153 research outputs found
Octopus - An Autonomous Wheeled Climbing Robot
This paper presents an innovative off-road wheeled mobile robot, named Octopus, able to deal autonomously with obstacles in rough terrain without getting stuck. To achieve such a performance, the robot is equipped with tilt sensors and tactile wheels. The sophisticated locomotion mechanism of Octopus has 8 motorized wheels and a total of 15 degrees of freedom (14 of them are motorized). A two-dimensional static model and a controller are proposed. The inputs of the controller are the contact points with ground, the geometric angles of the articulations, and the direction of the gravity field. The outputs of the controller are the torques for the wheels, the torques for the forearms, and the position set point for the body
"Hands-On Mechatronics": Problem-Based Learning for Mechatronics
The project "Hands-On Mechatronics" aims to develop a problem-based learning environment for mechatronics. This environment is based on four specific aspects: a mobile robot competition as motivation factor, a WEB environment as framework for all student, the SmartEASE robot as experimental platform and a good software environment for design and fast prototyping. The actual status of this concept is applied at the Swiss Federal Institute of Technology in Lausanne (EPFL) with participants coming from several schools of different levels. We present the actual implementation of the concept "Hands-On Mechatronics", the hardware and software tools used and some problems found in our approach
A Modular Approach for a Family of Ground Mobile Robots
This paper deals with Epi.q, a family of mobile robots whose main characteristic is a wheel-legged hybrid locomotion. These multi-purpose robots can be successfully exploited for security and surveillance tasks. The document presents state of the art security robotics, the Epi.q mechanical architecture, the concept behind the robot driving unit, three prototypes and the design of a new on
Directional statistics and filtering using libDirectional
In this paper, we present libDirectional, a MATLAB library for directional statistics and directional estimation. It supports a variety of commonly used distributions on the unit circle, such as the von Mises, wrapped normal, and wrapped Cauchy distributions. Furthermore, various distributions on higher-dimensional manifolds such as the unit hypersphere and the hypertorus are available. Based on these distributions, several recursive filtering algorithms in libDirectional allow estimation on these manifolds. The functionality is implemented in a clear, well-documented, and object-oriented structure that is both easy to use and easy to extend
Surface-Initiated Polymer Brushes in the Biomedical Field: Applications in Membrane Science, Biosensing, Cell Culture, Regenerative Medicine and Antibacterial Coatings
The general anesthetic propofol induces ictal-like seizure activity in hippocampal mouse brain slices
GABAA receptors as molecular targets of general anesthetics: identification of binding sites provides clues to allosteric modulation
PurposeThe purpose of this review is to summarize current knowledge of detailed biochemical evidence for the role of γ-aminobutyric acid type A receptors (GABA(A)-Rs) in the mechanisms of general anesthesia.Principal findingsWith the knowledge that all general anesthetics positively modulate GABA(A)-R-mediated inhibitory transmission, site-directed mutagenesis comparing sequences of GABA(A)-R subunits of varying sensitivity led to identification of amino acid residues in the transmembrane domain that are critical for the drug actions in vitro. Using a photo incorporable analogue of the general anesthetic, R(+)etomidate, we identified two transmembrane amino acids that were affinity labelled in purified bovine brain GABA(A)-R. Homology protein structural modelling positions these two residues, αM1-11' and βM3-4', close to each other in a single type of intersubunit etomidate binding pocket at the β/α interface. This position would be appropriate for modulation of agonist channel gating. Overall, available information suggests that these two etomidate binding residues are allosterically coupled to sites of action of steroids, barbiturates, volatile agents, and propofol, but not alcohols. Residue α/βM2-15' is probably not a binding site but allosterically coupled to action of volatile agents, alcohols, and intravenous agents, and α/βM1-(-2') is coupled to action of intravenous agents.ConclusionsEstablishment of a coherent and consistent structural model of the GABA(A)-R lends support to the conclusion that general anesthetics can modulate function by binding to appropriate domains on the protein. Genetic engineering of mice with mutation in some of these GABA(A)-R residues are insensitive to general anesthetics in vivo, suggesting that further analysis of these domains could lead to development of more potent and specific drugs
Therapeutic efficacy in a hemophilia B model using a biosynthetic mRNA liver depot system
DNA-based gene therapy has considerable therapeutic potential, but the challenges associated with delivery continue to limit progress. Messenger RNA (mRNA) has the potential to provide for transient production of therapeutic proteins, without the need for nuclear delivery and without the risk of insertional mutagenesis. Here we describe the sustained delivery of therapeutic proteins in vivo in both rodents and non-human primates via nanoparticle-formulated mRNA. Nanoparticles formulated with lipids and lipid-like materials were developed for delivery of two separate mRNA transcripts encoding either human erythropoietin (hEPO) or factor IX (hFIX) protein. Dose-dependent protein production was observed for each mRNA construct. Upon delivery of hEPO mRNA in mice, serum EPO protein levels reached several orders of magnitude (>125 000-fold) over normal physiological values. Further, an increase in hematocrit (Hct) was established, demonstrating that the exogenous mRNA-derived protein maintained normal activity. The capacity of producing EPO in non-human primates via delivery of formulated mRNA was also demonstrated as elevated EPO protein levels were observed over a 72-h time course. Exemplifying the possible broad utility of mRNA drugs, therapeutically relevant amounts of human FIX (hFIX) protein were achieved upon a single intravenous dose of hFIX mRNA-loaded lipid nanoparticles in mice. In addition, therapeutic value was established within a hemophilia B (FIX knockout (KO)) mouse model by demonstrating a marked reduction in Hct loss following injury (incision) to FIX KO mice
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