David Bradley – Page 349

Vestigial Virgins

Ivan Pedrosa and colleagues at Harvard have demonstrated how MRI (magnetic resonance imaging) can help rule out a diagnosis of acute appendicitis during pregnancy when ultrasound results are inconclusive.

Appendicitis during pregnancy can lead to numerous complications, not least because of the need for emergency surgery. Ultrasound has been used to reveal an inflamed appendix, but it is not always conclusive, especially in the late stages of pregnancy.

The full story now in the MRI section of SpectroscopyNOW.com

Pinning Down Alzheimer Clue

US researchers have used a powerful spectroscopic technique to demonstrate that an enzyme previously shown to protect brain cells from the characteristic fibrous tangles associated with Alzheimer’s disease also helps inhibit formation of the amyloid peptide plaques (APPs) seen in this disease. The team examined the relationship between APPs and the enzyme prolyl isomerase, Pin1.

The full story is now available on the spectroscopy site – SpectroscopyNOW.com

You can access my other spectroscopy news stories via this Sciencebase page.

Broadband Comb-over

To record a useful spectrum in a reasonable time, the spectroscopist must juggle bandwidth, resolution, sensitivity, and acquisition times.

In a technique such as cavity-ringdown spectroscopy (CRDS), high detection limits are possible but this is offset by a narrowing of the range of frequencies that can be followed quickly. However, US researchers have now developed a broadband version of this technique that neatly combs over the issue of frequency limitations and can now achieve high sensitivity, broad spectral bandwidth, high resolution, and fast acquisition times simultaneously. The team reports in the journal Science a proof of principle experiment in recording CRDS spectra from the visible to near-infrared for species such as acetylene, dioxygen, water, ammonia and argon.

You can read about this latest research in the first April issue of SpectroscopyNOW. You can find more of my news reports for the spectroscopy site here.

LED printout

In the latest issue of SpectroscopyNOW, I discuss how there are numerous redox-active compounds that emit light under electrical stimulation. Such materials are commonly organometallic complexes containing a transition metal and have been developed for labelling biomolecules for use in sensors. Related compounds are also being investigated for use in luminescent displays. Now, researchers in The Netherlands have used inkjet technology to “print” thin films of such materials to make new LED devices for display and backlighting applications.

This and more in the spectroscopy news round-up. A list of my news reports for the spectroscopy site can be found here.

April Theory

A week doesn’t go by without my receiving an email from someone with a new theory that promises to overturn the whole of physics and chemistry. This week’s arrived with just a couple of days to go before April Fool’s Day.

You can check out the website along with movies illustrating the theory here. Please let me know if you get the joke! I’m not sure what those atoms are doing in that movie of two hydrogens colliding to be honest, what’s making them change direction, for instance?

Anyway, the site is here http://phasedparticle.com and I’ve reproduced the basic tenets of the new theory in case anyone can provide some insight:

1. Light is made up of both waves and particles.

2. Protons and electrons are both complete magnets having both a North and South Pole.

3. Heat is an energy field emanating from protons.

Bird Flu Vaccine

The BBC reports today that it has been given exclusive “access” to a Belgian trial of a new bird flu vaccine.

400 volunteers signed up to receive either the new vaccine or a placebo in the randomised double-blind trial of the GlaxoSmithkline vaccine. 399 said they were doing it for humanitarian reasons, one admitted it was for the money (300 euros) and the experience. Let’s just hope the “experience” isn’t as interesting as that suffered by volunteers in another recent trial for a drug that also triggers changes in the body’s immune system.

Benzene in Soft Drinks

Benzene Structure This is an update to my earlier posting about benzene in soda.

Today, March 31, the UK’s Food Standards Agency has published the results of an analytical survey of benzene levels in 150 soft drinks on the market in the UK. They state that contrary to fears, benzene was not detectable in the majority of products sampled.

However, four products did contain trace amounts of benzene that are above World Health Organization (WHO) guidelines for drinking water and the FSA has ordered these to be withdrawn. An FSA spokesman explained that while the levels of this potential carcinogen are very low it is prudent for the sake of public confidence that products that contain more than the WHO suggests is acceptable should not be sold.

The issue does not address the growing fear of risk that has become endemic in Western society, but once again reinforces the negative image of “chemicals” among consumers. This is despite the fact that one of the ingredients that leads to the benzene forming in such products in the first place is vitamin C!

The FSA spokesman adds that “The levels of benzene reported in this survey will only make a negligible impact on people’s overall exposure to benzene and so any additional risk to health is, therefore, likely to be minimal.” This should be considered in the much wider context of everyday benzene sources to which a lot of people are exposed on a daily basis, vehicle fuels and cigarette smoke, for instance.

The four drinks being withdrawn from supermarket shelves all list sodium benzoate and vitamin C (ascorbic acid) as ingredients and are: Co-op brand “low calorie bitter lemon”, Popstar “still sugar free lemon & lime drink”, Morrisons brand “no added sugar pineapple & grapefruit crush”, and Hyberry “High juice no added sugar blackcurrant squash”.

It is only certain batches of these products that contain benzene at levels above WHO guidelines, but the FSA is essentially presenting the drinks industry with an ultimatum that could see an end to a consumer issue that has been known about for at least fifteen years.

More information on the FSA report is available here.

Taking the P

Pnicogen. Silent “p” or sounded? The Oxford English Dictionary (OED) people just contacted me, wanting a definitive answer.

Partly because they found my Molecule of the Month on the subject at Paul May’s excellent site and suspected I was some kind of expert. Sadly I’m not, so I’ve resorted to asking a couple of contacts who might actually have a clue. I’d like it to be p’nuh but suspect the p should be silent, as in pneumatic. However, the OED entry currently claims otherwise, and my first contact agrees that it should be “p’ni”

Shikimic Acid Shortage Sorted

Some time ago I wrote about the possibility of a shikimic acid shortage and what science is doing to address the problem. Shikimic acid, you say? The starting material for the influenza drug Tamiflu, of course!

Microbial fermentation seemed to be the way forward, but now chemists have discovered that the seeds of the sweetgum fruit – gumballs – contain significant amounts of shikimic acid. The finding means manufacturers will not have to rely on seasonal supplies of the seeds of the star anise fruit.

Thomas Poon of the W.M. Keck Science Center at The Claremont Colleges in California who heads the team says, “Our work gives the hearty sweetgum tree another purpose, one that may help to alleviate the worldwide shortage of shikimic acid.” The findings, which could help increase the global supply of the drug, Poon told the annual meeting of the American Chemical Society, this week.

Shikimic acid is used to make a generic drug called oseltamivir (Tamiflu) which is used to fight many types of flu viruses. Some health experts believe that this and similar antiviral drugs could help save lives by slowing the spread of the virus in the absence of a bird flu vaccine, which is still in development.

Simulated Astronomical Magnetism

The strongest magnetic fields in the universe have been simulated on the computer by researchers in the UK and Germany. The fields, which are thousand million million times stronger than the magnetic field of the Earth are produced when two magnetised neutron stars collide. Theory suggests these fields could be the source of violent gamma-ray burst explosions.

Neutron stars have a mass similar to that of our Sun but are just 20 km across, which makes them denser than atomic nuclei. According to the theory of general relativity, two neutron stars orbiting each other will ultimately collide violently.

Daniel Price of the University of Exeter, UK and Stephan Rosswog from the International University of Bremen, Germany, revealed their simulations of this processat at the Royal Astronomical Society’s National Astronomy Meeting on 5th April and at the Ringberg-conference on Nuclear Astrophysics on the 7th April. The results are also published today in Science Express.

“It is only recently that we have the computing power available to model the collisions and take into account the effects of magnetic fields,” explains Price, “It has taken us months of nearly day and night programming to get this project running,” he adds. Everyday magnetic fields produced by domestic electrical products such as the pump in a refrigerator are about 100 Gauss, says Rosswog. The colliding neutron stars produce a field an incredible 10 million million times stronger.

In the supercomputer simulations, Price and Rosswog show that within the first millisecond of the collision, magnetic fields are produced that are stronger than any other magnetic field that is known in the Universe. The calculations are a computational challenge because they include a lot of exotic physics, including effects of high-density nuclear physics, particle physics and General Theory of Relativity. To calculate only a few milliseconds of a single collision takes several weeks on a parallel supercomputer.

Scientists have long suspected that such a collision may be at the heart of some of the brightest explosions in the Universe since the Big Bang, so-called short gamma-ray bursts. Recent detections of ‘afterglows’ of such bursts have confirmed this idea, but much of the physics behind these explosions still lies in the dark. (Boom, Boom!)