Do we empathize humanoid robots and humans in the same way? Behavioral and multimodal brain imaging investigations.

Humanoid robots have been designed to look more and more like humans to meet social demands. How do people empathize humanoid robots who look the same as but are essentially different from humans? We addressed this issue by examining subjective feelings, electrophysiological activities, and functional magnetic resonance imaging signals during perception of pain and neutral expressions of faces that were recognized as patients or humanoid robots. We found that healthy adults reported deceased feelings of understanding and sharing of humanoid robots' compared to patients' pain. Moreover, humanoid robot (vs. patient) identities reduced long-latency electrophysiological responses and blood oxygenation level-dependent signals in the left temporoparietal junction in response to pain (vs. neutral) expressions. Furthermore, we showed evidence that humanoid robot identities inhibited a causal input from the right ventral lateral prefrontal cortex to the left temporoparietal junction, contrasting the opposite effect produced by patient identities. These results suggest a neural model of modulations of empathy by humanoid robot identity through interactions between the cognitive and affective empathy networks, which provides a neurocognitive basis for understanding human-robot interactions.

Pan AMPK Activation Protects Tubules in Rat Ischemic Acute Kidney Injury.

Acute Kidney Injury (AKI) is characterized by an abrupt decline in kidney function and has been associated with excess risks of death, kidney disease progression, and cardiovascular events. The kidney has a high energetic demand with mitochondrial health being essential to renal function and damaged mitochondria has been reported across AKI subtypes. 5' adenosine monophosphate-activated protein kinase (AMPK) activation preserves cellular energetics through improvement of mitochondrial function and biogenesis when ATP levels are low such as under ischemia-induced AKI. We developed a selective potent small molecule pan AMPK activator, compound 1, and tested its ability to increase AMPK activity and preserve kidney function during ischemia/reperfusion injury in rats. A single administration of 1 caused sustained activation of AMPK for at least 24 hours, protected against acute tubular necrosis, and reduced clinical markers of tubular injury such as NephroCheck and Fractional Excretion of Sodium (FENa). Reduction in plasma creatinine and increased Glomerular Filtration Rate (GFR) indicated preservation of kidney function. Surprisingly, we observed a strong diuretic effect of AMPK activation associated with natriuresis both with and without AKI. Our findings demonstrate that activation of AMPK leads to protection of tubular function under hypoxic/ischemic conditions which holds promise as a potential novel therapeutic approach for AKI. Significance Statement No approved pharmacological therapies currently exist for acute kidney injury. We developed Compound 1 which dose-dependently activated AMPK in the kidney and protected kidney function and tubules after ischemic renal injury in the rat. This was accompanied by natriuresis in injured as well as uninjured rats.

Determinants of Willingness to Use PrEP Among Gay and Bisexual Men in China Before Implementation: A Structural Equation Modeling Assessment.

With the recent endorsement of PrEP by the Chinese government, research is urgently needed to better understand factors impacting PrEP uptake among gay, bisexual, and other men who have sex with men (GBMSM) in China. This study examined willingness to use PrEP for HIV prevention among GBMSM in China through structural equation modeling. We examined the relationship among PrEP-related attitudes, subjective norms, PrEP-related knowledge and beliefs about medicines and willingness to use PrEP. The analysis showed a good fit between the data and both the measurement model (RMSEA = 0.060) and structural model (RMSEA = 0.054). Knowledge, attitudes, and subjective norms were significantly related to intention to use PrEP, whereas the effect of general beliefs about medicines was insignificant. These effect mechanisms point to the importance of designing interventions to support PrEP uptake that target knowledge, enhance positive attitudes about PrEP within social networks, and build positive social norms around PrEP among sexually active GBMSM.

Intimate Partner Violence Among Chinese Transwomen: Associations With Sexual Risk Behaviors and HIV Testing.

BACKGROUND: Intimate partner violence (IPV) is an emerging risk factor for HIV infection. Given the high vulnerability of and limited research on transwomen in China, we described IPV, sexual risk behaviors, HIV, and sexually transmitted infection (STIs) testing rates and results, and investigated the pathways that link IPV to HIV infection among this population. METHODS: We conducted a cross-sectional survey and collected blood samples for HIV and syphilis testing among transwomen in Shanghai, China (n = 199). With logistic regression, we examined sexual risk behaviors and HIV/STI testing history among participants with and without IPV experience. RESULTS: More than half of the respondents reported IPV (57.3%), and the prevalence of unprotected sex ranged from 51.9% (with sex workers) to 87.8% (oral sex); 85.9% had ever tested for HIV and 49.3% for other STIs. Self-reported positivity results were as follows: HIV (2.3%), herpes simplex virus type 2 (8.3%), gonorrhea (18.8%), and syphilis (17.8%). Laboratory-confirmed positivity values were 5.0% for HIV and 6.5% for syphilis. Respondents with a history of IPV were significantly less likely to report HIV testing in the past 12 months (adjusted odds ratio, 0.20; 95% confidence interval, 0.10-0.38). CONCLUSIONS: Transwomen self-reported a high prevalence of IPV, which was related to a lower probability of HIV testing. The prevalence of HIV and other STIs was lower than reported in previous studies of Chinese transwomen, whereas the HIV/STI testing rates were higher. Findings suggest transwomen in China are at risk for IPV and need enhanced HIV prevention services to promote HIV testing in an IPV setting.

First High-Resolution Emission Inventory of Levoglucosan for Biomass Burning and Non-Biomass Burning Sources in China.

Levoglucosan (LG) emitted from non-biomass burning (non-BB) sources has given rise to biased or even unreasonable source identification results when adopting LG as a distinct marker of biomass burning (BB). The estimation of LG emission and its spatiotemporal variation for various sources are the keys to reducing uncertainty. This study first developed a LG emission inventory for China from 25 sub-type sources belonging to eight categories, with a 3 km × 3 km spatial resolution and monthly distribution. The total LG emission in 2014 was 145.7 Gg. Domestic BB and open BB contributed 39.2 and 34.3% of the total emission. Non-BB sources, including municipal solid waste burning (9.7%), firework burning (9.6%), meat cooking (5.4%), domestic coal burning (1.5%), ritual item burning (0.2%), and industrial coal burning (0.1%), contributed to 26.5% of the total emission. LG emission varied spatially and temporally. Non-BB sources have a significant spatiotemporal impact on BB source contributions, even in high BB emission regions or in sowing, harvesting, and winter heating seasons. The local BB contributions have been substantially overestimated by 4.28-369% in previous studies, wherein LG was solely referred to as the BB source. By 2018, LG emission from BB might decrease to 63.9% of its total emission. This high-resolution LG emission inventory can be greatly useful for source identification studies in China. It also supports future research on the modeling of smoke aging and pollution control.

Evolution of Aerosol Optical Properties from Wood Smoke in Real Atmosphere Influenced by Burning Phase and Solar Radiation.

Emissions of light-absorbing black carbon (BC) and organic aerosol (OA) from biomass burning are presented as complex mixtures, which introduce challenges in modeling their absorbing properties. In this study, we chose typical residential wood burning emission and used a novel designed chamber to investigate the early stage evolution of plumes from different burning phases under real ambient conditions. The detailed mixing state between BC and OA was evaluated, on the basis of which optical modeling was performed to achieve a closure of aerosol-absorbing properties. Intensive secondary OA (SOA) formation was observed under solar radiation. OA from flaming conditions showed a higher absorptivity than from smoldering conditions, as OA is mostly internally and externally mixed with BC, respectively. For flaming (smoldering), the imaginary refractive index of OA (kOA) was initially at 0.03 ± 0.01 (0.001) and 0.15 ± 0.02 (0.05 ± 0.02) at λ = 781 and 405 nm, respectively, with a half-decay time of 2-3 h in light but a <40% decrease under dark within 5 h. The production of less-absorbing SOA in the first 1-2 h and possible subsequent photobleaching of chromophores contributed to the decrease of kOA. The enhanced abundance but decreased absorptivity of coatings on BC resulted in a relatively maintainable absorptivity of BC-containing particles during evolution.

Post-exposure prophylaxis: an underutilized biomedical HIV prevention method among gay, bisexual and other men who have sex with men in China.

Despite abundant evidence on its safety, tolerability and cost-effectiveness, post-exposure prophylaxis (PEP) has not been officially approved for non-occupational use in China. This study aims to assess awareness of, willingness to use, and actual experience with PEP in gay, bisexual and other men who have sex with men (GBM) in China and to explore potential associations between demographic, behavioral, and psychosocial factors and PEP-related outcomes. We recruited a convenience sample through community venue-based strategies, peer referrals, and online advertisement in four cities of China in 2018. We used bivariable and multivariable logistic regression to test associations between potential predictors and PEP outcomes. Over 60% of men reported having heard of PEP prior to the survey, 70% would be willing to use it if exposed to HIV, and 6% reported having used PEP. Awareness of PEP was associated with higher education, more frequent HIV testing, knowing someone who seroconverted in the past two years, having sex with only men in the past six months, and lower perceived risk of HIV infection. PEP willingness was associated with more frequent HIV testing, being worried about becoming HIV infected, prior awareness and favorable attitudes towards PEP among friends. Findings suggest PEP is an underutilized diomedical HIV prevention intervention among GBM in China. Clinical guidance on non-occupational PEP use, as well as communication campaigns targeting social networks of GBM are needed to address barriers to PEP awareness and uptake.

Do gay and bisexual men who conceal their same-sex behavior prefer different kinds of health services? Findings across four cities to inform client-centered HIV prevention in China.

BACKGROUND: In China, addressing disparities in the HIV epidemic among men who have sex with men (MSM) requires targeted efforts to increase their engagement and retention in prevention. In an effort to advance MSM-friendly HIV services within China, and informed by community-based partnerships, we tested whether MSM who have ever versus never disclosed their same-sex behavior to healthcare providers (HCP) differ in sociodemographic and behavioral characteristics as well as the qualities of sexual health services each group would prefer to access. METHODS: We conducted a cross-sectional survey among HIV-negative MSM who went to MSM-focused voluntary counseling and testing clinics in four cities in China. The survey was anonymous and collected information on sociodemographic characteristics, testing behaviors, sexual-health related behavior, and sexual health service model preferences. RESULTS: Of 357 respondents, 68.1% participants had ever disclosed same-sex behavior to HCPs when seeking advice for sexual health. Younger age (aOR = 1.04; 95% CI: 1.01-1.08), and worry of HIV acquisition (aOR = 1.39; 95% CI: 1.05-1.84) were associated with higher odds of past disclosure. The availability of comprehensive sexual health services was one of the most valued characteristics of the ideal sexual health clinic. Those who ever disclosed and never disclosed differed significantly in their ranking of the importance of three out of ten dimensions: sexual health counseling services available (M = 3.99 vs. M = 3.65, p = .002), gay identity support available (M = 3.91 vs. M = 3.62, p = .016) and clinic collaborates with a gay CBO (M = 3.81 vs. M = 3.56, p = .036). CONCLUSIONS: Our hypothesis that MSM who had disclosed versus never disclosed same-sex behavior would differ in the value they placed on different dimensions of sexual health service was partially borne out. As health authorities in China decide on implementation models for pre-exposure prophylaxis (PrEP) delivery and specifically within which institutions to integrate PrEP services, the preferences of target populations should be considered to develop comprehensive, patient-centric and LGBT-friendly services.

Characterization and source identification of PM2.5-bound polycyclic aromatic hydrocarbons in urban, suburban, and rural ambient air, central China during summer harvest.

Characterization and source identification of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) are conducted in urban Wuhan (WH), suburban Pingdingshan (PDS), and rural Suizhou (SZ) in China during summer harvest. This study analyzes 16 priority PAHs with 38 PM.2.5 samples in June. PAHs had similar physical-chemical properties like polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), which had been listed as Priority Pollutants. The concentration and detection frequency of OCPs and PCBs were considerably lower than those of PAHs in PM2.5. Results indicate that PDS adjoining the highway has the highest PM2.5-bound PAHs. SZ possesses the lowest concentration of PAHs. Principal component analysis and multivariate linear regression model and molecular diagnostic ratio distinguish the sources. Vehicle emissions and coal combustion are extracted in three sites, while the source of PDS also includes gas combustion. SZ was affected by gas combustion and petroleum. The potential source contribution function and the concentration-weighted trajectory track the potential pollution area. The sampling places might be affected by the local sources and short distance transmission cannot be neglected. The incremental lifetime cancer risks (ILCRs) model evaluates the exposure risk of PAHs. According to the ILCR model, WH and PDS are exposed to harmful PAHs. By contrast, SZ is a substantially safe place.

Risk Behavior Not Associated with Self-Perception of PrEP Candidacy: Implications for Designing PrEP Services.

In a study of sexually-active HIV-negative men who have sex with men (MSM) in China, we compared behavioral indication for pre-exposure prophylaxis (PrEP) based on risk criteria to self-perception of PrEP candidacy (SPC) and explored factors associated with SPC. Of 708 MSM surveyed, 323 (45.6%) were behaviorally-indicated for PrEP, among whom 42.1% self-perceived as appropriate PrEP candidates. In a multivariable model we found no association between sexual behavior nor HIV risk perception and SPC but found that higher perceived benefits of PrEP, increased frequency of HIV testing, and low condom use self-efficacy were positively-associated with SPC. In a sub-analysis restricted to MSM behaviorally-indicated for PrEP, relationship-factors were also significant. Our findings suggest that PrEP implementers should look beyond risk criteria to consider shared decision-making tools that support individuals to assess whether they are appropriate PrEP candidates based on their existing HIV prevention strategies, sexual health goals, and relationship dynamics.

Polycyclic aromatic hydrocarbons (PAHs) in agricultural soils from Ningde, China: levels, sources, and human health risk assessment.

Soil-bound polycyclic aromatic hydrocarbons (PAHs) in farmland are critical to human health. The level, composition, source, and cancer risk of sixteen PAHs in agricultural soil from Ningde, China, were investigated. The results indicated that the total concentrations of 16 PAHs ranged from 77.3 to 1188 ng g-1, with a mean value of 406 ng g-1. Five-ring PAHs were found to have the highest concentrations (148 ± 133 ng g-1), followed by four-ring (120 ± 101 ng g-1), three-ring (61.9 ± 54.2 ng g-1), six-ring (44.6 ± 61.0 ng g-1), and two-ring (31.3 ± 31.0 ng g-1). Employing positive matrix factorization (PMF), four PAH sources including biomass burning (36.3%), coal combustion (35.5%), traffic emissions (16.4%), and coke source (11.8%) were identified. Incremental lifetime cancer risk (ILCR) results showed that ILCR values ranged from 7.1 × 10-4 to 1.1 × 10-3, which will cause moderate-to-high cancer risk to human health mainly via the soil ingestion and dermal contact exposure pathways. The source-oriented results indicated that coal combustion (32.7%), traffic emission (34.3%), and biomass burning (32.4%) had similar contributions to the total cancer risk. Therefore, more attention should be paid to these pyrolysis-originated sources to protect humanity from the health risk of PAHs.

Potentially Toxic Metals in Soil and Dominant Plants from Tonglushan Cu-Fe Deposit, Central China.

Twenty-one soil samples and two dominant plant species (Elsholtzia splendens and Imperata cylindrical) were collected in Tonglushan Cu-Fe deposit, central China. Chemical analysis results showed that the soil contained low-level nutrients and high concentrations of potentially toxic metals. The geoaccumulation index results indicated that the study area was polluted by Cu-Zn-Cd-Pb. The levels of Cu in plant species were highest, followed by Zn, Pb, and Cd. The highest levels of Zn (261 mg kg-1), Cd (6.33 mg kg-1) and Pb (12.6 mg kg-1) were found in the leaf of Elsholtzia splendens and the highest concentration of Cu (1158 mg kg-1) was found in the root of Imperata cylindrica. Potentially toxic metals uptake and accumulation abilities were investigated by the bioconcentration factor and translocation factor, respectively. The results suggested that the Elsholtzia splendens may be a suitable candidate for Cd clean up using phytoextraction.

Biomass burning contributed most to the human cancer risk exposed to the soil-bound PAHs from Chengdu Economic Region, western China.

The purpose of this study was to assess the human cancer risk due to the exposure to the soil-bound polycyclic aromatic hydrocarbons (PAHs) from Chengdu Economic Region (CER), western China with the main concern on cancer risk source apportionment. The total concentrations of sixteen PAHs ranged from 12.5 to 75431 ng g-1, with a mean value of 3106 ng g-1, which suggested that the most areas of CER were contaminated. Source apportionment of PAHs was conducted by the positive matrix factorization (PMF) model and the biomass burning contributed most (63.6%) to the total PAHs, followed by petroleum combustion (16.0%), coke source (11.3%), and petrogenic source (9.2%). Results from incremental lifetime cancer risk (ILCR) calculation showed that soil ingestion exerted the highest cancer risk (accounted for 98.1 - 99.3% of the total cancer risk) on human health among three different exposure pathways, followed by dermal contact (0.66 - 1.83%) and inhalation (0.03 - 0.04%). Among different age groups, adult suffered the highest cancer risk via any exposure pathways. Based on PMF and ILCR methods, the cancer risk source apportionment was conducted and the biomass burning showed moderate cancer risk. The petrogenic, coke, and petroleum sources showed low cancer risks to human. To analyze the sensitivity of the parameters used in ILCR calculation, Monte Carlo simulation was employed. The results indicated that the contribution of each source and exposure duration (ED) were the influential parameters on human health associated with soil-bound PAHs. Therefore, much attentions should be paid to biomass burning to avoid cumulative cancer risk.

[Simultaneous determination of eight hydroxyl naphthoquinones in different parts of Arnebiae euchroma by HPLC].

This present study is to develop an HPLC method for simultaneous determination of eight hydroxyl naphthoquinones, shikonin, ß-hydroxy-isovalerylshikonin, acetylshikonin, ß-acetoxy-isovalerylshikonin, deoxyshikonin, isobutyrylshikonin, ß,ß'-dimethylacrylshikonin and isovalerylshikonin. The eight constituents were measured on a Waters Xbridge C18 column (4.6 mm×250 mm，5 µm) with isocratic elution of acetonitrile-0.05% formic acid solution (70∶30) at a flow rate of 1.0 mL•min⁻¹. The detection wavelength was 275 nm and the column temperature was 30 ℃. The results of content determination indicated that significant differences of the eight compounds exist in every part of Arnebia euchroma，in which the highest part was the root bark, followed with the root, then the stem residues. The content of the xylem of root and aerial part was lower than the above parts. The results provided scientific basis for the medicinal parts of A. euchroma.

Female streetwalkers' perspectives on migration and HIV/STI risks in a changing economic and social environment: a qualitative study in Shanghai, China.

China's 30-year economic boom has created a unique social and economic market for commercial sex, as well as for a workforce of migrant women from rural China. This qualitative study explores the impact of the rapidly changing social and economic environment on migration patterns, knowledge of sexually transmitted infections (STIs), STI risk behaviours and health beliefs among female streetwalkers in Shanghai. Qualitative data were collected in 2010 through semi-structured in-depth interviews with 16 streetwalkers to characterise their migration passages, sexual health and behaviours, and peer networks. Many streetwalkers reported histories of childhood impoverishment, of family or partner violence or trauma, of migration consistent with the timeline and routes of economic development and of a scarcity in health, social or economic support. Their knowledge of the prevention and treatment of HIV and STIs was limited. They had little bargaining power on condom use and the majority resorted to vaginal douching and self-management with antibiotics as preventative measures. The study identifies streetwalkers' perspectives on the changing environment, their options and actions and, finally, HIV/STI risks that were unique to this hidden population.

Multi-Threshold Recurrence Rate Plot: A Novel Methodology for EEG Analysis in Alzheimer's Disease and Frontotemporal Dementia.

This study introduces Multi-Threshold Recurrence Rate Plots (MTRRP), a novel methodology for analyzing dynamic patterns in complex systems, such as those influenced by neurodegenerative diseases in brain activity. MTRRP characterizes how recurrence rates evolve with increasing recurrence thresholds. A key innovation of our approach, Recurrence Complexity, captures structural complexity by integrating local randomness and global structural features through the product of Recurrence Rate Gradient and Recurrence Hurst, both derived from MTRRP. We applied this technique to resting-state EEG data from patients diagnosed with Alzheimer's Disease (AD), Frontotemporal Dementia (FTD), and age-matched healthy controls. The results revealed significantly higher recurrence complexity in the occipital areas of AD and FTD patients, particularly pronounced in the Alpha and Beta frequency bands. Furthermore, EEG features derived from MTRRP were evaluated using a Support Vector Machine with leave-one-out cross-validation, achieving a classification accuracy of 87.7%. These findings not only underscore the utility of MTRRP in detecting distinct neurophysiological patterns associated with neurodegenerative diseases but also highlight its broader applicability in time series analysis, providing a substantial tool for advancing medical diagnostics and research.

Mechanism of acupuncture in attenuating cerebral ischaemia-reperfusion injury based on nuclear receptor coactivator 4 mediated ferritinophagy.

OBJECTIVE: To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury (CIRI) and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4 (NCOA4) mediated ferritinophagy. METHODS: Sprague-Dawley male rats were divided into four groups: the sham group, model group, acupuncture group, and sham acupuncture group. After 2 h of middle cerebral artery occlusion (MCAO), reperfusion was performed for 24 h to induce CIRI. The rats were treated with acupuncture at the Neiguan (PC6) and Shuigou (GV26) acupoints. Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion. Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion. The malondialdehyde (MDA) and ferrous iron (Fe2+) levels were observed after 24 h of reperfusion using an assay kit. Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1 (FTH1) at 24 h after reperfusion. Moreover, the colocalization of ferritin with neurons, NCOA4 with microtubule-associated protein 1 light chain 3 (LC3), and NCOA4 with ferritin was visualized using immunofluorescence staining. RESULTS: Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group. Following CIRI, the expression of NCOA4, LC3 and FTH1 was increased, which enhanced ferritinophagy and induced an inappropriate accumulation of Fe2+ and MDA in the ischaemic brain. However, acupuncture dramatically downregulated the expression of NCOA4, LC3 and FTH1, inhibited the overactivation of ferritinophagy, and decreased the levels of MDA and Fe2+. CONCLUSIONS: Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.

Achievements and challenges in improving air quality in China: Analysis of the long-term trends from 2014 to 2022.

Due to the implementation of air pollution control measures in China, air quality has significantly improved, although there are still additional issues to be addressed. This study used the long-term trends of air pollutants to discuss the achievements and challenges in further improving air quality in China. The Kolmogorov-Zurbenko (KZ) filter and multiple-linear regression (MLR) were used to quantify the meteorology-related and emission-related trends of air pollutants from 2014 to 2022 in China. The KZ filter analysis showed that PM2.5 decreased by 7.36 ± 2.92% yr-1, while daily maximum 8-h ozone (MDA8 O3) showed an increasing trend with 3.71 ± 2.89% yr-1 in China. The decrease in PM2.5 and increase in MDA8 O3 were primarily attributed to changes in emission, with the relative contribution of 85.8% and 86.0%, respectively. Meteorology variations, including increased ambient temperature, boundary layer height, and reduced relative humidity, also contributed to the reduction of PM2.5 and the enhancement of MDA8 O3. The emission-related trends of PM2.5 and MDA8 O3 exhibited continuous decrease and increase, respectively, from 2014 to 2022, while the variation rates slowed during 2018-2020 compared to that during 2014-2017, highlighting the challenges in further improving air quality, particularly in simultaneously reducing PM2.5 and O3. This study recommends reducing NH3 emissions from the agriculture sector in rural areas and transport emissions in urban areas to further decrease PM2.5 levels. Addressing O3 pollution requires the reduction of O3 precursor gases based on site-specific atmospheric chemistry considerations.

Influence of pollution control measures on the reduction of black carbon in an urban site of megacity, Tianjin, China based on ground-monitored and MERRA-2 reanalysis data.

The concentration of particulate matter (PM) has been reduced significantly with the implementation of air pollution control plans in Tianjin. However, as an important component of PM that can lead to global warming and adverse health effects, the influence of pollution control measures (PCM) on black carbon (BC) has been less studied. In this study, ten years of BC concentration satellite-based reanalysis data were collected from MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications, Version 2), and their reliability was verified using ground-monitored BC data. Using the proposed Kolmogorov-Zurbenko and artificial neural network (KZ-ANN) model, the influences of meteorology and emission measures were separated. The results indicated that the overall meteorological conditions were not conducive to BC diffusion, especially in autumn and winter with low temperature, surface solar radiation, boundary layer height, and high atmospheric pressure, all of which increased the BC concentration. This study also found that although a significant reduction in BC emissions was observed in Tianjin (the total emissions of BC in 2020 dropped by 52 % compared with the level in 2013), the change in emission-influenced BC was relatively low (the concentration of emission-influenced BC in 2022 dropped by only 2.39 % compared to that in 2013). The reduction of emission-influenced BC concentration during the air pollution prevention control and action plan (APPC) was higher than the level during of the three-year action plan for winning the blue sky defense war (abbreviated as the Blue Sky Defense War). In addition, the lockdown measures during the Corona Virus Disease 2019 (COVID-19) did not have beneficial effect on the reduction of emission-influenced BC concentration. This phenomenon can be explained by the long-range transport of BC from surrounding areas, which was also proven by the results of the backward trajectory analysis. Therefore, efforts on emissions reduction in Tianjin were diminished. It is necessary to cooperate with the governments in surrounding areas to implement joint BC control measures, especially in autumn and winter.

[Impacts of Emission and Meteorological Conditions on Air Pollutants at Various Sites Around the COVID-19 Lockdown in Wuhan].

The random forest algorithm was used to separate the mass concentrations of six air pollutants (SO2, NO2, CO, PM10, PM2.5, and O3) contributed by emissions and meteorological conditions. Their variations for five types of sites including Wuhan's central urban, suburb, industrial, the third ring road traffic, and urban background sites were investigated. The results showed that the values of PM2.5/CO, PM10/CO, and NO2/CO during the lockdown period decreased by 10.8-21.7, 9.34-24.7, and 14.4-22.1 times compared with the period before the lockdown, indicating that the contributions of emissions to PM2.5, PM10, and NO2 were reduced. O3/CO increased by 50.1-61.5 times, implying that the secondary formation increased obviously. The contributions of emissions to various types of pollutants all increased after the lockdown. During the lockdown period, affected by the operation of some uninterrupted industrial processes, PM2.5 concentrations in industrial areas dropped the least (20.5%). Compared with the lockdown period, residential activities, transportation, and industrial production were basically restored after the lockdown, resulting in the alleviation of the reduction in PM2.5 emission-related concentrations. The increase in emission-related O3 concentrations could be associated with the decreased NO and PM2.5 concentrations during the lockdown period. The elevated O3 partially offset the improved air quality brought by the reduced NO2and PM2.5 concentrations. After the lockdown, ρ(O3) related with meteorology at the suburban and urban background sites increased by 16.2 µg·m-3 and 16.1 µg·m-3, respectively, which could be attributed to the increased ambient temperature and decreased relative humidity. The decrease in PM2.5 and increase in O3 concentrations caused by reduced traffic and industrial emissions at the third ring road traffic and central urban regions can provide reference for the current coordinated and precise control of PM2.5 and O3 in subregions.