50 research outputs found

    Taxonomy of the family Arenaviridae and the order Bunyavirales : update 2018

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    In 2018, the family Arenaviridae was expanded by inclusion of 1 new genus and 5 novel species. At the same time, the recently established order Bunyavirales was expanded by 3 species. This article presents the updated taxonomy of the family Arenaviridae and the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.Peer reviewe

    2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

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    Correction to: 2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales. Archives of Virology (2021) 166:3567–3579. https://doi.org/10.1007/s00705-021-05266-wIn March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.This work was supported in part through Laulima Government Solutions, LLC prime contract with the US National Institute of Allergy and Infectious Diseases (NIAID) under Contract No. HHSN272201800013C. J.H.K. performed this work as an employee of Tunnell Government Services (TGS), a subcontractor of Laulima Government Solutions, LLC under Contract No. HHSN272201800013C. This work was also supported in part with federal funds from the National Cancer Institute (NCI), National Institutes of Health (NIH), under Contract No. 75N91019D00024, Task Order No. 75N91019F00130 to I.C., who was supported by the Clinical Monitoring Research Program Directorate, Frederick National Lab for Cancer Research. This work was also funded in part by Contract No. HSHQDC-15-C-00064 awarded by DHS S&T for the management and operation of The National Biodefense Analysis and Countermeasures Center, a federally funded research and development center operated by the Battelle National Biodefense Institute (V.W.); and NIH contract HHSN272201000040I/HHSN27200004/D04 and grant R24AI120942 (N.V., R.B.T.). S.S. acknowledges partial support from the Special Research Initiative of Mississippi Agricultural and Forestry Experiment Station (MAFES), Mississippi State University, and the National Institute of Food and Agriculture, US Department of Agriculture, Hatch Project 1021494. Part of this work was supported by the Francis Crick Institute which receives its core funding from Cancer Research UK (FC001030), the UK Medical Research Council (FC001030), and the Wellcome Trust (FC001030).S

    2021 Taxonomic update of phylum Negarnaviricota (Riboviria: Orthornavirae), including the large orders Bunyavirales and Mononegavirales.

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    In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV

    TRPA1 promotes the maturation of embryonic stem cell-derived cardiomyocytes by regulating mitochondrial biogenesis and dynamics

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    Abstract Background Cardiomyocytes derived from pluripotent stem cells (PSC-CMs) have been widely accepted as a promising cell source for cardiac drug screening and heart regeneration therapies. However, unlike adult cardiomyocytes, the underdeveloped structure, the immature electrophysiological properties and metabolic phenotype of PSC-CMs limit their application. This project aimed to study the role of the transient receptor potential ankyrin 1 (TRPA1) channel in regulating the maturation of embryonic stem cell-derived cardiomyocytes (ESC-CMs). Methods The activity and expression of TRPA1 in ESC-CMs were modulated by pharmacological or molecular approaches. Knockdown or overexpression of genes was done by infection of cells with adenoviral vectors carrying the gene of interest as a gene delivery tool. Immunostaining followed by confocal microscopy was used to reveal cellular structure such as sarcomere. Staining of mitochondria was performed by MitoTracker staining followed by confocal microscopy. Calcium imaging was performed by fluo-4 staining followed by confocal microscopy. Electrophysiological measurement was performed by whole-cell patch clamping. Gene expression was measured at mRNA level by qPCR and at protein level by Western blot. Oxygen consumption rates were measured by a Seahorse Analyzer. Results TRPA1 was found to positively regulate the maturation of CMs. TRPA1 knockdown caused nascent cell structure, impaired Ca2+ handling and electrophysiological properties, and reduced metabolic capacity in ESC-CMs. The immaturity of ESC-CMs induced by TRPA1 knockdown was accompanied by reduced mitochondrial biogenesis and fusion. Mechanistically, we found that peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), the key transcriptional coactivator related to mitochondrial biogenesis and metabolism, was downregulated by TRPA1 knockdown. Interestingly, overexpression of PGC-1α ameliorated the halted maturation induced by TRPA1 knockdown. Notably, phosphorylated p38 MAPK was upregulated, while MAPK phosphatase-1 (MKP-1), a calcium-sensitive MAPK inhibitor, was downregulated in TRPA1 knockdown cells, suggesting that TRPA1 may regulate the maturation of ESC-CMs through MKP-1-p38 MAPK-PGC-1α pathway. Conclusions Taken together, our study reveals the novel function of TRPA1 in promoting the maturation of CMs. As multiple stimuli have been known to activate TRPA1, and TRPA1-specific activators are also available, this study provides a novel and straightforward strategy for improving the maturation of PSC-CMs by activating TRPA1. Since a major limitation for the successful application of PSC-CMs for research and medicine lies in their immature phenotypes, the present study takes a big step closer to the practical use of PSC-CMs. Graphical abstrac

    Simultaneously enhancing the electronic and ionic conductivities of Li2ZnTi3O8 via modification with polyacrylonitrile-derived carbon for high-performance anodes

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    Polyacrylonitrile (PAN) with C≡N bonds can be converted to nitrogen-doped carbon during carbonization, which enhances electronic conductivity by compensating for the deficiency of the Li2ZnTi3O8 (LZTO) anode. In this study, LZTO was modified by carbonizing a homogeneous PAN/LZTO powder mixture at approximately 800 ℃ for 5 h in nitrogen stream to uniformly coat nitrogen-doped carbon around the LZTO particles and to yield nitrogen-doped LZTO. PAN-60 exhibited a capacity retention of 74.8% as the current density increased from 0.1 to 1.6 A g−1, and had charge/discharge capacities of 250.1/250.8 mAh g−1 even after 1100 cycles at 0.5 A g−1. Structural and compositional analysis along with electrochemical tests showed that the uniform nitrogen-doped carbon coating and the nitrogen-doped LZTO favor electron transfer, while the defects induced by nitrogen-doping in LZTO promote Li-ion migration. The enhanced electronic and ionic conductivities are favorable to alleviate the polarization during cycling, and thus are responsible for the optimized performance

    Effects of Phosphate on the Adsorption of Heavy Metal Ions onto TiO2 Nanoparticles in Water and Mechanism Analysis

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    BACKGROUND Nano-titanium dioxide (nTiO2) is widely used to remove heavy metals from water. Phosphate, a common inorganic anion in the aquatic environment, can affect the adsorption characteristics of heavy metal ions on nTiO2. However, the current state of knowledge on the influences of phosphate on the adsorption behaviors of heavy metal ions onto TiO2 nanoparticles (nTiO2) is inadequate. Herein, batch adsorption experiments were conducted to investigate the effects of phosphate on the adsorption of heavy metal ions (i.e., Zn2+ and Cd2+) onto suspended nTiO2. OBJECTIVES To elucidate the primary mechanisms controlling the adsorption behaviors of Zn2+ and Cd2+ on suspended nTiO2 in the presence of phosphate under different solution chemistry conditions. METHODS In order to determine the effects of phosphate on the adsorption of heavy metal ions onto nTiO2, batch experiments were conducted by mixing background electrolyte ions, nTiO2, and phosphate, which contained various concentrations of Zn2+ or Cd2+ in 20mL-amber glass vials at room temperature. The pH of solution was adjusted to target 7.0 using 0.1mol/L HCl or 0.1mol/L NaOH accordingly. Then, the mixtures were rotated end-over-end for 24h. After equilibration, the liquid and solid phases were separated by centrifugation at 15000r/min for 20min, and then the supernatants were filtered through 0.22μm pore-size cellulose ester membrane filter (the loss of metal ions can be neglected). The concentrations of Zn2+ or Cd2+ in the filtrate were measured by an inductively coupled plasma-optical emission spectrometry (ICP-OES). The adsorbed metal ions were then determined by the difference between the initial and final concentrations of metal ions in the aqueous phase. Furthermore, the classic Langmuir and Freundlich sorption models were used to correlate the adsorption isotherms. RESULTS (1) Adsorption isotherms showed that the presence of phosphate could enhance the adsorption of metal ions onto nTiO2, the maximum adsorption capacity of Zn2+ and Cd2+ increased from 121.1mg/g and 84.7mg/g to 588.3mg/g and 434.8mg/g, respectively. We propose that phosphate probably enhance the adsorption of Zn2+ and Cd2+ onto nTiO2 by the following mechanisms. Firstly, the ζ-potential of nTiO2 surface becomes more negative with the increase of phosphate concentration in aqueous phase. Consequently, the electrostatic attraction between negatively charged nanoparticles and positively charged metal ions generally increases with increasing phosphate content. Secondly, the phosphate added into nTiO2 suspension inhibits the aggregation of nanoparticles. In this case, more nTiO2 could sufficiently contact metal ions, thus increasing the adsorption sites. Thirdly, phosphate could form an inner-sphere surface complex on the nTiO2 surface, which can greatly influence the surface chemistry of nTiO2[55-57]. These products could strongly immobilize heavy metal ions[40-41]. These results might account for enhanced Zn2+ and Cd2+ adsorption on nTiO2 by forming metal-phosphate-surface ternary complexes in the presence of phosphate.(2) The adsorption of heavy metals onto nTiO2 decreased when concentration of NaCl increased from 0 to 10 mmol/L. It is likely that ionic strength can affect the attachment of nanoparticles via three major mechanisms. Firstly, the presence of competing cations (Na+) of salt reduces the adsorption of metal ions (i.e., Zn2+ and Cd2+) and this effect may have more significant roles with increasing Na+ concentration. Secondly, this could be related to the fact that an increase in ionic strength interferes with the electrostatic attraction between nTiO2 and metal ions. Thus, adsorption of metal ions is suppressed. Thirdly, increasing ionic strength significantly enhances aggregation of nTiO2, and consequently decreases the active surface sites of nTiO2.(3) The coexistence of competing anions (such as Cl-, NO3- and SO42-) weaken the enhancement effect of phosphate on the adsorption of metal ions onto nTiO2, and the order of inhibition is: SO42- >NO3->Cl-. This may be because anions with higher ionic radii (i.e., SO42-) may occupy more surface reactive sites. On the other hand, the competitive adsorption is related to the valence. It is well known that Cl- and NO3- are more likely to form "outer sphere" complexes with binding surfaces. Meanwhile, the electrostatic adsorption and the ion energy of monovalent anions (e.g., Cl- and NO3-) are weaker than those of divalent anions (e.g., SO42-). For this reason, the competitive influence of Cl- and NO3- during the adsorption of metal ions is negligible. In comparison, the divalent anion has a relatively stronger competitiveness on the adsorption of metal ions. CONCLUSIONS The research results show that phosphate can significantly enhance the removal efficiency of nTiO2 to heavy metal ions, but the removal efficiency will be affected by the water chemical conditions in the background solution. Previous studies show that nTiO2 is promising as an adsorbent for the removal of metal ions from aqueous solution. The present study demonstrates that phosphate plays an important role in adsorption of metal ions (e.g., Zn2+ and Cd2+) onto nTiO2. Phosphate significantly enhances adsorption of Zn2+ and Cd2+ onto nTiO2 by forming metal-phosphate-surface ternary complexes and increasing electrostatic attraction. The increase of ionic strength results in the low adsorption of metal ions in the presence of phosphate, resulting from electronic shielding of the negatively charged sites on the nTiO2 surface and competition between Na+ and heavy metal ions for active surface sites. Moreover, the addition of competitive anions inhibits the adsorption of metal ions in the presence of phosphate following the order of SO42->NO3->Cl-. This phenomenon is mainly ascribed to the decrease of phosphate adsorption because of competition between anions and phosphate for adsorption sites on nTiO2 surface, resulting in decreasing the amount of metal-phosphate-surface ternary complexes. Overall, the results obtained from this study indicate that the adsorption of metal ions onto nTiO2 varies greatly with factors such as phosphate, ionic strength, and competitive anions. Therefore, these factors should be well considered to better understand the fate and toxicity of metal ions in the adsorption process for the treatment of wastewater
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