Epidermal electronics are extensively explored as an important platform for future biomedical engineering. Epidermal devices are typically fabricated using high‐cost methods employing complex vacuum ...microfabrication processes, limiting their widespread potential in wearable electronics. Here, a low‐cost, solution‐based approach using electroconductive reduced graphene oxide (RGO) sheets on elastic and porous poly(dimethylsiloxane) (PDMS) thin films for multifunctional, high‐performance, graphene‐based epidermal bioelectrodes and strain sensors is presented. These devices are fabricated employing simple coatings and direct patterning without using any complicated microfabrication processes. The graphene bioelectrodes show a superior stretchability (up to 150% strain), with mechanical durability up to 5000 cycles of stretching and releasing, and low sheet resistance (1.5 kΩ per square), and the graphene strain sensors exhibit a high sensitivity (a gauge factor of 7 to 173) with a wide sensing range (up to 40% strain). Fully functional applications of dry bioelectrodes in monitoring human electrophysiological signals (i.e., electrocardiogram, electroencephalography, and electromyogram) and highly sensitive strain sensors for precise detection of large‐scale human motions are demonstrated. It is believed that our unique processing capability and multifunctional device platform based on RGO/porous PDMS will pave the way for low‐cost processing and integration of 2D materials for future wearable electronic skin.
A solution‐based approach using electroconductive reduced graphene oxide sheets on elastic and porous PDMS thin films for multifunctional, high‐performance, graphene‐based epidermal bioelectrode/strain sensors is presented. Fully functional applications of bioelectrodes in monitoring electrophysiological signals using human and strain sensors for precisely detecting large‐scale human motions are demonstrated.
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•C@WS2@Gs is synthesized via ball-milling and subsequent sulfidation process.•Graphene prevent aggregation and develop onion-like crystalline of WS2 nanoparticles.•Superior long-term ...cyclability is achieved at a high current density of 1000 mA g−1.•C@WS2@Gs anode exhibits notable electrochemical performance due to unique structure.
In this study, onion-like crystalline WS2 nanoparticles uniformly anchored on graphene sheets (WS2@Gs) were prepared via ball milling using WO3 nanoparticles and graphene and subsequent sulfidation. They were then employed as high-performance anode materials for Li-ion batteries (LIBs). The ball-milling process facilitated uniform anchoring of WO3 nanoparticles with a diameter of ∼15 nm on graphene nanosheets without aggregation, and the subsequent sulfidation caused phase transition of the WO3 nanoparticles to WS2 nanoparticles with an onion-like crystal lattice structure. As anode materials for LIB, the uniquely structured WS2@Gs nanocomposites exhibited excellent Li-ions storage performance, with a high reversible capacity of 587.1 mA h g−1 at a current density of 200 mA g−1. To enhance the cyclic stability of WS2@Gs, the C-coating method was employed by simply adding glucose during ball milling. Even at a high current density of 1000 mA g−1, the C-coated WS2@Gs (C@WS2@Gs) electrode exhibited a remarkably high reversible capacity of 371.9 mA h g−1 and appreciable cycling stability, with a high capacity retention of 62% without any drastic capacity fading after 500 cycles.
Although snoring is the most common subjective symptom in obstructive sleep apnea (OSA), an international consensus on the definition of snoring is lacking. This study aimed to define snoring by ...analyzing correlations between snoring parameters and the apnea hypopnea index (AHI). We retrospectively analyzed the polysomnography data of patients with OSA. A snoring event was defined when airflow pressure was > 200 microbar. We included four snoring parameters. Snoring percentage was defined as the cumulative time of snoring events divided by total sleep time. A snoring episode was defined as the occurrence of ≥ 3 consecutive snoring events, and the snoring episode index was defined as the number of snoring episodes per hour. The average and longest durations of snoring episodes were also investigated. The study enrolled 5035 patients. Their mean AHI was 26.5/h and the mean snoring episode index was 19.2/h. Although the four snoring parameters showed significant correlations with the AHI, the snoring episode index showed the strongest positive correlation with the AHI (r = 0.741, P < 0.001). The snoring episode index may be used as a definition of snoring from the perspective of a highly positive correlation with the AHI.
This research presents a new approach to developing an optical window film, leveraging the concept of charge‐transfer complex (CTC) intensification of colorless polyimide The window film demonstrates ...exceptional characteristics, including a tensile modulus of 8.4 GPa, a high total light transmittance of approximately 90%, and a yellow index below 3. This is the best‐recorded balance between mechanical strength and optical properties for a highly flexible optical film. Furthermore, the resulting film exhibits a pencil hardness grade surpassing 2H, alongside remarkable folding reliability, sustaining over 200,000 cycles of folding and unfolding. The excellent properties are ascribed to the unique supramolecular structure characterized by multiple hydrogen bonding and salt complexation interactions, significantly enhancing CTC intensification.
This letter proposes a novel protocol that uses Q-learning-based geographic routing (QGeo) to improve the network performance of unmanned robotic networks. A rapid and reliable network is essential ...for the remote control and monitoring of mobile robotic devices. However, controlling the network overhead required for route selection and repair is still a notable challenge, owing to high mobility of the devices. To alleviate this problem, we propose a machine-learning-based geographic routing scheme to reduce network overhead in high-mobility scenarios. We evaluate the performance of QGeo in comparison with other methods using the NS-3 simulator. We find that QGeo has a higher packet delivery ratio and a lower network overhead than existing methods.
The effects of exendin-4 on Sirt1 expression as a mechanism of reducing fatty liver have not been previously reported. Therefore, we investigated whether the beneficial effects of exendin-4 treatment ...on fatty liver are mediated via Sirt1 in high-fat (HF) diet-induced obese C57BL/6J mice and related cell culture models. Exendin-4 treatment decreased body weight, serum free fatty acid (FA), and triglyceride levels in HF-induced obese C57BL/6J mice. Histological analysis showed that exendin-4 reversed HF-induced hepatic accumulation of lipids and inflammation. Exendin-4 treatment increased mRNA and protein expression of Sirt1 and its downstream factor, AMPK, in vivo and also induced genes associated with FA oxidation and glucose metabolism. In addition, a significant increase in the hepatic expression of Lkb1 and Nampt mRNA was observed in exendin-4-treated groups. We also observed increased expression of phospho-Foxo1 and GLUT2, which are involved in hepatic glucose metabolism. In HepG2 and Huh7 cells, mRNA and protein expressions of GLP-1R were increased by exendin-4 treatment in a dose-dependent manner. Exendin-4 enhanced protein expression of Sirt1 and phospho-AMPKα in HepG2 cells treated with 0.4 mM palmitic acid. We also found that Sirt1 was an upstream regulator of AMPK in hepatocytes. A novel finding of this study was the observation that expression of GLP-1R is proportional to exendin-4 concentration and exendin-4 could attenuate fatty liver through activation of Sirt1.
Reactive Mn(IV) oxide minerals are ubiquitous in the environment and control the bioavailability and distribution of many toxic and essential elements and organic compounds. Their formation is ...thought to be dependent on microbial enzymes, because spontaneous Mn(II) to Mn(IV) oxidation is slow. Several species of marine Bacillus spores oxidize Mn(II) on their exosporium, the outermost layer of the spore, encrusting them with Mn(IV) oxides. Molecular studies have identified the mnx (Mn oxidation) genes, including mnxG , encoding a putative multicopper oxidase (MCO), as responsible for this two-electron oxidation, a surprising finding because MCOs only catalyze single-electron transfer reactions. Characterization of the enzymatic mechanism has been hindered by the lack of purified protein. By purifying active protein from the mnxDEFG expression construct, we found that the resulting enzyme is a blue (absorption maximum 590 nm) complex containing MnxE, MnxF, and MnxG proteins. Further, by analyzing the Mn(II)- and (III)-oxidizing activity in the presence of a Mn(III) chelator, pyrophosphate, we found that the complex facilitates both electron transfers from Mn(II) to Mn(III) and from Mn(III) to Mn(IV). X-ray absorption spectroscopy of the Mn mineral product confirmed its similarity to Mn(IV) oxides generated by whole spores. Our results demonstrate that Mn oxidation from soluble Mn(II) to Mn(IV) oxides is a two-step reaction catalyzed by an MCO-containing complex. With the purification of active Mn oxidase, we will be able to uncover its mechanism, broadening our understanding of Mn mineral formation and the bioinorganic capabilities of MCOs.
This study examines the efficacy of employing calcium sulfoaluminate (CSA) cement, an environmentally friendly binder, for enhancing the geomechanical characteristics of sand, particularly under low ...confining pressure conditions. A series of triaxial consolidated drained tests were performed on sand samples treated with varying content (5, 7, and 10%) of CSA cement and 10% ordinary Portland cement (OPC) under various low confining pressures (50, 100, 200, and 400 kPa). The test findings demonstrated the importance of cement content and confining pressure on the mode of failure, stress-strain and volumetric behavior, failure characteristics, and shear strength parameters of the treated quartz sand. After a curing period of 14 days, samples treated with 10% CSA cement exhibited a remarkable 212% increase in peak deviator stress and an 89% reduction in axial strain at failure, indicating higher initial stiffness compared to untreated samples under a 400 kPa confining pressure. Furthermore, the samples treated with 10% CSA exhibited higher peak deviator stress, initial stiffness, and strength development compared to those treated with 10% OPC. The scanning electron microscopy analysis provides insights into particle breakage and bond degradation processes, which increase with confining pressure in CSA-treated samples. Also, the mode of failure analysis reveals a transition from ductile to slightly brittle behavior with increasing cement content. Notably, the geomechanical properties of the treated material emphasized the significant impact of CSA cement on soil improvement. Thus offering a sustainable alternative for soil improvement in construction projects.
The B(C6F5)3‐catalyzed silylative reduction of conjugated nitriles has been developed to afford synthetically valuable β‐silyl amines. The reaction is chemoselective and proceeds under mild ...conditions. Mechanistic elucidation indicates that it proceeds by rapid double hydrosilylation of the conjugated nitrile to an enamine intermediate which is subsequently reduced to the β‐silyl amine, thus forming a new C(sp3)Si bond. Based on this mechanistic understanding, a preparative route to enamines was also established using bulky silanes.
Triple whammy: The B(C6F5)3‐catalyzed silylative reduction of conjugated nitriles has been developed to afford synthetically valuable β‐silyl amines. Based on the mechanistic understanding, a preparative route to enamines was also established using bulky silanes. The reaction is chemoselective, has a broad scope, and proceeds under mild reaction conditions. The mechanism of the triple hydrosilylation is discussed.
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