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Chronic obstructive pulmonary disease (COPD) is a common chronic disease of the respiratory system that has high morbidity and mortality across the world. Like other chronic diseases, the development of COPD is a long process, and its prognosis could be improved significantly by early prevention and intervention. As the understanding of COPD in the international academic community gradually deepens, the 2022 Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) report first proposed the concept of pre-COPD. We reviewed the development of pre-COPD, analyzed its definition and diagnostic criteria, and summarized the significance of early identification of pre-COPD patients. Pre-COPD results from the widening and deepening of the existing concept of COPD prevention and treatment. A full understanding of pre-COPD will contribute to guiding the direction of COPD pathogenesis research and basic COPD research, and to improving the awareness of primary prevention of COPD in clinical practice, thereby reducing the prevalence and mortality of COPD and the burden of COPD on families and society.

Thermocatalytic decomposition is an efficient purification technology that is potentially applicable to degrading chemical warfare agents and industrial toxic gases. In particular, ZrO2 has attracted attention as a catalyst for the thermocatalytic decomposition of dimethyl methylphosphonate (DMMP), which is a simulant of the nerve gas sarin. However, the influence of the crystal phase and morphology on the catalytic performance of ZrO2 requires further exploration. In this study, monoclinic- and tetragonal-phase ZrO2 (m- and t-ZrO2, respectively) with nanoparticle, flower-like shape and hollow microsphere morphologies were prepared via hydrothermal and solvothermal methods, and their thermocatalytic decomposition of DMMP was systematically investigated. For a given morphology, m-ZrO2 performed better than t-ZrO2. For a given crystalline phase, the morphology of hollow microspheres resulted in the longest protection time. The exhaust gases generated by the thermocatalytic decomposition of DMMP mainly comprised H2, CO2, H2O and CH3OH, and the by-products were phosphorus oxide species. Thus, the deactivation of ZrO2 was attributed to the deposition of these phosphorous oxide species on the catalyst surface. These results are expected to help guide the development of catalysts for the safe disposal of chemical warfare agents. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) is a colourless, odourless, and toxic gas. Long-term exposure to high concentrations of CO causes poisoning and even death; therefore, CO removal is particularly important. Current research has focused on the efficient and rapid removal of CO via low-temperature (ambient) catalytic oxidation. Gold nanoparticles are widely used catalysts for the high-efficiency removal of high concentrations of CO at ambient temperature. However, easy poisoning and inactivation due to the presence of SO2 and H2S affect its activity and practical application. In this study, a bimetallic catalyst, Pd-Au/FeOx/Al2O3, with a Au:Pd ratio of 2:1 (wt%) was formed by adding Pd nanoparticles to a highly active Au/FeOx/Al2O3 catalyst. Its analysis and characterisation proved that it has improved catalytic activity for CO oxidation and excellent stability. A total conversion of 2500 ppm of CO at −30 °C was achieved. Furthermore, at ambient temperature and a volume space velocity of 13,000 h−1, 20,000 ppm CO was fully converted and maintained for 132 min. Density functional theory (DFT) calculations and in situ FTIR analysis revealed that Pd-Au/FeOx/Al2O3 exhibited stronger resistance to SO2 and H2S adsorption than the Au/FeOx/Al2O3 catalyst. This study provides a reference for the practical application of a CO catalyst with high performance and high environmental stability. [ABSTRACT FROM AUTHOR]

The catalytic performances of the catalysts and decomposition mechanisms of dimethyl methylphosphonate (DMMP), a commonly used nerve agent simulant, are well understood based on previous studies. However, the effects of the morphology of the catalyst on DMMP decomposition performance and mechanisms remain unexplored. Thus, in this work, experimental studies were conducted on the thermocatalytic decomposition of DMMP on CeO2 nanomaterials with different morphologies, e.g., irregular nanoparticles, nanorods, and nanocubes. From the performance evaluation, CeO2 nanorods exhibited higher DMMP thermocatalytic decomposition performance as compared to irregular nanoparticles and nanocubes. The primary reaction pathways were the same on all three morphologies of materials, according to in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study, whereas side reaction paths showed variable behaviors. According to the catalytic reaction mechanism study, the surface lattice oxygen played a vital role in the thermocatalytic decomposition of DMMP and the accumulation of phosphates, carbonates, and formates were the main factors for deactivation of the catalyst. The behavior of CeO2 catalyst with different morphologies in the thermocatalytic decomposition of DMMP was revealed in this work, and this will be useful for the future design of high-performing catalysts for the efficient degradation of chemical toxicant. [ABSTRACT FROM AUTHOR]

A novel BiOI/TiO2 nano-heterojunction was prepared using hydrothermal and sol-gel methods. The composite material was characterized by X-ray diffraction, ultraviolet-visible diffuse reflection spectroscopy, scanning electron microscopy, and transmission electron microscopy. The crystallinity and response to light of BiOI/TiO2 were controlled by preparation conditions such as the optimal solvent condition and heat treatment temperature. The photocatalytic activity of the BiOI/TiO2 catalyst was examined using benzene as a test molecule. The benzene degradation rate of the composite catalyst under visible light was enhanced compared to pure TiO2, thus reaching 40% of the original benzene concentration, which increased further to >60% after surface acidification. The fluorescence spectra, light current, and electron paramagnetic resonance confirmed that the enhanced activity was attributed to carrier separation by the heterojunction. The acid sites and active chlorine of hydrochloric acidification offer a novel mechanism for photocatalytic reactions. [ABSTRACT FROM AUTHOR]

Bimetallic synergism plays an important role in lattice-doped catalysts. Therefore, lattice-doped bimetallic CuO/CeO2 catalysts were prepared by secondary alkaline hydrothermal reaction. During this process, the CeO2 nanomaterials were partially dissolved and recrystallized; thus, Cu ions were doped into the CeO2 lattice. The physical and chemical properties of CeO2, CuO/CeO2, and CuO were investigated. H2 temperature-programmed reduction characterization showed that the oxidation activity of CuO/CeO2 was significantly improved. X-ray photoelectron spectroscopy results showed that electron transfer occurred between Ce and Cu in the CuO/CeO2 catalyst. Additionally, Raman characterization confirmed the strong interaction between Cu and Ce. After CuO was loaded, the thermal catalytic decomposition performance of the catalyst was significantly improved with respect to the sarin simulant dimethyl methyl phosphonate (DMMP); with an increase in the Cu/Ce ratio, the performance first strengthened and then weakened. Additionally, the reaction tail gas and catalyst surface products were analyzed using mass spectrometry and ion chromatography, and the changes in the surface products during the thermal catalytic decomposition of DMMP were characterized at different temperatures using in situ diffuse reflectance infrared Fourier transform spectroscopy. Finally, the catalytic reaction pathways of DMMP on CeO2, CuO/CeO2, and CuO were inferred. The study results not only demonstrate an effective catalyst for the removal of nerve agent but also a feasible preparation method for lattice-doped bimetallic catalysts in the field of environmental protection. [ABSTRACT FROM AUTHOR]

Chemical warfare agents (CWAs) are highly toxic and fast-acting and are easy to cause large-scale poisoning to humans and livestock after being released. The activated carbon used for CWAs adsorption has disadvantages of limited adsorption capacity, easy aging and deactivation. Metal oxides have environmental stability, and they are characterized by long lasting and broad spectrum when used for thermal catalytic decomposition. Therefore, in this study, the supported copper–cerium catalyst CuO-CeO2/γ-Al2O3 was prepared using an equal volume impregnation method. The thermal catalytic decomposition performance was studied using sarin CWAs simulant dimethyl methyl phosphonate (DMMP) as the target compound. The results show that the CuO-CeO2/γ-Al2O3 catalyst with a CeO2 loading of 5% exhibited better thermal catalytic decomposition performance of DMMP. The catalyst provided protection against DMMP for 237 min at 350 °C; CuO was highly dispersed on CuO-5% CeO2/γ-Al2O3, and there was a strong interaction between Cu and Ce on CuO-5% CeO2/γ-Al2O3, which promoted the generation of surface-adsorbed oxygen, leading to a better thermal catalytic decomposition performance of DMMP. This study is expected to provide a reference for the study of catalysts for the thermal catalytic decomposition of CWAs. [ABSTRACT FROM AUTHOR]