Researchers at The University of Queensland, New Zealand, and the University of Münster, Germany, have gained insight into the photosynthesis process at a molecular level through understanding the cyclic electron flow supercomplex, which is a critical part of the photosynthetic machinery in plants. The discovery could help guide the development of next-generation solar biotechnologies.
The team purified and characterised the cyclic electron flow supercomplex from micro-algae, and analysed its structure using electron microscopy. The analysis showed how complexes that harvest light become supercomplexes that allow the plant to adapt to varying light conditions and energy requirements.
‘The cyclic electron flow supercomplex is an excellent example of an evolutionarily highly conserved structure,’ says Professor Hippler, the University of Münster. ‘By the year 2050, we will need 50% more fuel, 70% more food, and 50% more clean water. Technologies based on photosynthetic microalgae have the potential to play an important role in meeting these needs’, says Professor Ben Hankamer of the University of Queensland.
The discovery will help guide the design of next generation solar capture technologies based on micro-algae and a wide range of solar driven biotechnologies. This can help produce food, fuel and clean water.
A novel technique that nudges single atoms to switch places within an atomically thin material could bring scientists another step closer to realizing theoretical physicist Richard Feynman’s vision of building tiny machines from the atom up.
A significant push to develop materials that harness the quantum nature of atoms is driving the need for methods to build atomically precise electronics and sensors. Fabricating nanoscale devices atom by atom requires delicacy and precision, which has been demonstrated by a microscopy team at the Department of Energy’s Oak Ridge National Laboratory.
They used a scanning transmission electron microscope, or STEM, at the lab’s Center for Nanophase Materials Sciences to introduce silicon atoms into a single-atom-thick sheet of graphene. As the electron beam scans across the material, its energy slightly disrupts the graphene’s molecular structure and creates room for a nearby silicon atom to swap places with a carbon atom.
“We observed an electron beam-assisted chemical reaction induced at a single atom and chemical bond level, and each step has been captured by the microscope, which is rare,” said ORNL’s Ondrej Dyck, co-author of a study published in the journal Small that details the STEM demonstration.
Being able to determine magnetic properties of materials with sub-nanometer precision would greatly simplify development of magnetic nano-structures for future spintronic devices. In an article published in Nature Communications Uppsala physicists make a big step towards this goal – they propose and demonstrate a new measurement method capable to detect magnetism from areas as small as 0.5 nm2.
Due to the ever-growing demand for more powerful electronic devices the next generation spintronic components must have functional units that are only a few nanometers large. It is easier to build a new spintronic device, if we can see it in a sufficient detail. This becomes more and more tricky with the rapid advance of nano-technologies, especially when we need not only an overall picture “how the thing looks,” but also know its physical properties at nano-scale. One of instruments capable of such detailed look is a transmission electron microscope.
Electron microscope is a unique experimental tool offering to scientists and engineers a wealth of information about all kinds of materials. Differently from optical microscopes, it uses electrons to study the materials, and thanks to that it achieves an enormous magnification. For example, in crystals one can even observe individual columns of atoms. Electron microscopes routinely provide information about structure, composition and chemistry of materials. Recently researchers found ways to use electron microscopes also for measuring magnetic properties. There, however, atomic resolution has not been reached so far.
A spiky isopod (Akermania besucheti) with an illustration of what its outer shell looks like under electron microscope from Revue suisse de zoologie t.86 (1979).
Tardigrades– the micro-animals whose electron micrographs (like the one above) have done the rounds on social media for its adorable, bear-like appearance – is a famously hardly organism and is the first animal known to survive in space. Be it extreme heat, heavy radiation, high pressures and even desiccation, the “water bear” can shrug it off.
From The New York Times:
They can remain like that in a dry state for years, even decades, and when you put them back in water, they revive within hours,” said Thomas Boothby, a postdoctoral researcher from University of North Carolina at Chapel Hill. “They are running around again, they are eating, they are reproducing like nothing happened.”
To determine what allowed tardigrades to survive this kind of extreme dryness, Dr. Boothby and his colleagues designed a test in which the microscopic animals were put into a humidity chamber and slowly dried out as in an evaporating pond– the tardigrade’s native habitat. They discovered that the tardigrades have special genes that create glass-like proteins that can preserve their cells during desiccation.
“The glass is coating the molecules inside of the tardigrade cells, keeping them intact,” said Dr. Boothby said. This slows down the tardigrade’s metabolism, allowing it to remain in a suspended state until it is rehydrated. When they add water, the proteins melt into the liquid, and the molecules within the tardigrade are free to carry out their functions again.
