Artificial Post-Cycled Structure Modulation Towards Highly Stable Li-Rich Layered Cathode.

High-capacity Li-rich layered oxides (LLOs) suffer from severe structure degradation due to the utilization of hybrid anion- and cation-redox activity. The native post-cycled structure, composed of progressively densified defective spinel layer (DSL) and intrinsic cations mixing, is deemed as the hindrance of the rapid and reversible de/intercalation of Li+ . Herein, the artificial post-cycled structure consisting of artificial DSL and inner cations mixing is in situ constructed, which would act as a shield against the irreversible oxygen emission and undesirable transition metal migration by suppressing anion redox activity and modulating cation mixing. Eventually, the modified DSL-2% Li-rich cathode demonstrates remarkable electrochemical properties with a high discharge capacity of 187 mAh g-1 after 500 cycles at 2 C, and improved voltage stability. Even under harsh operating conditions of 50 °C, DSL-2% can provide a high discharge capacity of 168 mAh g-1 after 250 cycles at 2 C, which is much higher than that of pristine LLO (92 mAh g-1 ). Furthermore, the artificial post-cycled structure provides a novel perspective on the role of native post-cycled structure in sustaining the lattice structure of the lithium-depleted region and also provides an insightful universal design principle for highly stable intercalated materials with anionic redox activity.

High-quality trials and pharmacological studies needed as translational evidence for the application of traditional Chinese medicine Lianhua Qingwen against COVID-19.

Traditional Chinese medicine (TCM) has been employed as complementary medication against COVID-19 in China since 2020. Two years since then, TCM, with Lianhua Qingwen (LHQW) as an example, has been included in every version of official clinical protocol guidelines. Recently, LHQW is even distributed to general public at risk but not yet infected. Such common application and widely claimed positive outcome among mild to moderate patients were accompanied by a number of published studies on antiviral, antiinflammatory, and immune modulatory potential using either in vitro or animal models. However, aside from retrospective understanding and open-labeled clinical trials with relatively small subject size, major gap in conclusive proof for efficacy and safety remains due to the lack of double-blind placebo-controlled studies and comprehensive pharmacodynamic and kinetic investigations. This is also supported by a recent WHO expert meeting on this subject, which acknowledged the potential benefits of TCM in mild-moderate cases, while recommended more rigorous studies to further understand effect size, application implications, and outcome determinants. Therefore, there is an urgent need to address the exact role TCM like LHQW could play in COVID-19 management from translational evidence-based perspective. High-quality clinical trials, pharmacological studies, and real-world data from recent outbreak are recommended.

A severe atherosclerosis mouse model on the resistant NOD background.

Atherosclerosis is a complex disease affecting arterial blood vessels and blood flow that could result in a variety of life-threatening consequences. Disease models with diverged genomes are necessary for understanding the genetic architecture of this complex disease. Non-obese diabetic (NOD) mice are highly polymorphic and widely used for studies of type 1 diabetes and autoimmunity. Understanding atherosclerosis development in the NOD strain is of particular interest as human atherosclerosis on the diabetic and autoimmune background has not been successfully modeled. In this study, we used CRISPR/Cas9 genome editing to genetically disrupt apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) expression on the pure NOD background, and compared phenotype between single-gene-deleted mice and double-knockout mutants with reference to ApoE-deficient C57BL/6 mice. We found that genetic ablation of Ldlr or Apoe in NOD mice was not sufficient to establish an atherosclerosis model, in contrast to ApoE-deficient C57BL/6 mice fed a high-fat diet (HFD) for over 12 weeks. We further obtained NOD mice deficient in both LDLR and ApoE, and assessed the severity of atherosclerosis and immune response to hyperlipidemia in comparison to ApoE-deficient C57BL/6 mice. Strikingly, the double-knockout NOD mice treated with a HFD developed severe atherosclerosis with aorta narrowed by over 60% by plaques, accompanied by destruction of pancreatic islets and an inflammatory response to hyperlipidemia. Therefore, we succeeded in obtaining a genetic model with severe atherosclerosis on the NOD background, which is highly resistant to the disease. This model is useful for the study of atherosclerosis in the setting of autoimmunity.

Speed genome editing by transient CRISPR/Cas9 targeting and large DNA fragment deletion.

Genetic engineering of cell lines and model organisms has been facilitated enormously by the CRISPR/Cas9 system. However, in cell lines it remains labor intensive and time consuming to obtain desirable mutant clones due to the difficulties in isolating the mutated clones and sophisticated genotyping. In this study, we have validated fluorescent protein reporter aided cell sorting which enables the isolation of maximal diversity in mutant cells. We further applied two spectrally distinct fluorescent proteins DsRed2 and ECFP as reporters for independent CRISPR/Cas9 mediated targeting, which allows for one-cell-one-well sorting of the mutant cells. Because of ultra-high efficiency of the CRISPR/Cas9 system with dual reporters and large DNA fragment deletion resulting from independent loci cleavage, monoclonal mutant cells could be easily identified by conventional PCR. In the speed genome editing method presented here, sophisticated genotyping methods are not necessary to identify loss of function mutations after CRISPR/Cas9 genome editing, and desirable loss of function mutant clones could be obtained in less than one month following transfection.

A point mutation in the extracellular domain of CD4 completely abolishes CD4 T cell development in C57BL/6 mouse.

In this study, we performed ENU mutagenesis and multi-parameter flow cytometric analysis in C57BL/6 mice to uncover novel genes or alleles regulating immune cell development. We identified a novel mutant allele of Cd4 gene which completely blocked development of a major subset of T cells named CD4 T cell. Our data for the first time showed experimentally in mice the critical role of the first extracellular domain, by obtaining mice with a loss of function mutation from Ile to Asn at the position 99 of CD4 (I99N). Interestingly, such CD4I99N mutant protein can be expressed on the surface of human cells, and the mRNA stability could be also affected by this point mutation, suggesting that absence of CD4 T cells in mice rooted in the deficiency in function and expression of CD4. In addition, we used this novel CD4 T cell deficient model as recipient mice for adoptive transfer experiment, and showed that it could be an optimal model for study of CD4 T cells.