The discovery of two‐dimensional (2D) materials with unique electronic, superior optoelectronic, or intrinsic magnetic order has triggered worldwide interest in the fields of material science, ...condensed matter physics, and device physics. Vertically stacking 2D materials with distinct electronic and optical as well as magnetic properties enables the creation of a large variety of van der Waals heterostructures. The diverse properties of the vertical heterostructures open unprecedented opportunities for various kinds of device applications, e.g., vertical field‐effect transistors, ultrasensitive infrared photodetectors, spin‐filtering devices, and so on, which are inaccessible in conventional material heterostructures. Here, the current status of vertical heterostructure device applications in vertical transistors, infrared photodetectors, and spintronic memory/transistors is reviewed. The relevant challenges for achieving high‐performance devices are presented. An outlook into the future development of vertical heterostructure devices with integrated electronic and optoelectronic as well as spintronic functionalities is also provided.
The diverse properties of van der Waals heterostructures open unprecedented opportunities for various types of device applications inaccessible in conventional heterostructure materials. Research progress of vertical heterostructure device applications in vertical transistors, infrared photodetectors, and spintronic devices is reviewed, together with a discussion on the challenges and opportunities in the future development of multifunctional devices.
Artificial muscles, providing safe and close interaction between humans and machines, are essential in soft robotics. However, their insufficient deformation, output force, or configurability usually ...limits their applications. Herein, this work presents a class of lightweight fabric‐lattice artificial muscles (FAMs) that are pneumatically actuated with large contraction ratios (up to 87.5%) and considerable output forces (up to a load of 20 kg, force‐to‐weight ratio of over 250). The developed FAMs consist of a group of active air chambers that are zigzag connected into a lattice through passive connecting layers. The geometry of these fabric components is programmable to convert the in‐plane lattice of FAMs into out‐of‐plane configurations (e.g., arched and cylindrical) capable of linear/radial contraction. This work further demonstrates that FAMs can be configured for various soft robotic applications, including the powerful robotic elbow with large motion range and high load capability, the well‐fitting assistive shoulder exosuit that can reduce muscle activity during abduction, and the adaptive soft gripper that can grasp irregular objects. These results show the unique features and broad potential of FAMs for high‐performance soft robots.
A class of fabric‐lattice artificial muscles with large contraction ratios, high output forces, and diverse configurations is proposed by connecting a group of fabric chambers and layers into a lattice. This artificial muscle can be designed with desired performance and configuration to enable high‐performance soft robots, including the powerful robotic elbow, the assistive shoulder exosuit, and the adaptive soft gripper.
This work describes a new one‐step large‐scale electrochemical synthesis of graphene/polyaniline (PANI) composite films using graphite oxide (GO) and aniline as the starting materials. The size of ...the film could be controlled by the area of indium tin oxide (ITO). Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible absorption spectrum (UV–vis) results demonstrated that the graphene/PANI composite film was successfully synthesized. The obtained graphene/PANI composite film showed large specific area, high conductivity, good biocompatibility, and fast redox properties and had perfect layered and encapsulated structures. Electrochemical experiments indicated that the composite film had high performances and could be widely used in applied electrochemical fields. As a model, horseradish peroxidase (HRP) was entrapped onto the film‐modified glassy carbon electrode (GCE) and used to construct a biosensor. The immobilized HRP showed a pair of well‐defined redox peaks and high catalytic activity for the reduction of H2O2. Furthermore, the graphene/PANI composite film could be directly used as the supercapacitor electrode. The supercapacitor showed a high specific capacitance of 640 F g−1 with a retention life of 90% after 1000 charge/discharge cycles.
A new one‐step electrochemical synthesis of graphene/polyaniline composite films was developed using graphite oxide and aniline as the starting materials. Horseradish peroxidase was entrapped onto the film‐modified electrode and used to construct a H2O2 biosensor. A supercapacitor was also fabricated based on the composite film.
Online reviews and customer Q&As have emerged as two vital forms of electronic word-of-mouth (eWOM) that significantly influence consumer decisions in e-commerce. Yet, a comprehensive understanding ...of the individual and combined roles of these eWOM types in shaping market dynamics remains elusive. This study addresses this research gap by tracking and analyzing three months of eWOM and sales data for 120 laptops on Amazon, comprising 7,205 online reviews, 6,365 customer Q&A questions, and 7,419 answers. Leveraging the Panel Vector Autoregression (PVAR) model and STATA16.0 software, we unravel the intricate dynamics between online reviews, customer Q&As, and laptop sales. The empirical results reveal distinctive influence mechanisms of online reviews and customer Q&As on product sales, with review volume and answer valence positively affecting sales. Importantly, answer volume was found to stimulate online reviews and enhance their valence. Our study elucidates the interplay among online reviews, customer Q&As, and product sales, underscoring the need for future research on multi-type eWOM. Further, the insights gleaned offer valuable guidance for online platforms and retailers to strategize their eWOM management.
Human action recognition has been applied in many fields, such as video surveillance and human computer interaction, where it helps to improve performance. Numerous reviews of the literature have ...been done, but rarely have these reviews concentrated on skeleton-graph-based approaches. Connecting the skeleton joints as in the physical appearance can naturally generate a graph. This paper provides an up-to-date review for readers on skeleton graph-neural-network-based human action recognition. After analyzing previous related studies, a new taxonomy for skeleton-GNN-based methods is proposed according to their designs, and their merits and demerits are analyzed. In addition, the datasets and codes are discussed. Finally, future research directions are suggested.
Graphene is nature's thinnest elastic material and displays exceptional mechanical and electronic properties. Ripples are an intrinsic feature of graphene sheets and are expected to strongly ...influence electronic properties by inducing effective magnetic fields and changing local potentials. The ability to control ripple structure in graphene could allow device design based on local strain and selective bandgap engineering. Here, we report the first direct observation and controlled creation of one- and two-dimensional periodic ripples in suspended graphene sheets, using both spontaneously and thermally generated strains. We are able to control ripple orientation, wavelength and amplitude by controlling boundary conditions and making use of graphene's negative thermal expansion coefficient (TEC), which we measure to be much larger than that of graphite. These results elucidate the ripple formation process, which can be understood in terms of classical thin-film elasticity theory. This should lead to an improved understanding of suspended graphene devices, a controlled engineering of thermal stress in large-scale graphene electronics, and a systematic investigation of the effect of ripples on the electronic properties of graphene.
Sepsis-associated acute lung injury (ALI) is a life-threatening condition in intensive care units with high mortality. LncRNAs have been confirmed to participate in the underlying pathogenesis of ...septic ALI. This study investigated the biological functions of lncRNA CDKN2B-AS1 in septic ALI and its potential mechanism.BEAS-2B cells were challenged with lipopolysaccharide (LPS) and mice were subjected to caecal ligation and puncture (CLP) to induce septic ALI in vitro and in vivo. The expression levels of CDKN2B-AS1, LIN28B, HIF-1α, and pyroptosis-related molecules were assessed by qRT-PCR or Western blotting. The production of IL-1β and IL-18 was detected by ELISA. BEAS-2B cell pyroptosis was examined by flow cytometry. The interaction between LIN28B and CDKN2B-AS1/HIF-1α was validated by RIP and RNA pull-down assays. Colocalization of CDKN2B-AS1 and LIN28B was observed by FISH. ALI was determined by HE staining, the lung wet-to-dry (W/D) weight ratio, inflammatory cell numbers, and total protein concentration in bronchoalveolar lavage fluid (BALF). Caspase-1 expression in the lung tissues was examined by immunohistochemical staining.CDKN2B-AS1 was upregulated in BEAS-2B cells after LPS stimulation. CDKN2B-AS1 knockdown inhibited pyroptosis in LPS-exposed BEAS-2B cells in vitro and the lung tissues of septic mice in vivo. Mechanistically, CDKN2B-AS1 interacted with LIN28B to enhance HIF-1α stability. Rescue experiments showed that HIF-1α overexpression counteracted the inhibitory effect of sh-CDKN2B-AS1 on LPS-induced pyroptosis. CDKN2B-AS1 bound to LIN28B to trigger NLRP3-mediated pyroptosis by stabilizing HIF-1α, which promoted sepsis-induced ALI. CDKN2B-AS1 might be a novel therapeutic target for this disease.
Abstract
With the outstanding mechanical properties, van der Waals (vdW) materials have attracted extensive attention in the research of straintronics in the past decade. In this perspective, we ...first review the recent progresses of the straintronics with vdW materials based on three different lattice deformation modes, i.e., in-plane strain, out-of-plane strain, and heterostrain. Then we discuss the current technique challenges in this field, and finally provide our perspectives on future research directions for both fundamental physics and electronic applications.
Background
The impacts of chronic airway diseases on coronavirus disease 2019 (COVID‐19) are far from understood.
Objective
To explore the influence of asthma and chronic obstructive pulmonary ...disease (COPD) comorbidity on disease expression and outcomes, and the potential underlying mechanisms in COVID‐19 patients.
Methods
A total of 961 hospitalized COVID‐19 patients with a definite clinical outcome (death or discharge) were retrospectively enrolled. Demographic and clinical information were extracted from the medical records. Lung tissue sections from patients suffering from lung cancer were used for immunohistochemistry study of angiotensin‐converting enzyme II (ACE2) expression. BEAS‐2B cell line was stimulated with various cytokines.
Results
In this cohort, 21 subjects (2.2%) had COPD and 22 (2.3%) had asthma. After adjusting for confounding factors, COPD patients had higher risk of developing severe illness (OR: 23.433; 95% CI 1.525‐360.135; P < .01) and acute respiratory distress syndrome (OR: 19.762; 95% CI 1.461‐267.369; P = .025) than asthmatics. COPD patients, particularly those with severe COVID‐19, had lower counts of CD4+ T and CD8+ T cells and B cells and higher levels of TNF‐α, IL‐2 receptor, IL‐10, IL‐8, and IL‐6 than asthmatics. COPD patients had increased, whereas asthmatics had decreased ACE2 protein expression in lower airways, compared with that in control subjects without asthma and COPD. IL‐4 and IL‐13 downregulated, but TNF‐α, IL‐12, and IL‐17A upregulated ACE2 expression in BEAS‐2B cells.
Conclusion
Patients with asthma and COPD likely have different risk of severe COVID‐19, which may be associated with different ACE2 expression.
After adjusting for confounding factors, COVID‐19 patients with COPD have higher risks of developing severe illness and acute respiratory distress syndrome than COVID‐19 patients with asthma. COPD patients have increased, whereas asthmatics have decreased ACE2 protein expression in lower airways, compared with that in control subjects without asthma and COPD. IL‐17A, TNF‐α, and IL‐12 promote, while IL‐4 and IL‐13 suppress ACE2 expression in airway BEAS‐2B cells. Abbreviations: ACE2, angiotensin‐converting enzyme II; ARDS, acute respiratory distress syndrome; BEAS‐2B, adenovirus‐12 SV40 hybrid virus transformed bronchial epithelial cells; COPD, chronic obstructive pulmonary disease; COVID‐19, coronavirus disease 2019.
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