Long noncoding RNA ZFAS1 exerts a suppressive impact on ferroptosis by modulating the miR-150/AIFM2 axis in hepatocellular carcinoma cells.

ZNFX1 Antisense RNA 1 (ZFAS1) act as an oncogenic long noncoding RNA in multiple types of cancer. Ferroptosis is an iron-dependent cell death characterized by excessive iron accumulation and lipid peroxidation. However, to date, the functional role and mechanism of ZFAS1 in ferroptosis in hepatocellular carcinoma (HCC) remains largely unknown. The present study revealed that ZFAS1 was upregulated in HCC and upregulation of ZFAS1 indicated poor clinical outcome of HCC patients. Loss- and gain-of-function experiments demonstrated that knockdown of ZFAS1 inhibited HCC cell proliferation and induced ferroptosis, while overexpression of ZFAS1 exerted opposite effects. ZFAS1 enhanced cell proliferation via suppression of ferroptotic death. Mechanistically, ZFAS1 interacted with miR-150 and decreased its expression. AIFM2, the critical ferroptosis protector, was a direct target of ZFAS1/miR-150. ZFAS1 accelerated HCC proliferation and inhibited ferroptosis by the regulation of the miR-150/AIFM2 axis. These discoveries intimate an essential part of ZFAS1/miR-150/AIFM2 in governing HCC ferroptosis, which may provide a promising therapeutic strategy for HCC patients.

Consistent Thermal Conductivities of Spring-Like Structured Polydimethylsiloxane Composites under Large Deformation.

Flexible and highly thermally conductive materials with consistent thermal conductivity (λ) during large deformation are urgently required to address the heat accumulation in flexible electronics. In this study, spring-like thermal conduction pathways of silver nanowire (S-AgNW) fabricated by 3D printing are compounded with polydimethylsiloxane (PDMS) to prepare S-AgNW/PDMS composites with excellent and consistent λ during deformation. The S-AgNW/PDMS composites exhibit a λ of 7.63 W m-1 K-1 at an AgNW amount of 20 vol%, which is ≈42 times that of PDMS (0.18 W m-1 K-1) and higher than that of AgNW/PDMS composites with the same amount and random dispersion of AgNW (R-AgNW/PDMS) (5.37 W m-1 K-1). Variations in the λ of 20 vol% S-AgNW/PDMS composites are less than 2% under a deformation of 200% elongation, 50% compression, or 180° bending, which benefits from the large deformation characteristics of S-AgNW. The heat-transfer coefficient (0.29 W cm-2 K-1) of 20 vol% S-AgNW/PDMS composites is ≈1.3 times that of the 20 vol% R-AgNW/PDMS composites, which reduces the temperature of a full-stressed central processing unit by 6.8 °C compared to that using the 20 vol% R-AgNW/PDMS composites as a thermally conductive material in the central processing unit.

Designing Symmetric Gradient Honeycomb Structures with Carbon-Coated Iron-Based Composites for High-Efficiency Microwave Absorption.

The impedance matching of absorbers is a vital factor affecting their microwave absorption (MA) properties. In this work, we controllably synthesized Material of Institute Lavoisier 88C (MIL-88C) with varying aspect ratios (AR) as a precursor by regulating oil bath conditions, followed by one-step thermal decomposition to obtain carbon-coated iron-based composites. Modifying the precursor MIL-88C (Fe) preparation conditions, such as the molar ratio between metal ions and organic ligands (M/O), oil bath temperature, and oil bath time, influenced the phases, graphitization degree, and AR of the derivatives, enabling low filler loading, achieving well-matched impedance, and ensuring outstanding MA properties. The MOF-derivatives 2 (MD2)/polyvinylidene Difluoride (PVDF), MD3/PVDF, and MD4/PVDF absorbers all exhibited excellent MA properties with optimal filler loadings below 20 wt% and as low as 5 wt%. The MD2/PVDF (5 wt%) achieved a maximum effective absorption bandwidth (EAB) of 5.52 GHz (1.90 mm). The MD3/PVDF (10 wt%) possessed a minimum reflection loss (RLmin) value of - 67.4 at 12.56 GHz (2.13 mm). A symmetric gradient honeycomb structure (SGHS) was constructed utilizing the high-frequency structure simulator (HFSS) to further extend the EAB, achieving an EAB of 14.6 GHz and a RLmin of - 59.0 dB. This research offers a viable inspiration to creating structures or materials with high-efficiency MA properties.

Interface-induced dual-pinning mechanism enhances low-frequency electromagnetic wave loss.

Improving the absorption of electromagnetic waves at low-frequency bands (2-8 GHz) is crucial for the increasing electromagnetic (EM) pollution brought about by the innovation of the fifth generation (5G) communication technology. However, the poor impedance matching and intrinsic attenuation of material in low-frequency bands hinders the development of low-frequency electromagnetic wave absorbing (EMWA) materials. Here we propose an interface-induced dual-pinning mechanism and establish a magnetoelectric bias interface by constructing bilayer core-shell structures of NiFe2O4 (NFO)@BiFeO3 (BFO)@polypyrrole (PPy). Such heterogeneous interface could induce distinct magnetic pinning of the magnetic moment in the ferromagnetic NFO and dielectric pinning of the dipole rotation in PPy. The establishment of the dual-pinning effect resulted in optimized impedance and enhanced attenuation at low-frequency bands, leading to better EMWA performance. The minimum reflection loss (RLmin) at thickness of 4.43 mm reaches -65.30 dB (the optimal absorption efficiency of 99.99997%), and the effective absorption bandwidth (EAB) can almost cover C-band (4.72 ~ 7.04 GHz) with low filling of 15.0 wt.%. This work proposes a mechanism to optimize low-frequency impedance matching with electromagnetic wave (EMW) loss and pave an avenue for the research of high-performance low-frequency absorbers.

Controlled establishment of advanced local high-entropy NiCoMnFe-based layered double hydroxide for zinc batteries and low-temperature supercapacitors.

The development of high-performance electrodes is essential for improving the charge storage performance of rechargeable devices. In this study, local high-entropy C, N co-doped NiCoMnFe-based layered double hydroxide (C/N-NiCoMnFe-LDH, C/N-NCMF) were designed using a novel method. Multi-component synergistic effects can dramatically modulate the surface electron density, crystalline structure, and band-gap of the electrode. Thus, the electrical conductivity, electron transfer, and affinity for the electrolyte can be optimized. Additionally, the C/N-NCMF yielded a high specific capacitance (1454F·g-1) at 1 A·g-1. The electrode also exhibited excellent cycling stability, with 62 % capacitance retention after 5000 cycles. Moreover, the assembled Zn||C/N-NCMF battery and the C/N-NCMF//AC hybrid supercapacitor yielded excellent energy densities of 63.1 and 35.4 Wh·kg-1 at power densities of 1000 and 825 W·kg-1, and superior cycling performance with 69 % and 88.7 % capacitance retention after 1000 and 30,000 cycles, respectively. Furthermore, the electrode maintained high electrochemical activity and stability and ensured high energy density, power density, and cycling stability of the rechargeable devices even at a low temperature (-20 °C). This study paves a new pathway for regulating the electrochemical performance of LDH-based electrodes.

Analysis of coastline changes under the impact of human activities during 1985-2020 in Tianjin, China.

The accurate evaluation of shoreline movement is a crucial aspect for managing highly dynamic coasts. This study employed Landsat TM and OLI data through the Digital Shoreline Analysis System model to quantify changes in the spatiotemporal distribution of Tianjin's coastline from 1985 to 2020. The results showed that the coastline length (CL) increased by 178 km and 151% over the past 36 years, with an average increase of 5.1 km/a. Accretion and erosion processes along the entire coast were observed at rates of 83.9% and 16.1%, respectively. Notably, the Tianjin Port Area and Nangang Industrial Zone showed remarkable changes in the shoreline in 2009. Night lights (NL) were used to display the intensity of human activity in this area, and the spatial heterogeneity of night light intensity was significant. Compared to the total night light (TNL) in 1985, it increased by 116% in 2020. The relationship between TNL and CL was then established and displayed a significant positive correlation (r = 0.91). With the increasing total night light, the growth of the CL presented changes with an initial slow increase, then rapid increase, and finally slow increase. In the second phase of TNL, the CL experienced a considerable increase due to anthropogenic activities such as land reclamation and port construction, fueled primarily by government policies during the period of 2005-2013. Subsequently, there was little change in the coastline. These findings provide valuable insights into spatiotemporal coastline monitoring programs and sustainable coastal management.

Mechanism of RBBP8-mediated homologous recombination repair in gastric cancer synthetic lethal.

Background: It is of great clinical significance to further explore new strategies and potential combined therapeutic targets for gastric cancer. This study aimed to investigate the synthetic lethal effect of RBBP8 molecular intervention combined with a poly ADP ribose polymerase (PARP) inhibitor in non-BRCA mutant gastric cancer and clarify the mechanism by which RBBP8 regulates homologous recombination repair. Methods: The role of RBBP8 in DNA damage repair was observed using bioinformatic analysis, western blot analysis, and immunofluorescence. The synthetic lethal effect was verified using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS)and flow cytometry apoptosis experiments. Results: Among the patients with gastric cancer treated with chemotherapy, the prognosis of patients with high RBBP8 expression levels was worse (homologous recombination [HR] = 1.54, p = 0.028). RBBP8 knockdown induced DNA damage and had a synergistic effect with PARP inhibitor treatment on cell viability inhibition and cell apoptosis in AGS (generic code for human gastric adenocarcinoma cells) (t = 11.154, p < 0.001) and N87 (t = 6.362, p < 0.001) cells. RBBP8 knockdown inhibited RAD51 activation and DNA terminal excision in homologous recombination repair. Conclusion: RBBP8 is involved in homologous recombination repair, and molecular intervention into RBBP8 could achieve a synthetic lethal effect with PARP inhibitor treatment in gastric cancer cells.

Electrochemical Performance of Corn Waste Derived Carbon Electrodes Based on the Intrinsic Biomass Properties.

The exploration of cost-effective and sustainable biomass-derived carbon materials as electrodes for energy conversion and storage has gained extensive attention in recent research studies. However, the selection of the biomass and the electrochemical performance regulation of the derived biochar, as well as their interrelationship still remain challenging for practical application. Herein, corn wastes with high carbon content (>40%), corn cob and corn silk, were selected as precursors for the preparation of high value-added and high yield carbon materials via a modified synthetic process. Uniquely, this work put emphasis on the theoretical and experimental investigations of how the biomass properties influence the composition and nanostructure regulation, the electrolyte ion adsorption free energy, and the electrical conductivity of the derived carbon materials as well as their electrochemical performance optimization. Owing to the favorable specific surface area, the hierarchical porous structure, and the diverse elemental distribution, corn cob and corn silk derived carbon materials (CBC and SBC) present great potential as promising electrodes for alkaline aqueous zinc batteries and supercapacitors. The assembled CBC//Zn and SBC//Zn zinc batteries deliver high energy densities of 63.0 Wh kg-1 and 39.1 Wh kg-1 at a power density of 575 W kg-1, with excellent cycling performance of 91.1% and 84.3% capacitance retention after 10,000 cycles. As for the assembled symmetric supercapacitors, high energy densities of 14.9 Wh kg-1 and 13.6 Wh kg-1, and superior long-term cycling stability of 99.3% and 96.6% capacitance retention after 20,000 cycles could be achieved. This study highlights the advantages of utilizing corn cob and corn silk as carbon sources on the designed synthesis of carbon electrodes, and presents a meaningful perspective in the investigation of biomass-derived carbon materials and their potential applications in rechargeable devices.

Advances and mechanisms in polymer composites toward thermal conduction and electromagnetic wave absorption.

Polymer composites have essential applications in electronics due to their versatility, stable performance, and processability. However, with the increasing miniaturization and high power of electronics in the 5G era, there are significant challenges related to heat accumulation and electromagnetic wave (EMW) radiation in narrow spaces. Traditional solutions involve using either thermally conductive or EMW absorbing polymer composites, but these fail to meet the demand for multi-functional integrated materials in electronics. Therefore, designing thermal conduction and EMW absorption integrated polymer composites has become essential to solve the problems of heat accumulation and electromagnetic pollution in electronics and adapt to its development trend. Researchers have developed different approaches to fabricate thermal conduction and EMW absorption integrated polymer composites, including integrating functional fillers with both thermal conduction and EMW absorption functions and innovating processing methods. This review summarizes the latest research progress, factors that affect performance, and the mechanisms of thermal conduction and EMW absorption integrated polymer composites. The review also discusses problems that limit the development of these composites and potential solutions and development directions. The aim of this review is to provide references for the development of thermal conduction and EMW absorption integrated polymer composites.

Delicate Design of ZnS@In2S3 Core-Shell Structures with Modulated Photocatalytic Performance under Simulated Sunlight Irradiation.

ZnS@In2S3 core-shell structures with high photocatalytic activity have been delicately designed and synthesized. The unique structure and synergistic effects of the composites have an important influence on the improvement of photocatalytic activity. The photocatalytic activity has been studied by photodegrading individual eosin B (EB) and the mixture solution consisting of eosin B and rhodamine B (EB-RhB) in the presence of hydrogen peroxide (H2O2) under simulated sunlight irradiation. The results show that all of the photocatalysts with different contents of In2S3 exhibit enhanced catalytic activity compared to pure ZnS for the degradation of EB and EB-RhB solution. When the theoretical molar ratio of ZnS to In2S3 was 1:0.5, the composite presents the highest photocatalytic efficiency, which could eliminate more than 98% of EB and 94% of EB-RhB. At the same time, after five cycles of photocatalytic tests, the photocatalytic efficiency could be about 96% for the degradation of the EB solution, and relatively high photocatalytic activity could also be obtained for the degradation of the EB-RhB mixed solution. This work has proposed a facile synthetic process to realize the controlled preparation of core-shell ZnS@In2S3 composites with effectively modulated structures and compositions, and the composites have also proved to be high-efficiency photocatalysts for the disposal of complicated pollutants.

Skillful Introduction of Urea during the Synthesis of MOF-Derived FeCoNi-CH/p-rGO with a Spindle-Shaped Substrate for Hybrid Supercapacitors.

A composite (FeCoNi-CH/p-rGO) with a spindle-shaped substrate is controllably prepared by combining FeCoNi carbonate hydroxide (FeCoNi-CH) and partially reduced graphite oxide (p-rGO) using a novel chemical strategy. In the synthetic process, urea is introduced as the precipitant and reducing agent. MIL-88A as a self-template is converted into a ternary-metal CH composite, maintaining the original morphology by the metal ion etching and coprecipitation method, and graphite oxide is reduced to rGO with stronger conductivity partially at the same time. The electrochemical performance of the FeCoNi-CH/p-rGO is superior to FeCoNi-CH, with a high specific capacitance (1346 F g-1 at 0.5 A g-1) and rate capability (55.5% at 10 A g-1). The better electrochemical performance of the FeCoNi-CH/p-rGO composite is attributed to the pseudocapacitive energy storage capacity caused by the synergistic action of ternary-metal CH and the high conductivity of p-rGO. Meanwhile, the uniform mixture of FeOOH/activated carbon (AC) is fabricated as an anode to instead of the pure FeOOH or AC, which leads to the balancing energy density and high cycle stability of the hybrid supercapacitor (HSC). The corresponding assembled FeCoNi-CH/p-rGO//FeOOH/AC HSC exhibits a high energy density of 46.93 W h kg-1 at 400 W kg-1 power density and a cycle stability of 66.7% after 3000 cycles. In addition, this work also provides a facile method to fabricate metal-organic framework-derived ternary-metal CH/p-rGO composite materials, which could be applied in the fields of supercapacitors and other fields.

Bioinspired High-Strength Montmorillonite-Alginate Hybrid Film: The Effect of Different Divalent Metal Cation Crosslinking.

The natural nacre has a regular ordered layered structure of calcium carbonate tablets and ion crosslinking proteins stacked alternately, showing outstanding mechanical properties. Inspired by nacre, we fabricated different divalent metal cation-crosslinked montmorillonite-alginate hybrid films (MMT-ALG-X2+; X2+ = Cu2+, Cd2+, Ba2+, Ca2+, Ni2+, Co2+ or Mn2+). The effect of ionic crosslinking strength and hydrogen bond interaction on the mechanical properties of the nacre-mimetics was studied. With the cations affinities with ALG being increased (Mn2+ < Co2+ = Ni2+ < Ca2+ < Ba2+ < Cd2+ < Cu2+), the tensile strength of nacre-mimetics showed two opposite influence trends: Weak ionic crosslinking (Mn2+, Co2+, Ni2+ and Ca2+) can synergize with hydrogen bonds to greatly increase the tensile properties of the sample; Strong ionic crosslinking (Ba2+, Cd2+, Cu2+) and hydrogen bonding form a competitive relationship, resulting in a rapid decrease in mechanical properties. Mn2+ crosslinking generates optimal strength of 288.0 ± 15.2 MPa with an ultimate strain of 5.35 ± 0.6%, obviously superior to natural nacre (135 MPa and 2%). These excellent mechanical properties arise from the optimum synergy of ion crosslinking and interfacial hydrogen bonds between crosslinked ALG and MMT nanosheets. In addition, these metal ion-crosslinked composite films show different colors, high visible transparency, and excellent UV shielding properties.

Application of a novel artificial neural network model in flood forecasting.

In this paper, a novel ANN flood forecasting model is proposed. The ANN model is combined with traditional hydrological concepts and methods, taking the initial Antecedent Precipitation Index (API), rainfall, upstream inflow and initial flow at the forecast river section as input of model, and flood flow forecast of the next time steps as output of the model. The distributed rainfall is realized as the input of the model. The simulation is processed by dividing the watershed into several rainfall-runoff processing units. Two hidden layers are used in the ANN, and the topology of ANN is optimized by connecting the hidden layer neurons only with the input which has physical conceptual causes. The topological structure of the proposed ANN model and its information transmission process are more consistent with the physical conception of rainfall-runoff, and the weight parameters of the model are reduced. The arithmetic moving-average algorithm is added to the output of the model to simulate the pondage action of the watershed. Satisfactory results have been achieved in the Mozitan and Xianghongdian reservoirs in the upper reaches of Pi river in Huaihe Basin, and the Fengman reservoir in the upper reach of Second Songhua river in Songhua basin in China.

3D Ultralight Hollow NiCo Compound@MXene Composites for Tunable and High-Efficient Microwave Absorption.

The 3D hollow hierarchical architectures tend to be designed for inhibiting stack of MXene flakes to obtain satisfactory lightweight, high-efficient and broadband absorbers. Herein, the hollow NiCo compound@MXene networks were prepared by etching the ZIF 67 template and subsequently anchoring the Ti3C2Tx nanosheets through electrostatic self-assembly. The electromagnetic parameters and microwave absorption property can be distinctly or slightly regulated by adjusting the filler loading and decoration of Ti3C2Tx nanoflakes. Based on the synergistic effects of multi-components and special well-constructed structure, NiCo layered double hydroxides@Ti3C2Tx (LDHT-9) absorber remarkably achieves unexpected effective absorption bandwidth (EAB) of 6.72 GHz with a thickness of 2.10 mm, covering the entire Ku-band. After calcination, transition metal oxide@Ti3C2Tx (TMOT-21) absorber near the percolation threshold possesses minimum reflection loss (RLmin) value of - 67.22 dB at 1.70 mm within a filler loading of only 5 wt%. This work enlightens a simple strategy for constructing MXene-based composites to achieve high-efficient microwave absorbents with lightweight and tunable EAB.

LncRNA MALAT1 Promote Cell Proliferation and Invasion by Sponging miR-125b to Modulate HMGA1 Expression in Laryngocarcinoma.

BACKGROUND: Laryngocarcinoma is the most frequent head and neck malignant tumor. MALAT1 have a role in promoting cell proliferation and metastasis in several tumors. This research aimed to investigate the great roles of MALAT1in laryngocarcinoma. METHODS: Overall, 54 cases of laryngocarcinoma tissues pathological specimens and paracancerous tissues were collected by surgical resection from the Department of Otolaryngology-Head and Neck Surgery at the Shandong Provincial Hospital affiliated to Shandong University, China from Jan 2012 to Oct 2015. The microRNA and protein levels of genes were evaluated by RT-qPCR and western blot. The proliferative and invasive ability were calculated usingCCK8 and transwell assays. Kaplan-Meier method was used to assess the survival of laryngocarcinoma patients. RESULTS: In laryngocarcinoma tissues and cells, lncRNA MALAT1 expression was significantly increased compared to normal tissues and cells. LncRNA MALAT1 promotes proliferation and migration of laryngocarcinoma cells. LncRNA MALAT1 upregulates HMGA1 expression by acting as a competitive endogenous RNA (ceRNA) for miR-125b. Rescue experiments showed that microRNA-125b inhibitor reversed the change in cell viability and invasion induced by sh-MALAT1. Down regulation of lncRNA MALAT1 inhibits laryngocarcinoma proliferation and invasion by modulating miR-125b/HMGA1. CONCLUSION: LncRNA MALAT1 promotes the development of laryngocarcinoma by regulating the expression level of HMGA1 by acting as a miR-125b ceRNA and may be considered as a new strategy for the development of laryngocarcinoma.

Delicate control of crystallographic Cu2O derived Ni-Co amorphous double hydroxide nanocages for high-performance hybrid supercapacitors: an experimental and computational investigation.

The reasonable design of the composition and hollow structure of electrode materials is beneficial for promoting the electrochemical properties and stability of electrode materials for high-performance supercapacitors, and it is of great significance to understand the inherent effect of these features on their performance. In this paper, the amorphous Ni-Co double hydroxide nanocages with hollow structures (Ni-Co ADHs) including quasi-sphere, cube and flower are delicately tailored via a Cu2O template-assisted approach. By combining experimental characterization and density functional theory (DFT) calculations, we systematically study the morphological growth of Cu2O templates under different conditions and the electrochemical performance of Ni-Co ADHs. Due to the coordination and synergistic effect between different components, the unique hollow structure and the nature of amorphous materials, Ni-Co ADHs deliver a high specific capacitance of 1707 F g-1 at 1 A g-1. The DFT calculations demonstrate that Ni-Co ADH nanocages exhibit an optimal redox reaction energy barrier and immensely promote the performance. In addition, a hybrid supercapacitor assembled with Ni-Co ADHs as a cathode and active carbon (AC) as an anode shows a high energy density of 33.8 W h kg-1 at a power density of 850 W kg-1 and exhibits an excellent cycling performance with a retention rate of 98% after 50 000 cycles. The successful synthesis of Ni-Co ADH nanocages, combined with rational computational simulations, indicates the excellent electrochemical performance and the potential utilization of amorphous hollow nanomaterials as electrodes for supercapacitors.

Circ_0003266 sponges miR-503-5p to suppress colorectal cancer progression via regulating PDCD4 expression.

BACKGROUND: Circular RNAs (circRNAs) feature prominently in tumor progression. However, the biological function and molecular mechanism of circ_0003266 in colorectal cancer (CRC) require further investigation. METHODS: Circ_0003266 expression in 46 pairs CRC tissues / adjacent tissues, and CRC cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR); after circ_0003266 was overexpressed or knocked down in CRC cells, cell proliferation, apoptosis, migration, and invasion were evaluated by the cell counting kit-8 (CCK-8), flow cytometry, and Transwell assays, respectively; the interaction among circ_0003266, miR-503-5p, and programmed cell death 4 (PDCD4) was confirmed using bioinformatics analysis and dual-luciferase reporter assay; PDCD4 protein expression in CRC cells was quantified using Western blot. RESULTS: Circ_0003266 was significantly lowly expressed in CRC tissues and cell lines. Circ_0003266 overexpression markedly repressed CRC cell proliferation, migration, and invasion, and accelerated the cell apoptosis, but its overexpression promoted the malignant phenotypes of CRC cells. PDCD4 was a direct target of miR-503-5p and circ_0003266 promoted PDCD4 expression by competitively sponging miR-503-5p. CONCLUSION: Circ_0003266 suppresses the CRC progression via sponging miR-503-5p and regulating PDCD4 expressions, which suggests that circ_0003266 may serve as a novel target for the treatment of CRC.

Graphene-wrapped pine needle-like cobalt nanocrystals constructed by cobalt nanorods for efficient microwave absorption performance.

Magnetic metal nanocrystals tend to be advanced microwave absorption substances as they possess simultaneous dielectric and magnetic losses. In this study, the metallic cobalt (Co) nanocrystals with a pine needle-like nanostructure constructed by one-dimensional Co nanorods have been successfully prepared through the polyol approach. By regulating the amount of reduced graphene oxide (rGO), rGO/Co nanocomposites with different mass ratios were acquired. Experimental results demonstrate that the rGO/Co nanocomposites display excellent microwave attenuation capacity. The minimum reflection loss value can reach -57.8 dB at 12.43 GHz with a filler loading of 20 wt% at 1.8 mm. Moreover, the effective absorption bandwidth covers the frequency range of 4.2-15.5 GHz with an integrated thickness of 1.5-4.0 mm. The main absorption mechanisms include dielectric loss caused by dipole and interfacial polarization and magnetic loss arising from ferromagnetic resonance and eddy current loss. In addition, the special nanostructure effect is also beneficial to improve the EM wave absorption performance.

Controllable synthesis of hollow spherical nickel chalcogenide (NiS2 and NiSe2) decorated with graphene for efficient supercapacitor electrodes.

New carbon-loaded nickel chalcogenide electrode materials (NiS2/GO and NiSe2/rGO) have been synthesized through an easy-to-operate process: NiSe2 was obtained based on NiS2 hollow spheres, and was successfully synthesized with l-cysteine assistance under the hydrothermal method at 120 °C. GO of different mass fraction was added together with l-cysteine. The electrochemical performance of NiS2/GO and NiSe2/rGO has been greatly improved because the formation of a carbon-loaded layer effectively increased the specific surface area and reduced the charge transport resistance. Compared with pure NiS2 and NiSe2, NiS2/GO and NiSe2/rGO presented much better specific capacitance (1020 F g-1 and 722 F g-1 respectively at a current density of 1 A g-1) and more superior rate capability (when the current density was raised to 5 A g-1 the specific capacitance remained at 569 F g-1 and 302 F g-1). This work highlights the advantages of nickel compounds through a very simple experimental method, and contributes to providing a good reference for preparation of superior supercapacitor materials with high performance.