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1.
Fish Shellfish Immunol ; 150: 109623, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38750705

RESUMO

The interleukin-12 (IL-12) family is a class of heterodimeric cytokines that play crucial roles in pro-inflammatory and pro-stimulatory responses. Although some IL-12 and IL-23 paralogues have been found in fish, their functional activity in fish remains poorly understood. In this study, Pf_IL-12p35a/b, Pf_IL-23p19 and Pf_IL-12p40a/b/c genes were cloned from yellow catfish (Pelteobagrus fulvidraco), four α-helices were found in Pf_IL-12p35a/b and Pf_IL-23p19. The transcripts of these six genes were relatively high in mucus and immune tissues of healthy individuals, and in gill leukocytes. Following Edwardsiella ictaluri infection, Pf_IL-12p35a/b and Pf_IL-23p19 mRNAs were induced in brain and kidney (or head kidney), Pf_IL-12p40a mRNA was induced in gill, and Pf_IL-12p40b/c mRNAs were induced in brain and liver (or skin). The mRNA expression of these genes in PBLs was induced by phytohaemagglutinin (PHA) and polyinosinic-polycytidylic acid (poly I:C), while lipopolysaccharides (LPS) induced the mRNA expression of Pf_IL-12p35a and Pf_IL-12p40b/c in PBLs. After stimulation with recombinant (r) Pf_IL-12 and rPf_IL-23 subunit proteins, either alone or in combination, mRNA expression patterns of genes related to T helper cell development exhibited distinct differences. The results suggest that Pf_IL-12 and Pf_IL-23 subunits may play important roles in regulating immune responses to pathogens and T helper cell development.


Assuntos
Peixes-Gato , Infecções por Enterobacteriaceae , Doenças dos Peixes , Proteínas de Peixes , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Imunidade Inata , Subunidade p40 da Interleucina-12 , Animais , Peixes-Gato/genética , Peixes-Gato/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Proteínas de Peixes/química , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Subunidade p40 da Interleucina-12/genética , Subunidade p40 da Interleucina-12/imunologia , Perfilação da Expressão Gênica/veterinária , Imunidade Inata/genética , Edwardsiella ictaluri/fisiologia , Subunidade p35 da Interleucina-12/genética , Subunidade p35 da Interleucina-12/imunologia , Filogenia , Sequência de Aminoácidos , Alinhamento de Sequência/veterinária , Subunidade p19 da Interleucina-23/genética , Subunidade p19 da Interleucina-23/imunologia , Poli I-C/farmacologia
2.
Int J Mol Sci ; 24(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37176078

RESUMO

The yellow catfish (Pelteobagrus fulvidraco) is an economic fish with a large breeding scale, and diseases have led to huge economic losses. Tumor necrosis factor receptor-associated factors (TRAFs) are a class of intracellular signal transduction proteins that play an important role in innate and adaptive immune responses by mediating NF-κB, JNK and MAPK signaling pathways. However, there are few studies on the TRAF gene family in yellow catfish. In this study, the open reading frame (ORF) sequences of TRAF1, TRAF2a, TRAF2b, TRAF3, TRAF4a, TRAF4b, TRAF5, TRAF6 and TRAF7 genes were cloned and identified in yellow catfish. The ORF sequences of the nine TRAF genes of yellow catfish (Pf_TRAF1-7) were 1413-2025 bp in length and encoded 470-674 amino acids. The predicted protein structures of Pf_TRAFs have typically conserved domains compared to mammals. The phylogenetic relationships showed that TRAF genes are conserved during evolution. Gene structure, motifs and syntenic analyses of TRAF genes showed that the exon-intron structure and conserved motifs of TRAF genes are diverse among seven vertebrate species, and the TRAF gene family is relatively conserved evolutionarily. Among them, TRAF1 is more closely related to TRAF2a and TRAF2b, and they may have evolved from a common ancestor. TRAF7 is quite different and distantly related to other TRAFs. Real-time quantitative PCR (qRT-PCR) results showed that all nine Pf_TRAF genes were constitutively expressed in 12 tissues of healthy yellow catfish, with higher mRNA expression levels in the gonad, spleen, brain and gill. After infection with Edwardsiella ictaluri, the expression levels of nine Pf_TRAF mRNAs were significantly changed in the head kidney, spleen, gill and brain tissues of yellow catfish, of which four genes were down-regulated and one gene was up-regulated in the head kidney; four genes were up-regulated and four genes were down-regulated in the spleen; two genes were down-regulated, one gene was up-regulated, and one gene was up-regulated and then down-regulated in the gill; one gene was up-regulated, one gene was down-regulated, and four genes were down-regulated and then up-regulated in the brain. These results indicate that Pf_TRAF genes might be involved in the immune response against bacterial infection. Subcellular localization results showed that all nine Pf_TRAFs were found localized in the cytoplasm, and Pf_TRAF2a, Pf_TRAF3 and Pf_TRAF4a could also be localized in the nucleus, uncovering that the subcellular localization of TRAF protein may be closely related to its structure and function in cellular mechanism. The results of this study suggest that the Pf_TRAF gene family plays important roles in the immune response against pathogen invasion and will provide basic information to further understand the roles of TRAF gene against bacterial infection in yellow catfish.


Assuntos
Peixes-Gato , Infecções por Enterobacteriaceae , Doenças dos Peixes , Animais , Edwardsiella ictaluri/metabolismo , Infecções por Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/veterinária , Peixes-Gato/genética , Fator 1 Associado a Receptor de TNF/genética , Fator 1 Associado a Receptor de TNF/metabolismo , Filogenia , Fator 3 Associado a Receptor de TNF/genética , Proteínas de Peixes/metabolismo , Mamíferos/metabolismo
3.
ACS Appl Mater Interfaces ; 15(15): 18781-18789, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37024101

RESUMO

Non-precious metal catalysts show great promise to replace the state-of-the-art Pt-based catalysts for catalyzing the oxygen reduction reaction (ORR), while their catalytic activity still needs to be greatly improved before their broad-based application. Here, we report a facile approach to improving the performance of zeolitic imidazolate framework-derived carbon (ZDC) toward the ORR by incorporating a small amount of ionic liquid (IL). The IL would preferentially fill the micropores of ZDC and greatly enhance the utilization of the active sites within the micropores, which are initially not accessible due to insufficient surface wetting. It is also disclosed that the ORR activity in terms of kinetic current at 0.85 V depends on the loading amount of the IL, and the maximum activity is obtained at a mass ratio of IL to ZDC at 1.2. The optimum stems from the counterbalance between the enhanced utilization of the active sites within the micropores and the retarded diffusion of the reactants within the IL phase due to its high viscosity.

4.
Front Cell Dev Biol ; 11: 1327466, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38250324

RESUMO

Blood has an important role in the healthcare system, particularly in blood transfusions and immunotherapy. However, the occurrence of outbreaks of infectious diseases worldwide and seasonal fluctuations, blood shortages are becoming a major challenge. Moreover, the narrow specificity of immune cells hinders the widespread application of immune cell therapy. To address this issue, researchers are actively developing strategies for differentiating induced pluripotent stem cells (iPSCs) into blood cells in vitro. The establishment of iPSCs from terminally differentiated cells such as fibroblasts and blood cells is a straightforward process. However, there is need for further refinement of the protocols for differentiating iPSCs into immune cells and red blood cells to ensure their clinical applicability. This review aims to provide a comprehensive overview of the strategies and challenges facing the generation of iPSC-derived immune cells and red blood cells.

5.
Int J Biol Macromol ; 220: 493-509, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35981681

RESUMO

In mammals, six interleukin-17 (IL-17) genes, as potent pro-inflammatory cytokines, all accelerate the inflammatory responses. In teleosts, seven IL-17 genes have been found in various species, but little is known about the function of teleost-specific IL-17N. In this study, teleost IL-17N and IL-17A/F2 genes all had six conserved cysteine residues forming three intrachain disulfide bridges, the length of three exons of teleost IL-17N gene was similar to that of teleost IL-17A/F2 gene, and the neighbor-joining (NJ) phylogenetic tree showed that teleost IL-17N was clustered with vertebrate IL-17A/F, implying that teleost IL-17N gene may be a paralog of teleost IL-17A/F gene. Pelteobagrus fulvidraco (Pf) IL-17N gene was highly expressed in the blood, brain and kidney of healthy yellow catfish. Pf_IL-17N transcript and protein were notably up-regulated in the spleen, head kidney, gill and kidney detected after Edwardsiella ictaluri infection. Lipopolysaccharides (LPS), polyinosinic-polycytidylic acid (Poly I:C) and peptidoglycan (PGN) also remarkably induced the expression of Pf_IL-17N in the isolated peripheral blood leucocytes (PBLs) of yellow catfish. These results reveal that Pf_IL-17N may play important roles in preventing the invasion of pathogens. Furthermore, the recombinant (r) Pf_IL-17N protein could significantly induce the mRNA expressions of inflammatory cytokines, chemokines and antimicrobial peptide genes in yellow catfish in vivo and in vitro, and it also notably promoted the phagocytosis of myeloid cells in the PBLs and the chemotaxis of the PBLs and gill leucocytes (GLs) in yellow catfish. Besides, though the rPf_IL-17N protein could induce and aggravate inflammation infiltration in the kidney of yellow catfish, it did not effectively and notably increase the survival rate of yellow catfish after E. ictaluri infection. Furthermore, the rPf_IL-17N protein could induce the mRNA expressions of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways related genes, and the inhibitor of NF-κB and MAPK signal pathways could restrain the rPf_IL-17N protein-induced inflammatory response. This study provides crucial evidence that the Pf_IL-17N may mediate inflammatory response to eliminate invasive pathogens.


Assuntos
Peixes-Gato , Infecções por Enterobacteriaceae , Doenças dos Peixes , Animais , Peixes-Gato/metabolismo , Cisteína/genética , Dissulfetos , Infecções por Enterobacteriaceae/genética , Infecções por Enterobacteriaceae/prevenção & controle , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/genética , Doenças dos Peixes/prevenção & controle , Proteínas de Peixes/química , Interleucina-17/genética , Interleucinas/genética , Lipopolissacarídeos/farmacologia , Mamíferos/genética , Proteínas Quinases Ativadas por Mitógeno/genética , NF-kappa B/genética , Peptidoglicano/farmacologia , Filogenia , Poli I-C/farmacologia , RNA Mensageiro/metabolismo
6.
Neuroscience ; 482: 18-29, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34896229

RESUMO

Chronic nonspecific low back pain (cNLBP) is a leading contributor to disease burden worldwide that is difficult to treat due to its nonspecific aetiology and complexity. The amygdala is a complex of structurally and functionally heterogeneous nuclei that serve as a key neural substrate for the interactions between pain and negative affective states. However, whether the functions of amygdalar subcomponents are differentially altered in cNLBP remains unknown. Little attention has focused on effective connectivity of the amygdala with the cortex in cNLBP. In this study, thirty-three patients with cNLBP and 33 healthy controls (HCs) were included. Resting-state functional connectivity (rsFC) and effective connectivity of the amygdala and its subregions were examined. Our results showed that the patient group exhibited significantly greater rsFC between the left amygdala and left dorsal medial prefrontal cortex (mPFC), which was negatively correlated with pain intensity ratings. Subregional analyses suggested a difference located at the superficial nuclei of the amygdala. Dynamic causal modelling revealed significantly lower effective connectivity from the left amygdala to the dorsal mPFC in patients with cNLBP than in HCs. Both groups exhibited stronger effective connectivity from the left amygdala to the right amygdala. In summary, these findings not only suggested altered rsFC of the amygdala-mPFC pathway in cNLBP but also implicated an abnormal direction of information processing between the amygdala and mPFC in these patients. Our results further highlight the involvement of the amygdala in the neuropathology of cNLBP.


Assuntos
Dor Lombar , Imageamento por Ressonância Magnética , Tonsila do Cerebelo/diagnóstico por imagem , Córtex Cerebral , Humanos , Dor Lombar/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem
7.
Front Immunol ; 12: 626895, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34267744

RESUMO

In mammals, Interleukin-17 cytokine family plays critical roles in both acute and chronic inflammatory responses. In fish species, three Interleukin-17A/F (IL-17A/F) genes have been identified to be homologous to mammalian IL-17A and IL-17F, but little is known about their functional activity. In this study, Pf_IL-17A/F1, 2 and 3 genes were cloned from yellow catfish (Pelteobagrus fulvidraco) and they differed in protein structure and exon length, implying that they may have divergent bioactivity. Real-time quantitative PCR analyses revealed that three Pf_IL-17A/F genes were highly expressed in blood and mucosal tissues (skin+mucus and gill) from healthy adult fish. The mRNA expressions of Pf_IL-17A/F1, 2 and 3 genes were significantly up-regulated in the gill, skin+mucus, head kidney and spleen after challenge with Edwardsiella ictaluri and in the isolated peripheral blood leucocytes (PBLs) of yellow catfish after stimulation with phytohaemagglutinin (PHA), lipopolysaccharides (LPS), peptidoglycan (PGN) and polyinosinic-polycytidylic acid (Poly I:C). These results indicate that Pf_IL-17A/F1, 2 and 3 genes may play a vital role in the regulation of immune against pathogens. Additionally, the recombinant (r) Pf_IL-17A/F1, 2 and 3 proteins significantly induced the mRNA expressions of proinflammatory cytokines, chemokines and antibacterial peptides genes, and the rPf_IL-17A/F 2 and 3 proteins promoted phagocytosis of PBLs more powerfully than the rPf_IL-17A/F1. Furthermore, the rPf_IL-17A/F1, 2 and 3 proteins might activate the NF-κB and MAPK signal pathways by IL-17RA, ACT1, TRAF6, TRAF2, TRAF5 and TAK1, indicating that the three Pf_IL-17A/F proteins may play different roles in promoting inflammatory response.


Assuntos
Peixes-Gato/genética , Peixes-Gato/imunologia , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Interleucina-17/genética , Interleucina-17/imunologia , Animais , Rim Cefálico/imunologia , Interleucina-17/química , Interleucina-17/classificação , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Lipopolissacarídeos/farmacologia , Peptidoglicano/farmacologia , Fito-Hemaglutininas/farmacologia , Poli I-C/farmacologia , Baço/imunologia
8.
Int J Biol Macromol ; 185: 176-193, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34144067

RESUMO

Inflammation is a common manifestation of body immunity and mediates a cascade of cytokines. Tumor necrosis factor-α (TNF-α), as a multi-effect cytokine, plays an important role in the inflammatory response by interacting with its receptor (TNFR). In this study, Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 genes were cloned from yellow catfish (Pelteobagrus fulvidraco), and bioinformatics analyses showed that the three genes were conserved and possessed similar sequence characteristics as those of other vertebrates. The qPCR results showed that Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 mRNAs were constitutively expressed in 14 tissues and the lymphocytes of four tissues from healthy adults. The mRNA expression levels of Pf_TNF-α and Pf_TNFR1 genes were significantly up-regulated in the spleen, liver, trunk kidney, head kidney and gill after Edwardsiella ictaluri infection, while the mRNA expression of Pf_TNFR2 was significantly up-regulated in the spleen, and down-regulated in the liver and gill. In the isolated peripheral blood leukocytes (PBLs) of yellow catfish, the expression of Pf_TNF-α mRNA was notably up-regulated and the two Pf_TNFR transcripts were distinctly down-regulated after stimulation with lipopolysaccharides (LPS), peptidoglycan (PGN), polyinosinic-polycytidylic acid (Poly I:C) and phytohaemagglutinin (PHA). After stimulated by recombinant (r) Pf_sTNF protein, the mRNA expressions of various inflammatory factors genes were up-regulated in the PBLs. Meanwhile, rPf_sTNF promoted the phagocytic activity of leukocytes, whereas the activity mediated by rPf_sTNF could be inhibited by rPf_TNFR1CRD2/3 and rPf_TNFR2CRD2/3. The up-regulation of TNF-α and IL-1ß mRNAs expression triggered by rPf_sTNF could be inhibited by MAPK inhibitor (VX-702) and NF-κB inhibitor (PDTC). rPf_sTNF induced the expression of FADD mRNA in PBLs and increased the apoptotic rate of PBLs, and inhibiting the NF-κB and MAPK signal pathways could enhance the apoptosis of PBLs. The results indicate that Pf_TNF-α, Pf_TNFR1 and Pf_TNFR2 play important roles in the immune response of yellow catfish to bacterial invasion.


Assuntos
Peixes-Gato/genética , Clonagem Molecular/efeitos dos fármacos , Receptores do Fator de Necrose Tumoral/genética , Fator de Necrose Tumoral alfa/genética , Animais , Biologia Computacional , Feminino , Proteínas de Peixes/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Masculino , Especificidade de Órgãos , Peptidoglicano/farmacologia , Filogenia , Fito-Hemaglutininas/farmacologia , Poli I-C/farmacologia
9.
ChemistryOpen ; 10(5): 600-606, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34028203

RESUMO

Electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) offers a renewable approach to produce the value-added platform chemical 2,5-furandicarboxylic acid (FDCA). The key for the economic viability of this approach is to develop active and selective electrocatalysts. Nevertheless, a reliable catalyst evaluation protocol is still missing, leading to elusive conclusions on criteria for a high-performing catalyst. Herein, we demonstrate that besides the catalyst identity, secondary parameters such as materials of conductive substrates for the working electrode, concentration of the supporting electrolyte, and electrolyzer configurations have profound impact on the catalyst performance and thus need to be optimized before assessing the true activity of a catalyst. Moreover, we highlight the importance of those secondary parameters in suppressing side reactions, which has long been overlooked. The protocol is validated by evaluating the performance of free-standing Cu-foam, and CuCoO modified with NaPO2 H2 and Ni, which were immobilized on boron-doped diamond (BDD) electrodes. Recommended practices and figure of merits in carefully evaluating the catalyst performance are proposed.

10.
Front Immunol ; 12: 625928, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33732247

RESUMO

Edwardsiella ictaluri is a highly destructive pathogen in cultured yellow catfish, thus it was very necessary to study the immune response of yellow catfish against bacterial infection. In this study, RNA-Seq technology was used to study the immune response in two distinct tissues of yellow catfish at eight different time points (h) after E. ictaluri infection. The number of differentially expressed genes (DEGs) in the spleen and liver was low at 3 h and 6 h post-infection, respectively. Afterwards, the most number of DEGs in the spleen was detected at 72 h, while the number of DEGs in the liver maintained a high level from 24 h to 120 h. The GO and KEGG enrichment analyses of DEGs at different time points uncovered that cytokines were continuously transcribed at 6 h to 120 h; whereas the liver is the main organ that secretes the components of the complement system, and metabolic regulation was activated from 12 h to 120 h. Moreover, an overview of the inflammation response of yellow catfish was exhibited including pattern-recognition receptors, inflammatory cytokines, chemokines, complements, and inflammation-related signal pathways. The similar expression tendency of nine genes by qRT-PCR validated the accuracy of transcriptome analyses. The different transcriptomic profiles obtained from the spleen and liver will help to better understand the dynamic immune response of fish against bacterial infection, and will provide basic information for establishing effective measures to prevent and control diseases in fish.


Assuntos
Peixes-Gato/imunologia , Edwardsiella ictaluri/imunologia , Doenças dos Peixes/imunologia , Inflamação/metabolismo , Animais , Peixes-Gato/microbiologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/imunologia , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Hepatite , Imunidade , Fígado/imunologia , Fígado/metabolismo , Baço/imunologia , Baço/metabolismo , Transcriptoma
11.
Angew Chem Int Ed Engl ; 60(6): 3299-3306, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33151593

RESUMO

The recent mechanistic understanding of active sites, adsorbed intermediate products, and rate-determining steps (RDS) of nitrogen (N)-modified carbon catalysts in electrocatalytic oxygen reduction (ORR) and oxygen evolution reaction (OER) are still rife with controversy because of the inevitable coexistence of diverse N configurations and the technical limitations for the observation of formed intermediates. Herein, seven kinds of aromatic molecules with designated single N species are used as model structures to investigate the explicit role of each common N group in both ORR and OER. Specifically, dynamic evolution of active sites and key adsorbed intermediate products including O2 (ads), superoxide anion O2 - *, and OOH* are monitored with in situ spectroscopy. We propose that the formation of *OOH species from O2 - * (O2 - *+H2 O→OOH*+OH- ) is a possible RDS during the ORR process, whereas the generation of O2 from OOH* species is the most likely RDS during the OER process.

12.
Angew Chem Int Ed Engl ; 59(41): 18095-18102, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32697377

RESUMO

The key to fully leveraging the potential of the electrochemical CO2 reduction reaction (CO2RR) to achieve a sustainable solar-power-based economy is the development of high-performance electrocatalysts. The development process relies heavily on trial and error methods due to poor mechanistic understanding of the reaction. Demonstrated here is that ionic liquids (ILs) can be employed as a chemical trapping agent to probe CO2RR mechanistic pathways. This method is implemented by introducing a small amount of an IL ([BMIm][NTf2 ]) to a copper foam catalyst, on which a wide range of CO2RR products, including formate, CO, alcohols, and hydrocarbons, can be produced. The IL can selectively suppress the formation of ethylene, ethanol and n-propanol while having little impact on others. Thus, reaction networks leading to various products can be disentangled. The results shed new light on the mechanistic understanding of the CO2RR, and provide guidelines for modulating the CO2RR properties. Chemical trapping using an IL adds to the toolbox to deduce the mechanistic understanding of electrocatalysis and could be applied to other reactions as well.

13.
ChemElectroChem ; 7(1): 10-30, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-32025468

RESUMO

Paper-based microfluidics is characteristic of fluid transportation through spontaneous capillary action of paper and has exhibited great promise for a variety of applications especially for sensing. Furthermore, paper-based microfluidics enables the design of miniaturized electrochemical devices to be applied in the energy sector, which is especially attractive for the rapid growing market of small size disposable electronics. This review gives a brief summary on the basics of paper chemistry and capillary-driven microfluidic behavior, and highlights recent advances of paper-based microfluidics in developing electrochemical sensing devices and miniaturized energy storage/conversion devices. Their structural features, working principles and exemplary applications are comprehensively elaborated and discussed. Additionally, this review also points out the existing challenges and future opportunities of paper-based microfluidic electronics.

14.
ACS Catal ; 9(9): 8682-8692, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31534827

RESUMO

Ionic liquids (ILs) modification, following the concept of "solid catalyst with ionic liquid layer (SCILL)", has been demonstrated to be an effective approach to improving both activity and stability of Pt-based catalysts for the oxygen reduction reaction. In this work, the SCILL concept has been applied to a trimetallic PtNiMo/C system, which has been documented recently to be significantly advantageous over the benchmark PtNi-based catalysts for oxygen reduction. To achieve this, two hydrophobic ILs ([BMIM][NTF2] and [MTBD][BETI]) were used to modify PtNiMo/C with four IL-loading amounts between 7 and 38 wt %. We found that the Pt mass activity (@0.9 V) could be improved by up to 50% with [BMIM][NTF2] and even 70% when [MTBD][BETI] is used. Exceeding a specific IL loading amount, however, leads to a mass transport related activity drop. Moreover, it is also disclosed that both ILs can effectively suppress the formation of nonreactive oxygenated species, while at the same time imposing little effect on the electrochemical active surface area. For a deeper understanding of the degradation mechanism of pristine and IL modified PtNiMo/C, we applied identical location transmission electron microscopy and in situ scanning flow cell coupled to inductively coupled plasma mass spectrometry techniques. It is disclosed that the presence of ILs has selectively accelerated the dissolution of Mo and eventually results in a more severe degradation of PtNiMo/C. This shows that future research needs to identify ILs that prevent the Mo dissolution to leverage the potential of the IL modification of PtNiMo catalysts.

15.
Lab Chip ; 19(20): 3438-3447, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31556903

RESUMO

Paper-based microfluidics (lab on paper) emerges as an innovative platform for building small-scale devices for sensing, diagnosis, and energy storage/conversions due to the power-free fluidic transport capability of paper via capillary action. Herein, we report for the first time that paper-based microfluidic concept can be employed to fabricate high-performing aluminum-air batteries, which entails the use of a thin sheet of fibrous capillary paper sandwiched between an aluminum foil anode and a catalyst coated graphite foil cathode without using any costly air electrode or external pump device for fluid transport. The unique microfluidic configuration can help overcome the major drawbacks of conventional aluminum-air batteries including battery self-discharge, product-induced electrode passivation, and expensive and complex air electrodes which have long been considered as grand obstacles to aluminum-air batteries penetrating the market. The paper-based microfluidic aluminum-air batteries are not only miniaturized in size, easy to fabricate and cost-effective, but they are also capable of high electrochemical performance. With a specific capacity of 2750 A h kg-1 (@20 mA cm-2) and an energy density of 2900 W h kg-1, they are 8.3 and 12.6 times higher than those of the non-fluidic counterpart and significantly outperform many other miniaturized energy sources, respectively. The superior performance of microfluidic aluminum-air batteries originates from the remarkable efficiency of paper capillarity in transporting electrolyte along with O2 to electrodes.

16.
Beilstein J Nanotechnol ; 10: 419-427, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873312

RESUMO

Carbon materials for electrical energy devices, such as battery electrodes or fuel-cell catalysts, require the combination of the contradicting properties of graphitic microstructure and porosity. The usage of graphitization catalysts during the synthesis of carbide-derived carbon materials results in materials that combine the required properties, but controlling the microstructure during synthesis remains a challenge. In this work, the controllability of the synthesis route is enhanced by immobilizing the transition-metal graphitization catalyst on a porous carbon shell covering the carbide precursor prior to conversion of the carbide core to carbon. The catalyst loading was varied and the influence on the final material properties was characterized by using physisorption analysis with nitrogen as well as carbon dioxide, X-ray diffraction, temperature-programmed oxidation (TPO), Raman spectroscopy, SEM and TEM. The results showed that this improved route allows one to greatly vary the crystallinity and pore structure of the resulting carbide-derived carbon materials. In this sense, the content of graphitic carbon could be varied from 10-90 wt % as estimated from TPO measurements and resulting in a specific surface area ranging from 1500 to 300 m2·g-1.

17.
Sci Rep ; 9(1): 2704, 2019 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-30804376

RESUMO

The phylogeography of Schizothorax waltoni, an endemic and endangered tetraploid schizothoracine fish in the Yarlung Tsangpo River (YLTR) on southern margin of Qinghai-Tibet Plateau (QTP), was investigated using two mitochondrial DNA regions and eleven microsatellite loci. Analyses of concatenated sequences of cytochrome b (1141 bp) and the control region (712 bp) revealed high haplotype diversity and moderate nucleotide diversity. High genetic diversity was observed based on microsatellite variation. Both mtDNA and microsatellite analyses revealed significant genetic differentiation between the eastern population (Mainling) and the other four populations to the west, and non-significant genetic differentiation amongst the three central populations in the west. Significant genetic differentiation was observed between the western population (Shigatse) and the three central populations based on microsatellite analyses alone. Bayesian skyline plot analyses showed that S. waltoni experienced a pronounced population expansion 0.05 to 0.10 Ma. Hierarchical structure analyses of microsatellite data indicated that S. waltoni could be split into three groups (western, central and eastern YLTR). The results indicate that three management units should be considered for S. waltoni. Our findings highlight the need for the conservation and effective management of S. waltoni, which is a key member of the endemic and highly threatened fishes of the QTP.


Assuntos
Cyprinidae/genética , Animais , Teorema de Bayes , Cyprinidae/classificação , DNA Mitocondrial/genética , Repetições de Microssatélites/genética , Filogeografia , Rios
18.
J Virol Methods ; 265: 35-41, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30562608

RESUMO

Dengue fever is a mosquito-borne viral disease with dramatically increasing morbidity rate worldwide in decades. Since there is no specific treatment to date, early diagnosis is important for providing proper timely medical care to minimize mortality, and for the prompt initiation of public health control measures. NS5 is a potential biomarker for dengue virus infection due to its highly conserved and immunogenic properties. In this study, the DENV 2 NS5 full-length and the DENV 2 NS5 C-terminus RNA-dependent RNA polymerase domain fragment (NS5-C70) expression plasmids were constructed, and the 104 kDa full-length NS5 and the 70 kDa NS5-C70 were respectively expressed in Escherichia coli. These two purified recombinant products were found to react with the sera of patients infected with dengue virus when analyzed by an enzyme-linked immunosorbent assay (ELISA), which resulted in significantly higher absorption values than those of control sera. The recombinant DENV 2 NS5 exhibited strong reactivity to each of the four types of sera, whereas the NS5-C70 showed strong reactivity only to DENV 2 and 4. In comparison, the positive agreement value of recombinant NS5-based assay with either MyBioSource or Panbio assay was higher than that of the two commercially available IgG indirect ELISA kits. These results suggest that the recombinant DENV 2 NS5 be an effective antigen for detection of dengue virus infection. The recombinant NS5-C70 may also be used as an auxiliary antigen for diagnostic purposes.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Dengue/diagnóstico , Proteínas Recombinantes/imunologia , Testes Sorológicos/métodos , Proteínas não Estruturais Virais/imunologia , Antígenos Virais/genética , Clonagem Molecular , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Proteínas Recombinantes/genética , Sensibilidade e Especificidade , Proteínas não Estruturais Virais/genética
19.
Reprod Biol Endocrinol ; 16(1): 110, 2018 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-30390692

RESUMO

BACKGROUND: Diabetes induces many complications including reduced fertility and low oocyte quality, but whether it causes increased mtDNA mutations is unknown. METHODS: We generated a T2D mouse model by using high-fat-diet (HFD) and Streptozotocin (STZ) injection. We examined mtDNA mutations in oocytes of diabetic mice by high-throughput sequencing techniques. RESULTS: T2D mice showed glucose intolerance, insulin resistance, low fecundity compared to the control group. T2D oocytes showed increased mtDNA mutation sites and mutation numbers compared to the control counterparts. mtDNA mutation examination in F1 mice showed that the mitochondrial bottleneck could eliminate mtDNA mutations. CONCLUSIONS: T2D mice have increased mtDNA mutation sites and mtDNA mutation numbers in oocytes compared to the counterparts, while these adverse effects can be eliminated by the bottleneck effect in their offspring. This is the first study using a small number of oocytes to examine mtDNA mutations in diabetic mothers and offspring.


Assuntos
DNA Mitocondrial/genética , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Mutação , Oócitos/metabolismo , Animais , DNA Mitocondrial/química , Diabetes Mellitus Experimental/etiologia , Dieta Hiperlipídica/efeitos adversos , Feminino , Fertilidade/genética , Sequenciamento de Nucleotídeos em Larga Escala , Padrões de Herança/genética , Masculino , Camundongos Endogâmicos C57BL , Gravidez , Taxa de Gravidez
20.
ACS Catal ; 8(9): 8244-8254, 2018 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-30221028

RESUMO

Modifying Pt catalysts using hydrophobic ionic liquids (ILs) has been demonstrated to be a facile approach for boosting the performance of Pt catalysts for the oxygen reduction reaction (ORR). This work aims to deepen the understanding and initiate a rational molecular tuning of ILs for improved activity and stability. To this end, Pt/C catalysts were modified using a variety of 1-methyl-3-alkylimidazolium bis(trifluoromethanesulfonyl)imide ([C n C1im][NTf2], n = 2-10) ILs with varying alkyl chain lengths in imidazolium cations, and the electrocatalytic properties (e.g., electrochemically active surface area, catalytic activity, and stability) of the resultant catalysts were systematically investigated. We found that ILs with long cationic chains (C6, C10) efficiently suppressed the formation of nonreactive oxygenated species on Pt; however, at the same time they blocked active Pt sites and led to a lower electrochemically active surface area. It is also disclosed that the catalytic activity strongly correlates with the alkyl chain length of cations, and a distinct dependence of intrinsic activity on the alkyl chain length was identified, with the maximum activity obtained on Pt/C-[C4C1im][NTf2]. The optimum arises from the counterbalance between more efficient suppression of oxygenated species formation on Pt surfaces and more severe passivation of Pt surfaces with elongation of the alkyl chain length in imidazolium cations. Moreover, the presence of an IL can also improve the electrochemical stability of Pt catalysts by suppressing the Pt dissolution, as revealed by combined identical-location transmission electron microscopy (TEM) and in situ inductively coupled plasma mass spectrometry (ICP-MS) analyses.

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