Abnormal expressions of uracil-DNA glycosylase (UDG) have been associated with various diseases. We proposed a novel electrochemical biosensing platform-based strategy for UDG detection. This method ...combined NiCoP@PtCu nanozyme with multi-MNAzyme junctions. The U base was deleted in the presence of UDG, resulting in self-assembly of multi-MNAzyme junctions with the ability to continually cleave DNA hairpins and release various products. The products could bind the protective probes, exposing capture probes on the electrode’s surface. Moreover, the exposed probes hybridized with the sDNAs-labeled NiCoP@PtCu nanozyme, yielding a significant electrochemical signal. The established biosensor was enzyme-free and with an ultrahigh sensitivity. Benefiting from the twofold amplification of multi-MNAzyme junctions and nanozyme, the sensing technique exhibited a large dynamic range, from 0.001 to 1.0 U mL −1 and a low detection of 6.6 × 10−4 U mL −1. In addition, the method was effectively used for UDG detection in lysed cells. Therefore, the biosensor we established has broad prospects in clinical diagnosis and biomedical research.
•An enzyme-free electrochemical biosensor is developed for sensitive detection of uracil-DNA glycosylase (UDG).•multi-MNAzyme junctions possessed improved shearing efficiency and signal amplification ability.•NiCoP@PtCu nanozyme had large surface area, more active sites, well electrical conductivity, and excellent catalytic activity.•This biosensor shows low limit of detection and wide linear range of UDG activity.
A computational mechanistic study has been performed on Pd(II)-catalyzed enantioselective reactions involving acetyl-protected aminomethyl oxazolines (APAO) ligands that significantly improved ...reactivity and selectivity in C(sp3)–H borylation. The results support a mechanism including initiation of C(sp3)–H bond activation generating a five-membered palladacycle and ligand exchange, followed by HPO4 2–-promoted transmetalation. These resulting Pd(II) complexes further undergo sequential reductive elimination by coordination of APAO ligands and protonation to afford the enantiomeric products and deliver Pd(0) complexes, which will then proceed by oxidation and deprotonation to regenerate the catalyst. The C(sp3)–H activation is found to be the rate- and enantioselectivity-determining step, in which the APAO ligand acts as the proton acceptor to form the two enantioselectivity models. The results demonstrate that the diverse APAO ligands control the enantioselectivity by differentiating the distortion and interaction between the major and minor pathways.
Controlled atmosphere treatments with ultralow oxygen (ULO treatments) were developed successfully for control of vine mealybug, Planococcus ficus Signoret (Hemiptera: Pseudococcidae), on dormant ...grape (Vitis spp.) benchgrafts. At 30 ppm oxygen, 3-d ULO treatment at 25°C and 4-d ULO treatment at 15°C achieved complete control of all life stages of P. ficus. At a much lower oxygen level (<1 ppm), the two ULO treatments with the same exposure periods of 3 d at 25°C and 4 d at 15°C were tested on six table and wine grape cultivars grafted on rootstocks along with P. ficus. The benchgrafts were then potted in a greenhouse, together with untreated controls, to determine treatment effects on rootstock viability, Both ULO treatments achieved complete control of P. ficus and did not have any negative effects on vine growth, compared with the control. Results indicate that ULO treatments can be used to control P. ficus on dormant grape benchgrafts. The advantages of the ULO treatments are also discussed with respect to hot water treatments.
•A method for calculating the optimal interval of air stoichiometry is proposed.•Synthetically consider fuel cell power, working efficiency and gas starvation.•Calculate air stoichiometry optimal ...interval under different operating conditions.•Changing trends of optimal interval varying with operating conditions are analyzed.•Evaluate gas starvation by calculating the proportion of gas-starvation area.
Cathode air stoichiometry is one of the crucial factors affecting the electrical performance and local gas starvation of proton exchange membrane fuel cells. A suitable air stoichiometric ratio can not only improve the generated power and working efficiency, but also effectively reduce or eliminate internal reactant gas starvation. At present, the optimal value of cathode air stoichiometry and its changing trends under different operating conditions remains to be further studied, and the optimization indicator in existing researches mainly tends to be maximum power, with rare attention to fuel cell degradation. This paper proposes a quantitative method for calculating the optimal interval of air stoichiometry, which considers synthetically the fuel cell generated power, working efficiency and internal gas starvation reduction, to make these three indicators reach the optimal balance. The local gas starvation inside is evaluated by proportion of gas-starvation area on fuel cell electrode surface. Based on the proposed methodology, a three-dimensional model of a five-channel serpentine flow field fuel cell is established in this paper to simulate and calculate the optimal interval of cathode air stoichiometry under different operational parameters and electrical load conditions. The changing trends of the optimal air stoichiometry with different operating conditions and the impacts of key operational parameters and loads on air stoichiometry optimal interval are also carefully analyzed. Among them, the operating pressure and current density have a significant influence on the optimal interval value. Increasing the working pressure can make the optimal air stoichiometry smaller, and the increase in current density results in a substantial raise of optimal air stoichiometry. The calculation method of cathode air stoichiometry optimal interval proposed in this paper can provide references for fuel cell air supply strategy research, and the conclusions can be beneficial for fuel cell performance optimization and long-lifetime design.
•Human cervical epithelial cells (HCEs) express the functional IL-22 receptor.•IL-22 inhibits HSV-2 replication in HCEs.•IL-22 induces the expression of ISGs and the tight junction proteins in ...HCEs.•IL-22 has potential as a therapeutic agent to inhibit HSV-2 infection.
Interleukin (IL)-22, a member of the IL-10 family, plays a role in antiviral immune responses to a number of viral infections. However, it is unclear whether IL-22 is involved in the mucosal immunity against herpes simplex virus 2 (HSV-2) infection in the female reproductive tract (FRT). In this study, we studied whether IL-22 could inhibit HSV-2 infection of human cervical epithelial cells (End1/E6E7 cells). We showed that End1/E6E7 cells express the functional IL-22 receptor complex (IL-22R1 and IL-10R2). When treated with IL-22, End1/E6E7 cells expressed the higher levels of IFN-stimulated genes (ISGs: ISG15, ISG56, OAS-1, OAS-2, and Mx2) than untreated cells. In addition, IL-22-treated cells produced higher levels of the tight junction proteins (ZO-1 and Occludin) than untreated cells. Mechanistically, IL-22 could activate the JAK/STAT signaling pathway by inducing the phosphorylation of STAT1 and STAT3. These observations indicate the potential of IL-22 as an anti-HSV-2 agent in the FRT mucosal innate immunity against HSV-2 infection.
The aim of this paper is to examine the Turing instability and pattern formation in the FitzHugh–Nagumo model with super-diffusion in two dimensional numerical simulation. We also studied the effects ...of the super-diffusive exponent on pattern formation concluding that with the presence of super-diffusion the stable homogenous steady state becomes unstable. By using the stability analysis of local equilibrium point, we procure the conditions which ensure that the Turing and Hopf bifurcations occur. For pattern selection, the weak nonlinear multi-scale analysis is used to derive the amplitude equations of the stationary patterns. We then apply amplitude equations and observe that this model has very rich dynamical behaviors, such as stripes, spots and hexagon patterns. The complexity of the dynamics in this system is theoretically discussed and graphically displayed in numerical simulation. The simulation helps us to show the effectiveness of theoretical analysis and patterns which appear numerically.
Measuring the transformation performance of resource-based cities and realizing the sustainable development of resource-based cities are the hotspots of the world. However, there are few studies ...focused on the sustainability of transformation. This paper designed an evaluation system that can comprehensively reflect the transformation and coordination of resource-based cities. The entropy weight method and fuzzy membership function were used to calculate the transformation degree (TD), coordination degree (CD) and transformation sustainability coefficient (TSC) of ten resource-based cities in Shanxi Province of China from 2007 to 2016. The transformation levels of these cities were constantly improving. The contribution of economic industry transformation (EIT) increased from 25.5% to 42.3%, which became the main driving force. The CD of each city fluctuated greatly; however, the overall trend was upward. The CD between social and livelihood transformation (SLT) and ecological and environmental transformation (EET) was the worst. The TSCs of northern and southeastern cities were relatively good, and they were backward in central and southwestern regions. Since 2013, TSC in some cities has declined in various degrees. It is suggested that the sustainable transformation of resource-based cities should be carried out, especially to solve the unemployment problems caused by the closure of mining areas, and strive to improve the coordination between social development and environmental governance. In addition, the government should attach importance to basic education, introduce high-tech industry based on resource utilization to improve the awareness of city transformation from the root, and gradually get rid of the city's dependence on resource exploitation.
•The concept of transformation sustainability coefficient was proposed.•Achieved a comprehensive evaluation of transformation and sustainability.•Propose to strive to coordinate the conflict between the environment and social.
In this work, a selective synthetic strategy towards 1-azaspiro4.5deca-3,6,9-trien-8-ones from N-tosyl-N-(prop-2-yn-1-yl)aniline is developed. The transformation proceeds smoothly in a mixed solvent ...including acetonitrile and water when ZnBr2 and Oxone are employed. Mechanism studies show that the reaction proceeds in a regioselective manner via a radical ipso-cyclization pathway.
The introduction of a CO, CC, CS, or CN bond has emerged as an effective strategy for carbocycle synthesis. A computational mechanistic study of Rh(III)-catalyzed coupling of alkynes with ...enaminones, sulfoxonium ylides, or α-carbonyl-nitrones was carried out. Our results uncover the roles of dual directing groups in the three substrates and confirm that the ketone acts as the role of the directing group while the CC, CN, or CS bond serves as the cyclization site. By comparing the coordination of the ketone versus the CC, CN, or CS bond, as well as the chemoselectivity concerning the six- versus five-membered formation, a competition relationship is revealed within the dual directing groups. Furthermore, after the alkyne insertion, instead of the originally proposed direct reductive elimination mechanism, the ketone enolization is found to be essential prior to the reductive elimination. The following C(sp2)C(sp2) reductive elimination is more favorable than the C(sp3)C(sp2) formation, which can be explained by the aromaticity difference in the corresponding transition states. The substituent effect on controlling the selectivity was also discussed.
In this paper, the characteristics of the extraordinary mode in the 3D magnetized plasma photonic crystals containing the function dielectric with woodpile lattices are investigated in theory. Such ...photonic crystals are called the function dielectric magnetized plasma photonic crystals (FMPPCs), and only the magneto-optical Voigt effect of the magnetized plasma is considered. The configuration of such a FMPPC is that the function dielectric square columns are embedded into the magnetized plasma. The permittivity of the function dielectric is space-depended. The results which are calculated by the plane wave expansion method illustrate that a narrower photonic band gap can be achieved in the proposed FMPPCs compared with the conventional 3D woodpile PCs, which only contain the plasma or function dielectric. The studies also show that the better performance can be realized by optimizing the parameters of FMPPCs, and give us another alternative way to realize the reconfigurable applications with the 3D FMPPCs.
•The features of extraordinary mode in 3D FMPPCs is investigated.•The formulas of PWE method are derived.•Compared to the PPCs and PCs, the narrower PBG can be obtained.•The PBG can be tuned by I, b, R, ωc and ωp.•The FBRs can be tailored by ωc and ωp.
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