Bioinspired artificial haptic neuron system has received much attention in the booming artificial intelligence industry for its broad range of high‐impact applications such as personal healthcare ...monitoring, electronic skins, and human–machine interfaces. An artificial haptic neuron system is designed by integrating a piezoresistive sensor and a Nafion‐based memristor for the first time in this paper. The piezoresistive sensor serves as a sensory receptor to transform mechanical stimuli into electric signals, and the Nafion‐based memristor serves as the synapse to further process the information. The pyramid‐structured sensor exhibits excellent sensitivity (6.7 × 107 kPa−1 in 1–5 kPa and 3.8 × 105 kPa−1 in 5–50 kPa) and durability (>7000 cycles), while the memristor realizes fundamental synaptic functions under low power consumption (10–200 pJ) and remains stable for over 104 consecutive tests. The integrated system can detect tactile stimuli encoded with temporal information, such as the count, frequency, duration and speed of the external force. As a proof‐of‐concept, English characters recognition with high accuracy can be achieved on the system under a supervised learning method. This work shows promising potential in bioinspired sensing systems owing to the high performance, excellent durability, and simple fabrication procedure.
An artificial haptic neuron system is designed by integrating a piezoresistive sensor and a Nafion‐based memristor for the first time. The pyramid‐structured sensor exhibits excellent sensitivity and durability, while the memristor realizes fundamental synaptic functions under low power consumption and remains stable for over 104 consecutive tests. The integrated system can detect tactile stimuli encoded with temporal information.
Xenotransplantation is a promising strategy to alleviate the shortage of organs for human transplantation. In addition to the concerns about pig-to-human immunological compatibility, the risk of ...cross-species transmission of porcine endogenous retroviruses (PERVs) has impeded the clinical application of this approach. We previously demonstrated the feasibility of inactivating PERV activity in an immortalized pig cell line. We now confirm that PERVs infect human cells, and we observe the horizontal transfer of PERVs among human cells. Using CRISPR-Cas9, we inactivated all of the PERVs in a porcine primary cell line and generated PERV-inactivated pigs via somatic cell nuclear transfer. Our study highlights the value of PERV inactivation to prevent cross-species viral transmission and demonstrates the successful production of PERV-inactivated animals to address the safety concern in clinical xenotransplantation.
Recently, conductive metal−organic frameworks (MOFs) as the active material have provided broad prospects for electronic device application. The positioning technologies for MOFs enable the ...fabrication of novel microstructures, which can modulate the morphology of the material and tune the properties for the targeted application. Herein, a template‐method is used to synthesize the hierarchical structure of MOF hybrid array (MHA) on copper mesh (MHA@Mesh) for flexible sensor. Finite element method (FEM) results indicate that the 3D hierarchical MHA@Mesh can mimic the micro/nanoscale structure of human skin, which enables an interlocking contact. MHA@Mesh‐based flexible sensor presents rapid response rate (<1 ms) and high sensitivity (up to 307 kPa−1) which is 20 times higher than that of MHA@Foil‐based sensor (15 kPa−1). The flexible pressure device could be applied to monitor the finger motion and human pulses. Moreover, the music recognition can be performed by integrating the MOFs hardware sensors with machine learning algorithms. Overall, this design concept of 3D hierarchical microarray structures demonstrates potential in the fields of wearable technologies and human–machine interfaces.
A metal–organic framework hybrid array on a copper mesh with a hierarchical structure is synthesized and employed as the active layer of a resistive tactile sensor. Finite element method study reveals the mechanism of pressure‐dependent contact area modulation. The sensor can monitor biophysical signals and realize music recognition owing to the high sensitivity and stability.
During the lockdown due to SARS-CoV-2 (coronavirus lockdown), there has been a tremendous increase in the number of students taking online courses. Few studies, however, have examined the individual ...dispositions that influence self-regulated online learning during the coronavirus lockdown. To address this gap, the present study explored the ineffectiveness of online learning and examined how it can be predicted by self-regulated online learning and participants' procrastination disposition. Data of 433 participants were collected and subjected to confirmatory factor analysis with structural equation modeling. The results indicated that procrastination is negatively related to 6 sub-constructs of self-regulated online learning: task strategy, mood adjustment, self-evaluation, environmental structure, time management, and help-seeking. These sub-constructs were negatively related to the learners' perceived ineffectiveness of online learning. However, the relationship between perceived learning ineffectiveness and environmental structure or help-seeking was weaker than that with task strategy or mood adjustment, indicating that the latter two subtypes of self-regulated online learning should be considered before students engage in online learning.
•Procrastination, self-regulated online learning (SRL) and ineffectiveness on COVID-19•Procrastination was negatively related to all sub-constructs of SRL.•SRL was negatively associated with perceived ineffectiveness of online learning.•Mood adjustment had the most negative relationship with learning ineffectiveness.
Trifluoromethylation‐based difunctionalization of alkenes provides a step‐economical route to CF3‐containing polyfunctionalized organics. New and scalable processes are highly desired in this field. ...Here, we report a simple and environmentally benign method for olefinic thiocyanotrifluoromethylation. Using PhICF3Cl as unique CF3 agent and NaSCN as the SCN source, the difunctionalization of alkenes selectively occurs on water at ambient condition. Mechanism studies suggest a radical process in which SCN anion is proposed to act as not only reductive initiator but also S‐nucleophile. All tested reactions are compatible with mono‐, di‐, tri‐, and tetra‐substituted alkenes and with high functional group tolerance. This method is also suitable for the selenocyanotrifluoromethylation of alkenes. Therefore, a sustainable platform has been established to synthesize valuable β‐trifluoromethylated thio(seleno)cyanates in a green way.
A sustainable platform has been established to synthesize valuable β‐trifluoromethylated thio(seleno)cyanates in a green way. Using PhICF3Cl as unique CF3 agent and NaSCN as the SCN source, the difunctionalization of alkenes selectively occurs on water at ambient condition. Mechanism studies suggest a radical process in which SCN anion is proposed to act as not only reductive initiator but also S‐nucleophile. This method is also suitable for the selenocyanotrifluoromethylation of alkenes.
Carbon capture is essential for mitigating carbon dioxide emissions. Compared to conventional chemical scrubbing, electrochemically mediated carbon capture utilizing redox-active sorbents such as ...quinones is emerging as a more versatile and economical alternative. However, the practicality of such systems is hindered by the requirement of toxic, flammable organic electrolytes or often costly ionic liquids. Herein, we demonstrate that rationally designed aqueous electrolytes with high salt concentration can effectively resolve the incompatibility between aqueous environments and quinone electrochemistry for carbon capture, eliminating the safety, toxicity, and at least partially the cost concerns in previous studies. Salt-concentrated aqueous media also offer distinct advantages including extended electrochemical window, high carbon dioxide activity, significantly reduced evaporative loss and material dissolution, and importantly, greatly suppressed competing reactions including under simulated flue gas. Correspondingly, we achieve continuous carbon capture-release operations with outstanding capacity, stability, efficiency and electrokinetics, advancing electrochemical carbon separation further towards practical applications.
Polymer membranes with ultrahigh CO2 permeabilities and high selectivities are needed to address some of the critical separation challenges related to energy and the environment, especially in ...natural gas purification and postcombustion carbon capture. However, very few solution‐processable, linear polymers are known today that access these types of characteristics, and all of the known structures achieve their separation performance through the design of rigid backbone chemistries that concomitantly increase chain stiffness and interchain spacing, thereby resulting in ultramicroporosity in solid‐state chain‐entangled films. Herein, the separation performance of a porous polymer obtained via ring‐opening metathesis polymerization is reported, which possesses a flexible backbone with rigid, fluorinated side chains. This polymer exhibits ultrahigh CO2 permeability (>21 000 Barrer) and exceptional plasticization resistance (CO2 plasticization pressure > 51 bar). Compared to traditional polymers of intrinsic microporosity, the rate of physical aging is slower, especially for gases with small effective diameters (i.e., He, H2, and O2). This structural design strategy, coupled with studies on fluorination, demonstrates a generalizable approach to create new polymers with flexible backbones and pore‐forming side chains that have unexplored promise for small‐molecule separations.
A porous polymer featuring a flexible backbone and rigid, fluorinated side chains is prepared via ring‐opening metathesis polymerization. This polymer exhibits ultrahigh CO2 permeability (>21 000 Barrer) and exceptional plasticization resistance (CO2‐induced plasticization pressure > 51 bar). By generating ultramicroporosity through predesigned side chains instead of the polymer backbone, a promising new design strategy is presented for gas‐separation membranes.
Nanocomposites containing Ni or Co or NiCo alloy and nitrogen‐doped carbon with diverse ratios have been prepared and utilized as active elements in supercapacitors. The atomic contents of nitrogen, ...nickel, and cobalt have been adjusted by the supplement amount of Ni and Co salts. In virtue of the excellent surface groups and rich redox active sites, the NC/NiCo active materials exhibit superior electrochemical charge‐storage performances. Among these as‐prepared active electrode materials, the NC/NiCo1/1 electrode performs better than other bimetallic/carbon electrodes and pristine metal/carbon electrodes. Several characterization methods, kinetic analyses, and nitrogen‐supplement strategies determine the specific reason for this phenomenon. As a result, the better performance can be ascribed to a combination of factors including the high surface area and nitrogen content, proper Co/Ni ratio, and relatively low average pore size. The NC/NiCo electrode delivers a maximum capacity of 300.5 C g−1 and superior capacity retention of 92.30% after 3000 unceasing charge‐discharge cycles. After assembling it into the battery‐supercapacitor hybrid device, a high energy density of 26.6 Wh kg−1 (at 412 W kg−1) is achieved, comparable to the recent reports. Furthermore, this device can also power four light‐emitting‐diode (LED) demos, suggesting the potential practicability of these N‐doped carbon compositing with bimetallic materials.
The core‐shell materials of nitrogen‐doped carbon compositing with the bimetallic NiCo alloy have been fabricated and documented as supercapacitors’ active electrodes, and the structure‐performance relations have also been investigated.
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