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1.
J Synchrotron Radiat ; 31(Pt 2): 363-377, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38386565

RESUMO

The ForMAX beamline at the MAX IV Laboratory provides multiscale and multimodal structural characterization of hierarchical materials in the nanometre to millimetre range by combining small- and wide-angle X-ray scattering with full-field microtomography. The modular design of the beamline is optimized for easy switching between different experimental modalities. The beamline has a special focus on the development of novel fibrous materials from forest resources, but it is also well suited for studies within, for example, food science and biomedical research.

2.
Phys Rev Lett ; 123(2): 023201, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386513

RESUMO

We present a comprehensive experimental and theoretical study on superfluorescence in the extreme ultraviolet wavelength regime. Focusing a free-electron laser pulse in a cell filled with Xe gas, the medium is quasi-instantaneously population inverted by 4d-shell ionization on the giant resonance followed by Auger decay. On the timescale of ∼10 ps to ∼100 ps (depending on parameters) a macroscopic polarization builds up in the medium, resulting in superfluorescent emission of several Xe lines in the forward direction. As the number of emitters in the system is increased by either raising the pressure or the pump-pulse energy, the emission yield grows exponentially over four orders of magnitude and reaches saturation. With increasing yield, we observe line broadening, a manifestation of superfluorescence in the spectral domain. Our novel theoretical approach, based on a full quantum treatment of the atomic system and the irradiated field, shows quantitative agreement with the experiment and supports our interpretation.

4.
Phys Rev Lett ; 117(15): 153003, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27768351

RESUMO

Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0.3 Å. This high fidelity is due to interference between the nonstationary excitation and the stationary initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space movies of atomic motion on ångstrom and femtosecond scales. This x-ray interference has not been employed to image internal motion in molecules before. Coherent vibrational motion and dispersion, dissociation, and rotational dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods.

5.
Orv Hetil ; 139(18): 1091-3, 1998 May 03.
Artigo em Húngaro | MEDLINE | ID: mdl-9608773

RESUMO

The authors review a case of a patient with spontaneous cervical hematoma without trauma. The similar cases of the international literature, the causes (local and systemic vascular disorders, inflammatory and neoplastic disease of the surrounding tissues) are summarized and the importance of the computerized tomography in connection with the described case is emphasized.


Assuntos
Hematoma/complicações , Insuficiência Respiratória/etiologia , Idoso , Feminino , Hematoma/diagnóstico por imagem , Hematoma/cirurgia , Humanos , Pescoço/irrigação sanguínea , Pescoço/diagnóstico por imagem , Pescoço/cirurgia , Ruptura Espontânea/diagnóstico por imagem , Ruptura Espontânea/cirurgia , Tomografia Computadorizada por Raios X
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