Viser treff 21-40 av 527

    • Understanding the Influence of Lewis Acids on CO2 Hydrogenation: The Critical Effect Is on Formate Rotation 

      Pavlovic, Ljiljana; Hopmann, Kathrin Helen (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-11)
      Lewis acids (LAs) have been shown to accelerate hydrogenation of C0<sub>2</sub>, but the underlying mechanistic details remain to be elucidated. We have employed computational methods to investigate how LAs affect CO<sub>2</sub> hydrogenation with a range of known metal-hydrides (L<sub>n</sub>Ir–H, L<sub>n</sub>Ru–H, L<sub>n</sub>Mn–H, L<sub>n</sub>Co–H). Our results show that LAs can alter the ...
    • The Transition from Unfolded to Folded G-Quadruplex DNA Analyzed and Interpreted by Two-Dimensional Infrared Spectroscopy 

      Soenarjo, A Larasati; Lan, Zhihao; Sazanovich, Igor V.; Chan, Yee San; Ringholm, Magnus; Jha, Ajay; Klug, David R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-30)
      A class of DNA folds/structures known collectively as G-quadruplexes (G4) commonly forms in guanine-rich areas of genomes. G4-DNA is thought to have a functional role in the regulation of gene transcription and telomerase-mediated telomere maintenance and, therefore, is a target for drugs. The details of the molecular interactions that cause stacking of the guanine-tetrads are not well-understood, ...
    • Structure/function studies of the NAD<sup>+</sup>-dependent DNA ligase from the poly-extremophile Deinococcus radiodurans reveal importance of the BRCT domain for DNA binding 

      Fernandes, Andreia; Williamson, Adele Kim; Matias, Pedro M.; Moe, Elin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-15)
      Bacterial NAD<sup>+</sup>-dependent DNA ligases (LigAs) are enzymes involved in replication, recombination, and DNA-repair processes by catalyzing the formation of phosphodiester bonds in the backbone of DNA. These multidomain proteins exhibit four modular domains, that are highly conserved across species, with the BRCT (breast cancer type 1 C-terminus) domain on the C-terminus of the enzyme. In ...
    • Local Oxidation States in {FeNO}<sup>6-8</sup> Porphyrins: Insights from DMRG/CASSCF-CASPT2 Calculations 

      Phung, Quan Manh; Nam, Ho Ngoc; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-27)
      A first DMRG/CASSCF–CASPT2 study of a series of paradigmatic {FeNO}<sup>6</sup>, {FeNO}<sup>7</sup>, and {FeNO}<sup>8</sup> heme–nitrosyl complexes has led to substantial new insight as well as uncovered key shortcomings of the DFT approach. By virtue of its balanced treatment of static and dynamic correlation, the calculations have provided some of the most authoritative information available to ...
    • Cavity-Free Continuum Solvation: Implementation and Parametrization in a Multiwavelet Framework 

      Gerez Sazo, Gabriel Adolfo; Remigio Eikås, Roberto Di; Jensen, Stig Rune; Bjørgve, Magnar; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-18)
      We present a multiwavelet-based implementation of a quantum/classical polarizable continuum model. The solvent model uses a diffuse solute–solvent boundary and a position-dependent permittivity, lifting the sharp-boundary assumption underlying many existing continuum solvation models. We are able to include both surface and volume polarization effects in the quantum/classical coupling, with guaranteed ...
    • A Theoretical Search for Stable Terminal Carbides 

      Ghosh, Abhik; Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-20)
      xploratory scalar-relativistic density functional theory (B3LYP*-D3/ZORA-STO-TZ2P) calculations have been used to examine the stability and bonding of pseudotetrahedral Group 8 (Fe, Ru, and Os) and Group 9 (Co, Rh, and Ir) terminal carbide complexes with dδ4 ground states and tripodal tris(N-heterocyclic-carbene) supporting ligands. The calculations predict relatively low adiabatic ionization ...
    • Enhanced teaching and learning outcomes from restructuring a basic organic chemistry course 

      Hansen, Jørn Hedløy; Bayer, Annette; Haugland, Marius Myreng (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-05-10)
      The first course in organic chemistry is tough for many students, and motivation may be an additional serious problem if you are taking the course as a part of your study program but do not intend to become a chemist. The combination of long, speedy traditional lectures, complicated material and the use of an important new language (electron flow arrows) does not contribute to easing the cognitive ...
    • Bacterial extracellular vesicles: towards realistic models for bacterial membranes in molecular interaction studies by surface plasmon resonance 

      Brilkov, Maxim; Stenbakk, Victoria; Jakubec, Martin; Vasskog, Terje; Kristoffersen, Tone; Cavanagh, Jorunn Pauline; Ericson, Johanna Ulrica; Isaksson, Johan Mattias; Flaten, Gøril Eide (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-13)
      One way to mitigate the ongoing antimicrobial resistance crisis is to discover and develop new classes of antibiotics. As all antibiotics at some point need to either cross or just interact with the bacterial membrane, there is a need for representative models of bacterial membranes and efficient methods to characterize the interactions with novel molecules -both to generate new knowledge and to ...
    • Raman spectroscopy online monitoring of biomass production, intracellular metabolites and carbon substrates during submerged fermentation of oleaginous and carotenogenic microorganisms 

      Dzurendová, Simona; Olsen, Pernille Margrethe; Byrtusova, Dana; Tafintseva, Valeria; Shapaval, Volha; Horn, Svein Jarle; Kohler, Achim; Szotkowski, Martin; Marova, Ivana; Zimmermann, Boris (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-18)
      Background - Monitoring and control of both growth media and microbial biomass is extremely important for the development of economical bioprocesses. Unfortunately, process monitoring is still dependent on a limited number of standard parameters (pH, temperature, gasses etc.), while the critical process parameters, such as biomass, product and substrate concentrations, are rarely assessable in-line. ...
    • Radical Group Transfer of Vinyl and Alkynyl Silanes Driven by Photoredox Catalysis 

      Baussiere, Floriane; Haugland, Marius Myreng (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-15)
      Radical group transfer is a powerful tool for the formation of C−C bonds. These processes typically involve radical addition to C−C π bonds, followed by fragmentation of the resulting cyclic intermediate. Despite the advantageous lability of organosilanes in this context, silicon-tethered radical acceptor groups have remained underexplored in radical group transfer reactions. We report a general ...
    • Free-Base Corrole Anion 

      Tarai, Arup; Mallick, Jyotiprakash; Conradie, Jeanet; Kar, Sanjib; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-30)
      Free-base corroles have long been known to be acidic, readily undergoing deprotonation by mild bases and in polar solvents. The conjugate base, however, has not been structurally characterized until now. Presented here is a first crystal structure of a freebase corrole anion, derived from tris(p-cyanophenyl)corrole, as the tetrabuylammonium salt. The low-temperature (100 K) structure reveals ...
    • FAIR+E pathogen data for surveillance and research: lessons from COVID-19 

      Neves, Aitana; Cuesta, Isabel; Hjerde, Erik; Klemetsen, Terje; Salgado, David; van Helden, Jacques; Rahman, Nadim; Fatima, Nazeefa; Karathanasis, Nestoras; Zmora, Pawel; Åkerström, Wolmar Nyberg; Grellscheid, Sushma Nagaraja; Waheed, Zahra; Blomberg, Niklas (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-21)
      The COVID-19 pandemic has exemplified the importance of interoperable and equitable data sharing for global surveillance and to support research. While many challenges could be overcome, at least in some countries, many hurdles within the organizational, scientific, technical and cultural realms still remain to be tackled to be prepared for future threats. We propose to (i) continue supporting global ...
    • Jahn-Teller distortion in bis(terpyridine)nickel(III) – Elongation or compression? 

      Conradie, Jeanet (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-06)
      DFT methods were used to evaluate the type of Jahn-Teller distortion in the low spin d<sup>7</sup> bis(terpyridine)nickel (III) doublet. The strain of the tridentate terpyridine ligand in bis(terpyridine)nickel(III) leads to longer Ni(III)-N terminal bond lengths than the Ni(III)-N central bonds. In addition, in all DFT optimized bis(terpyridine)nickel (III) molecules, the one set of Ni(III)-N ...
    • Constrained DFT-based magnetic machine-learning potentials for magnetic alloys: a case study of Fe–Al 

      Tantardini, Christian; Kotykhov, Alexey S.; Gubaev, Konstantin; Hodapp, Max; Shapeev, Alexander V.; Novikov, van S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-11-13)
      We propose a machine-learning interatomic potential for multi-component magnetic materials. In this potential we consider magnetic moments as degrees of freedom (features) along with atomic positions, atomic types, and lattice vectors. We create a training set with constrained DFT (cDFT) that allows us to calculate energies of confgurations with non-equilibrium (excited) magnetic moments and, ...
    • Towards high-throughput screening (HTS) of polyhydroxyalkanoate (PHA) production via Fourier transform infrared (FTIR) spectroscopy of Halomonas sp. R5-57 and Pseudomonas sp. MR4-99 

      Christensen, Mikkel; Chiciudean, Iulia; Jablonski, Piotr; Tănase, Ana-Maria; Shapaval, Volha; Hansen, Hilde (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-08)
    • Bulky, electron-rich, renewable: analogues of Beller's phosphine for cross-couplings 

      van der Westhuizen, Danielle; Castro, Abril C; Hazari, Nilay; Gevorgyan, Ashot (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-30)
      In recent years, considerable progress has been made in the conversion of biomass into renewable chemicals, yet the range of value-added products that can be formed from biomass remains relatively small. Herein, we demonstrate that molecules available from biomass serve as viable starting materials for the synthesis of phosphine ligands, which can be used in homogeneous catalysis. Specifically, ...
    • Influence of Fluorinated Substituents on the Near-Infrared Phosphorescence of 5d Metallocorroles 

      Johannessen, Krister Engedal; Johansen, Martin Amund Langaas; Einrem, Rune Finsås; McCormick McPherson, Laura J.; Alemayehu, Abraham; Borisov, Sergey M.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-12)
      The influence of fluorinated substituents on the luminescent properties of rhenium-oxo, osmium-nitrido, and gold triarylcorroles was studied via a comparison of four ligands: triphenylcorrole (TPC), tris(ptrifluoromethylphenyl)corrole (TpCF<sub>3</sub>PC), tris{3,5-bis(trifluoromethyl)- phenyl}corrole (T3,5-CF<sub>3</sub>PC), and tris(pentafluorophenyl)corrole (TPFPC). For each metal series ...
    • Initial characterization of an iron superoxide dismutase from Thermobifida fusca 

      Hamre, Anne Grethe; Al-Sadawi, Rim; Johannesen, Kirsti Merete; Bisarro, Bastien; Kjendseth, Åsmund Røhr; Leiros, Hanna-Kirsti S.; Sørlie, Morten (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-19)
      Superoxide dismutases (SODs) are enzymes that catalyze the dismutation of the superoxide radical anion into O<sup>2</sup> and H<sup>2</sup>O<sup>2</sup> in a two-step reaction. They are ubiquitous to all forms of life and four different types of metal centers are detected, dividing this class of enzymes into Cu-/Zn-, Ni-, Mn-, and Fe-SODs. In this study, a superoxide dismutase from the ...
    • Insights into the role of three Endonuclease III enzymes for oxidative stress resistance in the extremely radiation resistant bacterium Deinococcus radiodurans 

      Rollo, Filipe; Martins, Guilherme D.; Gouveia, André G.; Ithurbide, Solenne; Servant, Pascale; Romão, Célia V.; Moe, Elin (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-12)
      The extremely radiation and desiccation resistant bacterium Deinococcus radiodurans possesses three genes encoding Endonuclease III-like enzymes (DrEndoIII1, DrEndoIII2, DrEndoIII3). In vitro enzymatic activity measurements revealed that DrEndoIII2 is the main Endonuclease III in this organism, while DrEndoIII1 and 3 possess unusual and, so far, no detectable EndoIII activity, respectively. In ...
    • Cost-Efficient High-Resolution Linear Absorption Spectra Through Extrapolating the Dipole Moment from Real-Time Time-Dependent Electronic-Structure Theory 

      Hauge, Eirill Strand; Kristiansen, Håkon Emil; Konecny, Lukas; Kadek, Marius; Repisky, Michal; Pedersen, Thomas Bondo (Journal article; Tidsskriftartikkel; Peer reviewed, 2023)
      We present a novel function fitting method for approximating the propagation of the time-dependent electric dipole moment from real-time electronic structure calculations. Real-time calculations of the electronic absorption spectrum require discrete Fourier transforms of the electric dipole moment. The spectral resolution is determined by the total propagation time, i.e. the trajectory length of the ...