scholarly journals 4f Koehler Transmitted Illumination Condenser for Teaching and Low-Cost Microscopic Imaging

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Jorge Madrid-Wolff ◽  
Manu Forero-Shelton
Keyword(s):  
Graduate Students ◽  
Cell Tracking ◽  
Low Cost ◽  
Light Sheet ◽  
Depth Of Field ◽  
Sample Analysis ◽  
Illumination System ◽  
Key Concepts ◽  
Illumination Method ◽  
Koehler Illumination

ABSTRACT Transmitted light imaging is an important tool in biophysics for applications that include sample analysis, recording samples whose viability is compromised by high levels of illumination (e.g., live cell tracking), and finding regions of interest in a sample. Koehler transillumination is a powerful illumination method used in commercial microscopes; yet commercial Koehler condensers are expensive, are difficult to integrate into tabletop systems, and make learning the concepts of Koehler illumination difficult because of their closed-box nature. Here, we show a protocol to build a simple 4f Koehler illumination system that offers advantages with respect to commercial condensers in terms of simplicity, cost, and compatibility with tabletop systems, such as open-source light sheet fluorescence microscopes. We include step-by-step instructions that can be followed by advanced undergraduate or graduate students without experience in optics on how to align and assemble the illuminator, along with a list of the necessary parts for assembly. We also include supplemental material that describes 4 supporting educational activities students can conduct with the apparatus and helps in the understanding of key concepts relevant to Koehler illumination and optics. The performance of the system is comparable to that of commercial condensers and significantly better, in terms of illumination homogeneity and depth of field (optical sections are possible), than that of LED flashlights, such as those found in low-cost diagnostic devices and tabletop systems.

Electron spectroscopic imaging and diffraction

1991 ◽  
Vol 49 ◽  
pp. 706-707
Author(s):  
M. Rühle ◽  
J. Mayer ◽  
J.C.H. Spence ◽  
J. Bihr ◽  
W. Probst ◽  
...  
Keyword(s):  
Materials Science ◽  
Electron Spectroscopic Imaging ◽  
Magnetic Filter ◽  
Magnetic Imaging ◽  
Illumination System ◽  
Probe Size ◽  
Diffraction Patterns ◽  
Fritz Haber ◽  
Koehler Illumination ◽  
First Time

A new Zeiss TEM with an imaging Omega filter is a fully digitized, side-entry, 120 kV TEM/STEM instrument for materials science. The machine possesses an Omega magnetic imaging energy filter (see Fig. 1) placed between the third and fourth projector lens. Lanio designed the filter and a prototype was built at the Fritz-Haber-Institut in Berlin, Germany. The imaging magnetic filter allows energy-filtered images or diffraction patterns to be recorded without scanning using efficient area detection. The energy dispersion at the exit slit (Fig. 1) results in ∼ 1.5 μm/eV which allows imaging with energy windows of ≤ 10 eV. The smallest probe size of the microscope is 1.6 nm and the Koehler illumination system is used for the first time in a TEM. Serial recording of EELS spectra with a resolution < 1 eV is possible. The digital control allows X,Y,Z coordinates and tilt settings to be stored and later recalled.

scholarly journals Awheel Along Europe’s Rivers: Geoarchaeological Trails for Cycling Geotourists

2018 ◽  
Vol 10 (1) ◽  
pp. 413-440
Author(s):  
Thomas A. Hose
Keyword(s):  
Roman Empire ◽  
Case Studies ◽  
Low Cost ◽  
Stone Age ◽  
Key Concepts ◽  
Review Study ◽  
Loess Deposits ◽  
River Valleys ◽  
Major Cycle ◽  
Current Provision

AbstractThis review study presents an overview of the potential for the development of geoarchaeological trails for leisure cyclists in Europe. It initially defines and discusses the underpinning key concepts and then examines the nature and main needs of leisure cyclists. It considers and recognises appropriate geo-interpretative themes, of geological/geomorphological and archaeological/historical interest, to employ in developing the trails. Noting that river valleys have long been natural route-ways for human expansion into Europe (as exemplified by the ‘Stone Age’ and the Roman Empire), and that many of today’s major cycle trails are beside rivers with loess deposits, a geoarchaeological geotourism strategy is considered in relation to them. Case studies of specific sites, from central southern England, the Middle Danube and Middle Rhine valleys, outline the current provision and the basis of the proposed trails. Finally, a common relatively low-cost, mixed media, geo-interpretative and promotional approach could generate the impetus to further develop the strategy is suggested.

scholarly journals Long-term in toto cell tracking using lightsheet microscopy of the zebrafish tailbud

2019 ◽  
Vol 3 ◽  
pp. 163
Author(s):  
Timothy Fulton ◽  
Martin O. Lenz ◽  
Leila Muresan ◽  
Toby Andrews ◽  
Courtney Lancaster ◽  
...  
Keyword(s):  
Temporal Resolution ◽  
Cell Tracking ◽  
Image Acquisition ◽  
Light Sheet ◽  
Field Of View ◽  
Image Capture ◽  
Acquisition Period ◽  
Global Movement ◽  
Microscope Stage

In toto light-sheet imaging allows the tracking of entire growing tissues with high spatial and temporal resolution for many hours. However, this technology requires a sample to be immobilised to ensure that the tissue of interest remains within the field of view throughout the image acquisition period. We have developed a method of mounting and image capture for long-term light-sheet imaging of a growing zebrafish tailbud from the 18 somite stage through to the end of somitogenesis. By tracking the global movement of the tailbud during image acquisition and feeding this back to the microscope stage, we are able to ensure that the growing tissue remains within the field of view throughout image acquisition. Here, we present three representative datasets of embryos in which all nuclei are labelled and tracked until the completion of somitogenesis.

A Bi-Frequency Co-Linear Array Transducer for Biomedical Ultrasound Imaging

2014 ◽  
Author(s):  
Zhuochen Wang ◽  
Sibo Li ◽  
Ruibin Liu ◽  
Xuecang Geng ◽  
Xiaoning Jiang
Keyword(s):  
Real Time ◽  
Ultrasound Imaging ◽  
Linear Array ◽  
Low Cost ◽  
Large Field ◽  
Depth Of Field ◽  
Frequency Range ◽  
Non Invasive ◽  
Array Transducer ◽  
Conventional Ultrasound

Ultrasound imaging with high resolution and large field of depth has been increasingly adopted in medical diagnosis, surgery guidance and treatment assessment because of its relatively low cost, non-invasive and capability of real-time imaging. There is always a tradeoff between the resolution and depth of field in ultrasound imaging. Conventional ultrasound works at a particular frequency, with −6 dB fractional bandwidth of < 100%, limiting the resolution or field of depth in many ultrasound imaging cases. In this paper, a bi-frequency co-linear array covering a frequency range of 5 MHz-20 MHz was investigated to meet the requirements of resolution and depth of field for a broad range of ultrasound imaging applications. As a demonstration, a 31-element bi-frequency co-linear array was designed and fabricated, followed by element characterization and real time sectorial scan (S-scan) phantom imaging using a Verasonics system.

scholarly journals ENHANCING CLOSE-UP IMAGE BASED 3D DIGITISATION WITH FOCUS STACKING

2017 ◽  
Vol XLII-2/W5 ◽  
pp. 421-425 ◽  
Author(s):  
G. Kontogianni ◽  
R. Chliverou ◽  
A. Koutsoudis ◽  
G. Pavlidis ◽  
A. Georgopoulos
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Reference Model ◽  
Low Cost ◽  
3D Models ◽  
Depth Of Field ◽  
Colour Changes ◽  
Normal Lens ◽  
Structured Light System ◽  
3D Digitisation

The 3D digitisation of small artefacts is a very complicated procedure because of their complex morphological feature structures, concavities, rich decorations, high frequency of colour changes in texture, increased accuracy requirements etc. Image-based methods present a low cost, fast and effective alternative because laser scanning does not meet the accuracy requirements in general. A shallow Depth of Field (DoF) affects the image-based 3D reconstruction and especially the point matching procedure. This is visible not only in the total number of corresponding points but also in the resolution of the produced 3D model. The extension of the DoF is a very important task that should be incorporated in the data collection to attain a better quality of the image set and a better 3D model. An extension of the DoF can be achieved with many methods and especially with the use of the focus stacking technique. In this paper, the focus stacking technique was tested in a real-world experiment to digitise a museum artefact in 3D. The experiment conditions include the use of a full frame camera equipped with a normal lens (50mm), with the camera being placed close to the object. The artefact has already been digitised with a structured light system and that model served as the reference model in which 3D models were compared and the results were presented.

scholarly journals UC2 – A Versatile and Customizable low-cost 3D-printed Optical Open-Standard for microscopic imaging

2020 ◽  
Author(s):  
Benedict Diederich ◽  
René Lachmann ◽  
Swen Carlstedt ◽  
Barbora Marsikova ◽  
Haoran Wang ◽  
...  
Keyword(s):  
Open Access ◽  
Low Cost ◽  
Stress Test ◽  
Light Sheet ◽  
Development Cycle ◽  
Drosophila Larvae ◽  
Open Standard ◽  
Fluorescence Light ◽  
3D Printed ◽  
3D Volume

AbstractWith UC2 (You-See-Too) we present an inexpensive 3D-printed microscopy toolbox. The system is based on concepts of modular development, rapid-prototyping and all-time accessibility using widely available off-the-shelf optic and electronic components. We aim to democratize microscopy, reduce the reproduction crisis and enhance trust into science by making it available to everyone via an open-access public repository. Due to its versatility the aim is to boost creativity and non-conventional approaches. In this paper, we demonstrate a development cycle from basic blocks to different microscopic techniques. First, we build a bright-field system and stress-test it by observing macrophage cell differentiation, apoptosis and proliferation incubator-enclosed for seven days with automatic focussing to minimize axial drift. We prove versatility by assembling a system using the same components to a fully working fluorescence light-sheet system and acquire a 3D volume of a GFP-expressing living drosophila larvae. Finally, we sketch and demonstrate further possible setups to draw a picture on how the system can be used for reproducible prototyping in scientific research. All design files for replicating the experimental setups are provided via an open-access online repository (https://github.com/bionanoimaging/UC2-GIT) to foster widespread use.

scholarly journals An Open-Hardware sample mounting solution for inverted light-sheet microscopes with large detection objective lenses

2019 ◽  
Author(s):  
Craig T. Russell ◽  
Eric J. Rees
Keyword(s):  
Thin Sheet ◽  
Light Sheet ◽  
Depth Of Field ◽  
Standard Methods ◽  
Open Hardware ◽  
Light Sheet Microscopy

Implementations of light-sheet microscopes are often incompatible with standard methods of sample mounting. Light-sheet microscopy uses orthogonal illumination and detection to create a thin sheet of light which does not illuminate the sample outside of the depth of field of the detection axis. Typically, this configuration involves a pair of orthogonal objectives which constrains the positioning of a length of coverslips or microscopes in range of the detection objective. We present an open-hardware (1, 2) sample mounting system for light-sheet microscopes using large detection objectives.

scholarly journals Feasibility Of Establishing An Enzyme-Linked Immunosorbent Assay (ELISA) Laboratory For The Detection Of Dioxins In Economically Marginalized And Developed Countries

2021 ◽  
Author(s):  
Adrienne K. Lee
Keyword(s):  
Mass Spectrometry ◽  
Technology Transfer ◽  
Contaminated Soil ◽  
Low Cost ◽  
Health And Safety ◽  
Developed Countries ◽  
Enzyme Linked Immunosorbent Assay ◽  
Sample Analysis ◽  
Economically Marginalized ◽  
Accessible Form

Finding a low cost and accessible means of detecting for dioxins in contaminated soil is a necessary step to ensure the health and safety of humans and the environment worldwide. Conventional technologies based on mass spectrometry are expensive and inaccessible. A minimally resourced laboratory and the use of ELISA will be discussed as a feasible, accessible, low cost alternative. The correlation between a minimally resourced laboratory (Ryerson University) and a fully resourced laboratory (Ontario Ministry of the Environment) was strong (n=13, r²=0.888, slope=0.87). To demonstrate the functionality of the minimally resourced laboratory, a supplemental site was characterized using ELISA. Results from the Ryerson and OMOE laboratories produced similar dioxin concentrations of undetectable to 120.26pgTEQg⁻¹ and 32.38 to 163.2pgTEQg⁻¹, respectively. This study illustrates an alternative for evaluating contaminated soil that could serve as a technology transfer for marginalized economies, and provide an accessible form of sample analysis in developed countries.

scholarly journals Rehabilitation Walker with Standing-Assistance Device

2007 ◽  
Vol 19 (6) ◽  
pp. 604-611 ◽  
Author(s):  
Daisuke Chugo ◽  
◽  
Wataru Matsuoka ◽  
Songmin Jia ◽  
Kunikatsu Takase
Keyword(s):  
Computer Simulation ◽  
Position Control ◽  
Low Cost ◽  
Key Concepts ◽  
Power Assistance

The walker with power assistance for standing we propose focuses on home use for those requiring daily assistance. Our key concepts involve (1) a new assistance manipulator with four parallel linkages using smaller actuators and rigid with lighter linkages than general manipulators, providing compact assistance at low cost; and (2) a combination of force and position control. Based on the user’s posture while standing, our proposed control selects appropriate control using the reference of standing based on typical standing by nursing specialists for realizing natural assistance. The conductance of our proposed assistance is verified by computer simulation and experiments using a prototype.

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