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Результаты 261-270 из 7,200
Opposite impact of DOM on ROS generation and photoaging of aromatic and aliphatic nano- and micro-plastic particles Полный текст
2022
Cao, Runzi | Liu, Xinna | Duan, Jiajun | Gao, Bowen | He, Xiaosong | Nanthi Bolan, | Li, Yang
Dissolved organic matter (DOM) plays a significant role in the photochemical behavior of nano- and micro-plastic particles (NPs/MPs). We investigated the influence of DOM on the mechanism on the photoaging of NPs/MPs with different molecular structures under UV₃₆₅ irradiation in water. DOM components used in this study are mainly humic acid and fulvic acid. The results showed that DOM promoted the weathering of aliphatic NPs/MPs (polypropylene (PP)), but inhibited or had only a minor effect on the photoaging of aromatic NPs/MPs (polystyrene (PS) NPs/MPs, carboxyl-modified PS NPs, amino-modified PS NPs, and polycarbonate MPs). NPs with a large surface area may adsorb sufficient DOM on the particle surfaces through π-π interactions, which competes with NPs for photon absorption sites, thus, can delay the photoaging of PS NPs. Aromatic MPs may release phenolic compounds that quench •OH, thereby weakening the photoaging process. For aliphatic MPs, the detection of peracid, aldehyde, and ketone groups on the polymer surface indicated that DOM promoted weathering of PP MPs, which was primarily because the generation of •OH due to DOM photolysis may attack the polymer by C–C bond cleavage and hydrogen extraction reactions. This study provides insight into the UV irradiation weathering process of NPs/MPs of various compositions and structures, which are globally distributed in water.
Показать больше [+] Меньше [-]Seasonal variation of dissolved bioaccessibility for potentially toxic elements in size-resolved PM: Impacts of bioaccessibility on inhalable risk and uncertainty Полный текст
2022
Jia, Bin | Tian, Yingze | Dai, Yuqing | Chen, Rui | Zhao, Peng | Chu, Jingjing | Feng, Xin | Feng, Yinchang
The health effects of potentially toxic elements (PTEs) in airborne particulate matter (PM) are strongly dependent on their size distribution and dissolution. This study examined PTEs within nine distinct sizes of PM in a Chinese megacity, with a focus on their deposited and dissolved bioaccessibility in the human pulmonary region. A Multiple Path Particle Dosimetry (MPPD) model was used to estimate the deposited bioaccessibility, and an in-vitro experiment with simulated lung fluid was conducted for dissolved bioaccessibility. During the non-heating season, the dissolved bioaccessible fraction (DBF) of As, Cd, Co, Cr, Mn, Pb and V were greater in fine PM (aerodynamics less than 2.1 μm) than in coarse PM (aerodynamics between 2.1 and 10 μm), and vice versa for Ni. With the increased demand of heating, the DBF of Pb and As decreased in fine particle sizes, probably due to the presence of oxide/silicate compounds from coal combustion. Inhalation health risks based on the bioaccessible concentrations of PTEs displayed the peaks in <0.43 μm and 2.1–3.3 μm particulate sizes. The non-cancer risk was at an acceptable level (95th percentiles of hazard index (HI) was 0.49), but the cancer risk exceeded the threshold value (95th percentiles of total incremental lifetime cancer risk (TCR) was 8.91 × 10⁻⁵). Based on the results of uncertainty analysis, except for the exposure frequency, the total concentrations and DBF of As and Cr in <0.43 μm particle size segment have a greater influence on the uncertainty of probabilistic risk.
Показать больше [+] Меньше [-]PM2.5 induces the distant metastasis of lung adenocarcinoma via promoting the stem cell properties of cancer cells Полный текст
2022
Pan, Junyi | Xue, Yueguang | Li, Shilin | Wang, Liuxiang | Mei, Jie | Ni, Dongqi | Jiang, Jipeng | Zhang, Meng | Yi, Shaoqiong | Zhang, Rong | Ma, Yongfu | Liu, Yang | Liu, Ying
Lung cancer is the most common cancer in China and second worldwide, of which the incidence of lung adenocarcinoma is rising. As an independent factor, air pollution has drawn the attention of the public. An increasing body of studies has focused on the effect of PM₂.₅ on lung adenocarcinoma; however, the mechanism remains unclear. We collected the PM₂.₅ in two megacities, Beijing (BPM) and Shijiazhuang (SPM), located in the capital of China, and compared the different components and sources of PM₂.₅ in the two cities. Vehicle emissions are the primary sources of BPM, whereas SPM is industrial emissions. We found that chronic exposure to PM₂.₅ promotes the tumorigenesis and metastasis of lung adenocarcinoma in patient-derived xenograft (PDX) models, as well as the migration and invasion of lung adenocarcinoma cell lines. SPM has more severe effects in vivo and in vitro. The underlying mechanisms are related to the stem cell properties of cancer cells, the epithelial-mesenchymal transition (EMT) process, and the corresponding miRNAs. It is hopeful to provide a theoretical basis for improving air pollution in China, especially in the capital area, and is of the significance of long-term survival of lung cancer patients.
Показать больше [+] Меньше [-]A miniaturized electrothermal array for rapid analysis of temperature preference behaviors in ecology and ecotoxicology Полный текст
2022
Henry, Jason | Bai, Yutao | Kreuder, Florian | Saaristo, Minna | Kaslin, Jan | Wlodkowic, Donald
Due to technical limitations, there have been minimal studies performed on thermal preferences and thermotactic behaviors of aquatic ectotherm species commonly used in ecotoxicity testing. In this work, we demonstrate an innovative, purpose-built and miniaturized electrothermal array for rapid thermal preference behavioral tests. We applied the novel platform to define thermal preferences in multiple invertebrate and vertebrate species. Specifically, Dugesia notogaea (freshwater planarians), Chironomus tepperi (nonbiting midge larvae), Ostracoda (seed shrimp), Artemia franciscana (brine shrimp), Daphnia carinata (water flea), Austrochiltonia subtenuis (freshwater amphipod), Physa acuta (freshwater snail), Potamopyrgus antipodarum (New Zealand mud snail) and larval stage of Danio rerio (zebrafish) were tested. The Australian freshwater water fleas, amphipods, snail Physa acuta as well as zebrafish exhibited the most consistent preference to cool zones and clear avoidance of zones >27 °C out of nine species tested. Our results indicate the larval stage of zebrafish as the most responsive species highly suitable for prospective development of multidimensional behavioral test batteries. We also showcase preliminary data that environmentally relevant concentrations of pharmaceutical pollutants such as non-steroidal anti-inflammatory drug (NSAID) ibuprofen (9800 ng/L) and insecticide imidacloprid (4600 ng/L) but not anti-depressant venlafaxine (2200 ng/L) and (iv) anticonvulsant medications gabapentin (400 ng/L) can perturb thermal preference behavior of larval zebrafish. Collectively our results demonstrate the utility of simple and inexpensive thermoelectric technology in rapid exploration of thermal preference in diverse species of aquatic animals. We postulate that more broadly such technologies can also have added value in ecotoxicity testing of emerging contaminants.
Показать больше [+] Меньше [-]Dispersion of airborne mercury species emitted from the cement plant Полный текст
2022
Nair, Sreekanth Vijayakumaran | Kotnik, Jože | Gačnik, Jan | Živković, Igor | Koenig, Alkuin Maximilian | Mlakar, Tanja Ljubič | Horvat, Milena
The cement industry is the second largest source of anthropogenic mercury (Hg) emissions in Europe, accounting for 11% of global anthropogenic Hg emissions. The main objective of this study was to examine the influence of Hg emissions from the Salonit Anhovo cement plant on Hg levels measured in the ambient air at Vodarna, 1 km downwind from the flue gas chimney. The findings reveal that the plant raw mill operational status plays an important role in Hg concentrations in the flue gas emitted from the plant. Emitted total gaseous mercury was, on average, higher (49.4 μg/m³) when raw mills were in the direct mode (both raw mills-off) and lower (23.4 μg/m³) in the combined mode (both raw mills-on). The average Hg concentrations in Vodarna were 3.14 ng/m³ for gaseous elemental mercury, 53.7 pg/m³ for gaseous oxidised mercury, and 41.9 pg/m³ for particulate bound mercury for the whole measurement period. Atmospheric Hg speciation in Vodarna, coupled with plant emissions and wind data, has revealed that the total gaseous mercury emitted from the cement plant is clearly related to all Hg species measured in Vodarna. Wind blowing from the northeastern quadrant (mostly NE, ENE) is responsible for the elevated Hg levels in Vodarna, where gaseous oxidised mercury levels are highly linked to the cement plant emissions. However, elevated levels of Hg species in the absence of northeastern winds indicate potential inputs from other unknown local sources as well as inputs from regional and global transport mechanisms.
Показать больше [+] Меньше [-]Frequent algal blooms dramatically increase methane while decrease carbon dioxide in a shallow lake bay Полный текст
2022
Zhang, Lei | He, Kai | Wang, Tong | Liu, Cheng | An, Yanfei | Zhong, Jicheng
Freshwater ecosystems play a key role in global greenhouse gas estimations and carbon budgets, and algal blooms are widespread owing to intensified anthropological activities. However, little is known about greenhouse gas dynamics in freshwater experiencing frequent algal blooms. Therefore, to explore the spatial and temporal variations in methane (CH₄) and carbon dioxide (CO₂), seasonal field investigations were performed in the Northwest Bay of Lake Chaohu (China), where there are frequent algal blooms. From the highest site in the nearshore to the pelagic zones, the CH₄ concentration in water decreased by at least 80%, and this dynamic was most obvious in warm seasons when algal blooms occurred. CH₄ was 2–3 orders of magnitude higher than the saturated concentration, with the highest in spring, which makes this bay a constant source of CH₄. However, unlike CH₄, CO₂ did not change substantially, and river mouths acted as hotspots for CO₂ in most situations. The highest CO₂ concentration appeared in winter and was saturated, whereas at other times, CO₂ was unsaturated and acted as a sink. The intensive photosynthesis of rich algae decreased the CO₂ in the water and increased dissolved oxygen and pH. The increase in CH₄ in the bay was attributed to the mineralization of autochthonous organic carbon. These findings suggest that frequent algal blooms will greatly absorb more CO₂ from atmosphere and increasingly release CH₄, therefore, the contribution of the bay to the lake's CH₄ emissions and carbon budget will be major even though it is small. The results of this study will be the same to other shallow lakes with frequent algal bloom, making lakes a more important part of the carbon budget and greenhouse gases emission.
Показать больше [+] Меньше [-]Ignored effects of phosphite (P+III) on the growth responses of three typical algae species Полный текст
2022
Han, Chao | Ren, Jinghua | Wang, Baoying | Wang, Zhaode | Yin, Hongbin | Ke, Fan | Xu, Di | Zhang, Lei | Si, Xiaoxia | Shen, Qiushi
Nowadays, the ubiquitous distribution and increasing abundance of P⁺ᴵᴵᴵ in waterbodies have caused serious concerns regarding its bioavailability and potential toxicity. However, our knowledge on these issues is relatively limited. We addressed previously unknown effects of P⁺ᴵᴵᴵ on three dominate algae species i.e. Microcystic aeruginosa (M. aeruginosa), Chlorella pyrenoidesa (C. pyrenoidesa) and Cyclotella. sp in eutrophic waterbodies in China. Remarkable declines in biomass, specific growth rate and Chl-a of algae cells treated with 0.01–0.7 mg/L P⁺ᴵᴵᴵ as sole or an alternative P source were observed, indicating P⁺ᴵᴵᴵ had an inhibitory effect on the algal growth. Besides, the intracellular enzyme activities e.g superoxide dismutase (SOD) and malondialdehyde (MDA) were significantly increased with P⁺ᴵᴵᴵ stress. M. aeruginosa and Cyclotella. sp cells seemed to be more sensitive to P⁺ᴵᴵᴵ toxicity than C. pyrenoidesa since cell membrane suffered more serious stress and destruction. These findings combined, it confirmed P⁺ᴵᴵᴵ could not be utilized as bioavailable P, but had certain toxicity to the tested algae. It indicated that the increased P⁺ᴵᴵᴵ abundance in eutrophic waterbodies would accelerate the algal cell death, which could have a positive effect against algal blooms. Our results provide new insights into assessing the ecological risks of P⁺ᴵᴵᴵ in aquatic environments.
Показать больше [+] Меньше [-]Screening and validation of biomarkers for cadmium-induced liver injury based on targeted bile acid metabolomics Полный текст
2022
Tian, Meng | Yan, Jun | Zhang, Honglong | Wei, Yuhui | Zhang, Mingtong | Rao, Zhi | Zhang, Mingkang | Wang, Haiping | Wang, Yanping | Li, Xun
Although cadmium (Cd) is a toxic heavy metal that reportedly causes liver injury, few studies have investigated biomarkers of Cd-induced liver injury. The purpose of this study is to investigate the role of bile acid (BA) in Cd-induced liver injury and determine reliable and sensitive biochemical parameters for the diagnosis of Cd-induced liver injury. In this study, 48 Sprague-Dawley rats were randomly divided into six groups and administered either normal saline or 2.5, 5, 10, 20, and 40 mg/kg/d cadmium chloride for 12 weeks. A total of 403 subjects living in either a control area (n = 135) or Cd polluted area (n = 268) of Dongdagou-Xinglong (DDGXL) cohort were included, a population with long-term low Cd exposure. The BA profiles in rats' liver, serum, caecal contents, faeces, and subjects' serum were detected using high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS). Changes in rats' and subjects' liver injury indices, rats' liver pathological degeneration, and rats' liver and subjects’ blood Cd levels were also measured. Cadmium exposure caused cholestasis and an increase in toxic BAs, leading to liver injury in rats. Among them, glycoursodeoxycholic acid (GUDCA), glycolithocholic acid (GLCA), taurolithocholic acid (TLCA), and taurodeoxycholate acid (TDCA) are expected to be potential biomarkers for the early detect of Cd-induced liver injury. Serum BAs can be used to assess Cd-induced liver injury as a simple, feasible, and suitable method in rats. Serum GUDCA, GLCA, TDCA, and TLCA were verified to be of value to evaluate Cd-induced liver injury and Cd exposure in humans. These findings provided evidence for screening and validation of additional biomarkers for Cd-induced liver injury based on targeted BA metabolomics.
Показать больше [+] Меньше [-]Appraising regional anthropogenic heat flux using high spatial resolution NTL and POI data: A case study in the Beijing-Tianjin-Hebei region, China Полный текст
2022
Wang, Yichen | Hu, Deyong | Yu, Chen | Di, Yufei | Wang, Shasha | Liu, Manqing
Rapid urbanization and the aggregation of human activities in cities have resulted in large amounts of anthropogenic heat (AH) emission, which affects urban climate. Quantifying and assessing the AH emission values accurately and analyzing their spatial distribution characteristics is important to understand the energy exchange processes of urban areas. In this study, the high spatial resolution anthropogenic heat flux (AHF) quantification and spatial distribution analysis were conducted using multi-source data in the Beijing-Tianjin-Hebei region (BTH region) of China. First, the AH emission in district and city level were estimated using inventory method based on energy consumption and socio-economic statistical data; Then, AHF spatial quantification models were constructed based on high spatial resolution nighttime light (NTL) data and Point of interests (POI) data, and 130 m × 130 m gridded AHF quantification result in BTH region was realized; Finally, the potential numerical and spatial distribution patterns of AHF were analyzed using various indicators including contribution rate and aggregation index. The results show that: (1) The parameterized index constructed based on NTL and POI data shows a strong correlation with AHF, with R² ranging from 0.79 to 0.94 and a mean absolute error (MAE) value of 0.72 w·m⁻², which can be applied to the quantification of gridded AHF values with high resolution. The highest total AHF in the study area is 214 w·m⁻², and the average value is 2.24 w·m⁻². (2) Considering the sources of AHF, industrial emission sources in BTH region contribute the most to the total AHF, but commercial building emission sources in Beijing have a higher contribution, which can reach 33.8%. (3) Different types of AHF have different spatial aggregation levels. Commercial building emission and human metabolic emission have the highest aggregation level, and transportation emission has the lowest aggregation level.
Показать больше [+] Меньше [-]Fine particulate matter, airway inflammation, stress response, non-specific immune function and buccal microbial diversity in young adults Полный текст
2022
Lin, Zhijing | Chen, Ping | Yuan, Zhi | Yang, Liyan | Miao, Lin | Wang, Hua | Xu, Dexiang
Fine particulate matter (PM₂.₅) has been associated with risk of oral and respiratory diseases. However, the biological mechanisms of adverse oral and respiratory health response to PM₂.₅ fluctuation have not been well characterized. This study aims to explore the relationships of PM₂.₅ with airway inflammation, salivary biomarkers and buccal mucosa microbiota. We performed a panel study among 40 college students involving 4 follow-ups from August to October 2021 in Hefei, Anhui Province, China. Health outcomes included fractional exhaled nitric oxide (FeNO), salivary biomarkers [C-reactive protein (CRP), cortisol, lysozyme and alpha-amylase] and buccal mucosa microbial diversity. Linear mixed-effect models were applied to explore the cumulative impacts of PM₂.₅ on health indicators. PM₂.₅ was positively correlated with FeNO, CRP, cortisol and alpha-amylase, while negatively with lysozyme. Per 10-μg/m³ increase in PM₂.₅ was linked to maximum increments in FeNO of 10.71% (95%CI: 2.01%, 19.41%) at lag 0–24 h, in CRP of 7.10% (95%CI: 5.39%, 8.81%) at lag 0–24 h, in cortisol of 1.25% (95%CI: 0.44%, 2.07%) at lag 0–48 h, and in alpha-amylase of 2.12% (95%CI: 0.53%, 3.71%) at lag 0–24 h, while associated with maximum decrement in lysozyme of 0.53% (95%CI: 0.12%, 0.95%) at lag 0–72 h. Increased PM₂.₅ was linked to reduction in the richness and evenness of buccal microbe and o_Bacillales and o_Bacteroidales were identified as differential microbes after PM₂.₅ inhalation. Bio-information analysis indicated that immunity system pathway was the most important enriched abundant process altered by PM₂.₅ exposure. In summary, short-term PM₂.₅ exposure may impair oral and respiratory health by inducing inflammatory and stress responses, weakening immune function and altering buccal mucosa microbial diversity.
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