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Background Microbial-driven decomposition of plant residues is integral to carbon sequestration in terrestrial ecosystems. Actinobacteria , one of the most widely distributed bacterial phyla in soils, are known for their ability to degrade plant residues in vitro. However, their in situ importance and specific activity across contrasting ecological environments are not known. Here, we conducted three field experiments with buried straw in combination with microcosm experiments with 13 C-straw in paddy soils under different soil fertility levels to reveal the ecophysiological roles of Actinobacteria in plant residue decomposition. Results While accounting for only 4.6% of the total bacterial abundance, the Actinobacteria encoded 16% of total abundance of carbohydrate-active enzymes (CAZymes). The taxonomic and functional compositions of the Actinobacteria were, surprisingly, relatively stable during straw decomposition. Slopes of linear regression models between straw chemical composition and Actinobacterial traits were flatter than those for other taxonomic groups at both local and regional scales due to holding genes encoding for full set of CAZymes, nitrogenases, and antibiotic synthetases. Ecological co-occurrence network and 13 C-based metagenomic analyses both indicated that their importance for straw degradation increased in less fertile soils, as both links between Actinobacteria and other community members and relative abundances of their functional genes increased with decreasing soil fertility. Conclusions This study provided DNA-based evidence that non-dominant Actinobacteria plays a key ecophysiological role in plant residue decomposition as their members possess high proportions of CAZymes and as a group maintain a relatively stable presence during plant residue decomposition both in terms of taxonomic composition and functional roles. Their importance for decomposition was more pronounced in less fertile soils where their possession functional genes and interspecies interactions stood out more. Our work provides new ecophysiological angles for the understanding of the importance of Actinobacteria in global carbon cycling. 3uWhKDWFjqsFeP9DMWUatJ Video abstract

Rice paddy fields are characterized by regular flooding and nitrogen fertilization, but the functional importance of aerobic ammonia oxidizers and nitrite oxidizers under unique agricultural management is poorly understood. In this study, we report the differential contributions of ammonia-oxidizing archaea (AOA), bacteria (AOB) and nitrite-oxidizing bacteria (NOB) to nitrification in four paddy soils from different geographic regions (Zi-Yang (ZY), Jiang-Du (JD), Lei-Zhou (LZ) and Jia-Xing (JX)) that are representative of the rice ecosystems in China. In urea-amended microcosms, nitrification activity varied greatly with 11.9, 9.46, 3.03 and 1.43 μg NO 3 − -N g −1 dry weight of soil per day in the ZY, JD, LZ and JX soils, respectively, over the course of a 56-day incubation period. Real-time quantitative PCR of amoA genes and pyrosequencing of 16S rRNA genes revealed significant increases in the AOA population to various extents, suggesting that their relative contributions to ammonia oxidation activity decreased from ZY to JD to LZ. The opposite trend was observed for AOB, and the JX soil stimulated only the AOB populations. DNA-based stable-isotope probing further demonstrated that active AOA numerically outcompeted their bacterial counterparts by 37.0-, 10.5- and 1.91-fold in 13 C-DNA from ZY, JD and LZ soils, respectively, whereas AOB, but not AOA, were labeled in the JX soil during active nitrification. NOB were labeled to a much greater extent than AOA and AOB, and the addition of acetylene completely abolished the assimilation of 13 CO 2 by nitrifying populations. Phylogenetic analysis suggested that archaeal ammonia oxidation was predominantly catalyzed by soil fosmid 29i4-related AOA within the soil group 1.1b lineage. Nitrosospira cluster 3-like AOB performed most bacterial ammonia oxidation in the ZY, LZ and JX soils, whereas the majority of the 13 C-AOB in the JD soil was affiliated with the Nitrosomona communis lineage. The 13 C-NOB was overwhelmingly dominated by Nitrospira rather than Nitrobacter . A significant correlation was observed between the active AOA/AOB ratio and the soil oxidation capacity, implying a greater advantage of AOA over AOB under microaerophilic conditions. These results suggest the important roles of soil physiochemical properties in determining the activities of ammonia oxidizers and nitrite oxidizers.

D-limonene (D-Lim) is a monocyclic monoterpene and the principal component of citrus essential oils; however, the potential mechanisms underlying its neuroprotective effects in traumatic brain injury (TBI) remain incompletely elucidated. By integrating network pharmacology, weighted gene co-expression network analysis (WGCNA), molecular docking, and experimental validation, this study systematically investigated the potential mechanisms through which D-Lim exerts neuroprotective activity. Database analyses and in vivo experiments showed that the anti-inflammatory and neuroprotective effects produced by D-Lim may be related to the p38 MAPK/NF-κB signaling axis and activation of the PI3K/AKT signaling pathway. Molecular docking and RT-PCR experiments indicated interactions between D-Lim and potential target proteins, including Icam1, Kdr, and Dpp4. HE and Nissl staining demonstrated that D-Lim ameliorated TBI-induced neuronal injury. Moreover, D-Lim had no observable effects on major organs and showed no peripheral toxicity, suggesting its favorable applicability for TBI intervention. Following early intervention with D-Lim, the inflammatory response induced by TBI was attenuated, which may be associated with the activation or modulation of the p38 MAPK, PI3K/AKT, and NF-κB p65 signaling pathways. These results indicate a potential acute protective role for D-Lim under prophylactic or early-intervention conditions, provide insights into TBI intervention, and establish a theoretical basis for potential preventive strategies.

Perovskite is an efficient and emerging catalyst for NO oxidation. In this study, BaMnO 3 and BaCoO 3 perovskite catalysts were synthesized by the sol-gel method, and their catalytic oxidation performances of NO were studied. The catalytic performances indicated that BaMnO 3 and BaCoO 3 perovskites had the highest NO oxidation activities with the NO conversions of 78.2% at 350 °C and 84.3% at 310 °C, respectively. The high activities of BaMnO 3 and BaCoO 3 perovskite catalysts were related to the abundant surface adsorption oxygen (O A  = 76.21% and 78.57%, respectively) and the high concentration of Mn 4+ (Mn 4+ /Mn = 66.95%) and Co 3+ (Co 3+ /Co = 63.8%). Moreover, the results of FT-IR and kinetics revealed that NO and O 2 adsorbed on the surface of samples and combined with the B-O band to form bidentate nitrate and bridging nitrate, which eventually was converted into NO 2 . The kinetics analysis revealed that the NO oxidation reaction followed the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. In addition, the activation energies were 36.453 kJ/mol for BaMnO 3 and 30.081 kJ/mol for BaCoO 3 , implying that BaMnO 3 and BaCoO 3 provide low-cost and efficient catalysts, which can be comparable to Pt noble metal catalysts.

Extracellular acidosis is considered as a hallmark of most human tumors, which plays an important role in promoting tumor malignant and aggressive phenotype in tumorigenesis. Acidosis and lactic acidosis can induce different responses in tumors. Previous studies have associated the response to lactic acidosis of tumors with good survival outcomes. In this study, we investigated the metabolomic changes in triple negative and luminal subtype breast cancer cell lines in response to acidosis and lactic acidosis. Our results showed that acidosis results in the reduction of cell viability and glycolysis in breast cancer cells, which is reversely correlated with the malignancy of cell lines. Under lactic acidosis, this reduction is reversed slightly. Untargeted metabolomic profiling revealed that glutaminolysis and fatty acid synthesis in cancer cells under acidosis are increased, while TCA cycle and glycolysis are decreased. Under lactic acidosis, the pentose phosphate pathway and acetate release are increased in MDA-MB-231 cells. The current results uncovered the different metabolic responses of breast cancer cells to acidosis and lactic acidosis, demonstrating the power of combined untargeted and stable isotope assisted metabolomics in comprehensive metabolomic analysis.

Pressure-induced charge density wave (CDW) state can overcome the low-temperature limitation for practical application, thus seeking its traces in experiments is of great importance. Herein, we provide spectroscopic evidence for the emergence of room temperature CDW order in the narrow pressure range of 10–15 GPa in bulk VSe 2 . Moreover, we discovered an 8-coordination structure of VSe 2 with C2/m symmetry in the pressure range of 35–65 GPa by combining the X-ray absorption spectroscopy, X-ray diffraction experiments, and the first-principles calculations. These findings are beneficial for furthering our understanding of the charge modulated structure and its behavior under high pressure.

Vacancy engineering effectively modulates the electronic properties of electrode materials, thereby improving their electrochemical performance. In this study, we prepared selenium-deficient NiCo2Se4 (Sev-NCS) using ethylene glycol as a reducing agent in NaOH alkaline environment, and investigated its potential as an electrode material for supercapacitors. Both theoretical and experimental results confirmed that the introduction of vacancies altered the morphology and electronic structure of NiCo2Se4, which in turn synergistically improved the conductivity and the diffusion capability of electrolyte ions. The optimized Sev-NCS electrode achieved an excellent specific capacitance of 2962.7 F g−1 at a current density of 1 A g−1 and superior cycling stability with a capacitance retention of 89.5% even after 10,000 cycles. Furthermore, an asymmetric device composed of the optimized Sev-NCS electrode as the positive electrode and activated carbon as the negative electrode achieved an energy density of 55.6 Wh kg−1 at a power density of 800 W kg−1. Therefore, this work offers novel insights into the role of vacancy engineering in improving the performance of transition metal compound-based electrode materials for supercapacitor.

The most prevalent and devastating form of organ damage in systemic lupus erythematosus (SLE) is lupus nephritis (LN). LN is characterized by glomerular injury, inflammation, cell proliferation, and necrosis, leading to podocyte injury and tubular epithelial cell damage. Assays for urine biomarkers have demonstrated significant promise in the early detection of LN, evaluation of disease activity, and tracking of reaction to therapy. This is because they are non-invasive, allow for frequent monitoring and easy self-collection, transport and storage. Podocyte injury is believed to be a essential factor in LN. The extent and type of podocyte injury could be connected to the severity of proteinuria, making podocyte-derived cellular debris and injury-related urinary proteins potential markers for the diagnosis and monitoring of LN. This article focuses on studies examining urinary biomarkers associated with podocyte injury in LN, offering fresh perspectives on the application of biomarkers in the early detection and management of LN.

To address environmental variations in metabolic composition of straw-decomposing bacterial community, we performed a 16-week field-based buried straw experiment at three experimental sites across subtropical China. We found that, although the taxonomic composition was highly variable, the functional composition was conserved across all experimental sites. This was likely because stochastic dispersal limitation governed the high taxonomic turnover of the community, leading to high environmental variability, whereas metabolic niche selection resulted in stable functional composition and lower redundancy. The integrated knowledge on the response of functional and taxonomic composition to environmental variability might help to understand microbial-driven straw decomposition at a large scale, considering the significance of microbial functional and taxonomic composition to biogeochemical cycling.

n-type Bi2(Te0.90Se0.10)3/(SiC)y (0 ≤ y ≤ 0.01) composites with nano-SiC were fabricated by mechanical alloying combined with microwave sintering. The microstructure and thermoelectric properties of Bi2(Te0.90Se0.10)3/(SiC)y were studied systematically. The nano-SiC particles as the phonon scattering center uniformly distributed in the matrix, with little effect on the electric transport performance and significantly reducing the thermal conductivity of n-type Bi2(Te0.90Se0.10)3/(SiC)y (0 ≤ y ≤ 0.01). The introduction of nano-SiC optimizes the thermoelectric performance, and the sample with SiC y = 0.0075 obtains the highest ZT~0.94 at 323 K.