In Situ Atomic Reconstruction Engineering Modulating Graphene-Like MXene-Based Multifunctional Electromagnetic Devices Covering Multi-Spectrum.

With the diversified development of big data, detection and precision guidance technologies, electromagnetic (EM) functional materials and devices serving multiple spectrums have become a hot topic. Exploring the multispectral response of materials is a challenging and meaningful scientific question. In this study, MXene/TiO2 hybrids with tunable conduction loss and polarization relaxation are fabricated by in situ atomic reconstruction engineering. More importantly, MXene/TiO2 hybrids exhibit adjustable spectral responses in the GHz, infrared and visible spectrums, and several EM devices are constructed based on this. An antenna array provides excellent EM energy harvesting in multiple microwave bands, with |S11| up to - 63.2 dB, and can be tuned by the degree of bending. An ultra-wideband bandpass filter realizes a passband of about 5.4 GHz and effectively suppresses the transmission of EM signals in the stopband. An infrared stealth device has an emissivity of less than 0.2 in the infrared spectrum at wavelengths of 6-14 µm. This work can provide new inspiration for the design and development of multifunctional, multi-spectrum EM devices.

Heterodimensional Structure Switching Multispectral Stealth and Multimedia Interaction Devices.

Lightweight and flexible electronic materials with high energy attenuation hold an unassailable position in electromagnetic stealth and intelligent devices. Among them, emerging heterodimensional structure draws intensive attention in the frontiers of materials, chemistry, and electronics, owing to the unique electronic, magnetic, thermal, and optical properties. Herein, an intrinsic heterodimensional structure consisting of alternating assembly of 0D magnetic clusters and 2D conductive layers is developed, and its macroscopic electromagnetic properties are flexibly designed by customizing the number of oxidative molecular layer deposition (oMLD) cycles. This unique heterodimensional structure features highly ordered spatial distribution, with an achievement of electron-dipole and magnetic-dielectric double synergies, which exhibits the high attenuation of electromagnetic energy (160) and substantial improvement of dielectric loss tangent (≈200%). It can respond to electromagnetic waves of different bands to achieve multispectral stealth, covering visible light, infrared radiation, and gigahertz wave. Importantly, two kinds of ingenious information interaction devices are constructed with heterodimensional structure. The hierarchical antennas allow precise targeting of operating bands (S- to Ku- bands) by oMLD cycles. The strain imaging device with high sensitivity opens a new horizon for visual interaction. This work provides a creative insight for developing advanced micro-nano materials and intelligent devices.

Two new species of the genus Norellisoma Wahlgren, 1917 (Diptera, Scathophagidae) from Yintiaoling Nature Reserve, Chongqing, China.

The known species of the genus Norellisoma from China are reviewed and two new species from Yintiaoling Nature Reserve in Chongqing City, where no other Norellisoma species are recorded, are described: Norellisomawuxiensesp. nov., Norellisomayintiaoensesp. nov. A key to the species of Norellisoma from China is provided.

Thermally Derived Hierarchical Nanoplates for Electromagnetic Protection and Waste Energy Recovery Device.

With the advent of intelligent society and the popularity of electronic equipment, the protection and treatment of electromagnetic (EM) radiation have become hot research topics all over the world. Herein, novel 2D carbon-based nanoplates with uniformly embedded Co nanoparticles are prepared, with unique hierarchical structure and integrated magnetic-dielectric components. The obtained hierarchical nanoplates exhibit a wide range of tunable EM properties (ε' for 3.38 to 34.67 and ε″ for 0.13 to 31.45) by manipulating the dispersed states inside wax system, which can achieve an effective switch from microwave absorption to EM interference shielding performance. The optimal reflection loss reaches -55.6 dB, and the shielding efficiency is 93.5%. Meanwhile, the hierarchical nanoplates also exhibit impressive capacitive performance, with a specific capacitance of 1654 F g-1 at 1 A g-1 . Based on this, a creative device is constructed with the nanoplates, which can convert harmful EM radiation to useful electric energy for recycling. This work offers a new idea for the development of EM materials and functional devices, powerfully promoting the advance of energy and environmental fields.

Ti3C2Txnanohybrids: tunable local conductive network and efficient EMI shielding performance for multifunctional materials and devices.

Ti3C2Txis an important member of the MXenes family. Due to its excellent electrical conductivity, adjustable atomic layer, and modifiable active surface, Ti3C2Txhas attracted great attention in the field of electromagnetic interference (EMI) shielding. This paper introduces the important role of regulating conductive network to improve the EMI shielding performance of materials and summarizes the EMI shielding performance of Ti3C2Txnanohybrids reported in recent years. In addition, Ti3C2Txbased EMI shielding materials towards multifunctional devices are also systematically introduced. After that, the development status of Ti3C2Txnanohybrids in the field of EMI shielding is objectively described, and the main problems and challenges are evaluated. Finally, the prospect of Ti3C2Txnanohybrids for advanced and green EMI shielding materials is forecasted.

Developing MXenes from Wireless Communication to Electromagnetic Attenuation.

There is an urgent global need for wireless communication utilizing materials that can provide simultaneous flexibility and high conductivity. Avoiding the harmful effects of electromagnetic (EM) radiation from wireless communication is a persistent research hot spot. Two-dimensional (2D) materials are the preferred choice as wireless communication and EM attenuation materials as they are lightweight with high aspect ratios and possess distinguished electronic properties. MXenes, as a novel family of 2D materials, have shown excellent properties in various fields, owing to their excellent electrical conductivity, mechanical stability, high flexibility, and ease of processability. To date, research on the utility of MXenes for wireless communication has been actively pursued. Moreover, MXenes have become the leading materials for EM attenuation. Herein, we systematically review the recent advances in MXene-based materials with different structural designs for wireless communication, electromagnetic interference (EMI) shielding, and EM wave absorption. The relationship governing the structural design and the effectiveness for wireless communication, EMI shielding, and EM wave absorption is clearly revealed. Furthermore, our review mainly focuses on future challenges and guidelines for designing MXene-based materials for industrial application and foundational research.

Selenium-Containing Protein From Selenium-Enriched Spirulina platensis Attenuates High Glucose-Induced Calcification of MOVAS Cells by Inhibiting ROS-Mediated DNA Damage and Regulating MAPK and PI3K/AKT Pathways.

Hyperglycemia is the main feature of diabetes and may increase the risk of vascular calcification (VC), which is an independent predictor for cardiovascular and cerebrovascular diseases (CCD). Selenium (Se) may decrease the risk of CCD, and previous studies confirmed that Se-containing protein from Se-enriched Spirulina platensis (Se-SP) exhibited novel antioxidant potential. However, the effect of Se-SP against VC has been not investigated. Herein, the protective effect and underlying mechanism of Se-SP against high glucose-induced calcification in mouse aortic vascular smooth muscle cells (MOVAS) were explored. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) results showed time-dependent uptake of Se-SP in MOVAS cells, which significantly inhibited high glucose-induced abnormal proliferation. Se-SP co-treatment also effectively attenuated high glucose-induced calcification of MOVAS cells, followed by decreased activity and expression of alkaline phosphatase (ALP). Further investigation revealed that Se-SP markedly prevented reactive oxygen species (ROS)-mediated DNA damage in glucose-treated MOVAS cells. ROS inhibition by glutathione (GSH) effectively inhibited high glucose-induced calcification, indicating that Se-SP could act as ROS inhibitor to inhibit high glucose-induced DNA damage and calcification. Moreover, Se-SP dramatically attenuated high glucose-induced dysfunction of mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase/AKT (PI3K/AKT) pathways. Se-SP after Se addition achieved enhanced potential in inhibiting high glucose-induced calcification, which validated that Se-SP as a new Se species could be a highly effective treatment for human CCD.

Assembling Nano-Microarchitecture for Electromagnetic Absorbers and Smart Devices.

Smart devices, nowadays, are inspiring the infinite vitality and possibilities of intelligent life, such as self-power electromagnetic (EM) nanogenerator and microsensor, smart window, thermally-driven EM absorber, interstellar energy deliverer, and so on. Herein, the latest and most impressive works of 3D nano-micro architectures and their smart EM devices are highly focused on. The most key information, including assembly strategy and mechanism, EM response, and approach-structure-function relationship, is extracted and well-organized with profundity and easy-to-understand approach. The merit and demerit are revealed by comparison. What's more, the brightest and most cutting-edge smart EM devices constructed by 3D nano-micro architectures are reported as highlights, and the device principles are deeply dissected. Finally, a profound and top comment on the fast-growing field as well as challenges are proposed, and the future directions are predicted intelligently.

Variable-Temperature Electron Transport and Dipole Polarization Turning Flexible Multifunctional Microsensor beyond Electrical and Optical Energy.

Humans are undergoing a fateful transformation focusing on artificial intelligence, quantum information technology, virtual reality, etc., which is inseparable from intelligent nano-micro devices. However, the booming of "Big Data" brings about an even greater challenge by growing electromagnetic radiation. Herein, an innovative flexible multifunctional microsensor is proposed, opening up a new horizon for intelligent devices. It integrates "non-crosstalk" multiple perception and green electromagnetic interference shielding only in one pixel, with satisfactory sensitivity and fast information feedback. Importantly, beneficial by deep insight into the variable-temperature electromagnetic response, the microsensor tactfully transforms the urgent threat of electromagnetic radiation into "wealth," further integrating self-power. This result will refresh researchers' realization of next-generation devices, ushering in a new direction for aerospace engineering, remote sensing, communications, medical treatment, biomimetic robot, prosthetics, etc.

A Nano-Micro Engineering Nanofiber for Electromagnetic Absorber, Green Shielding and Sensor.

HIGHLIGHTS: The role of electron transport characteristics in electromagnetic (EM) attenuation can be generalized to other EM functional materials. The integrated functions of efficient EM absorption and green shielding open the view of EM multifunctional materials. A novel sensing mechanism based on intrinsic EM attenuation performance and EM resonance coupling effect is revealed. It is extremely unattainable for a material to simultaneously obtain efficient electromagnetic (EM) absorption and green shielding performance, which has not been reported due to the competition between conduction loss and reflection. Herein, by tailoring the internal structure through nano-micro engineering, a NiCo2O4 nanofiber with integrated EM absorbing and green shielding as well as strain sensing functions is obtained. With the improvement of charge transport capability of the nanofiber, the performance can be converted from EM absorption to shielding, or even coexist. Particularly, as the conductivity rising, the reflection loss declines from - 52.72 to - 10.5 dB, while the EM interference shielding effectiveness increases to 13.4 dB, suggesting the coexistence of the two EM functions. Furthermore, based on the high EM absorption, a strain sensor is designed through the resonance coupling of the patterned NiCo2O4 structure. These strategies for tuning EM performance and constructing devices can be extended to other EM functional materials to promote the development of electromagnetic driven devices.

Natural borneol sensitizes human glioma cells to cisplatin-induced apoptosis by triggering ROS-mediated oxidative damage and regulation of MAPKs and PI3K/AKT pathway.

Context: Cisplatin-based chemotherapy was widely used in treating human malignancies. However, side effects and chemoresistance remains the major obstacle.Objective: To verify whether natural borneol (NB) can enhance cisplatin-induced glioma cell apoptosis and explore the mechanism.Materials and methods: Cytotoxicity of cisplatin and/or NB towards U251 and U87 cells were determined with the MTT assay. Cells were treated with 0.25-80 µg/mL cisplatin and/or 5-80 µM NB for 48 h. The effects of NB and/or cisplatin on apoptosis and cell cycle distribution were quantified by flow cytometric analysis. Protein expression was detected by western blotting. ROS generation was conducted by measuring and visualising an oxidation-sensitive fluorescein DCFH-DA.Results: NB synergistically enhanced the anticancer efficacy of cisplatin in human glioma cells. Co-treatment of 40 µg/mL NB and 40 µg/mL cisplatin significantly inhibited U251 cell viability from 100% to 28.2% and increased the sub-G1 population from 1.4% to 59.3%. Further detection revealed that NB enhanced cisplatin-induced apoptosis by activating caspases and triggering reactive oxygen species (ROS) overproduction as evidenced by the enhancement of green fluorescence intensity from 265% to 645%. ROS-mediated DNA damage was observed as reflected by the activation of ATM/ATR, p53 and histone. Moreover, MAPKs and PI3K/AKT pathways also contributed to co-treatment-induced U251 cell growth inhibition. ROS inhibition by antioxidants effectively improved MAPKs and PI3K/AKT functions and cell viability, indicating that NB enhanced cisplatin-induced cell growth in a ROS-dependent manner.Discussion and conclusions: Natural borneol had the potential to sensitise human glioma cells to cisplatin-induced apoptosis with potential application in the clinic.

Enhanced anticancer efficiency of doxorubicin against human glioma by natural borneol through triggering ROS-mediated signal.

Doxorubicin (DOX) as a first-line chemotherapeutic drug has been widely used for therapy of human cancers. However, side effects and chemo-resistance severely blocked its clinic application. Herein, natural borneol (NB) as a novel monoterpenoid chemosensitizer was found to have the potential to increase the blood brain barrier (BBB) permeability and intracellular uptake of DOX in vitro, and synergistically enhanced DOX-induced cytotoxicity in human glioma cells. NB treatment significantly potentiated DOX-induced G2/M cell cycle arrest by triggering reactive oxygen species (ROS)-mediated DNA damage. NB also enhanced DOX-induced dysfunction of MAPKs and PI3 K/AKT pathways. Furthermore, U251 human glioma xenograft growth in vivo was also effectively inhibited by combined treatment of DOX with NB through induction of G2/M-phase arrest and antiangiogenesis. Taken together, our finding validated that NB could act as novel chemosensitizer to enhance DOX-induced anticancer efficacy, and strategy of using NB and DOX could be a high efficient way in therapy of human cancers.

Induction of Apoptosis in Human Glioma Cells by Fucoxanthin via Triggering of ROS-Mediated Oxidative Damage and Regulation of MAPKs and PI3K-AKT Pathways.

Fucoxanthin, a natural carotenoid derived from algae, exhibits novel anticancer potential. However, fucoxanthin with high purity is hard to prepare, and the anticancer mechanism remains elusive. In the present study, fucoxanthin with high purity was prepared and purified from the marine microalgae Nitzschia sp. by silica-gel column chromatography (SGCC), and the underlying mechanism against human glioma cells was evaluated. The results showed that fucoxanthin time- and dose-dependently inhibited U251-human-glioma-cell growth by induction of apoptosis (64.4 ± 4.8, P < 0.01) accompanied by PARP cleavage and caspase activation (244 ± 14.2, P < 0.01). Mechanically, fucoxanthin time-dependently triggered reactive-oxygen-species (ROS)-mediated DNA damage (100 ± 7.38, P < 0.01), as evidenced by the phosphorylation activation of Ser1981-ATM, Ser428-ATR, Ser15-p53, and Ser139-histone. Moreover, fucoxanthin treatment also time-dependently caused dysfunction of MAPKs and PI3K-AKT pathways, as demonstrated by the phosphorylation activation of Thr183-JNK, Thr180-p38, and Thr202-ERK and the phosphorylation inactivation of Ser473-AKT. The addition of kinase inhibitors further confirmed the importance of MAPKs and PI3K-AKT pathways in fucoxanthin-induced cell-growth inhibition (32.5 ± 3.6, P < 0.01). However, ROS inhibition by the antioxidant glutathione (GSH) effectively inhibited fucoxanthin-induced DNA damage, attenuated the dysfunction of MAPKs and PI3K-AKT pathways, and eventually blocked fucoxanthin-induced cytotoxicity (54.3 ± 5.6, P < 0.05) and cell apoptosis (32.7 ± 2.5, P < 0.05), indicating that ROS production, an early apoptotic event, is involved in the fucoxanthin-mediated anticancer mechanism. Taken together, these results suggested that fucoxanthin induced U251-human-glioma-cell apoptosis by triggering ROS-mediated oxidative damage and dysfunction of MAPKs and PI3K-AKT pathways, which validated that fucoxanthin may be a candidate for potential applications in cancer chemotherapy and chemoprevention.

Unusual continuous dual absorption peaks in Ca-doped BiFeO3 nanostructures for broadened microwave absorption.

Electromagnetic absorption materials have received increasing attention owing to their wide applications in aerospace, communication and the electronics industry, and multiferroic materials with both polarization and magnetic properties are considered promising ceramics for microwave absorption application. However, the insufficient absorption intensity coupled with the narrow effective absorption bandwidth has limited the development of high-performance multiferroic materials for practical microwave absorption. To address such issues, in the present work, we utilize interfacial engineering in BiFeO3 nanoparticles via Ca doping, with the purpose of tailoring the phase boundary. Upon Ca-substitution, the co-existence of both R3c and P4mm phases has been confirmed to massively enhance both dielectric and magnetic properties via manipulating the phase boundary and the destruction of the spiral spin structure. Unlike the commonly reported magnetic/dielectric hybrid microwave absorption composites, Bi0.95Ca0.05FeO3 has been found to deliver unusual continuous dual absorption peaks at a small thickness (1.56 mm), which has remarkably broadened the effective absorption bandwidth (8.7-12.1 GHz). The fundamental mechanisms based on the phase boundary engineering have been discussed, suggesting a novel platform for designing advanced multiferroic materials with wide applications.

Multiscale Assembly of Grape-Like Ferroferric Oxide and Carbon Nanotubes: A Smart Absorber Prototype Varying Temperature to Tune Intensities.

Ideal electromagnetic attenuation material should not only shield the electromagnetic interference but also need strong absorption. Lightweight microwave absorber with thermal stability and high efficiency is a highly sought-after goal of researchers. Tuning microwave absorption to meet the harsh requirements of thermal environments has been a great challenge. Here, grape-like Fe3O4-multiwalled carbon nanotubes (MWCNTs) are synthesized, which have unique multiscale-assembled morphology, relatively uniform size, good crystallinity, high magnetization, and favorable superparamagnetism. The Fe3O4-MWCNTs is proven to be a smart microwave-absorber prototype with tunable high intensities in double belts in the temperature range of 323-473 K and X band. Maximum absorption in two absorbing belts can be simultaneously tuned from ∼-10 to ∼-15 dB and from ∼-16 to ∼-25 dB by varying temperature, respectively. The belt for reflection loss ≤-20 dB can almost cover the X band at 323 K. The tunable microwave absorption is attributed to effective impedance matching, benefiting from abundant interfacial polarizations and increased magnetic loss resulting from the grape-like Fe3O4 nanocrystals. Temperature adjusts the impedance matching by changing both the dielectric and magnetic loss. The special assembly of MWCNTs and magnetic loss nanocrystals provides an effective pathway to realize excellent absorbers at elevated temperature.

NiO hierarchical nanorings on SiC: enhancing relaxation to tune microwave absorption at elevated temperature.

We fabricated NiO nanorings on SiC, a novel hierarchical architecture, by a facile two-step method. The dielectric properties depend on temperature and frequency in the range from 373 to 773 K and X band. The imaginary part and loss tangent increase more than four times and three times with increasing temperature, respectively. The architecture demonstrates multirelaxation and possesses high-efficient absorption. The reflection loss exceeds -40 dB and the bandwidth covers 85% of X band (approximately -20 dB). The synergistic effect between multirelaxation and conductance is beneficial to the microwave absorption. Our findings provide a novel and feasible strategy to tune microwave absorption.

Enhanced microwave absorption property of reduced graphene oxide (RGO)-MnFe2O4 nanocomposites and polyvinylidene fluoride.

MnFe2O4 nanoparticles have been synthesized on a large scale by a simple hydrothermal process in a wild condition, and the RGO/MnFe2O4 nanocomposites were also prepared under ultrasonic treatment based on the synthesized nanoparticles. The absorption properties of MnFe2O4/wax, RGO/MnFe2O4/wax and the RGO/MnFe2O4/PVDF (polyvinylidene fluoride) composites were studied; the results indicated that the RGO/MnFe2O4/PVDF composites show the most excellent wave absorption properties. The minimum reflection loss of RGO/MnFe2O4/PVDF composites with filler content of 5 wt % can reach -29.0 dB at 9.2 GHz, and the bandwidth of frequency less than -10 dB is from 8.00 to 12.88 GHz. The wave absorbing mechanism can be attributed to the dielectric loss, magnetic loss and the synergetic effect between RGO+MnFe2O4, RGO+PVDF and MnFe2O4+PVDF.