Differences between time domain and Fourier domain optical coherence tomography in imaging tissues
Summary
It has been numerously demonstrated that both time domain and Fourier domain optical coherence tomography (OCT) can generate high‐resolution depth‐resolved images of living tissues and cells. In this work, we compare the common points and differences between two methods when the continuous and random properties of live tissue are taken into account. It is found that when relationships that exist between the scattered light and tissue structures are taken into account, spectral interference measurements in Fourier domain OCT (FDOCT) is more advantageous than interference fringe envelope measurements in time doma...
Source: Journal of Microscopy - June 1, 2017 Category: Laboratory Medicine Authors: W. GAO, X. WU Tags: Original Article Source Type: research
Application of an advanced maximum likelihood estimation restoration method for enhanced ‐resolution and contrast in second‐harmonic generation microscopy
Summary
Second‐harmonic generation (SHG) microscopy has gained popularity because of its ability to perform submicron, label‐free imaging of noncentrosymmetric biological structures, such as fibrillar collagen in the extracellular matrix environment of various organs with high contrast and specificity. Because SHG is a two‐photon coherent scattering process, it is difficult to define a point spread function (PSF) for this modality. Hence, compared to incoherent two‐photon processes like two‐photon fluorescence, it is challenging to apply the various PSF‐engineering methods to improve the spatial resolution to b...
Source: Journal of Microscopy - June 1, 2017 Category: Laboratory Medicine Authors: MAYANDI SIVAGURU, MOHAMMAD M. KABIR, MANAS RANGAN GARTIA, DAVID S.C. BIGGS, BARGHAV S. SIVAGURU, VIGNESH A. SIVAGURU, GLENN A. FRIED, GANG LOGAN LIU, SAKTHIVEL SADAYAPPAN, KIMANI C. TOUSSAINT Tags: Original Article Source Type: research
About the contrast of δ’ precipitates in bulk Al–Cu–Li alloys in reflection mode with a field‐emission scanning electron microscope at low accelerating voltage
Summary
Characterising the impact of lithium additions in the precipitation sequence in Al–Li–Cu alloys is important to control the strengthening of the final material. Since now, transmission electron microscopy (TEM) at high beam voltage has been the technique of choice to monitor the size and spatial distribution of δ’ precipitates (Al3Li). Here we report on the imaging of the δ’ phase in such alloys using backscattered electrons (BSE) and low accelerating voltage in a high‐resolution field‐emission scanning electron microscope. By applying low‐energy Ar+ ion milling to the surface after mechanical polis...
Source: Journal of Microscopy - June 1, 2017 Category: Laboratory Medicine Authors: NICOLAS BRODUSCH, FR ÉDÉRIC VOISARD, RAYNALD GAUVIN Tags: Original Article Source Type: research
The elusive ettringite under the high ‐vacuum SEM – a reflection based on natural samples, the use of Monte Carlo modelling of EDS analyses and an extension to the ettringite group minerals
Summary
Ettringite, Ca6Al2(SO4)3(OH)12.26H2O, or C6A3H32 as it is known in cement chemistry notation, is a major phase of interest in cement science as an hydration product and in polluted soil treatment since its structure can accommodate with many hazardous cations. Beyond those anthropogenic features, ettringite is first of all a naturally occurring mineral (although rare). An example of its behaviour under the scanning electron microscope and during energy dispersive spectroscopy (EDS) qualitative analysis is presented, based on the study of natural ettringite crystals from the N'Chwaning mine in South Africa. Monte Ca...
Source: Journal of Microscopy - May 30, 2017 Category: Laboratory Medicine Authors: VINCENT THI ÉRY, VINCENT TRINCAL, CATHERINE A. DAVY Tags: Original Article Source Type: research
A component ‐by‐component characterisation of high‐risk atherosclerotic plaques by multiphoton microscopic imaging
Conclusions: Recognition of the distinct signatures of various plaque components suggests that MPM has the potential to offer next‐generation characterisation of atherosclerotic plaques. The higher lateral resolution (comparable to histology) images generated by MPM for identifying plaque components might complement larger field of view and greater imaging depth currently available with optical coherence tomography imaging. As the next step MPM would need to be evaluated for intact vessel imaging ex vivo and in vivo.
Lay description
Multiphoton microscopy (MPM), an optical imaging technique that allows visualisation of ...
Source: Journal of Microscopy - May 30, 2017 Category: Laboratory Medicine Authors: M. JAIN, B. WU, D. PISAPIA, S. SALVATORE, S. MUKHERJEE, N. NARULA Tags: Original Article Source Type: research
The biomechanical, chemical and physiological adaptations of the eggs of two Australian megapodes to their nesting strategies and their implications for extinct titanosaur dinosaurs
Summary
Megapodes are galliform birds endemic to Australasia and unusual among modern birds in that they bury their eggs for incubation in diverse substrates and using various strategies. Alectura lathami and Leipoa ocellata are Australian megapodes that build and nest in mounds of soil and organic matter. Such unusual nesting behaviours have resulted in particular evolutionary adaptations of their eggs and eggshells. We used a combination of scanning electron microscopy, including electron backscatter diffraction and energy‐dispersive X‐ray spectroscopy, to determine the fine structure of the eggshells and micro‐CT ...
Source: Journal of Microscopy - May 30, 2017 Category: Laboratory Medicine Authors: G. GRELLET ‐TINNER, S. LINDSAY, M.B. THOMPSON Tags: Hot Topic ‐ fast‐tracked short communication Source Type: research
Perceptually accurate display of two greyscale images as a single colour image
Summary
Life scientists often desire to display the signal from two different molecular probes as a single colour image, so as to convey information about the probes’ relative concentrations as well as their spatial corelationship. Traditionally, such colour images are created through a merge display, where each greyscale signal is assigned to different channels of an RGB colour image. However, human perception of colour and greyscale intensity is not equivalent. Thus, a merged image display conveys to the typical viewer only a subset of the absolute and relative intensity information present in and between two greyscale...
Source: Journal of Microscopy - May 30, 2017 Category: Laboratory Medicine Authors: A.B. TAYLOR, M.S. IOANNOU, T. WATANABE, K. HAHN, T. ‐L. CHEW Tags: Original Article Source Type: research
A novel method to analyse in vivo the physiological state and cell viability of phototrophic microorganisms by confocal laser scanning microscopy using a dual laser
Summary
Phototrophic microorganisms are very abundant in extreme environments, where are subjected to frequent and strong changes in environmental parameters. Nevertheless, little is known about the physiological effects of these changing environmental conditions on viability of these microorganisms, which are difficult to grow in solid media and have the tendency to form aggregates. For that reason, it is essential to develop methodologies that provide data in short time consuming, in vivo and with minimal manipulating the samples, in response to distinct stress conditions.
In this paper, we present a novel method using C...
Source: Journal of Microscopy - May 30, 2017 Category: Laboratory Medicine Authors: LAIA MILLACH, ALEIX OBIOL, ANTONIO SOL É, ISABEL ESTEVE Tags: Original Article Source Type: research
Local photocurrent mapping and cell performance behaviour on a nanometre scale for monolithically interconnected Cu(In,Ga)Se2 solar cells
Summary
The local efficiency of lamellar shaped Cu(In,Ga)Se2 solar cells has been investigated using scanning near‐field optical microscopy (SNOM). Topographic and photocurrent measurements have been performed simultaneously with a 100 nm tip aperture. The lamellar shaped solar cell with monolithic interconnects (P scribe) has been investigated on a nanometre scale for the first time at different regions using SNOM. It was found that, the cell region between P1 and P2 significantly contributes to the solar cells overall photocurrent generation. The photocurrent produced depends locally on the sample topography and it is ...
Source: Journal of Microscopy - May 26, 2017 Category: Laboratory Medicine Authors: M. HAGGUI, B. REINHOLD, P. ANDRAE, D. GREINER, M. SCHMID, P. FUMAGALLI Tags: Original Article Source Type: research
Improved sampling and analysis of images in corneal confocal microscopy
Conclusion: The study demonstrated a significant difference in the CNFL values between the randomized and common sampling method indicating the importance of clear guidelines for the image sampling. The increase in CNFL and CNBD values when using the adjusted cornea area is not surprising. The observed increases in both CNFL and CNBD values when using the manual method of nerve quantification compared to the automatic method are consistent with earlier findings. This study underlines the importance of improving the analysis of the CCM images in order to obtain more objective corneal nerve fibre measurements.
Lay descrip...
Source: Journal of Microscopy - May 26, 2017 Category: Laboratory Medicine Authors: E.L. SCHALDEMOSE, F.I. FONTAIN, P. KARLSSON, J.R. NYENGAARD Tags: Original Article Source Type: research
Chronic sleep restriction disrupts interendothelial junctions in the hippocampus and increases blood –brain barrier permeability
In this study we characterised the ultrastructure of interendothelial junctions in the hippocampus, the expression of tight junction proteins, and quantified blood–brain barrier permeability to fluorescein‐sodium after chronic sleep restriction. Male Wistar rats were sleep restricted using the modified multiple platform method during 10 days, with a daily schedule of 20‐h sleep deprivation plus 4‐h sleep recovery at their home‐cages. At the 10th day hippocampal samples were obtained immediately at the end of the 20‐h sleep deprivation period, and after 40 and 120 min of sleep recovery. Samples were processed fo...
Source: Journal of Microscopy - May 23, 2017 Category: Laboratory Medicine Authors: G. HURTADO ‐ALVARADO, J. VELÁZQUEZ‐MOCTEZUMA, B. GÓMEZ‐GONZÁLEZ Tags: Original Article Source Type: research
Iron oxide nanoparticles decrease nuclear fractal dimension of buccal epithelial cells in a time ‐dependent manner
Summary
In this paper, we present results that iron oxide nanoparticles (IONPs) induce time‐dependent structural changes in nuclei of buccal epithelial cells. The cells were treated with magnetite, Fe3O4 nanoparticles (spherical shape, diameter 80–100 nanometres). The digital micrographs of the nuclei were made in 3 different time points: 15, 30 and 60 min after the treatment with IONPs, as well as in the control cells. A total of 120 nuclear structures (30 per sample) were analysed. Fractal analysis of nuclei was done in ImageJ software of the National Institutes of Health, (Bethesda, MD, USA). For each nuclear struct...
Source: Journal of Microscopy - May 23, 2017 Category: Laboratory Medicine Authors: D. NIKOLOVSKI, S. DUGALIC, I. PANTIC Tags: Original Article Source Type: research
TOC ‐ Issue Information
(Source: Journal of Microscopy)
Source: Journal of Microscopy - May 17, 2017 Category: Laboratory Medicine Tags: Issue Information Source Type: research
Three ‐dimensional microstructure characterisation of thermoplastic polyolefin blends
Summary
The size, shape and distribution of different phases in thermoplastic polyolefin (TPO) blends and composites are critical to the properties of the materials, but can be difficult to characterise. Here we report the combination of heavy metal staining and focused ion beam – scanning electron microscopy (FIB‐SEM) to reveal the three‐dimensional (3D) structure of an elastomer‐modified poly(propylene) and a talc filled elastomer‐modified poly(propylene). High‐quality, high‐resolution serial images were collected and the 3D structures were characterised quantitatively.
Lay description
Thermoplastic polyol...
Source: Journal of Microscopy - May 5, 2017 Category: Laboratory Medicine Authors: J. ‐C. LIN, Y. HUANG, J. HARRIS, B. WEINLANDER, M.A. JONES Tags: Original Article Source Type: research
Assessment of statistical agreement of three techniques for the study of cut marks: 3D digital microscope, laser scanning confocal microscopy and micro ‐photogrammetry
In this study, we analyse 26 experimental cut marks generated with a metal knife. The quantitative and qualitative information registered is analysed by means of standard multivariate statistics and geometric morphometrics to assess the similarities and differences obtained with the different methodologies.
Lay description
The study of anthropogenic marks on bone surfaces has become fundamental for the interpretation of archaeological sites and prehistoric butchery practices. Cut marks are one of the most common traces used in the identification of prehistoric human practices. Though theoretically cut marks are defined in...
Source: Journal of Microscopy - May 5, 2017 Category: Laboratory Medicine Authors: MIGUEL ÁNGEL MATÉ‐GONZÁLEZ, JULIA ARAMENDI, JOSÉ YRAVEDRA, RUTH BLASCO, JORDI ROSELL, DIEGO GONZÁLEZ‐AGUILERA, MANUEL DOMÍNGUEZ‐RODRIGO Tags: Original Article Source Type: research
