This thesis aims to demonstrate how the achromatic nature and design flexibility of liquid-crystal optics can be used to improve high-contrast imaging instruments to facilitate detailed exoplanet characterization.

Because thin systems can deform along the thickness with relative ease, the interplay between surface mechanics and geometry plays a fundamental role in sculpting their three-dimensional shape.

PhD defence

Source: Journal of Investigative Dermatology, Volume 135, pp. S59-S59 (2015)

LCD screens use liquid crystals which have a high degree of order, even though they form a fluid. A new theory maps out the interplay between order, temperature and symmetry. Publication in Physical Review X.

The outermost layer of the skin, the stratum corneum (SC), is responsible for the skin barrier function, protecting the body from pathogens, chemicals and other unwanted substances from the external environment. The SC lipid matrix provides the only continuous pathway through the SC and is considered…

The focus throughout this thesis will be on gathering fundamental studies of the detailed structure and composition of the electrode/electrolyte interface effect on the rate and mechanism of key electrocatalytic reactions.

How can photorealistic 3D scenes help predict whether interventions in urban public spaces will foster citizens' sense of security?

Promotor: J. A. Bouwstra

The stratum corneum is the outermost skin layer and consists of dead cells embedded in a lipid matrix.

BACKGROUND: Explant human skin equivalents (Ex-HSEs) can be generated by placing a 4mm skin biopsy onto a dermal equivalent. The keratinocytes migrate from the biopsy onto the dermal equivalent, differentiate and form the epidermis of 1(st) generation Ex-HSEs. This is especially suitable for the expansion…

Source: British Journal of Dermatology, Volume 170, Number 6, pp. E18-E19 (2014) ISBN:0007-0963

In the studies described in this study, we introduce a novel ex vivo human skin barrier repair model. To develop this, we removed the upper layer of the skin, the stratum corneum (SC) by a reproducible cyanoacrylate stripping technique.

In most applications, electrocatalysts exhibit a large surface area to volume ratio, for example using nanoparticles.

It has been a long-standing mystery how complex biological structures emerge from such seemingly uncoordinated building blocks as cells and tissues, in the presence of only minimal environmental guidance.

Promotor: M.T.M. Koper, Co-Promotor: L.B.F. Juurlink

The stratum corneum (SC) plays a fundamental role in the barrier function of the skin. The SC consists of corneocytes embedded in a lipid matrix.

Promotor: J. Zaanen

People with relatively high levels of lipids in their blood are less likely to develop allergic conditions such as eczema and asthma. These lipids cause genes that play a key role in allergic reactions to be less active. Researchers from the Leiden University Medical Center (LUMC) have published an…

The research described in this thesis shows that hypercholesterolemia, a well-established risk factor for atherosclerosis, can impact skin lipid pool and barrier function already at young age. In the field of atherosclerosis, we showed that the small peptide Lyp-1 can be used as a targeting molecule…

Nanodiscs are small, disc-shaped structures designed to mimic biological cell membranes, composed of a lipid bilayer stabilized by scaffold proteins. Membrane proteins play crucial roles in essential processes such as nutrient and waste transport, molecular recognition, and cell signalling, making them…

The adsorption of D2 and CO2 on catalyst surfaces is studied using a molecular beam in ultra-high vacuum.

This thesis introduces the concept of

Tuberculosis is a major global health problem caused by the Mycobacterium tuberculosis complex, claiming more than a million lives annually.

Promotor: Prof.dr. M.L. van Hecke, Co-Promotor: Prof. dr. V. Vitelli

The research presented in this thesis makes use of small molecules (as H2 , D2 and O2 ) on well-defined single crystal surfaces (flat Pt(111), flat Cu(211) and curved Pt(111)) to elucidate the role of surface structure and degrees of freedom in the reactant in specific surface reactions.

Promotor: A. Kros, Co-promotor: R.R.C.L. Olsthoorn

Cholesterol influences many pathways, including serving as precursor for adrenal steroidogenesis. Imbalance of cholesterol levels has been implicated in several diseases including cardiovascular diseases and its underlying pathology, atherosclerosis.

Promotor: Prof.dr. T.J. Aartsma, Co-promotor: R.N. Frese

Promotor: M.T.M. Koper, Co-promotor: J.B.F. Juurlink

The overarching goal of this thesis is to set the foundations, but also make the first essential steps towards establishing a comprehensive, mesoscopic, hydrodynamic theory of epithelial tissues. The stage is set by an exhaustive study of topological defects in passive p-atic liquid crystals, singularities…

Heterogeneous catalysis is essential to many industrial applications. These catalysts are often comprised of supported nanoparticles, which contain various different surface sites.

Promotor: Christoph U. Keller, Co-promotores: Matthew A. Kenworthy, Frans Snik

Inspired by natural photosynthesis, perovskite-based photoelectrochemical (PEC) systems are being developed for artificial photosynthesis, aiming to enhance solar-to-hydrogen conversion for green energy.

In surface science there is great effort to move from studying simple, flat model surfaces in vacuum to investigating more complex model catalysts in gas environments (in situ). This thesis gives three examples of such studies using microscopy and spectroscopy.

This thesis explores different avenues to develop insurmountable antagonists for CC Chemokine Receptors, such as CCR1, CCR2 and CCR5.

The first full-colour images of the cosmos from ESA's space telescope Euclid were presented today. Never before has a telescope been able to take such crystal-clear astronomical images of such a large part of the sky and so far into the deep universe. The five images illustrate Euclid's full potential;…

For the first time researchers have succeeded in placing a layer of graphene on top of a stable fatty lipid monolayer. Surrounded by a protective shell of lipids, graphene could enter the body and function as a versatile sensor. The results are the first step towards such a shell, and have been published…

Heart failure is a major health care problem with high mortality.

The PID-directed shift in PIN polarity has been broadly accepted as one of the essential mechanisms for the regulation of auxin transport polarity.

Promotor: A. Kros

Focus in skin research

Current research at the Skin Barrier and Vaccination group.

An important feature of atopic eczema (AE) is a decreased skin barrier function. The stratum corneum (SC) lipids - comprised of ceramides (CERs), free fatty acids (FFAs) and cholesterol - fulfill a predominant role in the skin barrier function.