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Ferroelectricity with switchable polarizations is generally associated with small ion-displacements and occurs only in 10 specific polar point groups, which is not a necessary requirement for ion conduction where the ions can also be electrically displaced but by much longer distances. Herein, through first-principles calculations, we predict the formation of unconventional ferroelectricity based on previous experimental reports on topotactic reaction with an aliovalent cation between trigonal layers of ion conductors. In such systems, the multivalent cations are surrounded by vacant sites that can simultaneously migrate by a much larger distance compared with conventional displacive ferroelectricity, giving rise to a quantized change in polarization even if the crystal lattices do not belong to the 10 polar groups. The deviation from classical principles can be attributed to the long ion displacements in ferroelectric ion conductors during switching that can lead to the transformation between multiple equivalent symmetrical stable states, which cannot be realized by the relatively small ion displacements in current ferroelectrics. The evenly distributed vacant sites due to Coulomb repulsion do not break the insulativity of the systems, while their inhomogeneous distribution under an electric field or in ferroelectric domain walls will give rise to high electrical conductance, which may be utilized for constructing nanoscale artificial ionic synapses that enable neuromorphic computing.

Organic memristors with low power consumption, fast write/erasure speed, and complementary metal-oxide-semiconductor(CMOS) compatibility have attracted tremendous attention to mimic biological synapses to realize neuromorphic computation in recent years. In this paper, organic resistive switching memory(ORSM) based on (Z)-3-(naphthalen-2-yl)-2-(4-nitrophenyl)acrylonitrile(NNA) and polymer poly(N-vinylcarbazole)(PVK) composite film was prepared by spin-coating method. Device performance based on NNA:PVK composite films with different mass fractions of NNA were systematically investigated. The ORSM based on PVK:40%(mass fraction) NNA composite film exhibited non-volatile and bipolar memory properties with a switching ratio(Ion/Ioff) of 24.1, endurance of 68 times and retention time of 104s, a “SET” voltage(Vset) of −0.55 V and a “RESET” voltage(Vreset) of 2.35 V. The resistive switching was ascribed to the filling and vacant process of the charge traps induced by NNA and the inherent traps in PVK bulk. The holes trapping and de-trapping process occurred when the device was applied with a negative or positive bias, which caused the transforming of the conductive way of charges, that is the resistive behaviors in the macroscopic. This study provides a promising platform for the fabrication of ORSM with high performance.

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No head-to-head clinical trials compare contemporary first-line therapies for metastatic renal cell carcinoma (mRCC). A network meta-analysis provides an approach for quantitative analysis.

A diffusive single species model with stage structure and strong Allee effect subject to homogeneous Neumann boundary condition is considered. The stability of the nonnegative equilibria and the existence of Hopf bifurcation are investigated by analyzing the corresponding characteristic equation. Moreover, by the theory of normal form and center manifold, the stability and direction of bifurcating periodic solutions are determined. Finally, some numerical simulations are carried out. [ABSTRACT FROM AUTHOR]

Narrowly dispersed polyurethane (PU) nanocapsules containing lavender essential oil (LO) were fabricated by polyaddition of toluene diisocyanate (TDI) trimer with polyol using a phase inversion emulsification technique. The particle size distribution (PSD), surface morphology, structure, encapsulation parameters, release properties, and thermal stability of nanocapsules have been characterized using a laser particle size analyzer (LPSA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectrum (FTIR), and thermogravimetric analysis (TGA), respectively. Experimental results demonstrate that the nanocapsules have a smaller size (ca. 268 nm), regular sphericity, uniform particle size (polydispersity index, PDI = 0.078), clear core–shell structure, and smooth surface. When the ratio of LO to TDI trimer is 5:10, the yield, encapsulation efficiency, and loading capacity of the nanocapsules can reach a maximum of 70.7%, 98.6%, and 64.8%, respectively. Furthermore, the release experiments showed that the cumulative release of LO from nanocapsules was only about 17% at room temperature and about 32% at 50 °C even after 20 days.

The plant-specific NAC (NAM, ATAF1/2, and CUC2) transcription factors have a regulatory function in developmental processes and stress responses. Notably a group of NAC members named NTLs (NTM1-Like) are membrane-tethered, ensuring plants rapidly respond to developmental changes and environmental stimuli. Our results indicated that ANAC089 was a membrane-tethered transcription factor and its truncated form was responsible for the physiological function in flowering time control.

Senescence is a complex and highly regulated process. Leaf senescence is influenced by endogenous developmental and external environmental signals. In this work, we found that expression of an Ap2/DREB-type transcription factor gene, Arabidopsis Rap2.4f(At4g28140), was upregulated by salt, mannitol, and dark treatments. Constitutively overexpressing Rap2.4funder the control of the CaMV 35S promoter led to an increased chlorophyll degradation rate and upregulation of many senescence-associated genes in the transgenic Arabidopsislines. Our results show that Rap2.4fis a positive regulator of senescence, promoting both developmental and dark-induced leaf senescence.

A simple and environmentallyfriendly processing method was used to prepare thermoplastic starch TPS montmorillonite MMT nanocomposites. Xray diffraction XRD and transmission electron microscopy TEM demonstrated that glycerol could enlarge the dspacing and destruct the layered structure of MMT effectively during the preprocessing of MMT. So the enlarged dspacing and fragmentized platelets of glycerol activatedMMT were a precondition to form intercalated or exfoliated TPSbased nanocomposites during the melt extrusion processing. These highly dispersive and compatible TPSactivatedMMT nanocomposites had increased thermal stability and tensile properties as compared with nonactivated composites. Especially, the tensile strength of nanocomposites could be enhanced to 8.6 MPa, the improvement was about two times the initial tensile strength of TPS.