A silver catalyst with a high-energy surface prepared by plasma spraying for the hydrogen evolution reaction

A self-supported silver electrode was prepared by plasma spraying and used for catalysing the hydrogen evolution reaction. Thanks to the non-equilibrium synthetic conditions, the silver catalyst exposes high-energy (200) crystal planes, which enhance the adsorption of hydrogen and improve the intrinsic catalytic activity. As a result, the silver catalyst delivers an overpotential of 349 mV at 10 mA cm^-2, which was much lower than those of Ag foil (742 mV) and commercial Ag powder (657 mV). This work provides a new idea of preparing active electrocatalysts by traditional processes.

KCNQ1 opposite strand/antisense transcript 1 promotes aggressive biological behaviors of cervical cancer cells via regulating microRNA-491-5p and pyruvate kinase M1/2

Long non-coding RNA (lncRNA) KCNQ1 and opposite strand/antisense transcript 1 (KCNQ1OT1) have been validated to be carcinogenic in several cancers. However, the role of KCNQ1OT1 in regulating the malignant biological behavior and radiotherapy resistance of cervical cancer (CC) remains largely unknown. Quantitative real time-polymerase chain reaction (qRT-PCR) was carried out to detect KCNQ1OT1 and miR-491-5p expression in CC tissues and cells. Pyruvate kinase M1/2 (PKM2) expression was detected by Western blot. CC cell proliferation, movement, migration and invasion were monitored by CCK-8, scratch healing and Transwell assay, respectively. The CC cell colony survival was detected by colony formation assay under different doses of radiation. Dual luciferase reporter gene assay, pull-down assay and RIP assay were employed to verify the targeting relationship between KCNQ1OT1, miR-491-5p and PKM2. In this study, KCNQ1OT1 was significantly up-regulated in CC patient cancerous tissues and cell lines, and its high expression was significantly related to tumor volume increase and poor differentiation. KCNQ1OT1 overexpression significantly promoted CC cell proliferation, metastasis and radioresistance. On the contrary, KCNQ1OT1 knockdown compared to the control group inhibited the above biological behavior of CC cells. The underlying mechanism suggested that KCNQ1OT1 promoted progression and radioresistance of CC by modulating the miR-491-5p/PKM2 axis. In conclusion, KCNQ1OT1 enhances CC cell progression through the miR-491-5p/PKM2 axis.

Microstructure and Mechanical Properties of an Ultrasonic Spot-Welded Aluminum-to-Aluminum Joint: Response to Interlayer Thickness

To enhance the mechanical strength of an ultrasonic spot-welded Al/Al joint, an Al 2219 particle interlayer was placed between the two Al sheets during the ultrasonic spot welding process. The effects of the interlayer thickness on the microstructure and mechanical performances of the joints were systematically investigated. The results showed that, the optimum thickness of the Al 2219 particle interlayer was 10 μm, which was beneficial to enhance the weld interface temperature up to 402 °C. The bonding interface of Al/Al 2219 with a wave-like shape was sound, and no significant diffusion layer occurred. The peak lap shear tensile strength (~84.8 MPa) was obtained, which was 36% higher than that (~67.3 MPa) for the joint without the Al 2219 particle interlayer. The strengthening mechanism is caused by the increase of plastic deformation and contact areas in the weld interface.

Reduction in excess sludge production by addition of chemical uncouplers in activated sludge batch cultures

AIMS

To investigate the possibility of reducing excess sludge production in activated sludge processes by the addition of chemical uncouplers to greatly dissociate anabolism from catabolism.

METHODS AND RESULTS

Ortho-chlorophenol (oCP), 2,4-dichlorophenol (DCP), 3,3',4',5-tetrachlorosalicylanilide (TCS), para-dinitrophenol (pNP) and 2,4-dinitrophenol (DNP) were chosen for short-term tests for their ability to reduce sludge yield by shaking bottle test. The most effective chemicals, DNP and pNP, together with TCS were tested for various uncoupler concentrations and biomass concentrations. TCS was tested in a lab-scale completely mixed activated sludge batch culture. The model (demonstrated by Liu) was verified with experimental data in completely mixed activated sludge batch test, but was inconsistent with the results from the shaking bottle batch test. The observed growth yield (Yobs) decreased with increasing of the ratio of initial uncoupler concentration to initial biomass concentration (Cu/X0).

CONCLUSIONS

We suggest that the uncouplers oCP, DCP, TCS, pNP and DNP can cause a significant decrease in sludge production, the metabolism of which can explain the decline in sludge yield.

SIGNIFICANCE AND IMPACT OF THE STUDY

The real strength of chemical uncoupler imposing on biomass should be Cu/X0, not initial uncoupler concentration (Cu) alone. Chemical uncouplers can be used to develop the activated sludge processes for minimizing excess sludge production.