News from the NNI Community - Research Advances Funded by Agencies Participating in the NNI

The process of crystallization, in which atoms or molecules line up in orderly arrays like soldiers in formation, is the basis for many of the materials that define modern life, including the silicon in microchips and solar cells. But there has been a dearth of good tools for studying this type of growth. Now, a team of researchers at MIT and the Charles Stark Draper Laboratory, both in Cambridge, MA, has found a way to reproduce the growth of crystals on surfaces, but at a larger scale, which makes the process easier to study and analyze. Rather than assembling these crystals from actual atoms, the researchers used spherical nanoparticles of gold, coated with specially selected single strands of genetically engineered DNA.

Researchers have discovered how two-dimensional cages trap some noble gases. These cages are only nanometers, or billionths of a meter, thick. They can trap atoms of argon, krypton, and xenon at above-freezing temperatures. Noble gases are hard to trap using other methods, because they condense at temperatures far below freezing.

Researchers have discovered how two-dimensional cages trap some noble gases. These cages are only nanometers, or billionths of a meter, thick. They can trap atoms of argon, krypton, and xenon at above-freezing temperatures. Noble gases are hard to trap using other methods, because they condense at temperatures far below freezing.

For the past eight years, chemists at the University of California, Berkeley, and Lawrence Berkeley National Laboratory have been working on a hybrid system combining bacteria and nanowires that can capture the energy of sunlight to convert carbon dioxide and water into building blocks for organic molecules. The researchers have now reported a milestone in packing these bacteria into a "forest of nanowires" to achieve a record efficiency: 3.6% of the incoming solar energy is converted and stored in carbon bonds, in the form of a two-carbon molecule called acetate. Acetate molecules can serve as building blocks for fuels, plastics, and drugs.

For the past eight years, chemists at the University of California, Berkeley, and Lawrence Berkeley National Laboratory have been working on a hybrid system combining bacteria and nanowires that can capture the energy of sunlight to convert carbon dioxide and water into building blocks for organic molecules. The researchers have now reported a milestone in packing these bacteria into a "forest of nanowires" to achieve a record efficiency: 3.6% of the incoming solar energy is converted and stored in carbon bonds, in the form of a two-carbon molecule called acetate. Acetate molecules can serve as building blocks for fuels, plastics, and drugs.

Any device that sends out a Wi-Fi signal also emits terahertz waves — electromagnetic waves with a frequency somewhere between microwaves and infrared light. Now, physicists at MIT have come up with a blueprint for a device they believe would be able to convert ambient terahertz waves into a direct current, a form of electricity that powers many household electronics. Their design takes advantage of the quantum mechanical behavior of graphene.

Any device that sends out a Wi-Fi signal also emits terahertz waves — electromagnetic waves with a frequency somewhere between microwaves and infrared light. Now, physicists at MIT have come up with a blueprint for a device they believe would be able to convert ambient terahertz waves into a direct current, a form of electricity that powers many household electronics. Their design takes advantage of the quantum mechanical behavior of graphene.

Researchers led by biomedical engineers at Tufts University have invented a microfluidic chip containing cardiac cells that can mimic hypoxic conditions following a heart attack. The chip contains multiplexed arrays of electronic sensors placed outside and inside the cells. After reducing levels of oxygen in the fluid within the device, the sensors detect an initial period of accelerated beat rate, followed by a reduction in beat rate and eventually arrhythmia which mimics cardiac arrest. The biosensor technology used in the microfluidic chip combines multi-electrode arrays that can provide extracellular readouts of voltage patterns, with nanopillar probes that enter the membrane to take readouts of voltage levels within each cell.

Researchers led by biomedical engineers at Tufts University have invented a microfluidic chip containing cardiac cells that can mimic hypoxic conditions following a heart attack. The chip contains multiplexed arrays of electronic sensors placed outside and inside the cells. After reducing levels of oxygen in the fluid within the device, the sensors detect an initial period of accelerated beat rate, followed by a reduction in beat rate and eventually arrhythmia which mimics cardiac arrest. The biosensor technology used in the microfluidic chip combines multi-electrode arrays that can provide extracellular readouts of voltage patterns, with nanopillar probes that enter the membrane to take readouts of voltage levels within each cell.

Researchers in the cancer nanomedicine community debate whether use of nanoparticles can best deliver drug therapy to tumors passively – allowing the nanoparticles to diffuse into tumors and become held in place – or actively, by adding an anti-cancer molecule that would bind to specific cancer cell receptors and, in theory, keep the nanoparticles in the tumor longer. Now, researchers at the Johns Hopkins Kimmel Cancer Center have found that nanoparticles coated with trastuzumab, a drug sold under the name Herceptin that targets breast cancer cells, were better retained in tumors than plain nanoparticles. The researchers also found that immune cells exposed to nanoparticles induced an anti-cancer immune response by activating T cells, which invaded tumors and slowed tumor growth.