PURPOSE This study aimed to compare the dosimetric profiles of electron beams (EB) and X-ray beams (XB) for boosting irradiation in breast cancer patients who underwent breast-conserving surgery and postoperative radiotherapy. METHODS For 131 breast cancer patients who underwent breast-conserving surgery, we compared plans for EB and XB boost irradiation after whole-breast irradiation. The or...

permafrost). Of the remainder, the vast majority is groundwater, so that just 0.4 per cent of the world's total freshwater is available at the surface as lakes, soil moisture, air humidity, marshes, wetlands, rivers and biomass. And water is proving an increasingly critical component in agricultural activities. Earlier this month, the Chinese government declared an emergency for the first time ...

The efficient development of effective vaccines and therapeutics is perhaps the most challenging of the myriad promises of post-genomic biology. Fortunately, as the list of sequenced bacterial pathogens grows, so does the opportunity to use whole genome sequence as a potentially powerful tool in vaccine development. According to Rino Rappuoli, vice president of vaccine research at Chiron, genom...

could have worked. " The scientists hypothesise that interbreeding between our ancestral humans and early chimps created a third, infertile 'hybrid' species, the human equivalent of a mule, the infertile offspring of a horse and donkey. Though incapable of breeding among its own, the hybrid is believed to have survived by mating with its parent human or chimp species, before the two separated t...

Over-wintering monarch butterflies in the forests of central Mexico may be looking forward to more secure rest following an announcement by the Mexican government of a budget boost of $4.6 million per year to improve the conditions for the migrant butterflies and for the many often prominent human visitors, and to tackle illegal logging. Conservation officials said that the additional funds for...