General Knowledge Quiz – 18 (KSP : Knowledge Se Pehchan)

Scientists at Princeton and Tufts are working on a superthin tooth sensor (a kind of temporary tattoo) that sends an alert when it detects bacteria associated with plaque buildup, cavities or infection. It could also notify your dentist, adding an extra layer of social pressure to make an appointment. The sensor may have wide-ranging use: the researchers have already used it to identify bacteria in saliva associated with stomach ulcers and cancers. While the sensor won’t last long on the surface of a well-brushed and flossed tooth, Michael McAlpine, the project’s leader, says that the sensors will be inexpensive enough that you can replace them daily.Clay Risen

Wearing a small sensor on your head, at home, while you sleep, could be the key to diagnosing diseases early and assessing overall health. “This tech,” says Dr. Philip Low, the founder of a medical technology firm called NeuroVigil, “enables us to look for faint signals of, say, schizophrenia, Parkinson’s, depression or Alzheimer’s in the brain, even though there may be no obvious symptoms.” Thus far, Low’s device has found a number of applications: evaluating children with autism, studying the efficacy of trial-phase drugs and assessing traumatic brain injury in soldiers. Currently, Low is working on a newer version of the device, which will be the size of a quarter and will transmit brain scans directly to smartphones and tablet computers. “We’re using sleep,” Low says, “as the gateway to the brain.” Howie Kahn

This year, Eva Redei, a professor at Northwestern’s Feinberg School of Medicine, published a paper that identified molecules in the blood that correlated to major depression in a small group of teenagers. Ridge Diagnostics has also started to roll out a test analyzing 10 biomarkers linked to depression in adults. “Part of the reason there’s a stigma for mental illness, including depression, is that people think it’s only in their heads,” Redei says. “As long as there’s no measurable, objective sign, we’re going to stay in that mind-set of ‘Just snap out of it.’ ” Blood tests will take mental illness out of the squishy realm of feelings. And as Lonna Williams, C.E.O. of Ridge Diagnostics, says, they’ll help people understand “it’s not their fault.” Elizabeth Weil

Researchers at the Wyss Institute for Biologically Inspired Engineering at Harvard are working on a technology that would make household cleaning supplies much smarter — almost like a sprayable forensics team. When the spray hits a surface where there are pathogens present, like your bathroom sink, it would bind to the bad stuff and turn a color — orange, say, for E. coli. Then you could knock it out with a stronger disinfectant. Nathaniel Penn