Tag Archives: diameter

Computer modeling shows crucial function of water molecules in proteins

Using molecular simulations that modeled a potassium channel and its immediate cellular environment, atom for atom, UChicago scientists have discovered that just 12 molecules of water cause the long post-activation recovery period required by such ion channels before they can function again. The research has revealed a new mechanism in the function of a nearly universal biological structure that will have broad implications, ranging from fundamental biology to the design of pharmaceuticals.

“Our research clarifies the nature of this previously mysterious inactivation state. This gives us better understanding of fundamental biology and should improve the rational design of drugs, which often target the inactivated state of channels,” said Benoît Roux, professor of biochemistry and molecular biology, whose team’s findings were published online July 28 in Nature. (more…)

Read More

Spiral galaxies like Milky Way bigger than thought, says CU-Boulder study

Let’s all fist bump: Spiral galaxies like our own Milky Way appear to be much larger and more massive than previously believed, according to a new University of Colorado Boulder study by researchers using the Hubble Space Telescope.

CU-Boulder Professor John Stocke, study leader, said new observations with Hubble’s $70 million Cosmic Origins Spectrograph, or COS, designed by CU-Boulder show that normal spiral galaxies are surrounded by halos of gas that can extend to over 1 million light-years in diameter. The current estimated diameter of the Milky Way, for example, is about 100,000 light-years. One light-year is roughly 6 trillion miles. (more…)

Read More

UMass Amherst Nuclear Physicist, with Hundreds Worldwide, Tracks Huge Magnetic Ring across Country for Muon Experiments

Massive device to travel by barge and truck this summer

AMHERST, Mass. – Nuclear physicist David Kawall at the University of Massachusetts Amherst is among scientists from 26 institutions worldwide who are waiting patiently for an electromagnet 50 feet in diameter to be transported from New York to Illinois, where they plan to launch an experiment in 2016 that could open new realms of particle physics.

Kawall’s responsibility will be to measure very precisely the magnetic field inside the ring-shaped magnet when it arrives at its new home sometime in late July. “It’s definitely new territory,” he says, “because we need to measure the field accurately to 70 parts per billion in this huge magnet. The payoff is enormous, however, because we expect the new experiment to yield results four times more precise than the previous effort was able to attain.” (more…)

Read More

A Cyclotron’s Long Journey Home

One of the world’s first working circular particle accelerators returns to Berkeley Lab—75 years later.

Seventy-five years after one of the world’s first working cyclotrons was handed to the London Science Museum, it has returned to its birthplace in the Berkeley hills, where the man who invented it, Ernest O. Lawrence, helped launch the field of modern particle physics as well as the national laboratory that would bear his name, Lawrence Berkeley National Laboratory.

On Jan. 9, 1932 the brass cyclotron—which measures 26 inches from end to end and whose accelerating chamber measures just 11 inches in diameter—was successfully used to boost protons to energies of 1.22 million electron volts. Its return to Berkeley Lab caps a decades-long saga in which various parties endeavored to secure the cyclotron’s return from London, but the persistence of Pamela Patterson, who chronicles Berkeley Lab’s history as managing editor of its website, finally paid off. (more…)

Read More

New Coal Technology Harnesses Energy without Burning, Nears Pilot-Scale Development

COLUMBUS, Ohio — A new form of clean coal technology reached an important milestone recently, with the successful operation of a research-scale combustion system at Ohio State University. The technology is now ready for testing at a larger scale.

For 203 continuous hours, the Ohio State combustion unit produced heat from coal while capturing 99 percent of the carbon dioxide produced in the reaction. (more…)

Read More

Graphene Membranes May Lead To Enhanced Natural Gas Production, Less CO2 Pollution, Says CU Study

Engineering faculty and students at the University of Colorado Boulder have produced the first experimental results showing that atomically thin graphene membranes with tiny pores can effectively and efficiently separate gas molecules through size-selective sieving.

The findings are a significant step toward the realization of more energy-efficient membranes for natural gas production and for reducing carbon dioxide emissions from power plant exhaust pipes.

Mechanical engineering professors Scott Bunch and John Pellegrino co-authored a paper in Nature Nanotechnology with graduate students Steven Koenig and Luda Wang detailing the experiments. The paper was published Oct. 7 in the journal’s online edition. (more…)

Read More

Scientists Measure Diameter of The Sun With Unprecedented Accuracy

A group of scientists from Hawaiʻi, Brazil and California has measured the diameter of the Sun with unprecedented accuracy by using a spacecraft to time the transits of the planet Mercury across the face of the Sun in 2003 and 2006.

The measurements of the Sun’s size were made by University of Hawaiʻi at Mānoa Institute for Astronomy scientists Drs. Marcelo Emilio (visiting from Ponta Grossa, Brazil), Jeff Kuhn and Isabelle Scholl in collaboration with Dr. Rock Bush of Stanford University. They used the Michelson Doppler Imager (MDI) aboard NASA’s Solar and Heliospheric Observatory (SOHO) to make the measurements. (more…)

Read More

Researchers Make Living Model of Brain Tumor

*Researchers have created a living 3-D model of a brain tumor and its surrounding blood vessels. In experiments, the scientists report that iron-oxide nanoparticles carrying the agent tumstatin were taken by blood vessels, meaning they should block blood vessel growth. The living-tissue model could be used to test the effectiveness of nanoparticles in fighting other diseases. Results appear in Theranostics.*

PROVIDENCE, R.I. [Brown University] — Brown University scientists have created the first three-dimensional living tissue model, complete with surrounding blood vessels, to analyze the effectiveness of therapeutics to combat brain tumors. The 3-D model gives medical researchers more and better information than Petri dish tissue cultures.

The researchers created a glioma, or brain tumor, and the network of blood vessels that surrounds it. In a series of experiments, the team showed that iron-oxide nanoparticles ferrying the chemical tumstatin penetrated the blood vessels that sustain the tumor with oxygen and nutrients. The iron-oxide nanoparticles are important, because they are readily taken up by endothelial cells and can be tracked by magnetic resonance imaging. (more…)

Read More