ドナン平衡、Donnan平衡

WordNet

a stable situation in which forces cancel one another
a sensory system located in structures of the inner ear that registers the orientation of the head (同)labyrinthine sense, vestibular sense, sense of balance, sense_of_equilibrium

PrepTutorEJDIC

(力・勢力・作用などの)釣り合い,均衡;(心の)平静

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/03/07 00:39:46」(JST)

wiki en

[Wiki en表示]

Donnan equilibrium across a cell membrane (schematic)

The Gibbs–Donnan effect (also known as the Donnan effect, Donnan law, Donnan equilibrium, or Gibbs–Donnan equilibrium) is a name for the behavior of charged particles near a semi-permeable membrane that sometimes fail to distribute evenly across the two sides of the membrane.^[1] The usual cause is the presence of a different charged substance that is unable to pass through the membrane and thus creates an uneven electrical charge.^[2] For example, the large anionic proteins in blood plasma are not permeable to capillary walls. Because small cations are attracted, but are not bound to the proteins, small anions will cross capillary walls away from the anionic proteins more readily than small cations.

Some ionic species can pass through the barrier while others cannot. The solutions may be gels or colloids as well as solutions of electrolytes, and as such the phase boundary between gels, or a gel and a liquid, can also act as a selective barrier. The electric potential arising between two such solutions is called the Donnan potential.

The effect is named after the American physicist Josiah Willard Gibbs and the British chemist Frederick G. Donnan.^[3]

The Donnan equilibrium is prominent in the triphasic model for articular cartilage proposed by Mow and Lai, as well as in electrochemical fuel cells and dialysis.

The Donnan effect is extra osmotic pressure attributable to cations (Na⁺ and K⁺) attached to dissolved plasma proteins.

Example

The presence of a charged impermeant ion (for example, a protein) on one side of a membrane will result in an asymmetric distribution of permeant charged ions. The Gibbs–Donnan equation at equilibrium states (assuming permeant ions are Na⁺ and Cl^-):

[Na_{Side 1}] × [Cl_{Side 1}] = [Na_{Side 2}] × [Cl_{Side 2}]

Example:

Start	Equilibrium
Side 1: 9 Na, 9 Cl Side 2: 9 Na, 9 Protein	Side 1: 6 Na, 6 Cl Side 2: 12 Na, 3 Cl, 9 Protein

References

^ http://www.cartage.org.lb/en/themes/Reference/dictionary/Biologie/G/13.html, retrieved 28 August 2006
^ The Gibbs–Donnan Equilibrium..., D.C. Mikulecky, retrieved 28 August 2006
^ F.G. Donnan (1911) "Theorie der Membrangleichgewichte und Membranpotentiale bei Vorhandensein von nicht dialysierenden Elektrolyten. Ein Beitrag zur physikalisch-chemischen Physiologie" (The theory of membrane equilibrium and membrane potential in the presence of a non-dialyzable electrolyte. A contribution to physical-chemical physiology), Zeitschrift für Elektrochemie und angewandte physikalische Chemie, 17 (10) : 572-581.

IUPAC Compendium of Chemical Terminology 2nd Edition (1997)
Van C. Mow Basic orthopaedic biomechanics and mechano-biology, 2nd Ed. Lippincott Williams & Wilkins, Philadelphia, 2005

External links

Gibbs–Donnan Effect Simulator
Difference between observed and expected oncotic pressure values

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. 正常な状態における胸水のターンオーバー機序 mechanisms of pleural liquid turnover in the normal state
2. 遺伝関連研究：原理および応用 genetic association studies principles and applications
3. 左室収縮機能測定のための非侵襲的方法 noninvasive methods for measurement of left ventricular systolic function
4. 持続的腎代替療法：概要 continuous renal replacement therapies overview
5. 肝胆道のCT撮影 computed tomography of the hepatobiliary tract

English Journal

Method of moments for computational microemulsion analysis and prediction in tertiary oil recovery.

Fraaije JG, Tandon K, Jain S, Handgraaf JW, Buijse M.SourceSoft Matter Chemistry Group, Leiden Institute of Chemistry, Leiden University , P.O. Box 9502, 2300 RA Leiden, The Netherlands.
Langmuir : the ACS journal of surfaces and colloids.Langmuir.2013 Feb 19;29(7):2136-51. doi: 10.1021/la304505u. Epub 2013 Feb 6.
We discuss the application of Helfrich's surface torque density concept to microemulsion design and analysis from three different angles: (i) from the point of view of coarse-grained molecular simulations, using Dissipative Particle Dynamics, including charge interactions and added salt, (ii) using
PMID 23297863

Testing Copper-Speciation Predictions in Freshwaters over a Wide Range of Metal-Organic Matter Ratios.

Ahmed IA, Hamilton Taylor J, Lofts S, Meeussen JC, Lin C, Zhang H, Davison W.SourceThe University of Lancaster , Lancaster Environment Centre, Lancaster, LA1 4YQ, United Kingdom.
Environmental science & technology.Environ Sci Technol.2013 Feb 5;47(3):1487-95. doi: 10.1021/es304150n. Epub 2013 Jan 18.
The harsh chemical conditions involved in the isolation of fulvic acids (FA) and humic acids (HA) have been identified as a possible contributing factor to the significant mismatch between in situ measurements and model predictions of trace metal speciation in freshwaters, resulting from the use of
PMID 23286231

The effect of culture condition and ionic strength on proton adsorption at the surface of the extreme thermophile Acidianus manzaensis.

He Z, Yang Y, Zhou S, Zhong H, Sun W.SourceSchool of Minerals Processing and Bioengineering, Central South University, No. 932, Lushan South Road, Changsha 410083, China.
Colloids and surfaces. B, Biointerfaces.Colloids Surf B Biointerfaces.2013 Feb 1;102:667-73. doi: 10.1016/j.colsurfb.2012.09.028. Epub 2012 Sep 24.
Some previously published studies have used surface complexation theory to model proton adsorption in mesophilic bacteria. However, few experiments, to date, have investigated the effects of cultivation conditions and ionic strength on proton interactions among extreme thermophile archaea. In this s
PMID 23107945

Japanese Journal

イオン性ハイドロゲルの電場における運動動力学

清田佳美
東洋大学紀要. 自然科学篇 (56), 53-64, 2012-03-00
NAID 40019279583

荷電膜におけるイオン輸送現象に関する研究

谷岡明彦
日本海水学会誌 = Bulletin of the Society of Sea Water Science, Japan 65(5), 294-300, 2011-10-01
NAID 10029481836

Dissociation Equilibrium in Chelating Sepharose Fast Flow Gel

UDDIN Mohammad Washim,TAKANO Maki,AKAKABE Setsuko,HOSHINO Kazuhiro,MOROHASHI Shoichi
Journal of chemical engineering of Japan 40(9), 693-697, 2007-09-01
… An experimental investigation concerning the dissociation equilibrium in a gel was carried out by using Chelating Sepharose Fast Flow gel and buffer solutions. … It was found that the relationship between the degree of dissociation of fixed two –CH<SUB>2</SUB>COOH groups in gel and the concentration of hydrogen ions in the outer aqueous phase could be correlated by an equation based on the dissociation equilibrium. …
NAID 10019953371