Category Health/Medical

DNA arrays change shape in response to an external trigger. Credit: Yonggang Ke

They look like security gates, but change shape in a cascade. Biomedical engineers have built simple machines out of DNA, consisting of arrays whose units switch reversibly between two different shapes. The arrays’ inventors say they could be harnessed to make nanotech sensors or amplifiers. Potentially, they could be combined to form logic gates, the parts of a molecular computer. The DNA machines can relay discrete bits of information through space or amplify a signal, says Yonggang Ke, PhD, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory.

“In the field of DNA-based computing, the DNA contains the information, but the molecules are floating aroun...

Two Aplysia sensory neurons with synaptic contacts on the same motor neuron in culture after isolation from the nervous system of Aplysia. The motor neuron has been injected with a fluorescent molecule that blocks the activity of a specific Protein Kinase M molecule. Credit: Schacher Lab/Columbia University Medical Center

Different types of memories stored in the same neuron of the marine snail Aplysia can be selectively erased, according to a new study by researchers at Columbia University Medical Center (CUMC) and McGill University. The findings suggest that it may be possible to develop drugs to delete memories that trigger anxiety and post-traumatic stress disorder (PTSD) without affecting other important memories of past events.
During emotional or traumatic events, multiple memories ...

Highlights
•Enterochromaffin (EC) cells are excitable and express voltage-gated ion channels
•EC cells use sensory receptors to detect irritants, metabolites, and catecholamines
•EC cell activation leads to voltage-gated Ca2+ channel-dependent serotonin release
•EC cells modulate sensory nerves via serotonin receptors and synaptic connections

Cells that alert nervous system to intestinal trouble could provide new target for gastrointestinal treatments. Specialized cells in the gut sense potentially noxious chemicals and trigger electrical impulses in nearby nerve fibers, according to a new study led by UC San Francisco scientists. “These cells are sensors, like a window looking into the contents of the gut,” said James Bayrer, MD, PhD, an assistant professor of pediatrics at UCSF.

Usin...

Versatile Barometer Biosensor Based on Au@Pt Core/Shell Nanoparticle Probe

When it comes to testing for cancer, environmental pollution and food contaminants, traditional sensors can help. The challenges are that they often are bulky, expensive, non-intuitive and complicated. Now, one team reports in ACS Sensors that portable pressure-based detectors coupled with smartphone software could provide a simpler, more affordable alternative while still maintaining sensitivity.

Current disease and contamination sensors require expensive readout equipment or trained personnel. Yuehe Lin, Yong Tang and colleagues propose a new detection system based on pressure changes...