Thursday, October 23 2014

Cheating on physics provides great microscopes and three Nobel Prizes

Classification: Sciences @ 07:55:02

This year’s Nobel Prize in Chemistry honors an interesting mix of developments. It honors three researchers who overcame an apparent physical limitation in our ability to image microscopic objects, in the process building microscopes that are proving to be incredibly useful for biology. But because the breakthroughs depended in part on our understanding of the behavior of individual molecules, the prize comes in chemistry.

The limit in question is the diffraction limit, first described back in the 1800s by Ernst Abbe. This limit means that the best resolution we can obtain in imaging an object is half the wavelength of the light we’re using to image it. If we’re using visible wavelengths, this means we can’t do much better than about 250nm (a distance that dwarfs viruses and individual proteins). Although lots of improvements in microscopy have been made since the 1800s, all of them kept running into diffraction-related problems.

At least, that was the case until recently. The Nobel Prize honors not one but two distinct ways of overcoming the limit. (Conveniently, we have coverage of both-see the sidebar.) In the case of one of the recipients, it honors an idea that came to him when he had given up on research and was working in the family business.


Tuesday, October 14 2014

Will Pluto be reinstated as a planet?

Classification: Insolite,Sciences @ 08:02:09

There were once nine planets. Everyone learned them, sometimes aided by a mnemonic: “My Very Excellent Mother Just Sent Us Nine Pizzas.” But back in 2006, the International Astronomical Union (IAU), arbiter of what is and what isn’t a planet, stripped Pluto of its status, saying it was too small to pack sufficient gravitational punch. It was downgraded to a new, second-class status: “dwarf planet.” So then there were eight: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, or “My Very Excellent Mother Just Served Us Nachos.”

The decision did not sit well with the public. Some amateur stargazers and some astronomers thought it rather arbitrary. As the Harvard-Smithsonian Center for Astrophysics put it in a press release, “a dwarf fruit tree is still a small fruit tree, and a dwarf hamster is still a small hamster.” (more…)

Friday, October 10 2014

Strong underwater adhesives made by self-assembling multi-protein nanofibres

Classification: Sciences @ 08:27:50

Adhesives that can form bonds underwater would be useful for many biomedical applications, yet few synthetic adhesives exist today. In the last decade, researchers have begun to look to the sea to investigate the organisms-mussels, barnacles, algae, and others-that naturally secrete durable underwater adhesives. Recently, scientists have successfully developed adhesives that are able to mimic their biological counterparts.

There are two natural protein systems that have been widely investigated thus far. One uses a chemical called 3,4-dihydroxyphenylalanine (DOPA) that links proteins together-we’ll call this the sticky part. (more…)

Monday, April 21 2014

Flowing salt water over graphene generates electricity

Classification: High-Tech,Sciences @ 16:32:33

Hydroelectricity is one of the oldest techniques for generating electrical power, with over 150 countries using it as a source for renewable energy. Hydroelectric generators only work efficiently at large scales, though-scales large enough to interrupt river flow and possibly harm local ecosystems. And getting this sort of generation down to where it can power small devices isn’t realistic.

In recent years, scientists have investigated generating electrical power using nano-structures. In particular, they have looked at generating electricity when ionic fluids-a liquid with charged ions in it-are pushed through a system with a pressure gradient. (more…)

Friday, March 28 2014

Total Synthesis of a Functional Designer Eukaryotic Chromosome

Classification: Sciences @ 09:44:05

Synthetic biology has come a long way in recent years. In the last two decades alone, scientists have been able to go from synthesising the genome of a relatively small virus, Hepatitis C, to creating what researchers refer to as the “first synthetic cell” from a unicellular organism.

Yet until recently, researchers had been incapable of constructing one of the most emblematic symbols of our own genetic makeup: the eukaryotic chromosome. Now, a team of scientists has announced that the age of the synthetic chromosome is upon us, as a study published in Science reveals how the group was able to construct a yeast chromosome from scratch.

Although scientists have previously been able to construct viral DNA and bacterial DNA, the synthesis of a eukaryotic chromosome had not been achieved. So, when the scientists decided to generate a chromosome from scratch, they knew they had to plan it out carefully. (more…)

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