•Mg-ion batteries may address future large scale mobile and stationary device needs.•Recent research on cathodes for Mg-ion is reviewed.•Chemical and structural details of the cathode materials are ...emphasized.•Particular strategies which may lead to future research initiatives are amplified.
Rechargeable magnesium-ion batteries are a promising candidate technology to address future electrical energy storage needs of large scale mobile and stationary devices, due to the high environmental abundance of magnesium metal and divalent character of magnesium ion. With the recent increase in reports discussing cathode materials for magnesium-ion batteries, it is instructive to assess recent research in order to provide inspiration for future research. This review is a summary of the different chemistries and structures of the materials developed for magnesium ion cathodes. The particular strategies which may lead to future research initiatives are amplified.
A bottleneck for the large-scale application of today's batteries is low lithium storage capacity, largely due to the use of intercalation-type electrodes that allow one or less electron transfer per ...redox center. An appealing alternative is multi-electron transfer electrodes, offering excess capacity, which, however, involves conversion reaction; according to conventional wisdom, the host would collapse during the process, causing cycling instability. Here, we report real-time observation of topotactic reaction throughout the multi-electron transfer process in magnetite, unveiled by in situ single-crystal crystallography with corroboration of first principles calculations. Contradicting the traditional belief of causing structural breakdown, conversion in magnetite resembles an intercalation process-proceeding via topotactic reaction with the cubic close packed oxygen-anion framework retained. The findings from this study, with unique insights into enabling multi-electron transfer via topotactic reaction, and its implications to the cyclability and rate capability, shed light on designing viable multi-electron transfer electrodes for high energy batteries.
Background and Aims
Chronic HBV infection is a major health problem worldwide. Currently, the first‐line treatment for HBV is nucleos(t)ide analogs or interferons; however, efficient therapeutic ...approaches that enable cure are lacking. Therefore, anti‐HBV agents with mechanisms distinct from those of current drugs are needed. Sodium taurocholate cotransporting polypeptide (NTCP) was previously identified as an HBV receptor that is inhibited by several compounds. Farnesoid X receptor (FXR) activation also inhibits NTCP function.
Approach and Results
In this study, we investigated the inhibitory effect of bile acid (BA) derivatives—namely obeticholic acid (OCA), 6α‐ethyl‐24‐nor‐5β‐cholane‐3α,7α,23‐triol‐23 sulfate sodium salt (INT‐767; a dual agonist of FXR and Takeda G protein‐coupled receptor TGR5), and 6α‐ethyl‐23(S)‐methyl‐cholic acid (INT‐777; a TGR5 agonist)—3‐(2,6‐dichlorophenyl)‐4‐(3′‐carboxy‐2‐chlorostilben‐4‐yl)oxymethyl‐5‐isopropylisoxazole (GW4064; a FXR agonist), cyclosporin A, and irbesartan. OCA and INT‐777 suppressed HBV infection in HepG2‐human NTCP‐C4 cells. Interestingly, INT‐767 showed potent inhibition by attaching to HBV particles rather than binding to NTCP. As an entry inhibitor, INT‐767 was stronger than various natural BAs. Furthermore, in chimeric mice with humanized liver, INT‐767 markedly delayed the initial rise of HBsAg, HBeAg, and HBV DNA and reduced covalently closed circular DNA. The strong inhibitory effect of INT‐767 may be due to the cumulative effect of its ability to inhibit the entry of HBV and to stimulate FXR downstream signaling, which affects the postentry step.
Conclusions
Our results suggest that BA derivatives, particularly INT‐767, are prospective candidate anti‐HBV agents. Clarifying the underlying mechanisms of BA derivatives would facilitate the development of anti‐HBV agents.
Several APOBEC3 proteins, particularly APOBEC3D, APOBEC3F, and APOBEC3G, induce G-to-A hypermutations in HIV-1 genome, and abrogate viral replication in experimental systems, but their relative ...contributions to controlling viral replication and viral genetic variation in vivo have not been elucidated. On the other hand, an HIV-1-encoded protein, Vif, can degrade these APOBEC3 proteins via a ubiquitin/proteasome pathway. Although APOBEC3 proteins have been widely considered as potent restriction factors against HIV-1, it remains unclear which endogenous APOBEC3 protein(s) affect HIV-1 propagation in vivo. Here we use a humanized mouse model and HIV-1 with mutations in Vif motifs that are responsible for specific APOBEC3 interactions, DRMR/AAAA (4A) or YRHHY/AAAAA (5A), and demonstrate that endogenous APOBEC3D/F and APOBEC3G exert strong anti-HIV-1 activity in vivo. We also show that the growth kinetics of 4A HIV-1 negatively correlated with the expression level of APOBEC3F. Moreover, single genome sequencing analyses of viral RNA in plasma of infected mice reveal that 4A HIV-1 is specifically and significantly diversified. Furthermore, a mutated virus that is capable of using both CCR5 and CXCR4 as entry coreceptor is specifically detected in 4A HIV-1-infected mice. Taken together, our results demonstrate that APOBEC3D/F and APOBEC3G fundamentally work as restriction factors against HIV-1 in vivo, but at the same time, that APOBEC3D and APOBEC3F are capable of promoting viral diversification and evolution in vivo.
Solid electrolytes (SEs) are a promising, safe alternative to liquid electrolytes in high energy density batteries, but low conductivity issues remain a challenge. Herein, a lithium iodide based ...solid electrolyte (SE) was improved by reducing particle size via several processing methods, i.e. grinding and/or sonication. Particle size was reduced from 5 ± 1 µm to 2.0 ± 0.2 µm, resulting in an order of magnitude increase in ionic conductivity, from 7.7×10−8 to 6.1×10−7 S cm-1, at room temperature. Improved conductivity is attributed to an increased number of grain boundaries and defects, enabling ion transport and better mixing with the electrolyte additive, 1:2 lithium iodide: 3-hydroxypropionitrile (LiI(HPN)2). 3D confocal Raman spectroscopy in conjunction with non-negative matrix factorization (NMF) analysis determined the degree of HPN aggregation was lessened in the sample with smallest particle size. This LiI SE was utilized in a self-forming Li/I2 battery, where reduced particle size (improved conductivity) led to significantly reduced overpotential, allowing the coulombic efficiency to reach 100% in the first cycle. Furthermore, a more stable electrochemical response was achieved when cycled at higher current densities.
We present numerical models of earthquake cycles on a strike‐slip fault that incorporate laboratory‐derived power law rheologies with Arrhenius temperature dependence, viscous dissipation, conductive ...heat transfer, and far‐field loading due to relative plate motion. We use these models to explore the evolution of stress, strain, and thermal regime on “geologic” timescales (∼106–107 years), as well as on timescales of the order of the earthquake recurrence (∼102 years). Strain localization in the viscoelastic medium results from thermomechanical coupling and power law dependence of strain rate on stress. For conditions corresponding to the San Andreas fault (SAF), the predicted width of the shear zone in the lower crust is ∼3–5 km; this shear zone accommodates more than 50% of the far‐field plate motion. Coupled thermomechanical models predict a single‐layer lithosphere in case of “dry” composition of the lower crust and upper mantle, and a “jelly sandwich” lithosphere in case of “wet” composition. Deviatoric stress in the lithosphere in our models is relatively insensitive to the water content, the far‐field loading rate, and the fault strength and is of the order of 102 MPa. Thermomechanical coupling gives rise to an inverse correlation between the fault slip rate and the ductile strength of the lithosphere. We show that our models are broadly consistent with geodetic and heat flow constrains from the SAF in Northern California. Models suggest that the regionally elevated heat flow around the SAF may be at least in part due to viscous dissipation in the ductile part of the lithosphere.
Key Points
Numerical models of earthquake cycles with nonlinear rheology
Strain localization due to thermomechanical coupling
Comparisons with geodetic and heat flow data, predictions of stress and strain
Epitaxial LiCoO2 (LCO) thin films of different orientations were fabricated by pulsed laser deposition (PLD) in order to model single-crystal behavior of intercalation cathodes during electrochemical ...reactions. This paper demonstrates that (1) epitaxial growth of LCO on a single crystal Nb-doped SrTiO3 (Nb:STO) of different orientations occurs with a single orientation relationship; (2) surface morphology of the LCO films is established by the morphology of coalescing grains during island growth mode, whereas morphology of the grains can be visualized as different cuts from a cube with low-energy {104}R-LCO surfaces; (3) the films consist of predominately trigonal R-LiCoO2 phase, with a small fraction of the occasionally present cubic c-LixCoO2 phase; (4) cyclic voltammetry measurements have determined rectification at interface between LCO and Nb:STO causing bias on the oxidation part of cycling, thus preventing full cycling.
•Electron microscopy of growth and crystallography of epitaxial LiCoO2 thin films.•Films consist of trigonal LiCoO2 phase with a small fraction of spinel c-LixCoO2.•Surface morphology is established by the low-energy {104} faceted coalescing grains.•Cyclic voltammetry determined rectification at the LCO/STO interface.
High vaccine reactogenicities may reflect stronger immune responses, but the epidemiological evidence for coronavirus disease 2019 (COVID-19) vaccines is sparse and inconsistent. We observed that a ...fever of ≥38℃ after two doses of the BNT162b2 vaccine was associated with higher severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike IgG titers.
The rate-limiting step in lithiation/delithiation of solid-state cathode materials is not well understood. Phase-transformation reaction rate, lithium ion diffusion coefficient, and lithium ion ...concentration have all been shown to affect the discharge and charge performance. All three parameters are affected by the crystal structure and crystallinity of the cathode. In this paper, lithium trivanadate (LiV3O8) is selected as a representative cathode for all solid-state thin-film batteries because of its glass ceramic properties at different annealing temperatures, where the crystallinity and preferred orientation vary. The intermediate temperature-treated thin films outperform both the amorphous and the most crystalline thin films. By correlating the cell polarization with both the diffusion coefficient and the lithium ion concentration at different states of charge, we gain insights into the electrochemical performance of the glass ceramic LiV3O8 cathode.
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