Microbial fuel cells (MFCs) have been demonstrated as a renewable energy strategy to efficiently recover chemical energy stored in wastewater into clean electricity, yet the limited power density ...limits their practical application. Here, Fe-doped carbon and nitrogen (Fe@CN) nanoparticles were synthesized by a direct pyrolysis process, which was further decorated to fabricate Fe@CN carbon paper anode. The modified Fe@CN anode with a higher electrochemically active surface area was not only benefit for the adhesion of electrochemically active microorganisms (EAMs) and extracellular electron transfer (EET) between the anode and EAMs but also selectively enriched
Geobacter
, a typical EAMs species. Accordingly, the MFCs with Fe@CN anode successfully achieved a highest voltage output of 792.76 mV and a prolonged stable voltage output of 300 h based on the mixed culture feeding with acetate. Most importantly, the electroactive biofilms on Fe@CN anode achieved more content ratio of proteins to polysaccharides (1.40) in extracellular polymeric substances for the balance between EET and cell protection under a harsh environment. This work demonstrated the feasibility of development on anode catalysts for the elaboration of the catalytic principle about interface modification, which may contribute to the practical application of MFC in energy generation and wastewater treatment.
The aim of this study was to develop an ultrasound consolidated score (UCS) in determining the activity of Crohn's disease (CD) and evaluate it with reference to simple endoscopic score (SES).
From ...June 2014 to June 2017, 66 patients with CD were retrospectively enrolled in this study. Each patient underwent endoscopy and transabdominal ultrasound (US) examination. The morphological symmetry, echogenicity of bowel wall, bowel wall layer structure, echogenicity of peri-bowel fat, bowel wall thickness (BWT), and Limberg type on power Doppler US were assessed with transabdominal US, and an UCS scoring system was developed based on these characteristics. Endoscopic results were used as the reference standard and SES was calculated to determine the CD activity. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance for determining CD activity and the correlation between UCS and SES was assessed using Spearman correlation analysis.
330 intestinal segments in 66 patients were included. The UCS of the segments in the remission phase ranged from 3.0 to 9.0 (mean, 3.6 ± 0.9) whereas in the active phase from 3.0 to 20.0 (mean, 10.6 ± 4.0) (p < 0.001). The cut-off value of UCS was 6. The associated area under ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.980, 88.3%, 95.5%, 93.8%, 91.3%, and 92.3%, respectively. The correlation coefficient between UCS and SES was 0.90, which was higher than the correlation coefficient of 0.83 between BWT and SES.
The newly developed UCS with transabdominal US has a good performance and potentially provides an effective alternative for evaluating the activity of CD.
UCS is an effective method to evaluate the activity of CD because it provides comprehensive information of the disease. Therefore, it could be employed as an alternative for diagnosis of CD.
The trade-off between intensity of hydrogen spillover and efficient production of aromatics poses an insurmountable obstacle to the depolymerization of lignin into monomeric phenols (MPs), as ...effectively harnessing hydrogen spillover for degradating lignin into MPs while avoiding excessive hydrogenation of aromatic rings remains a formidable challenge. Herein, a Ni–Cu/Nb2O5@Fe3O4 composite with Ni–Cu alloy and oxygen vacancies (OVs) has been fabricated for birch lignin valorization. The interspecies electron transfer within the alloy significantly improves intrinsic catalytic inertness of Cu species while simultaneously reducing intrinsic catalytic activity of Ni species toward moderate hydrogen spillover. Moreover, the mutual alloying of Ni and Cu generates moderately strong Lewis acidic sites (LASs). This resulting moderate hydrogen spillover and LASs collaboratively promote the depolymerization of lignin into crude MPs with varying degrees of methoxy substituents. Subsequently, the coupling of O atom-specific OVs recognition with LASs profoundly facilitates Ph–OMe bond dissociation, ultimately leading to the one-step generation of MPs. The tandem catalysis of moderate hydrogen spillover and specific recognition results in a high yield of MPs (up to 58 wt %) in birch lignin depolymerization, which is approximately twice as high as the reported optimum heterogeneous catalysts. Both experimental and calculation results suggest that the presence of Cu species induces an unusual electron-donating ability of Ni species during the alloying process, which successively reconstitutes their intrinsic catalytic performance and Lewis acid property, and the specific recognition of OVs is mediated by an O atom electron-effect, giving rise to a rare tandem catalysis for harvesting lignin based-MPs.
The construction of super-large tunnels generates various safety risks that can hamper the tunneling process and cause severe damages if not properly identified. This paper presents a case study on ...the identification and management of geological and environmental risks during the construction of the largest (a diameter of 15.8 m) slurry shield tunnel in China. Its ground conditions and settlement control were identified among the most challenging owing to a large area of mixed ground conditions, 11 fault zones and tunneling under residential areas and the city’s Metro Lines 1 and 9. In response to the severity of these risks and challenges, novel monitoring systems, ground treatment, and safety management technologies were successfully implemented throughout the tunneling process. Further, a technical framework was proposed in this study to serve as a risk management guidance for analogous tunneling operations.
Proofreading (editing) of mischarged tRNAs by cytoplasmic aminoacyl-tRNA synthetases (aaRSs), whose impairment causes neurodegeneration and cardiac diseases, is of high significance for protein ...homeostasis. However, whether mitochondrial translation needs fidelity and the significance of editing by mitochondrial aaRSs have been unclear. Here, we show that mammalian cells critically depended on the editing of mitochondrial threonyl-tRNA synthetase (mtThrRS, encoded by
), disruption of which accumulated Ser-tRNA
and generated a large abundance of Thr-to-Ser misincorporated peptides in vivo. Such infidelity impaired mitochondrial translation and oxidative phosphorylation, causing oxidative stress and cell cycle arrest in the G0/G1 phase. Notably, reactive oxygen species (ROS) scavenging by N-acetylcysteine attenuated this abnormal cell proliferation. A mouse model of heart-specific defective mtThrRS editing was established. Increased ROS levels, blocked cardiomyocyte proliferation, contractile dysfunction, dilated cardiomyopathy, and cardiac fibrosis were observed. Our results elucidate that mitochondria critically require a high level of translational accuracy at Thr codons and highlight the cellular dysfunctions and imbalance in tissue homeostasis caused by mitochondrial mistranslation.
Phosphorus (P) starvation leads to increased reutilization of cell wall P in rice (
). Carbon dioxide (CO
) is involved not only in plant growth and development but also in the response to abiotic ...stresses. However, it remains unclear whether CO
affects the reutilization of cell wall P in rice when subjected to P deficiency. In the present study, elevated CO
(600 μl·L
) significantly increased the soluble P content in shoots when compared with ambient CO
(400 μl·L
). This positive effect was accompanied by an increase of pectin content, as well as an increase of pectin methylesterase (PME) activity, which results in P release from the shoot cell wall, making it available for plant growth. P deficiency significantly induced the expression of phosphate transporter genes (
,
, and
) and decreased the P content in the xylem sap, but elevated CO
had no further effect, indicating that the increased soluble P content observed in shoots under elevated CO
is attributable to the reutilization of shoot cell wall P. Elevated CO
further increased the P deficiency-induced ethylene production in the shoots, and the addition of the ethylene precursor 1-amino-cyclopropane-1-carboxylic acid (ACC) mimicked this effect, while the addition of the ethylene inhibitor aminoethoxyvinylglycine (AVG) abolished this effect. These results further support the role of ethylene in the alleviation of P deficiency under elevated CO
. Taken together, our results indicate that the improvement of P nutrition in rice by elevated CO
is mediated by increasing the shoot cell wall pectin content and PME activity, possibly
the ethylene signaling pathway.
The frequent alternation between droughts and floods in the karst regions of Southwestern China has a serious impact on the ecological environment and socio-economic development. Although some ...high-resolution records for this region have been published, there is a lack of multi-proxy geological records that could be used to reconstruct the relationships between the changes in the Asian summer monsoon (ASM) and the regional hydrology and ecological environment since the Late Holocene. In this study, the history of the ASM from 3109 to 694 yr BP with a mean temporal resolution of 2.5 yr is reconstructed based on 47 high-precision 230Th dating results (mean 2-sigma error of ±14 yr), 959 pairs of δ18O/δ13C data, and multiple trace element analyses of a stalagmite from Shijiangjun (SJJ) Cave in the karst area of Southwestern China. The positive δ18O and δ13C excursions accurately recorded eight interdecadal-centennial weak summer monsoon events at ∼779, 1013–911, 1282–1172, 1736–1638, 1961–1864, 2472–2375, 2931–2818, and 3050–3014 yr BP. The cross-wavelet spectrum analysis of the δ18O and δ13C of stalagmite SJJ7 indicates that they have similar periods. The 7 yr period of the δ18O record was determined to have the maximum contribution rate (36.8%) to the periods using ensemble empirical mode decomposition (EEMD) analysis. In the Late Holocene, the weak ASM events were dominated by the southward shift of the Intertropical Convergence Zone (ITCZ) and the frequent El Niño events on an interdecadal-centennial timescale. The southward migration of the ITCZ lead to frequent El Niño events, and the resultant Hadley Circulation and Walker Circulation were weakened, leading to a weak ASM and changes in the hydrological conditions in the monsoon region. The δ13C values of the stalagmite changed relatively slowly compared with the δ18O values, which may indicate that the degradation and restoration of the regional ecological environment caused by abrupt changes in the climate is a relatively slow process. When the summer monsoon decreased, the stalagmite’s Mg/Ca and Sr/Ca ratios were relatively high due to CO2 degassing, and the prior calcite precipitation (PCP)/prior aragonite precipitation (PAP) increased in the karst zone. However, the Mg/Ca ratio increased and the Sr/Ca ratio rapidly decreased during the calcite deposition due to differences in the crystal structures and partition coefficients of aragonite and calcite. The dark layers in stalagmite SJJ7 correspond to transition from heavy to light δ18O values, reflecting the transition in the ASM. The pulsed increases in the elements (Mn, Fe, Al, and Si) in the dark layers reflect the stronger mechanical transport caused by more rainfall. The multi-proxy analysis of this stalagmite may reflect the interactions between the changes in the ASM and the atmosphere-hydrosphere-pedosphere-biosphere-lithosphere in the karst critical zone during the Late Holocene.
•Karst hydrology during Late-Holocene were inferred by multi-proxies in stalagmite.•The dark layers in the stalagmite correspond to the transition period of Asian summer monsoon from weak to strong.•Asian summer monsoon were dominated by the shift of the ITCZ and the ENSO events on the interdecadal-centennial timescale.
Huagaimu (
Manglietiastrum sinicum
) trees are critically endangered species and classified as a plant species with extremely small populations in China. Rhizospheres and bulk soils prokaryotic ...communities play an important role to protect and promote plants health and growth. However, the compositions and structures of prokaryotic communities in wild and reintroduced
M. sinicum
rhizospheres and bulk soils are still poorly understood. In the present study, prokaryotic communities in wild and reintroduced
M. sinicum
rhizospheres and bulk soils were compared using high-throughput sequencing. Thirty-two phyla, 76 classes, 193 orders, 296 families, and 470 genera of prokaryotes were obtained. Proteobacteria and Acidobacteria were the two most abundant phyla in all soil samples. The compositions and structures of prokaryotic communities were overall similar, and the abundance of some taxa varied significantly among soil samples. Soil prokaryotic communities were significantly affected by soil pH, total nitrogen, total phosphorus, and total potassium. Eleven of predicted functions were significantly different among the four soil groups. This study provides for the first insights into the compositions, structures, and potential functions of prokaryotic communities associated with wild and reintroduced
M. sinicum
rhizospheres and bulk soils, and providing a foundation for future research to help protect this endangered species.
High-Mg diorites with high Sr/Y ratios are commonly associated with metal mineralization. But their petrogenesis still remains controversial. Here we present a case study of the Early Cretaceous ...high-Mg dioritic intrusions (Fushan intrusive complex) in the Handan-Xingtai district, central North China Craton (NCC). Samples from the Fushan Complex (123±1 Ma) have SiO2 of 53.3–62.6 wt%, relatively variable K2O of 0.5–3.6 wt%, and high Mg# values (44–63). They show enrichment in light rare earth elements and depletion in heavy rare earth elements and high field strength elements, with high Sr/Y ratios and insignificant Eu anomalies, similar to those of adakitic rocks. For the Sr-Nd isotopes, they have whole-rock initial 87Sr/86Sr ratios and εNd(t=123 Ma) values ranging from 0.706564 to 0.707546 and from −16.1 to −12.8, respectively, which are distinct from those in the lower continental crust but similar to those in the contemporaneous mafic rocks in the study area. Because of these characteristics, together with their zircon δ18O values of 6.6‰±0.4‰, we suggest that the Fushan high-Mg dioritic complex was most likely formed by factional crystallization of mantle-derived basaltic magma. The high Sr/Y ratios could be achieved by the fractionation of amphibole crystals plus significant volumes of feldspars from a mafic magma. We suggest that late Mesozoic strong lithospheric extension and thinning, caused by the subduction of the paleo-Pacific slab in the east of the NCC, might have triggered the melting of the metasomatic lithospheric mantle to generate these intrusive complexes in the Handan-Xingtai district.
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