Wilke, Robin Niklas

[["dc.bibliographiccitation.firstpage","464"],["dc.bibliographiccitation.journal","Journal of Applied Crystallography"],["dc.bibliographiccitation.lastpage","476"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Hoppert, Michael"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:44:29Z"],["dc.date.available","2017-09-07T11:44:29Z"],["dc.date.issued","2015"],["dc.description.abstract","Quantitative waveguide-based X-ray phase contrast imaging has been carried out on the level of single, unstained, unsliced and freeze-dried bacterial cells of Bacillus thuringiensis and Bacillus subtilis using hard X-rays of 7.9keV photon energy. The cells have been prepared in the metabolically dormant state of an endospore. The quantitative phase maps obtained by iterative phase retrieval using a modified hybrid input-output algorithm allow for mass and mass density determinations on the level of single individual endospores but include also large field of view investigations. Additionally, a direct reconstruction based on the contrast transfer function is investigated, and the two approaches are compared. Depending on the field of view and method, a resolution down to 65nm was achieved at a maximum applied dose of below 5 x 10(5)Gy. Masses in the range of about approximate to 110-190(20)fg for isolated endospores have been obtained."],["dc.identifier.doi","10.1107/S1600576715003593"],["dc.identifier.fs","615792"],["dc.identifier.gro","3141933"],["dc.identifier.isi","000352229100017"],["dc.identifier.pmid","25844079"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13672"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2691"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.intern","Merged from goescholar"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1600-5767"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.title","Quantitative X-ray phase contrast waveguide imaging of bacterial endospores"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","048103"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Physical Review Letters"],["dc.bibliographiccitation.volume","114"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Haber, J."],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:44:39Z"],["dc.date.available","2017-09-07T11:44:39Z"],["dc.date.issued","2015"],["dc.description.abstract","We demonstrate nanoscale x-ray holographic imaging using optimized illumination wave fronts emitted by x-ray waveguide channels. Mode filtering minimizes wave-front distortions and artifacts encountered in most hard x-ray focusing schemes, enabling quantitative reconstruction of the projected density, as evidenced by a test pattern imaged with a field of view of about 20 x 40 mu m and at 22 nm resolution. The dose efficiency and contrast sensitivity make the optical scheme compatible with samples of intrinsically low contrast, typical for hydrated soft matter. This is demonstrated by imaging bacteria in the hydrated and living state, with quantitative phase contrast revealing dense structures of the bacterial nucleoids associated with compactified DNA. In response to continued irradiation, characteristic changes in these dense structures are observed."],["dc.identifier.doi","10.1103/PhysRevLett.114.048103"],["dc.identifier.gro","3141970"],["dc.identifier.isi","000349871400012"],["dc.identifier.pmid","25679911"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11551"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/3101"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10 / Funder: German Research Foundation (DFG) [SFB 755/C1]"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1079-7114"],["dc.relation.issn","0031-9007"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.rights","CC BY 3.0"],["dc.subject.gro","x-ray imaging"],["dc.title","X-Ray Holographic Imaging of Hydrated Biological Cells in Solution"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","10"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Optical Nanoscopy"],["dc.bibliographiccitation.lastpage","7"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Priebe, Marius"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Krüger, Sven P"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Olendrowitz, Christian"],["dc.contributor.author","Sprung, Michael"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:54:07Z"],["dc.date.available","2017-09-07T11:54:07Z"],["dc.date.issued","2012"],["dc.description.abstract","We have imaged the three-dimensional density distribution of unstained and unsliced, freeze-dried cells of the gram-positive bacterium Deinococcus radiodurans by tomographic x-ray propagation microscopy, i.e. projection tomography with phase contrast formation by free space propagation. The work extends previous x-ray imaging of biological cells in the simple in-line holography geometry to full three-dimensional reconstruction, based on a fast iterative phase reconstruction algorithm which circumvents the usual twin-image problem. The sample is illuminated by the highly curved wave fronts emitted from a virtual quasi-point source with 10 nm cross section, realized by two crossed x-ray waveguides. The experimental scheme allows for a particularly dose efficient determination of the 3D density distribution in the cellular structure."],["dc.identifier.doi","10.1186/2192-2853-1-10"],["dc.identifier.fs","593648"],["dc.identifier.gro","3145116"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9581"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2817"],["dc.language.iso","en"],["dc.notes","Funding by the DFG collaborative research center SFB 755\r\nNanoscale Photonic Imaging and the German Ministry of Education and\r\nResearch (Grant No. 05K10MGA) is gratefully acknowledged."],["dc.notes.intern","Crossref Import"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.issn","2192-2853"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.title","Low-dose three-dimensional hard x-ray imaging of bacterial cells"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","867"],["dc.bibliographiccitation.journal","Journal of Synchrotron Radiation"],["dc.bibliographiccitation.lastpage","878"],["dc.bibliographiccitation.volume","22"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Osterhoff, Markus"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Priebe, Marius"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Sprung, Michael"],["dc.date.accessioned","2017-09-07T11:43:44Z"],["dc.date.available","2017-09-07T11:43:44Z"],["dc.date.issued","2015"],["dc.description.abstract","A compound optical system for coherent focusing and imaging at the nanoscale is reported, realised by high-gain fixed-curvature elliptical mirrors in combination with X-ray waveguide optics or different cleaning apertures. The key optical concepts are illustrated, as implemented at the Gottingen Instrument for Nano-Imaging with X-rays (GINIX), installed at the P10 coherence beamline of the PETRA III storage ring at DESY, Hamburg, and examples for typical applications in biological imaging are given. Characteristic beam configurations with the recently achieved values are also described, meeting the different requirements of the applications, such as spot size, coherence or bandwidth. The emphasis of this work is on the different beam shaping, filtering and characterization methods."],["dc.identifier.doi","10.1107/S1600577515007742"],["dc.identifier.gro","3141875"],["dc.identifier.isi","000357407900001"],["dc.identifier.pmid","26134789"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2045"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation","SFB 755: Nanoscale Photonic Imaging"],["dc.relation.eissn","1600-5775"],["dc.relation.issn","0909-0495"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","x-ray scattering"],["dc.title","Compound focusing mirror and X-ray waveguide optics for coherent imaging and nano-diffraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","19232"],["dc.bibliographiccitation.issue","17"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.lastpage","19254"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Priebe, Marius"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Diaz, Ana"],["dc.contributor.author","Karvinen, P."],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:48:27Z"],["dc.date.available","2017-09-07T11:48:27Z"],["dc.date.issued","2012"],["dc.description.abstract","Ptychographic coherent X-ray diffractive imaging (PCDI) has been combined with nano-focus X-ray diffraction to study the structure and density distribution of unstained and unsliced bacterial cells, using a hard X-ray beam of 6.2keV photon energy, focused to about 90nm by a Fresnel zone plate lens. While PCDI provides images of the bacteria with quantitative contrast in real space with a resolution well below the beam size at the sample, spatially resolved small angle X-ray scattering using the same Fresnel zone plate (cellular nano-diffraction) provides structural information at highest resolution in reciprocal space up to 2nm(-1). We show how the real and reciprocal space approach can be used synergistically on the same sample and with the same setup. In addition, we present 3D hard X-ray imaging of unstained bacterial cells by a combination of ptychography and tomography. (C) 2012 Optical Society of America"],["dc.identifier.doi","10.1364/OE.20.019232"],["dc.identifier.fs","589591"],["dc.identifier.gro","3142482"],["dc.identifier.isi","000307873600075"],["dc.identifier.pmid","23038565"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9566"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8773"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10 / Funder: Deutsche Forschungsgemeinschaft [SFB 755]"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1094-4087"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","x-ray scattering"],["dc.title","Hard X-ray imaging of bacterial cells: nano-diffraction and ptychographic reconstruction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","490"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Synchrotron Radiation"],["dc.bibliographiccitation.lastpage","497"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Wilke, Robin N."],["dc.contributor.author","Osterhoff, Markus"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2020-11-05T15:05:25Z"],["dc.date.available","2020-11-05T15:05:25Z"],["dc.date.issued","2013"],["dc.description.abstract","In the past decade Kirkpatrick-Baez (KB) mirrors have been established as powerful focusing systems in hard X-ray microscopy applications. Here a ptychographic characterization of the KB focus in the dedicated nano-imaging setup GINIX (Gottingen Instrument for Nano-Imaging with X-rays) at the P10 coherence beamline of the PETRA III synchrotron at HASLYLAB/DESY, Germany, is reported. More specifically, it is shown how aberrations in the KB beam, caused by imperfections in the height profile of the focusing mirrors, can be eliminated using a pinhole as a spatial filter near the focal plane. A combination of different pinhole sizes and illumination conditions of the KB setup makes the prepared optical setup well suited not only for high-resolution ptychographic coherent X-ray diffractive imaging but also for moderate-resolution/large-field-of-view propagation imaging in the divergent KB beam."],["dc.identifier.doi","10.1107/S0909049513005372"],["dc.identifier.gro","3142357"],["dc.identifier.isi","000317604800013"],["dc.identifier.pmid","23592629"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/68466"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-352.6"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0909-0495"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray optics"],["dc.subject.gro","x-ray imaging"],["dc.title","Versatility of a hard X-ray Kirkpatrick–Baez focus characterized by ptychography"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]