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ConspectusElectrides make up a fascinating group of materials with unique physical and chemical properties. In these materials, excess electrons do not behave like normal electrons in metals or form any chemical bonds with atoms. Instead, they "float" freely in the gaps within the material's structure, acting like negatively charged particles called anions (see the graph). Recently, there has been a surge of interest in van der Waals (vdW) electrides or electrenes in two dimensions. A typical example is layered lanthanum bromide (LaBr2), which can be taken as [La3+(Br1-)2]+â¢(e-). Each excess free electron is trapped within a hexagonal pore, forming dense dots of electron density. These anionic electrons are loosely bound, giving vdW electrides some unique properties such as ferromagnetism, superconductivity, topological features, and Dirac plasmons. The high density of the free electron makes electrides very promising for applications in thermionic emission, organic light-emitting diodes, and high-performance catalysts.In this Account, we first discuss the discovery of numerous vdW electrides through high-throughput computational screening of over 67,000 known inorganic crystals in Materials Project. A dozen of them have been newly discovered and have not been reported before. Importantly, they possess completely different structural prototypes and properties of anionic electrons compared to widely studied electrides such as Ca2N. Finding these new vdW electrides expands the variety of electrides that can be made in the experiment and opens up new possibilities for studying their unique properties and applications.Then, based on the screened vdW electrides, we delve into their various emerging properties. For example, we developed a new magnetic mechanism specific to atomic-orbital-free ferromagnetism in electrides. We uncover the dual localized and extended nature of the anionic electrons in such electrides and demonstrate the formation of the local moment by the localized feature and the ferromagnetic interaction by the direct overlapping of their extended states. We further show the effective tuning of the magnetic properties of vdW electrides by engineering their structural, electronic, and compositional properties. Besides, we show that the complex interaction between the multiple quantum orderings in vdW electrides leads to many interesting properties including valley polarization, charge density waves, a topological property, a superconducting property, and a thermoelectrical property.Moreover, we discuss strategies to leverage the unique intrinsic properties of vdW electrides for practical applications. We show that these properties make vdW electrides potential candidates for advanced applications such as spin-orbit torque memory devices, valleytronic devices, K-ion batteries, and thermoelectricity. Finally, we discuss the current challenges and future perspectives for research using these emerging materials.
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Defect engineering is widely used to impart the desired functionalities on materials. Despite the widespread application of atomic-resolution scanning transmission electron microscopy (STEM), traditional methods for defect analysis are highly sensitive to random noise and human bias. While deep learning (DL) presents a viable alternative, it requires extensive amounts of training data with labeled ground truth. Herein, employing cycle generative adversarial networks (CycleGAN) and U-Nets, we propose a method based on a single experimental STEM image to tackle high annotation costs and image noise for defect detection. Not only atomic defects but also oxygen dopants in monolayer MoS2 are visualized. The method can be readily extended to other two-dimensional systems, as the training is based on unit-cell-level images. Therefore, our results outline novel ways to train the model with minimal data sets, offering great opportunities to fully exploit the power of DL in the materials science community.
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Background: Non-alcoholic fatty liver disease (NAFLD) is a type of liver metabolic syndrome. Employing multi-omics analyses encompassing the microbiome, metabolome and transcriptome is crucial for comprehensively elucidating the biological processes underlying NAFLD. Methods: Hepatic tissue, blood and fecal samples were obtained from 9 NAFLD model mice and 8 normal control mice. Total fecal microbiota DNA was extracted, and 16S rRNA was amplified, to analyze alterations in the gut microbiota (GM) induced by NAFLD. Subsequently, diagnostic strains for NAFLD were screened, and their functional aspects were examined. Differential metabolites and differentially expressed genes were also screened, followed by enrichment analysis. Correlations between the differential microbiota and metabolites, as well as between the DEGs and differential metabolites were studied. A collinear network involving key genes-, microbiota-and metabolites was constructed. Results: Ileibacterium and Ruminococcaceae, both belonging to Firmicutes; Olsenella, Duncaniella and Paramuribaculum from Bacteroidota; and Bifidobacterium, Coriobacteriaceae_UCG_002 and Olsenella from Actinobacteriota were identified as characteristic strains associated with NAFLD. Additionally, differentially expressed metabolites were predominantly enriched in tryptophan, linoleic acid and methylhistidine metabolism pathways. The functions of 2,510 differentially expressed genes were found to be associated with disease occurrence. Furthermore, a network comprising 8 key strains, 14 key genes and 83 key metabolites was constructed. Conclusion: Through this study, we conducted a comprehensive analysis of NAFLD alterations, exploring the gut microbiota, genes and metabolites of the results offer insights into the speculated biological mechanisms underlying NAFLD.
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Given their relatively low persistence and mammalian toxicity, neonicotinoid pesticides have been extensively used worldwide and are omnipresent in the environment. Recent studies have shown that neonicotinoids may pose adverse effects on non-target organisms other than the known neurotoxicity, raising emerging concerns that these insecticides might pose human health risk through additional toxicity pathways. In the present study, the mitochondria function, oxidative stress, DNA damages, and genes transcription levels were examined in the human neuroblastoma SH-SY5Y cells after 48-h exposure to imidacloprid at concentrations from 0.05 to 200 µmol/L. Results showed that imidacloprid induced mitochondrial dysfunction with the degradation of adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP) levels. In addition, imidacloprid caused oxidative stress by stimulating the generation of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) via the disruption of calcium ion level and mitochondrial function. Ultimately, the oxidative stress continued to produce DNA damage and apoptosis in SH-SY5Y cells at imidacloprid concentrations above 47.6 µmol/L. Among the evaluated endpoints, ATP was the most sensitive, with a median activity concentration of 0.74 µmol/L. The 5 % hazard concentration of imidacloprid was estimated to be 0.69 µmol/L, which can be used as a threshold for human health risk assessment for imidacloprid. Collectively, our results provide an important support for further research on potential toxicity of neonicotinoids related to mitochondrial toxicity in humans.
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A diversity of contaminants of emerging concern (CECs) are present in wastewater effluent, posing potential threats to receiving waters. It is urgent for a holistic assessment of the occurrence and risk of CECs related to wastewater treatment plants (WWTP) on national and regional scales. A data mining-based risk prioritization method was developed to collect the reported contaminants and their respective concentrations in municipal and industrial WWTPs and their receiving waters across China over the past 20 years. A total of 10,781 chemicals were reported in 8336 publications, of which 1037 contaminants were reported with environmental concentrations. While contaminant categories varied across WWTP types (municipal vs. industrial) and regions, pharmaceuticals and cyclic hydrocarbons were the most studied CECs. Contaminant composition in receiving water was closer to that in municipal than industrial WWTPs. Publications on legacy pesticides and polycyclic aromatic hydrocarbons in WWTP decreased recently compared to the past, while pharmaceuticals and perfluorochemicals have received increasing attention, showing a changing concern over time. Detection frequency, concentration, removal efficiency, and toxicity data were integrated for assessing potential risks and prioritizing CECs on national and regional scales using an environmental health prioritization index (EHPi) approach. Among 666 contaminants in municipal WWTP effluent, trichlorfon and perfluorooctanesulfonic acid were with the highest EHPi scores, while 17É-ethinylestradiol and bisphenol A had the highest EHPi scores among 304 contaminants in industrial WWTPs. The prioritized contaminants varied across regions, suggesting a need for tailoring regional measures of wastewater treatment and control.
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BACKGROUND: This study aimed to investigate the efficacy and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) for primary prophylaxis of neutropenia in patients with cervical cancer receiving concurrent chemoradiotherapy. METHODS: In this prospective, single-center, single-arm study, we enrolled patients (18-70 years) with 2018 International Federation of Gynecology and Obstetrics (FIGO) stage IIIC1r-IVA and IVB (distant metastasis only with inguinal lymph node metastasis) cervical cancer. Eligible patients should have normal function of the bone marrow (absolute neutrophil count (ANC) ≥ 2.0 × 109/L) and adequate hepatic and renal functions. Key exclusion criteria included: previous chemotherapy and/or radiotherapy; a history of bone marrow dysplasia or other hematopoietic abnormalities. All patients underwent radical radiotherapy (pelvic radiotherapy or extended-field irradiation) plus brachytherapy. The chemotherapy regimen included four cycles of 3-weekly paclitaxel and cisplatin. PEG-rhG-CSF was administered 48-72 h after each treatment cycle. Salvage granulocyte colony-stimulating factor (G-CSF) was only permitted in certain circumstances. The primary endpoint was the incidence of grade 3-4 neutropenia. The secondary endpoints included frequency of febrile neutropenia (FN), chemotherapy completion rate in cycles 2-4, time to complete radiotherapy, and safety. RESULTS: Overall, 52 patients were enrolled in this study from July 2019 to October 2020. The incidence of grade 3-4 neutropenia was 28.8%, with an average duration of grade 3-4 neutropenia persistence of 3.85 days (1-7 days). The incidence rate of FN was 3.8%. The chemotherapy completion rate was 94.2%, 82.7%, and 75.0% for cycles 2-4, respectively. The incidences of grade 3-4 neutropenia for cycles 1-4 were 9.6% (5/52), 8.2% (4/49), 14.0% (6/43), and 2.6% (1/39), respectively. All patients completed radiotherapy within 8 weeks (median, 48 days; range: 41-56 days), except one patient who withdrew consent and did not receive radiotherapy. Severe non-hematologic toxicity was not observed in any patient. CONCLUSION: PEG-rhG-CSF is an effective and safe prophylactic treatment for neutropenia in patients with cervical cancer undergoing concurrent chemoradiotherapy. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR1900024494. Date of Registration:13/July/2019.
Subject(s)
Chemoradiotherapy , Granulocyte Colony-Stimulating Factor , Neutropenia , Polyethylene Glycols , Recombinant Proteins , Uterine Cervical Neoplasms , Humans , Uterine Cervical Neoplasms/therapy , Female , Middle Aged , Adult , Prospective Studies , Chemoradiotherapy/adverse effects , Chemoradiotherapy/methods , Granulocyte Colony-Stimulating Factor/therapeutic use , Granulocyte Colony-Stimulating Factor/administration & dosage , Polyethylene Glycols/administration & dosage , Polyethylene Glycols/therapeutic use , Polyethylene Glycols/adverse effects , Recombinant Proteins/administration & dosage , Recombinant Proteins/therapeutic use , Aged , Neutropenia/prevention & control , Neutropenia/etiology , Cisplatin/adverse effects , Cisplatin/therapeutic use , Cisplatin/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Young Adult , Adolescent , Paclitaxel/adverse effects , Paclitaxel/administration & dosage , Paclitaxel/therapeutic useABSTRACT
Background: Acute hematologic toxicity (HT) is a prevalent adverse tissue reaction observed in cervical cancer patients undergoing chemoradiotherapy (CRT), which may lead to various negative effects such as compromised therapeutic efficacy and prolonged treatment duration. Accurate prediction of HT occurrence prior to CRT remains challenging. Methods: A discovery dataset comprising 478 continuous cervical cancer patients (140 HT patients) and a validation dataset consisting of 205 patients (52 HT patients) were retrospectively enrolled. Both datasets were categorized into the CRT group and radiotherapy (RT)-alone group based on the treatment regimen, i.e., whether chemotherapy was administered within the focused RT duration. Radiomics features were derived by contouring three regions of interest (ROIs)-bone marrow (BM), femoral head (FH), and clinical target volume (CTV)-on the treatment planning CT images before RT. A comprehensive model combining the radiomics features as well as the demographic, clinical, and dosimetric features was constructed to classify patients exhibiting acute HT symptoms in the CRT group, RT group, and combination group. Furthermore, the time-to-event analysis of the discriminative ROI was performed on all patients with acute HT to understand the HT temporal progression. Results: Among three ROIs, BM exhibited the best performance in classifying acute HT, which was verified across all patient groups in both discovery and validation datasets. Among different patient groups in the discovery dataset, acute HT was more precisely predicted in the CRT group [area under the curve (AUC) = 0.779, 95% CI: 0.657-0.874] than that in the RT-alone (AUC = 0.686, 95% CI: 0.529-0.817) or combination group (AUC = 0.748, 95% CI: 0.655-0.827). The predictive results in the validation dataset similarly coincided with those in the discovery dataset: CRT group (AUC = 0.802, 95% CI: 0.669-0.914), RT-alone group (AUC = 0.737, 95% CI: 0.612-0.862), and combination group (AUC = 0.793, 95% CI: 0.713-0.874). In addition, distinct feature sets were adopted for different patient groups. Moreover, the predicted HT risk of BM was also indicative of the HT temporal progression. Conclusions: HT prediction in cervical patients is dependent on both the treatment regimen and ROI selection, and BM is closely related to the occurrence and progression of HT, especially for CRT patients.
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Identifying causative toxicants in mixtures is critical, but this task is challenging when mixtures contain multiple chemical classes. Effect-based methods are used to complement chemical analyses to identify toxicants, yet conventional bioassays typically rely on an apical and/or single endpoint, providing limited diagnostic potential to guide chemical prioritization. We proposed an event-driven taxonomy framework for mixture risk assessment that relied on high-throughput screening bioassays and toxicant identification integrated by deep learning. In this work, the framework was evaluated using chemical mixtures in sediments eliciting aryl-hydrocarbon receptor activation and oxidative stress response. Mixture prediction using target analysis explained <10% of observed sediment bioactivity. To identify additional contaminants, two deep learning models were developed to predict fingerprints of a pool of bioactive substances (event driver fingerprint, EDFP) and convert these candidates to MS-readable information (event driver ion, EDION) for nontarget analysis. Two libraries with 121 and 118 fingerprints were established, and 247 bioactive compounds were identified at confidence level 2 or 3 in sediment extract using GC-qToF-MS. Among them, 12 toxicants were analytically confirmed using reference standards. Collectively, we present a "bioactivity-signature-toxicant" strategy to deconvolute mixtures and to connect patchy data sets and guide nontarget analysis for diverse chemicals that elicit the same bioactivity.
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Agricultural applications of nanotechnologies necessitate addressing safety concerns associated with nanopesticides, yet research has not adequately elucidated potential environmental risks between nanopesticides and their conventional counterparts. To address this gap, we investigated the risk of nanopesticides by comparing the ecotoxicity of nanoencapsulated imidacloprid (nano-IMI) with its active ingredient to nontarget freshwater organisms (embryonic Danio rerio, Daphnia magna, and Chironomus kiinensis). Nano-IMI elicited approximately 5 times higher toxicity than IMI to zebrafish embryos with and without chorion, while no significant difference was observed between the two invertebrates. Toxicokinetics further explained the differential toxicity patterns of the two IMI analogues. One-compartmental two-phase toxicokinetic modeling showed that nano-IMI exhibited significantly slower elimination and subsequently higher bioaccumulation potential than IMI in zebrafish embryos (dechorinated), while no disparity in toxicokinetics was observed between nano-IMI and IMI in D. magna and C. kiinensis. A two-compartmental toxicokinetic model successfully simulated the slow elimination of IMI from C. kiinensis and confirmed that both analogues of IMI reached toxicologically relevant targets at similar levels. Although nanopesticides exhibit comparable or elevated toxicity, future work is of utmost importance to properly understand the life cycle risks from production to end-of-life exposures, which helps establish optimal management measures before their widespread applications.
Subject(s)
Fresh Water , Toxicokinetics , Zebrafish , Animals , Fresh Water/chemistry , Water Pollutants, Chemical/toxicity , Daphnia/drug effects , Neonicotinoids/toxicityABSTRACT
Grain shape is one of the most important factors that affects rice yield. Cloning novel grain shape genes and analyzing their genetic mechanisms are crucial for high yield breeding. In this study, a slender grain CSSL-Z485 with 3-segments substitution in the genetic background of Nipponbare was constructed in rice. Cytological analysis showed that the longer grain length of Z485 was related to the increase in glume cell numbers, while the narrower grain width was associated with the decrease in cell width. Three grain shape-related quantitative trait locus (QTLs), including qGL12, qGW12, and qRLW12, were identified through the F2 population constructed from a cross between Nipponbare and Z485. Furthermore, four single segment substitution lines (SSSLs, S1-S4) carrying the target QTLs were dissected from Z485 by MAS. Finally, three candidate genes of qGL12 for grain length and qGW12 for grain width located in S3 were confirmed by DNA sequencing, RT-qPCR, and protein structure prediction. Specifically, candidate gene 1 encodes a ubiquitin family protein, while candidate genes 2 and 3 encode zinc finger proteins. The results provide valuable germplasm resources for cloning novel grain shape genes and molecular breeding by design. Supplementary information: The online version contains supplementary material available at 10.1007/s11032-024-01480-x.
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To cope with the damage from oxidative stress caused by hypoxia, mammals have evolved a series of physiological and biochemical traits, including antioxidant ability. Although numerous research studies about the mechanisms of hypoxia evolution have been reported, the molecular mechanisms of antioxidase-related genes in mammals living in different environments are yet to be completely understood. In this study, we constructed a dataset comprising 7 antioxidase-related genes (CAT, SOD1, SOD2, SOD3, GPX1, GPX2, and GPX3) from 43 mammalian species to implement evolutionary analysis. The results showed that six genes (CAT, SOD1, SOD2, SOD3, GPX1, and GPX3) have undergone divergent evolution based on the free-ratio (M1) model. Furthermore, multi-ratio model analyses uncovered the divergent evolution between hypoxic and non-hypoxic lineages, as well as various hypoxic lineages. In addition, the branch-site model identified 9 positively selected branches in 6 genes (CAT, SOD1, SOD2, SOD3, GPX2, and GPX3) that contained 35 positively selected sites, among which 31 positively selected sites were identified in hypoxia-tolerant branches, accounting for 89% of the total number of positively selected sites. Interestingly, 65 parallel/convergent sites were identified in the 7 genes. In summary, antioxidase-related genes are subjected to different selective pressures among hypoxia-tolerant species living in different habitats. This study provides a valuable insight into the molecular evolution of antioxidase-related genes in hypoxia evolution in mammals.
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Non-centrosymmetric topological material has attracted intense attention due to its superior characteristics as compared with the centrosymmetric one, although probing the local quantum geometry in non-centrosymmetric topological material remains challenging. The non-linear Hall (NLH) effect provides an ideal tool to investigate the local quantum geometry. Here, we report a non-centrosymmetric topological phase in ZrTe5, probed by using the NLH effect. The angle-resolved and temperature-dependent NLH measurement reveals the inversion and ab-plane mirror symmetries breaking at <30 K, consistently with our theoretical calculation. Our findings identify a new non-centrosymmetric phase of ZrTe5 and provide a platform to probe and control local quantum geometry via crystal symmetries.
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Commercial chemicals, such as synthetic musks, are of global concern, but data on their occurrence and spatial distribution in aquatic environments of large scale are scarce. Two sampling campaigns were conducted in the present study to measure freely dissolved synthetic musks in freshwaters across China using passive samplers, along with biological coexposure at selected sites. Polycyclic musks (PCMs) dominated synthetic musks, with a detection frequency of 95%. Higher concentrations of PCMs were observed in densely populated Mid, East, and South China compared to less populated regions, indicating the significance of anthropogenic activities for synthetic musks in water. The concentration ratios of galaxolide (HHCB)/tonalide (AHTN) were significantly higher in low-latitude areas than in high-latitude areas from June to September, suggesting that solar radiation played an important role in the degradation of HHCB/AHTN. Significant correlations were found between dissolved concentrations of HHCB and AHTN and their lipid-normalized concentrations in coexposed fish and clam. The estimated hazard quotients for HHCB and AHTN in freshwater fish consumed by humans were less than 0.01 at all sampling sites except the Yangtze River Basin. These results help to understand the environmental fate and ecological risks of synthetic musks on a large geographical scale.
Subject(s)
Fresh Water , Water Pollutants, Chemical , China , Water Pollutants, Chemical/analysis , Fresh Water/chemistry , Environmental Monitoring , Bioaccumulation , Benzopyrans , Animals , Tetrahydronaphthalenes/analysis , Fishes/metabolism , Fatty Acids, MonounsaturatedABSTRACT
Effect-directed analysis (EDA) has been increasingly used for screening toxic contaminants in the environment, but conventional EDA procedures are often time-consuming and labor-extensive. This challenges the use of EDA for toxicant identification in the scenarios when quick answers are demanded. Herein, a solid phase microextraction ligand fishing (SPME-LF) strategy has been proposed as a rapid EDA approach for identifying acetylcholinesterase (AChE) active compounds in water. The feasibility of ligand fishing techniques for screening AChE active chemicals from environmental mixtures was first verified by a membrane separation method. Then, SPME fibers were prepared through self-assembly of boronic acid groups with AChE via co-bonding and applied for SPME-LF. As AChE coated SPME fibers selectively enriched AChE-active compounds from water, comparing sorbing compounds by the SPME fibers with and without AChE coating can quickly distinguish AChE toxicants in mixtures. Compared with conventional EDA, SPME-LF does not require repeating sample separations and bioassays, endowing SPME-LF with the merits of low-cost, labor-saving, and user-friendly. It is believed that cost-efficient and easy-to-use SPME-LF strategy can potentially be a rapid EDA method for screening receptor-specific toxicants in aquatic environment, especially applicable in time-sensitive screening.
Subject(s)
Acetylcholinesterase , Solid Phase Microextraction , Water Pollutants, Chemical , Acetylcholinesterase/metabolism , Solid Phase Microextraction/methods , Water Pollutants, Chemical/analysis , Ligands , Environmental Monitoring/methods , Cholinesterase Inhibitors/analysisABSTRACT
Microplastics (MPs) and antibiotics co-occur widely in the environment and pose combined risk to microbial communities. The present study investigated the effects of erythromycin on biofilm formation and resistance mutation of a model bacterium, E. coli, on the surface of pristine and UV-aged polystyrene (PS) MPs sized 1-2 mm. The properties of UV-aged PS were significantly altered compared to pristine PS, with notable increases in specific surface area, carbonyl index, hydrophilicity, and hydroxyl radical content. Importantly, the adsorption capacity of UV-aged PS towards erythromycin was approximately 8-fold higher than that of pristine PS. Biofilms colonizing on UV-aged PS had a greater cell count (5.6 × 108 CFU mg-1) and a higher frequency of resistance mutation (1.0 × 10-7) than those on pristine PS (1.4 × 108 CFU mg-1 and 1.4 × 10-8, respectively). Moreover, erythromycin at 0.1 and 1.0 mg L-1 significantly (p < 0.05) promoted the formation and resistance mutation of biofilm on both pristine and UV-aged PS. DNA sequencing results confirmed that the biofilm resistance was attributed to point mutations in rpoB segment of the bacterial genome. qPCR results demonstrated that both UV aging and erythromycin repressed the expression levels of a global regulator rpoS in biofilm bacteria, as well as two DNA mismatch repair genes mutS and uvrD, which was likely to contribute to increased resistance mutation frequency.
Subject(s)
Biofilms , Erythromycin , Escherichia coli , Microplastics , Mutation , Polystyrenes , Biofilms/drug effects , Escherichia coli/drug effects , Escherichia coli/genetics , Erythromycin/pharmacology , Microplastics/toxicity , Anti-Bacterial Agents/pharmacology , Ultraviolet Rays , Drug Resistance, Bacterial/geneticsABSTRACT
Environmental impacts associated with shale gas exploitation have been historically underestimated due to neglecting to account for the production or the release of end-of-pipe organic pollutants. Here, we assessed the environmental impacts of shale gas production in China and the United States using life cycle assessment. Through data mining, we compiled literature information on organic pollutants in flowback and produced water (FPW), followed by assessments using USEtox to evaluate end-of-pipe risks. Results were incorporated to reveal the life cycle risks associated with shale gas exploitation in both countries. China exhibited higher environmental impacts than the US during the production phase. Substantially different types of organic compounds were observed in the FPW between two countries. Human carcinogenic and ecological toxicity attributed to organics in FPW was 3 orders of magnitude higher than that during the production phase in the US. Conversely, in China, end-of-pipe organics accounted for approximately 52%, 1%, and 47% of the overall human carcinogenic, noncarcinogenic, and ecological impacts, respectively. This may be partially limited by the quantitative data available. While uncertainties exist associated with data availability, our study highlights the significance of integrating impacts from shale gas production to end-of-pipe pollution for comprehensive environmental risk assessments.
Subject(s)
Natural Gas , China , Risk Assessment , United States , Humans , Environmental MonitoringABSTRACT
Biotransformation often alters chemical toxicity, yet its impacts on risk assessment are hardly quantified due to the challenges in acquiring internal exposure-based thresholds for chemicals that are readily metabolizable. Here, we integrated toxic unit and toxicokinetics to quantitatively assess toxicity contributions and potential risk of both parent compound and transformation products (TPs) to aquatic organisms, using fipronil (FIP) as a representative toxicant. In aquatic invertebrates Chironomus dilutus and Hyalella azteca, approximately 90â¯% of FIP was transformed to fipronil sulfone (SUL). FIP and SUL exhibited similar intrinsic toxicity to these organisms, which was contrary to conventional perception that SUL was more toxic than FIP. However, biotransformation was still important in risk assessment because the TP had 10-fold slower depuration rate than FIP. The amphipod H. azteca was found to be as sensitive to FIPs as the insect C. dilutus, which was previously considered ten times more sensitive based on external thresholds. This discrepancy has led to overlooking the toxicity of FIP to H. azteca in regional risk assessments. Lastly, we predicted the lethal risk of FIPs in global surface water. When using external thresholds for prediction, FIPs in 3.4â¯% of the water samples were lethally toxic to H. azteca, and the percentage of water samples at risk increased to 14â¯% when internal thresholds were used and SUF dominated the risk. This study presents an improved method for quantifying aquatic risk of readily metabolized toxicants. Our findings underscore the urgency of considering TPs in water quality assessments, especially for sensitive species that are at risk in the environment.
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Background: Litchi (Litchi chinensis) is an important sub-tropical fruit in the horticulture market in China. Breeding for improved fruit characteristics is needed for satisfying consumer demands. Budding is a sustainable method for its propagation. During our ongoing breeding program, we observed a litchi mutant with flat leaves and sharp fruit peel cracking in comparison to the curled leaves and blunt fruit peel cracking fruits of the mother plant. Methods: To understand the possible molecular pathways involved, we performed a combined metabolome and transcriptome analysis. Results: We identified 1,060 metabolites in litchi leaves and fruits, of which 106 and 101 were differentially accumulated between the leaves and fruits, respectively. The mutant leaves were richer in carbohydrates, nucleotides, and phenolic acids, while the mother plant was rich in most of the amino acids and derivatives, flavonoids, lipids and organic acids and derivatives, and vitamins. Contrastingly, mutant fruits had higher levels of amino acids and derivatives, carbohydrates and derivatives, and organic acids and derivatives. However, the mother plant's fruits contained higher levels of flavonoids, scopoletin, amines, some amino acids and derivatives, benzamidine, carbohydrates and derivatives, and some organic acids and derivatives. The number of differentially expressed genes was consistent with the metabolome profiles. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway-enriched gene expressions showed consistent profiles as of metabolome analysis. Conclusion: These results provide the groundwork for breeding litchi for fruit and leaf traits that are useful for its taste and yield.
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Plant essential oils possess broad-spectral antimicrobial property, but the applications are impeded by their insolubility in water, extreme volatility, and strong irritation. Nanoparticle-stabilized emulsion (Pickering emulsion) gels are colloidal systems with ability to accommodate two immiscible phases in one system. The thick adsorption nanoparticle layers and the cross-linked networks in continuous phase could provide protective barriers for antibacterial oil and achieve on-demand controlled release. An emulsion hydrogel templated from gelatin nanoparticle-stabilized emulsion is one-pot constructed by conducting a tunable cross-linking process between oxidized dextran (Odex) and amikacin in the continuous phase and concomitantly trapping tea tree essential oil (TO) droplets in the three-dimensional network. The resulted emulsion hydrogel presents tunable gelation time, adequate mechanical strength, fascinating injectability, and self-healing capability. It is pH-responsiveness and presents controlled release of amikacin and TO, exhibiting a long-term bacteriostasis of 144 h. The emulsion hydrogel facilitates the outstanding wound healing efficiency in 14 days (95.2 ± 0.8 % of wound closure), accompanied with enhanced collagen deposition and angiogenic activities. The incorporation of TO into emulsion hydrogel system reduced its irritation and improved its biosafety, showing potential application in bacteria inhibition even as implants in vivo.
Subject(s)
Amikacin , Nanoparticles , Amikacin/pharmacology , Gelatin , Dextrans , Hydrogels , Emulsions , Delayed-Action Preparations/pharmacology , Drug Liberation , Anti-Bacterial Agents/pharmacology , Wound HealingABSTRACT
The exposure of aquatic organisms to pollutants often occurs concomitantly with salinity fluctuations. Here, we reported the effects of erythromycin (0.250, 7.21, and 1030 µg/L) on marine invertebrate N. succinea and its intestinal microbiome under varying salinity levels (5, 15, and 30). The salinity elicited significant effects on the growth and intestinal microbiome of N. succinea. The susceptibility of the intestinal microbiome to erythromycin increased by 8.7- and 6.2-fold at salinities of 15 and 30, respectively, compared with that at 5 salinity. Erythromycin caused oxidative stress and histological changes in N. succinea intestines, and inhibited N. succinea growth in a concentration-dependent manner under 30 salinity with a maximum inhibition of 25%. At the intestinal microbial level, erythromycin enhanced the total cell counts at 5 salinity but reduced them at 15 salinity. Under all tested salinities, erythromycin diminished the antibiotic susceptibility of the intestinal microbiome. Two-way ANOVA revealed significant interactive effects (p < 0.05) between salinity and erythromycin on various parameters, including antibiotic susceptibility and intestinal microbial diversity. The present findings demonstrated the significant role of salinity in modulating the impacts of erythromycin, emphasizing the necessity to incorporate salinity fluctuations into environmental risk assessments.