As you walk through life, you meet many people. In extremely rare cases, such an encounter changes your life. Meeting with Jan Kramers certainly changed my - an encounter that was followed by about 20 years of communication and collaboration.

I thank my destiny for connecting me with Jan Kramers, for the happiness of interacting and working with such a great person and scientist. In so doing, I am also expressing the gratitude of many colleagues and authors of articles in this issue who have been treated with respect by Jan and have benefitted from his patient teaching and his hands-on training, from the splendid creative atmosphere inspired by Jan.

当您走过人生时，您会遇到很多人。在极少数情况下，这种相遇会改变您的生活。与Jan Kramers的会晤无疑改变了我-经历了大约20年的沟通与协作。

感谢我与Jan Kramers的联系，以及与如此出色的人和科学家互动和合作的幸福，我的命运。通过这样做，我也要表达本期文章的许多同事和作者的感激之情，这些同事和文章的作者受到Jan的尊重，并受益于他耐心的教学和动手训练，以及Jan启发的灿烂创造力。