Differential interference contrast ‐photothermal microscopy in nanospace: impacts of systematic parameters
Summary
Differential interference contrast‐photothermal microscopy (DIC‐PTM), as a promising tool for trace analysis of nonfluorescent compounds, suffered low sensitivity in nanospace especially for aqueous samples, due to the poor thermophysical property of water and the unoptimised configuration. To improve its performance, a five‐layer DIC‐PTM model is built and influences of different parameters on the photothermal signal are investigated. The initial phase shift φ0 between two branches of the probe beam is found to be a key factor determining the detection sensitivity and response linearity: at a large φ0 (...
Source: Journal of Microscopy - August 16, 2017 Category: Laboratory Medicine Authors: M. LIU Tags: Original Article Source Type: research
Registration of phase ‐contrast images in propagation‐based X‐ray phase tomography
Summary
X‐ray phase tomography aims at reconstructing the 3D electron density distribution of an object. It offers enhanced sensitivity compared to attenuation‐based X‐ray absorption tomography. In propagation‐based methods, phase contrast is achieved by letting the beam propagate after interaction with the object. The phase shift is then retrieved at each projection angle, and subsequently used in tomographic reconstruction to obtain the refractive index decrement distribution, which is proportional to the electron density. Accurate phase retrieval is achieved by combining images at different propagation distances...
Source: Journal of Microscopy - August 16, 2017 Category: Laboratory Medicine Authors: L. WEBER, A. H ÄNSCH, U. WOLFRAM, A. PACUREANU, P. CLOETENS, F. PEYRIN, S. RIT, M. LANGER Tags: Original Article Source Type: research
Enhanced EDX images by fusion of multimodal SEM images using pansharpening techniques
Summary
The goal of this paper is to explore the potential interest of image fusion in the context of multimodal scanning electron microscope (SEM) imaging. In particular, we aim at merging the backscattered electron images that usually have a high spatial resolution but do not provide enough discriminative information to physically classify the nature of the sample, with energy‐dispersive X‐ray spectroscopy (EDX) images that have discriminative information but a lower spatial resolution. The produced images are named enhanced EDX. To achieve this goal, we have compared the results obtained with classical pansharpening...
Source: Journal of Microscopy - August 16, 2017 Category: Laboratory Medicine Authors: G. FRANCHI, J. ANGULO, M. MOREAUD, L. SORBIER Tags: Original Article Source Type: research
Automated segmentation and quantification of actin stress fibres undergoing experimentally induced changes
This article describes a method to teach the computer how to count and measure the stress fibers automatically, even if they are one above the other or bent to curves. We followed a novel strategy identifying stress fibers in an iterative way. This means the program starts to find the small and sharp stress fibers before it considers the thicker stress fibers, which are often more clumped together. Here one may think of the children's game “pick up sticks”, where it is a good tactic to first take out the sticks which are not clumped together.
At the end we demonstrate the capabilities of the presented algorithm by anal...
Source: Journal of Microscopy - August 14, 2017 Category: Laboratory Medicine Authors: H. ROGGE, N. ARTELT, N. ENDLICH, K. ENDLICH Tags: Original Article Source Type: research
TOC ‐ Issue Information
(Source: Journal of Microscopy)
Source: Journal of Microscopy - August 14, 2017 Category: Laboratory Medicine Tags: Issue Information Source Type: research
Robust fluorescent labelling of micropipettes for use in fluorescence microscopy: application to the observation of a mosquito borne parasite infection
Summary
The ability to monitor micropipette injections with a high‐resolution fluorescent microscope has utility for a variety of applications. Herein, different approaches were tested for creating broad‐band fluorescently labelled glass micropipettes including: UV cured glass glues, baked glass enamel containing fluorescent dyes as well as nanodiamonds attached during pipette formation in the microforge. The most robust and simplest approach was to use labelled baked enamel on the exterior of the pipette. This approach was tested using pipettes designed to mimic a mosquito proboscis for the injection of the malaria pa...
Source: Journal of Microscopy - August 10, 2017 Category: Laboratory Medicine Authors: AMANDA E. BALABAN, KEIR NEUMAN, PHOTINI SINNIS, ROBERT S. BALABAN Tags: Original Article Source Type: research
Application of micro ‐FTIR mapping and SEM to study compositional heterogeneity of siltstones: Example from the Late Devonian–Early Mississippian Middle Bakken Member
Summary
This paper explores the applicability of micro‐FTIR mapping to study heterogeneity of organic matter‐lean siltstones. Closely spaced samples of Late Devonian dolomitic siltstones of the Middle Bakken Member were analysed with micro‐FTIR, powder X‐ray diffraction, and scanning electron microscopy (SEM) to explore the distribution and chemical properties of organic matter (OM), muscovite/feldspar/clay group, carbonates, and quartz, and their influence on porosity and permeability of these rocks. Our results show that quartz is the dominant component of the samples, and the main mineralogical differences betwe...
Source: Journal of Microscopy - August 1, 2017 Category: Laboratory Medicine Authors: C. GASAWAY, M. MASTALERZ, F. KRAUSE, C. CLARKSON, C. DEBUHR Tags: Original Article Source Type: research
Textural pattern classification for oral squamous cell carcinoma
Summary
Despite being an area of cancer with highest worldwide incidence, oral cancer yet remains to be widely researched. Studies on computer‐aided analysis of pathological slides of oral cancer contribute a lot to the diagnosis and treatment of the disease. Some researches in this direction have been carried out on oral submucous fibrosis. In this work an approach for analysing abnormality based on textural features present in squamous cell carcinoma histological slides have been considered. Histogram and grey‐level co‐occurrence matrix approaches for extraction of textural features from biopsy images with normal a...
Source: Journal of Microscopy - August 1, 2017 Category: Laboratory Medicine Authors: T. Y. RAHMAN, L. B. MAHANTA, C. CHAKRABORTY, A. K. DAS, J. D. SARMA Tags: Original Article Source Type: research
Effects of donor and acceptor's fluorescence lifetimes on the method of applying F örster resonance energy transfer in STED microscopy
Summary
Förster resonance energy transfer (FRET) probes being used to improve the resolution of stimulated emission depletion (STED) microscopy are numerically discussed. Besides the FRET efficiency and the excitation intensity, the fluorescence lifetimes of donor and acceptor are found to be another key parameter for the resolution enhancement. Using samples of FRET pairs with shorter donor lifetime and longer acceptor lifetime enhances the nonlinearity of the donor fluorescence, which leads to an increased resolution. The numerical simulation shows that a double resolution improvement of STED microscopy can be achieved ...
Source: Journal of Microscopy - July 31, 2017 Category: Laboratory Medicine Authors: SUHUI DENG, JIANFANG CHEN, ZHAOSHUAI GAO, CHUNHAI FAN, QIURONG YAN, YUHAO WANG Tags: Original Article Source Type: research
Multichannel wide ‐field microscopic FRET imaging based on simultaneous spectral unmixing of excitation and emission spectra
Summary
Simultaneous spectral unmixing of excitation and emission spectra (ExEm unmixing) has inherent ability resolving spectral crosstalks, two key issues of quantitative fluorescence resonance energy transfer (FRET) measurement, of both the excitation and emission spectra between donor and acceptor without additional corrections. We here set up a filter‐based multichannel wide‐field microscope for ExEm unmixing‐based FRET imaging (m‐ExEm‐spFRET) containing a constant system correction factor (fsc) for a stable system. We performed m‐ExEm‐spFRET with four‐ and two‐wavelength excitation respectively on o...
Source: Journal of Microscopy - July 31, 2017 Category: Laboratory Medicine Authors: M. DU, Z. MAI, F. YANG, F. LIN, L. WEI, T. CHEN Tags: Original Article Source Type: research
Ten implementations of ptychography
Summary
Ptychography is an increasingly popular phase retrieval imaging technique, able to routinely deliver quantitative phase images with extended field of view at diffraction limited resolution. Different variants of this technique, like Bragg ptychography and Fourier ptychography, have also been developed and applied to various fields. Here we experimentally demonstrate 10 ways to implement the conventional real space transmission ptychography, and compare their properties to provide a guide to choosing the optimal setup for a specific application.
Lay description
Ptychography is a lensless imaging technique, able to ...
Source: Journal of Microscopy - July 31, 2017 Category: Laboratory Medicine Authors: PENG LI, ANDREW M. MAIDEN Tags: Original Article Source Type: research
Exploring the interior of cuticles and compressions of fossil plants by FIB ‐SEM milling and image microscopy
We present the first study of cuticles and compressions of fossil leaves by Focused Ion Beam Scanning Electron Microscopy (FIB‐SEM). Cavities preserved inside fossil leaf compressions corresponding to substomatal chambers have been observed for the first time and several new features were identified in the cross‐section cuts. These results open a new way in the investigation of the three‐dimensional structures of both micro‐ and nanostructural features of fossil plants. Moreover, the application of the FIB‐SEM technique to both fossils and extant plant remains represent a new source of taxonomical, palaeoenvironm...
Source: Journal of Microscopy - July 26, 2017 Category: Laboratory Medicine Authors: L. M. SENDER, I. ESCAPA, A. BENEDETTI, R. C ÚNEO, J. B. DIEZ Tags: Original Article Source Type: research
Plastic deformation mechanisms in a new Ni ‐base single crystal superalloy at room temperature
This study also provides new insights into understanding the interaction of matrix dislocations with γ′ precipitates and the relationship between the tensile strength and the activation of plastic deformation mechanisms in Ni‐base superalloys. (Source: Journal of Microscopy)
Source: Journal of Microscopy - July 19, 2017 Category: Laboratory Medicine Authors: P. ZHANG, Y. YUAN, Z. GAO, B. LI, G. YANG, X. SONG Tags: Original Article Source Type: research
TOC ‐ Issue Information
(Source: Journal of Microscopy)
Source: Journal of Microscopy - July 18, 2017 Category: Laboratory Medicine Tags: Issue Information Source Type: research
Enhancing image contrast of carbon nanotubes on cellular background using helium ion microscope by varying helium ion fluence
Summary
Carbon nanotubes (CNTs) have become an important nano entity for biomedical applications. Conventional methods of their imaging, often cannot be applied in biological samples due to an inadequate spatial resolution or poor contrast between the CNTs and the biological sample. Here we report a unique and effective detection method, which uses differences in conductivities of carbon nanotubes and HeLa cells. The technique involves the use of a helium ion microscope to image the sample with the surface charging artefacts created by the He+ and neutralised by electron flood gun. This enables us to obtain a few nanometre...
Source: Journal of Microscopy - July 13, 2017 Category: Laboratory Medicine Authors: M.M. DYKAS, K. PODDAR, S.L. YOONG, V. VISWANATHAN, S. MATHEW, A. PATRA, S. SAHA, G. PASTORIN, T. VENKATESAN Tags: Original Article Source Type: research
