Cooperation between holey N-doped carbon and Ni nanoparticles as an efficient electrocatalyst for the hydrogen evolution reaction.

Exploring non-noble and high-performance metal catalysts to replace platinum-based catalysts for the hydrogen evolution reaction (HER) electrochemical water splitting significantly alleviates environmental pollution and the energy crisis. However, the synthetic approaches of such electrocatalysts are generally complex and challenging for large-scale production. Herein, a facile and green solid-state synthesis of Ni nanoparticles decorated with N-doped porous carbon is presented.

Development and clinical validation of a microfluidic-based platform for CTC enrichment and downstream molecular analysis.

Background: Although many CTC isolation and detection methods can provide information on cancer cell counts, downstream gene and protein analysis remain incomplete. Therefore, it is crucial to develop a technology that can provide comprehensive information on both the number and profile of CTC.

Methods: In this study, we developed a novel microfluidics-based CTC separation and enrichment platform that provided detailed information about CTC.

Effect of 40 Hz light flicker on behaviors of adult C57BL/6J mice.

40 Hz light flicker can activate multiple brain regions of wild-type mice. However, there are no systematic studies on the behavioral effects of 40 Hz light flicker on wild-type mice. Adult wild-type C57BL/6J mice were treated with 40 Hz light flicker (200 lx, 40 Hz, 1 h/day for 3 weeks) to evaluate its effects on several behaviors, including mood, locomotor activity, memory, social interaction, mechanical pain, and sense of smell.

Characterization of the trophic transfer and fate of methylmercury in the food web of Zhalong Wetland, Northeastern China.

The transfer and fate of methylmercury (MeHg) in typical components, such as sediment, sediment-inhabiting animals, pelagic fish, and three large waterfowls, namely, red-crowned crane (Grus japonensis), mallard (Anas platyrhynchos), and oriental stork (Ciconia boyciana), of the ecosystem in China's Zhalong Wetland were examined using equivalence-based mass balance model. The biomagnification degree of MeHg increased on the species at the high trophic level of the system. Hence, elevated MeHg concentration (3.

Core-Shell-Shell Upconversion Nanoparticles with Enhanced Emission for Wireless Optogenetic Inhibition.

Recent advances in upconversion technology have enabled optogenetic neural stimulation using remotely applied optical signals, but limited success has been demonstrated for neural inhibition by using this method, primarily due to the much higher optical power and more red-shifted excitation spectrum that are required to work with the appropriate inhibitory opsin proteins. To overcome these limitations, core-shell-shell upconversion nanoparticles (UCNPs) with a hexagonal phase are synthesized to optimize the doping contents of ytterbium ions (Yb) and to mitigate Yb-associated concentration quenching. Such UCNPs' emission contains an almost three-fold enhanced peak around 540-570 nm, matching the excitation spectrum of a commonly used inhibitory opsin protein, halorhodopsin.

Regeneration of cortical tissue from brain injury by implantation of defined molecular gradient of semaphorin 3A.

Despite great efforts in the exploration of therapeutic strategies for treating brain injuries, it is still challenging to regenerate neural tissues and to restore the lost function within an injured brain. In this report, we employed a tissue engineering approach to regenerate cortical tissue from brain injury by implantation of defined semaphorin 3A (Sema3A) gradient packaged in a hydrogel based device. Over a thirty-day recovery period, the implanted Sema3A gradient was sufficient to induce substantial migration of neural progenitor cells to the hydrogel and to promote differentiation of these cells for neuroregeneration at the injury site.

Tetherless near-infrared control of brain activity in behaving animals using fully implantable upconversion microdevices.

Many nanomaterials can be used as sensors or transducers in biomedical research and they form the essential components of transformative novel biotechnologies. In this study, we present an all-optical method for tetherless remote control of neural activity using fully implantable micro-devices based on upconversion technology. Upconversion nanoparticles (UCNPs) were used as transducers to convert near-infrared (NIR) energy to visible light in order to stimulate neurons expressing different opsin proteins.