1,076 results match your criteria: "AlbaNova University Center[Affiliation]"

Restoring rotational symmetry of multicomponent wavefunctions with nuclear orbitals.

J Chem Phys

January 2025

Department of Physics, AlbaNova University Center, Stockholm University, S-106 91 Stockholm, Sweden.

In this work, we present a non-orthogonal configuration interaction (NOCI) approach to address the rotational corrections in multicomponent quantum chemistry calculations where hydrogen nuclei and electrons are described with orbitals under Hartree-Fock (HF) and density functional theory (DFT) frameworks. The rotational corrections are required in systems such as diatomic (HX) and nonlinear triatomic molecules (HXY), where localized broken-symmetry nuclear orbitals have a lower energy than delocalized orbitals with the correct symmetry. By restoring rotational symmetry with the proposed NOCI approach, we demonstrate significant improvements in proton binding energy predictions at the HF level, with average rotational corrections of 0.

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Vibrational polaritons are formed by strong coupling of molecular vibrations and photon modes in an optical cavity. Experiments have demonstrated that vibrational strong coupling can change molecular properties and even affect chemical reactivity. However, the interactions in a molecular ensemble are complex, and the exact mechanisms that lead to modifications are not fully understood yet.

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Engineering skyrmion from spin spiral in transition metal multilayers.

J Phys Condens Matter

December 2024

Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Kattankulathur, 603203 Chennai, Tamil Nadu, India.

Skyrmions having topologically protected field configurations with particle-like properties play an important role in various fields of science. Our present study focus on the generation of skyrmion from spin spiral in the magnetic multilayers of 4d/Fe/Ir(111) with 4d = Y, Zr, Nb, Mo, Ru, Rh. Here we investigate the impact of 4d transition metals on the isotropic Heisenberg exchanges and anti-symmetric Dzyaloshinskii-Moriya interactions originating from the broken inversion symmetry at the interface of 4d/Fe/Ir(111) multilayers.

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The phytopathogenic oomycete Phytopythium helicoides, previously known as Pythium helicoides, has emerged as a new threat to the Shatangju citrus cultivar (Citrus reticulata cv. Shatangju; '' in Chinese) in southern China. To enable rapid diagnosis and control of the leaf blight and stem rot caused by P.

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Recent experiments and theoretical studies strongly indicate that water exhibits a liquid-liquid phase transition (LLPT) in the supercooled domain. An open question is how the LLPT of water can affect the properties of aqueous solutions. Here, we study the structural and thermodynamic properties of supercooled glycerol-water microdroplets at dilute conditions (χ = 3.

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Ultrafast Mapping of Electronic and Nuclear Structure in the Photo Dissociation of Nitrogen Dioxide.

J Phys Chem Lett

December 2024

Max Born Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max Born Str. 2A, 12489 Berlin, Germany.

We investigate the photoinduced dissociation reaction of NO → NO + O upon electronic excitation of the X̃A (D) to the ÃB (D) state by femtosecond X-ray absorption spectroscopy at the nitrogen K-edge. We obtain key insight into the chemical bond breaking event and its associated electronic structural dynamics. Calculations of the photoinduced reaction allow to assign the transient absorption features at time scales of 10-50 fs to wave packet motions in the excited D and ground D states, followed by the formation of the NO photoproduct with a 255 ± 23 fs time constant.

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Article Synopsis
  • The study measures and analyzes time-resolved photoelectron spectra and excited-state simulations for photoexcited gas-phase molecules Fe(CO) and Cr(CO), using 266 nm pump pulses and 23 eV probing photons.
  • It finds that photoelectron intensities increase in energy over time, transitioning from bound excited states to dissociated species, with notable differences between the two molecules.
  • The research indicates that Cr(CO) exhibits faster excited-state and dissociation dynamics than Fe(CO), likely due to a stronger coupling between these states, evidenced by overlapping energy manifolds in Cr(CO).
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Throughout the course of the SARS-CoV-2 pandemic, genetic variation has contributed to the spread and persistence of the virus. For example, various mutations have allowed SARS-CoV-2 to escape antibody neutralization or to bind more strongly to the receptors that it uses to enter human cells. Here, we compared two methods that estimate the fitness effects of viral mutations using the abundant sequence data gathered over the course of the pandemic.

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The lack of dense random-access memory is one of the main obstacles to the development of digital superconducting computers. It has been suggested that AVRAM cells, based on the storage of a single Abrikosov vortex-the smallest quantized object in superconductors-can enable drastic miniaturization to the nanometer scale. In this work, we present the numerical modeling of such cells using time-dependent Ginzburg-Landau equations.

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Article Synopsis
  • The study presents a nano delivery system specifically designed to target various stages of osteoclast development, which are cells involved in bone resorption.
  • The innovative approach aims to improve the effectiveness of treatments for bone-related diseases by precisely delivering therapeutic agents to osteoclasts at different maturation stages.
  • Results from the research demonstrate the potential of this nano system to enhance the treatment outcomes and provide a new strategy for managing conditions like osteoporosis.
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Impact of site-specific conjugation strategies on the pharmacokinetics of antibody conjugated radiotherapeutics.

Eur J Med Chem

December 2024

Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden; Lund University Cancer Centre (LUCC), Lund University, Lund, Sweden. Electronic address:

Antibody radionuclide conjugates are an emerging modality for targeted imaging and potent therapy of disseminated disease. Coupling of radionuclides to monoclonal antibodies (mAbs) is typically achieved by applying non-site-specific labelling techniques. With the ambition of reducing variability, increasing labelling efficacy and stability, several site-specific conjugation strategies have been developed in recent years for toxin- and fluorophore-mAb conjugates.

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The fate of severe acute respiratory syndrome coronavirus-2 and pepper mild mottle virus at various stages of wastewater treatment process.

Ecotoxicol Environ Saf

October 2024

Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm SE-106 91, Sweden.

This study investigated the efficiency of the treatment processes of wastewater treatment plants (WWTPs) to remove severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and pepper mild mottle virus (PMMoV) from the wastewater and sewage sludge, as well as the influence of the mode of operation on the quality of the treated wastewater. SARS-CoV-2 and PMMoV were detected and quantified at different stages of the wastewater and sludge treatment process of three major WWTPs in Stockholm, Sweden. The results showed that primary, biological, and advanced membrane treatment processes are effective in removing SARS-CoV-2 from the wastewater with removal efficiencies of 99-100 % for all WWTPs, while the virus was accumulated in the primary and waste-activated sludges due to higher affinity to biosolids.

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Rich momentum-dependent electronic structure naturally arises in solids with long-range crystalline symmetry. Reliable and scalable quantum technologies rely on materials that are either not perfect crystals or non-crystalline, breaking translational symmetry. This poses the fundamental questions of whether coherent momentum-dependent electronic states can arise without long-range order, and how they can be characterized.

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Discovery of alkaline laccases from basidiomycete fungi through machine learning-based approach.

Biotechnol Biofuels Bioprod

September 2024

Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Biocenter 1, Viikinkaari 9, 00790, Helsinki, Finland.

Background: Laccases can oxidize a broad spectrum of substrates, offering promising applications in various sectors, such as bioremediation, biomass fractionation in future biorefineries, and synthesis of biochemicals and biopolymers. However, laccase discovery and optimization with a desirable pH optimum remains a challenge due to the labor-intensive and time-consuming nature of the traditional laboratory methods.

Results: This study presents a machine learning (ML)-integrated approach for predicting pH optima of basidiomycete fungal laccases, utilizing a small, curated dataset against a vast metagenomic data.

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Two-Positron-bonded Dihalides: PsXY (X, Y=F, Cl, Br).

Chemistry

December 2024

Department of Chemistry, Universidad Nacional de Colombia, Av. Cra 30 45-03, Bogotá, Colombia.

Article Synopsis
  • The study investigates the stability and properties of complexes formed by halide anions and positrons using advanced computational methods to analyze their energetic configurations.
  • Findings show that these positronic complexes are globally stable due to the formation of two-positron bonds, which contrasts with some less stable configurations like PsH that can easily emit positrons.
  • The research also highlights similarities between two-positron dihalides and traditional two-electron dialkali molecules, suggesting notable trends in bonding properties, with the positron-containing complexes exhibiting unique characteristics such as shorter bond lengths and higher bond energies compared to their electron counterparts.
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Binary progenitor systems for Type Ic supernovae.

Nat Commun

September 2024

Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland.

Core-collapse supernovae are explosions of massive stars at the end of their evolution. They are responsible for metal production and for halting star formation, having a significant impact on galaxy evolution. The details of these processes depend on the nature of supernova progenitors, but it is unclear if Type Ic supernovae (without hydrogen or helium lines in their spectra) originate from core-collapses of very massive stars (>30 M) or from less massive stars in binary systems.

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Evaluation of ABD-Linked RM26 Conjugates for GRPR-Targeted Drug Delivery.

ACS Omega

August 2024

Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden.

Article Synopsis
  • Targeting the gastrin-releasing peptide receptor (GRPR) using the peptide RM26 has shown promise in imaging for prostate cancer, but its quick clearance from the body limits its effectiveness as a therapeutic agent.
  • To prolong the peptide's half-life, researchers have experimented with an albumin-binding domain (ABD) to create a new series of ABD-RM26 conjugates aimed at improving the stability and reducing kidney uptake.
  • The second-generation construct ABD-RM26 Gen 2A demonstrated significantly lower kidney uptake—almost 6 times less—improving biodistribution, but it had reduced effectiveness in binding to GRPR, indicating potential for further development in targeted cancer therapy.
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We predict the emergence of a state of matter with intertwined ferromagnetism, charge order, and topology in fractionally filled moiré superlattice bands. Remarkably, these quantum anomalous Hall crystals exhibit a quantized integer Hall conductance that is different than expected from the filling and Chern number of the band. Microscopic calculations show that this phase is robustly favored at half-filling (ν=1/2) at larger twist angles of the twisted semiconductor bilayer tMoTe_{2}.

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Development and implementation of assays to monitor human adenovirus F40/41 in wastewater: Trends preceding, during, and following the non-A-to-E hepatitis outbreak in Stockholm.

Environ Int

August 2024

Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden.

Human adenovirus (HAdV) type F41 has been identified as a possible cause of the non-A-to-E hepatitis outbreak. This study uses wastewater monitoring to track HAdV F40 and F41, supporting clinical investigations and providing insights into the pathogen's role in the outbreak. Given the limited clinical monitoring in Sweden of HAdV-F40/41, this approach also helps estimate the true infection burden of this pathogen during the outbreak.

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Quasimolecular orbitals in cluster Mott insulators provide a route to tailor exchange interactions, which may yield novel quantum phases of matter. We demonstrate the cluster Mott character of the lacunar spinel GaTa_{4}Se_{8} using resonant inelastic x-ray scattering (RIXS) at the Ta L_{3} edge. Electrons are fully delocalized over Ta_{4} tetrahedra, forming quasimolecular J_{tet}=3/2 moments.

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Strong Gravitational Lensing and Microlensing of Supernovae.

Space Sci Rev

February 2024

Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland.

Strong gravitational lensing and microlensing of supernovae (SNe) are emerging as a new probe of cosmology and astrophysics in recent years. We provide an overview of this nascent research field, starting with a summary of the first discoveries of strongly lensed SNe. We describe the use of the time delays between multiple SN images as a way to measure cosmological distances and thus constrain cosmological parameters, particularly the Hubble constant, whose value is currently under heated debates.

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The problem of asymptotic non-adiabatic couplings in heavy particle collisions is treated using the reprojection method. The mixing matrix that mixes the asymptotic solutions of the coupled states to obtain appropriate boundary conditions is here derived to second order, yielding a faster convergence of the cross section. In addition, the reprojection method is implemented in a diabatic representation and applied to inelastic scattering of Li + Na and H + H collisions and to mutual neutralization in H+ + H- collisions.

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Van der Waals heterostructures have recently emerged as an exciting platform for investigating the effects of strong electronic correlations, including various forms of magnetic or electrical orders. Here, we perform an unbiased exact diagonalization study of the effects of interactions on topological flat bands of twisted transition metal dichalcogenides (TMDs) at odd integer fillings. For hole-filling ν_{h}=1, we find that the Chern insulator phase, expected from interaction-induced spin-valley polarization of the bare bands, is quite fragile, and gives way to spontaneous multiferroic order-coexisting ferroelectricity and ferromagnetism, in the presence of long-range Coulomb repulsion.

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Strong coupling of organic molecules to the vacuum field of a nanoscale cavity can be used to modify their chemical and physical properties. We extend the Tavis-Cummings model for molecular ensembles and show that the often neglected interaction terms arising from the static dipole moment and the dipole self-energy are essential for a correct description of the light-matter interaction in polaritonic chemistry. On the basis of a full quantum description, we simulate the excited-state dynamics and spectroscopy of MgH+ molecules resonantly coupled to an optical cavity.

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