Background and Purpose
Gut microbiota dysbiosis induced by acute pancreatitis (AP) exacerbates pancreatic injury and systemic inflammatory responses. The alleviation of gut microbiota dysbiosis ...through faecal microbiota transplantation (FMT) is considered a potential strategy to reduce tissue damage and inflammation in many clinical disorders. Here, we aim to investigate the effect of gut microbiota and microbiota‐derived metabolites on AP and further clarify the mechanisms associated with pancreatic damage and inflammation.
Experimental Approach
AP rat and mouse models were established by administration of caerulein or sodium taurocholate in vivo. Pancreatic acinar cells were exposed to caerulein and lipopolysaccharide in vitro to simulate AP.
Key Results
Normobiotic FMT alleviated AP‐induced gut microbiota dysbiosis and ameliorated the severity of AP, including mitochondrial dysfunction, oxidative damage and inflammation. Normobiotic FMT induced higher levels of NAD+ (nicotinamide adenine dinucleotide)‐associated metabolites, particularly nicotinamide mononucleotide (NMN). NMN administration mitigated AP‐mediated mitochondrial dysfunction, oxidative damage and inflammation by increasing pancreatic NAD+ levels. Similarly, overexpression of the NAD+‐dependent mitochondrial deacetylase sirtuin 3 (SIRT3) alleviated the severity of AP. Furthermore, SIRT3 deacetylated peroxiredoxin 5 (PRDX5) and enhanced PRDX5 protein expression, thereby promoting its antioxidant and anti‐inflammatory activities in AP. Importantly, normobiotic FMT‐mediated NMN metabolism induced SIRT3–PRDX5 pathway activation during AP.
Conclusion and Implications
Gut microbiota‐derived NMN alleviates the severity of AP by activating the SIRT3–PRDX5 pathway. Normobiotic FMT could be served as a potential strategy for AP treatment.
This paper studies the global (in time) regularity and large time behavior of solutions to the 2D micropolar equations with only angular viscosity dissipation. Micropolar equations model a class of ...fluids with nonsymmetric stress tensor such as fluids consisting of particles suspended in a viscous medium. When there is no kinematic viscosity in the momentum equation, the global regularity problem is not easy due to the lack of suitable bounds on the derivatives. The idea here is to fully exploit the structure of the system and control the vorticity via the evolution equation of a combined quantity of the vorticity and the micro-rotation angular velocity. To understand the large time behavior, we overcome two main difficulties, the lack of kinematic viscosity and the presence of linear terms. Classical tools such as the Fourier splitting method of Schonbek and Kato's approach for the decay of small solutions do not apply here. We introduce a diagonalization process to eliminate the linear terms and rely on the uniform bounds for the first derivatives of the solutions to generate suitable decay rates.
Low n‐doping efficiency and inferior stability restrict the thermoelectric performance of n‐type conjugated polymers, making their performance lag far behind of their p‐type counterparts. Reported ...here are two rigid coplanar poly(p‐phenylene vinylene) (PPV) derivatives, LPPV‐1 and LPPV‐2, which show nearly torsion‐free backbones. The fused electron‐deficient rigid structures endow the derivatives with less conformational disorder and low‐lying lowest unoccupied molecular orbital (LUMO) levels, down to −4.49 eV. After doping, two polymers exhibited high n‐doping efficiency and significantly improved air stability. LPPV‐1 exhibited a high conductivity of up to 1.1 S cm−1 and a power factor as high as 1.96 μW m−1 K−2. Importantly, the power factor of the doped LPPV‐1 thick film degraded only 2 % after 7 day exposure to air. This work demonstrates a new strategy for designing conjugated polymers, with planar backbones and low LUMO levels, towards high‐performance and potentially air‐stable n‐type polymer thermoelectrics.
Stability: A new rigid coplanar poly(p‐phenylene vinylene) (PPV) derivative, LPPV‐1, is synthesized with a rigid planar backbone and low‐lying LUMO, which lead to reduced conformational disorder and high n‐type doping efficiency. The conductivity of LPPV‐1 is up to 1.1 S cm−1, and the power factor is only 2 % after a 7 day exposure to air. This work represents an effective strategy towards high‐performance and potentially air‐stable n‐type polymer thermoelectrics.
Inspired by the cubic Mn4CaO5 cluster of natural oxygen‐evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts, especially M4O4 cubane‐like clusters (M=transition ...metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M4O4 clusters, however, copper‐based molecular catalysts are poorly understood. Now, bio‐inspired Cu4O4 cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with a turnover frequency (TOF) of 267 s−1 for (LGly‐Cu)4 at 1.70 V and 105 s−1 for (LGlu‐Cu)4 at 1.56 V. Electrochemical and spectroscopic study revealed a successive two‐electron transfer process in the Cu4O4 cubanes to form high‐valent CuIII and CuIIIO. intermediates during the catalysis.
Cu4O4 cubanes show exceptional activity for electrocatalytic water oxidation in aqueous solution, with a turnover frequency of 267 s−1 for (LGly‐Cu)4 at 1.70 V and 105 s−1 for (LGlu‐Cu)4 at 1.56 V, respectively. The unique cuboidal structure and high catalytic performance is reminiscent of the natural Mn4CaO5 clusters in PS II.
Solution‐processable highly conductive polymers are of great interest in emerging electronic applications. For p‐doped polymers, conductivities as high a nearly 105 S cm−1 have been reported. In the ...case of n‐doped polymers, they often fall well short of the high values noted above, which might be achievable, if much higher charge‐carrier mobilities determined could be realized in combination with high charge‐carrier densities. This is in part due to inefficient doping and dopant ions disturbing the ordering of polymers, limiting efficient charge transport and ultimately the achievable conductivities. Here, n‐doped polymers that achieve a high conductivity of more than 90 S cm−1 by a simple solution‐based co‐deposition method are reported. Two conjugated polymers with rigid planar backbones, but with disordered crystalline structures, exhibit surprising structural tolerance to, and excellent miscibility with, commonly used n‐dopants. These properties allow both high concentrations and high mobility of the charge carriers to be realized simultaneously in n‐doped polymers, resulting in excellent electrical conductivity and thermoelectric performance.
Two conjugated polymers with rigid planar backbones, but with disordered crystalline structures, exhibit surprising structural tolerance to commonly used n‐dopants. These properties allow both high concentrations and high mobility of the charge carriers to be realized simultaneously in n‐doped polymers, resulting in excellent electrical conductivity of over 90 S cm−1 and thermoelectric performance up to 106 µW m−1 K−2.
The gut microbiota has been linked to cardiovascular diseases. However, the composition and functional capacity of the gut microbiome in relation to cardiovascular diseases have not been ...systematically examined. Here, we perform a metagenome-wide association study on stools from 218 individuals with atherosclerotic cardiovascular disease (ACVD) and 187 healthy controls. The ACVD gut microbiome deviates from the healthy status by increased abundance of Enterobacteriaceae and Streptococcus spp. and, functionally, in the potential for metabolism or transport of several molecules important for cardiovascular health. Although drug treatment represents a confounding factor, ACVD status, and not current drug use, is the major distinguishing feature in this cohort. We identify common themes by comparison with gut microbiome data associated with other cardiometabolic diseases (obesity and type 2 diabetes), with liver cirrhosis, and rheumatoid arthritis. Our data represent a comprehensive resource for further investigations on the role of the gut microbiome in promoting or preventing ACVD as well as other related diseases.The gut microbiota may play a role in cardiovascular diseases. Here, the authors perform a metagenome-wide association study on stools from individuals with atherosclerotic cardiovascular disease and healthy controls, identifying microbial strains and functions associated with the disease.
High‐spin conjugated radicals have great potential in magnetic materials and organic spintronics. However, to obtain high‐spin conjugated radicals is still quite challenging due to their poor ...stability. We report the successful synthesis and isolation of a stable triplet conjugated diradical, 10,12‐diaryldiindeno1,2‐b:2′,1′‐epyrazine (m‐DIP). With the m‐xylylene analogue skeleton containing electron‐deficient sp2‐nitrogen atoms, m‐DIP displays significant aromatic character within its pyrazine ring and its spin density mainly delocalizes on the meta‐pyrazine unit, making it a triplet ground state conjugated diradical. Our work provides an effective “spin density tuning” strategy for stable high‐spin conjugated radicals.
A stable triplet‐ground‐state conjugated diradical with pyrazine as a linker group was synthesized with a half‐life time of about 22 days under ambient conditions. The electron‐deficient pyrazine unit impedes spin delocalization to the peripheral phenyl rings, which increases the spin density distribution on the central meta‐pyrazine unit, leading to a large ΔES‐T.
One limitation of many battery charge equalizers is their slow equalization speed, especially when there are a large number of batteries in the series-string in high-voltage and high-power ...applications. This paper presents a new architecture for battery charge equalization. In this architecture, independent equalizers are placed in different layers and all the layers can equalize the corresponding batteries simultaneously, thus reducing equalization time by 50%. We explore the operation, performance characteristics, and the design of the architecture. Both simulation and experimental results are presented to validate the analysis in this paper.
Abstract
We assemble a large sample of 12,784 high-velocity stars with total velocity
V
GSR
≥ 300 km s
−1
, selected from RAVE DR5, SDSS DR12, LAMOST DR8, APOGEE DR16, GALAH DR2, and Gaia EDR3. In ...this sample, 52 are marginally hypervelocity star (HVS) candidates that have
V
GSR
exceeding their local escape velocities within 2
σ
confidence levels, 40 of which are discovered for the first time. All of the candidates are metal-poor, late-type halo stars, which are significantly different from the previously identified HVSs, which are largely massive early-type stars, discovered by extreme radial velocity. This finding suggests that our newly identified HVS candidates are ejected by different mechanisms from the previous population. To investigate their origins, for 547 extreme velocity stars with
V
GSR
≥ 0.8
V
esc
, we reconstruct their backward-integrated trajectories in the Galactic potential. According to the orbital analysis, no candidates are found to be definitely ejected from the Galactic-center (GC), while eight metal-poor extreme velocity stars are found to have a closest distance to the GC within 1 kpc. Intriguingly, 15 extreme velocity stars (including 2 HVS candidates) are found to have experienced close encounters with the Sagittarius dSph, suggesting that they originated from this dSph. This hypothesis is supported by an analysis of the
α
/Fe–Fe/H diagram. From a preliminary analysis of all of the 547 extreme velocity stars, we propose a general picture–star ejection from Galactic subsystems such as dwarf galaxies and globular clusters can be an important channel to produce extreme velocity stars or even HVSs, particularly the metal-poor late-type halo population.
Soil bacteria play a key role in the ecological and evolutionary responses of agricultural ecosystems. Domestic herbivore grazing is known to influence soil bacterial community. However, the effects ...of grazing and its major driving factors on soil bacterial community remain unknown for different plant community compositions under increasing grazing intensity. Thus, to investigate soil bacterial community diversity under five plant community compositions (Grass; Leymus chinensis; Forb; L. chinensis & Forb; and Legume), we performed a four-year field experiment with different grazing intensity treatments (no grazing; light grazing, 4 sheep·ha-1; and heavy grazing, 6 sheep·ha-1) in a grassland in China. Total DNA was obtained from soil samples collected from the plots in August, and polymerase chain reaction (PCR) analysis and denaturing gradient gel electrophoresis (DGGE) fingerprinting were used to investigate soil bacterial community. The results showed that light grazing significantly increased indices of soil bacterial community diversity for the Forb and Legume groups but not the Grass and L. chinensis groups. Heavy grazing significantly reduced these soil bacterial diversity indices, except for the Pielou evenness index in the Legume group. Further analyses revealed that the soil N/P ratio, electrical conductivity (EC), total nitrogen (TN) and pH were the major environmental factors affecting the soil bacterial community. Our study suggests that the soil bacterial community diversity was influenced by grazing intensity and plant community composition in a meadow steppe. The present study provides a baseline assessment of the soil bacterial community diversity in a temperate meadow steppe.
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