Applied Physics

Researchers at Duke University's Pratt School of Engineering have uncovered a missing link in scientists' understanding of the physical forces that give DNA its famous double helix shape.

"The stability of DNA is so fundamental to life that it's important to understand all factors," said Piotr Marszalek, a professor of mechanical engineering and materials sciences at Duke. "If you want to create accurate models of DNA to study its interaction with proteins or drugs, for example, you need to understand the basic physics of the molecule. For that, you need solid measurements of the forces that stabilize DNA."

A semiconductor membrane designed by researchers at the University of Illinois could offer more flexibility and better electrical performance than biological membranes. Built from thin silicon layers doped with different impurities, the solid-state membrane also could be used in applications such as single-molecule detection, protein filtering and DNA sequencing.

“By creating nanopores in the membrane, we can use the membrane to separate charged species or regulate the flow of charged molecules and ions, thereby mimicking the operation of biological ion channels,” said lead researcher Jean-Pierre Leburton, the Stillman Professor of Electrical and Computer Engineering at Illinois.

A multi-institutional consortium including Duke University has created startlingly crisp 3-D microscopic views of tiny mouse brains -- unveiled layer by layer -- by extending the capabilities of conventional magnetic resonance imaging.

"These images can be more than 100,000 times higher resolution than a clinical MRI scan," said G. Allan Johnson, Duke's Charles E. Putman Distinguished Professor of radiology and professor of biomedical engineering and physics.

These animated micro-CT based images show the moving blood in the left ventricle (LV) of a mouse heart during one heartbeat. The temporal resolution is 10 ms and the spatial resolution is 100 microns on all axes.


Scientists' hunt for the cause of depression has implicated so many suspects and found so many treatments with different mechanisms that the condition remains an enigma. Now researchers at the Stanford University School of Medicine have identified one unifying principle that could explain how a range of causes and treatments for depression converge.

They found that in rats the differing mechanisms of depression and its treatment in the end appear to funnel through a single brain circuit. Changes in how the electrical signals spread through the circuit appear to be the cause of depression-related behavior, according to their study.

A generator that is 10 times more powerful than any other similar devices has been developed by engineers at the University of Southampton.

Dr Steve Beeby and his team at the University's School of Electronics & Computer Science (ECS) have developed a kinetic energy generator which generates electrical energy from the vibrations and movements present within its environment.

Blood vessels that have been tissue-engineered from bone marrow adult stem cells may in the future serve as a patient's own source of new blood vessels following a coronary bypass or other procedures that require vessel replacement, according to new research from the University at Buffalo Department of Chemical and Biological Engineering.

“Our results show that bone marrow is an excellent source of adult stem cells containing smooth muscle and endothelial cells, and that these stem cells can be used in regenerative medicine for cardiovascular applications,” said Stelios T. Andreadis, Ph.D., associate professor in the UB Department of Chemical and Biological Engineering in the School of Engineering and Applied Sciences.

Surgical instruments or implants that are contaminated with residual bacteria, or pyrogens, can cause blood poisoning in patients. Researchers are developing a test that imitates the human immune system in the laboratory, eliminating the need for animal experiments.

Endoscopes and catheters are often recycled after use in a surgical operation. Various tests ensure that the devices do not jeopardize patients’ health. They must be sterile, i.e. free of living bacteria, and must not have any pyrogens attached to them. These are fever-inducing residues of fungi or bacteria which can cause blood poisoning if they enter a patient’s bloodstream.

Anyone can buy a suit that fits - but elite geeks are going to own clothes embedded with tiny electronics that can monitor heart and respiratory functions wirelessly. After three days, whether it needs it or not, they can take it off and throw it in the wash.

At least that's the future researchers from the University of South Australia envision. They have been using integrated electronic technology to develop smart garments that, when placed on electronic hangers, enable monitored data to be downloaded in a heartbeat to a computer in your wardrobe, and then be recharged ready for wearing.

High Arctic ponds -- the most common source of surface water in many polar regions -- are now beginning to evaporate due to recent climate warming, say two of Canada’s leading environmental scientists.

John Smol (Professor of Biology at Queen’s University and holder of the Canada Research Chair in Environmental Change) and Marianne Douglas (Professor of Earth and Atmospheric Sciences and Director of the Canadian Circumpolar Institute at the University of Alberta) will publish their startling conclusions next week in the Proceedings of the National Academy of Sciences (PNAS).

“The final ecological threshold for an aquatic ecosystem is loss of water,” says Dr. Smol. “These sites have now crossed that threshold.”

For the first time, a team of experts is preparing to create tsunami in a controlled environment in order to study their effects on buildings and coastlines - ultimately paving the way for the design of new structures better able to withstand their impact.

Dr Tiziana Rossetto, UCL Department of Civil & Environmental Engineering, unveiled plans to develop an innovative new tsunami generator capable of creating scaled-down versions of the devastating waves. The UCL team will be working with marine engineering specialists HR Wallingford (HRW) throughout the project.

“Tsunami are water waves generated by earthquakes, underwater landslides, volcanic eruptions or major debris slides,” said Dr Rossetto.