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1.
J Hazard Mater ; 422: 126884, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34416693

RESUMO

Fluoroquinolones in aquatic environments have caused worldwide concern due to the negative effects on human health and ecological environment. So far, the performance and mechanism for fluoroquinolones removal by the synergistic activation of peroxymonosulfate (PMS) via vacuum UV (VUV) irradiation and Fe2+ are still blank. Herein, compared with its sub-processes, VUV/Fe2+/PMS process significantly improved the degradation and mineralization efficiencies of three fluoroquinolones. Effect mechanisms of typical parameters (Fe2+ and PMS doses, initial pH) on norfloxacin (NOR) removal by VUV/Fe2+/PMS were elaborated and VUV/Fe2+/PMS showed excellent performance at wide initial pH (3-10). The results of fluorescence molecular probe and radical trapping experiments proved that hydroxyl radical, singlet oxygen, and sulfate radical were primary reactive oxygen species in VUV/Fe2+/PMS. The degradation pathways of NOR in VUV/Fe2+/PMS were mainly defluorination, piperazine ring transformation and quinolone group transformation, and its main inorganic by-products were F-, NO3-, and NH4+. Besides, the synergistic reaction pathways in integrated VUV/Fe2+/PMS process were elaborated. Furthermore, inorganic anions (such as Cl-, NO3-, SO42-, CO32-) hardly affected NOR removal by VUV/Fe2+/PMS, while dissolved organic matter showed slight inhibition. Finally, well-pleasing results of fluoroquinolones removal by VUV/Fe2+/PMS in actual waters highlighted its superiority in the advanced treatment of secondary effluent.


Assuntos
Ferro , Poluentes Químicos da Água , Fluoroquinolonas , Oxirredução , Peróxidos , Vácuo , Poluentes Químicos da Água/análise
2.
Int J Gen Med ; 14: 9671-9679, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34934344

RESUMO

Aim: The aim of the present study was to identify the association between tumor grade and liquid-liquid phase separation (LLPS)-related genes, and to generate a LLPS-related gene-based risk index (LLPSRI) as a prognostic tool for hepatocellular carcinoma (HCC). Methods: Weighted gene correlation network analysis was performed to test whether the LLPS-related gene modules were associated with tumor grade of HCC. The candidate modules were subjected to functional enrichment analysis. We generated a LLPSRI using the expression profiles of the hub genes among the candidate modules in order to identify patients at high risk. Then, the biological characteristics of the high-risk patients were revealed using gene set enrichment analysis. Additionally, an independent external data set was used to validate the LLPSRI. Results: Four gene modules showed a significant positive correlation with tumor grade and involved various cancer-related pathways. Among the hub genes, six were selected to generate the LLPSRI, which was significantly associated with prognosis of HCC patients. The LLPSRI could successfully divide patients with HCC into high- and low-risk groups, and patients in the high-risk group showed shorter overall survival than those in the low-risk group. E2F, MYC, and mTORC1 signaling may be important determinants of survival in the high-risk group. The prognostic value of the LLPSRI was validated with the independent external data set. Conclusion: We identified LLPS-related gene modules that are associated with HCC tumor grade. The LLPSRI may be useful as a prognostic marker of HCC, and it may reliably stratify patients into groups at low or high risk of worse survival. Our analysis also suggests that certain biological characteristics of HCC may be associated with high risk of worse survival.

3.
4.
Sci Total Environ ; 798: 149071, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34315057

RESUMO

N-nitrosodimethylamine (NDMA), a nitrosamine, is a typical nitrogenous disinfection byproduct. In this study, NDMA formation potential and mechanism, from tetracycline and oxytetracycline (as model precursors) in an ammonium-contaminating water, were investigated. The results indicated that both monochloramine and dichloramine played a vital role in NDMA formation. Additionally, the determination of NDMA formation potential (NDMA FP) at a wide range of pH showed that the unprotonated tetracycline tended to have a higher NDMA conversion ratio. We also found that the dissociation of hydroxyl on the meta-position of dimethylamine group promoted on NDMA formation. The detection of significant intermediate products showed that N-chloro unsymmetrical dimethylhydrazine (UDMH-Cl) and sequences of chlorine substitution products were key intermediates, indicating that NDMA formation occurred via the UDMH mechanism pathway. These results improve the knowledge on NDMA formation mechanism and the control strategies during the disinfection of ammonium-containing water.


Assuntos
Compostos de Amônio , Poluentes Químicos da Água , Purificação da Água , Antibacterianos , Cloro , Dimetilnitrosamina , Desinfecção , Tetraciclinas , Água , Poluentes Químicos da Água/análise
5.
Biomed Res Int ; 2021: 8836243, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34124262

RESUMO

Severe burns are acute wounds caused by local heat exposure, resulting in life-threatening systemic effects and poor survival. However, the specific molecular mechanisms remain unclear. First, we downloaded gene expression data related to severe burns from the GEO database (GSE19743, GSE37069, and GSE77791). Then, a gene expression analysis was performed to identify differentially expressed genes (DEGs) and construct protein-protein interaction (PPI) network. The molecular mechanism was identified by enrichment analysis and Gene Set Enrichment Analysis. In addition, STEM software was used to screen for genes persistently expressed during response to severe burns, and receiver operating characteristic (ROC) curve was used to identify key DEGs. A total of 2631 upregulated and 3451 downregulated DEGs were identified. PPI network analysis clustered these DEGs into 13 modules. Importantly, module genes mostly related with immune responses and metabolism. In addition, we identified genes persistently altered during the response to severe burns corresponding to survival and death status. Among the genes with high area under the ROC curve in the PPI network gene, CCL5 and LCK were identified as key DEGs, which may affect the prognosis of burn patients. Gene set variation analysis showed that the immune response was inhibited and several types of immune cells were decreased, while the metabolic response was enhanced. The results showed that persistent gene expression changes occur in response to severe burns, which may underlie chronic alterations in physiological pathways. Identifying the key altered genes may reveal potential therapeutic targets for mitigating the effects of severe burns.


Assuntos
Queimaduras , Bases de Dados de Ácidos Nucleicos , Perfilação da Expressão Gênica , Redes Reguladoras de Genes/imunologia , Mapas de Interação de Proteínas/imunologia , Transcriptoma/imunologia , Queimaduras/genética , Queimaduras/imunologia , Queimaduras/patologia , Biologia Computacional , Humanos , Índices de Gravidade do Trauma
6.
Chem Commun (Camb) ; 57(33): 3999-4002, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33885695

RESUMO

A 72-nuclearity niobium cluster was synthesized, in which two {CuNb26O76} clusters and one {Nb20O59} cluster are fused in a triangular fashion, resulting in a {Nb12} cavity. Further, the simple nature of the species allowed its investigation by ESI-MS analysis, yielding two subunits with time.

7.
Front Oncol ; 11: 569295, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33747905

RESUMO

Resveratrol (RSV) is known to possess anticancer properties in many types of cancers like breast cancer, in which POLD1 may serve as a potential target. However, the anticancer mechanism of RSV on triple negative breast cancer (TNBC) remains unclear. In the present study, the antitumor effects and mechanism of RSV on TNBC cells were analyzed by RNA sequencing (RNA-seq), which was then verified via cell counting kit-8 (CCK8), immunofluorescence, immunohistochemistry, Western Blot (WB), flow cytometry, and hematoxylin-eosin (HE) staining. According to the corresponding findings, the survival rate of MDA-MB-231 cells gradually decreased as RSV treatment concentration increased. The RNA-seq analysis results demonstrated that genes affected by RSV treatment were mainly involved in apoptosis and the p53 signaling pathway. Moreover, apoptosis of MDA-MB-231 cells induced by RSV was observed to be mainly mediated by POLD1. When treated with RSV, the expression levels of full length PARP1, PCNA, and BCL-2 were found to be significantly reduced, and the expression level of Cleaved-PARP1 as well as Cleaved-Caspase3 increased significantly. Additionally, the mRNA expression of POLD1 was significantly reduced after treatment with RSV, and the protein expression level was also inhibited by RSV in a concentration-dependent manner. The prediction of domain interaction suggested that RSV may bind to at least five functional domains of the POLD1 protein (6s1m, 6s1n, 6s1o, 6tny and 6tnz). Furthermore, after RSV treatment, the anti-apoptotic index (PCNA, BCL-2) of MDA-MB-231 cells was found to decrease while the apoptosis index (caspase3) increased. Moreover, the overexpression of POLD1 reduced the extent of apoptosis observed in MDA-MB-231 cells following RSV treatment. Moreover, animal experimental results showed that RSV had a significant inhibitory effect on the growth of live tumors, while POLD1 overexpression was shown to antagonize this inhibitory effect. Accordingly, this study's findings reveal that RSV may promote the apoptosis of TNBC cells by reducing the expression of POLD1 to activate the apoptotic pathway, which may serve as a potential therapy for the treatment of TNBC.

8.
Int J Mass Spectrom ; 4622021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33642939

RESUMO

Native capillary zone electrophoresis-mass spectrometry (CZE-MS) has attracted attentions for the characterization of monoclonal antibodies (mAbs) due to the potential of CZE for highly efficient separations of mAbs under native conditions as well as its compatibility with native electrospray ionization (ESI)-MS. However, the low sample loading capacity and limited separation resolution of native CZE for large proteins and protein complexes (e.g. mAbs) impede the widespread adoption of native CZE-MS. Here, we present a novel native capillary isoelectric focusing (cIEF)-assisted CZE-MS method for the characterization of mAbs with much larger sample loading capacity and significantly better separation resolution than native CZE-MS alone. The native cIEF-assisted CZE-MS employed separation capillaries with a new carbohydrate-based neutral coating, a commercilized electrokinetically pumped sheathflow CE-MS interface, and a high-end quadrupole-time-of-flight (Q-TOF) mass spectrometer. Using the method, we documented the separations of different proteoforms of the SigmaMAb and the detection of its various glyco-proteoforms and homodimer. The native cIEF-assisted CZE-MS separated the NIST mAb into three peaks with a submicroliter sample loading volume, corresponding to its different proteoforms. We observed that both the NIST mAb and its homodimer had eight glyco-proteoforms, four of which had low abundance. The results demonstrate the potential of our native cIEF-assisted CZE-MS method for advancing the characterization of large proteins and protein complexes under native conditions.

9.
Tissue Cell ; 71: 101506, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33607525

RESUMO

Advanced platelet-rich fibrin (A-PRF) is an autogenous biological material obtained from peripheral blood. A-PRF extract (A-PRFe) contains a high concentration of various cytokines that are increasingly appreciated for their roles in improving stem cell repairing function during tissue regeneration. However, the optimal A-PRFe concentration to stimulate stem cells is unknown. This study aimed to identify the optimal concentrations of A-PRFe to promote adipogenic and osteogenic differentiation of human adipose-derived stem cells (ASCs). We produced A-PRFe from A-PRF clots by centrifuging fresh peripheral blood samples and isolated and identified ASCs using surface CD markers and multilineage differentiation potential. Enzyme-linked immunosorbent assay (ELISA) showed the concentrations of several cytokines, including b-FGF, PDGF-BB, and others, increased gradually, peaked on day 7 and then decreased. Cell proliferation assays showed A-PRFe significantly stimulated ASC proliferation, and proliferation significantly increased at higher A-PRFe doses. The degree of adipogenic and osteogenic differentiation increased at higher A-PRFe concentrations in the culture medium, as determined by oil red O and alizarin red staining. Reverse transcription polymerase chain reaction (RT-PCR) showed that expression levels of genes related to adipogenic/osteogenic differentiation (PPARγ2, C/EBPα, FABP4, Adiponectin, and ALP, OPN, OCN, RUNX2), paracrine (HIF-1α, VEGF, IGF-2) and immunoregulation (HSP70, IL-8) function were higher in groups with a higher concentration of A-PRFe than in lower concentration groups. This study demonstrates that A-PRFe is ideal for use in ASC applications in regenerative medicine because it improves biological functions, including proliferation, adipogenic/osteogenic differentiation, and paracrine function in a dose-dependent manner.

10.
Drug Des Devel Ther ; 15: 125-140, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33469265

RESUMO

Background: As a natural compound extracted from a variety of hot peppers, capsaicin has drawn increasing attention to its anti-cancer effects against multiple human cancers including breast cancer. FBI-1 is a major proto-oncogene negatively regulating the transcription of many tumor suppressor genes, and plays a vital role in tumorigenesis and progression. However, whether FBI-1 is involved in capsaicin-induced breast cancer suppression has yet to be ascertained. This study aimed to investigate the effects of capsaicin on proliferation and apoptosis and its association with FBI-1 expression in breast cancer. Methods: CCK-8 and morphological observation assay were employed to detect cell proliferation. Flow cytometry and TUNEL assay were conducted to detect cell apoptosis. RNA interference technique was used to overexpress or silence FBI-1 expression. qRT-PCR and/or Western blot analysis were applied to detect the protein expression of FBI-1, Ki-67, Bcl-2, Bax, cleaved-Caspase 3, Survivin and NF-κB p65. Xenograft model in nude mice was established to assess the in vivo effects. Results: Capsaicin significantly inhibited proliferation and induced apoptosis in breast cancer in vitro and in vivo, along with decreased FBI-1, Ki-67, Bcl-2 and Survivin protein expression, increased Bax protein expression and activated Caspase 3. Furthermore, FBI-1 overexpression obviously attenuated the capsaicin-induced anti-proliferation and pro-apoptosis effect, accompanied with the above-mentioned proteins reversed, whereas FBI-1 silencing generated exactly the opposite response. In addition, as a target gene of FBI-1, NF-κB was inactivated by p65 nuclear translocation suppressed with capsaicin treatment, which was perceptibly weakened with FBI-1 overexpression or enhanced with FBI-1 silencing. Conclusion: This study reveals that FBI-1 is closely involved in capsaicin-induced anti-proliferation and pro-apoptosis of breast cancer. The underlying mechanism may be related to down-regulation of FBI-1-mediated NF-κB pathway. Targeting FBI-1 with capsaicin may be a promising therapeutic strategy in patients with breast cancer.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Capsaicina/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Fatores de Transcrição/antagonistas & inibidores , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/metabolismo , Neoplasias Mamárias Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas
11.
Aging (Albany NY) ; 12(21): 21186-21201, 2020 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-33130636

RESUMO

Adipose-derived mesenchymal stem cells (ADSCs) are pluripotent stromal cells that can differentiate into a variety of cell types, including skin cells. High-throughput sequencing was performed on cells of different ages and cell passage, obtaining their methylation, mRNA expression, and protein profile data. The stemness of each sample was then calculated using the TCGAbiolinks package in R. Co-expression modules were identified using WGCNA, and a crosstalk analysis was performed on the corresponding modules. The ClusterProfile package was used for the functional annotation of module genes. Finally, the regulatory network diagram was visualized using the Cytoscape software. First, a total of 16 modules were identified, where 3 modules were screened that were most relevant to the phenotype. 29 genes were screened in combination of the RNA seq, DNA methylation seq and protein iTRAQ. Finally, a comprehensive landscape comprised of RNA expression, DNA methylation and protein profiles of age relevant ADSCs was constructed. Overall, the different omics of ADSCs were comprehensively analyzed in order to reveal mechanisms pertaining to their growth and development. The effects of age, cell passage, and stemness on the therapeutic effect of ADSCs were explored. Additionally, a theoretical basis for selecting appropriate ADSC donors for regenerative medicine was provided.


Assuntos
Envelhecimento/metabolismo , Metilação de DNA , Regulação da Expressão Gênica , Células-Tronco Mesenquimais/metabolismo , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Proteoma/metabolismo , Transcriptoma , Adulto Jovem
12.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 34(10): 1305-1312, 2020 Oct 15.
Artigo em Chinês | MEDLINE | ID: mdl-33063498

RESUMO

Objective: To explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection. Methods: rADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs. Results: The cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs ( P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D ( P<0.05). Conclusion: SDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.


Assuntos
Adipócitos , Quimiocina CXCL12 , Animais , Ratos , Ratos Sprague-Dawley , Células-Tronco , Células Estromais
13.
Aging (Albany NY) ; 12(14): 14830-14848, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32706337

RESUMO

In this study, human adipose stem cells were isolated from subcutaneous fat in the thigh (htASCs), abdomen (haASCs) and breast (hbASCs). Flow cytometry was used to detect cell surface markers, and an enzyme-linked immunosorbent assay was used to detect paracrine activity. Paracrine gene expression in the three cell types was examined using real-time qPCR, and adipogenic ability was assessed using Oil Red O staining. RNA from third-passage haASCs and hbASCs was sequenced. The results showed that the differentiation potential marker markers CD49d and CD54 were similar across hbASCs from 10 subjects. The hbASCs showed higher colony forming ability and expression of fibroblast growth factor-2, tissue inhibitor of metalloproteinase-1 and stromal cell derived factor-1 than htASCs and haASCs. Stimulating hbASCs with FGF2 promoted adipogenic differentiation, while treating the cells with the PI3K inhibitor LY294002 inhibited differentiation. These results suggest that the PI3K/Akt signaling pathway can promote proliferation and adipogenic differentiation of adipose stem cells, and that activation of this pathway by FGF2 may explain why hbASCs show greater proliferation and adipogenic differentiation than haASCs and htASCs.


Assuntos
Adipogenia/fisiologia , Diferenciação Celular/fisiologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Comunicação Parácrina/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Abdome/patologia , Adipócitos/metabolismo , Mama/patologia , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Gordura Subcutânea/citologia , Gordura Subcutânea/metabolismo , Coxa da Perna/patologia
14.
Stem Cell Res Ther ; 11(1): 310, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32698873

RESUMO

BACKGROUND: Adipose-derived mesenchymal stem cells (AD-MSCs) are a type of stem cell that is abundant and widely used. The molecular characteristics of AD-MSCs from different passages from donors of different ages have not been well elucidated. METHODS: Six kinds of AD-MSCs ((E1, E2, E3, Y1, Y2, and Y3) with E denoting cells derived from an elderly patient, Y denoting cells derived from a young patient, and 1, 2, and 3 representing passages 3, 6, and 10) were obtained from human abdominal adipose tissue. We obtained the protein expression profile, the mRNA expression profile, the lncRNA expression profile, and the methylation profile of each kind of AD-MSC by sequencing. After calculating the stemness indices, genes related to stemness were extracted. The multiomics correlation analysis was performed in the stemness-related genes. In addition, short time-series expression miner (STEM) analysis was performed for all cell passages and donor ages. To further explore the biological functions of the stemness-related genes, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Finally, the lncRNA-KEGG network and transcription factor (TF)-KEGG network were constructed based on the RNAInter database and TRRUST v2 database. RESULTS: The stemness of the Y1, E1, and Y2 cells was higher than that of the E2, Y3, and E3 cells. The stemness was the highest for Y1 cells and the lowest for E3 cells. STEM analysis showed that five stemness-related gene clusters were associated with the cell passages, and only one gene cluster was associated with age. The enrichment analysis results showed that the biological processes (BPs) and KEGG pathways were mainly involved in the proliferation, differentiation, and migration of cells. The global regulatory landscape of AD-MSCs was constructed: 25 TFs and 16 lncRNAs regulated 21 KEGG pathways through 27 mRNAs. Furthermore, we obtained a core stemness-related gene set consisting of ITGAV, MAD2L1, and PCNA. These genes were expressed at higher levels in Y1 cells than in E3 cells. CONCLUSION: The multiomics global landscape of stemness-related gene clusters was determined for AD-MSCs, which may be helpful for selecting AD-MSCs with increased stemness.


Assuntos
Células-Tronco Mesenquimais , RNA Longo não Codificante , Tecido Adiposo , Idoso , Diferenciação Celular , Células Cultivadas , Humanos , Família Multigênica
15.
Inorg Chem ; 59(12): 7895-7899, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32496063

RESUMO

A new organic-inorganic hybrid heteropolyoxoniobate, [{Cu(en)(H2O)4}{Cu(en)2(H2O)}{Cu(en)2(H2O)2}]1.5[H8SiTe8Nb15O64]·6H2O (1; en = ethanediamine), has been successfully synthesized by a conventional method. The compound was directed by pairs of [TeO3]2-/[SiO3]2- ions, generating two novel {TeNb9} and {SiTeNb6} subunits in situ owing to the mixed heteroanion. In addition, the solution behavior of compound 1 was investigated.

16.
Chemosphere ; 258: 127265, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32540534

RESUMO

Ferrate (Fe(VI)) is usually effective for oxidizing a variety of organic pollutants within a few seconds, but some recalcitrant asorganophosphorus pesticides such as dimethoate require higher dose of Fe(VI) and inorganic phosphorus produced by mineralization is difficult to remove. In this study, acid-activated ferrate (Fe(VI)) was firstly used to degrade organophosphorus pesticides dimethoate and simultaneously remove total phosphorus (TP) from solution under simulated sunlight. At a Fe(VI):dimethoate molar radio of 15:1, dimethoate was almost completely removed within 20 min and 47% of TP in the solution was removed by the reduction product of Fe(VI) within 240 min. Electron paramagnetic resonance (EPR) and terephthalic acid (TA) fluorescence experiments showed that •OH radicals were continuously generated in the system, and •OH formation pathway was proposed. Importantly, the involvement of •OH in acid-activated Fe(VI) process was confirmed for the first time by EPR. In the acid-activated Fe(VI)/simulated sunlight system, the removal of dimethoate and TP gradually increased with the decrement of activation pH, whereas the increase of molar ratio of Fe(VI):dimethoate enhanced the removal of dimethoate and TP. The addition of inorganic anions (HCO3- and NO2-) had obvious inhibitory effects on dimethoate and TP removal. Eight degradation products including O,O,S-trimethylphosphorothiate, omethoate and 2-S-methyl-(N-methyl) acetamide were determined by gas chromatography mass spectrometry (GC-MS) analysis, and two possible degradation pathways were proposed. The insights gained from this study open a new avenue to simultaneously degrade and remove organic contaminants.


Assuntos
Dimetoato/análise , Ferro/química , Praguicidas/análise , Ácidos Ftálicos/química , Luz Solar , Poluentes Químicos da Água/análise , Ferro/efeitos da radiação , Modelos Teóricos , Oxirredução , Purificação da Água/métodos
17.
J Colloid Interface Sci ; 573: 21-30, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32268260

RESUMO

The treatment of organic pigments has gained significant attention worldwide owing to the large amounts of pollutants emitted during the process. The main purpose of this study is to prepare an environmentally friendly, low-cost adsorbent with high efficiency with selective adsorption for water purification. An inorganically modified mesoporous biochar derived from sorghum straw was synthesized in one step, and three typical organic pigments including methyl blue (MB), acid orange 7 (AO7), and alizarin red (AR) were selected as cationic, azo, and anionic pigments, respectively. The characterization results demonstrated that Fe3O4 particles successfully attached to the surface of biochar after modification. Although the enhanced adsorption behaviors of the three pigments on the modified biochar were described effectively by the Langmuir isotherm, the as-prepared materials showed a better selective adsorption effect on the cationic pigments. Moreover, the adsorption processes of all targeted pigments were endothermic and governed by entropy. Smaller molecular dimensions, lighter molecular weight, and the low molecular electrostatic potential of MB are responsible for its selective adsorption; however, the enhanced adsorption affinity is attributed to the hydrogen bond and n-π interaction with the benzene ring of the pigment molecules.


Assuntos
Antraquinonas/química , Compostos Azo/química , Benzenossulfonatos/química , Corantes/química , Compostos Férricos/química , Adsorção , Estrutura Molecular , Tamanho da Partícula , Porosidade , Propriedades de Superfície
18.
Chemosphere ; 242: 125233, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896207

RESUMO

Acid/base/oxidant pretreatment influenced subsequent quaternary ammonium epoxide compounds modified carbon (QAE-AC) and hence PFOA and nitrate removal. This work discerned that the most favorable QAE-AC protocol for PFOA removal was achieved when the wood carbon pretreated with HNO3 to adjust the carbon's slurry pH to 4.77, and tailored with the QUAB188. For nitrate removal, the most favorable when the carbon was pretreated with NaOH to raise the carbon's slurry pH to 9.34, and then loaded with the QUAB360. Based on experimentally results and molecular model, we found that pore volume, phenolic groups and the surface charge were the main factors affecting the PFOA removal, while the only factor affecting nitrate removal was surface charge. The QUAB's epoxide functionalities have cross-linked with phenolics along the activated carbon's graphene edge sites. QAE is preferentially reacted with the phenolic in the micropores and mesopores of carbon, and some QAE molecules form new "pore-like structures" outside the pores with the graphene planes or other QAE molecules. This pore-like structure hosted adsorption capacity by the quaternary ammonium. The favorable PFOA adsorption sites were in smaller mesopores via both hydrophobic interaction and electrostatic interaction; and nitrate sorption was occurring in the smaller micropores via anion exchange. Therefore, it can be considered that QAE-AC can simultaneously adsorb PFOA and nitrate in water.


Assuntos
Caprilatos/química , Fluorcarbonetos/química , Modelos Químicos , Nitratos/química , Compostos de Amônio Quaternário/química , Poluentes Químicos da Água/química , Adsorção , Compostos de Amônio/química , Ânions , Carvão Vegetal/química , Compostos de Epóxi , Oxidantes , Água
19.
Angew Chem Int Ed Engl ; 59(43): 18943-18947, 2020 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-33448568

RESUMO

Efforts to synthesize degradable polymers from renewable resources are deterred by technical and economic challenges; especially, the conversion of natural building blocks into polymerizable monomers is inefficient, requiring multistep synthesis and chromatographic purification. Herein we report a chemoenzymatic process to address these challenges. An enzymatic reaction system was designed that allows for regioselective functional group transformation, efficiently converting glucose into a polymerizable monomer in quantitative yield, thus removing the need for chromatographic purification. With this key success, we further designed a continuous, three-step process, which enabled the synthesis of a sugar polymer, sugar poly(orthoester), directly from glucose in high yield (73 % from glucose). This work may provide a proof-of-concept in developing technically and economically viable approaches to address the many issues associated with current petroleum-based polymers.

20.
Dalton Trans ; 48(45): 16857-16860, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31702746

RESUMO

A novel tungstophosphate H12Na4K3[{Fe5O5(OH)2(OAc)2}2{W2-O2(OH)}{P2W14O54}2]·36H2O (1) containing an unprecedented [{Fe5O5(OH)2(OAc)2}2{W2O2(OH)}] unit has been successfully obtained and characterized by IR, TGA, magnetic susceptibility measurements and single-crystal X-ray diffraction. It shows a decameric FeIII molecular assembly formed through two {Fe5O23} subunits bridged by a {W2O3} motif.

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