Publications by authors named "Schiebel P"

To navigate complex terrains, insects use diverse tarsal structures (adhesive pads, claws, spines) to reliably attach to and locomote across substrates. This includes surfaces of variable roughness and inclination, which often require reliable transitions from ambulatory to scansorial locomotion. Using bioinspired physical models as a means for comparative research, our study specifically focused on the diversity of tarsal spines, which facilitate locomotion via frictional engagement and shear force generation.

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Self-propelling organisms locomote via generation of patterns of self-deformation. Despite the diversity of body plans, internal actuation schemes and environments in limbless vertebrates and invertebrates, such organisms often use similar traveling waves of axial body bending for movement. Delineating how self-deformation parameters lead to locomotor performance (e.

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The purpose of this study was to evaluate the biodistribution of a platelet-derived exosome product (PEP), previously shown to promote regeneration in the setting of wound healing, in a porcine model delivered through various approaches. Exosomes were labeled with DiR far-red lipophilic dye to track and quantify exosomes in tissue, following delivery via intravenous, pulmonary artery balloon catheter, or nebulization in sus scrofa domestic pigs. Following euthanasia, far-red dye was detected by Xenogen IVUS imaging, while exosomal protein CD63 was detected by Western blot and immunohistochemistry.

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The transition from the lab to natural environments is an archetypal challenge in robotics. While larger robots can manage complex limb-ground interactions using sensing and control, such strategies are difficult to implement on small platforms where space and power are limited. The Harvard Ambulatory Microrobot (HAMR) is an insect-scale quadruped capable of effective open-loop running on featureless, hard substrates.

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Terrestrial organisms that use traveling waves to locomote must leverage heterogeneities to overcome drag on the elongate body. While previous studies illuminated how habitat generalist snakes self-deform to use rigid obstacles in the surroundings, control strategies for multi-component terrain are largely unknown. We compared the sand-specialist Chionactis occipitalis to a habitat generalist, Pantherophis guttatus, navigating a model terrestrial terrain-rigid post arrays on a low-friction substrate.

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Article Synopsis
  • * A new theory called surface resistive force theory (RFT) is developed to explain how these snakes' unique body shapes and movement patterns reduce the impact of the sand's memory effects, enhancing their ability to escape.
  • * The findings indicate that other snake species struggle with movement on similar substrates due to high lateral slipping and show potential improvements for designing all-terrain robots by understanding these locomotion challenges.
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Animals moving on and in fluids and solids move their bodies in diverse ways to generate propulsion and lift forces. In fluids, animals can wiggle, stroke, paddle or slap, whereas on hard frictional terrain, animals largely engage their appendages with the substrate to avoid slip. Granular substrates, such as desert sand, can display complex responses to animal interactions.

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Natural and artificial self-propelled systems must manage environmental interactions during movement. In complex environments, these interactions include active collisions, in which propulsive forces create persistent contacts with heterogeneities. Due to the driven and dissipative nature of these systems, such collisions are fundamentally different from those typically studied in classical physics.

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Limbless animals like snakes inhabit most terrestrial environments, generating thrust to overcome drag on the elongate body via contacts with heterogeneities. The complex body postures of some snakes and the unknown physics of most terrestrial materials frustrates understanding of strategies for effective locomotion. As a result, little is known about how limbless animals contend with unplanned obstacle contacts.

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In the evolutionary transition from an aquatic to a terrestrial environment, early tetrapods faced the challenges of terrestrial locomotion on flowable substrates, such as sand and mud of variable stiffness and incline. The morphology and range of motion of appendages can be revealed in fossils; however, biological and robophysical studies of modern taxa have shown that movement on such substrates can be sensitive to small changes in appendage use. Using a biological model (the mudskipper), a physical robot model, granular drag measurements, and theoretical tools from geometric mechanics, we demonstrate how tail use can improve robustness to variable limb use and substrate conditions.

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Spontaneous intracerebral haemorrhage (ICH) is a devastating disease with a mortality rate of more than 40 % and a high morbidity rate with 10-15 % of survivors remaining fully dependent [11]. The role of surgical treatment of ICH remains a matter of controversy and ongoing investigation. Advances in neurosurgical techniques such as endoscopy and neuronavigation have been established in various fields of neurosurgery.

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Background: Changes in the perihemorrhagic zone (PHZ) of intracerebral hemorrhage (ICH) are variable. Different mechanisms contribute to secondary neuronal injury after ICH. This multimodal monitoring study investigated early changes in the PHZ of ICH.

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Spreading depolarization (SD) is a wave of mass neuronal and glial depolarization that propagates across the cerebral cortex and has been implicated in the pathophysiology of brain injury states and migraine with aura. Analgesics and sedatives seem to have a significant effect on SD modulation. Studies have shown that ketamine, an NMDA receptor blocker, has the capacity to influence SD occurrence.

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The Bragg angle, rocking curve, and reflection efficiency of a quartz crystal x-ray imager (Miller indices 234) were measured at photon energy of 15.6909 keV, corresponding to the K(α2) line of Zr, using the X15A beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. One flat and three spherically curved samples were tested.

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Objectives: To describe early perihemorrhagic changes after lobar intracerebral hemorrhage (ICH) using multiparametric neuromonitoring [intracranial pressure (ICP), cerebral blood flow (CBF), tissue oxygenation (PbrO2), microdialysis (MD)].

Methods: Seven anaesthetized male swine were examined over 12 h. Four cerebral probes were inserted around the ICH (ICP, MD, CBF and PbrO2).

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