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The nerve gas sarin was released on several subway lines in Tokyo in 1995 in a terrorist attack. Thirteen people died, and many more had severe injuries. But while such an incident is going on, how do you determine what’s happening and what might be in the air?

 

SensorCrop.jpgSomeday, first responders might come onto the scene and, after evacuating everyone, release a bunch of beetles with tiny, thin sensors on them into the subway stations. As the beetles make their way into the stations, the sensors would wirelessly report back whether sarin gas or some other agent is present.

 

That’s what Jang-Ung Park and colleagues envision. They are developing futuristic thin, flexible electronic devices that could attach onto leaves, insects, clothes or human skin to monitor environmental conditions or even someone’s health status.

 

The researchers, who are at the Ulsan National Institute of Science and Technology and Korea Electrotechnology Research Institute, report in ACS’ journal Nano Letters that they’ve come up with a simple, inexpensive way to make the sensors.

 

They are using carbon-based materials — graphite and carbon nanotubes — instead of silicon, which is traditionally used to make electronic circuits.

 

“The fabrication and processing can be much cheaper with our sensors because the entire device can be chemically synthesized in a single step, and carbon is also much less expensive than silicon,” says Park.

 

Sensor2.jpgSilicon-based electronics are brittle and rigid, but the carbon-based sensors that Park’s team is making are flexible. The sensors can even bend around a thin optical fiber without breaking. They also can stick to living things, like skin, bugs and plants, without adding an adhesive.

 

They tested their sensors by putting them onto the leaf of a “lucky bamboo” plant and onto the backs of “stag beetles.” The sensors performed well, detecting DMMP, which is similar to sarin, within seconds. 

 

The authors acknowledge funding from the Basic Science Research Program of the National Research Foundation of Korea, IT R&D Program, Materials Original Technology Program and Technology Innovation Program.

 

 

What do you think? Is this feasible? What other applications can you think of for these sensors, aside from detecting harmful gases?

 

 

“In-situ Synthesis of Carbon Nanotube–Graphite Electronic Devices and Their Integrations onto Surfaces of Live Plants and Insects”

 

Click here for the abstract.

 

*Journalists can request a PDF of the journal article by emailing newsroom@acs.org.

 

Credit for both images: American Chemical Society

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For a strawberry-lover there’s nothing better than picking that sweet, dark red piece of fruit right off the bush and popping it into your mouth. Well, maybe strawberries and cream would be nice, too. And then there’s strawberry jam slathered on a nice piece of buttered toast. Wait: How about a big slice of strawberry pie? 

Just when you think it can’t get any better for your strawberry desserts, there’s new, exciting research on your favorite fruit. Scientists are breeding the better berry. So far these super-good strawberries appear to have more healthful antioxidants and a sweeter flavor than your standard red berry of the same name in grocery stores. Another advantage of their process is that it involves natural breeding to develop new varieties and does not produce “genetically modified,” or GMO, strawberries, avoiding this controversial technique.


According to a report in the ACS’ Journal of Agricultural and Food Chemistry, strawberries are an excellent source of vitamins, minerals, dietary fiber and flavonoids, a rich source of antioxidants. Numerous studies have linked eating lots of fruits and vegetables that are high in antioxidants to lower risk of cancer and heart disease. So with this in mind, a research team in Italy decided to see if it could create even more healthful berries that taste even better.


For their study, the researchers bred wild strawberries with a commercial variety. “We already released a new variety (Romina) with increased high nutritional quality of the fruit in comparison with other varieties on the market (e.g. Elsanta),” said Bruno Mezzetti, who headed the team of scientists. “But then by crossing wild strawberries with cultivated genotypes we were able to develop new genotypes with a further higher content of antioxidants that looked pleasing to the eye and tasted quite sweet.” The new plants also produced a good yield of berries, he added.


Overall, the researchers worked with 20 kinds of strawberries they created and their “parents,” checking them for weight, yield, sugar content, acidity and antioxidant content. Based on their analysis, they concluded that a full-scale breeding program can produce new strawberry varieties that are superior to current commercial crops.


Mezzetti says the group’s ultimate aim is to produce these “super-good” strawberries that will be sold commercially. First, they will test the berries further in the lab and then, possibly, with human volunteers to determine even more definitively if the fruit has added health benefits and is even tastier than current varieties.

 

 

Use of Wild Genotypes in Breeding Program Increases Strawberry Fruit Sensorial and

Nutritional Quality”

 

Click here for the abstract.

 

*Journalists can request a PDF of the journal article by emailing newsroom@acs.org.

 

strawberries blog.jpg

 

               Credit: iurii Konoval/ iStock/Thinkstock
                 
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Looking to nature for materials to use in everyday products has its appeal and has spurred earnest research efforts toward this end. The approach seems more healthful than turning to synthetic materials — but nature is not always benign. Luckily, there are scientists acting as watchdogs over this enterprise to make sure at least some of what’s natural in our products is actually a good thing. GreenLabelSmall.jpg

 

In a new study, one team led by Anna Shvedova, Ph.D., has looked at materials called cellulose nanocrystals (CNCs), which are the most abundant natural biopolymers on the planet. Her team’s report from the journal ACS Sustainable Chemistry & Engineering states that CNCs have a lot of traits that are useful.


CNCs can lend desirable strength, and electrical and magnetic properties to products. They’re also biodegradable and come from renewable sources such as wood, bacteria and algae. Because of their all-around appeal, CNCs have made it into an impressive array of products.

             

“The novel generations of cellulose products are already manufactured and used for a number of applications in spray paints, cosmetics, packaging, construction and building insulation,” says Shvedova, who’s with the Centers for Disease Control and Prevention and West Virginia University.

 

What could be safer or more sustainable?

 

As it turns out, perhaps a lot of things. Shvedova tested these CNCs for health effects in mice. Her team found that these otherwise promising materials caused pulmonary inflammation and lung damage that is more severe than that caused by crocidolite asbestos, one of six kinds of the mineral. This could pose a serious health risk to manufacturing employees who work with CNCs and might inhale them.

 

“The major point to emphasize is that this nanomaterial should be handled carefully,” Shvedova says.

 

There is a bit of good news in all this. Shvedova also found that the way the CNCs were produced made a big difference in how they affected the animals’ health.

 

“Taken together, our data suggests that particle morphology and nanosize dimensions of CNCs, regardless of the source and chemical composition, may be critical factors affecting the type of innate immune inflammatory response,” she says. “As the need for manufacturing novel frontier nanocellulose materials for various applications including consumer products rises over the years, a detailed assessment of specific health outcomes with respect to their physical, structural and chemical properties is highly warranted.”

 

Shvedova’s work raises the persistent, modern question: How do we balance consumption with safeguarding our health and environment?

 

Click here for the abstract.


Image credit: Aquir/iStock/Thinkstock

While climate change discussions focus largely on carbon dioxide, emissions of the third-most important greenhouse gas is rising dramatically in China. And not only does this gas, nitrous oxide (N2O), contribute to the greenhouse effect, but it also threatens to eat away at the ozone layer, which protects us by absorbing some of the ultraviolet light from the sun. Concerned about the double threat of N2O, researchers from Peking University took a closer look at its historical and future emissions. Here are the highlights of a Q&A with Jianhua Xu on what his team found and what it means for the planet.

n2oSmall.jpg

 

Q.     What’s the most important finding from your study?

 

A.     China has become the world’s largest industrial N2O emitter. From 1990 to 2010, industrial N2O emissions in China grew 34-fold to 160 Gg (176,000 tons), while global industrial N2O emissions decreased by 41 percent to 379 Gg (418,000 tons) and the total industrial N2O emissions from Annex I countries (a group of industrialized and developing nations that are party to the United Nations Framework Convention on Climate Change) decreased by 71 percent to 171 Gg (188,000 tons). By 2009, the emissions from China surpassed those from the European Union and United States for the first time.

 

 

Q.     The Montreal Protocol phased out chlorofluorocarbons (CFCs) and led to the still-ongoing but largely successful recovery of the ozone layer. If N2O emissions continue to rise, how will it affect this recovery?

 

A.     N2O possesses a small ozone-depleting potential (ODP) of only 0.017, which is around one-sixtieth of CFC-11, a typical CFC regulated under the Montreal Protocol. However, its mild ODP could be quite insidious because the current anthropogenic N2O emissions are much larger than the past and future CFC emissions worldwide. This makes anthropogenic N2O emissions the single most important of the anthropogenic ozone-depleting emissions today and throughout the 21st century. If the atmospheric N2O level were to remain flat, a complete recovery of the ozone layer is projected to occur by around 2025-20281. But the increase in the atmospheric N2O level at the current pace could delay the complete recovery by a decade, although drawing down CFCs under the Montreal Protocol has provided all possible relief1.

 

 

Q.     There is a lot of focus on CO2 emissions’ effects on climate change. What would happen to our climate if we dramatically reduced CO2 emissions but allowed N2O to rise unchecked?

 

A.     Although CO2 is and will always be the largest contributor to global radiative forcing in climate change, global warming will not be alleviated if CO2 is reduced but N2O continues to rise. Currently, N2O is the third most important greenhouse gas, and its total anthropogenic emissions are projected to ascend by 58 percent and the global average N2O abundance by 13 percent by 20502.

 

     Over 60 percent of global anthropogenic N2O emissions reside in agricultural activities. Improving fertilizer-use efficiency, applying nitrification inhibitors and controlled-released fertilizers are regarded as the most cost-effective control options3, but these practices are not widespread in most agriculture-dominant developing countries. If it remains unchecked, the increased radiative forcing — a change in the Earth’s energy balance between incoming radiation from the sun and what gets bounced back into space — could make up the net climate benefit from CO2 abatement.

 

 

Q.     Are there technological solutions N2O-producing industries can implement now to reduce their emissions? How costly are they?

 

A.     Yes, there are a few feasible technologies to abate industrial N2O emissions. But in China, the lowest cost for one such project was $10 million, and the net present value was minus $30 million (meaning the project was not profitable) for the entire 21-year operation. In my understanding, the availability of abatement technology is not an issue in the current situation, but the design and implementation of effective policies and regulatory programs are.

 

To read the full Q&A, click here.

 

Click here for the abstract.

 

Image credit: telnyawka/iStock/Thinkstock


References

  1. Chipperfield, M., Atmospheric science: nitrous oxide delays ozone recovery. Nature Geoscience 2009, 2, (11), 742-743.
  2. Intergovernmental Panel on Climate Change (IPCC), Contribution of working group I: the physical science basis. In Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Thomas, S.; Qin, D.; Gian-Kasper, P., Eds. Cambridge University Press: Cambridge, United Kingdom and New York, USA, 2013.
  3. Kanter, D.; Mauzerall, D. L.; Ravishankara, A.; Daniel, J. S.; Portmann, R. W.; Grabiel, P. M.; Moomaw, W. R.; Galloway, J. N., A post-Kyoto partner: Considering the stratospheric ozone regime as a tool to manage nitrous oxide. Proc. Natl. Acad. Sci. USA 2013, 110, (12), 4451-4457.