A self-powered triboelectric nanosensor for detecting the corrosion state of magnesium treated by micro-arc oxidation.

Magnesium (Mg) is frequently used as a biocompatible implantable material in the human body, but real-time detection of its corrosion state is not well understood. Fortunately, previous studies of triboelectric nanogenerators (TENG) as self-driven sensors in many fields have proposed solutions for this problem. In this work, Mg-based TENG was prepared as a self-driven sensor to detect the corresponding corrosion state of Mg treated by micro-arc oxidation (MAO-Mg). Mg-based sheets and polydimethylsiloxane (PDMS) film were used as triboelectric materials. The output of TENG was optimal under 350 V-800 Hz micro-arc oxidation (MAO) treatment of Mg, and the V oc, I sc and Q sc were 48.5 V, 35.3 µA and 44.2 nC, which were respectively 2.42, 3.42 and 3.27 times that of the untreated devices. Moreover, a linear relationship was found in simulated body fluid (SBF) immersion tests, showing that the rates of decrease in I sc and V oc were respectively 3.48 and 2.74 times the weight reduction rates of MAO-Mg sheets, indicating that our sensors successfully detected the corrosion of MAO-Mg. This work will lay a preliminary foundation for real-time detection of Mg as an implant in the human body (as do other implantable materials), and demonstrates a potential new application for TENG in the biomedical field.

Short- and long-term outcomes of laparoscopic versus open surgery for rectal cancer: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: The present meta-analysis aimed to evaluate the short- and long-term outcomes of laparoscopic surgery (LS) versus open surgery (OS) for rectal cancer. METHODS: PubMed, Web of Science, and Cochrane Library, were searched for eligible randomized controlled trials (RCTs) published up to June 2017. Operation related index, postoperative complication, and long-term survival rate and disease-free survival rate were evaluated by meta-analytical techniques. RESULT: Nine RCTs enrolling 4126 patients were included in the present meta-analysis. Compared to OS, LS had similar positive circumferential resection margin (CRM) and number of lymph nodes extracted (LNE) as well as long term 5 years survival rate and disease-free survival rate, but of which the risk tendency was higher in LS group. The short-term outcomes of major and total postoperative complication were lower in LS group. CONCLUSIONS: LS for rectal cancer was as safe and effective as OS in terms of long-term outcomes, but with lower postoperative complication.

[Construction of quantitative real-time PCR detection system of transgenic tomato line Zeneca B,Da,F].

OBJECTIVE: To construct the plasmid reference molecules for detection of transgenic tomato line Zeneca B,Da,F using quantitative real-time PCR(qPCR). METHODS: Three plasmid reference molecules pEasy-T3-APX, pEasy-T3-16A and pEasy-T3-16S were cloned based on reverse genetics, which contain the target fragments of tomato endogenous reference gene apx (ERG-apx), gene-specific sequence of pg(GS-pg) and construct-specific sequence of vectors pJR16S/pJR16A (CS-16S/CS-16A) of Zeneca B,Da,F, respectively. Primers and Taqman probes were designed by Beacon Designer 7.5.The specificity, sensitivity, reproducibility and the limit of detection(LOD) of the qualitative and quantitative PCR system based on the plasmid reference molecules were evaluated. PicoGreen was used to measure the DNA concentration of the plasmid reference molecules. Two sets of samples containing 1% or 0.1% (w/w) pEasy-T3-16A or pEasy-T3-16S mixed with pEasy-T3- APX as background DNA were prepared for evaluating the efficacy of the qPCR system. RESULTS: The target fragments for qPCR detection were anchored, ERG-apx 108 bp, GS-pg 108 bp , CS-16S 109 bp and CS-16A 102 bp. The three plasmid reference molecules were confirmed at the expected sizes by restriction enzyme digestion. The qPCR results showed that the RSD of reproducibility were 0.2% to1.5%, LOD was 25 copies, R2 values for these standard curves were 0.994 ~0.998 and amplification efficiencies were 93.3%~102.4%.The bias between the test and true values of two sets of mixed samples ranged from -9.3% to 14.7% after adjusting by conversion factors(Cf). CONCLUSION: The plasmid reference molecules and qPCR system for qualitative and quantitative detection of transgenic tomato line Zeneca B,Da,F have been established successfully.