Anti-inflammatory effect and antihepatoma mechanism of carrimycin.

BACKGROUND: New drugs are urgently needed for the treatment of liver cancer, a feat that could be feasibly accomplished by finding new therapeutic purposes for marketed drugs to save time and costs. As a new class of national anti-infective drugs, carrimycin (CAM) has strong activity against gram-positive bacteria and no cross resistance with similar drugs. Studies have shown that the components of CAM have anticancer effects. AIM: To obtain a deeper understanding of CAM, its distribution, metabolism and anti-inflammatory effects were assessed in the organs of mice, and its mechanism of action against liver cancer was predicted by a network pharmacology method. METHODS: In this paper, the content of isovaleryl spiramycin III was used as an index to assess the distribution and metabolism of CAM and its effect on inflammatory factors in various mouse tissues and organs. Reverse molecular docking technology was utilized to determine the target of CAM, identify each target protein based on disease type, and establish a target protein-disease type network to ascertain the effect of CAM in liver cancer. Then, the key action targets of CAM in liver cancer were screened by a network pharmacology method, and the core targets were verified by molecular docking and visual analyses. RESULTS: The maximum CAM concentration was reached in the liver, kidney, lung and spleen 2.5 h after intragastric administration. In the intestine, the maximum drug concentration was reached 0.5 h after administration. In addition, CAM significantly reduced the interleukin-4 (IL-4) levels in the lung and kidney and especially the liver and spleen; moreover, CAM significantly reduced the IL-1ß levels in the spleen, liver, and kidney and particularly the small intestine and lung. CAM is predicted to regulate related pathways by acting on many targets, such as albumin, estrogen receptor 1, epidermal growth factor receptor and caspase 3, to treat cancer, inflammation and other diseases. CONCLUSION: We determined that CAM inhibited inflammation. We also predicted the complex multitargeted effects of CAM that involve multiple pathways and the diversity of these effects in the treatment of liver cancer, which provides a basis and direction for further clinical research.

In vivo evaluation and mechanism prediction of anti-diabetic foot ulcer based on component analysis of Ruyi Jinhuang powder.

BACKGROUND: Diabetes is a metabolic disease with a high complication rate. Diabetic foot ulcers (DFUs) seriously affect the quality of life of patients. A total of 15%-20% of diabetic patients develop DFUs, which heal with difficulty over a long time and can result in amputation and disability. Traditional Chinese medicine has a unique effect in the treatment of skin ulcerative diseases. Ruyi Jinhuang powder (RHP) is one of the classic prescriptions in traditional Chinese medicine and is widely used in clinical practice. AIM: To verify the ability of RHP to promote wound healing by electron microscopy analysis in animal models and hematoxylin-eosin (HE) staining. The effective components of RHP were extracted and identified by gas chromatography-mass spectrometry (GC-MS), and the obtained chemical components were analyzed by network pharmacology methods to predict its therapeutic mechanism. METHODS: Sprague Dawley rats were injected with streptozotocin to establish the DFU model. HE staining was used to observe the wound tissue under an electron microscope. The chemical constituents of RHP were extracted first by supercritical fluid extraction and alcohol extraction, and then, GC-MS and ultra-performance liquid chromatography-MS were used to separately identify the chemical constituents. In addition, the "herb-component-target" link was established through the Traditional Chinese Medicine Systems Pharmacology database to obtain the target information, and the molecular docking of important components and key targets was performed in Discovery Studio software. Cytoscape software was used to visualize and analyze the relationship between the chemical composition, targets and Traditional Chinese Medicine network. RESULTS: RHP promoted DFU healing in rats by affecting fibroblasts and nerve cells. A total of 89 chemical components were obtained by GC-MS. Network pharmacological analysis revealed that RHP was associated with 36 targets and 27 pathways in the treatment of DFU, of which the important components were luteolin, trans caryophyllene, ar-turmerone, palmitic acid, methyl palmitate, gallic acid, demethoxycurcumin, berberine, and rheic acid. The key targets were posttranscriptional silencing, topoisomerase II alpha, muscarinic acetylcholine receptor M2, interleukin 6, tumor necrosis factor and retinoic X receptor alpha, and the key pathways were the phosphoinositide 3-kinase-protein kinase B signaling pathway, neuroactive ligand-receptor interactions, and the forkhead box O signaling pathway. CONCLUSION: Our results indicated that RHP may play a role in the treatment of DFU through these target pathways by affecting insulin resistance, altering the nervous system and immune system, participating in inflammatory responses and regulating cell proliferation, differentiation and apoptosis through other specific mechanisms.

Insights into the highly efficient treatment of dyeing wastewater using algal bloom derived activated carbon with wide-range adaptability to solution pH and temperature.

Here, a low-cost acid-base and temperature tolerant algal bloom derived activated carbon (ABAC) was successfully prepared to remove rhodamine B (RhB) from water. The ABAC exhibited maximum adsorption capacity of RhB (1101 ± 11 mg/g), higher than that of laboratory-prepared rape straw activated carbon (176 ± 5 mg/g) and commercial activated carbon (489 ± 5 mg/g). It is attributed to larger surface area and mesoporous structure of the ABAC. Furthermore, the effective adsorption of RhB by using ABAC was achieved at a wide range of solution pH (3.2-10.8) and temperature(25-50 °C). The mass transfer resistance of RhB adsorption process well depicted by Langmuir model was controlled by external mass transfer. The adsorption process involved both secondly chemisorption (H-bonds and π-π interaction) and dominated physisorption. Four dyes in river water were efficiently removed. This work provides a promising approach for developing high-absorption biomass materials for actual dye wastewater treatment.

Metal-organic framework IRMOFs coated with a temperature-sensitive gel delivering norcantharidin to treat liver cancer.

BACKGROUND: Norcantharidin (NCTD) is suitable for the treatment of primary liver cancer, especially early and middle primary liver cancer. This compound can reduce tumors and improve immune function. However, the side effects of NCTD have limited its application. There is a marked need to reduce the side effects and increase the efficacy of NCTD. AIM: To develop a nanomaterial carrier, NCTD-loaded metal-organic framework IRMOF-3 coated with a temperature-sensitive gel (NCTD-IRMOF-3-Gel), aiming to improve the anticancer activity of NCTD and reduce the drug dose. METHODS: NCTD-IRMOF-3-Gel was obtained by a coordination reaction. The apparent characteristics and in vitro release of NCTD-IRMOF-3-Gel were investigated. Cell cytotoxicity assays, flow cytometry, and apoptosis experiments in mouse hepatoma (Hepa1-6) cells were used to determine the anti-liver cancer activity of NCTD-IRMOF-3-Gel in in vitro models. RESULTS: The particle size of NCTD-IRMOF-3-Gel was 50-100 nm, and the particle size distribution was uniform. The release curve showed that NCTD-IRMOF-3-Gel had an obvious sustained-release effect. The cytotoxicity assays showed that the free drug NCTD and NCTD-IRMOF-3-Gel treatments markedly inhibited Hepa1-6 cell proliferation, and the inhibition rate increased with increasing drug concentration. By flow cytometry, NCTD-IRMOF-3-Gel was observed to block the Hepa1-6 cell cycle in the S and G2/M phases, and the thermosensitive gel nanoparticles may inhibit cell proliferation by inducing cell cycle arrest. Apoptosis experiments showed that NCTD-IRMOF-3-Gel induced the apoptosis of Hepa1-6 cells. CONCLUSION: Our results indicated that the NCTD-IRMOF-3-Gel may be beneficial for liver cancer disease treatment.

Particle electrode materials dependent tetrabromobisphenol A degradation in three-dimensional biofilm electrode reactors.

The completely biological degradation of Tetrabromobisphenol A (TBBPA) contaminant is challenging. Bio-electrochemical systems are efficient to promote electrons transfer between microbes and pollutants to improve the degradation of refractory contaminants. In particular, three-dimensional biofilm electrode reactors (3DBERs), integrating the biofilm with particle electrodes, represent a novel bio-electrochemical technology with superior treatment performances. In this study, the electroactive biofilm is cultured and acclimated on two types of particle electrodes, granular activated carbon (GAC) and granular zeolite (GZ), to degrade the target pollutant TBBPA in 3DBERs. Compared to GZ, GAC materials are more favorable for biofilm formation in terms of high specific surface area and good conductivity. The genus of Thauera is efficiently enriched on both GAC and GZ particles, whose growth is promoted by the electricity. By applying 5 V voltage, TBBPA can be removed by over 95% in 120 min whether packing GAC or GZ particle electrodes in 3DBERs. The synergy of electricity and biofilm in TBBPA degradation was more significant in GAC packed 3DBER, because the improved microbial activity by electrical stimulation accelerates debromination rate and hence the decomposition of TBBPA. Applying electricity also promotes TBBPA degradation in GZ packed 3DBER mainly due to the enhanced electrochemical effects. Roles of particle electrode materials in TBBPA removal are distinguished in this work, bringing new insights into refractory wastewater treatment by 3DBERs.

A pilot-scale three-dimensional electrochemical reactor combined with anaerobic-anoxic-oxic system for advanced treatment of coking wastewater.

Coking wastewater is highly concentrated and extremely toxic, greatly challenging the treatment technologies. Conventional biological technology such as anaerobic-anoxic-oxic (A2O) system is inefficient, since various biological reactions are inhibited by toxicants in coking wastewater. In this work, a pilot-scale three-dimensional electrochemical reactor (3DER) is integrated into the A2O system as a pretreatment unit to improve the treatment efficiency of coking wastewater. The results indicate that 3DER pretreatment increased the biodegradability of coking wastewater, promoting the degradation of coking wastewater in A2O system. The integrated 3DER-A2O system can remove 94.4% of COD and 76.2% of TN from coking wastewater, and the energy consumption was only 0.22 kWh/kg COD and 4.69 kWh/kg TN. The components of coking wastewater were significantly simplified and the acute toxicity was reduced from 99% to 12% after the treatment. The integrated 3DER-A2O system provides a new solution for coking wastewater treatment, showing a promising application potential.

A Novel Bristle-Shaped Semi-Dry Electrode With Low Contact Impedance and Ease of Use Features for EEG Signal Measurements.

OBJECTIVE: In this paper, we present a novel soft bristle-shaped semi-dry electrode for electroencephalography (EEG) recording. Because the bristle-shaped structure with electric conductivity could overcome the obstacle of hair and enable direct connection to scalp, the semi-dry electrode could work with drinking water instead of saline water that was widely used in previous semi-dry or water electrodes to improve its convenience. The electrode consisted of conductive bristles and a 3D-printed casing. Carbon-coated nylon conductive bristles could achieve low impedance and soft properties of the semi-dry electrode. The bristles could spread on skin and realize a larger contact area. The carbon-coated conductive bristles could also continuously penetrate water into the corneum of skin to reduce contact impedance. The contact impedance of the bristle-shaped semi-dry electrode was similar to the traditional wet electrode, but much lower than dry electrode. Although the saline water had much lower impedance than drinking water, our electrode still achieved even lower skin-electrode contact impedance than previous semi-dry or water electrode with saline water. The alpha rhythms, P300 visual evoked potential, and steady-state visual evoked potential were, respectively, measured to evaluate the electrode performance for EEG recording.

[Mechanism of the anthocyanin single component cyanidin-3-O-glucoside inhibiting proliferation and migration of B16-F10 cells].

To study the effects of the anthocyanin single component cyanidin-3-O-glucoside (Cy-3-glu) on the proliferation and migration of mouse melanoma cells and to elucidate the underlying mechanisms, B16-F10 cells were treated with different concentrations of Cy-3-glu. Cell viability was analyzed by a CCK-8 method. Cell migration was determined by the callus scratching technique. Cell cycle was measured by the flow cytometry. The expression levels of genes involved in cell cycle regulation were detected by real-time PCR. Protein expression levels of p-AKT, E-cadherin, N-cadherin and vimentin were analyzed by Western blot. The growth and migration of B16-F10 cells in C57BL/6J mice were monitored by the cryogenically cooled IVIS-imaging system. The results showed that Cy-3-glu significantly inhibited the growth (P < 0.001) and migration (P < 0.01) of B16-F10 cells, and arrested the cell cycle in the S phase. After Cy-3-glu treatment, the expression levels of p-AKT (P < 0.05), N-cadherin and vimentin (P < 0.001) were decreased significantly, and the expression level of E-cadherin was dramatically increased (P < 0.05). The size and weight of tumors and tumor metastasis in mice fed with a diet containing Cy-3-glu were significantly reduced (P < 0.05). In conclusion, Cy-3-glu inhibits proliferation and migration of B16-F10 cells by inhibiting the PI3K/AKT signaling pathway, cell adhesion and migration signals.

pH dependence of the binding interactions between humic acids and bisphenol A - A thermodynamic perspective.

The wide application of bisphenol A (BPA) leads to the emergence of BPA residuals in natural water environments. Dissolved organic matter (DOM) existed in water can bind with BPA, hence influencing the migration and transformation of BPA in aquatic environments. pH is a crucial factor governing the binding interactions between DOM and BPA. However, the mechanisms driven the binding process under different pH conditions are still unclear. In this study, the interactions between BPA and humic acids (HA), a primary component of DOM, are investigated over a wide pH range of 3-12 by integrating fluorescence quenching, dynamic light scattering and microcalorimetry. pH dependence of the binding interactions between HA and BPA are interpreted from a thermodynamic perspective. The results indicate that HA can spontaneously interact with BPA to form a stable HA-BPA complex. With the increasing pH, the binding interactions change from entropy driven to entropy-enthalpy co-driven. Hydrophobic force dominate the binding interactions under acidic condition. The synergy of hydrophobic force and hydrogen bond promotes the binding process under neutral condition. Under alkaline conditions, electrostatic repulsion participates the binding process in addition to hydrophobic force and hydrogen bond, weakening the binding strength. Therefore, neutral pH is favorable for HA to bind with BPA, consequently enhancing the dissolution of BPA in natural water bodies. The results are beneficial to better understand the pH dependent distribution of BPA in aquatic environments.

Co-doping polymethyl methacrylate and copper tailings to improve the performances of sludge-derived particle electrode.

Three-dimensional electrochemical reactor (3DER) is a highly efficient technology for refractory wastewater treatment. Particle electrodes filled between anode and cathode are the core units of 3DER, determining the treatment efficiency of wastewater. However, particle electrodes deactivation due to catalytic sites coverage seriously impedes the continuous operation of 3DER. In this work, granular sludge carbon (GSC) particle electrodes being resistant to deactivation are fabricated by pyrolyzing the mixture of waste sludge, polymethyl methacrylate (PMMA), and copper tailings, whose performances are evaluated by degrading rhodamine B (RhB) wastewater in a continuous-flow 3DER. Results indicate that hierarchical-pore structure comprising macro-, meso-, and micropores is developed in GSC-10-CTs by doping 10 g PMMA and 5 g copper tailings into 100 g waste sludge. PMMA contributes to construct macropores, which is essential for the mass transfer of RhB into GSC particle electrodes of centimeter-size. Copper tailings promote the formation of meso- and micro-pores in GSCs, as well as improving the electrochemical properties. Consequently, GSC-10-CTs packed 3DER exhibits the highest removal efficiency and lowest energy consumption for RhB treatment. In addition, the compressive strength of GSC-10-CTs is enhanced by copper tails, that is crucial to fill into 3DER as particle electrodes. The high-efficient and cost-effective GSC-10-CTs fabricated by waste materials have the potential of substituting commercial granular activated carbon catalysts in the future, consequently promoting the application of 3DER in wastewater treatment.

Insights into thermodynamic mechanisms driving bisphenol A (BPA) binding to extracellular polymeric substances (EPS) of activated sludge.

Bisphenol A (BPA) in wastewater has high risks of causing biological feminization. During the wastewater treatment process, large amounts of BPA are accumulated in activated sludge. However, the mechanisms of BPA interacted with activated sludge are still unclear. Especially, the roles of extracellular polymeric substances (EPS), which are major components of activated sludge, in the removal of BPA have never been concerned. In this study, the binding interactions between sludge EPS and BPA are explored combining fluorescence spectroscopy and dynamic light scattering. The thermodynamic mechanisms driving the binding behavior of BPA to EPS are illustrated by isothermal titration calorimetry. The results indicate that the binding interaction between BPA and EPS is spontaneous. BPA mainly binds with the proteins of EPS by hydrophobic association. The random-coiled structure of EPS transforms into relatively condensed cores after binding with BPA. A neutral pH, high ionic strength, and high temperature promote the binding process, facilitating to stabilize BPA in sludge EPS. This study provides new insights into the roles of sludge EPS in the migration and removal of BPA in activated sludge system.

A novel integrated system of three-dimensional electrochemical reactors (3DERs) and three-dimensional biofilm electrode reactors (3DBERs) for coking wastewater treatment.

Treatment of coking wastewater is a great challenge due to their instinct characteristics of high concentration, complex composition and biological toxicity. In this work, a novel integrated system comprising three-dimensional electrochemical reactors (3DERs) and three-dimensional biofilm electrode reactors (3DBERs) in series is developed for coking wastewater treatment. Results indicate that 79.63% of COD as well as 76.30% of total nitrogen could be removed at the low energy consumption of 15.6 kWh/m3. 3DERs mainly contribute to COD and nitrogen removal through electrochemical oxidation/reduction, while 3DBERs are responsible for nitrification process by enriched functional microbes. After treating by the integrated system, only long-chain alkanes are left in the wastewater and the toxicity of effluent is significantly reduced. This integrated 3DERs-3DBERs system exhibits capability of simultaneously eliminating carbonaceous and nitrogenous contaminants in coking wastewater, and greatly saves the energy with synergy of electricity and biofilm.

Enhanced denitrification by nano ɑ-Fe2O3 induced self-assembled hybrid biofilm on particle electrodes of three-dimensional biofilm electrode reactors.

Three-dimensional biofilm electrode reactors (3D-BERs) represent a novel technology for wastewater denitrification. Formation of mature electroactive biofilm on particle electrodes is crucial to realize successful denitrification in 3D-BERs. However, long start-up time and low electroactivity of the biofilm formed on particle electrodes limit the further application of 3D-BERs in wastewater treatment. In this work, self-assembled hybrid biofilms (SAHB) was cultivated on granular activate carbon particle electrodes of the 3D-BER by assembling nano ɑ-Fe2O3 into the biofilm. ɑ-Fe2O3 was selected due to its high affinity to bacterial outer-membrane cytochromes, an important mediator for microbial electron transfer. SAHB formed on particle electrodes were characterized and the denitrification performance of 3D-BERs was also investigated. Results indicate that nano ɑ-Fe2O3 plays positive roles in the start-up of 3D-BER, which captures more microbes into SAHB and constructs thick biofilm on particle electrodes. Special microorganisms with denitrification function related with genera of Hydrogenophaga and Opitutus are distinctively enriched in SAHB. Nano ɑ-Fe2O3 induced SAHB exhibit superior denitrification performance compared to natural biofilm. The average denitrification rate increases from 0.62 mg total nitrogen/L/h for natural biofilm to 1.73 mg total nitrogen/L/h for SAHB, mainly ascribed to accelerated nitrites reduction. Our work provides new technical solution to enhance nitrates removal in 3D-BERs and brings deep insights into application of bio-electrochemical system in wastewater treatment.

Insights into the interactions between triclosan (TCS) and extracellular polymeric substance (EPS) of activated sludge.

Triclosan (TCS) contaminant has aroused wide concerns due to the high risk of converting into toxic dioxin in aquatic environments. During the wastewater treatment process, considerable amounts of TCS are accumulated in activated sludge but the mechanisms are still unclear. Especially, roles of extracellular polymeric substances (EPS), the main components of activated sludge, in TCS removal have never been addressed. In this work, the binding properties of loosely-bound EPS (LB-EPS) and tightly-bound EPS (TB-EPS) of activated sludge to TCS are investigated by fluorescence quenching approach. The influences of aquatic conditions including solution pH, ionic strength and temperature on the interactions between EPS and TCS are explored. Possible interaction mechanisms are discussed as well as the corresponding environmental implication. Results indicate that binding processes of EPS to TCS are exothermic mainly driven by the enthalpy changes. The proteins components in EPS dominate the interactions between EPS and TCS by hydrogen bond and hydrophobic interaction. The binding strength could be improved under the condition of weak alkaline and relative high ionic strength. Generally, LB-EPS exhibit stronger binding ability to TCS than TB-EPS under neutral environment, playing more crucial roles in the binding process. This work highlights the important contributions of EPS to TCS removal, that is beneficial to comprehensively understand the migration of TCS in activated sludge system.

Rapidly probing the interaction between sulfamethazine antibiotics and fulvic acids.

Antibiotics residuals in the environments receive wide concerns due to the high risk of generating antibiotic resistance. Natural organic matters (NOM) existed in the environments are considered to have the capacity of binding with organic contaminants, consequently influencing their speciation and transformation in the natural environments. To assess the migration of antibiotics in the environments, it is crucial to understand the binding mechanisms between NOM and antibiotics, which is still unclear due to the limit of available research methods. In this study, the interaction between fulvic acids (FA), one of the main components of NOM, and sulfamethazine (SMZ) was characterized by nuclear magnetic resonance (NMR) combined with surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) technology. The parameters related to kinetics and thermodynamics of the interaction were determined, and the possible mechanisms driving the interaction were also proposed. In addition, density functional theory (DFT) was used to predict the binding mode between FA and SMZ to reveal the interaction mechanism. Results indicate that FA can effectively bound with SMZ to form a stable complex with a binding constant at the level of 103 L/mol. The kinetic parameters including association and dissociation constants were 29.4 L/mol/s and 6.64 × 10-3 1/s, respectively. Hydrophobic interaction might play significant roles in the binding interaction with ancillary contribution of π-π conjunction arising from the aromatic rings stacking of FA and SMZ.

Cascade Reaction of Propargyl Amines with AgSCF3, as Well as One-Pot Reaction of Propargyl Amines, AgSCF3, and Di- tert-butyl Peroxide: Access to Allenyl Thiocyanates and Allenyl Trifluoromethylthioethers.

An efficient cascade reaction of propargyl amines with AgSCF3 and KBr is developed, affording allenyl thiocyanates at room temperature in high yields. This transformation proceeds via the in situ formation of isothiocyanate intermediates, followed by a [3,3]-sigmatropic rearrangement. The resulting allenyl thiocyanates bearing 3-(electro-donating phenyl) substitutions without isolation can then be reacted with di- tert-butyl peroxide and AgSCF3 under reflux to generate novel allenyl trifluoromethylthioether compounds in moderate to good yields via a "one-pot" three-step process.

Multiple response optimization for high efficiency energy saving treatment of rhodamine B wastewater in a three-dimensional electrochemical reactor.

The removal of high-concentration rhodamine B (RhB) wastewater was investigated in a three-dimensional electrochemical reactor (3DER) packed with granular activated carbon (GAC) particle electrodes. Response surface methodology (RSM) coupled with grey relational analysis (GRA) was used to evaluate the effects of voltage, initial pH, aeration rate and NaCl dosage on RhB removal and energy consumption of the 3DER. The optimal conditions were determined as voltage 7.25 V, pH 5.99, aeration rate 151.13 mL/min, and NaCl concentration 0.11 mol/L. After 30 min electrolysis, COD removal rate could arrive at 60.13% with an extremely low energy consumption of 6.22 kWh/kg COD. The voltage and NaCl were demonstrated to be the most significant factors affecting the COD removal and energy consumption of 3DER. The intermediates generated during the treatment process were identified and the possible degradation pathway of RhB was proposed. It is worth noting that 3DER also showed an excellent performance in total nitrogen (TN) removal under the optimal condition. The activated chlorine generated from chloride had great contributions to eliminate carbon and nitrogen of RhB wastewater. The treatment effluent had a good biodegradability, which was suitable for subsequent biological treatment.

Multiple Fano resonances in plasmonic heptamer clusters composed of split nanorings.

Fano resonances in plasmonic nanostructures are important for plasmon line shaping. Compared to a single Fano resonance, multiple Fano resonances can modify plasmon lines at several spectral positions simultaneously, but they often suffer from weak modulation depths. In this paper, plasmonic heptamer clusters comprising split nanorings are designed to form multiple Fano resonances. Three prominent Fano resonances are observed in the spectra due to the formation of multiple narrow subradiant resonances, and the multiple Fano resonances can be switched on and off by adjusting the polarization direction. Particularly, by modifying the geometry parameters, there is a large tunability of the modulation depth of each Fano resonance. Heptamer clusters comprising split nanorings are highly suitable for plasmon line shaping, and it is expected that they are useful for multiwavelength biosensing and surface-enhanced Raman scattering.

Plasmonic-induced optical transparency in the near-infrared and visible range with double split nanoring cavity.

Plasmonic-induced optical transparency with double split nanoring cavity is investigated with finite difference time domain method. The coupling between the bright third-order mode of split nanoring with one gap and the dark quadrupole mode of split nanoring with two gaps leads to plasmonic analogue of electromagnetically induced transparency. The transparence window is easily modified to the near-infrared and visible range. Numerical results show a group index of 16 with transmission exceeding 0.76 is achieved for double split nanoring cavity. There is large cavity volume of double split nanoring, and the field enhancement inside the cavity is homogenous. Double split nanoring cavity could be a good platform for slow light and sensing applications.

Microstructure and magnetic property of M-type SrRe(x)Fe(12-x)O19 by sol-gel method.

Magnetoplumbite-type (M-type) SrRE(x)Fe(12-x)O19 (RE = La and Ce, x = 0-1.0) powders were prepared by a citric acid sol-gel technique and subsequent heat treatment. The crystal structure, grain size and magnetic properties were investigated by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and vibrating sample magnetometer (VSM). The XRD patterns show that SrRE(x)Fe(12-x)O19 (RE = La and Ce) are mainly hexagonal magnetic plumbite structure, and the average grain size of 30-40 nm was calculated using the Scherer's equation based on the XRD spectrum. Substitution of Fe ion by the rare earth La ion causes a significant decrease in intrinsic coercivity (Hc) and a slight decrease in saturation magnetization (Ms) as shown in the magnetization hysteresis loops. However, the Hc rises gradually in a small wave pattern with the increase of doping content of the rare earth Ce. The relation between the crystal structure and magnetic properties was also studied in this work.