Stuff 'n Stuff : Sci-Tech News & Olds -- January 2014

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STUFF 'N STUFF

SCI-TECH NEWS & OLDS

( January 2014 )

( 1 ) Zinc-Oxide nanorod water purification

( 2 ) Household Chemistry & First Aid

( 3 ) Ni45Co5Mn40Sn10 Alloy Converts Heat Directly Into Electricity

( 4 ) Nanoparticle Steam Generation

( 5 ) Oxygen Microbubbles

( 6 ) The Amplituhedron : Quantum Physics Geometry

( 7 ) Popular Mechanics ( November 1936 ) : Gas Extracted from Clover by Inexpensive Process

( 8 ) Modern Mechanics ( December 1932 ) : Steam-Driven Wheels for Cars

( 9 ) Arapaima Bio-Armor

( 10 ) Micro-Super-Microphone

( 11 ) Synthetic Upsalite -- Water Absorbant

( 12 ) Graphene Super-Capacitor

( 13 ) Stanene : 2-D Topological Insulator

( 14 ) V. Kronin : Hepatitis Therapy

( 15 ) Shahid Hossain : Gravitational Energy Converter

( 16 ) Blue Light vs Bacteria

( 17 ) KeriCure vs MRSA

http://phys.org/archive/23-09-2013
September 23, 2013

Spinning CDs to clean sewage water

Audio CDs, all the rage in the '90s, seem increasingly obsolete in a world of MP3 files and iPods, leaving many music lovers with the question of what to do with their extensive compact disk collections.
While you could turn your old disks into a work of avant-garde art, researchers in Taiwan have come up with a more practical application: breaking down sewage. The team will present its new wastewater treatment device at the Optical Society's (OSA) Annual Meeting, Frontiers in Optics <http://www.frontiersinoptics.com> (FiO) 2013, being held Oct. 6-10 in Orlando, Fla.

"Optical disks are cheap, readily available, and very commonly used," says Din Ping Tsai, a physicist at National Taiwan University. Close to 20 billion disks are already manufactured annually, the researchers note, so using old disks for water treatment might even be a way to cut down on waste.

Tsai and his colleagues from National Taiwan University, National Applied Research Laboratories in Taiwan, and the Research Center for Applied Sciences in Taiwan used the large surface area of optical disks as a platform to grow tiny, upright zinc oxide nanorods about a thousandth the width of a human hair. Zinc oxide is an inexpensive semiconductor that can function as a photocatalyst, breaking apart organic molecules like the pollutants in sewage when illuminated with UV light.

While other researchers have experimented with using zinc oxide to degrade organic pollutants, Tsai's team is the first to grow the photocatalyst on an optical disk.

Because the disks are durable and able to spin quickly, contaminated water that drips onto the device spreads out in a thin film that light can easily pass through, speeding up the degradation process.

The Taiwanese team's complete wastewater treatment device is approximately one cubic foot in volume. In addition to the zinc oxide-coated optical disk, the device consists of a UV light source and a system that recirculates the water to further break down the pollutants.

The research team tested the reactor with a solution of methyl orange dye, a model organic compound often used to evaluate the speed of photocatalytic reactions. After treating a half-liter solution of dye for 60 minutes, they found that over 95 percent of the contaminants had been broken down. The device can treat 150 mL of waste water per minute, the researchers say.

The spinning disk reactor is small, consumes little power, and processes contaminated water more efficiently than other photocatalytic wastewater treatment methods, Tsai says. The device could be used on a small scale to clean water contaminated with domestic sewage, urban run-off, industrial effluents, and farm waste.

Going forward, the team is also working on ways to increase the efficiency of the reactor, and Tsai estimates that the system could soon be improved to work even faster, perhaps by creating layers of stacked
disks.

Household Chemistry & First Aid

1. Mayonnaise -- Kills lice, conditions hair.
2. Elmer's Glue - Remove dead skin & blckheads ( paint on & let dry, then peel off
3. Nestea -- Sunburn
4. Sugar -- Tongue burns
5. WD-40 -- Arthritis & insect stings
6. MSG ( Meat Tenderizer ) -- Bee stings
7. Preparation H -- Chigger bites
8. Jello -- Stink foot
9. Cornstarch -- Athletes feet
10. Vicks Vapor Rub -- Toenail fu41gus
11. Kool Aid -- cleans toilets & dishwasher pipes ( Add to the detergent section and run a cycle )
12. Pam -- Remove paint and grease from hands
13. Peanut butter-- Ink stains, CD scratches
14. Vinegar -- Dandruff
15. Milk of Magnesia / Club Soda -- Preserve newspaper -- soak for 20 min. and let dry.
16. Salt -- Wine stains.
17. Peanut Butter -- Remove labels from glassware etc.
18. Efferdent tablets -- Baked on food - fill container with water, soak overnight. Also : Bounce paper softener -- Soak overnight.
19. Colgate toothpaste -- Crayon on walls
20. Listerine -- Dirty grout
21. Toothpaste (Colgate ) -- Crayon marks & Stains on clothes -- Prevents glasses from fogging -- Treat Minor burns
22. Karo Syrup -- Grass stains - Karo Syrup
23. Coca Cola-- Grease Stains - Coca Cola , it will also remove grease stains from the driveway overnight. And : it will take corrosion from car batteries!
24. Borax -- Fleas in your carpet? 20 Mule Team Borax - sprinkle and let stand for 24 hours.
25. Clorox -- To keep flowers fresh longer " Add a little Clorox, or 2 Bayer aspirin, or use 7-up instead of water.

http://www.popsci.com/technology/article/2011-06/new-alloy-can-convert-heat-directly-electricity

New Alloy Can Convert Heat Directly Into Electricity

A new alloy with unique properties can convert heat directly into electricity, according to researchers at the University of Minnesota. The alloy, a multiferroic composite of nickel, cobalt, manganese and tin, can be either non-magnetic and highly magnetic, depending on its temperature.

The new alloy — Ni45Co5Mn40Sn10 — undergoes a reversible phase transformation, in which one type of solid turns into another type of solid when the temperature changes, according to a news release from the University of Minnesota.

Specifically, the alloy goes from being non-magnetic to highly magnetized. The temperature only needs to be raised a small amount for this to happen.

When the warmed alloy is placed near a permanent magnet, like a rare-earth magnet, the alloy's magnetic force increases suddenly and dramatically.

This produces a current in a surrounding coil, according to the researchers, led by aerospace engineering professor Richard James. Watch a piece of the alloy leap over to a permanent magnet in the video clip below.

A process called hysteresis causes some of the heat energy to be lost, but this new alloy has a low hysteresis, the researchers say. Because of this, it could be used to convert waste heat energy into large amounts of electricity.

One obvious use for this material would be in the exhaust pipes of vehicles. Several automakers are already working on heat transfer devices that can convert a car's hot exhaust into usable electricity; General

Motors is using alloys called skutterudites, which are cobalt-arsenide materials doped with rare earths.

In the lab, University of Minnesota researchers show how a new multiferroic material they created begins as a non-magnetic material then suddenly becomes strongly magnetic as the piece of copper below is heated a small amount.

When this happens, it jumps over to a permanent magnet. This demonstration represents the direct conversion of heat to kinetic energy.

A process called hysteresis causes some of the heat energy to be lost, but this new alloy has a low hysteresis, the researchers say. Because of this, it could be used to convert waste heat energy into large amounts of electricity.

One obvious use for this material would be in the exhaust pipes of vehicles. Several automakers are already working on heat transfer devices that can convert a car's hot exhaust into usable electricity; General

Motors is using alloys called skutterudites, which are cobalt-arsenide materials doped with rare earths.

Rare earth magnets are already a necessity in many hybrid car batteries, so heat-capture devices made of the new multiferroic compound could be placed near the magnets.

The material could also be used in power plants or even ocean thermal energy generators, the researchers said.

A paper on the alloy was published in the journal Advanced Energy Materials.

EurekAlert
University of Minnesota

University of Minnesota engineering researchers discover source for generating 'green' electricity

University of Minnesota engineering researchers in the College of Science and Engineering have recently discovered a new alloy material that converts heat directly into electricity. This revolutionary energy conversion method is in the early stages of development, but it could have wide-sweeping impact on creating environmentally friendly electricity from waste heat sources.

Researchers say the material could potentially be used to capture waste heat from a car's exhaust that would heat the material and produce electricity for charging the battery in a hybrid car. Other possible future uses include capturing rejected heat from industrial and power plants or temperature differences in the ocean to create electricity. The research team is looking into possible commercialization of the technology.

"This research is very promising because it presents an entirely new method for energy conversion that's never been done before," said University of Minnesota aerospace engineering and mechanics professor Richard James, who led the research team."It's also the ultimate 'green' way to create electricity because it uses waste heat to create electricity with no carbon dioxide."

To create the material, the research team combined elements at the atomic level to create a new multiferroic alloy, Ni45Co5Mn40Sn10. Multiferroic materials combine unusual elastic, magnetic and electric properties. The alloy Ni45Co5Mn40Sn10 achieves multiferroism by undergoing a highly reversible phase transformation where one solid turns into another solid.

During this phase transformation the alloy undergoes changes in its magnetic properties that are exploited in the energy conversion device.

During a small-scale demonstration in a University of Minnesota lab, the new material created by the researchers begins as a non-magnetic material, then suddenly becomes strongly magnetic when the temperature is raised a small amount. When this happens, the material absorbs heat and spontaneously produces electricity in a surrounding coil. Some of this heat energy is lost in a process called hysteresis. A critical discovery of the team is a systematic way to minimize hysteresis in phase transformations. The team's research was recently published in the first issue of the new scientific journal Advanced Energy Materials.

Watch a short research video of the new material suddenly become magnetic when heated: http://z.umn.edu/conversionvideo.

In addition to Professor James, other members of the research team include University of Minnesota aerospace engineering and mechanics post-doctoral researchers Vijay Srivastava and Kanwal Bhatti, and Ph.D. student Yintao Song. The team is also working with University of Minnesota chemical engineering and materials science professor Christopher Leighton to create a thin film of the material that could be used, for example, to convert some of the waste heat from computers into electricity.

"This research crosses all boundaries of science and engineering," James said. "It includes engineering, physics, materials, chemistry, mathematics and more. It has required all of us within the university's College of Science and Engineering to work together to think in new ways."

http://z.umn.edu/energyalloy
http://onlinelibrary.wiley.com/doi/10.1002/aenm.201000048/abstract
Advanced Energy Materials, Volume 1, Issue 1, pages 97–104, January 1, 2011

The Direct Conversion of Heat to Electricity Using Multiferroic Alloys

Vijay Srivastava, Yintao Song, Kanwal Bhatti1, R. D. James

Abstract

We demonstrate a new method for the direct conversion of heat to electricity using the recently discovered multiferroic alloy, Ni45Co5Mn40Sn101. This alloy undergoes a low hysteresis, reversible martensitic phase transformation from a nonmagnetic martensite phase to a strongly ferromagnetic austenite phase upon heating. When biased by a suitably placed permanent magnet, heating through the phase transformation causes a sudden increase of the magnetic moment to a large value. As a consequence of Faraday’s law of induction, this drives a current in a surrounding circuit. Theory predicts that under optimal conditions the performance compares favorably with the best thermoelectrics. Because of the low hysteresis of the alloy, a promising area of application of this concept appears to be energy conversion at small ?T, suggesting a possible route to the conversion of the vast amounts of energy stored on earth at small temperature difference. We postulate other new methods for the direct conversion of heat to electricity suggested by the underlying theory.

http://www.washingtonpost.com/national/health-science/making-steam-without-boiling-water-thanks-to-nanoparticles/2012/11/19/3d98c4d6-3264-11e2-9cfa-e41bac906cc9_story.html

Making steam without boiling water, thanks to nanoparticles

by

David Brown

It is possible to create steam within seconds by focusing sunlight on nanoparticles mixed into water, according to new research.

That observation, reported Monday by scientists at Rice University in Texas, suggests myriad applications in places that lack electricity or burnable fuels. A sun-powered boiler could desalinate sea water, distill alcohol, sterilize medical equipment and perform other useful tasks.

“We can build a portable, compact steam generator that depends only on sunlight for input. It is something that could really be good in remote or resource-limited locations,” said Naomi J. Halas, an engineer and physicist at Rice who ran the experiment.

Whether the rig she and her colleagues describe would work on an industrial scale is unknown. If it does, it could mark an advance for solar-powered energy more generally.

“We will see how far it can ultimately go. There are certainly places and situations where it would be valuable to generate steam,” said Paul S. Weiss, editor of the American Chemical Society’s journal ACS Nano, which published the paper online in advance of the journal’s December print publication.

The experiment is more evidence that nanoscale devices — in this case, beads one-tenth the diameter of a human hair — behave in ways different from bigger objects.

In the apparatus designed by the Rice team, steam forms in a vessel of water long before the water becomes warm to the touch. It is, in effect, possible to turn a container of water into steam before it gets hot enough to boil.

“There is a disconnect between what happens when we heat a pot of water and what happens when we put nanoparticles in that water,” said Weiss, who is a chemist and director of the California Nanosystems Institute at UCLA.

“This is a novel proposed application of nanoparticles,” said A. Paul Alivisatos, director of the Lawrence Berkeley National Laboratory and a nanotechnology expert. “I think it is very interesting and will stimulate a lot of others to think about the heating of water with sunlight.”

In the Rice experiment, the researchers stirred a small amount of nanoparticles into water and put the mixture into a glass vessel. They then focused sunlight on the mixture with a lens.

The nanoparticles — either carbon or gold-coated silicon dioxide beads — have a diameter shorter than the wavelength of visible light. That allows them to absorb most of a wave of light’s energy. If they had been larger, the particles would have scattered much of the light.

In the focused light, a nanoparticle rapidly becomes hot enough to vaporize the layer of water around it. It then becomes enveloped in a bubble of steam. That, in turn, insulates it from the mass of water that, an instant before the steam formed, was bathing and cooling it.

Insulated in that fashion, the particle heats up further and forms more steam. It eventually becomes buoyant enough to rise. As it floats toward the surface, it hits and merges with other bubbles. At the surface, the nanoparticles-in-bubbles release their steam into the air. They then sink back toward the bottom of the vessel. When they encounter the focused light, the process begins again. All of this occurs within seconds.

In all, about 80 percent of the light energy a nanoparticle absorbs goes into making steam, and only 20 percent is “lost” in heating the water.

This is far different from creating steam in a tea kettle. There, all the water must reach boiling temperature before an appreciable number of water molecules fly into the air as steam.

The phenomenon is such that it is possible to put the vessel containing the water-and-nanoparticle soup into an ice bath, focus light on it and make steam.

“It shows you could make steam in an arctic environment,” Halas said. “There might be some interesting applications there.”

The apparatus can also separate mixtures of water and other substances into their components — the process known as distillation — more completely than is usually possible. For example, with normal distillation of a water-and-alcohol mixture, it isn’t possible to get more than 95 percent pure alcohol. Using nanoparticles to create the steam, 99 percent alcohol can be collected.

Halas said the nanoparticles are not expensive to make and, because they act essentially as catalysts, are not used up. A nanoparticle steam generator could be used over and over. And, as James Watt and other 18th-century inventors showed, if you can generate steam easily, you can create an industrial revolution.

The research is being funded in part by the Bill & Melinda Gates Foundation in the hope it might prove useful to developing countries.

Halas and her team recently spent three days in Seattle demonstrating the apparatus.

“Luckily,” she said, “it was sunny.”

http://www.sciencedaily.com/releases/2012/06/120627142512.htm

Injecting Life-Saving Oxygen Into a Vein

June 27, 2012 — Patients unable to breathe because of acute lung failure or an obstructed airway need another way to get oxygen to their blood -- and fast -- to avoid cardiac arrest and brain injury. A team led by
researchers at Boston Children's Hospital has designed tiny, gas-filled microparticles that can be injected directly into the bloodstream to quickly oxygenate the blood.

The microparticles consist of a single layer of lipids (fatty molecules) that surround a tiny pocket of oxygen gas, and are delivered in a liquid solution. In a cover article in the June 27 issue of Science Translational
Medicine, John Kheir, MD, of the Department of Cardiology at Boston Children's Hospital, and colleagues report that an infusion of these microparticles into animals with low blood oxygen levels restored blood oxygen saturation to near-normal levels, within seconds.

When the trachea was completely blocked -- a more dangerous "real world" scenario -- the infusion kept the animals alive for 15 minutes without a single breath, and reduced the incidence of cardiac arrest and organ
injury.

The microparticle solutions are portable and could stabilize patients in emergency situations, buying time for paramedics, emergency clinicians or intensive care clinicians to more safely place a breathing tube or perform other life-saving therapies, says Kheir.

"This is a short-term oxygen substitute -- a way to safely inject oxygen gas to support patients during a critical few minutes," he says.

"Eventually, this could be stored in syringes on every code cart in a hospital, ambulance or transport helicopter to help stabilize patients who are having difficulty breathing."

The microparticles would likely only be administered for a short time, between 15 and 30 minutes, because they are carried in fluid that would overload the blood if used for longer periods, Kheir says.

Kheir also notes that the particles are different from blood substitutes, which carry oxygen but are not useful when the lungs are unable to oxygenate them. Instead, the microparticles are designed for situations in which the lungs are completely incapacitated.

Kheir began investigating the idea of injectable oxygen in 2006, after caring for a little girl who sustained a severe brain injury resulting from a severe pneumonia that caused bleeding into her lungs and severely low oxygen levels. Despite the team's best efforts, she died before they could place her on a heart-lung machine. Frustrated by this, Kheir formed a team to search for another way to deliver oxygen.

"Some of the most convincing experiments were the early ones," he says. "We drew each other's blood, mixed it in a test tube with the microparticles, and watched blue blood turn immediately red, right before our eyes."

Over the years, Kheir and his team have tested various concentrations and sizes of the microparticles to optimize their effectiveness and to make them safe for injection. "The effort was truly multidisciplinary," says Kheir. "It took chemical engineers, particle scientists and medical doctors to get the mix just right."

In the studies reported in the paper, they used a device called a sonicator, which uses high-intensity sound waves to mix the oxygen and lipids together. The process traps oxygen gas inside particles averaging 2 to 4 micrometers in size (not visible without a microscope). The resulting solution, with oxygen gas making up 70 percent of the volume, mixed efficiently with human blood.

"One of the keys to the success of the project was the ability to administer a concentrated amount of oxygen gas in a small amount of liquid," Kheir says. "The suspension carries three to four times the oxygen content of our own red blood cells."

Intravenous administration of oxygen gas was tried in the early 1900s, but these attempts failed to oxygenate the blood and often caused dangerous gas embolisms.

"We have engineered around this problem by packaging the gas into small, deformable particles," Kheir explains. "They dramatically increase the surface area for gas exchange and are able to squeeze through capillaries where free gas would get stuck."

The study was funded by three awards from the Technology Development Fund at Boston Children's Hospital Boston and a U.S. Department of Defense Basic Research Award to Kheir.

Reference:

John N. Kheir, Laurie A. Scharp, Mark A. Borden, Edward J. Swanson, Andrew Loxley, James H. Reese, Katherine J. Black, Luis A. Velazquez, Lindsay M. Thomson, Brian K. Walsh, Kathryn E. Mullen, Dionne A. Graham, Michael W. Lawlor, Carlo Brugnara, David C. Bell, and Francis X. McGowan, Jr. Oxygen Gas–Filled Microparticles Provide Intravenous Oxygen Delivery. Science Translational Medicine, 27 June 2012 DOI: 10.1126/scitranslmed.3003679

MICROBUBBLES AND METHODS FOR OXYGEN DELIVERY
US8481077

John KHEIR, et al

Compositions containing a carrier and microbubbles encapsulating one or more gases, preferably oxygen, and methods for making and using the compositions are described herein. The microbubbles contain a lipid envelope. The compositions may be administered to a patient to quickly deliver large amounts of oxygen to the patient's blood supply or directly to a tissue in need of oxygen. The compositions may be administered via injection or as a continuous infusion. The compositions contain a concentrated microbubble suspension, where the suspension contains at least 40 mL oxygen/dL suspension. The microbubbles are preferably less than 20 microns in diameter, more preferably less than 15 microns in diameter. The microbubbles described herein may be administered to a patient in an effective amount to increase in oxygen concentration in the patient's blood, and/or one or more tissues or organs.

CROSS-REFERENCE TO RELATED APPLICATIONS

FIELD OF THE INVENTION

[0003] This present invention relates to compositions and methods for gas perfusion of tissues, and especially delivery of an effective amount of oxygen to a patient to alleviate or prevent ischemic injury.

BACKGROUND OF THE INVENTION

[0004] Every human cell requires a constant supply of oxygen to maintain cellular structure and homeostasis. This supply is primarily provided by hemoglobin, which carries inspired oxygen from the pulmonary capillaries to the tissues. In cases where a patient's lungs are unable to transfer adequate amounts of oxygen to circulating erythrocytes, severe hypoxia results and can quickly lead to severe organ injury and death.

[0005] Restoration of blood oxygen tension is paramount to resuscitation of the majority of pathophysiologic states. Some clinical states, such as lung injury, airway obstruction, and intracardiac mixing, exhibit hypoxemia and desaturation refractory to medical efforts to restore levels of oxygen saturation sufficient to limit ischemic injury. Ischemic injury may take place within minutes or seconds of insufficient oxygen delivery.

In these conditions, low oxygen tension can result in end-organ dysfunction, failure, and mortality. The ability to augment oxygenation quickly and non-invasively would have dramatic implications on the morbidity and mortality from acute hypoxia, in addition to a number of other clinical situations.

[0006] Conventional attempts to restore oxygen levels in patients utilize supportive therapy of the patient's respiratory system, most commonly by way of mechanical ventilation. However, patients with lung injury, comprising a significant population of intensive care unit patients, have difficulty exchanging oxygen across a damaged alveolar unit. This requires clinicians to increase ventilator pressures, often causing further lung injury and systemic inflammation. Significant morbidity and mortality has been associated with ventilator induced lung injury, and barotrauma to the lungs is often necessitated by inadequate systemic oxygen delivery. The ability to non-invasively supplement even small percentages of oxygen delivery may significantly reduce the morbidity of mechanical ventilation.

[0007] Furthermore, emergency efforts to deliver oxygen to a patient are often inadequate and/or require too long to take effect, either due to lack of an adequate airway or overwhelming lung injury. This results in irreversible injury to the brain and other organs. Initiation of rescue therapy in these patients is burdensome and time consuming, and is available only at a limited number of specialized health care centers.

There remains a need to quickly deliver oxygen directly to the blood of patients, thereby preventing or minimizing irreversible injury due to hypoxemia.

[0008] Therefore it is an object of the invention to provide improved methods for delivering oxygen to patients, tissues or organs.

[0009] It is yet a further object of the invention to provide improved compositions for delivering oxygen to patients, tissues or organs.

[0010] It is a still further object of the invention to provide improved methods for producing compositions for delivering oxygen to patients, tissues or organs.

SUMMARY OF THE INVENTION

[0011] Compositions containing a carrier and microbubbles encapsulating one or more gases, preferably oxygen, and methods for making and using the compositions are described herein. The microbubbles contain a lipid envelope formed of at least one base lipid and at least one emulsifying agent. The compositions may be administered to a patient to quickly deliver large amounts of oxygen to the patient's blood supply or directly to a tissue in need of oxygen. The compositions may be administered via injection or as a continuous infusion. The compositions contain a concentrated microbubble suspension, where the suspension contains at least 40 mL oxygen/dL suspension. The microbubbles are preferably less than 20 microns in diameter, more preferably less than 15 microns in diameter. The microbubbles described herein may be administered to a patient in an effective amount to increase the oxygen concentration in the patient's blood, and/or one or more tissues or organs, preferably in an amount effective to prevent or alleviate ischemic injury. The microbubbles may be administered alone or in combination with other treatments as an adjective therapy.

simonsfoundation.org
September 17, 2013

A Jewel at the Heart of Quantum Physics

by

Natalie Wolchover

Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality.

“This is completely new and very much simpler than anything that has been done before,” said Andrew Hodges, a mathematical physicist at Oxford University who has been following the work.

The revelation that particle interactions, the most basic events in nature, may be consequences of geometry significantly advances a decades-long effort to reformulate quantum field theory, the body of laws describing elementary particles and their interactions. Interactions that were previously calculated with mathematical formulas thousands of terms long can now be described by computing the volume of the corresponding jewel-like “amplituhedron,” which yields an equivalent one-term expression.

“The degree of efficiency is mind-boggling,” said Jacob Bourjaily, a theoretical physicist at Harvard University and one of the researchers who developed the new idea. “You can easily do, on paper, computations that were infeasible even with a computer before.”

The new geometric version of quantum field theory could also facilitate the search for a theory of quantum gravity that would seamlessly connect the large- and small-scale pictures of the universe. Attempts thus far to incorporate gravity into the laws of physics at the quantum scale have run up against nonsensical infinities and deep paradoxes. The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity.

“Both are hard-wired in the usual way we think about things,” said Nima Arkani-Hamed, a professor of physics at the Institute for Advanced Study in Princeton, N.J., and the lead author of the new work, which he is presenting in talks and in a forthcoming paper. “Both are suspect.”

Locality is the notion that particles can interact only from adjoining positions in space and time. And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one. The concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature.

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions.

The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.

“It’s a better formulation that makes you think about everything in a completely different way,” said David Skinner, a theoretical physicist at Cambridge University.

The amplituhedron itself does not describe gravity. But Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time.

Because “we know that ultimately, we need to find a theory that doesn’t have” unitarity and locality, Bourjaily said, “it’s a starting point to ultimately describing a quantum theory of gravity.”

Clunky Machinery

The amplituhedron looks like an intricate, multifaceted jewel in higher dimensions. Encoded in its volume are the most basic features of reality that can be calculated, “scattering amplitudes,” which represent the likelihood that a certain set of particles will turn into certain other particles upon colliding. These numbers are what particle physicists calculate and test to high precision at particle accelerators like the Large Hadron Collider in Switzerland.

The iconic 20th century physicist Richard Feynman invented a method for calculating probabilities of particle interactions using depictions of all the different ways an interaction could occur. Examples of “Feynman diagrams” were included on a 2005 postage stamp honoring Feynman.

United States Postal Service

The iconic 20th century physicist Richard Feynman invented a method for calculating probabilities of particle interactions using depictions of all the different ways an interaction could occur. Examples of “Feynman diagrams” were included on a 2005 postage stamp honoring Feynman.

The 60-year-old method for calculating scattering amplitudes — a major innovation at the time — was pioneered by the Nobel Prize-winning physicist Richard Feynman. He sketched line drawings of all the ways a scattering process could occur and then summed the likelihoods of the different drawings. The simplest Feynman diagrams look like trees: The particles involved in a collision come together like roots, and the particles that result shoot out like branches. More complicated diagrams have loops, where colliding particles turn into unobservable “virtual particles” that interact with each other before branching out as real final products. There are diagrams with one loop, two loops, three loops and so on — increasingly baroque iterations of the scattering process that contribute progressively less to its total amplitude. Virtual particles are never observed in nature, but they were considered mathematically necessary for unitarity — the requirement that probabilities sum to one.

“The number of Feynman diagrams is so explosively large that even computations of really simple processes weren’t done until the age of computers,” Bourjaily said. A seemingly simple event, such as two subatomic particles called gluons colliding to produce four less energetic gluons (which happens billions of times a second during collisions at the Large Hadron Collider), involves 220 diagrams, which collectively contribute thousands of terms to the calculation of the scattering amplitude.

In 1986, it became apparent that Feynman’s apparatus was a Rube Goldberg machine.

To prepare for the construction of the Superconducting Super Collider in Texas (a project that was later canceled), theorists wanted to calculate the scattering amplitudes of known particle interactions to establish a background against which interesting or exotic signals would stand out.

But even 2-gluon to 4-gluon processes were so complex, a group of physicists had written two years earlier, “that they may not be evaluated in the foreseeable future.”

Stephen Parke and Tommy Taylor, theorists at Fermi National Accelerator Laboratory in Illinois, took that statement as a challenge. Using a few mathematical tricks, they managed to simplify the 2-gluon to 4-gluon amplitude calculation from several billion terms to a 9-page-long formula, which a 1980s supercomputer could handle. Then, based on a pattern they observed in the scattering amplitudes of other gluon interactions, Parke and Taylor guessed a simple one-term expression for the amplitude. It was, the computer verified, equivalent to the 9-page formula. In other words, the traditional machinery of quantum field theory, involving hundreds of

Feynman diagrams worth thousands of mathematical terms, was obfuscating something much simpler. As Bourjaily put it: “Why are you summing up millions of things when the answer is just one function?”

“We knew at the time that we had an important result,” Parke said. “We knew it instantly. But what to do with it?”

The Amplituhedron

The message of Parke and Taylor’s single-term result took decades to interpret. “That one-term, beautiful little function was like a beacon for the next 30 years,” Bourjaily said. It “really started this revolution.”
Twistor diagrams depicting an interaction between six gluons, in the cases where two (left) and four (right) of the particles have negative helicity, a property similar to spin. The diagrams can be used to derive a simple formula for the 6-gluon scattering amplitude.

Twistor diagrams depicting an interaction between six gluons, in the cases where two (left) and four (right) of the particles have negative helicity, a property similar to spin. The diagrams can be used to derive a simple formula for the 6-gluon scattering amplitude.

In the mid-2000s, more patterns emerged in the scattering amplitudes of particle interactions, repeatedly hinting at an underlying, coherent mathematical structure behind quantum field theory. Most important was a set of formulas called the BCFW recursion relations, named for Ruth

Britto, Freddy Cachazo, Bo Feng and Edward Witten. Instead of describing scattering processes in terms of familiar variables like position and time and depicting them in thousands of Feynman diagrams, the BCFW relations are best couched in terms of strange variables called “twistors,” and particle interactions can be captured in a handful of associated twistor diagrams. The relations gained rapid adoption as tools for computing scattering amplitudes relevant to experiments, such as collisions at the Large Hadron Collider. But their simplicity was mysterious.

“The terms in these BCFW relations were coming from a different world, and we wanted to understand what that world was,” Arkani-Hamed said. “That’s what drew me into the subject five years ago.”

With the help of leading mathematicians such as Pierre Deligne, Arkani-Hamed and his collaborators discovered that the recursion relations and associated twistor diagrams corresponded to a well-known geometric object.

In fact, as detailed in a paper posted to arXiv.org in December by Arkani-Hamed, Bourjaily, Cachazo, Alexander Goncharov, Alexander Postnikov and Jaroslav Trnka, the twistor diagrams gave instructions for calculating the volume of pieces of this object, called the positive Grassmannian.

Named for Hermann Grassmann, a 19th-century German linguist and mathematician who studied its properties, “the positive Grassmannian is the slightly more grown-up cousin of the inside of a triangle,” Arkani-Hamed explained. Just as the inside of a triangle is a region in a two-dimensional space bounded by intersecting lines, the simplest case of the positive Grassmannian is a region in an N-dimensional space bounded by intersecting planes. (N is the number of particles involved in a scattering process.)

It was a geometric representation of real particle data, such as the likelihood that two colliding gluons will turn into four gluons. But something was still missing.

The physicists hoped that the amplitude of a scattering process would emerge purely and inevitably from geometry, but locality and unitarity were dictating which pieces of the positive Grassmannian to add together to get it. They wondered whether the amplitude was “the answer to some particular mathematical question,” said Trnka, a post-doctoral researcher at the California Institute of Technology. “And it is,” he said.
A sketch of the amplituhedron representing an 8-gluon particle interaction. Using Feynman diagrams, the same calculation would take roughly 500 pages of algebra.

A sketch of the amplituhedron representing an 8-gluon particle interaction. Using Feynman diagrams, the same calculation would take roughly 500 pages of algebra.

Arkani-Hamed and Trnka discovered that the scattering amplitude equals the volume of a brand-new mathematical object — the amplituhedron. The details of a particular scattering process dictate the dimensionality and facets of the corresponding amplituhedron. The pieces of the positive Grassmannian that were being calculated with twistor diagrams and then added together by hand were building blocks that fit together inside this jewel, just as triangles fit together to form a polygon.

Like the twistor diagrams, the Feynman diagrams are another way of computing the volume of the amplituhedron piece by piece, but they are much less efficient. “They are local and unitary in space-time, but they are not necessarily very convenient or well-adapted to the shape of this jewel itself,” Skinner said. “Using Feynman diagrams is like taking a Ming vase and smashing it on the floor.”

Arkani-Hamed and Trnka have been able to calculate the volume of the amplituhedron directly in some cases, without using twistor diagrams to compute the volumes of its pieces. They have also found a “master amplituhedron” with an infinite number of facets, analogous to a circle in 2-D, which has an infinite number of sides. Its volume represents, in theory, the total amplitude of all physical processes. Lower-dimensional amplituhedra, which correspond to interactions between finite numbers of particles, live on the faces of this master structure.

“They are very powerful calculational techniques, but they are also incredibly suggestive,” Skinner said. “They suggest that thinking in terms of space-time was not the right way of going about this.”

Quest for Quantum Gravity

The seemingly irreconcilable conflict between gravity and quantum field theory enters crisis mode in black holes. Black holes pack a huge amount of mass into an extremely small space, making gravity a major player at the quantum scale, where it can usually be ignored. Inevitably, either locality or unitarity is the source of the conflict.

Puzzling Thoughts

Locality and unitarity are the central pillars of quantum field theory, but as the following thought experiments show, both break down in certain situations involving gravity. This suggests physics should be formulated without either principle.

Locality says that particles interact at points in space-time. But suppose you want to inspect space-time very closely. Probing smaller and smaller distance scales requires ever higher energies, but at a certain scale, called the Planck length, the picture gets blurry: So much energy must be concentrated into such a small region that the energy collapses the region into a black hole, making it impossible to inspect. “There’s no way of measuring space and time separations once they are smaller than the Planck length,” said Arkani-Hamed. “So we imagine space-time is a continuous thing, but because it’s impossible to talk sharply about that thing, then that suggests it must not be fundamental — it must be emergent.”

Unitarity says the quantum mechanical probabilities of all possible outcomes of a particle interaction must sum to one. To prove it, one would have to observe the same interaction over and over and count the frequencies of the different outcomes. Doing this to perfect accuracy would require an infinite number of observations using an infinitely large measuring apparatus, but the latter would again cause gravitational collapse into a black hole. In finite regions of the universe, unitarity can therefore only be approximately known.

“We have indications that both ideas have got to go,” Arkani-Hamed said.

“They can’t be fundamental features of the next description,” such as a theory of quantum gravity.

String theory, a framework that treats particles as invisibly small, vibrating strings, is one candidate for a theory of quantum gravity that seems to hold up in black hole situations, but its relationship to reality is unproven — or at least confusing. Recently, a strange duality has been found between string theory and quantum field theory, indicating that the former (which includes gravity) is mathematically equivalent to the latter (which does not) when the two theories describe the same event as if it is taking place in different numbers of dimensions. No one knows quite what to make of this discovery. But the new amplituhedron research suggests space-time, and therefore dimensions, may be illusory anyway.

“We can’t rely on the usual familiar quantum mechanical space-time pictures of describing physics,” Arkani-Hamed said. “We have to learn new ways of talking about it. This work is a baby step in that direction.”

Even without unitarity and locality, the amplituhedron formulation of quantum field theory does not yet incorporate gravity. But researchers are working on it. They say scattering processes that include gravity particles may be possible to describe with the amplituhedron, or with a similar geometric object. “It might be closely related but slightly different and harder to find,” Skinner said.

Nima Arkani-Hamed, a professor at the Institute for Advanced Study, and his former student and co-author Jaroslav Trnka, who finished his Ph.D. at Princeton University in July and is now a post-doctoral researcher at the California Institute of Technology.

Physicists must also prove that the new geometric formulation applies to the exact particles that are known to exist in the universe, rather than to the idealized quantum field theory they used to develop it, called maximally supersymmetric Yang-Mills theory. This model, which includes a “superpartner” particle for every known particle and treats space-time as flat, “just happens to be the simplest test case for these new tools,”

Bourjaily said. “The way to generalize these new tools to [other] theories is understood.”

Beyond making calculations easier or possibly leading the way to quantum

gravity, the discovery of the amplituhedron could cause an even more profound shift, Arkani-Hamed said. That is, giving up space and time as fundamental constituents of nature and figuring out how the Big Bang and cosmological evolution of the universe arose out of pure geometry.

“In a sense, we would see that change arises from the structure of the object,” he said. “But it’s not from the object changing. The object is basically timeless.”

While more work is needed, many theoretical physicists are paying close attention to the new ideas.

The work is “very unexpected from several points of view,” said Witten, a theoretical physicist at the Institute for Advanced Study. “The field is still developing very fast, and it is difficult to guess what will happen or what the lessons will turn out to be.”

Popular Mechanics ( November 1936 )

Gas Extracted from Clover by Inexpensive Process

Modern Mechanics ( December 1932 )

Steam-Driven Wheels for Cars

http://www.telegraph.co.uk/science/science-news/10381383/Fish-that-can-survive-piranha-bites-inspire-new-types-of-body-armour.html
16 Oct 2013

Fish that can survive piranha bites inspire new types of body armour

By Richard Gray, Science Correspondent

Fish that live in piranha infested waters have evolved scales to protect them from the predator's fearsome teeth and are being used to develop new types of body armour The protective scales of Arapaima gigas are capable of absorbing the impact of a bite by flexing and twisting to spread the stress created by the teeth.

They are fearsome predators that have been exploited by James Bond villains and horror movie directors to strike fear into swimmers.

But while piranhas have the reputation for being able to strip their victims to the bone in minutes, some species of fish that live alongside them have evolved ways of avoiding their sharp teeth and powerful jaws.

Scientists have found that a freshwater fish called Arapaima gigas, which lives in the Amazon River in Brazil, has developed tough armour that protects them from piranha bites.

Now these fish are being used to help develop new types of body armour to protect people against bullets and knife attacks.

Researchers found that the protective scales of Arapaima gigas, are capable of absorbing the impact of a piranha bite by flexing and twisting to spread the stress created by the teeth.

Yet the scales are also hard enough to cause the teeth of the piranha to fracture, meaning Arapaima rarely fall prey to the veracious Amazon predators.

Dr Robert Ritchie, chair of material sciences at the University of California Berkeley and who led the research, described the scales as having a structure like twisted plywood that deforms under pressure.

The outer layers are hardened, making them resistant to penetration by the teeth while an overlapping, corrugated structure helps share the strain of the bite.

He said they are now attempting to mimic the structure to create new types of body armour of shields.

He said: "Without such scales the Arapaima as a very large fish would be easy prey for piranhas.

"The fish scale is designed ideally for armour, which has a hard external layer to resist penetration by a bullet and a flexible and tough inner layer to accommodate the excessive deformation without fracturing the armour.

"What we are trying to do is to create composite ceramics with the hard external layer and some flexible foundation to use as a shield or armour."

Arapaima are the largest fish found in South American rivers, growing up to six feet seven inches long and weighing around 220lbs.

The researchers, whose work is published in the journal Nature Communications, used X-rays to determine the structure of the layers, or lamella, that make up the scales that coat the fish's body.

Each layer is made from the protein collagen, which is also found in hair and nails. The upper layers have a high mineral content, making them hard but brittle.

Lower layers have lower mineral content meaning they are more flexible.

These are layered on top of each other in a twisting pattern, which the researcher described as being a Bouligand-like arrangement.

When they are put under strain they rotate further, as the collagen fibres stretch and slide.

Previous work has shown the scales can resisting pressures of up to 12 gigapascals, or 1.7 million pounds per square inch.

To give some idea of how large this is, commercial diamonds are created using pressures of 18 gigapascals.

Dr Ritchie said: “The dermal scales of the Arapaima fish are a prime example of how the structural arrangement of simple biological components can create armour with the capacity to be tough yet penetration resistant.

“The ability of the A. gigas’ outer dermal layer to resist predatory attacks derives from its sophisticated structure from the nano- to macro-length-scales.

“The outer mineral layer gives the scale hardness and penetration resistance whereas the overlapping of the scales and the corrugated outer surface of the mineral layer allow the scales to bend transferring tensile stress to the inner lower-mineralised lamellae.”

Piranha themselves have one of the most powerful bites for their size – rows of interlocking triangular teeth are powered by huge muscles that make up most of the fish's head.

Despite their reputation, attacks on humans are relatively rare. there are an estimated 30 different species of piranha with most measuring between five inches to 10 inches in length.

Rather than being ferocious predators that hunt in schools they are mainly timid fish.

However, the red bellied piranha are known to attack in this way when water levels are low and they have been starved of food.

Scientists have previously pitted piranha teeth against Arapaima scales by mounting them on rubber and pressing the teeth into them with an industrial hole puncher.

The teeth cracked before they reached the rubber underneath.

http://www.nature.com/ncomms/2013/131015/ncomms3634/full/ncomms3634.html
Nature Communications 4, Article number: 2634
15 October 2013

Mechanical adaptability of the Bouligand-type structure in natural dermal armour

Elizabeth A. Zimmermann, et al.

Abstract

Arapaima gigas, a fresh water fish found in the Amazon Basin, resist predation by piranhas through the strength and toughness of their scales, which act as natural dermal armour. Arapaima scales consist of a hard, mineralized outer shell surrounding a more ductile core. This core region is composed of aligned mineralized collagen fibrils arranged in distinct lamellae. Here we show how the Bouligand-type (twisted plywood) arrangement of collagen fibril lamellae has a key role in developing their unique protective properties, by using in situ synchrotron small-angle X-ray scattering during mechanical tensile tests to observe deformation mechanisms in the fibrils. Specifically, the Bouligand-type structure allows the lamellae to reorient in response to the loading environment; remarkably, most lamellae reorient towards the tensile axis and deform in tension through stretching/sliding mechanisms, whereas other lamellae sympathetically rotate away from the tensile axis and compress, thereby enhancing the scale’s ductility and toughness to prevent fracture.

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Zimmermann, E. A., Barth, H. D. & Ritchie, R. O. On the multiscale origins of fracture resistance in human bone and its biological degradation. JOM 64, 486–493 (2012).

Launey, M. E., Buehler, M. J. & Ritchie, R. O. On the Mechanistic Origins of Toughness in Bone. Ann. Rev. Mater. Res. 40, 25–53 (2010).

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Browning, A., Ortiz, C. & Boyce, M. C. Mechanics of composite elasmoid fish scale assemblies and their bioinspired analogues. J. Mech. Behav. Biomed. 19, 75–86 (2013).

Yang, W. et al. Natural flexible dermal armor. Adv. Mater. 25, 31–48 (2013).

Bruet, B. J. F., Song, J. H., Boyce, M. C. & Ortiz, C. Materials design principles of ancient fish armour. Nat. Mater. 7, 748–756 (2008).

Zhu, D. et al. Structure and mechanical performance of a ‘modern’ fish scale. Adv. Eng. Mater. 14, B185–B194 (2012).

Lin, Y. S., Wei, C. T., Olevsky, E. A. & Meyers, M. A. Mechanical properties and the laminate structure of Arapaima gigas scales. J. Mech. Behav. Biomed. 4, 1145–1156 (2011).

Torres, F. G., Troncoso, O. P., Nakamatsu, J., Grande, C. J. & Gomez, C. M. Characterization of the nanocomposite laminate structure occurring in fish scales from Arapaima Gigas. Mater. Sci. Eng. C 28, 1276–1283 (2008).

Meyers, M. A., Lin, Y. S., Olevsky, E. A. & Chen, P. Y. Battle in the Amazon: Arapaima versus Piranha. Adv. Eng. Mater. 14, B279–B288 (2012).

Bouligand, Y. Twisted fibrous arrangements in biological-materials and cholesteric mesophases. Tissue Cell 4, 189–217 (1972).

Bigi, A. et al. Twisted plywood pattern of collagen fibrils in teleost scales: an X-ray diffraction investigation. J. Struct. Biol. 136, 137–143 (2001).

Gupta, H. S. et al. Cooperative deformation of mineral and collagen in bone at the nanoscale. Proc. Natl Acad. Sci. USA 103, 17741–17746 (2006).Krauss, S. et al. Inhomogeneous fibril stretching in antler starts after macroscopic yielding: Indication for a nanoscale toughening mechanism. Bone 44, 1105–1110 (2009).Sasaki, N. & Odajima, S. Stress-strain curve and young's modulus of a collagen molecule as determined by the X-ray diffraction technique. J. Biomech. 29, 655–658 (1996).Zimmermann, E. A. et al. Age-related changes in the plasticity and toughness of human cortical bone at multiple length scales. Proc. Natl Acad. Sci. USA 108, 14416–14421 (2011).Gautieri, A., Pate, M. I., Vesentini, S., Redaelli, A. & Buehler, M. J. Hydration and distance dependence of intermolecular shearing between collagen molecules in a model microfibril. J. Biomech. 45, 2079–2083 (2012).

newscientist.com
Magazine issue 2936
26 September 2013

Matchstick-sized sensor can record your private chats

by

Jim Nash


A sensor previously used for military operations can now be tuned to secretly locate and record any single conversation on a busy street

EVERYONE knows that to have a private chat in the NSA era, you go outdoors. Phones, the internet, email and your office can all be compromised with ease. But soon even that whispered conversation in the park may no longer be safe from prying ears.

Carrying out covert audio surveillance along a city street or a wooded path, say, currently requires parabolic microphones, which look like large, clear salad bowls and need a direct, unobstructed view of the subject. Hardly 007 territory.

Now, a Dutch acoustics firm, Microflown Technologies, has developed a matchstick-sized sensor that can pinpoint and record a target's conversations from a distance.

Known as an acoustic vector sensor, Microflown's sensor measures the movement of air, disturbed by sound waves, to almost instantly locate where a sound originated. It can then identify the noise and, if required, transmit it live to waiting ears.

Conventional microphones work when sound waves make a diaphragm move, creating an electrical signal. Microflown's sensor has no moving parts. It consists of two parallel platinum strips, each just 200 nanometres deep, that are heated to 200 °C. Air molecules flowing across the strips cause temperature differences between the pair. Microflown's software counts the air molecules that pass through the gap between the strips to gauge sound intensity: the more air molecules in a sound wave, the louder the sound.

At the same time, it analyses the temperature change in the strips to work out the movement of the air and calculate the coordinates of whatever generated the sound.

Until now, the military has been using an early version of the sensor to pinpoint enemy planes and rockets. A single sensor can track and identify multiple distant jets, mortar rounds and sniper rifles in any environment.

Earlier this year, Microflown's researchers discovered by chance that the device can hear, record or stream an ordinary conversation from as far away as 20 metres, says Hans-Elias de Bree, the firm's co-founder.

Signal-processing software filters out unwanted noise like wind or traffic commotion. Work is now underway to increase the range.

Given a battery and a tiny antenna, the sensor could be attached to traffic lights, a shrub or park bench. Such systems can be teamed with surveillance cameras. Detecting a shout or a gunshot, the sensor can direct the camera to the precise location of trouble, the way our ears work with our eyes. It can then start recording everything that is being said in that location.

A number of countries are now testing the matchstick sensor attached to drones and crewed vehicles, says de Bree. He foresees governments placing them on small dirigibles that tail suspects or hover over political rallies.

"Not only could this work, it has worked," says Ron Barrett-Gonzalez at the University of Kansas. He has helped boost the sensor's range by 28 per cent to more than 25 metres. It will be possible to record a parade of people on a busy sidewalk all day using a camera and acoustic sensor, and tune into each conversation or voice, live or via stored files, he says.

Security technologist Bruce Schneier says this new capability is unwelcome – particularly given the recent claims about the NSA's success at tapping into our private lives. "It's not just this one technology that's the problem," Schneier says. "It's the mic plus the drones, plus the signal processing, plus voice recognition."

This article appeared in print under the headline "The tiny spy"

Listening to the skies

A tiny sensor that can eavesdrop on private conversations is not just useful to big brother (see main story). Ecuador is using sensors that measure airflow for something other than spycraft. The government is putting sensors in, around and near airports to form an acoustic air-traffic control system. The sensors pinpoint a plane's direction by analysing the air movement. Software can tell if a plane is climbing, descending or straining with cargo.

While geographical features such as mountains can play havoc with radar returns, the comparative simplicity of passive listening can make Microflown's sensors less easy to fool. They are also much cheaper than radar equipment.

http://www.independent.co.uk/
16 August 2013

Scientists accidentally make ‘impossible material’ Upsalite - the world’s most efficient water absorber

Human error solves problem of how to produce world’s most efficient water absorber more cheaply

by

Tom Bawden

It is so difficult to make that the researchers who first discovered it called it the “impossible material”.

Now a century later, a team of Swedish scientists have done the impossible by producing the substance known as Upsalite by accident – after leaving their equipment running over the weekend.

The breakthrough has far-reaching commercial applications, as Upsalite (named after the University of Uppsala, where the scientists are based) is the world’s most efficient water absorber, with potential to be used for the removal of moisture in drug creation and high-tech electronics to cleaning up huge oil spills.

A single gram of this elusive white, dry, powdered form of magnesium carbonate (MgCO3) has an extraordinarily-large surface area of 800 square meters thanks to numerous minuscule pores, each one a million times smaller than the width of a human hair.

“Upsalite absorbs more water and low relative humidities than the best materials presently available and can be regenerated with less energy consumption than is used in similar processes today,” said Maria Stromme, professor of nanotechnology at Uppsala University.

“This, together with other unique properties of the discovered impossible material, is expected to pave the way for new sustainable products in a number of industrial applications,” she said.

Other uses include ice hockey rinks, warehouses, the collection of toxic waste or chemical spills and odour control. MgCO3 is also about as dry as a material can get, a property which, combined with a huge relative surface area that is inundated with pocket pores, makes it the world’s best mop. The only problem is that, until now, this absorbent form of magnesium carbonate could only be produced by a process that is so expensive and involves so much heat that it wasn’t remotely feasible to use it. While other members of the so-called “disordered carbonates” family could be produced more cheaply and simply – by bubbling carbon dioxide through a mixture containing alcohol – a group of German researchers claimed in 1908 that this method couldn’t be used to make dry MgCO3. And so they dubbed it the “impossible material”.The irony is that although the Uppsala team had been trying to create the impossible material, they had been going about it the wrong way.

“A Thursday afternoon in 2011, we slightly changed the synthesis parameters of the earlier employed unsuccessful attempts, and by mistake left the material in the reaction chamber over the weekend. Back at work on Monday morning we discovered that a rigid gel had formed and after drying this gel we started to get excited,” says Johan Gomez de la Torre.

The unwitting solution still involved bubbling the Co2 through the alcohol mixture, but at three times normal atmospheric pressure. A year of detailed analysis and experimental fine tuning followed, during which time it was discovered that when heated to 70C the resulting gel solidifies and collapses into a white and coarse powder.

“It became clear that we had indeed synthesised the material that previously had been claimed impossible to make. This places it in the exclusive class of porous, high surface area materials,” said Ms Stromme.

The findings have been published in the journal PLOS ONE.

sciencedaily.com
Nov. 14, 2013

Large Graphene Crystals With Exceptional Electrical Properties Created

When it comes to the growth of graphene -- an ultrathin, ultrastrong, all-carbon material -- it is survival of the fittest, according to researchers at The University of Texas at Austin.

The team used surface oxygen to grow centimeter-size single graphene crystals on copper. The crystals were about 10,000 times as large as the largest crystals from only four years ago. Very large single crystals have exceptional electrical properties.

"The game we play is that we want nucleation (the growth of tiny 'crystal seeds') to occur, but we also want to harness and control how many of these tiny nuclei there are, and which will grow larger," said Rodney S. Ruoff, professor in the Cockrell School of Engineering. "Oxygen at the right surface concentration means only a few nuclei grow, and winners can grow into very large crystals."

The team -- led by postdoctoral fellow Yufeng Hao and Ruoff of the Department of Mechanical Engineering and the Materials Science and Engineering Program, along with Luigi Colombo, a material scientist with Texas Instruments -- worked for three years on the graphene growth method.

The team's paper, "The Role of Surface Oxygen in the Growth of Large Single-Crystal Graphene on Copper," is featured on the cover of the Nov. 8, 2013, issue of Science.

One of the world's strongest materials, graphene is flexible and has high electrical and thermal conductivity that makes it a promising material for flexible electronics, solar cells, batteries and high-speed transistors.

The team's understanding of how graphene growth is influenced by differing amounts of surface oxygen is a major step toward improved high-quality graphene films at industrial scale.

The team's method "is a fundamental breakthrough, which will lead to growth of high-quality and large area graphene film," said Sanjay Banerjee, who heads the Cockrell School's South West Academy of Nanoelectronics (SWAN). "By increasing the single-crystal domain sizes, the electronic transport properties will be dramatically improved and lead to new applications in flexible electronics."

Graphene has always been grown in a polycrystalline form, that is, it is composed of many crystals that are joined together with irregular chemical bonding at the boundaries between crystals ("grain boundaries"), something like a patch-work quilt. Large single-crystal graphene is of great interest because the grain boundaries in polycrystalline material have defects, and eliminating such defects makes for a better material.

By controlling the concentration of surface oxygen, the researchers could increase the crystal size from a millimeter to a centimeter. Rather than hexagon-shaped and smaller crystals, the addition of the right amount of surface oxygen produced much larger single crystals with multibranched edges, similar to a snowflake.

"In the long run it might be possible to achieve meter-length single crystals," Ruoff said. "This has been possible with other materials, such as silicon and quartz. Even a centimeter crystal size -- if the grain boundaries are not too defective -- is extremely significant."

"We can start to think of this material's potential use in airplanes and in other structural applications -- if it proves to be exceptionally strong at length scales like parts of an airplane wing, and so on," he said.

Another major finding by the team was that the "carrier mobility" of electrons (how fast the electrons move) in graphene films grown in the presence of surface oxygen is exceptionally high. This is important because the speed at which the charge carriers move is important for many electronic devices -- the higher the speed, the faster the device can perform.

Yufeng Hao says he thinks the knowledge gained in this study could prove useful to industry.

"The high quality of the graphene grown by our method will likely be developed further by industry, and that will eventually allow devices to be faster and more efficient," Hao said.

Single-crystal films can also be used for the evaluation and development of new types of devices that call for a larger scale than could be achieved before, added Colombo.

"At this time, there are no other reported techniques that can provide high quality transferrable films," Colombo said. "The material we were able to grow will be much more uniform in its properties than a polycrystalline film."

Journal Reference:

Y. Hao, M. S. Bharathi, L. Wang, Y. Liu, H. Chen, S. Nie, X. Wang, H. Chou, C. Tan, B. Fallahazad, H. Ramanarayan, C. W. Magnuson, E. Tutuc, B. I. Yakobson, K. F. McCarty, Y.-W. Zhang, P. Kim, J. Hone, L. Colombo, R. S. Ruoff. The Role of Surface Oxygen in the Growth of Large Single-Crystal Graphene on Copper. Science, 2013; 342 (6159): 720 DOI: 10.1126/science.1243879

Patents : RUOFF et al Graphene

Composite polymer film with graphene nanosheets as highly effective barrier property enhancers
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https://www6.slac.stanford.edu/news/2013-11-21-tin-super-material-stanene.aspx
November 21, 2013

Will 2-D Tin be the Next Super Material?

Theorists Predict New Single-Layer Material Could Go Beyond Graphene, Conducting Electricity with 100 Percent Efficiency at Room Temperature

Menlo Park, Calif. — A single layer of tin atoms could be the world’s first material to conduct electricity with 100 percent efficiency at the temperatures that computer chips operate, according to a team of theoretical physicists led by researchers from the U.S. Department of Energy’s (DOE) SLAC National Accelerator Laboratory and Stanford University.

Researchers call the new material "stanene," combining the Latin name for tin (stannum) with the suffix used in graphene, another single-layer material whose novel electrical properties hold promise for a wide range of applications.

"Stanene could increase the speed and lower the power needs of future generations of computer chips, if our prediction is confirmed by experiments that are underway in several laboratories around the world," said the team leader, Shoucheng Zhang, a physics professor at Stanford and the Stanford Institute for Materials and Energy Sciences (SIMES), a joint institute with SLAC. The team’s work was published recently in Physical Review Letters.

The Path to Stanene

For the past decade, Zhang and colleagues have been calculating and predicting the electronic properties of a special class of materials known as topological insulators, which conduct electricity only on their outside edges or surfaces and not through their interiors. When topological insulators are just one atom thick, their edges conduct electricity with 100 percent efficiency. These unusual properties result from complex interactions between the electrons and nuclei of heavy atoms in the materials.

“The magic of topological insulators is that by their very nature, they force electrons to move in defined lanes without any speed limit, like the German autobahn,” Zhang said. “As long as they’re on the freeway – the edges or surfaces – the electrons will travel without resistance.”

In 2006 and 2009, Zhang’s group predicted that mercury telluride and several combinations of bismuth, antimony, selenium and tellurium should be topological insulators, and they were soon proven right in experiments performed by others. But none of those materials is a perfect conductor of electricity at room temperature, limiting their potential for commercial applications.

Earlier this year, visiting scientist Yong Xu, who is now at Tsinghua University in Beijing, collaborated with Zhang’s group to consider the properties of a single layer of pure tin.

“We knew we should be looking at elements in the lower-right portion of the periodic table,” Xu said. “All previous topological insulators have involved the heavy and electron-rich elements located there.”

Their calculations indicated that a single layer of tin would be a topological insulator at and above room temperature, and that adding fluorine atoms to the tin would extend its operating range to at least 100 degrees Celsius (212 degrees Fahrenheit).

Ultimately a Substitute for Silicon?

Zhang said the first application for this stanene-fluorine combination could be in wiring that connects the many sections of a microprocessor, allowing electrons to flow as freely as cars on a highway. Traffic congestion would still occur at on- and off-ramps made of conventional conductors, he said. But stanene wiring should significantly reduce the power consumption and heat production of microprocessors.Manufacturing challenges include ensuring that only a single layer of tin is deposited and keeping that single layer intact during high-temperature chip-making processes.

“Eventually, we can imagine stanene being used for many more circuit structures, including replacing silicon in the hearts of transistors,” Zhang said. “Someday we might even call this area Tin Valley rather than Silicon Valley.”

Additional contributors included researchers from Tsinghua University in Beijing and the Max Planck Institute for Chemical Physics of Solids in Dresden, Germany. The research was supported by the Mesodynamic Architectures program of the Defense Advanced Research Projects Agency. Citation: Yong Xu et al., Physical Review Letters, 27 Sept 2013 (10.1103/PhysRevLett.111.136804)

http://prl.aps.org/abstract/PRL/v111/i13/e136804
Yong Xu et al., Physical Review Letters, 27 Sept 2013
(10.1103/PhysRevLett.111.136804)

The search for large-gap quantum spin Hall (QSH) insulators and effective approaches to tune QSH states is important for both fundamental and practical interests. Based on first-principles calculations we find two-dimensional tin films are QSH insulators with sizable bulk gaps of 0.3 eV, sufficiently large for practical applications at room temperature. These QSH states can be effectively tuned by chemical functionalization and by external strain. The mechanism for the QSH effect in this system is band inversion at the G point, similar to the case of a HgTe quantum well. With surface doping of magnetic elements, the quantum anomalous Hall effect could also be realized.

http://en.wikipedia.org/wiki/Stanene

Stanene

Stanene is a theoretical topological insulator which may display superconductivity at its edges above room temperature. It is composed of tin atoms arranged in a single layer, in a manner similar to graphene.[1] Stanene got its name by combining stannum (the Latin name for tin) with the suffix -ene used by graphene.[2]

The addition of fluorine atoms to the tin lattice could extend the critical temperature up to 100°C.[3] This would make it practical for use in integrated circuits to make smaller, faster and more energy efficient computers.

References

Yong Xu et al, Large-Gap Quantum Spin Hall Insulators in Tin Films, Physical Review Letters, 27 September 2013

Ritu Singh, Tin could be the next super material for computer chips, Zeenews, November 24, 2013

Will 2-D Tin be the Next Super Material?, SLAC National Accelerator Laboratory, Stanford University, November 21, 2013

David G. Yurth : “Seeing Past The Edge”

[ Excerpt ]

Using the work of V. Kronin as the basis for their treatment modality, a team of Russian physicians has been working at the laboratories of the Centers For Disease Control in Atlanta, Georgia, and Baylor University Medical Research Center in Houston, Texas, for more than a year. Their project demonstrates a revolutionary new medical treatment modality which capitalizes on this attribute of torsion field mechanics, to fundamentally cure patients infected with the hepatitis-C virus.i

The frequency signature of the hepatitis-C virus was mapped using infra-red spectrometry, a specially designed scalar interferometer and MRI technologies. The complex waveform which is mutually exclusive to the hepatitis-C virus was then fed into a desktop computer and converted to a waveform which was its phase conjugated opposite. The resulting waveform information was then fed to a torsion field generator which was used to irradiate a .5% molal solution of NaCl (Ringer's) for a period of 30 minutes. The ionic salt solution emitted a phase conjugated signal when fed into the patient’s system. The solution was infiltrated into the vascular system of 15 patients diagnosed with advanced cases of hepatitis-C. After 30 days of three-times-per-week treatment, 14 of the 15 patients were diagnosed as being completely free of any sign of infection. The 15th patient died during treatment from complications arising from an extremely advanced, chronic case of the disease. The technology is now being tested under double blind protocols by Dr. Robert Pennington and virologists at the Baylor University Medical Center.

http://www.thedailystar.net/beta2/news/student-invents-technology-to-produce-worlds-cheapest-power/
Star Business Report
December 15, 2013

Student invents technology to produce world’s ‘cheapest’ power

A Bangladeshi student has developed a system that can produce electricity without any fuel, claiming it to be the world’s cheapest form of power.

The system known as Heavy Circular Moving Object’s Triggering Energy Conversion (HECMOTE) uses round objects moving on a plain exterior, to capture the surface’s gravitational energy to run traditional generators to produce power.

“The technology is about converting gravitational energy into mechanical energy to generate electrical energy. It will not use any fossil fuel and thus, will not release any toxic elements into the atmosphere,” said Shahid Hossain, inventor of the new technology, at a press meet at Dhaka Reporters Unity yesterday.

Gravitational energy is potential energy an object possesses because of its position in a gravitational field.

Hossain, who is studying for a diploma in electrical engineering at a technical college in Uttara, began work on his idea in 2007.

A 100KVA power plant adopting Hossain’s technology was set up on an experimental basis in Tongi in 2011, which has been running successfully since then.

Hossain, 29, said the production cost of a kilowatt-hour of electricity would be Tk 0.2 with his system, whereas it is Tk 14.46 per kwh for a diesel-run plant.

The production cost of a unit of electricity with other renewable energy sources is even higher than that of the fossil fuel-run plants.

The operation and maintenance costs are also much lower; a 100MW HECMOTE power plant will cost Tk 1.5 crore a month against Tk 5 crore of a diesel-run plant.

The diesel-run power plant consumes fuel worth Tk 144,000 an hour whereas the HECMOTE power plant will not use any fuel.

The youth from Dinajpur said he ignored a lucrative offer from a Canadian firm a few years ago that offered to buy all rights of the technology.

Hossain said Bangladesh, an energy-starved nation, would benefit from the invention before it becomes available for others. “I need support from the government to make it commercial, as I will not be able to set up a plant capable of producing 100 megawatts of electricity worth crores of taka on my own.”

His company, UltraMax Power Development Ltd, plans to set up plants that are within a capacity of 5 megawatts and 10 megawatts.

The life-span of the system is 25 to 30 years, said Hossain.

He believes his invention could create a new dimension in solving the world’s present energy crisis.

Blue Light vs Bacteria

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3341

Effects of Photodynamic Therapy on Gram-Positive and Gram-Negative Bacterial Biofilms by Bioluminescence Imaging and Scanning Electron Microscopic Analysis

Objective: The aim of this study was to test photodynamic therapy (PDT) as an alternative approach to biofilm disruption on dental hard tissue, We evaluated the effect of methylene blue and a 660?nm diode laser on the viability and architecture of Gram-positive and Gram-negative bacterial biofilms. Materials and methods: Ten human teeth were inoculated with bioluminescent Pseudomonas aeruginosa or Enterococcus faecalis to form 3 day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify and evaluate the bacterial viability, and scanning electron microscopic (SEM) imaging was used to assess architecture and morphology of bacterial biofilm before and after PDT employing methylene blue and 40?mW, 660?nm diode laser light delivered into the root canal via a 300?µm fiber for 240?sec, resulting in a total energy of 9.6?J. The data were statistically analyzed with analysis of variance (ANOVA) followed by Tukey test. Results: The bacterial reduction showed a dose dependence; as the light energy increased, the bioluminescence decreased in both planktonic suspension and in biofilms. The SEM analysis showed a significant reduction of biofilm on the surface. PDT promoted disruption of the biofilm and the number of adherent bacteria was reduced. Conclusions: The photodynamic effect seems to disrupt the biofilm by acting both on bacterial cells and on the extracellular matrix.

http://online.liebertpub.com/doi/full/10.1089/pho.2013.9871

Antimicrobial Blue Light: An Emerging Alternative to Antibiotics

Chukuka S. Enwemeka, PhD, FACSM
College of Health Sciences. University of Wisconsin—Milwaukee, Milwaukee, Wisconsin.
E-mail: Enwemeka@uwm.edu

Bacterial resistance to drugs poses a major healthcare problem, causing widespread epidemic of diseases that hitherto were susceptible to antibiotics. Since penicillin was introduced in the 1940s, the pharmaceutical industry has countered this trend with periodic development and deployment of “stronger” antibiotics; however, bacteria in general, and methicillin-resistant Staphylococcus aureus (MRSA) in particular, have continually evolved a repertoire of evasive mechanisms that frequently defy antibiotic treatment. More than two billion people now carry some strain of S. aureus; 53 million of whom have MRSA.1 Estimates indicate that the United States alone spends 3.2–4.2 billion dollars on hospitalized patients with MRSA every year,2,3 and this does not include the human costs associated with lost labor, and lost lives, which now exceed that caused by HIV/AIDS.4

Deadly outbreaks of MRSA have been reported in every region of the world, with air travel and sociopolitical ties speeding the spread and resulting in the emergence of similar strains in countries with historical ties.3 Whereas infections were once confined to hospitals, that is, hospital-associated MRSA (HA-MRSA), the ongoing spread of community-associated MRSA (CA-MRSA) and livestock associated MRSA (LA-MRSA), and the reported jump of strains from animal to human and vice versa,5–9 now present a larger clinical conundrum. Pandemic strains of CA-MRSA have been found on beaches, computer keyboards, locker rooms, schools, athletic fields, and other common locations.10–13 It is now estimated that MRSA infection accounts for 44% of all hospital-associated infections in the United States; of these, as many as 92% are CA-MRSA.14

The continuing resistance of MRSA and other bacteria to antibiotics calls for a paradigm shift in the quest for therapies capable of stemming their spread. Alternative modalities currently under investigation include hyperbaric oxygen,15 photodynamic therapy (PDT),16 antibacterial clays,17 and blue light phototherapy.18–20 Interest in hyperbaric oxygen has waned, because of its moderate bactericidal effect compared with other emerging alternatives, such as PDT, antibacterial clay, and blue light. As shown in this issue of the journal, PDT, when used as an adjunct to conventional oral disinfection protocols, significantly reduces infection caused by ontopathogenic bacteria, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia.21 Moreover, the report shows that PDT kills cariogenic bacteria, including Streptococcus mutans and Streptococcus sanguis, as well as bacteria associated with infected root canals and peri-implantitis.21

This finding is supported by the work of Gacez et al.22 (in this issue), who showed that PDT, using 660?nm diode laser and methylene blue, significantly reduced infection in human root canals inoculated with Pseudomonas aeruginosa or Enterococcus faecalis. Similarly, PDT has been shown to be beneficial in treating dermatologic and ophthalmologic disorders.23,24 However, serious concerns remain for its acute side effects and the non-targeted nature of available photosensitizers.24 This situation calls for other alternatives to PDT, in spite of its beneficial antimicrobial effect. The Ebers Papyrus, published circa 1600 BCE,25 and the 5000-year-old tablets of Nippur26 identified clay and sunlight as therapies used by humans to treat a wide range of diseases, including infections caused by bacteria. Emerging reports now show that certain types of clay and light in the ultraviolet (UV), violet, and blue spectra have antibacterial properties.18–20,27

In this issue of the journal, we focus on articles that indicate that certain wavelengths of light are bactericidal and can eradicate recalcitrant bacteria in vitro and in vivo. First, a connection between light therapy and the antimicrobial action of clay may be seen in the work of Lipovsky et al.28 (in this issue) who showed that doping nanoparticles such as ZnO, CuO, and TiO2, with transition metals ions, or attaching the metal oxides nanoparticles to an organic molecule, enhances their antimicrobial reactive oxygen species (ROS) generation activity when irradiated with light in the visible and near infrared ranges. Furthermore, they found that ZnO and TiO2 nanoparticles had notable absorption in the blue spectrum, indicating that visible light could be used to trigger ROS production, and, hence, the antimicrobial effect of metal oxides. Studies of clay treatment similarly show that mineral leachates, including ions of copper, iron, cobalt, nickel, and zinc, from certain varieties of clay, are responsible for the antibacterial action of clay against Escherichia coli and MRSA.17 That light may be equally involved in clay treatment remains unexplored, but a potential role cannot be ruled out entirely.

Similarly, encouraging data from Dai et al.,29 (in this issue) indicate that the bacteria- eradicating effect of blue light, long reported in a multitude of in vitro studies,18–20,27 is achievable in vivo. They found that irradiation with 415±10?nm blue light reduced bacterial burden in abrasive skin wounds of laboratory rats inoculated with CA-MRSA. Furthermore, bacterial clearance was achieved without significant adverse effect on keratinocytes co-cultured with CA-MRSA. And electron microscopy revealed that irradiation of the bacteria caused extrusions of cytoplasmic content, cell wall damage, and cell debris, providing an insight into the potential mechanisms involved in photo-eradication of MRSA. However, these results are achievable only with certain parameters, as suggested by the preliminary findings of Lanzafame et al.,30 (in this issue) who found significant reduction of bacteria with photo-activated collagen-embedded flavins (PCF) treatment, but not with 455±5?nm blue light irradiation alone, when treating pressure ulcers in mice inoculated with MRSA. The implication is that experimental model and mode of treatment can significantly affect the results obtained in these types of studies.

Further evidence that experimental parameters influence outcomes can be seen in the work of Bumah et al.31 and Kim et al.32 For example, Bumah et al.31 showed that irradiation with either 405 or 470?nm blue light cleared MRSA progressively as fluence increased, and also as bacterial density increased, even though the proportion of bacterial colonies cleared decreased inversely as bacterial density. Whereas both wavelengths had similar effects on less dense cultures, that is, 3×106 colony-forming units (CFU)/mL and 5×106 CFU/mL cultures, 405?nm light cleared more bacteria in the denser 7×106 CFU/mL culture. And regardless of wavelength, more bacteria were cleared when the culture plates were irradiated from above and below instead of being irradiated from one direction at the same corresponding total dose. The latter finding suggests that the bactericidal effect of light-emitting diode (LED) blue light is limited more by the ability of blue light to penetrate the layers of bacteria than by bacterial density alone. That wavelength affects the outcome of LED photo-irradiation of bacteria is corroborated by Kim et al.32 They showed that, even though P. gingivalis and E. coli are killed with 425?nm blue light, 525?nm green light only induces bacteriostatic effect. Also, 625?nm red light did not kill any of the bacteria tested.

Collectively, these reports present further evidence that light, in particular, blue light in the range of 405–470?nm wavelength is bactericidal, and has the potential to help stem the ongoing pandemic of MRSA and other bacterial infections.

References

1. Moellering, R.C. (2006). The growing menace of community acquired methicillin-resistant Staphylococcus aureus. Ann. Intern. Med. 144, 368–370.
2. Klevens, R., Morrison, M.A., Nadle J., et al. (2007). Methicillin-resistant Staphylococcus aureus infections in the United States. JAMA 298, 1763–1771.
3. Chartterjee, S.S., and Otto, M. (2013). Improved understanding of factors driving methicillin-resistant Staphylococcus aureus epidemic wave. Clin. Epidemiol. 5, 205–217.
4. Graham, J. (2007). Deaths from drug-resistant bacteria top those from AIDS. Chicago Tribune, October 17, 2007.
5. Faires, M.C., Tater, M.C., and Weese, J.S. (2009). An investigation of methicillin-resistant Staphylococcus aureus colonization in people and pets in the same household with an infected person or infected pet. J. Am. Vet. Med. Assoc. 235, 540–543.
6. Lin, Y., Barker, E., Kislow, J., et al. (2011). Evidence of multiple virulence sub-types of nosocomial and community-associated MRSA genotypes in companion animals from the upper midwestern and northeastern United States. Clin. Med. Res. 9, 7–16.
7. Fluit, A.C. (2012). Livestock-associated Staphylococcus. Clin. Microbiol. Infect. 18, 735–744.
8. Walther, B., Wieler, L.H., Vineze, S. et al. (2012). MRSA variant in companion animals. Emerg. Infect. Dis. 18, 2017–2020.
9. Petinaki, E., and Spiliopoulou, I. (2012) Methicillin-reistant Staphylococcus aureus among companion and food-chain animals: impact of human contacts. Clin. Microbiol. Infect. 18, 626–634.
10. Morris, D.O., Lautenbach, E., Zaoutis, T., Leckerman, K., Delsterin, P.H., and Rankin, S.C. (2012). Potential for pet animals to harbor methicillin-resistant Staphylococcus aureus when residing with human MRSA patients. Zoonoses Public Health 59, 286–293.
11. Bures, S., Fishbain, J.T., Uyehara, C.F.T., Parker, J.M., and Berg, B.W. (2000). Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit. Am. J. Infect. Control 28, 465–471.
12. Begier, E.M., Frenette, K., Barrett, N.L., et al. (2004). A high morbidity outbreak of methicillin-resistant Staphylococcus aureus among players on a college football team, facilitated by cosmetic body shaving and turf burns. Clin. Infect. Dis. 39, 1446–1453.
13. Gould, I.M., Reilly, J., Bunyan, D., and Walker, A. (2010). Costs of healthcare-associated methicillin-resistant Staphylococcus aureus and its control. Clin. Microbiol. Infect. 16, 1721–1728.
14. Mccullough, A.C., Seifried, M., Zhao, X., et al. (2011). Higher incidence of perineal community acquired MRSA infections among toddlers. BMC Pediatr. 11, 96.
15. Turhan, V., Sacar, S., Uzun, G., Sacar, M., Yildiz, S., Ceran, N., Gorur, R., and Oncul, O. (2009). Hyperbaric oxygen as adjunctive therapy in experimental mediastinitis. J. Surg. Res. 155, 111–115.
16. Grinholc, M., Kawiak, A., Kurlenda, J., Graczyk, A., and Bielawski, K.P. (2008). Photodynamic effect of protoporphyrin diarginate (PPArg2) on methicillin resistant Staphylococcus aureus and human dermal fibroblasts. Acta Biochim. Pol. 55, 85–90.
17. Otto, C.C., and Haydel, S.E. (2013) Exchangeable ions are responsible for the in vitro antibacterial properties of natural clay mixtures. PLoS One 8, e64068.
18. Enwemeka, C.S., Williams, D., Hollosi, S., and Yens, D. (2008). Blue light photo destroys methicillin resistant Staphylococcus aureus (MRSA) in vitro, in: Proceedings of Light-Activated Tissue Regeneration and Therapy Conference. R. Waynant, and D. Tata (eds.). New York: Springer, pp. 33–37.
19. Enwemeka, C.S., Williams, D., Hollosi, S., Yens, D., and Enwemeka, S.K. (2008). Visible 405?nm SLD photo-destroys methicillin resistant Staphylococcus aureus (MRSA) in vitro, Lasers Surg. Med. 40, 734–737.
20. Enwemeka, C. S., Williams, D., Hollosi, S., Enwemeka, S.K., Hollosi, S., and Yens, D. (2009). Blue 470-nm light kills methicillin-resistant (MRSA) in vitro Photomed. Laser Surg. 27, 221–226.
21. Javed, F., and Romanos, G.E. (2013). Does photodynamic therapy enhance standard antibacterial therapy in dentistry? Photomed. Laser Surg. 31, 000–000.
22. Garcez, A.S., Núñez, S.C., Azambuja, Jr., N., Fregnani, E.R., Rodriguez, H.M.H., Hamblin, M.R., Suzuki, H., and Ribeiro, M.S. (2013). Effects of photodynamic therapy on gram-positive and gram–negative bacterial biofilms by bioluminescence imaging and scanning electron microscopic analysis. Photomed. Laser Surg. 31, 000–000.
23. Tianhong, D., Tegos, G.P., Zhiyentayev, T., Mylonakis, E., and Hamblin, M.R., (2010). Methicillin-resistant Staphylococcus aureus infection in a mouse skin abrasion model. Lasers Surg. Med. 42, 38.
24. Mitsunaga, M., Ogawa, M., Kosaka, N., Rosenblum, L.T., Choyke, P.L., and Kobayashi, H. (2011). Cancer cell-selectivity in vivo near infrared photoimmunotherapy targeting specific membrane molecules. Nat. Med. 17, 1685–1671.
25. Bryan, C.P. (1930). The Papyrus of Ebers. Letchworth: The Garden City Press Ltd.
26. Peters, J.P. (1905). The Nipur Library. J Am Orient Soc 26, 145–164.
27. Maclean, M., MacGregor, S.J., Anderson, J.G., and Woolsey, G. (2009). Inactivation of bacterial pathogens following exposure to light from a 405nm light-emitting diode array. Appl. Environ. Microbiol. 75, 1932–1937.
28. Lipovsky, A., Gedanken, A., and Lubart, R. (2013). Visible light-induced antibacterial activity of metaloxide nanoparticles. Photomed. Laser Surg. 31, 000–000.
29. Dai, T., Gupta, A., Huang, Y.-Y., Sherwood, M.E., Murray, C.K., Vrahas, M.S., Kielian, T., and Hamblin, M.R. (2013). Blue light eliminates community-acquired methicillin-resistant Staphylococcus aureus in infected mouse skin abrasiions. Photomed. Laser Surg. 31, 000–000.
30. Lanzafame, R.J., Stadler, I., Cunningham, R., Muhlbauer, A., Griggs, J., Soltz, R., and Soltz, B.A. (2013). Preliminary assessment of photoactivated antimicrobial collagen on bioburden in a murine pressure ulcer model. Photomed. Laser Surg. 31, 000–000.
31. Bumah, V.V., Masson–Meyers, D.S., Cashin, S.E., and Enwemeka, C.S. (2013). Wavelength and bacterial density influence the bactericidal effect of blue light on methicillin-reistant Staphylococcus aureus (MRSA). Photomed. Laser Surg. 31, 000–000.
32. Kim, S., Kim, J., Lim, W., Jeon, S., Kim, O., Koh, J.-T., Kim, C.-S., Choi, H., and Kim, O. (2013). In vitro bactericidal effects of 625?nm, 525?nm and 425?nm wavelength (red, green and blue) light emitting diode (LED) irradiation. Photomed. Laser Surg. 31, 000–000.

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3365

Blue Light Eliminates Community-Acquired Methicillin-Resistant Staphylococcus aureus in Infected Mouse Skin Abrasions

New Rochelle, NY--Blue light has proven to have powerful bacteria-killing ability in the laboratory. The potent antibacterial effects of irradiation using light in the blue spectra have now also been demonstrated in human and animal tissues. A series of groundbreaking articles that provide compelling evidence of this effect are published in Photomedicine and Laser Surgery, a peer-reviewed journal published by Mary Ann Liebert, Inc., publishers. The articles are available on the Photomedicine and Laser Surgery website (http://www.liebertpub.com/pho).

"Bacterial resistance to drugs poses a major healthcare problem," says Co-Editor-in-Chief Chukuka S. Enwemeka, PhD, Dean, College of Health Sciences, University of Wisconsin--Milwaukee, in the accompanying Editorial "Antimicrobial Blue Light: An Emerging Alternative to Antibiotics," (http://online.liebertpub.com/doi/full/10.1089/pho.2013.9871) citing the growing number of deadly outbreaks worldwide of methicillin-resistant Staphylococcus aureus (MRSA). The articles in this issue of Photomedicine and Laser Surgery provide evidence that "blue light in the range of 405-470 nm wavelength is bactericidal and has the potential to help stem the ongoing pandemic of MRSA and other bacterial infections."

In the article "Effects of Photodynamic Therapy on Gram-Positive and Gram-Negative Bacterial Biofilms by Bioluminescence Imaging and Scanning Electron Microscopic Analysis," (http://online.liebertpub.com/doi/full/10.1089/pho.2012.3341) Aguinaldo S. Garcez, PhD and coauthors show that photodynamic therapy and methylene blue delivered directly into the root canal of a human tooth infected with a bacterial biofilm was able to destroy both Gram-positive and Gram-negative bacteria, disrupt the biofilms, and reduce the number of bacteria adhering to the tooth.

Raymond J. Lanzafame, MD, MBA, and colleagues demonstrated significantly greater bacterial reduction in the treatment of pressure ulcers in mice using a combination of photoactivated collagen-embedded compounds plus 455 nm diode laser irradiation compared to irradiation alone or no treatment. The antibacterial effect of the combined therapy increased with successive treatments, report the authors in the article "Preliminary Assessment of Photoactivated Antimicrobial Collagen on Bioburden in a Murine Pressure Ulcer Model." (http://online.liebertpub.com/doi/full/10.1089/pho.2012.3423)

In the article "Wavelength and Bacterial Density Influence the Bactericidal Effect of Blue Light on Methicillin-Resistant Staphylococcus aureus (MRSA)," (http://online.liebertpub.com/doi/full/10.1089/pho.2012.3461) Violet Bumah, PhD and coauthors compared the bacteria-killing power of 405 nm versus 470 nm light on colonies of resistant Staph aureus and how the density of the bacterial colonies could limit light penetration and the bactericidal effects of treatment.

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3329

Does Photodynamic Therapy Enhance Standard Antibacterial Therapy in Dentistry?

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3423

Preliminary Assessment of Photoactivated Antimicrobial Collagen on Bioburden in a Murine Pressure Ulcer Model

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3343

In Vitro Bactericidal Effects of 625, 525, and 425?nm Wavelength (Red, Green, and Blue) Light-Emitting Diode Irradiation

http://online.liebertpub.com/doi/abs/10.1089/pho.2012.3461

Wavelength and Bacterial Density Influence the Bactericidal Effect of Blue Light on Methicillin-Resistant Staphylococcus aureus (MRSA)

http://kericure.com/

Bioorganic & Medicinal Chemistry Letters 17 (2007) 53–56

Antibiotic-conjugated polyacrylate nanoparticles: New opportunities for development of anti-MRSA agents

ABSTRACT: This report describes the preparation of polyacrylate nanoparticles in which an N-thiolated b-lactam antibiotic is covalently conjugated onto the polymer framework. These nanoparticles are formed in water by emulsion polymerization of an acrylated antibiotic pre-dissolved in a liquid acrylate monomer (or mixture of co-monomers) in the presence of sodium dodecyl sulfate as a surfactant and potassium persulfate as a radical initiator. Dynamic light scattering analysis and electron microscopy images of these emulsions show that the nanoparticles are approximately 40 nm in diameter. The emulsions have potent in vitro antibacterial properties against methicillin-resistant Staphylococcus aureus and have improved bioactivity relative to the non-polymerized form of the antibiotic. A unique feature of this methodology is the ability to incorporate water-insoluble drugs directly into the nanoparticle framework without the need for post-synthetic modification. Additionally, the antibiotic properties of the nanoparticles can be modulated by changing the length or location of the acrylate linker on the drug monomer. 2006 Elsevier Ltd. All rights reserved.

http://www.wtsp.com/rss/article/350137/12/USF-invention-helps-close-wounds-big-and-small

USF invention helps close wounds big and small

Dec 25, 2013

Tampa, Florida -- The University of South Florida ranks 10th among universities worldwide in U.S. patents. One of the inventions that's putting USF on the map is a liquid bandage that helps close wounds both big and small.

While getting her PhD, Dr. Kerriann Greenhalgh was collaborating with a professor at USF on a project when she discovered a polymer could be turned into a bandage.

"I was really struck by its elastic properties, its ability to stretch and move with the body and then come back to its original shape which is very similar to the skin," Greenhalgh said.

In the midst of her research, her soon-to-be husband had a nasty cut that developed staph that needed immediate surgery to avoid nerve damage or amputation. That's when she knew she needed to push forward with KeriCure.

"It just kind of clicked for me," Greenhalgh said. "This would make a great skin, a secondary skin, an artificial skin to help clean wounds clean and infection free. "

She tinkered with the formula, even tested it on her own cuts and scrapes, and created a water based solution that has no harsh chemicals or preservatives.

"When you put it on, you spray it on your hand. It forms a protective barrier and it protects bacteria from getting in. But because it's water-based, there's no stinging involved and it actually helps to hydrate the wound and it keeps it moisturized which actually helps with the cosmetic outcome of the wound as well."

While its competitors are flexible, they don't have the same elasticity which allows you to move your knuckles while it's on. It's also waterproof and sweatproof.

"You can go swimming with it," Greenhalgh said. "The EMTs at SeaWorld have it in their pockets which is great there you know the kids have these cuts and if they put band aids on them then they're putting their hands in the fish tanks in the touch tanks and you get band aids in there and it's awful."

The spray is attached to a keychain or you can put it in your pocket, and with about 170 liquid bandages in a bottle for $10.99 at major retailers like Publix and Kroger, KeriCure is sealing up success.

"Our motto with this product is KeriCure and carry on so it's really intended for moms, people on the go, active lifestyles doing sports to really be able to spray it and keep going about their business and not have to worry about it."

KeriCure is Tampa-based company with five full-time employees. It's manufactured and packaged locally too. Since KeriCure is partners with USF, the company has lab space and supports eight undergraduates, giving them real life research experience.

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