The Alchemist - January 2009

This week, The Alchemist discovers how to improve analytical chemistry by keeping things cool, how to improve anticancer therapy by lowering the dose and increasing frequency, and how to reduce lime scale in hot water appliances. Also this week a fall in air pollution has improved the life expectancy of Americans, melamine sentences have been passed in China, and pioneering global warming research earns geochemist Wallace Broecker one of the biggest cash prizes in science.

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Removing Raman’s blinkers

An international research team has circumvented the “signal-blinking” problem seen when probing a single molecule using surface-enhanced Raman scattering (SM-SERS). Jiannian Yao of the Chinese Academy of Sciences working with researchers in Sweden, has combined theory and experiment to demonstrate how cooling a molecule can eradicate the blinking that otherwise distorts the Raman picture. "It sounds straightforward," says Yao, "but this needs special consideration of the experimental set up." The team demonstrated proof of principle using the non-bonding molecule, perylene, which was physically adsorbed on colloidal silver nanoparticles.

Single molecules cooling off

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Anticancer dose

The mode of action of a whole class of anticancer drugs has been revealed by Johns Hopkins scientists. Gregg Semenza and colleagues have vindicated the high-frequency low-dose regime for anthracyclines proposed by Judah Folkman in 2000 and known as the metronomic treatment. The class includes the common anticancer agents doxorubicin, daunorubicin, epirubicin, and idarubicin, which have been used since the 1960s for treating leukemia, lymphoma, sarcomas, and carcinomas.

Semenza and colleagues investigated whether or not these drugs and inhibit the gene-activating ability of hypoxia-inducible factor, or HIF-1, which triggers blood vessel growth, angiogenesis. The team examined tumors from drug-treated mice and found that the number of blood vessels was dramatically reduced compared to controls. Additional tests revealed that the genes that HIF-1 turns on to drive blood vessel formation were turned off in tumors from the drug-treated mice.

How chemotherapy drugs block blood vessel growth, slow cancer spread

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Crystal unclear

Conventional wisdom cannot explain the intricacies of that apparently mundane material, calcium carbonate. Researchers at the Max Planck Institute of Colloids and Interfaces, in Golm near Potsdam, Germany, investigated the crystallization of calcium carbonate. They found that it forms stable nanoclusters, of a few dozen calcium and carbonate ions, in water even at low concentration, which is not how things are supposed to happen, according to the crystallization theory.

At higher concentrations, a precipitate forms. "It seems that it is already decided when the clusters form, which of the three anhydrous crystal structures calcium carbonate will assume," says team leader Helmut Coelfen. "We also observed that the crystal structure depends on the pH level." At pH just above neutral, calcite forms, but at high pH, vaterite, a non-stable crystalline structure emerges. The work has implications for reducing lime scale in domestic hot water appliances, industrial boilers, and even atmospheric and ocean carbon dioxide levels.

A crystal clear view of chalk formation

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Clean air life extension

Improvements in urban air quality across 51 cities in the US could be responsible for an average increase in lifespan of 21 weeks, and may have added almost three years for some people, according to epidemiologist Arden Pope, and colleagues at Brigham Young University, Utah. Changes in tobacco smoking habits are the biggest factor to have increased American life expectancy followed by improved socioeconomic conditions, but air quality is a major factor too, Pope and his colleagues found. "It's stunning that the air pollution effect seems to be as robust as it is after controlling for these other things," Pope said.

Cleaner air equals 21 more weeks of life

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Melamine milk

The scandal surrounding the illicit use of melamine in infant formula milk in China has come to a head this week. Hundreds of thousands of infants were poisoned by the formula milk, which was deliberately contaminated with the high-nitrogen compound melamine to spoof protein levels. At least six infants died. Compensation has now been offered to some families affected and the protagonists at the center of the controversy have been sentenced. Death sentences were served on two individuals, cattle farmer Zhang Yujun and milk trader Geng Jinping. The former boss at Sanlu, the manufacturer involved in the scandal, has been given a life sentence and a fine of almost $3 million.

Chinese milk scam duo face death

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Climatic award

Geochemist Wallace Broecker at Columbia University's Lamont-Doherty Earth Observatory has received the recently inaugurated Frontiers of Knowledge Award in Climate Change Research. At just over half a million dollars the prize is one of the biggest in science. Broecker sounded early alarms on climate change and carried out pioneering work into the interaction between the oceans and the atmosphere. One of the first mentions of the term "global warming" appeared in a paper by Broecker in the journal Science in 1975.

Wallace Broecker Wins (Yet Another) Top Prize

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-- David Bradley, Science Journalist