1. Researchers are now applying distributed acoustic sensing, which uses internal flaws in a long optical fiber as seismic sensors, to monitor seismo-acoustic signals produced actions such as the formation, break-up, thickness fluctuations, and movement of sea ice. Already, they’ve been able to track the spread of sea ice across almost 25 miles of the Beaufort Sea north of Alaska, and in near-real time.
The distributed acoustic sensing signals helped the researchers observe changes along that stretch of water, from an open-water state to that which is ice-bound. Open-water signals are much noisier than ice-bound ones, causing disruptive hydroacoustic noise such as wind waves. The ice sheets on top isolate that noise and generate what researchers call exotic floating-plate wave modes that are more easily detected with distributed acoustic sensing.
This ability to monitor sea ice formation and movement in near-real time should help scientists better understand the overall health of the Arctic region, and perhaps someday help alleviate effects of climate change.
2. Researchers have expanded on a common noninvasive treatment—in which a balloon or other implant is inserted into the stomach—that’s meant to suppress appetite. They began with development of a new type of implant—an intra-gastric, satiety-inducing implantable device, which they later coated with methylene blue, a thiazine dye. This was then tested on pigs.
When exposed to laser light, the dye released an energized form of oxygen that effectively killed cells that produce ghrelin in the stomach and then quickly disappeared. Commonly referred to as the hunger hormone, ghrelin stimulates appetite, increases food intake, and promotes the storage of fat.
After about a week, the researchers documented reduced weight gain and ghrelin levels in the tested pigs, compared to those that did not have the procedure. The team expects that with further development, the procedure could be used in humans.
3. Researchers in Germany are exploring uncharted territory thanks to a drone they’ve developed that’s smaller than a red blood cell. They have shown it’s possible to propel micron-sized objects—in this case, microdrones—into an aqueous environment including veins in the body, using only light. And not only have they gotten the technology into such spaces, they can even control it precisely on a surface with all degrees of freedom.
Modeled after standard quadcopter drones, which feature four independent rotors for complete control of its movements, the new microdrone is comprised of a transparent polymer disc measuring 2.5 µm in diameter, with up to four independently movable gold nanomotors based on optical antennas embedded within it.
The researchers say the microdrones have strong potential for use in reproductive medicine or more in-depth analysis of nanometer-sized structures and surfaces.
