Atom-Scale Magnetic Field Sensors First Step Toward Direct Imaging of Molecules
Physicists in the U.S. and Germany report important steps toward magnetic resonance imaging, or MRI, of molecules in two separate studies. In both reports, the researchers show how specially modified diamond flakes can be used as nanoscale magnetic field detectors. These tiny sensors can elucidate the structure of single organic molecules.
With nanoscale MRI, researchers may one day be able to directly image proteins and other molecules at the atomic scale.
DARPA Can Spot a CD from 20,000 Feet, Monitor the Entire Island of Manhattan with Two Drones
DARPA and the US Army have taken the wraps off ARGUS-IS, a 1.8-gigapixel video surveillance platform that can resolve details as small as six inches from an altitude of 20,000 feet (6km).
ARGUS is by far the highest-resolution surveillance platform in the world, and probably the highest-resolution camera in the world, period. ARGUS, which would be attached to some kind of unmanned UAV (such as the Predator) and flown at an altitude of around 20,000 feet, can observe an area of 25 square kilometers (10sqmi) at any one time.
If ARGUS was hovering over New York City, it could observe half of Manhattan. Two ARGUS-equipped drones, and the US could keep an eye on the entirety of Manhattan, 24/7. It is the definition of “observe” in this case that will blow your mind, though.
With an imaging unit that totals 1.8 billion pixels, ARGUS captures video (12 fps) that is detailed enough to pick out birds flying through the sky, or a lost toddler wandering around. These 1.8 gigapixels are provided via 368 smaller sensors, which DARPA/BAE says are just 5-megapixel smartphone camera sensors. These 368 sensors are focused on the ground via four image-stabilized telescopic lenses.
In The Worlds First Actual Photo of DNA You Can See the Helixes
The image was taken by Enzo di Fabrizio from the University of Genoa, Italy. He choreographed the scene by pulling a small strand of DNA from a diluted solution and then propping it up like a clothesline between two nanoscopic silicon pillars.
The trick to the technique was in acquiring a discrete strand of DNA that could be stretched out and ready to view with an electron microscope. Di Fabrizio managed this by creating a pattern of pillars that repelled water — which resulted in quick moisture evaporation and a residual strand of DNA all ready to go.
Then, in order to create a high-resolution image, di Fabrizio drilled tiny holes in the base of the nanopillar bed and shone beams of electrons.
Aside from creating a cool image, the technique will allow the researchers to investigate DNA in greater detail, as well as seeing how it interacts with proteins and RNA.
(via Scientists snap a picture of DNA’s double helix for the very first time)
Researchers Use New Imaging Technique to Find Previously Undiscovered Waste-Disposal System in the Brain
Pressurized “Hydraulic System” flushes active brain with Cerebro-Spinal Fluid
Nedergaard’s team has dubbed the new system “the glymphatic system,” since it acts much like the lymphatic system but is managed by brain cells known as glial cells.
…Scientists have known that cerebrospinal fluid or CSF plays an important role cleansing brain tissue, carrying away waste products and carrying nutrients to brain tissue through a process known as diffusion.
The newly discovered system circulates CSF to every corner of the brain much more efficiently, through what scientists call bulk flow or convection.
…“Given the high rate of metabolism in the brain, and its exquisite sensitivity, it’s not surprising that its mechanisms to rid itself of waste are more specialized and extensive than previously realized.”
While the previously discovered system works more like a trickle, percolating CSF through brain tissue, the new system is under pressure, pushing large volumes of CSF through the brain each day to carry waste away more forcefully. The glymphatic system is like a layer of piping that surrounds the brain’s existing blood vessels.
…The team found that CSF is pumped into the brain along the channels that surround arteries, then washes through brain tissue before collecting in channels around veins and draining from the brain.
How has this system eluded the notice of scientists up to now? The scientists say the system operates only when it’s intact and operating in the living brain, making it very difficult to study for earlier scientists who could not directly visualize CSF flow in a live animal, and often had to study sections of brain tissue that had already died.
To study the living, whole brain, the team used a technology known as two-photon microscopy, which allows scientists to look at the flow of blood, CSF and other substances in the brain of a living animal.
…“It’s a hydraulic system,” said Nedergaard. “Once you open it, you break the connections, and it cannot be studied. We are lucky enough to have technology now that allows us to study the system intact, to see it in operation.”
(via Scientists discover previously unknown cleansing system in brain | KurzweilAI)
Disney Creates 3D Scanning Process to Improve Animatronic Heads
The process starts by scanning 3D facial expressions from a human subject. Then, a novel optimization scheme determines the shape of the synthetic skin as well as control parameters for the robotic head that provide the best match to the human subject.
This processing increases the realism of the resulting character, resulting in an animatronic face that closely resembles the human subject. “With our method, we can simply create a robotic clone of a real person,” said Dr. Bernd Bickel, researcher at Disney Research, Zürich.
“The custom digitally designed skin can be fabricated using injection molding and modern rapid prototyping technology. We 3D print a mold and use elastic silicon with properties similar to human skin as base material… Physical face cloning enables us to create personalized animatronic figures based on real individuals with a level of fidelity and realism never before possible.”
(via Disney researchers develop new automated process for cloning human faces | KurzweilAI)
Nano-Material Inspired by Moth’s Eyes Enables Medical Imaging With Less Radiation
If you want a detector to pick up more light, the technique has usually been to increase the intensity of the X-rays. But this obviously has associated health risks.
Yi and his team believed that if they could improve the scintillation material so that it reemitted more light from the same amount of X-rays, then they could create safer medical imaging devices. To do this, the researchers needed to create a new class of materials.
What they came up with is based on a thin film made from cerium-doped lutetium oxyorthosilicate crystals. They were then able to cover these crystals with pyramid-shaped bumps made of silicon nitride. It is these bumps that make the scintillator appear like the moth’s eye and give the structures its ability to extract more light.
The results have been pretty dramatic. Yi and his team measure that adding their moth-eye-inspired thin film to the scintillator of an X-ray mammographic unit increases the amount of reemitted light by 175 percent.
“The moth eye has been considered one of the most exciting bio structures because of its unique nano-optical properties,” Yi says in Nanomagazine article. “Our work further improved upon this fascinating structure and demonstrated its use in medical imaging materials, where it promises to achieve lower patient radiation doses, higher-resolution imaging of human organs, and even smaller-scale medical imaging. And because the film is on the scintillator,” he adds, “the patient would not be aware of it at all.”
(via Nanostructures Modeled on the Moth Eye Reduce Radiation in Medical Imaging - IEEE Spectrum)
Photograph Of the Shadow Cast By a Single Atom of Ytterbium
It took Australian researchers five years to come up with a way to get the photo. In the end they used an atom of Ytterbium, cooled to just a few thousands of a degree above absolute zero, in an ion trap.
On a conceptual level, this is obviously totally cool, but there are a bunch of practical things associated with this research too. For example, using shadows to measure the locations of atoms and molecules is much less damaging and invasive than other imaging techniques, and it could be a way to track the behavior of biological samples (like DNA) without shredding them like X-rays and UV rays do.
(Via This is the shadow cast by a single atom ht 8bitfuture)
Surgeons Using Kinect to Review Diagnostic Imaging in Real-Time in the OR
On Tuesday last week, a surgeon at Guy’s and St Thomas’ hospital in London began trials of a new device that uses an Xbox Kinect camera to sense body position. Just by waving his arms the surgeon can consult and sift through medical images, such as CT scans or real-time X-rays, while in the middle of an operation.
Maintaining a sterile environment in the operating room is paramount, but scrubbing in and out to scroll through scan images mid-operation can be time-consuming and break a surgeon’s concentration or sense of flow. Depending on the type of surgery, a surgeon will stop and consult medical images anywhere from once an hour to every few minutes.
To avoid leaving the table, many surgeons rely on assistants to manipulate the computer for them, a distracting and sometimes frustrating process.
“Up until now, I’d been calling out across the room to one of our technical assistants, asking them to manipulate the image, rotate one way, rotate the other, pan up, pan down, zoom in, zoom out,” says Tom Carrell, a consultant vascular surgeon at Guy’s and St Thomas’, who led the operation on 8 May to repair an aneurism in a patient’s aorta. With the Kinect, he says, “I had very intuitive control”.
(via Kinect imaging lets surgeons keep their focus - tech - 17 May 2012 - New Scientist)
New Imaging Technique Makes 3-D Models of Individual Proteins:
Proteins are like the workhorses of genetic biology, but they can be notoriously difficult to study. Their structure has everything to do with their function—and sometimes dysfunction—which has far-reaching implications in health and medicine. That’s why it’s such a big deal that a couple of researchers at Lawrence Berkeley National Laboratory have more or less hacked their cryo-electron microscope to see at far greater resolutions than its manufacturer intended and produced the first 3-D images of an individual protein with enough clarity to determine its structure.
Cataloging the shapes and structures of proteins is fairly routine science at this point. Pharmaceutical companies dealing in biologic drugs do so all the time as they search for protein therapies that might relieve one condition or another. But it’s not easy, and these conventional protein models are averages of the analyses of many thousands of molecules because it’s simply too difficult to get the resolutions necessary to image the features of an individual protein.
Until now. Gang Ren and Lei Zhang are reporting in the journal PLoS One the creation of their own brand of electron microscopy that they are calling “individual-particle electron tomography,” or IPET. Their images are still a bit fuzzy, but they are good enough for researchers to define a protein’s structure. Moreover, by creating a novel method of keeping their samples extremely cold (flash-frozen-in-liquid-nitrogen-to-negative-292-degrees cold) and tilting them up to 140 degrees while under the lens, they can generate more than a hundred images in a matter of a couple of hours.
Once stitched together those images inform each other, creating not only 3-D depth but helping to focus in on the subject protein and remove noise from the imagery. The result is the best structural imagery of an individual protein that we’ve ever heard about, one with the potential to go far in pharmaceutical research and in informing our fundamental understanding of protein dynamics.
Electron Holography Produces First Image Of A Single Protein
What’s needed, of course, is a way of imaging individual proteins. One idea is to us x-rays or electron beams to do the trick and indeed some groups have had some success with this technique. But the disadvantage is that beams with an energy of a few KeV tend to destroy biomolecules so it’s not clear how accurate these images can be. Nether is it possible to view the molecules over time.
Today, Jean Nicholas Longchamp and pals at the University of Zurich in Switzerland have found a way round this. These guys make the entirely sensible suggestion of imaging proteins using low energy electron beams that don’t destroy biomolecules.
At this energy, electron beams have a wavelength of a nanometre or so, making them perfect not just for imaging with atomic resolution, but for holography.
And that’s exactly what these guys have done. They’ve created an electron hologram of a protein molecule called ferritin—that’s the football-shaped protein that stores and releases iron and is found in almost all living things.
(via unexpectedtech)
