Applied Physics

In the September issue of the journal Stem Cells, researchers from the Georgia Institute of Technology and Emory University write that moderate physical movement of embryonic stem cells in fluid environments, similar to shaking that occurs in the womb, improves their development and suggests that different types of movement could some day be used to control what type of cell they become. “Embryonic stem cells develop under unique conditions in the womb, and no one has ever been able to study the effect that movement has on that development process,” said Todd McDevitt, assistant professor in…

Infants and children receiving artificial heart-valve replacements face several repeat operations as they grow, since the replacements become too small and must be traded for bigger ones. Researchers at Children's Hospital Boston have now developed a solution: living, growing valves created in the lab from a patient's own cells. Pulmonary valves, which provide one-way blood flow from the heart's right ventricle into the pulmonary artery, are often malformed in congenital heart disease, putting an extra burden on the heart. "The heart valve is a complex organ," says Virna Sales, MD, a…

Airline passengers and crews who gripe about poor cabin air quality could have a new culprit to blame: the oils on their skin, hair and clothing. A new study suggests interactions between body oils and ozone found in airplane cabins could lead to the formation of chemical byproducts that might worsen nasal irritation, headaches, dry eyes and lips, and other common air traveler complaints. In simulated flights lasting four hours, American and Danish researchers placed two groups of 16 volunteers in a mockup of an airline cabin and then exposed them to varying levels of ozone and air flow,…

Scientists at MIT’s Department of Civil and Environmental Engineering and the Technion Israel Institute of Technology have for the first time recorded the entire genomic expression of both a host bacterium and an infecting virus over the eight-hour course of infection. The results of this research likely will encourage scientists in several fields to rethink their approach to the study of host-virus systems, which are believed to play a key evolutionary role by facilitating the transfer of genes between species. Professors Debbie Lindell of the Technion and Sallie Chisholm of MIT and co-…

Rice University biomedical engineers have developed a new technique for growing cartilage from human embryonic stem cells, a method that could be used to grow replacement cartilage for the surgical repair of knee, jaw, hip, and other joints. "Because native cartilage is unable to heal itself, researchers have long looked for ways to grow replacement cartilage in the lab that could be used to surgically repair injuries," said lead researcher Kyriacos A. Athanasiou, the Karl F. Hasselmann Professor of Bioengineering. "This research offers a novel approach for producing cartilage-like cells from…

Several genes with strong associations to schizophrenia have evolved rapidly due to selection during human evolution, according to researchers who found a higher prevalence of the influence of so-called positive selection on genes or gene regions known to be associated with the disorder than a comparable control set of non-associated genes, functioning in similar neuronal processes. This is consistent with the theory that positive selection may play a role in the persistence of schizophrenia at a frequency of one per cent in human populations around the world, despite its strong effects on…

Scientists are researching new ways of harnessing the sun’s rays which could eventually make it cheaper for people to use solar energy to power their homes. The experts at Durham University are developing light-absorbing materials for use in the production of thin-layer solar photovoltaic (PV) cells which are used to convert light energy into electricity. The four-year project involves experiments on a range of different materials that would be less expensive and more sustainable to use in the manufacturing of solar panels. Thicker silicon-based cells and compounds containing indium, a rare…

Mr. Hank Campbell, founder of Scientific Blogging, requested that I respond to a recent posting by Seth Roberts, a professor of psychology at UC Berkeley. Roberts attacks me as part of his continuing defense of another psychology professor, Michael Bailey of Northwestern University. In my judgment, Bailey’s work is bigoted and fraudulent. Roberts quotes from an op-ed I wrote in 2003 for the Stanford student newspaper describing a talk Bailey presented to the Stanford psychology department. The talk included film clips, animated cartoons, pictures and voice recordings to train people’s “gaydar…

Single-walled carbon nanotubes (SWCNTs) can kill bacteria like the common pathogen E. coli by severely damaging their cell walls, according to a recent report from Yale researchers in the American Chemical Society (ACS) journal Langmuir. “We began the study out of concerns for the possible toxicity of nanotubes in aquatic environments and their presence in the food chain,” said Menachem Elimelech, professor and chair of chemical and environmental engineering at Yale and senior author on the paper. “While nanotubes have great promise for medical and commercial applications there is little…

In studying how neurotransmitters travel between cells -- by analysis of events in the dimensions of nanometers -- Cornell researchers have discovered that an electrical current thought to be present during that process does not, in fact, exist. These results were reported July 22 in the online edition of the journal Nature Cell Biology by Cornell researchers Liang-Wei Gong and Manfred Lindau, applied and engineering physics, as well as their colleague Guillermo Alvarez de Toledo at the University of Seville, Spain. Lindau explained that neurotransmitters and hormones are stored in neurons…