Promoting Oxygen Evolution Electrocatalysis by Coordination Engineering in Cobalt Phosphate.

Understanding the structure-activity correlation is an important prerequisite for the rational design of high-efficiency electrocatalysts at the atomic level. However, the effect of coordination environment on electrocatalytic oxygen evolution reaction (OER) remains enigmatic. In this work, the regulation of proton transfer involved in water oxidation by coordination engineering based on Co3(PO4)2 and CoHPO4 is reported. The HPO4 2- anion has intermediate pKa value between Co(II)-H2O and Co(III)-H2O to be served as an appealing proton-coupled electron transfer (PCET) induction group. From theoretical calculations, the pH-dependent OER properties, deuterium kinetic isotope effects, operando electrochemical impedance spectroscopy (EIS) and Raman studies, the CoHPO4 catalyst beneficially reduces the energy barrier of proton hopping and modulates the formation energy of high-valent Co species, thereby enhancing OER activity. This work demonstrates a promising strategy that involves tuning the local coordination environment to optimize PCET steps and electrocatalytic activities for electrochemical applications. In addition, the designed system offers a motif to understand the structure-efficiency relationship from those amino-acid residue with proton buffer ability in natural photosynthesis.

Correlation of Glycolysis-immune-related Genes in the Follicular Microenvironment of Endometriosis Patients with ART Outcomes.

Endometriosis (EMT) -related infertility has been a challenge for clinical research. Many studies have confirmed that abnormal alterations in the immune microenvironment and glycolysis are instrumental in causing EMT-related infertility. Recently, our research team identified several key glycolysis-immune-related genes in the endometrial cells of EMT patients. This study aimed to further investigate the expression patterns of pyruvate dehydrogenase kinase 3 (PDK3), glypican-3 (GPC3), and alcohol dehydrogenase 6 (ADH6), which are related to glycolysis and immunity, in the follicular microenvironment of infertile patients with EMT using enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) assays. According to the results, compared to the patients with tubal factor infertility, the concentrations of PDK3 and GPC3 were considerably increased in the follicular environment of EMT patients, while ADH6 expression was significantly reduced. The number of oocytes retrieved, the transferable embryo rate, and the cumulative clinical pregnancy rate of EMT patients were significantly reduced, and there was a correlation with the level of PDK3, GPC3, and ADH6 in Follicular Fluid (FF). The area under the receiver operating characteristic (ROC) curve for predicting clinical pregnancy in infertile patients with EMT for PDK3, GPC3, ADH6, and their combination was 0.732, 0.705, 0.855, and 0.879, respectively (P < 0.05). In conclusion, our research indicates that glycolysis-immune-related genes may contribute to infertility in EMT patients through immune infiltration, and disruption of mitochondrial and oocyte functions. The combined detection of PDK3, GPC3, and ADH6 in FF helps to predict clinical pregnancy outcomes in infertile patients with EMT.

The Enhanced Performance of Oxide Thin-Film Transistors Fabricated by a Two-Step Deposition Pressure Process.

It is usually difficult to realize high mobility together with a low threshold voltage and good stability for amorphous oxide thin-film transistors (TFTs). In addition, a low fabrication temperature is preferred in terms of enhancing compatibility with the back end of line of the device. In this study, α-IGZO TFTs were prepared by high-power impulse magnetron sputtering (HiPIMS) at room temperature. The channel was prepared under a two-step deposition pressure process to modulate its electrical properties. X-ray photoelectron spectra revealed that the front-channel has a lower Ga content and a higher oxygen vacancy concentration than the back-channel. This process has the advantage of balancing high mobility and a low threshold voltage of the TFT when compared with a conventional homogeneous channel. It also has a simpler fabrication process than that of a dual active layer comprising heterogeneous materials. The HiPIMS process has the advantage of being a low temperature process for oxide TFTs.

Hypoxia promotes immune escape of pancreatic cancer cells by lncRNA NNT-AS1/METTL3-HuR-mediated ITGB1 m6A modification.

Pancreatic cancer (PC) cell immune escape is a crucial element in PC malignant development. Some previous studies have reported that LncRNA NNT-AS1 played a carcinogenic role in various tumors. However, the effect of lncRNA NNT-AS1 in PC cell immune escape remains unclear. To evaluate PC cell immune escape, PC cells were co-cultured with CD8+ T cells under a hypoxic condition. PC cell proliferation and migration were evaluated using the colony formation assay and transwell assay. CD8+ T cell proliferation and aoptosis were measured using the carboxy fluorescein diacetate succinimidyl ester (CFSE) assay and flow cytometry. The secretion of antitumor cytokines was assessed using enzyme-linked immunosorbent assay (ELISA). The molecular interactions were analyzed using chromatin immunoprecipitation (ChIP), RNA immunoprecipitation (RIP), or dual-luciferase reporter gene assays. A tumor xenograft model was established to evaluate the effects of lncRNA NNT-AS1 on PC in vivo. It was found that lncRNA NNT-AS1 was highly expressed in PC, and its silencing inhibited hypoxia-induced PC cell growth and immune escape in vivo and in vitro. Mechanically, HIF-1α transcriptionally activated NNT-AS1 expression and NNT-AS1 increased ITGB1 stability and expression in a METTL3-HuR dependent manner. ITGB1 overexpression reversed the inhibitory effects of NNT-AS1 knockdown on hypoxia-induced PC cell immune escape. In conclusion, Hypoxia promoted PC cell immune escape through lncRNA NNT-AS1/METTL3-HuR-mediated m6A modification to increase ITGB1 expression, which provided a theoretical foundation and a potential therapeutic target for PC.

A sensory memory processing system with multi-wavelength synaptic-polychromatic light emission for multi-modal information recognition.

Realizing multi-modal information recognition tasks which can process external information efficiently and comprehensively is an urgent requirement in the field of artificial intelligence. However, it remains a challenge to achieve simple structure and high-performance multi-modal recognition demonstrations owing to the complex execution module and separation of memory processing based on the traditional complementary metal oxide semiconductor (CMOS) architecture. Here, we propose an efficient sensory memory processing system (SMPS), which can process sensory information and generate synapse-like and multi-wavelength light-emitting output, realizing diversified utilization of light in information processing and multi-modal information recognition. The SMPS exhibits strong robustness in information encoding/transmission and the capability of visible information display through the multi-level color responses, which can implement the multi-level pain warning process of organisms intuitively. Furthermore, different from the conventional multi-modal information processing system that requires independent and complex circuit modules, the proposed SMPS with unique optical multi-information parallel output can realize efficient multi-modal information recognition of dynamic step frequency and spatial positioning simultaneously with the accuracy of 99.5% and 98.2%, respectively. Therefore, the SMPS proposed in this work with simple component, flexible operation, strong robustness, and highly efficiency is promising for future sensory-neuromorphic photonic systems and interactive artificial intelligence.

Establishment of a novel glycolysis-immune-related diagnosis gene signature for endometriosis by machine learning.

PURPOSE: The objective of this study was to investigate the key glycolysis-related genes linked to immune cell infiltration in endometriosis and to develop a new endometriosis (EMS) predictive model. METHODS: A training set and a test set were created from the Gene Expression Omnibus (GEO) public database. We identified five glycolysis-related genes using least absolute shrinkage and selection operator (LASSO) regression and the random forest method. Then, we developed and tested a prediction model for EMS diagnosis. The CIBERSORT method was used to compare the infiltration of 22 different immune cells. We examined the relationship between key glycolysis-related genes and immune factors in the eutopic endometrium of women with endometriosis. In addition, Gene Ontology (GO)-based semantic similarity and logistic regression model analyses were used to investigate core genes. Reverse real-time quantitative PCR (RT-qPCR) of 5 target genes was analysed. RESULTS: The five glycolysis-related hub genes (CHPF, CITED2, GPC3, PDK3, ADH6) were used to establish a predictive model for EMS. In the training and test sets, the area under the curve (AUC) of the receiver operating characteristic curve (ROC) prediction model was 0.777, 0.824, and 0.774. Additionally, there was a remarkable difference in the immune environment between the EMS and control groups. Eventually, the five target genes were verified by RT-qPCR. CONCLUSION: The glycolysis-immune-based predictive model was established to forecast EMS patients' diagnosis, and a detailed comprehension of the interactions between endometriosis, glycolysis, and the immune system may be vital for the recognition of potential novel therapeutic approaches and targets for EMS patients.

High-performance vertical field-effect organic photovoltaics.

Limited by the inherent energy loss (Eloss) in carrier transport process, the device efficiency of organic solar cells shows inferior to traditional inorganic photovoltaic devices. Generally, molecular design, morphology optimization and interfacial engineering are usually required to alleviate Eloss. Here, vertical field-effect organic photovoltaic (VFEOPV) by integrating an bulk-heterojunction (BHJ) organic photovoltaic (OPV) with vertical field effect transistor (VFET) is invented, in which VFET generates a large, uneven, internal electric field, eliminating the requirement for driving force to dissociate excitons and prevents non-radiative recombination in OPV. In this way, the performance of solar cell can be well controlled by the gate voltage of VFET and the Eloss of VFEOPVs based on J71: ITIC system is dramatically reduced below 0.2 eV, significantly improving power conversion efficiency (PCE) from 10% to 18% under gate voltage of 0.9 V, which only causes negligible additional power consumption (~10-4mJ/cm2). Besides, the device also exhibits multi-functionality including transistor and phototransistors with excellent photodector performance. This work provides a new and general strategy to improve the OPV performance which is compatible with present optimization methods, and can be applied to improve PCE of other types of solar cells such as Perovskite and inorganic solar cells.

Expression and Clinical Significance of HIF-1α in Follicular Fluid and Granulosa Cells in Infertile PCOS Patients.

The present study aimed to determine the clinical predictive significance of HIF-1α in follicular development and assisted reproductive technology (ART). We collected follicular fluid (FF) and granulosa cells (GCs) from PCOS (polycystic ovary syndrome) patients (experimental group) and other patients who were infertile due to tubal factors or male factors (control group) with IVF/ICSI-ET. The localization and expression of HIF-1α in GCs were determined by immunofluorescence staining. HIF-1α protein and mRNA expression were detected by enzyme-linked immunosorbent assay and quantitative real-time PCR, respectively. To clarify the regulation of HIF-1α by TGF-ß1, we added the HIF-1α-specific blocker YC-1 to GCs. The serum AMH, LH, LH/FSH, testosterone, BMI and the number of oocytes retrieved in the PCOS group were significantly higher, while the cleavage rate was significantly lower, than those in the control group. HIF-1α protein was expressed in the cytoplasm of GCs. The expression of HIF-1α protein in the FF of the PCOS group was significantly lower than that in the control group. However, the expression of HIF-1α protein in GCs between the two groups was not significantly different. HIF-1α protein was highly expressed in large FF (follicular diameter ≥ 14 mm). Compared with the control group, the expression of HIF-1α mRNA in GCs of the PCOS group was significantly lower. The results showed a significant positive correlation between HIF-1α and TGF-ß1 expression. We found that both HIF-1α and TGF-ß1 were involved in the development of PCOS follicular development. The mutual regulation of HIF-1α and TGF-ß1 may be one of the important mechanisms of the occurrence and development of PCOS.

Human amniotic epithelial cell-derived extracellular vesicles provide an extracellular matrix-based microenvironment for corneal injury repair.

To study the biological functions and applications of human amniotic epithelial cell-derived extracellular vesicles (hAEC-EVs), the cargos of hAEC-EVs were analyzed using miRNA sequencing and proteomics analysis. The hAECs and hAEC-EVs in this study had specific characteristics. Multi-omics analyses showed that extracellular matrix (ECM) reorganization, inhibition of excessive myofibroblasts, and promotion of target cell adhesion to the ECM were their primary functions. We evaluated the application of hAEC-EVs for corneal alkali burn healing in rabbits and elucidated the fundamental mechanisms. Slit-lamp images revealed that corneal alkali burns induced central epithelial loss, stromal haze, iris, and pupil obscurity in rabbits. Slit-lamp examination and histological findings indicated that hAEC-EVs facilitated re-epithelialization of the cornea after alkali burns, reduced scar formation and promoted the restoration of corneal tissue transparency. Significantly fewer α-SMA-positive myofibroblasts were observed in the hAEC-EV-treated group than the PBS group. HAEC-EVs effectively promoted the proliferation and migration of hCECs and hCSCs in vitro and activated the focal adhesion signaling pathway. We demonstrated that hAEC-EVs were excellent cell-free candidates for the treatment of ECM lesion-based diseases, including corneal alkali burns. HAEC-EVs promoted ECM reorganization and cell adhesion of target tissues or cells via orderly activation of the focal adhesion signaling pathway.

Visual question answering model for fruit tree disease decision-making based on multimodal deep learning.

Visual Question Answering (VQA) about diseases is an essential feature of intelligent management in smart agriculture. Currently, research on fruit tree diseases using deep learning mainly uses single-source data information, such as visible images or spectral data, yielding classification and identification results that cannot be directly used in practical agricultural decision-making. In this study, a VQA model for fruit tree diseases based on multimodal feature fusion was designed. Fusing images and Q&A knowledge of disease management, the model obtains the decision-making answer by querying questions about fruit tree disease images to find relevant disease image regions. The main contributions of this study were as follows: (1) a multimodal bilinear factorized pooling model using Tucker decomposition was proposed to fuse the image features with question features: (2) a deep modular co-attention architecture was explored to simultaneously learn the image and question attention to obtain richer graphical features and interactivity. The experiments showed that the proposed unified model combining the bilinear model and co-attentive learning in a new network architecture obtained 86.36% accuracy in decision-making under the condition of limited data (8,450 images and 4,560k Q&A pairs of data), outperforming existing multimodal methods. The data augmentation is adopted on the training set to avoid overfitting. Ten runs of 10-fold cross-validation are used to report the unbiased performance. The proposed multimodal fusion model achieved friendly interaction and fine-grained identification and decision-making performance. Thus, the model can be widely deployed in intelligent agriculture.

High-Density Reconfigurable Synaptic Transistors Targeting a Minimalist Neural Network.

Enormous synaptic devices are required to build a parallel, precise, and efficient neural computing system. To further improve the energy efficiency of neuromorphic computing, a single high-density synaptic (HDS) device with multiple nonvolatile synaptic states is suggested to reduce the number of synaptic devices in the neural network, although such a powerful synaptic device is rarely demonstrated. Here, a photoisomerism material, namely, diarylethene, whose energy level varies with the wavelength of illumination is first introduced to construct a powerful HDS device. The multiple synaptic states of the HDS device are intrinsically converted under UV-vis regulation and remain nonvolatile after the removal of illumination. More importantly, the conversion is reconfigurable and reversible under different light conditions, and the synaptic characteristics are comprehensively mimicked in each state. Finally, compared with a two-layer multilayer perceptron (MLP) architecture based on static synaptic devices, the HDS device-based architecture reduces the device number by 16 times to achieve a minimalist neural computing structure. The invention of the HDS device opens up a revolutionary paradigm for the establishment of a brain-like network.

A MnO2 nanosheet-assisted ratiometric fluorescence probe based on carbon quantum dots and o-phenylenediamine for determination of 6-mercaptopurine.

A MnO2 nanosheet-assisted ratiometric fluorescence probe based on carbon quantum dots (CQDs) and o-phenylenediamine (OPD) has been developed for the detection of the anticancer drug 6-mercaptopurine (6-MP). CQDs with strong fluorescence are synthesized via the one-step hydrothermal method. MnO2 nanosheets as an oxidase-mimicking nanomaterial directly oxidize OPD into 2,3-diaminophenazine (DAP) which has a fluorescence emission at 570 nm, whereas the fluorescence of CQDs at 445 nm is then reduced by the DAP through the inner filter effect (IFE) under a single excitation wavelength (370 nm). After adding 6-MP, MnO2 nanosheets can be reduced to Mn2+ and lose their oxidase-like property, blocking the IFE with the fluorescence decrease of DAP and fluorescence increase of CQDs. The novel ratiometric fluorescence probe exhibits considerable sensitivity toward 6-MP and linear response is in the 0.46-100.0 µmol L-1 concentration range with the detection limit of 0.14 µmol L-1. Furthermore, the probe shows good selectivity when exposed to a series of interfering other organic and inorganic compounds, and biomolecules and can be applied to the detection for 6-MP in human serum samples and pharmaceutical tablets. Satisfactory recoveries of 6-MP in human serum samples are in the range 96.1-110.9% with the RSD of 1.4 to 3.2%. The amount of 6-MP is successfully estimated as 49.3 mg in pharmaceutical tablet with the RSD of about  2.2%.

High-Performance Organic Synaptic Transistors with an Ultrathin Active Layer for Neuromorphic Computing.

In recent years, much attention has been focused on two-dimensional (2D) material-based synaptic transistor devices because of their inherent advantages of low dimension, simultaneous read-write operation and high efficiency. However, process compatibility and repeatability of these materials are still a big challenge, as well as other issues such as complex transfer process and material selectivity. In this work, synaptic transistors with an ultrathin organic semiconductor layer (down to 7 nm) were obtained by the simple dip-coating process, which exhibited a high current switch ratio up to 106, well off state as low as nearly 10-12 A, and low operation voltage of -3 V. Moreover, various synaptic behaviors were successfully simulated including excitatory postsynaptic current, paired pulse facilitation, long-term potentiation, and long-term depression. More importantly, under ultrathin conditions, excellent memory preservation, and linearity of weight update were obtained because of the enhanced effect of defects and improved controllability of the gate voltage on the ultrathin active layer, which led to a pattern recognition rate up to 85%. This is the first work to demonstrate that the pattern recognition rate, a crucial parameter for neuromorphic computing can be significantly improved by reducing the thickness of the channel layer. Hence, these results not only reveal a simple and effective way to improve plasticity and memory retention of the artificial synapse via thickness modulation but also expand the material selection for the 2D artificial synaptic devices.

Vertical Channel Inorganic/Organic Hybrid Electrochemical Phototransistors with Ultrahigh Responsivity and Fast Response Speed.

Organic phototransistors (OPTs) have attracted enormous attention because of their promising applications in sensing, communication, and imaging. Currently, most OPTs reported utilize field-effect transistors (FETs) with relative long channel length which usually has undesired amplification because of their inherent low transconductance originated from their low channel capacitance, limiting the further improvement of performance. Herein, a vertical channel hybrid electrochemical phototransistor with a nanoscale channel and large transconductance (VECPT) is invented for the first time to achieve ultrahigh photoresponsivity along with a fast response speed. Benefiting from the nanoscale channel length and large transconductance, the photo-generated carriers in channel can be efficiently dissociated, transported, and amplified into the enlarged photocurrent output. Therefore, the devices deliver substantially improved optoelectronic performances with a photoresponsivity as high as ≈2.99 × 107 A/W, detectivity of ≈1.49 × 1013 Jones, and fast-speed response of ≈73 µs under a low voltage of 1 V, which are superior to those of the reported OPTs based on FETs. Moreover, the in situ Kelvin probe microscopy is performed to characterize the surface potential of device systems for better elucidating the photosensing mechanism. Furthermore, taking advantage of its excellent optoelectronic performance, an ultraviolet light monitoring system is constructed by integrating VECPT with a light-emitting diode, which also shows the real-time, high-sensitive, and controllable photoresponse threshold properties. All these results demonstrate the great potential of these electrochemical phototransistors and provide valuable insights into the design of the nanoscale channel length device system for high-performance photodetection.

High-Performance Vertical Organic Phototransistors Enhanced by Ferroelectrics.

Organic phototransistors with high sensitivity and responsivity to light irradiance have great potential applications in national defense, meteorology, industrial manufacturing, and medical security. However, undesired dark current and photoresponsivity limit their practical applications. Here, a novel vertical organic phototransistor combined with ferroelectric materials is developed. The device structure has nanometer channel length, which can effectively separate photogenerated carriers and reduce the probability of carrier recombination and defect scattering, thus improving the device performance of phototransistors. Moreover, by inserting the poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) ferroelectric layer, the Schottky barrier at the interface between the semiconductor and source can be adjusted by the polarization of the external electric field, which can effectively reduce the dark current of the phototransistor to further improve the device performance. Therefore, our phototransistors exhibit a high photoresponsivity of more than 5.7 × 105A/W, an outstanding detectivity of 1.15 × 1018 Jones, and an excellent photosensitivity of 5 × 107 under 760 nm light illumination, which are better than those of conventional lateral organic phototransistors. This work provides a new approach for the development of high-performance phototransistors, which opens a new pathway for organic phototransistors in practical application.

High-Performance Organic Electrochemical Transistors with Nanoscale Channel Length and Their Application to Artificial Synapse.

Organic electrochemical transistors (OECTs) have attracted considerable interests for various applications ranging from biosensors to digital logic circuits and artificial synapses. However, the majority of reported OECTs utilize large channel length up to several or several tens of micrometers, which limits the device performance and leads to low transistor densities. Here, we demonstrate a new design of vertical OECT architecture with a nanoscale channel length down to ∼100 nm. The devices exhibit a high on-state current of over 20 mA under a low bias voltage of 0.5 V, a fast transient response of less than 300 µs, and an extraordinary transconductance up to 68.88 mS, representing a record-high value for OECTs. The excellent electrical performance is attributed to the novel structure with a nanoscale channel length defined by the channel material thickness, which is intrinsically different from that of conventional OECTs with the channel length limited by the lithography resolution. Owing to the low thermal budget, we fabricate flexible devices on a flexible substrate, which exhibit unprecedented endurance characteristics and mechanical robustness after 1000 blending cycles. Furthermore, the proposed device is capable of mimicking biological inhibitory synapses for application in intelligent artificial neural networks. Our work not only pushes the performance limit of OECTs but also opens up a new design of OECTs for high-performance biosensors, digital logic, and neuromorphic devices.

High-performance Nonvolatile Organic Photoelectronic Transistor Memory Based on Bulk Heterojunction Structure.

Depending on the storage mechanisms, organic field-effect transistor (OFET) memory is usually divided into floating gate memory, ferroelectric memory, and polymer-electret-based memory. In this work, a new type of nonvolatile OFET memory is proposed by simply blending a p-type semiconductor and a n-type semiconductor without using an extra trapping layer. The results show that the memory window can be effectively modulated by the dopant concentration of the n-type semiconductor. With the addition of a 5% n-type semiconductor, blending devices exhibit a large memory window up to 57.7 V, an ON/OFF current ratio (ION/IOFF) ≈ 105, and a charge retention time of over 10 years, which is comparable or even better than those of most of the traditional OFET memories. The discontinuous n-type semiconductor is set as a charge-trapping center for charge storage due to the quantum well-like organic heterojunctions. The generalization of this method is also investigated in other organic systems. Moreover, the blend devices are also applied to optical memory and show multilevel optical storage, which are further scaled up to 8 × 8 array to map up two-dimensional (2D) optical images with long-term retention and reprogramming characteristic. The results reveal that the novel system design has great potential application in the field of digital image memory and photoelectronic system.

Upregulation of hsa_circ_0007874 suppresses the progression of ovarian cancer by regulating the miR-760/SOCS3 pathway.

Ovarian cancer (OVA) is a fatal and common malignancy in women worldwide. Circular RNAs (circRNAs) consist of a family of circular endogenous RNAs generated by selective splicing, and they are involved in many diseases. Previous studies reported that hsa_circ_0007874 is aberrantly expressed in cancer and functions in tumorigenesis. While the hsa_circ_0007874 role in OVA is unclear. Here, we detected the hsa_circ_0007874 expression in OVA cell lines using Rt-qPCR. Hsa_circ_0007874 subcellular localization was confirmed by fluorescence in situ hybridization. The relationship between hsa_circ_0007874, microRNAs (miRNAs), and relative protein levels was assessed using the luciferase reporter assays. Results verified that hsa_circ_0007874 is downregulated in OVA cell lines. hsa_circ_0007874 overexpression decreased the OVA cell migration and proliferation in vitro and in vivo. Bioinformatics and luciferase reporter assays confirmed that miR-760 and SOCS3 are the downstream targets of hsa_circ_0007874. Downregulation of SOCS3 or miR-760 overexpression restored the migration and proliferation ability of SKOV3 or A2780 cells overexpressing hsa_circ_0007874. Downregulation of SOCS3 restored the proliferation and migration in miR-760 knockdown SKOV3 and A2780 cells. In summary, the data suggest that hsa_circ_0007874 acts as a tumor suppressor by regulating the miR-760/SOCS3 axis, highlighting its potential as an effective therapeutic target for OVA.

All-metal oxide synaptic transistor with modulatable plasticity.

The artificial neural system has attracted tremendous attention in the field of artificial intelligence due to operate mode of parallel computation which is superior to traditional Von Neumann computers in processing complex sensory data and real-time situations with extremely low power dissipation. Remarkable progress has been made in the hardware-based electric-double-layer synaptic transistors as its modulation by ion movement is similar to biological synapse for the past few years. Unfortunately, long-term potentiation (LTP) timescale is still a big challenge in hardware-based electric-double-layer synaptic transistors which is essential to processing capacity and memory formation. Meanwhile, the effect of ion concentration on the synaptic plasticity has rarely been reported. Here, a solid state electrolyte-gated transistor using Ta2O5 as dielectric layer with unique ionic composition was demonstrated and the regulation of synaptic weight was realized by changing ion concentration. Both the potentiation and depression of synaptic weight such as excitatory post-synaptic current, inhibitory response (IPSC), paired pulse facilitation as well as LTP were successfully simulated. More importantly, oxygen vacancy content was tuned for the first time to modulate synaptic plasticity by varying film thickness and gas ratio, through which the intensity and duration of memory were enhanced with appropriate vacancy concentration. It indicated that appropriate vacancy concentration avoided the effects of internal electric field induced by ion excess, leading to a long-term memory. These results reveal a promising path to improve memory capacity of artificial synapse via ion modulation.

Synaptic Transistor Capable of Accelerated Learning Induced by Temperature-Facilitated Modulation of Synaptic Plasticity.

Neuromorphic computation, which emulates the signal process of the human brain, is considered to be a feasible way for future computation. Realization of dynamic modulation of synaptic plasticity and accelerated learning, which could improve the processing capacity and learning ability of artificial synaptic devices, is considered to further improve energy efficiency of neuromorphic computation. Nevertheless, realization of dynamic regulation of synaptic weight without an external regular terminal and the method that could endow artificial synaptic devices with the ability to modulate learning speed have rarely been reported. Furthermore, finding suitable materials to fully mimic the response of photoelectric stimulation is still challenging for photoelectric synapses. Here, a floating gate synaptic transistor based on an L-type ligand-modified all-inorganic CsPbBr3 perovskite quantum dots is demonstrated. This work provides first clear experimental evidence that the synaptic plasticity can be dynamically regulated by changing the waveforms of action potential and the environment temperature and both of these parameters originate from and are crucial in higher organisms. Moreover, benefiting from the excellent photoelectric properties and stability of quantum dots, a temperature-facilitated learning process is illustrated by the classical conditioning experiment with and without illumination, and the mechanism of synaptic plasticity is also demonstrated. This work offers a feasible way to realize dynamic modulation of synaptic weight and accelerating the learning process of artificial synapses, which showed great potential in the reduction of energy consumption and improvement of efficiency of future neuromorphic computing.