Month: November 2006

Alexander Litvinenko Dead

Former Russian spy, defector, and activist-writer Alexander Litvinenko has died in a London hospital of suspected poisoning with radioactive thallium. [Subsequently, found to have been polonium]

Litvinenko’s friend Alexander Goldfarb read a statement prepared by the former spy on his deathbed just two days before he passed away. In that statement, Litvinenko lays the blame for his poisoning firmly at the feet of Russian President Vladimir Putin and says: “You may succeed in silencing me, but that silence comes at a price,” according to news reports, “You have shown yourself to be as barbaric and ruthless as your most hostile critics claim.

The Russian government has declared the claims as preposterous and suggests that infighting among Russians living in London is more likely to have led to Litvinenko’s death.

Preliminary post-mortem results suggest that a radioactive material – possibly a large dose of radioactive polonium-210 – may have been associated with his death. In our earlier report, it was suggested that thallium, then radioactive thallium, may have been implicated. Whether or not Litvinenko ingested this material was exposed to it in the environment is not yet known raising serious public safety concerns.

A UK press conference held this afternoon provided more information.

Science Experiments More Test-tube than Youtube

Science experiments videoEver wanted to observe the dissection of fruitfly ovaries but were too squeamish? What about monitoring actin disassembly with time-lapse microscopy, not sure how it’s done? Maybe you have been wondering how to freeze human embryonic stem cells but were afraid to ask…

Don’t worry the online Journal of Visualized Experiments has come to the rescue of cash-strapped demonstrators with little spare time who can now call on a video of a growing number of biological experiments that can show how a particular procedure should best be carried out.

The journal’s site, MyJove.com, has a rather different modus operandi to Youtube, but nevertheless provides almost instant access to a searchable database of scientific “how-to” videos as well as allowing research assistants and others to submit their own (No Brainiacs please!). In truth, that’s where the similarity with Youtube ends, JOVE has a fully fledged editorial board and presumably reviewers to carry out the peer review process required of almost every academic journal, online or not.

The site’s raison d’etre is spelled out in its About page – “As every practicing biology researcher knows, it takes days, weeks or sometimes months and years to learn and apply new experimental techniques. It is especially difficult to reproduce newly published studies describing the most advanced state-of-the-art techniques. Thus, a major part of the PhD and post-doctoral training in life sciences is devoted to learning laboratory techniques and procedures.”

“Video-based visualization of biological techniques and procedures provide an effective solution to the problem described.”

And, for those of us not training in a biological research lab, we get to see what these guys spend their time on. Embed code, allows other sites to more effectively link to specific videos.

Be warned, though some of these videos are long and will buffer only slowly on a narrow bandwidth internet connection.

As part of the Learn with Sciencebase project, I’ve added a Top Ten Science Videos page to the site.

Genetic Variation on a Theme

What does it mean to be human? We thought that the Human Genome Project had set the limites on the genetic make-up of our species. But, according to Steve Connor, writing in the Independent today, much of the genetic variation between individuals can best be explained by the presence of multiple copies of certain key genes rather than variations in the genome sequence.

The research suggests that whereas previously we thought all people shared 99.9% of their DNA, it could be that two individuals can differ by ten times that. The research has important implications for our understanding of inherited traits and genetic disease.

The findings appear in three simultaneous papers in three leading science journals, including Nature and were reported by teams from thirteen different research centres in the UK and the US.

Alchemists, crucibles and chemistry

AlchemistWhat alchemist’s den would be complete without a crucible? The tough little vessels used for mixing all those odd ingredients, goat urine, cow’s blood, sweat, philosopher’s wool, saltpeter etc etc…

Now, the 500-year old mystery of how crucibles could survive all that chemical punishment and high temperatures has been revealed by archaeologists at University College London and Cardiff University.

Earlier research had demonstrated that the crucibles are found in archaeological sites across the world, including Scandinavia, Central Europe, Spain, Portugal, the UK, and even colonial America. Many researchers have tried to reproduce these vessels but have always failed.

Now, writing in Nature, the researchers reveal using petrographic, chemical and X-ray diffraction analysis that Hessian crucible makers made use of an advanced material only properly identified and named in the 20th century.

Marcos Martinón-Torres explains, “Our analysis of 50 Hessian and non-Hessian crucibles revealed that the secret component in their manufacture is an aluminium silicate known as mullite (Al6Si2O13). Today mullite (not to be confused with mullet) is used in a wide range of modern conventional and advanced ceramics, such as building materials, electronic packaging devices, optical materials and catalytic converters, as well as in ceramic matrix composites such as thermal protection systems and liners for aircraft and stationary gas turbine engines.

Mullite was only described in the 20th century although the makers of crucibles were exploiting its properties almost half a millennium ago. It was produced by firing a crucible made from kaolinitic clay to above 1100 degrees.

Mullite is extremely resistant to heat, chemical and mechanical stresses, making it perfect for the Alchemist’s den. It is thanks to the availability of Hessian crucibles that the discoveries of several chemical elements and their thermochemical behaviour took place.

‘Crucible makers were not aware of mullite, but they mastered a very successful recipe, and that’s why they kept it constant, and secret, for centuries.’

Technological whirlwind

Best of Technology WritingFancy a whirlwind tour of some of the best technology writing of the year? As part of the digitalculturebooks series from the University of Michigan Press, Brendan Koerner has compiled some of the most stimulating and fascinating feature articles from the web and print media by the likes of the NYT’s David Bernstein, New Republic’s David Bell, Mike Daisy on Slate, Dan Ferber in Popular Science magazine, and many more.

The subjects covered are incredibly diverse, covering search engines, wikis and online social networking to the quest for a personal jet pack and the invention of the karaoke machine (which has apparently made it’s inventor not one Yen).

This neat little tome offers a grand over view (as well as a whirlwind tour!) of most technological niches you care to mention and highlights just how amazing human tool-making has become. Even for the tech-savvy reader it springs quite a few surprises.

Koerner is a contributing editor for Wired (which means he writes for the magazine and has his name on the masthead, I presume), a columnist for the NYT and Slate.

In the world of technology the pace is fast and the stakes are high. Jump into that whirlwind and prepare to be inspired.

Best of Technology Writing 2006 is available from Amazon.com, of course.

What is Thallium

Thallium poisoningA former colonel in the FSB (the successor to the KGB) has allegedly fallen foul of chemistry. Alexander Litvinenko, 43, a vocal critic of Russian President Vladimir Putin, fell ill on November 1, after a meeting in a London sushi bar, reports the BBC.

Litvinenko is on life support in University College Hospital having allegedly been poisoned with a potentially lethal dose of the heavy metal thallium polonium. His condition is apparently serious but stable and he is under 24-hour armed surveillance. The BBC claims that his condition could be the work of the Russian Secret Service. Thallium (nor polonium) is certainly not available “over-the-counter” to the general public.

The alleged assassination attempt is revealed just as the British secret services try to exploit the marketing of the new James Bond movie – Casino Royale, starring Daniel Craig in the role of 007 – to recruit new spies. One British agent told BBC Radio 1 listeners that the secret services always work within the law and there is no license to kill. This thallium polonium attack comes in the wake of the gunning down in Moscow of journalist Anna Politkovskaya in October 2006 and perhaps does suggest that someone, somewhere does have a license to kill.

But, what exactly is thallium and why is it poisonous?

Thallium, Tl, is the element with atomic number 81 and lies just below indium in the periodic table (same column as boron, aluminium, and gallium). It’s tasteless, colourless, and odourless and would be undetectable if sprinkled into food or a drink in a restaurant.

Thallium ions have the same charge and are approximately the same size as potassium ions. As such, they can reach most tissues including the tissues of the central nervous system (CNS). Like other heavy metals, it binds to sulfydryl groups in the body disturbing numerous biochemical processes.

If you’re an ex-spy worried about meeting former colleagues in London sushi bars, you might be well advised to carry some D-penicillamine and Prussian blue with you. This combination can act as an effective antidote to thallium poisoning because these compounds have a greater affinity for the metal than the sulfhydryl compounds in your blood.

Lock up the cat for safer drugs

stereoselective catalystCanadian and Korean chemists have locked in a form of handedness into a common catalytic molecule that could make it useful for separating the building blocks of proteins, amino acids, into their chiral forms for biotech applications and drug development. The new locked up cat, might also be used to make purer and safer chemical starting materials for reactions in the drug, agrochemicals, and polymer industries.

Jik Chin and colleagues at the University of Toronto, Canada, working with Jong-In Hong’s team at Seoul National University, Korea to synthesise a cobalt(III) complex of the ligand "salen". Salen is a commonly used ligand in organometallic chemistry. It is a Schiff base formed from a two to one reaction of derivatives of salicylaldehyde and ethylene diamine. Complexes of this ligand are very effective catalysts for a wide range of reactions including epoxidation of alkenes.

Read on…

Statistics and low GI foods

New, healthier alternatives to processed food starches with a lower GI, or glycaemic index, may soon be on the menu, thanks to scientists in China and the US. The researcher have begun to unlock the secrets of starches that make dehusked grains, potatoes, and processed foods such as biscuits and breakfast cereals less healthy compared with low GI foods. Their statistical analysis of starchy data could lead to new processed carbohydrates that do not cause the worrying blood sugar spikes associated with conventional processed starch.

Now, Hamaker and his colleagues have looked at the various physical properties of rapidly digested starches (RDS) and SDS (slowly) to try and determine the underlying differences. They have found that the degree of crystallinity of the starch content is key. Semicrystalline structure is critical to the beneficial slow digestion properties of low GI foods but cook, or otherwise process, an SDS, however, and this semicrystallinity can be lost and a once-slow starch becomes an RDS.

Read the full story in my latest news round-up on SpectroscopyNOW.com

Heart disease and the death zone

atheromaArterial plaques represent a "death zone" within the artery in which white blood cells that would otherwise clear away such fatty deposits are killed before they can do their job.

The result is that these plaques eventually reduce the blood supply to the heart causing heart problems. These plaques can break apart at any stage in a person’s life, although most commonly in middle age, whether they are otherwise fit or not.

Chinese researchers have now used analytical chemistry to determine the toxic components of arterial plaques that are so deadly to white blood cells. Their finding not only improves our understanding of this form of heart disease, but might one day lead to new approaches to treating atherosclerosis.

Find out more in the latest news from SpectroscopyNOW.com

Frothy fakers

This week in the Alchemist, I report on how platinum metal is getting all in a frothy, man… Discover that the Europeans are faking it down on the farm, and find out how regulating a man’s estrogen levels might be used to reverse prostate disease and cancer.

Also in this week’s round-up we discover how to split a beam of light for the first time albeit ever so slightly using extract of lemon juice and find that squeezing metals into your balls (buckyballs, that is) could lead to improved solar panels and new, improved MRI medical scanning.

Read all about the latest chemistry news in my Alchemist column on ChemWeb