Ändra sökning
Avgränsa sökresultatet
45678 301 - 350 av 376
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 301.
    Tuohimaa, Tomi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Otendal, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-intensity electron beam for liquid-metal-jet anode hard x-ray generation2005Ingår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 5918Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on our progress towards the experimental realization of a liquid-metal-jet-anode x-ray source with high brightness. We have previously shown that this electron-impact source has potential for very high x-ray brightness by combining small-spot high-flux operation of the electron beam with high-speed operation of the regenerative liquid-metal-jet anode. In the present paper we review the system and describe theoretical calculations for improving the 50 kV, 600 W electron-beam focussing to ∼30 μm spot size. With such a system the power density on the liquid-metal-jet would be ∼400 kW/mm 2, i.e., more than an order of magnitude higher than the power density on a state-of-the-art rotating anode.

  • 302.
    Tuohimaa, Tomi
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Otendal, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Phase-contrast x-ray imaging with a liquid-metal-jet-anode microfocus source2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, nr 7, s. 074104-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phase-contrast methods increase contrast, detail, and selectivity in x-ray imaging. Present compact x-ray sources do not provide the necessary spatial coherence with sufficient power to allow the laboratory-scale high-resolution phase-contrast imaging with adequate exposure times. In this letter, the authors demonstrate phase-contrast imaging with few-micron detail employing a compact similar to 6.5 mu m spot liquid-metal-jet-anode high-brightness microfocus source. The 40 W source is operated at more than ten times higher electron-beam power density than present microfocus sources and is shown to provide sufficient spatial coherence as well as scalability to high power, thereby enabling the application of phase-contrast x-ray imaging with short exposure times in clinics and laboratories.

  • 303.
    Twengström, William
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    High-resolution biomedical phase-contrast tomography2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Förbättrad tredimensionell biomedicinsk avbildning kan ge en bättre förståelse av vävnadsstruktur, tillväxt och sjukdomar. De flesta av dagens avbildningstekniker som ger cellulär upplösning är baserade på synligt eller infrarött ljus. Dessa metoder kan inte avbilda mer än en millimeter ner i vävnad. Därför kan inte större prov avbildas i sin helhet utan att snittas. Tekniker som vanligen används för att avbilda större prover ger inte tillräcklig kontrast och upplösning för att avbilda strukturer av cellulär storlek i mjuk vävnad. Det finns ett behov av nya avbildningsmetoder som kan fylla utrymmet mellan befintliga metoder. Av praktiska skäl föredras att använda kompakt utrustning, för att möjliggöra nära koppling till annan forskning och tillämpningar. Dessutom, minimerade förberedelser av proven reducerar både arbetsinsatsen och tiden tills resultaten är klara.

    I den här doktorsavhandlingen har propagationsbaserad faskontrast- \mbox{tomografi} med metallstråleröntgenkällor undersökts för högupplöst tredimensionell avbildning. Genom att använda faskontrast kan kontrasten för strukturer av cellulär storlek i mjukvävnad ökas markant jämfört med absoption, även i större prover. Den höga upplösningen hänger på användandet av en röntgenkälla med liten emissionsspot, men även med hög effekt för att hålla exponeringstider korta.

    Den här doktorsavhandlingen handlar om att utveckla och optimera experimetella metoder och bildrekonstruktionsalgoritmer. En ny metod för att ta bort ringartefakter utvecklades och testades, och en jämförelse av flermaterials-fasrekonstruktion gjordes. Förbättringarna ger bättre kontrast och upplösning, men minskar också brus och artefakter. Den förbättrade bildkvaliteten visas i några biomedicinska tillämpningar. Det visas att metoden kan avbilda 5 µm stora myofibriller i hela zebrafiskar trots den lilla storleken och låga kontrasten hos myofibriller. En högupplöst tomografi av en mus kan göras snabbt genom att använda en specialiserad högeffektskälla. Bildkvaliteten i tomografier av både mänskliga kranskärl och en mummifierad mänsklig hand är tillräcklig för att analysera vävnader och strukturer av cellulär storlek, vilket är något som skulle kunna kallas virtuell histologi.

    Ladda ner fulltext (pdf)
    fulltext
  • 304.
    Twengström, William
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Persson, Jonas
    Szekely, Laszlo
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Fysik. KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Cellular-resolution 3D virtual histology of human coronary arteries using x-ray phase tomography2018Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikel-id 11014Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-spatial-resolution histology of coronary artery autopsy samples play an important role for understanding heart disease such as myocardial infarction. Unfortunately, classical histology is often destructive, has thick slicing, requires extensive sample preparation, and is time-consuming. X-ray micro-CT provides fast nondestructive 3D imaging but absorption contrast is often insufficient, especially for observing soft-tissue features with high resolution. Here we show that propagation-based x-ray phase-contrast tomography has the resolution and contrast to image clinically relevant soft-tissue features in intact coronary artery autopsy samples with cellular resolution. We observe microscopic lipid-rich plaques, individual adipose cells, ensembles of few foam cells, and the thin fibrous cap. The method relies on a small-spot laboratory x-ray microfocus source, and provides high-spatial resolution in all three dimensions, fast data acquisition, minimum sample distortion and requires no sample preparation.

  • 305.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nanofabrication of Zone Plates for Hard X-Ray Free-Electron Lasers2015Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This Thesis describes the development of hard X-ray zone plates intended for focusing radiation at X-ray free-electron lasers (XFELs). XFELs provide unprecedented brightness and zone plates which are put in the intense X-ray beam are at risk of being damaged. Therefore, it is crucial to perform damage tests in order to design zone plates which can survive the XFEL beam.

    Zone plates are diffractive nanofocusing optics and are regularly used at high brightness synchrotron beamlines in the soft and hard X-ray regime. The resolution of a zone plate is proportional to its outermost zonewidth and thus depends on the smallest feature that can be fabricated. State-of-the-art nanofabrication processes developed for zone plates are able to produce zonewidths down to 10 nm. However, for hard X-rays, the zone plates need to be of sufficient thickness to efficiently focus the radiation. Thus, the limit in the fabrication of hard X-ray zone plates lies in the high aspect-ratios. This Thesis describes two processes developed for high aspect-ratio nanostructuring. The first process uses tungsten as diffractive material. Aspect-ratios up to 1:15 have been accomplished. Furthermore, a mounting method of a central stop directly on the zone plate is also presented. The other fabrication process uses diamond, in which aspect-ratios of 1:30 have been demonstrated. Both processes rely on thin-film deposition techniques, electron-beam lithography, and reactive ion etching. Thanks to the materials’ excellent thermal properties these types of zone plates should be suitable for XFEL applications. Tungsten and diamond diffractive optics have been tested at an XFEL at Stanford (LCLS), and damage investigations were performed in order to determine the maximum fluence that could be imposed on the optics before degradation occured. The conclusion of these damage tests is that tungsten and diamond diffractive optics can survive the XFEL beam and could potentially be used in beamline experiments relying on nanofocused X-ray beams. Finally in this Thesis, characterization of two zone plates using an interferometer is presented, where it is also shown that the interferometric method can be used to pin-point beamline instabilities.

    Ladda ner fulltext (pdf)
    Thesis
  • 306.
    Uhlén, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindqvist, Sandra
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    New diamond nanofabrication process for hard x-ray zone plates2011Ingår i: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 29, nr 6, s. 06FG03-1-06FG03-4Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The authors report on a new tungsten-hardmask-based diamond dry-etch process for fabricating diamond zone plate lenses with a high aspect ratio. The tungsten hardmask is structured by electron-beam lithography, together with Cl2/O2 and SF6/O2 reactive ion etching in a trilayer resist-chromium-tungsten stack. The underlying diamond is then etched in an O2 plasma. The authors demonstrate excellent-quality diamond gratings with half-pitch down to 80 nm and a height of 2.6 μm, as well as zone plates with a 75 μm diameter and 100 nm outermost zone width. The diffraction efficiency of the zone plates is measured to 14.5% at an 8 keV x-ray energy, and the imaging properties were investigated in a scanning microscope arrangement showing sub-100-nm resolution. The imaging and thermal properties of these lenses make them suitable for use with high-brightness x-ray free-electron laser sources.

  • 307.
    Uhlén, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Schroer, C. G.
    Seiboth, F.
    Patommel, J.
    Meier, V.
    Hoppe, R.
    Schropp, A.
    Lee, H. J.
    Nagler, B.
    Galtier, E.
    Krzywinski, J.
    Sinn, H.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Damage investigation on tungsten and diamond diffractive optics at a hard x-ray free-electron laser2013Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 21, nr 7, s. 8051-8061Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Focusing hard x-ray free-electron laser radiation with extremely high fluence sets stringent demands on the x-ray optics. Any material placed in an intense x-ray beam is at risk of being damaged. Therefore, it is crucial to find the damage thresholds for focusing optics. In this paper we report experimental results of exposing tungsten and diamond diffractive optics to a prefocused 8.2 keV free-electron laser beam in order to find damage threshold fluence levels. Tungsten nanostructures were damaged at fluence levels above 500 mJ/cm(2). The damage was of mechanical character, caused by thermal stress variations. Diamond nanostructures were affected at a fluence of 59 000 mJ/cm(2). For fluence levels above this, a significant graphitization process was initiated. Scanning Electron Microscopy (SEM) and mu-Raman analysis were used to analyze exposed nanostructures.

  • 308.
    Uhlén, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Belova, Liubov
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Teknisk materialfysik.
    Schroer, Christian G.
    Seiboth, Frank
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nanofabrication of tungsten zone plates with integrated platinum central stop for hard X-ray applications2014Ingår i: Microelectronic Engineering, ISSN 0167-9317, E-ISSN 1873-5568, Vol. 116, s. 40-43Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a nanofabrication process for producing tungsten zone plates used in hard X-ray applications including a method of integrating a high-energy absorbing central stop with the optic. Tungsten zone plates are structured with electron-beam lithography and subsequent reactive ion etching. The central stop originates from a platinum wire. It is cut to dimension by focused ion beam etching, and afterwards attached to the zone plate center using ion beam induced deposition of platinum. A zone plate with integrated central stop will simplify alignment in hard X-ray scanning microscope arrangements where the 0th order light must be eliminated. The focusing performance of the zone plate device was investigated by scanning coherent diffraction imaging (ptychography) at 8 keV photon energy. We could demonstrate a diffraction-limited focus size of 53 nm diameter full-width-at-half-maximum. Tungsten zone plates with integrated central stops show promising results for use in hard X-ray microscopes at high-brightness facilities.

  • 309.
    Uhlén, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Seiboth, Frank
    Sanz, Claude
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wagner, Ulrich
    Rau, Christoph
    Schroer, Christian G.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ronchi test for characterization of X-ray nanofocusing optics and beamlines2014Ingår i: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 21, s. 1105-1109Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A Ronchi interferometer for hard X-rays is reported in order to characterize the performance of the nanofocusing optics as well as the beamline stability. Characteristic interference fringes yield qualitative data on present aberrations in the optics. Moreover, the visibility of the fringes on the detector gives information on the degree of spatial coherence in the beamline. This enables the possibility to detect sources of instabilities in the beamline like vibrations of components or temperature drift. Examples are shown for two different nanofocusing hard X-ray optics: a compound refractive lens and a zone plate.

  • 310.
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Device and method for demonstrating optical effects2008Patent (Övrig (populärvetenskap, debatt, mm))
  • 311. van der Mooren, M.
    et al.
    Rosén, R.
    Franssen, L.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Piers, P.
    Degradation of visual performance with increasing levels of retinal stray light2016Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 57, nr 13, s. 5443-5448Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE. To quantify the effect of induced stray light on halo size, luminance threshold, and contrast sensitivity. METHODS. Retinal stray light was induced in five healthy subjects using different photographic filters. The stray light induced ranged from levels observed in intraocular lenses (IOLs) with glistenings (low) to cataract level (high). The visual impact was measured for halo size, luminance detection threshold, and contrast sensitivity with and without a glare source. RESULTS. The amount of retinal stray light induced by the different filters was similar when measured using the psychophysical method and the optical bench method. Low amounts of induced stray light cause the halo size to increase by 21%, the luminance detection threshold to increase by 156%, and contrast sensitivity to decrease by 10% to 21% dependent on spatial frequency and presence of a glare source. The visual impact percentages for high amounts of induced stray light were, respectively, 76%, 2130%, and 30% to 49%. In the presence of a glare source, contrast sensitivity losses were larger and shifted to lower spatial frequencies. CONCLUSIONS. Low levels of retinal stray light can cause significant increases in halo sizes, elevations in luminance detection thresholds, and reductions in contrast sensitivity whether or not a glare source is present.

  • 312.
    Van der Mooren, Marrie
    et al.
    AMO Groningen BV, Res & Dev, Groningen, Netherlands..
    Rosen, Robert
    AMO Groningen BV, Res & Dev, Groningen, Netherlands..
    Franssen, Luuk
    AMO Groningen BV, Res & Dev, Groningen, Netherlands..
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Piers, Patricia A.
    AMO Groningen BV, Res & Dev, Groningen, Netherlands..
    Prediction of contrast sensitivity in the presence of glare2017Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 58, nr 8Artikel i tidskrift (Övrigt vetenskapligt)
  • 313. Van der Mooren, Marrie
    et al.
    Steinert, Roger F.
    Tyson, Farrell
    Rosen, Robert
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Piers, Patricia A.
    Understanding visual complaints of two intraocular lens explant cases2015Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 56, nr 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Purpose 

    In two different cases, multifocal intraocular lenses (MFIOLs) were explanted due to visual complications related to the presence of micro-vacuoles in the optic body. These micro-vacuoles cause straylight, which resulted in complaints of hazy and blurry vision. The purpose of this study is to objectively measure and systematically quantify the visual impact of this straylight. The study will thereby give a better understanding of the origin of reported visual complaints when micro-vacuoles are present.

     Methods 

    The amount of straylight in the two explanted MFIOLs was measured using an in-vitro setup and quantified using the scattering parameter s. To determine the impact of straylight on vision, photographic filters characterized in the same in-vitro setup were used to induce straylight on five subjects. Four different psychophysical visual tests were used: halo size, luminance detection with a glare source, and contrast sensitivity (CS) with and without the presence of glare. For all tests, the impact was modeled as a linear interpolation of the logarithm of the test score against the logarithm of the scattering parameter, log(s).

     Results 

    The straylight measured by the in-vitro setup was 6 deg2/sr for case 1 and 4 deg2/sr for case 2. Assuming a base straylight level of 1.1 log(s), the induced increase for the two patients was 0.17 log(s) and 0.12 log(s) respectively.<br /> The impact for the visual tests per unit of log(s) was the following: for halo size, 0.55 log(degrees)/log(s); for luminance detection 2.72 log(cd/m2)/log(s); for CS without glare, 0.33 log(CS)/log(s); and for CS with glare, 0.58 log(CS)/log(s). The induced straylight for the two explanted MFIOLs therefore corresponds to an increase of halo size of 24% and 16%, a luminance detection threshold increase of 190% and 112%, a contrast sensitivity decrease of 12% and 9% without a glare source, and a contrast sensitivity decrease of 20% and 9% with a glare source.

     Conclusions 

    In the explanted MFIOLs we could objectively measure straylight. This straylight corresponds psychophysically to increases in halo size, loss of luminance sensitivity and decrease in contrast sensitivity. Among the visual tests, measurement of luminance detection showed the highest sensitivity.

  • 314.
    Vanherberghen, Bruno
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Manneberg, Otto
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Frisk, Thomas
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Ohlin, Mathias
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Önfelt, Björn
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Wiklund, Martin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ultrasound-controlled cell aggregation in a multi-well chip2010Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 10, nr 20, s. 2727-2732Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate a microplate platform for parallelized manipulation of particles or cells by frequency-modulated ultrasound. The device, consisting of a silicon-glass microchip and a single ultrasonic transducer, enables aggregation, positioning and high-resolution microscopy of cells distributed in an array of 100 microwells centered on the microchip. We characterize the system in terms of temperature control, aggregation and positioning efficiency, and cell viability. We use time-lapse imaging to show that cells continuously exposed to ultrasound are able to divide and remain viable for at least 12 hours inside the device. Thus, the device can be used to induce and maintain aggregation in a parallelized fashion, facilitating long-term microscopy studies of, e.g., cell-cell interactions.

  • 315.
    Vanherberghen, Bruno
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Manneberg, Otto
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Frisk, Thomas
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Önfelt, Björn
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Wiklund, Martin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Highly parallelized cell aggregation by ultrasound for studies of immune cell interaction2009Konferensbidrag (Övrigt vetenskapligt)
  • 316.
    Venkataraman, Abinaya Priya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vision Beyond the Fovea: Evaluation and Stimuli Properties2016Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Denna forskning handlar om att utvärdera synen i periferin. Vår perifera syn är ovärderlig i det dagliga livet. Målsättningen med denna avhandling är dels att utveckla metoder speciellt lämpade för perifer synutvärdering och dels att mäta hur olika synfunktioner varierar över synfältet. Resultaten har tillämpning både inom synrehabilitering för personer med centraltsynfältsbortfall och inom närsynthetsforskning.

    Adaptiv psykofysisk metodologi baserad på Bayesiansk statistik användes vid all utvärdering av det perifera seendet. Vi implementerade en rutin för tidseffektiv mätning av perifer kontrastkänslighet och verifierade den ut till 30° i synfältet. Den perifera synen utvärderades för olika egenskaper hos objektet: skärpa, rörelse, riktning och utbredning. Skärpan kontrollerades med hjälp av adaptiv optik och/eller glasögonkorrektion speciellt anpassad för den perifera synvinkeln. Vi fann att många periferasynfunktioner förbättras av optisk korrektion, särskilt för personer med centralt synfältsbortfall. Vi hittade även förbättringar i periferkontrastkänslighet för låga ortsfrekvenser när objektet modulerades med hastigheter mellan 5 och 10 Hz, vilket gäller både normalseende och personer med centralt synfältsbortfall. I periferin är det lättare att se linjer som är orienterade parallellt med synfältsmeridianen. Vi har visat att denna riktningsbias gäller både för upplösning och detektion i periferin, även när de asymmetriska optiska felen minimeras. För bästa mätnoggrannhet rekommenderar vi därför att använda randmönster som ligger snett relativt synfältsmeridianen. Denna riktningsbias skulle även kunna påverka hur den perifera bildkvalitén inverkar på utvecklingen av närsynthet. Ytterligare ett bevis för att perifer syn kan påverka den centrala synfunktionen är att, när objektets utbredning ökades, uppfattade personen det som mindre suddigt.

    Ladda ner fulltext (pdf)
    fulltext
  • 317.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lewis, Peter
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Peripheral contrast sensitivity for drifting stimuliManuskript (preprint) (Övrigt vetenskapligt)
  • 318. Venkataraman, Abinaya Priya
    et al.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lewis, Peter
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Peripheral resolution and contrast sensitivity: Effects of stimulus drift2017Ingår i: Vision Research, ISSN 0042-6989, E-ISSN 1878-5646, s. 145-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Optimal temporal modulation of the stimulus can improve foveal contrast sensitivity. This study evaluates the characteristics of the peripheral spatiotemporal contrast sensitivity function in normal-sighted subjects. The purpose is to identify a temporal modulation that can potentially improve the remaining peripheral visual function in subjects with central visual field loss. High contrast resolution cut-off for grating stimuli with four temporal frequencies (0, 5, 10 and 15 Hz drift) was first evaluated in the 10° nasal visual field. Resolution contrast sensitivity for all temporal frequencies was then measured at four spatial frequencies between 0.5 cycles per degree (cpd) and the measured stationary cut-off. All measurements were performed with eccentric optical correction. Similar to foveal vision, peripheral contrast sensitivity is highest for a combination of low spatial frequency and 5–10 Hz drift. At higher spatial frequencies, there was a decrease in contrast sensitivity with 15 Hz drift. Despite this decrease, the resolution cut-off did not vary largely between the different temporal frequencies tested. Additional measurements of contrast sensitivity at 0.5 cpd and resolution cut-off for stationary (0 Hz) and 7.5 Hz stimuli performed at 10, 15, 20 and 25° in the nasal visual field also showed the same characteristics across eccentricities.

  • 319.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Winter, Simon
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik. Royal Inst Technol, KTH, Biomed & Xray Phys, Stockholm, Sweden..
    Small and Large Field Blur Adaptation: Foveal and Peripheral Contrast Sensitivity Changes2014Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 55, nr 13Artikel i tidskrift (Övrigt vetenskapligt)
  • 320.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Papadogiannis, Petros
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Romashchenko, Dmitry
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Winter, Simon
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Peripheral resolution and contrast sensitivity: effects of monochromatic and chromatic aberrations2019Ingår i: Optical Society of America. Journal A: Optics, Image Science, and Vision, ISSN 1084-7529, E-ISSN 1520-8532, Vol. 36, nr 4, s. B52-B57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Correction and manipulation of peripheral refractive errors are indispensable for people with central vision loss and in optical interventions for myopia control. This study investigates further enhancements of peripheral vision by compensating for monochromatic higher-order aberrations (with an adaptive optics system) and chromatic aberrations (with a narrowband green filter, 550 nm) in the 20 degrees nasal visual field. Both high-contrast detection cutoff and contrast sensitivity improved with optical correction. This improvement was most evident for gratings oriented perpendicular to the meridian due to asymmetric optical errors. When the natural monochromatic higher-order aberrations are large, resolution of 10% contrast oblique gratings can also be improved with correction of these errors. Though peripheral vision is mainly limited by refractive errors and neural factors, higher-order aberration correction beyond conventional refractive errors can still improve peripheral vision under certain circumstances.

  • 321.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Radhakrishnan, A.
    Dorronsoro, C.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Marcos, S.
    Role of parafovea in blur perception2017Ingår i: Vision Research, ISSN 0042-6989, E-ISSN 1878-5646, Vol. 138, s. 59-65Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The blur experienced by our visual system is not uniform across the visual field. Additionally, lens designs with variable power profile such as contact lenses used in presbyopia correction and to control myopia progression create variable blur from the fovea to the periphery. The perceptual changes associated with varying blur profile across the visual field are unclear. We therefore measured the perceived neutral focus with images of different angular subtense (from 4° to 20°) and found that the amount of blur, for which focus is perceived as neutral, increases when the stimulus was extended to cover the parafovea. We also studied the changes in central perceived neutral focus after adaptation to images with similar magnitude of optical blur across the image or varying blur from center to the periphery. Altering the blur in the periphery had little or no effect on the shift of perceived neutral focus following adaptation to normal/blurred central images. These perceptual outcomes should be considered while designing bifocal optical solutions for myopia or presbyopia.

  • 322.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Radhakrishnan, Aiswaryah
    Dorronsoro, Carlos
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Marcos, Susana
    Effect of parafovea on blur perceptionManuskript (preprint) (Övrigt vetenskapligt)
  • 323.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Winter, Simon
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rosén, Robert
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Choice of grating orientation for evaluation of peripheral vision2016Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 93, nr 6, s. 567-574Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: Peripheral resolution acuity depends on the orientation of the stimuli. However, it is uncertain if such a meridional effect also exists for peripheral detection tasks because they are affected by optical errors. Knowledge of the quantitative differences in acuity for different grating orientations is crucial for choosing the appropriate stimuli for evaluations of peripheral resolution and detection tasks. We assessed resolution and detection thresholds for different grating orientations in the peripheral visual field.

    Methods: Resolution and detection thresholds were evaluated for gratings of four different orientations in eight different visual field meridians in the 20-deg visual field in white light. Detection measurements in monochromatic light (543 nm; bandwidth, 10 nm) were also performed to evaluate the effects of chromatic aberration on the meridional effect. A combination of trial lenses and adaptive optics system was used to correct the monochromatic lower- and higher-order aberrations.

    Results: For both resolution and detection tasks, gratings parallel to the visual field meridian had better threshold compared with the perpendicular gratings, whereas the two oblique gratings had similar thresholds. The parallel and perpendicular grating acuity differences for resolution and detection tasks were 0.16 logMAR and 0.11 logMAD, respectively. Elimination of chromatic errors did not affect the meridional preference in detection acuity.

    Conclusions: Similar to peripheral resolution, detection also shows a meridional effect that appears to have a neural origin. The threshold difference seen for parallel and perpendicular gratings suggests the use of two oblique gratings as stimuli in alternative forced-choice procedures for peripheral vision evaluation to reduce measurement variation.

  • 324.
    Venkataraman, Abinaya Priya
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Winter, Simon
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lundström, Linda
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Blur adaptation: Contrast sensitivity changes and stimulus extent2015Ingår i: Vision Research, ISSN 0042-6989, E-ISSN 1878-5646, Vol. 110, nr PA, s. 100-106Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A prolonged exposure to foveal defocus is well known to affect the visual functions in the fovea. However, the effects of peripheral blur adaptation on foveal vision, or vice versa, are still unclear. In this study, we therefore examined the changes in contrast sensitivity function from baseline, following blur adaptation to small as well as laterally extended stimuli in four subjects. The small field stimulus (7.5° visual field) was a 30. min video of forest scenery projected on a screen and the large field stimulus consisted of 7-tiles of the 7.5° stimulus stacked horizontally. Both stimuli were used for adaptation with optical blur (+2.00. D trial lens) as well as for clear control conditions. After small field blur adaptation foveal contrast sensitivity improved in the mid spatial frequency region. However, these changes neither spread to the periphery nor occurred for the large field blur adaptation. To conclude, visual performance after adaptation is dependent on the lateral extent of the adaptation stimulus.

  • 325.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Köhler, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Dickmann, Jannis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Parfeniukas, Karolis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Kubsky, S.
    Alves, F.
    Langlois, F.
    Engblom, C.
    Stankevič, T.
    Moiré method for nanometer instability investigation of scanning hard x-ray microscopes2017Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 25, nr 11, s. 12188-12194Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a Moiré method that can be used to investigate positional instabilities in a scanning hard x-ray microscope with nanometer precision. The development of diffractionlimited storage rings offering highly-brilliant synchrotron radiation and improvements of nanofocusing x-ray optics paves the way towards 3D nanotomography with 10 nm resolution or below. However, this trend demands improved designs of x-ray microscope instruments which should offer few-nm beam stabilities with respect to the sample. Our technique can measure the position of optics and sample stage relative to each other in the two directions perpendicular to the beam propagation in a scanning x-ray microscope using simple optical components and visible light. The usefulness of the method was proven by measuring short and long term instabilities of a zone-plate-optics-based prototype microscope. We think it can become an important tool for the characterization of scanning x-ray microscopes, especially prior to experiments with an actual x-ray beam.

  • 326.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, M.
    Charalambous, P.
    Kaulich, B.
    Wilhein, T.
    Condenser for Koehler-like illumination in transmission x-ray microscopes at undulator sources2006Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 31, nr 10, s. 1465-1467Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on a novel condenser for full-field transmission x-ray microscopes that use synchrotron radiation from an undulator source. The condenser produces a Koehler-like homogeneous intensity distribution in the sample plane and eliminates object illumination problems connected with the high degree of spatial coherence in an undulator beam. The optic consists of a large number of small linear diffraction gratings and is therefore relatively easy to manufacture. First imaging experiments with a prototype condenser were successfully performed with the Twinmic x-ray microscope at the Elettra synchrotron facility in Italy.

  • 327.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Jansson, Per A. C.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Tuohimaa, Tomi T.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wieland, M.
    Wilhein, M.
    Towards Soft X-Ray Phase-Sensitive Imaging with Diffractive Optical Elements2006Ingår i: Proc. 8th International Conference X-ray Microscopy, 2006, s. 91-93Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this contribution we present the first diffractive optical elements for soft x-ray differential interference contrast microscopy.Due to an improved calculation method the nanofabrication accuracy of these optics is the same as for comparable normal zoneplate optics with the same outermost zone width. Different diffractive optical elements were fabricated with outermost zone widthof 100 nm, different spot separation directions and different phase relations between the two spots. The optics were successfullyused in experiments both at the synchrotron radiation based TWINMIC microscope and at the Stockholm compact liquid-nitrogenlaser-plasma source based microscope.

  • 328.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Jansson, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Tuohimaa, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Wieland, M.
    University of Applied Sciences Koblenz, Rhein Ahr Campus Remagen.
    Wilhein, Thomas
    University of Applied Sciences Koblenz, Rhein Ahr Campus Remagen.
    Single-optical-element soft-x-ray interferometry with a laser-plasma x-ray source2005Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 30, nr 15, s. 2167-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on a compact interferometer for the water-window soft-x-ray range that is suitable for operation with laser-plasma sources. The interferometer consists of a single diffractive optical element that focuses impinging x rays to two focal spots. The light from these two secondary sources forms the interference pattern. The interferometer was operated with a liquid-nitrogen jet laser-plasma source at lambda = 2.88 nm. Scalar wave-field propagation was used to simulate the interference pattern, showing good correspondence between theoretical and experimental results. The diffractive optical element can simultaneously be used as an imaging optic, and we demonstrate soft-x-ray microscopy with interferometric contrast enhancement of a phase object.

  • 329.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Parfeniukas, Karolis
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Stankevic, Tomas
    Kalbfleisch, Sebastian
    Liebi, Marianne
    Matej, Zdenek
    Björling, Alexander
    Carbone, Gerardina
    Mikkelsen, Anders
    Johansson, Ulf
    First x-ray nanoimaging experiments at NanoMAX2017Ingår i: X-Ray Nanoimaging: Instruments and Methods III 2017 / [ed] Lai, B Somogyi, A, SPIE - International Society for Optical Engineering, 2017, Vol. 10389, artikel-id 103890KKonferensbidrag (Refereegranskat)
    Abstract [en]

    NanoMAX is a hard x-ray nanoimaging beamline at the new Swedish synchrotron radiation source MAX IV that became operational in 2016. Being a beamline dedicated to x-ray nanoimaging in both 2D and 3D, NanoMAX is the first to take full advantage of MAX IVs exceptional low emittance and resulting coherent properties. We present results from the first experiments at NanoMAX that took place in December 2016. These did not use the final experimental stations that will become available to users, but a temporary arrangement including zone plate and order-sorting aperture stages and a piezo-driven sample scanner. We used zone plates with outermost zone widths of 100 nm and 30 nm and performed experiments at 8 keV photon energy for x-ray absorption and fluorescence imaging and ptychography. Moreover, we investigated stability and coherence with a Ronchi test method. Despite the rather simple setup, we could demonstrate spatial resolution below 50 nm after only a few hours of beamtime. The results showed that the beamline is working as expected and experiments approaching the 10 nm resolution level or below should be possible in the future.

  • 330.
    Vogt, Ulrich
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Uhlén, Fredrik
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Diffractive optics for laboratory sources to free electron lasers2013Ingår i: 11th International Conference On X-Ray Microscopy (XRM2012), Institute of Physics (IOP), 2013, Vol. 463, nr 1, s. 012001-Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this contribution we present our recent results in the field of diffractive optics for both soft and hard x-ray radiation, and for laboratory sources to x-ray free electron lasers (XFEL). We developed a laboratory soft x-ray microscope that uses in-house produced zone plate optics as high-resolution objectives. We continuously try to improve these optics, both in terms of efficiency and resolution. Our latest development is the manufacturing of tungsten soft x-ray zone plates with outermost zone widths of 12 nm and 90 nm high structures. For hard x-rays, we investigated the possibility to use metal zone plates on a diamond substrate for nano-focusing of the European X-ray Free Electron Laser. The simulations show that the heat conduction is efficient enough to keep a zone plate well below melting temperature. However, metal zone plates will experience large and rapid temperature fluctuations of several hundred Kelvin that might prove fatal. To test this, we manufactured tungsten on diamond prototype zone plates and exposed them to radiation from the LCLS XFEL. Results show that metal zone plates can survive the XFEL beam.

  • 331.
    von Hofsten, Olof
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Phase-Contrast and High-Resolution Optics for X-Ray Microscopy2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    X-ray microscopy is a well-established technique for nanoscale imaging. Zone plates are used as microscope objectives and provide high resolution, approaching 10 nm, currently limited by fabrication issues. This Thesis presents zone plate optics that achieve either high resolution or phase contrast in x-ray microscopy. The high-resolution optics use high orders of the zone plate, which alleviates the demands on fabrication, and the phase-contrast optics are single-element diffractive optical elements that produce contrast by Zernike or differential-interference contrast methods. The advantage of phase contrast in x-ray microscopy is shorter exposure times, and is crucial in the hard x-ray regime. Microscopy in the absorption‑contrast region of the water-window (2.34 - 4.37 nm) also benefits from these optics. The development of the optics for a laboratory soft x-ray microscope spans from theoretical and numerical analysis of coherence and stray light to experimental implementation and testing. The laboratory microscope uses laser-produced plasma-sources in the water-window and is unique in its design and performance. It will be shown that the laboratory microscope in its current form is a user-oriented and stable instrument, and has been used in a number of applications. The implementation of a cryogenic sample stage for tomographic imaging of biological samples in their natural environment has enabled applications in biology, and 3D x-ray microscopy of cells was performed for the first time with a laboratory instrument.

     

    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 332.
    von Hofsten, Olof
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, M.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Experimentell biomolekylär fysik.
    Compact Zernike phase contrast x-ray microscopy using a single-element optic2008Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 33, nr 9, s. 932-934Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate Zernike phase contrast in a compact soft x-ray microscope using a single-element optic. The optic is a combined imaging zone plate and a Zernike phase plate and does not require any additional alignment or components. Contrast is increased and inversed in an image of a test object using the Zernike zone plate. This type of optic may be implemented into any existing x-ray microscope where phase contrast is of interest.

  • 333.
    von Hofsten, Olof
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Reinspach, Julia
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Experimentell biomolekylär fysik.
    Sub-25-nm laboratory x-ray microscopy using a compound Fresnel zone plate2009Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 34, nr 17, s. 2631-2633Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Improving the resolution in x-ray microscopes is of high priority to enable future applications in nanoscience. However, high-resolution zone-plate optics often have low efficiency, which makes implementation in laboratory microscopes difficult. We present a laboratory x-ray microscope based on a compound zone plate. The compound zone plate utilizes multiple diffraction orders to achieve high resolution while maintaining reasonable efficiency. We analyze the illumination conditions necessary for this type of optics in order to suppress stray light and demonstrate microscopic imaging resolving 25 nm features.

  • 334.
    von Hofsten, Olof
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Experimentell biomolekylär fysik.
    Theoretical development of a high-resolution differential-interference-contrast optic for x-ray microscopy2008Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 16, nr 2, s. 1132-1141Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, the theoretical background and development of a differential-interference contrast (DIC) x-ray optic is presented. The single-element optic is capable of high-resolution phase contrast imaging and is compatible with compact sources. It is shown that an understanding of the coherence requirements in this type of imaging is imperative and is explained in detail. The optic is capable of a wavefront separation equal to the resolution of the optic which places only minor constraints on the object illumination.

  • 335.
    von Hofsten, Olov
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Lindblom, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Compact phase-contrast soft X-ray microscopy2009Ingår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 186Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    For nearly all elements, the real part, delta, of the complex index of refraction n (n = 1 - delta + i beta) is larger than the imaginary part, beta, in the x-ray region. Since only beta is used in absorption contrast, phase-contrast imaging techniques which give access to delta are very important. In this paper we present two different implementations of phase contrast in our compact soft x-ray microscope, differential-interference contrast and Zemike phase contrast.

  • 336.
    von Hofsten, Olov
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bertilson, Michael
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Simulation of partially coherent image formation in x-ray microscopy - art. no. 67050I2007Ingår i: Advances in X-Ray/EUV Optics and Components II, SPIE - International Society for Optical Engineering, 2007, Vol. 6705, s. I7050-I7050Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present the theory and implementation of a numerical model capable of simulating two-dimensional images for an x-ray microscope using partially coherent illumination considerations. Partially coherent illumination is found in all x-ray microscopes and particularly in the latest generation of our in-house compact soft x-ray microscope. This is due to an introduced mismatch in numerical aperture of the condenser and objective zone plate, and will yield diffraction-like artifacts in phase-shifting objects. The numerical model approximates the condenser zone plate as a secondary incoherent source represented by individually coherent but mutually incoherent source emitters, each giving rise to a separate image. A final image is obtained by adding up the image intensities of the individual contributions. The simulation has been a useful tool for investigating the influence of coherence on images in both the mirror and zone plate condenser arrangement of the in-house compact soft x-ray microscope. The latest development included in the program is the effect of astigmatism and partial coherence, where the calculated results show good qualitative agreement with respect to the microscope images.

  • 337.
    von Hofsten, Olov
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Takman, Per
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Voght, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Simulation of partially coherent image formation in a compact soft x-ray microscope2007Ingår i: Ultramicroscopy, ISSN 0304-3991, E-ISSN 1879-2723, Vol. 107, nr 8, s. 604-609Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we describe a numerical method of simulating two-dimensional images in a compact soft X-ray microscope using partially coherent illumination considerations. The work was motivated by recent test object images obtained by the latest generation inhouse compact soft X-ray microscope, which showed diffraction-like artifacts not observed previously. The numerical model approximates the condenser zone plate as a secondary incoherent source represented by individually coherent but mutually incoherent source points, each giving rise to a separate image. A final image is obtained by adding up all the individual source point contributions. The results are compared with the microscope images and show qualitative agreement, indicating that the observed effects are caused by partially coherent illumination.

  • 338.
    Vågberg, William
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Larsson, D. H.
    Li, M.
    Arner, A.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    X-ray phase-contrast tomography for high-spatial-resolution zebrafish muscle imaging2015Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Imaging of muscular structure with cellular or subcellular detail in whole-body animal models is of key importance for understanding muscular disease and assessing interventions. Classical histological methods for high-resolution imaging methods require excision, fixation and staining. Here we show that the three-dimensional muscular structure of unstained whole zebrafish can be imaged with sub-5μm detail with X-ray phase-contrast tomography. Our method relies on a laboratory propagation-based phase-contrast system tailored for detection of low-contrast 4-6μm subcellular myofibrils. The method is demonstrated on 20 days post fertilization zebrafish larvae and comparative histology confirms that we resolve individual myofibrils in the whole-body animal. X-ray imaging of healthy zebrafish show the expected structured muscle pattern while specimen with a dystrophin deficiency (sapje) displays an unstructured pattern, typical of Duchenne muscular dystrophy. The method opens up for whole-body imaging with sub-cellular detail also of other types of soft tissue and in different animal models.

  • 339.
    Vågberg, WIlliam
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Larsson, Daniel H.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Li, Mei
    Arner, Anders
    Hertz, Hans M.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Laboratory phase-contrast x-ray tomography for imaging of zebrafish muscle structureManuskript (preprint) (Övrigt vetenskapligt)
  • 340.
    Vågberg, William
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Larsson, Jakob C.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Hertz, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Removal of ring artifacts in microtomography by characterization of scintillator variations2017Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 25, nr 19, s. 23191-23198Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ring artifacts reduce image quality in tomography, and arise from faulty detector calibration. In microtomography, we have identified that ring artifacts can arise due to highspatial frequency variations in the scintillator thickness. Such variations are normally removed by a flat-field correction. However, as the spectrum changes, e. g. due to beam hardening, the detector response varies non-uniformly introducing ring artifacts that persist after flat-field correction. In this paper, we present a method to correct for ring artifacts from variations in scintillator thickness by using a simple method to characterize the local scintillator response. The method addresses the actual physical cause of the ring artifacts, in contrary to many other ring artifact removal methods which rely only on image post-processing. By applying the technique to an experimental phantom tomography, we show that ring artifacts are strongly reduced compared to only making a flat-field correction.

  • 341. Wagner, U. H.
    et al.
    Parsons, A.
    Rahomäki, Jussi
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Vogt, Ulrich
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Rau, C.
    Characterising the Large Coherence Length at Diamond's Beamline I13L2016Ingår i: Proceedings of The 12th International Conference on Synchrotron Radiation Instrumentation (SRI2015), American Institute of Physics (AIP), 2016, artikel-id 050022Konferensbidrag (Refereegranskat)
    Abstract [en]

    I13 is a 250 m long hard x-ray beamline (6 keV to 35 keV) at the Diamond Light Source. The beamline comprises of two independent experimental endstations: one for imaging in direct space using x-ray microscopy and one for imaging in reciprocal space using coherent diffraction based imaging techniques [1]. An outstanding feature of the coherence branch, due to its length and a new generation of ultra-stable beamline instrumentation [2], is its capability of delivering a very large coherence length well beyond 200 m, providing opportunities for unique x-ray optical experiments. In this paper we discuss the challenges of measuring a large coherence length and present quantitative measurement based on analyzing diffraction patterns from a boron fiber [3]. We also discuss the limitations of this classical method in respect to detector performance, very short and long coherence lengths. Furthermore we demonstrate how a Ronchi grating setup [4] can be used to quickly establish if the beam is coherent over a large area.

  • 342. Wahlberg, M.
    et al.
    Pettersson, A. Lindskoog
    Rosén, Robert
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Nilsson, M.
    Unsbo, Peter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Brautaset, R.
    Clinical importance of spherical and chromatic aberration on the accommodative response in contact lens wear2011Ingår i: Journal of Modern Optics, ISSN 0950-0340, E-ISSN 1362-3044, Vol. 58, nr 19-20, s. 1696-1702Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate the accommodation response under both mono-and polychromatic light while varying the amount of spherical aberration. It is thought that chromatic and spherical aberrations are directional cues for the accommodative system and could affect response time, velocity or lag. Spherical aberration is often eliminated in modern contact lenses in order to enhance image quality in the unaccommodated eye. This study was divided into two parts. The first part was done to evaluate the amount of spherical and other Zernike aberrations in the unaccommodated eye when uncorrected and with two types of correction (trial lens and spherical-aberration controlled contact lens) and the second part evaluated the dynamic accommodation responses obtained when wearing each of the corrections under polychromatic and monochromatic conditions. Measurements of accommodation showed no significant differences in time, velocity and lag of accommodation after decreasing the spherical aberration with a contact lens, neither in monochromatic nor polychromatic light. It is unlikely that small to normal changes of spherical aberration in white light or monochromatic mid-spectral light affect directional cues for the accommodative system, not in white light or mid-spectral monochromatic light, since the accommodative response did not show any change.

  • 343.
    Wang, Damao
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Li, Jing
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Salazar-Alvarez, Germán
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Stockholm University.
    McKee, Lauren S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Srivastava, Vaibhav
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Sellberg, Jonas A.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Bulone, Vincent
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Hsieh, Yves S. Y.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Production of functionalised chitins assisted by fungal lytic polysaccharide monooxygenase2018Ingår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 20, nr 9, s. 2091-2100Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The gene CCT67099 from Fusarium fujikuroi was shown to encode a novel enzyme from the Lytic Polysaccharide Monooxygenase (LPMO) Family AA11. The gene was expressed and a truncated version of the enzyme, designated as FfAA11, was purified from the periplasmic space of Escherichia coli cells at high yield. FfAA11 exhibited oxidative activity against α- and β-chitins, as well as lobster shells. Under optimised conditions, FfAA11 introduced 35 nmol of carboxylate (COO) moieties per milligram of α-chitin. These carboxylate groups were introduced onto the chitin surface under mild enzymatic oxidation conditions in an aqueous solution without changes to the crystallinity of the chitin fibres. FfAA11 was also combined with a simple and environmentally friendly chemical method that transforms recalcitrant chitins into desirable functionalised (nano)materials. The use of ethyl(hydroxyimino)cyanoacetate (Oxyma)-assisted click chemistry allowed the rapid modification of the surface of FfAA11-oxidized chitins, with a fluorescent probe, a peptide, and gold nanoparticles. The chemical steps performed, including the FfAA11 oxidase treatment and surface chemical modification, were achieved without the production of any toxic by-products or waste organic solvents. This approach represents a novel method for the greener production of chitin-based biomaterials.

  • 344. Welch, C. C.
    et al.
    Olynick, D. L.
    Liu, Z.
    Holmberg, Anders
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Peroz, C.
    Robinson, A. P. G.
    Henry, M. D.
    Scherer, A.
    Mollenhauer, T.
    Genova, V.
    Ng, D. K. T.
    Formation of nanoscale structures by inductively coupled plasma etching2012Ingår i: International Conference Micro- and Nano-Electronics 2012, SPIE - International Society for Optical Engineering, 2012, s. 870002-Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper will review the top down technique of ICP etching for the formation of nanometer scale structures. The increased difficulties of nanoscale etching will be described. However it will be shown and discussed that inductively coupled plasma (ICP) technology is well able to cope with the higher end of the nanoscale: features from 100nm down to about 40nm are relatively easy with current ICP technology. It is the ability of ICP to operate at low pressure yet with high plasma density and low (controllable) DC bias that helps greatly compared to simple reactive ion etching (RIE) and, though continual feature size reduction is increasingly challenging, improvements to ICP technology as well as improvements in masking are enabling sub-10nm features to be reached. Nanoscale ICP etching results will be illustrated in a range of materials and technologies. Techniques to facilitate etching (such as the use of cryogenic temperatures) and techniques to improve the mask performance will be described and illustrated.

  • 345.
    Wiedorn, Max O.
    et al.
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Oberthuer, Dominik
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Bean, Richard
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Schubert, Robin
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany.;Integrated Biol Infrastruct Life Sci Facil Europe, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Werner, Nadine
    Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany..
    Abbey, Brian
    La Trobe Univ, Ctr Excellence Adv Mol Imaging, La Trobe Inst Mol Sci, Dept Chem & Phys,ARC, Bundoora, Vic 3086, Australia..
    Aepfelbacher, Martin
    Univ Med Ctr Hamburg Eppendorf UKE, Inst Med Microbiol Virol & Hyg, D-20246 Hamburg, Germany..
    Adriano, Luigi
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Allahgholi, Aschkan
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Al-Qudami, Nasser
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Andreasson, Jakob
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden.;Czech Acad Sci, ELI Beamlines, Inst Phys, Na Slovance 2, Prague 18221, Czech Republic.;Chalmers Univ Technol, Dept Phys, Condensed Matter Phys, S-41296 Gothenburg, Sweden..
    Aplin, Steve
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Awel, Salah
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Ayyer, Kartik
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Bajt, Sasa
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Barak, Imrich
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Bari, Sadia
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Bielecki, Johan
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Botha, Sabine
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany..
    Boukhelef, Djelloul
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Brehm, Wolfgang
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Brockhauser, Sandor
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany.;Hungarian Acad Sci, BRC, Temesvari Krt 62, H-6726 Szeged, Hungary..
    Cheviakov, Igor
    Univ Med Ctr Hamburg Eppendorf UKE, Inst Med Microbiol Virol & Hyg, D-20246 Hamburg, Germany..
    Coleman, Matthew A.
    Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA..
    Cruz-Mazo, Francisco
    Univ Seville, Dept Ingn Aeroesp & Mecan Fluidos ETSI, Seville 41092, Spain..
    Danilevski, Cyril
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Darmanin, Connie
    La Trobe Univ, Ctr Excellence Adv Mol Imaging, La Trobe Inst Mol Sci, Dept Chem & Phys,ARC, Bundoora, Vic 3086, Australia..
    Doak, R. Bruce
    Max Planck Inst Med Res, Jahnstr 29, D-69120 Heidelberg, Germany..
    Domaracky, Martin
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Doerner, Katerina
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Du, Yang
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Fangohr, Hans
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany.;Univ Southampton, Engn & Environm, Southampton SO17 1BJ, Hants, England..
    Fleckenstein, Holger
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Frank, Matthias
    Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA..
    Fromme, Petra
    Arizona State Univ, Sch Mol Sci & Biodesign, Ctr Appl Struct Discovery, Tempe, AZ 85287 USA..
    Ganan-Calvo, Alfonso M.
    Univ Seville, Dept Ingn Aeroesp & Mecan Fluidos ETSI, Seville 41092, Spain..
    Gevorkov, Yaroslav
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Hamburg Univ Technol, Vis Syst E2, Harburger Schlostr 20, D-21079 Hamburg, Germany..
    Giewekemeyer, Klaus
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Ginn, Helen Mary
    Div Struct Biol, Oxford OX3 7BN, England.;Diamond Light Source, Res Complex Harwell, Diamond House,Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England.;Univ Oxford, Diamond House,Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Graafsma, Heinz
    DESY, Notkestr 85, D-22607 Hamburg, Germany.;Mid Sweden Univ, Holmgatan 10, S-85170 Sundsvall, Sweden..
    Graceffa, Rita
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Greiffenberg, Dominic
    Paul Scherrer Inst, Forsch Str 111, CH-5232 Villigen, Switzerland..
    Gumprecht, Lars
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Goettlicher, Peter
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Hajdu, Janos
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden.;Czech Acad Sci, ELI Beamlines, Inst Phys, Na Slovance 2, Prague 18221, Czech Republic..
    Hauf, Steffen
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Heymann, Michael
    Max Planck Inst Biochem, Dept Cellular & Mol Biophys, D-82152 Martinsried, Germany..
    Holmes, Susannah
    La Trobe Univ, Ctr Excellence Adv Mol Imaging, La Trobe Inst Mol Sci, Dept Chem & Phys,ARC, Bundoora, Vic 3086, Australia..
    Horke, Daniel A.
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Hunter, Mark S.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Imlau, Siegfried
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Kaukher, Alexander
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Kim, Yoonhee
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Klyuev, Alexander
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Knoska, Juraj
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Kobe, Bostjan
    Univ Queensland, Inst Mol Biosci, Sch Chem & Mol Biosci, Brisbane, Qld 4072, Australia.;Univ Queensland, Australian Infect Dis Res Ctr, Brisbane, Qld 4072, Australia..
    Kuhn, Manuela
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Kupitz, Christopher
    Univ Wisconsin, Phys Dept, 3135 N Maryland Ave, Milwaukee, WI 53211 USA..
    Kueper, Jochen
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Dept Chem, Martin Luther King Pl 6, D-20146 Hamburg, Germany..
    Lahey-Rudolph, Janine Mia
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Lubeck, Inst Biochem, Ctr Struct & Cell Biol Med, Ratzeburger Allee 160, D-23562 Lubeck, Germany..
    Laurus, Torsten
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Le Cong, Karoline
    Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany..
    Letrun, Romain
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Xavier, P. Lourdu
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Max Planck Inst Struct & Dynam Matter, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Maia, Luis
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Maia, Filipe R. N. C.
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden.;Lawrence Berkeley Natl Lab, NERSC, Berkeley, CA 94720 USA..
    Mariani, Valerio
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Messerschmidt, Marc
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Metz, Markus
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Mezza, Davide
    Paul Scherrer Inst, Forsch Str 111, CH-5232 Villigen, Switzerland..
    Michelat, Thomas
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Mills, Grant
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Monteiro, Diana C. F.
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Morgan, Andrew
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Muhlig, Kerstin
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden..
    Munke, Anna
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden..
    Muennich, Astrid
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Nette, Julia
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Nugent, Keith A.
    La Trobe Univ, Ctr Excellence Adv Mol Imaging, La Trobe Inst Mol Sci, Dept Chem & Phys,ARC, Bundoora, Vic 3086, Australia..
    Nuguid, Theresa
    Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany..
    Orville, Allen M.
    Diamond Light Source, Res Complex Harwell, Diamond House,Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England.;Univ Oxford, Diamond House,Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Pandey, Suraj
    Univ Wisconsin, Phys Dept, 3135 N Maryland Ave, Milwaukee, WI 53211 USA..
    Pena, Gisel
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Villanueva-Perez, Pablo
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Poehlsen, Jennifer
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Previtali, Gianpietro
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Redecke, Lars
    Univ Med Ctr Hamburg Eppendorf UKE, Inst Med Microbiol Virol & Hyg, D-20246 Hamburg, Germany.;Univ Lubeck, Inst Biochem, Ctr Struct & Cell Biol Med, Ratzeburger Allee 160, D-23562 Lubeck, Germany..
    Riekehr, Winnie Maria
    Univ Lubeck, Inst Biochem, Ctr Struct & Cell Biol Med, Ratzeburger Allee 160, D-23562 Lubeck, Germany..
    Rohde, Holger
    Univ Med Ctr Hamburg Eppendorf UKE, Inst Med Microbiol Virol & Hyg, D-20246 Hamburg, Germany..
    Round, Adam
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Safenreiter, Tatiana
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Sarrou, Iosifina
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Sato, Tokushi
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Schmidt, Marius
    Univ Wisconsin, Phys Dept, 3135 N Maryland Ave, Milwaukee, WI 53211 USA..
    Schmitt, Bernd
    Paul Scherrer Inst, Forsch Str 111, CH-5232 Villigen, Switzerland..
    Schoenherr, Robert
    Univ Lubeck, Inst Biochem, Ctr Struct & Cell Biol Med, Ratzeburger Allee 160, D-23562 Lubeck, Germany..
    Schulz, Joachim
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Sellberg, Jonas A.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Seibert, M. Marvin
    Uppsala Univ, Dept Cell & Mol Biol, Lab Mol Biophys, S-75124 Uppsala, Sweden..
    Seuring, Carolin
    SAS, Inst Mol Biol, Dubravska Cesta 21, Bratislava 84551, Slovakia..
    Shelby, Megan L.
    Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA..
    Shoeman, Robert L.
    Max Planck Inst Med Res, Jahnstr 29, D-69120 Heidelberg, Germany..
    Sikorski, Marcin
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Silenzi, Alessandro
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Stan, Claudiu A.
    Rutgers Univ Newark, Phys Dept, Newark, NJ 07102 USA..
    Shi, Xintian
    Paul Scherrer Inst, Forsch Str 111, CH-5232 Villigen, Switzerland..
    Stern, Stephan
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Sztuk-Dambietz, Jola
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Szuba, Janusz
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Tolstikova, Aleksandra
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Trebbin, Martin
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Buffalo, Dept Chem, 359 Nat Sci Complex, Buffalo, NY 14260 USA.;Univ Hamburg, Inst Nanostruct & Solid State Phys, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Trunk, Ulrich
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Vagovic, Patrik
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Ve, Thomas
    Griffith Univ, Inst Glyc, Southport, Qld 4222, Australia..
    Weinhausen, Britta
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    White, Thomas A.
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Wrona, Krzysztof
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Xu, Chen
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Yefanov, Oleksandr
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Zatsepin, Nadia
    Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA..
    Zhang, Jiaguo
    Paul Scherrer Inst, Forsch Str 111, CH-5232 Villigen, Switzerland..
    Perbandt, Markus
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany.;Univ Med Ctr Hamburg Eppendorf UKE, Inst Med Microbiol Virol & Hyg, D-20246 Hamburg, Germany..
    Mancuso, Adrian P.
    European XFEL GmbH, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Betzel, Christian
    Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Inst Biochem & Mol Biol, Lab Struct Biol Infect & Inflammat, Notkestr 85, D-22607 Hamburg, Germany.;Integrated Biol Infrastruct Life Sci Facil Europe, Holzkoppel 4, D-22869 Schenefeld, Germany..
    Chapman, Henry
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany.;Univ Hamburg, Dept Phys, Luruper Chaussee 149, D-22761 Hamburg, Germany.;Univ Hamburg, Hamburg Ctr Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany..
    Barty, Anton
    DESY, Ctr Free Electron Laser Sci, Notkestr 85, D-22607 Hamburg, Germany..
    Megahertz serial crystallography2018Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, artikel-id 4025Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The new European X-ray Free-Electron Laser is the first X-ray free-electron laser capable of delivering X-ray pulses with a megahertz inter-pulse spacing, more than four orders of magnitude higher than previously possible. However, to date, it has been unclear whether it would indeed be possible to measure high-quality diffraction data at megahertz pulse repetition rates. Here, we show that high-quality structures can indeed be obtained using currently available operating conditions at the European XFEL. We present two complete data sets, one from the well-known model system lysozyme and the other from a so far unknown complex of a beta-lactamase from K. pneumoniae involved in antibiotic resistance. This result opens up megahertz serial femtosecond crystallography (SFX) as a tool for reliable structure determination, substrate screening and the efficient measurement of the evolution and dynamics of molecular structures using megahertz repetition rate pulses available at this new class of X-ray laser source.

  • 346.
    Wiklund, Martin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Acoustofluidics 12: Biocompatibility and cell viability in microfluidic acoustic resonators2012Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, nr 11, s. 2018-2028Artikel i tidskrift (Övrigt vetenskapligt)
  • 347.
    Wiklund, Martin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Affinity-Bead-Mediated Acoustophoresis: A Novel Tool in Cytometry2014Ingår i: Cytometry Part A, ISSN 1552-4922, E-ISSN 1552-4930, Vol. 85A, nr 11, s. 915-917Artikel i tidskrift (Refereegranskat)
  • 348.
    Wiklund, Martin
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Brismar, Hjalmar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Önfelt, Björn
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Acoustofluidics 18: Microscopy for acoustofluidic micro-devices2012Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 12, nr 18, s. 3221-3234Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    In this tutorial review in the thematic series "Acoustofluidics", we discuss the implementation and practice of optical microscopy in acoustofluidic micro-devices. Examples are given from imaging of acoustophoretic manipulation of particles and cells in microfluidic channels, but most of the discussion is applicable to imaging in any lab-on-a-chip device. The discussion includes basic principles of optical microscopy, different microscopy modes and applications, and design criteria for micro-devices compatible with basic, as well as advanced, optical microscopy.

  • 349.
    Wiklund, Martin
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia E.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Iranmanesh, Ida
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ohlin, Mathias
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Russom, Aman
    KTH, Skolan för bioteknologi (BIO), Proteomik och nanobioteknologi.
    Önfelt, Björn
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    On-chip acoustic sample preparation for cell studies and diagnostics2013Ingår i: Proceedings of Meetings on Acoustics: Volume 19, 2013, Acoustical Society of America (ASA), 2013, s. 1-3Konferensbidrag (Refereegranskat)
    Abstract [en]

    We describe a novel platform for acoustic sample preparation in microchannels and microplates. The utilized method is based on generating a multitude of acoustic resonances at a set of different frequencies in microstructures, in order to accurately control the migration and positioning of particles and cells suspended in fluid channels and chambers. The actuation frequencies range from 30 kHz to 7 MHz, which are applied simultaneously and/or in sweeps. We present two devices: A closed microfluidic chip designed for pre-alignment, size-based separation, isolation, up-concentration and lysis of cells, and an open multi-well microplate designed for parallel aggregation and positioning of cells. Both devices in the platform are compatible with high-resolution live-cell microscopy, which is used for fluorescence-based optical characterization. Two bioapplications are demonstrated for each of the devices: The first device is used for size-selective cell isolation and lysis for DNA-based diagnostics, and the second device is used for quantifying the heterogeneity in cytotoxic response of natural killer cells interacting with cancer cells.

  • 350.
    Wiklund, Martin
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Christakou, Athanasia E.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Ohlin, Mathias
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Iranmanesh, Ida
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
    Frisk, Thomas
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Vanherberghen, Bruno
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Önfelt, Björn
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik.
    Ultrasound-Induced Cell-Cell Interaction Studies in a Multi-Well Microplate2014Ingår i: Micromachines, ISSN 2072-666X, E-ISSN 2072-666X, Vol. 5, nr 1, s. 27-49Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    This review describes the use of ultrasound for inducing and retaining cell-cell contact in multi-well microplates combined with live-cell fluorescence microscopy. This platform has been used for studying the interaction between natural killer (NK) cells and cancer cells at the level of individual cells. The review includes basic principles of ultrasonic particle manipulation, design criteria when building a multi-well microplate device for this purpose, biocompatibility aspects, and finally, two examples of biological applications: Dynamic imaging of the inhibitory immune synapse, and studies of the heterogeneity in killing dynamics of NK cells interacting with cancer cells.

45678 301 - 350 av 376
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf