SYDNEY, June 20 (Xinhua) -- Heading a soccer ball can cause subtle changes in the brain, even when no immediate symptoms or cognitive impairment are detected, new research has revealed.

LOS ANGELES, June 16 (Xinhua) -- Three people, including an 8-month-old infant, were killed and two others were injured in a shooting Sunday night at a carnival in western U.S. state of Utah, police ...

蛋白质修饰：LA-PEG-NHS 可与蛋白质表面的氨基反应，将 PEG 链段引入蛋白质，改善其溶解性、稳定性和生物活性，减少免疫原性，延长体内半衰期。例如，修饰抗体可提高其治疗效果。 多肽修饰：多肽通常稳定性低、半衰期短，LA-PEG-NHS 修饰可增加其亲水性和稳定 ...