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Sample records for scanning light microscopy

  1. Further observations on cerebellar climbing fibers. A study by means of light microscopy, confocal laser scanning microscopy and scanning and transmission electron microscopy.

    Science.gov (United States)

    Castejón, O J; Castejón, H V; Alvarado, M V

    2000-12-01

    The intracortical pathways of climbing fibers were traced in several vertebrate cerebella using light microscopy, confocal laser scanning microscopy, scanning and transmission electron microscopy. They were identified as fine fibers up to 1(micron thick, with a characteristic crossing-over bifurcation pattern. Climbing fiber collaterals were tridimensionally visualized forming thin climbing fiber glomeruli in the granular layer. Confocal laser scanning microscopy revealed three types of collateral processes at the interface between granular and Purkinje cell layers. Scanning electron microscopy showed climbing fiber retrograde collaterals in the molecular layer. Asymmetric synaptic contacts of climbing fibers with Purkinje dendritic spines and stellate neuron dendrites were characterized by transmission electron microscopy. Correlative microscopy allowed us to obtain the basic three-dimensional morphological features of climbing fibers in several vertebrates and to show with more accuracy a higher degree of lateral collateralization of these fibers within the cerebellar cortex. The correlative microscopy approach provides new views in the cerebellar cortex information processing.

  2. 3D correlative light and electron microscopy of cultured cells using serial blockface scanning electron microscopy

    Science.gov (United States)

    Lerner, Thomas R.; Burden, Jemima J.; Nkwe, David O.; Pelchen-Matthews, Annegret; Domart, Marie-Charlotte; Durgan, Joanne; Weston, Anne; Jones, Martin L.; Peddie, Christopher J.; Carzaniga, Raffaella; Florey, Oliver; Marsh, Mark; Gutierrez, Maximiliano G.

    2017-01-01

    ABSTRACT The processes of life take place in multiple dimensions, but imaging these processes in even three dimensions is challenging. Here, we describe a workflow for 3D correlative light and electron microscopy (CLEM) of cell monolayers using fluorescence microscopy to identify and follow biological events, combined with serial blockface scanning electron microscopy to analyse the underlying ultrastructure. The workflow encompasses all steps from cell culture to sample processing, imaging strategy, and 3D image processing and analysis. We demonstrate successful application of the workflow to three studies, each aiming to better understand complex and dynamic biological processes, including bacterial and viral infections of cultured cells and formation of entotic cell-in-cell structures commonly observed in tumours. Our workflow revealed new insight into the replicative niche of Mycobacterium tuberculosis in primary human lymphatic endothelial cells, HIV-1 in human monocyte-derived macrophages, and the composition of the entotic vacuole. The broad application of this 3D CLEM technique will make it a useful addition to the correlative imaging toolbox for biomedical research. PMID:27445312

  3. Customized patterned substrates for highly versatile correlative light-scanning electron microscopy

    Science.gov (United States)

    Benedetti, Lorena; Sogne, Elisa; Rodighiero, Simona; Marchesi, Davide; Milani, Paolo; Francolini, Maura

    2014-01-01

    Correlative light electron microscopy (CLEM) combines the advantages of light and electron microscopy, thus making it possible to follow dynamic events in living cells at nanometre resolution. Various CLEM approaches and devices have been developed, each of which has its own advantages and technical challenges. We here describe our customized patterned glass substrates, which improve the feasibility of correlative fluorescence/confocal and scanning electron microscopy. PMID:25391455

  4. Morphology of the dentin structure of sloths Bradypus tridactylus: a light and scanning electron microscopy investigation.

    Science.gov (United States)

    Santana, L N S; Barbosa, L V M; Teixeira, F B; Costa, A M P; Fernandes, L M P; Lima, R R

    2013-12-01

    The aim of this study was to describe the dentine morphology of sloths (Bradypus tridactylus). The sloth teeth were removed and prepared for light microscopy (LM) and scanning electron microscopy analyses (SEM). LM revealed two patterns of tubular dentins: an outer with dentinary tubules over the all tooth length and one in the inner part with larger diameter and more spaced tubules, when compared to those present in the outer dentine. These findings were confirmed by SEM, which revealed a tubular pattern in the outer dentine like in humans. The inner dentine displayed pared grouped tubules that were characterized as vascular channels. It can be concluded that this sloth species present two types of dentins: an inner dentin (ortodentin) and an outer dentin characterized as a vascular dentin. This suggests a partial evolutive/adaptive process of this dental tissue, as compared to other mammalian species. © 2013 Blackwell Verlag GmbH.

  5. Noise analysis of a white-light supercontinuum light source for multiple wavelength confocal laser scanning fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, Gail [Centre for Biophotonics, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow, G4 0NR (United Kingdom)

    2005-08-07

    Intensity correlations of a Ti : sapphire, Kr/Ar and a white-light supercontinuum were performed to quantify the typical signal amplitude fluctuations and hence ascertain the comparative output stability of the white-light supercontinuum source for confocal laser scanning microscopy (CLSM). Intensity correlations across a two-pixel sample (n = 1000) of up to 98%, 95% and 94% were measured for the Ti : sapphire, Kr/Ar and white-light supercontinuum source, respectively. The white-light supercontinuum noise level is therefore acceptable for CLSM, with the added advantage of wider wavelength flexibility over traditional CLSM excitation sources. The relatively low-noise white-light supercontinuum was then used to perform multiple wavelength sequential CLSM of guinea pig detrusor to confirm the reliability of the system and to demonstrate system flexibility.

  6. Diagonally Scanned Light-Sheet Microscopy for Fast Volumetric Imaging of Adherent Cells.

    Science.gov (United States)

    Dean, Kevin M; Roudot, Philippe; Reis, Carlos R; Welf, Erik S; Mettlen, Marcel; Fiolka, Reto

    2016-03-29

    In subcellular light-sheet fluorescence microscopy (LSFM) of adherent cells, glass substrates are advantageously rotated relative to the excitation and emission light paths to avoid glass-induced optical aberrations. Because cells are spread across the sample volume, three-dimensional imaging requires a light-sheet with a long propagation length, or rapid sample scanning. However, the former degrades axial resolution and/or optical sectioning, while the latter mechanically perturbs sensitive biological specimens on pliant biomimetic substrates (e.g., collagen and basement membrane). Here, we use aberration-free remote focusing to diagonally sweep a narrow light-sheet along the sample surface, enabling multicolor imaging with high spatiotemporal resolution. Further, we implement a dithered Gaussian lattice to minimize sample-induced illumination heterogeneities, significantly improving signal uniformity. Compared with mechanical sample scanning, we drastically reduce sample oscillations, allowing us to achieve volumetric imaging at speeds of up to 3.5 Hz for thousands of Z-stacks. We demonstrate the optical performance with live-cell imaging of microtubule and actin cytoskeletal dynamics, phosphoinositide signaling, clathrin-mediated endocytosis, polarized blebbing, and endocytic vesicle sorting. We achieve three-dimensional particle tracking of clathrin-associated structures with velocities up to 4.5 μm/s in a dense intracellular environment, and show that such dynamics cannot be recovered reliably at lower volumetric image acquisition rates using experimental data, numerical simulations, and theoretical modeling. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Visualising impregnated chitosan in Pinus radiata early wood cells using light and scanning electron microscopy.

    Science.gov (United States)

    Singh, Adya P; Singh, Tripti; Rickard, Catherine L

    2010-04-01

    Chitosan, a deacetylated product of an abundant naturally occurring biopolymer chitin, has been used in a range of applications, particularly in food and health areas, as an antimicrobial agent. In the work reported here Pinus radiata wood was impregnated with chitosan as an environmentally compatible organic biocide (Eikenes et al., 2005a,b) to protect wood against wood deteriorating microorganisms and to thus prolong the service life of wooden products. We developed sample preparation techniques targeted to visualise impregnated chitosan within wood tissues using light microscope and field-emission scanning electron microscope (FE-SEM). Sections were viewed with the light microscope without staining with a dye as well as after staining with the dye toluidine blue. Light microscopy was also undertaken on sections that had been stained with 1% aqueous osmium tetroxide (OsO(4)). For SEM observations, the sections were treated with OsO(4) and then examined with the FE-SEM, first in the secondary electron imaging mode (SEI) and then in the backscattered electron imaging (BEI) mode, imaging the same areas of a section in both SEI and BEI modes. The preparation techniques employed and the combined use of light and scanning electron microscopy provided valuable complementary information, revealing that chitosan had penetrated into the cavities (cell lumens, intercellular spaces) of all sizes present within wood tissues and had also impregnated early wood cell walls. The information obtained is discussed in relation to its importance in further development of chitosan formulations and refinement of impregnation technologies to optimise chitosan impregnation into and distribution within wood tissues as well as in assessing chitosan efficacy. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. 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...

  9. Poor electronic screening in lightly doped Mott insulators observed with scanning tunneling microscopy

    Science.gov (United States)

    Battisti, I.; Fedoseev, V.; Bastiaans, K. M.; de la Torre, A.; Perry, R. S.; Baumberger, F.; Allan, M. P.

    2017-06-01

    The effective Mott gap measured by scanning tunneling microscopy (STM) in the lightly doped Mott insulator (Sr1-xLax) 2IrO4 differs greatly from values reported by photoemission and optical experiments. Here we show that this is a consequence of the poor electronic screening of the tip-induced electric field in this material. Such effects are well known from STM experiments on semiconductors and go under the name of tip-induced band bending (TIBB). We show that this phenomenon also exists in the lightly doped Mott insulator (Sr1-xLax) 2IrO4 and that, at doping concentrations of x ≤4 % , it causes the measured energy gap in the sample density of states to be bigger than the one measured with other techniques. We develop a model able to retrieve the intrinsic energy gap leading to a value which is in rough agreement with other experiments, bridging the apparent contradiction. At doping x ≈5 % we further observe circular features in the conductance layers that point to the emergence of a significant density of free carriers in this doping range and to the presence of a small concentration of donor atoms. We illustrate the importance of considering the presence of TIBB when doing STM experiments on correlated-electron systems and discuss the similarities and differences between STM measurements on semiconductors and lightly doped Mott insulators.

  10. Optimal experimental design for the detection of light atoms from high-resolution scanning transmission electron microscopy images

    NARCIS (Netherlands)

    Gonnissen, J.; De Backer, A.; Den Dekker, A.J.; Martinez, G.T.; Rosenauer, A.; Sijbers, J.; Van Aert, S.

    2014-01-01

    We report an innovative method to explore the optimal experimental settings to detect light atoms from scanning transmission electron microscopy (STEM) images. Since light elements play a key role in many technologically important materials, such as lithium-battery devices or hydrogen storage

  11. Microscopical characterization of known postmortem root bands using light and scanning electron microscopy.

    Science.gov (United States)

    Hietpas, Jack; Buscaglia, JoAnn; Richard, Adam H; Shaw, Stephen; Castillo, Hilda S; Donfack, Joseph

    2016-10-01

    A postmortem root band (PMRB) is a distinct microscopic feature that is postulated to occur in hair remaining in the follicle during the postmortem interval [1] (Petraco et al., 1998). The scientific validity of this premise has been highlighted in two recent high-profile criminal cases involving PMRBs [2,3] (State of Florida v. Casey Marie Anthony, 2008; People v. Kogut, 2005). To better understand the fundamental aspects of postmortem root banding, the microscopical properties of known PMRBs(1) were characterized by light microscopy, and scanning electron microscope (SEM) imaging of microtomed sections of hairs showing root banding. The results from this study show that the appearance of the PMRB may be due to the degradation of the chemically labile, non-keratin intermacrofibrillar matrix (IMM) in the pre-keratin/keratogenous region of anagen hairs. In addition, this degradation is confined to the cortex of the hair, with no apparent damage to the layers of the cuticle. These results could provide valuable information for determining the mechanism of band formation, as well as identify a set of microscopic features that could be used to distinguish hairs with known PMRBs from similarly looking environmentally degraded hairs. Published by Elsevier Ireland Ltd.

  12. 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. © 2014 Blackwell Verlag GmbH.

  13. Precrystallization structures in supersaturated lysozyme solutions studied by dynamic light scattering and scanning force microscopy

    Science.gov (United States)

    Schaper, Achim; Georgalis, Yannis; Umbach, Patrick; Raptis, Jannis; Saenger, Wolfram

    1997-05-01

    A comparitive study of the nanostructure evolving during aggregation of hen-egg white lysozyme in supersaturated solution was carried out by dynamic light scattering (DLS) and scanning force microscopy (SFM). Lysozyme aggregate (cluster) formation was observed in solution in the presence of NaCl, (NH4)2SO4, and NaNO3 as precipitating agents. The growth kinetics were examined by DLS and revealed fractal growth of the clusters with a fractal dimension of 1.8 obtained independently of the type of inert salt. Such behavior is typical for diffusion-limited cluster-cluster (DLCA) aggregation. Initial lysozyme cluster sizes were in the range of 12-35 nm. SFM images of individual lysozyme clusters at the liquid-solid interface were obtained in the presence of NaCl and NaNO3 under crystallization conditions, and revealed cluster sizes in agreement with those determined by DLS. Extended domains of smaller sized clusters appeared on the mica surface after subjecting supersaturated lysozyme solutions to a dialysis step. The feasibility of DLS and SFM for monitoring the nano- and mesoscopic morphology of lysozyme aggregates in supersatured solutions and at the solid-liquid interface is discussed.

  14. The tip-sample water bridge and light emission from scanning tunnelling microscopy

    OpenAIRE

    Boyle, Michael G; Mitra, J; Dawson, Paul

    2009-01-01

    Light emission spectrum from a scanning tunnelling microscope (LESTM) is investigated as a function of relative humidity and shown to be a novel and sensitive means for probing the growth and properties of a water meniscus in the nm-scale. An empirical model of the light emission process is formulated and applied successfully to replicate the decay in light intensity and spectral changes observed with increasing relative humidity. The modelling indicates a progressive water filling of the tip...

  15. Lossless Three-Dimensional Parallelization in Digitally Scanned Light-Sheet Fluorescence Microscopy.

    Science.gov (United States)

    Dean, Kevin M; Fiolka, Reto

    2017-08-24

    We introduce a concept that enables parallelized three-dimensional imaging throughout large volumes with isotropic 300-350 nm resolution. By staggering high aspect ratio illumination beams laterally and axially within the depth of focus of a digitally scanned light-sheet fluorescence microscope (LSFM), multiple image planes can be simultaneously imaged with minimal cross-talk and light loss. We present a first demonstration of this concept for parallelized imaging by synthesizing two light-sheets with nonlinear Bessel beams and perform volumetric imaging of fluorescent beads and invasive breast cancer cells. This work demonstrates that in principle any digitally scanned LSFM can be parallelized in a lossless manner, enabling drastically faster volumetric image acquisition rates for a given sample brightness and detector technology.

  16. Scanning ultrafast electron microscopy.

    Science.gov (United States)

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

    2010-08-24

    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 which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.

  17. Nanocrystals of [Cu3(btc)2] (HKUST-1): a combined time-resolved light scattering and scanning electron microscopy study.

    Science.gov (United States)

    Zacher, Denise; Liu, Jianing; Huber, Klaus; Fischer, Roland A

    2009-03-07

    The formation of [Cu(3)(btc)(2)] (HKUST-1; btc = 1,3,5-benzenetricarboxylate) nanocrystals from a super-saturated mother solution at room temperature was monitored by time-resolved light scattering (TLS); the system is characterized by a rapid growth up to a size limit of 200 nm within a few minutes, and the size and shape of the crystallites were also determined by scanning electron microscopy (SEM).

  18. Micromorphology of epicuticular waxes and epistomatal chambers of pine species by electron microscopy and white light scanning interferometry.

    Science.gov (United States)

    Kim, Ki Woo; Lee, In Jung; Kim, Chang Soo; Lee, Don Koo; Park, Eun Woo

    2011-02-01

    High-resolution imaging and quantitative surface analysis of epicuticular waxes and epistomatal chambers of pine species were performed by field emission scanning electron microscopy and white light scanning interferometry. Both juvenile and adult needles were collected from the two-year-old seedlings of Pinus rigida and Pinus densiflora and subjected to surface observations. Epicuticular wax structures developed on the cuticle layer as well as in the epistomatal chambers and appeared to occlude the cavities in the two pine species. The stomata of P. densiflora were characterized by more distinctly raised rings around openings than P. rigida. The most common epicuticular wax structures of the two pine species included tubules with terminal openings and coiled rodlets. Wax platelets were deposited on epistomatal chambers. Either rodlets or tubules seemed to be longer and thicker in P. rigida than those in P. densiflora. White light scanning interferometry revealed quantitative surface profiles, demonstrating more ridged (ca. 4 μm high) stomatal apertures and nearly twofold deeper (ca. 20 μm deep) epistomatal chambers of P. densiflora than those of P. rigida. These results suggest that white light scanning interferometry can be applied to unravel the quantitative surface features of epicuticular sculptures on plant leaves.

  19. Embryogenesis and Larval Development of the Asteroid Patiriella regularis Viewed by Light and Scanning Electron Microscopy.

    Science.gov (United States)

    Byrne, M; Barker, M F

    1991-06-01

    The sea star Patiriella regularis (Verrill, 1867) has indirect development through bipinnaria and brachiolaria larvae. Development of this species is typical of asteroids with planktotrophic larvae and takes 9-10 weeks. The embryos develop through a wrinkled blastula and hatch as early gastrulae. In contrast to most asteroids, a third enterocoel forms on the left side of the stomach of the bipinnaria. This structure gives rise to the left posterior coelom; its significance is discussed. We suggest that this coelom is homologous to the trunk coelom in enteropneust embryology. The surface features of the larvae were examined by scanning electron microscopy. Newly hatched gastrulae are covered by cilia, and the bipinnaria have bands of cilia that follow the contours of the larval processes. A previously undescribed plug-like structure positioned on the post-oral surface appears to function as a seal for the mouth. Brachiolaria larvae have three brachiolar arms and a centrally located adhesive disc. Each arm is covered by adhesive papillae. Raised epithelial cells that dot the surface of the papillae and adhesive disc may be batteries of secretory cells. The brachiolar arms have an extracellular coat that may serve as a protective cover for the adhesive surfaces. Competent brachiolaria swim along the substratum and exhibit searching behavior with flexure of the median brachium. They settle on the undersides of natural shell substrata and do not respond to a primary algal film. Shade appears to be an important factor in settlement and metamorphosis in P. regularis. Metamorphosis takes 5-6 days, and the post-larvae take up a free existence at a diameter of 450-500 {mu}m. The indirect development of P. regularis contrasts with the lecithotrophic and viviparous modes of development of other Patiriella species and provides the comparative basis to determine the ontogenic changes involved with evolution of direct development in the genus. The use of the divergent life

  20. Light propagation studies on laser modified waveguides using scanning near-field optical microscopy

    DEFF Research Database (Denmark)

    Borrise, X.; Berini, Abadal Gabriel; Jimenez, D.

    2001-01-01

    microscope (SNOM) has been used. The laser modifications locally changes the optical properties of the waveguide. The change in the effective refractive index is attributed to a TE to TM mode conversion, Thus, the laser modification might be a new way to fabricate optical mode converters.......By means of direct laser writing on Al, a new method to locally modify optical waveguides is proposed. This technique has been applied to silicon nitride waveguides, allowing modifications of the optical propagation along the guide. To study the formed structures, a scanning near-held optical...

  1. Confocal scanning microscopy

    DEFF Research Database (Denmark)

    Bariani, Paolo

    This report is based on a metrological investigation on confocal microscopy technique carried out by Uffe Rolf Arlø Theilade and Paolo Bariani. The purpose of the experimental activity was twofold a metrological instrument characterization and application to assessment of rough PP injection moulded...... replicated topography. Confocal microscopy is seen to be a promising technique in metrology of microstructures. Some limitations with respect to surface metrology were found during the experiments. The experiments were carried out using a Zeiss LSM 5 Pascal microscope owned by the Danish Polymer Centre...

  2. Deleterious phases precipitation on superduplex stainless steel UNS S32750: characterization by light optical and scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Juan Manuel Pardal

    2010-09-01

    Full Text Available Deleterious phases precipitation in superduplex stainless steels is the main concern in fabrication by welding and hot forming of this class of material. Sigma, chi and secondary austenite phases are considered deleterious phases because they produce negative effects on corrosion resistance. Besides, sigma and chi phases also promote strong decrease of toughness. In the present work, the precipitations of sigma, chi and secondary austenite under aging in the 800-950 °C interval were studied in two UNS S32750 steels with different grain sizes. The deleterious phases could be quantified by light optical microscopy, with no distinction between them. Scanning electron microscopy was used to distinguish the individual phases in various aging conditions. The results elucidate the influence of the aging temperature and grain size on the kinetics precipitation and morphology of deleterious phases. The kinetics of deleterious phases is higher in the fine grained material in the initial stage of aging, but the maximum amount of deleterious phases is higher in the coarse grained steel.

  3. Comparison of tissue damage caused by various laser systems with tissue tolerable plasma by light and laser scan microscopy

    Science.gov (United States)

    Vandersee, Staffan; Lademann, Jürgen; Richter, Heike; Patzelt, Alexa; Lange-Asschenfeldt, Bernhard

    2013-10-01

    Tissue tolerable plasma (TTP) represents a novel therapeutic method with promising capabilities in the field of dermatological interventions, in particular disinfection but also wound antisepsis and regeneration. The energy transfer by plasma into living tissue is not easily educible, as a variety of features such as the medium’s actual molecule-stream, the ions, electrons and free radicals involved, as well as the emission of ultraviolet, visible and infrared light contribute to its increasingly well characterized effects. Thus, relating possible adversary effects, especially of prolonged exposure to a single component of the plasma’s mode of action, is difficult. Until now, severe adverse events connected to plasma exposure have not been reported when conducted according to existing therapeutic protocols. In this study, we have compared the tissue damage-potential of CO2 and dye lasers with TTP in a porcine model. After exposure of pig ear skin to the three treatment modalities, all specimens were examined histologically and by means of laser scan microscopy (LSM). Light microscopical tissue damage could only be shown in the case of the CO2 laser, whereas dye laser and plasma treatment resulted in no detectable impairment of the specimens. In the case of TTP, LSM examination revealed only an impairment of the uppermost corneal layers of the skin, thus stressing its safety when used in vivo.

  4. Use of light, scanning electron microscopy and bioassays to evaluate parasitism by entomopathogenic fungi of the red scale insect of palms (Phoenicococcus marlatti Ckll., 1899).

    Science.gov (United States)

    Asensio, L; Lopez-Llorca, L V; López-Jiménez, J A

    2005-01-01

    We have evaluated the parasitism of the red scale insect of the date palm (Phoenicococcus marlatti) by entomopathogenic fungi, using light microscopy (LM), scanning electron microscopy (SEM) and low temperature scanning electron microscopy (LTSEM). Beauveria bassiana, Lecanicillium dimorphum and Lecanicillium cf. psalliotae, were inoculated directly on the scale insects or on insect infested plant material. We found that L. dimorphum and L. cf. psalliotae developed on plant material and on scale insects, making infection structures. B. bassiana was a bad colonizer of date palm leaves (Phoenix dactylifera L.) and did not parasite the scale insects.

  5. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  6. Scanning quantum decoherence microscopy.

    Science.gov (United States)

    Cole, Jared H; Hollenberg, Lloyd C L

    2009-12-09

    The use of qubits as sensitive nanoscale magnetometers has been studied theoretically and recently demonstrated experimentally. In this paper we propose a new concept, in which a scanning two-state quantum system is used to probe a sample through the subtle effects of decoherence. Mapping both the Hamiltonian and decoherence properties of a qubit simultaneously provides a unique image of the magnetic (or electric) field properties at the nanoscale. The resulting images are sensitive to the temporal as well as spatial variation in the fields created by the sample. As examples we theoretically study two applications; one from condensed matter physics, the other biophysics. The individual components required to realize the simplest version of this device (characterization and measurement of qubits, nanoscale positioning) have already been demonstrated experimentally.

  7. High-resolution characterization of the diffusion of light chemical elements in metallic components by scanning microwave microscopy.

    Science.gov (United States)

    Optasanu, Virgil; Bourillot, Eric; Vitry, Pauline; Plassard, Cédric; Beaurenaut, Laure; Jacquinot, Pierre; Herbst, Frédéric; Berger, Pascal; Lesniewska, Eric; Montessin, Tony

    2014-12-21

    An original sub-surface, high spatial resolution tomographic technique based on scanning microwave microscopy (SMM) is used to visualize in-depth materials with different chemical compositions. A significant phase difference in SMM between aluminum and chromium buried patterns has been observed. Moreover this technique was used to characterize a solid solution of a light chemical element (oxygen) in a metal lattice (zirconium). The large solubility of the oxygen in zirconium leads to modifications of the properties of the solid solution that can be measured by the phase shift signal in the SMM technique. The signal obtained in cross-section of an oxidized Zr sample shows the excellent agreement between phase shift profiles measured at different depths. Such a profile can reveal the length of diffusion of the oxygen in zirconium under the surface. The comparison with the oxygen concentration measured by nuclear reaction analysis shows excellent agreement in terms of length of diffusion and spatial distribution of the oxygen. A rapid calibration shows a linear dependence between the phase shift and the oxygen concentration. The SMM method opens up new possibilities for indirect measurements of the oxygen concentration dissolved in the metal lattice.

  8. Vacuum scanning capillary photoemission microscopy

    DEFF Research Database (Denmark)

    Aseyev, S.A.; Cherkun, A P; Mironov, B N

    2017-01-01

    We demonstrate the use of a conical capillary in a scanning probe microscopy for surface analysis. The probe can measure photoemission from a substrate by transmitting photoelectrons along the capillary as a function of probe position. The technique is demonstrated on a model substrate consisting...

  9. High Resolution Scanning Ion Microscopy

    NARCIS (Netherlands)

    Castaldo, V.

    2011-01-01

    The structure of the thesis is the following. The first chapter is an introduction to scanning microscopy, where the path that led to the Focused Ion Beam (FIB) is described and the main differences between electrons and ion beams are highlighted. Chapter 2 is what is normally referred to (which I

  10. Direct characterization of ultraviolet-light-induced refractive index structures by scanning near-field optical microscopy

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Madsen, S.; Hvam, Jørn Märcher

    1998-01-01

    We have applied a reflection scanning near-field optical microscope to directly probe ultraviolet (UV)-light-induced refractive index structures in planar glass samples. This technique permits direct comparison between topography and refractive index changes (10(-5)-10(-3)) with submicrometer...... lateral resolution, The proposed method yields detailed information about the topography and index profiles of UV-written waveguides....

  11. Coherent light microscopy

    CERN Document Server

    Ferraro, Pietro; Zalevsky, Zeev

    2011-01-01

    This book deals with the latest achievements in the field of optical coherent microscopy. While many other books exist on microscopy and imaging, this book provides a unique resource dedicated solely to this subject. Similarly, many books describe applications of holography, interferometry and speckle to metrology but do not focus on their use for microscopy. The coherent light microscopy reference provided here does not focus on the experimental mechanics of such techniques but instead is meant to provide a users manual to illustrate the strengths and capabilities of developing techniques. Th

  12. Light Sheet Fluorescence Microscopy

    Science.gov (United States)

    Santi, Peter A.

    2011-01-01

    Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with subcellular resolution. This method is well suited for imaging deep within transparent tissues or within whole organisms, and because tissues are exposed to only a thin plane of light, specimen photobleaching and phototoxicity are minimized compared to wide-field fluorescence, confocal, or multiphoton microscopy. LSFMs produce well-registered serial sections that are suitable for three-dimensional reconstruction of tissue structures. Because of a lack of a commercial LSFM microscope, numerous versions of light sheet microscopes have been constructed by different investigators. This review describes development of the technology, reviews existing devices, provides details of one LSFM device, and shows examples of images and three-dimensional reconstructions of tissues that were produced by LSFM. PMID:21339178

  13. Laser scanning laser diode photoacoustic microscopy system.

    Science.gov (United States)

    Erfanzadeh, Mohsen; Kumavor, Patrick D; Zhu, Quing

    2018-03-01

    The development of low-cost and fast photoacoustic microscopy systems enhances the clinical applicability of photoacoustic imaging systems. To this end, we present a laser scanning laser diode-based photoacoustic microscopy system. In this system, a 905 nm, 325 W maximum output peak power pulsed laser diode with 50 ns pulsewidth is utilized as the light source. A combination of aspheric and cylindrical lenses is used for collimation of the laser diode beam. Two galvanometer scanning mirrors steer the beam across a focusing aspheric lens. The lateral resolution of the system was measured to be ∼21 μm using edge spread function estimation. No averaging was performed during data acquisition. The imaging speed is ∼370 A-lines per second. Photoacoustic microscopy images of human hairs, ex vivo mouse ear, and ex vivo porcine ovary are presented to demonstrate the feasibility and potentials of the proposed system.

  14. QUANTITATIVE CONFOCAL LASER SCANNING MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Merete Krog Raarup

    2011-05-01

    Full Text Available This paper discusses recent advances in confocal laser scanning microscopy (CLSM for imaging of 3D structure as well as quantitative characterization of biomolecular interactions and diffusion behaviour by means of one- and two-photon excitation. The use of CLSM for improved stereological length estimation in thick (up to 0.5 mm tissue is proposed. The techniques of FRET (Fluorescence Resonance Energy Transfer, FLIM (Fluorescence Lifetime Imaging Microscopy, FCS (Fluorescence Correlation Spectroscopy and FRAP (Fluorescence Recovery After Photobleaching are introduced and their applicability for quantitative imaging of biomolecular (co-localization and trafficking in live cells described. The advantage of two-photon versus one-photon excitation in relation to these techniques is discussed.

  15. Investigation into scanning tunnelling luminescence microscopy

    CERN Document Server

    Manson-Smith, S K

    2001-01-01

    This work reports on the development of a scanning tunnelling luminescence (STL) microscope and its application to the study of Ill-nitride semiconductor materials used in the production of light emitting devices. STL microscopy is a technique which uses the high resolution topographic imaging capabilities of the scanning tunnelling microscope (STM) to generate high resolution luminescence images. The STM tunnelling current acts as a highly localised source of electrons (or holes) which generates luminescence in certain materials. Light generated at the STM tunnelling junction is collected concurrently with the height variation of the tunnelling probe as it is scanned across a sample surface, producing simultaneous topographic and luminescence images. Due to the very localised excitation source, high resolution luminescence images can be obtained. Spectroscopic resolution can be obtained by using filters. Additionally, the variation of luminescence intensity with tunnel current and with bias voltage can provi...

  16. Multifunctional scanning ion conductance microscopy.

    Science.gov (United States)

    Page, Ashley; Perry, David; Unwin, Patrick R

    2017-04-01

    Scanning ion conductance microscopy (SICM) is a nanopipette-based technique that has traditionally been used to image topography or to deliver species to an interface, particularly in a biological setting. This article highlights the recent blossoming of SICM into a technique with a much greater diversity of applications and capability that can be used either standalone, with advanced control (potential-time) functions, or in tandem with other methods. SICM can be used to elucidate functional information about interfaces, such as surface charge density or electrochemical activity (ion fluxes). Using a multi-barrel probe format, SICM-related techniques can be employed to deposit nanoscale three-dimensional structures and further functionality is realized when SICM is combined with scanning electrochemical microscopy (SECM), with simultaneous measurements from a single probe opening up considerable prospects for multifunctional imaging. SICM studies are greatly enhanced by finite-element method modelling for quantitative treatment of issues such as resolution, surface charge and (tip) geometry effects. SICM is particularly applicable to the study of living systems, notably single cells, although applications extend to materials characterization and to new methods of printing and nanofabrication. A more thorough understanding of the electrochemical principles and properties of SICM provides a foundation for significant applications of SICM in electrochemistry and interfacial science.

  17. Scanning Electrochemical Microscopy in Neuroscience

    Science.gov (United States)

    Schulte, Albert; Nebel, Michaela; Schuhmann, Wolfgang

    2010-07-01

    This article reviews recent work involving the application of scanning electrochemical microscopy (SECM) to the study of individual cultured living cells, with an emphasis on topographical and functional imaging of neuronal and secretory cells of the nervous and endocrine system. The basic principles of biological SECM and associated negative amperometric-feedback and generator/collector-mode SECM imaging are discussed, and successful use of the methodology for screening soft and fragile membranous objects is outlined. The drawbacks of the constant-height mode of probe movement and the benefits of the constant-distance mode of SECM operation are described. Finally, representative examples of constant-height and constant-distance mode SECM on a variety of live cells are highlighted to demonstrate the current status of single-cell SECM in general and of SECM in neuroscience in particular.

  18. Scanning Probe Microscopy of Graphene

    Science.gov (United States)

    Tautz, Pamela

    2011-10-01

    Scanning tunneling microscopy has been used to study the unusual electronic properties of graphene. In an effort to support the graphene with minimal interaction with the substrate, we used a hexagonal boron nitride (hBN) substrate. To minimize contaminants between the CVD graphene and boron nitride, the graphene samples were cleaned with distilled water and isopropanol prior to transfer to hBN substrate. We have also examined the growth of graphene flakes by chemical vapor deposition. In particular, we examined the relationship between the orientations of the first and second layer of CVD grown graphene. We found the growth mechanism preferentially resulted in rotations of 9^o or less indicating flakes with first and second layers aligned.

  19. INFLUENCE OF FILM STRUCTURE AND LIGHT ON CHARGE TRAPPING AND DISSIPATION DYNAMICS IN SPUN-CAST ORGANIC THIN-FILM TRANSISTORS MEASURED BY SCANNING KELVIN PROBE MICROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Teague, L.; Moth, M.; Anthony, J.

    2012-05-03

    Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in I{sub SD} during operation (V{sub G}=-40 V, V{sub SD}= -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.

  20. Correlated Light Microscopy and Electron Microscopy

    NARCIS (Netherlands)

    Sjollema, Klaas A.; Schnell, Ulrike; Kuipers, Jeroen; Kalicharan, Ruby; Giepmans, Ben N. G.; MullerReichert, T; Verkade, P

    2012-01-01

    Understanding where, when, and how biomolecules (inter)act is crucial to uncover fundamental mechanisms in cell biology. Recent developments in fluorescence light microscopy (FLM) allow protein imaging in living cells and at the near molecular level. However, fluorescence microscopy only reveals

  1. Light-modulated scanning tunneling microscopy studied on photoinduced carrier generations at PbI2/perovskite interface of perovskite solar cells

    Science.gov (United States)

    Chiu, Ya-Ping; Shih, Min-Chuan; Li, Shao-Sian; Hsieh, Cheng-Hua; Wang, Ying-Chiao; Yang, Hung-Duen; Chang, Chia-Seng; Chen, Chun-Wei

    Perovskite solar devices based on CH3NH3PbX3 (X = Cl, Br, I) have recently shown tremendous efficiency enhancements up to 20% in photovoltaic applications. The presence of PbI2 in perovskite films has been found to affect the charge carrier transport behaviors and device performance of perovskite solar cells. In this work, we employed the unique ability of light-modulated scanning tunneling microscopy (LM-STM) technique to dircetly reveal the correlation of the nanoscaled compositional distributions and photo-induced interfacial electronic structures at the PbI2/perovskite interface of perovskite grains under light illumination. The result reveals the important role of the optimum PbI2 passivation layers (a thickness less than 20 nm) on the charge separation and recombination at perovskite crystal grains. The unique LM-STM technique demonstartes great potential for application in the future exploring photovoltaic systems.

  2. EFFECTS OF CHEMICAL PROCESSING AND OXIDE ETHYLENE STERILIZATION ON CORTICAL AND CANCELLOUS RAT BONE: A LIGHT AND ELECTRON SCANNING MICROSCOPY STUDY.

    Science.gov (United States)

    Castiglia, Marcello Teixeira; da Silva, Juliano Voltarelli F; Frezarim Thomazini, José Armendir; Volpon, José Batista

    2009-01-01

    To evaluate, under microscopic examination, the structural changes displayed by the trabecular and cortical bones after being processed chemically and sterilized by ethylene oxide. Samples of cancellous and cortical bones obtained from young female albinus rats (Wistar) were assigned to four groups according to the type of treatment: Group I- drying; Group II- drying and ethylene oxide sterilization; III- chemical treatment; IV- chemical treatment and ethylene oxide sterilization. Half of this material was analyzed under ordinary light microscope and the other half using scanning electron microscopy. In all the samples, regardless the group, there was good preservation of the general morphology. For samples submitted to the chemical processing there was better preservation of the cellular content, whereas there was amalgamation of the fibres when ethylene oxide was used. Treatment with ethylene oxide caused amalgamation of the fibers, possibly because of heating and the chemical treatment contributed to a better cellular preservation of the osseous structure.

  3. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1995-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in STM I, these studies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described in chapters on scanning force microscopy, magnetic force microscopy, and scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Together, the two volumes give a comprehensive account of experimental aspects of STM. They provide essential reading and reference material for all students and researchers involved in this field. In this second edition the text has been updated and new methods are discussed.

  4. Scanning tunneling microscopy II further applications and related scanning techniques

    CERN Document Server

    Güntherodt, Hans-Joachim

    1992-01-01

    Scanning Tunneling Microscopy II, like its predecessor, presents detailed and comprehensive accounts of the basic principles and broad range of applications of STM and related scanning probe techniques. The applications discussed in this volume come predominantly from the fields of electrochemistry and biology. In contrast to those described in Vol. I, these sudies may be performed in air and in liquids. The extensions of the basic technique to map other interactions are described inchapters on scanning force microscopy, magnetic force microscopy, scanning near-field optical microscopy, together with a survey of other related techniques. Also described here is the use of a scanning proximal probe for surface modification. Togehter, the two volumes give a comprehensive account of experimental aspcets of STM. They provide essentialreading and reference material for all students and researchers involvedin this field.

  5. Introduction to scanning tunneling microscopy

    CERN Document Server

    Chen, C Julian

    2008-01-01

    The scanning tunneling and the atomic force microscope, both capable of imaging individual atoms, were crowned with the Physics Nobel Prize in 1986, and are the cornerstones of nanotechnology today. This is a thoroughly updated version of this 'bible' in the field.

  6. Qualitative histologic evaluation of the tissue reaction to the polyurethane resin (ricinus communis - based biopolymer implantation assessed by light and scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Gustavo Campos Belmonte

    2013-01-01

    Full Text Available The tissue reaction of bone tissue accessed by light microscopy and scanning electron microscopy (SEM images after polyurethane resin implantation is presented in this study. Twenty four male rabbits were used, divided into two groups of 12 animals each (experimental group and control group in which full-thickness cranial defect was surgically created. At 30 and 90 days post operation 6 animals of each group were euthanized and bone samples were removed for analysis. The microscopic results indicated no inflammatory foreign body reaction, a perfect union between the polymer and surgical bone bed surface, lack of bone resorption and presence of a thin layer of osteogenic material covering the polymer surface in contact with the surgical bone bed. The SEM images demonstrate the porosity of the resin, with diameters from 120 to 500 µm. This important feature of this polymer is associated with its osteoconductivity, allowing the bone growth inside it, improving the integration between the material and bone tissue. These results confirm that polyurethane resin derived from Ricinuscommunis is an excellent bone substitute for use in repair surgery for great bone losses.

  7. Spatially Resolved Imaging on Photocarrier Generations and Band Alignments at Perovskite/PbI2 Heterointerfaces of Perovskite Solar Cells by Light-Modulated Scanning Tunneling Microscopy.

    Science.gov (United States)

    Shih, Min-Chuan; Li, Shao-Sian; Hsieh, Cheng-Hua; Wang, Ying-Chiao; Yang, Hung-Duen; Chiu, Ya-Ping; Chang, Chia-Seng; Chen, Chun-Wei

    2017-02-08

    The presence of the PbI2 passivation layers at perovskite crystal grains has been found to considerably affect the charge carrier transport behaviors and device performance of perovskite solar cells. This work demonstrates the application of a novel light-modulated scanning tunneling microscopy (LM-STM) technique to reveal the interfacial electronic structures at the heterointerfaces between CH3NH3PbI3 perovskite crystals and PbI2 passivation layers of individual perovskite grains under light illumination. Most importantly, this technique enabled the first observation of spatially resolved mapping images of photoinduced interfacial band bending of valence bands and conduction bands and the photogenerated electron and hole carriers at the heterointerfaces of perovskite crystal grains. By systematically exploring the interfacial electronic structures of individual perovskite grains, enhanced charge separation and reduced back recombination were observed when an optimal design of interfacial PbI2 passivation layers consisting of a thickness less than 20 nm at perovskite crystal grains was applied.

  8. Scanning Electron Microscopy in modern dentistry research

    OpenAIRE

    Paradella, Thaís Cachuté; Unesp-FOSJC; Bottino, Marco Antonio; Unesp-FOSJC

    2012-01-01

    The purpose of this article was to review the usage of Scanning Electron Microscopy (SEM) in dentistry research nowadays, through a careful and updated literature review. By using the key-words Scanning Electron Microscopy and one of the following areas of research in dentistry (Endodontics, Periodontics and Implant), in international database (PubMed), in the year of 2012 (from January to September), a total of 112 articles were found. This data was tabled and the articles were classified ac...

  9. Differential-concentration scanning ion conductance microscopy

    OpenAIRE

    Perry, David; Page, Ashley; Chen, Baoping; Frenguelli, Bruno G.; Unwin, Patrick R.

    2017-01-01

    Scanning ion conductance microscopy (SICM) is a nanopipette-based scanning probe microscopy technique that utilizes the ionic current flowing between an electrode inserted inside a nanopipette probe containing electrolyte solution and a second electrode placed in a bulk electrolyte bath, to provide information on a substrate of interest. For most applications to date, the composition and concentration of the electrolyte inside and outside the nanopipette is identical, but it is shown herein t...

  10. Towards high-speed scanning tunneling microscopy

    NARCIS (Netherlands)

    Tabak, Femke Chantal

    2013-01-01

    In this thesis, two routes towards high-speed scanning tunneling microscopy (STM) are described. The first possibility for high-speed scanning that is discussed is the use of MEMS (Micro-Electro Mechanical Systems) devices as high-speed add-ons in STM microscopes. The functionality of these devices

  11. Spiral scanning method for atomic force microscopy.

    Science.gov (United States)

    Hung, Shao-Kang

    2010-07-01

    A spiral scanning method is proposed for atomic force microscopy with thoroughgoing analysis and implementation. Comparing with the traditional line-by-line scanning method, the spiral scanning method demonstrates higher imaging speed, minor image distortion, and lower acceleration, which can damage the piezoelectric scanner. Employing the spiral scanning method to replace the line-by-line scanning method, the experiment shows that the time to complete an imaging cycle can be reduced from 800 s to 314 s without sacrificing the image resolution.

  12. Scanning electron microscopy of bone.

    Science.gov (United States)

    Boyde, Alan

    2012-01-01

    This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

  13. Spatial light interference microscopy (SLIM).

    Science.gov (United States)

    Wang, Zhuo; Millet, Larry; Mir, Mustafa; Ding, Huafeng; Unarunotai, Sakulsuk; Rogers, John; Gillette, Martha U; Popescu, Gabriel

    2011-01-17

    We present spatial light interference microscopy (SLIM) as a new optical microscopy technique, capable of measuring nanoscale structures and dynamics in live cells via interferometry. SLIM combines two classic ideas in light imaging: Zernike's phase contrast microscopy, which renders high contrast intensity images of transparent specimens, and Gabor's holography, where the phase information from the object is recorded. Thus, SLIM reveals the intrinsic contrast of cell structures and, in addition, renders quantitative optical path-length maps across the sample. The resulting topographic accuracy is comparable to that of atomic force microscopy, while the acquisition speed is 1,000 times higher. We illustrate the novel insight into cell dynamics via SLIM by experiments on primary cell cultures from the rat brain. SLIM is implemented as an add-on module to an existing phase contrast microscope, which may prove instrumental in impacting the light microscopy field at a large scale.

  14. CLAFEM: Correlative light atomic force electron microscopy.

    Science.gov (United States)

    Janel, Sébastien; Werkmeister, Elisabeth; Bongiovanni, Antonino; Lafont, Frank; Barois, Nicolas

    2017-01-01

    Atomic force microscopy (AFM) is becoming increasingly used in the biology field. It can give highly accurate topography and biomechanical quantitative data, such as adhesion, elasticity, and viscosity, on living samples. Nowadays, correlative light electron microscopy is a must-have tool in the biology field that combines different microscopy techniques to spatially and temporally analyze the structure and function of a single sample. Here, we describe the combination of AFM with superresolution light microscopy and electron microscopy. We named this technique correlative light atomic force electron microscopy (CLAFEM) in which AFM can be used on fixed and living cells in association with superresolution light microscopy and further processed for transmission or scanning electron microscopy. We herein illustrate this approach to observe cellular bacterial infection and cytoskeleton. We show that CLAFEM brings complementary information at the cellular level, from on the one hand protein distribution and topography at the nanometer scale and on the other hand elasticity at the piconewton scales to fine ultrastructural details. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Comparative pattern of growth and development of Echinostoma paraensei (Digenea: Echinostomatidae) in hamster and Wistar rat using light and confocal laser scanning microscopy.

    Science.gov (United States)

    Souza, Joyce G R; Garcia, Juberlan S; Gomes, Ana Paula N; Machado-Silva, José Roberto; Maldonado, Arnaldo

    2017-12-01

    Echinostoma paraensei (Digenea: Echinostomatidae) lives in the duodenum and bile duct of rodents and is reported as a useful model for studies on the biology of flatworms. Here, we compared the growth and development of pre and post ovigerous worms collected 3, 7, 14 and 21 days post infection from experimentally infected hamster (permissive host) and Wistar rat (less permissive hosts). Linear measurements and ratios were examined by light (morphology and morphometry) and confocal laser scanning microscopy. At day 3, either worm from hamsters or rats were small with poorly developed gonads. At seven day, worms increased in size and morphometric differences between hosts are statistically significant after this time. In addition, adult worms (14 and 21 days of age) harvested from hamster showed developed gonads and vitelline glands laterally distributed on the body, whereas worms from rat showed atrophied reproductive system characterized by underdeveloped vitelline glands and stunted ovary. The worm rate recovery in rat decreased from 29.3% (day 7) to 20.6% (day 14) and 8% (day 21), whilst it remained around 37% in hamster. In conclusion, this is the first appointment demonstrating that low permissiveness influences the reproductive system of echinostome since the immature stages of development. The phenotypic analysis evidenced that hamster provides a more favorable microenvironment for gonads development than rat, confirming golden hamster as a permissive host, whereas Wistar rat is less permissive host. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A Characterization of Laponite Nanoclays by Dynamic Light Scattering, Scanning Electron Microscopy, and Cation Exchange Capacity by UV-Visible Spectroscopy

    Science.gov (United States)

    Arnold, Randall

    Four different Laponite clays were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), and UV-Visible spectroscopy to determine the cation exchange capacity (CEC) to provide a methodology of analysis for other clays. DLS and SEM were utilized to observe the sizes, shape, and inter-particle interactions for the different clays. UV-Visible spectroscopy was implemented to characterize the CEC of each clay via a complexometric reaction with calcium. DLS provided limitedly consistent results due to a disparity in the translational diffusion of particles in suspension due to high aspect ratios and electroviscious forces; however, SEM provided high-resolution images of various particles and agglomerates with unique insight into the intra-particle edge-face, edge-edge, and face-face interactions driven by various electrochemical forces. The experimentally determined CECs, while consistently elevated above reported values, provide accurate first-pass estimations by a direct cation exchange methodology. Advancement of this work might include Mie scattering of angular dependence for DLS, as well as a correction for the electric double layer of the platelets; field emission SEM for microanalysis of single platelets and agglomerates; and using zeta potential to develop a methodology of observing stability and CEC of cation-loaded uncharacterized clays. Establishing a methodology for determining the CEC and cation loading provides the most valuable advancement towards characterizing other clays and linking cation loading to the zeta potential and colloidal stability.

  17. A Review of Three-Dimensional Scanning Near-Field Optical Microscopy (3D-SNOM and Its Applications in Nanoscale Light Management

    Directory of Open Access Journals (Sweden)

    Paul Bazylewski

    2017-09-01

    Full Text Available In this article, we present an overview of aperture and apertureless type scanning near-field optical microscopy (SNOM techniques that have been developed, with a focus on three-dimensional (3D SNOM methods. 3D SNOM has been undertaken to image the local distribution (within ~100 nm of the surface of the electromagnetic radiation scattered by random and deterministic arrays of metal nanostructures or photonic crystal waveguides. Individual metal nanoparticles and metal nanoparticle arrays exhibit unique effects under light illumination, including plasmon resonance and waveguiding properties, which can be directly investigated using 3D-SNOM. In the second part of this article, we will review a few applications in which 3D-SNOM has proven to be useful for designing and understanding specific nano-optoelectronic structures. Examples include the analysis of the nano-optical response phonetic crystal waveguides, aperture antennae and metal nanoparticle arrays, as well as the design of plasmonic solar cells incorporating random arrays of copper nanoparticles as an optical absorption enhancement layer, and the use of 3D-SNOM to probe multiple components of the electric and magnetic near-fields without requiring specially designed probe tips. A common denominator of these examples is the added value provided by 3D-SNOM in predicting the properties-performance relationship of nanostructured systems.

  18. Semiconductor Surface Characterization by Scanning Probe Microscopies

    Science.gov (United States)

    2001-01-01

    potentiometry (STP)8 and ballistic electron emission microscopy (BEEM)9 which allow mapping of lateral surface potential and local subsurface Schottky...A.P.Fein. "Tunneling Spectroscopy of the Si(1 1 1)2xl Surface", Surf.Sci. 181, 295- 306, 1987. 8. P.Muralt, D.W.Pohl, "Scanning tunneling potentiometry

  19. Scanning electron microscopy study of Trichomonas gallinae.

    Science.gov (United States)

    Tasca, Tiana; De Carli, Geraldo A

    2003-12-01

    A scanning electron microscopy (SEM) study of Trichomonas gallinae (Rivolta, 1878), provided more information about the morphology of this flagellated protozoan. SEM showed the morphological features of the trophozoites; the emergence of the anterior flagella, the structure of the undulating membrane, the position and shape of the pelta, axostyle and posterior flagellum. Of special interest were the pseudocyst forms.

  20. Aberration corrected Lorentz scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    McVitie, S., E-mail: stephen.mcvitie@glasgow.ac.uk; McGrouther, D.; McFadzean, S.; MacLaren, D.A.; O’Shea, K.J.; Benitez, M.J.

    2015-05-15

    We present results from an aberration corrected scanning transmission electron microscope which has been customised for high resolution quantitative Lorentz microscopy with the sample located in a magnetic field free or low field environment. We discuss the innovations in microscope instrumentation and additional hardware that underpin the imaging improvements in resolution and detection with a focus on developments in differential phase contrast microscopy. Examples from materials possessing nanometre scale variations in magnetisation illustrate the potential for aberration corrected Lorentz imaging as a tool to further our understanding of magnetism on this lengthscale. - Highlights: • Demonstration of nanometre scale resolution in magnetic field free environment using aberration correction in the scanning transmission electron microscope (STEM). • Implementation of differential phase contrast mode of Lorentz microscopy in aberration corrected STEM with improved sensitivity. • Quantitative imaging of magnetic induction of nanostructures in amorphous and cross-section samples.

  1. Scanning Ion Conductance Microscopy of Live Keratinocytes

    Science.gov (United States)

    Hegde, V.; Mason, A.; Saliev, T.; Smith, F. J. D.; McLean, W. H. I.; Campbell, P. A.

    2012-07-01

    Scanning ion conductance microscopy (SICM) is perhaps the least well known technique from the scanning probe microscopy (SPM) family of instruments. As with its more familiar counterpart, atomic force microscopy (AFM), the technique provides high-resolution topographic imaging, with the caveat that target structures must be immersed in a conducting solution so that a controllable ion current may be utilised as the basis for feedback. In operation, this non-contact characteristic of SICM makes it ideal for the study of delicate structures, such as live cells. Moreover, the intrinsic architecture of the instrument, incorporating as it does, a scanned micropipette, lends itself to combination approaches with complementary techniques such as patch-clamp electrophysiology: SICM therefore boasts the capability for both structural and functional imaging. For the present observations, an ICnano S system (Ionscope Ltd., Melbourn, UK) operating in 'hopping mode' was used, with the objective of assessing the instrument's utility for imaging live keratinocytes under physiological buffers. In scans employing cultured HaCaT cells (spontaneously immortalised, human keratinocytes), we compared the qualitative differences of live cells imaged with SICM and AFM, and also with their respective counterparts after chemical fixation in 4% paraformaldehyde. Characteristic surface microvilli were particularly prominent in live cell imaging by SICM. Moreover, time lapse SICM imaging on live cells revealed that changes in the pattern of microvilli could be tracked over time. By comparison, AFM imaging on live cells, even at very low contact forces (monitoring the most delicate living structures with attendant high spatial resolutions.

  2. EDITORIAL: Scanning probe microscopy: a visionary development Scanning probe microscopy: a visionary development

    Science.gov (United States)

    Demming, Anna

    2013-07-01

    amplitude modulated KPFM measurements compared with the frequency modulated mode. Rohrer and Binnig shared the Nobel Prize for Physics 'for their design of the scanning tunnelling microscope' [11]. They are widely recognized among the founding fathers of nanoscience. In an interview in 2005 Rohrer once commented on the benefits of changing fields even if it leaves you feeling a little 'lost and lonely' at first. In fact he attributed his ability to contribute his Nobel Prize winning work to science at a comparatively senior age to the fact that he had changed fields. 'You cannot be the star from the beginning, but I think what is important is that you might bring in a different way of thinking. You have a certain lightness to approach something that is the expert opinion' [2]. In nanotechnology where such a formidable range of disciplines seem to feed into the research such words may be particularly encouraging. Rohrer passed away on 16 May 2013, but the awesome legacy of his life's work continues. With the scanning tunnelling microscope the lofty eccentricities of quantum mechanical theory literally came into view, quite an inspiration. References [1] Binning G, Rohrer H, Gerber Ch and Weibel E 1982 Surface studies by scanning tunneling microscopy Phys. Rev. Lett. 49 57-61 [2] Weiss P S 2007 A conversation with Dr. Heinrich Rohrer: STM Co-inventor and one of the founding fathers of nanoscience ACS Nano 1 3-5 [3] Binnig G, Quate C F and Gerber Ch 1986 Atomic force microscope Phys. Rev. Lett. 56 930-3 [4] Maivald P, Butt H J, Gould S A C, Prater C B, Drake B, Gurley J A, Elings V B and Hansma P K 1991 Using force modulation to image surface elasticities with the atomic force microscope Nanotechnology 2 103-6 [5] Ando T 2012 High-speed atomic force microscopy coming of age Nanotechnology 23 062001 [6] Betzig E, Isaacson M, Barshatzky H, Lewis A and Lin K 1988 Super-resolution imaging with near-field scanning optical microscopy (NSOM) Ultramicroscopy 25 155-63 [7] Thio T

  3. Analysing magnetism using scanning SQUID microscopy.

    Science.gov (United States)

    Reith, P; Renshaw Wang, X; Hilgenkamp, H

    2017-12-01

    Scanning superconducting quantum interference device microscopy (SSM) is a scanning probe technique that images local magnetic flux, which allows for mapping of magnetic fields with high field and spatial accuracy. Many studies involving SSM have been published in the last few decades, using SSM to make qualitative statements about magnetism. However, quantitative analysis using SSM has received less attention. In this work, we discuss several aspects of interpreting SSM images and methods to improve quantitative analysis. First, we analyse the spatial resolution and how it depends on several factors. Second, we discuss the analysis of SSM scans and the information obtained from the SSM data. Using simulations, we show how signals evolve as a function of changing scan height, SQUID loop size, magnetization strength, and orientation. We also investigated 2-dimensional autocorrelation analysis to extract information about the size, shape, and symmetry of magnetic features. Finally, we provide an outlook on possible future applications and improvements.

  4. 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

  5. Scanning electron microscopy of molluscum contagiosum*

    OpenAIRE

    Almeida Jr,Hiram Larangeira de; Abuchaim,Martha Oliveira; Schneide, Maiko Abel; Marques, Leandra; Castro, Luis Antônio Suíta de

    2013-01-01

    Molluscum contagiosum is a disease caused by a poxvirus. It is more prevalent in children up to 5 years of age. There is a second peak of incidence in young adults. In order to examine its ultrastructure, three lesions were curetted without disruption, cut transversely with a scalpel, and routinely processed for scanning electron microscopy (SEM). The oval structure of molluscum contagiosum could be easily identified. In its core, there was a central umbilication and just below this depressio...

  6. Scanning electron microscopy of cold gases

    Science.gov (United States)

    Santra, Bodhaditya; Ott, Herwig

    2015-06-01

    Ultracold quantum gases offer unique possibilities to study interacting many-body quantum systems. Probing and manipulating such systems with ever increasing degree of control requires novel experimental techniques. Scanning electron microscopy is a high resolution technique which can be used for in situ imaging, single site addressing in optical lattices and precision density engineering. Here, we review recent advances and achievements obtained with this technique and discuss future perspectives.

  7. Noninvasive redox and back-scattered light imaging of keratocyte cells in the cornea: two-photon excitation and scanning slit confocal microscopy

    Science.gov (United States)

    Masters, Barry R.

    1995-04-01

    The ability to image and monitor the metabolic activity of keratocytes is important for the investigation of wound healing and repair mechanisms in the cornea. After laser refractive surgery there is activation of the stromal keratocytes in the human cornea. Two-photon excitation laser scanning microscopy was used to monitor the NAD(P)H levels in keratocytes in the cornea. The autofluorescence was confirmed to be mostly of NAD(P)H origin by treatment with cyanide which caused an increase in the fluorescence by a factor of two. We used a real-time scanning slit confocal microscope to image the distribution of keratocytes in the full thickness of the cornea. This microscope has the ability to image the cellular processes as well as the nuclei of the stromal keratocytes. Noninvasive optical imaging may provide a useful tool to investigate keratocyte activation after laser surgery or wound healing.

  8. Interferometric Synthetic Aperture Microscopy: Computed Imaging for Scanned Coherent Microscopy

    Directory of Open Access Journals (Sweden)

    Stephen A. Boppart

    2008-06-01

    Full Text Available Three-dimensional image formation in microscopy is greatly enhanced by the use of computed imaging techniques. In particular, Interferometric Synthetic Aperture Microscopy (ISAM allows the removal of out-of-focus blur in broadband, coherent microscopy. Earlier methods, such as optical coherence tomography (OCT, utilize interferometric ranging, but do not apply computed imaging methods and therefore must scan the focal depth to acquire extended volumetric images. ISAM removes the need to scan the focus by allowing volumetric image reconstruction from data collected at a single focal depth. ISAM signal processing techniques are similar to the Fourier migration methods of seismology and the Fourier reconstruction methods of Synthetic Aperture Radar (SAR. In this article ISAM is described and the close ties between ISAM and SAR are explored. ISAM and a simple strip-map SAR system are placed in a common mathematical framework and compared to OCT and radar respectively. This article is intended to serve as a review of ISAM, and will be especially useful to readers with a background in SAR.

  9. Scanning Probe Microscopy of Organic Solar Cells

    Science.gov (United States)

    Reid, Obadiah G.

    Nanostructured composites of organic semiconductors are a promising class of materials for the manufacture of low-cost solar cells. Understanding how the nanoscale morphology of these materials affects their efficiency as solar energy harvesters is crucial to their eventual potential for large-scale deployment for primary power generation. In this thesis we describe the use of optoelectronic scanning-probe based microscopy methods to study this efficiency-structure relationship with nanoscale resolution. In particular, our objective is to make spatially resolved measurements of each step in the power conversion process from photons to an electric current, including charge generation, transport, and recombination processes, and correlate them with local device structure. We have achieved two aims in this work: first, to develop and apply novel electrically sensitive scanning probe microscopy experiments to study the optoelectronic materials and processes discussed above; and second, to deepen our understanding of the physics underpinning our experimental techniques. In the first case, we have applied conductive-, and photoconductive atomic force (cAFM & pcAFM) microscopy to measure both local photocurrent collection and dark charge transport properties in a variety of model and novel organic solar cell composites, including polymer/fullerene blends, and polymer-nanowire/fullerene blends, finding that local heterogeneity is the rule, and that improvements in the uniformity of specific beneficial nanostructures could lead to large increases in efficiency. We have used scanning Kelvin probe microscopy (SKPM) and time resolved-electrostatic force microscopy (trEFM) to characterize all-polymer blends, quantifying their sensitivity to photochemical degradation and the subsequent formation of local charge traps. We find that while trEFM provides a sensitive measure of local quantum efficiency, SKPM is generally unsuited to measurements of efficiency, less sensitive than tr

  10. Light microscopy - Methods and protocols

    Directory of Open Access Journals (Sweden)

    CarloAlberto Redi

    2011-11-01

    Full Text Available The first part of the book (six chapters is devoted to some selected applications of bright-field microscopy while the second part (eight chapters to some fluorescence microscopy studies. Both animal and plant biology investigations are presented covering multiple fields like immunology, cell signaling, cancer biology and, surprisingly to me, ecology. This chapter is titled: Light microscopy in aquatic ecology: Methods for plankton communities studies and it is due to Maria Carolina S. Soares and colleagues from the Laboratory of Aquatic Ecology, Dept. of Biology, Federal University of Juiz de Fora (Brazil. Here they present methods to quantify the different component of planktonic communities in a step-by-step manner so that virus, bacteria, algae and animals pertaining to different taxa can be recognized and the contribution they made to the plankton composition evaluated. It descends that even how the plankton composition is changing due to environmental variations can be accurately determined....

  11. Light Sheet Fluorescence Microscopy (LSFM)

    OpenAIRE

    Adams, Michael W.; Loftus, Andrew F.; Dunn, Sarah E.; Joens, Matthew S.; Fitzpatrick, James A. J.

    2015-01-01

    The development of confocal microscopy techniques introduced the ability to optically section fluorescent samples in the axial dimension, perpendicular to the image plane. These approaches, via the placement of a pinhole in the conjugate image plane, provided superior resolution in the axial (z) dimension resulting in nearly isotropic optical sections. However, increased axial resolution, via pinhole optics, comes at the cost of both speed and excitation efficiency. Light Sheet Fluorescent Mi...

  12. Chemical Phenomena of Atomic Force Microscopy Scanning.

    Science.gov (United States)

    Ievlev, Anton V; Brown, Chance; Burch, Matthew J; Agar, Joshua C; Velarde, Gabriel A; Martin, Lane W; Maksymovych, Petro; Kalinin, Sergei V; Ovchinnikova, Olga S

    2018-02-12

    Atomic force microscopy is widely used for nanoscale characterization of materials by scientists worldwide. The long-held belief of ambient AFM is that the tip is generally chemically inert but can be functionalized with respect to the studied sample. This implies that basic imaging and scanning procedures do not affect surface and bulk chemistry of the studied sample. However, an in-depth study of the confined chemical processes taking place at the tip-surface junction and the associated chemical changes to the material surface have been missing as of now. Here, we used a hybrid system that combines time-of-flight secondary ion mass spectrometry with an atomic force microscopy to investigate the chemical interactions that take place at the tip-surface junction. Investigations showed that even basic contact mode AFM scanning is able to modify the surface of the studied sample. In particular, we found that the silicone oils deposited from the AFM tip into the scanned regions and spread to distances exceeding 15 μm from the tip. These oils were determined to come from standard gel boxes used for the storage of the tips. The explored phenomena are important for interpreting and understanding results of AFM mechanical and electrical studies relying on the state of the tip-surface junction.

  13. Hollow-tip scanning photoelectron microscopy

    Science.gov (United States)

    Cherkun, A. P.; Mironov, B. N.; Aseyev, S. A.; Chekalin, S. V.

    2014-07-01

    A new type of microscopy based on scanning in vacuum by a beam of charged particles transmitted through a hollow probe has been implemented. This approach provides controllable motion of spatially localized ion, electron, molecular (atomic), and soft X-ray beams and investigation of the surface in the shear force mode. In the photoelectron mode, in which electrons are transmitted through a 2-μm quartz capillary, a surface profile of gadolinium irradiated by 400-nm femtosecond laser pulses has been visualized with a subwave spatial resolution. The new method of microscopy opens an opportunity of investigations in the field of nanometer local photodesorption of molecular ions (one of the last ideas of V.S. Letokhov).

  14. Soft stylus probes for scanning electrochemical microscopy.

    Science.gov (United States)

    Cortés-Salazar, Fernando; Träuble, Markus; Li, Fei; Busnel, Jean-Marc; Gassner, Anne-Laure; Hojeij, Mohamad; Wittstock, Gunther; Girault, Hubert H

    2009-08-15

    A soft stylus microelectrode probe has been developed to carry out scanning electrochemical microscopy (SECM) of rough, tilted, and large substrates in contact mode. It is fabricated by first ablating a microchannel in a polyethylene terephthalate thin film and filling it with a conductive carbon ink. After curing the carbon track and lamination with a polymer film, the V-shaped stylus was cut thereby forming a probe, with the cross section of the carbon track at the tip being exposed either by UV-photoablation machining or by blade cutting followed by polishing to produce a crescent moon-shaped carbon microelectrode. The probe properties have been assessed by cyclic voltammetry, approach curves, and line scans over electrochemically active and inactive substrates of different roughness. The influence of probe bending on contact mode imaging was then characterized using simple patterns. Boundary element method simulations were employed to rationalize the distance-dependent electrochemical response of the soft stylus probes.

  15. Surface morphology of Trichinella spiralis by scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C.W. (State Univ. of New York, Stony Brook); Ledbetter, M.C.

    1980-02-01

    The surface morphology of larval and adult Trichinella spiralis was studied by scanning electron microscopy (SEM) of fixed, dried, and metal-coated specimens. The results are compared with those found earlier by various investigators using light and transmission electron microscopy. Some morphological features reported here are revealed uniquely by SEM. These include the pores of the cephalic sense organs, the character of secondary cuticular folds, variations of the hypodermal gland cell openings or pores, and the presence of particles on the copulatory bell.

  16. Light Microscopy at Maximal Precision

    Science.gov (United States)

    Bierbaum, Matthew; Leahy, Brian D.; Alemi, Alexander A.; Cohen, Itai; Sethna, James P.

    2017-10-01

    Microscopy is the workhorse of the physical and life sciences, producing crisp images of everything from atoms to cells well beyond the capabilities of the human eye. However, the analysis of these images is frequently little more accurate than manual marking. Here, we revolutionize the analysis of microscopy images, extracting all the useful information theoretically contained in a complex microscope image. Using a generic, methodological approach, we extract the information by fitting experimental images with a detailed optical model of the microscope, a method we call parameter extraction from reconstructing images (PERI). As a proof of principle, we demonstrate this approach with a confocal image of colloidal spheres, improving measurements of particle positions and radii by 10-100 times over current methods and attaining the maximum possible accuracy. With this unprecedented accuracy, we measure nanometer-scale colloidal interactions in dense suspensions solely with light microscopy, a previously impossible feat. Our approach is generic and applicable to imaging methods from brightfield to electron microscopy, where we expect accuracies of 1 nm and 0.1 pm, respectively.

  17. Differential-Concentration Scanning Ion Conductance Microscopy.

    Science.gov (United States)

    Perry, David; Page, Ashley; Chen, Baoping; Frenguelli, Bruno G; Unwin, Patrick R

    2017-11-21

    Scanning ion conductance microscopy (SICM) is a nanopipette-based scanning probe microscopy technique that utilizes the ionic current flowing between an electrode inserted inside a nanopipette probe containing electrolyte solution and a second electrode placed in a bulk electrolyte bath, to provide information on a substrate of interest. For most applications to date, the composition and concentration of the electrolyte inside and outside the nanopipette is identical, but it is shown herein that it can be very beneficial to lift this restriction. In particular, an ionic concentration gradient at the end of the nanopipette, generates an ionic current with a greatly reduced electric field strength, with particular benefits for live cell imaging. This differential concentration mode of SICM (ΔC-SICM) also enhances surface charge measurements and provides a new way to carry out reaction mapping measurements at surfaces using the tip for simultaneous delivery and sensing of the reaction rate. Comprehensive finite element method (FEM) modeling has been undertaken to enhance understanding of SICM as an electrochemical cell and to enable the interpretation and optimization of experiments. It is shown that electroosmotic flow (EOF) has much more influence on the nanopipette response in the ΔC-SICM configuration compared to standard SICM modes. The general model presented advances previous treatments, and it provides a framework for quantitative SICM studies.

  18. Correlative Light and Scanning Electron Microscopy for Observing the Three-Dimensional Ultrastructure of Membranous Cell Organelles in Relation to Their Molecular Components

    Science.gov (United States)

    Koga, Daisuke; Kusumi, Satoshi; Bochimoto, Hiroki; Watanabe, Tsuyoshi; Ushiki, Tatsuo

    2015-01-01

    Although the osmium maceration method has been used to observe three-dimensional (3D) structures of membranous cell organelles with scanning electron microscopy (SEM), the use of osmium tetroxide for membrane fixation and the removal of cytosolic soluble proteins largely impairs the antigenicity of molecules in the specimens. In the present study, we developed a novel method to combine cryosectioning with the maceration method for correlative immunocytochemical analysis. We first immunocytochemically stained a semi-thin cryosection cut from a pituitary tissue block with a cryo-ultramicrotome, according to the Tokuyasu method, before preparing an osmium-macerated specimen from the remaining tissue block. Correlative microscopy was performed by observing the same area between the immunostained section and the adjacent face of the tissue block. Using this correlative method, we could accurately identify the gonadotropes of pituitary glands in various experimental conditions with SEM. At 4 weeks after castration, dilated cisternae of rough endoplasmic reticulum (RER) were distributed throughout the cytoplasm. On the other hand, an extremely dilated cisterna of the RER occupied the large region of the cytoplasm at 12 weeks after castration. This novel method has the potential to analyze the relationship between the distribution of functional molecules and the 3D ultrastructure in different composite tissues. PMID:26374827

  19. Phase-contrast scanning transmission electron microscopy.

    Science.gov (United States)

    Minoda, Hiroki; Tamai, Takayuki; Iijima, Hirofumi; Hosokawa, Fumio; Kondo, Yukihito

    2015-06-01

    This report introduces the first results obtained using phase-contrast scanning transmission electron microscopy (P-STEM). A carbon-film phase plate (PP) with a small center hole is placed in the condenser aperture plane so that a phase shift is introduced in the incident electron waves except those passing through the center hole. A cosine-type phase-contrast transfer function emerges when the phase-shifted scattered waves interfere with the non-phase-shifted unscattered waves, which passed through the center hole before incidence onto the specimen. The phase contrast resulting in P-STEM is optically identical to that in phase-contrast transmission electron microscopy that is used to provide high contrast for weak phase objects. Therefore, the use of PPs can enhance the phase contrast of the STEM images of specimens in principle. The phase shift resulting from the PP, whose thickness corresponds to a phase shift of π, has been confirmed using interference fringes displayed in the Ronchigram of a silicon single crystal specimen. The interference fringes were found to abruptly shift at the edge of the PP hole by π. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. A correlative optical microscopy and scanning electron microscopy approach to locating nanoparticles in brain tumors.

    Science.gov (United States)

    Kempen, Paul J; Kircher, Moritz F; de la Zerda, Adam; Zavaleta, Cristina L; Jokerst, Jesse V; Mellinghoff, Ingo K; Gambhir, Sanjiv S; Sinclair, Robert

    2015-01-01

    The growing use of nanoparticles in biomedical applications, including cancer diagnosis and treatment, demands the capability to exactly locate them within complex biological systems. In this work a correlative optical and scanning electron microscopy technique was developed to locate and observe multi-modal gold core nanoparticle accumulation in brain tumor models. Entire brain sections from mice containing orthotopic brain tumors injected intravenously with nanoparticles were imaged using both optical microscopy to identify the brain tumor, and scanning electron microscopy to identify the individual nanoparticles. Gold-based nanoparticles were readily identified in the scanning electron microscope using backscattered electron imaging as bright spots against a darker background. This information was then correlated to determine the exact location of the nanoparticles within the brain tissue. The nanoparticles were located only in areas that contained tumor cells, and not in the surrounding healthy brain tissue. This correlative technique provides a powerful method to relate the macro- and micro-scale features visible in light microscopy with the nanoscale features resolvable in scanning electron microscopy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Angular Approach Scanning Ion Conductance Microscopy.

    Science.gov (United States)

    Shevchuk, Andrew; Tokar, Sergiy; Gopal, Sahana; Sanchez-Alonso, Jose L; Tarasov, Andrei I; Vélez-Ortega, A Catalina; Chiappini, Ciro; Rorsman, Patrik; Stevens, Molly M; Gorelik, Julia; Frolenkov, Gregory I; Klenerman, David; Korchev, Yuri E

    2016-05-24

    Scanning ion conductance microscopy (SICM) is a super-resolution live imaging technique that uses a glass nanopipette as an imaging probe to produce three-dimensional (3D) images of cell surface. SICM can be used to analyze cell morphology at nanoscale, follow membrane dynamics, precisely position an imaging nanopipette close to a structure of interest, and use it to obtain ion channel recordings or locally apply stimuli or drugs. Practical implementations of these SICM advantages, however, are often complicated due to the limitations of currently available SICM systems that inherited their design from other scanning probe microscopes in which the scan assembly is placed right above the specimen. Such arrangement makes the setting of optimal illumination necessary for phase contrast or the use of high magnification upright optics difficult. Here, we describe the designs that allow mounting SICM scan head on a standard patch-clamp micromanipulator and imaging the sample at an adjustable approach angle. This angle could be as shallow as the approach angle of a patch-clamp pipette between a water immersion objective and the specimen. Using this angular approach SICM, we obtained topographical images of cells grown on nontransparent nanoneedle arrays, of islets of Langerhans, and of hippocampal neurons under upright optical microscope. We also imaged previously inaccessible areas of cells such as the side surfaces of the hair cell stereocilia and the intercalated disks of isolated cardiac myocytes, and performed targeted patch-clamp recordings from the latter. Thus, our new, to our knowledge, angular approach SICM allows imaging of living cells on nontransparent substrates and a seamless integration with most patch-clamp setups on either inverted or upright microscopes, which would facilitate research in cell biophysics and physiology. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  2. Light Sheet Fluorescence Microscopy (LSFM).

    Science.gov (United States)

    Adams, Michael W; Loftus, Andrew F; Dunn, Sarah E; Joens, Matthew S; Fitzpatrick, James A J

    2015-01-05

    The development of confocal microscopy techniques introduced the ability to optically section fluorescent samples in the axial dimension, perpendicular to the image plane. These approaches, via the placement of a pinhole in the conjugate image plane, provided superior resolution in the axial (z) dimension resulting in nearly isotropic optical sections. However, increased axial resolution, via pinhole optics, comes at the cost of both speed and excitation efficiency. Light sheet fluorescent microscopy (LSFM), a century-old idea made possible with modern developments in both excitation and detection optics, provides sub-cellular resolution and optical sectioning capabilities without compromising speed or excitation efficiency. Over the past decade, several variations of LSFM have been implemented each with its own benefits and deficiencies. Here we discuss LSFM fundamentals and outline the basic principles of several major light-sheet-based imaging modalities (SPIM, inverted SPIM, multi-view SPIM, Bessel beam SPIM, and stimulated emission depletion SPIM) while considering their biological relevance in terms of intrusiveness, temporal resolution, and sample requirements. Copyright © 2015 John Wiley & Sons, Inc.

  3. Scanning electron microscopy of molluscum contagiosum*

    Science.gov (United States)

    de Almeida Jr, Hiram Larangeira; Abuchaim, Martha Oliveira; Schneider, Maiko Abel; Marques, Leandra; de Castro, Luis Antônio Suíta

    2013-01-01

    Molluscum contagiosum is a disease caused by a poxvirus. It is more prevalent in children up to 5 years of age. There is a second peak of incidence in young adults. In order to examine its ultrastructure, three lesions were curetted without disruption, cut transversely with a scalpel, and routinely processed for scanning electron microscopy (SEM). The oval structure of molluscum contagiosum could be easily identified. In its core, there was a central umbilication and just below this depression, there was a keratinized tunnel. Under higher magnification, a proliferation similar to the epidermis was seen. Moreover, there were areas of cells disposed like a mosaic. Under higher magnification, rounded structures measuring 0.4 micron could be observed at the end of the keratinized tunnel and on the surface of the lesion. PMID:23539009

  4. Spin-polarized scanning tunnelling microscopy

    CERN Document Server

    Bode, M

    2003-01-01

    The recent experimental progress in spin-polarized scanning tunnelling microscopy (SP-STM) - a magnetically sensitive imaging technique with ultra-high resolution - is reviewed. The basics of spin-polarized electron tunnelling are introduced as they have been investigated in planar tunnel junctions for different electrode materials, i.e. superconductors, optically excited GaAs, and ferromagnets. It is shown that ferromagnets and antiferromagnets are suitable tip materials for the realization of SP-STM. Possible tip designs and modes of operations are discussed for both classes of materials. The results of recent spatially resolved measurements as performed with different magnetic probe tips and using different modes of operation are reviewed and discussed in terms of applicability to surfaces, thin films, and nanoparticles. The limits of spatial resolution, and the impact of an external magnetic field on the imaging process.

  5. A dark mode in scanning thermal microscopy

    Science.gov (United States)

    Ramiandrisoa, Liana; Allard, Alexandre; Joumani, Youssef; Hay, Bruno; Gomés, Séverine

    2017-12-01

    The need for high lateral spatial resolution in thermal science using Scanning Thermal Microscopy (SThM) has pushed researchers to look for more and more tiny probes. SThM probes have consequently become more and more sensitive to the size effects that occur within the probe, the sample, and their interaction. Reducing the tip furthermore induces very small heat flux exchanged between the probe and the sample. The measurement of this flux, which is exploited to characterize the sample thermal properties, requires then an accurate thermal management of the probe-sample system and to reduce any phenomenon parasitic to this system. Classical experimental methodologies must then be constantly questioned to hope for relevant and interpretable results. In this paper, we demonstrate and estimate the influence of the laser of the optical force detection system used in the common SThM setup that is based on atomic-force microscopy equipment on SThM measurements. We highlight the bias induced by the overheating due to the laser illumination on the measurements performed by thermoresistive probes (palladium probe from Kelvin Nanotechnology). To face this issue, we propose a new experimental procedure based on a metrological approach of the measurement: a SThM "dark mode." The comparison with the classical procedure using the laser shows that errors between 14% and 37% can be reached on the experimental data exploited to determine the heat flux transferred from the hot probe to the sample.

  6. Ultrafast Photon Counting Applied to Resonant Scanning STED Microscopy

    Science.gov (United States)

    Wu, Xundong; Toro, Ligia; Stefani, Enrico; Wu, Yong

    2014-01-01

    Summary To take full advantage of fast resonant scanning in super-resolution STimulated Emission Depletion (STED) microscopy, we have developed an ultrafast photon counting system based on a multi-giga-sample per second analog-to-digital conversion (ADC) chip that delivers an unprecedented 450 MHz pixel clock (2.2 ns pixel dwell time in each scan). The system achieves a large field of view (~50 × 50 μm) with fast scanning that reduces photobleaching, and advances the time-gated continuous wave (CW) STED technology to the usage of resonant scanning with hardware based time-gating. The assembled system provides superb signal-to-noise ratio and highly linear quantification of light that result in superior image quality. Also, the system design allows great flexibility in processing photon signals to further improve the dynamic range. In conclusion, we have constructed a frontier photon counting image acquisition system with ultrafast readout rate, excellent counting linearity, and with the capacity of realizing resonant-scanning CW-STED microscopy with on-line time-gated detection. PMID:25227160

  7. Investigations in optoelectronic image processing in scanning laser microscopy

    Science.gov (United States)

    Chaliha, Hiranya Kumar

    A considerable amount of work has been done on scann-ing laser microscopy since its applications were first pointed out by Roberts and Young[1], Minsky [2] and Davidovits et al [3]. The advent of laser has made it possible to focus an intense beam of laser light in a scanning optical microscope (SOM) [4, 5] and hence explore regions of microscopy[6] uncovered by conven-tional microscopy. In the simple SOM [7, 8, 9], the upper spatial frequency in amplitude transmittance or reflectance of an object for which transfer function is nonzero is same as that in a conventional optical microscope. However, in Type II SOM [7] or confocal SOM that employs a coherent or a point detector, the spatial frequency bandwidth is twice that obtained in a conventional microscope. Besides this confocal set-up is found to be very useful in optical sectioning and consequently in 3-D image processing[10, 11, 12] specially of biological specimens. Such systems are also suitable for studies of semiconductor materials [13], super-resolution [14] and various imaginative ways of image processing[15, 16, 17] including phase imaging[18]. A brief survey of related advances in scanning optical microscopy has been covered in the chapter 1 of the thesis. The performance of SOM may be investigated by concent-rating also on signal derived by one dimensional scan of the object specimen. This simplified mode may also be adapted to give wealth of information for biological and semiconductor specimens. Hence we have investigated the design of a scanning laser system suited specifically for studies of line scan image signals of microscopic specimens when probed through a focused laser spot. An electro-mechanical method of scanning of the object specimen has been designed with this aim in mind. Chapter 2, Part A of the thesis deals with the design consider-ations of such a system. For analysis of scan signals at a later instant of time so as to facilitate further processing, an arrangement of microprocessor

  8. Abrasion of 6 dentifrices measured by vertical scanning interference microscopy

    Science.gov (United States)

    PASCARETTI-GRIZON, Florence; MABILLEAU, Guillaume; CHAPPARD, Daniel

    2013-01-01

    Objectives The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). Material and Methods Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscopy and microanalysis characterized the shape and nature of the particles. Standardized and polished blocks of poly(methylmethacrylate) were brushed with a commercial electric toothbrush with the dentifrices. VSI quantified the mean roughness (Ra) and illustrated in 3D the abraded areas. Results Toothpastes induced a limited abrasion. Toothpowders induced a significantly higher roughness linked to the size of the abrasive particles. One powder (Gencix® produced a high abrasion when used with a standard testing weight. However, the powder is based on pumice particles covered by a plant homogenate that readily dissolves in water. When used in the same volume, or after dispersion in water, Ra was markedly reduced. Conclusion Light and electron microscopy characterize the abrasive particles and VSI is a new tool allowing the analysis of large surface of abraded materials. PMID:24212995

  9. Abrasion of 6 dentifrices measured by vertical scanning interference microscopy.

    Science.gov (United States)

    Pascaretti-Grizon, Florence; Mabilleau, Guillaume; Chappard, Daniel

    2013-01-01

    The abrasion of dentifrices is well recognized to eliminate the dental plaque. The aims of this study were to characterize the abrasive powders of 6 dentifrices (3 toothpastes and 3 toothpowders) and to measure the abrasion on a test surface by Vertical Scanning Interference microscopy (VSI). Bright field and polarization microscopy were used to identify the abrasive particles on the crude dentifrices and after prolonged washes. Scanning electron microscopy and microanalysis characterized the shape and nature of the particles. Standardized and polished blocks of poly(methylmethacrylate) were brushed with a commercial electric toothbrush with the dentifrices. VSI quantified the mean roughness (Ra) and illustrated in 3D the abraded areas. Toothpastes induced a limited abrasion. Toothpowders induced a significantly higher roughness linked to the size of the abrasive particles. One powder (Gencix® produced a high abrasion when used with a standard testing weight. However, the powder is based on pumice particles covered by a plant homogenate that readily dissolves in water. When used in the same volume, or after dispersion in water, Ra was markedly reduced. Light and electron microscopy characterize the abrasive particles and VSI is a new tool allowing the analysis of large surface of abraded materials.

  10. Scanned probe microscopy for thin film superconductor development

    Energy Technology Data Exchange (ETDEWEB)

    Moreland, J. [National Institute of Standards and Technology, Boulder, CO (United States)

    1996-12-31

    Scanned probe microscopy is a general term encompassing the science of imaging based on piezoelectric driven probes for measuring local changes in nanoscale properties of materials and devices. Techniques like scanning tunneling microscopy, atomic force microscopy, and scanning potentiometry are becoming common tools in the production and development labs in the semiconductor industry. The author presents several examples of applications specific to the development of high temperature superconducting thin films and thin-film devices.

  11. Re-scan confocal microscopy (RCM) improves the resolution of confocal microscopy and increases the sensitivity

    Science.gov (United States)

    De Luca, Giulia; Breedijk, Ronald; Hoebe, Ron; Stallinga, Sjoerd; Manders, Erik

    2017-03-01

    Re-scan confocal microscopy (RCM) is a new super-resolution technique based on a standard confocal microscope extended with a re-scan unit in the detection path that projects the emitted light onto a sensitive camera. In this paper the fundamental properties of RCM, lateral resolution, axial resolution and signal-to-noise ratio, are characterized and compared with properties of standard confocal microscopy. The results show that the lateral resolution of RCM is ~170 nm compared to ~240 nm of confocal microscopy for 488 nm excitation and 1.49 NA. As the theory predicts, this improved lateral resolution is independent of the pinhole diameter. In standard confocal microscopy, the same lateral resolution can only be achieved with an almost closed pinhole and, consequently, with a major loss of signal. We show that the sectioning capabilities of the standard confocal microscope are preserved in RCM and that the axial resolution of RCM is slightly better (~15%) than the standard confocal microscope. Furthermore, the signal-to-noise ratio in RCM is a factor of 2 higher than in standard confocal microscopy, also due to the use of highly sensitive modern cameras. In case the pinhole of a confocal microscope is adjusted in such way that the lateral resolution is comparable to that of RCM, the signal-to-noise ratio in RCM is 4 times higher than standard confocal microscopy. Therefore, RCM offers a good alternative to standard confocal microscopy for higher lateral resolution with the main advantage of strongly improved sensitivity.

  12. Scanning transmission electron microscopy imaging and analysis

    CERN Document Server

    Pennycook, Stephen J

    2011-01-01

    Provides the first comprehensive treatment of the physics and applications of this mainstream technique for imaging and analysis at the atomic level Presents applications of STEM in condensed matter physics, materials science, catalysis, and nanoscience Suitable for graduate students learning microscopy, researchers wishing to utilize STEM, as well as for specialists in other areas of microscopy Edited and written by leading researchers and practitioners

  13. Light Sheet Fluorescence Microscopy: A Review

    OpenAIRE

    Santi, Peter A.

    2011-01-01

    Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with subcellular resolution. This method is well suited for imaging deep within transparent tissues or within whole organisms, and because tissues are exposed to only a thin plane of light, specimen photobleaching and phototoxicity are minimized compared to wide-field fluorescence, confocal, or multiphoton microscopy. LSFMs produce...

  14. Optimal lens design and use in laser-scanning microscopy.

    NARCIS (Netherlands)

    Negrean, A.; Mansvelder, H.D.

    2014-01-01

    In laser-scanning microscopy often an off-the-shelf achromatic doublet is used as a scan lens which can reduce the available diffraction-limited field-of-view (FOV) by a factor of 3 and introduce chromatic aberrations that are scan angle dependent. Here we present several simple lens designs of

  15. 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.

  16. Combined frequency modulated atomic force microscopy and scanning tunneling microscopy detection for multi-tip scanning probe microscopy applications

    Science.gov (United States)

    Morawski, Ireneusz; Spiegelberg, Richard; Korte, Stefan; Voigtländer, Bert

    2015-12-01

    A method which allows scanning tunneling microscopy (STM) tip biasing independent of the sample bias during frequency modulated atomic force microscopy (AFM) operation is presented. The AFM sensor is supplied by an electronic circuit combining both a frequency shift signal and a tunneling current signal by means of an inductive coupling. This solution enables a control of the tip potential independent of the sample potential. Individual tip biasing is specifically important in order to implement multi-tip STM/AFM applications. An extensional quartz sensor (needle sensor) with a conductive tip is applied to record simultaneously topography and conductivity of the sample. The high resonance frequency of the needle sensor (1 MHz) allows scanning of a large area of the surface being investigated in a reasonably short time. A recipe for the amplitude calibration which is based only on the frequency shift signal and does not require the tip being in contact is presented. Additionally, we show spectral measurements of the mechanical vibration noise of the scanning system used in the investigations.

  17. Confocal laser scanning microscopy in study of bone calcification

    Science.gov (United States)

    Nishikawa, Tetsunari; Kokubu, Mayu; Kato, Hirohito; Imai, Koichi; Tanaka, Akio

    2012-12-01

    Bone regeneration in mandible and maxillae after extraction of teeth or tumor resection and the use of rough surface implants in bone induction must be investigated to elucidate the mechanism of calcification. The calcified tissues are subjected to chemical decalcification or physical grinding to observe their microscopic features with light microscopy and transmission electron microscopy where the microscopic tissue morphology is significantly altered. We investigated the usefulness of confocal laser scanning microscopy (CLSM) for this purpose. After staggering the time of administration of calcein and alizarin red to experimental rats and dogs, rat alveolar bone and dog femur grafted with coral as scaffold or dental implants were observed with CLSM. In rat alveolar bone, the calcification of newly-formed bone and net-like canaliculi was observed at the mesial bone from the roots progressed at the rate of 15 μm/day. In dog femur grafted with coral, newly-formed bones along the space of coral were observed in an orderly manner. In dog femur with dental implants, after 8 weeks, newly-formed bone proceeded along the rough surface of the implants. CLSM produced high-magnification images of newly-formed bone and thin sections were not needed.

  18. Comparison between optical-resolution photoacoustic microscopy and confocal laser scanning microscopy for turbid sample imaging.

    Science.gov (United States)

    U-Thainual, Paweena; Kim, Do-Hyun

    2015-12-01

    Optical-resolution photoacoustic microscopy (ORPAM) in theory provides lateral resolution equivalent to the optical diffraction limit. Scattering media, such as biological turbid media, attenuates the optical signal and also alters the diffraction-limited spot size of the focused beam. The ORPAM signal is generated only from a small voxel in scattering media with dimensions equivalent to the laser spot size after passing through scattering layers and is detected by an acoustic transducer, which is not affected by optical scattering. Thus, both ORPAM and confocal laser scanning microscopy (CLSM) reject scattered light. A multimodal optical microscopy platform that includes ORPAM and CLSM was constructed, and the lateral resolution of both modes was measured using patterned thin metal film with and without a scattering barrier. The effect of scattering media on the lateral resolution was studied using different scattering coefficients and was compared to computational results based on Monte Carlo simulations. It was found that degradation of lateral resolution due to optical scattering was not significant for either ORPAM or CLSM. The depth discrimination capability of ORPAM and CLSM was measured using microfiber embedded in a light scattering phantom material. ORPAM images demonstrated higher contrast compared to CLSM images partly due to reduced acoustic signal scattering.

  19. White-light photoluminescence and photoactivation in cadmium sulfide embedded in mesoporous silicon dioxide templates studied by confocal laser scanning microscopy.

    Science.gov (United States)

    Pellicer, E; Rossinyol, E; Rosado, M; Guerrero, M; Domingo-Roca, R; Suriñach, S; Castell, O; Baró, M D; Roldán, M; Sort, J

    2013-10-01

    SBA-15 and SBA-16 silica templates have been infiltrated with CdS by means of nanocasting using a hybrid precursor. The morphology and structure of both the SiO2@CdS nanocomposites and the silica-free CdS replicas have been characterized. The three-dimensional nanocrystalline CdS networks embedded in SBA-15 and SBA-16 silica templates exhibit broad photoluminescence (PL) spectra over the entire visible range, together with enhanced PL intensity compared to silica-free CdS replicas. These effects result from the role silica plays in passivating the surface of the CdS mesostructures. Furthermore, photoactivation is eventually observed during continuous illumination because of both structural and chemical surface modifications. Owing to this combination of properties, these materials could be appealing for solid-state lighting, where ultra-bright near-white PL emission is indispensable. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Plant cell wall characterization using scanning probe microscopy techniques

    Science.gov (United States)

    Yarbrough, John M; Himmel, Michael E; Ding, Shi-You

    2009-01-01

    Lignocellulosic biomass is today considered a promising renewable resource for bioenergy production. A combined chemical and biological process is currently under consideration for the conversion of polysaccharides from plant cell wall materials, mainly cellulose and hemicelluloses, to simple sugars that can be fermented to biofuels. Native plant cellulose forms nanometer-scale microfibrils that are embedded in a polymeric network of hemicelluloses, pectins, and lignins; this explains, in part, the recalcitrance of biomass to deconstruction. The chemical and structural characteristics of these plant cell wall constituents remain largely unknown today. Scanning probe microscopy techniques, particularly atomic force microscopy and its application in characterizing plant cell wall structure, are reviewed here. We also further discuss future developments based on scanning probe microscopy techniques that combine linear and nonlinear optical techniques to characterize plant cell wall nanometer-scale structures, specifically apertureless near-field scanning optical microscopy and coherent anti-Stokes Raman scattering microscopy. PMID:19703302

  1. Plant cell wall characterization using scanning probe microscopy techniques

    Directory of Open Access Journals (Sweden)

    Himmel Michael E

    2009-08-01

    Full Text Available Abstract Lignocellulosic biomass is today considered a promising renewable resource for bioenergy production. A combined chemical and biological process is currently under consideration for the conversion of polysaccharides from plant cell wall materials, mainly cellulose and hemicelluloses, to simple sugars that can be fermented to biofuels. Native plant cellulose forms nanometer-scale microfibrils that are embedded in a polymeric network of hemicelluloses, pectins, and lignins; this explains, in part, the recalcitrance of biomass to deconstruction. The chemical and structural characteristics of these plant cell wall constituents remain largely unknown today. Scanning probe microscopy techniques, particularly atomic force microscopy and its application in characterizing plant cell wall structure, are reviewed here. We also further discuss future developments based on scanning probe microscopy techniques that combine linear and nonlinear optical techniques to characterize plant cell wall nanometer-scale structures, specifically apertureless near-field scanning optical microscopy and coherent anti-Stokes Raman scattering microscopy.

  2. Full information acquisition in scanning probe microscopy and spectroscopy

    Science.gov (United States)

    Jesse, Stephen; Belianinov, Alex; Kalinin, Sergei V.; Somnath, Suhas

    2017-04-04

    Apparatus and methods are described for scanning probe microscopy and spectroscopy based on acquisition of full probe response. The full probe response contains valuable information about the probe-sample interaction that is lost in traditional scanning probe microscopy and spectroscopy methods. The full probe response is analyzed post data acquisition using fast Fourier transform and adaptive filtering, as well as multivariate analysis. The full response data is further compressed to retain only statistically significant components before being permanently stored.

  3. Confocal light scattering and absorption spectroscopic microscopy

    Science.gov (United States)

    Qiu, Le; Vitkin, Edward; Salahuddin, Saira; Zaman, Munir M.; Andersson, Charlotte; Freedman, Steven D.; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.

    2008-04-01

    We have developed a novel optical method for observing submicron intracellular structures in living cells which is called confocal light absorption and scattering spectroscopic (CLASS) microscopy. It combines confocal microscopy, a well-established high-resolution microscopic technique, with light scattering spectroscopy (LSS). CLASS microscopy requires no exogenous labels and is capable of imaging and continuously monitoring individual viable cells, enabling the observation of cell and organelle functioning at scales on the order of 100 nm. In addition, it provides not only size information but also information about the biochemical and physical properties of the cell.

  4. Optomechatronics Design and Control for Confocal Laser Scanning Microscopy

    NARCIS (Netherlands)

    Yoo, H.W.

    2015-01-01

    Confocal laser scanning microscopy (CLSM) is considered as one of the major advancements in microscopy in the last century and is widely accepted as a 3D fluorescence imaging tool for biological studies. For the emerging biological questions CLSM requires fast imaging to detect rapid biological

  5. Towards Automated Nanomanipulation under Scanning Electron Microscopy

    Science.gov (United States)

    Ye, Xutao

    Robotic Nanomaterial Manipulation inside scanning electron microscopes (SEM) is useful for prototyping functional devices and characterizing one-dimensional nanomaterial's properties. Conventionally, manipulation of nanowires has been performed via teleoperation, which is time-consuming and highly skill-dependent. Manual manipulation also has the limitation of low success rates and poor reproducibility. This research focuses on a robotic system capable of automated pick-place of single nanowires. Through SEM visual detection and vision-based motion control, the system transferred individual silicon nanowires from their growth substrate to a microelectromechanical systems (MEMS) device that characterized the nanowires' electromechanical properties. The performances of the nanorobotic pick-up and placement procedures were quantified by experiments. The system demonstrated automated nanowire pick-up and placement with high reliability. A software system for a load-lock-compatible nanomanipulation system is also designed and developed in this research.

  6. Light sheet microscopy in cell biology.

    Science.gov (United States)

    Tomer, Raju; Khairy, Khaled; Keller, Philipp J

    2013-01-01

    Light sheet-based fluorescence microscopy (LSFM) is emerging as a powerful imaging technique for the life sciences. LSFM provides an exceptionally high imaging speed, high signal-to-noise ratio, low level of photo-bleaching, and good optical penetration depth. This unique combination of capabilities makes light sheet-based microscopes highly suitable for live imaging applications. Here, we provide an overview of light sheet-based microscopy assays for in vitro and in vivo imaging of biological samples, including cell extracts, soft gels, and large multicellular organisms. We furthermore describe computational tools for basic image processing and data inspection.

  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. 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.

  9. New Applications of Scanning Tunneling Microscopy

    Science.gov (United States)

    Smith, Douglas Philip Edward

    This dissertation describes the application of the scanning tunneling microscope (STM) technique to four new fields of study: thin organic films, phonon spectroscopy of bulk surfaces, the vibrational spectroscopy of molecules, and the tribological forces which occur between STM tip and sample. Images with atomic resolution were obtained with speeds approaching video rates. Two types of microscopes were used: one operated at room temperature in air, another at 4.2K in liquid helium. At room temperature, the STM was able to image molecules of cadmium arachidate deposited onto graphite by the Langmuir-Blodgett technique. The packing of molecules in the lipid bilayer was found to be partially ordered, with density of 1 molecule per 19.4 square angstroms. At liquid-helium temperature, inelastic electron processes were detected, and it was possible to determine within an area of a few square angstroms where the vibrational excitations occurred. On a bare graphite substrate, phonons of the sample and tip caused step increases in the tunneling conductivity at the phonon energies. Molecules of sorbic acid could be resolved when deposited onto graphite, and these molecules caused spatially localized peaks in conductivity at the energies of the bond vibrations. Although the STM is usually considered a non-contact instrument, under certain circumstances the tip and sample exerted strong forces on each other. With a tungsten tip and a graphite sample, friction and mechanical deformations on the atomic scale were observed.

  10. Open Source Scanning Probe Microscopy Control Software Package Gxsm

    Energy Technology Data Exchange (ETDEWEB)

    Zahl P.; Wagner, T.; Moller, R.; Klust, A.

    2009-08-10

    Gxsm is a full featured and modern scanning probe microscopy (SPM) software. It can be used for powerful multidimensional image/data processing, analysis, and visualization. Connected toan instrument, it is operating many different avors of SPM, e.g., scanning tunneling microscopy(STM) and atomic force microscopy (AFM) or in general two-dimensional multi channel data acquisition instruments. The Gxsm core can handle different data types, e.g., integer and oating point numbers. An easily extendable plug-in architecture provides many image analysis and manipulation functions. A digital signal processor (DSP) subsystem runs the feedback loop, generates the scanning signals and acquires the data during SPM measurements. The programmable Gxsm vector probe engine performs virtually any thinkable spectroscopy and manipulation task, such as scanning tunneling spectroscopy (STS) or tip formation. The Gxsm software is released under the GNU general public license (GPL) and can be obtained via the Internet.

  11. Vector sensor for scanning SQUID microscopy

    Science.gov (United States)

    Dang, Vu The; Toji, Masaki; Thanh Huy, Ho; Miyajima, Shigeyuki; Shishido, Hiroaki; Hidaka, Mutsuo; Hayashi, Masahiko; Ishida, Takekazu

    2017-07-01

    We plan to build a novel 3-dimensional (3D) scanning SQUID microscope with high sensitivity and high spatial resolution. In the system, a vector sensor consists of three SQUID sensors and three pick-up coils realized on a single chip. Three pick-up coils are configured in orthogonal with each other to measure the magnetic field vector of X, Y, Z components. We fabricated some SQUID chips with one uniaxial pick-up coil or three vector pick-up coils and carried out fundamental measurements to reveal the basic characteristics. Josephson junctions (JJs) of sensors are designed to have the critical current density J c of 320 A/cm2, and the critical current I c becomes 12.5 μA for the 2.2μm × 2.2μm JJ. We carefully positioned the three pickup coils so as to keep them at the same height at the centers of all three X, Y and Z coils. This can be done by arranging them along single line parallel to a sample surface. With the aid of multilayer technology of Nb-based fabrication, we attempted to reduce an inner diameter of the pickup coils to enhance both sensitivity and spatial resolution. The method for improving a spatial resolution of a local magnetic field image is to employ an XYZ piezo-driven scanner for controlling the positions of the pick-up coils. The fundamental characteristics of our SQUID sensors confirmed the proper operation of our SQUID sensors and found a good agreement with our design parameters.

  12. Confocal laser scanning microscopy in study of bone calcification

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, Tetsunari, E-mail: tetsu-n@cc.osaka-dent.ac.jp [Department of Oral Pathology, Osaka Dental University, Osaka (Japan); Kokubu, Mayu; Kato, Hirohito [Department of Oral Pathology, Osaka Dental University, Osaka (Japan); Imai, Koichi [Department of Biomaterials, Osaka Dental University, Osaka (Japan); Tanaka, Akio [Department of Oral Pathology, Osaka Dental University, Osaka (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer High-magnification images with depth selection, and thin sections were observed using CLSM. Black-Right-Pointing-Pointer The direction and velocity of calcification of the bone was observed by administration of 2 fluorescent dyes. Black-Right-Pointing-Pointer In dog femora grafted with coral blocks, newly-formed bone was observed in the coral block space with a rough surface. Black-Right-Pointing-Pointer Twelve weeks after dental implant was grafted in dog femora, the space between screws was filled with newly-formed bones. - Abstract: Bone regeneration in mandible and maxillae after extraction of teeth or tumor resection and the use of rough surface implants in bone induction must be investigated to elucidate the mechanism of calcification. The calcified tissues are subjected to chemical decalcification or physical grinding to observe their microscopic features with light microscopy and transmission electron microscopy where the microscopic tissue morphology is significantly altered. We investigated the usefulness of confocal laser scanning microscopy (CLSM) for this purpose. After staggering the time of administration of calcein and alizarin red to experimental rats and dogs, rat alveolar bone and dog femur grafted with coral as scaffold or dental implants were observed with CLSM. In rat alveolar bone, the calcification of newly-formed bone and net-like canaliculi was observed at the mesial bone from the roots progressed at the rate of 15 {mu}m/day. In dog femur grafted with coral, newly-formed bones along the space of coral were observed in an orderly manner. In dog femur with dental implants, after 8 weeks, newly-formed bone proceeded along the rough surface of the implants. CLSM produced high-magnification images of newly-formed bone and thin sections were not needed.

  13. Reflection across plant cell boundaries in confocal laser scanning microscopy.

    Science.gov (United States)

    Liu, D Y T; Kuhlmey, B T; Smith, P M C; Day, D A; Faulkner, C R; Overall, R L

    2008-08-01

    The fluorescence patterns of proteins tagged with the green fluorescent protein (GFP) and its derivatives are routinely used in conjunction with confocal laser scanning microscopy to identify their sub-cellular localization in plant cells. GFP-tagged proteins localized to plasmodesmata, the intercellular junctions of plants, are often identified by single or paired punctate labelling across the cell wall. The observation of paired puncta, or 'doublets', across cell boundaries in tissues that have been transformed through biolistic bombardment is unexpected if there is no intercellular movement of the GFP-tagged protein, since bombardment usually leads to the transformation of single, isolated cells. We expressed a putative plasmodesmal protein tagged with GFP by bombarding Allium porrum epidermal cells and assessed the nature of the doublets observed at the cell boundaries. Doublets were formed when fluorescent spots were abutting a cell boundary and were only observable at certain focal planes. Fluorescence emitted from the half of a doublet lying outside the transformed cells was polarized. Optical simulations performed using finite-difference time-domain computations showed a dramatic distortion of the confocal microscope's point spread function when imaging voxels close to the plant cell wall due to refractive index differences between the wall and the cytosol. Consequently, axially and radially out-of-focus light could be detected. A model of this phenomenon suggests how a doublet may form when imaging only a single real fluorescent body in the vicinity of a plant cell wall using confocal microscopy. We suggest, therefore, that the appearance of doublets across cell boundaries is insufficient evidence for plasmodesmal localization due to the effects of the cell wall on the reflection and scattering of light.

  14. Scanning near-field infrared microscopy on semiconductor structures

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Rainer

    2011-01-15

    literature. While the structures of the first system were in the micrometer regime, the capability to probe buried nanostructures is demonstrated at a sample of indium arsenide quantum dots. Those dots are covered by a thick layer of gallium arsenide. For the first time ever, it is shown experimentally that transitions between electron states in single quantum dots can be investigated by near-field microscopy. By monitoring the near-field response of these quantum dots while scanning the wavelength of the incident light beam, it was possible to obtain characteristic near-field signatures of single dots. Near-field contrasts up to 30 % could be measured for resonant excitation of electrons in the conduction band of the indium arsenide dots. (orig.)

  15. Post-processing strategies in image scanning microscopy.

    Science.gov (United States)

    McGregor, J E; Mitchell, C A; Hartell, N A

    2015-10-15

    Image scanning microscopy (ISM) coupled with pixel reassignment offers a resolution improvement of √2 over standard widefield imaging. By scanning point-wise across the specimen and capturing an image of the fluorescent signal generated at each scan position, additional information about specimen structure is recorded and the highest accessible spatial frequency is doubled. Pixel reassignment can be achieved optically in real time or computationally a posteriori and is frequently combined with the use of a physical or digital pinhole to reject out of focus light. Here, we simulate an ISM dataset using a test image and apply standard and non-standard processing methods to address problems typically encountered in computational pixel reassignment and pinholing. We demonstrate that the predicted improvement in resolution is achieved by applying standard pixel reassignment to a simulated dataset and explore the effect of realistic displacements between the reference and true excitation positions. By identifying the position of the detected fluorescence maximum using localisation software and centring the digital pinhole on this co-ordinate before scaling around translated excitation positions, we can recover signal that would otherwise be degraded by the use of a pinhole aligned to an inaccurate excitation reference. This strategy is demonstrated using experimental data from a multiphoton ISM instrument. Finally we investigate the effect that imaging through tissue has on the positions of excitation foci at depth and observe a global scaling with respect to the applied reference grid. Using simulated and experimental data we explore the impact of a globally scaled reference on the ISM image and, by pinholing around the detected maxima, recover the signal across the whole field of view. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Condenser-free contrast methods for transmitted-light microscopy.

    Science.gov (United States)

    Webb, K F

    2015-01-01

    Phase contrast microscopy allows the study of highly transparent yet detail-rich specimens by producing intensity contrast from phase objects within the sample. Presented here is a generalized phase contrast illumination schema in which condenser optics are entirely abrogated, yielding a condenser-free yet highly effective method of obtaining phase contrast in transmitted-light microscopy. A ring of light emitting diodes (LEDs) is positioned within the light-path such that observation of the objective back focal plane places the illuminating ring in appropriate conjunction with the phase ring. It is demonstrated that true Zernike phase contrast is obtained, whose geometry can be flexibly manipulated to provide an arbitrary working distance between illuminator and sample. Condenser-free phase contrast is demonstrated across a range of magnifications (4-100×), numerical apertures (0.13-1.65NA) and conventional phase positions. Also demonstrated is condenser-free darkfield microscopy as well as combinatorial contrast including Rheinberg illumination and simultaneous, colour-contrasted, brightfield, darkfield and Zernike phase contrast. By providing enhanced and arbitrary working space above the preparation, a range of concurrent imaging and electrophysiological techniques will be technically facilitated. Condenser-free phase contrast is demonstrated in conjunction with scanning ion conductance microscopy (SICM), using a notched ring to admit the scanned probe. The compact, versatile LED illumination schema will further lend itself to novel next-generation transmitted-light microscopy designs. The condenser-free illumination method, using rings of independent or radially-scanned emitters, may be exploited in future in other electromagnetic wavebands, including X-rays or the infrared. © 2014 The Author. Journal of Microscopy published by John Wiley & Sons, Ltd on behalf of the Royal Microscopical Society.

  17. Nanostructural analysis by atomic force microscopy followed by light microscopy on the same archival slide.

    Science.gov (United States)

    Wagner, Mathias; Kaehler, Dirk; Anhenn, Olaf; Betz, Thomas; Awad, Sally; Shamaa, Ali; Theegarten, Dirk; Linder, Roland

    2009-07-01

    Integrated information on ultrastructural surface texture and chemistry increasingly plays a role in the biomedical sciences. Light microscopy provides access to biochemical data by the application of dyes. Ultrastructural representation of the surface structure of tissues, cells, or macromolecules can be obtained by scanning electron microscopy (SEM). However, SEM often requires gold or coal coating of biological samples, which makes a combined examination by light microscopy and SEM difficult. Conventional histochemical staining methods are not easily applicable to biological material subsequent to such treatment. Atomic force microscopy (AFM) gives access to surface textures down to ultrastructural dimensions without previous coating of the sample. A combination of AFM with conventional histochemical staining protocols for light microscopy on a single slide is therefore presented. Unstained cores were examined using AFM (tapping mode) and subsequently stained histochemically. The images obtained by AFM were compared with the results of histochemistry. AFM technology did not interfere with any of the histochemical staining protocols. Ultrastructurally analyzed regions could be identified in light microscopy and histochemical properties of ultrastructurally determined regions could be seen. AFM-generated ultrastructural information with subsequent staining gives way to novel findings in the biomedical sciences. (c) 2009 Wiley-Liss, Inc.

  18. Directional light scanning 3-D display

    Science.gov (United States)

    Aoki, Yoji; Horimai, Hideyoshi; Lim, Pang Boey; Watanabe, Kenjiro; Inoue, Mitsuteru

    2009-11-01

    This paper presents a new Three-Dimensional display method, so called Directional Light Scanning 3D display. By using holographic screen as a beam scanner and high frame rate Spatial Light Modulator (SLM), this method requires only one SLM but can display high resolution 3D images, solving the usual problem of lack of resolution.

  19. IR microscopy utilizing intense supercontinuum light source

    DEFF Research Database (Denmark)

    Dupont, Sune; Petersen, Christian; Thøgersen, Jan

    2012-01-01

    . The supercontinuum light source has a high brightness and spans the infrared region from 1400 nm to 4000 nm. This combination allows contact free high resolution hyper spectral infrared microscopy. The microscope is demonstrated by imaging an oil/water sample with 20 μm resolution.......Combining the molecular specificity of the infrared spectral region with high resolution microscopy has been pursued by researchers for decades. Here we demonstrate infrared supercontinuum radiated from an optical fiber as a promising new light source for infrared microspectroscopy...

  20. Light sheet fluorescence microscopy: a review.

    Science.gov (United States)

    Santi, Peter A

    2011-02-01

    Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with subcellular resolution. This method is well suited for imaging deep within transparent tissues or within whole organisms, and because tissues are exposed to only a thin plane of light, specimen photobleaching and phototoxicity are minimized compared to wide-field fluorescence, confocal, or multiphoton microscopy. LSFMs produce well-registered serial sections that are suitable for three-dimensional reconstruction of tissue structures. Because of a lack of a commercial LSFM microscope, numerous versions of light sheet microscopes have been constructed by different investigators. This review describes development of the technology, reviews existing devices, provides details of one LSFM device, and shows examples of images and three-dimensional reconstructions of tissues that were produced by LSFM.

  1. 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...... information is achieved when the results of OIM and these various techniques are combined. Examples hereof are given to illustrate the potentials of OIM techniques. Finally, limitations of TEM and SEM based OIM for specific applications are discussed....

  2. System and method for compressive scanning electron microscopy

    Science.gov (United States)

    Reed, Bryan W

    2015-01-13

    A scanning transmission electron microscopy (STEM) system is disclosed. The system may make use of an electron beam scanning system configured to generate a plurality of electron beam scans over substantially an entire sample, with each scan varying in electron-illumination intensity over a course of the scan. A signal acquisition system may be used for obtaining at least one of an image, a diffraction pattern, or a spectrum from the scans, the image, diffraction pattern, or spectrum representing only information from at least one of a select subplurality or linear combination of all pixel locations comprising the image. A dataset may be produced from the information. A subsystem may be used for mathematically analyzing the dataset to predict actual information that would have been produced by each pixel location of the image.

  3. Correlative light- and electron microscopy with chemical tags.

    Science.gov (United States)

    Perkovic, Mario; Kunz, Michael; Endesfelder, Ulrike; Bunse, Stefanie; Wigge, Christoph; Yu, Zhou; Hodirnau, Victor-Valentin; Scheffer, Margot P; Seybert, Anja; Malkusch, Sebastian; Schuman, Erin M; Heilemann, Mike; Frangakis, Achilleas S

    2014-05-01

    Correlative microscopy incorporates the specificity of fluorescent protein labeling into high-resolution electron micrographs. Several approaches exist for correlative microscopy, most of which have used the green fluorescent protein (GFP) as the label for light microscopy. Here we use chemical tagging and synthetic fluorophores instead, in order to achieve protein-specific labeling, and to perform multicolor imaging. We show that synthetic fluorophores preserve their post-embedding fluorescence in the presence of uranyl acetate. Post-embedding fluorescence is of such quality that the specimen can be prepared with identical protocols for scanning electron microscopy (SEM) and transmission electron microscopy (TEM); this is particularly valuable when singular or otherwise difficult samples are examined. We show that synthetic fluorophores give bright, well-resolved signals in super-resolution light microscopy, enabling us to superimpose light microscopic images with a precision of up to 25 nm in the x-y plane on electron micrographs. To exemplify the preservation quality of our new method we visualize the molecular arrangement of cadherins in adherens junctions of mouse epithelial cells. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Light Microscopy Module (LMM)-Emulator

    Science.gov (United States)

    Levine, Howard G.; Smith, Trent M.; Richards, Stephanie E.

    2016-01-01

    The Light Microscopy Module (LMM) is a microscope facility developed at Glenn Research Center (GRC) that provides researchers with powerful imaging capability onboard the International Space Station (ISS). LMM has the ability to have its hardware recongured on-orbit to accommodate a wide variety of investigations, with the capability of remotely acquiring and downloading digital images across multiple levels of magnication.

  5. Structural examination of lithium niobate ferroelectric crystals by combining scanning electron microscopy and atomic force microscopy

    Science.gov (United States)

    Efremova, P. V.; Ped'ko, B. B.; Kuznecova, Yu. V.

    2016-02-01

    The structure of lithium niobate single crystals is studied by a complex technique that combines scanning electron microscopy and atomic force microscopy. By implementing the piezoresponse force method on an atomic force microscope, the domain structure of lithium niobate crystals, which was not revealed without electron beam irradiation, is visualized

  6. Polarization contrast in photon scanning tunnelling microscopy combined with atomic force microscopy

    NARCIS (Netherlands)

    Propstra, K.; Propstra, K.; van Hulst, N.F.

    1995-01-01

    Photon scanning tunnelling microscopy combined with atomic force microscopy allows simultaneous acquisition and direct comparison of optical and topographical images, both with a lateral resolution of about 30 nm, far beyond the optical diffraction limit. The probe consists of a modified

  7. Investigation of whispering gallery modes in microlasers by scanning near-field optical microscopy

    Science.gov (United States)

    Polubavkina, Yu S.; Kryzhanovskaya, N. V.; Nadtochiy, A. M.; Mintairov, A. M.; Lipovsky, A. A.; Scherbak, S. A.; Kulagina, M. M.; Maximov, M. V.; Zhukov, A. E.

    2017-11-01

    Near-field scanning optical microscopy (NSOM) with a spatial resolution below the light diffraction limit was used to study intensity distributions of the whispering gallery modes (WGMs) in quantum dot-based microdisk and microring lasers on GaAs with different outer diameters. Room temperature microphotoluminescence study (μPL) reveal lasing in microlasers of both geometries.

  8. Scanning electron microscopy-energy dispersive X-ray spectrometer ...

    African Journals Online (AJOL)

    The distribution of arsenic (As) and cadmium (Cd) in himematsutake was analyzed using scanning electron microscopy-energy dispersive X-ray spectrometer (SEM-EDX). The atomic percentage of the metals was confirmed by inductively coupled plasma-mass spectrometer (ICP-MS). Results show that the accumulation of ...

  9. Challenges of scanning hall microscopy using batch fabricated probes

    NARCIS (Netherlands)

    Hatakeyama, Kodai

    2016-01-01

    Scanning Hall probe microscopy is a widely used technique for quantitative high resolution imaging of magnetic stray fields. Up to now probes with nanometer spatial resolution have only been realized by electron beam lithography, which is a slow and expensive fabrication technique. In this thesis,

  10. Nanochannel alignment analysis by scanning transmission ion microscopy

    DEFF Research Database (Denmark)

    Rajta, I.; Gál, G.A.B.; Szilasi, S.Z.

    2010-01-01

    In this paper a study on the ion transmission ratio of a nanoporous alumina sample is presented. The sample was investigated by scanning transmission ion microscopy (STIM) with different beam sizes. The hexagonally close-packed AlO nanocapillary array, realized as a suspended membrane of 15 νm...

  11. Scanning electron microscopy of Dermatobia hominis reveals cutaneous anchoring features.

    Science.gov (United States)

    Möhrenschlager, Matthias; Mempel, Martin; Weichenmeier, Ingrid; Engst, Reinhard; Ring, Johannnes; Behrendt, Heidrun

    2007-10-01

    We report the case of a 45-year-old Caucasian woman suffering from cutaneous myiasis. With the use of scanning electron microscopy, we placed special focus on the mechanisms by which Dermatobia hominis can fasten securely within the human skin.

  12. Ultrafast terahertz scanning tunneling microscopy with atomic resolution

    DEFF Research Database (Denmark)

    Jelic, Vedran; Iwaszczuk, Krzysztof; Nguyen, Peter H.

    2016-01-01

    We demonstrate that ultrafast terahertz scanning tunneling microscopy (THz-STM) can probe single atoms on a silicon surface with simultaneous sub-nanometer and sub-picosecond spatio-temporal resolution. THz-STM is established as a new technique for exploring high-field non-equilibrium tunneling...

  13. Characterization of Polycaprolactone Films Biodeterioration by Scanning Electron Microscopy

    Czech Academy of Sciences Publication Activity Database

    Hrubanová, Kamila; Voberková, S.; Hermanová, S.; Krzyžánek, Vladislav

    2014-01-01

    Roč. 20, S3 (2014), s. 1950-1951 ISSN 1431-9276 R&D Projects: GA MŠk EE.2.3.20.0103; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : polycaprolactone films * biodeterioration * scanning electron microscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.877, year: 2014

  14. Localization of fluorescently labeled structures in frozen-hydrated samples using integrated light electron microscopy

    NARCIS (Netherlands)

    Faas, F.G.A.; Bárcena, M.A.; Agronskaia, A.V.; Gerritsen, H.C.; Moscicka, K.B.; Diebolder, C.A.; Driel, L.F.; Limpens, R.W.A.L.; Bos, E.; Ravelli, R.B.G.; Koning, R.I.; Koster, A.J.

    2013-01-01

    Correlative light and electron microscopy is an increasingly popular technique to study complex biological systems at various levels of resolution. Fluorescence microscopy can be employed to scan large areas to localize regions of interest which are then analyzed by electron microscopy to obtain

  15. Scanning tunneling microscopy III theory of STM and related scanning probe methods

    CERN Document Server

    Güntherodt, Hans-Joachim

    1996-01-01

    Scanning Tunneling Microscopy III provides a unique introduction to the theoretical foundations of scanning tunneling microscopy and related scanning probe methods. The different theoretical concepts developed in the past are outlined, and the implications of the theoretical results for the interpretation of experimental data are discussed in detail. Therefore, this book serves as a most useful guide for experimentalists as well as for theoreticians working in the filed of local probe methods. In this second edition the text has been updated and new methods are discussed.

  16. Cryo scanning electron microscopy of Plasmodium falciparum-infected erythrocytes.

    Science.gov (United States)

    Hempel, Casper

    2017-07-01

    Plasmodium falciparum invades erythrocytes as an essential part of their life cycle. While living inside erythrocytes, the parasite remodels the cell's intracellular organization as well as its outer surface. Late trophozoite-stage parasites and schizonts introduce numerous small protrusions on the erythrocyte surface, called knobs. Current methods for studying these knobs include atomic force microscopy and electron microscopy. Standard electron microscopy methods rely on chemical fixation and dehydration modifying cell size. Here, a novel method is presented using rapid freezing and scanning electron microscopy under cryogenic conditions allowing for high resolution and magnification of erythrocytes. This novel technique can be used for precise estimates of knob density and for studies on cytoadhesion. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  17. Selectable light-sheet uniformity using tuned axial scanning.

    Science.gov (United States)

    Duocastella, Martí; Arnold, Craig B; Puchalla, Jason

    2017-02-01

    Light-sheet fluorescence microscopy (LSFM) is an optical sectioning technique capable of rapid three-dimensional (3D) imaging of a wide range of specimens with reduced phototoxicity and superior background rejection. However, traditional light-sheet generation approaches based on elliptical or circular Gaussian beams suffer an inherent trade-off between light-sheet thickness and area over which this thickness is preserved. Recently, an increase in light-sheet uniformity was demonstrated using rapid biaxial Gaussian beam scanning along the lateral and beam propagation directions. Here we apply a similar scanning concept to an elliptical beam generated by a cylindrical lens. In this case, only z-scanning of the elliptical beam is required and hence experimental implementation of the setup can be simplified. We introduce a simple dimensionless uniformity statistic to better characterize scanned light-sheets and experimentally demonstrate custom tailored uniformities up to a factor of 5 higher than those of unscanned elliptical beams. This technique offers a straightforward way to generate and characterize a custom illumination profile that provides enhanced utilization of the detector dynamic range and field of view, opening the door to faster and more efficient 2D and 3D imaging. © 2016 Wiley Periodicals, Inc.

  18. Non-linear image scanning microscopy (Conference Presentation)

    Science.gov (United States)

    Gregor, Ingo; Ros, Robert; Enderlein, Jörg

    2017-02-01

    Nowadays, multiphoton microscopy can be considered as a routine method for the observation of living cells, organs, up to whole organisms. Second-harmonics generation (SHG) imaging has evolved to a powerful qualitative and label-free method for studying fibrillar structures, like collagen networks. However, examples of super-resolution non-linear microscopy are rare. So far, such approaches require complex setups and advanced synchronization of scanning elements limiting the image acquisition rates. We describe theory and realization of a super-resolution image scanning microscope [1, 2] using two-photon excited fluorescence as well as second-harmonic generation. It requires only minor modifications compared to a classical two-photon laser-scanning microscope and allows image acquisition at the high frame rates of a resonant galvo-scanner. We achieve excellent sensitivity and high frame-rate in combination with two-times improved lateral resolution. We applied this method to fixed cells, collagen hydrogels, as well as living fly embryos. Further, we proofed the excellent image quality of our setup for deep tissue imaging. 1. Müller C.B. and Enderlein J. (2010) Image scanning microscopy. Phys. Rev. Lett. 104(19), 198101. 2. Sheppard C.J.R. (1988) Super-resolution in confocal imaging. Optik (Stuttg) 80 53-54.

  19. Scanning conductance microscopy investigations on fixed human chromosomes

    DEFF Research Database (Denmark)

    Clausen, Casper Hyttel; Lange, Jacob Moresco; Jensen, Linda Boye

    2008-01-01

    Scanning conductance microscopy investigations were carried out in air on human chromosomes fixed on pre-fabricated SiO2 surfaces with a backgate. The point of the investigation was to estimate the dielectric constant of fixed human chromosomes in order to use it for microfluidic device...... optimization. The phase shift caused by the electrostatic forces, together with geometrical measurements of the atomic force microscopy (AFM) cantilever and the chromosomes were used to estimate a value,for the dielectric constant of different human chromosomes....

  20. Resonant Scanning with Large Field of View Reduces Photobleaching and Enhances Fluorescence Yield in STED Microscopy.

    Science.gov (United States)

    Wu, Yong; Wu, Xundong; Lu, Rong; Zhang, Jin; Toro, Ligia; Stefani, Enrico

    2015-10-01

    Photobleaching is a major limitation of superresolution Stimulated Depletion Emission (STED) microscopy. Fast scanning has long been considered an effective means to reduce photobleaching in fluorescence microscopy, but a careful quantitative study of this issue is missing. In this paper, we show that the photobleaching rate in STED microscopy can be slowed down and the fluorescence yield be enhanced by scanning with high speed, enabled by using large field of view in a custom-built resonant-scanning STED microscope. The effect of scanning speed on photobleaching and fluorescence yield is more remarkable at higher levels of depletion laser irradiance, and virtually disappears in conventional confocal microscopy. With ≥6 GW∙cm(-2) depletion irradiance, we were able to extend the fluorophore survival time of Atto 647N and Abberior STAR 635P by ~80% with 8-fold wider field of view. We confirm that STED Photobleaching is primarily caused by the depletion light acting upon the excited fluorophores. Experimental data agree with a theoretical model. Our results encourage further increasing the linear scanning speed for photobleaching reduction in STED microscopy.

  1. Light and electron microscopy of classical Ehlers-Danlos syndrome.

    Science.gov (United States)

    de Almeida, Hiram L; Bicca, Eduardo; Rocha, Nara M; de Castro, Luis A S

    2013-02-01

    A 12-year-old boy with difficulty in wound healing and abnormal scars since early childhood was examined. Light microscopy showed loose and disperse dermal collagen with rare bundles, and fibroblasts show an irregular morphology. The fibrous sheath of hair presented a normal parallel distribution of the collagen fibers with normal spindle-shaped fibroblasts. Transmission electron microscopy also found disorganized collagen fibers, which were seen in a same field in longitudinal and cross sections. With high magnifications, an amorphous substance was seen near to loose collagen fibers, which showed variable diameters in cross sections. Scanning electron microscopy of the dermis showed disorganized collagen fibers and with higher magnification, important collagen disarrangement was observed with isolated and crossed-over fibers.

  2. Stochastic Micro-Pattern for Automated Correlative Fluorescence - Scanning Electron Microscopy

    Science.gov (United States)

    Begemann, Isabell; Viplav, Abhiyan; Rasch, Christiane; Galic, Milos

    2015-01-01

    Studies of cellular surface features gain from correlative approaches, where live cell information acquired by fluorescence light microscopy is complemented by ultrastructural information from scanning electron micrographs. Current approaches to spatially align fluorescence images with scanning electron micrographs are technically challenging and often cost or time-intensive. Relying exclusively on open-source software and equipment available in a standard lab, we have developed a method for rapid, software-assisted alignment of fluorescence images with the corresponding scanning electron micrographs via a stochastic gold micro-pattern. Here, we provide detailed instructions for micro-pattern production and image processing, troubleshooting for critical intermediate steps, and examples of membrane ultra-structures aligned with the fluorescence signal of proteins enriched at such sites. Together, the presented method for correlative fluorescence – scanning electron microscopy is versatile, robust and easily integrated into existing workflows, permitting image alignment with accuracy comparable to existing approaches with negligible investment of time or capital. PMID:26647824

  3. [Advances of in vivo confocal scanning laser microscopy].

    Science.gov (United States)

    Tian, Ke-bin; Zhou, Guo-yu

    2006-02-01

    In vivo confocal scanning laser microscopy is being widely established as a time-saving, non-invasive, investigative methods in the study of body surfaces. Skin can be observed in its native state in vivo without the fixing, sectioning and staining that is necessary for routine histology. It is a new technology that can provide detailed images of tissue architecture and cellular morphology of living tissue. This paper reviews the fundamentals of in vivo confocal imaging and its clinical applications.

  4. Sub-Kelvin scanning tunneling microscopy on magnetic molecules

    OpenAIRE

    Zhang, Lei

    2012-01-01

    Magnetic molecules have attracted lots interest. In this work, an ultra-stable and low noise scanning tunneling microscopy operating at 400 mK using He-3 (930 mK using He-4) has been developed. The magnetic behavior of different magnetic molecules on substrates, especially the exchange interaction between the magnetic ions, the magnetic anisotropy on the surface, the magnetic excitations as well as the Kondo effect, were studied by using STM.

  5. Scanning Electron Microscopy of Cristispira Species in Chesapeake Bay Oysters

    OpenAIRE

    Tall, Ben D.; Nauman, Robert K.

    1981-01-01

    Scanning electron microscopy was employed to observe the physical interactions between Cristispira spp. and the crystalline style of the Chesapeake Bay oyster (Crassostrea virginica Gmelin 1791). Cristispira organisms were found associated with both the inner and outer layers of the posterior two-thirds of the style. The spirochetes possessed blunt-tipped ends, a cell diameter range of 0.6 to 0.8 μm, and distended spirochetal envelopes which followed the contour of the cells. Transmission ele...

  6. Playing peekaboo with graphene oxide: a scanning electrochemical microscopy investigation.

    Science.gov (United States)

    Rapino, Stefania; Treossi, Emanuele; Palermo, Vincenzo; Marcaccio, Massimo; Paolucci, Francesco; Zerbetto, Francesco

    2014-11-07

    Scanning electrochemical microscopy (SECM) can image graphene oxide (GO) flakes on insulating and conducting substrates. The contrast between GO and the substrate is controlled by the electrostatic interactions that are established between the charges of the molecular redox mediator and the charges present in the sheet/substrate. SECM also allows quantitative measurement - at the nano/microscale - of the charge transfer kinetics between single monolayer sheets and agent molecules.

  7. Scanning gate microscopy of ultra clean carbon nanotube quantum dots

    OpenAIRE

    Xue, Jiamin; Dhall, Rohan; Cronin, Stephen B.; LeRoy, Brian J.

    2015-01-01

    We perform scanning gate microscopy on individual suspended carbon nanotube quantum dots. The size and position of the quantum dots can be visually identified from the concentric high conductance rings. For the ultra clean devices used in this study, two new effects are clearly identified. Electrostatic screening creates non-overlapping multiple sets of Coulomb rings from a single quantum dot. In double quantum dots, by changing the tip voltage, the interactions between the quantum dots can b...

  8. Analysis of leaf surfaces using scanning ion conductance microscopy.

    Science.gov (United States)

    Walker, Shaun C; Allen, Stephanie; Bell, Gordon; Roberts, Clive J

    2015-05-01

    Leaf surfaces are highly complex functional systems with well defined chemistry and structure dictating the barrier and transport properties of the leaf cuticle. It is a significant imaging challenge to analyse the very thin and often complex wax-like leaf cuticle morphology in their natural state. Scanning electron microscopy (SEM) and to a lesser extent Atomic force microscopy are techniques that have been used to study the leaf surface but their remains information that is difficult to obtain via these approaches. SEM is able to produce highly detailed and high-resolution images needed to study leaf structures at the submicron level. It typically operates in a vacuum or low pressure environment and as a consequence is generally unable to deal with the in situ analysis of dynamic surface events at submicron scales. Atomic force microscopy also possess the high-resolution imaging required and can follow dynamic events in ambient and liquid environments, but can over exaggerate small features and cannot image most leaf surfaces due to their inherent roughness at the micron scale. Scanning ion conductance microscopy (SICM), which operates in a liquid environment, provides a potential complementary analytical approach able to address these issues and which is yet to be explored for studying leaf surfaces. Here we illustrate the potential of SICM on various leaf surfaces and compare the data to SEM and atomic force microscopy images on the same samples. In achieving successful imaging we also show that SICM can be used to study the wetting of hydrophobic surfaces in situ. This has potentially wider implications than the study of leaves alone as surface wetting phenomena are important in a range of fundamental and applied studies. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  9. 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

  10. Artifact characterization and reduction in scanning X-ray Zernike phase contrast microscopy.

    Science.gov (United States)

    Vartiainen, Ismo; Holzner, Christian; Mohacsi, Istvan; Karvinen, Petri; Diaz, Ana; Pigino, Gaia; David, Christian

    2015-05-18

    Zernike phase contrast microscopy is a well-established method for imaging specimens with low absorption contrast. It has been successfully implemented in full-field microscopy using visible light and X-rays. In microscopy Cowley's reciprocity principle connects scanning and full-field imaging. Even though the reciprocity in Zernike phase contrast has been discussed by several authors over the past thirty years, only recently it was experimentally verified using scanning X-ray microscopy. In this paper, we investigate the image and contrast formation in scanning Zernike phase contrast microscopy with a particular and detailed focus on the origin of imaging artifacts that are typically associated with Zernike phase contrast. We demonstrate experimentally with X-rays the effect of the phase mask design on the contrast and halo artifacts and present an optimized design of the phase mask with respect to photon efficiency and artifact reduction. Similarly, due to the principle of reciprocity the observations and conclusions of this work have direct applicability to Zernike phase contrast in full-field microscopy as well.

  11. Fourier phase microscopy with white light.

    Science.gov (United States)

    Bhaduri, Basanta; Tangella, Krishnarao; Popescu, Gabriel

    2013-01-01

    Laser-based Fourier phase microscopy (FPM) works on the principle of decomposition of an image field in two spatial components that can be controllably shifted in phase with respect to each other. However, due to the coherent illumination, the contrast in phase images is degraded by speckles. In this paper we present FPM with spatially coherent white light (wFPM), which offers high spatial phase sensitivity due to the low temporal coherence and high temporal phase stability due to common path geometry. Further, by using a fast spatial light modulator (SLM) and a fast scientific-grade complementary metal oxide semiconductor (sCMOS) camera, we report imaging at a maximum rate of 12.5 quantitative phase frames per second with 5.5 mega pixels image size. We illustrate the utility of wFPM as a contrast enhancement as well as dynamic phase measurement method by imaging section of benign colonic glands and red blood cell membrane fluctuation.

  12. Microvascular quantification based on contour-scanning photoacoustic microscopy

    Science.gov (United States)

    Yeh, Chenghung; Soetikno, Brian; Hu, Song; Maslov, Konstantin I.; Wang, Lihong V.

    2014-09-01

    Accurate quantification of microvasculature remains of interest in fundamental pathophysiological studies and clinical trials. Current photoacoustic microscopy can noninvasively quantify properties of the microvasculature, including vessel density and diameter, with a high spatial resolution. However, the depth range of focus (i.e., focal zone) of optical-resolution photoacoustic microscopy (OR-PAM) is often insufficient to encompass the depth variations of features of interest-such as blood vessels-due to uneven tissue surfaces. Thus, time-consuming image acquisitions at multiple different focal planes are required to maintain the region of interest in the focal zone. We have developed continuous three-dimensional motorized contour-scanning OR-PAM, which enables real-time adjustment of the focal plane to track the vessels' profile. We have experimentally demonstrated that contour scanning improves the signal-to-noise ratio of conventional OR-PAM by as much as 41% and shortens the image acquisition time by 3.2 times. Moreover, contour-scanning OR-PAM more accurately quantifies vessel density and diameter, and has been applied to studying tumors with uneven surfaces.

  13. Integrated Confocal and Scanning Probe Microscopy for Biomedical Research

    Directory of Open Access Journals (Sweden)

    B.J. Haupt

    2006-01-01

    Full Text Available Atomic force microscopy (AFM continues to be developed, not only in design, but also in application. The new focus of using AFM is changing from pure material to biomedical studies. More frequently, it is being used in combination with other optical imaging methods, such as confocal laser scanning microscopy (CLSM and fluorescent imaging, to provide a more comprehensive understanding of biological systems. To date, AFM has been used increasingly as a precise micromanipulator, probing and altering the mechanobiological characteristics of living cells and tissues, in order to examine specific, receptor-ligand interactions, material properties, and cell behavior. In this review, we discuss the development of this new hybrid AFM, current research, and potential applications in diagnosis and the detection of disease.

  14. High Resolution Helium Ion Scanning Microscopy of the Rat Kidney

    Science.gov (United States)

    Rice, William L.; Van Hoek, Alfred N.; Păunescu, Teodor G.; Huynh, Chuong; Goetze, Bernhard; Singh, Bipin; Scipioni, Larry; Stern, Lewis A.; Brown, Dennis

    2013-01-01

    Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details and provide

  15. High resolution helium ion scanning microscopy of the rat kidney.

    Science.gov (United States)

    Rice, William L; Van Hoek, Alfred N; Păunescu, Teodor G; Huynh, Chuong; Goetze, Bernhard; Singh, Bipin; Scipioni, Larry; Stern, Lewis A; Brown, Dennis

    2013-01-01

    Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details and provide

  16. High resolution helium ion scanning microscopy of the rat kidney.

    Directory of Open Access Journals (Sweden)

    William L Rice

    Full Text Available Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details

  17. Virtual microscopy, data management and image analysis in Aperio ScanScope system.

    Directory of Open Access Journals (Sweden)

    Wojciech Staniszewski

    2010-05-01

    Full Text Available The histology and the pathology clinical practice undergo a digital revolution. Essential change in laboratory practice - from classical light microscopes, thousands of glass specimens waiting on plates to a virtual microscope and onscreen diagnosis is right now. Currently there are more than 30 different systems for the Virtual Microscopy available on the market. However none of them is so oriented for the practical matters as Aperio ScanScope system.

  18. High-resolution low-dose scanning transmission electron microscopy.

    Science.gov (United States)

    Buban, James P; Ramasse, Quentin; Gipson, Bryant; Browning, Nigel D; Stahlberg, Henning

    2010-01-01

    During the past two decades instrumentation in scanning transmission electron microscopy (STEM) has pushed toward higher intensity electron probes to increase the signal-to-noise ratio of recorded images. While this is suitable for robust specimens, biological specimens require a much reduced electron dose for high-resolution imaging. We describe here protocols for low-dose STEM image recording with a conventional field-emission gun STEM, while maintaining the high-resolution capability of the instrument. Our findings show that a combination of reduced pixel dwell time and reduced gun current can achieve radiation doses comparable to low-dose TEM.

  19. 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

    Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning...... 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...

  20. [Pulmonary hydatidosis. Comparison of cytology and scanning electron microscopy].

    Science.gov (United States)

    Lavaud, F; Nou, J M; Sadrin, R; de Montreynaud, J M; Adnet, J J

    1986-01-01

    The puncture of a hydatid cyst with a fine needle is not generally recommended as a procedure and may even be contra-indicated in the first instance. Sometimes, however, the cytologist will be surprised to discover some scolices in the aspirate when the radiology is misleading, or not suggestive, and the serology is negative. We report two cases where the diagnosis was made by the cytological examination of the aspirate. The cytological study of the liquids was compared with electron microscopy scanning, enabling the stages of development of the parasite in the tissue of the pulmonary parenchyma to be assessed.

  1. Advanced Scanning Electron Microscopy and X Ray Microanalysis

    Science.gov (United States)

    Krinsley, David

    This text is the third in a group that evolved from a short course taught annually at Lehigh University, Bethlehem, Pa., since 1972. Chapters on magnetic contrast a nd electron channeling, dropped from the second volume for reasons of space, are included here along with new topics such as image processing. The first seven chapters should be oT value to those geologists interested in scanning electron microscopy (SEM) and microanalysis. Chapters 8 and 9, concerned with specimen preparation for biological SEM a nd cryomicroscopy, make up about one third of the text.

  2. Transfer functions in collection scanning near-field optical microscopy

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Vohnsen, Brian; Bozhevolnaya, Elena A.

    1999-01-01

    are considered with respect to the relation between near-field optical images and the corresponding intensity distributions. Our conclusions are supported with numerical simulations and experimental results obtained by using a photon scanning tunneling microscope with an uncoated fiber tip.......It is generally accepted that, if in collection near-field optical microscopy the probe-sample coupling can be disregarded, a fiber probe can be considered as a detector of the near-field intensity whose size can be accounted for via an intensity transfer function. We show that, in general...

  3. High-speed Lissajous-scan atomic force microscopy: Scan pattern planning and control design issues

    Science.gov (United States)

    Bazaei, A.; Yong, Yuen K.; Moheimani, S. O. Reza

    2012-06-01

    Tracking of triangular or sawtooth waveforms is a major difficulty for achieving high-speed operation in many scanning applications such as scanning probe microscopy. Such non-smooth waveforms contain high order harmonics of the scan frequency that can excite mechanical resonant modes of the positioning system, limiting the scan range and bandwidth. Hence, fast raster scanning often leads to image distortion. This paper proposes analysis and design methodologies for a nonlinear and smooth closed curve, known as Lissajous pattern, which allows much faster operations compared to the ordinary scan patterns. A simple closed-form measure is formulated for the image resolution of the Lissajous pattern. This enables us to systematically determine the scan parameters. Using internal model controllers (IMC), this non-raster scan method is implemented on a commercial atomic force microscope driven by a low resonance frequency positioning stage. To reduce the tracking errors due to actuator nonlinearities, higher order harmonic oscillators are included in the IMC controllers. This results in significant improvement compared to the traditional IMC method. It is shown that the proposed IMC controller achieves much better tracking performances compared to integral controllers when the noise rejection performances is a concern.

  4. Nanometrology using a through-focus scanning optical microscopy method

    Science.gov (United States)

    Attota, Ravikiran; Silver, Richard

    2011-02-01

    We present an initial review of a novel through-focus scanning optical microscopy (TSOM pronounced as 'tee-som') imaging method that produces nanometer-dimensional measurement sensitivity using a conventional bright-field optical microscope. In the TSOM method a target is scanned through the focus of an optical microscope, acquiring conventional optical images at different focal positions. The TSOM images are constructed using the through-focus optical images. A TSOM image is unique under given experimental conditions and is sensitive to changes in the dimensions of a target in a distinct way. We use this characteristic for nanoscale-dimensional metrology. This technique can be used to identify the dimension which is changing between two nanosized targets and to determine the dimensions using a library-matching method. This methodology has potential utility for a wide range of target geometries and application areas, including nanometrology, nanomanufacturing, defect analysis, inspection, process control and biotechnology.

  5. Quantitative phase imaging with scanning holographic microscopy: an experimental assessment.

    Science.gov (United States)

    Indebetouw, Guy; Tada, Yoshitaka; Leacock, John

    2006-11-28

    This paper demonstrates experimentally how quantitative phase information can be obtained in scanning holographic microscopy. Scanning holography can operate in both coherent and incoherent modes, simultaneously if desired, with different detector geometries. A spatially integrating detector provides an incoherent hologram of the object's intensity distribution (absorption and/or fluorescence, for example), while a point detector in a conjugate plane of the pupil provides a coherent hologram of the object's complex amplitude, from which a quantitative measure of its phase distribution can be extracted. The possibility of capturing simultaneously holograms of three-dimensional specimens, leading to three-dimensional reconstructions with absorption contrast, reflectance contrast, fluorescence contrast, as was previously demonstrated, and quantitative phase contrast, as shown here for the first time, opens up new avenues for multimodal imaging in biological studies.

  6. Quantitative single-molecule imaging by confocal laser scanning microscopy.

    Science.gov (United States)

    Vukojevic, Vladana; Heidkamp, Marcus; Ming, Yu; Johansson, Björn; Terenius, Lars; Rigler, Rudolf

    2008-11-25

    A new approach to quantitative single-molecule imaging by confocal laser scanning microscopy (CLSM) is presented. It relies on fluorescence intensity distribution to analyze the molecular occurrence statistics captured by digital imaging and enables direct determination of the number of fluorescent molecules and their diffusion rates without resorting to temporal or spatial autocorrelation analyses. Digital images of fluorescent molecules were recorded by using fast scanning and avalanche photodiode detectors. In this way the signal-to-background ratio was significantly improved, enabling direct quantitative imaging by CLSM. The potential of the proposed approach is demonstrated by using standard solutions of fluorescent dyes, fluorescently labeled DNA molecules, quantum dots, and the Enhanced Green Fluorescent Protein in solution and in live cells. The method was verified by using fluorescence correlation spectroscopy. The relevance for biological applications, in particular, for live cell imaging, is discussed.

  7. Elimination of periodic damped artifacts in scanning probe microscopy images

    Science.gov (United States)

    Chen, Yuhang; Huang, Wenhao

    2010-04-01

    When scanning probe microscopy (SPM) is operated at high scan rates, stripe-like artifacts will appear frequently in the SPM images. The removal of the image artifacts is highly demanded because they will distort the results in precise measurements. In this work, a method based on Prony analysis has been introduced to erase such periodic damped artifacts. Results demonstrate that this method prevails against the conventional fast Fourier transformation (FFT) method. Clean eliminations of the image artifacts are obtained, with almost no sacrifice of the detailed surface information. Even for arbitrary rough surfaces, the image artifacts can also be reduced by more than one order of magnitude. However, small amounts of stripes may still remain in the images. In these cases, the Prony analysis combined with locally weighted smoothing will provide better image quality. The artifacts reduction can have a meaning in the SPM-based visualization of dynamic phenomena with a nanoscale resolution.

  8. Quantitative phase imaging with scanning holographic microscopy: an experimental assesment

    Directory of Open Access Journals (Sweden)

    Tada Yoshitaka

    2006-11-01

    Full Text Available Abstract This paper demonstrates experimentally how quantitative phase information can be obtained in scanning holographic microscopy. Scanning holography can operate in both coherent and incoherent modes, simultaneously if desired, with different detector geometries. A spatially integrating detector provides an incoherent hologram of the object's intensity distribution (absorption and/or fluorescence, for example, while a point detector in a conjugate plane of the pupil provides a coherent hologram of the object's complex amplitude, from which a quantitative measure of its phase distribution can be extracted. The possibility of capturing simultaneously holograms of three-dimensional specimens, leading to three-dimensional reconstructions with absorption contrast, reflectance contrast, fluorescence contrast, as was previously demonstrated, and quantitative phase contrast, as shown here for the first time, opens up new avenues for multimodal imaging in biological studies.

  9. Quantification of shrinkage microcracking in young mortar with fluorescence light microscopy and ESEM

    NARCIS (Netherlands)

    Bisschop, J.; Van Mier, J.C.M.

    1999-01-01

    In this paper a method is described to quantify shrinkage microcracking in young mortar by means of crack mapping. Visualisation of the microcracks is realised with two techniques: Fluorescence Light Microscopy (FLM) and Environmental Scanning Electron Microscopy (ESEM). The preliminary results

  10. CHROMATIN TEXTURE OF MELANOCYTIC NUCLEI - CORRELATION BETWEEN LIGHT AND ELECTRON-MICROSCOPY

    NARCIS (Netherlands)

    ABMAYR, W; STOLZ, W; KORHERR, S; WILD, W; SCHMOECKEL, C

    1987-01-01

    Cells of a benign pigmented mole and a malignant melanoma were used to compare electron microscopy (EM) and light microscopy (LM) with high-resolution TV-scanning and multivariate analysis methods. Special emphasis was placed on different kinds of chromatin texture features and their discriminating

  11. Imaging hyphal growth of Physisporinus vitreus in Norway spruce wood by means of confocal laser scanning microscopy (CLSM)

    OpenAIRE

    Schubert, Mark; Stührk, Chris; Fuhr, Matthias J.; Schwarze, Francis W.M.R.

    2017-01-01

    Light microscopy and electron microscopy are the most common methods for analyzing wood-decay fungi. However, the 3D visualization and quantification of the filamentous structure of fungi in wood is difficult to realize by means of these traditional techniques. In the present work, confocal laser scanning microscopy (CLSM) was further developed for the quantitative imaging of the 3D microscopic hyphal growth of Physisporinus vitreus, a versatile fungus for engineering value-added wood product...

  12. Simultaneous Scanning Ion Conductance Microscopy and Atomic Force Microscopy with Microchanneled Cantilevers.

    Science.gov (United States)

    Ossola, Dario; Dorwling-Carter, Livie; Dermutz, Harald; Behr, Pascal; Vörös, János; Zambelli, Tomaso

    2015-12-04

    We combined scanning ion conductance microscopy (SICM) and atomic force microscopy (AFM) into a single tool using AFM cantilevers with an embedded microchannel flowing into the nanosized aperture at the apex of the hollow pyramid. An electrode was positioned in the AFM fluidic circuit connected to a second electrode in the bath. We could thus simultaneously measure the ionic current and the cantilever bending (in optical beam deflection mode). First, we quantitatively compared the SICM and AFM contact points on the approach curves. Second, we estimated where the probe in SICM mode touches the sample during scanning on a calibration grid and applied the finding to image a network of neurites on a Petri dish. Finally, we assessed the feasibility of a double controller using both the ionic current and the deflection as input signals of the piezofeedback. The experimental data were rationalized in the framework of finite elements simulations.

  13. Humidity effects on scanning polarization force microscopy imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yue, E-mail: shenyue@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhou, Yuan, E-mail: zhouy@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Sun, Yanxia; Zhang, Lijuan [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Ying; Hu, Jun; Zhang, Yi [Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2017-08-01

    Highlights: • The humidity dramatically affects the contrast of scanning polarization force microscopy (SPFM) imaging on mica surface. • This influence roots in the sensitive dielectric constant of mica surface to the humidity change. • A strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM is proposed. - Abstract: Scanning polarization force microscopy (SPFM) is a useful surface characterization technique to visually characterize and distinguish nanomaterial with different local dielectric properties at nanometer scale. In this paper, taking the individual one-atom-thick graphene oxide (GO) and reduced graphene oxide (rGO) sheets on mica as examples, we described the influences of environmental humidity on SPFM imaging. We found that the apparent heights (AHs) or contrast of SPFM imaging was influenced significantly by relative humidity (RH) at a response time of a few seconds. And this influence rooted in the sensitive dielectric constant of mica surface to the RH change. While dielectric properties of GO and rGO sheets were almost immune to the humidity change. In addition, we gave the method to determine the critical humidity at which the contrast conversion happened under different conditions. And this is important to the contrast control and repeatable imaging of SPFM through RH adjusting. These findings suggest a strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM, which is critically important for further distinguishment, manipulation, electronic applications, etc.

  14. Two-color two-photon fluorescence laser scanning microscopy.

    Science.gov (United States)

    Quentmeier, S; Denicke, S; Gericke, K-H

    2009-11-01

    We present the first realization of a Two-Color Two-Photon Laser-Scanning Microscope (2c2pLSM) and UV fluorescence images of cells acquired with this technique. Fluorescence is induced by two-color two-photon absorption using the fundamental and the second harmonic of a Ti:Sa femtosecond laser. Simultaneous absorption of an 800 nm photon and a 400 nm photon energetically corresponds to one-photon absorption at 266 nm. This technique for Laser-Scanning Microscopy extends the excitation wavelength range of a Ti:Sa powered fluorescence microscope to the UV. In addition to the known advantages of multi-photon microscopy like intrinsic 3D resolution, reduced photo damage and high penetration depth 2c2pLSM offers the possibility of using standard high numeric aperture objectives for UV fluorescence imaging. The effective excitation wavelength of 266 nm corresponds especially well to the excitation spectrum of tryptophan. Hence, it is an ideal tool for label free fluorescence studies and imaging of intrinsic protein fluorescence which originates mainly from tryptophan. Thus a very sensitive natural lifetime probe can be used for monitoring protein reactions or changes in conformation. First measurements of living MIN-6 cells reveal differences between the UV fluorescence lifetimes of the nucleus and cytoplasm. The significance of this method was further demonstrated by monitoring the binding of biotin to avidin.

  15. Gold nanocone near-field scanning optical microscopy probes.

    Science.gov (United States)

    Fleischer, Monika; Weber-Bargioni, Alexander; Altoe, M Virginia P; Schwartzberg, Adam M; Schuck, P James; Cabrini, Stefano; Kern, Dieter P

    2011-04-26

    Near-field scanning optical microscopy enables the simultaneous topographical and subdiffraction limited optical imaging of surfaces. A process is presented for the implementation of single individually engineered gold cones at the tips of atomic force microscopy cantilevers. These cantilevers act as novel high-performance optical near-field probes. In the fabrication, thin-film metallization, electron beam induced deposition of etch masks, and Ar ion milling are combined. The cone constitutes a well-defined highly efficient optical antenna with a tip radius on the order of 10 nm and an adjustable plasmon resonance frequency. The sharp tip enables high resolution topographical imaging. By controllably varying the cone size, the resonance frequency can be adapted to the application of choice. Structural properties of these sharp-tipped probes are presented together with topographical images recorded with a cone probe. The antenna functionality is demonstrated by gathering the near-field enhanced Raman signature of individual carbon nanotubes with a gold cone scanning probe.

  16. Scanning ion microscopy with low energy lithium ions

    Energy Technology Data Exchange (ETDEWEB)

    Twedt, Kevin A. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Maryland NanoCenter, University of Maryland, College Park, MD 20742 (United States); Chen, Lei [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); McClelland, Jabez J., E-mail: jabez.mcclelland@nist.gov [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

    2014-07-01

    Using an ion source based on photoionization of laser-cooled lithium atoms, we have developed a scanning ion microscope with probe sizes of a few tens of nanometers and beam energies from 500 eV to 5 keV. These beam energies are much lower than the typical operating energies of the helium ion microscope or gallium focused ion beam systems. We demonstrate how low energy can be advantageous in ion microscopy when detecting backscattered ions, due to a decreased interaction volume and the potential for surface sensitive composition analysis. As an example application that demonstrates these advantages, we non-destructively image the removal of a thin residual resist layer during plasma etching in a nano-imprint lithography process. - Highlights: • We use an ion source based on photoionization of laser-cooled lithium atoms. • The ion source makes possible a low energy (500 eV to 5 keV) scanning ion microscope. • Low energy is preferred for ion microscopy with backscattered ions. • We use the microscope to image a thin resist used in nano-imprint lithography.

  17. Correlative light and electron microscopy : strategies and applications

    NARCIS (Netherlands)

    Driel, Linda Francina van

    2011-01-01

    Correlative light and electron microscopy (CLEM) refers to the observation of the same structures or ultrastructures with both light microscopy (LM) and electron microscopy (EM). LM provides an overview of the studied material, and enables the quick localization of structures that are fluorescently

  18. Immunolabeling for scanning electron microscopy (SEM) and field emission SEM.

    Science.gov (United States)

    Goldberg, Martin W

    2008-01-01

    Scanning electron microscopy (SEM) is a high resolution surface imaging technique. Many biological process and structures occur at surfaces and if antibodies are available, their components can be located within the surface structure. This is usually done in a similar way to immuno-fluorescence, using an unconjugated primary antibody followed by a tagged secondary antibody against the primary. In this case the tag is usually a colloidal gold particle instead of a fluorophore. Therefore it is quite straightforward to adapt an immuno-fluorescence procedure for SEM, as long as certain precautions are followed, as discussed here. Progressing from immuno-fluorescence, which essentially only indicates the position of a protein within the volume of a cell, to immuno-SEM, puts the labeling into the context of cellular structures. The principles and practices of sample preparation, labeling and imaging are described here.

  19. Ultramicrosensors based on transition metal hexacyanoferrates for scanning electrochemical microscopy

    Directory of Open Access Journals (Sweden)

    Maria A. Komkova

    2013-10-01

    Full Text Available We report here a way for improving the stability of ultramicroelectrodes (UME based on hexacyanoferrate-modified metals for the detection of hydrogen peroxide. The most stable sensors were obtained by electrochemical deposition of six layers of hexacyanoferrates (HCF, more specifically, an alternating pattern of three layers of Prussian Blue and three layers of Ni–HCF. The microelectrodes modified with mixed layers were continuously monitored in 1 mM hydrogen peroxide and proved to be stable for more than 5 h under these conditions. The mixed layer microelectrodes exhibited a stability which is five times as high as the stability of conventional Prussian Blue-modified UMEs. The sensitivity of the mixed layer sensor was 0.32 A·M−1·cm−2, and the detection limit was 10 µM. The mixed layer-based UMEs were used as sensors in scanning electrochemical microscopy (SECM experiments for imaging of hydrogen peroxide evolution.

  20. Confocal laser scanning microscopy-guided surgery for neurofibroma.

    Science.gov (United States)

    Koller, S; Horn, M; Weger, W; Massone, C; Smolle, J; Gerger, A

    2009-12-01

    The neurofibromatoses comprise at least two separate genetic disorders with variable clinical features and an unpredictable course. The most common type, neurofibromatosis 1, is characterized by > or = 6 café-au-lait spots and the occurrence of neurofibromas, which may present as cutaneous, subcutaneous or plexiform lesions. Normally, excision of neurofibromas is only indicated in the presence of neurological symptoms, suspicion of malignancy or for exceptional cosmetic reasons. For a good functional and aesthetic result with the least danger of recurrence, the surgeon's goal is to excise as much tissue as necessary and as little tissue as possible. One of the main issues during the surgical procedure is to distinguish between neurofibroma and surrounding tissue. We report for the first time the use of confocal laser scanning microscopy to differentiate between neurofibroma and healthy skin.

  1. Cryo-Scanning Electron Microscopy of Captured Cirrus Ice Particles

    Science.gov (United States)

    Magee, N. B.; Boaggio, K.; Bandamede, M.; Bancroft, L.; Hurler, K.

    2016-12-01

    We present the latest collection of high-resolution cryo-scanning electron microscopy images and microanalysis of cirrus ice particles captured by high-altitude balloon (ICE-Ball, see abstracts by K. Boaggio and M. Bandamede). Ice particle images and sublimation-residues are derived from particles captured during approximately 15 balloon flights conducted in Pennsylvania and New Jersey over the past 12 months. Measurements include 3D digital elevation model reconstructions of ice particles, and associated statistical analyses of entire particles and particle sub-facets and surfaces. This 3D analysis reveals that morphologies of most ice particles captured deviate significantly from ideal habits, and display geometric complexity and surface roughness at multiple measureable scales, ranging from 100's nanometers to 100's of microns. The presentation suggests potential a path forward for representing scattering from a realistically complex array of ice particle shapes and surfaces.

  2. Local deposition of anisotropic nanoparticles using scanning electrochemical microscopy (SECM).

    Science.gov (United States)

    Fedorov, Roman G; Mandler, Daniel

    2013-02-28

    We demonstrate localized electrodeposition of anisotropic metal nanoobjects, namely Au nanorods (GNR), on indium tin oxide (ITO) using scanning electrochemical microscopy (SECM). A gold microelectrode was the source of the gold ions whereby double pulse chronoamperometry was employed to generate initially Au seeds which were further grown under controlled conditions. The distance between the microelectrode and the ITO surface as well as the different experimental parameters (electrodeposition regime, solution composition and temperature) were optimized to produce faceted gold seeds with the required characteristics (size and distribution). Colloidal chemical synthesis was successfully exploited for better understanding the role of the surfactant and different additives in breaking the crystallographic symmetry and anisotropic growth of GNR. Experiments performed in a conventional three-electrode cell revealed the most appropriate electrochemical conditions allowing high yield synthesis of nanorods with well-defined shape as well as nanocubes and bipyramids.

  3. Preparation of platinum/iridium scanning probe microscopy tips

    DEFF Research Database (Denmark)

    Sørensen, Alexis Hammer; Hvid, U.; Mortensen, M.W.

    1999-01-01

    material being etched is platinum/iridium (10%) the influence of the stop phase of the ac current terminating each pulse in the second etching is found to be negligible, while in the case of second etching of tungsten wires it is important to break the pulse in a certain phase to avoid formation of a thick...... of platinum from the wire surface and hereby give rise to "etching" of the wire. In the second etching blunt tips become sharp while tips which are already sharp apparently stay sharp. Therefore, the second etching scheme with pulses separated by pauses is found to be a very important factor...... for the production of sharp tips. After being etched the tips are ready for use in scanning tunneling microscopes, or they may be bent to form integrated tip/cantilever systems in ordinary commercial atomic force microscopes, being applicable as tapping mode tips and as electrostatic force microscopy tips. ©1999...

  4. 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.

  5. Scanning Surface Potential Microscopy of Spore Adhesion on Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ida [University of Tennessee, Knoxville (UTK); Chung, Eunhyea [Georgia Institute of Technology; Kweon, Hyojin [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Tsouris, Costas [ORNL

    2012-01-01

    The adhesion of spores of Bacillus anthracis - the cause of anthrax and a likely biological threat - to solid surfaces is an important consideration in cleanup after an accidental or deliberate release. However, because of safety concerns, directly studying B. anthracis spores with advanced instrumentation is problematic. As a first step, we are examining the electrostatic potential of Bacillus thuringiensis (Bt), which is a closely related species that is often used as a simulant to study B. anthracis. Scanning surface potential microscopy (SSPM), also known as Kelvin probe force microscopy (KPFM), was used to investigate the influence of relative humidity (RH) on the surface electrostatic potential of Bt that had adhered to silica, mica, or gold substrates. AFM/SSPM side-by-side images were obtained separately in air, at various values of RH, after an aqueous droplet with spores was applied on each surface and allowed to dry before measurements. In the SSPM images, a negative potential on the surface of the spores was observed compared with that of the substrates. The surface potential decreased as the humidity increased. Spores were unable to adhere to a surface with an extremely negative potential, such as mica.

  6. 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).

  7. 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...

  8. Water-Immersible MEMS scanning mirror designed for wide-field fast-scanning photoacoustic microscopy

    Science.gov (United States)

    Yao, Junjie; Huang, Chih-Hsien; Martel, Catherine; Maslov, Konstantin I.; Wang, Lidai; Yang, Joon-Mo; Gao, Liang; Randolph, Gwendalyn; Zou, Jun; Wang, Lihong V.

    2013-03-01

    By offering images with high spatial resolution and unique optical absorption contrast, optical-resolution photoacoustic microscopy (OR-PAM) has gained increasing attention in biomedical research. Recent developments in OR-PAM have improved its imaging speed, but have sacrificed either the detection sensitivity or field of view or both. We have developed a wide-field fast-scanning OR-PAM by using a water-immersible MEMS scanning mirror (MEMS-ORPAM). Made of silicon with a gold coating, the MEMS mirror plate can reflect both optical and acoustic beams. Because it uses an electromagnetic driving force, the whole MEMS scanning system can be submerged in water. In MEMS-ORPAM, the optical and acoustic beams are confocally configured and simultaneously steered, which ensures uniform detection sensitivity. A B-scan imaging speed as high as 400 Hz can be achieved over a 3 mm scanning range. A diffraction-limited lateral resolution of 2.4 μm in water and a maximum imaging depth of 1.1 mm in soft tissue have been experimentally determined. Using the system, we imaged the flow dynamics of both red blood cells and carbon particles in a mouse ear in vivo. By using Evans blue dye as the contrast agent, we also imaged the flow dynamics of lymphatic vessels in a mouse tail in vivo. The results show that MEMS-OR-PAM could be a powerful tool for studying highly dynamic and time-sensitive biological phenomena.

  9. Polarized light microscopy in mammalian oocytes.

    Science.gov (United States)

    Caamaño, J N; Muñoz, M; Diez, C; Gómez, E

    2010-06-01

    The meiotic spindle structure plays a key role in normal chromosome alignment and segregation during meiosis. Polarized light microscopy (PLM) allows non-invasive evaluation of the meiotic spindle of metaphase oocytes from different animal species. The purpose of this article is to review the use of PLM in animal reproduction, mainly in the assessment of the meiotic spindle in oocytes. A brief overview of the methods to assess the meiotic spindle is presented as well as the principles behind the PLM. The use of PLM to evaluate oocyte quality and spindle morphology is discussed and the results on the viability of the oocytes after being exposed to PLM are presented. Several researchers showed that PLM could be successfully implemented on cryopreservation, nuclear transfer and intracytoplasmic sperm injection procedures as a tool to improve the outcome of these procedures. In addition, PLM can be used to develop studies on oocyte maturation and spindle dynamics. However, the information on the practical use of this technology in farm animals is very limited and further studies are needed to assess the importance of PLM in animal reproduction.

  10. Computer vision distortion correction of scanning probe microscopy images.

    Science.gov (United States)

    Gaponenko, Iaroslav; Tückmantel, Philippe; Ziegler, Benedikt; Rapin, Guillaume; Chhikara, Manisha; Paruch, Patrycja

    2017-04-06

    Since its inception, scanning probe microscopy (SPM) has established itself as the tool of choice for probing surfaces and functionalities at the nanoscale. Although recent developments in the instrumentation have greatly improved the metrological aspects of SPM, it is still plagued by the drifts and nonlinearities of the piezoelectric actuators underlying the precise nanoscale motion. In this work, we present an innovative computer-vision-based distortion correction algorithm for offline processing of functional SPM measurements, allowing two images to be directly overlaid with minimal error - thus correlating position with time evolution and local functionality. To demonstrate its versatility, the algorithm is applied to two very different systems. First, we show the tracking of polarisation switching in an epitaxial Pb(Zr0.2Ti0.8)O3 thin film during high-speed continuous scanning under applied tip bias. Thanks to the precise time-location-polarisation correlation we can extract the regions of domain nucleation and track the motion of domain walls until the merging of the latter in avalanche-like events. Secondly, the morphology of surface folds and wrinkles in graphene deposited on a PET substrate is probed as a function of applied strain, allowing the relaxation of individual wrinkles to be tracked.

  11. Scanning X-ray microscopy of superconductor/ferromagnet bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Claudia; Ruoss, Stephen; Weigand, Markus; Schuetz, Gisela [Max Planck Institute for Intelligent Systems, Stuttgart (Germany); Zahn, Patrick; Bayer, Jonas [Max Planck Institute for Intelligent Systems, Stuttgart (Germany); Research Institute for Innovative Surfaces, FINO, Aalen University (Germany); Albrecht, Joachim [Research Institute for Innovative Surfaces, FINO, Aalen University (Germany)

    2016-07-01

    The magnetic flux distribution arising from a high-T{sub c} superconductor is detected and visualized with high spatial resolution using scanning x-ray microscopy (SXM). Therefore, we introduce a sensor layer, namely, an amorphous, soft-magnetic CoFeB cover layer. The magnetic stray fields of the supercurrents lead to a local reorientation of the magnetic moments in the ferromagnet, which is visualized using the large x-ray magnetic circular dichroism (XMCD) effect of the Co and Fe L3-edge. We show that the XMCD contrast in the sensor layer corresponds to the in-plane magnetic flux distribution of the superconductor and can hence be used to image magnetic structures in superconductors with high spatial resolution. Using the total electron yield (TEY) mode the surface structure and the magnetic domains can be imaged simultaneously and can be correlated. The measurements are carried out at our scanning x-ray microscope MAXYMUS at Bessy II, Berlin with the new low temperature setup.

  12. Observation of photodynamically-induced cell destruction probed by video microscopy, laser-scanning microscopy, and fluorescence spectroscopy

    Science.gov (United States)

    Rueck, Angelika C.; Strauss, Wolfgang S. L.; Gschwend, Michael H.; Koenig, Karsten; Brunner, B.; Schneckenburger, Herbert; Walt, Heinrich; Steiner, Rudolf W.

    1993-07-01

    In order to study light-induced reactions during PDT, the fluorescence response of the photosensitizer meso-tetra(4-sulfonatophenyl)porphyrin (TPPS4) was observed in different cell systems and correlated with the sensitivity to photodynamic induced destructions. RR 1022 epithelial cells from the rat were grown on microscopic slides at a high and low cell density. Using video microscopy in combination with microspectrofluorometry we observed a different fluorescence behavior for high and low cell conditions during light exposure. A fluorescence relocalization from the cytoplasm to the nucleus and an intensity increase-- correlated with the formation of a new molecular species--could be detected only for low cell density. Moreover, cell cultures at a high density showed to be less sensitive to photodynamic destructions. In addition to cell culture-experiments, we observed the light-induced reactions of TPPS4 accumulated in multicellular tumor spheroids. For these measurements laser scanning microscopy was used. Fluorescence relocalization and intensity increase could be detected only for the peripheric parts of the spheroids. The different fluorescence response seems to reflect different metabolic and physiologic states of the cells.

  13. Metal particles in a ceramic matrix--scanning electron microscopy and transmission electron microscopy characterization.

    Science.gov (United States)

    Konopka, K

    2006-09-01

    This paper is concerned with ceramic matrix (Al(2)O(3)) composites with introduced metal particles (Ni, Fe). The composites were obtained via sintering of powders under very high pressure (2.5 GPa). Scanning electron microscopy and transmission electron microscopy were chosen as the tools for the identification and description of the shape, size and distribution of the metal particles. The Al(2)O(3)-Ni composite contained agglomerates of the Ni particles surrounded by ceramic grains and nanometre-size Ni particles located inside the ceramic grains and at the ceramic grain boundaries. In the Al(2)O(3)-Fe composite, the Fe particles were mostly surrounded by ceramic grains. Moreover, holes left by the Fe particles were found. The high pressure used in the fabrication of the composites changed the shape of the metal and ceramic powder grains via plastic deformation.

  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. Scanning probe microscopy investigation of complex-oxide heterostructures

    Science.gov (United States)

    Bi, Feng

    Advances in the growth of precisely tailored complex-oxide heterostructures have led to new emergent behavior and associated discoveries. One of the most successful examples consists of an ultrathin layer of LaAlO 3 (LAO) deposited on TiO2-terminated SrTiO3 (STO), where a high mobility quasi-two dimensional electron liquid (2DEL) is formed at the interface. Such 2DEL demonstrates a variety of novel properties, including field tunable metal-insulator transition, superconductivity, strong spin-orbit coupling, magnetic and ferroelectric like behavior. Particularly, for 3-unit-cell (3 u.c.) LAO/STO heterostructures, it was demonstrated that a conductive atomic force microscope (c-AFM) tip can be used to "write" or "erase" nanoscale conducting channels at the interface, making LAO/STO a highly flexible platform to fabricate novel nanoelectronics. This thesis is focused on scanning probe microscopy studies of LAO/STO properties. We investigate the mechanism of c-AFM lithography over 3 u.c. LAO/STO in controlled ambient conditions by using a vacuum AFM, and find that the water molecules dissociated on the LAO surface play a critical role during the c-AFM lithography process. We also perform electro-mechanical response measurements over top-gated LAO/STO devices. Simultaneous piezoresponse force microscopy (PFM) and capacitance measurements reveal a correlation between LAO lattice distortion and interfacial carrier density, which suggests that PFM could not only serve as a powerful tool to map the carrier density at the interface but also provide insight into previously reported frequency dependence of capacitance enhancement of top-gated LAO/STO structures. To study magnetism at the LAO/STO interface, magnetic force microscopy (MFM) and magnetoelectric force microscopy (MeFM) are carried out to search for magnetic signatures that depend on the carrier density at the interface. Results demonstrate an electronicallycontrolled ferromagnetic phase on top-gated LAO

  16. Low-cost cryo-light microscopy stage fabrication for correlated light/electron microscopy.

    Science.gov (United States)

    Carlson, David B; Evans, James E

    2011-06-05

    The coupling of cryo-light microscopy (cryo-LM) and cryo-electron microscopy (cryo-EM) poses a number of advantages for understanding cellular dynamics and ultrastructure. First, cells can be imaged in a near native environment for both techniques. Second, due to the vitrification process, samples are preserved by rapid physical immobilization rather than slow chemical fixation. Third, imaging the same sample with both cryo-LM and cryo-EM provides correlation of data from a single cell, rather than a comparison of "representative samples". While these benefits are well known from prior studies, the widespread use of correlative cryo-LM and cryo-EM remains limited due to the expense and complexity of buying or building a suitable cryogenic light microscopy stage. Here we demonstrate the assembly, and use of an inexpensive cryogenic stage that can be fabricated in any lab for less than $40 with parts found at local hardware and grocery stores. This cryo-LM stage is designed for use with reflected light microscopes that are fitted with long working distance air objectives. For correlative cryo-LM and cryo-EM studies, we adapt the use of carbon coated standard 3-mm cryo-EM grids as specimen supports. After adsorbing the sample to the grid, previously established protocols for vitrifying the sample and transferring/handling the grid are followed to permit multi-technique imaging. As a result, this setup allows any laboratory with a reflected light microscope to have access to direct correlative imaging of frozen hydrated samples.

  17. Microscopic techniques bridging between nanoscale and microscale with an atomically sharpened tip - field ion microscopy/scanning probe microscopy/ scanning electron microscopy.

    Science.gov (United States)

    Tomitori, Masahiko; Sasahara, Akira

    2014-11-01

    Over a hundred years an atomistic point of view has been indispensable to explore fascinating properties of various materials and to develop novel functional materials. High-resolution microscopies, rapidly developed during the period, have taken central roles in promoting materials science and related techniques to observe and analyze the materials. As microscopies with the capability of atom-imaging, field ion microscopy (FIM), scanning tunneling microscopy (STM), atomic force microscopy (AFM) and transmission electron microscopy (TEM) can be cited, which have been highly evaluated as methods to ultimately bring forward the viewpoint of reductionism in materials science. On one hand, there have been difficulties to derive useful and practical information on large (micro) scale unique properties of materials using these excellent microscopies and to directly advance the engineering for practical materials. To make bridges over the gap between an atomic scale and an industrial engineering scale, we have to develop emergence science step-by-step as a discipline having hierarchical structures for future prospects by combining nanoscale and microscale techniques; as promising ways, the combined microscopic instruments covering the scale gap and the extremely sophisticated methods for sample preparation seem to be required. In addition, it is noted that spectroscopic and theoretical methods should implement the emergence science.Fundamentally, the function of microscope is to determine the spatial positions of a finite piece of material, that is, ultimately individual atoms, at an extremely high resolution with a high stability. To define and control the atomic positions, the STM and AFM as scanning probe microscopy (SPM) have successfully demonstrated their power; the technological heart of SPM lies in an atomically sharpened tip, which can be observed by FIM and TEM. For emergence science we would like to set sail using the tip as a base. Meanwhile, it is significant

  18. All fiber based supercontinuum light source utilized for IR microscopy

    DEFF Research Database (Denmark)

    Dupont, Sune; Petersen, Christian; Thøgersen, Jan

    2012-01-01

    An all fiber based supercontinuum light source is demonstrated for infrared microscopy. The high brightness and spatial coherence of the source facilitate fast high resolution measurements.......An all fiber based supercontinuum light source is demonstrated for infrared microscopy. The high brightness and spatial coherence of the source facilitate fast high resolution measurements....

  19. Cryo-planing for cryo-scanning electron microscopy.

    Science.gov (United States)

    Nijsse, J; van Aelst, A C

    1999-01-01

    In the past decade, investigators of cryo-planing for low-temperature scanning electron microscopy (cryo-SEM) have developed techniques that enable observations of flat sample surfaces. This study reviews these sample preparation techniques, compares and contrasts their results, and introduces modifications that improve results from cryo-planing. A prerequisite for all successful cryo-planing required a stable attachment of the specimen to a holder. In most cases, clamping with a screw mechanism and using indium as space-filler sufficed. Once this problem was solved, any of three existing cryo-planing methods could be used to provide successful results: cryo-milling, microtomy in a cold room, and cryo-ultramicrotomy. This study introduces modifications to the cryo-planing technique that produces flat surfaces of any desired plane through a specimen. These flat surfaces of frozen, fully hydrated samples can be used to improve observations from cryo-SEM as well as to enhance results from x-ray microanalysis and (digital) image analysis. Cryo-planing results of chrysanthemum (Dendranthema x grandiflorum Tzvelev) stems, hazel (Corylus avelane L.) stems, and repeseed (Brassica napus L.) pistils are presented to illustrate the use of the planing method on fibrous, hard, and delicate materials, respectively.

  20. 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.

  1. Band excitation method applicable to scanning probe microscopy

    Science.gov (United States)

    Jesse, Stephen [Knoxville, TN; Kalinin, Sergei V [Knoxville, TN

    2010-08-17

    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  2. Humidity effects on scanning polarization force microscopy imaging

    Science.gov (United States)

    Shen, Yue; Zhou, Yuan; Sun, Yanxia; Zhang, Lijuan; Wang, Ying; Hu, Jun; Zhang, Yi

    2017-08-01

    Scanning polarization force microscopy (SPFM) is a useful surface characterization technique to visually characterize and distinguish nanomaterial with different local dielectric properties at nanometer scale. In this paper, taking the individual one-atom-thick graphene oxide (GO) and reduced graphene oxide (rGO) sheets on mica as examples, we described the influences of environmental humidity on SPFM imaging. We found that the apparent heights (AHs) or contrast of SPFM imaging was influenced significantly by relative humidity (RH) at a response time of a few seconds. And this influence rooted in the sensitive dielectric constant of mica surface to the RH change. While dielectric properties of GO and rGO sheets were almost immune to the humidity change. In addition, we gave the method to determine the critical humidity at which the contrast conversion happened under different conditions. And this is important to the contrast control and repeatable imaging of SPFM through RH adjusting. These findings suggest a strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM, which is critically important for further distinguishment, manipulation, electronic applications, etc.

  3. Scanning reflection ion microscopy in a helium ion microscope

    Directory of Open Access Journals (Sweden)

    Yuri V. Petrov

    2015-05-01

    Full Text Available Reflection ion microscopy (RIM is a technique that uses a low angle of incidence and scattered ions to form an image of the specimen surface. This paper reports on the development of the instrumentation and the analysis of the capabilities and limitations of the scanning RIM in a helium ion microscope (HIM. The reflected ions were detected by their “conversion” to secondary electrons on a platinum surface. An angle of incidence in the range 5–10° was used in the experimental setup. It was shown that the RIM image contrast was determined mostly by surface morphology but not by the atomic composition. A simple geometrical analysis of the reflection process was performed together with a Monte Carlo simulation of the angular dependence of the reflected ion yield. An interpretation of the RIM image formation and a quantification of the height of the surface steps were performed. The minimum detectable step height was found to be approximately 5 nm. RIM imaging of an insulator surface without the need for charge compensation was successfully demonstrated.

  4. Breast tissue characterization with high-frequency scanning acoustic microscopy

    Science.gov (United States)

    Kumon, R. E.; Bruno, I.; Heartwell, B.; Maeva, E.

    2004-05-01

    We have performed imaging of breast tissue using scanning acoustic microscopy (SAM) in the range of 25-50 MHz with the goal of accurately and rapidly determining the structure and composition throughout the volume of the samples. In contrast to traditional histological slides, SAM images can be obtained without special preparation, sometimes even without sectioning, but with sufficiently high spatial resolution to give information comparable to surface optical images. As a result, the use of high-frequency SAM at the time of breast lumpectomy to identify disease-free margins has the potential to reduce reoperative rates, patient anxiety, and local recurrence. However, only limited work has been performed to characterize breast tissue in the frequency range above clinical ultrasound devices. The samples are 4-cm2-thick sections (2-3 mm) taken from mastectomies and preserved in formalin. They are placed between two plates and immersed in water during imaging. Attenuation images are acquired by focusing the acoustic beam at the top and bottom of the samples, although better results were obtained for bottom focusing. For purposes of comparison and identification of histological features, acoustical images will be presented along with optical images obtained from the same samples. [Work supported by CIHR.

  5. An overview on bioaerosols viewed by scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wittmaack, K. [GSF-National Research Centre for Environment and Health, Institute of Radiation Protection, 85758 Neuherberg (Germany)]. E-mail: wittmaack@gsf.de; Wehnes, H. [GSF-National Research Centre for Environment and Health, Institute of Pathology, 85758 Neuherberg (Germany); Heinzmann, U. [GSF-National Research Centre for Environment and Health, Institute of Pathology, 85758 Neuherberg (Germany); Agerer, R. [Ludwig-Maximilians University Munich, Department Biology, Biodiversity Research: Mycology, Menzinger Stasse 67, 80638 Munich (Germany)

    2005-06-15

    Bioaerosols suspended in ambient air were collected with single-stage impactors at a semiurban site in southern Germany during late summer and early autumn. Sampling was mostly carried out at a nozzle velocity of 35 m/s, corresponding to a minimum aerodynamic diameter (cut-off diameter) of aerosol particles of 0.8 {mu}m. The collected particles, sampled for short periods ({approx}15 min) to avoid pile-up, were characterized by scanning electron microscopy (SEM). The observed bioaerosols include brochosomes, fungal spores, hyphae, insect scales, hairs of plants and, less commonly, bacteria and epicuticular wax. Brochosomes, which serve as a highly water repellent body coating of leafhoppers, are hollow spheroids with diameters around 400 nm, resembling C{sub 60} or footballs (soccer balls). They are usually airborne not as individuals but in the form of large clusters containing up to 10,000 individual species or even more. Various types of spores and scales were observed, but assignment turned out be difficult due to the large number of fungi and insects from which they may have originated. Pollens were observed only once. The absence these presumably elastic particles suggests that they are frequently lost, at the comparatively high velocities, due to bounce-off from the nonadhesive impaction surfaces.

  6. Simplifying Electron Beam Channeling in Scanning Transmission Electron Microscopy (STEM).

    Science.gov (United States)

    Wu, Ryan J; Mittal, Anudha; Odlyzko, Michael L; Mkhoyan, K Andre

    2017-08-01

    Sub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam's angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Z regime, in which the probe's initial angular distribution controls intensity oscillations; and the intermediate-Z regime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.

  7. Scanning electron microscopy of eggs of Sabethes cyaneus.

    Science.gov (United States)

    Santos-Mallet, Jacenir; Sarmento, Juliana Soares; Alencar, Jeronimo; Müller, Gerson Azulim; Oliveira, Eliana Medeiros; Foster, Woodbridge A; Marcondes, Carlos Brisola

    2013-03-01

    Mosquitoes of the Neotropical genus Sabethes, some species of which are yellow fever vectors, most often develop through the immature stages in tree holes. Sabethes eggs have not been previously characterized using scanning electron microscopy. Eggs of Sabethes cyaneus (length: 349.6 +/- 2.7 microm; width: 172.6 +/- 1.14 microm; n = 10) are almost biconical when examined from the top. From a lateral perspective 2 surfaces can be seen. One surface is smooth and more convex, whereas the other is less convex and partially covered by a network from which many fungiform tubercles arise. The micropyle is situated on the smooth surface of the pointed anterior tip and is surrounded by an irregular row of tubercles, some of which are leaf shaped. No structures possibly involved in adhesion to surfaces are visible. When hatching, the egg splits dorsoventrally approximately two-thirds of the length from the anterior end. The tubercles appear to be water repellent, and the more convex/smoother surface is downturned, and this position on water was confirmed by direct observation. The eggs float free on the water surface.

  8. Scanning electron microscopy applied to seed-borne fungi examination.

    Science.gov (United States)

    Alves, Marcelo de Carvalho; Pozza, Edson Ampélio

    2009-07-01

    The aim of this study was to test the standard scanning electron microscopy (SEM) as a potential alternative to study seed-borne fungi in seeds, by two different conditions of blotter test and water restriction treatment. In the blotter test, seeds were subjected to conditions that enabled pathogen growth and expression, whereas the water restriction method consisted in preventing seed germination during the incubation period, resulting in the artificial inoculation of fungi. In the first condition, seeds of common bean (Phaseolus vulgaris L.), maize (Zea mays L.), and cotton (Gossypium hirsutum L.) were submitted to the standard blotter test and then prepared and observed with SEM. In the second condition, seeds of cotton (G. hirsutum), soybean (Glycine max L.), and common bean (P. vulgaris L.) were, respectively, inoculated with Colletotrichum gossypii var. cephalosporioides, Colletotrichum truncatum, and Colletotrichum lindemuthianum by the water restriction technique, followed by preparation and observation with SEM. The standard SEM methodology was adopted to prepare the specimens. Considering the seeds submitted to the blotter test, it was possible to identify Fusarium sp. on maize, C. gossypii var. cephalosporioides, and Fusarium oxysporum on cotton, Aspergillus flavus, Penicillium sp., Rhizopus sp., and Mucor sp. on common bean. Structures of C. gossypii var. cephalosporioides, C. truncatum, and C. lindemuthianum were observed in the surface of inoculated seeds. (c) 2009 Wiley-Liss, Inc.

  9. [Scanning electron microscopy findings in titanium middle ear prostheses].

    Science.gov (United States)

    Schwager, K

    2000-12-01

    Titanium as a biomaterial in ossicular replacement has widely spread within the last couple of years. 23 prostheses (12 PORPs, partial ossicular replacement prostheses and 11 TORPs total ossicular replacement prostheses) removed during revision surgery were studied using scanning electron microscopy. The average implantation time was 8 (range 3-15) months. The specimens were investigated regarding tissue growth, epithelialization, inflammation and cellular signs of rejection. Only few prostheses were totally covered by connective tissue or epithelium due to technical problems in removing the implant and the covering tissue as one specimen. But this offered the possibility to study the interface at the edges where the tissue was torn off. The connective tissue looked unremarkable. Polygonal squamous epithelium was detected on several implants. Respiratory epithelium with ciliated cells and mucus producing goblet cells was seen in two specimens. In cases of cholesteatoma or protrusion the explanted prostheses showed typical rosette-like formation of hornifying squamous epithelium. According to underlying disease a lymphocytic infiltration could be seen. There were no cellular signs of incompatibility noticed neither macrophages nor foreign body giant cells. From these investigations titanium seems to be a favorable biomaterial for ossicular replacement with good acceptance also in an implantation site showing chronic inflammation.

  10. Phase stabilized homodyne of infrared scattering type scanning near-field optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xiaoji G., E-mail: xgx214@lehigh.edu [Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Gilburd, Leonid; Walker, Gilbert C., E-mail: gwalker@chem.utoronto.ca [Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

    2014-12-29

    Scattering type scanning near-field optical microscopy (s-SNOM) allows sub diffraction limited spatial resolution. Interferometric homodyne detection in s-SNOM can amplify the signal and extract vibrational responses based on sample absorption. A stable reference phase is required for a high quality homodyne-detected near-field signal. This work presents the development of a phase stabilization mechanism for s-SNOM to provide stable homodyne conditions. The phase stability is found to be better than 0.05 rad for the mid infrared light source. Phase stabilization results in improved near field images and vibrational spectroscopies. Spatial inhomogeneities of the boron nitride nanotubes are measured and compared.

  11. Topographic contrast of ultrathin cryo-sections for correlative super-resolution light and electron microscopy

    Science.gov (United States)

    Mateos, José María; Guhl, Bruno; Doehner, Jana; Barmettler, Gery; Kaech, Andres; Ziegler, Urs

    2016-01-01

    Fluorescence microscopy reveals molecular expression at nanometer resolution but lacks ultrastructural context information. This deficit often hinders a clear interpretation of results. Electron microscopy provides this contextual subcellular detail, but protein identification can often be problematic. Correlative light and electron microscopy produces complimentary information that expands our knowledge of protein expression in cells and tissue. Inherent methodological difficulties are however encountered when combining these two very different microscopy technologies. We present a quick, simple and reproducible method for protein localization by conventional and super-resolution light microscopy combined with platinum shadowing and scanning electron microscopy to obtain topographic contrast from the surface of ultrathin cryo-sections. We demonstrate protein distribution at nuclear pores and at mitochondrial and plasma membranes in the extended topographical landscape of tissue. PMID:27666401

  12. EDITORIAL: Three decades of scanning tunnelling microscopy that changed the course of surface science Three decades of scanning tunnelling microscopy that changed the course of surface science

    Science.gov (United States)

    Ramachandra Rao, M. S.; Margaritondo, Giorgio

    2011-11-01

    Three decades ago, with a tiny tip of platinum, the scientific world saw the real space imaging of single atoms with unprecedented spatial resolution. This signalled the birth of one of the most versatile surface probes, based on the physics of quantum mechanical tunnelling: the scanning tunnelling microscope (STM). Invented in 1981 by Gerd Binnig and Heinrich Rohrer of IBM, Zurich, it led to their award of the 1986 Nobel Prize. Atoms, once speculated to be abstract entities used by theoreticians for mere calculations, can be seen to exist for real with the nano-eye of an STM tip that also gives real-space images of molecules and adsorbed complexes on surfaces. From a very fundamental perspective, the STM changed the course of surface science and engineering. STM also emerged as a powerful tool to study various fundamental phenomena relevant to the properties of surfaces in technological applications such as tribology, medical implants, catalysis, sensors and biology—besides elucidating the importance of local bonding geometries and defects, non-periodic structures and the co-existence of nano-scale phases. Atom-level probing, once considered a dream, has seen the light with the evolution of STM. An important off-shoot of STM was the atomic force microscope (AFM) for surface mapping of insulating samples. Then followed the development of a flurry of techniques under the general name of scanning probe microscopy (SPM). These techniques (STM, AFM, MFM, PFM etc) designed for atomic-scale-resolution imaging and spectroscopy, have led to brand new developments in surface analysis. All of these novel methods enabled researchers in recent years to image and analyse complex surfaces on microscopic and nanoscopic scales. All of them utilize a small probe for sensing the surface. The invention of AFM by Gerd Binnig, Calvin Quate and Christopher Gerber opened up new opportunities for characterization of a variety of materials, and various industrial applications could be

  13. Light-sheet optimization for microscopy

    Science.gov (United States)

    Wilding, Dean; Pozzi, Paolo; Soloviev, Oleg; Vdovin, Gleb; Verhaegen, Michel

    2016-03-01

    Aberrations, scattering and absorption degrade the performance light-sheet fluorescence microscopes (LSFM). An adaptive optics system to correct for these artefacts and to optimize the light-sheet illumination is presented. This system allows a higher axial resolution to be recovered over the field-of-view of the detection objective. It is standard selective plane illumination microscope (SPIM) configuration modified with the addition of a spatial light modulator (SLM) and a third objective for the detection of transmitted light. Optimization protocols use this transmission light allowing the extension the depth-of-field and correction of aberrations whilst retaining a thin optical section.

  14. Condenser-free contrast methods for transmitted-light microscopy

    OpenAIRE

    Webb, Kevin F.

    2014-01-01

    Phase contrast microscopy allows the study of highly transparent yet detail-rich specimens by producing intensity contrast from phase objects within the sample. Presented here is a generalized phase contrast illumination schema in which condenser optics are entirely abrogated, yielding a condenser- free yet highly effective method of obtaining phase contrast in transmitted-light microscopy. A ring of light emitting diodes (LEDs) is positioned within the light-path such that observation of the...

  15. Improved Visualization of Vertebrate Nuclear Pore Complexes by Field Emission Scanning Electron Microscopy

    National Research Council Canada - National Science Library

    Shaulov, Lihi; Harel, Amnon

    2012-01-01

    Field emission scanning electron microscopy (FESEM) can provide high-resolution three-dimensional surface imaging of many biological structures, including nuclear envelopes and nuclear pore complexes (NPCs...

  16. 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

  17. Outwitting the series resistance in scanning spreading resistance microscopy.

    Science.gov (United States)

    Schulze, A; Cao, R; Eyben, P; Hantschel, T; Vandervorst, W

    2016-02-01

    The performance of nanoelectronics devices critically depends on the distribution of active dopants inside these structures. For this reason, dopant profiling has been defined as one of the major metrology challenges by the international technology roadmap of semiconductors. Scanning spreading resistance microscopy (SSRM) has evolved as one of the most viable approaches over the last decade due to its excellent spatial resolution, sensitivity and quantification accuracy. However, in case of advanced device architectures like fins and nanowires a proper measurement of the spreading resistance is often hampered by the increasing impact of parasitic series resistances (e.g. bulk series resistance) arising from the confined nature of the aforementioned structures. In order to overcome this limitation we report in this paper the development and implementation of a novel SSRM mode (fast Fourier transform-SSRM: FFT-SSRM) which essentially decouples the spreading resistance from parasitic series resistance components. We show that this can be achieved by a force modulation (leading to a modulated spreading resistance signal) in combination with a lock-in deconvolution concept. In this paper we first introduce the principle of operation of the technique. We discuss in detail the underlying physical mechanisms as well as the technical implementation on a state-of-the-art atomic force microscope (AFM). We demonstrate the performance of FFT-SSRM and its ability to remove substantial series resistance components in practice. Eventually, the possibility of decoupling the spreading resistance from the intrinsic probe resistance will be demonstrated and discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Environmental scanning electron microscopy observation of the ultrastructure of Demodex.

    Science.gov (United States)

    Jing, Xu; Shuling, Guo; Ying, Liu

    2005-12-01

    In this study, numbers of Demodex of hair follicles and sebaceous glands were prepared and the ultrastructure (especially the mouthparts) of Demodex was observed firstly with environmental scanning electron microscopy (ESEM). The most suitable treatment methods and optimal environmental condition for observing the genus samples were found. The samples were washed with detergent and rinsed with distilled water, and then were taken to the specimen stage, on which there was carbon adhesive tape, using special tools. When the temperature was at 5 degrees C and chamber pressure at 5 mbar respectively, the surface of the samples could be fully imaged without covering water or dehydration. The sample surfaces were plump and clear without postmortem changes and charging artifacts. Detailed information about each part of Demodex was observed by ESEM, and clear three-dimensional images were recorded. The mouthparts of D. folliculorum were composed of a complex set of structures, which included a round oral opening, a sharp oral needle, and a special hypostome that looked like a longitudinal spindle in the central position. On the end segment of palpus, there were seven strong palpal claws located on each side of the mouthparts. D. folliculorum had special piercing mouthparts, while the mouthparts of D. brevis were a simpler structure. We could not observe the oral needle of D. brevis, and there were only five pairs of palpal claws on the end segment of palpus. The offensive organs of Demodex resulted in its pathogenic effects. After studying hundreds of Demodex, we identified both female and male species of D. folliculorum, but only females of D. brevis in our sample. (c) 2005 Wiley-Liss, Inc.

  19. Spectral analysis of irregular roughness artifacts measured by atomic force microscopy and laser scanning microscopy.

    Science.gov (United States)

    Chen, Yuhang; Luo, Tingting; Ma, Chengfu; Huang, Wenhao; Gao, Sitian

    2014-12-01

    Atomic force microscopy (AFM) and laser scanning microscopy (LSM) measurements on a series of specially designed roughness artifacts were performed and the results characterized by spectral analysis. As demonstrated by comparisons, both AFM and LSM can image the complex structures with high resolution and fidelity. When the surface autocorrelation length increases from 200 to 500 nm, the cumulative power spectral density spectra of the design, AFM and LSM data reach a better agreement with each other. The critical wavelength of AFM characterization is smaller than that of LSM, and the gap between the measured and designed critical wavelengths is reduced with an increase in the surface autocorrelation length. Topography measurements of surfaces with a near zero or negatively skewed height distribution were determined to be accurate. However, obvious discrepancies were found for surfaces with a positive skewness owing to more severe dilations of either the solid tip of the AFM or the laser tip of the LSM. Further surface parameter evaluation and template matching analysis verified that the main distortions in AFM measurements are tip dilations while those in LSM are generally larger and more complex.

  20. Light-sheet optimization for microscopy

    NARCIS (Netherlands)

    Wilding, D.; Pozzi, P.; Soloviev, O.A.; Vdovine, G.V.; Verhaegen, M.H.G.; Bifano, Thomas G.; Kubby, Joel; Gigan, Sylvain

    2016-01-01

    Aberrations, scattering and absorption degrade the performance light-sheet fluorescence microscopes (LSFM). An adaptive optics system to correct for these artefacts and to optimize the light-sheet illumination is presented. This system allows a higher axial resolution to be recovered over the

  1. Scanning tunneling microscopy III theory of STM and related scanning probe methods

    CERN Document Server

    Güntherodt, Hans-Joachim

    1993-01-01

    While the first two volumes on Scanning Tunneling Microscopy (STM) and its related scanning probe (SXM) methods have mainly concentrated on intro­ ducing the experimental techniques, as well as their various applications in different research fields, this third volume is exclusively devoted to the theory of STM and related SXM methods. As the experimental techniques including the reproducibility of the experimental results have advanced, more and more theorists have become attracted to focus on issues related to STM and SXM. The increasing effort in the development of theoretical concepts for STM/SXM has led to considerable improvements in understanding the contrast mechanism as well as the experimental conditions necessary to obtain reliable data. Therefore, this third volume on STM/SXM is not written by theorists for theorists, but rather for every scientist who is not satisfied by just obtaining real­ space images of surface structures by STM/SXM. After a brief introduction (Chap. 1), N. D. Lang first co...

  2. Plastic-to-Elastic Transition in Aggregated Emulsion Networks, Studied with Atomic Force Microscopy-Confocal Scanning Laser Microscopy Microrheology

    NARCIS (Netherlands)

    Filip, D.; Duits, Michael H.G.; Uricanu, V.I.; Mellema, J.

    2006-01-01

    In this paper, we demonstrate how the simultaneous application of atomic force microscopy (AFM) and confocal scanning laser microscopy (CSLM) can be used to characterize the (local) rheological properties of soft condensed matter at micrometer length scales. Measurement of AFM force curves as a

  3. The Observation of Martensite and Magnetic Domain Structures in Ni53Mn24Ga23 Shape Memory Alloys by Scanning Electron Acoustic Microscopy and Scanning Thermal Microscopy

    Science.gov (United States)

    Zhao, Kun-Yu; Zeng, Hua-Rong; Song, Hong-Zhang; Hui, Sen-Xing; Li, Guo-Rong; Yin, Qing-Rui

    2012-05-01

    We present observations of martensite variants and ferromagnetic domain structures of Ni53Mn24Ga23 ferromagnetic shape memory alloys with a pure tetragonal martensitic phase by using scanning electron acoustic microscopy (SEAM) and scanning thermal microscopy (SThM). Electron acoustic images show a polycrystalline morphology with martensite variants. Direct coincidence between crystallographic martensitic twin variants and magnetic domains is found. A domain-like structure, obtained by SThM, is firstly reported, and then confirmed by magnetic force microscopy (MFM). The experimental results will be helpful for investigating the local thermal properties of ferromagnets and understanding the relationship between martensite variants and magnetic domains.

  4. Spectroscopic infrared scanning near-field optical microscopy (IR-SNOM)

    Energy Technology Data Exchange (ETDEWEB)

    Vobornik, D. [Institut de Physique de la Matiere Complexe, Ecole Polytechnique Federale de Lausanne (EPFL), Station 3, CH-1015 Lausanne (Switzerland)]. E-mail: dusan.vobornik@epfl.ch; Margaritondo, G. [Institut de Physique de la Matiere Complexe, Ecole Polytechnique Federale de Lausanne (EPFL), Station 3, CH-1015 Lausanne (Switzerland); Sanghera, J.S. [Optical Sciences Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue SE, Washington, DC 20375 (United States); Thielen, P. [Optical Sciences Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue SE, Washington, DC 20375 (United States); Aggarwal, I.D. [Optical Sciences Division, U.S. Naval Research Laboratory, 4555 Overlook Avenue SE, Washington, DC 20375 (United States); Ivanov, B. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 31235 (United States); Tolk, N.H. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 31235 (United States); Manni, V. [Institute of Neurobiology and Molecular Medicine, 00133 Rome (Italy); Grimaldi, S. [Institute of Neurobiology and Molecular Medicine, 00133 Rome (Italy); Lisi, A. [Institute of Neurobiology and Molecular Medicine, 00133 Rome (Italy); Rieti, S. [Institute of Neurobiology and Molecular Medicine, 00133 Rome (Italy); Piston, D.W. [Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232 (United States); Generosi, R. [Istituto di Stuttura della Materia, via Fosso del Cavaliere 100, 00133 Rome (Italy); Luce, M. [Istituto di Stuttura della Materia, via Fosso del Cavaliere 100, 00133 Rome (Italy); Perfetti, P. [Istituto di Stuttura della Materia, via Fosso del Cavaliere 100, 00133 Rome (Italy); Cricenti, A. [Istituto di Stuttura della Materia, via Fosso del Cavaliere 100, 00133 Rome (Italy)

    2005-09-29

    Scanning near-field optical microscopy (SNOM or NSOM) is the technique with the highest lateral optical resolution available today, while infrared (IR) spectroscopy has a high chemical specificity. Combining SNOM with a tunable IR source produces a unique tool, IR-SNOM, capable of imaging distributions of chemical species with a 100 nm spatial resolution. We present in this paper boron nitride (BN) thin film images, where IR-SNOM shows the distribution of hexagonal and cubic phases within the sample. Exciting potential applications in biophysics and medical sciences are illustrated with SNOM images of the distribution of different chemical species within cells. We present in this article images with resolutions of the order of {lambda}/60 with SNOM working with infrared light. With our SNOM setup, we routinely get optical resolutions between 50 and 150 nm, regardless of the wavelength of the light used to illuminate the sample.

  5. Novel scanning electron microscopy methods for analyzing the 3D structure of the Golgi apparatus.

    Science.gov (United States)

    Koga, Daisuke; Ushiki, Tatsuo; Watanabe, Tsuyoshi

    2017-01-01

    The structure of the Golgi apparatus has been extensively examined by light and electron microscopy, but details of its three-dimensional (3D) structure have remained unclear because of the technical limitations of conventional microscopy techniques. To overcome this problem, we have developed several novel scanning electron microscopy (SEM) methods for observing the 3D structure of subcellular organelles including the Golgi apparatus: (1) an osmium maceration method that facilitates SEM observation of membranous organelles, including the Golgi apparatus, by selectively removing soluble cytoplasmic proteins, (2) an osmium impregnation/maceration method that combines an osmium impregnation method with the osmium maceration method to determine the polarity of the Golgi apparatus by SEM, (3) a correlative light and SEM method that combines a cryosectioning technique with the osmium maceration method to enable correlation of the immunocytochemical distribution of molecules with the 3D ultrastructure of the Golgi apparatus, and (4) array tomography based on the systematic collection and integration of SEM images of serial ultrathin sections on glass slides for revealing the 3D ultrastructure of the entire Golgi apparatus. Together, the novel SEM techniques listed above can reveal the complete 3D structure of the Golgi apparatus in different cell types.

  6. Redescription of Cichlidogyrus philander (Monogenea, Ancyrocephalidae using scanning electron microscopy (SEM and molecular analysis

    Directory of Open Access Journals (Sweden)

    Igeh Patience C

    2017-01-01

    Full Text Available The sclerotized structures of monogeneans have traditionally been studied by light microscopy and different staining techniques. Recently, enzymatic digestion followed by scanning electron microscopy (SEM has enabled the examination of structural details not visible with light microscopy. In order to obtain better, and more accurate, morphological information on sclerotized structures not affected by mounting medium or cover slip pressure, the sclerites of Cichlidogyrus philander Douëllou, 1993 (Monogenea, Ancyrocephalidae, collected from Pseudocrenilabrus philander (Weber, 1897, were redescribed using SEM. Parasites were collected from Padda Dam, Gauteng, South Africa and soft tissue was digested to release the sclerotized structures. The digested tissue also provided sufficient genetic material for molecular characterization of this species. Cichlidogyrus philander is characterised by a penis with a sharp, curved, lateral termination, an accessory piece with a hook-like extremity that may appear forked terminally, and lack of a visible vagina. The transverse bars have concave and convex surfaces with ribs on the concave surface. The dorsal bar bears fenestrations at the base of the auricles and the ventral and dorsal gripi are dissimilar. Furthermore, the large first pair of uncinuli shows lateral wings on the left side of the base. On top of this wing, a ball-like structure with a small fenestration is visible. Genetic characters derived from the 28S rDNA, the COI mitochondrial DNA and ITS1 rDNA regions distinguish C. philander from all other Cichlidogyrus sequenced species.

  7. Observation of the sweating in lipstick by scanning electron microscopy.

    Science.gov (United States)

    Seo, S Y; Lee, I S; Shin, H Y; Choi, K Y; Kang, S H; Ahn, H J

    1999-06-01

    The relationship between the wax matrix in lipstick and sweating has been investigated by observing the change of size and shape of the wax matrix due to sweating by Scanning Electron Microscopy (SEM). For observation by SEM, a lipstick sample was frozen in liquid nitrogen. The oil in the lipstick was then extracted in cold isopropanol (-70 degrees C) for 1-3 days. After the isopropanol was evaporated, the sample was sputtered with gold and examined by SEM. The change of wax matrix underneath the surface from fine, uniform structure to coarse, nonuniform structure resulted from the caking of surrounding wax matrix. The oil underneath the surface migrated to the surface of lipstick with sweating; consequently the wax matrix in that region was rearranged into the coarse matrix. In case of flamed lipstick, sweating was delayed and the wax matrix was much coarser than that of the unflamed one. The larger wax matrix at the surface region was good for including oil. The effect of molding temperature on sweating was also studied. As the molding temperature rose, sweating was greatly reduced and the size of the wax matrix increased. It was found that sweating was influenced by the compatibility of wax and oil. A formula consisting of wax and oil that have good compatibility has a tendency to reduce sweating and increase the size of the wax matrix. When pigments were added to wax and oil, the size of the wax matrix was changed, but in all cases sweating was increased due to the weakening of the binding force between wax and oil. On observing the thick membrane of wax at the surface of lipstick a month after molding it was also found that sweating was influenced by ageing. In conclusion, the structure of the wax matrix at the surface region of lipstick was changed with the process of flaming, molding temperature, compatibility of wax and oil, addition of pigment, and ageing. In most cases, as the size of the wax matrix was increased, sweating was reduced and delayed.

  8. Angular resolved light scattering microscopy on human chromosomes

    Science.gov (United States)

    Müller, Dennis; Stark, Julian; Kienle, Alwin

    2017-07-01

    Angular resolved scattering light measurements on chromosomes are compared to Discrete Dipole Approximation (DDA) simulations using Atomic Force Microscopy (AFM) based geometrical models. This could present a novel, marker-free method for human chromosome karyotyping.

  9. Imaging by in situ Scanning Tunnelling Microscopy and its Nanotechnological Perspectives

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2002-01-01

    in the interpretation of the imaging procedure. Other methods of in situ Scanning Probe Microscopy (in situ SPM), such as in situ Scanning Force Microscopy (in situ AFM) are considered for the sake of comparison and they are applied to imaging of non-conducting systems. Major results include demonstration of atomic...

  10. Potential Challenges in Near-Field Scanning Optical Microscopy for Space Applications

    Science.gov (United States)

    Vikram, Chandra S.; Witherow, William K.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Near-field scanning optical microscopy (NSOM) also called scanning near-field optical microscopy (SNOM) is now well accepted as a powerful tool for sub-wavelength (nanoscale in the optical region) spatial resolution microscopy and a large number of related tasks. The importance lies in the fact of strategic advantages of standard microscopy but with significantly enhanced resolution. Since many modern optical diagnostic techniques have found useful applications in space, it is logical to consider the future role of NSOM in such situations. For example, protein crystal growth study under microgravity conditions is a valid candidate. If applied successfully, processes at molecular level can be studied during the growth. NSOM has already been demonstrated to be useful for the study of such crystals here on earth. The basic principle of NSOM can be illustrated. The illumination-collection mode is shown although several other possible approaches exist. In this, the sample is illuminated and the light from the sample is collected through the same tiny aperture opening. A tapered optical fiber is scanned near the sample surface. The tip is coated generally with a metal with a sub-wavelength aperture opening. The tip-sample distance is maintained constant while scanning. Thus, the optical signal available for collection is generally a function of the optical properties of the sample surface. Since the aperture is sub-wavelength in diameter and the tip is held very close (again in the sub-wavelength domain) to the surface, the lateral resolution in the sub-wavelength domain is obtained. Thus, the typical wavelength- order resolution of ordinary microscopy can be significantly enhanced while maintaining the strategic advantages (no need of sample in vacuum chamber, electron beams, etc). Commercial NSOM systems play a key role in the success and widespread acceptance of the tool. These commercial systems work fairly well in laboratory conditions on earth. However, they may

  11. Nanolithography on hydrogen terminateed silicon by scanning probe microscopy

    NARCIS (Netherlands)

    Schönenberger, Christian; Kramer, Niels; Kramer, N.

    1996-01-01

    Scanning-probe microscopes (SPM), i.e. the scanning-tunneling and force microscopes, can be used to locally oxidize hydrogen-terminated silicon and hydrogenated amorphous silicon. Because of its reliability and potential for pattern transfer, this lithography process has found great attention and

  12. Big Data Analytics for Scanning Transmission Electron Microscopy Ptychography

    OpenAIRE

    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 ima...

  13. A Video Rate Confocal Laser Beam Scanning Light Microscope Using An Image Dissector

    Science.gov (United States)

    Goldstein, Seth R.; Hubin, Thomas; Rosenthal, Scott; Washburn, Clayton

    1989-12-01

    A video rate confocal reflected light microscope with no moving parts has been developed. Return light from an acousto-optically raster scanned laser beam is imaged from the microscope stage onto the photocathode of an Image Dissector Tube (IDT). Confocal operation is achieved by appropriately raster scanning with the IDT x and y deflection coils so as to continuously "sample" that portion of the photocathode that is being instantaneously illuminated by the return image of the scanning laser spot. Optimum IDT scan parameters and geometric distortion correction parameters are determined under computer control within seconds and are then continuously applied to insure system alignment. The system is operational and reflected light images from a variety of objects have been obtained. The operating principle can be extended to fluorescence and transmission microscopy.

  14. Hyperspectral microscopy to identify foodborne bacteria with optimum lighting source

    Science.gov (United States)

    Hyperspectral microscopy is an emerging technology for rapid detection of foodborne pathogenic bacteria. Since scattering spectral signatures from hyperspectral microscopic images (HMI) vary with lighting sources, it is important to select optimal lights. The objective of this study is to compare t...

  15. Telocytes and putative stem cells in the lungs: electron microscopy, electron tomography and laser scanning microscopy.

    Science.gov (United States)

    Popescu, Laurentiu M; Gherghiceanu, Mihaela; Suciu, Laura C; Manole, Catalin G; Hinescu, Mihail E

    2011-09-01

    This study describes a novel type of interstitial (stromal) cell - telocytes (TCs) - in the human and mouse respiratory tree (terminal and respiratory bronchioles, as well as alveolar ducts). TCs have recently been described in pleura, epicardium, myocardium, endocardium, intestine, uterus, pancreas, mammary gland, etc. (see www.telocytes.com ). TCs are cells with specific prolongations called telopodes (Tp), frequently two to three per cell. Tp are very long prolongations (tens up to hundreds of μm) built of alternating thin segments known as podomers (≤ 200 nm, below the resolving power of light microscope) and dilated segments called podoms, which accommodate mitochondria, rough endoplasmic reticulum and caveolae. Tp ramify dichotomously, making a 3-dimensional network with complex homo- and heterocellular junctions. Confocal microscopy reveals that TCs are c-kit- and CD34-positive. Tp release shed vesicles or exosomes, sending macromolecular signals to neighboring cells and eventually modifying their transcriptional activity. At bronchoalveolar junctions, TCs have been observed in close association with putative stem cells (SCs) in the subepithelial stroma. SCs are recognized by their ultrastructure and Sca-1 positivity. Tp surround SCs, forming complex TC-SC niches (TC-SCNs). Electron tomography allows the identification of bridging nanostructures, which connect Tp with SCs. In conclusion, this study shows the presence of TCs in lungs and identifies a TC-SC tandem in subepithelial niches of the bronchiolar tree. In TC-SCNs, the synergy of TCs and SCs may be based on nanocontacts and shed vesicles.

  16. Second-harmonic scanning optical microscopy of semiconductor quantum dots

    DEFF Research Database (Denmark)

    Vohnsen, B.; Bozhevolnyi, S.I.; Pedersen, K.

    2001-01-01

    Second-harmonic (SH) optical imaging of self-assembled InAlGaAs quantum dots (QD's) grown on a GaAs(0 0 1) substrate has been accomplished at room temperature by use of respectively a scanning far-field optical microscope in reflection mode and a scanning near-field optical microscope...... in transmission mode. In both cases the SH signal peaks at a pump wavelength of similar to 885 nm in correspondence to the maximum in the photoluminescence spectrum of the QD sample. SH near-field optical images exhibit spatial signal variations on a subwavelength scale that depend on the pump wavelength. We...

  17. High frame-rate multichannel beam-scanning microscopy based on Lissajous trajectories.

    Science.gov (United States)

    Sullivan, Shane Z; Muir, Ryan D; Newman, Justin A; Carlsen, Mark S; Sreehari, Suhas; Doerge, Chris; Begue, Nathan J; Everly, R Michael; Bouman, Charles A; Simpson, Garth J

    2014-10-06

    A simple beam-scanning optical design based on Lissajous trajectory imaging is described for achieving up to kHz frame-rate optical imaging on multiple simultaneous data acquisition channels. In brief, two fast-scan resonant mirrors direct the optical beam on a circuitous trajectory through the field of view, with the trajectory repeat-time given by the least common multiplier of the mirror periods. Dicing the raw time-domain data into sub-trajectories combined with model-based image reconstruction (MBIR) 3D in-painting algorithms allows for effective frame-rates much higher than the repeat time of the Lissajous trajectory. Since sub-trajectory and full-trajectory imaging are simply different methods of analyzing the same data, both high-frame rate images with relatively low resolution and low frame rate images with high resolution are simultaneously acquired. The optical hardware required to perform Lissajous imaging represents only a minor modification to established beam-scanning hardware, combined with additional control and data acquisition electronics. Preliminary studies based on laser transmittance imaging and polarization-dependent second harmonic generation microscopy support the viability of the approach both for detection of subtle changes in large signals and for trace-light detection of transient fluctuations.

  18. Atomic bonding effects in annular dark field scanning transmission electron microscopy. I. Computational predictions

    Energy Technology Data Exchange (ETDEWEB)

    Odlyzko, Michael L.; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Himmetoglu, Burak [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 and Materials Department, University of California, Santa Barbara, California 93106 (United States); Cococcioni, Matteo [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 and Theory and Simulations of Materials, National Centre for Computational Design and Discovery of Novel Materials, École polytechnique fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2016-07-15

    Annular dark field scanning transmission electron microscopy (ADF-STEM) image simulations were performed for zone-axis-oriented light-element single crystals, using a multislice method adapted to include charge redistribution due to chemical bonding. Examination of these image simulations alongside calculations of the propagation of the focused electron probe reveal that the evolution of the probe intensity with thickness exhibits significant sensitivity to interatomic charge transfer, accounting for observed thickness-dependent bonding sensitivity of contrast in all ADF-STEM imaging conditions. Because changes in image contrast relative to conventional neutral atom simulations scale directly with the net interatomic charge transfer, the strongest effects are seen in crystals with highly polar bonding, while no effects are seen for nonpolar bonding. Although the bonding dependence of ADF-STEM image contrast varies with detector geometry, imaging parameters, and material temperature, these simulations predict the bonding effects to be experimentally measureable.

  19. Atomic resolution on the (111 )B surface of mercury cadmium telluride by scanning tunneling microscopy

    Science.gov (United States)

    Zha, Fang-Xing; Hong, Feng; Pan, Bi-Cai; Wang, Yin; Shao, Jun; Shen, Xue-Chu

    2018-01-01

    The real-space atomic surface structure of mercury cadmium telluride was successfully achieved on the (111 )B surface of H g0.78C d0.22Te by ultrahigh-vacuum scanning tunneling microscopy (STM). The work casts light on the reconstructions of the (111 )B surface unraveling a (2 ×2 ) surface reconstruction induced by adatom adsorption of Cd. The other (2 ×2 ) surface reconstruction is clarified to be induced by the single Te vacancy, which is more stable than the reconstruction of multivacancies in contrast to the prevailing view. The simulated STM images are in good agreement with the experiments. We also observed an in situ morphology transition from the (1 ×1 ) structure to those (2 ×2 ) reconstructions, implying the stability of the reconstructions.

  20. An environmental sample chamber for reliable scanning transmission x-ray microscopy measurements under water vapor

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Stephen T.; Nigge, P.; Prakash, Shruti; Laskin, Alexander; Wang, Bingbing; Tyliszczak, Tolek; Leone, Stephen R.; Gilles, Mary K.

    2013-08-01

    We have designed, fabricated, and tested a compact gas-phase reactor for performing in situ soft x-ray scanning transmission x-ray microscopy (STXM) measurements. The reactor accommodates many gas atmospheres, including reactive or corrosive gasses, but was designed specically to address the needs of measurements under water vapor. An on-board sensor measures the relative humidity and temperature inside the reactor, minimizing uncertainties associated with measuring these quantities outside the instrument. The reactor mounts directly to the existing sample holder used in the majority of STXM instruments around the world and installs with minimal instrument reconguration. Using the reactor contributes over 85% less additional absorption compared to lling the STXM chamber with process gas, and results in much more stable imaging conditions. The reactor is in use at the STXM instruments at beamlines 11.0.2 and 5.3.2.2 at the Advanced Light Source.

  1. Development of scanning electrochemical microscopy for the investigation of photocatalysis at semiconductor surfaces

    CERN Document Server

    Fonseca, S M M C D

    2002-01-01

    This thesis is concerned with the development and application of scanning electrochemical microscopy (SECM) to investigate interfacial photoelectrochemical processes occurring at supported TiO sub 2 surfaces. The new SECM approach, involving both amperometric and potentiometric electrodes, was used to monitor interfacial photoprocesses with high spatial resolution. A new in situ photoelectrochemical approach to chemical actinometry has been developed and used to determine the light flux through a quartz fibre employed in the SECM system. In this system an ultramicroelectrode (UME) probe is positioned with high precision at a known distance close to a TiO sub 2 -coated fibre and used to detect reactants or products of the ongoing photodegradation process. The microelectrochemical actinometry approach was developed using the well-known liquid phase potassium ferrioxalate actinometer. The approach involved recording the steady-state current for Fe(lll) reduction at an SECM tip positioned close to the fibre. A st...

  2. Focusing and scanning microscopy with propagating surface plasmons

    NARCIS (Netherlands)

    Gjonaj, B.; Aulbach, Jochen; Johnson, P.M.; Mosk, Allard; Kuipers, L.; Lagendijk, Aart

    2013-01-01

    Here we demonstrate a novel surface plasmon polariton (SPP) microscope which is capable of imaging below the optical diffraction limit. A plasmonic lens, generated through phase-structured illumination, focuses SPPs down to their diffraction limit and scans the focus with steps as small as 10 nm.

  3. Scanning Emitter Lifetime Imaging Microscopy for Spontaneous Emission Control

    DEFF Research Database (Denmark)

    Frimmer, Martin; Chen, Yuntian; Koenderink, A. Femius

    2011-01-01

    We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nanophotonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment while...

  4. Apparent Barrier Height in Scanning Tunneling Microscopy Revisited

    DEFF Research Database (Denmark)

    Olesen, L.; Brandbyge, Mads; Sørensen, Mads Reinholdt

    1996-01-01

    The apparent barrier height phi(ap), that is, the rate of change of the logarithm of the conductance with tip-sample separation in a scanning tunneling microscope (STM), has been measured for Ni, Pt, and Au single crystal surfaces. The results show that phi(ap) is constant until point contact is ...

  5. Localization of fluorescently labeled structures in frozen-hydrated samples using integrated light electron microscopy.

    Science.gov (United States)

    Faas, F G A; Bárcena, M; Agronskaia, A V; Gerritsen, H C; Moscicka, K B; Diebolder, C A; van Driel, L F; Limpens, R W A L; Bos, E; Ravelli, R B G; Koning, R I; Koster, A J

    2013-03-01

    Correlative light and electron microscopy is an increasingly popular technique to study complex biological systems at various levels of resolution. Fluorescence microscopy can be employed to scan large areas to localize regions of interest which are then analyzed by electron microscopy to obtain morphological and structural information from a selected field of view at nm-scale resolution. Previously, an integrated approach to room temperature correlative microscopy was described. Combined use of light and electron microscopy within one instrument greatly simplifies sample handling, avoids cumbersome experimental overheads, simplifies navigation between the two modalities, and improves the success rate of image correlation. Here, an integrated approach for correlative microscopy under cryogenic conditions is presented. Its advantages over the room temperature approach include safeguarding the native hydrated state of the biological specimen, preservation of the fluorescence signal without risk of quenching due to heavy atom stains, and reduced photo bleaching. The potential of cryo integrated light and electron microscopy is demonstrated for the detection of viable bacteria, the study of in vitro polymerized microtubules, the localization of mitochondria in mouse embryonic fibroblasts, and for a search into virus-induced intracellular membrane modifications within mammalian cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Assessment of resin-dentin interfacial morphology of two ethanol-based universal adhesives: A scanning electron microscopy study

    OpenAIRE

    Awad, Mohamed Moustafa

    2017-01-01

    Objective: The objective of this study was to assess the resin-dentin interfacial morphology created by two universal adhesives using scanning electron microscopy (SEM). Materials and Methods: The occlusal surfaces of ten (n = 5) molars were reduced to expose a flat surface of dentin. Two universal adhesives, Scotchbond Universal Adhesive and Tetric N-Bond Universal, were independently applied to air-dried dentin. Light-cured resin-based composite restorative materials were used to incrementa...

  7. Near-infrared branding efficiently correlates light and electron microscopy.

    Science.gov (United States)

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  8. 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.

  9. 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.

  10. Simulation study of secondary electron images in scanning ion microscopy

    CERN Document Server

    Ohya, K

    2003-01-01

    The target atomic number, Z sub 2 , dependence of secondary electron yield is simulated by applying a Monte Carlo code for 17 species of metals bombarded by Ga ions and electrons in order to study the contrast difference between scanning ion microscopes (SIM) and scanning electron microscopes (SEM). In addition to the remarkable reversal of the Z sub 2 dependence between the Ga ion and electron bombardment, a fine structure, which is correlated to the density of the conduction band electrons in the metal, is calculated for both. The brightness changes of the secondary electron images in SIM and SEM are simulated using Au and Al surfaces adjacent to each other. The results indicate that the image contrast in SIM is much more sensitive to the material species and is clearer than that for SEM. The origin of the difference between SIM and SEM comes from the difference in the lateral distribution of secondary electrons excited within the escape depth.

  11. Optical characterication of probes for photon scanning tunnelling microscopy

    DEFF Research Database (Denmark)

    Vohnsen, Brian; Bozhevolnyi, Sergey I.

    1999-01-01

    The photon scanning tunnelling microscope is a well-established member of the family of scanning near-field optical microscopes used for optical imaging at the sub-wavelength scale. The quality of the probes, typically pointed uncoated optical fibres, used is however difficult to evaluate...... in a direct manner and has most often been inferred from the apparent quality of recorded optical images. Complicated near-field optical imaging characteristics, together with the possibility of topographically induced artefacts, however, has increased demands for a more reliable probe characterization...... technique. Here we present experimental results obtained for optical characterization of two different probes by imaging of a well-specified near-field intensity distribution at various spatial frequencies. In particular, we observe that a sharply pointed dielectric probe can be highly suitable for imaging...

  12. Integrated single- and two-photon light sheet microscopy using accelerating beams

    DEFF Research Database (Denmark)

    Piksarv, Peeter; Marti, Dominik; Le, Tuan

    2017-01-01

    We demonstrate the first light sheet microscope using propagation invariant, accelerating Airy beams that operates both in single- and two-photon modes. The use of the Airy beam permits us to develop an ultra compact, high resolution light sheet system without beam scanning. In two-photon mode......, an increase in the field of view over the use of a standard Gaussian beam by a factor of six is demonstrated. This implementation for light sheet microscopy opens up new possibilities across a wide range of biomedical applications, especially for the study of neuronal processes....

  13. Video rate near-field scanning optical microscopy

    Science.gov (United States)

    Bukofsky, S. J.; Grober, R. D.

    1997-11-01

    The enhanced transmission efficiency of chemically etched near-field optical fiber probes makes it possible to greatly increase the scanning speed of near-field optical microscopes. This increase in system bandwidth allows sub-diffraction limit imaging of samples at video rates. We demonstrate image acquisition at 10 frames/s, rate-limited by mechanical resonances in our scanner. It is demonstrated that the optical signal to noise ratio is large enough for megahertz single pixel acquisition rates.

  14. Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses.

    Science.gov (United States)

    Lorenz, Kathrine Osborn; Kakkassery, Joseph; Boree, Danielle; Pinto, David

    2014-09-01

    Limbal ring (also known as 'circle') contact lenses are becoming increasingly popular, especially in Asian markets because of their eye-enhancing effects. The pigment particles that give the eye-enhancing effects of these lenses can be found on the front or back surface of the contact lens or 'enclosed' within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of 'circle' contact lenses. Scanning electron microscopic (SEM) analysis was performed using a variable pressure Hitachi S3400N instrument to discern the placement of lens pigments. Atomic force microscopy (Dimension Icon AFM from Bruker Nano) was used to determine the surface roughness of the pigmented regions of the contact lenses. Atomic force microscopic analysis was performed in fluid phase under contact mode using a Sharp Nitride Lever probe (SNL-10) with a spring constant of 0.06 N/m. Root mean square (RMS) roughness values were analysed using a generalised linear mixed model with a log-normal distribution. Least square means and their corresponding 95% confidence intervals were estimated for each brand, location and pigment combination. SEM cross-sectional images at 500× and 2,000× magnification showed pigment on the surface of six of the seven lens types tested. The mean depth of pigment for 1-DAY ACUVUE DEFINE (1DAD) lenses was 8.1 μm below the surface of the lens, while the remaining lens types tested had pigment particles on the front or back surface. Results of the atomic force microscopic analysis indicated that 1DAD lenses had significantly lower root mean square roughness values in the pigmented area of the lens than the other lens types tested. SEM and AFM analysis revealed pigment on the surface of the lens for all types tested with the exception of 1DAD. Further research is required to determine if the difference in pigment location influences on-eye performance. © 2014 The Authors. Clinical and Experimental

  15. Contribution of Metal Layer Thickness for Quantitative Backscattered Electron Imaging of Field Emission Scanning Electron Microscopy

    National Research Council Canada - National Science Library

    Kim, Hyonchol; Takei, Hiroyuki; Negishi, Tsutomu; Kudo, Masato; Terazono, Hideyuki; Yasuda, Kenji

    2012-01-01

    ...) imaging in field emission scanning electron microscopy (FE-SEM) were studied to evaluate the potential of using these particles as simultaneously distinguishable labels of target molecules in FE-SEM studies...

  16. Quantitative detection of gold nanoparticles on individual, unstained cancer cells by Scanning Electron Microscopy

    NARCIS (Netherlands)

    Hartsuiker, Liesbeth; van Es, Peter; Petersen, Wilhelmina; van Leeuwen, Ton; Terstappen, Leonardus Wendelinus Mathias Marie; Otto, Cornelis

    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

  17. Combination of scanning probe microscopy techniques for evaluating the electrical parameters of individual multiwalled carbon nanotubes

    Science.gov (United States)

    Sokolov, D. V.; Davletkildeev, N. A.; Bolotov, V. V.; Lobov, I. A.

    2017-10-01

    Using two techniques of scanning probe microscopy, the electrical properties (work function, Fermi level position, free carriers’ concentration, electrical resistance, conductivity, and carriers’ mobility) of individual multiwalled carbon nanotubes were evaluated.

  18. An Error Analysis of Structured Light Scanning of Biological Tissue

    DEFF Research Database (Denmark)

    Jensen, Sebastian Hoppe Nesgaard; Wilm, Jakob; Aanæs, Henrik

    2017-01-01

    This paper presents an error analysis and correction model for four structured light methods applied to three common types of biological tissue; skin, fat and muscle. Despite its many advantages, structured light is based on the assumption of direct reflection at the object surface only....... This assumption is violated by most biological material e.g. human skin, which exhibits subsurface scattering. In this study, we find that in general, structured light scans of biological tissue deviate significantly from the ground truth. We show that a large portion of this error can be predicted with a simple......, statistical linear model based on the scan geometry. As such, scans can be corrected without introducing any specially designed pattern strategy or hardware. We can effectively reduce the error in a structured light scanner applied to biological tissue by as much as factor of two or three....

  19. Time-resolved scanning electron microscopy with polarization analysis

    Energy Technology Data Exchange (ETDEWEB)

    Frömter, Robert, E-mail: rfroemte@physik.uni-hamburg.de; Oepen, Hans Peter [Institut für Nanostruktur-und Festkörperphysik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Kloodt, Fabian; Rößler, Stefan; Frauen, Axel; Staeck, Philipp; Cavicchia, Demetrio R. [Institut für Nanostruktur-und Festkörperphysik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg (Germany); Bocklage, Lars [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg (Germany); Röbisch, Volker; Quandt, Eckhard [Institute for Materials Science, Christian-Albrechts-Universität zu Kiel, 24143 Kiel (Germany)

    2016-04-04

    We demonstrate the feasibility of investigating periodically driven magnetization dynamics in a scanning electron microscope with polarization analysis based on spin-polarized low-energy electron diffraction. With the present setup, analyzing the time structure of the scattering events, we obtain a temporal resolution of 700 ps, which is demonstrated by means of imaging the field-driven 100 MHz gyration of the vortex in a soft-magnetic FeCoSiB square. Owing to the efficient intrinsic timing scheme, high-quality movies, giving two components of the magnetization simultaneously, can be recorded on the time scale of hours.

  20. Observation of diamond turned OFHC copper using Scanning Tunneling Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grigg, D.A.; Russell, P.E.; Dow, T.A.

    1988-12-01

    Diamond turned OFHC copper samples have been observed within the past few months using the Scanning Tunneling Microscope. Initial results have shown evidence of artifacts which may be used to better understand the diamond turning process. The STM`s high resolution capability and three dimensional data representation allows observation and study of surface features unobtainable with conventional profilometry systems. Also, the STM offers a better quantitative means by which to analyze surface structures than the SEM. This paper discusses findings on several diamond turned OFHC copper samples having different cutting conditions. Each sample has been cross referenced using STM and SEM.

  1. Scanning transmission electron microscopy: Albert Crewe's vision and beyond.

    Science.gov (United States)

    Krivanek, Ondrej L; Chisholm, Matthew F; Murfitt, Matthew F; Dellby, Niklas

    2012-12-01

    Some four decades were needed to catch up with the vision that Albert Crewe and his group had for the scanning transmission electron microscope (STEM) in the nineteen sixties and seventies: attaining 0.5Å resolution, and identifying single atoms spectroscopically. With these goals now attained, STEM developments are turning toward new directions, such as rapid atomic resolution imaging and exploring atomic bonding and electronic properties of samples at atomic resolution. The accomplishments and the future challenges are reviewed and illustrated with practical examples. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. [Scanning electron microscopy of heat-damaged bone tissue].

    Science.gov (United States)

    Harsanyl, L

    1977-02-01

    Parts of diaphyses of bones were exposed to high temperature of 200-1300 degrees C. Damage to the bone tissue caused by the heat was investigated. The scanning electron microscopic picture seems to be characteristic of the temperature applied. When the bones heated to the high temperature of 700 degrees C characteristic changes appear on the periostal surface, higher temperatura on the other hand causes damage to the compact bone tissue and can be observed on the fracture-surface. Author stresses the importance of this technique in the legal medicine and anthropology.

  3. 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

    Since bleaching has become a popular procedure, the effect of peroxides on dental hard tissues is of great interest in research. Purpose: The aim of this in vitro study was to perform a qualitative analysis of the human enamel after the application of in-office bleaching agents, using Scanning...... characteristic of an erosive process that took place on human enamel. Depression areas, including the formation of craters, and exposure of enamel rods could also be detected. Conclusion: Bleaching effects on enamel morphology were randomly distributed throughout enamel surface and various degrees of enamel...

  4. Special raster scanning for reduction of charging effects in scanning electron microscopy.

    Science.gov (United States)

    Suzuki, Kazuhiko; Oho, Eisaku

    2014-01-01

    A special raster scanning (SRS) method for reduction of charging effects is developed for the field of SEM. Both a conventional fast scan (horizontal direction) and an unusual scan (vertical direction) are adopted for acquiring raw data consisting of many sub-images. These data are converted to a proper SEM image using digital image processing techniques. About sharpness of the image and reduction of charging effects, the SRS is compared with the conventional fast scan (with frame-averaging) and the conventional slow scan. Experimental results show the effectiveness of SRS images. By a successful combination of the proposed scanning method and low accelerating voltage (LV)-SEMs, it is expected that higher-quality SEM images can be more easily acquired by the considerable reduction of charging effects, while maintaining the resolution. © 2013 Wiley Periodicals, Inc.

  5. Nonlinear light-sheet fluorescence microscopy by photobleaching imprinting.

    Science.gov (United States)

    Gao, Liang; Zhu, Liren; Li, Chiye; Wang, Lihong V

    2014-04-06

    We present a nonlinear light-sheet fluorescence microscopy (LSFM) scheme based on photobleaching imprinting. By measuring photobleaching-induced fluorescence decay, our method simultaneously achieves a large imaging field of view and a thin optical section. Furthermore, the scattered-light-induced background is significantly reduced, considerably improving image contrast. Our method is expected to expand the application field of LSFM into the optical quasi-ballistic regime, enabling studies on non-transparent biological samples.

  6. Anticipating, measuring, and minimizing MEMS mirror scan error to improve laser scanning microscopy's speed and accuracy.

    Science.gov (United States)

    Giannini, John P; York, Andrew G; Shroff, Hari

    2017-01-01

    We describe a method to speed up microelectromechanical system (MEMS) mirror scanning by > 20x, while also improving scan accuracy. We use Landweber deconvolution to determine an input voltage which would produce a desired output, based on the measured MEMS impulse response. Since the MEMS is weakly nonlinear, the observed behavior deviates from expectations, and we iteratively improve our input to minimize this deviation. This allows customizable MEMS angle vs. time with <1% deviation from the desired scan pattern. We demonstrate our technique by optimizing a point scanning microscope's raster patterns to image mammal submandibular gland and pollen at ~10 frames/s.

  7. 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.

  8. In-situ Scanning Transmission X-Ray Microscopy of Catalytic Solids and Related Nanomaterials

    NARCIS (Netherlands)

    de Groot, F.M.F.; de Smit, E.; van Schooneveld, M.M.; Aramburo, L.R.; Weckhuysen, B.M.

    2013-01-01

    The present status of in-situ scanning transmission X-ray microscopy (STXM) is reviewed, with an emphasis on the abilities of the STXM technique in comparison with electron microscopy. The experimental aspects and interpretation of X-ray absorption spectroscopy (XAS) are briefly introduced and the

  9. Design and construction of a cost-efficient Arduino-based mirror galvanometer system for scanning optical microscopy

    Science.gov (United States)

    Hsu, Jen-Feng; Dhingra, Shonali; D'Urso, Brian

    2017-01-01

    Mirror galvanometer systems (galvos) are commonly employed in research and commercial applications in areas involving laser imaging, laser machining, laser-light shows, and others. Here, we present a robust, moderate-speed, and cost-efficient home-built galvo system. The mechanical part of this design consists of one mirror, which is tilted around two axes with multiple surface transducers. We demonstrate the ability of this galvo by scanning the mirror using a computer, via a custom driver circuit. The performance of the galvo, including scan range, noise, linearity, and scan speed, is characterized. As an application, we show that this galvo system can be used in a confocal scanning microscopy system.

  10. Core/shell nanofiber characterization by Raman scanning microscopy

    Science.gov (United States)

    Sfakis, Lauren; Sharikova, Anna; Tuschel, David; Costa, Felipe Xavier; Larsen, Melinda; Khmaladze, Alexander; Castracane, James

    2017-01-01

    Core/shell nanofibers are becoming increasingly popular for applications in tissue engineering. Nanofibers alone provide surface topography and increased surface area that promote cellular attachment; however, core/shell nanofibers provide the versatility of incorporating two materials with different properties into one. Such synthetic materials can provide the mechanical and degradation properties required to make a construct that mimics in vivo tissue. Many variations of these fibers can be produced. The challenge lies in the ability to characterize and quantify these nanofibers post fabrication. We developed a non-invasive method for the composition characterization and quantification at the nanoscale level of fibers using Confocal Raman microscopy. The biodegradable/biocompatible nanofibers, Poly (glycerol-sebacate)/Poly (lactic-co-glycolic) (PGS/PLGA), were characterized as a part of a fiber scaffold to quickly and efficiently analyze the quality of the substrate used for tissue engineering. PMID:28271000

  11. PSD microscopy: a new technique for adaptive local scanning of microscale objects.

    Science.gov (United States)

    Rahimi, Mehdi; Shen, Yantao

    2017-01-01

    A position-sensitive detector/device (PSD) is a sensor that is capable of tracking the location of a laser beam on its surface. PSDs are used in many scientific instruments and technical applications including but not limited to atomic force microscopy, human eye movement monitoring, mirrors or machine tool alignment, vibration analysis, beam position control and so on. This work intends to propose a new application using the PSD. That is a new microscopy system called scanning PSD microscopy. The working mechanism is about putting an object on the surface of the PSD and fast scanning its area with a laser beam. To achieve a high degree of accuracy and precision, a reliable framework was designed using the PSD. In this work, we first tried to improve the PSD reading and its measurement performance. This was done by minimizing the effects of noise, distortion and other disturbing parameters. After achieving a high degree of confidence, the microscopy system can be implemented based on the improved PSD measurement performance. Later to improve the scanning efficiency, we developed an adaptive local scanning system to scan the whole area of the PSD in a short matter of time. It was validated that our comprehensive and adaptive local scanning method can shorten the scanning time in order of hundreds of times in comparison with the traditional raster scanning without losing any important information about the scanned 2D objects. Methods are also introduced to scan very complicated objects with bifurcations and crossings. By incorporating all these methods, the new microscopy system is capable of scanning very complicated objects in the matter of a few seconds with a resolution that is in order of a few micrometers.

  12. eduSPIM: Light Sheet Microscopy in the Museum.

    Science.gov (United States)

    Jahr, Wiebke; Schmid, Benjamin; Weber, Michael; Huisken, Jan

    2016-01-01

    Light sheet microscopy (or selective plane illumination microscopy) is an important imaging technique in the life sciences. At the same time, this technique is also ideally suited for community outreach projects, because it produces visually appealing, highly dynamic images of living organisms and its working principle can be understood with basic optics knowledge. Still, the underlying concepts are widely unknown to the non-scientific public. On the occasion of the UNESCO International Year of Light, a technical museum in Dresden, Germany, launched a special, interactive exhibition. We built a fully functional, educational selective plane illumination microscope (eduSPIM) to demonstrate how developments in microscopy promote discoveries in biology. To maximize educational impact, we radically reduced a standard light sheet microscope to its essential components without compromising functionality and incorporated stringent safety concepts beyond those needed in the lab. Our eduSPIM system features one illumination and one detection path and a sealed sample chamber. We image fixed zebrafish embryos with fluorescent vasculature, because the structure is meaningful to laymen and visualises the optical principles of light sheet microscopy. Via a simplified interface, visitors acquire fluorescence and transmission data simultaneously. The universal concepts presented here may also apply to other scientific approaches that are communicated to laymen in interactive settings. The specific eduSPIM design is adapted easily for various outreach and teaching activities. eduSPIM may even prove useful for labs needing a simple SPIM. A detailed parts list and schematics to rebuild eduSPIM are provided.

  13. Identification of sandstone core damage using scanning electron microscopy

    Science.gov (United States)

    Ismail, Abdul Razak; Jaafar, Mohd Zaidi; Sulaiman, Wan Rosli Wan; Ismail, Issham; Shiunn, Ng Yinn

    2017-12-01

    Particles and fluids invasion into the pore spaces causes serious damage to the formation, resulting reduction in petroleum production. In order to prevent permeability damage for a well effectively, the damage mechanisms should be identified. In this study, water-based drilling fluid was compared to oil-based drilling fluids based on microscopic observation. The cores were damaged by several drilling fluid systems. Scanning electron microscope (SEM) was used to observe the damage mechanism caused by the drilling fluids. Results showed that the ester based drilling fluid system caused the most serious damage followed by synthetic oil based system and KCI-polymer system. Fine solids and filtrate migration and emulsion blockage are believed to be the major mechanisms controlling the changes in flow properties for the sandstone samples.

  14. The theory and practice of high resolution scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Joy, D.C. (Tennessee Univ., Knoxville, TN (USA) Oak Ridge National Lab., TN (USA))

    1990-01-01

    Recent advances in instrumentation have produced the first commercial examples of what can justifiably be called High Resolution Scanning Electron Microscopes. The key components of such instruments are a cold field emission gun, a small-gap immersion probe-forming lens, and a clean dry-pumped vacuum. The performance of these microscopes is characterized by several major features including a spatial resolution, in secondary electron mode on solid specimens, which can exceed 1nm on a routine basis; an incident probe current density of the order of 10{sup 6} amps/cm{sup 2}; and the ability to maintain these levels of performance over an accelerating voltage range of from 1 to 30keV. This combination of high resolution, high probe current, low contamination and flexible electron-optical conditions provides many new opportunitites for the application of the SEM to materials science, physics, and the life sciences. 27 refs., 14 figs.

  15. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-30

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  16. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-01

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  17. Three-dimensional imaging of plant cuticle architecture using confocal scanning laser microscopy.

    Science.gov (United States)

    Buda, Gregory J; Isaacson, Tal; Matas, Antonio J; Paolillo, Dominick J; Rose, Jocelyn K C

    2009-10-01

    Full appreciation of the roles of the plant cuticle in numerous aspects of physiology and development requires a comprehensive understanding of its biosynthesis and deposition; however, much is still not known about cuticle structure, trafficking and assembly. To date, assessment of cuticle organization has been dominated by 2D imaging, using histochemical stains in conjunction with light and fluorescence microscopy. This strategy, while providing valuable information, has limitations because it attempts to describe a complex 3D structure in 2D. An imaging technique that could accurately resolve 3D architecture would provide valuable additions to the growing body of information on cuticle molecular biology and biochemistry. We present a novel application of 3D confocal scanning laser microscopy for visualizing the architecture, deposition patterns and micro-structure of plant cuticles, using the fluorescent stain auramine O. We demonstrate the utility of this technique by contrasting the fruit cuticle of wild-type tomato (Solanum lycopersicum cv. M82) with those of cutin-deficient mutants. We also introduce 3D cuticle modeling based on reconstruction of serial optical sections, and describe its use in identification of several previously unreported features of the tomato fruit cuticle.

  18. Reproducibility in light microscopy: Maintenance, standards and SOPs.

    Science.gov (United States)

    Deagle, Rebecca C; Wee, Tse-Luen(Erika); Brown, Claire M

    2017-08-01

    Light microscopy has grown to be a valuable asset in both the physical and life sciences. It is a highly quantitative method available in individual research laboratories and often centralized in core facilities. However, although quantitative microscopy is becoming a customary tool in research, it is rarely standardized. To achieve accurate quantitative microscopy data and reproducible results, three levels of standardization must be considered: (1) aspects of the microscope, (2) the sample, and (3) the detector. The accuracy of the data is only as reliable as the imaging system itself, thereby imposing the need for routine standard performance testing. Depending on the task some maintenance procedures should be performed once a month, some before each imaging session, while others conducted annually. This text should be implemented as a resource for researchers to integrate with their own standard operating procedures to ensure the highest quality quantitative microscopy data. Copyright © 2017. Published by Elsevier Ltd.

  19. Plasmons and Electrons as Nanosecond-Fast Sensors for Scanning Tunneling Microscopy

    Science.gov (United States)

    Loth, Sebastian

    2014-03-01

    The ability to measure the fast dynamical evolution of atomic-scale systems often holds the key to their understanding. We combine fast pump-probe spectroscopy tools with low-temperature scanning tunneling microscopy to study atomically assembled arrays of magnetic atoms. The dynamical information quantifies spin lifetimes, magnetic stability and even allows identifying the cross-over between quantum spins and classical magnetism. The spin relaxation times of transition metal atoms can be measured by all-electronic pump probe spectroscopy in which nanosecond-fast voltage pulses excite the spins and probe the average time-dependent response by variations in the spin-polarized tunnel current. In addition, the fast evolution of the local electrostatic potential can be mapped by detecting plasmonic light emission from the STM tunnel junction with time correlating single photon counting. The combination of electrical stimulus and optical detection provides precise control of the excitation process of individual atoms enabling new experiments to probe charge and spin dynamics in the scanning tunneling microscope.

  20. Enumeration of leukocyte infiltration in solid tumors by confocal laser scanning microscopy

    Directory of Open Access Journals (Sweden)

    Amirkhosravi A

    2006-07-01

    Full Text Available Abstract Background Leukocytes commonly infiltrate solid tumors, and have been implicated in the mechanism of spontaneous regression in some cancers. Conventional techniques for the quantitative estimation of leukocyte infiltrates in tumors rely on light microscopy of immunostained thin tissue sections, in which an arbitrary assessment (based on low, medium or high levels of infiltration of antigen density is made by the pathologist. These estimates are relatively subjective and often require the opinion of a second pathologist. In addition, since thin tissue sections are cut, no data regarding the three-dimensional distribution of antigen can be obtained. Results To overcome these problems, we have designed a method to enumerate leukocyte infiltration into tumors, using confocal laser scanning microscopy of fluorescently immunostained leukocytes in thick tissue sections. Using image analysis software, a threshold was applied to eliminate unstained tissue and residual noise. The total antigen volume in the scanned tissue was calculated and divided by the mean cell volume (calculated by "seeding" ten individual cells to obtain the cell count. Using this method, we compared the calculated leukocyte counts with those obtained manually by ten laboratory personnel. There was no significant difference (P > 0.05 between the cell counts obtained by either method. We then compared leukocyte infiltration into seven tumors and matched non-malignant tissue obtained from the periphery of the resected tissue. There was a significant increase in the infiltration of all leukocyte subsets into the tumors compared to minimal numbers in the non-malignant tissue. Conclusion From these results we conclude that this method may be of considerable use for the enumeration of cells in tissues. Furthermore, since it can be performed by laboratory technical staff, less time input is required by the pathologist in assessing the degree of leukocyte infiltration into tumors.

  1. Fundamentals of fluorescence microscopy exploring life with light

    CERN Document Server

    Mondal, Partha Pratim

    2014-01-01

    This book starts at an introductory level and leads reader to the most advanced developments in fluorescence imaging and super-resolution techniques that have enabled the emergence of new disciplines such as nanobioimaging, multiphoton microscopy, photodynamic therapy, nanometrology and nanosensors. The interdisciplinary subject of fluorescence microscopy and imaging requires complete knowledge of imaging optics and molecular physics. So, this book approaches the subject by introducing optical imaging concepts before going deep into the advanced imaging systems and their applications. Molecular orbital theory forms the basis for understanding fluorescent molecules and thereby facilitates complete explanation of light-matter interaction at the geometrical focus. The two disciplines have some overlap since light controls the states of molecules and conversely, molecular states control the emitted light. These two mechanisms together determine essential fluorescence  factors and phenomena such as, molecular cro...

  2. Quantitative three-dimensional ice roughness from scanning electron microscopy

    Science.gov (United States)

    Butterfield, Nicholas; Rowe, Penny M.; Stewart, Emily; Roesel, David; Neshyba, Steven

    2017-03-01

    We present a method for inferring surface morphology of ice from scanning electron microscope images. We first develop a novel functional form for the backscattered electron intensity as a function of ice facet orientation; this form is parameterized using smooth ice facets of known orientation. Three-dimensional representations of rough surfaces are retrieved at approximately micrometer resolution using Gauss-Newton inversion within a Bayesian framework. Statistical analysis of the resulting data sets permits characterization of ice surface roughness with a much higher statistical confidence than previously possible. A survey of results in the range -39°C to -29°C shows that characteristics of the roughness (e.g., Weibull parameters) are sensitive not only to the degree of roughening but also to the symmetry of the roughening. These results suggest that roughening characteristics obtained by remote sensing and in situ measurements of atmospheric ice clouds can potentially provide more facet-specific information than has previously been appreciated.

  3. Scanning Electron Microscopy with Samples in an Electric Field

    Science.gov (United States)

    Frank, Ludĕk; Hovorka, Miloš; Mikmeková, Šárka; Mikmeková, Eliška; Müllerová, Ilona; Pokorná, Zuzana

    2012-01-01

    The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.

  4. OSTEOBLAST ADHESION OF BREAST CANCER CELLS WITH SCANNING ACOUSTIC MICROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Chiaki Miyasaka; Robyn R. Mercer; Andrea M. Mastro; Ken L. Telschow

    2005-03-01

    Breast cancer frequently metastasizes to the bone. Upon colonizing bone tissue, the cancer cells stimulate osteoclasts (cells that break bone down), resulting in large lesions in the bone. The breast cancer cells also affect osteoblasts (cells that build new bone). Conditioned medium was collected from a bone-metastatic breast cancer cell line, MDA-MB-231, and cultured with an immature osteoblast cell line, MC3T3-E1. Under these conditions the osteoblasts acquired a changed morphology and appeared to adherer in a different way to the substrate and to each other. To characterize cell adhesion, MC3T3-E1 osteoblasts were cultured with or without MDA-MB-231 conditioned medium for two days, and then assayed with a mechanical scanning acoustic reflection microscope (SAM). The SAM indicated that in normal medium the MC3T3-E1 osteoblasts were firmly attached to their plastic substrate. However, MC3T3-E1 cells cultured with MDA-MB-231 conditioned medium displayed both an abnormal shape and poor adhesion at the substrate interface. The cells were fixed and stained to visualize cytoskeletal components using optical microscopic techniques. We were not able to observe these differences until the cells were quite confluent after 7 days of culture. However, using the SAM, we were able to detect these changes within 2 days of culture with MDA-MB-231 conditioned medium

  5. Sequencing of adenine in DNA by scanning tunneling microscopy

    Science.gov (United States)

    Tanaka, Hiroyuki; Taniguchi, Masateru

    2017-08-01

    The development of DNA sequencing technology utilizing the detection of a tunnel current is important for next-generation sequencer technologies based on single-molecule analysis technology. Using a scanning tunneling microscope, we previously reported that dI/dV measurements and dI/dV mapping revealed that the guanine base (purine base) of DNA adsorbed onto the Cu(111) surface has a characteristic peak at V s = -1.6 V. If, in addition to guanine, the other purine base of DNA, namely, adenine, can be distinguished, then by reading all the purine bases of each single strand of a DNA double helix, the entire base sequence of the original double helix can be determined due to the complementarity of the DNA base pair. Therefore, the ability to read adenine is important from the viewpoint of sequencing. Here, we report on the identification of adenine by STM topographic and spectroscopic measurements using a synthetic DNA oligomer and viral DNA.

  6. 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

    2016-06-01

    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.

  7. Active current-noise cancellation for Scanning Tunneling Microscopy

    Science.gov (United States)

    Pabbi, Lavish; Shoop, Conner; Banerjee, Riju; Dusch, Bill; Hudson, E. W.

    The high sensitivity of the scanning tunneling microscope (STM) poses a barrier to its use in a noisy environment. Vibrational noise, whether structural or acoustic in source, manifests as relative motion between the probe tip and the sample, then appearing in the Z feedback that tries to cancel it. Here we describe an active noise cancellation process that nullifies this motion by adding a drive signal into the existing Z feedback loop. The drive is digitally calculated by actively monitoring vibrations measured by an accelerometer placed in-situ close to the STM head. By transferring the vibration cancellation effort to this drive signal, vibration-created noise in the Z-feedback (during topography) or current (during spectroscopy) is significantly reduced. This inexpensive and easy solution, requiring no major instrumental modifications, is ideal for those looking to place their STM in a noisier environment, for example in the presence of active refrigeration systems (e.g. pulse tube cryocoolers) or coupled to high-vibration instrumentation. This material is based upon work supported by the National Science Foundation under Grant No. 1229138.

  8. Scanning electron microscopy investigations regarding Adonis vernalis L. flower morphology

    Directory of Open Access Journals (Sweden)

    Irina Neta GOSTIN

    2009-11-01

    Full Text Available The floral morphology of Adonis vernalis L. was observed with a scanning electron microscope (SEM. The investigations are important to clarify some taxonomical problems and also could provide useful diagnostic elements for the identification of this medicinal plant in powdered materials. All floral organs are initiated spirally and centripetally and develop centripetally. The petals (8-12 are shorter than the sepals (5-6 in early developmental stages. The petals are disposed on spiral (with 3-4 whorls. The stamens (numerous are unbranched and reach maturity centripetally; they are free of the perianth. The anther walls consisting of a single layer epidermis in the anther wall surrounding the sporagenous tissue, one row of endothecium, two to four rows of middle layer and one row of tapetum layer. In the anther walls, the tapetal cells, by glandular type, persist later in ontogenesis. Pollen grains are tricolpate with echinate surface. The gynoecium is multiple, apocarpous with distinct carpels. The carpels are ascidiate from the beginning. At the base of each carpel, numerousness short, unicellular, trichomes are present. The stigma differentiates as two crests along the ventral slit of the ovary. Each carpel contains a single ovule inside the ovary cavity. The mature ovule is anatropous, with two integuments. It is almost parallel to the funicle.

  9. Fabrication and characterization of probes for combined scanning electrochemical/optical microscopy experiments.

    Science.gov (United States)

    Lee, Youngmi; Bard, Allen J

    2002-08-01

    A technique that combines scanning electrochemical microscopy (SECM) and optical microscopy (OM) was implemented with a new probe tip. The tip for scanning electrochemicaVoptical microscopy (SECM/OM) was constructed by insulating a typical gold-coated near-field scanning optical microscopy tip using electrophoretic anodic paint. Once fabricated, the tip was characterized by steady-state cyclic voltammetry, as well as optical and electrochemical approach experiments. This tip generated a stable steady-state current and well-defined SECM approach curves for both conductive and insulating substrates. Durable tips whose geometry was a ring with < 1 microm as outer ring radius could be consistently fabricated. Simultaneous electrochemical and optical images of an interdigitated array electrode were obtained with a resolution on the micrometer scale, demonstrating good performance of the tip as both an optical and an electrochemical probe for imaging microstructures. The SECM feedback current measurements were successfully employed to determine tip-substrate distances for imaging.

  10. An evaluation of confocal versus conventional imaging of biological structures by fluorescence light microscopy.

    Science.gov (United States)

    White, J G; Amos, W B; Fordham, M

    1987-07-01

    Scanning confocal microscopes offer improved rejection of out-of-focus noise and greater resolution than conventional imaging. In such a microscope, the imaging and condenser lenses are identical and confocal. These two lenses are replaced by a single lens when epi-illumination is used, making confocal imaging particularly applicable to incident light microscopy. We describe the results we have obtained with a confocal system in which scanning is performed by moving the light beam, rather than the stage. This system is considerably faster than the scanned stage microscope and is easy to use. We have found that confocal imaging gives greatly enhanced images of biological structures viewed with epifluorescence. The improvements are such that it is possible to optically section thick specimens with little degradation in the image quality of interior sections.

  11. Candida albicans morphologies revealed by scanning electron microscopy analysis

    Directory of Open Access Journals (Sweden)

    M. Staniszewska

    2013-09-01

    Full Text Available Scanning electron microscope (SEM observations were used to analyze particular morphologies of Candida albicans clinical isolate (strain 82 and mutants defective in hyphae-promoting genes EFG1 (strain HLC52 and/ or CPH1 (strains HLC54 and Can16. Transcription factors Efg1 and Cph1 play role in regulating filamentation and adhesion of C. albicans' morphologies. Comparative analysis of such mutants and clinical isolate showed that Efg1 is required for human serum-induced cell growth and morphological switching. In the study, distinct differences between ultrastructural patterns of clinical strain's and null mutants' morphologies were observed (spherical vs tube-like blastoconidia, or solid and fragile constricted septa vs only the latter observed in strains with EFG1 deleted. In addition, wild type strain displayed smooth colonies of cells in comparison to mutants which exhibited wrinkled phenotype. It was observed that blastoconidia of clinical strain exhibited either polarly or randomly located budding. Contrariwise, morphotypes of mutants showed either multiple polar budding or a centrally located single bud scar (mother-daughter cell junction distinguishing tube-like yeast/ pseudohyphal growth (the length-to-width ratios larger than 1.5. In their planktonic form of growth, blastoconidia of clinical bloodstream isolate formed constitutively true hyphae under undiluted human serum inducing conditions. It was found that true hyphae are essential elements for developing structural integrity of conglomerate, as mutants displaying defects in their flocculation and conglomerate-forming abilities in serum. While filamentation is an important virulence trait in C. albicans the true hyphae are the morphologies which may be expected to play a role in bloodstream infections.

  12. 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.

  13. Cryo-Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM)-in-SEM for Bio- and Organo-Mineral Interface Characterization in the Environment.

    Science.gov (United States)

    Wille, Guillaume; Hellal, Jennifer; Ollivier, Patrick; Richard, Annie; Burel, Agnes; Jolly, Louis; Crampon, Marc; Michel, Caroline

    2017-11-16

    Understanding biofilm interactions with surrounding substratum and pollutants/particles can benefit from the application of existing microscopy tools. Using the example of biofilm interactions with zero-valent iron nanoparticles (nZVI), this study aims to apply various approaches in biofilm preparation and labeling for fluorescent or electron microscopy and energy dispersive X-ray spectrometry (EDS) microanalysis for accurate observations. According to the targeted microscopy method, biofilms were sampled as flocs or attached biofilm, submitted to labeling using 4',6-diamidino-2-phenylindol, lectins PNA and ConA coupled to fluorescent dye or gold nanoparticles, and prepared for observation (fixation, cross-section, freezing, ultramicrotomy). Fluorescent microscopy revealed that nZVI were embedded in the biofilm structure as aggregates but the resolution was insufficient to observe individual nZVI. Cryo-scanning electron microscopy (SEM) observations showed nZVI aggregates close to bacteria, but it was not possible to confirm direct interactions between nZVI and cell membranes. Scanning transmission electron microscopy in the SEM (STEM-in-SEM) showed that nZVI aggregates could enter the biofilm to a depth of 7-11 µm. Bacteria were surrounded by a ring of extracellular polymeric substances (EPS) preventing direct nZVI/membrane interactions. STEM/EDS mapping revealed a co-localization of nZVI aggregates with lectins suggesting a potential role of EPS in nZVI embedding. Thus, the combination of divergent microscopy approaches is a good approach to better understand and characterize biofilm/metal interactions.

  14. 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.

  15. 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. © 2015 Wiley Periodicals, Inc.

  16. Contributed review: Review of integrated correlative light and electron microscopy.

    Science.gov (United States)

    Timmermans, F J; Otto, C

    2015-01-01

    New developments in the field of microscopy enable to acquire increasing amounts of information from large sample areas and at an increased resolution. Depending on the nature of the technique, the information may reveal morphological, structural, chemical, and still other sample characteristics. In research fields, such as cell biology and materials science, there is an increasing demand to correlate these individual levels of information and in this way to obtain a better understanding of sample preparation and specific sample properties. To address this need, integrated systems were developed that combine nanometer resolution electron microscopes with optical microscopes, which produce chemically or label specific information through spectroscopy. The complementary information from electron microscopy and light microscopy presents an opportunity to investigate a broad range of sample properties in a correlated fashion. An important part of correlating the differences in information lies in bridging the different resolution and image contrast features. The trend to analyse samples using multiple correlated microscopes has resulted in a new research field. Current research is focused, for instance, on (a) the investigation of samples with nanometer scale distribution of inorganic and organic materials, (b) live cell analysis combined with electron microscopy, and (c) in situ spectroscopic and electron microscopy analysis of catalytic materials, but more areas will benefit from integrated correlative microscopy.

  17. Light Microscopy and Polarized Microscopy: A Dermatological Tool to Diagnose Gray Hair Syndromes.

    Science.gov (United States)

    Chandravathi, P L; Karani, Hetal Deepak; Siddaiahgari, Sirisha Rani; Lingappa, Lokesh

    2017-01-01

    Gray hair syndromes are rare syndromes which have an autosomal recessive inheritance and are characterized by pigmentary dilution of skin and hair, defects in immunological function, and nervous system defects. They comprise three disorders namely Chediak-Higashi syndrome (CHS), Griscelli syndrome (GPS), and Elejalde syndrome. Clinically, it is difficult to distinguish these disorders as their clinical features may overlap. Hence, to make a correct diagnosis and differentiate between CHS and GPS light microscopic examination of skin and hair shafts as well as peripheral blood smear evaluations should be done. In cases where the diagnosis is not possible chromosomal analysis for specific mutations can be done. In resource-poor settings where chromosomal analysis is not possible, and light microscopy findings are inconclusive, polarized microscopy can serve as a useful tool to distinguish between CHS and GPS. We report three cases with gray hair syndromes where the diagnosis on light microscopy and polarized microscopy of hair shaft correlated with the bone marrow examination findings and chromosomal analysis, thus emphasizing the importance of a noninvasive, cost-effective, and time-saving alternative in the diagnosis of these syndromes.

  18. Correlative cryo-fluorescence and cryo-scanning electron microscopy as a straightforward tool to study host-pathogen interactions.

    Science.gov (United States)

    Strnad, Martin; Elsterová, Jana; Schrenková, Jana; Vancová, Marie; Rego, Ryan O M; Grubhoffer, Libor; Nebesářová, Jana

    2015-12-10

    Correlative light and electron microscopy is an imaging technique that enables identification and targeting of fluorescently tagged structures with subsequent imaging at near-to-nanometer resolution. We established a novel correlative cryo-fluorescence microscopy and cryo-scanning electron microscopy workflow, which enables imaging of the studied object of interest very close to its natural state, devoid of artifacts caused for instance by slow chemical fixation. This system was tested by investigating the interaction of the zoonotic bacterium Borrelia burgdorferi with two mammalian cell lines of neural origin in order to broaden our knowledge about the cell-association mechanisms that precedes the entry of the bacteria into the cell. This method appears to be an unprecedentedly fast (<3 hours), straightforward, and reliable solution to study the finer details of pathogen-host cell interactions and provides important insights into the complex and dynamic relationship between a pathogen and a host.

  19. Artifact mitigation of ptychography integrated with on-the-fly scanning probe microscopy

    Science.gov (United States)

    Huang, Xiaojing; Yan, Hanfei; Ge, Mingyuan; Öztürk, Hande; Nazaretski, Evgeny; Robinson, Ian K.; Chu, Yong S.

    2017-07-01

    We report our experiences with conducting ptychography simultaneously with the X-ray fluorescence measurement using the on-the-fly mode for efficient multi-modality imaging. We demonstrate that the periodic artifact inherent to the raster scan pattern can be mitigated using a sufficiently fine scan step size to provide an overlap ratio of >70%. This allows us to obtain transmitted phase contrast images with enhanced spatial resolution from ptychography while maintaining the fluorescence imaging with continuous-motion scans on pixelated grids. This capability will greatly improve the competence and throughput of scanning probe X-ray microscopy.

  20. 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.

  1. Spontaneous Polarization in Bio-organic Materials Studied by Scanning Pyroelectric Microscopy (SPEM) and Second Harmonic Generation Microscopy (SHGM)

    Science.gov (United States)

    Putzeys, T.; Wübbenhorst, M.; van der Veen, M. A.

    2015-06-01

    Bio-organic materials such as bones, teeth, and tendon generally show nonlinear optical (Masters and So in Handbook of Biomedical Nonlinear Optical Microscopy, 2008), pyro- and piezoelectric (Fukada and Yasuda in J Phys Soc Jpn 12:1158, 1957) properties, implying a permanent polarization, the presence of which can be rationalized by describing the growth of the sample and the creation of a polar axis according to Markov's theory of stochastic processes (Hulliger in Biophys J 84:3501, 2003; Batagiannis et al. in Curr Opin Solid State Mater Sci 17:107, 2010). Two proven, versatile techniques for probing spontaneous polarization distributions in solids are scanning pyroelectric microscopy (SPEM) and second harmonic generation microscopy (SHGM). The combination of pyroelectric scanning with SHG-microscopy in a single experimental setup leading to complementary pyroelectric and nonlinear optical data is demonstrated, providing us with a more complete image of the polarization in organic materials. Crystals consisting of a known polar and hyperpolarizable material, CNS (4-chloro-4-nitrostilbene) are used as a reference sample, to verify the functionality of the setup, with both SPEM and SHGM images revealing the same polarization domain information. In contrast, feline and human nails exhibit a pyroelectric response, but a second harmonic response is absent for both keratin containing materials, implying that there may be symmetry-allowed SHG, but with very inefficient second harmonophores. This new approach to polarity detection provides additional information on the polar and hyperpolar nature in a variety of (bio) materials.

  2. Observation of silicon carbide Schottky barrier diode under applied reverse bias using atomic force microscopy/Kelvin probe force microscopy/scanning capacitance force microscopy

    Science.gov (United States)

    Uruma, Takeshi; Satoh, Nobuo; Yamamoto, Hidekazu

    2017-08-01

    We have observed a commercial silicon-carbide Schottky barrier diode (SiC-SBD) using our novel analysis system, in which atomic force microscopy (AFM) is combined with both Kelvin probe force microscopy (KFM; for surface-potential measurement) and scanning capacitance force microscopy (SCFM; for differential-capacitance measurement). The results obtained for the SiC-SBD under an applied reverse bias indicate both the scan area in the sample and a peak value of the SCFM signal in the region where the existence of trapped electrons is deduced from the KFM analysis. Thus, our measurement system can be used to examine commercial power devices; however, novel polishing procedures are required in order to investigate the Schottky contact region.

  3. Correlative light-ion microscopy for biological applications

    Science.gov (United States)

    Bertazzo, Sergio; von Erlach, Thomas; Goldoni, Silvia; Çandarlıoğlu, Pelin L.; Stevens, Molly M.

    2012-04-01

    Here we report a new technique, Correlative Light-Ion Microscopy (CLIM), to correlate SEM-like micrographs with fluorescence images. This technique presents significant advantages over conventional methods in enabling topographical and biochemical information to be correlated with nanoscale resolution without destroying the fluorescence signal. We demonstrate the utility of CLIM for a variety of investigations of cell substrate interactions validating its potential to become a routine procedure in biomedical research.Here we report a new technique, Correlative Light-Ion Microscopy (CLIM), to correlate SEM-like micrographs with fluorescence images. This technique presents significant advantages over conventional methods in enabling topographical and biochemical information to be correlated with nanoscale resolution without destroying the fluorescence signal. We demonstrate the utility of CLIM for a variety of investigations of cell substrate interactions validating its potential to become a routine procedure in biomedical research. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr30431g

  4. Snow crystal imaging using scanning electron microscopy: III. Glacier ice, snow and biota

    Science.gov (United States)

    Rango, A.; Wergin, W.P.; Erbe, E.F.; Josberger, E.G.

    2000-01-01

    Low-temperature scanning electron microscopy (SEM) was used to observe metamorphosed snow, glacial firn, and glacial ice obtained from South Cascade Glacier in Washington State, USA. Biotic samples consisting of algae (Chlamydomonas nivalis) and ice worms (a species of oligochaetes) were also collected and imaged. In the field, the snow and biological samples were mounted on copper plates, cooled in liquid nitrogen, and stored in dry shipping containers which maintain a temperature of -196??C. The firn and glacier ice samples were obtained by extracting horizontal ice cores, 8 mm in diameter, at different levels from larger standard glaciological (vertical) ice cores 7.5 cm in diameter. These samples were cooled in liquid nitrogen and placed in cryotubes, were stored in the same dry shipping container, and sent to the SEM facility. In the laboratory, the samples were sputter coated with platinum and imaged by a low-temperature SEM. To image the firn and glacier ice samples, the cores were fractured in liquid nitrogen, attached to a specimen holder, and then imaged. While light microscope images of snow and ice are difficult to interpret because of internal reflection and refraction, the SEM images provide a clear and unique view of the surface of the samples because they are generated from electrons emitted or reflected only from the surface of the sample. In addition, the SEM has a great depth of field with a wide range of magnifying capabilities. The resulting images clearly show the individual grains of the seasonal snowpack and the bonding between the snow grains. Images of firn show individual ice crystals, the bonding between the crystals, and connected air spaces. Images of glacier ice show a crystal structure on a scale of 1-2 mm which is considerably smaller than the expected crystal size. Microscopic air bubbles, less than 15 ??m in diameter, clearly marked the boundaries between these crystal-like features. The life forms associated with the glacier were

  5. EPS composition and calcification potential of tufa-dominating cyanobacteria investigated by Scanning Transmission X-ray Microscopy (STXM) and Laser Scanning Microscopy (LSM)

    Science.gov (United States)

    Zippel, Barbara; Dynes, James J.; Obst, Martin; Lawrence, John R.; Neu, Thomas R.

    2010-05-01

    Tufa deposits in freshwater habitats are the result of calcium carbonate precipitation within interfacial microbial ecosystems. Calcite precipitation is influenced by the saturation index and the occurrence of extracellular polymeric substances (EPS) which are produced by a variety of microorganisms. In theory, the first important step of biologically induced calcification processes is the adsorption of calcium ions by extracellular polymeric substances (EPS) produced by cyanobacteria. In the present study we take advantage of Laser Scanning Microscopy (LSM) and combine it with Synchrotron imaging using Scanning Transmission X-ray Microscopy (STXM). STXM represents a technique that allows simultaneous analysis of inorganic and organic constituents as a scale of 50 nm. By means of STXM it is possible to differentiate between calcium carbonate phases at the Ca L-edge. Furthermore, STXM has also been used at the C K-edge to map the major biomolecules (proteins, lipids, and polysaccharides). The purpose of this study is to find out if there are differences in calcium adsorption depending on specific composition of the EPS produced by filamentous cyanobacteria isolated from a German hard water creek (Westerhöfer Bach, Harz Mountains). The goal was to elucidate the potential of biofilms constituents, including microbial cell surfaces as well as extracellular polymeric substances, in triggering the formation of calcium carbonate in tufa systems. For this purpose three filamentous cyanobacteria (Pseudanabaena sp., Leptolyngbya sp. and Nostoc sp.) were cultivated in creek-adapted as well as standard media (BG11) on polycarbonate slides. In situ EPS composition was detected by means of fluorescence lectin-binding approach (FLBA) using 23 commercially available lectins with different specificities for mono- and disaccharides and amino sugars. For CaCO3 nucleation experiments cyanobacterial biofilms grown on polycarbonate slides were deposited in NaHCO3/CaCl2 solutions

  6. eduSPIM: Light Sheet Microscopy in the Museum.

    Directory of Open Access Journals (Sweden)

    Wiebke Jahr

    Full Text Available Light sheet microscopy (or selective plane illumination microscopy is an important imaging technique in the life sciences. At the same time, this technique is also ideally suited for community outreach projects, because it produces visually appealing, highly dynamic images of living organisms and its working principle can be understood with basic optics knowledge. Still, the underlying concepts are widely unknown to the non-scientific public. On the occasion of the UNESCO International Year of Light, a technical museum in Dresden, Germany, launched a special, interactive exhibition. We built a fully functional, educational selective plane illumination microscope (eduSPIM to demonstrate how developments in microscopy promote discoveries in biology.To maximize educational impact, we radically reduced a standard light sheet microscope to its essential components without compromising functionality and incorporated stringent safety concepts beyond those needed in the lab. Our eduSPIM system features one illumination and one detection path and a sealed sample chamber. We image fixed zebrafish embryos with fluorescent vasculature, because the structure is meaningful to laymen and visualises the optical principles of light sheet microscopy. Via a simplified interface, visitors acquire fluorescence and transmission data simultaneously.The universal concepts presented here may also apply to other scientific approaches that are communicated to laymen in interactive settings. The specific eduSPIM design is adapted easily for various outreach and teaching activities. eduSPIM may even prove useful for labs needing a simple SPIM. A detailed parts list and schematics to rebuild eduSPIM are provided.

  7. Using Light Sheet Fluorescence Microscopy to Image Zebrafish Eye Development

    OpenAIRE

    Icha, Jaroslav; Schmied, Christopher; Sidhaye, Jaydeep; Tomancak, Pavel; Preibisch, Stephan; Norden, Caren

    2016-01-01

    Light sheet fluorescence microscopy (LSFM) is gaining more and more popularity as a method to image embryonic development. The main advantages of LSFM compared to confocal systems are its low phototoxicity, gentle mounting strategies, fast acquisition with high signal to noise ratio and the possibility of imaging samples from various angles (views) for long periods of time. Imaging from multiple views unleashes the full potential of LSFM, but at the same time it can create terabyte-sized data...

  8. Scanning ion conductance microscopy for visualizing the three-dimensional surface topography of cells and tissues.

    Science.gov (United States)

    Nakajima, Masato; Mizutani, Yusuke; Iwata, Futoshi; Ushiki, Tatsuo

    2018-01-01

    Scanning ion conductance microscopy (SICM), which belongs to the family of scanning probe microscopy, regulates the tip-sample distance by monitoring the ion current through the use of an electrolyte-filled nanopipette as the probing tip. Thus, SICM enables "contact-free" imaging of cell surface topography in liquid conditions. In this paper, we applied hopping mode SICM for obtaining topographical images of convoluted tissue samples such as trachea and kidney in phosphate buffered saline. Some of the SICM images were compared with the images obtained by scanning electron microscopy (SEM) after drying the same samples. We showed that the imaging quality of hopping mode SICM was excellent enough for investigating the three-dimensional surface structure of the soft tissue samples. Thus, SICM is expected to be used for imaging a wide variety of cells and tissues - either fixed or alive- at high resolution under physiologically relevant liquid conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    Science.gov (United States)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  10. Visualizing aquatic bacteria by light and transmission electron microscopy.

    Science.gov (United States)

    Silva, Thiago P; Noyma, Natália P; Duque, Thabata L A; Gamalier, Juliana P; Vidal, Luciana O; Lobão, Lúcia M; Chiarini-Garcia, Hélio; Roland, Fábio; Melo, Rossana C N

    2014-01-01

    The understanding of the functional role of aquatic bacteria in microbial food webs is largely dependent on methods applied to the direct visualization and enumeration of these organisms. While the ultrastructure of aquatic bacteria is still poorly known, routine observation of aquatic bacteria by light microscopy requires staining with fluorochromes, followed by filtration and direct counting on filter surfaces. Here, we used a new strategy to visualize and enumerate aquatic bacteria by light microscopy. By spinning water samples from varied tropical ecosystems in a cytocentrifuge, we found that bacteria firmly adhere to regular slides, can be stained by fluorochoromes with no background formation and fast enumerated. Significant correlations were found between the cytocentrifugation and filter-based methods. Moreover, preparations through cytocentrifugation were more adequate for bacterial viability evaluation than filter-based preparations. Transmission electron microscopic analyses revealed a morphological diversity of bacteria with different internal and external structures, such as large variation in the cell envelope and capsule thickness, and presence or not of thylakoid membranes. Our results demonstrate that aquatic bacteria represent an ultrastructurally diverse population and open avenues for easy handling/quantification and better visualization of bacteria by light microscopy without the need of filter membranes.

  11. Dislocation imaging for orthopyroxene using an atom-resolved scanning transmission electron microscopy.

    Science.gov (United States)

    Kumamoto, Akihito; Kogure, Toshihiro; Raimbourg, Hugues; Ikuhara, Yuichi

    2014-11-01

    Dislocations, one-dimensional lattice defects, appear as a microscopic phenomenon while they are formed in silicate minerals by macroscopic dynamics of the earth crust such as shear stress. To understand ductile deformation mechanisms of silicates, atomic structures of the dislocations have been examined using transmission electron microscopy (TEM). Among them, it has been proposed that {100} primary slip system of orthopyroxene (Opx) is dissociated into partial dislocations, and a stacking fault with the clinopyroxene (Cpx) structure is formed between the dislocations. This model, however, has not been determined completely due to the complex structures of silicates. Scanning transmission electron microscopy (STEM) has a potential to determine the structure of dislocations with single-atomic column sensitivity, particularly by using high-angle annular dark field (HAADF) and annular bright field (ABF) imaging with a probing aberration corrector.[1] Furthermore, successive analyses from light microscopy to atom-resolved STEM have been achieved by focused ion beam (FIB) sampling techniques.[2] In this study, we examined dislocation arrays at a low-angle grain boundary of ∼1° rotation about the b-axis in natural deformed Opx using a simultaneous acquisition of HAADF/ABF (JEM-ARM200F, JEOL) equipped with 100 mm2 silicon drift detector (SDD) for energy dispersive X-ray spectroscopy (EDS). Figure 1 shows averaged STEM images viewed along the b- axis of Opx extracted from repeating units. HAADF provides the cation-site arrangement, and ABF distinguishes the difference of slightly rotated SiO4 tetrahedron around the a- axis. This is useful to distinguish the change of stacking sequence between the partial dislocations. Two types of stacking faults with Cpx and protopyroxene (Ppx) structures were identified between three partial dislocations. Furthermore, Ca accumulation in M2 (Fe) site around the stacking faults was detected by STEM-EDS. Interestingly, Ca is

  12. Correlative microscopy: bridging the gap between fluorescence light microscopy and cryo-electron tomography.

    Science.gov (United States)

    Sartori, Anna; Gatz, Rudolf; Beck, Florian; Rigort, Alexander; Baumeister, Wolfgang; Plitzko, Juergen M

    2007-11-01

    Cryo-electron tomography of frozen-hydrated biological samples offers a means of studying large and complex cellular structures in three-dimensions and with nanometer-scale resolution. The low contrast of unstained biological material embedded in amorphous ice and the need to minimise the exposure of these radiation-sensitive samples to the electron beam result in a poor signal-to-noise ratio. This poses problems not only in the visualisation and interpretation of such tomograms, it is also a problem in surveying the sample and in finding regions which contain the features of interest and which are suitable for recording tomograms. To address this problem, we have developed a correlative fluorescence light microscopy-electron microscopy approach, which guides the search for the structures of interest and allows electron microscopy to zoom in on them. With our approach, the total dose spent on locating regions of interest is negligible. A newly designed cryo-holder allows imaging of fluorescently labelled samples after vitrification. The absolute coordinates of structures identified and located by cryo-light microscopy are transferred to the electron microscope via a Matlab-based user interface. We have successfully tested the experimental setup and the whole procedure with two types of adherent fluorescently labelled cells, a neuronal cell line and keratinocytes, both grown directly on EM grids.

  13. Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

    OpenAIRE

    Hermannsd?rfer, Justus; de Jonge, Niels

    2017-01-01

    Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid c...

  14. Data analysis using the Internet: the World Wide Web scanning probe microscopy data analysis system.

    Science.gov (United States)

    Williams, P M; Davies, M C; Roberts, C J; Tendler, S J

    1997-10-01

    The first interactive world-wide web-based image analysis system is presented (http://pharm6.pharm.nottingham.ac.uk/processing/main. html). The system, currently tailored to scanning probe microscopy image data, has been developed to permit the use of software algorithms developed within our laboratory by researchers throughout the world. The implementation and functionality of the scanning probe microscopy server is described. Feedback from users of the facility has demonstrated its value within the research community, and highlighted key operational issues which are to be addressed. A future role of Internet-based data processing software is also discussed.

  15. Scanning tunneling microscopy I general principles and applications to clean and adsorbate-covered surfaces

    CERN Document Server

    Wiesendanger, Roland

    1992-01-01

    Scanning Tunneling Microscopy I provides a unique introduction to a novel and fascinating technique that produces beautiful images of nature on an atomic scale. It is the first of three volumes that together offer a comprehensive treatment of scanning tunneling microscopy, its diverse applications, and its theoretical treatment. In this volume the reader will find a detailed description of the technique itself and of its applications to metals, semiconductors, layered materials, adsorbed molecules and superconductors. In addition to the many representative results reviewed, extensive references to original work will help to make accessible the vast body of knowledge already accumulated in this field.

  16. Local analysis of semiconductor nanoobjects by scanning tunneling atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Natalia A. Lashkova

    2015-03-01

    Full Text Available The features of the current–voltage (I–V measurements in local regions of semiconductor nanostructures by conductive atomic force microscopy (AFM are discussed. The standard procedure of I–V measurements in conductive AFM leads not infrequently to the thermomechanical stresses in the sample and, as a consequence, nonreproducibility and unreliability of measurements. The technique of obtaining reproducible current–voltage characteristics is proposed. According to the technique, a series of measurements of the selected scanning area in the mode of conducting AFM should be taken, each at the certain value of the potential. According to a series of scans I–V curve at a particular point (for any point of the scan was plotted. The program is realized in the LabVIEW software. The proposed method extends the capabilities of scanning probe microscopy in the diagnosis of nanostructured semiconductor materials.

  17. Atomic force microscopy and scanning electron microscopy analysis of daily disposable limbal ring contact lenses

    OpenAIRE

    Lorenz, Kathrine Osborn; Kakkassery, Joseph; Boree, Danielle; Pinto, David

    2014-01-01

    Background Limbal ring (also known as ‘circle’) contact lenses are becoming increasingly popular, especially in Asian markets because of their eye-enhancing effects. The pigment particles that give the eye-enhancing effects of these lenses can be found on the front or back surface of the contact lens or ‘enclosed’ within the lens matrix. The purpose of this research was to evaluate the pigment location and surface roughness of seven types of ‘circle’ contact lenses. Methods Scanning electron ...

  18. Superresolution upgrade for confocal spinning disk systems using image scanning microscopy (Conference Presentation)

    Science.gov (United States)

    Isbaner, Sebastian; Hähnel, Dirk; Gregor, Ingo; Enderlein, Jörg

    2017-02-01

    Confocal Spinning Disk Systems are widely used for 3D cell imaging because they offer the advantage of optical sectioning at high framerates and are easy to use. However, as in confocal microscopy, the imaging resolution is diffraction limited, which can be theoretically improved by a factor of 2 using the principle of Image Scanning Microscopy (ISM) [1]. ISM with a Confocal Spinning Disk setup (CSDISM) has been shown to improve contrast as well as lateral resolution (FWHM) from 201 +/- 20 nm to 130 +/- 10 nm at 488 nm excitation. A minimum total acquisition time of one second per ISM image makes this method highly suitable for 3D live cell imaging [2]. Here, we present a multicolor implementation of CSDISM for the popular Micro-Manager Open Source Microscopy platform. Since changes in the optical path are not necessary, this will allow any researcher to easily upgrade their standard Confocal Spinning Disk system at remarkable low cost ( 5000 USD) with an ISM superresolution option. [1]. Müller, C.B. and Enderlein, J. Image Scanning Microscopy. Physical Review Letters 104, (2010). [2]. Schulz, O. et al. Resolution doubling in fluorescence microscopy with confocal spinning-disk image scanning microscopy. Proceedings of the National Academy of Sciences of the United States of America 110, 21000-5 (2013).

  19. Scanning near-field optical microscopy on rough surfaces: applications in chemistry, biology, and medicine

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Shear-force apertureless scanning near-field optical microscopy (SNOM with very sharp uncoated tapered waveguides relies on the unexpected enhancement of reflection in the shear-force gap. It is the technique for obtaining chemical (materials contrast in the optical image of “real world” surfaces that are rough and very rough without topographical artifacts, and it is by far less complicated than other SNOM techniques that can only be used for very flat surfaces. The experimental use of the new photophysical effect is described. The applications of the new technique are manifold. Important mechanistic questions in solid-state chemistry (oxidation, diazotization, photodimerization, surface hydration, hydrolysis are answered with respect to simultaneous AFM (atomic force microscopy and detailed crystal packing. Prehistoric petrified bacteria and concomitant pyrite inclusions are also investigated with local RAMAN SNOM. Polymer beads and unstained biological objects (rabbit heart, shrimp eye allow for nanoscopic analysis of cell organelles. Similarly, human teeth and a cancerous tissue are analyzed. Bladder cancer tissue is clearly differentiated from healthy tissue without staining and this opens a new highly promising diagnostic tool for precancer diagnosis. Industrial applications are demonstrated at the corrosion behavior of dental alloys (withdrawal of a widely used alloy, harmless substitutes, improvement of paper glazing, behavior of blood bags upon storage, quality assessment of metal particle preparations for surface enhanced RAMAN spectroscopy, and determination of diffusion coefficient and light fastness in textile fiber dyeing. The latter applications include fluorescence SNOM. Local fluorescence SNOM is also used in the study of partly aggregating dye nanoparticles within resin/varnish preparations. Unexpected new insights are obtained in all of the various fields that cannot be obtained by other techniques.

  20. 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.

  1. Simultaneous Bright-Field and Dark-Field Scanning Transmission Electron Microscopy in Scanning Electron Microscopy: A New Approach for Analyzing Polymer System Morphology

    Science.gov (United States)

    Patel, Binay S.

    Scanning transmission electron microscopy in scanning electron microscopy (STEM-IN-SEM) is a convenient technique for polymer characterization. Utilizing the lower accelerating voltages, larger field of view and, exclusion of post-specimen projection lens in an SEM; STEM-IN-SEM has shown results comparable to transmission electron microscopy (TEM) observation of polymer morphology. Various specimen-holder geometries and detector arrangements have been used for bright field (BF) STEM-IN-SEM imaging. To further the characterization potential of STEM-IN-SEM a new specimen holder has been developed to facilitate simultaneous BF and dark field (DF) STEM-IN-SEM imaging. A new specimen holder and a new microscope configuration were designed for this new imaging technique. BF and DF signals were maximized for optimal STEM-IN-SEM imaging. BF signal intensities were found to be twice as large as DF signal intensities. BF and DF STEM-IN-SEM imaging spatial resolutions are limited to 1.8 nm and approximately 5 nm, respectively. Simultaneous BF & DF STEM-IN-SEM imaging is applicable to both industrial and academic research environments. Examples of commodity and engineering polymer morphology characterization are provided. Results are comparable to TEM observation and may serve as a suitable precursor to STEM characterization of polymer systems. Finally, future developments of various accessories for this technique are discussed.

  2. Confocal laser scanning microscopy. Using new technology to answer old questions in forensic investigations.

    Science.gov (United States)

    Turillazzi, Emanuela; Karch, Steven B; Neri, Margherita; Pomara, Cristoforo; Riezzo, Irene; Fineschi, Vittorio

    2008-03-01

    Confocal laser scanning microscopy (CLSM) is a relatively new technique for microscopic imaging. It has found a wide field of application in the general sphere of biological sciences. It has completely changed the study of cells and tissues by allowing greater resolution, optical sectioning of the sample and three-dimensional sanoke reconstruction. Confocal microscopy represents a valid, precious and useful tool capable of providing data (images) of unrivalled clearness and definition. This review discusses the possible applications of confocal microscopy in specific fields of forensic investigation, with specific regard to ballistics, forensic histopathology and toxicological pathology.

  3. Serial Block-Face Scanning Electron Microscopy to Reconstruct Three-Dimensional Tissue Nanostructure

    Directory of Open Access Journals (Sweden)

    Denk Winfried

    2004-01-01

    Full Text Available Three-dimensional (3D structural information on many length scales is of central importance in biological research. Excellent methods exist to obtain structures of molecules at atomic, organelles at electron microscopic, and tissue at light-microscopic resolution. A gap exists, however, when 3D tissue structure needs to be reconstructed over hundreds of micrometers with a resolution sufficient to follow the thinnest cellular processes and to identify small organelles such as synaptic vesicles. Such 3D data are, however, essential to understand cellular networks that, particularly in the nervous system, need to be completely reconstructed throughout a substantial spatial volume. Here we demonstrate that datasets meeting these requirements can be obtained by automated block-face imaging combined with serial sectioning inside the chamber of a scanning electron microscope. Backscattering contrast is used to visualize the heavy-metal staining of tissue prepared using techniques that are routine for transmission electron microscopy. Low-vacuum (20-60 Pa H2O conditions prevent charging of the uncoated block face. The resolution is sufficient to trace even the thinnest axons and to identify synapses. Stacks of several hundred sections, 50-70 nm thick, have been obtained at a lateral position jitter of typically under 10 nm. This opens the possibility of automatically obtaining the electron-microscope-level 3D datasets needed to completely reconstruct the connectivity of neuronal circuits.

  4. Light sheet-based fluorescence microscopy (LSFM) for the quantitative imaging of cells and tissues.

    Science.gov (United States)

    Pampaloni, Francesco; Chang, Bo-Jui; Stelzer, Ernst H K

    2015-04-01

    In light sheet-based fluorescence microscopy (LSFM), only the focal plane is illuminated by a laser light sheet. Hence, only the fluorophores within a thin volume of the specimen are excited. This reduces photo-bleaching and photo-toxic effects by several orders of magnitude compared with any other form of microscopy. Therefore, LSFM (aka single/selective-plane illumination microscopy [SPIM] or digitally scanned light sheet microscopy [DSLM]) is the technique of choice for the three-dimensional imaging of live or fixed and of small or large three-dimensional specimens. The parallel recording of millions of pixels with modern cameras provides an extremely fast acquisition speed. Recent developments address the penetration depth, the resolution and the recording speed of LSFM. The impact of LSFM on research areas such as three-dimensional cell cultures, neurosciences, plant biology and developmental biology is increasing at a rapid pace. The development of high-throughput LSFM is the next leap forward, allowing the application of LSFM in toxicology and drug discovery screening.

  5. Ultrafast axial scanning for two-photon microscopy via a digital micromirror device and binary holography.

    Science.gov (United States)

    Cheng, Jiyi; Gu, Chenglin; Zhang, Dapeng; Wang, Dien; Chen, Shih-Chi

    2016-04-01

    In this Letter, we present an ultrafast nonmechanical axial scanning method for two-photon excitation (TPE) microscopy based on binary holography using a digital micromirror device (DMD), achieving a scanning rate of 4.2 kHz, scanning range of ∼180  μm, and scanning resolution (minimum step size) of ∼270  nm. Axial scanning is achieved by projecting the femtosecond laser to a DMD programmed with binary holograms of spherical wavefronts of increasing/decreasing radii. To guide the scanner design, we have derived the parametric relationships between the DMD parameters (i.e., aperture and pixel size), and the axial scanning characteristics, including (1) maximum optical power, (2) minimum step size, and (3) scan range. To verify the results, the DMD scanner is integrated with a custom-built TPE microscope that operates at 60 frames per second. In the experiment, we scanned a pollen sample via both the DMD scanner and a precision z-stage. The results show the DMD scanner generates images of equal quality throughout the scanning range. The overall efficiency of the TPE system was measured to be ∼3%. With the high scanning rate, the DMD scanner may find important applications in random-access imaging or high-speed volumetric imaging that enables visualization of highly dynamic biological processes in 3D with submillisecond temporal resolution.

  6. Direct In Situ Viability Assessment of Bacteria in Probiotic Dairy Products Using Viability Staining in Conjunction with Confocal Scanning Laser Microscopy

    Science.gov (United States)

    Auty, M. A. E.; Gardiner, G. E.; McBrearty, S. J.; O'Sullivan, E. O.; Mulvihill, D. M.; Collins, J. K.; Fitzgerald, G. F.; Stanton, C.; Ross, R. P.

    2001-01-01

    The viability of the human probiotic strains Lactobacillus paracasei NFBC 338 and Bifidobacterium sp. strain UCC 35612 in reconstituted skim milk was assessed by confocal scanning laser microscopy using the LIVE/DEAD BacLight viability stain. The technique was rapid (diluent. PMID:11133474

  7. Structured Light Scanning of Skin, Muscle and Fat

    DEFF Research Database (Denmark)

    Wilm, Jakob; Jensen, Sebastian Hoppe Nesgaard; Aanæs, Henrik

    of error that various encoding strategies show, and propose an error correcting model, which can bring down the measurement bias considerably. Samples of raw and unprocessed pig tissue were used with the number of sampled surface points Nmeat = 1.2 * 106, Nskin = 4.0 * 106 and Nfat = 2.1 * 106 from 8......We investigate the quality of structured light 3D scanning on pig skin, muscle and fat. These particular materials are interesting in a number of industrial and medical use-cases, and somewhat challenging because they exhibit subsurface light scattering. Our goal therefor is to quantify the amount...

  8. Scanning Light Sheet Would Measure Deflection Of Beam

    Science.gov (United States)

    Tcheng, Ping; Monteith, James H.; Weisenborn, Michael D.; Franke, John M.; Jordan, Thomas L.

    1992-01-01

    Scanning-light-sheet apparatus designed to measure linear and angular displacement or deflection of structure. Intended specifically to measure deflection of beam-shaped truss structure. Includes conventional low-powered laser, lenses, mounts, single-axis optical scanner, several photodiodes, and electronic controller. Apparatus measures motion of structure and also used to determine positions, deflections, and velocities. Besides use in aerospace field, displacement measurements have many applications in construction-equipment and automotive industries.

  9. Alternative configuration scheme for signal amplification with scanning ion conductance microscopy

    Science.gov (United States)

    Kim, Joonhui; Kim, Seong-Oh; Cho, Nam-Joon

    2015-02-01

    Scanning Ion Conductance Microscopy (SICM) is an emerging nanotechnology tool to investigate the morphology and charge transport properties of nanomaterials, including soft matter. SICM uses an electrolyte filled nanopipette as a scanning probe and detects current changes based on the distance between the nanopipette apex and the target sample in an electrolyte solution. In conventional SICM, the pipette sensor is excited by applying voltage as it raster scans near the surface. There have been attempts to improve upon raster scanning because it can induce collisions between the pipette sidewalls and target sample, especially for soft, dynamic materials (e.g., biological cells). Recently, Novak et al. demonstrated that hopping probe ion conductance microscopy (HPICM) with an adaptive scan method can improve the image quality obtained by SICM for such materials. However, HPICM is inherently slower than conventional raster scanning. In order to optimize both image quality and scanning speed, we report the development of an alternative configuration scheme for SICM signal amplification that is based on applying current to the nanopipette. This scheme overcomes traditional challenges associated with low bandwidth requirements of conventional SICM. Using our alternative scheme, we demonstrate successful imaging of L929 fibroblast cells and discuss the capabilities of this instrument configuration for future applications.

  10. Alternative configuration scheme for signal amplification with scanning ion conductance microscopy.

    Science.gov (United States)

    Kim, Joonhui; Kim, Seong-Oh; Cho, Nam-Joon

    2015-02-01

    Scanning Ion Conductance Microscopy (SICM) is an emerging nanotechnology tool to investigate the morphology and charge transport properties of nanomaterials, including soft matter. SICM uses an electrolyte filled nanopipette as a scanning probe and detects current changes based on the distance between the nanopipette apex and the target sample in an electrolyte solution. In conventional SICM, the pipette sensor is excited by applying voltage as it raster scans near the surface. There have been attempts to improve upon raster scanning because it can induce collisions between the pipette sidewalls and target sample, especially for soft, dynamic materials (e.g., biological cells). Recently, Novak et al. demonstrated that hopping probe ion conductance microscopy (HPICM) with an adaptive scan method can improve the image quality obtained by SICM for such materials. However, HPICM is inherently slower than conventional raster scanning. In order to optimize both image quality and scanning speed, we report the development of an alternative configuration scheme for SICM signal amplification that is based on applying current to the nanopipette. This scheme overcomes traditional challenges associated with low bandwidth requirements of conventional SICM. Using our alternative scheme, we demonstrate successful imaging of L929 fibroblast cells and discuss the capabilities of this instrument configuration for future applications.

  11. EVALUATION OF COMPUTER-CONTROLLED SCANNING ELECTRON MICROSCOPY APPLIED TO AN AMBIENT URBAN AEROSOL SAMPLE

    Science.gov (United States)

    Recent interest in monitoring and speciation of particulate matter has led to increased application of scanning electron microscopy (SEM) coupled with energy-dispersive x-ray analysis (EDX) to individual particle analysis. SEM/EDX provides information on the size, shape, co...

  12. 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.

  13. Bright-field scanning confocal electron microscopy using a double aberration-corrected transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng; Behan, Gavin; Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Nellist, Peter D., E-mail: peter.nellist@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Cosgriff, Eireann C.; D' Alfonso, Adrian J.; Morgan, Andrew J.; Allen, Leslie J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Hashimoto, Ayako [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); Takeguchi, Masaki [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); High Voltage Electron Microscopy Station, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Mitsuishi, Kazutaka [Advanced Nano-characterization Center, National Institute for Materials Science (NIMS), 3-13 Sakura, Tsukuba 305-0003 (Japan); Quantum Dot Research Center, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Shimojo, Masayuki [High Voltage Electron Microscopy Station, NIMS, 3-13 Sakura, Tsukuba 305-0003 (Japan); Advanced Science Research Laboratory, Saitama Institute of Technology, 1690 Fusaiji, Fukaya 369-0293 (Japan)

    2011-06-15

    Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored. -- Research Highlights: {yields} The confocal probe image in a scanning confocal electron microscopy image reveals information about the thickness and height of the crystalline layer. {yields} The form of the contrast in a three-dimensional bright-field scanning confocal electron microscopy image can be explained in terms of the confocal probe image. {yields} Despite the complicated form of the contrast in bright-field scanning confocal electron microscopy, we see that depth information is transferred on a 10 nm scale.

  14. 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

  15. 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...

  16. DTAF: an efficient probe to study cyanobacterial-plant interaction using confocal laser scanning microscopy (CLSM)

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2011-01-01

    A variety of microscopic techniques have been utilized to study cyanobacterial associations with plant roots, but confocal laser scanning microscopy (CLSM) is the least used due to the unavailability of a suitable fluorescent dye. Commonly used lectins have problems with their binding ability with

  17. DTAF: an efficient probe to study cyanobacterial-plant interaction using confocal laser scanning microscopy (CLSM).

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2011-01-01

    A variety of microscopic techniques have been utilized to study cyanobacterial associations with plant roots, but confocal laser scanning microscopy (CLSM) is the least used due to the unavailability of a suitable fluorescent dye. Commonly used lectins have problems with their binding ability with

  18. Scanning electron microscopy with polarization analysis for multilayered chiral spin textures

    NARCIS (Netherlands)

    Lucassen, Juriaan; Kloodt-Twesten, Fabian; Frömter, Robert; Oepen, Hans Peter; Duine, Rembert A.|info:eu-repo/dai/nl/304830127; Swagten, Henk J. M.; Koopmans, Bert; Lavrijsen, Reinoud

    We show that scanning electron microscopy with polarization analysis (SEMPA) that is sensitive to both in-plane magnetization components can be used to image the out-of-plane magnetized multi-domain state in multilayered chiral spin textures. By depositing a thin layer of Fe on top of the multilayer

  19. Batch fabrication of scanning microscopy probes for thermal and magnetic imaging using standard micromachining

    NARCIS (Netherlands)

    Sarajlic, Edin; Vermeer, Rolf; Delalande, M.Y.; Siekman, Martin Herman; Huijink, R.; Fujita, H.; Abelmann, Leon

    2010-01-01

    We present a process for batch fabrication of a novel scanning microscopy probe for thermal and magnetic imaging using standard micromachining and conventional optical contact lithography. The probe features an AFM-type cantilever with a sharp pyramidal tip composed of four freestanding silicon

  20. Preparation of Chemically Etched Tips for Ambient Instructional Scanning Tunneling Microscopy

    Science.gov (United States)

    Zaccardi, Margot J.; Winkelmann, Kurt; Olson, Joel A.

    2010-01-01

    A first-year laboratory experiment that utilizes concepts of electrochemical tip etching for scanning tunneling microscopy (STM) is described. This experiment can be used in conjunction with any STM experiment. Students electrochemically etch gold STM tips using a time-efficient method, which can then be used in an instructional grade STM that…

  1. RGB color coded images in scanning electron microscopy of biological surfaces

    Czech Academy of Sciences Publication Activity Database

    Kofroňová, Olga; Benada, Oldřich

    2017-01-01

    Roč. 61, č. 3 (2017), s. 349-352 ISSN 0001-723X R&D Projects: GA MŠk(CZ) LO1509; GA ČR(CZ) GA16-20229S Institutional support: RVO:61388971 Keywords : Biological surfaces * Color images * Scanning electron microscopy Subject RIV: EE - Microbiology, Virology Impact factor: 0.673, year: 2016

  2. Imaging inclusion complex formation in starch granules using confocal laser scanning microscopy

    NARCIS (Netherlands)

    Manca, Marianna; Woortman, Albert J. J.; Loos, Katja; Loi, Maria A.

    The tendency of amylose to form inclusion complexes with guest molecules has been an object of wide interest due to its fundamental role in food processing. Here we investigated the features of starch granules from several botanical sources using confocal laser scanning microscopy (CLSM) and

  3. 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.

  4. 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.

  5. Covalently Immobilised Cytochrome C Imaged by In Situ Scanning Tunnelling Microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Olesen, Klaus G.; Danilov, Alexey I.

    1997-01-01

    In situ scanning tunnelling microscopy (STM) imaging of cytochrome c (cyt c) on polycrystalline Pt surfaces and on Au(lll) was achieved first by covalent immobilisation of 3-aminopropyltriethoxysilane (3-APTS) brought to react with oxide present on the Pt surfaces. Covalently bound 3-APTS forms a...

  6. Elastic Changes of Capsule in a Rat Knee Contracture Model Assessed by Scanning Acoustic Microscopy

    Science.gov (United States)

    Hagiwara, Y.; Chimoto, E.; Ando, A.; Saijo, Y.; Itoi, E.

    Sound speed of a capsule in a rat knee contracture model was measured by scanning acoustic microscopy. There was no statistical significant difference in the anterior capsule compared with the control group. However, the sound speed of the posterior capsule was significantly greater compared with the control group after prolonged immobilization.

  7. Pollen grain surface in Vaccinium myrtillus as seen in scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    Józef Kocoń

    2014-01-01

    Full Text Available Pollen grain surface of Vaccinium myrtillus L. was analyzed by scanning electron microscopy. Pollen grains remain in tetrahedral tetrads. Grain surface is verrucose, consisting of thick, irregularly shaped muri, surrounding small, round or oval lumina. The surface of the muri is fissured, and minute papillae can also be noted.

  8. Carbon induced metal dusting of iron-nickel-chromium alloy surfaces : a scanning auger microscopy study

    NARCIS (Netherlands)

    Palasantzas, G; DeHosson, JTM

    2004-01-01

    In this work, we present an investigation on metal dusting of iron-nickel-chromium (Fe-Ni-Cr) alloy surfaces using scanning auger microscopy. It is shown that the formation of surface Cr-oxide and the surface finish condition can strongly influence and interrupt this catastrophic phenomenon. The

  9. Second-Harmonic Generation Scanning Microscopy on Domains in Al Surfaces

    DEFF Research Database (Denmark)

    Pedersen, Kjeld; Bozhevolnyi, Sergey I.

    1999-01-01

    Scanning optical second-harmonic generation microscopy has been used to investigate domains in the surface of polycrystaline Al. Strong contrast among the crystalline grains is obtained due to variations in their crystallographic orientations and thus also nonlinear response. The origin of the co...

  10. THALLUS SURFACES IN COCCOCARPIACEAE AND PANNARIACEAE (LICHENIZED ASCOMYCETES) VIEWED WITH SCANNING ELECTRON-MICROSCOPY

    NARCIS (Netherlands)

    LUMBSCH, HT; KOTHE, HW

    1992-01-01

    The thallus surfaces of species belonging to the Coccocarpiaceae and Pannariaceae were studied using scanning electron microscopy (SEM). A pored epicortex was shown in Coccocarpia ssp., Degelia gayana and D. plumbea. In the other species studied no definite pores were found. The probable systematic

  11. Cold-induced imbibition damage of lettuce embryos: A study using cryo-scanning electron microscopy

    NARCIS (Netherlands)

    Nijsse, J.; Walther, P.; Hoekstra, F.

    2004-01-01

    The impact of rehydration on a multicellular organism was studied in lettuce (Lactuca sativa L.) embryos, using cryo-scanning electron microscopy (cryo-SEM). Naked embryos were sensitive to imbibitional stress, whereas embryos with an intact, thick-walled endosperm were not. Imbibitional injury to

  12. Scanning Tunneling Microscopy Studies of Topological Insulators Grown by Molecular Beam Epitaxy

    Directory of Open Access Journals (Sweden)

    Xue Qikun

    2012-03-01

    Full Text Available We summarize our recent scanning tunneling microscopy (STM study of topological insulator thin films grown by molecular beam epitaxy (MBE, which includes the observation of electron standing waves on topological insulator surface and the Landau quantization of topological surface states. The work has provided valuable information to the understanding of intriguing properties of topological insulators, as predicted by theory.

  13. Combining optical tweezers and scanning probe microscopy to study DNA-protein interactions

    NARCIS (Netherlands)

    Huisstede, Jurgen H G; Subramaniam, Vinod; Bennink, Martin L

    We present the first results obtained with a new instrument designed and built to study DNA-protein interactions at the single molecule level. This microscope combines optical tweezers with scanning probe microscopy and allows us to locate DNA-binding proteins on a single suspended DNA molecule. A

  14. Near-Field Scanning Optical Microscopy of Single Fluorescent Dendritic Molecules

    NARCIS (Netherlands)

    Veerman, J.A.; Levi, S.; van Veggel, F.C.J.M.; Reinhoudt, David; van Hulst, N.F.

    1999-01-01

    Individual dendritic molecules adsorbed o­n glass containing a single fluorescent rhodamine B core have been observed with near-field scanning optical microscopy (NSOM); height and fluorescence images were obtained simultaneously. The dendritic assemblies can be discriminated from free fluorescent

  15. Adsorption of Cu phthalocyanine on Pt modified Ge(001): A scanning tunneling microscopy study

    NARCIS (Netherlands)

    Saedi, A.; Berkelaar, Robin P.; Kumar, Avijit; Poelsema, Bene; Zandvliet, Henricus J.W.

    2010-01-01

    The adsorption configurations of copper phthalocyanine (CuPc) molecules on platinum-modified Ge(001) have been studied using scanning tunneling microscopy. After deposition at room temperature and cooling down to 77 K the CuPc molecules are still dynamic. However, after annealing at 550±50 K, the

  16. PROBING STRESS EFFECTS IN SINGLE CRYSTAL ORGANIC TRANSISTORS BY SCANNING KELVIN PROBE MICROSCOPY

    Energy Technology Data Exchange (ETDEWEB)

    Teague, L

    2010-06-11

    We report scanning Kelvin probe microscopy (SKPM) of single crystal difluoro bis(triethylsilylethynyl) anthradithiophene (diF-TESADT) organic transistors. SKPM provides a direct measurement of the intrinsic charge transport in the crystals independent of contact effects and reveals that degradation of device performance occurs over a time period of minutes as the diF-TESADT crystal becomes charged.

  17. Controlled light-exposure microscopy reduces photobleaching and phototoxicity in fluorescence live-cell imaging.

    NARCIS (Netherlands)

    Hoebe, R.A.; van Oven, C.H.; Gadella, Th.W.J.; Dhonukshe, P.B.; van Noorden, C.J.F.; Manders, E.M.M.

    2007-01-01

    Fluorescence microscopy of living cells enables visualization of the dynamics and interactions of intracellular molecules. However, fluorescence live-cell imaging is limited by photobleaching and phototoxicity induced by the excitation light. Here we describe controlled light-exposure microscopy

  18. Controlled light-exposure microscopy reduces photobleaching and phototoxicity in fluorescence live-cell imaging

    NARCIS (Netherlands)

    Hoebe, R. A.; van Oven, C. H.; Gadella, T. W. J.; Dhonukshe, P. B.; van Noorden, C. J. F.; Manders, E. M. M.

    2007-01-01

    Fluorescence microscopy of living cells enables visualization of the dynamics and interactions of intracellular molecules. However, fluorescence live-cell imaging is limited by photobleaching and phototoxicity induced by the excitation light. Here we describe controlled light-exposure microscopy (

  19. High-contrast en bloc staining of neuronal tissue for field emission scanning electron microscopy.

    Science.gov (United States)

    Tapia, Juan Carlos; Kasthuri, Narayanan; Hayworth, Kenneth J; Schalek, Richard; Lichtman, Jeff W; Smith, Stephen J; Buchanan, JoAnn

    2012-01-12

    Conventional heavy metal poststaining methods on thin sections lend contrast but often cause contamination. To avoid this problem, we tested several en bloc staining techniques to contrast tissue in serial sections mounted on solid substrates for examination by field emission scanning electron microscopy (FESEM). Because FESEM section imaging requires that specimens have higher contrast and greater electrical conductivity than transmission electron microscopy (TEM) samples, our technique uses osmium impregnation (OTO) to make the samples conductive while heavily staining membranes for segmentation studies. Combining this step with other classic heavy metal en bloc stains, including uranyl acetate (UA), lead aspartate, copper sulfate and lead citrate, produced clean, highly contrasted TEM and scanning electron microscopy (SEM) samples of insect, fish and mammalian nervous systems. This protocol takes 7-15 d to prepare resin-embedded tissue, cut sections and produce serial section images.

  20. 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.

  1. Growth of Pd-Filled Carbon Nanotubes on the Tip of Scanning Probe Microscopy

    Directory of Open Access Journals (Sweden)

    Tomokazu Sakamoto

    2009-01-01

    Full Text Available We have synthesized Pd-filled carbon nanotubes (CNTs oriented perpendicular to Si substrates using a microwave plasma-enhanced chemical vapor deposition (MPECVD for the application of scanning probe microscopy (SPM tip. Prior to the CVD growth, Al thin film (10 nm was coated on the substrate as a buffer layer followed by depositing a 5∼40 nm-thick Pd film as a catalyst. The diameter and areal density of CNTs grown depend largely on the initial Pd thickness. Scanning electron microscopy (SEM and transmission electron microscopy (TEM images clearly show that Pd is successfully encapsulated into the CNTs, probably leading to higher conductivity. Using optimum growth conditions, Pd-filled CNTs are successfully grown on the apex of the conventional SPM cantilever.

  2. Parallel-multiplexed excitation light-sheet microscopy (Conference Presentation)

    Science.gov (United States)

    Xu, Dongli; Zhou, Weibin; Peng, Leilei

    2017-02-01

    Laser scanning light-sheet imaging allows fast 3D image of live samples with minimal bleach and photo-toxicity. Existing light-sheet techniques have very limited capability in multi-label imaging. Hyper-spectral imaging is needed to unmix commonly used fluorescent proteins with large spectral overlaps. However, the challenge is how to perform hyper-spectral imaging without sacrificing the image speed, so that dynamic and complex events can be captured live. We report wavelength-encoded structured illumination light sheet imaging (λ-SIM light-sheet), a novel light-sheet technique that is capable of parallel multiplexing in multiple excitation-emission spectral channels. λ-SIM light-sheet captures images of all possible excitation-emission channels in true parallel. It does not require compromising the imaging speed and is capable of distinguish labels by both excitation and emission spectral properties, which facilitates unmixing fluorescent labels with overlapping spectral peaks and will allow more labels being used together. We build a hyper-spectral light-sheet microscope that combined λ-SIM with an extended field of view through Bessel beam illumination. The system has a 250-micron-wide field of view and confocal level resolution. The microscope, equipped with multiple laser lines and an unlimited number of spectral channels, can potentially image up to 6 commonly used fluorescent proteins from blue to red. Results from in vivo imaging of live zebrafish embryos expressing various genetic markers and sensors will be shown. Hyper-spectral images from λ-SIM light-sheet will allow multiplexed and dynamic functional imaging in live tissue and animals.

  3. Light sheet fluorescence microscopy (LSFM): past, present and future.

    Science.gov (United States)

    Lim, John; Lee, Hwee Kuan; Yu, Weimiao; Ahmed, Sohail

    2014-10-07

    Light sheet fluorescence microscopy (LSFM) has emerged as an important imaging modality to follow biology in live 3D samples over time with reduced phototoxicity and photobleaching. In particular, LSFM has been instrumental in revealing the detail of early embryonic development of Zebrafish, Drosophila, and C. elegans. Open access projects, DIY-SPIM, OpenSPIM, and OpenSPIN, now allow LSFM to be set-up easily and at low cost. The aim of this paper is to facilitate the set-up and use of LSFM by reviewing and comparing open access projects, image processing tools and future challenges.

  4. Robert Feulgen Prize Lecture 1995. Electronic light microscopy: present capabilities and future prospects.

    Science.gov (United States)

    Shotton, D M

    1995-08-01

    Electronic light microscopy involves the combination of microscopic techniques with electronic imaging and digital image processing, resulting in dramatic improvements in image quality and ease of quantitative analysis. In this review, after a brief definition of digital images and a discussion of the sampling requirements for the accurate digital recording of optical images, I discuss the three most important imaging modalities in electronic light microscopy--video-enhanced contrast microscopy, digital fluorescence microscopy and confocal scanning microscopy--considering their capabilities, their applications, and recent developments that will increase their potential. Video-enhanced contrast microscopy permits the clear visualisation and real-time dynamic recording of minute objects such as microtubules, vesicles and colloidal gold particles, an order of magnitude smaller than the resolution limit of the light microscope. It has revolutionised the study of cellular motility, and permits the quantitative tracking of organelles and gold-labelled membrane bound proteins. In combination with the technique of optical trapping (optical tweezers), it permits exquisitely sensitive force and distance measurements to be made on motor proteins. Digital fluorescence microscopy enables low-light-level imaging of fluorescently labelled specimens. Recent progress has involved improvements in cameras, fluorescent probes and fluorescent filter sets, particularly multiple bandpass dichroic mirrors, and developments in multiparameter imaging, which is becoming particularly important for in situ hybridisation studies and automated image cytometry, fluorescence ratio imaging, and time-resolved fluorescence. As software improves and small computers become more powerful, computational techniques for out-of-focus blur deconvolution and image restoration are becoming increasingly important. Confocal microscopy permits convenient, high-resolution, non-invasive, blur-free optical

  5. 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.

  6. Topography and refractometry of nanostructures using spatial light interference microscopy.

    Science.gov (United States)

    Wang, Zhuo; Chun, Ik Su; Li, Xiuling; Ong, Zhun-Yong; Pop, Eric; Millet, Larry; Gillette, Martha; Popescu, Gabriel

    2010-01-15

    Spatial light interference microscopy (SLIM) is a novel method developed in our laboratory that provides quantitative phase images of transparent structures with a 0.3 nm spatial and 0.03 nm temporal accuracy owing to the white light illumination and its common path interferometric geometry. We exploit these features and demonstrate SLIM's ability to perform topography at a single atomic layer in graphene. Further, using a decoupling procedure that we developed for cylindrical structures, we extract the axially averaged refractive index of semiconductor nanotubes and a neurite of a live hippocampal neuron in culture. We believe that this study will set the basis for novel high-throughput topography and refractometry of man-made and biological nanostructures.

  7. Using Light Sheet Fluorescence Microscopy to Image Zebrafish Eye Development.

    Science.gov (United States)

    Icha, Jaroslav; Schmied, Christopher; Sidhaye, Jaydeep; Tomancak, Pavel; Preibisch, Stephan; Norden, Caren

    2016-04-10

    Light sheet fluorescence microscopy (LSFM) is gaining more and more popularity as a method to image embryonic development. The main advantages of LSFM compared to confocal systems are its low phototoxicity, gentle mounting strategies, fast acquisition with high signal to noise ratio and the possibility of imaging samples from various angles (views) for long periods of time. Imaging from multiple views unleashes the full potential of LSFM, but at the same time it can create terabyte-sized datasets. Processing such datasets is the biggest challenge of using LSFM. In this protocol we outline some solutions to this problem. Until recently, LSFM was mostly performed in laboratories that had the expertise to build and operate their own light sheet microscopes. However, in the last three years several commercial implementations of LSFM became available, which are multipurpose and easy to use for any developmental biologist. This article is primarily directed to those researchers, who are not LSFM technology developers, but want to employ LSFM as a tool to answer specific developmental biology questions. Here, we use imaging of zebrafish eye development as an example to introduce the reader to LSFM technology and we demonstrate applications of LSFM across multiple spatial and temporal scales. This article describes a complete experimental protocol starting with the mounting of zebrafish embryos for LSFM. We then outline the options for imaging using the commercially available light sheet microscope. Importantly, we also explain a pipeline for subsequent registration and fusion of multiview datasets using an open source solution implemented as a Fiji plugin. While this protocol focuses on imaging the developing zebrafish eye and processing data from a particular imaging setup, most of the insights and troubleshooting suggestions presented here are of general use and the protocol can be adapted to a variety of light sheet microscopy experiments.

  8. Plasma-deposited fluorocarbon films: insulation material for microelectrodes and combined atomic force microscopy-scanning electrochemical microscopy probes.

    Science.gov (United States)

    Wiedemair, Justyna; Balu, Balamurali; Moon, Jong-Seok; Hess, Dennis W; Mizaikoff, Boris; Kranz, Christine

    2008-07-01

    Pinhole-free insulation of micro- and nanoelectrodes is the key to successful microelectrochemical experiments performed in vivo or in combination with scanning probe experiments. A novel insulation technique based on fluorocarbon insulation layers deposited from pentafluoroethane (PFE, CF3CHF2) plasmas is presented as a promising electrical insulation approach for microelectrodes and combined atomic force microscopy-scanning electrochemical microscopy (AFM-SECM) probes. The deposition allows reproducible and uniform coating, which is essential for many analytical applications of micro- and nanoelectrodes such as, e.g., in vivo experiments and SECM experiments. Disk-shaped microelectrodes and frame-shaped AFM tip-integrated electrodes have been fabricated by postinsulation focused ion beam (FIB) milling. The thin insulation layer for combined AFM-SECM probes renders this fabrication technique particularly useful for submicro insulation providing radius ratios of the outer insulation versus the disk electrode (RG values) suitable for SECM experiments. Characterization of PFE-insulated AFM-SECM probes will be presented along with combined AFM-SECM approach curves and imaging.

  9. Wide-field imaging through scattering media by scattered light fluorescence microscopy

    Science.gov (United States)

    Zhou, Yulan; Li, Xun

    2017-08-01

    To obtain images through scattering media, scattered light fluorescence (SLF) microscopy that utilizes the optical memory effect has been developed. However, the small field of view (FOV) of SLF microscopy limits its application. In this paper, we have introduced a re-modulation method to achieve wide-field imaging through scattering media by SLF microscopy. In the re-modulation method, to raster scan the focus across the object plane, the incident wavefront is re-modulated via a spatial light modulator (SLM) in the updated phase compensation calculated using the optimized iterative algorithm. Compared with the conventional optical memory effect method, the re-modulation method can greatly increase the FOV of a SLF microscope. With the phase compensation theoretically calculated, the process of updating the phase compensation of a high speed SLM is fast. The re-modulation method does not increase the imaging time. The re-modulation method is, therefore, expected to make SLF microscopy have much wider applications in biology, medicine and physiology.

  10. Light sheet microscopy and live imaging of plants.

    Science.gov (United States)

    Berthet, Béatrice; Maizel, Alexis

    2016-08-01

    Light sheet fluorescence microscopy (LSFM) is increasingly used to investigate biological processes in animals as well as in plants. LSFM achieves optical sectioning by the selective illumination of a single plane of the sample with a sheet of laser light while simultaneously recording emitted fluorescence orthogonally to the illumination plane. A 3D image of the sample can then be generated with a temporal resolution ranging from seconds to several days, and at scales ranging from subcellular to whole organ. By design, LSFM provides fast imaging, and low phototoxicity, two key criteria for live imaging under physiological conditions. Despite its potential, LSFM remains underutilized in plant biology. This review aims to highlight challenges of live imaging in plants, to describe key steps in using LSFM on live plant samples and finally at providing an overview of published examples of applications of LSFM in plants. © 2016 The Authors Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.

  11. Lateral spatial resolution of thermal lens microscopy during continuous scanning for nonstaining biofilm imaging

    Science.gov (United States)

    Rossteuscher, T. T. J.; Hibara, A.; Mawatari, K.; Kitamori, T.

    2009-05-01

    The possible application of continuous scanning thermal lens microscopy (TLM) as alternative online biofilm observation method is studied. As biofilm is a heterogeneous sample, the influence of spatially limited thermal flow at the sample heterogeneities and the biofilm-environment border has to be considered. The influence of the edges on the lateral resolution with respect to scanning velocity during continuous scanning TLM was therefore evaluated. Lateral scanning experiments on 100 nm thin gold stripes showed that the maximum scan speed can be predicted from a time constant of a lock-in amplifier and the beamwidth. Since three-dimensional mapping is needed to fully characterize the biofilm structure, depth scanning experiments with stained 4 μm thick polystyrene samples with the coaxial TLM setup were evaluated for signal width at full width at half maximum. Thus, a minimum step width for depth scanning of 10 μm for observation has been acquired. A three-dimensional image of unstained biofilm grown in a flow chamber was acquired using continuous scanning TLM.

  12. The Use Of Scanning Probe Microscopy To Investigate Crystal-Fluid Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Orme, C A; Giocondi, J L

    2007-04-16

    Over the past decade there has been a natural drive to extend the investigation of dynamic surfaces in fluid environments to higher resolution characterization tools. Various aspects of solution crystal growth have been directly visualized for the first time. These include island nucleation and growth using transmission electron microscopy and scanning tunneling microscopy; elemental step motion using scanning probe microscopy; and the time evolution of interfacial atomic structure using various diffraction techniques. In this lecture we will discuss the use of one such in situ method, scanning probe microscopy, as a means of measuring surface dynamics during crystal growth and dissolution. We will cover both practical aspects of imaging such as environmental control, fluid flow, and electrochemical manipulation, as well as the types of physical measurements that can be made. Measurements such as step motion, critical lengths, nucleation density, and step fluctuations, will be put in context of the information they provide about mechanistic processes at surfaces using examples from metal and mineral crystal growth.

  13. Characterization of tip size and geometry of the pipettes used in scanning ion conductance microscopy.

    Science.gov (United States)

    Tognoni, Elisabetta; Baschieri, Paolo; Ascoli, Cesare; Pellegrini, Monica; Pellegrino, Mario

    2016-04-01

    Scanning ion-conductance microscopy (SICM) belongs to the family of scanning-probe microscopies. The spatial resolution of these techniques is limited by the size of the probe. In SICM the probe is a pipette, obtained by heating and pulling a glass capillary tubing. The size of the pipette tip is therefore an important parameter in SICM experiments. However, the characterization of the tip is not a consolidated routine in SICM experimental practice. In addition, potential and limitations of the different methods available for this characterization may not be known to all users. We present an overview of different methods for characterizing size and geometry of the pipette tip, with the aim of collecting and facilitating the use of several pieces of information appeared in the literature in a wide interval of time under different disciplines. In fact, several methods that have been developed for pipettes used in cell physiology can be also fruitfully employed in the characterization of the SICM probes. The overview includes imaging techniques, such as scanning electron microscopy and atomic Force microscopy, and indirect methods, which measure some physical parameter related to the size of the pipette. Examples of these parameters are the electrical resistance of the pipette filled with a saline solution and the surface tension at the pipette tip. We discuss advantages and drawbacks of the methods, which may be helpful in answering a wide range of experimental questions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Scanning probe microscopy: instrumentation and applications on thin films and magnetic multilayers.

    Science.gov (United States)

    Karoutsos, Vagelis

    2009-12-01

    In this article we present a review on instrumentation and the modes of operation of a scanning probe microscope. In detail, we review the main techniques of Scanning Probe Microscopy (SPM), which are Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM), focusing our attention on the latter one. The AFM instrument provides information on the roughness and grain size of thin films. As an example we review recent results on two metallic thin film systems: thin Ag films deposited on glass, and Ni/Pt compositionally modulated multilayers deposited on glass, Si, and polyimide substrates. To show the validity of the grain size measurements, we compare the data with the ones resulting from X-ray diffraction (XRD) measurements. We show that the AFM results are reliable for grain diameters as small as 14 nm, which is approximately comparable to the tip radius. Finally, we deal with Magnetic Force Microscopy (MFM) results on Co/Pt and Co/Au multilayers. We observe perpendicularly magnetized domains. The domain configurations are correlated to the magnetization hysteresis curves.

  15. Invited Review Article: Advanced light microscopy for biological space research

    Science.gov (United States)

    De Vos, Winnok H.; Beghuin, Didier; Schwarz, Christian J.; Jones, David B.; van Loon, Jack J. W. A.; Bereiter-Hahn, Juergen; Stelzer, Ernst H. K.

    2014-10-01

    As commercial space flights have become feasible and long-term extraterrestrial missions are planned, it is imperative that the impact of space travel and the space environment on human physiology be thoroughly characterized. Scrutinizing the effects of potentially detrimental factors such as ionizing radiation and microgravity at the cellular and tissue level demands adequate visualization technology. Advanced light microscopy (ALM) is the leading tool for non-destructive structural and functional investigation of static as well as dynamic biological systems. In recent years, technological developments and advances in photochemistry and genetic engineering have boosted all aspects of resolution, readout and throughput, rendering ALM ideally suited for biological space research. While various microscopy-based studies have addressed cellular response to space-related environmental stressors, biological endpoints have typically been determined only after the mission, leaving an experimental gap that is prone to bias results. An on-board, real-time microscopical monitoring device can bridge this gap. Breadboards and even fully operational microscope setups have been conceived, but they need to be rendered more compact and versatile. Most importantly, they must allow addressing the impact of gravity, or the lack thereof, on physiologically relevant biological systems in space and in ground-based simulations. In order to delineate the essential functionalities for such a system, we have reviewed the pending questions in space science, the relevant biological model systems, and the state-of-the art in ALM. Based on a rigorous trade-off, in which we recognize the relevance of multi-cellular systems and the cellular microenvironment, we propose a compact, but flexible concept for space-related cell biological research that is based on light sheet microscopy.

  16. Invited Review Article: Advanced light microscopy for biological space research

    Energy Technology Data Exchange (ETDEWEB)

    De Vos, Winnok H., E-mail: winnok.devos@uantwerpen.be [Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerp (Belgium); Cell Systems and Imaging Research Group, Department of Molecular Biotechnology, Ghent University, Ghent (Belgium); Beghuin, Didier [Lambda-X, Nivelles (Belgium); Schwarz, Christian J. [European Space Agency (ESA), ESTEC, TEC-MMG, Noordwijk (Netherlands); Jones, David B. [Institute for Experimental Orthopaedics and Biomechanics, Philipps University, Marburg (Germany); Loon, Jack J. W. A. van [Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center and Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, Amsterdam (Netherlands); Bereiter-Hahn, Juergen; Stelzer, Ernst H. K. [Physical Biology, BMLS (FB15, IZN), Goethe University, Frankfurt am Main (Germany)

    2014-10-15

    As commercial space flights have become feasible and long-term extraterrestrial missions are planned, it is imperative that the impact of space travel and the space environment on human physiology be thoroughly characterized. Scrutinizing the effects of potentially detrimental factors such as ionizing radiation and microgravity at the cellular and tissue level demands adequate visualization technology. Advanced light microscopy (ALM) is the leading tool for non-destructive structural and functional investigation of static as well as dynamic biological systems. In recent years, technological developments and advances in photochemistry and genetic engineering have boosted all aspects of resolution, readout and throughput, rendering ALM ideally suited for biological space research. While various microscopy-based studies have addressed cellular response to space-related environmental stressors, biological endpoints have typically been determined only after the mission, leaving an experimental gap that is prone to bias results. An on-board, real-time microscopical monitoring device can bridge this gap. Breadboards and even fully operational microscope setups have been conceived, but they need to be rendered more compact and versatile. Most importantly, they must allow addressing the impact of gravity, or the lack thereof, on physiologically relevant biological systems in space and in ground-based simulations. In order to delineate the essential functionalities for such a system, we have reviewed the pending questions in space science, the relevant biological model systems, and the state-of-the art in ALM. Based on a rigorous trade-off, in which we recognize the relevance of multi-cellular systems and the cellular microenvironment, we propose a compact, but flexible concept for space-related cell biological research that is based on light sheet microscopy.

  17. Combined nanoprobes for scanning probe microscopy: laser technology for processing and testing

    Science.gov (United States)

    Veiko, V. P.; Golubok, A. O.; Zuong, Z.; Varkentina, N. V.; Yakovlev, E. B.

    2008-02-01

    Scanning probe microscopy (SPM) is a high spatial resolution method of surface topography visualization and measurement of its local properties. The detecting of interaction arising between the sharp solid-state probe and the sample surface is the foundation of SPM. In dependence from nature of this interaction the scanning tunnel microscopy (STM), scanning force microscopy (SFM), scanning near field optical microscopy (SNOM), etc. are distinguished. The spatial resolution of all types of probe microscopy determins both sharpness of increasing of interaction between a probe and a sample at their approach, and shape and size of a top of a solid-state probe. So, the progress in SPM information capabilities is highly depends from probe properties and first of all from properly fabricated aperture size. Fabrication procedures are rather complicated because of nanometric scale size of aperture and hard requirements to reproducibility and need to be improved. The way how to do it is involving of feed-back in a processing procedure-results in two types of feedback for the process of drawing-out has been suggested, tested and installed into the technological set-up. Different probes have been fabricated by laser-assisted drawing-out during this work: SNOM types from optical fibers, micropipettes from quartz glass capillaries, micropipettes with microwires inside and with metallic covers outside. Some examples of application of above mentioned combined probes for cell membrane technology are described. Most important from them are topographical studying of cells and bacteria in living condition (in liquid) and studying of the mechanical properties of cell (rigidity of cell membrane) using the nanopipette as a tip of a force sensor. Also measurement of ion current that runs through cell membrane during its metabolic process using the nanopipette as well as in the well-known patch-clamp method have been done.

  18. The use of scanning ion conductance microscopy to image A6 cells.

    Science.gov (United States)

    Gorelik, Julia; Zhang, Yanjun; Shevchuk, Andrew I; Frolenkov, Gregory I; Sánchez, Daniel; Lab, Max J; Vodyanoy, Igor; Edwards, Christopher R W; Klenerman, David; Korchev, Yuri E

    2004-03-31

    Continuous high spatial resolution observations of living A6 cells would greatly aid the elucidation of the relationship between structure and function and facilitate the study of major physiological processes such as the mechanism of action of aldosterone. Unfortunately, observing the micro-structural and functional changes in the membrane of living cells is still a formidable challenge for a microscopist. Scanning ion conductance microscopy (SICM), which uses a glass nanopipette as a sensitive probe, has been shown to be suitable for imaging non-conducting surfaces bathed in electrolytes. A specialized version of this microscopy has been developed by our group and has been applied to image live cells at high-resolution for the first time. This method can also be used in conjunction with patch clamping to study both anatomy and function and identify ion channels in single cells. This new microscopy provides high-resolution images of living renal cells which are comparable with those obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Continuous 24h observations under normal physiological conditions showed how A6 kidney epithelial cells changed their height, volume, and reshaped their borders. The changes in cell area correlated with the density of microvilli on the surface. Surface microvilli density ranged from 0.5 microm(-2) for extended cells to 2.5 microm(2) for shrunk cells. Patch clamping of individual cells enabled anatomy and function to be correlated. Scanning ion conductance microscopy provides unique information about living cells that helps to understand cellular function. It has the potential to become a powerful tool for research on living renal cells.

  19. Image scanning fluorescence emission difference microscopy based on a detector array.

    Science.gov (United States)

    Li, Y; Liu, S; Liu, D; Sun, S; Kuang, C; Ding, Z; Liu, X

    2017-06-01

    We propose a novel imaging method that enables the enhancement of three-dimensional resolution of confocal microscopy significantly and achieve experimentally a new fluorescence emission difference method for the first time, based on the parallel detection with a detector array. Following the principles of photon reassignment in image scanning microscopy, images captured by the detector array were arranged. And by selecting appropriate reassign patterns, the imaging result with enhanced resolution can be achieved with the method of fluorescence emission difference. Two specific methods are proposed in this paper, showing that the difference between an image scanning microscopy image and a confocal image will achieve an improvement of transverse resolution by approximately 43% compared with that in confocal microscopy, and the axial resolution can also be enhanced by at least 22% experimentally and 35% theoretically. Moreover, the methods presented in this paper can improve the lateral resolution by around 10% than fluorescence emission difference and 15% than Airyscan. The mechanism of our methods is verified by numerical simulations and experimental results, and it has significant potential in biomedical applications. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  20. Imaging metazoan nuclear pore complexes by field emission scanning electron microscopy.

    Science.gov (United States)

    Fichtman, Boris; Shaulov, Lihi; Harel, Amnon

    2014-01-01

    High resolution three-dimensional surface images of nuclear pore complexes (NPCs) can be obtained by field emission scanning electron microscopy. We present a short retrospective view starting from the early roots of microscopy, through the discovery of the cell nucleus and the development of some modern techniques for sample preparation and imaging. Detailed protocols are presented for assembling anchored nuclei in a Xenopus cell-free reconstitution system and for the exposure of the nuclear surface in mammalian cell nuclei. Immunogold labeling of metazoan NPCs and a promising new technique for delicate coating with iridium are also discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Line scan--structured illumination microscopy super-resolution imaging in thick fluorescent samples.

    Science.gov (United States)

    Mandula, Ondrej; Kielhorn, Martin; Wicker, Kai; Krampert, Gerhard; Kleppe, Ingo; Heintzmann, Rainer

    2012-10-22

    Structured illumination microscopy in thick fluorescent samples is a challenging task. The out-of-focus fluorescence background deteriorates the illumination pattern and the reconstructed images suffer from influence of noise. We present a combination of structured illumination microscopy with line scanning. This technique reduces the out-of-focus fluorescence background, which improves the modulation and the quality of the illumination pattern and therefore facilitates the reconstruction. We present super-resolution, optically sectioned images of a thick fluorescent sample, revealing details of the specimen's inner structure.

  2. Optical microscope illumination analysis using through-focus scanning optical microscopy.

    Science.gov (United States)

    Attota, Ravi Kiran; Park, Haesung

    2017-06-15

    Misalignment of the aperture diaphragm present in optical microscopes results in angular illumination asymmetry (ANILAS) at the sample plane. Here we show that through-focus propagation of ANILAS results in a lateral image shift with a focus position. This could lead to substantial errors in quantitative results for optical methods that use through-focus images such as three-dimensional nanoparticle tracking, confocal microscopy, and through-focus scanning optical microscopy (TSOM). A correlation exists between ANILAS and the slant in TSOM images. Hence, the slant in the TSOM image can be used to detect, analyze, and rectify the presence of ANILAS.

  3. Application of scanning force and near field microscopies to the characterization of minimally adhesive polymer surfaces.

    Science.gov (United States)

    Akhremitchev, Boris B; Bemis, Jason E; al-Maawali, Sabah; Sun, Yujie; Stebounova, Larissa; Walker, Gilbert C

    2003-04-01

    This mini-review reports efforts to develop new scanning probe microscopies to characterize the function and aging of textured, minimally adhesive polymer surfaces used for antifouling applications in the marine environment. Novel atomic force and infrared near field microscopy techniques have been used to characterize the polymer surface adhesion and structural properties. These techniques may find promise for characterizing the deposition of the extracellular matrix of organisms as well as aging of the polymer coating itself. The reported work is part of a larger effort to reduce biofouling on ships' hulls through the development and use of improved coating materials.

  4. In Situ Scanning Probe Microscopy and New Perspectives in Analytical Chemistry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Zhang, Jingdong; Chi, Qijin

    1999-01-01

    for molecular- and mesoscopic-scale analytical chemistry, are then reviewed. They are illustrated by metallic electro-crystallisation and -dissolution, and in situ STM spectroscopy of large redox molecules. The biophysically oriented analytical options of in situ atomic force microscopy, and analytical chemical......The resolution of scanning probe microscopies is unpresedented but the techniques are fraught with limitations as analytical tools. These limitations and their relationship to the physical mechanisms of image contrast are first discussed. Some new options based on in situ STM, which hold prospects...

  5. Development of an add-on kit for scanning confocal microscopy (Conference Presentation)

    Science.gov (United States)

    Guo, Kaikai; Zheng, Guoan

    2017-03-01

    Scanning confocal microscopy is a standard choice for many fluorescence imaging applications in basic biomedical research. It is able to produce optically sectioned images and provide acquisition versatility to address many samples and application demands. However, scanning a focused point across the specimen limits the speed of image acquisition. As a result, scanning confocal microscope only works well with stationary samples. Researchers have performed parallel confocal scanning using digital-micromirror-device (DMD), which was used to project a scanning multi-point pattern across the sample. The DMD based parallel confocal systems increase the imaging speed while maintaining the optical sectioning ability. In this paper, we report the development of an add-on kit for high-speed and low-cost confocal microscopy. By adapting this add-on kit to an existing regular microscope, one can convert it into a confocal microscope without significant hardware modifications. Compared with current DMD-based implementations, the reported approach is able to recover multiple layers along the z axis simultaneously. It may find applications in wafer inspection and 3D metrology of semiconductor circuit. The dissemination of the proposed add-on kit under $1000 budget could also lead to new types of experimental designs for biological research labs, e.g., cytology analysis in cell culture experiments, genetic studies on multicellular organisms, pharmaceutical drug profiling, RNA interference studies, investigation of microbial communities in environmental systems, and etc.

  6. Use of scanning electron microscopy in the speciation of Gliocephalotrichum spp. in rambutan (Nephelium lappaceum L.)

    Science.gov (United States)

    Rambutan is a tropical tree fruit crop native to Malaysia. Worldwide, fruit rot is a limiting factor for fruit quality. In 2011, fruit rot was observed on rambutan at the USDA-ARS Tropical Agricultural Station in Mayaguez, Puerto Rico, and was attributed to Gliocephalotrichum spp. Light microscopy (...

  7. Observation of mesenteric microcirculatory disturbance in rat by laser oblique scanning optical microscopy

    Science.gov (United States)

    Ding, Yichen; Zhang, Yu; Peng, Tong; Lu, Yiqing; Jin, Dayong; Ren, Qiushi; Liu, Yuying; Han, Jingyan; Xi, Peng

    2013-05-01

    Ischemia-reperfusion (I/R) injury model has been widely applied to the study of microcirculation disturbance. In this work, we used laser oblique scanning optical microscopy (LOSOM) to observe the microcirculation system in the mesentery of rat model. Utilizing a localized point-scanning detection scheme, high-contrast images of leukocytes were obtained. The extended detection capability facilitated both the automatic in vivo cell counting and the accurate measurement of the rolling velocity of leukocytes. Statistical analysis of the different treatment groups suggested that the distinction between I/R and sham groups with time lapse is significant.

  8. Investigation of optical nanostructures for photovoltaics with near-field scanning microscopy; Untersuchung optischer Nanostrukturen fuer die Photovoltaik mit Nahfeldmikroskopie

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Thomas

    2011-09-26

    Textured and rough surfaces are known to increase light trapping in solar cells significantly. The development and optimization of these nano-structures is essential to improve the energy conversion efficiency of thin-film solar cells. In the past, first research approaches covered classical and macroscopic investigations, e.g. determining the haze or angularly resolved scattering. These methods do not provide precise explanation for the optical improvement of the devices, because layer thicknesses and structure sizes in thin-film solar cells are smaller than the wavelength of visible light. The impact of local nano-structures and their contribution to the local absorption enhancement is not resolved by macroscopic measurements. In this thesis, near-field scanning optical microscopy is introduced as first near-field investigations of nano-structures for photovoltaics. This provides an insight into local optical effects for relevant surfaces of photovoltaic devices. Investigating the distribution of the electric fields in layer stacks is crucial to understand the absorption in solar cells. Evanescent fields, which occur due to total internal reflection at the interfaces, are measurable by near-field scanning optical microscopy and yield important information about local light trapping. Within the framework of this thesis, correlations between local surface structures and optical near-field effects are shown. In this case structure features of randomly textured surfaces, which optimize local light trapping, are identified. It paves the way to connect microscopic optical effects on the surface with the macroscopic performance of thin-film solar cells. Moreover, the measurement yields a 3D illustration of the electric field distribution over the sample surface. It is an important criterion to prove the results of rigorous diffraction theory. An excellent agreement between experiment and simulation is found. The simulations provide an insight into the material, which is

  9. A platform for time-resolved scanning Kerr microscopy in the near-field.

    Science.gov (United States)

    Keatley, Paul S; Loughran, Thomas H J; Hendry, Euan; Barnes, William L; Hicken, Robert J; Childress, Jeffrey R; Katine, Jordan A

    2017-12-01

    Time-resolved scanning Kerr microscopy (TRSKM) is a powerful technique for the investigation of picosecond magnetization dynamics at sub-micron length scales by means of the magneto-optical Kerr effect (MOKE). The spatial resolution of conventional (focused) Kerr microscopy using a microscope objective lens is determined by the optical diffraction limit so that the nanoscale character of the magnetization dynamics is lost. Here we present a platform to overcome this limitation by means of a near-field TRSKM that incorporates an atomic force microscope (AFM) with optical access to a metallic AFM probe with a nanoscale aperture at its tip. We demonstrate the near-field capability of the instrument through the comparison of time-resolved polar Kerr images of magnetization dynamics within a microscale NiFe rectangle acquired using both near-field and focused TRSKM techniques at a wavelength of 800 nm. The flux-closure domain state of the in-plane equilibrium magnetization provided the maximum possible dynamic polar Kerr contrast across the central domain wall and enabled an assessment of the magneto-optical spatial resolution of each technique. Line profiles extracted from the Kerr images demonstrate that the near-field spatial resolution was enhanced with respect to that of the focused Kerr images. Furthermore, the near-field polar Kerr signal (∼1 mdeg) was more than half that of the focused Kerr signal, despite the potential loss of probe light due to internal reflections within the AFM tip. We have confirmed the near-field operation by exploring the influence of the tip-sample separation and have determined the spatial resolution to be ∼550 nm for an aperture with a sub-wavelength diameter of 400 nm. The spatial resolution of the near-field TRSKM was in good agreement with finite element modeling of the aperture. Large amplitude electric field along regions of the modeled aperture that lie perpendicular to the incident polarization indicate that the aperture can

  10. A platform for time-resolved scanning Kerr microscopy in the near-field

    Science.gov (United States)

    Keatley, Paul S.; Loughran, Thomas H. J.; Hendry, Euan; Barnes, William L.; Hicken, Robert J.; Childress, Jeffrey R.; Katine, Jordan A.

    2017-12-01

    Time-resolved scanning Kerr microscopy (TRSKM) is a powerful technique for the investigation of picosecond magnetization dynamics at sub-micron length scales by means of the magneto-optical Kerr effect (MOKE). The spatial resolution of conventional (focused) Kerr microscopy using a microscope objective lens is determined by the optical diffraction limit so that the nanoscale character of the magnetization dynamics is lost. Here we present a platform to overcome this limitation by means of a near-field TRSKM that incorporates an atomic force microscope (AFM) with optical access to a metallic AFM probe with a nanoscale aperture at its tip. We demonstrate the near-field capability of the instrument through the comparison of time-resolved polar Kerr images of magnetization dynamics within a microscale NiFe rectangle acquired using both near-field and focused TRSKM techniques at a wavelength of 800 nm. The flux-closure domain state of the in-plane equilibrium magnetization provided the maximum possible dynamic polar Kerr contrast across the central domain wall and enabled an assessment of the magneto-optical spatial resolution of each technique. Line profiles extracted from the Kerr images demonstrate that the near-field spatial resolution was enhanced with respect to that of the focused Kerr images. Furthermore, the near-field polar Kerr signal (˜1 mdeg) was more than half that of the focused Kerr signal, despite the potential loss of probe light due to internal reflections within the AFM tip. We have confirmed the near-field operation by exploring the influence of the tip-sample separation and have determined the spatial resolution to be ˜550 nm for an aperture with a sub-wavelength diameter of 400 nm. The spatial resolution of the near-field TRSKM was in good agreement with finite element modeling of the aperture. Large amplitude electric field along regions of the modeled aperture that lie perpendicular to the incident polarization indicate that the aperture can

  11. Practical aspects of single-pass scan Kelvin probe force microscopy

    Science.gov (United States)

    Li, Guangyong; Mao, Bin; Lan, Fei; Liu, Liming

    2012-11-01

    The single-pass scan Kelvin probe force microscopy (KPFM) in ambient condition has a few advantages over the dual-pass lift-up scan KPFM. For example, its spatial resolution is expected to be higher; and its topographical errors caused by electrostatic forces are minimized because electrostatic forces are actively suppressed during the simultaneous topographical and KPFM measurement. Because single-pass scan KPFM in ambient condition is relatively new, it received little attention in the literature so far. In this article, we discuss several major practical aspects of single-pass scan KPFM especially in ambient condition. First, we define the resolution using a point spread function. With this definition, we analyze the relation between the resolution and the scanning parameters such as tip apex radius and tip-surface distance. We further study the accuracy of KPFM based on the point spread function. Then, we analyze the sensitivity of KPFM under different operation modes. Finally, we investigate the crosstalk between the topographical image and the surface potential image and demonstrate the practical ways to minimize the crosstalk. These discussions not only help us to understand the single-pass scan KPFM but also provide practical guidance in using single-pass scan KPFM.

  12. Electron beam confinement and image contrast enhancement in near field emission scanning electron microscopy.

    Science.gov (United States)

    Kirk, T L; De Pietro, L G; Pescia, D; Ramsperger, U

    2009-04-01

    In conventional scanning electron microscopy (SEM), the lateral resolution is limited by the electron beam diameter impinging on the specimen surface. Near field emission scanning electron microscopy (NFESEM) provides a simple means of overcoming this limit; however, the most suitable field emitter remains to be determined. NFESEM has been used in this work to investigate the W (110) surface with single-crystal tungsten tips of (310), (111), and (100)-orientations. The topographic images generated from both the electron intensity variations and the field emission current indicate higher resolution capabilities with decreasing tip work function than with polycrystalline tungsten tips. The confinement of the electron beam transcends the resolution limitations of the geometrical models, which are determined by the minimum beam width.

  13. Field emission scanning electron microscopy of biofilm-growing bacteria involved in nosocomial infections.

    Science.gov (United States)

    Vuotto, Claudia; Donelli, Gianfranco

    2014-01-01

    Scanning electron microscopy (SEM) provides useful information on the shape, size, and localization within the biofilm of single bacteria as well as on the steps of biofilm formation process, on bacterial interactions, and on production of extracellular polymeric substances.When biofilms are constituted by microbial species involved in health care-associated infections, information provided by SEM can be fruitfully used not only for basic researches but also for diagnostic purposes.The protocols currently used in our laboratory for biofilm investigation by SEM are reported here. Particularly, the procedures to fix, dehydrate, and metalize in vitro-developed biofilms or ex vivo clinical specimens colonized by biofilm-growing microorganisms are described as well as the advantages of the observation of these samples by field emission scanning electron microscopy.

  14. Improved depth resolution in video-rate line-scanning multiphoton microscopy using temporal focusing

    Science.gov (United States)

    Tal, Eran; Oron, Dan; Silberberg, Yaron

    2005-07-01

    By introducing spatiotemporal pulse shaping techniques to multiphoton microscopy it is possible to obtain video-rate images with depth resolution similar to point-by-point scanning multiphoton microscopy while mechanically scanning in only one dimension. This is achieved by temporal focusing of the illumination pulse: The pulsed excitation field is compressed as it propagates through the sample, reaching its shortest duration (and highest peak intensity) at the focal plane before stretching again beyond it. This method is applied to produce, in a simple and scalable setup, video-rate two-photon excitation fluorescence images of Drosophila egg chambers with nearly 100,000 effective pixels and 1.5 μm depth resolution.

  15. 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.

  16. Spatiotemporal Rank Filtering Improves Image Quality Compared to Frame Averaging in 2-Photon Laser Scanning Microscopy.

    Directory of Open Access Journals (Sweden)

    Henry Pinkard

    Full Text Available Live imaging of biological specimens using optical microscopy is limited by tradeoffs between spatial and temporal resolution, depth into intact samples, and phototoxicity. Two-photon laser scanning microscopy (2P-LSM, the gold standard for imaging turbid samples in vivo, has conventionally constructed images with sufficient signal-to-noise ratio (SNR generated by sequential raster scans of the focal plane and temporal integration of the collected signals. Here, we describe spatiotemporal rank filtering, a nonlinear alternative to temporal integration, which makes more efficient use of collected photons by selectively reducing noise in 2P-LSM images during acquisition. This results in much higher SNR while preserving image edges and fine details. Practically, this allows for at least a four fold decrease in collection times, a substantial improvement for time-course imaging in biological systems.

  17. Using scanning near-field microscopy to study photo-induced mass motions in azobenzene containing thin films

    Science.gov (United States)

    Vu, A. D.; Fabbri, F.; Desboeufs, N.; Boilot, J.-P.; Gacoin, T.; Lahlil, K.; Lassailly, Y.; Martinelli, L.; Peretti, J.

    2014-10-01

    Scanning near-field optical microscopy (SNOM) is used to study the photo-induced deformation of layered structures containing azobenzene derivatives. This approach is particularly relevant since it allows detecting in real-time, with the same probe the surface topography and the optical field distribution at the nanoscale. The correlation between the local light pattern and the ongoing photo-induced deformation in azobenzene-containing thin films is directly evidenced for different light polarization configurations. This unveils several fundamental photodeformation mechanisms, depending not only on the light field properties, but also on the nature of the material. Controlling the projected electromagnetic field distribution allows inscription of various patterns with a resolution at the diffraction limit, i.e. of a few hundreds of nm. Surface relief patterns with characteristic sizes beyond the diffraction limit can also be produced by using the nearfield probe to locally control the photo-mechanical process. Finally, the photo-mechanical properties of azo-materials are exploited to optically patterned metal/dielectric hybrid structures. Gratings are inscribed this way on thin gold films. The characteristic features (enhancement and localization) of the surface plasmons supported by these noble metal structures are studied by near-field optical microscopy.

  18. Scanning near-field optical microscopy on rough surfaces: Applications in chemistry, biology, and medicine

    OpenAIRE

    Kaupp, Gerd

    2006-01-01

    Shear-force apertureless scanning near-field optical microscopy (SNOM) with very sharp uncoated tapered waveguides relies on the unexpected enhancement of reflection in the shear-force gap. It is the technique for obtaining chemical (materials) contrast in the optical image of “real world” surfaces that are rough and very rough without topographical artifacts, and it is by far less complicated than other SNOM techniques that can only be used for very flat surfaces. The ex...

  19. Evaluation of Yogurt Microstructure Using Confocal Laser Scanning Microscopy and Image Analysis

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke; Ghita, Ovidiu; Whelan, Paul F.

    2015-01-01

    The microstructure of protein networks in yogurts defines important physical properties of the yogurt and hereby partly its quality. Imaging this protein network using confocal scanning laser microscopy (CSLM) has shown good results, and CSLM has become a standard measuring technique for fermented...... to image texture description. Here, CSLM images from a yogurt fermentation study are investigated, where production factors including fat content, protein content, heat treatment, and incubation temperature are varied. The descriptors are evaluated through nearest neighbor classification, variance analysis...

  20. Scanning Auger microscopy analysis of 90 K Y--Ba--Cu--O superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Cota, L.; Morales de la Garza, L.; Hirata, G.; Martinez, L.; Orozco, E.; Carrillo, E.; Mendoza, A.; Albarran, J.L.; Fuentes-Maya, J.; Boldu, J.L.; and others

    1988-05-01

    The oxide superconductor Y--Ba--Cu--O is studied using Auger scanning microscopy. The chemical depth profiles of the samples were obtained. It is concluded that two phases are present in the sample, one corresponding to the standard composition and another that is Ba enriched. The first shows a platelet shape and the second a granular appearence that covers the surface of the sample.

  1. Effect of Autoclave Cycles on Surface Characteristics of S-File Evaluated by Scanning Electron Microscopy

    OpenAIRE

    Razavian, Hamid; Iranmanesh, Pedram; Mojtahedi, Hamid; Nazeri, Rahman

    2015-01-01

    Introduction: Presence of surface defects in endodontic instruments can lead to unwanted complications such as instrument fracture and incomplete preparation of the canal. The current study was conducted to evaluate the effect of autoclave cycles on surface characteristics of S-File by scanning electron microscopy (SEM). Methods and Materials: In this experimental study, 17 brand new S-Files (#30) were used. The surface characteristics of the files were examined in four steps (without autocla...

  2. Pulse Plating on Gold Surfaces Studied by In Situ Scanning Tunneling Microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1994-01-01

    Deposition of bulk copper on thin film gold surfaces is carried out by computer-aided pulse plating. It is demonstrated that the morphology of the copper deposit can be studied by in situ scanning tunnelling microscopy both in potentiostatic experiments and in galvanostatic experiments. Optimized...... procedures for obtaining smooth deposits by pulse plating are explained in terms of a levelling effect. Possible non-faradaic processes observed in measurements with high frequency pulse plating are discussed....

  3. Scanning electron microscopy and calcification in amelogenesis imperfecta in anterior and posterior human teeth

    OpenAIRE

    Sánchez-Quevedo, M.C.; Ceballos, G.; García, J. M.; Rodriguez, I. A.; Gómez de Ferraris, M.E.; Campos, Antonio

    2001-01-01

    Teeth fragments from members of a famil? clinically and genetically diagnosed as having amelogenesis imperfecta were studied by scanning electron microscopy and X-ray microprobe analysis to establish the morphological patterns and the quantitative concentration of calcium in the enamel of anterior (canine, incisor) and posterior (premolar and molar) teeth. The prism patterns in the enamel of teeth from both regions were parallel or irregularly decussate, with ...

  4. Scanning electron microscopy of the egg-shell of the fly synthesiomyia Nudiseta (wulp)

    OpenAIRE

    El Alfy, Nagla Z. [نجلاء زكي الالفي

    1994-01-01

    The ultrastructure of the egg-shell of the fly Synthesiomyia nudiseta has been studied by scanning electron microscopy. The surface of the outer chorion is highly ridged, grooved and has a reticulate appearance except at the collar surrounding the micropyle. There are few aeropyles at the antimicropylar pole. The structure of the egg-shell outside the hatching lines is composed of three layers. The outer layer consists of vertical columns that arise from the middle layer, these columns bra...

  5. Scanning electron microscopy of the teguments of males from five populations of Schistosoma mattheei.

    Science.gov (United States)

    Kruger, F J; Hamilton-Attwell, V L; Schutte, C H

    1986-06-01

    The teguments of males from 5 populations of S. mattheei, of which 3 were sympatric and 2 allopatric with S. haematobium, were studied by means of scanning electron microscopy (SEM). A certain percentage of the males of each sympatric population bore tubercle spines while the allopatric populations were spineless. It is postulated that the presence of tubercle spines is a characteristic inherited from S. haematobium.

  6. Scanning transmission x-ray microscopy: A new ``looking glass`` into coal chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Botto, R.E.; Cody, G.D.

    1994-02-01

    This paper reports the use of scanning transmission x-ray microscopy to spatially map the chemistry of aromatic and aliphatic carbon functionalities in coal to a resolution of less than 0.1 {mu}m. Localized x-ray absorption spectroscopy recorded at the carbon K absorption edge was also used to facilitate analysis of variations in fundamental chemistry at maceral interfaces and within maceral boundaries.

  7. Scanning Electron Microscopy study of Macbat regeneration effect on lead-acid battery electrodes

    OpenAIRE

    Emanuelsson, Christian

    2013-01-01

    Electrodes from lead-acid batteries were studied using scanning electron microscopy and energy dispersive spectroscopy. This to observe the effects of cycling on the batteries and how a capacity recovery process, known as Macbat regeneration, affected the active material with focus on hard sulphation. First, two new batteries were cycled for two months and electrodes from them were studied when the batteries were new, cycled, fully charged after cycling and regenerated after cycling. Then ele...

  8. 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.

  9. Histology and scanning electron microscopy observations of cryopreserved protocorm-like bodies of Dendrobium sonia-28

    OpenAIRE

    POOBATHY, Ranjetta; Sinniah, Uma Rani; RATHINAM, Xavier; Subramaniam, Sreeramanan

    2013-01-01

    The genus Dendrobium possesses horticultural importance. Dendrobium sonia-28 is an important ornamental orchid in the flower industry. Cryopreservation is a favoured long-term storage method for orchids with propagation problems. Protocorm-like bodies (PLBs) of Dendrobium sonia-28 were cryopreserved using the vitrification technique. Histology and scanning electron microscopy (SEM) observations were conducted on stock, non-cryopreserved (control), and cryopreserved PLBs of Dendrobium sonia-28...

  10. Light Microscopy Module: International Space Station Premier Automated Microscope

    Science.gov (United States)

    Sicker, Ronald J.; Foster, William M.; Motil, Brian J.; Meyer, William V.; Chiaramonte, Francis P.; Abbott-Hearn, Amber; Atherton, Arthur; Beltram, Alexander; Bodzioney, Christopher; Brinkman, John; hide

    2016-01-01

    The Light Microscopy Module (LMM) was launched to the International Space Station (ISS) in 2009 and began hardware operations in 2010. It continues to support Physical and Biological scientific research on ISS. During 2016, if all goes as planned, three experiments will be completed: [1] Advanced Colloids Experiments with Heated base-2 (ACE-H2) and [2] Advanced Colloids Experiments with Temperature control (ACE-T1). Preliminary results, along with an overview of present and future LMM capabilities will be presented; this includes details on the planned data imaging processing and storage system, along with the confocal upgrade to the core microscope. [1] a consortium of universities from the State of Kentucky working through the Experimental Program to Stimulate Competitive Research (EPSCoR): Stuart Williams, Gerold Willing, Hemali Rathnayake, et al. and [2] from Chungnam National University, Daejeon, S. Korea: Chang-Soo Lee, et al.

  11. Deconvolved spatial light interference microscopy for live cell imaging.

    Science.gov (United States)

    Haldar, Justin P; Wang, Zhuo; Popescu, Gabriel; Liang, Zhi-Pei

    2011-09-01

    Spatial light interference microscopy (SLIM) is a recently developed method for the label-free imaging of live cells, using the quantitative optical path length through the sample as an endogenous source of contrast. In conventional SLIM, spatial resolution is limited by diffraction and aberrations. This paper describes a novel constrained deconvolution method for improving resolution in SLIM. Constrained deconvolution is enabled by experimental measurement of the system point-spread function and the modeling of coherent image formation in SLIM. Results using simulated and experimental data demonstrate that the proposed method leads to significant improvements in the resolution and contrast of SLIM images. The proposed method should prove useful for high-resolution label-free studies of biological cells and subcellular processes.

  12. Tuning Localized Surface Plasmon Resonance in Scanning Near-Field Optical Microscopy Probes.

    Science.gov (United States)

    Vasconcelos, Thiago L; Archanjo, Bráulio S; Fragneaud, Benjamin; Oliveira, Bruno S; Riikonen, Juha; Li, Changfeng; Ribeiro, Douglas S; Rabelo, Cassiano; Rodrigues, Wagner N; Jorio, Ado; Achete, Carlos A; Cançado, Luiz Gustavo

    2015-06-23

    A reproducible route for tuning localized surface plasmon resonance in scattering type near-field optical microscopy probes is presented. The method is based on the production of a focused-ion-beam milled single groove near the apex of electrochemically etched gold tips. Electron energy-loss spectroscopy and scanning transmission electron microscopy are employed to obtain highly spatially and spectroscopically resolved maps of the milled probes, revealing localized surface plasmon resonance at visible and near-infrared wavelengths. By changing the distance L between the groove and the probe apex, the localized surface plasmon resonance energy can be fine-tuned at a desired absorption channel. Tip-enhanced Raman spectroscopy is applied as a test platform, and the results prove the reliability of the method to produce efficient scattering type near-field optical microscopy probes.

  13. The detection and influence of food soils on microorganisms on stainless steel using scanning electron microscopy and epifluorescence microscopy.

    Science.gov (United States)

    Whitehead, Kathryn A; Smith, Lindsay A; Verran, Joanna

    2010-07-31

    A range of food soils and components (complex [meat extract, fish extract, and cottage cheese extract]; oils [cholesterol, fish oil, and mixed fatty acids]; proteins [bovine serum albumin (BSA), fish peptones, and casein]; and carbohydrates [glycogen, starch, and lactose]) were deposited onto 304 2B finish stainless steel surfaces at different concentrations (10-0.001%). Scanning electron microscopy (SEM) and epifluorescence microscopy were used to visualise the cell and food soil distribution across the surface. Epifluorescence microscopy was also used to quantify the percentage of a field covered by cells or soil. At 10% concentration, most soils, with the exception of BSA and fish peptone were easily visualised using SEM, presenting differences in gross soil morphology and distribution. When soil was stained with acridine orange and visualised by epifluorescence microscopy, the limit of detection of the method varied between soils, but some (meat, cottage cheese and glycogen) were detected at the lowest concentrations used (0.001%). The decrease in soil concentration did not always relate to the surface coverage measurement. When 10% food soil was applied to a surface with Escherichia coli and compared, cell attachment differed depending on the nature of the soil. The highest percentage coverage of cells was observed on surfaces with fish extract and related products (fish peptone and fish oil), followed by carbohydrates, meat extract/meat protein, cottage cheese/casein and the least to the oils (cholesterol and mixed fatty acids). Cells could not be clearly observed in the presence of some food soils using SEM. Findings demonstrate that food soils heterogeneously covered stainless steel surfaces in differing patterns. The pattern and amount of cell attachment was related to food soil type rather than to the amount of food soil detected. This work demonstrates that in the study of conditioning film and cell retention on the hygienic properties of surfaces, SEM

  14. Quantitative assessment of neural outgrowth using spatial light interference microscopy

    Science.gov (United States)

    Lee, Young Jae; Cintora, Pati; Arikkath, Jyothi; Akinsola, Olaoluwa; Kandel, Mikhail; Popescu, Gabriel; Best-Popescu, Catherine

    2017-06-01

    Optimal growth as well as branching of axons and dendrites is critical for the nervous system function. Neuritic length, arborization, and growth rate determine the innervation properties of neurons and define each cell's computational capability. Thus, to investigate the nervous system function, we need to develop methods and instrumentation techniques capable of quantifying various aspects of neural network formation: neuron process extension, retraction, stability, and branching. During the last three decades, fluorescence microscopy has yielded enormous advances in our understanding of neurobiology. While fluorescent markers provide valuable specificity to imaging, photobleaching, and photoxicity often limit the duration of the investigation. Here, we used spatial light interference microscopy (SLIM) to measure quantitatively neurite outgrowth as a function of cell confluence. Because it is label-free and nondestructive, SLIM allows for long-term investigation over many hours. We found that neurons exhibit a higher growth rate of neurite length in low-confluence versus medium- and high-confluence conditions. We believe this methodology will aid investigators in performing unbiased, nondestructive analysis of morphometric neuronal parameters.

  15. Adaptive and robust statistical methods for processing near-field scanning microwave microscopy images.

    Science.gov (United States)

    Coakley, K J; Imtiaz, A; Wallis, T M; Weber, J C; Berweger, S; Kabos, P

    2015-03-01

    Near-field scanning microwave microscopy offers great potential to facilitate characterization, development and modeling of materials. By acquiring microwave images at multiple frequencies and amplitudes (along with the other modalities) one can study material and device physics at different lateral and depth scales. Images are typically noisy and contaminated by artifacts that can vary from scan line to scan line and planar-like trends due to sample tilt errors. Here, we level images based on an estimate of a smooth 2-d trend determined with a robust implementation of a local regression method. In this robust approach, features and outliers which are not due to the trend are automatically downweighted. We denoise images with the Adaptive Weights Smoothing method. This method smooths out additive noise while preserving edge-like features in images. We demonstrate the feasibility of our methods on topography images and microwave |S11| images. For one challenging test case, we demonstrate that our method outperforms alternative methods from the scanning probe microscopy data analysis software package Gwyddion. Our methods should be useful for massive image data sets where manual selection of landmarks or image subsets by a user is impractical. Published by Elsevier B.V.

  16. X-ray diffraction and scanning electron microscopy of galvannealed coatings on steel.

    Science.gov (United States)

    Schmid, P; Uran, K; Macherey, F; Ebert, M; Ullrich, H-J; Sommer, D; Friedel, F

    2009-04-01

    The formation of Fe-Zn intermetallic compounds, as relevant in the commercial product galvannealed steel sheet, was investigated by scanning electron microscopy and different methods of X-ray diffraction. A scanning electron microscope with high resolution was applied to investigate the layers of the galvannealed coating and its topography. Grazing incidence X-ray diffraction (GID) was preferred over conventional Bragg-Brentano geometry for analysing thin crystalline layers because of its lower incidence angle alpha and its lower depth of information. Furthermore, in situ experiments at an environmental scanning electron microscope (ESEM) with an internal heating plate and at an X-ray diffractometer equipped with a high-temperature chamber were carried out. Thus, it was possible to investigate the phase evolution during heat treatment by X-ray diffraction and to display the growth of the zeta crystals in the ESEM.

  17. Identification of a Multicomponent Traditional Herbal Medicine by HPLC-MS and Electron and Light Microscopy.

    Science.gov (United States)

    Liu, Ju-Han; Cheng, Yung-Yi; Hsieh, Chen-Hsi; Tsai, Tung-Hu

    2017-12-15

    Commercial pharmaceutical herbal products have enabled people to take traditional Chinese medicine (TCM) in a convenient and accessible form. However, the quantity and quality should be additionally inspected. To address the issue, a combination of chemical and physical inspection methods were developed to evaluate the amount of an herbal formula, Xiang-Sha-Liu-Jun-Zi-Tang (XSLJZT), in clinical TCM practice. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS) method with electrospray ionization was developed to measure the herbal biomarkers of guanosine, atractylenolide III, glycyrrhizic acid, dehydrocostus lactone, hesperidin, and oleanolic acid from XSLJZT. Scanning electron microscopy (SEM) photographs and light microscopy photographs with Congo red and iodine-KI staining were used to identify the cellulose fibers and starch content. Furthermore, solubility analysis, swelling power test, and crude fiber analysis were contributed to measure the starch additive in pharmaceutical products. The results demonstrated large variations in the chemical components of different pharmaceutical brands. The SEM photographs revealed that the starch was oval, smooth, and granular, and that the raw herbal powder appears stripy, stretched, and filiform. The stained light microscopy photographs of all of the pharmaceutical products showed added starch and raw herbal powder as extenders. The developed chemical and physical methods provide a standard operating procedure for the quantity control of the herbal pharmaceutical products of XSLJZT.

  18. Closed-Loop Feedback Illumination for Optical Inverse Tone-Mapping in Light Microscopy.

    Science.gov (United States)

    Bimber, Oliver; Klöck, Daniel; Amano, Toshiyuki; Grundhöfer, Anselm; Kurz, Daniel

    2011-06-01

    In this paper, we show that optical inverse tone-mapping (OITM) in light microscopy can improve the visibility of specimens, both when observed directly through the oculars and when imaged with a camera. In contrast to previous microscopy techniques, we premodulate the illumination based on the local modulation properties of the specimen itself. We explain how the modulation of uniform white light by a specimen can be estimated in real time, even though the specimen is continuously but not uniformly illuminated. This information is processed and back-projected constantly, allowing the illumination to be adjusted on the fly if the specimen is moved or the focus or magnification of the microscope is changed. The contrast of the specimen's optical image can be enhanced, and high-intensity highlights can be suppressed. A formal pilot study with users indicates that this optimizes the visibility of spatial structures when observed through the oculars. We also demonstrate that the signal-to-noise (S/N) ratio in digital images of the specimen is higher if captured under an optimized rather than a uniform illumination. In contrast to advanced scanning techniques that maximize the S/N ratio using multiple measurements, our approach is fast because it requires only two images. This can improve image analysis in digital microscopy applications with real-time capturing requirements.

  19. Identification of a Multicomponent Traditional Herbal Medicine by HPLC–MS and Electron and Light Microscopy

    Directory of Open Access Journals (Sweden)

    Ju-Han Liu

    2017-12-01

    Full Text Available Background: Commercial pharmaceutical herbal products have enabled people to take traditional Chinese medicine (TCM in a convenient and accessible form. However, the quantity and quality should be additionally inspected. To address the issue, a combination of chemical and physical inspection methods were developed to evaluate the amount of an herbal formula, Xiang-Sha-Liu-Jun-Zi-Tang (XSLJZT, in clinical TCM practice. Methods: A high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS method with electrospray ionization was developed to measure the herbal biomarkers of guanosine, atractylenolide III, glycyrrhizic acid, dehydrocostus lactone, hesperidin, and oleanolic acid from XSLJZT. Scanning electron microscopy (SEM photographs and light microscopy photographs with Congo red and iodine–KI staining were used to identify the cellulose fibers and starch content. Furthermore, solubility analysis, swelling power test, and crude fiber analysis were contributed to measure the starch additive in pharmaceutical products. Results: The results demonstrated large variations in the chemical components of different pharmaceutical brands. The SEM photographs revealed that the starch was oval, smooth, and granular, and that the raw herbal powder appears stripy, stretched, and filiform. The stained light microscopy photographs of all of the pharmaceutical products showed added starch and raw herbal powder as extenders. Conclusion: The developed chemical and physical methods provide a standard operating procedure for the quantity control of the herbal pharmaceutical products of XSLJZT.

  20. Efeitos do processamento químico e da esterilização em Óxido de etileno em osso cortical e esponjoso de ratas: estudo com microscopia de luz e eletrônica de varredura Effects of chemical processing and oxide ethylene sterilization on cortical and cancellous rat bone: a light and electron scanning microscopy study

    Directory of Open Access Journals (Sweden)

    Marcello Teixeira Castiglia

    2009-02-01

    Full Text Available OBJETIVO: Avaliar, sob o ponto de vista microscópico, modificações estruturais do osso esponjoso e cortical, após serem submetidos a processamento químico e esterilização em óxido de etileno. MÉTODOS: Amostras de osso esponjoso e cortical foram obtidas de fêmures de ratas albinas jovens (Wistare separadas em quatro grupos contendo osso cortical e esponjoso: I- Fragmentos secos em estufa; II- Fragmentos secos em estufa e esterilizados em óxido de etileno; III- Fragmentos processados quimicamente; IV- Fragmentos processados quimicamente e esterilizados em óxido de etileno. Metade desse material foi analisada em microscópio eletrônico de varredura e, a outra metade, em microscopia de luz convencional. RESULTADOS: Houve preservação da morfologia geral das amostras em todos os grupos. Nos grupos submetidos ao processamento químico houve melhor preservação do conteúdo celular, enquanto que naqueles submetido ao óxido de etileno houve amalgamação fibrilar. CONCLUSÃO: O tratamento com óxido de etileno causou amalgamação das fibrilas possivelmente em decorrência do efeito do calor e o tratamento químico contribuiu para melhor preservação da estrutura óssea.OBJECTIVE: To evaluate, under microscopic examination, the structural changes displayed by the trabecular and cortical bones after being processed chemically and sterilized by ethylene oxide. METHODS: Samples of cancellous and cortical bones obtained from young female albinus rats (Wistar were assigned to four groups according to the type of treatment: Group I-drying; Group II-drying and ethylene oxide sterilization; III-chemical treatment; IV-chemical treatment and ethylene oxide sterilization. Half of this material was analyzed under ordinary light microscope and the other half using scanning electron microscopy. RESULTS: In all the samples, regardless the group, there was good preservation of the general morphology. For samples submitted to the chemical processing

  1. Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.

    Science.gov (United States)

    Sabel, Nina; Klingberg, Gunilla; Dietz, Wolfram; Nietzsche, Sandor; Norén, Jörgen G

    2010-01-01

    Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia. To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy. Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope. The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous. Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.

  2. 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.

  3. Study of fossil bones by synchrotron radiation micro-spectroscopic techniques and scanning electron microscopy.

    Science.gov (United States)

    Zougrou, I M; Katsikini, M; Pinakidou, F; Paloura, E C; Papadopoulou, L; Tsoukala, E

    2014-01-01

    Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities, e.g. Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the Fe K-edge X-ray absorption fine structure (XAFS) spectra. Finally, Sr K-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1 or Ca2 unit-cell site occupation.

  4. Rapid spontaneous Raman light sheet microscopy using cw-lasers and tunable filters.

    Science.gov (United States)

    Rocha-Mendoza, Israel; Licea-Rodriguez, Jacob; Marro, Mónica; Olarte, Omar E; Plata-Sanchez, Marcos; Loza-Alvarez, Pablo

    2015-09-01

    We perform rapid spontaneous Raman 2D imaging in light-sheet microscopy using continuous wave lasers and interferometric tunable filters. By angularly tuning the filter, the cut-on/off edge transitions are scanned along the excited Stokes wavelengths. This allows obtaining cumulative intensity profiles of the scanned vibrational bands, which are recorded on image stacks; resembling a spectral version of the knife-edge technique to measure intensity profiles. A further differentiation of the stack retrieves the Raman spectra at each pixel of the image which inherits the 3D resolution of the host light sheet system. We demonstrate this technique using solvent solutions and composites of polystyrene beads and lipid droplets immersed in agar and by imaging the C-H (2800-3100cm(-1)) region in a C. elegans worm. The image acquisition time results in 4 orders of magnitude faster than confocal point scanning Raman systems, allowing the possibility of performing fast spontaneous Raman·3D-imaging on biological samples.

  5. Swept source optical coherence microscopy using a 1310 nm VCSEL light source.

    Science.gov (United States)

    Ahsen, Osman O; Tao, Yuankai K; Potsaid, Benjamin M; Sheikine, Yuri; Jiang, James; Grulkowski, Ireneusz; Tsai, Tsung-Han; Jayaraman, Vijaysekhar; Kraus, Martin F; Connolly, James L; Hornegger, Joachim; Cable, Alex; Fujimoto, James G

    2013-07-29

    We demonstrate high speed, swept source optical coherence microscopy (OCM) using a MEMS tunable vertical cavity surface-emitting laser (VCSEL) light source. The light source had a sweep rate of 280 kHz, providing a bidirectional axial scan rate of 560 kHz. The sweep bandwidth was 117 nm centered at 1310 nm, corresponding to an axial resolution of 13.1 µm in air, corresponding to 8.1 µm (9.6 µm spectrally shaped) in tissue. Dispersion mismatch from different objectives was compensated numerically, enabling magnification and field of view to be easily changed. OCM images were acquired with transverse resolutions between 0.86 µm - 3.42 µm using interchangeable 40X, 20X and 10X objectives with ~600 µm x 600 µm, ~1 mm x 1 mm and ~2 mm x 2 mm field-of-view (FOV), respectively. Parasitic variations in path length with beam scanning were corrected numerically. These features enable swept source OCM to be integrated with a wide range of existing scanning microscopes. Large FOV mosaics were generated by serially acquiring adjacent overlapping microscopic fields and combining them in post-processing. Fresh human colon, thyroid and kidney specimens were imaged ex vivo and compared to matching histology sections, demonstrating the ability of OCM to image tissue specimens.

  6. Preservation of protein fluorescence in embedded human dendritic cells for targeted 3D light and electron microscopy.

    Science.gov (United States)

    Höhn, K; Fuchs, J; Fröber, A; Kirmse, R; Glass, B; Anders-Össwein, M; Walther, P; Kräusslich, H-G; Dietrich, C

    2015-08-01

    In this study, we present a correlative microscopy workflow to combine detailed 3D fluorescence light microscopy data with ultrastructural information gained by 3D focused ion beam assisted scanning electron microscopy. The workflow is based on an optimized high pressure freezing/freeze substitution protocol that preserves good ultrastructural detail along with retaining the fluorescence signal in the resin embedded specimens. Consequently, cellular structures of interest can readily be identified and imaged by state of the art 3D confocal fluorescence microscopy and are precisely referenced with respect to an imprinted coordinate system on the surface of the resin block. This allows precise guidance of the focused ion beam assisted scanning electron microscopy and limits the volume to be imaged to the structure of interest. This, in turn, minimizes the total acquisition time necessary to conduct the time consuming ultrastructural scanning electron microscope imaging while eliminating the risk to miss parts of the target structure. We illustrate the value of this workflow for targeting virus compartments, which are formed in HIV-pulsed mature human dendritic cells. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  7. Scanning electron microscopy and synchrotron radiation x-ray tomographic microscopy of 330 million year old charcoalified seed fern fertile organs.

    Science.gov (United States)

    Scott, Andrew C; Galtier, Jean; Gostling, Neil J; Smith, Selena Y; Collinson, Margaret E; Stampanoni, Marco; Marone, Federica; Donoghue, Philip C J; Bengtson, Stefan

    2009-04-01

    Abundant charcoalified seed fern (pteridosperm) pollen organs and ovules have been recovered from Late Viséan (Mississippian 330 Ma) limestones from Kingswood, Fife, Scotland. To overcome limitations of data collection from these tiny, sometimes unique, fossils, we have combined low vacuum scanning electron microscopy on uncoated specimens with backscatter detector and synchrotron radiation X-ray tomographic microscopy utilizing the Materials Science and TOMCAT beamlines at the Swiss Light Source of the Paul Scherrer Institut. In combination these techniques improve upon traditional cellulose acetate peel sectioning because they enable study of external morphology and internal anatomy in multiple planes of section on a single specimen that is retained intact. The pollen organ Melissiotheca shows a basal parenchymatous cushion bearing more than 100 sporangia on the distal face. Digital sections show the occurrence of pollen in some sporangia. The described ovule is new and has eight integumentary lobes that are covered in spirally arranged glandular hairs. Virtual longitudinal sections reveal the lobes are free above the pollen chamber. Results are applied in taxonomy and will subsequently contribute to our understanding of the former diversity and evolution of ovules, seeds, and pollen organs in the seed ferns, the first seed-bearing plants to conquer the land.

  8. Fast axial scanning for 2-photon microscopy using liquid lens technology

    Science.gov (United States)

    Tehrani, Kayvan Forouhesh; Sun, Min Kyoung; Karumbaiah, Lohitash; Mortensen, Luke J.

    2017-02-01

    Scanning microscopy methods require movement of the focus in Z coordinates to produce an image of a 3-dimensional volume. In a typical imaging system, the optical setup is kept fixed and either the sample or the objective is translated with a mechanical stage driven by a stepper motor or a piezoelectric element. Mechanical Z scanning is precise, but its slow response and vulnerability to mechanical vibrations and stress make it disadvantageous to image dynamic, time-varying samples such as live cell structures. An alternative method less susceptible to these problems is to change the focal plane using conjugate optics. Deformable mirrors, acousto-optics, and electrically tunable lenses have been experimented with to achieve this goal and have attained very fast and precise Z-scanning without physically moving the sample. Here, we present the use of a liquid lens for fast axial scanning. Liquid lenses have a long functional life, high degree of phase shift, and low sensitivity to mechanical stress. They work on the principle of refraction at a liquid-liquid interface. At the boundary of a polar and an apolar liquid a spherical surface is formed whose curvature can be controlled by adjusting its relative wettability using electro-wetting. We characterize the effects of the lens on attainable Z displacement, beam spectral characteristics, and pulse duration as compared with mechanical scanning.

  9. Super-resolution for scanning light stimulation systems

    Energy Technology Data Exchange (ETDEWEB)

    Bitzer, L. A.; Neumann, K.; Benson, N., E-mail: niels.benson@uni-due.de; Schmechel, R. [Faculty of Engineering, NST and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, 47057 Duisburg (Germany)

    2016-09-15

    Super-resolution (SR) is a technique used in digital image processing to overcome the resolution limitation of imaging systems. In this process, a single high resolution image is reconstructed from multiple low resolution images. SR is commonly used for CCD and CMOS (Complementary Metal-Oxide-Semiconductor) sensor images, as well as for medical applications, e.g., magnetic resonance imaging. Here, we demonstrate that super-resolution can be applied with scanning light stimulation (LS) systems, which are common to obtain space-resolved electro-optical parameters of a sample. For our purposes, the Projection Onto Convex Sets (POCS) was chosen and modified to suit the needs of LS systems. To demonstrate the SR adaption, an Optical Beam Induced Current (OBIC) LS system was used. The POCS algorithm was optimized by means of OBIC short circuit current measurements on a multicrystalline solar cell, resulting in a mean square error reduction of up to 61% and improved image quality.

  10. Specimen preparation by ion beam slope cutting for characterization of ductile damage by scanning electron microscopy.

    Science.gov (United States)

    Besserer, Hans-Bernward; Gerstein, Gregory; Maier, Hans Jürgen; Nürnberger, Florian

    2016-04-01

    To investigate ductile damage in parts made by cold sheet-bulk metal forming a suited specimen preparation is required to observe the microstructure and defects such as voids by electron microscopy. By means of ion beam slope cutting both a targeted material removal can be applied and mechanical or thermal influences during preparation avoided. In combination with scanning electron microscopy this method allows to examine voids in the submicron range and thus to analyze early stages of ductile damage. In addition, a relief structure is formed by the selectivity of the ion bombardment, which depends on grain orientation and microstructural defects. The formation of these relief structures is studied using scanning electron microscopy and electron backscatter diffraction and the use of this side effect to interpret the microstructural mechanisms of voids formation by plastic deformation is discussed. A comprehensive investigation of the suitability of ion beam milling to analyze ductile damage is given at the examples of a ferritic deep drawing steel and a dual phase steel. © 2016 Wiley Periodicals, Inc.

  11. Three-dimensional imaging of cerebellar mossy fiber rosettes by ion-abrasion scanning electron microscopy.

    Science.gov (United States)

    Kim, Hyun-Wook; Kim, Namkug; Kim, Ki Woo; Rhyu, Im Joo

    2013-08-01

    The detailed knowledge of the three-dimensional (3D) organization of the nervous tissue provides essential information on its functional elucidation. We used serial block-face scanning electron microscopy with focused ion beam (FIB) milling to reveal 3D morphologies of the mossy fiber rosettes in the mice cerebellum. Three-week-old C57 black mice were perfused with a fixative of 1% paraformaldehyde/1% glutaraldehyde in phosphate buffer; the cerebellum was osmicated and embedded in the Araldite. The block containing granule cell layer was sliced with FIB and observed by field-emission scanning electron microscopy. The contrast of backscattered electron image of the block-face was similar to that of transmission electron microscopy and processed using 3D visualization software for further analysis. The mossy fiber rosettes on each image were segmented and rendered to visualize the 3D model. The complete 3D characters of the mossy fiber rosette could be browsed on the A-Works, in-house software, and some preliminary quantitative data on synapse of the rosette could be extracted from these models. Thanks to the development of two-beam imaging and optimized software, we could get 3D information on cerebellar mossy fiber rosettes with ease and speedily, which would be an additive choice to explore 3D structures of the nervous systems and their networks.

  12. Scanning electron microscopy study of adhesion in sea urchin blastulae. M.S. Thesis

    Science.gov (United States)

    Crowther, Susan D.

    1988-01-01

    The dissociation supernatant (DS) isolated by disaggregating Strongylocentrotus purpuratus blastulae in calcium- and magnesium-free seawater specifically promotes reaggregation of S. purpuratus blastula cells. The purpose of this study was to use scanning electron microscopy to examine the gross morphology of aggregates formed in the presence of DS to see if it resembles adhesion in partially dissociated blastulae. A new reaggregation procedure developed here, using large volumes of cell suspension and a large diameter of rotation, was utilized to obtain sufficient quantities of aggregates for scanning electron microscopy. The results indicate that aggregates formed in the presence of DS resemble partially dissociated intact embryos in terms of the direct cell-cell adhesion observed. DS did not cause aggregation to form as a result of the entrapment of cells in masses of extracellular material. These studies provide the groundwork for further studies using transmission electron microscopy to more precisely define the adhesive contacts made by cells in the presence of the putative adhesion molecules present in DS.

  13. Determining the resolution of scanning microwave impedance microscopy using atomic-precision buried donor structures

    Science.gov (United States)

    Scrymgeour, D. A.; Baca, A.; Fishgrab, K.; Simonson, R. J.; Marshall, M.; Bussmann, E.; Nakakura, C. Y.; Anderson, M.; Misra, S.

    2017-11-01

    To quantify the resolution limits of scanning microwave impedance microscopy (sMIM), we created scanning tunneling microscope (STM)-patterned donor nanostructures in silicon composed of 10 nm lines of highly conductive silicon buried under a protective top cap of silicon, and imaged them with sMIM. This dopant pattern is an ideal test of the resolution and sensitivity of the sMIM technique, as it is made with nm-resolution and offers minimal complications from topography convolution. It has been determined that typical sMIM tips can resolve lines down to ∼80 nm spacing, while resolution is independent of tip geometry as extreme tip wear does not change the resolving power, contrary to traditional scanning capacitance microscopy (SCM). Going forward, sMIM is an ideal technique for qualifying buried patterned devices, potentially allowing for quantitative post-fabrication characterization of donor structures, which may be an important tool for the study of atomic-scale transistors and state of the art quantum computation schemes.

  14. Use of polarized light microscopy in porcine reproductive technologies.

    Science.gov (United States)

    Caamaño, J N; Maside, C; Gil, M A; Muñoz, M; Cuello, C; Díez, C; Sánchez-Osorio, J R; Martín, D; Gomis, J; Vazquez, J M; Roca, J; Carrocera, S; Martinez, E A; Gómez, E

    2011-09-01

    The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) could be useful for a non-invasive evaluation of the meiotic spindle and may allow removal of nuclear structures without fluorochrome staining and ultraviolet exposure. In this study, PLM was used to assess its potential application in porcine reproductive technologies. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein in in vitro-matured porcine oocytes; to examine its effects on the oocyte developmental competence; to select oocytes based on the presence of the meiotic spindle detected by PLM; and to assess the efficiency oocyte enucleation assisted with PLM. In the first experiment, the presence of microtubule-polymerized protein was assessed and confirmed in oocytes (n = 117) by immunostaining and chromatin detection. In the second experiment, oocytes (n = 160) were exposed or not (controls) to PLM for 10 minutes, and then parthenogenetically activated and cultured in vitro. In the third experiment, development competence of oocytes with a positive or negative signal to PLM was analyzed after in vitro fertilization. Finally, oocytes (n = 54) were enucleated using PLM as a tool to remove the meiotic spindle. A positive PLM signal was detected in 98.2 % of the oocytes, which strongly correlated (r = 1; p PLM did not differ significantly from controls on cleavage, total blastocyst, expanded blastocyst rates and total cell numbers. The percentage of oocytes at the MII stage and blastocyst formation rate in the negative PLM group significantly differed from control and PLM positive groups. Overall efficiency of spindle removal using the PLM-Oosight system was 92.6%. These results suggest that polarized light microscopy is an efficient system to detect microtubule-polymerized protein in in vitro-matured porcine oocytes and does

  15. Analysis of enamel microbiopsies in shed primary teeth by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM)

    Energy Technology Data Exchange (ETDEWEB)

    Costa de Almeida, Glauce Regina; Molina, Gabriela Ferian; Meschiari, Cesar Arruda [Department of Morphology, Stomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo - FORP/USP, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil); Barbosa de Sousa, Frederico [Department of Morphology, Dental School of Joao Pessoa, Federal University of Paraiba - UFPB, Av Castelo Branco - Campus I, CEP 58.059-900, Joao Pessoa, PB (Brazil); Gerlach, Raquel Fernanda, E-mail: rfgerlach@forp.usp.br [Department of Morphology, Stomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo - FORP/USP, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil)

    2009-09-01

    The aims of this study were 1) to verify how close to the theoretically presumed areas are the areas of enamel microbiopsies carried out in vivo or in exfoliated teeth; 2) to test whether the etching solution penetrates beyond the tape borders; 3) to test whether the etching solution demineralizes the enamel in depth. 24 shed upper primary central incisors were randomly divided into two groups: the Rehydrated Teeth Group and the Dry Teeth Group. An enamel microbiopsy was performed, and the enamel microbiopsies were then analyzed by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM). Quantitative birefringence measurements were performed. The 'true' etched area was determined by measuring the etched enamel using the NIH Image analysis program. Enamel birefringence was compared using the paired t test. There was a statistically significant difference when the etched areas in the Rehydrated teeth were compared with those of the Dry teeth (p = 0.04). The etched areas varied from - 11.6% to 73.5% of the presumed area in the Rehydrated teeth, and from 6.6% to 61.3% in the Dry teeth. The mean percentage of variation in each group could be used as a correction factor for the etched area. Analysis of PM pictures shows no evidence of in-depth enamel demineralization by the etching solution. No statistically significant differences in enamel birefringence were observed between values underneath and outside the microbiopsy area in the same tooth, showing that no mineral loss occurred below the enamel superficial layer. Our data showed no evidence of in-depth enamel demineralization by the etching solution used in the enamel microbiopsy proposed for primary enamel. This study also showed a variation in the measured diameter of the enamel microbiopsy in nineteen teeth out of twenty four, indicating that in most cases the etching solution penetrated beyond the tape borders.

  16. Histology and scanning electron microscopy of the tubal tonsil of goats

    Science.gov (United States)

    Indu, V. R.; Lucy, K. M.; Chungath, J. J.; Ashok, N.; Maya, S.

    2015-01-01

    Aim: To observe the light and scanning electron microscopy (SEM) of the caprine tubal tonsil. Materials and Methods: The study was conducted on six crossbred male goats of 6 months of age. From the median sections of the head, tissue pieces from the nasopharynx around the auditory tube were collected and fixed for histology and SEM. Results: Tonsillar lymphoid tissue was located in the nasopharynx ventral to the auditory tube opening in the lateral wall of the pharynx. The height of the surface epithelium of the tubal tonsil measured 80.17±1.08 µm and was a pseudostratified ciliated columnar type with basal, supporting, and goblet cells. Above the dome of lymphoid nodules, the epithelium was modified into a follicle associated epithelium (FAE), also called lympho-epithelium or reticular epithelium and was characterized by the absence of goblet cells and cilia, reduced number of cell layers, and a large number of lymphoid cells due to interrupted basement membrane. The height of FAE was smaller than that of the surface epithelium and measured 34.33±0.92 µm. The surface of tubal tonsil showed folds and invaginations, which formed crypts. The lamina propria-submucosa underneath the epithelium was formed by the meshwork of reticular and, thin and loose collagen fibers with dome-like accumulation of lymphoid nodules. In the secondary lymphoid nodules, a corona, parafollicular area, and interfnodular area were observed. The average number of lymphoid nodules counted per field under low power magnification of microscope was 1.17±0.17, and the internodular distance was 34.00±4.37 µm. The mean diameter of lymphoid nodules was 566.67±11.45 µm and the lymphocyte count per nodule was 14741.67±174.36. The number of plasma cells counted per field under low power was 44.38±2.90 below the surface epithelium. The tubal tonsil was not encapsulated. In SEM, the surface epithelium of the tubal tonsils presented ciliated cells, microvillus (MV) cells, and goblet cells. The

  17. Histology and scanning electron microscopy of the tubal tonsil of goats

    Directory of Open Access Journals (Sweden)

    V. R. Indu

    2015-08-01

    Full Text Available Aim: To observe the light and scanning electron microscopy (SEM of the caprine tubal tonsil. Materials and Methods: The study was conducted on six crossbred male goats of 6 months of age. From the median sections of the head, tissue pieces from the nasopharynx around the auditory tube were collected and fixed for histology and SEM. Results: Tonsillar lymphoid tissue was located in the nasopharynx ventral to the auditory tube opening in the lateral wall of the pharynx. The height of the surface epithelium of the tubal tonsil measured 80.17±1.08 μm and was a pseudostratified ciliated columnar type with basal, supporting, and goblet cells. Above the dome of lymphoid nodules, the epithelium was modified into a follicle associated epithelium (FAE, also called lympho-epithelium or reticular epithelium and was characterized by the absence of goblet cells and cilia, reduced number of cell layers, and a large number of lymphoid cells due to interrupted basement membrane. The height of FAE was smaller than that of the surface epithelium and measured 34.33±0.92 μm. The surface of tubal tonsil showed folds and invaginations, which formed crypts. The lamina propria-submucosa underneath the epithelium was formed by the meshwork of reticular and, thin and loose collagen fibers with dome-like accumulation of lymphoid nodules. In the secondary lymphoid nodules, a corona, parafollicular area, and interfnodular area were observed. The average number of lymphoid nodules counted per field under low power magnification of microscope was 1.17±0.17, and the internodular distance was 34.00±4.37 μm. The mean diameter of lymphoid nodules was 566.67±11.45 μm and the lymphocyte count per nodule was 14741.67±174.36. The number of plasma cells counted per field under low power was 44.38±2.90 below the surface epithelium. The tubal tonsil was not encapsulated. In SEM, the surface epithelium of the tubal tonsils presented ciliated cells, microvillus (MV cells, and

  18. Investigating Atomic Scale Disordered Stripes in the Cuprate Superconductors with Scanning Tunneling Microscopy

    Science.gov (United States)

    Main, Elizabeth

    The high-Tc cuprate superconductors have been studied for 25 years in the search for the mechanism underlying their superconductivity. In the process, experiments learned that the correlated electrons in these materials organize themselves in a variety of patterns. One such pattern is a type of short-range charge modulations that exist both in and outside of the superconducting phase, which has been linked to the cuprate pseudogap phase. In optimal and slightly underdoped Bi2Sr 2CuO6+delta this charge order (labeled Q*) has wavelength ˜ 5a0. A second and, I argue, related order (Q**) has wavelength of ˜1.25a0. These modulations are highly disordered and for this reason their nature is not fully understood. In this thesis I use scanning tunneling microscopy (STM) to study the disorder of these charge modulations, as an avenue to understanding the nature of the charge order itself. Locally, the charge modulations have a preferred orientation, with a wavevector pointing along one crystal axis or the other. But globally, there is no preferred direction. Our most striking finding is that the local orientation is the same for the Q* and Q** orders, strong new evidence that these two types of charge modulations have the same physical cause. Next, we find that Q* and Q** are subject to two kinds of disorder. Disorder in the optimal local wavelength competes with defect pinning of crests and troughs to produce the disordered modulations that we see. To get our final result, I view the local orientation of the charge modulations as an Ising spin, and compare the resulting Ising maps to theoretical predictions for different classes of disorder. I find the disorder to be consistent with 3D Random Field disorder. New analytical tools were necessary to carry out these measurements. I describe a new algorithm to map the local wavevector of a modulation. Then I present a second new algorithm to correct an STM image for the effects of a slightly anisotropic tip, This thesis also

  19. Histology and scanning electron microscopy of the tubal tonsil of goats.

    Science.gov (United States)

    Indu, V R; Lucy, K M; Chungath, J J; Ashok, N; Maya, S

    2015-08-01

    To observe the light and scanning electron microscopy (SEM) of the caprine tubal tonsil. The study was conducted on six crossbred male goats of 6 months of age. From the median sections of the head, tissue pieces from the nasopharynx around the auditory tube were collected and fixed for histology and SEM. Tonsillar lymphoid tissue was located in the nasopharynx ventral to the auditory tube opening in the lateral wall of the pharynx. The height of the surface epithelium of the tubal tonsil measured 80.17±1.08 µm and was a pseudostratified ciliated columnar type with basal, supporting, and goblet cells. Above the dome of lymphoid nodules, the epithelium was modified into a follicle associated epithelium (FAE), also called lympho-epithelium or reticular epithelium and was characterized by the absence of goblet cells and cilia, reduced number of cell layers, and a large number of lymphoid cells due to interrupted basement membrane. The height of FAE was smaller than that of the surface epithelium and measured 34.33±0.92 µm. The surface of tubal tonsil showed folds and invaginations, which formed crypts. The lamina propria-submucosa underneath the epithelium was formed by the meshwork of reticular and, thin and loose collagen fibers with dome-like accumulation of lymphoid nodules. In the secondary lymphoid nodules, a corona, parafollicular area, and interfnodular area were observed. The average number of lymphoid nodules counted per field under low power magnification of microscope was 1.17±0.17, and the internodular distance was 34.00±4.37 µm. The mean diameter of lymphoid nodules was 566.67±11.45 µm and the lymphocyte count per nodule was 14741.67±174.36. The number of plasma cells counted per field under low power was 44.38±2.90 below the surface epithelium. The tubal tonsil was not encapsulated. In SEM, the surface epithelium of the tubal tonsils presented ciliated cells, microvillus (MV) cells, and goblet cells. The region of FAE possessed Type-I and

  20. The Role of Gas in Determining Image Quality and Resolution During In Situ Scanning Transmission Electron Microscopy Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuanyuan [Physical & Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Browning, Nigel D. [Physical & Computational Science Directorate, Pacific Northwest National Laboratory, Richland WA 99352 USA; Department of Materials Science and Engineering, University of Washington, Seattle WA 98195 USA

    2017-08-02

    As gas-solid heterogeneous catalytic reactions are molecular in nature, a full mechanistic understanding of the process requires atomic scale characterization under realistic operating conditions. While atomic resolution imaging has become a routine in modern high-vacuum (scanning) transmission electron microscopy ((S)TEM), both image quality and resolution nominally degrade when reaction gases are introduced. In this work, we systematically assess the effects of different gases at various pressures on the quality and resolution of images obtained at room temperature in the annular dark field STEM imaging mode using a differentially pumped (DP) gas cell. This imaging mode is largely free from inelastic scattering effects induced by the presence of gases and retains good imaging properties over a wide range of gas mass/pressures. We demonstrate the application of the ESTEM with atomic resolution images of a complex oxide alkane oxidation catalyst MoVNbTeOx (M1) immersed in light and heavy gas environments.

  1. An easy-to-implement filter for separating photo-excited signals from topography in scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang Kangkang; Rosenmann, Daniel; Holt, Martin; Winarski, Robert; Hla, Saw-Wai [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Rose, Volker [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

    2013-06-15

    In order to achieve elemental and chemical sensitivity in scanning tunneling microscopy (STM), synchrotron x-rays have been applied to excite core-level electrons during tunneling. The x-ray photo-excitations result in tip currents that are superimposed onto conventional tunneling currents. While carrying important physical information, the varying x-ray induced currents can destabilize the feedback loop causing it to be unable to maintain a constant tunneling current, sometimes even causing the tip to retract fully or crash. In this paper, we report on an easy-to-implement filter circuit that can separate the x-ray induced currents from conventional tunneling currents, thereby allowing simultaneous measurements of topography and chemical contrasts. The filter and the schematic presented here can also be applied to other variants of light-assisted STM such as laser STM.

  2. Imaging and quantitative data acquisition of biological cell walls with Atomic Force Microscopy and Scanning Acoustic Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tittmann, B. R. [Penn State; Xi, X. [Penn State

    2014-09-01

    This chapter demonstrates the feasibility of Atomic Force Microscopy (AFM) and High Frequency Scanning Acoustic Microscopy (HF-SAM) as tools to characterize biological tissues. Both the AFM and the SAM have shown to provide imaging (with different resolution) and quantitative elasticity measuring abilities. Plant cell walls with minimal disturbance and under conditions of their native state have been examined with these two kinds of microscopy. After descriptions of both the SAM and AFM, their special features and the typical sample preparation is discussed. The sample preparation is focused here on epidermal peels of onion scales and celery epidermis cells which were sectioned for the AFM to visualize the inner surface (closest to the plasma membrane) of the outer epidermal wall. The nm-wide cellulose microfibrils orientation and multilayer structure were clearly observed. The microfibril orientation and alignment tend to be more organized in older scales compared with younger scales. The onion epidermis cell wall was also used as a test analog to study cell wall elasticity by the AFM nanoindentation and the SAM V(z) feature. The novelty in this work was to demonstrate the capability of these two techniques to analyze isolated, single layered plant cell walls in their natural state. AFM nanoindentation was also used to probe the effects of Ethylenediaminetetraacetic acid (EDTA), and calcium ion treatment to modify pectin networks in cell walls. The results suggest a significant modulus increase in the calcium ion treatment and a slight decrease in EDTA treatment. To complement the AFM measurements, the HF-SAM was used to obtain the V(z) signatures of the onion epidermis. These measurements were focused on documenting the effect of pectinase enzyme treatment. The results indicate a significant change in the V(z) signature curves with time into the enzyme treatment. Thus AFM and HF-SAM open the door to a systematic nondestructive structure and mechanical property

  3. Annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography of polymer systems.

    Science.gov (United States)

    Lu, Kangbo; Sourty, Erwan; Loos, Joachim

    2010-08-01

    We have utilized bright-field conventional transmission electron microscopy tomography and annular dark-field scanning transmission electron microscopy (ADF-STEM) tomography to characterize a well-defined carbon black (CB)-filled polymer nanocomposite with known CB volume concentration. For both imaging methods, contrast can be generated between the CB and the surrounding polymer matrix. The involved contrast mechanisms, in particular for ADF-STEM, will be discussed in detail. The obtained volume reconstructions were analysed and the CB volume concentrations were carefully determined from the reconstructed data. For both imaging modes, the measured CB volume concentrations are substantially different and only quantification based on the ADF-STEM data revealed about the same value as the known CB loading. Moreover, when applying low-convergence angles for imaging ADF-STEM tomography, data can be obtained of micrometre-thick samples.

  4. Scanning Transmission X-ray Microscopy: Applications in Atmospheric Aerosol Research

    Energy Technology Data Exchange (ETDEWEB)

    Moffet, Ryan C.; Tivanski, Alexei V.; Gilles, Mary K.

    2011-01-20

    Scanning transmission x-ray microscopy (STXM) combines x-ray microscopy and near edge x-ray absorption fine structure spectroscopy (NEXAFS). This combination provides spatially resolved bonding and oxidation state information. While there are reviews relevant to STXM/NEXAFS applications in other environmental fields (and magnetic materials) this chapter focuses on atmospheric aerosols. It provides an introduction to this technique in a manner approachable to non-experts. It begins with relevant background information on synchrotron radiation sources and a description of NEXAFS spectroscopy. The bulk of the chapter provides a survey of STXM/NEXAFS aerosol studies and is organized according to the type of aerosol investigated. The purpose is to illustrate the current range and recent growth of scientific investigations employing STXM-NEXAFS to probe atmospheric aerosol morphology, surface coatings, mixing states, and atmospheric processing.

  5. Carbon contamination in scanning transmission electron microscopy and its impact on phase-plate applications.

    Science.gov (United States)

    Hettler, Simon; Dries, Manuel; Hermann, Peter; Obermair, Martin; Gerthsen, Dagmar; Malac, Marek

    2017-05-01

    We analyze electron-beam induced carbon contamination in a transmission electron microscope. The study is performed on thin films potentially suitable as phase plates for phase-contrast transmission electron microscopy. Electron energy-loss spectroscopy and phase-plate imaging is utilized to analyze the contamination. The deposited contamination layer is identified as a graphitic carbon layer which is not prone to electrostatic charging whereas a non-conductive underlying substrate charges. Several methods that inhibit contamination are evaluated and the impact of carbon contamination on phase-plate imaging is discussed. The findings are in general interesting for scanning transmission electron microscopy applications. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  6. Atomic species identification at the (101) anatase surface by simultaneous scanning tunnelling and atomic force microscopy

    Science.gov (United States)

    Stetsovych, Oleksandr; Todorović, Milica; Shimizu, Tomoko K.; Moreno, César; Ryan, James William; León, Carmen Pérez; Sagisaka, Keisuke; Palomares, Emilio; Matolín, Vladimír; Fujita, Daisuke; Perez, Ruben; Custance, Oscar

    2015-01-01

    Anatase is a pivotal material in devices for energy-harvesting applications and catalysis. Methods for the accurate characterization of this reducible oxide at the atomic scale are critical in the exploration of outstanding properties for technological developments. Here we combine atomic force microscopy (AFM) and scanning tunnelling microscopy (STM), supported by first-principles calculations, for the simultaneous imaging and unambiguous identification of atomic species at the (101) anatase surface. We demonstrate that dynamic AFM-STM operation allows atomic resolution imaging within the material's band gap. Based on key distinguishing features extracted from calculations and experiments, we identify candidates for the most common surface defects. Our results pave the way for the understanding of surface processes, like adsorption of metal dopants and photoactive molecules, that are fundamental for the catalytic and photovoltaic applications of anatase, and demonstrate the potential of dynamic AFM-STM for the characterization of wide band gap materials. PMID:26118408

  7. Two-dimensional dopant profiling of gallium nitride p–n junctions by scanning capacitance microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lamhamdi, M. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Ecole national des sciences appliquées khouribga, Université Hassan 1er, 26000 Settat (Morocco); Cayrel, F. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France); Frayssinet, E. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Bazin, A.E.; Yvon, A.; Collard, E. [STMicroelectronics, 16 Rue Pierre et Marie Curie, BP 7155, 37071 Tours (France); Cordier, Y. [CRHEA-CNRS, Rue Bernard Grégory, Sophia Antipolis, 06560 Valbonne (France); Alquier, D. [GREMAN UMR 7347-Université de Tours, 10 Rue Thales de Milet, BP 7155, 37071 Tours (France)

    2016-04-01

    Two-dimensional imaging of dopant profiles for n and p-type regions are relevant for the development of new power semiconductors, especially for gallium nitride (GaN) for which classical profiling techniques are not adapted. This is a challenging task since it needs a technique with simultaneously good sensitivity, high spatial resolution and high dopant gradient resolution. To face these challenges, scanning capacitance microscopy combined with Atomic Force Microscopy is a good candidate, presenting reproducible results, as demonstrated in literature. In this work, we attempt to distinguish reliably and qualitatively the various doping concentrations and type at p–n and unipolar junctions. For both p–n and unipolar junctions three kinds of samples were prepared and measured separately. The space-charge region of the p–n metallurgical junction, giving rise to different contrasts under SCM imaging, is clearly observed, enlightening the interest of the SCM technique.

  8. Light sheet microscopy reveals more gradual light attenuation in light green versus dark green soybean leaves

    Science.gov (United States)

    Light wavelengths preferentially absorbed by chlorophyll (chl) often display steep absorption gradients. This oversaturates photosynthesis in upper chloroplasts and deprives lower chloroplasts of blue and red light, causing a steep gradient in carbon fixation. Reducing chl content could create a mor...

  9. Quantitative polarized light microscopy of unstained mammalian cochlear sections

    Science.gov (United States)

    Kalwani, Neil M.; Ong, Cheng Ai; Lysaght, Andrew C.; Haward, Simon J.; McKinley, Gareth H.; Stankovic, Konstantina M.

    2013-02-01

    Hearing loss is the most common sensory deficit in the world, and most frequently it originates in the inner ear. Yet, the inner ear has been difficult to access for diagnosis because of its small size, delicate nature, complex three-dimensional anatomy, and encasement in the densest bone in the body. Evolving optical methods are promising to afford cellular diagnosis of pathologic changes in the inner ear. To appropriately interpret results from these emerging technologies, it is important to characterize optical properties of cochlear tissues. Here, we focus on that characterization using quantitative polarized light microscopy (qPLM) applied to unstained cochlear sections of the mouse, a common animal model of human hearing loss. We find that the most birefringent cochlear materials are collagen fibrils and myelin. Retardance of the otic capsule, the spiral ligament, and the basilar membrane are substantially higher than that of other cochlear structures. Retardance of the spiral ligament and the basilar membrane decrease from the cochlear base to the apex, compared with the more uniform retardance of other structures. The intricate structural details revealed by qPLM of unstained cochlear sections ex vivo strongly motivate future application of polarization-sensitive optical coherence tomography to human cochlea in vivo.

  10. Submonolayer growth of Pd on Cu(111) studied by scanning tunneling microscopy

    DEFF Research Database (Denmark)

    Lægsgaard, E.; Ruban, Andrei; Stensgaard, I.

    1998-01-01

    The growth mode of sub-monolayer amounts of Pd on Cu(111) in the temperature range - 80-300 degrees C has been investigated by scanning tunneling microscopy (STM), Rutherford backscattering spectroscopy (RBS) and Auger electron spectroscopy (AES). Below approximate to 100 degrees C, the Pd induced...... is dug out from the surface in extended, monolayer deep pits, and concurrently, the brims and islands increase in height by one layer. High-resolution STM images of brims and islands in this phase are interpreted as evidence for Cu capping. For Pd evaporation at temperatures of 220-300 degrees C...

  11. 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.

  12. Atomic bonding effects in annular dark field scanning transmission electron microscopy. II. Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Odlyzko, Michael L.; Held, Jacob T.; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu [Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2016-07-15

    Quantitatively calibrated annular dark field scanning transmission electron microscopy (ADF-STEM) imaging experiments were compared to frozen phonon multislice simulations adapted to include chemical bonding effects. Having carefully matched simulation parameters to experimental conditions, a depth-dependent bonding effect was observed for high-angle ADF-STEM imaging of aluminum nitride. This result is explained by computational predictions, systematically examined in the preceding portion of this study, showing the propagation of the converged STEM beam to be highly sensitive to net interatomic charge transfer. Thus, although uncertainties in experimental conditions and simulation accuracy remain, the computationally predicted experimental bonding effect withstands the experimental testing reported here.

  13. Vortex imaging and local magnetization studies in HTS by scanning Hall probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A.; Pross, A.; Cole, D.; Bending, S

    2004-08-01

    We have used scanning Hall probe microscopy to correlate vortex images and local magnetisation measurements in two different high temperature superconducting samples. Near the edge of a continuous YBCO thin film we have observed local hysteresis inversion and negative remanent fields, which can be semi-quantitatively explained in terms of a theoretical model of flux penetration in an infinitely long superconducting strip. In a YBCO film containing a regular square array of antidots we have further find that vortices trapped at antidots exhibit an unusual behaviour upon field sweep reversal.

  14. Low-Level Detection of Poly(amidoamine PAMAM Dendrimers Using Immunoimaging Scanning Probe Microscopy

    Directory of Open Access Journals (Sweden)

    Chevelle A. Cason

    2012-01-01

    Full Text Available Immunoimaging scanning probe microscopy was utilized for the low-level detection and quantification of biotinylated G4 poly(amidoamine PAMAM dendrimers. Results were compared to those of high-performance liquid chromatography (HPLC and found to provide a vastly improved analytical method for the low-level detection of dendrimers, improving the limit of detection by a factor of 1000 (LOD=2.5×10−13 moles. The biorecognition method is reproducible and shows high specificity and good accuracy. In addition, the capture assay platform shows a promising approach to patterning dendrimers for nanotechnology applications.

  15. In vivo measurements of skin barrier: comparison of different methods and advantages of laser scanning microscopy

    Science.gov (United States)

    Patzelt, A.; Sterry, W.; Lademann, J.

    2010-12-01

    A major function of the skin is to provide a protective barrier at the interface between external environment and the organism. For skin barrier measurement, a multiplicity of methods is available. As standard methods, the determination of the transepidermal water loss (TEWL) as well as the measurement of the stratum corneum hydration, are widely accepted, although they offer some obvious disadvantages such as increased interference liability. Recently, new optical and spectroscopic methods have been introduced to investigate skin barrier properties in vivo. Especially, laser scanning microscopy has been shown to represent an excellent tool to study skin barrier integrity in many areas of relevance such as cosmetology, occupation, diseased skin, and wound healing.

  16. Scanning probe microscopy estimation of the wear resistance of the surface of a modified PVC film

    Science.gov (United States)

    Kochetkova, A. S.; Gorbushin, P. N.; Sosnov, E. A.; Kolert, K.; Malygin, A. A.

    2017-04-01

    An atomic force microscopy technique is proposed to determine the wear resistance of a protective coating deposited by the sol-gel method on the surface of a polyvinylchloride film. The force of action of a probe on a sample is estimated under various scanning conditions. It is shown that the obtained data on the resistance of a coating to the action of a probe in the contact mode can be used to qualitatively estimate the adhesion of the coating to the surface of a polymer matrix.

  17. Structure and Reactions of Carbon and Hydrogen on Ru(0001): A Scanning Tunneling Microscopy Study

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Tomoko K.; Mugarza, Aitor; Cerda, Jorge; Salmeron, Miquel

    2008-09-09

    The interaction between carbon and hydrogen atoms on a Ru(0001) surface was studied using scanning tunneling microscopy (STM), Density Functional Theory (DFT) and STM image calculations. Formation of CH species by reaction between adsorbed H and C was observed to occur readily at 100 K. When the coverage of H increased new complexes of the form CH+nH (n = 1, 2 and 3) were observed. These complexes, never observed before, might be precursors for further hydrogenation reactions. DFT analysis reveals that a considerable energy barrier exists for the CH+H {yields} CH{sub 2} reaction.

  18. Compositional analysis of GaAs/AlGaAs heterostructures using quantitative scanning transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kauko, H.; Helvoort, A. T. J. van [Department of Physics, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Zheng, C. L.; Glanvill, S. [Monash Centre for Electron Microscopy, Monash University, VIC 3800 (Australia); Zhu, Y.; Etheridge, J., E-mail: joanne.etheridge@monash.edu [Monash Centre for Electron Microscopy, Monash University, VIC 3800 (Australia); Department of Materials Engineering, Monash University, VIC 3800 (Australia); Dwyer, C. [Monash Centre for Electron Microscopy, Monash University, VIC 3800 (Australia); Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Munshi, A. M.; Fimland, B. O. [Department of Electronics and Telecommunications, Norwegian University of Science and Technology (NTNU), Trondheim (Norway)

    2013-12-02

    We demonstrate a method for compositional mapping of Al{sub x}Ga{sub 1–x}As heterostructures with high accuracy and unit cell spatial resolution using quantitative high angle annular dark field scanning transmission electron microscopy. The method is low dose relative to spectroscopic methods and insensitive to the effective source size and higher order lens aberrations. We apply the method to study the spatial variation in Al concentration in cross-sectioned GaAs/AlGaAs core-shell nanowires and quantify the concentration in the Al-rich radial band and the AlGaAs shell segments.

  19. Metadislocations in complex metallic alloys: A high-resolution scanning transmission electron microscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Heggen, Marc; Houben, Lothar; Feuerbacher, Michael [Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)

    2011-07-01

    Metadislocations are highly complex defects which involve several hundreds of atoms in their core. We present a microstructural investigation on Metadislocations using aberration-corrected high-resolution scanning transmission electron microscopy. A novel and highly complex deformation mechanism is found which is based on the movement of a metadislocation core mediating strain and separate escort defects. Upon deformation, the escort defects move along with the metadislocation core and locally transform the material structure. This mechanism implies the coordinated movement of hundreds of atoms per elementary step. Although the mechanism is very complex, it can be described by a simple jigsaw-puzzle-like rearrangement of basic structural subunits.

  20. Cytochrome C Dynamics at Gold and Glassy Carbon Surfaces Monitored by in Situ Scanning Tunnel Microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Møller, Per; Pedersen, Marianne Vind

    1995-01-01

    We have investigated the absorption of cytochrome c on gold and glassy carbon substrates by in situ scanning tunnel microscopy under potentiostatic control of both substrate and tip. Low ionic strength and potential ranges where no Faradaic current flows were used. Cyt c aggregates into flat...... composite structures of about 50 nm lateral extension at gold surfaces. The aggregates evolve in time, and structures resembling individual cyt c molecules can be distinguished in the space between the 50 nm structures. Cyt c aggregates also form at glassy carbon but have a different, unbroken character...

  1. Monolithically Integrated, Mechanically Resilient Carbon-Based Probes for Scanning Probe Microscopy

    Science.gov (United States)

    Kaul, Anupama B.; Megerian, Krikor G.; Jennings, Andrew T.; Greer, Julia R.

    2010-01-01

    Scanning probe microscopy (SPM) is an important tool for performing measurements at the nanoscale in imaging bacteria or proteins in biology, as well as in the electronics industry. An essential element of SPM is a sharp, stable tip that possesses a small radius of curvature to enhance spatial resolution. Existing techniques for forming such tips are not ideal. High-aspect-ratio, monolithically integrated, as-grown carbon nanofibers (CNFs) have been formed that show promise for SPM applications by overcoming the limitations present in wet chemical and separate substrate etching processes.

  2. Calibration of Electrochemical Capacitance-voltage Method on Pyramid Texture Surface Using Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Y.; Cesar, I. [ECN Solar Energy, P.O.Box 1, 1755ZG Petten (Netherlands); Harata, D. [Department of Electronic Science and Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8530 (Japan); Schuring, E.W. [ECN Environment and Energy Engineering, P.O.Box 1, 1755ZG Petten (Netherlands); Vlooswijk, A.H.G.; Venema, P.R. [Tempress Systems BV, Radeweg 31, 8171MD Vaassen (Netherlands); Katori, S.; Fujita, S. [Photonics and Electronics Science and Engineering Center, Kyoto University, Nishikyo-ku, Kyoto 615-8530 (Japan)

    2013-07-01

    The electrochemical capacitance-voltage (ECV) technique can practically profile carrier concentrations on textured surfaces, but reliable calibration of the surface area is strongly demanded since it plays a decisive role in calculating both the carrier concentration and the profiling depth. In this work, we calibrate the area factor of pyramidally textured surfaces by comparing ECV profiles with cross-sectional scanning electron microscopy image, and found out it is 1.66, and not 1.73 which was formerly assumed. Furthermore, the calibrated area factor was applied to POCl3 and BBr3 diffusions which resulted in comparable diffusion profiles for both textured and polished surfaces.

  3. Observations on mouthparts of Dermatobia hominis (Linneaus Jr., 1781) (Diptera: Cuterebridae) by scanning electron microscopy.

    Science.gov (United States)

    Fernandes, Fernando de Freitas; Linardi, Pedro Marcos

    2002-02-01

    The ultrastructure of the mouthparts of Dermatobia hominis was studied using scanning electron microscopy. The morphological characteristics of the segments, articulations, sensory organs, and pilose covering are described. Mechanoreceptors of the long trichoid sensillum and smaller trichoid sensillum types were observed, as well as labellar gustatory receptors of the basiconic sensillum type, which differed between the sexes. These observations are discussed with reference to the current literature on the morphology and sense organs of dipteran mouthparts, and the prevailing view that the adult mouthparts of this species are non-functional is challenged.

  4. Atomic-scale structure of dislocations revealed by scanning tunneling microscopy and molecular dynamics

    DEFF Research Database (Denmark)

    Christiansen, Jesper; Morgenstern, K.; Schiøtz, Jakob

    2002-01-01

    The intersection between dislocations and a Ag(111) surface has been studied using an interplay of scanning tunneling microscopy (STM) and molecular dynamics. Whereas the STM provides atomically resolved information about the surface structure and Burgers vectors of the dislocations......, the simulations can be used to determine dislocation structure and orientation in the near-surface region. In a similar way, the subsurface structure of other extended defects can be studied. The simulations show dislocations to reorient the partials in the surface region leading to an increased splitting width...

  5. Low-Level Detection of Poly(amidoamine) PAMAM Dendrimers Using Immunoimaging Scanning Probe Microscopy.

    Science.gov (United States)

    Cason, Chevelle A; Fabré, Thomas A; Buhrlage, Andrew; Haik, Kristi L; Bullen, Heather A

    2012-01-01

    Immunoimaging scanning probe microscopy was utilized for the low-level detection and quantification of biotinylated G4 poly(amidoamine) PAMAM dendrimers. Results were compared to those of high-performance liquid chromatography (HPLC) and found to provide a vastly improved analytical method for the low-level detection of dendrimers, improving the limit of detection by a factor of 1000 (LOD = 2.5 × 10(-13) moles). The biorecognition method is reproducible and shows high specificity and good accuracy. In addition, the capture assay platform shows a promising approach to patterning dendrimers for nanotechnology applications.

  6. Teaching Plasmonics, Scanning Probe Microscopy and Other Useful Experiments at the Upper Level

    Science.gov (United States)

    Sanchez, Erik

    2012-10-01

    It is important to teach students concepts and experimental skills relating to modern research being performed today. Experiments that help educate students about the latest research helps them get jobs and into the doors at many great academic institutions. PSU's Advanced Experimental Class for physics undergraduates offers many novel experiments to help the students accomplish this task. Labs involving Plasmonics, thin film deposition, scanning probe microscopy (SPM) and more will be discussed. In addition, a new NSF funded project involving the building of a Do-It-Yourself (DIY) SPM will be discussed.

  7. Creating Nanoscale Pits on Solid Surfaces in Aqueous Environment with Scanning Tunnelling Microscopy

    DEFF Research Database (Denmark)

    Chi, Qijin; Zhang, Jingdong; Friis, Esben P.

    2000-01-01

    A novel method has been developed to fabricate nanoscale pits on Au(111) in aqueous environments by in situ scanning tunnelling microscopy (STM), based on critical interactions between tip and substrate. The most striking advantages of the present method are that the dimension and position...... of the pits can be controlled well in aqueous environments, and the operations are simple. Parameters affecting the pit formation and size have been systematically characterized to show that pit formation is dominated by bias voltage. A mechanism is proposed based on local surface reconstruction induced...

  8. Scanning electron microscopy of the collodion membrane from a self-healing collodion baby*

    Science.gov (United States)

    de Almeida Jr., Hiram Larangeira; Isaacsson, Henrique; Guarenti, Isabelle Maffei; Silva, Ricardo Marques e; de Castro, Luis Antônio Suita

    2015-01-01

    Abstract Self-healing collodion baby is a well-established subtype of this condition. We examined a male newborn, who was covered by a collodion membrane. The shed membrane was examined with scanning electron microscopy. The outer surface showed a very compact keratin without the normal elimination of corneocytes. The lateral view of the specimen revealed a very thick, horny layer. The inner surface showed the structure of lower corneocytes with polygonal contour. With higher magnifications villous projections were seen in the cell membrane. PMID:26375232

  9. Reliable strain measurement in transistor arrays by robust scanning transmission electron microscopy

    Directory of Open Access Journals (Sweden)

    Suhyun Kim

    2013-09-01

    Full Text Available Accurate measurement of the strain field in the channels of transistor arrays is critical for strain engineering in modern electronic devices. We applied atomic-resolution high-angle annular dark-field scanning transmission electron microscopy to quantitative measurement of the strain field in transistor arrays. The quantitative strain profile over 20 transistors was obtained with high reliability and a precision of 0.1%. The strain field was found to form homogeneously in the channels of the transistor arrays. Furthermore, strain relaxation due to the thin foil effect was quantitatively investigated for thicknesses of 35 to 275 nm.

  10. Identification of nitrogen dopants in single-walled carbon nanotubes by scanning tunneling microscopy.

    Science.gov (United States)

    Tison, Yann; Lin, Hong; Lagoute, Jérôme; Repain, Vincent; Chacon, Cyril; Girard, Yann; Rousset, Sylvie; Henrard, Luc; Zheng, Bing; Susi, Toma; Kauppinen, Esko I; Ducastelle, François; Loiseau, Annick

    2013-08-27

    Using scanning tunnelling microscopy and spectroscopy, we investigated the atomic and electronic structure of nitrogen-doped single walled carbon nanotubes synthesized by chemical vapor deposition. The insertion of nitrogen in the carbon lattice induces several types of point defects involving different atomic configurations. Spectroscopic measurements on semiconducting nanotubes reveal that these local structures can induce either extended shallow levels or more localized deep levels. In a metallic tube, a single doping site associated with a donor state was observed in the gap at an energy close to that of the first van Hove singularity. Density functional theory calculations reveal that this feature corresponds to a substitutional nitrogen atom in the carbon network.

  11. Dopant migration in silicon during implantation/annealing measured by scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hessel, H.E.; Memmert, U.; Behm, R.J. (Univ. Muenchen (West Germany)); Cerva, H. (Siemens Research Lab., Muenchen (West Germany))

    In this paper spatial correlation between the lateral distribution of the doping type and the former implantation mask edge was investigated by scanning tunneling microscopy (STM) measurements. The position of the former mask edge was determined from surface steps resolved by STM topography measurements. Current imaging tunneling spectroscopy (CITS) data recorded simultaneously allowed to detect the transition from a high doping level with an ohmic I-V curve to a lower doping level displaying a Schottky barrier behavior. The influence of different annealing treatments on the position of this transition was investigated.

  12. Direct Measurement of Built-in Electrical Potential in Photovoltaic Devices by Scanning Kelvin Probe Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, C. S.; Mutinho, H. R.; Hasoon, F. S.; Al-Thani, H. A.; Friedman, D. J.; Geisz, J. F.; Wang, Q.; Romero, M. J.; Al-Jassim, M. M.

    2003-05-01

    We report on direct measurements of the built-in electrical potential in Cu(In,Ga)Se2, GaInP2 single-junction, and GaInP2/GaAs tandem-junction solar cells, by using scanning Kelvin probe microscopy. Potential profiles on cross sections of the devices were measured quantitatively and spatially resolved in open and short circuit, under and without illuminations, with selective photon energies matching the band gaps of the junctions. The measurements provide valuable information about the electrical properties of the devices and are useful for understanding the performance and improving the design of solar cells.

  13. Calibration and examination of piezoresistive Wheatstone bridge cantilevers for scanning probe microscopy.

    Science.gov (United States)

    Gotszalk, Teodor; Grabiec, Piotr; Rangelow, Ivo W

    2003-01-01

    This paper describes the method of determining the force constant and displacement sensitivity of piezoresistive Wheatstone bridge cantilevers applied in scanning probe microscopy (SPM). In the procedure presented here, the force constant for beams with various geometry is determined based on resonance frequency measurement. The displacement sensitivity is measured by the deflection of the cantilever with the calibrated piezoactuator stage. Preliminary results show that our method is capable of measuring the force constant of Wheatstone bridge cantilevers with an accuracy of better than 5% and this is used as feedback for improvement of sensor micromachining process.

  14. Quantitative study of mammalian cells by scanning transmission soft X-ray microscopy

    Science.gov (United States)

    Shinohara, K.; Ohigashi, T.; Toné, S.; Kado, M.; Ito, A.

    2017-06-01

    Molecular distribution in mammalian cells was studied by soft X-ray scanning transmission microscopy with respect to the quantitative aspect of analysis. NEXAFS profiles at the C, N and O K-absorption edges were combined and used for the analysis. For the estimation of quantity for nucleic acids and proteins, NEXAFS profiles of DNA and bovine serum albumin (BSA) at the N K-absorption edge were applied assuming that those were their representatives. The method has a potential to explore the other molecular components than nucleic acids and proteins.

  15. Circular photocurrent response of a topological insulator thin film probed by scanning photocurrent microscopy

    Science.gov (United States)

    Qu, Dong-Xia; Kou, Xufeng; Lang, Murong; Crowhurst, Jonathan; Armstrong, Michael; Zaug, Joseph; Wang, Kang L.; Chapline, George

    2015-03-01

    The remarkable nature of surface states in topological insulators is expected to have a unique photocurrent response to electromagnetic radiation. However, the surface and bulk photo-excited charge transport mechanisms, in relation to the band bending at the electrode-topological insulator interface, have not been well understood. Here, we present scanning photocurrent microscopy measurements on a gated topological insulator microdevice and show that the spin-polarized photocurrent displays direction reversal near the electrical contact interfaces. We discuss two possible mechanisms, which alternatively play dominant roles in the helicity-dependent photocurrent map. Our analysis determines the magnitude of each contribution, and reveals the governing process under different gate conditions.

  16. Fatal poisoning by Rumex crispus (curled dock): pathological findings and application of scanning electron microscopy.

    Science.gov (United States)

    Reig, R; Sanz, P; Blanche, C; Fontarnau, R; Dominguez, A; Corbella, J

    1990-10-01

    A case of fatal poisoning due to ingestion of the plant Rumex crispus (curled dock) is described. The patient, a 53-year-old male, presented with gastrointestinal symptoms, severe hypocalcemia, metabolic acidosis and acute hepatic insufficiency. Despite therapeutic measures, the patient died 72 h after ingestion of the plant material. Noteworthy among the pathological findings were centrolobular hepatic necrosis and birefringent crystals in the liver and kidneys that were identified by histochemical techniques and scanning electron microscopy. These observations are compared with other reports in the medical literature, with an emphasis on the risk involved in the use of these plants for culinary or medicinal purposes.

  17. First-principles modelling of scanning tunneling microscopy using non-equilibrium Green's functions

    DEFF Research Database (Denmark)

    Lin, H.P.; Rauba, J.M.C.; Thygesen, Kristian Sommer

    2010-01-01

    The investigation of electron transport processes in nano-scale architectures plays a crucial role in the development of surface chemistry and nano-technology. Experimentally, an important driving force within this research area has been the concurrent refinements of scanning tunneling microscopy...... into account. As an illustrating example we apply the NEGF-STM method to the Si(001)(2x1):H surface with sub-surface P doping and discuss the results in comparison to the Bardeen and Tersoff-Hamann methods....

  18. Doppler-scanning tunneling microscopy current imaging in superconductor-ferromagnet hybrids

    Energy Technology Data Exchange (ETDEWEB)

    Moore, S. A.; Plummer, G.; Fedor, J.; Pearson, J. E.; Novosad, V.; Karapetrov, G.; Iavarone, M.

    2016-01-25

    Mapping the distribution of currents inside a superconductor is usually performed indirectly through imaging of the stray magnetic fields above the surface. Here, we show that by direct imaging of the Doppler shift contribution to the quasiparticle excitation spectrum in the superconductor using low temperature scanning tunneling microscopy, we obtain directly the distribution of supercurrents inside the superconductor. We demonstrate the technique at the example of superconductor/ferromagnet hybrid structure that produces intricate current pattern consisting of combination Meissner shielding currents and Abrikosov vortex currents.

  19. Imaging plant nuclei and membrane-associated cytoskeleton by field emission scanning electron microscopy.

    Science.gov (United States)

    Fišerová, Jindřiška; Goldberg, Martin W

    2014-01-01

    Scanning electron microscopy (SEM) is a powerful technique that can image exposed surfaces in 3D. Modern scanning electron microscopes, with field emission electron sources and in-lens specimen chambers, achieve resolutions of better than 0.5 nm and thus offer views of ultrastructural details of subcellular structures or even macromolecular complexes. Obtaining a reliable image is, however, dependent on sample preparation methods that robustly but accurately preserve biological structures. In plants, exposing the object of interest may be difficult due to the existence of a cell wall. This protocol shows how to isolate plant nuclei for SEM imaging of the nuclear envelope and associated structures from both sides of the nuclear envelope in cultured cells as well as in leaf or root cells. Further, it provides a method for uncovering membrane-associated cytoskeletal structures.

  20. High resolution characterizations of fine structure of semiconductor device and material using scanning nonlinear dielectric microscopy

    Science.gov (United States)

    Cho, Yasuo

    2017-10-01

    Scanning nonlinear dielectric microscopy (SNDM) can easily distinguish the dopant type (PN) and has a wide dynamic range of sensitivity from low to high concentrations of dopants, because it has a high sensitivity to capacitance variation on the order of 10-22 F/\\sqrt{\\text{Hz}} . It is also applicable to the analysis of compound semiconductors with much lower signal levels than Si. We can avoid misjudgments from the two-valued function (contrast reversal) problem of dC/dV signals. Under an ultrahigh-vacuum condition, SNDM has atomic resolution. As the extended versions of SNDM, super-higher-order SNDM, local-deep-level transient spectroscopy, noncontact SNDM, and scanning nonlinear dielectric potentiometory have been developed and introduced. The favorable features of SNDM originate from its significantly high sensitivity.

  1. Revisit laser scanning fluorescence microscopy performance under fluorescence-lifetime-limited regime

    Science.gov (United States)

    Chan, Antony C.; Wong, Terence T. W.; Wong, Kenneth K. Y.; Lam, Edmund Y.; Tsia, Kevin K.

    2014-03-01

    Continuing desire for higher-speed laser scanning fluorescence microscopy (LSFM) and progressive advancement in ultrafast and sensitive photodetectors might imply that our conventional understanding of LSFM is not adequate when approaching to the intrinsic speed limit — fluorescence lifetime. In this regard, we here revisit the theoretical framework of LSFM and evaluate its general performance in lifetime-limited and noise-limited regimes. Our model suggests that there still exists an order-of-magnitude gap between the current LSFM speed and the intrinsic limit. An imaging frame rate of > 100 kHz could be viable with the emerging laser-scanning techniques using ultrafast wavelength-swept sources, or optical time-stretch.

  2. High Speed Scanning Ion Conductance Microscopy for Quantitative Analysis of Nanoscale Dynamics of Microvilli.

    Science.gov (United States)

    Ida, Hiroki; Takahashi, Yasufumi; Kumatani, Akichika; Shiku, Hitoshi; Matsue, Tomokazu

    2017-06-06

    Observation of nanoscale structure dynamics on cell surfaces is essential to understanding cell functions. Hopping-mode scanning ion conductance microscopy (SICM) was used to visualize the topography of fragile convoluted nanoscale structures on cell surfaces under noninvasive conditions. However, conventional hopping mode SICM does not have sufficient temporal resolution to observe cell-surface dynamics in situ because of the additional time required for performing vertical probe movements of the nanopipette. Here, we introduce a new scanning algorithm for high speed SICM measurements using low capacitance and high-resonance-frequency piezo stages. As a result, a topographic image is taken within 18 s with a 64 × 64 pixel resolution at 10 × 10 μm. The high speed SICM is applied to the characterization of microvilli dynamics on surfaces, which shows clear structural changes after the epidermal growth factor stimulation.

  3. Destructive effects induced by the electron beam in scanning electron microscopy

    Science.gov (United States)

    Popescu, M. C.; Bita, B. I.; Banu, M. A.; Tomescu, R. M.

    2016-12-01

    The Scanning Electron Microscopy has been validated by its impressive imaging and reliable measuring as an essential characterization tool for a variety of applications and research fields. This paper is a comprehensive study dedicated to the undesirable influence of the accelerated electron beam associated with the dielectric materials, sensitive structures or inappropriate sample manipulation. Depending on the scanning conditions, the electron beam may deteriorate the investigated sample due to the extended focusing or excessive high voltage and probe current applied on vulnerable configurations. Our aim is to elaborate an instructive material for improved SEM visualization capabilities by overcoming the specific limitations of the technique. Particular examination and measuring methods are depicted along with essential preparation and manipulation procedures in order to protect the integrity of the sample. Various examples are mentioned and practical solutions are described in respect to the general use of the electron microscope.

  4. MRT letter: An extended scanning probe microscopy system for macroscopic topography imaging.

    Science.gov (United States)

    Fu, Ji; Li, Faxin

    2014-10-01

    Enlightened by the principle of scanning probe microscopy or atomic force microscope (AFM), we proposed a novel surface topography imaging system based on the scanning of a piezoelectric unimorph cantilever. The height of sample surface can be obtained by recording the cantilever's strain using an ultra-sensitive strain gauge and the Z-axis movement is realized by electric bending of the cantilever. This system can be operated in the way similar to the contact mode in AFM, with the practical height detection resolution better than 100 nm. Imaging of the inner surface of a steel tube and on a transparent wing of a honey bee were conducted and the obtained results showed that this proposed system is a very promising solution for in situ topography mapping. © 2014 Wiley Periodicals, Inc.

  5. Scanning tunneling microscopy investigation of different porphynoids on a Ni-prestructured Cu(111) surface

    Energy Technology Data Exchange (ETDEWEB)

    Roeckert, Michael; Buchner, Florian; Zillner, Elisabeth; Glaessel, Stefanie; Steinrueck, Hans-Peter; Marbach, Hubertus [Lehrstuhl fuer Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Universitaet Erlangen-Nuernberg, Egerlandstrasse 3, D-91058 Erlangen (Germany)

    2010-07-01

    The assembly of organic molecules on single-crystal surfaces is an approach towards the creation of novel materials with outstanding properties. Porphyrins appear to be ideal candidates to generate functional molecular devices, due to their self-assembly properties and their versatile functionality. In the present work we study the possibility to locally anchor or functionalize porphyrins on a prestructured surface, namely a composite Ni/Cu(111) surface, by scanning tunneling microscopy (STM) in ultra-high vacuum at room temperature. Based on scanning tunneling micrographs and movies the dynamics, assembly and intramolecular conformation of the corresponding porphyrins (2HTPP,CoTPP,OEP) as well as the role of molecule-molecule and molecule-substrate interactions are discussed. The obtained findings indeed indicate the possibility to locally anchor and/or functionalize (e.g. metalate) the porphyrins on a Cu(111) surface prestructured either with atomically flat Ni- or oxygen-islands.

  6. Seeing the forest tree by tree: super-resolution light microscopy meets the neurosciences.

    Science.gov (United States)

    Maglione, Marta; Sigrist, Stephan J

    2013-07-01

    Light microscopy can be applied in vivo and can sample large tissue volumes, features crucial for the study of single neurons and neural circuits. However, light microscopy per se is diffraction-limited in resolution, and the substructure of core signaling compartments of neuronal circuits--axons, presynaptic active zones, postsynaptic densities and dendritic spines-can be only insufficiently characterized by standard light microscopy. Recently, several forms of super-resolution light microscopy breaking the diffraction-imposed resolution limit have started to allow highly resolved, dynamic imaging in the cell-biologically highly relevant 10-100 nanometer range ('mesoscale'). New, sometimes surprising answers concerning how protein mobility and protein architectures shape neuronal communication have already emerged. Here we start by briefly introducing super-resolution microscopy techniques, before we describe their use in the analysis of neuronal compartments. We conclude with long-term prospects for super-resolution light microscopy in the molecular and cellular neurosciences.

  7. Comparative analysis of Trichuris muris surface using conventional, low vacuum, environmental and field emission scanning electron microscopy

    National Research Council Canada - National Science Library

    Lopes Torres, Eduardo José; de Souza, Wanderley; Miranda, Kildare

    2013-01-01

    .... The morphology of Trichuris spp. and other helminths has been mostly studied using conventional scanning electron microscopy of chemically fixed, dried and metal-coated specimens, although this kind of preparation has been shown...

  8. THE INTEGRATED USE OF COMPUTATIONAL CHEMISTRY, SCANNING PROBE MICROSCOPY, AND VIRTUAL REALITY TO PREDICT THE CHEMICAL REACTIVITY OF ENVIRONMENTAL SURFACES

    Science.gov (United States)

    In the last decade three new techniques scanning probe microscopy (SPM), virtual reality (YR) and computational chemistry ave emerged with the combined capability of a priori predicting the chemically reactivity of environmental surfaces. Computational chemistry provides the cap...

  9. Atomic force microscopy of red-light photoreceptors using peakforce quantitative nanomechanical property mapping.

    Science.gov (United States)

    Kroeger, Marie E; Sorenson, Blaire A; Thomas, J Santoro; Stojković, Emina A; Tsonchev, Stefan; Nicholson, Kenneth T

    2014-10-24

    Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be measured to ~10 pN by a laser and sectored detector, which can be converted to image topography. Amplitude modulation or "tapping mode" AFM involves the probe making intermittent contact with the surface while oscillating at its resonant frequency to produce an image. Used in conjunction with a fluid cell, tapping-mode AFM enables the imaging of biological macromolecules such as proteins in physiologically relevant conditions. Tapping-mode AFM requires manual tuning of the probe and frequent adjustments of a multitude of scanning parameters which can be challenging for inexperienced users. To obtain high-quality images, these adjustments are the most time consuming. PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) produces an image by measuring a force response curve for every point of contact with the sample. With ScanAsyst software, PF-QNM can be automated. This software adjusts the set-point, drive frequency, scan rate, gains, and other important scanning parameters automatically for a given sample. Not only does this process protect both fragile probes and samples, it significantly reduces the time required to obtain high resolution images. PF-QNM is compatible for AFM imaging in fluid; therefore, it has extensive application for imaging biologically relevant materials. The method presented in this paper describes the application of PF-QNM to obtain images of a bacterial red-light photoreceptor, RpBphP3 (P3), from photosynthetic R. palustris in its light-adapted state. Using this method, individual protein dimers of P3 and aggregates of dimers have been observed on a mica surface in the presence of an imaging buffer. With appropriate adjustments to surface and/or solution concentration, this method may be generally applied to other biologically relevant macromolecules and soft materials.

  10. Critical-point drying and gold sputtering as applied to scanning electron microscopy of human reproductive tissues.

    Science.gov (United States)

    Ludwig, H; Metzger, H; Hafez, E S

    1976-01-01

    Improved techniques have been developed for washing, pinning, fixation, dehydration and critical-point drying of tissues of female and male reproductive tracts, gametes, for viewing by scanning electron microscopy. The sputtering method, performed by an ion gun, is applied to shadow and produce a thin film of gold. Technical details and metal coating are noted which are suitable to improve images of surface ultrastructure of cilia and microvilli. Studies using scanning electron microscopy, histological and histochemical techniques, and cinematography are described.

  11. Simultaneous X-ray fluorescence and scanning X-ray diffraction microscopy at the Australian Synchrotron XFM beamline

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Michael W. M.; Phillips, Nicholas W.; van Riessen, Grant A.; Abbey, Brian; Vine, David J.; Nashed, Youssef S. G.; Mudie, Stephen T.; Afshar, Nader; Kirkham, Robin; Chen, Bo; Balaur, Eugeniu; de Jonge, Martin D.

    2016-08-11

    Owing to its extreme sensitivity, quantitative mapping of elemental distributionsviaX-ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X-ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super-resolved ultra-structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step- and fly-scanning modes, robust, simultaneous XFM-SXDM is demonstrated.

  12. Scanning tunneling microscopy I general principles and applications to clean and absorbate-covered surfaces

    CERN Document Server

    Wiesendanger, Roland

    1994-01-01

    Since the first edition of "Scanning 'funneling Microscopy I" has been pub­ lished, considerable progress has been made in the application of STM to the various classes of materials treated in this volume, most notably in the field of adsorbates and molecular systems. An update of the most recent develop­ ments will be given in an additional Chapter 9. The editors would like to thank all the contributors who have supplied up­ dating material, and those who have provided us with suggestions for further improvements. We also thank Springer-Verlag for the decision to publish this second edition in paperback, thereby making this book affordable for an even wider circle of readers. Hamburg, July 1994 R. Wiesendanger Preface to the First Edition Since its invention in 1981 by G. Binnig, H. Rohrer and coworkers at the IBM Zurich Research Laboratory, scanning tunneling microscopy (STM) has devel­ oped into an invaluable surface analytical technique allowing the investigation of real-space surface structures at th...

  13. Thirty per cent contrast in secondary-electron imaging by scanning field-emission microscopy.

    Science.gov (United States)

    Zanin, D A; De Pietro, L G; Peter, Q; Kostanyan, A; Cabrera, H; Vindigni, A; Bähler, Th; Pescia, D; Ramsperger, U

    2016-11-01

    We perform scanning tunnelling microscopy (STM) in a regime where primary electrons are field-emitted from the tip and excite secondary electrons out of the target-the scanning field-emission microscopy regime (SFM). In the SFM mode, a secondary-electron contrast as high as 30% is observed when imaging a monoatomic step between a clean W(110)- and an Fe-covered W(110)-terrace. This is a figure of contrast comparable to STM. The apparent width of the monoatomic step attains the 1 nm mark, i.e. it is only marginally worse than the corresponding width observed in STM. The origin of the unexpected strong contrast in SFM is the material dependence of the secondary-electron yield and not the dependence of the transported current on the tip-target distance, typical of STM: accordingly, we expect that a technology combining STM and SFM will highlight complementary aspects of a surface while simultaneously making electrons, selected with nanometre spatial precision, available to a macroscopic environment for further processing.

  14. Scanning two-photon microscopy with upconverting lanthanide nanoparticles via Richardson-Lucy deconvolution

    Science.gov (United States)

    Gainer, Christian F.; Utzinger, Urs

    2012-01-01

    Abstract. The use of upconverting lanthanide nanoparticles in fast-scanning microscopy is hindered by a long luminescence decay time, which greatly blurs images acquired in a nondescanned mode. We demonstrate herein an image processing method based on Richardson-Lucy deconvolution that mitigates the detrimental effects of their luminescence lifetime. This technique generates images with lateral resolution on par with the system’s performance, ∼1.2  μm, while maintaining an axial resolution of 5 μm or better at a scan rate comparable with traditional two-photon microscopy. Remarkably, this can be accomplished with near infrared excitation power densities of 850  W/cm2, several orders of magnitude below those used in two-photon imaging with molecular fluorophores. By way of illustration, we introduce the use of lipids to coat and functionalize these nanoparticles, rendering them water dispersible and readily conjugated to biologically relevant ligands, in this case epidermal growth factor receptor antibody. This deconvolution technique combined with the functionalized nanoparticles will enable three-dimensional functional tissue imaging at exceptionally low excitation power densities. PMID:22894486

  15. Magnetic scanning gate microscopy of CoFeB lateral spin valve

    Science.gov (United States)

    Corte-León, Héctor; Scarioni, Alexander Fernandez; Mansell, Rhodri; Krzysteczko, Patryk; Cox, David; McGrouther, Damien; McVitie, Stephen; Cowburn, Russell; Schumacher, Hans W.; Antonov, Vladimir; Kazakova, Olga

    2017-05-01

    Devices comprised of CoFeB nanostructures with perpendicular magnetic anisotropy and non-magnetic Ta channel were operated in thermal lateral spin valve (LSV) mode and studied by magnetotransport measurements and magnetic scanning gate microscopy (SGM). Due to the short spin diffusion length of Ta, the spin diffusion signal was suppressed, allowing the study of the contribution from the anomalous Nernst (ANE) and anomalous Hall effects (AHE). The magnetotransport measurements identified the switching fields of the CoFeB nanostructures and demonstrated a combination of AHE and ANE when the devices were operated in thermally-driven spin-injection mode. Modified scanning probe microscopy probes were fabricated by placing a NdFeB magnetic bead (MB) on the apex of a commercial Si probe. The dipole magnetic field distribution around the MB was characterized by using differential phase contrast technique and direct measurement of the switching field induced by the bead in the CoFeB nanodevices. Using SGM we demonstrate the influence of localized magnetic field on the CoFeB nanostructures near the non-magnetic channel. This approach provides a promising route towards the study of thermal and spin diffusion effects using local magnetic fields.

  16. Magnetic scanning gate microscopy of CoFeB lateral spin valve

    Directory of Open Access Journals (Sweden)

    Héctor Corte-León

    2017-05-01

    Full Text Available Devices comprised of CoFeB nanostructures with perpendicular magnetic anisotropy and non-magnetic Ta channel were operated in thermal lateral spin valve (LSV mode and studied by magnetotransport measurements and magnetic scanning gate microscopy (SGM. Due to the short spin diffusion length of Ta, the spin diffusion signal was suppressed, allowing the study of the contribution from the anomalous Nernst (ANE and anomalous Hall effects (AHE. The magnetotransport measurements identified the switching fields of the CoFeB nanostructures and demonstrated a combination of AHE and ANE when the devices were operated in thermally-driven spin-injection mode. Modified scanning probe microscopy probes were fabricated by placing a NdFeB magnetic bead (MB on the apex of a commercial Si probe. The dipole magnetic field distribution around the MB was characterized by using differential phase contrast technique and direct measurement of the switching field induced by the bead in the CoFeB nanodevices. Using SGM we demonstrate the influence of localized magnetic field on the CoFeB nanostructures near the non-magnetic channel. This approach provides a promising route towards the study of thermal and spin diffusion effects using local magnetic fields.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Nobuyuki, E-mail: ISHIDA.Nobuyuki@nims.go.jp [Global Research Center for Environment and Energy based on Nanomaterials Science (GREEN), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Fujita, Daisuke [Global Research Center for Environment and Energy based on Nanomaterials Science (GREEN), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Advanced Nanocharacterization Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2013-02-15

    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. A streaming multi-GPU implementation of image simulation algorithms for scanning transmission electron microscopy.

    Science.gov (United States)

    Pryor, Alan; Ophus, Colin; Miao, Jianwei

    2017-01-01

    Simulation of atomic-resolution image formation in scanning transmission electron microscopy can require significant computation times using traditional methods. A recently developed method, termed plane-wave reciprocal-space interpolated scattering matrix (PRISM), demonstrates potential for significant acceleration of such simulations with negligible loss of accuracy. Here, we present a software package called Prismatic for parallelized simulation of image formation in scanning transmission electron microscopy (STEM) using both the PRISM and multislice methods. By distributing the workload between multiple CUDA-enabled GPUs and multicore processors, accelerations as high as 1000 × for PRISM and 15 × for multislice are achieved relative to traditional multislice implementations using a single 4-GPU machine. We demonstrate a potentially important application of Prismatic, using it to compute images for atomic electron tomography at sufficient speeds to include in the reconstruction pipeline. Prismatic is freely available both as an open-source CUDA/C++ package with a graphical user interface and as a Python package, PyPrismatic.

  19. Bulk crystalline copper electrodeposition on polycrystalline gold surfaces observed by in-situ scanning tunneling microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Møller, Per

    1994-01-01

    Bulk copper electrodeposition onto technical gold surfaces in electrolytes of 0.05 M H2SO4 and 1 mM CuSO4 was investigated by in-situ scanning tunnelling microscopy at fixed overpotentials. At potentials between -60 and -30 mV the growth of bulk copper proceeds in cycles of nucleation, agglomerat......Bulk copper electrodeposition onto technical gold surfaces in electrolytes of 0.05 M H2SO4 and 1 mM CuSO4 was investigated by in-situ scanning tunnelling microscopy at fixed overpotentials. At potentials between -60 and -30 mV the growth of bulk copper proceeds in cycles of nucleation......, agglomeration and crystallization. Crystalline copper is seen as involving an intermediate stage in the progress of growth. The final stage in the growth involves an equilibrium of copper electrochemically dissolving and precipitating. The drift velocity was measured for a gold surface subjected to flame...... annealing and subsequently installed in the cell compartment. It was found that the drift velocity decays with time in an exponential-like manner, and a 70 min waiting time before experiments with atomic resolution is recommended. Atomic resolution on Au(111) has been obtained, and an apparent surface...

  20. Visible light spectral domain optical coherence microscopy system for ex vivo imaging

    Science.gov (United States)

    Lichtenegger, Antonia; Harper, Danielle J.; Augustin, Marco; Eugui, Pablo; Fialová, Stanislava; Woehrer, Adelheid; Hitzenberger, Christoph K.; Baumann, Bernhard

    2017-02-01

    A visible light spectral domain optical coherence microscopy system operating in the wavelength range of 450-680 nm was developed. The resulting large wavelength range of 230 nm enabled an ultrahigh axial resolution of 0.88μm in tissue. The setup consisted of a Michelson interferometer combined with a homemade spectrometer with a spectral resolution of 0.03 nm. Scanning of 1 x 1 mm2 and 0.5 x 0.5 mm2 areas was performed by an integrated microelectromechanical mirror. After scanning the light beam is focused onto the tissue by a commercial objective with a 10 x magnification, resulting in a transverse resolution of 2 μm . Specification measurements showed that a -89 dB sensitivity with a 24 dB/mm roll-off could be achieved with the system. First of all the capabilities of the system were tested by investigating millimeter paper, tape and the USAF (US Air Force) 1951 resolution test target. Finally cerebral tissues from non-pathological and Alzheimer's disease affected brains were investigated. The results showed that structures, such as white and gray matter, could be distinguished. Furthermore a first effort was made to differentiate Alzheimer's disease from healthy brain tissue.