Giewekemeyer, Klaus

[["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.volume","303"],["dc.contributor.author","Koelsch, P."],["dc.contributor.author","Viswanath, R."],["dc.contributor.author","Motschmann, H."],["dc.contributor.author","Shapovalov, V. L."],["dc.contributor.author","Brezesinski, G."],["dc.contributor.author","Moehwald, H."],["dc.contributor.author","Horinek, D."],["dc.contributor.author","Netz, R. R."],["dc.contributor.author","Giewekemeyer, K."],["dc.contributor.author","Salditt, T."],["dc.contributor.author","Schollmeyer, H."],["dc.contributor.author","Von Klitzing, R."],["dc.contributor.author","Daillant, J."],["dc.contributor.author","Guenoun, P."],["dc.date.accessioned","2017-09-07T11:49:26Z"],["dc.date.available","2017-09-07T11:49:26Z"],["dc.date.issued","2007"],["dc.description.abstract","Charged surfaces and ion-water interactions at an interface play a decisive role in many physico-chemical and biological processes. The classical treatment of ions at charged interfaces is the Poisson-Boltzmann (PB) theory. Despite severe simplifying assumptions it describes surprisingly well univalent ions not too close to the interface for low electrolyte concentrations in the mmol regime. However, it breaks down in the vicinity of the interface at higher surface charge densities. Consequently the list of decorations and modifications of the original PB equation is long aiming for a more realistic picture. One striking deficiency of the treatment on the pure electrostatic level is the prediction that ions of the same valence produce the same results, independent of their chemical nature. In contrast, experiments reveal pronounced differences between different ions. Specific ion effects can be found everywhere in chemistry and biology and there are many reports of pronounced differences in the properties of charged monolayers, micelles, vesicles, dispersions or polyelectrolyte multilayers using different identically charged counterions. The so-called \"counterion effect\" is usually discussed in terms of the Hofmeister series for cations or anions which are the result of a subtle balance of several competing evenly matched interactions. The complex interplay of electrostatics, dispersion forces, thermal motion, polarization, fluctuations, hydration, ion size effects and the impact of interfacial water structure makes it hard to identify a universal law. The diversity of specific ion effects is a direct consequence of this subtle interplay of forces and imposes a true challenge for the theories. The decisive information for an assessment of the theories is knowledge of the prevailing ion distribution. Hence a considerable amount of work has been applied to develop suitable model systems and to push surface characterization tools such as (resonant) X-ray reflectivity, total reflection X-ray fluorescence or X-ray standing waves to new limits. These techniques give direct information on the ions and on the interfacial architecture. A second alternative to complement these studies is infrared-visible sum frequency spectroscopy allowing to record surface vibrational spectra of the water as it is perturbed in the presence of the salts. The paper is organized in sections describing various facets of ion specific effects discussed within the network. (c) 2007 Elsevier B.V. All fights reserved."],["dc.identifier.doi","10.1016/j.colsurfa.2007.03.040"],["dc.identifier.gro","3143458"],["dc.identifier.isi","000247771200012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/974"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","French/ German Network on Complex Fluids - From 2D to 3D"],["dc.relation.eissn","1873-4359"],["dc.relation.eventlocation","Paris, FRANCE"],["dc.relation.ispartof","Colloids and Surfaces A: Physicochemical and Engineering Aspects"],["dc.relation.issn","0927-7757"],["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","x-ray scattering"],["dc.subject.gro","molecular biophysics"],["dc.title","Specific ion effects in physicochemical and biological systems: Simulations, theory and experiments"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Neubauer, Heike"],["dc.contributor.author","Krüger, Sven P"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Osterhoff, Markus"],["dc.contributor.author","Mai, Dong-Du"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Hartmann, Britta"],["dc.contributor.author","Sprung, Michael"],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","McNulty, Ian"],["dc.contributor.author","Eyberger, Catherine"],["dc.contributor.author","Lai, Barry"],["dc.date.accessioned","2017-09-07T11:54:07Z"],["dc.date.available","2017-09-07T11:54:07Z"],["dc.date.issued","2011"],["dc.identifier.doi","10.1063/1.3625313"],["dc.identifier.gro","3145117"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2818"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.status","public"],["dc.publisher","AIP Publishing"],["dc.publisher.place","Melville, NY"],["dc.relation","SFB 755: Nanoscale Photonic Imaging"],["dc.relation.conference","10th International Conference on X-Ray Microscopy"],["dc.relation.eventend","2010-08-20"],["dc.relation.eventlocation","Chicago, Illinois"],["dc.relation.eventstart","2010-08-15"],["dc.relation.isbn","0-7354-0925-0"],["dc.relation.isbn","978-0-7354-0925-5"],["dc.relation.ispartof","The 10th International Conference on X-Ray Microscopy"],["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","The Göttingen Holography Endstation of Beamline P10 at PETRA III∕DESY"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","18003"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Europhysics Letters (EPL)"],["dc.bibliographiccitation.volume","79"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:49:27Z"],["dc.date.available","2017-09-07T11:49:27Z"],["dc.date.issued","2007"],["dc.description.abstract","We study the bromide counterion distribution near a solid-supported monolayer in the case of vanishing bulk electrolyte concentration by resonant X-ray reflectivity. The surface charge density of the monolayer was varied by using different molar ratios of the cationic Di-Octadecyl-Di-methyl-Ammonium-Bromide (DODAB) and the neutral Di-Palmitoyl-Glycero-Phosphocholine (DPPC). The analysis, either based on a conventional box model with an additional counterion contribution, or based on an independent unbiased global optimization approach, yields a good agreement with the classical Poisson- Boltzmann theory for the salt-free case. Copyright (c) EPLA, 2007."],["dc.identifier.doi","10.1209/0295-5075/79/18003"],["dc.identifier.gro","3143475"],["dc.identifier.isi","000248798000022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/993"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0295-5075"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray scattering"],["dc.subject.gro","membrane biophysics"],["dc.title","Counterion distribution near a monolayer of variable charge density"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Osterhoff, Markus"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Neubauer, Heike"],["dc.contributor.author","Krüger, Sven P"],["dc.contributor.author","Hartmann, Britta"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Sprung, Michael"],["dc.contributor.author","Leupold, O."],["dc.contributor.author","Siewert, F."],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Garrett, R."],["dc.contributor.author","Gentle, I."],["dc.contributor.author","Nugent, K."],["dc.contributor.author","Wilkins, S."],["dc.date.accessioned","2017-09-07T11:54:07Z"],["dc.date.available","2017-09-07T11:54:07Z"],["dc.date.issued","2010"],["dc.identifier.doi","10.1063/1.3463233"],["dc.identifier.gro","3145119"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/2820"],["dc.language.iso","en"],["dc.notes.intern","Crossref Import"],["dc.notes.status","public"],["dc.publisher","AIP Publishing"],["dc.publisher.place","Melville, NY"],["dc.relation","SFB 755: Nanoscale Photonic Imaging"],["dc.relation.conference","10th International Conference on Synchrotron Radiation Instrumentation"],["dc.relation.eventend","2009-10-02"],["dc.relation.eventlocation","Melbourne, Australia"],["dc.relation.eventstart","2009-09-27"],["dc.relation.isbn","978-0-7354-0782-4"],["dc.relation.ispartof","SRI 2009: the 10th International Conference on Synchrotron Radiation Instrumentation"],["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","The holography endstation of beamline P10 at PETRA III"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","295"],["dc.bibliographiccitation.lastpage","296"],["dc.bibliographiccitation.volume","2007"],["dc.contributor.author","Beerlink, André"],["dc.contributor.author","Boye, P."],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Gulden, Johannes"],["dc.contributor.author","Meents, Alke"],["dc.contributor.author","Neubauer, H."],["dc.contributor.author","Schropp, Andreas"],["dc.contributor.author","Stephan, S."],["dc.contributor.author","Salditt, Tim"],["dc.contributor.author","Schroer, Christian G."],["dc.contributor.author","Vartaniants, I."],["dc.contributor.author","Weckert, E."],["dc.date.accessioned","2020-03-11T10:13:50Z"],["dc.date.available","2020-03-11T10:13:50Z"],["dc.date.issued","2007"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63298"],["dc.language.iso","en"],["dc.notes.preprint","yes"],["dc.relation.crisseries","Jahresbericht (Hamburger Synchrotronstrahlungslabor am Deutschen Elektronen-Synchrotron DESY)"],["dc.relation.eventend","2007"],["dc.relation.eventlocation","Hamburg"],["dc.relation.eventstart","2007"],["dc.relation.iserratumof","yes"],["dc.relation.ispartofseries","HASYLAB Jahresbericht;"],["dc.title","Coherent X-ray Diffraction Measurements at the cSAX beamline at SLS"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","051604"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Physical Review E"],["dc.bibliographiccitation.volume","77"],["dc.contributor.author","Hohage, Thorsten"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:48:45Z"],["dc.date.available","2017-09-07T11:48:45Z"],["dc.date.issued","2008"],["dc.description.abstract","Analysis of x-ray and neutron reflectivity is usually performed by modeling the density profile of the sample and performing a least square fit to the measured (phaseless) reflectivity data. Here we address the uniqueness of the reflectivity problem as well as its numerical reconstruction. In particular, we derive conditions for uniqueness, which are applicable in the kinematic limit (Born approximation), and for the most relevant case of box model profiles with Gaussian roughness. At the same time we present an iterative method to reconstruct the profile based on regularization methods. The method is successfully implemented and tested both on simulated and real experimental data."],["dc.identifier.doi","10.1103/PhysRevE.77.051604"],["dc.identifier.gro","3143313"],["dc.identifier.isi","000256885400068"],["dc.identifier.pmid","18643076"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/814"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1539-3755"],["dc.relation.orgunit","Institut für Numerische und Angewandte Mathematik"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray scattering"],["dc.title","Iterative reconstruction of a refractive-index profile from x-ray or neutron reflectivity measurements"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","051911"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Physical Review E"],["dc.bibliographiccitation.volume","74"],["dc.contributor.author","Nováková, Eva"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:52:30Z"],["dc.date.available","2017-09-07T11:52:30Z"],["dc.date.issued","2006"],["dc.description.abstract","We report an x-ray reflectivity study of phospholipid membranes deposited on silicon by vesicle fusion. The samples investigated were composed of single phospholipid bilayers as well as two-component lipid bilayer systems with varied charge density. We show that the resolution obtained in the density profile across the bilayer is high enough to distinguish two head-group maxima in the profile if the sample is in the phase coexistence regime. The water layer between the bilayer and silicon is found to depend on the lipid surface charge density."],["dc.identifier.doi","10.1103/PhysRevE.74.051911"],["dc.identifier.gro","3143606"],["dc.identifier.isi","000242408700081"],["dc.identifier.pmid","17279943"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/1139"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1539-3755"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.subject.gro","x-ray scattering"],["dc.subject.gro","membrane biophysics"],["dc.title","Structure of two-component lipid membranes on solid support: An x-ray reflectivity study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","023804"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Physical Review A"],["dc.bibliographiccitation.volume","83"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Krueger, S. P."],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Bartels, Matthias"],["dc.contributor.author","Beta, C."],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2017-09-07T11:44:21Z"],["dc.date.available","2017-09-07T11:44:21Z"],["dc.date.issued","2011"],["dc.description.abstract","We have used x-ray waveguides as highly confining optical elements for nanoscale imaging of unstained biological cells using the simple geometry of in-line holography. The well-known twin-image problem is effectively circumvented by a simple and fast iterative reconstruction. The algorithm which combines elements of the classical Gerchberg-Saxton scheme and the hybrid-input-output algorithm is optimized for phase-contrast samples, well-justified for imaging of cells at multi-keV photon energies. The experimental scheme allows for a quantitative phase reconstruction from a single holographic image without detailed knowledge of the complex illumination function incident on the sample, as demonstrated for freeze-dried cells of the eukaryotic amoeba Dictyostelium discoideum. The accessible resolution range is explored by simulations, indicating that resolutions on the order of 20 nm are within reach applying illumination times on the order of minutes at present synchrotron sources."],["dc.identifier.doi","10.1103/PhysRevA.83.023804"],["dc.identifier.gro","3142778"],["dc.identifier.isi","000287029900011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/219"],["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","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 optics"],["dc.subject.gro","x-ray imaging"],["dc.title","X-ray propagation microscopy of biological cells using waveguides as a quasipoint source"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","s74"],["dc.bibliographiccitation.issue","a1"],["dc.bibliographiccitation.journal","Acta Crystallographica. Section A, Foundations and Advances"],["dc.bibliographiccitation.lastpage","s74"],["dc.bibliographiccitation.volume","65"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Kalbfleisch, Sebastian"],["dc.contributor.author","Beerlink, André"],["dc.contributor.author","Kewish, Cameron M."],["dc.contributor.author","Thibault, Pierre"],["dc.contributor.author","Pfeiffer, Franz"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2020-03-11T09:54:42Z"],["dc.date.available","2020-03-11T09:54:42Z"],["dc.date.issued","2009"],["dc.identifier.doi","10.1107/S0108767309098560"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63297"],["dc.language.iso","en"],["dc.relation.issn","0108-7673"],["dc.title","Highly sensitive quantitative biological imaging by scanning X-ray diffraction microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","064702"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Structural Dynamics"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Yefanov, Oleksandr"],["dc.contributor.author","Oberthür, Dominik"],["dc.contributor.author","Bean, Richard"],["dc.contributor.author","Wiedorn, Max O."],["dc.contributor.author","Knoska, Juraj"],["dc.contributor.author","Pena, Gisel"],["dc.contributor.author","Awel, Salah"],["dc.contributor.author","Gumprecht, Lars"],["dc.contributor.author","Domaracky, Martin"],["dc.contributor.author","Sarrou, Iosifina"],["dc.contributor.author","Lourdu Xavier, P."],["dc.contributor.author","Metz, Markus"],["dc.contributor.author","Bajt, Saša"],["dc.contributor.author","Mariani, Valerio"],["dc.contributor.author","Gevorkov, Yaroslav"],["dc.contributor.author","White, Thomas A."],["dc.contributor.author","Tolstikova, Aleksandra"],["dc.contributor.author","Villanueva-Perez, Pablo"],["dc.contributor.author","Seuring, Carolin"],["dc.contributor.author","Aplin, Steve"],["dc.contributor.author","Estillore, Armando D."],["dc.contributor.author","Küpper, Jochen"],["dc.contributor.author","Klyuev, Alexander"],["dc.contributor.author","Kuhn, Manuela"],["dc.contributor.author","Laurus, Torsten"],["dc.contributor.author","Graafsma, Heinz"],["dc.contributor.author","Monteiro, Diana C. F."],["dc.contributor.author","Trebbin, Martin"],["dc.contributor.author","Maia, Filipe R. N. C."],["dc.contributor.author","Cruz-Mazo, Francisco"],["dc.contributor.author","Gañán-Calvo, Alfonso M."],["dc.contributor.author","Heymann, Michael"],["dc.contributor.author","Darmanin, Connie"],["dc.contributor.author","Abbey, Brian"],["dc.contributor.author","Schmidt, Marius"],["dc.contributor.author","Fromme, Petra"],["dc.contributor.author","Giewekemeyer, Klaus"],["dc.contributor.author","Sikorski, Marcin"],["dc.contributor.author","Graceffa, Rita"],["dc.contributor.author","Vagovic, Patrik"],["dc.contributor.author","Kluyver, Thomas"],["dc.contributor.author","Bergemann, Martin"],["dc.contributor.author","Fangohr, Hans"],["dc.contributor.author","Sztuk-Dambietz, Jolanta"],["dc.contributor.author","Hauf, Steffen"],["dc.contributor.author","Raab, Natascha"],["dc.contributor.author","Bondar, Valerii"],["dc.contributor.author","Mancuso, Adrian P."],["dc.contributor.author","Chapman, Henry N."],["dc.contributor.author","Barty, Anton"],["dc.date.accessioned","2020-03-03T08:07:43Z"],["dc.date.available","2020-03-03T08:07:43Z"],["dc.date.issued","2019"],["dc.description.abstract","The new European X-ray Free-Electron Laser (European XFEL) is the first X-ray free-electron laser capable of delivering intense X-ray pulses with a megahertz interpulse spacing in a wavelength range suitable for atomic resolution structure determination. An outstanding but crucial question is whether the use of a pulse repetition rate nearly four orders of magnitude higher than previously possible results in unwanted structural changes due to either radiation damage or systematic effects on data quality. Here, separate structures from the first and subsequent pulses in the European XFEL pulse train were determined, showing that there is essentially no difference between structures determined from different pulses under currently available operating conditions at the European XFEL."],["dc.identifier.doi","10.1063/1.5124387"],["dc.identifier.pmid","31832488"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63064"],["dc.language.iso","en"],["dc.relation.issn","2329-7778"],["dc.title","Evaluation of serial crystallographic structure determination within megahertz pulse trains"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]