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Extraction and characterization of phenolic compounds of jujube (Ziziphus jujuba) by innovative techniques
Polymer sailing on rafts within lipid membranes
Understanding the dynamics of macromolecules adsorbed from extracellular fluids onto cell membranes is crucial for elucidating basic cellular processes and advancing applications in biotechnology, such as biosensing, therapeutics, and synthetic biology. However, this is complicated by the interplay between membrane heterogeneity, macromolecule conformation, and fluid hydrodynamics. We investigate the dynamics of linear polymers on binary lipid membranes using hydrodynamics simulations and single-molecule tracking experiments. We find that the preferential adsorption of nanosized polymer onto the raft-forming component of the membrane induces and stabilizes a single lipid raft that colocalizes with the polymer. This lipid raft, in turn, imposes dynamic confinement on the polymer, resulting in swollen yet restricted 2D conformations and Saffman–Delbrück-type diffusivity. These effects lead to an unusual scaling for polymer interfacial diffusion, D ∼ N − ν D with ν D ≈ 0.5 . Normal mode analysis further reveals that the relaxation time of the polymer’s slowest mode surprisingly follows the prediction of Zimm model for a 3D chain in a good solvent, irrespective of whether the polymer’s hydrodynamics are dominated by the 3D solvent or 2D fluid membrane. We also identify two diffusive modes: Saffman–Delbrück-type for polymer on heterogeneous membranes and Stokes–Einstein-like for polymer on homogeneous membranes, demonstrating the potential of polymer adsorbates as biosensors for membrane heterogeneity. Our study provides insights into polymer dynamics on biological membranes and suggests that polymer adsorbates can modulate lipid rafts, influencing raft-related cellular processes.
AI-driven point cloud framework for predicting solder joint reliability using 3D FEA data
Abstract Crack propagation in solder joints remains a major challenge impacting the thermo-mechanical reliability of electronic devices, underscoring the importance of optimizing package and solder pad designs. Traditional Finite Element Analysis (FEA) techniques for predicting solder joint lifespan often rely on manual post-processing to identify high-risk regions for plastic strain accumulation. However, this manual process can fail to detect complex and subtle failure mechanisms and purely based on averaging the creep strain and correlating it to lifetime values collected from experiments using Coffin Manson equation. To address these limitations, this study presents an Artificial Intelligence (AI) framework designed for automated 3D FEA post-processing of surface-mounted devices (SMDs) assembled to Printed Circuit Board (PCB). This framework integrates 3D Convolutional Neural Networks (CNNs) and PointNet architectures to automatically extract complex spatial features from 3D FEA data. These learned features are then linked to experimentally measured solder joint lifetimes through fully connected neural network layers, allowing the model to capture complex and nonlinear failure behaviours. The research specifically targets crack development in solder joints of ceramic-based high-power LED packages used in automotive lighting systems. This dataset included variations in two-pad and three-pad configurations, as well as thin and thick film metallized ceramic substrates. Results from the study demonstrate that the PointNet model outperforms the 3D CNN, achieving a high correlation with experimental data (R 2 = 99.91%). This AI-driven, automated feature extraction approach significantly improves the accuracy and provide the more reliable models for solder joint lifetime predictions, offering a substantial improvement over traditional method.
The transcription factor Bcl11a is essential for B-1a cell maintenance during aging
B-1a cells, a self-renewing B cell subset essential for innate immunity, produce natural IgM antibodies that defend against pathogens, yet mechanisms sustaining their maintenance during aging remain unclear. We report that aging B-1a cells exhibit hallmarks of decline, including DNA damage, apoptosis, and reduced proliferation, with striking sex-specific disparities: aged females retain higher B-1a cell numbers than males, correlating with enhanced glycolysis and chromatin accessibility. Motif analysis of accessible regions identified the transcription factor Bcl11a, which shows elevated chromatin accessibility and expression in aged female B-1a cells but declines in males. Bcl11a deletion reduced B-1a cell numbers, impaired viability, and increased apoptosis across sexes and ages. Mechanistically, Bcl11a sustains survival by upregulating antiapoptotic genes ( Mcl1 , Mdm2 , and Mdm4 ) to suppress p53-mediated apoptosis, as evidenced by partial rescue of viability defects in Bcl11a-deficient B-1a cells upon p53 deletion. Conversely, Bcl11a overexpression or Bcl11a-high B-1a cells from aged Bcl11a -eGFP reporter mice enhanced stress resistance. These findings establish Bcl11a as a key regulator of B-1a cell maintenance during aging and reveal its role in mitigating sex-dimorphic immune decline through transcriptional control of survival pathways.
Three-dimensional flow analysis of penta and ternary-hybrid nanofluids over an elongating sheet with thermal radiation and gyrotactic microorganisms
Daily briefing: Stress can make you sick, and scientists are learning why
TEAD-targeting small molecules induce a cofactor switch to regulate the Hippo pathway
TEAD proteins are the main transcriptional effectors of the Hippo signaling pathway and a clinical-stage pharmacological target in oncology. Most TEAD-targeting small molecules are designed to disrupt interaction between TEAD and the oncogenic transcriptional activators YAP and TAZ. Here, we uncover an alternative mechanism for a subset of TEAD lipid pocket-binding molecules. We report that select sulfonamide-containing TEAD-targeting compounds enhance the interaction between TEAD and the transcriptional repressor VGLL4. Chemically induced VGLL4–TEAD complexes confer an antiproliferative effect by outcompeting YAP–TEAD complexes at chromatin. This cofactor switch from YAP to VGLL4 impacts transcriptional networks, including influencing the expression of genes involved in cellular proliferation and mechanosignaling. We demonstrate that VGLL4 is required for an antiproliferative response to these sulfonamide-containing compounds by counteracting YAP. We show that VGLL4 overexpression can confer sensitivity to these compounds in Hippo-driven cell lines, and we further show that genetic deletion of VGLL4 oblates cellular responsiveness to these molecules in cells and in vivo. Our data reveal a category of TEAD inhibitors that act as “molecular glues” toward the repressive VGLL4–TEAD interaction. These findings open up understandings for curbing the oncogenic activity of Hippo pathway deregulation in cancer, and identify glue-like molecules that promote transcriptional repression.
Quantitative microvessel orientation biomarkers derived from contrast free ultrasound imaging for cancer diagnosis
Regulation of the ordinal DNA translocation cycle in bacteriophage Φ29 through trans-subunit interactions
Certain viruses such as tailed bacteriophages and herpes simplex virus package double-stranded DNA into empty procapsids via powerful, ring-shaped molecular motors. High-resolution structures and force measurements on the DNA packaging motor of bacteriophage Φ29 revealed that its five ATPase subunits coordinate ATP hydrolysis with each other to maintain the proper cyclic sequence of DNA translocation steps about the ring. Here, we explore how the Φ29 motor regulates translocation by timing key events, namely ATP binding/hydrolysis and DNA gripping, through trans-subunit interactions. We used subunit dimers bound to DNA as our model system, a minimal system that still captures the conformation and trans-subunit interactions of the full pentameric motor complex. Molecular dynamics simulations of all-ATP and mixed ATP–ADP dimers revealed that the nucleotide occupancy of one subunit strongly affects the ability to hydrolyze ATP in the adjacent subunit by altering the free energy landscape of its catalytic glutamate approaching the gamma phosphate of ATP. Specifically, one ATP-bound subunit donates residues in trans that sterically block the neighboring subunit’s catalytic glutamate. This steric hindrance is resolved when the first subunit hydrolyzes ATP and is ADP bound. This obstructive mechanism is supported by functional mutagenesis and appears to be conserved across several Φ29 relatives. Mutual information analysis of our simulations revealed intersubunit signaling pathways, via the trans-acting obstructive residues, that allow for sensing and communication between the binding pockets of adjacent subunits. This work reveals how the sequential order of DNA translocation events among subunits is preserved through trans-subunit interactions and pathways.
Simulation of film transmission path based on ant colony optimization algorithm
Disentangling temperature and Reynolds number effects in quantum turbulence
The interplay between viscous and frictional dissipation is key to understanding quantum turbulence dynamics in superfluid 4 He. Based on a coarse-grained two-fluid description, an original scale-by-scale energy budget that identifies each scale’s contribution to energy dissipation is derived. Using the Hall-Vinen-Bekharevich-Khalatnikov (HVBK) model to further characterize mutual friction, direct numerical simulations at temperatures 1.44 K ≲ T ≲ 2.16 K indicate that mutual friction promotes intense momentum exchanges between the two fluids to maintain a joint energy cascade despite their viscosity mismatch. However, the resulting overall frictional dissipation remains small (compared to the viscous dissipation) and confined to far-dissipative scales. This remarkable feature allows us to define an effective Reynolds number for the turbulence intensity in a two-fluid system, helping to disentangle the effects of Reynolds number and temperature in quantum turbulence. Thereby, simple physical arguments predict that the distance ℓ between quantized vortices (normalized by the turbulence integral scale L 0 ) should behave as ℓ / L 0 ≈ 0.5 Re κ − 3 / 4 with the Reynolds number based on the quantum of circulation κ . This law is well supported by a large set of experimental and numerical data within the temperature range of the HVBK model. Finally, this approach offers the possibility of revisiting the ongoing controversy on intermittency in quantum turbulence. It is shown that observed changes in intermittency arise from Reynolds number effects rather than from temperature variations, as proposed in recent studies.
Thioredoxin regulates T cell proliferation and aggravates the severity of influenza a virus infection
PI(4)P recruits CIDE proteins to promote the formation of unilocular lipid droplets during adipogenesis and hepatic steatosis
Lipid droplets (LDs) are evolutionarily conserved organelles that play important roles in metabolism. Each LD is enclosed by a monolayer of phospholipids, distinct from bilayer membranes. The composition of LD surface phospholipids and their impact on LD growth and function remain to be defined. Phosphoinositides mark cellular organelles and regulate organellar function. Here, we demonstrate that PI(4)P decorates a subset of LDs to recruit and activate CIDE proteins. Enhanced expression of ORP2 and ORP5, LD-associated lipid transfer proteins that remove PI(4)P from LDs, abolished the localization and function of CIDE proteins. Blocking the synthesis of PI(4)P on the LD surface via knocking down PI4K2A also impaired the localization and function of CIDE proteins. In adipocytes, depleting PI(4)P dramatically reduced the size of LDs, as well as adipose tissue mass. In severe steatotic liver, depleting PI(4)P impeded LD enlargement. Our results thus identify a key function of LD surface PI(4)P under physiological conditions and unveil how CIDE proteins are recruited to LDs.
Pre-sleep arousal as a possible mechanism driving sleep problems in relation to ADHD traits
Abstract Attention Deficit Hyperactivity Disorder (ADHD) is inextricably linked with sleep problems. Clinically diagnosed poor sleep is common in ADHD, and subclinical sleep difficulties are frequently reported. However, the mechanisms which underly poor sleep in ADHD are poorly understood. Since one of the most consistently reported sleep difficulties is sleep initiation, it is plausible that pre-sleep arousal plays an important role, but this has not been confirmed. We investigated this by assessing neurotypical adult participants’ self-reported perceptions of their sleep difficulties and pre-sleep arousal in relation to their ADHD-like traits. We acquired two independent datasets: an online dataset (n = 104) and an in-person replication dataset (n = 96). We first assessed the association between ADHD-like traits and sleep quality generally, as well as sleep-onset problems specifically. We then tested the extent to which pre-sleep arousal mediated the association between ADHD traits and sleep initiation problems. There was a clear association in both datasets between ADHD-like traits and their sleep quality – high expression of ADHD-like behaviours coincided with reduced sleep quality. This relationship was largely mediated by the levels of pre-sleep arousal: the link between ADHD-like traits and sleep quality was explained by the relationship between ADHD and (primarily cognitive) pre-sleep arousal. Our findings highlight the role of pre-sleep arousal in the relationship between ADHD-like traits and sleep quality, which could direct future interventions.
In-vitro antimicrobial activity of Jatropha variegata Vahl. (Euphorbiaceae) against some pathogenic microbes isolated from clinical samples in Ibb City, Yemen
Obstacle inversion based on the self-healing property of structured light
Fundamental toughening landscape in soft–hard composites: Insights from a minimal framework
Soft–hard composite strategy is a highly general yet powerful approach to overcome the inherent trade-off between strength and toughness in material design. However, the underlying toughening mechanisms, veiled by nonlinearities and complex network interactions, remains unclear. Here, we employ a three-dimensional soft–hard composite (SH- com ) framework by arranging randomly distributed linear-elastic soft and hard elements to explore the toughening mechanisms of soft–hard composites, while shielding the influence of complex nonlinearities and network architectures. Key features observed in soft–hard composites, including mechanical hysteresis, sacrificial bond-driven toughening, and brittle-to-ductile (BTD) transitions, are successfully reproduced, suggesting that the simplest model captures the essence of toughening in soft–hard composites. Visualization of internal fracture reveals distinct fracture patterns associated with the BTD transition, while numerical and theoretical analyses elucidate its mechanical origins. Furthermore, we identify an optimal toughening composition governed by a unified scaling relation linked to the fracture toughness ratio between soft and hard components. A fundamental toughening phase diagram is also established in terms of strength and toughness. This work sheds light on the underlying toughening landscape of soft–hard composite systems.
Acoustic metasurface constructed by periodic parallel Helmholtz resonators for gas sensing applications
Operando Raman characterization of unique electroinduced molecular tautomerization in zero-gap electrolyzers promotes CO <sub>2</sub> reduction
Membrane electrode assembly (MEA) represents an advanced type of electrochemical device currently widely used in various electrocatalysis applications [e.g., electrochemical CO 2 reduction reaction (CO 2 RR)], featuring no explicit catholyte flow and a unique “solid–liquid–gas” triple-phase interface. Herein, we identify a peculiar electroinduced thiol to thione tautomerization of 4-mercaptopyridine (4MPy) molecule on Cu catalyst surfaces at this triple-phase interface driven by cathodic polarization. This leads to a significant performance improvement of CO 2 RR on Cu with a C 2+ Faradaic efficiency of over 80% with more than 60% C 2 H 4 , as well as a 300 mV reduction of cell voltage compared to bare Cu. A home-designed MEA-type operando Raman cell enables mechanistic studies directly under a current density of over 100 mA cm −2 , elucidating the intricate impacts of the 4MPy tautomerization on the local catalytic environments under real reaction conditions. Surprisingly, this tautomerization does not occur in other commonly utilized electrolyzers, e.g., flow cell and H-cell, even with the same catalyst and electrolyte conditions. The direct contact with the electrolyte in the latter cells was found to cause rapid desorption of 4MPy from the catalyst surface before its possible chemical transformation. These results highlight the opportunities of utilizing surface molecular tautomerization to promote CO 2 RR performance and using the triple phase of MEA to drive reactions that would otherwise be hard to happen in classical electrochemical devices of similar conditions.