Microscope on a Dime
A lensless microscope the size of a dime might quickly and cheaply scan blood for tumor cells and parasites. In the device created by Changhuei Yang and his team at the California Institute of Technology, light shines on a liquid sample flowing through a narrow channel, below which are one-micron-wide apertures spaced 10 microns apart. The light shines through the holes onto a semiconductor chip studded with sensor pixels similar to those in digital cameras. Objects that float over the apertures block some of the incoming light received by the pixels, which construct an image of the object based on the variations in light intensity. Details down to 0.8 to 0.9 micron are apparent. (Cancer cells typically measure 15 to 30 microns.) With a chip-based microscope, “there’s no lens to break,” says Yang, who was inspired by “floaters,” the clumps of dead cells and other debris in the eye. Better yet, they cost about $10 a pop.
PLURIPOTENT CELLS MOTOR ON
Researchers have used genes to make adult cells pluripotent, that is, capable of giving rise to any cell type. But whether the reprogrammed cells could then generate specific cells needed to treat a disease was uncertain. Scientists at Harvard University and their colleagues have succeeded in making pluripotent the skin cells from an elderly patient with Lou Gehrig’s disease (amyotrophic lateral sclerosis). Exposed to the right molecules, the induced pluripotent stem cells turned into motor neurons, which the ailment normally destroys. Science published the finding online July 31.
ANCHORS AWAY FOR REEFS
A new study confirms that coral reefs will face tough conditions from rising greenhouse gas levels. The reason: marine cements that bind together and anchor reefs cannot form in water full of dissolved carbon dioxide (CO2). Researchers report in the July 29 Proceedings of the National Academy of Sciences USA that naturally acidic water in the Pacific Ocean off Central America keeps local reefs soft—a preview of how coral reefs may fare worldwide as atmospheric CO2 levels rise.
A drug might someday turn you into a long-running machine without a day of exercise. It might work, in essence, by reprogramming sugar-burning, fast-twitch muscle into fat-burning, slow-twitch muscle that does not tire as easily. The key to this transformation is a protein called PPAR-delta, which had been shown to create so-called high-endurance marathon mice if the animals were genetically engineered to make a lot of it. Besides supercharging stamina, the drug, called AICAR, might also treat muscular dystrophy as well as metabolic diseases such as diabetes, because it appears to help the body use and remove glucose from the blood more effectively.
Note: The article was originally published with the title, "In Brief".