In situ monitoring of hydrogen peroxide (H2O2) during its production process is needed. Here, an electrochemical H2O2 sensor with a wide linear current response range (concentration: 5 × 10−8 to 5 × 10−2 m), a low detection limit (32.4 × 10−9 m), and a high sensitivity (568.47 µA mm−1 cm−2) is developed. The electrocatalyst of the sensor consists of cobalt nanoparticles and atomic Co‐Nx moieties anchored on nitrogen doped carbon nanotube arrays (Co‐N/CNT), which is obtained through the pyrolysis of the sandwich‐like urea@ZIF‐67 complex. More cobalt nanoparticles and atomic Co‐Nx as active sites are exposed during pyrolysis, contributing to higher electrocatalytic activity. Moreover, a portable screen‐printed electrode sensor is constructed and demonstrated for rapidly detecting (cost ≈40 s) H2O2 produced in microbial fuel cells with only 50 µL solution. Both the synthesis strategy and sensor design can be applied to other energy and environmental fields.

BackgroundChanges of miRNAs in exosome have been reported in different disease diagnosis and provided as potential biomarkers. In this study, we compared microRNA profile in exosomes in 5 MHFMD and 5 ESHFMD as well as in 5 healthy children.MethodsDifferent expression of miRNAs in exosomes across all the three groups were screened using miRNA microarray method. Further validated test was conducted through quantitative real-time PCR assays with 54 exosome samples (18 ESHFMD, 18 MHFMD, and 18 healthy control). The judgment accuracy was then estimated by the receiver operating characteristic (ROC) curve analysis; and the specificity and sensitivity were evaluated by the multiple logistic regression analysis.ResultsThere were 11 different miRNAs in exosomes of MHFMD and ESHFMD compared to healthy children, of which 4 were up-regulated and 7 were down-regulated. Further validation indicated that the 4 significant differentially expressed candidate miRNAs (miR-671-5p, miR-16-5p, miR-150-3p, and miR-4281) in exosome showed the same changes as in the microarray analysis, and the expression level of three miRNAs (miR-671-5p, miR-16-5p, and miR-150-3p) were significantly different between MHFMD or ESHFMD and the healthy controls. The accuracy of the test results were high with the under curve (AUC) value range from 0.79 to 1.00. They also provided a specificity of 72%-100% and a sensitivity of 78%-100%, which possessed ability to discriminate ESHFMD from MHFMD with the AUC value of 0.76-0.82.ConclusionsThis study indicated that the exosomal miRNA from patients with different condition of HFMD express unique miRNA profiles. Exosomal miRNA expression profiles may provide supplemental biomarkers for diagnosing and subtyping HFMD infections.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2334-14-506) contains supplementary material, which is available to authorized users.

Metal-resistant endophytic fungi from roots improved phytoremediation efficacy of host plants; however, the effects of endophytic fungi from plant aerial parts on host plants are unknown. The aim of this study was to develop a feasible method to screen fungal endophytes from stems and roots of Brassica napus and to investigate effects of the endophytic fungi on growth and phytoremediation efficiency of the plant. Endophytic Fusarium sp. CBRF44, Penicillium sp. CBRF65, and Alternaria sp. CBSF68 with different traits were isolated from roots and stems of rapes grown in a metal-contaminated soil. Fusarium sp. CBRF44 (resistant to 5 mM Cd and 15 mM Pb, isolated from roots) and Alternaria sp. CBSF68 (resistant to 1 mM Cd and 10 mM Pb, isolated from stems) could produce indole-3-acetic acid (IAA) and siderophore; Penicillium sp. CBRF65 (tolerate 2 mM Cd and 20 mM Pb, isolated from roots) could not produce IAA and siderophore but showed the highest phosphate-solubilizing activities. Fusarium sp. CBRF44 and Penicillium sp. CBRF65 significantly increased the rape biomass and promoted the extraction efficacy of Pb and Cd, while Alternaria sp. CBSF68 did not show similar results. Penicillium sp. CBRF65 and Fusarium sp. CBRF44 could be frequently recovered from inoculated rape roots, while Alternaria sp. CBSF68 was scarcely recovered. The results indicate that the colonizing capacity of endophytic fungi in roots is important to improve phytoremediation efficacy of host plants.

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The energy density of batteries with lithium cobalt oxide (LCO) can be maximized by increasing the cut-off voltage to approach the theoretical capacity limit. However, it is not realized in the practical applications due to the restricted cycle life caused by vulnerable cathode surface in deep delithiation state, where severe side reactions, oxygen/cobalt loss and structure degradation often happen. Here, an outside-in oriented nanostructure on LiCoO 2 crystals is fabricated. The outer electrochemically stable LiF and Li 2 CoTi 3 O 8 particles perform as physical barrier to prevent damage of both cathodes and electrolytes, while the inner F doping promote Li ions diffusivity and stabilize the lattice oxygen. With the spinel-like transition layer between them, a solid and complete lithium-ion transport channel generation along the lithium concentration gradient. Under the protection from this structure, the LiCoO 2 withstand the high voltage of 4.6 V and the LCO/graphite pouch full cell with high loading density exhibits 81.52% energy density retention after 135 cycles at 4.5 V.

A Cu/Mn immobilized carbon nanoframework modified sensor was used for continuously detecting the H2O2 concentration in an electro-Fenton system.

The demanding for high energy density as well as high safety is still an important threshold for battery commercialization. Next‐generation layered LiNixCoyMn1−x−yO2 (NCM) cathodes will meet the specific energy required for driving range of at least 300 miles from a single charge to guarantee the success of electric vehicles. Extending operating voltage of NCM cathode materials is considered as an effective way to increase energy density of lithium ion batteries. However, unstable electrode electrolyte interface (CEI) limits the electrochemical performance of NCM cathodes when operating at high voltages (>4.3 V). In this review, underlying factors and mechanisms that result in the failure to form a robust CEI are analyzed, including surface phase reconstruction, stress‐induced cracking, transition metal dissolution, electrolyte decomposition and oxygen redox reaction. Then, progress on how to improve and stabilize CEI is summarized. To bridge the gap between current and next generation automotive batteries, it is expected that the situation of NCM electrode materials at high voltage to be fine‐tuned with available variables such as nickel content, packaging density and loading level. Moreover, more detailed work on designing and studying a reliable CEI can help the application of NCM cathodes under high voltage.

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