The advent of solid‐state polymer electrolytes for application in lithium batteries took place more than four decades ago when the ability of polyethylene oxide (PEO) to dissolve suitable lithium ...salts was demonstrated. Since then, many modifications of this basic system have been proposed and tested, involving the addition of conventional, carbonate‐based electrolytes, low molecular weight polymers, ceramic fillers, and others. This Review focuses on ternary polymer electrolytes, that is, ion‐conducting systems consisting of a polymer incorporating two salts, one bearing the lithium cation and the other introducing additional anions capable of plasticizing the polymer chains. Assessing the state of the research field of solid‐state, ternary polymer electrolytes, while giving background on the whole field of polymer electrolytes, this Review is expected to stimulate new thoughts and ideas on the challenges and opportunities of lithium‐metal batteries.
Safety net: Polymer electrolytes are a safe alternative to conventional liquid electrolytes in lithium batteries. Their main drawback is low ionic conductivity at room temperature. The most promising solution for this issue is incorporation of ionic liquids, which enhance the performance without decline in safety. This Review elucidates the interactions in these ternary polymer electrolytes and their performance in lithium‐metal polymer batteries.
Herein is reported the performance of ternary polymer electrolytes incorporating ionic liquids, showing higher ionic conductivity over a wide temperature range than binary polymer-salt systems, while ...guaranteeing higher safety compared to liquid, organic electrolytes or gel electrolytes. In particular, the electrochemical performance and the interactions between poly(ethylene oxide) (PEO), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and several pyrrolidinium-based ionic liquids is comparatively investigated. Eight different polymer electrolytes were produced to test the ionic conductivity and long-time (more than 1400 hours) cycling stability in symmetrical lithium cells. Thermal analysis was used to investigate the thermal stability and degree of crystallinity. Six of the eight investigated samples are found fully amorphous at room temperature. In general, the properties of the polymer electrolytes are influenced by both Ionic liquid ions. The ether function in the side chain of the pyrrolidinium increases the ionic conductivity but, in some cases, lowers the thermal and electrochemical stability.
Amorphous PEO-ionic liquid-LiX polymer electrolytes containing mixed imide anions exhibit high ionic conductivity and lithium plating-stripping capability at moderate temperatures.
Die Einführung von Festkörper‐Polymerelektrolyten in Lithiumbatterien vor über vierzig Jahren basierte auf der Fähigkeit von Polyethylenoxid (PEO), bestimmte Lithiumsalze zu lösen. Seitdem wurden ...viele Varianten dieses Systems vorgeschlagen und getestet, unter anderem die Zugabe von herkömmlichen carbonatbasierten Elektrolyten, niedermolekularen Polymeren sowie keramischen Füllstoffen. Dieser Aufsatz gibt einen Überblick über den aktuellen Stand der Forschung zu ternären Polymerelektrolyten, also ionenleitenden Systemen aus einem Polymer und zwei Salzen, eines mit Lithiumkation, das andere mit zusätzlichen Anionen, die das Polymer plastifizieren. Weiterhin werden Grundlagen zu den Wechselwirkungen in Polymerelektrolyten diskutiert, um Überlegungen zu den Herausforderungen und Möglichkeiten von Lithiummetallbatterien anzuregen.
Eine sichere Alternative zu herkömmlichen flüssigen Elektrolyten in Lithiumbatterien bieten Polymerelektrolyte. Ihr größter Nachteil ist die niedrige Ionenleitfähigkeit bei Raumtemperatur. Eine vielversprechende Lösung ist die Beimischung von ionischen Flüssigkeiten, um Leistung und Sicherheit zu erhöhen. Dieser Aufsatz erläutert die Wechselwirkungen in solchen ternären Polymerelektrolyten und ihre Anwendung in Lithiummetallpolymerbatterien.
Die Einfuhrung von Festkörper-Polymerelektrolyten in Lithiumbatterien vor uber vierzig Jahren basierte auf der Fähigkeit von Polyethylenoxid (PEO), bestimmte Lithiumsalze zu lösen. Seitdem wurden ...viele Varianten dieses Systems vorgeschlagen und getestet, unter anderem die Zugabe von herkömmlichen carbonatbasierten Elektrolyten, niedermolekularen Polymeren sowie keramischen Fullstoffen. Dieser Aufsatz gibt einen Überblick uber den aktuellen Stand der Forschung zu ternären Polymerelektrolyten, also ionenleitenden Systemen aus einem Polymer und zwei Salzen, eines mit Lithiumkation, das andere mit zusätzlichen Anionen, die das Polymer plastifizieren. Weiterhin werden Grundlagen zu den Wechselwirkungen in Polymerelektrolyten diskutiert, um Überlegungen zu den Herausforderungen und Möglichkeiten von Lithiummetallbatterien anzuregen.
Copper(I) has become the preferred metal to catalyze the β-boration of α,β-unsaturated carbonyl compounds, and now we demonstrate that easily accessible monodentate chiral ligands, such as ...phosphoramidites and phosphites, can be convenient alternative ligands to induce asymmetry in the enantioselective version of this reaction, particularly in the β-boration of α,β-unsaturated imines.
Abstract
Mucins are a large family of heavily O-glycosylated proteins that cover all mucosal surfaces and constitute the major macromolecules in most body fluids. Mucins are primarily defined by ...their variable tandem repeat (TR) domains that are densely decorated with different O-glycan structures in distinct patterns, and these arguably convey much of the informational content of mucins. Here, we develop a cell-based platform for the display and production of human TR O-glycodomains (~200 amino acids) with tunable structures and patterns of O-glycans using membrane-bound and secreted reporters expressed in glycoengineered HEK293 cells. Availability of defined mucin TR O-glycodomains advances experimental studies into the versatile role of mucins at the interface with pathogenic microorganisms and the microbiome, and sparks new strategies for molecular dissection of specific roles of adhesins, glycoside hydrolases, glycopeptidases, viruses and other interactions with mucin TRs as highlighted by examples.
Campylobacter is the most common cause of foodborne bacterial illness worldwide. Faecal contamination of meat, especially chicken, during processing represents a key route of transmission to humans. ...There is a lack of insight into the mechanisms driving C. jejuni growth and survival within hosts and the environment. Here, we report a detailed analysis of C. jejuni fitness across models reflecting stages in its life cycle. Transposon (Tn) gene-inactivation libraries were generated in three C. jejuni strains and the impact on fitness during chicken colonisation, survival in houseflies and under nutrient-rich and -poor conditions at 4 °C and infection of human gut epithelial cells was assessed by Tn-insertion site sequencing (Tn-seq). A total of 331 homologous gene clusters were essential for fitness during in vitro growth in three C. jejuni strains, revealing that a large part of its genome is dedicated to growth. We report novel C. jejuni factors essential throughout its life cycle. Importantly, we identified genes that fulfil important roles across multiple conditions. Our comprehensive screens showed which flagella elements are essential for growth and which are vital to the interaction with host organisms. Future efforts should focus on how to exploit this knowledge to effectively control infections caused by C. jejuni.
Streptophytes are best known as the clade containing the teeming diversity of embryophytes (land plants).1,2,3,4 Next to embryophytes are however a range of freshwater and terrestrial algae that bear ...important information on the emergence of key traits of land plants. Among these, the Klebsormidiophyceae stand out. Thriving in diverse environments—from mundane (ubiquitous occurrence on tree barks and rocks) to extreme (from the Atacama Desert to the Antarctic)—Klebsormidiophyceae can exhibit filamentous body plans and display remarkable resilience as colonizers of terrestrial habitats.5,6 Currently, the lack of a robust phylogenetic framework for the Klebsormidiophyceae hampers our understanding of the evolutionary history of these key traits. Here, we conducted a phylogenomic analysis utilizing advanced models that can counteract systematic biases. We sequenced 24 new transcriptomes of Klebsormidiophyceae and combined them with 14 previously published genomic and transcriptomic datasets. Using an analysis built on 845 loci and sophisticated mixture models, we establish a phylogenomic framework, dividing the six distinct genera of Klebsormidiophyceae in a novel three-order system, with a deep divergence more than 830 million years ago. Our reconstructions of ancestral states suggest (1) an evolutionary history of multiple transitions between terrestrial-aquatic habitats, with stem Klebsormidiales having conquered land earlier than embryophytes, and (2) that the body plan of the last common ancestor of Klebsormidiophyceae was multicellular, with a high probability that it was filamentous whereas the sarcinoids and unicells in Klebsormidiophyceae are likely derived states. We provide evidence that the first multicellular streptophytes likely lived about a billion years ago.
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•Comprehensive phylogenomic analyses for 38 taxonomically diverse Klebsormidiophyceae•Three-order system for the Klebsormidiophyceae, resilient land colonizers•Deep divergence, 830 million years ago—long before embryophytes emerged•Evidence that multicellularity emerged in streptophytes about a billion years ago
Bierenbroodspot et al. use comprehensive phylogenomic analyses to propose a three-order system for Klebsormidiophyceae, streptophyte algae that colonize terrestrial habitats but are distantly related to land plants. They trace the occurrence of multicellular growth that, based on molecular dating, might have emerged about a billion years ago.
SARS-CoV-2 has been identified as the causative agent of a global outbreak of respiratory tract disease (COVID-19). In some patients the infection results in moderate to severe acute respiratory ...distress syndrome (ARDS), requiring invasive mechanical ventilation. High serum levels of IL-6, IL-10 and an immune hyperresponsiveness referred to as a 'cytokine storm' have been associated with poor clinical outcome. Despite the large numbers of COVID-19 cases and deaths, information on the phenotype and kinetics of SARS-CoV-2-specific T cells is limited. Here, we studied 10 COVID-19 patients who required admission to an intensive care unit and detected SARS-CoV-2-specific CD4
and CD8
T cells in 10 out of 10 and 8 out of 10 patients, respectively. We also detected low levels of SARS-CoV-2-reactive T cells in 2 out of 10 healthy controls not previously exposed to SARS-CoV-2, which is indicative of cross-reactivity due to past infection with 'common cold' coronaviruses. The strongest T-cell responses were directed to the spike (S) surface glycoprotein, and SARS-CoV-2-specific T cells predominantly produced effector and Th1 cytokines, although Th2 and Th17 cytokines were also detected. Furthermore, we studied T-cell kinetics and showed that SARS-CoV-2-specific T cells are present relatively early and increase over time. Collectively, these data shed light on the potential variations in T-cell responses as a function of disease severity, an issue that is key to understanding the potential role of immunopathology in the disease, and also inform vaccine design and evaluation.
The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT ...strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc(r)) in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc(r) genes. Fecal fosmid libraries were functionally screened for Tc(r), and further PCR-screened for specific Tc(r) genes. Tc(r) fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tc(r), although encoded by different genes and organisms. Tc(r) organisms in the mother consisted mainly of Firmicutes and Bacteroidetes, and the main gene detected was tet(O), although tet(W) and tet(X) were also found. Identical Tc(r) gene sequences were present in different bacterial families and even phyla, which may indicate horizontal transfer within the maternal GIT. In the infant library, Tc(r) was present exclusively in streptococci carrying tet(M), tet(L) and erm(T) within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within the infant's gut. In addition, although not found in the infant metagenomic library, tet(O) and tet(W) could be detected in the uncloned DNA purified from the infant fecal sample. This is the first study to reveal the diversity of Tc(r) bacteria in the human gut, to detect a likely transmission of antibiotic resistance from mother to infant GITs and to indicate the possible occurrence of gene transfers among distantly related bacteria coinhabiting the GIT of the same individual.
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