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Institution

Humboldt University of Berlin

EducationBerlin, Germany
About: Humboldt University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Transplantation. The organization has 33671 authors who have published 61781 publications receiving 1908102 citations. The organization is also known as: Humboldt-Universität zu Berlin & Universitas Humboldtiana Berolinensis.


Papers
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OtherDOI
TL;DR: Two TJ protein families can be distinguished, claudins, comprising 27 members in mammals, and TJ-associated MARVEL proteins (TAMP), comprising occludin, tricellulin, and MarvelD3, which are linked to a multitude of TJ- associated regulatory and scaffolding proteins.
Abstract: Epithelial transport relies on the proper function and regulation of the tight junction (TJ), other-wise uncontrolled paracellular leakage of solutes and water would occur. They also act as a fence against mixing of membrane proteins of the apical and basolateral side. The proteins determining paracellular transport consist of four transmembrane regions, intracellular N and C terminals, one intracellular and two extracellular loops (ECLs). The ECLs interact laterally and with counterparts of the neighboring cell and by this achieve a general sealing function. Two TJ protein families can be distinguished, claudins, comprising 27 members in mammals, and TJ-associated MARVEL proteins (TAMP), comprising occludin, tricellulin, and MarvelD3. They are linked to a multitude of TJ-associated regulatory and scaffolding proteins. The major TJ proteins are classified according to the physiological role they play in enabling or preventing paracellular transport. Many TJ proteins have sealing functions (claudins 1, 3, 5, 11, 14, 19, and tricellulin). In contrast, a significant number of claudins form channels across TJs which feature selectivity for cations (claudins 2, 10b, and 15), anions (claudin-10a and -17), or are permeable to water (claudin-2). For several TJ proteins, function is yet unclear as their effects on epithelial barriers are inconsistent (claudins 4, 7, 8, 16, and occludin). TJs undergo physiological and pathophysiological regulation by altering protein composition or abundance. Major pathophysiological conditions which involve changes in TJ protein composition are (1) effects of pathogens binding to TJ proteins, (2) altered TJ protein composition during inflammation and infection, and (3) altered TJ protein expression in cancers.

295 citations

Journal ArticleDOI
TL;DR: In this article, the luminescence energy transfer between small noble metal particles and lanthanide(III) ions was studied, and it was shown that the observed enhancement is due to a classical energy transfer, and not to a plasmonic field enhancement effect.
Abstract: With the technique of synchrotron X-ray activation, molecule-like, non-plasmonic gold and silver particles in soda-lime silicate glasses can be generated. The luminescence energy transfer between these species and Ianthanide(III) ions is studied. As a result, a significant lanthanide luminescence enhancement by a factor of up to 250 under non-resonant UV excitation is observed. The absence of a distinct gold and silver plasmon resonance absorption, respectively, the missing nanoparticle signals in previous SAXS and TEM experiments, the unaltered luminescence lifetime of the lanthanide ions compared to the non-enhanced case, and an excitation maximum at 300―350 nm (equivalent to the absorption range of small noble metal particles) indicate unambiguously that the observed enhancement is due to a classical energy transfer between small noble metal particles and lanthanide ions, and not to a plasmonic field enhancement effect. It is proposed that very small, molecule-like noble metal particles (such as dimers, trimers, and tetramers) first absorb the excitation light, undergo a singlet-triplet intersystem crossing, and finally transfer the energy to an excited multiplet state of adjacent lanthanide(III) ions. X-ray lithographic microstructuring and excitation with a commercial UV LED show the potential of the activated glass samples as bright light-emitting devices with tunable emission colors.

295 citations

Journal ArticleDOI
A. Abramowski, Fabio Acero, Felix Aharonian1, Felix Aharonian2  +205 moreInstitutions (21)
TL;DR: In this paper, the authors obtained upper limits on line-like emission in the energy range between ~500 GeV and ~25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies.
Abstract: Gamma-ray line signatures can be expected in the very-high-energy (VHE; E_\gamma > 100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical \gamma-ray sources that in most cases produce continuous spectra which span over several orders of magnitude in energy. Using data collected with the H.E.S.S. \gamma-ray instrument, upper limits on line-like emission are obtained in the energy range between ~500 GeV and ~25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic \gamma-ray line emission, flux limits of (2x10^-7 - 2x10^-5) m^-2 s^-1 sr^-1 and (1x10^-8 - 2x10^-6) m^-2 s^-1 sr^-1 are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section (\chi\chi -> \gamma\gamma) reach ~10^-27 cm^3 s^-1, based on the Einasto parametrization of the Galactic DM halo density profile.

295 citations

Journal ArticleDOI
TL;DR: Among patients with stable angina and risk factors for coronary artery disease, myocardial-perfusion cardiovascular MRI was associated with a lower incidence of coronary revascularization than FFR and was noninferior to FFR with respect to major adverse cardiac events.
Abstract: Background In patients with stable angina, two strategies are often used to guide revascularization: one involves myocardial-perfusion cardiovascular magnetic resonance imaging (MRI), and ...

294 citations

Journal ArticleDOI
TL;DR: In a phase 3 trial of patients with Crohn's disease and treatment-refractory complex perianal fistulas, Cx601 is found to be safe and effective in closing external openings, compared with placebo, after 1 year.

294 citations


Authors

Showing all 34115 results

NameH-indexPapersCitations
Karl J. Friston2171267217169
Peer Bork206697245427
Raymond J. Dolan196919138540
Stefan Schreiber1781233138528
Andreas Pfeiffer1491756131080
Thomas Hebbeker1481984114004
Thomas Lohse1481237101631
Jean Bousquet145128896769
Hermann Kolanoski145127996152
Josh Moss139101989255
R. D. Kass1381920107907
W. Kozanecki138149899758
U. Mallik137162597439
C. Haber135150798014
Christophe Royon134145390249
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023208
2022747
20214,727
20204,083
20193,579
20183,143