Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Blood is thicker than water -- and blood plasma is, too

19.02.2013
The results are significant because they can help to improve our understanding of medical conditions, such as thrombosis, aneurysms and arteriosclerosis. The research team is publishing its results in Physical Review Letters and the American Physical Society has highlighted the work on its Physics website, placing it on the Focus List of important physics news.

Blood flows differently than water. Anyone who has ever cut themselves knows that blood flows viscously and rather erratically. The similarity between blood and ketchup is something not only filmmakers are aware of. Experts refer to these materials as "non-Newtonian fluids," of which ketchup and blood are prime examples.

These fluids have flow properties that change depending on conditions, with some becoming more viscous, while others become less viscous. Blood (like ketchup) is a "shear thinning fluid" that becomes less viscous with increasing pressure and it is this that allows blood to flow into the narrowest of capillaries. The flow properties of water are, in contrast, essentially constant.

Up until now it has been assumed that the special flow characteristics exhibited by blood were mainly due to the presence of the red blood cells, which account for about 45 percent of the blood's volume. Blood plasma was generally regarded simply as a spectator that played no active role. For decades, researchers have assumed that blood plasma flows like water. After all, plasma, the liquid in which the blood cells are suspended, consists to 92 percent of water. But results from researchers at Saarland University and at the University of Pennsylvania have now shown that plasma is a very special fluid that plays a crucial part in determining how blood flows. The results demonstrate that blood plasma is itself a non-Newtonian fluid.

According to the study's findings, the complex flow behavior of blood plasma could play a crucial role with respect to vascular wall deposits, aneurysms or blood clots. The results from this research may well help to improve computer simulations of this kind of pathological process.

The research team around experimental physicist Christian Wagner and engineer Paulo E. Arratia have studied the flow dynamics of blood experimentally. The work at Saarland University involved experiments in which the blood plasma was allowed to form drops inside a specially built apparatus equipped with high-speed cameras fitted with high-resolution microscope lenses to analyze drop formation. "Our experiments showed that the blood plasma forms threads, that is, it exhibits an extensional viscosity, which is something we do not observe in water," explained Professor Wagner. The plasma shows "viscoelastic" properties, which means that it exhibits both viscous and elastic behavior when deformed, forming threads that are typical of non-Newtonian fluids.

The studies by Professor Arratia and his team at the University of Pennsylvania involved a microfluidic approach in which they developed a model of a microvascular system in order to study the flow properties of blood plasma. Their measurements showed that blood plasma exhibits a flow behavior different to that of water and that plasma can demonstrate a substantially higher flow resistance. "An important part of our study was developing microfluidic instruments sensitive enough to pick up the small differences in viscosity that are the signature of non-Newtonian fluids," explained Professor Arratia.

Experiments performed by Professor Wagner's team in Saarbrücken also showed that blood plasma influences the creation of vortices in flowing blood. These vortices may facilitate the formation of deposits on blood vessel walls which could influence blood clot formation. In one of their experiments, the research team let plasma flow through a narrow channel of the kind found in stenotic (constricted) arteries or in a stent (a medical implant inserted into constricted blood vessels). The vortical structures were detected at the end, but also at the entrance, of the narrow channel and their formation is a direct result of the viscoelastic flow properties of blood plasma.

The research at Saarland University was performed within the Research Training Group "Structure Formation and Transport in Complex Systems" funded by the German Research Foundation (DFG). The research at the University of Pennsylvania was supported by the US National Science Foundation - CBET- 0932449.

Original publication:

M. Brust, C. Schaefer, R. Doerr, L. Pan, M. Garcia, P. E. Arratia, and C. Wagner (2013):
"Rheology of human blood plasma: Viscoelastic versus Newtonian behavior",
Phys. Rev. Lett., 110, 078305 (2013)
DOI: 10.1103/PhysRevLett.110.078305
http://link.aps.org/doi/10.1103/PhysRevLett.110.078305
Physics: Focus: http://physics.aps.org/articles/v6/18 (video)
Contact:
Professor Dr. Christian Wagner
Department of Experimental Physics, Saarland University
Tel.: 0049 (0)681 302-3003 or -2416; E-mail: c.wagner@mx.uni-saarland.de
http://agwagner.physik.uni-saarland.de/
Professor Paulo E. Arratia
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania
Tel.: 001 215 746-2174; E-mail: parratia@seas.upenn.edu
www.seas.upenn.edu/~parratia
Press photographs are available at www.uni-saarland.de/pressefotos and can be used at no charge. Please read and comply with the conditions of use.

Note for radio journalists: Studio-quality telephone interviews can be conducted with researchers at Saarland University using broadcast audio IP codec technology. Interview requests should be addressed to the university's Press and Public Relations Office (+49 (0)681 302-2601).

Christian Wagner | EurekAlert!
Further information:
http://www.uni-saarland.de

More articles from Life Sciences:

nachricht Protein Shake-Up
27.03.2015 | Oak Ridge National Laboratory

nachricht How did the chicken cross the sea?
27.03.2015 | Michigan State University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: FiberLab-Roboter begeistert auf Photonics West in San Francisco

Mit ihrem „humanisierten“ Roboter zeigten Anna Lena Baumann und Wolfgang Schade erstmalig die erfolgreiche Umsetzung der 3D-Navigation über eine neuartige Lasermethode, der Standard Single-Mode-Glasfaser. Mehr als 17.000 Teilnehmer konnten den Roboter und FiberLab, das erste Projekt des Photonik Inkubators in Göttingen, auf der Photonics West in San Francisco kennen lernen.

Mit Hilfe eines in die Kleidung eingenähten Fasersensors wurden Armbewegungen eines Probanden dokumentiert und nach entsprechender Auswertung an den Roboter...

Im Focus: Femto Photonic Production: Neue Verfahren mit Ultrakurzpulslasern für die Fertigung von morgen

Für die deutsche Wirtschaft spielt die Lasertechnik eine herausragende Rolle: Etwa 40 Prozent der weltweit verkauften Strahlquellen und 20 Prozent der Lasersysteme für die Materialbearbeitung stammen aus Deutschland.

Beim Einsatz von Lasern in der Produktion sind deutsche Unternehmen führend. Diese Stärken gilt es zu erhalten und auszubauen. Deswegen hat das...

Im Focus: Theorie der starken Wechselwirkung bestätigt: Supercomputer bestimmt Neutron-Proton-Massendifferenz

Nur weil das Neutron ein klein wenig schwerer ist als das Proton, haben Atomkerne genau die Eigenschaften, die unsere Welt und letztlich unsere Existenz ermöglichen.

80 Jahre nach der Entdeckung des Neutrons ist es einem Team aus Frankreich, Deutschland und Ungarn unter Führung des Wuppertaler Forschers Zoltán Fodor nun...

Im Focus: Neurochip für die Hirnforschung erfolgreich im Markt

Neues Mess- und Stimulationssystem nimmt die Kommunikation von Nervenzellen in Echtzeit auf und ermöglicht damit lang erhoffte Grundlagenforschung

Für die Enträtselung neurologischer und neurodegenerativer Erkrankungen wie Parkinson, Alzheimer, Depression oder verschiedene Erblindungsformen verspricht ein...

Im Focus: Klassisch oder nicht? Physik der Nanoplasmen

Die Wechselwirkung von intensiven Laserpulsen mit Partikeln auf einer Nanometer-Skala resultiert in der Erzeugung eines expandierenden Nanoplasmas.

In der Vergangenheit wurde die Dynamik eines Nanoplasmas typischerweise durch klassische Phänomene wie die thermische Emission von Elektronen beschrieben. Im...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

THETIS - Branchentreff für Meeresenergien

27.03.2015 | Veranstaltungen

1. HAMMER BIOENERGIETAGE

27.03.2015 | Veranstaltungen

Technologietag bei der SCHOTT AG - Neue Strukturierungstechnologien für Dünngläser

26.03.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Motormanagement-System kommuniziert per Modbus

27.03.2015 | HANNOVER MESSE

Ein Elektron auf Tauchgang

27.03.2015 | Physik Astronomie

Material für dichtere Magnetspeicher

27.03.2015 | Materialwissenschaften