Large areas of space are filled by molecular clouds that consist of gas and dust grains that are the remnants of dead stars. When these clouds start collapsing, the decreasing temperature and increasing density cause gas particles to start accreting onto dust grain surfaces.

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disc surrounding a young star. The discovery reaffirms that the conditions that spawned the Earth and Sun are not unique in the Universe. The results are published…

Stars like the sun are born in large molecular clouds existing from gas and dust. During the formation process, the chemical composition of the material can be altered drastically by the changing physical conditions.

This thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores.

Promotor: H.V.J. Linnartz

I will give a general introduction to the field of molecular electronics, its history, methods and challenges. I will also introduce the subject of my investigation and provide a brief outlook to the remainder of our thesis.

Bioactive Molecules is one of the four research themes of the Institute of Biology Leiden.

Single-Molecule Microscopy (SMM) techniques constitute a group of powerful imaging tools that enable researchers to study the dynamic behavior of individual molecules.

Promotor: E. F. van Dishoeck, Co-promotor: C. Walsh

Promotor: M. Ubbink, Co-promotor: G. Siegal

Lecture

Microbial Sciences' contribution to the Bioactive Molecules research theme is to discover new bioactive molecules and enzymes and unravel their mechanisms of action, regulatory networks, and the (bio)synthetic pathways required for their production.

Even a small quantum computer should be able to simulate exactly the properties and behaviour of new molecules. This would take chemistry to an entirely new level. Better solar panels, more powerful batteries, saving lots of energy in the chemical industry: the applications have the potential to transform…

Plant Sciences' contribution to the Bioactive Molecules research theme is to identify new plant bioactive molecules, and unravel their mechanisms of action in plant development or health, and the regulatory networks and (bio)synthetic pathways required for their production.

This thesis is a collection of experimental attempts to enhance photoluminescence of fluorescent molecules and quantum dots with single gold nanorods (GNRs) and relevant applications.

Animal Sciences’ contribution to the Bioactive Molecules research theme includes research on molecules from natural sources, such as plants, insects, and snake venom, with the aim to identify novel anti-cancer, anti-inflammatory, anti-microbial, and anti-diabetic agents.

Our DNA molecules are packaged by proteins in compact structures. The aim of this project is to understand how modern gene editing techniques nevertheless get access to their target in the DNA.

Schneider

Since the early 1990s, one can isolate the optical signal of a single molecule and single-molecule spectroscopy has quickly grown into an important research field.

Promotor: Prof.dr. H.V.J. Linnartz, Co-Promotores: S. Ioppolo, H.M. Cuppen

This thesis revolves around the electronic spectroscopy of molecules in the laboratory and the search for the carriers of the diffuse interstellar bands (DIBs).

While bioinformatics methods deal with the analysis of sequence information (be it proteins or DNA), the field of cheminformatics is concerned with the analysis of small-molecule datasets.

Promotor: Prof.dr. E. F. van Dishoeck, Co-promotor: A. N. Heays

Intrigued by the way cells autonomously regulate their fate, we strive to understand and visualize cellular processes as the basis of Cell Signaling.

PhD defence

The main focus of the thesis is the discovery and development of novel inhibitors of bacterial metallo-β-lactamases (MBLs).

For many system in statistical physics the microcanonical and canonical ensemble are equivalent in the thermodynamic limit, but not for all.

Promotor: M. Ubbink, Co-promotor: G. Siegal

MHC class I and MHC class II molecules present peptides to the immune system to drive proper T cell responses. Pharmacological modulation of T-cell responses can offer treatment options for a range of immune-related diseases.

Deficiency of glucocerebrosidase (GBA) underlies Gaucher disease, a common lysosomal storage disorder. Carriership for Gaucher disease has recently been identified as major risk for parkinsonism. Presently, no method exists to visualize active GBA molecules in situ. We here report the design, synthesis…

Promotores: Prof.dr. G.W. Canters, Prof.dr. T.J. Aartsma

This perspective addresses four challenges facing theorists whose aim is to make quantitatively accurate predictions for reactions of molecules on metal surfaces, and suggests ways of meeting these challenges, focusing on dissociative chemisorption reactions of H2, N2, and CH4.

Can we determine the 3D structure of a chemotaxis core complex using single-particle reconstructions via cryo-EM?

Can we develop new enzymes and cell factories to upgrade current enzyme cocktails towards complete degradation of biomass?

We study the physics of a broad range of biological and soft materials

Promotor: Prof.dr. T. Hankemeier, Co-Promotor: R.J. Vreeken

In this thesis, we show that we can use Shimura’s CM theory to explicitly compute the Hilbert class field of any primitive quartic CM field.

Promotor: Prof.dr. M.A.G.J. Orrit

How do you progress from an immense gas cloud somewhere in the universe to a star with planets? Research by Astronomy PhD student Martijn van Gelder sheds more light on the earliest phases of this process. He will receive his doctorate on November 24th.

Several techniques are explored for going beyond the born-oppenheimer static surface model for molecule-surface reactions.

In this thesis we investigated the ability of two-photon multifocal microscopy for single-molecule microscopy in live cells and organisms.

In human cells, a meter-long DNA is condensed inside a micrometer-sized cell nucleus. Simultaneously, the genetic code must remain accessible for its replication and transcription to functional proteins.

Protein–protein complexes are formed via transient states called encounter complexes that greatly influence the formation of the stereospecific complex.

Promotor: G.A. van der Marel, Co-promotor: D.C. Codée

This thesis seeks to combine two different research topics; Multi-Objective Optimization and Complex Network Analysis.

Promotor: M. Ubbink, Co-promotor: G. Siegal

What invertebrates are available to feed nestlings in an agricultural landscape of varied complexity?

This thesis examines the link between simple molecules and the underlying structure and chemistry within protoplanetary disks - the birthplaces of planets.

The goal of the project is the development of stream mining techniques for complex patterns such as graphs. We will try to extend the existing state-of-the-art techniques into two, orthogonal directions: on the one hand, the mining of more complex patterns in streams, such as sequential patterns and…

At the Old Observatory, we work with a small but knowledgeable team. This page contains the contact details of the various people in our team.