New Twist On 1930s Technology May Become a 21st Century Weapon Against Global Warming
May 10, 2012
Far from being a pipe dream years away from reality, practical technology for capturing carbon dioxide -- the main greenhouse gas -- from smokestacks is aiming for deployment at coal-fired electric power generating stations and other sources, scientists saidin San Diego March 27. Their presentation at the 243rd National Meeting of the American Chemical Society was on a potential advance toward dealing with the 30 billion tons of carbon dioxide released into the air each year through human activity.
"With little fanfare or publicity and a decade of hard work, we have made many improvements in this important new technology for carbon capture," said James H. Davis, Jr., Ph.D., who headed the research. "In 2002, we became the first research group to disclose discovery of the technology, and we have now positioned it as a viable means for carbon dioxide capture. Our research indicates that its capacity for carbon dioxide capture is greater than current technology, and the process is shaping up to be both more affordable and durable as well."
The new approach has a back-to-the-future glint, leveraging technology that the petroleum industry has used since the 1930s to remove carbon dioxide and other impurities from natural gas. Davis, who is with the University of South Alabama (USA) in Mobile, explained that despite its reputation as a clean fuel, natural gas is usually contaminated with a variety of undesirable materials, especially carbon dioxide and hydrogen sulfide. Natural gas from certain underground formations, so-called "sweet" gas, has only small amounts of these other gases, while "sour" gas has larger amounts. Natural gas companies traditionally have used a thick, colorless liquid called aqueous monoethanolamine (MEA) to remove that carbon dioxide.
Several problems, however, would prevent use of MEA to capture carbon dioxide on the massive basis envisioned in some proposed campaigns to slow global warming. These involve, for instance, capturing or "scrubbing" the carbon dioxide from smokestacks before it enters the atmosphere and socking it away permanently in underground storage chambers. Vast amounts of MEA would be needed, and its loss into the atmosphere could create health and environmental problems, and it would be very costly.
Davis and his group believe that their new approach avoids those pitfalls. It makes use of a nitrogen-based substance termed an "ionic liquid" that binds to carbon dioxide very effectively. Unlike MEA, it is odorless, does not evaporate easily and can be easily recycled and reused.
Davis also described one important advantage the technology has over many other ionic liquid carbon-capture systems. He explained that the presence of water, like moisture in the atmosphere, reduces the effectiveness of many nitrogen-based ionic liquids, complicating their use. Water is always present in exhaust gases because it is a byproduct of combustion. Davis noted that the liquids prefer to interact with carbon dioxide over water, and thus are not hampered by the latter in real-world applications.
Although cautioning that the final application in power plants or factories may look different, Davis envisioned a possible set-up for power plants that would be similar to the one used in his laboratory. He described bubbling exhaust gas through a tank full of the nitrogen-based liquid, which the system could cycle out and replace with fresh liquid. Removing the carbon dioxide would create a new supply of ionic liquid. Once removed, companies could sequester the carbon dioxide by burying it or finding another way to keep it permanently out of the atmosphere. Others have suggested using captured carbon dioxide in place of petroleum products to make plastics and other products.
Davis suggested that in the future, people might also use the technology on a smaller scale in cars or homes, although he cautioned that these applications were likely a long way away. While his group has not fully explored the possible dangers of the chemicals his technology uses, Davis noted that his compounds are quite similar to certain compounds which are known to be safe for consumer use.
His presentation was part of a symposium on research advances involving "ionic liquids," strange liquids that consist only of atoms stripped of some of their electrons, with applications ranging from food processing to energy production.
Transparent, Flexible '3-D' Memory Chips May Be the Next Big Thing in Small Memory Devices
May 10, 2012
New memory chips that are transparent, flexible enough to be folded like a sheet of paper, shrug off 1,000-degree Fahrenheit temperatures -- twice as hot as the max in a kitchen oven -- and survive other hostile conditions could usher in the development of next-generation flash-competitive memory for tomorrow's keychain drives, cell phones and computers, a scientist reported March 27.
Speaking at the 243rd National Meeting & Exposition of the American Chemical Society, the world's largest scientific society, he said devices with these chips could retain data despite an accidental trip through the drier -- or even a voyage to Mars. And with a unique 3-D internal architecture, the new chips could pack extra gigabytes of data while taking up less space.
"These new chips are really big for the electronics industry because they are now looking for replacements for flash memory," said James M. Tour, Ph.D., who led the research team. "These new memory chips have numerous advantages over the chips today that are workhorses for data storage in hundreds of millions of flash, or thumb drives, smart phones, computers and other products. Flash has about another six or seven years in which it can be built smaller, but then developers hit fundamental barriers."
Because of the way that the new memory chips are configured, namely with two terminals per bit of information rather than the standard three terminals per bit, they are much better suited for the next revolution in electronics -- 3-D memory -- than flash drives.
"In order to put more memory into a smaller area, you have to stack components beyond two dimensions, which is what is currently available," he said. "You have to go to 3-D." And the chips have a high on-off ratio, which is a measure of how much electrical current can flow in the chip when it stores information versus when it is empty. The higher the ratio, the more attractive the chips are to manufacturers.
The chips were originally composed of a layer of graphene or other carbon material on top of silicon oxide, which has long been considered an insulator, a passive component in electronic devices. Graphene is a thin layer of carbon atoms that's touted as a "miracle material" because it is the thinnest and strongest known material. It was even the topic of a recent Nobel Prize. Originally, the researchers at Rice University thought that the amazing memory capability of the chips was due to the graphene. They discovered recently that they were wrong. The silicon oxide surface was actually making the memories, and now they can make them graphene-free. The work was done by Tour's group in collaboration with Professor Douglas Natelson (Department of Physics) and Lin Zhong (Department of Electrical and Computer Engineering). The main students on the project were Jun Yao and Javen Lin.
The transparency and small size of the new chips enables them to be used in a wide range of potential applications. Manufacturers could embed them in glass for see-through windshield displays for everyday driving, military and space uses so that not only is the display in the windshield, but also the memory. That frees up space elsewhere in the vehicle for other devices and functionalities. In fact, the chips were onboard a recent Russian Progress 44 cargo spacecraft in August 2011 for further experimentation aboard the International Space Station. However, the vehicle never made it into space and crashed. "The spacecraft crashed over Siberia, so our chips are in Siberia!" said Tour. He hopes to send the chips on a future mission in July 2012 to see how the memory holds up in the high-radiation environment of space.
Current touch screens are made of indium tin oxide and glass, both of which are brittle and can break easily. However, plastic containing the memory chips could replace those screens with the added bonuses of being flexible while also storing large amounts of memory, freeing up space elsewhere in a phone for other components that could provide other services and functions. Alternatively, storing memory in small chips in the screen instead of within large components inside the body of a phone could allow manufacturers to make these devices much thinner.
The easy-to-fabricate memory chips are patented, and Tour is talking to manufacturers about embedding the chips into products.
The scientists acknowledged funding from the Texas Instruments Leadership University Fund, the National Science Foundation Award No. 0720825 and the Army Research Office through the SBIR program administrated by PrivaTran, LLC.
Researchers Discover a New Path for Light Through Metal
May 10, 2012
Helping bridge the gap between photonics and electronics, researchers from Purdue University have coaxed a thin film of titanium nitride into transporting plasmons, tiny electron excitations coupled to light that can direct and manipulate optical signals on the nanoscale. Titanium nitride's addition to the short list of surface-plasmon-supporting materials, formerly composed only of metals, could point the way to a new class of optoelectronic devices with unprecedented speed and efficiency.
"We have found that titanium nitride is a promising candidate for an entirely new class of technologies based on plasmonics and metamaterials," said Alexandra Boltasseva, a researcher at Purdue and an author on a paper published March 27 in the Optical Society's (OSA) open-access journal Optical Materials Express. "This is particularly compelling because surface plasmons resolve a basic mismatch between wavelength-scale optical devices and the much smaller components of integrated electronic circuits."
Value of Plasmons
Metals carry electricity with ease, but normally do nothing to transmit light waves. Surface plasmons, unusual light-coupled oscillations that form on the surface of metallic materials, are the exception to that rule. When excited on the surface of metals by light waves of specific frequencies, plasmons are able to retain that same frequency, but with wavelengths that are orders-of-magnitude smaller, cramming visible and near-infrared light into the realm of the nanoscale.
In the world of electronics and optics, that 100-fold contraction is a boon. Circuits that direct the paths of electrons operate on a much smaller scale than optical light waves, so engineers must either rely on small but relatively sluggish electrons for information processing or bulk up to accommodate the zippy photons. Plasmons represent the best of both worlds and are already at the heart of a number of optoelectronic devices. They have not had widespread use, however, due to the dearth of materials that readily generate them and the fact that metals, in most cases, cannot be integrated with semiconductor devices.
Until now, the best candidates for plasmonic materials were gold and silver. These noble metals, however, are not compatible with standard silicon manufacturing technologies, limiting their use in commercial products. Silver is the metal with the best optical and surface plasmon properties, but it forms grainy, or semi-continuous, thin films. Silver also easily degrades in air, which causes loss of optical signal, making it a less-attractive material in plasmon technologies.
In an effort to overcome these drawbacks, Boltasseva and her team chose to study titanium nitride- a ceramic material that is commonly used as a barrier metal in microelectronics and to coat metal surfaces such as medical implants or machine tooling parts- because they could manipulate its properties in the manufacturing process. It also could be easily integrated into silicon products, and grown crystal-by-crystal, forming highly uniform, ultrathin films- properties that metals do not share.
To test its plasmonic capabilities, the researchers deposited a very thin, very even film of titanium nitride on a sapphire surface. They were able to confirm that titanium nitride supported the propagation of surface plasmons almost as efficiently as gold. Silver, under perfect conditions, was still more efficient for plasmonic applications, but its acknowledged signal loss limited its practical applications.
To further improve the performance of titanium nitride, the researchers are now looking into a manufacturing method known as molecular beam epitaxy, which would enable them to grow the films and layered structures known as superlattices crystal-by-crystal.
Technologies and Potential Applications
In addition to plasmonics, the researchers also speculate that titanium nitride may have applications in metamaterials, which are engineered materials that can be tailored for almost any application because of their extraordinary response to electromagnetic, acoustic, and thermal waves. Recently proposed applications of metamaterials include invisibility cloaks, optical black holes, nanoscale optics, data storage, and quantum information processing.
The search for alternatives to noble metals with improved optical properties, easier fabrication and integration capabilities could ultimately lead to real-life applications for plasmonics and metamaterials.
"Plasmonics is an important technology for nanoscale optical circuits, sensing, and data storage because it can focus light down to nanoscale," notes Boltasseva. "Titanium nitride is a promising candidate in the near-infrared and visible wavelength ranges. Unlike gold and silver, titanium nitride is compatible with standard semiconductor manufacturing technology and provides many advantages in its nanofabrication and integration."
According to the researchers, titanium nitride-based devices could provide nearly the same performance for some plasmonic applications. While noble metals like silver would still be the best choice for specific applications like negative index metamaterials, titanium nitride could outperform noble metals in other metamaterial and transformation optics devices, such as those based on hyperbolic metamaterials.
New Process Converts Polyethylene Into Carbon Fiber
May 10, 2012
Common material such as polyethylene used in plastic bags could be turned into something far more valuable through a process being developed at the Department of Energy's Oak Ridge National Laboratory.
In a paper published in Advanced Materials, a team led by Amit Naskar of the Materials Science and Technology Division outlined a method that allows not only for production of carbon fiber but also the ability to tailor the final product to specific applications.
"Our results represent what we believe will one day provide industry with a flexible technique for producing technologically innovative fibers in myriad configurations such as fiber bundle or non-woven mat assemblies," Naskar said.
Using a combination of multi-component fiber spinning and their sulfonation technique, Naskar and colleagues demonstrated that they can make polyethylene-base fibers with a customized surface contour and manipulate filament diameter down to the submicron scale. The patent-pending process also allows them to tune the porosity, making the material potentially useful for filtration, catalysis and electrochemical energy harvesting.
Naskar noted that the sulfonation process allows for great flexibility as the carbon fibers exhibit properties that are dictated by processing conditions. For this project, the researchers produced carbon fibers with unique cross-sectional geometry, from hollow circular to gear-shaped by using a multi-component melt extrusion-based fiber spinning method.
The possibilities are virtually endless, according to Naskar, who described the process.
"We dip the fiber bundle into an acid containing a chemical bath where it reacts and forms a black fiber that no longer will melt," Naskar said. "It is this sulfonation reaction that transforms the plastic fiber into an infusible form.
"At this stage, the plastic molecules bond, and with further heating cannot melt or flow. At very high temperatures, this fiber retains mostly carbon and all other elements volatize off in different gas or compound forms."
The researchers also noted that their discovery represents a success for DOE, which seeks advances in lightweight materials that can, among other things, help the U.S. auto industry design cars able to achieve more miles per gallon with no compromise in safety or comfort. And the raw material, which could come from grocery store plastic bags, carpet backing scraps and salvage, is abundant and inexpensive.
A group of European astronomers has discovered an ancient planetary system that is likely to be a survivor from one of the earliest cosmic eras, 13 billion years ago. The system consists of the star HIP 11952 and two planets, which have orbital periods of 290 and 7 days, respectively. Whereas planets usually form within clouds that include heavier chemical elements, the star HIP 11952 contains very little other than hydrogen and helium. The system promises to shed light on planet formation in the early universe -- under conditions quite different from those of later planetary systems, such as our own.
It is widely accepted that planets are formed in disks of gas and dust that swirl around young stars. But look into the details, and many open questions remain -- including the question of what it actually takes to make a planet. With a sample of, by now, more than 750 confirmed planets orbiting stars other than the Sun, astronomers have some idea of the diversity among planetary systems. But also, certain trends have emerged: Statistically, a star that contains more "metals" -- in astronomical parlance, the term includes all chemical elements other than hydrogen and helium -- is more likely to have planets.
This suggests a key question: Originally, the universe contained almost no chemical elements other than hydrogen and helium. Almost all heavier elements have been produced, over time inside stars, and then flung into space as massive stars end their lives in giant explosions (supernovae). So what about planet formation under conditions like those of the very early universe, say: 13 billion years ago? If metal-rich stars are more likely to form planets, are there, conversely, stars with a metal content so low that they cannot form planets at all? And if the answer is yes, then when, throughout cosmic history, should we expect the very first planets to form?
Now a group of astronomers, including researchers from the Max-Planck-Institute for Astronomy in Heidelberg, Germany, has discovered a planetary system that could help provide answers to those questions. As part of a survey targeting especially metal-poor stars, they identified two giant planets around a star known by its catalogue number as HIP 11952, a star in the constellation Cetus ("the whale" or "the sea monster") at a distance of about 375 light-years from Earth. By themselves, these planets, HIP 11952b and HIP 11952c, are not unusual. What is unusual is the fact that they orbit such an extremely metal-poor and, in particular, such a very old star!
For classical models of planet formation, which favor metal-rich stars when it comes to forming planets, planets around such a star should be extremely rare. Veronica Roccatagliata (University Observatory Munich), the principal investigator of the planet survey around metal-poor stars that led to the discovery, explains: "In 2010 we found the first example of such a metal-poor system, HIP 13044. Back then, we thought it might be a unique case; now, it seems as if there might be more planets around metal-poor stars than expected."
HIP 13044 became famous as the "exoplanet from another galaxy" -- the star is very likely part of a so-called stellar stream, the remnant of another galaxy swallowed by our own billions of years ago.
Compared to other exoplanetary systems, HIP 11952 is not only one that is extremely metal-poor, but, at an estimated age of 12.8 billion years, also one of the oldest systems known so far. "This is an archaeological find in our own backyard," adds Johny Setiawan of the Max Planck Institute for Astronomy, who led the study of HIP 11952: "These planets probably formed when our Galaxy itself was still a baby."
"We would like to discover and study more planetary systems of this kind. That would allow us to refine our theories of planet formation. The discovery of the planets of HIP 11952 shows that planets have been forming throughout the life of our Universe," adds Anna Pasquali from the Center for Astronomy at Heidelberg University (ZAH), a co-author of the paper.
'Ordinary' Black Hole Discovered 12 Million Light Years Away
May 10, 2012
An international team of scientists have discovered an 'ordinary' black hole in the 12 million light year-distant galaxy Centaurus A. This is the first time that a normal-size black hole has been detected away from the immediate vicinity of our own Galaxy. PhD student Mark Burke will present the discovery at the National Astronomy Meeting in Manchester.
Although exotic by everyday standards, black holes are everywhere. The lowest-mass black holes are formed when very massive stars reach the end of their lives, ejecting most of their material into space in a supernova explosion and leaving behind a compact core that collapses into a black hole. There are thought to be millions of these low-mass black holes distributed throughout every galaxy. Despite their ubiquity, they can be hard to detect as they do not emit light so are normally seen through their action on the objects around them, for example by dragging in material that then heats up in the process and emits X-rays. But despite this, the overwhelming majority of black holes have remained undetected.
In recent years, researchers have made some progress in finding ordinary black holes in binary systems, by looking for the X-ray emission produced when they suck in material from their companion stars. So far these objects have been relatively close by, either in our own Milky Way Galaxy or in nearby galaxies in the so-called Local Group (a cluster of galaxies relatively near the Milky Way that includes Andromeda).
Mr Burke works under the supervision of Birmingham University astronomer Dr Somak Raychaudhury and is part of an international team led by Ralph Kraft of the Harvard-Smithsonian Center for Astrophysics. The team used the orbiting Chandra X-ray observatory to make six 100,000-second long exposures of Centaurus A, detecting an object with 50,000 times the X-ray brightness of our Sun. A month later, it had dimmed by more than a factor of 10 and then later by a factor of more than 100, so became undetectable.
This behaviour is characteristic of a low mass black hole in a binary system during the final stages of an outburst and is typical of similar black holes in the Milky Way. It implies that the team made the first detection of a normal black hole so far away, for the first time opening up the opportunity to characterise the black hole population of other galaxies.
Mr Burke comments: "So far we've struggled to find many ordinary black holes in other galaxies, even though we know they are there. To confirm (or refute) our understanding of the evolution of stars we need to search for these objects, despite the difficulty of detecting them at large distances. If it turns out that black holes are either much rarer or much more common in other galaxies than in our own it would be a big challenge to some of the basic ideas that underpin astronomy."
The group now plan to look at the more than 50 other bright X-ray sources that reside within Centaurus A, identifying them as black holes or other exotic objects, and gain at least an inkling of the nature of a further 50 less luminous sources.
Capsule for Removing Radioactive Contamination from Milk, Fruit Juices, Other Beverages
May 10, 2012
Amid concerns about possible terrorist attacks with nuclear materials, and fresh memories of environmental contamination from the 2011 Fukushima Daiichi nuclear disaster in Japan, scientists have described the development of a capsule that can be dropped into water, milk, fruit juices and other foods to remove more than a dozen radioactive substances.
In a presentation at the 243rd National Meeting & Exposition of the American Chemical Society (ACS), they said the technology could be used on a large scale by food processors or packaged into a small capsule that consumers at the home-kitchen level could pop into beverage containers to make them safe for consumption.
"We repurposed and repackaged for radioactive decontamination of water and beverages a tried-and-true process that originally was developed to mine the oceans for uranium and remove uranium and heavy metals from heavily contaminated water," said Allen Apblett, Ph.D., who led the research team. "The accident at the Fukushima nuclear plant in Japan and ongoing concerns about possible terrorist use of nuclear materials that may contaminate food and water led us to shift the focus of this technology."
The technology also can remove arsenic, lead, cadmium and other heavy metals from water and fruit juices, Apblett said, adding that higher-than-expected levels of some of those metals have been reported in the past in certain juices. He is with Oklahoma State University in Stillwater.
Nanoparticles composed of metal oxides, various metals combined with oxygen, are the key ingredients in the process. The particles, so small that hundreds would fit on the period at the end of this sentence, react with radioactive materials and other unwanted substances and pull them out of solution. The particles can absorb all 15 of the so-called "actinide" chemical elements on the periodic table of the elements, as well as non-actinide radioactive metals (e.g., strontium), lead, arsenic and other non-radioactive elements.
The actinides all are radioactive metals, and they include some of the most dangerous substances associated with nuclear weapons and commercial nuclear power plant accidents like Fukushima. Among them are plutonium, actinium, curium and uranium.
In the simplest packaging of the technology, the metal-oxide nanoparticles would be packed inside a capsule similar to a medicine capsule, and then stirred around in a container of contaminated water or fruit juice. Radioactive metals would exit the liquid and concentrate inside the capsule. The capsule would be removed, leaving the beverage safe for consumption. In laboratory tests, it reduced the concentrations of these metals to levels that could not be detected, Apblett noted.
The technology is moving toward commercialization, with the first uses probably in purifying calcium dietary supplements to remove any traces of lead, cadmium and radiostrontium. Apblett said the capsule version could have appeal beyond protection against terrorist attacks or nuclear accidents, among consumers in areas with heavy metals in their water or food supplies, for instance.
The scientists acknowledged funding from the Oklahoma Economic Development Generating Excellence Program.
Bacteria Use Chat to Play the 'Prisoner's Dilemma' Game in Deciding Their Fate
May 10, 2012
When faced with life-or-death situations, bacteria -- and maybe even human cells -- use an extremely sophisticated version of "game theory" to consider their options and decide upon the best course of action, scientists reported in San Diego March 27. In a presentation at the 243rd National Meeting & Exposition of the American Chemical Society (ACS), they said microbes "play" a version of the classic "Prisoner's Dilemma" game.
José Onuchic, Ph.D., who headed the research team, said these and other new insights into the "chat" sessions that bacteria use to communicate among themselves -- information about cell stress, the colony density (quorum-sensing peptides) and the stress status and inclinations of neighboring cells (peptide pheromones) -- could have far-reaching medical applications.
"Using this form of cell-to-cell communication, colonies of billions or trillions of bacteria can literally reach a consensus on actions that impact people," Onuchic explained. "Bacteria that previously existed harmlessly on the on the skin, for instance, may exchange chemical signals and reach a consensus that their numbers are large enough to start an infection. Likewise, bacteria may decide to band together into communities called biofilms that make numerous chronic diseases difficult to treat -- urinary tract infections, for instance, cystic fibrosis and endocarditis."
Scientists now are pursuing hints that human cells engage in another form of chemical chit-chat, Onuchic said -- communication that may result in a decision to begin the uncontrolled division and growth that defines cancer. Likewise, cells in a malignant tumor may chat and spread, or metastasize, from their original location to establish a new tumor in the liver, lungs or brain.
"Understanding how cells make decisions could enable scientists to control those decisions," said Onuchic, who is with Rice University. "It would open the door to developing better drugs that have fewer side effects. For example, once we get a handle on this process, we might block the specific chemical messages that signal a tumor to grow, developing a medicine that wouldn't affect other body processes, reducing or eliminating side effects."
Before trying to determine the steps a human cell might take on the road to becoming cancerous, however, Onuchic and colleagues at Rice and Tel Aviv University are tackling bacteria. They turned to Bacillus subtilis, a common microbe found in colonies numbering into the billions in the soil and used as a model in several kinds of scientific research. Faced with drought, radiation, over-crowding or other harsh environmental conditions, B. subtilis engages in quorum sensing, with individual microbes releasing chemical compounds that enable it to check out how their neighbors are responding to the unfavorable environment.
Members of a colony of B. subtilis may decide to respond to the stressful environment in one of two ways. They may make a decision to turn themselves into "spores," a hibernation-like existence. Alternatively, they may opt for transformation into a state called "competency."
In sporulation, bacteria dump half of their DNA into the environment and encase themselves in a thick, armor-like shell that enables the microbe to endure harsh conditions for decades on end. Forming a spore involves more than 500 genes and can take about 10 hours to complete. When conditions improve, the spore turns into a regular bacterium again. Most bacteria, when faced with bad conditions, become spores. But a few -- about 1-2 percent in the wild -- "see" that their neighbors are becoming spores and decide to become competent. In doing so, they take up some of their neighbors' discarded DNA in a last-ditch effort to adapt to the harsh environment.
"Sporulation is a drastic, traumatic process," said Onuchic. "The advantage of competency is that the cell might be able to adapt and live normally without undergoing that drastic upheaval. But competency is risky -- if conditions don't improve fast enough, the competent cell could die before having a chance to become a spore. Also, the spores could decide to break out of hibernation and compete for resources. It's a complicated decision."
Onuchic's research suggests that the way cells make decisions is consistent with game theory, a concept used in math to analyze conflict and cooperation and made famous by the book and 2001 movie A Beautiful Mind , based on the life of John Nash, a Nobel Laureate in Economics.
Sporulation is like cooperating or confessing in the so-called "Prisoner's Dilemma," a famous example of game theory, Onuchic said. Becoming competent, however, is a selfish decision that exploits the misfortunes of others.
In the human version of the Prisoner's Dilemma, a player's prison sentence depends not only on their own decision whether to confess, but also on another prisoner's decision. In the game, two prisoners are separated and told that if one confesses, the confessor goes free, and the other prisoner gets a one-year sentence. If both confess, each serves three months. If both stay silent, then each serves one month. The trick is to see whether a player will be selfish by confessing for a chance at earning a "get-out-of-jail-free" pass while subjecting their partner to a long sentence.
"Just as in the classic Prisoner's Dilemma game, the bacteria have to weigh the pros and cons of their decisions," said Onuchic. "The bacteria make a decision based not only on what it knows about its own stress and environment, but it also has to think about what the other bacteria might do. So this is like the Prisoner's Dilemma being played with 1 trillion cells in a colony instead of just two people."
Using mathematics, biology and physics, Onuchic's team identified the proteins, genes and other substances involved in making such decisions for B. subtilis and how they interact with each other. The team's sights now are set on determining whether human cells undergo similar decision-making processes in health and disease.
New Way to Abate Heart Attacks Before Patients Get to the Hospital
May 10, 2012
Paramedics can reduce someone's chances of having a cardiac arrest or dying by 50 percent by immediately administering a mixture of glucose, insulin and potassium ("GIK") to people having a heart attack, according to research presented March 27 at the American College of Cardiology's 61st Annual Scientific Session.
The study showed that patients who received GIK immediately after being diagnosed with acute coronary syndrome -- which indicates a heart attack is either in progress or on the way -- were 50 percent less likely to have cardiac arrest (a condition in which the heart suddenly stops beating) or die than those who received a placebo, although the treatment did not prevent the heart attack from occurring. Over the first month following the event, patients who received GIK were 40 percent less likely to have cardiac arrest, die or be hospitalized for heart failure.
The effect was even more striking for patients with ST-elevation heart attacks, which require immediate treatment. For those patients, immediate GIK was associated with a 60 percent reduction in cardiac arrest or death.
"When started immediately in the home or on the way to the hospital -- even before the diagnosis is completely established -- GIK appears to reduce the size of heart attacks and to reduce by half the risk of having a cardiac arrest or dying," said Harry P. Selker, MD, MSPH, executive director of the Institute for Clinical Research and Health Policy Studies at Tufts Medical Center, who led the study with Joni Beshansky, RN, MPH, co-principal investigator and project director. "Acute coronary syndromes represent the largest cause of death in this country. GIK is a very inexpensive treatment that appears to have promise in reducing those deaths and morbidity."
The cost of the treatment is about $50.
"Because the trial is the first to show GIK is effective when used by paramedics in real-world community settings, it could have important implications for the treatment of heart attacks," Dr. Selker said. Previous clinical trials have shown no consistent effect, likely because the GIK was given too late to help. This study, the "IMMEDIATE Trial," was the first to test the effectiveness of administering GIK at the very first signs of a threatening heart attack, in the community, rather than waiting hours until the diagnosis was well-established at a hospital, as done in previous clinical trials.
"We wanted to do something that is effective and can be used anywhere," said Dr. Selker. "We've done a lot of studies of acute cardiac care in emergency departments and hospitals, but more people die of heart attacks outside the hospital than inside the hospital. Hundreds of thousands of people per year are dying out in the community; we wanted to direct our attention to those patients."
The researchers trained paramedics in 36 Emergency Medical Services systems in 13 cities across the country to administer GIK after determining that a patient was likely having a threatened or already established heart attack using electrocardiograph-based ACI-TIPI (acute cardiac ischemia time-insensitive predictive instrument) and thrombolytic predictive instrument decision support that prints patient-specific predictions on the top of an electrocardiogram. The paramedics used these predictions to decide if a patient would likely benefit from treatment. There were 911 patients randomized to receive either the GIK treatment or a placebo.
Administering GIK immediately also reduced the severity of the damage to the heart tissue from the heart attack. On average, 2 percent of the heart tissue was destroyed by the heart attack in people receiving GIK, compared with 10 percent in those who received the placebo. Although a significant proportion of suspected heart attacks are later determined to be false alarms (23 percent in this study), administering GIK does not appear to cause any harmful effects in such patients.
The research team will follow up with study participants at six and 12 months to evaluate the longer-term benefit of the GIK treatment.
This study was funded by the NIH's National Heart, Lung and Blood Institute.
Mom's voice may improve the health of premature babies
May 10, 2012
When babies are born prematurely, they are thrust into a hospital environment that while highly successful at saving their lives, is not exactly the same as the mother's womb where ideal development occurs. The Neonatal Intensive Care Unit (NICU) is equipped with highly skilled care givers and incubators that regulate temperature and humidity, but Amir Lahav, ScD, PhD, director of the Neonatal Research Lab at Brigham and Women's Hospital (BWH) thought that something was missing -- simulation of the maternal sounds that a baby would hear in the womb. Now, new research conducted by Lahav and colleagues links exposure to an audio recording of mom's heartbeat and her voice to lower incidence of cardiorespiratory events in preterm infants.
This research is published online in the Journal of Maternal-Fetal and Neonatal Medicine.
"Our findings show that there may be a window of opportunity to improve the physiological health of these babies born prematurely using non-pharmalogical treatments, such as auditory stimulation," said Lahav, principal investigator of the study.
Because they are underdeveloped, preterm infants experience high rates of adverse lung and heart events, including apnea (pause in breathing that lasts longer than 20 seconds ) and bradycardia (periods of significantly slow heart rate). Researchers sought to determine whether an auditory intervention could affect the rates of these unwarranted cardiorespiratory events.
To conduct the study, Lahav enrolled fourteen extremely premature infants (born between 26-32 weeks gestation) that were admitted to the NICU at BWH. The infants were assigned to receive an auditory intervention of maternal sound stimulation (MSS), four times per day throughout their NICU hospitalization. Each infant received a personalized MSS-a soundtrack that consisted of his/her own mother's voice and heartbeat. The recording was played into the infant's incubator via a specialized micro audio system developed in Lahav's lab.
Overall, researchers found that cardiorespiratory events occurred at a much lower frequency when the infants were exposed to MSS versus to routine hospital noise and sounds. This effect was statistically significant in infants of 33 weeks gestation or older.
"Our findings are promising in showing that exposure to MSS could help preterm infants in the short-term by reducing cardiorespiratory events. The results also suggest that there is a period of time when the infant's auditory development is most intact that this intervention of MSS could be most impactful," Lahav said. "However, given our small sample size of 14 infants, further research is needed to determine if this intervention could have an impact on the care and health of preterm infants."
This research was funded by support from Christopher Joseph Concha Foundation, Hailey's Hope Foundation, Capita Foundation, Heather on Earth Foundation, John Alden Trust, Learning Disabilities Foundation of America, LifeSpan HealthCare and The Peter and Elizabeth C. Tower Foundation and Phillips Healthcare.
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