Science – Page 302 – David Bradley

Pro Active Health and Diet

Catching up with the Sunday supplements two ads caught my eye. The first was for Flora pro.activ, which contains dairy peptides and supposedly is proven to help control blood pressure and maintain a healthy heart. The second was for Sirco, which is apparently approved by Heart UK and is supposed to “naturall” thin the blood to help improve its flow. On the same day, I read a BBC news item telling us that eating oily fish isn’t as good for us as we had been led to believe. Also in the mail that day was a reprint from by friend Bradford Frank (an MD at the University of Buffalo School of Medicine), his paper [Ann Clin Psyc, 2005, 17(4), 269-286] reviewed the various antioxidants and stacked up the evidence for which are any good at reducing the risk of developing Alzheimer’s disease. Seemingly, aged garlic extract, curcumin, melatonin, resveratrol, Gingko biloba extract, green tea, and vitamins C & E all have a strong association with a reduced risk of AD. On the other hand, acetyl-L-carnitine, alpha-lipoic acid, bacopa monniera, ferulic acid, and ginseng are only very weakly associated with any reduction in risk. Huperzine A, adds Frank, falls into a special category as this compound actually inhibits the very enzyme that AD drugs target – acetylcholinesterase (AChE).

So, what is one to make of all these various pieces of information. It seems to me that far too much effort is spent on trying to augment the healthy balanced diet we should all aspire to, but more importantly, all these various threads seem to suggest that exercise and mental activity play no role in protecting us from disease. The people who buy pro-activ and Sirco, and those who pop dozens of different antioxidants, trace elements, and vitamins might hope to live forever, but with the impending threat of emerging viral disease and nuclear terrorists, a splash of Sirco or a handful of Gingko leaves is probably not going to help.

Missing Bio Link

The missing piece in the biochemistry of haem (heme) is reported in this week’s spectroscopyNOW. Japanese researchers have used x-ray diffraction to determine the crystal structure of the enzyme human indoleamine 2,3-dioxygenase (IDO). This crucial enzyme splits the pyrrole ring of the amino acid L-tryptophan and incorporates both atoms of a molecule of oxygen, an essential step in dozens of metabolic reactions. The discovery could have implications for other studies involving this enzyme and medical problems with which it is associated.

Swell Gels

In my latest news round-up on spectroscopynow, we report on new materials based on cross-linking polymers have been shown to swell and contract in a controlled way depending on temperature an pH. The researchers used various analytical techniques to track the syntheses of these materials and their behaviour, including proton NMR, XPS (X-ray photoemission spectroscopy), and Fourier transform infrared spectroscopy.

Such smart gels may have applications in tissue engineering and drug delivery.

A Logical View of Enzymes

David Bradley reports in this week’s SpectroscopyNow on how scientists in Israel are using UV-Vis spectroscopy to track the underlying logic of enzyme systems that compute.

The research could lead ultimately to implantable enzyme-based computers that respond to metabolic changes in the body and allow complex drug therapies to be monitored and controlled.

Speedy Molecular Movements

High-speed observations of hydrogen ions (protons) moving within a molecule could allow chemists to gain new insights into the fundamental processes that take place in reactions, according to UK scientists writing in the journal Science today.

John Tisch of Imperial College London and his colleagues have captured proton movements on the attosecond scale. (Check out our atto to yocto page for a definition). The research provides new clues as to how molecules behave in chemical and biological processes.

“Slicing up a second into intervals as miniscule as 100 attoseconds, as our new technique enables us to do, is extremely hard to conceptualise,” says Tisch, “It’s like chopping up the 630 million kilometres from here to Jupiter into pieces as wide as a human hair.”

Jon Marangos, Director of the Blackett Laboratory Laser Consortium at Imperial, adds that the new technique means scientists will now be able to measure and control the ultra-fast dynamics of molecules. “Control of this kind underpins an array of future technologies, such as control of chemical reactions, quantum computing and high brightness x-ray light sources for material processing. We now have a much clearer insight into what is happening within molecules and this allows us to carry out more stringent testing of theories of molecular structure and motion. This is likely to lead to improved methods of molecular synthesis and the nano-fabrication of a new generation of materials,” explains Marangos.

To make the breakthrough, the scientists, include lead author Sarah Baker, used a specially built laser system capable of producing extremely brief bursts of light. This pulsed light has an oscillating electrical field that exerts a powerful force on the electrons surrounding the protons, repeatedly tearing them from the molecule and driving them back into it. This process causes the electrons to carry a large amount of energy, which they release as an x-ray photon before returning to their original state. How bright this x-ray is depends on how far the protons move in the time between the electrons’ removal and return. The further the proton moves, the lower the intensity of the x-ray, allowing the team to measure how far a proton has moved during the electron oscillation period.

You can read more about the research in today’s issue of Science

Benzene in the London Times

Benzene Ring UK paper the Times today picked up on the benzene in soft drinks problem I mentioned in sciencebase on February 22.

The paper reports how the Food Standards Agency has found levels of benzene (“six parts carbon, six parts hydrogen”) at eight times the level permitted in drinking water in samples from some 230 drinks on sale in Britain and France.

What’s more interesting than this finding, eight times a miniscule amount remains a miniscule amount, is that the paper lists several sources of benzene to which we might be exposed. It is, says reporter Rajeev Syal, It is produced during incomplete combustion of carbon-rich substances: “produced from petrochemicals, but occurs naturally in volcanoes, forest fires and in cigarette smoke. Volcanologists, forestry firefighters, and smokers should be listed among those banned from worrying about their being too much benzene in their cola, bottled water, or ‘fruit’ drink.

Regardless of the actual hazards involved, what’s the betting that benzene in soft drinks will displace fears of bird flu, in the UK, for at least a couple of weeks. It might just be long enough to keep the media fed until all those ducks have flown the coop, as it were…

You can read The Times’ article (here).

Spectral Lines

The latest news round-up science news at spectroscopyNOW from David Bradley is now available online. Read about how Crystallography finds missing piece of haem puzzle, Computing enzymes, The inside story of rocks and fossils, Portable IR lays David’s surface bare, Swell idea for medicine, Electronic speed camera; all the latest spectroscopy news and more.

While you’re there you can grab a free subscription to spectroscopy magazine too.

Scurrying Salamanders

TL:DR – Short news article from 2006 about salamanders. The headline alludes to a lyric from a song by the band Genesis, The Carpet Crawlers.

Salamanders can transform from an aquatic juvenile form into their terrestrial, adult form only if the stream bed on which they develop is of the right nature. A study published today in the journal BMC Biology reveals that the Oklahoma salamander Eurycea tynerensis metamorphoses into a terrestrial adult form in streambeds composed of fine, tightly packed gravel but stays in the juvenile form in loosely packed streambeds composed of large particles.

The study by Ronald Bonett and Paul Chippindale from the University of Texas at Arlington, Texas, USA, exemplifies how small habitat differences can influence developmental patterns and morphology, they also suggest that such microstructure changes could influence a species’ evolution too.

Bonett and Chippindale explain that large gravel creates porous streambeds with large spaces between particles, where aquatic paedomorphic salamanders can access sub-surface water during dry months. However, if these spaces are filled in by small particles, metamorphosis is the only way they can survive when surface streams dry-up.

The Inner Secrets of Rocks and Fossils

Researchers at UCLA have produced the first 3D images of fossils embedded in rocks aged between 650 and 850 million years old. New microscopy and spectroscopy techniques allowed them to sneak an interior peek inside ancient rocks without having to crack them open. The research allows them to spot signs of ancient microscopic life, such as fossil cell walls and could be useful in studying extraterrestrial rocks in the search for alien life.

Dig inside the full story in David Bradley’s news page on spectroscopynow.com

Electronic Speed-trap

A speed-trap for electrons joyriding through single crystals based on MRI can reveal their velocities and produce an image showing an electron density map of the electrons in the crystal. In a kind of cold-case re-opened, the technique provides new evidence to show that the electrons are not breaking Ohm’s law.

Noam Kaplan of the Hebrew University in Jerusalem and colleagues M Drescher and E Dormann at Karlsruhe University, Germany, have developed a technique to measure electron velocity, separate from the electric current flowing through the material. Current is analogous to measuring the number of cars that pass a speed trap rather than the velocity of individual vehicles. The team used MRI, not to produce an image, but to detect electrons simply by monitoring their spin. To measure electron velocity, however, they scanned the crystal, a radical cation salt, with no current flowing.

You can find out what their experiments revealed in David Bradley’s latest news round-up on spectroscopynow.com