scholarly journals Development of three-dimensional physiological function imaging of biological body by transillumination imaging using near infrared light - preliminary research -

10.29007/dvzs ◽  
2020 ◽  
Author(s):  
Ngoc An Dang Nguyen ◽  
Phuong Anh Bui ◽  
Anh Tu Tran ◽  
Trung An Dang Nguyen ◽  
Van Chinh Nguyen ◽  
...  

In biological tissue, there are different kinds of endogenous chromophores. Their absorption spectra in the optical range are sensitive to the physiological change of the animal body. In the near-infrared region (700-1200 nm wavelength), hemoglobin has a characteristic absorption spectrum which is dependent on its redox state. Therefore, the functional information inside the animal body could be obtained noninvasively by measuring the transmitted light. By detecting the change of the absorption characteristics of the animal body, the functional change inside the body can be detected in a two-dimensional transillumination image. In this paper, we propose preliminary research on developing a novel imaging modality of biological body parts. Using the two-dimensional images obtained in many different orientations, three-dimensional physiological function imaging of the biological body by transillumination could be expected. This paper presents a preliminary result in the experiment to show the feasibility of this technique.

2019 ◽  
Vol 20 (6) ◽  
pp. 1424 ◽  
Author(s):  
Kyujin Shin ◽  
Yo Song ◽  
Yeongchang Goh ◽  
Kang Lee

Lanthanide-doped upconversion nanoparticles (UCNPs) are inorganic nanomaterials in which the lanthanide cations embedded in the host matrix can convert incident near-infrared light to visible or ultraviolet light. These particles are often used for long-term and real-time imaging because they are extremely stable even when subjected to continuous irradiation for a long time. It is now possible to image their movement at the single particle level with a scale of a few nanometers and track their trajectories as a function of time with a scale of a few microseconds. Such UCNP-based single-particle tracking (SPT) technology provides information about the intracellular structures and dynamics in living cells. Thus far, most imaging techniques have been built on fluorescence microscopic techniques (epifluorescence, total internal reflection, etc.). However, two-dimensional (2D) images obtained using these techniques are limited in only being able to visualize those on the focal planes of the objective lens. On the contrary, if three-dimensional (3D) structures and dynamics are known, deeper insights into the biology of the thick cells and tissues can be obtained. In this review, we introduce the status of the fluorescence imaging techniques, discuss the mathematical description of SPT, and outline the past few studies using UCNPs as imaging probes or biologically functionalized carriers.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yiyue Zhang ◽  
Masoumeh Keshavarz ◽  
Elke Debroye ◽  
Eduard Fron ◽  
Miriam Candelaria Rodríguez González ◽  
...  

Abstract Lead halide perovskites have attracted tremendous attention in photovoltaics due to their impressive optoelectronic properties. However, the poor stability of perovskite-based devices remains a bottleneck for further commercial development. Two-dimensional perovskites have great potential in optoelectronic devices, as they are much more stable than their three-dimensional counterparts and rapidly catching up in performance. Herein, we demonstrate high-quality two-dimensional novel perovskite thin films with alternating cations in the interlayer space. This innovative perovskite provides highly stable semiconductor thin films for efficient near-infrared light-emitting diodes (LEDs). Highly efficient LEDs with tunable emission wavelengths from 680 to 770 nm along with excellent operational stability are demonstrated by varying the thickness of the interlayer spacer cation. Furthermore, the best-performing device exhibits an external quantum efficiency of 3.4% at a high current density (J) of 249 mA/cm2 and remains above 2.5% for a J up to 720 mA cm−2, leading to a high radiance of 77.5 W/Sr m2 when driven at 6 V. The same device also shows impressive operational stability, retaining almost 80% of its initial performance after operating at 20 mA/cm2 for 350 min. This work provides fundamental evidence that this novel alternating interlayer cation 2D perovskite can be a promising and stable photonic emitter.


Author(s):  
Juan Luis Alcázar

Abstract Two-dimensional ultrasound is commonly used for assessing uterine pathology. Three-dimensional ultrasound is a new imaging modality, which is being introduced into clinical practice. The aim of this paper is addressing the current status of three-dimensional ultrasound in the assessment of uterine pathology.


Author(s):  
Bruno S. Carmo ◽  
Rafael S. Gioria ◽  
Ivan Korkischko ◽  
Cesar M. Freire ◽  
Julio R. Meneghini

Two- and three-dimensional simulations of the flow around straked cylinders are presented. For the two-dimensional simulations we used the Spectral/hp Element Method, and carried out simulations for five different angles of rotation of the cylinder with respect to the free stream. Fixed and elastically-mounted cylinders were tested, and the Reynolds number was kept constant and equal to 150. The results were compared to those obtained from the simulation of the flow around a bare cylinder under the same conditions. We observed that the two-dimensional strakes are not effective in suppressing the vibration of the cylinders, but also noticed that the responses were completely different even with a slight change in the angle of rotation of the body. The three-dimensional results showed that there are two mechanisms of suppression: the main one is the decrease in the vortex shedding correlation along the span, whilst a secondary one is the vortex wake formation farther downstream.


2007 ◽  
Vol 51 (02) ◽  
pp. 182-186
Author(s):  
Tracie J. Barber

The accurate prediction of ground effect aerodynamics is an important aspect of wing-in-ground (WIG) effect vehicle design. When WIG vehicles operate over water, the deformation of the nonrigid surface beneath the body may affect the aerodynamic performance of the craft. The likely surface deformation has been considered from a theoretical and numerical position. Both two-dimensional and three-dimensional cases have been considered, and results show that any deformation occurring on the water surface is likely to be caused by the wing tip vortices rather than an increased pressure distribution beneath the wing.


Geophysics ◽  
1975 ◽  
Vol 40 (2) ◽  
pp. 309-324 ◽  
Author(s):  
Gerald W. Hohmann

The induced polarization (IP) and electromagnetic (EM) responses of a three‐dimensional body in the earth can be calculated using an integral equation solution. The problem is formulated by replacing the body by a volume of polarization or scattering current. The integral equation is reduced to a matrix equation, which is solved numerically for the electric field in the body. Then the electric and magnetic fields outside the inhomogeneity can be found by integrating the appropriate dyadic Green’s functions over the scattering current. Because half‐space Green’s functions are used, it is only necessary to solve for scattering currents in the body—not throughout the earth. Numerical results for a number of practical cases show, for example, that for moderate conductivity contrasts the dipole‐dipole IP response of a body five units in strike length approximates that of a two‐dimensional body. Moving an IP line off the center of a body produces an effect similar to that of increasing the depth. IP response varies significantly with conductivity contrast; the peak response occurs at higher contrasts for two‐dimensional bodies than for bodies of limited length. Very conductive bodies can produce negative IP response due to EM induction. An electrically polarizable body produces a small magnetic field, so that it is possible to measure IP with a sensitive magnetometer. Calculations show that horizontal loop EM response is enhanced when the background resistivity in the earth is reduced, thus confirming scale model results.


2009 ◽  
Vol 3 (2) ◽  
Author(s):  
A. Mohamed ◽  
A. Erdman ◽  
G. Timm

Previous biomechanical models of the penis that have attempted to simulate penile erections have either been limited to two-dimensional geometry, simplified three-dimensional geometry or made inaccurate assumptions altogether. Most models designed the shaft of the penis as a one-compartment pressurized vessel fixed at one end, when in reality it is a two-compartments pressurized vessel, in which the compartments diverge as they enter the body and are fixed at two separate points. This study began by designing simplified two-dimensional and three-dimensional models of the erect penis using Finite Element Analysis (FEA) methods with varying anatomical considerations for analyzing structural stresses, axial buckling and lateral deformation. The study then validated the results by building physical models replicating the computer models. Finally a more complex and anatomically accurate model of the penis was designed and analyzed. There was a significant difference in the peak von-Mises stress distribution between the one-compartment pressurized vessel and the more anatomically correct two-compartments pressurized vessel. Furthermore, the two-compartments diverging pressurized vessel was found to have more structural integrity when subject to external lateral forces than the one-compartment pressurized vessel. This study suggests that Mother Nature has favored an anatomy of two corporal cavernosal bodies separated by a perforated septum as opposed to one corporal body, due to better structural integrity of the tunica albuginea when subject to external forces.


2017 ◽  
Vol 477 ◽  
pp. 230-234 ◽  
Author(s):  
Nobuhiko Ozaki ◽  
Shingo Kanehira ◽  
Yuma Hayashi ◽  
Shunsuke Ohkouchi ◽  
Naoki Ikeda ◽  
...  

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