The Alchemist - January 2009

First story to fall under the Alchemist's gaze this week is synthetic HDL, a potential alternative therapy for cholesterol problems. Next, we hear of atomic ink that avoids the push and shove of microscopic manipulation by introducing the the nano swap meet. Bed bugs, are apparently evolving resistance to second-generation pesticides, an international team has revealed the channel-swapping mechanism, which could help chemists design alternatives. Mass spectrometry of salivary secretions, surprisingly enough, may one day off a chemical test for autism spectrum disorders while functional MRI is revealing how the female brain responds to the odor of male sweat. Finally, a rare award sees a Texan chemist honored by the AAAS.

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Synthetically good cholesterol

Forget statins, could a synthetic version of "good cholesterol" (high density lipoprotein) be the answer to fighting a problematic metabolism? Chad Mirkin and colleagues at Northwestern University working with Shad Thaxton in Northwestern's Feinberg School of Medicine have designed and built a material they refer to as a "cholesterol sponge". "Drugs that lower the bad cholesterol, LDL, are available, and you can lower LDL through [changes in] your diet, but it is difficult to raise the good cholesterol, HDL," explains Mirkin. "We are hopeful that our synthetic HDL will one day help fill this gap in useful therapeutics."

Synthetic HDL: A new weapon to fight cholesterol problems

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Atomic ink

"Conventional" atomic manipulations using a push or pull approach to drag atoms across a surface with an atomic force microscope (AFM) or other system. Now, an international team has developed a new method that involves replacing atoms on a surface with atoms on the AFM tip. The team has used an atomic "ink" composed of silicon to write its chemical symbol "Si" on a surface covered with tin atoms. This new interchange approach to atomic manipulation is much faster than previous methods and can operate at room temperature. It could be used to assemble spintronics devices for the next generation of micro circuitry.

It is possible to write with atoms using an Atomic Force Microscope

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Don't let them bite

Bed bugs are on the rampage again, despite their having been almost eradicated in the built environment. Now, John Clark of the University of Massachusetts Amherst and colleagues there and at Korea's Seoul National University have discovered how these tiny creatures, particularly those in New York City, have developed resistance to the pyrethroid neurotoxins, specifically deltamethrin, that once kept them in check. A genetic mutation that affects the animals neural membrane sodium channels means that these proteins are no longer a target for deltamethrin. In the city that never sleeps, some bed bugs are 264 times more resistant to deltamethrin than non-mutant strains. The research provides new clues for developing novel pesticides.

How Bed Bugs Outsmart Poisons Designed to Control Them

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Saliva-based autism test

Researchers in Italy have reported the discovery of abnormal proteins in the saliva of autism patients (analysed using mass spectrometry) that could eventually provide a clue for the molecular basis of this severe developmental disorder. They say that the discovery could be used as a biomarker for a sub-group of patients with autism spectrum disorders (ASD). Writing in the January 2 issue of the Journal of Proteome Research Massimo Castagnola of Rome's Catholic University and colleagues explain how two-thirds of ASD children have at least one salivary peptide that differs from those without autism. Further testing and clinical trials will be required before the test becomes available.

Study: Saliva as a clue to autism

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Eau de sweat

Denise Chen of Rice University and her colleagues have used function magnetic resonance imaging (fMRI) to investigate how the female brain responds to the chemical signals encoded in male sweat. The results of the experiment indicated the brain recognizes chemosensory communication, including human sexual sweat. The research showed that several parts of the brain are involved in processing the emotional value of the olfactory information. These include the right fusiform region, the right orbitofrontal cortex and the right hypothalamus. The study helps expand our understanding of how the human sense of smell complements our other senses, but does not confirm or refute the products offered in those pheromone-touting emails.

New study by Rice University psychologist finds women’s brains recognize, encode smell of male sexual sweat

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AAAS chemist

Chemist Montgomery "Monte" Pettitt, of the University of Houston, has been made a Fellow of the American Association for the Advancement of Science (AAAS). He is one of only three researchers in the University's history to hold this distinction, which dates back to 1874. AAAS will recognize its new Fellows on February 14 during the association's Annual Meeting, which this year takes place in Chicago. Pettitt was elected by his AAAS peers for his significant contributions to computational and theoretical chemistry, particularly in the area of the thermodynamics of aqueous solutions and the properties of biopolymers.

Chemistry professor 1 of only 3 at UH to achieve prestigious AAAS status

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-- David Bradley, Science Journalist