Quantum Hall systems host chiral edge states extending along the one-dimensional boundary of any two-dimensional sample. In solid state materials, the edge states serve as perfectly robust transport ...channels that produce a quantized Hall conductance; due to their chirality, and the topological protection by the Chern number of the bulk band structure, they cannot be spatially localized by defects or disorder. Here, we show experimentally that the chiral edge states of a lossy quantum Hall system can be localized. In a gyromagnetic photonic crystal exhibiting the quantum Hall topological phase, an appropriately structured loss configuration imparts the edge states' complex energy spectrum with a feature known as point-gap winding. This intrinsically non-Hermitian topological invariant is distinct from the Chern number invariant of the bulk (which remains intact) and induces mode localization via the "non-Hermitian skin effect." The interplay of the two topological phenomena-the Chern number and point-gap winding-gives rise to a non-Hermitian generalization of the paradigmatic Chern-type bulk-boundary correspondence principle. Compared to previous realizations of the non-Hermitian skin effect, the skin modes in this system have superior robustness against local defects and disorders.
The commonly used Pt/C catalyst has low durability for oxygen reduction reaction (ORR). In this work, CNT-supported TiO2 nanoparticles, which synergistically combines the merits of TiO2 (high ...stability and strong interactions with the supported Pt nanoparticles) and CNT (high specific surface area and large electrical conductivity), are prepared by a sol-gel process coupled with an annealing process and used as the support for Pt nanoparticles, which are anchored around TiO2 nanoparticles by a photodeposition technique. The as-synthesized Pt/TiO2@CNT catalyst exhibits a mass activity 5.3 times as large as that of the commercial Pt/C catalyst (0.358 A mgPt−1 vs. 0.067 A mgPt−1 at 0.9 V) and an excellent stability (no activity loss after 10000 potential cycles) for ORR, which can be mainly attributed to the lower oxygen adsorption energy of Pt, resulting from the strong metal-support interaction induced by the deposition of Pt nanoparticles around the well-dispersed TiO2 nanoparticles on CNT.
•CNT-supported TiO2 particles synergistically combines the merits of TiO2 and CNT.•Pt particles are anchored around TiO2 nanoparticles by a photodeposition process.•Pt/TiO2@CNT exhibits a mass activity 4.3 times higher than that of Pt/C.•Pt/TiO2@CNT exhibits no activity loss after 10000 potential cycles.
To synthesize highly dispersed Ru nanoparticles (NPs) with desired particle size for NH3 decomposition, an appropriate support is crucial. Herein, spherical mesoporous silica (SMS) NPs with ∼3 nm ...pores are synthesized by a microwave-assisted evaporation-induced self-assembly method and used as support of Ru NPs for NH3 decomposition. Characterization shows that compared to Ru NPs supported on SBA-15 and fumed SiO2, Ru NPs supported on SMS (Ru@SMS) exhibit superior NH3 decomposition performance, achieving a hydrogen generation rate of 31.4 mmol·g-1 cat·min−1 at 500 °C, which is one of the highest reported values for supported Ru catalysts in NH3 decomposition. The excellent NH3 decomposition performance observed on Ru@SMS should be attributed to effective dispersion and appropriate particle size (2.22 ± 0.29 nm) of Ru NPs. This work highlights the potential of SMS as support of Ru catalyst in NH3 decomposition.
•SMS NPs with ∼3 nm pores are synthesized by a microwave-assisted EISA method.•The highly dispersed Ru NPs have mean particle size of 2.22 ± 0.29 nm.•Ru@SMS achieves a hydrogen generation rate of 31.4 mmol·g-1 cat·min−1 at 500 °C.•Ru@SMS shows a marginal decrease in NH3 conversion over a 128-h period.
The paper presents the uncertainty hull form optimization design method for minimum EEOI, considering the influence of travelling speed perturbation. Four types of perturbation parameters are ...addressed and applicable methods for each type are given. Firstly, uncertainty optimization methods: Interval optimization (IO) and robust optimization under moment uncertainty (DRO-MU) are introduced. Then, formula and parameters of EEOI with the numerical method for calculating resistance are described. Finally, hull form optimization model of minimum EEOI is given and four case studies are conducted to verify the feasibility and superiority of the novel approach. Results show that the uncertainty optimization design is of excellent adaptability and reliability in minimum EEOI ship hull lines design.
•Ship hull form optimization design is conducted for find a minimum EEOI.•Four types of perturbation parameter are introduced: constant, interval, probability and interval probability.•Four kinds of optimization method are conducted for each type of parameter.•All the uncertainty optimization methods have the effectiveness and superiority.
The Pearl River Delta (PRD) of China, which has a population of more than 58 million people, is one of the largest agglomerations of cities in the world and had severe PM2.5 pollution at the ...beginning of this century. Due to the implementation of strong pollution control in recent decades, PM2.5 in the PRD has continuously decreased to relatively lower levels in China. To comprehensively understand the current PM2.5 sources in the PRD to support future air pollution control strategies in similar regions, we performed regional-scale PM2.5 field observations coupled with a state-of-the-art source apportionment model at six sites in four seasons in 2015. The regional annual average PM2.5 concentration based on the 4-month sampling was determined to be 37 µg m−3, which is still more than 3 times the WHO standard, with organic matter (36.9 %) and SO42- (23.6 %) as the most abundant species. A novel multilinear engine (ME-2) model was first applied to a comprehensive PM2.5 chemical dataset to perform source apportionment with predetermined constraints, producing more environmentally meaningful results compared to those obtained using traditional positive matrix factorization (PMF) modeling. The regional annual average PM2.5 source structure in the PRD was retrieved to be secondary sulfate (21 %), vehicle emissions (14 %), industrial emissions (13 %), secondary nitrate (11 %), biomass burning (11 %), secondary organic aerosol (SOA, 7 %), coal burning (6 %), fugitive dust (5 %), ship emissions (3 %) and aged sea salt (2 %). Analyzing the spatial distribution of PM2.5 sources under different weather conditions clearly identified the central PRD area as the key emission area for SO2, NOx, coal burning, biomass burning, industrial emissions and vehicle emissions. It was further estimated that under the polluted northerly air flow in winter, local emissions in the central PRD area accounted for approximately 45 % of the total PM2.5, with secondary nitrate and biomass burning being most abundant; in contrast, the regional transport from outside the PRD accounted for more than half of PM2.5, with secondary sulfate representing the most abundant transported species.
Abstract
Background
Peritoneal dialysis (PD) remains limited due to dialysis failure caused by peritoneal fibrosis. Tamoxifen (TAM), an inhibitor of estrogen receptor 1 (ESR1), has been reported to ...treat fibrosis, but the underlying mechanism remains unknown. In this study, we sought to explore whether tamoxifen played an anti-fibrotic role by affecting transcription factor ESR1.
Methods
ESR1 expression was detected in the human peritoneum. Mice were daily intraperitoneally injected with 4.25% glucose PD dialysate containing 40 mM methylglyoxal for 2 weeks to establish PD-induced peritoneal fibrosis. Tamoxifen was administrated by daily gavage, at the dose of 10 mg/kg. Chromatin immunoprecipitation (ChIP) and dual‐luciferase reporter assay were performed to validate ESR1 bound
H19
promoter. Gain-of-function and loss-of-function experiments were performed to investigate the biological roles of H19 on the mesothelial-mesenchymal transition (MMT) of human peritoneal mesothelial cells (HPMCs). Intraperitoneal injection of nanomaterial-wrapped 2′-
O
-Me-modified small interfering RNA was applied to suppress H19 in the mouse peritoneum. RNA immunoprecipitation and RNA pull-down assays demonstrated binding between H19 and p300. Exfoliated peritoneal cells were obtained from peritoneal dialysis effluent to analyze the correlations between ESR1 (or H19) and peritoneal solute transfer rate (PSTR).
Results
ESR1 was increased significantly in the peritoneum after long-term exposure to PD dialysate. Tamoxifen treatment ameliorated high glucose-induced MMT of HPMCs, improved ultrafiltration rate, and decreased PSTR of mouse peritoneum. Tamoxifen reduced the H19 level by decreasing the ESR1 transcription of
H19
. Depletion of H19 reversed the pro-fibrotic effect of high glucose while ectopic expression of H19 exacerbated fibrotic pathological changes. Intraperitoneal injection of nanomaterial-wrapped 2′-
O
-Me-modified siRNAs targeting H19 mitigated PD-related fibrosis in mice. RNA immunoprecipitation (RIP) and RNA pull-down results delineated that H19 activated VEGFA expression by binding p300 to the
VEGFA
promoter and inducing histone acetylation of the
VEGFA
promoter. ESR1 and H19 were promising targets to predict peritoneal function.
Conclusions
High glucose-induced MMT of peritoneal mesothelial cells in peritoneal dialysis via activating ESR1. In peritoneal mesothelial cells, ESR1 transcribed the
H19
and H19 binds to transcription cofactor p300 to activate the
VEGFA
. Targeting ESR1/H19/VEGFA pathway provided new hope for patients undergoing peritoneal dialysis.
Graphic Abstract
Caroli disease is a rare congenital malformation that predisposes to segmental cystic dilatation of the intrahepatic bile ducts. Banti syndrome is characterized by persistent splenomegaly due to ...chronic congestion, resulting in a low hematocrit and ultimately leading to pancytopenia. In this report, we describe a 29-year-old woman who presented with a >20-year history of hepatitis B surface antigen positivity and a >1-year history of recurrent fatigue and malaise. On examination, the patient had abdominal distension with marked splenomegaly (7 cm below the ribs) and ascites with tenderness of the abdominal muscles to palpation. A complete blood count showed a low white blood cell count, red blood cell count, and hemoglobin concentration. During the course of treatment, the patient developed multiple symptoms of pancytopenia and concomitant splenomegaly, and she was discharged after total splenectomy with good recovery. The combination of Banti syndrome and Caroli disease results in severe symptoms of portal hypertension.
Carbon nanofibers (CNFs) with different content of surface functional groups which are carboxyl groups (CNF–OX), carbonyl groups (CNF–CO) and hydroxyl groups (CNF–OH) and nitrogen-containing groups ...(CNF–ON) are synthesized, and their electrocatalytic activities toward oxygen reduction reaction (ORR) in alkaline solution are investigated. The result of X-ray photoelectron spectroscopy (XPS) characterization indicates that a higher concentration of carboxyl groups, carbonyl groups and hydroxyl groups are imported onto the CNF–OX, CNF–CO and CNF–OH, respectively. Cyclic voltammetry shows that both the oxygen- and nitrogen-containing groups can improve the electrocatalytic activity of CNFs for ORR. The CNF–ON/GC electrode, which has nitrogen-containing groups, exhibits the highest current density of ORR. Rotating disk electrode (RDE) characterization shows that the oxygen reduction on CNF–ON/GC electrode proceeds almost entirely through the four-electron reduction pathway, the CNF–OX/GC, CNF–CO/GC and CNF–OH/GC electrodes proceed a two-electron reduction pathway at low potentials (−0.2 V to −0.6 V) followed by a gradual four-electron reduction pathway at more negative potentials, while the untreated carbon nanofiber (CNF–P/GC) electrode proceeds predominantly by a two-electron reduction pathway within the whole range of potential studied.
► Different surface functional groups were successfully imported onto CNF surface. ► CNF–ON exhibited the highest ORR activity, followed by CNF–OX, CNF–CO and CNF–OH. ► CNF–ON could catalyze ORR through the 4e− pathway.
We show the effects of chlorine incorporation in the crystallization process of perovskite film based on a lead acetate precursor. We demonstrate a fabrication process for fast grain growth with ...highly preferred {110} orientation upon only 5 min of annealing at 100 °C. By studying the correlation between precursor composition and morphology, the growth dynamic of perovskite film in the current system is discussed. In particular, we found that both lead acetate precursor and Cl incorporation are beneficial to perovskite growth. While lead acetate allows fast crystallization process, Cl improves perovskite crystallinity. Planar perovskite solar cells with optimized parameters deliver a best power conversion efficiency of 15.0% and average efficiency of 14.0% with remarkable reproducibility and good stability.
In this work, a kinetics‐integrated CFD model based on coupling computational fluid dynamics (CFD) and biokinetic was developed to guide the industrial scale‐up for fermentation of docosahexaenoic ...acid (DHA). Two‐substrate biokinetic equations for a 5 L bioreactor with oxygen and nitrogen source as limiting substrates were established, which were further coupled with CFD to simulate the biomass growth and lipid accumulation as well as flow field environment in the fermentation process. The coupled CFD‐biokinetic model can accurately reflect the changes of each relevant variable in the 50 L bioreactor under different operating conditions. The optimal working conditions of a 35 m3 bioreactor were predicted by this model and have secured the one‐step scale‐up of DHA fermentation, resulting in a biomass, lipid concentration, and DHA content in lipids of 99.2 g/L, 55.7 g/L, and 52.5%, respectively. This study thus provides an effective strategy for rapid industrial scale‐up of DHA production.
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