• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.166-167
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• 2006

Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L-films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for Impression.

• Annals of Clinical Neurophysiology
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• v.12 no.2
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• pp.35-46
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• 2010

Various electrophysiological tests have provided a large body of valuable information on neuronal responses to a presented stimulus. The special and general somatic sensory pathways are main targets of evoked potentials. Two types of evoked potentials, exogenous and endogenous, are commonly used. Exogenous evoked potentials of general and special somatic sensory systems will be reviewed. One of general somatic sensory functional pathways, proprioception, can be evaluated by general somatosensory evoked potentials with electrical stimulation on nerves. The special somatosensory functional pathways, including vision, and audition, can be evaluated by visual evoked potentials and auditory evoked potentials. Also laser-evoked potentials are newly developed for pain pathway, including lateral spinothalamic pathway, and vestibular myogenic evoked potentials for sacculocollic pathways. The evoked potentials of sensory system have maximal clinical utility in evaluating functional deficits along the sensory pathways. They are used for evaluating comatose patients, hysterical patients, premature infants, patients with suspected demyelinating diseases or neoplasms, and research. We discuss the neurophysiologic tests of sensory systems in views of practical points. The organized evaluation of sensory electrophysiologic tests can be helpful in detecting and estimating the abnormalities in neurological diseases.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.755-760
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• 2015

For proper wound healing, dermal contraction and remodeling are critical; during the natural healing process, differentiated fibroblasts called "myofibroblasts" typically undertake these functions. For severe wounds, however, a critical mass of dermal matrix and fibroblasts are lost, making self-regeneration impossible. To overcome this impairment, synthetic wound patches with embedded functional cells can be used to promote healing. In this study, we developed a polydioxanone (PDO)-based cell-embedded sheet on which dermal fibroblasts were cultured and induced for differentiation into myofibroblasts, whereby the following combinatorial physicochemical stimuli were also applied: aligned topology, electric field (EF), and growth factor. The results show that both the aligned topology and EF synergistically enhanced the expression of alpha smooth-muscle actin (${\alpha}$-SMA), a key myofibroblast marker. Our proof-of-concept (POC) experiments demonstrated the potential applicability of a myofibroblast-embedded PDO sheet as a wound patch.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.21-27
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• 2020

PURPOSE: This study investigated the efficacy of interferential current (IFC) treatment on the improvement of pain, disability, and balance in patients with chronic nonspecific low back pain. METHODS: A double-blind randomized clinical trial was conducted with 40 patients with chronic nonspecific low back pain. The patients were randomly allocated into two groups: the IFC treatment group (n = 20) and the placebo treatment group (n = 20). The IFC group received 30 minutes of IFC treatment on the lumbar region, while the placebo group received IFC treatment without real electrical stimulation. The intervention was administered five days a week for two weeks. RESULTS: The primary outcomes of resting pain and pain during functional movement were measured by a visual analogue scale. The secondary measurements included the Oswestry disability index (ODI) for low back pain and postural sway. The measurements were performed before and after the two-week intervention period. Compared to the placebo treatment group, the IFC treatment group showed significantly greater improvement in pain during anterior trunk flexion in the standing position (p = .029), ODI (p = .039), and postural sway when subjects stood with their eyes closed (p = .010) at the end of the intervention. CONCLUSION: Our findings show that IFC treatment can improve pain, disability, and postural sway, thus, highlighting the benefits of somatosensory stimulation from IFC.

• 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.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.85-98
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• 1991

The aim of this study was to investigate the effect of low - power laser used in the medical field for various purposes to suppress pain responses evoked by noxious electrical or mechanical stimuli. After both inferior alveolar nerves and the left anterior digastric muscle of cats under general anesthesia were exposed, a recording electrode for the jaw opening reflex was inserted into the anterior digastric muscle. The right inferior alveolar nerve was dissected under a surgical microscope until the response of the functional single nerve could be evoked by the electrical stimulation of the dental pulp or oral mucosa. The electrical stimulus was applied with a rectangular pulse of 10 ms duration for measuring the threshold intensity of a single nerve fiber in the inferior alveolar nerve which responds to stimulation of dental pulp and oral mucosa. Then a pulse of 1 ms duration was applied for determination of conduction velocity. A noxious mechanical stimulus to the oral mucosa was applied by clamping the receptive field with an arterial clamp. The Ga-As diodide laser(wave length, 904 nm ; frequency, 1,000 Hz) was irradiated to the prepared tooth cavity, inferior alveolar nerve and oral mucosa as a pulse wave of 2 mW for 6 minutes. This was followed by a continuous wave of 15 mW for 3 minutes. The action potential of the nerve and EMG of the digastric muscle evoked by the noxious electrical stimulus and nerve response to noxious mechanical stimulus were compared at intervals of before, immediately after, and at 5, 10, 20, 40, 60 minutes after laser irradiation. The results were as follows: The conduction velocity of the intrapulpal $A{\delta}$- nerve fiber recorded from the inferior alveolar nerve before irradiation had a mean value of $6.68{\pm}2.07m/sec$. The laser irradiation did not affect the conduction velocity of the AS - nerve fiber and did not change the threshold intensity or amplitude of the action potential either. The EMG of the digastric muscle evoked by noxious electrical stimulation to the tooth was not changed by the laser irradiation, whether in latency, threshold intensity or amplitude. The laser irradiated to the receptive field of the oral mucosa which was subjected to noxious stimuli did not affect the amplitude of the action potential or the frequency either.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.49-56
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• 1972

This experiment was designed to explore specific functional relationship between the vestibular canals and the extraocular oblique muscles by observing the isometric tension responeses of the muscles to the selected vestibular canal excitation. The vestibular excitation was simulated by either stimulation of the individual canal nerve or endolymphatic fluid displacement in each canal. Each canal nerve was subjected to square wave pulses with a monopolar wire electrode placed closely to the ampullary nerve endings for electrical stimulation, and a fine stainless cannula was introduced into the each canal toward the ampulla and a minute amount $(0.5{\sim}3.5\;microliter)$ of fluid was injected in or ejected out by means of a microsyringe connected to the cannula to produce ampullopetal or ampullofugal displacement of endolymphatic fluid. The superior oblique muscle was contracted by the excitation of homolateral canals and was relaxed by contralateral canals. On the contrary, the inferior oblique was contracted by the contralateral canals and was relaxed by the homolateral canals. Summation of excitatory and inhibitory canal effects from the bilateral vestibular system was demonstrable on the tension changes of the oblique muscles. Excitation of either dual or triple canals of the unilateral vestibular system also caused summation effect on the tension response of the oblique pair; thus multiple signals from the different ampullary receptors seems to be converged into the relevant ocular motor muclei. Since the superior and inferior obliques are known to receive their motor fibers from the contralateral trochlear nuclei and intermediate nuclei of the homolateral oculomotor complex respectively, the above experimental evidences indicate that the ocular motor nuclei for oblique muscles receive excitatory signals from the contralateral vestibular canals and inhibitory signals from the homolateral canals.

• The Journal of Korean Physical Therapy
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• v.24 no.2
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• pp.118-126
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• 2012

Purpose: The purpose of this study was to investigate pain relief and functional recovery after total knee replacement. Methods: The treatment was performed by dividing individuals into a control group ($n_1=5$), ultrasound treatment group ($n_2=5$), and micro-current treatment group ($n_3=5$). The control group applied the hot pack for 15 minutes, Transcutaneous Electrical Nerve Stimulation (TENS) for 15 minutes, and Continuous Passive Movement (CPM) for 40 minutes. The ultrasound therapy group applied the frequency of 1 MHz, intensity of 1.0 $W/cm^2$ for five minutes following the same treatment as the control group. The micro-current therapy group applied the intensity of 25 ${\mu}A$, and pulsation frequency 5 pps for 15 minutes following the same treatment as the control group. After treatment, Visual Analogue Scale (VAS), Korean Western Ontario and McMaster Universities Arthritis Index (K-WOMAC), Berg Balance Scale (BBS), Range of Movement (ROM) and wound length was measured. Results: VAS showed significant effect in the control group and micro-current therapy group during the treatment period. According to the treatment of K-WOMACK, BBS, ROM, and Healing wounds showed main effects between groups. Conclusion: According to the results of this study, data showed improvement of pain relief, wound healing effects, and range of motion recovery. Thus, these selected treatments were effective after total knee replacement. In other words, electrical treatment continues to influence pain relief and functional recovery after total knee replacement.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.437-443
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• 2011

Salt signals in tongue are relayed to the nucleus of the solitary tract (NST). This signaling is very important to determine whether to swallow salt-related nutrition or not and suggests some implications in discrimination of salt concentration. Salt concentration-dependent electrical responses in the chorda tympani and the NST were well reported. But salt concentration-dependency and spatial distribution of c-Fos in the NST were not well established. In the present study, NaCl signaling in the NST was studied in urethane-anesthetized rats. The c-Fos immunoreactivity in the six different NST areas along the rostral-caudal axis and six subregions in each of bilateral NST were compared between applications of distilled water and different concentrations of NaCl to the tongue of experimental animals. From this study, salt stimulation with high concentration (1.0 M NaCl) induced significantly higher c-Fos expression in intermediate NST and dorsal-medial and dorsal-middle subregions of the NST compared to distilled water stimulation. The result represents the specific spatial distribution of salt taste perception in the NST.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.133-144
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• 2023

PURPOSE: This study aimed to determine the effects of task-oriented treadmill training on the gait and balance ability and functional activity in 20 patients with subacute stroke. METHODS: The study subjects were twenty stroke patients, ten randomly placed in the experimental group and ten in the control group. Both the experimental and control groups received 30 minutes of traditional physical therapy and an additional 15 minutes of functional electrical stimulation therapy. The experimental group was given task-oriented treadmill training, while the control group received general treadmill training. Each session lasted for 25 minutes, three times a week, over four weeks, totaling 12 sessions. RESULTS: Both groups showed statistically significant differences in the 10-metre walk test (10MWT), timed up and go test (TUG), Fugl-Meyer Assessment (FMA), and Modified Barthel index (MBI). However, statistically significant differences in the Functional Ambulation Categories (FAC) and Berg Balance Scale (BBS) were seen only in the experimental group. There were statistically significant differences in the between-group differences value comparisons in the 10MWT, BBS, TUG, FMA, and MBI. CONCLUSION: Task-oriented treadmill training positively impacts gait, balance, and daily function in subacute stroke patients. This study highlights the benefits of training on unstable surfaces and offers valuable insights for stroke rehabilitation and gait training.