• 제목/요약/키워드: Release mechanism

검색결과 903건 처리시간 0.024초

스키에 의한 슬관절 인대 손상 (Ligament Injuries of Knee in the Recreational Skiers)

  • 이동철;고진혁;김동한
    • 대한정형외과스포츠의학회지
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    • 제2권1호
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    • pp.37-43
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    • 2003
  • 목적: 스키손상에서슬관절인대손상의형태와영향을줄수있는인자를분석하고, 수상전후의슬관절기능평가및스포츠활동도변화를알고자하였다. 대상및방법: 슬관절인대손상환자30명을대상으로설문및이학적검사, X선및MRI 촬영을통한평가를하였고, 기능평가는Lysholm Knee Scoring Scale, 스포츠활동도는Tegner activity score로평가하였다. 결과: 내측측부인대손상을동반한전방십자인대손상이11명으로가장많았고, 내측측부인대손상이9명으로그다음이었다. 수상기전은유령발현상(phantom foot phenomenon)과외전-외회전기전이각각13례와12례로83 $\%$를차지했다. 최종추시에서평균Lysholm score는93.4점으로매우양호하였으며, 활동도는수상전Tegner activity score 6.1점에서수상후4.2점으로감소되었다. 기능과활동도평가에서내측측부인대단독손상군이경과가가장양호하였으며, 내측측부인대손상을동반한전방십자인대손상군이경과가불량하였다. 스키손상에영향을미칠수있는요인으로는스키를지속적으로2시간이상탄경우, 바인딩이풀리지않는경우, 적절한스키강습프로그램을받지않은경우였다. 결론: 환자들의수상후Lysholm score는매우양호했지만, 수상후스포츠활동도에서는수상전과뚜렷한차이를보여적극적이고체계적인스포츠복귀프로그램이필요함을알수있었다.

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청소년기 야구 투수의 상완골 회전력: 소아 야구 견 및 상완골 후염의 발달에 미치는 영향 (Humeral Torque in Youth Baseball Pitchers: Implications for the Development of Little League Shoulder and Humeral Retroversion)

  • 김영규
    • 대한정형외과스포츠의학회지
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    • 제2권1호
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    • pp.62-70
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    • 2003
  • 목적: 청소년기야구투수의견관절의운동학및동력학을통해소아야구견및상완골후염의발달에대한역학적측면을분석하고자하였다. 대상및방법: 모의 게임을통해 14명의청소년기야구투수에서관절운동학과상완골에작용하는총힘및회전력을계산하였다.결과: 상완골에작용하는주된힘은평균378$\pm$81N의장력으로공이손을 떠난 직후에정점을이루었다. 상완골에 작용하는 주된 회전력은 상완골의 장축에 대한 외 회전력으로 투구 동작의 약73$\%$ 시기에 정점을 나타냈으며 정점의 평균 회전력은 35.3$\pm$ 6.7Nm이었다. 이러한회전력은성인의상완골골절을발생시킬수있는회전력의약66$\%$이다. 결론: 상완골회전력은투구하는손의상완골후염의증가를발달시키는방향이었다. 따라서후기거상기동안의큰회전력으로부터발생되는 전단응력은상대적으로약한근위상완성장판에변형을초래할수있다. 또한투구중상완골에발생되어진외회전력은투구동작중성장판에작용하는회전응력이소아야구견을일으키는기전이될수있다는가설을뒷받침해준다.

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Effect of the Inhibition of PLA2 on Oxidative Lung Injury Induced by $Interleukin-1{\alpha}$

  • Lee, Young-Man;Cho, Hyun-Gug;Park, Yoon-Yub;Kim, Jong-Ki;Lee, Yoon-Jeong;Park, Won-Hark;Kim, Teo-An
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권5호
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    • pp.617-628
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    • 1998
  • In order to understand the pathogenetic mechanism of adult respiratory distress syndrome (ARDS), the role of phospholipase A2 (PLA2) in association with oxidative stress was investigated in rats. $Interleukin-1{\alpha}\;(IL-1,\;50\;{\mu}g/rat)$ was used to induce acute lung injury by neutrophilic respiratory burst. Five hours after IL-1 insufflation into trachea, microvascular integrity was disrupted, and protein leakage into the alveolar lumen was followed. An infiltration of neutrophils was clearly observed after IL-1 treatment. It was the origin of the generation of oxygen radicals causing oxidative stress in the lung. IL-1 increased tumor necrosis factor (TNF) and cytokine-induced neutrophil chemoattractant (CINC) in the bronchoalveolar lavage fluid, but mepacrine, a PLA2 inhibitor, did not change the levels of these cytokines. Although IL-1 increased PLA2 activity time-dependently, mepacrine inhibited the activity almost completely. Activation of PLA2 elevated leukotriene C4 and B4 (LTC4 and LTB4), and 6-keto-prostaglandin $F2{\alpha}\;(6-keto-PGF2{\alpha})$ was consumed completely by respiratory burst induced by IL-1. Mepacrine did not alter these changes in the contents of lipid mediators. To estimate the functional changes of alveolar barrier during the oxidative stress, quantitative changes of pulmonary surfactant, activity of gamma glutamyltransferase (GGT), and ultrastructural changes were examined. IL-1 increased the level of phospholipid in the bronchoalveolar lavage (BAL) fluid, which seemed to be caused by abnormal, pathological release of lamellar bodies into the alveolar lumen. Mepacrine recovered the amount of surfactant up to control level. IL-1 decreased GGT activity, while mepacrine restored it. In ultrastructural study, when treated with IL-1, marked necroses of endothelial cells and type II pneumocytes were observed, while mepacrine inhibited these pathological changes. In histochemical electron microscopy, increased generation of oxidants was identified around neutrophils and in the cytoplasm of type II pneumocytes. Mepacrine reduced the generation of oxidants in the tissue produced by neutrophilic respiratory burst. In immunoelectron microscopic study, PLA2 was identified in the cytoplasm of the type II pneumocytes after IL-1 treatment, but mepacrine diminished PLA2 particles in the cytoplasm of the type II pneumocyte. Based on these experimental results, it is suggested that PLA2 plays a pivotal role in inducing acute lung injury mediated by IL-1 through the oxidative stress by neutrophils. By causing endothelial damage, functional changes of pulmonary surfactant and alveolar type I pneumocyte, oxidative stress disrupts microvascular integrity and alveolar barrier.

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토끼 대동맥 평활근의 내피세포 의존성 이완에 미치는 $Ca^{2+}$$Ca^{2+}$ 길항제의 효과 (Effects of Extracellular $Ca^{2+}$ and $Ca^{2+}$-Antagonists on Endothelium-Dependent Relaxation in Rabbit Aorta)

  • 서석효;구용숙;박춘옥;황상익;김기환
    • The Korean Journal of Physiology
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    • 제24권1호
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    • pp.91-102
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    • 1990
  • 토끼 흉부 대동맥을 이용하여 내피세포 의존성 혈관이완에 대한 세포외 $Ca^{2+}$과 여러가지 $Ca^{2+}$ 길항제의 효과를 분석하여 EDRF의 작용기전을 밝혀 보고자 하였다. 대동맥 횡단 절편의 등장성 수축은 $10^{-7}\;M$ 노에피네프린으로 유발시켰으며, $10^{-6}\;M$ 사세틸콜린으로 내피세포 의존성 혈관이완을 일으켰다. 내피세포는 작은 솜뭉치로 부드럽게 문질러서 제거하였으며, hemolysate를 사용하여 EDRF에 대한 헤모글로빈의 효과를 관찰하였다. 결과를 종합하면 다음과 같다. 1) 아세틸콜린에 의한 내피세포 의존성 혈관이완은 두 시기, 즉 초기급속이완기와 후기완만이완기로 나타났다. 2) 세포외 $Ca^{2+}$을 낮추면, 아세틸콜린에 의한 내피세포 의존성 혈관이완이 감소하였으며, 특히 후기완만이완기가 감소하였다. 3) Verapamil, nifedipine, $Mn^{2+}$$Cd^{2+}$은 내피세포 의존성 혈관이완에 영향이 없었던 반면 $La^{3+}$$Co^{2+}$는 억제시켰다. 4) 헤모글로빈을 투여하면 내피세포가 없는 절편에서는 기초긴장도의 변화가 없었으나 내피세포가 있는 절편에서는 기초긴장도가 증가하였고 아세틸콜린에 의한 내피세포 의존성 혈관이완도 완전히 억제되었다. 이상의 결과로부터 세포외 $Ca^{2+}$은 주로 후기완만이완기에 작용하며 이때 사용되는 $Ca^{2+}$ 유입 통로는 $Ca^{2+}$ 길항제로 억제되지 않는 것으로 결론지을 수 있다.

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하천수 내 생물학적 안정성에 따른 유기물 특성변화와 오존산화기반 전처리 연구 (Biological stability in the ozone and peroxone pretreatment systems in river water)

  • 박세희;노진형;박지원;맹승규
    • 상하수도학회지
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    • 제32권2호
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    • pp.159-168
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    • 2018
  • Climate change is believed to increase the amount of dissolved organic matter in surface water, as a result of the release of bulk organic matter, which make difficult to achieve a high quality of drinking water via conventional water treatment techniques. Therefore, the natural water treatment techniques, such as managed aquifer recharge (MAR), can be proposed as a alternative method to improve water quality greatly. Removal of bulk organic matter using managed aquifer recharge system is mainly achieved by biodegradation. Biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) can be used as water quality indicators for biological stability of drinking water. In this study, we compared the change of BDOC and AOC with respect to pretreatment methods (i.e., ozone or peroxone). The oxidative pretreatment can transform the recalcitrant organic matter into readily biodegradable one (i.e., BDOC and AOC). We also investigated the differences of organic matter characteristics between BDOC and AOC. We observed the decreases in dissolved organic carbon (DOC) and the tryptophan-like fluorescence intensities. Liquid chromatographic - organic carbon detection (LC-OCD) analysis also showed the reduction of the low molecular weight (LMW) fraction (15% removed, less than 500 Da), which is known to be easily biodegradable, and the biopolymers, high molecular weight fractions (66%). Therefore, BDOC consists of a broad range of organic matter characteristics with respect to molecular weight. In AOC, low molecular weight organic matter and biopolymers fraction was reduced by 11 and 6%, respectively. It confirmed that biodegradation by microorganisms as the main removal mechanism in AOC, while BDOC has biodegradation by microorganism as well as the sorption effects from the sand. $O_3$ and $O_3+H_2O_2$ were compared with respect to biological stability and dissolved organic matter characteristics. BDOC and AOC were determined to be about 1.9 times for $O_3$ and about 1.4 times for $O_3+H_2O_2$. It was confirmed that $O_3$ enhanced the biodegradability by increasing LMW dissolved organic matter.

후 열처리에 의한 cubic-BN 상과 hexagonal-BN상 혼합 막의 안정성 향상 (Stabilization of cubic-BN/hexagonal-BN Mixed Films by Post-Annealing)

  • 박영준;최제형;이정용;백영준
    • 한국진공학회지
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    • 제9권2호
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    • pp.155-161
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    • 2000
  • 이온빔보조증착법을 이용하여 c-BN(70%)/h-BN(30%) 혼합막을 합성하였으며, 이를 후속 열처리로 안정화 시켰다. 보론은 e-beam evaporator로, 질소는 end-hall type 이온 건으로 공급하였으며, 기판에는 -400과 -500V의 DC 바이어스를 각각 인가하였고, $700^{\circ}C$로 가열하였다. 보론의 기화속도는 1.2 $\AA$/sec였고, 질소이온의 에너지는 약 100 eV였다. 막 합성 후같은 진공에서 후속열처리를 $700^{\circ}C$$800^{\circ}C$에서 1시간동안 각각 행하였다. 후속열처리를 하지 않은 경우에는 공기 중에 노출된 직후에 막이 기판에서 박리된 반면, $800^{\circ}C$에서 후속 열처리를 한 경우에는 안정하였다. 후속 열처리에 의하여 막 전체의 응력은 4.9 GPa에서 3.4 GPa로 감소하였으나, c-BN상의 응력은 변화하지 않았다. 이러한 결과는 c-BN상의 응력 해소를 주요 안정화 기구로 보고한 기존의 결과와 다른 것으로, 후속 열처리 동안에, 비정질이나 결함이 많은 h-BN상의 구조적, 화학적 relaxation에 의하여 막의 안정화가 진행될 수 있음을 의미한다. c-BN상의 분율이 작은 혼합막의 경우 비 c-BN상의 안정화가 막 전체의 안정화에 매우 중요할 것으로 판단된다.

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의안(醫案)을 통한 신종 인플루엔자의 한의학적 대처방안 (A Study on Traditional Korean Medical Countermeasures of Influenza A by Case Histories)

  • 안상영;한창현;권오민;박상영;안상우
    • 대한한의학원전학회지
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    • 제22권4호
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    • pp.221-239
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    • 2009
  • Background: The recent outbreak of the novel strain of influenza A (H1N1) virus has raised a global concern of the future risk of pandemic. Traditional Korean Medicine(TKM) has been combatting against contagious diseases and developed its own particular and efficient way in treating those diseases. Objectives: Provide a distinctive and effective TKM method in understanding the principles of treatment, prevention, and contraindications against influenza A through case histories. Method: We revised case histories of eminent doctors of Ming and Qing dynasties according to their clinical manifestations similar to those of influenza A. We also verified prescriptions of the "Dong-uibogam(東醫寶鑑)" through examining clinical practices of China today. Results: 1. The subtypes of Warm disease; Wind Warmth and Pestilence has the most similar clinical manifestation in comparison to Influenza A. Specifying these terms is important in recognizing and classifying various diseases under the name of Warm disease. 2. TKM considered not only external factors but also individual factors like general condition, diet, emotion, constitutional types, etc in the treatment of febrile diseases. 3. TKM developed a new way in the treatment of contagious diseases. considering the characteristics of each pathogen. TKM described the Warm pathogen being light as a feather, which enters through the nose, principally affecting the Lung. Therefore, they emphasized treatment with Pungent Sweet Cooling Moistening[辛甘凉潤] method. 4. As the conservation of fluid and humor is the primordial concern in the treatment of Warm disease, they restricted release of the exterior with pungent-warm and purgation method. The purgation methods was used exclusively to decrease fever and preserve fluid and humor. 5. The only differentiating characteristics of Influenza A with seasonal influenza are vomiting and diarrhea. Case research revealed the possibility of these manifestations to be a mechanism of restoration. 6. TKM provides alimento prevention method like Mint Pear Porridge, mung bean, and etc also combination of herbal medicine. Also emphasized in the conservation of essence for the prevention of contagious diseases. Conclusions: TKM developed its unique way in understanding the pathogenesis, diagnosis, treatment, and prevention of contagious diseases and formed its independent scheme of Warm Disease. This knowledge in febrile contagious disease is relevant today in providing diverse treatment and prevention for influenza A.

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당지질로 유도한 염증반응에서 Piceatannol의 항염증 기전 연구 (Mechanism Underlying the Anti-Inflammatory Action of Piceatannol Induced by Lipopolysaccharide)

  • 조한진;심재훈;소홍섭;윤정한
    • 한국식품영양과학회지
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    • 제41권9호
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    • pp.1226-1234
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    • 2012
  • 본 연구에서는 염증반응을 조절하는 다양한 신호전달체계를 중심으로 분자생물학적 방법을 통해 piceatannol의 항염증 기전을 규명하였다. LPS로 염증반응을 유도한 Raw 264.7 대식세포에서 piceatannol은 iNOS의 발현 억제를 통해 NO의 생성을 감소시키고 염증성 사이토카인(TNF-${\alpha}$, IL-6, IL-$1{\beta}$)의 생성을 감소시켰다. 염증반응을 조절하는 신호전달체계 중 piceatannol은 LPS에 의해 유도된 $I{\kappa}B$의 분해와 p65의 핵으로의 이동을 억제하고, LPS에 의해 유도된 SAPK/JNK의 인산화를 억제하였다. 또한 piceatannol은 LPS와 IL-6(LPS에 의해 증가됨)에 의한 STAT3의 활성화를 억제하였다. 뿐만 아니라 piceatannol은 Nrf2의 핵 내 축적을 야기하고 ARE의 transcriptional activity를 증가시켜 HO-1의 발현을 증가시켰다. 본 연구의 결과, piceatannol은 NF-${\kappa}B$와 AP-1, STAT3 신호전달의 억제를 통해, 그리고 HO-1의 발현 증가를 통해 항염증 효과를 나타내었다(Fig. 8).

Increase in Intracellular Calcium is Necessary for RANKL Induction by High Extracellular Calcium

  • Jun, Ji-Hae;Kim, Hyung-Keun;Woo, Kyung-Mi;Kim, Gwan-Shik;Baek, Jeong-Hwa
    • International Journal of Oral Biology
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    • 제30권1호
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    • pp.9-15
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    • 2005
  • Recently, we reported that high extracellular calcium increased receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) expression via p44/42 mitogen-activated protein kinase (p44/42 MAPK) activation in mouse osteoblasts. However, the mechanism for p44/42 MAPK activation by high extracellular calcium is unclear. In this study, we examined the role of intracellular calcium increase in high extracellular calcium-induced RANKL induction and p44/42 MAPK activation. Primary cultured mouse calvarial osteoblasts were used. RANKL expression was highly induced by 10 mM calcium treatment. Ionomycin, a calcium ionophore, also increased RANKL expression and activated p44/42 MAPK. U0126, an inhibitor of MEK1/2, an upstream activator of p44/42 MAPK, blocked the RANKL induction by both high extracellular calcium and ionomycin. High extracellular calcium increased the phosphorylation of proline-rich tyrosine kinase 2 (Pyk2), one of the known upstream regulators of p44/42 MAPK activation. Bisindolylmaleimide, an inhibitor of protein kinase C, did not block RANKL induction and p44/42 MAPK activation induced by high extracellular calcium. 2-Aminoethoxydiphenyl borate, an inhibitor of inositol 1,4,5-trisphosphate (IP3) receptor, blocked the RANKL induction by high extracellular calcium. It also partially suppressed the activation of Pyk2 and p44/42 MAPK. Cyclosporin A, an inhibitor of calcineurin, also inhibited high calcium-induced RANKL expression in dose dependent manner. However, cyclosporin A did not affect the activation of Pyk2 and p44/42 MAPK by high extracellular calcium treatment. These results suggest that 1) the increase in intracellular calcium via IP3-mediated calcium release is necessary for RANKL induction by high extracellular calcium treatment, 2) Pyk2 activation, but not protein kinase C, following the increase in intracellular calcium might be involved in p44/42 MAPK activation, and 3) calcineurin-NFAT activation by the increase in intracellular calcium is involved in RANKL induction by high extracellular calcium treatment.

복합지형상에서 비정상 박리흐름에 의한 확산 (Dispersion in the Unsteady Separated Flow Past Complex Geometries)

  • 류찬수
    • 한국지구과학회지
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    • 제22권6호
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    • pp.512-527
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    • 2001
  • 복합지형을 지나는 박리흐름(separated flows)들이 와도 이론에 의해 모델링 되었다. 흐름은 비회전성 및 비점성으로 가정하였으며, 선형 시어흐름에 대한 유선함수를 결정하기 위해 새로운 기법이 기술되었다. 지형지물의 형태로는 snow cornice과 backward-facing step을 정의하였으며, 이러한 지형지물의 후미에는 유체의 박리현상과 역류현상(reattachment)이 생긴다. 유체의 박리현상이 지형지물의 가장자리에 발생되게 하기 위해 점 와도를 흐름에 발생시켰고, 지형지물의 가장자리에 있는 뾰족한 부분을 완화하고 최대곡률 부근에서의 섭동운동에 중요한 박리흐름 발생지점의 구속조건을 없애기 위해 conformal mapping을 수정하였다. 와도 발생지점에서 와도를 평형으로부터 이동시키거나, 또는 임의의 섭동을 초기흐름에 가하는 방식으로 섭동을 가하여 비정상흐름을 발생시켰다. 박리지점의 풍상측에서 연속적으로 방출되고, 또한 bubble의 이차순환에 의해 변형된 물질의 궤적들이 수치적으로 적분되었으며, 시간에 대한 농도누적이 역류지점의 풍하측 고정된 지점에서 계산되었다. 본 연구에 사용된 모델은 방출물질의 확산형태와 간헐성을 제대로 다룰 수 있음을 알 수 있으며, 이산적인 방법에 의한 다중-와도모델 및 수치모델의 결과들과도 일치한다. 본 연구에 의하면, 박리 및 역류현상이 있는 유체의 흐름 속에 순환하는 bubble들의 비정상상태(unsteadiness)는 풍하측에서 대규모의 고농도 누적을 일으키는 주요 원인이다.

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