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 Team pinpoints genes that make plant stem cells, revealing origin of beefsteak tomatoes
26.05.2015 | Cold Spring Harbor Laboratory

nachricht DNA double helix does double duty in assembling arrays of nanoparticles
26.05.2015 | DOE/Brookhaven National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Eine Bremse gegen epileptische Anfälle in Nervenzellen

In jedem Augenblick werden an Billiarden Synapsen unseres Gehirns chemische Signale erzeugt, die einzelnen Nervenzellen feuern dabei bis zu 1000 mal in der Sekunde. Wie ihnen diese Höchstleistung gelingt ohne dabei epileptische Anfälle zu erzeugen, haben Wissenschaftler am Leibniz-Institut für Molekulare Pharmakologie in Berlin nun ein Stück weit aufgeklärt. Das Ergebnis könnte zu einem besseren Verständnis nicht nur der Epilepsie, sondern auch anderer neurologischer Erkrankungen wie der Alzheimerschen Krankheit beitragen.

Mit jedem elektrischen Impuls schüttet eine Nervenzelle Neurotransmitter in den synaptischen Spalt aus und trägt so das Signal weiter. Sie hält dafür einen...

Im Focus: Kieler Forschende bauen die kleinsten Maschinen der Welt

Die DFG stellt Millionenförderung für die Entwicklung neuartiger Medikamente und Materialien an der Christian-Albrechts-Universität zu Kiel (CAU) bereit.

Großer Jubel an der Christian-Albrechts-Universität zu Kiel (CAU): Wie die Deutsche Forschungsgemeinschaft (DFG) heute (Donnerstag, 21. Mai) bekannt gab,...

Im Focus: Basler Physiker entwickeln Methode zur effizienten Signalübertragung aus Nanobauteilen

Physiker haben eine innovative Methode entwickelt, die den effizienten Einsatz von Nanobauteilen in elektronische Schaltkreisen ermöglichen könnte. Sie entwickelten dazu eine Anordnung, bei der ein Nanobauteil mit zwei elektrischen Leitern verbunden ist. Diese bewirken eine hocheffiziente Auskopplung des elektrischen Signals. Die Wissenschaftler vom Departement Physik und dem Swiss Nanoscience Institute der Universität Basel haben ihre Ergebnisse zusammen mit Kollegen der ETH Zürich in der Fachzeitschrift «Nature Communications» publiziert.

Elektronische Bauteile werden immer kleiner. In Forschungslabors werden bereits Bauelemente von wenigen Nanometern hergestellt, was ungefähr der Grösse von...

Im Focus: Basel Physicists Develop Efficient Method of Signal Transmission from Nanocomponents

Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.

Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...

Im Focus: Phagen übertragen Antibiotikaresistenzen auf Bakterien – Nachweis auf Geflügelfleisch

Bakterien entwickeln immer häufiger Resistenzen gegenüber Antibiotika. Es gibt unterschiedliche Erklärungen dafür, wie diese Resistenzen in die Bakterien gelangen. Forschende der Vetmeduni Vienna fanden sogenannte Phagen auf Geflügelfleisch, die Antibiotikaresistenzen auf Bakterien übertragen können. Phagen sind Viren, die ausschließlich Bakterien infizieren können. Für Menschen sind sie unschädlich. Phagen könnten laut Studie jedoch zur Verbreitung von Antibiotikaresistenzen beitragen. Die Erkenntnisse sind nicht nur für die Lebensmittelproduktion sondern auch für die Medizin von Bedeutung. Die Studie wurde in der Fachzeitschrift Applied and Environmental Microbiology veröffentlicht.

Antibiotikaresistente Bakterien stellen weltweit ein bedeutendes Gesundheitsrisiko dar. Gängige Antibiotika sind bei der Behandlung von Infektionskrankheiten...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Schweigen ist Silber, Diskutieren ist Gold

26.05.2015 | Veranstaltungen

Neue Werkstoffkonzepte für eine nachhaltige Mobilität

26.05.2015 | Veranstaltungen

TU Darmstadt: Gipfel der Verschlüsselung - CROSSING-Konferenz am 1. und 2. Juni in Darmstadt

22.05.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Lungenmedikament macht Mäuse schlank

26.05.2015 | Medizin Gesundheit

Zwölf Siemens-Straßenbahnen für Ulm

26.05.2015 | Unternehmensmeldung

Aufsichtsrat von Eurex Clearing beruft neues Mitglied

26.05.2015 | Unternehmensmeldung