• 제목/요약/키워드: Transient Flow

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허혈성 뇌졸중 유발 백서에서 수중운동이 하지근 및 대뇌의 HSP 70 발현에 미치는 영향 (Effects of Swimming Exercise on Hind-Limb Muscles and HSP 70 Expression in the Ischemic Stroke Model of Rats)

  • 김기도;김은정;천진성;김경윤;김계엽;유영대
    • 한국전문물리치료학회지
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    • 제13권3호
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    • pp.57-66
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    • 2006
  • Ischemic stroke results from a transient or permanent reduction in cerebral blood flow that is restricted to the territory of a major brain artery. Thus, this study was performed to examine (1) the effects of swimming exercise on the improvement of muscle atrophy, and (2) exercise and HSP 70 expression in an ischemic stroke model induced by middle cerebral artery occlusion. The results of this study were as follows: One week after ischemic stroke was induced, changes appeared in the muscle weight of the gastrocnemius muscle due to muscle atrophy in the affected side. Group II showed statistically significant difference from group III eight weeks after ischemic stroke was induced. (p<.05). One week and eight weeks after ischemic stroke was induced there was significant decrease in the relative muscle weight of the gastrocnemius muscle in each group except Group IV, while there was statistically significant increase in group II eight weeks after ischemic stroke was induced, compared to group III (p<.05). For neurologic exercise behavior tests, Group II generally had the highest score, compared to other groups. In immunohistochemical observations, Group II showed a decrease in HSP 70. The above results suggest that swimming exercise improved muscle atrophy, changed the HSP 70 expression of ischemic stroke in rats, and contributed to the improvement of exercise function.

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Exosomes Secreted by Toxoplasma gondii-Infected L6 Cells: Their Effects on Host Cell Proliferation and Cell Cycle Changes

  • Kim, Min Jae;Jung, Bong-Kwang;Cho, Jaeeun;Song, Hyemi;Pyo, Kyung-Ho;Lee, Ji Min;Kim, Min-Kyung;Chai, Jong-Yil
    • Parasites, Hosts and Diseases
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    • 제54권2호
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    • pp.147-154
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    • 2016
  • Toxoplasma gondii infection induces alteration of the host cell cycle and cell proliferation. These changes are not only seen in directly invaded host cells but also in neighboring cells. We tried to identify whether this alteration can be mediated by exosomes secreted by T. gondii-infected host cells. L6 cells, a rat myoblast cell line, and RH strain of T. gondii were selected for this study. L6 cells were infected with or without T. gondii to isolate exosomes. The cellular growth patterns were identified by cell counting with trypan blue under confocal microscopy, and cell cycle changes were investigated by flow cytometry. L6 cells infected with T. gondii showed decreased proliferation compared to uninfected L6 cells and revealed a tendency to stay at S or G2/M cell phase. The treatment of exosomes isolated from T. gondii-infected cells showed attenuation of cell proliferation and slight enhancement of S phase in L6 cells. The cell cycle alteration was not as obvious as reduction of the cell proliferation by the exosome treatment. These changes were transient and disappeared at 48 hr after the exosome treatment. Microarray analysis and web-based tools indicated that various exosomal miRNAs were crucial for the regulation of target genes related to cell proliferation. Collectively, our study demonstrated that the exosomes originating from T. gondii could change the host cell proliferation and alter the host cell cycle.

메탄화재의 이산화탄소 생성법에 의한 화재발열량 측정 (Measurement of Heat Release Rate by Carbon Dioxide Generation Method for Methane Fire)

  • 김성찬
    • 한국화재소방학회논문지
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    • 제34권2호
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    • pp.1-6
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    • 2020
  • 연소상태의 가연물에서 방출되는 에너지는 비정상적인 특성과 폭넓은 크기규모를 가지기 때문에 다른 화재물리량에 비해 측정하기 어려운 문제 중의 하나로 인식된다. 본 연구는 실험실규모의 화재 발열량계에서 이산화탄소생성법과 산소소모법에 의해 계산된 측정 발열량을 비교하여 상대오차를 분석하였다. 메탄 버너화재에 대해 산소소모계수와 CO2 질량유량의 상관관계는 6% 이내에서 우수한 선형성을 보였다. CDG법의 계산에서 CO에 의한 발열량 기여분은 CO2에 의한 기여분에 비해 7% 이내로 크지 않게 나타났다. 준정상상태의 기준 버너 발열량 대비 OC법과 CDG법의 선형성은 1% 이내를 보여 발열량 측정에 있어서 CDG법은 상호 보완할 수 있는 측정수단으로 활용될 수 있다.

새로운 Anthracycline계 항암제 DA-125의 일반약리작용 (General Pharmacology of DA-125, A New Anthracycline Anticancer Agent)

  • 김명석;박종완;김영훈;김순회;신명수;김원배;양중익
    • 대한약리학회지
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    • 제30권2호
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    • pp.227-242
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    • 1994
  • The general pharmacological effects of a new anthracycline anticancer agent, DA-125 $[7-0-(2,\;6-dideoxy-2-fluoro-{\alpha}-L-talopyranosyl)-adriamycinone-14-{\beta}-alaninate{\cdot}HCI]$ were investigated in mice, rats, guinea pigs, rabbits and dogs. Intravenous administration of DA-125 presented no significant effects on the central and peripheral nervous systems of ICR mice except a decrease in the numbers of acetic acid-induced writhing response at a dose of 10 mg/kg. In anesthetized rats and dogs, DA-125 produced a transient depression of blood pressure and an increase in heart rate, but did not affect the peripheral blood flow in the isolated ear vessels of rabbits and the mechanical functions of the isolated hearts of guinea pigs. No significant effects were observed on the gastrointestinal functions and the contractilities of smooth muscle preparations obtained from guinea pig trachea, rabbit ileum, pregnant and non-pregnant uterus and vas deferens of rats. DA-125 Increased the contractility of the isolated ileum of guinea pigs in a dose range of $10^{-6}{\sim}10^{-9}g/ml$, and also increased, but weaker than adriamycin, the vascular permeability in rat skin. DA-125 had no effect on the kallikrein-induced increase in permeability and the permeability of the visceral organs. DA-125 did not adversely affect the liver function and the blood coagulation system, and did not induce hemolysis in vitro. It is concluded from the results that the general pharmachological effects of DA-125 are similar to or weaker than those of adriamycin, and that little adverse effects are anticipated with a therapeutic dose range.

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방향파 펄스 가열에 의한 ${Al}_{2}{O}_{3}, {Si}_{3}{N}_{4}$, SiC 계열의 열물성치 측정에 관한 연구 (A study on the measurement of thermophysical properties of ${Al}_{2}{O}_{3}, {Si}_{3}{N}_{4}$ and SiC series by a single rectangular pulse heating)

  • 차경옥;장희석;이흥주
    • 대한기계학회논문집
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    • 제14권1호
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    • pp.145-156
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    • 1990
  • 본 연구에서는 시편을 유한원판으로 하고 방형파펄스가열을 채용한 경우 이론 적인 검토와 실험측정으로서 그 방법을 적용할 때 측정장치와 컴퓨터를 직접 접속시켜 시료의 열물성치인 열확산계수와 비열 그리고 열전도계수를 보다 높은 정확도로 측정 하였다. 또한 고온에 있어서 시료표면으로부터 그 주위에 방출하는 열물질을 고헌하 였고, 초기조건및 경계조건을 실험조건과 부합되도록 가정함으로써 무차원 온도상승을 구할 수 있는 열전달 지배방정식의 해를 변수분이법으로 해석하였다. 측정에 사용했 던 시료는 내연기관, 열교환기, 기계요소, 화학반응장치 등 기계구조용 및 기계부품용 재료로서 내식성이 우수하면서, 고온도하에서 강도가 크고, 열팽창계수가 비교적 적고, 열적변형이 적은 고성능세라믹인 알루미나(Al$_{2}$O$_{3}$),탄화규소(SiC), 질화규소 (Si$_{3}$N$_{4}$) 계열을 상온에서 약 1300K 온도범위까지 열물성치를 측정하고, 동 일계통의 시료라 할지라도 화학조성을 중량비율로 첨가했을 경우 열물성치가 다르기 때문에 그들 사이의 관계에 대해서도 검토하였다.

혈희석 체외순환에 의한 개심수술: 16례 수술 경험 (Clinical Experience of Open Heart Surgery Under The Extracorporeal Circulation With Partial Hemodilution: Operation 16 Cases)

  • 유회성
    • Journal of Chest Surgery
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    • 제10권2호
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    • pp.299-314
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    • 1977
  • Clinical experience on 16 cases of open heart surgery under the extracorporeal circulation with mild or moderate hypothermia and partial hemodilution technique at the National Medical Center during the period from June 1976 to October 1977. Nine of sixteen were congenital heart disease and seven were acquired heart disease. The age of the patient ranged between 6 and 48 years. The body weight varied from 18.5kg to 60kg and body surface area 0. 79-1.70m2. The average priming volume of pump oxygenator was 2080 ml, which was consisted fresh ACD blood, buffered Hartmann`s solution, Mannitol, 50% dextrose in water and Vit. C. The average hemodilution rate was 27%. The average flow 2.3 L/min/m2 or 80 ml/min and the duration of perfusion varied from 31 min to 270 min with average of 107 min. The perfusion was carried out under the mild or moderate hypothermia using core cooling alone in 10 cases, core cooling and local myocardial cooling with $0-4^{\circ}C$ physiologic saline in 2 cases. From a hemodynamic point of view, the blood pressure dropped down around 80 mmHg after the initiation of perfusion follwed by increase to safety level and stable during the perfusion. The central venous pressure remained within normal limits. In most cases, hemoglobin and hematocrit decreased during and after the perfusion. Hemogiobin level was decreased, average of 20.6 %, hematocrit 18.6%, pletelets 55% postoperatively. Plasma hemoglobin increased moderately, from preperfusion average valve of 7.79 mg % to post-perfusion value of 54.7 mg %. Electrolytes changes during cardiopulmonary bypass showed definite hypokalemia but changes of Na, Ca were not definite. Arterial blood gas analysis during cardiopulmonary bypass suggested that the metabolic acidosis which was accompanied by respiratory alkalosis which was corrected postoperatively. As the opera tive complication, transient hemoglobinuria in 4 cases and neurological signs in 2 cases were all cured. There were 2 death cases and operative mortality rate was 12.5%.

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공기를 작동 유체로 하는 열다이오드의 열성능에 관한 실험적 연구 (An Experimental Study on the Thermal Performance of Air Filled Thermal Diode)

  • 박이동;장영근;황인주
    • 태양에너지
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    • 제17권2호
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    • pp.35-42
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    • 1997
  • 열다이오드란 유체의 밀도차에 기인한 대류에 의하여 일방향성 열전달이 주로 일어나며 역방향의 열전달은 미미하도록 고안된 장치이다. 본연구에서는 실용적인 측면에서 평행사변형 형상과 직사각형 형상을 조합하고 좌우에 수직 평판을 설치하였으며, 내부 안내판을 가진 공기식 열다이오드를 제작하여 천이 및 정상상태에 관한 연구를 하였다. 공급된 열속에 따른 $Gr^*$$1.11{\times}10^{10}{\sim}1.4{\times}10^{10}$ 사이에 존재하였고 전체 실험 과정에 있어서 $Gr^*$ 값은 ${\pm}3%$ 이내로 유지되었다. $Gr^*$의 증가에 따라 Nu값은 거의 선형적으로 증가하는 경향을 보였으며 guide vane의 유무와 유동통로의 깊이(channel depth)에 따라서는 민감한 경향을 보였다. 경사각의 변화에 따라 온도상태가 무차원시간 $0.5{\sim}0.6$ 에서 나타나는 것으로 보아 시스템의 특성으로 본다.

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척추기저동맥부전환자를 천마구등음(天麻鉤藤飮)으로 치료한 치험 1례 (A case of the patient treated with Chunmagudung-um who was diagnosed with Vertebrobasilar insufficiency)

  • 송철민;장통영;임은경;이윤재;이정섭;신선호;이인;문병순;정현애
    • 대한한방내과학회지
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    • 제26권3호
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    • pp.699-707
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    • 2005
  • Vertebrobasilar insuffciency(VBI) is also refered to as vertebrobasilar transient ischemic attack(V-B TIA). Vertebrobasilar insufficiency is often undiagnosed or misdiagnosed due to complexity of the symptoms. Transcranial doppler(TCD) can be used to possible to record the blood flow velocities in the cerebral arteries through the intact cranium. Transcranial doppler and magnetic resonance angiography(MRA) are both noninvasive techniques that can be used in vertebrobasilar insufficiency, but transcranial doppler is more sensitive with respect to evaluating stenotic lesion of the arteries than magnetic resonance angiographv. Diagnostic values of transcranial doppler were assessed in patients with vertebrobasilar insufficiency. A case of vertebrobasilar insufficiency is here reported. A 62-year-old man with dizzness, nausea and tremor because of vertebrobasilar insufficiency was admitted at Wonkwang Oriental Medicine Hospital. He was treated with the herbal medicine Chunmagudung-um and with acupunture. Results showed improvement of symptoms and favorable transcranial doppler readings. The process used in this successful treatment is here described.

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환경조건변화에 대한 실리콘애자의 누설전류 파형분석 (Waveform analysis of leakage current on silicon insulator for various environment condition variation)

  • 박재준
    • 정보학연구
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    • 제7권2호
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    • pp.69-76
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    • 2004
  • 본 논문은 여러 가지 환경조건하(염무, 안개, 비)에서 오손된 실키콘애자의 누설전류파형과 파형의 스펙트럼 분석 결과를 나타내었다. 200ms동안 누설전류의 크기가 더욱 커지면 커질수록, 60Hz에서의 스펙트럼의 크기도 커짐을 알 수 있었다. 만일 오손된 애자들이 고밀도의 염무에 접촉되면 낮은 스펙트럼을 갖은 누설전류파형이 계측되었고, 간헐적으로 높은 파형이 계측되었다. 누설전류자료 분석의 경우, 전기적인 활동은 염무 측정시 애자표면에 누적된 오손물질로 인한 일시적인 아크거동으로 특성지어진다. 이것은 애자표면을 따라 흐르는 누설전류에 대한 경로를 제공하게 된 것이다. 그것은 특별한 애자의 퍼포먼스 측정을 평가하기위하여 오손누적의 지표를 갖은 것으로서 중요한 것이다. 만일 표면 저항의 떨어짐이 크게 되면, 그때의 누설전류는 전력품질이 저하시킨 섬락을 중단시키는 공급된 전류이 점차로 증가되어진다.

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EFFECT OF INLET LOADING RATE ON THE ELIMINATION OF HYDROGEN SULFIDE AND AMMONIA IN IMMOBILIZED CELL BIOFILTERS

  • Kim, Jung-Hoon;Rene, Eldon R.;Park, Seung-Han;Park, Hung-Suck
    • Environmental Engineering Research
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    • 제11권5호
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    • pp.285-291
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    • 2006
  • Biofiltration is a simple, effective, economically viable and the most widely used gas treatment technique for treating malodors at low concentrations and high flow rates. This paper reports the performance of two lab scale immobilized cell biofilters operated in continuous mode for hydrogen sulfide ($H_2S$) and ammonia ($NH_3$) removal. The removal efficiency (RE, %) and the elimination capacity (EC, $g/m^3{\cdot}hr$) profiles were monitored by subjecting the biofilters to different loading rates of $H_2S$ (0.3 to $8\;g/m^3{\cdot}hr$) and $NH_3$ (0.3 to $4.5\;g/m^3{\cdot}hr$). The removal efficiencies were greater than 99% when inlet loading rate to the biofilters were upto $6\;gH_2S/m^3{\cdot}hr$ and $4\;gNH_3/m^3{\cdot}hr$ respectively. The performance of the biofilters were also ascertained by conducting shock loading studies at a loading rate of $10\;gH_2S/m^3{\cdot}hr$ and $6\;gNH_3/m^3{\cdot}hr$. The results from this study show high removal efficiency, good recuperating potential and stability of the immobilized microbial consortia to transient shock loads.