jjhunter

A's Avogadro
whose constant counts up one mole
he summed mass in gas

To improve Doxil’s effectiveness, Hammond’s team wanted to combine it with another type of therapy known as RNA interference (RNAi), which uses very short strands of RNA to block the expression of specific genes inside a living cell.

The researchers used a technique called layer-by-layer assembly to coat the Doxil particles with one layer of siRNA mixed with a positively charged polymer that helps to stabilize the RNA. This layer contains up to 3,500 siRNA molecules, each targeted to block a gene that allows cancer cells to pump the drug molecules out of the cells.

One of the major challenges that researchers have faced in developing RNAi as a cancer treatment is getting the particles to survive in the bloodstream long enough to reach their intended targets. To overcome this, the MIT particles include an outer coating of hyaluronic acid. These molecules absorb water, allowing the nanoparticles to flow through blood vessels undisturbed, Hammond says.

“This stealth layer becomes a cushion of water surrounding the nanoparticle, which allows it to go through the bloodstream as if it were water,” Hammond says. “That makes it circulate much more effectively.”

Jülich, 10 October 2013 – The human brain keeps changing throughout a person’s lifetime. New connections are continually created while synapses that are no longer in use degenerate. To date, little is known about the mechanisms behind these processes. Jülich neuroinformatician Dr. Markus Butz has now been able to ascribe the formation of new neural networks in the visual cortex to a simple homeostatic rule that is also the basis of many other self-regulating processes in nature. With this explanation, he and his colleague Dr. Arjen van Ooyen from Amsterdam also provide a new theory on the plasticity of the brain – and a novel approach to understanding learning processes and treating brain injuries and diseases.