The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Richard M Erry - One of the best experts on this subject based on the ideXlab platform.
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a simple low cost device enables four epi illumination techniques on standard Light Microscopes
Scientific Reports, 2016Co-Authors: Robe Ishmukhametov, Aida N Russell, Richard J Wheele, Ashley L Nord, Richard M ErryAbstract:Back-scattering darkfield (BSDF), epi-fluorescence (EF), interference reflection contrast (IRC), and darkfield surface reflection (DFSR) are advanced but expensive Light microscopy techniques with limited availability. Here we show a simple optical design that combines these four techniques in a simple low-cost miniature epi-illuminator, which inserts into the differential interference-contrast (DIC) slider bay of a commercial microscope, without further additions required. We demonstrate with this device: 1) BSDF-based detection of Malarial parasites inside unstained human erythrocytes; 2) EF imaging with and without dichroic components, including detection of DAPI-stained Leishmania parasite without using excitation or emission filters; 3) RIC of black lipid membranes and other thin films, and 4) DFSR of patterned opaque and transparent surfaces. We believe that our design can expand the functionality of commercial bright field Microscopes, provide easy field detection of parasites and be of interest to many users of Light microscopy.
Reinhard Wirth - One of the best experts on this subject based on the ideXlab platform.
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the temperature gradient forming device an accessory unit for normal Light Microscopes to study the biology of hyperthermophilic microorganisms
Applied and Environmental Microbiology, 2014Co-Authors: Maximilia Mora, Anne Ellack, Matthias Ugele, Joha Hopf, Reinhard WirthAbstract:ABSTRACT To date, the behavior of hyperthermophilic microorganisms in their biotope has been studied only to a limited degree; this is especially true for motility. One reason for this lack of knowledge is the requirement for high-temperature microscopy—combined, in most cases, with the need for observations under strictly anaerobic conditions—for such studies. We have developed a custom-made, low-budget device that, for the first time, allows analyses in temperature gradients up to 40°C over a distance of just 2 cm (a biotope-relevant distance) with heating rates up to ∼5°C/s. Our temperature gradient-forming device can convert any upright Light microscope into one that works at temperatures as high as 110°C. Data obtained by use of this apparatus show how very well hyperthermophiles are adapted to their biotope: they can react within seconds to elevated temperatures by starting motility—even after 9 months of storage in the cold. Using the temperature gradient-forming device, we determined the temperature ranges for swimming, and the swimming speeds, of 15 selected species of the genus Thermococcus within a few months, related these findings to the presence of cell surface appendages, and obtained the first evidence for thermotaxis in Archaea.
Enrico Lucarelli - One of the best experts on this subject based on the ideXlab platform.
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automated image mosaics by non automated Light Microscopes the micromos software tool
Journal of Microscopy, 2013Co-Authors: Filippo Piccinini, Alessandro Evilacqua, Enrico LucarelliAbstract:Summary Light widefield Microscopes and digital imaging are the basis for most of the analyses performed in every biological laboratory. In particular, the microscope's user is typically interested in acquiring high-detailed images for analysing observed cells and tissues, meanwhile being representative of a wide area to have reliable statistics. The microscopist has to choose between higher magnification factor and extension of the observed area, due to the finite size of the camera's field of view. To overcome the need of arrangement, mosaicing techniques have been developed in the past decades for increasing the camera's field of view by stitching together more images. Nevertheless, these approaches typically work in batch mode and rely on motorized Microscopes. Or alternatively, the methods are conceived just to provide visually pleasant mosaics not suitable for quantitative analyses. This work presents a tool for building mosaics of images acquired with nonautomated Light Microscopes. The method proposed is based on visual information only and the mosaics are built by incrementally stitching couples of images, making the approach available also for online applications. Seams in the stitching regions as well as tonal inhomogeneities are corrected by compensating the vignetting effect. In the experiments performed, we tested different registration approaches, confirming that the translation model is not always the best, despite the fact that the motion of the sample holder of the microscope is apparently translational and typically considered as such. The method's implementation is freely distributed as an open source tool called MicroMos. Its usability makes building mosaics of microscope images at subpixel accuracy easier. Furthermore, optional parameters for building mosaics according to different strategies make MicroMos an easy and reliable tool to compare different registration approaches, warping models and tonal corrections.
Vijay Kumar - One of the best experts on this subject based on the ideXlab platform.
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automated biomanipulation of single cells using magnetic microrobots
The International Journal of Robotics Research, 2013Co-Authors: Edward B Steager, Mahmut Selman Sakar, Ceridwen Magee, Monroe Kennedy, Anthony Cowley, Vijay KumarAbstract:Transport of individual cells or chemical payloads on a subcellular scale is an enabling tool for the study of cellular communication, cell migration, and other localized phenomena. We present a magnetically actuated robotic system capable of fully automated manipulation of cells and microbeads. Our strategy uses autofluorescent robotic transporters and fluorescently labeled microbeads to aid tracking and control in optically obstructed environments. We demonstrate automated delivery of microbeads infused with chemicals to specified positions on neurons. This system is compatible with standard upright and inverted Light Microscopes and is capable of applying forces less than 1 pN for precision positioning tasks.
H Fissan - One of the best experts on this subject based on the ideXlab platform.
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development of an electrostatic precipitator for off line particle analysis
Aerosol Science and Technology, 1999Co-Authors: J Dixkens, H FissanAbstract:Due to the lake of in-situ aerosol particle analysis systems, aerosol samples are taken and analyzed off-line. For detailed analysis of particle properties such as shape, morphology, and composition, off-line operating analytical tools like Light Microscopes, scanning electron Microscopes (SEM), total reflection x-ray fluorescence (TXRF), and so on are used. The analysis must be performed on a representative sample of particles homogeneously deposited on a flat sample plate. This avoids sample preparation steps which may change the sample. In this paper we describe the design, construction, and evaluation of a continuous sampling device that deposits gasborne particles on an analytically suitable sample plate. The collection efficiency and the deposition pattern were optimized using a numerical model and experiments. It turned out that representative samples appropriate for further analysis can be taken in the particle size range from 0.03 mu m < Dp < 10 mu m. Additionally, the sampling efficiency was inv...