Science Briefs: 3-D printers a boon to scientists’ labs

3-D printed parts provide the stands for the aluminum globes in PPPL’s Planeterrella, a device that simulates Northern Lights.
3-D printed parts provide the stands for the aluminum globes in PPPL’s Planeterrella, a device that simulates Northern Lights. Princeton Plasma Physics Laboratory

With a series of experiments, researchers at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory found 3-D printers have become a very important tool.

“The printer is now a crucial piece of our laboratory and used regularly,” said Andrew Zwicker of PPPL and lead author of a paper that reports the results in the current issue of the American Journal of Physics.

Researchers have become interested because the printers can build customized parts for experiments, often at very low cost. And because a 3-D printer can produce parts quickly, the time between when a need is recognized and when a part is ready to be installed can be just a few hours.

Body’s salt accumulates, goes to work at skin infections

Researchers at Vanderbilt University and in Germany have found that sodium accumulates in the skin and tissue in humans and mice to help control infection.

In a report published online by the journal Cell Metabolism, researchers conclude that salt stores may be nature’s way of providing a barrier to microbial invasion and boosting immune defenses.

The study began with the observation that salt levels in mice with infected skin were surprisingly high. Jonathan Jantsch, a microbiologist at Erlangen and Regensburg universities in Germany and the paper’s first author, suggested that skin might use salt accumulation to ward off infections.

Indeed, the researchers found that salt increased the activation of infection-fighting macrophages, a type of white blood cell.

Using an MRI technique they developed, they also found that salt accumulated at the site of bacterial skin infections in six patients. “The infected legs showed massive salt accumulation, while the uninfected legs were totally normal,” said senior author Jens Titze of Vanderbilt.

The salt accumulation in the infected legs disappeared when the patients were treated with antibiotics.

The researchers also tested the effect of an extremely high-salt diet in mice with persistent footpad infections. Salt stores at the site of the infection increased after consumption of the high-salt diet, and the infections cleared up.

Duke study calculates social cost of fuels

When the environmental and human health toll is factored in, a gallon of gasoline costs us about $3.80 more than the pump price, a new Duke University study finds.

The social cost of a gallon of diesel is about $4.80 more than the pump price; the price of natural gas more than doubles; and coal-fired electricity more than quadruples. Solar and wind power, on the other hand, become cheaper than they initially seem.

“We think we know what the prices of fossil fuels are, but their impacts on climate and human health are much larger than previously realized,” said Drew Shindell, professor of climate sciences at Duke’s Nicholas School of the Environment. “We’re making decisions based on misleading costs.”

Shindell’s study was published Feb. 26 in the peer-reviewed journal Climatic Change.

Current markets don’t place a price on most atmospheric emissions, so polluters typically pay none of those costs, he noted. Instead, society picks up the tab through increased risks of premature death or illness caused by air pollution, higher health care costs, lower crop yields, missed work and school days, increased insurance damages from floods and other extreme weather events linked to climate change and other social costs.

The comparative framework devised by Shindell to calculate these costs is built upon a widely used methodology introduced in 2010 to help the U.S. government determine the social costs of carbon.