Tag Archives: cars

How To Measure The NanoWorld

A worldwide study involving 20 laboratories has established and standardized a method to measure exact distances within individual biomolecules, down to the scale of one millionth of the width of a human hair. The new method represents a major improvement of a technology called single-molecule FRET (Förster Resonance Energy Transfer), in which the movement and interaction of fluorescently labelled molecules can be monitored in real time even in living cells. So far, the technology has mainly been used to report changes in relative distances – for instance, whether the molecules moved closer together or farther apart. Prof. Dr. Thorsten Hugel of the Institute of Physical Chemistry (University of Freiburg) in Germany is one of the lead scientists of the study, which was recently published in Nature MethodsFRET works similarly to proximity sensors in cars: the closer the object is, the louder or more frequent the beeps become. Instead of relying on acoustics, FRET is based on proximity-dependent changes in the fluorescent light emitted from two dyes and is detected by sensitive microscopes. The technology has revolutionised the analysis of the movement and interactions of biomolecules in living cells.

Hugel and colleagues envisioned that once a FRET standard had been established, unknown distances could be determined with high confidence. By working together, the 20 laboratories involved in the study refined the method in such a way that scientists using different microscopes and analysis software obtained the same distances, even in the sub-nanometer range.

The absolute distance information that can be acquired with this method now enables us to accurately assign conformations in dynamic biomolecules, or even to determine their structures”, says Thorsten Hugel, who headed the study together with Dr. Tim Craggs (University of Sheffield/Great-Britain), Prof. Dr. Claus Seidel (University of Düsseldorf) and Prof. Dr. Jens Michaelis (University of Ulm). Such dynamic structural information will yield a better understanding of the molecular machines and processes that are the basis of life.

Source: https://www.pr.uni-freiburg.de/

Bio-material Stronger Than Steel

At DESY‘s X-ray light source PETRA III, a team led by Swedish researchers has produced the strongest bio-material that has ever been made. The artifical, but bio-degradable cellulose fibres are stronger than steel and even than dragline spider silk, which is usually considered the strongest bio-based material. The team headed by Daniel Söderberg from the KTH Royal Institute of Technology in Stockholm reports the work in the journal ACS Nano of the American Chemical Society. The ultrastrong material is made of cellulose nanofibres (CNF), the essential building blocks of wood and other plant life. Using a novel production method, the researchers have successfully transferred the unique mechanical properties of these nanofibres to a macroscopic, lightweight material that could be used as an eco-friendly alternative for plastic in airplanes, cars, furniture and other products.

 

The resulting fibre seen with a scanning electron microscope (SEM)

Our new material even has potential for biomedicine since cellulose is not rejected by your body”, explains Söderberg.

The scientists started with commercially available cellulose nanofibres that are just 2 to 5 nanometres in diameter and up to 700 nanometres long. A nanometre (nm) is a millionth of a millimetre. The nanofibres were suspended in water and fed into a small channel, just one millimetre wide and milled in steel. Through two pairs of perpendicular inflows additional deionized water and water with a low pH-value entered the channel from the sides, squeezing the stream of nanofibres together and accelerating it.

This process, called hydrodynamic focussing, helped to align the nanofibres in the right direction as well as their self-organisation into a well-packed macroscopic thread. No glue or any other component is needed, the nanofibres assemble into a tight thread held together by supramolecular forces between the nanofibres, for example electrostatic and Van der Waals forces.

Source: http://www.desy.de/