scholarly journals Divergent excitation two photon microscopy for 3D random access mesoscale imaging at single cell resolution

2019 ◽  
Author(s):  
FK Janiak ◽  
P Bartel ◽  
MR Bale ◽  
T Yoshimatsu ◽  
E Komulainen ◽  
...  
Keyword(s):  
Single Cell ◽  
Neuronal Activity ◽  
Low Cost ◽  
Three Dimensional ◽  
Random Access ◽  
Field Of View ◽  
Three Dimensions ◽  
Two Photon ◽  
Wide Range ◽  
Effective Excitation

ABSTACTIn neuroscience, diffraction limited two-photon (2P) microscopy is a cornerstone technique that permits minimally invasive optical monitoring of neuronal activity. However, most conventional 2P microscopes impose significant constraints on the size of the imaging field-of-view and the specific shape of the effective excitation volume, thus limiting the scope of biological questions that can be addressed and the information obtainable. Here, employing ‘divergent beam optics’ (DBO), we present an ultra-low-cost, easily implemented and flexible solution to address these limitations, offering a several-fold expanded three-dimensional field of view that also maintains single-cell resolution. We show that this implementation increases both the space-bandwidth product and effective excitation power, and allows for straight-forward tailoring of the point-spread-function. Moreover, rapid laser-focus control via an electrically tunable lens now allows near-simultaneous imaging of remote regions separated in three dimensions and permits the bending of imaging planes to follow natural curvatures in biological structures. Crucially, our core design is readily implemented (and reversed) within a matter of hours, and fully compatible with a wide range of existing 2P customizations, making it highly suitable as a base platform for further development. We demonstrate the application of our system for imaging neuronal activity in a variety of examples in mice, zebrafish and fruit flies.

Non-Telecentric 2P microscopy for 3D random access mesoscale imaging at single cell resolution

2020 ◽  
Author(s):  
Filip Janiak ◽  
Philipp Bartel ◽  
Michael Bale ◽  
Takeshi Yoshimatsu ◽  
Emilia Komulainen ◽  
...  
Keyword(s):  
Single Cell ◽  
Neuronal Activity ◽  
Low Cost ◽  
Optical Design ◽  
Random Access ◽  
Field Of View ◽  
Three Dimensions ◽  
Image Brightness ◽  
Wide Range ◽  
Effective Excitation

Abstract In neuroscience, diffraction limited two-photon (2P) microscopy is a cornerstone technique that permits minimally invasive optical monitoring of neuronal activity. However, most conventional 2P microscopes impose significant constraints on the size of the imaging field-of-view and the specific shape of the effective excitation volume, thus limiting the scope of biological questions that can be addressed and the information obtainable. Here, employing a non-telecentric (nTC) optical design, we present an ultra-low-cost, easily implemented and flexible solution to address these limitations, offering a several-fold expanded three-dimensional field of view that also maintains single-cell resolution. We show that this implementation also allows for straight-forward tailoring of the point-spread-function, increases effective excitation power, and achievable image brightness. Moreover, rapid laser-focus control via an electrically tunable lens allows near-simultaneous imaging of remote regions separated in three dimensions and permits the bending of imaging planes to follow natural curvatures in biological structures. Crucially, our core design is readily implemented (and reversed) within a matter of hours, and compatible with a wide range of existing 2P customizations, making it highly suitable as a base platform for further development. We demonstrate the application of our system for imaging neuronal activity in a variety of examples in zebrafish, mice and fruit flies.

Turbulent three-dimensional dielectric electrohydrodynamic convection between two plates

2012 ◽  
Vol 696 ◽  
pp. 228-262 ◽  
Author(s):  
A. Kourmatzis ◽  
J. S. Shrimpton
Keyword(s):  
Spatial Data ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Energy Budgets ◽  
Turbulent Regime ◽  
Scalar Flux ◽  
Wide Range ◽  
Scalar Variance

AbstractThe fundamental mechanisms responsible for the creation of electrohydrodynamically driven roll structures in free electroconvection between two plates are analysed with reference to traditional Rayleigh–Bénard convection (RBC). Previously available knowledge limited to two dimensions is extended to three-dimensions, and a wide range of electric Reynolds numbers is analysed, extending into a fully inherently three-dimensional turbulent regime. Results reveal that structures appearing in three-dimensional electrohydrodynamics (EHD) are similar to those observed for RBC, and while two-dimensional EHD results bear some similarities with the three-dimensional results there are distinct differences. Analysis of two-point correlations and integral length scales show that full three-dimensional electroconvection is more chaotic than in two dimensions and this is also noted by qualitatively observing the roll structures that arise for both low (${\mathit{Re}}_{E} = 1$) and high electric Reynolds numbers (up to ${\mathit{Re}}_{E} = 120$). Furthermore, calculations of mean profiles and second-order moments along with energy budgets and spectra have examined the validity of neglecting the fluctuating electric field ${ E}_{i}^{\ensuremath{\prime} } $ in the Reynolds-averaged EHD equations and provide insight into the generation and transport mechanisms of turbulent EHD. Spectral and spatial data clearly indicate how fluctuating energy is transferred from electrical to hydrodynamic forms, on moving through the domain away from the charging electrode. It is shown that ${ E}_{i}^{\ensuremath{\prime} } $ is not negligible close to the walls and terms acting as sources and sinks in the turbulent kinetic energy, turbulent scalar flux and turbulent scalar variance equations are examined. Profiles of hydrodynamic terms in the budgets resemble those in the literature for RBC; however there are terms specific to EHD that are significant, indicating that the transfer of energy in EHD is also attributed to further electrodynamic terms and a strong coupling exists between the charge flux and variance, due to the ionic drift term.

scholarly journals Diagnostic Capabilities of a Smartphone- Based Low-Cost Microscope

2020 ◽  
Vol 6 (3) ◽  
pp. 522-525
Author(s):  
Dorina Hasselbeck ◽  
Max B. Schäfer ◽  
Kent W. Stewart ◽  
Peter P. Pott
Keyword(s):  
Low Cost ◽  
Field Of View ◽  
Parasitic Diseases ◽  
Optical Parameters ◽  
Trade Off ◽  
Resource Limited ◽  
Wide Range ◽  
Diagnostic Applications ◽  
Diagnostic Capabilities

AbstractMicroscopy enables fast and effective diagnostics. However, in resource-limited regions microscopy is not accessible to everyone. Smartphone-based low-cost microscopes could be a powerful tool for diagnostic and educational purposes. In this paper, the imaging quality of a smartphone-based microscope with four different optical parameters is presented and a systematic overview of the resulting diagnostic applications is given. With the chosen configuration, aiming for a reasonable trade-off, an average resolution of 1.23 μm and a field of view of 1.12 mm2 was achieved. This enables a wide range of diagnostic applications such as the diagnosis of Malaria and other parasitic diseases.

scholarly journals Two-photon polymerization nanolithography technology for fabrication of stimulus-responsive micro/nano-structures for biomedical applications

2020 ◽  
Vol 9 (1) ◽  
pp. 1118-1136
Author(s):  
Zhenjia Huang ◽  
Gary Chi-Pong Tsui ◽  
Yu Deng ◽  
Chak-Yin Tang
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Water Soluble ◽  
Fabrication Technology ◽  
Nano Fabrication ◽  
Two Photon ◽  
Nano Structures ◽  
Wide Range ◽  
Stimulus Responsive ◽  
Two Photon Polymerization

AbstractMicro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.

scholarly journals Design and implementation of a three dimensions (3D) printer for modeling and pre-manufacturing applications

2019 ◽  
Vol 9 (6) ◽  
pp. 4749
Author(s):  
Ghazi Qaryouti ◽  
Abdel Rahman Salbad ◽  
Sohaib A. Tamimi ◽  
Anwar Almofleh ◽  
Wael A. Salah ◽  
...  
Keyword(s):  
3D Printing ◽  
Manufacturing Sector ◽  
Low Cost ◽  
Three Dimensional ◽  
Three Dimensions ◽  
3D Printer ◽  
Overall Design ◽  
Design And Implementation ◽  
Manufacturing Applications ◽  
Functional Components

The three-dimensional (3D) printing technologies represent a revolution in the manufacturing sector due to their unique characteristics. These printers arecapable to increase the productivitywithlower complexity in addition tothe reduction inmaterial waste as well the overall design cost prior large scalemanufacturing.However, the applications of 3D printing technologies for the manufacture of functional components or devices remain an almost unexplored field due to their high complexity. In this paper the development of 3D printing technologies for the manufacture of functional parts and devices for different applications is presented. The use of 3D printing technologies in these applicationsis widelyused in modelingdevices usually involves expensive materials such as ceramics or compounds. The recent advances in the implementation of 3D printing with the use of environmental friendly materialsin addition to the advantages ofhighperformance and flexibility. The design and implementation of relatively low-cost and efficient 3D printer is presented. The developed prototype was successfully operated with satisfactory operated as shown from the printed samples shown.

μCHILL: a lightweight, modular system for handling crystalline samples at low temperatures under inert conditions

2018 ◽  
Vol 51 (2) ◽  
pp. 541-548 ◽  
Author(s):  
Michael Solar ◽  
Nils Trapp
Keyword(s):  
Low Temperatures ◽  
Room Temperature ◽  
Low Cost ◽  
Three Dimensional ◽  
Modular System ◽  
Preparation Time ◽  
Stable Conditions ◽  
Wide Range ◽  
Single Operator ◽  
Cold Gas

A procedure for preparing and mounting crystals under inert conditions is demonstrated, using a specialized apparatus (μCHILL) to provide a cold gas stream fed from a liquid nitrogen (LN2) reservoir or an open bath heat exchanger. A second, dry gas stream at room temperature enwraps the cold gas, protecting the sample preparation zone from ambient moisture. The technique is extremely flexible, requiring only a single operator, little practice and almost no preparation time. The device enables operation in a wide temperature range (at least 213 K to room temperature), providing temperature control and very stable conditions with no icing for extended time periods. The flexible, modular and low-cost design is based on three-dimensional-printed parts and readily available standard components, potentially making the device available to a wide range of users and applications not limited to single-crystal studies.

scholarly journals The magnetorotational instability prefers three dimensions

2020 ◽  
Vol 476 (2233) ◽  
pp. 20190622
Author(s):  
Jeffrey S. Oishi ◽  
Geoffrey M. Vasil ◽  
Morgan Baxter ◽  
Andrew Swan ◽  
Keaton J. Burns ◽  
...  
Keyword(s):  
Shear Rate ◽  
Angular Velocity ◽  
Laboratory Experiments ◽  
Three Dimensional ◽  
Linear Instability ◽  
Three Dimensions ◽  
Two Dimensional ◽  
Magnetorotational Instability ◽  
Dynamo Action ◽  
Wide Range

The magnetorotational instability (MRI) occurs when a weak magnetic field destabilizes a rotating, electrically conducting fluid with inwardly increasing angular velocity. The MRI is essential to astrophysical disc theory where the shear is typically Keplerian. Internal shear layers in stars may also be MRI-unstable, and they take a wide range of profiles, including near-critical. We show that the fastest growing modes of an ideal magnetofluid are three-dimensional provided the shear rate, S , is near the two-dimensional onset value, S c . For a Keplerian shear, three-dimensional modes are unstable above S  ≈ 0.10 S c , and dominate the two-dimensional modes until S  ≈ 2.05 S c . These three-dimensional modes dominate for shear profiles relevant to stars and at magnetic Prandtl numbers relevant to liquid-metal laboratory experiments. Significant numbers of rapidly growing three-dimensional modes remainy well past 2.05 S c . These finding are significant in three ways. First, weakly nonlinear theory suggests that the MRI saturates by pushing the shear rate to its critical value. This can happen for systems, such as stars and laboratory experiments, that can rearrange their angular velocity profiles. Second, the non-normal character and large transient growth of MRI modes should be important whenever three-dimensionality exists. Finally, three-dimensional growth suggests direct dynamo action driven from the linear instability.

scholarly journals A Printable Device for Measuring Clarity and Colour in Lake and Nearshore Waters

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 936 ◽  
Author(s):  
Robert Brewin ◽  
Thomas Brewin ◽  
Joseph Phillips ◽  
Sophie Rose ◽  
Anas Abdulaziz ◽  
...  
Keyword(s):  
3D Printing ◽  
Citizen Science ◽  
Scientific Discovery ◽  
Low Cost ◽  
Secchi Depth ◽  
Three Dimensional ◽  
Water Clarity ◽  
3D Printer ◽  
Satellite Validation ◽  
Wide Range

Two expanding areas of science and technology are citizen science and three-dimensional (3D) printing. Citizen science has a proven capability to generate reliable data and contribute to unexpected scientific discovery. It can put science into the hands of the citizens, increasing understanding, promoting environmental stewardship, and leading to the production of large databases for use in environmental monitoring. 3D printing has the potential to create cheap, bespoke scientific instruments that have formerly required dedicated facilities to assemble. It can put instrument manufacturing into the hands of any citizen who has access to a 3D printer. In this paper, we present a simple hand-held device designed to measure the Secchi depth and water colour (Forel Ule scale) of lake, estuarine and nearshore regions. The device is manufactured with marine resistant materials (mostly biodegradable) using a 3D printer and basic workshop tools. It is inexpensive to manufacture, lightweight, easy to use, and accessible to a wide range of users. It builds on a long tradition in optical limnology and oceanography, but is modified for ease of operation in smaller water bodies, and from small watercraft and platforms. We provide detailed instructions on how to build the device and highlight examples of its use for scientific education, citizen science, satellite validation of ocean colour data, and low-cost monitoring of water clarity, colour and temperature.

Wide Field-Of-View, Multi-Region Two-Photon Imaging of Neuronal Activity In Vivo

2016 ◽  
Author(s):  
Jeffrey N. Stirman ◽  
Ikuko T. Smith ◽  
Michael W. Kudenov ◽  
Spencer L. Smith
Keyword(s):  
Neuronal Activity ◽  
Field Of View ◽  
Wide Field ◽  
Two Photon ◽  
Wide Field Of View ◽  
Photon Imaging ◽  
Two Photon Imaging

scholarly journals Extended field-of-view ultrathin microendoscopes for high-resolution two-photon imaging with minimal invasiveness

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Andrea Antonini ◽  
Andrea Sattin ◽  
Monica Moroni ◽  
Serena Bovetti ◽  
Claudio Moretti ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Neuronal Activity ◽  
Signal To Noise Ratio ◽  
Brain Regions ◽  
Field Of View ◽  
Imaging Data ◽  
Minimal Invasiveness ◽  
Two Photon ◽  
State Dependent ◽  
Set Up

Imaging neuronal activity with high and homogeneous spatial resolution across the field-of-view (FOV) and limited invasiveness in deep brain regions is fundamental for the progress of neuroscience, yet is a major technical challenge. We achieved this goal by correcting optical aberrations in gradient index lens-based ultrathin (≤500 µm) microendoscopes using aspheric microlenses generated through 3D-microprinting. Corrected microendoscopes had extended FOV (eFOV) with homogeneous spatial resolution for two-photon fluorescence imaging and required no modification of the optical set-up. Synthetic calcium imaging data showed that, compared to uncorrected endoscopes, eFOV-microendoscopes led to improved signal-to-noise ratio and more precise evaluation of correlated neuronal activity. We experimentally validated these predictions in awake head-fixed mice. Moreover, using eFOV-microendoscopes we demonstrated cell-specific encoding of behavioral state-dependent information in distributed functional subnetworks in a primary somatosensory thalamic nucleus. eFOV-microendoscopes are, therefore, small-cross-section ready-to-use tools for deep two-photon functional imaging with unprecedentedly high and homogeneous spatial resolution.

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