In vivo intraoral waterflow quantification reveals hidden mechanisms of suction feeding in fish

Virtually all fish rely on flows of water to transport food to the back of their pharynx. While external flows that draw food into the mouth are well described, how intra-oral water flows manage to deposit food at the esophagus entrance remains unknown. In theory, the posteriorly moving water must, at some point, curve laterally and/or ventrally to exit through the gill slits. Such flows would eventually carry food away from the esophagus instead of towards it. This apparent paradox calls for a filtration mechanism to deviate food from the suction-feeding streamlines. To study this gap in our fundamental understanding of how fish feed, we developed and applied a new technique to quantify three-dimensional patterns of intra-oral water flows in vivo. We combined stereoscopic high-speed x-ray videos to quantify skeletal motion (XROMM) with 3D x-ray particle tracking (XPT) of approximately neutrally buoyant spheres of 1.4 mm in diameter. We showed, for carp (Cyprinus carpio) and tilapia (Oreochromis niloticus), that water tracers displayed higher curvatures than food tracers, indicating an inertia-driven filtration. In addition, tilapia also exhibited a 'central jet' flow pattern, which aids in quickly carrying food to the pharyngeal jaw region. When the food was trapped at the branchial basket, it was resuspended and carried more centrally by periodical bidirectional waterflows, synchronized with head-bone motions. By providing a complete picture of the suction-feeding process and revealing fundamental differences in food transport mechanisms among species, this new technique opens a new area of investigation to fully understand how most aquatic vertebrates feed.

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Future trends in the use of X-ray fluoroscopy for the measurement and modelling of joint motion

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411911422840 ◽

2011 ◽

Vol 225 (12) ◽

pp. 1136-1148 ◽

Cited By ~ 10

Author(s):

D C Ackland ◽

F Keynejad ◽

M G Pandy

Keyword(s):

High Speed ◽

Three Dimensional ◽

Joint Kinematics ◽

Joint Motion ◽

Computationally Efficient ◽

Surgical Interventions ◽

X Ray ◽

The Subject ◽

Skeletal Kinematics

Knowledge of three-dimensional skeletal kinematics during functional activities such as walking, is required for accurate modelling of joint motion and loading, and is important in identifying the effects of injury and disease. For example, accurate measurement of joint kinematics is essential in understanding the pathogenesis of osteoarthritis and its symptoms and for developing strategies to alleviate joint pain. Bi-plane X-ray fluoroscopy has the capacity to accurately and non-invasively measure human joint motion in vivo. Joint kinematics obtained using bi-plane X-ray fluoroscopy will aid in the development of more complex musculoskeletal models, which may be used to assess joint function and disease and plan surgical interventions and post-operative rehabilitation strategies. At present, however, commercial C-arm systems constrain the motion of the subject within the imaging field of view, thus precluding recording of motions such as overground gait. These fluoroscopy systems also operate at low frame rates and therefore cannot accurately capture high-speed joint motion during tasks such as running and throwing. In the future, bi-plane fluoroscopy systems may include computer-controlled tracking for the measurement of joint kinematics over entire cycles of overground gait without constraining motion of the subject. High-speed cameras will facilitate measurement of high-impulse joint motions, and computationally efficient pose-estimation software may provide a fast and fully automated process for quantification of natural joint motion.

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High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

Nature Communications ◽

10.1038/s41467-020-19851-1 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Jiang Lan Fan ◽

Jose A. Rivera ◽

Wei Sun ◽

John Peterson ◽

Henry Haeberle ◽

...

Keyword(s):

Blood Flow ◽

High Speed ◽

Laser Scanning ◽

Three Dimensional ◽

Laser Scanning Microscopy ◽

Fluorescence Signal ◽

Imaging Method ◽

Spatiotemporal Resolution ◽

Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

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High-Speed X-Ray Imaging of Diesel Injector Needle Motion

ASME 2009 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2009-76032 ◽

2009 ◽

Cited By ~ 19

Author(s):

A. L. Kastengren ◽

C. F. Powell ◽

Z. Liu ◽

K. Fezzaa ◽

J. Wang

Keyword(s):

High Speed ◽

Three Dimensional ◽

Linear Increase ◽

Nozzle Geometry ◽

X Ray ◽

Needle Position ◽

X Ray Imaging ◽

Linear Oscillation ◽

Degree Of Convergence

Phase-enhanced x-ray imaging has been used to examine the geometry and dynamics of four diesel injector nozzles. The technique uses a high-speed camera, which allows the dynamics of individual injection events to be observed in real time and compared. Moreover, data has been obtained for the nozzles from two different viewing angles, allowing for the full three-dimensional motions of the needle to be examined. This technique allows the needle motion to be determined in situ at the needle seat and requires no modifications to the injector hardware, unlike conventional techniques. Measurements of the nozzle geometry have allowed the average nozzle diameter, degree of convergence or divergence, and the degree of rounding at the nozzle inlet to be examined. Measurements of the needle lift have shown that the lift behavior of all four nozzles consists of a linear increase in needle lift with respect to time until the needle reaches full lift and a linear decrease as the needle closes. For all four nozzles, the needle position oscillates at full lift with a period of 170–180 μs. The full-lift position of the needle changes as the rail pressure increases, perhaps reflecting compression of the injector components. Significant lateral motions were seen in the two single-hole nozzles, with the needle motion perpendicular to the injector axis resembling a circular motion for one nozzle and linear oscillation for the other nozzle. The two VCO multihole nozzles show much less lateral motion, with no strong oscillations visible.

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Three-Dimensional Characterization of the Microstructure of Bioglass/Polyethylene Composite by X-Ray Microtomography

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.330-332.503 ◽

2007 ◽

Vol 330-332 ◽

pp. 503-506

Author(s):

Xiao Wei Fu ◽

Jie Huang ◽

E.S. Thian ◽

Serena Best ◽

William Bonfield

Keyword(s):

Spatial Distribution ◽

Volume Fraction ◽

Three Dimensional ◽

X Ray ◽

Polyethylene Composite ◽

Bioactive Properties ◽

Recent Developments ◽

3D Information

A Bioglass® reinforced polyethylene (Bioglass®/polyethylene) composite has been prepared, which combines the high bioactivity of Bioglass® and the toughness of polyethylene. The spatial distribution of Bioglass® particles within the composite is important for the performance of composites in-vivo. Recent developments in X-ray microtomography (XμT) have made it possible to visualize internal and microstructural details with different X-ray absorbencies, nondestructively, and to acquire 3D information at high spatial resolution. In this study, the volume fraction and 3D spatial distribution of Bioglass® particles has been acquired quantitatively by XμT. The information obtained provides a foundation for understanding the mechanical and bioactive properties of the Bioglass®/polyethylene composites.

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Direct characterization of solute transport in unsaturated porous media using fast X-ray synchrotron microtomography

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2011716117 ◽

2020 ◽

Vol 117 (38) ◽

pp. 23443-23449 ◽

Cited By ~ 3

Author(s):

Sharul Hasan ◽

Vahid Niasar ◽

Nikolaos K. Karadimitriou ◽

Jose R. A. Godinho ◽

Nghia T. Vo ◽

...

Keyword(s):

Solute Transport ◽

High Speed ◽

Three Dimensional ◽

Concentration Field ◽

Solute Concentration ◽

Breakthrough Curves ◽

Pore Scale ◽

X Ray ◽

Long Tails ◽

Computed Microtomography

Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 μm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (>50 TB) was produced, while imaging the evolution of the solute concentration with time at any given point within the field of view. We show that the fluids’ topology has a critical signature on the non-Fickian transport, which yet needs to be included in the Darcy-scale solute transport models. The three-dimensional (3D) results show that the fully mixing assumption at the pore scale is not valid, and even after injection of several pore volumes the concentration field at the pore scale is not uniform. Additionally, results demonstrate that dispersivity is changing with saturation, being twofold larger at the saturation of 0.52 compared to that at the fully saturated domain.

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In vivo noninvasive three‐dimensional (3D) assessment of microwave thermal ablation zone using non‐contrast‐enhanced x‐ray CT

Medical Physics ◽

10.1002/mp.14428 ◽

2020 ◽

Vol 47 (10) ◽

pp. 4721-4734

Author(s):

Omri Ziv ◽

S. Nahum Goldberg ◽

Yitzhak Nissenbaum ◽

Jacob Sosna ◽

Noam Weiss ◽

...

Keyword(s):

Thermal Ablation ◽

Three Dimensional ◽

Ablation Zone ◽

X Ray ◽

Contrast Enhanced

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Ultrasonic Guidance of Prosthetic Hip Joint Effusion Aspiration

Journal of Diagnostic Medical Sonography ◽

10.1177/875647938500100602 ◽

1985 ◽

Vol 1 (6) ◽

pp. 247-249

Author(s):

Dennis E. Paul

Keyword(s):

Ultrasound Imaging ◽

Hip Joint ◽

Fluid Collection ◽

Three Dimensional ◽

New Technique ◽

Joint Effusion ◽

X Ray ◽

Orthopedic Patient ◽

A New Technique

Until recently ultrasound imaging of the orthopedic patient has been limited. A new technique is presented here for the use of ultrasound imaging in guiding prosthetic hip joint effusion aspirations. Previously, x-ray fluoroscopy was used for these procedures. The use of ultrasound allows the examiner to directly visualize the abnormal fluid collection without using contrast injections, provides a three-dimensional orientation of the anatomy, and eliminates the x-ray exposure to the patient and the staff.

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