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Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease globally. miRNAs (miRs) regulate various cellular events that lead to NAFLD. In this study we tested the hypothesis that miR-155 is an important regulator of steatohepatitis and fibrosis pathways. Wild type (WT) or miR-155 deficient (KO) mice received a high fat-high cholesterol-high sugar-diet (HF-HC-HS) for 34 weeks and liver tissues were analyzed. In patients with nonalcoholic steatohepatitis and in the mouse model of HF-HC-HS diet we found increased miR-155 levels in the liver compared to normal livers. Upon HF-HC-HS diet feeding, miR-155 KO mice displayed less liver injury, decreased steatosis, and attenuation in fibrosis compared to WT mice. ALT, triglyceride levels, and genes involved in fatty acid metabolic pathway were increased in WT mice whereas miR-155 KO mice showed attenuation in these parameters. HF-HC-HS diet-induced significant increase in the expression of NLRP3 inflammasome components in the livers of WT mice compared to chow fed diet. Compared to WT mice, miR-155 KO showed attenuated induction in the NLRP3, ASC, and caspase1 inflammasome expression on HF-HC-HS diet. Fibrosis markers such as collagen content and deposition, αSMA, Zeb2, and vimentin were all increased in WT mice and miR-155 KO mice showed attenuated fibrosis marker expression. Overall, our findings highlight a role for miR-155 in HF-HC-HS diet-induced steatosis and liver fibrosis.

Proton exchange membrane (PEM) fuel cell is a clean energy conversion device. Water management is one of the critical issues limiting the PEM fuel cell performance and service life. Liquid water impact on fuel cell surface significantly influences water transport and removal in the PEM fuel cell. In this study, a numerical investigation of water impact on the channel surface opposite to the GDL is carried out using the volume of fluid (VOF) method. The effects of impact velocity, droplet size, surface contact angle, temperature and impact angle on the water impact process are investigated. Water droplet impact on the wet flow channel surface is also considered. The results reveal that the water droplet experiences spreading and retraction stages in the impact process on a dry surface, determined by the interactions among the surface tension, inertial force and viscous force. Increasing the impact velocity, droplet size, surface hydrophilicity, temperature and impact angle lead to greater maximum water spreading factor on the surface. The water motion modes mainly include merging, crown-shaped jet flow and splashing on a wet surface, based on the magnitude of the impact velocity. The splashing is easier to occur for water droplet impact on a wet surface.

Background & Aims Rev-erbα represents a powerful transcriptional repressor involved in immunity. However, the regulation, function, and clinical relevance of Rev-erbα in Helicobacter pylori infection are presently unknown. Methods Rev-erbα was examined in gastric samples from H pylori-infected patients and mice. Gastric epithelial cells (GECs) were isolated and infected with H pylori for Rev-erbα regulation assays. Gastric tissues from Rev-erbα–/– and wild-type (littermate control) mice or these mice adoptively transferred with CD4+ T cells from IFN-γ–/– and wild-type mice, bone marrow chimera mice and mice with in vivo pharmacological activation or inhibition of Rev-erbα were examined for bacteria colonization. GECs, CD45+CD11c–Ly6G–CD11b+CD68– myeloid cells and CD4+ T cells were isolated, stimulated and/or cultured for Rev-erbα function assays. Results Rev-erbα was increased in gastric mucosa of H pylori-infected patients and mice. H pylori induced GECs to express Rev-erbα via the phosphorylated cagA that activated ERK signaling pathway to mediate NF-κB directly binding to Rev-erbα promoter, which resulted in increased bacteria colonization within gastric mucosa. Mechanistically, Rev-erbα in GECs not only directly suppressed Reg3b and β-defensin-1 expression, which resulted in impaired bactericidal effects against H pylori of these antibacterial proteins in vitro and in vivo; but also directly inhibited chemokine CCL21 expression, which led to decreased gastric influx of CD45+CD11c–Ly6G–CD11b+CD68– myeloid cells by CCL21-CCR7-dependent migration and, as a direct consequence, reduced bacterial clearing capacity of H pylori-specific Th1 cell response. Conclusions Overall, this study identifies a model involving Rev-erbα, which collectively ensures gastric bacterial persistence by suppressing host gene expression required for local innate and adaptive defense against H pylori., Graphical abstract

Obtaining a homogeneous distribution of interfacial layer in the Al/steel butt joint could further improve the tensile properties of well-formed joint, which is of great significance to the application of Al-steel hybrid structures in engineering. This article successfully used laser-metal inert-gas (MIG) hybrid welding-brazing technology to obtained 2-mm-thick 6061-T6 aluminum alloy and 301 stainless steel dissimilar metals butt joint. The penetration ability of the hybrid heat source was improved by increasing the laser power within an appropriate range. The interfacial layer with the most uniform thickness (4.5 μm–5.2 μm) and phase composition (τ5 phase and θ phase) could be obtained at laser power of 2000 W. Numerical simulation results revealed that reducing the difference of peak temperature along Al/steel interface could effectively improve the uniformity of the interfacial layer. The smallest difference of interfacial temperatures in the joint produced at laser power of 2000 W was responsible for the most uniform interfacial layer. The tensile strength of the Al/steel butt joint with the most uniform interfacial layer could reach the maximum value of 198 MPa (about 70 % of the 6061-T6 tensile strength).

2219 aluminium alloy is widely used in aerospace due to superior performance. However, the traditional welding technique of aluminium alloy has not satisfied the industrial demand because of poor welding quality. Plasma-MIG (metal inert gas) hybrid welding can effectively improve the joint quality by integrating the advantages of deep penetration in plasma arc welding and excellent filling ability in MIG welding. Nevertheless, its arc mechanism is still unclear due to the complicated action mode of hybrid arc. In order to further understand the essence of this advanced welding technology, we studied the arcs interaction mechanism through arc temperature, arc behaviour and droplet transfer models in Plasma-MIG hybrid welding. The results show that the arcs interaction will disperse the current, which makes the surface temperature gradient of hybrid arc small. The arcs interaction will enhance with the outer plasma current increasing, which improves the arc stability of hybrid arc. In short circuit transfer model, the voltage variation range will decrease and the stability of the transfer process will be improved owing to the arcs interaction. In globular transfer model, the arcs interaction facilitates the sustaining growth of droplet and reduces the transfer frequency. Now understanding the arcs interaction mechanism will promote the application of Plasma-MIG hybrid welding to address the welding issues of 2219 aluminium alloy.

Numerical calculations were conducted to explore the various effects of hydrogen blending on flame properties and soot behaviors in an ethylene coflow diffusion flame, based on a fully step-by-step decoupling method, by introducing several virtual species into the gas-phase mechanism. Results show that the concentration of OH increases under the chemical effect of hydrogen due to an enhanced rate of H2 + O ↔ OH + H. The soot yield, primary number density, and average primary number per aggregate decrease under dilution effect while these increase under chemical effect. The enhancements of hydrogen-abstraction-carbon-addition (HACA) rates and polycyclic aromatic hydrocarbon (PAH) condensation rates are responsible for soot mass addition under chemical effect. Both the oxidation rates by O2 and OH are delayed under the chemical effect because of lower concentrations of O2 and OH in the sooting zone. The overall effect of higher surface growth rates and delayed oxidation rates results in an increased soot volume fraction (SVF).

In this study, atmospheric and room temperature plasma and ultraviolet mutagenesis was studied for astaxanthin overproducing mutant. Phaffia rhodozyma mutant Y1 was obtained from the selection plate with 120 μmol/L diphenylamine as selection agent, and its carotenoid concentration and content were 54.38 mg/L and 5.38 mg/g, which were 19.02 % and 21.20 % higher than that of the original strain, respectively. Sugarcane bagasse hydrolysate was used for astaxanthin production by mutant Y1 at 22 °C and 220 rpm for 96 h, and the biomass and carotenoid concentration reached 12.65 g/L and 88.57 mg/L, respectively. Ultrasonication and cellulase were used to break cell wall and the parameters were optimized, achieving an astaxanthin extraction rate of 96.01 %. The present work provided a novel combined mutagenesis method for astaxanthin overproducing mutant and a green cell wall disruption process for astaxanthin extraction, which would play a solid foundation on the development of natural astaxanthin.

Product promotions and liberal return policies are two effective signals that can increase customers' repurchase behavior when online shopping, and how these signals work at different stages of market growth for various customer groups is an important topic for research and applications. Thus, to help online merchants make more effective decisions regarding the use of such signals, this paper proposes a multi-stage hidden Markov model (MS-HMM) to explore the motivational process behind customer repurchase behavior through the lens of the Signaling Theory. The customer-merchant relationship (CMR) is represented as the latent state in the hidden Markov model and is coupled with stage-heterogeneity in terms of state transition probabilities and state-dependent choice probabilities. Moreover, extensive experiments with real-world data are conducted to validate the effectiveness of the MS-HMM.

Hydrogels have attracted large attention in wastewater treatment fields due to their low-cost and good interaction with pollutants, among which novel double network hydrogel is an outstanding class. To expand the application of double network hydrogel in water treatment, in this study, eco-friendly physically cross-linked double network polymer hydrogel beads (DAP) are prepared and studied in depth on the mechanism of Methylene Blue (MB) adsorption; and then the polymer hydrogels are further functionalized by inorganic materials. MB adsorption on DAP favors alkaline condition which is due to the increase of electrostatic attraction and adsorption site, and it reaches equilibrium within 10 hr, which is faster than that of the single network hydrogel beads (SAP). Through thermodynamics study, the process shows to be an exothermic and spontaneous process. The adsorption isotherms are well fitted by Langmuir model, with a maximum monolayer adsorption capacity of 1437.48 mg/g, which is larger than SAP (1255.75 mg/g). After being functionalized with common inorganic materials including activated carbon, Fe3O4 and graphene oxide (GO), the composites show to have larger pore sizes and have obvious increases in adsorption capacity especially the one contains GO. Then the composites contains Fe3O4 are used as heterogeneous Fenton catalyst which shows to have excellent performance in MB degradation. The results indicate the potential of polymer double network to be functionalized in environmental areas.

This study introduced both steel slag and recycled aggregate aiming to improve the sustainability performance of self-compacting concrete (SCC). The study focused on investigating the effects of steel slag powder on the properties of self-compacting concrete with recycled aggregate (SCRAC). Recycled aggregates were used to replace 30% of natural coarse aggregates by volume. The effects of various replacement ratios of steel slag powder (SSP) to Portland cement (i.e., 10%, 20%, 30%, 40%, and 50%) on the workability, mechanical properties, and durability of SCRAC were studied. The results showed that SSP improved filling ability and passing ability of SCC, but adversely affected the segregation resistance. It was found that 10% replacement ratio of SSP to ordinary Portland cement (OPC) in SCRAC showed superior mechanical properties and higher durability performance in resisting chloride penetration and carbonation.

The scavenging process is helpful to suppress the super-knock in a 4-stroke turbocharged gasoline direct injection (GDI) engine because it can strengthen in-cylinder cooling and clear suspending residual particles from previous cycles. This paper investigates the effects of combustion system parameters on scavenging process. The simulation results showed that the piston pit with a shallow depth adjacent to the center of cylinder could intensify the scavenging motion and increase the velocity inside the pit, more residual gas and carbon particles could be therefore cleared. The intake and exhaust valve chamfer angle of 45° was beneficial to the scavenging process because more high-velocity scavenging motion occurred in piston pit and less fresh charge flowed into exhaust port directly. The injector location and ground electrode orientation has little influence on scavenging process because of its tiny volume. Finally, an optimum structural shape of combustion chamber was developed and proposed based on the research results.

In this study, a regenerable magnetic core-shell nanoparticles NH2-Fe3O4-NTA which include 3-aminopropyltriethoxysilane (APTES) and nitrilotriacetic acid (NTA) crosslinked to Fe3O4 was developed by one-pot method for simultaneous removal of cationic and anionic metals. Another nanocomposite NH2-Fe3O4-NTAII was prepared by multi-step method for comparison. NH2-Fe3O4-NTA had positive zeta potential values of 35.1–0.8 mV at pH 1.8–11.0, with the saturation magnetization and surface area up to 40.56 emu/g and 56.94 m2/g, respectively. The maximum sorption capacities of NH2-Fe3O4-NTA for cationic Cu (II) and anionic Sb (III) were 55.56 and 51.07 mg/L, respectively, which were superior to that of NH2-Fe3O4-NTAII. Based on screening in terms of characterization and metal sorption capacity, NH2-Fe3O4-NTA with a feasible synthesis scheme was chosen for further evaluation. The Cu (II) removal by NH2-Fe3O4-NTA was favored with increasing pH, while the Sb (III) removal preferred low pH (2–3). Simultaneous sorption of Cu (II) and Sb (III) exhibited same removal performance with the sole sorption under high dosage (>1 g/L). In real wastewater applications of NH2-Fe3O4-NTA, multiple metals in actual wastewater could be removed to well below the regulation levels. Nonspecific electrostatic interactions, inner-sphere complexation, ligand exchange, chelation and coordination complexation were responsible for Cu (II) and Sb (III) removal.