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Institution

University of Vienna

EducationVienna, Austria
About: University of Vienna is a education organization based out in Vienna, Austria. It is known for research contribution in the topics: Population & Stars. The organization has 44686 authors who have published 95840 publications receiving 2907492 citations.


Papers
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Journal ArticleDOI
TL;DR: A plane-wave-based algorithm was implemented in VASP (Vienna ab-initio simulation package) to allow for the calculation of the exact exchange of exact exchange and hybrid functionals, with excellent agreement for both atomization energies and geometries.
Abstract: Present local and semilocal functionals show significant errors, for instance, in the energetics of small molecules and in the description of band gaps. One possible solution to these problems is the introduction of exact exchange and hybrid functionals. A plane-wave-based algorithm was implemented in VASP (Vienna ab-initio simulation package) to allow for the calculation of the exact exchange. To systematically assess the precision of the present implementation, calculations for the 55 molecules of the G2-1 quantum chemical test set were performed applying the PBE and PBE0 functionals. Excellent agreement for both atomization energies and geometries compared with the results obtained by GAUSSIAN 03 calculations using large basis sets (augmented correlation consistent polarized valence quadruple zeta for the geometry optimization and augmented correlation-consistent polarized valence quintuple zeta for the energy calculations) was found. The mean absolute error for atomization energies between VASP and the experiment is 8.6 and 3.7 kcalmol, as calculated with the PBE and PBE0 functionals, respectively. The mean deviations between VASP and GAUSSIAN are 0.46 and 0.49 kcalmol for the PBE and PBE0 functionals, respectively.

699 citations

01 Jan 2008
TL;DR: The recent achievement of oxaliplatin for the treatment of colon cancer should not belie the imbalance between a plethora of investigated complexes and a very small number of clinically approved platinum drugs.
Abstract: Triggered by the resounding success of cisplatin, the past decades have seen tremendous efforts to produce clinically beneficial analogues. The recent achievement of oxaliplatin for the treatment of colon cancer should, however, not belie the imbalance between a plethora of investigated complexes and a very small number of clinically approved platinum drugs. Strategies opening up new avenues are increasingly being sought using complexes of metals other than platinum such as ruthenium or gallium. Based on the chemical differences between these metals, the spectrum of molecular mechanisms of action and potential indications can be broadened substantially. Other approaches focus on complexes with tumour-targeting properties, thereby maximizing the impact on cancer cells and minimizing the problem of adverse side effects, and complexes with biologically active ligands.

698 citations

Journal ArticleDOI
TL;DR: The activating function is discussed for monopolar electrodes but the principle can be extended to arbitrary configurations of electrodes and the activity of the axon depends on the second space derivative of the extracellular medium.
Abstract: Extracellular electrodes produce electrical fields at the outside of nerve fibers. Discretization of the axon's length coordinate allows simulation of the excitation by a system of differential equations in time, and difference equations in space. For myelinated fibers this segmentation is naturally given by the nodes of Ranvier, whereas unmyelinated axons can be segmented arbitrarily. In both cases the equations are similar and can be treated in parallel. The activity of the axon depends on the second space derivative of the extracellular medium. The activating function is discussed for monopolar electrodes but the principle can be extended to arbitrary configurations of electrodes.

697 citations

Journal ArticleDOI
TL;DR: The results of this multicenter investigation provide the basis for the routine clinical evaluation of patients with olfactory disorders using “Sniffin’ Sticks” as a composite TDI score, i.e., the sum of results obtained for threshold, discrimination and identification measures.
Abstract: “Sniffin’ Sticks” is a test of nasal chemosensory performance that is based on penlike odor-dispensing devices. It is comprised of three tests of olfactory function: tests for odor threshold, discrimination and identification. Previous work has already established its test-retest reliability and validity in comparison to established measures of olfactory sensitivity. The results of this test are presented as a composite TDI score – i.e., the sum of results obtained for threshold, discrimination and identification measures. The present multicenter investigation aimed at providing normative values in relation to different age groups. To this end, 966 patients were investigated in 11 centers. An additional study tried to establish values for the identification of anosmic patients, with 70 anosmics investigated in five specialized centers where the presence of anosmia was confirmed by means of olfactory evoked potentials. For healthy subjects, the TDI score at the 10th percentile was 24.5 in subjects younger than 15 years, 30.3 for ages from 16 to 35 years, 28.8 for ages from 36 to 55 years and 27.5 for subjects older than 55 years. While these data can be used to estimate individual olfactory abilities in relation to a subject’s age, hyposmia was defined as the 10th percentile score of 16- to 35-year-old subjects. Our latter study revealed that none of 70 anosmics reached a TDI score higher than 15. This score of 15 is regarded as the cut-off value for functional anosmia. These results provide the basis for the routine clinical evaluation of patients with olfactory disorders using “Sniffin’ Sticks.”

695 citations

Journal ArticleDOI
TL;DR: Understanding how non‐viral vectors initiate gene expression could lead to the development of new future vectors with enhanced efficacy in non-viral gene therapy.
Abstract: Background Efficient gene transfer is a major challenge for non-viral gene therapy. Understanding how non-viral vectors initiate gene expression could lead to the development of new future vectors with enhanced efficacy. Methods Linear or branched polyethylenimine (PEI)/DNA complexes were generated in varying salt conditions and their transfection efficiencies were compared in vitro and in vivo using reporter genes, luciferase and green fluorescent protein, and rhodamine labeled DNA (pGeneGrip™). Results The transfection efficiency of linear PEI22/DNA in vitro was generally greater than that of branched PEI/DNA when complexes were generated in salt containing buffer. However, PEI complexes generated under salt-free conditions generally had low transfection activity in vitro. In contrast, PEI22/DNA salt-free complexes were highly active in vivo. Branched PEI/DNA and salt containing PEI22/DNA complexes were generally 10–100-fold less active than the salt-free PEI22/DNA complexes. Salt-free PEI22/DNA complexes were small, but subsequently grew into aggregates when salt was added. In contrast, PEI25/DNA complexes remained small even after salt was added under the same conditions. Furthermore, PEI22/pGeneGrip™ complexes formed large aggregates associated with the cell membrane, cytoplasm and nucleus, while branched PEI complexes remained as small distinct particles associated with the cell membrane or in the cytoplasm. Conclusions Branched and linear PEI/DNA complexes differ in their ability to transfect cells. The greater efficiency of linear PEI might be due to an inherent kinetic instability under salt conditions. Understanding how to employ this kinetic instability of linear PEI could help in designing future vectors with greater flexibility and transfection efficiency in vivo. Copyright © 2001 John Wiley & Sons, Ltd.

695 citations


Authors

Showing all 45262 results

NameH-indexPapersCitations
Tomas Hökfelt158103395979
Wolfgang Wagner1562342123391
Hans Lassmann15572479933
Stanley J. Korsmeyer151316113691
Charles B. Nemeroff14997990426
Martin A. Nowak14859194394
Barton F. Haynes14491179014
Yi Yang143245692268
Peter Palese13252657882
Gérald Simonneau13058790006
Peter M. Elias12758149825
Erwin F. Wagner12537559688
Anton Zeilinger12563171013
Wolfgang Waltenberger12585475841
Michael Wagner12435154251
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20241
2023419
20221,085
20214,479
20204,533
20194,225