• Title/Summary/Keyword: Action potentials

검색결과 204건 처리시간 0.033초

이산화지르코늄과 상호작용하는 금 표면 위의 글루타싸이온층 표면 물성 (Surface Properties of Glutathione Layer Formed on Gold Surfaces Interacting with ZrO2)

  • 박진원
    • Korean Chemical Engineering Research
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    • 제52권4호
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    • pp.538-543
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    • 2014
  • 이산화지르코늄 표면에 흡착되는 금 입자의 분포 또는 그 반대 경우의 분포에 영향을 끼칠 수도 있는 정전기적 상호작용과 금 입자를 코팅한 Glutathione층의 표면물성을 규명하였다. 이를 위하여, 원자힘현미경(AFM)으로 Glutathione 층 표면과 이산화지르코늄표면 사이의 표면힘을 염 농도와 pH 값에 따라 측정하였다. 측정된 힘은 Derjaguin-Landau-Verwey-Overbeek(DLVO) 이론으로 해석되어 표면의 전하밀도와 포텐셜들이 정량적으로 산출되었다. 이 특성들이 염 농도와 pH에 대하여 나타내는 의존성을 질량보존의 법칙으로 기술하였다. pH 8 조건에서 실험으로 산출된 표면 특성의 염 농도 의존성은 이론적으로 예측했던 결과와 일치하는 것으로 관찰되었다. Glutathione 층의 표면이 이산화지르코늄 표면보다 높은 전하밀도와 포텐셜을 갖는 것이 발견되었는데, 이는 Glutathione 층의 이온화-기능-그룹에 기인한 것으로 생각된다.

Bone Marrow-derived Side Population Cells are Capable of Functional Cardiomyogenic Differentiation

  • Yoon, Jihyun;Choi, Seung-Cheol;Park, Chi-Yeon;Choi, Ji-Hyun;Kim, Yang-In;Shim, Wan-Joo;Lim, Do-Sun
    • Molecules and Cells
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    • 제25권2호
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    • pp.216-223
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    • 2008
  • It has been reported that bone marrow (BM)-side population (SP) cells, with hematopoietic stem cell activity, can transdifferentiate into cardiomyocytes and contribute to myocardial repair. However, this has been questioned by recent studies showing that hematopoietic stem cells (HSCs) adopt a hematopoietic cell lineage in the ischemic myocardium. The present study was designed to investigate whether BM-SP cells can in fact transdifferentiate into functional cardiomyocytes. Phenotypically, BM-SP cells were $19.59%{\pm}9.00\;CD14^+$, $8.22%{\pm}2.72\;CD34^+$, $92.93%{\pm}2.68\;CD44^+$, $91.86%{\pm}4.07\;CD45^+$, $28.48%{\pm}2.24\;c-kit^+$, $71.09%{\pm}3.67\;Sca-1^+$. Expression of endothelial cell markers (CD31, Flk-1, Tie-2 and VEGF-A) was higher in BM-SP cells than whole BM cells. After five days of co-culture with neonatal cardiomyocytes, $7.2%{\pm}1.2$ of the BM-SP cells expressed sarcomeric ${\alpha}$-actinin as measured by flow cytometry. Moreover, BM-SP cells co-cultured on neonatal cardiomyocytes fixed to inhibit cell fusion also expressed sarcomeric ${\alpha}$-actinin. The co-cultured BM-SP cells showed neonatal cardiomyocyte-like action potentials of relatively long duration and shallow resting membrane potential. They also generated calcium transients with amplitude and duration similar to those of neonatal cardiomyocytes. These results show that BM-SP cells are capable of functional cardiomyogenic differentiation when co-cultured with neonatal cardiomyocytes.

교근에서 보툴리눔 독소 주사점의 표지화 (Surface Mapping of Masseter for Botulinum Toxin Injection)

  • 김준형;이민재;김현지;손대구;한기환;이소영;임정근;최인장
    • Archives of Plastic Surgery
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    • 제32권3호
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    • pp.311-313
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    • 2005
  • Generally, many Asian women tend to dislike the square jaw, as they believe it makes the face look wider, giving a stubborn and strong impression. Contouring of the mandible is therefore a relatively common aesthetic procedure among Asians. These days, the use of botulinum toxin for contouring of the lower face offer simple alternative to surgery. Motor point, which is the site over a muscle where its contraction may be elicited by a minimal intensity short duration electrical stimulus, is the optimal injection point of botulinum toxin. Study was undertaken to identify the location of motor point of the masseter muscle and the skin surface landmark. First, the thickest point of the masseter muscle was inspected through palpation and inspection by 3 different individual plastic surgeons and then compound muscle action potentials(CMAPs) of masseter muscle in 15 health volunteers were recorded using EMG. For the localization of the measured points, line between lateral canthus to the mandibular angle was used. Location of motor points were mapped to skin surface from lateral canthus in a percentage of the distance along the landmark line and in distance in millimeters. The clinical injection point was located at 71.69 percentile and 7.3 mm of the landmark line. The motor point test was located at 72.54 percentile and 7.1 mm of the landmark line. The depth of motor point was 16mm. There was no statistically significant difference between the clinical injection point and the motor point. We conclude that surface mapping of motor point of the masseter muscle would increase accessibility and accuracy in botulinum toxin injection for contouring of the lower face.

곡기생(槲寄生)의 항염증 효능 및 암세포 이주저해에 미치는 영향 (The Effects of Gokgisaeng on Anti-inflammation and Rat C6 Glioma Cell Migration)

  • 김현영;장수영;정지천;신현철
    • 대한한방내과학회지
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    • 제34권1호
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    • pp.31-45
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    • 2013
  • Objectives : Gokgisaeng (Korean mistletoe) is used for the treatment of inflammatory and cancer diseases in traditional Korean medicine and its major component lectins have been reported to induce nitric oxide (NO) in RAW 264.7 macrophages, and also induce apoptosis of various types of cancer cells, although its modulatory effects on cancer cell migration and macrophage activation is poorly understood. The aim of this study is to clarify molecular mechanisms of action responsible for the anti-inflammatory and antitumor migration potentials of Korean mistletoe extract (KME). Methods : We investigated the anti-inflammatory activity of KME on NO production and inducible nitric oxide synthase (iNOS) expression by lipopolysaccharide (LPS) in both RAW 264.7 macrophages and rat C6 glioma cells, and also evaluated inhibitory efficacy on glioma cell growth and migration. For assessment, XTT assay, nitrite assay, RT-PCR, scratch-wound and Boyden chamber assay, and western blot analysis were performed. Results : Previously reported, unlike the efficacy of Gokgisaeng lectin, KME inhibited NO production and iNOS expression, and suppressed pro-inflammatory mediators including IL-$1{\beta}$, IL-6, COX-2, iNOS in LPS-stimulated RAW 264.7 cells. Furthermore, KME suppressed tumor cell growth and migration, and it also inhibited LPS-induced NO release and iNOS activation by down-regulating expression of protein kinase C (PKC) and phosphorylation of ERK in C6 glioma cells. Conclusions : Our research findings provide evidence that KME can play a significant role in blocking pro-inflammatory reaction and malignant progression of tumors through the suppression of NO/iNOS by down-regulating of inflammatory signaling pathways, PKC/ERK.

인체 간암세포에서 비기환(肥氣丸), 대칠기탕(大七氣湯) 및 목향빈랑환(木香檳榔丸) 열수 추출물의 항암 활성 비교 (Comparison of Anti-cancer Potentials of Water Extracts of Bigihwan, Daechilgithang and Mokwhyangbinranghwan in Human Hepatocellular Carcinoma Cells)

  • 김민영;이혜숙;홍수현;박철;최영현
    • 대한한의학방제학회지
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    • 제28권1호
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    • pp.15-27
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    • 2020
  • Objectives : We selected three herb-combined remedies, Bigihwan (BGH), Daechilgitang (DCGT) and Mokwhyangbinranghwan (MHBRH), through Donguibogam text-mining analysis, and evaluated their anti-cancer effects on human hepatocellular carcinoma Hep3B cells. Methods : Cytotoxicity was assessed by an MTT assay. Apoptosis rate, autophagy and ROS level were detected by flow cytometry. The autophagy was also observed by Cyto-ID staining fluorescence microscopy. The expression of autophagy, mitophagy and pexophagy regulatory proteins was detected by Western blot analysis. Results : BGH showed the strongest effect among the three prescriptions in inhibiting Hep3B cell viability, which was associated with the induction of apoptosis and autophagy. Autophagy blockers improved cell viability and reduced apoptosis after BGH and DCGT treatments, indicating that autophagy by these prescriptions enhanced Hep3B cells against their cytotoxicity. However, MHBRH enhanced the reduction of cell viability and apoptosis by autophagy blockers. Induction of autophagy by BGH treatment was associated with mitophagy due to mitochondrial dysfunction than DCGT and MHBRH-treated cells. In addition, induction of apoptosis by BGH treatment was ROS-dependent and showed the possibility of pexophagy involvement. Conclusion : Although further studies need to be conducted to study the efficacy and mechanism of accurate anticancer activity, the present results will serve as important sources of understanding the mechanism of action of herbal remedies prescribed for liver disease as documented in Donguibogam.

생분해성 생리활성물질 5-aminolevulinic acid의 제초 및 살충활성 (Herbicidal and Insecticidal Potentials of 5-Aminolevulinic acid, a Biodegradable Substance)

  • 천상욱
    • 농약과학회지
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    • 제11권1호
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    • pp.52-58
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    • 2007
  • 5-Aminolevulinic acid (ALA)는 protoporphyrinogen IX oxidase(Protox IX)의 작용기작에 의해 tetrapyrrole 의존형 광활성 제초제 또는 살충제로서 제안되어 왔다. 본 연구는 생분해성 생물농약 물질로서 ALA에 대한 식물과 해충의 생육반응을 검토하기 위해 수행되었다. 수도적 조건에서 ALA는 벼와 피 두 초종에 대해 독성을 보였으며 벼보다는 피의 초장과 지상부 생체중을 더 억제하였다. 밭 조건에서 두과작물 콩과 화본과 잡초 바랭이에 5 mM ALA를 처리한 결과 바랭이가 더 민감한 생육반응을 보였다. ALA 10 mM(10배액)로 파밤나방에 대한 살충효과는 살포법으로 처리한 결과 단제 및 합성 살충제 lufenuron과의 조합처리에서 다소 높게 나타났다. leaf disk법으로 응애에 대한 살비효과를 검정한 결과 10 mM ALA 처리 후 72시간에 가장 높게 나타났다. 이상의 결과로 볼 때 ALA는 비록 그 활성이 기존의 합성농약보다 낮을지라도 농업유해생물에 대해 잠재적인 제초 및 살충활성을 갖고 있는 것으로 나타났다.

Sodium butyrate에 의한 E-cadherin의 발현증가와 세포간 상호작용의 변화 (Sodium Butyrate Alters Cell-Cell Interactions through Up-Regulation of E-Cadherin in Human Hepatocellular Carcinoma Cells)

  • 권현진;장경립
    • 생명과학회지
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    • 제19권6호
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    • pp.705-710
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    • 2009
  • Sodium butyrate (NaBt)는 장에서 탄수화물대사로부터 생겨나는 짧은 천연지방산 사슬로 다양한 인간 암세포들 에게서 강력한 항암효능을 나타냄이 보고된 바 있지만 자세한 기전은 아직 알려져 있지 않다. 이 논문에서 우리는 NaBt가 주요 세포부착분자이면서 종양억제인자의 일종인 E-cadherin의 발현을 세포-특이적으로 촉진하는 기전을 연구하였다. 또한 NaBt는 E-eadherin의 발현을 촉진하는 것으로 알려진 p21의 발현도 증가시켰지만, NaBt에 의하여 증가한 p21은 E-cadherin의 활성화와 관련이 없음이 밝혀졌다. 그 대신에 NaBt는 CCAAT-box를 통한 E-cadherin 유전자의 프로모터 활성을 증가시킴으로써 E-cadherin의 발현을 전사수준에서 촉진하는 것 같다. 이렇게 NaBt에 의하여 증가된 E-cadherin은 주로 세포간 접촉면에 위치하면서 Hep3B 세포를 더 분화된 형태로 유도하여 NaBt의 항암활성이 나타나는 것 같다.

신경전도검사의 정상치에 관한 연구 (Study on Normal Nerve Conduction Parameters)

  • 한송이;김대성;박규현
    • Annals of Clinical Neurophysiology
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    • 제1권2호
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    • pp.118-125
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    • 1999
  • Background and Aims : Nerve conduction study is invaluable in clinical neurology, especially for assessing peripheral neuropathies. Abnormal nerve conduction studies may result not only from peripheral nerve dysfunction itself, but also from other various mechanical, technical, and physiological factors such as age, sex, height and temperature. So we conducted this study to establish the our own normal values. Methods : In this study, from March. 1997 to July. 1998, 40 Korean adults among person came to Health Promotion Center over the age of 20 without any suspicion of neurological deficits were analysed to determine the effect of compound effects of several physiological factors. Results : The nerve conduction velocities of the upper extremity and proximal segments were faster than those of the lower extremity and distal segments. Physiological factors such as age, height and temperature affect the results of nerve conduction studies in multiple regression analysis. The sex difference is recognized over peroneal motor nerve. There are no sex differences in amplitude transformed into normal distribution. The significant physiological factor affecting the amplitude of nerve conduction is age, whereas height and temperature play no role. Conclusions : In multiple regression analysis, height is widespread variable for the nerve conduction velocities and temperature is important variable for lower extremities. The parametric statistical analysis cannot be applied to the amplitude of the compound muscle or nerve action potentials because of marked left shift in distribution. Sqareroot transformation of the CMAP and CNAP may be useful in normalizing the distribution. The most significant physiological factor affection the amplitude is age. Sex differences are not seen in nerve conduction study.

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금 표면 위의 메르캡토언데카노익산층 표면과 이산화지르코늄 표면 사이의 정전기적 상호작용 (Electrostatic Interaction between Mercaptoundecanoic-acid Layers on Gold and ZrO2 Surfaces)

  • 박진원
    • 공업화학
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    • 제25권6호
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    • pp.607-612
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    • 2014
  • 이산화지르코늄 표면에 흡착되는 금 입자의 분포 또는 그 반대 경우의 분포에 영향을 끼칠 수도 있는 정전기적 상호작용과 금 입자를 코팅한 mercaptoundecanoic acid층의 표면물성을 규명하였다. 이를 위하여, 원자힘현미경(AFM)으로 mercaptoundecanoic acid층 표면과 이산화지르코늄표면 사이의 표면힘을 염 농도와 pH 값에 따라 측정하였다. 측정된 힘은 Derjaguin-Landau-Verwey-overbeek (DLVO) 이론에 의해 표면의 정량적인 전하밀도와 포텐셜 값들로 전환되었다. 이 값들이 염 농도와 pH에 따라 달라지는 특성을 질량보존의 법칙으로 기술하였으며, 산출된 표면 특성의 염 농도 의존성은 이론적으로 예측했던 결과와 일치하는 것으로 확인되었다. Mercaptoundecanoic acid층의 표면이 이산화지르코늄 표면보다 높은 전하밀도와 포텐셜을 갖는 것이 발견되었는데, 이는 mercaptoundecanoic acid층의 이온화 기능기에 기인한 것으로 생각된다.

청각 스트레스가 3차원 시자극 유발전위에 미치는 영향 분석 (Audio Stress Effect on Visual ERP Stimulated by 3-dimensional Environment)

  • 박찬희;홍철운;김남균
    • 대한의용생체공학회:의공학회지
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    • 제23권4호
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    • pp.301-308
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    • 2002
  • 연구는 인간에게 3차원 공간상에서 시청각 통합 환경을 만든 후 정신적 스트레스가 시각 자극을 통해 ERPs에 어떠한 영향을 미치는지를 정량적으로 분석하기 위하여 수행되었다. 이를 위하여, 정상 상태와 정신적 스트레스를 제시 상태를 구분하여 ERPs를 측정하였다. 실험은 정상상태의 남녀 10명의 피험자를 대상으로 하였고. 생체 신호는 Fpl, Fz, Cz. Pz, O1, O2의 영역에서 전자기적 영향을 받지 않는 차폐 공간에서 측정하였다. 그 결과 P300의 진폭은 스트레스를 제시한 경우에 좀더 커지고, 이때의 잠재기는 길어지는 결과를 얻었다 본 연구에서는 인간의 지각, 인지. 행동의 과정을 담당하는 뇌의 활동을 전위 변동으로 기록하여 정신적 스트레스의 영향을 측정하였다. 이러한 기초적 연구 검토를 통하여 인간의 제반 과정에 관한 뇌 기능의 이상을 평가 할 수 있을 것이라 기대된다.