Het is de grootste structuur in het heelal: een duizelingwekkend web van materie dat sterrenstelsels zoals de Melkweg onderling verbindt. De Leidse Joop Schaye en Michael Maseda waren twee van de astronomen die hielp een piepklein stukje van dit 'kosmische spinnenweb' in beeld te brengen. In de Volkskrant…

This thesis presents the systematics, epidermal defense, and bioprospecting of wild orchids.

Promotor: F.J. van Lunteren, E. Jorin

In this thesis, the discovery and optimization is described of chemical tools to study the N-acylethanolamine (NAE) biosynthetic pathway.

To gain more insight into the evolutionary development of orchid flowers and fruits, the orchid species Erycina pusilla was studied. The evolutionary origin of the median petaloid sepal, the callus on the labellum, and the stelidia was studied.

In 1575 opende de Universiteit Leiden haar deuren. De eerste universiteit in Nederland. De Faculteit der Rechtsgeleerdheid was er vanaf het begin bij. Daarom vierden zij ook als faculteit dit jaar hun eigen 450-lustrum.

Een internationaal onderzoeksteam heeft voor het eerst het moment vastgesteld waarop zich planeten begonnen te vormen rond een andere ster dan onze zon. Met behulp van de ALMA-telescoop, waarin de Europese Zuidelijke Sterrenwacht (ESO) partner is, en de James Webb ruimtetelescoop (JWST), hebben ze het…

The formation and evolution of galaxies is fundamentally driven by the formation of new stars out of cold gas.

I have studied the hot, diffuse gas around and between galaxies. Specifically, I have used the EAGLE numerical simulations of galaxy formation to predict the properties of this gas, and I have used those properties to predict specific observables: soft X-ray absorption and emission lines.

Zeventien rotsen die in een baan rond de zon zweven dragen nu de naam van een Nederlander, zo bericht nu.nl. Zes van hen zijn Leidse sterrenkundigen.

Een sterrenstelsel kan groeien door gas uit zijn directe omgeving naar binnen te trekken. Maar astronomen weten nog niet precies hoe dit gebeurt. Sterrenkundige Joop Schaye gaat met een Europese onderzoekssubsidie van 1,5 miljoen euro op zoek naar antwoorden.

Leiden University College (LUC), een instituut van de Universiteit Leiden in Den Haag – de internationale stad van vrede, recht en veiligheid – biedt sinds 2010 de Engelstalige bacheloropleiding Liberal Arts and Sciences: Global Challenges. Geïnspireerd door het Amerikaanse university college-model…

Leiden University College (LUC), een instituut van de Universiteit Leiden in Den Haag – de internationale stad van vrede, recht en veiligheid – biedt sinds 2010 de Engelstalige bacheloropleiding Liberal Arts and Sciences: Global Challenges. Geïnspireerd door het Amerikaanse university college-model…

How were the Russians, under early modern conditions, able to incorporate this distant, undeveloped and, because frequent nomadic attacks, dangerous territory? And what role did the Kolyvan-Voskresensk plants play in this process?

Hybrid zones occur where two species meet and produce offspring (hybrids). Typically, hybrids show a considerable reduction in fitness. In this thesis two hybrid zones are treated.

Despite the fact that gold nanoparticles (GNPs) are one of the most studied nanoparticles, there is still a necessity for new approaches allowing for effective protective coating to enable wider use of GNPs in biomedical applications.

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

Promotor: E.F. Smets, Co-promotor: J. Geml

The research described in this thesis focused on identifying novel drug targets and synergistic combinations for triple-negative breast cancer (TNBC), a virulent subtype of breast cancer with a dismal prognosis and limited therapeutic options.

Diacylglycerol lipases (DAGLα and DAGLβ) are responsible for the biosynthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG) in the brain and peripheral tissues. Selective DAGLβ inhibitors have been proposed as a potential treatment for inflammatory diseases with reduced potential for central…

In the last decade, the redox interconversion between metal thiolate and disulfide compounds has been extensively investigated for copper, but not for other transition metal ions.

In this thesis, we aimed to better understand the underlying mechanisms involved in TNBC progression and metastasis formation and discover new targets to reduce breast cancer related deaths.

Promotor: Prof.dr. E.F. Smets, Co-Promotor: L.W. Chatrou

Neurodegenerative diseases pose a large medical and societal challenge. The etiology of these diseases is still poorly understood, which makes drug discovery for these diseases difficult.

This thesis advances our understanding of lipid uptake, a vital first step in lipid metabolism, by developing innovative click chemistry-based tools to study how immune cells internalize lipids.

Sorghum (Sorghum bicolor) is a major cereal crop that millions of subsistence farmers in Sub-Saharan Africa (SSA) rely on. However, the scourging impact of the root parasitic weed Striga (Striga hermonthica, a.k.a. “witch-weed”) has remained a major constraint hampering the productivity of sorghum in…

Cardiovascular diseases are a leading cause of death worldwide, and better models are urgently needed for disease progression studies and drug development.

Promotor: P.G.L. Klinkhamer, Co-Promotores: K. Vrieling, P.P.J. Mulder

Microbiome composition of the spermosphere and the rhizosphere of wild and modern bean accessions grown in an agricultural and a native soil from Colombia was characterized by metagenomics and cultivation-dependent approaches.

Filamentous Actinobacteria, such as Streptomyces, produce a plethora of chemically diverse bioactive metabolites that have found applications across medicine, agriculture and biotechnology.

Promotors: Prof.dr. T.H.W. Bäck, Prof.dr. B. Sendhoff (Technische Universität Darmstadt)

Promotor: Prof.dr. R. Verpoorte, Co-Promotores: N.R. Mustafa, A.E. Schulte

This thesis investigates reactive interfaces in surface science across three domains: heterogeneous catalysis, environmental nanoplastics, and two-dimensional materials.

Climate change is one of the largest challenges faced by humanity. To combat this research into alternatives to fossil fuels is ongoing. Dihydrogen is considered a good alternative fuel, since its burning only forms water.

Promotores: Prof.dr. H. van Veen & Prof.dr. W. de Boer (Wageningen University)

The spindle-assembly checkpoint (SAC) is a safety mechanism which secures accurate chromosome segregation during mitosis.

This PhD-thesis presents a study on micron-sized particles, so-called colloids. By controlling the chemical and physical properties of these particles, such as the interparticle interaction and the particles’ shape, colloids can act as building blocks that self-assembly into larger structures.

Advanced sensing techniques require graphene with high quality and well-controlled surface chemistry.

In this dissertation iron-based homogeneous catalysts were synthesized, characterized and investigated for water oxidation activity.

Promotor: J.G.E.M. Fraaije, Co-Promotor: A. Kros

The lipids in the uppermost layer of the skin, the stratum corneum (SC), play an important role in the skin barrier function. The three main SC lipid classes are ceramides (CER), cholesterol and free fatty acids.

Fungal food spoilage often starts with a contamination with spores. Experimental data strongly indicate the existence of subpopulations of spores with different levels of resistance to preservation methods.

Stars and planets form within cold, dense clouds of gas and dust drifting through interstellar space. Although dust makes up only a small fraction of this material, it plays a key role in shaping the chemical evolution of these environments.

The chemical and structural heterogeneity of toxoid vaccines makes their analysis challenging. However, detailed insights on a molecular level can be obtained by mass spectrometry.

A century ago, it was unclear whether the stars in the sky were clustered in groups, or widely spread in the universe.

The work described in this dissertation contributes to a better mechanistic understanding of nanoparticles in vivo. To achieve that goal, we used the zebrafish as a highly predictive pre-screening model of nanoparticles.

This thesis describes the design and synthesis of fragments of various cell wall carbohydrates of the Streptococcus species, including the branched Group B-specific antigen (GBC) of Group B Streptococcus, glycerol phosphate (GroP) modified group A carbohydrate (GAC), and the O-acetylated type 1 capsular…

As leading cause of death worldwide, cancer is responsible for nearly 10 million deaths in 2020 according to World Health Organization (WHO). Cisplatin and its derivatives are commonly used chemotherapy agents for current cancer treatment in the clinics.