scholarly journals Development of a Microfluidic Device to Form a Long Chemical Gradient in a Tissue from Both Ends with an Analysis of Its Appearance and Content

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1482
Author(s):  
Yasunori Tokuoka ◽  
Keiichi Kondo ◽  
Noboru Nakaigawa ◽  
Tadashi Ishida
Keyword(s):  
Concentration Gradient ◽  
Three Dimensional ◽  
Perfusion Culture ◽  
Longitudinal Direction ◽  
Tissue Specimen ◽  
Chemical Gradient ◽  
Metabolic Functions ◽  
Active Chemical ◽  
Gradient Formation ◽  
Blue Intensity

Tissue assays have improved our understanding of cancers in terms of the three-dimensional structures and cellular diversity of the tissue, although they are not yet well-developed. Perfusion culture and active chemical gradient formation in centimeter order are difficult in tissue assays, but they are important for simulating the metabolic functions of tissues. Using microfluidic technology, we developed an H-shaped channel device that could form a long concentration gradient of molecules in a tissue that we could then analyze based on its appearance and content. For demonstration, a cylindrical pork tissue specimen was punched and equipped in the H-shaped channel device, and both ends of the tissue were exposed to flowing distilled and blue-dyed water for 100 h. After perfusion, the tissue was removed from the H-shaped channel device and sectioned. The gradient of the blue intensity along the longitudinal direction of the tissue was measured based on its appearance and content. We confirmed that the measured gradients from the appearance and content were comparable.

scholarly journals Effect of Needling Parameters and Manufacturing Porosities on the Effective Thermal Conductivity of a 3D Carbon–Carbon Composite

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3750 ◽  
Author(s):  
Abdulrahman Alghamdi ◽  
Hamzah Alharthi ◽  
Ali Alamoudi ◽  
Abdullah Alharthi ◽  
Ammar Kensara ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Finite Element Modelling ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Carbon Composite ◽  
Element Modelling ◽  
X Ray ◽  
Needle Punching ◽  
Multiscale Finite Element ◽  
3D Composite

Needle-punching is used as an alternative to expensive and sophisticated three-dimensional (3D) weaving processes to prepare a 3D composite. In this study, a 3D needled carbon–carbon (C/C) composite structure was examined using X-ray tomography and scanning electron microscopy (SEM). The effects of manufacturing porosities, needling diameter and needling density on the thermal conductivity of the composite were determined through multiscale finite-element modelling. The degradation of thermal conductivity caused by the manufacturing porosity was higher in the longitudinal direction than in the through-thickness direction. Moreover, it was found that the through-thickness thermal conductivity of the composites increased with increasing needling diameter and density.

Simple method for preparing a concentration gradient of serum components by freezing and thawing

1991 ◽  
Vol 37 (7) ◽  
pp. 1225-1229 ◽  
Author(s):  
Tetsuo Hirano ◽  
Toshiaki Yoneyama ◽  
Hiroko Matsuzaki ◽  
Takainitsu Sekine
Keyword(s):  
Concentration Gradient ◽  
Clinical Laboratory ◽  
Freezing Temperature ◽  
Test Results ◽  
Freezing And Thawing ◽  
Serum Samples ◽  
Simple Method ◽  
Gradient Formation ◽  
Repeated Freezing ◽  
Serum Components

Abstract We created a simple method for obtaining a series of successively more-concentrated samples from a serum without changing the ratio of its components. We froze a pooled serum and then allowed it to thaw undisturbed. The serum components formed a gradient of increasing concentration from the top of the sample to the bottom. We found that (a) in test results, each fraction of serum in the gradient showed almost the same relative concentrations of components (i.e., inorganic and organic compounds, proteins, metals, and hormones), irrespective of atomic or molecular mass; (b) the concentration gradient depended on the thawing temperature but not on the freezing temperature; (c) when we thawed the frozen sample with centrifugation, the slope of the concentration gradient increased with increasing centrifugal force; (d) when the thawed sample was fractionated into 10 fractions from the top to the bottom, the original serum concentration was always maintained between the sixth and seventh fractions from the top; and (e) the concentration gradient became steeper with repeated freezing and thawing. By using this method, one can easily prepare serum samples at gradients of concentration useful in the clinical laboratory, although the mechanism of gradient formation is still unclear.

scholarly journals Effective 1D Time-Dependent Schrödinger Equations for 3D Geometrically Correlated Systems

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3033
Author(s):  
Devashish Pandey ◽  
Xavier Oriols ◽  
Guillermo Albareda
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Time Dependent ◽  
Ab Initio Molecular Dynamics ◽  
Quantitative Accuracy ◽  
Dimensional Simulation ◽  
Transport Problems ◽  
Computational Resources

The so-called Born–Huang ansatz is a fundamental tool in the context of ab-initio molecular dynamics, viz., it allows effectively separating fast and slow degrees of freedom and thus treating electrons and nuclei with different mathematical footings. Here, we consider the use of a Born–Huang-like expansion of the three-dimensional time-dependent Schrödinger equation to separate transport and confinement degrees of freedom in electron transport problems that involve geometrical constrictions. The resulting scheme consists of an eigenstate problem for the confinement degrees of freedom (in the transverse direction) whose solution constitutes the input for the propagation of a set of coupled one-dimensional equations of motion for the transport degree of freedom (in the longitudinal direction). This technique achieves quantitative accuracy using an order less computational resources than the full dimensional simulation for a typical two-dimensional geometrical constriction and upto three orders for three-dimensional constriction.

Mean and turbulence characteristics of three-dimensional wall jets

1975 ◽  
Vol 71 (3) ◽  
pp. 541-562 ◽  
Author(s):  
N. V. Chandrasekhara Swamy ◽  
P. Bandyopadhyay
Keyword(s):  
Skin Friction ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Experimental Investigations ◽  
Length Scale ◽  
Wall Jet ◽  
Similar Form ◽  
Turbulence Characteristics ◽  
Self Similar ◽  
Turbulent Wall

This paper reports experimental investigations on the characteristic decay and the radial-type decay regions of a three-dimensional isothermal turbulent wall jet in quiescent surroundings. The velocity and the length scale behaviour for both the longitudinal and the transverse directions are studied, and compared with the results of other workers. The estimated skin friction is discussed in relation to the available data from earlier investigations. Wall jet expansion rates and the behaviour of skin friction are also discussed. The rate of approach of turbulence components to a self-similar form is found to be influenced by the fact that the expansion rate of the wall jet in the longitudinal direction is different from that in the transverse.

scholarly journals Morphogen Gradient Formation Unraveled Using In Vivo Three-dimensional Single Molecule Microscopy

2009 ◽  
Vol 96 (3) ◽  
pp. 33a ◽  
Author(s):  
Laurent Holtzer ◽  
Anna Kicheva ◽  
Marcos Gonzalez-Gaitan ◽  
Thomas Schmidt
Keyword(s):  
Single Molecule ◽  
Three Dimensional ◽  
Morphogen Gradient ◽  
Single Molecule Microscopy ◽  
Gradient Formation

Boundary layer over spinning blunt body of revolution at incidence including Magnus forces

1978 ◽  
Vol 363 (1714) ◽  
pp. 357-380 ◽  
Keyword(s):  
Boundary Layer ◽  
Skin Friction ◽  
Blunt Body ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Meridional Flow ◽  
Meridional Plane ◽  
Magnus Force ◽  
Displacement Thickness

An incompressible laminar flow over a spinning blunt-body at incidence is investigated. The approach follows strictly the three-dimensional boundary layer theory, and the lack of initial profiles is readily resolved. The rule of the dependence zone is satisfied with the Krause scheme, and complete numerical solutions are obtained for an ellipsoid of revolution at 6° incidence and two spin rates. Spinning causes asymmetry which, in turn, introduces the Magnus force. The asymmetry is most pronounced in crossflow, but is also noticeable in the skin friction and displacement thickness of the meridional flow. A variety of crossflow profiles are determined as are the streamline patterns in the cross- and meridional-plane which are especially useful in visualizing the flow structure. Detailed distribution of skin friction, displacement thickness, and centrifugal pressure are presented. A negative crossflow displacement thickness is found to be physically meaningful. The Magnus forces due to the crossflow skin friction and the centrifugal pressure are determined; these two forces partly compensate for each other. At lower spin rate, the frictional force is larger, resulting in a positive Magnus force. At high spin rate, the opposite is obtained. At high incidence (30°) the present boundary layer calculations could be carried out in the longitudinal direction, only up to the beginning of an open separation.

Three-dimensional dissipative optical solitons

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Dumitru Mihalache
Keyword(s):  
Landau Equation ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Optical Solitons ◽  
Ginzburg Landau ◽  
Systematic Analysis ◽  
Dissipative Solitons ◽  
Existence Domain ◽  
Existence And Stability ◽  
The Stability

AbstractA brief overview of recent theoretical results in the area of three-dimensional dissipative optical solitons is given. A systematic analysis demonstrates the existence and stability of both fundamental (spinless) and spinning three-dimensional dissipative solitons in both normal and anomalous group-velocity regimes. Direct numerical simulations of the evolution of stationary solitons of the three-dimensional cubic-quintic Ginzburg-Landau equation show full agreement with the predictions based on computation of the instability eigenvalues from the linearized equations for small perturbations. It is shown that the diffusivity in the transverse plane is necessary for the stability of vortex solitons against azimuthal perturbations, while fundamental (zero-vorticity) solitons may be stable in the absence of diffusivity. It has also been found that, at values of the nonlinear gain above the upper border of the soliton existence domain, the three-dimensional dissipative solitons either develop intrinsic pulsations or start to expand in the temporal (longitudinal) direction keeping their structure in the transverse spatial plane.

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