As an advanced conformal therapy, Intensity-modulated radiotherapy (IMRT) can increase the gain ratio of radiotherapy and improve the local control of the tumor. This paper applies genetic algorithm to optimization of IMRT inverse planning. The algorithm model and simulation result are introduced.

To observe the therapeutic effect of Nitazoxanide(NTZ) on dogs infected with Giardia canis trophozoites.Eight dogs were infected with Giardia canis trophozoites and divided into four groups rondomly,G1:2 dogs treated with Nitazoxanide at a single dose of 1 mg/kg body weight;G2:2 dogs treated with NTZ at a single dose of 2 mg/kg;G3:2 dogs treated with NTZ at a single dose of 41 mg/kg;G4:2 dogs treated without drugs as control.All groups were examined for Giardia canis cysts by Zinc Sulfate Flotation.Each group was subjected to collect stool per day and counted cysts.The results of G2 and G3 were negative after 1th day.G1 were negative after 4th days.The results indicated that NTZ at a dose of 2 mg/kg and 4 mg/kg in dogs had a faourable effect on the dogs infected with Giardia canis.