July 1, 2010, 7:18 AM CT

Unpeeling Atoms and Molecules from the Inside Out

Menlo Park, Calif.-The first published scientific results from the world's most powerful hard X-ray laser, located at the Department of Energy's SLAC National Accelerator Laboratory, show its unique ability to control the behaviors of individual electrons within simple atoms and molecules by stripping them away, one by one-in some cases creating hollow atoms.

These early results-one published recently, the other last week-describe in great detail how the Linac Coherent Light Source's intense pulses of X-ray light change the very atoms and molecules they are designed to image. Controlling those changes will be critical to achieving the atomic-scale images of biological molecules and movies of chemical processes that the LCLS is designed to produce.

In a report reported in the July 1 issue of Nature, a team led by Argonne National Laboratory physicist Linda Young describes how they were able to tune LCLS pulses to selectively strip electrons, one by one, from atoms of neon gas. By varying the photon energies of the pulses, they could do it from the outside in or-a more difficult task-from the inside out, creating so-called "hollow atoms."

"Until very recently, few believed that a free-electron X-ray laser was even possible in principle, let alone capable of being used with this precision," said William Brinkman, director of DOE's Office of Science. "That's what makes these results so exciting."........ Posted by: Beverly      Read more         Source

June 30, 2010, 7:12 AM CT

Robotic fish gives clues about group dynamics

To gain insights into group dynamics for the study of collective animal behavior in moving groups, robots have a valuable role to play. Enter "Robofish", a computer-controlled replica stickleback that can be programmed to move around a tank. The brainchild of biologists from the University of Leeds in the UK, Robofish can both recruit and lead fish and shed light on what motivates fish in a shoal to change direction - in this case, the number of neighboring fish is more influential than the absolute distance from the shoal leader. The findings have just been published in Springer's journal Behavioral Ecology and Sociobiology.

Lead author of the study Jolyon Faria and his team introduce a novel tool to study the collective behavior of fish, and in particular, how individuals influence the movement of others in the group. They constructed Robofish and looked at two types of interaction between three-spined sticklebacks and Robofish: recruitment of fish from a refuge and initiation of a new swimming direction to test leadership. They placed Robofish in a tank with live fish collected from the Great Eau river estuary in the UK and observed the fishes' behavior in response to Robofish leaving the refuge, and shortly after, making a 90 degree turn.

Robofish quickly encouraged single fish out of the tank refuge, that would normally hesitate to venture out, and was able to make both single fish and fish in groups of up to ten turn inside the tank in the same direction as itself, demonstrating Robofish's ability to be a leader. The influence of Robofish fell after the first 30 minutes the fish had spent in the new tank......... Posted by: Beverly      Read more         Source

June 24, 2010, 11:26 PM CT

Translating Language of Nanopores

National Institute of Standards and Technology (NIST) researchers have moved a step closer to developing the means for a rapid diagnostic blood test that can scan for thousands of disease markers and other chemical indicators of health. The team reports* it has learned how to decode the electrical signals generated by a nanopore-a "gate" less than 2 nanometers wide in an artificial cell membrane.

Nanopores are not new themselves; for more than a decade, researchers have sought to use a nanopore-based electrical detector to characterize single-stranded DNA for genetic sequencing applications. More recently, NIST researchers turned their attention to using nanopores to identify, quantify and characterize each of the more than 20,000 proteins the body produces-a capability that would provide a snapshot of a patient's overall health at a given moment. But while nanopores permit molecules to enter into them one at a time, determining what specific individual molecule has just passed through has not been easy.

To address this problem, members of the NIST team that previously developed a method to distinguish both the size and concentration of each type of molecule the nanopore admits** have now answered the question of just how these single molecules interact with the nanopore. Their new theoretical model describes the physics and chemistry of how the nanopore, in effect, parses a molecule, an understanding that will advance the use of nanopores in the medical field......... Posted by: Beverly      Read more         Source

June 24, 2010, 10:39 PM CT

Green, bio-based process for producing fuel additive

A new green, bio-based method for producing a much-used fuel additive and industrial chemical that is currently made from petroleum products has been developed by an Iowa State University researcher.

Thomas Bobik, professor of biochemistry, biophysics and molecular biology, invented a process for manufacturing isobutene (isobutylene) by identifying a new, natural enzyme that produces the fuel organically.

Bobik, along with David Gogerty, a doctoral student working with him on the project, think that once more research is completed, there could be huge benefits to the biofuels industry.

"I would emphasize that we are very early on in the process," said Bobik. "But isobutene has some special properties that could have a big impact."

Bobik's enzyme makes it possible to convert the glucose found naturally in plants to make isobutene. The enzyme is found naturally in about half of all organisms in the world.

While patent applications proceed, Bobik will not disclose the specific enzyme.

Isobutene is a gas used to produce chemicals and also in the manufacturing of fuel additives, adhesives, plastics and synthetic rubber.

It can be chemically converted to isooctane, which is a fuel that could be used to replace gasoline additive methyl tert-butyl ether (MBTE), which can be environmentally harmful......... Posted by: Beverly      Read more         Source

June 9, 2010, 11:11 PM CT

Beading-saliva mystery

Scientists have discovered precisely why strands of some fluids containing long molecules called polymers form beads when stretched, findings that could be used to improve industrial processes and for administering drugs in "personalized medicine".

"Any kindergartner is familiar with this beading phenomenon, which you can demonstrate by stretching a glob of saliva between your thumb and forefinger," said Osman Basaran, Purdue's Burton and Kathryn Gedge Professor of Chemical Engineering.

Before the strand of spittle breaks, a string of beads is formed.

"The question is, why does this beading take place only in some fluids containing polymers but not others?" Basaran said.

Now engineers and researchers at Purdue, the Massachusetts Institute of Technology and Rice University have solved the riddle in work led by Purdue postdoctoral researcher Pradeep Bhat. The scientists have determined the mechanism behind the beading and created a computational model to simulate the phenomenon.

Knowing the answer to this question might enable scientists to design systems that precisely control bead formation, leading to improvements in various technologies such as inkjet printing. The information also might be used in a system that precisely dispenses the correct dose of medications for individual patients based on simple blood tests......... Posted by: Beverly      Read more         Source

March 22, 2010, 8:05 PM CT

New 'smart' roof reads the thermometer

Top a building with a light-colored "cool roof," and it reflects sunlight, cutting air conditioning bills in summer, but increasing winter heating costs. Choose black shingles, and the roof soaks up sunlight to cut winter heating costs but makes the roof bake in the summer sun. One or the other. You can't have it both ways.

Until now.

Researchers today reported the development of a "smart" roof coating, made from waste cooking oil from fast food restaurants, that can "read" a thermometer. The coating automatically switches roles, reflecting or transmitting solar heat, when the outdoor temperature crosses a preset point that can be tuned to the local climate.

They described the coating at the 239th National Meeting of the American Chemical Society (ACS), being held here this week.

Roofs coated with the material would reflect scorching summer sunlight and reduce sticker-shock air-conditioning bills. When chilly weather sets in, the coating would change roles and transmit heat to help warm the interior.

"This is one of the most innovative and practical roofing coating materials developed to date," said Ben Wen, Ph.D., leader of the research project. He is the vice-president of United Environment & Energy LLC in Horseheads, N.Y. "This bio-based intelligent roof coating, compared with a traditional cool roof, could reduce both heating and cooling costs as it responds to the external environment. It will help save fuel and electricity and reduce emissions of volatile organic compounds from petroleum-based roofing products. In addition, it will provide a new use for millions of gallons of waste oil after it is used to cook french fries and chicken nuggets." ......... Posted by: Beverly      Read more         Source

Wed, 10 Mar 2010 09:45:46 GMT

Kennedia nigricans

It"s early March, so it"s time for my mind to drift to thoughts of visiting California for wildflowers and gardens. This photograph is from my 2008 foray, when I visited the Arboretum at the University of California Santa Cruz.

The UCSC Arboretum is famed for its extensive southern hemisphere collections. Accordingly, this vine / climber is a species from Western Australia, Kennedia nigricans, variously known as black kennedia, black coral-pea, black-bean or snakevine. As Wikipedia notes, Kennedia nigricans is a "vigorous" plant used for covering embankments or structures (and this was the case at UCSC Arboretum, where it enveloped a trellis if I recall correctly). As noted by Rodger Elliot, though, in Australian Plants Online: Australian Climbing Plants: "....it is worth considering....using climbers by letting them wander through other plants. There are many Australian climbers which are not overly vigorous which are ideal for this purpose but you need to be selective. If you try this with Kennedia nigricans, K.retrorsa or K.rubicunda you"ll find that not only will other plants in the garden be swamped but your fence may also be overcome and end up lying horizontal! I"ve seen K.nigricans kill a forest oak (Allocasuarina torulosa) just by smothering it." Given that individuals can reach at least 4m high and have a spread of 6m, it seems a species to be judiciously used in cultivated situations.

Nearly 80% of the world"s antibiotics (including antibacterials and antifungals) are derived from soil-borne bacteria, primarily from the genus Streptomyces. However, it is also known that some streptomycetes can live within plants as endophytic bacteria. Not all plant species have endophytic streptomycetes, and the minority that do typically only have one or two species. In one survey of Kennedia nigricans, though, thirty-nine species were discovered: Scanning electron microscopy of some endophytic streptomycetes in snakevine - Kennedia nigricans (Castillo et. al., 2006, doi:10.1002/sca.4950270606). Of the thirty-nine, seven were found to have antibacterial or antifungal properties. Posted by: Daniel Mosquin      Read more     Source

February 18, 2010, 9:47 PM CT

Transforming skin cells into stem cells

In an effort to sidestep the ethical dilemma involved in using human embryonic stem cells to treat diseases, researchers are in the process of developing non-controversial alternatives: In particular, they are looking for drug-like chemical compounds that can transform adult skin cells into the stem cells now obtained from human embryos. That's the topic of a fascinating article in Chemical & Engineering News (C&EN), ACS' weekly newsmagazine.

C&EN Associate Editor Sarah Everts notes that in 2006, scientists in Japan figured out a way to use genetic engineering to coax a skin cell to become a so-called "pluripotent" stem cell a type of cell that can potentially morph or change into any cell of the human body. The researchers achieved the result by infecting the skin cell with a virus containing certain genes instructing the cell to change.

Now chemists are trying to reproduce this cellular alchemy with drug-like substances because gene therapies have faced trouble getting into the clinic. Researchers are looking for chemical ways to go backward in cell development to reprogram mature cells into stem cells. Others are trying to identify substances that can morph one cell directly into other cell types for example, from a skin cell directly into a nerve cell that might treat Parkinson's disease without the use of stem cells at all. The ultimate goal is to be able to reprogram any cell of the body into another by means of a simple molecular kit, the article notes. But as chemists start putting together toolkits with these drug-like molecules, they face a number of technical hurdles as well as challenges getting acceptance from the stem cell community......... Posted by: Beverly      Read more         Source

February 18, 2010, 9:17 PM CT

Gene Associated With Endurance Running

A few minor variations in one gene may make a difference in athletic endurance, as per a newly released study from Physiological Genomics.

The study observed that elite endurance athletes were more likely to have variations of the NRF2 gene than elite sprinters. Non-elite endurance athletes were also more likely to have the genetic variations in comparison to sprinters, eventhough the difference was not as pronounced.

The study shows an association between the gene variation and endurance, but does not establish a cause-effect relationship. Future studies are needed to unravel exactly what role the gene plays in athletic performance. The study is part of a larger body of research that is exploring the human genome and which aims to understand the genetic underpinnings of athletic performance.

Eventhough the human genome is relatively uniform, there are variations among individuals. The scientists investigated the NRF2 gene because prior studies have shown that it may play a role in endurance performance because it:

• helps produce new mitochondria, a key cellular structure that produces energy
• reduces the harmful effects of oxidation and inflammation, which increase during exercise

"These findings suggest that harboring this specific genotype might increase the probability of being an endurance athlete," said one of the authors, Nir Eynon of Wingate Institute in Israel. The study, "Interaction between SNPs in the NRF2 gene and elite endurance performance," was carried out by Dr. Eynon, Alberto Jorge Alves, Moran Sagiv, Chen Yamin, Prof. Michael Sagiv and Dr. Yoav Meckel. All are at the Wingate Institute except for Alberto Alves, who is with the University of Porto in Portugal. The American Physiological Society (www.the-APS.org) published the study......... Posted by: Beverly      Read more         Source

February 3, 2010, 8:19 AM CT

magnetism's role in superconductors

Neutron scattering experiments performed at the Department of Energy's Oak Ridge National Laboratory give good evidence that, if superconductivity is correlation to a material's magnetic properties, the same mechanisms are behind both copper-based high-temperature superconductors and the newly discovered iron-based superconductors.

The work, published in a recent Nature Physics, waccording toformed at ORNL's Spallation Neutron Source (SNS) and High Flux Isotope Reactor (HFIR) along with the ISIS Facility at the United Kingdom's Rutherford Appleton Laboratory.

High-temperature superconducting materials, in which a material conducts electricity without resistance at a relatively high temperature, have potential for application to energy efficient technologies where little electricity is lost in transmission.

The research community was stirred in 2008 when a Japanese team reported high-temperature superconductivity in an iron-based material. Previously, only copper-based, or cuprate, materials were known to have those properties. The discovery elicited widespread and intense analysis of the material's structure and properties.

"The pairing up of electrons is essential for the formation of the macroscopic quantum state giving rise to superconductivity," said lead researcher Mark Lumsden of ORNL. "One of the leading proposals for the pairing mechanism in the iron-based superconductors is that magnetic interactions, provide the glue that binds the electrons together."........ Posted by: Beverly      Read more         Source