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The reaction pathways to synthesize Zr2P2 WO12 ( ZPW) from ZrO2, WO3, and P2O5 are studied. It is found that there exist two different reaction pathways: One is direct reaction, while another is through an intermediate phase ZrP2O7. The reaction pathways are determined by drying and sintering temperatures. By controlling the reaction pathways, namely avoiding the intermediate phase, negative thermal expansion ceramic ZPW can be synthesized within several minutes. Besides, as-synthesized specimens possess much smaller and uniform grain size distribution than those synthesized by conventional methods. The investigation paves a way toward rapid and environmental friendly synthesis of ZPW and related compounds. [ABSTRACT FROM AUTHOR]

• An all-dielectric silicon nanostructure based on anapole mode is proposed, and its numerical study and analysis are carried out. • By manipulating the anapole mode and using the mirror reflection effect of metal, the electromagnetic field of the structure is enhanced to 125 times, which can be compared with the metal plasmon structure. • When the metal is used as the substrate, an ultranarrow perfect absorption with a linewidth of only 1.38 nm is obtained at the resonant wavelength, and the corresponding Q factor is as high as 602. Its performance is better than many published structures. Compared with the plasmon resonance suppressed by ohmic loss, high refractive index dielectric metamaterials have become a new frontier of nanophotonics because of their small loss. In this work, we numerically simulate the structures of Si and slotted Si nanodisk with the SiO 2 substrate, and slotted Si nanodisk with the Ag substrate. The slotted Si nanodisk excited with anapole mode reveals strong near field enhancement about 70 times in slotted gap regions. When the slotted Si nanodisk deposited on Ag substrate separated by SiO 2 layer, the designed structure shows the ultranarrow perfect absorption with the line width of 1.38 nm and the quality factor of 602, and the corresponding electric field enhancement in the Si nanodisk increases to 125. Our work provides a new idea for electric field enhancement and ultranarrow perfect absorption based on manipulation of anapole mode in dielectric metamaterials, and provides potential applications in optical sensors, nonlinear optics and surface enhanced Raman scattering. [ABSTRACT FROM AUTHOR]

Highlights: [•] and form by substitution of Bi3+ for Zn2+/Sn4+ in Zn2SnO4. [•] High dopant solubility relates to interattraction between and in lattice. [•] An n–p codopant band forms between CB and VB by high content and . [•] Visible light absorption is enhanced for SPS/PL by high Bi3+ solubility in Zn2SnO4. [ABSTRACT FROM AUTHOR]

By changing or fine-tuning the surface structure of the metal, the characteristics of surface plasmon – especially the interaction with light – can be customized. In this work, we numerically design a plasmonic nanostructure composed of a pair of symmetrical bifurcation nanostructures. An underlying optical property of the observed scattering and absorption cross section spectra and physical mechanism is illustrated by analyzing spatial distributions of the magnetic field, electric field, and surface current component at resonant wavelengths. Moreover, the extremely intense and highly confined electromagnetic fields induced in the bifurcation plasmonic nanostructure provide a sensitive environment to probe minor changes in the dielectric environment. Such high-performance composite nanostructure provides great potential for the application of sensing. • For this composite nanostructure, we focus on the optical properties of bifurcated nanostructure as shown in Fig. 2 (this paper). Especially in Fig. 2 (b) and (c), we can see the optical properties of single nanorod tetramer and fork dimer. It is clearly observed that the scattering spectrum of the bifurcation nanostructure is split into two resonance peaks by comparing with single nanorod tetramer or fork dimer, and a groove is formed in the middle with a sharp dip in scattering intensity and the corresponding absorption spectrum is significantly enhanced. The extremely intense and highly confined electromagnetic fields induced in the bifurcation plasmon nanostructure provides a sensitive environment to probe minor changes in the dielectric environment. • In this article, the structure we designed has both excellent sensing performance and field enhancement performance which can be used to design multi-function chips. • Our design is a simple flat structure, which is easy to process and manufacture in actual production. [ABSTRACT FROM AUTHOR]

• This paper is investigated a silicon-dielectric-metal nanostructure, it supports the optional anapole mode due to the destructive interference between electric and toroidal dipoles. • Such the proposed nanostructure exhibits a near-perfect ultra-narrow absorption spectrum in the near infrared region with the absorption bandwidth of 0.48 nm and a high-quality factor up to 1763. In addition, the structure we designed has both excellent sensing performance and field enhancement performance, which can be used to design multi-function chips. • Our design is a simple flat structure, which is easy to process and manufacture in actual production. This paper is investigated a silicon-dielectric-metal nanostructure, it supports the optional anapole mode due to the destructive interference between electric and toroidal dipoles. Such the proposed nanostructure exhibits a near-perfect ultra-narrow absorption spectrum in the near infrared region with the absorption bandwidth (FWHM) of 0.48 nm and a high-quality (Q) factor up to 1763. Besides inherently low dissipative losses and strong anapole response, this optical nanostructure can demonstrate subtle refractive index sensing properties. Our work shed new light on active ultra-narrow band perfect absorption based on the optical anapole mode, and provides potential applications such as optical sensors, narrow-band filter, non-radiative data transmission and biomolecules manipulation. [ABSTRACT FROM AUTHOR]

The application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) in glycan was limited due to their poor ionization efficiency, compared with biomolecules such as proteins and peptides. Aiming to improve the ionization efficiency and simplify preparation procedure simultaneously during MALDI MS analysis, an on-target derivatization method using 3-aminoquinoline (3-AQ)/α-cyano-4-hydroxycinnamic acid (CHCA) as matrix was employed and it was conducted both in the positive and negative ion MALDI TOF MS. Results indicated that after on-target derivatization, the ions generated had substantially improved S/N ratios and sensitivity in the tandem mass spectra. The B/Y− type ions of 3-AQ-labeled glycans could be easily recognized, and cross-ring A− type ions provided additional information to reveal the linkage patterns. Specifically, positive ion mass spectra with protonated adduct as precursor ion produced a simple fragmentation pattern benefited for sequencing and observation of branches. Furthermore, this method was successfully applied in polysaccharides analysis, including arabinoxylan, xylan, arabinogalactan and dextran after enzymatic or acid degradation. This study demonstrated that it was feasible to analyze higher molecular weight polysaccharides by MALDI TOF MS using 3-AQ/CHCA matrix through appropriate hydrolysis, and it allowed much efficient structural interpretation with increased sensitivity and characteristic fragment ions. [Display omitted] • On-target derivatization using 3-AQ/CHCA increased the ionization efficiency of polysaccharides. • The fragmentation of (A)XOS, malto-oligosaccharides and cyclodextrins in MALDI TOF MS were elucidated. • This method was applied to characterize the polysaccharides after degradation. [ABSTRACT FROM AUTHOR]

Resonant plasmonic nanostructures have attracted much attention due to their exotic optical properties. In this work, we numerically investigate single- and dual-gap ring structures, respectively, and they can be used for refractive index sensing by exciting the gap plasmon mode with sharp resonance spectra. The dual-gap ring plasmonic sensor shows the dual-channel properties and the corresponding sensitivities are 513 nm/RIU and 809 nm/RIU with the refractive indices range of 1.32–1.37, respectively. Furthermore, the gap ring structures are highly symmetrical, and have advantages in fabrication and pave the way for advanced optical devices to detect bio-molecules. [ABSTRACT FROM AUTHOR]

Carbohydrates are the most abundant organic compounds in nature, widely distributed in animals, plants and microorganisms. In order to understanding their structure properties, the following critical aspects should be revealed: a) building blocks (compositional monosaccharide); b) glycosidic linkages and anomeric configuration; c) sequence of sugar residues; d) molecular mass or degree of polymerization; e) substitutions. Mass spectrometry (MS) is a powerful technology for carbohydrate analysis. The development of ionization sources and mass analysers, as well as the possibility in coupling with different separation methods, extend their potential to carbohydrates research. Therefore, in this review, the research progress of carbohydrates investigated by MS technologies was summarized, mainly emphasized on how their structural features were elucidated, and a brief description of their applications in characterizing herbal and food polysaccharides, as well as proposing some suggestion of future development prospects. • The advance of mass spectrometry (MS) in structure characterization of carbohydrates was reviewed. • MS-based analytical strategies were introduced. • MS applications in analysis of herbal and food carbohydrates were also summarized. [ABSTRACT FROM AUTHOR]

• The graphene based metal–insulator-metal (MIM) metamaterial is investigated to realize an active and adjustable multi-band perfect absorber. • As the symmetry of T-shaped cavities is broken, the previous dual-band absorption will be converted to tri-band absorber. • The sensitivity is elaborately examined with different concentrations of CS 2 dropped into the cavities, and the refraction index per unit can reach up to a high value of 1673.33 nm/RIU. The graphene based metal-insulator-metal (MIM) metamaterial is numerically investigated to realize an active and adjustable multi-band perfect absorber, which is composed of an asymmetric double T-shaped cavity on the top layer. As the symmetry of T-shaped cavities is broken, the previous dual-band absorption will be converted to tri-band absorber. The corresponding electric field distribution at each resonant position is invesitgated to figure out the physical mechanism. More interestingly, these resonant peaks will split into multiband with further destruction of the central symmetry. In addition, non-contact dynamic control of perfect absorption is explored by tuning the Fermi energy, the polarization angle and the incident angle. Finally, the sensitivity of our proposed design is elaborately examined with different concentrations of CS 2 dropped into the cavities. The results demonstrate that the refraction index per unit can reach up to a high value of 1673.33 nm/RIU. Therefore, this work delivers a new strategy to design tunable multi-band absorbers and has potential applications in highly tunable optical switchers, sensors and filters. [ABSTRACT FROM AUTHOR]

The development of new and simple surface-enhanced substrates is primarily motivated by the ability to design and investigate the plasmonic structures to achieve the optimal performance in enhanced spectroscopy. In this work, we numerically design the plasmonic substrates by embedding a nanorod dimer antenna into a nanoring resonator. The single-layer composite substrate reveals a double-resonance response with a broad-spectrum electric field enchantment due to the plasmon hybridization of nanorod dimer and nanoring. The sandwiched substrate shows a complicated optical spectrum with multiple plasmon resonances, which can be attributed to the interaction of intralayer and interlayer plasmons. It is also worth mentioning that the electric field hot spots keep unmodified and concentrate at the middle gap of nanorod dimers in composite substrates at different excitation frequencies. The enhanced plasmonic substrate with consistent hot spots at different excitation frequencies can be used in surface-enhanced Raman spectroscopy and nonlinear optics. • The dual-band plasmon resonances with wide SERS activity can be realized in hybridized nanorod dimer plasmon substrate. • The multi-band plasmon enhanced substrates with unchanged hot spots can be realized in hybridized nanorod dimer. • The hot spots in designed plasmon-enhanced substrates remain unchanged at different excited wavelengths. [ABSTRACT FROM AUTHOR]

• Preparation of TiO 2 nanotube arrays by anodic oxidation. • The optimum parameters of the water content in electrolyte, anodizing time and ultrasonic post-treatment were determined. • The effects of each parameter on the morphology and crystal form of TiO 2 nanotube arrays was studied. • The effects of TiO 2 nanotube arrays with different anodization parameter on the photoelectric performance of DSSC were obtained. In this paper, TiO 2 nanotube arrays were prepared by anodic oxidation method. The effects of water content, anodizing time and sample post-treatment on the morphology and crystal structure of TiO 2 nanotube arrays were systematically investigated. We explored the performance of dye-sensitized solar cells (DSSCs) based on dye N-719. The TiO 2 nanotube arrays prepared under different water content and different anodizing time conditions were used as photoanodes. The results show that DSSC has best photovoltaic performance when the water content is 2 vol%. With the increase of oxidation time, J sc increases continuously, open voltage (V oc) and fill factor (FF) increase first and then decrease. The best optoelectronic properties obtained that the short circuit current, open circuit voltage, fill factor and photoelectric conversion efficiency as following, J sc = 5.2 mA/cm2, V oc = 0.7 V, FF = 0.54, η = 1.96% respectively. [ABSTRACT FROM AUTHOR]

• Cultured Cordyceps sinensis polysaccharides (CSP) improved intestinal morphology. • CSP restored intestinal related enzymes, growth factor and its receptor. • CSP upregulated tight junction proteins expression and downregulated MLCK, p-MLC. • CSP recovered tight junctions via MAPKs pathways. • CSP could attenuate cyclophosphamide-induced intestinal barrier injury in mice. Intestine is not only the largest digestive and absorbing organ, but also an important defensive barrier of the body. Maintaining healthy intestinal barrier is a prerequisite for intestinal function. In this study, polysaccharides from the cultured Cordyceps sinensis (CSP) were orally given to cyclophosphamide (Cy)-treated mice to investigate its protective effect on intestinal barrier injury. Results showed that CSP had positive effects on intestinal morphology, including restoring villus length and crypt depth as well as improving quantity of goblet cells and mucins expression. Furthermore, CSP enhanced intestinal alkaline phosphatase (IAP), diamine oxidase (DAO), epidermal growth factor (EGF) and its receptor (EGFR). In addition, occludin, claudin-1 and zonula occludins (ZO)-1 were upregulated and myosin light chain kinase (MLCK), p-MLC were downregulated by CSP. Moreover, CSP promoted p-ERK and inhibited p-JNK, p-p38. These findings suggested that CSP could attenuate Cy-induced intestinal barrier injury which maybe associated with mitogen-activated protein kinases (MAPKs) pathways. [ABSTRACT FROM AUTHOR]

We theoretical design of a triple-band perfect metamaterial absorber in the THz frequency range. We find the split ring resonator structure has three absorption peaks at frequencies 3.56 THz, 10.38 THz and 12.96 THz with absorption efficiency 99.57%, 99.98% and 99.76%, respectively. • By FDTD simulation calculation, we initially found that the presented split ring resonator has three perfect absorption peaks. • The absorption performance of the split ring resonator structure can be flexibly tuned by changing the chemical potential or relaxation time. • The proposed triple-band perfect metamaterial absorber has better sensing performance in high frequency bands. A triple-band perfect metamaterial absorber based on periodically arranged graphene split ring resonator (SRR) is proposed in this study. The calculation results by the FDTD method indicate that the SRR structure has three absorption peaks at frequencies 3.56 THz, 10.38 THz and 12.96 THz with absorption efficiency 99.57%, 99.98%, and 99.76%, respectively. By changing the chemical potential or relaxation time, the absorption characteristics of the split ring resonator structure can be flexibly tuned. Furthermore, we also examine the sensing performance of the proposed metamaterial absorber, the sensing performance of the high-frequency band is significantly higher than the low-frequency band. We believe that our results will pave the ways for the development of applications using metamaterials with high efficiency and multi-band spectral selectivity in biochemical sensing, optical switching, and modulating. [ABSTRACT FROM AUTHOR]

In this study, we combine the methods of magnetron sputtering, hydrothermal growth, and stepwise deposition to prepare novel ZnO@Ag3PO4 core-shell nanocomposite arrays structure. Through scanning electron microscope (SEM) topography test, energy dispersive spectrometer (EDS) element test and X-ray diffractometry (XRD) component test, we characterize the morphology, element distribution and structural characteristics of ZnO@Ag3PO4 core-shell nanocomposite arrays structure. At the same time, we test the samples for light reflectance, hydrophilicity and photoelectric performance. We find that after deposition of Ag3PO4 on ZnO nanorods, light reflectance decreases. As the time of depositions increases, light reflectance gradually decreases. After the deposition of Ag3PO4, the surface of the sample shows super hydrophilicity, which is beneficial for the photoelectric performance test. Through the optical transient response test, we find that the photo-generated current reaches a maximum when a small amount of Ag3PO4 is deposited. As the time of depositions of Ag3PO4 increases, the photogenerated current gradually decreases. Finally, we conducted an alternating current (AC) impedance test and also verified the correctness of the photocurrent test. Therefore, the structure is expected to be prepared into a photoanode for use in fields such as solar cells. [ABSTRACT FROM AUTHOR]

Estrogen–induced cholestasis is a common etiology of hepatic diseases in women with contraceptives administration, pregnancy or hormone replacement therapy. Farnesoid X receptor (FXR) is a member of nuclear receptor super family of ligand-activated transcription factors that is highly expressed in liver. FXR is acknowledged to contribute to the bile acid homeostasis, as well as the pathogenesis and progression of cholestasis. Specific targeting of FXR is an innovative approach for the treatment of cholestasis. The current study aimed to verify the anti-cholestasis effect of yangonin that is a natural product isolated from Kava via FXR signaling pathway in vivo and in vitro. The analyses of FXR gain- or loss-of-function were performed. Yangonin treatment ameliorates estrogen-induced cholestasis through increasing bile flow and biliary bile acid output. The mechanisms were an induction in the hepatic efflux transporters (Bsep and Mrp2) and an inhibition in hepatic uptake transporter (Ntcp) by yangonin. Likewise, yangonin through repressing Cyp7a1, Cyp8b1 and inducing Sult2a1 expression suppressed bile acid synthesis and promoted bile acid metabolism. Furthermore, yangonin improved estrogen–induced inflammatory cell infiltration and the inflammation gene expression. In vitro experiments further consolidated that yangonin alleviated estrogen–caused cholestasis via FXR activation. Noteworthily, the effects of yangonin were enhanced by FXR expression plasmids but abrogated by FXR siRNA. In conclusion, yangonin alleviates estrogen–induced cholestasis, due to FXR-mediated gene regulation. Image 1 [ABSTRACT FROM AUTHOR]

A polysaccharide from tamarind seeds (TSP) was characterized in terms of backbone and side chain structural features, as well as conformational property using methylation and GC–MS analysis, 2D NMR, MALDI-TOF MS, and high performance size exclusion chromatography (HPSEC). Results showed that TSP was a galactoxyloglucan (GXG) consisting of glucose, xylose, and galactose in a molar ratio of 3.1: 1.7: 1.0. The Mw was determined to be 524.0 kDa with radius of gyration (R g) of 55.6 nm. The chemical structure was confirmed as a classical β-(1 → 4)-glucan with short side chains of T-β-Gal p -(1 → 2)-α-Xyl p -(1 → and T-α-Xyl p -(1 → attached to O -6 position of glucose. MALDI-TOF MS analysis indicated that TSP mainly composed of nonasaccharide (XLLG) and octasaccharide (XLXG or XXLG) blocks in periodic or interrupted sequence in a ratio of 3: 2, occasionally interrupted by heptasaccharide (XXXG), hexasaccharide (XLG or XXGG), or even hendesaccharide blocks. Conformational study indicated that TSP was in a random-coil shape with relative extended stiff chain in aqueous solution. This study provided more evidences to make an amendment to the fine structure of tamarind GXG. Unlabelled Image • A classic cellulosic backbone of β-(1 → 4)-glucan was confirmed for TSP. • Short branches consisted of Xyl p and Gal p were distributed along the backbone. • TSP composed of XLLG and XLXG/XXLG units with slight XXXG, XLG/XXGG, and hendesaccharide blocks. • TSP showed as relative extended stiff random coil in aqueous solution. [ABSTRACT FROM AUTHOR]

Graphene and its derivatives are widely used in the field of energy conversion and management due to their excellent physical and chemical properties. In this paper, ultra-thin graphite film (GF) with thickness of 100–150 nm prepared by chemical vapor deposition was transferred to oxygen plasma-treated polyimide (PI) substrate as flexible heating film. The electrothermal and photothermal properties of GF on PI substrates with different treatment time were studied. The experimental results show that the PI substrate pretreated by oxygen plasma can change the surface morphology of GF, increase its electrical conductivity and light absorption capacity, and significantly improve the electrothermal and photothermal properties of GF heater. Under the low applied voltage of 5 V (power density of 0.81 W cm−2), the surface temperature of GF on 40 min plasma-treated PI substrate can rise to 250 °C, which is nearly 50 °C higher than that of GF on untreated PI substrate. When 100 nm thick commercial multilayer graphene film (MLG) is used, plasma-treated PI substrate can increase the electric heating temperature of MLG by 70 °C. In terms of photothermal performance, the surface temperature of GF on 50 min plasma-treated PI substrate can reach 73 °C under one Sun irradiation, which is 8 °C higher than that on untreated substrate. The experimental results are in good agreement with the simulation research. Our strategy has important implications for the development of efficient and energy-saving graphene/graphite-based heating films for advanced electrothermal and photothermal conversion devices. [ABSTRACT FROM AUTHOR]

We report on the synthesis of indium-silver bimetallic nanocomposites by chemical reduction method under atmospheric condition and their activity for surface-enhanced Raman scattering (SERS). It is found that the indium-silver bimetallic nanocomposites have better SERS activity with larger enhancement factors (EF) than pure silver nanoparticles with similar size. The SERS EF can reach 107 for 4-mercaptobenzoic acid and 109 for crystal violet and rhodamine 6G adsorbed on the nanocomposites and the detection limits can be at least down to 10−7 and 10−10 M, respectively. The results demonstrate that the indium-silver bimetallic nanocomposites are promising as SERS substrate for a myriad of chemical and biological sensing applications. [ABSTRACT FROM AUTHOR]

High conversion efficiency and quantum efficiency is essential for the phosphor in an efficient phosphor-based white light LEDs. Here, based on the coherent harmonic and the random independent emitter model, we demonstrate theoretically that the silicon nanoantenna array can dramatically enhance the output power of emitters in a phosphor layer by investigating the far-field radiation enhancement of an electric dipole assisted by silicon nanopillars in a waveguide structure. Compared with the plasmonic silver nanoantenna array, the silicon nanoantenna array can increase the enhancement factor of light extraction efficiency (LEE) over 50% for the dipole source at the wavelength of 620 nm, thus showing potential applications in white light LEDs. The enhanced LEE is ascribed to the low-loss directional light scattering of silicon nanoantennas and the strong guided mode resonances caused by their array. The calculation results also indicate that the far-field radiation can be tailored significantly by changing the aspect ratio of silicon nanopillars while presenting a good directivity. Our research is expected to give more insights into the design and optimization of the solid-state lighting, gaining and lasing systems by integrating silicon-based nanoantennas. [ABSTRACT FROM AUTHOR]

In this paper, a multi-physics field coupled model of electric, flow and particle fields was constructed by COMSOL to compare the effects of three different corrugated dust collector plates on electric field distribution, airflow field, particle trajectories and dust removal efficiency in an electrostatic precipitator, and to compare them with a conventional electrostatic precipitator with a parallel plate structure. The results indicated that the corrugated dust collection plate influenced the electric field within the ESP channel, while the wire plate spacing directly affected the size and distribution of space charge density. Furthermore, the corrugated dust collection plate also affected the EHD flow within the channel, with the D2-ESP and D3-ESP being the most strongly influenced by the ionic wind. By comparing the dust removal efficiency of the four ESPs, we found that D2-ESP has the highest dust removal efficiency, followed by D3-ESP, then Flat-ESP, and finally D1-ESP. The ranking order of the four ESPs' dust removal efficiency is consistent with the ranking order of the space charge density within the four ESP channels, which shows that the size of the space charge density directly affects the dust removal efficiency of ESPs. Numerical simulation results show that the change of wire plate spacing is the main reason why corrugated ESP affects the dust removal efficiency of electrostatic precipitators. [Display omitted] [ABSTRACT FROM AUTHOR]

The Chinese new intellectuals group came to the stage during the revolutionary of 1911 with some new features, such as with new knowledge structure, values and political ambitions who became truly modem intellectuals. Facing with an increasingly serious national crisis, they were an active part in the great revolutionary practice for the national salvation and "the regeneration of China. " From the spread of revolutionary ideas to the formation of revolutionary groups and development program of the Democratic Revolution, from the ideological struggles with the reformers to the many armed uprisings launched, the new intellectuals had played a pioneering role as a bridge to demonstrate a strong sense of crisis and social responsibility. [ABSTRACT FROM AUTHOR]

• CST and theoretical calculation show that the absorber is wavelength selective. • The grating structure based on graphene is easy to process and the processing system is mature. • The working band of the absorber is 0.5–10.5THz, covering the terahertz band completely, and the absorption peak distribution is relatively uniform, which indicates that the absorber has high application value. • By changing the graphene and Fermi energies, tuning the absorption properties can be achieved. • The absorber has high refractive index sensitivity and good sensing performance. Here we design a graphene-based polarization-insensitive, novel tunable broadband metamaterial absorber. The overall structure of the absorber is patterned graphene-dielectric layer - metal layer. We use localized surface plasmon resonance (LSPR), impedance matching and other theories to analyze its physical mechanism in detail. Then based on the finite element method (FEM), we used the simulation software CST STUDIO SUITE to simulate the absorbing characteristics of the designed absorber to obtain the spectral performance in the 0–10 THz band. In addition, the resonant frequency of the absorber can be changed by adjusting the Fermi level of graphene, when the Fermi level E f = 1.2 eV, the absorber has a broadband absorption effect, covering the 3.8∼7.19 THz band, and the absorption rate is above 90 %. Furthermore, the absorber exhibits independence from changes in polarization angle due to the overall symmetry. In fields such as stealth, filtering, spectral detection, terahertz imaging, etc., this technology has potential application prospects. [ABSTRACT FROM AUTHOR]

Mitophagy can selectively remove damaged mitochondria, which is critical in regulating mitochondrial homeostasis in diseases, such as cancer. Herein, we found that Aloe gel glucomannan (AGP) significantly inhibited the proliferation of colon cancer cells. RNA-seq analysis revealed that AGP upregulated autophagy, lysosome and mitochondrial fission signal pathways in colon cancer cell line CT26. Notably, AGP induced the accumulation of impaired and reactive oxygen species (ROS)-generating mitochondria, which triggered excessive mitophagy. Interestingly, the mitophagy activator enhanced AGP-induced mitophagy and cytotoxicity, whereas the mitophagy inhibitor reversed the influence of AGP. Furthermore, activation of PINK1/Parkin mitophagy pathway and transcription factor EB (TFEB) signaling was dependent on ROS overproduction. Taken together, these results indicated that AGP induced cytotoxic mitophagy through ROS-related PINK1/Parkin pathway and TFEB activation in CT26 cells. The research would provide theoretical basis for the development of AGP as a promising anticancer agent. [Display omitted] [ABSTRACT FROM AUTHOR]

Ag–Fe 3 O 4 nanocomposites were synthesized by the redox reaction between Ag 2 O and Fe(OH) 2 in the absence of additional reductant at moderate temperature and atmospheric condition. The as-synthesized Ag–Fe 3 O 4 nanocomposites are assembled into an orderly arrayed SERS substrate holding clean and reproducible properties with an applied external magnetic field. 4-mercaptobenzoic acid (4-MBA) is chosen as the probe molecule to test the enhancement factors (EF), uniformity and reproducibility of the SERS substrate. Experimental results indicate that the EF of 4-MBA on our proposed SERS substrate is up to 5.2 × 10 6 and the detection limit is down to ∼10 −10 M. The SERS spectra of 4-MBA molecules ranging from 200 cm −1 to 2000 cm −1 were randomly collected from a number of positions on the substrate and six Ag–Fe 3 O 4 nanocomposites substrates are measured with the same procedure. It is shown that the SERS substrate have the good uniformity and reproducibility with low standard deviation, indicating our proposed Ag–Fe 3 O 4 nanocomposites with external magnetic field control abilities have potential applications in the fields of magnetic separation and SERS techniques. [ABSTRACT FROM AUTHOR]

Background: Polygonatum cyrtonema, one of origins of Polygonata Rhizoma (HuangJing in Chinese), is traditionally steamed repeatedly before being used as herbal medicine in China. However, there has no standard for steaming of HuangJing. Therefore, a comprehensive study for effects of steam on polysaccharides from Polygonatum cyrtonema based on saccharide mapping, a powerful method developed for polysaccharides analysis, and pharmacological activity are still necessary, which is helpful to explore the effect of steam on the physiochemical and biological activities of its polysaccharides and develop steaming standard of Polygonatum cyrtonema. Methods: To explore the effect of steam on physiochemical and biological activities of P. cyrtonema polysaccharides (PCP), six polysaccharides named PCP0, PCP1, PCP2, PCP3, PCP4 and PCP5 were extracted from the herb consecutively steamed for 0–5 times, respectively. Their molecular weight distribution, monosaccharide composition and PACE fingerprints were investigated through HPSEC-MALLS-RID, HPAEC-PAD and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and HPTLC, respectively. In addition, their antioxidant ability and immunostimulatory activities on RAW 264.7 cells in terms of NO production and phagocytosis were compared. Results: Results suggested that molecular weights could be changed during steam, which increased by first steaming and then decreased with further steaming though all polysaccharides' molecular weights were 105-107 Da. They all showed irregularly spherical conformation in aqueous solution based on AFM imaging. Their monosaccharide composition and PACE fingerprints were significantly different after steaming, i.e., galactose increased while glucose and mannose decreased, and β-1,4-Galp appeared while β-1,4-Manp increased, after steaming. Steamed PCP significantly increased scavenging activity against ABTS radicals, while PCP0 had the best immunostimulatory effect on RAW 264.7 in terms of NO production and phagocytosis. Conclusions: In summary, steam significantly affected the chemical composition and bioactivities of polysaccharides from P. cyrtonema. Considering the balance beneficial effects of steaming on antioxidant and immunopotentiation activities of PCP, 2 times of continuous steam is the optimal choice under the given conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dendrobium officinale Polysaccharide (DOP) inhibits colon cancer cells growth. • DOP triggers autophagy, oxidative stress and AMPK signaling in colon cancer cells. • DOP-induced Mitochondrial damage causes autophagic cell death via ROS-AMPK pathway. The homeostasis between mitochondrial function and autophagy is crucial to the physiological activity of cancer cells, and its mechanism is conducive to the development of anti-tumor drugs. Here, we aimed to explore the effect and mechanism of Dendrobium officinale polysaccharide (DOP) on colon cancer cell line CT26. Our data showed that DOP significantly inhibited the proliferation of CT26 cells and elevated autophagy level. Moreover, DOP disrupted mitochondrial function through increasing reactive oxygen species (ROS) and reducing mitochondrial membrane potential (MMP), thereby impairing ATP biosynthesis, which activated AMPK/mTOR autophagy signaling. Intriguingly, the further experiments demonstrated that DOP-induced cytotoxicity, excessive autophagy and mitochondrial dysfunction were reversed after CT26 cells pretreated with antioxidant (N-acetyl- l -cysteine). Herein, these findings implied that DOP-induced mitochondrial dysfunction and cytotoxic autophagy repressed the propagation of CT26 cells via ROS-ATP-AMPK signaling, providing a new opinion for the study of antineoplastic drugs. [ABSTRACT FROM AUTHOR]

• Cordyceps sinensis polysaccharide (CSP) inhibited the growth of colon cancer cells. • CSP induced apoptosis and autophagy flux blockage in colon cancer cells. • Autophagy inhibition increased CSP-induced apoptosis in colon cancer cells. Cordyceps sinensis is thought to have anti-cancer effects, but its mechanisms remain elusive. In this study, we aimed to investigate the anti-cancer effect of Cordyceps sinensis polysaccharide (CSP) on human colon cancer cell line (HCT116) and its mechanism. Results indicated that CSP significantly inhibited the proliferation of HCT116 cells, increased autophagy and apoptosis, while blocked autophagy flux and lysosome formation. Further experiments showed that CSP decreased the expression of PI3K and phosphorylation level of AKT and mTOR, increased the expression of AMPKa and phosphorylation level of ULK1. In addition, repression of CSP-induced autophagy by bafilomycin (autophagy inhibitor) enhanced apoptosis and cell death of HCT116 cells. Hence, our findings suggested that CSP inhibited the proliferation of HCT116 cells by inducing apoptosis and autophagy flux blockage, which might be achieved through PI3K-AKT-mTOR and AMPK-mTOR-ULK1 signaling. CSP may be a potential therapeutic agent for colon cancer. [ABSTRACT FROM AUTHOR]

As a promising three-dimensional (3D) graphene architecture, graphene foam has excellent structural, electrical and thermal properties. However, due to the growth template limitation of commercial nickel/copper foam, graphene foam prepared by chemical vapor deposition (CVD) has a fixed 3D framework architecture, which limits its performance and application scenarios. In this paper, independent 3D graphite foam (GF) with different thickness and longitudinal compressibility was prepared by CVD method, and it was confirmed that mechanical compression of nickel foam template before graphite film deposition had a positive effect on the electrothermal, photothermal and mechanical properties of GF. At a low driving voltage of 3 V, the heating temperature of compressed GF with a low density of 8.9 mg/cm3 and a high porosity of 99.59 % can reach nearly 600 °C, which is nearly 250 °C higher than that of uncompressed GF. The excellent electrothermal performance of compressed GF is mainly attributed to the high crystallinity and thicker thickness (150–350 nm) of the graphite layers that make up the 3D framework, thus resulting in higher electrical conductivity. Under 1 and 2 sun illumination, the temperature of compressed GF can reach 83 °C and 109 °C respectively, which is 4–7 °C higher than that of the original GF. Compressed GF has better electrothermal, photothermal and radiant heating properties than traditional graphene/graphite foam and 2D graphene/graphite film. It not only has great application potential in high-efficient and energy-saving high-temperature electric heaters and photothermal converters, but also can be used as conductive supports or fillers with better performance, and has broad application prospects in flexible electronics, household appliances, artificial intelligence, medical care and other fields. [Display omitted] • Graphite foam with a denser 3D framework was prepared by compressed Ni foam template-assisted CVD method. • Compressed graphite foam has significantly improved electrothermal, photothermal and mechanical properties. • Compressed graphite foam can be heated to nearly 600 °C at a low driving voltage of 3 V. [ABSTRACT FROM AUTHOR]

Hepatic fibrosis is a reversible would-healing response following chronic liver injury of different aetiologies and represents a major worldwide health problem. Up to date, there is no satisfactory drugs treated for liver fibrosis. The present study was to investigate hepatoprotection of yangonin against liver fibrosis induced by thioacetamide (TAA) in mice and further to clarify the involvement of farnesoid X receptor (FXR) in vivo and in vitro. Yangonin treatment remarkably ameliorated TAA-induced liver injury by reducing relative liver weight, as well as serum ALT and AST activities. Moreover, yangonin alleviated TAA-induced accumulation of bile acids through increasing the expression of bile acid efflux transporters such as Bsep and Mrp2, and reducing hepatic uptake transporter Ntcp expression, all of these are FXR-target genes. The liver sections stained by H&E indicated that the histopathological change induced by TAA was improved by yangonin. Masson and Sirius red staining indicated the obvious anti-fibrotic effect of yangonin. The mechanism of anti-fibrotic effect of yangonin was that yangonin reduced collagen content by regulating the genes involved in hepatic fibrosis including COL1-α1 and TIMP-1. Besides, yangonin inhibited hepatic stellate cell activation by reducing TGF-β1 and α-SMA expression. In addition, yangonin protected against TAA-induced hepatic inflammation via its inhibition of NF-κB and TNF-α. These hepatoprotective effects of yangonin were abrogated by guggulsterone which is a FXR antagonist. In vitro experiment further demonstrated dose-dependent activation of FXR by yangonin using dual-luciferase reporter assay. In summary, yangonin produces hepatoprotection against TAA-induced liver fibrosis via FXR activation. Unlabelled Image • Yangonin protects against TAA-induced hepatic fibrosis via FXR activation. • Yangonin reduces collagen content by regulating COL1-α1 and TIMP-1 expression. • Yangonin inhibits hepatic stellate cell activation by reducing TGF-β1 and α-SMA expression. • Yangonin suppresses liver inflammation through repressing inflammation-related genes. • Yangonin modulates bile acid homeostasis. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study of light trapping and localization in graphene grating-sheet structure by numerical simulation, and shows a strategy to realize controllable absorption enhancement and localized field enhancement in a large-area continuous graphene monolayer. For the structure with strong plasmons coupling, more than 95% of total absorption and 60% of optical absorption in graphene sheet are realized at two different infrared wavelengths over a wide incident angle range. Meanwhile, the enhanced E-field around the graphene sheet is over 40 times of magnitude stronger than that of the incident field. Additionally, by changing the Fermi energy of graphene or the distance between the sheet and the grating, adjustable light trapping and switchable infrared absorber/reflector can be obtained. These features enable the coupled graphene grating-sheet to serve as platform for infrared sensing, photodetection and light-matter interactions. [ABSTRACT FROM AUTHOR]

Detailed characterization in nutrients and phytochemicals with antioxidant activities of 26 kidney beans was performed. The kidney beans contained high levels of dietary fiber (29.32–46.77%), resistant starch (9.16–18.09%) and protein (22.06–32.63%) but low levels of lipid (1.05–2.83%) and sugars (1.55–9.07%). The monosaccharide composition of soluble fiber was dominated by arabinose, galactose, mannose and galacturonic acid. The ratio of essential amino acid to the total amino acid was ranged from 0.29 to 0.36. The predominant fatty acid was polyunsaturated fatty acids, accounting for 47.54–67.26% of total fatty acids. The total tocopherol content was in the range of 12.83–68.35 μg/g, predominantly γ-tocopherol, followed by δ-tocopherol. In addition, certain levels of total phenolics and flavonoids with respective values of 0.25–3.79 mg gallic acid equivalent/g dry weight and 0.19–7.05 mg rutin equivalent/g dry weight resulted in significant antioxidant activities. And a good correlation was observed between TPC and FRAP values (R2 = 0.8030). The results indicated that kidney beans are excellent sources of health-promoting compounds. [ABSTRACT FROM AUTHOR]

Aims: To assess the effect of saxagliptin monotherapy on blood glucose and islet β-cell function in obese patients with newly diagnosed pre-diabetes and abnormal fat metabolism.Methods: A 24-week, randomized controlled trial was conducted involving 25 obese subjects with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) (mean age 45years) to receive lifestyle intervention only (control group) or combined with saxagliptin 2.5mg or 5mg daily (S2.5 or S5 group), metformin 1500mg daily (Met group). Anthropometrics, body fat and biochemical parameters were measured before and after 4, 12 and 24weeks intervention.Results: S5 group and Met group showed a significant decrease in fasting plasma glucose (FPG) and HbA1c compared with the control group (all P<0.05) after 24-week intervention. However, the decrease in 2h postprandial plasma glucose levels (2hPPG) in S5 group were greater compared with control group (P<0.01). Insulin resistance (HOMA-IR) was reduced in S5 group, Met group and control group (P<0.05), and the β-cell function (HOMA-β) was improved in all groups (P<0.05). However, the changes in obesity-related indicators including waist circumference, hip circumference, weight, BMI, body fat, percentage of body fat and waist-to-hip fat ratio were greate in Met group (all P<0.05) compared with other groups (P>0.05).Conclusions: Saxagliptin monotherapy may prevent or delay the progression of IGT or IFG to type 2 diabetes mellitus in obese patients with newly diagnosed pre-diabetes. ClinicalTrials.gov: NCT01960205. [ABSTRACT FROM AUTHOR]

Multilayer graphene (MLG) with a thickness of about 100 nm has proved to be a promising smart thermal surface material with excellent tunability of emissivity, but the performance of MLG will deteriorate significantly with the further increase of film thickness. In this study, mid-infrared radiation modulators based on 500 nm-thick graphite thin films (NGF) were prepared and their infrared radiation performance through ionic liquid intercalation was studied. The experimental results show that modulation depth of NGF with a large number of crumples on the surface prepared under different hydrogen flow rates can reach 0.32–0.37, which is comparable to that of commercial MLG with a thickness of 100 nm. The numerical simulation results show that crumpled surface morphology of NGF is very beneficial to the improvement of the electrically controlled thermal radiation performance, and the crumpled graphene/graphite film has a greater emissivity modulation depth than the flat film. The results can provide inspiration for improving the thermal radiation modulation capability of graphene/graphite thin films through morphology control, thus promoting the application of graphene/graphite in thermal camouflage, radiative cooling, personal thermal management and infrared communication. [Display omitted] • Electrically controlled thermal radiation modulator based on 500 nm-thick graphite thin film is prepared. • The crumpled graphite thin film has a greater emissivity modulation depth than the flat film. • Surface crumples can improve the emissivity modulation performance of graphite thin film. [ABSTRACT FROM AUTHOR]

Due to the helical phase profile as well as the topological charge-independent doughnut spatial structure, perfect vortex beams have attract attentions in fiber communications and particle manipulations. However, for some advanced applications such as optical cage and optical microfluidic sorting and acceleration, it is more meaningful to generate asymmetric optical vortex fields such as elliptic perfect optical vortex (EPOV) beams. Herein we utilize silicon nitride nanopillars, functioning as half-wave plates, to construct high-efficiency geometric phase metasurfaces for the generation of EPOV beams with the integer and fractional topological charges in the ultraviolet range. By adjusting scaling factor, the shape of beams can be freely changed from circle to ellipse. In addition, multi-channel EPOV beams with arbitrary shape and different topological charges are produced with the help of the superposition principle of phase in Fourier space. We envision that this ultraviolet metasurface-based generator of EPOV beams can be used for manipulation of microscopic particle along an ellipse with acceleration and for the generation OAM-entangled photons. • Efficient dielectric metasurfaces for the generation of elliptic perfect optical vortex (EPOV) beams. • Shape of EPOV beams can be freely changed from circle to ellipse by changing scaling factor. • Multi-channel EPOV beams with arbitrary shape and different topological charges are produced. [ABSTRACT FROM AUTHOR]

Tunable thermal radiation metasurfaces have important application prospects in thermal management, energy utilization, thermal information processing and other fields. In this paper, the thermal radiation metasurface is combined with information coding and infrared imaging technology. Based on graphene-metal hybrid structure, 1-bit and 2-bit tunable radiation coding metasurface containing two and four types of pixel structures respectively are designed for infrared anticounterfeiting and information encryption. The emissivity of these pixel structures is adjustable and satisfies specific relationships according to different design schemes and channel requirements. The spatial distribution of infrared emission is controlled by the spatial arrangement of different pixel structures to carry patterns, characters or digital information. With globally controlling graphene and/or infrared wavelength selection, infrared images can be displayed and switched, and hidden information can only be extracted in specific channels. Compared with the static metasurface and 1-bit coding metasurface, 2-bit coding metasurface has higher security and flexibility. The graphene-based tunable radiative metasurface and its pixel coding and infrared image display scheme proposed in this paper provide a new idea for expanding optical information encryption methods, which has great application potential in dynamic information encryption, high-end anticounterfeiting, optical data storage and information authentication. [Display omitted] • Graphene-metal hybrid radiative metasurfaces are designed for information encryption and anticounterfeiting. • Display and switch infrared images by globally controlling graphene and/or infrared wavelength selection. • The proposed 2-bit coding metasurface can encrypt information with higher security and flexibility. [ABSTRACT FROM AUTHOR]

A novel Zr 1- x Fe x V 2- x Mo x O 7 (0 ≤ x ≤ 0.9) material is developed and the effect substitutions of Fe 3+ /Mo 6+ for Zr 4+ /V 5+ in ZrV 2 O 7 on the thermal expansion property are investigated. For the smaller x value ( x ≤ 0.5), their crystal structures remain cubic. The one of x = 0.5 is much higher than recent reports about uni-substitution of P 5+ for V 5+ and dual-substitution of Cu 2+ /P 5+ for Zr 4+ /V 5+ . For a substitution more than 0.5, crystal lattice appears distorted and 3 × 3 × 3 superstructure disappears gradually. For the substitution of x = 0.9, low thermal expansion is obtained from 140 to 700 K, which holds great potential applications in low temperature field. The mechanism of low thermal expansion of Zr 1- x Fe x V 2- x Mo x O 7 (0 ≤ x ≤ 0.9) is discussed around the distortion of crystal structure due to the substitutions of Fe 3+ /Mo 6+ for Zr 4+ /V 5+ in ZrV 2 O 7 . [ABSTRACT FROM AUTHOR]

Although great progress has been made in stealth research based on metamaterial/metasurface, it is still a great challenge to achieve broadband, wide-angle and full polarization stealth at the same time. In this paper, a metasurface carpet cloak based on graphene rings is proposed to address this issue. Simulation results demonstrate that the arched carpet cloak can achieve a polarization-insensitive invisibility with a large working bandwidth of 45% and a wide angular span of ±40° in terahertz range. The cloaking bandwidth can be further increased to 60% by adjusting graphene Fermi energy to control the phase dispersion of meta-atoms. By comparing the arched and triangular carpet cloaks and the arched carpet cloaks with different curvature, the sensitivity of cloaking performance to the shape of carpet cloak is demonstrated. The metasurface based on graphene ring can not only give a good solution for broadband, wide-angle and polarization-insensitive invisibility in terahertz to mid-infrared region, but also provide inspiration for the construction of other metasurface devices with excellent performance. • A graphene metasurface is proposed for achieving broadband, wide-angle and polarization-insensitive carpet cloak. • A cloaking bandwidth of 45% and an angular span of ±40° are realized for both linearly and circularly polarized waves. • The bandwidth can be further expanded to 60% by unified regulating the Fermi energy of graphene metasurface. • The sensitivity of cloaking performance of carpet cloak to its shape is demonstrated. [ABSTRACT FROM AUTHOR]

Poly(lactic-co-glycolic acid) (PLGA) based minimized particles have been widely applied in drug delivery system, but pristine PLGA particles suffers from low efficiency in release and non-targeted effect for drug delivery system. Inspired by cancer cells environment, we have fabricated an effective ATP-triggered delivery system based on porous ZIF-90@PLGA microparticles and demonstrated Förster resonance energy transfer between riboflavin sodium phosphate and doxorubicin occurring in ZIF-90. This drug delivery system exhibits controlled ATP responsiveness, low toxicity and hemolysis, and improved fluorescence intensity of doxorubicin, which has great potential application for ATP-responsive controlled drug release, as well as the real-time fluorescent imaging of tumor issues. [Display omitted] Poly(lactic-co-glycolic acid) (PLGA) based microparticles have been widely applied in drug delivery system, but pristine PLGA particles suffers from low efficiency in release and non-targeted effect for drug delivery system. Inspired by cancer cells environment, we have fabricated an ATP-triggered delivery system based on porous PLGA microspheres covering drug-loaded ZIF-90. The system contains controlled doxorubicin releasing because ZIF-90 nanocrystals are easily collapsed under exposing to high-concentration ATP environment. In addition, ZIF-90@PLGA microparticles also perform low toxicity and 2.37 % hemolysis, and improved fluorescence intensity of doxorubicin by loading riboflavin sodium phosphate benefited from their partial Förster resonance energy transfer. This novel ATP-triggered drug delivery system based on porous PLGA particles could be widely utilized to design effective drug release biomaterials for gastric and lung cancer. [ABSTRACT FROM AUTHOR]

We propose and demonstrate a novel perfect absorber platform by combining the colloidal crystal and refractory metal layer. Dual-band absorption with the efficiency up to 99.8% (0. 336 μ m) and 99.1% (1. 382 μ m) is achieved. Moreover, the absorption bandwidths are 81 nm and 1237 nm for the two bands in the UV and near-infrared ranges, suggesting the simultaneous achievement of narrowband and ultra-broadband absorption. Furthermore, the resonant wavelengths in the two bands are with the geometric multiples up to 3 ∼ 6, indicating the large differential frequency responses. In addition, the absorption properties can be artificially adjusted via the structural parameters. These features can hold potential applications in the nonlinear optics such as frequency multiplication, difference and mixing, and the selective spectral filtering and manipulation, etc. • A novel absorber is achieved by combining colloidal crystal and refractory metal. • Dual-band absorption with A of 99.8% and 99.1% is achieved. • Narrowband and ultra-broadband absorption is simultaneous achieved. • It can hold applications in nonlinear optics, selective filtering, etc. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the protective effect of cultured Cordyceps sinensis polysaccharides (CSP) on cyclophosphamide (Cy)-induced intestinal mucosal immunosuppression and microbial dysbiosis in mice. Results showed that CSP stimulated cytokines secretion (IL-12, IFN-γ, IL-4, IL-13, IL-6, IL-17, IL-10, TGF-β3, TNF-α, IL-2, IL-21) and transcription factors production (T-bet, GATA-3, RORγt, Foxp3). TLRs (TLR-2, TLR-4, TLR-6) and NF-κB pathway key proteins (p-IκB-α, NF-κB p65) were also upregulated after CSP administration. Moreover, CSP recovered SCFAs levels which decreased by Cy treatment. Furthermore, 16S rRNA sequencing of fecal samples was performed. α-diversity and β-diversity analysis revealed CSP improved microbial community diversity and modulated the overall structure of gut microbiota. Taxonomic composition analysis found that CSP increased the abundance of probiotics (Lactobacillus, Bifidobacterium, Bacteroides) and decreased pathogenic bacteria (Clostridium, Flexispira). These findings suggested the potential of CSP as a prebiotics to reduce side effects of Cy on intestinal mucosal immunity and gut microbiota. [ABSTRACT FROM AUTHOR]

In this paper, we present a dual-band metamaterial absorber for graphene surface plasmon resonance at terahertz frequency. We use the finite difference time domain (FDTD) method to study the absorption characteristics of the homocentric graphene ring and disk nanostructure. These simulation results show that the change of the geometrical parameters and the substrate thickness of the nanostructure can change the absorption characteristics and the emergence of dual-band absorption peaks. Moreover, we study the field distribution of nanodisks with different radius in detail. By changing the Fermi level of graphene, the wavelength of their absorption peaks can be adjusted flexibly. In addition, the proposed dual-band absorber also shows a good angle tolerance for both TE and TM polarizations. By calculation the surface-filled water (n = 1.332) and 25% aqueous glucose solution (n = 1.372) for the metamaterial absorber, the sensitivities of mode I and mode II are 5.0 μm/RIU and 15.0 μm/RIU. These research results will have broad application prospects for sensing and spatial light modulators. We present a dual-band metamaterial absorber for graphene surface plasmon resonance at terahertz frequency. We find the nanostructure absorption peak wavelength is flexible and adjustable by changing the graphene Fermi level E F. Image 1 • The absorption enhancement of the nanostructure can be achieved by changing the geometric parameters. • By changing the Fermi level, the absorption characteristics can be tuned. • As the relaxation time increases, the absorption maximum also increases, while the resonance peak wavelength remains unchanged. • For TM and TE polarizations, the absorbers are insensitive to the incident angle. [ABSTRACT FROM AUTHOR]