Many DNA nanostructures have been constructed by scientists for many different kinds of applications, such as drug delivery, medical diagnosis, and DNA-based computers. But in order to be successful in designing these nanostructures, we must first find out what exactly the 3D structure of DNA looks like!
But how can we look at the structure DNA helix? It's so small! Well, scientists have built powerful microscopes to try and visualize DNA. Atomic force microscopy (AFM) is a powerful technique but does not visualize in 3D very well. Another powerful tool that has been built is called the electron cryomicroscopy (cryoEM).
CryoEM can be used to look at the structure of a 7 nm self-assembled DNA tetrahedron, which is an incredible achievenment for scientists. Never before has such a small biological molecule been looked at with such high resolution!
Source: Nano Letters
Lookin' at DNA Nanostructures
The Creepy Crawling Nano-Fiber Vacuum
Tired of mopping and sweeping your floors? Now cleaning has become so much easier!
Let this new crawling vacuum introduced by Panasonic do all the dirty work! It's called Fukitorimushi, which means "Wipe-up Bug" in japanese. Working with textile maker Teijin, they have developed an autonomous floor-cleaning robot that crawls around like an inchworm. The robot is covered in a super-absorbent polyester nanofiber cloth that picks up microscopic dust and residue that ordinary vacuums leave behind.
The specially designed nanofibers significantly increase the fabric's surface area and porosity, giving it super wiping characteristics and the ability to absorb oil and ultra-fine dust particles less than one micrometer in diameter. How small is a micrometer? Well, to give you an idea, a single human hair is approximately 100 micrometers in diameter. So it's really small! The large surface contact area also increases the fabric's friction with the floor, allowing it to use this friction to push itself forward while wiping the floor. Check out the cool video!
Playing Pinball with Atoms
Many of you may have played pinball in an arcade before. How small is that pinball be? The size of a marble? The size of an ant? What if you could play pinball with something much much smaller? What's the smallest thing you can think of?
Researchers in the Netherlands have developed an atomic scale mechanical device by using electrical current to make two atom pairs behave like the flippers on a atomic-sized pinball machine.
On a piece of germanium, platinum atoms heated under a very high vacuum, which causes them to form dimer chains. Platinum dimers are structures that consist of two platinum atoms linked together. When electrons are injected into the platinum dimers using a scanning tunneling microscope tip, the atom pairs can switch to as many as six different configurations!
Source: ACS Publications
Nano Tattoo for Diabetics
For many, tattoos allow people to express their style. But did you know that in the near future, tattoos may become a means of treating disease? Diabetics who monitor their blood sugar levels often have endure many needle pricks every day. However, Heather Clark of Draper Laboratory in Massachusetts is developing a new tattoo ink that changes color based on glucose levels inside the skin.
So how does it work? The dye is made up of tiny plastic nanoparticles. When the glucose is low, the particle is yellow and fluorescent, but when glucose levels increase, the fluorescence goes away and the particles turn purple. Though this tattoo would have to be periodically re-injected because it would shed along with the skin, it's a major step up from the daily needle pricks!
Scientists hope that this technology will be up and running in the next five to ten years.
Source: Earth and Sky
My head is in the clouds...
... and what do I see? Bacteria! Pollen! Fungi! What's going on? A team of atmospheric chemists at University of California at San Diego have performed the first-ever direct detections of biological particles inside ice clouds. Taking samples of water droplets and ice crystal residues using a mass spectrometer while flying at high speeds through clouds in the skies of Wyoming, these researchers have revealed that the growth ice crystals were initiated almost entirely of dust or biological material, such as bacteria, fungal spores, and plant material.
Though it has long been known that microorganisms become airborne and travel great distances, this is the first study that analyzes their influence on cloud formation. Researchers have found that the ice crystal residues were half made up of mineral dust and a third were made up of inorganic ions mixed with nitrogen, phosphorus, and carbon - the signature elements of biological matter.
If we can understand how these particles cause cloud formation, we can then determine the impact they have on the climate. For example, some scientists believe that the dust transported from Asia could be impacting the rainfall in North America!
Source: NSF Press Release 09-100
The Physics of Pizza Tossing
Interested in learning the art of a perfect pizza toss? Well, so are Monash University scientists who are studying the pizza toss in order to design the next generation of micro motors thinner than a single human hair. How does the dough travel through the air? How much does the dough rotate? How quickly does it spin?
The Monash's team of scientists are modeling the pizza toss mathematically, and have found that tossing pizza dough continuously without stopping to catch it requires your hands to move in circles. This model could help researchers design better ultrasonic motors, which operate on similar principles as pizza tossing. In the future, these tiny motors could be used in minimally invasive neuro-microsurgery procedures, giving surgeons more control and precision during brain surgery.
Source: EurekAlert!
Image Source: Seattlepi.com
Harnessing the Power of Viruses
Researchers at MIT have genetically engineered viruses to build the positively and negatively charged ends of a lithium ion battery. With the same energy capacity and power performance as state-of-the-art rechargeable batteries, they could be used to power plug-in hybrid cars and a range of personal electronics.
For the cathode, these genetically engineered viruses are built to coat themselves with iron phosphate, then self-assemble onto carbon nanotbues to create a network of highly conductive material. These viruses are a common bacteriophage, which infect bacteria but art harmless to humans.
Part of a recent wave of clean-energy technologies, these battery prototypes are lightweight, flexible, and pending commercial production.
Source: Eurekaalert
Who dunnit?
One of the most important clues at a crime scene investigation are latent fingerprints left behind by the criminal. No two fingerprints are alike - every individual has unique fingerprint ridges that do not change throughout one's lifetime. Over the years, forensic scientists have developed many ways to look at these fingerprints. Today, the most commonly used method is still fingerprint dusting where powder is spread lightly over a fingerprint surface using a brush, and clear tape is placed over the latent print in order to transfer and preserve the fingerprint pattern.
Scientists have developed special polymer films to improve the transfer of the fingerprint from the crime scene surfaces to the laboratory. This new polymer is conjugated with highly fluorescent particles so that interaction with oil would cause swelling and increased fluoresence intensity. This allows fingerprints to show up more clearly. Below are two fluorescent images showing (a) a fingerprint transferred to a polymer film from a glass surface and (b) the same fingerprint image after digital contrast enhancement.
Source: Chemical Communications
Image Sources: Teachcops Chemical Communications
