New Plan of Attack in Cancer Fight: Two-Drug Combination, Under Certain Circumstances, Can Eliminate Disease

New research is laying out a road map to one of the holy grails of modern medicine: a cure for cancer. (Credit: © Ivelin Radkov / Fotolia)

July 19, 2013 — New research conducted by Harvard scientists is laying out a road map to one of the holy grails of modern medicine: a cure for cancer.

As described in a paper recently published in eLife, Martin Nowak, a professor of mathematics and of biology and director of the Program for Evolutionary Dynamics, and co-author Ivana Bozic, a postdoctoral fellow in mathematics, show that, under certain conditions, using two drugs in a "targeted therapy" -- a treatment approach designed to interrupt cancer's ability to grow and spread -- could effectively cure nearly all cancers.

Though the research is not a cure for cancer, Nowak said it does offer hope to researchers and patients alike.

"In some sense this is like the mathematics that allows us to calculate how to send a rocket to the moon, but it doesn't tell you how to build a rocket that goes to the moon," Nowak said. "What we found is that if you have a single point mutation in the genome that can give rise to resistance to both drugs at the same time, the game is over. We need to have combinations such that there is zero overlap between the drugs."

Importantly, Nowak said, for the two-drug combination to work, both drugs must be given together -- an idea that runs counter to the way many clinicians treat cancer today.

"We actually have to work against the status quo somewhat," he said. "But we can show in our model that if you don't give the drugs simultaneously, it guarantees treatment failure."

In earlier studies, Nowak and colleagues showed the importance of using multiple drugs. Though temporarily effective, single-drug targeted therapy will fail, the researchers revealed, because the disease eventually develops resistance to the treatment.

To determine if a two-drug combination would work, Nowak and Bozic turned to an expansive data set supplied by clinicians at New York's Memorial Sloan-Kettering Cancer Center that showed how patients respond to single-drug therapy. With data in hand, they were able to create computer models of how multidrug treatments would work. Using that model, they then treated a series of "virtual patients" to determine how the disease would react to the multidrug therapy.

"For a single-drug therapy, we know there are between 10 and 100 places in the genome that, if mutated, can give rise to resistance," Nowak explained. "So the first parameter we use when we make our calculations is that the first drug can be defeated by those possible mutations. The second drug can also be defeated by 10 to 100 mutations.

"If any of those mutations are the same, then it's a disaster," he continued. "If there's even a single mutation that can defeat both drugs, that is usually good enough for the cancer -- it will become resistant, and treatment will fail. What this means is we have to develop drugs such that the cancer needs to make two independent steps -- if we can do that, we have a good chance to contain it."

How good a chance?

"You would expect to cure most patients with a two-drug combination," Bozic said. "In patients with a particularly large disease burden you might want to use a three-drug combination, but you would cure most with two drugs."

The trick now, Nowak and Bozic said, is to develop those drugs.

To avoid developing drugs that are not vulnerable to the same mutation, Bozic said, pharmaceutical companies have explored a number of strategies, including using different drugs to target different pathways in cancer's development.

"There are pharmaceutical companies here in Cambridge that are working to develop these drugs," Nowak said. "There may soon be as many as 100 therapies, which means there will be as many as 10,000 possible combinations, so we should have a good repertoire to choose from.

"I think we can be confident that, within 50 years, many cancer deaths will be prevented," Nowak added. "One hundred years ago, many people died from bacterial infections, and now they would be cured. Today, many people die from cancer, and we can't help them, but I think once we have these targeted therapies, we will be able to help many people -- maybe not everyone -- but many people."

Story Source:

The above story is reprinted from materials provided byHarvard University. The original article was written by Peter Reuell.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Ivana Bozic, Johannes G Reiter, Benjamin Allen, Tibor Antal, Krishnendu Chatterjee, Preya Shah, Yo Sup Moon, Amin Yaqubie, Nicole Kelly, Dung T Le, Evan J Lipson, Paul B Chapman, Luis A Diaz, Bert Vogelstein, Martin A Nowak.Evolutionary dynamics of cancer in response to targeted combination therapy. eLife, 2013 DOI:10.7554/eLife.00747.001

Snow in an Infant Solar System: A Frosty Landmark for Planet and Comet Formation

An artist's concept of the snow line in TW Hydrae showing water ice covered dust grains in the inner disc (4.5–30 astronomical units, blue) and carbon monoxide ice covered grains in the outer disc (>30 astronomical units, green). The transition from blue to green marks the carbon monoxide snow line. The snow helps grains of dust to adhere to each other by providing a sticky coating, which is essential to the formation of planets and comets. Due to the different freezing points of different chemical compounds, different snow lines can be found at various distances from the star. (Credit: B. Saxton & A. Angelich/NRAO/AUI/NSF/ALMA (ESO/NAOJ/NRAO))

July 18, 2013 — A snow line has been imaged in a far-off infant solar system for the very first time. The snow line, located in the disc around the Sun-like star TW Hydrae, promises to tell us more about the formation of planets and comets, the factors that decide their composition, and the history of the Solar System.

The results are published today inScience Express.

Astronomers using the Atacama Large Millimeter/submillimeter Array have taken the first ever image of the snow line in an infant solar system. On Earth, snow lines form at high altitudes where falling temperatures turn the moisture in the air into snow. This line is clearly visible on a mountain, where the snow-capped summit ends and the rocky face begins.

The snow lines around young stars form in a similar way, in the distant, colder reaches of the dusty discs from which solar systems form. Starting from the star and moving outwards, water (H₂O) is the first to freeze, forming the first snow line. Further out from the star, as temperatures drop, more exotic molecules can freeze and turn to snow, such as carbon dioxide (CO₂), methane (CH₄), and carbon monoxide (CO). These different snows give the dust grains a sticky outer coating and play an essential role in helping the grains to overcome their usual tendency to break up in collisions, allowing them to become the crucial building blocks of planets and comets. The snow also increases how much solid matter is available and may dramatically speed up the planetary formation process.

Each of these different snow lines -- for water, carbon dioxide, methane and carbon monoxide -- may be linked to the formation of particular kinds of planets [1]. Around a Sun-like star in a solar system like our own, the water snow line would correspond to a distance between the orbits of Mars and Jupiter, and the carbon monoxide snow line would correspond to the orbit of Neptune.

The snow line spotted by ALMA is the first glimpse of the carbon monoxide snow line, around TW Hydrae, a young star 175 light-years away from Earth. Astronomers believe this budding solar system shares many of the same characteristics of the Solar System when it was just a few million years old.

"ALMA has given us the first real picture of a snow line around a young star, which is extremely exciting because of what it tells us about the very early period in the history of the Solar System," said Chunhua "Charlie" Qi (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA) one of the two lead authors of the paper. "We can now see previously hidden details about the frozen outer reaches of another solar system similar to our own."

But the presence of a carbon monoxide snow line could have greater consequences than just the formation of planets. Carbon monoxide ice is needed to form methanol, which is a building block of the more complex organic molecules that are essential for life. If comets ferried these molecules to newly forming Earth-like planets, these planets would then be equipped with the ingredients necessary for life.

Before now, snow lines had never been imaged directly because they always form in the relatively narrow central plane of a protoplanetary disc, so their precise location and extent could not be determined. Above and below the narrow region where snow lines exist, the star's radiation prevents ice formation. The dust and gas concentration in the central plane is necessary to insulate the area from the radiation so that carbon monoxide and other gases can cool and freeze.

This team of astronomers succeeded in peering inside this disc to where the snow has formed with the help of a clever trick. Instead of looking for the snow -- as it cannot be observed directly -- they searched for a molecule known as diazenylium (N2H+), which shines brightly in the millimetre portion of the spectrum, and so is a perfect target for a telescope such as ALMA. The fragile molecule is easily destroyed in the presence of carbon monoxide gas, so would only appear in detectable amounts in regions where carbon monoxide had become snow and could no longer destroy it. In essence, the key to finding carbon monoxide snow lies in finding diazenylium.

ALMA's unique sensitivity and resolution has allowed the astronomers to trace the presence and distribution of diazenylium and find a clearly defined boundary approximately 30 astronomical units from the star (30 times the distance between Earth and Sun). This gives, in effect, a negative image of the carbon monoxide snow in the disc surrounding TW Hydrae, which can be used to see the carbon monoxide snow line precisely where theory predicts it should be -- the inner rim of the diazenylium ring.

"For these observations we used only 26 of ALMA's eventual full complement of 66 antennas. Indications of snow lines around other stars are already showing up in other ALMA observations, and we are convinced that future observations with the full array will reveal many more of these and provide further, exciting insights into the formation and evolution of planets. Just wait and see," concludes Michiel Hogerheijde from Leiden Observatory, the Netherlands.

Story Source:

The above story is reprinted from materials provided byEuropean Southern Observatory - ESO.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Chunhua Qi, Karin I. Öberg, David J. Wilner, Paola d'Alessio, Edwin Bergin, Sean M. Andrews, Geoffrey A. Blake, Michiel R. Hogerheijde, and Ewine F. van Dishoeck. Imaging of the CO Snow Line in a Solar Nebula Analog. Science, 18 July 2013 DOI: 10.1126/science.1239560

How Mars' Atmosphere Got So Thin: Reports Detail Curiosity Clues to Atmosphere's Past

This picture shows a lab demonstration of the measurement chamber inside the Tunable Laser Spectrometer, an instrument that is part of the Sample Analysis at Mars investigation on NASA's Curiosity rover. (Credit: NASA/JPL-Caltech)

July 18, 2013 — A pair of new papers report measurements of the Martian atmosphere's composition by NASA's Curiosity rover, providing evidence about loss of much of Mars' original atmosphere.

Curiosity's Sample Analysis at Mars (SAM) suite of laboratory instruments inside the rover has measured the abundances of different gases and different isotopes in several samples of Martian atmosphere. Isotopes are variants of the same chemical element with different atomic weights due to having different numbers of neutrons, such as the most common carbon isotope, carbon-12, and a heavier stable isotope, carbon-13.

SAM checked ratios of heavier to lighter isotopes of carbon and oxygen in the carbon dioxide that makes up most of the planet's atmosphere. Heavy isotopes of carbon and oxygen are both enriched in today's thin Martian atmosphere compared with the proportions in the raw material that formed Mars, as deduced from proportions in the sun and other parts of the solar system. This provides not only supportive evidence for the loss of much of the planet's original atmosphere, but also a clue to how the loss occurred.

"As atmosphere was lost, the signature of the process was embedded in the isotopic ratio," said Paul Mahaffy of NASA Goddard Space Flight Center, Greenbelt, Md. He is the principal investigator for SAM and lead author of one of the two papers about Curiosity results in the July 19 issue of the journalScience.

Other factors also suggest Mars once had a much thicker atmosphere, such as evidence of persistent presence of liquid water on the planet's surface long ago even though the atmosphere is too scant for liquid water to persist on the surface now. The enrichment of heavier isotopes measured in the dominant carbon-dioxide gas points to a process of loss from the top of the atmosphere -- favoring loss of lighter isotopes -- rather than a process of the lower atmosphere interacting with the ground.

Curiosity measured the same pattern in isotopes of hydrogen, as well as carbon and oxygen, consistent with a loss of a substantial fraction of Mars' original atmosphere. Enrichment in heavier isotopes in the Martian atmosphere has previously been measured on Mars and in gas bubbles inside meteorites from Mars. Meteorite measurements indicate much of the atmospheric loss may have occurred during the first billion years of the planet's 4.6-billion-year history. The Curiosity measurements reported this week provide more precise measurements to compare with meteorite studies and with models of atmospheric loss.

The Curiosity measurements do not directly measure the current rate of atmospheric escape, but NASA's next mission to Mars, the Mars Atmosphere and Volatile Evolution Mission (MAVEN), will do so. "The current pace of the loss is exactly what the MAVEN mission now scheduled to launch in November of this year is designed to determine," Mahaffy said.

The new reports describe analysis of Martian atmosphere samples with two different SAM instruments during the initial 16 weeks of the rover's mission on Mars, which is now in its 50th week. SAM's mass spectrometer and tunable laser spectrometer independently measured virtually identical ratios of carbon-13 to carbon-12. SAM also includes a gas chromatograph and uses all three instruments to analyze rocks and soil, as well as atmosphere.

"Getting the same result with two very different techniques increased our confidence that there's no unknown systematic error underlying the measurements," said Chris Webster of NASA's Jet Propulsion Laboratory, Pasadena, Calif. He is the lead scientist for the tunable laser spectrometer and the lead author for one of the two papers. "The accuracy in these new measurements improves the basis for understanding the atmosphere's history."

Curiosity landed inside Mars' Gale Crater on Aug. 6, 2012 Universal Time (on Aug. 5 PDT). The rover this month began a drive of many months from an area where it found evidence for a past environment favorable for microbial life, toward a layered mound, Mount Sharp, where researchers will seek evidence about how the environment changed.

More information about Curiosity is online at:http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ .

You can follow the mission on Facebook at:http://www.facebook.com/marscuriosity and on Twitter athttp://www.twitter.com/marscuriosity .

Story Source:

The above story is reprinted from materials provided byNASA.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal References:

1. C. R. Webster, P. R. Mahaffy, G. J. Flesch, P. B. Niles, J. H. Jones, L. A. Leshin, S. K. Atreya, J. C. Stern, L. E. Christensen, T. Owen, H. Franz, R. O. Pepin, A. Steele.Isotope Ratios of H, C, and O in CO₂ and H₂O of the Martian Atmosphere. Science, 2013; 341 (6143): 260 DOI:10.1126/science.1237961
2. Paul R. Mahaffy, Christopher R. Webster, Sushil K. Atreya, Heather Franz, Michael Wong, Pamela G. Conrad, Dan Harpold, John J. Jones, Laurie A. Leshin, Heidi Manning, Tobias Owen, Robert O. Pepin, Steven Squyres, Melissa Trainer, and MSL Science Team. Abundance and Isotopic Composition of Gases in the Martian Atmosphere from the Curiosity Rover. Science, 2013; 341 (6143): 263 DOI:10.1126/science.1237966

Sun Emits a Solstice CME

This image from June 20, 2013, at 11:15 p.m. EDT shows the bright light of a solar flare on the left side of the sun and an eruption of solar material shooting through the sun’s atmosphere, called a prominence eruption. Shortly thereafter, this same region of the sun sent a coronal mass ejection out into space. (Credit: Credit: NASA/SDO)

June 23, 2013 — On June 20, 2013, at 11:24 p.m., the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of particles into space that can reach Earth one to three days later. These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.

Experimental NASA research models, based on observations from NASA's Solar Terrestrial Relations Observatory and ESA/NASA's Solar and Heliospheric Observatory show that the CME left the sun at speeds of around 1350 miles per second, which is a fast speed for CMEs.

Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth's magnetic envelope, the magnetosphere, for an extended period of time. The CME's magnetic fields peel back the outermost layers of Earth's fields changing their very shape. Magnetic storms can degrade communication signals and cause unexpected electrical surges in power grids. They also can cause aurora. Storms are rare during solar minimum, but as the sun's activity ramps up every 11 years toward solar maximum -- currently expected in late 2013 -- large storms occur several times per year.

In the past, geomagnetic storms caused by CMEs of this strength and direction have usually been mild.

In addition, the CME may pass by additional spacecraft: Messenger, STEREO B, Spitzer, and their mission operators have been notified. If warranted, operators can put spacecraft into safe mode to protect the instruments from the solar material.

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The above story is reprinted from materials provided byNASA/Goddard Space Flight Center.

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Mystery of X-Ray Light from Black Holes Solved

June 14, 2013 — It is a mystery that has stymied astrophysicists for decades: how do black holes produce so many high-power X-rays?

In a new study, astrophysicists from The Johns Hopkins University, NASA and the Rochester Institute of Technology conducted research that bridges the gap between theory and observation by demonstrating that gas spiraling toward a black hole inevitably results in X-ray emissions.

The paper states that as gas spirals toward a black hole through a formation called an accretion disk, it heats up to roughly 10 million degrees Celsius. The temperature in the main body of the disk is roughly 2,000 times hotter than the sun and emits low-energy or "soft" X-rays. However, observations also detect "hard" X-rays which produce up to 100 times higher energy levels.

Julian Krolik, professor of physics and astronomy in the Zanvyl Krieger School of Arts and Sciences, and his fellow scientists used a combination of supercomputer simulations and traditional hand-written calculations to uncover their findings. Supported by 40 years of theoretical progress, the team showed for the first time that high-energy light emission is not only possible, but is an inevitable outcome of gas being drawn into a black hole.

"Black holes are truly exotic, with extraordinarily high temperatures, incredibly rapid motions and gravity exhibiting the full weirdness of general relativity," Krolik said. "But our calculations show we can understand a lot about them using only standard physics principles."

The team's work was recently published in the print edition ofAstrophysical Journal. His collaborators on the study include Jeremy Schnittman, a research astrophysicist from the NASA Goddard Space Flight Center, and Scott Noble, an associate research scientist from the Center for Computational Relativity and Gravitation at RIT. Schnittman was lead author.

As the quality and quantity of the high-energy light observations improved over the years, evidence mounted showing that photons must be created in a hot, tenuous region called the corona. This corona, boiling violently above the comparatively cool disk, is similar to the corona surrounding the sun, which is responsible for much of the ultra-violet and X-ray luminosity seen in the solar spectrum.

While the team's study of black holes and high-energy light confirms a widely-held belief, the role of advancing modern technology should not be overlooked. A grant from the National Science Foundation enabled the team to access Ranger, a supercomputing system at the Texas Advanced Computing Center located at the University of Texas in Austin. Ranger worked over the course of about 27 days, over 600 hours, to solve the equations.

Noble developed the computer simulation solving all of the equations governing the complex motion of inflowing gas and its associated magnetic fields near an accreting black hole. The rising temperature, density and speed of the inflowing gas dramatically amplify magnetic fields threading through the disk, which then exert additional influence on the gas.

The result is a turbulent froth orbiting the black hole at speeds approaching the speed of light. The calculations simultaneously tracked the fluid, electrical and magnetic properties of the gas while also taking into account Einstein's theory of relativity.

"In some ways, we had to wait for technology to catch up with us," Krolik said. "It's the numerical simulations going on at this level of quality and resolution that make the results credible."

The scientists are all familiar with each other as their paths have all crossed with Krolik during graduate school at Johns Hopkins. Schnittman was previously a postdoctoral fellow mentored by Krolik from 2007 to 2010 while Noble was an assistant research scientist and instructor also under Krolik from 2006 to 2009.

The work was supported by the National Science Foundation Grants AST-0507455, AST- 0908336 and AST-1028087.

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The above story is reprinted from materials provided by Johns Hopkins University.

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Journal Reference:

1. Jeremy D. Schnittman, Julian H. Krolik, Scott C. Noble. X-RAY SPECTRA FROM MAGNETOHYDRODYNAMIC SIMULATIONS OF ACCRETING BLACK HOLES. The Astrophysical Journal, 2013; 769 (2): 156 DOI: 10.1088/0004-637X/769/2/156

How Diving Mammals Evolved Underwater Endurance

How did seals and sea lions and other aquatic mammals evolve the ability to survive for long periods underwater without breathing? (Credit: © Rafael Ben-Ari / Fotolia)

June 13, 2013 — Scientists at the University of Liverpool have shed new light on how diving mammals, such as the sperm whale, have evolved to survive for long periods underwater without breathing.

The team identified a distinctive molecular signature of the oxygen-binding protein myoglobin in the sperm whale and other diving mammals, which allowed them to trace the evolution of the muscle oxygen stores in more than 100 mammalian species, including their fossil ancestors.

Myoglobin, which gives meat its red colour, is present in high concentrations in elite mammalian divers, so high that the muscle is almost black in colour. Until now, however, very little was known about how this molecule is adapted in champion divers.

Proteins tend to stick together at high concentrations, impairing their function, so it was unclear how myoglobin was able to help the body store enough oxygen to allow mammals, such as whales and seals, to endure underwater for long periods of time without breathing. Elite mammalian divers can hold their breath for over an hour while they hunt in the depths of the oceans, while land mammals, such as humans, can hold their breath for only a few minutes.

Dr Michael Berenbrink, from the University's Institute of Integrative Biology, who led the international team, explains: "We studied the electrical charge on the surface of myoglobin and found that it increased in mammals that can dive underwater for long periods of time. We were surprised when we saw the same molecular signature in whales and seals, but also in semi-aquatic beavers, muskrats and even water shrews.

"By mapping this molecular signature onto the family tree of mammals, we were able to reconstruct the muscle oxygen stores in extinct ancestors of today's diving mammals. We were even able to report the first evidence of a common amphibious ancestor of modern sea cows, hyraxes and elephants that lived in shallow African waters some 65 million years ago."

Dr Scott Mirceta, PhD student on the project, added: "Our study suggests that the increased electrical charge of myoglobin in mammals that have high concentrations of this protein causes electro-repulsion, like similar poles of two magnets. This should prevent the proteins from sticking together and allow much higher concentrations of the oxygen-storing myoglobin in the muscles of these divers."

"We are really excited by this new find, because it allows us to align the anatomical changes that occurred during the land-to-water transitions of mammals with their actual physiological diving capacity. This is important for understanding the prey items that were available to these extinct animals and their overall importance for past aquatic ecosystems."

The research, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), could also help improve understanding of a number of human diseases where protein aggregation is a problem, such as Alzheimer's and diabetes, and could inform the development of artificial blood substitutes.

Dr Berenbrink added: "This finding illustrates the strength of combining molecular, physiological and evolutionary approaches to biological problems and, for the first time, allows us to put 'flesh' onto the bones of these long extinct divers."

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The above story is reprinted from materials provided byUniversity of Liverpool.

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Journal Reference:

1. S. Mirceta, A. V. Signore, J. M. Burns, A. R. Cossins, K. L. Campbell, M. Berenbrink. Evolution of Mammalian Diving Capacity Traced by Myoglobin Net Surface Charge.Science, 2013; 340 (6138): 1234192 DOI:10.1126/science.1234192

Discovery of New Material State Counterintuitive to Laws of Physics

It’s like squeezing a stone and forming a giant sponge,” said Argonne chemist Karena Chapman. “Materials are supposed to become denser and more compact under pressure. We are seeing the exact opposite." (Credit: Image courtesy of DOE/Argonne National Laboratory)

June 12, 2013 — When you squeeze something, it gets smaller. Unless you're at Argonne National Laboratory.

At the suburban Chicago laboratory, a group of scientists has seemingly defied the laws of physics and found a way to apply pressure to make a material expand instead of compress/contract.

"It's like squeezing a stone and forming a giant sponge," said Karena Chapman, a chemist at the U.S. Department of Energy laboratory. "Materials are supposed to become denser and more compact under pressure. We are seeing the exact opposite. The pressure-treated material has half the density of the original state. This is counterintuitive to the laws of physics."

Because this behavior seems impossible, Chapman and her colleagues spent several years testing and retesting the material until they believed the unbelievable and understood how the impossible could be possible. For every experiment, they got the same mind-bending results.

"The bonds in the material completely rearrange," Chapman said. "This just blows my mind."

This discovery will do more than rewrite the science text books; it could double the variety of porous framework materials available for manufacturing, health care and environmental sustainability.

Scientists use these framework materials, which have sponge-like holes in their structure, to trap, store and filter materials. The shape of the sponge-like holes makes them selectable for specific molecules, allowing their use as water filters, chemical sensors and compressible storage for carbon dioxide sequestration of hydrogen fuel cells. By tailoring release rates, scientists can adapt these frameworks to deliver drugs and initiate chemical reactions for the production of everything from plastics to foods.

"This could not only open up new materials to being porous, but it could also give us access to new structures for selectability and new release rates," said Peter Chupas, an Argonne chemist who helped discover the new materials.

The team published the details of their work in the May 22 issue of the Journal of the American Chemical Society in an article titled "Exploiting High Pressures to Generate Porosity, Polymorphism, And Lattice Expansion in the Nonporous Molecular Framework Zn(CN)₂ ."

The scientists put zinc cyanide, a material used in electroplating, in a diamond-anvil cell at the Advanced Photon Source (APS) at Argonne and applied high pressures of 0.9 to 1.8 gigapascals, or about 9,000 to 18,000 times the pressure of the atmosphere at sea level. This high pressure is within the range affordably reproducible by industry for bulk storage systems. By using different fluids around the material as it was squeezed, the scientists were able to create five new phases of material, two of which retained their new porous ability at normal pressure. The type of fluid used determined the shape of the sponge-like pores. This is the first time that hydrostatic pressure has been able to make dense materials with interpenetrated atomic frameworks into novel porous materials. Several series of in situ high-pressure X-ray powder diffraction experiments were performed at the 1-BM, 11-ID-B, and 17-BM beamlines of the APS to study the material transitions.

"By applying pressure, we were able to transform a normally dense, nonporous material into a range of new porous materials that can hold twice as much stuff," Chapman said. "This counterintuitive discovery will likely double the amount of available porous framework materials, which will greatly expand their use in pharmaceutical delivery, sequestration, material separation and catalysis."

The scientists will continue to test the new technique on other materials.

The research is funded by the U.S. Department of Energy's Office of Science.

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The above story is reprinted from materials provided byDOE/Argonne National Laboratory.

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Journal Reference:

1. Saul H. Lapidus, Gregory J. Halder, Peter J. Chupas, Karena W. Chapman. Exploiting High Pressures to Generate Porosity, Polymorphism, And Lattice Expansion in the Nonporous Molecular Framework Zn(CN)2. Journal of the American Chemical Society, 2013; 135 (20): 7621 DOI: 10.1021/ja4012707