《Materials Today》2022

Liver failure is a fatal disease with a mortality rate of 80%. The only access to treat liver failure is invasive operation, which is restricted by limited donor sources or high costs. Thus, non-invasive medication for liver failure is urgently needed. Herein, we tried the first attempt to design a seed-inspired hydrogel with a micro-ecosystem, which imitates characteristics of seed with high intestinal adaptability, for the elimination of harmful metabolites in liver failure using a cascade reaction triggered by encapsulated microbes. Focusing on abnormal ammonia assimilation and intestinal oxygen metabolism, a two-component artificial microbiota was constructed to enable efficient intestinal oxygen consumption and subsequent hypoxia-induced ammonia elimination. More importantly, we imitated plant seeds with high adaptability to the intestinal environment to improve the performance of bacteria. A hydrogel particle with the seed shape, lignin coating, and porous structure, for achieving intentional retention, bacterial protection, and diffusion promotion, respectively was prepared. In murine and porcine models of liver failure, the artificial reactor lowered the blood ammonia to prevent nerve damage, and consumed oxygen to inhibit pathogenic facultative anaerobes for alleviating liver failure. This work underscores the great potential of medication with a bioinspired micro-ecosystem for liver failure.  相似文献   

    

《岩石力学与岩土工程学报(英文版)》2022,14(3):746-756

The dynamic frictional behaviors of natural discontinuities (joints, fractures, faults) play an important role in geohazards assessment; however, the mechanisms of the dynamic fault weakening/strengthening are still unclear. In this paper, a dynamic shear box was used to perform direct shear tests on saw-cut (planar) and natural (rough) granite fractures, with different normal load oscillation amplitudes. Based on the recorded shear forces and normal displacements, the shear forces, apparent friction coefficients and normal displacements are found to change periodically with oscillated normal loads and are characterized by a series of time shifts. The observed changing patterns are similar for the rough and planar fractures. Compared with the test data under constant normal load (CNL), small/large normal load oscillation amplitude enhances/reduces the peak shear strength, with a critical point. The magnitude of critical normal load oscillation for the rough fractures is smaller than the planer fractures. The results imply that dynamic fault weakening/strengthening can be achieved by both normal load oscillation amplitudes and slip surface topography. The rough fractures with larger normal oscillation amplitude can easily cause frictional weakening under stress disturbance.  相似文献   

    

Zhao Lu  Zhuang Jin  Panagiotis Kotronis 《岩石力学与岩土工程学报(英文版)》2022,14(1):169-179

Geological disasters such as slope failure and landslides can cause loss of life and property.Therefore,reproducing their evolution process is of great importance for risk assessment and mitigation.The recently developed SIMSAND critical state sand model combined with the smoothed particle hydrodynamics(SPH)method is adopted in this work to study slope failure under large deformations.To illustrate the efficiency and accuracy of the SIMSAND-SPH approach,a series of slope collapse studies using the discrete element method(DEM)considering various particle shapes(i.e.spherical,tetrahedral and elongated)is adopted as benchmarks.The parameters of the SIMSAND model are calibrated using DEM triaxial tests.In comparison to the DEM simulations,the runout distance and final slope height are well characterized with the SIMSAND-SPH approach with less computational cost.All comparisons show that the SIMSAND-SPH approach is highly efficient and accurate,which can be an alternative numerical tool to simulate real scale granular flow.  相似文献   

    

Zeqing Huang  Tongtiegang Zhao 《Wiley Interdisciplinary Reviews: Water》2022,9(2):e1580

Predictive performance is one of the most important issues for practical applications of ensemble hydroclimatic forecasts. While different forecasting studies tend to use different combinations of verification metrics and diagnostic plots, this paper presents a literature survey of popular verification metrics, diagnostic plots and their corresponding forecast attributes. Twenty metrics to quantify predictive performance of ensemble, deterministic and categorical forecasts are detailed; six types of diagnostic plots to visualize the relationship between ensemble forecasts and observations are presented; and the correspondence relationships of verification metrics and diagnostic plots with ten forecast attributes are illustrated. Numerical experiments are devised for raw ensemble precipitation forecasts generated by the Climate Forecast System version 2 (CFSv2) to illustrate the verification metrics, diagnostic plots and forecast attributes. The results suggest that verification metrics that pay attention to some similar attributes can be related to one another. Meanwhile, the metrics are not necessarily in full accordance as they tend to reflect different attributes. Time series plots visualize forecasts over a period of interest and graphically illustrate forecast bias, reliability and skill. Quantile range plots provide an overall diagnosis for the association of ensemble forecasts with observations. Overall, verification metrics can be illustrated by diagnostic plots for individual grid cells and also be screened by spatial plots at regional and global scales. The survey presented in this article can serve as a roadmap for the selection of verification metrics, diagnostic plots and forecast attributes for verifying ensemble hydroclimatic forecasts. This article is categorized under:

• Science of Water > Hydrological Processes

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Mei Zhang  Shuguang Jian  Zhengfeng Wang 《International journal of molecular sciences》2022,23(12)

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《International Journal of Electrical Power & Energy Systems》2016

The IPCC, a collection of 800 of the world’s leading climate change scientists, state that future climate related risks to society and infrastructure are likely to change. It is therefore important for the power industry to consider the possible impacts of future climate change on infrastructure performance. However, very few studies have been published to date examining the potential impacts of climate change on power distribution poles networks, which constitute large and valuable infrastructure assets worldwide. The work presented in this paper builds on the limited research in this area by developing a framework for examination of the possible impacts of climate change on timber power pole networks. The time-dependent event-based model developed herein allows network maintenance and predicted climate change effects to be considered, while also incorporating uncertainty associated with both climate change predictions, and structural reliability modelling of infrastructure networks over time. The results of a case study which examined notional power pole networks for five Australian cities revealed that the effects of climate change on predicted power pole performance can be significant. Wind failures for the Brisbane location were predicted to increase by approximately 60% when considering a period from 2015 to 2070, under the severe climate change scenario. However, the predicted impacts are also highly regionally variable, with one location considered experiencing positive climate change impacts for a medium climate change scenario.  相似文献   

    

《Advanced Powder Technology》2023,34(5):104007

Gas velocity is a key parameter regulating the particle size and the cooling rate of the gas atomized powder applied in additive manufacturing, metal injection molding, thermal spraying, and soft magnetic composites. In this paper, on basis of the well-designed close-coupled nozzles with different gas Mach numbers at the outlet, the gas field structure was simulated by Computational Fluid Dynamics (CFD) software, and the process of cooling and solidification of Fe-6.5 wt% Si metal droplets was calculated by finite difference method. The results show that with the increase of Mach number, both the gas velocity downstream and the pressure at the base of melt delivery tube tip rise, whereas the mass flow rate of the melt decreases. The nozzles with high Mach number can produce finer powder with higher cooling rate. The median diameter of the powder prepared by the nozzle with Mach numbers of 1.0, 1.5, 2.0, and 2.5 is 44.9, 39.0, 32.5, and 29.1 μm, respectively, and the corresponding cooling rate of the metal droplet with a diameter of 80 μm is 2.85 × 10⁴, 2.98 × 10⁴, 3.32 × 10⁴, and 3.50 × 10⁴ K/s, respectively. This work provides new ideas and suggestions for the preparation of metal powder with small particle size at high cooling rate.  相似文献   

    

《International Journal of Hydrogen Energy》2022,47(9):5807-5816

Hydrogen has been widely accepted as the best alternative energy carrier to store intermittent renewable energies. Proton exchange membrane water electrolysis (PEMWE) represents a promising technology to produce highly pure hydrogen with high efficiency and low footprint. While great progress has been made on components, materials and even fabrication processes, new materials or complicated processes still require refinement in the process of continuously improving PEMWE performance and durability. In this study, we demonstrate a facile treatment on membranes, aiming at improving cell performance at low costs. By adopting the hydration in DI water or 0.5 M H₂SO₄, or by varying the treatment sequence with the catalyst layer deposition, the PEMWE performance was tuned with the overpotential improvement as high as 50 mV at 2.0 A cm^?2. The PEMWE cells after different treatments were characterized both ex-situ and in-situ, and the mechanism was also proposed. The H₂SO₄ treatment swelled the micro micelle structure of the Nafion membranes, resulting in a higher proton conductivity and better cell performance compared with those from DI water treatment. In addition, the treatment sequence also had great impact, and the treatment after the catalyst layer deposition would result in better performance due to the reduced resistance and better kinetics. Not only the types of membrane, but also the thickness should be measured and reported when tested, which is more critical when compared across the published works from different groups. This work could also provide a guideline for future membrane treatment and PEMWE cell testing.  相似文献   

    

《International Journal of Hydrogen Energy》2020,45(51):26800-26811

H₂S is a kind of common impurity produced during the gasification of biomass, and it will poison the catalysts used in biomass tar steam reforming, leading to a rapid degradation on the catalytic performance. The purpose of this work is to investigate the characteristics of biomass tar steam reforming using Ni/perovskite catalysts with the presence of H₂S. Results show that H₂S could significantly reduce catalytic activity due to the adsorption of sulfur on Ni surface, and Ni/perovskite catalysts are less susceptible to this poisoning in comparison to the Ni-catalyst loaded on γ-Al₂O₃. To understand the mechanism, fresh and spent catalysts were characterized using various techniques of XRD, SEM-EDS, XPS and TPO. It is proved that the lattice oxygen in perovskite could transform into surface species, inhibit the adsorption of sulfur and thus benefit to the reactivity of catalysts during biomass tar steam reforming.  相似文献   

    

Zhong-Ji Qian  Mei-Fang Chen  Jiali Chen  Yi Zhang  Chunxia Zhou  Pengzhi Hong  Ping Yang 《Food Science & Nutrition》2021,9(3):1584-1602

Seahorse (Hippocampus kuda Bleeler) are representative marine species in aquaculture, with special value of medicine and food. In this study, the protective effects of two peptides from seahorse hydrolysates (SHP-1 and SHP-2) against ethanol-mediated oxidative stress in HepG2/CYP2E1 cells were investigated. Firstly, SHP-1 and SHP-2 presented no cytotoxicity. Compared with the ethanol-treated groups, SHP-1 and SHP-2 increased cell viability in a concentration-dependent manner. Secondly, SHP-1 and SHP-2 markedly reduced intracellular reactive oxygen species (ROS) generation, gamma-glutamyltranspeptidase (GGT) activity, and tumor necrosis factor-α (TNF-α) levels and remarkably enhanced superoxide dismutase (SOD) and glutathione (GSH) activities. SHP-1 and SHP-2 also down-regulated the expressions of GGT, bax, c-caspase-8/-9/-3, p-Akt, p-IκB-α, p-p65, p-ERK, and p-p38 but up-regulated SOD, GSH, NF-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and bcl-2 levels, as revealed by Western blot analysis. Moreover, SHP-1 and SHP-2 increased the mitochondrial membrane potential (MMP), reduced DNA damage, and suppressed the nuclear translocation of p65. These results suggest that two peptides from seahorse hydrolysates can be considered a potential functional biomaterial and further improve the use value of seahorse in aquaculture.  相似文献