Commensal Microbiome Expands T gamma delta 17 Cells in the Lung and Promotes Particulate Matter-Induced Acute Neutrophilia

Particulate matter (PM) induces neutrophilic inflammation and deteriorates the prognosis of diseases such as cardiovascular diseases, cancers, and infections, including COVID-19. Here, we addressed the role of gamma delta T cells and intestinal microbiome in PM-induced acute neutrophilia. gamma delta T cells are a heterogeneous population composed of T gamma delta 1, T gamma delta 2, T gamma delta 17, and naive gamma delta T cells (T gamma delta N) and commensal bacteria promote local expansion of T gamma delta 17 cells, particularly in the lung and gut without affecting their V gamma repertoire. T gamma delta 17 cells are more tissue resident than T gamma delta 1 cells, while T gamma delta N cells are circulating cells. IL-1R expression in T gamma delta 17 cells is highest in the lung and they outnumber all the other type 17 cells such as Th17, ILC3, NKT17, and MAIT17 cells. Upon PM exposure, IL-1 beta-secreting neutrophils and IL-17-producing T gamma delta 17 cells attract each other around the airways. Accordingly, PM-induced neutrophilia was significantly relieved in gamma delta T- or IL-17-deficient and germ-free mice. Collectively, these findings show that the commensal microbiome promotes PM-induced neutrophilia in the lung via T gamma delta 17 cells.11Ysciescopu

Triboelectric Hydrogen Gas Sensor with Pd Functionalized Surface

Palladium (Pd)-based hydrogen (H2) gas sensors have been widely investigated thanks to its fast reaction and high sensitivity to hydrogen. Various sensing mechanisms have been adopted for H2 gas sensors; however, all the sensors must be powered through an external battery. We report here an H2 gas sensor that can detect H2 by measuring the output voltages generated during contact electrification between two friction surfaces. When the H2 sensor, composed of Pd-coated ITO (indium tin oxide) and PET (polyethylene Terephthalate) film, is exposed to H2, its output voltage is varied in proportion to H2 concentration because the work function (WF) of Pd-coated surface changes, altering triboelectric charging behavior. Specifically, the output voltage of the sensor is gradually increased as exposing H2 concentration increases. Reproducible and sensitive sensor response was observed up 1% H2 exposure. The approach introduced here can easily be adopted to development of triboelectric gas sensors detecting other gas species

Triboelectric Charging Sequence Induced by Surface Functionalization as a Method To Fabricate High Performance Triboelectric Generators

Two different materials, apart from each other in a triboelectric series, are required to fabricate high performance triboelectric generators (TEGs). Thus, it often limits the choices of materials and causes related processing issues for TEGs. To address this issue, we report a simple surface functionalization method that can effectively change the triboelectric charging sequence of the materials, broadening material choices and enhancing the performance of TEGs. Specifically, we functionalized the surfaces of the polyethylene terephthalate (PET) films either with poly-l-lysine solution or trichloro(1<i>H</i>,1<i>H</i>,2<i>H</i>,2<i>H</i>-perfluorooctyl) silane (FOTS). Consequently, the PET surfaces were modified to have different triboelectric polarities in a triboelectric series. The TEGs, fabricated using this approach, demonstrated the maximum <i>V</i>_{open‑circuit} (<i>V</i>_oc) of ∼330 V and <i>J</i>_{short‑circuit} (<i>J</i>_sc) of ∼270 mA/m², respectively, at an applied force of 0.5 MPa. Furthermore, the functionalized surfaces of TEGs demonstrated superior stability during cyclic measurement over 7200 cycles, maintaining the performance even after a month. The approach introduced here is a simple, effective, and cost-competitive way to fabricate TEGs, which can also be easily adopted for various surface patterns and device structures