Docking system design and self-assembly control of distributed swarm flying robots

This paper presents a novel docking system design and the distributed self-assembly control strategy for a Distributed Swarm Flying Robot (DSFR). The DSFR is a swarm robot comprising many identical robot modules that are able to move on the ground, dock with each other and fly coordinately once self-assembled into a robotic structure. A generalized adjacency matrix method is proposed to describe the configurations of robotic structures. Based on the docking system and the adjacency matrix, experiments are performed to demonstrate and verify the self-assembly control strategy

The E3 Ubiquitin Ligase AMFR and INSIG1 Bridge the Activation of TBK1 Kinase by Modifying the Adaptor STING

SummaryStimulator of interferon genes (STING, also known as MITA, ERIS, or MPYS) is essential for host immune responses triggered by microbial DNAs. However, the regulatory mechanisms underlying STING-mediated signaling are not fully understood. We report here that, upon cytoplasmic DNA stimulation, the endoplasmic reticulum (ER) protein AMFR was recruited to and interacted with STING in an insulin-induced gene 1 (INSIG1)-dependent manner. AMFR and INSIG1, an E3 ubiquitin ligase complex, then catalyzed the K27-linked polyubiquitination of STING. This modification served as an anchoring platform for recruiting TANK-binding kinase 1 (TBK1) and facilitating its translocation to the perinuclear microsomes. Depletion of AMFR or INSIG1 impaired STING-mediated antiviral gene induction. Consistently, myeloid-cell-specific Insig1−/− mice were more susceptible to herpes simplex virus 1 (HSV-1) infection than wild-type mice. This study uncovers an essential role of the ER proteins AMFR and INSIG1 in innate immunity, revealing an important missing link in the STING signaling pathway

Asymmetric conformations of cleaved HIV-1 envelope glycoprotein trimers in styrene-maleic acid lipid nanoparticles

During virus entry, the pretriggered human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimer initially transits into a default intermediate state (DIS) that remains structurally uncharacterized. Here, we present cryo-EM structures at near-atomic resolution of two cleaved full-length HIV-1 Env trimers purified from cell membranes in styrene-maleic acid lipid nanoparticles without antibodies or receptors. The cleaved Env trimers exhibited tighter subunit packing than uncleaved trimers. Cleaved and uncleaved Env trimers assumed remarkably consistent yet distinct asymmetric conformations, with one smaller and two larger opening angles. Breaking conformational symmetry is allosterically coupled with dynamic helical transformations of the gp41 N-terminal heptad repeat (HR1N) regions in two protomers and with trimer tilting in the membrane. The broken symmetry of the DIS potentially assists Env binding to two CD4 receptors—while resisting antibody binding—and promotes extension of the gp41 HR1 helical coiled-coil, which relocates the fusion peptide closer to the target cell membrane

Revealing the link between gut microbiota and brain tumor risk: a new perspective from Mendelian randomization

BackgroundRecent studies have shown that gut microbiota may be related to the occurrence of brain tumors, but direct evidence is lacking. This study used the Mendelian randomization study (MR) method to explore the potential causal link between gut microbiota and brain tumors.MethodWe analyzed the genome-wide association data between 211 gut microbiota taxa and brain tumors, using the largest existing gut microbiota Genome-Wide Association Studies meta-analysis data (n=13266) and combining it with brain tumor data in the IEU OpenGWAS database. We use inverse-variance weighted analysis, supplemented by methods such as Mendelian randomization-Egger regression, weighted median estimator, simple mode, and weighted mode, to assess causality. In addition, we also conducted the Mendelian randomization-Egger intercept test, Cochran’s Q test, and Mendelian randomization Steiger directionality test to ensure the accuracy of the analysis. Quality control includes sensitivity analysis, horizontal gene pleiotropy test, heterogeneity test, and MR Steiger directionality test.ResultOur study found that specific gut microbial taxa, such as order Lactobacillales and family Clostridiaceae1, were positively correlated with the occurrence of brain tumors, while genus Defluviitaleaceae UCG011 and genus Flavonifractor were negatively correlated with the occurrence of brain tumors. The Mendelian randomization-Egger intercept test showed that our analysis was not affected by pleiotropy (P>0.05).ConclusionThis study reveals for the first time the potential causal relationship between gut microbiota and brain tumors, providing a new perspective for the prevention and treatment of early brain tumors. These findings may help develop new clinical intervention strategies and point the way for future research

Alternating-electric-field-enhanced reversible switching of DNA nanocontainers with pH

Macroscopically realizable applications of DNA-based molecular devices require individual molecules to cooperate with each other. However, molecular crowding usually introduces disorder to the system, thus jeopardizing the molecular cooperation and slowing down their functional performance dramatically. A challenge remaining in this field is to obtain both smarter response and better cooperation simultaneously. Here, we report a swift-switching DNA nanodevice that is enhanced by an alternating electric field. The device, self-assembled from folded four-stranded DNA motifs, can robustly switch between closed and open states in smart response to pH stimulus, of which the closed state forms a nanometer-height container that is impermeable to small molecules. This character was used to directly and non-specifically catch and release small molecules emulating mechanical hand in a controllable way. The alternating electric field was used to accelerate molecular cooperative motion during the device switching, which in turn shortened the closing time remarkably to thirty seconds

Design and Mechanical Properties Analysis of Variable Buffer-Force Planing Energy-Absorbing Device for Rail Vehicles

Collisions between rail transit vehicles are unavoidable. In order to alleviate the disaster caused by the collision, energy-absorbing and shock-absorbing materials are generally installed at the front end of the rail vehicle. In this paper, a variable buffer-force planing energy-absorbing device for rail transit vehicles was prepared. The buffer force was changed by length (Dx), angle (A) and thickness (W). First, we manufactured one type of material, and data were obtained through experimentation. Second, we used Ls-DYNA to simulate this material, and determined the accuracy between the simulation and the test. Third, various parameters of the material were simulated by Ls-DYNA. The results show that changing Dx greatly affects the performance of the material, W has no obvious effect on the performance, and A is important for the materials properties. Based on finite element simulation, the functional model relationship between the average force and various parameters was deduced. This lays the groundwork for the application of the variable buffer-force planing energy absorbing device

Research on Mechanical Properties of Origami Aluminum Honeycomb for Automobile Energy Absorbing Box

With the increasing number of automobiles on the road, passive safety has become a particularly important issue. In this paper, an energy-absorbing material, origami aluminum honeycomb, was manufactured by a welding process for use as an automobile energy absorbing box. The mechanical properties and deformation of welded origami aluminum honeycomb in three directions were studied through quasi-static and dynamic compression tests. The results show that the origami aluminum honeycomb had good mechanical energy absorption performance, and the optimal directions are identified. Combined with theoretical analysis, the errors between experiments and simulations are shown. The origami honeycomb structure was designed for use as an automobile energy absorbing box. Analysis shows that it could absorb at least 10% of the kinetic energy of a vehicle during a collision, and could play a role in protecting the interior of the vehicle

Article A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks

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Sambot: A self-assembly modular robot system

The design and structure of a self-assembly modular robot (Sambot) are presented in this paper. Each module has its own autonomous mobility and can connect with other modules to form robotic structures with different manipulation abilities. Sambot has a versatile, robust, and flexible structure. The computing platform provided for each module is distributed and consists of a number of interlinked microcontrollers. The interaction and connectivity between different modules is achieved through infrared sensors and Zigbee wireless communication in discrete state and control area network bus communication in robotic configuration state. A new mechanical design is put forth to realize the autonomous motion and docking of Sambots. It is a challenge to integrate actuators, sensors, microprocessors, power units, and communication elements into a highly compact and flexible module with the overall size of 80 mm 80 mm 102 mm. The work describes represents a mature development in the area of self-assembly distributed robotics. © 2010 IEEE