CN102033173A - Method for studying dielectric property of cell by using ultrasonic pulse dynammic electricity - Google Patents

Abstract

The invention discloses a method for studying the dielectric property of the cell by using ultrasonic pulse dynammic electricity, comprising the following steps: establishing a cell unit model, preparing a cell suspension, detecting CVI (cell vibration current), calculating the CVI and analyzing the dielectric property of the cell according to the CVI detection result. When the CVI is detected, the ultrasonic pulse with the angular frequency omega is made to act on both the cell suspension and normal saline, and the total current TVI in the cell suspension and the ion vibration current in the normal saline are detected. The method for studying the dielectric property of the cell by using ultrasonic pulse dynammic electricity can be used to study the dielectric property of the cell by making ultrasonic pulse act on the cell and accurately detecting the change of charges on the surface of the cell so as to achieve the purpose of studying the ultrasonic biological effect of the cell. The device applied to the method for studying the dielectric property of the cell by using ultrasonic pulse dynammic electricity has simple structure, and the method for studying the dielectric property of the cell by using ultrasonic pulse dynammic electricity has good reproducibility and can not cause any damage to the cell.

Description

A kind of method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic

Technical field

The invention belongs to biological cell fundamental research field, it is a kind of method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic, this method is moved electric theory model from electric charge level research cell dielectric characteristic as sonic probe according to suspension cell with ultrasonic pulse, can be used for the research of cell membrane surface charging characteristic aspect, especially cell biological effect of ultrasound aspect is studied in ultrasonication down in real time and had unique advantages.

Background technology

The ultrasound wave irradiation of doses can cause multiple biological effect in the biosystem of varying level.Up to the present, under many kinds of situations, the physical mechanism of biological effect of ultrasound is still very unclear, does not more have a kind of suitable method can study the process of biological effect of ultrasound in real time.At present, mainly contain methods such as cell electrophoresis method, electrochemical impedance method, patch clamp technique at cell dielectric The Characteristic Study method.The cell electrophoresis method is under the extra electric field effect, cell is done distinctive moving according to the difference of its surface charge, size, shape, detect the method for cell membrane electrical characteristics according to the information of the electronic characteristic aspects such as electrophoretic mobility of cell, mainly there are shortcomings such as more numerous, required long period of operation, repeatability and sensitivity is relatively poor in it.The electrochemical impedance method is that a kind of electricity with little amplitude is pulsed as the electrochemical impedance measuring method of disturbing signal; In addition, it also can study electrode system with the very wide impedance spectrum of measurement range, thereby obtains cell electrodynamics information, and studies the method for cell membrane charge characteristic with this, and there are shortcomings such as complicated operation, repeatability and low precision equally in this method.Patch clamp technique is to obtain the technology of electronics aspect information from small pieces (a few approximately square micron) film, promptly keep transmembrane voltage constant-voltage clamp, thereby measure technology by cell membrane gas current size, though this method precision is very high, apparatus expensive, complicated operation.In addition, all methods all can not be studied the biological effect of ultrasound of cell in real time more than under ultrasonication.

When the ultrasound wave (alternating pressure field) of a high frequency by a colloid system, the density of medium around wherein the density of colloidal particle is different from, the inertial force that the vibration of suspension causes causes charged particle to follow its motion, thereby causes the electrostatic double layer on micelle surface to produce distortion.Fixed bed and diffusion layer relatively move in the micelle surface electric double layer, and the change of the zeta potential that shows can be detected by outer electrode, and the current potential of this variation is called colloid vibration current potential (CVP); Simultaneously, if the external circuit closure owing to ultrasonic passing through, will produce the electric current of an alternation in the system, the electric current of this alternation is called as colloid oscillating current (CVI).Same electroacoustic phenomenon also can appear in the electrolyte solution.Because negative ion is different mutually with cationic group in the solution, therefore they will produce periodically dislocation under ultrasonic effect, thereby oscillating current occurs.This electric current is called as ion oscillating current (IVI).Though to first time of this electroacoustic phenomenon report is to propose prediction in 1933 by the debye, up to the nineties in last century Mike O'Brien just set forth his theory, thereby make this electroacoustic techniques that tremendous development arranged and be used in the business equipment.The moving topmost advantage of electrical measurement method is the original strong solution that need not dilute of its energy measurement, even the energy measurement plot ratio reaches 50% solution, and this point makes its be fit to very much many dense biosystems.And in this measuring system, the magnitude range of micelle can be from 100nm to 10 μ m, and this makes it very be fit to size probably is the human red cells of 6 μ m to 9 μ m.The most promising purposes of this technology is exactly medical early diagnosis and the research of cell biological effect of ultrasound in real time, and can be further used for the research of the aspects such as ultrasonic imaging of unicellular characteristic research.

Up to the present, the research of the moving electric theory method of colloid and application are mainly at chemical field, basically all be measurement to colloidal suspension particle zeta potential, these particles mainly all are ganoid polymkeric substance grits, the soft particle that ion can penetrating high molecular polymer yet cell but is a surface coverage.In addition, in the moving electric theory model of colloid in the past, all be to use continuous ultrasound wave as vibration source, be not suitable for biological cell is studied, because be approximately 10mw/cm at the sound intensity ²The time, under the ultrasound wave effect, cell has begun to produce biological effect of ultrasound, causes testing result inaccurate; And the low sound intensity acts in the cell suspension, is unlikely to make a little less than distortion of cell electrostatic double layer or the distortion very, makes to detect to become difficult unusually.So use ultrasonic pulse among the present invention, single detection ultrasonic pulse energy suitably can be increased, thereby detection signal is increased as sonic probe; But the equal sound intensity of whole ultrasonic popin is reduced, so that it can the pair cell physiological property not exert an influence.In addition, further also can detect pulse, thereby reach the function of real-time research cell biological effect of ultrasound by among the functional continuous ultrasound ripple of irradiation, inserting.

At present, just proposed both at home and abroad the model that ion can penetrating flexible glue grain in theory, but do not proposed correlation theory model and its implementation that actual cell suspension moves electric theory.

Summary of the invention

The objective of the invention is to overcome existing cell dielectric characteristic research method can not be studied the cell biological effect of ultrasound in real time under ultrasonication deficiency, a kind of method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic is provided, this method is according to the moving electric theory model of cell suspension, by the ultrasonic functional status of continuous adjustment, thereby realize real-time ultrasound Biological effects under the ultrasonication.This method realizes that not only equipment is simple, processing ease, and pair cell is without any damage.

The objective of the invention is to solve by the following technical programs:

This method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic may further comprise the steps:

1) sets up the cell model of element

Suppose that diameter is a, and the cell that the surface is uniform-distribution with negative charge is that the ion of d can be wrapped in by penetrating polymer dielectric electrostatic double layer by thickness, this integral body is called a cell unit, and it is a that this cell unit is described to an internal diameter, and external diameter is the spherical flexible glue grain of b=a+d; Suppose that the cell model of element is that quantivalency is the fixed charge aggregate of Z, its skin is uniform-distribution with the electrostatic double layer that density is N;

2) configuration cell suspension

Cell suspension is by after the fresh plasma process centrifugal treating, is hybridly prepared into the suspension that test cell line needs concentration with physiological saline;

3) detect cell oscillating current CVI

Making angular frequency is that the ultrasonic pulse of ω acts on respectively on cell suspension and the physiological saline, detects electric current summation TVI in the cell suspension and the ion oscillating current IVI in the physiological saline; Calculate cell oscillating current CVI according to following formula:

TVI＝IVI+CVI； (1)

4) analysis of cells dielectric property

According to the moving electric theory of colloid, calculate the dynamic electrophoretic mobility μ (ω) of cell, again according to the relation between dynamic electrophoretic mobility μ (ω) and the cell electrostatic double layer current potential, obtain the Donnan current potential Ψ of cell electrostatic double layer _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _OThereby, realize the research of pair cell dielectric property.

In step 4) of the present invention, calculate the dynamic electrophoretic mobility μ (ω) of cell according to following formula:

$\mathrm{IVI}=\frac{\mathrm{zen}}{{\mathrm{\ρ}}_0}(\frac{m_{+}-{\mathrm{\ρ}}_0{V}_{+}}{{\mathrm{\λ}}_{+}}-\frac{m_{-}-{\mathrm{\ρ}}_0{V}_{-}}{{\mathrm{\λ}}_{-}})\mathrm{\ΔP}---\left(2\right)$

In the formula (2), z is the quantivalency of element in the electrolytic solution, and e is the unit charge electric weight, and n is an electrolyte concentration in the physiological saline, ρ ₀Be the concentration of physiological saline, m ₊, V ₊Be respectively cationic quality and quantivalency in the physiological saline, m _-, V _-Be respectively anionic quality and quantivalency in the physiological saline, Δ P is the conductivity of physiological saline; In the formula (3),

Be the volume fraction of cell individual,

Be the volume fraction of cell electrostatic double layer, ρ _CAnd ρ _SBe respectively the mass density of cell and electrostatic double layer;

The drag coefficient λ of negative ions in the formula (2) ₊And λ _-Respectively with corresponding negative ions limit conductance With

Relevant, calculate according to following formula:

${\mathrm{\λ}}_{\±}=\frac{N_A{e}^{2}z}{{\mathrm{\Λ}}_{\±}^0}---\left(4\right)$

N in the formula (4) _ABe avogadros constant, obtain the dynamic electrophoretic mobility μ (ω) of cell according to above formula.

In addition, in step 4) of the present invention, calculate the Donnan current potential Ψ of cell electrostatic double layer according to following formula _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _O:

$\mathrm{\μ}\left(\mathrm{\ω}\right)=\frac{2{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0}{3\mathrm{\η}}\left[\frac{1-\mathrm{i\γb}}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right](1+\frac{a^3}{2b^3})$

$\×\left[\frac{{\mathrm{\Ψ}}_0/{\mathrm{\κ}}_m+{\mathrm{\Ψ}}_{\mathrm{DON}}/\mathrm{\β}}{1/{\mathrm{\κ}}_m+1/\mathrm{\β}}\right]$

$+\left[\frac{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)(1-a^3/b^3)}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right]\frac{\mathrm{ZeN}}{\mathrm{\η}{\mathrm{\β}}^2}---\left(5\right)$

Wherein:

${\mathrm{\Ψ}}_{\mathrm{DON}}=\frac{\mathrm{kT}}{\mathrm{ze}}\ln [\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]---\left(6\right)$

${\mathrm{\Ψ}}_0=\frac{\mathrm{kT}}{\mathrm{ze}}\left(\ln \right[\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]$

$+\frac{2\mathrm{zn}}{\mathrm{ZN}}[1-{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}])---\left(7\right)$

${\mathrm{\κ}}_m=\mathrm{\κ}{[1+{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2]}^{1/4}---\left(8\right)$

$\mathrm{\κ}={\left(\frac{2z^2{e}^{2}n}{{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0\mathrm{kT}}\right)}^{1/2}---\left(9\right)$

$\mathrm{\λ}={\left(\frac{\mathrm{\υ}}{\mathrm{\η}}\right)}^{1/2}---\left(10\right)$

$\mathrm{\γ}=(1+i)\sqrt{\frac{\mathrm{\ω}{\mathrm{\ρ}}_0}{2\mathrm{\η}}}---\left(11\right)$

$\mathrm{\β}=\mathrm{\λ}\sqrt{1-{\left(\frac{\mathrm{\γ}}{\mathrm{\λ}}\right)}^2}---\left(12\right)$

$\mathrm{\Γ}=\frac{{\mathrm{\γ}}^2[V_c({\mathrm{\ρ}}_c-{\mathrm{\ρ}}_0)+V_s({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_0)]}{6\mathrm{\πb}{\mathrm{\ρ}}_0}---\left(13\right)$

$f_c={\left(\frac{a}{b}\right)}^3---\left(14\right)$

$f_s=\frac{V_s}{4\mathrm{\π}{b}^3/3}---\left(15\right)$

More than ε in each formula _rBe the relative dielectric constant of physiological saline, ε ₀It is permittivity of vacuum, η is the viscosity of physiological saline, i is an imaginary unit, ω detects the ultrasound wave angular frequency, and υ is the friction factor between cell electrostatic double layer and the physiological saline, and n is the number density of element in the electrolytic solution, k is a Boltzmann constant, T is an absolute temperature, and κ is a Debye-H ü ckel parameter, κ _mBe the Debye-H ü ckel parameter of cell electrostatic double layer, V _cBe the volume of cell individual, V _sIt is the whole volume that is wrapped in the cell unit of cell electrostatic double layer.

The invention provides another method about step 3), specifically according to following formula:

ΔQ＝IVI _Average×Δt (16)

Δ Q is whole charge migration amount that a ultrasonic pulse causes in the formula (16), and Δ t is the detection time of a ultrasonic pulse, IVI _AverageBe the mean value of IVI in the ultrasonic pulse testing process; With formula (1) substitution formula (16), obtain whole charge migration amount Δ Q in the ultrasonic pulse testing process _IonBe ionic charge migration amount and cell charge migration amount Δ Q _CellSum, as shown in the formula:

ΔQ＝IVI _Average×Δt+CVI _Average×Δt＝ΔQ _ion+ΔQ _cell (17)

In the following formula, CVI _AverageBe the mean value of cell galvanic current, according to formula (17), control Δ t just can the accurate moving electrical characteristics of studying cell on charge level.

The present invention has following beneficial effect:

The method of utilizing the moving electricity of ultrasonic pulse to study the cell dielectric characteristic of the present invention is utilized the effect of ultrasonic pair cell, realization pair cell dielectric property is studied, the surface charge that can accurately detect cell changes, thereby realize the purpose of the biological effect of ultrasound of research cell in real time, and the apparatus structure of realizing the inventive method is simple, this method good reproducibility, pair cell is without any damage.

Description of drawings

Fig. 1 is a cell cellular construction synoptic diagram of the present invention;

Fig. 2 is the implement device theory diagram of the inventive method.

Embodiment

Below in conjunction with accompanying drawing the present invention is done and to describe in further detail:

This method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic of the present invention, specifically carry out according to following steps:

1) sets up the cell model of element

The detected electrokinetic potential of macroscopic view be the electricity by microcosmic in the cell electrostatic double layer cause gravitation and viscosity shear between moving electric reciprocation balance produce.Therefore suppose that diameter is a, and the cell that the surface is uniform-distribution with negative charge is that the ion of d can be wrapped in by penetrating polymer dielectric electrostatic double layer by thickness, this integral body is called a cell unit, and it is a that this cell unit is described to an internal diameter, and external diameter is the spherical flexible glue grain of b=a+d; Suppose that the cell model of element is that quantivalency is the fixed charge aggregate of Z, its skin is uniform-distribution with the electrostatic double layer that density is N; The structural representation of this cell unit as shown in Figure 1.

2) configuration cell suspension

Cell suspension is through centrifugal treating (generally handling 5 times) by fresh plasma, be hybridly prepared into by a certain percentage with physiological saline then, the concentration of the cell suspension of preparation need be carried out corresponding adjusting according to the needs of test cell line, and different test cell lines is to the requirement difference of concentration.

When the preparation cell suspension, haemocyte after centrifugal can be inserted in the test tube according to the different volumes break into portions, in every test tube, pour physiological saline into then, make each cell suspension sample cumulative volume reach identical, promptly get the blood cell suspension sample of variable concentrations, the concentration of above sample is by the cell counting count board counting and calculates.

3) detect cell oscillating current CVI

Making angular frequency is that the ultrasonic pulse of ω acts on respectively on cell suspension and the physiological saline.

In the oscillation pressure gradient fields that applies be

Effect under, this cell unit is that η and relative dielectric constant are ε a viscosity _rEven matter physiological saline electrolytic solution in move with speed U.Wherein the pressure gradient field can obtain by the demarcation to the ultrasonic sound intensity; The viscosity and the specific inductive capacity of even matter physiological saline electrolyte solution all can record by pertinent instruments.

Electric current summation TVI in the detection cell suspension and the ion oscillating current IVI in the physiological saline; Calculate cell oscillating current CVI according to following formula:

TVI＝IVI+CVI； (1)

4) analysis of cells dielectric property

According to the moving electric theory of colloid, calculate the dynamic electrophoretic mobility μ (ω) of cell, again according to the relation between dynamic electrophoretic mobility μ (ω) and the cell electrostatic double layer current potential, obtain the Donnan current potential Ψ of cell electrostatic double layer _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _OThereby, realize the research of pair cell dielectric property.Specifically calculate the dynamic electrophoretic mobility μ (ω) of cell according to following formula:

$\mathrm{IVI}=\frac{\mathrm{zen}}{{\mathrm{\ρ}}_0}(\frac{m_{+}-{\mathrm{\ρ}}_0{V}_{+}}{{\mathrm{\λ}}_{+}}-\frac{m_{-}-{\mathrm{\ρ}}_0{V}_{-}}{{\mathrm{\λ}}_{-}})\mathrm{\ΔP}---\left(2\right)$

In the formula (2), z is the quantivalency of element in the electrolytic solution, and e is the unit charge electric weight, and n is an electrolyte concentration in the physiological saline, ρ ₀Be the concentration of physiological saline, m ₊, V ₊Be respectively cationic quality and quantivalency in the physiological saline, m _-, V _-Be respectively anionic quality and quantivalency in the physiological saline, Δ P is the conductivity of physiological saline; In the formula (3),

Be the volume fraction of cell individual,

Be the volume fraction of cell electrostatic double layer, ρ _CAnd ρ _SBe respectively the mass density of cell and electrostatic double layer;

The drag coefficient λ of negative ions in the formula (2) ₊And λ _-Respectively with corresponding negative ions limit conductance

With

Relevant, calculate according to following formula:

${\mathrm{\λ}}_{\±}=\frac{N_A{e}^{2}z}{{\mathrm{\Λ}}_{\±}^0}---\left(4\right)$

N in the formula (4) _ABe avogadros constant, obtain the dynamic electrophoretic mobility μ (ω) of cell according to above formula.

In step 4), calculate the Donnan current potential Ψ of cell electrostatic double layer in addition according to following formula _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _O:

$\mathrm{\μ}\left(\mathrm{\ω}\right)=\frac{2{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0}{3\mathrm{\η}}\left[\frac{1-\mathrm{i\γb}}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right](1+\frac{a^3}{2b^3})$

$\×\left[\frac{{\mathrm{\Ψ}}_0/{\mathrm{\κ}}_m+{\mathrm{\Ψ}}_{\mathrm{DON}}/\mathrm{\β}}{1/{\mathrm{\κ}}_m+1/\mathrm{\β}}\right]$

$+\left[\frac{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)(1-a^3/b^3)}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right]\frac{\mathrm{ZeN}}{\mathrm{\η}{\mathrm{\β}}^2}---\left(5\right)$

Wherein:

${\mathrm{\Ψ}}_{\mathrm{DON}}=\frac{\mathrm{kT}}{\mathrm{ze}}\ln [\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]---\left(6\right)$

${\mathrm{\Ψ}}_0=\frac{\mathrm{kT}}{\mathrm{ze}}\left(\ln \right[\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]$

$+\frac{2\mathrm{zn}}{\mathrm{ZN}}[1-{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}])---\left(7\right)$

${\mathrm{\κ}}_m=\mathrm{\κ}{[1+{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2]}^{1/4}---\left(8\right)$

$\mathrm{\κ}={\left(\frac{2z^2{e}^{2}n}{{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0\mathrm{kT}}\right)}^{1/2}---\left(9\right)$

$\mathrm{\λ}={\left(\frac{\mathrm{\υ}}{\mathrm{\η}}\right)}^{1/2}---\left(10\right)$

$\mathrm{\γ}=(1+i)\sqrt{\frac{\mathrm{\ω}{\mathrm{\ρ}}_0}{2\mathrm{\η}}}---\left(11\right)$

$\mathrm{\β}=\mathrm{\λ}\sqrt{1-{\left(\frac{\mathrm{\γ}}{\mathrm{\λ}}\right)}^2}---\left(12\right)$

$\mathrm{\Γ}=\frac{{\mathrm{\γ}}^2[V_c({\mathrm{\ρ}}_c-{\mathrm{\ρ}}_0)+V_s({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_0)]}{6\mathrm{\πb}{\mathrm{\ρ}}_0}---\left(13\right)$

$f_c={\left(\frac{a}{b}\right)}^3---\left(14\right)$

$f_s=\frac{V_s}{4\mathrm{\π}{b}^3/3}---\left(15\right)$

More than ε in each formula _rBe the relative dielectric constant of physiological saline, ε ₀It is permittivity of vacuum, η is the viscosity of physiological saline, i is an imaginary unit, ω detects the ultrasound wave angular frequency, and υ is the friction factor between cell electrostatic double layer and the physiological saline, and n is the number density of element in the electrolytic solution, k is a Boltzmann constant, T is an absolute temperature, and κ is a Debye-H ü ckel parameter, κ _mBe the Debye-H ü ckel parameter of cell electrostatic double layer, V _cBe the volume of cell individual, V _sIt is the whole volume that is wrapped in the cell unit of cell electrostatic double layer.

The present invention proposes another and is different from above-mentioned steps 4 in addition) method: after step 3) is finished, according to following formula:

ΔQ＝IVI _Average×Δt (16)

Δ Q is whole charge migration amount that a ultrasonic pulse causes in the formula (16), and Δ t is the detection time of a ultrasonic pulse, IVI _AverageBe the mean value of IVI in the ultrasonic pulse testing process; With formula (1) substitution formula (16), obtain whole charge migration amount Δ Q in the ultrasonic pulse testing process _IonBe ionic charge migration amount and cell charge migration amount Δ Q _CellSum, as shown in the formula:

ΔQ＝IVI _Average×Δt+CVI _Average×Δt＝ΔQ _ion+ΔQ _cell (17)

In the following formula, CVI _AverageBe the mean value of cell galvanic current, according to formula (17), control Δ t just can the accurate moving electrical characteristics of studying cell on charge level.

Referring to Fig. 2, method of the present invention can based on as shown in the figure the device the block diagram principle realize,

Ultrasonic transducer is closely embedded in the counterweight bearing, and the bottom closely contacts acoustic absorbant, prevents ultrasonic reflection; Ultrasonic transducer two electrodes connect the controllable signal source, can make ultrasonic transducer emission ultrasonic pulse or continuous ultrasound ripple; Contain in the sap cavity and hold the cell suspension sample, as the Ultrasonic Detection object; The sampling electrode contacts fully with the sample liquid level, reduces sampling error; Micro-current sensing circuit is used for accurately detecting the moving electric signal of cell; Capture card is used for acquisition testing signal and be transferred to computing machine, carries out wave form analysis.

Claims (4)

1. a method of utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic is characterized in that, may further comprise the steps:

1) sets up the cell model of element

Suppose that diameter is a, and the cell that the surface is uniform-distribution with negative charge is that the ion of d can be wrapped in by penetrating polymer dielectric electrostatic double layer by thickness, this integral body is called a cell unit, and it is a that this cell unit is described to an internal diameter, and external diameter is the spherical flexible glue grain of b=a+d; Suppose that the cell model of element is that quantivalency is the fixed charge aggregate of Z, its skin is uniform-distribution with the electrostatic double layer that density is N;

2) configuration cell suspension

Fresh plasma through after the centrifugal treating, is hybridly prepared into cell suspension with physiological saline;

3) detect cell oscillating current CVI

Making angular frequency is that the ultrasonic pulse of ω acts on respectively on cell suspension and the physiological saline, detects electric current summation TVI in the cell suspension and the ion oscillating current IVI in the physiological saline; Calculate cell oscillating current CVI according to following formula:

TVI＝IVI+CVI； (1)

4) analysis of cells dielectric property

According to the moving electric theory of colloid, calculate the dynamic electrophoretic mobility μ (ω) of cell, again according to the relation between dynamic electrophoretic mobility μ (ω) and the cell electrostatic double layer current potential, obtain the Donnan current potential Ψ of cell electrostatic double layer _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _O

2. the method for utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic according to claim 1 is characterized in that, in the step 4), calculates the dynamic electrophoretic mobility μ (ω) of cell according to following formula:

$\mathrm{IVI}=\frac{\mathrm{zen}}{{\mathrm{\ρ}}_0}(\frac{m_{+}-{\mathrm{\ρ}}_0{V}_{+}}{{\mathrm{\λ}}_{+}}-\frac{m_{-}-{\mathrm{\ρ}}_0{V}_{-}}{{\mathrm{\λ}}_{-}})\mathrm{\ΔP}---\left(2\right)$

In the formula (2), z is the quantivalency of element in the electrolytic solution, and e is the unit charge electric weight, and n is an electrolyte concentration in the physiological saline, ρ ₀Be the concentration of physiological saline, m ₊, V ₊Be respectively cationic quality and quantivalency in the physiological saline, m _-, V _-Be respectively anionic quality and quantivalency in the physiological saline, Δ P is the conductivity of physiological saline; In the formula (3),

Be the volume fraction of cell individual, Be the volume fraction of cell electrostatic double layer, ρ _CAnd ρ _SBe respectively the mass density of cell and electrostatic double layer;

The drag coefficient λ of negative ions in the formula (2) ₊And λ _-Respectively with corresponding negative ions limit conductance With

Relevant, calculate according to following formula:

${\mathrm{\λ}}_{\±}=\frac{N_A{e}^{2}z}{{\mathrm{\Λ}}_{\±}^0}---\left(4\right)$

N in the formula (4) _ABe avogadros constant, obtain the dynamic electrophoretic mobility μ (ω) of cell according to above formula.

3. the method for utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic according to claim 1 and 2 is characterized in that, in the step 4), calculates the Donnan current potential Ψ of cell electrostatic double layer according to following formula _TONAnd the current potential Ψ at cell electrostatic double layer and edge, normal saline solution boundary _O:

$\mathrm{\μ}\left(\mathrm{\ω}\right)=\frac{2{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0}{3\mathrm{\η}}\left[\frac{1-\mathrm{i\γb}}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right](1+\frac{a^3}{2b^3})$

$\×\left[\frac{{\mathrm{\Ψ}}_0/{\mathrm{\κ}}_m+{\mathrm{\Ψ}}_{\mathrm{DON}}/\mathrm{\β}}{1/{\mathrm{\κ}}_m+1/\mathrm{\β}}\right]$

$+\left[\frac{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)(1-a^3/b^3)}{1-\mathrm{i\γb}-({\mathrm{\γ}}^2{b}^2/3)-\mathrm{\Γ}}\right]\frac{\mathrm{ZeN}}{\mathrm{\η}{\mathrm{\β}}^2}---\left(5\right)$

Wherein:

${\mathrm{\Ψ}}_{\mathrm{DON}}=\frac{\mathrm{kT}}{\mathrm{ze}}\ln [\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]---\left(6\right)$

${\mathrm{\Ψ}}_0=\frac{\mathrm{kT}}{\mathrm{ze}}\left(\ln \right[\frac{\mathrm{ZN}}{2\mathrm{zn}}+{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}]$

$+\frac{2\mathrm{zn}}{\mathrm{ZN}}[1-{\{{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2+1\}}^{1/2}])---\left(7\right)$

${\mathrm{\κ}}_m=\mathrm{\κ}{[1+{\left(\frac{\mathrm{ZN}}{2\mathrm{zn}}\right)}^2]}^{1/4}---\left(8\right)$

$\mathrm{\κ}={\left(\frac{2z^2{e}^{2}n}{{\mathrm{\ϵ}}_r{\mathrm{\ϵ}}_0\mathrm{kT}}\right)}^{1/2}---\left(9\right)$

$\mathrm{\λ}={\left(\frac{\mathrm{\υ}}{\mathrm{\η}}\right)}^{1/2}---\left(10\right)$

$\mathrm{\γ}=(1+i)\sqrt{\frac{\mathrm{\ω}{\mathrm{\ρ}}_0}{2\mathrm{\η}}}---\left(11\right)$

$\mathrm{\β}=\mathrm{\λ}\sqrt{1-{\left(\frac{\mathrm{\γ}}{\mathrm{\λ}}\right)}^2}---\left(12\right)$

$\mathrm{\Γ}=\frac{{\mathrm{\γ}}^2[V_c({\mathrm{\ρ}}_c-{\mathrm{\ρ}}_0)+V_s({\mathrm{\ρ}}_s-{\mathrm{\ρ}}_0)]}{6\mathrm{\πb}{\mathrm{\ρ}}_0}---\left(13\right)$

$f_c={\left(\frac{a}{b}\right)}^3---\left(14\right)$

$f_s=\frac{V_s}{4\mathrm{\π}{b}^3/3}---\left(15\right)$

More than ε in each formula _rBe the relative dielectric constant of physiological saline, ε ₀It is permittivity of vacuum, η is the viscosity of physiological saline, i is an imaginary unit, ω detects the ultrasound wave angular frequency, and υ is the friction factor between cell electrostatic double layer and the physiological saline, and n is the number density of element in the electrolytic solution, k is a Boltzmann constant, T is an absolute temperature, and κ is a Debye-H ü ckel parameter, κ _mBe the Debye-H ü ckel parameter of cell electrostatic double layer, V _cBe the volume of cell individual, V _sIt is the whole volume that is wrapped in the cell unit of cell electrostatic double layer.

4. the method for utilizing the moving electricity research of ultrasonic pulse cell dielectric characteristic according to claim 1 is characterized in that, in the step 3), according to following formula:

ΔQ＝IVI _Average×Δt (16)

Δ Q is whole charge migration amount that a ultrasonic pulse causes in the formula (16), and Δ t is the detection time of a ultrasonic pulse, IVI _AverageBe the mean value of IVI in the ultrasonic pulse testing process; With formula (1) substitution formula (16), obtain whole charge migration amount Δ Q in the ultrasonic pulse testing process _IonBe ionic charge migration amount and cell charge migration amount Δ Q _CellSum, as shown in the formula:

ΔQ＝IVI _Average×Δt+CVI _Average×Δt＝ΔQ _ion+ΔQ _cell (17)

In the following formula, CVI _AverageBe the mean value of cell galvanic current, according to formula (17), control Δ t just can the accurate moving electrical characteristics of studying cell on charge level.

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