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The interactions between groundwater and its environment was investigated in prairie mining area in this study, through the groundwater system evolutions in mining area before and after the mining actions (from 1973 to 2016) of Yimin coal mine. The results showed that (1) the mining activities of the open-pit coal changed the original reduction environment into the oxidizing environment in the mining area. The pyrite and sulfur-bearing coal in the stratum oxidized, produced acid and triggered a series of subsequent reactions, resulting in the decrease in the pH value of the groundwater in the mining area. The concentration of SO42-, Fe2+, Fe3+, Ca2+ and Mg2+ and the total hardness increased. The regional hydrochemical type evolved from HCO3-Na·Ca·Mg type before mining to the type of HCO3·SO4-Na·Ca·Mg after mining. (2) Coal mining strongly draining underground water accelerated the regional groundwater circulation, and then made the groundwater desalination. The concentrations of TDS, COD and Na++K+ in the mining area all showed a decreasing trend. (3) The coal mining activities made the calcite and dolomite in saturated state under the natural condition of underground water to be unsaturated again. The hydro-geochemical action evolves from double control (water-rock interaction and evaporation-concentration) to water-rock interaction control.

In this investigation, to maximize the desired immunoenhancement effects of PsEUL and stimulate an efficient humoral and cellular immune response against an antigen, PsEUL and the model antigen ovalbumin (OVA) were coupled using the N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) reaction to yield a novel delivery system (PsEUL-OVA). The physicochemical characteristics and immune regulation effects of this new system were investigated. We found the yield of this EDC method to be 46.25%. In vitro, PsEUL-OVA (200 μg mL−1) could enhance macrophage proliferation and increase their phagocytic efficiency. In vivo, PsEUL-OVA could significantly increase the levels of OVA-specific antibody (IgG, IgG1, IgG2a, and IgG2b) titers and cytokine (IL-2, IL-4, IL-6, IFN-γ) levels. Additionally, it could activate T lymphocytes and facilitate the maturation of dendritic cells (DCs). These findings collectively suggested that PsEUL-OVA induced humoral and cellular immune responses by promoting the phagocytic activity of macrophages and DCs. Taken together, these results revealed that PsEUL-OVA had the potential to improve immune responses and provide a promising theoretical basis for the design of a novel delivery system.

DEC-205 receptor-mediated dendritic cells (DC) targeting nanoliposomes is a promising delivery system in eliciting an immune response against pathogens. When this delivery system carries both antigen and immunomodulator, it can effectively regulate the DC function as well as the initial T cell response. To maximize the desired therapeutic effects of Eucommia ulmoides Oliv. polysaccharides (EUPS), and induce an efficient humoral and cellular immune response against an antigen, we encapsulated the OVA and EUPS in long-circling nanoliposomes and conjugated it with anti-DEC-205 receptor antibody to obtain a DEC-205-targeted nanoliposomes (anti-DEC-205-EUPS-OVA-LPSM). The physicochemical properties and immune-modulating effects were investigated in vitro and in vivo by a series of the experiment to evaluate the targeting efficiency of anti-DEC-205-EUPS-OVA-LPSM. In vitro, anti-DEC-205-EUPS-OVA-LPSM (160 μg mL−1) could enhance DCs proliferation and increase their phagocytic efficiency. In vivo anti-DEC-205-EUPS-OVA-LPSM remarkably promoted the OVA-specific IgG and IgG isotypes levels, enhanced the splenocyte proliferation, and induced the NK cell and CTL cytotoxicity. Besides, the anti-DEC-205-EUPS-OVA-LPSM enhanced the maturation of DCs. These findings suggest that the DEC-205 receptor antibody-conjugated EUPS nanoliposome can act as an efficient antigen delivery system to enhance the cellular and humoral immune response by promoting DC maturation. This indicates that the anti-DEC-205-EUPS-OVA-LPSM has significant potential as an immune-enhancing agent and antigen delivery system.

The mannose receptor (MAN-R)-targeted delivery system is commonly used to deliver antigens to macrophages or immature dendritic cells (DCs) to promote the efficiency of antigen presentation. To maximize the enhancement effects of chitosan (CS) and induce an efficient humoral and cellular immune response against an antigen, we encapsulated ovalbumin (OVA) in poly(lactic-co-glycolic acid) (PLGA) microspheres (MPs) and conjugated it with MAN-modified CS to obtain MAN-R-targeting nano-MPs (MAN-CS-OVA-PLGA-MPs). The physicochemical properties, drug loading rate, and immunomodulation activity of MAN-CS-OVA-PLGA-MPs were evaluated. In vitro, MAN-CS-OVA-PLGA-MPs (80 μg mL−1) could enhance the proliferation of DCs and increase their phagocytic efficiency. In vivo, MAN-CS-OVA-PLGA-MPs significantly increased the ratio of CD3+CD4+/CD3+CD8+ T cells, increased CD80+, CD86+, and MHC II expression in DCs, and improved OVA-specific IgG, IgG1, IgG2a, and IgG2b antibodies. Moreover, MAN-CS-OVA-PLGA-MPs promoted cytokine (IFN-γ, IL-4, and IL-6) production in mice. Taken together, our results show that MAN-CS-OVA-PLGA-MPs may act by activating the T cells to initiate an immune response by promoting the maturation of dendritic cells and improving their antigen presentation efficiency. The current study provides a basis for the use of MAN-CS-OVA-PLGA-MPs as an antigen and adjuvant delivery system targeting the MAN-R on the surface of macrophages and dendritic cells.

We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further.

Nitrous acid (HONO) is an important precursor of hydroxyl radical (OH) in the atmosphere. It is also toxic to human health. In this work, HONO concentrations were measured in Shijiazhuang using a Monitor for AeRosols and Gases in ambient Air (MARGA) from December 15, 2019 to March 15, 2020, which covered the heavy air pollution season, the Chinese New Year (CNY) vocation and the Corona Virus Disease-19 (COVID-19) lockdown period. During & after CNY overlapping COVID-19 lockdown, the air quality was significantly improved because of both the emission reduction and the increase in diffusion ability of air masses. The mean HONO concentration was 2.43 ± 1.08 ppbv before CNY, while it decreased to 1.53 ± 1.16 ppbv during CNY and 0.97 ± 0.76 ppbv after CNY. The lockdown during & after CNY reduced ~31% of ambient HONO along with ~62% of NO and ~36% of NO2 compared with those before CNY after the improvement of diffusion ability had been taken into consideration. Heterogeneous reaction of NO2 on ground surface dominated the nocturnal HONO sources, followed by heterogeneous reaction on aerosol surface, vehicle emission, reaction between NO and OH and emission from soil on pollution days throughout the observation. Except for elevated soil emission, other nighttime HONO sources and sinks decreased significantly during & after CNY. The relative importance of heterogeneous reaction of NO2 on surfaces further increased because of both the decrease in vehicle emission and the increase in the heterogeneous conversion kinetics from NO2 to HONO during & after CNY., Graphical abstract Unlabelled Image, Highlights • High concentration of HONO was observed from 0.08 to 12.67 ppbv in Shijiazhuang. • Heterogeneous conversion of NO2 to HONO dominated the nighttime HONO source. • The lockdown during & after CNY reduced ~31% of ambient HONO. • Heterogeneous conversion kinetics from NO2 to HONO increased during & after CNY. • The T and aerosol properties promoted conversion of NO2 to HONO during & after CNY.

The authors report on a low temperature method for large-scale fabrication of cuprous oxide nanocubes deposited on nitrogen-doped reduced graphene oxide (Cu2O/N-RGO). The material was deposited in a glassy carbon electrode (GCE) where it is found to display enhanced electrocatalytic activity for oxidation of diethylstilbestrol (DES). The morphology and composition of Cu2O/N-RGO were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and energy-dispersive spectroscopy. The results demonstrate that the RGO is doped with 3.5% of nitrogen (atomic ratio), and that nanostructured Cu2O particles with controlled cubical morphology and an average size of about 450 nm have been homogeneously deposited on the surface of N-RGO sheets. The oxidation peak of DES was recorded at 0.315 V (vs. saturated calomel electrode) using differential pulse voltammetry. Under the optimal conditions, the modified GCE displays a linear response in the 0.3 to 150 μM DES concentration range, and the limit of detection is 10 nM. The method was applied to the determination of DES in spiked milk, meat and urine samples and gave excellent selectivity, stability and reproducibility.

Nanoporous carbon decorated with Fe nanoparticles (Fe/C) was prepared via in situ carbonization of Fe precursor-encapsulated Zn-based metal organic framework (ZIF8). In the synthetic process, iron precursor (ferrous salt) was mechanically mixed with pre-synthesized ZIF8 taking advantage of the porous characteristic of ZIF8, and then converted to Fe nanoparticles (NPs) at high temperature. The Fe NPs with low content and small size were uniformly embedded in porous graphitic carbon matrix. When the filler loading of Fe/C composite is as low as 15 wt% in paraffin matrix, the absorber exhibited a minimum reflection loss of −29.5 dB at a thickness of 2.5 mm. The strong absorbing capability together with the lightweight feature is closely associated with the well-designed constituent and structure of the composite, which result in good impedance matching and strong electromagnetic energy loss due to the dual-loss mechanism and the synergistic effect between Fe NPs and carbon matrix. This study not only provides a lightweight electromagnetic wave absorbing material, but also offers a general way to prepare metal NPs-nanoporous carbon composite absorber.

The water-soluble polysaccharides were extracted and purified from the root of Chuanminshen violaceum (CVPS). The antioxidant activities of the CVPS were evaluated both with in vitro and in vivo experiments. The results of the in vitro antioxidant assay suggested that the CVPS scavenged DPPH, hydroxyl, and superoxide anion radicals. The oral administration of three different doses of CVPS administered over a period of 6 weeks to D-galactose induced aging mice models, enhanced the activities of T-SOD, Mn-SOD, Cu, Zn-SOD, and CAT, and markedly decreased the content of MDA. Therefore, significant up-regulation of mRNA expression levels of Cu, Zn-SOD, Mn-SOD, CAT, glutathione peroxidase 1 (GPx), thioredoxin 1 (Trx1), and thioredoxin 2 (Trx1) occurred. Finally, the results demonstrated that the CVPS are a novel potential resource for natural antioxidants and anti-aging drugs.

This research aimed to investigate the immunomodulatory effects of phosphorylated Radix Cyathulae officinalis Kuan polysaccharides (pRCPS) in immunosuppressed mice, improving their cellular and humoral immune function. Our results showed that pRCPS increased serum immunoglobulin (IgG, IgA, IgM) concentrations significantly, enhanced splenocyte proliferation, and the thymus and spleen indices. pRCPS also promoted phagocytosis in peritoneal macrophages and enhanced cytokine (IFN-&gamma, IL-2, -4, -5, -6, and -10) serum levels. Importantly, pRCPS increased the proportions of selected T cell subpopulations (CD3+, CD4+, and the CD4+ to CD8+ ratio). Our results revealed that phosphorylation of the polysaccharides promoted their immune-enhancing effects. Thus, pRCPS can enhance cellular and humoral immunity and could be used as an immune-enhancing agent to overcome cyclophosphamide (CY)-induced immunosuppression.

A novel visible-light-responding InVO4-Cu2O-TiO2 ternary nanoheterostructure was designed on the basis of the strategy of energy gap engineering and prepared through ordinary wet chemistry methods. The as-prepared nanoheterostructure was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and diffuse reflectance ultraviolet-visible spectroscopy (UV-vis/DRS). The TEM and HRTEM images of 10%InVO4-40%Cu2O-50%TiO2 confirm the formation of nanoheterostructures resulting from contact of the nanosized TiO2, Cu2O and InVO4 in the size of 5–20 nm in diameter. The InVO4-Cu2O-TiO2 nanoheterostructure, when compared with TiO2, Cu2O, InVO4, InVO4-TiO2 and Cu2O-TiO2, shows significant enhancement in the photocatalytic performance for the degradation of methyl orange (MO) under visible-light irradiation. With a 9 W energy-saving fluorescent lamp as the visible-light source, the MO degradation rate of 10%InVO4-40%Cu2O-50%TiO2 reaches close to 90% during 5 h, and the photocatalytic efficiency is maintained at over 90% after six cycles. This may be mainly ascribed to the matched bandgap configurations of TiO2, Cu2O and InVO4, and the formations of two p-n junctions by the p-type semiconductor Cu2O with the n-type semiconductors TiO2 and InVO4, all of which favor spatial photogenerated charge carrier separation. The X-ray photoelectron spectroscopy (XPS) characterization for the used 10%InVO4-40%Cu2O-50%TiO2 reveals that only a small shakeup satellite peak appears for Cu(II) species, implying bearable photocorrosion of Cu2O. This work could provide new insight into the design and preparation of novel visible-light-responding semiconductor composites.

In this work, a fascinating hybrid based on Ag-Pd bimetallic nanoparticles-decorated graphene oxide (Ag-Pd/GO) has been successfully synthesized by a green and in situ chemical reduction strategy. The resultant hybrid was particularly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet-visible spectroscopy and electrochemical techniques. The morphological results illustrate that Ag-Pd nanoparticles in microspheric appearances are highly dispersed and embedded on the GO layers, resulting in a rough surface and three-dimensional (3D) microstructure with a high Ag-Pd content in the matrix. The as-synthesized 3D Ag-Pd/GO hybrid displays distinctly enhanced electrocatalytic activity for the vanillin oxidation in comparison with that of the monometal-decorated GO, revealing a synergistic effect of the matrix GO and the doped bimetallic Ag-Pd. Therefore, the Ag-Pd/GO composite can be used as an enhanced electrochemical sensing platform for the sensitive determination of vanillin, and the fabricated sensor displays a wide detection range of 0.02–45 μmol dm−3, low detection limit of 5 nmol dm−3 and satisfactory recoveries between 98.8 % and 103.5 %. All the results demonstrate that the 3D hybrids integrated graphene with bimetallic nanoparticles are promising candidates for the development of high-performance electrochemical sensors.

In this paper, we are presenting a facile, green and in situ synthesis strategy for the convenient preparation of well-dispersed gold nanoparticles (AuNPs)-decorated reduced graphene oxide (RGO) without the use of any template molecules and poisonous reductant. The as-synthesized nanocomposite has been detailedly characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis as well as electrochemical technologies. The morphological and structural characterizations illustrate that AuNPs can be efficiently decorated on RGO with the Au content of 20.33 wt% in the matrix and the size of the embedded AuNPs vary between 25 and 40 nm. The electrochemical investigations confirm that the small-sized AuNPs on the RGO film can remarkably boost the electrocatalytic activity for the oxidation of Sudan I, which can be used as an enhanced electrochemical sensing platform for the sensitively detection of the toxicant Sudan I. Moreover, the kinetic parameter studies demonstrate that the Sudan I electro-oxidation at the AuNPs/RGO electrode is a diffusion-controlled process which involves two-electron and two-proton transfer. Under the optimal conditions, a wide linear range of Sudan I detection from 0.01 to 70 μmol L −1 with good linearity ( R 2 = 0.9965, 0.9942) and a low detection limit (1.0 nmol L −1 , S/N = 3) were obtained. In comparison with the existing analogues ever reported, the AuNPs/RGO eletrode exhibits overwhelmingly superior comprehensive properties for the sensitive detection of Sudan I. Finally, the newly developed sensor was applied to quantitative determination of Sudan I in food samples such as chilli powder and ketchup sauce with satisfactory sensitivity, selectivity and reversibility.

A copper nanostructures-graphene oxide (Cu/GO) hybrid as a new electrocatalyst for highly sensitive detection of 2-naphthol (2-NAP) was successfully synthesized by a one-pot and in situ chemical reduction approach. The characterization results reveal that the cubic Cu nanostructures are tightly attached onto the GO sheets in the resulting hybrid. A lower oxidation potential and a larger peak current were observed for the 2-NAP oxidation at the Cu/GO modified electrode, demonstrating the synergistic electrocatalysis from Cu nanostructures and GO sheets. Consequently, the Cu/GO hybrid exhibits a low detection limit (5.0 nM) and wide linear ranges (0.1–4.0 μM and 4.0–130.0 μM) when used as a sensing material for the sensitive detection of 2-NAP. Finally, the fabricated sensor was successfully applied in the detection of 2-NAP in real samples and satisfactory recoveries in the range of 99.3%–104.0% were achieved.

A water-soluble polysaccharide (PSRC) was extracted and purified from the roots of Radix Cyathulae officinalis Kuan, and its chemical characteristics, monosaccharide composition and antioxidant activities were characterized. The average of molecular weight (Mw) of PSRC was 182 kDa. The majority of monosaccharide components of PSRC was glucose (relative mass 48.8%) with lower levels of mannose, rhamnose, galactose, fructose and arabinose (relative mass of 15.7, 14.3, 10.6, 6.1 and 4.5%, respectively). In vitro assays revealed that RSRC possessed potent scavenging activities against DPPH, hydroxyl and superoxide anion radicals. Oral administration of PSRC significantly enhanced antioxidant enzyme activities (including total superoxide dismutase, copper-zinc superoxide dismutase (Cu,Zn-SOD), manganese superoxide dismutase (Mn-SOD), glutathione peroxidase and catalase (CAT)) and capacities of scavenging superoxide anion and hydroxyl radicals, markedly lowered lipid peroxidation formation of malondialdehyde and significantly up-regulated mRNA expressions of Cu,Zn-SOD, Mn-SOD, CAT, glutathione peroxidase 1, thioredoxin 1 and thioredoxin 2, in a d-galactose-induced aging mouse model. Taken together, these findings demonstrate that PSRC could be used as a novel promising source of natural antioxidants and antiaging drugs.

Exploring alternative catalysts with low cost and high catalytic performance to the existing Pt and Pt-based catalysts used in oxygen reduction reactions (ORR) is crucial for the extensive commercial application of metal–air batteries and fuel cells. Herein, we have rationally designed and facilely synthesized a sandwich-structured Co3O4/N-reduced graphene oxide (rGO)/acetylene black (AB) hybrid as a novel ORR catalyst for these renewable energy conversion/storage devices. With N doped to rGO, the size of the Co3O4 nanoparticles decreases pronouncedly and the ORR activity enhances significantly when compared to Co3O4/rGO/AB and Co3O4/rGO. At the same time, rotating-disk electrode measurements reveal that the electrocatalytic reduction process using Co3O4/N-rGO/AB is a 4e transfer pathway, while Co3O4/rGO/AB and Co3O4/rGO hybrids possess a reduction process of dominant 4e with partial 2e. Remarkably, Co3O4/N-rGO/AB displays superior electrochemical performance including activity and durability in comparison with commercially available Pt/C, which is further confirmed by the full cell tests for aluminum–air batteries with them as the electrocatalysts, suggesting that Co3O4/N-rGO/AB is a promising candidate as an alternative to Pt and Pt-based catalysts.

We are presenting a host-guest electrochemical platform for sensing the pollutant 1,3-dinitrobenzene. The method is based on the use of a glassy carbon electrode (GCE) covered with a composite made from multiwalled carbon nanotubes and graphene oxide, and functionalized with β-cyclodextrin (β-CD). The resultant composite was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and electrochemical techniques. The modified GCE was used for the sensitive detection of 1,3-dinitrobenzene (DNB) at working voltages of −355 mV and −483 mV. Due to the specific recognition property of β-CD and the excellent electronic properties of the carbon nanomaterials, the electrode exhibits outstanding supramolecular recognition and enhanced electrochemical response to DNB compared to more conventional electrodes. Under optimum conditions, the peak currents vary linearly with the DNB concentrations in the range from 0.02 to 30.0 μM, and the detection limit is 5.0 nM (at an S/N of 3). The electrode exhibits long-term stability and has been successfully applied to the determination of DNB in spiked soil and water samples.

Phosphorylated Radix Cyathulae officinalis Kuan polysaccharides (pRCPS) was prepared according to three-factors, ratio of STMP (%) and STPP (%), reaction time and reaction temperature, and three level L9(34) orthogonal design. The antiviral activity of nine pRCPS (pRCPS1-9) was systematically evaluated by three methods pre-adding mode, mixed mode, and post-adding mode. Cellular activity was tested by the CCK-8 assay. The results showed that the optimal modification conditions were the ratio of STMP (%) and STPP (%) 1:4, reaction time 2h and reaction temperature 65°C. Six pRCPS (pRCPS1-4, pRCPS7, pRCPS9) exhibited significant anti-viral activity in pre-adding mode (P

In this work, the metallic silver and non-metallic nitrogen co-doped reduced graphene oxide (Ag-N-RGO) was first synthesized by a simple and cost-effective strategy, and then a molecularly imprinted polymer (MIP) was formed in situ at the surface of the prepared composite via electropolymerization of o-phenylenediamine in the presence of salbutamol as the template molecule. The electrochemical characterizations demonstrate that the bifunctional graphene-based composite shows improved catalytic performance than that of pristine graphene doped with one-component or none. The MIP sensor based on Ag-N-RGO owns high porous surface structure, resulting in the increased current response and enhanced recognition capacity than that of non-imprinted sensor. The outstanding performance of the developed sensor derives from the combined advantages of Ag-N-RGO with effective catalytic property and MIP with excellent selectivity. Under the optimal conditions, the electrochemical response of the developed sensor is linearly proportional to the concentration of salbutamol in the range of 0.03-20.00µmolL-1 with a low detection limit of 7 nmol L-1. The designed sensor has exhibited the multiple advantages such as low cost, simple manufacture, convenient use, excellent selectivity and good reproducibility. Finally, the proposed method has been extended for the determinations of salbutamol in human urine and pork samples, and the satisfactory recoveries between 98.9-105.3% are achieved.

Sintered NdDy-Fe-B magnets were made from strip cast flakes by powder metallurgy method. For the magnet with 6 wt.% Dy substituted Nd, a remarkable coercivity increase of 70% was obtained after aging at 900 °C for 2 h and a high coercivity of 23.5 kOe was achieved after aging at 520 °C for 2 h. The average diameter of the oxide particles decreased during the following 900 °C aging treatment. Dy and O diffusion from oxide particles to Nd-rich phase during the aging process was observed. The oxide evolution and Dy element diffusion were helpful to the coercivity enhancement.

Microstructure of the sintered Sm(Co,Fe,Cu,Zr)z magnet was investigated by TEM. Twinning relationships in the rhombohedral Sm2Co17 phase were analyzed. Formation of the twinning is related to the ordered substitution of Sm atoms by Co atomic pairs along different directions in the crystal structure. The atomic structures of twinning were discussed on the base of TEM observation.

Hollow carbon spheres encapsulating magnetite nanocrystals were obtained in high-pressure argon at 600 °C followed by hydrolysis of Fe(NH3)2Cl2 in the hollow interiors at room temperature and heat treatment in argon at 450 °C for 2 h. The structure, morphology, and properties of the products were characterized by x-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and vibrating sample magnetometry. The hollow carbon spheres have diameters of 1–10 μm and wall thicknesses of hundreds of nanometers; the wt% of magnetite nanocrystals in them is ∼13.2%. Equiaxed magnetite nanocrystals range in size from 15 to 90 nm, while acicular magnetite nanocrystals have diameters of ∼20 nm and lengths of 120–450 nm. The saturation magnetization value of the hollow carbon spheres encapsulating magnetite nanocrystals is 4.29 emu/g.

The aim of this study is to investigate the physicochemical properties, monosaccharide composition and immunomodulatory effects of Eucommia ulmoides Oliv. polysaccharide. The average molecular weight (Mw) of EUPS was 11.4632 × 10(5)Da. The monosaccharide components of EUPS were glucose, fructose, mannose, fucose, galactose and arabinose with a relative mass of 36.6%, 16.6%, 14.2%, 15.7%, 9.5% and 7.4%, respectively. In in vitro experiments, EUPS (1.2-75 μg/mL) treatment of dendritic cells (DC) increased their surface expression of MHC I/II, CD80, CD40, and CD86 and indicated that EUPS induced DC maturation. Furthermore, EUPS also significantly enhanced lymphocyte proliferation and significantly enhanced cytokine (IL-4 and IFN-γ) production. In in vivo experiments, our data showed that EUPS could significantly enhance the FMDV-specific IgG, IgG1, IgG2a, and IgG2b antibody titers and T cell proliferation. Together, these results suggest that EUPS is a strong immunostimulant.

In situ TiB whiskers have a hexagonal shape in the transverse section and grow along the [0 1 0]TiB direction. The crystallographic planes of the TiB whiskers in the transverse section are always (1 0 0), (1 0 1) and ( 1 0 1 ¯ ) . The stacking faults in TiB are typically with a stacking fault plane of (1 0 0)TiB. The locations of boron atoms and the lattice mismatch energy between TiB and Ti matrix play key roles in the formation of stacking faults.

The in situ TiB particle reinforced titanium metal matrix composites were prepared using MA followed by park plasma sintering (SPS) with a heating rate of 50 °C/min. The in situ TiB were synthesized by chemical reaction between TiB2 and Ti during the SPS process. The microstructure of the composites sintered at 800, 1000 and 1200 °C were investigated. TiB whiskers are needle-shape and uniformly dispersed in the titanium matrix. The interface between the in situ TiB needles and the titanium matrix is singular and faceted. The composite sintered at 1000 °C has a maximum value of relative density of 99.6%, and good mechanical properties with a flexural strength of 1007 MPa, Young's modulus of 146 GPa and fracture toughness of 8.64 MPa·m1/2, respectively. The fractographs of all composites exhibit a predominantly brittle cleavage fracture mechanism. The elastic modulus of synthesized TiB was estimated.

A six-layer functionally gradient material (FGM) of Ti–TiB–TiB2 was rapidly fabricated by spark plasma sintering (SPS) in vacuum. Both B and TiB2 were used and reacted with Ti to synthesize TiB. Adjusting the content ratio of B to TiB2 in individual layers could control the amount of synthesized TiB by two steps during sintering. The composition and microstructure of the layers in FGM were investigated by XRD, SEM and TEM. The synthesized TiB has needle-like, agglomerated and elongated morphologies. The content of agglomerated TiB increased and that of needle shape TiB decreased with increasing the target TiB volume fraction ranging from 20 to 60%. The elongated TiB was observed in the other two layers with higher target TiB volume fraction, which structure is similar to the agglomerated TiB. The FGM with Ti on one side to Ti–TiB–TiB2 on the other were fabricated at relative low sintering temperature and short dwelling time by spark plasma sintering.

The spark plasma sintered in situ TiB reinforced titanium metal matrix composite was investigated by EBSD and TEM. The sintered composite consists of 30.8% α-Ti phase, 55.7% β-Ti phase and 12.9% in situ TiB reinforcements. Most of the TiB whiskers distributed along phase boundaries between α-Ti and β-Ti, others located within α-Ti and β-Ti grains. Some β-Ti grains with parallel TiB whiskers were observed in the orientation imaging micrograph (OIM). The TiB grows along [010] direction and forms whisker with a hexagonal cross-section. The [010] direction of paralleled TiB whiskers is parallel to [111] direction of cubic β-Ti. High density stacking faults are formed in (100) T i B planes to minimizing the lattice mismatch between TiB and the Ti matrix.

The in situ synthesized TiB reinforced titanium matrix composites have been prepared by spark plasma sintering at 800–1200 °C under 20 MPa for 5 min. The effects of sintering temperature and reinforcement volume fraction on flexural strength, Young’s modulus and fracture toughness of the composites are investigated. The titanium matrix consists of α-Ti and β-Ti phases, and the volume fraction of β-Ti increases with increasing sintering temperatures. The in situ synthesized TiB reinforcements are distributed randomly and uniformly in matrix. The transverse section of TiB has a hexagonal shape aligned along [0 1 0] direction, and the crystallographic planes of the TiB needles are always of the type ( 1 0 0 ) , ( 1 0 1 ) and ( 1 0 1 ¯ ) . The 10 vol% TiB reinforced composite sintered at 1000 °C exhibits excellent mechanical properties. The flexural strength, Young’s modulus and fracture toughness of this composite are 1560 MPa, 137 GPa and 8.64 MPa · m1/2, respectively.

The aim of this study was to investigate whether phosphorylated Radix Cyathulae officinalis Kuan polysaccharides (pRCPS) used as adjuvant with foot-and-mouth disease vaccine (FMDV) can stimulate specific humoral and cellular immune responses in ICR mice. The results demonstrated that pRCPS significantly up-regulated FMDV-specific IgG, IgG1, IgG2b and IgG2a antibody levels and splenocyte proliferation. pRCPS also promoted the killing activities of cytotoxic T lymphocytes (CTL) and natural killer cells (NK). In addition, pRCPS enhanced the expression levels of IL-2, IL-4, and IFN-γ in CD4+ T cells and the level of IFN-γ in CD8+ T cells. Importantly, pRCPS enhanced the expression of MHCII, CD40+, CD86+, and CD80+ in dendritic cells (DCs). This study indicated that phosphorylation modification could increase immune-enhancing activities of RCPS, and pRCPS could promote humoral and cellular immune responses through facilitating DC maturation.

The substitution of cerium, a more abundant rare-earth element, for sintered Nd-Fe-B magnets has drawn intense interest. In the present work, nominal composition of Ce15Nd15FebalB1 (wt. %), with cerium constitutes increased to 50% of the total rare-earth content, was used. And Ce-free Nd30FebalB1 (wt. %) was prepared by the same preparation process as comparison. The microstructure of the sintered magnets has been investigated by means of X-ray diffraction and transmission electron microscope. The results show that there are three kinds of RE-rich phases in the same magnet, i.e., fcc-(Ce,Nd)Ox (a=0.547nm), hcp-(Ce,Nd)2O3 (a=0.386nm, c=0.604nm) and bcc-(Ce,Nd)2O3 (a=1.113nm). Ors of (140)(Ce,Nd)2Fe14B// (1-21)bcc-(Ce,Nd)2O3(∼3°), [001](Ce,Nd)2Fe14B// [-214]bcc-(Ce,Nd)2O3; (01-1)(Ce,Nd)2Fe14B// (101)fcc- (Ce,Nd)Ox(∼2°), [101](Ce,Nd)2Fe14B// [12-1]fcc-(Ce,Nd)Ox were found through selected area electron diffraction (SAED) analysis. According to the analysis, it can be concluded that cerium has partly substituted for neodymium by occupying the corresponding atom sites in the Ce15Nd15FebalB1 magnet, without changing the crystal configuration.

Nano/micro-structured Fe3O4 microspheres among three-dimensional (3D) reduced graphene oxide (rGO)/carbon nanotubes (CNTs) hierarchical networks (the ternary composite is denoted as rGCFs) have been synthesized using a facile, self-assembled and one-pot hydrothermal approach. The rGCFs composite exhibits superior lithium storage performances: initial discharge and charge capacities of 1452 and 1036 mAh g(-1), respectively, remarkable rate capability at current densities from 100 mA g(-1) to 10 A g(-1) and outstanding cycling performance up to 200 cycles. The highly enhanced electrochemical performances of rGCFs depend heavily on the robust 3D rGO/CNTs hierarchical networks, the stable nano/microstructures of active Fe3O4 microspheres and the positive synergistic effects of building components. The systematic structure characterizations and electrochemical investigations provide insightful understanding towards the relationship between structure/morphology and lithium storage performances, which may pave the way for the rational design of composite materials with desirable goals.

On the way to become promising oxygen reduction reaction (ORR) catalysts, the hybrids composed of reduced graphene oxide (RGO) and transition metal oxides are suffering from stacking of RGO sheets. In this work, a Co3O4/RGO/acetylene black (AB) hybrid was successfully synthesized via a facile one-step solution-phase route with sandwiching of AB particles between the RGO sheets during the synthesis of Co3O4/RGO, which can effectively tackle the stacking of RGO sheets. Compared with Co3O4/RGO, Co3O4/RGO/AB-P (mixing AB with the pre-prepared Co3O4/RGO with stirring), Co3O4/RGO/AB-M (mixing AB with Co3O4/RGO during the fabrication of the Co3O4/RGO catalytic layer for ORR) and commercial 10 wt% Pt/C, the Co3O4/RGO/AB hybrid exhibits increases of 50.6%, 32.5%, 37.9% and 8.9% in the ORR current density, respectively. This indicates that the introduction strategy of AB to Co3O4/RGO plays a vital role in the enhancement of ORR catalytic activity. Moreover, the Co3O4/RGO/AB hybrid shows a subtle ascending trend in the ORR current density during continuous operation for 72 000 s, while Pt/C exhibits a 9.0% decrease. The exceptional ORR catalytic performance of Co3O4/RGO/AB can also be ascribed to the large specific surface area, well-anchored Co3O4 nanoparticles on the RGO sheets, and low ohmic and kinetic impedances for ORR. We hope this work will be conducive for the extensive commercial applications of fuel cells.

Various transition metal oxide-based nanostructures with outstanding lithium-ion storage properties are considered as the most appealing candidates to substitute conventional carbonaceous anode materials in lithium-ion batteries. However, the rational design and tailored synthesis of hybrid materials with specific components, morphologies and structures are crucial to achieving superior electrochemical performances. In this paper, we have designed the synthesis of nanostructured anatase TiO2-modified iron oxides (FexOy) on/among carbon nanotubes (CNTs) (denoted as TFCs) by a simple and inexpensive bottom-up assembly approach. In the as-designed TFCs, TiO2 modifications include two forms: TiO2-coated on FexOy, and TiO2 nanoparticles distributed among TFCs, which play a significant role in avoiding the aggregation and pulverization of the FexOy nanoparticles. With the introduced TiO2 as a buffer material, and the CNTs framework as a porous 3D conducting/buffering network and an effective substrate for anchoring FexOy nanoparticles, as compared to all of the existing analogues reported, the as-designed TFCs display overwhelmingly superior Li+ storage properties, to be specific, good capacity retention with 922 mAh g−1 at 500 mA g−1 and 1089 mAh g−1 at 200 mA g−1, excellent rate capability with current densities varying from 50 mA g−1 to 10 A g−1 and remarkable cycling performance with the capacity increased from 584 to 922 mAh g−1 at 500 mA g−1 over 450 cycles (remaining stable at around 920 mAh g−1 after the 420th cycle) after the rate tests for the same tested cell. We believe that the fascinating TFCs as well as other hybrids with similar structures can be easily extended for diverse applications, such as supercapacitors and catalysts, thus exhibiting broad prospects in the design of high-performance hybrid materials.

The ingot and fast-cooling Sm2Co17 alloys were fabricated by arc-melting and suction casting methods, respectively. Magnetic properties of the fast-cooling Sm2Co17 alloy are enhanced than the ingot samples. The fast-cooling alloy with a diameter of 6mm has a high coercivity of 16.47kOe at room temperature. Moreover, the fast-cooling samples show a better performance than the ingot and commercial alloy, a high coercovity can be maintained below 500 °C and remain 70% of the value when temperature increased to 600°C.