• Journal of Advanced Marine Engineering and Technology
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• 제20권5호
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• pp.103-113
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• 1996

The properties of the deposited film depend on the deposition condition and these, in turn depend critically on the morphology and crystal orientation of the films. Therefore, it is important to clarify the nucleation occurrence and growth stage of the morphology and orientation of the film affected by deposition parameters, e.g. the gas pressure and bias voltage etc. In this work, magnesium thin flims were prepared on cold-rolled steel substrates by a thermo-eletron activation ion plating technique. The influence of nitrogen gas pressure and substrate bias voltage on their crystal orientation and morphology of the coated films were investigated by scanning electron microscopy (SEM) and X-ray diffraction, respectively. The diffraction peaks of magnesium film became less sharp and broadened with the increase of nitrogen gas pressure. With an increase in nitrogen gas pressure, flim morphology changed from colum nar to granular structure, and surface crystal grain-size decreased. The morphology of films depended not only on gas pressure but also on bias voltage, i.e., the effect of increasing bias voltage was similar to that of decreasing gas pressure. The effect of crystal orientation and morphology of magnesium films on corrosion behaviors was estimated by measuring anodic polarization curves in deaerated 3%NaCl solution. Magnesium, in general, has not a good corrosion resistance in all environments. However, these magnesium films prepared by changing nitrogen gas pressure showed good corrosion resistance. Among the films, magnesium films which exhibited granular structure had the highest corrosion resistance. The above phenomena can be explained by applying the effects of adsorption, occlusion and ion sputter of nitrogen gas.

• Journal of Chest Surgery
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• 제45권2호
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• pp.73-79
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• 2012

Background: Aortic cross clamping is associated with spinal cord ischemia. This study used a rat spinal cord ischemia model to investigate the effect of distal aortic pressure on spinal cord perfusion. Materials and Methods: Male Sprague-Dawley rats (n=12) were divided into three groups. In group A (n=4), the aorta was not occluded. In groups B (n=4) and C (n=4), the aorta was occluded. In group B the distal aortic pressures dropped to around 20 mmHg. In group C, the distal aortic pressure was decreased to near zero. The carotid artery and tail artery were cannulated to monitor the proximal aortic pressure and the distal aortic pressure. Fluorescent microspheres were used to measure the regional blood flow in the spinal cord. Results: After aortic occlusion, blood flow to the cervical spinal cord showed no significant difference among the three groups. In groups B and C, the thoracic and lumbar spinal cord and renal blood flow decreased. No microspheres were detected in the thoracic and lumbar spinal cord of group C. Conclusion: The spinal cord blood flow is dependent on the distal aortic pressure after thoracic aortic occlusion.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권6호
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• pp.545-551
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• 2005

Purpose: The effect of orthognathic surgery on the temporomandibular dysfunction has been controversial. The purpose of this study is to prove statistically that early removal of fixation plate at postoperative 2 weeks with active exercise of mouth opening could relieve preoperative temporomandibular dysfunction and reposition of temporomandibular joint. Patients and Methods: All 28 subject patients underwent mandibular setback with BSSRO in Kyunghee medical center by one surgeon. The fixation plates used for rigid fixation were removed at postoperative 2 weeks and we had the patients excercise active mouth opening with intermaxillary rubber rings for the guiding proper postoperative occlusion. Temporomandibular symptoms were checked and radiographs were taken before surgery, within a month after surgery, six to twelve months after surgery respectively. Results: The temporomandibular dysfunction symptoms were relieved after the surgery and the condyle was displaced inferior-posteriorly immediate after surgery and repositioned toward its original position during follow-up periods. Conculusion: Orthognathic surgery may benefit temporomandibular joint dysfunction by obtaining a postoperative stable occlusion and more physiologic neuromuscular function. The early removal of fixation plates after BSSRO could reposition the temporomandibular joint to physiologic position and relieve the symptoms of temporomandibular dysfunction by permitting movement of proximal segment.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.697-700
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• 2006

본 연구에서는 가정이나 일반 사무실 등에서 편리하게 하부요로계의 폐색을 진단하기 위하여 요속과 동시에 배뇨 시 발생하는 요류음을 계측할 수 있는 센서 및 계측 시스템을 구현하였다. 구현된 시스템은 로드셀을 이용한 요속계측센서, 청진기형 요류음 계측센서, 센서신호의 검출을 위한 전처리부, 신호의 증폭 및 필터부, 시스템 제어부, PC 계측 프로그램 등으로 구성되었다. 구현된 시스템의 평가를 위하여 하부요로계를 모식화한 실험장치를 구현하였다. 구현된 실험장치를 이용하여 요속 및 요음을 계측하고 시간영역과 주파수영역에서의 분석을 통해 하부요로계의 폐색을 가장 잘 반영하는 특징파라미터를 추출하고자 하였다. 그리고 구현된 시스템의 임상적용 가능성을 평가하기 위하여 정상인 5병을 대상으로 요속 및 요류음을 계측하고 분석하였다. 그 결과 요류음 신호의 $253\sim282Hz$ 대역이 폐색의 정도를 가장 잘 반영하는 것으로 나타났다.

• Journal of Chest Surgery
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• 제54권2호
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• pp.117-126
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• 2021

Background: Several factors, such as the degree of target vessel stenosis, are known to be associated with radial artery (RA) graft patency in coronary artery bypass grafting (CABG). There is a lack of data regarding the effect of the RA proximal configuration (aortic anastomosis versus T-anastomosis). This study evaluated the effects of the RA proximal configuration on the patency rate and clinical outcomes after CABG. Methods: We conducted a retrospective study, analyzing 328 patients who had undergone CABG with an RA graft. We divided the patients into 2 groups. The primary endpoint was RA patency and the secondary endpoints were overall mortality and major adverse cardiac and cerebrovascular events (MACCE). We performed a propensity score-matched comparison. Results: Aorta-RA anastomosis was performed in 275 patients, whereas the rest of the 53 patients received T-RA anastomosis. The mean age was 67.3±8.7 years in the T-RA anastomosis group and 63.8±9.5 years in the aorta-RA anastomosis group (p=0.02). The mean follow-up duration was 5.13±3.07 years. Target vessel stenosis ≥70% (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.91; p=0.03) and T-RA anastomosis configuration (HR, 2.34; 95% CI, 1.01-5.19; p=0.04) were significantly associated with RA occlusion in the multivariable analysis. However, T-RA anastomosis was not associated with higher risks of overall mortality and MACCE following CABG (p=0.30 and p=0.07 in the matched group, respectively). Conclusion: Aorta-RA anastomosis showed a superior patency rate compared to T-RA anastomosis. However, the RA proximal anastomosis configuration was not associated with mortality or MACCE.

• Journal of Korean Biological Nursing Science
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• 제2권2호
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• pp.67-80
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• 2000

The purpose of this study was to identify hindlimb muscle atrophy in stroke induced rat and determine the effect of endurance exercise on body weight, weight of hindlimb muscle during 7 days after stroke induction. Thirty four male Sprague-Dawley rats with 200-270g body weight were divided into four groups : control, control+exercise(Con+Ex), stroke, and exercise after stroke(St+Ex) group. The control group and Con+Ex group received sham operation and the stroke group and St+Ex group received right MCA occlusion operation by using silicon-coated probe. The Con+Ex and St+Ex groups ran on a treadmill for 20min/day at 10m/min and $10^{\circ}grade$. Daily body weight and diet intake were measured every morning for 7 days. Cerebral infarction of stroke and St+Ex groups were identified by staining with TCC for 30minutes. The data were analyzed by Kruskal-Wallis test and Mann-Whitney U test using the SPSSWIN 9.0 program. Body weight of the control group at the 7th day increased by 18.3% significantly from the first day of experiment, that of the stroke group at the 7th day decreased by 6.7% significantly compared to the day of receiving right MCA occlusion operation. Body weight of the Con+Ex group at the 7th day increased by 10.3% significantly form the first day of experiment, that of St+Ex group at the 7th day also increased by 13.4% significantly compared to the day of receiving right MCA occlusion operation. The total amount of diet in stroke group decreased significantly compared to that of St+Ex and that of control group. In stroke group the wet weight of both sides of soleus, plantaris, and gastrocnemius muscles decreased significantly compared to that of control group. The relative weight of affected(left) plantaris and gastrocnemius muscles decreased significantly compared to that of the control group. The difference between the weight of affected and unaffected soleus, plantaris, and gastrocnemius muscles were not significant in stroke group. The wet weight of right gastrocnemius muscles in Con+Ex group increased compared to that of control group. The relative weight of right gastrocnemius muscle increased significantly compared to that of the control group. The wet weight of St+Ex group increased significantly compared to that of the stroke group in both sides of soleus, plantaris, and gastrocnemius muscles. The relative weight of affected plantaris muscle increased significantly compared to that of the stroke group. The difference between the weight of affected and unaffected soleus, plantaris, and gastrocnemius muscles were not significant in St+Ex group. Body weight and wet weight of soleus, plantaris, and gastrocnemius muscles in the St+Ex group did not recover to the values of control group. Based on these results, it can be suggested that endurance exercise during acute stage of stroke can reduce muscle atrophy related to denervation, inactivity and undernutrition.

• Journal of Korean Neurosurgical Society
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• 제29권2호
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• pp.167-179
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• 2000

Objective : We studied to clarify the effective time zone of mild hypothermic neural protection during ischemia and/or reperfusion after middle cerebral artery occlusion. Methods : In a reversible cerebral infarct model which maintained reperfusion of blood flow after middle cerebral artery occlusion for two hours, the size of cerebral infarction, cerebral edema and the extent of neurological deficit were observed and analyzed for comparison between the control and the experimental groups under hypothermia($33.5^{\circ}C$). The temporalis muscle temperature was reduced to $33.5^{\circ}C$ by surface cooling for two hours during middle cerebral artery occlusion for study group I. The following groups applied hypothermia for two-hour periods after reperfusion : group II(0-2 hours), group III(2-4 hours), and group IV(4-6 hours). They were rewarmed to $36.5^{\circ}C$ until sacrified at 2, 4, 6, 12, and 24 hours after reperfusion. Control group was maintained at normothermia without hypothermia. Results : In the experimental groups with hypothermia, the average value of the size of cerebral infarction($mean{\pm}SD$) was $1.97{\pm}1.65%$, which was a remarkable reduction over that of the control, $4.93{\pm}3.79%$. In the control, a progressive increase was shown in the size of infarction from point of reperfusion to 6 hours after reperfusion without further changes in size afterward. Intra-ischemic hypothermia(group I) prevented ischemic injury but did not prevent reperfusion injury. Group II examplified the most neural protective effect in comparison to the control group and group IV(p<0.05). The cortex was more vulnerable to reperfusion injury than the subcortex. Mild hypothermia showed more neural protective effects on the cortex than subcortex. Conclusion : The most appropriate time zone for application of mild hypothermia was defined to be within four hours following reperfusion.

• Pediatric Infection and Vaccine
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• 제17권2호
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• pp.114-121
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• 2010

목적 : 고막체온계는 신체내의 점막과 접촉 없이 고막을 통해 심부체온을 신속히 간편한 방법으로 측정할 수 있어 영아와 소아들에서 많이 사용된다. 본 연구에서는 한쪽에만 중이염, 귀지가 있는 경우 양쪽 고막체온이 어떻게 달라지는지 연구하였다. 방법 : 2008년 6월부터 9월까지, 2010년 1월부터 5월까지 본원 소아청소년과 외래에 내원한 소아 중 비디오 이경을 통해 중이염과 귀지가 없는 정상군 50명, 한쪽에만 고막이 안보이게 귀지가 가득 있는 군 50명, 한쪽에만 중이염을 가진 군 186명의 3개 군을 대상으로 하였다. 고막체온은 Braun Thermoscan을 이용해 양쪽 귀에서 2초간 측정하였고, 15분 뒤 다시 측정하였다. 중이염을 가진 군은 비디오 이경으로 확인하여 염증정도에 따라 분류하여 비교하였다. 통계처리는 SPSSWIN 12.0을 사용하였고 paired T-test와 one way anova를 이용하여 분석하였다. 결과 : 정상 군과 한쪽에만 귀지가 있는 군에서는 양쪽 고막체온의 통계적인 차이는 없었다. 한쪽에만 중이염이 있는 군에서는 중이염이 있는 쪽의 고막이 평균 $0.13{\pm}0.20^{\circ}C$ 높았고 통계적인 차이가 있었다($36.99{\pm}0.54^{\circ}C$ vs $36.86{\pm}0.52^{\circ}C$ P<0.001). 중이염의 단계에 따른 양쪽 고막의 체온차이는 통계적으로 유의하지 않았다. 결론 : 고막체온계는 스트레스 없이 쉽고 빠르게 체온을 측정할 수 있다. 적절한 방법으로 측정한다면 양측 고막체온에는 큰 차이가 없을 것으로 생각되나, 중이염이 있을 때엔 양쪽 고막체온에 차이가 있을 수 있음을 주의 해야겠다.

• 대한본초학회지
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• 제23권2호
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• pp.203-212
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• 2008

Objectives : This study was performed to prove the anti-hypertensive and anti-diabetic effect of Mori Ramulus(MR). Methods : The examination was done on the femoral artery occlusion of the rat, and check the blood pressure. In addition, we observed therapueutic effects on diabetes rats induced by streptozotocin. Results : MR MeOH Ex, showed few effect on descending blood pressure in SD rat model. MR CHC13 layer (MRC) showed significant effect on descending blood pressure. MR was effective on the streptozotocin-induced diabetes SD rats. Especially MRC reduced the amount of serum glucose, BUN, triglyceride and insulin level. Conclusions : MRC could induce descending blood pressure in the rat model. Also, it is expected to be effective in diabetes treatment.

• Mycobiology
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• 제48권3호
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• pp.228-232
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• 2020

Cordyceps is a genus of ascomycete fungi and is well known as one of the important medical fungi in Chinese, Korea, and other Asian countries, because of its various beneficial effects on human health. The pharmacological activities of Cordyceps extract are mainly focused on anti-cancer, anti-metastatic, and immune modulating effects. In the present study, we investigated whether the antiplatelet effect of ethanol extract of cultured Cordyceps militaris (CMEE) with FeCl₃-induced arterial thrombosis model. We observed that CMEE exhibited a significant inhibitory effect against ADP and collagen-induced platelet aggregation. However, there were no significant differences in prothrombin time (PT) and activated partial thromboplastin time (aPTT). These results suggest that antithrombotic activity of CMEE is related to antiplatelet effect rather than anticoagulation effect, and CMEE may be a positive effect on improving blood circulation against vessel injury and occlusion.