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1.
Ecotoxicol Environ Saf ; 198: 110680, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32361497

RESUMO

Salicylic acid (SA) is a crucial signal molecule and phytohormone, regulating the biotic and abiotic stress responses as well as plant development. In this research, we comparatively examined the effects of exogenous SA on the behaviors of thiamethoxam (THIM), hymexazol (HMI) and chlorantraniliprole (CAP) in cucumber planting systems under soil pot and hydroponic cultivation. The cucumber seedlings were transplanted into soil or nutrient solution containing a target pesticide (1 mg/kg) or a target pesticide with SA (1 mg/kg) after the fourth leaf emerged. We examined the behaviors of pesticides both the SA treated and nontreated plants by analyzing cucumber root, stem and leaf samples taken on the 0-21 days following the root treatment. The root concentration factor (RCF), bioconcentration factor (BCF) and translocation factors (TFstem and TFleaf) were calculated for the comparison of the differences in the behaviors of pesticides. We found that the accumulation behaviors of pesticides in planting systems were related to the physicochemical properties of pesticides, exogenous SA and cultivation methods. Exogenous SA had a certain promoting effect on the degradation of pesticides in soil and nutrient solution, resulting in reduced half-lives. SA was able to block the accumulation of pesticides in roots and leaves and alleviated the accumulation ability of roots, the bioconcentration ability of plants, and the translocation ability from roots to leaves. Interestingly, SA had more distinct effects on the behaviors of pesticides under hydroponic experiments than under soil pot experiments. Furthermore, the behaviors of clothianidin (CLO), the main metabolite of THIM, were also assessed, indicating that THIM was mainly metabolized to CLO in leaves and stems, and SA facilitated this process. Our findings suggest that SA has a certain regulatory effect on the accumulation of pesticides in plants, and SA-blocked pesticide accumulation is practically rewarding for improving food safety.

2.
Zhongguo Zhen Jiu ; 40(5): 457-61, 2020 May 12.
Artigo em Chinês | MEDLINE | ID: mdl-32394650

RESUMO

On the base of the idea of traditional Chinese medicine as "disease prevention", the mode and the protocol of the moxibustion intervention for the group under quarantine after close contact with coronavirus disease 2019 (COVID-19) were explored. The group under quarantine after close contact with COVID-19 was taken as the subjects. By the non-contact physician-patient communication network platform co-developed by China Association of Acupuncture-Moxibustion, Hunan Provincial Association of Acupuncture-Moxibustion, Data Center of China Academy of Chinese Medical Sciences and Yuge Medicine Company, an exploratory randomized controlled trial was designed. A total of 100 cases were included and randomized into a moxibustion group and a conventional intervention group, 50 cases in each one. In the moxibustion group, moxibustion intervention was used. In the conventional intervention group, the conventional observation was adopted without moxibusiton intervention applied. The outcomes included the symptoms changes, e.g. anxiety, emotional disturbance, fatigue, headache and diarrhea, as well as whether quarantine release and the case confirmed or not, etc. The results were evaluated before intervention, in 14 days of intervention and 2 weeks after intervention separately. In this research, on the base of internet plus technology and with the internet communication platform adopted, through mobile phone WeChat App, it was to implement the subject screen, the random allocation and the instruction of moxibustion intervention as well as the quality control of patient's diary and data collection. It is anticipated that the significance and the implementation mode of moxibustion intervention can be assessed preliminarily for the group under quarantine after close contact with COVID-19.


Assuntos
Terapia por Acupuntura/métodos , Betacoronavirus , Infecções por Coronavirus/terapia , Moxibustão , Pneumonia Viral/terapia , China , Humanos , Pandemias , Quarentena
3.
Science ; 368(6490): 521-526, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32355030

RESUMO

Ceramics are an important class of materials with widespread applications because of their high thermal, mechanical, and chemical stability. Computational predictions based on first principles methods can be a valuable tool in accelerating materials discovery to develop improved ceramics. It is essential to experimentally confirm the material properties of such predictions. However, materials screening rates are limited by the long processing times and the poor compositional control from volatile element loss in conventional ceramic sintering techniques. To overcome these limitations, we developed an ultrafast high-temperature sintering (UHS) process for the fabrication of ceramic materials by radiative heating under an inert atmosphere. We provide several examples of the UHS process to demonstrate its potential utility and applications, including advancements in solid-state electrolytes, multicomponent structures, and high-throughput materials screening.

4.
J Invertebr Pathol ; 174: 107394, 2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32428446

RESUMO

Heat shock protein 70 (Hsp70), a highly conserved protein family, is widely distributed in organisms and plays fundamental roles in biotic and abiotic stress responses. However, reports on Hsp70 genes are scarce in microsporidia, a very large group of obligate intracellular parasites that can infect nearly all animals, including humans. In this study, we identified 37 Hsp70 proteins from eight microsporidian genomes and classified them into four subfamilies (A-D). The number of Hsp70 genes in these microsporidia was significantly fewer than in Rozella allomycis and yeast. All microsporidian species contained genes from each subfamily and similar subcellular locations (mitochondria, endoplasmic reticulum, cytosol, and cytosol and/or nucleus), indicating that each Hsp70 member may fulfil distinct functions. The conserved structures and motifs of the Hsp70 proteins in the same subfamily were highly similar. Expression analysis indicated that the subfamily C cytosol (cyto)-associated Hsp70s is functional during microsporidia development. Immunofluorescence assays revealed that Cyto-NbHsp70 was cytoplasmically located in the proliferation-stage of Nosema bombycis. Cyto-NbHsp70 antiserum also labeled Encephalitozoon hellem within infected cells, suggesting that this antiserum is a potential molecular marker for labeling the proliferative phases of different microsporidian species. The propagation of N. bombycis was significantly inhibited following RNAi of Cyto-NbHsp70, indicating that Cyto-NbHsp70 is important for pathogen proliferation. Our phylogenetic data suggest that Hsp70 proteins evolved during microsporidia adaption to intracellular parasitism, and they play important roles in pathogen development.

5.
J Agric Food Chem ; 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32456438

RESUMO

Glucagon-like peptide-1 (GLP-1) secreted from enteroendocrine L-cells is a pleiotropic hormone with beneficial potential related to islet function, diet control, glucose homeostasis, inflammation relief and cardiovascular protection. The present study aimed at investigating the effect of Polygonatum cyrtonema polysaccharide (PCP) after structural identification on GLP-1 secretion and the possible mechanism involved in the PCP-stimulated secretion of GLP-1. It was found that GLP-1 secretion was effectively promoted (p < 0.01) by PCP both in rats with oral administration for 5 weeks (13.9 ± 0.3 pmol/L to 35.8 ± 0.3 pmol/L) and ileal administration within 2 h (13.6 ± 0.4 pmol/L to 34.1 ± 1.1 pmol/L), and in enteroendocrine NCI-H716 cells with direct stimulation within 24 h (2.05 ± 0.3 pmol/L to 20.7 ± 0.2 pmol/L). The sweet taste receptor T1R2/T1R3 was identified to be essential for NCI-H716 cells to directly recognize PCP. The intervention experiments showed that PCP-stimulated GLP-1 secretion was significantly depressed (p < 0.01) not only by antibodies, siRNA and inhibitor of T1R2/T1R3, but also by adenylate cyclase inhibitor. These results suggest that PCP stimulates GLP-1 secretion from enteroendocrine cells possibly through activation of T1R2/T1R3-mediated cAMP signaling pathway. KEYWORDS: Polygonatum cyrtonema, polysaccharide, glucagon-like peptide-1, sweet taste receptor, cAMP signaling pathway.

6.
Int J Mol Med ; 45(5): 1477-1487, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32323750

RESUMO

Sepsis­induced cardiomyopathy (SIC) is a complication of severe sepsis and septic shock characterized by an invertible myocardial depression. This study sought to explore the potential effects and mechanism of luteolin, a flavonoid polyphenolic compound, in lipopolysaccharide (LPS)­induced myocardial injury. Experimental mice were randomly allocated into 3 groups (25 mice in each group): The control group (NC), the LPS group (LPS) and the LPS + luteolin group (LPS + Lut). Before the SIC model was induced, luteolin was dissolved in DMSO and injected intraperitoneally for 10 days into LPS + Lut group mice. NC group and LPS group mice received an equal volume of DMSO for 10 days. On day 11, the animal model of sepsis­induced cardiac dysfunction was induced by intraperitoneal injection of LPS. A total of 12 h after LPS injection, measurements and comparisons were made among the groups. Luteolin administration improved cardiac function, attenuated the inflammatory response, alleviated mitochondrial injury, decreased oxidative stress, inhibited cardiac apoptosis and enhanced autophagy. In addition, luteolin significantly decreased the phosphorylation of AMP­activated protein kinase (AMPK) in septic heart tissue. The protective effect of luteolin was abolished by 3­methyladenine (an autophagy inhibitor) and dorsomorphin (compound C, an AMPK inhibitor), as evidenced by decreased autophagic activity, destabilized mitochondrial membrane potential and increased apoptosis in LPS­treated cardiomyocytes, but was mimicked by 5­aminoimidazole­4­carboxamide ribonucleotide (an AMPK activator), suggesting that luteolin attenuates LPS­induced myocardial injury by increasing autophagy through AMPK activation. Luteolin may be a promising therapeutic agent for treating SIC.

7.
Chem Commun (Camb) ; 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32347243

RESUMO

A terbium(iii) complex can recognize soluble Aß in plasma through human serum albumin (HSA)-mediated co-assembly, which can not only circumvent the interference of HSA, but also benefit Aß enrichment with amplified time-resolved luminescence enhancement.

8.
Zhongguo Yi Liao Qi Xie Za Zhi ; 44(1): 51-55, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-32343067

RESUMO

Drug-device combination product, which comprises at least a drug and a medical device, has been proved to effectively reduce the risk of complications accompanied with conventional medical devices implantation, and has a great clinical success especially in implantable therapeutics. Herein, we firstly elaborated the definitions and requirements of drug-device combination product in different countries, then summarized the market application and research development of typical drug-device combination products. Technical problems and the trend of future development had also been analyzed.

9.
EBioMedicine ; 54: 102719, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32259714

RESUMO

BACKGROUND: Disruption of bile acid (BA) homeostasis plays a key role in intestinal inflammation. The gut-liver axis is the main site for the regulation of BA synthesis and BA pool size via the combined action of the nuclear Farnesoid X Receptor (FXR) and the enterokine Fibroblast Growth Factor 19 (FGF19). Increasing evidence have linked derangement of BA metabolism with dysbiosis and mucosal inflammation. Thus, here we aimed to investigate the potential action of an FGF19 analogue on intestinal microbiota and inflammation. METHODS: A novel engineered non-tumorigenic variant of the FGF19 protein, M52-WO 2016/0168219 was generated. WT and FXRnull mice were injected with AAV-FGF19-M52 or the control AAV-GFP and subjected to Sodium Dextran Sulphate-induced colitis. FINDINGS: FGF19-M52 reduced BA synthesis and pool size, modulated its composition and protected mice from intestinal inflammation. These events were coupled with preservation of the intestinal epithelial barrier integrity, inhibition of inflammatory immune response and modulation of microbiota composition. Interestingly, FGF19-M52-driven systemic and local anti-inflammatory activity was completely abolished in Farnesoid X Receptor (FXR)null mice, thus underscoring the need of FXR to guarantee enterocytes' fitness and complement FGF19 anti-inflammatory activity. To provide a translational perspective, we also show that circulating FGF19 levels are reduced in patients with Crohn's disease. INTERPRETATION: Reactivation of the FXR-FGF19 axis in a murine model of intestinal inflammation could bona fide provide positive changes in BA metabolism with consequent reduction of intestinal inflammation and modulation of microbiota. These results point to the therapeutic potential of FGF19 in the treatment of intestinal inflammation with concomitant derangement of BA homeostasis. FUNDING: A. Moschetta is funded by MIUR-PRIN 2017 <- 2017J3E2W2; Italian Association for Cancer Research (AIRC, IG 23239); Interreg V-A Greece-Italy 2014-2020-SILVER WELLBEING, MIS5003627; HDHL-INTIMIC EuJPI-FATMAL; MIUR PON "R&I" 2014-2020-ARS01_01220. No money has been paid by NGM Biopharmaceuticals or any other agency to write this article.

11.
Med Sci Monit ; 26: e920943, 2020 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-32248202

RESUMO

BACKGROUND Bone morphogenetic proteins (BMPs) are widely involved in cancer development. However, a wealth of conflicting data raises the question of whether BMPs serve as oncogenes or as cancer suppressors. MATERIAL AND METHODS By integrating multi-omics data across cancers, we comprehensively analyzed the genomic and pharmacogenomic landscape of BMP genes across cancers. RESULTS Surprisingly, our data indicate that BMPs are globally downregulated in cancers. Further genetics and epigenetics analyses show that this abnormal expression is driven by copy number variations, especially heterozygous amplification. We next assessed the BMP-associated pathways and demonstrated that they suppress cell cycle and estrogen hormone pathways. Bone morphogenetic protein interacts with 58 compounds, and their dysfunction can induce drug sensitivity. CONCLUSIONS Our results define the landscape of the BMP family at a systems level and open potential therapeutic opportunities for cancer patients.


Assuntos
Proteínas Morfogenéticas Ósseas , Neoplasias/metabolismo , Animais , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/fisiologia , Variações do Número de Cópias de DNA , Humanos , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/fisiologia
12.
Database (Oxford) ; 20202020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294193

RESUMO

Circulating tumor cells/microemboli (CTCs/CTMs) are malignant cells that depart from cancerous lesions and shed into the bloodstream. Analysis of CTCs can allow the investigation of tumor cell biomarker expression from a non-invasive liquid biopsy. To date, high-throughput technologies have become a powerful tool to provide a genome-wide view of transcriptomic changes associated with CTCs/CTMs. These data provided us much information to understand the tumor heterogeneity, and the underlying molecular mechanism of tumor metastases. Unfortunately, these data have been deposited into various repositories, and a uniform resource for the cancer metastasis is still unavailable. To this end, we integrated previously published transcriptome datasets of CTCs/CTMs and constructed a web-accessible database. The first release of ctcRbase contains 526 CTCs/CTM samples across seven cancer types. The expression of 14 631 mRNAs and 3642 long non-coding RNAs of CTCs/CTMs were included. Experimental validations from the published literature are also included. Since CTCs/CTMs are considered to be precursors of metastases, ctcRbase also collected the expression data of primary tumors and metastases, which allows user to discover a unique 'circulating tumor cell gene signature' that is distinct from primary tumor and metastases. An easy-to-use database was constructed to query and browse CTCs/CTMs genes. ctcRbase can be freely accessible at http://www.origin-gene.cn/database/ctcRbase/.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32325156

RESUMO

The antidepressant effect of repetitive transcranial magnetic stimulation (rTMS) has been extensively studied; growing evidence suggests that changes in lipid composition may be involved in the pathogenesis of depression and may be a targeted mechanism for treatment. However, the influence of rTMS on lipid composition and the differences between these effects compared to antidepressants like fluoxetine (Flx) have never been investigated. Using a chronic unpredictable stress (CUS) model in rats, we assessed the antidepressive effects of rTMS and Flx treatments and evaluated changes in lipid composition in the hippocampus and prefrontal cortex (PFC) using a mass spectrometry-based lipidomic approach. Both rTMS and Flx treatments ameliorated depressive-like behaviors induced by CUS. Moreover, changes in lipid composition, especially glycerophospholipids, sphingolipids, and glycerolipids induced by CUS in the hippocampus were more robust than those observed in the PFC. CUS led to decreased levels of 20 carbon-containing fatty acyls and polyunsaturated fatty acyls in the PFC, and decreased levels of acyl carnitines (AcCa) in both the hippocampus and PFC. Notably, rTMS treatment had higher impact than Flx on composition of glycerophospholipids and sphingolipids in the hippocampus that were altered by CUS, while Flx attenuated CUS-induced changes in the PFC to a greater extent than rTMS. However, neither was able to restore fatty acyls and AcCa to baseline levels. Altogether, modulation of the brain lipidome may be involved in the antidepressant action of rTMS and Flx, and the degree to which these treatments induce changes in lipid composition within the hippocampus and PFC might explain their differential antidepressant effects.

14.
Sci Adv ; 6(12): eaaz0368, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32219165

RESUMO

Adhesion G protein-coupled receptor G6 (Adgrg6; also named GPR126) single-nucleotide polymorphisms are associated with human height in multiple populations. However, whether and how GPR126 regulates body height is unknown. In this study, we found that mouse body length was specifically decreased in Osx-Cre;Gpr126fl/fl mice. Deletion of Gpr126 in osteoblasts resulted in a remarkable delay in osteoblast differentiation and mineralization during embryonic bone formation. Postnatal bone formation, bone mass, and bone strength were also significantly affected in Gpr126 osteoblast deletion mice because of defects in osteoblast proliferation, differentiation, and ossification. Furthermore, type IV collagen functioned as an activating ligand of Gpr126 to regulate osteoblast differentiation and function by stimulating cAMP signaling. Moreover,the cAMP activator PTH(1-34), could partially restore the inhibition of osteoblast differentiation and the body length phenotype induced by Gpr126 deletion.Together, our results demonstrated that COLIV-Gpr126 regulated body length and bone mass through cAMP-CREB signaling pathway.

15.
Sensors (Basel) ; 20(6)2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32188067

RESUMO

Gait recognition and understanding systems have shown a wide-ranging application prospect. However, their use of unstructured data from image and video has affected their performance, e.g., they are easily influenced by multi-views, occlusion, clothes, and object carrying conditions. This paper addresses these problems using a realistic 3-dimensional (3D) human structural data and sequential pattern learning framework with top-down attention modulating mechanism based on Hierarchical Temporal Memory (HTM). First, an accurate 2-dimensional (2D) to 3D human body pose and shape semantic parameters estimation method is proposed, which exploits the advantages of an instance-level body parsing model and a virtual dressing method. Second, by using gait semantic folding, the estimated body parameters are encoded using a sparse 2D matrix to construct the structural gait semantic image. In order to achieve time-based gait recognition, an HTM Network is constructed to obtain the sequence-level gait sparse distribution representations (SL-GSDRs). A top-down attention mechanism is introduced to deal with various conditions including multi-views by refining the SL-GSDRs, according to prior knowledge. The proposed gait learning model not only aids gait recognition tasks to overcome the difficulties in real application scenarios but also provides the structured gait semantic images for visual cognition. Experimental analyses on CMU MoBo, CASIA B, TUM-IITKGP, and KY4D datasets show a significant performance gain in terms of accuracy and robustness.

16.
Carbohydr Polym ; 236: 116009, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32172837

RESUMO

In this study, whey protein isolate (WPI)-quercetin (Que)-lotus root amylopectin (LRA) hydrogels (WPI-QUE-LRA) was developed to improve the solubility, stability and bioavailability of quercetin. Results showed that the favorable WPI-QUE-LRA was formed using WPI and LRA in the ratio of 1:2 at pH 7.0. Under this condition, the average size, polydispersity index, zeta potential of the WPI-QUE-LRA was 179.5 nm, 0.271, -18.6 mV, respectively. The analysis of transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffractometer revealed that the quercetin was successfully encapsulated in WPI-LRA, giving a high encapsulation efficiency of 92.4 %. Moreover, the WPI-LRA could significantly improve the storage stability and photochemical stability of quercetin. The in vitro and in vivo experiments showed that LRA-coated WPI hydrogel can enable quercetin to be stable in stomach and be effectively released in small intestine, leading to the enhancement of the bioavailability of quercetin.

18.
mSphere ; 5(1)2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051240

RESUMO

Microsporidia are obligate intracellular parasites that infect a wide variety of host organisms, including humans. The sporoplasm is the initial stage of microsporidian infection and proliferation, but its morphological and molecular characteristics are poorly understood. In this study, the sporoplasm of Nosema bombycis was successfully isolated and characterized after the induction of spore germination in vitro The sporoplasm was spherical, 3.64 ± 0.41 µm in diameter, had the typical two nuclei, and was nonrefractive. Scanning and transmission electron microscopy analyses revealed that the sporoplasm was surrounded by a single membrane, and the cytoplasm was usually filled with relatively homogeneous granules, possibly ribosomes, and contained a vesicular structure comprising a concentric ring and coiled tubules. Propidium iodide staining revealed that the sporoplasm membrane showed stronger membrane permeability than did the cell plasma membrane. Transmission electron microscopy (TEM) revealed that the sporoplasm can gain entry to the host cell by phagocytosis. Transcriptome analysis of mature spores and sporoplasms showed that 541 significantly differentially expressed genes were screened (adjusted P value [P adj] < 0.05), of which 302 genes were upregulated and 239 genes were downregulated in the sporoplasm. The majority of the genes involved in trehalose synthesis metabolism, glycolysis, and the pentose phosphate pathway were downregulated, whereas 10 transporter genes were upregulated, suggesting that the sporoplasm may inhibit its own carbon metabolic activity and obtain the substances required for proliferation through transporter proteins. This study represents the first comprehensive and in-depth investigation of the sporoplasm at the morphological and molecular levels and provides novel insights into the biology of microsporidia and their infection mechanism.IMPORTANCE Once awoken from dormancy, the cellular matter of microsporidia is delivered directly into the host cell cytoplasm through the polar tube. This means that the microsporidia are difficult to study biologically in their active state without a contaminating signal from the host cell. Sporoplasm is a cell type of microsporidia in vitro, but relatively little attention has been paid to the sporoplasm in the past 150 years due to a lack of an effective separation method. Nosema bombycis, the first reported microsporidium, is a type of obligate intracellular parasite that infects silkworms and can be induced to germinate in alkaline solution in vitro We successfully separated the N. bombycis sporoplasm in vitro, and the morphological and structural characteristics were investigated. These results provide important insight into the biology and pathogenesis of microsporidia and potentially provide a possible strategy for genetic manipulation of microsporidia targeting the sporoplasm.

19.
Chem Commun (Camb) ; 56(22): 3329-3332, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32083260

RESUMO

Taxodisones A and B, C30-terpenes with an unprecedented tetracyclo[12.4.0.0.2,709,14]octodecane core, were isolated from the seeds of Taxodium distichum. Their structures, including their configurations, were unambiguously determined. Their biomimetic synthesis suggests that they stem from diterpenes and monoterpenes, and not from squalene or oxidosqualene. In addition, their bioactivities were also evaluated.

20.
Sci Total Environ ; 718: 137309, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32087590

RESUMO

Light non-aqueous phase liquid (LNAPL) contaminated sites pose a risk to human health and the natural environment. Multi-phase extraction (MPE) is one of the most widely used technologies to remediate these sites. Thus, it is important to optimize MPE systems to improve their effectiveness and cost-efficiency. In this study, we developed a numerical model to optimize LNAPL mass removal by MPE, in which the aquifer domain was simplified as a cylinder with a single MPE extraction well located at the center. A dual-pump extraction system was applied to the model, which involved vacuum enhanced recovery to remove volatilized gaseous phase contaminants and a submerged pump to remove NAPL and contaminants in groundwater. After the model was validated with field data, the results showed that the contaminant extraction rate varied with the LNAPL thickness and submerged pump position. For benzene selected as the contaminant of concern, greater LNAPL extraction rates were achieved when the initial LNAPL thickness was large (>1.5 m) or in aquifers of high permeability (>2.45 × 10-10 m2). Importantly, it was discovered that in highly permeable coarse sand and gravel, the submerged pump ought to be placed within the LNAPL layer, whereas the pump should be placed below the water-NAPL interface in fine to medium sand aquifers. It was also found that an optimal liquid pumping rates exist, beyond which contaminant mass removal rates do not increase. Furthermore, it was found that in aquifers contaminated with thin LNAPL layers, mass transfer modelling that assumes equilibrium between the phases may greatly overestimate the accumulated mass of contaminants removed and, therefore, non-equilibrium modelling should be adopted. Finally, a cost analysis was carried out to compare the costs of remediating a contaminated site with MPE and by an alternative chemical oxidation approach. The MPE technology was found to be more cost effective when the initial thickness of LNAPL was relatively thin. In summary, the numerical model developed in this study is a useful tool for optimizing MPE system design.

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