text_1: 尽管 已知 高水平 的 脱氧 鞘 脂 具有 细胞 毒性 10 , 13 , 28 , 37 , 但 毒性 机制 尚 不 完全 清楚 .
  
text_2: although elevated levels of deoxysphingolipids are known to be cytotoxic , 10,13,28,37 the mechanism of their toxicity is not fully understood .
  