Bartels, Matthias

[["dc.bibliographiccitation.firstpage","561"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Structural Biology"],["dc.bibliographiccitation.lastpage","568"],["dc.bibliographiccitation.volume","192"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Cloetens, Peter"],["dc.contributor.author","Möbius, Wiebke"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:54:52Z"],["dc.date.available","2017-09-07T11:54:52Z"],["dc.date.issued","2015"],["dc.description.abstract","We have used X-ray phase contrast tomography to resolve the structure of uncut, entire myelinated optic, saphenous and sciatic mouse nerves. Intrinsic electron density contrast suffices to identify axonal structures. Specific myelin labeling by an osmium tetroxide stain enables distinction between axon and surrounding myelin sheath. Utilization of spherical wave illumination enables zooming capabilities which enable imaging of entire sciatic intemodes as well as identification of sub-structures such as nodes of Ranvier and Schmidt-Lanterman incisures. (C) 2015 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.jsb.2015.11.001"],["dc.identifier.gro","3141782"],["dc.identifier.isi","000365458400028"],["dc.identifier.pmid","26546551"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1013"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1095-8657"],["dc.relation.issn","1047-8477"],["dc.relation.orgunit","Institut für Röntgenphysik"],["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","Myelinated mouse nerves studied by X-ray phase contrast zoom tomography"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1114"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Clinical Investigation"],["dc.bibliographiccitation.lastpage","1129"],["dc.bibliographiccitation.volume","124"],["dc.contributor.author","Hernandez, Victor H."],["dc.contributor.author","Gehrt, Anna"],["dc.contributor.author","Reuter, Kirsten"],["dc.contributor.author","Jing, Zhizi"],["dc.contributor.author","Jeschke, Marcus"],["dc.contributor.author","Schulz, Alejandro Mendoza"],["dc.contributor.author","Hoch, Gerhard"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Vogt, Gerhard"],["dc.contributor.author","Garnham, Carolyn W."],["dc.contributor.author","Yawo, Hiromu"],["dc.contributor.author","Fukazawa, Yugo"],["dc.contributor.author","Augustine, George J."],["dc.contributor.author","Bamberg, Ernst"],["dc.contributor.author","Kügler, Sebastian"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Hoz, Livia de"],["dc.contributor.author","Strenzke, Nicola"],["dc.contributor.author","Moser, Tobias"],["dc.date.accessioned","2017-09-07T11:46:28Z"],["dc.date.available","2017-09-07T11:46:28Z"],["dc.date.issued","2014"],["dc.description.abstract","Auditory prostheses can partially restore speech comprehension when hearing fails. Sound coding with current prostheses is based on electrical stimulation of auditory neurons and has limited frequency resolution due to broad current spread within the cochlea. In contrast, optical stimulation can be spatially confined, which may improve frequency resolution. Here, we used animal models to characterize optogenetic stimulation, which is the optical stimulation of neurons genetically engineered to express the light-gated ion channel channelrhodopsin-2 (ChR2). Optogenetic stimulation of spiral ganglion neurons (SGNs) activated the auditory pathway, as demonstrated by recordings of single neuron and neuronal population responses. Furthermore, optogenetic stimulation of SGNs restored auditory activity in deaf mice. Approximation of the spatial spread of cochlear excitation by recording local field potentials (LFPs) in the inferior colliculus in response to suprathreshold optical, acoustic, and electrical stimuli indicated that optogenetic stimulation achieves better frequency resolution than monopolar electrical stimulation. Virus-mediated expression of a ChR2 variant with greater light sensitivity in SGNs reduced the amount of light required for responses and allowed neuronal spiking following stimulation up to 60 Hz. Our study demonstrates a strategy for optogenetic stimulation of the auditory pathway in rodents and lays the groundwork for future applications of cochlear optogenetics in auditory research and prosthetics."],["dc.identifier.doi","10.1172/JCI69050"],["dc.identifier.gro","3142178"],["dc.identifier.isi","000332347700030"],["dc.identifier.pmid","24509078"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5399"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1558-8238"],["dc.relation.issn","0021-9738"],["dc.relation.orgunit","Institut für Röntgenphysik"],["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","Optogenetic stimulation of the auditory pathway"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","033847"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Physical Review A"],["dc.bibliographiccitation.volume","89"],["dc.contributor.author","Ruhlandt, Aike"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:46:24Z"],["dc.date.available","2017-09-07T11:46:24Z"],["dc.date.issued","2014"],["dc.description.abstract","We present a solution to the phase problem in near-field x-ray (propagation) imaging. The three-dimensional complex-valued index of refraction is reconstructed from a set of projections recorded in the near-field (Fresnel) setting at a single detector distance. The solution is found by an iterative algorithm based only on the measured data and the three-dimensional tomographic (Helgason-Ludwig) consistency constraint without the need for further a priori knowledge or other restrictive assumptions."],["dc.identifier.doi","10.1103/PhysRevA.89.033847"],["dc.identifier.gro","3142164"],["dc.identifier.isi","000333410700008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5244"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.eissn","1094-1622"],["dc.relation.issn","1050-2947"],["dc.relation.orgunit","Institut für Röntgenphysik"],["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","Three-dimensional phase retrieval in propagation-based phase-contrast imaging"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","159901"],["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","Applied Physics Letters"],["dc.bibliographiccitation.volume","103"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Hernandez, Victor H."],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Moser, Tobias"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2018-11-07T09:18:43Z"],["dc.date.available","2018-11-07T09:18:43Z"],["dc.date.issued","2013"],["dc.identifier.doi","10.1063/1.4821922"],["dc.identifier.isi","000325779700099"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28467"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1077-3118"],["dc.relation.issn","0003-6951"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.title","Phase contrast tomography of the mouse cochlea at microfocus x-ray sources"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","16"],["dc.bibliographiccitation.journal","Physics in Medicine and Biology"],["dc.bibliographiccitation.volume","57"],["dc.contributor.author","Olendrowitz, Christian"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Beerlink, André"],["dc.contributor.author","Mokso, R."],["dc.contributor.author","Sprung, Michael"],["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","We have analyzed the model organism Caenorhabditis elegans with the help of phase-contrast x-ray tomography. This work combines techniques from x-ray imaging studies of single biological cells by in-line holography with three-dimensional reconstruction and furthermore extends these studies to the multicellular level. To preserve the sub-cellular ultrastructure of the nematodes, we used the near-native sample preparation of high-pressure freezing as commonly used in the field of electron microscopy. For the presented samples, a standard, non-magnifying parallel-beam setting, as well as a magnifying, divergent-beam setting using nanofocusing optics is evaluated based on their tomographic reconstruction potential. In this paper, we address difficulties in sample preparation and issues of image processing. By experimental refinement and through optimized reconstruction procedures, we were able to perform x-ray imaging studies on a living specimen."],["dc.identifier.doi","10.1088/0031-9155/57/16/5309"],["dc.identifier.gro","3142478"],["dc.identifier.isi","000307112600017"],["dc.identifier.pmid","22853964"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8729"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0031-9155"],["dc.relation.orgunit","Institut für Röntgenphysik"],["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","Phase-contrast x-ray imaging and tomography of the nematode Caenorhabditis elegans"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["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.artnumber","09973"],["dc.bibliographiccitation.journal","Scientific Reports"],["dc.bibliographiccitation.volume","5"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Markus, Andrea"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Dullin, Christian"],["dc.contributor.author","Alves, Frauke"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:44:24Z"],["dc.date.available","2017-09-07T11:44:24Z"],["dc.date.issued","2015"],["dc.description.abstract","We have performed x-ray phase-contrast tomography on mouse lung tissue. Using a divergent x-ray beam generated by nanoscale focusing, we used zoom tomography to produce three-dimensional reconstructions with selectable magnification, resolution, and field of view. Thus, macroscopic tissue samples extending over several mm can be studied in sub-cellular-level structural detail. The zoom capability and, in particular, the high dose efficiency are enabled by the near-perfect exit wavefront of an optimized x-ray waveguide channel. In combination with suitable phase-retrieval algorithms, challenging radiation-sensitive and low-contrast samples can be reconstructed with minimal artefacts. The dose efficiency of the method is demonstrated by the reconstruction of living macrophages both with and without phagocytized contrast agents. We also used zoom tomography to visualize barium-labelled macrophages in the context of morphological structures in asthmatic and healthy mouse lung tissue one day after intratracheal application. The three-dimensional reconstructions showed that the macrophages predominantly localized to the alveoli, but they were also found in bronchial walls, indicating that these cells might be able to migrate from the lumen of the bronchi through the epithelium."],["dc.identifier.doi","10.1038/srep09973"],["dc.identifier.fs","615791"],["dc.identifier.gro","3141904"],["dc.identifier.isi","000354310200001"],["dc.identifier.pmid","25966338"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/13625"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2367"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","2045-2322"],["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 4.0"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.subject.mesh","Animals"],["dc.subject.mesh","Cell Line, Transformed"],["dc.subject.mesh","Cell Movement"],["dc.subject.mesh","Macrophages, Alveolar"],["dc.subject.mesh","Mice"],["dc.subject.mesh","Pulmonary Alveoli"],["dc.subject.mesh","Respiratory Mucosa"],["dc.subject.mesh","Tomography, X-Ray"],["dc.title","Phase-contrast zoom tomography reveals precise locations of macrophages in mouse lungs"],["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","9212-26"],["dc.contributor.author","Krenkel, Martin"],["dc.contributor.author","Töpperwien, Mareike"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Lingor, Paul"],["dc.contributor.author","Schild, Detlev"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.editor","Stock, Stuart R."],["dc.date.accessioned","2017-09-07T11:54:06Z"],["dc.date.available","2017-09-07T11:54:06Z"],["dc.date.issued","2014"],["dc.description.abstract","We use propagation based hard x-ray phase contrast tomography to explore the three dimensional structure of neuronal tissues from the organ down to sub-cellular level, based on combinations of synchrotron radiation and laboratory sources. To this end a laboratory based microfocus tomography setup has been built in which the geometry was optimized for phase contrast imaging and tomography. By utilizing phase retrieval algorithms, quantitative reconstructions can be obtained that enable automatic renderings without edge artifacts. A high brightness liquid metal microfocus x-ray source in combination with a high resolution detector yielding a resolution down to 1.5 μm. To extend the method to nanoscale resolution we use a divergent x-ray waveguide beam geometry at the synchrotron. Thus, the magnification can be easily tuned by placing the sample at different defocus distances. Due to the small Fresnel numbers in this geometry the measured images are of holographic nature which poses a challenge in phase retrieval."],["dc.identifier.doi","10.1117/12.2060390"],["dc.identifier.gro","3145112"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2812"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.status","public"],["dc.publisher","SPIE"],["dc.publisher.place","Bellingham, Washington"],["dc.relation.conference","9th Conference Developments in X-Ray Tomography"],["dc.relation.eventend","2014-08-20"],["dc.relation.eventlocation","San Diego, Calif."],["dc.relation.eventstart","2014-08-18"],["dc.relation.ispartof","Developments in X-Ray Tomography IX"],["dc.relation.issn","0277-786X"],["dc.relation.orgunit","Institut für Röntgenphysik"],["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","X-ray phase contrast tomography from whole organ down to single cells"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]