A US company has tested a brain implant in a Chinese patient in Shanghai, a rare sign of cooperation as the two countries compete to develop the most advanced neurotechnology.The Cambridge company, Axoft, also said on Wednesday it raised $55 million. It’s tested its device temporarily in 11 patients, including the one in Shanghai, chief executive officer Paul Le Floch said. The company plans to study its device in more patients in China this year and is planning multiple clinical trials in the country, he said.It’s the first time a US brain implant company has disclosed that it’s tested a…