基于流体驱动的软体机器人研究进展

基于流体驱动的软体机器人目前已得到广泛的研究与应用。根据其发展现状,对流体驱动方式进行了综合对比,总结了软体机器人在结构设计、材料制作、试验分析中的方法,并对其面临的问题、未来发展的挑战进行了分析。

分析化学实验多元化教学模式改革与实践

创新实验教学模式是解决当前高校理工科类实验教学困境的重要途径。总结分析化学实验教学面临的难题,依托基础性、设计型和科研型实验为教学内容,建立以微视频在线课前预习、翻转课堂的课中学习和软件联用处理实验结果的新型实验教学方法。这种多元化教学模式能有效提高学生的学习主动性和创新能力。以基础性实验和研究型实验为案例,阐述多元化教学模式的具体应用,为理工科类实验教学改革提供研究依据。

Effects of Method for Returning Straw to Field on Soil Properties,Straw Decomposition and Nutrient Release

[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Academy of Agricultural Sciences as the experimental base,the effects of returning double-crop wheat and corn straw to field(Twm),returning single-crop corn straw to field(Tm),returning single-crop wheat straw to field(Tw)on soil temperature,water content,straw decomposition rate and nutrient release,soil organic matter and bulk density were studied systematically.[Results]Twm treatment could effectively alleviate the effects of meteorological conditions on soil temperature and water content.The decomposition rate of straw treated with Twm was 4.7%higher than that of Tm treatment,3.8%higher than that of Tw treatment,10.5%higher than that of Tm treatment,and the decomposition rate of straw showed a trend of"first fast,then slow and then fast".The release of nitrogen from straw was basically similar to that of straw decay,and the release of potassium and phosphorus increased at first and then remained basically unchanged.The release rate of potassium was the highest,followed by phosphorus and nitrogen.The content of soil organic matter in Twm treatment increased by 11.67%annually,an annual average of 0.998 g/kg.The soil bulk density of Twm treatment decreased by 0.058 g/cm^(3) annually,an annual average of 4.29%.The fundamental reason is that Twm treatment provides conditions(temperature,water content,nutrition)for microbial growth,reproduction,enzyme production and biochemical reaction,and increases the exchange capacity of soil and external water,heat,gas and fertilizer.[Conclusions]It is expected is to help people change their understanding of returning straw to field from"quick harvest"to"fertilizer transformation".

Peptide-RNA complexation-induced fluorescence“turn on”displacement assay for the recognition of small ligands targeting HIV-1 RNA

The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluorescence indicator displacement assays have been used to identify ligands that can inhibit the ReveRRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient ReveRRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive ReveRRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)propylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the ReveRRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The ReveRRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.

气动双稳态装置驱动的仿喷水推进乌贼结构软体机器人

基于双稳态结构跳变原理,设计了一种仿喷水推进乌贼结构软体机器人。首先,制作一种双稳态驱动装置,该装置随着气体周期性通断进行跳变,带动拨水薄膜产生往复运动,使得样机内部体积变化。其次,通过调节双稳态装置的驱动频率,使样机快速喷水、缓慢吸水形成动量差,推动样机向前运动。通过试验得出双稳态驱动装置跳变产生的推进力的变化规律,并将其应用到仿生乌贼的驱动中。最后,试验分析了双稳态装置跳变过程的运动特性,建立相应的力学模型,通过ABAQUS仿真软件对驱动装置的弯曲性能进行仿真分析,验证其弯曲性能。研究结果表明,样机在双稳态装置驱动下可以达到8.7 cm/s(约0.58倍样机身长/秒)的运动速度,具有一定的负重能力,展现出了优异的游动性能。

Electrochemical co-deposition of reduced graphene oxide-gold nanocomposite on an ITO substrate and its application in the detection of dopamine

The simultaneous deposition of rGO and gold nano structures has been achieved by electrodeposition from mixed solutions containing graphene oxide(GO)and a gold precursor.Scanning electron microscope(SEM),Raman spectroscopy and atomic force microscopy(AFM)have been employed to reveal the morphology,uniformity and practical stability of the nanocomposite films on the indium tin oxide(ITO)substrate.The AFM data showed heights of tens of nanometers of the nanocomposite,suggesting that multilayers of rGO with gold nanoparticles had been formed as a result of the electrochemical co-deposition.Differential pulse voltammetry(DPV),as a widely used analytical technique,has been carried out on the rGO-Au/ITO electrode for the quantitative detection of dopamine(DA).The detection limit(S/N=3)for the determination of DA was evaluated as 0.6μM.

Integrated transcriptome analysis of human iPS cells derived from a fragile X syndrome patient during neuronal differentiation

Fragile X syndrome(FXS) patients carry the expansion of over 200 CGG repeats at the promoter of fragile X mental retardation 1(FMR1), leading to decreased or absent expression of its encoded fragile X mental retardation protein(FMRP). However, the global transcriptional alteration by FMRP deficiency has not been well characterized at single nucleotide resolution, i.e., RNA-seq. Here,we performed in-vitro neuronal differentiation of human induced pluripotent stem(iPS) cells that were derived from fibroblasts of a FXS patient(FXS-iPSC). We then performed RNA-seq and examined the transcriptional misregulation at each intermediate stage during in-vitro differentiation of FXS-iPSC into neurons. After thoroughly analyzing the transcriptomic data and integrating them with those from other platforms, we found up-regulation of many genes encoding TFs for neuronal differentiation(WNT1, BMP4,POU3F4, TFAP2 C, and PAX3), down-regulation of potassium channels(KCNA1, KCNC3, KCNG2, KCNIP4, KCNJ3, KCNK9,and KCNT1) and altered temporal regulation of SHANK1 and NNAT in FXS-iPSC derived neurons, indicating impaired neuronal differentiation and function in FXS patients. In conclusion, we demonstrated that the FMRP deficiency in FXS patients has significant impact on the gene expression patterns during development, which will help to discover potential targeting candidates for the cure of FXS symptoms.