Thrust estimate method of an on-orbit Hall thruster using Hall drift current

In order to realize the thrust estimation of the Hall thruster during its flight mission,this study establishes an estimation method based on measurement of the Hall drift current.In this method,the Hall drift current is calculated from an inverse magnetostatic problem,which is formulated according to its induced magnetic flux density detected by sensors,and then the thrust is estimated by multiplying the Hall drift current with the characteristic magnetic flux density of the thruster itself.In addition,a three-wire torsion pendulum micro-thrust measurement system is utilized to verify the estimate values obtained from the proposed method.The errors were found to be less than 8%when the discharge voltage ranged from 250 V to 350 V and the anode flow rate ranged from 30 sccm to 50 sccm,indicating the possibility that the proposed thrust estimate method could be practically applied.Moreover,the measurement accuracy of the magnetic flux density is suggested to be lower than 0.015 mT and improvement on the inverse problem solution is required in the future.

Fabrication of super-elastic graphene aerogels by ambient pressure drying and application to adsorption of oils

Three-dimensional graphene-based aerogels have promising applications in oil adsorption and environmental restoration.However,current research of graphene-based aerogels is often hindered by high preparation cost,poor mechanical properties and low recycling efficiency.Here,superelastic graphene aerogel(SGA)was prepared through one-step freezing and twice hydrothermal reduction followed by drying under ambient pressure.The simple atmospheric drying provides a possibility for large-scale preparation of high performance graphene-based aerogels.The prepared SGA not only has the ability of highly repeatable compression rebound,but also exhibits excellent oil adsorption performance.And the overall performance of SGA is better than most of graphenebased aerogels prepared by freeze drying.After the SGA was cyclically compressed with 70%strain for 300 times,it can return to the original shape and height substantially.SGA retained about 90%of the initial adsorption capacity after 50 cycles of adsorption and compression regeneration for cyclohexane.

Universal chimeric Fcγreceptor T cells with appropriate affinity for IgG1 antibody exhibit optimal antitumor efficacy

Developing universal CARs with improved flexible targeting and controllable activities is urgently needed.While several studies have suggested the potential of CD16a in tandem with monoclonal antibodies to construct universal CAR-T cells,the weak affinity between them is one of the limiting factors for efficacy.Herein,we systematically investigated the impact of Fcγreceptor(FcγR)affinity on CAR-T cells properties by constructing universal CARs using Fcγreceptors with different affinities for IgG1 antibodies,namely CD16a,CD32a,and CD64.We demonstrated that the activities of these universal CAR-T cells on tumor cells could be redirected and regulated by IgG1 antibodies.In xenografted mice,64CAR chimeric Jurkat cells with the highest affinity showed significant antitumor effects in combination with herceptin in the HER2 low expression U251 MG model.However,in the CD20 high expression Raji model,64CAR caused excessive activation of CAR-T cells,which resulted in cytokine release syndrome(CRS)and the decline of antitumor activity,and 32CAR with a moderate affinity brought the best efficacy.Our work extended the knowledge about FcγR-based universal CAR-T cells and suggested that only the FcγRCAR with an appropriate affinity can offer the optimal antitumor advantages of CAR-T cells.

Andrographolide and Its Derivative Potassium Dehydrographolide Succinate Suppress PRRSV Replication in Primary and Established Cells via Differential Mechanisms of Action

Porcine reproductive and respiratory syndrome virus(PRRSV) continues to cause significant economic loss worldwide and remains a serious threat to the pork industry. Currently, vaccination strategies provide limited protection against PRRSV infection, and consequently, new antiviral strategies are urgently required. Andrographolide(Andro) and its derivative potassium dehydrographolide succinate(PDS) have been used clinically in China and other Asian countries as therapies for inflammation-related diseases, including bacterial and viral infections, for decades. Here, we demonstrate that Andro and PDS exhibit robust activity against PRRSV replication in Marc-145 cells and primary porcine alveolar macrophages(PAMs). The two compounds exhibited broad-spectrum inhibitory activities in vitro against clinically circulating type 2 PRRSV GD-HD, XH-GD, and NADC30-like HNhx strains in China. The EC_(50)values of Andro against three tested PRRSV strain infections in Marc-145 cells ranged from 11.7 to 15.3 lmol/L, with selectivity indexes ranging from 8.3 to10.8, while the EC_(50)values of PDS ranged from 57.1 to 85.4 lmol/L, with selectivity indexes ranging from 344 to 515.Mechanistically, the anti-PRRSV activity of the two compounds is closely associated with their potent suppression on NFj B activation and enhanced oxidative stress induced by PRRSV infection. Further mechanistic investigations revealed that PDS, but not Andro, is able to directly interact with PRRSV particles. Taken together, our findings suggest that Andro and PDS are promising PRRSV inhibitors in vitro and deserves further in vivo studies in swine.

Surface photodynamic ion sterilization of ITO-Cu_(2)O/ZnO preventing touch infection

Pathogenic microbial infections are threatening the people’s health and even life.The most common channel of infections can be caused by skin contact,especially hand touching facilities such as touching screen.In this work,Cu_(2)O covered with ZnO nanofilm was prepared on the surface of indium tin oxide conductive glass by electrodeposition and the followed atomic layer deposition process.This composite coating had a light transmittance of 71.5%,which met the light transmission needs of touch screen device.Electron spin resonance spectra showed that composite materials can generate more reactive oxygen species(ROS)than a single component under solar light irradiation.This was because a p-n junction with a built-in electric field was formed at the interface after Cu_(2)O contacting with ZnO.In the process of photocatalysis,photogenerated electrons and holes migrated at the interface driven by the built-in electric field,which promoted the separation of carriers.The antibacterial rate against Staphylococcus aureus reached 92.5%after 3 min of light irradiation with simulated sunlight due to the synergy of ROS and Cu ions,Zn ions.Therefore,this work may provide a potential method for antibacterial application of preventing hand touch infections.