Three-dimensional CeO_(2)@carbon-quantum-dots scaffold modified with Au nanoparticles on flexible substrates for high performance gas sensing at room temperature

High-performance gas sensing materials operated at room temperature(RT) are attractive for a variety of real-time gas monitoring applications,especially with the excellent durability and flexibility of wearable sensor.The constructing heterostructure is one of the significant approaches in design strategies of sensing materials.This heterostructure effectively increases the active site for improving sensing performance and decreasing energy consumption.Herein,the heterostructure of Au nanoparticles modified CeO_(2)@carbon-quantum-dots(Au/CeO_(2)@CQDs) with a three-dimensional(3D) scaffold structure are successfully synthesized by an effective strategy,which can apply for preparing flexible gas sensor.The gas sensing properties of Au/CeO_(2)@CQDs based on flexible substrate are obtained under long-term repeated NO_(2) exposure at RT.Meanwhile,the long-term mechanical stability of this gas sensing device is also detected after different bending cycles.The Au/CeO_(2)@CQDs based on flexible substrate sensor exhibits excellent performance,including higher sensitivity(47.2),faster response(18 s)and recovery time(22 s) as well as longer-term stability than performance of pure materials.The obtained sensor also reveals outstanding mechanical flexibility,which is only a tiny response fluctuation(8.1%) after 500 bending/relaxing cycles.Therefore,our study demonstrates the enormous potential of this sensing materials for hazardous gas monitoring in future portable and wearable sensing platform.

Applications of carbon nanotubes in high performance lithium ion batteries

The development of lit;triton ion batteries （LIBs） relies on the improvement in the performance of electrode materials with higher capacity, higher rate capability, and longer cycle lift;. In this review article, the recent advances in carbon nanotube （CNT） anodes, CNT-based composite electrodes, and CNT current collectors for high performance LIBs are concerned. CNT has received considerable attentions as a candidate material for the LIB applications. In addition to a possible choice for anode, CNT has been recognized as a solution in improving the performance of the state-of-the-art electrode materials. The CNT-based composite electrodes can be fabricated by mechanical or chem- ical approaches. Owing to the large aspect ratio and the high electrical conductivity, CNTs at very low loading can lead to an efficient conductive network. The excellent mechanical strength suggests the great potential in forming a structure scaffold to accommodate nano-sized electrode materials. Accordingly, the incorporation of CNTs will enhance the conductivity of the composite electrodes, mitigatc the agglomeration problem, decrease the dependence on inactive binders, and improve the clcctrochenfical properties of both anode and cathode materials remarkably. Freestanding CNT network can be used as lightweight current collectors to increase the overall energy density of LIBs. Finally, research perspectives for exploiting CNTs in high-performance LIBs are discussed.

Eularian wall film model for predicting dynamic cell culture process to evaluate scaffold design in a perfusion bioreactor

In tissue engineering field,it is important to develop a suitable numerical model to evaluate scaffold geometry design.The experimental evaluation of the effect of each specific scaffold parameter on tissue regeneration requires large cost and long time expend.Dynamic cell culture is commonly used for generating tissues which could replace damaged tissues.A perfusion bioreactor model is developed which is able to simulate dynamic cell culture,to evaluate scaffold quality.The wall-film model is used to simulate cell attachment with the assumption that cells could be seen as liquid drops.In the process of cell attachment,the cells could impinge to a solid surface and form a liquid film which were considered as cell attached on the scaffold surface.Two types of cell-scaffold interactions were involved in numerical models including trap model and Stanton-Rutland(Cell impinge model—CIM)model.For trap model,all cells impinged the scaffold are seen as attached.For Stanton-Rutland model,four regimes of cell-scaffold interaction are involved in the cell attachment,including stick,rebound,spread,and splash,and only stick and spread are seen as attached.By comparison with two different numerical methods,the results showed that CIM model result is more related to the experimental results than trap model,which indicated that four regimes of cell-scaffold interaction occurred in cell attachment process.By evaluating two different geometry scaffold's cells seeding by these two models,the results further indicated that this model are able to use for assessing the scaffold design.

Discovery of dipeptidyl peptidase Ⅳ(DPP4) inhibitors based on a novel indole scaffold

Dipeptidyl peptidase Ⅳ（DPP4） inhibitors are proven in the treatment of type 2 diabetes.We designed and synthesized a series of novel indole compounds that selectively inhibit the activity of DPP4 over dipeptidyl peptidase 9（DPP9）（〉200 fold）.We further co-crystallized DPP4 with indole sulfonamide（compound 1） to confirm a proposed binding mode.Good metabolic stability of the indole compounds represents another positive attribute for further development.