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Background: In the "treat all" era, there are few data on the nature of HIV clinical progression in middle-income countries. The aim of the current study was to prospectively analyze the clinical progression of HIV and its indicators among men in China with acute HIV who have sex with men. Methods: From 2009–2014 a total of 400 men with acute HIV infection (AHI) were identified among 7,893 men who have sex with men via periodic pooled nucleic acid amplification testing, and they were assigned to an AHI prospective cohort in Beijing and Shenyang, China. Rapid progression was defined as two consecutive CD4+ T cell counts < 350/µL within 3–24 months post-infection. Kaplan−Meier and Cox-regression analyses were conducted to identify predictors of rapid progression. Results: Among 400 men with AHI 46.5% were rapid progressors, 35.1% reached rapid progressor status by 12 months post-infection, and 63.9% reached rapid progressor status by 24 months. Rapid progression was associated with herpes simplex-2 virus coinfection (adjusted hazard ratio [aHR] 1.7, 95% confidence interval [CI] 1.2–2.3], depression (aHR 1.9, 95% CI 1.5–2.6), baseline CD4+ T cell count < 500/μL (aHR 3.5, 95% CI 2.4–5.1), higher baseline HIV viral load (aHR 1.6, 95% CI 1.2–2.3), acute symptoms lasting ≥ 2 weeks (aHR 1.6, 95% CI 1.1–2.2), higher body mass index (aHR 0.9, 95% CI 0.9–1.0), higher HIV viral load (aHR 1.7, 95% CI 1.4–2.1), set point viral load at 3 months (aHR 2.0, 95% CI 1.6–2.5), each 100-cell/μL decrease in CD4+ T cell count at 3 months (aHR 2.2, 95% CI 1.9–2.5), and baseline routine blood tests including white blood cell count < 5.32, hemoglobin ≥ 151, mean corpuscular hemoglobin ≥ 30.5, hemoglobin concentration ≥ 342, mean platelet count ≥ 342, lymphocytes ≥ 1.98, and mixed cell count ≥ 0.4 (all p < 0.05). Conclusion: Almost half of the patients underwent rapid clinical progression within 2 years after HIV infection. A treat-all policy is necessary and should be strengthened globally. Rapid progression was correlated with herpes simplex-2 virus coinfection, depression, low CD4+ T cell counts, and high set point viral load in acute infection stage. Rapid progression can be identified via simple indicators such as body mass index and routine blood test parameters in low and middle-income countries. [ABSTRACT FROM AUTHOR]

The microbial load and community diversity on food processing environmental surfaces from a Chinese FVs-processing facility were investigated. [Display omitted] • High levels of microbial load were observed on most environmental surfaces. • Zone 1 environmental surfaces were dominated by Pseudomonas and Acinetobacter. • Sorting and DC treatments contributed < 20% of bacterial community in cutting areas. • Comamonas and Janthinobacterium showed synergistic interaction with other genera. Zoning is typically adopted by food manufacturers and classified into three different zones including Zone 1 (food contact surface), Zone 2 (proximity to food and food contact surfaces) and Zone 3 (remote surfaces from processing). In this study, environmental surfaces belonging to these three zones were sampled during food processing in a fresh-cut vegetables (FVs) processing facility located in Beijing, China. Bacterial loads in terms of aerobic plate count and coliform count were evaluated by culture-dependent techniques. The profile and diversity of bacterial community in these three zones were investigated by high-throughput sequencing. Zone 1 showed similar microbiota and predominated by Pseudomonas and Acinetobacter, while the predominant genera on Zone 2 or 3 were quite varied among different processing steps. The SourceTracker analysis showed that most of the bacteria (above 80%) on surfaces were from unknown sources, while sorting and disinfection & cleaning steps contributed equally to the bacterial community of cutting areas. Microbial association network analysis revealed strong positive interactions of Comamonas and Janthinobacterium with Myroides and Serratia , respectively, whereas Pseudomonas showed no significant correlation with other genera. The function of microbial communities was predicted based on BugBase 16S rRNA database, and the results indicated that the proportions of potential biofilm-forming bacteria were above 70% in all samples, and species of Pseudomonas , Comamonas , Chryseobacterium and Janthinobacterium were opportunistic pathogens or spoilage bacteria. This study evaluated the bacteria risks including bacterial load, composition, as well as potential bacterial interaction, function and microbial transfer on food processing surfaces, which will facilitate our better understanding on the cross-contaminations and preventions of harmful microorganism in FVs processing industry. [ABSTRACT FROM AUTHOR]

Tourists ' movement aroused the concern of researchers long ago, but more studies of tourists flows are concentrated on macro and meso scale based on second-hand statistical date while studies concerning about tourist behavior on individual spatial-temporal level are relatively few. Recently, tourist tracking technology based on LBS has developed rapidly, which could provide clients location service and produce lots of backstage data supplying researchers with tourists' behavior data. The paper, with biological rhythm and time geography as basic theory and study methods, studies tourists' process of activities, rhythm and regulation within spatial scale of scenic areas based on GPS survey data and daily survey data completed in Summer Palace, Beijing in December, 2010. GPS tracking data truly and accurately record the process of tourists ' activities, providing data basis for researchers to better understand and analyze tourists' rhythm of activities and regulation. The study results can provide theoretical guidance for the evaluation of tourists ' behavior quality, behavior modification, optimization and dynamic management of scenic spots. [ABSTRACT FROM AUTHOR]

Abstract: Beijing, the capital of China, is a rapidly developing mega-city with a huge population in the world. Beijing has been experiencing severe air pollution problems since 1980s due to more and more energy consumption. In the case of severe organic aerosol pollution in Beijing, a one-year-long observation on major organic compounds in PM2.5 was performed at an urban site to gain information of their ambient concentration levels and sources in Beijing. The compound classes identified by GC/MS included alkanes, PAHs, fatty acids, dicarboxylic acids, and hopanes, whose seasonal average concentrations during the year were 39–477, 9–283, 260–483, 16–42, and 2.3–16ngm−3, respectively. Since the molecular distributions of particulate organic matter are indicative of different emission sources, their seasonal characteristics and variations were discussed in detail to explore the major contributing sources in Beijing. Conclusively, organic aerosol pollution in Beijing was found to be mostly associated with vehicle exhaust, coal combustion for residential heating, and cooking emissions, and the latter two sources are unique Chinese pollution sources. The dataset in this paper provides useful information for establishing effective control measures to reduce organic aerosol pollution in Beijing. [Copyright &y& Elsevier]

Oxygenated volatile organic compounds (OVOCs) are critical precursors of atmospheric ozone (O 3) and secondary organic aerosols (SOA). Although China is experiencing increasing O 3 pollution from north to south, understanding the major sources of OVOCs in this region is still limited due to their active photochemical behaviors. In this study, five critical OVOCs at a northern urban site (Beijing) and a southern urban site (Shenzhen) were monitored in summer using proton transfer reaction-mass spectrometry (PTR-MS). The mean total concentration of VOCs measured in Beijing (39.4 ppb) was much higher than that measured in Shenzhen (16.7 ppb), with methanol and formaldehyde being the most abundant in concentration at both sites. The source apportionment of daytime OVOCs was conducted effectively using a photochemical age-based parameterization method. Biogenic and anthropogenic secondary sources were the main sources of formaldehyde, acetaldehyde, and acetone at both sites, with a total contribution of 46–82%; acetone also had a large regional-scale background contribution (36–38%); methanol and methyl ethyl ketone (MEK) were mainly derived from anthropogenic primary sources (35–55%) at both sites. In addition, the regional background levels of OVOCs measured in North China were shown to be much higher than those measured in South China. The calculation of the total O 3 formation potential (OFP) of OVOCs highlights the comparable contributions from anthropogenic and biogenic sources in both Beijing and Shenzhen, indicating the important role of biogenic OVOC sources even in polluted environments. Since biogenic sources are already important but uncontrollable, anthropogenic emissions in China need to be restricted even more critically in the future. Image 1 • Oxygenated VOCs in urban air are much higher in northern than in southern China. • Biogenic and anthropogenic secondary sources are the main sources of aldehydes. • Biogenic sources largely influence ozone formation through oxygenated VOCs. Oxygenated volatile organic compounds have comparable contributions from biogenic and anthropogenic sources in terms of O 3 formation potential. [ABSTRACT FROM AUTHOR]

Abstract: Beijing is a rapidly developing city with severe and unique air pollution problems. Organic matter is the most abundant fraction in fine particles in Beijing, occupying 30–50% of the total mass, indicating its key role in air pollution control. However, detailed chemical characterization of particulate organic matter in Beijing has never been reported. In this study, fine particles in the urban atmosphere in Beijing were investigated for its organic components by GC/MS technique. Over 100 individual organic compounds were identified and quantified in 25 PM2.5 samples from the summer, autumn and winter of 2002–2003. Alkanes, fatty acids, dicarboxylic acids, polycyclic aromatic hydrocarbons and some important tracer compounds (hopanes, levoglucosan and steroids) were the major constituents with the sum of their concentrations of 502, 1471 and 1403 ng m−3 in summer, autumn and winter, respectively. Different organic compounds presented apparently different seasonal characteristics, reflecting their different dominant emission sources, such as coal combustion, biomass burning and cooking emission. The abundance and origin of these organic compounds are discussed to reveal seasonal air pollution characteristics of Beijing. [Copyright &y& Elsevier]

An accurate regional estimate of soil moisture content (SMC) is important for water management and drought monitoring. Traditional ground measurement methods of SMC are limited by the disadvantages of high cost and small scale. The development of remote sensing (RS) technology provides a cost-effective tool for estimating SMC at regional scale. However, the estimation of SMC by using the combination of multiple sensors has yet to be thoroughly discussed. Furthermore, the way in which vegetation types, fraction of vegetation coverage (FVC) and soil layer depth affect the SMC-estimation performance remains unclear. Therefore, the objectives in this study are to (1) evaluate the SMC-estimation performance provided by Landsat-8 data and random forest regression (RFR) algorithm; (2) discuss the accuracy of RS-based method for SMC estimation at different soil layer depths, and (3) explore how vegetation types and FVC affect the performance of SMC-estimation. The results can be summarized as: (1) the SMC estimation performance of multispectral (MS)- and thermal infrared (TIR)-based indices single used were comparable, in which TIR-based indices performed better in shallow soil layer while MS-based indices performed better in deep soil layer. Generally, MS- and TIR-based indices jointly used outperformed the index single used. (2) the accuracy of the proposed method for estimating SMC decreased with soil depth. (3) the proposed method performed greatest in grassland with relatively low height among the three vegetation types. Moreover, the SMC estimation in moderate vegetation coverage (FVC ranged from 0.3 to 0.5) was best. These results indicate that RS-based multimodal data combined with RFR could provide relatively repeatable and accurate SMC estimation. This approach can thus be used for the regional SMC monitoring and water resources management. [Display omitted] • A low-cost remote sensing method for regional-scale soil moisture monitoring was developed. • Multimodal data fusion showed effectiveness in field soil moisture estimation. • Random forest regression provided promising results in soil moisture estimation across soil depth and vegetation types. • Modest canopy coverage is more conducive to soil moisture monitoring. [ABSTRACT FROM AUTHOR]

• A monthly-scale pixel-based CCD model is developed. • The CCD between SAI and REE in Beijing is investigated. • Spatiotemporal distribution and changing trend of CCD are discussed in detail. • A schematic model on urban spatial dynamic CCD interactions is further built. Urbanization demands finer coordinated development of the urban human-earth relationship with high quality. Although a large number of studies have explored the long-term and large-scale coupling effect of urbanization and eco-environment, there is a lack of finer spatiotemporal method and assessment. Therefore, this paper proposes a monthly-scale pixel-based coupling coordination degree (CCD) model, aiming to explore the relationship between urban socioeconomic activity intensity (SAI) and regional eco-environment (REE) in Beijing during the period of January 2018 to May 2020 based on nighttime light data and MODIS images. The results show that the SAI in Beijing has shown a trend of increasing, and the overall REE was relatively stable during the investigated period. The CCD between SAI and REE in Beijing has been improving both spatially and quantitatively. Until May 2020, more than 50% of the human activity areas were in a state of high-level coordinated, and the mean CCD reached a basic-coordinated level. A schematic model is further built to explain the characteristics and process of coupling coordinated interactions between socioeconomic activity and eco-environment. The inner-annual micro-scale analysis and assessment provide theoretical support for fine-scale monitoring and high-quality urban development planning and policies from decision-makers. [ABSTRACT FROM AUTHOR]