• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.8
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• pp.1046-1053
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• 1999

The musculotendon model is presented to show the declines in muscle force and shortening velocity during muscle fatigue due to the repeated functional electrical stimulation (FES). It consists of the nonlinear activation and contraction dynamics including physiological concepts of muscle fatigue. The activation dynamics represents $Ca^{2+}$ binding and unbinding mechanism with troponins of cross-bridges in sarcoplasm. It has the constant binding rate or activation time constant and two step nonlinear unbinding rate or inactivation time constant. The contraction dynamics is the modified Hill type model to represent muscle force - length and muscle force - velocity relations. A muscle fatigue profile as a function of the intracellular acidification, pH is applied into the contraction dynamics to represent the force decline. The computer simulation shows that muscle force and shortening velocity decline in stimulation time. And we validate the model. The model can predicts the proper muscle force without changing its parameters even when existing the estimation errors of the optimal fiber length. The change in the estimate of the optimal fiber length has an effect only on muscle time constant in transient period not on the tetanic force in the steady-state and relaxation periods.

• Korean Journal of Veterinary Service
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• v.31 no.1
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• pp.161-166
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• 2008

Deep pectoral myopathy (DPM), also known as Oregon muscle disease or green muscle disease, was first described in 1968 by Dickinson et al as "degenerative myopathy" in turkeys. Even though this condition was first recognized in adult meat-type turkey and chicken breeders, it is becoming more and more common in meat-type growing birds. DPM occurs exclusively in birds that have been specially selected for breast muscle development. It is generally recognized that DPM is an ischemic necrosis that develops in the deep pectoral muscle (supracoracoideus or pectoralis minor muscle) mainly because this muscle is surrounded by inelastic fascia and the sternum, which do not allow the muscle mass to swell in response to the physiological changes occurring when muscle are exercised, as in wing flapping. The lesion does not impair the general health of birds and is generally found during cut-up and deboning, moreover, it can be both unilateral or bilateral, affecting just one or both pectoralis minor muscle, respectively. No public health significance is associated to DPM, but it is aesthetically undesirable. The fillet should be removed, whereas the rest of the carcass is still fit for human consumption. However, the required trimming operations determine the downgrading of the products and produce an economic loss for the industry, especially because it affects the more valuable part of the carcass. The incidence of DPM increases with market weight in broilers, with more cases reported in higher-yielding strains and in males. Increased bird activity (flock nervousness, flightiness, struggle, and wing flapping) induced by factors such as feed or water outages, lighting programs and intensity, human activity, and excessive noises in and around chicken houses should be looked at as a trigger for the development of DPM in broiler. However, most of the studies conducted to evaluate the incidence of DPM in poultry are concerned with parental commercial breeding stocks under experimental conditions (Bianchi et al. 2006. Poult Sci 85 : 1843-1846). There is a possible genetic relationship between the selection for large-breasted birds and this condition. Management procedures that discourage excessive wing flapping would reduce the incidence (Jordan and Pattison. 1998. Poultry diseases. 398-399).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.256-259
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• 2013

Botulinum toxin type A (BTX-A) inhibits muscle contraction, which leads to reversible muscle atrophy and paralysis. Therefore, BTX-A injection can be an effective treatment of facial asymmetry that originated from the uncoordinated muscle movement. A 52-year-old patient was referred from another hospital for the correction of post-traumatic sequelae. The patient had prominent scar in the mandibular symphysis area with asymmetric lower lip movement. The reason for this asymmetric lower lip movement was due to damage in the lower lip depressor muscle. After the injection of BTX-A on the lower lip depressors, asymmetric lip movement has been improved.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.965-970
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• 2008

The objective of this study was to examine the relationship between instrumental tenderness parameters and histochemical characteristics in the porcine longissimus dorsi muscle, and to investigate a comparison between tenderness parameters such as the Warner-Bratzler shear-force (WBS) and texture profile analysis (TPA). A negative relationship between WBS and fiber area was observed. However, there was no significant relationship between hardness and muscle fiber area. The percentage of fiber type IIb exhibited a positive correlation with hardness. There was a negative relationship between the type IIa composition percentage and hardness. This study showed that some muscle fiber characteristics were related to WBS and TPA parameters, especially hardness.

• Journal of Veterinary Clinics
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• v.21 no.3
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• pp.291-297
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• 2004

Aminoglycosidic antibiotics have multiple effects on muscle. For example, they have been shown to block L-type $Ca^{2+}$ channels in vascular smooth muscle, cardiac muscle and skeletal muscle. Possibly as a consequence of this effect on $Ca^{2+}$ influx, they have been shown to decrease the contractility of cardiac muscle (gentamicin). The present study evaluated the effects of gentamicin on blood pressure, vasorelaxation and left ventricular pressure. Gentamicin(10, 20, 40mg/kg) produced dose-dependent blood pressure lowering in rat. The pretreatment of MgSO$_4$ and imipramine (Na$^{+}$-Mg$^{2+}$ exchange inhibitor) had no effect in gentamicin-induced hypotension. However, the gentamicin-induced hypotension was significantly potentiated in the preincubation of verapamil or nifedipine (L-type $Ca^{2+}$ channel blockers), and was significantly attenuated by CaCl$_2$ and was slightly attenuated by caffeine (phosphodiesterase inhibitor). Gentamicin (10, 30, 100$\mu$g/m1) did not have an effect on relaxation of phenylephrine-precontracted aortic rings but high concentration of gentamicin(100, 300$\mu$g/ml) relaxed KCl-precontracted aortic rings, which relaxation was potentiated by treatment of nifedipine. Whereas gentamicin markedly decreased left ventricular developed pressure (LVDP) in perfused heart. These data suggest that gentamicin has significant blood pressure lowering of the rat, which seems to be mediated by calcium channel-sensitive pathway and blood $Ca^{2+}$ level may be important role in this response.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.1-9
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• 2020

PURPOSE: This study examined the effects of muscle fatigue on proprioception in the type of taekwondo training, causing injury to taekwondo athletes. METHODS: The subjects were divided into Taekwondo Kyorugi athletes (n = 14) and Taekwondo Poomsae athletes (n = 14). After inducing muscle fatigue to the subjects, the joint position sense (JPS) and the force reproduction sense (FRS) were measured before and immediately after the induction of muscle fatigue. RESULTS: Studies have shown no significant impact on the JPS and FRS caused by muscle fatigue induced by Poomsae and Kyorugi (p > .05). The JPS, however, showed a significant difference before and after Kyorugi (p < .05). The FRS showed significant differences before and after Poomsae (p < .05). Through this study, the injuries to taekwondo athletes appear to be influenced by the joint position and force reproduction. Moreover, the injury appears to affect the joint position sense in Kyorugi athletes and the force reproduction sense in Poomsae athletes. CONCLUSION: The results will contribute to injury prevention and athlete protection. In addition, the information can be used as basic data for the development of sports injuries prevention and rehabilitation programs for Taekwondo athletes. Research is needed on the customized management of sports methods and self-care to prevent sports damage, considering the athletic characteristics of the taekwondo athletes in the future.

• Physical Therapy Rehabilitation Science
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• v.11 no.3
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• pp.321-328
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• 2022

Objective: The purpose of this study was to investigate the effect of neck stabilization exercise combined with vibroacoustic sound on patients with chronic neck pain and tension-type headache. Design: Two group pre test - post test design. Methods: 36 patients participated. Headache impact test-6(HIT-6), numerical rating scale(NRS) and muscle characteristics were measured at pre-post test. Participants divided into vibroacoustic sound group(VSG, n=18), control group(CG, n=18). VSG performed neck stabilization exercise and vibroacoustic sound stimulation. CG performed neck stabilization exercise. Both groups participated 3 times a week for a total of 4 weeks. Results: NRS showed a significant difference before and after intervention in both groups (p<0.05). HIT-6 showed a significant difference before and after intervention in the VSG group (p<0.05). Muscle tone showed a significant difference before and after intervention in the experimental group (p<0.05). There was no significant difference in muscle stiffness and muscle elasticity before and after the intervention in both groups (p>0.05). Conclusions: Based on the results of the study, it is thought that sonic vibroacoustic sound can be established as an effective treatment tool through a study applied to various diseases and symptoms.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.1
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• pp.57-67
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• 2006

Musculoskeletal neck dysfunction syndromes are common in outpatient musculoskeletal pain practice. The underlying musculoskeletal and neurologic causes of pain are variable. In the management of these patients, it is important to accurately identify and treat these pain generators to optimize patient outcome. It is the purpose of this review to discuss three main categories of functional anatomy, the role of superficial/deep muscular system and the scientific evidence for optimal physical therapy intervention for cervical dysfunction. Specifically there is evidence of lowered microcirculation in the upper trapezius muscle, morphological signs of disturbed mitochondrial function which appears to be limited to type I fibers and an increased cross-sectional area of type I muscle fibers despite a lower capillary to fiber area ratio. In acute neck pain syndrome, changes in muscle activity of painful muscles may result from segmental and supraspinal inhibitory effects. Muscle activation is closely related to the control of joint movements and postures and it is difficult to separate the influence of the two components. Both the altered muscle recruitment patterns and altered kinematics appear to be a poor adaptation for pain of the head - neck region, as they are likely to result in increased compressive loading in the cervical spine, affecting muscles, articular structures such as zygapophyseal joints, connective tissues and neural tissues which are all peripheral generators of referred pain. The rectus capitus posterior minor muscle shows that it is one of the most important muscles of the suboccipital region. In this article, i reviewed the anatomy, neurophysiology, function and dysfunction as well as the treatment of cervical dysfunction.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.187-193
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• 2006

Background : Normal cell proliferation and viability is strongly depends on the availability of metabolic energy and the maintenance of the appropriate adenylate-nucleotide pools. Hypothetically, changes in adenylate kinase (AK) expression could therefore be associated with adaptation to altered growth characteristics or inversely altered growth characteristics of proliferating cells could drive the changes in the metabolic profile. This study investigated whether the expression of either AK1 or a Mycobacterium tuberculosis adenylate kinase mutant which has the same catalytic activity of AK1 could affect the growth rate of slow-growing BCG. Method : Recombinant BCGs, which were cloned the human muscle-type adenylate kinase synthetic gene (AK1) and adenylate kinase mutation gene (AKmtDM) of Mycobacterium tuberculosis into the Mycobacterium/E.coli expression vectors, were constructed. Recombinant BCGs and wild-type BCG were cultured in 7H9 media and the optical density at 600nm was measured at intervals of 2-3 days. Result : There wasn't the growth rate change induced by AK1 or AKmtDM expression in recombinant BCGs. Conclusion : The expression of AK1 or Mycobacterium tuberculosis adenylate kinase mutant in BCG does not affect the growth rate of BCG.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1653-1658
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• 2000

Insulin-like growth factor-I (IGF-I) mRNA levels in the eyes, heart, liver and breast muscle removed from dwarf egg-type, normal egg-type and normal meat-type chicken embryos at 7, 14 and 20 days of incubation were measured. There was no influence of chicken strain on IGF-I gene expression in the eyes and liver. The IGF-I gene expression in eyes increased significantly along with the incubation period. In the liver, IGF-I gene expression at 20 days of incubation was significantly higher than that at 14 days of incubation. In the muscle, the lowest value for IGF-I gene expression was observed in meat-type chicken embryos. Regression analysis revealed that IGF-I gene expression was significantly correlated to the weights of the eyes and liver, but not the muscle. We conclude that there is little influence of strain on tissue IGF-I gene expression in chicken embryos during incubation but that tissue development in chicken embryos is nevertheless at least partly regulated by the change in IGF-I gene expression.