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a variety of other pyrotechnics ingredients. But the combustion of these mixtures produces a variety of polychlorinated aromatic chemicals, including some potent carcinogens. To make more environmentally friendly fireworks, the researchers focused on strontium monohydroxide, a compound long believed to be only a minor contributor to the red color of pyrotechnics. According to Koch, for years, scientists hadn’t realized that strontium monohydroxide also strongly flared red because its sister product, strontium oxide, produces an orange-red color that fireworks-makers try to avoid. Sabatini, Koch, and coworkers formulated the new explosive by replacing polyvinyl chloride on the old ingredient list with either hexamine, a preservative in citrus washing solutions, or 5-amino-1H-tetrazole, an air-bag propellant. The replacement sidesteps chlorine and produces strontium monohydroxide when the overall concoction is ignited, resulting in bright red fireworks. The potential benefit is not just to those putting on Fourth of July and New Year’s Eve fireworks displays, comments David E. Chavez, a chemist at Los Alamos National Laboratory. The military is also a large consumer of red flares, particularly for training purposes. “Training areas get fallout [from flares] over and over again,” he says. So much so “that it can be an issue for environmental clean-up,” Chavez adds.—SARAH EVERTS
SCI . ADV.
RED FIREWORKS GO GREEN
who led the research team along with lung transplant specialist Shaf Keshavjee and graduate researcher Andrew T. Sage at the University of Toronto. This rapid testing relies on synthetic chains of nucleic acids, which are attached to spiky gold electrodes on glass chips. The team chose a set of these synthetic probes that selectively bind to three messenger RNA molecules associated with primary graft dysfunction. Researchers don’t fully understand how this trio contributes to the disorder, but two are tied to tissue inflammation, Kelley says. When a probe molecule binds to its partner mRNA molecule, the gold electrodes record an electron flux that signals the interaction, enabling the researchers to quantify the biomarkers present in the donor tissue. By sampling 52 human donor lungs selected for transplantation, the team demonstrated that their sensors could predict primary graft dysfunction. Such devices could help get lungs to more patients who need them, says Jason D. Christie, director of the Center for Translational Lung Biology at the University of Pennsylvania. “A lot of people die on the lung transplant wait list,” Christie says. Surgeons lack rapid, reliable, quantitative tools to analyze donor lungs and won’t transplant organs that appear suspect, he says. But many of these organs are actually suitable transplants. Kelley hopes her team’s research will help rescue serviceable lungs. “This is exciting,” she says. “It’s been fascinating to see how new sensor chemistry can create a solution to this problem.”—MATT DAVENPORT
ENVIRONMENTAL SCIENCE: Ditching
chlorine-based ingredients avoids production of carcinogenic chemicals
M Current fireworks get their red hue primarily from strontium monochloride, which can generate cancer-causing fallout.
AKERS OF FIREWORKS AND FLARES have
long believed that the beautiful red color in their explosions could be attained only with chlorine-based compounds. But after these ingredients combust, they can transform into cancer-causing chemicals that then fall to the ground. Now, new chlorine-free pyrotechnics could pave the way for a generation of red fireworks and flares that are better for the environment and for people’s health, says Jesse J. Sabatini at the U.S. Army Research Laboratory, in Maryland. Sabatini developed the red pyrotechnics with Ernst-Christian Koch at consulting firm Lutradyn, in Kaiserslautern, Germany (Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201505829). Currently, red fireworks get their hue primarily from strontium monochloride, which is produced by burning strontium compounds with polyvinyl chloride and
RAPID SCREENING FOR SAFER LUNG TRANSPLANTS BIOSENSORS: Devices test organs for
signs of dysfunction before implant
I An electrode’s spiky structure enhances its ability to snag biomarkers of lung dysfunction from a sample solution. Scale bar is 3 μm.
N THE DAYS following a lung transplant, a condition
known as primary graft dysfunction can prevent the organ from properly taking in and circulating oxygen. The disorder afflicts 10 to 25% of patients, studies estimate. It proves lethal nearly half the time. Researchers have now developed sensors that rapidly screen donor lungs for molecular warning signs of this disorder before the organs reach patients (Sci. Adv. 2015, DOI: 10.1126/sciadv.1500417). Although surgeons already have methods to examine donor lungs for biomarkers linked to primary graft dysfunction, these techniques require several hours to report results—more time than transplant surgeons typically have. The new sensors can provide results in less than 20 minutes, says Shana O. Kelley, CEN.ACS.ORG
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