Swelling is ubiquitous for conventional hydrogels but is not favorable for many situations, especially underwater applications. In this study, an anti‐swelling and mechanically robust polyacrylic ...acid (PAAc)/gelatin composite hydrogel is reported with a rapid gelation process (101 s) under mild conditions via the synergy of MXene‐activated initiation and zirconium ion (Zr4+)‐induced cross‐linking, without the requirement of external energy input. The MXene is found efficient to activate the chain initiation, while the Zr4+ is prone indispensable for facilitating the cross‐linking of formed polymer chains. The resulting hydrogel exhibits integration of exceptional anti‐swelling properties and high mechanical performance at room temperature, thanks to the dense hydrogen bonds between PAAc and gelatin chains that enable an upper critical solution temperature above room temperature. Also, desirable electrical conductivity emerges in the hydrogel due to the simultaneous contribution of MXene and Zr4+, allowing stable electrical signal output of the gel upon deformation underwater. As a demonstration, an underwater communicator by harnessing the gel as a sensing module is assembled, which is capable of wirelessly delivering messages to the decoder on the ground via Morse codes. This study provides an exemplary way for the rapid gelation of tough and anti‐swelling hydrogels for durable underwater applications.
Rapid gelation of tough and anti‐swelling hydrogels under mild conditions is enabled by the synergistic effect of MXene and zirconium ions, without requiring external energy input. The MXene facilitates the chain initiation, while the zirconium ions cross‐link the formed polymer chains. The resulting hydrogels exhibit an upper critical solution temperature behavior to resist swelling at room temperature, promising their applications in underwater communication.
Appling phosphorus (P) fertilizer to agroecosystems affects not only crop yield but also associated soil microbial communities. The bacterial phoD gene encodes alkaline phosphatase (ALP) and plays an ...important role in organic P decomposition in soils. However, the impacts of long-term P fertilization on the bacterial phoD gene community, the total bacterial community, and the relationships of these communities with soil properties are poorly understood in loess soils with available-P deficiency. In this study, the impact of mineral P fertilization on the soil bacterial community was assessed. The 16S rRNA and phoD genes were targeted in DNA extracted from wheat rhizosphere soils subjected to five P fertilization rates (0 (P0), 50 (P50), 100 (P100), 150 (P150) and 200 (P200) kg P2O5 ha−1 yr−1) applied annually for 14 years. Compared to the P0 treatment, the P fertilization treatments increased the soil organic C (SOC), microbial biomass C (MBC) and available P (AP), and in the high-P treatments (P150 and P200) the total P (TP) and organic P (OP) increased, while the ALP activity decreased. All P fertilization treatments reduced the total bacterial diversity (Shannon index). However, only P200 decreased the number of operational taxonomic units (OTUs) with the 16S rRNA gene, and no P fertilization treatments affected phoD-harboring bacterial OTUs or diversity when compared to those in the P0 treatment. Additionally, compared to P0, the P fertilization treatments changed the 16S rRNA and phoD gene bacterial community compositions, with increased relative abundances of 3 phyla and 7 genera and decreased abundances of 1 phylum and 2 genera for the 16S rRNA gene and increased abundances of 4 genera and decreased abundances of 2 phyla and 1 genus for the phoD gene. Microbial network analysis showed that the high-P treatments (P150 and P200) reduced the number of links in the microbial network at the genus level for the 16S rRNA gene. Principal coordinate analysis (PCoA) showed that P fertilization treatments shifted the total bacterial community structure, and redundancy analysis (RDA) revealed that soil dissolved organic C (DOC) and P (AP, OP, TP and ALP) levels were significantly related to the total bacterial community structure. In conclusion, this study demonstrated that long-term P fertilization significantly affected soil C and P as well as the total and phoD-harboring bacterial community compositions in wheat rhizosphere soils and that high P fertilizer application rates reduced total bacterial OTUs, diversity and the connections, which might affect soil biogeochemical cycles.
•SOC, MBC and available P were increased by P fertilization.•Alkaline phosphatase activity was reduced in soils with high P input.•P input reduced total bacterial diversity and changed total bacterial community structure.•High P input reduced the links of microbial network for 16S rRNA gene.•Total bacterial community structure was closely related to soil DOC and P (AP, OP, TP and ALP).
Two novel isostructural polyoxometalate (POM)-based metal-organic frameworks (MOFs) with diamond topology, NENU-506 and NENU-507, were hydrothermally synthesized. They not only combine the advantages ...of both POMs and MOFs, but also show excellent chemical and thermal stability. Notably, NENU-507 exhibited a high reversible capacity of 640 mA h g
after 100 cycles when applied as an anode material in lithium-ion batteries.
Large quantities of organic dyes are discharged into the environment, causing serious damage to the ecosystem. Therefore, it is urgent to develop inexpensive adsorbents to remove organic dyes. A ...novel cellulose-based aerogel (MPPA) with 3D porous structure was prepared by using cassava residue (cellulose) as basic construction blocks, doping ferroferric oxide (Fe3O4) for magnetic separation, and applying polyethyleneimine (PEI) as functional material for highly efficient and selective capture of Congo red (CR). MPPA exhibited porous network structure, numerous active capture sites, nontoxicity, high hydrophilicity, and excellent thermal stability. MPPA showed superior adsorption property for CR, with an equilibrium adsorption capacity of 2018.14 mg/g, and still had an adsorption property of 1189.31 mg/g after five recycling procedures. In addition, MPPA has excellent selectivity for CR in four binary dye systems. The adsorption behavior of MPPA on CR was further explored using a multilayer adsorption model, EDR-IDR hybrid model and AOAS model. Electrostatic potential and independent gradient models were used to further verify the possible interaction between MPPA and CR molecules. In conclusion, MPPA is a promising adsorbent in the field of treating anionic dyes.
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•A novel magnetic cassava pomace based aerogel was designed and synthesized.•MPPA can effectively removes Congo red from wastewater.•In vitro cytotoxicity tests were used to validate the safety of MPPA.•Density functional theory was applied to visualise the adsorption interactions.•The phenomenological models proposed new insights into sorption mass transfer.
The origin and evolution of polyploids have been studied extensively in angiosperms and ferns but very rarely in gymnosperms. With the exception of three species of conifers, all natural polyploid ...species of gymnosperms belong to Ephedra, in which more than half of the species show polyploid cytotypes. Here, we investigated the origin and evolution of polyploids of Ephedra distributed in the Qinghai–Tibetan Plateau (QTP) and neighbouring areas. Flow cytometry (FCM) was used to measure the ploidy levels of the sampled species that are represented by multiple individuals from different populations, and then, two single‐copy nuclear genes (LFY and DDB2) and two chloroplast DNA fragments were used to unravel the possible origins and maternal donors of the polyploids. The results indicate that the studied polyploid species are allopolyploids, and suggest that allotetraploidy is a dominant mode of speciation in Ephedra. The high percentage of polyploids in the genus could be related to some of its biological attributes such as vegetative propagation, a relatively high rate of unreduced gamete formation, and a small genome size relative to most other gymnosperms. Significant ecological divergences between allotetraploids and their putative progenitors were detected by PCAs and anova and Tukey's tests, with the exception of E. saxatilis. The overlap of geographical distributions and ecological niches of some diploid species could have provided opportunities for interspecific hybridization and allopolyploid speciation.
Induction of the transcriptional repressor Bcl-6 in CD4+ T cells is critical for the differentiation of follicular helper T cells (TFH cells), which are essential for B cell-mediated immunity. In ...contrast, the transcription factor Blimp1 (encoded by Prdm1) inhibits TFH differentiation by antagonizing Bcl-6. Here we found that the transcription factor TCF-1 was essential for both the initiation of TFH differentiation and the effector function of differentiated TFH cells during acute viral infection. Mechanistically, TCF-1 bound directly to the Bcl6 promoter and Prdm1 5' regulatory regions, which promoted Bcl-6 expression but repressed Blimp1 expression. TCF-1-null TFH cells upregulated genes associated with non-TFH cell lineages. Thus, TCF-1 functions as an important hub upstream of the Bcl-6-Blimp1 axis to initiate and secure the differentiation of TFH cells during acute viral infection.
Quercetin, a plant-derived flavonoid in Chinese herbs, fruits and wine, displays antioxidant properties in many pathological processes associated with oxidative stress. However, the effect of ...quercetin on the development of preimplantation embryos under oxidative stress is unclear. The present study sought to determine the protective effect and underlying mechanism of action of quercetin against hydrogen peroxide (H2O2)-induced oxidative injury in mouse zygotes. H2O2 treatment impaired the development of mouse zygotes in vitro, decreasing the rates of blastocyst formation and hatched, and increasing the fragmentation, apoptosis and retardation in blastocysts. Quercetin strongly protected zygotes from H2O2-induced oxidative injury by decreasing the reactive oxygen species level, maintaining mitochondrial function and modulating total antioxidant capability, the activity of the enzymatic antioxidants, including glutathione peroxidase and catalase activity to keep the cellular redox environment. Additionally, quercetin had no effect on the level of glutathione, the main non-enzymatic antioxidant in embryos.
Levoglucosan (LGA), as the main primary anhydrosugar of cellulose pyrolysis, is of great significance for future value-added chemicals production. In this study, effective conversion of LGA to ...5-hydroxymethylfurfural (HMF) was investigated in a NaCl–H2O/acetone biphasic system over sulfonated resin and AlCl3. The results show that the biphasic system could efficiently inhibit the overreaction of HMF compared with pure water, leading to a significant enhancement of HMF production. HMF was obtained with the highest yield of 68.5 % at 96.5 % of LGA conversion at the optimized conditions. The use of cellobiose as substrate produced 61 % of HMF while LGA-rich bio-oil led to a sharp decease of HMF yield to 33 %. Through the respective experiments using LGA, glucose and fructose as the substrates, the reaction network was constructed for kinetic analysis, and satisfactory fitting results are observed in agreement with the experimental results, providing the best conditions for producing glucose and HMF, respectively. In addition, the mechanism of LGA conversion to HMF was calculated by DFT, which needs to overcome the highest free energy barrier of 121 kJ/mol.
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•LGA conversion to HMF is employed in a NaCl–H2O/acetone biphasic system.•The reaction pathway is clarified by the synergistic effect of sulfonated resin and AlCl3.•HMF was obtained with the highest yield of 68.5 % at 96.5 % of LGA conversion.•Results predicted by the kinetics are well consistent with the experimental results.•LGA conversion to HMF has an energy barrier of 121 kJ/mol by DFT calculations.
In the context of complex and dynamic marine environment, the offloading of computing tasks for ships of Internet of Things (IoT) users is a very challenging problem considering the different quality ...of service (QoS) requirements of maritime applications. Mobile edge computing driven by powerful computing capability and edge intelligence is taken as a promising solution, especially for the resource-constrained and delay-sensitive maritime IoT users. In this paper, we study the optimal edge server selection problem for ship IoT users to jointly minimize the latency and energy consumption for task offloading. Specifically, we first propose a novel space-air-ground-edge (SAGE) integrated maritime network architecture to offload computation-intensive IoT services at sea. Then, the latency and energy consumption of data transmission and processing during offloading are modelled. Based on the models, the edge server selection problem is formulated into a Multi-Armed Bandits learning problem, with considering the task latency requirement and energy budget. To achieve the optimal solution, a novel algorithm, referred to as UCB1-ESSS, is developed, which links the latency, energy consumption, and network constraints by introducing both reward and cost. The simulation results show that the proposed algorithm can achieve considerably lower offloading latency and weighted latency-energy cost compared with the traditional algorithms under different QoS requirements, which proves the efficacy of theproposed algorithm.
Distinct microRNA (miRNA) profiles have been reported in premature ovarian insufficiency (POI), but their functional relevance in POI is not yet clearly stated. In this study, aberrant expressions of ...miR‐127‐5p and high mobility group box 2 (HMGB2) were observed by microarrays in granulosa cells (GCs) from biochemical POI (bPOI) women and further confirmed by a quantitative reverse‐transcription polymerase chain reaction. Immortalized human granulosa cell line and mouse primary ovarian GCs were used for functional validation. Orthotopic mouse model was established to examine the role of miR‐127‐5p in vivo. Finally, the expression of miR‐127‐5p was measured in the plasma of bPOI women. The receiver operating characteristic curve analysis was performed to determine the indicative role of miR‐127‐5p for ovarian reserve. Results showed the upregulation of miR‐127‐5p was identified in GCs from bPOI patients. It inhibited GCs proliferation and impaired DNA damage repair capacity through targeting HMGB2, which was significantly downregulated in GCs from the same cohort of cases. miR‐127‐5p was confirmed to attenuate DNA repair capability via HMGB2 in mouse ovary in vivo. Intriguingly, the upexpression of miR‐127‐5p was also detected in plasma of bPOI individuals, suggesting that miR‐127‐5p could be a promising indicator for bPOI. Taken together, our results discovered the deleterious effects of miR‐127‐5p on GCs function and its predictive value in POI process. The target gene HMGB2 could be considered as a new candidate for POI. This study highlights the importance of DNA repair capacity for ovarian function and sheds light on the epigenetic mechanism in the pathogenicity of POI.
This study identified the deleterious effects of miR‐127‐5p on granulosa cells function and its predictive value in premature ovarian insufficiency (POI) process. The target gene HMGB2 could be considered as a new candidate for POI. This study highlights the importance of DNA repair capacity for ovarian function and sheds light on the epigenetic mechanism in the pathogenicity of POI.
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