Graphene is the only form of carbon (or solid material) in which every atom is available for chemical reaction from two sides (due to the 2D structure). Atoms at the edges of a graphene sheet have special chemical reactivity. Graphene has the highest ratio of edge atoms of any allotrope. Defects within a sheet increase its chemical reactivity.
Proton therapy or proton beam therapy is a medical procedure, a type of particle therapy that uses a beam of protons to irradiate diseased tissue, most often in the treatment of cancer.roton therapy's chief advantage over other types of external beam radiotherapy is that as a charged particle the dose is deposited over a narrow range and there is minimal exit dose.
Proton-beam therapy is a controversial alternative to conventional radiotherapy for prostate cancer patients; opponents say that evidence supporting its use just isn't there. However, a new study shows extremely high efficacy in 5-year outcomes for patients in all risk categories treated with proton-beam therapy.n comparison, acquisition costs for IMRT systems range from $1.8 million to $5.4 million, according to a 2009 report by the Institute for Clinical and Economic Review (ICER) on management options for low-risk prostate cancer.