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Large micron-sized Y 3 Al 5 O 12 :Ce3+ phosphors were successfully synthesized by a cost-effective method using eutectic mixtures of YF 3 –AlF 3 as the molten-salt flux for high-power laser diodes applications. The crystallinity, morphology, particle size, thermal quenching properties of the phosphors were measured, respectively. The phosphor particle size increased with increasing amount of flux, and the medium size (D 50) could reach 40 μm when adding 25 wt% YF 3 –AlF 3. The phosphors with larger particle size did not only exhibit superior optical performances but also excellent thermal-quenching characteristics, leading to a lower surface temperature and a higher radiant efficiency when excited by a high-power laser. [ABSTRACT FROM AUTHOR]

A novel buoyant force-propelled micromotor is designed by decorating bimetallic catalysts (Ag and Pt NPs) on glassy carbon bead matrix for high efficient removal of organic pollutant via advanced oxidation processes. The micromotor floats to the top of solution when enough number of bubbles are accumulated on its surface and then sinks to the bottom after the evolution of bubbles. Owing to the excellent catalytic effect of Ag and Pt NPs, oxygen bubble generation and evolution frequencies are improved, leading to the ultra-fast movement of micromotor in H 2 O 2 solution with a long lifetime of 6 h and a highest speed of ca. 12 mm/s. Meanwhile, active radical species are produced in the reaction of Ag NPs and H 2 O 2. As a result, the synergy effect of vigorous intermixing and peroxidase mimics activity of Ag NPs speeds up the degradation significantly. In order to improve the decontamination efficiency, key factors that affect the motion performance and the generation of ROS, including H 2 O 2 , sodium dodecyl sulfate, buffer solution and the amount of micromotors, are discussed using response surface methodology. Taking methylene blue (MB) as pollutant model, the degradation rate increased from 32.47% to 90.42% after the deposition of Pt NPs on Ag micromotor, indicating the excellent catalytic effect of the bimetallic catalysts modified micromotor. Possible degradation pathway of MB was proposed, based on the results of quantum chemistry calculation and LC/MS analysis. Overall, the ultra-high traveling speed and the excellent catalytic effect make it to be a promise candidate for environmental remediation. [Display omitted] • An ultra-fast bifunctional micromotor is designed which can float and sink autonomously for 6 h. • Synergy effect of vigorous intermixing and peroxidase mimics activity of micromotor speeds up the degradation. • O 2 •, 1O 2 , and •OH are responsible for the degradation of MB and O 2 • is the main oxidant. • A possible degradation pathway of MB is proposed. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation with boron-doped diamond (BDD) had been well established as an outstanding technology for wastewater treatment. In this study, BDD technology was initially used to degrade direct blue 71 (DB71) dye under galvanostatic conditions. The main and joint effects of three operating parameters (supporting electrolyte concentration, applied current density and flow rate) on oxidation performance were estimated by Box-Behnken design. Among the variables, sulfate concentration displayed the most unique roles in DB71 degradation. The optimum operating conditions obtained by response surface methodology were: 2.0 mM Na 2 SO 4 , applied current density of 7.75 mM cm−2 and flow rate of 600 mL min−1, which gave a decolorization percentage of 100%, a mineralization percentage of 50.2%, as well as an energy consumption of 3845 kWh kg−1 TOC and a mineralization efficiency of 8.7% at 120 min of electrolysis. In addition, based on the quantum chemistry calculation and identified reaction intermediates detected by LC/MS analysis, a plausible degradation sequence of DB71 in BDD anode cells was also proposed. The results obtained were expected to offer useful guidance for the application of BDD technology as powerful and green option for treating DB71 pollutants. [Display omitted] • Direct blue 71 could be effectively oxidized with boron-doped diamond. • The electrolytic degradation of DB71 was optimized by Box-Behnken design. • Sulfate electrolytes displayed significant and unique roles in DB71 degradation. • DFT, FOA and LC/MS analyses were all employed for mechanistic study. • A detailed oxidation pathway of DB71 on BDD anodes was proposed and discussed. [ABSTRACT FROM AUTHOR]

• Novel BPE-ECL biosensor based on DNA network was developed for S. aureus assay. • Synergic amplification effect based on target-triggered PCR and pMB NPs was used. • Three-dimensional Au-DNA network allows for the loading of plenty pMB NPs. • The electrochemical reduction of pMB NPs could greatly amplify the ECL intensity. A novel bipolar electrode (BPE)-electrochemiluminescence (ECL) device was constructed for the ultra-sensitive detection of Staphylococcus aureus (S. aureus) by combining polymerase chain reaction (PCR) amplification and DNA network-loaded polymethylene blue nanoparticles (pMB NPs). The presence of target triggered the dissociation of double-stranded DNA on Fe 3 O 4 NPs and the release of T strand, which initiated the PCR. The PCR product contains two protruding single-stranded DNA fragments that serve as bridges to connect Au NPs labeled probes. The PCR-Au products were captured by the probes on cathode of BPE to form three-dimensional DNA networks, which offer multiple adsorption sites for pMB NPs, leading to the remarkable enhancement of ECL intensity. Under optimal circumstances, a wide linear range from 10 to 108 CFU/mL and a low detection limit of 0.78 CFU/mL were achieved. This research opens new horizons for the application of PCR-based biosensors for the accurate and sensitive measurement of pathogenic bacteria. [ABSTRACT FROM AUTHOR]

• An electrochemical sensor was designed for S. aureus detection. • Dumbbell hybridization chain reaction (DHCR) enhanced pMB NPs on electrode surface. • Nanoscale pMB NPs effectively enhanced the electrochemical responses. • The sensor was highly sensitive, specific and accurate in practical application. Pathogenic bacteria infections pose a major threat to human health which can be found in contaminated food and infected humans. Herein, an electrochemical sensor was developed for pathogenic bacteria assay using a dual amplification strategy of polymethylene blue nanoparticles (pMB NPs) and dumbbell hybridization chain reaction (DHCR). The strong binding ability of aptamer to targets endowed outstanding performance in identifying Staphylococcus aureus (S. aureus) among other typical bacteria. The released T strands were hybridized with capture DNA on electrode surface which triggered DHCR in the presence of two dumbbell-shaped helper DNA, leading to the formation of extended and tight dsDNA polymers. In combination with pMB NPs (redox indicators), S. aureus was quantitatively detected in a range of 10–108 CFU/mL and the detection limit reached 1 CFU/mL. Moreover, this sensor was successfully applied for S. aureus detection in human serum and foods, demonstrating the reliability in practical applications. [ABSTRACT FROM AUTHOR]

• A dual-mode ratiometric aptasensor was developed for S. aureus detection. • Aptamer-target recognition events activated DNAzyme-assisted cycling process. • "Turn-on" ECL signal and "turn-off" EC signal ensured sensitive detection. • Built-in self-calibration of dual-mode responses enabled reliable measurement. Pathogenic bacteria have a significant impact on food safety. Herein, an innovative dual-mode ratiometric aptasensor was constructed for ultrasensitive and accurate detection of Staphylococcus aureus (S. aureus) based on recycling of DNAzyme activation on gold nanoparticles-functionalized MXene nanomaterials (MXene@Au NPs). Electrochemiluminescent (ECL) emitter-labeled probe DNA (probe 2-Ru) containing the blocked DNAzyme was partly hybridized with aptamer and then captured by electrochemical (EC) indicator-labeled probe DNA (probe 1-MB) on electrode surface. When S. aureus presented, the conformation vibration of probe 2-Ru activated the blocked DNAzymes, leading to recycling cleavage of probe 1-MB and ECL tag close to electrode surface. Based on the reverse change tendencies of ECL and EC signals, aptasensor achieved S. aureus quantification from 5 to 108 CFU/mL. Moreover, the self-calibration characteristic of the aptasensor with dual-mode ratiometric readout ensured the reliable measurement of S. aureus in real samples. This work showed useful insight into sensing foodborne pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Objective Voltage-gated inward Ca 2+ currents (ICa) are triggered by cell depolarization and commonly produce transient increases in the cytoplasmic free Ca 2+ concentration. The Ca V 1.2 distal C-terminus is susceptible to proteolytic cleavage, which yields a truncated Ca V 1.2 subunit and a cleaved C-terminal fragment (CCt or DCT). Stem cells from the apical papilla (SCAPs) has a capacity for differentiation into the odontoblastic-like cells in vitro and dentin forming in vivo, which makes SCAPs advantages in tissue engineering and regenerative endodontic. The aim of this study was to investigate the effect of Ca V 1.2 and its distal C-terminal fragment in the odontoblastic differentiation of rat SCAPs (stem cells from the apical papilla). Design In this study, we generated stable Ca V 1.2 knockdown and DCT over-expressed rSCAPs using short hairpin RNA and DCT gene containing Lentivirus vectors, respectively. The transfected apical papilla cells were induced to differentiate into the odontoblast-like cells, and the expression of markers for odontoblastic differentiation were analyzed by alizarin red staining, Real-time Polymerase chain reaction (RT-PCR), and Western blot analysis. Results The knockdown of Ca V 1.2 and excess expression of DCT both suppressed the expression of DSPP, ALP in mRNA level and the formation of calcium nodules. Conclusions Our results suggest that Ca V 1.2 and DCT play important roles in the differentiation of rSCAPs, DCT might act as a transcription factor and regulate the differentiation of rSCAPs. [ABSTRACT FROM AUTHOR]

Over the past decades, the development of novel catalysts on the degradation of organic pollutants has attracted increasing attention. In this work, we synthesized silver decorated magnetic nanoparticles (Fe 3 O 4 @PDA/Ag NPs) to activate H 2 O 2 for organic pollutants removal via advanced oxidation processes (AOPs). The catalyst was prepared through in-situ reduction of AgNO 3 by the polydopamine (PDA) layer on Fe 3 O 4 NPs. Chemiluminescence results obtained from luminol/H 2 O 2 system revealed that the catalyst exhibited excellent catalytic effect on the decomposition of H 2 O 2 into reactive oxygen species (ROS) and superoxide radical (O 2 ―) was mainly responsible for the oxidative degradation. Importantly, the fast evolution frequency of oxygen gas bubbles produced in the reaction of Ag NPs and H 2 O 2 could generate vigorous fluid convection and autonomous motion of catalyst when H 2 O 2 concentration reached 1%. Additionally, the catalyst can suspend in solution for several minutes. Therefore, by coupling the vigorous motion with slow sedimentation velocity, the catalyst can realize rapid degradation of organic pollutants without external mixing force. The Fe 3 O 4 @PDA/Ag NPs catalysts not only showed a high removal efficiency of malachite green, but also can be applied for the degradation of other dyes, making it to be a promise candidate for environmental remediation. With the merits of excellent catalytic effect, fast degradation speed, and simplicity of operation, the prepared catalysts exhibits great potential in the practical field. [Display omitted] • Fast oxygen bubble evolution frequency improves the mixing efficiency. • The mechanism for organic pollutant removal without agitation was investigated. • Malachite green degradation was studied by response surface methodology. • The catalyst can rapidly mineralize other organic pollutants. [ABSTRACT FROM AUTHOR]