• Title/Summary/Keyword: Surface Activity

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A Effect of the Shoulder Stabilizer Muscle Activity During a Push-up-Plus on a Different Condition Surface (다른 지면 조건에서의 푸시업 플러스 운동이 어깨 안정근의 근 활성도에 미치는 영향)

  • Kim, Jin-Seop;Lee, Dong-Yeop
    • Journal of Digital Convergence
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    • v.10 no.1
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    • pp.399-405
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    • 2012
  • The purpose of this study was to compare the shoulder stabilizer muscle activity during a push up plus on a different conditioning surface. Eighteen healthy volunteers were tested. Surface EMG was recorded from the upper trapezius(UT), pectoralis major(PM), and serratus anterior(SA) using surface differential conditions. Measurements were performed for 7 days. The mean root mean square (RMS) of EMG activity was calculated. A one-way repeated measures analysis of variance was performed to compare RMS normalized values. The UT and PM did not show significant differences of electric activation amplitude in relation to different surface conditions(p>.05). However, the SA showed greater mean electric activation amplitude values on the push up plus exercise on a upper and lower unstable surface(p<.05). These results suggest that to improve SA EMG activity is more useful when performed on a upper and lower unstable surface conditions than on a stable surface conditions.

Antioxidant Activity and Phenolic Content of Different Parts of Lotus and Optimization of Extraction Condition using Response Surface Methodology

  • Jang, Jae Young;Ahn, Jong Hoon;Jo, Yang Hee;Hwang, Bang Yeon;Lee, Mi Kyeong
    • Natural Product Sciences
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    • v.25 no.1
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    • pp.44-48
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    • 2019
  • Nelumbo nucifera Gaertn. (Nymphaeaceae) is commonly called lotus and its leaves are widely been used as functional ingredients due to its antioxidant activity. For maximum efficacy, optimized extraction condition was established using response surface methodology. The high F-values, low p-values and insignificant p-value for lack-of-fit supported the fitness of the model and yielded the second-order polynomial regression for the antioxidant activity. The optimized extract was obtained by the extraction of 1 g of lotus leaves with 40 mL of 50% MeOH at $10.0^{\circ}C$, which exerted 70.1% antioxidant activity. Close correlation between phenolic content and antioxidant activity suggested phenolic compounds as active constituents of lotus leaves. In addition, comparison of different parts of lotus demonstrated the most potent antioxidant activity of flowers, followed by leaves and roots. Taken together, these results provide useful information about lotus leaves for the development as antioxidant ingredients. In addition, flowers and roots as well as leaves are suggested as good sources for antioxidant activity.

Visualization of Motor Unit Activities in a Single-channel Surface EMG Signal

  • Hidetoshi Nagai
    • International journal of advanced smart convergence
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    • v.12 no.3
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    • pp.211-220
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    • 2023
  • Surface electromyography (sEMG) is a noninvasive method used to capture electrically muscle activity, which can be easily measured even during exercise. The basic unit of muscle activity is the motor unit, and because an sEMG signal is a superposition of motor unit action potentials, analysis of muscle activity using sEMG should ideally be done from the perspective of motor unit activity. However, conventional techniques can only evaluate sEMG signals based on abstract signal features, such as root-mean-square (RMS) and mean-power-frequency (MPF), and cannot detect individual motor unit activities from an sEMG signal. On the other hand, needle EMG can only capture the activity of a few local motor units, making it extremely difficult to grasp the activity of the entire muscle. Therefore, in this study, a method to visualize the activities of motor units in a single-channel sEMG signal by relocating wavelet coefficients obtained by redundant discrete wavelet analysis is proposed. The information obtained through this method resides in between the information obtained through needle EMG and the information obtained through sEMG using conventional techniques.

Moisture Sorption Isotherm and Quality Deterioration of Dry Jujube (건대추의 등온흡습곡선 및 품질열화특성)

  • 김영숙;안덕순
    • Food Science and Preservation
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    • v.4 no.1
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    • pp.33-38
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    • 1997
  • In order to provide informations for designing packaging and storage condition of dry jujube (Zizyphus jujuba MILLER), moisture sorption isotherm was determined for temperatures of 20, 30 and 4$0^{\circ}C$, and quality changes were evaluated as function of temperature and water activity. Dry jujube at a given water activity showed higher equilibrium moisture content for lower temperature. Moisture isothem could be fitted by GAB model equation, giving higher C value, lower m0 and relatively constant k value with increase in temperature. Ascorbic acid was lost more highly at higher temperature and water activity, and showed negligible retention for whole range of water activity and temperature studied after 141 days. Browning increased with water activity up to 0.73 at 30 and 4$0^{\circ}C$. Dry jujube of high water activity had high L value in surface color, which represent brightness of surface color. Considering quality retention in the storage, dry jujube is desired to be dried to water activity of 0.42 and be stored at temperature below 3$0^{\circ}C$

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Effect of Task-Oriented Training According to the Support Surface on Pain, Function, Balance Ability, Muscle Activity and Muscle Thickness in Patients with Ankle Instability (지지면에 따른 과제 지향적 훈련이 발목 불안정성 환자의 통증과 기능 수준, 균형능력, 그리고 근 활성도 및 근 두께에 미치는 영향)

  • Oh, Youn-jung;Park, Jong-hang;Park, Sam-ho
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.28 no.1
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    • pp.29-38
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    • 2022
  • Background: Task-oriented training on an unstable support surface is an effective intervention for improving the ankle joint stability and muscle strength in patients with ankle instability. This study examined the effects of balance training on an unstable support surface in patients with ankle sprains with ankle instability. Methods: Forty-four patients with ankle sprains participated in this study. Screening tests were performed and assigned to an experimental group, who performed task-oriented training on an unstable support surface (n=22), and a control group, who performed task-oriented training on a support surface (n=22) using a randomization program. All interventions were applied 3 times per week for 4 weeks. The numeric rating scale (NRS), cumberland ankle instability tool (CAIT), balance ability, muscle activity, and muscle thickness were compared to evaluate the effects of the intervention. Results: Both groups showed significant differences in the NRS, CAIT, balance ability, and muscle activity between before and after the intervention (p<.05). In addition, there were significant differences in balance ability, muscle activity, and muscle thickness between the experimental and control groups (p<.05). Conclusion: Task-oriented training on an unstable support surface is an effective intervention for improving the balance ability, muscle activity, and muscle thickness during contraction.

Amylase Production by Continuous Cultures of Aspergillus oryzae and its Mutants (Aspergllus oryza와 그 변이주의 연적배양에 의한 amylase 생성에 관한 연구)

  • Han, Hong-Eui
    • Korean Journal of Microbiology
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    • v.15 no.2
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    • pp.63-76
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    • 1977
  • Irradiation with high doses of gamma rays induced the reduction of mycelial weight and anaylase activity, and increased relative amylase activity in surface cultures. Biphase in growth curves was shown in aeration-agitation cultures but the behavior of the first phase of growth could be eliminated by replacing the amylasehydrolysed starch substrates, so that enzyme production was shortened ca. 40 hours and relative amylase activity was increased about 3 times higher before onset of autolysis. In the effect of gibberellin on amylase production, the positive stimulation was appeared to only surface culturs of the liquid medium and the negative effect to shake-cultures in a mutant. Trials of various continuous culture were resulted not only the approalch to the value of amylase activity in surface cultures of liquid medium, but also higher productivity than in batch cultures. The culture-degeneration was observed in two-stage continuous culture, but did not appear in continuous elevation culture.

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Trunk Stabilization Muscle Activity in Chronic Low Back Pain Patients during One Leg Stance (만성요통환자의 한발서기 시 체간 안정화 근육의 활성화 변화)

  • Min, Dong-ki
    • Journal of Korean Physical Therapy Science
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    • v.21 no.1
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    • pp.13-20
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    • 2014
  • Purpose : The purpose of this study was to analyze and compare the surface electromyography(EMG) activity of trunk region muscle between normal subjects and chronic low back pain(CLBP) patients during one leg stance. Methods : The subjects were 27 people, were consisted of 12 subjects who don't have low back pain and 15 subjects who have low back pain from 19 to 28 year of age(mean age 22.22). We used surface EMG to evaluate the activity of the Rectus abdominis, External abdominal oblique, Quadratus lumborum, Gluteus medius muscle. We used independent two samples t-test for statistical data. Results : The result of this study showed that the maximal voluntary isometric contraction(%MVIC) ratio of the trunk muscles was higher in patients with CLBP than in normal subject. But there were no statistically significant differences. There were statistically significant differences of the activity of the Quadratus lumborum, Gluteus medius muscle(p<0.05).

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The Effects of Lower Muscle Activity of Squat Exercise on Supporting Surface and Visual Feedback (지지면과 시각적 피드백의 차이에 따른 스쿼트 운동시 일부 하지 근 활성도에 미치는 영향)

  • Lee, Jin;Bang, Hyun-Soo
    • Journal of Korean Physical Therapy Science
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    • v.25 no.1
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    • pp.20-30
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    • 2018
  • Background: This study evaluates the effects of lower muscle activity of squat exercise on supporting surface and visual feedback. Methods: The subjects include 30 healthy subjects. To measure muscle activation of the lower limb during squat exercise(stable and unstable surface, visual and unvisual). For evaluation of muscle activation(rectus femoris, biceps femoris), was measured using the Electromyogram, EMG was used. Results: The results shows that Rectus Femoris(RF) and Biceps Femoris(BF) muscle activations were significantly (p<0.05) difference in unvisual-unstable surface(USUV), unvisual-stable surface(SUV), visual-unstable surface(USA), and visual-stable surface(SV) during squat exercise. Conclusion: Squat exercise can improve muscle activation of the lowe limb. particularly, unvisual-unstable surface during squat exercise can improve muscle activation of the lowe limb.

Surface Properties and interfacial Potential Distribution of Surface Treated-Alumina (표면처리한 알루미나의 표면물성과 계면전위분포)

  • 홍영호;함영민
    • Journal of the Korean Ceramic Society
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    • v.33 no.7
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    • pp.823-831
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    • 1996
  • Due to the intrinsic low surface activation of ${\gamma}$-alumina it has been used limitely in practice. Accordingly forward enhancing its utility ${\gamma}$-alumina surface was treated with slfuricf aicd nitric acid and chloric acid respec-tively. Subsequently the effects of surface activity on the surface electrical characteristics were investigated. The ${\gamma}$-alumina was prepared by the precipitation of aluminium nitrate [Al(NO3)3.9H2O] using ammonia water as a precipitator and it was chemically treated with such acids mentioned above. The surface and morphology of the acid-treated ${\gamma}$-alumina were analysed by XRD, BET and the surface activities were measured by the amine titration methods. The interfacial properties of the ${\gamma}$-alumina dispersed in electrolyte solution were esti-mated by the surface charge density measured using potentiometric tiration. Based on the relation between surface charge density and the acid amount the following results were drawn for the surface and interfacial electrical properties ; Acidic properties of surface-treated alumina increase with anion load on alumina surface. P. Z. C decreases with acid amount on alumina surface. The surface charge densities were apart from electrolyte ionic strength. The acidity of ${\gamma}$-alumina is linearly dependent on the P. Z,.C when the ${\gamma}$-alumina was dispersed in aqueous electrolyte solution.

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Surface characteristics and bioactivity of an anodized titanium surface

  • Kim, Kyul;Lee, Bo-Ah;Piao, Xing-Hui;Chung, Hyun-Ju;Kim, Young-Joon
    • Journal of Periodontal and Implant Science
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    • v.43 no.4
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    • pp.198-205
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    • 2013
  • Purpose: The aim of this study was to evaluate the surface properties and biological response of an anodized titanium surface by cell proliferation and alkaline phosphatase activity analysis. Methods: Commercial pure titanium (Ti) disks were prepared. The samples were divided into an untreated machined Ti group and anodized Ti group. The anodization of cp-Ti was formed using a constant voltage of 270 V for 60 seconds. The surface properties were evaluated using scanning electron microscopy, X-ray photoelectron spectroscopy, and an image analyzing microscope. The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were analyzed. Cell adhesion, cell proliferation, and alkaline phosphatase activity were evaluated using mouse $MC_3T_3-E_1$ cells. Results: The anodized Ti group had a more porous and thicker layer on its surface. The surface roughness of the two groups measured by the profilometer showed no significant difference (P>0.001). The anodized Ti dioxide ($TiO_2$) surface exhibited better corrosion resistance and showed a significantly lower contact angle than the machined Ti surface (P>0.001). Although there was no significant difference in the cell viability between the two groups (P>0.001), the anodized $TiO_2$ surface showed significantly enhanced alkaline phosphatase activity (P<0.001). Conclusions: These results suggest that the surface modification of Ti by anodic oxidation improved the osteogenic response of the osteoblast cells.