•Dendrite-like gold nanostructures (DGNs) were obtained by a simple potentiostatic method.•The morphology and structure of DGNs could be easily tuned through the deposition conditions.•The DGNs with ...high ESA show superior electrocatalytic activity to glucose oxidation.•DGNs exhibit excellent stability and selectivity for nonenzymatic glucose detection.
Dendrite-like gold nanostructures (DGNs) were directly electrodeposited onto the surface of a glassy carbon electrode (GCE) via the potentiostatic method without any templates, surfactants, or stabilizers. The effects of the deposition time, potential and the concentration of precursor solution on the evolution of the nanostructure and on the electrocatalytic activity of the DGNs were systematically investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical methods including cyclic voltammetry, linear voltammetry and chronoamperometry. The results confirmed that DGNs have good electrocatalytic activity towards the electro-oxidation of glucose in a neutral phosphate buffer solution (PBS, pH 7.4). A non-enzymatic glucose sensor fabricated with the DGNs as an electrocatalyst showed a quick response (less than 2 s), a low detection limit (0.05mM), a wide and valuable linear range (0.1 - 25mM), a high sensitivity (190.7μAcm−2mM−1) and good repeatability and stability. In addition, the commonly interfering species, such as ascorbic acid (AA), uric acid (UA), and 4-acetaminophen (AP), did not cause obvious interference because of the use of a low detection potential (0.15V vs. Ag/AgCl). This work demonstrates a simple and an effective sensing platform for the non-enzymatic detection of glucose.
This work describes controllable preparation of gold nanoparticles on glassy carbon electrodes by using the seed mediated growth method, which contains two steps, namely, nanoseeds attachment and ...nanocrystals growth. The size and the dispersion of gold nanoparticles grown on glassy carbon electrodes could be easily tuned through the growth time based on results of field-emission scanning electron microscopy. Excellent electrochemical catalytic characteristics for glucose oxidation were observed for the gold nanoparticles modified glassy carbon electrodes (AuNPs/GC), resulting from the extended active surface area provided by the dense gold nanoparticles attached. It exhibited a wide linear range from 0.1mM to 25mM with the sensitivity of 87.5 mu Acm-2 mM-1 and low detection limit down to 0.05mM for the sensing of glucose. The common interfering species such as chloride ion, ascorbic acid, uric acid and 4-acetamidophenol were verified having no interference effect on the detection of glucose. It is demonstrated that the seed mediated method is one of the facile approaches for fabricating Au nanoparticles modified substrates, which could work as one kind of promising electrode materials for the glucose nonenzymatic sensing.
In this work, a ratiometric fluorescent probe (RF-probe) for highly sensitive and selective detection of uric acid was reported for the first time toward H2O2 based on inner filter effect (IFE) ...between bimetallic gold/silver nanoclusters (Au/Ag NCs) and 2,3-diaminophenazine (DAP). For this RF-probe, uric acid was degraded to allantoin and H2O2. Upon the addition of HRP, o-phenylenediamine (OPD) could be catalytically oxidized to DAP in the presence of H2O2, then the fluorescence intensity corresponding to DAP at 580 nm increased dramatically with a fluorescence quenching of BSA-Au/Ag NCs at 690 nm, resulting in a RF-probe toward uric acid. This RF-probe allowed for the sensitive detection of uric acid in range of 5.0 × 10−6 M to 5.0 × 10−5 M with a detection limit (S/N = 3) as low as 5.1 × 10−6 M. At the same time, it has been successfully used for uric acid levels detection in human serum, and the results are consistent with those of the hospital. RF-probe built may provide a ratiometric fluorescence universal platform for detection of various species involving in the production of H2O2 in other biological systems.
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•BSA modified Au/Ag NCs were synthesized and used to ratiometric fluorescent probe, which showed good biocompatibility and steady fluorescence property.•A rapid and ultrasensitive ratiometric fluorescent probe was developed for uric acid detection in human blood for the first time.•The fluorescence quenching of BSA-Au/Ag NCs and fluorescence enhancement of DAP were owing to inner filter effect.
A simple, one-step reduction route was employed to synthesize bimetallic Pt-Pd nanoparticles (Pt -PdNPs) supported on graphene (G) sheets, in which the reduction of graphite oxide and metal precursor ...was carried out simultaneously using ascorbic acid as a soft reductant. The morphology and structure of Pt-PdNPs/G composites were characterized using X-ray diffraction, Transmission Electron Microscopy, Field Emission Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy analysis. The results show that Pt-Pd bimetallic nanoparticles were successfully synthesized and evenly anchored on the graphene sheets. Electrochemical experiments, including cyclic voltammetry and chronoamperometric measurements, were performed to investigate the electrochemical and electrocatalytic properties of the Pt-PdNPs/G composites. It was found that Pt-PdNPs/G composites show better electrocatalytic activity and stability towards the electro-oxidation of methanol than its counterparts such as composites composed of graphene-supported monometallic nanoparticles (PtNPs/G, PdNPs/G) and free-standing (Pt-PdNPs) and Vulcan-supported bimetallic Pt-Pd nanoparticles (Pt-PdNPs/V). The results could be attributed to the synergetic effects of the Pt-Pd nanoparticles and the enhanced electron transfer of graphene. The electrocatalytic activity of Pt-PdNPs/G changed with the Pd content in the Pt -Pd alloy, and the best performance was achieved with a Pt-Pd ratio of 1 /3 in an alkaline environment. Our study indicates the potential use of Pt-PdNPs/G as new anode catalyst materials for direct methanol fuel cells.
To optimise spray parameters for fabricating well-bonded and less decarburised coatings, the morphologies and cross-sectional microstructures of powders and splats, in addition to the microstructure, ...phase constitution, and mechanical properties of high-velocity oxy-fuel (HVOF)-sprayed WC–Cr3C2–Co coatings were systematically investigated. Significantly influenced by spray parameters, splat morphologies vary from ellipsoids to well-flattened pies with some ejectors or stripes on their periphery and a splat/substrate interface with good contact. Splat microstructures vary homogeneously from a minimal hard phase to non-uniform structures with some dense surface layers and smoothly outlined hard phases or to non-uniform structures with rough surfaces and angular hard phases. The coating microstructure evolves from a non-lamellar structure with many pores to a lamellar structure with a well-contacted interface and a smooth surface hard phase. The coatings mainly consist of the WC hard phase and a small fraction of decarburised and amorphous phases, in addition to Co, Cr3C2, Cr7C3, Cr2O3, and Cr2O5. Porosity and WC retention index vary from 0.89 ± 0.11 to 2.32 ± 1.75% and from 84.68 to 94.48%, respectively. Microhardness, elastic modulus, fracture toughness, adhesive strength, and wear rate of the coatings vary from 7.03 ± 0.64 to 11.96 ± 0.94 GPa, from 77.64 ± 13.77 to 244.73 ± 65.75 GPa, from 1.23 ± 0.1 to 2.66 ± 0.66 MPa m1/2, from 18.54 ± 1.21 to 63.84 ± 8.01 MPa, and from 1.38 ± 0.32 to 3.54 ± 0.79 × 10−2 mg/(N⋅m), respectively.
•Execute comparison-based dynamic green extension in safety-based smart signal.•Compute projected rear-end collision risks within radar sensor.•Optimal decision rate of 66.7 to 81.3% in reducing ...rear-end risks.•Compatible with delay-minimization-oriented actuated-coordinated signal control.
In view of the dynamic all-red extension (DARE) system’s effectiveness in preventing angled crashes (Park et al., 2018), this study has further enhanced its function to contend with rear-end collisions with dynamic green extension (DGE). With such a function, the enhanced Integrated Intelligent Intersection control system (III-CS) is capable of dynamically terminating the green at the interval of the lowest rear-end collision risk, so as to prevent undesirable “max-out” under actuated signal control which often traps some vehicles in the dilemma zone during high-volume traffic conditions. To ensure its effectiveness in practice, the proposed III-CS has been designed with the following new features: (i) executing the DGE within a customized time window of the green phase to ensure the signal’s effective coordination with its neighboring intersections; (ii) adopting the comparison-based heuristic for the DGE’s real-time risk prediction so as to circumvent the computing and communications delays. The results of two after-deployment assessments show that the system’s DARE has perfectly detected all red-light runners; 66.7 percent of the decisions by the DGE module were observed to achieve the control objective during the first field assessment. The DGE’s performance in making optimal decisions has improved over time and reached the level of 81.3% in the second field evaluation. Other measures of effectiveness, such as the number of vehicles trapped in the dilemma zone and the average deceleration rate of the driving populations approaching the target intersection, have also evolved to the anticipated trend after the deployment.
The high salinity of seawater often strongly affects the activity and stability of photocatalysts utilized for photodriven seawater splitting. The current investigation is focused on the ...photocatalyst H-TiO2/Cu2O, comprised of hydroxyl-enriched hollow mesoporous TiO2 microspheres containing incorporated Cu2O nanoparticles. The design of H-TiO2/Cu2O is based on the hypothesis that the respective hollow and mesoporous structure and hydrophilic surfaces of TiO2 microspheres would stabilize Cu2O nanoparticles in seawater and provide efficient and selective proton adsorption. H-TiO2/Cu2O shows hydrogen production performances of 45.7 mmol/(g·h) in simulated seawater and 17.9 mmol/(g·h) in natural seawater, respectively. An apparent quantum yield (AQY) in hydrogen production of 18.8% in water (and 14.9% in natural seawater) was obtained at 365 nm. Moreover, H-TiO2/Cu2O displays high stability and can maintain more than 90% hydrogen evolution activity in natural seawater for 30 h. A direct mass- and energy- transfer mechanism is proposed to clarify the superior performance of H-TiO2/Cu2O in seawater splitting.
Background
ADH1B rs1229984 and ALDH2 rs671 are the specifically prevalent functional variants in the East Asians. These variants, which result in a dramatic change in enzyme activity, are highly ...associated with alcohol‐related disorders and cancer. Previous studies focusing on the additive and synergic effects of the variants are few and inconsistent. The aim of the research was to evaluate the associations of ADH1B rs1229984 and ALDH2 rs671 with the risks of alcohol‐related disorder and cancer.
Methods
This cohort study enrolled 42,665 participants from the Taiwan Precision Medicine Initiative database, including 19,522 and 20,534, ADH1B and ALDH2 carriers, respectively. The associations between the two variants and cancer risk were analyzed by univariable and multivariable logistic regression.
Results
Compared with the noncarriers, the ADH1B rs1229984 variant had a stronger effect on alcohol‐related disorders and was related to an increased risk of alcohol‐related cancers. The CC genotype of ADH1B rs1229984 was significantly associated with cancer of the larynx, pharynx, and nasal cavities odds ratio (OR) = 1.56, p = 0.0009, cancer of the pancreas (OR = 1.66, p = 0.018), and cancer of the esophagus (OR = 4.10, p < 0.001). Participants who carried the rs1229984 TC/CC and rs671 GG genotypes were at higher risk of esophageal cancer (OR = 3.02, p < 0.001). The risk of esophageal cancer was increased by 381% (OR = 4.81, p < 0.001) in those carrying the rs1229984 TC/CC and rs671 GA/AA genotypes.
Conclusion
rs1229984 and rs671 are common and functionally important genetic variants in the Taiwanese population. Our findings provide strong evidence of additive and synergic risks of ADH1B and ALDH2 variants for alcohol‐related disorders and cancer. The results suggested that are reduction in alcohol consumption should be advised as a preventive measure for high‐risk patients carrying ADH1B rs1229984 C or the ALDH2 rs671 A allele.
Figure. The Flow char for selection of the study population (A), and the PheWAS Manhattan and QQ plots for ADH1B rs1229984 (B) and ALDH2 rs671 (C), respectively Brief Summary Our findings provide evidence of additive and synergic risks of the ADH1B and ALDH2 variants for alcohol‐related disorder and cancer. These results suggested that reduction of alcohol consumption should be advised as a preventive measure for high‐risk patients carrying the ADH1B rs1229984 C or the ALDH2 rs671 A allele.
This paper presents an arterial signal optimization model that features its effectiveness on: (1) explicitly modeling physical queue evolution on arterial links by lane-group to account for ...shared-lane traffic interactions; and (2) capturing the dynamic interactions of spillback queues among lane groups and between neighboring intersections due to high demand, geometric constraints, or signal settings. Depending on the detected traffic patterns, one can select the control objective to be either minimizing the total travel time or maximizing the total throughput over the target area. The solution procedures developed with the Genetic Algorithm (GA) have been tested with an example arterial of four intersections under different demand scenarios. Extensive experimental analyses in comparison with results from TRANSYT-7F (version 8) reveal that the proposed model and solution method are quite promising for use in design of arterial signals, especially under congested, high demand traffic conditions.
The oscillator of the circadian clock of cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, which together generate a self-sustained ∼24-h rhythm of phosphorylation of KaiC. The ...mechanism propelling this oscillator has remained elusive, however. We show that stacking interactions between the CI and CII rings of KaiC drive the transition from the phosphorylation-specific KaiC–KaiA interaction to the dephosphorylation-specific KaiC–KaiB interaction. We have identified the KaiB-binding site, which is on the CI domain. This site is hidden when CI domains are associated as a hexameric ring. However, stacking of the CI and CII rings exposes the KaiB-binding site. Because the clock output protein SasA also binds to CI and competes with KaiB for binding, ring stacking likely regulates clock output. We demonstrate that ADP can expose the KaiB-binding site in the absence of ring stacking, providing an explanation for how it can reset the clock.
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