• Journal of Korea Entertainment Industry Association
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• v.14 no.8
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• pp.287-294
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• 2020

The purpose of this study was, base on the observation that the leg movement has effect on muscles around trunk, to provide clinical fundamental data to develop effective abdominal draw-in technique by investigating the effect of abdominal draw-in exercise accompanying leg movement on the thickness of transversus abdominis muscle and trunk control ability in patients with stroke. The subjects were assigned randomly to experimental group I (n=9) on which the abdominal draw-in technique is applied and experimental group II (n=9) on which the abdominal draw-in technique accompanying leg movement is applied. The thickness of transversus abdominis muscle in the affected side and the trunk control ability were measured before and after treatment using ultrasonography and trunk impairment scale. A session of 30 minutes per day were performed four days a week for four weeks and the measured outcomes were analyzed. The in-group comparison showed significant difference both thickness of transversus abdominis muscle during abdominal draw-in technique application (p<0.01) and trunk control ability (p<0.001) between before and after treatment. The significant difference between two groups were observed only in trunk control ability (p<0.05). It was concluded that the abdominal draw-in technique accompanying leg movement is an intervention that has positive effect not only on transversus abdominis muscle but also on tunk control ability by inducing more efficient contraction reaction in muscles around trunk through autonomic pelvic movement caused by leg movement.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.69-80
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• 1998

This research was designed to investigate how the exercise program affects paraplegic standing and walking employing functional electrical stimulation(FES). Emphasis was also given to fatigue of major lower extremity muscles induced by different types of electrical stimulation. We applied continuous and intermittent rectangular pulse trains to quadriceps of 10 normal subjects and 4 complete paraplegic patients. The frequencies were 20Hz and 80Hz, and the knee angle was fixed at 90$^{\circ}$and 150$^{\circ}$to investigate how muscle fatigue is related to muscle length. The knee extensor torque was measured and monitored. We have been training quadriceps and gastrocnemius of a male paraplegic patient by means of electrical stimulation for the past two year. FES standing was initiated when the knee extensors became strong enough to support the body weight, and then the patient started FES walking utilizing parallel bars and a walker. We used an 8-channel constant-voltage stimulator and surface electrodes. The experimental results indicated that paralyzed muscles fatigued rapidly around the optimal length contrary to normal muscles and confirmed that low frequency and intermittent stimulation delayed fatigue. Our exercise program increased muscle force by approximately 10 folds and decreased the fatigue index to half of the initial value. In addition, the exercise enabled the patient to voluntarily lift each leg up to 10cm, which was of great help to the swing phase of FES walking. Both muscle force and resistance to fatigue were significantly enhanced right after the exercise was applied every day instead of 6 days a week. Up to date, the patient can walk for more than two and half minutes at 10m/min while controlling the on/off time of the stimulator by pushing the toggle switch attached to the walker handle.

• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.427-433
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• 2018

Because of the expectation of the non-invasive treatment effect, Various studies on the treatment of varicose veins using focused ultrasound are reported. In this study, the bio-tissue phantom and tissue equivalent phantom that can be applied to estimation of ultrasonic varicose veins treatment effect. Each phantom was evaluated for its usefulness by evaluating the acoustic characteristics and the shrinkage rate according to the ultrasonic irradiation. A multi-layer structure phantom with three layers of skin, fat, and muscle was constructed considering the structure of the tissue where the varicose veins occurred. The materials constituting each layer were made to have characteristics similar to human body. In addition, the multi-layered phantoms with blood vessel mimic tube, with bovine blood vessel, and with animal tissue were fabricated. The degree of shrinkage of blood vessel mimic material and vascular tissue according to ultrasonic irradiation was evaluated using B-mode image. As the results of this study, it was thought that the proposed phantom could be used effectively in the evaluation of ultrasonic varicose veins treatment. In addition, it is thought that these phantoms could be applied to the development of varicose vein treatment device using the focused ultrasound and the verification of the therapeutic effect.

• Journal of Life Science
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• v.32 no.2
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• pp.175-188
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• 2022

Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IK_Ca channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI₂. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

• Journal of Adhesion and Interface
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• v.25 no.1
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• pp.169-274
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• 2024

Recent attention has been drawn to materials that undergo reversible expansion and contraction in response to external stimuli, leading to morphological changes. These materials hold potential applications in various fields including soft robotics, sensors, and artificial muscles. In this study, a novel material capable of responding to high temperatures for protection or encapsulation is proposed. To achieve this, liquid crystal elastomer (LCE) with nematic-isotropic transition properties and polyimide (PI) with high mechanical strength and thermal stability were utilized. To utilize a solution process, a dope solution was synthesized and introduced into micro-printing techniques to develop a two-dimensional pattern of LCE/PI bilayer structures with sub-millimeter widths. The honeycomb-patterned LCE/PI bilayer mesh combined the mechanical strength of PI with the high-temperature contraction behavior of LCE, and selective printing of LCE facilitated deformation in desired directions at high temperatures. Consequently, the functionality of selectively and reversibly encapsulating specific high-temperature materials was achieved. This study suggests potential applications in various actuator fields where functionalities can be implemented across different temperature ranges without the need for electrical energy input, contingent upon molecular changes in LCE.

• Journal of IKEEE
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• v.22 no.1
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• pp.21-28
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• 2018

In this paper, we have developed the intellectual kegel trainer with the bio-feedback. The one is smart health care system that can treat an evacuation impediment and urination polyuria with the low frequency stimulation module. Then this detects the shrinkage power of the pelvis muscles and correlates an smart phone entertainment application program for the users. In order to recover the function of pelvic muscles, we use the intellectual smart health care trainer with several biofeedback function. Such a trainer makes to strength the weakness pelvic muscles by biofeedback training and get exercise the pelvic muscles in physical suppress. The biofeedback training against the physical suppress can have strengthen the pelvic muscles and can display the operation graph of strengthen movement in monitor. Finally, It can be ensured the safety through EMI and performance test.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.295-303
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• 2016

Rehabilitation of upper limb motor function of hemiplegic patient must maintain interest and demand a device for a quantitative evaluation of rehabilitation training. In this paper, we developed the device that is composed of arm cradle, handle, and balance ball for rehabilitation exercise. We have performed experiment for validity as to whether to use the rehabilitation device when tilting the upper extremity training device developed to measure changes in the EMG signal to the main upper limb muscles for 7 healthy volunteers. We have analyzed muscle activation signals on agonist and antagonist as a reference in the muscle contraction and relaxation in the upper limb extension and flexion when the balance-handle device is tilted to front-rear and left-right. The experimental results showed that a tendency of muscle activation of biceps, triceps, and deltoid used in upper limb motor function of hemiplegic patients from extension and flexion evaluation items of Fugl-Meyer Assessment(FMA). These results may be helpful for rehabilitation training for upper limb motor function of hemiplegic patients by utilizing a developed unit.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.61-61
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• 2003

Aquaporins (AQPs)는 다양한 상피세포와 내피세포에 존재하며 다량의 물 수송을 촉진하는 막성단백질로 현재 11개의 AQP가 (AQP0-10) 발견되었으나, 아직 생리적, 기능적 분석은 불충분한 상태이다. 생쥐의 자궁내막은 발정주기 동안 호르몬의 자극에 따라 부풀어오르거나 수축하는 변화를 보이며 에스트로젠과 몇몇 혈관에 작용하는 매개체에 의해 자궁 혈관의 투수성이 증가한다는 보고는 있으나, 자궁액의 수송 메커니즘에 대해서는 뚜렷하게 밝혀진 바가 없다. 발정기의 생쥐 자궁은 자궁내막세포의 증식과 함께 수화되는 특징을 보이며 자궁내강으로 물이 수송되어 luminal fluid의 점성이 낮아지는 현상이 나타나는데, 이 때 AQP가 water channel로서 중요한 역할을 할 것으로 보고 본 실험에서는 면역조직화학법(immunohistochemistry)과 역전사중합효소연쇄반응(Reverse-transcriptase polymerase chain reaction)을 통해 발정기 자궁의 수화와 AQP 발현의 상관성에 대해 알아보고자 하였다. 면역조직화학법의 결과 발정주기의 다른 시기에 비해 발정기(estrus phase)에 자궁상피세포에 AQP4, 5, 8 protein이 다량 존재하는 것으로 밝혀졌고, 근육층(myometrium)에서의 발현은 발정주기 동안 차이가 없었다. Whole uterus로 RT-PCR을 수행한 결과 AQP4, 5, 8 mRNA는 luteal phase에 비해 follicular phase에 더 많이 발현하는 것으로 확인되었다. 또한 LCM(Laser Capture Microdissection) system을 이용하여 luminal epithelium과 stromal cell을 분리하여 RT-PCR을 수행한 결과 AQP4, 5, 8 mRNA는 stromal cell 보다는 luminal epithelium에 더 많이 발현하며, 이 역시 follicular phase에 발현량이 증가함을 확인하였다. 이러한 결과로 미루어 생쥐 자궁에서 AQP4, 5, 8은 발정주기 내막에 발현이 증가하며 이는 자궁내강 안으로 수분을 수송하는데 주요한 기작으로 사료되며 estrogen에 의한 조절 가능성을 암시한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.545-550
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• 2010

Freeman-Sheldon Syndrome (FSS, also known as "Whistling Face Syndrome") is a rare genetic condition which characteristically includes a small "whistling" mouth, a flat mask-like face, club feet, joint contractures usually involving the fingers and hands, and under-development of the cartilage of the nose. Intelligence is usually normal. Most of the features of this syndrome are due to muscle weakness. The patient, 11 years old boy was consulted from pediatrics to pediatric dentistry due to dental management. After clinical & radiographic examinations, severe multiple problems were found. Dental problems were microsomia(whistling mouth) & micrognathia, perioral muscle contracture, restricted mouth opening, poor oral hygiene & care, generalized dental caries, high palatal vault, severe malocclusion & crowding. And Orthopedic problems, ophthalmic & respiratory, anesthetic problems were found. Then He also had psychiatric problem, hospital(dental) phobia due to previous medical history(frequent hospitalization). And he had genital problem, cryptochidism, too. Due to these intricate problems, he suffered with feeding, swallowing difficulties and showed growth retardation. For enhancing patient's oral health, pediatric dentist, orthodontist, oral surgeon, pediatrician, psychiatrist, orthopedist, they all agree with early, cautious intervention and treatment. So, he has been treated by multidisciplinary care, now he is recovering general health maintenance.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.4
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• pp.123-132
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• 2017

PURPOSE: This study aimed to examine the effects of lumbar stabilization exercise during abdominal hollowing with conscious contraction of the pelvic floor muscles on trunk muscle in healthy twenties subjects. METHODS: The participants were randomly allocated to an experimental group (n=15) and a control group (n=15). The experimental group received lumbar stabilization exercise combined with conscious contraction of the pelvic floor muscles during abdominal hollowing. The control group received lumbar stabilization exercise with abdominal hollowing. Both groups trained with the respective exercise for 30 minutes a day, 3 times a week for 6 weeks. Muscle activation of the external oblique and erector spinae muscles, thickness of the transversus abdominis and multifidus, and contraction holding time of tranversus abdominis were measured before and after exercise. RESULTS: Activations of both the external oblique muscles were significantly decreased, and thickness of both the transversus abdominis and multifidus muscles, and contraction holding time of the transversus abdominis muscle were significantly increased in the experimental group (p<.05). The thickness of the left transversus abdominis and right multifidus muscles, and the contraction holding time of the transversus abdominis muscle significantly increased in the control group (p<.05). On comparing both groups, the activations of both external oblique muscles were significantly reduced and the contraction holding time of the transversus abdominis muscle was significantly increased in the experimental group (p<.05). CONCLUSION: These results suggest that lumbar stabilization exercise by abdominal hollowing and conscious contraction of the pelvic floor muscles is suitable and efficient for healthy twenties subjects.