Hardware implementation of artificial synaptic devices that emulate the functions of biological synapses is inspired by the biological neuromorphic system and has drawn considerable interest. Here, a ...three‐terminal ferrite synaptic device based on a topotactic phase transition between crystalline phases is presented. The electrolyte‐gating‐controlled topotactic phase transformation between brownmillerite SrFeO2.5 and perovskite SrFeO3−δ is confirmed from the examination of the crystal and electronic structure. A synaptic transistor with electrolyte‐gated ferrite films by harnessing gate‐controllable multilevel conduction states, which originate from many distinct oxygen‐deficient perovskite structures of SrFeOx induced by topotactic phase transformation, is successfully constructed. This three‐terminal artificial synapse can mimic important synaptic functions, such as synaptic plasticity and spike‐timing‐dependent plasticity. Simulations of a neural network consisting of ferrite synaptic transistors indicate that the system offers high classification accuracy. These results provide insight into the potential application of advanced topotactic phase transformation materials for designing artificial synapses with high performance.
A ferrite synaptic transistor with topotactic transformation is presented. The electrolyte‐gating‐controlled topotactic phase transformation between the brownmillerite SrFeO2.5 and perovskite SrFeO3−δ is confirmed by the crystal and electronic structure measurements. This ferrite synaptic transistor can mimic important synaptic functions such as synaptic plasticity and spike‐timing‐dependent plasticity.
The challenges of developing neuromorphic vision systems inspired by the human eye come not only from how to recreate the flexibility, sophistication, and adaptability of animal systems, but also how ...to do so with computational efficiency and elegance. Similar to biological systems, these neuromorphic circuits integrate functions of image sensing, memory and processing into the device, and process continuous analog brightness signal in real-time. High-integration, flexibility and ultra-sensitivity are essential for practical artificial vision systems that attempt to emulate biological processing. Here, we present a flexible optoelectronic sensor array of 1024 pixels using a combination of carbon nanotubes and perovskite quantum dots as active materials for an efficient neuromorphic vision system. The device has an extraordinary sensitivity to light with a responsivity of 5.1 × 10
A/W and a specific detectivity of 2 × 10
Jones, and demonstrates neuromorphic reinforcement learning by training the sensor array with a weak light pulse of 1 μW/cm
.
Summary
Both sugar and the hormone gibberellin (GA) are essential for anther‐enclosed pollen development and thus for plant productivity in flowering plants. Arabidopsis (Arabidopsis thaliana) ...AtSWEET13 and AtSWEET14, which are expressed in anthers and associated with seed yield, transport both sucrose and GA. However, it is still unclear which substrate transported by them directly affects anther development and seed yield.
Histochemical staining, cross‐sectioning and microscopy imaging techniques were used to investigate and interpret the phenotypes of the atsweet13;14 double mutant during anther development. Genetic complementation of atsweet13;14 using AtSWEET9, which transports sucrose but not GA, and the GA transporter AtNPF3.1, respectively, was conducted to test the substrate preference relevant to the biological process.
The loss of both AtSWEET13 and AtSWEET14 resulted in reduced pollen viability and therefore decreased pollen germination. AtSWEET9 fully rescued the defects in pollen viability and germination of atsweet13;14, whereas AtNPF3.1 failed to do so, indicating that AtSWEET13/14‐mediated sucrose rather than GA is essential for pollen fertility.
AtSWEET13 and AtSWEET14 function mainly at the anther wall during late anther development stages, and they probably are responsible for sucrose efflux into locules to support pollen development to maturation, which is vital for subsequent pollen viability and germination.
Aqueous Zn batteries that provide a synergistic integration of absolute safety and high energy density have been considered as highly promising energy‐storage systems for powering electronics. ...Despite the rapid progress made in developing high‐performance cathodes and electrolytes, the underestimated but non‐negligible dendrites of Zn anode have been observed to shorten battery lifespan. Herein, this dendrite issue in Zn anodes, with regard to fundamentals, protection strategies, characterization techniques, and theoretical simulations, is systematically discussed. An overall comparison between the Zn dendrite and its Li and Al counterparts, to highlight their differences in both origin and topology, is given. Subsequently, in‐depth clarifications of the specific influence factors of Zn dendrites, including the accumulation effect and the cathode loading mass (a distinct factor for laboratory studies and practical applications) are presented. Recent advances in Zn dendrite protection are then comprehensively summarized and categorized to generate an overview of respective superiorities and limitations of various strategies. Accordingly, theoretical computations and advanced characterization approaches are introduced as mechanism guidelines and measurement criteria for dendrite suppression, respectively. The concluding section emphasizes future challenges in addressing the Zn dendrite issue and potential approaches to further promoting the lifespan of Zn batteries.
Zinc‐based batteries demonstrate both intrinsic safety and high energy density compared with other metal batteries. Nevertheless, zinc‐dendrite issues such as special morphology and nucleation require unique protections, which develop rapidly and need further improvement. The remaining challenges are discussed and the future directions, i.e., dynamic contact, atomic‐level ionic flow mediation, dendrite protection under high depth of discharge, etc., are proposed.
Abstract
The practical application of room-temperature Na-S batteries is hindered by the low sulfur utilization, inadequate rate capability and poor cycling performance. To circumvent these issues, ...here, we propose an electrocatalyst composite material comprising of N-doped nanocarbon and Fe
3
N. The multilayered porous network of the carbon accommodates large amounts of sulfur, decreases the detrimental effect of volume expansion, and stabilizes the electrodes structure during cycling. Experimental and theoretical results testify the Fe
3
N affinity to sodium polysulfides via Na-N and Fe-S bonds, leading to strong adsorption and fast dissociation of sodium polysulfides. With a sulfur content of 85 wt.%, the positive electrode tested at room-temperature in non-aqueous Na metal coin cell configuration delivers a reversible capacity of about 1165 mA h g
−1
at 167.5 mA g
−1
, satisfactory rate capability and stable capacity of about 696 mA h g
−1
for 2800 cycles at 8375 mA g
−1
.
For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable ...copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction. Under very harsh working conditions, the ceria nanorods suffered a partial sintering, on which the 2D and 3D copper clusters were formed. This partially sintered catalyst exhibits unmatched activity and excellent durability at high temperature. The interaction between the copper and ceria ensures the copper clusters stably anchored on the surface of ceria. Abundant in situ generated and consumed surface oxygen vacancies form synergistic effect with adjacent copper clusters to promote the reaction process. This work investigates the structure-function relation of the catalyst with sintered and inhomogeneous structure and explores the potential application of the sintered catalyst in C1 chemistry.
Dormant
Bacillales
and
Clostridiales
spores begin to grow when small molecules (germinants) trigger germination, potentially leading to food spoilage or disease. Germination-specific proteins sense ...germinants, transport small molecules, and hydrolyze specific bonds in cortex peptidoglycan and specific proteins. Major events in germination include (
a
) germinant sensing; (
b
) commitment to germinate; (
c
) release of spores' depot of dipicolinic acid (DPA); (
d
) hydrolysis of spores' peptidoglycan cortex; and (
e
) spore core swelling and water uptake, cell wall peptidoglycan remodeling, and restoration of core protein and inner spore membrane lipid mobility. Germination is similar between
Bacillales
and
Clostridiales
, but some species differ in how germinants are sensed and how cortex hydrolysis and DPA release are triggered. Despite detailed knowledge of the proteins and signal transduction pathways involved in germination, precisely what some germination proteins do and how they do it remain unclear.
Mesenchymal stem cells (MSCs; also referred to as mesenchymal stromal cells) have attracted much attention for their ability to regulate inflammatory processes. Their therapeutic potential is ...currently being investigated in various degenerative and inflammatory disorders such as Crohn's disease, graft-versus-host disease, diabetic nephropathy and organ fibrosis. The mechanisms by which MSCs exert their therapeutic effects are multifaceted, but in general, these cells are thought to enable damaged tissues to form a balanced inflammatory and regenerative microenvironment in the presence of vigorous inflammation. Studies over the past few years have demonstrated that when exposed to an inflammatory environment, MSCs can orchestrate local and systemic innate and adaptive immune responses through the release of various mediators, including immunosuppressive molecules, growth factors, exosomes, chemokines, complement components and various metabolites. Interestingly, even nonviable MSCs can exert beneficial effects, with apoptotic MSCs showing immunosuppressive functions in vivo. Because the immunomodulatory capabilities of MSCs are not constitutive but rather are licensed by inflammatory cytokines, the net outcomes of MSC activation might vary depending on the levels and the types of inflammation within the residing tissues. Here, we review current understanding of the immunomodulatory mechanisms of MSCs and the issues related to their therapeutic applications.
Data on the associations between esophageal histological lesions and risk of esophageal squamous cell carcinoma (ESCC) in general populations are limited. We aimed to investigate these associations ...in a large Chinese general population to inform future Chinese ESCC screening guidelines.
We performed endoscopic screening of 21,111 participants aged 40-69 years from 3 high-risk areas of China in 2005-2009, and followed the cohort through 2016. Cumulative incidence and mortality rates of ESCC were calculated by baseline histological diagnosis, and hazard ratios of ESCC, overall and by age and sex, were assessed using the Cox proportional hazards models.
We identified 143 new ESCC cases (0.68%) and 62 ESCC deaths (0.29%) during a median follow-up of 8.5 years. Increasing grades of squamous dysplasia were associated with the increasing risk of ESCC incidence and mortality. The cumulative ESCC incidence rates for severe dysplasia/carcinoma in situ, moderate dysplasia (MD), and mild dysplasia were 15.5%, 4.5%, and 1.4%, respectively. Older individuals (50-69 years) had 3.1 times higher ESCC incidence than younger individuals (40-49 years), and men had 2.4 times higher ESCC incidence than women.
This study confirmed that increasing grades of squamous dysplasia are associated with increasing risk of ESCC and that severe dysplasia and carcinoma in situ require clinical treatment. This study suggests that in high-risk areas of China, patients with endoscopically worrisome MD should also receive therapy, the first screening can be postponed to 50 years, and endoscopic surveillance intervals for unremarkable MD and mild dysplasia can be lengthened to 3 and 5 years, respectively.
As a rapidly growing family of 2D transition metal carbides and nitrides, MXenes are recognized as promising materials for the development of future electronics and optoelectronics. So far, the ...reported patterning methods for MXene films lack efficiency, resolution, and compatibility, resulting in limited device integration and performance. Here, a high‐performance MXene image sensor array fabricated by a wafer‐scale combination patterning method of an MXene film is reported. This method combines MXene centrifugation, spin‐coating, photolithography, and dry‐etching and is highly compatible with mainstream semiconductor processing, with a resolution up to 2 µm, which is at least 100 times higher than other large‐area patterning methods reported previously. As a result, a high‐density integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a detectivity of 7.73 × 1014 Jones and a light–dark current ratio (Ilight/Idark) of 6.22 × 106, which is the ultrahigh value among all reported MXene‐based photodetectors, is fabricated. This patterning technique paves a way for large‐scale high‐performance MXetronics compatible with mainstream semiconductor processes.
MXenes are promising for future electronics and optoelectronics; however, previously reported patterning methods lack efficiency, resolution, and compatibility with mainstream semiconductor processing. Here, a wafer‐scale combination patterning method with a resolution up to the micrometer scale is developed, resulting in an integrated array of 1024‐pixel Ti3C2Tx/Si photodetectors with a record‐high detectivity of 7.73 × 1014 Jones.
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