Pieper, Christoph M.

[["dc.bibliographiccitation.firstpage","175"],["dc.bibliographiccitation.lastpage","204"],["dc.bibliographiccitation.seriesnr","518"],["dc.contributor.author","Pieper, Christoph"],["dc.contributor.author","Weiß, Kerstin"],["dc.contributor.author","Gregor, Ingo"],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:49:29Z"],["dc.date.available","2018-04-23T11:49:29Z"],["dc.date.issued","2013"],["dc.description.abstract","This chapter introduces into the technique of dual-focus fluorescence correlation spectroscopy or 2fFCS. In 2fFCS, the fluorescence signals generated in two laterally shifted but overlapping focal regions are auto- and crosscorrelated. The resulting correlation curves are then used to determine diffusion coefficients of fluorescent molecules or particles in solutions or membranes. Moreover, the technique can also be used for noninvasively measuring flow-velocity profiles in three dimensions. Because the distance between the focal regions is precisely known and not changed by most optical aberrations, this provides an accurate and immutable external length scale for determining diffusivities and velocities, making 2fFCS the method of choice for accurately measuring absolute values of these quantities at pico- to nanomolar concentration."],["dc.identifier.doi","10.1016/b978-0-12-388422-0.00008-x"],["dc.identifier.gro","3142130"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13711"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/103104"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.publisher","Elsevier"],["dc.relation.crisseries","Methods in Enzymology"],["dc.relation.isbn","978-0-12-388422-0"],["dc.relation.ispartof","Methods in Enzymology"],["dc.relation.issn","0076-6879"],["dc.title","Dual-Focus Fluorescence Correlation Spectroscopy"],["dc.type","book_chapter"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4651"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Polymer"],["dc.bibliographiccitation.lastpage","4657"],["dc.bibliographiccitation.volume","55"],["dc.contributor.author","Wiśniewska, Agnieszka"],["dc.contributor.author","Sozański, Krzysztof"],["dc.contributor.author","Kalwarczyk, Tomasz"],["dc.contributor.author","Kędra-Królik, Karolina"],["dc.contributor.author","Pieper, Christoph"],["dc.contributor.author","Wieczorek, Stefan A."],["dc.contributor.author","Jakieła, Sławomir"],["dc.contributor.author","Enderlein, Jörg"],["dc.contributor.author","Hołyst, Robert"],["dc.date.accessioned","2018-04-23T11:49:26Z"],["dc.date.available","2018-04-23T11:49:26Z"],["dc.date.issued","2014"],["dc.description.abstract","We postulate an empirical scaling equation, which accurately describes flow of polymer solutions, complimenting the paradigm of length-scale-dependent viscosity. We investigated poly(ethylene glycol) aqueous solutions and observed an exponential dependence of viscosity on the hydrodynamic radius of a single coil Rh divided by the correlation length ξ. Properties of the system changed abruptly with the onset of chain entanglement at concentration corresponding to ξ = Rh. We propose a single equation valid for all the investigated systems, analyze the physical meaning of parameters appearing therein and discuss the impact of chain entanglement. Viscous flow is treated as an activated process, following the Eyring rate theory. We show that the difference of activation energy for flow between pure solvent and polymer solution, ΔEa, is a function of concentration, whose derivative has a discontinuity at the crossover concentration. For dilute PEG solutions ΔEa takes values of up to several kJ/mol and is proportional to the intrinsic viscosity. We successfully apply the scaling approach to the diffusive motion of a protein (aldolase) in solutions of 25 kg/mol PEO (concentrations of 2–20%), investigated by fluorescence correlation spectroscopy (FCS). A significant difference in the influence of crowding on translational and rotational motion of the protein is revealed."],["dc.identifier.doi","10.1016/j.polymer.2014.07.029"],["dc.identifier.gro","3142117"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13697"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.issn","0032-3861"],["dc.title","Scaling of activation energy for macroscopic flow in poly(ethylene glycol) solutions: Entangled - Non-entangled crossover"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1-3"],["dc.bibliographiccitation.journal","Chemical Physics Letters"],["dc.bibliographiccitation.lastpage","11"],["dc.bibliographiccitation.volume","516"],["dc.contributor.author","Pieper, Christoph M."],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:49:31Z"],["dc.date.available","2018-04-23T11:49:31Z"],["dc.date.issued","2011"],["dc.description.abstract","We give an overview of using fluorescence correlation spectroscopy (FCS) for measuring rotational diffusion of macromolecules, and present a new experimental scheme, pulsed-interleaved excitation or PIE-FCS, which allows for measuring all conceivable correlation curves of a polarization-sensitive FCS experiment. After giving a brief review of the theoretical foundations, we systematically study the impact of different experimentally relevant parameters such as depolarization by the objective, or non-collinearity between absorption and emission dipole of the fluorescent label. We also discuss the possibility to extract information about anisotropic rotational diffusion, and exemplify that by determining the size and shape of the large protein aldolase."],["dc.identifier.doi","10.1016/j.cplett.2011.06.091"],["dc.identifier.gro","3142138"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13720"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.doi","10.1016/j.cplett.2011.06.091"],["dc.relation.issn","0009-2614"],["dc.title","Fluorescence correlation spectroscopy as a tool for measuring the rotational diffusion of macromolecules"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1937"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Soft Matter"],["dc.bibliographiccitation.lastpage","1946"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Sengupta, Anupam"],["dc.contributor.author","Pieper, Christoph"],["dc.contributor.author","Enderlein, Jörg"],["dc.contributor.author","Bahr, Christian"],["dc.contributor.author","Herminghaus, Stephan"],["dc.date.accessioned","2017-09-07T11:51:51Z"],["dc.date.available","2017-09-07T11:51:51Z"],["dc.date.issued","2012"],["dc.description.abstract","We study the flow of a nematic liquid crystal past a micron-sized cylindrical pillar within a microfluidic confinement of a rectangular cross-section. The liquid crystal molecules are anchored perpendicularly (homeotropic anchoring) to the surface of the pillar and the channel walls. Flow past the cylindrical obstacle generated topological defect structures whose nature, dimensions and morphology varied with the flow velocity and channel dimensions. On increasing the flow speed, we observed sequential evolution of a semi-integer loop, which transformed into an integer hedgehog defect, and finally equilibrated to an extended defect wall. On stopping the flow, the topological defect states reversed its sequence of appearance. Additionally, we introduce dual-focus fluorescence correlation spectroscopy as a general velocimetry technique for microfluidics of liquid crystal systems – with or without topological defect structures."],["dc.identifier.doi","10.1039/c2sm27337c"],["dc.identifier.gro","3146188"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10477"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/3943"],["dc.language.iso","en"],["dc.notes","This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively."],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.relation","info:eu-repo/grantAgreement/EC/FP7/215851/EU//HIERARCHY"],["dc.relation.issn","1744-683X"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Flow of a nematogen past a cylindrical micro-pillar"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","21000"],["dc.bibliographiccitation.issue","52"],["dc.bibliographiccitation.journal","Proceedings of the National Academy of Sciences of the United States of America"],["dc.bibliographiccitation.lastpage","21005"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","Schulz, Olaf"],["dc.contributor.author","Pieper, Christoph"],["dc.contributor.author","Clever, Michaela"],["dc.contributor.author","Pfaff, Janine"],["dc.contributor.author","Ruhlandt, Aike"],["dc.contributor.author","Kehlenbach, Ralph H."],["dc.contributor.author","Wouters, Fred Silvester"],["dc.contributor.author","Großhans, Jörg"],["dc.contributor.author","Bunt, Gertrude"],["dc.contributor.author","Enderlein, Jörg"],["dc.date.accessioned","2018-04-23T11:49:28Z"],["dc.date.available","2018-04-23T11:49:28Z"],["dc.date.issued","2013"],["dc.description.abstract","We demonstrate how a conventional confocal spinning-disk (CSD) microscope can be converted into a doubly resolving image scanning microscopy (ISM) system without changing any part of its optical or mechanical elements. Making use of the intrinsic properties of a CSD microscope, we illuminate stroboscopically, generating an array of excitation foci that are moved across the sample by varying the phase between stroboscopic excitation and rotation of the spinning disk. ISM then generates an image with nearly doubled resolution. Using conventional fluorophores, we have imaged single nuclear pore complexes in the nuclear membrane and aggregates of GFP-conjugated Tau protein in three dimensions. Multicolor ISM was shown on cytoskeletal-associated structural proteins and on 3D four-color images including MitoTracker and Hoechst staining. The simple adaptation of conventional CSD equipment allows superresolution investigations of a broad variety of cell biological questions."],["dc.identifier.doi","10.1073/pnas.1315858110"],["dc.identifier.gro","3142124"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13705"],["dc.language.iso","en"],["dc.notes.intern","lifescience updates Crossref Import"],["dc.notes.status","final"],["dc.relation.doi","10.1073/pnas.1315858110"],["dc.relation.issn","0027-8424"],["dc.title","Resolution doubling in fluorescence microscopy with confocal spinning-disk image scanning microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]