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1.
Environ Res ; 242: 117781, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38036212

RESUMO

In this study, a novel magnetic nanocomposite of Ru@Fe3O4/rGO was successfully synthesized by a simple hydro-thermal method. The Ru@Fe3O4/rGO particles were assembled and immobilized for innovative magnetically assembled electrode (MAE) without any binder, and the electrode was further applied in heterogeneous electro-Fenton (hetero-EF) process for the degradation of diclofenac (DCF). The results showed that rGO could remarkably enhance the conductivity and catalyze the two-electron oxygen reduction, which greatly improved the generation of H2O2. In addition, the mixture valence of Fe and Ru species might provide rich reaction sites and enhance electron transfer by synergy. Thus, the Ru@Fe3O4/rGO MAE exhibited a stable and high electrocatalytic activity in the hetero-EF process for DCF degradation over a wide pH range from 2 to 9 owing to the higher electroactive surface area (EASA) and lower charge/mass-transfer resistance. The DCF degradation efficiency could reach about 100% within 90 min under pH 5 and current 40 mA, and the Ru@Fe3O4/rGO MAE showed high stability and reusability after five cycles. Theoretically, 1O2 and •OH were the main reactive oxygen species (ROS) participating in DCF degradation in the Ru@Fe3O4/rGO MAE hetero-EF process. Furthermore, according to the LC-MS/MS intermediates, the possible DCF degradation pathway was deduced including dechlorination, hydroxylation and ring opening attacked by ROS. Eleven intermediates were detected during DCF degradation in the MAE hetero-EF process, and the ecological risk of DCF degradation in Ru@Fe3O4/rGO MAE hetero-EF process was significantly reduced. This study provides new insights into the magnetically assembled electrode of Ru@Fe3O4/rGO and displays a new practical application prospect of the materials for high-efficient removal and degradation of DCF from wastewater.


Assuntos
Diclofenaco , Poluentes Químicos da Água , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Cromatografia Líquida , Espectrometria de Massas em Tandem , Eletrodos , Oxirredução
2.
Molecules ; 29(17)2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39274968

RESUMO

The increasingly severe antibiotic pollution has become one of the most critical issues. In this study, a zinc peroxide/peroxymonosulfate (ZnO2/PMS) double-oxidation system was developed for tetracycline (TC) degradation. A small amount of ZnO2 (10 mg) and PMS (30 mg) could effectively degrade 82.8% of TC (100 mL, 50 mg/L), and the degradation process could be well described by the pseudo-second-order kinetic model. Meanwhile, the ZnO2/PMS double-oxidation system showed high adaptability in terms of reaction temperature (2-40 °C), initial pH value (4-12), common inorganic anions (Cl-, NO3-, SO42- and HCO3-), natural water source and organic pollutant type. The quenching experiment and electron paramagnetic resonance (EPR) characterization results confirmed that the main reactive oxygen species (ROS) was singlet oxygen (1O2). Moreover, three possible pathways of TC degradation were deduced according to the analyses of intermediates. On the basis of comparative characterization and experiment results, a synergistic activation mechanism was further proposed for the ZnO2/PMS double-oxidation system, accounting for the superior degradation performance. The released OH- and H2O2 from ZnO2 could activate PMS to produce major 1O2 and minor superoxide radicals (•O2-), respectively.


Assuntos
Oxirredução , Peróxidos , Tetraciclina , Peróxidos/química , Tetraciclina/química , Poluentes Químicos da Água/química , Cinética , Zinco/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Espécies Reativas de Oxigênio/metabolismo , Antibacterianos/química , Antibacterianos/farmacologia
3.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32641483

RESUMO

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded open reading frame 50 (ORF50) protein is the key transactivator responsible for the latent-to-lytic switch. Here, we investigated the transcriptional activation of the ORF56 gene (encoding a primase protein) by ORF50 and successfully identified an ORF50-responsive element located in the promoter region between positions -97 and -44 (designated 56p-RE). This 56p-RE element contains a noncanonical RBP-Jκ-binding sequence and a nonconsensus Sp1/Sp3-binding sequence. Electrophoretic mobility shift assays revealed that RBP-Jκ, Sp3, and ORF50 could form stable complexes on the 56p-RE element. Importantly, transient-reporter analysis showed that Sp3, but not RBP-Jκ or Sp1, acts in synergy with ORF50 to activate the 56p-RE-containing reporter construct, and the synergy mainly depends on the Sp1/Sp3-binding region of the 56p-RE element. Sequence similarity searches revealed that the promoters for ORF21 (thymidine kinase), ORF60 (ribonucleotide reductase, small subunit), and cellular interleukin-10 (IL-10) contain a sequence motif similar to the Sp1/Sp3-binding region of the 56p-RE element, and we found that these promoters could also be synergistically activated by ORF50 and Sp3 via the conserved motifs. Noteworthily, the conversion of the Sp1/Sp3-binding sequence of the 56p-RE element into a consensus high-affinity Sp-binding sequence completely lost the synergistic response to ORF50 and Sp3. Moreover, transcriptional synergy could not be detected through other ORF50-responsive elements from the viral PAN, K12, ORF57, and K6 promoters. Collectively, the results of our study demonstrate that ORF50 and Sp3 can act in synergy on the transcription of specific gene promoters, and we find a novel conserved cis-acting motif in these promoters essential for transcriptional synergy.IMPORTANCE Despite the critical role of ORF50 in the KSHV latent-to-lytic switch, the molecular mechanism by which ORF50 activates its downstream target genes, especially those that encode the viral DNA replication enzymes, is not yet fully understood. Here, we find that ORF50 can cooperate with Sp3 to synergistically activate promoters of the viral ORF56 (primase), ORF21 (thymidine kinase), and ORF60 (ribonucleotide reductase) genes via similar Sp1/Sp3-binding motifs. Additionally, the same synergistic effect can be seen on the promoter of the cellular IL-10 gene. Overall, our data reveal an important role for Sp3 in ORF50-mediated transactivation, and we propose a new subclass of ORF50-responsive elements in viral and cellular promoters.


Assuntos
Herpesvirus Humano 8/genética , Proteínas Imediatamente Precoces/genética , Regiões Promotoras Genéticas , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp3/genética , Transativadores/genética , Transcrição Gênica , Animais , Sítios de Ligação , Linhagem Celular , Linhagem Celular Tumoral , Células Clonais , Fibroblastos/virologia , Regulação da Expressão Gênica , Células HEK293 , Herpesvirus Humano 8/metabolismo , Interações Hospedeiro-Patógeno/genética , Humanos , Proteínas Imediatamente Precoces/metabolismo , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/genética , Proteína de Ligação a Sequências Sinal de Recombinação J de Imunoglobina/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Linfócitos/virologia , Camundongos , Ligação Proteica , Elementos de Resposta , Transdução de Sinais , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição Sp3/metabolismo , Transativadores/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo
4.
Molecules ; 23(11)2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30463369

RESUMO

To circumvent the thermodynamic limitation of the synthesis of oxazolidinones starting from 2-aminoethanols and CO2 and realize incorporation CO2 under atmospheric pressure, a protic ionic liquid-facilitated three-component reaction of propargyl alcohols, CO2 and 2-aminoethanols was developed to produce 2-oxazolidinones along with equal amount of α-hydroxyl ketones. The ionic liquid structure, reaction temperature and reaction time were in detail investigated. And 15 mol% 1,5,7-triazabicylo[4.4.0]dec-5-ene ([TBDH][TFE]) trifluoroethanol was found to be able to synergistically activate the substrate and CO2, thus catalyzing this cascade reaction under atmospheric CO2 pressure. By employing this task-specific ionic liquid as sustainable catalyst, 2-aminoethanols with different substituents were successfully transformed to 2-oxazolidinones with moderate to excellent yield after 12 h at 80 °C.


Assuntos
Líquidos Iônicos/química , Oxazolidinonas/síntese química , Alcinos/química , Dióxido de Carbono/química , Etanolaminas/química , Oxazolidinonas/química , Propanóis/química , Temperatura , Termodinâmica
5.
Materials (Basel) ; 17(6)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38541400

RESUMO

The use of electric furnace ferronickel slag (FNS) as a supplementary cementitious material is the current focus of research. This study investigates the effect of mechanical grinding and chemical additives on the activity excition of FNS, as well as the associated synergistic mechanisms. This study shows that the addition of triethanolamine (TEA) increases the fine-grained content in FNS powder, which facilitates the depolymerization of FNS and the early hydration of aluminum tricalcium. Furthermore, the addition of Ca(OH)2 raises the alkalinity of the cementitious system, which promotes the availability of Ca2+ ions and accelerates the hydration process, resulting in the generation of additional hydration products. The enhancement of late hydration of C3S by TEA and its combination with the secondary hydration of Ca2+ at high alkalinity are the pivotal factors to improve the strength of cementitious composite. A mixture of FNS and 0.03% TEA is subjected to grinding for 90 min, using the obtained micropowder which replaces 20% of the cement, and subsequently, after being excited with 3% Ca(OH)2, the FNS micropowder reaches the quality standards of S95 slag powder. It is worth remarking that the micropowder prepared by mixing FNS with 3% Ca(OH)2 and 0.03% TEA and grinding it for 81 min also meets the S95 standard for slag powder. The larger dosage of FNS in cement is supported by the observed synergy between TEA and Ca(OH)2. This research will provide valuable insights for the expanded application of FNS in construction materials.

6.
Methods Mol Biol ; 2743: 43-56, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38147207

RESUMO

Alteration of protein tyrosine phosphatase (PTP) gene expression is a commonly used approach to experimentally analyze their function in the cell physiology of mammalian cells. Here, exemplified for receptor-type PTPRJ (Dep-1, CD148) and PPTRC (CD45), we provide the CRISPR/Cas9-mediated approaches for their inactivation and transcriptional activation using genome editing. These methods are generally applicable to any other protein of interest.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Animais , Sistemas CRISPR-Cas/genética , Ativação Transcricional , Mamíferos
7.
Sci Bull (Beijing) ; 68(1): 65-76, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36581534

RESUMO

As a potential substitute for lithium-ion battery, sodium-ion batteries (SIBs) have attracted a tremendous amount of attention due to their advantages in terms of cost, safety and sustainability. Nevertheless, further improvement of the energy density of cathode materials in SIBs remains challenging and requires the activation of anion redox reaction (ARR) activity to provide additional capacity. Herein, we report a high-performance Mn-based sodium oxide cathode material, Na0.67Mg0.1Zn0.1Mn0.8O2 (NMZMO), with synergistic activation of ARR by cosubstitution. This material can deliver an ultra-high capacity of âˆ¼233 mAh/g at 0.1 C, which is significantly higher than their single-cation-substituted counterparts and among the best in as-reported MgMn or ZnMn-based cathodes. Various spectroscopic techniques were comprehensively employed and it was demonstrated that the higher capacity of NMZMO originated from the enhanced ARR activity. Neutron pair distribution function and resonant inelastic X-ray scattering experiments revealed that out-of-plane migration of Mg/Zn occurred upon charging and oxygen anions in the form of molecular O2 were trapped in vacancy clusters in the fully-charged-state. In NMZMO, Mg and Zn mutually interacted with each other to migrate toward tetrahedral sites, which provided a prerequisite for further ARR activity enhancement to form more trapped molecular O2. These findings provide unique insight into the ARR mechanism and can guide the development of high-performance cathode materials through ARR enhancement strategies.


Assuntos
Fontes de Energia Elétrica , Óxidos , Oxirredução , Íons , Eletrodos , Oxigênio
8.
Chemosphere ; 332: 138860, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37150455

RESUMO

In sulfate radical-based advanced oxidation processes (SR-AOPs), high-efficiency and perdurable materials have drawn considerable interest for use as cathodes, which can effectively degrade refractory organic contaminants through the synergistic electro-activation and transition metal activation of persulfate (PS). Here, the FeCuO@C modified composite cathode (FeCuO@C/AGF) was synthesized via the solvothermal and thermal treatment method based on the CuFe-MOF-74 structure, and the electro-activation PS process (EC/FeCuO@C/AGF/PS) was developed to effectively remove atrazine (ATZ). The surface morphology, electrochemical characteristics, chemical composition, crystal structure, and electrode surface wettability of FeCuO@C/AGF were investigated. It was found that the proposed EC/FeCuO@C/AGF/PS process can successfully remove 100% of ATZ in 20 min at a low current density (2 mA cm-2) and a low PS concentration (0.4 mM), and PS is successfully activated by combining the electrical and transition metal synergistic activation. The FeCuO@C/AGF cathode exhibits outstanding catalytic functionality over a broad pH range (2-9) and remains stable over five successive cycles. Additionally, the active species involved in the reaction as well as the potential ATZ degradation reaction mechanisms and pathways are discussed. Electrochemical oxidation is a process in which both radicals (SO4·-, ·OH, and O2·-) and non-radical (1O2) participate in the degradation of ATZ. The intermediates of the ATZ degradation process were studied upon the toxicity changing, and the toxicity of the intermediates was found to be reduced during degradation. These results present a novel approach toward the establishment of an effective and reliable electrode in SR-AOPs that can efficiently treat pesticide wastewater.


Assuntos
Atrazina , Poluentes Químicos da Água , Atrazina/química , Sulfatos , Águas Residuárias , Oxirredução , Eletrodos , Poluentes Químicos da Água/análise
9.
Microbiol Spectr ; 10(1): e0146421, 2022 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-35019687

RESUMO

The open reading frame 50 (ORF50) protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the master regulator essential for initiating the viral lytic cycle. Previously, we have demonstrated that the ORF50 protein can cooperate with Sp3 to synergistically activate a set of viral and cellular gene promoters through highly conserved ORF50-responsive elements that harbor a Sp3-binding motif. Herein, we show that Sp3 undergoes proteolytic cleavage during the viral lytic cycle, and the cleavage of Sp3 is dependent on caspase activation. Since similar cleavage patterns of Sp3 could be detected in both KSHV-positive and KSHV-negative lymphoma cells undergoing apoptosis, the proteolytic cleavage of Sp3 could be a common event during apoptosis. Mutational analysis identifies 12 caspase cleavage sites in Sp3, which are situated at the aspartate (D) positions D17, D19, D180, D273, D275, D293, D304 (or D307), D326, D344, D530, D543, and D565. Importantly, we noticed that three stable Sp3 C-terminal fragments generated through cleavage at D530, D543, or D565 encompass an intact DNA-binding domain. Like the full-length Sp3, the C-terminal fragments of Sp3 could still retain the ability to cooperate with ORF50 protein to activate specific viral and cellular gene promoters synergistically. Collectively, our findings suggest that despite the proteolytic cleavage of Sp3 under apoptotic conditions, the resultant Sp3 fragments may retain biological activities important for the viral lytic cycle or for cellular apoptosis. IMPORTANCE The ORF50 protein of Kaposi's sarcoma-associated herpesvirus (KSHV) is the key viral protein that controls the switch from latency to lytic reactivation. It is a potent transactivator that can activate target gene promoters via interacting with other cellular DNA-binding transcription factors, such as Sp3. In this report, we show that Sp3 is proteolytically cleaved during the viral lytic cycle, and up to 12 caspase cleavage sites are identified in Sp3. Despite the proteolytic cleavage of Sp3, several resulting C-terminal fragments that have intact zinc-finger DNA-binding domains still retain substantial influence in the synergy with ORF50 to activate specific gene promoters. Overall, our studies elucidate the caspase-mediated cleavage of Sp3 and uncover how ORF50 utilizes the cleavage fragments of Sp3 to transactivate specific viral and cellular gene promoters.


Assuntos
Caspases/metabolismo , Infecções por Herpesviridae/metabolismo , Herpesvirus Humano 8/fisiologia , Fator de Transcrição Sp3/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Apoptose , Caspases/genética , Regulação Viral da Expressão Gênica , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/fisiopatologia , Infecções por Herpesviridae/virologia , Herpesvirus Humano 8/genética , Interações Hospedeiro-Patógeno , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Linfoma/genética , Linfoma/metabolismo , Linfoma/fisiopatologia , Linfoma/virologia , Alinhamento de Sequência , Fator de Transcrição Sp3/química , Fator de Transcrição Sp3/genética , Transativadores/genética , Transativadores/metabolismo , Latência Viral
10.
Chemosphere ; 307(Pt 3): 136074, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35987271

RESUMO

Fe/Mn@carbon cloth (CC) was successfully fabricated through high-temperature shock (HTS) technique and used as cathode modification in heterogeneous electro-Fenton (hetero-EF) process for methylisothiazolinone (MIT) degradation. The nanocrystalline on Fe/Mn@CC electrode is doped with Fe and Mn oxides and coated with carbon layer, which could markedly enhance the electrocatalysis with high electro-chemical active area and low resistance. Fe/Mn@CC modified cathode can efficiently in-situ produce and activate H2O2, showing high electrocatalytic activity to MIT degradation. The 95.2% MIT degradation with in 100 min were achieved under the condition of 30 mA current, 0.75 L min-1 aeration intensity and initial pH = 3. Based on the CV curves and stability test, the high degradation activity revealed the kinetically beneficial regeneration of FeII/MnII in Fe/Mn@CC and activation of H2O2. The electron transfer between FeII/III and MnII/III, together with the direct FeII/MnII regeneration on the cathode, could markedly promote the H2O2 utilization, and eventually lead to MIT degradation.


Assuntos
Peróxido de Hidrogênio , Poluentes Químicos da Água , Carbono , Eletrodos , Compostos Ferrosos , Peróxido de Hidrogênio/química , Oxirredução , Óxidos , Temperatura , Poluentes Químicos da Água/análise
11.
Biotechnol Prog ; 38(3): e3240, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35073456

RESUMO

The dedifferentiation of articular chondrocytes during in vitro expansion deteriorates the hyaline cartilage regeneration. Many approaches have been developed to enhance the redifferentiation of chondrocytes. In this study, a new and effective protocol to improve the redifferentiation of porcine chondrocytes in a pellet form was established. Pellets were initially treated in the modified culture media containing ternary mixtures, binary mixtures, or single reagents of sodium citrate (SCi), sodium chloride (SCh), and ethylenediaminetetraacetic acid (EDTA) at varied concentrations during the first 3 days of culture, followed by a normal culture medium until 21 days. Viability, proliferation, cartilaginous gene expression, extracellular matrix formation, and morphology of treated cell pellets were comparatively examined. Chondrocytes exposed to SCi, SCh, and EDTA individually or in combinations of two or three chemicals were non-cytotoxic when the concentration ranges of the chemicals were 1.83-2.75, 5.00-7.50, and 1.00-1.50 mM, respectively. Cells treated with the modified media containing EDTA alone and EDTA-containing mixtures enhanced glycosaminoglycan production as well as upregulated cartilaginous gene expression, despite their low proliferation rates. Overall, when all three reagents were in use, a pronounced synergistic effect on the activations of glycosaminoglycan accumulation and type II collagen production was explicitly observed at most, particularly when cells were cultured in the medium containing SCi, SCh, and EDTA at concentrations of 2.20, 6.00, and 1.20 mM, respectively. With a use of this protocol, the redifferentiation of articular chondrocytes for regeneration of hyaline cartilage for tissue engineering applications could be readily achieved.


Assuntos
Cartilagem Articular , Condrócitos , Animais , Diferenciação Celular , Células Cultivadas , Condrócitos/metabolismo , Ácido Edético/farmacologia , Glicosaminoglicanos/metabolismo , Glicosaminoglicanos/farmacologia , Suínos , Engenharia Tecidual/métodos
12.
Chemosphere ; 240: 124979, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726597

RESUMO

Activation of peroxymonosulfate (PMS) and persulfate (PS) by Fe2+ is widely used for oxidizing organic pollutants. However, their application is limited by the slow conversion rate of Fe3+ to Fe2+ and the accumulation of Fe3+. Here, we introduce commercial molybdenum disulfide (MoS2) to promote the activation of PMS and PS by Fe2+, and explore the mechanism of this promotion using experimental and theoretical methods. The Fe2+/PMS/MoS2 and Fe2+/PS/MoS2 systems achieved faster rate of PMS and PS conversion and also higher degradation efficiency toward pollutants. About 94.7% and 87.6% of rhodamine B (RhB) could be degraded in Fe2+/PMS/MoS2 (54 µM Fe2+, 1 mM PMS) and Fe2+/PS/MoS2 (54 µM Fe2+, 0.25 mM PS) system, respectively. MoS2 addition simultaneously promoted the Fe3+/Fe2+ cycle, the PMS and PS conversion, and the RhB mineralization. As a co-catalyst, MoS2 exhibited excellent stability for eight successive cycles of use. The predominant oxidant was identified as SO4- in Fe2+/PMS/MoS2 and Fe2+/PS/MoS2 systems. Theoretical calculations and a kinetic model were employed to evaluate the catalytic performance of the systems. These novel findings indicate that the combination of a commercially available MoS2 catalyst with a low dosage of Fe2+ is a promising and effective approach for efficient activation of PMS and PS to produce SO4- and OH.


Assuntos
Dissulfetos/química , Poluentes Ambientais/química , Ferro/química , Molibdênio/química , Peróxidos/química , Sulfatos/química , Catálise , Sinergismo Farmacológico , Cinética , Rodaminas/química
13.
J Colloid Interface Sci ; 557: 207-215, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521970

RESUMO

The development of a suitable catalytic system in the single catalyst has always been the pursuit for synthetic chemists in order to perform the traditional stepwise reactions in one-pot mode. In this work, an ultra-stable bifunctional catalyst of Pd@MIL-101-SO3H was successfully constructed and applied in the one-pot oxidation-acetalization reaction whose products have been widely utilized as fuel additives, perfumes, pharmaceuticals and polymer chemistry. The excellent catalytic performance (>99% yields), on the one hand, can be ascribed to the synergistic effects of Pd NPs with both Lewis and Bronsted acid encapsulated within a sulfonated MIL-101(Cr). On the other hand, the exceptionally high capacity of water adsorption in MIL-101(Cr) could promote the equilibrium movement via interrupting the reversible process. More importantly, Pd@MIL-101-SO3H is recyclable and can be reused for at least 8 times without sacrificing its catalytic activities. As far as we know, this is the first time that a water adsorption enhanced equilibrium movement of reversible reaction by porous catalyst to achieve high yields has been realized in Pd@MIL-101-SO3H, which may provide an absolutely new and efficient strategy especially for designing reaction-oriented catalysts.

14.
J Hazard Mater ; 368: 698-704, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30739022

RESUMO

To activate zero-valent iron (ZVI) for efficient nitrobenzene (NB) reduction, a hybrid Fe0/Fe3O4/FeCl2 microcomposite (hZVIbm) was synthesized via simple ball-milling of the ternary mixture of ZVI, Fe3O4, and FeCl2·4H2O (hZVI). SEM-EDX and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) indicated the hZVIbm microcomposite (10-20 µm) consisted of Fe0 core covered by ∼3.3 µm-thick shell decorated with Fe3O4/FeCl2 fine particles (0.1-2 µm). Efficient removal (>95%) of NB (200 mg/L) was achieved by hZVIbm (2.0 g Fe/L) in 30 min over a wide pH range from 3 to 9. Notably, the NB removal efficiency of hZVIbm was over 30 times higher than the virgin ZVI or over three times higher than hZVI. The enhanced reactivity synergistically resulted from both chemical and physical aspects. Chemically, the Fe3O4/FeCl2-inlaid shell and the Fe(II) components played significant activation roles, as observed from the comparative experiments in their absence via pretreatments of hZVIbm by sonication and rinsing, respectively, with direct evidence of depassivation effect by XRD analysis. Physically, the ball-milling-induced inter-particle compaction effect was considered crucial to facilitate the interfacial mass/electron transfer processes during the reduction. The reduction pathway from NB to aniline via two intermediates was analyzed by liquid chromatography.

15.
Oncol Lett ; 13(4): 2316-2322, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28454397

RESUMO

Sphingosine kinase 1 (Sphk1) is an oncogenic kinase that is responsible for the phosphorylation of sphingosine to sphingosine-1-phosphate (S1P). Mounting evidence suggests that Sphk1 serves a crucial role in the proliferation and development of a variety of human cancer cells. However, the role of Sphk1 in hepatocellular carcinoma (HCC) has not been fully elucidated. Therefore, the expression of Sphk1 was examined in 127 formalin-fixed, paraffin-embedded HCC tissues using immunohistochemistry, and its clinical implications and prognostic significance were analyzed. As a result, the expression of Sphk1 in HCC tissue was revealed to be significantly higher than in normal tissue (P<0.01). In addition, Sphk1 expression was significantly associated with tumor size, tumor stage and histological differentiation (all P<0.05). The patients with low Sphk1 expression had higher overall survival and recurrence-free survival rates compared with patients with high Sphk1 expression. Furthermore, Sphk1-specific shRNA was used to downregulate the expression of Sphk1 in HCC cell lines, including hepatoblastoma G2 and HCC-9724. The CRISPR/Cas9 based transcription activation system was used to upregulate Sphk1 expression in the normal live cell, L02. Cell proliferation, mRNA expression and protein expression were measured using Cell Counting Kit-8, reverse transcription polymerase chain reaction and western blot analysis in the transfected cells. To the best of our knowledge, the present study provides the first evidence that Sphk1 promotes HCC cell proliferation and is involved in tumor progression. Notably, the data presented suggest that Sphk1 may be a potential independent prognosis biomarker for the treatment of HCC.

16.
J Microbiol Biotechnol ; 27(10): 1855-1866, 2017 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-28838224

RESUMO

The synergistic activation mediator (SAM) system can robustly activate endogenous gene expression by a single-guide RNA. This transcriptional modulation has been shown to enhance gene promoter activity and leads to epigenetic changes. Human interferon-γ is a common natural glycoprotein involved in antiviral effects and inhibition of cancer cell growth. Large quantities of high-purity interferon-γ are important for medical research and clinical therapy. To investigate the possibility of employing the SAM system to enhance endogenous human interferon-γ with normal function in innate immunity, we designed 10 single-guide RNAs that target 200 bp upstream of the transcription start sites of the interferon-γ genome, which could significantly activate the interferon-γ promoter reporter. We confirmed that the system can effectively and highly activate interferon-γ expression in several humanized cell lines. Moreover, we found that the interferon-γ induced by the SAM system could inhibit tumorigenesis. Taken together, our results reveal that the SAM system can modulate epigenetic traits of non-immune cells through activating interferon-γ expression and triggering JAK-STAT signaling pathways. Thus, this strategy could offer a novel approach to inhibit tumorigenesis without using exogenous interferon-γ.


Assuntos
Carcinogênese/efeitos dos fármacos , Imunidade Inata , Interferon gama/genética , Interferon gama/metabolismo , Interferon gama/farmacologia , Animais , Apoptose/efeitos dos fármacos , Sistemas CRISPR-Cas , Proliferação de Células/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Fator Regulador 1 de Interferon , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/biossíntese , Fatores de Transcrição/efeitos dos fármacos
17.
Cell Rep ; 21(7): 1727-1736, 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29141208

RESUMO

Mutations in presenilin (PSEN) 1 and 2, which encode components of the γ-secretase (GS) complex, cause familial Alzheimer's disease (FAD). It is hypothesized that altered GS-mediated processing of the amyloid precursor protein (APP) to the Aß42 fragment, which is accumulated in diseased brain, may be pathogenic. Here, we describe an in vitro model system that enables the facile analysis of neuronal disease mechanisms in non-neuronal patient cells using CRISPR gene activation of endogenous disease-relevant genes. In FAD patient-derived fibroblast cultures, CRISPR activation of APP or BACE unmasked an occult processivity defect in downstream GS-mediated carboxypeptidase cleavage of APP, ultimately leading to higher Aß42 levels. These data suggest that, selectively in neurons, relatively high levels of BACE1 activity lead to substrate pressure on FAD-mutant GS complexes, promoting CNS Aß42 accumulation. Our results introduce an additional platform for analysis of neurological disease.


Assuntos
Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Fibroblastos/metabolismo , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/genética , Precursor de Proteína beta-Amiloide/genética , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Sistemas CRISPR-Cas , Células Cultivadas , Fibroblastos/citologia , Humanos , Neurônios/citologia , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , Pele/citologia , Ativação Transcricional
18.
Plant Sci ; 234: 180-93, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25804821

RESUMO

The use of plant biomass as feedstock for biomaterial and biofuel production is relevant in the current bio-based economy scenario of valorizing renewable resources. Fungi, which degrade complex and recalcitrant plant polymers, secrete different enzymes that hydrolyze plant cell wall polysaccharides. The present review discusses the current research trends on fungal, as well as extremophilic cell wall hydrolases that can withstand extreme physico-chemical conditions required in efficient industrial processes. Secretomes of fungi from the phyla Ascomycota, Basidiomycota, Zygomycota and Neocallimastigomycota are presented along with metabolic cues (nutrient sensing, coordination of carbon and nitrogen metabolism) affecting their composition. We conclude the review by suggesting further research avenues focused on the one hand on a comprehensive analysis of the physiology and epigenetics underlying cell wall degrading enzyme production in fungi and on the other hand on the analysis of proteins with unknown function and metagenomics of extremophilic consortia. The current advances in consolidated bioprocessing, altered secretory pathways and creation of designer plants are also examined. Furthermore, recent developments in enhancing the activity, stability and reusability of enzymes based on synergistic, proximity and entropic effects, fusion enzymes, structure-guided recombination between homologous enzymes and magnetic enzymes are considered with a view to improving saccharification.


Assuntos
Parede Celular/metabolismo , Proteínas Fúngicas/metabolismo , Hidrolases/metabolismo , Plantas/microbiologia , Ascomicetos/enzimologia , Ascomicetos/genética , Basidiomycota/enzimologia , Basidiomycota/genética , Biomassa , Proteínas Fúngicas/genética , Fungos/enzimologia , Fungos/genética , Fungos/metabolismo , Hidrolases/genética , Plantas/metabolismo
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