High-Entropy Engineering Reinforced Surface Electronic States and Structural Defects of Hierarchical Metal Oxides@Graphene Fibers toward High-Performance Wearable Supercapacitors.

Construction advanced fibers with high Faradic activity and conductivity are effective to realize high energy density with sufficient redox reactions for fiber-based electrochemical supercapacitors (FESCs), yet it is generally at the sacrifice of kinetics and structural stability. Here, a high-entropy doping strategy is proposed to develop high-energy-density FESCs based on high-entropy doped metal oxide@graphene fiber composite (HE-MO@GF). Due to the synergistic participation of multi-metal elements via high-entropy doping, the HE-MO@GF features abundant oxygen vacancies from introducing various low-valence metal ions, lattice distortions, and optimized electronic structure. Consequently, the HE-MO@GF maintains sufficient active sites, a low diffusion barrier, fast adsorption kinetics, improved electronic conductivity, enhanced structural stability, and Faradaic reversibility. Thereinto, HE-MO@GF presents ultra-large areal capacitance (3673.74 mF cm-2) and excellent rate performance (1446.78 mF cm-2 at 30 mA cm-2) in 6 M KOH electrolyte. The HE-MO@GF-based solid-state FESCs also deliver high energy density (132.85 µWh cm-2), good cycle performance (81.05% of capacity retention after 10,000 cycles), and robust tolerance to sweat erosion and multiple washing, which is woven into the textile to power various wearable devices (e.g., watch, badge and luminous glasses). This high-entropy strategy provides significant guidance for designing innovative fiber materials and highlights the development of next-generation wearable energy devices.

Nanoengineering-Enhanced Capillary Cooling Achieves Sustained Thermal Protection for Ultra-High Heat Flux and Temperature.

Extreme thermal conditions with heat flux densities exceeding 1 MW·m-2 or temperatures reaching up to 1000 °C are prevalent in various situations. However, the ability of thermal protection either depends on specialized materials or is currently limited with existing cooling schemes. Herein, we propose an innovative cooling scheme that relies on evaporation-driven capillary flow enhanced by nanoengineering-designed porous structures with common materials. Experimentally-obtained capillary flow cooling curve identifies critical heat flux corresponding to evaporation-driven flow stage, where coolants cool the surface and subsequent vapor impedes heat transfer from thermal boundaries. Nanoengineering provides opportunities for enhanced capillary flow, which proves to endow bronze, TC4, and Al2O3 with thermal protection ability 50%-180% higher than that without nanoengineering-designed. Our scheme achieves critical heat flux up to 2.0-3.1 MW·m-2, and performs thermal dissipation capacity almost twice higher than inherent latent heat of coolant. Furthermore, in a supersonic wind tunnel with total temperature reaching up to 1792 K, our scheme effectively protects surfaces by cooling them to surface temperatures below 500 K. Nanoengineering-enhanced capillary cooling gives access to the application of common materials for high-temperature and high-heat-flux environments and paves the way for the development of lightweight, long-lasting, and large-scale solutions for thermal protection. This article is protected by copyright. All rights reserved.

Percolation transitions of confinement-induced layering and intralayer structural orders in three-dimensional Yukawa liquids.

The disorder-order transitions of layering and intralayer structural orders of three-dimensional Yukawa liquids, under the enhanced confinement effect with decreasing normal distance z to the confinement boundary, is investigated numerically. The liquid between the two flat boundaries is segmented into many slabs parallel to the boundary, with the same slab width as the layer width. In each slab, particle sites are binarized into sites with layering order (LOSs)/ layering disorder (LDSs) and with intralayer structural order (SOSs)/disorder (SDSs). It is found that with decreasing z, a small fraction of LOSs starts to heterogeneously emerge in the form of small clusters in the slab, followed by the emergence of the large percolating LOS clusters spanning over the system. The smooth rapid rise of the fraction of LOSs from small values followed by their gradual saturations, and the scaling behavior of multiscale LOS clustering, are similar to those of the nonequilibrium systems governed by the percolation theory. The disorder-order transition of intraslab structural ordering also exhibits a similar generic behavior as that of layering with the same transition slab number. The spatial fluctuations of local layering order and local intralayer structural order are uncorrelated in the bulk liquid and the outmost layer next to the boundary. Approaching the percolating transition slab, their correlation gradually increases to the maximum.

RdmA Is a Key Regulator in Autoinduction of DSF Quorum Quenching in Pseudomonas nitroreducens HS-18.

Diffusible signal factor (DSF) represents a family of widely conserved quorum-sensing (QS) signals which regulate virulence factor production and pathogenicity in numerous Gram-negative bacterial pathogens. We recently reported the identification of a highly potent DSF-quenching bacterial isolate, Pseudomonas nitroreducens HS-18, which contains an operon with four DSF-inducible genes, digABCD, or digA-D, that are responsible for degradation of DSF signals. However, the regulatory mechanisms that govern the digA-D response to DSF induction have not yet been characterized. In this study, we identified a novel transcriptional regulator we designated RdmA (regulator of DSF metabolism) which negatively regulates the expression of digA-D and represses DSF degradation. In addition, we found that a gene cluster located adjacent to rdmA was also negatively regulated by RdmA and played a key role in DSF degradation; this cluster was hence named dmg (DSF metabolism genes). An electrophoretic mobility shift assay and genetic analysis showed that RdmA represses the transcriptional expression of the dmg genes in a direct manner. Further studies demonstrated that DSF acts as an antagonist and binds to RdmA, which abrogates RdmA binding to the target promoter and its suppression on transcriptional expression of the dmg genes. Taken together, the results from this study have unveiled a central regulator and a gene cluster associated with the autoinduction of DSF degradation in P. nitroreducens HS-18, and this will aid in the understanding of the genetic basis and regulatory mechanisms that govern the quorum-quenching activity of this potent biocontrol agent. IMPORTANCE DSF family quorum-sensing (QS) signals play important roles in regulation of bacterial physiology and virulence in a wide range of plant and human bacterial pathogens. Quorum quenching (QQ), which acts by either degrading QS signals or blocking QS communication, has proven to be a potent disease control strategy, but QQ mechanisms that target DSF family signals and associated regulatory mechanisms remain largely unknown. Recently, we identified four autoinduced DSF degradation genes (digABCD) in P. nitroreducens HS-18. By using a combination of transcriptome and genetic analysis, we identified a central regulator that plays a key role in autoinduction of dig expression, as well as a new gene cluster (dmgABCDEFGH) involved in DSF degradation. The significance of our study is in unveiling the autoinduction mechanism that governs DSF signal quorum quenching for the first time, to our knowledge, and in identification of new genes and enzymes responsible for DSF degradation. The findings from this study shed new light on our understanding of the DSF metabolism pathway and the regulatory mechanisms that modulate DSF quorum quenching and will provide useful clues for design and development of a new generation of highly potent QQ biocontrol agents against DSF-mediated bacterial infections.

Role of trapped liquid in flow boiling inside micro-porous structures: pore-scale visualization and heat transfer enhancement.

Flow boiling is an important heat dissipation method for cooling high heat flux surfaces in many industrial applications. The heat transfer can be further enhanced by using porous media surfaces due to their high specific surface areas. However, although flow boiling in channels is well understood, the phase-change behavior with the additional capillary effect induced by the porous structures is not well understood, and the design of the porous structures is difficult to avoid dryout and over-temperature accidents. A pore-scale lab-on-a-chip method was used here to investigate the flow boiling heat transfer characteristics inside micro-porous structures. The flow patterns, captured in the two-phase region with a uniform pore-throat size of 30 µm, showed that liquid was trapped in the pore-throat structures as both dispersed liquid bridges and liquid films. Moreover, the liquid film was shown to be moving on the wet solid surface by laser-induced fluorescence and particle tracking. A theoretical analysis showed that the capillary pressure difference between adjacent liquid bridges could drive the liquid film flows, which helped maintain the coolant supply in the two-phase region. The pore-throat parameters could be designed to enhance the capillary pressure difference with multiple throat sizes of 10 - 90 µm which would enhance the heat transfer 5% - 10% with a 5% - 23% pressure drop reduction. This research provides another method for improving the flow boiling heat transfer through the porous structure design besides changing the surface wettability.

Surface-Induced Layering of Quenched 3D Dusty Plasma Liquids: Micromotion and Structural Rearrangement.

We experimentally demonstrate confinement surface induced layering with a fluctuating layering front, and investigate the heterogeneous 3D crystalline ordered structure, cooperative micromotion, and structural rearrangement in the layered region of a quenched dusty plasma liquid. It is found that, after quenching the liquid with 2 to 3 layers adjacent to its flat bottom boundary, the layering front invades upward and exhibits turbulentlike fluctuations with power law decays in spatial and temporal power spectra. The layered region can be viewed as a 2+1D system with vertically coupled horizontal 2D layers, in which particle translayer motions are nearly fully suppressed. Each layer exhibits hexatic structure with a slow decay of long-range triangular lattice order. The nearly parallel but with different horizontal shifts of intralayer lattice lines of adjacent layers allows the heterogeneous fcc, bcc, and hcp structures with specific lattice orientations. In each layer, particles exhibit thermally excited horizontal motions of alternative cage rattling and cooperative hopping, which cause intralayer lattice line wiggling and triangular crystalline domain rupture or healing, respectively. The different intralayer cooperative motion of adjacent layers is the key for interlayer slip causing the structural rearrangement of 3D crystalline ordered domains.

Multiscale Coherent Excitations in Microscopic Acoustic Wave Turbulence of Cold Dusty Plasma Liquids.

We experimentally demonstrate the observation of thermally excited microscopic acoustic wave turbulence at the discrete level in quasi-two-dimensional cold dusty plasma liquids. Through multidimensional empirical mode decomposition of individual dust particle motions over a large area, the turbulence is decomposed into multiscale traveling wave modes, sharing self-similar dynamics. All modes exhibit intermittent excitation, propagation, scattering, and annihilation of coherent waves, in the form of clusters in the xyt space, with cluster sizes exhibiting self-similar power law distribution. The poor particle interlocking in the region with poor structural order is the key origin of the easier excitations of the large amplitude slow modes. The sudden phase synchronization of slow wave modes switches particle motion from cage rattling to cooperative hopping.

Decreased miR-503 expression in gastric cancer is inversely correlated with serum carcinoembryonic antigen and acts as a potential prognostic and diagnostic biomarker.

BACKGROUND: Altered expression of miR-503 has been linked to human carcinogenesis. In this present study, we aimed to detect the potential for miR-503 as a novel biomarker for gastric cancer (GC) patients. MATERIALS AND METHODS: The relative mRNA level of miR-503 in serum and tissue of 68 GC patients and serum of 32 healthy volunteers was determined by real-time reverse transcription quantitative polymerase chain reaction. RESULTS: The miR-503 level was significantly lower in the tissue and serum of GC than their counterparts (all P<0.01). Downregulation of miR-503 was found to be corrected with more aggressive tumor. Patients in the high-miR-503 group showed significantly better overall survival compared to the low-miR-503 group (P=0.021). The serum miR-503 level in GC was inversely correlated with carcinoembryonic antigen (CEA) (r=-0.624, P<0.001). Furthermore, the area under the receiver operating characteristic curve for miR-503 discriminating GC patients from healthy individuals was 0.889 (P=0.006), with a sensitivity of 96.8% and a specificity of 79.4%, higher than that of CEA (area under the receiver operating characteristic curve =0.681, P=0.048). CONCLUSION: The present study suggests that the expression level of miR-503 may serve as prognostic and diagnostic biomarker for GC.