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Purpose The application of metagenomic next-generation sequencing (mNGS) in the diagnosis of tuberculous meningitis (TBM) remains poorly characterized. Here, we retrospectively analyzed data from patients with TBM who had taken both mNGS and conventional tests including culture of Mycobacterium tuberculosis (MTB), polymerase chain reaction (PCR) and acid-fast bacillus (AFB) stain, and the sensitivity and specificity of these methods were compared. Methods We retrospectively recruited TBM patients admitted to the hospital between December 2015 and October 2018. The first collection of cerebrospinal fluid (CSF) samples underwent both mNGS and conventional tests. In addition, patients with bacterial/cryptococcal meningitis or viral meningoencephalitis were mNGS positive controls, and a patient with auto-immune encephalitis was an mNGS negative control. Results Twenty three TBM patients were classified as 12 definite and 11 clinical diagnoses, which were based on clinical manifestations, pathogen evidence, CSF parameters, brain imaging, and treatment response. The mNGS method identified sequences of Mycobacterium tuberculosis complex (MBTC) from 18 samples (18/23, 78.26%). In patients with definite TBM, the sensitivity of mNGS, AFB, PCR, and culture to detect MTB in the first CSF samples were 66.67, 33.33, 25, and 8.33%, respectively. The specificity of each method was 100%. Among the four negative mNGS cases (4/23, 17.39%), three turned out positive by repeated AFB stain. The agreement of mNGS with the total of conventional methods was 44.44% (8/18). Combination of mNGS and conventional methods increased the detection rate to 95.65%. One patient was diagnosed as complex of TBM and cryptococcal meningitis, in which AFB stain and cryptococcal antigen enzyme immunoassay were positive and the DNA of Cryptococcus neoformans was detected by mNGS. Conclusion Our study indicates that mNGS is an alternative method to detect the presence of mycobacterial DNA in CSF samples from patients with TBM and deserves to be applied as a front-line CSF test.

The paste thickness is an essential parameter related to mix proportion and properties of concrete. The quantitative models of paste thickness could be classified as volume-based paste thickness (VPT) and surface area-based paste thickness (SPT), while the widely-used SPT doesn’t consider the dilatation effect of aggregate. The aim of this paper is to modify the SPT model by comparing the derivation of different quantitative models, then the mortar thickness is calculated and its relationship with compressive strength of concrete is investigated. Taking the dilatation effect ( λ ) into account, a modified SPT model is derived, which also could be more accurate than VPT as a parameter in mix design of concrete. Regarded the concrete as two-phase composites of mortar and coarse aggregate, the compressive strengths of mortar and concrete conform to the hyperbolic model proposed by de Larrard, and the interlocking-effect of coarse aggregate is quantitatively characterized. Besides, the compressive strength of concrete is linear to −0.13 power of mortar thickness, which provides a foundation for the prediction of compressive strength and the mixture design of concrete.

High flowability and early strengthening properties of self-levelling mortar (SLM) could greatly boost construction efficiency and save lots of labor force and materials costs. In this paper, absolute volume method was applied to design the mix proportions of SLM prepared by curshed sand. Further, the relationships between the flowability, strength of mortar and the calculated coating paste thickness MAPT under several paste to aggregate volume fractions ( V p / V a ) were analyzed. Subsequently, ultrafine cement, silica fume and sodium sulfate were added to improve the early-age strength of SLM, and their effects on the flowability and rheological properties were also discussed. Finally, the XRD, TG-DTG analysis and SEM images were applied to study the microstructure of hardened matrix. Results showed that a linear equation could be employed to express the relationship between fluidity and the MAPT and a quadratic polynomial relationship for strength. Rheological parameters were increased by the ultrafine cement and silica fume, while sodium sulfate could enhance the rheological properties. It was found that combination admixture of silica fume and sodium sulfate could improve the mechanical strength greatly. And more C-S-H gels and higher chemical combined water (CCW) content were generated in the sample modified by the combination admixture.

Dual improvement on electronic conductivity and ionic conductivity of TiNb2O7 (TNO) is of great significance for realizing high-performance lithium-ion batteries. In this work, the V5+-doped TNO microspheres (denoted as Vx-TNOMs, x = 0, 0.015, 0.030 and 0.045) were synthesized via a simple solvothermal approach. X-ray diffraction coupled with Rietveld refinements and Raman spectra analyses verified that V5+ not simply possessed substitution doping mode but also inserted into the interstices of the TNOMs lattice. The density functional theory (DFT) calculations indicated that the improved electronic conductivity could originate from the formation of impurity bands after the V5+ doping. Meanwhile, the climbing image-nudged elastic band (CI-NEB) demonstrated that a TNOMs framework with faster ion transport pathways is achieved by the V5+ doping. Served as anode material of lithium-ion batteries, the V0.030-TNOMs electrode presents an impressive discharge capacity of 163.5 mAh/g at 10 C and long cycle life up to 2000 cycles with a capacity fading of merely 0.014% per cycle. Furthermore, the full battery employing V0.030-TNOMs as an anode and commercial LiCoO2 as a cathode exhibits superior electrochemical performances with promising application prospect. Our present study sheds new light on constructing high-performance electrodes for electrochemical energy storage.

Due to the particular nature of ownership, the motivations for state-owned enterprises to participate in the mixed ownership M&A include not only the realization of corporate capital appreciation and value creation, but also some strategic factors at the national level, such as concentrating state-owned economic power to promote the development of the industry and maintaining stable social development. Based on the characteristics of the self-development of state-owned enterprises and the maximization of interests, this paper constructs the evaluation system of trust mechanism from five dimensions of shareholders’, creditors’, suppliers’, buyers’ and enterprises’ sincerity; constructs the evaluation system of innovation mechanism from three dimensions of technological innovation ability, market competitiveness and sustainable development ability; and the evaluation system of the mixed ownership M&A value of state-owned enterprises from four dimensions of Tobin’s Q, operating cash flow, return on total assets and corporate governance.

This study describes the synthesis of Ag–bismuth vanadate (Ag–BiVO4) microspheres, a highly efficient visible light photocatalyst for the degradation of methylene blue, via a one-step hydrothermal method. Multiple characterization techniques showed that bulk, monoclinic, needle-like BiVO4 and Ag nanoparticles (50 nm diameter) formed microspheres (3–7 μm diameter) with a uniform size distribution. Compared with pure BiVO4, the Bi–Ag microspheres showed significantly enhanced absorption of visible light (480 to 700 nm) during measurement of UV-Vis diffuse reflectance. Electron paramagnetic resonance measurements indicated that Ag doping enhanced photocatalytic performance because it facilitated separation and transfer of photo-generated electrons and electron holes. This study provides a cost-effective approach for synthesizing Bi–Ag microspheres with enhanced photocatalyst performance for environmental and energy applications.

A β-NaYF4:Ho3+@TiO2 core–shell microcrystal photocatalyst was synthesized using a hydrothermal method followed by hydrolysis of tetra-n-butyl titanate (TBOT), with polyvinylpyrrolidone K-30 (PVP) as the coupling agent. X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, fluorescence and Raman spectrometry, ultraviolet-visible diffuse reflectance spectroscopy, and electron spin resonance were used to characterize the photocatalyst. It was found that the core's hexagonal phase NaYF4:Ho3+ microcrystals were evenly coated by a TiO2 shell and that the average β-NaYF4:Ho3+ microcrystal length was roughly 9 μm with a diameter of about 3.8 μm. After doping which caused a slight increase, the average thickness of the TiO2 shells was about 50 nm. Because Ho3+-single-doped β-NaYF4:Ho3+@TiO2 displays strong visible absorption peaks at 450, 537, and 642 nm, we chose 450, 532, and 633 nm to be the excitation wavelengths. We found ultraviolet emission bands at 290 nm (5D4 → 5I8) and 389 nm (3K7/5G4 → 5I8). Also, the energy transfer from β-NaYF4:Ho3+ to anatase TiO2 was confirmed. Rhodamine B (RhB) was used as a model pollutant to investigate the photocatalytic activity of β-NaYF4:Ho3+@TiO2 microcrystals under Xe lamp (500 W) irradiation. This investigation showed an advanced visible-light-driven catalyst, with about 67% of the RhB decomposed after 10 h. Compared with the blank experiment, the efficiency was obviously improved. Recycling experiments showed that the β-NaYF4:Ho3+@TiO2 composite still presented significant photocatalytic activity after four successive cycles. Finally, we investigated the β-NaYF4:Ho3+ upconversion (UC) mechanism and the β-NaYF4:Ho3+@TiO2 core–shell microcrystal visible-light-responsive photocatalytic mechanism. Understanding the visible-light-responsive photocatalytic mechanism will help to improve the structural design and functionality of this new type of catalytic material.

In order to realize high efficiency visible-light absorption and electron–hole separation of bismuth vanadate (BVO), we synthesized carbon-doped BVO (C-BVO) with high visible-light absorption behavior. We used polyvinylpyrrolidone K-30 as a template and L-cysteine as the carbon source in a one-step hydrothermal synthesis method, and then obtained the carbon-doped BVO@multi-walled carbon nanotubes (C-BVO@MWCNT) by a two-step method. The carbon nanotubes were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, specific surface area, electron spin resonance, and transient photocurrent responses. The XRD analysis confirmed that all photocatalysts were in the same crystal form with a single monoclinic scheelite structure. Combining this with the other characterization results, we showed that the carbon element was successfully doped in BVO and the resulting C-BVO was successfully coupled with multi-walled carbon nanotubes. The removal ratio of rhodamine B by C-BVO@MWCNT was much higher than those by BVO and C-BVO under visible-light irradiation. Recycling experiments verified the stability of C-BVO@MWCNT, which was proved to offer excellent adsorption, strong visible-light absorption behavior, and high electron–hole separation efficiency. Such properties are expected to be useful in practical applications.

The electrochemical performance and safety of LiNi0.8Co0.15Al0.05O2 (NCA) were improved by LiFePO4 (LFP) using a facile way, and the effects of LFP were investigated. Compared to the pristine NCA, 20 wt% of LFP enhanced the electrochemical performance and safety by decreasing the stress value by about 62.9% at 1C and moving the exothermic peak to the high-temperature zone by about 16.8 °C. The discharge capacity and capacity retention ratio were improved by 19% and 17% at 1C, respectively. The structure changes at different charge states and enhanced mechanisms were discussed. The facile strategy is attractive for the applications of energy materials.

An iron-base phosphate Na4Fe3(PO4)2(P2O7) nano-sphere growing on the multi-walled carbon nanotubes (MCNTs) is scalable synthesized via a convenient spray drying way. The Na4Fe3(PO4)2(P2O7)@MCNTs composite as cathode material for sodium-ion battery (SIBs) exhibits a high discharge capacity of 115.7 mA h g−1 at 0.1 C and an outstanding cycle stability with a with a capacity retention of 95% after 1200th at 2 C rate. It also shows an excellent rate capability with a capacity of 62.8 mA h g−1, even at high rate of 20 C. The outstanding electrochemical performance of Na4Fe3(PO4)2(P2O7)@MCNTs cathode are attributed to its' particular P2O7 dimers for reducing the rotation/distortion and higher electronic conductivity improves by MCNTs. A sodium-ion battery using the Na4Fe3(PO4)2(P2O7)@MCNTs cathode and the hard carbon anode shows a working voltage of 3.04 V with a specific energy of 210 Wh Kg−1 bases on the total weight of both electrode materials.

A pervious concrete with carbonated ground steel slag powder as binder and crushed steel slag as aggregate was prepared, which provided the key material for construction of sponge city and explored a new approach to massively utilize steel slag. This paper presented series of experimental studies on the properties of steel slag carbonized consolidation matrix and carbonated steel slag pervious concrete. Results indicated that the phosphogypsum promoted the carbonization ratio of steel slag. When the content of phosphogypsum was 2.5%, strength and carbonization ratio of carbonated steel slag from pressing formation reached 82.6 MPa and 52.1% respectively. The main product of the carbonated steel slag was calcite and C–S–H. The strength and porosity of carbonated steel slag pervious concrete reached 9.4 MPa and higher than 20% respectively. And it also had a good plantability when it is used in sponge city construction. Compared with ordinary pervious concrete, carbonated steel slag pervious concrete saved 75.8% cost of materials, was 100% made of solid waste and absorbed around 100 kg/m3 of CO2, which turns out to be a green and high-efficiency approach to utilize the solid waste steel slag, saving the natural resource and reducing the carbon footprint of the construction of sponge city.

Long-term tillage practices can shape unique soil environments. The heavy disturbance caused by plow tillage can cause a series of ecological problems; thus, zero tillage is widely used as a low-disturbance conservation practice. However, it is unclear how tillage practices with different soil disturbances affect the rhizosphere microbial communities of crops during the succession of their growth stages on a background of continuous management. The rhizosphere environment may shape different microbial communities depending on the growth stage, and soil disturbance before crop planting may also have a lasting effect on the microbial community. In this study, we used 16S rRNA sequencing to analyze the assembly and composition of the rhizosphere bacterial communities of wheat at different growth stages under different tillage practices. The results showed that under different tillage practices and growth stages, the assembly and composition of the rhizosphere bacterial community changed significantly. Rhizosphere bacterial communities under the zero tillage condition appear to be more stable than those under the plow tillage condition, which may be related to the relatively low soil disturbance and unique rhizosphere environment under the zero tillage condition. In addition, our results further suggest that several soil variables may affect bacterial community assembly and composition.

Different tillage practices elicit various degrees of soil disturbance and significantly affect the community structure of soil microbes, especially rhizosphere microbes. However, little is known about the effects of tillage on community assembly and composition in the rhizosphere of arbuscular mycorrhizal fungi (RAMF). In this study, we investigated wheat RAMF communities under long-term different tillage patterns in an agroecosystem. The results showed that soil disturbance caused by tillage resulted in significant changes in RAMF communities, and this change varied with the degree of disturbance. Soil total nitrogen was the most relevant abiotic factor to RAMF communities. Notably, as a biotic selection factor, we found that cohesion of communities could also explain the changes in RAMF taxonomic and phylogenetic composition, which have not been revealed by other studies. Meanwhile, by analyzing the RAMF community assembly process under tillage practices, we found that stochastic processes dominated the assembly of RAMF communities under different tillage practices, and with the reduction of disturbance degree, the process occupied an increasingly important position. Overall, the structure and assembly process of the RAMF community in the rhizosphere varied with the degree of soil disturbance caused by tillage. These findings may provide more insights on underground processes and aid in the development of conservation tillage as a sustainable agricultural practice.

The present study investigates the microbial (bacterial and fungal) community diversity and carbon substrates utilization in rhizosphere and bulk soil under three tillage practices (chisel plow, zero, and plow tillage) by using high-throughput sequencing technology and community-level physiological profiles. Conservation tillage practices increased the DOC, SOC, and invertase activity in bulk soil compared with conventional tillage. Tillage disturbances changed the soil microbial phylogenetic composition and utilization abilities of carbon substrates, and there was a significant positive correlation between soil microbial alpha diversity and catabolic diversity under different tillage practices. The soil microbial phylogenetic composition was significantly different with different soil types (rhizosphere and bulk) under three tillage practices, which had great influence on carbon substrate utilization. The soil physicochemical parameters were significantly correlated with microbial taxonomy composition. Structural equation model (SEM) analysis suggested that the relative abundances of Proteobacteria (Alpha- and Betaproteobacteria), Bacteroidetes, Capnodiales, and Pleosporales in the rhizosphere helped in the utilization of amino acids, carbohydrates, and carboxylic acid under different tillage practices. Our results suggested that conservation tillage practices and crop root activities modified soil physicochemical parameters and enrich soil nutrient conditions, which contributes to differences of soil microbial phylogenetic and taxonomic compositions, thereby increasing copiotrophic microbial populations in the rhizosphere and enhances metabolic capacities. Thus, these results can improve our understanding of the roles of conservation tillage in changing soil microbial community and catabolic diversity, as well as can help to establish a profitable agroecosystem to enhance soil nutrient conditions and modify soil microbial ecology, in turn improving plant production sustainability.

The welding of glasses is widely used in many fields, such as optics, microfluidics, and microelectromechanical systems. In this paper, two pieces of 1 mm soda lime glass substrates were welded using a 1064 nm nanosecond laser assisted with a 14 nm titanium-coated thin film coating. Results show that after the laser irradiation, the welded area becomes highly transparent much like uncoated glass. The maximum change rate of transmittance of the welded zone is 8.88% in the wavelength range of 400–1800 nm, compared to a piece of 2 mm glass substrate. The chemical reaction process between the titanium film and the glass substrate of the highly transparent welded sample was analyzed by x-ray photoelectron spectroscopy. Welded quality and shear strength were characterized by scanning acoustic microscopy and shear tests.

With the advent of social aging, the development of intelligent multifunctional nursing beds that are suitable for hospitals, nursing homes, homes and the like has a wide range of applications, this paper presents an intelligent nursing bed design based on Internet of Things technology. The design uses STM32F103 as the central processor. The design is divided into nursing bed module based on tri-fold structure, central control module based on data processing, weight scale module based on weight detection, power supply module based on system power supply and host computer module based on user operation. The design uses a closed control mode, greatly improving the bed control accuracy. Experimental tests showed that under the action of the intelligent control bed control system, the error rate of bed position information driven bedboard can be less than 2%, which has high accuracy and stability.

In this work, we demonstrate a novel and simple approach for fabrication of the complex three-dimensional (3D) diatomite/manganese silicate nanosheet composite (DMSNs). The manganese silicate nanosheets are uniformly grown on the inner and outer surface of diatomite with controllable morphology using a hydrothermal method. Such structural features enlarged the specific surface area, resulting in more catalytic active sites. In the heterogeneous Fenton-like reaction, the DMSNs exhibited excellent catalytic capability for the degradation of malachite green (MG). Under optimum condition, 500 mg/L MG solution was nearly 93% decolorized at 70 min in the reaction. The presented results show an enhanced catalytic behavior of the DMSNs prepared by the low-cost natural diatomite material and simple controllable process, which indicates their potential for environmental remediation applications.

In this study, a novel reactor using a biocathode microbial fuel cell and photocatalysis was designed for simultaneous nitrogen removal and power generation in the absence of organic compounds. To enhance the redox potential of microbial fuel cells, two pieces of conductive glass coated with TiO2 and SiO2 were attached to the anode and cathode electrodes, respectively. Nitrification and denitrification occurred in the anode and cathode chambers, respectively. As the sole electron donor, ammonium supported the current production without organic compounds in the anode chamber. In the cathode chamber, the denitrification process occurred with nitrate as the electron acceptor. Moreover, with the effect of ultraviolet irradiation of the conductive glasses, which is in contact with the anode and cathode, nitrification and power generation were both enhanced. The nitrification rate was increased from 0.58 to 1.34 mg L–1 h–1, and the denitrification rate was increased from 0.5 to 1.2 mg L–1 h–1. In addition, the ...

Many studies have focused on the use of BiVO4 as a photocatalyst, but few have investigated the production of free radicals during the photocatalytic process. Following synthesis of flowerlike BiVO4 and characterization by X-ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) Scanning electron microscopy (EDX), UV-Vis and XPS, we successfully prepared BiVO4. Then we used electron spin resonance (ESR) to determine the production and degradation of individual active free radicals, including the superoxide radical (·O2-) and the hydroxyl radical (·OH). In the first experiment, we used ESR to detect the signals of free radicals (·O2- and ·OH) under varying oxygen conditions. The results shown that in addition to production by ·O2-, ·OH could also be produced by oxidation of h+ to OH−. In the next experiment, we detected ·OH under varying pH to identify the result of the first experiment, and found that signal intensities increased with increasing pH, indicating the mechanism for ·OH production. Finally, we conducted a trapping experiment to examine free radical degradation mechanisms. We identified ·OH and h+ as the main active free radicals and showed the complete production about ·OH. These results improve current knowledge of free radical production mechanisms, which can be used to enhance the photocatalytic performance of BiVO4.

The band gaps of bismuth vanadate (BiVO4) and bismuth sulfide (Bi2S3) are about 2.40 eV and 1.30 eV, respectively. Although both BiVO4 and Bi2S3 are capable of strong visible light absorption, electron–hole recombination occurs easily. To solve this problem, we designed a one-step hydrothermal method for synthesizing a Bismuth sulfide (Bi2S3)/Bismuth vanadate (BiVO4) heterojunction using polyvinylpyrrolidone K-30 (PVP) as a structure-directing agent, and 2-Amino-3-mercaptopropanoic acid (l-cysteine) as a sulfur source. The pH of the reaction solution was regulated to yield different products: when the pH was 7.5, only monoclinic BiVO4 was produced (sample 7.5); when the pH was 8.0 or 8.5, both Bi2S3 and BiVO4 were produced (samples 8.0 and 8.5); and when the pH was 9.0, only Bi2S3 was produced (sample 9.0). In sample 8.0, Bi2S3 and BiVO4 were closely integrated with each other, with Bi2S3 particles formed on the surface of concentric BiVO4 layers, but the two compounds grew separately in a pH solution of 8.5. Visible-light photocatalytic degradation experiments demonstrated that the degradation efficiency of the Bi2S3/BiVO4 heterojunction was highest when prepared under a pH of 8.0. The initial rhodamine B in the solution (5 mg/L) was completely degraded within three hours. Recycling experiments verified the high stability of Bi2S3/BiVO4. The synthesis method proposed in this paper is expected to enable large-scale and practical use of Bi2S3/BiVO4.

The band gaps of bismuth vanadate (BiVO4) and bismuth sulfide (Bi2S3) are about 2.40 eV and 1.30 eV, respectively. Although both BiVO4 and Bi2S3 are capable of strong visible light absorption, electron–hole recombination occurs easily. To solve this problem, we designed a one-step hydrothermal method for synthesizing a Bismuth sulfide (Bi2S3)/Bismuth vanadate (BiVO4) heterojunction using polyvinylpyrrolidone K-30 (PVP) as a structure-directing agent, and 2-Amino-3-mercaptopropanoic acid (l-cysteine) as a sulfur source. The pH of the reaction solution was regulated to yield different products: when the pH was 7.5, only monoclinic BiVO4 was produced (sample 7.5); when the pH was 8.0 or 8.5, both Bi2S3 and BiVO4 were produced (samples 8.0 and 8.5); and when the pH was 9.0, only Bi2S3 was produced (sample 9.0). In sample 8.0, Bi2S3 and BiVO4 were closely integrated with each other, with Bi2S3 particles formed on the surface of concentric BiVO4 layers, but the two compounds grew separately in a pH solution of 8.5. Visible-light photocatalytic degradation experiments demonstrated that the degradation efficiency of the Bi2S3/BiVO4 heterojunction was highest when prepared under a pH of 8.0. The initial rhodamine B in the solution (5 mg/L) was completely degraded within three hours. Recycling experiments verified the high stability of Bi2S3/BiVO4. The synthesis method proposed in this paper is expected to enable large-scale and practical use of Bi2S3/BiVO4.

To achieve an efficient visible-light absorption and degradation of bismuth vanadate (BiVO4), in this paper, a carbon-doped (C-doped) nanosheets monoclinic BiVO4 (m-BiVO4), with thicknesses within 19.86 ± 8.48 nm, was synthesized using polyvinylpyrrolidone K-30 (PVP) as a template and l-carbonic as the carbon source by one-step hydrothermal synthesis method. This C-doped BiVO4 in three-dimensional (3D) hierarchical structure enjoys high visible-light photocatalytic property. The samples were characterized using x-ray diffraction, scanning electron microscope, Raman spectra, energy dispersive spectrometer, transmission electron microscope, x-ray photoelectron spectroscopy, UV–Vis diffused reflectance spectroscopy, specific surface area, electron spin resonance, and transient photocurrent response, photoluminescence spectra, and incident-photon-to-current conversion efficiency, respectively. What is more, we studied the C-doping effect on the band-gap energy of BiVO4 based on First-principles. X-ray diffraction analysis showed that all photocatalysts were in the same single monoclinic scheelite structure. According to the other characterization results, the element C was successfully doped in BiVO4, resulting in the 3D hierarchical structure of C-doped BiVO4 (P-L-BiVO4). We speculated that it could be the directional coalescence mechanism by which the l-cysteine promoted the two-dimensional growth and C-doping process of BiVO4, thus leading to the formation of nanosheets which were then promoted into 3D self-assembly by PVP and the shortening of the band gap. Among all samples, P-L-BiVO4 can make the highest removal ratio of rhodamine B under visible-light irradiation. The stability of P-L-BiVO4 was verified by recycle experiments. It showed that P-L-BiVO4 had strong visible-light absorption behavior and high electron–hole separation efficiency and stability, making a significant advantage in actual situation.

We prepared a unique leaf-like BiVO4-reduced graphene oxide (BiVO4-rGO) composite with prominent adsorption performance and photocatalytic ability by a single-step method. Multiple characterization results showed that the leaf-like BiVO4with average diameter of about 5 um was well dispersed on the reduced graphene oxide sheet, which enhanced the transportation of photogenerated electrons into BiVO4, thereby leading to efficient separation of photogenerated carriers in the coupled graphene-nanocomposite system. The characterization and experiment results also indicated that the outstanding adsorption ability of such composite was closely associated with the rough surface of the leaf-like BiVO4and doped rGO. The surface photocurrent spectroscopy and transient photocurrent density measurement results demonstrated that the doped rGO enhanced separation efficiency and transfer rate of photogenerated charges. As a result, the BiVO4-rGO exhibited higher photocatalytic capacity toward the degradation of rhodamine B dye under visible-light irradiation compared with pure BiVO4and P25.

Tin anode slime, a secondary resource containing Sn, was used as a raw material in the preparation of CaSnO3 via the processes of soda roasting, alkaline leaching, and precipitation. The effects of roasting, leaching, and precipitation on the extraction of tin from slime were investigated in detail. The following optimum conditions were identified: Na2CO3/tin anode slime mass ratio of 1:1, roasting temperature of 1000 °C, roasting time of 45 min, charcoal powder dosage of 20%, NaOH concentration of 2 mol/L, liquid-to-solid ratio of 14:1, leaching temperature of 65 °C, leaching time of 90 min, CaO/Sn mole ratio of 3.5:1, precipitation temperature of 85 °C, and precipitation time of 120 min. Under these conditions, more than 95% of Sn was extracted from tin anode slime after roasting and leaching, in which Sn was converted into Na2SnO3, which enhanced Sn extraction. Furthermore, more than 99% of Sn was precipitated from the leach solution via the reaction with CaO. The proposed method exhibits advantages of low pollution, low cost, and high leaching rate, when compared with the conventional preparation of CaSnO3 or treatment of tin anode slime.

To further enhance the photocatalytic performance of BiOCl, a facile hydrothermal reduction reaction was used to synthesize the reduced graphene oxide- (rGO-) modified ternary compound photocatalyst β-NaYF4:Yb3+, Er3+@BiOCl-rGO (NYF–Bi-rGO). rGO prepared using a hydrothermal method showed good conductivity. Furthermore, the specific surface area of NYF-Bi-rGO was 20-fold larger than that of NYF, which is a quality that could prove highly advantageous for use in pollutant adsorption. In addition, the ternary photocatalytic system produced by rGO increased the absorption intensity of NYF-Bi in the visible light region, and caused a red-shift of the entire absorption cross-section. In particular, analysis of carrier migration showed the introduction of rGO promoted the separation of the photoelectron-hole pairs of BiOCl, inhibited its recombination and improved the photocatalytic efficiency of the ternary photocatalyst NYF-Bi-rGO.

Three-dimensional (3D) multi-cellular aggregates (MCAs), as a model scaffold-free tissue construct, are useful for engineering cell-dense and matrix-poor tissues for repair and regeneration applications. To facilitate rapid MCA formation with high degrees of linker consistency and performance, we synthesized a class of dendrimer hydrazides with 8, 16 and 32 arms that can react with the aldehyde on the modified cell surfaces to form MCAs. DAB-AM-16 hydrazide with 32 arms demonstrated the best cell aggregation ability as compared to the dendrimer hydrazides with fewer arms, facilitating MCA formation at lower linker concentrations, minimizing cytotoxicity. Characterization of the MCAs formed with 2 microm of DAB-AM-16 hydrazide indicated that the cells proliferated well, maintained 3D cell-cell interaction and 3D cell morphology even as the inter-cellular linker gradually disappeared from the cell surfaces. Cells cultured as MCAs also demonstrated improved cell functions than the cells cultured in 2D monolayer. The dendrimer hydrazides would be a class of consistent, economical, and high performance multivalent transient inter-cellular linkers useful in forming scaffold-free 3D tissue constructs for soft-tissue engineering and regenerative medicine.

A Fe61Co10Zr5W4B20 bulk metallic glass (BMG) with a diameter of 2 mm was prepared by using copper mould suction casting. The X-ray diffraction (XRD), differential scanning calorimetry (DSC), micro-hardness and compression tests were adopted to investigate the structure, thermal stability, especially, the effect of heat treatment on the micro-hardness and compression strength of this BMG. The BMG exhibits micro-hardness of about 1 207 Hv and compression fracture strength of about 1 707.6 MPa. After being annealed below the onset of crystallization temperature, the micro-hardness almost keeps constant. But after being annealed above the peak of crystallization temperature, the micro-hardness increases firstly and then declines gradually with the elongation of annealing time. However, annealed for the same period of time, the micro-hardness will increase with the rise of annealing temperature, while the compression fracture strength will apparently decrease.

Correction for ‘One-step synthesis of composite material MWCNT@BiVO4 and its photocatalytic activity’ by Deqiang Zhao et al., RSC Adv., 2017, 7, 33671–33679.

Three-dimensional (3D) in vitro cultures are recognized for recapitulating the physiological microenvironment and exhibiting high concordance with in vivo conditions. In cancer research, the multi-cellular tumor spheroid (MCTS) model is an established 3D cancer model that exhibits microenvironmental heterogeneity close to that of tumors in vivo. However, the established process of MCTS formation is time-consuming and often uncontrolled. Here, we report a method for engineering MCTS using a transient inter-cellular linker which facilitates cell-cell interaction. Using C3A cells (a hepatocellular carcinoma cell line) as a model, we formed linker-engineered spheroids which grew to a diameter of 250 microm in 7 days, as compared to 16 days using conventional non-adherent culture. Seven-day old linker-engineered spheroids exhibited characteristics of mature MCTS, including spheroid morphology, gene expression profile, cell-cell interaction, extracellular matrix secretion, proliferation and oxygen concentration gradients, and cellular functions. Linker-engineered spheroids also displayed a resistance to drug penetration similar to mature MCTS, with dose-dependent extracellular accumulation of the drug. The linker-engineered spheroids thus provide a reliable accelerated 3D in vitro tumor model for drug penetration studies.