Brain entropy changes in classical trigeminal neuralgia

BackgroundClassical trigeminal neuralgia (CTN) is a common and severe chronic neuropathic facial pain disorder. The pathological mechanisms of CTN are not fully understood. Recent studies have shown that resting-state functional magnetic resonance imaging (rs-fMRI) could provide insights into the functional changes of CTN patients and the complexity of neural processes. However, the precise spatial pattern of complexity changes in CTN patients is still unclear. This study is designed to explore the spatial distribution of complexity alterations in CTN patients using brain entropy (BEN).MethodsA total of 85 CTN patients and 79 age- and sex-matched healthy controls (HCs) were enrolled in this study. All participants underwent rs-fMRI and neuropsychological evaluations. BEN changes were analyzed to observe the spatial distribution of CTN patient complexity, as well as the relationship between these changes and clinical variables. Sixteen different machine learning methods were employed to classify the CTN patients from the HCs, and the best-performing method was selected.ResultsCompared with HCs, CTN patients exhibited increased BEN in the thalamus and brainstem, and decreased BEN in the inferior semilunar lobule. Further analyses revealed a low positive correlation between the average BEN values of the thalamus and neuropsychological assessments. Among the 16 machine learning methods, the Conditional Mutual Information Maximization-Random Forest (CMIM-RF) method yielded the highest area under the curve (AUC) of 0.801.ConclusionsOur study demonstrated that BEN changes in the thalamus and pons and inferior semilunar lobule were associated with CTN and machine learning methods could effectively classify CTN patients and HCs based on BEN changes. Our findings may provide new insights into the neuropathological mechanisms of CTN and have implications for the diagnosis and treatment of CTN

Characteristics of Sedimentary Organic Matter in Tidal Estuaries: A Case Study from the Minjiang River Estuary

As one of the main interfaces of the Earth system, estuaries show the strongest land–sea interaction in the carbon cycle, which links terrestrial ecosystems to the marginal sea. Furthermore, estuaries are considered as one of the most active intermediate reservoirs for both terrestrial and marine matter due to complex hydrodynamic processes regulated by the river runoff, wave and tide. Processing of organic matter (OM) in tidal estuaries modifies its transfer and transformation from the river to the sea, so studies of on the source and distributions of estuarine OM can help us understand the behavior of production, exchange, transport and burial of diverse OM within this transition zone before entering the marginal sea. In this paper, we took the Minjiang River Estuary (MRE) as a typical system in which there is strong influence of the tide. The source, composition and spatial distribution of OM in surface sediments of MRE were deciphered based on multiple organic geochemical properties for source-specific biomarkers (n-alkanes, n-alkanols, sterols) and bulk OM. Results show that sedimentary organic components were negatively correlated with sediment grain size, which indicates fine particles such as silt and clay are the major carriers of the OM signals in tidal estuaries. Source-specific biomarker proxies indicate that in terms of source diversity the sedimentary OM in the MRE shows mixed signals of terrestrial and marine sources, and the proportion of terrestrial OM decreases with the increase in distance from the land. The fractional contributions of OM from the riverine (i.e., terrestrial), marine and deltaic sources were quantitatively estimated using a Monte Carlo (MC) three-end-member mixing model based on C/N and δ13C values, and the average contributions of the three sources are 40 ± 10%, 48 ± 10% and 12 ± 4%, respectively, with little contribution from deltaic sources. The dispersion of sedimentary OM from different sources in the MRE is primarily controlled by the depositional environment determined by dynamic conditions and tidal processes play a significant role in the redistribution of sedimentary OM dispersion patterns. Compared with other large estuaries in southeast China, the OM accumulation contribution in the tide dominated small and medium-sized estuaries such as the MRE which is largely dependent on riverine and marine deliveries. The MRE has a high potential for both terrestrial and marine organic carbon (OC) burial, with an accumulation rate of 3.39 ± 1.83 mg cm−2 yr−1 for terrestrial OC, and an accumulation rate of 3.18 ± 0.68 mg cm−2 yr−1 for marine OC in muddy sediment, making it an important contributor to the sedimentary carbon sink of the marginal sea

Bio-Inspired Aerobic-Hydrophobic Janus Interface on Partially Carbonized Iron Heterostructure Promotes Bifunctional Nitrogen Fixation.

Competition from hydrogen/oxygen evolution reactions and low solubility of N2 in aqueous systems limited the selectivity and activity on nitrogen fixation reaction. Herein, we design an aerobic-hydrophobic Janus structure by introducing fluorinated modification on porous carbon nanofibers embedded with partially carbonized iron heterojunctions (Fe3 C/Fe@PCNF-F). The simulations prove that the Janus structure can keep the internal Fe3 C/Fe@PCNF-F away from water infiltration and endow a N2 molecular-concentrating effect, suppressing the competing reactions and overcoming the mass-transfer limitations to build a robust "quasi-solid-gas" state micro-domain around the catalyst surface. In this proof-of-concept system, the Fe3 C/Fe@PCNF-F exhibits excellent electrocatalytic performance for nitrogen fixation (NH3 yield rate up to 29.2 μg h-1  mg-1 cat. and Faraday efficiency (FE) up to 27.8 % in nitrogen reduction reaction; NO3 - yield rate up to 15.7 μg h-1  mg-1 cat. and FE up to 3.4 % in nitrogen oxidation reaction)