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ABSTRACTHuman induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) have been believed to be a promising alternative for the stem cell transplantation therapy. The exosomes (Exo) from iMSCs play an important role in several kinds of life activities. The role of exosomes from iMSCs in severe acute pancreatitis (SAP) induced myocardial injury (MI) has not been investigated. The Exo were isolated from iMSCs through differential centrifugation method. The SAP rat model was established with 5% sodium taurocholate injection into the distal end of the bilepancreatic duct. RT-PCR and western blotting were used to measure related gene expression. Masson trichrome and Sirius Red stainings were used to evaluate MI injury. Cardiac function was detected through cardiac ultrasound.Exo promoted cell viability through activating Akt/nuclear factor E2 related factors 2 (Nrf2)/heme oxygenase 1 (HO-1) signaling pathway in vitro. Exo improved MI induced by SAP through activating Akt/Nrf2/HO-1 signaling pathway. Exo improved cardiac function, and suppressed oxidative status in the SAP model. Exo increased the expression of von Willebrand Factor (vWF) and vascular endothelial growth factor (VEGF) through activating Nrf2/HO-1 signaling pathway. Our data indicated that the Exo from iMSCs could improve MI caused by SAP through activating Nrf2/HO-1 axis. These findings firstly unfold the potential application of Exo from iMSCs in treating MI induced by SAP.Abbreviations:LVEF: Left ventricular ejection fraction; LVFS: left ventricular fractional shorten; LVDd: left ventricular end-diastolic diameter; LVDs: left ventricular end-systolic diameter; MI: Myocardial infarction; MSCs: Mesenchymal stem cells; iPSCs: Human-induced pluripotent stem cells; SAP: Severe acute pancreatitis; iMSCs: iPSCs derived VEGF: MSCs; vascular endothelial growth factor; Nrf2: Nuclear factor erythroid 2-related factor; RT-PCR: Real-time polymerase chain reaction; HE: Hematoxylin-eosin; MODS: Multiple organ dysfunction syndrome; PI3K: Phosphatidylinositol 3-kinase; SOD: Superoxide dismutase; FBS: Fetal bovine serum; ECL: Enhanced chemiluminescence; IHC: Immunohistochemistry.

Hydrothermal carbonization (HTC) at 200 and 250 °C was combined with acetic acid and NaOH (changing feedwater pH from 2 to 12) to treat woody biomass for enhancing its pelletization and fuel properties. The treated biomass (hydrochar) was characterized by composition analysis and Fourier transform infrared spectroscopy, after which the energy consumption of pelletization; tensile strength; fuel properties, including proximate, elemental analysis, and mass density; and combustion characteristics of corresponding pellets were analyzed. The results showed that both the acetic acid and NaOH-aided HTC processes decreased the energy consumption of hydrochar compression. Weakly basic or acidic feedwater decreased the tensile strength of hydrochar pellets, but it increased at pH 2 and 12. The changes in treatment pH from 4 to 9 had little effect on the O/C and H/C content of the hydrochar pellets, while the addition of acetic acid enhanced oxygen and hydrogen loss more than NaOH. The heating values of hydrochar pellets produced at pH 2 from 200 and 250 °C were 20.7 and 22.8 MJ/kg, respectively. Hydrochar pellets produced from HTC at 250 °C and pH 2 had higher mass density and lower equilibrium water content than those produced under other conditions. The combustion process was promoted with reduced ignition temperature, maximum weight loss rate, and burnout temperature. These findings demonstrate that acetic acid-aided HTC of woody biomass was more suitable than NaOH for producing hydrochar pellets for use as a biofuel.

A low-cost material with high adsorption and oxidation ability for Hg0capture is needed, whereas it is hard to prepare by present methods. Here, halide ions (I–) and metal oxides (MnOxand ZrO2) were both loaded on peanut shells carbon to synthesize 6Mn-6Zr/PSC-I3. Various characterizations and experiments were used to investigate the physiochemical properties and Hg0removal performances. The sample exhibited an abundant pore structure and the active components dispersed well on its surface. The excellent total Hg0removal efficiency (more than 90%) was obtained in a wide reaction temperature range (150–300 °C) under a N2+ 6% O2atmosphere. Moreover, the Hg0adsorption capacity in 1440 min was 5587.0 μg·g–1and the Hg0oxidation efficiency after reaching adsorption equilibrium was more than 30%. Further, the reaction mechanism at 150 °C was proposed. The main chemical adsorption sites of carbon-iodine groups dominate Hg0removal at the initial reaction stage. As reaction progresses, chemical adsorption is weakened due to the gradual saturation of adsorption sites, whereas catalytic oxidation caused by lattice oxygen and hydroxyl oxygen substitutes chemical adsorption and dominates Hg0removal at the final reaction stage. Thus, the 6Mn-6Zr/PSC-I3 with economic and environmental benefits has a promising prospect in industrial applications.

In this study, the physical and chemical properties, combustion behaviors, kinetics, and the distribution of C, O, N, and S during different hydrothermal carbonization (HTC) temperatures of petrochemical sludge (PS) were investigated. The increase in HTC temperature is favorable to obtain higher organic-dissolved oil (ODO) content and less water-soluble oil (WSO) content. The solid conversion rate of hydrochar reached a maximum of 83.90% and comprehensive combustion performance is the best at 270 °C. The higher heating values (HHVs) value of hydrochar is stable at 21.00 MJ/kg. While the HHVs value range of ODO and WSO are 32.03–38.65 MJ/kg and 13.90–19.83 MJ/kg, respectively. Except for hard to occur WSO combustion stageⅢ, the Coats-Redfern integral method is well suited for kinetic simulations of all stages of hydrochar, WSO, and ODO. The long-chain alkanes, aromatic hydrocarbons, and cycloalkanes attach to the surface of the solid particles to form ODO and further convert to hydrochar via carbonization process. Nitrogen heterocycles, amines, and ketones remain in the feedwater to form WSO. Therefore, Carbon was maximally preserved in hydrochar and ODO, while N and S were removed by migration into WSO.

Removing NO from the air with a reusable material at room temperature is challenging. In this study, a series of urea–MnOx/ACF and urea–x(CeO2–(1 − x)MnO2)/ACF materials were prepared and used for removing NO at room temperature. The results showed that 10% urea–8% (0.5CeO2–0.5MnO2)/ACF yielded the highest NO conversion, which showed an NO conversion ratio above 90% with 1000 ppm NO in the initial mixed gases. Moreover, the NO conversion exceeded 98% when the NO concentration was 100 ppm in the initial mixed gases. More importantly, 10% urea–8% (0.5CeO2–0.5MnO2)/ACF was stable even after it was regenerated by reloading with urea, demonstrating that the material could be easily reused and its high performance was maintained. Finally, the mechanism and kinetics of the NO removal was discussed.

To provide insight into optimizing flue gas treatment, simultaneous removal of elemental mercury (Hg0) and NO using a CeO2modified V2O5–WO3/TiO2catalyst was investigated. The results show that a novel V2O5–WO3/TiO2–CeO2catalyst exhibits excellent Hg0oxidation efficiency (88%) and NO conversion efficiency (89%) at 250 °C. Furthermore, CeO2modified V2O5–WO3/TiO2not only exhibits enhanced catalytic activity but also good resistance in SO2and H2O. These catalysts were also characterized using BET, SEM, XRD, XPS, and H2-TPR. We found lower crystallinity, more reduced species and better texture properties to be presented, which were all ascribed to CeO2doping. Also, the redox cycle (V4++ Ce4+↔ V5++ Ce3+) plays a key role in promoting Hg0oxidation and NO conversion. In tune with the experimental results, a mechanism for the simultaneous removal of Hg0and NO was proposed for the V2O5–WO3/TiO2–CeO2catalysts.

Catalytic technologies present a more environmentally and financially sound option in the removal of elemental mercury (Hg0) from coal-fired flue gas. However, developing novel and efficient catalysts for Hg0oxidation is still a challenge. This paper reviews the catalytic oxidation of Hg0over a new kind of catalysts which were developed from selective catalytic reduction (SCR) catalysts of NOx. In this review, both noble metal catalysts and non-noble metal catalysts for Hg0oxidation were summarized. An overview of mercury emissions including transformation and speciation of mercury in coal-fired flue gas was also presented. The possible mechanisms and kinetics of mercury oxidation, space velocity and the effects of flue gas components on activity and stability of the catalysts were examined. We expect that this work will serve as a theoretical underpinning for the development of Hg0oxidation technology in flue gas.

Removing NOxby supported catalysts is important for industrial flue gases and exhaust fumes of diesel engines at low temperature (100–300 °C). However, it is still a challenge to develop the low-temperature catalyst (LTC) for selective catalytic reduction of NOx, especially at temperatures below 200 °C. This paper reviews the effect of the different carriers with different active centres. Most supported metal oxide catalysts are prepared by impregnation method. But under the same condition, catalysts perform better if they were prepared by sol–gel method. Also, this paper described and compared the research progress of reaction mechanism and kinetics of the supported catalysts which were used for the selective catalytic reduction of NOxat low temperature. There are different mechanisms because of the different reducing agents and active centres. The L–H and E–R mechanisms, or both of them coexisting, can explain the overall mechanism. In order to research the mechanism thoroughly, the exploration of the reactions of the surface chemical process may be a direction to develop low temperature supported catalysts for removing NOx.

Abstract: A series of CeO2 supported V2O5 catalysts with various loadings were prepared with different calcination temperatures by the incipient impregnation. The catalysts were evaluated for low temperature selective catalytic reduction (SCR) of NO with ammonia (NH3). The effects of O2 and SO2 on catalytic activity were also studied. The catalysts were characterized by specific surface areas (SBET) and X-ray diffraction (XRD) methods. The experimental results showed that NO conversion changed significantly with the different V2O5 loading and calcination temperature. With the V2O5 loading increasing from 0 to 10 wt%, NO conversion increased significantly, but decreased at higher loading. The optimum calcination temperature was 400°C. The best catalyst yielded above 80% NO conversion in the reaction temperature range of 160°C–300°C. The formation of CeVO4 on the surface of catalysts caused the decrease of redox ability.

Carbonaceous materials are considered to be effective materials for selective catalytic reduction (SCR) of NO, especially at room temperature. Carbonaceous materials can not only be used for adsorption applications due to their porosity properties but also can act as supports or reactants, which are globally available. This paper reviews the current state removal of NO by carbonaceous materials. Moreover, the characteristics of carbonaceous materials, mechanisms and kinetics of removal of NO by carbonaceous materials are also discussed. It is observed that carbonaceous material supported metal oxides can remove NO effectively at low temperature. Currently, removal of NO by carbonaceous materials at room temperature has been developed in the lab, but it is still in the research and development stage. In the future, three aspects of the work should be further studied, which is to extend the catalyst life, enhance the catalytic properties and reduce the cost of catalyst preparation. All the tasks are necessary for the practical application of NO removal technology at room temperature.