Thaj chaw ntawm cov tshuab uas kawm txog cov yam ntxwv ntawm deformation thiab ntws ntawm cov xov xwm txuas ntxiv, ib qho ntawm cov neeg sawv cev uas tsis yog-Newtonian kua nrog cov qauv viscosity, yog rheology. Hauv kab lus no, peb xav txog cov khoom rheological ntawm cov ntshav. Yuav ua li cas thiaj paub meej.
Definition
Ib yam uas tsis yog-Newtonian kua yog ntshav. Nws yog hu ua plasma yog tias nws tsis muaj cov ntsiab lus tsim. Serum yog plasma uas tsis muaj fibrinogen.
Hemorheology, lossis rheology, kawm txog cov qauv siv tshuab, tshwj xeeb tshaj yog yuav ua li cas lub cev thiab colloidal zog ntawm cov ntshav hloov thaum lub sijhawm sib txawv ntawm qhov sib txawv thiab nyob rau hauv ntau qhov chaw ntawm lub txaj vascular. Nws cov khoom, lub xeev ua haujlwm ntawm cov hlab ntsha, lub contractility ntawm lub plawv txiav txim qhov txav ntawm cov ntshav hauv lub cev. Thaum lub linear flow velocity tsawg, cov ntshav hais txav mus rau lub axis ntawm lub nkoj thiab ntawm ib leeg. Nyob rau hauv cov ntaub ntawv no, cov dej ntws muaj ib txheej txheej, thiab ntws yog hu ua laminar. Yog li ntawd yog dab tsirheological zog? Xav paub ntau ntxiv tom qab.
Tus lej Reynolds yog dab tsi?
Nyob rau hauv qhov kev tshwm sim ntawm ib qho kev nce nyob rau hauv linear tshaj tawm thiab tshaj ib tug tej yam nqi, uas txawv rau tag nrho cov hlab ntsha, lub laminar ntws yuav tig mus rau hauv ib tug vortex, chaotic, hu ua turbulent. Tus nqi ntawm kev hloov ntawm laminar mus rau turbulent motion txiav txim Reynolds tus naj npawb, uas yog kwv yees li 1160 rau cov hlab ntsha. Raws li Reynolds cov zauv, turbulence tsuas yog tshwm sim nyob rau hauv cov chaw uas loj hlab ntsha ceg, thiab nyob rau hauv lub aorta. Cov kua txav laminar hla ntau lub nkoj.
Speed and shear stress
Tsis yog qhov ntim thiab cov kab nrawm nrawm ntawm cov ntshav txaus yog qhov tseem ceeb, ob qhov tseem ceeb dua qhov ua rau lub cev txav mus rau lub nkoj: nrawm thiab kev ntxhov siab. Shear stress characterizes tus quab yuam ua ntawm ib chav tsev ntawm vascular nto nyob rau hauv lub tangential kev taw qhia rau saum npoo, ntsuas nyob rau hauv pascals los yog dynes / cm2. Tus nqi shear yog ntsuas nyob rau hauv reciprocal vib nas this (s-1), uas txhais tau hais tias nws yog qhov loj ntawm qhov gradient ntawm qhov nrawm ntawm kev txav ntawm cov khaubncaws sab nraud povtseg ntawm cov kua txav mus rau qhov sib npaug ntawm ib chav tsev nyob ntawm lawv.
Ntawm qhov ntsuas dab tsi ua rheological zog nyob ntawm?
Qhov piv ntawm kev ntxhov siab rau tus nqi txiav txiav cov ntshav viscosity, ntsuas hauv mPas. Rau cov kua dej, cov viscosity nyob ntawm qhov sib txawv ntawm 0.1-120s-1. Yog tias tus nqi shear yog >100s-1, qhov viscosity hloov tsis tau hais, thiab tom qab ncav cuag tus nqi ntawm 200s-1 yuav luag tsis muajhloov. Tus nqi ntsuas ntawm qhov siab shear yog hu ua asymptotic. Lub ntsiab yam tseem ceeb uas cuam tshuam rau viscosity yog deformability ntawm cell ntsiab, hematocrit thiab aggregation. Thiab muab qhov tseeb tias muaj cov qe ntshav liab ntau dua piv rau cov platelets thiab cov qe ntshav dawb, lawv feem ntau txiav txim siab los ntawm cov qe ntshav liab. Qhov no tau tshwm sim hauv cov khoom rheological ntawm cov ntshav.
Viscosity factor
Qhov tseem ceeb tshaj plaws uas txiav txim siab viscosity yog qhov ntim ntawm cov qe ntshav liab, lawv qhov nruab nrab ntim thiab cov ntsiab lus, qhov no hu ua hematocrit. Nws yog kwv yees li 0.4-0.5 l / l thiab txiav txim siab los ntawm centrifugation los ntawm cov qauv ntshav. Plasma yog cov kua dej Newtonian, qhov viscosity uas txiav txim siab qhov muaj pes tsawg leeg ntawm cov protein, thiab nws nyob ntawm qhov kub thiab txias. Viscosity feem ntau cuam tshuam los ntawm globulins thiab fibrinogen. Qee cov kws tshawb fawb ntseeg tias qhov tseem ceeb tshaj plaws uas ua rau muaj kev hloov pauv hauv plasma viscosity yog qhov piv ntawm cov proteins: albumin / fibrinogen, albumin / globulins. Qhov nce no tshwm sim thaum sib sau ua ke, txiav txim siab los ntawm tus cwj pwm tsis yog-Newtonian ntawm tag nrho cov ntshav, uas txiav txim siab lub peev xwm sib sau ua ke ntawm cov qe ntshav liab. Physiological aggregation ntawm erythrocytes yog ib txoj kev thim rov qab. Qhov ntawd yog qhov nws yog - cov khoom rheological ntawm cov ntshav.
Kev tsim cov sib sau los ntawm erythrocytes nyob ntawm txhua yam, hemodynamic, electrostatic, plasma thiab lwm yam. Niaj hnub no, muaj ntau txoj kev xav uas piav qhia txog cov txheej txheem ntawm erythrocyte aggregation. Qhov zoo tshaj plaws niaj hnub no yog txoj kev xav ntawm kev sib txuas. Lub tshuab uas txuas hniav los ntawm cov proteins loj molecular, fibrinogen, Y-globulins yog adsorbed rau ntawm qhov chaw ntawm erythrocytes. Lub net aggregation quab yuam yog qhov sib txawv ntawm lub zog shear (ua rau disaggregation), electrostatic repulsion txheej ntawm erythrocytes, uas tsis zoo them, thiab lub zog ntawm cov choj. Lub tshuab ua lub luag haujlwm rau kev txhim kho ntawm qhov tsis zoo them macromolecules ntawm erythrocytes, uas yog, Y-globulin, fibrinogen, tseem tsis tau nkag siab tag nrho. Muaj kev xav tias cov molecules tau txuas vim yog qhov tawg ntawm van der Waals rog thiab tsis muaj zog hydrogen bonds.
Dab tsi pab txhawm rau ntsuas cov ntshav rheological?
Vim li cas erythrocyte aggregation tshwm sim?
Kev piav qhia ntawm erythrocyte aggregation kuj tau piav qhia los ntawm kev depletion, qhov tsis muaj cov protein ntau molecular ze rau erythrocytes, nyob rau hauv kev sib txuas nrog cov kev sib cuam tshuam ntawm lub siab, zoo ib yam li osmotic siab ntawm cov tshuaj macromolecular, uas ua rau muaj kev cuam tshuam ntawm kev sib txuam ntawm lub siab. convergence ntawm suspended hais. Tsis tas li ntawd, muaj ib txoj kev xav txuas erythrocyte aggregation nrog erythrocyte yam, ua rau txo qis hauv zeta peev xwm thiab kev hloov pauv hauv cov metabolism thiab cov duab ntawm erythrocytes.
Vim kev sib raug zoo ntawm cov viscosity thiab kev sib sau ua ke ntawm erythrocytes, txhawm rau txheeb xyuas cov txiaj ntsig ntawm cov ntshav thiab cov yam ntxwv ntawm nws txoj kev txav mus los ntawm cov hlab ntsha, nws yog ib qho tsim nyog yuav tsum tau ua qhov kev ntsuam xyuas dav dav ntawm cov ntsuas no. Ib txoj hauv kev zoo tshaj plaws thiab siv tau yooj yim rau kev ntsuas kev sib sau yog qhov kev ntsuas ntawm tus nqi ntawm erythrocyte.sedimentation. Txawm li cas los xij, cov qauv ntawm qhov kev sim no tsis qhia ntau, vim nws tsis suav nrog cov yam ntxwv rheological.
ntsuas ntsuas
Raws li kev tshawb fawb ntawm cov ntshav rheological yam ntxwv thiab cov yam ntxwv uas cuam tshuam rau lawv, nws tuaj yeem txiav txim siab tias qhov kev ntsuas ntawm cov ntshav rheological cuam tshuam los ntawm lub xeev sib sau ua ke. Niaj hnub no, cov kws tshawb fawb tau them nyiaj ntau dua rau kev kawm txog cov khoom siv microrheological ntawm cov kua no, txawm li cas los xij, viscometry kuj tseem tsis tau poob nws qhov cuam tshuam. Cov txheej txheem tseem ceeb rau kev ntsuas cov khoom ntawm cov ntshav tuaj yeem muab faib ua ob pawg: nrog rau homogeneous kev nyuaj siab thiab strain teb - cone-plane, disk, cylindrical thiab lwm yam rheometers nrog txawv geometry ntawm cov khoom ua haujlwm; nrog rau thaj tsam ntawm deformations thiab kev ntxhov siab kuj tsis sib xws - raws li kev sau npe ntawm acoustic, hluav taws xob, kev vibrations, cov cuab yeej ua haujlwm raws li Stokes txoj kev, capillary viscometers. Qhov no yog qhov ntsuas rheological ntawm cov ntshav, ntshav thiab ntshav ntshav.
Ob hom viscometers
Ob hom viscometers tam sim no yog qhov dav tshaj plaws: rotational thiab capillary. Viscometers kuj tseem siv, lub tog raj kheej sab hauv uas ntab hauv cov kua tau sim. Tam sim no lawv tau koom nrog ntau yam kev hloov kho ntawm kev sib hloov rheometers.
Zoo kawg
Nws tseem tsim nyog sau cia tias qhov kev paub zoo hauv kev txhim kho rheological thev naus laus zis tsuas yog ua rau nws tuaj yeem kawm txog biochemical thiab biophysical. Cov ntshav muaj zog los tswj microregulation hauv metabolic thiab hemodynamic ntshawv siab. Txawm li cas los xij, txoj kev loj hlob ntawm txoj hauv kev rau kev tshuaj xyuas ntawm hemorheology, uas yuav cuam tshuam txog kev sib sau thiab rheological ntawm cov kua Newtonian, yog tam sim no cuam tshuam.
