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Electrochemical detection of hybridized DNA strands was achieved with a magnetic nanoparticle modified electrode and the commonly used electrochemical couple [K.sub.3][Fe[(CN).sub.6]]/ [K.sub.4][Fe[(CN).sub.6]]. The detection proved to be fast and very simple. Furthermore, magnetic nanoparticles could be employed to control the DNA hybridization process. An inhibited or an enhanced degree of hybridizing could be produced.

Nicotinic acetylcholine receptors(nAChRs) have been investigatedfor developing drugs that can potentially treat various central nervoussystem disorders. Considerable evidence supports the hypothesis thatmodulation of the cholinergic system through activation and/or desensitization/inactivationof nAChR holds promise for the development of new antidepressants.The introductory portion of this Miniperspective discusses the basicpharmacology that underpins the involvement of α4β2-nAChRsin depression, along with the structural features that are essentialto ligand recognition by the α4β2-nAChRs. The remainderof this Miniperspective analyzes reported nicotinic ligands in termsof drug design considerations and their potency and selectivity, witha particular focus on compounds exhibiting antidepressant-like effectsin preclinical or clinical studies. This Miniperspective aims to providean in-depth analysis of the potential for using nicotinic ligandsin the treatment of depression, which may hold some promise in addressingan unmet clinical need by providing relief from depressive symptomsin refractory patients. [ABSTRACT FROM AUTHOR]

A 3-pyridylether scaffold bearing a cyclopropane-containing sidechain was recently identified in our efforts to create novel antidepressantsthat act as partial agonists at α4β2-nicotinic acetylcholinereceptors. In this study, a systematic structure–activity relationshipinvestigation was carried out on both the azetidine moiety presentin compound 3and its right-hand side chain, therebydiscovering a variety of novel nicotinic ligands that retain bioactivityand feature improved chemical stability. The most promising compounds, 24, 26, and 30, demonstrated comparableor enhanced pharmacological profiles compared to the parent compound 4, and the N-methylpyrrolidine analogue 26also exhibited robust antidepressant-like efficacy in themouse forced swim test. The favorable ADMET profile and chemical stabilityof 26further indicate this compound to be a promisinglead as a drug candidate warranting further advancement down the drugdiscovery pipeline. [ABSTRACT FROM AUTHOR]

The discovery of room-temperature ferromagnetism in van der Waals (vdW) materials opens new avenues for exploring low-dimensional magnetism and its applications in spintronics. Recently, the observation of the room-temperature topological Hall effect in the vdW ferromagnet Fe 3 GaTe 2 suggests the possible existence of room-temperature skyrmions, yet skyrmions have not been directly observed. In this study, real-space imaging was employed to investigate the domain evolution of the labyrinth and skyrmion structure. First, Néel-type skyrmions can be created at room temperature. In addition, the influence of flake thickness and external magnetic field (during field cooling) on both labyrinth domains and the skyrmion lattice is unveiled. Due to the competition between magnetic anisotropy and dipole interactions, the specimen thickness significantly influences the density of skyrmions. These findings demonstrate that Fe 3 GaTe 2 can host room-temperature skyrmions of various sizes, opening up avenues for further study of magnetic topological textures at room temperature.

Fusarium head blight (FHB), caused by Fusarium graminearum , is a predominant disease of wheat. Due to the lack of disease-resistant germplasm, chemical control is an important means to control wheat scab. Volatile substances produced in near-isogenic wheat lines were detected after inoculation with F. graminearum , and 4-propylphenol, which appears in FHB-resistant lines, was identified. In vitro and in vivo antifungal activity tests demonstrate that 4-propylphenol effectively inhibits the mycelial growth of F. graminearum . Metabolomics analysis showed changes in glutathione metabolism, indicating that 4-propylphenol triggered reactive oxygen species (ROS) stress. This was consistent with the increasing ROS levels in Fusarium cells treated with 4-propylphenol. Further results demonstrated that excessive accumulation of ROS induced DNA and cell membrane damage in the mycelium. Moreover, 4-propylphenol showed different degrees of inhibition against other soil-borne pathogens (fungi and oomycetes). These findings illustrated that 4-propylphenol has broad spectrum and high antifungal activity and should be considered for use as an ecological fungicide.

Although manganese-based oxides possess high voltage and low cost, the sluggish reaction kinetics and poor structural stability hinder their applications in aqueous rechargeable Zn-ion batteries (ZIBs). Herein, a molybdenum (Mo) pre-intercalation strategy is proposed to solve the above issues of δ-MnO 2 . The pre-intercalated Mo dopants, acting as the interlayer pillars, can not only expand the interlayer spacing but also reinforce the layered structure of δ-MnO 2 , finally achieving enhanced reaction kinetics and superb cycling stability during carrier (de)intercalation. Moreover, oxygen defects, introduced due to Mo-pre-intercalation, play a critical role in the fast reaction kinetics and capacity improvement of the Mo-pre-intercalated δ-MnO 2 (Mo-MnO 2 ) cathode. Therefore, the Mo-MnO 2 cathode displays a high energy density of 451 Wh kg -1 (based on cathode mass), excellent rate capability, and admirable long-term cycling performance with a high capacity of 159 mAhg -1 at 1.0 A g -1 after 1000 cycles. In addition, the energy storage mechanism of Zn 2+ /H + stepwise reversible (de)intercalation is also revealed by ex situ experiments. This work provides an insightful guide for boosting the electrochemical performance of Mn-based oxide cathodes for ZIBs.

Double-perovskite oxides have attracted recent attention due to their attractive functionalities and application potential. In this paper, we demonstrate the effect of dual controls, i.e., the deposition pressure of oxygen ( P O 2 ) and lattice mismatch (ε), on tuning magnetic properties in epitaxial double-perovskite Sr 2 FeReO 6 films. In a nearly lattice matched Sr 2 FeReO 6 /SrTiO 3 film, the ferrimagnetic-to-paramagnetic phase transition occurs when P O 2 is reduced to 30 mTorr, probably due to the formation of Re 4+ ions that replace the stoichiometric Re 5+ to cause disorders of B-site ions. On the other hand, a large compressive strain or tensile strain shifts this critical P O 2 to below 1 mTorr or above 40 mTorr, respectively. The observations can be attributed to the modulation of B-site ordering by epitaxial strain through affecting elemental valence. Our results provide a feasible way to expand the functional tunability of magnetic double-perovskite oxides that hold great promise for spintronic devices.

Aqueous Zn/MnO 2 batteries exhibit huge potential for grid-scale energy storage but suffer from poor cycling stability derived from both structural instability of cathode and Zn dendrite growth of anode. Here, we report a high-performance aqueous Zn/MnO 2 battery with ZnSO 4 -based electrolyte, comprising a nanoparticle-like cathode with abundant surface oxygen defects (MO-V o ) and a dendrite-free Zn anode. The transformation from nanowire (α-MnO 2 ) to nanoparticle (MO-V o ) was found by tuning the annealing conditions in an argon flow. Moreover, the small size of MO-V o nanoparticles can effectively promote the spatially uniform distribution of volume stress during carrier intercalation, boosting the structural stability of the MO-V o cathode. Moreover, it was found that the intercalation pseudocapacitive behavior of Zn 2+ in the MO-V o cathode can be strongly boosted by tailoring the surface oxygen defect of MnO 2 based on the calculations and experiments, thereby achieving enhanced cycling stability and redox kinetics. Additionally, the addition of K 2 SO 4 additive into the electrolyte can tailor the deposition behavior of Zn 2+ , enabling stable Zn stripping/plating without dendrites. Therefore, the assembled Zn/MO-V o batteries exhibit a high energy density and excellent long-term cyclability over 1400 cycles. Besides, the reaction mechanism of pseudocapacitive Zn 2+ intercalation and H + intercalation for the MO-V o cathode was revealed via ex situ characterizations.

Ultrathin freestanding membranes with a pronounced metal-insulator transition (MIT) have huge potential for future flexible electronic applications as well as provide a unique aspect for the study of lattice-electron interplay. However, the reduction of the thickness to an ultrathin region (a few nm) is typically detrimental to the MIT in epitaxial films, and even catastrophic for their freestanding form. Here, we report an enhanced MIT in VO 2 -based freestanding membranes, with a lateral size up to millimeters and the VO 2 thickness down to 5 nm. The VO 2 membranes were detached by dissolving a Sr 3 Al 2 O 6 sacrificial layer between the VO 2 thin film and the c -Al 2 O 3 (0001) substrate, allowing the transfer onto arbitrary surfaces. Furthermore, the MIT in the VO 2 membrane was greatly enhanced by inserting an intermediate Al 2 O 3 buffer layer. In comparison with the best available ultrathin VO 2 membranes, the enhancement of MIT is over 400% at a 5 nm VO 2 thickness and more than 1 order of magnitude for VO 2 above 10 nm. Our study widens the spectrum of functionality in ultrathin and large-scale membranes and enables the potential integration of MIT into flexible electronics and photonics.

Bio-optical imaging can noninvasively describe specific biochemical reaction events in small animals using endogenous or exogenous imaging reagents to label cells, proteins, or DNA. The fluorescence optical bio-imaging system excites the fluorescent group to a high energy state by excitation light and then generates emission light. However, many substances in the organism will also emit fluorescence after being excited by the excitation light, and the nonspecific fluorescence generated will affect the detection sensitivity. This paper designs and develops a set of high-level biosafety in vivo fluorescence imaging system for small animals suitable for virology research and proposes a target area extraction algorithm for fluorescence images. The fluorescence image target extraction algorithm first maps the nonlinear separation data in the low-dimensional space to the high-dimensional space. Then, based on the analysis of the characteristics of the fluorescent region, a method for discriminating the target fluorescent region based on the two-step entropy function is proposed, and the real target fluorescent region is obtained according to the set connected region. Based on the experiment of collecting and analyzing the in vivo fluorescent images of mice, it is verified that the proposed algorithm can automatically extract the target fluorescent region better than the classical linear model. It shows that the proposed algorithm is less affected by background fluorescence, and the estimated separated spectrum based on this method is closer to the real target spectrum., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

The prostanoid EP4 receptor is one of the key receptors associated with inflammatory mediator PGE 2 -elicited immunosuppression in the tumor microenvironment. Blockade of EP4 signaling to enhance immunity-mediated tumor elimination has recently emerged as a promising strategy for cancer immunotherapy. In our efforts to discover novel subtype-selective EP4 antagonists, we designed and synthesized a class of 1 H -1,2,3-triazole-based ligands that display low nanomolar antagonism activity toward the human EP4 receptor and excellent subtype selectivity. The most promising compound 59 exhibits single-digit nanomolar potency in the EP4 calcium flux and cAMP-response element reporter assays and effectively suppresses the expression of multiple immunosuppression-related genes in macrophage cells. On the basis of its favorable ADMET properties, compound 59 was chosen for further in vivo biological evaluation. Oral administration of compound 59 significantly inhibited tumor growth in the mouse CT26 colon carcinoma model accompanied by enhanced infiltration of cytotoxic T lymphocytes in the tumor tissue.

Potassium-ion batteries are potential alternatives to lithium-ion batteries for large-scale energy storage considering the low cost and high abundance of potassium. However, it is challenging to obtain stable electrode materials capable of undergoing long-term potassiation/depotassiation due to the high accumulated stress associated with the huge volume variation of the electrode. Here, we simulate the von Mises stress distributions of four different carbon three-dimensional models under an isotropic initial stress by the finite element method and reveal the critical role of the structure of a hollow multihole bowl on the strain-relaxation behavior. In this regard, nitrogen/oxygen codoped carbon hollow multihole bowls (CHMBs) are synthesized via hydrothermal carbonization coupled with an emulsion-templating strategy using biomass as the carbon source. Consistent with our simulation results, the CHMB anode remains stable for over 1000 cycles and delivers a high reversible capacity of 304 mAh g -1 at 0.1 A g -1 . In addition to the reduced stress accumulation, the good electrochemical performances are also attributed to the surface capacitive mechanism and the shortened electron/ion transport distance in CHMBs. In particular, the CHMB composite electrode has a volumetric specific capacity 56% higher than that of hollow spheres due to the high tapped density of the bowl-shaped particles.

Transition metal sulfides are deemed as attractive anode materials for potassium-ion batteries (KIBs) due to their high theoretical capacities based on conversion and alloying reaction. However, the main challenges are the low electronic conductivity, huge volume expansion, and consequent formation of unstable solid electrolyte interphase (SEI) upon potassiation/depotassiation. Herein, zinc sulfide dendrites deeply nested in the tertiary hierarchical structure through a solvothermal-pyrolysis process are designed as an anode material for KIBs. The tertiary hierarchical structure is composed of the primary ultrafine ZnS nanorods, the secondary carbon nanosphere, and the tertiary carbon-encapsulated ZnS subunits nanosphere structure. The architectural design of this material provides a stable diffusion path and enhances effective conductivity from the interior to exterior for both K + ions and electrons, buffers the volume expansion, and constructs a stable SEI during cycling. A stable specific capacity of 330 mAh g -1 is achieved after 100 cycles at the current density of 50 mA g -1 and 208 mAh g -1 at 500 mA g -1 over 300 cycles. Using density functional theory calculations, we discover the interactions between ZnS and carbon interface can effectively decrease the K + ions diffusion barrier and therefore promote the reversibility of K + ions storage.

Engineering ferromagnetism, by modulating its magnitude or anisotropy, is an important topic in the field of magnetism and spintronics. Among different types of magnetic materials, ferromagnetic insulators, in which magnetic moment unusually coexists with localized electrons, are of particular interest. Here, we report a remarkable interfacial enhancement of the ferromagnetism by adding one unit-cell LaAlO 3 adjacent to an insulating LaMnO 3 ultrathin film. The enhancement of ferromagnetism is explained in terms of charge transfer at the interface, as evidenced by X-ray absorption spectroscopy and ab initio calculations. This study demonstrates an effective and dramatic approach to modulate the functionality of ferromagnetic insulators, contributing to the arsenal of engineering techniques for future spintronics.

Electrolyte gating is widely used to induce large carrier density modulation on solid surfaces to explore various properties. Most of past works have attributed the charge modulation to electrostatic field effect. However, some recent reports have argued that the electrolyte gating effect in VO 2 , TiO 2 , and SrTiO 3 originated from field-induced oxygen vacancy formation. This gives rise to a controversy about the gating mechanism, and it is therefore vital to reveal the relationship between the role of electrolyte gating and the intrinsic properties of materials. Here, we report entirely different mechanisms of electrolyte gating on two high-T c cuprates, NdBa 2 Cu 3 O 7-δ (NBCO) and Pr 2-x Ce x CuO 4 (PCCO), with different crystal structures. We show that field-induced oxygen vacancy formation in CuO chains of NBCO plays the dominant role, while it is mainly an electrostatic field effect in the case of PCCO. The possible reason is that NBCO has mobile oxygen in CuO chains, while PCCO does not. Our study helps clarify the controversy relating to the mechanism of electrolyte gating, leading to a better understanding of the role of oxygen electro migration which is very material specific.

Electric field effect in electronic double layer transistor (EDLT) configuration with ionic liquids as the dielectric materials is a powerful means of exploring various properties in different materials. Here, we demonstrate the modulation of electrical transport properties and extremely high mobility of two-dimensional electron gas at LaAlO3/SrTiO3 (LAO/STO) interface through ionic liquid-assisted electric field effect. With a change of the gate voltages, the depletion of charge carrier and the resultant enhancement of electron mobility up to 19 380 cm(2)/(V s) are realized, leading to quantum oscillations of the conductivity at the LAO/STO interface. The present results suggest that high-mobility oxide interfaces, which exhibit quantum phenomena, could be obtained by ionic liquid-assisted field effect.

Since the discovery of two-dimensional electron gas (2DEG) at the oxide interface of LaAlO3/SrTiO3 (LAO/STO), improving carrier mobility has become an important issue for device applications. In this paper, by using an alternate polar perovskite insulator (La0.3Sr0.7) (Al0.65Ta0.35)O3 (LSAT) for reducing lattice mismatch from 3.0% to 1.0%, the low-temperature carrier mobility has been increased 30 fold to 35,000 cm(2) V(-1) s(-1). Moreover, two critical thicknesses for the LSAT/STO (001) interface are found, one at 5 unit cells for appearance of the 2DEG and the other at 12 unit cells for a peak in the carrier mobility. By contrast, the conducting (110) and (111) LSAT/STO interfaces only show a single critical thickness of 8 unit cells. This can be explained in terms of polar fluctuation arising from LSAT chemical composition. In addition to lattice mismatch and crystal symmetry at the interface, polar fluctuation arising from composition has been identified as an important variable to be tailored at the oxide interfaces to optimize the 2DEG transport.

Silver orthophosphate (Ag3PO4) is a low-band-gap photocatalyst that has received considerable research interest in recent years. In this work, the magnetic Ag3PO4/TiO2/Fe3O4 heterostructured nanocomposite was synthesized. The nanocomposite was found to exhibit markedly enhanced photocatalytic activity, cycling stability, and long-term durability in the photodegradation of acid orange 7 (AO7) under visible light. Moreover, the antibacterial film prepared from Ag3PO4/TiO2/Fe3O4 nanocomposite presented excellent bactericidal activity and recyclability toward Escherichia coli (E. coli) cells under visible-light irradiation. In addition to the intrinsic cytotoxicity of silver ions, the elevated bactericidal efficiency of Ag3PO4/TiO2/Fe3O4 can be largely attributed to its highly enhanced photocatalytic activity. The photogenerated hydroxyl radicals and superoxide ions on the formed Ag/Ag3PO4/TiO2 interfaces cause considerable morphological changes in the microorganism's cells and lead to the death of the bacteria.

Clenbuterol, a member of β-agonist family, has now been a serious threat to human health due to its illegal usage in the livestock feeding. Herein, we describe the application of melamine functionalized silver nanoparticles (M-AgNPs) as the electrochemical probe for simple, fast, highly sensitive and selective detection of clenbuterol. Generally, AgNPs are prepared and functionalized by melamine. After interacting with melamine modified gold electrode in the presence of clenbuterol, M-AgNPs can be immobilized on the surface of the electrode via the hydrogen-bonding interactions between clenbuterol and melamine. This sandwich structure permits sensitive and selective detection of clenbuterol. Since M-AgNPs can provide a couple of well-defined sharp silver stripping peaks, which stands for a highly characteristic solid-state Ag/AgCl reaction, a rather low detection limit of 10 pM can be achieved. The detection range is from 10 pM to 100 nM, which is quite wide. This developed biosensor can potentially be used for clenbuterol detection in biological fluids in the presence of various interferences.

Comparative analyses of the pharmacophoric elements required for σ1 and nicotinic ligands led to the identification of a potent and selective σ1 ligand ( 15 ). Compound 15 displayed high selectivity for the σ1 receptor ( K i , σ1 = 4.1 nM, K i , σ2 = 1312 nM) with moderate binding affinity for the DAT ( K i = 373 nM) and NET ( K i = 203 nM) in the PDSP broad screening panel of common CNS neurotransmitter transporters and receptors. The key finding in this present work is that a subtle structural modifica tion could be used as a tool to switch a ligand's selectivity between nAChRs and sigma receptors.

In our continued efforts to develop α4β2-nicotinic acetylcholine receptor (nAChR) partial agonists as novel antidepressants having a unique mechanism of action, structure-activity relationship (SAR) exploration of certain isoxazolylpyridine ethers is presented. In particular, modifications to both the azetidine ring present in the starting structure 4 and its metabolically liable hydroxyl side chain substituent have been explored to improve compound druggability. The pharmacological characterization of all new compounds has been carried out using [(3)H]epibatidine binding studies together with functional assays based on (86)Rb(+) ion flux measurements. We found that the deletion of the metabolically liable hydroxyl group or its replacement by a fluoromethyl group not only maintained potency and selectivity but also resulted in compounds showing antidepressant-like properties in the mouse forced swim test. These isoxazolylpyridine ethers appear to represent promising lead candidates in the design of innovative chemical tools containing reporter groups for imaging purposes and of possible therapeutics.

Atomic force microscopy (AFM) was used to characterize the surface damage (nanoindentations) effect on the chemical durability of glass surfaces (silica and soda-lime silicate glasses, WG). In basic solutions, an enhanced dissolution rate is reported and quantified at indentation sites (+10.5 nm/h and +52 nm/h for silica and WG, respectively) whereas none was observed once the indented surfaces were thermally annealed at 0.9 × T(g) for 2 h, a thermal treatment known for curing high pressure-induced permanent densification in oxides glasses. A direct link between high pressure-induced structural modifications encountered during nanoindentation and the measured dissolution rates is established. It is shown that this property conjointly used with the high resolution of the atomic force microscope may be used for probing, at the nanometer scale, the size and the nature of the structurally modified area underneath residual nanoindentation impressions. As an example, for 10 mN Vickers nanoindentations on WG, the zone affected by the permanently and structurally modified zone under the residual impression is found to be equal to (741 ± 30) nm with a transition zone thickness from the fully densified material to the elastically deformed one ranging between 115 and 165 nm.

Ordered 2D non-close-packed sphere arrays with controllable lattice structures have been fabricated by using soft lithography based on the solvent-swelling and mechanical deformation behaviors of PDMS film. The figure shows an SEM image of the ordered quasi-one-dimensional parallel wires of silica spheres on a polymer-coated substrate.

Volatile organic compounds (VOCs) containing gases exhausted from industrial processes are highly toxic to human health; therefore, their safe elimination is extremely important. This paper describes how a novel prototype microwave plasma reactor was sequentially improved. The design concepts for each modification are also carefully described. For testing the reactor's performance, ethanol was selected as the target VOC. The decomposing and removal efficiency (DRE) value was used to evaluate the reactor's performance. The final stage of the revamping reactor was evaluated to meet the requirements of both stability and long term, high volume operation. When studying the VOC treatment operations, oxygen, air, and water vapor were used as carrier gases or additives to improve the efficiency of the DRE value and to facilitate the ethanol treatment. A DRE value higher than 99% was obtained under these optimal conditions: an ethanol vapor flow rate of 1730 cm3/min (67 mbar, 150 degrees C), power input higher than 1.5 kW, a frequency of 200 Hz, an air flow rate of 100 cm3/min (4 atm, 25 degrees C), and a liquid water addition rate higher than 0.21 mL/min (1 atm, 25 degrees C). With these conditions, the initial concentration of ethanol vapor mixed with the carrier gas was about 7-10%. Because of high processing efficiency and capacity of this system, it could be a potential alternative tool for treating industrial VOCs.