Integration of image preprocessing and recognition functions in an optoelectronic coupling organic ferroelectric retinomorphic neuristor.

The human visual system (HVS) has the advantages of a low power consumption and high efficiency because of the synchronous perception and early preprocessing of external image information in the retina, as well as parallel in-memory computing within the visual cortex. Realizing the biofunction simulation of the retina and visual cortex in a single device structure provides opportunities for performance improvements and machine vision system (MVS) integration. Here, we fabricate organic ferroelectric retinomorphic neuristors that integrate the retina-like preprocessing function and recognition of the visual cortex in a single device architecture. Benefiting from the electrical/optical coupling modulation of ferroelectric polarization, our devices show a bidirectional photoresponse that acts as the basis for mimicking retinal preconditioning and multi-level memory capabilities for recognition. The MVS based on the proposed retinomorphic neuristors achieves a high recognition accuracy of ∼90%, which is 20% higher than that of the incomplete system without the preprocessing function. In addition, we successfully demonstrate image encryption and optical programming logic gate functions. Our work suggests that the proposed retinomorphic neuristors offer great potential for MVS monolithic integration and functional expansion.

A review of extraction, purification, structural properties and biological activities of legumes polysaccharides.

In recent years, polysaccharides derived from legumes polysaccharides have aroused worldwide interests. Phytochemical and pharmacological studies have studied the physicochemical properties (emulsification, stability and foaming) and demonstrated the biological activities (immune regulation, anti-oxidation, anti-tumor, hypoglycemic, hypolipidemic and intestinal flora regulation) of legumes polysaccharides. Besides, it is reported that the extraction methods will affect the structural features of polysaccharides, thus further changing their physicochemical properties and biological activities. This review appraised the available literatures described the extraction, purification, structural characterization, biological activity and functional properties of legumes polysaccharides in recent years. It can provide useful research underpinnings and updated information for the development and application of related polysaccharides in functional food and medicinal field.

Molecular-Layer-Defined Asymmetric Schottky Contacts in Organic Planar Diodes for Self-Powered Optoelectronic Synapses.

Optoelectronic synapses have been utilized as neuromorphic vision sensors for image preprocessing in artificial visual systems. Self-powered optoelectronic synapses, which can directly convert optical power into electrical power, are promising for practical applications. The Schottky junction tends to be a promising candidate as the energy source for electrical operations. However, fully utilizing the potential of Schottky barriers is still challenging. Herein, organic self-powered optoelectronic synapses with planar diode architecture are fabricated, which can simultaneously sense and process ultraviolet (UV) signals. The photovoltaic operations are facilitated by the built-in potential originating from the molecular-layer-defined asymmetric Schottky contacts. Diverse synaptic behaviors under UV light stimulation without external power supplies are facilitated by the interfacial carrier-capturing layer, which emulates the membranes of synapses. Furthermore, retina-inspired image preprocessing functions are demonstrated on the basis of synaptic plasticity. Therefore, our devices provide the potential for the development of power-efficient and advanced artificial visual systems.

Structural Elucidation and Antioxidant Activities of a Neutral Polysaccharide From Arecanut (Areca catechu L.).

A novel neutral polysaccharide designated as PAP1b was isolated from Areca catechu L. by hot water extraction, ethanol precipitation, and column chromatography. PAP1b was mainly composed of mannose, galactose, xylose, and arabinose in a ratio of 4.1:3.3:0.9:1.7, with an average molecular weight of 37.3 kDa. Structural characterization indicated that the backbone of PAP1b appeared to be composed mainly of → 6-ß-Manp-(1 →, → 4)-α-Galp-(1 → and → 3,6)-ß-Manp-(1 →) residues with some branches, and terminal of (1 →)-linked-ß-Manp residues. The results of bioactivity experiments showed that PAP1b had antioxidant in vitro, esspecially on scavenging DPPH and hydroxyl radicals. Therefore, the polysaccharide from Areca catechu L. could be used as a potential antioxidant in functional food.

Retina-Inspired Self-Powered Artificial Optoelectronic Synapses with Selective Detection in Organic Asymmetric Heterojunctions.

The retina, the most crucial unit of the human visual perception system, combines sensing with wavelength selectivity and signal preprocessing. Incorporating energy conversion into these superior neurobiological features to generate core visual signals directly from incoming light under various conditions is essential for artificial optoelectronic synapses to emulate biological processing in the real retina. Herein, self-powered optoelectronic synapses that can selectively detect and preprocess the ultraviolet (UV) light are presented, which benefit from high-quality organic asymmetric heterojunctions with ultrathin molecular semiconducting crystalline films, intrinsic heterogeneous interfaces, and typical photovoltaic properties. These devices exhibit diverse synaptic behaviors, such as excitatory postsynaptic current, paired-pulse facilitation, and high-pass filtering characteristics, which successfully reproduce the unique connectivity among sensory neurons. These zero-power optical-sensing synaptic operations further facilitate a demonstration of image sharpening. Additionally, the charge transfer at the heterojunction interface can be modulated by tuning the gate voltage to achieve multispectral sensing ranging from the UV to near-infrared region. Therefore, this work sheds new light on more advanced retinomorphic visual systems in the post-Moore era.

The receptor-like cytoplasmic kinase CDG1 negatively regulates Arabidopsis pattern-triggered immunity and is involved in AvrRpm1-induced RIN4 phosphorylation.

Arabidopsis CDG1 negatively regulates flg22- and chitin-triggered immunity by promoting FLS2 and CERK1 degradation and is partially required for bacterial effector AvrRpm1-induced RIN4 phosphorylation. Negative regulators play indispensable roles in pattern-triggered immunity in plants by preventing sustained immunity impeding growth. Here, we report Arabidopsis thaliana CONSTITUTIVE DIFFERENTIAL GROWTH1 (CDG1), a receptor-like cytoplasmic kinase VII member, as a negative regulator of bacterial flagellin/flg22- and fungal chitin-triggered immunity. CDG1 can interact with the flg22 receptor FLAGELLIN SENSITIVE2 (FLS2) and chitin co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (CERK1). CDG1 overexpression impairs flg22 and chitin responses by promoting the degradation of FLS2 and CERK1. This process requires the kinase activity of MEK KINASE1 (MEKK1), but not the Plant U-Box (PUB) ubiquitin E3 ligases PUB12 and PUB13. Interestingly, the Pseudomonas syringae effector AvrRpm1 can induce CDG1 to interact with its host target RPM1-INTERACTING PROTEIN4 (RIN4), which depends on the ADP-ribosyl transferase activity of AvrRpm1. CDG1 is capable of phosphorylating RIN4 in vitro at multiple sites including Thr166 and the AvrRpm1-induced Thr166 phosphorylation of RIN4 is diminished in cdg1 null plants. Accordingly, CDG1 knockout attenuates AvrRpm1-induced hypersensitive response and increases the growth of AvrRpm1-secreting bacteria in plants. Unexpectedly, AvrRpm1 can also induce FLS2 depletion, which is fully dependent on RIN4 and partially dependent on CDG1, but does not require the kinase activity of MEKK1. Collectively, this study reveals previously unknown functions of CDG1 in both pattern-triggered immunity and effector-triggered susceptibility in plants.

Arabidopsis lysin motif/F-box-containing protein InLYP1 fine-tunes glycine metabolism by degrading glycine decarboxylase GLDP2.

Lysin motif (LysM) is a carbohydrate-binding module often found in secreted or transmembrane proteins in living organisms from prokaryotes to eukaryotes. Thus far, all characterized LysM-containing proteins in plants are plasma membrane-resident receptors or co-receptors playing roles in plant-microbe interactions. Here, we interrogate the Arabidopsis LysM/F-box-containing protein InLYP1 and reveal its function in glycine metabolism. InLYP1 was mainly expressed by vigorously growing tissues, encoding a nuclear-cytoplasmic protein. We validated InLYP1 as part of the SKP1-CULLIN1-F-box E3 complex for mediating protein degradation. The glycine decarboxylase P-protein 1 (GLDP1) was identified as an InLYP1-interacting protein by both immunoprecipitation/mass spectrometry and yeast two-hybrid library screening. InLYP1 could also interact with GLDP2, a paralog of GLDP1 with weaker catalytic activity, and could mediate the degradation of GLDP2 but not GLDP1. Interestingly, both GLDPs could be O-glycosylated and form homodimers or heterodimers. Overexpression of InLYP1L9A encoding a dominant-negative variant could cause seedling germination retardation on the medium containing glycine. Collectively, these results shed light on the function of plant intracellular LysM-containing proteins, and suggest that InLYP1 may deplete GLDP2 to facilitate glycine decarboxylation in Arabidopsis.

A Smarter Pavlovian Dog with Optically Modulated Associative Learning in an Organic Ferroelectric Neuromem.

Associative learning is a critical learning principle uniting discrete ideas and percepts to improve individuals' adaptability. However, enabling high tunability of the association processes as in biological counterparts and thus integration of multiple signals from the environment, ideally in a single device, is challenging. Here, we fabricate an organic ferroelectric neuromem capable of monadically implementing optically modulated associative learning. This approach couples the photogating effect at the interface with ferroelectric polarization switching, enabling highly tunable optical modulation of charge carriers. Our device acts as a smarter Pavlovian dog exhibiting adjustable associative learning with the training cycles tuned from thirteen to two. In particular, we obtain a large output difference (>103), which is very similar to the all-or-nothing biological sensory/motor neuron spiking with decrementless conduction. As proof-of-concept demonstrations, photoferroelectric coupling-based applications in cryptography and logic gates are achieved in a single device, indicating compatibility with biological and digital data processing.

Molecular Layer-Defined Transition of Carrier Distribution and Correlation with Transport in Organic Crystalline Semiconductors.

Despite the great efforts to unveil the charge carrier behavior at the semiconductor/dielectric interface of organic field-effect transistors, an examination of the interfacial carrier distribution and the correlation with the charge transport in molecular crystalline semiconductors remains fundamental for understanding the nature of the microscopic carrier motion. Hence, an effective approach to accurately tune the carrier distribution with molecular-layer precision is essential. Here, we find that the carrier accumulation is strictly modulated in highly ordered, few-layer molecular crystalline semiconducting films by tuning the polaronic coupling between the charge carriers and dielectric. The admittance method reveals that the carriers distribute only within a monolayer with stronger localization on a high-κ dielectric and extend to a second layer with better delocalization on a low-κ dielectric. Furthermore, a unique dimensional transition in the charge transport at the dielectric interface is evidenced under a transistor architecture by temperature-dependent measurements. The presented microscopic nature of charge carriers with layer-defined precision in molecular crystalline films should provide an unprecedented opportunity in organic electronics in terms of interface engineering, quantum transport, and device physics.

Engineering plants to secrete affinity-tagged pathogen elicitors for deciphering immune receptor complex or inducing enhanced immunity.

Plant cells mount plenty of pattern-recognition receptors (PRRs) to detect the microbe-associated molecular patterns (MAMPs) from potential microbial pathogens. MAMPs are overrepresented by proteinaneous patterns, such as the flg22 peptide from bacterial flagellin. Identification of PRR receptor complex components by forward or reverse genetics can be time/labor-consuming, and be confounded by functional redundancies. Here, we present a strategy for identifying PRR complex components by engineering plants to inducibly secrete affinity-tagged proteinaneous MAMPs to the apoplast. The PRR protein complexes bound to self-secreted MAMPs are enriched through affinity purification and dissected by mass spectrometry. As a proof of principle, we could capture the flg22 receptor FLS2 and co-receptor BAK1 using Arabidopsis plants secreting FLAG-tagged flg22 under estradiol induction. Moreover, we identified receptor-like kinases LIK1 and PEPR1/PEPR2 as potential components in the FLS2 receptor complex, which were further validated by protein-protein interaction assays and the reverse genetics approach. Our study showcases a simple way to biochemically identify endogenous PRR complex components without overexpressing the PRR or using chemical cross-linkers, and suggests a possible crosstalk between different immune receptors in plants. A modest dose of estradiol can also be applied to inducing enhanced immunity in engineered plants to both bacterial and fungal pathogens.

Cross-Microbial Protection via Priming a Conserved Immune Co-Receptor through Juxtamembrane Phosphorylation in Plants.

Living organisms can be primed for potentiated responses to recurring stresses based on prior experience. However, the molecular basis of immune priming remains elusive in plants that lack adaptive immunity. Here, we report that bacterial challenges can prepare plants for fungal attacks by inducing juxtamembrane phosphorylation of CERK1, the co-receptor indispensable for signaling in response to the fungal elicitor chitin. This phosphorylation is mediated by BAK1, a co-receptor for signaling in response to multiple elicitors. BAK1 interacts with CERK1, and loss of BAK1 reduces priming phosphorylation of CERK1. Juxtamembrane phosphomimetic mutations of CERK1 confer accelerated chitin responses and fortified fungal resistance without triggering constitutive immunity, whereas juxtamembrane phosphodeficient mutations diminish bacteria-induced protection against fungal infection. These findings reveal that crosstalk between cell-surface immune co-receptors can prime defense and demonstrate that juxtamembrane phosphorylation of plant receptor-like kinases can occur independent of kinase activation to place the protein into a prime state.

pJ-Level Energy-Consuming, Low-Voltage Ferroelectric Organic Field-Effect Transistor Memories.

Ferroelectric organic field-effect transistors (Fe-OFETs) have attracted considerable attention because of their promising potential for memory applications, while a critical issue is the large energy consumption mainly caused by a high operating voltage and slow data switching. Here, we employ ultrathin ferroelectric polymer and semiconducting molecular crystals to create low-voltage Fe-OFET memories. Devices require only pJ-level energy consumption. The writing and erasing processes require ∼1.2 and 1.6 pJ/bit, respectively, and the reading energy is ∼1.9 pJ/bit (on state) and ∼0.2 fJ/bit (off state). Thus, our memories consume only <0.1% of the energy required for devices using bulk functional layers. Besides, our devices also exhibit low contact resistance and steep subthreshold swing. Therefore, we provide a strategy that opens up a path for Fe-OFETs toward emerging applications, such as wearable electronics.

Millimeter-Sized Two-Dimensional Molecular Crystalline Semiconductors with Precisely Defined Molecular Layers via Interfacial-Interaction-Modulated Self-Assembly.

The newly emerging field in organic electronics is to control the molecule-substrate interface properties at a two-dimensional (2D) limit via interfacial interactions, which paves the way for driving the molecular assembly for highly ordered 2D molecular crystalline films with precise molecular layers and large-area uniformity. Here, by exploiting molecule-substrate van der Waals (vdW) interactions, we demonstrate thermally induced self-assembly of 2D organic crystalline films exhibiting well-defined molecular layer number over a millimeter-sized area. The organic field-effect transistors (OFETs) with bilayer films show excellent electrical performance with a maximum mobility of 12.8 cm2 V-1 s-1. Moreover, we find that the monolayer films can act as interfacial molecular templates to construct heterojunctions with well-balanced ambipolar transport behaviors. The capability of thermally induced self-assembly of 2D molecular crystalline films with controllable molecular layers and scale-up coverage opens up a way for realizing complicated electronic applications, such as lateral heterojunctions and superlattices.

Temperature dependence of piezo- and ferroelectricity in ultrathin P(VDF-TrFE) films.

The polymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) is highly desirable for piezoelectric and ferroelectric functional applications owing to its considerable electromechanical activity and reliable electrical polarization. However, a clear understanding of the effect of the thermal annealing on the electromechanical behavior and polarization nature of ultrathin crystalline P(VDF-TrFE) films is severely lacking. Here we report the thermally induced structural reorganization, and piezo- and ferroelectric features in the ultrathin P(VDF-TrFE) films. On applying a 40 °C annealing treatment, the polarization-patterned electrostrictive strain reaches the highest value of ∼53.7 pm. Besides, the ultrathin film exhibits a highly ordered antiparallel dipole alignment, the highest local piezoelectric activity, and an improved polarization relaxation time. The optimum film properties are achieved owing to a high degree of polymer chains oriented parallel to the substrate plane. Our results can reveal a promising avenue for nano-electro-mechanical and nano-ferroelectric electronic applications using ultrathin P(VDF-TrFE) films.

Proteomes and Ubiquitylomes Analysis Reveals the Involvement of Ubiquitination in Protein Degradation in Petunias.

Petal senescence is a complex programmed process. It has been demonstrated previously that treatment with ethylene, a plant hormone involved in senescence, can extensively alter transcriptome and proteome profiles in plants. However, little is known regarding the impact of ethylene on posttranslational modification (PTM) or the association between PTM and the proteome. Protein degradation is one of the hallmarks of senescence, and ubiquitination, a major PTM in eukaryotes, plays important roles in protein degradation. In this study, we first obtained reference petunia (Petunia hybrida) transcriptome data via RNA sequencing. Next, we quantitatively investigated the petunia proteome and ubiquitylome and the association between them in petunia corollas following ethylene treatment. In total, 51,799 unigenes, 3,606 proteins, and 2,270 ubiquitination sites were quantified 16 h after ethylene treatment. Treatment with ethylene resulted in 14,448 down-regulated and 6,303 up-regulated unigenes (absolute log2 fold change > 1 and false discovery rate < 0.001), 284 down-regulated and 233 up-regulated proteins, and 320 up-regulated and 127 down-regulated ubiquitination sites using a 1.5-fold threshold (P < 0.05), indicating that global ubiquitination levels increase during ethylene-mediated corolla senescence in petunia. Several putative ubiquitin ligases were up-regulated at the protein and transcription levels. Our results showed that the global proteome and ubiquitylome were negatively correlated and that ubiquitination could be involved in the degradation of proteins during ethylene-mediated corolla senescence in petunia. Ethylene regulates hormone signaling transduction pathways at both the protein and ubiquitination levels in petunia corollas. In addition, our results revealed that ethylene increases the ubiquitination levels of proteins involved in endoplasmic reticulum-associated degradation.