A modular cable-driven humanoid arm with anti-parallelogram mechanisms and Bowden cables

This paper proposes a novel modular cable-driven humanoid arm with anti-parallelogram mechanisms(APMs)and Bowden cables.The lightweight arm realizes the advantage of joint independence and the rational layout of the driving units on the base.First,this paper analyzes the kinematic performance of the APM and uses the rolling motion between two ellipses to approximate a pure-circular-rolling motion.Then,a novel type of one-degree-of-freedom(1-DOF)elbow joint is proposed based on this principle,which is also applied to design the 3-DOF wrist and shoulder joints.Next,Bowden cables are used to connect the joints and their driving units to obtain a modular cable-driven arm with excellent joint independence.After that,both the forward and inverse kinematics of the entire arm are analyzed.Last,a humanoid arm prototype was developed,and the assembly velocity,joint motion performance,joint stiffness,load carrying,typical humanoid arm movements,and repeatability were tested to verify the arm performance.

Nasopharyngeal Local Transcriptional Profile upon SARS-CoV-2 Omicron BA.2.2 Breakthrough Infection

The Omicron variants have continued to cause severe acute respiratory syndrome coronavirus 2 infections.To better understand the anti-viral effects of vaccination on host-virus interactions during the outbreak of BA.2.2 Omicron,we conducted RNA-seq transcriptome analysis on nasopharyngeal swabs from COVID-19 patients in Shanghai.This study was performed on selected cases from unvaccinated,fully vaccinated,and booster groups with the same founder virus infection background.We observed predominant immune cell chemotaxis and interleukin-1 production,as well as mucosal keratinization and epidermis development,in unvaccinated patients.In contrast,fully vaccinated subjects exhibited an obvious T-cell activation in the local immune response,whereas B-cell activation was higher in booster-vaccinated cases.In conclusion,our findings suggest that full or booster vaccination provides better adaptive immunity and relieve inflammation at the nasopharyngeal site,thereby reducing the risk of cytokine storm during breakthrough infection.

嗜水气单胞菌zntR调控的生理功能及其机制研究

【目的】ZntR是一种金属调控蛋白,可催化锌外排基因的转录激活,防止细胞内二价Zn离子过量,但其对细菌生理功能的影响目前尚不清楚。【方法】本研究构建了嗜水气单胞菌ATCC7966(Aeromonas hydrophila,A.h)的zntR缺失株及补救株,对菌株的生物被膜形成能力、溶血活性、运动能力和响应金属离子胁迫等生理表型进行评估。【结果】敲除zntR基因的菌株对锌和铬离子胁迫敏感、对钴离子胁迫耐受,并且生物被膜形成能力下降、运动能力增强,这些表型在其补救菌株中均能得到恢复。进一步利用DIA定量蛋白质组学技术比较野生株和zntR缺失株的蛋白表达差异,发现ZntR还可能参与双组分系统、细菌的趋化性等代谢通路的调控。【结论】该研究结果可为今后深入探讨zntR转录因子参与细菌生理功能的调控机制提供理论依据。

嗜水气单胞菌ntrC调控的生理功能及其机制研究

【目的】NtrC是一种与DNA结合的转录调控因子,在激活氮同化基因的转录和维持氮源供应中具有重要作用,本研究拟探究其对嗜水气单胞菌生理功能的影响及其作用机理。【方法】本研究采用同源重组方法构建了嗜水气单胞菌ATCC 7966 ntrC的缺失株,并以野生株为对照,对缺失株的生理表型进行测定和分析,利用定量蛋白质组学技术比较野生株和ntrC缺失株的蛋白表达差异。【结果】发现敲除ntrC基因后,嗜水气单胞菌在缺氮、渗透压、重金属离子、氧化以及不同抗生素胁迫下的耐受性都发生显著变化,且这些表型在其补救菌株中均能得到恢复。定量蛋白质组学分析发现,野生株和ntrC缺失株的差异表达蛋白可能参与氨基酸生物合成、抗坏血酸和醛糖酸盐等代谢通路的调控。【结论】本研究阐明了ntrC在嗜水气单胞菌中的重要作用及其对细菌生物学功能的影响,探讨了ntrC直接或间接调控的蛋白与生理表型之间的联系,研究结果可为未来水产致病菌的防治提供理论支持。