Browse Articles

HMGB-1 as a predictor of major bleeding requiring activation of a massive transfusion protocol in severe trauma

When theory meets experiment: What does it take to accurately predict 1H NMR dipolar relaxation rates in neat liquid water from theory?

In this contribution, we compute the 1H nuclear magnetic resonance (NMR) relaxation rate of liquid water at ambient conditions. We are using structural and dynamical information from Coupled Cluster Molecular Dynamics (CCMD) trajectories generated at CCSD(T) electronic structure accuracy while also considering nuclear quantum effects in addition to consulting information from x-ray and neutron scattering experiments. Our analysis is based on a recently presented computational framework for determining the frequency-dependent NMR dipole–dipole relaxation rate of spin 1/2 nuclei from Molecular Dynamics (MD) simulations, which allows for an effective disentanglement of its structural and dynamical contributions and includes a correction for finite-size effects inherent to MD simulations with periodic boundary conditions. A close to perfect agreement with experimental relaxation data is achieved if structural and dynamical information from CCMD trajectories is considered, leading to a re-balancing of the rotational and translational dynamics, which can also be expressed by the product of the self-diffusion coefficient and the reorientational correlation time of the H–H vector D0 × τHH. The simulations show that this balance is significantly altered when nuclear quantum effects are taken into account. Our analysis suggests that the intermolecular and intramolecular contributions to the 1H NMR relaxation rate of liquid water are almost similar in magnitude, unlike what was predicted earlier from fully classical MD simulations.

A deep-learning approach to parameter fitting for a lithium metal battery cycling model, validated with experimental cell cycling time series

Combining crystal planes and heterojunctions of ZnS/SnS2 boosts photocatalytic performance

A reasonable construction of hybrid heterogeneous photocatalysts possessing fast charge separation and transfer and visible light utilization ability is of great significance for enhancing and achieving highly efficient photochemical conversion. In this study, a series of ZnS/SnS2 heterojunction photocatalysts were prepared by a morphology-controlled strategy, and the regulation of ZnS/SnS2 heterostructure was realized for the photodegradation of methyl violet (MV) under visible light. The results show that as-prepared ZnS/SnS2 consists of hybrid morphological microparticles and exhibits a nanoparticle/nanosheet interspersed structure. The multi-touch interface of the constructed heterostructures can significantly shorten the carrier transport path and greatly promote the charge separation and transfer under the action of the local electric field at the semiconductor/semiconductor interface. Exposed dual-crystal planes of SnS2 coupled with ZnS enrich the active sites and enhance the performance of pure SnS2 and ZnS material. The degradation rate of MV over the optimal heterojunction material (ZnS/SnS2-50) exceeds 91.4% within 90 min under visible light irradiation, which is about 62 times that of MV compared with pristine ZnS.

Clinical characteristics, metastasis patterns, and treatment outcomes of HER2-low breast cancer

Investigation on phase formation and thermoelectric transport properties of CoTe2–CoSe2 solid solution alloys

CoTe2 and CoSe2 alloys have garnered considerable attention in thermoelectric applications due to their high electrical conductivity, tunable electronic properties, and potential for high power factors. In this study, the phase formation behavior and thermoelectric transport properties of a CoTe2–CoSe2 solid solution alloy were investigated by synthesizing a series of Co(Te1−xSex)2 compositions, where x = 0, 0.25, 0.50, 0.75, and 1.0. For x = 0, 0.25, and 0.50, the orthorhombic phase of CoTe2 was observed, while for x = 0.75, the orthorhombic phase of CoTe2 and cubic phase of CoSe2 coexisted. Up to x = 0.50, the power factor decreased slightly as the Hall mobility and the density-of-state effective mass decreased. The total thermal conductivity decreased as x increased to 0.50, owing to a decrease in the electronic and lattice thermal conductivity. Despite the decrease in total thermal conductivity, no significant increase in zT values was observed in the range of x = 0.25–0.50 due to a more pronounced decrease in the power factor. Nevertheless, cubic phase CoSe2 exhibited higher power factors and thus higher zT of 0.13 at 700 K. Further analysis based on single Kane band model suggests that significant enhancement in the power factor and zT could be achieved by reducing the carrier concentration from ∼1021 to ∼1019 cm−3 for all compositions.

An enhanced dung beetle optimizer with multiple strategies for robot path planning

Electric-dipole-momentum sensitive Coulomb explosion in doubly ionized CO dimer and trimer: An environmental effect at molecular-scale

Molecular clusters are aggregates of molecules weakly bound by the van der Waals force between molecules. Removing one electron from each constitutive molecule results in van der Waals bond cleavages through Coulomb explosion. This provides an ideal prototype to further study the environmental effects played by one fragmented ion on the other one at the molecular scale. Here, we report an experimental measurement of the two-body Coulomb explosion of (CO)22+ and (CO)32+, produced in a 40 keV Ar2+ double-electron capture collision with a CO dimer and trimer. Accurate reaction pathways are identified with the advanced ion–ion coincidence and momentum-imaging techniques. The measured kinetic energy release deviates from the calculated results based on the reciprocal of internuclear distance (i.e., Coulomb interaction only) and which, therefore, requires the inclusion of rotational energy of CO+ initiated by molecular electric-dipole momentum. Molecular dynamics simulations reveal that the separation defining the rotational energy takes place within a few hundred fs after the onset of dissociation. This molecular-scale environmental effect significantly brings calculations and measurements of the kinetic energy release into agreement.

Detection of serum composition in pediatric inflammatory multisystem syndrome associated with SARS-CoV-2 and the response for the treatment by FTIR

Microscopic dynamics of enhanced glass-forming ability with minor oxygen addition in bulk metallic glasses

Minor oxygen addition has been proposed as a promising strategy to enhance the performance of metallic glasses, particularly their glass-forming ability. In this work, we investigate the microscopic dynamics of a CuZr glass former with oxygen content up to 2 at. % using molecular dynamics simulations based on specially developed neural network interatomic potentials. Our findings indicate a gradual increase in the glass transition temperature with oxygen addition, with an anomalous peak at 0.4 at. % O. We reveal an anti-correlation of kinetic fragility and dynamic heterogeneity behind this unusual rise, where the system exhibits reduced kinetic fragility alongside more significant dynamic heterogeneity. Using the continuous time random walk method, we show that at 0.4 at. % O, a highly mobile Cu atomic layer forms around O–Zr clusters, resulting in notable dynamic heterogeneity. This dynamic behavior is closely linked to the bonding pattern within the O–Zr network, particularly favoring the configuration with edge and surface sharing. In addition, such structures contribute to a more compact O–Zr network, leading to lower kinetic fragility. These findings provide detailed insights into the microscopic dynamics behind the effects of minor oxygen additions.

Mapping genomic regions affecting sensitivity to bovine respiratory disease on chromosome X using selective DNA pooling

Influence of surface chemistry on Li nucleation energetics on graphene-based surfaces

Lithium metal is a promising high-capacity anode material for solid-state batteries, but it typically suffers from poor cyclability. Carbon scaffold hosts have the potential to improve this performance due to their high electronic conductivity and large surface area, which facilitates lithium-ion adsorption and desorption. Scaffold surface chemistry is known to significantly influence performance outcomes, but the details of these interactions are not fully understood. This study employs first-principles simulations to explore lithium transport and nucleation on graphene anodes with various surface chemistries. Using enhanced sampling techniques, ab initio molecular dynamics, and density functional theory calculations, we find that although surface chemistry has a minimal impact on lithium interfacial transport, it influences surface nucleation significantly. Both heteroatom dopants and intrinsic defects lower the nucleation barrier, creating a more favorable environment for lithium nucleation compared to pristine graphene. In addition, our results reveal a complex interplay between surface lithium concentration, lithium transport, and nucleation kinetics. These findings highlight the potential of surface modifications to precisely control nucleation processes on carbon-based anodes and provide design guidance for reducing dendrite formation and improving the cycle life of solid-state batteries.

Deep learning-based prediction of autoimmune diseases

Comparative study on charge photogeneration dynamics of Y small molecule and polymerized Y small molecule based polymer solar cells

Understanding charge photogeneration processes in polymer solar cells utilizing polymerized Y-molecule acceptors (PYMAs) is of great importance for design and optimization of high-performance solar cells. In this work, excited state dynamics in PYMAs (PYT, PY-DT) and corresponding solar cells were comparably studied with those of Y small molecules (Y5, Y6) by using the steady state and time-resolved spectroscopies as well as time-dependent density functional theory calculation. We find that PYMA (PYT, PY-DT) films exhibit smaller Stokes shifts than that of Y small molecules, indicating a more rigid backbone of PYMAs. Temperature-dependent steady-state PL measurement reveals that compared to small molecule films, the energy barrier from radiative to non-radiative states is smaller in PYMA films. In addition, transient absorption spectroscopy demonstrates that the exciton diffusion process in PYT and PY-DT are mainly intra-chain exciton diffusion mechanism with exciton diffusion coefficients of 1.7 × 10−2 and 2.7 × 10−2 cm2 s−1, respectively, in contrast with the inter-molecular exciton diffusion in Y5 and Y6 films. For the blend films, the phase sizes of acceptors in PM6:PYT and PM6:PY-DT are determined as 2.3 and 3.3 nm, respectively, smaller than that of Y6 (4.7 nm) in the PM6:Y6 film. In addition, unlike bimolecular recombination in classical system PM6:Y6, the PYMA-based all-polymer solar cells exhibit geminate type recombination in ultrafast timescale. We find that carrier lifetime plays a critical role in the performance of PYMA-based polymer solar cells. This work provides a comprehensive understanding of the photophysical properties of PYMAs, which is pivotal for designing highly efficient all-polymer solar cells.

Enhancing feature selection for multi-pose facial expression recognition using a hybrid of quantum inspired firefly algorithm and artificial bee colony algorithm

Transport properties of N + N, O + O, N + O, C + O, C+ + O, C + N, and C + C using an accurate treatment of nonzero spin and electronic angular momentum and including spin–orbit interaction

We have carried out first principles calculations of transport properties of the title atom–atom systems using accurate ab initio electronic structure methods and quantum scattering. We go beyond the Born–Oppenheimer approximation and show how one can properly include the spin and orbital angular momentum of atoms in the calculations. We give the explicit transformation between coupled LS atomic states, where L is the total electron angular momentum and S is the total spin angular momentum, and the diatomic Hund’s case (a) basis. We include both Coulomb spin–orbit interaction as well as the effect of the magnetic-moments of the electrons via the Breit interaction. The relations between the long-range forces of different symmetry electronic states are given for S + P and P + P asymptotes.

Development and validation of a novel bleeding risk prediction tool for aspirin users with a low body mass index

Behavior of water at lipid/water interfaces upon phase transition of the lipid bilayer: Insights from 1D- and 2D-vibrational sum frequency generation spectral calculations from molecular dynamics simulations

We have investigated the structural and dynamical changes of the interfacial water near [1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine] (DMPC) lipid bilayer across various temperatures, ranging from 285 K (gel phase of lipid) to 320 K (liquid phase of lipid), through calculations of one-dimensional (1D) and two-dimensional (2D) vibrational sum frequency generation (VSFG) spectra from molecular dynamics simulations. The 1D-VSFG spectra show a broad positive peak in the hydrogen-bonded region, which means that water molecules are oriented upward toward the lipid bilayer. Although DMPC is a zwitterionic lipid, the negatively charged phosphate group primarily influences the orientation of the water molecules. The absence of a dangling peak in the 1D- and 2D-VSFG spectra shows that the water molecules form hydrogen bonds with the lipid headgroup atoms. The spectral diffusion timescales obtained from the 2D-VSFG metrics of the slope of the nodal line clearly reveal a dynamical crossover and exhibit Arrhenius behavior with different activation energies before and after the melting of the lipid bilayer. Apart from 2D-VSFG, the frequency fluctuation time correlation function also exhibits a dynamical crossover upon melting of the lipid bilayer.

Dynamic responses characteristics of bedrock and overburden layer slope with anchored frame piles based on shaking table test

Electronic structures and spin frustration in Ln3O (Ln = Ce, Sm, Gd) neutrals and anions determined by anion photoelectron spectroscopy

The results of a combined experimental and computational study on Ln3O (Ln = Ce, Sm, and Gd) anion and neutral clusters are presented and analyzed. These three Ln’s were specifically targeted because they vary in their spin state and orbital angular momentum associated with the 4fN subshell occupancies. From the anion PE spectra of Ce3O−, Sm3O−, and Gd3O− measured with 2.330 and 3.495 eV photon energies, we determine the adiabatic electron affinities of the corresponding neutrals to be 0.83 ± 0.03, 1.11 ± 0.05, and 1.17 ± 0.05 eV, respectively. The lowest energy features in all three spectra can readily be reconciled with molecular structures in which the O-atom is central to all three Ln centers, with Ce3O−/Ce3O assuming pyramidal structures and Sm3O−/Sm3O and Gd3O−/Gd3O assuming planar structures. Computationally, the lowest-energy structure of neutral Ce3O is a kite-like structure, which is not consistent with the observed spectrum. The kite-like and pyramidal structures of Ce3O− are predicted to be nearly isoenergetic. Electronic states in which all three 4fN centers are ferromagnetically coupled are predicted to be energetically favored for all species, but spin-frustrated states in which one 4fN center is antiferromagnetically coupled to the remaining centers are computed to lie 0.05 eV higher in energy than the FM-coupled states for Ce3O− and Sm3O−. The PE spectrum of Sm3O− exhibits striking anomalies in the photoelectron angular dependence. This effect is attributed to strong photoelectron–valence electron interactions that drive nominally forbidden changes in the Mf state of the remnant neutral.