Browse Articles
Discover research articles across all indexed journals
Determination of intramolecular isotope effects in the Be+(2P3/2) + HD reaction
Isotope effects in the Be+(2P3/2) + HD reaction were investigated using an integrated ion trap and high-resolution time-of-flight mass spectrometer at a collision energy of 285 K (Ecoll/kB). The total rate constant was measured to be (1.4 ± 0.1) × 10−9 cm3/s, consistent with predictions from classical capture theory. The branching ratio of BeD+ + H to BeH+ + D was determined for the first time and found to be 3.7 ± 0.6, indicating a significant isotope effect. Comparisons with the pairwise energy model and phase space theory suggest that the reaction does not proceed through a purely abstraction or insertion mechanism. Time-dependent quantum dynamics calculations further underscore the importance of accurately describing short-range interactions to reproduce the observed branching behavior. These results establish a well-characterized benchmark system for studying isotope effects and reaction mechanisms in ion–molecule collisions under quantum-state control.
Investigation of mechanical properties and micromechanisms of saline soil modified with synthetic fibers
To study the mechanical properties and microscopic morphology of salt-affected soil after being improved by fiber types and contents, the article analyzes the unconfined compressive strength and shear strength of the sulfate-affected soil in Kashi, Xinjiang, China, which four different fiber contents have improved. Some samples are tested by scanning electron microscope (SEM) and nuclear magnetic resonance (NMR) microanalysis. The article selects the sample with the highest improved unconfined compressive strength for dry-wet cycling and dissolution test. The results show that polypropylene, polyester, and glass fiber can increase the maximum dry density of salt-affected soil. The unconfined compressive strength of the soil with 1% polyester fiber and 8% silica fume reinforcement is the highest, which is 1.98 times that of the original soil. The unconfined compressive strength of the soil with 1% polyester fiber reinforcement is the largest, 1.43 times that of the original soil. The unconfined compressive strength of the soil with 5% and 7% glass fiber reinforcement is relatively large, 1.56 and 1.57 times that of the original soil, respectively. The cohesion of the original soil is the largest. The internal friction angle of the soil with 6% glass fiber reinforcement is the largest. In addition, the addition of synthetic fibers can significantly reduce the dissolution coefficient of salt-affected soil, especially glass fibers. Through SEM and NMR analysis, it is found that fibers form a good clamping action with soil particles, and some fibers have a tight bond with the soil, reducing the porosity of the soil.
Decomposition of Au<i>n</i>O− clusters into gold oxide and metallic components: Unraveling the impact of single-atom oxygen on the reactivity modulation
Gold clusters serve as ideal models for probing chemical bonding theories and their reactions with O2 provide valuable insights into the O2 activation mechanisms on gold-based catalysts. While extensive research has been conducted on pristine gold clusters, investigations into the reactivity of nonmetal-doped gold clusters remain limited. Here, we explore the reactions of AunO− (n = 5–20) with O2 using cluster reaction experiments and density functional theory calculations, and our findings reveal that many AunO− exhibits a structure–activity relationship different from those of pure gold clusters and small gold oxide clusters. In these AunO−, the oxygen atom bonds with two or three adjacent gold atoms, creating a metal oxide unit, while the remaining gold atoms constitute a metallic component. The reactivity of these AunO− is predominantly dictated by its metallic part, which is affected by the ease of electron transfer to O2. The decomposition of these AunO− into oxide and metallic components aligns with the strategy of partitioning ligand-protected noble metal clusters into a covalent outer shell and a metallic core and also enriches the emerging framework of the superatomic molecule concept in cluster science. Moreover, these insights offer valuable clues for understanding the behavior of gold clusters supported on oxide surfaces.
Efficient federated learning via aggregation of base models
Federated Learning (FL), as a distributed computing framework for training machine learning (ML) models, has garnered significant attention for its superior privacy protection. In typical FL, a subset of client models is randomly selected for aggregation in each iteration, which performs well when the data is independent and identically distributed (IID). However, in real-world scenarios, data is often non-independent and identically distributed (Non-IID). Random selection cannot capture knowledge from different data distributions, resulting in a global model with lower accuracy and slower convergence. To address this challenge, we propose base models, which are models with diverse data distributions on clients. By combining the parameters of these base models, we can approximate all client models. Meanwhile, we sufficiently demonstrate the existence of base models. Then we employ the evolutionary algorithm (EA) to identify base models on distributed clients by encoding client IDs and optimizing client selection through crossover, mutation, and other evolutionary operations. Our method addresses the issue of low efficiency in random selection. We conduct experiments on the FashionMNIST, MNIST, and TodayNews datasets, applying the proposed method to FL frameworks such as FedAvg, FedProx, and SCAFFOLD, all of which show superior performance and faster convergence.
Polydisperse polymers near a solid surface: Analytical mean-field theory
A linearized mean-field theory is presented, which provides algebraic expressions for the segment density profiles and surface tension of polydisperse polymers near a flat surface. The main finding is that surface properties of polydisperse polymers in solution are well-described by the average degree of polymerization N̄, independent of the shape or variance σ2 of the chain length distribution. Polymers with longer chain lengths are found to preferentially adsorb at the surface in the weak adsorption regime. Analytical expressions are derived for the adsorbed amount and surface tension. The results are in quantitative agreement with numerical self-consistent field computations, as long as the ratio σ2/N̄3 is small compared to the static structure factor of Gaussian chains. The analytical expressions are shown to be valid for polymer solutions and for polymer melts. For the case of polymer melts, we show that our theoretical predictions are in agreement with experimental results.
Inhibitory control impairments underlie associative memory deficits in posttraumatic stress disorder
Objective Posttraumatic-stress disorder (PTSD) patients suffer from cognitive dysfunction and show impairments even in non-trauma-related memory. Research has focused on the relationship between associative-memory and PTSD severity due to patients’ tendency to over-generalize from traumatic cues to neutral ones, leading to escalation of traumatic symptoms. In this study we aim to test to what extent inhibitory control impairments are correlated to associative-memory deficits in PTSD. Method Twenty PTSD and 22 control participants were included. Posttraumatic symptoms were assessed via a board-qualified psychiatrist and the Post-Traumatic Diagnostic Scale. Inhibitory abilities were evaluated using the anti-saccade task and memory performance was probed using a words/pictures item-association paradigm. Results Generally, PTSD patients performed lower than controls in both tasks. Lower associative-memory performance was observed in posttraumatic patients and was attributed to increased false-alarm rate in this group. In addition, we observed a strong significant positive correlation between associative pictorial memory performance and inhibitory performance, and in accordance, a significant negative correlation between the number of false-alarm responses in the associative pictorial test and inhibitory performance in the PTSD group. Conclusions These results support the hypothesis that inhibitory control impairments are associated with (pictorial) associative-memory deficits in PTSD.
Author Correction: Human HDAC6 senses valine abundancy to regulate DNA damage
Vibrational mode-specific dynamics of the Cl + CH3CN reaction
Understanding the vibrational mode-specific dynamics of chemical reactions is crucial for unraveling the fundamental mechanisms that govern reactivity and product formation. In this study, we investigate the Cl + CH3CN reaction using quasi-classical trajectory simulations on a previously developed, high-quality, full-dimensional potential energy surface. By selectively exciting individual vibrational modes of the CH3CN reactant, we systematically analyze their influence on reaction probabilities and cross sections and, in the case of the major H-abstraction channel, on scattering and attack angle distributions, as well as product energy partitioning across a range of collision energies. Furthermore, a vibrational mode-specific product analysis, combined with energy-based Gaussian binning, was conducted to examine how initial mode excitation influences product state distributions. Our results reveal that excitation of specific reactant vibrational modes can enhance the H-abstraction probability without altering the overall reaction mechanism. A significant portion of the initial vibrational energy is transferred to the internal energy of the products, while the collision energy primarily contributes to their translational energy. The CH2CN product exhibits well-defined, mode-specific vibrational excitation patterns, reflecting distinct energy redistribution pathways during the reaction. These findings provide deeper insight into the role of vibrational energy in promoting or altering chemical reaction pathways in a polyatomic system.
Transcriptome profiling and weighted gene co-expression network analysis reveal changes of hub genes and molecular pathways in rat lungs following deep hypothermic circulatory arrest
Background The incidence of acute lung injury (ALI) following aortic dissection repair surgery that involves deep hypothermic circulatory arrest (DHCA) is notably high. We analyzed hub genes and signaling pathways in rat lung tissues post-DHCA using transcriptome sequencing and weighted gene co-expression network analysis (WGCNA). Methods A rat model of DHCA was established, and lung tissues were collected after the procedure. High-throughput transcriptome sequencing was employed to assess gene expression differences between the DHCA group and the non-DHCA group. The DESeq2 method was utilized to analyze differentially expressed genes (DEGs) between these two groups, with further screening for hub genes and their upstream molecules conducted using WGCNA, protein-protein interaction (PPI) networks, and the iRegulon plugin. Biological functions of hub genes were examined via Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. The changes in mRNA and protein levels of hub genes across both groups were evaluated through experimental verification. Results A total of 438 DEGs were identified when comparing the DHCA group to the control group. WGCNA further revealed 197 key genes. Subsequent PPI analysis led to the identification of eight hub genes: FOS, FOSB, JUN, EGR1, ATF3, NR4A1, CCN1, and ZFP36. The hub genes were primarily associated with inflammation, cell apoptosis, and cellular immune responses. ATF3 and SRF may serve as potential upstream regulators. The experimental findings further corroborated that substantial alterations took place in these hub genes, accompanied by significant injury of lung tissue during DHCA. Conclusion DHCA significantly altered gene expression patterns in rat lung tissues. The identified hub genes and signaling pathways related to inflammation and apoptosis may serve as potential therapeutic targets for lung injury following DHCA.
Thermally modulated triplet–triplet annihilation: Deciphering the temperature dependence of upconversion dynamics
The quantum efficiency ceiling of triplet–triplet annihilation upconversion is intrinsically governed by the spin statistical factor (f), yet the physical origin of its anomalously elevated values (f &gt; 0.6) remains a subject of intense debate. By conducting systematic variable-temperature kinetic studies, integrating time-resolved transient absorption spectroscopy with steady-state fluorescence spectral analysis, we elucidated the temperature-dependent reaction dynamics of the benchmark PtOEP/DPA system to investigate the interaction between f and high-energy excited-state (T2) decay pathways. Notably, the positive temperature dependence of f (rising from 0.575 at 190 K to 0.808 at 280 K) and a small activation energy (Ea = 1.92 kJ/mol) demonstrated the dominance of a direct 3(AA)* → S1 reverse intersystem crossing (RISC) mechanism while excluding the hypothesized 3(AA)* → T2 → S1 cascade. These results not only resolve longstanding debates concerning f-enhancement but also provide a rationale for designing annihilators that exploit low-barrier RISC pathways to circumvent spin-statistical constraints.
Optimizing mild surface cleaning methods: influence of water purity and pH
Abstract Due to growing concerns about the environmental impact of detergents, there has been a notable shift towards researching eco-friendly washing methods, such as using purified water for washing and cleaning. It has been shown that purified water can remove olive oil from hydrophilic surfaces but removing it from hydrophobic surfaces is still a challenge. In this work we studied the removal of olive oil from hydrophobic and hydrophilic surfaces using different water alkalinity, different salt solutions, multiple washing cycles and temperatures. For the hydrophobic surface, gravimetric analysis data demonstrated that non-purified water grades can outperform purified ones, but this effect is due to slight variations of pH. Increasing the pH of purified water by addition of tiny amounts of NaOH (that would not have any environmental impact) significantly enhances cleaning efficiency. For the hydrophilic surfaces, water with increased alkalinity completely removes the oil from the surface in most cases. The study reveals that adjusted pH of otherwise pure water promotes deprotonation of fatty acids in olive oil and facilitates oil removal from surfaces through roll up and interfacial tension reduction mechanisms. Increased temperatures further improve cleaning efficiency. These findings highlight the potential of pH-adjusted purified water as an effective and eco-friendly alternative to conventional cleaning methods. Future research should explore similar techniques on complex materials such as textiles.
Association between sleep and physical activity data, and depressive symptoms in Thai elderly
Background Geriatric depression often goes unnoticed due to recall bias and overlapping symptoms with normal aging by using questionnaire screening tool. Consequently, this study aims to explore the associations between passive sensing parameters, such as physical activity and sleep characteristics collected from smart devices, and depression screening scores, aiming to validate its efficacy as a detection tool for the Thai elderly. Methods The prospective cohort study was conducted from July to September 2023. One hundred and seventy-seven elderly individuals were purposefully selected from the main districts of each province across five regions in Thailand. Inclusion criteria required participants to be aged 60 years or older, socially active, and free from diagnoses of cognitive impairment and mental health disorders. Participants were required to wear an Actigraph wGT3X-BT collecting data on physical activity and sleep characteristics. The Patient Health Questionnaire (PHQ-9) was used to screen for depression every two weeks. Univariate and multivariate regression analyses were performed to identify association between passive sensing parameters and PHQ-9. Results There is an association between physical activity parameters and depression score. A One- unit increase in Vector Magnitude in Counts per Minute (VM CPM) and step count, PHQ-9 score would be statistically significant reduced by 0.001 and 0.00007 to 0.00008 score over both two-week periods (p-value <0.1). Only Wakefulness After Sleep Onset (WASO) of all sleep variables showed an association with PHQ-9 in univariate analysis but it did not show further relationship after adjusting with baseline PHQ-9 score and other confounders. In addition, participants who lived outside Bangkok and being younger were more likely to have lower PHQ-9 score. Conclusion There is a potential to apply passive sensing data in mental health issues in Thailand. However, more evidence is needed to ensure the accuracy of sensor detection and appropriate algorithm to predict depression. Moreover, the implication of passive sensing data from smart devices supporting public health policy should be explored.
Elucidating ion capture and transport mechanisms of Preyssler anions in aqueous solutions using biased MACE-accelerated MD simulations
Equilibrium and biased multi-atomic cluster expansion (MACE) accelerated molecular dynamics (MD) simulations in aqueous solutions are performed to investigate the ion capture and transport mechanisms of the {P5W30} Preyssler anion (PA) as the smallest representative member of the extended polyoxometalate (POM) family with an internal cavity. The unique interatomic interactions present in the internal cavity vs the exterior of PA are carefully investigated using equilibrium MACE MD simulations for two representative Na(H2O)@PA and Na@PA complexes in aqueous solutions. Our careful analyses of radial distribution functions and coordination numbers show that the presence of confined water in Na(H2O)@PA has profound modulating effects on the nature of the interactions of the encapsulated ion with the oxygens of the PA cavity. Using well-converged MACE-accelerated multiple walker well-tempered metadynamics simulations with nanosecond timescales, two different associative (ion exchange) and dissociative (ion ejection) ion transport mechanisms were carefully investigated for Na+ as one of the most abundant and representative ions present in seawater and saline solutions. By comparing systems with and without confined water, it was found that the presence of only one pre-encapsulated confined water in Na(H2O)@PA dramatically changes the free energy landscape of ion transport processes. It was also found that the contraction and dilation of the two windows present in PA directly influence the Na+ and H2O transport. The results from this work are helpful, as they show a viable path toward tuning the ion exchange and transport phenomena in aqueous solutions of POM molecular clusters and frameworks.
Inequity in the transmission of malaria infection among children and adolescents: a cohort study in rural Guinea
Abstract Malaria remains a major health concern in rural Guinea, where children face fivefold higher infection risk compared to urban areas. While disparities between rural and urban regions have been documented, inequities within rural areas remain unexplored. Socioeconomic factors influence malaria risk, which varies according to season. Understanding seasonal variations in socioeconomic factors is crucial for developing equitable and targeted interventions. This cohort study was conducted in Mafèrinyah, Guinea, with participants aged 1–19 years of age. Data were collected through monthly home visits over nine months, capturing malaria infection (via blood smears), sociodemographic factors, and household characteristics. Equity analysis was guided by the PROGRESS (place of residence, race/ethnicity/culture/language, occupation, gender/sex, religion, education, socioeconomic status, and social capital) framework. Statistical analyses included concentration index (CI) calculations to assess socioeconomic-related inequality across dry and rainy seasons, binary mixed-effects logistic, and decomposition of CI to identify contributing factors. Malaria infection varies according to season, age, and household characteristics. Children in households with older heads (50–77 years) had higher malaria odds during the dry season (OR = 3.44), whereas adolescents in the rainy season were more vulnerable in middle-aged-headed (OR = 15.78) and single-parent households (OR = 4.52). Concentration indices showed modest pro-rich inequity among adolescents in both seasons (CI = 0.059–0.085) and mixed patterns among children. Among children, secondary education (246.8%) and older age of household head yield strong malaria prevention dividends, but these benefits are currently captured by the better off, while primary education had strong pro-poor effects (among poorer households whose heads had only primary education). Among adolescents, middle-aged heads and older heads (− 419.3%), and unemployment (− 184.2%) reduced inequity. Male-headed households reversed roles by season, contributing − 67.2% to inequity in the dry season and + 19.5% in the rainy season. This study revealed significant seasonal and socioeconomic disparities in malaria transmission among children and adolescents in rural Guinea. Key equity drivers include the household head’s age, education, gender, and occupation, which have distinct seasonal effects. These findings highlight the need for targeted, equity-sensitive interventions that address structural vulnerabilities and seasonal dynamics to reduce the malaria burden and promote health equity.
Perceptions of influenza and SARS-CoV-2 vaccination among health care personnel in Thailand, 2024
Background Influenza and COVID-19 vaccinations are recommended for health care personnel (HCP) in Thailand, but uptake depends on HCP perceptions and motivations. Methods To assess factors associated with self-reported influenza vaccination in the most recent season and intention to receive future COVID-19 vaccination annually, HCP from 16 hospitals across eight Thailand provinces were surveyed during December 2023 through January 2024. Additional survey variables included demographic and occupational characteristics, prior experiences with vaccination, perceptions of disease severity and vaccine safety and effectiveness. Multilevel mixed effect multivariable logistic regression was used, accounting for variability at provincial and hospital levels. Results Overall, 2,180 HCP were surveyed. Three-quarters (74.8%) reported influenza vaccination in the most recent season, and 58.1% intended to receive COVID-19 vaccination annually in the future. Previous influenza vaccination was strongly associated with reported vaccination in the current season (adjusted odds ratio [aOR] 2.94, 95% confidence interval [CI] 2.68–3.23). For future COVID-19 vaccination, perceived vaccine safety was strongly associated (aOR 3.49, 95% CI 3.18–3.84). Perceived disease severity was higher for COVID-19 than for influenza, but perceived vaccine safety and effectiveness were higher for influenza than for COVID-19. The most common barrier to influenza vaccination was insufficient time to get vaccinated (23.7%); whereas the most common barrier for COVID-19 vaccination was vaccine safety concern (30.0%). Conclusions Improving vaccination coverage among HCP might need different approaches for influenza and COVID-19 vaccines. Improving convenience might be especially important for increasing influenza vaccination coverage, whereas providing reassurance about COVID-19 vaccine safety might be especially important for COVID-19.
How to RSoXS
Resonant Soft X-ray Scattering (RSoXS) has emerged as a powerful technique for investigating compositional and orientational heterogeneity in organic thin films. By exploiting the variation in optical constants near atomic absorption edges, RSoXS enables unprecedented contrast between organic materials and unique sensitivity to molecular orientation. Despite its growing importance over the past 15 years, particularly in organic electronics research, detailed guidance on proper implementation and analysis has been limited. This tutorial provides a comprehensive introduction to the technique, starting with the fundamental principles of near edge x-ray absorption fine structure spectroscopy and RSoXS contrast mechanisms. Using multi-walled carbon nanotubes as an illustrative example, we walk through best practices for sample preparation, measurement procedures, and data analysis. We present both model-free analysis approaches and detailed modeling using the open-source NIST RSoXS simulation suite. We intend this tutorial to serve as a practical resource for both new practitioners and experienced researchers, enabling quantitative analysis of molecular-scale structure in soft materials.
N,N-Diethylacetamide and N,N-Dipropylacetamide inhibit the NF-kB pathway in in vitro, ex vivo and in vivo models of inflammation-induced preterm birth
Isolation, biochemical characterization, and greenhouse authentication of chickpea (Cicer arietinum L.) rhizobia collected from some major chickpea growing areas of Woldia, North Wollo, Ethiopia
Chickpea ( Cicer arietinum L. ) is a vital legume crop worldwide, valued for its high nutritional content and significant contribution to food security and soil fertility through biological nitrogen fixation. Despite its importance, chickpea yields remain suboptimal in many regions, including Ethiopia, primarily due to constraints such as poor soil fertility and inadequate use of effective rhizobia inoculants. This study aimed to isolate and characterize native Rhizobium strains from chickpea root nodules collected from fields in the Woldia region and to assess their potential to promote plant growth. A total of 41 bacterial isolates were obtained, of which 12 were presumptively identified as Rhizobium based on growth characteristics on Congo red and bromothymol blue media. These isolates were further characterized morphologically and biochemically. Five biochemically promising isolates were selected for evaluation in a controlled 45-day greenhouse experiment under sterile conditions. Inoculation with these isolates significantly enhanced seed germination and early seedling growth compared to uninoculated controls. The symbiotic effectiveness of the isolates ranged from 74.3% to 121.9%, with isolates WUSFDG-23, WUSFMC-31, and WUSFMC-23 demonstrating high effectiveness, isolate WUSFDG-23 markedly increased nodulation and biomass accumulation. This study highlights the potential of native Rhizobium isolates from Woldia chickpea fields, especially WUSFDG-23, as effective bio-inoculants to promote sustainable chickpea production and reduce dependence on chemical fertilizers.
A direct diabatic states construction method with consistent orbitals for valence and Rydberg states
This work presents a novel methodology termed Direct Diabatic States Construction (DDSC), which integrates fragment wavefunctions into an anti-symmetric wavefunction for the entire system. Using fragment-localized state-consistent molecular orbitals, this approach enables direct construction of all diabatic states at the same root. Each diabatic state is formed as a linear combination of a set of diabatic configurations. The validity and effectiveness of DDSC have been demonstrated through its application to the LiH and (C2H4)2+ molecules. The results show that this method is suitable for constructing both valence and Rydberg diabatic states. One of the key advantages of DDSC is its ability to directly compute diabatic couplings, which can be converted to non-adiabatic coupling vectors along the reaction coordinate. The DDSC method efficiently builds the diabatic potential energy matrix, especially for systems with clear fragment partitions and weak inter-fragment interactions, such as charge transfer reactions.