Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 30
Filtrer
Plus de filtres











Base de données
Gamme d'année
1.
Small ; : e2404310, 2024 Sep 10.
Article de Anglais | MEDLINE | ID: mdl-39252649

RÉSUMÉ

Azobenzene (azo)-based photothermal energy storage systems have garnered great interest for their potential in solar energy conversion and storage but suffer from limitations including rely on solvents and specific wavelengths for charging process, short storage lifetime, low heat release temperature during discharging, strong rigidity and poor wearability. To address these issues, an azo-based fabric composed of tetra-ortho-fluorinated photo-liquefiable azobenzene monomer and polyacrylonitrile fabric template is fabricated using electrospinning. This fabric excels in efficient photo-charging (green light) and discharging (blue light) under visible light range, solvent-free operation, long-term energy storage (706 days), and good capacity of releasing high-temperature heat (80-95 °C) at room temperature and cold environments. In addition, the fabric maintains high flexibility without evident loss of energy-storage performance upon 1500 bending cycles, 18-h washing or 6-h soaking. The generated heat from charged fabric is facilitated by the Z-to-E isomerization energy, phase transition latent heat, and the photothermal effect of 420 nm light irradiation. Meanwhile, the temperature of heat release can be personalized for thermal management by adjusting the light intensity. It is applicable for room-temperature thermal therapy and can provide heat to the body in cold environments, that presenting a promising candidate for wearable personal thermal management.

2.
Biochem Biophys Res Commun ; 732: 150399, 2024 Nov 05.
Article de Anglais | MEDLINE | ID: mdl-39033551

RÉSUMÉ

The imbalance of vascular endothelial cell homeostasis is the key mechanism for the progression of many vascular diseases. RNA modification, particularly N6-Methyladenosine (m6A), plays important function in numerous biological processes. Nevertheless, the regulatory function of m6A RNA methylation in endothelial dysfunction remains insufficiently characterized. In this study, we established that the m6A methyltransferase METTL3 is critical for regulating endothelial function. Functionally, depletion of METTL3 results in decreased endothelial cells proliferation, survival and inflammatory response. Conversely, overexpression of METTL3 elicited the opposite effects. Mechanistically, MeRIP-seq identified that METTL3 catalyzed m6A modification of TRAF1 mRNA and enhanced TRAF1 translation, thereby up-regulation of TRAF1 protein. Over-expression of TRAF1 successfully rescued the inhibition of proliferation and adhesion of endothelial cells due to METTL3 knockdown. Additionally, m6A methylation-mediated TRAF1 expression can be reversed by the demethylase ALKBH5. Knockdown of ALKBH5 upregulated the level of m6A and protein level of TRAF1, and also increased endothelial cells adhesion and inflammatory response. Collectively, our findings suggest that METTL3 regulates vascular endothelium homeostasis through TRAF1 m6A modification, suggesting that targeting the METTL3-m6A-TRAF1 axis may hold therapeutic potential for patients with vascular diseases.


Sujet(s)
Adénosine , Prolifération cellulaire , Cellules endothéliales de la veine ombilicale humaine , Inflammation , Methyltransferases , Facteur-1 associé aux récepteurs de TNF , Methyltransferases/métabolisme , Methyltransferases/génétique , Humains , Méthylation , Inflammation/métabolisme , Inflammation/génétique , Inflammation/anatomopathologie , Facteur-1 associé aux récepteurs de TNF/métabolisme , Facteur-1 associé aux récepteurs de TNF/génétique , Adénosine/analogues et dérivés , Adénosine/métabolisme , Cellules endothéliales de la veine ombilicale humaine/métabolisme , Cellules endothéliales/métabolisme , AlkB Homolog 5, RNA demethylase/métabolisme , AlkB Homolog 5, RNA demethylase/génétique ,
3.
Environ Sci Technol ; 58(28): 12532-12541, 2024 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-38940696

RÉSUMÉ

While partial nitrification (PN) has the potential to reduce energy for aeration, it has proven to be unstable when treating low-strength wastewater. This study introduces an innovative combined strategy incorporating a low rate of oxygen supply, pH control, and sulfide addition to selectively inhibit nitrite-oxidizing bacteria (NOB). This strategy led to a stable PN in a laboratory-scale membrane aerated biofilm reactor (MABR). Over a period of 260 days, the nitrite accumulation ratio exceeded 60% when treating synthetic sewage containing 50 mg NH4+-N/L. Through in situ activity testing and high-throughput sequencing, the combined strategy led to low levels of nitrite-oxidation activity (<5.5 mg N/m2 h), Nitrospira species (relative abundance <1%), and transcription of nitrite-oxidation genes (undetectable). The addition of sulfide led to simultaneous PN and autotrophic denitrification in the single-stage MABR, resulting in over 60% total inorganic nitrogen removal. Sulfur-based autotrophic denitrification consumed nitrite and inhibited NOB conversion of nitrite to nitrate. The combined strategy has potential to be applied in large-scale sewage treatment and deserves further exploration.


Sujet(s)
Bioréacteurs , Dénitrification , Nitrification , Sulfures , Sulfures/composition chimique , Processus autotrophes , Nitrites/métabolisme , Eaux d'égout , Biofilms , Eaux usées/composition chimique
4.
Anal Chim Acta ; 1311: 342714, 2024 Jul 04.
Article de Anglais | MEDLINE | ID: mdl-38816153

RÉSUMÉ

BACKGROUND: Antibiotics residues can accelerate the growth of drug-resistant bacteria and harm the ecological environment. Under the effect of enrichment and biomagnification, the emergence of drug-resistant pathogenic bacteria may eventually lead to humans being ineffective to drugs in the face of bacterial or fungal disease infections in the future. It is urgent to develop an efficient separation medium and analytical method for simultaneous extraction and determination of antibiotics in the water environment. RESULTS: This work doped 2,6-Di-O-methyl-ß-cyclodextrin, randomly methyl-ß-cyclodextrin, 2-hydroxypropyl-ß-cyclodextrin with thymol:fatty acid respectively to construct non-covalent interaction-dominated pH-responsive ternary supramolecular deep eutectic solvents (SUPRADESs), which can undergo a hydrophilic/hydrophobic transition with aqueous phase to achieve an efficient microextraction. Semi-empirical method illustrated that SUPRADESs have a wide range of hydrogen bond receptor sites. We developed a SUPRADES-based analytical method combined with liquid chromatography-triple quadrupole mass spectrometry for the extraction and determination of trace quinolones and sulfonamides in wastewater. The overall limits of detection of the method were 0.0021-0.0334 ng mL-1 and the limits of quantification were 0.0073-0.1114 ng mL-1. The linearity maintained good in the spiked level of 0.01-100 ng mL-1 (R2 > 0.99). The overall enrichment factors of the method were 157-201 with lower standard deviations (≤8.7). SIGNIFICANCE: The method gave an extraction recovery of 70.1-115.3 % for 28 antibiotics in livestock farming wastewater samples from Zhejiang, China, at trace levels (minimum 0.5 ng mL-1). The results demonstrated that inducing the phase transition between SUPRADES and aqueous phase by adjusting pH for extraction is a novel and efficient pretreatment strategy. To our knowledge, this is the first application of cyclodextrin-based ternary SUPRADESs with pH-responsive reversible hydrophobicity-hydrophilicity transition behavior in wastewater analysis.


Sujet(s)
Cyclodextrines , Solvants eutectiques profonds , Quinolinone , Sulfonamides , Eaux usées , Polluants chimiques de l'eau , Eaux usées/composition chimique , Eaux usées/analyse , Concentration en ions d'hydrogène , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/composition chimique , Polluants chimiques de l'eau/isolement et purification , Sulfonamides/composition chimique , Sulfonamides/analyse , Sulfonamides/isolement et purification , Quinolinone/composition chimique , Quinolinone/isolement et purification , Quinolinone/analyse , Cyclodextrines/composition chimique , Solvants eutectiques profonds/composition chimique
5.
J Med Chem ; 67(8): 6397-6409, 2024 Apr 25.
Article de Anglais | MEDLINE | ID: mdl-38602846

RÉSUMÉ

Aberrantly expressed lysine methyltransferases G9a and GLP, which catalyze mono- and dimethylation of histone H3 lysine 9 (H3K9), have been implicated in numerous cancers. Recent studies have uncovered both catalytic and noncatalytic oncogenic functions of G9a/GLP. As such, G9a/GLP catalytic inhibitors have displayed limited anticancer activity. Here, we report the discovery of the first-in-class G9a/GLP proteolysis targeting chimera (PROTAC) degrader 10 (MS8709), as a potential anticancer therapeutic. 10 induces G9a/GLP degradation in a concentration-, time-, and ubiquitin-proteasome system (UPS)-dependent manner. Futhermore, 10 does not alter the mRNA expression of G9a/GLP and is selective for G9a/GLP over other methyltransferases. Moreover, 10 displays superior cell growth inhibition to the parent G9a/GLP inhibitor UNC0642 in prostate, leukemia, and lung cancer cells and has suitable mouse pharmacokinetic properties for in vivo efficacy studies. Overall, 10 is a valuable chemical biology tool to further investigate the functions of G9a/GLP and a potential therapeutic for treating G9a/GLP-dependent cancers.


Sujet(s)
Antinéoplasiques , Histone-lysine N-methyltransferase , Histone-lysine N-methyltransferase/antagonistes et inhibiteurs , Histone-lysine N-methyltransferase/métabolisme , Humains , Animaux , Antinéoplasiques/pharmacologie , Antinéoplasiques/composition chimique , Antinéoplasiques/synthèse chimique , Souris , Lignée cellulaire tumorale , Protéolyse/effets des médicaments et des substances chimiques , Antigènes d'histocompatibilité/métabolisme , Découverte de médicament , Prolifération cellulaire/effets des médicaments et des substances chimiques , Mâle , Relation structure-activité
6.
bioRxiv ; 2024 Feb 29.
Article de Anglais | MEDLINE | ID: mdl-38464025

RÉSUMÉ

Aberrantly expressed lysine methyltransferases G9a and GLP, which catalyze mono- and di-methylation of histone H3 lysine 9 (H3K9), have been implicated in numerous cancers. Recent studies have uncovered both catalytic and non-catalytic oncogenic functions of G9a/GLP. As such, G9a/GLP catalytic inhibitors have displayed limited anticancer activity. Here, we report the discovery of the first-in-class G9a/GLP proteolysis targeting chimera (PROTAC) degrader, 10 (MS8709), as a potential anticancer therapeutic. 10 induces G9a/GLP degradation in a concentration-, time, and ubiquitin-proteasome system (UPS)-dependent manner, does not alter the mRNA expression of G9a/GLP and is selective for G9a/GLP over other methyltransferases. Moreover, 10 displays superior cell growth inhibition to the parent G9a/GLP inhibitor UNC0642 in prostate, leukemia, and lung cancer cells and has suitable mouse pharmacokinetic properties for in vivo efficacy studies. Overall, 10 is a valuable chemical biology tool to further investigate the functions of G9a/GLP and a potential therapeutic for treating G9a/GLP-dependent cancers.

7.
bioRxiv ; 2024 Jan 13.
Article de Anglais | MEDLINE | ID: mdl-37873443

RÉSUMÉ

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has led to significant global morbidity and mortality. A crucial viral protein, the non-structural protein 14 (nsp14), catalyzes the methylation of viral RNA and plays a critical role in viral genome replication and transcription. Due to the low mutation rate in the nsp region among various SARS-CoV-2 variants, nsp14 has emerged as a promising therapeutic target. However, discovering potential inhibitors remains a challenge. In this work, we introduce a computational pipeline for the rapid and efficient identification of potential nsp14 inhibitors by leveraging virtual screening and the NCI open compound collection, which contains 250,000 freely available molecules for researchers worldwide. The introduced pipeline provides a cost-effective and efficient approach for early-stage drug discovery by allowing researchers to evaluate promising molecules without incurring synthesis expenses. Our pipeline successfully identified seven promising candidates after experimentally validating only 40 compounds. Notably, we discovered NSC620333, a compound that exhibits a strong binding affinity to nsp14 with a dissociation constant of 427 ± 84 nM. In addition, we gained new insights into the structure and function of this protein through molecular dynamics simulations. We identified new conformational states of the protein and determined that residues Phe367, Tyr368, and Gln354 within the binding pocket serve as stabilizing residues for novel ligand interactions. We also found that metal coordination complexes are crucial for the overall function of the binding pocket. Lastly, we present the solved crystal structure of the nsp14-MTase complexed with SS148 (PDB:8BWU), a potent inhibitor of methyltransferase activity at the nanomolar level (IC50 value of 70 ± 6 nM). Our computational pipeline accurately predicted the binding pose of SS148, demonstrating its effectiveness and potential in accelerating drug discovery efforts against SARS-CoV-2 and other emerging viruses.

8.
Environ Sci Technol ; 57(29): 10733-10744, 2023 07 25.
Article de Anglais | MEDLINE | ID: mdl-37429742

RÉSUMÉ

Highly efficient sulfate reduction coupled to autotrophic denitrification plus nitrification is demonstrated by integrating an anaerobic membrane bioreactor (AnMBR) with a membrane aerated biofilm reactor (MABR). Concurrent chemical oxygen demand (COD) removal and sulfate reduction were accomplished in the AnMBR, while simultaneous nitrification and autotrophic denitrification were carried out in the MABR. Separate operation of the MABR achieved >90% total nitrogen (TN) removal when the N/S ratio was controlled at 0.4 gN/gS. The integrated AnMBR-MABR system efficiently resisted influent variability, realizing >95% COD removal in the AnMBR and >75% TN removal in the MABR when the influent COD/N ratio was above 4 gCOD/gN. Membrane fouling did not happen during ∼170 days of operation. Due to sulfide oxidation, a large amount of elemental sulfur (S0) accumulated in the MABR biofilm, where it served as an electron donor for denitrification. Microbial community analysis indicated that Nitrospira and Thiobacillus played key roles in nitrification and sulfide-driven denitrification, respectively, and that they occurred in different layers of the biofilm. This novel process offers advantages of a small land-area footprint, modular operation, and high efficiency electron-donor and oxygen utilizations, particularly for wastewater with a low COD/N ratio.


Sujet(s)
Nitrification , Eaux usées , Dénitrification , Azote , Biofilms , Bioréacteurs , Sulfates
9.
Food Chem ; 411: 135486, 2023 Jun 15.
Article de Anglais | MEDLINE | ID: mdl-36682163

RÉSUMÉ

The existing QuEChERS-combined analytical pretreatment methods are limited by large reagent consumption, high environmental burden, and mediocre effects. To provide an efficient and green pretreatment method, this study developed pH-responsive switchable deep eutectic solvents (SDESs) to extract triazole fungicides (TFs) from fruit peel wastes, which could enhance the preconcentration effect of target compounds in food waste samples with complex matrices. The mechanisms of pH-induced phase transition and hydrophobicity-hydrophilicity conversion of pH-responsive SDESs were investigated by pH phase diagrams and chemical characterization techniques, respectively. We validated the established method by high-performance liquid chromatography-diode array detector (HPLC-DAD), and lower LOD (0.089-0.351 ng mL-1), LOQ (0.297-1.172 ng mL-1), RSD (≤8.8 %) and satisfactory recoveries (90.6 %-110.9 %) and preconcentration factors (389-512) were obtained in rotting grape peel, watermelon peel, and orange peel samples. Our findings highlight the potential of pH-responsive SDESs in the extraction and analysis of various natural food products.


Sujet(s)
Fongicides industriels , Microextraction en phase liquide , Élimination des déchets , Solvants eutectiques profonds , Triazoles , Aliments , Solvants/composition chimique , Concentration en ions d'hydrogène , Microextraction en phase liquide/méthodes
10.
Angew Chem Int Ed Engl ; 61(47): e202211635, 2022 11 21.
Article de Anglais | MEDLINE | ID: mdl-36129393

RÉSUMÉ

Rh-catalyzed dynamic kinetic intramolecular [4+2] cycloaddition reaction of 1,3-disubstituted allene-1,3-dienes afforded cis-fused [4.3.0]bicyclic products with an excellent chemo-, diastereo-, and enantio-selectivity. Many synthetically useful functional groups are tolerated. The synthetic utility has been demonstrated. Based on the careful experimental studies, a mechanism involving the rapid racemization of the allene moiety in the starting materials has been proposed.


Sujet(s)
Rhodium , Réaction de cycloaddition , Stéréoisomérie , Catalyse , Structure moléculaire
11.
Protein Sci ; 31(9): e4395, 2022 09.
Article de Anglais | MEDLINE | ID: mdl-36040262

RÉSUMÉ

SARS-CoV-2 nsp10-nsp16 complex is a 2'-O-methyltransferase (MTase) involved in viral RNA capping, enabling the virus to evade the immune system in humans. It has been considered a valuable target in the discovery of antiviral therapeutics, as the RNA cap formation is crucial for viral propagation. Through cross-screening of the inhibitors that we previously reported for SARS-CoV-2 nsp14 MTase activity against nsp10-nsp16 complex, we identified two compounds (SS148 and WZ16) that also inhibited nsp16 MTase activity. To further enable the chemical optimization of these two compounds towards more potent and selective dual nsp14/nsp16 MTase inhibitors, we determined the crystal structure of nsp10-nsp16 in complex with each of SS148 and WZ16. As expected, the structures revealed the binding of both compounds to S-adenosyl-L-methionine (SAM) binding pocket of nsp16. However, our structural data along with the biochemical mechanism of action determination revealed an RNA-dependent SAM-competitive pattern of inhibition for WZ16, clearly suggesting that binding of the RNA first may help the binding of some SAM competitive inhibitors. Both compounds also showed some degree of selectivity against human protein MTases, an indication of great potential for chemical optimization towards more potent and selective inhibitors of coronavirus MTases.


Sujet(s)
Traitements médicamenteux de la COVID-19 , SARS-CoV-2 , Humains , Methyltransferases/composition chimique , ARN viral/métabolisme , Protéines virales non structurales/composition chimique
12.
Front Plant Sci ; 12: 727966, 2021.
Article de Anglais | MEDLINE | ID: mdl-34759937

RÉSUMÉ

Global warming will have a negative effect on agricultural production as high temperature (HT) stress can seriously threaten plant growth and reproduction. Male sterility caused by HT may be exploited by the creation of a male-sterile line, which has great potential for application in crop heterosis. Therefore, it is important to understand the molecular mechanisms of anther abortion induced by HT in wheat, which remain unclear at present. In this study, we performed phenotype improve language in the abstract and comparative transcriptome analysis of the male sterile anthers induced by HT in wheat. Compared with Normal anthers, the cytological analysis indicated that HT-induced male sterile anthers were smaller and had no starch accumulation in pollen grains, which is consistent with the results observed by scanning electron microscopy (SEM). The 9601 differentially expressed genes (DEGs) identified by transcriptome sequencing compared with the Normal anthers were noticeably involved in the following pathways: starch and sucrose metabolism, phosphatidylinositol (PI) signaling system, peroxidase activity and response to oxidative stress, and heme binding. In addition, TUNEL assays were performed and the results further confirmed the excessive accumulation of reactive oxygen species (ROS) in sterile anthers. Moreover, a total of 38 hub genes were obtained from the protein-protein interaction network analysis of these pathways, including genes, for example, heat shock protein 90 (HSP90), thioredoxin-like protein 1, peroxidase (POD), calreticulin, UDP glucose pyrophosphorylase (UGPase), sucrose synthase, phosphatidylinositol-4-phosphate 5-Kinase (PIP5K), cytochrome c, and Cystathionine beta-synthase X6-like (CBSX6-like). These findings provide insights for predicting the functions of the candidate genes, and the comprehensive analysis of our results is helpful for studying the abortive interaction mechanism induced by HT in wheat.

13.
Genome ; : 1-16, 2021 Oct 14.
Article de Anglais | MEDLINE | ID: mdl-34648728

RÉSUMÉ

Soybean can provide rich protein and fat and has great economic value worldwide. Cadmium (Cd) is a toxic heavy metal to organisms. It can accumulate in plants and be transmitted to the human body via the food chain. Cd is a serious threat to soybean development, particularly root growth. Some soybean cultivars present tolerant symptoms under Cd stress; however, the potential mechanisms are not fully understood. Here, we optimized RNA-seq to identify the differentially expressed genes (DEGs) in Cd-sensitive (KUAI) and Cd-tolerant (KAIYU) soybean roots and compared the DEGs between KAIYU and KUAI. A total of 1506 and 1870 DEGs were identified in the roots of KUAI and KAIYU, respectively. Through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and gene function analyses, we found that genes related to antioxidants and sequestration were responsible for Cd tolerance in KAIYU. In addition, overexpression of Glyma11g02661, which encodes a heavy metal-transporting ATPase, significantly improved Cd tolerance in transgenic hairy roots. These results provide a preliminary understanding of the tolerance mechanisms in response to Cd stress in soybean root development and are of great importance in developing Cd-resistant soybean cultivars by using the identified DEGs through genetic modification.

14.
J Environ Manage ; 255: 109860, 2020 Feb 01.
Article de Anglais | MEDLINE | ID: mdl-31759200

RÉSUMÉ

Papermaking is a capital-intensive industry that requires a high consumption of plant fibers, energy, and water. Previous sustainability assessments of papermaking industry primarily focused on separate evaluations for multiple criteria without the integration for criteria and could not compare the overall priority of the production alternatives. The life cycle sustainability for the most representative boxboard production is analyzed as a case study in this work. Life cycle water consumption, energy consumption, greenhouse gas emissions, and internal costs are selected as the assessment criteria. The two multi-criteria decision-making methods are applied to integrate the above criteria to obtain the sustainability sequence under different production pathways. When the papermaking enterprises are regarded as decision-makers, the alternative using waste paper as raw material to manufacture boxboard is the most sustainable, following by mixed fiber. The sustainability sequence of the alternatives using wood and straw as raw materials is controversial due to the different calculation models. Changing the proportion of raw materials and the criteria weights might adjust sustainability sequence of the alternatives.


Sujet(s)
Consommation de boisson , Gaz à effet de serre , Prise de décision , Effet de serre , Bois
15.
Appl Microbiol Biotechnol ; 103(21-22): 9119-9129, 2019 Nov.
Article de Anglais | MEDLINE | ID: mdl-31501939

RÉSUMÉ

While previous work has demonstrated that antimonate (Sb(V)) can be bio-reduced with methane as the sole electron donor, the microorganisms responsible for Sb(V) reduction remain largely uncharacterized. Inspired by the recently reported Sb(V) reductase belonging to the dimethyl sulfoxide reductase (DMSOR) family, this study was undertaken to use metagenomics and metatranscriptomics to unravel whether any DMSOR family genes in the bioreactor had the potential for Sb(V) reduction. A search through metagenomic-assembled genomes recovered from the microbial community found that some DMSOR family genes, designated sbrA (Sb(V) reductase gene), were highly transcribed in four phylogenetically disparate assemblies. The putative catalytic subunits were found to be representatives of two distinct phylogenetic clades of reductases that were most closely related to periplasmic nitrate reductases and respiratory arsenate reductases, respectively. Putative operons containing sbrA possessed many other components, including genes encoding c-type cytochromes, response regulators, and ferredoxins, which together implement Sb(V) reduction. This predicted ability was confirmed by incubating the enrichment culture with 13C-labeled CH4 and Sb(V) in serum bottles, where Sb(V) was reduced coincident with the production of 13C-labeled CO2. Overall, these results increase our understanding of how Sb(V) can be bio-reduced in environments.


Sujet(s)
Antimoine/métabolisme , Bactéries/enzymologie , Protéines bactériennes/génétique , Oxidoreductases/génétique , Phylogenèse , Bactéries/classification , Bactéries/génétique , Protéines bactériennes/métabolisme , Famille multigénique , Opéron , Oxidoreductases/métabolisme
16.
Chemistry ; 25(40): 9529-9533, 2019 Jul 17.
Article de Anglais | MEDLINE | ID: mdl-31033044

RÉSUMÉ

An efficient chirality transfer in the [RhCl(CO)2 ]2 -catalyzed [2+2+1] cyclization of optically active axially chiral 1,3-disubstituted allenynes with CO to access optically active bicyclopentenone compounds has been developed. The distal C=C bond of allenes reacted with the alknye unit and CO to afford [4.3.0]-bicyclic products with high ee values under mild reaction conditions with an excellent selectivity.

17.
Sci Total Environ ; 655: 1232-1239, 2019 Mar 10.
Article de Anglais | MEDLINE | ID: mdl-30577115

RÉSUMÉ

Formation and recovery of elemental tellurium (Te0) from wastewaters are required by increasing demands and scarce resources. Membrane biofilm reactor (MBfR) using gaseous electron donor has been reported as a low-cost and benign technique to reduce and recover metal (loids). In this study, we demonstrate the feasibility of nanoscale Te0 formation by tellurite (TeO32-) reduction in a CH4-based MBfR. Biogenic Te0 intensively attached on cell surface, within diameters ranging from 10 nm to 30 nm and the hexagonal nanostructure. Along with the Te0 formation, the TeO32- reduction was inhibited. After flushing, biofilm resumed the TeO32- reduction ability, suggesting that the formed nanoscale Te0 might inhibit the reduction by hindering substrate transfer of TeO32- to microbes. The 16S rRNA gene amplicon sequencing revealed that Thermomonas and Hyphomicrobium were possibly responsible for TeO32- reduction since they increased consecutively along with the experiment operation. The PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) analysis showed that the sulfite reductases were positively correlated with the TeO32- flux, indicating they were potential enzymes involved in reduction process. This study confirms the capability of CH4-based MBfR in tellurium reduction and formation, and provides more techniques for resources recovery and recycles.


Sujet(s)
Phénomènes physiologiques bactériens , Biofilms , Nanostructures , Tellure/métabolisme , Élimination des déchets liquides/méthodes , Eaux usées/analyse , Bioréacteurs , Membrane artificielle , Méthane/composition chimique , Phylogenèse , ARN bactérien/analyse , ARN ribosomique 16S/analyse , Élimination des déchets liquides/économie
18.
Environ Sci Pollut Res Int ; 23(18): 17901-9, 2016 Sep.
Article de Anglais | MEDLINE | ID: mdl-27255310

RÉSUMÉ

The effect of citric acid (CA), acetic acid (Ac), and ethylene diamine tetraacetic acid (EDTA) on the photosynthetic and antioxidant properties and the accumulation of some heavy metals (HMs) of Melilotus officinalis seedling growing in Cu mine tailings for 25 days were studied. Results showed that the formation of photosynthesizing cells of M. officinalis was inhibited by EDTA at 2 mmol/kg. Photosynthetic pigment contents under EDTA of 2 mmol/kg were reduced by 26, 40, and 19 %, respectively, compared to the control. The proline contents in aboveground and underground parts increased as the level of EDTA was enhanced. CA and Ac enhanced the activities of superoxide dismutase (SOD) and peroxidase (POD) in the aboveground parts and EDTA inhibited the activity of POD in the underground parts. The addition of CA promoted significantly the growth of M. officinalis, while the biomass decreased significantly under 2 mmol/kg EDTA. Cu contents in the aboveground parts treated with 0.5 and 2.0 mmol/kg EDTA reached 175.50 and 265.17 µg/g dry weight, respectively. Ac and EDTA treatments promoted Cd to translocate from root to aboveground parts. The result indicated that M. officinalis was a tolerant species of Cu tailing and can be used to remediate Cu contaminated environment, and rationally utilization of organic acids, especially EDTA, in the phytoremediation can improve the growth and metals accumulation of M. officinalis.


Sujet(s)
Acide acétique/pharmacologie , Antioxydants/pharmacologie , Acide citrique/pharmacologie , Acide édétique/pharmacologie , Photosynthèse/effets des médicaments et des substances chimiques , Melilotus/effets des médicaments et des substances chimiques , Melilotus/croissance et développement , Myeloperoxidase/métabolisme , Racines de plante/effets des médicaments et des substances chimiques , Racines de plante/métabolisme , Plant/effets des médicaments et des substances chimiques , Superoxide dismutase/métabolisme
19.
Environ Pollut ; 214: 510-516, 2016 Jul.
Article de Anglais | MEDLINE | ID: mdl-27131809

RÉSUMÉ

Pb tolerant mechanisms, plant physiological response and Pb sub-cellular localization in the root cells of Iris halophila were studied in sand culture and the Pb mine tailings. Results showed that the activities of superoxide dismutase (SOD) and peroxidase (POD) in the underground parts and the activity of catalase (CAT) in the aboveground and underground parts increased as Pb level was enhanced. Glutathione (GSH) and ascorbic acid (AsA) contents increased by Pb treatments. Pb deposits were found in the middle cell walls or along the inner side of epibiotic protoplasm of some cells which accumulated a large quantity of Pb and died. The dry weights (DWs) of aboveground parts under all Pb tailings treatments decreased insignificantly, while the DW of the underground parts growing in the pure Pb tailings decreased significantly. Pb, Cu, Cd, and Zn contents increased significantly as the levels of Pb tailings were enhanced and Pb contents in the aboveground and underground parts reached 64.75 and 751.75 µg/g DW, respectively, at pure Pb tailings treatment. The results indicated that I. halophila is a promising plant in the phytoremediation of Pb contaminated environment. Some antioxidant enzymes, antioxidants and compartmentalization of Pb were played major roles in Pb tolerance of I. halophila.


Sujet(s)
Polluants environnementaux/pharmacocinétique , Polluants environnementaux/toxicité , Iris (plante)/effets des médicaments et des substances chimiques , Plomb/pharmacocinétique , Plomb/toxicité , Acide ascorbique/métabolisme , Dépollution biologique de l'environnement , Catalase/métabolisme , Glutathion/métabolisme , Déchets industriels/effets indésirables , Iris (plante)/métabolisme , Mine , Myeloperoxidase/métabolisme , Racines de plante/effets des médicaments et des substances chimiques , Racines de plante/métabolisme , Superoxide dismutase/métabolisme
20.
Chem Commun (Camb) ; 51(32): 6956-9, 2015 Apr 25.
Article de Anglais | MEDLINE | ID: mdl-25797036

RÉSUMÉ

Here, we show a CuBr2-catalyzed approach for a highly enantioselective synthesis (93-99% ee) of allenols from aldehydes and terminal alkynols with the absolute configuration being controlled by applying readily available (R)- or (S)-α,α-diphenylprolinol.


Sujet(s)
Alcènes/composition chimique , Alcynes/composition chimique , Bromures/composition chimique , Cuivre/composition chimique , Phénomènes optiques , Catalyse , Stéréoisomérie
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE