Key parameters that influence the specific energy of electrochemical double-layer capacitors (EDLCs) are the double-layer capacitance and the operating potential of the cell. The operating potential of the cell is generally limited by the electrochemical window of the electrolyte solution, that is, the range of applied voltages within which the electrolyte or solvent is not reduced or oxidized. Ionic liquids are of interest as electrolytes for EDLCs because they offer relatively wide potential windows. Here, we provide a systematic study of the influence of the physical properties of ionic liquid electrolytes on the electrochemical stability and electrochemical performance (double-layer capacitance, specific energy) of EDLCs that employ a mesoporous carbon model electrode with uniform, highly interconnected mesopores (3DOm carbon). Several ionic liquids with structurally diverse anions (tetrafluoroborate, trifluoromethanesulfonate, trifluoromethanesulfonimide) and cations (imidazolium, ammonium, pyridinium, piperidinium, and pyrrolidinium) were investigated. We show that the cation size has a significant effect on the electrolyte viscosity and conductivity, as well as the capacitance of EDLCs. Imidazolium- and pyridinium-based ionic liquids provide the highest cell capacitance, and ammonium-based ionic liquids offer potential windows much larger than imidazolium and pyridinium ionic liquids. Increasing the chain length of the alkyl substituents in 1-alkyl-3-methylimidazolium trifluoromethanesulfonimide does not widen the potential window of the ionic liquid. We identified the ionic liquids that maximize the specific energies of EDLCs through the combined effects of their potential windows and the double-layer capacitance. The highest specific energies are obtained with ionic liquid electrolytes that possess moderate electrochemical stability, small ionic volumes, low viscosity, and hence high conductivity, the best performing ionic liquid tested being 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide.
In this paper, we present a novel PCR method, termed SiteFinding-PCR, for gene or chromosome walking. The PCR was primed by a SiteFinder at a low temperature, and then the target molecules were amplified exponentially with gene-specific and SiteFinder primers, and screened out by another gene-specific primer and a vector primer. However, non-target molecules could not be amplified exponentially owing to the suppression effect of stem–loop structure and could not be screened out. This simple method proved to be efficient, reliable, inexpensive and time-saving, and may be suitable for the molecules for which gene-specific primers are available. More importantly, large DNA fragments can be obtained easily using this method. To demonstrate the feasibility and efficiency of SiteFinding-PCR, we employed this method to do chromosome walking and obtained 16 positive results from 17 samples.
SUMMARY
Herpes simplex virus-1 (HSV-1) establishes infections in humans and mice but some non-human primates exhibit resistance via unknown mechanisms. Innate immune recognition pathways are highly conserved but are pivotal in determining susceptibility to DNA virus infections. We report that variation of a single amino acid residue in the innate immune sensor cGAS determines species-specific inactivation by HSV-1. The HSV-1 UL37 tegument protein deamidates human and mouse cGAS. Deamidation impairs the ability of cGAS to catalyze cGAMP synthesis, which activates innate immunity. HSV-1 with deamidase-deficient UL37 promotes robust antiviral responses and is attenuated in mice, in a cGAS- and STING-dependent manner. Mutational analyses identified a single asparagine in human and mouse cGAS that is not conserved in many non-human primates. This residue underpins UL37-mediated cGAS deamidation and species permissiveness of HSV-1. Thus, HSV-1 mediates cGAS deamidation for immune evasion and exploits species sequence variation to disarm host defenses.
Interfacial localization of graphene in cocontinuous polymer blends is shown to be effective in stabilizing the cocontinuous morphology and increasing conductivity with a low electrical percolation threshold. We created polylactic acid (PLA) and polystyrene (PS) cocontinuous blends filled with thermally reduced graphene oxide (r-GO) localized at the interface. The resulting conductive composites show dramatically improved conductivity at low filler loadings and an ultralow percolation threshold of 0.028 vol. %. We systematically studied the changes of conductivity and rheology of the PLA-PS composites during annealing. We found that r-GO transfers from the PLA phase to the interface during melt compounding and annealing and forms a spanning 3D network, which effectively suppresses the coarsening of the cocontinuous structure. Our study demonstrated that the 3D r-GO network significantly increases the conductivity and the storage modulus of the melt blends. Finally, we constructed a simple model, which quantitatively explains the correlations between structural, electrical, and rheological properties of conductive polymer composites.
SUMMARY
RIG-I is a pattern recognition receptor that senses viral RNA and is crucial for host innate immune defense. Here we describe a mechanism of RIG-I activation through amidotransferase-mediated deamidation. We show that viral homologues of phosphoribosylformyglycinamide synthase (PFAS), although lacking intrinsic enzyme activity, recruit cellular PFAS to deamidate and activate RIG-I. Accordingly, depletion and biochemical inhibition of PFAS impair RIG-I deamidation and concomitant activation. Purified PFAS and viral homologue thereof deamidate RIG-I in vitro. Ultimately, herpesvirus hijacks activated RIG-I to avoid antiviral cytokine production; loss of RIG-I or inhibition of RIG-I deamidation results in elevated cytokine production. Together, these findings demonstrate a surprising mechanism of RIG-I activation that is mediated by an enzyme.
NF-κB transcription factors regulate the expression of hundreds of genes primarily involved in immune responses. Signaling events leading to NF-κB activation constitute a major antiviral immune pathway. To replicate and persist within their hosts, viruses have evolved diverse strategies to evade and exploit cellular NF-κB immune signaling cascades for their benefit. We summarize recent studies concerning viral manipulation of the NF-κB signaling pathway downstream of pattern recognition receptors. Signal transduction mediated by pattern recognition receptors is a research frontier for both infectious disease and innate immunology.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.