机器人骨骼-肌肉系统工程模拟的动态分析

用振动学理论对仿人机器人骨骼-肌肉系统工程模型进行了分析,并提出了一种控制振动的方法,提高仿人机器人运动精度和缩短达到稳定的时间,同时阐述了这种方法的可行性。     

Adaptive robust posture control of a parallel manipulator driven by pneumatic muscles

Rather severe parametric uncertainties and uncertain nonlinearities exist in the dynamic modeling of a parallel manipulator driven by pneumatic muscles. Those uncertainties not only come from the time-varying friction forces and the static force modeling errors of pneumatic muscles but also from the inherent complex nonlinearities and unknown disturbances of the parallel manipulator. In this paper, a discontinuous projection-based adaptive robust control strategy is adopted to compensate for both the parametric uncertainties and uncertain nonlinearities of a three-pneumatic-muscles-driven parallel manipulator to achieve precise posture trajectory tracking control. The resulting controller effectively handles the effects of various parameter variations and the hard-to-model nonlinearities such as the friction forces of the pneumatic muscles. Simulation and experimental results are obtained to illustrate the effectiveness of the proposed adaptive robust controller.     

猪苍白肌游离氨基酸简易测定

运用简易测定方法,了解苍白肌中游离氨基酸的消长.     

Effect of Long-Term Supplementation with Acetic Acid on the Skeletal Muscle of Aging Sprague Dawley Rats

Mitochondrial function in skeletal muscle, which plays an essential role in oxidative capacity and physical activity, declines with aging. Acetic acid activates AMP-activated protein kinase (AMPK), which plays a key role in the regulation of whole-body energy by phosphorylating key metabolic enzymes in both biosynthetic and oxidative pathways and stimulates gene expression associated with slow-twitch fibers and mitochondria in skeletal muscle cells. In this study, we investigate whether long-term supplementation with acetic acid improves age-related changes in the skeletal muscle of aging rats in association with the activation of AMPK. Male Sprague Dawley (SD) rats were administered acetic acid orally from 37 to 56 weeks of age. Long-term supplementation with acetic acid decreased the expression of atrophy-related genes, such as atrogin-1, muscle RING-finger protein-1 (MuRF1), and transforming growth factor beta (TGF-β), activated AMPK, and affected the proliferation of mitochondria and type I fiber-related molecules in muscles. The findings suggest that acetic acid exhibits an anti-aging function in the skeletal muscles of aging rats.     

Rapid determination of 19 quinolone residues in spiked fish and pig muscle by high-performance liquid chromatography (HPLC) tandem mass spectrometry

A multiresidue method has been developed for the confirmation and quantification of 19 quinolones (enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin, flumequine, oxolinic acid, difloxacin, sarafloxacin, sparfloxacin, danofloxacin, fleroxacin, marbofloxacin, enoxacin, orbifloxacin, pefloxacin, nalidixic acid, pipemidic acid, lomefloxacin and cinoacin) in pig and fish by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile, analytes separated by LC on a C₁₈ column using 0.1% formic acid–methanol with a linear gradient elution programme, and detected by MS/MS. The linear range was 0.3–50 µg kg^–1 with correlation coefficients (r) more than 0.9956. The limits of detection were 0.1 µg kg^–1. Mean recoveries for each analyte in pig muscle and fish ranged from 75.3% to 96.3% and from 79.7% to 94.2% with relative standard deviations below 10%. The method is fast, safe, sensitive and precise, and can be used simultaneously to analyse residual quinolones.     

Effect of isoelectric solubilization/precipitation and titanium dioxide on whitening and texture of proteins recovered from dark chicken-meat processing by-products

Processing of chicken generates by-products containing muscle proteins attached to bones and skin that, if recovered, could be a functional ingredient in restructured food products. However, color of restructured products made of proteins recovered from chicken processing by-products is poor. The by-products contain bones, skin, fat, etc. that affect color of restructured products. Therefore, color properties need to be improved. The objectives of this study were to determine effects of isoelectric solubilization/precipitation (ISP) and TiO₂ on instrumental color and texture properties of heat-set gels made of proteins recovered from dark chicken-meat processing by-products as compared to gels made of chicken breast meat. Skin-on bone-in chicken drumsticks were used as a model dark chicken-meat processing by-products. TiO₂ at 0-1 g/100 g and canola oil at 10 g/100 g were added to the ISP-recovered proteins followed by cooking. Due to higher (P < 0.05) yellowness (b∗) and lower (P < 0.05) lightness (L∗), the whiteness of drumstick gels without TiO₂ was lower (P < 0.05) than breast gels. TiO₂ at 1 g/100 g with canola oil resulted in slightly better (P < 0.05) whiteness of drumstick gels than breast gels. TiO₂ did not deteriorate gel texture, which was generally comparable to breast gels. This research indicates that ISP allows recovery of proteins from skin-on bone-in dark chicken-meat processing by-products without removal of bones, skin, and fat prior to processing. Addition of TiO₂ to proteins recovered from these by-products allows development of heat-set gels with color and texture comparable to chicken breast gels. Although this study shows the potential for a novel, marketable food product, sensory tests are recommended.     

Work-related chronic injuries of the forearm and hand: their specific diagnosis and management

Work-related chronic injuries occur in muscles, tendons, and nerves. Epidemiological, histological, and physiological data confirm their often disputed physical basis. Terms such as repetitive strain injury and cumulative trauma disorder, when used as a diagnosis, have obscured the issue for they are really statements of causation. Definitive diagnosis is required both to treat and prevent such injuries. Precise terminology that identifies the tissue and its pathology is required. A detailed assessment methodology is described that allows a precise diagnosis. A clear relationship to work stress is necessary both to establish the cause and formulate prevention strategies. Treatment must begin early and be appropriate to the tissue and the nature of the injury. Examples are presented and discussed. Early treatment begins before too much damage has been done and yields better results.