Publications by authors named "Qingjun Guo"

Fungal communities play a vital role in composting by transforming organic waste into eco-friendly products. However, little is known about how their functional traits relate to the dissolved organic matter (DOM) transformation and humification. This study investigated the fungal taxonomic and functional groups succession during co-composting of green waste and sewage sludge under five raw material ratios ranging from 1:1 to 1:3, comparing their associations with DOM transformation.

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Introduction: The human brain processes 83% of information visually and 11% auditorily, with visual perception dominating multisensory integration. While audiovisual congruence enhances cognitive performance, the impact of audiovisual incongruence on working memory (WM) remains controversial. This study investigated how audiovisual incongruence affects WM performance under varying cognitive loads.

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PM oxidative potential (OP), a key driver of health risks, was investigated in Ningbo, China, using dual dithiothreitol (DTT) and ascorbic acid (AA) assays combined with machine learning (ML). This approach accounts for the complexity of interactions among key chemical drivers and accurately identifies chemical species and PM sources associated with OP - a critical gap in prior studies relying solely on correlation analysis and linear regression. Year-long PM samples revealed higher nighttime and summer OP (volume-based OP-DTTv and OP-AAv), linked to aerosol acidity and photochemical aging.

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Isotopic tracing has been widely used to identify the sources and migration processes of Zn in diverse environments. However, Zn isotope fractionation during the migration process within the mining area poses challenges to the accuracy of isotopic tracing. To address this issue, a representative Pb-Zn mining area in the karst region of southwestern China was selected as the study area, given its long-term tailings' pollution history and the extensive spatial distribution of Zn migration.

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Background: Obesity is a chronic metabolic disease, mainly caused by excessive/abnormal fat accumulation, as well as accompanied by endotoxemia and chronic inflammation. Quercetin, a natural flavonoid, may alleviate obesity by regulating gut microbiota and metabolites, but its exact mechanism for improving obesity is unknown.

Objectives: The aim of this study was to investigate the effects of quercetin on high-fat diet (HFD)-induced obesity in mice.

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Background: A complex interplay exists between anxiety and sleep quality. However, there is a scarcity of network analysis studies examining this relationship, particularly among college students. Previous research has relied on sum scores from scales, which fails to capture the nuanced, symptom-level associations between anxiety and sleep quality.

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The problem of secure output regulation (SOR) is solved from the passivity viewpoint for the networked switched system (NSS) permitting severely unstable dynamics in the presence of deception attacks (DAs). Dual Double-layer event-triggered policies (DLETPs) are developed to govern the appropriate triggering in a layered manner in conjunction with parameters of passivity, DAs, and switching characteristics. A tolerant switching strategy (TSS) is proposed to permit destabilizing switching outnumbers stabilizing switching and capture the passivity parameter.

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Phytoremediation efficiency can be enhanced by regulating rhizosphere processes, and the Cd isotope is a useful approach for deciphering Cd transport processes in soil-plant systems. However, the effects of adsorption and complexation on Cd isotope fractionation during the rhizosphere processes remain unclear. Here, we cultivated the Cd hyperaccumulator and Cd-tolerance in three different soils with citric acid applied as a degradable rhizosphere biostimulant.

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Zn isotope can help to clarify the migration, transformation and source contribution of Zn in farmland soil. However, the research on Zn isotope value of different end members in farmland soil is incomprehensive, and the variation of Zn isotope in farmland soil caused by different factors in different polluted areas is unclear, which hinders the usage of Zn isotope tracing method in farmland soil. Thus, a Pb-Zn mine polluted farmland in southwest China was selected as the research object and the end elements and farmland soil samples with different Zn contamination were systematically collected to analyse Zn content, fraction and isotopic composition.

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Lead (Pb) pollution in sediments remains a major concern for ecosystem quality due to the robust interaction at the sediment/water interface, particularly in shallow lakes. However, understanding the mechanism behind seasonal fluctuations in Pb mobility in these sediments is lacking. Here, the seasonal variability of Pb concentration and isotopic ratio were investigated in the uppermost sediments of a shallow eutrophic drinking lake located in southeast China.

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Rationale: Sulfur isotopes have been widely used to solve some key scientific questions, especially in the last two decades with advanced instruments and analytical schemes. Different sulfur speciation and multiple isotopes analyzed in laboratories worldwide and in situ microanalysis have also been reported in many articles. However, methods of sampling to measurements are multifarious, and occasionally some inaccuracies are present in published papers.

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Different scenarios of urban expansion can influence the dynamic characteristics of catchments in terms of phosphorus (P). It is important to identify the changes in P sources that occur during the process of urbanization to develop targeted policies for managing P in catchments. However, there is a knowledge gap in quantifying the variations of potential P sources associated with urbanization.

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The mechanism of sulfate formation during winter haze events in North China remains largely elusive. In this study, the multiple sulfur isotopic composition of sulfate in different grain-size aerosol fractions collected seasonally from sampling sites in rural, suburban, urban, industrial, and coastal areas of North China are used to constrain the mechanism of SO oxidation at different levels of air pollution. The ΔS values of sulfate in aerosols show an obvious seasonal variation, except for those samples collected in the rural area.

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Assessing flux and primary sources of the atmospheric nitrogen (N) deposition with high spatial resolution remained challenging. The epilithic moss is considered a suitable biological monitor to explore N deposition. Our study presented a detailed analysis of flux and major source contributions of ammonium (NH) and nitrate (NO) deposition using N and δN signatures of epilithic moss collected densely from the Yangtze River basin.

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Numerous studies have extensively examined the risk of lung cancer associated with polycyclic aromatic hydrocarbons (PAHs), with particular emphasis on the 16 priority PAHs. However, this may underestimate the actual risk. This study seeks to enhance the current risk assessment framework by integrating four additional parent PAHs such as Dibenzo[a,h]pyrene, Dibenzo[a,l]pyrene, Dibenzo[a,e]pyrene, 7H-benzo[c]fluorene with potentially high risk of causing cancer.

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Legacy phosphorus (P) in watersheds continuously affects the water quality. The time lag between anthropogenic P input and algal bloom has made P dynamics prediction in aquatic ecosystems more challenging. Whether the legacy P in the Yangtze River Watershed (YRW) exceeds its storage threshold remains unknown, and the continuous impact of legacy P on the water quality has not been analyzed.

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Excessive phosphorus (P) loadings cause major pollution concerns in large catchments. Quantifying the point and nonpoint P sources of large catchments is essential for catchment P management. Although phosphate oxygen isotopes (δO) can reveal P sources and P cycling in catchments, quantifying multiple P sources in a whole catchment should be a research focus.

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Particulate matter (PM) inhaled into human lungs causes oxidative stress and adverse health effects through antioxidant depletion (oxidative potential, OP). However, there is limited knowledge regarding the association between the lung-deposited dose (LDD) of PM and OP in extrathoracic (ET), tracheobronchial (TB), and pulmonary (P) regions of human lungs. Dithiothreitol (DTT) and ascorbic acid (AA) assays were employed to measure the OP of PM size fractions to investigate OP distribution in human lungs and identify the chemical drivers.

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The massive exploration and random dumping of coals in various regions of China create serious environmental and health problems because of the presence of toxic trace elements (TTEs), which possibly transfer to environment and cause serious health issues. This study was conducted to probe the environmental consequences of coalmines on the aquifer water and their association with health risks and the environment. For this purpose, 100 s of water samples was collected from the typical coalmine regions of Hancheng, Huanglong, Binxian, Handan, Langao, and Fusui and analyzed for various parameters.

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Elevated lead (Pb) has been widely observed in mangrove sediments due to human activities, yet understanding the sources of Pb in these sediments and the factors influencing Pb accumulation is challenging. Here, we combined Pb isotopes with partial extraction methods to study Pb contamination levels in mangrove sediments from the eastern and western parts of the Maowei Sea, China. Our results showed that the Pb in the leachate and residual fraction was mainly from anthropogenic and natural sources, respectively.

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Mangrove sediments act as both sinks and secondary sources for lead (Pb), yet the sources, migration, and transformations of Pb in mangrove environments are poorly understood. In this study, Pb concentration in three mangrove sediments adjacent to different land-use types was evaluated. The Pb sources were quantitatively identified using Pb isotopes.

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Long-term series data can provide a glimpse of the influence of natural and anthropogenic factors on water chemistry. However, few studies have been conducted to analyze the driving forces of the chemistry of large rivers based on long-term data. This study aimed to analyze the variations and driving mechanisms of riverine chemistry from 1999 to 2019.

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REEs are emerging contaminants, and soils nearby coal and coal ash with high REEs composition are vulnerable to REEs contamination. Besides, coal industry can alter surrounding soil characteristics. However, there is information paucity about REEs contamination and geochemical behaviors along with soil characteristics around coal industrial areas, which are essential for understanding their toxicity and mobilization.

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Worldwide mining activities produce vast quantities of mine tailings, which pose a threat to soil quality, crop yields, and the regional environment in the adjacent agricultural soil, but little is known about the impact of mining activities on the SOM source and migration. In this study, soil samples of the topsoil (0-15 cm) and soil profiles (0-50 cm), as well as the potential sources samples (C3 plants, C4 plants and mining tailings) were collected from mine-contaminated karst farmland of four different pollution levels (NP, non-polluted; SP, slightly polluted; MP, moderately polluted; and HP, heavily polluted). Total organic carbon (TOC), total organic nitrogen (TON), and stable isotopic compositions (δC and δN) of soil and potential sources samples were determined.

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