The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform

Oliver Biehlmaier - One of the best experts on this subject based on the ideXlab platform.

  • Using the NoiSee workflow to Measure Signal-to-noise ratios of confocal microscopes
    Scientific Reports, 2019
    Co-Authors: Alexia Ferrand, Kai D. Schleicher, Nikolaus Ehrenfeuchter, Wolf Heusermann, Oliver Biehlmaier
    Abstract:

    Confocal microscopy is used today on a daily basis in life science labs. This “routine” technique contributes to the progress of scientific projects across many fields by revealing structural details and molecular localization, but researchers need to be aware that detection efficiency and emission light path performance is of major influence in the confocal image quality. By design, a large portion of the Signal is discarded in confocal imaging, leading to a decreased Signal-to-noise ratio (SNR) which in turn limits resolution. A well-aligned system and high performance detectors are needed in order to generate an image of best quality. However, a convenient method to address system status and performance on the emission side is still lacking. Here, we present a complete method to assess microscope and emission light path performance in terms of SNR, with a comprehensive protocol alongside NoiSee, an easy-to-use macro for Fiji (available via the corresponding update site). We used this method to compare several confocal systems in our facility on biological samples under typical imaging conditions. Our method reveals differences in microscope performance and highlights the various detector types used (multialkali photomultiplier tube (PMT), gallium arsenide phosphide (GaAsP) PMT, and Hybrid detector). Altogether, our method will provide useful information to research groups and facilities to diagnose their confocal microscopes.

Seiji Ogawa - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of ultra fast Signal progression related to face processing by 7t fmri
    Human Brain Mapping, 2020
    Co-Authors: Uksu Choi, Yulwan Sung, Seiji Ogawa
    Abstract:

    Given that the brain is a dynamic system, the temporal characteristics of brain function are important. Previous functional magnetic resonance imaging (fMRI) studies have attempted to overcome the limitations of temporal resolution to investigate dynamic states of brain activity. However, finding an fMRI method with sufficient temporal resolution to keep up with the progress of neuronal Signals in the brain is challenging. This study aimed to detect between-hemisphere Signal progression, occurring on a timescale of tens of milliseconds, in the ventral brain regions involved in face processing. To this end, we devised an inter-stimulus interval (ISI) stimulation scheme and used a 7T MRI system to obtain fMRI Signals with a high Signal-to-noise ratio. We conducted two experiments: one to Measure Signal suppression depending on the ISI and another to Measure the relationship between the amount of suppression and the ISI. These two experiments enabled us to Measure the Signal transfer time from a brain region in the ventral visual stream to its counterpart in the opposite hemisphere through the corpus callosum. These findings demonstrate the feasibility of using fMRI to Measure ultra-fast Signals (tens of milliseconds) and could facilitate the elucidation of further aspects of dynamic brain function.

Alexia Ferrand - One of the best experts on this subject based on the ideXlab platform.

  • Using the NoiSee workflow to Measure Signal-to-noise ratios of confocal microscopes
    Scientific Reports, 2019
    Co-Authors: Alexia Ferrand, Kai D. Schleicher, Nikolaus Ehrenfeuchter, Wolf Heusermann, Oliver Biehlmaier
    Abstract:

    Confocal microscopy is used today on a daily basis in life science labs. This “routine” technique contributes to the progress of scientific projects across many fields by revealing structural details and molecular localization, but researchers need to be aware that detection efficiency and emission light path performance is of major influence in the confocal image quality. By design, a large portion of the Signal is discarded in confocal imaging, leading to a decreased Signal-to-noise ratio (SNR) which in turn limits resolution. A well-aligned system and high performance detectors are needed in order to generate an image of best quality. However, a convenient method to address system status and performance on the emission side is still lacking. Here, we present a complete method to assess microscope and emission light path performance in terms of SNR, with a comprehensive protocol alongside NoiSee, an easy-to-use macro for Fiji (available via the corresponding update site). We used this method to compare several confocal systems in our facility on biological samples under typical imaging conditions. Our method reveals differences in microscope performance and highlights the various detector types used (multialkali photomultiplier tube (PMT), gallium arsenide phosphide (GaAsP) PMT, and Hybrid detector). Altogether, our method will provide useful information to research groups and facilities to diagnose their confocal microscopes.

Uksu Choi - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of ultra fast Signal progression related to face processing by 7t fmri
    Human Brain Mapping, 2020
    Co-Authors: Uksu Choi, Yulwan Sung, Seiji Ogawa
    Abstract:

    Given that the brain is a dynamic system, the temporal characteristics of brain function are important. Previous functional magnetic resonance imaging (fMRI) studies have attempted to overcome the limitations of temporal resolution to investigate dynamic states of brain activity. However, finding an fMRI method with sufficient temporal resolution to keep up with the progress of neuronal Signals in the brain is challenging. This study aimed to detect between-hemisphere Signal progression, occurring on a timescale of tens of milliseconds, in the ventral brain regions involved in face processing. To this end, we devised an inter-stimulus interval (ISI) stimulation scheme and used a 7T MRI system to obtain fMRI Signals with a high Signal-to-noise ratio. We conducted two experiments: one to Measure Signal suppression depending on the ISI and another to Measure the relationship between the amount of suppression and the ISI. These two experiments enabled us to Measure the Signal transfer time from a brain region in the ventral visual stream to its counterpart in the opposite hemisphere through the corpus callosum. These findings demonstrate the feasibility of using fMRI to Measure ultra-fast Signals (tens of milliseconds) and could facilitate the elucidation of further aspects of dynamic brain function.

Kai D. Schleicher - One of the best experts on this subject based on the ideXlab platform.

  • Using the NoiSee workflow to Measure Signal-to-noise ratios of confocal microscopes
    Scientific Reports, 2019
    Co-Authors: Alexia Ferrand, Kai D. Schleicher, Nikolaus Ehrenfeuchter, Wolf Heusermann, Oliver Biehlmaier
    Abstract:

    Confocal microscopy is used today on a daily basis in life science labs. This “routine” technique contributes to the progress of scientific projects across many fields by revealing structural details and molecular localization, but researchers need to be aware that detection efficiency and emission light path performance is of major influence in the confocal image quality. By design, a large portion of the Signal is discarded in confocal imaging, leading to a decreased Signal-to-noise ratio (SNR) which in turn limits resolution. A well-aligned system and high performance detectors are needed in order to generate an image of best quality. However, a convenient method to address system status and performance on the emission side is still lacking. Here, we present a complete method to assess microscope and emission light path performance in terms of SNR, with a comprehensive protocol alongside NoiSee, an easy-to-use macro for Fiji (available via the corresponding update site). We used this method to compare several confocal systems in our facility on biological samples under typical imaging conditions. Our method reveals differences in microscope performance and highlights the various detector types used (multialkali photomultiplier tube (PMT), gallium arsenide phosphide (GaAsP) PMT, and Hybrid detector). Altogether, our method will provide useful information to research groups and facilities to diagnose their confocal microscopes.