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Study of low-energy electron-induced dissociation of 1-propanol
The fragmentation of 1-propanol resulting from dissociative electron attachment has been explored across an energy range of 3.5–16 eV. Four distinct ion species are identified: H−, O−, OH−, and C3H7O−. The OH− ion exhibited a prominent peak near 8.7 eV, along with a small hump near 5.6 eV. Complementary channels led to the formation of the H− and C3H7O− ions. Both of these two ions exhibit a sharp peak near 6 eV and broad overlapping resonances between 7 and 12 eV. The observed ion yields of distinct dissociation fragments in this study, when compared with those from previously studied alcohols, suggest site-specific fragmentation of alcohols during dissociative electron attachment. To gain a deeper understanding of the dissociation pathways, density functional theory calculations were conducted, revealing the threshold energies for each channel. These threshold energies aligned well with the experimental uncertainties.
Impact of atomic substitution on core-hole relaxation dynamics: A study of Br2 and IBr
Understanding inner-shell decay processes in heavy-element molecules is essential for unraveling x-ray-induced photodynamics and advancing molecular imaging techniques. In this study, we investigate the influence of atomic substitution on core-hole relaxation dynamics and molecular fragmentation in Br2 and IBr, initiated by x-ray ionization absorption at the Br K-edge. Using a combination of x-ray/ion coincidence measurements and Monte Carlo/molecular dynamics simulations, we track the charge distribution and the kinetic energy release (KER) of fragment ions with a total charge from 2+ to 8+. For both molecules, the simulated KER values show good agreement with experiment across different fragmentation channels. Our comparison reveals that substituting Br with the heavier I atom in IBr has a minimal impact on the inner-shell electronic decay process but significantly influences nuclear motion, leading to slower dissociation and thus a KER close to the Coulomb limit—an effect attributed to the atomic mass. These findings highlight the interplay between electronic and nuclear effects in molecular fragmentation, particularly in heavy-element species, and provide new insights into medical therapies, structural biology, and astrophysics.
Revisiting the electron affinity of selenium
The electron affinity (EA) of atomic selenium, previously established as 16 297.276(9) cm−1 based on the laser photodetachment microscopy (LPM) measurements in 2012, exhibited a significant deviation from other earlier experimental values, yet it remained the accepted reference standard for over a decade. In this letter, we re-examined the EA of Se using the slow-electron velocity-map imaging method and revealed a substantial deviation in the LPM result. Measurements for the different isotopes of Se and the energy-level splitting of the neutral Se atom’s 3P2–3P1 further verified the accuracy and robustness of our SEVI method. Based on this experimental evidence, we recommended a revised EA(Se) value of 16 297.78(4) cm−1, which is in excellent agreement with the previous laser photodetachment threshold experimental results.
Publisher’s Note: “Unveiling the dynamical genesis of quantum entanglement in linear systems: Internal causality breaking in the reduced subsystem evolution” [J. Chem. Phys. 163, 234107 (2025)]
<i>Ab initio</i> study of sum-frequency vibrational spectroscopy of interfacial water bending mode
Understanding the response of interfacial water to electric fields is critical for elucidating its unique vibrational dynamics. Here, we employ a mixed quantum/classical approach coupled with neural network-based molecular dynamics (MD) simulations to compute the in-plane transverse electric field at hydrogen sites of interfacial water. Our results reveal a bidirectional field distribution (positive and negative values), where a positive field blueshifts the bending mode frequency, while a negative field fails to induce a redshift in sum-frequency vibrational spectroscopy (SFVS). By integrating ab initio MD simulations with quantum chemistry calculations, we reproduce experimental SFVS and explain the absence of a redshifted bending peak. Crucially, we identify the electric quadrupole contribution as the dominant factor governing the bending mode response. The proposed ab initio framework maintains high accuracy while reducing computational costs significantly, offering a robust tool for studying the interfacial spectroscopy of water.
Impact of the electron attachment to the alanyl glycine and glycyl alanine conformers
The low-energy electron (LEE) attachment to biological molecules can result in irreversible damage. The attachment of LEEs to DNA, amino acids, peptides, and proteins has a significant impact due to their diverse biological applications. This study focuses on the effect of the electron attachment to the conformers of alanyl glycine and glycyl alanine dipeptide molecules. This study used a quantum mechanical approach to extract the low-lying conformers of the dipeptide molecules and performed atom-centered density matrix propagation simulation to assess the impact of the electron attachment at 2.0 eV. We observed a dipole-bound state to a π* valence-bound state transition based on the singly occupied molecular orbitals’ analysis. It was observed that different conformers have distinct impacts on electron attachment to the system, and strong intramolecular H-bonds give extra stability to the system toward the dissociative electron attachment (DEA). The latter part of this work focuses on identifying two low-lying π* resonance states, as the DEA process involves a π* to σ* transition, which was studied using the complex absorbing potential approach. Our results align reasonably well with experimental observations for the alanyl glycine and glycyl alanine molecules in the gas phase.
Mesoscale transport of enveloped viruses
Enveloped viruses are characterized by spike proteins that protrude from and decorate the viral membrane. These proteins play a crucial role in host cell interactions and exhibit dynamic behaviors, such as tilting, lateral diffusion, and clustering, which vary across different types of enveloped viruses. For instance, SARS-CoV-2 spikes tilt to facilitate receptor binding, influenza spikes migrate during infection, and HIV (Human Immunodeficiency Virus) spikes migrate and cluster to enhance infectivity. In this study, we investigate how such dynamics influence the virus mobility. We characterize viral mobility through translational and rotational diffusion coefficients using a mesoscopic model that incorporates the dynamics of both the flexible spike proteins and the viral envelope. Using the smoothed dissipative particle dynamics method, we construct three virion models with varying spike flexibility. The first is a fully rigid virus with static spikes, the second is a model with spikes that tilt but remain fixed in position, and the third is a model allowing both tilting and lateral diffusion of spikes across the envelope. Our results show that spike flexibility primarily affects rotational diffusion, whereas the envelope dominates the translational mobility of the virus. We also explore spike clustering driven purely by hydrodynamic interactions and compare with an experimental model reference using DNA-PAINT super-resolution imaging of HIV-like particles. We identify that hydrodynamic interactions alone can be responsible for the dynamic clustering of spike proteins where the characteristic size and lifespan of such clusters indicate predominantly doublet and triplet formations. Our findings highlight the role of spike dynamics in whole virion mobility and motivate further investigations with time-resolved experimental evidence to fully characterize clustering behavior.
Modeling and application of alzheimer’s disease complex trait prediction based on multi-task learning
Experimental study on reinforcement treatment of coastal silty soft soil
Compost application enhances soil quality, growth, and yield of durum wheat under saline conditions
Gut microbiota and metabolic pathway profiles in infected and non-infected heart transplant patients before and after surgery
An emission-capacitated vehicle routing model for sustainable urban waste collection using hybrid guided local search
Abstract Urban logistics services, such as municipal solid waste collection, play a crucial role in shaping cities’ sustainability. These services are significant contributors to fuel consumption, operational costs, and greenhouse gas emissions. Traditional vehicle routing models, such as the capacitated vehicle routing problem with time windows, typically focus on minimizing distance or cost, which indirectly impacts emissions. However, these models fail to address the growing need for sustainable and environmentally conscious logistics strategies. This study introduces the emission-capacitated vehicle routing problem with time windows (E-CVRPTW), a novel optimization formulation that explicitly integrates a load-dependent fuel consumption model and an emission objective. The formulation also incorporates fleet-level policy constraints, including a carbon budget and an emission-intensity ceiling, providing a more comprehensive approach to minimizing both operational costs and environmental impacts. To solve the E-CVRPTW, a hybrid guided local search (HGLS) approach is employed with additional embedded features: (i) a novel cheapest insertion first initialization to generate high-quality starting solutions; (ii) adaptive feature penalties to diversify the search, while controlled neighborhood switching between 2-opt and 3-opt moves ensures an optimal balance between intensification and diversification. These features help the proposed algorithm to achieve better optimization solutions. Moreover, a rigorous experimental protocol using the Solomon and Gehring-Homberger benchmark instances demonstrates that HGLS, with additional features, significantly improves fuel consumption and emission reductions compared to baseline heuristics. Furthermore, a real-world case study on municipal waste collection reveals that optimized routing plans reduce fuel consumption and CO 2 emissions by 9–11% while lowering total costs by 8–9%. The optimized solutions also meet strict policy targets under constrained conditions, showcasing the potential of E-CVRPTW in real-world applications. A sensitivity analysis explores the trade-offs among fuel prices, carbon prices, and emission weights, providing valuable insights for decision-makers in urban service planning and sustainability-focused policy formulation.
Comprehensive assessment of gold nanorod-induced genotoxicity using multi-model biological systems
Abstract Using a variety of biological models, including human cell lines, Salmonella typhimurium , Escherichia coli , and Saccharomyces cerevisiae haploid knockout (YKO) strains, this study aimed to examine the genotoxic effects of gold nanorods (AuNRs). Salmonella and E. coli strains will be cultivated on LB agar plates and incubated for 16 h at 37 °C to perform bacterial tests. The cultures will be subjected to varying quantities of AuNRs after incubation. The comet test will be used to assess the degree of DNA damage in these bacterial strains. Likewise, haploid knockout strains of S. cerevisiae will be grown on YPD plates and incubated at 37 °C for 24 to 48 h before being exposed to different doses of AuNRs for the yeast model. Following treatment, the comet assay will also be used to evaluate DNA damage in yeast cells. The GeneMANIA platform, which offers functional association data to help the interpretation of the genetic findings, will be used to predict protein-protein interaction networks. The HepG2 liver cancer cell line’s expression levels of cancer-related genes will also be examined using real-time PCR. Particular attention was paid to the p53 , Bax , and Bcl-2 genes, which are homologous to the chosen yeast genotypes. Findings and outcomes: When compared to untreated control groups, the comet assay findings for both yeast and bacterial cells showed increased tail length, tail DNA percentage, and tail moment, indicating severe DNA damage ( P < 0.05). According to a gene expression study, Bcl-2 expression was significantly downregulated, whereas p53 and Bax transcripts were upregulated after being exposed to AuNRs. Analysis of protein-protein interactions provided additional information about the functional arrangement of related proteins. Overall, the results indicate that gold nanorods have genotoxic qualities and lower malignant cell viability.