Gate-Controlled Neuromorphic Functional Transition in an Electrochemical Graphene Transistor.

Neuromorphic devices have attracted significant attention as potential building blocks for the next generation of computing technologies owing to their ability to emulate the functionalities of biological nervous systems. The essential components in artificial neural networks such as synapses and neurons are predominantly implemented by dedicated devices with specific functionalities. In this work, we present a gate-controlled transition of neuromorphic functions between artificial neurons and synapses in monolayer graphene transistors that can be employed as memtransistors or synaptic transistors as required. By harnessing the reliability of reversible electrochemical reactions between carbon atoms and hydrogen ions, we can effectively manipulate the electric conductivity of graphene transistors, resulting in a high on/off resistance ratio, a well-defined set/reset voltage, and a prolonged retention time. Overall, the on-demand switching of neuromorphic functions in a single graphene transistor provides a promising opportunity for developing adaptive neural networks for the upcoming era of artificial intelligence and machine learning.

Fabrication-induced even-odd discrepancy of magnetotransport in few-layer MnBi2Te4.

The van der Waals antiferromagnetic topological insulator MnBi2Te4 represents a promising platform for exploring the layer-dependent magnetism and topological states of matter. Recently observed discrepancies between magnetic and transport properties have aroused controversies concerning the topological nature of MnBi2Te4 in the ground state. In this article, we demonstrate that fabrication can induce mismatched even-odd layer dependent magnetotransport in few-layer MnBi2Te4. We perform a comprehensive study of the magnetotransport properties in 6- and 7-septuple-layer MnBi2Te4, and reveal that both even- and odd-number-layer device can show zero Hall plateau phenomena in zero magnetic field. Importantly, a statistical survey of the optical contrast in more than 200 MnBi2Te4 flakes reveals that the zero Hall plateau in odd-number-layer devices arises from the reduction of the effective thickness during the fabrication, a factor that was rarely noticed in previous studies of 2D materials. Our finding not only provides an explanation to the controversies regarding the discrepancy of the even-odd layer dependent magnetotransport in MnBi2Te4, but also highlights the critical issues concerning the fabrication and characterization of 2D material devices.

Core-shell structure dependent reactivity of Fe@Fe2O3 nanowires on aerobic degradation of 4-chlorophenol.

In this study, core-shell Fe@Fe2O3 nanowires with different iron oxide shell thickness were synthesized through tuning water-aging time after the reduction of ferric ions with sodium borohydride without any stirring. We found that these Fe@Fe2O3 nanowires exhibited interesting core-shell structure dependent reactivity on the aerobic degradation of 4-chlorophenol. Characterization results revealed that the core-shell structure dependent aerobic oxidative reactivity of Fe@Fe2O3 nanowires was arisen from the combined effects of incrassated iron oxide shell and more surface bound ferrous ions on amorphous iron oxide shell formed during the water-aging process. The incrassated iron oxide shell would gradually block the outward electron transfer from iron core for the subsequent two-electron molecular oxygen activation, but more surface bound ferrous ions on iron oxide shell with prolonging aging time could favor the single-electron molecular oxygen activation, which was confirmed by electron spin resonance spectroscopy with spin trap technique. The mineralization of 4-chlorophenol was monitored by total organic carbon measurement and the oxidative degradation intermediates were analyzed by gas chromatography-mass spectrometry. This study provides new physical insight on the molecular oxygen activation mechanism of nanoscale zerovalent iron and its application on aerobic pollutant removal.

In vitro anti-inflammatory effects of beta-carboline alkaloids, isolated from Picrasma quassioides, through inhibition of the iNOS pathway.

In our previous study, fourty-eight compounds have been isolated and identified from the roots of Picrasma quassioides, which have been widely used as a traditional Chinese medicine for clearing heat and for detoxification as described in the Chinese Pharmacopoeia. ß-Carboline alkaloids are commonly considered as main active constituents of P. quassioides, but the molecular mechanism remains yet unknown. In the present paper, one new ß-carboline alkaloid together with two known ß-carboline alkaloids have been investigated for their anti-inflammatory effect and mechanism of action in cultured macrophage RAW 264.7 cells. Griess assay was used to evaluate the inhibitory effect on the overproduction of nitric oxide. ELISA was used to determine the level of proinflammatory cytokines including TNF-α and IL-6. The inhibitory effect on the enzymatic activity of COX-2 and inducible nitric oxide synthase were tested by colorimetric and fluorimetric methods, respectively. Western blot was used to detect the expression of inducible nitric oxide synthase and COX-2. All three ß-carboline alkaloids suppressed LPS-stimulated nitric oxide production and proinflammatory cytokines secretion, including TNF-α and IL-6 in a dose-dependent manner. They also strongly inhibited the expression of inducible nitric oxide synthase and inducible nitric oxide synthase enzymatic activity, whereas the expression of COX-2 and COX-2 enzymatic activity were not affected. These results indicated that potent inhibition of nitric oxide, TNF-α, and IL-6, but not COX-2 expression and COX-2 activity, might constitute the anti-inflammatory mechanism of ß-carboline alkaloids. ß-Carboline alkaloids suppressed the overproduction of nitric oxide through downregulation of inducible nitric oxide synthase expression and inducible nitric oxide synthase enzymatic activity in an LPS-stimulated macrophage.

Study on public acceptance of decommissioning of a uranium mining and metallurgy facility in Hunan Province.

The decommissioning of uranium mining and metallurgy facilities involves sensitive issues of the local government and the public, which is related to the vital interests of the surrounding residents. Improper disposal may lead to negative emotions among the public and affect the process of uranium mining and metallurgy facilities decommissioning projects. In order to explore the acceptance of uranium mining and metallurgy decommissioning projects by nearby residents and its influencing factors, a hypothesis model of influencing factors of public acceptance was constructed through literature survey. Taking the public around a uranium mining and metallurgy in Hunan Province as an example, a questionnaire survey was carried out. Using the AMOS21.0 tool, the fitting test of the structural equation model was carried out on 506 valid sample data and the hypothetical model, and the key factors affecting the public acceptance of the uranium mining and metallurgy decommissioning project were analyzed. The findings show that public perceived risk (-0.28), familiarity (0.26) and trust (0.175) are key factors influencing acceptance. The research results provide a methodological basis for improving the public acceptance of uranium mining and metallurgy decommissioning projects.

Bronchoscopic airway clearance therapy for acute exacerbations of bronchiectasis.

BACKGROUND: Persistent cough and large amounts of purulent sputum affects many bronchiectasis patients. No studies have evaluated the efficacy and safety of bronchoscopic airway clearance therapy and bronchoalveolar lavage (B-ACT) for non-cystic fibrosis bronchiectasis patients with acute exacerbation. METHODS: A randomised controlled trial was conducted to explore the efficacy and safety of B-ACT among 189 bronchiectasis inpatients from February 1, 2018 to February 28, 2019. The primary outcome was the time to first acute exacerbation. Secondary outcomes included changes of health-related scores, length of hospital stay, hospitalization expenses and incidences of adverse events. FINDINGS: B-ACT therapy significantly prolonged the median days to first acute exacerbation when compared with control group (198 vs 168 days, HR 0·555 (0·322-0·958), p=0·012; effect size(r)= 0·94). Further analysis showed that B-ACT therapy was more beneficial for these patients with severe disease and greater symptoms. COPD Assessment Test (CAT) scores improved significantly on the third day (5·45 vs 4·85, 0·60 (0·09-1·11), p=0·023), and Leicester Cough Questionnaire (LCQ) scores improved obviously on the third and seventh days (1·53 vs 1·23, 0·30 (0·05-0·55), p=0·044; 1·66 vs 1·32, 0·34 (0·08-0·60), p=0·022; respectively) after B-ACT therapy. Adverse events associated with B-ACT were mostly transient and mild. Differences of the lengths of hospital stay and hospitalization expenses in both group was not significant. INTERPRETATION: B-ACT therapy significantly prolonged the time to first acute exacerbation after discharge, highlighting the importance of B-ACT therapy focused on symptom improvements in preventing exacerbation. FUNDING: National Natural Science Foundation of China. TRIAL REGISTRY: ClinicalTrials.gov; No.:NCT03643302; URL: www.clinicaltrials.gov.