• Title/Summary/Keyword: muscle contraction

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Effect of Abdominal Draw In Maneuver in Sitting Position (앉은자세에서 실시하는 복부드로우인기법의 효과)

  • Kim, Seon-Chil;Kim, Shin-Gyun;Kim, Chang-sook
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.11 no.3
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    • pp.207-214
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    • 2017
  • The problem of trunk stability is a major factor in back pain.. Abdominal draw in maneuver(ADIM), One of the trunk stabilization exercises to relieve lumbar instability, is a method of inducing selective contraction of the transverse abdominis associated with anticipatory posture control among the abdominal stabilization muscles. ADIM is usually performed with a visual feedback by applying a pressure biofeedback unit(PBU) under the lumbar at the supine position, which is not functional compared to the sitting position. This study was conducted to investigate the effect of ADIM applied in supine and sitting position on 31 healthy men and women. In each posture, muscle activity was measured by rectal abdominis (RA), external oblique (EO), transverse abdominis (TrA)/internal obilique (IO) and erector spinae (ES) using wireless EMG. In the result, there was no significant difference between RA and EO between the two postures and there was a significant difference between TrA / IO and ES. In both postures, the activity of TrA/IO was higher than that of RA, and the effect of ADIM was shown to be the same, whereas TrA/IO and ES showed higher activity in sitting position. This means that the activity of the muscles involved in the postural stability and lumbar stability is increased further in the sitting position. Therefore, ADIM in sitting, which can be applied more easily in daily life, is useful for improving lumbar stability.

Postnatal Development of Echolocation Vocalizations in the Serotine Bat, Eptesicus serotinus (Chiroptera: Vespertilionidae) (문둥이박쥐(Eptesicus serotinus)의 생후 반향정위 발성 발달에 관한 연구)

  • Chung, Chul-Un;Han, Sang-Hoon;Kim, Sung-Chul;Lim, Chun-Woo;Cha, Jin-Yeol
    • Korean Journal of Environment and Ecology
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    • v.29 no.6
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    • pp.858-864
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    • 2015
  • Developmental changes in the vocal signals of serotine bats (Eptesicus serotinus) during their infancy were examined in this study. The analysis was conducted on 4 infant serotine bats from 1 to 40 days after their birth. Pulse duration (PD), pulse interval (PI), peak frequency (PF), maximum frequency ($F_{MAX}$), minimum frequency ($F_{MIN}$), and bandwidth (BW) were measured. As the bats grew, their vocalizations became increasingly consistent and similar to those of adults. For infant bats, PD and PI decreased as they grew older, whereas PF, $F_{MAX}$, $F_{MIN}$, and BW increased. The greatest change in vocalizations was observed between the $10^{th}$ and $20^{th}$ days after birth. Also, PF, $F_{MAX}$, $F_{MIN}$ and BW, which describe sound frequency, increased dramatically during the period between the $10^{th}$ and the $20^{th}$ days. In contrast, the greatest change in PD occurred between the $30^{th}$ and $40^{th}$ days after birth. The results collected in this study suggest that frequency increased as the contraction ability of the muscles developed by around 20 days of age. Muscle relaxation ability, which is related to PD, was found to develop significantly at 30 to 40 days of age. According to the results of this study, although 40 day-old infant bats are not yet able to fly, their vocal signals were similar to those of adults. This indicates that vocal development and flying activity develop separately in young bats.

Bioactivity of an Extract of Lespedezea Cuneata G. Don to Rabbit Corpus Cavernosum Smooth Muscle Tone (야관문(Lespedezea cuneata G. Don) 추출물이 토끼 음경해면체 평활근에 미치는 생리활성)

  • Chung, Young-Ho;Lim, Chi-Hwan
    • Korean Journal of Agricultural Science
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    • v.32 no.1
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    • pp.63-70
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    • 2005
  • The extracts in n-hexane layer from Lespedezea cuneata G. Don exelled at sexual activity according to in vitro experiment using biopsy of rabbit corpus cavernosum to investigate effects on sexual function. The extracts were injected into 9 samples at $10{\mu}l$. The lowest relaxation was showed at sample C, $4.8{\pm}1.4%$ and the highest relaxation was showed at sample A, $20.2{\pm}6.0%$. The relaxation by every sample, except sample C and G-1, were higher than by $10^{-7}M$ ACh, $7.8{\pm}5.1%$, and their effects were above 10%. Also, the extracts were injected into 9 samples at $15{\mu}l$. The lowest relaxation was showed at sample C, $15.4{\pm}9.7%$ and the highest relaxation was showed at sample J, $54.8{\pm}9.7%$. The relaxation by sample A and D was as much as by $10^{-6}M$ ACh, $28.0{\pm}20.1%$. The relaxation by sample H was $41.9{\pm}7.3%$. The relaxation by sample J was $54.8{\pm}9.7%$ and it was higher than by $10^{-5}M$ ACh, $53.9{\pm}25.9%$. Also, the extracts were injected into 9 samples at $20{\mu}l$. The lowest relaxation was showed at sample E, $28.9{\pm}0.6%$ and it was a little higher than by $10^{-6}M$ ACh. The relaxation by sample G was as much as by $10^{-5}M$ ACh. The two higher relaxation were showed at sample H, $99.4{\pm}16.0%$ and J, $95.7{\pm}7.2%$, and their relaxation against contraction reaction by PhE were near 100%. Experiment by sample I was not performed for lack of sample amount.

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COMPARISON OF BITE FORCE WITH DENTAL PRESCALE AND UNILATERAL BITE FORCE RECORDER IN HEALTHY SUBJECTS (Dental Prescale과 편측 교합력 측정기를 이용한 정상성인의 교합력 비교)

  • Kwon Ho-Keun;Yoo Ja-Hea;Kwon Young-Sook;Kim Baek-Il
    • The Journal of Korean Academy of Prosthodontics
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    • v.44 no.1
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    • pp.103-111
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    • 2006
  • Statement of problem: The previous unilateral bite force recorder has several limitations for taking long time for measuring and causing discomfort to subjects. Because of these reasons, it could not use widely for epidemiological researches. However, 'Dental Prescale System' which is new equipment for measuring bite force, is more convenient for measuring bite force than previous unilateral recorder. Purpose: The purpose of this study was to compare a new technique(Dental Prescale System) using pressure sensitive foils for recording of maximal jaw closing force with conventional measurement using unilateral bite force recorder Material and method: This studies included 22 healthy dental students in college of dentistry Yonsei university in Rep of Korea. Mean age was 23.9 years. All subjects had continuous dental arches and no significant malocclusion or signs from the teeth and craniomandibular system. The Dental Prescale System (Fuji Film, Tokyo, Japan) consists of a horseshoe-shaped pressure sensitive sheet (50H, R type) and a computerized scanning system.(FPD705) We also used unilateral bite force recorder(Denbotics Co. Seoul, Rep.Korea) for comparing with Dental Prescale. Results and conclusion: The total bite force recorded with Dental Prescale System (1423 N) was systematically higher than that recorded by unilateral bite force recorder. (256 N) However, the maximum bite force values measured in the two ways were significantly correlated (r=0.46, p<0.05). The Dental Prescale bite force calculated for first molar (208 N) was lower than that recorded by unilateral bite force recorder. (256 N) The two values were also very significantly correlated. (r=0.66. p<0.001) There were significantly different in bite force between two measurement methods. The reasons were first, unilateral bite force recorder measured only the bite force of a part of teeth, and Dental Prescale measured the total teeth force. Second, in measurement, a difference in muscle contraction appeared by an extent of mouth-opening. Third, unilateral bite force recorder has the reducing effect of the bite force by protective tape. Fourth, Dental Prescale has limitations during the computer scanning procedure. Therefore, Dental Prescale System is considered to be a very promising alternative to be conventional bite force recording methods.

Human-Computer Interface using sEMG according to the Number of Electrodes (전극 개수에 따른 근전도 기반 휴먼-컴퓨터 인터페이스의 정확도에 대한 연구)

  • Lee, Seulbi;Chee, Youngjoon
    • Journal of the HCI Society of Korea
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    • v.10 no.2
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    • pp.21-26
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    • 2015
  • NUI (Natural User Interface) system interprets the user's natural movement or the signals from human body to the machine. sEMG (surface electromyogram) can be observed when there is any effort in muscle even without actual movement, which is impossible with camera and accelerometer based NUI system. In sEMG based movement recognition system, the minimal number of electrodes is preferred to minimize the inconvenience. We analyzed the decrease in recognition accuracy as decreasing the number of electrodes. For the four kinds of movement intention without movement, extension (up), flexion (down), abduction (right), and adduction (left), the multilayer perceptron classifier was used with the features of RMS (Root Mean Square) from sEMG. The classification accuracy was 91.9% in four channels, 87.0% in three channels, and 78.9% in two channels. To increase the accuracy in two channels of sEMG, RMSs from previous time epoch (50-200 ms) were used in addition. With the RMSs from 150 ms, the accuracy was increased from 78.9% to 83.6%. The decrease in accuracy with minimal number of electrodes could be compensated partly by utilizing more features in previous RMSs.

Baseline Wander Removing Method Based on Morphological Filter for Efficient QRS Detection (효율적인 QRS 검출을 위한 형태 연산 기반의 기저선 잡음 제거 기법)

  • Cho, Ik-Sung;Kim, Joo-Man;Kim, Seon-Jong;Kwon, Hyeog-Soong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.1
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    • pp.166-174
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    • 2013
  • QRS detection of ECG is the most popular and easy way to detect cardiac-disease. But it is difficult to analyze the ECG signal because of various noise types. The important problem in recording ECG signal is a baseline wandering, which is occurred by rhythm of respiration and muscle contraction attaching to an electrode. Particularly, in the healthcare system that must continuously monitor people's situation, it is necessary to process ECG signal in realtime. In other words, the design of algorithm that exactly detects QRS region using minimal computation by analyzing the person's physical condition and/or environment is needed. Therefore, baseline wander removing method based on morphological filter for efficient QRS detection method is presented in this paper. For this purpose, we detected QRS through the preprocessing method using morphological filter, adaptive threshold, and window. The signal distortion ratio of the proposed method is compared with other filtering method. Also, R wave detection is evaluated by using MIT-BIH arrhythmia database. Experiment result show that proposed method removes baseline wanders effectively without significant morphological distortion.

Treatment of Mid-trimester Oligohydramnios Using Gami-danggui-san (임신중기(姙娠中期)에 나타난 양수과소증(oligohydramnios)에 가미당귀산(加味當歸散)을 투여하여 효과를 보인 증례보고)

  • Kim, Hyo-Jung;Kim, Eun-Seop;Jin, Dae-Hwan;Hwang, Deok-Sang;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.32 no.1
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    • pp.85-93
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    • 2019
  • Objectives: The aim of this study was to demonstrate the benefit of Traditional Korean Medicine as an adjuvant therapy in management of mid-trimester oligohydramnios. Methods: It is a case report of a 31 year-old woman hospitalized for oligohydramnios at $24^{+4/7}$weeks of gestation. This patient diagnosed with special oligohydramnios had no abnormal findings such as fetal urinary abnormalities or other anomalies. Also, symptom of PPROM (preterm premature rupture of membrane) was not confirmed. The decoction, Gami-danggui-san (DG) was prescribed for the purpose of reducing unnecessary contraction of uterine muscle during pregnancy and promoting blood circulation and metabolism, thereby improving placental function and contributing to the increase of the fluid. DG decoction was administered twice a day until 19th of June, which was 10 days in total. During the treatment, level of amniotic fluid had been monitored by measuring AFI (amnioti fluid index). Results: After these conventional therapies, the amount of amniotic fluid increased steadily, and eventually reached the optimal level. AFI was found to be 3.2 on the $24^{+4/7}$ weeks, 8 on the $26^{+1/7}$ weeks, 11.5 on the $27^{+0/7}$ weeks of gestation. In the same periods, EFW (expected fetal weight) was also found to be increasing gradually: 545 g, 630, and 760 g. Conclusions: Our report implies the potential of herbal medicine as a effective therapy for oligohydramnios tratment. Further studies are needed to assess the efficacy of TKM herbal medicine and reveal the mechanisms of the decoction.

Acetylation of Sarcoplasmic and Myofibrillar Proteins were Associated with Ovine Meat Quality Attributes at Early Postmortem

  • Zhang, Yejun;Li, Xin;Zhang, Dequan;Ren, Chi;Bai, Yuqiang;Ijaz, Muawuz;Wang, Xu;Zhao, Yingxin
    • Food Science of Animal Resources
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    • v.41 no.4
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    • pp.650-663
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    • 2021
  • The objective of this study was to examine the relationship between meat quality attributes and the changes of sarcoplasmic protein acetylation and myofibrillar protein acetylation in lamb longissimus thoracis et lumborum muscles at different postmortem phases. Protein acetylation, color, pH, shear force, myofibril fragmentation index and cooking loss were measured. The total level of acetylated sarcoplasmic proteins showed a negative relation with pH, a positive relation with a*, b* and cooking loss at the pre-rigor phase. Sarcoplasmic proteins acetylation affected postmortem pH by regulating glycolysis, which in turn affects color and cooking loss. The total level of acetylated myofibrillar proteins showed a positive relation with shear force at the pre-rigor phase. Myofibrillar proteins acetylation affected meat tenderness by regulating muscle contraction. This study indicated that acetylation played a regulatory role of meat color, water-holding capacity, and tenderization process at early postmortem.

A Convergence Study of Surface Electromyography in Swallowing Stages for Swallowing Function Evaluation in Older Adults: Systematic Review (노인의 삼킴 단계별 삼킴 기능 평가를 위한 표면 근전도 검사의 융합적 연구 : 체계적 문헌고찰)

  • Park, Sun-Ha;Bae, Suyeong;Kim, Jung-eun;Park, Hae-Yean
    • Journal of the Korea Convergence Society
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    • v.13 no.5
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    • pp.9-19
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    • 2022
  • In this study, a systematic review was conducted to analyze the method of applying sEMG to evaluate the swallowing function of the elderly at each stage of swallowing, and to help objectively measure the swallowing stage of the older adults in clinical practice. From 2011 to 2021, 7 studies that met the selection criteria were selected using Pubmed, Scopus, and Web of Science (WoS). As a result of this study, the older adults and adults were divided into an experimental group and a control group and the swallowing phase was analyzed using sEMG only for the older adults. sEMG was used to evaluate swallowing in the oral and pharyngeal stages, and the sEMG attachment site was attached to the swallowing muscle involved in each stage. The collected sEMG data were filtered using a bandpass-filter and a notch-filter, and were analyzed using RMS, amplitude, and maximum spontaneous contraction. In this study, it was found that sEMG can be used as a tool to objectively and quantitatively evaluate the swallowing function in stages. Therefore, it is expected that this study will activate various studies that incorporate sEMG to evaluate the swallowing function in stages.

Extracellular $K^+$ Effects on the Mouse Aortic Endothelial Cell Contractility (쥐 대동맥 혈관 내피세포에서 세포 외 $K^+$에 의한 혈관 수축선 조절 기전)

  • 안재호;유지영
    • Journal of Chest Surgery
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    • v.36 no.12
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    • pp.887-893
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    • 2003
  • External stimuli increases intracellular (IC) $Ca^{2+}$, which increases extracellular (EC) $K^{+}$. To verify $K^{+}$ effects on the vascular contraction, we performed an experiment using mouse aortic endothelial cell. Meterial and Method: We examined the mouse aortic contractility changes as we measured the IC $Ca^{2+}$ change and ionic current by using the voltage clamp technique under different conditions such as: increasing EC $K^{+}$, removing endothelial cell, giving L-NAME (N-nitro-L-arginine methyl ester) which suppress nitric oxide formation, Ouabain which control N $a^{+}$ - $K^{+}$ pump and N $i^{2+}$ which repress N $a^{+}$-C $a^{2+}$ exchanger Result: When we increased EC $K^{+}$ from 6 to 12 mM, there was no change in aortic contractility. Aorta contracted with more than 12 mM of EC $K^{+}$. Ace-tylcholine (ACh) induced relaxation was inhibited with EC $K^{+}$ from 6 to 12 mM, but was not found after de-endothelialization or L-NAME treatment. ATP or ACh increased IC $Ca^{2+}$ in cultured endothelium. After maximal increase of IC $Ca^{2+}$, increasing EC $K^{+}$ from 6 to 12 mM made IC $Ca^{2+}$ decrease and re-decreasing EC $K^{+}$ to 6 mM made IC $Ca^{2+}$ increase. Ouabain and N $i^{2+}$ masked the inhibitory effect of endothelium dependent relaxation by increased EC $K^{+}$. Conclusion: These data indicate that increase in EC $K^{+}$ relaxes vascular smooth muscle and reduces $Ca^{2+}$ in the endothelial cells which inhibit endothelium dependent relaxation. This inhibitory mechanism may be due to the activation of N $a^{+}$- $K^{+}$ pump and N $a^{+}$-C $a^{2+}$ exchanger. $a^{+}$-C $a^{2+}$ exchanger.r.