Can early gut microbiota screening reduce the incidence of cognitive impairment? A Mendelian randomization study.

Background: Gastrointestinal symptoms are now detected early in the clinical course of many dementia patients, and studies of the microbiome-gut-brain axis have confirmed bidirectional interactions between the gut and the brain. However, the causal relationship between gut microbiota and cognitive impairment has not been fully established. Therefore, this study conducted a bidirectional Mendelian randomization study to elucidate the potential causal relationship of gut microbiota to cognitive impairment. Objective: Using Mendelian randomization to identify gut flora with a genetic causal effect on the development of cognitive impairment. Methods: This study utilized publicly available genome-wide association study summary data to perform MR analysis, with gut microbiota as the exposure and various cognitive function indicators as well as scores for Alzheimer's disease as outcomes. This study selected single nucleotide polymorphisms as instrumental variables based on p-values, F-statistics, and r2. Bidirectional Mendelian randomization was conducted using methods such as inverse variance weighted, MR-Egger, simple mode, and weighted mode to assess the causal relationship. Concurrently, this study carried out Cochran's Q test, MR-Egger intercept test, and leave-one-out analysis to identify potential heterogeneity and horizontal pleiotropy. Results: This study identified a total of 31 gut microbes that have a causal relationship with cognitive impairment, which include 1 phylum, 4 classes, 3 orders, 2 families, and 21 genera. Conclusions: This study unveiled specific gut microbiota associated with cognitive impairment, offering new insights and approaches for the prevention and treatment of cognitive impairment through gut microbiota such as Bifidobacterium and Ruminococcus gnavus group.

RGS22 maintains the physiological function of ependymal cells to prevent hydrocephalus.

Ependymal cells line the wall of cerebral ventricles and ensure the unidirectional cerebrospinal fluid (CSF) flow by beating their motile cilia coordinately. The ependymal denudation or ciliary dysfunction causes hydrocephalus. Here, we report that the deficiency of regulator of G-protein signaling 22 (RGS22) results in severe congenital hydrocephalus in both mice and rats. Interestingly, RGS22 is specifically expressed in ependymal cells within the brain. Using conditional knock-out mice, we further demonstrate that the deletion of Rgs22 exclusively in nervous system is sufficient to induce hydrocephalus. Mechanistically, we show that Rgs22 deficiency leads to the ependymal denudation and impaired ciliogenesis. This phenomenon can be attributed to the excessive activation of lysophosphatidic acid receptor (LPAR) signaling under Rgs22-/- condition, as the LPAR blockade effectively alleviates hydrocephalus in Rgs22-/- rats. Therefore, our findings unveil a previously unrecognized role of RGS22 in the central nervous system, and present RGS22 as a potential diagnostic and therapeutic target for hydrocephalus.

Hierarchically structured nanofibrous scaffolds spatiotemporally mediate the osteoimmune micro-environment and promote osteogenesis for periodontitis-related alveolar bone regeneration.

Periodontitis suffer from inflammation-induced destruction of periodontal tissues, resulting in the serious loss of alveolar bone. Controlling inflammation and promoting bone regeneration are two crucial aspects for periodontitis-related alveolar bone defect treatment. Herein, we developed a hierarchically structured nanofibrous scaffold with a nano-embossed sheath and a bone morphogenetic protein 2-loaded core to match the periodontitis-specific features that spatiotemporally modulated the osteoimmune environment and promoted periodontal bone regeneration. We investigated the potential of this unique scaffold to treat periodontitis-related alveolar bone defects in vivo and in vitro. The results demonstrated that the hierarchically structured scaffold effectively reduced the inflammatory levels in macrophages and enhanced the osteogenic potential of bone mesenchymal stem cells in an inflammatory microenvironment. Moreover, in vivo experiments revealed that the hierarchically structured scaffold significantly ameliorated inflammation in the periodontium and inhibited alveolar bone resorption. Notably, the hierarchically structured scaffold also exhibited a prolonged effect on promoting alveolar bone regeneration. These findings highlight the significant therapeutic potential of hierarchically structured nanofibrous scaffolds for the treatment of periodontitis, and their promising role in the field of periodontal tissue regeneration. STATEMENT OF SIGNIFICANCE: We present a novel hierarchically structured nanofibrous scaffold of coupling topological and biomolecular signals for precise spatiotemporal modulation of the osteoimmune micro-environment. Specifically, the scaffold was engineered via coaxial electrospinning of the poly(ε-caprolactone) sheath and a BMP-2/polyvinyl alcohol core, followed by surface-directed epitaxial crystallization to generate cyclic nano-lamellar embossment on the sheath. With this unique hierarchical structure, the cyclic nano-lamellar sheath provided a direct nano-topographical cue to alleviate the osteoimmune environment, and the stepwise release of BMP-2 from the core provided a biological cue for bone regeneration. This research underscores the potential of hierarchically structured nanofibrous scaffolds as a promising therapeutic approach for periodontal tissue regeneration and highlights their role in advancing periodontal tissue engineering.

Global prevalence of liver disease in human and domestic animals caused by Fasciola: A systematic review and meta-analysis.

Background: Liver disease caused by Fasciola is a significant zoonotic and parasitic disease with substantial economic impacts on humans and animals. Many studies have looked at the prevalence of fasciolis worldwide, yet the overall prevalence and risk factors in cattle, ruminants, and humans remains unknown. Methods: We conducted a systematic review and meta-analysis to estimate the global prevalence and risk factors of fascioliasis in humans and domestic ruminants. With this aim, we searched PubMed, ScienceDirect, Web of Science, and Scopus from inception to 8 December 2022 for studies reporting the prevalence of fascioliasis in humans or domestic ruminants post-2000. We then used random effects models to describe the prevalence of fascioliasis; trim-and-fill analysis and Egger's test to assess publication bias; and meta-regression and sensitivity analyses to examine the risk factors for prevalence and heterogeneity. Results: We retrieved 4422 articles, with 371 being included in the analysis, as they concerned fascioliasis in humans and ruminants globally. The pooled prevalence of bovine fasciolosis was 17%, while ovine fasciolosis and human fascioliasis had pooled prevalences of 13% and 5%, respectively. We also conducted subgroup analyses by continents, countries, Fasciola species, sampling years, altitude, rainfall, temperature, humidity, age, sex, feeding mode, and residence. Here, altitude and age emerged as risk factors associated with an increased prevalence of fascioliasis. Both the trim-and-fill analysis and Egger's test confirmed the presence of publication bias, while the sensitivity analysis showed that the omission of any single study did not significantly influence the combined pooled prevalence. Conclusions: Fascioliasis is a widely prevalent zoonosis among humans and livestock worldwide. Strategies targeting risk factors such as altitude and age are urgently needed for prevention and control of this disease, which will consequently reduce Fasciola infection. Additionally, given the inadequacy or absence of data in some countries, greater attention should be paid to Fasciola infection, with further epidemiological studies focussing on improving data quality.

An estimation of future county-level cement production and associated air pollutant emissions in China through artificial neural networks.

Cement production and its air pollutant and carbon dioxides (CO2) emissions in China will be relocated greatly as a joint effect of diverse development of industrial economy and implementation of environmental policies for different regions. The future pathway and spatial pattern of emissions are important for policy making of air quality improvement and CO2 emission abatement, as well as coordinating regional development. In this study, we developed an artificial neural network (ANN) model to predict cement production at the county level and to calculate the associated emissions of air pollutants and CO2 at the county level till 2060. Results show that the cement production will decline from 2327 million metric tons (Mt) in 2015 to 704 Mt. in 2060 under the Shared Socioeconomic Pathways 1 (SSP1). Counties closer to provincial capital will experience greater retirement of cement industry. Likewise, the emissions of air pollutants and CO2 will experience a steady downward trend driven by the declining cement production and the improvement of pollution control technologies. There will be a more significant regional heterogeneity in the reduction of production and emissions at city level compared to the province level. With the clearance for nearly two-thirds of counties, future cement production and emissions will be more intensively distributed in a few cities. The shares of emissions in southwestern regions will grow from 2015 to 2060 while those of eastern regions will continue decreasing. The comparison between the changing spatial distributions of emissions and gross domestic product (GDP) indicates a positive effect of existing policies in reconciling regional economic development and air pollution controls. The outcome could support the analyses on the impact of industrial development on air quality and public health, and the method can be applied widely for other industrial sectors for a more comprehensive understanding of future emission relocation.

Air Quality, Health, and Equity Benefits of Carbon Neutrality and Clean Air Pathways in China.

In the pursuit of carbon neutrality, China's 2060 targets have been largely anchored in reducing greenhouse gas emissions, with less emphasis on the consequential benefits for air quality and public health. This study pivots to this critical nexus, exploring how China's carbon neutrality aligns with the World Health Organization's air quality guidelines (WHO AQG) regarding fine particulate matter (PM2.5) exposure. Coupling a technology-rich integrated assessment model, an emission-concentration response surface model, and exposure and health assessment, we find that decarbonization reduces sulfur dioxide (SO2), nitrogen oxides (NOx), and PM2.5 emissions by more than 90%; reduces nonmethane volatile organic compounds (NMVOCs) by more than 50%; and simultaneously reduces the disparities across regions. Critically, our analysis reveals that further targeted reductions in air pollutants, notably NH3 and non-energy-related NMVOCs, could bring most Chinese cities into attainment of WHO AQG for PM2.5 5 to 10 years earlier than the pathway focused solely on carbon neutrality. Thus, the integration of air pollution control measures into carbon neutrality strategies will present a significant opportunity for China to attain health and environmental equality.

Unveiling the health impacts of air pollution transport in China.

The transport of atmospheric pollutants plays a pivotal role in regional air pollution, highlighting critical concerns over the unequal health outcomes that arise from such transport. While previous researches predominantly focused on key areas in the battle against air pollution, the intensification of control measures necessitates a national perspective to comprehend the health impacts due to pollution transport. Our study establishes an integrated assessment framework that combine an emission-concentration response surface model with a health impact evaluation model to analyse the nationwide health impacts of PM2.5 and O3 pollution transport across China's 31 provinces. We found that, interprovincial transport of PM2.5 and O3 contributed to 747,000 and 110,000 deaths respectively in 2017, which amounts to 38% and 48% of deaths caused by total anthropogenic emissions. North, East, and Central China together contribute 82% and 69% to the health impacts caused by regional PM2.5 and O3 transport respectively, and the transport among these three regions is also significant. The analysis of interprovincial health impact transport shows that, for PM2.5, the top contributors are Hebei, Shandong, Henan, Anhui, and Jiangsu, with the most affected being Henan, Shandong, Jiangsu, Hebei, and Guangdong. Regarding O3, Shandong, Hebei, Henan, Jiangsu, and Anhui contribute the most, while Henan, Shandong, Hebei, Jiangsu, and Anhui are the most affected. This study can shed lights on regional control strategies by prioritizing control areas based on the health impact of air pollution transport in China.

Clinical study of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in hypertriglyceridemia-induced acute pancreatitis and acute biliary pancreatitis with persistent organ failure.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are novel inflammatory indicators that can be used to predict the severity and prognosis of various diseases. We categorize acute pancreatitis by etiology into acute biliary pancreatitis (ABP) and hypertriglyceridemia-induced acute pancreatitis (HTGP). AIM: To investigate the clinical significance of NLR and PLR in assessing persistent organ failure (POF) in HTGP and ABP. METHODS: A total of 1450 patients diagnosed with acute pancreatitis (AP) for the first time at Shanxi Bethune Hospital between January 2012 and January 2023 were enrolled. The patients were categorized into two groups according to the etiology of AP: ABP in 530 patients and HTGP in 241 patients. We collected and compared the clinical data of the patients, including NLR, PLR, and AP prognostic scoring systems, within 48 h of hospital admission. RESULTS: The NLR (9.1 vs 6.9, P < 0.001) and PLR (203.1 vs 160.5, P < 0.001) were significantly higher in the ABP group than in the HTGP group. In the HTGP group, both NLR and PLR were significantly increased in patients with severe AP and those with a SOFA score ≥ 3. Likewise, in the ABP group, NLR and PLR were significantly elevated in patients with severe AP, modified computed tomography severity index score ≥ 4, Japanese Severity Score ≥ 3, and modified Marshall score ≥ 2. Moreover, NLR and PLR showed predictive value for the development of POF in both the ABP and HTGP groups. CONCLUSION: NLR and PLR vary between ABP and HTGP, are strongly associated with AP prognostic scoring systems, and have predictive potential for the occurrence of POF in both ABP and HTGP.

Health-Oriented Emission Control Strategy of Energy Utilization and Its Co-CO2 Benefits: A Case Study of the Yangtze River Delta, China.

Reducing air pollutants and CO2 emissions from energy utilization is crucial for achieving the dual objectives of clean air and carbon neutrality in China. Thus, an optimized health-oriented strategy is urgently needed. Herein, by coupling a CO2 and air pollutants emission inventory with response surface models for PM2.5-associated mortality, we shed light on the effectiveness of protecting human health and co-CO2 benefit from reducing fuel-related emissions and generate a health-oriented strategy for the Yangtze River Delta (YRD). Results reveal that oil consumption is the primary contributor to fuel-related PM2.5 pollution and premature deaths in the YRD. Significantly, curtailing fuel consumption in transportation is the most effective measure to alleviate the fuel-related PM2.5 health impact, which also has the greatest cobenefits for CO2 emission reduction on a regional scale. Reducing fuel consumption will achieve substantial health improvements especially in eastern YRD, with nonroad vehicle emission reductions being particularly impactful for health protection, while on-road vehicles present the greatest potential for CO2 reductions. Scenario analysis confirms the importance of mitigating oil consumption in the transportation sector in addressing PM2.5 pollution and climate change.

Comparison of inebilizumab or rituximab in addition to glucocorticoid therapy for neuromyelitis optica spectrum disorders.

AIM: To investigate the short-term efficacy and safety of inebilizumab for neuromyelitis optica spectrum disorders (NMOSD). METHODS: A total of 33 patients with NMOSD treated with inebilizumab (Group INB, n=15) or rituximab (Group RTX, n=18) in addition to high-dose glucocorticoids were included. Both groups underwent hormone shock therapy during the acute phase. Subsequently, Group INB received inebilizumab injections during the remission phase, while Group RTX received rituximab injections. A comparison of aquaporins 4 (AQP4) titer values, peripheral blood B lymphocyte counts, and visual function recovery was conducted before and 8wk after treatment. Additionally, adverse reactions and patient tolerability were analyzed after using inebilizumab treatment regimes. RESULTS: Following inebilizumab treatment, there was a significantly improvement in the visual acuity of NMOSD patients (P<0.05), accompanied by a notable decrease in AQP4 titer values and B lymphocyte ratio (P<0.05). Moreover, inebilizumab treatment showed a partial effect in preventing optic nerve atrophy (P<0.05). However, there were no significant differences in other therapeutic effects compared to rituximab, which has previously demonstrated substantial therapeutic efficacy (P>0.05). Furthermore, inebilizumab exhibited higher safety levels than that of rituximab injections. CONCLUSION: The combination of inebilizumab and high-dose glucocorticoids proves to be effective. In comparison to rituximab injections, inebilizumab displays better tolerance and safety. Moreover, it demonstrates a partial effect in preventing optic nerve atrophy. Thus, it stands as an effective method to reduce the disability rates and improve the daily living ability of patients with NMOSD.

Methylobacterium nigriterrae sp. nov., isolated from black soil.

An aerobic, Gram-stain-negative, motile rod bacterium, designated as SYSU BS000021T, was isolated from a black soil sample in Harbin, Heilongjiang province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Methylobacterium, and showed the highest sequence similarity to Methylobacterium segetis KCTC 62267 T (98.51%) and Methylobacterium oxalidis DSM 24028 T (97.79%). Growth occurred at 20-37℃ (optimum, 28 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0% (w/v) NaCl. Polar lipids comprised of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid and one unidentified polar lipid. The major cellular fatty acids (> 5%) were C18:0 and C18:1 ω7c and/or C18:1 ω6c. The predominant respiratory quinone was Q-10. The genomic G + C content was 68.36% based on the whole genome analysis. The average nucleotide identity (≤ 83.5%) and digital DNA-DNA hybridization (≤ 27.3%) values between strain SYSU BS000021T and other members of the genus Methylobacterium were all lower than the threshold values recommended for distinguishing novel prokaryotic species. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain SYSU BS000021T represents a novel species of the genus Methylobacterium, for which the name Methylobacterium nigriterrae sp. nov. is proposed. The type strain of the proposed novel species is SYSU BS000021T (= GDMCC 1.3814 T = KCTC 8051 T).

The safety and short-term effect of mixed approach in laparoscopic right hemicolectomy for right colon cancer compared with middle approach: a retrospective study.

PURPOSE: To investigate whether the mixed approach is a safe and advantageous way to operate laparoscopic right hemicolectomy. METHODS: A retrospective study was performed on 316 patients who underwent laparoscopic right hemicolectomy in our center. They were assigned to the middle approach group (n = 158) and the mixed approach group (n = 158) according to the surgical approaches. The baseline data like gender、age and body mass index as well as the intraoperative and postoperative conditions including operation time, blood loss, postoperative hospital stay and complications were analyzed. RESULTS: There were no significant differences in age, sex, BMI, ASA grade and tumor characteristics between the two groups. Compared with the middle approach group, the mixed approach group was significantly lower in terms of operation time (217.61 min vs 154.31 min, p < 0.001), intraoperative blood loss (73.8 ml vs 37.97 ml, p < 0.001) and postoperative drainage volume. There was no significant difference in the postoperative complications like postoperative anastomotic leakage, postoperative infection and postoperative intestinal obstruction. CONCLUSIONS: Compared with the middle approach, the mixed approach is a safe and advantageous way that can significantly shorten the operation time, reduce intraoperative bleeding and postoperative drainage volume, and does not prolong the length of hospital stay or increase the morbidity postoperative complications.

Electrospun medicated gelatin/polycaprolactone Janus fibers for photothermal-chem combined therapy of liver cancer.

Liver cancer is a common cancer in the world, and core-shell nanoparticles as a commonly used combination therapy for local tumor ablation, have many shortcomings. In this study, photothermal Janus nanofibers were prepared using a electrospinning technology for tumor treatment, and the products were characterized and in vitro photothermal performance investigated. The micromorphology analysis showed that the photothermic agent CuS and electrospun fibers (loaded with CuS and anticancer drug dihydromyricetin) were successfully prepared, with diameters of 11.58 ± 0.27 µm and 1.19 ± 0.01 µm, respectively. Water contact angle and tensile test indicated that the fiber membranes has a certain hydrophilic adhesion and excellent mechanical strength. The fiber membranes has 808 nm near-infrared laser photothermal heating performance and photothermal stability, and it also has a strong response to the laser that penetrates biological tissue. In addition, in vitro cell culture and in vivo implantation study showed that the fiber membranes could kill HepG2 hepatocellular carcinoma cells combined with photothermal-chem and could be enriched in the implantation area, respectively. Hence, the Janus membranes may be a potential cancer treatment material.

Spatially and Temporally Differentiated NOx and VOCs Emission Abatement Could Effectively Gain O3-Related Health Benefits.

The increasing level of O3 pollution in China significantly exacerbates the long-term O3 health damage, and an optimized health-oriented strategy for NOx and VOCs emission abatement is needed. Here, we developed an integrated evaluation and optimization system for the O3 control strategy by merging a response surface model for the O3-related mortality and an optimization module. Applying this system to the Yangtze River Delta (YRD), we evaluated driving factors for mortality changes from 2013 to 2017, quantified spatial and temporal O3-related mortality responses to precursor emission abatement, and optimized a health-oriented control strategy. Results indicate that insufficient NOx emission abatement combined with deficient VOCs control from 2013 to 2017 aggravated O3-related mortality, particularly during spring and autumn. Northern YRD should promote VOCs control due to higher VOC-limited characteristics, whereas fastening NOx emission abatement is more favorable in southern YRD. Moreover, promotion of NOx mitigation in late spring and summer and facilitating VOCs control in spring and autumn could further reduce O3-related mortality by nearly 10% compared to the control strategy without seasonal differences. These findings highlight that a spatially and temporally differentiated NOx and VOCs emission control strategy could gain more O3-related health benefits, offering valuable insights to regions with severe ozone pollution all over the world.

Association of histone modification with the development of schizophrenia.

Schizophrenia, influenced by genetic and environmental factors, may involve epigenetic alterations, notably histone modifications, in its pathogenesis. This review summarizes various histone modifications including acetylation, methylation, phosphorylation, ubiquitination, serotonylation, lactylation, palmitoylation, and dopaminylation, and their implications in schizophrenia. Current research predominantly focuses on histone acetylation and methylation, though other modifications also play significant roles. These modifications are crucial in regulating transcription through chromatin remodeling, which is vital for understanding schizophrenia's development. For instance, histone acetylation enhances transcriptional efficiency by loosening chromatin, while increased histone methyltransferase activity on H3K9 and altered histone phosphorylation, which reduces DNA affinity and destabilizes chromatin structure, are significant markers of schizophrenia.

Upf2-Mediated Nonsense-Mediated Degradation Pathway Involved in Genetic Compensation of TrpA1 Knockout Mutant Silkworm (Bombyx mori).

Genetic mutations leading to premature termination codons are known to have detrimental effects. Using the Lepidoptera model insect, the silkworm (Bombyx mori), we explored the genetic compensatory response triggered by mutations with premature termination codons. Additionally, we delved into the molecular mechanisms associated with the nonsense-mediated mRNA degradation pathway. CRISPR/Cas9 technology was utilized to generate a homozygous bivoltine silkworm line BmTrpA1-/- with a premature termination. Transcript levels were assessed for the BmTrpA paralogs, BmPyrexia and BmPainless as well as for the essential factors Upf1, Upf2, and Upf3a involved in the nonsense-mediated mRNA degradation (NMD) pathway. Upf2 was specifically knocked down via RNA interference at the embryonic stage. The results comfirmed that the BmTrpA1 transcripts with a 2-base deletion generating a premature termination codon in the BmTrpA1-/- line. From day 6 of embryonic development, the mRNA levels of BmPyrexia, BmPainless, Upf1, and Upf2 were significantly elevated in the gene-edited line. Embryonic knockdown of Upf2 resulted in the suppression of the genetic compensation response in the mutant. As a result, the offspring silkworm eggs were able to hatch normally after 10 days of incubation, displaying a non-diapause phenotype. It was observed that a genetic compensation response does exist in BmTrpA1-/-B. mori. This study presents a novel discovery of the NMD-mediated genetic compensation response in B. mori. The findings offer new insights into understanding the genetic compensation response and exploring the gene functions in lepidopteran insects, such as silkworms.

Integrated analyses for identification of a three-gene signature associated with Chaihu Shugan San formula for hepatocellular carcinoma treatment.

Chaihu Shugan San (CSS) is a well-known traditional herbal formula that has the potential to ameliorate hepatocellular carcinoma (HCC); however, its mechanism of action remains unknown. Here, we identified the key targets of CSS against HCC and developed a prognostic model to predict the survival of patients with HCC. The effect of CSS plus sorafenib on HCC cell proliferation was evaluated using the MTT assay. LASSO-Cox regression was used to establish a three-gene signature model targeting CSS. Correlations between immune cells, immune checkpoints and risk score were determined to evaluate the immune-related effects of CSS. The interactions between the components and targets were validated using molecular docking and Surface Plasmon Resonance (SPR) assays. CSS and sorafenib synergistically inhibited HCC cell proliferation. Ten core compounds and 224 targets were identified using a drug compound-target network. The prognostic model of the three CSS targets (AKT1, MAPK3 and CASP3) showed predictive ability. Risk scores positively correlated with cancer-promoting immune cells and high expression of immune checkpoint proteins. Molecular docking and SPR analyses confirmed the strong binding affinities of the active components and the target genes. Western blot analysis confirmed the synergistic effect of CSS and sorafenib in inhibiting the expression of these three targets. In conclusion, CSS may regulate the activity of immune-related factors in the tumour microenvironment, reverse immune escape, enhance immune responses through AKT1, MAPK3, and CASP3, and synergistically alleviate HCC. The co-administration of sorafenib with CSS has a strong clinical outlook against HCC.

Rapid hydrolysis of NO2 at High Ionic Strengths of Deliquesced Aerosol Particles.

Nitrogen dioxide (NO2) hydrolysis in deliquesced aerosol particles forms nitrous acid and nitrate and thus impacts air quality, climate, and the nitrogen cycle. Traditionally, it is considered to proceed far too slowly in the atmosphere. However, the significance of this process is highly uncertain because kinetic studies have only been made in dilute aqueous solutions but not under high ionic strength conditions of the aerosol particles. Here, we use laboratory experiments, air quality models, and field measurements to examine the effect of the ionic strength on the reaction kinetics of NO2 hydrolysis. We find that high ionic strengths (I) enhance the reaction rate constants (kI) by more than an order of magnitude compared to that at infinite dilution (kI=0), yielding log10(kI/kI=0) = 0.04I or rate enhancement factor = 100.04I. A state-of-the-art air quality model shows that the enhanced NO2 hydrolysis reduces the negative bias in the simulated concentrations of nitrous acid by 28% on average when compared to field observations over the North China Plain. Rapid NO2 hydrolysis also enhances the levels of nitrous acid in other polluted regions such as North India and further promotes atmospheric oxidation capacity. This study highlights the need to evaluate various reaction kinetics of atmospheric aerosols with high ionic strengths.

A probe into the acid deposition mitigation path in China over the last four decades and beyond.

China currently has the highest acid deposition globally, yet research on its status, impacts, causes and controls is lacking. Here, we compiled data and calculated critical loads regarding acid deposition. The results showed that the abatement measures in China have achieved a sharp decline in the emissions of acidifying pollutants and a continuous recovery of precipitation pH, despite the drastic growth in the economy and energy consumption. However, the risk of ecological acidification and eutrophication showed no significant decrease. With similar emission reductions, the decline in areas at risk of acidification in China (7.0%) lags behind those in Europe (20%) or the USA (15%). This was because, unlike Europe and the USA, China's abatement strategies primarily target air quality improvement rather than mitigating ecological impacts. Given that the area with the risk of eutrophication induced by nitrogen deposition remained at 13% of the country even under the scenario of achieving the dual targets of air quality and carbon dioxide mitigation in 2035, we explored an enhanced ammonia abatement pathway. With a further 27% reduction in ammonia by 2035, China could largely eliminate the impacts of acid deposition. This research serves as a valuable reference for China's future acid deposition control and for other nations facing similar challenges.