Institution
Humboldt University of Berlin
Education•Berlin, 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 published on a yearly basis
Papers
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TL;DR: Enthalpy barriers can be calculated with near chemical accuracy, which constitutes significant progress in the quantum chemical modeling of reactions in heterogeneous catalysis in general and microporous zeolites in particular.
Abstract: The methylation of ethene, propene, and t-2-butene by methanol over the acidic microporous H-ZSM-5 catalyst has been investigated by a range of computational methods. Density functional theory (DFT) with periodic boundary conditions (PBE functional) fails to describe the experimentally determined decrease of apparent energy barriers with the alkene size due to inadequate description of dispersion forces. Adding a damped dispersion term expressed as a parametrized sum over atom pair C6 contributions leads to uniformly underestimated barriers due to self-interaction errors. A hybrid MP2:DFT scheme is presented that combines MP2 energy calculations on a series of cluster models of increasing size with periodic DFT calculations, which allows extrapolation to the periodic MP2 limit. Additionally, errors caused by the use of finite basis sets, contributions of higher order correlation effects, zero-point vibrational energy, and thermal contributions to the enthalpy were evaluated and added to the “periodic” MP2...
283 citations
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TL;DR: The adsorption and reaction energies are compared with the results from Møller‐Plesset second‐order perturbation theory with basis set extrapolation and errors due to missing self‐interaction correction are not affected.
Abstract: Ewald summation is used to apply semiempirical long-range dispersion corrections (Grimme, J Comput Chem 2006, 27, 1787; 2004, 25, 1463) to periodic systems in density functional theory. Using the parameters determined before for molecules and the Perdew-Burke-Ernzerhof functional, structure parameters and binding energies for solid methane, graphite, and vanadium pentoxide are determined in close agreement with observed values. For methane, a lattice constant a of 580 pm and a sublimation energy of 11 kJ mol−1 are calculated. For the layered solids graphite and vanadia, the interlayer distances are 320 pm and 450 pm, respectively, whereas the graphite interlayer energy is −5.5 kJ mol−1 per carbon atom and layer. Only when adding the semiempirical dispersion corrections, realistic values are obtained for the energies of adsorption of C4 alkenes in microporous silica (−66 to −73 kJ mol−1) and the adsorption and chemisorption (alkoxide formation) of isobutene on acidic sites in the micropores of zeolite ferrierite (−78 to −94 kJ mol−1). As expected, errors due to missing self-interaction correction as in the energy for the proton transfer from the acidic site to the alkene forming a carbenium ion are not affected by the dispersion term. The adsorption and reaction energies are compared with the results from Moller-Plesset second-order perturbation theory with basis set extrapolation. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
282 citations
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TL;DR: Whether and how processes related to maternal stress and stress biology may interact with and modify the effects of maternal thyroid function on offspring brain development is considered, with implications for early identification of risk, primary prevention and intervention.
282 citations
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TL;DR: This paper found that women are less confident in their entrepreneurial skills, have different social networks and exhibit higher fear of failure than men, and these variables explain a substantial part of the gender gap in entrepreneurial activity.
Abstract: Using data from representative population surveys in 17 countries, we find that the lower rate of female business ownership is primarily due to women's lower propensity to start businesses rather than to differences in survival rates across genders. We show that women are less confident in their entrepreneurial skills, have different social networks and exhibit higher fear of failure than men. After controlling for endogeneity, we find that these variables explain a substantial part of the gender gap in entrepreneurial activity. Although, of course, their relative importance varies significantly across countries, these factors appear to have a universal effect.
282 citations
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TL;DR: The ability of Vpu to increase virus release from infected cells may be correlated with an ion channel activity of the TM domain, thereby providing a potential target for drug intervention based on the development of VPU‐specific channel blockers.
282 citations
Authors
Showing all 34115 results
Name | H-index | Papers | Citations |
---|---|---|---|
Karl J. Friston | 217 | 1267 | 217169 |
Peer Bork | 206 | 697 | 245427 |
Raymond J. Dolan | 196 | 919 | 138540 |
Stefan Schreiber | 178 | 1233 | 138528 |
Andreas Pfeiffer | 149 | 1756 | 131080 |
Thomas Hebbeker | 148 | 1984 | 114004 |
Thomas Lohse | 148 | 1237 | 101631 |
Jean Bousquet | 145 | 1288 | 96769 |
Hermann Kolanoski | 145 | 1279 | 96152 |
Josh Moss | 139 | 1019 | 89255 |
R. D. Kass | 138 | 1920 | 107907 |
W. Kozanecki | 138 | 1498 | 99758 |
U. Mallik | 137 | 1625 | 97439 |
C. Haber | 135 | 1507 | 98014 |
Christophe Royon | 134 | 1453 | 90249 |