We propose an in situ poling of vertically well-aligned piezoelectric nanowire arrays with preferential polarization orientation as highly sensitive self-powered sensors for monitoring vital signs.

Wide‐bandgap perovskites have great potential to enable high‐efficiency tandem photovoltaics by combining with the well‐established low‐bandgap absorbers. However, such wide‐bandgap perovskites are often necessarily constructed with a high Br content, and thus faced with issues of phase segregation–induced photoinstability and high defect density, severely hindering their photovoltaic performance. Herein, a remarkable boost of the stability and efficiency of wide‐bandgap perovskite solar cells (PSCs) is demonstrated by simply incorporating potassium ions. Experiments have shown the interstitial occupancy of potassium ions in the perovskite lattice and the formation of 2D K2PbI4 at the grain boundaries, both can reduce the trap density and inhibit ion migration, and thus suppress nonradiative recombination and photoinduced phase segregation. The average power conversion efficiency (PCE) of photovoltaic devices based on the perovskite with 40% Br is improved from 15.28% to 17.94%, among which the champion efficiency is 18.38% with an optimal 15% KI incorporation. Importantly, the champion open‐circuit voltage (Voc) remains unchanged (≈1.25 V) even when the bandgap reduces from 1.80 to 1.75 eV due to KI doping, effectively reducing the Voc deficit. In addition, the unencapsulated cells can sustain 94% of the initial PCE after 2000 h of storage in ambient atmosphere, affirming their outstanding stability.

Objective: To investigate the underlying mechanism of lncRNA myocardial infarction-associated transcript (MIAT) in hypoxic-ischemic (HI)-induced neonatal cerebral palsy. Materials and methods: Neonatal rat model of HI injury was established to detect the motor function. LncRNA MIAT, miR-211, glial cell line-derived neurotrophic factor (GDNF) and caspase-3 expressions were measured by qRT-PCR or western blot. The apoptosis of Neuro2A cells was detected by flow cytometry. RNA immunoprecipitation (RIP) and RNA pull-down assays were performed to confirm the interaction between MIAT and miR-211. Results: Compared with control group, lncRNA MIAT and GDNF were downregulated in striatal tissues of neonatal rats in HI group and oxygen glucose deprivation (OGD)-induced ischemic injury of Neuro2A cells, whereas miR-211 was up-regulated in striatal tissues of HI group and OGDinduced ischemic injury of Neuro2A cells. LncRNA MIAT interacted with miR-211, and lncRNA MIAT overexpression reduced neuron apoptosis through miR-211. Besides, GDNF expression was positively regulated by lncRNA MIAT and negatively regulated by miR-211 in Neuro2A cells. In vivo experiment proved MIAT promoted motor function and relieved HI injury. Conclusion: MIAT overexpression reduced apoptosis of Neuro2A cells through miR-211/GDNF, which relieved HI injury of neonatal rats.

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