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BaCu2−xMnxSi2O7 (x = 0–0.04) microwave dielectric ceramics were synthesized through solid-state reaction method. Effects of substitution with Mn2+ ions for Cu2+ ions on phase composition, crystal structure, and microwave dielectric properties of BaCu2Si2O7 ceramics were investigated in detail. XRD results revealed that BaCu2Si2O7 solid solution with orthorhombic structure was formed in all samples. Under combined action of porosity and ionic polarizability, εr values of BaCu2−xMnxSi2O7 ceramics showed a tendency of first increasing and then decreasing with doping content of Mn2+ ions. The variation in Qf was attributed to the change of porosity and total lattice energy. The decrease in average bond energy contributed to falling τf values. Besides, Raman shifts that resulted from stretching vibration of Cu–O bond exhibited an opposite trend compared with εr. FWHM of Raman peak for Si–O bond varied inversely with the Qf of BaCu2−xMnxSi2O7 ceramics. The optimal properties were attained for BaCu2−xMnxSi2O7 (x = 0.02) ceramics sintered at 1020 °C: εr = 8.12, Qf = 54,692 GHz, and τf = − 29.5 ppm/°C. [ABSTRACT FROM AUTHOR]

Low permittivity CaMg 1- x (Mn 1/2 Zn 1/2) x Si 2 O 6 (x = 0-0.1) ceramics were synthesized via the solid-state reaction process for the first time. The Rietveld refinement, complex chemical bond theory and Raman spectra were introduced to analyze the effects of Mn2+/Zn2+ co-substitution to microwave dielectric properties. XRD spectra indicate the CaMg 1- x (Mn 1/2 Zn 1/2) x Si 2 O 6 ceramics processed the pure phase of CaMgSi 2 O 6 when x ≤ 0.02 and a small volume of secondary phase Ca 2 MgSi 2 O 7 for 0.04 ≤ x ≤ 0.1. The variation of ε r can be put down to average bond iconicity and Raman shift. Total lattice energy and packing fraction are main influence factor of the Q × f value. The monotonous decrease of τ f is associated with total bond valence and full width at half maximum of Raman peak. Additionally, CaMg 1- x (Mn 1/2 Zn 1/2) x Si 2 O 6 (x = 0.02) ceramics sintered at 1280 °C for 3 h exhibited excellent microwave dielectric properties of ε r = 8.16, Q × f = 70187, τ f = −38.48 ppm/°C. [ABSTRACT FROM AUTHOR]

Abstract Coastal wetlands are widely recognized as atmospheric methane sources. However, recent field studies suggest that some coastal wetlands could also act as methane sinks, but the mechanism is not yet clear. Here, we investigated methane oxidation with different electron acceptors (i.e., oxygen, nitrate/nitrite, sulfate, Fe(III) and Mn(IV)) in four coastal wetlands in China using a combination of molecular biology methods and isotopic tracing technologies. The geochemical profiles and in situ Gibbs free energies suggest that there was significant nitrite-dependent anaerobic oxidation of methane (nitrite-AOM) in the sub-surface sediments; this was subsequently experimentally verified by both the microbial abundance and activity. Remarkably, the methanotrophic communities seemed to exist in the sediments as layered structures, and the surface aerobic methane-oxidizing bacteria were able to take up atmospheric methane at a rate of 0.10–0.18 nmol CH 4 day−1 cm−2, while most, if not all, sedimentary methane was being completely consumed by anaerobic methanotrophs (23–58% by methane oxidizers in phylum NC10). These results suggest that coastal methane sinks might be governed by diverse microbial communities where NC10 methane oxidizers contributed significantly. This finding helps to better understand and predict the coastal methane cycle and reduce uncertainties in the estimations of the global methane flux. Graphical abstract Image 1 Highlights • Methane oxidation with different electron acceptors were investigated in four coasts. • A structured gradient of microbial methane oxidizers was found in coastal sediments. • Sub-surface NC10 bacteria were the dominant sink of coastal sedimentary methane. • Coastal sediments are weak atmospheric methane sinks in some nitrogen-rich areas. A structured gradient of microbial methane oxidizers was discovered in coastal sediments, and sub-surface NC10 methane oxidizers were the dominant methane sink. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus ( S. aureus ) is one of the most common foodborne pathogens worldwide, which poses a great threat to public health. It is of utmost importance to develop rapid, simple, and sensitive methods for the determination of S. aureus . A signal-on photoelectrochemical (PEC) aptasensor is constructed herein based on titanium carbide (Ti 3 C 2 T x )-Au nanobipyramids (NBPs)/ZnO nanoarrays (NRs). The reliability and capability of the PEC aptasensor make it suitable for the sensitive and selective determination of S. aureus . First, the electrostatically self-assembled Ti 3 C 2 T x -Au NBP nanomaterial was coated on the ZnO NR surface by a spin-coating method. On the one hand, Ti 3 C 2 T x -Au NBPs can broaden the spectral absorption of ZnO NRs, resulting in Ti 3 C 2 T x -Au NBPs/ZnO NR composites that exhibit a wide range of absorption from the ultraviolet to the infrared region. On the other hand, Ti 3 C 2 T x can reduce the agglomeration of nanoparticles, while Au NBPs can effectively fix the aptamer through the Au-S bond. Specifically, the experimental results show that when S. aureus is present, the Au NBPs-aptamer- S. aureus complex is shed from the electrode surface, altering the interfacial electron transfer model and reducing the steric hindrance. Consequently, an amplified photocurrent signal for the quantitative determination of S. aureus is obtained. Under optimal experimental conditions, a linear correlation is observed between the current response of the aptasensor and the logarithm of the S. aureus concentration (ranging from 1.0 to 1.0 × 10 6 CFU/mL), with an impressive detection limit as low as 0.5 CFU/mL. Furthermore, the aptasensor has been successfully employed for the detection of S. aureus in milk, with the recovery of 93.0%-99.0%. Hence, this research offers a novel approach for the detection of foodborne pathogens and other noxious substances.

Mitophagy selectively eliminates damaged or dysfunctional mitochondria, playing a crucial role in maintaining mitochondrial quality control. However, it remains unclear whether mitophagy can be fully activated and how it evolves after SCI. Our RNA-seq analysis of animal samples from sham and 1, 3, 5, and 7 days post-SCI indicated that mitophagy was indeed inhibited during the acute and subacute early stages. In vitro experiments showed that this inhibition was closely related to excessive production of reactive oxygen species (ROS) and the downregulation of BNIP3. Excessive ROS led to the blockage of mitophagy flux, accompanied by further mitochondrial dysfunction and increased neuronal apoptosis. Fortunately, ligustilide (LIG) was found to have the ability to reverse the oxidative stress-induced downregulation of BNIP3 and enhance mitophagy through BNIP3-LC3 interaction, alleviating mitochondrial dysfunction and ultimately reducing neuronal apoptosis. Further animal experiments demonstrated that LIG alleviated oxidative stress and mitophagy inhibition, rescued neuronal apoptosis, and promoted tissue repair, ultimately leading to improved motor function. In summary, this study elucidated the state of mitophagy inhibition following SCI and its potential mechanisms, and confirmed the effects of LIG-enhanced mitophagy through BNIP3-LC3, providing new therapeutic targets and strategies for repairing SCI., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Spinal cord injury (SCI) results in massive neuronal death, axonal disruption, and cascading inflammatory response, which causes further damage to impaired neurons. The survived neurons with damaged function fail to form effective neuronal circuits. It is mainly caused by the neuroinflammatory microenvironment at injury sites and regenerated axons without guidance. To address this challenge, a ferrofluid hydrogel (FFH) was prepared with Ferric tetrasulfide (Fe 3 S 4 ), carboxymethyl chitosan, and gold. Its internal structural particles can be oriented in a magnetic field to acquire anisotropy. Moreover, Fe 3 S 4 can release hydrogen sulfide (H 2 S) with anti-inflammatory effects under acidic conditions. Regarding in vitro experiments, 0.01g/ml Fe 3 S 4 FFH significantly reduced the inflammatory factors produced by LPS-induced BV2 cells. Oriented and longer axons of the induced neural stem cells loaded on anisotropic FFH were observed. In vivo experiments showed that FFH reduced the activated microglia/macrophage and the expression of pro-inflammatory factors in SCI rats through the NF-κB pathway. Moreover, it significantly promoted directional axonal regrowth and functional recovery after SCI. Given the critical role of inhibition of neuroinflammation and directional axonal growth, anisotropic Fe 3 S 4 FFH is a promising alternative for the treatment of SCI., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could appear to influence the work reported in this paper., (© 2022 The Authors.)

Methane is a primary greenhouse gas which is responsible for global warming. The sulfate-dependent anaerobic methane oxidation (S-AOM) process catalyzed by an aerobic me thanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB) is a vital link connecting the global carbon and sulfur cycles, and it is considered to be the overriding methane sink in marine ecosystem. However, there have been few studies regarding the role of S-AOM process and the distribution of ANME archaea in intertidal ecosystem. The intertidal zone is a buffer zone between sea and land and plays an important role in global geochemical cycle. In the present study, the abundance, potential methane oxidation rate, and community structure of ANME archaea in the intertidal zone were studied by quantitative PCR, stable isotope tracing method and high-throughput sequencing. The results showed that the potential S-AOM activity ranged from 0 to 0.77 nmol 13 CO 2 g -1 (dry sediment) day -1 The copy number of 16S rRNA gene of ANME archaea reached 10 6 ∼ 10 7 copies g -1 (dry sediment). The average contribution of S-AOM to total anaerobic methane oxidation was up to 34.5%, while denitrifying anaerobic methane oxidation accounted for the rest, which implied that S-AOM process was an essential methane sink that cannot be overlooked in intertidal ecosystem. The simulated column experiments also indicated that ANME archaea were sensitive to oxygen and preferred anaerobic environmental conditions. This study will help us gain a better understanding of the global carbon-sulfur cycle and greenhouse gas emission reduction and introduce a new perspective into the enrichment of ANME archaea. IMPORTANCE The sulfate-dependent anaerobic methane oxidation (S-AOM) process catalyzed by an aerobic me thanotrophic (ANME) archaea and sulfate-reducing bacteria (SRB) is a vital link connecting the global carbon and sulfur cycles. We conducted a research into the spatial-temporal pattern of S-AOM process and the distribution of ANME archaea in coastal sediments collected from the intertidal zone. The results implied that S-AOM process was a methane sink that cannot be overlooked in the intertidal ecosystem. We also found that ANME archaea were sensitive to oxygen and preferred anaerobic environmental conditions. This study will help us gain a better understanding of the global carbon-sulfur cycle and greenhouse gas emission reduction and introduce a new perspective into the enrichment of ANME archaea., (Copyright © 2019 American Society for Microbiology.)

Anaerobic oxidation of methane (AOM) coupled to nitrite reduction is a novel AOM process that is mediated by denitrifying methanotrophs. To date, enrichments of these denitrifying methanotrophs have been confined to freshwater systems; however, the recent findings of 16S rRNA and pmoA gene sequences in marine sediments suggest a possible occurrence of AOM coupled to nitrite reduction in marine systems. In this research, a marine denitrifying methanotrophic culture was obtained after 20 months of enrichment. Activity testing and quantitative PCR (qPCR) analysis were then conducted and showed that the methane oxidation activity and the number of NC10 bacteria increased correlatively during the enrichment period. 16S rRNA gene sequencing indicated that only bacteria in group A of the NC10 phylum were enriched and responsible for the resulting methane oxidation activity, although a diverse community of NC10 bacteria was harbored in the inoculum. Fluorescence in situ hybridization showed that NC10 bacteria were dominant in the enrichment culture after 20 months. The effect of salinity on the marine denitrifying methanotrophic culture was investigated, and the apparent optimal salinity was 20.5‰, which suggested that halophilic bacterial AOM coupled to nitrite reduction was obtained. Moreover, the apparent substrate affinity coefficients of the halophilic denitrifying methanotrophs were determined to be 9.8 ± 2.2 μM for methane and 8.7 ± 1.5 μM for nitrite., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)