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Journal of Microscopy

A C Chang, B H Liu, P L Shao, J D Liao
The multilayer skin provides the physical resistance and strength against the environmental attacks, and consequently plays a significant role in maintaining the mammalian health. Currently, optical microscopy (OM) is the most common method for the research related to skin tissues while with the drawbacks including the possibility of changing the native morphology of the sample with the addition of the chemical or immunological staining and the restricted resolution of images for the direct observation of the tissue structures...
March 23, 2017: Journal of Microscopy
R Browning
The spatial resolution of the vector potential photoelectron microscope is determined by the maximum size of the cyclotron orbits of the imaged electrons at the surface of a sample. It is straightforward to calculate the spatial resolution for any imaged electron energy given the magnetic field strength. However, in low-energy secondary photoelectron images from an aluminium-calcium metal matrix alloy, we find the apparent spatial resolution is significantly higher than expected. A possible explanation for the enhanced resolution is that the low-energy cyclotron orbits are distorted when passing from one area of work function to another and the image is dependent on the surface field distribution...
March 22, 2017: Journal of Microscopy
John M Murray
The ability to replace genes coding for cellular proteins with DNA that codes for fluorescent protein-tagged versions opens the way to counting the number of molecules of each protein component of macromolecular assemblies in vivo by measuring fluorescence microscopically. Converting fluorescence to absolute numbers of molecules requires a fluorescent standard whose molecular composition is known precisely. In this report, the construction, properties and mode of using a set of fluorescence calibration standards are described...
March 22, 2017: Journal of Microscopy
Y Sakalli, R Trettin
Tricalciumsilicate (C3 S, Alite) is the major component of the Portland cement clinker. Hydration of Alite is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The mechanism of the hydration of C3 S is very complicated and not yet fully understood. There are different models describing the hydration of C3 S in various ways. In this work for a better understanding of hydration mechanism, the hydrated C3 S was investigated by using the transmission electron microscope (TEM) and for the first time, the samples for the investigations were prepared by using of focused ion beam from sintered pellets of C3 S...
March 22, 2017: Journal of Microscopy
A D Ball, P A Job, A E L Walker
The method we present here uses a scanning electron microscope programmed via macros to automatically capture dozens of images at suitable angles to generate accurate, detailed three-dimensional (3D) surface models with micron-scale resolution. We demonstrate that it is possible to use these Scanning Electron Microscope (SEM) images in conjunction with commercially available software originally developed for photogrammetry reconstructions from Digital Single Lens Reflex (DSLR) cameras and to reconstruct 3D models of the specimen...
March 22, 2017: Journal of Microscopy
W Colomb, J Czerski, J D Sau, S K Sarkar
Fiducial markers are used to correct the microscope drift and should be photostable, be usable at multiple wavelengths and be compatible for multimodal imaging. Fiducial markers such as beads, gold nanoparticles, microfabricated patterns and organic fluorophores lack one or more of these criteria. Moreover, the localization accuracy and drift correction can be degraded by other fluorophores, instrument noise and artefacts due to image processing and tracking algorithms. Estimating mechanical drift by assuming Gaussian distributed noise is not suitable under these circumstances...
March 22, 2017: Journal of Microscopy
H Yuan, E Brodu, C Chen, E Bouzy, J-J Fundenberger, L S Toth
A new configuration for Transmission Kikuchi Diffraction (TKD) in a scanning electron microscope is presented; called 'on-axis TKD'. Compared to the usual off-axis configuration, the scintillator is placed perpendicular to the incident beam under the electron-transparent sample, not in vertical position. In this way, the setup benefits from intense forward scattered electrons enabling short acquisition times. At equivalent diffraction pattern quality, the electron dose needed on the sample is estimated to be 20 times lower in comparison to the off-axis configuration...
March 22, 2017: Journal of Microscopy
T Mungle, S Tewary, D K DAS, I Arun, B Basak, S Agarwal, R Ahmed, S Chatterjee, C Chakraborty
Molecular pathology, especially immunohistochemistry, plays an important role in evaluating hormone receptor status along with diagnosis of breast cancer. Time-consumption and inter-/intraobserver variability are major hindrances for evaluating the receptor score. In view of this, the paper proposes an automated Allred Scoring methodology for estrogen receptor (ER). White balancing is used to normalize the colour image taking into consideration colour variation during staining in different labs. Markov random field model with expectation-maximization optimization is employed to segment the ER cells...
March 20, 2017: Journal of Microscopy
Xiaohua He, Bin Liu
Oolong tea extract (OTE) was assessed for its potential as an electron stain to substitute for uranyl acetate (UA) in transmission electron microscopy (TEM). A comparative analysis of the ultrastructures of biological specimens (i.e. compound eye and sciatic nerve tissue) stained by different methods (UA and 0.1% OTE) has been performed. Results revealed that there was no significant difference between the OTE double staining method and the traditional double staining method, except the contrast in the OTE method was slightly lower than the UA method...
March 20, 2017: Journal of Microscopy
V Marcos-Garcés, M Harvat, P Molina Aguilar, A Ferrández Izquierdo, A Ruiz-Saurí
Measurement of collagen bundle orientation in histopathological samples is a widely used and useful technique in many research and clinical scenarios. Fourier analysis is the preferred method for performing this measurement, but the most appropriate staining and microscopy technique remains unclear. Some authors advocate the use of Haematoxylin-Eosin (H&E) and confocal microscopy, but there are no studies comparing this technique with other classical collagen stainings. In our study, 46 human skin samples were collected, processed for histological analysis and stained with Masson's trichrome, Picrosirius red and H&E...
March 20, 2017: Journal of Microscopy
C X Liao, Z Y Wang, Y Zhou, L Q Zhou, X Q Zhu, W G Liu, J X Chen
The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column...
March 20, 2017: Journal of Microscopy
L P Deo, M J Kaufman, B Wang, S Nikodemski, M F DE Oliveira
The properties of metallic alloys can be significantly improved by developing non-equilibrium phases in the microstructures through rapid solidification techniques, thus the characterisation of these unusual structures is extremely important. In this research, the microstructures of three rapidly quenched alloys, namely Ni65.2 Nb33.8 Zr1.0 , Ni54.8 Nb31.1 Zr14.1 and Ni54.8 Nb21.6 Zr23.6 (at. %) were investigated in greater detail in order to determine the structures and compositions of their crystalline phases...
March 15, 2017: Journal of Microscopy
H X Wang, W Zhang, N E Drewett, H B Zhang, K K Huang, S H Feng, X L Li, J Kim, S Yoo, T Deng, S J Liu, D Wang, W T Zheng
The use of transition metal oxides and hydroxides in supercapacitors can yield high specific capacity electrodes. However, the effect of interaction between active material and current collector has remained unexplored. Here the behaviour of electrodeposited hexagonal cobalt hydroxide nanosheets on a variety of substrates was investigated, and the resulting valence bonding, morphological evolutions and phase transformations examined. It is shown that the electrochemical activity of the face centred cubic (FCC) Ni substrate dramatically decreases cyclability, the FCC Cu substrate also demonstrates decreased performance, and hexagonal carbon nanofibre (CNF) and Ti substrates exhibit far more stability...
March 15, 2017: Journal of Microscopy
J Liu, X You, Y Wang, K Gu, C Liu, J Tan
A circular-route scanning method called α-β circular scanning is proposed and realized using sinusoidal signals with a constant phase difference of π/2. Experiments show that the circular scanning range of α-β circular scanning is 57% greater than the rectangular scanning range of raster scanning within an effective optical field of view. Moreover, the scanning speed is improved by 7.8% over raster scanning because the whole sine signal is utilized in α-β circular scanning whereas the flyback area of the saw-tooth signal needs to be discarded in raster scanning...
March 15, 2017: Journal of Microscopy
A F Mark, W Li, S Sharples, P J Withers
Our aim was to establish the capability of spatially resolved acoustic spectroscopy (SRAS) to map grain orientations and the anisotropy in stiffness at the sub-mm to micron scale by comparing the method with electron backscatter diffraction (EBSD) undertaken within a scanning electron microscope. In the former the grain orientations are deduced by measuring the spatial variation in elastic modulus; conversely, in EBSD the elastic anisotropy is deduced from direct measurements of the crystal orientations. The two test-cases comprise mapping the fusion zones for large TIG and MMA welds in thick power plant austenitic and ferritic steels, respectively; these are technologically important because, among other things, elastic anisotropy can cause ultrasonic weld inspection methods to become inaccurate because it causes bending in the paths of sound waves...
March 15, 2017: Journal of Microscopy
C M Gabbott, Z X Zhou, G X Han, T Sun
At the core of translational challenges in tissue engineering is the mechanistic understanding of the underpinning biological processes and the complex relationships among components at different levels, which is a challenging task due to the limitations of current tissue culture and assessment methodologies. Therefore, we proposed a novel scale-down strategy to deconstruct complex biomatrices into elementary building blocks, which were resembled by thin modular substrate and then evaluated separately in miniaturised bioreactors using various conventional microscopes...
March 15, 2017: Journal of Microscopy
H-T Liu, W-L Lin, Y-L Feng, Y Lin, Y-C Chen
Application of light-emitting diodes (LEDs) in frequency-domain fluorescence lifetime imaging microscopy (FLIM) has been limited by the trade-off between modulation frequency and illumination intensity of LEDs, which affects the signal-to-noise ratio in fluorescence lifetime measurements. To increase modulation frequency without sacrificing output power of LEDs, we propose to use LEDs with multiple dice connected in series. The LED capacitance was reduced with series connection; therefore, the frequency response of multidie LED was significantly increased...
March 15, 2017: Journal of Microscopy
J Everaerts, B Verlinden, M Wevers
In the very high cycle fatigue regime, internal crack initiation can occur in Ti-6Al-4V because of the formation of facets, which are α grains that have fractured in a transcrystalline and planar manner. Because this crack initiation phase occupies most of the fatigue life, it is essential to understand which mechanisms lead to facet formation. Fatigue tests have been performed on drawn and heat-treated Ti-6Al-4V wires, and the facets at internal crack initiation sites have been analysed in detail in terms of their appearance, their spatial orientation and their crystallographic orientation...
March 15, 2017: Journal of Microscopy
S Handschuh, C J Beisser, B Ruthensteiner, B D Metscher
Dual-energy computed tomography (DECT) uses two different x-ray energy spectra in order to differentiate between tissues, materials or elements in a single sample or patient. DECT is becoming increasingly popular in clinical imaging and preclinical in vivo imaging of small animal models, but there have been only very few reports on ex vivo DECT of biological samples at microscopic resolutions. The present study has three main aims. First, we explore the potential of microscopic DECT (microDECT) for delivering isotropic multichannel 3D images of fixed biological samples with standard commercial laboratory-based microCT setups at spatial resolutions reaching below 10 μm...
March 7, 2017: Journal of Microscopy
Hưng-Xuân Trịnh, Shyh-Tsong Lin, Liang-Chia Chen, Sheng-Lih Yeh, Chin-Sheng Chen, Hong-Hai Hoang
A shearing interference microscope using a Savart prism as the shear plate is proposed for inspecting step-heights. Where the light beam propagates through the Savart prism and microscopic system to illuminate the sample, it then turns back to re-pass through the Savart prism and microscopic system to generate a shearing interference pattern on the camera. Two measurement modes, phase-shifting and phase-scanning, can be utilized to determine the depths of the step-heights on the sample. The first mode, which employs a narrowband source, is based on the five-step phase-shifting algorithm and has a measurement range of a quarter-wavelength...
March 7, 2017: Journal of Microscopy
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