Physicists exploring flexible carbon’s future
Can graphene — a newly discovered form of pure carbon that may one day replace the silicon in computers, televisions, mobile phones and other common electronic devices — be made to bend, twist and roll?
Physicists at UCSD and Boston University think so. In a paper published in the journal Physical Review B, the scientists say the affinity of graphene — a single layer of carbon atoms arranged in a honeycomb lattice — to stick to itself and form carbon “nanoscrolls” could be controlled electrostatically to form a myriad of new devices.
Among future applications envisioned: actuators whose operation resembles the blinking of one’s eyes, valves in lab-on-a-chip devices, and even a form of electronic paper. In the near term, scientists hope that graphene, which is an optically transparent conductor of electricity, could be used to replace current liquid crystal displays that employ thin metal-oxide films based on indium, a rare metal that is becoming increasingly expensive and likely to be in short supply within a decade. More information:
Chemists at The Scripps Research Institute have synthesized a new nano-scale scientific tool — a tiny molecular switch that turns itself on or off as it detects metallic ions in its immediate surroundings.
The molecule has a cuplike “head” at one end and a “tail” at the other. When no metals are present, the molecule’s tail is held within a cavity at its opposite end. The molecule signals the presence of metals by springing open and releasing its tail. Remove the metal, and the tail once again plugs the end of the molecule.
Researchers named the molecule “ouroborand,” calling to mind the mythical Ouroboros (“tail-eater” in Greek) — a lizardlike creature that swallows itself head-to-tail. The discovery is the cover article in the April 19 issue of the journal Angewandte Chemie. News release:
Stem cell mystery solved
The hope for stem cell research is that one day it will be possible to direct the growth of nerve, heart or lung cells in order to repair tissue damaged by disease or injury.
Progress toward this goal, however, has been hampered by the fragile nature of human embryonic stem cells grown in culture. Unless extraordinary, labor-intensive care is taken, the cells tend to die when split off from their cell colonies (a critical step in research).
Scientists at The Scripps Research Institute report the discovery of two novel synthetic small molecule drugs that can be added to human stem cell culture that prevents the death of these cells and the mechanisms by which the compounds promote stem cell survival. This provides scientists with useful new techniques to move the field forward and sheds light on a previously unknown aspect of stem cell biology.
The findings appear in the journal Proceedings of the National Academy of Sciences (PNAS). News release:
Lynne Friedmann is a science writer based in Solana Beach.