62 research outputs found
Experimental Study on the Deactivating Effect of KNO 3
Nanosized Ce/TiO2 is effective in selective catalytic reduction of NO with NH3. The NO conversion of Ce/TiO2 is 93% at 370°C. However, addition of potassium using KNO3, KCl, or K2SO4 as precursors effectively deactivates Ce/TiO2. NO conversion at 370°C is reduced to 45%, 24%, and 16% after addition of KNO3, KCl, and K2SO4, respectively, with a controlled K/Ce molar ration at 0.25. The deactivation may be attributed to the changes in the structural and chemical state of ceria and the degradation of surface acidity. The transformation of amorphous ceria into ceria crystals after potassium addition, together with the decrease of surface defects, is also determined. Oxygen diffusion in the process of ceria reduction is slow, and the redox cycle is slowed down. Moreover, the surface acid sites are markedly destroyed, leading to the reduced capacity of ammonia adsorption. These results may provide useful information for the application and life management of CeO2/TiO2 in potassium-rich environments such as biofuel-fired boilers
Synthesis and Characterization of Pyrochlore Bi 2
Praseodymium doped Bi2Sn2O7 (BSO), as a visible-light responsive photocatalyst, was prepared by a hydrothermal method with different dopant contents. The as-prepared photocatalysts were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N2 adsorption-desorption isotherm, X-ray photoelectron spectroscopy analysis (XPS), and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of prepared catalysts was evaluated by the degradation of Rhodamine Bextra (RhB) and 2,4-dichlorophenol (2,4-DCP) in aqueous solution under visible light irradiation. It was found that Pr doping inhibited the growth of crystalline size and the as-prepared materials were small in size (10–20 nm). In our experiments, Pr-doped BSO samples exhibited enhanced visible-light photocatalytic activity compared to the undoped BSO, and the optimal dopant amount of Pr was 1.0 mol% for the best photocatalytic activity. On the basis of the calculated PL spectra, the mechanism of enhanced photocatalytic activity has been discussed
Ube2L6 promotes M1 macrophage polarization in HFD-fed obese mice via ISGylation of STAT1 to trigger STAT1 activation
Introduction: In obesity-related type 2 diabetes mellitus (T2DM), M1 macrophages aggravate chronic inflammation and insulin resistance. ISG15-conjugation enzyme E2L6 (Ube2L6) has been demonstrated as a promoter of obesity and insulin resistance. This study investigated the function and mechanism of Ube2L6 in M1 macrophage polarization in obesity.
Methods: Obesity was induced in Ube2L6AKO mice and age-matched Ube2L6flox/flox control mice by high-fat diet (HFD). Stromal vascular cells (SVCs) were isolated from epididymal white adipose tissue of mice. Polarization induction was performed in mouse bone marrow-derived macrophages (BMDMs) by exposure to IFN-γ, lipopolysaccharide (LPS), or IL-4. F4/80 expression was assessed by immunohistochemistry staining. Expression of M1/M2 macrophage markers and target molecules was determined by flow cytometry, RT-qPCR, and Western blotting, respectively. Protein interaction was validated by co-immunoprecipitation (Co-IP) assay. The release of TNF-α and IL-10 was detected by ELISA.
Results: The polarization of pro-inflammatory M1 macrophages together with an increase in macrophage infiltration were observed in HFD-fed mice, which could be restrained by Ube2L6 knockdown. Additionally, Ube2L6 deficiency triggered the repolarization of BMDMs from M1 to M2 phenotypes. Mechanistically, Ube2L6 promoted the expression and activation of signal transducer and activator of transcription 1 (STAT1) through interferon-stimulated gene 15 (ISG15)-mediated ISGlylation, resulting in M1 macrophage polarization.
Conclusion: Ube2L6 exerts as an activator of STAT1 via post-translational modification of STAT1 by ISG15, thereby triggering M1 macrophage polarization in HFD-fed obese mice. Overall, targeting Ube2L6 may represent an effective therapeutic strategy for ameliorating obesity-related T2DM
3-D health trajectories and related childhood predictors among older adults in China
AbstractThis study aimed to identify the multi-trajectories of 3-D health of older adults in China and to explore whether the childhood predictors are associated with 3-D health trajectory. Data came from five waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011 to 2018). A multi-trajectory modeling approach was carried out to jointly estimate the trajectories of 3-D health. A multinomial regression model was used to investigate the relationships between childhood predictors and the joint trajectories. We identified three typical joint 3-D health trajectories. Female, childhood health, maternal and paternal educations, childhood friendships, family and neighborhood predictors could all affect 3-D health trajectories of older adults directly or indirectly through adult variables. The 3-D health trajectories showed increasing trends, thus the government should perform more interventions toward the childhood predictors for better health of older adults.</jats:p
3-D Health Trajectories and Related Childhood Predictors Among Older Adults in China
Abstract
Objectives: This study aimed to identify the multi-trajectories of 3-D health of older adults in China and to explore whether the childhood predictors are associated with 3-D health trajectory. Methods: Data came from five waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011 to 2018). A multi-trajectory modeling approach was carried out to jointly estimate the trajectories of 3-D health. A multinomial regression model was used to investigate the relationship between childhood predictors and the joint trajectories. Results: We identified three typical joint 3-D health trajectories. Female, childhood health, maternal and paternal educations, childhood friendships, family and neighborhood predictors could all affect disability trajectories of older adults directly or indirectly through adults variables. Discussion: The 3-D health trajectories showed increasing trends, thus the government should perform more interventions toward the childhood predictors for better health of older adults.</jats:p
CdS nanorod arrays with TiO2 nano-coating for improved photostability and photocatalytic activity
CdS nanorod arrays were grown on fluorine-doped tin oxide glass substrates via a hydrothermal process and subsequently coated with a TiO2 nanolayer via a vacuum dip-coating process to fabricate a onedimensional array structured photocatalyst. The TiO2 nanolayer improved the photocatalytic efficiency of CdS nanorod arrays for the degradation of methylene blue due to the effective separation of the electron-hole pairs, and the photocorrosion of CdS nanorod arrays was successfully inhibited
Carbonaceous Adsorbents Prepared from Sewage Sludge and Its Application for Hg0 Adsorption in Simulated Flue Gas
Hydrothermal synthesis, characterization of visible-light-driven α-Bi<sub>2</sub>O<sub>3</sub>enhanced by Pr<sup>3+</sup>doping
TiO2 nanotube/ZnO nanorod/CdS on Ti mesh with three-dimensional array structure for photocatalytic degradation under visible light irradiation
The three-dimensional (3D) TiO2 nanotube arrays (TNTA) were prepared by electrochemical anodization of Ti mesh in a mixed electrolyte solution of (NH4)(2)SO4 and NH4F. Well-defined CdS-sensitized ZnO nanorod arrays (ZNRA/CdS) were successfully built on TNTA by the hydrothermal method and chemical bath deposition. The as-prepared samples were characterized by means of XRD, FESEM, and UV-Vis. The photocatalytic activities of the samples were evaluated by measuring the photodegradation of methylene blue (MB) in aqueous solution under visible light irradiation. The photocatalytic efficiencies for MB degradation were 49 and 60 % for Ti mesh/ZNRA/CdS and Ti mesh/TNTA/ZNRA/CdS after irradiation for 6 h, respectively. This can be attributed to the presence of TNTA at the bottom of a ZNRA/CdS composite, which provides a direct pathway for photoinjected electrons transferring along the photoanode to enhance charge-collection efficiency and consequently reduce electron-hole recombination. Furthermore, it can enlarge the practical applications range of TiO2 due to its 3D nanoarray structure with good light-harvesting ability and flexibility
Fabrication of TiO2 nanotubes-assembled hierarchical microspheres with enhanced photocatalytic degradation activity
TiO2 nanotubes-assembled hierarchical microspheres were fabricated by a one step hydrothermal route using P25 in NaOH aqueous solution with the assistance of H2O2, followed by temperature-programmed calcinations treatment at 400 degrees C. The photocatalytic activity of the sample was investigated by degradation of methyl orange under UV-light irradiation. The results show that TiO2 nanotubes-assembled hierarchical microspheres exhibit much higher photocatalytic degradation activity compared with that of TiO2 nanotubes, which could be attributed to its larger surface area, greater light reflection and the good light multiple scattering property
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