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Scientists Develop Quick, Inexpensive Paper Blood Type Test

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Natural disasters and other emergencies often result in the need for blood transfusions. But they also can result in a loss of electricity, which can make it impossible to perform the tests required to determine a patient’s blood type. Now researchers in China may have an alternative: a cheap, rapid blood type test made of color-changing paper. They reported their progress in the journal Science Translational Medicine.

Each of the eight blood types has its own antigens and antibodies (either type A or type B), which help the immune system defend against unwelcome interlopers. Injecting a patient with incompatible antigens and antibodies causes the immune system to attack, making a person much sicker.

The researchers’ new blood type test works by identifying which antibodies and antigens trigger this immune attack. They mixed dye into two solutions, one containing antibody A and one containing antibody B, and printed small squares of the dye mixture onto either end of a long strip of paper.

Zhang et al. 2017. Science Translational Medicine.

 
To test a patient’s blood, they squeezed a few drops into the center reservoir. That blood then seeped through the paper, spreading toward the antigens at either end. Different blood types react differently to the antigens, causing the dye to turn either teal or brown. The entire process takes less than two minutes.

The researchers used both their new paper test and the current time- and electricity-intensive method to test 3550 different samples. The little piece of paper was astonishingly on-point, reaching the same conclusions as the electronic test 99.9 percent of the time.

More experiments are needed before the paper test will be ready for prime time, but it’s a very promising start. Along with recently developed paper microscopes and paper centrifuges, this cheap test could do a world of good in the places that need it the most.

[h/t Popular Science]

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Animals
Owning a Dog May Add Years to Your Life, Study Shows
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We've said that having a furry friend can reduce depression, promote better sleep, and encourage more exercise. Now, research has indicated that caring for a canine might actually extend your lifespan.

Previous studies have shown that dog owners have an innate sense of comfort and increased well-being. A new paper published in Scientific Reports and conducted by Uppsala University in Sweden looked at the health records of 3.4 million of the country's residents. These records typically include personal data like marital status and whether the individual owns a pet. Researchers got additional insight from a national dog registry providing ownership information. According to the study, those with a dog for a housemate were less likely to die from cardiovascular disease or any other cause during the study's 12-year duration.

The study included adults 40 to 80 years old, with a mean age of 57. Researchers found that dogs were a positive predictor in health, particularly among singles. Those who had one were 33 percent less likely to die early than those who did not. Authors didn't conclude the exact reason behind the correlation: It could be active people are more likely to own dogs, that dogs promoted more activity, or that psychological factors like lowered incidences of depression might bolster overall well-being. Either way, having a pooch in your life could mean living a longer one.

[h/t Bloomberg]

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Live Smarter
Not Sure About Your Tap Water? Here's How to Test for Contaminants
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In the wake of Flint, Michigan's water crisis, you may have begun to wonder: Is my tap water safe? How would I know? To put your mind at ease—or just to satisfy your scientific curiosity—you can find out exactly what's in your municipal water pretty easily, as Popular Science reports. Depending on where you live, it might even be free.

A new water quality test called Tap Score, launched on Kickstarter in June 2017, helps you test for the most common household water contaminants for $120 per kit. You just need to take a few samples, mail them to the lab, and you'll get the results back in 10 days, telling you about lead levels, copper and cadmium content, arsenic, and other common hazardous materials that can make their way into water via pipes or wells. If you're mostly worried about lead, you can get a $40 test that only tells you about the lead and copper content of your water.

In New York State, a free lead-testing program will send you a test kit on request that allows you to send off samples of your water to a state-certified lab for processing, no purchase required. A few weeks later, you'll get a letter with the results, telling you what kind of lead levels were found in your water. This option is great if you live in New York, but if your state doesn't offer free testing (or only offers it to specific locations, like schools), there are other budget-friendly ways to test, too.

While mailing samples of your water off to a certified lab is the most accurate way to test your water, you can do it entirely at home with inexpensive strip tests that will only set you back $10 to $15. These tests aren't as sensitive as lab versions, and they don't test for as many contaminants, but they can tell you roughly whether you should be concerned about high levels of toxic metals like lead. The strip tests will only give you positive or negative readings, though, whereas the EPA and other official agencies test for the concentration of contaminants (the parts-per-billion) to determine the safety of a water source. If you're truly concerned with what's in your water, you should probably stick to sending your samples off to a professional, since you'll get a more detailed report of the results from a lab than from a colored strip.

In the future, there will likely be an even quicker way to test for lead and other metals—one that hooks up to your smartphone. Gitanjali Rao, an 11-year-old from Colorado, won the 2017 Young Scientist Challenge by inventing Tethys, a faster lead-testing device than what's currently on the market. With Tethys, instead of waiting for a lab, you can get results instantly. It's not commercially available yet, though, so for now, we'll have to stick with mail-away options.

[h/t Popular Science]

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