electronic behavior in nanoscale devices

  11. Influence of mechanical noise inside a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Gaudenzi de Faria, Marcelo; Haddab, Yassine, E-mail: yassine.haddab@femto-st.fr; Le Gorrec, Yann; Lutz, Philippe [AS2M department, FEMTO-ST Institute, Université de Franche-Comté/CNRS/ENSMM, 25000 Besançon (France)

    2015-04-15

    The scanning electron microscope is becoming a popular tool to perform tasks that require positioning, manipulation, characterization, and assembly of micro-components. However, some of these applications require a higher level of performance with respect to dynamics and precision of positioning. One limiting factor is the presence of unidentified noises and disturbances. This work aims to study the influence of mechanical disturbances generated by the environment and by the microscope, identifying how these can affect elements in the vacuum chamber. To achieve this objective, a dedicated setup, including a high-resolution vibrometer, was built inside the microscope. This work led to the identification and quantification of main disturbances and noise sources acting on a scanning electron microscope. Furthermore, the effects of external acoustic excitations were analysed. Potential applications of these results include noise compensation and real-time control for high accuracy tasks.

  12. Morphological classification of bioaerosols from composting using scanning electron microscopy

    OpenAIRE

    Tamer Vestlund, Asli; Al-Ashaab, R.; Tyrrel, Sean F.; Longhurst, Philip J.; Pollard, Simon J. T.; Drew, Gillian H

    2014-01-01

    This research classifies the physical morphology (form and structure) of bioaerosols emitted from open windrow composting. Aggregation state, shape and size of the particles captured are reported alongside the implications for bioaerosol dispersal after release. Bioaerosol sampling took place at a composting facility using personal air filter samplers. Samples were analysed using scanning electron microscopy. Particles were released mainly as small (1 μm) single cells, with aggregates occurri...

  13. SCANNING ELECTRON MICROSCOPY STUDY OF FILLED SILICONE RUBBER

    Institute of Scientific and Technical Information of China (English)

    LI Yufu; YANG Qiyun; LI Guangliang

    1988-01-01

    The fracture surfaces of a number of silicone vulcanizates were investigated by the use of scanning electron microscopy (SEM). It was found that the difference in the presence and absence of filler, the variation of its surface modification as well as the history of thermal aging of the vulcanizates, all of these factors made difference in surface morphology of the fractured surface. This was correlated with the strength of the vulcanizates. The reinforcing effect of filler and the process of fracture were discussed.

  14. Role of scanning electron microscope )SEM) in metal failure analysis

    International Nuclear Information System (INIS)

    Scanning electron microscope (SEM) is a scientific instrument that uses a beam of highly energetic electrons to examine the surface and phase distribution of specimens on a micro scale through the live imaging of secondary electrons (SE) and back-scattered electrons (BSE) images. One of the main activities of SEM Laboratory at MINT is for failure analysis on metal part and components. The capability of SEM is excellent for determining the root cause of metal failures such as ductility or brittleness, stress corrosion, fatigue and other types of failures. Most of our customers that request for failure analysis are from local petrochemical plants, manufacturers of automotive components, pipeline maintenance personnel and engineers who involved in the development of metal parts and component. This paper intends to discuss some of the technical concepts in failure analysis associated with SEM. (Author)

  15. Scanning electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1985-01-01

    The aim of this book is to outline the physics of image formation, electron­ specimen interactions, imaging modes, the interpretation of micrographs and the use of quantitative modes "in scanning electron microscopy (SEM). lt forms a counterpart to Transmission Electron Microscopy (Vol. 36 of this Springer Series in Optical Sciences) . The book evolved from lectures delivered at the University of Münster and from a German text entitled Raster-Elektronenmikroskopie (Springer-Verlag), published in collaboration with my colleague Gerhard Pfefferkorn. In the introductory chapter, the principles of the SEM and of electron­ specimen interactions are described, the most important imaging modes and their associated contrast are summarized, and general aspects of eiemental analysis by x-ray and Auger electron emission are discussed. The electron gun and electron optics are discussed in Chap. 2 in order to show how an electron probe of small diameter can be formed, how the elec­ tron beam can be blanked at high fre...

  16. Simulation and Characterization of a Miniaturized Scanning Electron Microscope

    Science.gov (United States)

    Gaskin, Jessica A.; Jerman, Gregory A.; Medley, Stephanie; Gregory, Don; Abbott, Terry O.; Sampson, Allen R.

    2011-01-01

    A miniaturized Scanning Electron Microscope (mSEM) for in-situ lunar investigations is being developed at NASA Marshall Space Flight Center with colleagues from the University of Alabama in Huntsville (UAH), Advanced Research Systems (ARS), the University of Tennessee in Knoxville (UTK) and Case Western Reserve University (CWRU). This effort focuses on the characterization of individual components of the mSEM and simulation of the complete system. SEMs can provide information on the size, shape, morphology and chemical composition of lunar regolith. Understanding these basic properties will allow us to better estimate the challenges associated with In-Situ Resource Utilization and to improve our basic science knowledge of the lunar surface (either precluding the need for sample return or allowing differentiation of unique samples to be returned to Earth.) The main components of the mSEM prototype includes: a cold field emission electron gun (CFEG), focusing lens, deflection/scanning system and backscatter electron detector. Of these, the electron gun development is of particular importance as it dictates much of the design of the remaining components. A CFEG was chosen for use with the lunar mSEM as its emission does not depend on heating of the tungsten emitter (lower power), it offers a long operation lifetime, is orders of magnitude brighter than tungsten hairpin guns, has a small source size and exhibits low beam energy spread.

  17. Advantages of environmental scanning electron microscopy in studies of microorganisms.

    Science.gov (United States)

    Collins, S P; Pope, R K; Scheetz, R W; Ray, R I; Wagner, P A; Little, B J

    1993-08-01

    Microorganisms, including bacteria, fungi, protozoa, and microalgae, are composed predominantly of water which prohibits direct observation in a traditional scanning electron microscope (SEM). Preparation for SEM requires that microorganisms be fixed, frozen or dehydrated, and coated with a conductive film before observation in a high vacuum environment. Sample preparation may mechanically disturb delicate samples, compromise morphological information, and introduce other artifacts. The environmental scanning electron microscope (ESEM) provides a technology for imaging hydrated or dehydrated biological samples with minimal manipulation and without the need for conductive coatings. Sporulating cultures of three fungi, Aspergillus sp., Cunninghamella sp., and Mucor sp., were imaged in the ESEM to assess usefulness of the instrument in the direct observation of delicate, uncoated, biological specimens. Asexual sporophores showed no evidence of conidial displacement or disruption of sporangia. Uncoated algal cells of Euglena gracilis and Spirogyra sp. were examined using the backscatter electron detector (BSE) and the environmental secondary electron detector (ESD) of the ESEM. BSE images had more clearly defined intracellular structures, whereas ESD gave a clearer view of the surface E. gracilis cells fixed with potassium permanganate, Spirogyra sp. stained with Lugol's solution, and Saprolegnia sp. fixed with osmium tetroxide were compared using BSE and ESD to demonstrate that cellular details could be enhanced by the introduction of heavy metals. The effect of cellular water on signal quality was evaluated by comparing hydrated to critical point dried specimens. PMID:8400431

  18. Energy Filtering and Coaxial Detection of the Backscattered Electrons in Scanning Electron Microscope

    Institute of Scientific and Technical Information of China (English)

    JIANG Chang-Zhong; P. Morin; N. Rosenberg

    2000-01-01

    A new detection system in scanning electron microscope, which filters in energy and detects the backscattered electrons close to the microscope axis, is described. This technique ameliorates the dependence of the back. scat tering coefficient on atomic number, and suppresses effectively the relief contrast at the same time. Therefore this new method is very suitable to the composition analysis.

  19. Ultrasonic fatigue testing in the scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Soeker, Marcus; Krupp, Ulrich [University of Applied Sciences, Osnabrueck (Germany). Inst. of Materials Design and Structural Integrity; Galster, Michael [Novelis Inc., Goettingen (Germany); Doenges, Benjamin [Siegen Univ. (Germany)

    2016-02-01

    The continuing trend to increase the performance and durability of machines requires the use of materials, whose structural integrity must be ensured far beyond the classical fatigue limit. In this so-called ''very high cycle fatigue'' regime (VHCF), the materials show a strong scatter in fatigue life, which makes life service assessment difficult. Present studies on austenitic-ferritic duplex steel 1.4462 (X2CrNiMoN22-5-3) have shown that the reason of this scatter in fatigue life can be found in the microstructural length scale mainly due to the barrier effect of grain and phase boundaries. The integration of an ultrasonic fatigue testing system in a high-resolution scanning electron microscope allows observing and evaluating the active microstructural mechanisms of fatigue crack initiation and early crack propagation, such as the formation and propagation of slip bands, during the majority of VHCF life. Additional micro texture measurements by electron backscatter diffraction (EBSD) provide data for the development of a mechanism-oriented numerical short crack simulation. In the context of crack initiation and propagation in the VHCF regime in duplex stainless steel, the focus of the present paper is put on the technical realization of the in-situ ultrasonic fatigue testing in the scanning electron microscope.

  20. Ultrasonic fatigue testing in the scanning electron microscope

    International Nuclear Information System (INIS)

    The continuing trend to increase the performance and durability of machines requires the use of materials, whose structural integrity must be ensured far beyond the classical fatigue limit. In this so-called ''very high cycle fatigue'' regime (VHCF), the materials show a strong scatter in fatigue life, which makes life service assessment difficult. Present studies on austenitic-ferritic duplex steel 1.4462 (X2CrNiMoN22-5-3) have shown that the reason of this scatter in fatigue life can be found in the microstructural length scale mainly due to the barrier effect of grain and phase boundaries. The integration of an ultrasonic fatigue testing system in a high-resolution scanning electron microscope allows observing and evaluating the active microstructural mechanisms of fatigue crack initiation and early crack propagation, such as the formation and propagation of slip bands, during the majority of VHCF life. Additional micro texture measurements by electron backscatter diffraction (EBSD) provide data for the development of a mechanism-oriented numerical short crack simulation. In the context of crack initiation and propagation in the VHCF regime in duplex stainless steel, the focus of the present paper is put on the technical realization of the in-situ ultrasonic fatigue testing in the scanning electron microscope.

  1. Photoemission electron microscopy and scanning electron microscopy of Magnetospirillum magnetotacticum's magnetosome chains.

    Science.gov (United States)

    Keutner, Christoph; von Bohlen, Alex; Berges, Ulf; Espeter, Philipp; Schneider, Claus M; Westphal, Carsten

    2014-10-01

    Magnetotactic bacteria are of great interdisciplinary interest, since a vast field of applications from magnetic recording media to medical nanorobots is conceivable. A key feature for a further understanding is the detailed knowledge about the magnetosome chain within the bacteria. We report on two preparation procedures suitable for UHV experiments in reflective geometry. Further, we present the results of scanning electron microscopy, as well as the first photoemission electron microscopy experiments, both accessing the magnetosomes within intact magnetotactic bacteria and compare these to scanning electron microscopy data from the literature. From the images, we can clearly identify individual magnetosomes within their chains.

  2. Characteristics of different frequency ranges in scanning electron microscope images

    Energy Technology Data Exchange (ETDEWEB)

    Sim, K. S., E-mail: kssim@mmu.edu.my; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S. [Faculty of Engineering and Technology, Multimedia University, 75450 Melaka (Malaysia)

    2015-07-22

    We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement.

  3. Scanning Tunneling Electron Transport into a Kondo Lattice

    Science.gov (United States)

    Yang, Fu-Bin; Wu, Hua

    2016-05-01

    We theoretically present the results for a scanning tunneling transport between a metallic tip and a Kondo lattice. We calculate the density of states (DOS) and the tunneling current and differential conductance (DC) under different conduction-fermion band hybridization and temperature in the Kondo lattice. It is found that the hybridization strength and temperature give asymmetric coherent peaks in the DOS separated by the Fermi energy. The corresponding current and DC intensity depend on the temperature and quantum interference effect among the c-electron and f-electron states in the Kondo lattice. Supported by the National Natural Science Foundation of China under Grant No. 11547203, and the Research Project of Education Department in Sichuan Province of China under Grant No. 15ZB0457

  4. Sample heating system for spin-polarized scanning electron microscopy.

    Science.gov (United States)

    Kohashi, Teruo; Motai, Kumi

    2013-08-01

    A sample-heating system for spin-polarized scanning electron microscopy (spin SEM) has been developed and used for microscopic magnetization analysis at temperatures up to 500°C. In this system, a compact ceramic heater and a preheating operation keep the ultra-high vacuum conditions while the sample is heated during spin SEM measurement. Moreover, the secondary-electron collector, which is arranged close to the sample, was modified so that it is not damaged at high temperatures. The system was used to heat a Co(1000) single-crystal sample from room temperature up to 500°C, and the magnetic-domain structures were observed. Changes of the domain structures were observed around 220 and 400°C, and these changes are considered to be due to phase transitions of this sample.

  5. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    CERN Document Server

    Levin, Barnaby D A; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruna, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180{\\deg} tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of p...

  6. Electrical scanning probe microscopy on active organic electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Pingree, Liam S.C.; Reid, Obadiah G.; Ginger, David S. [Department of Chemistry, University of Washington, Seattle, WA (United States)

    2009-01-05

    Polymer- and small-molecule-based organic electronic devices are being developed for applications including electroluminescent displays, transistors, and solar cells due to the promise of low-cost manufacturing. It has become clear that these materials exhibit nanoscale heterogeneities in their optical and electrical properties that affect device performance, and that this nanoscale structure varies as a function of film processing and device-fabrication conditions. Thus, there is a need for high-resolution measurements that directly correlate both electronic and optical properties with local film structure in organic semiconductor films. In this article, we highlight the use of electrical scanning probe microscopy techniques, such as conductive atomic force microscopy (c-AFM), electrostatic force microscopy (EFM), scanning Kelvin probe microscopy (SKPM), and similar variants to elucidate charge injection/extraction, transport, trapping, and generation/recombination in organic devices. We discuss the use of these tools to probe device structures ranging from light-emitting diodes (LEDs) and thin-film transistors (TFT), to light-emitting electrochemical cells (LECs) and organic photovoltaics. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  7. Direct current scanning field emission microscope integrated with existing scanning electron microscope

    Science.gov (United States)

    Wang, Tong; Reece, Charles E.; Sundelin, Ronald M.

    2002-09-01

    Electron field emission (FE) from broad-area metal surfaces is known to occur at much lower electric field than predicted by Fowler-Nordheim law. Although micron or submicron particles are often observed at such enhanced field emission (EFE) sites, the strength and number of emitting sites and the causes of EFE strongly depend on surface preparation and handling, and the physical mechanism of EFE remains unknown. To systematically investigate the sources of this emission, a dc scanning field emission microscope (SFEM) has been built as an extension to an existing commercial scanning electron microscope (SEM) equipped with an energy-dispersive spectrometer for emitter characterization. In the SFEM chamber of ultrahigh vacuum (approx10-9 Torr), a sample is moved laterally in a raster pattern (2.5 mum step resolution) under a high voltage anode microtip for field emission detection and localization. The sample is then transferred under vacuum by a hermetic retractable linear transporter to the SEM chamber for individual emitter site characterization. Artificial marks on the sample surface serve as references to convert x, y coordinates of emitters in the SFEM chamber to corresponding positions in the SEM chamber with a common accuracy of plus-or-minus100-200 mum in x and y. Samples designed to self-align in sample holders are used in each chamber, allowing them to retain position registration after non-in situ processing to track interesting features. No components are installed inside the SEM except the sample holder, which does not affect the routine operation of the SEM. The apparatus is a system of low cost and maintenance and significant operational flexibility. Field emission sources from planar niobium--the material used in high-field rf superconducting cavities for particle accelerator--have been studied after different surface preparations, and significantly reduced field emitter density has been achieved by refining the preparation process based on scan

  8. Three-Dimensional scanning transmission electron microscopy of biological specimens

    KAUST Repository

    De Jonge, Niels

    2010-01-18

    A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM). The specimen was a metallic replica of the biological structure comprising Pt nanoparticles 2-3 nm in diameter, with a high stability under electron beam radiation. The 3D dataset was processed by an automated deconvolution procedure. The lateral resolution was 1.1 nm, set by pixel size. Particles differing by only 10 nm in vertical position were identified as separate objects with greater than 20% dip in contrast between them. We refer to this value as the axial resolution of the deconvolution or reconstruction, the ability to recognize two objects, which were unresolved in the original dataset. The resolution of the reconstruction is comparable to that achieved by tilt-series transmission electron microscopy. However, the focal-series method does not require mechanical tilting and is therefore much faster. 3D STEM images were also recorded of the Golgi ribbon in conventional thin sections containing 3T3 cells with a comparable axial resolution in the deconvolved dataset. © 2010 Microscopy Society of America.

  9. A scanning electron microscopic investigation of ceramic orthodontic brackets

    International Nuclear Information System (INIS)

    Ceramic brackets were introduced to overcome the esthetic disadvantages of stainless steel brackets. The clinical impression of these brackets is very favorable. However, the sliding mechanics used in the Straightwire (A Company, San Diego, CA, USA) system appear to produce slower tooth movements with ceramic compared to stainless steel brackets. To determine whether this was due to any obvious mechanical problem in the bracket slot, Transcend (Unitek Corporation/3M, Monrovia, CA, USA) ceramic brackets were examined by a scanning electron microscope and compared to stainless steel brackets.Consistently, large surface defects were found in the ceramic bracket slots that were not present in the metal bracket slots. These irregularities could obviously hinder the sliding mechanics of the bracket slot-archwire system and create a greater demand on anchorage. Conversely, the fitting surface of the Transcend ceramic bracket showed extremely smooth surface characteristics, and it would seem advisable for the manufacturers to incorporate this surface within the bracket slot. (author)

  10. Trichomes of Cannabis sativa as viewed with scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Ledbetter, M.C.; Krikorian, A.D.

    1975-06-01

    Direct examination of fresh, unfixed and uncoated specimens from vegetative and floral parts of Cannabis sativa with the scanning electron microscope enables one to obtain a faithful representation of their surface morphology. The presence of two major types of trichomes has been confirmed: a glandular type comprising or terminating in a globoid structure, and a conically-shaped nonglandular type. Moreover, three or possibly four distinct glandular types can be distinguished: sessile globoid, small-stalked and large-stalked globoid, and a peltate type. The nonglandular trichomes can be distinguished by the nature of their surfaces: those with a warty surface, and those which are relatively smooth. The range of size and distribution, and the special features of all these types of trichomes are also provided.

  11. Conditioning of mealybug (Hemiptera: Pseudococcidae by Scanning Electron Microscopy.

    Directory of Open Access Journals (Sweden)

    Melissa Palma-Jiménez

    2015-06-01

    Full Text Available The aim of this work was to determine the methodology for an adequate conditioning for the cleaning of mealybugs specimens and its correct observation. This work was done in the laboratory of the Research Center in Microscopic Structures (CIEMIC of the University of Costa Rica, in 2012. Four types of methodologies were implemented, which evidenced a gradual improvement of the observation of the ultrastructures through the Scanning Electron Microscopy. Every process was described in detail. The best results were showed with 10% xylene (in some cases it was feasible using 95-100% ethanol. It allowed to remove the wax from the body of the insect, avoiding its collapse, and observing the specific ultrastructures of the individual. This approach will reduce the time and cost of future taxonomic research of mealybugs.

  12. Scanning electron microscopy fractography analysis of fractured hollow implants.

    Science.gov (United States)

    Sbordone, Ludovico; Traini, Tonino; Caputi, Sergio; Scarano, Antonio; Bortolaia, Claudia; Piattelli, Adriano

    2010-01-01

    Fracture of the implant is one of the possible complications affecting dental implants; it is a rare event but of great clinical relevance. The aim of the present study was to perform a scanning electron microscopy (SEM) fractography evaluation of 7 International Team for oral Implantology (ITI) hollow implants removed because of fracture. The most common clinical risk factors, such as malocclusion, bruxism, and cantilevers on the prosthesis, were absent. Seven fractured ITI hollow implants were retrieved from 5 patients and were analyzed with the use of SEM. SEM analysis showed typical signs of a cleavage-type fracture. Fractures could be due to an association of multiple factors such as fatigue, inner defects, material electrochemical problems, and tensocorrosion. PMID:20426587

  13. High resolution scanning electron microscopy of cells using dielectrophoresis.

    Directory of Open Access Journals (Sweden)

    Shi-Yang Tang

    Full Text Available Ultrastructural analysis of cells can reveal valuable information about their morphological, physiological, and biochemical characteristics. Scanning electron microscopy (SEM has been widely used to provide high-resolution images from the surface of biological samples. However, samples need to be dehydrated and coated with conductive materials for SEM imaging. Besides, immobilizing non-adherent cells during processing and analysis is challenging and requires complex fixation protocols. In this work, we developed a novel dielectrophoresis based microfluidic platform for interfacing non-adherent cells with high-resolution SEM at low vacuum mode. The system enables rapid immobilization and dehydration of samples without deposition of chemical residues over the cell surface. Moreover, it enables the on-chip chemical stimulation and fixation of immobilized cells with minimum dislodgement. These advantages were demonstrated for comparing the morphological changes of non-budding and budding yeast cells following Lyticase treatment.

  14. Scanning electron microscopy of human cortical bone failure surfaces.

    Science.gov (United States)

    Braidotti, P; Branca, F P; Stagni, L

    1997-02-01

    Undecalcified samples extracted from human femoral shafts are fractured by bending and the fracture surfaces are examined with a scanning electron microscope (SEM). The investigation is performed on both dry and wet (hydrated with a saline solution) specimens. SEM micrographs show patterns in many respects similar to those observed in fractography studies of laminated fiber-reinforced synthetic composites. In particular, dry and wet samples behave like brittle and ductile matrix laminates, respectively. An analysis carried out on the basis of the mechanisms that dominate the fracture process of laminates shows that a reasonable cortical bone model is that of a laminated composite material whose matrix is composed of extracellular noncollagenous calcified proteins, and the reinforcement is constituted by the calcified collagen fiber system. PMID:9001936

  15. [Using of scanning electron microscopy for detection of gunshot residue].

    Science.gov (United States)

    Havel, J; Vajtr, D; Starý, V; Vrána, J; Zelenka, K; Adámek, T

    2006-07-01

    Scanning electron microscope improves the possibility of investigation of surroundings near of gunshot wounds in forensic medicine, it is the next subsequent method for differentiating of area of entrance and exit wound, supplemental method for determination of firing distance, permit of detection (GSR) on the hand of shooter and ensured describing of samples and their stored. Detection of GSR provides many information about composition of bullet and primer. Authors are demonstrating the possibility of detection of GSR on experimental shooting to the krupon (pigs' skin) in different situation (such as in a room and in outside area) and using of different weapon (hand gun CZ No.75 and machine gun No.58). PMID:16948447

  16. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy.

    Science.gov (United States)

    Levin, Barnaby D A; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-06-07

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.

  17. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy.

    Science.gov (United States)

    Levin, Barnaby D A; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data. PMID:27272459

  18. Spinning Carbon Nanotube Nanothread under a Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    Mark Schulz

    2011-08-01

    Full Text Available Nanothread with a diameter as small as one hundred nanometers was manufactured under a scanning electron microscope. Made directly from carbon nanotubes, and inheriting their superior electrical and mechanical properties, nanothread may be the world’s smallest man-made fiber. The smallest thread that can be spun using a bench-top spinning machine is about 5 microns in diameter. Nanothread is a new material building block that can be used at the nanoscale or plied to form yarn for applications at the micro and macro scales. Preliminary electrical and mechanical properties of nanothread were measured. The resistivity of nanothread is less than 10−5 Ω∙m. The strength of nanothread is greater than 0.5 GPa. This strength was obtained from measurements using special glue that cures in an electron microscope. The glue weakened the thread, thus further work is needed to obtain more accurate measurements. Nanothread will have broad applications in enabling electrical components, circuits, sensors, and tiny machines. Yarn can be used for various macroscale applications including lightweight antennas, composites, and cables.

  19. Amyloid Structure and Assembly: Insights from Scanning Transmission Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Goldsbury, C.; Wall, J.; Baxa, U.; Simon, M. N.; Steven, A. C.; Engel, A.; Aebi, U.; Muller, S. A.

    2011-01-01

    Amyloid fibrils are filamentous protein aggregates implicated in several common diseases such as Alzheimer's disease and type II diabetes. Similar structures are also the molecular principle of the infectious spongiform encephalopathies such as Creutzfeldt-Jakob disease in humans, scrapie in sheep, and of the so-called yeast prions, inherited non-chromosomal elements found in yeast and fungi. Scanning transmission electron microscopy (STEM) is often used to delineate the assembly mechanism and structural properties of amyloid aggregates. In this review we consider specifically contributions and limitations of STEM for the investigation of amyloid assembly pathways, fibril polymorphisms and structural models of amyloid fibrils. This type of microscopy provides the only method to directly measure the mass-per-length (MPL) of individual filaments. Made on both in vitro assembled and ex vivo samples, STEM mass measurements have illuminated the hierarchical relationships between amyloid fibrils and revealed that polymorphic fibrils and various globular oligomers can assemble simultaneously from a single polypeptide. The MPLs also impose strong constraints on possible packing schemes, assisting in molecular model building when combined with high-resolution methods like solid-state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR).

  20. Scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, N.; Watanabe, G.; Harada, A.; Suzuki, T.

    1988-11-01

    Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules.

  1. Scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

    International Nuclear Information System (INIS)

    Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules

  2. Monte Carlo simulation of secondary electron images for real sample structures in scanning electron microscopy.

    Science.gov (United States)

    Zhang, P; Wang, H Y; Li, Y G; Mao, S F; Ding, Z J

    2012-01-01

    Monte Carlo simulation methods for the study of electron beam interaction with solids have been mostly concerned with specimens of simple geometry. In this article, we propose a simulation algorithm for treating arbitrary complex structures in a real sample. The method is based on a finite element triangular mesh modeling of sample geometry and a space subdivision for accelerating simulation. Simulation of secondary electron image in scanning electron microscopy has been performed for gold particles on a carbon substrate. Comparison of the simulation result with an experiment image confirms that this method is effective to model complex morphology of a real sample.

  3. Valence electron energy-loss spectroscopy in monochromated scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    With the development of monochromators for (scanning) transmission electron microscopes, valence electron energy-loss spectroscopy (VEELS) is developing into a unique technique to study the band structure and optical properties of nanoscale materials. This article discusses practical aspects of spatially resolved VEELS performed in scanning transmission mode and the alignments necessary to achieve the current optimum performance of ∼0.15 eV energy resolution with an electron probe size of ∼1 nm. In particular, a collection of basic concepts concerning the acquisition process, the optimization of the energy resolution, the spatial resolution and the data processing are provided. A brief study of planar defects in a Y1Ba2Cu3O7-δ high-temperature superconductor illustrates these concepts and shows what kind of information can be accessed by VEELS

  4. Probing Individual Ice Nucleation Events with Environmental Scanning Electron Microscopy

    Science.gov (United States)

    Wang, Bingbing; China, Swarup; Knopf, Daniel; Gilles, Mary; Laskin, Alexander

    2016-04-01

    Heterogeneous ice nucleation is one of the processes of critical relevance to a range of topics in the fundamental and the applied science and technologies. Heterogeneous ice nucleation initiated by particles proceeds where microscopic properties of particle surfaces essentially control nucleation mechanisms. Ice nucleation in the atmosphere on particles governs the formation of ice and mixed phase clouds, which in turn influence the Earth's radiative budget and climate. Heterogeneous ice nucleation is still insufficiently understood and poses significant challenges in predictive understanding of climate change. We present a novel microscopy platform allowing observation of individual ice nucleation events at temperature range of 193-273 K and relative humidity relevant for ice formation in the atmospheric clouds. The approach utilizes a home built novel ice nucleation cell interfaced with Environmental Scanning Electron Microscope (IN-ESEM system). The IN-ESEM system is applied for direct observation of individual ice formation events, determining ice nucleation mechanisms, freezing temperatures, and relative humidity onsets. Reported microanalysis of the ice nucleating particles (INP) include elemental composition detected by the energy dispersed analysis of X-rays (EDX), and advanced speciation of the organic content in particles using scanning transmission x-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). The performance of the IN-ESEM system is validated through a set of experiments with kaolinite particles with known ice nucleation propensity. We demonstrate an application of the IN-ESEM system to identify and characterize individual INP within a complex mixture of ambient particles.

  5. Automated Quantitative Rare Earth Elements Mineralogy by Scanning Electron Microscopy

    Science.gov (United States)

    Sindern, Sven; Meyer, F. Michael

    2016-09-01

    Increasing industrial demand of rare earth elements (REEs) stems from the central role they play for advanced technologies and the accelerating move away from carbon-based fuels. However, REE production is often hampered by the chemical, mineralogical as well as textural complexity of the ores with a need for better understanding of their salient properties. This is not only essential for in-depth genetic interpretations but also for a robust assessment of ore quality and economic viability. The design of energy and cost-efficient processing of REE ores depends heavily on information about REE element deportment that can be made available employing automated quantitative process mineralogy. Quantitative mineralogy assigns numeric values to compositional and textural properties of mineral matter. Scanning electron microscopy (SEM) combined with a suitable software package for acquisition of backscatter electron and X-ray signals, phase assignment and image analysis is one of the most efficient tools for quantitative mineralogy. The four different SEM-based automated quantitative mineralogy systems, i.e. FEI QEMSCAN and MLA, Tescan TIMA and Zeiss Mineralogic Mining, which are commercially available, are briefly characterized. Using examples of quantitative REE mineralogy, this chapter illustrates capabilities and limitations of automated SEM-based systems. Chemical variability of REE minerals and analytical uncertainty can reduce performance of phase assignment. This is shown for the REE phases parisite and synchysite. In another example from a monazite REE deposit, the quantitative mineralogical parameters surface roughness and mineral association derived from image analysis are applied for automated discrimination of apatite formed in a breakdown reaction of monazite and apatite formed by metamorphism prior to monazite breakdown. SEM-based automated mineralogy fulfils all requirements for characterization of complex unconventional REE ores that will become

  6. Investigation of the Remineralization Effect Tnrough Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Damyanova Dobrinka M

    2016-05-01

    Full Text Available Background: Local fluoride varnishes have been widely used as a method of non-operative treatment and for caries preventive interventions for more than three decades. Purpose: Evaluation of the remineralization effect by means of electron microscopy of mineralization varnish - Clinpro ™ White Varnish with TCP (Tri-Calcium phosphate (3M. Materials and Methods: The material used is from 20 temporary intact teeth, extracted due to physiological change with permanent teeth, with a completely preserved structure and anatomy of crowns and fully physiologically resorbed roots. For the purposes of the study a scanning electron microscope JEOL JSM 6390 is used with an attachment for element analysis (EDS INCA of Oxford. Prepared samples are pre-coated with gold (cathode sputtering with apparatus JEOL JFC – 1200 to obtain a better contrast of the SEM image of early carious lesions on the smooth surfaces of the temporary teeth, with predilection for development of caries with a d1 threshold. For this purpose the two processes were monitored occurring continuously on the enamel surfacede- and remineralization. Performed was computer processing of the digital images. Results: There is presence of certain minerals deposited in the embossed enamel prisms after of remineralization. The chemical analysis established the presence of calcium (Ca2 + , around the organic matrix. Demineralised surface has pores present of around 1%, which is visible through the enamel on the surface of the deciduous teeth looking like filled and pores looking like partially covered, filled with newly formed and growing crystals. The crystals, which are hydroxylapatite, fluorapatite or fluorhydroxiapatite gradually connect, growing and forming mineral structure filling the microscopi defects and the pores from the demineralisation in the surface enamel prismless layer

  7. Scanning electron microscopy of the neuropathology of murine cerebral malaria

    Directory of Open Access Journals (Sweden)

    Brenneis Christian

    2006-11-01

    Full Text Available Abstract Background The mechanisms leading to death and functional impairments due to cerebral malaria (CM are yet not fully understood. Most of the knowledge about the pathomechanisms of CM originates from studies in animal models. Though extensive histopathological studies of the murine brain during CM are existing, alterations have not been visualized by scanning electron microscopy (SEM so far. The present study investigates the neuropathological features of murine CM by applying SEM. Methods C57BL/6J mice were infected with Plasmodium berghei ANKA blood stages. When typical symptoms of CM developed perfused brains were processed for SEM or light microscopy, respectively. Results Ultrastructural hallmarks were disruption of vessel walls, parenchymal haemorrhage, leukocyte sequestration to the endothelium, and diapedesis of macrophages and lymphocytes into the Virchow-Robin space. Villous appearance of observed lymphocytes were indicative of activated state. Cerebral oedema was evidenced by enlargement of perivascular spaces. Conclusion The results of the present study corroborate the current understanding of CM pathophysiology, further support the prominent role of the local immune system in the neuropathology of CM and might expose new perspectives for further interventional studies.

  8. Plinia edulis - leaf architecture and scanning electron micrographs

    Directory of Open Access Journals (Sweden)

    Ana M. Donato

    2013-06-01

    Full Text Available Many species of Myrtaceae, including Plinia edulis (Vell. Sobral (cambucá, have pharmacological properties and are used as hypoglycemiants and therapeutic agents against stomach problems and throat infections. Samples were collected from Tijuca Forest in Rio de Janeiro, and the morpho-anatomical data were compared with other specimens obtained from Trindade, Paraty, found in the literature. Variations in leaf anatomy were observed, and the possible causes for these effects are discussed. The plant material collected from Tijuca Forest was analyzed using scanning electron and optical microscopy. Histochemical tests were applied to identify starch, lipids, phenolic compounds and lignin. The epidermal cells exhibit straight or slightly sinuous anticlinal walls covered by a smooth cuticle with granules of wax. Simple trichomes are restricted to the midrib region, and paracytic stomata are only observed on the abaxial leaf surface. The mesophyll is dorsiventral, with conspicuous intercellular spaces in the spongy parenchyma. Intercalated columns of crystalliferous cells and subepidermal secretory cavities are observed in the single layer of palisade parenchyma. The samples obtained from Trindade, Paraty, show larger leaves, anomocytic stomata and trichomes scattered throughout the leaf surface. This plasticity might reflect leaf adaptations to environmental factors or different stages of leaf development.

  9. Non-thermal plasma mills bacteria: Scanning electron microscopy observations

    Energy Technology Data Exchange (ETDEWEB)

    Lunov, O., E-mail: lunov@fzu.cz; Churpita, O.; Zablotskii, V.; Jäger, A.; Dejneka, A. [Institute of Physics AS CR, Prague 18221 (Czech Republic); Deyneka, I. G.; Meshkovskii, I. K. [St. Petersburg State University of Information Technologies, Mechanics and Optics, St. Petersburg 197101 (Russian Federation); Syková, E. [Institute of Experimental Medicine AS CR, Prague 14220 (Czech Republic); Kubinová, Š. [Institute of Physics AS CR, Prague 18221 (Czech Republic); Institute of Experimental Medicine AS CR, Prague 14220 (Czech Republic)

    2015-02-02

    Non-thermal plasmas hold great promise for a variety of biomedical applications. To ensure safe clinical application of plasma, a rigorous analysis of plasma-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal plasma remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric plasma on Gram-positive and Gram-negative bacteria. Using scanning electron microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium plasma. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin–stained rat skin sections from plasma–treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal plasma irradiation. Our findings disclose how helium plasma destroys bacteria and demonstrates the safe use of plasma treatment for MSCs and skin cells, highlighting the favorability of plasma applications for chronic wound therapy.

  10. Scanning electron microscopy of xiphinema, longidorus, and californidorus stylet morphology.

    Science.gov (United States)

    Cho, M R; Robbins, R T

    1990-04-01

    Stylet ultrastructure of five Xiphinema, four Longidorus, and three Californidorus species was compared by scanning electron microscopy. Morphological differences were seen in the odontophores and odontostyle bases between the genera and some of the species. All Xiphinema studied had well-developed odontophore flanges; the Longidorus species lacked flanges, except for weakly developed ones in L. diadecturus; and none of the Californidorus had flanges. Three sinuses were present in the odontophores of all species. The sinuses varied in length depending upon species. In Xiphinema and Californidorus the odontostyle bases had distinct overlapping collars, but in Longidorus the collars were absent except for L. diadecturus. The odontostyle-odontophore junction from a lateral view appeared as a slanted transverse line in all the species, but in a dorsal view of Xiphinema and Californidorus it was V-shaped. Dorsal longitudinal seams of the odontostyle and odontophore were observed in all the species. The dorsally located odontostyle aperture was ca. 1 mum from the anterior end in all species, except in one Longidorus sp. it was ca. 4 mum from the end.

  11. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Junaid ASLAM

    2014-06-01

    Full Text Available Catharanthus roseus (L. G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in vitro germinated seeds on which somatic embryos, differentiated in numbers, particularly on 2,4-D (1.0 mg/L Murashige and Skoog (MS was medium. To understand more about the regeneration method and in vitro formed embryos SEM was performed. The SEM study revealed normal somatic embryo origin and development from globular to heart-, torpedo- and then into cotyledonary-stage of embryos. At early stage, the embryos were clustered together in a callus mass and could not easily be detached from the parental tissue. The embryos were often long cylindrical structure with or without typical notch at the tip. Secondary embryos were also formed on primary embryo structure. The advanced cotyledonary embryos showed prominent roots and shoot axis, which germinated into plantlets. The morphology, structure and other details of somatic embryos at various stages were presented.

  12. Migratory behaviour of tumour cells: a scanning electron microscopy study

    Directory of Open Access Journals (Sweden)

    Giuseppina Bozzuto

    2015-06-01

    Full Text Available BACKGROUND: Tumour cells utilize different migration strategies to invade surrounding tissues and elude anticancer treatments. It is therefore important to understand the mechanisms underlying migration process, in order to aid the development of therapies aimed at blocking the dissemination of cancer cells. AIMS: In this study tumour cell lines of different histological origin were analysed by combining 2D and 3D in vitro assays, biochemical tests and high resolution imaging by scanning electron microscopy (SEM in order to look insight strategies adopted by tumour cells to invade extracellular matrix. RESULTS: Quantitative (computer-assisted colour camera equipped-light microscopy and qualitative analysis (SEM indicated that the most aggressive tumour cells adopt an "individual" behaviour. The analysis of intracellular signalling demonstrated that the highest invasive potential was associated with the activation of AKT, ERK, FAK and ERM proteins. The "individual" behaviour was positively related to the expression of VLA-2 and inversely related with the E-cadherin expression. CONCLUSIONS: The combination of 2D and 3D in vitro assays, biochemical tests and ultrastructural investigations proved to be a suitable test for the investigation of tumour cell migration and invasion. The high resolution imaging by SEM highlighted the interrelationships between cells in different migratory behaviours of tumour cells.

  13. Non-thermal plasma mills bacteria: Scanning electron microscopy observations

    Science.gov (United States)

    Lunov, O.; Churpita, O.; Zablotskii, V.; Deyneka, I. G.; Meshkovskii, I. K.; Jäger, A.; Syková, E.; Kubinová, Š.; Dejneka, A.

    2015-02-01

    Non-thermal plasmas hold great promise for a variety of biomedical applications. To ensure safe clinical application of plasma, a rigorous analysis of plasma-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal plasma remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric plasma on Gram-positive and Gram-negative bacteria. Using scanning electron microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium plasma. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin-stained rat skin sections from plasma-treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal plasma irradiation. Our findings disclose how helium plasma destroys bacteria and demonstrates the safe use of plasma treatment for MSCs and skin cells, highlighting the favorability of plasma applications for chronic wound therapy.

  14. Non-thermal plasma mills bacteria: Scanning electron microscopy observations

    International Nuclear Information System (INIS)

    Non-thermal plasmas hold great promise for a variety of biomedical applications. To ensure safe clinical application of plasma, a rigorous analysis of plasma-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal plasma remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric plasma on Gram-positive and Gram-negative bacteria. Using scanning electron microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium plasma. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin–stained rat skin sections from plasma–treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal plasma irradiation. Our findings disclose how helium plasma destroys bacteria and demonstrates the safe use of plasma treatment for MSCs and skin cells, highlighting the favorability of plasma applications for chronic wound therapy

  15. Electron beam heating effects during environmental scanning electron microscopy imaging of water condensation on superhydrophobic surfaces

    Science.gov (United States)

    Rykaczewski, K.; Scott, J. H. J.; Fedorov, A. G.

    2011-02-01

    Superhydrophobic surfaces (SHSs) show promise as promoters of dropwise condensation. Droplets with diameters below ˜10 μm account for the majority of the heat transferred during dropwise condensation but their growth dynamics on SHS have not been systematically studied. Due to the complex topography of the surface environmental scanning electron microscopy is the preferred method for observing the growth dynamics of droplets in this size regime. By studying electron beam heating effects on condensed water droplets we establish a magnification limit below which the heating effects are negligible and use this insight to study the mechanism of individual drop growth.

  16. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam.

    Science.gov (United States)

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A; Vick, Andrew J

    2016-01-01

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices. PMID:27586090

  17. Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam

    Science.gov (United States)

    Hirohata, Atsufumi; Yamamoto, Yasuaki; Murphy, Benedict A.; Vick, Andrew J.

    2016-09-01

    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing for an increase in the number of transistors in a processor. However, uniform electron transport has not yet been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes that can potentially introduce additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices.

  18. Ultra low-K shrinkage behavior when under electron beam in a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Lorut, F.; Imbert, G. [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Roggero, A. [Centre National d' Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)

    2013-08-28

    In this paper, we investigate the tendency of porous low-K dielectrics (also named Ultra Low-K, ULK) behavior to shrink when exposed to the electron beam of a scanning electron microscope. Various experimental electron beam conditions have been used for irradiating ULK thin films, and the resulting shrinkage has been measured through use of an atomic force microscope tool. We report the shrinkage to be a fast, cumulative, and dose dependent effect. Correlation of the shrinkage with incident electron beam energy loss has also been evidenced. The chemical modification of the ULK films within the interaction volume has been demonstrated, with a densification of the layer and a loss of carbon and hydrogen elements being observed.

  19. The conductivity of dielectrics during irradiation by scanning high power electron beam

    International Nuclear Information System (INIS)

    The conductivity of dielectrics under electron beam irradiation is fundamental question of physics for interaction of electron beams with condensed mater. The CW electron accelerator Rhodotron with scanning electron beams was used in the experiments. The electron beam has next main parameters: kinetic energy is 5 MeV, maximum power is 80 kW, and the scanning repetition is 100 Hz. The results of measurements are discussed

  20. Scanning Transmission X-Ray, Laser Scanning, and Transmission Electron Microscopy Mapping of the Exopolymeric Matrix of Microbial Biofilms

    OpenAIRE

    Lawrence, J. R.; Swerhone, G. D. W.; Leppard, G. G.; T. Araki; Zhang, X.; West, M. M.; A. P. Hitchcock

    2003-01-01

    Confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and soft X-ray scanning transmission X-ray microscopy (STXM) were used to map the distribution of macromolecular subcomponents (e.g., polysaccharides, proteins, lipids, and nucleic acids) of biofilm cells and matrix. The biofilms were developed from river water supplemented with methanol, and although they comprised a complex microbial community, the biofilms were dominated by heterotrophic bacteria. TEM provid...

  1. Scanning electron microscopic study of capillary change in bleomycin-induced pulmonary fibrosis.

    OpenAIRE

    Kwon, K. Y.; Park, K K; Chang, E. S.

    1991-01-01

    The architectural changes which occur in the capillaries are difficult to illustrate without a three-dimensional tool, such as scanning electron microscopy. Therefore, a scanning electron microscopic study was occasionally undertaken to show the capillary changes of lung fibrosis. Fibrosis was induced in twenty rats by an intratracheal injection of bleomycin. After 30 days the rats were sacrificed, and light microscopy and scanning electron microscopy were performed. The vascular trees of bot...

  2. Reproducible strain measurement in electronic devices by applying integer multiple to scanning grating in scanning moiré fringe imaging

    Directory of Open Access Journals (Sweden)

    Suhyun Kim

    2014-10-01

    Full Text Available Scanning moiré fringe (SMF imaging by high-angle annular dark field scanning transmission electron microscopy was used to measure the strain field in the channel of a transistor with a CoSi2 source and drain. Nanometer-scale SMFs were formed with a scanning grating size of ds at integer multiples of the Si crystal lattice spacing dl (ds ∼ ndl, n = 2, 3, 4, 5. The moiré fringe formula was modified to establish a method for quantifying strain measurement. We showed that strain fields in a transistor measured by SMF images were reproducible with an accuracy of 0.02%.

  3. [High resolution scanning electron microscopy of isolated outer hair cells].

    Science.gov (United States)

    Koitschev, A; Müller, H

    1996-11-01

    Isolated hair cell preparations have gained wide acceptance as a model for studying physiological and molecular properties of the sensory cells involved in the hearing process. Ultrastructural details, such as stereocilia links, lateral membrane substructure or synaptic links are of crucial importance for normal sensory transduction. For this reason, we developed a high-resolution scanning electron microscopy (SEM) procedure to study the surface of isolated hair cells. Cells were mechanically and/or enzymatically separated, isolated and immobilized on cover slips by alcian blue and fixed by 2% glutardialdehyde or 1% OsO4. After dehydration, preparations were critical point-dried and sputter-coated with gold-palladium (2-4 nm). Up to 5 nm resolution was achieved. Optimal fixation kept the cells in their typical cylindrical forms. Preservation of the stereocilia and the apical plates of the outer hair cells depended strongly on the fixation process. Tip- and side-links were observed only sporadically because of the aggressive preparation procedure. The lateral plasma membranes of the cell bodies showed regular granular structures of 5-7 nm diameter at maximal magnification. The granular structure of the cell membrane seemed to correspond to putative transmembrane proteins believed to generate membrane-based motility. The remnants of the nerve endings and/or supporting cells usually covered the cell base. The preservation of the cells was better when enzymatic isolation was omitted. The technique used allowed for high resolution ultrastructural examination of isolated hair cells and, when combined with immunological labeling, may permit the identification of proteins at a molecular level. PMID:9064297

  4. Sparse sampling and reconstruction for electron and scanning probe microscope imaging

    Science.gov (United States)

    Anderson, Hyrum; Helms, Jovana; Wheeler, Jason W.; Larson, Kurt W.; Rohrer, Brandon R.

    2015-07-28

    Systems and methods for conducting electron or scanning probe microscopy are provided herein. In a general embodiment, the systems and methods for conducting electron or scanning probe microscopy with an undersampled data set include: driving an electron beam or probe to scan across a sample and visit a subset of pixel locations of the sample that are randomly or pseudo-randomly designated; determining actual pixel locations on the sample that are visited by the electron beam or probe; and processing data collected by detectors from the visits of the electron beam or probe at the actual pixel locations and recovering a reconstructed image of the sample.

  5. Electronic Single Molecule Measurements with the Scanning Tunneling Microscope

    Science.gov (United States)

    Im, Jong One

    Richard Feynman said "There's plenty of room at the bottom". This inspired the techniques to improve the single molecule measurements. Since the first single molecule study was in 1961, it has been developed in various field and evolved into powerful tools to understand chemical and biological property of molecules. This thesis demonstrates electronic single molecule measurement with Scanning Tunneling Microscopy (STM) and two of applications of STM; Break Junction (BJ) and Recognition Tunneling (RT). First, the two series of carotenoid molecules with four different substituents were investigated to show how substituents relate to the conductance and molecular structure. The measured conductance by STM-BJ shows that Nitrogen induces molecular twist of phenyl distal substituents and conductivity increasing rather than Carbon. Also, the conductivity is adjustable by replacing the sort of residues at phenyl substituents. Next, amino acids and peptides were identified through STM-RT. The distribution of the intuitive features (such as amplitude or width) are mostly overlapped and gives only a little bit higher separation probability than random separation. By generating some features in frequency and cepstrum domain, the classification accuracy was dramatically increased. Because of large data size and many features, supporting vector machine (machine learning algorithm for big data) was used to identify the analyte from a data pool of all analytes RT data. The STM-RT opens a possibility of molecular sequencing in single molecule level. Similarly, carbohydrates were studied by STM-RT. Carbohydrates are difficult to read the sequence, due to their huge number of possible isomeric configurations. This study shows that STM-RT can identify not only isomers of mono-saccharides and disaccharides, but also various mono-saccharides from a data pool of eleven analytes. In addition, the binding affinity between recognition molecule and analyte was investigated by comparing with

  6. Remote control scanning electron microscope with Web operation

    International Nuclear Information System (INIS)

    Full text: Recently, SEM (Scanning Electron Microscope) and the other observation instruments are coming to use a LAN (Local Area Network) to save the image in the database. We developed a remote control system in which SEM image and Control interface is indicated on the WEB Browser. In this system, SEM can be controlled by an external (client) PC installed in a general WEB Browser (Internet Explorer). Accordingly, operation interface can be indicated on the WEB browser. A JSM-6700F is connected to a LAN, and so a client PC can control the microscope. The JSM-6700F has two lines to the LAN for image transfer and communication with the SEM control. In order to transfer the image, the image size squeezes from 1280 x 1024-pixels (SEM image size) to 640x480-pixels for quick transfer. The image signal (640 x 480-pixels) is connected to the video server only, and then the image transfers to the client PC via LAN. The SEM control communicates with client PC for external command. On the other hand, the SEM control interface and the image are indicated on WEB Browser (Internet explorer). The SEM control interface is composed of the SEM image area and the SEM control part. The SEM image indicates the 640x480-pixels live image. This live image is being used as a high resolution live image transfer in the image transfer technology which a network is used for at present. If it is LAN beyond 10 base, this indication of an image can be transferred fully. When it is connected in the small line of the capacity, the refresh speed of the image becomes slow because of image data doesn't finish transferring it. In such a case, image size can be changed smaller by the LAN conditions. When a high quality image is necessary, the image of 1280 x 1024-pixels is saved on a SEM (server) side by choosing the image save button. At the same time, the file kept in SEM (server) is transferred to the client PC automatically, so that we can display a high quality image on the client PC side. The

  7. The propagation of high power CW scanning electron beam in air

    International Nuclear Information System (INIS)

    The question of propagation of high power electron beam in air presents the scientific and applied interests. The high power (80 kW) CW electron accelerator 'Rhodotron' with kinetic energy of electrons 5 and 10 MeV was used in the experiments. The experimental results for propagation of scanning electron beams in air are presented and discussed

  8. Contribution of scanning Auger microscopy to electron beam damage study

    International Nuclear Information System (INIS)

    Electron bombardment can produce surface modifications of the analysed sample. The electron beam effects on solid surfaces which have been discussed in the published literature can be classified into the following four categories: (1) heating and its consequent effects, (2) charge accumulation in insulators and its consequent effects, (3) electron stimulated adsorption (ESA), and (4) electron stimulated desorption and/or decomposition (ESD). In order to understand the physico-chemical processes which take place under electron irradiation in an Al-O system, we have carried out experiments in which, effects, such as heating, charging and gas contamination, were absent. Our results point out the role of an enhanced surface diffusion of oxygen during electron bombardment of an Al (111) sample. The importance of this phenomenon and the contribution of near-elastic scattering of the primary electrons (5 keV) to the increase of the oxidation degree observed on Al (111) are discussed, compared to the generally studied effects

  9. Electronically Steerable Antennas with Panoramic Scan Field of View Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Electronically steerable antennas are key to effective radio transmission at millimeter-wave frequencies. To enable communication with rovers, robots, EVA...

  10. Reproducible strain measurement in electronic devices by applying integer multiple to scanning grating in scanning moiré fringe imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suhyun, E-mail: u98kim@surface.phys.titech.ac.jp; Jung, Younheum; Kim, Joong Jung; Lee, Sunyoung; Lee, Haebum [Memory Analysis Science and Engineering Group, Samsung Electronics, San #16 Hwasung-city, Gyeonggi-Do 445-701 (Korea, Republic of); Kondo, Yukihito [EM Business Unit, JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan)

    2014-10-15

    Scanning moiré fringe (SMF) imaging by high-angle annular dark field scanning transmission electron microscopy was used to measure the strain field in the channel of a transistor with a CoSi{sub 2} source and drain. Nanometer-scale SMFs were formed with a scanning grating size of d{sub s} at integer multiples of the Si crystal lattice spacing d{sub l} (d{sub s} ∼ nd{sub l}, n = 2, 3, 4, 5). The moiré fringe formula was modified to establish a method for quantifying strain measurement. We showed that strain fields in a transistor measured by SMF images were reproducible with an accuracy of 0.02%.

  11. Atom location using scanning transmission electron microscopy based on electron energy loss spectroscopy

    International Nuclear Information System (INIS)

    Full text: The technique of atom location by channelling enhanced microanalysis (ALCHEMI) using cross section data, measured as a function of electron beam orientation, has been widely implemented by many researchers. The accurate application of ALCHEMI, usually based on energy dispersive x-ray analysis (EDX), requires knowledge, from first principles, of the relative delocalization of the inner-shell ionization interaction (see for example Oxley and Allen, 1998; Oxley et al., 1999). Scanning transmission electron microscopy (STEM) based on electron energy loss spectroscopy (EELS) also provides information about the location of atoms of different types within the crystal lattice. Unlike high angle annular dark field (HAADF), EELS provides a unique signal for each atom type. In conjunction with highly focused probes, allowing near atomic resolution, this makes possible, in principle, the application of ALCHEMI like techniques to STEM images to determine the distribution of impurities within the unit cell. The accurate interpretation of STEM results requires that both the inner-shell ionization interaction and resulting ionization cross section or image be correctly modelled. We present model calculations demonstrating the in principle application of ALCHEMI type techniques to STEM images pertinent to EELS. The inner-shell ionisation interaction is modelled using Hartree-Fock wave functions to describe the atomic bound states and Hartree-Slater wave functions to describe the continuum states. The wave function within the crystal is calculated using boundary conditions appropriate for a highly focussed probe (Rossouw and Allen, 2001) and STEM images or ionisation cross sections are simulated using an inelastic cross section formulation that correctly accounts for the contribution from both dynamical electrons and those dechannelled by absorptive scattering processes such as thermal diffuse scattering (TDS). Copyright (2002) Australian Society for Electron Microscopy

  12. Local thermal conductivity of polycrystalline AlN ceramics measured by scanning thermal microscopy and complementary scanning electron microscopy techniques

    Institute of Scientific and Technical Information of China (English)

    Zhang Yue-Fei; Wang Li; R. Heiderhoff; A. K. Geinzer; Wei Bin; Ji Yuan; Han Xiao-Dong; L. J. Balk; Zhang Ze

    2012-01-01

    The local thermal conductivity of polycrystalline aluminum nitride (AlN) ceramics is measured and imaged by using a scanning thermal microscope (SThM) and complementary scanning electron microscope (SEM) based techniques at room temperature.The quantitative thermal conductivity for the AlN sample is gained by using a SThM with a spatial resolution of sub-micrometer scale through using the 3w method.A thermal conductivity of 308 W/m·K withingrains corresponding to that of high-purity single crystal AlN is obtained.The slight differences in thermal conduction between the adjacent grains are found to result from crystallographic misorientations,as demonstrated in the electron backscattered diffraction.A much lower thermal conductivity at the grain boundary is due to impurities and defects enriched in these sites,as indicated by energy dispersive X-ray spectroscopy.

  13. Correcting for 3D distortion when using backscattered electron detectors in a scanning electron microscope.

    Science.gov (United States)

    Proctor, Jacob M

    2009-01-01

    A variable pressure scanning electron microscope (VPSEM) can produce a topographic surface relief of a physical object under examination, in addition to its two-dimensional (2D) image. This topographic surface relief is especially helpful when dealing with porous rock because it may elucidate the pore-space structure as well as grain shape and size. Whether the image accurately reproduces the physical object depends on the management of the hardware, acquisition, and postprocessing. Two problems become apparent during testing: (a) a topographic surface relief of a precision ball bearing is distorted and does not correspond to the physical dimensions of the actual sphere and (b) an image of a topographic surface relief of a Berea sandstone is geometrically tilted and topographically distorted even after standard corrections are applied. The procedure presented here is to ensure the veracity of the image, and includes: (a) adjusting the brightness and contrast levels originally provided by the manufacturer and (b) tuning the amplifiers of the backscatter detector plates to be equal to each other, and producing zero voltage when VPSEM is idle. This procedure is tested and verified on the said two physical samples. SCANNING 31: 59-64, 2009. (c) 2009 Wiley Periodicals, Inc.

  14. Surface sensitivity effects with local probe scanning Auger–scanning electron microscopy

    NARCIS (Netherlands)

    Agterveld, D.T.L. van; Palasantzas, G.; Hosson, J.Th.M. De

    1999-01-01

    This letter concentrates on a quantitative description of surface roughness effects on Auger peak-line profiles for pure and alloyed specimens. The nanometer lateral electron probe size of the order of 10 nm yielded peak-line profiles that capture surface topology variations down to nanometer-length

  15. Method and apparatus for a high-resolution three dimensional confocal scanning transmission electron microscope

    Science.gov (United States)

    de Jonge, Niels [Oak Ridge, TN

    2010-08-17

    A confocal scanning transmission electron microscope which includes an electron illumination device providing an incident electron beam propagating in a direction defining a propagation axis, and a precision specimen scanning stage positioned along the propagation axis and movable in at least one direction transverse to the propagation axis. The precision specimen scanning stage is configured for positioning a specimen relative to the incident electron beam. A projector lens receives a transmitted electron beam transmitted through at least part of the specimen and focuses this transmitted beam onto an image plane, where the transmitted beam results from the specimen being illuminated by the incident electron beam. A detection system is placed approximately in the image plane.

  16. Ultrastructure of Proechinophthirus zumpti (Anoplura, Echinophthiriidae by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Dolores del Carmen Castro

    2002-09-01

    Full Text Available The ultrastructure of Proechinophthirus zumpti Werneck, 1955, mainly the external chorionic features of the egg, is described through electronic microscopy techniques. This species was first cited in Argentina, infesting Arctocephalus australis (Zimmermann, 1873. The morphological adaptations of adults and nymphs are described in both species of Proechinophthirus parasitic on Otariidae: P. fluctus (Ferris, 1916 and P. zumpti.

  17. A Low Cost, Electronically Scanned Array (ESA) Antenna Technology for Aviation Hazard Detection and Avoidance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will investigate the feasibility of utilizing ThinKom's low cost electronically scanned array (ESA) antenna concepts to enable affordable...

  18. Manufacture and scanning electron microscopic observation of human dermis collagen membrane

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    @@ Introduction Collagen is a kind of biomacromolecule and can be used as cover material for burn wounds. In this article,we report the scanning electron microscopic observation of human dermis collagen membrane prepared by three methods.

  19. Surface textures of quartz grains from Goa coast - An application of the scanning electron microscope

    Digital Repository Service at National Institute of Oceanography (India)

    Ambre, N.V.; Gujar, A.R.; Mislankar, P.G.

    The scanning electron microscopy of quartz grains along the Goa beaches reveals 10 microfeatures. Three types of process response environments viz. Beach (Littoral), subaqueous and low to high-energy chemical environments appears to be active...

  20. Quantitative detection of gold nanoparticles on individual, unstained cancer cells by scanning electron microscopy

    NARCIS (Netherlands)

    L. Hartsuiker; P. van Es; W. Petersen; T.G. van Leeuwen; L.W.M.M. Terstappen; C. Otto

    2011-01-01

    Gold nanoparticles are rapidly emerging for use in biomedical applications. Characterization of the interaction and delivery of nanoparticles to cells through microscopy is important. Scanning electron microscopes have the intrinsic resolution to visualize gold nanoparticles on cells. A novel sample

  1. Electronic linearization of piezoelectric actuators and noise budget in scanning probe microscopy

    Science.gov (United States)

    Aloisi, G.; Santucci, A.; Carlà, M.; Dolci, D.; Lanzi, L.

    2006-07-01

    The maximum resolution achievable with a scanning probe microscope is limited by the probe size, by the mechanism of interaction with the sample, as is widely known, and by the electronic noise in the instrument. The evaluation of this noise for the three motion axes of a linearized high resolution scanning electrochemical microscope has been carried through and the intrinsic maximum resolution is discussed.

  2. Correlative Analysis of Immunoreactivity in Confocal Laser-Scanning Microscopy and Scanning Electron Microscopy with Focused Ion Beam Milling

    Directory of Open Access Journals (Sweden)

    Takahiro eSonomura

    2013-02-01

    Full Text Available Three-dimensional reconstruction of ultrastructure of rat brain with minimal effort has recently been realized by scanning electron microscopy combined with focused ion beam milling (FIB-SEM. Because application of immunohistochemical staining to electron microscopy has a great advantage in that molecules of interest are specifically localized in ultrastructures, we here tried to apply immunocytochemistry to FIB-SEM and correlate immunoreactivity in confocal laser-scanning microcopy (CF-LSM with that in FIB-SEM. The dendrites of medium-sized spiny neurons in rat neostriatum were visualized with a recombinant viral vector, which labeled the infected neurons with membrane-targeted GFP in a Golgi stain-like fashion, and thalamostriatal afferent terminals were immunolabeled with Cy5 fluorescence for vesicular glutamate transporter 2 (VGluT2. After detecting the sites of terminals apposed to the dendrites in CF-LSM, GFP and VGluT2 immunoreactivities were further developed for electron microscopy by the immunogold/silver enhancement and immunoperoxidase/diaminobenzidine (DAB methods, respectively. In the contrast-inverted FIB-SEM images, silver precipitation and DAB deposits were observed as fine dark grains and diffuse dense profiles, respectively, indicating that these immunoreactivities were easily recognizable as in the images of transmission electron microscopy. In the sites of interest, some appositions were revealed to display synaptic specialization of asymmetric type. The present method is thus useful in the three-dimensional analysis of immunocytochemically differentiated synaptic connection in the central neural circuit.

  3. Design of Pixellated CMOS Photon Detector for Secondary Electron Detection in the Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    Joon Huang Chuah

    2011-01-01

    Full Text Available This paper presents a novel method of detecting secondary electrons generated in the scanning electron microscope (SEM. The method suggests that the photomultiplier tube (PMT, traditionally used in the Everhart-Thornley (ET detector, is to be replaced with a configurable multipixel solid-state photon detector offering the advantages of smaller dimension, lower supply voltage and power requirements, and potentially cheaper product cost. The design of the proposed detector has been implemented using a standard 0.35 μm CMOS technology with optical enhancement. This microchip comprises main circuit constituents of an array of photodiodes connecting to respective noise-optimised transimpedance amplifiers (TIAs, a selector-combiner (SC circuit, and a postamplifier (PA. The design possesses the capability of detecting photons with low input optical power in the range of 1 nW with 100 μm × 100 μm sized photodiodes and achieves a total amplification of 180 dBΩ at the output.

  4. Interstitial cells of Cajal and Auerbach's plexus. A scanning electron microscopical study of guinea-pig small intestine

    DEFF Research Database (Denmark)

    Jessen, Harry; Thuneberg, Lars

    1991-01-01

    Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy......Anatomy, interstitial cells of Cajal, myenteric plexus, small intestine, guinea-pig, scanning electron microscopy...

  5. Epidermal growth factor receptor subunit locations determined in hydrated cells with environmental scanning electron microscopy

    OpenAIRE

    Peckys, Diana B.; Jean-Pierre Baudoin; Magdalena Eder; Ulf Werner; Niels de Jonge

    2013-01-01

    Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the l...

  6. 3D Imaging of mammalian cells with ion-abrasion scanning electron microscopy

    OpenAIRE

    Heymann, Jurgen A. W.; Shi, Dan; Kim, Sang; Bliss, Donald; Milne, Jacqueline L. S.; Subramaniam, Sriram

    2008-01-01

    Understanding the hierarchical organization of molecules and organelles within the interior of large eukaryotic cells is a challenge of fundamental interest in cell biology. We are using ion-abrasion scanning electron microscopy (IA-SEM) to visualize this hierarchical organization in an approach that combines focused ion-beam milling with scanning electron microscopy. Here, we extend our previous studies on imaging yeast cells to image subcellular architecture in human melanoma cells and mela...

  7. Large area fabrication of plasmonic nanoparticle grating structure by conventional scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.; Srivastava, A. K. [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advance Technology, Indore-452013 (India); Mukharjee, C. [Mechanical & Optical Support Section, Raja Ramanna Centre for Advance Technology, Indore 452013 (India)

    2015-06-24

    Plasmonic nanoparticle grating (PNG) structure of different periods has been fabricated by electron beam lithography using silver halide based transmission electron microscope film as a substrate. Conventional scanning electron microscope is used as a fabrication tool for electron beam lithography. Optical microscope and energy dispersive spectroscopy (EDS) have been used for its morphological and elemental characterization. Optical characterization is performed by UV-Vis absorption spectroscopic technique.

  8. Photoemission electron microscopy and scanning electron microscopy of Magnetospirillum magnetotacticum’s magnetosome chains

    Energy Technology Data Exchange (ETDEWEB)

    Keutner, Christoph [Technische Univ. Dortmund, Dortmung (Germany); von Bohlen, Alex [Leibniz-Institut fur Analytische Wissenschaften, Dortmund (Germany); Berges, Ulf [Technische Univ. Dortmund, Dortmung (Germany); Espeter, Philipp [Technische Univ. Dortmund, Dortmung (Germany); Schneider, Claus M. [Peter Grunberg Institut, Julich (Germany); Westphal, Carsten [Technische Univ. Dortmund, Dortmung (Germany)

    2014-10-07

    Magnetotactic bacteria are of great interdisciplinary interest, since a vast field of applications from magnetic recording media to medical nanorobots is conceivable. A key feature for a further understanding is the detailed knowledge about the magnetosome chain within the bacteria. We report on two preparation procedures suitable for UHV experiments in reflective geometry. Further, we present the results of scanning electron microscopy, as well as the first photoemission electron microscopy experiments, both accessing the magnetosomes within intact magnetotactic bacteria and compare these to scanning electron microscopy data from the literature. From the images, we can clearly identify individual magnetosomes within their chains.

  9. Modeling a Miniaturized Scanning Electron Microscope Focusing Column - Lessons Learned in Electron Optics Simulation

    Science.gov (United States)

    Loyd, Jody; Gregory, Don; Gaskin, Jessica

    2016-01-01

    This presentation discusses work done to assess the design of a focusing column in a miniaturized Scanning Electron Microscope (SEM) developed at the NASA Marshall Space Flight Center (MSFC) for use in-situ on the Moon-in particular for mineralogical analysis. The MSFC beam column design uses purely electrostatic fields for focusing, because of the severe constraints on mass and electrical power consumption imposed by the goals of lunar exploration and of spaceflight in general. The resolution of an SEM ultimately depends on the size of the focused spot of the scanning beam probe, for which the stated goal here is a diameter of 10 nanometers. Optical aberrations are the main challenge to this performance goal, because they blur the ideal geometrical optical image of the electron source, effectively widening the ideal spot size of the beam probe. In the present work the optical aberrations of the mini SEM focusing column were assessed using direct tracing of non-paraxial rays, as opposed to mathematical estimates of aberrations based on paraxial ray-traces. The geometrical ray-tracing employed here is completely analogous to ray-tracing as conventionally understood in the realm of photon optics, with the major difference being that in electron optics the lens is simply a smoothly varying electric field in vacuum, formed by precisely machined electrodes. Ray-tracing in this context, therefore, relies upon a model of the electrostatic field inside the focusing column to provide the mathematical description of the "lens" being traced. This work relied fundamentally on the boundary element method (BEM) for this electric field model. In carrying out this research the authors discovered that higher accuracy in the field model was essential if aberrations were to be reliably assessed using direct ray-tracing. This led to some work in testing alternative techniques for modeling the electrostatic field. Ultimately, the necessary accuracy was attained using a BEM

  10. Evaluation of the bleached human enamel by Scanning Electron Microscopy

    DEFF Research Database (Denmark)

    Miranda, Carolina Baptista; Pagani, Clovis; Benetti, Ana Raquel;

    2005-01-01

    Electron Microscopy (SEM). Materials and Methods: Twenty intact human third molars extracted for orthodontic reasons were randomly divided into four groups (n=5) treated as follows: G1- storage in artificial saliva (control group); G2- four 30-minute applications of 35% carbamide peroxide (total exposure...... analysis performing gold sputter coating under vacuum and were examined using 15kV at 500x and 2000x magnification. Results: Morphological alterations on the enamel surface were similarly detected after bleaching with either 35% carbamide peroxide or 35% hydrogen peroxide. Surface porosities were...

  11. Development of a fast electromagnetic shutter for compressive sensing imaging in scanning transmission electron microscopy

    CERN Document Server

    Béché, Armand; Freitag, Bert; Verbeeck, Jo

    2015-01-01

    The concept of compressive sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic shutter placed in the condenser plane of a STEM is proposed. The shutter blanks the beam following a random pattern while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both medium scale and high resolution are acquired and then reconstructed based on a discrete cosine algorithm. The obtained results confirm the predicted usefulness of compressive sensing in experimental STEM even though some remaining artifacts need to be resolved.

  12. Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography.

    Science.gov (United States)

    Jesse, S; Chi, M; Belianinov, A; Beekman, C; Kalinin, S V; Borisevich, A Y; Lupini, A R

    2016-01-01

    Electron microscopy is undergoing a transition; from the model of producing only a few micrographs, through the current state where many images and spectra can be digitally recorded, to a new mode where very large volumes of data (movies, ptychographic and multi-dimensional series) can be rapidly obtained. Here, we discuss the application of so-called "big-data" methods to high dimensional microscopy data, using unsupervised multivariate statistical techniques, in order to explore salient image features in a specific example of BiFeO3 domains. Remarkably, k-means clustering reveals domain differentiation despite the fact that the algorithm is purely statistical in nature and does not require any prior information regarding the material, any coexisting phases, or any differentiating structures. While this is a somewhat trivial case, this example signifies the extraction of useful physical and structural information without any prior bias regarding the sample or the instrumental modality. Further interpretation of these types of results may still require human intervention. However, the open nature of this algorithm and its wide availability, enable broad collaborations and exploratory work necessary to enable efficient data analysis in electron microscopy. PMID:27211523

  13. Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography

    Science.gov (United States)

    Jesse, S.; Chi, M.; Belianinov, A.; Beekman, C.; Kalinin, S. V.; Borisevich, A. Y.; Lupini, A. R.

    2016-05-01

    Electron microscopy is undergoing a transition; from the model of producing only a few micrographs, through the current state where many images and spectra can be digitally recorded, to a new mode where very large volumes of data (movies, ptychographic and multi-dimensional series) can be rapidly obtained. Here, we discuss the application of so-called “big-data” methods to high dimensional microscopy data, using unsupervised multivariate statistical techniques, in order to explore salient image features in a specific example of BiFeO3 domains. Remarkably, k-means clustering reveals domain differentiation despite the fact that the algorithm is purely statistical in nature and does not require any prior information regarding the material, any coexisting phases, or any differentiating structures. While this is a somewhat trivial case, this example signifies the extraction of useful physical and structural information without any prior bias regarding the sample or the instrumental modality. Further interpretation of these types of results may still require human intervention. However, the open nature of this algorithm and its wide availability, enable broad collaborations and exploratory work necessary to enable efficient data analysis in electron microscopy.

  14. Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography.

    Science.gov (United States)

    Jesse, S; Chi, M; Belianinov, A; Beekman, C; Kalinin, S V; Borisevich, A Y; Lupini, A R

    2016-05-23

    Electron microscopy is undergoing a transition; from the model of producing only a few micrographs, through the current state where many images and spectra can be digitally recorded, to a new mode where very large volumes of data (movies, ptychographic and multi-dimensional series) can be rapidly obtained. Here, we discuss the application of so-called "big-data" methods to high dimensional microscopy data, using unsupervised multivariate statistical techniques, in order to explore salient image features in a specific example of BiFeO3 domains. Remarkably, k-means clustering reveals domain differentiation despite the fact that the algorithm is purely statistical in nature and does not require any prior information regarding the material, any coexisting phases, or any differentiating structures. While this is a somewhat trivial case, this example signifies the extraction of useful physical and structural information without any prior bias regarding the sample or the instrumental modality. Further interpretation of these types of results may still require human intervention. However, the open nature of this algorithm and its wide availability, enable broad collaborations and exploratory work necessary to enable efficient data analysis in electron microscopy.

  15. Endogenous pneumoconiosis: Analytical scanning electron microscopic analysis of a case.

    Science.gov (United States)

    Galeotti, Jonathan; Sporn, Thomas A; Ingram, Peter; Wahidi, Momen M; Roggli, Victor L

    2016-01-01

    Pneumoconiosis is often considered a disease of the lung initiated by exposure to dust or other airborne particles, resulting in injury to the lungs. The term "endogenous pneumoconiosis" has been used in the literature to describe the deposition of compounds on the elastic fibers of the lung, usually in the setting of cardiac failure. In the case we present here, the patient aspirated a foreign body resulting in damage to the lung tissue and subsequent deposition of endogenous compounds on the elastic fibers of the pulmonary parenchyma and vasculature. We determined the composition of this mineral and mapped the distribution of elements using a combination of backscattered electron microscopy and energy dispersive spectrometry. PMID:27281119

  16. Field-emission scanning electron microscopy of the internal cellular organization of fungi

    NARCIS (Netherlands)

    Muller, W.H.; Aelst, van A.C.; Humbel, B.M.; Krift, van der T.P.; Boekhout, T.

    2000-01-01

    Internal viewing of the cellular organization of hyphae by scanning electron microscopy is an alternative to observing sectioned fungal material with a transmission electron microscope. To study cytoplasmic organelles in the hyphal cells of fungi by SEM, colonies were chemically fixed with glutarald

  17. Thin-film thickness measurement using x-ray peak ratioing in the scanning electron microscope

    International Nuclear Information System (INIS)

    The procedure used to measure laser target film thickness using a scanning electron microscope is summarized. This method is generally applicable to any coating on any substrate as long as the electron energy is sufficient to penetrate the coating and the substrate produces an x-ray signal which can pass back through the coating and be detected

  18. Revealing the 1 nm/s Extensibility of Nanoscale Amorphous Carbon in a Scanning Electron Microscope

    DEFF Research Database (Denmark)

    Zhang, Wei

    2013-01-01

    In an ultra-high vacuum scanning electron microscope, the edged branches of amorphous carbon film (∼10 nm thickness) can be continuously extended with an eye-identifying speed (on the order of ∼1 nm/s) under electron beam. Such unusual mobility of amorphous carbon may be associated with deformation...

  19. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    Energy Technology Data Exchange (ETDEWEB)

    Zaka, Fowzia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2016-03-21

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  20. Scanning Electron Microscopy (SEM) Procedure for HE Powders on a LEO 438VP System

    Energy Technology Data Exchange (ETDEWEB)

    Zaka, Fowzia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Energetic Materials Center

    2016-03-08

    This method describes the characterization of HE powders by Scanning Electron Microscopy (SEM). HE particles are dispersed onto an aluminum standard SEM specimen mount. Electron micrographs are collected at various magnifications (150 to 10,000 X) depending on HE particle size.

  1. Glass for parenteral products: a surface view using the scanning electron microscope.

    Science.gov (United States)

    Roseman, T J; Brown, J A; Scothorn, W W

    1976-01-01

    The scanning electron microscope was utilized to explore the internal surface of glass ampuls and vials used in parenteral products. The surface topography of USP Type I borosilicate glass containers was viewed after exposure to "sulfur," ammonium bifluoride, and sulfuric acid treatments. The scanning electron micrographs showed startling differences in the appearance of the surface regions. "Sulfur treatment" of ampuls was associated with a pitting of the surface and the presence of sodium sulfate crystals. The sulfur treatment of vials altered the glass surface in a characteristically different manner. The dissimilarity between the surface appearances was attributed to the method of sulfur treatment. Ampuls exposed to sulfuric acid solutions at room temperature did not show the pitting associated with the sulfur treatment. Scanning electron micrographs of ammonium bifluoride-treated ampuls showed a relief effect, suggesting that the glass was affected by the bifluoride solution but that sufficient stripping of the surface layer did not occur to remove the pits associated with the sulfur treatment. Flakes emanating from the glass were identified with the aid of the electron microprobe. Scanning electron micrographs showed that these vitreous flakes resulted from a delamination of a thin layer of the glass surface. It is concluded that the scanning electron microscope, in conjunction with other analytical techniques, is a valuable tool in assessing the quality of glass used for parenteral products. The techniques studied should be of particular importance to the pharmaceutical industry where efforts are being made to reduce the levels of particulate matter in parenteral dosage forms.

  2. Low Energy Scanned Electron-Beam Dose Distribution in Thin Layers

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Hjortenberg, P. E.; Pedersen, Walther Batsberg

    1975-01-01

    Thin radiochromic dye film dosimeters, calibrated by means of calorimetry, make possible the determination of absorbed-dose distributions due to low-energy scanned electron beam penetrations in moderately thin coatings and laminar media. For electrons of a few hundred keV, calibrated dosimeters...... on different backings (wood, aluminum, and iron) for scanned electron beams (Emax = 400 keV) having a broad energy spectrum and diffuse incidence, such as those used in radiation curing of coatings, textiles, plastics, etc. Theoretical calculations of such distributions of energy depositions are relatively...

  3. Sub-micron imaging of buried integrated circuit structures using scanning confocal electron microscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, S. P.; Levine, Z.; Zaluzec, N. J.; Materials Science Division; Northern Arizona Univ.; NIST

    2002-09-09

    Two-dimensional images of model integrated circuit components were collected using the technique of scanning confocal electron microscopy. For structures embedded about 5 {mu}m below the surface of a silicon oxide dielectric, a lateral resolution of 76{+-}9 nm was measured. Elemental mapping via x-ray emission spectrometry is demonstrated. A parallax analysis of images taken for various tilt angles to the electron beam allowed determination of the spacing between two wiring planes. The results show that scanning confocal electron microscopy is capable of probing buried structures at resolutions that will be necessary for the inspection of next-generation integrated circuit technology.

  4. Thermal Properties of Materials Characterized by Scanning Electron-Acoustic Microscopy

    Institute of Scientific and Technical Information of China (English)

    GAO Chun-Ming; ZHANG Shu-Yi; ZHANG Zhong-Ning; SHUI Xiu-Ji; JIANG Tao

    2005-01-01

    @@ A modified technique of scanning electron-acoustic microscopy is employed to determine thermal diffusivity of materials. Using the dependence of the electron-acoustic signal on modulation frequency of the electron beam,the thermal diffusivity of materials is characterized based on a simplified thermoelastic theory. The thermal diffusivities of several metals characterized by the modified scanning electron-acoustic microscopy are in good agreement with the referential values of the corresponding materials, which proves that the scanning electronacoustic microscopy can be used to characterize the thermal diffusivity of materials effectively. In addition, for micro-inhomogeneous materials, such as biological tissues, the macro-effective (average) thermal diffusivities are characterized by the technique.

  5. Nanometres-resolution Kikuchi patterns from materials science specimens with transmission electron forward scatter diffraction in the scanning electron microscope.

    Science.gov (United States)

    Brodusch, N; Demers, H; Gauvin, R

    2013-04-01

    A charge-coupled device camera of an electron backscattered diffraction system in a scanning electron microscope was positioned below a thin specimen and transmission Kikuchi patterns were collected. Contrary to electron backscattered diffraction, transmission electron forward scatter diffraction provides phase identification and orientation mapping at the nanoscale. The minimum Pd particle size for which a Kikuchi diffraction pattern was detected and indexed reliably was 5.6 nm. An orientation mapping resolution of 5 nm was measured at 30 kV. The resolution obtained with transmission electron forward scatter diffraction was of the same order of magnitude than that reported in electron nanodiffraction in the transmission electron microscope. An energy dispersive spectrometer X-ray map and a transmission electron forward scatter diffraction orientation map were acquired simultaneously. The high-resolution chemical, phase and orientation maps provided at once information on the chemical form, orientation and coherency of precipitates in an aluminium-lithium 2099 alloy.

  6. Extents of scanning electron microscopy and the energy dispersive system in asbestos identification

    International Nuclear Information System (INIS)

    Optical microscopy and Scanning electron microscopy are widely applied in the identification of asbestos in the environment. This work makes an analysis of the extents and limitations of the Scanning electron microscope in combination with the energy dispersive systems in the asbestos identification. Equipment and reagents: Scanning electron microscope Joel Model 35 C F; Energy Dispersive System with Si/Li X-ray detector and Be window. Certified Asbestos Standards SPI-supplies. Commercial asbestos, samples A and B. Procedure; the asbestos standards as well as the samples to be analyzed are prepared separately dispersing a few quantity of the same in ethanol by means of an ultrasonic bath. For the observation of the morphology by the Scanning electron microscope, standards and samples separately are placed on a base or support and then covered with a gold film using a vacuum evaporator. For the microanalysis by means of the energy dispersive systems, standards and samples separately are fixed on graphite supports and were coated with a graphite film with a vacuum evaporator. Results.Morphological analysis. The samples were observed in the Scanning electron microscope for the morphological analysis and in the energy dispersive system for the microanalysis. (Author)

  7. Examination of mycological samples by means of the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    M. Thibaut

    1973-04-01

    Full Text Available Three species of Siphomycetes: Rhizopus arhizus, Rhizopus equinus and Rhizopus nigricans, as well as a Septomycete: Emericella nidulans, have been examined by means of a scanning electron microscope. Among the difjerent Rhizopus, this technique showed differences in the appearance of the sporangia. In Emericella nidulans, scanning microscopy enábled one to ascertain that the "Hull cells" were completely hollow and also demonstrated the ornemented aspect of the ascospores.

  8. A compact multipurpose nanomanipulator for use inside a scanning electron microscope

    International Nuclear Information System (INIS)

    A compact, two-stage nanomanipulator was designed and built for use inside a scanning electron microscope. It consists of a fine stage employing piezostacks that provide a 15 μm range in three dimensions and a coarse stage based on commercially available stick-slip motors. Besides the fabrication of enhanced probes for scanning probe microscopy and the enhancement of electron field emitters, other novel manipulation processes were developed, such as locating, picking up, and positioning small nanostructures with an accuracy of ∼10 nm. In combination with in situ I-V experiments, welding, and etching, this results in a multipurpose nanofactory, enabling a new range of experiments.

  9. Probing cytotoxicity of nanoparticles and organic compounds using scanning proton microscopy, scanning electron microscopy and fluorescence microscopy

    Science.gov (United States)

    Tong, Yongpeng; Li, Changming; Liang, Feng; Chen, Jianmin; Zhang, Hong; Liu, Guoqing; Sun, Huibin; Luong, John H. T.

    2008-12-01

    Scanning proton microscopy, scanning electron microscopy (SEM) and fluorescence microscopy have been used to probe the cytotoxicity effect of benzo[a]pyrene (BaP), ethidium bromide (EB) and nanoparticles (ZnO, Al 2O 3 and TiO 2) on a T lymphoblastic leukemia Jurkat cell line. The increased calcium ion (from CaCl 2) in the culture medium stimulated the accumulation of BaP and EB inside the cell, leading to cell death. ZnO, Al 2O 3 and TiO 2 nanoparticles, however, showed a protective effect against these two organic compounds. Such inorganic nanoparticles complexed with BaP or EB which became less toxic to the cell. Fe 2O 3 nanoparticles as an insoluble particle model scavenged by macrophage were investigated in rats. They were scavenged out of the lung tissue about 48 h after infection. This result suggest that some insoluble inorganic nanoparticles of PM (particulate matters) showed protective effects on organic toxins induced acute toxic effects as they can be scavenged by macrophage cells. Whereas, some inorganic ions such as calcium ion in PM may help environmental organic toxins to penetrate cell membrane and induce higher toxic effect.

  10. Probing cytotoxicity of nanoparticles and organic compounds using scanning proton microscopy, scanning electron microscopy and fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tong Yongpeng [Institute of Nuclear Techniques, Shenzhen University, Nanhai Avenue 3688, Shenzhen 518060 (China)], E-mail: yongpengt@yahoo.com.cn; Li Changming [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457 (Singapore); Liang Feng [Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai 200025 (China); Chen Jianmin [Shenzhen Municipal Hospital for Chronic Disease Control and Prevention, Guangdong 518020 (China); Zhang Hong; Liu Guoqing; Sun Huibin [Institute of Nuclear Techniques, Shenzhen University, Nanhai Avenue 3688, Shenzhen 518060 (China); Luong, John H.T. [Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, H4P 2R2 (Canada)

    2008-12-15

    Scanning proton microscopy, scanning electron microscopy (SEM) and fluorescence microscopy have been used to probe the cytotoxicity effect of benzo[a]pyrene (BaP), ethidium bromide (EB) and nanoparticles (ZnO, Al{sub 2}O{sub 3} and TiO{sub 2}) on a T lymphoblastic leukemia Jurkat cell line. The increased calcium ion (from CaCl{sub 2}) in the culture medium stimulated the accumulation of BaP and EB inside the cell, leading to cell death. ZnO, Al{sub 2}O{sub 3} and TiO{sub 2} nanoparticles, however, showed a protective effect against these two organic compounds. Such inorganic nanoparticles complexed with BaP or EB which became less toxic to the cell. Fe{sub 2}O{sub 3} nanoparticles as an insoluble particle model scavenged by macrophage were investigated in rats. They were scavenged out of the lung tissue about 48 h after infection. This result suggest that some insoluble inorganic nanoparticles of PM (particulate matters) showed protective effects on organic toxins induced acute toxic effects as they can be scavenged by macrophage cells. Whereas, some inorganic ions such as calcium ion in PM may help environmental organic toxins to penetrate cell membrane and induce higher toxic effect.

  11. Morphology and deflection properties of bat wing sensory hairs: scanning electron microscopy, laser scanning vibrometry, and mechanics model.

    Science.gov (United States)

    Sterbing-D'Angelo, S J; Liu, H; Yu, M; Moss, C F

    2016-01-01

    Bat wings are highly adaptive airfoils that enable demanding flight maneuvers, which are performed with astonishing robustness under turbulent conditions, and stability at slow flight velocities. The bat wing is sparsely covered with microscopically small, sensory hairs that are associated with tactile receptors. In a previous study we demonstrated that bat wing hairs are involved in sensing airflow for improved flight maneuverability. Here, we report physical measurements of these hairs and their distribution on the wing surface of the big brown bat, Eptesicus fuscus, based on scanning electron microscopy analyses. The wing hairs are strongly tapered, and are found on both the dorsal and ventral wing surfaces. Laser scanning vibrometry tests of 43 hairs from twelve locations across the wing of the big brown bat revealed that their natural frequencies inversely correlate with length and range from 3.7 to 84.5 kHz. Young's modulus of the average wing hair was calculated at 4.4 GPa, which is comparable with rat whiskers or arthropod airflow-sensing hairs. PMID:27545727

  12. Semi-empirical model for the generation of dose distributions produced by a scanning electron beam

    International Nuclear Information System (INIS)

    There are linear accelerators (Sagittaire and Saturne accelerators produced by Compagnie Generale de Radiologie (CGR/MeV) Corporation) which produce broad, flat electron fields by magnetically scanning the relatively narrow electron beam as it emerges from the accelerator vacuum system. A semi-empirical model, which mimics the scanning action of this type of accelerator, was developed for the generation of dose distributions in homogeneous media. The model employs the dose distributions of the scanning electron beams. These were measured with photographic film in a polystyrene phantom by turning off the magnetic scanning system. The mean deviation calculated from measured dose distributions is about 0.2%; a few points have deviations as large as 2 to 4% inside of the 50% isodose curve, but less than 8% outside of the 50% isodose curve. The model has been used to generate the electron beam library required by a modified version of a commercially-available computerized treatment-planning system. (The RAD-8 treatment planning system was purchased from the Digital Equipment Corporation. It is currently available from Electronic Music Industries

  13. Study on the parameters of the scanning system for the 300 keV electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Leo, K. W.; Chulan, R. M., E-mail: leo@nm.gov.my; Hashim, S. A.; Baijan, A. H.; Sabri, R. M.; Mohtar, M.; Glam, H.; Lojius, L.; Zahidee, M.; Azman, A.; Zaid, M. [Malaysian Nuclear Agency, Bangi, 43000 Kajang. Selangor (Malaysia)

    2016-01-22

    This paper describes the method to identify the magnetic coil parameters of the scanning system. This locally designed low energy electron accelerator with the present energy of 140 keV will be upgraded to 300 keV. In this accelerator, scanning system is required to deflect the energetic electron beam across a titanium foil in vertical and horizontal direction. The excitation current of the magnetic coil is determined by the energy of the electron beam. Therefore, the magnetic coil parameters must be identified to ensure the matching of the beam energy and excitation coil current. As the result, the essential parameters of the effective lengths for X-axis and Y-axis have been found as 0.1198 m and 0.1134 m and the required excitation coil currents which is dependenton the electron beam energies have be identified.

  14. Note: Electron energy spectroscopy mapping of surface with scanning tunneling microscope

    Science.gov (United States)

    Li, Meng; Xu, Chunkai; Zhang, Panke; Li, Zhean; Chen, Xiangjun

    2016-08-01

    We report a novel scanning probe electron energy spectrometer (SPEES) which combines a double toroidal analyzer with a scanning tunneling microscope to achieve both topography imaging and electron energy spectroscopy mapping of surface in situ. The spatial resolution of spectroscopy mapping is determined to be better than 0.7 ± 0.2 μm at a tip sample distance of 7 μm. Meanwhile, the size of the field emission electron beam spot on the surface is also measured, and is about 3.6 ± 0.8 μm in diameter. This unambiguously demonstrates that the spatial resolution of SPEES technique can be much better than the size of the incident electron beam.

  15. Scanning electron microscope images of uncoated microfossils: applications, perspectives and limitations

    OpenAIRE

    Spezzaferri, Silvia; Neururer, Christoph; Pirkenseer, Claudius; Grobéty, Bernard

    2007-01-01

    We present a recently developed method using a field emission scanning electron microscope (FEG) to view and photograph microfossil specimens that are not coated by conductive material. The FEG microscope provides high electron flux and offers the option to capture images at low beam voltage. Balancing incident energy with absorbed energy from the detector leads to charge-free images of non-conductive material. As an example of the application, we show images of planktonic foraminifers and os...

  16. Two-photon Induced Hot Electron Transfer to a Single Molecule in a Scanning Tunneling Microscope

    OpenAIRE

    Wu, Shiwei; Ho, Wilson

    2010-01-01

    The junction of a scanning tunneling microscope (STM) operating in the tunneling regime was irradiated with femtosecond laser pulses. A photo-excited hot electron in the STM tip resonantly tunnels into an excited state of a single molecule on the surface, converting it from the neutral to the anion. The electron transfer rate depends quadratically on the incident laser power, suggesting a two-photon excitation process. This nonlinear optical process is further confirmed by the polarization me...

  17. Modification of Skin Surface Biopsy for Scanning Electron Microscopic Observation of Superficial Fungal Infection

    OpenAIRE

    高垣, 謙二; 山田, 義貴; 川崎, 洋司; 大畑, 力; 地土井, 襄爾

    1984-01-01

    A modified skin surface biopsy for scanning electron microscopic observation of superficial fungal infection was introduced. Our method has the following advantages which are adequate for routine ultrastructural investigation on superficial fungal infections : 1) atraumatic, 2) convenient, 3) able to obtain a wide area, and 4) minimal chance of getting artifacts.

  18. Submolecular Electronic Mapping of Single Cysteine Molecules by in Situ Scanning Tunneling Imaging

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nazmutdinov, R. R.;

    2009-01-01

    We have used L-Cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocou...

  19. Scanning electron microscopy of dentition: methodology and ultrastructural morphology of tooth wear.

    Science.gov (United States)

    Shkurkin, G V; Almquist, A J; Pfeihofer, A A; Stoddard, E L

    1975-01-01

    Scanning electron micrographs were taken of sets of human molars-those of paleo-Indians used in mastication of, ostensibly, a highly abrasive diet, and those of contemporary Americans. Different ultrastructural patterns of enamel wear were observed between the groups. PMID:1090642

  20. Carbon-fiber tips for scanning probe microscopes and molecular electronics experiments

    NARCIS (Netherlands)

    Rubio-Bollinger, G.; Castellanos-Gomez, A.; Bilan, S.; Zotti, L.A.; Arroyo, C.R.; Agraït, N.; Cuevas, J.

    2012-01-01

    We fabricate and characterize carbon-fiber tips for their use in combined scanning tunneling and force microscopy based on piezoelectric quartz tuning fork force sensors. An electrochemical fabrication procedure to etch the tips is used to yield reproducible sub-100-nm apex. We also study electron t

  1. Morphologic differences observed by scanning electron microscopy according to the reason for pseudophakic IOL explantation

    DEFF Research Database (Denmark)

    Fernandez-Buenaga, Roberto; Alio, Jorge L.; Ramirez, Jose M.;

    2015-01-01

    Purpose To compare variations in surface morphology, as studied by scanning electron microscopy (SEM), of explanted intraocular lenses (IOLs) concerning the cause leading to the explantation surgery. Methods In this prospective multicenter study, explanted IOLs were analyzed by SEM and energy-dis...

  2. Scanning electron microscopy and X-ray spectroscopy applied to mycelial phase of sporothrix schenckii

    Directory of Open Access Journals (Sweden)

    M. Thibaut

    1975-04-01

    Full Text Available Scanning electron microscopy applied to the mycelial phase of Sporothrix schenckii shows a matted mycelium with conidia of a regular pattern. X-Ray microanalysis applied in energy dispersive spectroscopy and also in wavelength dispersive spectroscopy reveals the presence of several elements of Mendeleef's classification.

  3. Focused Ion Beam - Scanning Electron Microscopy Applied to Electrically Insulating Materials

    NARCIS (Netherlands)

    de Winter, D.A.M.

    2015-01-01

    The Focused Ion Beam – Scanning Electron Microscope (FIB-SEM) is a versatile instrument originating from the semiconductor industry. The FIB is used to produce cross sections of pre-defined locations of interest, which are imaged and analyzed with the SEM. Repeated FIB cross sectioning and subsequen

  4. Scanning electron microscopy of dentition: methodology and ultrastructural morphology of tooth wear.

    Science.gov (United States)

    Shkurkin, G V; Almquist, A J; Pfeihofer, A A; Stoddard, E L

    1975-01-01

    Scanning electron micrographs were taken of sets of human molars-those of paleo-Indians used in mastication of, ostensibly, a highly abrasive diet, and those of contemporary Americans. Different ultrastructural patterns of enamel wear were observed between the groups.

  5. Study of the grasping spines and teeth of 6 chaetognath species observed by scanning electron microscopy.

    Science.gov (United States)

    Moreno, I

    1979-01-01

    The grasping spines and teeth of 6 species of Chaetognatha have been studied with the scanning electron microscope, describing in the grasping spines: curvature, surface, ridge and insertion and in the teeth, its characters and their arrangement on the head. PMID:507374

  6. An Anomalous Contrast of Insulators in Scanning Electron Microscope: The Split Image

    OpenAIRE

    Xie, Lilin; Zhang, Xiaona

    2016-01-01

    A novel phenomenon of anomalous contrast in scanning electron microscope when the instrument is used to observe an insulator specimen with a wolfram probe, we called double imaging, is reported in this article. We give a detail analysis of this phenomenon in its occurrence, and discuss the influence of the added probe to internal electric field which lead to the occurrence of double imaging.

  7. Atomic-resolution scanning transmission electron microscopy through 50-nm-thick silicon nitride membranes

    OpenAIRE

    Ramachandra, Ranjan; Demers, Hendrix; de Jonge, Niels

    2011-01-01

    Silicon nitride membranes can be used for windows of environmental chambers for in situ electron microscopy. We report that aberration corrected scanning transmission electron microscopy (STEM) achieved atomic resolution on gold nanoparticles placed on both sides of a 50-nm-thick silicon nitride membrane at 200 keV electron beam energy. Spatial frequencies of 1∕1.2 Å were visible for a beam semi-angle of 26.5 mrad. Imaging though a 100-nm-thick membrane was also tested. The achieved imaging c...

  8. Correlative in vivo 2 photon and focused ion beam scanning electron microscopy of cortical neurons.

    Directory of Open Access Journals (Sweden)

    Bohumil Maco

    Full Text Available Correlating in vivo imaging of neurons and their synaptic connections with electron microscopy combines dynamic and ultrastructural information. Here we describe a semi-automated technique whereby volumes of brain tissue containing axons and dendrites, previously studied in vivo, are subsequently imaged in three dimensions with focused ion beam scanning electron microcopy. These neurites are then identified and reconstructed automatically from the image series using the latest segmentation algorithms. The fast and reliable imaging and reconstruction technique avoids any specific labeling to identify the features of interest in the electron microscope, and optimises their preservation and staining for 3D analysis.

  9. High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy

    CERN Document Server

    Tate, Mark W; Chamberlain, Darol; Nguyen, Kayla X; Hovden, Robert M; Chang, Celesta S; Deb, Pratiti; Turgut, Emrah; Heron, John T; Schlom, Darrell G; Ralph, Daniel C; Fuchs, Gregory D; Shanks, Katherine S; Philipp, Hugh T; Muller, David A; Gruner, Sol M

    2015-01-01

    We describe a hybrid pixel array detector (EMPAD - electron microscope pixel array detector) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128 x 128 pixel detector consists of a 500 um thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit (ASIC). The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as loc...

  10. Characterization of non-conductive materials using field emission scanning electron microscopy

    Science.gov (United States)

    Cao, Cong; Gao, Ran; Shang, Huayan; Peng, Tingting

    2016-01-01

    With the development of science and technology, field emission scanning electron microscope (FESEM) plays an important role in nano-material measurements because of its advantages of high magnification, high resolution and easy operation. A high-quality secondary electron image is a significant prerequisite for accurate and precise length measurements. In order to obtain high-quality secondary electron images, the conventional treatment method for non-conductive materials is coating conductive films with gold, carbon or platinum to reduce charging effects, but this method will cover real micro structures of materials, change the sample composition properties and meanwhile introduce a relatively big error to nano-scale microstructure measurements. This paper discusses how to reduce or eliminate the impact of charging effects on image quality to the greatest extent by changing working conditions, such as voltage, stage bias, scanning mode and so on without treatment of coating, to obtain real and high-quality microstructure information of materials.

  11. A compilation of cold cases using scanning electron microscopy at the University of Rhode Island

    Science.gov (United States)

    Platek, Michael J.; Gregory, Otto J.

    2015-10-01

    Scanning electron microscopy combined with microchemical analysis has evolved into one of the most widely used instruments in forensic science today. In particular, the environmental scanning electron microscope (SEM) in conjunction with energy dispersive spectroscopy (EDS), has created unique opportunities in forensic science in regard to the examination of trace evidence; i.e. the examination of evidence without altering the evidence with conductive coatings, thereby enabling criminalists to solve cases that were previously considered unsolvable. Two cold cases were solved at URI using a JEOL 5900 LV SEM in conjunction with EDS. A cold case murder and a cold missing person case will be presented from the viewpoint of the microscopist and will include sample preparation, as well as image and chemical analysis of the trace evidence using electron microscopy and optical microscopy.

  12. Local imaging of high mobility two-dimensional electron systems with virtual scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pelliccione, M. [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); Bartel, J.; Goldhaber-Gordon, D. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305 (United States); Sciambi, A. [Department of Applied Physics, Stanford University, 348 Via Pueblo Mall, Stanford, California 94305 (United States); Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Pfeiffer, L. N.; West, K. W. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544 (United States)

    2014-11-03

    Correlated electron states in high mobility two-dimensional electron systems (2DESs), including charge density waves and microemulsion phases intermediate between a Fermi liquid and Wigner crystal, are predicted to exhibit complex local charge order. Existing experimental studies, however, have mainly probed these systems at micron to millimeter scales rather than directly mapping spatial organization. Scanning probes should be well-suited to study the spatial structure of these states, but high mobility 2DESs are found at buried semiconductor interfaces, beyond the reach of conventional scanning tunneling microscopy. Scanning techniques based on electrostatic coupling to the 2DES deliver important insights, but generally with resolution limited by the depth of the 2DES. In this letter, we present our progress in developing a technique called “virtual scanning tunneling microscopy” that allows local tunneling into a high mobility 2DES. Using a specially designed bilayer GaAs/AlGaAs heterostructure where the tunnel coupling between two separate 2DESs is tunable via electrostatic gating, combined with a scanning gate, we show that the local tunneling can be controlled with sub-250 nm resolution.

  13. ZnO(0001) surfaces probed by scanning tunneling spectroscopy: Evidence for an inhomogeneous electronic structure

    Science.gov (United States)

    Dumont, J.; Hackens, B.; Faniel, S.; Mouthuy, P.-O.; Sporken, R.; Melinte, S.

    2009-09-01

    The stability of the polar Zn-terminated ZnO surface is probed by low-temperature scanning tunneling microscopy and scanning tunneling spectroscopy (STS). Surface states in the bandgap of ZnO are evidenced by STS and their presence is correlated with the local surface corrugation. Very defective surface regions are characterized by a bulk electronic structure showing a wide bandgap while nanometer-scale defect free regions exhibit a narrower bandgap and surface states. We also image atomically resolved (√3 ×√3 )R30° reconstructions on the defect-free areas.

  14. A scanning drift tube apparatus for spatio-temporal mapping of electron swarms

    CERN Document Server

    Korolov, I; Bastykova, N Kh; Donko, Z

    2016-01-01

    A "scanning" drift tube apparatus, capable of mapping of the spatio-temporal evolution of electron swarms, developing between two plane electrodes under the effect of a homogeneous electric field, is presented. The electron swarms are initiated by photoelectron pulses and the temporal distributions of the electron flux are recorded while the electrode gap length (at a fixed electric field strength) is varied. Operation of the system is tested and verified with argon gas, the measured data are used for the evaluation of the electron bulk drift velocity. The experimental results for the space-time maps of the electron swarms - presented here for the first time - also allow clear observation of deviations from hydrodynamic transport. The swarm maps are also reproduced by particle simulations.

  15. Comparison of spatial resolutions obtained with different signal components in scanning electron microscopy.

    Science.gov (United States)

    Merli, P G; Migliori, A; Nacucchi, M; Vittor Antisari, M

    1996-09-01

    Comparative studies on the ultimate spatial resolution of the Scanning Electron Microscope, using different components of the electron signal have been performed on specimens providing compositional contrast. By operating the microscope in conventional way as well as with a specifically designed set-up we have ascertained that the delocalized components of the signal provide a spatial resolution of the order of the beam size, even if the practical use can be limited by the noise. To amplify the contribution of the delocalized components of the signal, as backscattered electrons by a bulk specimen or forward scattered electrons by a thin specimen, we used a device consisting of a plate of a material with high secondary yield placed above or below the sample. An important practical implication arises from this study. A detecting system consisting of a standard Everhart-Thornley detector coupled with a converter of backscattered or transmitted electrons represents a high performance detecting device for low voltage observations. PMID:8961547

  16. Investigation of the thermal processes in electron-beam surface modification by means of a scanning electron beam

    Science.gov (United States)

    Ormanova, M.; Angelov, Vl; Petrov, P.

    2016-03-01

    In this work we present a study of the thermal processes taking place during surface modification of steels performed by a scanning electron beam. The model is based on solving the heat transfer equation by means of Green functions. The thermal field was calculated, together with the size of the zone of structural changes in tool steel samples. The comparison of the zones of thermal treatment as experimentally obtained and theoretically calculated and the corresponding structural changes show a very good agreement.

  17. Separation of image-distortion sources and magnetic-field measurement in scanning electron microscope (SEM).

    Science.gov (United States)

    Płuska, Mariusz; Czerwinski, Andrzej; Ratajczak, Jacek; Katcki, Jerzy; Oskwarek, Lukasz; Rak, Remigiusz

    2009-01-01

    The electron-microscope image distortion generated by electromagnetic interference (EMI) is an important problem for accurate imaging in scanning electron microscopy (SEM). Available commercial solutions to this problem utilize sophisticated hardware for EMI detection and compensation. Their efficiency depends on the complexity of distortions influence on SEM system. Selection of a proper method for reduction of the distortions is crucial. The current investigations allowed for a separation of the distortions impact on several components of SEM system. A sum of signals from distortion sources causes wavy deformations of specimen shapes in SEM images. The separation of various reasons of the distortion is based on measurements of the periodic deformations of the images for different electron beam energies and working distances between the microscope final aperture and the specimen. Using the SEM images, a direct influence of alternating magnetic field on the electron beam was distinguished. Distortions of electric signals in the scanning block of SEM were also separated. The presented method separates the direct magnetic field influence on the electron beam below the SEM final aperture (in the chamber) from its influence above this aperture (in the electron column). It also allows for the measurement of magnetic field present inside the SEM chamber. The current investigations gave practical guidelines for selecting the most efficient solution for reduction of the distortions.

  18. Contrast and decay of cathodoluminescence from phosphor particles in a scanning electron microscope

    International Nuclear Information System (INIS)

    Cathodoluminescence (CL) studies are reported on phosphors in a field emission scanning electron microscope (FESEM). ZnO: Zn and other luminescent powders manifest a bright ring around the periphery of the particles: this ring enhances the contrast. Additionally, particles resting on top of others are substantially brighter than underlying ones. These phenomena are explained in terms of the combined effects of electrons backscattered out of the particles, together with light absorption by the substrate. The contrast is found to be a function of the particle size and the energy of the primary electrons. Some phosphor materials exhibit a pronounced comet-like structure at high scan rates in a CL-image, because the particle continues to emit light after the electron beam has moved to a position without phosphor material. Image analysis has been used to study the loss of brightness along the tail and hence to determine the decay time of the materials. The effect of phosphor saturation on the determination of decay times by CL-microscopy was also investigated. - Highlights: • Contrast enhancement are observed in secondary electron and cathodoluminescent images of phosphor particles sitting on top of others. • Backscattered electrons largely explain the observed contrast enhancement. • After glow effects in CL-micrographs of phosphors enable the determination of decay times. • Phosphor saturation can be used to determine the decay time of individual spectral transitions

  19. Contrast and decay of cathodoluminescence from phosphor particles in a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Engelsen, Daniel den; Harris, Paul G.; Ireland, Terry G., E-mail: terry.ireland@brunel.ac.uk; Fern, George R.; Silver, Jack

    2015-10-15

    Cathodoluminescence (CL) studies are reported on phosphors in a field emission scanning electron microscope (FESEM). ZnO: Zn and other luminescent powders manifest a bright ring around the periphery of the particles: this ring enhances the contrast. Additionally, particles resting on top of others are substantially brighter than underlying ones. These phenomena are explained in terms of the combined effects of electrons backscattered out of the particles, together with light absorption by the substrate. The contrast is found to be a function of the particle size and the energy of the primary electrons. Some phosphor materials exhibit a pronounced comet-like structure at high scan rates in a CL-image, because the particle continues to emit light after the electron beam has moved to a position without phosphor material. Image analysis has been used to study the loss of brightness along the tail and hence to determine the decay time of the materials. The effect of phosphor saturation on the determination of decay times by CL-microscopy was also investigated. - Highlights: • Contrast enhancement are observed in secondary electron and cathodoluminescent images of phosphor particles sitting on top of others. • Backscattered electrons largely explain the observed contrast enhancement. • After glow effects in CL-micrographs of phosphors enable the determination of decay times. • Phosphor saturation can be used to determine the decay time of individual spectral transitions.

  20. Scanning transmission and computer-aided volumic electron microscopy: 3-D modeling of entire cells by electronic imaging

    Science.gov (United States)

    Bron, Christophe; Gremillet, Philip; Launay, D.; Jourlin, Michel; Gautschi, H. P.; Baechi, Thomas; Schuepbach, Joerg

    1990-05-01

    The digital processing of electron microscopic images from serial sections containing laser-induced topographical references allows a 3-D reconstruction at a depth resolution of 30 to 40 nm of entire cells by the use of image analysis methods, as already demonstrated for Transmission Electron Microscopy (TEM) coupled with a video camera. We decided to use a Scanning Transmission Electron Microscope (STEM) to get higher contrast and better resolution at medium magnification. The scanning of our specimens at video frequencies is an attractive and easy way to link a STEM with an image processing system but the hysteresis of the electronic spools responsible for the magnetic deviation of the scanning electron beam induces deformations of images which have to be modelized and corrected before registration. Computer algorithms developed for image analysis and treatment correct the artifacts caused by the use of STEM and by serial sectioning to automatically reconstruct the third dimension of the cells. They permit the normalization of the images through logarithmic processing of the original grey level infonnation. The automatic extraction of cell limits allows to link the image analysis and treatments with image synthesis methods by minimal human intervention. The surface representation and the registered images provide an ultrastructural data base from which quantitative 3-D morphological parameters, as well as otherwise impossible visualizations, can be computed. This 3-D image processing named C.A.V.U.M. for Computer Aided Volumic Ultra-Microscopy offers a new tool for the documentation and analysis of cell ultrastructure and for 3-D morphometric studies at EM magnifications. Further, a virtual observer can be computed in such a way as to simulate a visit of the reconstructed object.

  1. The effect of proteinases (keratinases) in the pathogenesis of Dermatophyte infection using scanning electron microscope

    International Nuclear Information System (INIS)

    Objective: To study the inter-relationship between the stratum corneum of host and the fungal micro-organisms using scanning electron microscopy for a complete understanding of the host parasite relationship. Material and Methods: Skin surface biopsies were obtained two patients suffering from tinea cruris infection. One patient was infected with trichophyton rubrum and the other with epidermophytom floccosum strains. Results: The scanning electron microphotographs obtained from two patients showed a large number of villi in the infected area. The fungal hyphae were seen to placed intercellularly as well seem to be traversing through the corneocytes in many places. Conclusion: From the results observed in this study it could be suggested that the secretion of proteinases from the fungal hyphae together with the mechanical force of the invading organisms in vivo might be playing part in the invasion of the organisms. (author)

  2. Microstructure of the water spider (Argyroneta aquatica using the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Jung-Hoon Kang

    2014-12-01

    Full Text Available This study is aimed to identify the external features of the water spiders (Argyroneta aquatica collected from “The Natural Monument No. 412 Yeoncheon Eundaeri Water Spider Habitat” through observation of their microstructures using a scanning electron microscope. There is no study on the microstructures of the water spiders excluding several studies on protection plans and ecological investigations, thus giving this study considerable academic significance. Based on the scanning electron microscopy analysis, the water spider has eight simple eyes, and both of its lateral simple eyes are stuck together. A lateral bump was confirmed on the upper jaw, and the pedipalps had six joints and the legs had seven joints. The abdomen and sternum of A. aquatica have more hairs compared with those of land spiders, and its structure shows an elongated area of contact with the air bell so that the air bell can become attached to the abdomen better.

  3. Scanning electron microscopy analysis of experimental bone hacking trauma of the mandible.

    Science.gov (United States)

    Alunni-Perret, Véronique; Borg, Cybèle; Laugier, Jean-Pierre; Bertrand, Marie-France; Staccini, Pascal; Bolla, Marc; Quatrehomme, Gérald; Muller-Bolla, Michèle

    2010-12-01

    The authors report on a macroscopic and microscopic study of human mandible bone lesions achieved by a single-blade knife and a hatchet. The aim of this work was to complete the previous data (scanning electron microscopy analysis of bone lesions made by a single-blade knife and a hatchet, on human femurs) and to compare the lesions of the femur with those of the mandible. The results indicate that the mandible is a more fragile bone, but the features observed on the mandible are quite similar to those previously observed on the femur. This work spells out the main scanning electron microscopy characteristics of sharp (bone cutting) and blunt (exerting a pressure on the bone) mechanisms on human bone. Weapon characteristics serve to explain all of these features.

  4. The development of field-emission scanning electron microscopy for imaging biological surfaces.

    Science.gov (United States)

    Pawley, J

    1997-08-01

    This article traces the important milestones in the development of high-resolution, field-emission, scanning electron microscopes (SEM). Such instruments are now capable of producing images of the surfaces of biological specimens that rival, in terms of resolution and contrast, those produced by conventional transmission electron microscopy (TEM). Even though one of the first instruments to produce a useful transmission electron microscope image was, in fact, an early scanning microscope, TEM reached its full potential for biological imaging almost 30 years sooner than did SEM. The main reason for this slow rate of development is the dependence of any scanning technique on source brightness. The only suitable electron source was the field-emission source, originally developed in the 1930's. Making this into a stable and reliable electron source for microscopy required many technical barriers to be overcome. An additional delay may have been caused by the great success that attended the introduction of early SEM instruments. These instruments which employed heated, tungsten hairpin cathodes, were inexpensive and reliable, but they that were also far from optimal in terms of optical performance. Their market success may have engendered the sense of inertia and complacency that further delayed the introduction of low aberrations objective lenses and field-emission sources for almost 20 years after they were first introduced to electron microscopy. In addition, the fact that these early SEMs accustomed users to operating with a much higher beam voltage than was either necessary or wise, lead many to assume that the SEM was incapable of producing high-resolution images of biological surfaces. This left them open to fascination with newer ahd slower techniques that, on balance, were less suitable than optimized SEM for most of their imaging needs. In parallel to these developments in instrumentation, major improvements were also made in the way that the specimen surface

  5. Transmission-scanning electron microscopic observations of selected Eikenella corrodens strains.

    OpenAIRE

    Progulske, A; Holt, S C

    1980-01-01

    The morphology of Eikenella corrodens 333/54-55 (ATCC 23834) and two human periodontal lesion isolates, strains 470 and 373, was examined by transmission and scanning electron microscopy. All strains exhibited a cell envelope characteristic of gram-negative bacteria. Staining with ruthenium red and alcian blue revealed a loosely organized fibrous slime layer associated with the outer surface of the outer membrane. Slime "stabilization" was achieved by incubation of cells with antisera prepare...

  6. Study of Drying Shrinkage Cracking by Lattice Gas Automaton and Environmental Scanning Electron Microscope

    OpenAIRE

    Jankovic, D.

    2005-01-01

    Numerical modeling of moisture flow, drying shrinkage and crack phenomena in cement microstructure, by coupling a Lattice Gas Automaton and a Lattice Fracture Model, highlighted the importance of a shrinkage coefficient (sh) as the most significant parameter for achieving realistic numerical results. Therefore, experiments on drying of cement paste samples were conducted in an Environmental Scanning Electron Microscope to find shrinkage coefficient relating shrinkage deformations and moistur...

  7. Analysis of Particulate Pollution on Foodstuff and Other Items by Environmental Scanning Electron Microscopy

    OpenAIRE

    Giordano, C; U. Bardi; D. GARBINI; Suman, M.

    2011-01-01

    Combustion processes commonly create fine and ultrafine particles whose effects are often harmful to human health. The present study is aimed at providing more data in this field by testing the capability of environmental electron scanning microscopy of detecting and analyzing such particles. For this purpose, we examined a range of samples taken from everyday food items collected in Tuscany. The results showed that, within the examined samples, inorganic particles can be observed in the nano...

  8. Analysis of Femtosecond Laser Assisted Capsulotomy Cutting Edges and Manual Capsulorhexis Using Environmental Scanning Electron Microscopy

    OpenAIRE

    Sebastiano Serrao; Giuseppe Lombardo; Giovanni Desiderio; Lucio Buratto; Domenico Schiano-Lomoriello; Marco Pileri; Marco Lombardo

    2014-01-01

    Purpose. To investigate the structure and irregularity of the capsulotomy cutting edges created by two femtosecond (FS) laser platforms in comparison with manual continuous circular capsulorhexis (CCC) using environmental scanning electron microscopy (eSEM). Methods. Ten anterior capsulotomies were obtained using two different FS laser cataract platforms (LenSx, n=5, and Victus, n=5). In addition, five manual CCC (n=5) were obtained using a rhexis f...

  9. Scanning Electron Microscopy Structure and Firmness of Papain Treated Apple Slices

    OpenAIRE

    Luo, Yaguang; Patterson, Max E.; Swanson, Barry G.

    1992-01-01

    'Mcintosh' apple (Malus domesrica Borkh.) slices were treated with papain. Textural changes were recorded with an Instron Universal Testing Machine. Structural changes and distribution of microorganisms in apple tissues after treatment were observed with a scanning electron microscope (SEM). Apple slices submerg ed in a 1% papain solution were significantly firmer than apple slices submerged in the distilled water control for a 24 hour period (P < 0.05). Three and four days after slicing , a ...

  10. Hyaline articular cartilage dissected by papain: light and scanning electron microscopy and micromechanical studies.

    OpenAIRE

    O'Connor, P; Brereton, J D; Gardner, D.L.

    1984-01-01

    Papain was used to digest the hyaline femoral condylar cartilages of 30 adult Wistar rats. Matrix proteoglycan degradation was assessed by the light microscopy of paraffin sections stained with toluidine blue. The extent of surface structural change was estimated by scanning electron microscopy, and the structural integrity of the hyaline cartilage tested by the controlled impact of a sharp pin. The results demonstrated an early loss of cartilage metachromasia, increasing with time of papain ...

  11. Scanning electron microscopic study of Prosorhynchoides arcuatus (Linton, 1990 (Bucephalidae: Digenea

    Directory of Open Access Journals (Sweden)

    Simone C Cohen

    1995-02-01

    Full Text Available Prosorhynchoides arcuatus (Linton, 1900 from the intestine of Pomatomus saltator (L. from the Atlantic coast of the State of Rio de Janeiro is studied by scanning electron microscopy, with detailed description of tegumental spines. Comments on the synonymy of this species with Bucephalopsis callicotyle Kohn, 1962 are made. The tegument of adult P. arcuatus presents scale like and serrated spines and uniciliated sensory papillae, distributed over the body surface and is compared with other digenetic trematodes.

  12. Scanning electron microscopic observation of Bruch's membrane with the osmium tetroxide treatment.

    OpenAIRE

    Yamamoto, T; Yamashita, H.

    1989-01-01

    Scanning electron microscopic observation of Bruch's membrane was performed after removal of retinal pigment epithelium (RPE) with the osmium tetroxide treatment. Eight human eyes from subjects at various ages (from newborn to 77 years old) were examined in order to investigate aging changes in Bruch's membrane. The collagen fibres of the inner collagenous zone in young eyes formed a tightly interwoven membrane, and the meshes were regular and fine. In old eyes the meshes were irregular and c...

  13. Differentiation of females in Sergentomyia sensu stricto (Diptera: Psychodidae) using scanning electron microscopy of pharyngeal armatures.

    Science.gov (United States)

    Benabdennbi, I; Bombard, S; Braverman, Y; Pesson, B

    1996-03-01

    Scanning electron microscopy of external ornamentation and internal armature of the pharynx was used to identify females of Sergentomyia sensu stricto. Five species from the eastern Mediterranean basin were compared; S. minuta clearly was separated from species of the fallax-group. Within the fallax-group, S. fallax was distinguished readily by its heart-shaped pharynx and the difference in armature between the dorsal and lateral plates.

  14. Simple observation of Streptococcus mutans biofilm by scanning electron microscopy using ionic liquids

    OpenAIRE

    Asahi, Yoko; Miura, Jiro; Tsuda, Tetsuya; Kuwabata, Susumu; Tsunashima, Katsuhiko; Noiri, Yuichiro; Sakata, Takao; Ebisu, Shigeyuki; Hayashi, Mikako

    2015-01-01

    Scanning electron microscopy (SEM) has been successfully used to image biofilms because of its high resolution and magnification. However, conventional SEM requires dehydration and metal coating of biological samples before observation, and because biofilms consist mainly of water, sample dehydration may influence the biofilm structure. When coated with an ionic liquid, which is a kind of salt that exists in the liquid state at room temperature, biological samples for SEM observation do not r...

  15. A scanning electron microscopic study of the patterns of external root resorption under different conditions

    OpenAIRE

    Ravindran Sreeja; Chaudhary Minal; Tumsare Madhuri; Patil Swati; Wadhwan Vijay

    2009-01-01

    Objective: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. Material and Methods: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging fr...

  16. Corneal endothelium of the Magellanic penguin (Spheniscus magellanicus) by scanning electron microscopy.

    Science.gov (United States)

    Pigatto, João A T; Laus, José L; Santos, Jaime M; Cerva, Cristine; Cunha, Luciana S; Ruoppolo, Valéria; Barros, Paulo S M

    2005-12-01

    The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates. PMID:17312730

  17. Electron transport in two-dimensional arrays of gold nanocrystals investigated by scanning electrochemical microscopy.

    Science.gov (United States)

    Liljeroth, Peter; Vanmaekelbergh, Daniël; Ruiz, Virginia; Kontturi, Kyösti; Jiang, Hua; Kauppinen, Esko; Quinn, Bernadette M

    2004-06-01

    This article reports the use of the scanning electrochemical microscope (SECM) to investigate the electronic properties of Langmuir monolayers of alkane thiol protected gold nanocrystals (NCs). A substantial increase in monolayer conductivity upon mechanical compression of the Au NC monolayer is reported for the first time. This may be the room temperature signature of the insulator to metal transition previously reported for comparable silver NC monolayers. Factors influencing the conductivity of the monolayer NC array are discussed. PMID:15174884

  18. Bacterial Biofilm Morphology on a Failing Implant with an Oxidized Surface: A Scanning Electron Microscope Study.

    Science.gov (United States)

    Simion, Massimo; Kim, David M; Pieroni, Stefano; Nevins, Myron; Cassinelli, Clara

    2016-01-01

    This case report provided a unique opportunity to investigate the extent of microbiota infiltration on the oxidized implant surface that has been compromised by peri-implantitis. Scanning electron microscopic analysis confirmed the etiologic role of the bacteria on the loss of supporting structure and the difficulty in complete removal of bacterial infiltration on the implant surface. This case report emphasizes the need to perform definitive surface decontamination on failing dental implants prior to a regeneration procedure. PMID:27333005

  19. A scanning and transmission electron microscopic study of the membranes of chicken egg

    OpenAIRE

    Tan, C K; Chen, T. W.; Chan, H L; Ng, L. S.

    1992-01-01

    Questions regarding the structure of the inner and outer shell membranes of the chicken egg were addressed in this study by correlating observations from light microscopy and scanning and transmission electron microscopy. The egg membrane had a limiting membrane, which measured .9 to .15 pn in thickness and appeared to be a continuous and an impervious layer, but the shell membrane did not. Under the SEM, each membrane was seen to be made up of severa1 fibre ...

  20. Somatic Embryos in Catharanthus roseus: A Scanning Electron Microscopic Study

    OpenAIRE

    Aslam, Junaid; MUJIB, Abdul; Mahendra Prasad SHARMA

    2014-01-01

    Catharanthus roseus (L.) G. Don is an important medicinal plant as it contains several anti-cancerous compounds, like vinblastine and vincristine. Plant tissue culture technology (organogenesis and embryogenesis) has currently been used in fast mass propagating raw materials for secondary metabolite synthesis. In this present communication, scanning electron microscopic (SEM) study of somatic embryos was conducted and discussed. The embryogenic callus was first induced from hypocotyls of in ...

  1. A case of phacolytic glaucoma with anterior lens capsule disruption identified by scanning electron microscopy

    OpenAIRE

    Yoo, Woong-Sun; Kim, Byeong-Jae; Chung, In-Young; Seo, Seong-Wook; Yoo, Ji-Myong; Kim, Seong-Jae

    2014-01-01

    Background Phacolytic glaucoma is induced by lens protein or macrophages that have leaked through a macroscopically intact anterior lens capsule. Here, we report a case of phacolytic glaucoma with anterior lens capsule disruptions visualized by scanning electron microscopy (SEM). Case presentation A 71-year-old man was referred to our institute for increased intraocular pressure (IOP) in the right eye. Slit-lamp biomicroscopic examination revealed corneal edema, the presence of inflammatory c...

  2. Scanning Electron Microscopy of the Pericarp and Testa of Several Sorghum Varieties

    OpenAIRE

    Earp, C. F.; Rooney, L. W.

    1982-01-01

    Pericarp thickness (determined by Z gene) varies greatly among sorghum varieties ranging· from very thin (8 ~ m) to very thick (160 ~m ) . Pericarp thickness also varies within an individuual kernel. The areas below the style and near the hilum are the thickest with the sides of the kernel being thinnest . Scanning electron microscopy was used to document differences in pericarp thickness and to explain milling differences . Varieties with a thick pericarp had starch granules in the mesocarp ...

  3. SEM analysis of ionizing radiation effects in linear integrated circuits. [Scanning Electron Microscope

    Science.gov (United States)

    Stanley, A. G.; Gauthier, M. K.

    1977-01-01

    A successful diagnostic technique was developed using a scanning electron microscope (SEM) as a precision tool to determine ionization effects in integrated circuits. Previous SEM methods radiated the entire semiconductor chip or major areas. The large area exposure methods do not reveal the exact components which are sensitive to radiation. To locate these sensitive components a new method was developed, which consisted in successively irradiating selected components on the device chip with equal doses of electrons /10 to the 6th rad (Si)/, while the whole device was subjected to representative bias conditions. A suitable device parameter was measured in situ after each successive irradiation with the beam off.

  4. METHOD FOR OBSERVATION OF DEEMBEDDED SECTIONS OF FISH GONAD BY SCANNING ELECTRON MICROSCOPY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This article reports a method for examining the intracellular structure of fish gonads using a scanning electron microscope(SEM). The specimen preparation procedure is similar to that for transmission electron microscopy wherein samples cut into semi-thin sections are fixed and embedded in plastic. The embedment matrix was removed by solvents. Risen-free specimens could be observed by SEM. The morphology of matured sperms in the gonad was very clear, and the oocyte internal structures appeared in three-dimensional images. Spheroidal nucleoli and yolk vesicles and several bundles of filaments adhered on the nucleoli could be viewed by SEM for the first time.

  5. Efficient linear phase contrast in scanning transmission electron microscopy with matched illumination and detector interferometry.

    Science.gov (United States)

    Ophus, Colin; Ciston, Jim; Pierce, Jordan; Harvey, Tyler R; Chess, Jordan; McMorran, Benjamin J; Czarnik, Cory; Rose, Harald H; Ercius, Peter

    2016-01-01

    The ability to image light elements in soft matter at atomic resolution enables unprecedented insight into the structure and properties of molecular heterostructures and beam-sensitive nanomaterials. In this study, we introduce a scanning transmission electron microscopy technique combining a pre-specimen phase plate designed to produce a probe with structured phase with a high-speed direct electron detector to generate nearly linear contrast images with high efficiency. We demonstrate this method by using both experiment and simulation to simultaneously image the atomic-scale structure of weakly scattering amorphous carbon and strongly scattering gold nanoparticles. Our method demonstrates strong contrast for both materials, making it a promising candidate for structural determination of heterogeneous soft/hard matter samples even at low electron doses comparable to traditional phase-contrast transmission electron microscopy. Simulated images demonstrate the extension of this technique to the challenging problem of structural determination of biological material at the surface of inorganic crystals. PMID:26923483

  6. Scanning electron acoustic microscopy of residual stresses in ceramics: Theory and experiment

    Science.gov (United States)

    Cantrell, John H.; Qian, Menglu

    1992-01-01

    Several reviews have highlighted a number of applications of scanning electron acoustic microscopy (SEAM) to metals and semiconductors which show that SEAM can provide new information on surface and near-surface features of such materials, but there have been few studies attempting to determine the capabilities of SEAM for characterizing ceramic materials. We have recently observed image contrast in SEAM from residual stress fields induced in brittle materials by Vickers indentations that is strongly dependent on the electron beam chopping frequency. We have also recently developed a three-dimensional mathematical model of signal generation and contrast in SEAM, appropriate to the brittle materials studied, that we use as a starting point in this paper for modeling the effect of residual stress fields on the generated electron acoustic signal. The influence of the electron beam chopping frequency is also considered under restrictive assumptions.

  7. Scanning electron microscopy of cells and tissues under fully hydrated conditions.

    Science.gov (United States)

    Thiberge, Stephan; Nechushtan, Amotz; Sprinzak, David; Gileadi, Opher; Behar, Vered; Zik, Ory; Chowers, Yehuda; Michaeli, Shulamit; Schlessinger, Joseph; Moses, Elisha

    2004-03-01

    A capability for scanning electron microscopy of wet biological specimens is presented. A membrane that is transparent to electrons protects the fully hydrated sample from the vacuum. The result is a hybrid technique combining the ease of use and ability to see into cells of optical microscopy with the higher resolution of electron microscopy. The resolution of low-contrast materials is approximately 100 nm, whereas in high-contrast materials the resolution can reach 10 nm. Standard immunogold techniques and heavy-metal stains can be applied and viewed in the fluid to improve the contrast. Images present a striking combination of whole-cell morphology with a wealth of internal details. A possibility for direct inspection of tissue slices transpires, imaging only the external layer of cells. Simultaneous imaging with photons excited by the electrons incorporates data on material distribution, indicating a potential for multilabeling and specific scintillating markers.

  8. Investigation on gradient material fabrication with electron beam melting based on scanning track control

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new electron beam control system was developed in a general vacuum electron beam machine by assembling with industrial control computer, programmable logic control (PLC), deflection coil, data acquisition card, power amplifier, etc. In this control system, scanning track and energy distribution of electron beam could be edited off-line, real-time adjusted and controlled on-line. Ti-Mo gradient material (GM) with high temperature resistant was fabricated using the technology of electron beam melting. The melting processes include three steps, such as preheating, melting, and homogenizing. The results show that the GM prepared by melting technology has fine appearance, and it has good integrated interface with the Ti alloy. Mo and Ti elements are gradually distributed in the interface of the gradient material. The microstructure close to the Ti alloy base metal is α+β basket-waver grain, and the microstructure close to the GM is a single phase of β solid solution.

  9. Focused ion beam (FIB)/scanning electron microscopy (SEM) in tissue structural research.

    Science.gov (United States)

    Leser, Vladka; Milani, Marziale; Tatti, Francesco; Tkalec, Ziva Pipan; Strus, Jasna; Drobne, Damjana

    2010-10-01

    The focused ion beam (FIB) and scanning electron microscope (SEM) are commonly used in material sciences for imaging and analysis of materials. Over the last decade, the combined FIB/SEM system has proven to be also applicable in the life sciences. We have examined the potential of the focused ion beam/scanning electron microscope system for the investigation of biological tissues of the model organism Porcellio scaber (Crustacea: Isopoda). Tissue from digestive glands was prepared as for conventional SEM or as for transmission electron microscopy (TEM). The samples were transferred into FIB/SEM for FIB milling and an imaging operation. FIB-milled regions were secondary electron imaged, back-scattered electron imaged, or energy dispersive X-ray (EDX) analyzed. Our results demonstrated that FIB/SEM enables simultaneous investigation of sample gross morphology, cell surface characteristics, and subsurface structures. The same FIB-exposed regions were analyzed by EDX to provide basic compositional data. When samples were prepared as for TEM, the information obtained with FIB/SEM is comparable, though at limited magnification, to that obtained from TEM. A combination of imaging, micro-manipulation, and compositional analysis appears of particular interest in the investigation of epithelial tissues, which are subjected to various endogenous and exogenous conditions affecting their structure and function. The FIB/SEM is a promising tool for an overall examination of epithelial tissue under normal, stressed, or pathological conditions.

  10. Scanning electron microscopic analysis of incinerated teeth: An aid to forensic identification

    Directory of Open Access Journals (Sweden)

    Chetan A Pol

    2014-01-01

    Full Text Available Background: Forensic dental identification of victims involved in fire accidents is often a complex and challenging endeavor. Knowledge of the charred human dentition and residues of restorative material can help in the recognition of bodies burned beyond recognition. Aim: To observe the effects of predetermined temperatures on healthy unrestored teeth and different restorative materials in restored teeth, by scanning electron microscope, for the purpose of identification. Materials and Methods: The study was conducted on 135 extracted teeth, which were divided into four groups. Group 1-healthy unrestored teeth, group 2-teeth restored with all ceramic crowns, group 3-teeth restored with class I composite resin and group 4-teeth restored with class I glass ionomer cement (GIC. Results: The scanning electron microscope is useful in the analysis of burned teeth, as it gives fine structural details, requires only a small sample and does not destroy the already fragile specimen. Conclusion: Scanning electron microscope can be a useful tool for the characterization and study of severely burnt teeth for victim identification.

  11. Scanning electron microscopy and transmission electron microscopy study of hot-deformed gamma-TiAl-based alloy microstructure.

    Science.gov (United States)

    Chrapoński, J; Rodak, K

    2006-09-01

    The aim of this work was to assess the changes in the microstructure of hot-deformed specimens made of alloys containing 46-50 at.% Al, 2 at.% Cr and 2 at.% Nb (and alloying additions such as carbon and boron) with the aid of scanning electron microscopy and transmission electron microscopy techniques. After homogenization and heat treatment performed in order to make diverse lamellae thickness, the specimens were compressed at 1000 degrees C. Transmission electron microscopy examinations of specimens after the compression test revealed the presence of heavily deformed areas with a high density of dislocation. Deformation twins were also observed. Dynamically recrystallized grains were revealed. For alloys no. 2 and no. 3, the recovery and recrystallization processes were more extensive than for alloy no. 1.

  12. Conditions required for high quality high magnification images in secondary electron-I scanning electron microscopy.

    Science.gov (United States)

    Peters, K R

    1982-01-01

    High quality of secondary electron (SE) images, taken at useful magnifications of 100,000 to 200,000, require new signal generation and collection methods and new metal coating procedures. High quality is defined as the condition under which image contrast describes accurately the topographic features of the specimen in a size range that approximates the beam diameter. Such high resolution contrasts are produced by the SE (SE-I) generated by a small electron probe on the specimen surface. Tobacco mosiac virus and ferritin molecules deposited on bulk substrates were introduced as test specimens to check the image quality obtained. The SE-I signal contrast could be imaged when SE (SE-III), produced by backscattered electrons (BSE) at the pole piece of the final lens, were eliminated with an electron absorption device attached to the pole piece. This signal collection procedure will be referred to as "Secondary Electron-I Image" (SE-I image) mode. In addition to the SE-III, BSE generate SE-II in the specimen itself. On specimens deposited on bulk gold or platinum, and coated with the same metals SE-II produced a microroughness contrast that limited particle resolution in the SE-I image mode to approximately 10 nm. Reduction of SE-II and enrichment of the signal in SE-I was achieved by using continuous fine crystalline coatings of tantalum, niobium and chromium. By applying these metals in films of approximately 2.0 nm thickness, the SE-I contrast generation was found to be indepedent of the atomic number of the metal. Edge sharpness was improved when the specimens were coated with low atomic number metals. Under these conditions, the quality of images obtained in SE-I image mode equals that of images obtained in TEM from identically coated specimens and was limited only by the size of the topographic details, beam diameter and beam current. PMID:7184136

  13. Image formation mechanisms in scanning electron microscopy of carbon nanotubes, and retrieval of their intrinsic dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Jackman, H., E-mail: henrik.jackman@kau.se [Department of Physics and Electrical Engineering, Karlstad University, SE-651 88 Karlstad (Sweden); Krakhmalev, P. [Department of Mechanical and Materials Engineering, Karlstad University, SE-651 88 Karlstad (Sweden); Svensson, K. [Department of Physics and Electrical Engineering, Karlstad University, SE-651 88 Karlstad (Sweden)

    2013-01-15

    We present a detailed analysis of the image formation mechanisms that are involved in the imaging of carbon nanotubes with scanning electron microscopy (SEM). We show how SEM images can be modelled by accounting for surface enhancement effects together with the absorption coefficient for secondary electrons, and the electron-probe shape. Images can then be deconvoluted, enabling retrieval of the intrinsic nanotube dimensions. Accurate estimates of their dimensions can thereby be obtained even for structures that are comparable to the electron-probe size (on the order of 2 nm). We also present a simple and robust model for obtaining the outer diameter of nanotubes without any detailed knowledge about the electron-probe shape. -- Highlights: Black-Right-Pointing-Pointer We model the image formation of free-standing carbon nanotubes in SEM. Black-Right-Pointing-Pointer The electron-probe shape is characterized from SEM-images. Black-Right-Pointing-Pointer We use the electron-probe shape to deconvolute SEM-images of carbon nanotubes. Black-Right-Pointing-Pointer We present a simple method for retrieval of intrinsic nanotube dimensions.

  14. Atomic-scale mapping of electronic structures across heterointerfaces by cross-sectional scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Interfacial science has received much attention recently based on the development of state-of-the-art analytical tools that can create and manipulate the charge, spin, orbital, and lattice degrees of freedom at interfaces. Motivated by the importance of nanoscale interfacial science that governs device operation, we present a technique to probe the electronic characteristics of heterointerfaces with atomic resolution. In this work, the interfacial characteristics of heteroepitaxial structures are investigated and the fundamental mechanisms that pertain in these systems are elucidated through cross-sectional scanning tunneling microscopy (XSTM). The XSTM technique is employed here to directly observe epitaxial interfacial structures and probe local electronic properties with atomic-level capability. Scanning tunneling microscopy and spectroscopy experiments with atomic precision provide insight into the origin and spatial distribution of electronic properties across heterointerfaces. The first part of this report provides a brief description of the cleavage technique and spectroscopy analysis in XSTM measurements. The second part addresses interfacial electronic structures of several model heterostructures in current condensed matter research using XSTM. Topics to be discussed include high-κ‘s/III–V’s semiconductors, polymer heterojunctions, and complex oxide heterostructures, which are all material systems whose investigation using this technique is expected to benefit the research community. Finally, practical aspects and perspectives of using XSTM in interface science are presented. (topical review)

  15. A high-speed area detector for novel imaging techniques in a scanning transmission electron microscope.

    Science.gov (United States)

    Caswell, T A; Ercius, P; Tate, M W; Ercan, A; Gruner, S M; Muller, D A

    2009-03-01

    A scanning transmission electron microscope (STEM) produces a convergent beam electron diffraction pattern at each position of a raster scan with a focused electron beam, but recording this information poses major challenges for gathering and storing such large data sets in a timely manner and with sufficient dynamic range. To investigate the crystalline structure of materials, a 16x16 analog pixel array detector (PAD) is used to replace the traditional detectors and retain the diffraction information at every STEM raster position. The PAD, unlike a charge-coupled device (CCD) or photomultiplier tube (PMT), directly images 120-200keV electrons with relatively little radiation damage, exhibits no afterglow and limits crosstalk between adjacent pixels. Traditional STEM imaging modes can still be performed by the PAD with a 1.1kHz frame rate, which allows post-acquisition control over imaging conditions and enables novel imaging techniques based on the retained crystalline information. Techniques for rapid, semi-automatic crystal grain segmentation with sub-nanometer resolution are described using cross-correlation, sub-region integration, and other post-processing methods. PMID:19162398

  16. Field emission scanning electron microscopy (FE-SEM) as an approach for nanoparticle detection inside cells.

    Science.gov (United States)

    Havrdova, M; Polakova, K; Skopalik, J; Vujtek, M; Mokdad, A; Homolkova, M; Tucek, J; Nebesarova, J; Zboril, R

    2014-12-01

    When developing new nanoparticles for bio-applications, it is important to fully characterize the nanoparticle's behavior in biological systems. The most common techniques employed for mapping nanoparticles inside cells include transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). These techniques entail passing an electron beam through a thin specimen. STEM or TEM imaging is often used for the detection of nanoparticles inside cellular organelles. However, lengthy sample preparation is required (i.e., fixation, dehydration, drying, resin embedding, and cutting). In the present work, a new matrix (FTO glass) for biological samples was used and characterized by field emission scanning electron microscopy (FE-SEM) to generate images comparable to those obtained by TEM. Using FE-SEM, nanoparticle images were acquired inside endo/lysosomes without disruption of the cellular shape. Furthermore, the initial steps of nanoparticle incorporation into the cells were captured. In addition, the conductive FTO glass endowed the sample with high stability under the required accelerating voltage. Owing to these features of the sample, further analyses could be performed (material contrast and energy-dispersive X-ray spectroscopy (EDS)), which confirmed the presence of nanoparticles inside the cells. The results showed that FE-SEM can enable detailed characterization of nanoparticles in endosomes without the need for contrast staining or metal coating of the sample. Images showing the intracellular distribution of nanoparticles together with cellular morphology can give important information on the biocompatibility and demonstrate the potential of nanoparticle utilization in medicine.

  17. Chemical-state imaging of Li using scanning Auger electron microscopy

    International Nuclear Information System (INIS)

    Highlights: •Scanning Auger electron microscopy is used to image chemical states of Li. •The combined use of AES and EELS signals for the elemental mapping is powerful. •Distribution corresponding to metallic and oxidized states of Li can be imaged. -- Abstract: The demand for measurement tools to detect Li with high spatial resolution and precise chemical sensitivity is increasing with the spread of lithium-ion batteries (LIBs) for use in a wide range of applications. In this work, scanning Auger electron microscopy (SAM) is used to image chemical states of a partially oxidized Li surface on the basis of the Auger electron spectroscopy (AES) and electron energy loss spectroscopy (EELS) data obtained during an oxidation process of a metal Li. We show that distribution of metallic and oxidized states of Li is clearly imaged by mapping the intensity of the corresponding AES and EELS peaks. Furthermore, a tiny difference in the extent of oxidation can be distinguished by comparing the elemental map of an AES peak with that of an EELS peak owing to the different behaviors of those signals to the chemical states of Li

  18. Variable Temperature Setup for Scanning Electron Microscopy in Liquids and Atmospheric Pressure Gaseous Environments

    Science.gov (United States)

    Al-Asadi, Ahmed; Zhang, Jie; Li, Jianbo; Denault, Lauraine; Potyrailo, Radislav; Kolmakov, Andrei

    2014-03-01

    A thermoelectric cooling / heating setup for commercial Quantomix QX WETSEM scanning electron microscopy environmental cells was designed and tested. This addition allows extending ambient pressure in situ studies to be conducted in a wide temperature range both in liquid and gaseous environments. Instead of cooling/heating the entire body of QX-WETCELL, ultrathin polyimide electron transparent membrane window supported by metal mesh on the top of the cell has been used as an agent for heat transfer to/ from the Pelltier element. A butterfly wing of Morph sulkowskyi has been used as a model object in the QX-WETCELL's chamber due to its unique micro/nanostructure and peculiar wettability behavior. The dynamics of the water desorption, condensation and freezing processes were observed complementary using both optical microscopy and Scanning Electron Microscopy in vivo. The observations revel that the initial droplet formation were most likely taking place on the top of the wing ridges due to the waxy component of its surface. In addition, The SEM observation showed that the high intensity electron beam can heat the butterfly wing locally delaying the water condensation and freezing processes.

  19. Probing plasmons in three dimensions by combining complementary spectroscopies in a scanning transmission electron microscope

    Science.gov (United States)

    Hachtel, J. A.; Marvinney, C.; Mouti, A.; Mayo, D.; Mu, R.; Pennycook, S. J.; Lupini, A. R.; Chisholm, M. F.; Haglund, R. F.; Pantelides, S. T.

    2016-04-01

    The nanoscale optical response of surface plasmons in three-dimensional metallic nanostructures plays an important role in many nanotechnology applications, where precise spatial and spectral characteristics of plasmonic elements control device performance. Electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) within a scanning transmission electron microscope have proven to be valuable tools for studying plasmonics at the nanoscale. Each technique has been used separately, producing three-dimensional reconstructions through tomography, often aided by simulations for complete characterization. Here we demonstrate that the complementary nature of the two techniques, namely that EELS probes beam-induced electronic excitations while CL probes radiative decay, allows us to directly obtain a spatially- and spectrally-resolved picture of the plasmonic characteristics of nanostructures in three dimensions. The approach enables nanoparticle-by-nanoparticle plasmonic analysis in three dimensions to aid in the design of diverse nanoplasmonic applications.

  20. Analysing Imaging Signals of Negative-Charging Contrast in Scanning Electron Microscopy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hai-Bo(张海波); FENG Ren-Jian(冯仁剑); Katsumi URA

    2003-01-01

    Negative charging of a specimen may produce the image contrast of yielding the information under the insulating thin film in scanning electron microscopy.To clarify and make good use of the recently developed negative-charging contrast(NCC),we propose a simplified procedure for quantifying secondary electron(SE)imaging signals and report the calculated results.The theoretical considerations and calculations are validated by comparing the calculated relation between the SE signal and the surface potential with measured dynamic characteristics of the NCC images.The results show that in the region of weak negative charging the NCC formation is due to the SE redistribution.The intensity of SE signals decreases with increasing the amount of the SEs returning to the negatively charged surface whose local electric field may attract electrons.This results in the NCC transient characteristics.

  1. In situ nanomechanical testing in focused ion beam and scanning electron microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Gianola, D. S. [Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Institute for Applied Materials, Karlsruhe Institute of Technology, Karlsruhe (Germany); Sedlmayr, A.; Moenig, R.; Kraft, O. [Institute for Applied Materials, Karlsruhe Institute of Technology, Karlsruhe (Germany); Volkert, C. A. [Institute for Materials Physics, Georg-August University of Goettingen, Goettingen (Germany); Major, R. C.; Cyrankowski, E.; Asif, S. A. S.; Warren, O. L. [Hysitron, Inc., Minneapolis, Minnesota 55344 (United States)

    2011-06-15

    The recent interest in size-dependent deformation of micro- and nanoscale materials has paralleled both technological miniaturization and advancements in imaging and small-scale mechanical testing methods. Here we describe a quantitative in situ nanomechanical testing approach adapted to a dual-beam focused ion beam and scanning electron microscope. A transducer based on a three-plate capacitor system is used for high-fidelity force and displacement measurements. Specimen manipulation, transfer, and alignment are performed using a manipulator, independently controlled positioners, and the focused ion beam. Gripping of specimens is achieved using electron-beam assisted Pt-organic deposition. Local strain measurements are obtained using digital image correlation of electron images taken during testing. Examples showing results for tensile testing of single-crystalline metallic nanowires and compression of nanoporous Au pillars will be presented in the context of size effects on mechanical behavior and highlight some of the challenges of conducting nanomechanical testing in vacuum environments.

  2. In situ nanomechanical testing in focused ion beam and scanning electron microscopes.

    Science.gov (United States)

    Gianola, D S; Sedlmayr, A; Mönig, R; Volkert, C A; Major, R C; Cyrankowski, E; Asif, S A S; Warren, O L; Kraft, O

    2011-06-01

    The recent interest in size-dependent deformation of micro- and nanoscale materials has paralleled both technological miniaturization and advancements in imaging and small-scale mechanical testing methods. Here we describe a quantitative in situ nanomechanical testing approach adapted to a dual-beam focused ion beam and scanning electron microscope. A transducer based on a three-plate capacitor system is used for high-fidelity force and displacement measurements. Specimen manipulation, transfer, and alignment are performed using a manipulator, independently controlled positioners, and the focused ion beam. Gripping of specimens is achieved using electron-beam assisted Pt-organic deposition. Local strain measurements are obtained using digital image correlation of electron images taken during testing. Examples showing results for tensile testing of single-crystalline metallic nanowires and compression of nanoporous Au pillars will be presented in the context of size effects on mechanical behavior and highlight some of the challenges of conducting nanomechanical testing in vacuum environments.

  3. Examination of mycological samples by means of the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    M. Thibaut

    1973-04-01

    Full Text Available Three species of Siphomycetes: Rhizopus arhizus, Rhizopus equinus and Rhizopus nigricans, as well as a Septomycete: Emericella nidulans, have been examined by means of a scanning electron microscope. Among the difjerent Rhizopus, this technique showed differences in the appearance of the sporangia. In Emericella nidulans, scanning microscopy enábled one to ascertain that the "Hull cells" were completely hollow and also demonstrated the ornemented aspect of the ascospores.Três espécies de Sifomicetas: Rhizopus arhizus, Rhizopus equinus, Rhizopus nigricans e um Septomiceta: Emericella nidulans foram examinados em microscopia de exploração. Esta técnica mostrou detalhes não evidenciáveis ao poder de resolução do microscópio óptico, demonstrando ser útil para o diagnóstico em micologia.

  4. Large-scale Scanning Transmission Electron Microscopy (Nanotomy) of Healthy and Injured Zebrafish Brain.

    Science.gov (United States)

    Kuipers, Jeroen; Kalicharan, Ruby D; Wolters, Anouk H G; van Ham, Tjakko J; Giepmans, Ben N G

    2016-01-01

    Large-scale 2D electron microscopy (EM), or nanotomy, is the tissue-wide application of nanoscale resolution electron microscopy. Others and we previously applied large scale EM to human skin pancreatic islets, tissue culture and whole zebrafish larvae(1-7). Here we describe a universally applicable method for tissue-scale scanning EM for unbiased detection of sub-cellular and molecular features. Nanotomy was applied to investigate the healthy and a neurodegenerative zebrafish brain. Our method is based on standardized EM sample preparation protocols: Fixation with glutaraldehyde and osmium, followed by epoxy-resin embedding, ultrathin sectioning and mounting of ultrathin-sections on one-hole grids, followed by post staining with uranyl and lead. Large-scale 2D EM mosaic images are acquired using a scanning EM connected to an external large area scan generator using scanning transmission EM (STEM). Large scale EM images are typically ~ 5 - 50 G pixels in size, and best viewed using zoomable HTML files, which can be opened in any web browser, similar to online geographical HTML maps. This method can be applied to (human) tissue, cross sections of whole animals as well as tissue culture(1-5). Here, zebrafish brains were analyzed in a non-invasive neuronal ablation model. We visualize within a single dataset tissue, cellular and subcellular changes which can be quantified in various cell types including neurons and microglia, the brain's macrophages. In addition, nanotomy facilitates the correlation of EM with light microscopy (CLEM)(8) on the same tissue, as large surface areas previously imaged using fluorescent microscopy, can subsequently be subjected to large area EM, resulting in the nano-anatomy (nanotomy) of tissues. In all, nanotomy allows unbiased detection of features at EM level in a tissue-wide quantifiable manner. PMID:27285162

  5. Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Chikara, E-mail: ti-sato@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Manaka, Sachie [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan); Nakane, Daisuke [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Nishiyama, Hidetoshi; Suga, Mitsuo [Advanced Technology Division, JEOL Ltd., Akishima, Tokyo 196-8558 (Japan); Nishizaka, Takayuki [Department of Physics, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588 (Japan); Miyata, Makoto [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Maruyama, Yuusuke [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566 (Japan)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. Black-Right-Pointing-Pointer Characteristic protein localizations were visualized using immuno-labeling. Black-Right-Pointing-Pointer M. mobile attached to sialic acid on the SiN film surface within minutes. Black-Right-Pointing-Pointer Cells were observed at low concentrations. Black-Right-Pointing-Pointer ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2-3 {mu}m-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

  6. Rapid imaging of mycoplasma in solution using Atmospheric Scanning Electron Microscopy (ASEM)

    International Nuclear Information System (INIS)

    Highlights: ► Mycoplasma mobile was observed in buffer with the Atmospheric Scanning Electron Microscope. ► Characteristic protein localizations were visualized using immuno-labeling. ► M. mobile attached to sialic acid on the SiN film surface within minutes. ► Cells were observed at low concentrations. ► ASEM should promote study and early-stage diagnosis of mycoplasma. -- Abstract: Mycoplasma is a genus of bacterial pathogen that causes disease in vertebrates. In humans, the species Mycoplasma pneumoniae causes 15% or more of community-acquired pneumonia. Because this bacterium is tiny, corresponding in size to a large virus, diagnosis using optical microscopy is not easy. In current methods, chest X-rays are usually the first action, followed by serology, PCR amplification, and/or culture, but all of these are particularly difficult at an early stage of the disease. Using Mycoplasma mobile as a model species, we directly observed mycoplasma in buffer with the newly developed Atmospheric Scanning Electron Microscope (ASEM). This microscope features an open sample dish with a pressure-resistant thin film window in its base, through which the SEM beam scans samples in solution, from below. Because of its 2–3 μm-deep scanning capability, it can observe the whole internal structure of mycoplasma cells stained with metal solutions. Characteristic protein localizations were visualized using immuno-labeling. Cells were observed at low concentrations, because suspended cells concentrate in the observable zone by attaching to sialic acid on the silicon nitride (SiN) film surface within minutes. These results suggest the applicability of the ASEM for the study of mycoplasmas as well as for early-stage mycoplasma infection diagnosis.

  7. Subsurface Examination of a Foliar Biofilm Using Scanning Electron- and Focused-Ion-Beam Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Patricia K.; Arey, Bruce W.; Mahaffee, Walt F.

    2011-08-01

    The dual beam scanning electron microscope, equipped with both a focused ion- and scanning electron- beam (FIB SEM) is a novel tool for the exploration of the subsurface structure of biological tissues. The FIB can remove a predetermined amount of material from a selected site to allow for subsurface exploration and when coupled with SEM or scanning ion- beam microscopy (SIM) could be suitable to examine the subsurface structure of bacterial biofilms on the leaf surface. The suitability of chemical and cryofixation was examined for use with the FIB SEM to examine bacterial biofilms on leaf surfaces. The biological control agent, Burkholderia pyroccinia FP62, that rapidly colonizes the leaf surface and forms biofilms, was inoculated onto geranium leaves and incubated in a greenhouse for 7 or 14 days. Cryofixation was not suitable for examination of leaf biofilms because it created a frozen layer over the leaf surface that cracked when exposed to the electron beam and the protective cap required for FIB milling could not be accurately deposited. With chemically fixed samples, it was possible to precisely FIB mill a single cross section (5 µm) or sequential cross sections from a single site without any damage to the surrounding surface. Biofilms, 7 days post-inoculation (DPI), were composed of 2 to 5 bacterial cell layers while biofilms 14 DPI ranged from 5 to greater than 30 cell layers. Empty spaces between bacteria cells in the subsurface structure were observed in biofilms 7- and 14-DPI. Sequential cross sections inferred that the empty spaces were often continuous between FP62 cells and could possibly make up a network of channels throughout the biofilm. FIB SEM was a useful tool to observe the subsurface composition of a foliar biofilm.

  8. Use of fluorescence and scanning electron microscopy as tools in teaching biology

    Science.gov (United States)

    Ghosh, Nabarun; Silva, Jessica; Vazquez, Aracely; Das, A. B.; Smith, Don W.

    2011-06-01

    Recent nationwide surveys reveal significant decline in students' interest in Math and Sciences. The objective of this project was to inspire young minds in using various techniques involved in Sciences including Scanning Electron Microscopy. We used Scanning Electron Microscope in demonstrating various types of Biological samples. An SEM Tabletop model in the past decade has revolutionized the use of Scanning Electron Microscopes. Using SEM Tabletop model TM 1000 we studied biological specimens of fungal spores, pollen grains, diatoms, plant fibers, dust mites, insect parts and leaf surfaces. We also used fluorescence microscopy to view, to record and analyze various specimens with an Olympus BX40 microscope equipped with FITC and TRITC fluorescent filters, a mercury lamp source, DP-70 digital camera with Image Pro 6.0 software. Micrographs were captured using bright field microscopy, the fluoresceinisothiocyanate (FITC) filter, and the tetramethylrhodamine (TRITC) filter settings at 40X. A high pressure mercury lamp or UV source was used to excite the storage molecules or proteins which exhibited autofluorescence. We used fluorescent microscopy to confirm the localization of sugar beet viruses in plant organs by viewing the vascular bundles in the thin sections of the leaves and other tissues. We worked with the REU summer students on sample preparation and observation on various samples utilizing the SEM. Critical Point Drying (CPD) and metal coating with the sputter coater was followed before observing some cultured specimen and the samples that were soft in textures with high water content. SEM Top allowed investigating the detailed morphological features that can be used for classroom teaching. Undergraduate and graduate researchers studied biological samples of Arthropods, pollen grains and teeth collected from four species of snakes using SEM. This project inspired the research students to pursue their career in higher studies in science and 45% of the

  9. Scanning electron microscopy study of protein immobilized on SIO2 Sol-gel surfaces

    Directory of Open Access Journals (Sweden)

    Assis O.B.G.

    2003-01-01

    Full Text Available Uniform attachment of enzymes to solid surfaces is essential in the development of bio and optical sensor devices. Immobilization by adsorption according to hydrophilic or hydrophobic nature is dependent on the charges and defects of the support surfaces. Sol-gel SiO2 densified glass surfaces, frequently used as supports for protein immobilization, are evaluated via scanning electron microscopy. The model protein is globular enzyme lysozyme, deposited by adsorption on functionalized surfaces. Formation of a protein layer is confirmed by FTIR spectroscopy, and the SEM images suggest discontinuous adsorption in areas where cracks predominate on the glass surface.

  10. A scanning electron microscopic study of impala (Aepyceros melampus sperm from the Kruger National Park

    Directory of Open Access Journals (Sweden)

    D.J. Ackerman

    1996-02-01

    Full Text Available Since knowledge of sperm morphological characteristics can play an important role in semen evaluation and fertilisation, baseline data on sperm ultrastructure are required. Live spermatozoa were collected from the cauda epididymis from 64 impala rams in the Kruger National Park and 5082 spermatozoa from 40 of these impala were studied by scanning electron microscopy. The mean length of impala sperm was 59.23 @ 2.7 um. The morphology of normal sperm as well as the occurrence of abnormalities were documented. The morphology of impala sperm were compared with those of other mammals. New findings on appendages of the cytoplasmic droplet are described and interpreted.

  11. Scanning electron microscopic analyses of Ferrocyanide tank wastes for the Ferrocyanide safety program

    Energy Technology Data Exchange (ETDEWEB)

    Callaway, W.S.

    1995-09-01

    This is Fiscal Year 1995 Annual Report on the progress of activities relating to the application of scanning electron microscopy in addressing the Ferrocyanide Safety Issue associated with Hanford Site high-level radioactive waste tanks. The status of the FY 1995 activities directed towards establishing facilities capable of providing SEM based micro-characterization of ferrocyanide tank wastes is described. A summary of key events in the SEM task over FY 1995 and target activities in FY 1996 are presented. A brief overview of the potential applications of computer controlled SEM analytical data in light of analyses of ferrocyanide simulants performed by an independent contractor is also presented

  12. Scanning electron microscopic analyses of Ferrocyanide tank wastes for the Ferrocyanide safety program

    International Nuclear Information System (INIS)

    This is Fiscal Year 1995 Annual Report on the progress of activities relating to the application of scanning electron microscopy in addressing the Ferrocyanide Safety Issue associated with Hanford Site high-level radioactive waste tanks. The status of the FY 1995 activities directed towards establishing facilities capable of providing SEM based micro-characterization of ferrocyanide tank wastes is described. A summary of key events in the SEM task over FY 1995 and target activities in FY 1996 are presented. A brief overview of the potential applications of computer controlled SEM analytical data in light of analyses of ferrocyanide simulants performed by an independent contractor is also presented

  13. Reaction of LiD with water vapor: thermogravimetric and scanning electron microscopy studies

    Energy Technology Data Exchange (ETDEWEB)

    Balooch, M; Dinh, L N; LeMay, J D

    2000-09-14

    The kinetics of hydroxide film growth on LiD have been studied by the thermogravimetric method in nitrogen saturated with water vapor and by scanning electron microscopy (SEM) of samples that have been exposed to air with 50% relative humidity. The reaction probability is estimated to be 4 x 10{sup -7} for LiD exposed to ambient air with 50% relative humidity, suggesting that the diffusion through the hydroxide film is not the limiting step on the overall process at high moisture levels. The rate of growth is drastically reduced when the temperature is increased to 60 C.

  14. Scanning electron microscopy and X-ray spectroscopy applied to mycelial phase of sporothrix schenckii

    Directory of Open Access Journals (Sweden)

    M. Thibaut

    1975-04-01

    Full Text Available Scanning electron microscopy applied to the mycelial phase of Sporothrix schenckii shows a matted mycelium with conidia of a regular pattern. X-Ray microanalysis applied in energy dispersive spectroscopy and also in wavelength dispersive spectroscopy reveals the presence of several elements of Mendeleef's classification.Sporothrix schenckii foi estudado em microscopia eletrônica. Foram observados caracteres das hífas e dos esporos, vários elementos da classificação periódica foram postos em evidência graças à micro-análise a raios X.

  15. Scanning tunneling spectroscopy on ZnO(0001) surfaces : evidence for an inhomogeneous electronic structure

    Science.gov (United States)

    Hackens, B.; Rodrigues, M. S.; Faniel, S.; Mouthuy, P. O.; Melinte, S.; Dumont, J.; Sporken, R.

    2010-03-01

    We performed low temperature (77 K) scanning tunneling microscopy (STM) and spectroscopy (STS) on the polar Zn-terminated ZnO(0001) surface [1]. STM and STS data show that the surface electronic structure strongly depends on the local morphology : we observe a narrow bandgap and surface states in the flat regions, and, in the defective surface regions, a wide bandgap without surface states. We also image atomically-resolved (√3 x√3)R30^o reconstructions in small defect-free areas.[4pt] [1] J. Dumont et al., Appl. Phys. Lett. 95, 132102 (2009).

  16. A Low-Temperature Scanning Electron Microscopy Study of Ice Cream. I Techniques and General Microstructure

    OpenAIRE

    Caldwell, K. B.; Goff, H. D.; Stanley, D W

    1992-01-01

    The objective of this study was to investigate techniques suitable for viewing the microstructure of ice cream in the frozen and fully hydrated state using low temperature scanning electron microscopy (L T-SEM), and to examine the microstructure of the frozen product. lee cream bad four distinct structural phases: ice crystals, air bubbles, fat globules and serum. Air bubbles, 10 to 60 ~-tm in diameter, were lined with fat globules, 0.5 to 2.5 J.tnl in diameter. Ice cry stals with a mean di a...

  17. 3D scanning electron microscopy applied to surface characterization of fluorosed dental enamel.

    Science.gov (United States)

    Limandri, Silvina; Galván Josa, Víctor; Valentinuzzi, María Cecilia; Chena, María Emilia; Castellano, Gustavo

    2016-05-01

    The enamel surfaces of fluorotic teeth were studied by scanning electron stereomicroscopy. Different whitening treatments were applied to 25 pieces to remove stains caused by fluorosis and their surfaces were characterized by stereomicroscopy in order to obtain functional and amplitude parameters. The topographic features resulting for each treatment were determined through these parameters. The results obtained show that the 3D reconstruction achieved from the SEM stereo pairs is a valuable potential alternative for the surface characterization of this kind of samples. PMID:26930005

  18. Installation of a Scanning Electron Microscope in the Hot Cell Laboratory of NRG Petten

    International Nuclear Information System (INIS)

    In 2010 a new scanning electron microscope (SEM), equipped with several detectors (EDS, WDS and EBSD) is installed in a new hot cell. The SEM is modified for use in a radioactive environment. Therefore the irradiation sensitive parts are removed or protected. In addition changes have been made to the SEM to allow remote handling and to allow maintenance of the important parts. This paper describes the new facility at the NRG Hot Cell Laboratories and gives some examples of the first microscopy results. (author)

  19. Scanning electron microscopic study of glass container degradation in infusion solution

    International Nuclear Information System (INIS)

    Solid particles found in an infusion solution under development were examined by scanning electron microscopy combined with X-ray fluorescent elemental analysis. The main fraction of the particles was found to be flakes of corroded glass. The elemental composition of the glass shred surface has proved that the particles originate from the glass matrix, despite the slightly acidic pH of the solution contained. Based on the results, the use of this glass-type as container for this infusion has been rejected

  20. Environmental scanning electron microscope (ESEM) evaluation of crystal and plaque formation associated with biocorrosion.

    Science.gov (United States)

    Geiger, S L; Ross, T J; Barton, L L

    1993-08-01

    The biofilm attributed to Desulfovibrio vulgaris growing in the presence of ferrous metals was examined with an environmental scanning electron microscope. This novel microscope produced images of iron sulfide colloids and other iron containing structures that had not been reported previously. A plaque composed of iron sulfide enveloped the surface of the corroding metal while crystals containing magnesium, iron, sulfur, and phosphorus were present in the culture where corrosion was in progress. A structure resembling the tubercule found in aerobic corrosion was observed on stainless steel undergoing biocorrosion and the elements present in this structure included sulfur, iron, chloride, calcium, potassium, and chromium.

  1. Verifying Data Integrity of Electronically Scanned Pressure Systems at the NASA Glenn Research Center

    Science.gov (United States)

    Panek, Joseph W.

    2001-01-01

    The proper operation of the Electronically Scanned Pressure (ESP) System critical to accomplish the following goals: acquisition of highly accurate pressure data for the development of aerospace and commercial aviation systems and continuous confirmation of data quality to avoid costly, unplanned, repeat wind tunnel or turbine testing. Standard automated setup and checkout routines are necessary to accomplish these goals. Data verification and integrity checks occur at three distinct stages, pretest pressure tubing and system checkouts, daily system validation and in-test confirmation of critical system parameters. This paper will give an overview of the existing hardware, software and methods used to validate data integrity.

  2. Morphological studies of Gross virus-induced lymphoblasts by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Ichikawa,Hiroyuki

    1977-04-01

    Full Text Available The surface of Gross virus-induced murine lymphoblasts and C-type virus particles budding from these cells were investigated under the scanning electron microscope (SEM. The cells appeared spindle-shaped or roughly-rounded with extensive surface features consisting of microvilli, blebs and ruffled membranes. C-type virus particles were detected on the cell membrane as small spherical particles, distinguishable from the microvilli. Clustered virions were observed in some cases. However, the distribution of virions appeared to be random. The surface of the virion was smooth and had no globular units at high magnification. These morphological observations were confirmed in ultrathin sections.

  3. High-resolution imaging by scanning electron microscopy of semithin sections in correlation with light microscopy.

    Science.gov (United States)

    Koga, Daisuke; Kusumi, Satoshi; Shodo, Ryusuke; Dan, Yukari; Ushiki, Tatsuo

    2015-12-01

    In this study, we introduce scanning electron microscopy (SEM) of semithin resin sections. In this technique, semithin sections were adhered on glass slides, stained with both uranyl acetate and lead citrate, and observed with a backscattered electron detector at a low accelerating voltage. As the specimens are stained in the same manner as conventional transmission electron microscopy (TEM), the contrast of SEM images of semithin sections was similar to TEM images of ultrathin sections. Using this technique, wide areas of semithin sections were also observed by SEM, without the obstruction of grids, which was inevitable for traditional TEM. This study also applied semithin section SEM to correlative light and electron microscopy. Correlative immunofluorescence microscopy and immune-SEM were performed in semithin sections of LR white resin-embedded specimens using a FluoroNanogold-labeled secondary antibody. Because LR white resin is hydrophilic and electron stable, this resin is suitable for immunostaining and SEM observation. Using correlative microscopy, the precise localization of the primary antibody was demonstrated by fluorescence microscopy and SEM. This method has great potential for studies examining the precise localization of molecules, including Golgi- and ER-associated proteins, in correlation with LM and SEM.

  4. Atomic-Scale Study Of Complex Cobalt Oxide Using Scanning Transmission Electron Microscope

    Science.gov (United States)

    Gulec, Ahmet

    Cobalt oxides offer a rich ?eld for the formation of novel phases, including superconductors and exotic magnetic phases, involving a mixed valence state for cobalt and/or the presence of oxygen vacancies. Having spin states, such as, low spin (LS), high spin (HS), and intermediate spin (IS), cobalt oxides differ from other 3d metal oxides The presence of such spin states make the physics of the cobalt oxides so complicated that it has not yet been completely understood. In order to improve our understanding of the various phase transitions observed in Cobalt oxides and to comprehend the relationship between crystal and electronic structure, both high energy resolution and high spatial resolution are essential. Fortunately, transmission electron microscopy (TEM) is a technique which is capable of ful?lling both of these requirements. In this thesis, I have utilized unique techniques in a scanning transmission electron microscope (STEM) to analyze the atomic-scale structure-property relationship, both at room temperature and through insitu cooling to liquid nitrogen (LN2) temperature. In particular, by using correlated Z-contrast imaging, electron energy loss spectrum (EELS) and electron energy loss magnetic circular dichroism (EMCD), the structure, composition, bonding and magnetic behavior are characterized directly on the atomic scale.

  5. Noise characteristics of the gas ionization cascade used in low vacuum scanning electron microscopy

    International Nuclear Information System (INIS)

    The noise characteristics of gas cascade amplified electron signals in low vacuum scanning electron microscopy (LVSEM) are described and analyzed. We derive expressions for each component contributing to the total noise culminating in a predictive, quantitative model that can be used for optimization of LVSEM operating parameters. Signal and noise behavior is characterized experimentally and used to validate the model. Under most operating conditions, the noise is dominated by the excess noise generated in the gas amplification cascade. At high gains, the excess noise increases proportionally with gain such that the signal-to-noise ratio is constant. The effects of several instrument operating parameters, including working distance, gas pressure, beam current, and detector bias, are condensed and presented in the form of a master curve.

  6. Silver methenamine staining for scanning electron microscopy of bone sections containing biomaterials.

    Science.gov (United States)

    Frayssinet, P; Hanker, J S; Rouquet, N; Primout, I; Giammara, B

    1999-01-01

    Sections of tissue containing orthopedic materials are currently used to study the compatibility of those materials and to perform electron probe microanalysis at the material-tissue interface. Identification of the cells in contact with the material by Scanning electron microscopy (SEM) is of interest. We have developed a method for staining cells and tissue structures embedded in polymethyl methacrylate with silver methenamine once the sections have been obtained. Sections were prepared by grinding, and the silver methenamine was applied after oxidation with periodic acid. The procedure was carried out in a microwave oven. Backscatter SEM showed staining of the cell nucleus membrane, chromatin, the nuclear organizers, and the chromosomes of dividing cells. The cytoplasm and the cytoplasmic membrane were also stained. Collagen fibers of the extracellular matrix and the mineralized matrix of bone were labeled. Material particles in the macrophages were easily recognizable and Energy-Dispersive Spectrometer were not impaired by the presence of silver in the preparation. PMID:10190255

  7. Biological application of Compressed Sensing Tomography in the Scanning Electron Microscope

    Science.gov (United States)

    Ferroni, Matteo; Signoroni, Alberto; Sanzogni, Andrea; Masini, Luca; Migliori, Andrea; Ortolani, Luca; Pezza, Alessandro; Morandi, Vittorio

    2016-01-01

    The three-dimensional tomographic reconstruction of a biological sample, namely collagen fibrils in human dermal tissue, was obtained from a set of projection-images acquired in the Scanning Electron Microscope. A tailored strategy for the transmission imaging mode was implemented in the microscope and proved effective in acquiring the projections needed for the tomographic reconstruction. Suitable projection alignment and Compressed Sensing formulation were used to overcome the limitations arising from the experimental acquisition strategy and to improve the reconstruction of the sample. The undetermined problem of structure reconstruction from a set of projections, limited in number and angular range, was indeed supported by exploiting the sparsity of the object projected in the electron microscopy images. In particular, the proposed system was able to preserve the reconstruction accuracy even in presence of a significant reduction of experimental projections. PMID:27646194

  8. Thermal Evolution of Organic Matter in Source Rocks—Experimental and Scanning Electron Microscopic Studies

    Institute of Scientific and Technical Information of China (English)

    姜开侠; 潘小明

    1991-01-01

    Five major froms(lamellar,banded,crack-like,dissceminated and segregated encrustation(of organic matter distribution in sourc rocks have been revealed under scanning electron microscope by using the heavy metal staining technique.The degree of organic impregnation is related to the amount of liquied hydrocarbons in the rocks,and from this relationship a rough estimation of organic matter can be made on the basis of electron microscopic observations.In conjunction with experimental studies it has been found that the distribution forms of organic matter are a function of its maturity in the process of thermal evolution and accordingly some microscopic criteria can be developed for the assessment of source rocks.

  9. Formation of Three-Way Scanning Electron Microscope Moiré on Micro/Nanostructures

    Directory of Open Access Journals (Sweden)

    Qinghua Wang

    2014-01-01

    Full Text Available Three-way scanning electron microscope (SEM moiré was first generated using a designed three-way electron beam (EB in an SEM. The spot-type three-way SEM moiré comes from the interference between the three-way EB and the specimen grating in which the periodic cells are arranged in a triangular manner. The deformation and the structure information of the specimen grating in three directions can be simultaneously obtained from the three-way SEM moiré. The design considerations of the three-way EB were discussed. As an illustration, the three-way SEM moiré spots produced on a silicon slide were presented. The proposed three-way SEM moiré method is expected to characterize micro/nanostructures in triangular or hexagonal arrangements in three directions at the same time.

  10. Biological application of Compressed Sensing Tomography in the Scanning Electron Microscope.

    Science.gov (United States)

    Ferroni, Matteo; Signoroni, Alberto; Sanzogni, Andrea; Masini, Luca; Migliori, Andrea; Ortolani, Luca; Pezza, Alessandro; Morandi, Vittorio

    2016-01-01

    The three-dimensional tomographic reconstruction of a biological sample, namely collagen fibrils in human dermal tissue, was obtained from a set of projection-images acquired in the Scanning Electron Microscope. A tailored strategy for the transmission imaging mode was implemented in the microscope and proved effective in acquiring the projections needed for the tomographic reconstruction. Suitable projection alignment and Compressed Sensing formulation were used to overcome the limitations arising from the experimental acquisition strategy and to improve the reconstruction of the sample. The undetermined problem of structure reconstruction from a set of projections, limited in number and angular range, was indeed supported by exploiting the sparsity of the object projected in the electron microscopy images. In particular, the proposed system was able to preserve the reconstruction accuracy even in presence of a significant reduction of experimental projections. PMID:27646194

  11. Specimen-thickness effects on transmission Kikuchi patterns in the scanning electron microscope.

    Science.gov (United States)

    Rice, K P; Keller, R R; Stoykovich, M P

    2014-06-01

    We report the effects of varying specimen thickness on the generation of transmission Kikuchi patterns in the scanning electron microscope. Diffraction patterns sufficient for automated indexing were observed from films spanning nearly three orders of magnitude in thickness in several materials, from 5 nm of hafnium dioxide to 3 μm of aluminum, corresponding to a mass-thickness range of ~5 to 810 μg cm(-2) . The scattering events that are most likely to be detected in transmission are shown to be very near the exit surface of the films. The energies, spatial distribution and trajectories of the electrons that are transmitted through the film and are collected by the detector are predicted using Monte Carlo simulations.

  12. Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology

    International Nuclear Information System (INIS)

    Scanning electron microscopy is frequently applied to dermatological problems, as is evident from a review of the recent literature. In this paper, preparation methods and new techniques allowing experimental studies on the integumentary system are emphasized. Quantitative analysis in the electron microscope by use of energy-dispersive X-ray microanalysis (EDX) has become an important accessory technique. EDX can, for instance, be used to study problems involving physiological changes induced in skin by agents causing contact reactions. Recently, it has been shown that treatment with DNCB, chromate and nickel causes changes in elemental distribution in guinea-pig skin. In addition, elemental uptake in the integumentary system and in pathological inclusions in skin can be analyzed

  13. Scanning tunneling microscopy characterization of the geometric and electronic structure of hydrogen-terminated silicon surfaces

    Science.gov (United States)

    Kaiser, W. J.; Bell, L. D.; Hecht, M. H.; Grunthaner, F. J.

    1988-01-01

    Scanning tunneling microscopy (STM) methods are used to characterize hydrogen-terminated Si surfaces prepared by a novel method. The surface preparation method is used to expose the Si-SiO2 interface. STM images directly reveal the topographic structure of the Si-SiO2 interface. The dependence of interface topography on oxide preparation conditions observed by STM is compared to the results of conventional surface characterization methods. Also, the electronic structure of the hydrogen-terminated surface is studied by STM spectroscopy. The near-ideal electronic structure of this surface enables direct tunnel spectroscopy measurements of Schottky barrier phenomena. In addition, this method enables probing of semiconductor subsurface properties by STM.

  14. On possibility of high frequency electron beam scanning with application of focusing system for x-ray generation

    International Nuclear Information System (INIS)

    The article describes the electron beam scanning system in combination with electromagnetic focusing system. These systems find their application in different vacuum tube devices that provide the generation of X-ray radiation. Similar systems can be utilized in such fields as medicine, industry and defectoscopy. Electron tube system can be based on thermal or field emission cathodes. Scanning system is built up on two pair of electrical deflecting dipoles. The scanning can also be based on magnetic deflecting system. Beam focusing is achieved by the geometrical fea-tures of electrodes structure and electron lenses. Magnetic focusing can also be used for transversal focusing of the beam. The article describes the schemes of the unit with electron beam scanning and different methods of realization. Beam dynamics investigation in electromagnetic fields of the unit is considered

  15. The ultrastructure of pollen grain surface in allotetraploid petunia (Petunia hybrida hort. superbissima as revealed by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    S. Muszyński

    2015-05-01

    Full Text Available The ultrastructure of pollen grain surface in allotetraploid petunias was analyzed by scanning electron microscopy. The pollen grain wall is developed into characteristic pattern of convulations.

  16. Correlation between obstructive coronary artery disease and electron beam tomography coronary artery calcium scan

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Hong, Yong Kook; Park, Sung Il; Lee, Hyang Mee; Choe, Kyu Ok [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-08-01

    To determine the correlation between obstructive coronary artery disease and electron beam tomography coronary artery calcium(EBT CAC) scan and to measure the difference in calcium score according to symptoms. Materials and Methods : Fifty-six patients underwent EBT CAC scanning and either coronary angiography or stress thallium 201 scanning or the treadmill test. When the results were positive, coronary artery obstructive disease(CAOD) was assumed to be present. The patients were divided into three groups : symptomatic CAOD,asymptomatic CAOD, and asymptomatic non- CAOD; those with a previous history of myocardial ischemia or who showed positive results in any of the three tests relating to typical symptoms of angina were assigned to the symptomatic group. Results : The number of cases assigned to group to group 1,2 and 3 was 19, 16 and 21, respectively; total CAC scores were 571 {+-} 751, 600 {+-} 726 293{+-} 401, respectively. The difference in CAC score between asymptomatic CAOD and asymptomatic non- CAOD was not statistically significant(p=0.079) but in asymptomatic CAOD, the score tended to be higher. The CAC score was not different between symptomatic and asymptomatic CAOD(p>0.1). When the CAC threshold was 1, sensitivity was 89% and specificity was 14%;when the threshold was 200, sensitivity was 60% and specificity was 67%. Conclusion : When the EBT CAC score is high, further evaluation provides early evidence of coronary artery obstructive disease.

  17. Evaluation of environmental scanning electron microscopy for analysis of Proteus mirabilis crystalline biofilms in situ on urinary catheters

    OpenAIRE

    Holling, Nina; Dedi, Cinzia; Jones, Caroline E; Hawthorne, Joseph A; Hanlon, Geoffrey W; Salvage, Jonathan P.; Patel, Bhavik A.; Barnes, Lara M; Jones, Brian V.

    2014-01-01

    Proteus mirabilis is a common cause of catheter-associated urinary tract infections and frequently leads to blockage of catheters due to crystalline biofilm formation. Scanning electron microscopy (SEM) has proven to be a valuable tool in the study of these unusual biofilms, but entails laborious sample preparation that can introduce artefacts, undermining the investigation of biofilm development. In contrast, environmental scanning electron microscopy (ESEM) permits imaging of unprocessed, f...

  18. Environmental scanning electron microscopic study of macrophages associated with the tunica vasculosa lentis in the developing rat eye

    OpenAIRE

    Djano, J; Griffin, B; van Bruggen, I; McMenamin, P

    1999-01-01

    AIMS—To demonstrate the value of environmental scanning electron microscopy (ESEM) when used in combination with immunogold/silver enhancement methods as a valuable tool in ocular research, and to determine the phenotype of macrophages associated with the tunica vasculosa lentis while maintaining a topographical view of the lens surface.
METHODS—Prenatal and postnatal rat eyes were investigated by conventional scanning electron microscopy and ESEM. In the latter case tissues were prestained w...

  19. Visualisation of natural aquatic colloids and particles - A comparison of conventional high vacuum and environmental scanning electron microscopy

    OpenAIRE

    Doucet, F. J.; Lead, J. R.; Maguire, L.; Achterberg, Eric P.; Millward, G. E.

    2005-01-01

    The applicability of environmental scanning electron microscopy (ESEM; imaging of hydrated samples) and conventional high vacuum scanning electron microscopy (SEM; imaging of dried samples at high vacuum) for the observation of natural aquatic colloids and particles was explored and compared. Specific attention was given to the advantages and limitations of these two techniques when used to assess the sizes and morphologies of complex and heterogeneous environmental systems. The observation o...

  20. Analysis of acute impact of oleoresin capsicum on rat nasal mucosa using scanning electron microscopy.

    Science.gov (United States)

    Catli, Tolgahan; Acar, Mustafa; Olgun, Yüksel; Dağ, İlknur; Cengiz, Betül Peker; Cingi, Cemal

    2015-01-01

    Analysis of acute cellular changes seen in nasal mucosa of Wistar-Albino rats exposed to different doses of oleoresin capsicum for various time periods by means of scanning electron microscopy. Thirty-five Wistar-Albino rats were divided into five groups of seven rats each. 6-gram oleoresin capsicum per second was sprayed into cages of the groups except group 1. Spray times and duration of exposure to pepper gasses were different for each group. Thirty minutes after the exposure, the animals were killed and specimens from their nasal mucosas were harvested and examined under scanning electron microscope. Mucosal damage was scored from 0-4 points. Mean values of nasal mucosa damage scores of the groups were calculated and compared statistically. Average damage scores of the groups exposed to identical doses of oleoresin capsicum for various exposure times were compared and a statistically significant difference was seen between Groups 2 and 3 (p 0.05). Average damage scores of the groups exposed to various doses for identical exposure times were compared, and statistically significant differences were observed between Groups 2 and 4 and also Groups 3 and 5 (p pepper gas exerts destructive changes on rat nasal mucosa. The extent of these destructive changes increases with the prolonged exposure to higher doses. Besides, exposure time also stands out as an influential factor on the extent of the destructive changes. PMID:24627077

  1. New Aspidoderidae species parasite of Didelphis aurita (Mammalia: Didelphidae): a light and scanning electron microscopy approach.

    Science.gov (United States)

    Chagas-Moutinho, V A; Sant'anna, V; Oliveira-Menezes, A; De Souza, W

    2014-02-01

    Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Skrjabin and Schikobalova, 1947, are widely distributed in the Americas. The family Aspidoderidae includes the subfamilies Aspidoderinae Skrjabin and Schikobalova, 1947, and Lauroiinae Skrjabin and Schikobalova, 1951. These two subfamilies are delineated by the presence or absence of cephalic cordons at the anterior region. The nematodes in the subfamily Aspidoderinae, which includes the genus AspidoderaRailliet and Henry, 1912, are represented by nematodes with anterior cephalic cordons at the anterior end. The nematodes of the genus AspidoderaRailliet and Henry, 1912, are found in the cecum and large intestine of mammals of the orders Edentata, Marsupialia and Rodentia. Species within this genus have many morphological similarities. The use of scanning electron microscopy allows the specific characterization of the species within this genus. In the present work, we describe a new species of Aspidodera parasite of the large intestine of Didelphis aurita (Mammalia: Didelphidae) Wied-Neuwied, 1826, collected from Cachoeiras de Macacu, Rio de Janeiro. The combination of light and scanning electron microscopy allowed us a detailed analysis of this nematode. PMID:24129095

  2. Microcomputer-Assisted Biomass Determination of Plankton Bacteria on Scanning Electron Micrographs

    Science.gov (United States)

    Krambeck, Christiane; Krambeck, Hans-Jürgen; Overbeck, Jürgen

    1981-01-01

    Although biovolume is a better measure of biomass than is cell number, biovolumes have rarely been measured because their evaluation is extremely time-consuming. We developed a microcomputer system that assists cell size measurements on images of filtered plankton: scanning electron micrograph negatives were projected on a digitizer field, bacterial length and width were marked by a cursor, and coordinates were directly transferred to an MOS 6502 microcomputer (KIM 1). The dialogue program BABI organized and controlled the digitizer measurements in cooperation with the user, enabled corrections, and printed out results with 95% confidence limits and sample description. The time for scanning electron micrograph preparation was reduced to 15 min (quick transfer to Freon 113 during filtration and air drying). Altogether, this biovolume determination took about 2.5 h for confidence limits of ±15%. Examples are given for applications of the method: (i) comparison of 10 lakes (with specific activities for glucose uptake and for heterotrophic CO2 fixation); (ii) ranges of biomass parameters in one lake; (iii) diurnal cycles (with synchronizing effects, uptake of algal exudates, and calculation of daily growth). This method is discussed in relation to other biomass methods (epifluorescent microscopy, lipopolysaccharide technique, frequency of dividing cells) and the problem of biovolume-to-carbon conversions. Images PMID:16345807

  3. New insights into subsurface imaging of carbon nanotubes in polymer composites via scanning electron microscopy

    Science.gov (United States)

    Zhao, Minhua; Ming, Bin; Kim, Jae-Woo; Gibbons, Luke J.; Gu, Xiaohong; Nguyen, Tinh; Park, Cheol; Lillehei, Peter T.; Villarrubia, J. S.; Vladár, András E.; Liddle, J. Alexander

    2015-02-01

    Despite many studies of subsurface imaging of carbon nanotube (CNT)-polymer composites via scanning electron microscopy (SEM), significant controversy exists concerning the imaging depth and contrast mechanisms. We studied CNT-polyimide composites and, by three-dimensional reconstructions of captured stereo-pair images, determined that the maximum SEM imaging depth was typically hundreds of nanometers. The contrast mechanisms were investigated over a broad range of beam accelerating voltages from 0.3 to 30 kV, and ascribed to modulation by embedded CNTs of the effective secondary electron (SE) emission yield at the polymer surface. This modulation of the SE yield is due to non-uniform surface potential distribution resulting from current flows due to leakage and electron beam induced current. The importance of an external electric field on SEM subsurface imaging was also demonstrated. The insights gained from this study can be generally applied to SEM nondestructive subsurface imaging of conducting nanostructures embedded in dielectric matrices such as graphene-polymer composites, silicon-based single electron transistors, high resolution SEM overlay metrology or e-beam lithography, and have significant implications in nanotechnology.

  4. Is Canada ready for patient accessible electronic health records? A national scan

    Directory of Open Access Journals (Sweden)

    Eysenbach Gunther

    2008-07-01

    Full Text Available Abstract Background Access to personal health information through the electronic health record (EHR is an innovative means to enable people to be active participants in their own health care. Currently this is not an available option for consumers of health. The absence of a key technology, the EHR, is a significant obstacle to providing patient accessible electronic records. To assess the readiness for the implementation and adoption of EHRs in Canada, a national scan was conducted to determine organizational readiness and willingness for patient accessible electronic records. Methods A survey was conducted of Chief Executive Officers (CEOs of Canadian public and acute care hospitals. Results Two hundred thirteen emails were sent to CEOs of Canadian general and acute care hospitals, with a 39% response rate. Over half (54.2% of hospitals had some sort of EHR, but few had a record that was predominately electronic. Financial resources were identified as the most important barrier to providing patients access to their EHR and there was a divergence in perceptions from healthcare providers and what they thought patients would want in terms of access to the EHR, with providers being less willing to provide access and patients desire for greater access to the full record. Conclusion As the use of EHRs becomes more commonplace, organizations should explore the possibility of responding to patient needs for clinical information by providing access to their EHR. The best way to achieve this is still being debated.

  5. Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope.

    Science.gov (United States)

    Hieckmann, Ellen; Nacke, Markus; Allardt, Matthias; Bodrov, Yury; Chekhonin, Paul; Skrotzki, Werner; Weber, Jörg

    2016-01-01

    Extended defects such as dislocations and grain boundaries have a strong influence on the performance of microelectronic devices and on other applications of semiconductor materials. However, it is still under debate how the defect structure determines the band structure, and therefore, the recombination behavior of electron-hole pairs responsible for the optical and electrical properties of the extended defects. The present paper is a survey of procedures for the spatially resolved investigation of structural and of physical properties of extended defects in semiconductor materials with a scanning electron microscope (SEM). Representative examples are given for crystalline silicon. The luminescence behavior of extended defects can be investigated by cathodoluminescence (CL) measurements. They are particularly valuable because spectrally and spatially resolved information can be obtained simultaneously. For silicon, with an indirect electronic band structure, CL measurements should be carried out at low temperatures down to 5 K due to the low fraction of radiative recombination processes in comparison to non-radiative transitions at room temperature. For the study of the electrical properties of extended defects, the electron beam induced current (EBIC) technique can be applied. The EBIC image reflects the local distribution of defects due to the increased charge-carrier recombination in their vicinity. The procedure for EBIC investigations is described for measurements at room temperature and at low temperatures. Internal strain fields arising from extended defects can be determined quantitatively by cross-correlation electron backscatter diffraction (ccEBSD). This method is challenging because of the necessary preparation of the sample surface and because of the quality of the diffraction patterns which are recorded during the mapping of the sample. The spatial resolution of the three experimental techniques is compared.

  6. Signal generation in an isotropic medium in scanning electron acoustic microscope

    Institute of Scientific and Technical Information of China (English)

    QIAN Menglu; PENG Ruolong

    2008-01-01

    Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122:57-63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM (Scanning Electron Acoustic Microscopy) signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2a (a is the radius of the focused electron beam).Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.

  7. Scanning electron acoustic microscopy of residual stresses in ceramics - Theory and experiment

    Science.gov (United States)

    Cantrell, John H.; Qian, Menglu

    1992-01-01

    The paper presents a three-dimensional mathematical model of signal generation and contrast in brittle materials and uses the model to simulate the effect of residual stress fields on the scanning electron acoustic microscopy (SEAM)-generated electron acoustic signal. According to the model, a positive (tensile) strain produces an increase in the output signal, whereas a negative (compressive) strain produces a decrease in the ouput signal. Dark field contrast conditions occur at a chopping frequency at which V2 - V1 is greater than 0 (where V2 = V is the SEAM output in a region of residual stresses, and V1 is the output in a stress-free region of the sample). Under ideal conditions (maximum contrast) V1 approaches zero. It was found that tensile strains of the order 0.2-0.3 percent, possible in brittle materials, would produce a variation of the acoustic output signal of the order 10 nV (about 1 percent), well within the image contrast and signal processing capability of the SEAM electronics.

  8. Scanning electron microscopy of individual nanoparticle bio-markers in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Liv, Nalan, E-mail: n.liv@tudelft.nl; Lazić, Ivan; Kruit, Pieter; Hoogenboom, Jacob P.

    2014-08-01

    We investigated SEM imaging of nanoparticle biomarkers suspended below a thin membrane, with the ultimate goal of integrating functional fluorescence and structural SEM measurements of samples kept at ambient or hydrated conditions. In particular, we investigated how resolving power in liquid SEM is affected by the interaction of the electron beam with the membrane. Simulations with the Geant4-based Monte Carlo scheme developed by Kieft and Bosch (2008) [1] are compared to experimental results with suspended nanoparticles. For 20 nm and 50 nm thin membranes, we found a beam broadening of 1.5 nm and 3 nm, respectively, with an excellent agreement between simulations and experiments. 15 nm Au nanoparticles and bio-functionalized core-shell quantum dots can be individually resolved in denser clusters. We demonstrated the imaging of single EGF-conjugated quantum dots docked at filopodia during cellular uptake with both fluorescence microscopy and SEM simultaneously. These results open novel opportunities for correlating live fluorescence microscopy with structural electron microscopy. - Highlights: • We investigate the achievable resolution in liquid scanning electron microscopy (SEM). • We demonstrate liquid SEM imaging of individual fluorescent nanoparticle bio-markers • We show imaging of cellular QDot uptake with simultaneous fluorescence microscopy and SEM. • The positions of individual QDots can be resolved with details on cellular structure.

  9. Three-dimensional machining of carbon nanotube forests using water-assisted scanning electron microscope processing

    Energy Technology Data Exchange (ETDEWEB)

    Rajabifar, Bahram; Maschmann, Matthew R., E-mail: MaschmannM@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Kim, Sanha; Hart, A. John [Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Slinker, Keith [Materials and Manufacturing Directorate, AFRL/RX, Air Force Research Lab, Ohio 45433 (United States); Universal Technology Corporation, Beavercreek, Ohio 45424 (United States); Ehlert, Gregory J. [Materials and Manufacturing Directorate, AFRL/RX, Air Force Research Lab, Ohio 45433 (United States)

    2015-10-05

    We demonstrate that vertically aligned carbon nanotubes (CNTs) can be precisely machined in a low pressure water vapor ambient using the electron beam of an environmental scanning electron microscope. The electron beam locally damages the irradiated regions of the CNT forest and also dissociates the water vapor molecules into reactive species including hydroxyl radicals. These species then locally oxidize the damaged region of the CNTs. The technique offers material removal capabilities ranging from selected CNTs to hundreds of cubic microns. We study how the material removal rate is influenced by the acceleration voltage, beam current, dwell time, operating pressure, and CNT orientation. Milled cuts with depths between 0–100 microns are generated, corresponding to a material removal rate of up to 20.1 μm{sup 3}/min. The technique produces little carbon residue and does not disturb the native morphology of the CNT network. Finally, we demonstrate direct machining of pyramidal surfaces and re-entrant cuts to create freestanding geometries.

  10. Scanning electron microscope studies of bone samples: Influence of simulated microgravity

    Science.gov (United States)

    Mehta, Rahul; Chowdhury, Parimal; Ali, Nawab

    2007-08-01

    A scanning electron microscope (SEM) with backscatter and secondary electron emission detectors plus a Si(Li) detector for photon yield measurements was used to study bone samples from skull and leg of mice and rats. These animals were either suspended by their tail to induce simulated microgravity, characterized as hind-limb suspension (HLS) or not suspended (control). Analyses of the SEM images and energy dispersive spectrometer (EDS) spectra using Si(Li) detector indicate variation in the lattice structures, and in intensities of the characteristics X-rays, produced from the exposed bone surface due to its interaction with the electron beam. Using Flame software, the X-ray spectra were analyzed and normalized ratios of the elements determined. The elemental analysis indicated a variation in the density of calcium, potassium, and oxygen near the knee joints and near the sutures in the skull bones. The comparison of simulated microgravity subjected samples of the rat skull bones with that of the control samples revealed that in the suture region there was a large increase in the ratio of calcium, and to some degree for phosphorus, suggesting simulated microgravity affects distribution of these elements. Elemental composition for control samples with depth (within the cross section of the leg bones) revealed decrease of oxygen and increase of calcium in the first millimeter of the bone depth after which the relative percentage of elements stayed constant.

  11. Skeletal growth phases of the cold-water coral Lophelia pertusa shown by scanning electron microscope and electron backscatter diffraction

    Science.gov (United States)

    Mouchi, Vincent; Vonlanthen, Pierre; Verrecchia, Eric P.; Crowley, Quentin G.

    2016-04-01

    Lophelia pertusa is a cold-water coral, which may form reefs by the association of multiple coralites within which a polyp lives. Each individual polyp builds an aragonite skeleton by an initial phase of early mineralization (traditionally referred to as centres of calcification) from which aragonite fibres grow in thickening deposits. The skeleton wall features successive optically opaque and translucent bands previously attributed to different regimes of growth as either uniform in crystal orientation (translucent bands) or with a chaotic organization (opaque bands). The processes involved in any organizational changes are still unknown. Microlayers in the coral wall, which represent separate periods of skeletal growth, have been recently identified and described. These growth patterns are readily visible under scanning electron microscope (SEM) after etching in dilute formic acid, but they do not necessarily form continuously visible structures. Here we present high quality SEM images and electron backscatter diffraction (EBSD) maps to study aragonite fibre orientation across the wall of L. pertusa. Both microlayers and opaque and translucent bands are compared to the crystallographic orientation of the aragonite fibres. EBSD maps and SEM images indicate that aragonite fibres do not exhibit a chaotic orientation, even in opaque bands. The absence of continuity of microlayers is partially explained by an association of multiple crystallographic preferred orientations of aragonite fibres. In the case of L. pertusa, careful textural characterisation is necessary prior to elemental or isotope analysis in order to select a skeletal transect representing a linear and continuous time period.

  12. Identifying dislocations and stacking faults in GaN films by scanning transmission electron microscopy

    Science.gov (United States)

    Su, X. J.; Niu, M. T.; Zeng, X. H.; Huang, J.; Zhang, J. C.; Zhang, J. P.; Wang, J. F.; Xu, K.

    2016-08-01

    The application of annular bright field (ABF) and medium-angle annular dark field (MAADF) scanning transmission electron microscopy (STEM) imaging to crystalline defect analysis has been extended to dislocations and stacking faults (SFs). Dislocations and SFs have been imaged under zone-axis and two-beam diffraction conditions. Comparing to conventional two-beam diffraction contrast images, the ABF and MAADF images of dislocations and SFs not only are complementary and symmetrical with their peaks at dislocation core and SFs plane, but also show similar extinction phenomenon. It is demonstrated that conventional TEM rules for diffraction contrast, i.e. g · b and g · R invisibility criteria remain applicable. The contrast mechanism and extinction of dislocation and SFs in ABF and MAADF STEM are illuminated by zero-order Laue zone Kikuchi diffraction.

  13. CHARACTERIZATION OF REFINED HEMP FIBERS USING NIR FT RAMAN MICRO SPECTROSCOPY AND ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Siva Kumar Kovur

    2008-11-01

    Full Text Available The research was focused on the separation of single hemp (Cannabis sativa L. fibre cells with low fineness from mechanically extracted fibre bundles of high fineness. The fiber bundles were treated with enzymes, namely panzym, pectinase, hemicellulase, and cellulase, along with a combination of panzym and ultrasonic treatments. Changes in the fiber structure were followed at molecular and microscopic levels by means of NIR FT Raman spectroscopy and Environmental Scanning Electron Microscopy (ESEM. Buffer-panzym treatments of hemp fibers had a prominent effect in loosening of the fiber cells. The best of refining was achieved when the fiber bundles were treated with buffer-panzym solution in combination with ultrasonic treatment.

  14. Scanning Electron Microscopic Observation on Morphologic Characteristics of Sperms in Uremic Patients

    Institute of Scientific and Technical Information of China (English)

    Long-gen XU; Shi-fang SHI; Hai-zhen ZHONG; Xiao-feng HUANG; Xiao-ping QI; Qi-zhe SONG; Xin-hong WANG; Li YAN; Zong-fu SHAO

    2004-01-01

    Objective To observe the morphologic characteristics of spermatozoon ultramicro scopic structure in uremic subjects Method Semen sample from 10 patients with uremia and 5 healthy men were observed under light microscope and scanning electronic microscope.Results Abnormalities were found in sperms of uremic patients either in the sperm head (acrosome, acrosomic deficit, nuclear abnormality, pointed head, headless and double head of spermatozoon), neck (rupture, separation and enlargement), or tail (mitochondrial swelling, mitochondrial deficit, tailless, double tail, short tail and curled tail); whereas none of the above-mentioned abnormalities was observed in healthy men.Conclusion Sperms of uremic patients had many morphologic and structural abnor malities in the head, neck and tail.

  15. Analysis of Vero cell growth behavior on microcarrier by means of environmental scanning electron microscopy

    Institute of Scientific and Technical Information of China (English)

    邵曼君; 姜蕾; 丛威; 欧阳藩

    2002-01-01

    By using environmental scanning electron microscopy, the morphological changes of Vero cells attached to and grown on the microcarrier Cytodex-3 were observed, and their behavior of adhesion, spreading and proliferation was analyzed. The effect of exogenous fibronectin/ laminin on adhesion and spreading of MCC/Vero cell was studied. The images of ESEM showed that expansion of cell growth was directed toward vacancy space. The growth curve and cell concentration change during the whole culture process were obtained from the statistical counting method based on ESEM images and the crystal violet method. The growth rate of Vero cells increases with increasing the concentration of cell inoculation, that is, the specific growth rate increases quickly with increasing the concentration of cell inoculation. When serum concentration in medium #199 ranged from 5% to 10%, experimental results indicated that serum concentration is one of the important factors influencing cell growth, particularly in the cell adhesion and spreading stage.

  16. Devolatilization Studies of Oil Palm Biomass for Torrefaction Process through Scanning Electron Microscopy

    Science.gov (United States)

    Daud, D.; Abd. Rahman, A.; Shamsuddin, A. H.

    2016-03-01

    In this work, palm oil biomass consisting of empty fruit bunch (EFB), mesocarp fibre and palm kernel shell (PKS) were chosen as raw material for torrefaction process. Torrefaction process was conducted at various temperatures of 240 °C, 270 °C and 300 °C with a residence time of 60 minutes. The morphology of the raw and torrefied biomass was then observed through Scanning Electron Microscopy (SEM) images. Also, through this experiment the correlation between the torrefaction temperatures with the volatile gases released were studied. From the observation, the morphology structure of the biomass exhibited inter-particle gaps due to the release of volatile gases and it is obviously seen more at higher temperatures. Moreover, the change of the biomass structure is influenced by the alteration of the lignocellulose biomass.

  17. Scanning electron microscopic study of trophozoite and cyst stages of Naegleria fowleri.

    Science.gov (United States)

    Antonios, Sanaa N

    2010-04-01

    Whole trophozoites and cysts of axenically cultivated Naegleria fowleri were prepared for study of their surface morphology by scanning electron microscopy (SEM). Trophozoites and cyst stages were studied from Chang's culture media. Some trophozoites were examined after animal inoculation and brain isolation to compare the changes in surface features. Photomicrographs of freeze-dried and critical point-dried organisms fixed with glutaraldehyde were presented along with views of both isolates of trophozoites to compare the surface features. SEM revealed the surface of trophozoites to be undulating, wrinkled and covered at irregular intervals by protruding vesicles. There were also surface extensions which were long and thin in brain isolates which may help in the contact and cytolysis of host cells at some distance from the trophozoite. Some cysts appeared wrinkled while others smooth, and empty cysts were also seen with many pores on the surface.

  18. A morphological study of molecularly imprinted polymers using the scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Paniagua Gonzalez, Gema [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), 28040 Madrid (Spain)]. E-mail: gpaniagua@pas.uned.es; Fernandez Hernando, Pilar [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), 28040 Madrid (Spain); Durand Alegria, J.S. [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), 28040 Madrid (Spain)

    2006-01-31

    Molecular imprinting is an emerging technique for producing polymers with applications in affinity-based separation, in biomimetic sensors, in catalysis, etc. This variety of uses relies upon the production of polymers with different affinities, specificities, sensitivities and loading capacities. Research into the development of molecular imprinted polymers (MIPs) with new or improved morphologies - which involves modification of the polymerisation process - is therefore underway. This paper reports a comparative study of non-covalent MIPs synthesised by 'bulk' polymerisation using digoxin as template. These were synthesised under different conditions, i.e., changing the functional monomers employed (methacrylic acid or 2-vinylpyridine), the porogens (acetonitrile or dichloromethane) used, and by altering the volume of the latter. The polymerisation process was allowed to proceed either under UV light or in a thermostat-controlled waterbath. The surface morphology (was determined by scanning electron microscopy) and the ability of the different polymers to selectively rebind the template was then evaluated.

  19. Bright-field imaging of compound semiconductors using aberration-corrected scanning transmission electron microscopy

    Science.gov (United States)

    Aoki, Toshihiro; Lu, Jing; McCartney, Martha R.; Smith, David J.

    2016-09-01

    This study reports the observation of six different zincblende compound semiconductors in [110] projection using large-collection-angle bright-field (LABF) imaging with an aberration-corrected scanning transmission electron microscope. Phase contrast is completely suppressed when the collection semi-angle is set equal to the convergence semi-angle and there are no reversals in image contrast with changes in defocus or thickness. The optimum focus for imaging closely separated pairs of atomic columns (‘dumbbells’) is unique and easily recognized, and the positions of atomic columns occupied by heavier atoms always have darker intensity than those occupied by lighter atoms. Thus, the crystal polarity of compound semiconductors can be determined unambiguously. Moreover, it is concluded that the LABF imaging mode will be highly beneficial for studying other more complicated heterostructures at the atomic scale.

  20. Investigation of electron transfer across the ice/liquid interface by scanning electro-chemical microscopy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The study of interfacial electron transfer (ET) reaction between ferricinium (Fc+) produced in situ in 1,2-dichloroethane (DCE) and ferrocyanide in ice matrix under low temperatures by the scanning electrochemical microscopy (SECM) is reported. Tetrabutylammonium (TBA+) is used as the common ion (potential-determining ion) in both phases to control the interfacial potential difference. The potential drop across the liquid/liquid interface can be quantitatively adjusted by changing the ratio of concentrations of TBA+ between the two phases. The apparent heterogeneous rate constants for Fc+ reduction by at the interface under different temperatures have been obtained by a best-fit analysis, where the experimental approach curves are fitted to the theoretical simulated curves. A sharp change has been observed for heterogeneous rate constants around the freezing point of the aqueous phase, which reflects the phase transition process.

  1. Evaluation of vermicompost maturity using scanning electron microscopy and paper chromatography analysis.

    Science.gov (United States)

    Senthil Kumar, D; Satheesh Kumar, P; Rajendran, N M; Uthaya Kumar, V; Anbuganapathi, G

    2014-04-01

    Vermicompost was produced from flower waste inoculated with biofertilizers using the earthworm Eisenia fetida. Principal component analysis (PCA) and cluster analysis (CA) were carried out on the basis of physicochemical parameters of vermicomposted samples. From the results of the PCA and CA, it was possible to classify two different groups of vermicompost samples in the following categories: E2 and E5; and E1, E3, E4, and control. Scanning electron microscopy and biodynamic circular paper chromatography analysis were used to investigate the changes in surface morphology and functional groups in the control and vermicompost products. SEM analysis of E1-E5 shows more fragment and pores than the control. Chromatographic analysis of vermicompost indicated the mature condition of the compost materials. PMID:24634991

  2. Scanning electron microscopic studies of cultured alveolar macrophages and chrysotile asbestos

    International Nuclear Information System (INIS)

    The physical and chemical characteristics of asbestos and its associated biological toxicity have attracted a good deal of study. While physical factors such as fiber length and surface area may affect the biological response, recent findings suggest that surface charge properties play an important role in asbestos toxocity. To investigate the role of these factors, cultured bovine alveolar macrophages (BAM) were exposed to Canadian chrysotile asbestos samples pretreated by varous means. It was found that heat pretreatment of asbestos reduced cytotoxocity to BAM compared with untreated asbestos. Interestingly, subsequent x-irradiation of heat pretreated asbestos restored cytotoxicity to original (untreated) levels. Scanning electron microscopic evaluations were carried out to determine if pretreatment altered the size distribution of fiber fragments or if BAM interacted with different pretreatments in different ways

  3. A novel and compact nanoindentation device for in situ nanoindentation tests inside the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Hu Huang

    2012-03-01

    Full Text Available In situ nanomechanical tests provide a unique insight into mechanical behaviors of materials, such as fracture onset and crack propagation, shear band formation and so on. This paper presents a novel in situ nanoindentation device with dimensions of 103mm×74mm×60mm. Integrating the stepper motor, the piezoelectric actuator and the flexure hinge, the device can realize coarse adjustment of the specimen and precision loading and unloading of the indenter automatically. A novel indenter holder was designed to guarantee that the indenter penetrates into and withdraws from the specimen surface vertically. Closed-loop control of the indentation process was established to solve the problem of nonlinearity of the piezoelectric actuator and to enrich the loading modes. The in situ indentation test of Indium Phosphide (InP inside the scanning electron microscope (SEM was carried out and the experimental result indicates the feasibility of the developed device.

  4. Analysis of Vero cell growth behavior on microcarrier by means of environmental scanning electron microscopy.

    Science.gov (United States)

    Shao, Manjun; Jiang, Lei; Cong, Wei; Ouyang, Fan

    2002-04-01

    By using environmental scanning electron microscopy, the morphological changes of Vero cells attached to and grown on the microcarrier Cytodex-3 were observed, and their behavior of adhesion, spreading and proliferation was analyzed. The effect of exogenous fibronectin/ laminin on adhesion and spreading of MCC/Vero cell was studied. The images of ESEM showed that expansion of cell growth was directed toward vacancy space. The growth curve and cell concentration change during the whole culture process were obtained from the statistical counting method based on ESEM images and the crystal violet method. The growth rate of Vero cells increases with increasing the concentration of cell inoculation, that is, the specific growth rate increases quickly with increasing the concentration of cell inoculation. When serum concentration in medium #199 ranged from 5% to 10%, experimental results indicated that serum concentration is one of the important factors influencing cell growth, particularly in the cell adhesion and spreading stage. PMID:18763074

  5. Morphological study of Tetratrichomonas didelphidis isolated from opossum Lutreolina crassicaudata by scanning electron microscopy.

    Science.gov (United States)

    Tasca, Tiana; De Carli, Geraldo Attilio

    2007-05-01

    Tetratrichomonas didelphidis is a flagellate protozoan found in the intestine of opossums Didelphis marsupialis, Didelphis albiventris, and Lutreolina crassicaudata. The isolate used in this study was from L. crassicaudata and it was cultivated in monoxenic culture with Escherichia coli in Diamond (TYM) medium without maltose and with starch solution (trypticase-yeast extract-starch), pH 7.5 at 28 degrees C. Scanning electron microscopy showed the fine morphological features of the trophozoites: the emergence of the anterior flagella, the structure of the undulating membrane, the axostyle and posterior flagellum. In addition, we described spherical forms that are probably pseudocysts. Our data will contribute to a better understanding of surface structures in T. didelphidis. PMID:17252276

  6. Fundamentals of overlay measurement and inspection using scanning electron-microscope

    Science.gov (United States)

    Kato, T.; Okagawa, Y.; Inoue, O.; Arai, K.; Yamaguchi, S.

    2013-04-01

    Scanning electron-microscope (SEM) has been successfully applied to CD measurement as promising tools for qualifying and controlling quality of semiconductor devices in in-line manufacturing process since 1985. Furthermore SEM is proposed to be applied to in-die overlay monitor in the local area which is too small to be measured by optical overlay measurement tools any more, when the overlay control limit is going to be stringent and have un-ignorable dependence on device pattern layout, in-die location, and singular locations in wafer edge, etc. In this paper, we proposed new overlay measurement and inspection system to make an effective use of in-line SEM image, in consideration of trade-off between measurement uncertainty and measurement pattern density in each SEM conditions. In parallel, we make it clear that the best hybrid overlay metrology is in considering each tool's technology portfolio.

  7. Applications of environmental scanning electron microscopy (ESEM) in the study of novel drying latex films

    Energy Technology Data Exchange (ETDEWEB)

    Dragnevski, K I; Donald, A M [Sector of Biological and Soft Systems, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 OHE (United Kingdom)], E-mail: kd281@cam.ac.uk

    2008-08-15

    We have employed Environmental Scanning Electron Microscopy (ESEM) and Energy Dispersive X-ray (EDX) analysis to study the microstructural evolution of acrylic latex stabilised with a novel polysaccharide derived from agricultural waste. The analysis revealed that the micro structure of the latex in the 'wet' state consists of individual particles and clusters. Upon evaporation a discontinuous film is formed, with voids present within its structure, which is inconsistent with the conventional descriptions of film formation. Further ESEM examination of 'dry' specimens revealed that aging resulted in the formation of dendritic structures on the surfaces of the latex films, which EDX analysis confirmed to have been formed via crystallisation of salt. The experimental evidence suggests that the clusters, which are part of the structure of the latex, may act as nucleation centres that would allow the dendrites to form.

  8. Equalization of Ti-6Al-4 V alloy welded joint by scanning electron beam welding

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The equalization of Ti-6Al-4V alloy welded joint with base metal on corrosion resistance, strength and ductility was studied. The solidification microstructure is transformed from 650 μm columnar grains to 100 μm equiaxed grains by scanning electron beam welding. The anodic polarization curve of 150 μm equiaxed grains coincides with that of base metal. Equal corrosion resistance between weld metal and base metal was ob tained. Uniform microstructure and solutedistribution are the basis of equalization. Corrosion rate of weld with 150 μm equiaxed grains is the lowest, 2.45 times lower than that of 650 μm columnar grains. Weld strength is 98% as much as that of base metal, yield-strength ratio is 99.5%, which is 3.6% higher than that of base metal.

  9. Donkey dental anatomy. Part 2: Histological and scanning electron microscopic examinations.

    Science.gov (United States)

    Du Toit, N; Kempson, S A; Dixon, P M

    2008-06-01

    Ten normal cheek teeth (CT) were extracted at post mortem from donkeys that died or were euthanased for humane reasons. Decalcified histology was performed on three sections (sub-occlusal, mid-tooth and pre-apical) of each tooth, and undecalcified histology undertaken on sub-occlusal sections of the same teeth. The normal histological anatomy of primary, regular and irregular secondary dentine was found to be similar to that of the horse, with no tertiary dentine present. Undecalcified histology demonstrated the normal enamel histology, including the presence of enamel spindles. Scanning electron microscopy was performed on mid-tooth sections of five maxillary CT, five mandibular CT and two incisors. The ultrastructural anatomy of primary and secondary dentine, and equine enamel types-1, -2 and -3 (as described in horses) were identified in donkey teeth. Histological and ultrastructural donkey dental anatomy was found to be very similar to equine dental anatomy with only a few quantitative differences observed.

  10. Quantitative scanning electron microscopic autoradiography of inhaled 239PuO2

    International Nuclear Information System (INIS)

    We have applied the scanning electron microscope (SEM) to obtain autoradiographs of particles of 239PuO2 deposited in rat lung. The technique was used to obtain quantitative information on the clearance rates of particles from the alveoli, bronchioles and trachea up to 240 d after exposure. At all times, the concentration of particles on the surface of the bronchioles was an order of magnitude greater than on the tracheal surface. The clearance of Pu from both regions followed a biphasic pattern, similar to that obtained by radiometric analysis of the whole lung. Most of the radiation dose to the bronchiolar epithelium originated from Pu particles in peribronchiolar alveoli in which they were preferentially retained, compared to other alveolar regions. The prolonged retention of particles in the peribronchiolar alveoli may be a significant factor in the induction of lung carcinomas

  11. Effects of acetylcysteine on rabbit conjunctival and corneal surfaces. A scanning electron microscopy study.

    Science.gov (United States)

    Thermes, F; Molon-Noblot, S; Grove, J

    1991-10-01

    Conjunctival and corneal epithelial surfaces of normal rabbit eyes with their associated mucus were studied by scanning electron microscopy before and after treatment with the mucolytic agent N-acetylcysteine (AC). Four groups received topically one 50-microliters drop of either (Group A) 0.1 MAC, (Group B) 0.1 M AC every 5 min for 1 hr, (Group C) 0.1 M AC every 5 min for 2 hr, or (Group D) three drops of 20% AC over 15 min. The effects of the instillation of AC on mucus removal and cellular lesions increased in the order (A) less than (B) less than (C) less than (D). Treatment A had no effect on cornea and conjunctiva. Treatment B cleaned away mucosal debris without alteration of either conjunctival or corneal epithelium. Treatment C had a similar effect on the mucus but was associated with focal necrosis, and treatment D produced widespread necrosis, desquamation of epithelial cells, and inflammation.

  12. Scanning electron microscopy of damage to the cecal mucosa of turkeys infected with Eimeria adenoides.

    Science.gov (United States)

    Bemrick, W J; Hammer, R F

    1979-01-01

    White Wrolstad turkeys were each inoculated with 100,000 Eimeria adenoides oocysts and killed on days 4-14 postinoculation. Tissue samples, obtained from 4 areas of the ceca comparable to areas examined in chickens infected with E. tenella in previous studies, were processed by a modification of the osmium-thiocarbo-hydrazide-osmium technique and examined with a scanning electron microscope. The pathologic situation found in turkeys was slightly different from that in the ceca of chickens infected with E. tenella. The mucosal lesions are most severe at the proximal end of an infected cecum. Surface disruption was far less severe than with cecal coccidiosis in chickens of the same age exposed to an equal number of infective oocysts. Rupture of the epithelial cell often caused the mucosal surface to present a honeycomb appearance. Some specific stages of the life cycle were identified, including schizonts and oocysts.

  13. Determination of the coalescence temperature of latexes by environmental scanning electron microscopy.

    Science.gov (United States)

    Gonzalez, Edurne; Tollan, Christopher; Chuvilin, Andrey; Barandiaran, Maria J; Paulis, Maria

    2012-08-01

    A new methodology for quantitative characterization of the coalescence process of waterborne polymer dispersion (latex) particles by environmental scanning electron microscopy (ESEM) is proposed. The experimental setup has been developed to provide reproducible latex monolayer depositions, optimized contrast of the latex particles, and a reliable readout of the sample temperature. Quantification of the coalescence process under dry conditions has been performed by image processing based on evaluation of the image autocorrelation function. As a proof of concept the coalescence of two latexes with known and differing glass transition temperatures has been measured. It has been shown that a reproducibility of better than 1.5 °C can be obtained for the measurement of the coalescence temperature.

  14. Investigation of Nematode Diversity using Scanning Electron Microscopy and Fluorescent Microscopy

    Science.gov (United States)

    Seacor, Taylor; Howell, Carina

    2013-03-01

    Nematode worms account for the vast majority of the animals in the biosphere. They are colossally important to global public health as parasites, and to agriculture both as pests and as beneficial inhabitants of healthy soil. Amphid neurons are the anterior chemosensory neurons in nematodes, mediating critical behaviors including chemotaxis and mating. We are examining the cellular morphology and external anatomy of amphid neurons, using fluorescence microscopy and scanning electron microscopy, respectively, of a wide range of soil nematodes isolated in the wild. We use both classical systematics (e.g. diagnostic keys) and molecular markers (e.g. ribosomal RNA) to classify these wild isolates. Our ultimate aim is to build a detailed anatomical database in order to dissect genetic pathways of neuronal development and function across phylogeny and ecology. Research supported by NSF grants 092304, 0806660, 1058829 and Lock Haven University FPDC grants

  15. Examination of Scanning Electron Microscope and Computed Tomography Images of PICA

    Science.gov (United States)

    Lawson, John W.; Stackpoole, Margaret M.; Shklover, Valery

    2010-01-01

    Micrographs of PICA (Phenolic Impregnated Carbon Ablator) taken using a Scanning Electron Microscope (SEM) and 3D images taken with a Computed Tomography (CT) system are examined. PICA is a carbon fiber based composite (Fiberform ) with a phenolic polymer matrix. The micrographs are taken at different surface depths and at different magnifications in a sample after arc jet testing and show different levels of oxidative removal of the charred matrix (Figs 1 though 13). CT scans, courtesy of Xradia, Inc. of Concord CA, were captured for samples of virgin PICA, charred PICA and raw Fiberform (Fig. 14). We use these images to calculate the thermal conductivity (TC) of these materials using correlation function (CF) methods. CF methods give a mathematical description of how one material is embedded in another and is thus ideally suited for modeling composites like PICA. We will evaluate how the TC of the materials changes as a function of surface depth. This work is in collaboration with ETH-Zurich, which has expertise in high temperature materials and TC modeling (including CF methods).

  16. Preliminary Study of In Vivo Formed Dental Plaque Using Confocal Microscopy and Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    KA. Al-Salihi

    2009-12-01

    Full Text Available Objective: Confocal laser scanning microscopy (CLSM is relatively a new light microscopical imaging technique with a wide range of applications in biological sciences. The primary value of CLSM for the biologist is its ability to provide optical sections from athree-dimensional specimen. The present study was designed to assess the thickness and content of in vivo accumulated dental plaque using CLSM and scanning electron microscopy (SEM.Materials and Methods: Acroflat lower arch splints (acrylic appliance were worn by five participants for three days without any disturbance. The formed plaques were assessed using CLSM combined with vital fluorescence technique and SEM.Results: In this study accumulated dental plaque revealed varied plaque microflora vitality and thickness according to participant’s oral hygiene. The thickness of plaque smears ranged from 40.32 to 140.72 μm and 65.00 to 128.88 μm for live (vital and dead accumulated microorganisms, respectively. Meanwhile, the thickness of plaque on the appliance ranged from 101 μm to 653 μm. CLSM revealed both dead and vital bacteria on the surface of the dental plaque. In addition, SEM revealed layers of various bacterial aggregations in all dental plaques.Conclusion: This study offers a potent non-invasive tool to evaluate and assess the dental plaque biofilm, which is a very important factor in the development of dental caries.

  17. A sensitive charge scanning probe based on silicon single electron transistor

    Science.gov (United States)

    Lina, Su; Xinxing, Li; Hua, Qin; Xiaofeng, Gu

    2016-04-01

    Single electron transistors (SETs) are known to be extremely sensitive electrometers owing to their high charge sensitivity. In this work, we report the design, fabrication, and characterization of a silicon-on-insulator-based SET scanning probe. The fabricated SET is located about 10 μm away from the probe tip. The SET with a quantum dot of about 70 nm in diameter exhibits an obvious Coulomb blockade effect measured at 4.1 K. The Coulomb blockade energy is about 18 meV, and the charge sensitivity is in the order of 10‑5‑10‑3 e/Hz1/2. This SET scanning probe can be used to map charge distribution and sense dynamic charge fluctuation in nanodevices or circuits under test, realizing high sensitivity and high spatial resolution charge detection. Project supported by the Instrument Developing Project of the Chinese Academy of Sciences (No. YZ201152), the National Natural Science Foundation of China (No. 11403084), the Fundamental Research Funds for Central Universities (Nos. JUSRP51510, JUDCF12032), and the Graduate Student Innovation Program for Universities of Jiangsu Province (No. CXLX12_0724).

  18. Use of scanning electron microscopy to monitor nanofibre/cell interaction in digestive epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Millaku, Agron, E-mail: agron.mi@hotmail.com [Limnos-Company for Applied Ecology Ltd, Podlimbarskega 31, 1000 Ljubljana (Slovenia); Drobne, Damjana [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia); Centre of Excellence, Advanced Materials and Technologies for the Future (CO NAMASTE), Jamova cesta 39, 1000 Ljubljana (Slovenia); Centre of Excellence, Nanoscience and Nanotechnology (Nanocentre), Jamova cesta 39, 1000 Ljubljana (Slovenia); Torkar, Matjaz [Institute of Metals and Technology IMT, Lepi pot 11, 1000 Ljubljana (Slovenia); Jožef Stefan Institute, Condensed Matter Physics Department, Jamova cesta 39, 1000 Ljubljana (Slovenia); Novak, Sara [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia); Remškar, Maja [Jožef Stefan Institute, Condensed Matter Physics Department, Jamova cesta 39, 1000 Ljubljana (Slovenia); Pipan-Tkalec, Živa [University of Ljubljana, Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana (Slovenia)

    2013-09-15

    Graphical abstract: Scanning electron microscopy is particularly well suited to the observation of nanofibre/cell interaction in the endothelial cells lining the hepatopancreas. (a) Tungsten oxide nanofibres, (b) test organism Porcellio scaber and schematic appearance of digestive tubes, (c) digestive tube (hepatopancreas) prepared for SEM investigation, (d) digestive gland cells (C) with nanofibres (NF) embedded in the cell membrane and (e) nanofibres inserted deeply in the cells and damaged nanofibres due to peristalsis. -- Highlights: • Tungsten oxide nanofibres react physically with digestive gland epithelial cells in Porcellio scaber. • Physical peristaltic forces of lead to insertion of nanofibres into the cells. • No toxic responses as measured by conventional toxicity biomarkers were detected. • Physical interactions were observed in a majority of the investigated animals. -- Abstract: We provide data obtained by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) on the interaction of ingested tungsten nanofibers with epithelial cells of the digestive tubes of a test organism Porcellio scaber. Conventional toxicity endpoints including feeding behaviour, weight loss and mortality were also measured in each investigated animal. No toxicity was detected in any of exposed animals after 14 days of feeding on tungsten nanofiber dosed food, but when nanofibers enter the digestive system they can react with epithelial cells of the digestive tubes, becoming physically inserted into the cells. In this way, nanofibers can injure the epithelial cells of digestive gland tubes when they are ingested with food. Our SEM data suggest that peristaltic forces may have an important role, not predicted by in vitro experiments, in the interactions of nanomaterials with digestive intestinal cells.

  19. Use of scanning electron microscopy to monitor nanofibre/cell interaction in digestive epithelial cells

    International Nuclear Information System (INIS)

    Graphical abstract: Scanning electron microscopy is particularly well suited to the observation of nanofibre/cell interaction in the endothelial cells lining the hepatopancreas. (a) Tungsten oxide nanofibres, (b) test organism Porcellio scaber and schematic appearance of digestive tubes, (c) digestive tube (hepatopancreas) prepared for SEM investigation, (d) digestive gland cells (C) with nanofibres (NF) embedded in the cell membrane and (e) nanofibres inserted deeply in the cells and damaged nanofibres due to peristalsis. -- Highlights: • Tungsten oxide nanofibres react physically with digestive gland epithelial cells in Porcellio scaber. • Physical peristaltic forces of lead to insertion of nanofibres into the cells. • No toxic responses as measured by conventional toxicity biomarkers were detected. • Physical interactions were observed in a majority of the investigated animals. -- Abstract: We provide data obtained by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) on the interaction of ingested tungsten nanofibers with epithelial cells of the digestive tubes of a test organism Porcellio scaber. Conventional toxicity endpoints including feeding behaviour, weight loss and mortality were also measured in each investigated animal. No toxicity was detected in any of exposed animals after 14 days of feeding on tungsten nanofiber dosed food, but when nanofibers enter the digestive system they can react with epithelial cells of the digestive tubes, becoming physically inserted into the cells. In this way, nanofibers can injure the epithelial cells of digestive gland tubes when they are ingested with food. Our SEM data suggest that peristaltic forces may have an important role, not predicted by in vitro experiments, in the interactions of nanomaterials with digestive intestinal cells

  20. Scanning electron microscopic observation: three-dimensional architecture of the collagen in hepatic fibrosis rats

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-hong; ZHAO Jing; ZHANG Wei-guang; ZHANG Li-ying; MA Rui-qiong; WANG Li-qin; ZHANG Shu-yong; TIAN Long

    2007-01-01

    Background In the process of hepatic fibrosis, the accumulation of collagen fibers is strongly related to the hepatic function. The aim of this study was to investigate the three-dimensional architecture of the collagen network in the liver of rats with hepatic fibrosis.Methods Healthy adult male Wistar rats (n=32) were randomly divided into a control group (n=16) and a hepatic fibrosis group (n=16). In the control group, the rats were treated with peanut oil while the rats in hepatic fibrosis group were treated for 10 weeks with 60% CCl4 diluted in peanut oil. The quantity of collagen fibers was detected by Western blotting; distribution of the collagen was detected by sirius red staining and polarized microscope; the three-dimensional architecture of collagen in the liver was observed under the scanning electron microscope after fixed tissues were treated with cell-maceration using NaOH. Statistical analysis was performed using the u test.Results The quantity of collagen fibers increased significantly in the hepatic fibrosis group. With the aggravation of hepatic fibrosis, collagen fibers gradually accumulated. They interlaced the reticulation compartment and formed a round or ellipse liver tissue conglomeration like a grape framework that was disparate and wrapped up the normal liver Iobule.The deposition of collagen fibers was obvious in adjacent hepatic parenchyma, especially around the portal tracts.Conclusion Our experiment showed the collagen proliferation and displays clearly the three-dimensional architecture of collagen fibers in rat liver with hepatic fibrosis by scanning electron microscope. It can provide a morphological foundation for the mechanisms of changed haemodynamics and portal hypertension in hepatic fibrosis.

  1. Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy.

    Science.gov (United States)

    Ogura, Toshihiko

    2010-01-01

    Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si(3)N(4)) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si(3)N(4) film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes.

  2. Composition mapping in InGaN by scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    We suggest a method for chemical mapping that is based on scanning transmission electron microscopy (STEM) imaging with a high-angle annular dark field (HAADF) detector. The analysis method uses a comparison of intensity normalized with respect to the incident electron beam with intensity calculated employing the frozen lattice approximation. This procedure is validated with an In0.07Ga0.93N layer with homogeneous In concentration, where the STEM results were compared with energy filtered imaging, strain state analysis and energy dispersive X-ray analysis. Good agreement was obtained, if the frozen lattice simulations took into account static atomic displacements, caused by the different covalent radii of In and Ga atoms. Using a sample with higher In concentration and series of 32 images taken within 42 min scan time, we did not find any indication for formation of In rich regions due to electron beam irradiation, which is reported in literature to occur for the parallel illumination mode. Image simulation of an In0.15Ga0.85N layer that was elastically relaxed with empirical Stillinger-Weber potentials did not reveal significant impact of lattice plane bending on STEM images as well as on the evaluated In concentration profiles for specimen thicknesses of 5, 15 and 50 nm. Image simulation of an abrupt interface between GaN and In0.15Ga0.85N for specimen thicknesses up to 200 nm showed that artificial blurring of interfaces is significantly smaller than expected from a simple geometrical model that is based on the beam convergence only. As an application of the method, we give evidence for the existence of In rich regions in an InGaN layer which shows signatures of quantum dot emission in microphotoluminescence spectroscopy experiments. -- Highlights: → Composition mapping in InGaN using quantitative STEM. → No electron beam induced In clustering in InGaN observed for STEM. → Small influence of lattice plane bending for STEM of InGaN/GaN. → In composition

  3. Correlative scanning electron and confocal microscopy imaging of labeled cells coated by indium-tin-oxide.

    Science.gov (United States)

    Rodighiero, Simona; Torre, Bruno; Sogne, Elisa; Ruffilli, Roberta; Cagnoli, Cinzia; Francolini, Maura; Di Fabrizio, Enzo; Falqui, Andrea

    2015-06-01

    Confocal microscopy imaging of cells allows to visualize the presence of specific antigens by using fluorescent tags or fluorescent proteins, with resolution of few hundreds of nanometers, providing their localization in a large field-of-view and the understanding of their cellular function. Conversely, in scanning electron microscopy (SEM), the surface morphology of cells is imaged down to nanometer scale using secondary electrons. Combining both imaging techniques have brought to the correlative light and electron microscopy, contributing to investigate the existing relationships between biological surface structures and functions. Furthermore, in SEM, backscattered electrons (BSE) can image local compositional differences, like those due to nanosized gold particles labeling cellular surface antigens. To perform SEM imaging of cells, they could be grown on conducting substrates, but obtaining images of limited quality. Alternatively, they could be rendered electrically conductive, coating them with a thin metal layer. However, when BSE are collected to detect gold-labeled surface antigens, heavy metals cannot be used as coating material, as they would mask the BSE signal produced by the markers. Cell surface could be then coated with a thin layer of chromium, but this results in a loss of conductivity due to the fast chromium oxidation, if the samples come in contact with air. In order to overcome these major limitations, a thin layer of indium-tin-oxide was deposited by ion-sputtering on gold-decorated HeLa cells and neurons. Indium-tin-oxide was able to provide stable electrical conductivity and preservation of the BSE signal coming from the gold-conjugated markers. PMID:25810353

  4. Correlative scanning electron and confocal microscopy imaging of labeled cells coated by indium-tin-oxide

    KAUST Repository

    Rodighiero, Simona

    2015-03-22

    Confocal microscopy imaging of cells allows to visualize the presence of specific antigens by using fluorescent tags or fluorescent proteins, with resolution of few hundreds of nanometers, providing their localization in a large field-of-view and the understanding of their cellular function. Conversely, in scanning electron microscopy (SEM), the surface morphology of cells is imaged down to nanometer scale using secondary electrons. Combining both imaging techniques have brought to the correlative light and electron microscopy, contributing to investigate the existing relationships between biological surface structures and functions. Furthermore, in SEM, backscattered electrons (BSE) can image local compositional differences, like those due to nanosized gold particles labeling cellular surface antigens. To perform SEM imaging of cells, they could be grown on conducting substrates, but obtaining images of limited quality. Alternatively, they could be rendered electrically conductive, coating them with a thin metal layer. However, when BSE are collected to detect gold-labeled surface antigens, heavy metals cannot be used as coating material, as they would mask the BSE signal produced by the markers. Cell surface could be then coated with a thin layer of chromium, but this results in a loss of conductivity due to the fast chromium oxidation, if the samples come in contact with air. In order to overcome these major limitations, a thin layer of indium-tin-oxide was deposited by ion-sputtering on gold-decorated HeLa cells and neurons. Indium-tin-oxide was able to provide stable electrical conductivity and preservation of the BSE signal coming from the gold-conjugated markers. © 2015 Wiley Periodicals, Inc.

  5. Maskless, High-Precision, Persistent, and Extreme Wetting-Contrast Patterning in an Environmental Scanning Electron Microscope.

    Science.gov (United States)

    Liimatainen, Ville; Shah, Ali; Johansson, Leena-Sisko; Houbenov, Nikolay; Zhou, Quan

    2016-04-13

    A maskless and programmable direct electron beam writing method is reported for making high-precision superhydrophilic-superhydrophobic wetting patterns with 152° contact angle contrast using an environmental scanning electron microscope (ESEM). The smallest linewidth achieved is below 1 μm. The reported effects of the electron beam induced local plasma may also influence a variety of microscopic wetting studies in ESEM. PMID:26880568

  6. Scanning probe microscopy investigation of self-organized perylenetetracarboxdiimide nanostructures at surfaces: structural and electronic properties.

    Science.gov (United States)

    Palermo, Vincenzo; Liscio, Andrea; Gentilini, Desirée; Nolde, Fabian; Müllen, Klaus; Samorì, Paolo

    2007-01-01

    A scanning probe microscopy investigation of the self-organization and local electronic properties of spin-coated ultrathin films of N-alkyl substituted perylenetetracarboxdiimide (PDI) is described. By carefully balancing the interplay between molecule-molecule and molecule-substrate interactions, PDI is able to form highly ordered supramolecular architectures on flat surfaces from solution. On an electrically insulating yet highly polar surface (mica) PDI forms strongly anisotropic architectures with needlelike structures with lengths of up to a few micrometers. On a conductive yet apolar surface (highly oriented pyrolytic graphite), the competition between the strong molecule-substrate interactions and the intermolecular forces leads to the generation of more disordered structures. The local electronic properties of these architectures are studied by Kelvin probe force microscopy by estimating their surface potential (SP). Quantitative measurements of the SP are obtained by analyzing the experimentally estimated SP data with a computational model, which discriminates between the intrinsic SP and the effect of long-range tip-surface interactions. The SP of PDI aggregates depends on the structural order at the supramolecular level. Narrow needles of constant width reveal identical SPs independent of length. Wider needles with a polydisperse width distribution exhibit a greater SP.

  7. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy.

    Science.gov (United States)

    Sun, Jingya; Adhikari, Aniruddha; Shaheen, Basamat S; Yang, Haoze; Mohammed, Omar F

    2016-03-17

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser's relatively large penetration depth and consequently these techniques record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and subpicosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample's surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystal and its powder film. We also discuss the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  8. Mapping Carrier Dynamics on Material Surfaces in Space and Time using Scanning Ultrafast Electron Microscopy

    KAUST Repository

    Sun, Jingya

    2016-02-25

    Selectively capturing the ultrafast dynamics of charge carriers on materials surfaces and at interfaces is crucial to the design of solar cells and optoelectronic devices. Despite extensive research efforts over the past few decades, information and understanding about surface-dynamical processes, including carrier trapping and recombination remains extremely limited. A key challenge is to selectively map such dynamic processes, a capability that is hitherto impractical by time-resolved laser techniques, which are limited by the laser’s relatively large penetration depth and consequently they record mainly bulk information. Such surface dynamics can only be mapped in real space and time by applying four-dimensional (4D) scanning ultrafast electron microscopy (S-UEM), which records snapshots of materials surfaces with nanometer spatial and sub-picosecond temporal resolutions. In this method, the secondary electron (SE) signal emitted from the sample’s surface is extremely sensitive to the surface dynamics and is detected in real time. In several unique applications, we spatially and temporally visualize the SE energy gain and loss, the charge carrier dynamics on the surface of InGaN nanowires and CdSe single crystals and its powder film. We also provide the mechanisms for the observed dynamics, which will be the foundation for future potential applications of S-UEM to a wide range of studies on material surfaces and device interfaces.

  9. Instrumental Developments for In-situ Breakdown Experiments inside a Scanning Electron Microscope

    CERN Document Server

    Muranaka, T; Leifer, K; Ziemann, V

    2011-01-01

    Electrical discharges in accelerating structures are one of the key issues limiting the performance of future high energy accelerators such as the Compact Linear Collider (CLIC). Fundamental understanding of breakdown phenomena is an indispensable part of the CLIC feasibility study. The present work concerns the experimental study of breakdown using Scanning Electron Microscopes (SEMs). A SEM gives us the opportunity to achieve high electrical gradients of 1\\,kV/$\\mu$m which corresponds to 1\\,GV/m by exciting a probe needle with a high voltage power supply and controlling the positioning of the needle with a linear piezo motor. The gap between the needle tip and the surface is controlled with sub-micron precision. A second electron microscope equipped with a Focused Ion Beam (FIB) is used to create surface corrugations and to sharpen the probe needle to a tip radius of about 50\\,nm. Moreover it is used to prepare cross sections of a voltage breakdown area in order to study the geometrical surface damages as w...

  10. Scanning Auger electron spectroscopy studies of grain-boundary segregation in Type 304 stainless steel

    International Nuclear Information System (INIS)

    Scanning Auger electron spectroscopy studies have been conducted on grain-boundary surfaces of Type 304 stainless steel that were fractured in situ. To enhance the probability of intergranular fracture, the specimens were first subjected to creep deformation for 1000 h at 7000C. A semiquantitative surface chemical composition was calculated from the peak heights of Auger electron spectra. The concentration of Cr at the fracture surface was not different from the bulk value. This indicates that the long-term heat treatment caused healing of the sensitization. The concentrations of S, C, and Si at the fracture surface were at least an order of magnitude higher than the bulk values. Chemical composition profiles obtained by ion-sputtering indicated that segregation of S, C, P, and Si occurred within a depth of several atomic monolayers from the grain-boundary surface. Mo, Mn and Cu were not detected. The concentrations of Ni and Fe are in good agreement with the bulk chemical analysis

  11. Internal composition of atmospheric dust particles from focused ion-beam scanning electron microscopy.

    Science.gov (United States)

    Conny, Joseph M

    2013-08-01

    Use of focused ion-beam scanning electron microscopy (FIB-SEM) to investigate the internal composition of atmospheric particles is demonstrated for assessing particle optical properties. In the FIB-SEM instrument equipped with an X-ray detector, a gallium-ion beam mills the particle, while the electron beam images the slice faces and energy-dispersive X-ray spectroscopy provides element maps of the particle. Differences in assessments of optical behavior based on FIB-SEM and conventional SEM were shown for five selected urban dust particles. The benefit of FIB-SEM for accurately determining the depth and size of optically important phases within particles was shown. FIB-SEM revealed that iron oxide grains left undetected by conventional SEM could potentially shift the single-scattering albedo of the particle from negative to positive radiative forcing. Analysis of a coke-like particle showed that 73% of the light-scattering inclusion went undetected with conventional SEM, causing the bulk absorption coefficient to vary by as much as 25%. Optical property calculations for particles as volume-equivalent spheres and as spheroids that approximated actual particle shapes revealed that the largest effect between conventional SEM and FIB-SEM analyses was on backscattering efficiency, in some cases varying several-fold. PMID:23763344

  12. Miniature Variable Pressure Scanning Electron Microscope for In-Situ Imaging and Chemical Analysis

    Science.gov (United States)

    Gaskin, Jessica A.; Jerman, Gregory; Gregory, Don; Sampson, Allen R.

    2012-01-01

    NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO2-rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM(Tradmark) (FEI) confirms the usefulness of lowcurrent/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.

  13. Nanogold In Situ Hybridization for Phylogenetic Identification in Geologic Samples Using Environmental Scanning Electron Microscopy

    Science.gov (United States)

    Ehrhardt, C.; Haymon, R.; Sievert, S.; Holden, P.

    2006-12-01

    Collecting phylogenetic information simultaneously with mineral textures and associations for geomicrobiological studies has always been a challenge. Recently a new type of nucleotide reporter system has been developed that utilizes small particles of nanogold (1.4 nm) covalently attached to oligonucelotide probes. Due to the small size and electron density of these nanogold reporter molecules, this in situ hybridization technique allows for the phylogenetic identification of microbial targets with a scanning electron microscope. Here we present new applications of the nanogold hybridization technique for pure cultures and natural microbial communities in a range of geologic samples including sand grains, basalt chips incubated on deep sea hydrothermal vents, and gypsum crusts sampled from a saline lake. While we do observe nonspecific binding of nanogold probes to minerals and organic compounds in geologic matrices, this can be distinguished from positive hybridization events with a spatial variety analysis. To assess the potential of nanogold hybridizations for quantitative assessments of microbial communities, fluorescent in situ hybridizations (FISH) were performed on all samples and compared to cell counts generated from nanogold hybridizations.

  14. Master curves for gas amplification in low vacuum and environmental scanning electron microscopy.

    Science.gov (United States)

    Thiel, Bradley L

    2004-02-01

    The concept of universal amplification profiles for gas cascade amplification of signals in low vacuum and environmental scanning electron microscopes is demonstrated both experimentally and theoretically using water vapor. For a given gas, cascade amplification gain profiles can be plotted onto a single master curve where the independent reduced parameter is the ratio of pressure to amplification field strength. When plotted in this fashion, both desired secondary electron and spurious background signal components fall onto respective master curves, with the amplitude being a function of anode bias only. These master curves can be described by simple Townsend Gas Capacitor equations using only two gas-specific parameters. As long as single scattering conditions apply, this approach allows for simplified, direct comparison of the gain characteristics of different gases and allows more intelligent selection of imaging conditions. The utility of treating signal amplification in this manner is demonstrated through a series of images collected under a variety of conditions, but with the ratio of pressure to amplification field strength kept constant. In practice, the range of operational parameter space in which this description can be applied to imaging is limited, as images typically have a mixture of secondary and backscattered contributions.

  15. Influence of acceleration voltage on scanning electron microscopy of human blood platelets.

    Science.gov (United States)

    Pretorius, E

    2010-03-01

    Scanning electron microscopy (SEM) is used to view a variety of surface structures, molecules, or nanoparticles of different materials, ranging from metals, dental and medical instruments, and chemistry (e.g. polymer analysis) to biological material. Traditionally, the operating conditions of the SEM are very important in the material sciences, particularly the acceleration voltage. However, in biological sciences, it is not typically seen as an important parameter. Acceleration voltage allows electrons to penetrate the sample; thus, the higher the acceleration voltage the more penetration into the sample will occur. As a result, ultrastructural information from deeper layers will interfere with the actual surface morphology that is seen. Therefore, ultimately, if acceleration voltage is lower, a better quality of the surface molecules and structures will be produced. However, in biological sciences, this is an area that is not well-documented. Typically, acceleration voltages of between 5 and 20 kV are used. This manuscript investigates the influence of acceleration voltages ranging from 5 kV to as low as 300 V, by studying surface ultrastructure of a human platelet aggregate. It is concluded that, especially at higher magnifications, much more surface detail is visible in biological samples when using an acceleration voltage between 2 kV and 300 V.

  16. Nano-Tomography of Porous Geological Materials Using Focused Ion Beam-Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-10-01

    Full Text Available Tomographic analysis using focused ion beam-scanning electron microscopy (FIB-SEM provides three-dimensional information about solid materials with a resolution of a few nanometres and thus bridges the gap between X-ray and transmission electron microscopic tomography techniques. This contribution serves as an introduction and overview of FIB-SEM tomography applied to porous materials. Using two different porous Earth materials, a diatomite specimen, and an experimentally produced amorphous silica layer on olivine, we discuss the experimental setup of FIB-SEM tomography. We then focus on image processing procedures, including image alignment, correction, and segmentation to finally result in a three-dimensional, quantified pore network representation of the two example materials. To each image processing step we consider potential issues, such as imaging the back of pore walls, and the generation of image artefacts through the application of processing algorithms. We conclude that there is no single image processing recipe; processing steps need to be decided on a case-by-case study.

  17. A versatile LabVIEW and FPGA-based scanned probe microscope for in-operando electronic device characterization

    OpenAIRE

    Berger, Andrew J.; Page, Michael R.; Jacob, Jan; Young, Justin R.; Lewis, Jim; Wenzel, Lothar; Bhallamudi, Vidya P.; Johnston-Halperin, Ezekiel; Pelekhov, Denis V.; Hammel, P. Chris

    2014-01-01

    Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In-operando characterization of such devices by scanned probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanned probe microscope (SPM) which is capable of both standard force imaging (atomic, magnet...

  18. Aberration-corrected scanning transmission electron microscopy for complex transition metal oxides

    Science.gov (United States)

    Qing-Hua, Zhang; Dong-Dong, Xiao; Lin, Gu

    2016-06-01

    Lattice, charge, orbital, and spin are the four fundamental degrees of freedom in condensed matter, of which the interactive coupling derives tremendous novel physical phenomena, such as high-temperature superconductivity (high-T c SC) and colossal magnetoresistance (CMR) in strongly correlated electronic system. Direct experimental observation of these freedoms is essential to understanding the structure-property relationship and the physics behind it, and also indispensable for designing new materials and devices. Scanning transmission electron microscopy (STEM) integrating multiple techniques of structure imaging and spectrum analysis, is a comprehensive platform for providing structural, chemical and electronic information of materials with a high spatial resolution. Benefiting from the development of aberration correctors, STEM has taken a big breakthrough towards sub-angstrom resolution in last decade and always steps forward to improve the capability of material characterization; many improvements have been achieved in recent years, thereby giving an in-depth insight into material research. Here, we present a brief review of the recent advances of STEM by some representative examples of perovskite transition metal oxides; atomic-scale mapping of ferroelectric polarization, octahedral distortions and rotations, valence state, coordination and spin ordering are presented. We expect that this brief introduction about the current capability of STEM could facilitate the understanding of the relationship between functional properties and these fundamental degrees of freedom in complex oxides. Project supported by the National Key Basic Research Project, China (Grant No. 2014CB921002), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB07030200), and the National Natural Science Foundation of China (Grant Nos. 51522212 and 51421002).

  19. Analysis of environmental particles by atomic force microscopy, scanning and transmission electron microscopy.

    Science.gov (United States)

    Mavrocordatos, D; Pronk, W; Boiler, M

    2004-01-01

    Due to their large specific surface and their abundance, micro and nano particles play an important role in the transport of micropollutants in the environment. Natural particles are usually composed of a mixture of inorganic amorphous or crystalline material (mainly FeOOH, Fe(x)Oy, Mn(x)Oy and clays) and organic material (humics and polysaccharides). They all tend to occur as very small particles (1-1,000 nm in diameter). Most natural amorphous particles are unstable and tend to transform with time towards more crystalline forms, either by aging or possibly, by dissolution and re-crystallization. Such transformations affect the fate of sorbed micropollutants and the scavenging properties are therefore changed. As these entities are sensitive to dehydration (aggregation, changes in the morphology), it is highly important to observe their morphology in their natural environment and understand their composition at the scale of the individual particles. Also for the understanding and optimization of water treatment technologies, the knowledge of the occurrence and behavior of nano-particles is of high importance. Some of the possible particle analysis methods are presented: aggregation processes, biomineralization, bacterial adhesion, biofilms in freshwaters, ferrihydrite as heavy metals remover from storm water. These examples demonstrate the capabilities and focus of the microscopes. Atomic Force Microscopy (AFM) allows to analyze the particles in their own environment, meaning in air or in the water. Thus, native aspects of particles can be observed. As well, forces of interactions between particles or between particles and other surfaces such as membranes will be highly valuable data. Scanning Electron Microscopy (SEM) and for higher lateral resolution, Transmission Electron Microscopy (TEM) allow measurement of the morphology and composition. Especially, TEM coupled with Electron Energy Loss Spectroscopy (TEM-EELS) is a powerful technique for elemental analysis

  20. Micro-four-point probes in a UHV scanning electron microscope for in-situ surface-conductivity measurements

    DEFF Research Database (Denmark)

    Shiraki, I.; Nagao, T.; Hasegawa, S.;

    2000-01-01

    For in-situ measurements of surface conductivity in ultrahigh vacuum (UHV), we have installed micro-four-point probes (probe spacings down to 4 mum) in a UHV scanning electron microscope (SEM) combined with scanning reflection-high-energy electron diffraction (RHEED). With the aid of piezoactuators...... for precise positioning of the probes, local conductivity of selected surface domains of well-defined superstructures could be measured during SEM and RHEED observations. It was found that the surface sensitivity of the conductivity measurements was enhanced by reducing the probe spacing, enabling...... the unambiguous detection of surface-state conductivity and the influence of surface defects on the electrical conduction....

  1. Further description of Cruzia tentaculata (Rudolphi, 1819) Travassos, 1917 (Nematoda: Cruzidae) by light and scanning electron microscopy.

    Science.gov (United States)

    Adnet, F A O; Anjos, D H S; Menezes-Oliveira, A; Lanfredi, R M

    2009-04-01

    Species of Cruzia are parasites of the large intestine of marsupials, reptiles, amphibians, and mammalians. Cruzia tentaculata specimens were collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Colombia (new geographical record) and from Brazil and analyzed by light and scanning electron microscopy. The morphology of males and females by light microscopy corroborated most of the previous description and the ultrastructure by scanning electron microscopy evidence: the topography of the cuticle, deirids, amphids, phasmids in both sexes, a pair of papillae near the vulva opening, and the number and location of male caudal papillae, adding new features for species identification only observed by this technique. PMID:19130086

  2. Validation of cell-free culture using scanning electron microscopy (SEM) and gene expression studies.

    Science.gov (United States)

    Yang, R; Elankumaran, Y; Hijjawi, N; Ryan, U

    2015-06-01

    A cell-free culture system for Cryptosporidium parvum was analysed using scanning electron microscopy (SEM) to characterise life cycle stages and compare gene expression in cell-free culture and cell culture using HCT-8 cells. Cryptosporidium parvum samples were harvested at 2 h, 8 h, 14 h, 26 h, 50 h, 74 h, 98 h, 122 h and 170 h, chemically fixed and specimens were observed using a Zeiss 1555 scanning electron microscope. The presence of sporozoites, trophozoites and type I merozoites were identified by SEM. Gene expression in cell culture and cell-free culture was studied using reverse transcriptase quantitative PCR (RT-qPCR) of the sporozoite surface antigen protein (cp15), the glycoprotein 900 (gp900), the Cryptosporidium oocyst wall protein (COWP) and 18S ribosomal RNA (rRNA) genes in both cell free and conventional cell culture. In cell culture, cp15 expression peaked at 74 h, gp900 expression peaked at 74 h and 98 h and COWP expression peaked at 50 h. In cell-free culture, CP15 expression peaked at 98 h, gp900 expression peaked at 74 h and COWP expression peaked at 122 h. The present study is the first to compare gene expression of C. parvum in cell culture and cell-free culture and to characterise life cycle stages of C. parvum in cell-free culture using SEM. Findings from this study showed that gene expression patterns in cell culture and cell-free culture were similar but in cell-free culture, gene expression was delayed for CP15 and COWP in cell free culture compared with the cell culture system and was lower. Although three life cycle stageswere conclusively identified, improvements in SEM methodology should lead to the detection of more life cycle stages.

  3. Role of scanning electron microscopy in identifying drugs used in medical practice.

    Science.gov (United States)

    Fazil Marickar, Y M; Sylaja, N; Koshy, Peter

    2009-10-01

    Several plant preparations are administered for treatment of stone disease without scientific basis. This paper presents the results of in vitro and animal experimental studies using scanning electron microscopy (SEM) in the identification of the therapeutic properties of trial drugs in medicine. In the first set of the study, urinary crystals namely calcium oxalate monohydrate and calcium oxalate dehydrate were grown in six sets of Hane's tubes in silica gel medium. Trial drugs namely scoparia dulcis Lynn, musa sapiens and dolicos biflorus were incorporated in the gel medium to identify the dopant effect of the trial drugs on the size and extent of crystal column growth. The changes in morphology of crystals were studied using SEM. In the second set, six male Wistar rats each were calculogenised by administering sodium oxalate and ethylene glycol and diabetised using streptozotocin. The SEM changes of calculogenisation were studied. The rats were administered trial drugs before calculogenisation or after. The kidneys of the rats studied under the scanning electron microscope showed changes in tissue morphology and crystal deposition produced by calculogenisation and alterations produced by addition of trial drugs. The trial drugs produced changes in the pattern of crystal growth and in the crystal morphology of both calcium oxalate monohydrate and calcium oxalate dihydrate grown in vitro. Elemental distribution analysis showed that the crystal purity was not altered by the trial drugs. Scoparia dulcis Lynn was found to be the most effective anticalculogenic agent. Musa sapiens and dolicos biflorus were found to have no significant effect in inhibiting crystal growth. The kidneys of rats on calculogenisation showed different grades of crystals in the glomerulus and interstitial tissues, extrusion of the crystals into the tubular lumen, collodisation and tissue inflammatory cell infiltration. Scoparia dulcis Lynn exhibited maximum protector effect against the

  4. Scanning electron microscopic, transmission electron microscopic, and confocal laser scanning microscopic observation of fibroblasts cultured on microgrooved surfaces of bulk titanium substrata

    NARCIS (Netherlands)

    Braber, den E.T.; Jansen, H.V.; Boer, de M.J.; Croes, H.J.E.; Elwenspoek, M.; Ginsel, L.A.; Jansen, J.A.

    1998-01-01

    During this study, microtechnology and plasma etching were used to produce gratings 1.0 (TiD01), 2.0 (TiD02), 5.0 (TiD05), and 10.0 µm wide (TiD10) into commercially pure titanium wafers. After incubation of rat dermal fibroblast (RDFs) on these surfaces for 3 days, the cells were observed with scan

  5. In vitro comparison of epidural bacteria filters permeability and screening scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Aysin Sener

    2015-12-01

    Full Text Available BACKGROUND AND OBJECTIVES: Epidural catheter bacteria filters are barriers in the patient-controlled analgesia/anaesthesia for preventing contamination at the epidural insertion site. The efficiency of these filters varies according to pore sizes and materials. METHOD: The bacterial adhesion capability of the two filters was measured in vitro experiment. Adhesion capacities for standard Staphylococcus aureus (ATCC 25923 and Pseudomonas aeruginosa (ATCC 27853 strains of the two different filters (Portex and Rusch which have the same pore size were examined. Bacterial suspension of 0.5 Mc Farland was placed in the patient-controlled analgesia pump, was filtered at a speed of 5 mL/h. in continuous infusion for 48 h and accumulated in bottle. The two filters were compared with colony counts of bacteria in the filters and bottles. At the same time, the filters and adhered bacteria were monitored by scanning electron microscope. RESULTS: Electron microscopic examination of filters showed that the Portex filter had a granular and the Rusch filter fibrillary structure. Colony counting from the catheter and bottle showed that both of the filters have significant bacterial adhesion capability (p < 0.001. After the bacteria suspension infusion, colony countings showed that the Portex filter was more efficient (p < 0.001. There was not any difference between S. aureus and P. aeruginosa bacteria adhesion. In the SEM monitoring after the infusion, it was physically shown that the bacteria were adhered efficiently by both of the filters. CONCLUSION: The granular structured filter was found statistically and significantly more successful than the fibrial. Although the pore sizes of the filters were same - of which structural differences shown by SEM were the same - it would not be right to attribute the changes in the efficiencies to only structural differences. Using microbiological and physical proofs with regard to efficiency at the same time has been

  6. The importance of scanning electron microscopy (sem in taxonomy and morphology of Chironomidae (Diptera

    Directory of Open Access Journals (Sweden)

    Andrzej Kownacki

    2015-07-01

    Full Text Available The paper reports on the value of scanning electron microscopy (SEM in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more precise picture of the body structure of Chironomidae can be revealed. It allows researchers to explain inconsistencies in the existing descriptions of species. Another advantage of the SEM method is obtaining spatial images of the body and organs of Chironomidae. However, the SEM method also has some limitations. The main problem is dirt or debris (e.g. algae, mud, secretions, mucus, bacteria, etc., which often settles on the external surface of structures, especially those which are uneven or covered with hair. The dirt should be removed after collection of chironomid material because if left in place it can become chemically fixed to various surfaces. It unnecessarily remains at the surface and final microscopic images may contain artifacts that obscure chironomid structures being investigated. In this way many details of the surface are thus unreadable. The results reported here indicate that SEM examination helps us to identify new morphological features and details that will facilitate the identification of species of Chironomidae and may help to clarify the function of various parts of the body. Fast development of electron microscope technique allows us to learn more about structure of different organisms.

  7. An optimized methodology to analyze biopolymer capsules by environmental scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Conforto, Egle, E-mail: egle.conforto@univ-lr.fr [LaSIE UMR 7356 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle (France); Joguet, Nicolas [Equipe Approches Moléculaires Environnement-Santé, LIENSs, UMR 7266 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle (France); Buisson, Pierre [INNOV' IA, 4 rue Samuel Champlain, Z.I. Chef de Baie, 17000 La Rochelle (France); Vendeville, Jean-Eudes; Chaigneau, Carine [IDCAPS, filiale R and D INNOV' IA, 4 rue Samuel Champlain, Z.I. Chef de Baie, 17000 La Rochelle (France); Maugard, Thierry [Equipe Approches Moléculaires Environnement-Santé, LIENSs, UMR 7266 CNRS-ULR, Université de La Rochelle, UFR Sciences, Avenue Michel Crepeau, 17042 La Rochelle (France)

    2015-02-01

    The aim of this paper is to describe an optimized methodology to study the surface characteristics and internal structure of biopolymer capsules using scanning electron microscopy (SEM) in environmental mode. The main advantage of this methodology is that no preparation is required and, significantly, no metallic coverage is deposited on the surface of the specimen, thus preserving the original capsule shape and its surface morphology. This avoids introducing preparation artefacts which could modify the capsule surface and mask information concerning important feature like porosities or roughness. Using this method gelatin and mainly fatty coatings, difficult to be analyzed by standard SEM technique, unambiguously show fine details of their surface morphology without damage. Furthermore, chemical contrast is preserved in backscattered electron images of unprepared samples, allowing visualizing the internal organization of the capsule, the quality of the envelope, etc.… This study provides pointers on how to obtain optimal conditions for the analysis of biological or sensitive material, as this is not always studied using appropriate techniques. A reliable evaluation of the parameters used in capsule elaboration for research and industrial applications, as well as that of capsule functionality is provided by this methodology, which is essential for the technological progress in this domain. - Highlights: • We optimized a methodology using ESEM to analyze biopolymer capsules. • This methodology allows analyzing original surface samples without any preparation. • No preparation artefact are introduced which would mask important surface details. • Morphological details and chemical contrast from the original surface are preserved. • Capsule shape, volume, surface roughness and coating quality were reliably evaluated.

  8. Scanning electron microscopy of the surfaces of ion implanted SiC

    Energy Technology Data Exchange (ETDEWEB)

    Malherbe, Johan B., E-mail: johan.malherbe@up.ac.za [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Berg, N.G. van der; Kuhudzai, R.J.; Hlatshwayo, T.T.; Thabethe, T.T.; Odutemowo, O.S.; Theron, C.C.; Friedland, E. [Department of Physics, University of Pretoria, Pretoria 0002 (South Africa); Botha, A.J. [Laboratory for Microscopy & Microanalysis, University of Pretoria, Pretoria 0002 (South Africa); Wendler, E. [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, 07743 Jena (Germany)

    2015-07-01

    This paper gives a brief review of radiation damage caused by particle (ions and neutrons) bombardment in SiC at different temperatures, and its annealing, with an expanded discussion on the effects occurring on the surface. The surface effects were observed using SEM (scanning electron microscopy) with an in-lens detector and EBSD (electron backscatter diffraction). Two substrates were used, viz. single crystalline 6H-SiC wafers and polycrystalline SiC, where the majority of the crystallites were 3C-SiC. The surface modification of the SiC samples by 360 keV ion bombardment was studied at temperatures below (i.e. room temperature), just at (i.e. 350 °C), or above (i.e. 600 °C) the critical temperature for amorphization of SiC. For bombardment at a temperature at about the critical temperature an extra step, viz. post-bombardment annealing, was needed to ascertain the microstructure of bombarded layer. Another aspect investigated was the effect of annealing of samples with an ion bombardment-induced amorphous layer on a 6H-SiC substrate. SEM could detect that this layer started to crystalize at 900 °C. The resulting topography exhibited a dependence on the ion species. EBSD showed that the crystallites forming in the amorphized layer were 3C-SiC and not 6H-SiC as the substrate. The investigations also pointed out the behaviour of the epitaxial regrowth of the amorphous layer from the 6H-SiC interface.

  9. Characterizing deformed ultrafine-grained and nanocrystalline materials using transmission Kikuchi diffraction in a scanning electron microscope

    International Nuclear Information System (INIS)

    Graphical abstract: -- Abstract: The recent development of transmission Kikuchi diffraction (TKD) in a scanning electron microscope enables fast, automated orientation mapping of electron transparent samples using standard electron backscatter diffraction (EBSD) hardware. TKD in a scanning electron microscope has significantly better spatial resolution than conventional EBSD, enabling routine characterization of nanocrystalline materials and allowing effective measurement of samples that have undergone severe plastic deformation. Combining TKD with energy dispersive X-ray spectroscopy (EDS) provides complementary chemical information, while a standard forescatter detector system below the EBSD detector can be used to generate dark field and oriented dark field images. Here we illustrate the application of this exciting new approach to a range of deformed, ultrafine grained and nanocrystalline samples, including duplex stainless steel, nanocrystalline copper and highly deformed titanium and nickel–cobalt. The results show that TKD combined with EDS is a highly effective and widely accessible tool for measuring key microstructural parameters at resolutions that are inaccessible using conventional EBSD

  10. Exposure of 895i resist using a vector scan Gaussian electron-beam lithography system

    Science.gov (United States)

    Kugelmass, Sheldon M.; Mitchell, Joseph; Poreda, John T.

    1996-07-01

    A positive tone, optical resist, OCG 895i, was exposed using the Lepton EBES4, a vector scan Gaussian electron beam lithography system. Proximity Effect Corrections (PEC) were applied via dose modulation on a figure-by-figure basis at write time. Test patterns were corrected using a simple "framing" technique that is the first step in a phased implementation of a complete PEC solution. Figures were separated into bulk and frame regions, with different doses being applied to each. The corrected pattern was exposed in a single pass using a single pattern file. The mask lithography quality of these exposures was evaluated by measurement of CD Linearity, Line Edge Roughness and CD X-Y Bias. A throughput study was conducted to determine the impact of using lower sensitivity resists on mask write times. A series of test jobs was written at conditions consistent with exposure doses of 2 and 8 μC/cm2. This 4X dose increase resulted in a write times that were only 1 .5X longer. A 64 MBit DRAM pattern, prepared with framing, with 50 nm address was exposed at 8 μC/cm2 in 3 hr 35 min.

  11. Correlation between auditory brainstem recordings and morphology as seen through the scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Hultcrantz, M.

    1988-09-01

    Pregnant CBA/CBA mice were exposed to 0.5, 1 and 2 Grey (Gy), (1 Gy = 100 rad) in single doses with whole body gamma-irradiation on the 12th, 13th and 16th gestational days, respectively. The animals were tested at an age of one month for vestibular and cochlear function. Thereafter the inner ears were analyzed with scanning electron microscopy. A morphological analysis with cytocochleograms was performed. Morphological changes in the vestibular part showed gross malformations in the cristae ampullares. Hair cells of type I seemed to be more severely changed than hair cells type II. The macula utriculi also showed malformations of the otoconia. All these changes were more pronounced when the irradiation was given early during pregnancy and with the highest doses used, except the otoconia which were more injured when irradiated day 16 of gestation. No disturbances of the equilibrium reflexes were noted. In the cochlea a dose-dependent, time-related damage pattern was demonstrated with pathological changes of outer (OHC) and inner (IHC) hair cells. When tested electrophysiologically for auditory function with auditory brainstem recordings (ABR), elevated thresholds were revealed different in shape depending on when during pregnancy irradiation took place. A good correlation existed between the morphological changes as seen in the cytocochleograms and the functional changes documented with the ABR.

  12. Analysis of femtosecond laser assisted capsulotomy cutting edges and manual capsulorhexis using environmental scanning electron microscopy.

    Science.gov (United States)

    Serrao, Sebastiano; Lombardo, Giuseppe; Desiderio, Giovanni; Buratto, Lucio; Schiano-Lomoriello, Domenico; Pileri, Marco; Lombardo, Marco

    2014-01-01

    Purpose. To investigate the structure and irregularity of the capsulotomy cutting edges created by two femtosecond (FS) laser platforms in comparison with manual continuous circular capsulorhexis (CCC) using environmental scanning electron microscopy (eSEM). Methods. Ten anterior capsulotomies were obtained using two different FS laser cataract platforms (LenSx, n = 5, and Victus, n = 5). In addition, five manual CCC (n = 5) were obtained using a rhexis forceps. The specimens were imaged by eSEM (FEI Quanta 400, OR, USA). Objective metrics, which included the arithmetic mean deviation of the surface (Sa) and the root-mean-square deviation of the surface (Sq), were used to evaluate the irregularity of both the FS laser capsulotomies and the manual CCC cutting edges. Results. Several microirregularities were shown across the FS laser capsulotomy cutting edges. The edges of manually torn capsules were shown, by comparison of Sa and Sq values, to be smoother (P laser capsulotomy edges. Conclusions. Work is needed to understand whether the FS laser capsulotomy edge microirregularities, not seen in manual CCC, may act as focal points for the concentration of stress that would increase the risk of capsular tear during phacoemulsification as recently reported in the literature.

  13. The Effect of Fragaria vesca Extract on Smear Layer Removal: A Scanning Electron Microscopic Evaluation

    Science.gov (United States)

    Davoudi, Amin; Razavi, Sayed Alireza; Mosaddeghmehrjardi, Mohammad Hossein; Tabrizizadeh, Mehdi

    2015-01-01

    Introduction: Successful endodontic treatment depends on elimination of the microorganisms through chemomechanical debridement. The aim of this in vitro study was to evaluate the effectiveness of Fragaria vesca (wild strawberry) extract (FVE) on the removal of smear layer (SL). Methods and Materials: In this analytical-observational study, 40 extracted mandibular and maxillary human teeth were selected. After canal preparation with standard step-back technique, the teeth were randomly divided into 4 groups according to the irrigation solution: saline (negative control), 5.25% NaOCl+EDTA (positive control), FVE and FVE+EDTA. The teeth were split longitudinally so that scanning electron microscopy (SEM) photomicrographs could be taken to evaluate the amount of remnant SL in coronal, middle and apical thirds. The data were analyzed statistically by the Kruskal-Wallis and Mann Whitney U tests and the level of significance was set at 0.05. Results: Significant differences were found among the groups (P<0.001). The use of NaOCl+EDTA was the most effective regimen for removing the SL followed by FVE+EDTA. FVE alone was significantly more effective than saline (P<0.001). Conclusion: FVE with and without EDTA could effectively remove the smear layer; however, compared to NaOCl group it was less effective. PMID:26526069

  14. Opisthorchiasis-associated biliary stones:Light and scanning electron microscopic study

    Institute of Scientific and Technical Information of China (English)

    Banchob Sripa; Pipatphong Kanla; Poonsiri Sinawat; Melissa R. Haswell-Elkins

    2004-01-01

    AIM: Biliary stones are frequentty encountered in areas endemic for opisthorchiasis in Thailand. The present study was to describe the prevalence and pathogenesis of these stones.METHODS: Gallstones and/or common bile duct stones and bile specimens from 113 consecutive cholecystectomies were included. Bile samples, including sludge and/or microcalculi, were examined for Opisthorchis viverrini eggs,calcium and bilirubin. The stones were also processed for scanning electron microscopic (SEM) study.RESULTS: Of the 113 cases, 82 had pigment stones, while one had cholesterol stones. The other 30 cases had no stones. Most of the stone cases (76%, 63/83) had multiple stones, while the remainder had a single stone. Stones were more frequently observed in females. Bile examination was positive for O. viverrini eggs in 50% of the cases studied. Aggregates of calcium bilirubinate precipitates were observed in all cases with sludge. Deposition of calcium bilirubinate on the eggshell was visualized by special staining. A SEM study demonstrated the presence of the parasite eggs in the stones. Numerous crystals,morphologically consistent with calcium derivatives and cholesterol precipitates, were seen.CONCLUSION: Northeast Thailand has a high prevalence of pigment stones, as observed at the cholecystectomy, and liver fluke infestation seems involved in the pathogenesis of stone formation.

  15. Scanning electron microscopic study of human neuroblastoma cells affected with Naegleria fowleri Thai strains.

    Science.gov (United States)

    Tiewcharoen, Supathra; Rabablert, Jundee; Chetanachan, Pruksawan; Junnu, Virach; Worawirounwong, Dusit; Malainual, Nat

    2008-10-01

    In order to understand the pathogenesis of Naegleria fowleri in primary amoebic meningoencephalitis, the human neuroblastoma (SK-N-MC) and African green monkey kidney (Vero) cells were studied in vitro. Amoeba suspension in cell-culture medium was added to the confluent monolayer of SK-N-MC and Vero cells. The cytopathic activity of N. fowleri trophozoites in co-culture system was elucidated by scanning electron microscope at 3, 6, 9, 12, and 24 h. Two strains of N. fowleri displayed well-organized vigorous pseudopods in Nelson's medium at 37 degrees C. In co-culture, the target monolayer cells were damaged by two mechanisms, phagocytosis by vigorous pseudopods and engulfment by sucker-like apparatus. N. fowleri trophozoites produced amoebostomes only in co-culture with SK-N-MC cells. In contrast, we could not find such apparatus in the co-culture with Vero cells. The complete destruction time (100%) at 1:1 amoeba/cells ratio of SK-N-MC cells (1 day) was shorter than the Vero cells (12 days). In conclusion, SK-N-MC cells were confirmed to be a target model for studying neuropathogenesis of primary amoebic meningoencephalitis.

  16. Prevalence and Scanning Electron Microscopic Identification of Anoplocephalid Cestodes among Small Ruminants in Senegal

    Science.gov (United States)

    Yanagida, Tetsuya; Ba, Cheikh Tidiane; Marchand, Bernard

    2016-01-01

    This study was undertaken to determine the prevalence of anoplocephalid cestodes in sheep and goats in Senegal. Intestines of 462 sheep and 48 goats were examined; 47.4% of sheep and 6.2% of goats were infected. The species identified and their prevalence were, among sheep, Avitellina centripunctata 38.7%, Moniezia expansa 15.4%, Stilesia globipunctata 16.7%, and Thysaniezia ovilla 0.4%. Among goats, they were M. expansa 6.2% and T. ovilla 2.1%. The prevalence of all species was not statistically different between dry and rainy seasons. The infections were single or multiple. Indeed, 56.2% of sheep were infected by a single species, 37.4% by two species, and 6.4% by three species. For goats, 66.7% were infected by M. expansa and 33.3% by both M. expansa and T. ovilla. Scanning electron microscopic (SEM) observations of tapeworms show the general diagnosis characters of these species. PMID:27597893

  17. Examination of explanted polyurethane pacemaker leads using the scanning electron microscope.

    Science.gov (United States)

    Beyersdorf, F; Kreuzer, J; Schmidts, L; Satter, P

    1985-07-01

    Since 1978, 2,365 polyurethane (PU) insulated cardiac pacing leads were implanted transvenously at our institution. To date, there have been no insulation failures in those leads. Thirty-seven PU leads were explanted, mainly for exit block, and 28 of these were investigated using the scanning electron microscope. We found a homogeneous distribution of surface changes in all lead segments in 56% of the 28 examined. These changes were more pronounced at the ligature site; severe surface cracking was noticed in 21%, with the deepest crack being 40 micron (average range of 10-15 micron). There appeared to be no time-dependency of the surface changes as indicated by regression analysis (r = 0.32, p greater than 0.05). The ultimate severity and outcome of this degradation process in the leads reported in this study will only be known in the future after longer use. We conclude that excess stress must be avoided during the implantation procedure and that careful surveillance is necessary. PMID:2410883

  18. Scanning tunneling microscopy and inelastic electron tunneling spectroscopy studies of methyl isocyanide adsorbed on Pt(111)

    International Nuclear Information System (INIS)

    A low-temperature scanning tunneling microscope (STM) was used to investigate the adsorption state of a single methyl isocyanide (MeNC) molecule on the Pt(111) surface at 4.7 K. We found that MeNC was resolved as a round-shaped protrusion in the STM image. The STM image of paired MeNC is highly protruded in comparison with that of isolated MeNC due to the charge transfer from Pt to MeNC. Inelastic electron tunneling spectroscopy with the STM system (STM-IETS) was also employed in order to reveal the adsorption state of individual MeNC molecules on Pt(111). The STM-IETS spectrum of MeNC exhibits peaks at 8, 48 and 375 mV. Referring to the vibrational spectra reported previously, we assigned these peaks to the frustrated translation mode, PtC stretching mode and CH3 stretching mode, respectively. The absence of other vibrational modes could be due to a reduction of the elastic tunneling current.

  19. SCANNING ELECTRON MICROSCOPY OF THE RAT ADRENAL GLAND AFTER SURGICAL LASER EXPOSURE

    Directory of Open Access Journals (Sweden)

    K. G. Kemoklidze

    2016-01-01

    Full Text Available Aim. We studied via low vacuum scanning electron microscopy the effects of a surgical laser exposure to adrenal glands and results of regeneration processes after. Materials and methods.Purpose of this work is modeling of effects of the removal with a surgical laser a pathological focus in the adrenal glands. For this Wistar male rat (n = 19 adrenal glands were researched without the laser exposure, immediately after it and 1 month later. Results. Immediately after exposure occurs laser ablation crater with rough edges and melted surface penetrated by equidistant pores, which are footprints of blood vessels. Beneath of the surface are numerous vaporizationbubbles. Around the crater, the surface wrinkles and sags due to decreased ability to retain water. 1 month after the laser damage, the affected area tightened by a scar. Its coarse bundles of collagen fibers braid shapeless lumps of coal and caverns. Tissues with normal appearance are close to the scar, both outside and inside of the organ. The wrinkling and the sagging are absent. The undamaged organ part has retained the previous shape, without hypertrophies. The damaged part has shrunk. The nature of the regeneration processes indicates a low probability of a relapse after the destruction of a pathological focus via the surgical laser exposure.

  20. Comparison of different retreatment techniques and root canal sealers: a scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Neslihan Simsek

    2014-05-01

    Full Text Available The aim of this study was to evaluate the effectiveness of two retreatment techniques, in terms of the operating time and scanning electron microscopy (SEM results, in removing three different root canal sealers from root canals that were previously filled with gutta-percha. Sixty extracted single-rooted human premolars were divided into three groups and filled with iRoot SP, MM Seal, and AH Plus sealers, along with gutta-percha, through a lateral compaction technique. Root canal fillings of the samples were removed by ESI ultrasonic tips or R-Endo files. The time to reach the working length was recorded. Longitudinally sectioned samples were examined under SEM magnification. Each picture was evaluated in terms of the residual debris. Data were statistically analyzed with the Kruskall-Wallis test. No statistically significant differences were found in terms of operating time (p>0.05. Significant differences in the number of debris-free dentinal tubules were found among the root canal thirds, but this finding was not influenced by the experimental group (p < 0.05. Resin sealer tags were observed inside the dentinal tubules in the MM Seal group. Under the conditions of this study, it may be established that there was no difference among the sealers and retreatment techniques.

  1. Antioxidant mix: A novel pulpotomy medicament: A scanning electron microscopy evaluation

    Directory of Open Access Journals (Sweden)

    M Ajay Reddy

    2014-01-01

    Full Text Available Aim: This study aims to evaluate the clinical, radiographic, and histological success rate of antioxidant mix as a new pulpotomy agent for primary teeth. Settings and Design: Commercially available antioxidants, namely Antioxidants plus trace elements (OXIn-Xt tm , India were used. Materials and Methods: This prospective study was carried out on 36 primary molar teeth in 32 children, with age that ranged from 6 to 9 years. Regular conventional pulpotomy procedure followed by placement of antioxidant mix over the radicular orifice was done. Recall was scheduled for 3, 6, and 9 months, respectively, after treatment. Results: Thirty-six pulpotomized primary molars were available for follow-up evaluations. Scanning electron microscopy analysis of samples showing convex shaped hard tissue barrier formation may be proof of the role of antioxidant material in localization and direction and morphology of the hard tissue barrier. One tooth which presented with pain was assessed as unsuccessful. Conclusion: Quite promising clinical, radiographic, and histological results of antioxidants in the present study shows their potential to be an ideal pulpotomy agent.

  2. Comparison between the effect of Lawsonia inermis and flubendazole on Strongyloides species using scanning electron microscopy.

    Science.gov (United States)

    Ismail, Khadiga Ahmed; Ibrahim, Ayman Nabil; Ahmed, Mona Abdel-Fattah; Hetta, Mona Hafez

    2016-06-01

    Strongyloides species is a helminth of worldwide distribution primarily in tropical and subtropical regions. It is the only soil-transmitted helminth with the ability for autoinfection so; it may lead to severe systemic manifestations especially in immunosuppressed patients. Chemotherapy is currently considered the best therapeutic option for strongyloidiasis but some drugs are expensive and others have side effects as nausea, diarrhea and headache. Strongyloides larva is resistant to most chemical agents so, search for plant extracts may provide other effective but less expensive treatment. Lawsonia inermis Linn, popularly known as Henna, has been proven to have antihelminthic, antibacterial and antifungal properties. The current study was carried out to evaluate the efficacy of Lawsonia inermis on Strongyloides spp. In vitro using scanning electron microscopy. Fifty Strongyloides species. larvae and free living females were incubated with different concentrations of Lawsonia (1, 10, 100 mg/ml), for different incubation periods (24, 48, 72 and 96 h) in comparison to the same concentrations of flubendazole at the same different time points. The results showed that Lawsonia inermis in a concentration of 10 mg/ml incubated with Strongyloides spp. female for 24 h affected the parasite cuticular surface in the form of transverse and longitudinal fissures and transverse depression in comparison to no cuticular change with flubendazole (100 mg/ml). This suggests that Lawsonia inermis may be a promising phytotherapeutic agent for strongyloidiasis. PMID:27413314

  3. ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY (ESEM OF Morinda citrifolia L. (Rubiaceae COLLETERS

    Directory of Open Access Journals (Sweden)

    Sergimar Kennedy de Paiva PINHEIRO

    2015-12-01

    Full Text Available This study describes the colleters of Morinda citrifolia L. (Rubiaceae by using environmental scanning electron microscopy (ESEM and energy dispersive x-ray spectroscopy (EDS. Two different developmental stages were characterized as well as the chemical composition of secretion. Colleters are secretory structures that produce mucilage protecting the meristems and leaf primordia against desiccation and/or pathogens. Although these secretory structures are common on Rubiaceae, the results reported here is to the best of our knowledge the first record of colleters on Morinda genus. Colleters are present at the stipule adaxial surface, distributed in lines. These secretory structures are standard type and have no base constriction, differently from all studied species until now. In order to better understand the colleters structure and secretion, two phases were distinguished: a secretory phase and a senescence one. On secretory phase standard type colleters were visualized between leaf primordia and stipule, emerge on secretion. They present smooth surface, however was also possible to observe the contours of secretory cells anticlinal walls. In senescent phase colleters morphology was alternated exhibiting rough surface and blunt to point tips. The surface was rough and on stipule sections was possible to observe idioblasts with raphides bundles. The secretion process of M. citrifolia colleters occurs with the disruption of cuticle and the chemical elements are mostly dominated by carbon and oxygen.

  4. Seasonal variations in the heterologous binding of viscacha spermatozoa. A scanning electron microscope study.

    Science.gov (United States)

    Merlo, Claudia Aguilera; Muñoz, Estela; Dominguez, Susana; Fóscolo, Mabel; Scardapane, Luis; de Rosas, Juan Carlos

    2005-12-01

    Seasonal changes in the reproductive activity of the adult male viscacha (Lagostomus maximus maximus) were investigated during the annual reproductive cycle. Assays of heterologous in vitro binding between compatible gametes were used to evaluate the ability of viscacha spermatozoa to achieve primary binding during its annual reproductive cycle. Sperm were collected by mincing cauda epididymis in HECM-3 medium and the sperm concentration and motility were evaluated. Cumulus-free and zona-free oocytes obtained from superovulated hamsters were inseminated in vitro with capacitated sperm suspensions, incubated at 37 degrees C, 5% CO2 for 3 h, and then processed for studies by scanning electronic microscopy. Statistical analysis was used to compare the quantitative differences. The number of spermatozoa significantly decreases during the regression period, while sperm motility was progressive speed in both periods. During the active period elevated sperm binding to cumulus-free and zona-free oocytes was observed, while the binding during the regression period decreased drastically. In both periods, oocyte microvilli covered sperm heads and tails. These results suggest that the ability of viscacha spermatozoa to participate in gamete recognition is profoundly affected. This would likely be related to different functional stages of the spermatozoa and their epididymal microenvironment during the annual reproductive cycle of viscacha. PMID:16524245

  5. Scanning electron microscopical studies of developing of vallate papillae in the rabbit (Oryctolagus cuniculus f. domestica

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    Mirosława Kulawik

    2013-12-01

    Full Text Available This study was conducted on 30 tongues of the rabbits (Oryctolagus cuniculus f. domestica of both sexes, which were collected at day 18, 20, 22 and 26 of prenatal development (E and at day 1, 15 and 30 of postnatal life (P. Developmental changes of the rabbit vallate papillae were studied using scanning electron microscopy (SEM. The study showed that the first primordia of vallate papillae were observed at E18. At E20, SEM revealed that primordia of this papillae could be recognized as a circular structures. The furrow of vallate papillae started to form from E22 and finished at P30. After removal the epithelium of the developing vallate papilla, round connective tissue core was exposed. From P1, connective tissue cores of these papillae were formed by varied in length and shape folds. There were irregular hollows between folds. Around connective tissue core there was a circular depression and elevation. Starting from E26 on the surface of developing papillae exfoliating epithelium cells were observed.

  6. Scanning Electron Microscopic Structure of the Lingual Papillae of the Common Opossum (Didelphis marsupialis)

    Science.gov (United States)

    Okada, Shigenori; Schraufnagel, Dean E.

    2005-08-01

    The mammalian tongue has evolved for specialized functions in different species. The structure of its papillae tells about the animal's diet, habit, and taxonomy. The opossum has four kinds of lingual papillae (filiform, conical, fungiform, vallate). Scanning electron microscopy of the external features, connective tissue cores, and corrosion casts of the microvasculature show the filiform papillae have a spearhead-like main process and spiny accessory processes around the apical part of the main process. The shape and number of both processes depend on their position on the tongue. On the apex, the main processes have shovel-like capillary networks and the accessory processes have small conical networks. On the lingual radix, the processes have small capillary loops. In the patch region, conical papillae have capillaries arranged as a full sail curving posteriorly. The fungiform papillae are scattered among the filiform papillae and have capillary baskets beneath each taste bud. Giant fungiform papillae on the tongue tip are three to four times larger than the ones on the lingual body. Capillaries of giant papillae form a fan-shaped network. The opossum has three vallate papillae arranged in a triangle. Their tops have secondary capillary loops but not their lateral surfaces. Mucosal folds on the posterolateral border have irregular, fingerlike projections with cylindrical capillary networks. These findings and the structure of the rest of the masticatory apparatus suggest the lingual papillae of opossum have kept their ancestral carnivorous features but also developed the herbivore characteristics of other marsupials.

  7. Correlation between auditory brainstem recordings and morphology as seen through the scanning electron microscope

    International Nuclear Information System (INIS)

    Pregnant CBA/CBA mice were exposed to 0.5, 1 and 2 Grey (Gy), (1 Gy = 100 rad) in single doses with whole body gamma-irradiation on the 12th, 13th and 16th gestational days, respectively. The animals were tested at an age of one month for vestibular and cochlear function. Thereafter the inner ears were analyzed with scanning electron microscopy. A morphological analysis with cytocochleograms was performed. Morphological changes in the vestibular part showed gross malformations in the cristae ampullares. Hair cells of type I seemed to be more severely changed than hair cells type II. The macula utriculi also showed malformations of the otoconia. All these changes were more pronounced when the irradiation was given early during pregnancy and with the highest doses used, except the otoconia which were more injured when irradiated day 16 of gestation. No disturbances of the equilibrium reflexes were noted. In the cochlea a dose-dependent, time-related damage pattern was demonstrated with pathological changes of outer (OHC) and inner (IHC) hair cells. When tested electrophysiologically for auditory function with auditory brainstem recordings (ABR), elevated thresholds were revealed different in shape depending on when during pregnancy irradiation took place. A good correlation existed between the morphological changes as seen in the cytocochleograms and the functional changes documented with the ABR

  8. A light, transmission and scanning electron microscope study of snuff-treated hamster cheek pouch epithelium.

    Science.gov (United States)

    Ashrafi, S H; Das, A; Worowongvasu, R; Mehdinejad, B; Waterhouse, J P

    1992-03-01

    The effects of smokeless tobacco (snuff) on hamster cheek mucosa were studied by light microscopy, transmission (TEM) and scanning electron microscopy (SEM). Two grams of commercially available smokeless tobacco were placed into the blind end of the right cheek pouch of each experimental animal, once a day and five days a week for 24 months. The control animals did not receive smokeless tobacco. After 24 months treatment with smokeless tobacco, hamster cheek mucosal epithelium lost its translucency and had become whitish in color. By light microscopy hyperorthokeratosis, prominent granular cell layers with increased keratohyalin granules and hyperplasia were seen. At the ultrastructural level, wider intercellular spaces filled with microvilli, numerous shorter desmosomes, many thin tonofilament bundles, increased number of mitochondria, membrane coating granules and keratohyalin granules were seen in snuff-treated epithelium. The changes in the surface of the epithelium as seen by SEM were the development of an irregular arrangement of the microridges and the disappearance of the normal honeycomb pattern. The microridges were irregular, widened and surrounded the irregular elongated pits. Some smooth areas without microridges and pits were also seen. The long-term histological, TEM and SEM changes induced by smokeless tobacco treatment of the epithelium are well correlated with each other and were similar to those reported in human leukoplakia without dyskeratosis. They imply changes of pathological response resulting from topically applied snuff.

  9. Mechanical properties of SiC nanowires determined by scanning electron and field emission microscopies

    Science.gov (United States)

    Perisanu, S.; Gouttenoire, V.; Vincent, P.; Ayari, A.; Choueib, M.; Bechelany, M.; Cornu, D.; Purcell, S. T.

    2008-04-01

    We present here comparative measurements by scanning electron microscopy (SEM) and field emission (FE) of the mechanical resonances of singly clamped, batch-fabricated SiC nanowires as well as an extensive theoretical description. The mechanical resonances of six nanowires, which were glued to the ends of tungsten support tips, were electrostatically excited and detected visually in the SEM configuration and then by FE microscopy image processing. The large tensions generated by electric field pulling in FE that tune the resonance frequencies and the complex boundary conditions at both the free and clamped nanowire ends complicate the interpretation of the resonance frequencies necessary for extracting intrinsic mechanical parameters. Our model fully takes into account these effects and results in an excellent agreement with the measured resonance modes in both configurations. Analytical solutions with their validity conditions are given for the low and high tension ranges and semianalytical solutions for the intermediary range. Viable estimates of Young’s modulus are thus achieved for the ultra high vacuum (UHV) environment of FE. Progressive in situ cleaning was performed in the FE-UHV configuration in the range of 600-1350K , which increased the Q factor of the first mechanical resonance by up to ×100 and did not alter the value of the Young’s modulus measured previously in the SEM configuration. The agreement between the SEM and FE techniques means that we can now profit from their different strengths for better understanding the mechanics of nanowires and nanotubes.

  10. Analysis of long-range bullet entrance holes by atomic absorption spectrophotometry and scanning electron microscopy.

    Science.gov (United States)

    Ravreby, M

    1982-01-01

    Bullet residue and primer particles were analyzed by scanning electron microscopy with energy dispersive analysis (SEM-EDA) and by flame and flameless atomic absorption spectrophotometry (AAS). The residue and particles were on cloth targets around entrance holes produced by bullets fired at distances of 10 to 200 m. Primer particles and their chemical constituents were almost always detected by SEM-EDA around the holes produced by rifles and pistols fired at long ranges, and in many cases the barium and antimony associated with primer particles were detected by flameless AAS. Particles were also detected by SEM-EDA on the rear of bullets fired into and recovered from wooden blocks. Usually a hole caused by a bullet jacketed with gilding metal could be distinguished from one caused by a bullet jacketed with yellow brass alloy. Paint from bullet tips of military tracers was also detected. Analysis of the various residues around entrance holes provides a means for identifying the type of ammunition used. PMID:7097199

  11. Analysis of sealing ability of root canal sealers using scanning electronic microscopy technique

    Directory of Open Access Journals (Sweden)

    Vujašković Mirjana

    2010-01-01

    Full Text Available Introduction. An ideal endodontic sealer should adhere firmly both to dentin and to gutta-percha. Objective. The aim of this study was to evaluate the adhesion of the root canal filling to dentin and gutta-percha using scanning electronic microscopy (SEM. Methods. The sealing ability of endodontic sealers to dentinal walls of the root canal was assessed in recently extracted human single canal premolars. Twenty teeth were prepared using the crown-down technique and irrigated with 3% NaOCl. A total of 20 samples were divided into two groups. The root canals were obturated using Ketac-Endo Aplicap and GutaFlow. The sealing ability and adhesion properties at the sealer-dentin interface were studied using SEM and the results were rated from 1 to 3; extremely good adhesion (rated 1, good adhesion (rated 2 and a relatively good adhesion (rated 3. Results. The results showed extremely good adhesion on Ketac-Endo and GuttaFlow dentin interface. GuttaFlow has strong adhesion (rated 1 to gutta-percha in comparison with Ketac-Endo to gutta-percha interface (rated 2. Conclusion. New GuttaFlow filling material has a strong sealing ability and excellent adhesion to dentinal walls and gutta-percha cones. Ketac-Endo showed excellent bond to dentin with a slightly weaker adhesion capacity to the gutta-percha cones in comparison to GuttaFlow.

  12. Cellulose microfibril-water interaction as characterized by isothermal thermogravimetric analysis and scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Suman K. Sen

    2012-11-01

    Full Text Available Microfibrillated celluloses, liberated from macroscopic lignocellulosic fibers by mechanical means, are sub-fiber elements with lengths in the micron scale and diameters ranging from 10 to a few hundred nanometers. These materials have shown strong water interactions. This article describes an investigation and quantification of the ‘hard-to-remove (HR water content’ in cellulose fibers and microfibrillated structures prepared from fully bleached softwood pulp (BSW. The fiber/fibril structure was altered by using an extended beating process (up to 300 minutes, and water interactions were determined with isothermal thermogravimetric analysis (TGA. Isothermal TGA is shown to be a convenient and insightful characterization method for fiber-water interactions for fibers and microfibrils at small sample size. In addition, scanning electron microscopic (SEM images depict the differences between fibers and microfibrils with respect to beating time in the dried consolidated structures. Highly refined pulps with microfibrils were determined to have two critical drying points, i.e., two minima in the second derivative of weight versus time, not before reported in the literature. Also in this study, hard-to-remove (HR water content is related to the area above the first derivative curve in the constant rate and falling rate drying zones. This measure of HR water correlates with a previous measurement method of HR water but is less ambiguous for materials that lack a constant drying rate zone. Blends of unbeaten fibers and microfibril containing samples were prepared and show potential as composite materials.

  13. Dentin Cleaning Ability of an Amazon Bioactive: Evaluation by Scanning Electron Microscopy

    Science.gov (United States)

    Bandeira, Maria Fulgência C.L.; Lima, Geisy R.; Lopes, Patrícia P.; Toda, Carina; Venâncio, Gisely N.; Lima, Greiciane A.; de Vasconcellos, Marne C.; Martins, Leandro M.; Sampaio, Fâbio C.; Conde, Nikeila C. de Oliveira

    2016-01-01

    The role of dentin cleaning is to remove debris that may impair adaptation and marginal sealing, quantitatively reducing microorganisms. The aim of this study was to investigate through scanning electron microscopy (SEM) the morphology of the dentin surface, cut and treated with copaiba oil emulsions (CO) and suspension of ethanol extract of propolis (EP). Twenty four upper pre-molars teeth, divided into eight groups (n=3), were used: G1: no cleaning, G2: air/water spray, G3: 10% CO, G4: 10% CO + A, G5: 30% CO, G6: 30% CO + A, G7: 1% EP, G8: 2% Chlorhexidine. The specimens were dentin discs (1 mm Ø). The SEM photomicrographs were classified and the results were: G1 - Debris dentin on the entire image / countless microorganisms, G2 and G7 - 50-100 debris / countless microorganisms and G3, G4, G5, G6 and G8 - 0-50 debris / countable microorganisms (50-100 colonies). Conclusion: The present results suggest that copaiba oil emulsions (CO) and suspension of ethanol extract of propolis (EP) have feasibility to be used as bioactive dental cleaning agents. PMID:27386003

  14. [Development of ultrastructural changes in human cervix mucus during the ovarian cycle. Scanning electron microscope study].

    Science.gov (United States)

    Chrétien, F C; Cohen, J; Psychoyos, A

    1976-01-01

    The use of the Scanning Electron Microscope has made it possible through observation to study the human cervical mucus through the various stages of the ovarian cycle, as well as to describe the significant variations of the meshed woof making up the ultrastructure during the ovarian cycle. While the slackening of the woof and the dimension of the meshes are minimal at both the beginning and end of the cycle, they reach a maximum on forteenth day. In the ovulatory period, lateral expansions from the filaments are numerous. On the other hand, median and terminal thicknesses are almost inexistant during the same period : their frequency decreases during the first part of the cycle, then increases during the luteal phase. During both the preceding and following days of ovulation, one can observe numerous twistings at the level of the filaments which probably express the relaxation and then contraction of the latter. The preparatory technique as well as the method of observation used appear reliable enough to allow a comparison of the cervical mucus ultrastructure in varied physiological, pathological and experimental situations. PMID:956619

  15. Scanning Electron Microscopy of Macerated Tissue to Visualize the Extracellular Matrix.

    Science.gov (United States)

    Stephenson, Matthew K; Lenihan, Sean; Covarrubias, Roman; Huttinger, Ryan M; Gumina, Richard J; Sawyer, Douglas B; Galindo, Cristi L

    2016-06-14

    Fibrosis is a component of all forms of heart disease regardless of etiology, and while much progress has been made in the field of cardiac matrix biology, there are still major gaps related to how the matrix is formed, how physiological and pathological remodeling differ, and most importantly how matrix dynamics might be manipulated to promote healing and inhibit fibrosis. There is currently no treatment option for controlling, preventing, or reversing cardiac fibrosis. Part of the reason is likely the sheer complexity of cardiac scar formation, such as occurs after myocardial infarction to immediately replace dead or dying cardiomyocytes. The extracellular matrix itself participates in remodeling by activating resident cells and also by helping to guide infiltrating cells to the defunct lesion. The matrix is also a storage locker of sorts for matricellular proteins that are crucial to normal matrix turnover, as well as fibrotic signaling. The matrix has additionally been demonstrated to play an electromechanical role in cardiac tissue. Most techniques for assessing fibrosis are not qualitative in nature, but rather provide quantitative results that are useful for comparing two groups but that do not provide information related to the underlying matrix structure. Highlighted here is a technique for visualizing cardiac matrix ultrastructure. Scanning electron microscopy of decellularized heart tissue reveals striking differences in structure that might otherwise be missed using traditional quantitative research methods.

  16. Morphology of the Lingual and Buccal Papillae in Alpaca (Vicugna pacos) - Light and Scanning Electron Microscopy.

    Science.gov (United States)

    Goździewska-Harłajczuk, K; Klećkowska-Nawrot, J; Janeczek, M; Zawadzki, M

    2015-10-01

    The aim of this study was the description of the lingual and buccal papillae in adult alpaca (Vicugna pacos) by light and scanning electron microscopy (SEM). The tongue consisted of apex, body and root. Four types of lingual papillae (filiform, fungiform, conical and circumvallate) in addition to two types of buccal papillae were observed. The filiform papillae, some with secondary papillae, were distributed on both the corpus and apex of the tongue, with stratified epithelium, and layer of keratin coat were recognized. The short (small) cone papillae had pointed top, while bunoform papillae were wide with smooth apex. The much less numerous circumvallate papillae with pseudopapillae on the each rim of the caudal lingual body were present with weak layer of keratin and intra-epithelial taste buds. The small fungiform papillae were found on the dorsal lingual surface, while the large fungiform papillae were situated on the ventral surface of the tongue, especially, in rostral part and were round in shape with numerous gustatory pores and very thin keratin coat. Pseudopapillae were present on the buccal conical 'bunoform' papillae surface, while 'elongate' buccal papillae surface was rather softly folded with thin coat of keratin. Microridges were observed in the less keratinized parts of each type of papillae. The orientation of either lingual or buccal papillae into the throat side facilitates the emptying of oral cavity from nutrient and swallowing of food. In conclusion, the anatomical features of the alpaca tongue are an adaptation to the feeding habits.

  17. Multi-resolution correlative focused ion beam scanning electron microscopy: applications to cell biology.

    Science.gov (United States)

    Narayan, Kedar; Danielson, Cindy M; Lagarec, Ken; Lowekamp, Bradley C; Coffman, Phil; Laquerre, Alexandre; Phaneuf, Michael W; Hope, Thomas J; Subramaniam, Sriram

    2014-03-01

    Efficient correlative imaging of small targets within large fields is a central problem in cell biology. Here, we demonstrate a series of technical advances in focused ion beam scanning electron microscopy (FIB-SEM) to address this issue. We report increases in the speed, robustness and automation of the process, and achieve consistent z slice thickness of ∼3 nm. We introduce "keyframe imaging" as a new approach to simultaneously image large fields of view and obtain high-resolution 3D images of targeted sub-volumes. We demonstrate application of these advances to image post-fusion cytoplasmic intermediates of the HIV core. Using fluorescently labeled cell membranes, proteins and HIV cores, we first produce a "target map" of an HIV infected cell by fluorescence microscopy. We then generate a correlated 3D EM volume of the entire cell as well as high-resolution 3D images of individual HIV cores, achieving correlative imaging across a volume scale of 10(9) in a single automated experimental run.

  18. Susceptibility of limestone petrographic features to salt weathering: a scanning electron microscopy study.

    Science.gov (United States)

    Alves, Carlos; Figueiredo, Carlos; Maurício, António; Aires-Barros, Luís

    2013-10-01

    Salt weathering is a major erosive process affecting porous materials in buildings. There have been attempts to relate erosive mass loss to physical characteristics of materials, but in the case of natural stone it is necessary to consider the effect of petrographic features that are a source of heterogeneity. In this paper, we use scanning electron microscopy before and after salt weathering tests in cubic specimens of three limestone types (two grainstones and a travertine) in an attempt to built conceptual models that relate petrographic features and salt weathering susceptibility (represented by mass loss). In the grainstones, the most relevant feature in controlling salt weathering processes is the interface between micrite aggregates and sparry cement that constitute weakness surfaces and barriers to fluid migration. Given the small size of the heterogeneities in relation to the test sample dimension and their spatial distribution, the macroscopic erosive patterns are globally homogeneously distributed, affecting edges and corners. In the travertine specimens, there are macroheterogeneities related to the presence of detritic-rich portions that cause heterogeneous erosive patterns in the specimens. Petrological modeling helps to understand results of salt weathering tests, supporting field studies for natural stone selection. PMID:23702191

  19. Ultra-structural hair alterations of drug abusers: a scanning electron microscopic investigation.

    Science.gov (United States)

    Turkmenoglu, Fatma Pinar; Kasirga, Ugur Baran; Celik, Hakan Hamdi

    2015-01-01

    As drug abuse carries a societal stigma, patients do not often report their history of drug abuse to the healthcare providers. However, drug abuse is highly co-morbid with a host of other health problems such as psychiatric disorders and skin diseases, and majority of individuals with drug use disorders seek treatment in the first place for other problems. Therefore, it is very important for physicians to be aware of clinical signs and symptoms of drug use. Recently diagnostic value of dermatologic tissue alterations associated with drug abuse has become a very particular interest because skin changes were reported to be the earliest noticeable consequence of drug abuse prompting earlier intervention and treatment. Although hair is an annex of skin, alterations on hair structure due to drug use have not been demonstrated. This study represents the first report on ultra-structural hair alterations of drug abusers. We have investigated ultra-structure of the hair samples obtained from 6 cocaine, 6 heroin, 7 cannabis and 4 lysergic acid diethylamide (LSD) abusers by scanning electron microscope (SEM). SEM analysis of hair samples gave us drug-specific discriminating alterations. We suggest that results of this study will make a noteworthy contribution to cutaneous alterations associated with drug abuse which are regarded as the earliest clinical manifestations, and this SEM approach is a very specific and effective tool in the detection of abuse of respective drugs, leading early treatment. PMID:26309532

  20. Automated defect review of the wafer bevel with a defect review scanning electron microscope

    Science.gov (United States)

    McGarvey, Steve; Kanezawa, Masakazu

    2009-03-01

    One of the few remaining bastions of non-regulated Integrated Circuit defectivity is the wafer bevel. Recent internal Integrated Circuit Manufacturing studies have suggested that the edge bevel may be responsible for as much as a two to three percent yield loss during a defect excursion on the manufacturing line and a one to two percent yield loss during ongoing wafer manufacturing. A new generation of defect inspection equipment has been introduced to the Research and Development, Integrated Circuit, MEM's and Si wafer manufacturing markets that has imparted the ability for the end equipment user to detect defects located on the bevel of the wafer. The inherent weakness of the current batch of wafer bevel inspection equipment is the lack of automatic discrete defect classification data into multiple, significant classification bins and the lack of discrete elemental analysis data. Root cause analysis is based on minimal discrete defect analysis as a surrogate for a statistically valid sampling of defects from the bevel. This paper provides a study of the methods employed with a Hitachi RS-5500EQEQ Defect Review Scanning Electron Microscope (DRSEM) to automatically capture high resolution/high magnification images and collect elemental analysis on a statistically valid sample of the discrete defects that were located by a bevel inspection system.

  1. Assessment of fluidity of different invasomes by electron spin resonance and differential scanning calorimetry.

    Science.gov (United States)

    Dragicevic-Curic, Nina; Friedrich, Manfred; Petersen, Silvia; Scheglmann, Dietrich; Douroumis, Dennis; Plass, Winfried; Fahr, Alfred

    2011-06-30

    The aim of this study was to investigate the influence of membrane-softening components (terpenes/terpene mixtures, ethanol) on fluidity of phospholipid membranes in invasomes, which contain besides phosphatidylcholine and water, also ethanol and terpenes. Also mTHPC was incorporated into invasomes in order to study its molecular interaction with phospholipids in vesicular membranes. Fluidity of bilayers was investigated by electron spin resonance (ESR) using spin labels 5- and 16-doxyl stearic acid and by differential scanning calorimetry (DSC). Addition of 1% of a single terpene/terpene mixture led to significant fluidity increase around the C16 atom of phospholipid acyl chains comprising the vesicles. However, it was not possible to differentiate between the influences of single terpenes or terpene mixtures. Incorporation of mTHPC into the bilayer of vesicles decreased fluidity near the C16 atom of acyl chains, indicating its localization in the inner hydrophobic zone of bilayers. These results are in agreement with DSC measurements, which showed that terpenes increased fluidity of bilayers, while mTHPC decreased fluidity. Thus, invasomes represent vesicles with very high membrane fluidity. However, no direct correlation between fluidity of invasomes and their penetration enhancing ability was found, indicating that besides fluidity also other phenomena might be responsible for improved skin delivery of mTHPC.

  2. Imaging with low-voltage scanning transmission electron microscopy: A quantitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Felisari, L. [TASC, INFM-CNR, S.S. 14, km 163.5, 34149 Trieste (Italy); Grillo, V., E-mail: vincenzo.grillo@unimore.it [Istituto Nanoscienze-S3 CNR, via Campi 213/A, 41125 Modena (Italy); IMEM-CNR Parco Area delle Scienze 37/A, 43124 Parma (Italy); Jabeen, F.; Rubini, S. [TASC, INFM-CNR, S.S. 14, km 163.5, 34149 Trieste (Italy); Menozzi, C. [Istituto Nanoscienze-S3 CNR, via Campi 213/A, 41125 Modena (Italy); Dipartimento di Fisica, Universita di Modena e Reggio Emilia Via G. Campi 213/A, 41100 Modena (Italy); Rossi, F. [IMEM-CNR Parco Area delle Scienze 37/A, 43124 Parma (Italy); Martelli, F. [TASC, INFM-CNR, S.S. 14, km 163.5, 34149 Trieste (Italy); IMM-CNR, via del Fosso del Cavaliere 100, 00133 Roma (Italy)

    2011-07-15

    A dedicated specimen holder has been designed to perform low-voltage scanning transmission electron microscopy in dark field mode. Different test samples, namely InGaAs/GaAs quantum wells, InGaAs nanowires and thick InGaAs layers, have been analysed to test the reliability of the model based on the proportionality to the specimen mass-thickness, generally used for image intensity interpretation of scattering contrast processes. We found that size of the probe, absorption and channelling must be taken into account to give a quantitative interpretation of image intensity. We develop a simple procedure to evaluate the probe-size effect and to obtain a quantitative indication of the absorption coefficient. Possible artefacts induced by channelling are pointed out. With the developed procedure, the low voltage approach can be successfully applied for quantitative compositional analysis. The method is then applied to the estimation of the In content in the core of InGaAs/GaAs core-shell nanowires. -- Highlights: {yields} Quantitative analysis of the composition by low-voltage STEM annular dark field. {yields} First evidence of channelling effects in low-voltage STEM in SEM. {yields} Comparison between low-voltage and high-voltage STEM. {yields} Evaluation of the absorption effects on the STEM intensity.

  3. Production of muscovite-feldspathic glass composite: scanning electron microscopy and X-ray diffraction analysis

    International Nuclear Information System (INIS)

    The objective of this work was to find the sintering conditions for the feldspathic glass + muscovite mixture to produce a dense composite block for manufacturing dental prosthesis by using CAD-CAM. Each 20g of the glass-frit had : 15.55g of Armil-feldspar; 0.53g of Al2O3; 1.56g of Na2CO3; 0.5g of borax; 1.74g of K2CO3; 0.13g of CeO2. Frit's powder finer than 350 Tyler mesh was mixed with 0 wt%, 10 wt%, 20 wt% and 100 wt% of muscovite pressed cylinders (5600 pounds force) 16mm in diameter and sintered under vacuum Vacumat (VITA) furnace at 850 deg C, 900 deg C, 950 deg C, 1000 deg C, 1050 deg C, 1100 deg C and 1150 deg C. X-ray diffraction analysis and scanning electron microscopy were carried out. The necessary temperature for high densification depended on the composition of the mixture: 850 deg C (for pure frit); 1050 deg C (for 10 wt% mica) and 1150 deg C (for 20 wt% mica); pure mica degraded during sintering. (author)

  4. Design and Application of Variable Temperature Environmental Capsule for Scanning Electron Microscopy in Gases and Liquids at Ambient Conditions

    OpenAIRE

    Al-Asadi, Ahmed S.; Jie ZHANG; Li, Jianbo; Potyrailo, Radislav A.; Kolmakov, Andrei

    2015-01-01

    Scanning electron microscopy (SEM) of nanoscale objects in their native conditions and at different temperatures are of critical importance in revealing details of their interactions with ambient environments. Currently available environmental capsules are equipped with thin electron transparent membranes and allow imaging the samples at atmospheric pressure. However these capsules do not provide the temperature control over the sample. Here we developed and tested a thermoelectric cooling / ...

  5. A Novel Two-Axis Load Sensor Designed for in Situ Scratch Testing inside Scanning Electron Microscopes

    OpenAIRE

    Chengli Shi; Hu Huang; Hongwei Zhao; Boda Wu; Shunguang Wan

    2013-01-01

    Because of a lack of available miniaturized multiaxial load sensors to measure the normal load and the lateral load simultaneously, quantitative in situ scratch devices inside scanning electron microscopes and the transmission electron microscopes have barely been developed up to now. A novel two-axis load sensor was designed in this paper. With an I-shaped structure, the sensor has the function of measuring the lateral load and the normal load simultaneously, and at the same time it has comp...

  6. Study of Scanning Tunneling Microscope control electronics. Estudio del Sistema de Control y Estabilidad en el microscopico de efecto tunel

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, A.J.; Pancarobo, M.; Denisenko, N.; Aguilar, M.; Rejon, V.; Pea, J.L. (Instituto de Ciencia de Materiales, CSIC, Universidad Autonoma de Madrid, Madrid (Spain))

    1994-01-01

    A theoretical study of Scanning Tunneling Microscope control electronics is made. The knowledge of its behaviour allows us to determine accurately the region where the unstable operation could effect the measurements, and also to set the optimal working parameters. Each feedback circuitry compound is discussed as well as their mutual interaction. Different working conditions analysis and results are presented. (Author) 12 refs.

  7. Spiral conformation of Vibrio cholerae as determined by scanning electron microscopy of elongated cells induced by cephalexin treatment.

    OpenAIRE

    Konishi, H.; Katayama, A.; Ito, T.; Tanaka, S.; Yoshii, Z

    1986-01-01

    The elongated cells of Vibrio spp. induced by cephalexin treatment were examined by scanning electron microscopy. The results showed that Vibrio cholerae has a twisted cell body and a right-handed spiral conformation and that the cell bodies of V. parahaemolyticus and V. alginolyticus are straight rather than curved.

  8. Scanning electron-microscopic and X-ray-microanalytic observation of diesel-emission particles associated with mutagenicity

    International Nuclear Information System (INIS)

    The particles formed by diesel combustion, which may contain various mutagenic chemicals like polycyclic aromatic hydrocarbons (PAH), are analyzed in their morphology by scanning electron microscopy; their sulfur content is detected by X-ray microanalysis, and mutagenicity is tested with a Salmonella typhimurium bioassay. The authors find a close correlation between sulfur content and mutagenicity of PAH. (Auth.)

  9. The early development of inflorescences and flowers of the oil palm (Elaeis guineensis Jacq.) seen through the scanning electron microscope

    NARCIS (Netherlands)

    Heel, van W.A.; Breure, C.J.; Menendez, T.

    1987-01-01

    The development of inflorescences and flowers of the African Oil Palm up to anthesis is illustrated by scanning electron microscopy images. The time of origin relative to the development of the foliage leaves of the basipetalous succession of flowering rachillae is determined, as well as the time of

  10. Cryo DualBeam Focused Ion Beam–Scanning Electron Microscopy to Evaluate the Interface Between Cells and Nanopatterned Scaffolds

    NARCIS (Netherlands)

    Lamers, Edwin; Walboomers, X. Frank; Domanski, Maciej; McKerr, George; O'Hagan, Barry M.; Barnes, Clifford A.; Peto, Lloyd; Lüttge, Regina; Winnubst, Louis A.J.A.; Gardeniers, Han J.G.E.; Jansen, John A.

    2011-01-01

    With the advance of nanotechnology in biomaterials science and tissue engineering, it is essential that new techniques become available to observe processes that take place at the direct interface between tissue and scaffold materials. Here, Cryo DualBeam focused ion beam–scanning electron microscop

  11. The morphology of the stigma surface of Petunia hybrida hort. superbissima as seen in scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    S. Muszyński

    2015-05-01

    Full Text Available The ultrastructure of stigma surface in allotetraploid petunias was analyzed by scanning electron microscopy. The stigma forms a bilobed structure with. a distinct central depression. The stigma surface is covered with numerous. papillate hairs of ununiform sizes and shapes.

  12. LOW-VOLTAGE FIELD-EMISSION SCANNING ELECTRON-MICROSCOPY OF NON-COATED GUINEA-PIG HAIR CELL STEREOCILIA

    NARCIS (Netherlands)

    DUNNEBIER, EA; SEGENHOUT, JM; KALICHARAN, D; JONGEBLOED, WL; WIT, HP; ALBERS, FWJ

    1995-01-01

    The stereociliar structures of the guinea-pig cochlear organ of Corti were studied at low-voltage (1-5 kV) with field-emission scanning electron microscope (SEM) using various pre- and post-fixation methods, such as OTOTO (OsO4/thiocarbohydrazide/OsO4/thiocarbohydrazide/OsO4) and TAO (tannic acid/ar

  13. Advantages of indium-tin oxide-coated glass slides in correlative scanning electron microscopy applications of uncoated cultured cells.

    NARCIS (Netherlands)

    Pluk, H.; Stokes, D.J.; Lich, B.; Wieringa, B.; Fransen, J.A.M.

    2009-01-01

    A method of direct visualization by correlative scanning electron microscopy (SEM) and fluorescence light microscopy of cell structures of tissue cultured cells grown on conductive glass slides is described. We show that by growing cells on indium-tin oxide (ITO)-coated glass slides, secondary elect

  14. Electronic properties of conductive pili of the metal-reducing bacterium Geobacter sulfurreducens probed by scanning tunneling microscopy

    Science.gov (United States)

    Veazey, Joshua P.; Reguera, Gemma; Tessmer, Stuart H.

    2011-12-01

    The metal-reducing bacterium Geobacter sulfurreducens produces conductive protein appendages known as “pilus nanowires” to transfer electrons to metal oxides and to other cells. These processes can be harnessed for the bioremediation of toxic metals and the generation of electricity in bioelectrochemical cells. Key to these applications is a detailed understanding of how these nanostructures conduct electrons. However, to the best of our knowledge, their mechanism of electron transport is not known. We used the capability of scanning tunneling microscopy (STM) to probe conductive materials with higher spatial resolution than other scanning probe methods to gain insights into the transversal electronic behavior of native, cell-anchored pili. Despite the presence of insulating cellular components, the STM topography resolved electronic molecular substructures with periodicities similar to those reported for the pilus shaft. STM spectroscopy revealed electronic states near the Fermi level, consistent with a conducting material, but did not reveal electronic states expected for cytochromes. Furthermore, the transversal conductance was asymmetric, as previously reported for assemblies of helical peptides. Our results thus indicate that the Geobacter pilus shaft has an intrinsic electronic structure that could play a role in charge transport.

  15. Generation and Characterization of Nanoaerosols Using a Portable Scanning Mobility Particle Sizer and Electron Microscopy

    Science.gov (United States)

    Marty, Adam J.

    The purpose of this research is to demonstrate the ability to generate and characterize a nanometer sized aerosol using solutions, suspensions, and a bulk nanopowder, and to research the viability of using an acoustic dry aerosol generator/elutriator (ADAGE) to aerosolize a bulk nanopowder into a nanometer sized aerosol. The research compares the results from a portable scanning mobility particle sizer (SMPS) to the more traditional method of counting and sizing particles on a filter sample using scanning electron microscopy (SEM). Sodium chloride aerosol was used for the comparisons. The sputter coating thickness, a conductive coating necessary for SEM, was measured on different sizes of polystyrene latex spheres (PSLS). Aluminum oxide powder was aerosolized using an ADAGE and several different support membranes and sound frequency combinations were explored. A portable SMPS was used to determine the size distributions of the generated aerosols. Polycarbonate membrane (PCM) filter samples were collected for subsequent SEM analysis. The particle size distributions were determined from photographs of the membrane filters. SMPS data and membrane samples were collected simultaneously. The sputter coating thicknesses on four different sizes of PSLS, range 57 nanometers (nm) to 220 nm, were measured using transmission electron microscopy and the results from the SEM and SMPS were compared after accounting for the sputter coating thickness. Aluminum oxide nanopowder (20 nm) was aerosolized using a modified ADAGE technique. Four different support membranes and four different sound frequencies were tested with the ADAGE. The aerosol was collected onto PCM filters and the samples were examined using SEM. The results indicate that the SMPS and SEM distributions were log-normally distributed with a median diameter of approximately 42 nm and 55 nm, respectively, and geometric standard deviations (GSD) of approximately 1.6 and 1.7, respectively. The two methods yielded similar

  16. Studies of the small bowel surface by scanning electron microscopy in infants with persistent diarrhea

    Directory of Open Access Journals (Sweden)

    U. Fagundes-Neto

    2000-12-01

    Full Text Available We describe the ultrastructural abnormalities of the small bowel surface in 16 infants with persistent diarrhea. The age range of the patients was 2 to 10 months, mean 4.8 months. All patients had diarrhea lasting 14 or more days. Bacterial overgrowth of the colonic microflora in the jejunal secretion, at concentrations above 10(4 colonies/ml, was present in 11 (68.7% patients. The stool culture was positive for an enteropathogenic agent in 8 (50.0% patients: for EPEC O111 in 2, EPEC O119 in 1, EAEC in 1, and Shigella flexneri in 1; mixed infections due to EPEC O111 and EAEC in 1 patient, EPEC O119 and EAEC in 1 and EPEC O55, EPEC O111, EAEC and Shigella sonnei in 1. Morphological abnormalities in the small bowel mucosa were observed in all 16 patients, varying in intensity from moderate 9 (56.3% to severe 7 (43.7%. The scanning electron microscopic study of small bowel biopsies from these subjects showed several surface abnormalities. At low magnification (100X most of the villi showed mild to moderate stunting, but on several occasions there was subtotal villus atrophy. At higher magnification (7,500X photomicrographs showed derangement of the enterocytes; on several occasions the cell borders were not clearly defined and very often microvilli were decreased in number and height; in some areas there was a total disappearance of the microvilli. In half of the patients a mucus-fibrinoid pseudomembrane was seen partially coating the enterocytes, a finding that provides additional information on the pathophysiology of persistent diarrhea.

  17. Elaphostrongylus spp. from Scandinavian cervidae - a scanning electron microscope study (SEM

    Directory of Open Access Journals (Sweden)

    Margareta Stéen

    1990-08-01

    Full Text Available Nematodes of the genus Elaphostrongylus collected from moose (Alces alces L., reindeer (Rangifer tarandus tarandus L., and red deer (Cervus elaphus L., respectively, were studied by means of scanning electron microscopy. Morphological differences in the ribs of the genital bursa were demonstrated. The Elaphostrongylus species from reindeer and red deer differed from each other in four ribs of the genital bursa. These results agree with the morphological characters of E. cervi and E. rangiferi described by Cameron (1931 and Mitskevitch (1960. The genital bursa of Elaphostrongylus sp. from moose, in accordance with the description of E. alces by Steen et al. (1989 showed characteristics differing from those found in Elaphostrongylus spp. from reindeer and red deer respectively. These results support the hypothesis that there are three separate species of Elaphostrongylus present in Scandinavian Cervidae. Svep-elektroniska studier på Elaphostrongylus spp. hos skandinaviska hjortdjur.Abstract in Swedish / Sammandrag: Rundmaskar inom slaktet Elaphostrongylus funna hos alg (Alces alces L., ren (Rangifer tarandus tarandus L. och kronhjort(Cervus elaphus L. studerades med hjalp av svepelelektronmikroskop. De hanliga bursorna med sin a stodjeribbor uppvisade variationer i utseende, langd och placering mellan dessa rundmaskar. De arter av Elaphostrongylus funna hos ren och kronhjort skilde sig åt avseende fyra stodjeribbor på de hanliga bursorna. Dessa resultat stammer val overens med de karaktarer som tidigare ar beskrivna av Cameron(1931 och av Mitskevich (1960. Den hanliga bursan hos arten Elaphostrongylus funnen hos alg, vilken tidigare ar beskriven av Steen et al. (1989, visade upp ett utseende som skilde sig från bursorna hos de Elaphostrongylus-arter funna hos ren och kronhjort. Dessa resultat stoder hypotesen om tre skilda arter av Elaphostrongylus hos skandinaviska hjortdjur.

  18. A scanning electron microscopic study of the patterns of external root resorption under different conditions

    Directory of Open Access Journals (Sweden)

    Ravindran Sreeja

    2009-10-01

    Full Text Available OBJECTIVE: The aim of this study was to examine if there are qualitative differences in the appearance of external root resorption patterns of primary teeth undergoing physiologic resorption and permanent teeth undergoing pathological root resorption in different conditions. MATERIAL AND METHODS: A total of 40 teeth undergoing external root resorption in different conditions were divided into 4 groups and prepared for examination under scanning electron microscopy at magnifications ranging from 20x to 1000x. Group I: 10 primary molars exfoliated due to physiologic root resorption; Group II: 10 permanent teeth with periapical granulomas showing signs of resorption; Group III:10 permanent teeth therapeutically extracted during the course of orthodontic therapy with evidence of resorption, and Group IV: 10 permanent teeth associated with odontogenic tumors that showed evidence of resorption. RESULTS: In Group I, the primary teeth undergoing resorption showed smooth extensive and predominantly regular areas reflecting the slow ongoing physiologic process. In Group II, the teeth with periapical granulomas showed the resorption was localized to apex with a funnel shaped appearance in most cases. Teeth in Group III, which had been subjected to a short period of light orthodontic force, showed the presence of numerous resorption craters with adjoining areas of cemental repair in some cases. Teeth associated with odontogenic tumors in Group IV showed many variations in the patterns of resorption with extensive loss of root length and a sharp cut appearance of the root in most cases. CONCLUSION: Differences were observed in the patterns of external root resorption among the studied groups of primary and permanent teeth under physiologic and pathological conditions.

  19. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    Directory of Open Access Journals (Sweden)

    Živković Slavoljub

    2010-01-01

    Full Text Available Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in this study were Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Candida albicans. A scanning electron microscope was used to evaluate root canal cleaning ability of 5.25% NaOCl, 2.5% NaOCl, 2% CHX and 15% EDTA. Twelve extracted single-root human teeth were divided into four groups depending on the irrigant used during instrumentation. Mechanical preparation was performed with Step back technique and K files. Data were analyzed statistically by Student’s t-test. Results 5.25% NaOCl was the most effective against all tested microorganisms. 2.5% NaOCl and 2% CHX showed antimicrobial effects against all tested microorganisms but zones of inhibition were smaller. The best results in root canal walls cleaning were obtained in the group where the irrigant was 15% EDTA (score 2.33. In 5.25% NaOCl, 2.5% NaOCl and 2% CHX groups, there was more smear layer (score 4 and 5. Conclusion. 2% chlorhexidine digluconate showed strong antimicrobial effect on the tested microorganisms, but was not effective in cleaning root canal walls.

  20. Description of the egg of Anopheles (Anopheles intermedius (Peryassu, 1908 (Diptera: Culicidae by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1997-01-01

    Full Text Available The egg of Anopheles (Anopheles intermedius (Peryassu, 1908 is described and illustrated with scanning electron micrographs. Literature data on An. (Ano. maculipes (Theobald, 1903 is providedOs ovos de An. intermedius foram descritos e ilustrados por Costa Lima (1929. Este autor, baseando-se nos desenhos de Peryassu (1908 para An. maculipes, chamou atenção para o fato do ovo desta espécie ser semelhante ao de An. maculipes. Posteriormente, Causey e col. (1944, estudando os ovos de An. intermedius e An. maculipes ao estereomicroscópio, diferenciou-os por caracteres da franja. Em An. intermedius a franja é oblíqua ao eixo longitudinal do ovo, mas perpendicular em An. maculipes. Causey e col. (1944 ilustraram as variações morfológicas que encontraram na franja do ovo de An. intermedius. Os autores observaram que a franja apresentava-se descotínua em alguns espécimens de An. intermedius, tornando-se em pequenos círculos nessa região. Embora semelhante ao de An. maculipes, os ovos de An. intermedius podem ser facilmente reconhecidos por características da franja, flutuadores e tubérculos lobados, como pode ser observado na descrição. Contudo, será necessário estudar a morfologia dos ovos de outras espécies do subgênero para que se possa estabelecer as diferenças e fazer comparações precisas entre as espécies

  1. The dimension of Trichomonas vaginalis as measured by scanning electron microscopy.

    Science.gov (United States)

    Cheon, Sang-Hoon; Kim, Seung Ryong; Song, Hyun-Ouk; Ahn, Myoung-Hee; Ryu, Jae-Sook

    2013-04-01

    It is known that physicochemical conditions (e.g., pH, temperature, and ionic strength) affect the size of trichomonads. In this study, the sizes of 4 isolates of Trichomonas vaginalis cultured for more than a year (called "old T") and 3 isolates freshly isolated from vaginitis cases (called "fresh T") were compared by scanning electron microscopy. Although the fresh T had shorter body length, body width, and flagellar length than old T, total length (about 26 µm), including body length, flagella length, and axostyle length was almost the same in the 2 groups. A striking difference was observed between the axostyles of the 2 groups; the axostyle length of the fresh T (8.2 µm) was more than twice as long as that of the old T (4.0 µm). However, in several parasitology textbooks, the length of T. vaginalis is said to vary widely from 7 to 32 µm, and its undulating membrane is said to extend about half way (53.5%) to the posterior end of the body. On the other hand, in our study, the undulating membrane was observed to extend more than 3/4 of the body length (72.1%) in old T, whereas in fresh T it could not be measured. Taken together, we suggest that T. vaginalis averages 26 (21-32) µm in total length, with 9.5 (7.4-11.4) µm of body length and 6.8 (5.3-7.7) µm of width, and its undulating membrane extending 3/4 of its body length. Therefore, these findings may provide useful information for morphological characteristics of T. vaginalis.

  2. SCANNING ELECTRON MICROSCOPY AND X-RAY DIFFRACTION ANALYSIS OF TANK 18 SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Hay, M.; O' Rourke, P.; Ajo, H.

    2012-03-08

    The F-Area Tank Farm (FTF) Performance Assessment (PA) utilizes waste speciation in the waste release model used in the FTF fate and transport modeling. The waste release modeling associated with the residual plutonium in Tank 18 has been identified as a primary contributor to the Tank 18 dose uncertainty. In order to reduce the uncertainty related to plutonium in Tank 18, a better understanding of the plutonium speciation in the Tank 18 waste (including the oxidation state and stoichiometry) is desired. Savannah River National Laboratory (SRNL) utilized Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to analyze Tank 18 samples to provide information on the speciation of plutonium in the waste material. XRD analysis of the Tank 18 samples did not identify any plutonium mineral phases in the samples. These indicates the crystalline mineral phases of plutonium are below the detection limits of the XRD method or that the plutonium phase(s) lack long range order and are present as amorphous or microcrystalline solids. SEM analysis of the Tank 18 samples did locate particles containing plutonium. The plutonium was found as small particles, usually <1 {micro}m but ranging up to several micrometers in diameter, associated with particles of an iron matrix and at low concentration in other elemental matrices. This suggests the plutonium has an affinity for the iron matrix. Qualitatively, the particles of plutonium found in the SEM analysis do not appear to account for all of the plutonium in the sample based on concentrations determined from the chemical analysis of the Tank 18 samples. This suggests that plutonium is also distributed throughout the solids in low concentrations.

  3. Bioresorption mechanisms of chitosan physical hydrogels: A scanning electron microscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Malaise, Sébastien, E-mail: sebastien.malaise@gmail.com [Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Ingénierie des Matériaux Polymères (IMP-UMR 5223), 15 Boulevard Latarjet, 69622 Villeurbanne Cedex (France); Rami, Lila [Université de Bordeaux, Bordeaux 33000 (France); Inserm U1026, Bioingénierie Tissulaire, Bordeaux 33000 (France); Montembault, Alexandra; Alcouffe, Pierre [Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Ingénierie des Matériaux Polymères (IMP-UMR 5223), 15 Boulevard Latarjet, 69622 Villeurbanne Cedex (France); Burdin, Béatrice [Université de Lyon, Université Claude Bernard Lyon 1, Centre Technologique des Microstructure, 69622 Villeurbanne Cedex (France); Bordenave, Laurence [Université de Bordeaux, Bordeaux 33000 (France); Inserm U1026, Bioingénierie Tissulaire, Bordeaux 33000 (France); CHU de Bordeaux, CIC-IT Biomaterials, F-33000 Bordeaux (France); Delmond, Samantha [CHU de Bordeaux, CIC-IT Biomaterials, F-33000 Bordeaux (France); David, Laurent [Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Ingénierie des Matériaux Polymères (IMP-UMR 5223), 15 Boulevard Latarjet, 69622 Villeurbanne Cedex (France)

    2014-09-01

    Tissue-engineered biodegradable medical devices are widely studied and systems must present suitable balance between versatility and elaboration simplicity. In this work, we aim at illustrating that such equilibrium can be found by processing chitosan physical hydrogels without external cross-linker. Chitosan concentration, degree of acetylation, solvent composition, and neutralization route were modulated in order to obtain hydrogels exhibiting different physico-chemical properties. The resulting in vivo biological response was investigated by scanning electron microscopy. “Soft” hydrogels were obtained from chitosan of high degree of acetylation (35%) and by the neutralization with gaseous ammonia of a chitosan acetate aqueous solutions presenting low polymer concentration (Cp = 1.6% w/w). “Harder” hydrogels were obtained from chitosan with lower degree of acetylation (5%) and after neutralization in sodium hydroxide bath (1 M) of hydro-alcoholic chitosan solutions (50/50 w/w water/1,2-propanediol) with a polymer concentration of 2.5% w/w. Soft and hard hydrogels exhibited bioresorption times from below 10 days to higher than 60 days, respectively. We also evidenced that cell colonization and neo-vascularization mechanisms depend on the hydrogel-aggregated structure that is controlled by elaboration conditions and possibly in relation with mechanical properties. Specific processing conditions induced micron-range capillary formation, which can be assimilated to colonization channels, also acting on the resorption scenario. - Highlights: • We elaborated physical chitosan hydrogels presenting tuneable biological properties. • Cell colonization mechanism depends on biological and mechanical hydrogel properties. • Increasing the degree of acetylation will reduce the bioresorption time. • Capillaries played a role of cell colonization pathways.

  4. Scanning electron microscopy reveals severe external root resorption in the large periapical lesion.

    Science.gov (United States)

    Ookubo, Kensuke; Ookubo, Atsushi; Tsujimoto, Masaki; Sugimoto, Kouji; Yamada, Shizuka; Hayashi, Yoshihiko

    2016-06-01

    The present study was designed to investigate the relationships between clinicopathological findings and the resorptive conditions of root apices of teeth with periodontitis. The samples included 21 root apices with large periapical radiolucent lesions. The preoperative computed tomography (CT) and intraoperative findings were correlated with the presence, extension, and the progression pattern of periapical resorption using a scanning electron microscope. The subjects' age, gender, chief complaint, type of tooth, percussion test results, size of periapical lesion using CT, and intraoperative findings were recorded. All apicoectomies were performed under an operative microscope for endodontic microsurgery. A significant large size was observed in cystic lesions compared with granulomatous lesions. The cementum surface at the periphery of the lesion was covered with globular structures (2-3 μm in diameter). Cementum resorption started as small defect formations at the surface. As the defect formation progressed, a lamellar structure appeared at the resorption area, and the size of globular structures became smaller than that of globules at the surface. Further resorption produced typical lacuna formation, which was particularly observed in fracture cases. The most morphologically severe destructive pattern of dentin resorption was observed in large cystic lesions. This study is the first report to elucidate the relationships between three clinical types of undesirable periapical lesions: (1) undertreatment, (2) periapical fracture, (3) macro-level resorption, and the microstructure of external root resorption including from small defects at the cementum surface to a significant destructive pattern inside the dentin. Microsc. Res. Tech. 79:495-500, 2016. © 2016 Wiley Periodicals, Inc. PMID:26957368

  5. Scanning electron microscopy of all parasitic stages of Haemaphysalis qinghaiensis Teng, 1980 (Acari: Ixodidae).

    Science.gov (United States)

    Chen, Ze; Li, Youquan; Liu, Zhijie; Ren, Qiaoyun; Ma, Miling; Luo, Jianxun; Yin, Hong

    2014-06-01

    Haemaphysalis qinghaiensis Teng (Acta Zootaxon Sin 5:144-149, 1980) is an endemic species in China. This tick species was first described based on engorged or semi-engorged specimens, and the drawings and description in words of morphological characteristics were poor. Therefore, the present study aims to redescribe morphological characteristics of all active stages of this tick species in detail by scanning electron microscopy. Additionally, a comparison between H. qinghaiensis and other sympatric Haemaphysalis species was also analyzed. Males of H. qinghaiensis can be distinguished from sympatric Haemaphysalis species by the following characters: palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; the tips of palpal segment III not so strongly recurved inward to become "pincerlike" and lacking dorsal spur; dental formula 5/5; lateral grooves enclose first festoon; coxa IV with a short, broadly triangular spur; tarsi somewhat humped; and spiracular plates long comma-shaped. Females of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; ventrointernal setae of palpal segment II thin, number <7; segment III of palpi lacking dorsal spur; dental formula 4/4; scutum subcircula; and tarsi somewhat humped. Nymphs of H. qinghaiensis can be distinguished from those of other species by palpi less salient laterally and curved in contour; dental formula 2/2; basis capituli rectangular, with distinct dorsal cornua, without ventral cornua; and spiracular plates with short and narrow dorsal prolongation. Larvae of H. qinghaiensis can be distinguished by palpi less salient laterally and curved in contour; basis capituli rectangular, without distinct cornua. PMID:24687283

  6. Effects of adhesion promoter on orthodontic bonding in fluorosed teeth: A scanning electron microscopy study

    Science.gov (United States)

    Gaur, Aditi; Maheshwari, Sandhya; Verma, Sanjeev Kumar; Tariq, Mohd.

    2016-01-01

    Introduction: The objectives of the present study were to elucidate the effects of fluorosis in orthodontic bonding and to evaluate the efficiency of an adhesion promoter (Assure Universal Bonding Resin) in bonding to fluorosed teeth. Materials and Methods: Extracted premolars were divided into two groups on the basis of Thylstrup and Fejerskov Index. Ten samples from each group were etched and evaluated for etching patterns using scanning electron microscope (SEM). The remaining samples were subdivided into four groups of 20 each on the basis of adhesives used: IA, IIA - Transbond XT and IB, IIB - Transbond XT plus Assure Universal Bonding Resin. Shear bond strength (SBS) was measured after 24 h using the universal testing machine. Adhesive remnant index (ARI) scores were recorded using SEM. Statistical analysis was conducted using a two-way analysis of variance, and Tukey's post hoc test was performed on SBS and ARI scores. Results: Similar etching patterns were observed in both fluorosed and nonfluorosed teeth. No significant differences were found in the SBS values observed in both groups (8.66 ± 3.19 vs. 8.53 ± 3.44, P = 1.000). Increase in SBS was observed when Assure Universal Bonding Resin was used. Higher ARI scores were observed when adhesion promoter was used for bonding. Conclusions: Mild-moderately fluorosed teeth etch in a manner similar to the nonfluorosed teeth. Similar bond strengths were achieved in fluorosed and nonfluorosed teeth when conventional composite was used. Use of adhesion promoter increases the bond strengths in both groups of teeth. PMID:27556020

  7. Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

    Energy Technology Data Exchange (ETDEWEB)

    Nishiyama, Hidetoshi, E-mail: hinishiy@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Koizumi, Mitsuru, E-mail: koizumi@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Ogawa, Koji, E-mail: kogawa@jeol.co.jp [JEOL Technics Ltd., 2-6-38 Musashino, Akishima, Tokyo 196-0021 (Japan); Kitamura, Shinich, E-mail: kitamura@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Konyuba, Yuji, E-mail: ykonyuub@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Watanabe, Yoshiyuki, E-mail: watanabeyoshiy@pref.yamagata.jp [Yamagata Research Institute of Technology, 2-2-1, Matsuei, Yamagata 990-2473 (Japan); Ohbayashi, Norihiko, E-mail: n.ohbayashi@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Fukuda, Mitsunori, E-mail: nori@m.tohoku.ac.jp [Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Suga, Mitsuo, E-mail: msuga@jeol.co.jp [JEOL Ltd., 3-1-2, Musashino, Akishima, Tokyo 196-8558 (Japan); Sato, Chikara, E-mail: ti-sato@aist.go.jp [Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-4, Umezono, Tsukuba 305-8568 (Japan)

    2014-12-15

    An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control.

  8. Aging effect on rabbit's lens fibers; A scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Sahar Mohammad Gamal

    2009-09-01

    Full Text Available The eye lens is a minute organ with complex structure that plays an indispensible role in the process of vision. It is composed mainly of modified epithelial cells that form a unique type of fibers. This study was performed to highlight the morphological variations of lens fibers in different age groups in rabbits' lenses. These variations in fibers' structure may have a great impact on the optical properties of the lens. Material and methods: Fifteen white male rabbits of different ages ranging from one month to four and half years were equally divided into three groups; young, adult and aged. Their lenses were dissected and processed for scanning electron microscopy. Gross lenses' diameters and A-P axis lengths were assessed using digitalized gross photomicrographs from dissecting microscope. Also, diameter of lens fibers was measured digitally for comparative purposes among the groups. Statistical analysis for significance of obtained data was performed using analysis of variance and student-T test. Results: The average equatorial diameter was 6.1% and 14.5% larger in adult and aged lenses than young ones. The average A-P axis length was 14.1% in adult and 21.7% in aged lenses more than in young lenses as well. Lens fibers exhibited some variations in the pattern of lateral interdigitations that became more branched with folding. Fiber diameter demonstrated an increase from young to adult lenses then a decrease in aged lens was noticed. Conclusion: Lens fibers undergo some morphological variations by age progression in the form of compaction in addition to changes in the appearance of ball and socket interdigitations. These changes can be correlated to some age-related optical disturbances as senile prespyopia and cataract. Recommendation: Age-related changes in the morphology of lens fibers should be considered in any experimental study including the lens to avoid interpretation bias and get more reliable results

  9. Atmospheric scanning electron microscope system with an open sample chamber: Configuration and applications

    International Nuclear Information System (INIS)

    An atmospheric scanning electron microscope (ASEM) with an open sample chamber and optical microscope (OM) is described and recent developments are reported. In this ClairScope system, the base of the open sample dish is sealed to the top of the inverted SEM column, allowing the liquid-immersed sample to be observed by OM from above and by SEM from below. The optical axes of the two microscopes are aligned, ensuring that the same sample areas are imaged to realize quasi-simultaneous correlative microscopy in solution. For example, the cathodoluminescence of ZnO particles was directly demonstrated. The improved system has (i) a fully motorized sample stage, (ii) a column protection system in the case of accidental window breakage, and (iii) an OM/SEM operation system controlled by a graphical user interface. The open sample chamber allows the external administration of reagents during sample observation. We monitored the influence of added NaCl on the random motion of silica particles in liquid. Further, using fluorescence as a transfection marker, the effect of small interfering RNA-mediated knockdown of endogenous Varp on Tyrp1 trafficking in melanocytes was examined. A temperature-regulated titanium ASEM dish allowed the dynamic observation of colloidal silver nanoparticles as they were heated to 240 °C and sintered. - Highlights: • Atmospheric SEM (ASEM) allows observation of samples in liquid or gas. • Open sample chamber allows in situ monitoring of evaporation and sintering processes. • in situ monitoring of processes during reagent administration is also accomplished. • Protection system for film breakage is developed for ASEM. • Usability of ASEM has been improved significantly including GUI control

  10. Comparative scanning electron microscopic study of the effect of different dental conditioners on dentin micromorphology

    Directory of Open Access Journals (Sweden)

    Alexandre Henrique Susin

    2008-04-01

    Full Text Available This study evaluated comparatively by scanning electron microscopy (SEM the effect of different dental conditioners on dentin micromorphology, when used according to the same protocol. Forty dentin sticks were obtained from 20 caries-free third human molars and were assigned to 4 groups corresponding to 3 conditioners (phosphoric acid 37%, Clearfil SE Bond and iBond and an untreated control group. After application of the conditioners, the specimens were immersed in 50% ethanol solution during 10 s, chemically fixed and dehydrated to prepare them to SEM analysis. In the control group, dentin surface was completely covered by smear layer and all dentinal tubules were occluded. In the phosphoric acid-etched group, dentin surface was completely clean and presented exposed dentinal tubule openings; this was the only group in which the tubules exhibited the funnel-shaped aspect. In the groups conditioned with Clearfil SE Bond primer and iBond, which are less acidic than phosphoric acid, tubule openings were occluded or partially occluded, though smear layer removal was observed. SE Bond was more efficient in removing the smear layer than iBond. In the Clearfil SE Bond group, the cuff-like aspect of peritubular dentin was more evident. It may be concluded all tested conditioners were able to change dentin morphology. However, it cannot be stated that the agent aggressiveness was the only cause of the micromorphological alterations because a single morphological pattern was not established for each group, but rather an association of different aspects, according to the aggressiveness of the tested conditioner.

  11. Bioresorption mechanisms of chitosan physical hydrogels: A scanning electron microscopy study

    International Nuclear Information System (INIS)

    Tissue-engineered biodegradable medical devices are widely studied and systems must present suitable balance between versatility and elaboration simplicity. In this work, we aim at illustrating that such equilibrium can be found by processing chitosan physical hydrogels without external cross-linker. Chitosan concentration, degree of acetylation, solvent composition, and neutralization route were modulated in order to obtain hydrogels exhibiting different physico-chemical properties. The resulting in vivo biological response was investigated by scanning electron microscopy. “Soft” hydrogels were obtained from chitosan of high degree of acetylation (35%) and by the neutralization with gaseous ammonia of a chitosan acetate aqueous solutions presenting low polymer concentration (Cp = 1.6% w/w). “Harder” hydrogels were obtained from chitosan with lower degree of acetylation (5%) and after neutralization in sodium hydroxide bath (1 M) of hydro-alcoholic chitosan solutions (50/50 w/w water/1,2-propanediol) with a polymer concentration of 2.5% w/w. Soft and hard hydrogels exhibited bioresorption times from below 10 days to higher than 60 days, respectively. We also evidenced that cell colonization and neo-vascularization mechanisms depend on the hydrogel-aggregated structure that is controlled by elaboration conditions and possibly in relation with mechanical properties. Specific processing conditions induced micron-range capillary formation, which can be assimilated to colonization channels, also acting on the resorption scenario. - Highlights: • We elaborated physical chitosan hydrogels presenting tuneable biological properties. • Cell colonization mechanism depends on biological and mechanical hydrogel properties. • Increasing the degree of acetylation will reduce the bioresorption time. • Capillaries played a role of cell colonization pathways

  12. Morphology and ultrastructure of Brachymystax lenok tsinlingensis spermatozoa by scanning and transmission electron microscopy.

    Science.gov (United States)

    Guo, Wei; Shao, Jian; Li, Ping; Wu, Jinming; Wei, Qiwei

    2016-08-01

    This study was conducted to investigate Brachymystax lenok tsinlingensis spermatozoa cell morphology and ultrastructure through scanning and transmission electron microscopy. Findings revealed that the spermatozoa can be differentiated into three major parts: a spherical head without an acrosome, a short mid-piece, and a long, cylindrical flagellum. The mean length of the spermatozoa was 36.11±2.84μm, with a spherical head length of 2.78±0.31μm. The mean anterior and posterior head widths were 2.20±0.42μm and 2.55±0.53μm, respectively. The nuclear fossa was positioned at the base of the nucleus that contained the anterior portion of flagellum and a centriolar complex (proximal and distal centrioles). The short mid-piece was located laterally to the nucleus and possessed just one spherical mitochondrion with a mean diameter of 0.65±0.14μm. The spermatozoa flagellum was long and cylindrical, and could be separated into two parts: a long main-piece and a short end-piece. The main piece of the flagellum had short irregular side-fins. The axoneme composed the typical '9+2' microtubular doublet structure and was enclosed by the cell membran e. This study confirmed that B. lenok tsinlingensis spermatozoa can be categorized as teleostean "Type I" spermatozoa; 'primitive' or 'ect-aquasperm type' spermatozoa. To the best of the authers knowledge, this was the first study conducted on the morphology and ultrastructure of B. lenok tsinlingensis spermatozoa. PMID:27375213

  13. Control electronics for a multi-laser/multi-detector scanning system

    Science.gov (United States)

    Kennedy, W.

    1980-01-01

    The Mars Rover Laser Scanning system uses a precision laser pointing mechanism, a photodetector array, and the concept of triangulation to perform three dimensional scene analysis. The system is used for real time terrain sensing and vision. The Multi-Laser/Multi-Detector laser scanning system is controlled by a digital device called the ML/MD controller. A next generation laser scanning system, based on the Level 2 controller, is microprocessor based. The new controller capabilities far exceed those of the ML/MD device. The first draft circuit details and general software structure are presented.

  14. Scanning electron microscopy at macromolecular resolution in low energy mode on biological specimens coated with ultra thin metal films.

    Science.gov (United States)

    Peters, K R

    1979-01-01

    In this report, conditions for attaining high resolution in scanning electron microscopy with soft biological specimens are described using the currently available high resolution scanning electron microscopes in emission mode of low energy electrons (secondary and charging electrons). Retinal rod outer segments, red blood cells, intestinal mucosa, and ferritin molecules were all used as biological test specimens. From uncoated specimens a new source of signal, referred to as a discharge signal, can provide a high yield of low energy electrons from an excitation area approximately the size of the beam's cross section. Additionally, under these conditions sufficient topographic contrast can be achieved by applying ultra thin metal coatins. A 0.5 nm thick gold film is found sufficient for generating the total signal, whereas increased coating thickness causes additional topographic background signal. However, a 2.0 nm film is needed for imaging surface details with the present instrument. Ultra thin, even, and grainless tantalum films have been found effective in eliminating the charging artifacts caused by external fields, and the decoration artifacts caused by crystal growth as seen in gold films. To improve, in high magnification work on ultra thin coated specimen, signal-to-noise ratio, methods for obtaining saturation of the signal with discharge electrons are shown. The necessity of confirming the information obtained in SEM by independent techniques (TEM of stereo-replicas or ultra thin sections) is discussed. PMID:392703

  15. An endolithic microbial community in dolomite rock in central Switzerland: characterization by reflection spectroscopy, pigment analyses, scanning electron microscopy, and laser scanning microscopy.

    Science.gov (United States)

    Horath, T; Neu, T R; Bachofen, R

    2006-04-01

    A community of endolithic microorganisms dominated by phototrophs was found as a distinct band a few millimeters below the surface of bare exposed dolomite rocks in the Piora Valley in the Alps. Using in situ reflectance spectroscopy, we detected chlorophyll a (Chl a), phycobilins, carotenoids, and an unknown type of bacteriochlorophyll-like pigment absorbing in vivo at about 720 nm. In cross sections, the data indicated a defined distribution of different groups of organisms perpendicular to the rock surface. High-performance liquid chromatography analyses of pigments extracted with organic solvents confirmed the presence of two types of bacteriochlorophylls besides chlorophylls and various carotenoids. Spherical organisms of varying sizes and small filaments were observed in situ with scanning electron microscopy and confocal laser scanning microscopy (one- and two-photon technique). The latter allowed visualization of the distribution of phototrophic microorganisms by the autofluorescence of their pigments within the rock. Coccoid cyanobacteria of various sizes predominated over filamentous ones. Application of fluorescence-labeled lectins demonstrated that most cyanobacteria were embedded in an exopolymeric matrix. Nucleic acid stains revealed a wide distribution of small heterotrophs. Some biological structures emitting a green autofluorescence remain to be identified. PMID:16598629

  16. Ku/Ka/W-band Antenna for Electronically-Scanned Cloud and Precipitation Radar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of the key antenna technologies for Tri-band (Ku/Ka/W), scanning precipitation and cloud radar is a required milestone in preparation for one or more...

  17. SYSTEMATIC SCANNING ELECTRON MICROSCOPY TECHNIQUE FOR EVALUATING COMBINED BIOLOIGCAL/GRANULAR ACTIVATED CARBON TREATMENT PROCESSES

    Science.gov (United States)

    A systematic scanning election microscope analytical technique has been developed to examine granular activated carbon used a a medium for biomass attachment in liquid waste treatment. The procedure allows for the objective monitoring, comparing, and trouble shooting of combined ...

  18. Microdialysis of cytokines: methodological considerations, scanning electron microscopy, and determination of relative recovery.

    Science.gov (United States)

    Helmy, Adel; Carpenter, Keri L H; Skepper, Jeremy N; Kirkpatrick, Peter J; Pickard, John D; Hutchinson, Peter J

    2009-04-01

    Cerebral microdialysis is a monitoring technique with expanding clinical and research utility following traumatic brain injury. This study's aim was to determine the relative recovery for 12 cytokines using both crystalloid (CNS perfusion fluid) and colloid (CNS perfusion fluid supplemented with 3.5% human serum albumin) perfusate. Six CMA71 microdialysis catheters (nominal molecular weight cut-off 100 kDa) were perfused in vitro with either crystalloid or colloid and the relative recovery (%) determined for the cytokines as follows (crystalloid/colloid perfusate): IL-1alpha (50.6/48), IL-1beta (34.6/38.4), IL-1ra (21.9/38.4), IL-2 (17.1/52.8), IL-4 (26/56.7), IL-6 (9.8/25.5), IL-8 (47.7/73.4), IL-10 (2.9/8.7), IL-17 (14.4/43.7), TNF-alpha (4.4/31.2), MIP-1alpha (31.8/55.6), and MIP-1beta (31.9/50.1). The colloid perfusate significantly improved relative recovery for nine of these cytokines ( p recovery was related to apparent molecular weight of cytokine and to isoelectric point (pI), a surrogate marker of hydrophilicity. The mean fluid recovery for crystalloid and colloid perfusate was 92% and 145%, respectively. Scanning electron microscopy was utilized to investigate the ultrastructure of microdialysis membranes: (1) 20-kDa membrane, (2) 100-kDa membrane, and (3) ex vivo 100-kDa membrane. The 100-kDa membranes possessed multiple large cavities and the catheter examined after use in human brain clearly demonstrated cellular debris within the pores of the membrane. While colloid perfusate improves relative recovery, it causes a net influx of fluid into the microdialysis catheter, potentially dehydrating the extracellular space. This study is the first to systematically determine relative recovery in vitro for a wide range of cytokines. The two forms of perfusion fluid require direct comparison in vivo. PMID:19196175

  19. Scanning electron microscopy of chronically implanted intracortical microelectrode arrays in non-human primates

    Science.gov (United States)

    Barrese, James C.; Aceros, Juan; Donoghue, John P.

    2016-04-01

    Objective. Signal attenuation is a major problem facing intracortical sensors for chronic neuroprosthetic applications. Many studies suggest that failure is due to gliosis around the electrode tips, however, mechanical and material causes of failure are often overlooked. The purpose of this study was to investigate the factors contributing to progressive signal decline by using scanning electron microscopy (SEM) to visualize structural changes in chronically implanted arrays and histology to examine the tissue response at corresponding implant sites. Approach. We examined eight chronically implanted intracortical microelectrode arrays (MEAs) explanted from non-human primates at times ranging from 37 to 1051 days post-implant. We used SEM, in vivo neural recordings, and histology (GFAP, Iba-1, NeuN). Three MEAs that were never implanted were also imaged as controls. Main results. SEM revealed progressive corrosion of the platinum electrode tips and changes to the underlying silicon. The parylene insulation was prone to cracking and delamination, and in some instances the silicone elastomer also delaminated from the edges of the MEA. Substantial tissue encapsulation was observed and was often seen growing into defects in the platinum and parylene. These material defects became more common as the time in vivo increased. Histology at 37 and 1051 days post-implant showed gliosis, disruption of normal cortical architecture with minimal neuronal loss, and high Iba-1 reactivity, especially within the arachnoid and dura. Electrode tracts were either absent or barely visible in the cortex at 1051 days, but were seen in the fibrotic encapsulation material suggesting that the MEAs were lifted out of the brain. Neural recordings showed a progressive drop in impedance, signal amplitude, and viable channels over time. Significance. These results provide evidence that signal loss in MEAs is truly multifactorial. Gliosis occurs in the first few months after implantation but does

  20. Study Effect of Carbon: Nitrogen Ratio on the Minerals Weathering by Using Scanning Electron Microscope

    Directory of Open Access Journals (Sweden)

    A. K. Ali

    2013-09-01

    Full Text Available This study conducted to investigate the effect of soil C:N ratio under different tree types characterized by similarity in all soil forming factors (climate, parent material, topography, organisms ,time located north of Iraq , difference between them was just in the composition rate of organic matter produce by different tree types which due to variation in c:n ratio, some clay fraction of studied pedons in surface and subsurface horizon has been tested under scanning electron microscope and x-ray diffraction, the result of SEM emages showed that the green grain forest was the higher effected soil through weathering signs which was very clear , clay samples showed breakness of mineral layers and edges also the minerals appear in different size and shapes and that correlated with decrement in C:N ratio in tree types , the results showed there is series of changes in mineral morphological features , then mineral particles surfaces in green grain and pine forest appear irregular and complicated especially in pine forest samples as well as the minerals in green grain forest appear spongy like shape which due to swelling and expansion sequence for mineral interlayer. images for wild pears and oak forests showed the mineral surfaces was in the exfoliation state where the exfoliation tracks appear very clear whereas some of them exposed to edge weathering indicated by appearance of edges in pale color which can recognize from surface zone which caused by bleaching process resulting from interlayer cation removal by the weathering process which probably be potassium or iron absence of complication state and restricted in exfoliation process associated with edge weathering of exfoliated surfaces explain weathering intensity reduction as compared with green grain and pine forest and less weathering intensity found in almond tree type which was more C:N ratio value. If we focused on the C:N ration results we can recognize the variation in this value

  1. Clinical applications of scanning electron microscopy and energy dispersive X-ray analysis in dermatology--an up-date

    International Nuclear Information System (INIS)

    Dermatological papers comprising scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis data published 1983 through 1986 in international journals are reviewed, as an update to our 1984 paper on Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology. The present paper not only deals with a review of recent publications in this area but also presents the application of microincineration to hair and cryosectioned freeze-dried skin specimens. Examples of the increased contrast obtained in hair cross sections are presented and a discussion on the feasibility of microincineration at analysis of hair and skin cross sections is given. Particle probe analysis (EDX: energy dispersive X-ray analysis and PMP: proton microprobe analysis) as applied to hair and skin samples are presented with stress put on the proton probe analysis. The complementarity of EDX and PMP is demonstrated and future applications are suggested. 75 references

  2. Scanning electron microscopic study of the surface of feline gastric epithelium: a simple method of removing the coating material.

    Science.gov (United States)

    Al-Tikriti, M; Henry, R W; Al-Bagdadi, F K; Hoskins, J; Titkemeyer, C

    1986-01-01

    Scanning electron microscopic examination of the gastric surface epithelial cells is often hindered by the presence of a coating material. Several methods for removal of coating material on feline gastric mucosa were utilized. The cleansed tissues were evaluated using the scanning electron microscope to assess damage caused by the use of various cleansing methods to surface epithelial cells. The stretched stomach washed several times, including rubbing the mucosal surface with gloved fingers, yielded the best results with no apparent damage to the surface epithelial cells. Flushing unstretched stomachs with saline only did not adequately remove coating material. Flushing unstretched stomachs with saline while stroking the surface with a cotton tipped applicator stick removed debris but damaged the surface epithelium.

  3. Electronic “Edge” State on Molybdenite Basal Plane Observed by Ultrahigh-Vacuum Scanning Tunneling Microscopy and Spectroscopy

    Science.gov (United States)

    Komiyama, Masaharu; Tomita, Hiroyuki; Yoda, Eisuke

    2007-09-01

    An electronic state heretofore unreported has been found on a cleaved basal plane of a natural molybdenite (MoS2) single crystal by ultrahigh-vacuum scanning tunneling microscopy (UHV-STM), and examined in detail both by STM and scanning tunneling spectroscopy (STS). The new electronic state resides on the edge of the upper terrace of MoS2(0001), manifesting itself in the form of bright ridges with a width of ca. 4 nm along the step edges in negatively sample-biased STM images. This ridge structure is nonexistent in STM images taken with positive sample biases. STS showed that the local density of states (LDOS) on such ridge structures is much higher than that on the terraces in the range of 0.2-1.2 eV below the Fermi edge. The nature and origin of this high LDOS at the step edges are discussed.

  4. Scanning Electron Microscope Studies of Interactions between Agaricus bisporus (Lang) Sing Hyphae and Bacteria in Casing Soil

    OpenAIRE

    Masaphy, Segula; Levanon, D.; Tchelet, R.; Henis, Y.

    1987-01-01

    Relationships between the hyphae of Agaricus bisporus (Lang) Sing and bacteria from the mushroom bed casing layer were examined with a scanning electron microscope. Hyphae growing in the casing layer differed morphologically from compost-grown hyphae. Whereas the compost contained thin single hyphae surrounded by calcium oxalate crystals, the casing layer contained mainly wide hyphae or mycelial strands without crystals. The bacterial population in the hyphal environment consisted of several ...

  5. Quasi-Steady-State Voltammetry of Rapid Electron Transfer Reactions at the Macroscopic Substrate of the Scanning Electrochemical Microscope

    OpenAIRE

    Nioradze, Nikoloz; Kim, Jiyeon; Amemiya, Shigeru

    2010-01-01

    We report on novel theory and experiment for scanning electrochemical microscopy (SECM) to enable quasi-steady-state voltammetry of rapid electron transfer (ET) reactions at macroscopic substrates. With this powerful approach, substrate potential is cycled widely across the formal potential of a redox couple while the reactant or product of a substrate reaction is amperometrically detected at the tip in the feedback or substrate generation/tip collection mode, respectively. The plot of tip cu...

  6. Posterior spiracles of fourth instar larvae of four species of phlebotomine sand flies (Diptera: Psychodidae under scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Pessoa Felipe Arley Costa

    2000-01-01

    Full Text Available In the present study, posterior spiracles of laboratory-reared fourth instar larvae of Lutzomyia longipalpis, L. migonei, L. lenti, and L. whitmani (Diptera: Psychodidae of the State of Ceará, Brazil, were examined under scanning electron microscopy. The number of papillae of spiracles examined varied according to the species examined, but no intraspecific differences were found. The importance of this structure to sand fly larva identification and phylogeny is commented.

  7. Minimal Apical Enlargement for Penetration of Irrigants to the Apical Third of Root Canal System: A Scanning Electron Microscope Study

    OpenAIRE

    P. Srikanth; Krishna, Amaravadi Gopi; Srinivas, Siva; Reddy, E Sujayeendranatha; Battu, Someshwar; Aravelli, Swathi

    2015-01-01

    Background: The aim of this study was to determine minimal apical enlargement for irrigant penetration into apical third of root canal system using scanning electron microscope (SEM). Materials and Methods: Distobuccal canals of 40 freshly extracted human maxillary first molar teeth were instrumented using crown-down technique. The teeth were divided into four test groups according to size of their master apical file (MAF) (#20, #25, #30, #35 0.06% taper), and two control groups. After final ...

  8. Scanning electron microscopic (Sem studies on fourth instar larva and pupa of Anopheles (Cellia stephensi Liston (Anophelinae: Culicidae

    Directory of Open Access Journals (Sweden)

    Jagbir Singh Kirti

    2014-12-01

    Full Text Available Anopheles (Cellia stephensi Liston is a major vector species of malaria in Indian subcontinent. Taxonomists have worked on its various morphological aspects and immature stages to explore additional and new taxonomic attributes. Scanning electron microscopic (SEM studies have been conducted on the fourth instar larva and pupa of An. stephensi to find additional taxonomic features for the first time from Punjab state.

  9. Fast scanning heterodyne receiver for the measurement of the time evolution of the electron temperature profile on TFTR

    International Nuclear Information System (INIS)

    Two fast scanning heterodyne receivers, swept between 75 to 110 GHz and 110 to 170 GHz in 2 msec every 4 msec, were developed to measure the electron cyclotron emission on the horizontal midplane of the Tokamak Fusion Test Reactor (TFTR) plasma. An absolute, in situ calibration technique enables the determination of the profile of the plasma electron temperature from the cyclotron emission intensity. The 4 msec repetition rate of the receiver allowed the resolution of sawtooth fluctuations of temperature, whose period was 10 to 100 msec, in profiles with central temperatures of 1 to 2.5 keV

  10. Fast scanning heterodyne receiver for the measurement of the time evolution of the electron temperature profile on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, G.; Efthimion, P.; McCarthy, M.; Arunasalam, V.; Bitzer, R.; Bryer, J.; Cutler, R.; Fredd, E.; Goldman, M.A.; Kaufman, D.

    1984-06-01

    Two fast scanning heterodyne receivers, swept between 75 to 110 GHz and 110 to 170 GHz in 2 msec every 4 msec, were developed to measure the electron cyclotron emission on the horizontal midplane of the Tokamak Fusion Test Reactor (TFTR) plasma. An absolute, in situ calibration technique enables the determination of the profile of the plasma electron temperature from the cyclotron emission intensity. The 4 msec repetition rate of the receiver allowed the resolution of sawtooth fluctuations of temperature, whose period was 10 to 100 msec, in profiles with central temperatures of 1 to 2.5 keV.

  11. Performance of a slow-scan CCD camera for macromolecular imaging in a 400 kV electron cryomicroscope.

    Science.gov (United States)

    Sherman, M B; Brink, J; Chiu, W

    1996-04-01

    The feasibility and limitations of a 1024 x 1024 slow-scan charge-coupled device (CCD) camera were evaluated for imaging in a 400kV electron cryomicroscope. Catalase crystals and amorphous carbon film were used as test specimens. Using catalase crystals, it was found that the finite (24 microns) pixel size of the slow-scan CCD camera governs the ultimate resolution in the acquired images. For instance, spot-scan images of ice-embedded catalase crystals showed resolutions of 8 A and 4 A at effective magnifications of 67,000 x and 132,000 x, respectively. Using an amorphous carbon film, the damping effect of the modulation transfer function (MTF) of the slow-scan CCD camera on the specimen's Fourier spectrum relative to that of the photographic film was evaluated. The MTF of the slow-scan CCD camera fell off more rapidly compared to that of the photographic film and reached the value of 0.2 at the Nyquist frequency. Despite this attenuation, the signal-to-noise ratio of the CCD data, as determined from reflections of negatively-stained catalase crystals, was found to decrease to approximately 50% of that of photographic film data. The phases computed from images of the same negatively-stained catalase crystals recorded consecutively on both the slow-scan CCD camera and photographic film were found to be comparable to each other within 12 degrees. Ways of minimizing the effect of the MTF of the slow-scan CCD camera on the acquired images are also presented. PMID:8858867

  12. Scanning electron microscopy combined with image processing technique: Microstructure and texture analysis of legumes and vegetables for instant meal.

    Science.gov (United States)

    Pieniazek, Facundo; Messina, Valeria

    2016-04-01

    Development and innovation of new technologies are necessary especially in food quality; due that most instrumental technique for measuring quality properties involves a considerable amount of manual work. Image analysis is a technique that allows to provide objective evaluations from digitalized images that can estimate quality parameters for consumer's acceptance. The aim of the present research was to study the effect of freeze drying on the microstructure and texture of legume and vegetables using scanning electron microscopy at different magnifications' combined with image analysis. Cooked and cooked freeze dried rehydrated legumes and vegetables were analyzed individually by scanning electron microscopy at different magnifications' (250, 500, and 1000×).Texture properties were analyzed by texture analyzer and image analysis. Significant differences (P Lentils: contrast, correlation, energy, homogeneity, and entropy for hardness, adhesiviness, gumminess, and chewiness; Potato and carrots: contrast, energy, homogeneity and entropy for adhesiviness, chewiness, hardness, cohesiviness, and resilence. Results revealed that combing scanning electron microscopy with image analysis can be a useful tool to analyze quality parameters in legumes and vegetables. PMID:26789426

  13. Mass measurement with the electron microscope. [Application of scanning transmission electron microscopy in molecular weight determinations of fd phage

    Energy Technology Data Exchange (ETDEWEB)

    Wall, J.S.

    1979-01-01

    The use of electron scattering measurements performed in the electron microscope as a means of measurement of particle molecular weight is described. Various potential sources of errors are identified and estimated where possible. Specimen preparation and observation conditions to minimize errors are described. The fd phage is presented as an example of analysis and an illustration of the accuracy obtainable at low dose.

  14. Luneburg lens with extended flat focal surface for electronic scan applications.

    Science.gov (United States)

    Li, Ying; Zhu, Qi

    2016-04-01

    Luneburg lens with flat focal surface has been developed to work together with planar antenna feeds for beam steering applications. According to our analysis of the conventional flattened Luneburg lens, it cannot accommodate enough feeding elements which can cover its whole scan range with half power beamwidths (HPBWs). In this paper, a novel Luneburg lens with extended flat focal surface is proposed based on the theory of Quasi-Conformal Transformation Optics (QCTO), with its beam steering features reserved. To demonstrate this design, a three-dimensional (3D) prototype of this novel extend-flattened Luneburg lens working at Ku band is fabricated based on 3D printing techniques, whose flat focal surface is attached to a 9-element microstrip antenna array to achieve different scan angles. Our measured results show that, with different antenna elements being fed, the HPBWs can cover the whole scan range.

  15. Whole-cell imaging of the budding yeast Saccharomyces cerevisiae by high-voltage scanning transmission electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Kazuyoshi, E-mail: kazum@nips.ac.jp [National Institute for Physiological Sciences, Okazaki, Aichi 444-8585 (Japan); Esaki, Masatoshi; Ogura, Teru [Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811 (Japan); Arai, Shigeo; Yamamoto, Yuta; Tanaka, Nobuo [Ecotopia Science Institute, Nagoya University, Nagoya, Aichi 464-8603 (Japan)

    2014-11-15

    Electron tomography using a high-voltage electron microscope (HVEM) provides three-dimensional information about cellular components in sections thicker than 1 μm, although in bright-field mode image degradation caused by multiple inelastic scattering of transmitted electrons limit the attainable resolution. Scanning transmission electron microscopy (STEM) is believed to give enhanced contrast and resolution compared to conventional transmission electron microscopy (CTEM). Samples up to 1 μm in thickness have been analyzed with an intermediate-voltage electron microscope because inelastic scattering is not a critical limitation, and probe broadening can be minimized. Here, we employed STEM at 1 MeV high-voltage to extend the useful specimen thickness for electron tomography, which we demonstrate by a seamless tomographic reconstruction of a whole, budding Saccharomyces cerevisiae yeast cell, which is ∼3 μm in thickness. High-voltage STEM tomography, especially in the bright-field mode, demonstrated sufficiently enhanced contrast and intensity, compared to CTEM tomography, to permit segmentation of major organelles in the whole cell. STEM imaging also reduced specimen shrinkage during tilt-series acquisition. The fidelity of structural preservation was limited by cytoplasmic extraction, and the spatial resolution was limited by the relatively large convergence angle of the scanning probe. However, the new technique has potential to solve longstanding problems of image blurring in biological specimens beyond 1 μm in thickness, and may facilitate new research in cellular structural biology. - Highlights: • High voltage TEM and STEM tomography were compared to visualize whole yeast cells. • 1-MeV STEM-BF tomography had significant improvements in image contrast and SNR. • 1-MeV STEM tomography showed less specimen shrinkage than the TEM tomography. • KMnO{sub 4} post-treatment permitted segmenting the major cellular components.

  16. Whole-cell imaging of the budding yeast Saccharomyces cerevisiae by high-voltage scanning transmission electron tomography

    International Nuclear Information System (INIS)

    Electron tomography using a high-voltage electron microscope (HVEM) provides three-dimensional information about cellular components in sections thicker than 1 μm, although in bright-field mode image degradation caused by multiple inelastic scattering of transmitted electrons limit the attainable resolution. Scanning transmission electron microscopy (STEM) is believed to give enhanced contrast and resolution compared to conventional transmission electron microscopy (CTEM). Samples up to 1 μm in thickness have been analyzed with an intermediate-voltage electron microscope because inelastic scattering is not a critical limitation, and probe broadening can be minimized. Here, we employed STEM at 1 MeV high-voltage to extend the useful specimen thickness for electron tomography, which we demonstrate by a seamless tomographic reconstruction of a whole, budding Saccharomyces cerevisiae yeast cell, which is ∼3 μm in thickness. High-voltage STEM tomography, especially in the bright-field mode, demonstrated sufficiently enhanced contrast and intensity, compared to CTEM tomography, to permit segmentation of major organelles in the whole cell. STEM imaging also reduced specimen shrinkage during tilt-series acquisition. The fidelity of structural preservation was limited by cytoplasmic extraction, and the spatial resolution was limited by the relatively large convergence angle of the scanning probe. However, the new technique has potential to solve longstanding problems of image blurring in biological specimens beyond 1 μm in thickness, and may facilitate new research in cellular structural biology. - Highlights: • High voltage TEM and STEM tomography were compared to visualize whole yeast cells. • 1-MeV STEM-BF tomography had significant improvements in image contrast and SNR. • 1-MeV STEM tomography showed less specimen shrinkage than the TEM tomography. • KMnO4 post-treatment permitted segmenting the major cellular components

  17. Identification of magnetic Fe-Ti oxides in marine sediments by electron backscatter diffraction in scanning electron microscopy

    NARCIS (Netherlands)

    Franke, C.; Pennock, G.M.; Drury, M.R.; Engelmann, R.; Lattard, D.; Garming, J.F.L.; Dobeneck, T. von; Dekkers, M.J.

    2007-01-01

    In paleomagnetic and environmental magnetic studies the magnetomineralogical identification is usually based on a set of rock magnetic parameters, complemented by crystallographic and chemical information retrieved from X-ray diffraction (XRD), (electron) microscopy or energy dispersive spectroscopy

  18. Nanoscale imaging of untreated mammalian cells in a medium with low radiation damage using scanning electron-assisted dielectric microscopy

    Science.gov (United States)

    Okada, Tomoko; Ogura, Toshihiko

    2016-07-01

    Imaging of untreated living cells in a medium at a nanometre-scale resolution under physiological conditions is a significant challenge. Scanning electron microscopy (SEM) is widely used to observe cells in various atmospheric holders or special equipment. However, untreated biological specimens in aqueous solution generally incur heavy radiation damage from the direct electron beam (EB); and these images exhibit very poor contrast. Therefore, a new method for generating high-contrast images of living cells under physiological conditions without radiation damage has been strongly desired. Here, we demonstrate the first nanoscale observation of living cultured mammalian cells using our newly developed scanning-electron assisted dielectric microscopy (SE-ADM) method with a culture dish holder. Using the difference in relative permittivity between water and specimens, our SE-ADM system aids in the visualisation of untreated biological samples in aqueous solution. In addition, specimens incurred only a low level of radiation damage because the tungsten (W)-coated silicon nitride (SiN) film absorbs irradiated electrons. Untreated cells and organelles are clearly visible in high-contrast and high-resolution images without staining and fixation. Furthermore, our method enables the detection of changes in organelle structures within cells via time-lapse imaging with minimal radiation damage.

  19. Nanoscale imaging of untreated mammalian cells in a medium with low radiation damage using scanning electron-assisted dielectric microscopy

    Science.gov (United States)

    Okada, Tomoko; Ogura, Toshihiko

    2016-01-01

    Imaging of untreated living cells in a medium at a nanometre-scale resolution under physiological conditions is a significant challenge. Scanning electron microscopy (SEM) is widely used to observe cells in various atmospheric holders or special equipment. However, untreated biological specimens in aqueous solution generally incur heavy radiation damage from the direct electron beam (EB); and these images exhibit very poor contrast. Therefore, a new method for generating high-contrast images of living cells under physiological conditions without radiation damage has been strongly desired. Here, we demonstrate the first nanoscale observation of living cultured mammalian cells using our newly developed scanning-electron assisted dielectric microscopy (SE-ADM) method with a culture dish holder. Using the difference in relative permittivity between water and specimens, our SE-ADM system aids in the visualisation of untreated biological samples in aqueous solution. In addition, specimens incurred only a low level of radiation damage because the tungsten (W)-coated silicon nitride (SiN) film absorbs irradiated electrons. Untreated cells and organelles are clearly visible in high-contrast and high-resolution images without staining and fixation. Furthermore, our method enables the detection of changes in organelle structures within cells via time-lapse imaging with minimal radiation damage. PMID:27375121

  20. Two-photon-induced hot-electron transfer to a single molecule in a scanning tunneling microscope

    International Nuclear Information System (INIS)

    The junction of a scanning tunneling microscope (STM) operating in the tunneling regime was irradiated with femtosecond laser pulses. A photoexcited hot electron in the STM tip resonantly tunnels into an excited state of a single molecule on the surface, converting it from the neutral to the anion. The electron-transfer rate depends quadratically on the incident laser power, suggesting a two-photon excitation process. This nonlinear optical process is further confirmed by the polarization measurement. Spatial dependence of the electron-transfer rate exhibits atomic-scale variations. A two-pulse correlation experiment reveals the ultrafast dynamic nature of photoinduced charging process in the STM junction. Results from these experiments are important for understanding photoinduced interfacial charge transfer in many nanoscale inorganic-organic structures.

  1. The Effect of Citrullus colocynthis Pulp Extract on the Liver of Diabetic Rats a Light and Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Mohammad Khalil

    2010-01-01

    Full Text Available Problem statement: The goal of the current investigation was to clarify the effects of Citrullus colocynthis pulp extract on the structure of the liver of diabetic rats at both light and scanning electron microscopic levels. Approach: Forty-eight adult male albino rats were equally allocated into four groups: Group1: control, Group 2: Citrullus colocynthis-treated, Group 3: diabetic rats and Group4: diabetic rats treated with Citrullus colocynthis. All treatments were administered via an intragastric tube. Diabetes was induced in the rats of groups 3 and 4 by an intraperitoneal injection with alloxan. Results: The liver of Citrullus colocynthis-treated rats revealed minor histological changes versus the control animals. In group 3 animals, diabetes caused degenerative alterations in the form of disorganization of the hepatic cords, cytoplasmic vacuolization and pyknosis of the nuclei of hepatocytes and inflammatory cell infiltration. Scanning electron microscope examination of these livers revealed numerous lipid droplets within hepatocytes, damaged blood sinusoids and hemorrhage of erythrocytes between hepatocytes and inside Disse’s spaces. On the other hand, the normal histological and scanning ultrastructural features were nearly resumed in the liver of diabetic rats treated with Citrullus colocynthis pulp extract. Conclusion: The present study proved a lessening effect of Citrullus colocynthis pulp extract on the liver of diabetic rats. In light of these advantageous influences, it is advisable to widen the scale of its use in a trial to alleviate the diabetic hepatic adverse effects.

  2. Scanning electron microscopy of the vestibular end organs. [morphological indexes of inner ear anatomy and microstructure

    Science.gov (United States)

    Lindeman, H. H.; Ades, H. W.; West, R. W.

    1973-01-01

    The vestibular end organs, after chemical fixation, were freeze dried, coated with gold and palladium, and studied in the scanning microscope. Scanning microscopy gives a good three dimensional view of the sensory areas and allows study of both gross anatomy and microstructures. Cross anatomical features of the structure of the ampullae are demonstrated. The form of the statoconia in different species of animals is shown. New aspects of the structure of the sensory hairs are revealed. The hair bundles in the central areas of the cristae and in the striola of the maculae differ structurally from the hair bundles at the periphery of the sensory regions. Furthermore, some hair bundles consisting of very short stereocilia were observed. The relationship between the cupula and the statoconial membrane to the epithelial surface is discussed.

  3. Nuclear and electronic resonance spectroscopy of single molecules by radio-frequency scanning tunnelling microscopy

    OpenAIRE

    Müllegger, Stefan; Tebi, Stefano; Das, Amal K.; Schöfberger, Wolfgang; Faschinger, Felix; Koch, Reinhold

    2014-01-01

    The ongoing miniaturization in nanoscience and -technology challenges the sensitivity and selectivity of experimental analysis methods to the ultimate level of single atoms and molecules. A promising new approach, addressed here, focuses on the combination of two well-established complementary techniques that have proven to be very successful in their own fields: (i) low-temperature scanning tunneling microscopy (STM), offering high spatial resolution for imaging and spectroscopy together wit...

  4. Evaluation of gas chromatography - electron ionization - full scan high resolution Orbitrap mass spectrometry for pesticide residue analysis.

    Science.gov (United States)

    Mol, Hans G J; Tienstra, Marc; Zomer, Paul

    2016-09-01

    Gas chromatography with electron ionization and full scan high resolution mass spectrometry with an Orbitrap mass analyzer (GC-EI-full scan Orbitrap HRMS) was evaluated for residue analysis. Pesticides in fruit and vegetables were taken as an example application. The relevant aspects for GC-MS based residue analysis, including the resolving power (15,000 to 120,000 FWHM at m/z 200), scan rate, dynamic range, selectivity, sensitivity, analyte identification, and utility of existing EI-libraries, are assessed and discussed in detail. The optimum acquisition conditions in full scan mode (m/z 50-500) were a resolving power of 60,000 and an automatic-gain-control target value of 3E6. These conditions provided (i) an optimum mass accuracy: within 2 ppm over a wide concentration range, with/without matrix, enabling the use of ±5 ppm mass extraction windows (ii) adequate scan speed: minimum 12 scans/peak, (iii) an intra-scan dynamic range sufficient to achieve LOD/LOQs ≤0.5 pg in fruit/vegetable matrices (corresponding to ≤0.5 μg kg(-1)) for most pesticides. EI-Orbitrap spectra were consistent over a very wide concentration range (5 orders) with good match values against NIST (EI-quadrupole) spectra. The applicability for quantitative residue analysis was verified by validation of 54 pesticides in three matrices (tomato, leek, orange) at 10 and 50 μg/kg. The method involved a QuEChERS-based extraction with a solvent switch into iso-octane, and 1 μL hot splitless injection into the GC-HRMS system. A recovery between 70 and 120% and a repeatability RSD pesticides could be identified according to the applicable EU criteria for GC-HRMS (SANTE/11945/2015). GC-EI-full scan Orbitrap HRMS was found to be highly suited for quantitative pesticide residue analysis. The potential of qualitative screening to extend the scope makes it an attractive alternative to GC-triple quadrupole MS. PMID:27543025

  5. A versatile LabVIEW and FPGA-based scanned probe microscope for in-operando electronic device characterization

    CERN Document Server

    Berger, Andrew J; Jacob, Jan; Young, Justin R; Lewis, Jim; Wenzel, Lothar; Bhallamudi, Vidya P; Johnston-Halperin, Ezekiel; Pelekhov, Denis V; Hammel, P Chris

    2014-01-01

    Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In-operando characterization of such devices by scanned probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanned probe microscope (SPM) which is capable of both standard force imaging (atomic, magnetic, electrostatic) and simultaneous electrical transport measurements. We utilize flexible and inexpensive FPGA (field programmable gate array) hardware and a custom software framework developed in National Instrument's LabVIEW environment to perform the various aspects of microscope operation and device measurement. The FPGA-based approach enables sensitive, real-time cantilever frequency-shift detection. Using this system, we demonstrate electrostatic force microscopy of an electrically-biased graphene FET device. The c...

  6. X-Band Rapid-Scan Electron Paramagnetic Resonance of Radiation-Induced Defects in Tooth Enamel.

    Science.gov (United States)

    Yu, Zhelin; Romanyukha, Alexander; Eaton, Sandra S; Eaton, Gareth R

    2015-08-01

    X-band rapid-scan electron paramagnetic resonance (EPR) spectra from tooth enamel samples irradiated with doses of 0.5, 1 and 10 Gy had substantially improved signal-to-noise relative to conventional continuous wave EPR. The radiation-induced signal in a 60 mg of a tooth enamel sample irradiated with a 0.5 Gy dose was readily characterized in spectra recorded with 34 min data acquisition times. The coefficient of variance of the calculated dose for a 1 Gy irradiated sample, based on simulation of the first-derivative spectra for three replicates as the sum of native and radiation-induced signals, was 3.9% for continuous wave and 0.4% for rapid scan.

  7. Scanning probe microscopy study of electronic properties of oligothiophenes thin films

    OpenAIRE

    Afsharimani, Nasima Sadat

    2013-01-01

    Organic semiconductors have been extensively studied due to their potential applications in cheap, flexible, and large area electronic devices. Among potential organic semiconductors, alkyl-substituted oligothiophenes, that are able to self-assemble in close-packed crystalline structures, have shown promising high field-effect mobilities. The objectives of this thesis were to microscopically study the electronic properties of three semiconducting alkyl-substituted oligothiophenes, α,α’-diocty...

  8. Combining scanning tunneling microscopy and synchrotron radiation for high-resolution imaging and spectroscopy with chemical, electronic, and magnetic contrast

    International Nuclear Information System (INIS)

    The combination of high-brilliance synchrotron radiation with scanning tunneling microscopy opens the path to high-resolution imaging with chemical, electronic, and magnetic contrast. Here, the design and experimental results of an in-situ synchrotron enhanced x-ray scanning tunneling microscope (SXSTM) system are presented. The system is designed to allow monochromatic synchrotron radiation to enter the chamber, illuminating the sample with x-ray radiation, while an insulator-coated tip (metallic tip apex open for tunneling, electron collection) is scanned over the surface. A unique feature of the SXSTM is the STM mount assembly, designed with a two free-flex pivot, providing an angular degree of freedom for the alignment of the tip and sample with respect to the incoming x-ray beam. The system designed successfully demonstrates the ability to resolve atomic-scale corrugations. In addition, experiments with synchrotron x-ray radiation validate the SXSTM system as an accurate analysis technique for the study of local magnetic and chemical properties on sample surfaces. The SXSTM system's capabilities have the potential to broaden and deepen the general understanding of surface phenomena by adding elemental contrast to the high-resolution of STM. -- Highlights: ► Synchrotron enhanced x-ray scanning tunneling microscope (SXSTM) system designed. ► Unique STM mount design allows angular DOF for tip alignment with x-ray beam. ► System demonstrates ability to resolve atomic corrugations on HOPG. ► Studies show chemical sensitivity with STM tip from photocurrent and tunneling. ► Results show system's ability to study local magnetic (XMCD) properties on Fe films.

  9. Green LED associated to 20% hydrogen peroxide for dental bleaching: nanomorfologic study of enamel by scanning electron microscopy

    Science.gov (United States)

    Oliveira, Susana C. P. S.; Santos, Gustavo M. P.; Monteiro, Juliana S. C.; Sampaio, Fernando J. P.; Gesteira, Maria F. M.; Zanin, Fátima A. A.; Santos, Marcos A. V.; Pinheiro, Antônio L. B.

    2013-03-01

    Dental bleaching is a much requested procedure in clinical dental practice and widely related to dental esthetics. The literature is contradictory regarding the effects of bleaching agents on the morphology and demineralization of enamel after bleaching. The aim of this study was to analyze in vitro by scanning electron microscopy (SEM) the effect of hydrogen peroxide at 20% at neutral pH, cured by the green LED, to evaluate the action of these substances on dental enamel. We selected 15 pre-molars, lingual surfaces were sectioned and previously marked with a central groove to take the experimental and control groups on the same specimen. The groups were divided as follows. The mesial hemi-faces were the experimental group and distal ones as controls. For morphological analysis were performed 75 electron micrographs SEM with an increase of X 43, X 220 and X 1000 and its images were evaluated by tree observers. Was also performed quantitative analysis of the determination of the surface atomic composition of the samples through microanalysis with the aid of scanning electron microscopy. The use of hydrogen peroxide at a concentration of 20% at photoactivated green LED showed no significant changes in mineral composition of the samples or the dental morphological structure of the same when compared to their controls, according to the study protocol.

  10. X-Band Rapid-Scan Electron Paramagnetic Resonance of Radiation-Induced Defects in Tooth Enamel

    OpenAIRE

    Yu, Zhelin; Romanyukha, Alexander; Eaton, Sandra S.; Eaton, Gareth R.

    2015-01-01

    X-band rapid-scan electron paramagnetic resonance (EPR) spectra from tooth enamel samples irradiated with doses of 0.5, 1 and 10 Gy had substantially improved signal-to-noise relative to conventional continuous wave EPR. The radiation-induced signal in 60 mg of a tooth enamel sample irradiated with a 0.5 Gy dose was readily characterized in spectra recorded with 34 min data acquisition times. The coefficient of variance of the calculated dose for a 1 Gy irradiated sample, based on simulation ...

  11. Channelling phenomenon in the gamma irradiated Benzo-quinone and other compounds observed under the scanning electron microscope

    International Nuclear Information System (INIS)

    Scanning Electron Microscope (S.E.M.), has been used to examine the gamma irradiated pure crystals of Benzo-quinone and other compounds in the polycrystaline form. After gamma irradiation, shallow lines (channels) were observed on the crystal's surfaces when the crystal layers arrangements are parallel to the photons beam direction. Holes were also observed when those layers of the crystals are in the nonparallel case. The phenomenon has been studied and analysed in connected with the H-atom bonds disruption, and H-atoms migration through the crystal's layers. (author)

  12. Analysis of archaeological materials through Scanning electron microscopy; Analisis de materiales arqueologicos a traves de la Microscopia electronica de barrido

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, A.; Tenorio C, D. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Elizalde, S.; Mandujano, C.; Cassiano, G. [Escuela Nacional de Antropologia e Historia, 14000 Mexico D.F. (Mexico)

    2005-07-01

    With the purpose to know the uses and the chemical composition of some cultural objects in the pre hispanic epoch this work presents several types of analysis for identifying them by means of the Scanning electron microscopy and its techniques as the Functional analysis of artifacts based on the 'tracks of use' analysis, also the X-ray spectroscopy and the X-ray dispersive energy (EDS) are mentioned, all of them allowing a major approach to the pre hispanic culture in Mexico. (Author)

  13. Direct imaging of light elements by annular dark-field aberration-corrected scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lotnyk, Andriy, E-mail: andriy.lotnyk@iom-leipzig.de; Poppitz, David; Gerlach, Jürgen W.; Rauschenbach, Bernd [Leibniz Institute of Surface Modification, Permoserstr. 15, D-04318 Leipzig (Germany)

    2014-02-17

    In this report, we show that an annular dark-field detector in an aberration-corrected scanning transmission electron microscope allows the direct observation of light element columns in crystalline lattices. At specific imaging conditions, an enhancement of the intensities of light element columns in the presence of heavy element columns is observed. Experimental results are presented for imaging the nitrogen and carbon atomic columns at the GaN-SiC interface and within the GaN and SiC compounds. The crystal polarity of GaN at the interface is identified. The obtained findings are discussed and are well supported by image simulations.

  14. Scanning and transmission electron microscopy of a craniopharyngioma: x-ray microanalytical study of the intratumoral mineralized deposits

    Energy Technology Data Exchange (ETDEWEB)

    Vilches, J.; Lopez, A.; Martinez, M.C.; Gomez, J.; Barbera, J.

    This paper discusses the value of scanning electron microscopy (SEM) and x-ray microanalysis in the classification of craniopharyngiomas. This neoplasm shows epithelial nest, cords of cuboid cells, foci of squamous metaplasia, and microcystic degeneration. SEM reveals that the epithelial cysts are lined with elongated cells that possess numerous microvilli and blebs and that some cysts are lined with polyhedral cells. The microvilli are interpreted as characteristic of the fast growing craniopharyngiomas. A microanalytical study of the calcified areas reveals the presence of magnesium, phosphorus, and calcium.

  15. Description of spermatheca and eggs of Eurygaster austriaca (Schrank, 1778) (Heteroptera: Scutelleridae),based on optical and scanning electron microscopy

    OpenAIRE

    CANDAN, Selami; Suludere, Zekiye; GÜLLÜ, Mustafa

    2011-01-01

    Spermatheca and egg morphology of Eurygaster austriaca (Schrank, 1778) were studied by optical and scanning electron microscopy (SEM). The spermatheca of E. austriaca is characterized by a spermathecal bulb, a pumping region, distal and proximal flanges and ducts, and a genital chamber. Each female was shown to deposit 14 green eggs on average in mass. The spherical eggs averaged 1.05 ± 0.05 mm in diameter. The first external evidence of embryonic development was the appearance of 2 red eye s...

  16. Characterization of gold nanoparticle films: Rutherford backscattering spectroscopy, scanning electron microscopy with image analysis, and atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Pia C. Lansåker

    2014-10-01

    Full Text Available Gold nanoparticle films are of interest in several branches of science and technology, and accurate sample characterization is needed but technically demanding. We prepared such films by DC magnetron sputtering and recorded their mass thickness by Rutherford backscattering spectroscopy. The geometric thickness dg—from the substrate to the tops of the nanoparticles—was obtained by scanning electron microscopy (SEM combined with image analysis as well as by atomic force microscopy (AFM. The various techniques yielded an internally consistent characterization of the films. In particular, very similar results for dg were obtained by SEM with image analysis and by AFM.

  17. Electron density dependence of the spin Hall effect in GaAs probed by scanning Kerr rotation microscopy

    Science.gov (United States)

    Matsuzaka, S.; Ohno, Y.; Ohno, H.

    2009-12-01

    We studied electron density (n) dependence of the extrinsic spin Hall effect in n -doped GaAs with n raging from 1.8×1016 to 3.3×1017cm-3 . By scanning Kerr microscopy measurements, we observed spin accumulation near the channel edges in all the samples due to the extrinsic spin Hall effect. The spin Hall conductivity σSH is obtained for each sample by comparing the Kerr rotation induced by optically injected spins. σSH is found to increase with n , and it is shown that a theoretical model reported earlier agrees well with the experimental n dependence of σSH .

  18. Scanning probe microscopy and field emission schemes for studying electron emission from polycrystalline diamond

    Science.gov (United States)

    Chubenko, Oksana; Baturin, Stanislav S.; Baryshev, Sergey V.

    2016-09-01

    The letter introduces a diagram that rationalizes tunneling atomic force microscopy (TUNA) observations of electron emission from polycrystalline diamonds as described in the recent publications [Chatterjee et al., Appl. Phys. Lett. 104, 171907 (2014); Harniman et al., Carbon 94, 386 (2015)]. The direct observations of electron emission from the grain boundary sites by TUNA could indeed be the evidence of electrons originating from grain boundaries under external electric fields. At the same time, from the diagram, it follows that TUNA and field emission schemes are complimentary rather than equivalent for results interpretation. It is further proposed that TUNA could provide better insights into emission mechanisms by measuring the detailed structure of the potential barrier on the surface of polycrystalline diamonds.

  19. In situ scanning tunnelling microscopy of redox molecules. Coherent electron transfer at large bias voltages

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Kuznetsov, A.M.; Ulstrup, Jens

    2003-01-01

    Theories of in situ scanning tunnelling microscopy (STM) of molecules with redox levels near the substrate and tip Fermi levels point to 'spectroscopic' current-overpotential features. Prominent features require a narrow 'probing tip', i.e. a small bias voltage, eV(bias), compared with the molecu......Theories of in situ scanning tunnelling microscopy (STM) of molecules with redox levels near the substrate and tip Fermi levels point to 'spectroscopic' current-overpotential features. Prominent features require a narrow 'probing tip', i.e. a small bias voltage, eV(bias), compared...... with the molecular and solvent reorganisation Gibbs energy, E-r. However, a large V-bias is frequently needed for stable imaging. This applies particularly to in situ STM of redox metalloproteins, emerging as a new approach to imaging of biological processes directly in aqueous medium. We provide first an extension...... of previous theoretical work on in situ STM of redox molecules, to large bias voltages, \\eV(bias)\\ > E-r. Large bias voltages give tunnelling contrasts independent of the overpotential over a broad range, as both the oxidised and reduced redox levels are located within the 'energy tip' between the substrate...

  20. Scanning drift tube measurements of electron transport parameters in different gases: argon, synthetic air, methane and deuterium

    Science.gov (United States)

    Korolov, I.; Vass, M.; Donkó, Z.

    2016-10-01

    Measurements of transport coefficients of electrons in a scanning drift tube apparatus are reported for different gases: argon, synthetic air, methane and deuterium. The experimental system allows the spatio-temporal development of the electron swarms (‘swarm maps’) to be recorded and this information, when compared with the profiles predicted by theory, makes it possible to determine the ‘time-of-flight’ transport coefficients: the bulk drift velocity, the longitudinal diffusion coefficient and the effective ionization coefficient, in a well-defined way. From these data, the effective Townsend ionization coefficient is determined as well. The swarm maps provide, additionally, direct, unambiguous information about the hydrodynamic/non-hydrodynamic regimes of the swarms, aiding the selection of the proper regions applicable for the determination of the transport coefficients.

  1. A study of internal oxidation in carburized steels by glow discharge optical emission spectroscopy and scanning electron microscopy

    CERN Document Server

    An, X; Rainforth, W M; Chen, L

    2003-01-01

    The internal oxidation of Cr-Mn carburizing steel was studied. Internal oxidation was induced using a commercial carburizing process. Sputter erosion coupled with glow discharge optical emission spectroscopy (GDOES) was used to determine the depth profile elemental distribution within the internal oxidation layer (<10 mu m). In addition, scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) studies were carried out on selected sputter eroded surfaces. Oxide type was identified primarily by transmission electron microscopy (TEM). The carburized surface was found to consist of a continuous oxide layer, followed by a complex internal oxidation layer, where Cr and Mn oxides were found to populate grain boundaries in a globular form in the near surface region. At greater depths (5-10 mu m), Si oxides formed as a grain boundary network. The internal oxides (mainly complex oxides) grew quickly during the initial stages of the carburizing process (2 h, 800 deg. C+3 h, 930 deg. C). G...

  2. Improved Fixation of Cellulose-Acetate Reverse-Osmosis Membrane for Scanning Electron Microscopy

    OpenAIRE

    Kutz, S. M.; Bentley, D L; Sinclair, N A

    1985-01-01

    Fixation of cellulose-acetate membranes with either glutaraldehyde-osmium tetroxide or glutaraldehyde-ruthenium tetroxide resulted in extensive electron beam damage. Beam damage was eliminated and the bacterial surface structure was preserved, however, when cellulose-acetate membranes were fixed with glutaraldehyderuthenium tetroxide and treated successively with thiocarbohydrazide and osmium tetroxide.

  3. Scanning electron microscopy of the oral apparatus and buccopharyngeal cavity of Atelognathus salai larvae (Anura, Neobatrachia

    Directory of Open Access Journals (Sweden)

    Dinorah D. Echeverría

    2006-09-01

    Full Text Available The aim of this study is to describe the horny structures of the buccal apparatus and buccopharyngeal cavity of A. salai by means ofscanning electron microscopy (SEM, and to compare them to those of the other known species of Atelognathus and related genera.

  4. The EMR-scan: assessing the quality of Electronic Medical Records in general practice.

    NARCIS (Netherlands)

    Verheij, R.; Jabaaij, L.; Njoo, K.; Hoogen, H. van den; Bakker, D. de

    2008-01-01

    Background: The use of electronic medical records (EMR) in general practice has spread rapidly in the last decade (more than 90% today). Traditionally, these records are primarily used for direct patient care and for administrative purposes by the practice involved. In recent years, further technica

  5. Electronic coupling in self-assembled nanocrystal arrays, a scanning tunneling microscopy study

    NARCIS (Netherlands)

    Overgaag, K.

    2008-01-01

    Colloidal semiconductor nanocrystals (NCs) are one the most actively studied components of modern nanoscience. The high degree of control over their size and shape makes it possible to accurately tune their opto-electronic properties through quantum confinement. Colloidal nanocrystals can serve as b

  6. EVALUATION OF THE ULTRASTRUCTURE OF THE SMALL INTESTINE OF HIV INFECTED CHILDREN BY TRANSMISSION AND SCANNING ELECTRONIC MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Christiane Araujo Chaves LEITE

    2013-03-01

    Full Text Available Objectives To describe HIV children's small intestinal ultrastructural findings. Methods Descriptive, observational study of small intestine biopsies performed between August 1994 and May 1995 at São Paulo, SP, Brazil. This material pertained to 11 HIV infected children and was stored in a laboratory in paraffin blocks. Scanning and transmission electronic microscopy were used to view those intestine samples and ultrastructural findings were described by analyzing digitalized photos of this material. Ethical Committee approval was obtained. Results In most samples scanning microscopy showed various degrees of shortening and decreasing number of microvilli and also completes effacements in some areas. Derangement of the enterocytes was seen frequently and sometimes cells well defined borders limits seemed to be loosened. In some areas a mucous-fibrin like membrane with variable thickness and extension appeared to partially or totally coat the epithelial surface. Fat drops were present in the intestinal lumen in various samples and a bacterium morphologically resembling bacilli was seen in two occasions. Scanning microscopy confirmed transmission microscopy microvilli findings and also showed little “tufts” of those structures. In addition, it showed an increased number of vacuoles and multivesicular bodies inside various enterocytes, an increased presence of intraepithelial lymphocytes, mitochondrial vacuolization and basement membrane enlargement in the majority of samples analyzed. However, some samples exhibited normal aspect. Conclusions Our study showed the common occurrence of various important intestinal ultrastructural alterations with variable degrees among HIV infected children, some of them in our knowledge not described before.

  7. Bioactivity of miltefosine against aquatic stages of Schistosoma mansoni, Schistosoma haematobium and their snail hosts, supported by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    El Bardicy Samia

    2011-05-01

    Full Text Available Abstract Background Miltefosine, which is the first oral drug licensed for the treatment of leishmaniasis, was recently reported to be a promising lead compound for the synthesis of novel antischistosomal derivatives with potent activity in vivo against different developmental stages of Schistosoma mansoni. In this paper an in vitro study was carried out to investigate whether it has a biocidal activity against the aquatic stages of Schistosoma mansoni and its snail intermediate host, Biomphalaria alexandrina , thus being also a molluscicide. Additionally, to see whether miltefosine can have a broad spectrum antischistosomal activity, a similar in vitro study was carried out on the adult stage of Schistosoma haematobium, the second major human species, its larval stages and snail intermediate host, Bulinus truncutes. This was checked by scanning electron microscopy. Results Miltefosine proved to have in vitro ovicidal, schistolarvicidal and lethal activity on adult worms of both Schistosoma species and has considerable molluscicidal activity on their snail hosts. Scanning electron microscopy revealed several morphological changes on the different stages of the parasite and on the soft body of the snail, which further strengthens the current evidence of miltefosine's activity. This is the first report of mollusicidal activity of miltefosine and its in vitro schistosomicidal activity against S.haematobium. Conclusions This study highlights miltefosine not only as a potential promising lead compound for the synthesis of novel broad spectrum schistosomicidal derivatives, but also for molluscicidals.

  8. IN VITRO ANALYSIS OF MARGINAL ADAPTATION AND RESISTANCE OF DIFFERENT DENTAL COMPOSITES: STEREO AND SCANNING ELECTRON MICROSCOPIC EVALUATION.

    Science.gov (United States)

    Pilolli, G P; Lauritano, D; Lucchese, A; Di Stasio, D; Petruzzi, M; Marrone, G; Serpico, R; Favia, G

    2015-01-01

    To compare the performance, by scanning electron microscopic analysis, of the interface between tooth and four commercial restorative composite resins in Class I cavities following exposure to acidified artificial solution, pH 4.5, with a background electrolyte composition similar to saliva, 600 teeth were divided into 4 groups. The first group was treated with microfilled light-cured Heliomolar; the second group with Durafill; the third group with the microfilled self-cured Isomolar; and the fourth group was treated using the hybrid self-cured Miradapt. All teeth of each group were randomly divided into two sub-groups: A) a control group that was immersed in artificial saliva (pH 7); B) a study group that was immersed in artificial saliva acidified with phosphoric acid (pH 4.5) in order to obtain artificial caries. The samples were examined by scanning electron microscopy. Data were analyzed using Pearson’s Chi-squared test (χ2) with R statistical software. The statistical analyses demonstrated significant differences in the two sub-groups A and B when considered for the light-cured composites whereas no difference was monitored for self-cured composites. Statistical analysis (p minore di 0.001) also demonstrated that the type of composite strongly influenced the infiltration grade. Our results demonstrate that incremental layering techniques might improve the marginal adaptation for light-cured composites, while self-cured show a marked polymerization contraction which can cause marginal breakdown.

  9. Analysis of self-organized In(Ga)As quantum structures with the scanning transmission electron microscope

    International Nuclear Information System (INIS)

    Aim of this thesis was to apply the analytical methods of the scanning transmission electron microscopy to the study of self-organized In(Ga)As quantum structures. With the imaging methods Z contrast and bright field (position resolutions in the subnanometer range) and especially with the possibilities of the quantitative chemical EELS analysis of the scanning transmission electron microscope (STEM) fundamental questions concerning morphology and chemical properties of self-organized quantum structures should be answered. By the high position resolution of the STEM among others essentail morphological and structural parameters in the growth behaviour of ''dot in a well'' (DWell) structures and of vertically correlated quantum dots (QDs) could be analyzed. For the optimization of DWell structures samples were studied, the nominal InAs-QD growth position was directedly varied within the embedding InGaAs quantum wells. The STEM offers in connection with the EELS method a large potential for the chemical analysis of quantum structures. Studied was a sample series of self-organized InGaAs/GaAs structures on GaAs substrate, the stress of which was changed by varying the Ga content of the INGaAs material between 2.4 % and 4.3 %

  10. [Scanning electron microscopy studies of the structure of tissue in the cochlear opening of the cochlear aqueduct].

    Science.gov (United States)

    Galić, M; Giebel, W

    1987-01-01

    The structure of the internal and external tissue of the cochlear opening of the cochlear aquaeduct was examined by light microscopy on semithin sections and by scanning electron microscopy. The whole area is filled with a net of mesenchymal cells. The cell axes are randomly orientated inside the aquaeduct. On the outside of the cochlear aquaeduct fibrocytic tissue fills a space which is triangular in cross-section between the basal part of the cochlea wall of the tympanic scala and the middle portion of the round window membrane. In this area the direction of the net is uniform and it gives the impression of anchorage of the round window membrane on the perilymphatic side. The rim bordering the perilymphatic space is a dense net but not fully closed. The scanning electron microscopic pictures taken perpendicular to this border structure show clearly a texture of mesenchymal cells with open spaces. No closed "membrana limitans" was found. The possible function of the fixation of the round window membrane to the perilymphatic space giving rise to an asymmetric perilymph movement is discussed with regard to the physiology of sound transmission. PMID:3561119

  11. Automated transmission-mode scanning electron microscopy (tSEM) for large volume analysis at nanoscale resolution.

    Science.gov (United States)

    Kuwajima, Masaaki; Mendenhall, John M; Lindsey, Laurence F; Harris, Kristen M

    2013-01-01

    Transmission-mode scanning electron microscopy (tSEM) on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm(2) (65.54 µm per side) at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM) system, which were only 66.59 µm(2) (8.160 µm per side) at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm(2) and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm). Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems. PMID:23555711

  12. Automated transmission-mode scanning electron microscopy (tSEM for large volume analysis at nanoscale resolution.

    Directory of Open Access Journals (Sweden)

    Masaaki Kuwajima

    Full Text Available Transmission-mode scanning electron microscopy (tSEM on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm(2 (65.54 µm per side at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM system, which were only 66.59 µm(2 (8.160 µm per side at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm(2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm. Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems.

  13. Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

    Energy Technology Data Exchange (ETDEWEB)

    Villarrubia, J.S., E-mail: john.villarrubia@nist.gov [Semiconductor and Dimensional Metrology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Vladár, A.E.; Ming, B. [Semiconductor and Dimensional Metrology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Kline, R.J.; Sunday, D.F. [Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Chawla, J.S.; List, S. [Intel Corporation, RA3-252, 5200 NE Elam Young Pkwy, Hillsboro, OR 97124 (United States)

    2015-07-15

    The width and shape of 10 nm to 12 nm wide lithographically patterned SiO{sub 2} lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines' widths and shapes are parameters. The approximately 32 nm pitch sample was patterned at Intel using a state-of-the-art pitch quartering process. Their narrow widths and asymmetrical shapes are representative of near-future generation transistor gates. These pose a challenge: the narrowness because electrons landing near one edge may scatter out of the other, so that the intensity profile at each edge becomes width-dependent, and the asymmetry because the shape requires more parameters to describe and measure. Modeling was performed by JMONSEL (Java Monte Carlo Simulation of Secondary Electrons), which produces a predicted yield vs. position for a given sample shape and composition. The simulator produces a library of predicted profiles for varying sample geometry. Shape parameter values are adjusted until interpolation of the library with those values best matches the measured image. Profiles thereby determined agreed with those determined by transmission electron microscopy and critical dimension small-angle x-ray scattering to better than 1 nm.

  14. Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

    International Nuclear Information System (INIS)

    The width and shape of 10 nm to 12 nm wide lithographically patterned SiO2 lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines' widths and shapes are parameters. The approximately 32 nm pitch sample was patterned at Intel using a state-of-the-art pitch quartering process. Their narrow widths and asymmetrical shapes are representative of near-future generation transistor gates. These pose a challenge: the narrowness because electrons landing near one edge may scatter out of the other, so that the intensity profile at each edge becomes width-dependent, and the asymmetry because the shape requires more parameters to describe and measure. Modeling was performed by JMONSEL (Java Monte Carlo Simulation of Secondary Electrons), which produces a predicted yield vs. position for a given sample shape and composition. The simulator produces a library of predicted profiles for varying sample geometry. Shape parameter values are adjusted until interpolation of the library with those values best matches the measured image. Profiles thereby determined agreed with those determined by transmission electron microscopy and critical dimension small-angle x-ray scattering to better than 1 nm

  15. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.

    Science.gov (United States)

    Ogura, Toshihiko

    2009-08-01

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  16. Scanning Probe Microscopy Study of Electronic Properties in Alkyl-substituted Oligothiopene-based Field-Effect Transitors

    Science.gov (United States)

    Afsharimani, N.; Nysten, B.

    It appeared in the past decades that semi-conducting organic liquid crystals could easily replace the inorganic semi-conductors to manufacture field-effect transistors (FET). They can be easily processed by simple methods such as inkjet printing. These simple and cheap manufacturing methods pave the way to new applications for plastic electronics: electronic tags, biosensors, flexible screens, … The performance of these liquid crystal nanomaterials is due to their specific nanoscale structure. However, one limitation to the improvement of organic electronic devices is an incomplete understanding of their optoelectronic properties at the nanoscale. The organic semiconductor films often contain a combination of many ordered and disordered regions, grain boundaries and localized traps. These features impact charge transport and trapping at the sub-100 nm length scales [1]. Electrical SPM techniques such as STM, KPFM, EFM and CS-AFM have the potential to provide the correlation between the electronic properties directly and local film structure and have already made important contributions to the field of organic electronics. Here we report on the investigation of the structural and electronic properties of p-conductive organic field-effect transistors based on alkyl-substituted oligothiophenes with bottom-contact structure. For this purpose we use atomic force microscopy (AFM) and Kelvin-probe force microscopy (KPFM) in dual frequency mode under ambient conditions. This study helps to determine the local potential in the channel of active OFETs. On the other hand the molecular arrangements of these molecules on the HOPG surface have been studied using scanning tunnelling microscopy (STM) at the liquid-solid interface.

  17. A cryogen-free low temperature scanning tunneling microscope capable of inelastic electron tunneling spectroscopy.

    Science.gov (United States)

    Zhang, Shuai; Huang, Di; Wu, Shiwei

    2016-06-01

    The design and performance of a cryogen-free low temperature scanning tunneling microscope (STM) housed in ultrahigh vacuum (UHV) are reported. The cryogen-free design was done by directly integrating a Gifford-McMahon cycle cryocooler to a Besocke-type STM, and the vibration isolation was achieved by using a two-stage rubber bellow between the cryocooler and a UHV-STM interface with helium exchange gas cooling. A base temperature of 15 K at the STM was achieved, with a possibility to further decrease by using a cryocooler with higher cooling power and adding additional low temperature stage under the exchange gas interface. Atomically sharp STM images and high resolution dI/dV spectra on various samples were demonstrated. Furthermore, we reported the inelastic tunneling spectroscopy on a single carbon monoxide molecule adsorbed on Ag(110) surface with a cryogen-free STM for the first time. Being totally cryogen-free, the system not only saves the running cost significantly but also enables uninterrupted data acquisitions and variable temperature measurements with much ease. In addition, the system is capable of coupling light to the STM junction by a pair of lens inside the UHV chamber. We expect that these enhanced capabilities could further broaden our views to the atomic-scale world. PMID:27370453

  18. A cryogen-free low temperature scanning tunneling microscope capable of inelastic electron tunneling spectroscopy.

    Science.gov (United States)

    Zhang, Shuai; Huang, Di; Wu, Shiwei

    2016-06-01

    The design and performance of a cryogen-free low temperature scanning tunneling microscope (STM) housed in ultrahigh vacuum (UHV) are reported. The cryogen-free design was done by directly integrating a Gifford-McMahon cycle cryocooler to a Besocke-type STM, and the vibration isolation was achieved by using a two-stage rubber bellow between the cryocooler and a UHV-STM interface with helium exchange gas cooling. A base temperature of 15 K at the STM was achieved, with a possibility to further decrease by using a cryocooler with higher cooling power and adding additional low temperature stage under the exchange gas interface. Atomically sharp STM images and high resolution dI/dV spectra on various samples were demonstrated. Furthermore, we reported the inelastic tunneling spectroscopy on a single carbon monoxide molecule adsorbed on Ag(110) surface with a cryogen-free STM for the first time. Being totally cryogen-free, the system not only saves the running cost significantly but also enables uninterrupted data acquisitions and variable temperature measurements with much ease. In addition, the system is capable of coupling light to the STM junction by a pair of lens inside the UHV chamber. We expect that these enhanced capabilities could further broaden our views to the atomic-scale world.

  19. A cryogen-free variable temperature scanning tunneling microscope capable for inelastic electron tunneling spectroscopy

    Science.gov (United States)

    Zhang, Shuai; Huang, Di; Wu, Shiwei

    While low temperature scanning tunneling microscope (STM) has become an indispensable research tool in surface science, its versatility is yet limited by the shortage or high cost of liquid helium. The makeshifts include the use of alternative cryogen (such as liquid nitrogen) at higher temperature or the development of helium liquefier system usually at departmental or campus wide. The ultimate solution would be the direct integration of a cryogen-free cryocooler based on GM or pulse tube closed cycle in the STM itself. However, the nasty mechanical vibration at low frequency intrinsic to cryocoolers has set the biggest obstacle because of the known challenges in vibration isolation required to high performance of STM. In this talk, we will present the design and performance of our home-built cryogen-free variable temperature STM at Fudan University. This system can obtain atomically sharp STM images and high resolution dI/dV spectra comparable to state-of-the-art low temperature STMs, but with no limitation on running hours. Moreover, we demonstrated the inelastic tunneling spectroscopy (STM-IETS) on a single CO molecule with a cryogen-free STM for the first time.

  20. Direct writing of electronic devices on graphene oxide by catalytic scanning probe lithography

    Science.gov (United States)

    Zhang, Kun; Fu, Qiang; Pan, Nan; Yu, Xinxin; Liu, Jinyang; Luo, Yi; Wang, Xiaoping; Yang, Jinlong; Hou, Jianguo

    2012-01-01

    Reduction of graphene oxide at the nanoscale is an attractive approach to graphene-based electronics. Here we use a platinum-coated atomic force microscope tip to locally catalyse the reduction of insulating graphene oxide in the presence of hydrogen. Nanoribbons with widths ranging from 20 to 80 nm and conductivities of >104 S m−1 are successfully generated, and a field effect transistor is produced. The method involves mild operating conditions, and uses arbitrary substrates, atmospheric pressure and low temperatures (≤115 °C). PMID:23149739

  1. Characterizing nanoscale scanning probes using electron microscopy: A novel fixture and a practical guide

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Tevis D. B., E-mail: tjacobs@pitt.edu [Department of Mechanical Engineering and Materials Science, University of Pittsburgh, 3700 O’Hara St., Pittsburgh, Pennsylvania 15208 (United States); Wabiszewski, Graham E.; Goodman, Alexander J.; Carpick, Robert W., E-mail: carpick@seas.upenn.edu [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 S. 33rd St., Philadelphia, Pennsylvania 19104 (United States)

    2016-01-15

    The nanoscale geometry of probe tips used for atomic force microscopy (AFM) measurements determines the lateral resolution, contributes to the strength of the tip-surface interaction, and can be a significant source of uncertainty in the quantitative analysis of results. While inverse imaging of the probe tip has been used successfully to determine probe tip geometry, direct observation of the tip profile using electron microscopy (EM) confers several advantages: it provides direct (rather than indirect) imaging, requires fewer algorithmic parameters, and does not require bringing the tip into contact with a sample. In the past, EM-based observation of the probe tip has been achieved using ad hoc mounting methods that are constrained by low throughput, the risk of contamination, and repeatability issues. We report on a probe fixture designed for use in a commercial transmission electron microscope that enables repeatable mounting of multiple AFM probes as well as a reference grid for beam alignment. This communication describes the design, fabrication, and advantages of this probe fixture, including full technical drawings for machining. Further, best practices are discussed for repeatable, non-destructive probe imaging. Finally, examples of the fixture’s use are described, including characterization of common commercial AFM probes in their out-of-the-box condition.

  2. Characterizing nanoscale scanning probes using electron microscopy: A novel fixture and a practical guide

    Science.gov (United States)

    Jacobs, Tevis D. B.; Wabiszewski, Graham E.; Goodman, Alexander J.; Carpick, Robert W.

    2016-01-01

    The nanoscale geometry of probe tips used for atomic force microscopy (AFM) measurements determines the lateral resolution, contributes to the strength of the tip-surface interaction, and can be a significant source of uncertainty in the quantitative analysis of results. While inverse imaging of the probe tip has been used successfully to determine probe tip geometry, direct observation of the tip profile using electron microscopy (EM) confers several advantages: it provides direct (rather than indirect) imaging, requires fewer algorithmic parameters, and does not require bringing the tip into contact with a sample. In the past, EM-based observation of the probe tip has been achieved using ad hoc mounting methods that are constrained by low throughput, the risk of contamination, and repeatability issues. We report on a probe fixture designed for use in a commercial transmission electron microscope that enables repeatable mounting of multiple AFM probes as well as a reference grid for beam alignment. This communication describes the design, fabrication, and advantages of this probe fixture, including full technical drawings for machining. Further, best practices are discussed for repeatable, non-destructive probe imaging. Finally, examples of the fixture's use are described, including characterization of common commercial AFM probes in their out-of-the-box condition.

  3. Characterizing nanoscale scanning probes using electron microscopy: A novel fixture and a practical guide

    International Nuclear Information System (INIS)

    The nanoscale geometry of probe tips used for atomic force microscopy (AFM) measurements determines the lateral resolution, contributes to the strength of the tip-surface interaction, and can be a significant source of uncertainty in the quantitative analysis of results. While inverse imaging of the probe tip has been used successfully to determine probe tip geometry, direct observation of the tip profile using electron microscopy (EM) confers several advantages: it provides direct (rather than indirect) imaging, requires fewer algorithmic parameters, and does not require bringing the tip into contact with a sample. In the past, EM-based observation of the probe tip has been achieved using ad hoc mounting methods that are constrained by low throughput, the risk of contamination, and repeatability issues. We report on a probe fixture designed for use in a commercial transmission electron microscope that enables repeatable mounting of multiple AFM probes as well as a reference grid for beam alignment. This communication describes the design, fabrication, and advantages of this probe fixture, including full technical drawings for machining. Further, best practices are discussed for repeatable, non-destructive probe imaging. Finally, examples of the fixture’s use are described, including characterization of common commercial AFM probes in their out-of-the-box condition

  4. Scanning electron microscopy of individual nanoparticle bio-markers in liquid.

    Science.gov (United States)

    Liv, Nalan; Lazić, Ivan; Kruit, Pieter; Hoogenboom, Jacob P

    2014-08-01

    We investigated SEM imaging of nanoparticle biomarkers suspended below a thin membrane, with the ultimate goal of integrating functional fluorescence and structural SEM measurements of samples kept at ambient or hydrated conditions. In particular, we investigated how resolving power in liquid SEM is affected by the interaction of the electron beam with the membrane. Simulations with the Geant4-based Monte Carlo scheme developed by Kieft and Bosch (2008) [1] are compared to experimental results with suspended nanoparticles. For 20 nm and 50 nm thin membranes, we found a beam broadening of 1.5 nm and 3 nm, respectively, with an excellent agreement between simulations and experiments. 15 nm Au nanoparticles and bio-functionalized core-shell quantum dots can be individually resolved in denser clusters. We demonstrated the imaging of single EGF-conjugated quantum dots docked at filopodia during cellular uptake with both fluorescence microscopy and SEM simultaneously. These results open novel opportunities for correlating live fluorescence microscopy with structural electron microscopy. PMID:24103705

  5. Scanning electron microscopic structure of the prismatic layer in the Bivalvia

    Institute of Scientific and Technical Information of China (English)

    Iwao KOBAYASHI

    2008-01-01

    The shell structure of the Bivalvia has been observed with the use of optical and electron microscopes since the early 1900's. The prismatic structure is one of the more attractive shell structures in bivalved mollusks. This structure is composed of the aggregation of polygonal prisms arranged densely. Each prism is made of small calcite crystallites arranged perpendicular to a growth shell surface. Organic materials, named organic sheaths, accumulate around prisms and stain well with heamatox-ylin-eosin.The Bivalvia, which make prismatic structures, are divided into two groups. One group has the inner shell layer made up of a nacreous structure, and the other has the inner shell layer made up of a foliated structure. The aragonite prismatic layer and the prismatic layer are clo-sely related to each other, as is the aragonite prismatic layer to the composite prismatic one.

  6. Super-resolution phase reconstruction technique in electron holography with a stage-scanning system

    Science.gov (United States)

    Lei, Dan; Mitsuishi, Kazutaka; Harada, Ken; Shimojo, Masayuki; Ju, Dongying; Takeguchi, Masaki

    2014-02-01

    Super-resolution image reconstruction is a digital signal processing technique that allows creating a high-resolution image from multiple low-resolution images taken at slightly different positions. We introduce the super-resolution image reconstruction technique into electron holography for reconstructing phase images as follows: the studied specimen is shifted step-wise with a high-precision piezo holder, and a series of holograms is recorded. When the step size is not a multiple of the CCD pixel size, processing of the acquired series results in a higher pixel density and spatial resolution as compared to the phase image obtained with conventional holography. The final resolution exceeds the limit of the CCD pixel size divided by the magnification.

  7. Mask CD uniformity improvement by electron scanning exposure based Global Loading Effect Correction

    Science.gov (United States)

    Li, Rivan; Tian, Eric; Shi, Irene; Guo, Eric; Lu, Max

    2015-07-01

    Critical Dimension (CD) Uniformity is one of the necessary parameters to assure good performance and reliable functionality of any integrated circuit (IC), and towards the advanced technology node 28nm and beyond, corresponding CD Uniformity becomes more and more crucial. It is found that bad mask CD Uniformity is a significant error source at 28nm process. The CD Uniformity on mask, if not controlled well, will badly impact wafer CD performance, and it has been well-studied that CD Uniformity issue from gate line-width in transistors would affect the device performance directly. In this paper we present a novel solution for mask global CD uniformity error correction, which is called as global loading effect correction (GLEC) method and applied nesting in the mask exposure map during the electron beam exposure. There are factors such as global chip layout, writing sequence and chip pattern density distribution (Global Loading), that work on the whole mask CD Uniformity, especially Global Loading is the key factor related to mask global CD error. From our experimental results, different pattern density distribution on mask significantly influenced the final mask CD Uniformity: the mask with undulating pattern density distribution provides much worse CD Uniformity than that with uniform one. Therefore, a GLEC model based on pattern density has been created to compensate the global error during the electron beam exposure, which has been proved to be efficacious to improve mask global CD Uniformity performance. Furthermore, it 's also revealed that pattern type is another important impact factor, and GLEC coefficient need be modified due to the specific pattern type (e.g. dense line-space only, iso-space only or an average of them) to improve the corresponding mask CD uniformity.

  8. Effects of image noise on contact edge roughness and critical dimension uniformity measurement in synthesized scanning electron microscope images

    Science.gov (United States)

    Constantoudis, Vassilios; Kuppuswamy, Vijaya-Kumar Murugesan; Gogolides, Evangelos

    2013-01-01

    We study the effects of noise in scanning electron microscope (SEM) images on the size and roughness of contact holes when they are measured using top-down SEM images. The applied methodology is based on the generation of synthesized top-down SEM images, including several model contact edges with controlled roughness, critical dimension (CD) uniformity, and noise. The sources of image noise can be the shot noise of SEM electron beams and microscope electronics. The results show that noise reduces CD and correlation length while it increases the rms value of contact edge roughness (CER). CD variation is increased with noise in images with smooth and identical contacts, whereas it remains almost unaltered in images including rough contacts with CD nonuniformity. Furthermore, we find that the application of a noise-smoothing filter before image analysis rectifies the values of CD (at small filter parameter) and of rms and correlation length (at larger filter parameters), whereas it leads to marginally larger deviations from the true values of CD variation. Quantitative assessment of the model predictions reveals that the noise-induced variations of CD and CER values are less important compared with those caused by process stochasticity and material inhomogeneities.

  9. Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting

    Energy Technology Data Exchange (ETDEWEB)

    De Backer, A.; Martinez, G.T. [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); MacArthur, K.E.; Jones, L. [Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH (United Kingdom); Béché, A. [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Nellist, P.D. [Department of Materials, University of Oxford, 16 Parks Road, Oxford OX1 3PH (United Kingdom); Van Aert, S., E-mail: sandra.vanaert@uantwerpen.be [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2015-04-15

    Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations. - Highlights: • Limited size and beam sensitivity of nano-particles challenge their quantification. • Keeping the electron dose to a minimum is therefore important. • Reliability of quantitative ADF STEM for atom-counting is demonstrated. • Limits for single atom sensitivity are discussed. • Limits are diagnosed by combining simulations and a statistical method.

  10. Experimental quantification of annular dark-field images in scanning transmission electron microscopy.

    Science.gov (United States)

    Lebeau, James M; Stemmer, Susanne

    2008-11-01

    This paper reports on a method to obtain atomic resolution Z-contrast (high-angle annular dark-field) images with intensities normalized to the incident beam. The procedure bypasses the built-in signal processing hardware of the microscope to obtain the large dynamic range necessary for consecutive measurements of the incident beam and the intensities in the Z-contrast image. The method is also used to characterize the response of the annular dark-field detector output, including conditions that avoid saturation and result in a linear relationship between the electron flux reaching the detector and its output. We also characterize the uniformity of the detector response across its entire area and determine its size and shape, which are needed as input for image simulations. We present normalized intensity images of a SrTiO(3) single crystal as a function of thickness. Averaged, normalized atom column intensities and the background intensity are extracted from these images. The results from the approach developed here can be used for direct, quantitative comparisons with image simulations without any need for scaling. PMID:18707809

  11. Applying semantic web technologies for phenome-wide scan using an electronic health record linked Biobank

    Directory of Open Access Journals (Sweden)

    Pathak Jyotishman

    2012-12-01

    Full Text Available Abstract Background The ability to conduct genome-wide association studies (GWAS has enabled new exploration of how genetic variations contribute to health and disease etiology. However, historically GWAS have been limited by inadequate sample size due to associated costs for genotyping and phenotyping of study subjects. This has prompted several academic medical centers to form “biobanks” where biospecimens linked to personal health information, typically in electronic health records (EHRs, are collected and stored on a large number of subjects. This provides tremendous opportunities to discover novel genotype-phenotype associations and foster hypotheses generation. Results In this work, we study how emerging Semantic Web technologies can be applied in conjunction with clinical and genotype data stored at the Mayo Clinic Biobank to mine the phenotype data for genetic associations. In particular, we demonstrate the role of using Resource Description Framework (RDF for representing EHR diagnoses and procedure data, and enable federated querying via standardized Web protocols to identify subjects genotyped for Type 2 Diabetes and Hypothyroidism to discover gene-disease associations. Our study highlights the potential of Web-scale data federation techniques to execute complex queries. Conclusions This study demonstrates how Semantic Web technologies can be applied in conjunction with clinical data stored in EHRs to accurately identify subjects with specific diseases and phenotypes, and identify genotype-phenotype associations.

  12. Performance of signal-to-noise ratio estimation for scanning electron microscope using autocorrelation Levinson-Durbin recursion model.

    Science.gov (United States)

    Sim, K S; Lim, M S; Yeap, Z X

    2016-07-01

    A new technique to quantify signal-to-noise ratio (SNR) value of the scanning electron microscope (SEM) images is proposed. This technique is known as autocorrelation Levinson-Durbin recursion (ACLDR) model. To test the performance of this technique, the SEM image is corrupted with noise. The autocorrelation function of the original image and the noisy image are formed. The signal spectrum based on the autocorrelation function of image is formed. ACLDR is then used as an SNR estimator to quantify the signal spectrum of noisy image. The SNR values of the original image and the quantified image are calculated. The ACLDR is then compared with the three existing techniques, which are nearest neighbourhood, first-order linear interpolation and nearest neighbourhood combined with first-order linear interpolation. It is shown that ACLDR model is able to achieve higher accuracy in SNR estimation. PMID:26871742

  13. PENGARUH PERBEDAAN DURASI APLIKASI KONDISIONER TERHADAP GAMBARAN PENETRASI SEMEN IONOMER KACA PADA DENTIN SULUNG (Evaluasi Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Suzanty Ariany

    2015-07-01

    Full Text Available The purpose of this study was to determine whether different durations of conditioner application influenced glass ionomer cement penetration in dentin primary teeth. The conditioner being used was 10% polyacrylic acid. Samples in this study were 40 non-carious primary mandibular incisors. Samples were divided into 4 groups (10 samples each: group A, withoud conditioner, group B, with 10 seconds of conditioner application, group C, with 20 seconds of conditioner application, and group D with 30 seconds of conditioner application. Penetration of glass ionomer cement was observed using scanning electron microscopy (SEM with 200x magnification. One-way ANOVA and Tukey HSD test showed significant difference between groups. Longer conditioner application resulted in longer glass ionomer penetration in dentin of primary teeth.

  14. A comparative analysis of bleached and sound enamel structure through scanning electron microscopy and atomic force microscopy

    International Nuclear Information System (INIS)

    To analyze the effects of bleaching agent on enamel structure and to characterize the morphological and chemical changes in enamel due to bleaching. Study Design: Experimental study. Place and Duration of Study: School of Chemical and Material Engineering (SCME), NUST Islamabad from Feb to May 2013. Materials and Methods: Ten recently extracted pre molars between the 12-22 years age group were randomly assigned into two groups. Group one was a non-bleached control group with sound enamel. Group two was bleached with Everbrite In office tooth whitening system after specimen preparation, surface morphology was observed under SEM (scanned electron microscope) and AFM (Atomic force microscope). Results: The detrimental effects of hydrogen per-oxide on enamel were evident in bleached specimens under SEM, and AFM analysis. Conclusion: There were significant surface alterations found in the bleached specimens as compared to control group. However salivary buffering potentials could overcome the demineralizing effect of bleaching gel. (author)

  15. Scanning electron microscopic study of the effects of pressure on the luminal surface of the rabbit aorta.

    Science.gov (United States)

    Swinehart, P A; Bentley, D L; Kardong, K V

    1976-01-01

    The effects of pressure on the luminal surface of the rabbit aorta were investigated using the scanning electron microscope. The method followed was perfusion under hydrostatic pressure of a section of thoracic aorta, in vitro. The characteristic ridged pattern seen in sections fixed at zero hydrostatic pressure was to a large extent eliminated when fixation occurred at pressures equivalent to those experienced by the aorta at systole or diastole. This study suggests that the spiral ridged pattern is dependent upon the fixation pressure and may not be present in a normally functioning artery. Any attempts to characterize or interpret the appearance of the luminal arterial wall must take into account the effects of pressure.

  16. Study of air-induced paper discolorations by infrared spectroscopy, X-ray fluorescence, and scanning electron microscopy.

    Science.gov (United States)

    Ferreira, Adriana; Figueira, Francisca; Pessanha, Sofia; Nielsen, Ingelise; Carvalho, Maria Luisa

    2010-02-01

    Air-induced paper discoloration is described as being different from other discoloration morphologies. It seems to be the result of prolonged exposure to air in a humid and polluted environment without appropriate protecting coverage. In this work, three folios from the same eighteenth century book, presenting three degrees of discoloration and opacity and subjected to different environmental conditions, were examined and compared. Samples were analyzed and compared by three different instrumental techniques, mid-infrared spectroscopy, X-ray fluorescence (XRF), and scanning electron microscopy (SEM). Chemical and physical changes were confirmed from the data collected by these techniques. The absence of the secondary amide band characteristic of proteins in the infrared spectra of the two discolored folios, accompanied by the appearance and increase of white mineral-like deposits visible in the SEM micrographs, support the idea that oxidation reactions occurred and that these two folios were subjected to more severe degradation hazard. PMID:20149275

  17. Comparison of SOFC Cathode Microstructure Quantified using X-ray Nanotomography and Focused Ion Beam - Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, George J. [Univ. of Connecticut, Storrs, CT (United States); Harris, William H. [Univ. of Connecticut, Storrs, CT (United States); Lombardo, Jeffrey J. [Univ. of Connecticut, Storrs, CT (United States); Izzo, Jr., John R. [Univ. of Connecticut, Storrs, CT (United States); Chiu, W. K. S. [Univ. of Connecticut, Storrs, CT (United States); Tanasini, Pietro [Ecole Ploytechnique Federale de Lausanne (Switzerland); Cantoni, Marco [Ecole Ploytechnique Federale de Lausanne (Switzerland); Van herle, Jan [Ecole Ploytechnique Federale de Lausanne (Switzerland); Comninellis, Christos [Ecole Ploytechnique Federale de Lausanne (Switzerland); Andrews, Joy C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Liu, Yijin [SLAC National Accelerator Lab., Menlo Park, CA (United States); Pianetta, Piero [SLAC National Accelerator Lab., Menlo Park, CA (United States); Chu, Yong [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2011-03-24

    X-ray nanotomography and focused ion beam scanning electron microscopy (FIB-SEM) have been applied to investigate the complex 3D microstructure of solid oxide fuel cell (SOFC) electrodes at spatial resolutions of 45 nm and below. The application of near edge differential absorption for x-ray nanotomography and energy selected backscatter detection for FIB–SEM enable elemental mapping within the microstructure. Using these methods, non-destructive 3D x-ray imaging and FIB–SEM serial sectioning have been applied to compare three-dimensional elemental mapping of the LSM, YSZ, and pore phases in the SOFC cathode microstructure. The microstructural characterization of an SOFC cathode is reported based on these measurements. The results presented demonstrate the viability of x-ray nanotomography as a quantitative characterization technique and provide key insights into the SOFC cathode microstructure.

  18. FTIR spectroscopy and scanning electron microscopic analysis of pretreated biosorbent to observe the effect on Cr (VI) remediation.

    Science.gov (United States)

    Kiran, Bala; Rani, Nisha; Kaushik, Anubha

    2016-11-01

    Various chemical and physical treatments have been applied to indigenously isolated cyanobacterial strain, Lyngbya putealis HH-15, to observe the effect on chromium removal capacity. Pretreatment with hydrochloric acid (99.1%) and nitric acid (98.5%) resulted in enhanced chromium removal as compared to untreated control biosorbent (98.1%). Pretreatment with acetic acid (97.9%), methanol (97.0%), calcium chloride (96.0%), hot water (95.2%), and sodium hydroxide (93.9%) did not improve the chromium removal capacity of biosorbent. Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) analysis identified changes in biomass functionality and availability after physical and chemical modification-the results of which were in agreement with metal removal studies. In conclusion, this acid-treated biosorbent represents a suitable candidate to replace conventional removal technologies for metal-bearing wastewaters. PMID:27185214

  19. A scanning electron microscopy study of Argulus vittatus (Rafinesque-Schmaltz, 1814) (Crustacea: Branchiura) from Algerian coast.

    Science.gov (United States)

    Ider, Djamila; Ramdane, Zouhir; Courcot, Lucie; Amara, Rachid; Trilles, Jean-Paul

    2014-06-01

    A study of the Algerian Branchiura, Argulus vittatus (Rafinesque-Schmaltz, 1814) was conducted using the scanning electron microscopy (SEM). New morphological features are reported for the first time (mouth con, first maxilla, second maxilla, structures and ornamentation of thoracic segments, structure of semen papillae, etc.). The morphology of small and large female specimens was compared. Two new hosts, Pagellus erythrinus L. and Sparus aurata L., are reported for this species. Until now, six host species were reported for A. vittatus, and stenoxenic specificity for Sparid fishes was observed for Algerian specimens. The biogeographical distribution of this species seems to be restricted to the eastern coast of Algeria. Additional information about the host specificity, ecology, and life cycle of this parasitic species were given. PMID:24728522

  20. Characterization of nanometer-scale porosity in reservoir carbonate rock by focused ion beam-scanning electron microscopy.

    Science.gov (United States)

    Bera, Bijoyendra; Gunda, Naga Siva Kumar; Mitra, Sushanta K; Vick, Douglas

    2012-02-01

    Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam-scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50-300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2-5 μm) that were observed to further link with bulk pores outside the matrix.

  1. Further description of Aspidodera raillieti (Nematoda: Aspidoderidae) from Didelphis marsupialis (Mammalia: Didelphidae) by light and scanning electron microscopy.

    Science.gov (United States)

    Chagas-Moutinho, V A; Oliveira-Menezes, A; Cárdenas, M Q; Lanfredi, R M

    2007-10-01

    Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Freitas 1956 are widely distributed from Americas. The species of the genus Aspidodera Railliet and Henry 1912 are parasites of mammals of the orders Edentata, Marsupialia, and Rodentia. In the present work, Aspidodera raillieti (L. Travassos, Mem Inst Oswaldo Cruz 5(3):271-318, 1913), collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Valle del Cauca, Colombia, is redescribed. The association of light and scanning electron microscopy (SEM) allowed a detailed analysis of the morphology and ultrastructure of this nematode. Some taxonomic features, such as cephalic region, topography of the cuticle, sucker, spicules, posterior end of males, localization of vulva, the anus, and posterior end of females were observed. Important structures such as amphid, details of cephalic region, phasmid, and number and localization of caudal papillae are documented by SEM, for the first time adding characters to identify this species. Colombia is a new geographical record for A. raillieti.

  2. Further description of Aspidodera raillieti (Nematoda: Aspidoderidae) from Didelphis marsupialis (Mammalia: Didelphidae) by light and scanning electron microscopy.

    Science.gov (United States)

    Chagas-Moutinho, V A; Oliveira-Menezes, A; Cárdenas, M Q; Lanfredi, R M

    2007-10-01

    Nematodes of the family Aspidoderidae (Nematoda: Heterakoidea) Freitas 1956 are widely distributed from Americas. The species of the genus Aspidodera Railliet and Henry 1912 are parasites of mammals of the orders Edentata, Marsupialia, and Rodentia. In the present work, Aspidodera raillieti (L. Travassos, Mem Inst Oswaldo Cruz 5(3):271-318, 1913), collected from the large intestine of Didelphis marsupialis (Mammalia: Didelphidae) from Valle del Cauca, Colombia, is redescribed. The association of light and scanning electron microscopy (SEM) allowed a detailed analysis of the morphology and ultrastructure of this nematode. Some taxonomic features, such as cephalic region, topography of the cuticle, sucker, spicules, posterior end of males, localization of vulva, the anus, and posterior end of females were observed. Important structures such as amphid, details of cephalic region, phasmid, and number and localization of caudal papillae are documented by SEM, for the first time adding characters to identify this species. Colombia is a new geographical record for A. raillieti. PMID:17622560

  3. Photogrammetry of the three-dimensional shape and texture of a nanoscale particle using scanning electron microscopy and free software.

    Science.gov (United States)

    Gontard, Lionel C; Schierholz, Roland; Yu, Shicheng; Cintas, Jesús; Dunin-Borkowski, Rafal E

    2016-10-01

    We apply photogrammetry in a scanning electron microscope (SEM) to study the three-dimensional shape and surface texture of a nanoscale LiTi2(PO4)3 particle. We highlight the fact that the technique can be applied non-invasively in any SEM using free software (freeware) and does not require special sample preparation. Three-dimensional information is obtained in the form of a surface mesh, with the texture of the sample stored as a separate two-dimensional image (referred to as a UV Map). The mesh can be used to measure parameters such as surface area, volume, moment of inertia and center of mass, while the UV map can be used to study the surface texture using conventional image processing techniques. We also illustrate the use of 3D printing to visualize the reconstructed model.

  4. Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

    2010-07-01

    The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

  5. Characterization of heterogeneous SiO{sub 2} materials by scanning electron microscope and micro fluorescence XAS techniques

    Energy Technology Data Exchange (ETDEWEB)

    Khouchaf, L. [Centre de Recherche de l' Ecole des Mines deDouai, 941, rue Charles Bourseul, BP. 10838, 59508 Douai (France)]. E-mail: khouchaf@ensm-douai.fr; Boinski, F. [Centre de Recherche de l' Ecole des Mines deDouai, 941, rue Charles Bourseul, BP. 10838, 59508 Douai (France); Tuilier, M.H. [GMP Equipe de recherche: MMPF, Universite de Haute-Alsace, 61 rue Albert Camus, F-68093, Mulhouse Cedex (France); Flank, A.M. [SOLEIL and Swiss Light Source SLS CH-5232 Villigen PSI (Switzerland)

    2006-11-15

    Micro X-ray absorption near edge structure XANES and micro fluorescence experiments have been carried out using X-ray microbeam from synchrotron radiation source with high brightness to investigate the local structural evolutions of heterogeneous and natural SiO{sub 2} submitted to alkali-silica reaction ASR process. Compared to elemental maps obtained by Environmental Scanning Electron Microscope ESEM, micro fluorescence X maps showed the diffusion of potassium cations inside the grains with higher accuracy. Si K-edge spectra show the disorder induced by the dissolution of the grain from the outside to the inside. Potassium K-edge spectra do not show significant changes around K cations. The breaking of Si-O-Si bonds and the disorder of the (SiO{sub 4}) {sub n} network may be affected to potassium cations.

  6. Project NANO: Will allowing high school students to use research grade scanning electron microscopes increase their interest in science?

    Science.gov (United States)

    Smith, Leslie TenEyck

    In this study, one AP Biology curriculum unit and one general Biology curriculum unit that included tabletop Scanning Electron Microscope (SEM) technology provided by Project NANO, a grant-funded, collaborative initiative designed to integrate cutting-edge nanotechnology into high school classrooms were implemented at a public high school in rural Oregon. Nine students participated in the AP unit and 52 students participated in the general Biology unit. Each student completed an opinion-based pre and post survey to determine if using the SEM as a part of the curriculum unit had an impact on his or her interest in science or in nanoscience. Interviews were conducted to add to the data. The results indicate that using the SEM can increase a student's interest in science. Recommendations for improving student experience were identified.

  7. Atomically resolved FeSe/SrTiO3(001) interface structure by scanning transmission electron microscopy

    Science.gov (United States)

    Li, Fangsen; Zhang, Qinghua; Tang, Chenjia; Liu, Chong; Shi, Jinan; Nie, CaiNa; Zhou, Guanyu; Li, Zheng; Zhang, Wenhao; Song, Can-Li; He, Ke; Ji, Shuaihua; Zhang, Shengbai; Gu, Lin; Wang, Lili; Ma, Xu-Cun; Xue, Qi-Kun

    2016-06-01

    Interface-enhanced high-temperature superconductivity in one unit-cell FeSe films on SrTiO3(001) (STO) substrate has recently attracted much attention in condensed matter physics and material science. By combined in situ scanning tunneling microscopy/spectroscopy and ex situ scanning transmission electron microscopy studies, we report on atomically resolved structure including both lattice constants and actual atomic positions of the FeSe/STO interface under both non-superconducting and superconducting states. We observed TiO2 double layers and significant atomic displacements in the top two layers of STO, lattice compression of the Se-Fe-Se triple layer, and relative shift between bottom Se and topmost Ti atoms. By imaging the interface structures under various superconducting states, we unveil a close correlation between interface structure and superconductivity. Our atomic-scale identification of FeSe/STO interface structure provides insight on investigating the pairing mechanism of this interface-enhanced high-temperature superconducting system.

  8. A novel method of estimating dose responses for polymer gels using texture analysis of scanning electron microscopy images.

    Directory of Open Access Journals (Sweden)

    Cheng-Ting Shih

    Full Text Available Polymer gels are regarded as a potential dosimeter for independent validation of absorbed doses in clinical radiotherapy. Several imaging modalities have been used to convert radiation-induced polymerization to absorbed doses from a macro-scale viewpoint. This study developed a novel dose conversion mechanism by texture analysis of scanning electron microscopy (SEM images. The modified N-isopropyl-acrylamide (NIPAM gels were prepared under normoxic conditions, and were administered radiation doses from 5 to 20 Gy. After freeze drying, the gel samples were sliced for SEM scanning with 50×, 500×, and 3500× magnifications. Four texture indices were calculated based on the gray level co-occurrence matrix (GLCM. The results showed that entropy and homogeneity were more suitable than contrast and energy as dose indices for higher linearity and sensitivity of the dose response curves. After parameter optimization, an R (2 value of 0.993 can be achieved for homogeneity using 500× magnified SEM images with 27 pixel offsets and no outlier exclusion. For dose verification, the percentage errors between the prescribed dose and the measured dose for 5, 10, 15, and 20 Gy were -7.60%, 5.80%, 2.53%, and -0.95%, respectively. We conclude that texture analysis can be applied to the SEM images of gel dosimeters to accurately convert micro-scale structural features to absorbed doses. The proposed method may extend the feasibility of applying gel dosimeters in the fields of diagnostic radiology and radiation protection.

  9. Determination of bulk diffusion lengths for angle-lapped semiconductor material via the scanning electron microscope: A theoretical analysis

    Science.gov (United States)

    Vonroos, O.

    1978-01-01

    A standard procedure for the determination of the minority carrier diffusion length by means of a scanning electron microscope (SEM) consists in scanning across an angle-lapped surface of a P-N junction and measuring the resultant short circuit current I sub sc as a function of beam position. A detailed analysis of the I sub sc originating from this configuration is presented. It is found that, for a point source excitation, the I sub sc depends very simply on x, the variable distance between the surface and the junction edge. The expression for the I sub sc of a planar junction device is well known. If d, the constant distance between the plane of the surface of the semiconductor and the junction edge in the expression for the I of a planar junction is merely replaced by x, the variable distance of the corresponding angle-lapped junction, an expression results which is correct to within a small fraction of a percent as long as the angle between the surfaces, 2 theta sub 1, is smaller than 10 deg.

  10. Automated Classification Of Scanning Electron Microscope Particle Images Using Morphological Analysis

    Science.gov (United States)

    Lamarche, B. L.; Lewis, R. R.; Girvin, D. C.; McKinley, J. P.

    2008-12-01

    We are developing a software tool that can automatically classify anthropogenic and natural aerosol particulates using morphological analysis. Our method was developed using SEM (background and secondary electron) images of single particles. Particle silhouettes are detected and converted into polygons using Intel's OpenCV image processing library. Our analysis then proceeds independently for the two kinds of images. Analysis of secondary images concerns itself solely with the silhouette and seeks to quantify its shape and roughness. Traversing the polygon with spline interpolation, we uniformly sample k(s), the signed curvature of the silhouette's path as a function of distance along the perimeter s. k(s) is invariant under rotation and translation. The power spectrum of k(s) qualitatively shows both shape and roughness: more power at low frequencies indicates variation in shape; more power at higher frequencies indicates a rougher silhouette. We present a series of filters (low-, band-, and high-pass) which we convolve with k(s) to yield a set of parameters that characterize the shape and roughness numerically. Analysis of backscatter images focuses on the (visual) texture, which is the result of both composition and geometry. Using the silhouette as a boundary, we compute the variogram, a statistical measure of inter-pixel covariance as a function of distance. Variograms take on characteristic curves, which we fit with a heuristic, asymptotic function that uses a small set of parameters. The combination of silhouette and variogram fit parameters forms the basis of a multidimensional classification space whose dimensionality we may reduce by principal component analysis and whose region boundaries allow us to classify new particles. This analysis is performed without a priori knowledge of other physical, chemical, or climatic properties. The method will be adapted to multi-particulate images.

  11. Immobilization, hybridization, and oxidation of synthetic DNA on gold surface: Electron transfer investigated by electrochemistry and scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, Gerald D.; Chen Fan [Biological Engineering Program, Department of Biological and Irrigation Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322-4105 (United States); Zhou Anhong, E-mail: Anhong.Zhou@usu.edu [Biological Engineering Program, Department of Biological and Irrigation Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322-4105 (United States)

    2009-06-08

    Fundamental understanding of interfacial electron transfer (ET) among electrolyte/DNA/solid-surface will facilitate the design for electrical detection of DNA molecules. In this report, the electron transfer characteristics of synthetic DNA (sequence from pathogenic Cryptosporidium parvum) self-assembled on a gold surface was electrochemically studied. The effects of immobilization order on the interface ET related parameters such as diffusion coefficient (D{sub 0}), surface coverage ({theta}{sub R}), and monolayer thickness (d{sub i}) were determined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). DNA surface density ({Gamma}{sub DNA}) was determined by the integration of the charge of the electro-oxidation current peaks during the initial cyclic voltammetry scans. It was found that the DNA surface densities at different modifications followed the order: {Gamma}{sub DNA} (dsS-DNA/Au) > {Gamma}{sub DNA} (MCH/dsS-DNA/Au) > {Gamma}{sub DNA} (dsS-DNA/MCH/Au). It was also revealed that the electro-oxidation of the DNA modified gold surface would involve the oxidation of nucleotides (guanine and adenine) with a 5.51 electron transfer mechanism and the oxidative desorption of DNA and MCH molecules by a 3 electron transfer mechanism. STM topography and current image analysis indicated that the surface conductivity after each surface modification followed the order: dsS-DNA/Au < MCH/dsS-DNA/Au < oxidized MCH/dsS-DNA/Au < Hoechst/oxidized MCH/dsS-DNA/Au. The results from this study suggested a combination of variations in immobilization order may provide an alternative approach for the optimization of DNA hybridization and the further development for electrical detection of DNA.

  12. Electronic phase diagram of NaFe1-xCoxAs investigated by scanning tunneling microscopy

    Institute of Scientific and Technical Information of China (English)

    Zhou Xiao-Dong; Cai Peng; Wang Ya-Yu

    2013-01-01

    Our recent scanning tunneling microscopy (STM) studies of the NaFe1-xCoxAs phase diagram over a wide range of dopings and temperatures are reviewed.Similar to the high-Tc cuprates,the iron-based superconductors lie in close proximity to a magnetically ordered phase.Therefore,it is widely believed that magnetic interactions or fluctuations play an important role in triggering their Cooper pairings.Among the key issues regarding the electronic phase diagram are the properties of the parent spin density wave (SDW) phase and the superconducting (SC) phase,as well as the interplay between them.The NaFe1-xCoxAs is an ideal system for resolving these issues due to its rich electronic phases and the charge-neutral cleaved surface.In our recent work,we directly observed the SDW gap in the parent state,and it exhibits unconventional features that are incompatible with the simple Fermi surface nesting picture.The optimally doped sample has a single SC gap,but in the underdoped regime we directly viewed the microscopic coexistence of the SDW and SC orders,which compete with each other.In the overdoped regime we observed a novel pseudogap-like feature that coexists with superconductivity in the ground state,persists well into the normal state,and shows great spatial variations.The rich electronic structures across the phase diagram of NaFel-xCoxAs revealed here shed important new light for defining microscopic models of the iron-based superconductors.In particular,we argue that both the itinerant electrons and local moments should be considered on an equal footing in a realistic model.

  13. 3D Plant Cell Architecture of Arabidopsis thaliana (Brassicaceae Using Focused Ion Beam–Scanning Electron Microscopy

    Directory of Open Access Journals (Sweden)

    Bhawana

    2014-06-01

    Full Text Available Premise of the study: Focused ion beam–scanning electron microscopy (FIB-SEM combines the ability to sequentially mill the sample surface and obtain SEM images that can be used to create 3D renderings with micron-level resolution. We have applied FIB-SEM to study Arabidopsis cell architecture. The goal was to determine the efficacy of this technique in plant tissue and cellular studies and to demonstrate its usefulness in studying cell and organelle architecture and distribution. Methods: Seed aleurone, leaf mesophyll, stem cortex, root cortex, and petal lamina from Arabidopsis were fixed and embedded for electron microscopy using protocols developed for animal tissues and modified for use with plant cells. Each sample was sectioned using the FIB and imaged with SEM. These serial images were assembled to produce 3D renderings of each cell type. Results: Organelles such as nuclei and chloroplasts were easily identifiable, and other structures such as endoplasmic reticula, lipid bodies, and starch grains were distinguishable in each tissue. Discussion: The application of FIB-SEM produced 3D renderings of five plant cell types and offered unique views of their shapes and internal content. These results demonstrate the usefulness of FIB-SEM for organelle distribution and cell architecture studies.

  14. A novel two-axis load sensor designed for in situ scratch testing inside scanning electron microscopes.

    Science.gov (United States)

    Huang, Hu; Zhao, Hongwei; Wu, Boda; Wan, Shunguang; Shi, Chengli

    2013-01-01

    Because of a lack of available miniaturized multiaxial load sensors to measure the normal load and the lateral load simultaneously, quantitative in situ scratch devices inside scanning electron microscopes and the transmission electron microscopes have barely been developed up to now. A novel two-axis load sensor was designed in this paper. With an I-shaped structure, the sensor has the function of measuring the lateral load and the normal load simultaneously, and at the same time it has compact dimensions. Finite element simulations were carried out to evaluate stiffness and modal characteristics. A decoupling algorithm was proposed to resolve the cross-coupling between the two-axis loads. Natural frequency of the sensor was tested. Linearity and decoupling parameters were obtained from the calibration experiments, which indicate that the sensor has good linearity and the cross-coupling between the two axes is not strong. Via the decoupling algorithm and the corresponding decoupling parameters, simultaneous measurement of the lateral load and the normal load can be realized via the developed two-axis load sensor. Preliminary applications of the load sensor for scratch testing indicate that the load sensor can work well during the scratch testing. Taking advantage of the compact structure, it has the potential ability for applications in quantitative in situ scratch testing inside SEMs. PMID:23429516

  15. A Novel Two-Axis Load Sensor Designed for in Situ Scratch Testing inside Scanning Electron Microscopes

    Directory of Open Access Journals (Sweden)

    Chengli Shi

    2013-02-01

    Full Text Available Because of a lack of available miniaturized multiaxial load sensors to measure the normal load and the lateral load simultaneously, quantitative in situ scratch devices inside scanning electron microscopes and the transmission electron microscopes have barely been developed up to now. A novel two-axis load sensor was designed in this paper. With an I-shaped structure, the sensor has the function of measuring the lateral load and the normal load simultaneously, and at the same time it has compact dimensions. Finite element simulations were carried out to evaluate stiffness and modal characteristics. A decoupling algorithm was proposed to resolve the cross-coupling between the two-axis loads. Natural frequency of the sensor was tested. Linearity and decoupling parameters were obtained from the calibration experiments, which indicate that the sensor has good linearity and the cross-coupling between the two axes is not strong. Via the decoupling algorithm and the corresponding decoupling parameters, simultaneous measurement of the lateral load and the normal load can be realized via the developed two-axis load sensor. Preliminary applications of the load sensor for scratch testing indicate that the load sensor can work well during the scratch testing. Taking advantage of the compact structure, it has the potential ability for applications in quantitative in situ scratch testing inside SEMs.

  16. A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

    Science.gov (United States)

    Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.

    2016-01-01

    The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.

  17. Hormonal regulation of capillary fenestrae in the rat adrenal cortex: quantitative studies using objective lens staging scanning electron microscopy.

    Science.gov (United States)

    Apkarian, R P; Curtis, J C

    1986-01-01

    High magnification studies of the fenestrated capillary endothelium in the zona fasciculata (ZF) of rat adrenal glands were performed using the objective lens stage of an analytical scanning electron microscope (SEM) equipped with a lanthanum hexaboride emitter (LaB6). Resolution of surface substructure of the luminal membrane obtained with specimens decorated with gold/palladium (Au/Pd) was compared with that observed in others sputter coated with tantalum (Ta). High magnification (50,000x) of the fenestrated endothelium demonstrates that tantalum coating of the cryofractured adrenals improves the substructural detail compared to that seen in Au/Pd decorated specimens. The procedures used in specimen preparation, metal deposition and secondary electron imaging (SEI) are described. Quality imaging achieved using the objective lens stage is a result of the elimination of the SE-III component derived from backscattered electrons. Rat adrenals exhibited uniformly patent capillaries. High magnification micrographs of capillary walls were randomly recorded in two morphometric studies of the fenestral content of capillaries in the rat adrenal cortex. Adrenocorticotropic hormone (ACTH), when administered to rats following dexamethasone (DEX) treatment, significantly reduced the fenestrae/micron 2 of endothelial surface and increased the mean size of fenestrae. After hypophysectomy, the number of fenestrae/micron 2 declined over 48 h; within 2 h after ACTH was given to rats hypophysectomized 48 hours earlier, the fenestrae/micron 2 had increased two-fold. These studies indicate that ACTH plays an important role in modulating fenestral content of the capillary endothelium in the adrenal cortex. PMID:3027881

  18. 电子自旋共振扫描隧道显微镜%Electron spin resonance scanning tunneling microscope

    Institute of Scientific and Technical Information of China (English)

    郭阳; 李健梅; 陆兴华

    2015-01-01

    单电子自旋极有可能发展成为未来信息学的基础。以电子自旋为核心的新型单分子或单原子器件将最终成为基本信息单元,基于单电子的自旋态将有可能构筑未来量子计算机的量子比特。但是,如何实现对单个电子自旋及其相干态和纠缠态的测量和控制,目前仍然是一个很大的挑战。作为调控单个电子自旋的重要实验手段,电子自旋共振扫描隧道显微镜的发展一直备受关注。文章简要介绍了电子自旋共振扫描隧道显微镜的基本概念,阐述了其发展历史和最新进展,归纳了机理探索的研究成果,论述了该设备研发面临的挑战与对策,并对未来的发展和应用做了展望。%It is highly expected that the future informatics will be based on the spins of in-dividual electrons. The development of elementary information unit will eventually leads to novel single-molecule or single-atom devices based on electron spins;the quantum computer in the fu-ture can be constructed with single electron spins as the basic quantum bits. However, it is still a great challenge in detection and manipulation of a single electron spin, as well as its coherence and entanglement. As an ideal experimental tool for such tasks, the development of electron spin resonance scanning tunneling microscope (ESR-STM) has attracted great attention for decades. This paper briefly introduces the basic concept of ESR-STM. The development history of this in-strument and recent progresses are reviewed. The underlying mechanism is explored and summa-rized. The challenges and possible solutions are discussed. Finally, the prospect of future direction and applications are presented.

  19. 电子自旋共振扫描隧道显微镜%Electron spin resonance scanning tunneling microscope

    Institute of Scientific and Technical Information of China (English)

    郭阳; 李健梅; 陆兴华

    2015-01-01

    It is highly expected that the future informatics will be based on the spins of in-dividual electrons. The development of elementary information unit will eventually leads to novel single-molecule or single-atom devices based on electron spins;the quantum computer in the fu-ture can be constructed with single electron spins as the basic quantum bits. However, it is still a great challenge in detection and manipulation of a single electron spin, as well as its coherence and entanglement. As an ideal experimental tool for such tasks, the development of electron spin resonance scanning tunneling microscope (ESR-STM) has attracted great attention for decades. This paper briefly introduces the basic concept of ESR-STM. The development history of this in-strument and recent progresses are reviewed. The underlying mechanism is explored and summa-rized. The challenges and possible solutions are discussed. Finally, the prospect of future direction and applications are presented.%单电子自旋极有可能发展成为未来信息学的基础。以电子自旋为核心的新型单分子或单原子器件将最终成为基本信息单元,基于单电子的自旋态将有可能构筑未来量子计算机的量子比特。但是,如何实现对单个电子自旋及其相干态和纠缠态的测量和控制,目前仍然是一个很大的挑战。作为调控单个电子自旋的重要实验手段,电子自旋共振扫描隧道显微镜的发展一直备受关注。文章简要介绍了电子自旋共振扫描隧道显微镜的基本概念,阐述了其发展历史和最新进展,归纳了机理探索的研究成果,论述了该设备研发面临的挑战与对策,并对未来的发展和应用做了展望。

  20. 3D reconstruction of VZV infected cell nuclei and PML nuclear cages by serial section array scanning electron microscopy and electron tomography.

    Directory of Open Access Journals (Sweden)

    Mike Reichelt

    Full Text Available Varicella-zoster virus (VZV is a human alphaherpesvirus that causes varicella (chickenpox and herpes zoster (shingles. Like all herpesviruses, the VZV DNA genome is replicated in the nucleus and packaged into nucleocapsids that must egress across the nuclear membrane for incorporation into virus particles in the cytoplasm. Our recent work showed that VZV nucleocapsids are sequestered in nuclear cages formed from promyelocytic leukemia protein (PML in vitro and in human dorsal root ganglia and skin xenografts in vivo. We sought a method to determine the three-dimensional (3D distribution of nucleocapsids in the nuclei of herpesvirus-infected cells as well as the 3D shape, volume and ultrastructure of these unique PML subnuclear domains. Here we report the development of a novel 3D imaging and reconstruction strategy that we term Serial Section Array-Scanning Electron Microscopy (SSA-SEM and its application to the analysis of VZV-infected cells and these nuclear PML cages. We show that SSA-SEM permits large volume imaging and 3D reconstruction at a resolution sufficient to localize, count and distinguish different types of VZV nucleocapsids and to visualize complete PML cages. This method allowed a quantitative determination of how many nucleocapsids can be sequestered within individual PML cages (sequestration capacity, what proportion of nucleocapsids are entrapped in single nuclei (sequestration efficiency and revealed the ultrastructural detail of the PML cages. More than 98% of all nucleocapsids in reconstructed nuclear volumes were contained in PML cages and single PML cages sequestered up to 2,780 nucleocapsids, which were shown by electron tomography to be embedded and cross-linked by an filamentous electron-dense meshwork within these unique subnuclear domains. This SSA-SEM analysis extends our recent characterization of PML cages and provides a proof of concept for this new strategy to investigate events during virion assembly at the