• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.513-514
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• 2006

Recently intradiscal electrothermal therapy is introduced, which is a new and minimally invasive technique fer the treatment of discogenic low back pain. This procedure involves the percutaneous threading of a flexible catheter into the disc under fluoroscopic guidance. The catheter, composed of thermal resistive coil, heats the posterior annulus of the disc, causing contraction of collagen fibers and destruction of afferent nociceptors. This study tries to investigate the effects of the important factors of this procedure such as heat source temperature and heat applying time on the temperature distribution within the intervertebral disc. This study utilized both computer simulation and the experiment for the verification of finite element analysis. FE analysis was carried out with ANSYS v7.0 (ANSYS Inc, USA) using 10,980 number of brick element and 12,551 number of node. The functional spinal units of 5 month old swine were used for the experiment and the temperature was monitored using 10 channel temperature measurement device MV200. Through this study, it was able to analyze the temperature range of inner intervertebral disc by two mechanisms which are known to alleviate pain clinically. The results showed that when the heat source temperature was kept up 80 degree for 1,020 seconds, the temperature of inner annulus reached at 45 degree up to the distance of 15.6mm from heat source, which explains coagulation of inner annulus by heat. When the same heat source was used, the temperature of inner nucleus reached at 60 degree up to the distance of 9mm from heat source, which explains contraction of inner nucleus by heat.

• 한국물환경학회지
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• 제34권5호
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• pp.503-513
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• 2018

Freshwater cyanobacterial genus Dolichospermum is one of the most commonly spotted types of phytoplankton, whereas a limited number of studies on morphology of Dolichospermum spp. have been performed in South Korea. The purpose of this study is to investigate the succession pattern of cyanobacteria after weir construction, as well as morphological characteristics of Dolichospermum spp. from natural samples collected in the weir regions of Nakdong River. A total of 31 cyanobacterial taxa observed in this study were classified as belonging to 15 genera, 5 families, and 3 orders. Among them, morphological characteristics in the four species were classified into genus Dolichospermum, for most of the planktic former members of the genus Anabaena, were observed through light microscopy. Water bloom frequently occurred in the middle region of Nakdong River, the maximum number of cyanobacterial species appeared in the lower region of Nakdong River. The appearance of order Chrooccocales was only observed during summer when population density of Microcystis aeruginosa reached an annual peak. In contrast, filamentous cyanobacteria was observed throughout the whole year, even if when water temperature was lower than $5^{\circ}C$. It implied that the low-temperature-adapted filamentous cyanobacteria can grow in a range of water temperatures. Coil diameter of D. crassum from natural samples was $75{\sim}140{\mu}m$ ($ave.=91.3{\mu}m$; n = 94), slightly larger than those reported by previous studies. Dolichospemum smithii ($Kom{\grave{a}}rek$) Wacklin et al. 2009, was described for the first time in Nakdong River.

• 한국잠사곤충학회지
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• 제27권1호
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• pp.1-11
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• 1985

1979년 경북지방에서 발생한 병잠으로부터 분리된 새로운 미포자충 K79의 형태, 성장, 발육경과 및 분류학적 위치를 구명하기 위하여 포자의 병원성, 광학현미경에 의한 감염조직의 소견, 전자현미경적 소견을 조사한 결과는 다음과 같다. K79포자의 병원성은 N. bombycis 보다 약하였고 누에에 대한 K79의 감염부위는 중양피막세포, 혈구, 기관피막, 지방조직, 견사선이었다. K79의 발육과정은 sporoplasm, schizont, sporont, sporoblast, spore의 단계로서 N. bombycis와 유사하였으나 발육속도는 늦었다. 미포자충 포자의 전자현미경적인 미세구조는 포자외각의 돌출부와 돌출부사이가 44.28mm였다. 또한 anchoring disk는 우산형이었고 polaroplast, lamellae는 manubroid 상단부에 부착되어 있었다. 극사의 coil 전회수는 K79 16회이고 coil 각도는 75$^{\circ}$였고, 핵은 두 개의 연핵으로 되어 있어 분류학적으로 보면 Nosema 속에 속하는 신종의 미포자충이라고 사료되며 그 표기는 Nosema sp. K79로 기록함이 타당하다고 본다.

• 대한디지털의료영상학회논문지
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• 제13권2호
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• pp.83-90
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• 2011

To prospectively determine the diagnostic performance a combination of standard bolus-chase magnetic resonance (MR) angiography and MR angiography with time-resolved imaging of contrast kinetics (TRICKS) for depicting severity of the head and neck vascular diseases. Over a period of two months, A total of 100 patients(average ages : $50{\pm}8$, male : 60, female : 40) with head and neck vascular diseases were performed on the GE excite 3.0 T units with 8-channel head coil and 4-channel NV coil. Imaging parameters for a typical study were as follow: SBC(TR/ TE/ FA/ SliceThicken./ Slab/ Freq./ FOV/ BW/Scan Time) = 5.4/ min/ 30/ 2/ zip2/ 70/ $224{\times}448$/ 30/ 62.50/ 28, TRICKS(TR/ TE/ FA/ Slice Thicken/Slab/ Freq./ FOV/ BW/ Temp Res./ Scan Time = 3.6/ min/ 25/ 4/ 30/ $160{\pm}384$, zip512/ 30/ 100/ 1 to 1.5/ 23). The analysis of all MR images, which have respect-ively classified two techniques into some diseases. The results of the former were divided into two groups(SBC, TRICKS)with 4 grading of two reader, respectively. Wilcoxon signed rank test was used to determine if a significant difference between imaging techniques existed(p < 0.05). In 33 of 100 patients, arterio-venous malformation was 11% at TRICKS, subclavian vein stenosis : 8%, fistular sinus : 4%, jugular vein stenosis:6%, Middle Cerebral Artery bypass surgery : 4%, p < 0.05). The rest of 67 patients were considered as the results of SBC(14% in the basilar artery stenosis, carotid stenosis : 16%, vertebral stenosis : 17%, central neuro-cytoma : 5%, meningioma : 5%, Not appliable : 10%, p < 0.05). Sensitivity and specificity of TRICKS MR angiography in SVS, FS, JVS, MCABS were improved compared with those at standard MR angiography. In SBS MR angiography which were improved in BAS, CS, VS, CN, Meningioma. In conclusion, TRICKS MR angiography of the SVS, FS, JVS, MCABS is superior to standard MR angiography regarding the number of diagnostic grading. The SBS MR angiography were improved in BAS, CS, VS, CN, Meningioma. and assessment of the degree of luminal narrowing on both TRICKS and SBS.

• Journal of Korean Neurosurgical Society
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• 제63권1호
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• pp.56-68
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• 2020

Objective : To analyze the incidence and treatment trends of hemorrhagic stroke (HS), according to HS subtypes, using nationwide data in Korea from January 2008 to December 2016. Methods : We used data from the national health-claim database provided by the National Health Insurance Service for 2008-2016 using the International Classification of Diseases. The crude incidence and age-standardized incidence of each disease associated with HS, which included intracranial aneurysm (IA), hypertensive intracerebral hemorrhage (ICH), and arteriovenous malformation (AVM), were calculated and additional analysis was conducted according to age and sex. Changes in trends in treatment methods and number of treatments were analyzed for each cerebrovascular disease using the Korean Classification of Diseases procedure codes. Results : In 2016, the total number of newly diagnosed adult patients with HS was 24169, showing a decrease by 7.0% since 2008; the age-standardized incidence of HS was 46.2 per 100000 person-years. The age-standardized incidence of unruptured IA (UIA) in adults was 71.4 per 100000 person-years-increased by 2.6-fold since 2008-while that of ruptured IA (RIA) was 12.6 per 100000 person-years, which had decreased at a rate of 20.3% since 2008. The number of coil embolization (CE) for UIA increased by 3.4-fold over 9 years and exceeded that of clipping since 2008. With respect to RIA, CE increased by 2.0-fold over 9 years and exceeded that of clipping from 2014. As for spontaneous ICH in adults, the age-standardized incidence was 31.3 per 100000 person-years in 2016-decreased by 34.7% since 2008-and 14.6% of patients diagnosed with ICH were treated in 2016, which was not significantly different from the proportion of patients treated since 2008. The age-standardized incidence of unruptured AVM (UAVM) was 2.0 per 100000 person-year in 2016, while that of ruptured AVM (RAVM) was 2.4 per 100000 person-years in 2016, showing a decreasing rate of 17.2% from 2008. The total number of treated patients with AVM declined since 2014. Conclusion : In Korea, age-related cerebral vascular diseases, such as RIA, ICH, and RAVM, demonstrated a declining trend in age-standardized incidence; meanwhile, UIA and UAVM demonstrated an increased trend in both crude incidence and age-standardized incidence for 9 years. The increase in the elderly population, management of hypertension, and development of diagnostic and endovascular techniques appear to have influenced this trend.

• 대한영상의학회지
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• 제82권5호
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• pp.1258-1273
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• 2021

목적 풍선-스텐트 테크닉(balloon-stent technique; 이하 BST)은 복잡한 동맥류를 치료하는 보조술로서 그 고유한 장점을 가지고 있다. 저자들의 기관에서 Atlas의 출시 이래 Scepter-Atlas 조합의 BST를 치료에 적용해 온 경험을 공유하고자 한다. 대상과 방법 초기에 Atlas를 Scepter 카테터에 진입시키지 못하는 기술적 실패를 겪은 뒤 이를 해결하기 위해 문제가 되었던 기구들을 면밀히 관찰하였다. 2018년 3월부터 2019년 12월까지 총 57개의 비파열성 원위내경동맥 동맥류에 대해 코일 색전술을 시행하였고, 이중 25개(23명)의 증례는 BST로 치료하였다. 포함된 증례들의 영상 및 임상 정보는 후향적으로 수집하고 분석하였다. 결과 이 논문에서 소개하는 간단한 팁을 알게 된 이후 Scepter-Atlas 조합의 기술적 성공률은 50%에서 100%로 상승하였다. BST로 치료한 환자군에서 시술 직후에 84%, 추적검사에서 95.8%가 완전하거나 거의 완전한 폐색을 보였고 stent-assisted coil 그룹에서는 각각 96.3%, 88.4%가 시술 직후와 추적검사에서 같은 결과를 보였다. 소수의 환자에서 합병증을 보였지만 임상적으로 문제가 된 증례는 없었다. 결론 Scepter-Atlas 조합을 이용한 BST는 원위내경동맥에 위치한 비파열성 동맥류를 치료하는 데 효과적이고 안전한 방법이 될 수 있다. Scepter는 Atlas를 매개하는 카테터로 충분히 사용될 수 있다.

• 대한간호학회지
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• 제2권1호
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• pp.141-157
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• 1971

The peripheral infection is one of the major causes of maternal death, and although it is preventable through an effective prenatal as well as postnatal care its morbidity is increasing due to bacterial resistant to an effective antibiotics. The primary purpose of this study was to investigate the peripheral morbidity of 949 parturients who were admitted to the Obstetrics and Gynecologic department of Ewha Woman's University Hospital from January 1971 to September 1971. Among the 949 parturients, especially 40 normal parturients were selected (20, control soup was given complete aseptic care during labor and delivery and post delivery: 20, compare group was given the ordinary care practiced during labor and delivery and maternal ward of Ewha Woman's University Hospital) for bacteriologic test on vaginal flora twice, on admission and on complete cervical dilatation of each parturient. The results obtained from this study were as follows; 1. Majority of parturients age were 21 to 35 years old(90.83%), and educational level of 949 parturients was above high school. A large number of parturients socioeconomic level (according to their husbands' job) were moderate. 2, Among the 949 parturients, multipara (55.9%) were a little more than primipara (44. 1%) and 38.84% of parturients had experienced aborition. 3. In deliverty types, normal deliveries (804 cases) were more than cesarean section deliveries (145 cases) The peripheral morbidity after normal deliveries was 0.5%, and cesarean section deliveries, 23.45%. 4. Among 949 parturients incidence of hemorrhage eases (500cc or more bleeding) showed the higher peripheral morbidity (24.86%) than other cases (bleeding less than 500cc, 7.83%). 5. The majority of parturients (81.03%) had teen taking antenatal care, but most of them were taken irregular antenatal care. On the other hand, on admission, the parturients with complication were 30.32%, and their peripheral morbidity showed much higher (7.02%) than those with no complication (2.71%). 6. The incidence of peripheral morbidity in premature ruptured membrane was higher (10.91%) than normal parturienta (1.73%). 7. In the result of aseptic care during labor and delivery and post delivery, the number of cultured bacteria was legs in control group than Compare group (in control group, on admission 17, on complete cervical dilatation 12: in compare group, on admission 21 on complete cervical dilatation 21) . The most common bacteria were Staphylococcus (control group 14 on admission, compare group 16 on admission), and next Streptococcus, E- Coil, Bacillus Subtilis, in order. Also in control group the number. of colony were reduced (43%) more than in Compare group. Transient temperature elevation from 37℃ to 37.4℃ were noted in compare group (50%) than in control group (30%), and there was no one indicated above 38℃. In conclusion, the aseptic care is the test way of preventing peripheral infection as well as decreasing the puerperal morbidity. Therefore the most important nursing care is the aseptic care for each parturient during labor and delivery and peat delivery and also all the instruments must be cleaned and sterilized.

• 대한기계학회논문집B
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• 제36권8호
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• pp.783-789
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• 2012

본 연구에서는 나선형 튜브내의 난류 열전달 및 하중 특성을 수치해석 방법을 이용하여 파악하였다. 열교환기와 같은 공학적 설비에서 관내 열전달을 향상시키기 위해 튜브의 형상을 나선형으로 설계한다. 이에 나선형 튜브내의 열전달 및 난류 특성에 대한 많은 실험적 연구가 이루어 졌으나, 대부분의 연구가 압력 강하 및 열전달 상관관계에 초점이 맞추어 진행되었다. 나선형 튜브내의 유동은 원심력에 의해 튜브 바깥쪽에서는 상대적으로 높은 열전달 및 전단응력이 발생하지만, 안쪽에서는 낮은 열전달 및 전단응력이 발생하게 된다. 따라서 본 연구에서는 튜브의 원주방향으로 발생하는 전단 응력 및 Nusselt 수의 변화를 Reynolds 수와 나선 코일의 지름을 변경하며 정량적으로 살펴보았다. 나선 코일 안쪽에서 국부적인 전단응력과 열전달율이 크게 낮게 특정되었으며, 이는 튜브 재질의 안정성에 영향을 미칠 것으로 판단되었다. 또한 본 연구에서는 마찰계수와 Nusselt 수에 대한 기존 상관관계식을 검증하였으며, 직관에서의 마찰계수와 Nusselt 수의 상관관계식이 나선형 튜브의 형상에도 적용될 수 있음을 관측하였다. 본 연구의 결과는 열교환기나 증기발생기의 안전성 평가를 위해 중요한 데이터로 활용될 수 있을 것이다.

• 지구물리와물리탐사
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• 제23권4호
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• pp.223-229
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• 2020

소형 루프 전자탐사법은 효과적인 물리탐사법으로 다양한 목적으로 천부 조사에 널리 사용되고 있다. 소형 루프 전자탐사에서는 기하학적 수직탐사와 주파수 수직탐사가 적용되고 있으나, 주파수 수직탐사의 경우 그 유효성 대하여 논란이 지속되고 있다. 이 연구에서는 소형 루프 전자탐사에 대한 1차원 모델링을 통하여 기하학적 수직탐사와 주파수 수직탐사의 유효성을 검증하고자 하였다. 수치 실험 결과 기하학적 수직탐사는 효과적으로 지하의 심도에 따른 지하의 정보 해석이 가능한 것으로 나타났다. 반면 주파수 수직탐사는 송수신 간격이 비교적 클 경우, 즉 유도상수가 크다는 조건을 만족해야만 유효한 해석이 가능하며, 그렇지 못할 경우 하부 지층의 정보해석이 불가능한 것으로 나타났다.

• 한국지반신소재학회논문집
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• 제15권3호
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• pp.1-12
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• 2016

본 논문에서는 지열 활용시스템을 지반구조물에 적용시 발생하는 주변 지반에 부과되는 다양한 온도 및 온도변화 사이클이 흙의 역학적 특성에 미치는 영향에 대한 내용을 다루었다. 이를 위해 화강풍화토를 대상으로 다양한 온도변화 조건을 구현하고 이에 따른 흙의 입자구조 및 열전도특성 변화 경향을 고찰하였다. 아울러 다양한 OCR(over consolidation ratio)값을 가지는 시료를 제작하여 내부 온도를 $20^{\circ}C{\sim}70^{\circ}C$까지 변화시키며 온도상승과 가열-냉각 반복작용 횟수에 따른 흙에 미치는 영향을 분석하고자 온도계로 압축셀 내부 온도를 측정하였으며 비배수 실험을 통해 시료에 작용하는 축차응력 및 간극수압을 측정하여 온도변화가 화강풍화토에 미치는 영향을 분석하였다. 그 결과 온도상승과 가열-냉각 반복 작용으로 인해 간극수압이 증가하며 축차응력 또한 감소하는 것으로 관찰되었다.