Researchers at the National Institute of Standards and Technology (NIST) have set the stage for building the “evolutionary link” between the microelectronics of today built from semiconductor compounds and future generations of devices made largely from complex organic molecules. In an upcoming paper in the Journal of the American Chemical Society, a NIST team demonstrates that a single layer of organic molecules can be assembled on the same sort of substrate used in conventional microchips.

The ability to use a silicon crystal substrate that is compatible with the industry-standard CMOS (complementary metal oxide semiconductor) manufacturing technology paves the way for hybrid CMOS-molecular device circuitry—the necessary precursor to a “beyond CMOS” totally molecular technology—to be fabricated in the near future.

Researchers at NIST and the Joint Quantum Institute (NIST/University of Maryland) have developed a new method for creating pairs of entangled photons, particles of light whose properties are interlinked in a very unusual way dictated by the rules of quantum physics. The researchers used the photons to test one of the fundamental concepts in quantum theory.

In the experiment, the researchers sent a pulse of light into both ends of a twisted loop of optical fiber. Pairs of photons of the same color traveling in either direction will, every so often, interact in a process known as “four-wave mixing,” converting into two new, entangled photons, one that is redder and the other that is bluer than the originals.

Only two per cent of paediatric drug trials reported that they had established independent safety monitoring committees that can help lead to the early detection of adverse drug reactions, according to a major review in the April issue of Acta Paediatrica.

Child health researchers from the University of Nottingham, UK, carried out a detailed analysis of 739 international drug trials published between 1996 and 2002 to see what safety measures were in place and to monitor the levels of adverse drug reactions.

Just under three-quarters of the trials (74 per cent) described how safety monitoring was performed during the study, but only 13 studies (two per cent) had independent safety monitoring committees.

While significant gaps remain in our total knowledge of the extent of carbon dioxide’s sources, such as fires, volcanic activity and the respiration of living organisms, and its natural sinks, such as the land and ocean, it is known that more than 30 billion tons of extra carbon dioxide (CO2) is released into the atmosphere annually by human activities, mainly through the burning of fossil fuels.

According to the latest report by the Intergovernmental Panel on Climate Change (IPCC), this increase is predicted to result in a warmer climate with rising sea levels and an increase of extreme weather conditions. Predicting future atmospheric CO2 levels requires an increase in our understanding of carbon fluxes.

Using data from the SCIAMACHY instrument aboard ESA's Envisat environmental satellite, scientists have for the first time detected regionally elevated atmospheric carbon dioxide – the most important greenhouse gas that contributes to global warming – originating from manmade emissions.

Scientists from North Carolina State University conducted larger-scale field trials and have shown that silencing a demethylase gene in burley tobacco plants significantly reduces harmful carcinogens in cured tobacco leaves.

The finding could lead to tobacco products, especially smokeless products, with reduced amounts of cancer-causing agents.

NC State's Dr. Ralph Dewey, professor of crop science, and Dr. Ramsey Lewis, assistant professor of crop science, teamed with colleagues from the University of Kentucky to knock out a gene known to turn nicotine into nornicotine. Nornicotine is a precursor to the carcinogen N-nitrosonornicotine (NNN). Varying percentages of nicotine are turned into nornicotine while the plant ages; nornicotine converts to NNN as the tobacco is cured, processed and stored.

'War is Hell' the saying goes and its stresses are great. That is why post-traumatic stress is most often associated with returning veterans of combat. But those are just the high profile cases, say a group of researchers in a new study.

The new study says a recent traumatic event is much more likely to result in post-traumatic stress disorder (PTSD) among adults who experienced trauma in childhood – and certain gene variations raise the risk considerably if the childhood trauma involved physical or sexual abuse, scientists have found.

“Untangling complex interactions between genetic variations and environmental factors can help us learn how to predict more accurately who’s at risk of disorders like PTSD. It can help us learn which prevention and treatment strategies are likely to work best for each person,” said NIMH Director Thomas R. Insel, M.D.