As physician-guided robots routinely operate on patients at most major hospitals, the next generation robot could eliminate a surprising element from that scenario -- the doctor.Feasibility studies conducted by Duke University bioengineers have demonstrated that a robot -- without any human assistance -- can locate a man-made, or phantom, lesion in simulated human organs, guide a device to the lesion and take multiple samples during a single session. The researchers believe that as the technology is further developed, autonomous robots could some day perform many more simple surgical tasks."Earlier this year we demonstrated that a robot directed by artificial intelligence can on its own locate simulated calcifications and cysts in simulated breast tissue with high repeatability and accuracy," said Kaicheng Liang, a former student in the laboratory of Stephen Smith, director of the Duke University Ultrasound Transducer Group at the Pratt School of Engineering and senior member of the research team. "Now we have shown that the robot can sample up to eight different spots in simulated human prostate tissue." »

Electrons are negatively charged elementary particles. They form the shells around atoms and ions. This or something similar is what you will find in text books. Soon, however, this information may have to be supplemented.The reason is that many physicists believe that electrons have a permanent electric dipole moment. An electric dipole moment is usually created when positive and negative charges are spatially separated. Similar to the north and south poles of a magnet, there are two electric poles. In the case of electrons, the situation is much more complicated because electrons should not actually have any spatial dimension.Despite this, an entire range of physical theories that go beyond the standard model of elementary particle physics are based upon the existence of dipole moment. These theories in turn would explain how the universe in the form that we know it could have been created in the first place. According to prevailing theories, the big bang some 13.7 billion years ago would have had to have created just as much matter as antimatter. Since both obliterate each other, nothing would have remained. In reality, however, more matter than antimatter was actually created. An electric dipole moment of the electron could explain this imbalance.Up to now, nobody has successfully proven the existence of this assumed tiny dipole moment. Existing methods are simply not sensitive enough. A small piece of ceramic is set to change this soon. »

By imaging the cell walls of a zinnia leaf down to the nanometer scale, energy researchers have a better idea about how to turn plants into biofuels.In a paper appearing online in the journal Plant Physiology, a team from Lawrence Livermore led by Michael Thelen, in collaboration with researchers from Lawrence Berkeley National Lab and the National Renewable Energy Laboratory, has used four different imaging techniques to systematically drill down deep into the cells of Zinnia elegans.Zinnia is a common garden annual plant with solitary daisy like flower heads on long stems and sandpapery, lace shaped leaves. The leaves of seedlings provide a rich source of single cells that are dark green with chloroplasts and can be cultured in liquid for several days at a time. During the culturing process, the cells change in shape to resemble the tube-like cells that carry water from roots to leaves. Known as xylem, these cells hold the bulk of cellulose and lignin in plants, which are both major targets of recent biofuel research.Using different microscopy methods, the team was able to visualize single cells in detail, cellular substructures, fine-scale organization of the cell wall, and even chemical composition of single zinnia cells, indicating that they contain an abundance of lignocellulose. »

Because they can remove carbon dioxide from the flue gases of coal-burning facilities such as power plants, solid materials containing amines are being extensively studied as part of potential CO2 sequestration programs designed to reduce the impact of the greenhouse gas.But although these adsorbent materials do a good job of trapping the carbon dioxide, commonly-used techniques for separating the CO2 from the amine materials -- thereby regenerating them for re-use -- seem unlikely to be suitable for high-volume industrial applications.Now, researchers have demonstrated a relatively simple regeneration technique that could utilize waste steam generated by many facilities that burn fossil fuels. This steam-stripping technique could produce concentrated carbon dioxide ready for sequestration in the ocean or deep-earth locations -- while readying the amine materials for further use."We have demonstrated an approach to developing a practical adsorption process for capturing carbon dioxide and then releasing it in a form suitable for sequestration," said Christopher Jones, a professor in the School of Chemical & Biomolecular Engineering at the Georgia Institute of Technology.The research was reported online June 23, 2010 in the early view version of the journal ChemSusChem. The work was supported by New York-based Global Thermostat, LLC., a company that is developing and commercializing technology for the direct capture of carbon dioxide from the air.s designed to reduce the impact of the greenhouse gas. »

While prospectors and geologists have been successful in finding diamonds through diligent searching, one University of Houston professor and his team's work could help improve the odds by focusing future searches in particular areas.Kevin Burke, professor of geology and tectonics at UH, and his fellow researchers describe these findings in a paper appearing July 15 in Nature, the weekly scientific research journal.Burke's team found that kimberlites, which are rare volcanic rocks that include diamonds, owe their origin to occasional pulses of hot mantle rock -- called mantle plumes -- that have risen through the entire thickness of the Earth's mantle from deep down next to the core, or innermost part, of the planet. This core/mantle boundary lies at a depth of about 2,000 miles. While the idea there might be mantle plumes rising from the core/mantle boundary was first suggested about 40 years ago, it is only within the past few years that evidence of plumes coming all the way from this boundary to the Earth's surface has been clearly demonstrated by Burke's group."Our approach is new, because it combines observations of the Earth's deep interior from seismology with evidence of how tectonic plates have moved about on the Earth's surface during the past 500 million years," Burke said. "I have been interested in mantle plumes from the core/mantle boundary since they were first hypothesized in 1971. About 10 years ago, I realized there might be a link between the seismically defined structure at the core/mantle boundary and volcanic rocks at the Earth's surface that had been suggested to be linked to mantle plumes. I immediately realized how the existence of that link could be tested, and it was then that I came in contact with Trond Torsvik in Norway, who proved to be uniquely qualified to carry out the required tests." »

The movement of long chain polymers through nanopores is a key part of many biological processes, including the transport of RNA, DNA, and proteins. New research reported in The Journal of Chemical Physics, which is published by the American Institute of Physics, describes an improved theoretical model for this type of motion.The new model addresses both cylindrical pores and tapering pores that simulate the α-hemolysin membrane channel. "Current models do not take into account the motion of the polymer inside the pore," says author Anatoly Kolomeisky of Rice University. "The leading monomer can move back and forth many times before it finally crosses the line to the other side of the membrane. Not accounting for this behavior introduces errors into predictions."By improving the boundary conditions for polymer movement inside the pore, researchers demonstrated a significant increase in total time in the pore compared to earlier models. In modeling a tapering pore, they confirmed that translocation occurs faster when the polymer enters the wide side of the pore.Possible technological applications include advances in DNA sequencing and the development of biosensors using membranes. "To design an effective sensor, it is essential to understand what you are observing and how the molecule reaches the detector," says Kolomeisky. »

Research reported in The Journal of Chemical Physics, which is published by the American Institute of Physics, provides the first real-time measurements of the time dependence of the individual steps of dissociation of a complex consisting of two rare gas atoms and a halogen molecule."The goal of this work is to provide a test case for quantum dynamics theory," says author Kenneth C.Janda of the University of California, Irvine. "It is a problem that is easy, but not too easy, in the sense that a fundamental quantum dynamics explanation is within reach."Researchers cooled a mixture of helium, neon, and bromine by spraying it through a nozzle, resulting in a stream of gas particles traveling at the same speed. This created a very low temperature in a moving frame of reference -- the particles were stationary relative to one another and condensed to form Ne2Br2 tetrahedral complexes. After the bromine molecule was excited with a laser pulse, the dissociation of the complex over a period of tens of picoseconds was observed spectroscopically. Adding 16 quanta of vibrational energy to the bromine-stretching vibration resulted in rapid direct dissociation. The two Ne atoms dissociated without interacting with each other. However, with slightly higher vibrational excitation, a 23-quanta boost, the bromine anharmonicity led to sharing of the kinetic energy between the Ne atoms and a much more complicated dissociation mechanism. »

Conventional wisdom holds that optical microscopy can't be used to "see" something as small as an individual molecule. But science has once again overturned conventional wisdom. Secretary of Energy, Nobel laureate and former director of the Lawrence Berkeley National Laboratory (Berkeley Lab) Steven Chu led the development of a technique that enables the use of optical microscopy to image objects or the distance between them with resolutions as small as 0.5 nanometers -- one-half of one billionth of a meter, or an order of magnitude smaller than the previous best."The ability to get sub-nanometer resolution in biologically relevant aqueous environments has the potential to revolutionize biology, particularly structural biology," says Secretary Chu. "One of the motivations for this work, for example, was to measure distances between proteins that form multi-domain, highly complex structures, such as the protein assembly that forms the human RNA polymerase II system, which initiates DNA transcription."Secretary Chu is the co-author of a paper now appearing in the journal Nature that describes this research. The other authors are Alexandros Pertsinidis, a post-doctoral researcher and member of Chu's research group at the University of California (UC) Berkeley, who is now an assistant professor at the Sloan-Kettering Institute, and Yunxiang Zhang, a member of Chu's research group at Stanford University. »

Scientists have been trying for some 20 years to understand why the low temperature at which copper-oxide superconductors carry current with no resistance can't be increased to be closer to room temperature. Recently, scientists have focused on trying to understand and control an electronic phase called the "pseudogap" phase, which is non-superconducting and is observed at a temperature above the superconducting phase. But what form of electronic order (if any) characterizes the pseudogap phase has remained a frustrating and challenging mystery.Now scientists have discovered a fundamental difference in how electrons behave at the two distinct oxygen-atom sites within each copper-oxide unit, which appears to be a specific property of the non-superconducting pseudogap phase. The research -- described in the July 15, 2010, issue of Nature -- may lead to new approaches to understanding the pseudogap phase, which has been hypothesized as a key hurdle to achieving room-temperature superconductivity."Many people consider the disappearance of superconductivity that occurs when the pseudogap phase emerges as an indication that the pseudogap is the killer of room temperature superconductivity in the copper-oxides," said study leader Séamus Davis, director of the Center for Emergent Superconductivity at the U.S. Department of Energy's Brookhaven National Laboratory and the J.D. White Distinguished Professor of Physical Sciences at Cornell University. "Detecting a difference in electron behavior at the two oxygen sites within each copper-oxide unit at the pseudogap energy may be a very significant step toward identifying exactly what the pseudogap state is and how it affects superconductivity." »

What would be the point of holding a soccer world championship if we couldn't distinguish the ball from its background? Simply unthinkable! But then again, wouldn't it be fantastic if your favourite team's striker could see the movements of the ball in slow motion! Unfortunately, this advantage only belongs to flies.The minute brains of these aeronautic acrobats process visual movements in only fractions of a second.Just how the brain of the fly manages to perceive motion with such speed and precision is predicted quite accurately by a mathematical model. However, even after 50 years of research, it remains a mystery as to how nerve cells are actually interconnected in the brain of the fly. Scientists at the Max Planck Institute of Neurobiology are now the first to successfully establish the necessary technical conditions for decoding the underlying mechanisms of motion vision. The first analyses have already shown that a great deal more remains to be discovered.The research is published in the journal Nature Neuroscience (July 11, 2010).Back in 1956, a mathematical model was developed that predicts how movements in the brain of the fly are recognized and processed. Countless experiments have since endorsed all of the assumptions of this model. What remains unclear, however, is the question as to which nerve cells are wired to each other in the fly brain for the latter to function as predicted in the model. "We simply did not have the technical tools to examine the responses of each and every cell in the fly's tiny, but high-powered brain," as Dierk Reiff from the Max Planck Institute of Neurobiology in Martinsried explains. That is hardly surprising, considering the minute size of the brain area that is responsible for the fly's motion detection. Here, one sixth of a cubic millimetre of brain matter contains more than 100,000 nerve cells -- each of which has multiple connections to its neighbouring cells. Although it seems almost impossible to single out the reaction of a certain cell to any particular movement stimulus, this is precisely what the neurobiologists in Martinsried have now succeeded in doing. »