Hfq-binding small RNA PqsS regulates Pseudomonas aeruginosa pqs quorum sensing system and virulence.

Pseudomonas aeruginosa is a widespread nosocomial pathogen with a significant to cause both severe planktonic acute and biofilm-related chronic infections. Small RNAs (sRNAs) are noncoding regulatory molecules that are stabilized by the RNA chaperone Hfq to trigger various virulence-related signaling pathways. Here, we identified an Hfq-binding sRNA in P. aeruginosa PAO1, PqsS, which promotes bacterial pathogenicity and pseudomonas quinolone signal quorum sensing (pqs QS) system. Specifically, PqsS enhanced acute bacterial infections by inducing host cell death and promoting rhamnolipid-regulated swarming motility. Meanwhile, PqsS reduced chronic infection traits including biofilm formation and antibiotic resistance. Moreover, PqsS repressed pqsL transcript, increasing PQS levels for pqs QS. A PQS-rich environment promoted PqsS expression, thus forming a positive feedback loop. Furthermore, we demonstrated that the PqsS interacts and destabilizes the pqsL mRNA by recruiting RNase E to drive degradation. These findings provide insights for future research on P. aeruginosa pathogenesis and targeted treatment.

Enhancing Perovskite Solar Cell Performance through Propylamine Hydroiodide Passivation.

In recent years, the power conversion efficiency of perovskite solar cells has increased rapidly. Perovskites can be prepared using simple and cost-effective solution methods. However, the perovskite films obtained are usually polycrystalline and contain numerous defects. Passivation of these defects is crucial for enhancing the performance of solar cells. Here, we report the use of propylamine hydroiodide (PAI) for defect passivation. We found that PAI can result in higher-efficiency cells by reducing the defects and suppressing non-radiative recombination. Consequently, n-i-p perovskite solar cells with a certificated efficiency of 21% were obtained. In addition, PAI exhibited excellent performance in p-i-n devices by serving as a buried interface layer, leading to an improved efficiency of 23%.

Prolonged, staged, and self-regulated methotrexate release coupled with ROS scavenging in an injectable hydrogel for rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) remains a formidable healthcare challenge due to its chronic nature and potential for irreversible joint damage. Methotrexate (MTX) is a cornerstone treatment for RA but carries significant risks of adverse effects with repeated administration, necessitating the exploration of alternative delivery methods. Injectable hydrogels loaded with MTX for intra-articular injection present a promising solution, allowing sustained drug release directly into affected joints. However, current hydrogel systems often lack extended therapeutic periods and the ability to self-regulate drug release according to disease state. Furthermore, RA is associated with excessive production of reactive oxygen species (ROS), which exacerbates inflammation and joint damage. Herein, we developed an advanced injectable hydrogel (MPDANPs/MTX HA-PEG gel) based on "bio-orthogonal chemistry", combining hyaluronic acid and polyethylene glycol (PEG) matrices co-loaded with mesoporous polydopamine nanoparticles (MPDANPs) and MTX. MPDANPs/MTX HA-PEG gel achieved prolonged, staged, and self-regulated MTX release, coupled with ROS scavenging capabilities for enhanced therapeutic efficacy. Due to its optimized MTX release behavior and significant ROS scavenging function, MPDANPs/MTX HA-PEG gel exhibited potent anti-inflammatory effects in collagen-induced arthritis (CIA) rats following a single intra-articular injection. Our findings highlight the potential of MPDANPs/MTX HA-PEG gel as a highly effective treatment strategy for RA, offering a promising avenue for improving patient outcomes.

Counterion Distribution in the Stern Layer on Charged Surfaces.

Counterion adsorption at the solid-liquid interface affects numerous applications. However, the counterion adsorption density in the Stern layer has remained poorly evaluated. Here we report the direct determination of surface charge density at the shear plane between the Stern layer and the diffuse layer. By the Grahame equation extension and streaming current measurements for different solid surfaces in different aqueous electrolytes, we are able to obtain the counterion adsorption density in the Stern layer, which is mainly related to the surface charge density but is less affected by the bulk ion concentration. The charge inversion concentration is further found to be sensitive to the ion type and ion valence rather than to the charged surface, which is attributed to the ionic competitive adsorption and ion-ion correlations. Our findings offer a framework for understanding ion distribution in many physical and chemical processes where the Stern layer is ubiquitous.

Deterministic switching of perpendicular magnetization by out-of-plane anti-damping magnon torques.

Spin-wave excitations of magnetic moments (or magnons) can transport spin angular momentum in insulating magnetic materials. This property distinguishes magnonic devices from traditional electronics, where power consumption results from electrons' movement. Recently, magnon torques have been used to switch perpendicular magnetization in the presence of an external magnetic field. Here we present a material system composed of WTe2/antiferromagnetic insulator NiO/ferromagnet CoFeB heterostructures that allows magnetic field-free switching of the perpendicular magnetization. The magnon currents, with a spin polarization canting of -8.5° relative to the sample plane, traverse the 25-nm-thick polycrystalline NiO layer while preserving their original polarization direction, subsequently exerting an out-of-plane anti-damping magnon torque on the ferromagnetic layer. Using this mechanism, we achieve a 190-fold reduction in power consumption in PtTe2/WTe2/NiO/CoFeB heterostructures compared to Bi2Te3/NiO/CoFeB control samples, which only exhibit in-plane magnon torques. Our field-free demonstration contributes to the realization of all-electric, low-power, perpendicular magnetization switching devices.

Screening structure and predicting toxicity of pesticide adjuvants using molecular dynamics simulation and machine learning for minimizing environmental impacts.

Surfactants as synergistic agents are necessary to improve the stability and utilization of pesticides, while their use is often accompanied by unexpected release into the environment. However, there are no efficient strategies available for screening low-toxicity surfactants, and traditional toxicity studies rely on extensive experimentation which are not predictive. Herein, a commonly used agricultural adjuvant Triton X (TX) series was selected to study the function of amphipathic structure to their toxicity in zebrafish. Molecular dynamics (MD) simulations, transcriptomics, metabolomics and machine learning (ML) were used to study the toxic effects and predict the toxicity of various TX. The results showed that TX with a relatively short hydrophilic chain was highly toxic to zebrafish with LC50 of 1.526 mg/L. However, TX with a longer hydrophilic chain was more likely to damage the heart, liver and gonads of zebrafish through the arachidonic acid metabolic network, suggesting that the effect of surfactants on membrane permeability is the key to determine toxic results. Moreover, biomarkers were screened through machine learning, and other hydrophilic chain lengths were predicted to affect zebrafish heart health potentially. Our study provides an advanced adjuvants screening method to improve the bioavailability of pesticides while reducing environmental impacts.

A novel nanobody broadly neutralizes SARS-CoV-2 via induction of spike trimer dimers conformation.

The ongoing mutations of the SARS-CoV-2 pose serious challenges to the efficacy of the available antiviral drugs, and new drugs with fantastic efficacy are always deserved investigation. Here, a nanobody called IBT-CoV144 is reported, which exhibits broad neutralizing activity against SARS-CoV-2 by inducing the conformation of spike trimer dimers. IBT-CoV144 was isolated from an immunized alpaca using the RBD of wild-type SARS-CoV-2, and it showed strong cross-reactive binding and neutralizing potency against diverse SARS-CoV-2 variants, including Omicron subvariants. Moreover, the prophylactically and therapeutically intranasal administration of IBT-CoV144 confers fantastic protective efficacy against the challenge of Omicron BA.1 variant in BALB/c mice model. The structure analysis of the complex between spike (S) protein, conducted using Cryo-EM, revealed a special conformation known as the trimer dimers. This conformation is formed by two trimers, with six RBDs in the "up" state and bound by six VHHs. IBT-CoV144 binds to the lateral region of the RBD on the S protein, facilitating the aggregation of S proteins. This aggregation results in steric hindrance, which disrupts the recognition of the virus by ACE2 on host cells. The discovery of IBT-CoV144 will provide valuable insights for the development of advanced therapeutics and the design of next-generation vaccines.

Disparate External Electric Field Effect on the Adsorption and Shear Behavior of Monovalent and Trivalent Ions in Electrolyte Solution.

Reducing friction is of great interest, and an external potential applied to the friction pair can regulate lubricity. Electrochemical atomic force microscopy (EC-AFM) is used to study the tribological and adsorption behavior of monovalent and trivalent ionic solutions between charged surfaces. An opposite trend of coefficient of friction (COF) and normal force that varies with the applied electric potential is witnessed. Direct force measurements and theoretical models have disclosed that, for the NaCl solution, the negative electric field reduces the COF by increasing cation adsorption. As for LaCl3 solution, the positive electric field promotes the primary adsorption of anions on HOPG, resulting in the disappearance of the attractive ion-ion correlation between the trivalent ions, thereby reducing the COF. The shear behavior of adsorbed ions in electrolyte solution is sensitive to their valence, because of their different surface force contribution. The study further provides a framework to optimize the design of hydration lubrication.

Above-room-temperature chiral skyrmion lattice and Dzyaloshinskii-Moriya interaction in a van der Waals ferromagnet Fe3-xGaTe2.

Skyrmions in existing 2D van der Waals (vdW) materials have primarily been limited to cryogenic temperatures, and the underlying physical mechanism of the Dzyaloshinskii-Moriya interaction (DMI), a crucial ingredient for stabilizing chiral skyrmions, remains inadequately explored. Here, we report the observation of Néel-type skyrmions in a vdW ferromagnet Fe3-xGaTe2 above room temperature. Contrary to previous assumptions of centrosymmetry in Fe3-xGaTe2, the atomic-resolution scanning transmission electron microscopy reveals that the off-centered FeΙΙ atoms break the spatial inversion symmetry, rendering it a polar metal. First-principles calculations further elucidate that the DMI primarily stems from the Te sublayers through the Fert-Lévy mechanism. Remarkably, the chiral skyrmion lattice in Fe3-xGaTe2 can persist up to 330 K at zero magnetic field, demonstrating superior thermal stability compared to other known skyrmion vdW magnets. This work provides valuable insights into skyrmionics and presents promising prospects for 2D material-based skyrmion devices operating beyond room temperature.

A responsive nanoplatform with molecular and structural imaging capacity for assisting accurate diagnosis of early rheumatoid arthritis.

Accurate early diagnosis of rheumatoid arthritis (RA) and prompt implementation of appropriate treatment approaches are crucial. In the clinic, magnetic resonance imaging (MRI) has been recommended for implementation to aid in the precise and early diagnosis of RA. However, they are still limited by issues regarding specificity and their ability to capture comprehensive information about the pathological features. Herein, a responsive multifunctional nanoplatform with targeting capabilities (hMnO2-IR@BSA-PEG-FA) is constructed through integrating a RA microenvironment-responsive MRI contrast agent with activatable near-infrared (NIR) fluorescence imaging, aiming to simultaneously acquire comprehensive pathological features of RA from both structural and molecular imaging perspectives. Moreover, taking advantage of its targeting function to synovial microphages, hMnO2-IR@BSA-PEG-FA demonstrated a remarkable capability to accumulate effectively at the synovial tissue. Additionally, hMnO2 responded to the mild acidity and reactive oxygen species (ROS) in the RA microenvironment, leading to the controlled release of Mn2+ ions and IR780, which separately caused special MRI contrast enhancement of synovial tissues and sensitively demonstrated the presence of ROS and weakly acid microenvironment by NIR imaging. Consequently, hMnO2-IR@BSA-PEG-FA is expected to serve as a promising nanoplatform, offering valuable assistance in the precise diagnosis of early-stage RA by specially providing comprehensive information about the pathological features.

Tribological Behavior of Sulfonated Polyether Ether Ketone with Three Different Chemical Structures under Water Lubrication.

With the development of the shipbuilding industry, it is necessary to improve tribological properties of polyether ether ketone (PEEK) as a water-lubricated bearing material. In this study, the sulfonated PEEK (SPEEK) with three distinct chemical structures was synthesized through direct sulfonated polymerization, and high fault tolerance and a controllable sulfonation degree ensured the batch stability. The tribological and mechanical properties of SPEEK with varying side groups (methyl and tert-butyl) and rigid segments (biphenyl) were compared after sintering in a vacuum furnace. Compared to the as-made PEEK, as the highly electronegative sulfonic acid group enhanced the hydration lubrication, the friction coefficient and wear rate of SPEEK were significantly reduced by 30% and 50% at least without affecting the mechanical properties. And lower steric hindrance and entanglement between molecular chains were proposed to be partially responsible for the lowest friction behavior of SPEEK with methyl side groups, making it a promising and competitive option for water-lubricated bearings.

Reconfigurable spin current transmission and magnon-magnon coupling in hybrid ferrimagnetic insulators.

Coherent spin waves possess immense potential in wave-based information computation, storage, and transmission with high fidelity and ultra-low energy consumption. However, despite their seminal importance for magnonic devices, there is a paucity of both structural prototypes and theoretical frameworks that regulate the spin current transmission and magnon hybridization mediated by coherent spin waves. Here, we demonstrate reconfigurable coherent spin current transmission, as well as magnon-magnon coupling, in a hybrid ferrimagnetic heterostructure comprising epitaxial Gd3Fe5O12 and Y3Fe5O12 insulators. By adjusting the compensated moment in Gd3Fe5O12, magnon-magnon coupling was achieved and engineered with pronounced anticrossings between two Kittel modes, accompanied by divergent dissipative coupling approaching the magnetic compensation temperature of Gd3Fe5O12 (TM,GdIG), which were modeled by coherent spin pumping. Remarkably, we further identified, both experimentally and theoretically, a drastic variation in the coherent spin wave-mediated spin current across TM,GdIG, which manifested as a strong dependence on the relative alignment of magnetic moments. Our findings provide significant fundamental insight into the reconfiguration of coherent spin waves and offer a new route towards constructing artificial magnonic architectures.

Salinity-Driven Interface Self-Assembly of a Biological Amphiphilic Emulsifier to Form Stable Janus Core-Shell Emulsion for Enhancing Agrichemical Delivery.

Agrichemical losses are a severe threat to the ecological environment. Additionally, some agrichemical compounds contain abundant salt, which increases the instability of formulations, leading to a lower agrichemical utilization and soil hardening. Fortunately, the biological amphiphilic emulsifier sodium deoxycholate alleviates these problems by forming stable Janus core-shell emulsions through salinity-driven interfacial self-assembly. According to the interfacial behavior, dilational rheology, and molecular dynamics simulations, Janus-emulsion molecules are more closely arranged than traditional-emulsion molecules and generate an oil-water interfacial film that transforms into a gel film. In addition, at the same spray volume, the deposition area of the Janus emulsion increased by 37.70% compared with that of the traditional emulsion. Owing to the topology effect and deformation, the Janus emulsion adheres to rice micropapillae, achieving better flush resistance. Meanwhile, based on response of the Janus emulsion to stimulation by carbon dioxide (CO2), the emulsion lost to the soil can form a rigid shell for inhibiting the release of pesticides and metal ions from harming the soil. The pyraclostrobin release rate decreased by 50.89% at 4 h after the Janus emulsion was exposed to CO2. The Chao1 index of the Janus emulsion was increased by 12.49% as compared to coconut oil delivery in soil microbial community. The Janus emulsion ingested by harmful organisms can be effectively absorbed in the intestine to achieve better control effects. This study provides a simple and effective strategy, which turns waste into treasure, by combining metal ions in agrichemicals with natural amphiphilic molecules to prepare stable emulsions for enhancing agrichemical rainfastness and weakening environmental risk.

Association of Antidiabetic Drug Target Genes with Inflammatory Bowel Disease: A Mendelian Randomization Study.

Background: An unmet medical need for the treatment of inflammatory bowel disease (IBD) exists. A part of antidiabetic drugs had potential effects on IBD in various observational research. Objective: To investigate the potential of antidiabetic drugs on IBD. Methods: We undertook a summary-data-based Mendelian randomization (SMR) using the expression quantitative trait loci (eQTL) expressed in the blood or colon and a two sample Mendelian randomization (TSMR) utilizing single nucleotide polymorphism (SNP) of antidiabetic drug target genes mediated by blood glucose traits. Participants encompassed patients with IBD (25,042 cases/34,915 controls), UC (12,366 cases/33,609 controls), and CD (12,194 cases/28,072 controls). Data on eQTL in the blood or the colon were from the eQTLGen consortium (31,684 individuals) or GTEx Consortium V8, respectively. SMR was performed by SMR software (20,220,322); the primary method for TSMR was inverse-variance weighted (IVW) or Wald ratio through R studio (2023.06.0+421). Sensitivity analyses were carried out. Results: A 1-SD upper expression of the KCNJ11 gene (target gene of sulfonylureas) in the blood reduced the risk of CD (OR per 1-SD = 0.728, 95% CI = 0.586-0.903, P = 0.004) according to the result of SMR. ABCC8 (target gene of sulfonylureas) expressed in the colon did not affect CD, UC, or IBD. T2D-mediated KCNJ11 has a protective effect on CD (OR = 0.475, 95% CI = 0.297-0.761, P = 0.002). Gene predicted no relationship between T2D and CD. Conclusion: Sulfonylureas (SUs) may have side effects on CD. This work provides some suggestions for the selection of antidiabetic drugs in patients with CD.

Causal Association Analysis of Periodontitis and Inflammatory Bowel Disease: A Bidirectional Mendelian Randomization Study.

BACKGROUND: Periodontitis has been reported to be associated with inflammatory bowel disease (IBD), including ulcerative colitis (UC), and Crohn's disease (CD). However, the causality of these 2 diseases remains unclear. We conducted bidirectional Mendelian randomization (MR) to investigate the causal relationship between periodontitis and IBD. METHODS: We obtained the genome-wide association study (GWAS) summary data of European populations from FinnGen database (for IBD) and a published article (for periodontitis), from which independent single nucleotide polymorphisms were selected as instrumental variables. Inverse variance-weighted (IVW), MR-Egger, and weighted median (WM) methods were utilized for MR analysis. Heterogeneity or pleiotropy was detected through Cochran's Q test and MR-Egger intercept, respectively. Outlier was identified with MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier) and leave-one-out analysis. All statistical analyses were performed with R 4.2.1 and the packages of TwoSampleMR version 0.5.6. RESULTS: Genetic prediction showed that periodontitis was the risk factor of UC (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.01-1.26; P = .027), rather than of CD (OR, 0.92; 95% CI, 0.74-1.15; P = .456) and IBD (OR, 0.96; 95% CI, 0.81-1.13; P = .619). To the contrary, CD, not UC or IBD, resulted in exacerbating periodontitis in terms of the results of the IVW (OR, 1.09; 95% CI, 1.01-1.17; P = .021) and WM (OR, 1.10; 95% CI, 1.01-1.20; P = .030) methods. Heterogeneity or pleiotropy was acceptable. CONCLUSIONS: Our results indicated that CD was the risk factor for periodontitis; conversely, periodontitis was responsible for the exacerbation of UC, enhancing the existence of mouth-gut axis. Patients with UC should pay more attention to periodontal health, while patients with periodontitis should actively pay close heed to intestinal health.

A bidirectional Mendelian randomization study indicated that Crohn's disease was the risk factor for periodontitis; conversely, periodontitis was responsible for the exacerbation of ulcerative colitis, enhancing the existence of the mouth-gut axis and suggesting paying attention to oral health for patients of inflammatory bowel disease.

Quantitative anatomical analysis of lumbar interspaces based on 3D CT imaging: optimized segment selection for lumbar puncture in different age groups.

BACKGROUND: Optimal lumbar puncture segment selection remains controversial. This study aims to analyze anatomical differences among L3-4, L4-5, and L5-S1 segments across age groups and provide quantitative evidence for optimized selection. METHODS: 80 cases of CT images were collected with patients aged 10-80 years old. Threedimensional models containing L3-S1 vertebrae, dural sac, and nerve roots were reconstructed. Computer simulation determined the optimal puncture angles for the L3-4, L4-5, and L5-S1 segments. The effective dural sac area (ALDS), traversing nerve root area (ATNR), and area of the lumbar inter-laminar space (ALILS) were measured. Puncture efficacy ratio (ALDS/ALILS) and nerve injury risk ratio (ATNR/ALILS) were calculated. Cases were divided into four groups: A (10-20 years), B (21-40 years), C (41-60 years), and D (61-80 years). Statistical analysis was performed using SPSS. RESULTS: 1) ALDS was similar among segments; 2) ATNR was greatest at L5-S1; 3) ALILS was greatest at L5-S1; 4) Puncture efficacy ratio was highest at L3-4 and lowest at L5-S1; 5) Nerve injury risk was highest at L5-S1. In group D, L5-S1 ALDS was larger than L3-4 and L4-5. ALDS decreased after age 40. Age variations were minimal across parameters. CONCLUSION: The comprehensive analysis demonstrated L3-4 as the optimal first-choice segment for ages 10-60 years, conferring maximal efficacy and safety. L5-S1 can serve as an alternative option for ages 61-80 years when upper interspaces narrow. This study provides quantitative imaging evidence supporting age-specific, optimized lumbar puncture segment selection.

Strain-Induced Reversible Motion of Skyrmions at Room Temperature.

Magnetic skyrmions are topologically protected swirling spin textures with great potential for future spintronic applications. The ability to induce skyrmion motion using mechanical strain not only stimulates the exploration of exotic physics but also affords the opportunity to develop energy-efficient spintronic devices. However, the experimental realization of strain-driven skyrmion motion remains a formidable challenge. Herein, we demonstrate that the inhomogeneous uniaxial compressive strain can induce the movement of isolated skyrmions from regions of high strain to regions of low strain at room temperature, which was directly observed using an in situ Lorentz transmission electron microscope with a specially designed nanoindentation holder. We discover that the uniaxial compressive strain can transform skyrmions into a single domain with in-plane magnetization, resulting in the coexistence of skyrmions with a single domain along the direction of the strain gradient. Through comprehensive micromagnetic simulations, we reveal that the repulsive interactions between skyrmions and the single domain serve as the driving force behind the skyrmion motion. The precise control of skyrmion motion through strain provides exciting opportunities for designing advanced spintronic devices that leverage the intricate interplay between strain and magnetism.

Effect of the Molecular Structure of 1,3-Diketones on the Realization of Oil-Based Superlubricity on Steel/Steel Friction Pairs.

In this article, five kinds of 1,3-diketones and their chelates with different molecular structures were prepared, and their tribological properties were tested. The experimental results show that the running-in time and friction coefficient of the friction pairs lubricated by 1,3-diketones containing a benzene ring increased with the increase of the carbon chain length. In addition, only the friction pair lubricated by 1-(4-ethylphenyl)-butane-1,3-dione (0201) and 1-(4-ethylphenyl)-nonane-1,3-dione (0206) could achieve stable superlubricity. When the benzene ring was replaced with a carbon six-membered ring, it was found that although the friction pair lubricated by this lubricant could achieve superlubricity, the wear of the friction pair was severe, and obvious abrasive wear occurred. In addition, the lubricants prepared by mixing 1,3-diketones and the corresponding chelates in a ratio of 4:6 had greatly improved lubricating properties compared to 1,3-diketones. Through X-ray photoelectron spectroscopy (XPS) analysis of the surface of the friction pair after the test and Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) analyses of 1,3-diketones before and after the experiment, we found that the necessary conditions for the friction pair lubricated by 1,3-diketone to achieve superlubricity were formation of tribochemical adsorption films and the presence of chelates in solution.

High-performance van der Waals antiferroelectric CuCrP2S6-based memristors.

Layered thio- and seleno-phosphate ferroelectrics, such as CuInP2S6, are promising building blocks for next-generation nonvolatile memory devices. However, because of the low Curie point, the CuInP2S6-based memory devices suffer from poor thermal stability (<42 °C). Here, exploiting the electric field-driven phase transition in the rarely studied antiferroelectric CuCrP2S6 crystals, we develop a nonvolatile memristor showing a sizable resistive-switching ratio of ~ 1000, high switching endurance up to 20,000 cycles, low cycle-to-cycle variation, and robust thermal stability up to 120 °C. The resistive switching is attributed to the ferroelectric polarization-modulated thermal emission accompanied by the Fowler-Nordheim tunneling across the interfaces. First-principles calculations reveal that the good device performances are associated with the exceptionally strong ferroelectric polarization in CuCrP2S6 crystal. Furthermore, the typical biological synaptic learning rules, such as long-term potentiation/depression and spike amplitude/spike time-dependent plasticity, are also demonstrated. The results highlight the great application potential of van der Waals antiferroelectrics in high-performance synaptic devices for neuromorphic computing.