TiO2/SiO2 spiral crimped Janus fibers engineered for stretchable ceramic membranes with high-temperature resistance.

The tensile brittleness of ceramic nanofibrous materials makes them unable to withstand the relatively large fracture strain, greatly limiting their applications in extreme environments such as high or ultra-low temperatures. Herein, highly stretchable and elastic ceramic nanofibrous membranes composed of titanium dioxide/silicon dioxide (TiO2/SiO2) bicomponent spiral crimped Janus fibers were designed and synthesized via conjugate electrospinning combined with calcination treatment. Owing to the opposite charges attached, the two fibers assembled side by side to form a Janus structure. Interestingly, radial shrinkage differences existed on the two sides of the TiO2/SiO2 composite nanofibers, constructing a helical crimp structure along the fiber axis. The special configuration effectively improves the stretchability of TiO2/SiO2 ceramic nanofibrous membranes, with up to 70.59% elongation at break, excellent resilience at 20% tensile strain and plastic deformation of only 3.48% after 100 cycles. Additionally, the relatively fluffy ceramic membranes constructed from spiral crimped Janus fibers delivered a lower thermal conductivity of 0.0317 W m-1 K-1, attributed to the increased internal still air content. This work not only reveals the attractive tensile mechanism of ceramic membranes arising from the highly curly nanofibers, but also proposes an effective strategy to make the ceramic materials withstand the complex dynamic strain in extreme temperature environments (from -196 °C to 1300 °C).

Multiphase Symbiotic Engineered Elastic Ceramic-Carbon Aerogels with Advanced Thermal Protection in Extreme Oxidative Environments.

Elastic aerogels can dissipate aerodynamic forces and thermal stresses by reversible slipping or deforming to avoid sudden failure caused by stress concentration, making them the most promising candidates for thermal protection in aerospace applications. However, existing elastic aerogels face difficulties achieving reliable protection above 1500 °C in aerobic environments due to their poor thermomechanical stability and significantly increased thermal conductivity at elevated temperatures. Here, a multiphase sequence and multiscale structural engineering strategy is proposed to synthesize mullite-carbon hybrid nanofibrous aerogels. The heterogeneous symbiotic effect between components simultaneously inhibits ceramic crystalline coarsening and carbon thermal etching, thus ensuring the thermal stability of the nanofiber building blocks. Efficient load transfer and high interfacial thermal resistance at crystalline-amorphous phase boundaries on the microscopic scale, coupled with mesoscale lamellar cellular and locally closed-pore structures, achieve rapid stress dissipation and thermal energy attenuation in aerogels. This robust thermal protection material system is compatible with ultralight density (30 mg cm-3), reversible compression strain of 60%, extraordinary thermomechanical stability (up to 1600 °C in oxidative environments), and ultralow thermal conductivity (50.58 mW m-1 K-1 at 300 °C), offering new options and possibilities to cope with the harsh operating environments faced by space exploration.

Ceramic Meta-Aerogel with Thermal Superinsulation up to 1700 °C Constructed by Self-Crosslinked Nanofibrous Network via Reaction Electrospinning.

Thermal insulation under extreme conditions requires the materials to be capable of withstanding complex thermo-mechanical stress, significant gradient temperature transition, and high-frequency thermal shock. The excellent structural and functional properties of ceramic aerogels make them attractive for thermal insulation. However, in extremely high-temperature environments (above 1500 °C), they typically exhibit limited insulation capacity and thermo-mechanical stability, which may lead to catastrophic accidents, and this problem is never effectively addressed. Here, a novel ceramic meta-aerogel constructed from a crosslinked nanofiber network using a reaction electrospinning strategy, which ensures excellent thermo-mechanical stability and superinsulation under extreme conditions, is designed. The ceramic meta-aerogel has an ultralow thermal conductivity of 0.027 W m-1 k-1, and the cold surface temperature is only 303 °C in a 1700 °C high-temperature environment. After undergoing a significant gradient temperature transition from liquid nitrogen to 1700 °C flame burning, the ceramic meta-aerogel can still withstand thousands of shears, flexures, compressions, and other complex forms of mechanical action without structural collapse. This work provides a new insight for developing ceramic aerogels that can be used for a long period in extremely high-temperature environments.

Quantitative differentiation of non-invasive bladder urothelial carcinoma and inverted papilloma based on CT urography.

PURPOSE: To investigate the value of CT urography (CTU) indicators in the quantitative differential diagnosis of bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB). MATERIAL AND METHODS: The clinical and preoperative CTU imaging data of continuous 103 patients with histologically confirmed BUC or IPB were retrospectively analyzed. The imaging data included 6 qualitative indicators and 7 quantitative measures. The recorded clinical information and imaging features were subjected to univariate and multivariate logistic regression analysis to find independent risk factors for BUC, and a combined multi-indicator prediction model was constructed, and the prediction model was visualized using nomogram. ROC curve analysis was used to calculate and compare the predictive efficacy of independent risk factors and nomogram. RESULTS: Junction smoothness, maximum longitudinal diameter, tumor-wall interface and arterial reinforcement rate were independent risk factors for distinguishing BUC from IPB. The AUC of the combined model was 0.934 (sensitivity = 0.808, specificity = 0.920, accuracy = 0.835), and its diagnostic efficiency was higher than that of junction smoothness (AUC=0.667, sensitivity = 0.654, specificity = 0.680, accuracy = 0.660), maximum longitudinal diameter (AUC=0.757, sensitivity = 0.833, specificity = 0.604, accuracy = 0.786), tumor-wall interface (AUC=0.888, sensitivity = 0.755, specificity = 0.808, accuracy = 0.816) and Arterial reinforcement rate (AUC=0.786, sensitivity = 0.936, specificity = 0.640, accuracy = 0.864). CONCLUSION: Above qualitative and quantitative indicators based on CTU and the combination of them may be helpful to the differential diagnosis of BUC and IPB, thus better assisting in clinical decision-making. KEY POINTS: 1. Bladder urothelial carcinoma (BUC) and inverted papilloma of the bladder (IPB) exhibit similar clinical symptoms and imaging presentations. 2. The diagnostic value of CT urography (CTU) in distinguishing between BUC and IPB has not been documented. 3. BUC and IPB differ in lesion size, growth pattern and blood supply. 4. The diagnostic efficiency is optimized by integrating multiple independent risk factors into the prediction model.

Building-Envelope-Inspired, Thermomechanically Robust All-Fiber Ceramic Meta-Aerogel for Temperature-Controlled Dominant Infrared Camouflage.

The unsatisfactory properties of ceramic aerogels when subjected to thermal shock, such as strength degradation and structural collapse, render them unsuitable for use at large thermal gradients or prolonged exposure to extreme temperatures. Here, a building-envelope-inspired design for fabricating a thermomechanically robust all-fiber ceramic meta-aerogel with interlocked fibrous interfaces and an interwoven cellular structure in the orthogonal directions is presented, which is achieved through a two-stage physical and chemical process. Inspired by the reinforced concrete building envelope, a solid foundation composed of fibrous frames is constructed and enhanced through supramolecular in situ self-assembly to achieve high compressibility, retaining over 90% of maximum stress under a considerable compressive strain of 50% for 10 000 cycles, and showing temperature-invariance when compressed at 60% strain within the range of -100 to 500 °C. As a result of its distinct response to oscillation tolerance coupled with elastic recovery, the all-fiber ceramic meta-aerogel exhibits exceptional suitability for thermal shock resistance and infrared camouflage performance in cold (-196 °C) and hot (1300 °C) fields. This study provides an opportunity for developing ceramic aerogels for effective thermal management under extreme conditions.

ZNF460-mediated circRPPH1 promotes TNBC progression through ITGA5-induced FAK/PI3K/AKT activation in a ceRNA manner.

BACKGROUND: Circular RNAs are highly stable regulatory RNAs that have been increasingly associated with tumorigenesis and progression. However, the role of many circRNAs in triple-negative breast cancer (TNBC) and the related mechanisms have not been elucidated. METHODS: In this study, we screened circRNAs with significant expression differences in the RNA sequencing datasets of TNBC and normal breast tissues and then detected the expression level of circRPPH1 by qRT‒PCR. The biological role of circRPPH1 in TNBC was then verified by in vivo and in vitro experiments. Mechanistically, we verified the regulatory effects between circRPPH1 and ZNF460 and between circRPPH1 and miR-326 by chromatin immunoprecipitation (ChIP), fluorescence in situ hybridization assay, dual luciferase reporter gene assay and RNA pull-down assay. In addition, to determine the expression of associated proteins, we performed immunohistochemistry, immunofluorescence, and western blotting. RESULTS: The upregulation of circRPPH1 in TNBC was positively linked with a poor prognosis. Additionally, both in vivo and in vitro, circRPPH1 promoted the biologically malignant behavior of TNBC cells. Additionally, circRPPH1 may function as a molecular sponge for miR-326 to control integrin subunit alpha 5 (ITGA5) expression and activate the focal adhesion kinase (FAK)/PI3K/AKT pathway. CONCLUSION: Our research showed that ZNF460 could promote circRPPH1 expression and that the circRPPH1/miR-326/ITGA5 axis could activate the FAK/PI3K/AKT pathway to promote the progression of TNBC. Therefore, circRPPH1 can be used as a therapeutic or diagnostic target for TNBC.

Enhanced N2 Adsorption and Activation by Combining Re Clusters and In Vacancies as Dual Sites for Efficient and Selective Electrochemical NH3 Synthesis.

The electrochemical N2 reduction reaction (NRR) is a green and energy-saving sustainable technology for NH3 production. However, high activity and high selectivity can hardly be achieved in the same catalyst, which severely restricts the development of the electrochemical NRR. In2Se3 with partially occupied p-orbitals can suppress the H2 evolution reaction (HER), which shows excellent selectivity in the electrochemical NRR. The presence of VIn can simultaneously provide active sites and confine Re clusters through strong charge transfer. Additionally, well-isolated Re clusters stabilized on In2Se3 by the confinement effect of VIn result in Re-VIn active sites with maximum availability. By combining Re clusters and VIn as dual sites for spontaneous N2 adsorption and activation, the electrochemical NRR performance is enhanced significantly. As a result, the Re-In2Se3-VIn/CC catalyst delivers a high NH3 yield rate (26.63 µg h-1 cm-2) and high FEs (30.8%) at -0.5 V vs RHE.

The transition issue among new nurses in China: A mediation model analysis.

AIM: To explore the impact and interrelated pathway of work environment, career adaptability, and social support on the transition process and outcomes among new nurses. BACKGROUND: The transition issue affecting new nurses has been discussed for many decades. However, the exact interplay of various factors influencing the transition process and outcomes needs further exploration. METHODS: A cross-sectional, descriptive survey design was employed, and a convenient sample of 1628 new nurses from 22 tertiary hospitals in China was surveyed between November 2018 and October 2019. Mediation model analysis was used to analyze the data, and the STROBE checklist was used to report the study. FINDINGS: The transition status mediated the effects of work environment, career adaptability and social support, and had a significantly positive influence on their intention to remain and job satisfaction. Among the influencing factors, the work environment had the most significant positive impact on both the intention to remain and job satisfaction. CONCLUSION: Work environment was found to be the most significant factor affecting both the transition status and outcomes of new nurses. The transition status played an important mediating role between the influencing factors and the transition outcomes, whereas career adaptability was found to mediate the impact of social support and work environment in the transition process. IMPLICATIONS FOR NURSING AND NURSING POLICIES: The results underscore the critical role of the work environment and demonstrate the mediating effects of transition status and career adaptability in the transition process of new nurses. Therefore, dynamic evaluation of the transition status should serve as the foundation for developing targeted supportive interventions. Such interventions should also focus on enhancing career adaptability and fostering a supportive work environment to facilitate the transition of new nurses.

Multiscale Interpenetrated/Interconnected Network Design Confers All-Carbon Aerogels with Unprecedented Thermomechanical Properties for Thermal Insulation under Extreme Environments.

With ultralight weight, low thermal conductivity, and extraordinary high-temperature resistance, carbon aerogels hold tremendous potential against severe thermal threats encountered by hypersonic vehicles during the in-orbit operation and re-entry process. However, current 3D aerogels are plagued by irreconcilable contradictions between adiabatic and mechanical performance due to monotonicity of the building blocks or uncontrollable assembly behavior. Herein, a spatially confined assembly strategy of multiscale low-dimensional nanocarbons is reported to decouple the stress and heat transfer. The nanofiber framework, a basis for transferring the loading strain, is covered by a continuous thin-film-like layer formed by the aggregation of nanoparticles, which in combination serve as the fundamental structural units for generating an elastic behavior while yielding compartments in aerogels to suppress the gaseous fluid thermal diffusion within distinct partitions. The resulting all-carbon aerogels with a hierarchical cellular structure and quasi-closed cell walls achieve the best thermomechanical and insulation trade-off, exhibiting flyweight density (24 mg cm-3 ), temperature-constant compressibility (-196-1600 °C), and a low thermal conductivity of 0.04 829 W m-1 K-1 at 300 °C. This strategy provides a remarkable thermal protection material in hostile environments for future aerospace exploration.

Direct synthesis of ultralight, elastic, high-temperature insulation N-doped TiO2 ceramic nanofibrous sponges via conjugate electrospinning.

The design of three-dimensional ceramic nanofibrous materials with high-temperature insulation and flame-retardant characteristics is of significant interest due to the effectively improved mechanical properties. However, achieving a pure ceramic monolith with ultra-low density, high elasticity and toughness remains a great challenge. Herein, a low-cost, scalable strategy to fabricate ultralight and mechanically robust N-doped TiO2 ceramic nanofibrous sponges with a continuous stratified structure by conjugate electrospinning is reported. Remarkably, the introduction of dopamine into the precursor nanofibers is engineered, which realizes the nitrogen doping to inhibit the TiO2 grain growth, endowing single nanofibers with a smoother, less defective surface. Besides, the self-polymerization process of dopamine allows the construction of bonding points between nanofibers and optimizes the distribution of inorganic micelles on polymer templates. Moreover, a rotating disk receiving device under different rotating speeds is designed to obtain N-doped TiO2 sponges with various interlamellar spacings, further affecting the maximum compressive deformation capacity. The resulting ceramic sponges, consisting of fluffy crosslinked nanofiber layers, possess low densities of 12-45 mg cm-3, which can quickly recover under a large strain of 80% and have only 9.2% plastic deformation after 100 compression cycles. In addition, the sponge also exhibits a temperature-invariant superelasticity at 25-800 °C and a low heat conductivity of 0.0285 W m-1 K-1, with an outstanding thermal insulation property, making it an ideal insulation material for high-temperature or harsh conditions.

Way to a Library of Ti-Series Oxide Nanofiber Sponges that are Highly Stretchable, Compressible, and Bendable.

Ti-series oxide ceramics in the form of aerogels, such as TiO2, SrTiO3, BaTiO3, and CaCu3Ti4O12, hold tremendous potential as functional materials owing to their excellent optical, dielectric, and catalytic properties. Unfortunately, these inorganic aerogels are usually brittle and prone to pulverization owing to weak inter-particulate interactions, resulting in restricted application performance and serious health risks. Herein, a novel strategy is reported to synthesize an elastic form of an aerogel-like, highly porous structure, in which activity-switchable Ti-series oxide sols transform from the metastable state to the active state during electrospinning, resulting in condensation and solidification at the whipping stage to obtain curled nanofibers. These curled nanofibers are further entangled when flying in the air to form a physically interlocked, elastic network mimicking the microstructure of high-elasticity hydrogels. This strategy provides a library of Ti-series oxide nanofiber sponges with unprecedented stretchability, compressibility, and bendability, possessing extensive opportunities for greener, safer, and broader applications as integrated or wearable functional devices. As a proof-of-concept demonstration, a new, elastic form of TiO2, composed of both "white" and "black" TiO2 nanofiber sponges, is constructed as spontaneous air-conditioning textiles in smart clothing, buildings, and vehicles, with unique bidirectional regulation of radiative cooling in summer and solar heating in winter.

Multiscale Synergetic Bandgap/Structure Engineering in Semiconductor Nanofibrous Aerogels for Enhanced Solar Evaporation.

Solar-driven interface evaporation has been identified as a sustainable seawater desalination and water purification technology. Nonetheless, the evaporation performance is still restricted by salt deposition and heat loss owing to weak solar spectrum absorption, tortuous channels, and limited plane area of conventional photothermal material. Herein, the semiconductor nanofibrous aerogels with a narrow bandgap, vertically aligned channels, and a conical architecture are constructed by the multiscale synergetic engineering strategy, encompassing bandgap engineering at the atomic scale and structure engineering at the nano-micro scale. As a proof-of-concept demonstration, a Co-doped MoS2 nanofibrous aerogel is synthesized, which exhibits the entire solar absorption, superhydrophilic, and excellent thermal insulation, achieving a net evaporation rate of 1.62 kg m-2 h-1 under 1 sun irradiation, as well as a synergistically efficient dye ion adsorption function. This work opens up new possibilities for the development of solar evaporators for practical applications in clean water production.

Scalable Synthesis of Flexible Single-Atom Monolithic Catalysts for High-Efficiency, Durable CO Oxidation at Low Temperature.

The creation of single-atom catalysts in a large-size, high-yield, and stable form represents an important direction for high-efficiency industrial catalysis in the future. Herein, we report a strategy to synthesize flexible single-atom monolithic catalysts (SAMCs) based on the hierarchical 3D assembly of single-atom-loaded oxide ceramic nanofibers. The nanofibers, which can be produced in a continuous and scalable manner, serve as an ideal support for single atoms spontaneously and almost completely exposed at the surface through the Kirkendall effect-enabled in situ ion migration during the spinning process, resulting in both high yield and large loading quantity. Moreover, the hierarchical 3D assembly of these nanofibers into a porous, flexible structure endows the SAMCs with the advantages of sufficient infiltration and oscillation tolerance when faced with high-throughput gaseous media, leading to both high catalytic efficiency and excellent durability. As a proof-of-concept demonstration, a Pt SAMC is synthesized, which exhibits 100% CO oxidation at low temperature (∼170 °C), excellent invariance toward high-frequency (10 Hz) oscillation, and high structural stability from 25 to 300 °C. This work is beneficial for the large-scale production of SAMCs in broad industrial applications.

Hydrogen Permeability of Polyamide 6 Used as Liner Material for Type IV On-Board Hydrogen Storage Cylinders.

As a commonly used liner material for fully reinforced, carbon-fiber-composite hydrogen storage cylinders, polyamide 6 (PA6) needs to meet the required hydrogen permeation index during use; otherwise, it may adversely affect the safe use of hydrogen storage cylinders. The hydrogen permeability of PA6 under different temperatures and pressures was tested, and the variations in its hydrogen permeability were investigated. Additionally, the hydrogen permeability of PA6, polyamide 11 (PA11), and high-density polyethylene (HDPE) at a temperature of 288 K and a pressure of 70 MPa was tested, and the differences in hydrogen permeability among these commonly used liner materials for type IV on-board hydrogen storage cylinders were studied. The results reported herein indicate that both the hydrogen permeability and diffusion coefficient of PA6 increase with rising test temperature but decrease with increasing pressure. The solubility coefficient of PA6 shows no significant change with varying test temperatures and pressures. At a test temperature of 288 K and a pressure of 70 MPa, among the three materials, PA6 has slightly stronger hydrogen permeation resistance than PA11, while HDPE has the least resistance. These research findings can serve as valuable reference data for evaluating the hydrogen permeability of liner materials.

Review of the Hydrogen Permeation Test of the Polymer Liner Material of Type IV On-Board Hydrogen Storage Cylinders.

Type IV hydrogen storage cylinders comprise a polymer liner and offer advantages such as lightweight construction, high hydrogen storage density, and good fatigue performance. However, they are also characterized by higher hydrogen permeability. Consequently, it is crucial for the polymer liner material to exhibit excellent resistance to hydrogen permeation. International organizations have established relevant standards mandating hydrogen permeation tests for the liner material of type IV on-board hydrogen storage cylinders. This paper provides a comprehensive review of existing research on hydrogen permeability and the hydrogen permeation test methods for the polymer liner material of type IV on-board hydrogen storage cylinders. By delving into the hydrogen permeation mechanism, a better understanding can be gained, offering valuable references for subsequent researchers in this field. This paper starts by thoroughly discussing the hydrogen permeation mechanism of the liner material. It then proceeds to compare and analyze the hydrogen permeation test methods specified by various standards. These comparisons encompass sample preparation, sample pretreatment, test device, test temperature and pressure, and qualification indicators. Then, this study offers recommendations aimed at enhancing the hydrogen permeation test method for the liner material. Additionally, the influence of test temperature, test pressure, and polymer material properties on the hydrogen permeability of the liner material is discussed. Finally, the influences of the test temperature, test pressure, and polymer material properties on the hydrogen permeability of the liner material are discussed. Future research direction on the hydrogen permeability and hydrogen permeation test method of the liner material of the type IV hydrogen storage cylinder has been prospected.

Inhibited Grain Growth Through Phase Transition Modulation Enables Excellent Mechanical Properties in Oxide Ceramic Nanofibers up to 1700 °C.

Oxide ceramics are widely used as thermal protection materials due to their excellent structural properties and earth abundance. However, in extremely high-temperature environments (above 1500 °C), the explosive growth of grain size causes irreversible damage to the microstructure of oxide ceramics, thus exhibiting poor thermomechanical stability. This problem, which may lead to catastrophic accidents, remains a great challenge for oxide ceramic materials. Here, a novel strategy of phase transition modulation is proposed to control the grain growth at high temperatures in oxide ceramic nanofibers, realizing effective regulation of the crystalline forms as well as the size uniformity of primary grains, and thus suppressing the malignant growth of the grains. The resulting oxide ceramic nanofibers have excellent mechanical strength and flexibility, delivering an average tensile strength as high as 1.02 GPa after being exposed to 1700 °C for 30 min, and can withstand thousands of flexural cycles without obvious damage. This work may provide new insight into the development of advanced oxide ceramic materials that can serve in extremely high-temperature environments with long-term durability.

High Toughness Combined with High Strength in Oxide Ceramic Nanofibers.

Traditional oxide ceramics are inherently brittle and highly sensitive to defects, making them vulnerable to failure under external stress. As such, endowing these materials with high strength and high toughness simultaneously is crucial to improve their performance in most safety-critical applications. Fibrillation of the ceramic materials and further refinement of the fiber diameter, as realized by electrospinning, are expected to achieve the transformation from brittleness to flexibility owing to the structural uniqueness. Currently, the synthesis of electrospun oxide ceramic nanofibers must rely on an organic polymer template to regulate the spinnability of the inorganic sol, whose thermal decomposition during ceramization will inevitably lead to pore defects, and seriously weaken the mechanical properties of the final nanofibers. Here, a self-templated electrospinning strategy is proposed for the formation of oxide ceramic nanofibers without adding any organic polymer template. An example is given to show that individual silica nanofibers have an ideally homogeneous, dense, and defect-free structure, with tensile strength as high as 1.41 GPa and toughness up to 34.29 MJ m-3 , both of which are far superior to the counterparts prepared by polymer-templated electrospinning. This work provides a new strategy to develop oxide ceramic materials that are strong and tough.

Fibrous MXene Aerogels with Tunable Pore Structures for High-Efficiency Desalination of Contaminated Seawater.

The seawater desalination based on solar-driven interfacial evaporation has emerged as a promising technique to alleviate the global crisis on freshwater shortage. However, achieving high desalination performance on actual, oil-contaminated seawater remains a critical challenge, because the transport channels and evaporation interfaces of the current solar evaporators are easily blocked by the oil slicks, resulting in undermined evaporation rate and conversion efficiency. Herein, we propose a facile strategy for fabricating a modularized solar evaporator based on flexible MXene aerogels with arbitrarily tunable, highly ordered cellular/lamellar pore structures for high-efficiency oil interception and desalination. The core design is the creation of 1D fibrous MXenes with sufficiently large aspect ratios, whose superior flexibility and plentiful link forms lay the basis for controllable 3D assembly into more complicated pore structures. The cellular pore structure is responsible for effective contaminants rejection due to the multi-sieving effect achieved by the omnipresent, isotropic wall apertures together with underwater superhydrophobicity, while the lamellar pore structure is favorable for rapid evaporation due to the presence of continuous, large-area evaporation channels. The modularized solar evaporator delivers the best evaporation rate (1.48 kg m-2 h-1) and conversion efficiency (92.08%) among all MXene-based desalination materials on oil-contaminated seawater.