Search

In order to get the state of particles and the reaction process in the electrolyte during electrodeposition clearly, the lotus leaf-like superhydrophobic film is prepared on the surface of aluminum alloy by electrodeposition, in which the contact angle reach 159.3∘. According to contact angle and scanning electron microscope results, the crystal water in the electrolyte system plays an important role in the deposition process. The existence of crystal water can promote the ionization of Ce[Formula: see text] and form the carrier system effectively. The composition of the film is cerium stearate, which shows multilayer growth. The electrochemical impedance spectra results show good corrosion resistance and application value.

Purpose The purpose of this paper is to prepare composite micro-arc oxide coatings with better wear resistance and corrosion resistance. Design/methodology/approach A nickel powder composite micro-arc oxide film was prepared on the surface of the magnesium alloy by the method of organically combining ultra-fine Ni powder with micro arc oxidation film layer. In this experiment, the changes in the corrosion resistance and microstructure of the composite film layer after adding Ni powder were studied, and the effect of the addition of glycerin on the corrosion resistance of the film layer was analyzed. Findings The results show that the ultra-fine nickel powder was successfully prepared by the liquid phase reduction method, and the micro-arc oxidation process was modified under the optimal addition amount. The surface of the micro-arc oxide film made of ultra-fine nickel powder was found by SEM to have smooth surfaces and few holes. According to X-ray diffraction analysis, the phase composition of the micro-arc oxide film layer was Mg, Ni, NiSiO4, MgNi (SiO4) and Mg2SiO4. According to the results of electrochemical tests, the corrosion resistance of the micro-arc oxidation composite film layer was improved after the addition of ultra-fine Ni powder, the corrosion current was greatly reduced and the impedance has been improved. And after adding glycerin, the surface of the film layer becomes denser, and the corrosion resistance of the micro-arc oxide film is significantly improved. Originality/value Through this experimental research, a micro-arc oxide coating of powder composite magnesium alloy was successfully prepared. The corrosion resistance of the micro-arc oxidation film layer has been improved, and certain functions had been given to the micro-arc oxidation composite film, which has increased the application field of magnesium alloys.

V and F ions co-doped LiFePO4/C (LFP-VF) cathode material is prepared via high-temperature ball milling route. Effects of V and F ions co-doped on the structure, morphology and electrochemical property of LiFePO4 are investigated in this work, and some analysis of X-ray diffraction, scanning electron microscope, transmission electron microscope, charge-discharge tests, electrochemical impedance spectroscopy and cyclic voltammetry are employed. The results confirm that prepared LFP-VF exhibits excellent electrochemical property. The specific capacities are 165.7 (0.1 C), 154.9 (1.0 C) and 124.9 (10 C) mAhg−1. Moreover, over 500 cycles at 1.0 C-rate, the discharge capacity is 148.2 mAhg−1 with a capacity retention rate of 95.7%. Experimental results indicate that the electrochemical performance of LiFePO4 can be greatly enhanced by co-doping with V and F ions.

LiFePO4/C cathode material was prepared via high-temperature ball-milling route with ultrasonic dispersion as mixing process using eutectic molten salt (0.76 LiOH·H2O-0.24 Li2CO3) as lithium source. Box-Behnken design was used to study the combined effects of ultrasonic time, ball-milling temperature, and ball-milling time on the discharge capacity to obtain the optimum predicted conditions. The optimum conditions were as follows: ultrasonic time was 63 min, ball-milling temperature was 638 °C, and ball-milling time was 7 h. LiFePO4/C prepared from the optimized experimental conditions exhibited a well electrochemical performance; its discharge capacity was 161.3 mAh g−1 at a 0.1 C-rate which was in consistence with the predicted discharge capacity of 160.2 mAh g−1. Moreover, its capacity retention rate achieved 93.6% at a 10 C-rate over 100 cycles.

This paper briefly describes the preparation of LiNi0.5Mn1.5O4 by ultrasonic chemistry and its doping modification. The physical and electrochemical properties of LiNi0.5Mn1.5O4 were studied by SEM and electrochemical tests. The results show that the particles doped with graphene had smaller particle size and uniform distribution. The initial discharge specific capacity of 0.1C was 187 mAh g−1. The discharge specific capacity after 30 cycles was 181 mAh g−1, and the capacity retention rate was 97%. Graphene-doped samples had high capacity, excellent rate performance, and significant cycle stability.

Virtual molecular docking is a computational method used in computer-aided drug discovery that calculates the binding affinity of a small molecule drug candidate to a target protein and greatly reduces the time and cost of suggesting new potential pharmaceuticals. D3DOCK is a suite of automated docking tools, it was developed for sensitively investigating the effects of halogen bond in drug discovery by based on Autodock Vina. In this study, we developed IDOS, a high-throughput and scalable virtual docking system. We use the open source Hadoop framework implementing the Spark paradigm for distributed computing on a private cloud platform. IDOS can work on a single node as well as on distributed nodes compared with the stand-alone version of D3DOCK, it performed almost linear acceleration on our Spark cluster, with parallel efficiency of more than 80%, and 5x to 6x speedup can be achieved on the cluster depending on the number of work nodes. Moreover, On account of the widely used of cloud computing, IDOS can be easily installed and employed for docking on condition that the IDOS docker image was upload to the docker hub shared warehouse. We also have developed the docking workflow with an MPI version on high-performance computers (HPC). However, compared with HPC system, mounting IDOS on a cheap and easy to obtain cloud computing cluster is obviously more conducive, which allows more researchers to do docking with it expediently. IDOS is freely available at https://github.com/codedinner/IDOS.

In order to improve the throughput and plasticizing capability of traditional single screw extruder (SSE), grooves at the inner surface of barrel were extended from the feeding zone to the melting zone of the extruder. However, the melting behavior and plasticizing quality of polymers in the grooved SSE can not be observed and measured intuitively because of the closed structure of the extruder. In this study, four types of detection techniques, including visualization technology, ultrasound testing, melt pressure on-line detecting and mechanical properties analysis, were developed to characterize the plasticizing capability of SSE with grooved melting zone. Four screws with different compression ratios were also utilized to investigate the plasticizing performance of SSE with grooved melting zone. The procedure conditions, such as barrel temperature and screw speed, were also analyzed. The experimental results showed that cooperating with an anti-compression ratio screw, SSE with grooved melting zone had a reasonable melt pressure, improved throughput and great plasticizing performance, which was very promising in the polymer processing industry.

A method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation was developed for the simultaneous determination of 12 perfluorocarboxylic acids (PFCAs) and 7 perfluorosulfonic acids (PFSAs) in the muscle of shrimp, shellfish, and fish. A modified QuEChERS procedure was applied to the extraction and concentration of perfluorinated compounds (PFCs) as well as for removal of interferences. The determination of the 19 PFCs was performed by LC-MS/MS in negative-ion detection mode. 13C-labeled PFCs, as a stable isotopic internal standard (except for L-PFBS, L-PFPeS, ipPFNS, and L-PFNS, for which no labeled analogs were available), was used for calibration. The limits of detection ranged from 0.01–1.0 μg/kg. The recoveries of spiked sample at 0.02–8.0 μg/kg ranged from 61 to 117% with relative standard deviations of less than 14%. The developed method was successfully utilized to monitor real samples, which demonstrated that it is a simple, fast, and robust method and could be used to monitor PFCAs and PFSAs in aquatic products. Most of the samples tested positive, mainly for perfluorooctane sulfonate acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorobutanoic acid (PFBA), but other samples of the 14 studied PFCs were also present.

A novel 3D printing strategy for continuous glass fiber reinforced polylactic acid (CGF/PLA) composites was proposed. CGF/PLA filament was prepared by a melting impregnation device, and then CGF/PLA filament was directly supplied to the self-modified 3D printing device. The impregnation process was optimized systematically, and the fiber content reached up to 45 wt%. A specific compatibilizer was used and the amount of compatibilizer was optimized to enhance the interfacial bonding between fiber and polymer. The effects of printing parameters such as nozzle diameter, edge width, layer thickness, printing speed and temperature on the mechanical properties and microstructure of the final printed products were studied. The flexural strength and flexural modulus of the printed products reached 312 MPa and 21.5 GPa, respectively. The fabrication strategies proposed in this study can provide a low-cost and high-strength method for the industrial application of 3D printed continuous fiber reinforced thermoplastic composites.

BACKGROUND Recently, some studies were performed to evaluate the relevance of B7-H4 and gastric cancer (GC) prognosis. However, the results remained controversial. Therefore, we performed the present meta-analysis. MATERIAL AND METHODS We performed a systematic search in PubMed and Web of Science databases. All data were extracted and reviewed from each eligible study independently by 2 investigators. The strength of association between B7-H4 and GC prognosis was assessed by computing odds ratio (OR) with its corresponding 95% confidence interval (CI). RESULTS Six studies that evaluated the association between B7-H4 and GC prognosis were included. The results showed a statistically significant association of B7-H4 and GC prognosis (OR=1.63, 95%CI=1.30-2.03). Furthermore, we conducted subgroup analysis based on source of B7-H4; the results from blood (OR=1.71; 95%CI, 1.09-2.68) and tissue (OR=1.60; 95%CI, 1.03-2.07) indicated B7-H4 was significantly associated with poor prognosis. CONCLUSIONS This meta-analysis suggests that GC patients with high B7-H4 have poor prognosis.

The tissue distribution and bioaccumulation of 8:2 fluorotelomer alcohol (8:2 FTOH) were evaluated in pigs after oral exposure of a dose of 5 mg/kg.b.w.d. for 7 d. The bioaccumulation of 8:2 FTOH and its metabolites showed significant differences among the various tissues. The parent compound was quickly depleted, and the main metabolites perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), and 3-perfluoroheptyl propanoic acid (7:3 FTCA) were detected in all tissues examined. The relative elimination half-life (T1/2re) calculated by compound concentration of 7:3 FTCA and PFOA was longest in kidney tissue (8.60 and 23.9 d, respectively), while their absolute elimination half-life (T1/2ab) of 7:3 FTCA and PFOA calculated by compound amount was longest in kidney tissue (10.41 and 64.1 d, respectively). The T1/2re and T1/2ab for PFHpA was longest in heart tissue (19.3 d and 30.26 d, respectively).The accumulated PFOA in kidney and liver tissues was still above the detection limit (LOD) at 21 d postdosing. These results indicate that PFOA and the kidneys are the ideal biomonitoring marker and target tissue, respectively, for 8:2 FTOH pollution. The T1/2 values of the main metabolites were of long duration compared to the growth cycle of farmed pigs (approximately 180 d) before slaughter; therefore, pigs contaminated with 8:2 FTOH present a potential risk to humans.

Nanofibers or nanofibrous membranes prepared by electrospinning possess many attractive properties, including excellent mechanical properties, high specific surface area and high porosity, making them attractive for sensor application, especially for the electrochemical sensors. Many nanomaterials are used as additives to improve the conductivity, sensitivity and selectivity of sensors. Based on the different modifiers of electrode materials, electrochemical sensors can be divided into enzyme sensors and non-enzyme sensors. In this review, we summarize the recent progress of the electrochemical sensors fabricated by electrospinning, including hydrogen peroxide (H2O2) sensors, glucose sensors and other sensors. In addition, the sensing mechanisms of various electrochemical sensors are introduced in detail. Finally, future research directions of electrochemical sensors based on electrospinning and the challenges faced by large-scale applications of electrospun electrochemical sensors are presented.

A simple multiresidue method was developed for detecting and quantifying 92 veterinary antimicrobial drugs from eight classes (β-lactams, quinolones, sulfonamides, tetracyclines, lincomycins, macrolides, chloramphenicols, and pleuromutilin) in livestock excreta and water by liquid chromatography with tandem mass spectrometry. The feces samples were extracted by ultrasound-assisted extraction with a mixture of acetonitrile/water (80:20, v/v) and edetate disodium, followed by a cleanup using solid-phase extraction with an amino cartridge. Water samples were purified with hydrophilic-lipophilic balance solid-phase extraction column. Urine samples were extracted with acetonitrile and edetate disodium. Detection of veterinary antimicrobial drugs was achieved by liquid chromatography with tandem mass spectrometry using both positive and negative electrospray ionization mode. The recovery values of veterinary antimicrobial drugs in feces, urine, and water samples were 75-99, 85-110, and 85-101% and associated relative standard deviations were less than 15, 10, and 8%, respectively. The limits of quantification in feces, urine, and water samples were 0.5-1, 0.5-1, and 0.01-0.05 μg/L, respectively. This method was applied to determine real samples obtained from local farms and provides reliable quantification and identification results of 92 veterinary antimicrobial drugs in livestock excreta and water.

The xLi[Li[Formula: see text]Mn[Formula: see text]]O[Formula: see text](1−x)Li[Ni[Formula: see text]Mn[Formula: see text]Co[Formula: see text]]O2 was prepared by coprecipitation method in this paper. Co(NO3)2, NiCO[Formula: see text]Ni(OH)[Formula: see text]H2O, LiOH⋅H2O and MnSO[Formula: see text]H2O were used as the sources of cobalt, nickel, lithium and manganese. In the process of calcining and sintering, the temperature and time of the material were studied. The optimum conditions for the coprecipitation method synthesis were determined: precursor was pre-sintered at 500[Formula: see text]C for 5 h, then the precursor was successively sintered at 850[Formula: see text]C for 9 h to get the final product. The results of XRD and SEM showed that the composite particles and crystal structure of the particles exhibited basic integrity and high degree of crystallinity with [Formula: see text]-NaFeO2-type structure. The first charging and discharging capacities were 183.14 mA[Formula: see text]⋅[Formula: see text]h[Formula: see text]⋅[Formula: see text]g[Formula: see text] and 171.11 mA[Formula: see text]⋅[Formula: see text]h[Formula: see text]⋅[Formula: see text]g[Formula: see text] at 0.1 C with a discharge efficiency of 93%. The capacity retention rate was 95% over 20 cycles. It had a good electrochemical cycling performance.

The effect of different metal ions on the photocatalytic property of TiO2 film prepared by micro-arc oxidation was studied. Photocatalytic experiments showed that the impregnation of metal ions increased the photocatalytic efficiency of TiO2. The increase of transition element Fe[Formula: see text] and the rare earth element Dy[Formula: see text] is more obvious, and the optimum concentration is 0.1[Formula: see text]mol/L. The SEM results showed that there was no significant change on the surface of TiO2 film before and after metal ion immersion. The results of EDS surface scanning showed that Fe and Dy elements were uniformly distributed on the surface of TiO2 film after metal ion impregnation, and the deposition amounts were 0.81% and 3.39%, respectively. XRD results showed that a new phase was formed in Fe[Formula: see text]-impregnated TiO2, which could improve the photocatalytic efficiency.

A simple multiresidue method was developed for detecting and quantifying 92 veterinary antimicrobial drugs from eight classes (β-lactams, quinolones, sulfonamides, tetracyclines, lincomycins, macrolides, chloramphenicols, and pleuromutilin) in livestock excreta and water by liquid chromatography with tandem mass spectrometry. The feces samples were extracted by ultrasound-assisted extraction with a mixture of acetonitrile/water (80:20, v/v) and edetate disodium, followed by a cleanup using solid-phase extraction with an amino cartridge. Water samples were purified with hydrophilic-lipophilic balance solid-phase extraction column. Urine samples were extracted with acetonitrile and edetate disodium. Detection of veterinary antimicrobial drugs was achieved by liquid chromatography with tandem mass spectrometry using both positive and negative electrospray ionization mode. The recovery values of veterinary antimicrobial drugs in feces, urine, and water samples were 75-99, 85-110, and 85-101% and associated relative standard deviations were less than 15, 10, and 8%, respectively. The limits of quantification in feces, urine, and water samples were 0.5-1, 0.5-1, and 0.01-0.05 μg/L, respectively. This method was applied to determine real samples obtained from local farms and provides reliable quantification and identification results of 92 veterinary antimicrobial drugs in livestock excreta and water.