"If study is not part of today don't say you have a tomorrow....Take  advantage of today for time quickly passes"--two sayings of  the well-known Chinese Philosopher Zhu Wen Kung, which appeared in a  Peace Weekly article praising the work ethic of the man profiled in the  article, a doctor of  nuclear medicine. 
Retired  from his position  as professor at the  Catholic  University after 37 years, he has continued to work in  medicine for the last 16 years. He thanks God for the good health that  enables him to keep working, and is happy  to be able to help those who  need his care. Age is not a problem, he says, when it comes to his  research studies; when he's involved in study, it feels like he's  meeting his sweet heart, because of all the joy that it gives him.
He has been working in PET-CT (Positron  emission tomography-computed tomography). the field of nuclear  medicine, a branch of medical imaging, that uses small amounts of  radioactive material to diagnose or treat a variety of diseases or  abnormalities in the body.
"Humanity is a mystery," he says.  Are we able to make hair or fingernails? We  are God's masterpieces, made with delicacy and exquisiteness that only we humans can understand."
A recent study of his that culminated in attaching a gamma camera to the eye of a needle to search  for fractures appeared in his dissertation published last year in a medical journal. "When one continues to do  research these moments of discovery come. It may seem that the discovery  was by accident, but it was not."
He has published over 380 treatises, and of this number over 40 are  listed in the Science Citation Index. And since  retirement he continues to write, publishing two treatises  each year. But even a cart, he says, can go on moving for a 100 years if the chassis is  strong and the wheels are in good shape. What is  important is where is it  going and the  reason. 
His occupation, he makes clear, is his vocation to help people  according to God's wishes.  Since it is a vocation for the welfare of  others it is a life of  study, even into old age, which draws all of us to admire not only this  remarkable doctor but all those who keep mentally  active and  concerned for others. The Prophet Micah said  it beautifully: "You have been told, Oh man, what is good and what the  Lord requires of you: Only to do the right and to love goodness and to  walk humbly with your God" (Micah 6:8).