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1.
Artigo em Inglês | MEDLINE | ID: mdl-38813597

RESUMO

Chikungunya virus (CHIKV) is a neglected arthropod-borne and anthropogenic alphavirus. Over the past two decades, the CHIKV distribution has undergone significant changes worldwide, from the original tropics and subtropics regions to temperate regions, which has attracted global attention. However, the interactions between CHIKV and its host remain insufficiently understood, which dampens the need for the development of an anti-CHIKV strategy. In this study, on the basis of the optimal overexpression of non-structural protein 4 (nsP4), we explore host interactions of CHIKV nsP4 using mass spectrometry-based protein-protein interaction approaches. The results reveal that some cellular proteins that interact with nsP4 are enriched in the ubiquitin-proteasome pathway. Specifically, the scaffold protein receptor for activated C kinase 1 (RACK1) is identified as a novel host interactor and regulator of CHIKV nsP4. The inhibition of the interaction between RACK1 and nsP4 by harringtonolide results in the reduction of nsP4, which is caused by the promotion of degradation but not the inhibition of nsP4 translation. Furthermore, the decrease in nsP4 triggered by the RACK1 inhibitor can be reversed by the proteasome inhibitor MG132, suggesting that RACK1 can protect nsP4 from degradation through the ubiquitin-proteasome pathway. This study reveals a novel mechanism by which the host factor RACK1 regulates CHIKV nsP4, which could be a potential target for developing drugs against CHIKV.

2.
Molecules ; 29(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38792123

RESUMO

Despite the rapid progression of organic semiconductors, developing high-air-stability n-type organic semiconductors are still challenging. Herein, novel strong acceptors based on benzothiadiazoloimidazole units are reported. The results reveal that the strong acceptor BTI-NDI-BTI-a has good solubility and high electron affinity (3.94 eV), accompanied by 1D slipped-stacking crystals. Notably, the material presents promising potential for developing into air-stable n-type organic semiconductor materials.

3.
Small ; 19(28): e2207809, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37029458

RESUMO

In situ and micro-scale visualization of electrochemical reactions and multiphase transports on the interface of porous transport electrode (PTE) materials and solid polymer electrolyte (SPE) has been one of the greatest challenges for electrochemical energy conversion devices, such as proton exchange membrane electrolyzer cells (PEMECs), CO2 reduction electrolyzers, PEM fuel cells, etc. Here, an interface-visible characterization cell (IV-CC) is developed to in situ visualize micro-scaled and rapid electrochemical reactions and transports in PTE/SPE interfaces. Taking the PEMEC of a green hydrogen generator as a study case, the unanticipated local gas blockage, micro water droplets, and their evolution processes are successfully visualized on PTE/PEM interfaces in a practical PEMEC device, indicating the existence of unconventional reactant supply pathways in PEMs. Further comprehensive results reveal that PEM water supplies to reaction interfaces are significantly impacted with current densities. These results provide critical insights about the reaction interface optimization and mass transport enhancement in various electrochemical energy conversion devices.

4.
Opt Express ; 31(5): 8797-8804, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36859987

RESUMO

Polarization-sensitive narrowband photodetection at near-infrared (NIR) has attracted significant interest in optical communication, environmental monitoring, and intelligent recognition system. However, the current narrowband spectroscopy heavily relies on the extra filter or bulk spectrometer, which deviates from the miniaturization of on-chip integration. Recently, topological phenomena, such as the optical Tamm state (OTS), provided a new solution for developing functional photodetection, and we experimentally realized the device based on 2D material (graphene) for the first time to the best of our knowledge. Here, we demonstrate polarization-sensitive narrowband infrared photodetection in OTS coupled graphene devices, which are designed with the aid of the finite-difference time-domain (FDTD) method. The devices show narrowband response at NIR wavelengths empowered by the tunable Tamm state. The full width at half maximum (FWHM) of the response peak reaches ∼100 nm, and it can potentially be improved to ultra-narrow of about 10 nm by increasing the periods of dielectric distributed Bragg reflector (DBR). The responsivity and response time of the device reaches 187 mA/W and ∼290 µs at 1550 nm, respectively. Furthermore, the prominent anisotropic features and high dichroic ratios of ∼4.6 at 1300 nm and ∼2.5 at 1500 nm are achieved by integrating gold metasurfaces.

5.
Cell Commun Signal ; 21(1): 336, 2023 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-37996949

RESUMO

BACKGROUND: Foetal renal dysplasia is still the main cause of adult renal disease. Placenta-derived exosomes are an important communication tool, and they may play an important role in placental (both foetal and maternal) function. We hypothesize that in women with preeclampsia, foetal renal dysplasia is impeded by delivering placenta-derived exosomes to glomerular endothelial cells. METHODS: In the present study, we established a PE trophoblast oxidative stress model to isolate exosomes from supernatants by ultracentrifugation (NO-exo and H/R-exo) and collected normal and PE umbilical cord blood plasma to isolate exosomes by ultracentrifugation combined with sucrose density gradient centrifugation (N-exo and PE-exo), then we investigated their effects on foetal kidney development by in vitro, ex vivo and in vivo models. RESULTS: The PE trophoblast oxidative stress model was established successfully. After that, in in vitro studies, we found that H/R-exo and PE-exo could adversely affect glomerular endothelial cell proliferation, tubular formation, migration, and barrier functions. In ex vivo studies, H/R-exo and PE-exo both inhibited the growth and branch formation of kidney explants, along with the decrease of VE-cadherin and Occludin. In in vivo studies, we also found that H/R-exo and PE-exo could result in renal dysplasia, reduced glomerular number, and reduced barrier function in foetal mice. CONCLUSIONS: In conclusion, we demonstrated that PE placenta-derived exosomes could lead to foetal renal dysplasia by delivering placenta-derived exosomes to foetal glomerular endothelial cells, which provides a novel understanding of the pathogenesis of foetal renal dysplasia. Video Abstract.


Assuntos
Exossomos , Pré-Eclâmpsia , Adulto , Humanos , Feminino , Camundongos , Gravidez , Animais , Células Endoteliais , Placenta , Glomérulos Renais
6.
J Environ Manage ; 348: 119049, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37837762

RESUMO

Nitrogen removal is often limited in municipal wastewater treatment due to the lack of sufficient carbon source. Utilizing volatile fatty acids (VFAs) from waste activated sludge (WAS) fermentation broth as a carbon source is an ideal alternative to reduce the cost for wastewater treatment plants (WWTPs) and improve denitrification efficiency simultaneously. In this study, an anaerobic system was applied for simultaneous denitrification and WAS fermentation and the addition of magnetic microparticles (MMP) were confirmed to enhance both denitrification and WAS fermentation. Firstly, the addition of MMP increased the nitrate reduction rate by over 25.36% and improve the production of N2. Additionally, the equivalent chemical oxygen demand (COD) of the detected VFAs increased by 7.06%-14.53%, suggesting that MMP promoted the WAS fermentation. The electron transfer efficiency of denitrifies was accelerated by MMP via electron-transporting system (ETS) activity and cyclic voltammetry (CV) experiments, which might result in the promotional denitrification and WAS fermentation performance. Furthermore, the high-throughput sequencing displayed that, MMP enriched key microbes capable of degrading the complex organics (Chloroflexi, Synergistota and Spirochaetota) as well as the typical denitrifies (Bacteroidetes_vadinHA17 and Denitratisoma). Therefore, this study provides a novel strategy to realize simultaneous WAS utilization and denitrification for WWTPs.


Assuntos
Desnitrificação , Esgotos , Fermentação , Pós , Reatores Biológicos , Carbono , Eliminação de Resíduos Líquidos , Ácidos Graxos Voláteis , Bactérias , Nitrogênio , Fenômenos Magnéticos
7.
Small ; 18(14): e2107745, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35174962

RESUMO

An anode electrode concept of thin catalyst-coated liquid/gas diffusion layers (CCLGDLs), by integrating Ir catalysts with Ti thin tunable LGDLs with facile electroplating in proton exchange membrane electrolyzer cells (PEMECs), is proposed. The CCLGDL design with only 0.08 mgIr cm-2 can achieve comparative cell performances to the conventional commercial electrode design, saving ≈97% Ir catalyst and augmenting a catalyst utilization to ≈24 times. CCLGDLs with regulated patterns enable insight into how pattern morphology impacts reaction kinetics and catalyst utilization in PEMECs. A specially designed two-sided transparent reaction-visible cell assists the in situ visualization of the PEM/electrode reaction interface for the first time. Oxygen gas is observed accumulating at the reaction interface, limiting the active area and increasing the cell impedances. It is demonstrated that mass transport in PEMECs can be modified by tuning CCLGDL patterns, thus improving the catalyst activation and utilization. The CCLGDL concept promises a future electrode design strategy with a simplified fabrication process and enhanced catalyst utilization. Furthermore, the CCLGDL concept also shows great potential in being a powerful tool for in situ reaction interface research in PEMECs and other energy conversion devices with solid polymer electrolytes.

8.
Mol Med ; 27(1): 27, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33794764

RESUMO

BACKGROUND: Growth factors execute essential biological functions and affect various physiological and pathological processes, including peripheral nerve repair and regeneration. Our previous sequencing data showed that the mRNA coding for betacellulin (Btc), an epidermal growth factor protein family member, was up-regulated in rat sciatic nerve segment after nerve injury, implying the potential involvement of Btc during peripheral nerve regeneration. METHODS: Expression of Btc was examined in Schwann cells by immunostaining. The function of Btc in regulating Schwann cells was investigated by transfecting cultured cells with siRNA segment against Btc or treating cells with Btc recombinant protein. The influence of Schwann cell-secreted Btc on neurons was determined using a co-culture assay. The in vivo effects of Btc on Schwann cell migration and axon elongation after rat sciatic nerve injury were further evaluated. RESULTS: Immunostaining images and ELISA outcomes indicated that Btc was present in and secreted by Schwann cells. Transwell migration and wound healing observations showed that transfection with siRNA against Btc impeded Schwann cell migration while application of exogenous Btc advanced Schwann cell migration. Besides the regulating effect on Schwann cell phenotype, Btc secreted by Schwann cells influenced neuron behavior and increased neurite length. In vivo evidence supported the promoting role of Btc in nerve regeneration after both rat sciatic nerve crush injury and transection injury. CONCLUSION: Our findings demonstrate the essential roles of Btc on Schwann cell migration and axon elongation and imply the potential application of Btc as a regenerative strategy for treating peripheral nerve injury.


Assuntos
Betacelulina/uso terapêutico , Regeneração Nervosa/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Células de Schwann/efeitos dos fármacos , Nervo Isquiático/efeitos dos fármacos , Animais , Betacelulina/genética , Betacelulina/metabolismo , Betacelulina/farmacologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Gânglios Espinais/citologia , Masculino , Neurônios/fisiologia , RNA Interferente Pequeno/genética , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Células de Schwann/metabolismo , Células de Schwann/fisiologia , Nervo Isquiático/lesões , Nervo Isquiático/fisiologia
9.
BMC Pregnancy Childbirth ; 21(1): 837, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930169

RESUMO

BACKGROUND: Preeclampsia (PE) is a major cause of maternal and perinatal morbidity and mortality. Studies on the role of microRNAs (miRNAs), in the pathogenesis of PE through their effects on trophoblast function have been reported, but roles for some miRNAs including miR-513c-5p, have not been identified. We aimed to evaluate potential miRNA candidates that regulate the LRP6 mRNAand to elucidate the possible mechanism in PE. Potential miRNAs were selected by bioinformatics analysis, PCR of placenta tissues and dual luciferase reporter assay of HTR-8/SVneo cells. METHODS: A bioinformatics analysis (Gene Expression Omnibus, GEO; miRWalk) was performed to screen the possible miRNAs that participate in the pathology of PE. Placentas from patients with PE and women with a normal pregnancy were collected to detect the expression of predicted miRNAs by RT-qPCR. A dual luciferase reporter assay was used to test the binding of the potential miRNAs to LRP6. The effects of miR-513c-5p on the biological functions of HTR-8/SVneo cells were further evaluated by performing EdU staining, flow cytometry, wound healing assays and Transwell assays. RESULTS: GEO and miRWalk predicted 16 miRNAs that might target LRP6. Hsa-miR-371a-5p, hsa-miR-513c-5p, hsa-miR-126-3p, hsa-miR-145-5p, hsa-miR-193b-5p and hsa-miR-296-5p were 6 miRNAs upregulated in the PE placenta. LRP6 was downregulated in patients with PE compared to normal women. miR-513c-5p mimics inhibited LRP6 expression in HTR-8/SVneo cells, and LRP6 is the target gene of miR-513c-5p. miR-513c-5p mimics also inhibited invasion, migration and proliferation of HTR-8/SVneo cells but promoted their apoptosis. CONCLUSIONS: Our study reveals that overexpression of placenta miR-513c-5p is involved in PE by regulating the biological functions of trophoblasts through the inhibition of LRP6.


Assuntos
Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , MicroRNAs/genética , Pré-Eclâmpsia/genética , Trofoblastos/metabolismo , Adulto , Apoptose , Linhagem Celular , Movimento Celular , Proliferação de Células , Regulação para Baixo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Gravidez , Trofoblastos/citologia
10.
Environ Res ; 191: 110225, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32956653

RESUMO

Modeling and simulations are important methods in environmental research. Currently, massive simulation resources from different domains have been developed to simulate various dynamic phenomena and processes to address different environmental problems. These heterogeneous simulation resources (e.g., models, data, and servers) can be wasted if they are not shared and reused effectively. Recently, experts may exchange resources and conduct simulations in the open web environment via these shared and distributed services. However, some challenges remain, such as the heterogeneity and reusability of simulation resources. The goal of this study was to analyze typical scenarios involved in simulation tasks and design a set of service-oriented interfaces for different simulation resources. These interfaces, including the model description interface, model encapsulation interface, server management interface and sim-task operation interface, can be used to describe, encapsulate, manage and invoke environmental simulation resources, which can further contribute to resource assembly for environmental simulation tasks. This study evaluated the case of PM2.5 concentration distribution simulation by meteorological data, land cover data and a random forest model in 2014. Using the designed interface, this study conducted the simulation and explored the influence of different interpolation methods (inverse distance weighting (IDW) and kriging) for meteorological data in the random forest-based PM2.5 concentration simulation. For this case, the results show that kriging is a more suitable interpolation method than IDW for meteorological data in the simulation, and this interface design can organize simulation resources, configure tasks, and balance task loads in different servers on the open web.


Assuntos
Simulação por Computador , Meio Ambiente , Análise Espacial
12.
Anal Chem ; 90(1): 855-858, 2018 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-29198104

RESUMO

The detection of tyrosinase, a biomarker for melanoma, is of great significance. Herein, a fluorescent tyrosinase probe, with resorufin as the fluorophore and m-tolylboronic acid pinacol ester as the receptor, is proposed. The response relies on the tyrosinase-catalyzed hydroxylation of phenylboronic acid pinacol ester at an adjacent position followed by 1,6-rearrangement elimination to release resorufin. This probe well quantifies tyrosinase in the range from 1 to 100 U mL-1 with a detection limit of 0.5 U mL-1. Importantly, the probe exhibits high selectivity for tyrosinase over other biological substances including reactive oxygen species. In addition, it is successfully applied to the imaging of tyrosinase in cells. This probe provides a novel platform for selective detection of tyrosinase in biosystems.


Assuntos
Ácidos Borônicos/química , Corantes Fluorescentes/química , Monofenol Mono-Oxigenase/análise , Oxazinas/química , Ácidos Borônicos/síntese química , Ácidos Borônicos/toxicidade , Linhagem Celular Tumoral , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Humanos , Hidroxilação , Limite de Detecção , Microscopia de Fluorescência/métodos , Oxazinas/síntese química , Oxazinas/toxicidade
13.
Anal Bioanal Chem ; 410(25): 6507-6516, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30027320

RESUMO

As chloride ions (Cl-) play a vital role in maintaining normal physiological activity, detection of chloride ions is quite urgent. Hence, we developed chloride fluorescence probes to highly selectively and sensitively monitor chloride ions. The probe M2 with single emission has a high fluorescence quantum yield (Φ = 45%), and it is capable of quantitative detection of Cl- under physiological conditions (pH = 7.4) and pH = 5.0 with a linear range of 0.1-4.0 mM; nevertheless, it is of the switch-off type. We further synthesized a ratiometric fluorescent probe MY with M2 as raw material, which featured excellent selectivity and anti-interference, and large two-photon cross section (555 GM). The probe is conveniently used to detect Cl- in water samples and biological samples including human sweat, serum, and urine samples, indicating it holds great promise for chloride detection and biological application. Graphical abstract ᅟ.


Assuntos
Cloretos/análise , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Íons , Estrutura Molecular
14.
Nanotechnology ; 27(1): 015703, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26594911

RESUMO

In this work, self-assembled ferroelectric BiFeO3 (BFO) and Pb(Zr,Ti)O3 (PZT) nanocapacitors were fabricated by a one-step pulsed-laser deposition process. Each individual nanocapacitor consists of a SrRuO3 or LaSrMnO3 bottom electrode layer, an epitaxial ferroelectric middle layer and a self-assembled nanoisland of conductive Bi2O3 or PbO2 as the top nanoelectrode. The nanoelectrodes have a lateral size of 10-100 nm depending on various deposition equivalent thickness. The as-fabricated nanocapacitors exhibit unique so-called anti-domain structures, with opposite polarization orientation to that of the naked ferroelectric films, which can be understood by the different interface built-in-voltages between their neighboring layers. They also show apparent reduced coercive fields and enhanced piezoelectricity compared to the naked films, as revealed by the switching spectroscopy piezoresponse force microscopy (SSPFM) and band-excitation mapping. Besides that, individual addressable polarization writing and erasing properties were also observed in these nanocapacitors and the written domain can maintain stability up to 12 h, which is promising for data storage devices.

15.
Pathog Dis ; 822024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38499444

RESUMO

Candida albicans (C. albicans) is a prevalent opportunistic pathogen that causes mucocutaneous and systemic infections, particularly in immunocompromised individuals. Macrophages play a crucial role in eliminating C. albicans in local and bloodstream contexts, while also regulating antifungal immune responses. However, C. albicans can induce macrophage lysis through pyroptosis, a type of regulated cell death. This process can enable C. albicans to escape from immune cells and trigger the release of IL-1ß and IL-18, which can impact both the host and the pathogen. Nevertheless, the mechanisms by which C. albicans triggers pyroptosis in macrophages and the key factors involved in this process remain unclear. In this review, we will explore various factors that may influence or trigger pyroptosis in macrophages induced by C. albicans, such as hypha, ergosterol, cell wall remodeling, and other virulence factors. We will also examine the possible immune response following macrophage pyroptosis.


Assuntos
Candida albicans , Candidíase , Macrófagos , Piroptose , Candida albicans/imunologia , Candida albicans/patogenicidade , Candida albicans/fisiologia , Humanos , Macrófagos/imunologia , Macrófagos/microbiologia , Candidíase/imunologia , Candidíase/microbiologia , Animais , Interações Hospedeiro-Patógeno/imunologia , Fatores de Virulência/imunologia , Interleucina-1beta/metabolismo , Interleucina-1beta/imunologia
16.
Discov Oncol ; 15(1): 214, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847897

RESUMO

Long noncoding RNAs (lncRNAs), which are more than 200 nucleotides in length and do not encode proteins, play crucial roles in governing gene expression at both the transcriptional and posttranscriptional levels. These molecules demonstrate specific expression patterns in various tissues and developmental stages, suggesting their involvement in numerous developmental processes and diseases, notably cancer. Despite their widespread acknowledgment and the growing enthusiasm surrounding their potential as diagnostic and prognostic biomarkers, the precise mechanisms through which lncRNAs function remain inadequately understood. A few lncRNAs have been studied in depth, providing valuable insights into their biological activities and suggesting emerging functional themes and mechanistic models. However, the extent to which the mammalian genome is transcribed into functional noncoding transcripts is still a matter of debate. This review synthesizes our current understanding of lncRNA biogenesis, their genomic contexts, and their multifaceted roles in tumorigenesis, highlighting their potential in cancer-targeted therapy. By exploring historical perspectives alongside recent breakthroughs, we aim to illuminate the diverse roles of lncRNA and reflect on the broader implications of their study for understanding genome evolution and function, as well as for advancing clinical applications.

17.
Bioresour Technol ; 396: 130430, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38342280

RESUMO

Biocarrier is the key factor for the stable operation of moving bed biofilm reactor (MBBR). To achieve efficient simultaneous nitrification and denitrification (SND), this study provided novel flocking materials as biocarriers. The biofilm formation experiment showed that longer flocking carrier was more conducive to biomass accumulation, resulting in greater oxygen uptake rate. The continuous operation results showed that the total nitrogen removal and SND performance of the MBBR with the addition of 5.0 mm flocking carriers reached 52.0 % and 70.5 %, respectively, which were 29.1 % and 33.3 % greater than those of the control. Compared with those in suspended sludge, the extracellular polymeric substances and protein components in the biocarrier were more abundant. Furthermore, the relative abundance of genera related to denitrification and the nitrogen metabolic sequence improved with the addition of the novel flocking biocarriers. This study demonstrated the effectiveness of novel flocking fillers in improving the performance of MBBR.


Assuntos
Desnitrificação , Nitrificação , Eliminação de Resíduos Líquidos/métodos , Biofilmes , Reatores Biológicos , Esgotos , Nitrogênio/metabolismo
18.
Nanomaterials (Basel) ; 14(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38786794

RESUMO

Noble metal nanomaterials with a localized surface plasmon resonance effect exhibit outstanding advantages in areas such as photothermal therapy and photocatalysis. As a unique plasmonic metal nanostructure, gold nanobipyramids have been attracting much interest due to their strong specific local electric field intensity, large optical cross sections, and high refractive index sensitivity. In this study, we propose a novel three-component hetero-nanostructure composed of rough gold nanobipyramids (R-Au NBPs), Pt, and CdS. Initially, purified gold nanobipyramids are regrown to form R-Au NBPs that have a certain degree of roughness. These R-Au NBP substrates with a rough surface provide more hotspots and strengthen the intensity of localized electric fields. Subsequently, Pt and CdS nanoparticles are selectively deposited onto the surface of R-Au NBPs. Pt nanoparticles can provide more active sites. Each component of this hetero-nanostructure directly contacts others, creating multiple electron transfer channels. This novel design allows for tunable localized plasmon resonance wavelengths ranging from the visible to near-infrared regions. These factors contribute to the final superior photothermal conversion performance of the R-Au/Pt-CdS nanohybrids. Under the irradiation of near-infrared light (1064 nm), the photothermal conversion efficiency of R-Au/Pt-CdS reached 38.88%, which is 4.49, 1.5, and 1.22 times higher than that of Au NBPs, R-Au NBPs, and R-Au NBPs/Pt, respectively.

19.
ACS Omega ; 9(19): 21270-21275, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38764683

RESUMO

Using low viscosity engine oil is one of the most economical and easily achievable ways to improve fuel economy. Base oil is a main component in low viscosity engine oils, and therefore, the separation and identification of its are of great significance for oil product developers to prepare high-performance lubricants. However, the extraction methods reported for base oils mainly adopt membrane dialysis, which not only fails to completely separate the base oil but also wastes a large amount of solvent. The reason for this result is that the concentration of substances inside and outside the membrane cannot always be in an imbalanced state of permeation resulting from manual operation. Additionally, most studies primarily focus on the characterization of base oil components, while there are few reports on grade identification. For the above reasons, an economically effective separation technique of base oil from low viscosity gasoline engine oil SN 0W-16 is successfully established by combining improved Soxhlet extraction and a column chromatography separation method. By applying this method, the yield of extracting base oil generally exceeds 96%, and the solvent can also save more than 3 times. Besides, an exclusion method is built through several simple characterization steps including viscosity index (VI), FT-IR, size-exclusion chromatography (SEC), and hydrocarbon composition, which can quickly identify the American Petroleum Institute (API) grade and brand of the base oils.

20.
Bioresour Technol ; 395: 130360, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38266786

RESUMO

A novel suspended carrier was prepared by sticking activated carbon (AC) and magnetite (Fe3O4) onto polypropylene slices. Although this carrier could not reverse the decreased denitrification capacity trends under anoxic conditions at an influent carbon/nitrogen (C/N) ratio of 2, it enhanced denitrification by stimulating sludge reduction and accelerating electron transfer to certain extent. The carrier stuck by mixed AC/Fe3O4 exhibited better performance in terms of sludge reduction, extracellular polymeric substances (EPS) secretion, and denitrification than that merely stuck by AC and Fe3O4 at an influent C/N ratio of 2. The carrier stuck by mixed AC/Fe3O4 increased the total nitrogen removal efficiency by 24.6 % ± 12.5 % in a 72-h denitrification batch experiment compared to the common polypropylene carrier. Moreover, the carrier improved EPS secretion and nitrogen metabolism and promoted the growth of Trichococcus and some denitrifying genera. This study provides a reference for the treatment of low C/N ratio sewage.


Assuntos
Desnitrificação , Esgotos , Óxido Ferroso-Férrico , Carvão Vegetal , Nitrogênio , Polipropilenos , Reatores Biológicos
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