[Epidemiological characteristics of local visceral leishmaniasis in Beijing Municipality from 2021 to 2023].

OBJECTIVE: To investigate the epidemiological characteristics of local visceral leishmaniasis in Beijing Municipality from 2021 to 2023, so as to provide insights into formulation of the visceral leishmaniasis control strategy. METHODS: Epidemiological data of visceral leishmaniasis cases reported in Beijing Municipality from 2021 to 2023 were collected from the National Health Informatization Disease Prevention and Control Information System, and the epidemiological characteristics of local visceral leishmaniasis cases were analyzed using a descriptive epidemiological method. In November 2021 and 2023, 50 to 100 permanent residents were voluntarily selected within a 100 meter radius of sites where patients lived or acquired Leishmania infections, and venous blood was sampled for anti-Leishmania antibody testing. Venous blood was sampled from dogs for anti-Leishmania antibody testing in natural villages where patients lived or acquired Leishmania infections, or in districts where Leishmania infected dogs were reported. In addition, sandflies were captured with CO2 mosquito traps and fine mesh nets in natural villages where patients lived or acquired Leishmania infections from May to September, 2021 and 2023, for sandfly species identification. RESULTS: A total of 4 local visceral leishmaniasis cases were reported in Beijing Municipality from 2021 to 2023, with ages of 2 to 77 years, and acquiring Leishmania infections in Mentougou District (2 cases), Changping District (1 case), and Yanqing District (1 case). The anti-Leishmania antibody testing was all negative in 73 human blood samples and the sero-prevalence of anti-Leishmania antibody was 25.00% in 36 venous blood samples from domestic dogs in 2021, with a total of 4 520 Phlebotomus chinensis captured. The sero-prevalence of anti-Leishmania antibody was 0.51% in 198 human blood samples and 13.58% in 243 venous blood samples from domestic dogs in 2023, with 16.10%, 25.00%, 17.78% and 3.13% sero-prevalence in dogs sampled from Mentougou District, Changping District, Yanqing District and Haidian District, respectively (P = 0.011), while a total of 1 712 Ph. chinensis were captured, including 1 421 female sandflies (86.54%). CONCLUSIONS: The prevalence of local visceral leishmaniasis was low in Beijing Municipality from 2021 to 2023; however, there is a risk of further spread in the epidemic foci. Intensified visceral leishmaniasis surveillance and control is recommended.

[Spatial and Temporal Characteristics of Fractional Vegetation Cover and Its Response to Urbanization in Beijing].

Exploration of the spatiotemporal changes in fractional vegetation cover （FVC） and its response characteristics to urbanization is of great significance for urban ecological protection and planning in Beijing. This study analyzed the spatiotemporal characteristics of vegetation cover changes in Beijing from 2000 to 2020 using the Theil-Sen Median and Mann-Kendall methods based on a long-term time series vegetation cover dataset. Then, this study used the urbanization index as a key indicator of spatial urbanization and utilized the transect line and global grid analysis methods to investigate the response characteristics of FVC to different urbanization gradients. The results indicated that： ① FVC changes showed spatial and temporal heterogeneity. From 2000 to 2020, Beijing was predominantly covered by high vegetation, accounting for 65.22% of the total area, which was mainly distributed in ecological conservation areas consistent with the Jundu, Xishan, and Yaji Mountain ranges. The FVC presented an overall positive development trend, with a decreasing trend of areas with low FVC. The increase in FVC was significant （by 28.68%）, mainly distributed in ecological conservation areas and within a range of 10-12 km in concentric circles centered around Tiananmen Square. The urbanization index and FVC change rate were relatively high in Haidian District, Chaoyang District, Fengtai District, Shijingshan District, and Changping District. ② The artificial land surface in 2000, 2010, and 2020 was 9.69%, 13.64%, and 21.19%, respectively, with significant spatial agglomeration and strong spatial heterogeneity. During the urbanization process in Beijing, the increase in artificial land surface reached 11.5%, with the conversion from arable land to artificial land surface accounting for 53.83% of the total land use conversion area. ③ There was a significant negative correlation between FVC and the urbanization index, indicating that urbanization had a negative impact on regional FVC. However, as the urbanization process stabilized, this negative correlation tended to gradually weaken. Although the central urban areas were mainly characterized by low FVC, there was a significant increasing trend in the FVC, indicating a positive development in the FVC and an improvement in regional ecological quality, which was closely related to the governance of the mountain-water-forest-field-lake-grass-sand system. The results of the study can provide a basis for the development of vegetation restoration programs and ecological management measures in Beijing.

Posterior Eye Shape in Myopia.

Purpose: To explore prevalence and associated factors of abnormalities of the posterior eye shape in dependence of axial length. Design: Population-based study. Participants: Of the participants (n = 3468) of the Beijing Eye Study, we included all eyes with an axial length of ≥25 mm, and a randomized sample of eyes with an axial length of <25 mm. Methods: Using 30°-wide, serial horizontal, and fovea-centered radial, OCT images, we examined location and depth of the most posterior point of the retinal pigment epithelium/Bruch's membrane line (PP-RPE/BML). Main Outcome Measures: Prevalence and depth of an extrafoveal PP-RPE/BML. Results: The study included 366 eyes (314 individuals). On the radial OCT scans, the PP-RPE/BML was located in the foveola in 190 (51.9%) eyes, in 121 (33.1%) eyes in the 6 o'clock part of the vertical meridian (distance to foveola: 1.73 ± 0.70 mm), and in 54 (14.8%) eyes in the 12 o'clock part of the vertical meridian (fovea distance: 2.01 ± 0.66 mm). On the horizontal OCT scans, the PP-RPE/BML was located in the foveola in 304 (83.1%) eyes, between foveola and optic disc in 36 (9.8%) eyes (fovea distance: 1.59 ± 0.76 mm), and temporal to the foveola in 26 (7.1%) eyes (fovea distance: 1.20 ± 0.60 mm). Higher prevalence of an extrafoveal PP-RPE/BML correlated with longer axial length (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.28, 1.89), higher corneal astigmatism (OR: 1.78; 95% CI: 1.14, 2.79), and female sex (OR: 2.74; 95% CI: 1.30, 5.77). The curvature of the RPE/BML at the posterior pole was similar to the RPE/BML curvature outside of the posterior pole in 309 (84.4%) eyes, and it was steeper (i.e., smaller curvature radius) in 57 (15.6%) eyes. In these eyes, axial length was longer (24.41 ± 1.78 mm versus 27.74 ± 1.88 mm; P < 0.001). Conclusions: With longer axial length, the foveola is more often located outside of the geometrical posterior pole. It may be of importance for biometric axial length measurements. An extrafoveal location of the PP-RPE/BML may be due to an axial elongation-associated, meridionally asymmetric enlargement of Bruch's membrane in the fundus midperiphery. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Prevalence and associations of dome-shaped maculas. The Beijing Eye Study.

PURPOSE: To explore the prevalence and associated factors of a dome-shaped macula (DSM) in a general population. METHODS: Out of the population-based Beijing Eye Study cohort (n = 3468 participants), the investigation included all eyes with an axial length of ≥25 mm, and a randomized sample of eyes with an axial length of <25 mm. Using optical coherence tomographic (OCT) images, we examined presence and height of DSMs, defined as an inward convexity of the foveal retinal pigment epithelium (RPE)/Bruch's membrane (BM) line, detectable in at least two OCT scans perpendicularly orientated to each other. RESULTS: The study cohort consisted of 366 eyes (314 individuals) with a mean age of 63.7 ± 9.7 years and a mean axial length of 24.8 ± 2.1 mm (median: 25.1 mm; range: 18.96-30.88 mm). Prevalence of DSMs (found in 6/366 eyes; 1.9%; 95%CI: 1.0, 3.0) increased from 0/125 (0%) in non-myopic eyes to 1/152 (0.7%; 95%CI: 0.0, 2.0) in moderately myopic eyes, and to 6/83 (7.2%; 95%CI: 1.7, 12.7) in the highly myopic group. In multivariable analysis, higher DSM prevalence corelated with longer axial length (OR: 2.05; 95%CI: 1.36, 3.08; p < 0.001) and higher stage of myopic macular degeneration (OR: 1.08; 95%CI: 1.01, 1.16; p = 0.03). The mean maximal DSM height was 139 ± 107 µm (median: 100 µm; range: 25-350 µm). It was associated with higher stage of myopic macular degeneration (beta: 0.24; p < 0.001) and higher prevalence of macular BM defects (beta: 0.17; p < 0.001). None of the DSMs showed a serous retinal detachment or relative choroidal thickening. CONCLUSIONS: Higher DSM prevalence correlated non-linearly with longer axial length, with DSM height increasing with the presence of a BM defect. DSMs may be associated with an axial elongation-related BM overproduction in the fundus midperiphery in all meridians.

The impact of lactic acid bacteria inoculation on the fermentation and metabolomic dynamics of indigenous Beijing douzhi microbial communities.

Background: Douzhi, a traditional Chinese fermented beverage, features microbial communities primarily composed of lactic acid bacteria (LAB). As fermented foods continue to gain recognition and popularity, douzhi is attracting growing interest. However, investigation of the critical aspects of douzhi's fermentation processes, including fermentation characteristics and microbial community dynamics, remains vital for enhancing food safety and quality for douzhi, as well as for similar fermented food products. Method: In this study, we collected douzhi microbial communities from four chain stores, using them as fermentation starter cultures. The microbial dynamics of the fermentation were analyzed, focusing on the inoculation of LAB strains and the transition from a mung bean-based matrix to skimmed milk. The metabolomic profiles of the fermented mung bean matrices were also studied. Results: Douzhi samples obtained from representative chain stores were found to be overwhelmingly dominated by LAB. When inoculated along with the douzhi community, both LAB strains exhibited notable and substantial reductions in the pH value of the designated mung bean matrices compared to those inoculated indigenous microbiota. Specifically, Lactiplantibacillus plantarum CGMCC 1.1856 retained its population, whereas Pediococcus pentosaceus CGMCC 1.2695 exhibited a decrease in relative abundance. Using skimmed milk as a fermentation substrate instead of the mung bean matrix resulted in significant shifts in microbial communities, particularly leading to an increase in Escherichia sp. The metagenomic analyses and functional predictions illustrated that various metabolic functions were enhanced during the fermentation process due to LAB inoculation. The liquid chromatography-mass spectrometry based metabolomic analysis revealed that the inoculation of Lactiplantibacillus plantarum and Pediococcus pentosaceus in mung bean matrix did not introduce new metabolites but significantly altered the concentration and profile of existing metabolites, especially increased low molecular carbohydrates, which may enhance the nutritional potential of the fermented product. Discussion: This study examines the microbial dynamics of douzhi microbiota fermentation, emphasizing the role of lactic acid bacteria in enhancing fermentation activity and metabolite profiles. These insights contribute to improving manufacturing processes and ensuring the safety and quality of douzhi and similar fermented foods.

[Effects of Meteorological Conditions in Summer and Early Autumn on PM2.5 and O3 Pollution in Beijing-Tianjin-Hebei and Surrounding Areas].

PM2.5 pollution remains prominent in autumn, whereas O3 pollution gradually manifests in summer. To understand the dual high characteristics and meteorological effects of PM2.5 and O3 in the summer and early autumn of 2021 in the Beijing-Tianjin-Hebei and surrounding areas, the spatiotemporal distribution characteristics of PM2.5 and O3 concentrations, as well as meteorological conditions, subtropical high index, and weather situation in the Beijing-Tianjin-Hebei and surrounding areas were analyzed. The results showed that PM2.5 concentration and DPO3 （O3 daily maximum 8h mean minus O3 concentration at 06：00） from June to September 2021 decreased compared with those in the same period in 2020 and 2022, and high concentrations were mainly occurring in June. The overall PM2.5 concentration and DPO3 showed a gradual decrease from the middle to the north and south, with synchronous spatiotemporal changes. The hourly value of PM2.5 concentration presented a multimodal distribution, reaching the peak at 07：00-10：00 and 22：00-24：00. O3 concentration showed an opposite trend of change with PM2.5 concentration, reaching their peak from 14：00-16：00. When DPO3 and the concentration of PM2.5 were high, the characteristics of near-surface meteorological elements were characterized by temperatures ranging from 24.0-28.0℃, relative humidity concentrated at 58.4%-76.3%, and wind speeds ranging from 1.5-3 m·s-1. There was a high lag correlation between the subtropical high index and DPO3. When the subtropical high was farther and stronger from the Beijing-Tianjin-Hebei and surrounding areas, DPO3 was higher. The major weather patterns with both high PM2.5 and O3 concentrations in the study area were near surface low-pressure front, high-pressure type, and frontal type. The high altitude was controlled by high-pressure ridges, and the subtropical high ridge line was stable between 21°-28°N.

Investigating spatio-temporal variations and contributing factors of land use-related carbon emissions in the Beijing-Tianjin-Hebei Region, China.

The land use change is the primary factor in influencing the regional carbon emissions. Studying the effects of land use change on carbon emissions can provide supports for the development policies of carbon emission. Using land use and energy consumption data, this study measures carbon emissions from land use dynamics in the Beijing-Tianjin-Hebei region from 2000 to 2020. The standard deviation ellipse model is employed to investigate the distribution characteristics of the spatial patterns of carbon emissions, while the Geographically and Temporally Weighted Regression (GTWR) model is used to examine the contributing factors of carbon emissions and their spatial and temporal heterogeneity. Results indicate a consistently increasing trend in carbon emissions from land use in the Beijing-Tianjin-Hebei region from 2000 to 2020. Construction land is characterized with both the primary source and an increasing intensity of carbon emissions. Besides, the spatial distribution of carbon emissions from land use in the Beijing-Tianjin-Hebei region demonstrates an aggregation pattern from in the northeast-southwest direction towards the center, with a greater aggregation trend in the east-west direction compared to that in the south-north direction. During the study period, a positive correlation was documented between carbon emissions and factors including total population, economic development level, land use degree, and landscape patterns. This correlation showed a decreasing trend and reached a stable level at the end of the study period. Moreover, the analysis showed a negative correlation between industrial structure and carbon emissions, which showed an increasing trend and reached a relatively high level at the end of the study period.

Spillover effects of structure-adjustment pollution reduction measures in China's iron and steel industry.

The iron and steel industry (ISI) is a significant source of sulfur dioxide and particulate matter pollution in China. Existing research on regional environmental regulation or ISI emission reduction strategies tends to overlook spillover effects and the enterprise perspective. During the heating season, production limitations in ISI are potential policy measures for achieving structural emission reductions in heavily polluted cities in China's Jing-Jin-Ji and surrounding regions. We adopt a bottom-up modeling approach, incorporating effective production time to describe enterprise behavior and establishing a quantitative trade model based on trade theory. By modeling three types of production restriction policies outlined in policy documents, we evaluate the emission reduction effects of structure-adjustment measures using the example of reduced effective production time for steel-producing enterprises in the air pollution transmission channel in the Beijing-Tianjin-Hebei area. The results indicate the following: (1) Reducing the effective production time of ISI enterprises can help decrease domestic production value and total factor productivity in pollution-intensive industries, including but not limited to ISI. It also leads to reduced emissions of various pollutants in the implementation regions. (2) Due to interprovincial trade and input-output linkages, structural reduction measures in certain regions have implications for almost all other provinces' industrial structures. Differences in initial industrial structures, factor endowments, and geographical locations contribute to varying directions and magnitudes of industrial structural changes. Pollution-intensive industries' share tends to increase higher in less developed regions. (3) Our estimated pollution reduction is smaller compared to the literature evaluating clean air policies in similar regions using top-down strategies. This discrepancy arises because we analyze a single policy tool rather than modeling industry-wide emission fluctuations from the top down. Additionally, our modeling approach allows us to examine dynamic changes in comparative advantages. The increase in production scale for certain industries in policy-affected regions partially offsets the decline in pollution emissions. These findings enhance our understanding of structure-adjustment reduction measures' role and highlight their potential advantages and limitations.

Molecular epidemiology of Mycobacterium tuberculosis in Ecuador: Recent advances and future challenges.

Tuberculosis (TB) is one of the three leading causes of death from a single infectious agent, Mycobacterium tuberculosis (MTB), together with COVID-19 and HIV/AIDS. This disease places a heavy burden on countries with low socio-economic development and aggravates existing inequalities. For the year 2021, estimations for Ecuador were 8500 TB cases, of which 370 were associated to multiple drug resistance (TB-MDR), and 1160 deaths. In the same year, Ecuador notified 5973 total cases, 401 of them were TB-MDR, pointing out an under diagnosis problem. The few molecular epidemiology studies available conclude that L4 is the most prevalent MTB lineage in Ecuador (with LAM as the main L4 sublineage), but L2-Beijing family is also present at low prevalence. Nevertheless, with less than 1 % MTB isolates genetically characterized by either MIRU-VNTR, spolygotyping or WGS to date, molecular epidemiology research must me improved to assist the TB surveillance and control program in Ecuador.

Metabolomics Reveals Glycerophospholipids, Peptides, and Flavonoids Contributing to Breast Meat Flavor and Benefit Properties of Beijing-You Chicken.

Unique metabolites contribute to the performance of meat flavor and potential function. In this study, UHPLC-Q Exactive HF-X-based metabolomics and multivariate analysis were applied to explore the characteristic metabolites in the breast meat of Beijing-You chicken (BYC) aged 150, 300, and 450 days (D150, D300, and D450). Based on the criteria of variable importance in the projection (VIP) > 1 and p < 0.05, a total of 154 and 97 differential metabolites (DMs) were screened out compared with D450 (D450 vs. D150, D450 vs. D300), respectively. In general, the relative content of carnosine, L-L-homoglutathione, demethyloleuropein, neohesperidin dihydrochalcone, 7-chloro-2-(3,4-dimethoxyphenyl)-3,5-dihydroxy-6,8-dimethoxy-4H-chromen-4-one, glycerophospholipids, exhibited the highest abundance at D450, while balenine, anserine, L-beta-aspartyl-L-leucine, glutathione, oxidized glutathione, stearoylcarnitine, ganoderic acid alpha, oleuroside, Lysoglycerophospholipid species (LGP) presented a downward trend with age. These 210 DMs were involved in 10 significantly enriched pathways related to the synthesis and metabolism of amino acids, peptides, and glycerophospholipid, such as glutathione metabolism, histidine metabolism, glycerophospholipid metabolism, arginine biosynthesis, tyrosine metabolism, and lysine degradation. In conclusion, this work could not only facilitate a better understanding of the differences of chicken flavor and benefit properties with age, but also provide potential valuable bioactive compounds for further research.

Decreased nitrogen deposition in Beijing over the recent decade and its implications.

Atmospheric reactive nitrogen (Nr) deposition has been modified significantly by human activities such as agriculture and fossil fuel combustion. Understanding the changes in Nr deposition is essential for maintaining the functionality and sustainability of ecosystems. Taking Beijing as a case study, we report long-term measurements of wet Nr deposition from 1999 to 2022 and dry Nr deposition from 2010 to 2022 and their relationship with China's air pollution control. Total Nr deposition to Beijing decreased by 34 % during 2010-2022, mainly caused by a decrease in dry N deposition by 54.27 %, from 47.86 kg N ha-1 yr-1 in 2010-2014 to 21.89 kg N ha-1 yr-1 in 2018-2022; reduced and oxidized N in dry deposition decreased by 29.93 % and 72.05 %, respectively. This was a result of the "Action Plan for Prevention and Control of Air Pollution (APCP)" and the implementation of the "Zero Growth in Fertilizer Use by 2020" in 2015. Our ground-based measurements provide evidence to support recent achievements in air pollution control and a reference and guidance for other regions of China and other countries for abating Nr pollution.

Effects of the Beijing genotype on latent tuberculosis infection, TB disease risk, and clustering of TB cases.

BACKGROUND: The Beijing genotype of Mycobacterium tuberculosis (Mtb) has sparked debate regarding its virulence and transmissibility. This study contributes to this discussion by assessing its effect on the risk of latent tuberculosis infection (LTBI), active tuberculosis (TB) disease among contacts, and clustering of known TB cases. METHODS: We conducted a retrospective cohort study using the records of 4457 culture-confirmed TB patients and their contacts (20,448) reported to the Florida Department of Health between 2009 and 2023. Univariate and multivariate analyses were used to evaluate the effect of the Beijing strain on LTBI, active TB risk among contacts, and case clustering. RESULTS: Our study revealed no significant difference in transmissibility between the Beijing and non-Beijing genotypes among contacts. LTBI prevalence was 19.9%, slightly higher in non-Beijing than Beijing genotypes (20.2% vs. 15.5%, p < 0.001). The prevalence of active TB was 1.8%, with no significant difference between the Beijing and non-Beijing genotypes (1.4% vs. 1.8%, p = 0.296). Increased LTBI risk was associated with older age, male sex, Hispanic ethnicity, multidrug-resistant TB exposure, household exposure, and a longer exposure duration. Active TB risk was higher for males, HIV-positive individuals, and contacts with more prolonged exposure to index cases. The Beijing genotype was associated with increased TB case clustering (aOR = 1.98, 95%CI: 1.53, 2.55, p < 0.001) as compared to the non-Beijing genotypes. US birthplace (aOR = 2.75, 95%CI: 2.37, 3.19, p < 0.001), pulmonary disease (aOR = 1.27, 95%CI: 1.04, 1.56, p < 0.020), cavitary TB (aOR = 1.25, 95% CI: 1.08, 1.44, p < 0.003), previous year alcohol use (aOR = 1.68, 95%CI: 1.38, 2.04, p < 0.001), and recreational drug use (aOR = 1.32, 95%CI: 1.04, 1.67, p < 0.024) were also associated with an increased risk of TB case clustering. CONCLUSION: While the Beijing genotype did not increase the risk of LTBI or active TB among contacts, it showed a higher tendency for case clustering. Hence, interventions should prioritize populations where this genotype is prevalent.

The impact of China's urbanization on ecosystem service value from the perspective of gross ecosystem product: a case study of Beijing-Tianjin-Hebei region.

Gross ecosystem product (GEP) is an aggregate measure of the monetary value of final ecosystem services, or the direct benefits that people derive from nature. GEP can provide decision makers with clear and competing evidence of the monetary value of ecosystem services. However, the relationship between GEP and urbanization has not been clarified which is not conducive to the decision-making role of GEP in the process of urban sustainable development. This work focused on the 'Beijing-Tianjin-Hebei' (BTH) urban agglomeration as a case study of the dynamics of ecological production amidst rapid economic and urban development, and coupled a spatial-temporal analysis of regional ecological change based on GIS (Geographic Information System) with economic valuation methods using official statistics and survey data. Results showed that from 2000 to 2020, the GEP increased from 1.55 trillion to 2.36 trillion, the value of provisioning services and cultural services increased from 0.51 to 0.71 trillion to 0.10-0.65 trillion. The value of regulation services showed an upward and downward trend (0.94-1.03-0.98) due to the rapid economic development in the Beijing-Tianjin-Hebei region. There were obvious spatial differences in the distribution of the GEP, in which Beijing, Tianjin, Tangshan, Cangzhou GEP accounted for 15%, 14%, 16% and 11%, respectively. During 2000-2020, there is a significant correlation between urbanization index (UI) and GEP in BTH, but the correlation between GEP and UI shows a trend of first increasing and then decreasing. The correlation between UI and EPS and ERS gradually decreases, and the impact of UI on ETS shows a significant positive correlation. In the future, it can be foreseen that urbanization will suppress the increase of GEP.

Changes in climate attributes and harvest area structures jointly determined spatial-temporal variations in water footprint of maize in the Beijing-Tianjin-Hebei region.

Irrigation contributes significantly to boosting crop yield and ensuring food security. However, in the Beijing-Tianjin-Hebei (BTH) region, unsustainable irrigation practices have led to serious outcomes on freshwater resources. Balancing irrigation with crop productivity in this region, currently facing complex challenge, requires a comprehensive understanding of its spatial pattern and thus to seeking for potential optimization of current crop structures. In this study, we employed the concept of water footprint (WFP) to assess the spatial-temporal patterns of water footprint for maize in BTH region at the county level for the years 2005, 2010, 2015, and 2020, untangled the relative impacts on WFP from climate attributes and harvest area structures. Our results showed significant regional heterogeneities in both blue water requirement and green water requirement, ranging from 64.6 mm to 290.7 mm. Yearly anomalies of climate attributes and maize harvest jointly influenced water footprints, with the highest value of 1.06 × 1011 m3 occurring in the year 2015. The green water footprints, linked to precipitation, dominated the total water footprint compared to the blue water footprint associated with irrigation. Additionally, we observed an increasing influence of maize harvest area on the temporal changes in water footprints, with these changes becoming more concentrated in the east-central region over time. Our findings underscore the respective contributions of annual climate attribute changes and harvest area variations at the county level, highlighting regions where urgent interventions are required to enhance the sustainability of water usage for agriculture.

[Estimation of Near-surface Ozone Concentration in the Beijing-Tianjin-Hebei Region Based on XGBoost-LME Model].

High spatiotemporal resolution data on near-surface ozone concentration distribution is of great significance for monitoring and controlling atmospheric ozone pollution and improving the living environment. Using TROPOMI-L3 NO2, HCHO products, and ERA5-land high-resolution data as estimation variables, an XGBoost-LME model was constructed to estimate the near-surface ozone concentration in the Beijing-Tianjin-Hebei Region. The results showed that： ① Through correlation analysis, surface 2 m temperature （T2M）, 2 m dewpoint temperature （D2M）, surface solar radiation downwards （SSRD）, tropospheric formaldehyde （HCHO）, and tropospheric nitrogen dioxide （NO2） were important factors affecting the near-surface ozone concentration in the Beijing-Tianjin-Hebei Region. Among them, T2M, SSRD, and D2M had strong correlations, with correlation coefficients of 0.82, 0.75, and 0.71, respectively. ② Compared with that of other models, the XGBoost-LME model had the best performance in terms of various indicators. The ten-fold cross-validation evaluation indicators R2, MAE, and RMSE were 0.951, 9.27 µg·m-3, and 13.49 µg·m-3, respectively. At the same time, the model performed well at different time scales. ③ In terms of time, there was a significant seasonal difference in near-surface ozone concentration in the Beijing-Tianjin-Hebei Region in 2019, with the concentration changing in the order of summer > spring > autumn > winter. The monthly average ozone concentration in the region showed an inverted "V" trend, with a slight increase in September. The highest value occurred in July, whereas the lowest value occurred in December. In terms of spatial distribution, the near-surface ozone concentrations in the Beijing-Tianjin-Hebei Region during the months of February and March were generally at the same levels. In January, November, and December, there was a relatively insignificant trend of higher concentrations in the north and lower concentrations in the south. For the remaining months, the spatial distribution of near-surface ozone concentrations in this area predominantly exhibited a pattern of higher concentrations in the south and lower concentrations in the north. High-value areas were predominantly found in the plain regions of the southern part with lower altitudes, dense population, and higher industrial emissions； low-value areas, on the other hand, were primarily located in mountainous areas of the northern part with higher altitudes, sparse population, higher vegetation coverage, and lower industrial emissions.

[Occurrence and Distribution of Potential Dangerous Biological Agents in Beijing Suburban Rivers].

Dangerous biological agents （DBAs） refer to microorganisms, toxins, and other biological substances that have the potential to cause significant harm to humans, animals, plants, and the environment. They are the primary target of the prevention and response in China's Biosafety Law, and it is of great importance to clarify the characteristics of DBAs in the Beijing suburban rivers for the insurance of the water safety in Beijing. The typical Beijing suburban rivers （Mangniu River, Chaohe River, and Baihe River） were selected, and the occurrence and distribution of DBAs concerning the molecular biology composition as the nucleic acid （antibiotic resistance genes, ARGs）, nucleic acid and proteins （viruses）, and intact cellular structures （pathogens） were determined based on the metagenomics. The results showed that there was a high abundance of multidrug-resistant ARGs in the water and substrates of the urban river； on average, they made up 74.11% ±6.82% of the total, and the abundance of aminoglycoside and MLS （macrolide-lincosamide-streptomycin）-resistant ARGs was the highest, but the predominant subtypes of ARGs were of low risk and had limited transmission potential. The viruses in the tributary mainly belonged to the phages, most of which were Kyanoviridae and Peduoviridae, with averages of 16.98% ±8.44% and 16.19% ±10.79%, respectively. Eukaryotic viral populations consisted mainly of members from the Mimiviridae and Phycodnaviridae families, with averages of 10.37% ±12.68% and 8.34% ±6.97%, respectively, whereas there were few viruses related to human and animal diseases. The pathogenic bacteria mainly contained Neisseria meningitidis, Brucella suis, Salmonella enterica, and Burkholderia pseudomalle, with averages of 19.17% ±3.63%, 12.76% ±2.88%, 11.22% ±1.95%, and 8.26% ±1.84%, respectively. The composition and abundance of pathogenic bacteria varied significantly among different tributaries and locations, possibly owing to water quality, pollution sources, environmental factors, and human activities. These findings can provide data support for the water safety management and biological risk control of Beijing suburban rivers.

[Molecular markers of M. tuberculosis virulence in lung tissue (experimental study)]. / Molekulyarnye markery virulentnosti M. tuberculosis v tkani legkikh (eksperimental'noe issledovanie).

More than a quarter of the world's population is infected with Mycobacterium tuberculosis. However, only about 10% of those infected develop active TB. This indicates a key role for innate immunity in limiting M. tuberculosis replication. Most often, bacteria can regulate the expression of host-specific molecules and weaken host immunity. OBJECTIVE: To use a biological model, in order to determine significant molecular immunohistochemical markers characterizing the virulence of the "Buryat" and "Omsk" subtypes of the M. tuberculosis Beijing genotype in lung tissue. MATERIAL AND METHODS: Lung samples of the C57BL/6 male mice were obtained during experimental infection with M. tuberculosis strains: the reference laboratory strain H37Rv, multidrug-resistant clinical strains 396 (highly lethal and hypervirulent «Buryat¼ genotype Beijing 14717-15) and 6691 (low-lethal and low-virulent "Omsk" genotype Beijing 1071-32) on days 14, 21, 60 and 120. They were studied by histological and immunohistochemical methods. The relative areas of expression of IL-6, IL-12A, iNOS, and TNF-α in the lung tissue of model animals were established. RESULTS: A study of strain 396 showed that both disease progression and damage to lung tissue are associated with a highly reactive immune response and increased synthesis of iNOS and strain characteristics that block the production of TNF-α. On the contrary, for strain 6691 a low reactivity of the immune response was revealed, with statistically significantly lower values of the relative area of expression of NOS and TNF-α during all observation periods (days 14-120). All animals that survived to day 120 showed a similar morphological picture with differences in cytokine levels, indicating a nonlinear relationship between proinflammatory factors and the damage substratum. CONCLUSION: The progression of the disease and damage of lung tissue were associated with a highly reactive immune response and increased synthesis of iNOS, strain properties that block the TNF-α production. Thus, iNOS and TNF-α can act as molecular markers characterizing the virulence of the "Buryat" and "Omsk" subtypes of M. tuberculosis in lung tissue.

The Effects of Dust Storms on People Living in Beijing: A Qualitative Study.

Dust storms, which are common aversive occurrences in northern China, result from high winds, dry soil or dust, and soil surface disturbance. Exposure to dust storms, regardless of duration, can induce varying mental and physical distress levels. Recognizing the urgency of comprehending the impact of dust storms on residents and the scarcity of information on their effects on the indigenous civilians there, this study aims to address this gap by qualitatively sampling 29 participants from Beijing, a typical city in northern China. The current study seeks to gain insights into residents' dust storm experiences and explore their perspectives on effective coping mechanisms. The findings align with existing knowledge regarding the mental and physical repercussions of dust storms while identifying some emerging patterns of coping mechanisms already employed by residents in Beijing. Concerns regarding mental well-being, either directly influenced by the environmental conditions or indirectly stemming from disruptions to life routines on a broader scale, persistently dominate people's perceptions of dust storms. New themes emerged following the step-by-step exploration of feelings and coping mechanisms. This study aims to enlighten the public about the ramifications of the dust storms in Beijing and advocate for essential policy support.

Nutritional Knowledge, Attitudes, and Needs Among Community Residents of Beijing: A Cross Sectional Study.

Background: Community health education is essential in combating obesity and cardiovascular diseases by addressing nutritional knowledge gaps and promoting healthier dietary habits in China. The aim of this study was to investigate the nutritional knowledge, attitudes, and needs of residents at Beijing Fengtai District. Methods: This cross-sectional study was conducted between October 2021 and January 2022, residents from 31 communities of the Fengtai District were given an online questionnaire, which was designed to assess their nutritional knowledge, attitudes, and needs. Results: From 420 distributed surveys, a total of 416 participants were enrolled for an effective recovery rate of 99.05%. Among them, 317 participants (76.20%) scored 80% or higher on the nutritional knowledge questionnaire, participants with higher nutritional knowledge scores were more likely to be aged over 60 years (OR = 0.21, 95% CI 0.06-0.76, p = 0.02), female (OR = 0.40, 95% CI 0.22-0.73, p < 0.01) and employed (OR = 2.31, 95% CI 1.04-5.12, p = 0.04). While many community residents expressed a desire to receive guidance on dietary guidance (n = 303, 72.84%) dietary matching (n = 303, 72.84%), and preventive health care (n = 286, 68.75%). Residents were familiar with nutritional care clinics (55.05%) and believed that the nutritional care clinics should be increased (59.86%). In addition, 345 residents (83.41%) wanted nutritional care clinics to provide consultation on nutritious meal planning. Conclusion: Beijing residents need additional access to clinical nutritional resources as their needs are not fulfilled despite a relatively strong knowledge of nutrition.

An improved meteorological variables-based aerosol optical depth estimation method by combining a physical mechanism model with a two-stage model.

A two-stage model integrating a spatiotemporal linear mixed effect (STLME) and a geographic weight regression (GWR) model is proposed to improve the meteorological variables-based aerosol optical depth (AOD) retrieval method (Elterman retrieval model-ERM). The proposed model is referred to as the STG-ERM model. The STG-ERM model is applied over the Beijing-Tianjin-Hebei (BTH) region in China for the years 2019 and 2020. The results show that data coverage increased by 39.0% in 2019 and 40.5% in 2020. Cross-validation of the retrieval results versus multi-angle implementation of atmospheric correction (MAIAC) AOD shows the substantial improvement of the STG-ERM model over earlier meteorological models for AOD estimation, with a determination coefficient (R2) of daily AOD of 0.86, root mean squared prediction error (RMSE) and the relative prediction error (RPE) of 0.10 and 36.14% in 2019 and R2 of 0.86, RMSE of 0.12 and RPE of 37.86% in 2020. The fused annual mean AOD indicates strong spatial variation with high value in south plain and low value in northwestern mountainous areas of the BTH region. The overall spatial seasonal mean AOD ranges from 0.441 to 0.586, demonstrating strongly seasonal variation. The coverage of STG-ERM retrieved AOD, as determined in this exercise by leaving out part of the meteorological data, affects the accuracy of fused AOD. The coverage of the meteorological data has smaller impact on the fused AOD in the districts with low annual mean AOD of less than 0.35 than that in the districts with high annual mean AOD of greater than 0.6. If available, continuous daily meteorological data with high spatiotemporal resolution can improve the model performance and the accuracy of fused AOD. The STG-ERM model may serve as a valuable approach to provide data to fill gaps in satellite-retrieved AOD products.