• Title/Summary/Keyword: surface activation

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Comparison of the Effects of Different Adduction Loads on EMG Activities of Selected Shoulder Muscles During Shoulder External Rotation Exercise in Healthy Young People

  • Peng, Cheng;Bae, Chang-Hwan;Choi, Eun-Hong;Kim, Myoung-Kwon
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.2
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    • pp.1-7
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    • 2019
  • PURPOSE: This study was conducted to investigate effects of shoulder adduction load on rotator cuff muscles, including the infraspinatus, during the external rotation exercise of shoulder. METHODS: This study investigated 16 healthy university students from Daegu University. Before the study started, all participants understood the content of this study. They signed an informed consent form. Five electrodes for surface electromyography (sEMG) were attached to their infraspinatus, middle deltoid, posterior deltoid, upper trapezius and pectoralis major. The participants then underwent the shoulder external rotation exercise with the shoulder adduction at three loads (0 mmHg, 20 mmHg and 40 mmHg) that were controlled using a stabilizer Pressure $Bio-feedback^{TM}$ device. The surface electrodes recorded the electromyographic data during the external rotation exercise of shoulder. RESULTS: The infraspinatus was most activated when the shoulder adduction pressure was 40 mmHg during the external rotation exercise of shoulder. The infraspinatus activation significantly increased when the shoulder adduction pressure intensity increased, while the middle deltoid activation and the posterior deltoid activation significantly decreased (p<.05). CONCLUSION: In conclusion, increases in shoulder adduction load intensity during shoulder external rotation exercises can have a positive effect on the infraspinatus, which consists of rotator cuff muscles, with minimal activity in the middle and posterior deltoid.

Cytosolic domain regulates the calcium sensitivity and surface expression of BEST1 channels in the HEK293 cells

  • Kwon Woo Kim;Junmo Hwang;Dong-Hyun Kim;Hyungju Park;Hyun-Ho Lim
    • BMB Reports
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    • v.56 no.3
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    • pp.172-177
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    • 2023
  • BEST family is a class of Ca2+-activated Cl- channels evolutionary well conserved from bacteria to human. The human BEST paralogs (BEST1-BEST4) share significant amino acid sequence homology in the N-terminal region, which forms the transmembrane helicases and contains the direct calcium-binding site, Ca2+-clasp. But the cytosolic C-terminal region is less conserved in the paralogs. Interestingly, this domain-specific sequence conservation is also found in the BEST1 orthologs. However, the functional role of the C-terminal region in the BEST channels is still poorly understood. Thus, we aimed to understand the functional role of the C-terminal region in the human and mouse BEST1 channels by using electrophysiological recordings. We found that the calcium-dependent activation of BEST1 channels can be modulated by the C-terminal region. The C-terminal deletion hBEST1 reduced the Ca2+-dependent current activation and the hBEST1-mBEST1 chimera showed a significantly reduced calcium sensitivity to hBEST1 in the HEK293 cells. And the C-terminal domain could regulate cellular expression and plasma membrane targeting of BEST1 channels. Our results can provide a basis for understanding the C-terminal roles in the structure-function of BEST family proteins.

Preparation of Adsorbent from Sewage Sludge by Steam Activation and Adsorption Characteristic (하수슬러지의 수증기 활성화법을 이용한 흡착제 제조와 흡착특성)

  • Jung, Dong-Hyun;Chun, Young-Nam
    • Journal of Korean Society of Environmental Engineers
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    • v.29 no.5
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    • pp.515-520
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    • 2007
  • Recently, the treat of sludge is usually progressed by ocean disposal. But it will be totally banned by content of its heavy metal according to London Dumping Convention, gradually. The stable way of treat of sewage sludge should be examined urgently. To solve the problem, recently, there are efficient and environment-oriented method. One of them is to produce absorbent through the activation. This study produces absorbent through steam activation. As basic experiment, optimum activation condition for preparation of good absorbent is researched through study of the fellowing variables : steam flow rate, activated temperature, activation time. As the result of this with standard on iodine adsorptivity, it is chosen, that steam flow rate "30 mL/hr", activation temperature $"500^{\circ}C"$, activation time "60 minutes". At the time, iodine adsorptivity and yield shown that 228.4 mg/g, 77.23%. And also, by using nitrogen adsorption, SEM and EDS are confirmed that pore development, specific surface area, mean pore size, chemical component and content. Pore developed by steam activation is also confirmed that it is micropore.

Analysis of Muscle Activity on Foot Position during a Sit-to-stand activity in the Elderly (노인에서 일어서기 동작 시 발의 위치에 따른 근활성도의 변화)

  • Park, Min-Chull;Lee, Myoung-Hee
    • The Journal of Korean Physical Therapy
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    • v.23 no.1
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    • pp.1-5
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    • 2011
  • Purpose: The purpose of this study was to investigate changes in muscle activation associated with foot position during a sit-to-stand exercise among normally healthy elderly subjects. Methods: Eight subjects (male=3; female=5; mean age=$70.13{\pm}{\pm}2.53$years) were recruited.The activation of six muscles (neck extensor; lumbar extensor; hamstring; rectus femoris; gastrocnemius; tibialis anterior) was measured by surface EMG (TeleMyo 2400T G2, Noraxon Inc., USA) during a sit-to-stand protocol under three different foot positions (ankle dorsiflexion of 0, 15, or 30 degrees). Results: Muscle activation of the neck extensor and hamstring was decreased according to the change in foot position (p<0.05), but activation of the rectus femoris was increased (p<0.05). Muscle activation of the neck extensor was significantly different between 0 and 15 degrees (p<0.05). Muscle activation of the hamstring was significantly different between 0 and 15 degrees and between 0 and 30 degrees (p<0.05). Muscle activation of the rectus femoris was significantly different between 0 and 30 degrees and between 15 and 30 degrees (p<0.05). However, activation of lumbar extensor, gastrocnemius and tibialis anterior muscles did not significantly differ between foot positions. Conclusion: These findings suggest that muscle activation during a sit-to-stand movement differs depending on foot position. We believe that these differences should be considered when educating the elderly regarding proper body movements.

The Effects of Vibration on Shoulder Stabilizer Muscle Activation and Scapular Winging Length of Knee Push-up Plus Exercise in Adults with Scapular Winging (진동이 무릎 푸쉬업플러스 운동 시 어깨뼈 익상이 있는 성인의 어깨안정근 근활성도와 익상 높이에 미치는 영향)

  • Park, Wonyoung;Koo, Hyunmo
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.2
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    • pp.39-47
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    • 2019
  • Purpose : This study was investigated effects of vibration on scapular winging of knee push-up plus exercise. Methods : Twenty-eight female subjects with scapular winging were evaluated after performing knee push-up plus exercise, with or without vibration, three times a week for four weeks. Muscle activation of the serratus anterior and upper trapezius, and the ratio of activation of the upper trapezius to serratus anterior were measured using surface EMG; and scapular winging length was measured by using the caliper. Results : The findings showed that knee push-up plus exercise -with and without- vibration induced a significant increase in muscle activation of serratus anterior (p<.05) and a significant decrease in muscle activation of the upper trapezius (p<.05), the ratio of muscle activation of the upper trapezius to the serratus anterior (p<.05) and scapular winging length (p<.05). There was also a significant difference in muscle activation of the serratus anterior (p<.05) and upper trapezius (p<.05) between control and experimental group at post-test. Conclusion : This study suggests positive clinical effects of knee push-up plus exercise with vibration which enhanced muscle activation of serratus anterior and reduced muscle activation of upper trapezius in person with scapular winging. However, vibration had no effectiveness to improve muscle imbalance between serratus anterior and upper trapezius, and reduce the scapular winging length.

Isotherm for $Ni-O_2$ Adsorption System

  • Kyoung-Hee Ham;Woon-Sun Ahn
    • Bulletin of the Korean Chemical Society
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    • v.11 no.3
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    • pp.231-235
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    • 1990
  • The activation energy of dissociative adsorption of oxygen on polycrystalline nickel surface is calculated from adsorption isotherms obtained using X-ray photoelectron spectroscopy. Negative value of this activation energy (-5.9 kJ/mol) indicates that the adsorption takes place through an undissociated precursor state. An adsorption energy for this precursor state is calculated assuming the precursor state as a moleculary physisorbed state ($E_{ad}$ = -7.9 kJ/mol). Finally, an adsorption isotherm equation is derived as a function of the gas exposure, which agrees with the experimental isotherms reasonably good.

Characteristics of pore structure of steam activated carbon with carbonization temperature (수증기 활성화법으로 제조된 활성탄의 탄화온도에 따른 세공구조 고찰)

  • 이송우;나영수;김도한;최동훈;류동춘;송승구
    • Journal of Environmental Science International
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    • v.9 no.4
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    • pp.345-349
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    • 2000
  • Activated carbons were prepared from Korean coal by steam activation in this study. The variation of pore structure of the activated carbons were investigated according to different carbonization temperatures. Yield, surface area, pore volume and pore structure of this activated carbon were compared with those of activated carbon prepared without carbonization. The investigated carbonization temperature ranged from 700${\circ}C$ to 1,000${\circ}C$. Carbonization was carried out in nitrogen atmosphere for 70 minutes and activation was performed by steam at 950${\circ}C$ for 210 minutes. Surface area and pore volume of the resulting activated carbons increased with carbonization temperature. Also pore volume increased by 20% compared to the activated carbon without carbonization. Especially, in mesopore region, the activated carbon carbonized at 900${\circ}C$ had more pores by 60% than that of activated carbon carbonized at other temperature.

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A Study on the Optimization of Microwave System for the Preparation of Activated Carbon

  • Kim, Dong-Sik;Park, Hwa-Chun;Byeon, Kyeong-Hwa
    • Carbon letters
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    • v.3 no.4
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    • pp.205-209
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    • 2002
  • In the reaction of gas-solid phases, the microwave energy plays a role as a catalyst, because it causes friction between adjacent molecules and enables an unique characteristics of interior heating of the materials. When the dipole gases are adsorbed inside of the pore of carbon materials, the gases are decomposed by the microwave energy and reacted with the carbon atoms. Using this principle, we could make the activated carbon from coconut shell within 20 minute, and this residence time for activation is about 1/16 of rotary kiln. The BET surface area of activated carbon made by microwave is about $1,100m^2/g$ similar to conventional method of rotary kiln. In this study, the power of microwave generator was 400~1000W, and the gas for activation was steam mainly.

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Apoptotic Signaling Pathways: Caspases and Stress-Activated Protein Kinases

  • Cho, Ssang-Goo;Choi, Eui-Ju
    • BMB Reports
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    • v.35 no.1
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    • pp.24-27
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    • 2002
  • Apoptotic cell death is an active process mediated by various signaling pathways, which include the caspase cascade and the stress-activated protein kinase pathways. The caspase cascade is activated by two distinct routes: one from cell surface and the other from mitochondria. Activation of the route from cell surface requires the cellular components that include membrane receptors, adaptor proteins such as TRADD and FADD, and caspase-8, while activation of the other from mitochondria requires Apaf-1, caspase-9, and cytosolic cytochrome c. On the other hand, persistent stimulation of the stress-activated protein kinase pathway is also shown to mediate apoptosis in many cell types. Gene-targeting studies with jnk- or jip-null mice, in particular, strongly suggest that this signaling pathway plays a pivotal role in the cellular machinery for apoptosis.

Electric Conductivities of LaCl3-KCl Binary Melts (용융 LaCl3-KCl 2성분계 혼합염의 전기전도도)

  • Kim, Kiho
    • Journal of the Korean institute of surface engineering
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    • v.47 no.1
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    • pp.48-52
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    • 2014
  • Electric conductivities of $LaCl_3$-KCl binary melts have been measured by the Kohlausch bridge method over the range from their liquidus temperatures to about 1280 K. The electric conductivity increased with the content of KCl for all over the composition range of binary melts. The composition dependence of the electric conductivity and molar conductivity for the binary melt showed a non-linear relation from the additivity line, and the deviation showed a maximum value at about 60 mol.% KCl. The deviation implies the existence of complex ion of $LaCl^{4-}$ in the melt. Activation energy for electric conductivity of the binary melts decreased monotonously with increasing content of KCl.