Redox signaling and oxidative stress in systemic acquired resistance.

Plants fully depend on their immune systems to defend against pathogens. Upon pathogen attack, plants not only activate immune responses at the infection site but also trigger a defense mechanism known as systemic acquired resistance (SAR) in distal systemic tissues to prevent subsequent infections by a broad-spectrum of pathogens. SAR is induced by mobile signals produced at the infection site. Accumulating evidence suggests that reactive oxygen species (ROS) play a central role in SAR signaling. ROS burst at the infection site is one of the earliest cellular responses following pathogen infection and can spread to systemic tissues through membrane-associated NADPH oxidase-dependent relay-production of ROS. It is well known that ROS ignite redox signaling and when in excess, cause oxidative stress damaging cellular components. In this review, we summarize current knowledge on redox regulation of several SAR signaling components. We discuss the ROS amplification loop in systemic tissues involving multiple SAR mobile signals. Moreover, we highlight the essential role of oxidative stress in generating SAR signals including azelaic acid and extracellular NAD(P) [eNAD(P)]. Finally, we propose that eNAD(P) is a damage-associated molecular pattern serving as a converging point of SAR mobile signals in systemic tissues.

Trajectories of depressive symptom and its association with air pollution: evidence from the Mr. OS and Ms. OS Hong Kong cohort study.

BACKGROUND: Depression is a global health priority. Maintaining and delaying depressive symptoms in older adults is a key to healthy aging. This study aimed to identify depressive symptom trajectories, predictors and mortality, while also exploring the relationship between air quality and depressive symptoms in older adults in the Hong Kong community over 14 years. METHODS: This study is a longitudinal study in Hong Kong. The target population was community-dwelling older adults over age 65. Depressive symptoms were measured by the Geriatric Depression Scale (GDS-15). Group-based trajectory model was used to identify heterogeneity in longitudinal changes over 14 years and examine the associations between baseline variables and trajectories for different cohort members using multinomial logistic regression. The Kaplan-Meier method was employed to conduct survival analysis and explore the variations in survival probabilities over time among different trajectory group. Linear mixed model was used to explore the relationship between air quality and depressive symptoms. RESULTS: A total of 2828 older adults were included. Three different trajectories of depressive symptoms in older people were identified: relatively stable (15.4%), late increase (67.1%) and increase (17.5%). Female, more number of chronic diseases, poor cognitive function, and poor health-related quality of life (HRQOL) were significantly associated with other less favorable trajectories compared with participants with stable levels of depressive symptoms. The late increase group had a lower mortality rate than the relatively stable and increased groups. Lower baseline ambient air pollutant exposure to NO2 over 14 years was significantly associated with fewer depressive symptoms. CONCLUSIONS: In this study, we found that a late increase in depressive symptoms was the predominant trend in older Chinese people in Hong Kong. Poorer HRQOL was predictive of less favorable trajectories of depressive symptoms. Ambient air pollution was associated with depressive symptoms. This novel observation strengthens the epidemiological evidence of longitudinal changes in depressive symptoms and associations with late-life exposure to air pollution.

Barriers and facilitators to acceptance and implementation of eMental-health intervention among older adults: A qualitative systematic review.

Objective: Electronic mental health interventions are effective but not well promoted currently among older adults. This study sought to systematically review and summarize the barriers and facilitators of accepting and implementing electronic mental health interventions among older adults. Methods: We comprehensively retrieved six electronic databases from January 2012 to September 2022: PubMed, Web of Science, Embase, Scopus, PsycINFO, and CINAHL. The JBI-QARI was used to assess the quality of the research methodology of each publication. Eligible studies underwent data coding and synthesis aligned to inductive and deductive methods. The Consolidated Framework for Implementation Research 2.0 was used as a deductive framework to guide a more structured analysis. Results: The systematic review screened 4309 articles, 17 of which were included (eight with mixed methods and nine with qualitative methods). We identified and extracted the barriers and facilitators of accepting and implementing electronic mental health interventions among older adults: (1) innovation: technology challenges, optimized functions, and contents, security and privacy; (2) outer setting: community engagement and partnerships, financing; (3) inner setting: leadership engagement, available resources, incompatibility, intergenerational support, training and guidance; (4) individuals: perceptions, capability, motivation of older adults and healthcare providers; and (5) implementation process: recruit, external assistance, and team. Conclusion: These findings are critical to optimizing, promoting, and expanding electronic mental health interventions among older adults. The systematic review also provides a reference for better evidence-based implementation strategies in the future.

Unveiling the lithium deintercalation mechanisms in spent lithium-ion batteries via sulfation roasting.

Recovery of valuable metals from spent lithium-ion batteries (LIBs) is of great importance for resource sustainability and environmental protection. This study introduced pyrite ore (FeS2) as an alternative additive to achieve the selective recovery of Li2CO3 from spent LiCoO2 (LCO) batteries. The mechanism study revealed that the sulfation reaction followed two pathways. During the initial stage (550 °C-800 °C), the decomposition and oxidation of FeS2 and the subsequent gas-solid reaction between the resulting SO2 and layered LCO play crucial roles. The sulfation of lithium occurred prior to cobalt, resulting in the disruption of layered structure of LCO and the transformation into tetragonal spinel. In the second stage (over 800 °C), the dominated reactions were the decomposition of orthorhombic cobalt sulfate and its combination with rhombohedral Fe2O3 to form CoFe2O4. The deintercalation of Li from LCO by the substitution of Fe and conversion of Co(III)/Fe(II) into Co3O4/CoFe2O4 were further confirmed by density functional theory (DFT) calculation results. This fundamental understanding of the sulfation reaction facilitated the future development of lithium extraction methods that utilized additives to substantially reduce energy consumption.

Intrinsic capacity trajectories, predictors and associations with care dependence in community-dwelling older adults: A social determinant of health perspective.

AIMS: To identify intrinsic capacity trajectories, predictors of intrinsic capacity trajectories and associations between intrinsic capacity trajectories and care dependence in community-dwelling older adults in China. METHODS: A retrospective longitudinal study was conducted, and the data were obtained from a five-year national longitudinal cohort study of older adults in China between 2011 and 2015. The social determinants of health framework informed the data analysis and interpretation. RESULTS: A total of 3893 older adults met the selection criteria and were included in the study. Three intrinsic capacity trajectories were identified: high trajectory (15.7 %), stable trajectory (52.7 %) and declining trajectory (31.6 %). Social determinants contribute to intrinsic capacity decline in older adults. Decreased cognitive function, psychological status, and locomotion at baseline were associated with care dependence. CONCLUSION: Approximately thirty percent of the older adults in this cohort study experienced a decline in intrinsic capacity within a 5-year period. Social determinants contributed to this decline in older adults.

Design Strategy of the MnOx Catalyst for SCR of NO with NH3: Mechanism of Lead Poisoning and Improvement Method.

The conventional Mn-based catalysts suffer from lead toxicity and require other transition-metal oxides to enhance their resistance in the selective catalytic reduction of NOx with ammonia (NH3-SCR). Herein, we found that the incorporation of inert silica into pure MnOx effectively improved the Pb resistance. The NOx conversion of the MnOx-SiO2-Pb catalyst was nearly 55% higher than that of the MnOx-Pb catalyst, exhibiting enhanced activity at lower temperatures (150-225 °C). To reveal the essential roles at the molecular level, the types and numbers of surface acidity, nitrate species, and catalytic cycle were established through experimental analysis and theoretical calculations of catalysts. The presence of PbCl2 occupied the active Mn sites, resulting in an obvious decline in the Brønsted acid sites (B-NH4+) and the oxidation performance, and the NH3-SCR cycle was energetically less favorable on the MnOx-Pb catalyst. Conversely, SiO2 played a crucial role in preserving the activity of Mn sites on the MnOx-SiO2-Pb catalyst by preferentially bonding with PbCl2, generating more active intermediates. Significantly, this work provided mechanistic insights into the role of SiO2 in regulating the surface acidity, oxidation performance, and stability of active Mn sites, which is helpful for the design of Mn-based catalysts with high Pb resistance for the NH3-SCR reaction.

Unveiling the SO2 Resistance Mechanism of a Nanostructured SiO2(x)@Mn Catalyst for Low-Temperature NH3-SCR of NO.

Low N2 selectivity and SO2 resistance of Mn-based catalysts for removal of NOx at low temperatures by NH3-SCR (selective catalytic reduction) technology are the two main intractable problems. Herein, a novel core-shell-structured SiO2@Mn catalyst with greatly improved N2 selectivity and SO2 resistance was synthesized by using manganese carbonate tailings as raw materials. The specific surface area of the SiO2@Mn catalyst increased from 30.7 to 428.2 m2/g, resulting in a significant enhancement in NH3 adsorption capacity due to the interaction between Mn and Si. Moreover, the N2O formation mechanism, the anti-SO2 poisoning mechanism, and the SCR reaction mechanism were proposed. N2O originated from the reaction of NH3 with O2 and the SCR reaction, as well as from the reaction of NH3 with the chemical oxygen of the catalyst. Regarding improving the SO2 resistance, DFT calculations showed that SO2 was observed to preferentially adsorb onto the surface of SiO2, thus preventing the erosion of active sites. Adding amorphous SiO2 can transform the reaction mechanism from Langmuir-Hinshelwood (L-H) to Eley-Rideal (E-R) by adjusting the formation of nitrate species to produce gaseous NO2. This strategy is expected to assist in designing an effective Mn-based catalyst for low-temperature NH3-SCR of NO.

Acid-free extraction of valuable metal elements from spent lithium-ion batteries using waste copperas.

A large amount of hazardous spent lithium-ion batteries (LIBs) is produced every year. Recovery of valuable metals from spent LIBs is significant to achieve environmental protection and alleviate resource shortages. In this study, a green and facile process for recovery of valuable metals from spent LIBs by waste copperas was proposed. The effects of heat treatment parameters on recovery efficiency of valuable metals and the redox mechanism were studied systematically through phase transformation behavior and valence transition. At low temperature (≤460 °C), copperas reacted with lithium on the outer layer of LIBs preferentially, but the reduction of transition metals was limited. As the temperature rose to 460-700 °C, the extraction efficiency of valuable metals was greatly enhanced due to the generation of SO2, and the gas-solid reaction proceeded much fast than the solid-solid reaction. In the final stage (≥700 °C), the main reactions were the thermal decomposition of soluble sulfates and the combination of decomposed oxides with Fe2O3 to form insoluble spinel. Under the optimum roasting conditions, i.e., at a copperas/LIBs mass ratio of 4.5, and a roasting temperature of 650 °C and roasting time of 120 min, the leaching efficiencies of Li, Ni, Co and Mn were 99.94%, 99.2%, 99.5% and 99.65%, respectively. The results showed that valuable metals can be selectively and efficiently extracted from the complex cathode materials by water leaching. This study used waste copperas as an aid to recover metals and provided an alternative technical route for green recycling of spent LIBs.

A novel strategy for efficient utilization of manganese tailings: High SO2 resistance SCR catalyst preparation and faujasite zeolite synthesis.

Herein, a core-shell structure SiO2@Mn catalyst was successfully synthesized from manganese tailings for NO removal through selective catalytic reduction with ammonia at low temperature. In the presence of 10 % H2O and 100 ppm SO2, the SiO2@Mn catalyst exhibited excellent catalytic activity of 85 % NO conversion at 225 °C. This special core-shell was constructed by inert nano-SiO2 particles, which grew and encapsulated on the surface of manganese oxide, inhibiting the reaction between SO2 with MnOx and thus improving the SO2 resistance. Furthermore, a filter residue was generated in the process of catalysts preparation. Under proper hydrothermal conditions, the residue comprising of Si, Al, and O was used to synthesize high-crystallinity X-type zeolite. This process fully utilized manganese tailings and inspired for Mn-based catalysts design and X-type zeolite preparation, realizing the dual benefits of atmosphere purification and solid waste disposal.

Constructing C-O bridged CeO2/g-C3N4 S-scheme heterojunction for methyl orange photodegradation：Experimental and theoretical calculation.

Owing to its feasibility, efficiency in light-harvesting and effectiveness in the interfacial charge transfer between two n-type semiconductors, constructing heterojunction photocatalysts have been identified as an effective way for enhancing the photocatalytic properties. In this research, a C-O bridged CeO2/g-C3N4 (cCN) Step-scheme (S-scheme) heterojunction photocatalyst was constructed successfully. Under visible light irradiation, the cCN heterojunction exhibited the photocatalytic degradation efficiency of methyl orange, which was about 4.5 and 1.5 times higher than that of pristine CeO2 and CN, respectively. The DFT calculations, XPS and FTIR analyses demonstrated the formation of C-O linkages. And the calculations of work functions revealed the electrons would flow from g-C3N4 to CeO2 due to the difference in Fermi levels, resulting in the production of internal electric fields. Benefiting from the C-O bond and internal electric field, the photo-induced holes in the valence band of g-C3N4 and the photo-induced electrons from conduction band of CeO2 would be recombined when exposed to visible light irradiation, while leaving the electrons with higher redox potential in the conduction band of g-C3N4. This collaboration accelerated the separation and transfer rate of photo-generated electron-hole pairs, which promoted the generation of superoxide radical (•O2-) and improved the photocatalytic activity.

Trajectories of Social Participation and Its Predictors in Older Adults: Based on the CLHLS Cohorts from 2002 to 2018.

Social participation is a key factor in achieving active aging. This study aimed to explore the trajectories and predictors of social participation changes among older adults in China. The data used in this study are from the ongoing national longitudinal study CLHLS. A total of 2492 older adults from the cohort study were included. Group-based trajectory models (GBTM) were used to identify potential heterogeneity in longitudinal changes over time and investigate associations between baseline predictors and trajectories for different cohort members using logistic regression. Four different trajectories of social participation were reported in older adults, namely, stable (8.9%), slow decline (15.7%), lower score with decline (42.2%), and higher score with decline (9.5%). On multivariate analyses, age, years of schooling, pension, mental health, cognitive function, instrumental activities of daily living, and initial social participation scores significantly impact the rate of change in social participation over time. Four trajectories of social participation were identified in the Chinese elderly population. Management of mental health, physical function, and cognitive function appear to be important in maintaining the long-term social participation of older people in the community. Early identification of factors influencing the rapid decline in social participation and timely interventions can maintain or improve social participation levels in older adults.

In situ deposition of 0D CeO2 quantum dots on Fe2O3-containing solid waste NH3-SCR catalyst: Enhancing redox and NH3 adsorption ability.

As NOx has been turning into a crucial environmental problem, NH3-SCR technology with relatively simple device, reliable operation and low secondary pollution, has become a widely used commercial and mature de-nitration technology. However, some weaknesses restricted the further application of commercialized V2O5-WO3/TiO2 NH3-SCR catalysts, while Fe2O3-based catalysts have received much attention due to their high thermal stability, passable N2 selectivity and low cost. In this study, Fe2O3-containing solid waste derived from Zn extraction process of electric arc furnace dust was exploited as the base material for catalyst preparing. Owing to the complementary and synergistic effect of CeO2 and Fe2O3, 0D CeO2 quantum dots (CeQDs) with fully-exposed active sites, large specific surface area, and rapid charge transfer have been introduced and deposited onto Fe2O3-containing solid waste nanorods. The in-situ deposition of CeQDs led to the admirable enhancement in NH3-SCR catalytic activity, N2 selectivity and SO2 tolerance of the extremely low-cost Fe2O3 catalyst. Comprehensive characterizations and DFT calculations describing the adsorption of O2 and NH3 were applied to analyze the catalyst structure and further investigate the detailed relationship between structural properties and activity as well as reaction mechanism. This work provides new insights for the high-value utilization of iron-containing solid waste and a practical reference for boosting the performance of NH3-SCR catalysts by introducing quantum dots.

Longitudinal impact of metabolic syndrome and depressive symptoms on subsequent functional disability among middle-aged and older adults in China.

BACKGROUND: Few studies examining the impact of metabolic syndrome and depressive symptoms on subsequent functional disability are available. OBJECTIVES: To determine the impact of baseline metabolic syndrome and depressive symptoms on subsequent functional disability. METHODS: This study used data from the 2011 baseline and 2013, 2015 and 2018 follow-up waves of the China Health and Retirement Longitudinal Study (CHARLS). Functional status was assessed by activities of daily living (ADLs) and instrumental ADLs (IADLs). Analyses were restricted to middle-aged and older adults (≥50 years) free of functional disability at baseline. Metabolic syndrome, depressive symptoms, and covariates were measured at baseline. New-onset ADL and IADL disability were obtained in follow-up measurements. Competitive risks based on survival analysis were conducted to examine the impact of baseline metabolic syndrome and depressive symptoms on subsequent functional disability after covariates were controlled. RESULTS: Baseline depressive symptoms significantly predicted functional disability over a 7-year follow-up after adjusting for covariates (Hazard ratio [HR] = 1.54, 95% confidence intervals [CI] = 1.40-1.70 for ADL disability; HR=1.36, 95% CI=1.25-1.48 for IADL disability). Metabolic syndrome significantly predicted ADL disability (HR=1.25, 95% CI=1.14-1.38) but not IADL disability (HR=1.02, 95% CI=0.94-1.10). No significant additive interaction between metabolic syndrome and depressive symptoms on functional disability was found. CONCLUSION: The current study found that baseline depressive symptoms were significantly associated with both ADL and IADL disabilities, while metabolic syndrome significantly predicted ADL disability. In addition, some indications showed that the effect in those with both conditions was greater than the sum of the effects separately.

Influence of phosphorus on the NH3-SCR performance of CeO2-TiO2 catalyst for NOx removal from co-incineration flue gas of domestic waste and municipal sludge.

Domestic waste and municipal sludge are two major solid hazardous substances generated from human daily life. Co-incineration technology is regarded as an effective method for the treatment of them. However, the emitted NOx-containing exhaust with high content of phosphorus should purified strictly. CeO2-TiO2 is a promising catalyst for removal of NOx by NH3-SCR technology, but the effect of phosphorous in the exhaust is ambiguous. Therefore, the effect of phosphorus on NH3-SCR performance and physicochemical properties of CeO2-TiO2 catalyst was investigated in our present work. It was found that phosphorus decreased the NH3-SCR activity below 300 °C. Interestingly, it suppressed the formation of NOx and N2O caused by NH3 over-oxidation above 300 °C. The reason might be that phosphorus induced Ti4+ to migrate from CeO2-TiO2 solid solution and form crystalline TiO2, which led to the destruction of Ti-O-Ce structure in the catalyst. So, the transfer of electrons between Ti and Ce ions, the relative contents of Ce3+, and surface adsorbed oxygen, as well as the redox performance were limited, which further inhibited the over-oxidation of NH3. In addition, phosphorus weakened the NH3 adsorption on Lewis acid sites and the adsorption performance of NO + O2, while increased the Brønsted acid sites. Finally, the reaction mechanism over CeO2-TiO2 catalyst did not change after introducing phosphorus, L-H and E-R mechanisms co-existed on the surface of the catalysts.

qMrdd2, a novel quantitative resistance locus for maize rough dwarf disease.

BACKGROUND: Maize rough dwarf disease (MRDD), a widespread disease caused by four pathogenic viruses, severely reduces maize yield and grain quality. Resistance against MRDD is a complex trait that controlled by many quantitative trait loci (QTL) and easily influenced by environmental conditions. So far, many studies have reported numbers of resistant QTL, however, only one QTL have been cloned, so it is especially important to map and clone more genes that confer resistance to MRDD. RESULTS: In the study, a major quantitative trait locus (QTL) qMrdd2, which confers resistance to MRDD, was identified and fine mapped. qMrdd2, located on chromosome 2, was consistently identified in a 15-Mb interval between the simple sequence repeat (SSR) markers D184 and D1600 by using a recombinant inbred line (RIL) population derived from a cross between resistant ("80007") and susceptible ("80044") inbred lines. Using a recombinant-derived progeny test strategy, qMrdd2 was delineated to an interval of 577 kb flanked by markers N31 and N42. We further demonstrated that qMrdd2 is an incompletely dominant resistance locus for MRDD that reduced the disease severity index by 20.4%. CONCLUSIONS: A major resistance QTL (qMrdd2) have been identified and successfully refined into 577 kb region. This locus will be valuable for improving maize variety resistance to MRDD via marker-assisted selection (MAS).

Comparative Studies of Effects of Vapor- and Liquid-Phase As2O3 on Catalytic Behaviors of V2O5-WO3/TiO2 Catalysts for NH3-SCR.

The role of vapor- and liquid-phase As2O3 in deactivating commercial V2O5-WO3/TiO2 catalyst during the NH3-selective catalytic reduction (SCR) process was explored and compared. As2O3 was loaded via vapor deposition (As(vap)) and the wet impregnation (As(imp)) method, respectively. Results demonstrated that the poisoning extent of vapor arsenic was much stronger than in the liquid state. Differences in As distribution on the catalyst surface was one of the main causes. Most vapor As2O3 could be oxidized to As2O5, which underwent stacking and formed a dense covering layer on the catalyst surface. In comparison, liquid As2O3 could also be oxidized but distributed uniformly and did not change the catalyst pore structure. Loading arsenic would destroy the V-OH and V=O active sites of the catalyst, and less reactive As5+-OH was generated. Catalyst oxidizability was also enhanced, resulting in NH3 oxidation enhancement, decreased N2 selectivity, and a decline in SCR activity. Importantly, the intermediate of NH3 oxidation, NH2-amide, also could react with NO + O2, and more N2O was generated on the poisoned catalyst during the SCR process, especially on As(imp). Finally, two mechanisms of arsenic poisoning were proposed, in which the role of vapor and liquid As2O3 over the V2O5-WO3/TiO2 catalyst was compared.

Separating Sulfur from Fuel Gas Desulfurization Gypsum with an Oxalic Acid Solution.

The separation of sulfur from the wet limestone fuel gas desulfurization (FGD) gypsum using oxalic acid solution was studied. Optimal separation conditions and a separation mechanism of sulfur were investigated. The obtained results indicate that the sulfur in FGD gypsum can be separated efficiently by oxalic acid solution. When separating under the optimal experimental conditions of 0.3 mol/L oxalic acid solution, 30 °C, and a 5/150 g/mL solid to liquid ratio for 8 min, the separation rate reached 97.0 wt %. Besides, the Avrami equation is more suitable for the kinetic analysis of the sulfur separation reaction than the unreacted shrinking core model. When the reaction temperature is less than or equal to 20 °C, the mechanism of the sulfur separation process is chemical-reaction-controlled; otherwise, it is diffusion-controlled. The activation energy E a of the sulfur separation reaction is 34.84 kJ/mol. During the separation process, the pH of the solution gradually decreased due to the conversion of oxalic acid to sulfuric acid, so the liquid obtained after the sulfur separation of FGD gypsum can be recycled as industrial sulfuric acid. Nearly 1 mol of sulfuric acid can be obtained for every mole of oxalic acid consumption.

Genetic dissection of grain water content and dehydration rate related to mechanical harvest in maize.

BACKGROUND: The low grain water content (GWC) at harvest is a prerequisite to mechanical harvesting in maize, or otherwise would cause massive broken kernels and increase drying costs. The GWC at harvest in turn depends on GWC at the physiological maturity (PM) stage and grain dehydration rate (GDR). Both GWC and GDR are very complex traits, governed by multiple quantitative trait loci (QTL) and easily influenced by environmental conditions. So far, a number of experiments have been conducted to reveal numbers of GWC and GDR QTL, however, very few QTL have been confirmed, and no QTL has been fine-mapped or even been cloned. RESULTS: We demonstrated that GWCs after PM were positively correlated with GWC at PM, whereas negatively with GDRs after PM. With a recombinant inbred line (RIL) population, we identified totally 31 QTL related to GWC and 17 QTL related to GDR in three field trials. Seven GWC QTL were consistently detected in at least two of the three field trials, each of which could explain 6.92-24.78% of the total GWC variation. Similarly, one GDR QTL was consistently detected, accounting for 9.44-14.46% of the total GDR variation. Three major GWC QTL were found to overlap with three GDR QTL in bins 1.05/06, 2.06/07, and 3.05, respectively. One of the consistent GWC QTL, namely qGwc1.1, was fine-mapped from a 27.22 Mb to a 2.05 Mb region by using recombinant-derived progeny test. The qGwc1.1 acted in a semi-dominant manner to reduce GWC by 1.49-3.31%. CONCLUSIONS: A number of consistent GWC and GDR QTL have been identified, and one of them, QTL-qGwc1.1, was successfully refined into a 2.05 Mb region. Hence, it is realistic to clone the genes underlying the GWC and GDR QTL and to make use of them in breeding of maize varieties with low GWC at harvest.