Multifunctional Conductive Hydrogel Composites with Nickel Nanowires and Liquid Metal Conductive Highways.

The dramatic growth of smart wearable electronics has generated a demand for conductive hydrogels due to their tunability, stimulus responsiveness, and multimodal sensing capabilities. However, the substantial trade-off between mechanical and electrical properties hinders their multifunctionality. Here, we report a double-network hydrogel composite that features a conductive "highway" constructed using magnetic-field-aligned nickel nanowires and liquid metal. The liquid metal fills the gaps between the aligned nickel nanowires. Such interconnected structures can form efficient conductive paths at low filler content, resulting in high conductivity (1.11 × 104 S/m) and mechanical compliance (Young's modulus, 89 kPa; toughness, 721 kJ/m3). When used as a wearable sensor, the hydrogel displays a high sensitivity and fast response for wireless motion detection and human-machine interaction. Furthermore, by exploiting its outstanding conductivity and electrical heating capacity, the hydrogel integrates electromagnetic shielding and thermal management functionalities. Owing to these all-around properties, our design offers a broader platform for expanding hydrogel applications.

A Novel Induction-Type Pressure Sensor based on Magneto-Stress Impedance and Magnetoelastic Coupling Effect for Monitoring Hand Rehabilitation.

Visualization of training effectiveness is critical to patients' confidence and eventual rehabilitation. Here, an innovative magnetoinductive pressure sensor is proposed for monitoring hand rehabilitation in stroke hemiplegic patients. It couples the giant magneto and stress-impedance effects of a square spiral amorphous wire with the giant magnetoelastic effect of a polymer magnet (NdFeB@PDMS). The addition of the magnetoelastic layer results in a sensitivity improvement of 178%, a wide sensing range (up to 1 MPa), fast response/recovery times (40 ms), and excellent mechanical robustness (over 15 000 cycles). Further integration with an LC oscillation circuit enables frequency adjustment into the MHz range resulting in a sensitivity of 6.6% kPa-1 and outstanding linearity (R2 =  0.99717) over a stress range of up to 100 kPa. When attached to a commercial split-fingerboard, the sensor is capable of dynamically monitoring the force in each finger, providing a reading of the rehabilitation process. Unlike conventional inductive sensors, the sensor is based on an inductive force-responsive material (amorphous wire), which significantly boosts the sensitivity. The approach also demonstrates the potential of magnetoelasticity in static pressure sensing, which is highly sensitive to dynamic pressure only through electromagnetic induction. This makes it more suitable for long-term and continuous human health monitoring.

Boosting Interfacial Polarization Through Heterointerface Engineering in MXene/Graphene Intercalated-Based Microspheres for Electromagnetic Wave Absorption.

Multi-layer 2D material assemblies provide a great number of interfaces beneficial for electromagnetic wave absorption. However, avoiding agglomeration and achieving layer-by-layer ordered intercalation remain challenging. Here, 3D reduced graphene oxide (rGO)/MXene/TiO2/Fe2C lightweight porous microspheres with periodical intercalated structures and pronounced interfacial effects were constructed by spray-freeze-drying and microwave irradiation based on the Maxwell-Wagner effect. Such approach reinforced interfacial effects via defects introduction, porous skeleton, multi-layer assembly and multi-component system, leading to synergistic loss mechanisms. The abundant 2D/2D/0D/0D intercalated heterojunctions in the microspheres provide a high density of polarization charges while generating abundant polarization sites, resulting in boosted interfacial polarization, which is verified by CST Microwave Studio simulations. By precisely tuning the 2D nanosheets intercalation in the heterostructures, both the polarization loss and impedance matching improve significantly. At a low filler loading of 5 wt%, the polarization loss rate exceeds 70%, and a minimum reflection loss (RLmin) of -67.4 dB can be achieved. Moreover, radar cross-section simulations further confirm the attenuation ability of the optimized porous microspheres. These results not only provide novel insights into understanding and enhancing interfacial effects, but also constitute an attractive platform for implementing heterointerface engineering based on customized 2D hierarchical architectures.

Thermally Stable Silicone Elastomer Composites Based on MoS2@Biomass-Derived Carbon with a High Dielectric Constant and Ultralow Loss for Flexible Microwave Electronics.

With the miniaturization and integration of electronic components in wireless communication and wearable devices, the demand for low-cost flexible composites with temperature-stable high dielectric constant and low loss has substantially increased. However, such comprehensive properties are fundamentally difficult to combine for conventional conductive and ceramic composites. Here, we develop silicone elastomer (SE) composites based on hydrothermally grown MoS2 on tissue paper-derived cellulose carbon (CC). Such design promoted the formation of microcapacitors, multiple interfaces, and defects reinforcing interfacial and defect polarizations and resulting in a high dielectric constant of 9.83 at 10 GHz with low filler loading of 15 wt %. Unlike highly conductive fillers, MoS2@CC with low conductivity ensured a very low loss tangent of 7.6 × 10-3, which was also influenced by the filler dispersion and adhesion to the matrix. Apart from breaking the typical conflict between high dielectric constant and low losses of traditional conductive composites, MoS2@CC SE composites were highly flexible with temperature-stable dielectric properties making them attractive as flexible substrates in microstrip antenna applications and extreme environment electronics. Moreover, recycling from waste tissue paper makes them potential candidates as low-cost and sustainable dielectric composites.

Plasmonic Biosensors with Nanostructure for Healthcare Monitoring and Diseases Diagnosis.

Nanophotonics has been widely utilized in enhanced molecularspectroscopy or mediated chemical reaction, which has major applications in the field of enhancing sensing and enables opportunities in developing healthcare monitoring. This review presents an updated overview of the recent exciting advances of plasmonic biosensors in the healthcare area. Manufacturing, enhancements and applications of plasmonic biosensors are discussed, with particular focus on nanolisted main preparation methods of various nanostructures, such as chemical synthesis, lithography, nanosphere lithography, nanoimprint lithography, etc., and describing their respective advances and challenges from practical applications of plasmon biosensors. Based on these sensing structures, different types of plasmonic biosensors are summarized regarding detecting cancer biomarkers, body fluid, temperature, gas and COVID-19. Last, the existing challenges and prospects of plasmonic biosensors combined with machine learning, mega data analysis and prediction are surveyed.

Material-structure integrated design for ultra-broadband all-dielectric metamaterial absorber.

Material and structure are the essential elements of all-dielectric metamaterials. Structure design for specific dielectric materials has been studied while the contribution of material and synergistic effect of material and structure have been overlooked in the past years. Herein, we propose a material-structure integrated design (MSID) methodology for all-dielectric metamaterials, increasing the degree of freedom in the metamaterial design, to comprehensively optimize microwave absorption performance and further investigate the contribution of material and structure to absorption. A dielectric metamaterial absorber with an ultra-broadband absorption from 5.3 to 18.0 GHz is realized. Theoretical calculation and numerical simulation demonstrate that the symphony of material and structure excites multiple resonance modes encompassing quarter-wavelength interference cancellation, spoof surface plasmon polariton mode, dielectric resonance mode and grating mode, which is essential to afford the desirable absorption performance. This work highlights the superiority of coupling of material and structure and provides an effective design and optimization strategy for all-dielectric metamaterial absorbers.

Ultralight reduced graphene oxide aerogels prepared by cation-assisted strategy for excellent electromagnetic wave absorption.

In this work, to maximize the unique attributes of reduced graphene oxide (RGO) for excellent microwave absorption, the ultralight RGO aerogels with improved dispersion and interface polarization performance were fabricated via a facile cation-assisted hydrothermal treatment process. The prepared RGO/paraffin composite exhibits excellent microwave absorption (MA) performance in a wideband frequency range of 8.0 ∼ 18.0 GHz with an ultralow absorbent content of 0.5 wt.%. Such performance is comparable with most previously reported results on RGO-based composites but required much higher absorbent content. The mechanisms for the enhancement of polarization relaxation loss and conductive loss were investigated in detail. This study provides a promising and facile method for preparing RGO-based excellent microwave absorption materials with ultra-low filler content, which is significant for designing efficient MA absorbers.

The Electromagnetic Absorption of a Na-Ethylenediamine Graphite Intercalation Compound.

A sodium-ethylenediamine graphite intercalation compound (Na(ethylenediamine)C15: "GIC") made from graphite flakes was used to study the microwave absorption performance of a GIC for the first time. Compared with the pristine graphite flakes, the neighboring layers in this GIC are pillared by Na(ethylenediamine)+ and possess a larger layer distance and improved electrical conductivity. Owing to the electrical conductivity of this GIC, only half of the loading content, compared to graphite flakes, is needed to achieve an outstanding absorption of -75.6 dB at 9.25 GHz (10.0 wt % GIC in paraffin in a 4.0 mm thick sample), but for graphite, 20.0 wt % is required for an absorption of -37.6 dB.

Dataset on comparable magnetocaloric properties of melt-extracted Gd36Tb20Co20Al24 metallic glass microwires.

The data in this article is the supplementary data of the research article entitled "Comparable magnetocaloric properties of melt-extracted Gd36Tb20Co20Al24 metallic glass microwires" (Yin et al., 2020). The data shows the circular cross section of Gd36Tb20Co20Al24 metallic glass microwires with a diameter of ∼55 µm. The data also shows that the chemical compositions of microwires are basically uniform on macro-scale and micro-scale.

Microwave Properties of Metacomposites Containing Carbon Fibres and Ferromagnetic Microwires.

The microwave properties of composites containing Fe-based ferromagnetic microwires and carbon fibres have been investigated as part of a campaign to bring added functionalities into structural composites. A transmission window observed in 1-6 GHz demonstrates double-negative (DNG), i.e., metamaterial characteristics in the composites containing short-cut carbon fibres and a parallel array of microwires; the metamaterial characteristic is due to the ferromagnetic resonance and a plasmonic behaviour, as short carbon fibres are proved to ameliorate DNG properties through enhancing the impedance of the composites. In parallel, magnetically tunable metamaterial features are realised in composites containing continuous carbon fibres and microwires, which can be switched on/off via rotating the electrical excitation direction. Such structural composites integrated with metamaterial features (termed as metacomposites) are potentially useful for active cloaking applications among others.

Engineering Graphene Wrinkles for Large Enhancement of Interlaminar Friction Enabled Damping Capability.

Graphene nanoplates are hoped-for solid lubricants to reduce friction and energy dissipation in micro and nanoscale devices benefiting from their interface slips to reach an expected superlubricity. On the contrary, we propose here by introducing engineered wrinkles of graphene nanoplates to exploit and optimize the interfacial energy dissipation mechanisms between the nanoplates in graphene-based composites for enhanced vibration damping performance. Polyurethane (PU) beams with designed sandwich structures have been successfully fabricated to activate the interlaminar slips of wrinkled graphene-graphene, which significantly contribute to the dissipation of vibration energy. These engineered composite materials with extremely low graphene content (∼0.08 wt %) yield a significant increase in quasi-static and dynamic damping compared to the baseline PU beams (by 71% and 94%, respectively). Friction force images of wrinkled graphene oxide (GO) nanoplates detected via an atomic force microscope (AFM) indicate that wrinkles with large coefficients of friction (COFs) indeed play a dominant role in delaying slip occurrences. Reduction of GO further enhances the COFs of the interacting wrinkles by 7.8%, owing to the increased effective contact area and adhesive force. This work provides a new insight into how to design graphene-based composites with optimized damping properties from the microstructure perspective.

ZEB1 promotes tumorigenesis and metastasis in hepatocellular carcinoma by regulating the expression of vimentin.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and its prognosis remains poor. Epithelial­to­mesenchymal transition (EMT)­induced markers have emerged as key regulators of tumor development and progression in HCC. The aim of the present study was to investigate the role of zinc finger E­box­binding homeobox 1 (ZEB1) in the tumorigenesis of HCC and to elucidate the mechanism underlying the correlation between ZEB1 and vimentin (VIM). The expression levels of ZEB1 and VIM were assessed by immunohistochemistry, western blotting and reverse transcription­quantitative polymerase chain reaction analysis in HCC tissues and cell lines. The biological significance of ZEB1 was examined by downregulating the expression of ZEB1 in Huh­7 cells. A luciferase reporter assay was used to investigate the association between ZEB1 and VIM. The expression levels of ZEB1 and VIM were higher in tumor tissues compared with those in adjacent normal tissues, and they were significantly associated with a poor prognosis in patients with HCC, whereas ZEB1 silencing led to the attenuation of HCC cell proliferation, invasion and migration. Furthermore, it was observed that ZEB1 was able to bind to a certain site in the VIM promoter and regulate the transcriptional activity of VIM. Therefore, the present study demonstrated that ZEB1 is a potential biomarker of the tumorigenesis and progression of HCC, and it may regulate transcription of the VIM gene.

Interface Probing by Dielectric Frequency Dispersion in Carbon Nanocomposites.

Interfaces remain one of the major issues in limiting the understanding and designing of polymer nanocomposites due to their complexity and pivotal role in determining the ultimate composites properties. In this study, we take multi-walled carbon nanotubes/silicone elastomer nanocomposites as a representative example, and have for the first time studied the correlation between high-frequency dielectric dispersion and static/dynamic interfacial characteristics. We have found that the interface together with other meso-structural parameters (volume fraction, dispersion, agglomeration) play decisive roles in formulating the dielectric patterns. The calculation of the relaxation times affords the relative importance of interfacial polarization to dipolar polarization in resultant dielectric relaxation. Dielectric measurements coupled with cyclic loading further reveals the remarkable capability of dielectric frequency dispersion in capturing the evolution of interfacial properties, such as a particular interface reconstruction process occurred to the surfactant-modified samples. All these results demonstrate that high-frequency dielectric spectroscopy is instrumental to probing both static and dynamic meso-structural characteristics, especially effective for the composites with relative weak interfaces which remains a mission impossible for many other techniques. The insights provided here based on the analyses of dielectric frequency dispersion will pave the way for optimized design and precise engineering of meso-structure in polymer nanocomposites.

Facile approach for a robust graphene/silver nanowires aerogel with high-performance electromagnetic interference shielding.

Robust graphene/silver nanowires (AgNWs) hybrid aerogels were fabricated by facile processes including mixing directly, reducing, and ambient pressure drying. The mechanical properties and electromagnetic interference (EMI)-shielding performance of the resultant hybrid aerogels were investigated in detail. Because silver nanowires with a high aspect ratio have been acting as crosslinkers to bridge two-dimensional graphene sheets, a highly porous and electrically conducting framework can resist high external loading to prevent major deformation and act as an express way for electron transport. Consequently, the hybrid aerogel exhibits large mechanical strength of 42 kPa, 35 times larger than that of the neat reduced graphene oxide aerogel (1.2 kPa), which can resist great damage. More importantly, the as-prepared aerogel possesses high EMI-shielding performance of up to ∼45.2 dB due to its unique nanostructure and good electrical properties. These results indicate that graphene/AgNWs hybrid aerogel prepared using this simplified method promises to be an ideal functional component for mechanically robust and high-performance EMI-shielding nanocomposites.

Prognostic role of long noncoding RNA ZFAS1 in cancer patients: a systematic review and meta-analysis.

Long noncoding RNA ZFAS1 has been identified as a crucial role in the tumorigenesis of malignant tumors. Numerous studies reported that the expression levels of ZFAS1 in tumor tissues were dramatically higher than that in adjacent normal tissues. We conducted a meta-analysis to investigate the correlation between ZFAS1 expression and clinical outcomes of cancer patients. The databases of PubMed, EMBASE, Web of Science, Cochrane Library, CNKI and WanFang were retrieved for eligible studies. A total of 841 patients from 9 studies were eventually included. Our results demonstrated that increased ZFAS1 expression was significantly associated with poor OS in cancer patients (HR = 2.13, 95% CI = 1.71-2.65, P < 0.001). Patients with high ZFAS1 expression presented shorter RFS than those with low ZFAS1 expression (HR = 2.00, 95% CI = 1.45-2.77, P < 0.001). The clinicopathological parameters analysis demonstrated that increased ZFAS1 expression was significantly associated with vascular invasion (OR = 2.26, 95% CI = 1.36-3.78, P = 0.002), lymph node metastasis (OR = 2.98, 95% CI = 2.12-4.19, P < 0.001) and advanced TNM stage (OR = 3.00, 95% CI = 2.18-4.12, P < 0.001). In conclusion, lncRNA ZFAS1 might serve as a prognostic biomarker for cancer patients and increased ZFAS1 expression may be closely related to advanced characteristics of cancer.

Small nucleolar RNA 47 promotes tumorigenesis by regulating EMT markers in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is third leading cause of cancer-related death globally. Evidence suggest that small nucleolar RNAs (snoRNAs) have emerged as key regulators of tumor development and progression in HCC. However, the biological significance of snoRNAs in HCC remains unclear. METHODS: We investigated the role of snoRA47 in a total of 60 paired HCC samples and six different human HCC cell lines by using qRT-PCR. Besides, snoRA47 was silenced through the siRNA transfection to determine whether snoRA47-siRNA is able to affect cell proliferation, invasion and metastasis by regulating the expressions of "epithelial-mesenchymal transition'' (EMT) markers. RESULTS: The expression of snoRA47 in HCC tissues was significantly higher than that in adjacent normal tissues (non-diseased tissues) and it was remarkably associated with intrahepatic metastasis, lymphatic invasion, and TNM stage. The Kaplan-Meier survival curves suggested that HCC patients with high snoRA47 expression experienced significantly shorter overall survival and statistically higher recurrence rate than those with low expression of snoRA47. In addition, it was proved that the knockdown of snoRA47 inhibited cell proliferation by inducing cell apoptosis and suppressed cell invasion and migration by regulating the expressions of EMT markers. CONCLUSIONS: SnoRA47 may serve as a valuable biomarker and a potential therapeutic target for HCC.

Stability and pH-independence of nano-zero-valent iron intercalated montmorillonite and its application on Cr(VI) removal.

Composite of nano-zero-valent iron and montmorillonite (NZVI/MMT) was prepared by inserting NZVI into the interlayer of montmorillonite. The unique structure montmorillonite with isolated exchangeable Fe(III) cations residing near the sites of structural negative charges inhibited the agglomeration of ZVI and result in the formation of ZVI particles in the montmorillonite interlayer regions. NZVI/MMT was demonstrated to possess large specific surface area and outstanding reducibility that encourage rapid and stable reaction with Cr (VI). Besides, the intercalation also makes NZVI well dispersed and more stable in the interlayer, thereby improving the reaction capacity by 16 times. The effects of pH value, initial concentration of Cr (VI) and reaction time on Cr (VI) removal have also been investigated in detail. According to PXRD and XPS characterization, NZVI/Cr (VI) redox reaction occurred in the interlayer of MMT. The study of NZVI/MMT is instrumental to the development of remediation technologies for persistent environmental contaminants.

Micro-electrolysis of Cr (VI) in the nanoscale zero-valent iron loaded activated carbon.

In this paper we prepared a novel material of activated carbon/nanoscale zero-valent iron (C-Fe(0)) composite. The C-Fe(0) was proved to possess large specific surface area and outstanding reducibility that result in the rapid and stable reaction with Cr (VI). The prepared composite has been examined in detail in terms of the influence of solution pH, concentration and reaction time in the Cr (VI) removal experiments. The results showed that the C-Fe(0) formed a micro-electrolysis which dominated the reaction rate. The Micro-electrolysis reaches equilibrium is ten minutes. Its reaction rate is ten times higher than that of traditional adsorption reaction, and the removal rate of Cr reaches up to 99.5%. By analyzing the obtained profiles from the cyclic voltammetry, PXRD and XPS, we demonstrate that the Cr (VI) is reduced to insoluble Cr (III) compound in the reaction.