Erianin inhibits the progression of pancreatic cancer by directly targeting AKT and ASK1.

BACKGROUND: Pancreatic cancer is a malignant tumor of the digestive tract with a high mortality rate. Erianin has antitumor activity, but the regulatory targets and mechanism of action in pancreatic cancer are unclear. The objective of this study was to evaluate the anti-pancreatic cancer activity of Erianin and explore its underlying mechanisms. METHODS: A network pharmacology approach was used to investigate the mechanism of action of Erianin in pancreatic cancer cells. Cell proliferation was analyzed using CCK8, colony-formation, and EdU proliferation assays. Cell migration was evaluated through wound healing and transwell assays, as well as determination of the protein expression levels of EMT markers and ß-catenin. Apoptosis and the cell cycle were measured using flow cytometry and JC-1 staining, respectively. The protein expression levels of p-Rb, CyclinB1, P21, Cleaved-PARP, and Cleaved-Caspase3 were assessed using western blotting. RNA sequencing (RNA-seq) and bioinformatics analyses were performed to elucidate the mechanism underlying the action of Erianin in pancreatic cancer. Western blotting was used to examine the expression levels of key proteins in the AKT, JNK, and p38 MAPK signaling pathways. Molecular docking and CETSA were used to test hypotheses. The tumor-suppressive ability of Erianin in vivo was assessed using a tumor-bearing assay in nude mice. RESULTS: Network pharmacology revealed that Erianin inhibited pancreatic cancer through multiple pathways. Erianin significantly inhibited pancreatic cancer cell proliferation and migration while promoting intracellular ROS and inducing apoptosis. Mechanistically, Erianin inhibited pancreatic cancer cell proliferation by regulating the AKT/FOXO1 and ASK1/JNK/p38 MAPK signaling pathways. In vivo experiments showed that Erianin inhibited subcutaneous tumor growth and promoted tumor tissue apoptosis in nude mice. CONCLUSIONS: The component-target-pathway network revealed that Erianin exerted anti-cancer effects through multiple components, targets, and pathways. Erianin inhibited the proliferation and migration of pancreatic cancer cells and induced apoptosis through the AKT/FOXO1 and ASK1/JNK/p38 MAPK signaling pathways. These results indicate that Erianin is a promising agent for pancreatic cancer treatment.

Genome-Wide Identification of Candidate Genes Associated with Heat Stress in Mulberry (Morus alba L.).

Mulberry (Morus alba L.) is an economically important plant for the silk industry and has the possibility of contributing immensely to Chinese pharmacopeia because of its health benefits. Domesticated silkworms feed only on mulberry leaves, meaning that the worms' survival depends on the mulberry tree. Mulberry production is threatened by climate change and global warming. However, the regulatory mechanisms of mulberry responses to heat are poorly understood. We performed transcriptome analysis of high-temperature-stressed (42 °C) M. alba seedlings using RNA-Seq technologies. A total of 703 differentially expressed genes (DEGs) were discovered from 18,989 unigenes. Among these, 356 were up-regulated, and 347 were down-regulated. KEGG analysis revealed that most DEGs were enriched in valine, leucine and isoleucine degradation, and in starch and sucrose metabolism, alpha-linolenic acid metabolism, carotenoid biosynthesis and galactose metabolism, among others. In addition, TFs such as the NAC, HSF, IAA1, MYB, AP2, GATA, WRKY, HLH and TCP families were actively involved in response to high temperatures. Moreover, we used RT-qPCR to confirm the expression changes of eight genes under heat stress observed in the RNA-Seq analysis. This study provides M. alba transcriptome profiles under heat stress and provides theoretical bases to researchers for better understanding mulberry heat response mechanisms and breeding heat-tolerant mulberry plants.

Enhancement of hair growth through stimulation of hair follicle stem cells by prostaglandin E2 collagen matrix.

Prostaglandin metabolism is involved in the regulation of the periodic process of hair follicles. Preliminary research data reported that prostaglandin E2 (PGE2) exhibits potential in hair growth. However, the relevant evidence is still insufficient. Herein, we prepared a PGE2 matrix by conjugating PGE2 with collagen via crosslinkers to avoid rapid degradation of PGE2 molecules in vivo. First, we measured the physical properties of the PGE2 matrix. A mouse model of hair loss was established, and PGE2 matrix subcutaneous injection was applied to evaluate hair growth. Under different treatments with the PGE2 matrix, the morphology of hair follicles, the dynamic expression of hair follicle stem cell markers and key regulators in the hair growth cycle were explored. Our data revealed that the PGE2 matrix increased the proportion of developing hair follicles at the early growth stage. Improvements in hair follicle stem cells, such as Sox9+ and Lgr5+ cells, have also been confirmed as therapeutic effects of PGE2 to stimulate hair follicle growth. Our study indicated that PGE2 exhibits effective roles in hair development during anagen. Furthermore, the results also highlight the potential of the PGE2 delivery system as a novel therapeutic strategy for the treatment of hair disorders in the future.

Magnesium Nutrient Application Induces Metabolomics and Physiological Responses in Mulberry (Morus alba) Plants.

Mulberry (Morus alba) is a significant plant with numerous economic benefits; however, its growth and development are affected by nutrient levels. A high level of magnesium (Mg) or magnesium nutrient starvation are two of the significant Mg factors affecting plant growth and development. Nevertheless, M. alba's metabolic response to different Mg concentrations is unclear. In this study, different Mg concentrations, optimal (3 mmol/L), high (6 mmol/L and 9 mmol/L), or low (1 and 2 mmol/L) and deficient (0 mmol/L), were applied to M. alba for three weeks to evaluate their effects via physiological and metabolomics (untargeted; liquid chromatography-mass spectrometry (LC-MS)) studies. Several measured physiological traits revealed that Mg deficiency and excess Mg altered net photosynthesis, chlorophyll content, leaf Mg content and fresh weight, leading to remarkable reductions in the photosynthetic efficiency and biomass of mulberry plants. Our study reveals that an adequate supply of the nutrient Mg promoted the mulberry's physiological response parameters (net photosynthesis, chlorophyll content, leaf and root Mg content and biomass). The metabolomics data show that different Mg concentrations affect several differential metabolite expressions (DEMs), particularly fatty acyls, flavonoids, amino acids, organic acid, organooxygen compounds, prenol lipids, coumarins, steroids and steroid derivatives, cinnamic acids and derivatives. An excessive supply of Mg produced more DEMs, but negatively affected biomass production compared to low and optimum supplies of Mg. The significant DEMs correlated positively with mulberry's net photosynthesis, chlorophyll content, leaf Mg content and fresh weight. The mulberry plant's response to the application of Mg used metabolites, mainly amino acids, organic acids, fatty acyls, flavonoids and prenol lipids, in the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. These classes of compounds were mainly involved in lipid metabolism, amino acid metabolism, energy metabolism, the biosynthesis of other secondary metabolites, the biosynthesis of other amino acids, the metabolism of cofactors and vitamin pathways, indicating that mulberry plants respond to Mg concentrations by producing a divergent metabolism. The supply of Mg nutrition was an important factor influencing the induction of DEMs, and these metabolites were critical in several metabolic pathways related to magnesium nutrition. This study provides a fundamental understanding of DEMs in M. alba's response to Mg nutrition and the metabolic mechanisms involved, which may be critical to the mulberry genetic breeding program.

Organophosphorus Flame Retardants and Plasticizers in Building and Decoration Materials and Their Potential Burdens in Newly Decorated Houses in China.

Organophosphorus flame retardants (OPFRs) have been increasingly used in various building and decoration materials to fulfill fire safety standards since the phasing out of polybrominated diphenyl ethers. We determined OPFR concentrations in the most commonly used building and decoration materials available in local markets and online in China. The OPFR concentrations varied significantly, from 14.78 ng/g (putty powder) to 9649000 ng/g (expanded polystyrene panel (EPS)). Relatively high concentrations of OPFRs were found in foam samples, followed by nonwoven and polyvinyl chloride (PVC) wallpaper, PVC pipes, sealing materials, boards, and paints. Low concentrations were found mostly in wall decoration powders, suggesting that no OPFRs had been added to these powders. Tris(1-chloro-2-propyl) phosphate and tris(1,3-dichloro-2-propyl) phosphate were the most detected halogenated OPFRs, while tri-n-butyl phosphate and tris(2-butoxyethyl) phosphate were the dominant nonhalogenated OPFRs, implying that they are commonly used in building and decoration materials. The estimated OPFR burden in interior decoration using nonwoven wallpaper was 330- and 2110-fold higher than that using latex paint and diatomite, respectively. The emission periods of OPFRs from nonwoven and PVC wallpaper may be greater than 13 years. We estimated that the total burden of OPFRs for decoration using wallpaper in newly decorated houses in China is ∼63 t/y. Significantly higher concentrations of OPFRs in interior decoration materials, especially nonwoven wallpaper, pose potential health risks to the people using the buildings.

Extracellular vesicles derived from mesenchymal stem cells suppress breast cancer progression by inhibiting angiogenesis.

Previous studies have highlighted the antitumor effects of mesenchymal stem cell­derived extracellular vesicles (MSC­EVs), positioning them as a promising therapeutic avenue for cancer treatment. However, some researchers have proposed a bidirectional influence of MSC­EVs on tumors, determined by the specific tissue origin of the MSCs and the types of tumors involved. The present study aimed to elucidate the effects of human placenta MSC­derived extracellular vesicles (hPMSC­EVs) on the malignant behavior of a mouse breast cancer model of 4T1 cells in vitro and in vivo. The findings revealed that hPMSC­EVs significantly inhibited the proliferation, migration and colony formation of cultured 4T1 mouse breast cancer cells without inducing apoptosis. Exposure to conditioned medium from 4T1 cells pretreated with hPMSC­EVs resulted in decreased angiogenic activity, accompanied by the downregulation of angiogenesis­promoting genes in human umbilical vein endothelial cells. In murine xenograft models derived from the 4T1 cell line, local administration of hPMSC­EVs substantially hindered tumor growth. Further results revealed that hPMSC­EVs inhibited angiogenesis in vivo, as reflected by the use of a vascular growth factor receptor 2­Fluc transgenic mouse model. In summary, the results confirmed that hPMSC­EVs negatively modulated breast cancer growth by suppressing tumor cell proliferation and migration via an indirect antiangiogenic mechanism. These results underscored the therapeutic potential of EVs, suggesting a promising avenue for alternative anticancer treatments in the future.

The METTL3/miR-196a Axis Predicts Poor Prognosis in Non-small Cell Lung Cancer.

Background: METTL3 accelerates m6A modification to influence cancer progression including non-small cell lung cancer (NSCLC). To illustrate the role and underlying mechanism of METTL3 mediated miR-196a upregulation in NSCLC. Method: The global level of m6A modification was detected by qPCR, western blot and immumohistochemical staining. The TCGA, GEPIA, CPTAC and TIMER databases were used to explore the expression change of METTL3, miR-196a and GAS7 in NSCLC patients. Kaplan-Meier analysis was performed to analyze the prognostic value of miR-196a. NSCLC cells overexpressed or knockdown miR-196a were constructed and used for CCK8, colony formation assay, western blot and immunofluorescence in vitro. The effect of miR-196a on tumor growth was investigated in vivo. Result: We found that METTL3 mediated miR-196a were notably enhancive in NSCLC tissues and in NSCLC cells, which is markedly positively related with the serious TNM stage, the large tumor size, the distant metastasis, and the poor prognosis in patients of NSCLC. Further investigation showed that up-regulated miR-196a promoted cell viability and cell autophagy, while down-regulation of miR-196a revealed opposite results in H1299 and A549 cells. In terms of mechanism, we found that miR-196a interacted with GAS7. In addition, GAS7 expression in NSCLC patients may be positively related with the infiltration of immune cell subsets in tumor microenvironment (TME). Conclusion: The axis of METTL3-miR-196a-GAS7 might be a target for molecular targeted therapy, a potential and novel diagnostic marker for NSCLC patients.

Genome-wide transcriptome profiling of mulberry (Morus alba) response to boron deficiency and toxicity reveal candidate genes associated with boron tolerance in leaves.

Mulberry (Morus alba) is an essential plant with countless economic benefits; however, its growth and metabolic processes are hampered by boron (B) stresses. Very little research has been performed to elucidate boron tolerance and detoxification mechanisms in this species. The M. alba cultivar, Yu-711, was exposed to five different concentrations of boric acid (H3BO3), including deficient (T1; 0 mM) moderate B deficiency (T2; 0.02 mM), sufficient (CK; 0.1 mM) and toxic (T3 and T4; 0.5 and 1 mM) levels for 18 days of growth in pots experiment. Transcriptome analysis of B deficiency and toxicity treatments was performed on mulberry leaves. The transcriptome data reveal that a total of 6114 genes were differentially expressed (DEGs), of which 3830 were up-regulated and 2284 were down-regulated. A comparative analysis between treatment groups CK-vs-T1 (deficiency) and CK-vs-T4 (toxicity) indicates that 590 and 1383 genes were down-regulated in both deficiency and B toxicity, respectively. The results show that 206 genes were differentially expressed in all treatments. B deficiency and toxicity significantly altered the expression of the key aquaporins (PIP2-1, PIP2-7, PIP2-4 and NIP3-1) and high-affinity boron transporter genes (BOR1 and BOR7). In addition, boron stress also altered the expression of antioxidants and photosynthesis-related genes. B stresses were found to alter several transcription factors including ERF1B, which is associated with the regulation of boron uptake and the synthesis and signaling of phytohormones. Unravelling the mechanisms of B tolerance and detoxification is important and would give us further insight into how B stresses affect mulberry plants.

The impact of boron nutrient supply in mulberry (Morus alba) response to metabolomics, enzyme activities, and physiological parameters.

Boron (B) is essential for normal and healthy plant growth. Therefore, Boron stress is a common abiotic stress that limits plant growth and productivity. However, how mulberry copes with boron stress remains unclear. In this study, seedlings of the Morus alba cultivar, Yu-711, were treated with five different concentrations of boric acid (H3BO3), including deficient (0 and 0.02 mM), sufficient (0.1 mM) and toxic (0.5 and 1 mM) levels. Physiological parameters, enzymatic activities and non-targeted liquid chromatography-mass spectrometry (LC-MS) technique were employed to evaluate the effects of boron stress on the net photosynthetic rate (Pn), chlorophyll content, stomatal conductance (Gs), transpiration rate (Tr), intercellular CO2 concentration (Ci) and metabolome signatures. Physiological analysis revealed that Boron deficiency and toxicity induced a decline in Pn, Ci, Gs, Tr, and chlorophyll content. Also, enzymatic activities, including catalase (CAT) and superoxide dismutase (SOD), decreased, while POD activity increased in response to Boron stress. Osmotic substances such as soluble sugars, soluble proteins, and proline (PRO) presented elevated levels under all Boron concentrations. Metabolome analysis indicated that differential metabolites, including amino acids, secondary metabolites, carbohydrates, and lipids, played a key role in Yu-711's response to Boron stress. These metabolites were mainly involved in amino acid metabolism, biosynthesis of other secondary metabolites, lipid metabolism, metabolism of cofactors and vitamins, and metabolism of other amino acids pathways. Our findings reveal the various metabolites pathways in mulberry response to boron nutrient supply and may serve as fundamental knowledge in breeding resistance mulberry plants, so that it can cope with climate changes.

Functional Characterization of MaZIP4, a Gene Regulating Copper Stress Tolerance in Mulberry (Morus atropurpurea R.).

ZIP4 (zinc transporter 4) plays important roles in transporting Cu2+ ions in plants, which may contribute to the maintenance of plant metal homeostasis in growth, plant development and normal physiological metabolism. However, ZIP4 transporters have not been described in mulberry and the exact function of ZIP4 transporters in regulating the homeostasis of Cu in mulberry remains unclear. In this study, a new ZIP4 gene (MaZIP4) was isolated and cloned from Morus atropurpurea R. Phylogenetic analysis of amino sequences suggested that the amino-acid sequence of the MaZIP4 protein shows high homology with other ZIP4 proteins of Morus notabilis, Trema orientale, Ziziphus jujube and Cannabis sativa. In addition, a MaZIP4 silenced line was successfully constructed using virus-induced gene silencing (VIGS). The analysis of MaZIP4 expression by quantitative real-time PCR in mulberry showed that the level of MaZIP4 expression increased with increasing Cu concentration until the Cu concentration reached 800 ppm. Relative to the blank (WT) and the negative controls, malondialdehyde (MDA) levels increased significantly and rose with increasing Cu concentration in the MaZIP4 silenced line, whereas the soluble protein and proline content, superoxide dismutase (SOD) and peroxidase (POD) activities of these transgenic plants were lower. These results indicated that MaZIP4 may play an important role in the resistance of mulberry to Cu stress.

ATAC-seq exposes differences in chromatin accessibility leading to distinct leaf shapes in mulberry.

Mulberry leaf shape is an important agronomic trait indicating yield, growth, development, and habitat variation. China was the earliest country in the world to grow mulberry for sericulture, and it is also one of the great contributions of the Chinese nation to human civilization. ATAC-seq (Assay for Transposase Accessible Chromatin using sequencing) is a recently developed technique for genome-wide analysis of chromatin accessibility. The samples used for ATAC sequencing in this study were divided into two groups of whole leaves (CK-1 and CK-2) and lobed leaves (HL-1 and HL-2), with two replicates in each group. The related motif analysis, differential expression motif screening, and functional annotation of mulberry leaf shape differences were performed by raw letter analysis to finally obtain the transcription factors (TFs) that lead to the production of heteromorphic leaves. These transcription factors are common in plants, especially the TCP family, shown to be associated with leaf development and growth in other woody plants and are a potential transcription factor responsible for leaf shape differences in mulberry. Dissecting the regulatory mechanisms of leaf shape of different forms of mulberry leaves by ATAC-seq is an important way to protect mulberry germplasm resources and improve mulberry yield. It is conducive to cultivating mulberry varieties with high resistance to adversity, promoting the sustainable development of sericulture, and protecting and improving the ecological environment.

DNA Methylation Changes and Its Associated Genes in Mulberry (Morus alba L.) Yu-711 Response to Drought Stress Using MethylRAD Sequencing.

Drought stress remains one of the most detrimental environmental cues affecting plant growth and survival. In this work, the DNA methylome changes in mulberry leaves under drought stress (EG) and control (CK) and their impact on gene regulation were investigated by MethylRAD sequencing. The results show 138,464 (37.37%) and 56,241 (28.81%) methylation at the CG and CWG sites (W = A or T), respectively, in the mulberry genome between drought stress and control. The distribution of the methylome was prevalent in the intergenic, exonic, intronic and downstream regions of the mulberry plant genome. In addition, we discovered 170 DMGs (129 in CG sites and 41 in CWG sites) and 581 DMS (413 in CG sites and 168 in CWG sites). Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicates that phenylpropanoid biosynthesis, spliceosome, amino acid biosynthesis, carbon metabolism, RNA transport, plant hormone, signal transduction pathways, and quorum sensing play a crucial role in mulberry response to drought stress. Furthermore, the qRT-PCR analysis indicates that the selected 23 genes enriched in the KEGG pathways are differentially expressed, and 86.96% of the genes share downregulated methylation and 13.04% share upregulation methylation status, indicating the complex link between DNA methylation and gene regulation. This study serves as fundamentals in discovering the epigenomic status and the pathways that will significantly enhance mulberry breeding for adaptation to a wide range of environments.

Long noncoding RNA transcriptome analysis reveals novel lncRNAs in Morus alba 'Yu-711' response to drought stress.

Drought stress has been a key environmental factor affecting plant growth and development. The plant genome is capable of producing long noncoding RNAs (lncRNAs). To better understand white mulberry (Morus alba L.) drought response mechanism, we conducted a comparative transcriptome study comparing two treatments: drought-stressed (EG) and well-watered (CK) plants. A total of 674 differentially expressed lncRNAs (DElncRNAs) were identified. In addition, 782 differentially expressed messenger RNAs (DEmRNAs) were identified. We conducted Gene Ontology (GO) and KEGG enrichment analyses focusing on the differential lncRNAs cis-target genes. The target genes of the DElncRNAs were most significantly involved in the biosynthesis of secondary metabolites. Gene regulatory networks of the target genes involving DElncRNAs-mRNAs-DEmRNAs and DElncRNA-miRNA-DEmRNA were constructed. In the DElncRNAs-DEmRNAs network, 30 DEmRNAs involved in the biosynthesis of secondary metabolites are collocated with 46 DElncRNAs. The interaction between DElncRNAs and candidate genes was identified using LncTar. In summary, quantitative real-time polymerase chain reaction (qRT-PCR) validated nine candidate genes and seven target lncRNAs including those identified by LncTar. We predicted that the DElncRNAs-DEmRNAs might recruit microRNAs (miRNAs) to interact with gene regulatory networks under the drought stress response in mulberry. The findings will contribute to our understanding of the regulatory functions of lncRNAs under drought stress and will shed new light on the mulberry-drought stress interactions.

Metabolomics Response to Drought Stress in Morus alba L. Variety Yu-711.

Mulberry is an economically significant crop for the sericulture industry worldwide. Stresses such as drought exposure have a significant influence on plant survival. Because metabolome directly reflects plant physiological condition, performing a global metabolomic analysis is one technique to examine this influence. Using a liquid chromatography-mass spectrometry (LC-MS) technique based on an untargeted metabolomic approach, the effect of drought stress on mulberry Yu-711 metabolic balance was examined. For this objective, Yu-711 leaves were subjected to two weeks of drought stress treatment and control without drought stress. Numerous differentially accumulated metabolic components in response to drought stress treatment were revealed by multivariate and univariate statistical analysis. Drought stress treatment (EG) revealed a more differentiated metabolite response than the control (CK). We found that the levels of total lipids, galactolipids, and phospholipids (PC, PA, PE) were significantly altered, producing 48% of the total differentially expressed metabolites. Fatty acyls components were the most abundant lipids expressed and decreased considerably by 73.6%. On the other hand, the prenol lipids class of lipids increased in drought leaves. Other classes of metabolites, including polyphenols (flavonoids and cinnamic acid), organic acid (amino acids), carbohydrates, benzenoids, and organoheterocyclic, had a dynamic trend in response to the drought stress. However, their levels under drought stress decreased significantly compared to the control. These findings give an overview for the understanding of global plant metabolic changes in defense mechanisms by revealing the mulberry plant metabolic profile through differentially accumulated compounds.

Polycyclic aromatic hydrocarbons in the atmosphere and soils of Dalian, China: Source, urban-rural gradient, and air-soil exchange.

We investigated the concentrations, distributions, and sources of PAHs in the air and soils of Dalian, China, as well as their air-soil exchange trends. Total concentrations of PAHs in the air ranged from 6.37 to 124 ng/m3 with an average of 23.1 ± 26.6 ng/m3, while Σ15PAHs in the soils ranged from 42.8 to 28600 ng/g with an average of 2580 ± 5730 ng/g. Significant spatial distribution of PAHs was discovered in the soils with a clear urban-suburban-rural decreasing gradient, suggesting urban area is more contaminated by PAHs due to frequent and intensive human activities. However, high PAH concentrations were also discovered in the air from several rural sites, implying some PAH sources have shifted from urban to suburban or rural areas. Source apportionment indicated that major sources of PAHs in the urban and suburban soils were traffic emission/oil spill and coal combustion respectively, whereas major sources in the rural soils were diverse. Air-soil partitioning result suggested that 3-ring PAHs were mostly volatilized from soil, 6-ring PAHs were deposited into soil, while the trends of 4∼5-ring PAHs varied with sampling site. Fluoranthene, Pyrene, and Chrysene were mostly discovered to be volatilized in the urban and suburban areas, but equilibrium or deposited in the rural area, indicating a potential urban-to-rural transport of PAHs. The atmospheric transport and source shift of PAHs from urban to rural areas highlighted the importance of PAH source control on a regional scale.

Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in the air of Dalian, China: Correlations with six criteria air pollutants and meteorological conditions.

Concentrations and temporal variations of priority polycyclic aromatic hydrocarbons (PAHs) in the air from a suburban area of Dalian, China were investigated for a 1-year period to assess their sources and potential correlations with six criteria air pollutants and meteorological parameters. The total concentrations of PAHs were in the range of 4.32-112.2 ng/m3 (Mean = 52.37 ±â€¯23.99 ng/m3). Seasonality was discovered with the PAHs following an order of winter > spring > summer > autumn. The impacts of meteorological parameters on PAH levels were season-dependent. High temperature may increase the air concentrations of 4-ring PAHs during the non-heating period, whereas high relative humidity may raise the concentrations of 3- and 4-ring PAHs during the heating period. Correlations of PAHs with criteria air pollutants, such as SO2, NO2, and O3, indicated that both fossil fuel combustion and photochemical oxidation influenced the air concentrations of PAHs. According to the source apportionment by diagnostic ratios and PMF model, coal combustion and traffic emission were estimated to be the main sources of PAHs in Dalian, followed by petroleum release and biomass burning. It was worth noting that the contribution of coal combustion to the PAH burdens increased from 26% to 45% due to the emission from domestic heating in winter. This extra emission needs a continuous concern in the future.

Seasonal variation, air-water exchange, and multivariate source apportionment of polycyclic aromatic hydrocarbons in the coastal area of Dalian, China.

The concentrations and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) in air and seawater dissolved samples from the coastal area of Dalian were investigated, as well as their air-water exchanges. The average concentrations of PAHs were 27.5 ±â€¯14.6 ng/m3 and 49.5 ±â€¯20.5 ng/L in the air and water, respectively. Phenanthrene was the dominant congener in both air and water dissolved phase. Seasonality was discovered in the air with the concentrations higher in winter than in summer, but not in the water dissolved phase. Air-water exchange trends also displayed apparent seasonality with 3-4 ring PAHs generally being volatilization or equilibrium in summer but deposition in winter, which highlighted the important influence of temperature on the air-water exchange direction of PAHs. The air-water exchange fluxes of individual PAH congeners ranged from -24331 to 6541 ng/m2/d, and the highest deposition and volatilization fluxes both appeared at the industrial areas, which emphasized the influence of point source emission to the magnitude of air-water diffusion flux of PAHs. Multivariate source apportionment approaches, including principle component analysis, diagnostic ratios, and positive matrix factorization, were conducted, which suggested that PAHs in water originated from multiple sources. Frequent port transport correlated vehicle/ship emission rather than coal combustion may be the primary contributor of PAHs to the coastal air and water.

Halogenated flame retardants in building and decoration materials in China: Implications for human exposure via inhalation and dust ingestion.

In this study, polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and dechlorane plus (DPs) were analyzed in seven categories of building and decoration materials. The total concentrations of analyzed FRs ranged from 1.19 ng/g (diatomite powder) to 9532 ng/g (expanded polystyrene panel). Relatively high concentrations were detected in foam samples and PVC materials, followed by sealing materials, boards, wallpaper, paints, and wall decoration powders. BDE209 was the most detected compound with the highest concentrations in almost all materials, followed by decabromodiphenyl ethane (DBDPE), which was consistent with their productions and consumptions in China. The estimated PBDE concentrations in air and dust based on material concentration and emission rate were comparable with those detected in real samples. Adult and infant exposures via inhalation and dust ingestion were assessed. The estimated exposures to BDE209 via dust ingestion were 1.36 and 0.12 ng/(kg bw d), which were 19- and 4-fold higher than those via inhalation for infants and adults, respectively. This suggested that dust ingestion was a significant pathway of human BDE209 exposure, especially for infants. For the other PBDE congeners (∑7PBDEs), the estimated exposures via inhalation were 2.60 and 1.32 ng/(kg bw d) for infants and adults, respectively. Despite the low estimated human exposures to PBDEs compared to the oral reference doses, the exposure associated with building and decoration materials still requires more attention because of the potential risks from other exposure pathways and undetected FRs in those materials.

Occurrence, distribution, and air-water exchange of organophosphorus flame retardants in a typical coastal area of China.

Organophosphorus flame retardants (OPFRs) have been detected ubiquitously in the air and water worldwide, but no study has focused on their air-water exchange process. Here, we investigated the concentrations, distributions, and seasonal variations of OPFRs in the coastal air and water of Dalian, China. The total concentrations of 10 OPFRs in the air based on passive air sampling ranged from 0.50 to 20.0 ng/m3, while the concentrations of OPFRs in the water dissolved phase ranged from 48.3 to 681 ng/L. Relatively high concentrations were mainly discovered near the industry areas or river estuaries, suggesting that point sources along the coastline may significantly influence the local OPFR concentrations. Tris(2-chloroisopropyl) phosphate (TCIPP) was the most dominant congener followed by tris(2-chloroethyl) phosphate (TCEP), which was consistent with their high production and persistence. The air-water gaseous exchanges of OPFRs were estimated for the first time according to their concentrations in gaseous and dissolved phases. Generally, the gaseous exchange fluxes varied with sampling site and period. TCIPP showed the highest gaseous deposition flux of -395 ±â€¯1211 ng/(m2 d), while TCEP showed the highest emission flux of 1414 ±â€¯2093 ng/(m2 d). The dry deposition fluxes of OPFRs (0.05-822 ng/(m2 d)) were also calculated based on their particle fractions in the air. The result suggested that both gaseous exchange and particle deposition processes significantly influenced the air-water transport of OPFRs in this area.

Organophosphate esters in sediment cores from coastal Laizhou Bay of the Bohai Sea, China.

Concentrations and vertical distributions of organophosphate esters (OPEs) were investigated in the sediment cores collected from the Laizhou Bay, Bohai Sea of China. The total concentrations of OPEs in the sediment core (CA) collected near the Yellow River Estuary were in the range of 11.8-102ng/g, while the total concentrations in the sediment core (CB) near a mariculture area were 6.65-41.5ng/g. Significantly high concentrations of OPEs were found in the sediments near the Yellow River Estuary than those in the mariculture area. Vertical distributions in the sediment cores demonstrated a recent increase of OPE emissions, especially for tri-n-butyl phosphate (TnBP), tris (2-chloroethyl) phosphate (TCEP), and tris (2-chloroisopropyl) phosphate (TCPP). Generally, TCEP and TCPP were the dominant congeners in the sediment cores, while the profiles of TnBP were increase in the surface 0-20cm layers of the CA core. OPEs in the CA core may be remarkably influenced by the discharge of Yellow River, whereas OPEs in the CB core may originate from the transport through seawater. The remarkable increase of OPE flame retardants in the surface sediments raises the concern about their emissions and risks to the environment and indicates the need for further monitoring.