• Clinical and Experimental Pediatrics
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• 제45권3호
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• pp.383-389
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• 2002

저자들은 미숙아에서 청색증과 무호흡증으로 입원 치료 하던 중 저칼슘혈증으로 인한 경련이 나타난 환아에게서 흉부 X선 사진과 MRI상 흉선을 관찰할 수 없으면서 T 세포수의 감소와 부갑상선 홀몬수치 감소를 나타내고 소악증, 어구, 부리모양의 코 등의 안면 기형과 합지증, 코 역류증, 폐쇄성 수면 무호흡증, 구개 범인두 부전증 등의 증상을 보이며 염색체 22q11 극소결실이 FISH검사에서 확진된 부분형 DiGeorge 증후군 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• Clinical and Experimental Pediatrics
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• 제52권10호
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• pp.1136-1139
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• 2009

목 적:신생아, 특히 미숙아에서 재태기간의 정확한 측정은 환자의 상태와 질병을 이해하여 치료하고 예후를 예상하는데 필수적이다. 이에 저자들은 신생아 뇌 초음파 검사시 최소한의 시간과 기구의 추가 사용으로 간편하게 정확한 재태기간을 추정할 수 있는 방법을 연구하였다. 방 법:일반적인 뇌 초음파 검사를 시행한 후 5-12 Mhz의 고해상도 선형 탐촉자를 사용하여 대천문을 통하여 관상면의 영상을 얻었고 여기에서 대뇌반구의 깊이와 뇌량의 두께 및 대상고랑의 깊이를 측정하여 재태기간과의 상관관계을 구하였다. 결 과:대뇌반구의 깊이, 뇌량의 두께 및 대상고랑의 깊이 중 재태기간과 가장 상관관계가 높은 측정치는 대상고랑의 깊이로 Pearson 상관계수 0.878을 보였다(P=0.000). 또한 대상고랑의 깊이가 0.55 cm 이상인 경우 단 두 례를 제외하고 모두 재태기간이 37주 이상이었고 대상고랑의 깊이가 0.35 cm 미만인 경우는 모두 34주 미만이었다. 결 론:고해상도 뇌 초음파 검사를 통해 측정된 대상고랑의 깊이는 신생아의 정확한 재태기간 측정에 유용하게 이용될 수 있다. 그러나 보다 더 많은 수의 신생아를 대상으로 한 대규모 연구가 필요할 것으로 생각된다.

• Journal of Astronomy and Space Sciences
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• 제27권2호
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• pp.89-96
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• 2010

BVR CCD observations of GW Cep were made on 15 nights in November through December 2008 with a 1-m reflector at the Jincheon station of the Chungbuk National University Observatory. Nineteen new times of minimum lights for GW Cep were determined and added to a collection of all other times of minima available to us. These data were then intensively analyzed, by reference to an O-C diagram, to deduce the general form of period variation for GW Cep. It was found that the O-C diagram could be interpreted as presenting two different forms of period change: an exclusively quasi-sinusoidal change with a period of 32.6 years and an eccentricity of 0.10; and a quasi-sinusoidal change with a period of 46.2 years and an eccentricity of 0.36 superposed on an upward parabola. Although a final conclusion is somewhat premature at present, the latter seems more plausible because late-type contact binaries allow an inter-exchange of both energy and mass between the component stars. The quasi-sinusoidal characteristics were interpreted in terms of a light-time effect due to an unseen tertiary component. The minimum masses of the tertiary component for both cases were calculated to be nearly the same as the $0.23-0.26M\;{\odot}$-ranges which is hardly detectable in a light curve synthesis. The upward parabolic O-C diagram corresponding to a secular period increase of about $4.12{\times}10^{-8}\;d/yr$ was interpreted as mass being transferred from the lesser to more massive component. The transfer rate for a conservative case was calculated to be about $2.66\;{\times}\;10^{-8}\;M_{\odot}/yr$ which is compatible with other W UMa-type contact binaries.

• 한국산학기술학회논문지
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• 제14권8호
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• pp.3602-3610
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• 2013

현대 무기체계는 첨단화와 복잡성의 증가로 시스템개발 실패 사례가 빈번하게 발생하고 있다. 사례분석결과 원인은 원래의 시스템 운용개념을 충족시키지 못하거나 미성숙 기술의 적용 등으로 파악되었다. 이에 방위사업청에서는 무기체계개발시 핵심요구성능으로서 작전운용성능의 충족을 요구하고 있다. 한편 시스템개발시의 위험관리 방법중의 하나로서 기술성숙도 평가가 사용되어 왔는데, 이것은 개별기술에 대한 평가방법이므로, 시스템 수준에서의 기술간 통합에 대해서는 미흡하다. 이를 보완하기 위해 시스템 성숙도 평가 모델이 제시되었고, 이와는 별도로 시스템개발의 난이도의 도입을 통한 리스크 관리 모델이 제시되었다. 하지만 기술간 통합의 효과와 시스템개발 난이도를 동시에 고려한 모델은 제시되지 않았다. 또한 무기체계개발의 궁극적인 목표인 작전운용성능 충족의 관점에서 도출된 평가모델은 제시되지 못하였다. 따라서 본 연구에서는 무기체계개발에서 작전운용성능을 충족시키면서 리스크 관리를 수행하기 위한 방법으로, 요소기술간 통합과 시스템개발 난이도를 동시에 고려한 시스템 성숙도 평가 모델을 구축하였다. 또한 무기체계 연구개발단계에서 개선된 시스템 성숙도 평가모델을 적용할 수 있는 방법을 제시하였다.

• Nutrition Research and Practice
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• 제1권2호
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

• Journal of Korean Neurosurgical Society
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• 제29권9호
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• pp.1188-1194
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• 2000

Objective : Internal carotid-posterior communicating artery(IC-PC) aneurysms can be clipped easily without any special preparations. Occasionally, however, it is difficult to clip the low-lying IC-PC aneurysms without some kinds of additional procedures. Clinical Material and Methods : We experienced four cases of low-lying IC-PC aneurysms, which the intradural anterior clinoidectomy and/or anterior petroclinoid fold(APF) resection was essential to expose the proximal side of the aneurysmal neck and/or proximal control. One patient harbored two low-lying IC-PC aneurysms bilaterally. The patients were divided into two groups according to the necessity of anterior clinoidectomy : Group I(n=4) that needed an intradural clinoidectomy and/or APF resection and Group II(n=29) that had IC-PC aneurysms, easily clipped without any special preparation. Also, various radiometric parameters were measured through the preoperative angiograms. Results : The incidence of such aneurysms was 12% among a total of thirty-three surgically treated IC-PC aneurysms during lasr 3 years. Among four cases, three cases presented with subarachnoid hemorrhage and all aneurysmal sac projected to postero-inferior direction. In our study, We initially considered the necessity of intraoperative anterior clinoid process(ACP) removal and/or resection of APF in cases of shorter distance less than 5.6mm between the proximal aneurysmal sac and tip of the ACP(p<0.001), and the proximal portion of aneurysmal neck has located below the interclinoid line(p=0.001). Conclusion : Through a careful preoperative evaluation, some radiometric parameters can be used to determine whether the ACP should be removed in clipping of the low-lying IC-PC aneurysms. Unlike to total removal of the ACP, the intradural partial anterior clinolidectomy and/or APF resection, which are more familiar to surgeons, reduce the risks of the premature rupture, operative time, and also contribute a more precise clip placement with proximal control than the extradural clinoidectomy.

• Nutrition Research and Practice
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• 제14권3호
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• pp.230-241
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• 2020

BACKGROUND/OBJECTIVES: Inadequate nutrition in infants and young children affects physical growth and neurocognitive development. Therefore, early nutritional intervention is important to promote catch-up growth in young children with faltering growth. The aim of this study was to evaluate the effect of nutritional supplementation with a pediatric concentrated and balanced nutritional supplement formula on promoting growth and improving nutritional status in children with nonorganic faltering growth. SUBJECTS/METHODS: Children aged 12-36 months whose body weight-for-age was < 5^th percentile on the Korean Growth Charts were enrolled. Children born premature or having organic diseases were excluded. Children were instructed to consume 400 mL of formula per day in addition to their regular diet for 6 months. Pediatricians and dietitians educated the parents and examined the subjects every 2 months. Anthropometric parameters were measured at baseline and at 2, 4, and 6 months, and laboratory tests were done at baseline and 6 months. The good consumption group included children who consumed ≥ 60% of the recommended dose of formula. RESULTS: Total 82 children completed the 6-month intervention. At baseline, there were no significant differences in all variables between the good consumption and poor consumption groups. Weight and weight z-scores were significantly improved in the good consumption group compared to the poor consumption group at the end of the intervention (P = 0.009, respectively). The good consumption group showed a significant trend for gaining weight (P < 0.05) and weight z-score (P < 0.05) compared to the poor consumption group during 6 months of formula intake. The concentration of blood urea nitrogen was significantly increased in the good consumption group (P = 0.001). CONCLUSIONS: Nutritional supplementation with a concentrated and balanced pediatric nutritional formula along with dietary education might be an effective approach to promote catch-up growth in children with nonorganic faltering growth.

• 대한화장품학회지
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• 제40권4호
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• pp.413-421
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• 2014

코르티코트로핀분비인자(Corticotropin-releasing factor)는 스트레스 반응에 관여하는 호르몬으로, 최근 스트레스가 탈모와 같은 피부질환에 영향을 미친다는 보고들이 많아지고 있다. 보고에 따르면, 사람 모낭 배양에서 코르티코트로핀분비인자는 길이생장을 억제하며, 모낭의 조기퇴행을 유도하고 모기질각질형성세포(hair matrix keratinocyte)의 세포사멸을 촉진시킨다. 본 연구에서는 코르티코트로핀분비인자가 모발성장과 모주기조절에 핵심적으로 역할하는 모유두세포에 미치는 영향에 대해 알아보고자 했다. 시상하부-뇌하수체-부신축의 주요 스트레스호르몬들인 코르티코트로핀분비인자, 부신피질자극호르몬, 그리고 코르티솔을 사람 모유두세포에 처리하였다. 흥미롭게도, 코르티코트로핀분비인자가 모발성장과 관련된 사이토카인(KGF, Wnt5a, $TGF{\beta}-2$, Nexin)의 발현을 변화시키는 것을 관찰하였으며, 세포 내 cAMP의 수준을 증가시켰고, 수용체의 발현을 억제시켰다. 이러한 변화는 수용체의 길항제인 antalarmin과 astressin2B, 또는 PKA 억제제의 전처리로 인해 막을 수 있었다. 코르티코트로핀분비인자는 cAMP/PKA경로를 통해 POMC의 발현을 유도하는데, 사람 모유두세포에서도 이 호르몬의 처리가 POMC mRNA의 발현을 증가시키는 것을 확인할 수 있었으나 부신피질자극호르몬의 변화는 western blot으로는 확인할 수 없었다. 이러한 결과들을 바탕으로, 코르티코트로핀분비인자가 그 수용체를 통해 사람 모유두세포 내 모발성장 관련 사이토카인의 발현을 조절함을 확인하였으며, 이는 코르티코트로핀분비인자의 수용체 길항제가 스트레스성 탈모환자를 위한 치료제 혹은 화장품 소재로써 활용될 수 있음을 보여준다.

• 한국물환경학회지
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• 제32권1호
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• pp.36-45
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• 2016

강우유출수 오염물 제거를 위한 침투시설에서 모래필터가 널리 적용된다. 공극폐색, 즉 필터 여재에 부유물이 침전되면 침투능이 저하되어 침투시설의 기능과 수명이 단축된다. 침투시설의 효과적인 설계 및 유지관리를 위해 모래필터 내의 물리적, 화학적, 생물학적 폐색 특성을 알아야 한다. 이 논문에서는 여재 깊이 변화에 따른 모래필터의 물리적 폐색 특성변화를 검토하였다. 연직방향, 변수위 침투조건에서 시행한 실험실 컬럼 침투실험으로부터 이들 특성변화를 관찰하였다. 실험결과, 폐색현상의 결과로서 필터의 여재 깊이가 증가할수록 부유물 제거효율이 증가하지만, 필터의 성능유지 기간은 감소하는 현상을 보였다. 모든 여재 깊이 조건에서 여재 깊이의 상부 15%에서 100~250 μm의 부유물이 침전되면서 폐색현상이 발현하는 조기폐색이 발생했다. 결과에 근거하여 침투시설의 첫번째 유지관리 시침투능 확보를 위해 여재깊이의 상부 15%를 긁어내는 방법을 제안할 수 있었다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권4호
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• pp.324-331
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• 2001

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device. Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted. Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was $9.40{\pm}0.3mm$ in 3-day latency group, $9.35{\pm}0.1mm$ in 5-day latency group, and $8.85{\pm}0.1mm$ in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.