A Resistance-Based Microfluidic Chip for Deterministic Single Cell Trapping Followed by Immunofluorescence Staining

Microchips are fundamental tools for single-cell analysis. Although various microfluidic methods have been developed for single-cell trapping and analysis, most microchips cannot trap single cells deterministically for further analysis. In this paper, we describe a novel resistance-based microfluidic chip to implement deterministic single-cell trapping followed by immunofluorescence staining based on the least flow resistance principle. The design of a large circular structure before the constriction and the serpentine structure of the main channel made the flow resistance of the main channel higher than that of the trapping channel. Since cells preferred to follow paths with lower flow resistance, this design directed cells into the capture sites and improved single-cell trapping efficiency. We optimized the geometric parameters using numerical simulations. Experiments using A549 and K562 cell lines demonstrated the capability of our chip with (82.7 ± 2.4)% and (84 ± 3.3)% single-cell trapping efficiency, respectively. In addition, cells were immobilized at capture sites by applying the pulling forces at the outlet, which reduced the cell movement and loss and facilitated tracking of the cell in real time during the multistep immunofluorescence staining procedure. Due to the simple operation, high-efficiency single-cell trapping and lower cell loss, the proposed chip is expected to be a potential analytical platform for single tumor cell heterogeneity studies and clinical diagnosis

Reactive template-derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H-2 energy-associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self-sacrificial template-engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt-aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well-designed CoP/CoO PNTs show Pt-like activity, with an overpotential of only 61 mV at 10 mA cm(-2) and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in-depth insights into the fundamental mechanisms of heterojunction-induced electronic regulation, which may pave the way for the rational design of advanced Earth-abundant electrocatalysts in the future

Reactive template-derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H-2 energy-associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self-sacrificial template-engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt-aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well-designed CoP/CoO PNTs show Pt-like activity, with an overpotential of only 61 mV at 10 mA cm(-2) and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in-depth insights into the fundamental mechanisms of heterojunction-induced electronic regulation, which may pave the way for the rational design of advanced Earth-abundant electrocatalysts in the future

Reactive template‐derived interfacial engineering of CoP/CoO heterostructured porous nanotubes towards superior electrocatalytic hydrogen evolution

Abstract The development of economical, efficient, and robust electrocatalysts toward the hydrogen evolution reaction (HER) is highly imperative for the rapid advancement of renewable H2 energy‐associated technologies. Extensive utilization of the heterointerface effect can endow the catalysts with remarkably boosted electrocatalytic performance due to the modified electronic state of active sites. Herein, we demonstrate deliberate crafting of CoP/CoO heterojunction porous nanotubes (abbreviated as CoP/CoO PNTs hereafter) using a self‐sacrificial template‐engaged strategy. Precise control over the Kirkendall diffusion process of the presynthesized cobalt–aspartic acid complex nanowires is indispensable for the formation of CoP/CoO heterostructures. The topochemical transformation strategy of the reactive templates enables uniform and maximized construction of CoP/CoO heterojunctions throughout all the porous nanotubes. The establishment of CoP/CoO heterojunctions could considerably modify the electronic configuration of the active sites and also improve the electric conductivity, which endows the resultant CoP/CoO PNTs with enhanced intrinsic activity. Simultaneously, the hollow and porous nanotube architectures allow sufficient accessibility of exterior/interior surfaces and molecular permeability, drastically promoting the reaction kinetics. Consequently, when used as HER electrocatalysts, the well‐designed CoP/CoO PNTs show Pt‐like activity, with an overpotential of only 61 mV at 10 mA cm−2 and excellent stability in 1.0 M KOH medium, exceeding those of the vast majority of the previously reported nonprecious candidates. Density functional theory calculations further substantiate that the construction of CoP/CoO heterojunctions enables optimization of the Gibbs free energies for water adsorption and H adsorption, resulting in boosted HER intrinsic activity. The present study may provide in‐depth insights into the fundamental mechanisms of heterojunction‐induced electronic regulation, which may pave the way for the rational design of advanced Earth‐abundant electrocatalysts in the future

Aircraft noise, like heat stress, causes cognitive impairments via similar mechanisms in male mice

To our knowledge, little evidence is available about effects of aircraft noise (AN), a non-chemical stressor, on cognitive function. Again, it is unknown whether or not the heat stress (HS)-induced cognitive deficits can be exacerbated by AN. The adult male mice were assigned to four groups: group 1 mice exposed to non-HS (24-26 °C 2 h daily for 4 consecutive days) and white noise (WN) (2 h daily for 4 consecutive days), group 2 mice exposed to WN and HS (32-34 °C 2 h daily for 4 consecutive days), group 3 mice exposed to AN and non-HS (2 h daily for 4 consecutive days) and group 4 mice exposed to AN and HS (2 h daily for consecutive 4 days). Cognitive function were determined by passive avoidance, Y-maze, Morris water maze, and novel object recognition tests. Gut barrier and blood-brain-barrier (BBB) permeability, upload of lipopolysaccharide (LPS) translocation, systemic and central inflammation, and stress reactions were examined. Heat stressed mice displayed both increased stress reactions and learning and memory loss. Heat stress also caused gut barrier hyperpermeability, increased upload of LPS translocation, systemic inflammation, BBB disruption and hippocampal neuroinflammation. Aircraft noise stressed mice did not display systemic inflammation but caused gut barrier hyperpermeability, increased upload of LPS translocation, increased stress reactions, BBB disruption, hippocampal neuroinflammation and cognitive deficits. Aircraft noise exposure further exacerbated the heat stress-induced cognitive deficits and its complications. Our data suggest that AN, like HS, causes cognitive impairments via similar mechanisms in male mice

Interfacial engineering Co and MnO within N,S co-doped carbon hierarchical branched superstructures toward high-efficiency electrocatalytic oxygen reduction for robust Zn-air batteries

Electronic regulation via interfacial formation is identified as a versatile strategy to improve the electrocatalytic activity. Herein, we report a feasible electrospinning-pyrolysis approach for the in-situ immobilization of Co/ MnO hetero-nanoparticles onto N,S co-doped carbon nanotubes/nanofiber-integrated hierarchical branched superstructures (abbreviated as Co/MnO@N,S-C NT/CNFs hereafter). The simultaneous realization of interfacial engineering and nanocarbon hybridization renders the fabricated Co/MnO@N,S-C NT/CNFs with abundant firmly anchored active sites, modified electronic configuration, improved electric conductivity, efficient mass transport pathways, and significantly reinforced stability. Profiting from the compositional synergy and architectural advantages, the Co/MnO@N,S-C NT/CNFs exhibit outstanding ORR activity, superior tolerance to methanol, and excellent long-term stability in KOH electrolyte. More encouragingly, as a proof-of-concept demonstration, the rechargeable aqueous and flexible all-solid-state Zn-air batteries using Co/MnO@N,S-C NT/NFs + RuO2 as the air-cathode afford higher power densities, larger specific capacities and superb cycling stability, outperforming the state-of-the-art Pt/C + RuO2 counterparts. This work demonstrates the great contribution of heterointerfaces for oxygen electrocatalysis

7,8-Dihydroxyflavone accelerates recovery of Brown-Sequard syndrome in adult female rats with spinal cord lateral hemisection

Background: 7,8-Dihydroxyflavone (DHF) mimicks the physiological action of brain-derived neurotrophic factor (BDNF). Since local BDNF delivery to the injured spinal cord enhanced diaphragmatic respiratory function, we aimed to ascertain whether DHF might have similar beneficial effects after Brown-Sequard Syndrome in a rat model of spinal cord lateral hemisection (HX) at the 9th thoracic (T9) vertebral level. Methods: Three sets of adult female rats were included: sham+vehicle group, T9HX+vehicle group and T9HX+DHF group. On the day of surgery, HX+DHF group received DHF (5 mg/kg) while HX+vehicle group received vehicle. Neurobehavioral function, morphology of motor neurons innervating the tibialis anterior muscle and the transmission in descending motor pathways were evaluated. Results: Adult female rats received T9 HX had paralysis and loss of proprioception on the same side as the injury and loss of pain and temperature on the opposite side. We found that, in this model of Brown-Sequard syndrome, reduced cord dendritic arbor complexity, reduced cord motoneuron numbers, enlarged cord lesion volumes, reduced motor evoked potentials, and cord astrogliosis and microgliosis were noted after T9HX. All of the above-mentioned disorders showed recovery by Day 28 after surgery. Therapy with DHF significantly accelerated the electrophysiological, histological and functional recovery in these T9HX animals. Conclusions: Our data provide a biological basis for DHF as a neurotherapeutic agent to improve recovery after a Brown-Sequard syndrome. Such an effect may be mediated by synaptic plasticity and glia-mediated inflammation in the spared lumbar motoneuron pools to a T9HX