Developing nano-or atom-scale Pt-based electrocatalysts for hydrogen evolution reaction (HER) is of considerable importance to mitigate the issues associated with low abundance of Pt. Here, a protocol for constructing a hierarchical Pt-MXene-single-walled carbon nanotubes' (SWCNTs) heterostructure for HER catalysts is presented. In the heterostructure, highly active nano/atom-scale metallic Pt is immobilized on Ti 3 C 2 T x MXene flakes (MXene@Pt) that are connected with conductive SWCNTs' network. The hierarchical heterostructure is constructed by filtrating a mixed colloidal suspension containing MXene@Pt and SWCNTs. Taking the advantages of the hydrophilicity and reducibility of MXene, the MXene@Pt colloidal suspension is prepared by spontaneously reducing Pt cations into metallic Pt without additional reductants or post-treatments. The so-fabricated hierarchical HER catalysts, in the form of membrane, show high stability during 800 h operation, a high volume current density of up to 230 mA cm −3 at −50 mV versus reversible hydrogen electrode (RHE) and a low overpotential of −62 mV versus RHE at the current density of −10 mA cm −2. This solution-processed strategy offers a simple, efficient, yet scalable approach to construct stable and efficient HER catalysts. Given the properties and the structure-activity relationships of the hierarchical Pt-MXene-SWCNTs' heterostructure, other MXenes probably show greater promise in HER electrocatalysis.

Successful pregnancy in placental mammals substantially depends on the establishment of maternal immune tolerance to the semi-allogenic fetus. Disorders in this process are tightly associated with adverse pregnancy outcomes including recurrent miscarriage (RM). However, an in-depth understanding of the systematic and decidual immune environment in RM remains largely lacking. In this study, we utilized single-cell RNA-sequencing (scRNA-seq) to comparably analyze the cellular and molecular signatures of decidual and peripheral leukocytes in normal and unexplained RM pregnancies at the early stage of gestation. Integrative analysis identifies 22 distinct cell clusters in total, and a dramatic difference in leukocyte subsets and molecular properties in RM cases is revealed. Specifically, the cytotoxic properties of CD8 + effector T cells, nature killer (NK), and mucosal-associated invariant T (MAIT) cells in peripheral blood indicates apparently enhanced pro-inflammatory status, and the population proportions and ligand–receptor interactions of the decidual leukocyte subsets demonstrate preferential immune activation in RM patients. The molecular features, spatial distribution, and the developmental trajectories of five decidual NK (dNK) subsets have been elaborately illustrated. In RM patients, a dNK subset that supports embryonic growth is diminished in proportion, while the ratio of another dNK subset with cytotoxic and immune-active signature is significantly increased. Notably, a unique pro-inflammatory CD56 + CD16 + dNK subset substantially accumulates in RM decidua. These findings reveal a comprehensive cellular and molecular atlas of decidual and peripheral leukocytes in human early pregnancy and provide an in-depth insight into the immune pathogenesis for early pregnancy loss.

Flexible in-plane solid-state supercapacitor fabricated by CVD-grown metallic VSe2nanosheets presents excellent mechanical stability and high energy density.

The use of precious metals in many areas, such as printed circuit boards, catalysts, and targeted drugs, is increasing due to their unique physical and chemical properties, but their recovery remains a great challenge. Here, we report a sandwiched Ti 3 C 2 T x MXene/carbon nanotube (CNT) hybrid membrane, where the CNT isolates and supports the MXene sheets, which act as a reducing agent. The hybrid membrane shows excellent ability to capture precious metal ions in solution with a high flux. The water permeability of the membrane reaches 437.6 L m −2 h −1 bar −1 (2.46 × 10 −18 m 2 ), about 202 times higher than that of a pure Ti 3 C 2 T x membrane, and captures 99.8% Au(III) from a solution with an extremely low concentration of 20 ppm. The desirable precious metal trapping capability of the Ti 3 C 2 T x −CNT film is due to the high redox activity of C−Ti−OH. This work provides an efficient way for the recovery of precious metal ions from wastewater.

In placental mammals, reproductive success, and maternal-fetal health substantially depend on a well-being placenta, the interface between the fetus and the mother. Disorders in placental cells are tightly associated with adverse pregnancy outcomes including preeclampsia (PE), fetal growth restriction, etc. MicroRNAs (miRNAs) represent small non-coding RNAs that regulate post-transcriptional gene expression and are integral to a wide range of healthy or diseased cellular proceedings. Numerous miRNAs have been detected in human placenta and increasing evidence is revealing their important roles in regulating placental cell behaviors. Recent studies indicate that placenta-derived miRNAs can be released to the maternal circulation via encapsulating into the exosomes, and they potentially target various maternal cells to provide a hormone-like means of intercellular communication between the mother and the fetus. These placental exosome miRNAs are attracting more and more attention due to their differential expression in pregnant complications, which may provide novel biomarkers for prediction of the diseases. In this review, we briefly summarize the current knowledge and the perspectives of the placenta-derived miRNAs, especially the exosomal transfer of placental miRNAs and their pathophysiological relevance to PE. The possible exosomal-miRNA-targeted strategies for diagnosis, prognosis or therapy of PE are highlighted.

Kinetic effects resulting from the two-fluid physics play a crucial role in the fast collisionless reconnection, which is a process to explosively release massive energy stored in magnetic fields in space and astrophysical plasmas. In-situ observations in the Earth's magnetosphere provide solid consistence with theoretical models on the point that kinetic effects are required in the collisionless reconnection. However, all the observations associated with solar wind reconnection have been analyzed in the context of magnetohydrodynamics (MHD) although a lot of solar wind reconnection exhausts have been reported. Because of the absence of kinetic effects and substantial heating, whether the reconnections are still ongoing when they are detected in the solar wind remains unknown. Here, by dual-spacecraft observations, we report a solar wind reconnection with clear Hall magnetic fields. Its corresponding Alfvenic electron outflow jet, derived from the decouple between ions and electrons, is identified, showing direct evidence for kinetic effects that dominate the collisionless reconnection. The turbulence associated with the exhaust is a kind of background solar wind turbulence, implying that the reconnection generated turbulence has not much developed.

Uterine spiral artery remodeling is a crucial event during pregnancy to provide enough blood supply to maternal-fetal interface and meet the demands of the growing fetus. Along this process, the dynamic change and the fate of spiral artery vascular smooth muscle cells (SPA-VSMCs) have long been debatable. In the present study, we analyzed the cell features of SPA-VSMCs at different stages of vascular remodeling in human early pregnancy, and demonstrated the progressively morphological change of SPA-VSMCs at un-remodeled, remodeling and fully remodeled stages, indicating the extravillous trophoblast (EVT)-independent and EVT-dependent phases of SPA-VSMC dedifferentiation. In vitro experiments in VSMC cell line revealed the efficient roles of decidual stromal cells, decidual NK cells (dNK), decidual macrophages and EVTs in inducing VSMCs dedifferentiation. Importantly, the potential transformation of VSMC toward CD56+ dNKs was displayed by IF-ISH-PLA and ChIP assays for H3K4dime modification in Myh11 promoter region. The findings clearly illustrate a cascade regulation of the progressive dedifferentiation of SPA-VSMCs by multiple cell types in uterine decidual niche, and provide new evidences to reveal the destination of SPA-VSMCs during vascular remodeling.

Objectives: During human pregnancy, the endothelial cells of the uterine spiral arteries (SPA) are extensively replaced by a subtype of placental trophoblasts, endovascular extravillous trophoblasts (enEVTs), thus establishing a placental-maternal circulation. On this pathway, foetus-derived placental villi and enEVTs bath into the maternal blood that perfuses along SPA being not attacked by the maternal lymphocytes. We aimed to reveal the underlying mechanism of such immune tolerance. Methods:In situ hybridization, immunofluorescence, ELISA and FCM assay were performed to examine TGF-β1 expression and distribution of regulatory T cells (Tregs) along the placental-maternal circulation route. The primary enEVTs, interstitial extravillous trophoblasts (iEVTs) and decidual endothelial cells (dECs) were purified by FACS, and their conditioned media were collected to treat naïve CD4 + T cells. Treg differentiation was measured by FLOW and CFSE assays. Results:We found that enEVTs but not iEVTs or dECs actively produced TGF-β1. The primary enEVTs significantly promoted naïve CD4 + T-cell differentiation into immunosuppressive FOXP3 + Tregs, and this effect was dependent on TGF-β1. In recurrent spontaneous abortion (RSA) patients, an evidently reduced proportion of TGF-β1producing enEVTs and their ability to educate Tregs differentiation were observed. Conclusions:Our findings demonstrate a unique immune-regulatory characteristic of placental enEVTs to develop immune tolerance along the placental-maternal circulation. New insights into the pathogenesis of RSA are also suggested.