Mexican passport, In transit to/from BKK... Do I need a VISA?

1. I am Mexico citizen traveling to From Los Angeles (LAX) to Bangkok (BKK) via Nanjin (NKG), layover in NKG of 5 hours only, I have a onward ticket, Do I need a VISA?
2. After 2 weeks, I will travel BKK to LAX via Shanghai (PVG), layover in PVG of 14 hours only, I have a onward ticket, Do I need a VISA?

Thanks,