Recent research progress of relieving discomfort between electronics and human body involves serpentine designs, ultrathin films, and extraordinary properties of nanomaterials. However, these ...strategies addressed thus far each face own limitation for achieving desired form of electronic-skin applications. Evenly matched mechanical properties anywhere on the body and imperceptibility of electronics are two essentially required characteristics for future electronic-skin (E-skin) devices. Yet accomplishing these two main properties simultaneously is still very challenging. Hence, we propose a novel fabrication method to introduce kirigami approach to pattern a highly conductive and transparent electrode into diverse shapes of stretchable electronics with multivariable configurability for E-skin applications. These kirigami engineered patterns impart tunable elasticity to the electrodes, which can be designed to intentionally limit strain or grant ultrastretchability depending on applications over the range of 0 to over 400% tensile strain with strain-invariant electrical property and show excellent strain reversibility even after 10 000 cycles stretching while exhibiting high optical transparency (>80%). The versatility of this work is demonstrated by ultrastretchable transparent kirigami heater for personal thermal management and conformal transparent kirigami electrophysiology sensor for continuous health monitoring of human body conditions. Finally, by integrating E-skin sensors with quadrotor drones, we have successfully demonstrated human-machine-interface using our stretchable transparent kirigami electrodes.
This paper discusses the path-following control of a ship or other floating object by pushing using a single autonomous tugboat. To do this, we first formulate a reduced dynamic equation that ...contains the dynamics of both the ship and the tugboat without contact force terms, and is expressed by independent variables, such as ship variables (surge, sway, and yaw rates), allowing us to deal with the ship and tugboat as a single system to control the independent variables. It is assumed in this study that the contact between the ship and tugboat is a point contact, and the contact point does not slip. To manipulate the motion of a ship by pushing, the pushing force must be exerted without slipping at the contact point. Thus, the contact force is derived from the dynamic equations of the ship and tugboat and the velocity constraints on the contact point, and its feasible region is defined. This contact force condition is then incorporated into a path-following control method using the reduced dynamic equation to handle the contact force during the pushing operation. The contact force is checked to determine whether it is likely to be exerted outside the feasible region; if so, the control gain used in the path-following control is switched to a smaller value. Simulations under different paths and contact positions are performed, and the results demonstrate that the proposed pushing control method allows the ship to follow a given path correctly while maintaining the contact condition.
Pathological aggregation of the transactive response DNA-binding protein of 43 kDa (TDP-43) is associated with several neurodegenerative disorders, including ALS, frontotemporal dementia, chronic ...traumatic encephalopathy, and Alzheimer's disease. TDP-43 aggregation appears to be largely driven by its low-complexity domain (LCD), which also has a high propensity to undergo liquid–liquid phase separation (LLPS). However, the mechanism of TDP-43 LCD pathological aggregation and, most importantly, the relationship between the aggregation process and LLPS remains largely unknown. Here, we show that amyloid formation by the LCD is controlled by electrostatic repulsion. We also demonstrate that the liquid droplet environment strongly accelerates LCD fibrillation and that its aggregation under LLPS conditions involves several distinct events, culminating in rapid assembly of fibrillar aggregates that emanate from within mature liquid droplets. These combined results strongly suggest that LLPS may play a major role in pathological TDP-43 aggregation, contributing to pathogenesis in neurodegenerative diseases.
A multichannel field-programmable gate array (FPGA)-based time-to-digital converter (TDC) and its calibration techniques are presented. Herein, a frequency-tracker-based sliding-scale technique and a ...moving-average filter to improve the linearity and resolution are proposed. The error calibration technique automatically detects and corrects conversion errors caused by variations and mismatches in the propagation delays. The gain calibration extracts the average bin width of the fine TDC and resolves any linearity degradation in the coarse/fine interpolation architecture. The proposed techniques were applied to a four-channel TDC design implemented on a Xilinx Artix-7 FPGA. The measured differential and integral nonlinearities of all channels were within 0.51 least significant bit of 4.88 ps. The root-mean-squared resolution of the output code was 2.90-8.03 ps across a wide input range of 350 μs.
This article presents Exo-Glove Poly (EGP) II, a soft wearable robot for the hand with a glove that is completely constructed of polymer materials and that operates through tendon-driven actuation ...for use in spinal cord injury (SCI). EGP II can restore the ability to pinch and grasp any object for people with SCI in daily life. The design of the glove allows it to be compact and extends the range of hand sizes that can fit. A passive thumb structure was developed to oppose the thumb for improved grasping. To increase the robustness of the glove, EGP II was designed to have a minimal number of components using a single material. A kinematic model of the system was used to optimize the design parameters of an antagonistic tendon routing system on a single actuator for various hand sizes and repeated actuations. Experiments were conducted on two subjects with SCI to verify the grasping performance of EGP II. EGP II has a compact glove and an actuation system that can be placed on a desk or wheelchair, with the weights of 104 g and 1.14 kg, respectively.
Recombinant C-terminally truncated prion protein PrP23-144 (which corresponds to the Y145Stop PrP variant associated with a Gerstmann–Sträussler–Scheinker-like prion disease) spontaneously forms ...amyloid fibrils with a parallel in-register β-sheet architecture and β-sheet core mapping to residues ∼112–139. Here we report that mice (both tga20 and wild type) inoculated with a murine (moPrP23-144) version of these fibrils develop clinical prion disease with a 100% attack rate. Remarkably, even though fibrils in the inoculum lack the entire C-terminal domain of PrP, brains of clinically sick mice accumulate longer proteinase K-resistant (PrPres) fragments of ∼17–32 kDa, similar to those observed in classical scrapie strains. Shorter, Gerstmann–Sträussler–Scheinker-like PrPres fragments are also present. The evidence that moPrP23-144 amyloid fibrils generated in the absence of any cofactors are bona fide prions provides a strong support for the protein-only hypothesis of prion diseases in its pure form, arguing against the notion that nonproteinaceous cofactors are obligatory structural components of all infectious prions. Furthermore, our finding that a relatively short β-sheet core of PrP23-144 fibrils (residues ∼112–139) with a parallel in-register organization of β-strands is capable of seeding the conversion of full-length prion protein to the infectious form has important implications for the ongoing debate regarding structural aspects of prion protein conversion and molecular architecture of mammalian prions.
This article presents a new, modularized design concept based on a bottom-up approach to assembly. This concept enables the structures and motions of soft robots to be rapidly revised to create new ...designs that can accomplish different tasks. We designed three basic types of pneumatically actuated soft modules, called soft robotic blocks (SoBL), that implement a single motion each (translation, bending, or twisting), which, when assembled, create structures capable of various motions. We introduce three types of connection mechanisms-screw thread, push fitting, and bistable junction-that can be used with any of the modules and that are designed to make for easy assembly and disassembly. Units were fabricated by multimaterial threedimensional (3-D) printing or silicone molding.
Cell-to-cell junctions are critical for the formation of endothelial barriers, and its disorganization is required for sprouting angiogenesis. Members of the angiomotin (AMOT) family have emerged as ...key regulators in the control of endothelial cell (EC) junction stability and permeability. However, the underlying mechanism by which the AMOT family is regulated in ECs remains unclear. Here we report that HECW2, a novel EC ubiquitin E3 ligase, plays a critical role in stabilizing endothelial cell-to-cell junctions by regulating AMOT-like 1 (AMOTL1) stability. HECW2 physically interacts with AMOTL1 and enhances its stability via lysine 63-linked ubiquitination. HECW2 depletion in human ECs decreases AMOTL1 stability, loosening the cell-to-cell junctions and altering subcellular localization of yes-associated protein (YAP) from cytoplasm into the nucleus. Knockdown of HECW2 also results in increased angiogenic sprouting, and this effect is blocked by depletion of ANG-2, a potential target of YAP. These results demonstrate that HECW2 is a novel regulator of angiogenesis and provide new insights into the mechanisms coordinating junction stability and angiogenic activation in ECs.
Coupling factors are calculated in order to facilitate non-uniform magnetic field exposure assessment. Coupling factors take into account the characteristics of a localized non-uniform field source, ...whereas reference levels in electromagnetic field safety guidelines only consider uniform field exposures. The calculations are performed using several different equivalent human models including simplified homogeneous models and a complex anatomical model. Three types of non-uniform sources are considered; a circular coil in a vertical plane, a circular coil in a horizontal plane, and a straight wire in a horizontal plane. For modeling and quasi-static electromagnetic simulation of the complex anatomical human model, Sim4Life software was used, which applies finite-element method to graded voxel meshes. The dependence of coupling factor values on the various parameters including source type, distance between source and human model, coil radius, and type of the equivalent human model used is analyzed. Also, separate definitions of coupling factors given in various IEC standards are analyzed and their differences in practical applications are investigated.
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