Heavy-metal pollution poses severe threat to ecological systems and presents a great challenge for global sustainability. Portable point-of-care sensing platform for detection/monitoring of ...heavy-metal pollution in the environment is urgently demanded. Herein, a highly sensitive, robust, and low-cost microfluidic electrochemical carbon-based sensor (μCS) for detection of trace heavy metals is presented. The miniaturized μCS devices are based on a microfluidic paper channel combined with a novel three-dimensional layout with working and counter electrodes facing each other and analyte flowing along the microfluidic channel between these two electrodes. Pristine graphite foil free of any surface modifier is not only used as the electronically conductive pad but also directly employed as the working electrode for fabricating the μCS. The resulting simple and portable device was applied in Cd2+ and Pb2+ detection using square-wave anodic stripping voltammetry. Detection limits down to 1.2 μg/L for Cd2+ and 1.8 μg/L for Pb2+ can be achieved over the μCS. The μCS devices are also found to be highly robust, and 10 repetitive measurements with a single μCS device resulted to be highly reproducible.
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 r
Pf
_IL-17A/F 2 and 3 proteins promoted phagocytosis of PBLs more powerfully than the r
Pf
_IL-17A/F1. Furthermore, the r
Pf
_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.
We show that the electrocatalytic properties of nearly monodispersed Au nanoparticles (NPs) and their derived Pt-on-Au (Pt^Au) nanostructures with similarly dispersed Pt entities are dependent on the ...nature of stabilizers involved in the colloidal syntheses of the Au particles. The effect of stabilizer on the activity for oxygen reduction reaction (ORR) of Au NPs significantly outweighed the Au nano-size effect and thus would raise an alert to those reported size-dependent properties of metal NPs carrying various stabilizers in earlier studies. It is also demonstrated that the stabilizer effect on the property of Au NPs can further induce changes in the catalytic properties of their carried Pt. These findings clearly suggest that a proper screening of the stabilizer in the colloidal synthesis of metal NPs would be important for innovative nanomaterials and catalysts.
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
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.
Driven by the transition to a CO2‐neutral energy economy, research on polymer electrolyte fuel cells gained much interest during the last decade, with researchers trying to overcome the sluggish ...kinetics of the oxygen reduction reaction (ORR) limiting their performance. Modification of existing ORR catalysts with small amounts of ionic liquids (IL) represents an innovative approach to altering the catalytic activity and stability. ILs are supposed to take effect by modifying the local microenvironment at electrochemical interfaces. Nevertheless, a thorough understanding about the local distribution of ILs over solid catalysts is still lacking, hindering the IL modification strategy to be a generic approach to rationally modulating the catalytic performance of a catalyst. In this study we employed STEM‐EDS spectral imaging to locate the IL distribution on the catalyst in presence of NafionTM. To overcome the difficulties associated with low energy STEM‐EDS we setup a sophisticated data processing routine based on machine learning.
A sophisticated data processing routine based on machine learning is presented to overcome the difficulties associated with low energy STEM‐EDS mapping of catalysts. The methodology allows to map the distribution of ionic liquid on PtNiCo on carbon catalyst in presence of Nafion.
Interleukin (IL)-22, as a member of the interleukin (IL)-10 family, is an important mediator between the immune cells and epithelial tissues during infection and inflammation. This study reported the ...characterization and mRNA expression patterns of Pf_IL-22 gene and its cell surface-associated receptors Pf_IL-22RA1 and soluble Pf_IL-22RA2 genes in yellow catfish (Pelteobagrus filvidraco). The open reading frames (ORFs) of the Pf_IL-22, Pf_IL-22RA1 and Pf_IL-22RA2 genes were 546 bp, 1740 bp and 690 bp in length, encoding 181, 579 and 229 amino acids, respectively. Alignments of the deduced amino acid sequences present that the Pf_IL-22 has a conserved IL-10 family signature motif, and the Pf_IL-22RA1 and Pf_IL-22RA2 have two conserved fibronectin type-III domains. Quantitative real-time PCR (qPCR) analyses showed that the Pf_IL-22 and Pf_IL-22RA1 mRNAs were highly expressed in mucosal tissues such as the fin, gill, intestine, skin mucus and stomach, and were weakly expressed in the kidney, liver and head kidney of adult yellow catfish, indicating that the Pf_IL-22 transcripts may be mainly produced by mucosal immune cells/tissues in healthy yellow catfish. The mRNA expression levels of the Pf_IL-22RA2 gene were high in the muscle and liver, and were relatively low in the spleen and kidney. The mRNA expression levels of the Pf_IL-22 and its two receptor genes were significantly up-regulated in both mucosal tissues (gill, hindgut, and skin mucus) and systemic immune tissues (spleen, head kidney and blood) after Edwardsiella ictaluri challenge. These results indicated that the Pf_IL-22 and its two receptors genes might play an important role in the innate immune defense against bacterial invasion.
•IL-22, IL-22RA1 and IL-22RA2 genes were identified in yellow catfish.•Deduced amino acid sequences of three genes were analyzed.•IL-22 and IL-22RA1 genes were highly expressed in mucosal immune-related tissues.•Three genes' expression were up-regulated in six tissues after bacterial challenge.
A protocol to quantify the distribution of surface atoms of concave nanocatalysts according to their coordination number is proposed. The 3D surface of an Au@Pd concave nanocube is reconstructed and ...segmented. The crystallographic coordinates and low‐coordinate surface atom densities of the concave facets are determined. The result shows that 32% of the surface atoms are low‐coordinated, which may contribute to the high activity.
Diabetes induces many complications including reduced fertility and low oocyte quality, but whether it causes increased mtDNA mutations is unknown.
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.
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.
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.
Activity, selectivity and stability of carbon-catalyzed 2e- ORR process can be effectively improved via the electrode–electrolyte interface engineering with ionic liquid and cationic surfactant. ...Specifically, the carbon electrode surface is modified by ionic liquid leading to the enhanced oxygen adsorption. The positively charged cationic surfactants facilitate the desorption of the hydrogen peroxide from carbon surface by coulomb interaction. The synergistic modulation of the electrode–electrolyte interface sheds light on the new strategy for the efficiency improvement of hydrogen peroxide electro-synthesis.
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•Electrode-electrolyte interface engineering strategy for efficient H2O2 electrosynthesis.•99.5 % H2O2 selectivity and over 100 h stability for carbon catalyzed ORR.•Ionic liquid modification facilitating O2 adsorption on hydrophobic carbon surface.•H2O2 selectivity improvement with elongation of the ionic liquid alkyl chains.•Promotion of the H2O2 selectivity via Coulomb attractions from surfactants.
Electrosynthesis of hydrogen peroxide (H2O2) via two-electron oxygen reduction reaction (ORR) represents a green alternative route to the conventional energy-intensive anthraquinone process. Nevertheless, the catalytic efficiency of the state-of-the-art electrocatalysts still has large space to improve. Herein, we demonstrate that the electrocatalytic performance of acetylene black can be tailored by regulating the electrode–electrolyte interfacial structure using ionic liquid (IL) and surfactant. The present research disclosed that the catalytic activity is closely related to alkyl chain length of the IL cation. The presence of the IL can increase the electrocatalytic selectivity of H2O2 from 48 % to 90 %. Moreover, the selectivity of H2O2 can even be further improved up to 99 % by adding cationic surfactant in the electrolyte due to the facilitated desorption of HO2– at the electrode interface, and this high selectivity can be well maintained for 100 h. This work emphasizes the importance of rational design and regulation of the cathode-electrolyte interface for improving the ORR activity, shedding light on the potential practical application of electrosynthesis of hydrogen peroxide.
We proposed a strategy to construct ethane-selective permeation membranes for efficient C2H6/C2H4 separation via functionalizing MOF-808 framework with fluorinated carboxylic acids. The resulting ...MMMs afford a superior C2H6/C2H4 selectivity of 2.3 with C2H6 permeability of 4246 Barrer.
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•An ethane-selective MOF-based mixed matrix membrane was fabricated for the first time.•The unique structure of MOF-808 allows fluorinated functionalization to construct various fluorinated MOFs.•The typical membrane exhibits C2H6/C2H4 selectivity of 2.3 with C2H6 permeability of 4246 Barrer.•The ethane-selective behavior benefits from multiple hydrogen bonds formed between ethane and C-F chains.
Membrane technology based on ethane-selective permeation materials is highly imperative for energy-efficient separating C2H6 and C2H4 mixture. Herein, we rationally constructed a fluorinated metal–organic framework based mixed matrix membrane (MMM), which can selectively permeate ethane from a C2H6/C2H4 mixture. The unique structure of MOF-808 allows functionalization of fluorinated carboxylic acid (FCA) in the MOF framework to construct various fluorinated MOFs via a facile post-synthetic strategy. As a proof of concept, four FCAs with different fluorocarbon chain lengths, including trifluoroacetic acid (TFA), pentafluoropropionic acid (PFPA), heptafluorobutyric acid (HFBA), and perfluorovaleric acid (PFVA), were used to create fluorinated MOFs and corresponding MMMs. The typical HFBA-MOF/PIM-1 hybrid membrane exhibits a high C2H6/C2H4 selectivity of about 2.3 with C2H6 permeability of 4246 Barrer at 253 K and 6 bar. Computational simulations confirm that the reversed permeation behavior is attributed to the strong affinity of C2H6 within the fluorinated pore environment, mediated by multiple hydrogen bonds.
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