Current understanding of ELF4 deficiency: a novel inborn error of immunity.

BACKGROUND: ELF4 deficiency has been recently recognized as a novel disorder within the spectrum of inborn errors of immunity (IEIs), specifically categorized as a "disease of immune dysregulation." Cases of this condition, reported by our team and others, are very limited worldwide. As such, our current knowledge of this new disease remains preliminary. This review aims to provide a brief overview of the clinical manifestations, pathogenesis, and treatment strategies for this novel IEI. DATA SOURCES: A comprehensive review was conducted after an extensive literature search in the PubMed/Medline database and websites concerning transcriptional factor ELF4 and reports concerning patients with ELF4 deficiency. Our search strategy was "ELF4 OR ETS-related transcription factor Elf-4 OR EL4-like factor 4 OR myeloid Elf-1-like factor" as of the time of manuscript submission. RESULTS: The current signature manifestations of ELF4 deficiency disorder are recurrent and prolonged oral ulcer, abdominal pain, and diarrhea in pediatric males. In some cases, immunodeficiency and autoimmunity can also be prominent. Targeted Sanger sequencing or whole exome sequencing can be used to detect variation in ELF4 gene. Western blotting for ELF4 expression of the patient's cells can confirm the pathogenic effect of the variant. To fully confirm the pathogenicity of the variant, further functional test is strongly advised. Glucocorticoid and biologics are the mainstream management of ELF4 deficiency disorder. CONCLUSIONS: Pediatric males presenting with recurring ulcerations in digestive tract epithelium with or without recurrent fever should be suspected of DEX. When atypical presentations are prominent, variations in ELF4 gene should be carefully evaluated functionally due to the complex nature of ELF4 function. Experience of treating DEX includes use of glucocorticoid and biologics and more precise treatment needs more patients to identify and further mechanistic study.

Elimination of Intragrain Defect to Enhance the Performance of FAPbI3 Perovskite Solar Cells by Ionic Liquid.

Ionic liquids have been widely used to improve the efficiency and stability of perovskite solar cells (PSCs), and are generally believed to passivate defects on the grain boundaries of perovskites. However, few studies have focused on the relevant effects of ionic liquids on intragrain defects in perovskites which have been shown to be critical for the performance of PSCs. In this work, the effect of ionic liquid 1-hexyl-3-methylimidazolium iodide (HMII) on intragrain defects of formamidinium lead iodide (FAPbI3) perovskite is investigated. Abundant {111}c intragrain planar defects in pure FAPbI3 grains are found to be significantly reduced by the addition of the ionic liquid HMII, shown by using ultra-low-dose selected area electron diffraction. As a result, longer charge carrier lifetimes, higher photoluminescence quantum yield, better charge carrier transport properties, lower Urbach energy, and current-voltage hysteresis are achieved, and the champion power conversion efficiency of 24.09% is demonstrated. These observations suggest that ionic liquids significantly improve device performance resulting from the elimination of {111}c intragrain planar defects.

Eliminating Non-Corner-Sharing Octahedral for Efficient and Stable Perovskite Solar Cells.

The metal halide (BX6)4- octahedron, where B represents a metal cation and X represents a halide anion, is regarded as the fundamental structural and functional unit of metal halide perovskites. However, the influence of the way the (BX6)4- octahedra connect to each other has on the structural stability and optoelectronic properties of metal halide perovskite is still unclear. Here, the octahedral connectivity, including corner-, edge-, and face-sharing, of various CsxFA1-xPbI3 (0 ≤ x ≤ 0.3) perovskite films is tuned and reliably characterized through compositional and additive engineering, and with ultralow-dose transmission electron microscopy. It is found that the overall solar cell device performance, the charge carrier lifetime, the open-circuit voltage, and the current density-voltage hysteresis are all improved when the films consist of corner-sharing octahedra, and non-corner sharing phases are suppressed, even in films with the same chemical composition. Additionally, it is found that the structural, optoelectronic, and device performance stabilities are similarly enhanced when non-corner-sharing connectivities are suppressed. This approach, combining macroscopic device tests and microscopic material characterization, provides a powerful tool enabling a thorough understanding of the impact of octahedral connectivity on device performance, and opens a new parameter space for designing high-performance photovoltaic metal halide perovskite devices.