Synergistic effect of composition gradient and morphology on the catalytic activity of amorphous FeCoNi-LDH.

The rational design of electrocatalysts with well-designed compositions and structures for the oxygen evolution reaction (OER) is promising and challenging. Herein, we developed a novel strategy - a one-step double-cation etching sedimentation equilibrium strategy - to synthesize amorphous hollow Fe-Co-Ni layered double hydroxide nanocages with an outer surface of vertically interconnected ultrathin nanosheets (Fe-Co-Ni-LDH), which primarily depends on the in situ etching sedimentation equilibrium of the template interface. This unique vertical nanosheet-shell hierarchical nanostructure possesses enhanced charge transfer, increased active sites, and favorable kinetics during electrolysis, resulting in superb electrocatalytic performance for the oxygen evolution reaction (OER). Specifically, the Fe-Co-Ni-LDH nanocages exhibited remarkable OER activity in alkaline electrolytes and achieved a current density of 100 mA cm-2 at a low overpotential of 272 mV with excellent stability. This powerful strategy provides a profound molecular-level insight into the control of the morphology and composition of 2D layered materials.

[Characteristics of dark-adapted and light-adapted oscillatory potentials in human electroretinogram].

OBJECTIVE: To characterize dark-adapted and light-adapted oscillatory potentials (OPs) in human electroretinogram (EGR) elicited by flashing light stimulation of the same intensity. METHODS: Dark- and light-adapted ERGs of normal eyes were studied. The frequency spectra of the extracted dark-adapted OPs and light-adapted OPs were analyzed by a fast Fourier transform. The peak frequency, latency and total power of the OPs were determined. RESULTS: The averaged peak frequency, latency, and power of the dark-adapted OPs was 125.3∓9.93 Hz, 41.7∓3.56 ms, and 9.25∓5.55 (V·s)(2), as compared with 79.5∓6.79 Hz, 50.8∓5.36 ms, and 3.56∓2.18 (V·s)(2) for light-adapted Ops, respectively, showing significant differences in the parameters between dark- and light-adapted Ops (P<0.001). CONCLUSIONS: Compared with dark-adapted OPs, light-adapted Ops is characterized by a lower peak frequency and a lower power with a prolonged latency.

[The expression pattern and possible function of microRNA-34a in neurons].

Using Northern blotting, ISH and FISH, we demonstrated miR-34a expresses with aging in the brain of rhesus monkey and rat. Correspondingly, the same trend was found in the primary cultures of cortical neurons. Moreover, we found that induction of miR-34a led to neuronal apoptosis by targeting BCL-2. Our study suggests that miR-34a may play critical roles in neuronal development and ageing.

[Knockdown and overexpression of miR-219 lead to embryonic defects in zebrafish development].

MicroRNAs (miRNAs) are important post-transcriptional modulators of gene expression, which have been implicated in many physiological and pathological processes. In this study, we found that miR-219 expressed since early segmentation stages (16s) in spinal cord and mid-, hindbrain in zebrafish using Northern blotting and whole mounts ISH technologies. Moreover, knockdown or overexpression of miR-219 led to specific embryonic defects. Furthermore, TUNEL assay showed that overexpression of miR-219 induced significant cell apoptosis in the head and tail of zebrafish. Our study suggested that miR-219 may play an important role in zebrafish embryonic development.