Browse Articles

Experimental and theoretical assessments of an innovative star-shaped polyamine surfactant designed for X-65 steel corrosion mitigation in acidic environment

Abstract The extant study introduces newly fabricated star-shaped polyamine surfactant ( PAS ) as a highly effective corrosion inhibitor for carbon steel ( X-65 ) in 1.0 M HCl environment. The PAS was synthesized by reaction of dodecyl amine with maleic anhydride via ring-opening reaction forming a monomaleate amide that was esterified with triethanolamine to yield a star-shaped structure, followed by Michael addition reaction using diethylenetriamine. The chemical structures of PAS were confirmed by FT-IR and 1 HNMR. Surface tension measurements were employed to quantify the key surface properties of PAS . The inhibition performance was comprehensively evaluated through electrochemical techniques, surface characterization, and theoretical computations. Electrochemical impedance spectroscopy ( EIS ) revealed an exceptional inhibition efficiency of ~ 96% at an optimal concentration of 1000 µM, with the charge transfer resistance increasing significantly to 348.56 Ω cm 2 . Potentiodynamic polarization ( PDP ) measurements demonstrated that PAS operated as a mixed-type inhibitor through suppressing both anodic and cathodic reactions. The inhibition mechanism was governed by the spontaneous adsorption of PAS molecules onto the X-65 surface, which follows the Langmuir adsorption isotherm suggesting a combination of physical and chemical adsorption. Surface morphology analysis utilizing scanning electron microscopy ( SEM ), energy-dispersive X-ray spectroscopy ( EDX ), and atomic force microscopy ( AFM ) provided direct evidence of the protective adsorbed film of PAS . Furthermore, theoretical assessments using density functional theory ( DFT ), and Monte Carlo simulations ( MCs ) successfully predicted the PAS active sites and its strong adsorption affinity onto the Fe surface, corroborating the experimental findings.

Exploring the response of photoswitchable polymer networks by atomistic simulations

Light-responsive polymers containing molecular photoswitches are promising candidates for the development of smart materials. Here, we investigate the precise nature of the response of a cross-linked azopolymer network depending on the length of spacer groups between the cross-linkers, the solvent, and the thickness of the polymer film. To this end, we develop an efficient and accurate atomistic force field that is able to describe not only the electronic ground state but also the photoisomerization of the azobenzene units via electronic excitation. Molecular dynamics simulations are performed by photoswitching different percentages of azo-units from trans to cis, yielding a reduction of polymer volume by up to 40 % for the initial photoirradiation. Repeated trans → cis and cis → trans photoswitching leads to a “collapsed” state of the polymer network that exhibits a weak and non-systematic photoresponse. This behavior is largely independent of solvent polarity, as it is seen to occur in water, ethanol, and benzene alike. The reversibility of the light-induced contraction/expansion of the polymer in polar solvents is considerably enhanced upon removing the alkyl spacer chains. Counterintuitively, however, the polymer volume in water is larger for the cis-state compared to the trans-state. For a densely stacked system of 2D polymer networks, no clear difference between the volumes in the two isomeric states is discernible. Increasing the stiffness of the torsional degree of freedom adjacent to the cross-linker produces the desired reversible contraction/expansion upon photoswitching.

Multimorbidity trajectories and their sex-specific impacts on risk of mortality and re-hospitalisation

Abstract The clinical presentation of disease is complicated by multimorbidity, underscoring the need to clarify its effects and identify intervention targets. Using whole UK Biobank hospital inpatient data, we performed the first comprehensive, sex-stratified analysis of age- and morbidity-adjusted mortality and re-hospitalisation outcomes of multimorbidity accrual, both total and specific historical diagnoses, for a range of presenting diagnoses. One-year mortality and re-hospitalisation risks associated with the presenting total accrued multimorbidity of an individual varied markedly with the presenting diagnosis, ranging from no effect to a 1.58-fold increase per diagnosis, highlighting strong context-dependent risks of multimorbidity accrual. Sex disparities in these context-dependent effects were greater for re-hospitalisation than mortality risk. Identification and risk-modelling of non-random trajectories of specific diagnoses revealed especially high-risk multimorbidity (1.16-16.18 fold resultant increases in 1-year mortality/re-hospitalisation) with predictable orders of presentation, suggesting potential points of focused intervention. Notably, a history of diagnosed substance use in males markedly amplified mortality and re-hospitalisation rates, particularly in presentations of anaemias and infections, as did cardiometabolic histories in men presenting with certain digestive diseases.

Deep learning of committor for ion dissociation and interpretable analysis of solvent effects using atom-centered symmetry functions

The association and dissociation of ion pairs in water are fundamental to physical chemistry, yet their reaction coordinates are complex, involving not only interionic distance but also solvent-mediated hydration structures. These processes are often represented by free-energy landscapes constructed from collective variables (CVs), such as interionic distance and water-bridging structures; however, it remains uncertain whether such representations reliably capture the transition pathways between the associated and dissociated states. In this study, we employ deep learning to identify reaction coordinates for NaCl ion pair association and dissociation in water, using the committor as a quantitative measure of progress along the transition pathway through the transition state. The solvent environment surrounding the ions is encoded through descriptors based on atom-centered symmetry functions (ACSFs), which serve as input variables for the neural network. In addition, SHapley Additive exPlanations analysis, as an explainable artificial intelligence technique, is applied to identify ACSFs that contribute to the reaction coordinate. A comparative analysis of their correlation with CVs representing water-bridging structures, such as interionic water density and the number of water molecules coordinating both ions, further provides a molecular-level interpretation of the ion association–dissociation mechanism in water.

Mapping partial agonism of mitragynine at the µ-opioid receptor through molecular dynamics and Markov state modelling analysis

Computational dielectric spectroscopy shows that water/methanol mixtures form hybrid hydrogen bonding networks

Methanol/water mixtures are miscible across the entire composition range, despite having vastly different hydrogen bonding superstructures. The exact nature of the hydrogen bonding structure in these mixtures has been debated. Dielectric spectroscopy can be used to probe whether the collective reorientation of the hydrogen-bonding superstructure has timescales associated with methanol and water separately or a single relaxation, indicating a hybrid structure. Through analysis of the component spectra, we find only one relaxation accounting for all hydrogen-bonding structure reorientations across the entire composition range, indicating that a hybrid hydrogen bonding structure is indeed formed across that entire range.

High-yield induced ovulation in the adult marsupial fat-tailed dunnart (Sminthopsis crassicaudata)

Thermodynamically consistent incorporation of the Langmuir adsorption model into compressible fluctuating hydrodynamics

For a gas–solid interfacial system where chemical species undergo reversible adsorption, we develop a mesoscopic stochastic modeling method that simulates both gas-phase hydrodynamics and surface coverage dynamics by coupling the Langmuir adsorption model with compressible fluctuating hydrodynamics. To this end, we derive a thermodynamically consistent mass–energy update scheme that accounts for how the mass and energy variables in the gas and surface subsystems should be updated according to the changes in the number of molecules of each species in each subsystem due to adsorption and desorption events. By performing a stochastic analysis for the ideal Langmuir model and the full hydrodynamic system, we analytically confirm that our mass–energy update scheme captures thermodynamic equilibrium predicted by equilibrium statistical mechanics. We find that an internal energy correction term is needed, which is attributed to the difference in the mean kinetic energy of gas molecules colliding with the surface from that computed from the Maxwell–Boltzmann distribution. By performing an equilibrium simulation study for an ideal gas mixture of CO and Ar, with CO undergoing reversible adsorption, we validate our overall simulation method and implementation.

Circulating levels of high mobility group box-1 and nucleophosmin/B23 proteins and clinical significance in debut non-small cell lung cancer patients

Simultaneous improvement of glass transition temperature and dielectric properties of epoxy resin through novel curing agent molecular designs

With the development of third-generation SiC semiconductor power devices, the thermal resistance and dielectric properties of traditional epoxy resins can no longer meet the demands of high-temperature and high-voltage operating environments. To solve this problem, a novel epoxy resin curing agent was designed in this study. Diaminodiphenyl sulfone (DDS) was used as the raw material; a substitution reaction was carried out with a trifluoromethylating electrophilic reagent [1-trifluoromethyl-1,2-benzoxazol-3(1H)-one] to obtain the novel epoxy curing agent (DDS-CF3). After curing, a highly cross-linked epoxy resin having a glass transition temperature of 312.5 °C and an AC breakdown field strength of 144.3 kV/mm was obtained. The epoxy resin maintained a low dielectric constant and low loss characteristics within the frequency range of 101–106 Hz, demonstrating excellent potential as an insulating material for semiconductor power device packaging.

Secure quantum-resilient smart city communication networks using QSC-Net with MF-MBO-based energy-aware task scheduling

Co-designed principles for establishment of a virtual hospital

Interfacial engineering of aluminum powder with a tannic acid/Fe³⁺ complex and fluorosilane for high-performance energetic composites

Allergy-associated acute coronary syndrome without anaphylaxis in a prospective observational study

Abstract Kounis syndrome is an acute coronary syndrome (ACS) triggered by allergic reactions via mast cell activation, classically accompanied by anaphylaxis. However, ACS associated with mild or subclinical allergic reactions may be underrecognized. We investigated immune markers and autonomic nervous system activity in patients with ACS and characterized allergy-associated ACS without anaphylactic symptoms. Among 375 patients treated for ACS (April 2022 to March 2024), 49 were prospectively enrolled. Patients were classified into non-allergy-associated ACS (ACS-NA, n = 32) and allergy-associated ACS (ACS-AL, n = 17) groups. ACS-AL was subdivided into the non-anaphylactic (ACS-AL(nonA), n = 11) and anaphylactic (ACS-AL(withA), n = 6) groups. Allergic status was comprehensively assessed. Serum IgE and plasma histamine were measured at ACS onset. Heart rate variability (HRV) parameters were analyzed using 24-h ambulatory monitoring within 1 week after percutaneous coronary intervention. The ACS-AL(nonA) and ACS-AL(withA) groups showed significantly higher IgE and histamine levels than the ACS-NA group (P < 0.05), with overlapping distributions. HRV analysis revealed elevated LF/HF ratios and reduced daytime HF in both groups, indicating sympathetic predominance. ACS-AL, even without anaphylaxis, involves immune activation and autonomic imbalance. Combined assessment of IgE, histamine, and HRV may improve the identification of this phenotype.

Research on agricultural development issues based on comprehensive optimization strategy

Long period quakes linked to Mefite D’Ansanto (Italy) mantellic CO2 emissions

Trimester-specific lipid profile reference intervals in healthy pregnant women; A cross-sectional study at Debre Markos comprehensive specialized hospital, 2022/2023

A unified Haar wavelet collocation framework for fractional volterra integro-differential equations with application to tumor-immune dynamics modeling

Integrated GRM-based efficient multi-performance prediction method for reconfigurable Fabry–Perot antennas

Dissemination of vancomycin-resistant Enterococcus faecalis and Enterococcus faecium between humans and fishes

Abstract Vancomycin-resistant enterococci (VRE) are a major public health concern, yet little is known about their circulation in fish. This study investigated the occurrence, glycopeptide resistance genotypes, virulence characteristics, and sequence types (STs) of VRE isolated from diseased fishes and humans. Isolates were identified using multiplex polymerase chain reaction (PCR) assay and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and tested for antimicrobial susceptibility. VRE isolates were screened for the presence of glycopeptide resistance genes and eight virulence genes. Multilocus sequence typing (MLST) was determined to assess the clonality of VRE isolates from fishes and humans. Among 60 human samples, 20 Enterococcus species isolates (33.33%) including Enterococcus faecalis and Enterococcus faecium (10 of each), were identified. The overall prevalence of E. faecalis was 42.86% (30/70) in Oreochromis niloticus and 48.0% (24/50) in Clarias gariepinus . E. faecium was found in 15.71% (11/70) of Oreochromis niloticus and 14.0% (7/50) of Clarias gariepinus . Over 50% of human isolates were multidrug resistant (MDR) and 30% exhibited an extensive drug resistant (XDR) phenotype. Fish isolates also displayed high MDR (70.83%) and XDR (29.17%) rates. Forty-nine (53.26%; 34 from fish and 15 from human) isolates were VRE including 30 isolates of E. faecalis (VREfs) and 19 isolates of E. faecium (VREfm). The vanA gene was the most frequent among VREfs (83.33%) and VREfm (100%) isolates. The vanB gene was found in 26.67% of VREfs and 15.79% of VREfm. Three out of 10 VREfm (30%) and 2/24 (8.33%) VREfs isolates of fish origin carried both vanA and vanB genes. vanC gene was found in 13.33% (4/30) of VREfs of human and fish origin. One VREfs isolate from human urine carried both vanA and vanC genes. High frequency of the virulence genes  gelE , sprE , asa1 , esp, and cylA were observed;  efa  and ace gene was more associated with VREfs, while hyl  gene was more frequently detected in VREfm. Different combinations of virulence genes suggesting synergistic pathogenic potential. MLST revealed both overlapping and host-specific STs among the examined Enterococcus isolates from humans and fish. Experimental infection of O. niloticus with VREfs and VREfm caused a 100% and 60% mortality rate within 6 days postinfection, respectively with characteristic disease symptoms. The emergence of VRE and the high prevalence of virulence traits could be regarded as an alarming situation. The call for increased infection control and antibiotic stewardship measures is timely and relevant to combat the spread of VRE in fish and humans.