► Synthesizing polyaniline/strontium ferrite/MWCNT composites by in situ polymerization. ► With excellent magnetic and electromagnetic properties. ► The particular coating structure of PANI and ...Sr-ferrite. ► Great interest for magnetic material and microwave absorbers.
Strontium ferrite particles were firstly prepared by sol–gel method and self-propagating synthesis, and then the polyaniline/strontium ferrite/multiwalled carbon nanotubes composites were synthesized through in situ polymerization approach. Structure, morphology and properties of the composite were characterized by various instruments. XRD analysis shows that the output of PANI increases with the increase of the content of MWCNTs, due to the large surface area of MWCNTs. Because of the coating of PANI, the outer diameter of MWCNTs increases from 10nm to 20–40nm. The electrical conductivity of the composites increases with the amount increase of MWCNTs and reaches 7.2196S/cm in the presence of 2g MWCNTs. The coercive force of the composites prepared with 2g MWCNTs is 7457.17Oe, which is much bigger than that of SrFe12O19 particles 6145.6Oe, however, both the saturation magnetization and the remanent magnetization of the composite become much smaller than those of SrFe12O19 particles. The electromagnetic properties of the composite are excellent in the frequency range of 2–18GHz, which mainly depend on the dielectric loss in the range of 2–9GHz, and mainly on the magnetic loss in the range of 9–18GHz.
Fe3O4/NanoG was firstly prepared by precipitation reaction of iron oxide (Fe3O4) on the surface of graphite nanosheet (NanoG). Then composites PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were prepared ...by in-situ polymerization of the monomer pyrrole polymerized on the surface of NanoG, Fe3O4 and Fe3O4/NanoG. The structures of Fe3O4/NanoG, PPy, PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were characterized by scanning electron microscopy, energy dispersive spectroscopy, fourier transmission infrared spectroscopy and X-ray diffraction . Results show that NanoG and Fe3O4/NanoG are encapsulated by PPy for the layered structure and their high aspect ratio (300–500). From the thermogravimetric analysis it can be seen that the introductions of NanoG, Fe3O4 and Fe3O4/NanoG into PPy based composites lead them to exhibit better thermal stabilities than pure PPy. The measurements of electromagnetic parameters show that the reflection loss of PPy/Fe3O4/NanoG is below −15dB at the X band (8.2–12.4GHz) and the minimum loss value is −18.30dB at 9.84GHz, while the reflection loss of PPy/Fe3O4 is below −10dB at 8.2–12.4GHz and the minimum loss value is −14.02dB at 10.26GHz. The reflection loss of PPy/NanoG is below −10dB at 8.2–12.4GHz and the minimum loss value is −13.44dB at 10.28GHz. The microwave absorbing properties of PPy/Fe3O4/NanoG, PPy/Fe3O4 and PPy/NanoG are superior to that of PPy.
► Fe3O4 was chemically precipitated on the NanoG surface. ► PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were prepared by in-situ polymerization. ► The structures of Fe3O4/NanoG, PPy, PPy/NanoG, PPy/Fe3O4 and PPy/Fe3O4/NanoG were characterized by SEM, XRD, EDS and FTIR. ► Properties such as thermal stability, conductivity and microwave absorption were measured.
The design of a three-dimensional (3D) porous structure and rough surface morphology has proven to be a practical strategy for preparing highly efficient electromagnetic wave (EW) absorbents. In this ...study, ZnO nanoparticles were synthesized via a hydrothermal method, and MoSe2 nanoflowers were introduced and adhered to each other to form ZnSe@MoSe2 microspheres. The microspheres exhibit a 3D porous structure and rough surface morphology, allowing the EWs to effectively penetrate the material and forcing the EWs to undergo multiple reflections and scattering. Additionally, the excellent EW-absorbing performance of the composite results from the synergistic effect of multiple components. The maximum effective absorption bandwidth was 8.6 GHz, which was observed at a thickness of 2.2 mm and covered the entire Ku-band. The minimum reflection loss was − 44 dB, which was obtained at a thickness of 1.9 mm. This study provides significant insights into the design and preparation of highly efficient EW absorbents.
•This study proposes a novel three-dimensional porous structure composed of ZnSe nanoparticles and MoSe2 nanoflowers.•The synthesized material exhibits an effective absorption bandwidth (8.6 GHz) and a strong minimum reflection loss (−44 dB).•Surface morphology and size of the microspheres are controlled to obtain different electromagnetic diameters.•Porous structure helps to optimize the impedance matching.
Herpes simplex virus 1, an enveloped DNA virus belonging to the Herpesviridae family, spreads to neurons and causes pathological changes in the central nervous system. The purpose of this study was ...to investigate the potency and mechanism of antiviral activity of Aspergillipeptide D, a cyclic pentapeptide isolated from a culture broth of marine gorgonian-derived fungus Aspergillus sp. SCSIO 41501, At present, there are many studies on the anti-tumor, anti-clotting, anti-oxidant and immunoinflammatory effects of Aspergillipeptide D, but little research has been done on the anti-HSV-1 activity of Aspergillipeptide D.
The anti-HSV-1 activity of Aspergillipeptide D was evaluated by plaque reduction assay. The mechanism of action against HSV-1 was determined from the effective stage. Then we assayed the viral DNA replication, viral RNA synthesis and protein expression, respectively. We also identified the proteins that interact with gB by mass spectrometry, and assayed the effect of Aspergillipeptide D on the interaction between the virus gB protein and cell proteins.
Plaque reduction experiments showed that Aspergillipeptide D did not affect HSV-1 early infection events, including viral inactivation, attachment and penetration. Interestingly, Aspergillipeptide D dramatically reduced both the gene and protein levels of viral late protein gB, and suppressed its location in the endoplasmic reticulum and Golgi apparatus. In contrast, overexpression of gB restored viral production. Finally, proteomic analysis revealed that the numbers of cellular proteins that interacted with gB protein was largely decreased by Aspergillipeptide D. These results suggested that Aspergillipeptide D inhibited gB function to affect HSV-1 intercellular spread.
Our results indicated that Aspergillipeptide D might be a potential candidate for HSV-1 therapy, especially for ACV-resistant strains.
Alpinia
Miq. (AOM) is a medicinal herb for improving cognitive functions in traditional Chinese medicine for poststroke treatment, but its efficacies and underlying mechanisms remain unknown. In the ...present study, we tested the hypothesis that AOM could induce adult hippocampal neurogenesis and improve poststroke cognitive impairment
inducing brain-derived neurotrophic factor (BDNF) signaling pathway. In order to test the hypothesis, we performed both
rat experiments using transient middle cerebral artery occlusion (MCAO) model and
neural stem cell (NSC) experiments using oxygen-glucose deprivation plus reoxygenation. First, AOM treatment significantly up-regulated the expression of BDNF, tropomycin receptor kinase B (TrkB), and phosphorylated AKT (p-AKT) in the hippocampus, enhanced adult hippocampal neurogenesis, and improved the spatial learning/memory and cognitive functions in the post-MCAO ischemic rats
. Next,
studies confirmed
-coumaric acid (P-CA) to be the most effective compound identified from AOM extract with the properties of activating BDNF/TrkB/AKT signaling pathway and promoting NSC proliferation. Cotreatment of BDNF/TrkB-specific inhibitor ANA12 abolished the effects of P-CA on inducing BDNF/TrkB/AKT activation and the NSC proliferation. Finally, animal experiments showed that P-CA treatment enhanced the neuronal proliferation and differentiation in the hippocampus, improved spatial learning and memory functions, and reduced anxiety in the transient MCAO ischemic rats. In conclusion, P-CA is a representative compound from AOM for its bioactivities of activating BDNF/TrkB/AKT signaling pathway, promoting hippocampal neurogenesis, improving cognitive functions, and reducing anxiety in post-ischemic stroke rats.
Currently, there is significant interest in
as a promising next-generation probiotic, making it a hot topic in scientific research. However, to achieve efficient industrial production, there is an ...urgent need to develop an
culture method to achieve high biomass using low-cost carbon sources such as glucose. This study aims to explore the high-density fermentation strategy of
by optimizing the culture process. This study also employs techniques such as LC-MS and RNA-Seq to explain the possible regulatory mechanism of high-density cell growth and increased cell surface hydrophobicity facilitating cell colonization of the gut
culture. Overall, this research sheds light on the potential of
as a probiotic and provides valuable insights for future industrial production.
Water supply availability has significant impacts on the biggest base for commodity grain production: The Sanjiang Plain in northeast China. The SWAT (soil and water assessment tool) model and ...IHACRES (identification of unit hydrographs and component flows from rainfall, evapotranspiration and streamflow data) model were used for modelling streamflow variability in the upper Naoli River watershed to determine the applicability of hydrological models to the marsh rivers. Both the SWAT and IHACRES models were suitable for streamflow simulation, having R2 (coefficient of determination) and NS (Nash–Sutcliffe) values greater than 0.7, and PBIAS (percent bias) smaller than 25%. The IHACRES model was easy to use, with less data-preparation, and was found to be a better choice for runoff simulation in a watershed less affected by human activity. The simulation result was better in primeval times, i.e., 1956–1966, than the period 1967–2005, when its performance was found to be unfavorable. In contrast, the complex, processes-based SWAT model was found to be more appropriate for simultaneously simulating streamflow variability. In addition, the effects of land use change and human activities in the watershed—where agricultural activities are intensive—were evaluated. The study found that the SWAT model was potentially suitable for water resource planning and management.
Understanding the evolutionary characteristics of innovation network structure can improve urban innovation and regional construction. Urban innovative development is affected by various factors, ...which can be analyzed via models of innovation networks. We establish a multi-criteria evaluation system of innovation capability and use an improved gravity model to construct an innovation network for 2015–2018, employing social network methods to analyze structural characteristics and spatial patterns. Results show that: (1) The innovation of cities in the urban agglomeration in the middle reaches of the Yangtze River has gradually increased, with an accompanying increase in the complexity of innovation networks. The cities of Wuhan, Changsha, and Nanchang are located at the absolute core of this network, which exhibits a Matthew effect, and has a triangle integration mode of growth. (2) The attraction of innovative resources and the promotion of individual innovation are increasing every year within the cities. The aggregation pattern of innovation shows a multi-core state in the urban agglomeration in the middle reaches of the Yangtze River, but the innovation radiation pattern has changed from a single center to a double center. (3) Multiple spatial innovation axes are seen in the network, with a location and direction consistent with the urban agglomeration’s development axis in the Yangtze River’s middle reaches and a triangle integration growth mode. Policy implications are proposed for regional innovation and development, and our results can provide future policy guidance and direction for governmental entities and other stakeholders.
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