RESUMO
Aqueous Zn-ion batteries (AZIBs) have attracted increasing attention in next-generation energy storage systems due to their high safety and economic. Unfortunately, the side reactions, dendrites and hydrogen evolution effects at the zinc anode interface in aqueous electrolytes seriously hinder the application of aqueous zinc-ion batteries. Here, we report a critical solvation strategy to achieve reversible zinc electrochemistry by introducing a small polar molecule acetonitrile to form a "catcher" to arrest active molecules (bound water molecules). The stable solvation structure of [Zn(H2O)6]2+ is capable of maintaining and completely inhibiting free water molecules. When [Zn(H2O)6]2+ is partially desolvated in the Helmholtz outer layer, the separated active molecules will be arrested by the "catcher" formed by the strong hydrogen bond N-H bond, ensuring the stable desolvation of Zn2+. The Zn||Zn symmetric battery can stably cycle for 2250 h at 1 mAh cm-2, Zn||V6O13 full battery achieved a capacity retention rate of 99.2% after 10,000 cycles at 10 A g-1. This paper proposes a novel critical solvation strategy that paves the route for the construction of high-performance AZIBs.
RESUMO
A wholly aromatic polypyrene was synthesized by direct chemical oxidative polymerization of pyrene with ferric chloride as oxidant in hexane/nitromethane. Successful synthesis of polypyrene was thoroughly confirmed by IR, UV/Vis, 1D (1)H NMR, 2D (1)H-(1)H COSY, 2D (1)H-(13)C HSQC, MALDI-TOF MS, elemental analysis, and X-ray diffraction methods. The results indicated that the polypyrene was formed mainly through dehydro coupling between 2- or 1- and 2'- or 1'-positions on pyrene rings having a degree of polymerization of around 24. The polypyrene was purified and then separated into THF-soluble (ca. 10 %) and THF-insoluble (ca. 90 %) fractions. Compared with insulating pyrene monomer, the polypyrene is a controllably conducting polymer that has low conductivity of 3.4x10(-8) S cm(-1) in its virgin state, moderate conductivity of 2.28x10(-4) S cm(-1) upon iodine doping, but much higher conductivity of up to 81.2 S cm(-1) after the insoluble polypyrene was heated up to 1300 degrees C in nitrogen with a high char yield of 70.6 %. In particular, the soluble polypyrene demonstrates much stronger visible color fluorescence and much lower toxicity than pyrene. The soluble polypyrene would be advantageous for detecting Fe(3+) with almost no interference of other metal ions. The soluble and insoluble polypyrene fractions have potential applications as intrinsically luminescent and highly conducting carbon materials, respectively.
RESUMO
OBJECTIVE: Regulatory T cells (Tregs) play an important role in T cells. CC chemokine receptor 5 is a highly expressed chemokine receptor in T cells. They play an important role in inflammation and immune response of stroke. METHODS: Flow cytometry measured Tregs and CCR5+ Tregs in the blood of patients. Univariate and multivariate logistic regression analysis were utilized to analyze the effect of Tregs and CCR5+ Tregs on the prognosis of ischemic stroke. Receiver operating characteristic (ROC) curve was used to assess predictive values for Treg cells and CCR5+ Tregs. RESULTS: Tregs in patients with severe ischemic stroke were higher than those in mild ischemic stroke (P < 0.05), while the expression of CCR5+ Tregs were reversed (P < 0.05). The results of univariate and multivariate logistics regression analysis showed that Tregs and CCR5+ Tregs had a good predictive effect on the prognosis of ischemic stroke. The ROC curve demonstrated that the combination of Tregs and CCR+ Tregs achieved a better prediction effect (AUC = 0.758; P < 0.001). CONCLUSIONS: The combination of Tregs and CCR5+ Tregs can be used as biomarkers for the prognosis of ischemic stroke.
Assuntos
AVC Isquêmico/sangue , AVC Isquêmico/diagnóstico por imagem , Receptores CCR5/sangue , Linfócitos T Reguladores/metabolismo , Idoso , Biomarcadores/sangue , Feminino , Citometria de Fluxo/métodos , Humanos , Masculino , Pessoa de Meia-Idade , PrognósticoRESUMO
For early detection and diagnosis of gastric cancer, a novel, highly sensitive detection of microRNA-378 was developed through rolling circle amplification and DNA-templated silver nanoclusters as a lable-free fluorescent probe. DNA-templated fluorescent silver nanoclusters (DNA/AgNCs) to make target signal cascade amplification were prepared and identified through their fluorescent spectrum. MiRNA-378 trigged rolling circle amplification to obtain the complementary sequence (cDNA) to combine with two DNA/AgNCs in the middle of a sandwich structure to induce the new fluorescent signal at a new wavelength. In the presence of microRNA-378, a large amount of RCA product cDNAs were hybridized with DNA/AgNCs as the fluorescence nanocluster beacon, resulting in fluorescence enhanced "turn-on" phenomenon. This study indicated that amplified fluorescence detection of microRNA-378 is a stable, low-cost, highly specific, and ultra-low as 1.07â¯fM detectability. The proposed approach of signal synergetic amplification facilitating the fluorescence detection microRNA shows great potential for potentially clinically diagnosis.