Browse Articles

Investigating the relationship between sleep quality and parental bonding patterns with aggression among adolescents in the City of Bushehr

Improving interfacial thermal conductivity by constructing covalent bond between Ga₂O₃ and SiC

Optimization of cementitious and fine electric arc furnace slag on the concrete mixes through mechanical, durability, and microstructural testing

Application of statistical design of experiment to identify key factors in cross coupling reactions

Household exposure, demographic and health characteristics associated with SARS-CoV-2 infection in a cohort study in Northern France

Abstract In this cohort study, we aimed to study the risk of SARS-CoV-2 infection and its association with household exposure, as well as demographic and health factors. Between March 2020 and April 2022, we conducted a cohort study among adults and children aged 5 years or more in a town in northern France. Participants were screened repeatedly for post-infection anti-SARS-CoV-2 immunity. Infection dates were inferred in hierarchical order from symptomatic episodes or virological tests, or if unavailable from the timing of other cases in the household or the window of seroconversion. Household exposure to a case of SARS-CoV-2 during the infectious phase was defined as a time-varying exposure. We included 830 participants with a mean follow-up of 453 days (12,353 total person-months), during which we identified 491 infections (incidence rate 39.7 per 1,000 person-months). In adjusted analyses, exposure in the household to an infected individual was associated with an incidence rate ratio (IRR) of 16.48 (95% CI 12.29–22.09), and baseline statin use was associated with a decreased risk of infection (IRR 0.35, 95% CI 0.13–0.89). These results could contribute to the development of additional prophylactic strategies, e.g., post-exposure, for the population at high risk of severe forms of COVID-19.

Indirect communication between non-Markovian baths

In this work, we show that information transfer occurs between two baths, even in the absence of a direct coupling between the baths. This bath–system–bath-mediated information transfer leads to intricate non-Markovian dynamics in the open system considered. We show this through the development of a model for an undamped vibration in the presence of an overdamped bath. This two-bath model involves a new derivation of the hierarchical equations of motion (HEOM) for an overdamped Lorentz–Drude (LD) environment, which is combined with an undamped oscillator (UO) bath, termed LDUO-HEOM. The model is analyzed using expectation values of the bath coordinates, which demonstrates an approach to understanding dissipation and relaxation between multiple, coupled baths. The model generates 2D electronic spectra that are in qualitative agreement with single-bath models while eliminating additional superfluous damping, which was introduced by the finite spectral width of the underdamped bath in our previous two-bath underdamped–overdamped, “bath vibration model” [Humphries et al., J. Chem. Phys. 156, 084103 (2022)].

Simplified monitoring of sofosbuvir/velpatasvir in Japanese patients with chronic hepatitis C based on a retrospective analysis of a prospective multicenter cohort

Graph-based block-diagonalization of full configuration interaction Hamiltonian

We developed a graph-based block-diagonalization (GBBD) method for the full configuration interaction (FCI) Hamiltonian of molecular systems to efficiently calculate the exact eigenvalues of low-energy states. In this approach, the non-zero matrix elements of the Hamiltonian are represented as edges on a graph, which naturally decomposes into disconnected clusters. Each cluster corresponds to an independent block in the block-diagonalized form of the Hamiltonian. The eigenvalues in the low-energy sector were obtained by solving the eigenvalue problem for each block matrix and by solving a modified Hamiltonian subject to orthonormality constraints with respect to previously computed lower-energy eigenstates. An advantage of our method is that, compared to the conventional FCI approach, it can rapidly compute the low-lying eigenvalues and eigenvectors through graph analysis while saving memory and without the need to compute all edges. We applied the GBBD method to linear hydrogen H chains and the N2 molecule. The results showed excellent agreement with the exact ones, confirming both the accuracy and efficiency of the proposed method. Finally, we discussed several physical properties in relation to the number of H2 chains and for the N2 molecule.

The association between cerebral blood flow and standing dual task performance is dependent upon age group and cognitive load

Thermal boundary conductance at the myoglobin–water interface: Heme cooling mechanism in light and heavy water environments

The molecular mechanism of heme cooling following the photoexcitation of heme proteins has been a central issue in biological chemical physics for several decades. We expect that such a non-equilibrium process is accompanied by a vibrational energy relaxation from one site (protein quake epicenter) to the other sites in the protein molecule and eventually to the solvent molecules surrounding the protein. Interestingly, a recent optical-pump THz-probe spectroscopy demonstrated that the energy dissipation rate from the photoexcited heme of myoglobin in the D2O environment was slower than that in H2O, the mechanism of which remains unclear. To address the issue, we investigated the energy dissipation mechanism at the myoglobin–water interface with a special emphasis on the roles of the heme propionate side chains. After performing the equilibrium molecular dynamics simulation of myoglobin in both D2O and H2O environments, we calculated the vibrational density of states, from which we evaluated the solvent substitution effect on the heme side chain dynamics. In addition, the structure of the solvation shell around each heme side chain was examined using the radial distribution function of waters. Furthermore, we estimated the thermal boundary conductance at the myoglobin–water interface and discussed the heme cooling mechanism by exploiting a thermal RC circuit model for the protein–water interface. The calculated value of the thermal boundary conductance of the myoglobin–water interface was larger in H2O than that in D2O, in line with the experimental observation. Furthermore, we estimated the thermal relaxation time at the myoglobin–water interface based on the thermal RC circuit model.

Spatiotemporal analysis of Escherichia coli membrane permeabilization and uptake kinetics induced by a single microbubble cavitation event

Abstract A single cavitation microbubble can transiently disrupt the cellular membrane, providing a chemical-free, targeted drug delivery mechanism. Here, we investigate the spatiotemporal dynamics of membrane permeabilization in an Escherichia coli ( E. coli ) monolayer exposed to a single cavitation event. Using high-resolution fluorescence microscopy and propidium iodide (PI) uptake as a marker of membrane disruption, we tracked the response of 5565 individual cells around the center of the cavitation event over timescales from microseconds to minutes and spatial scales from 1 to 165 µm. PI uptake rates exhibited a strong spatial dependence, with cells closer to the cavitation center showing rapid and extensive permeabilization. A modified Goldman equation describing PI concentrations inside and outside the cells was used and related to the spatiotemporal measurements of fluorescence intensity. The model accurately captured the first-order PI uptake kinetics, which resulted in saturated fluorescence intensity profiles. Additionally, the model predicted an exponential decay of permeability post-cavitation, implicitly suggesting that pore-resealing dynamics were taking place. Membrane permeability decreased with distance as 1/r, with a characteristic decay time of approximately 3.4 min. Our model thus predicts cell damage induced by a single cavitation event in both space and time. In the present case, where the cavitation bubble reached maximum radius of 29.7 µm, we found that at a distance of 11 µm from the cavitation center, ~ 50% of cell membranes are damaged and permeable to PI, but a pore-resealing mechanism reduces this damage to ~ 1% after 10 min. Our results are consistent with existing sonoporation studies and offer novel insights for optimizing cavitation-assisted drug delivery and biofilm disruption strategies.

Dynamic heterogeneity and mechanism of ionic transport in NaTFSI-based WiSE and superconcentrated NaTFSI–EmimTFSI hybrid aqueous electrolytes

We investigate the impact of simultaneous addition of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMIMTFSI) ionic liquid and excess NaTFSI salt on the microscopic dynamics and transport properties of NaTFSI-based water-in-salt electrolyte (WiSE). From the analysis of the translational dynamics of the ions, we observe that the Na+ ions are the fastest diffusing ionic species stemming from their longer correlated motion with water molecules in the 8 m WiSE. As observed in experiments, the simulated ionic conductivity of the electrolyte decreases monotonically with increasing overall concentration of the electrolyte from 8 to 80 m by adding EMIMTFSI and NaTFSI together. The analysis of distinct diffusion coefficients reveals an overall anti-correlated collective motion of both coions and counterions in the WiSE (8 m) and hybrid electrolytes (50 and 80 m). Among these collective motions, the anion–anion (TFSI−–TFSI−) exhibits most pronounced anti-correlated motion. In the hybrid electrolytes, a longer residence time for the Na+ ions in the vicinity of water molecules is observed, signifying the dominance of the vehicular mechanism of Na+ ion conduction. On the other hand, Na+ and EMIM+ cations both adapt structural exchange mechanisms for their conduction when present in close proximity to the TFSI− anions in both WiSE and hybrid electrolytes. The presence of longer average hydrogen bond lifetimes between water molecules reveals stronger hydrogen bonds due to their small cluster-like existence in the hybrid electrolytes. The slower relaxation of the rotational time autocorrelation function for water and the EMIM+ cation with increasing salt concentration implies restriction in their motions due to the surrounding species. Pronounced dynamic heterogeneity in the motion of Na+ ions is observed in the hybrid electrolytes as compared to that in WiSE because of very different solvation environments in their vicinity. A longer correlation timescale for Na+ ions and water molecules is revealed through the analysis of distinct van Hove correlation functions in the hybrid electrolytes.

Innovative cryogenic cooling material using spin frustration from abundant elements

Abstract Cryogenic cooling technology is essential for modern applications, such as magnetic resonance imaging and quantum computing; however, it currently relies heavily on critical resources such as helium and heavy rare-earth elements. As demand for cryogenic cooling increases, developing alternative technologies that reduce reliance on these scarce resources is crucial. This study introduces regenerator materials from abundant elements—copper, iron, and aluminum—that function as Gifford–McMahon (GM) cryocoolers. These materials achieve cryogenic cooling through the spin frustration effect, where competing magnetic interactions enhance magnetic heat capacity. CuFe₁₋ₓAlₓO₂ demonstrates effective cooling capacity at the helium condensation temperature comparable with that of conventional heavy rare-earth-based materials and surpasses the performance specifications of commercial GM cryocoolers. These findings demonstrate the potential of non-rare-earth magnetic materials for sustainable cryogenic technology, reducing dependence on critical resources.

Lifting regenerative barriers promotes epithelial cell fate plasticity supporting lineage conversion

Abstract The ability of adult epithelial cells to rewire their cell fate programme in response to injury has emerged as a new paradigm in stem cell biology. This plasticity supersedes the concept of strict stem cell hierarchies, granting cells access to a wider repertoire of fate choices. Yet, in order to prevent a disordered cellular response, this process must be finely regulated. Here we investigate the little-known regulatory processes that restrict fate permissibility in adult cells, and keep plasticity in check. Using a 3D regenerative culture system, that enables co-culturing epithelium and stroma of different origins, we demonstrate that oesophageal cells exposed to the ectopic signals of the dermis are capable of switching their identity towards skin. Lineage tracing experiments and histological analysis, however, reveal that the oesophageal-to-skin lineage conversion process is highly inefficient, pointing to the existence of barriers limiting cell fate re-specification. Single-cell RNA sequencing capturing the temporality of this process shows that cells transitioning towards skin identity resist the natural progression towards tissue maturation by remaining in a persistent regenerative state marked by a particularly strong hypoxic signature. Gain and loss of function experiments demonstrate that the HIF1a-SOX9 axis acts as a key modulator of epithelial cell fate plasticity, restricting changes in identity during tissue regeneration. Taken together, our results reveal the existence of lineage conversion barriers that must be resolved for cells to respond to signals instructing alternative fate choices, shedding light on the principles underlying the full regenerative capacity of adult epithelial cells.

Performance enhancement of a low-energy humidification dehumidification desalination system using the M-cycle

High-$$T_c$$ superconductivity with quadratic electron-phonon coupling

Ferroelectricity-driven strain-mediated magnetoelectric coupling in two-dimensional multiferroic heterostructure

Thermal–exergetic analysis of hemispherical solar still enhanced with activated carbon nanoparticles synthesized from spent tea dust

Panax notoginseng saponins suppress the PI3K/AKT pathway to enhance autophagy and apoptosis in pulmonary fibrosis

Universal electrochemical quantification of active site density in transition metal nitrogen carbon electrocatalysts

Abstract In-situ electrochemical nitrite reduction is an established method to quantify site density (SD) of platinum-group-metal-free catalysts for PEM fuel cells. However, its poisoning mechanism remains unclear, often yielding underestimated values. Crucially, we identify a unique configuration where single metal centers adsorb two NO molecules, which challenges conventional electrochemical quantification. To resolve this, we developed an in-situ acid-assisted nitrite poisoning method (AANPM) coupled with graphene-based attenuated total reflection Fourier transform infrared spectroscopy (graphene-based in-situ ATR-FTIR). This approach quantifies SD and elucidates active site structures in transition metal-nitrogen-carbon (MNC) electrocatalysts. By incorporating the average electron transfer number for NO electroreduction (NOR), we achieve accurate SD calculations. Validated across iron/cobalt phthalocyanine molecular catalysts and pyrolyzed FeNC/CoNC materials, this method can be used to stablish structure-activity relations.