By switching carbon to silicon in common organic nitrogen high explosives, German chemists have created compounds that blow up on even slighter impacts.
The researchers report in Journal of the American Chemical Society that Si(CH2ONO2)4 and Si(CH2N3)4 are explosives even more sensitive than their carbon-based analogues, pentaerythritol tetranitrate (PETN) and pentaerythrityl tetraazide. The team hope this first systematic study may eventually yield stable, high-performing sila-explosives, possibly more environmentally-friendly than compounds like PETN and TNT, which generate toxic by-products.
The many faces of platinum
Researchers in the US and China have discovered how to grow multi-faceted nanocrystals of platinum, which have much higher catalytic activity than the conventional cubes, tetrahedra and octahedral nanocrystals usually used in catalysis.
The tetrahexahedral (24-faced) crystals, 81 nm across, were grown by sending alternating potential voltages through platinum spheres deposited on a carbon electrode. They are stable up to 800?C and four times more active than existing commercial catalysts for oxidising organic fuels such as formic acid and ethanol, researchers reported
Skipping the red light
Genetic mutations that cause diseases such as cystic fibrosis and Duchenne muscular dystrophy may be over-ridden by a small molecule which has shown promising results in rodent trials.
PTC124 helps ribosomes - which translate RNA into proteins - bypass faulty ’stop’ signals: nonsense errors in the genetic code which usually halt protein production.
Researchers reporting in Nature said the drug restored muscle function in rats afflicted with DMD. It is currently in Phase II clinical trials.
Clinical trials online
The World Health Organization (WHO) has set up a website allowing researchers, doctors, and patients to obtain reliable information on registered clinical trials. The online access should increase transparency, allowing searchers to find out more about different treatment options and drug side-effects.
The move follows high-profile cases of drugs whose harmful side-effects were revealed in clinical trials, such as Merck’s painkiller, Vioxx.
Initially, data from 50 000 clinical trials provided by registers in Britain, the US, and Australia/New Zealand have been put on the WHO website.
Chemists join Royal Society elite
The UK Royal Society has elected forty-four new fellows for their contributions to science, engineering and technology. Scientists on the list include Andre Geim, of Manchester University, who discovered graphene; Peter Bruce, at the University of St Andrews, for work on ionically conducting solids and their uses in fuel cells and batteries; NMR expert Malcolm Levitt, of Southampton University; Geoff Cloke, at Sussex University for his work on inorganic and organotransition metal chemistry; and polymer chemist David Sherrington, of the University of Strathclyde.
Manchester University, UK, has unveiled plans to build an unusually simple, small particle accelerator. Leader of the ?8.3 million project, Roger Barlow, said a ten-metre diameter prototype, christened Emma (Electron machine with many applications), might be completed by 2011. The accelerator uses direct current to control magnets accelerating the particles: a simpler approach, in theory, than the alternating current used by synchrotrons, though it has only now become technically feasible.
Follow that molecule!
Bacteria have had their chemical-based movement system (chemotaxis) tweaked to make them follow new molecules. US researchers reporting their re-engineering success in the Journal of the American Chemical Society suggest such technology could be used to make microbes deliver drugs to specific targets, or to chase down and degrade pollutants in soil.
The scientists didn’t alter bacterial protein sensors to detect new chemicals; instead, they used an RNA switch. This acted as a handbrake to bacterial movement unless a particular molecule was present, so the bacteria mechanically homed in on that molecule, though their proteins were not sensing it.
Nanoscales beat liquid disruption
The previously tough task of accurately weighing biological cells or nanoparticles in a liquid environment has been overcome by US scientists. Most ultra-sensitive scales depend on using a nanocantilever resonator - a tiny diving board - to measure an object’s mass as it vibrates. But fluid viscosity often disrupts this resonance. Researchers have published an alternative approach in Nature: instead of putting the resonator inside the fluid, they put the fluid inside the resonator, via a microfluidic channel carved inside the cantilever. As the whole apparatus can still be contained in a vacuum, the scientists could weigh cells to within one femtogram (10-15 g).
’Obvious’ patents denied
In a ruling with important implications for the pharmaceutical and biotech industries, the US Supreme Court has made it harder to obtain patents for inventions which are ’obvious’. In the case KSR International Co. v Teleflex Inc., the court decided that a disputed patent should not have been granted because it was a combination of pre-existing inventions: ’the product not of innovation but of ordinary skill and common sense’.
Experts said patent law based on this decision might seriously affect drugmakers who try to patent additional tweaks to their products, or small startup companies hoping to patent their researchers’ techniques. But entrepreneurs and technology companies trying to penetrate a market apparently barred by patents might be encouraged.
Deadly beetles cause bees alarm
The small hive beetle, which invades colonies of the European honeybee, relies on the bee’s own chemical alarm signal - the pheromone isopentyl acetate (IPA) - to congregate on troubled beehives, US researchers have found. Publishing in Proceedings of the National Academy of Sciences, they report that the beetles are, surprisingly, even more sensitive to IPA than the bees.To make things worse, the beetle spreads its own fungus which releases more IPA, calling other beetles to the site. European honeybees are often forced to abandon their hives in the face of overwhelming infestation from beetle larvae; but African honeybees seem to be less susceptible, though researchers do not yet know why.
US chemical costs stress companies
A survey of 165 US chemical manufacturers has shown companies generally agree that chemical costs are rising, while domestic chemical availability will decrease. A quarter of companies surveyed by the Boston-based consulting firm AMR research said they would move about a third of their chemical production offshore unless the situation improved.
The main problem, the report noted, was the rising costs of US natural gas compared to other parts of the world. For example, Dow Chemical spends $12 billion a year in energy costs in the US; if all its plants moved to Germany, it would spend $7 billion a year; and in the Middle East, $1.5 billion a year.
Though 80 new large-scale chemical plants are planned around the world, none will be built in the US, said the report, commissioned by the US National Association of Manufacturers.
Plastics farms go commercial
German chemical giant BASF has taken another step toward starting commercial production of biopolymers for making plastics (see Chemistry World, August 2006, p36) announcing that it is financing research at Graz University of Technology, in Austria, to determine the feasibility of large-scale production. Global agricultural processor Archer Daniels Midland has already invested, forming a joint venture with Massachusetts-based bioscience firm Metabolix. In April, the two firms announced that their joint venture, called Telles, would build a 50 000 tonne production plant in Iowa, which would begin producing plastics under the trade name Mirel, by 2008.
New HIV blocker prepares for trials
German scientists say a natural component of human blood which defends against the HIV-1 virus will begin to be tested in Phase I clinical trials by the end of this year. The broad-based protein inhibitor, whose discovery was reported in Cell, had its potency markedly enhanced with a few amino acid alterations, and was effective against drug-resistant HIV strains. The trials, at Hannover Medical School, will be directed by German biotech firm
Folic acid backed for bread
The UK Food Standards Agency (FSA) has recommended that bread or flour should, by law, be fortified with folic acid. A lack of folic acid during pregnancy has been linked to disabilities in babies, including spina bifida, while countries such as the US, Chile and Canada already add folic acid to bread. But critics worry the supplement may harm the elderly, as it can mask symptoms of anaemia caused by vitamin B12 deficiency.
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