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Your search keyword '"van Esch, Jan H."' showing total 442 results
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442 results on '"van Esch, Jan H."'

3. Influence of chemical structure on the stability and the conductance of porphyrin single-molecule junctions

Author

Perrin, Mickael L., Prins, Ferry, Martin, Christian A., Shaikh, Ahson J., Eelkema, Rienk, van Esch, Jan H., Briza, Tomas, Kaplanek, Robert, Kral, Vladimir, van Ruitenbeek, Jan M., van der Zant, Herre S. J., and Dulić, Diana

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Porphyrin molecules can form stable single molecule junctions without anchoring groups. Adding thiol end groups and pyridine axial groups yields more stable junctions with an increased spread in low-bias conductance. This is a result of different bridging geometries during breaking, the stability of which is demonstrated in time-dependent conductance measurements. This is in strong contrast with rod like molecules which show one preferential binding geometry., Comment: 8 pages, 4 figures

Published
2011

4. Charge Transport in a Zn-Porphyrin single molecule junction

Author

Perrin, Mickael L., Martin, Christian A., Prins, Ferry, Shaikh, Ahson J., Eelkema, Rienk, van Esch, Jan H., van Ruitenbeek, Jan M., van der Zant, Herre S. J., and Dulić, Diana

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We have investigated charge transport in ZnTPPdT-Pyr molecular junctions using the lithographic MCBJ technique at room temperature and cryogenic temperature (6K). We combined low-bias statistical measurements with spectroscopy of the molecular levels using I(V) characteristics. This combination allows us to characterize the transport in a molecular junction in detail. This complex molecule can form different junction configurations, which is observed in trace histograms and in current-voltage (I(V)) measurements. Both methods show that multiple stable single-molecule junction configurations can be obtained by modulating the inter-electrode distance. In addition we demonstrate that different ZnTPPdT-Pyr junction configurations can lead to completely different spectroscopic features with the same conductance values. We show that statistical low-bias conductance measurements should be interpreted with care, and that the combination with I(V) spectroscopy represents an essential tool for a more detailed characterization of the charge transport in a single molecule., Comment: 10 pages, 3 figures

Published
2011

13. An Implantable Artificial Atherosclerotic Plaque as a Novel Approach for Drug Transport Studies on Drug-Eluting Stents

Author

Razzi, Francesca, Lovrak, Matija, Gruzdyte, Dovile, Den Hartog, Yvette, Duncker, Dirk J., van Esch, Jan H., van Steijn, Volkert, van Beusekom, Heleen M.M., Razzi, Francesca, Lovrak, Matija, Gruzdyte, Dovile, Den Hartog, Yvette, Duncker, Dirk J., van Esch, Jan H., van Steijn, Volkert, and van Beusekom, Heleen M.M.

Abstract

Atherosclerotic arteries are commonly treated using drug-eluting stents (DES). However, it remains unclear whether and how the properties of atherosclerotic plaque affect drug transport in the arterial wall. A limitation of the currently used atherosclerotic animal models to study arterial drug distribution is the unpredictability of plaque size, composition, and location. In the present study, the aim is to create an artificial atherosclerotic plaque—of reproducible and controllable complexity and implantable at specific locations—to enable systematic studies on transport phenomena of drugs in stented atherosclerosis-mimicking arteries. For this purpose, mixtures of relevant lipids at concentrations mimicking atherosclerotic plaque are incorporated in gelatin/alginate hydrogels. Lipid-free (control) and lipid-rich hydrogels (artificial plaque) are created, mounted on DES and successfully implanted in porcine coronary arteries ex-vivo. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) is used to measure local drug distribution in the arterial wall behind the prepared hydrogels, showing that the lipid-rich hydrogel significantly hampers drug transport as compared to the lipid-free hydrogel. This observation confirms the importance of studying drug transport phenomena in the presence of lipids and of having an experimental model in which lipids and other plaque constituents can be precisely controlled and systematically studied.

Published
2022

20. Biocatalytic induction of supramolecular order

Author

Hirst, Andrew R., Roy, Sangita, Arora, Meenakshi, Das, Apurba K., Hodson, Nigel, Murray, Paul, Marshall, Stephen, Javid, Nadeem, Sefcik, Jan, Boekhoven, Job, van Esch, Jan H., Santabarbara, Stefano, Hunt, Neil T., and Ulijn, Rein V.

Published
2010
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23. Reversible optical transcription of supramolecular chirality into molecular chirality

Author

de Jong, Jaap J.D., Lucas, Linda N., Kellogg, Richard M., van Esch, Jan H., and Feringa, Ben L.

Subjects
Chirality -- Research, Molecular electronics -- Properties -- Research, Science and technology, Research, Properties
Abstract

In nature, key molecular processes such as communication, replication, and enzyme catalysis all rely on a delicate balance between molecular and supramolecular chirality. Here we report the design, synthesis, and operation of a reversible, photoresponsive, self-assembling molecular system in which molecular and supramolecular chirality communicate. It shows exceptional stereoselectivity upon aggregation of the molecules during gel formation with the solvent. This chirality is locked by photochemical switching, a process that is subsequently used to induce an inverted chiral supramolecular assembly as revealed by circular dichroism spectroscopy. The optical switching between different chiral aggregated states and the interplay of molecular and supramolecular chirality offer attractive new prospects for the development of molecular memory systems and smart functional materials., The challenge of controlling chirality at different hierarchical levels (1-3) is particularly evident in the context of molecular self-assembly, protein folding, and the design of memory systems, sensors, and nanostructured [...]

Published
2004

28. Gels

Author

van Esch, Jan H., primary and Feringa, Ben L., additional

Published
2004
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29. Silk Fluorescence Collimator for Ultrasensitive Humidity Sensing and Light-Harvesting in Semitransparent Dye-Sensitized Solar Cells

Author

Hu, Fan, Liu, Wenzhe, Li, Weifeng, Xu, Zijie, Diao, Ying Ying, Lin, Nai Bo, Guo, Wenxi, Shi, Lei, van Esch, Jan H., Liu, Xiang Yang, Hu, Fan, Liu, Wenzhe, Li, Weifeng, Xu, Zijie, Diao, Ying Ying, Lin, Nai Bo, Guo, Wenxi, Shi, Lei, van Esch, Jan H., and Liu, Xiang Yang

Abstract

This work examines the self-collimation effect of silk materials on fluorescence emission/detection. A macroscopic regulation strategy, coupled with meso-reconstruction and meso-functionalization, is adopted to amplify the fluorescence emission of organic fluorescent dyes (i.e., Rhodamine 6G (R6G)) using silk photonic crystal (PC) films. The fluorescence emission can be linearly enhanced or inhibited by a PC as a result of the photonic bandgap coupling with the excitation light and/or emission light. Depending on the design of the silk fluorescence collimator, the emission can reach 49.37 times higher than the control. The silk fluorescence collimator can be applied to achieve significant benefits: for instance, as a humidity sensor, it provides good reproducibility and a sensitivity of 28.50 a.u./% relative humidity, which is 80.78 times higher than the sensitivity of the control, and as a novel curtain, it raises the energy conversion efficiency of the semitransparent dye-sensitized solar cells (DSSCs) by 16%.

Published
2019

48. Fuel-Mediated Transient Clustering of Colloidal Building Blocks

Author

Van Ravensteijn, Bas G.P., Hendriksen, Wouter E., Eelkema, Rienk, Van Esch, Jan H., Kegel, Willem K., Van Ravensteijn, Bas G.P., Hendriksen, Wouter E., Eelkema, Rienk, Van Esch, Jan H., and Kegel, Willem K.

Abstract

Fuel-driven assembly operates under the continuous influx of energy and results in superstructures that exist out of equilibrium. Such dissipative processes provide a route toward structures and transient behavior unreachable by conventional equilibrium self-assembly. Although perfected in biological systems like microtubules, this class of assembly is only sparsely used in synthetic or colloidal analogues. Here, we present a novel colloidal system that shows transient clustering driven by a chemical fuel. Addition of fuel causes an increase in hydrophobicity of the building blocks by actively removing surface charges, thereby driving their aggregation. Depletion of fuel causes reappearance of the charged moieties and leads to disassembly of the formed clusters. This reassures that the system returns to its initial, equilibrium state. By taking advantage of the cyclic nature of our system, we show that clustering can be induced several times by simple injection of new fuel. The fuel-mediated assembly of colloidal building blocks presented here opens new avenues to the complex landscape of nonequilibrium colloidal structures, guided by biological design principles.

Published
2017

49. Fuel-Mediated Transient Clustering of Colloidal Building Blocks

Author

Sub Physical and Colloid Chemistry, Physical and Colloid Chemistry, Van Ravensteijn, Bas G.P., Hendriksen, Wouter E., Eelkema, Rienk, Van Esch, Jan H., Kegel, Willem K., Sub Physical and Colloid Chemistry, Physical and Colloid Chemistry, Van Ravensteijn, Bas G.P., Hendriksen, Wouter E., Eelkema, Rienk, Van Esch, Jan H., and Kegel, Willem K.

Published
2017

50. Quantitatively interpreting thermal behavior of self-associating systems

Author

Koper, Ger J. M., Minkenberg, Christophe B., Upton, Ian S., van Esch, Jan H., and Sudhlter, Ernst J. R.

Subjects
Calorimetry -- Usage, Surface active agents -- Chemical properties, Surface active agents -- Thermal properties, Surface active agents -- Structure, Thermodynamics -- Analysis, Chemicals, plastics and rubber industries
Published
2009

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