Environmental noise has been regarded as major noise pollutions with severe hazards to human physical and mental health. The common commercial fiber sound-absorption materials have insufficient low frequencies wave absorbing and fire-resistant ability, limiting their wide application. To solve those problem, a novel strategy combining flexible nanofibers and rGO/MXene nanosheets is proposed to fabricate rGO/MXene/SiO 2 nanofibers composite aerogel with hierarchically porous structured, which possess extremely low density of 9.8 mg/cm 3 and superior low-frequency sound absorption ability (NRC value of 0.51). The obtained composite aerogel possessed a large deformation up to 80% with compressive tress of 17KPa, and quickly recover. In addition, the obtained composite aerogel could be easily produced on a large scale, providing a reference for development of new generation of sound absorbing products.
Abstract Van der Waals (vdW) heterostructures, formed by stacking different two‐dimensional (2D) materials, have emerged as a promising platform for next‐generation optoelectronic devices through band engineering. While various all‐2D and mixed‐dimensional heterojunction phototransistors based on p–n junctions or Schottky junctions have been developed, their performance, often constrained by the trade‐off between responsivity ( R ) and response speed, limits their widespread application. Here, a dual‐mode phototransistor based on a MoTe 2 /WS 2 /WSe 2 double vdW heterostructure is designed. The bottom WSe 2 layer effectively modulates the entire MoTe 2 /WS 2 heterojunction channel, enabling both photoconductive and photovoltaic modes with exceptional optoelectronic properties in a single device. Specifically, the proposed device exhibits a maximum R of 2540 A W −1 and an impressive specific detectivity of 8 × 10 12 Jones under the photoconductive mode. Under the photovoltaic mode, it achieves a fast response speed of 35.3/49.1 µs and a high light on/off ratio of 2 × 10 5 . Additionally, the device exhibits latent potential for high‐resolution imaging across various wavelengths and fast optical communication. This work offers a rational alternative for achieving dual‐mode photodetection and highlights its promising application prospects in imaging and optical communication.
In recent years, radiofrequency (RF) ablation has been increasingly used for treating hepatic hemangiomas attributing to its unique advantages, such as minimal invasiveness, definite efficacy, high safety, fast recovery, and wide applicability. However, complications related to RF ablation had been frequently reported, especially while being used for treating huge hemangioma (≥10 cm). Cautious measures had been taken to prevent the incidence of ablation-induced complications, but still unexpected complications occurred. Herein we reported a case of severe myocardial dysfunction along with systemic inflammatory response syndrome occurring immediately post RF ablation of a 10.7 cm hemangioma. This serious complication was effectively managed by supportive care with the full recovery in a short period of time.
Abstract Limited lithium resources have promoted the exploration of new battery technologies. Among them, potassium‐ion batteries are considered as promising alternatives. At present, commercial graphite and other carbon‐based materials have shown good prospects as anodes for potassium‐ion batteries. However, the volume expansion and structural collapse caused by periodic K + insertion/extraction have severely restricted further development and application of potassium‐ion batteries. A hollow biomass carbon ball (NOP‐PB) ternarily doped with N, O, and P was synthesized and used as the negative electrode of a potassium‐ion battery. X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectroscopy, and transmission electron microscopy confirmed that the hollow biomass carbon spheres were successfully doped with N, O, and P. Further analysis proved that N, O, and P ternary doping expands the interlayer distance of the graphite surface and introduces more defect sites. DFT calculations simultaneously proved that the K adsorption energy of the doped structure is greatly improved. The solid hollow hierarchical porous structure buffers the volume expansion of the potassium insertion process, maintains the original structure after a long cycle and promotes the transfer of potassium ions and electrons. Therefore, the NOP‐PB negative electrode shows extremely enhanced electrochemical performance, including high specific capacity, excellent long‐term stability, and good rate stability.
Fire retardant coatings are moving towards environmentally friendly products, and the development of green flame retardants is gradually attracting the attention of researchers. In this work, spent coffee grounds (SCG) were modified with m-xylylenediamine phosphate ammonium (MAP) to create a bio-based flame retardant (SCG-g-MAP) for waterborne epoxy resin (WEP). The structure and composition of SCG-g-MAP were analyzed by a range of characterization tests, and the effects of SCG-g-MAP on the thermal stability, flame retardancy and fire resistance of WEP composite coatings were discussed. It revealed that WEP composite coating with 10% SCG-g-MAP and partial conventional intumescent fire retardant fillers, resulted in a LOI value of 29.5% and self-extinguishing capability. Moreover, the coating exhibited significantly improved fire resistance and thermal insulation properties due to its better thermal stability and excellent barrier function of forming carbon layer. This work presents a new attempt and inspiration for the application of biomass waste such as SCG for green flame retardant fillers.
Abstract Background Heat stroke (HS) is a severe systemic inflammatory response disease caused by high fever, mainly with nervous system damage. Currently, mesenchymal stem cells (MSCs) have inflammation and immunomodulatory effects. Therefore, we aimed to explore the protective effect and mechanism of MSCs on HS-induced excessive inflammation and neurological dysfunction. Methods A heat stroke Sprague-Dawley (SD) rat model was established at continuous high temperature (42 °C) and high humidity (70%-80%). After modeling, the rats were randomly divided into a heat stroke model group (HS group), a MSCs treatment group (HS + MSCs group), and a Control group in which the rats were kept at room temperature without any treatment. Survival analysis, neurological deficit scoring, pathological staining of hippocampus and cerebellum, immunofluorescence staining of microglia cells, and tissue level detection of inflammatory cytokines were performed in the three groups on day 1, 3, 7, 14 and 28 separately. Results After heat stroke modeling, the rats were severely paralyzed and had a high mortality. MSCs treatment significantly reduced the mortality in both early stage (day 3) and late stage (day 28). MSCs treatment also significantly reduced the neurological impairment of heat stroke rats, and improved hippocampal and cerebellar pathology and neuronal cell damage. In addition, MSCs treatment significantly inhibited the overactivation of microglia in the hippocampus of HS rats as well as the levels of pro-inflammatory factors and chemokines in the hippocampus. In the early stage (day 1) of MSCs treatment, the activation of cerebellar microglia in the heat stroke rats was significantly promoted. Meanwhile, MSCs treatment had no significant inhibitory effect on the levels of pro-inflammatory factors in the cerebellar tissues of heat stroke rats, but can inhibit the levels of chemokines in the early stage. Conclusions The application of MSCs for heat stroke treatment in rats can significantly reduce the mortality and neurological defects and improve the hippocampal injury. Meanwhile, MSCs can inhibit the over-activation of microglia cells in the hippocampus of heat stroke rats, which may be a mechanism of MSCs in protecting heat-stroke-caused hippocampal injury.
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Invited for this month's cover is the group of Weitang Yao at the Southwest University of Science and Technology. The image shows that developing low-cost and high-energy-density batteries is important for powering our city. The Si@SnS2 -rGO composites are good electrode materials for Li-ion batteries. The Full Paper itself is available at 10.1002/cssc.201902839.