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artificial muscle

Shigehisa Aoki, Yasuhisa Sakata, Ryo Shimoda, Toshiaki Takezawa, Ayumi Oshikata-Miyazaki, Hiromi Kimura, Mihoko Yamamoto, Ryuichi Iwakiri, Kazuma Fujimoto, Shuji Toda
BACKGROUND AND AIMS: Extensive excision of the esophageal mucosa by endoscopic submucosal dissection (ESD) frequently evokes a luminal stricture. This study aimed to determine the efficacy of a high-density collagen patch for the prevention of esophageal stricture in extensive ESD. METHODS: Six pigs underwent circumferential esophageal ESD under general anesthesia. In 3 pigs, artificial ulcers were covered by 2 collagen patches. The other 3 pigs underwent circumferential ESD only...
October 14, 2016: Gastrointestinal Endoscopy
Morteza Amjadi, Metin Sitti
There is an increasing demand for soft actuators because of their importance in soft robotics, artificial muscles, biomimetic devices, and beyond. However, the development of soft actuators capable of low-voltage operation, powerful actuation, and programmable shape-changing is still challenging. In this work, we propose programmable bilayer actuators that operate based on the large hygroscopic contraction of the copy paper and simultaneously large thermal expansion of the polypropylene film upon increasing the temperature...
October 16, 2016: ACS Nano
Karinne Saucedo-Vence, Armando Elizalde-Velázquez, Octavio Dublán-García, Marcela Galar-Martínez, Hariz Islas-Flores, Nely SanJuan-Reyes, Sandra García-Medina, María Dolores Hernández-Navarro, Leobardo Manuel Gómez-Oliván
Sucralose (SUC) is an artificial sweetener that is now widely used in North American and Europe; it has been detected in a wide variety of aquatic environments. It is considered safe for human consumption but its effects in the ecosystem have not yet been studied in depth, since limited ecotoxicological data are available in the peer-reviewed literature. This study aimed to evaluate potential SUC-induced toxicological hazard in the blood, brain, gill, liver and muscle of Cyprinus carpio using oxidative stress biomarkers...
October 13, 2016: Science of the Total Environment
Qingyu Peng, Hongqiu Wei, Yuyang Qin, Zaishan Lin, Xu Zhao, Fan Xu, Jinsong Leng, Xiaodong He, Anyuan Cao, Yibin Li
Electrical stimulation of shape-memory polymers (SMPs) has many advantages over thermal methods; creating an efficient conductive path through the bulk polymers is essential for developing high performance electroactive systems. Here, we show that a three-dimensional (3D) porous carbon nanotube sponge can serve as a built-in integral conductive network to provide internal, homogeneous, in situ Joule heating for shape-memory polymers, thus significantly improving the mechanical and thermal behavior of SMPs. As a result, the 3D nanocomposites show a fast response and produce large exerting forces (with a maximum flexural stress of 14...
October 14, 2016: Nanoscale
Shahab Shahdoost, Randolph Nudo, Pedram Mohseni
Brain-machine-body interfaces (BMBIs) aim to create an artificial connection in the nervous system by converting neural activity recorded from one cortical region to electrical stimuli delivered to another cortical region, spinal cord, or muscles in real-time. In particular, conditioning-mode BMBIs utilize such activity-dependent stimulation strategies to induce functional re-organization in the nervous system and promote functional recovery after injury by exploiting mechanisms underlying neuroplasticity. This paper reports on reconfigurable, field-programmable gate array (FPGA)-based implementation of a translation algorithm to extract multichannel stimulus trigger signals from intracortical neural spike activity...
October 5, 2016: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Xiaogang Gu, Qingxia Fan, Feng Yang, Le Cai, Nan Zhang, Wenbin Zhou, Weiya Zhou, Sishen Xie
Hybrid hydro-responsive actuators are developed by infiltrating carbon nanotube yarns using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). These actuators demonstrate impressive rotation and contraction in response to water due to volumetric expansion of the helical arrangement of carbon nanotubes. The total torsional stroke is 3720 revolutions per m and the simultaneously generated contractive strain reaches 24% at a paddle-to-yarn mass ratio of 350. The contraction output can furthermore be significantly enhanced by constraining the rotational motion and it reaches 68% with an applied stress of 1 MPa...
October 7, 2016: Nanoscale
Zhi Liu, Qiang Li, Gaoyu Cui, Gang Zhu, Weihua Tang, Hengli Zhao, John H Zhang, Yujie Chen, Hua Feng
Previously, it was widely accepted that the delayed ischemic injury and poor clinical outcome following subarachnoid hemorrhage (SAH) was caused by cerebral vasospasm. This classical theory was challenged by a clazosentan clinical trial, which failed to improve patient outcome, despite reversing angiographic vasospasm. One possible explanation for the results of this trial is the changes in microcirculation following SAH, particularly in pericytes, which are the primary cell type controlling microcirculation in the brain parenchyma...
October 2016: Experimental and Therapeutic Medicine
Camila Cristina Ishikawa, Thais Gonçalves Pinheiro, Adriana Hachiya, Arlindo Neto Montagnoli, Domingos Hiroshi Tsuji
OBJECTIVES: The aim of this study was to evaluate the effects of cricothyroid muscle contraction on vocal fold vibration, as evaluated with high-speed videoendoscopy, and to identify one or more aspects of vocal fold vibration that could be used as an irrefutable indicator of unilateral cricothyroid muscle paralysis. STUDY DESIGN: This was an experimental study employing excised human larynges. METHODS: Twenty freshly excised human larynges were evaluated during artificially produced vibration...
September 28, 2016: Journal of Voice: Official Journal of the Voice Foundation
Hao Wu, Zhiwu Wang, Guozheng Yan, Wentian Jin, Shan Lu, Zerun Zhou
This article presents a novel puborectalis muscle artificial anal sphincter system (PM-AASS) with the module of sensory perception for treating severe faecal incontinence (FI). Due to the implantable feature of PM-AASS, this system applied low-power design and the total energy consumption could drop to 48.8 Ah/d. To reduce the injury of intestine and the pressure exerted on intestine, the actuator, including the structure of tings and the robot mechanism, of PM-AASS was presented and the middle ring was optimised...
September 30, 2016: Journal of Medical Engineering & Technology
Bernard Grandjean, Marc A Maier
Muscle spindle discharge during active movement is a function of mechanical and neural parameters. Muscle length changes (and their derivatives) represent its primary mechanical, fusimotor drive its neural component. However, neither the action nor the function of fusimotor and in particular of γ-drive, have been clearly established, since γ-motor activity during voluntary, non-locomotor movements remains largely unknown. Here, using a computational approach, we explored whether γ-drive emerges in an artificial neural network model of the corticospinal system linked to a biomechanical antagonist wrist simulator...
September 27, 2016: Journal of Computational Neuroscience
Chuan Tian, Shiwei Pan
We report the case of a 26-year old woman who underwent successful tricuspid valve repair for the absence of the anterior papillary of the tricuspid valve. Preoperative echocardiography revealed grade IV tricuspid valve regurgitation, caused by congenital absence of the anterior papillary muscle and prolapse of the anterior leaflet. Tricuspid valve repair was performed using artificial chords consisting of two polytetrafluoroethylene sutures and a concomitant ring annuloplasty. Postoperative echocardiography revealed mild tricuspid valve regurgitation...
September 27, 2016: Interactive Cardiovascular and Thoracic Surgery
Shuang Jiao, Zhihao Wu, Xungang Tan, Yulei Sui, Lijuan Wang, Feng You
Although chromosome set manipulation techniques including polyploidy induction and gynogentic induction in flatfish are becoming increasingly mature, there exists a poor understanding of their effects on embryonic development. PAX3 plays crucial roles during embryonic myogenesis and neurogenesis. In olive flounder (Paralichthys olivaceus), there are two duplicated pax3 genes (pax3a, pax3b), and both of them are expressed in the brain and muscle regions with some subtle regional differences. We utilized pax3a and pax3b as indicators to preliminarily investigate whether chromosome set manipulation affects embryonic neurogenesis and myogenesis using whole-mount in situ hybridization...
September 27, 2016: Fish Physiology and Biochemistry
Carter S Haines, Na Li, Geoffrey M Spinks, Ali E Aliev, Jiangtao Di, Ray H Baughman
Lightweight artificial muscle fibers that can match the large tensile stroke of natural muscles have been elusive. In particular, low stroke, limited cycle life, and inefficient energy conversion have combined with high cost and hysteretic performance to restrict practical use. In recent years, a new class of artificial muscles, based on highly twisted fibers, has emerged that can deliver more than 2,000 J/kg of specific work during muscle contraction, compared with just 40 J/kg for natural muscle. Thermally actuated muscles made from ordinary polymer fibers can deliver long-life, hysteresis-free tensile strokes of more than 30% and torsional actuation capable of spinning a paddle at speeds of more than 100,000 rpm...
September 26, 2016: Proceedings of the National Academy of Sciences of the United States of America
S S Mostafa, M A Awal, M Ahmad, M A Rashid
Some people cannot produce sound although their facial muscles work properly due to having problem in their vocal cords. Therefore, recognition of alphabets as well as sentences uttered by these voiceless people is a complex task. This paper proposes a novel method to solve this problem using non-invasive surface Electromyogram (sEMG). Firstly, eleven Bangla vowels are pronounced and sEMG signals are recorded at the same time. Different features are extracted and mRMR feature selection algorithm is then applied to select prominent feature subset from the large feature vector...
2016: SpringerPlus
M W Laschke, M D Menger
The dorsal skinfold chamber is a rodent model for non-invasive microcirculatory analyses of striated muscle and skin tissue throughout an observation period of 2-3 weeks. In combination with intravital fluorescence microscopy, this model allows the quantitative assessment of dynamic processes such as inflammation, angiogenesis, vascular remodelling and microcirculation. Accordingly, the dorsal skinfold chamber is increasingly used for preclinical research in tissue engineering and regenerative medicine. This includes studies on biocompatibility, vascularisation and incorporation of medical implants and artificial tissue constructs...
2016: European Cells & Materials
Jiuke Mu, Chengyi Hou, Gang Wang, Xuemin Wang, Qinghong Zhang, Yaogang Li, Hongzhi Wang, Meifang Zhu
Using a 3D stretching method, a highly elastic reduced graphene oxide (rGO)/polyacrylic ester hierarchically wrinkled elastic transparent conductor (HWETC) is fabricated. Periodic hierarchical N-rGO layer wrinkling allows the HWETC to show high conductivity (100-457 Ω ◻(-1) ) and transmittance (67-85%) under substantial stretching (>400%) and bending deformation (≈180°), which enables electrothermal actuation and strain sensing.
September 15, 2016: Advanced Materials
Vincenzo Rago, António N Rebelo, Federico Pizzuto, Daniel Barreira
BACKGROUND: The use of sand has been suggested as fitness-enhancing surface in field-based team sports. However, concerns have arisen in regard whether physical responses associated to sand training are sport-specific. We compared physical and technical demands during small-sided football games (4v4 + goalkeeper; SSGs) played on artificial turf and on sand. METHODS: Movement patterns, rating of perceived exertion (RPE) and technical parameters were obtained from eight adult male footballers (20...
September 15, 2016: Journal of Sports Medicine and Physical Fitness
Y F Du, Q L Ding, Y M Li, W R Fang
In the modern chicken industry, fast-growing broilers have undergone strong artificial selection for muscle growth, which has led to remarkable phenotypic variations compared with slow-growing chickens. However, the molecular mechanism underlying these phenotypes differences remains unknown. In this study, a systematic identification of candidate genes and new pathways related to myofiber development and composition in chicken Soleus muscle (SOL) has been made using gene expression profiles of two distinct breeds: Qingyuan partridge (QY), a slow-growing Chinese breed possessing high meat quality and Cobb 500 (CB), a commercial fast-growing broiler line...
September 13, 2016: Animal Biotechnology
Sylvie A DeLaHunt, Thomas E Pillsbury, Norman M Wereley
The natural compliance and force generation properties of pneumatic artificial muscles (PAMs) allow them to operate like human muscles in anthropomorphic robotic manipulators. Traditionally, manipulators use a single PAM or multiple PAMs actuated in unison in place of a human muscle. However, these standard manipulators can experience significant efficiency losses when operated outside their target performance ranges at low actuation pressures. This study considers the application of a variable recruitment control strategy to a parallel bundle of miniature PAMs as an attempt to mimic the selective recruitment of motor units in a human muscle...
2016: Bioinspiration & Biomimetics
Tomohiro Nakamura, Shunya Takagi, Takafumi Kamon, Ken-Ichi Yamasaki, Toshia Fujisato
Tissue-engineered skeletal muscles were potentially useful as physiological and biochemical in vitro models. Currently, most of the similar models were constructed without tendons. In this study, we aimed to develop a simple, highly versatile tissue-engineered muscle with artificial tendons, and to evaluate the contractile, histological and molecular dynamics during differentiation. C2C12 cells were embedded in a cold type-І collagen gel and placed between two artificial tendons on a silicone sheet. The construct shrank and tightly attached to the artificial tendons with differentiation, finally detaching from the silicone sheet within 1 week of culture onset...
September 9, 2016: Journal of Bioscience and Bioengineering
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