Schwann cell cultures from human fetal dorsal root ganglia

BACKGROUND： Previous studies have used many methods for in vitro Schwann cells （SCs） cultures and purification, such as single cell suspension and cytosine arabinoside. However, it has been difficult to obtain sufficient cellular density, and the procedures have been quite tedious. OBJECTIVE： To investigate the feasibility of culturing high-density SCs using fetal human dorsal root ganglion tissue explants. DESIGN, TIME AND SETTING： Cell culture and irnmunohistochernistry were performed at the Central Laboratory of Kunrning General Hospital of Chinese PLA between March 2001 and October 2008. MATERIALS： Culture media containing 10% fetal bovine serum, as well as 0.2% collagenase and 0.25% trypsin were purchased from Gibco, USA; mouse anti-human S-100 monoclonal antibody and goat anti-mouse IgG labeled with horseradish peroxidase were provided by Beijing Institute of Biological Products, China. METHODS： Primarily cultured SCs were dissociated from dorsal root ganglia of human aborted fetuses at 4 6 months pregnancy. Following removal of the dorsal root ganglion perineurium, the ganglia were dissected into tiny pieces and digested with 0.2% collagenase and 0.25% trypsin （volume ratio 1：1）, then explanted and cultured. SC purification was performed with 5 rnL 10% fetal bovine serum added to the culture media, followed by differential adhesion. MAIN OUTCOME MEASURES： SCs morphology was observed under inverted phase contrast light microscopy. SC purity was evaluated according to percentage of S-100 immunostained cells. RESULTS： SCs were primarily cultured for 5 6 days and then subcultured for 4 5 passages. The highly enriched SC population reached 〉 95% purity and presented with normal morphology. CONCLUSION： A high purity of SCs was obtained with culture methods using human fetal dorsal root ganglion tissue explants.

Fast processing nylon mesh by surface diffuse atmospheric plasma for large-area oil/water separation

In recent years,numerous studies have been reported for oil/water separation,such as superoleophilic materials for oil absorption and underwater superoleophobic membranes for continuous separation.However,for the recovery of oil slick pollution on near-shore ocean surface caused by various reasons,large area and fast availability of used materials are needed to be considered.Herein,we report an efficient and environmentally friendly method to fast process nylon mesh by surface diffuse atmospheric plasma(SDAP)for large-area oil/water separation.Nylon mesh is funcionalized by atmospheric plasma to generate micro/nano composite structures on the surface,resulting in superhydrophilicity and underwater superoleophobicity within only seconds.The pre-wetted modified nylon mesh can achieve high efficiency(>99.9%)and circulating water flux(~30,000 L·m^(-2)·h^(-1)),with high intrusion pressure(~3 kPa)and universality in oil/water separation.Regular plasma unconditionally generated in the atmosphere with the merit of efficiently functionalizing surface has the potential of large-area materials treatment.This study might take one step further for large-area industrial oily wastewater recovery and even oil slicks collection in near-shore water bodies.

Anomalous Pore-Density Dependence in Nanofluidic Osmotic Power Generation

Osmotic power generation in biomimetic nanofluidic systems has attracted considerable research interest owing to the enhanced performance and long-term stability. Towards practical applications, when extrapolating the materials from single-nanopore to multi-pore membranes, conventional viewpoint suggests that, to gain high electric power density, the porosity should be as high as possible. However, recent experimental observations show that the commonly-used linear amplification method largely overestimates the actual performance, particularly at high pore density. Herein, we provide a theoretical investigation to understand the reason. We find a counterintuitive pore-density dependence in high porosity nanofluidic systems that, once the pore density approaches more than lx109 pores/cm2, the overall output electric power goes down with the increasing pore density. The excessively high pore density impairs the charge selectivity and induces strong ion concentration polarization, which undermines the osmotic power generation process. By optimizing the geometric size of the nanopores, the performance degradation can be effectively relieved. These findings clarify the origin of the unsatisfactory performance of the current osmotic nanofluidic power sources, and provide insights to further optimize the device.

Enhanced photo-driven ion pump through silver nanoparticles decorated graphene oxide membranes

Biology systems harvest solar energy to regulate ions and molecules precisely across cell membrane that is essential to maintain their life sustainability.Recently,artificial light-driven directional ion transport through graphene oxide membranes has been established,where the membrane converts light power into a transmembrane motive force.Herein,we report a silver nanoparticles decorated graphene oxide membranes for enhanced photo-driven ionic transport.Asymmetric light stimulated charge carrier dynamics,such as advanced light absorption efficiency,extended lifetime and efficient separation of photo-excited charge carriers,are account for the ion-driven force enhancement.Based on metal nanoparticles decoration,the concept of the guest-interactions of plasmon-enhanced photo-driven ion transport in two-dimentional layered membranes will stimulate broad researches in sensing,energy storage and conversion and water treatment.

Highly rectified ion transport through 2D WSe2/MoS2 bi-layered membranes

Two-dimensional（2 D） nanofluidic systems provide a highly efficient way to integrate a huge amount of cascading lamellar nanofluidic channels into macroscopic membrane materials for practical use in, for example, molecular separation, water treatment, and energy storage. Besides the well-studied graphenebased materials, other 2 D nanomaterials, such as the transition metal dichalcogenides（TMDCs）, are expected as promising alternatives. Here, we report strong ionic current rectification（ICR） effect found in Mo S2/WSe2 bi-layered membrane structure. The preferential direction for ion transport is from the WSe2 layers to the Mo S2 layers. The maximum ICR ratio approaches 35 at intermediate electrolyte concentration. More intriguingly, by exchanging the deposition order of the Mo S2 and WSe2 layers, the observed ICR effect can be reversed. These evidences justify that the highly rectified ion transport phenomenon results from the asymmetry in the reconstructed 2 D layered materials. This work is the first discovery of ICR effect in 2 D nanofluidic heterostructures, and provides further opportunities for innovative nanofluidic devices and materials.