Position at Amsterdam UMC
Miracles still happen. After I got a job at RIVM (project CESES) at the age of 61, in June 2023, at that time 72, I obtained an appointment for a year at Amsterdam University Medical Centers. Just as with my long-term (2007-2020) parttime appointment in Groningen to teach general dermatology to junior interns, this is an unpaid appointment. My function is to guide doctoral students in medicine in the scientific project they have to carry out during the doctoral phase, I am their 'daily supervisor'. I have supervised two students, and for year now, I have had a PhD student under my care.
How did I end up here? This is what happened. Oh yes, before I forget: I can do all my work from home with mail correspondence, by telephone and with monthly Zoom sessions, which was also a sine qua non for me. I would have been prepared to go to Amsterdam once if necessary for formalities, but a regular trip to the metropolis was out of the question for this hermit with autistic traits.
Back to how things went. Early 2023, I decided to stop publishing. But of course it soon started to itch, so it wasn't long before I started writing again, a large review article about 2-hydroxyethyl methacrylate (HEMA), the most important allergen in modern nail cosmetics (acrylic nails, gel nails, gel nailpolish). Well, I was looking forward again to writing and wanted to try to remain active in this field at least until early 2026, because then, if alive and well, I will be able to look back on a career of half a century, 50 years! But for this to be possible, I had to have access to scientific literature. When I was still teaching in Groningen, I had access to the library there via a proxy account, I could log in at home. My appointment ended in 2021 (I wasn't 'fired', mind you, but I myself have not submitted the request to extend the appointment), but I was able to arrange that I can continue to log in until 31-12-2023 . Anyway, I wanted to continue a bit longer than end of 2023, so I had to look for an alternative.
Fortunately, the (possible) problem was quickly resolved. I had already raised this issue previously with my friend Thomas Rustemeyer, who is professor of Dermato-Allergology and Occupational Dermatology at the Amsterdam UMC. At that time he suggested that he might be able to arrange a 'guest account' for me, so that I could access the library of the University of Amsterdam. So when I started working on the HEMA article, I asked him if he would like to be a co-author, as he is an expert in the field of acrylics, and he answered positively.

Very little is known about how often HEMA is used in nail cosmetics and I had a few ideas how we could find out. However, it would be a lot of work, so I asked Thomas if we could may be have a student do this study (I knew he regularly has students over for research projects). He thought that was a great idea, he asked me if I wanted to be the daily supervisor, of course I agreed and then the circle was complete and De Groot had a job at the Amsterdam UMC and a doctoral student under his care. I really like that I can now pass on my experience and knowledge not only through books and articles, but also directly to soon-to-be doctors!
Prof. dr. Thomas Rustemeyer
It is now September 2025 and my contract has been renewed twice already. Hopefully I can stay until Emma, our PhD candidate whom I supervise, has completed all the research and can receive her degree. May be I can - if alive and well - be her copromotor in 2 or 3 years. A fantastic prospect that I hope will come through.