• 제목/요약/키워드: dynamic membrane

검색결과 299건 처리시간 0.029초

Membrane용 오스테나이트계 304 스테인리스강 판재의 3점 굽힘피로 특성 (Three-Point Bending Fatigue Properties of Austenitic 304 Stainless Steel Sheets for Membrane)

  • 이태호;김성준;김형식;김철만;홍성호
    • 한국가스학회지
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    • 제3권3호
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    • pp.1-8
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    • 1999
  • Membrane용 오스테나이트계 304 스테인리스강 판재의 3점 굽힘피로 특성에 관한 연구를 상온 및 LNG 온도인 $-162^{\circ}C$, 변형량 $0.43{\~}1.70\%$ 범위에서 수행하였다. 저온에서의 굽힘피로 특성이 상온보다 우수한 것으로 나타났고, 이는 변형유기 마르텐사이트 변태에 필요한 구동력이 적어서 보다 많은 양의 마르텐사이트를 함유했기 때문으로 판단된다. 상온 및 저온 모두에서 반복경화 현상이 관찰되었으며, 이러한 반복경화는 상온의 경우 피로주기가 반복됨에 따라 점진적으로 증가되지만 저온의 경우 초기 피로주기에서 급격히 증가된 후 점차로 감소하거나 일정한 값을 나타내었는데 이러한 차이는 저온의 경우 초기에 급격히 변형유기 마르텐사이트가 생성되지만 상온의 경우 변형유기 마르텐사이트 생성에는 일정한 소성변형의 축적이 필요하기 때문으로 생각된다. 기존의 JGA 연구결과와 비교해 볼 때 본 연구에서 사용된 국산소재의 굽힘피로 특성이 우수한 것으로 나타났다.

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In Vivo Measurement of Site-Specific Peritoneal Solute Transport Using a Fiber-Optic-based Fluorescence Photobleaching Technique

  • Lee, Donghee;Kim, Jeong Chul;Shin, Eunkyoung;Ju, Kyung Don;Oh, Kook-Hwan;Kim, Hee Chan;Kang, Eungtaek;Kim, Jung Kyung
    • Journal of the Optical Society of Korea
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    • 제19권3호
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    • pp.228-236
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    • 2015
  • Fluorescence recovery after photobleaching (FRAP) is a well-established method commonly used to measure the diffusion of fluorescent solutes and biomolecules in living cells or tissues. Here a fiber-optic-based FRAP (f-FRAP) system was developed, and validated using macromolecules in water and agarose gels of different concentrations. We applied f-FRAP to measure the site-specific diffusion of fluorescein (NaFluo) in peritoneal membranes (PMs) on the liver, cecum, and kidney of a living rat during peritoneal dialysis. Diffusion of fluorescein in PM varied in a time-dependent manner according to the type of organ ($D_{PM\;on\;Liver}/D_{NaFluo}=0.199{\pm}0.085$, $D_{PM\;on\;Cecum}/D_{NaFluo}=0.292{\pm}0.151$, $D_{PM\;on\;Kidney}/D_{NaFluo}=0.218{\pm}0.110$). The proposed method allows direct quantitative measurement of the three-dimensional diffusion in local PM in vivo, which was previously inaccessible by peritoneal function test methods such as peritoneal equilibration test (PET) and standardized PM assessment (SPA). f-FRAP is promising for local and dynamic assessments of peritoneal pathophysiology and the mass transport properties of PMs, presumed to be affected by variation of tissue structures over different organs and functional changes of the PM with years of peritoneal dialysis.

Research on the development law of karst fissures and groundwater characteristic in Xintian County

  • Xin, Zhou;Tengfei, Yao;Can, Wang;Jian, Ou;Pengfei, Zheng;Kaihong, Chen;Xiting, Long
    • Membrane and Water Treatment
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    • 제13권6호
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    • pp.303-312
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    • 2022
  • The natural hydrology and geological conditions of Xintian County was investigated, the development law of regional karst fissures was studied, the groundwater was collected and tested through a large-scale collection of groundwater to obtain the change law of chemical characteristics and water quality characteristics of groundwater, and the water quality evaluation was carried out for the regional karst groundwater in this paper. The results show that, the whole area is dominated by carbonate rock distribution areas, and the distribution of water systems is relatively developed. The strata are distributed from the Lower Paleozoic Cambrian to the Cenozoic Quaternary, and contain multiple first-order folds. The regional karst dynamic action is strong, and many tunnels or caves of different scales were shown, which are conducive to the enrichment of groundwater. Karst groundwater is neutral and alkaline water, the water is clear and transparent with good taste, and meets the national drinking water hygiene standards. The content of toxic trace elements and fluoride in the water source is generally lower than the limit value specified by the national standard and the accumulated toxic heavy metals is never found. The overall water quality is of good quality and suitable for the development and utilization of various purposes.

개신교 '자유케 됨'의 영성에 기초한 기독교 영성교육 모형: '자유케 됨'의 실천 (The Practice of 'Liberated-ness': An Education Model for Protestant Spiritual Practice)

  • 황인혜
    • 기독교교육논총
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    • 제68권
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    • pp.375-415
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    • 2021
  • 기독교 영성교육에 대한 관심은 날이 갈수록 증가되는 추세에 있지만, 한국교회 현장의 영성교육은 개신교 전통에 따른 선명한 교육목적의 제시가 없는 가운데 교육내용과 방법이 파편화되어 있는 실정이다. 그러므로 엄밀한 학문적 방법에 의거하여 개신교 영성교육의 목적을 정립하고 그것에 맞는 교육의 내용과 방법을 찾아내는 연구가 필요하다. 이 필요성에 따라 수행된 본 연구는 개신교 영성의 핵심정신을 찾아 교육목적으로 삼고 그 목적을 구현할 수 있는 개신교 교유의 영성교육 내용을 찾아 그것을 오랜 역사를 가진 그리스도교 영성수련들과 유기적으로 통합한 하나의 창의적 영성교육 모형을 제안하는 것을 목적으로 한다. 먼저 교육목적의 설정을 위해서 개신교 대표지도자 루터(Luther), 칼빈(Calvin), 그리고 웨슬리(Wesley)의 '믿음의 삶'에 대한 가르침을 고찰하였다. 그 가르침 안에서 '개신교 영성'의 핵심정신으로서 '자유케 됨'(liberated-ness)의 정신을 발견하여 교육목적으로 삼고, 로마가톨릭교회의 '은혜' 개념과는 다른 개신교 특유의 '은혜의 방편' 전통을 발견해 내어 '자유케 됨'을 구현하는 교육내용으로 삼았다. 그리고 '자유케 됨'이 이루어지는 기전을 다음의 세 개의 창의적 개념으로 설명한다. 신자의 '자유케 됨'은 하나님에게서 나오는 '자유케 하는 의지'(liberating will)로 시작되며, 신자는 '자기를 드리는 의지'(self-giving will)로 이에 응답하게 되는데, 이 두 의지가 만나는 접촉점이 '믿음의 생명막'(the living membrane of faith)이다. 이 기전을 기초로 삼아 구성된 '자유케 됨의 실천' 영성교육 모형의 교육목적은 학습자가 삶 가운데 하나님과의 인격적 '만남'을 가지며 점점 더 '자유케 됨'을 누리는 가운데 더 충성스럽게 이웃을 자유케 하는 사람이 되어가는 것이다. 학습자와 교사의 관계는 쉐릴(Sherrill)의 인격적 '만남'의 관계이며 김현숙의 '공유적 권위'를 갖는 관계이다. 교육내용은 쉐릴의 '만남'의 성경묵상과 다익스트라(Dykstra)의 '실천들', 그리고 개신교 '은혜의 방편'의 다섯 영역과 연계된 그리스도교의 영성수련 다섯 가지를 채택하여 그것을 개신교의 '자유케 됨'의 원리로 변형한 것이다. 이 영성수련들의 새로운 명칭은 '만남의 렉시오 디비나,' '주님향함기도,' '서로-영적방향잡기,' '자유마중섬김,' 그리고 '자유성찰기도'이다. 교수-학습과정은 다익스트라가 학습자 중심의 실천을 돕는 데 사용한 코칭과 멘토링의 과정이다. 교육환경은 무어(Moore)의 '성례전적 공동체'를 지향하는 인적 환경에 중점을 두며, 평가는 학습자 스스로 평가하는 것을 기본으로 한다. 본 교육모형은 그리스도교 역사 안의 주요 영성수련 내용들을 명시적으로 개신교의 '자유케 됨'의 영성으로 변형하여 교육하는 길을 제시함으로써 초대교회 때부터 이어지는 그리스도교 영성수련의 맥을 개신교 교회에서 창조적으로 계승하여 나갈 수 있게 해 준다는 의의를 갖는다.

쥐 척수후각세포의 유해자극 반응에 대한 칼슘이온통로 차단제의 억제작용 (Calcium Channel Blockers Suppress the Responses of Rat Dorsal Horn Cell to Nociceptive Input)

  • 강석한;김기순;신홍기
    • The Korean Journal of Physiology and Pharmacology
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    • 제1권6호
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    • pp.625-637
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    • 1997
  • Calcium ions are implicated in a variety of physiological functions, including enzyme activity, membrane excitability, neurotransmitter release, and synaptic transmission, etc. Calcium antagonists have been known to be effective for the treatment of exertional angina and essential hypertension. Selective and nonselective voltage-dependent calcium channel blockers also have inhibitory action on the acute and tonic pain behaviors resulting from thermal stimulation, subcutaneous formalin injection and nerve injury. This study was undertaken to investigate the effects of iontophoretically applied $Ca^{++}$ and its antagonists on the responses of WDR (wide dynamic range) cells to sensory inputs. The responses of WDR cells to graded electrical stimulation of the afferent nerve and also to thermal stimulation of the receptive field were recorded before and after iontophoretical application of $Ca^{++}$, EGTA, $Mn^{++}$, verapamil, ${\omega}-conotoxin$ GVIA, ${\omega}-conotoxin$ MVIIC and ${\omega}-agatoxin$ IVA. Also studied were the effects of a few calcium antagonists on the C-fiber responses of WDR cells sensitized by subcutaneous injection of mustard oil (10%). Calcium ions and calcium channel antagonists ($Mn^{++}$, verapamil, ${\omega}-conotoxin$ GVIA & ${\omega}-agatoxin$ IVA) current-dependently suppressed the C-fiber responses of WDR cells without any significant effects on the A-fiber responses. But ${\omega}-conotoxin$ MVIIC did not have any inhibitory actions on the responses of WDR cell to A-fiber, C-fiber and thermal stimulation. Iontophoretically applied EGTA augmented the WDR cell responses to C-fiber and thermal stimulations while spinal application of EGTA for about $20{\sim}30\;min$ strongly inhibited the C-fiber responses. The augmenting and the inhibitory actions of EGTA were blocked by calcium ions. The WDR cell responses to thermal stimulation of the receptive field were reduced by iontophoretical application of $Ca^{++}$, verapamil, ${\omega}-agatoxin$ IVA, and ${\omega}-conotoxin$ GVIA but not by ${\omega}-conotoxin$ MVIIC. The responses of WDR cells to C-fiber stimulation were augmented after subcutaneous injection of mustard oil (10%, 0.15 ml) into the receptive field and these sensitized C-fiber responses were strongly suppressed by iontophoretically applied $Ca^{++}$, verapamil, ${\omega}-conotoxin$ GVIA and ${\omega}-agatoxin$ IVA. These experimental findings suggest that in the rat spinal cord, L-, N-, and P-type, but not Q-type, voltage-sensitive calcium channels are implicated in the calcium antagonist-induced inhibition of the normal and the sensitized responses of WDR cells to C-fiber and thermal stimulation, and that the suppressive effect of calcium and augmenting action of EGTA on WDR cell responses are due to changes in excitability of the cell.

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성대구증 및 성대 반흔 환자에서 주사후두성형술의 효과 (Injection Laryngoplasty for The Treatment of Vocal Fold Scar, and Sulcus)

  • 우주현;백민관;김동영;박형민;안상희;문광하;차흥억
    • 대한후두음성언어의학회지
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    • 제27권1호
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    • pp.25-29
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    • 2016
  • Background and Objectives : The clinical reports for the treatment of vocal fold scar and sulcus vocalis are limited, also there is no best one for the treatment of them. This study is to evaluate the effect of Injection laryngoplasty (IL) for the treatment of vocal fold scar and sulcus vocalis. Materials and Methods : from January 2013 to May 2015, the Nineteen patients who were diagnosed as vocal fold scar, sulcus and atrophy, and underwent IL, were engaged in this study. Clinical information and voice parameters were analyzed by retrospective chart review. Pre and post voice parameters were compared. Results : Subgroups of diagnosis were classified into sulcus vocalis for 12 patients, vocal fold scar for 5, and atrophy for 2. IL was performed under local anesthesia through cricothyroid membrane except one patient. Atesense$^{(R)}$, Radiessess$^{(R)}$, and Rofilan$^{(R)}$ were used as injected materials in 9, 9, and 1 patients respectively. Maximal phonation time (p=0.0124), dynamic range (p=0.0028), pitch range (p=0.0141), voice handicap index (p=0.028), glottal closure (p=0.0229), and mucosal wave (p=0.0132) had significant improvement for post-IL voice assessment than Pre-IL. While GRBAS, Mean flow rate, Jitter, Shimmer, Harmony to Noise ratio didn't have improvement. Conclusion : IL is a feasible option for the treatment of glottis incompetence with normally mobile vocal folds such as sulcus vocalis and vocal fold scar.

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진단용 초음파에 의해 가진된 초음파 조영제에서 방사하는 하모닉 성분의 크기: 이론적 고찰 (Magnitudes of the Harmonic Components Emitted from Utrasonic Contrast Agents in Response to a Diagnostic Utrasound: Theoretical Consideration)

  • 강관석;유지철;팽동국;임성민;최민주
    • 한국음향학회지
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    • 제24권2호
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    • pp.78-86
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    • 2005
  • 진단용 초음파에 의해 가진된 초음파 조영제에서 방사하는 하모닉 성분의 크기를 이론적으로 고찰하였다. 본 연구에서는 2 MHz 진단용 초음파 펄스에 의한 초음파 조영제의 비선형 동적 반응을 Gilmore Model을 이용하여 수치 해석하였다. 초음파 조영제의 탄성 효과는 무시하였다. 초음파 조영제 반경의 크기 (1-9 $\mu$m)와 초음파의 MI 값 (0.125-8)을 변화시키면서 발생된 서브, 울트라. 2차 하모닉 성분의 파워를 기본 주파수 성분과 비교하였다. 시뮬레이션 결과, 초음파 조영제가 공진 반경 (2 $\mu$m) 보다 클 경우, 초음파 조영제에서 방출하는 서브 하모닉의 파워가 기본 주파수 것 보다 압도적으로 크게 나타났다. 특히 하모닉 영상에서 사용하는 2차 하모닉의 파워는 서브 및 울트라 하모닉 성분 보다 낮은 값을 가지는 것으로 예측되었다. 본 연구 결과는 초음파 조영제를 이용하여 하모닉 영상을 구현할 경우, 서브 및 울트라 하모닉 성분이 2차 하모닉 성분 보다 우수한 영상 변수가 될 수 있음을 시사한다.

Mitochondrial calcium uniporter inhibition attenuates mouse bone marrow-derived mast cell degranulation induced by beta-1,3-glucan

  • Dang, Van Cuong;Kim, Hyoung Kyu;Marquez, Jubert;Kim, Nari;Ko, Kyung Soo;Rhee, Byoung Doo;Han, Jin
    • The Korean Journal of Physiology and Pharmacology
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    • 제20권2호
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    • pp.213-220
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    • 2016
  • Mast cells are primary mediators of allergic inflammation. Beta-1,3-glucan (BG) protects against infection and shock by activating immune cells. Activation of the BG receptor induces an increase in intracellular $Ca^{2+}$, which may induce exocytosis. However, little is known about the precise mechanisms underlying BG activation of immune cells and the possible role of mitochondria in this process. The present study examined whether BG induced mast cell degranulation, and evaluated the role of calcium transients during mast cell activation. Our investigation focused on the role of the mitochondrial calcium uniporter (MCU) in BG-induced degranulation. Black mouse (C57) bone marrow-derived mast cells were stimulated with $0.5{\mu}g/ml$ BG, $100{\mu}g/ml$ peptidoglycan (PGN), or $10{\mu}M$ A23187 (calcium ionophore), and dynamic changes in cytosolic and mitochondrial calcium and membrane potential were monitored. BG-induced mast cell degranulation occurred in a time-dependent manner, and was significantly reduced under calcium-free conditions. Ruthenium red, a mitochondrial $Ca^{2+}$ uniporter blocker, significantly reduced mast cell degranulation induced by BG, PGN, and A23187. These results suggest that the mitochondrial $Ca^{2+}$ uniporter has an important regulatory role in BG-induced mast cell degranulation.

Dual Component Analysis for In Vivo T2* Decay of Hyperpolarized 13C Metabolites

  • Joe, Eunhae;Lee, Joonsung;Lee, Hansol;Yang, Seungwook;Choi, Young-Suk;Wang, Eunkyung;Song, Ho-Taek;Kim, Dong-Hyun
    • Investigative Magnetic Resonance Imaging
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    • 제21권1호
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    • pp.1-8
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    • 2017
  • Purpose: To investigate the exchange and redistribution of hyperpolarized $^{13}C$ metabolites between different pools by temporally analyzing the relative fraction of dual $T_2{^*}$ components of hyperpolarized $^{13}C$ metabolites. Materials and Methods: A dual exponential decay analysis of $T_2{^*}$ is performed for [1-$^{13}C$] pyruvate and [1-$^{13}C$] lactate using nonspatially resolved dynamic $^{13}C$ MR spectroscopy from mice brains with tumors (n = 3) and without (n = 4) tumors. The values of shorter and longer $T_2{^*}$ components are explored when fitted from averaged spectrum and temporal variations of their fractions. Results: The $T_2{^*}$ values were not significantly different between the tumor and control groups, but the fraction of longer $T_2{^*}$ [1-$^{13}C$] lactate components was more than 10% in the tumor group over that of the controls (P < 0.1). The fraction of shorter $T_2{^*}$ components of [1-$^{13}C$] pyruvate showed an increasing tendency while that of the [1-$^{13}C$] lactate was decreasing over time. The slopes of the changing fraction were steeper for the tumor group than the controls, especially for lactate (P < 0.01). In both pyruvate and lactate, the fraction of the shorter $T_2{^*}$ component was always greater than the longer $T_2{^*}$ component over time. Conclusion: The exchange and redistribution of pyruvate and lactate between different pools was investigated by dual component analysis of the free induction decay signal from hyperpolarized $^{13}C$ experiments. Tumor and control groups showed differences in their fractions rather than the values of longer and shorter $T_2{^*}$ components. Fraction changing dynamics may provide an aspect for extravasation and membrane transport of pyruvate and lactate, and will be useful to determine the appropriate time window for acquisition of hyperpolarized $^{13}C$ images.

Knockdown of Archvillin by siRNA Inhibits Myofibril Assembly in Cultured Skeletal Myoblast

  • Lee, Yeong-Mi;Kim, Hyun-Suk;Choi, Jun-Hyuk;Choi, Jae-Kyoung;Joo, Young-Mi;Ahn, Seung-Ju;Min, Byung-In;Kim, Chong-Rak
    • 대한의생명과학회지
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    • 제13권4호
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    • pp.251-261
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    • 2007
  • A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

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