폐쇄성 수면무호흡 환자의 상기도 형태의 특징과 압력강하에 관한 3차원 전산유체역학해석

모성서,안형택,이정선,정유삼,문윤식,배응권,성상진 대한치과교정학회 2010 대한치과교정학회지 Vol.40 No.2

폐쇄성 수면무호흡(obstructive sleep apnea, OSA)은 수면 중에 반복적으로 상기도의 완전폐쇄나 부분폐쇄가 일어나는 질환으로서 흡기된 공기는 반드시 상기도라는 연조직 관(tube) 구조를 통과해야 하므로 상기도의 폐쇄경향은 관의 형태 및 관을 통과하는 공기의 유체역학적 특성에 따라서도 큰 영향을 받을 수 있다. 본 연구에서는 OSA 환자 3인의 치료 전 상기도 CT 이미지를 이용하여 개별화된 3차원 유한요소모델 A, B, C를 제작하고, 비공 당 170, 200, 230 ml/s의 흡기유량에 대하여 3차원 전산유체역학 해석을 시행하였다. 상기도의 유속, 음압 그리고 압력강하를 측정한 결과 관찰된 3개의 모델에서 모두 단면적이 가장 작은 부위에서 유속이 증가하였고, 음압이 크게 나타났다. 기도의 형태는 구개인두와 구인두 부위에서 좁아지는 형태를 가지며, 최소 단면적 영역과 하인두 단면적의 차이가 클수록 유속과 음압의 변화가 크게 나타났다. 비강 부위의 최고 압력과 최소 단면적 영역의 최저 압력의 차이를 의미하는 압력강하는 상기도 저항을 종합적으로 판단할 수 있는 유용한 지표이며, 유량에 따라 증가하였다. Objective: Obstructive sleep apnea (OSA) is a common disorder which is characterized by a recurrence of entire or partial collapse of the pharyngeal airway during sleep. A given tidal volume must traverse the soft tissue tube structure of the upper airway, so the tendency for airway obstruction is influenced by the geometries of the duct and characteristics of the airflow in respect to fluid dynamics. Methods: Individualized 3D FEA models were reconstructed from pretreatment computerized tomogram images of three patients with obstructive sleep apnea. 3D computational fluid dynamics analysis was used to observe the effect of airway geometry on the flow velocity, negative pressure and pressure drop in the upper airway at an inspiration flow rate of 170, 200, and 230 ml/s per nostril. Results: In all 3 models, large airflow velocity and negative pressure were observed around the section of minimum area (SMA), the region which narrows around the velopharynx and oropharynx. The bigger the Out-A (outlet area)/ SMA-A (SMA area) ratio, the greater was the change in airflow velocity and negative pressure. Conclusions: Pressure drop meaning the difference between highest pressure at nostril and lowest pressure at SMA, is a good indicator for upper airway resistance which increased more as the airflow volume was increased.

흰쥐에 Vitamin Antioxidants 투여가 Lipid Peroxidation에 미치는 영향

함윤애,홍영숙,성낙응 梨花女子大學校 醫科大學 醫科學硏究所 1982 EMJ (Ewha medical journal) Vol.5 No.3

We observed the effect of the administration of vitamin A,C and E with β-naphthoflavone and piperonyl butoxide on cytochrome P-450 level and lipid peroxidation in rats liver. The level of hepatic cytochrome P-450 decreased after vitamin A,C and E was administration. In contrast, β-naphthoflavone, when administered with vitamin A,C and E, the increase of cytochrome P-450 was prevented. Lipid peroxidation was decreased after vitamin A, C, and E was administer-ed. Moreover when β-naphthoflavone was administered together with vitamin A, C and E lipid peroxidation was not increased. When piperonyl butoxide was administered together with vitamin A,C and E, both cytochrome P-450 and lipid peroxidation were decreased. These results indicate that vitamin antioxidants can prevent lipid peroxidation by a cytochrome P-450 dependent terminal oxidase system in rat liver microsomes.

제4형 가족성 고중성지방혈증 임산부에서 발생한 급성 췌장염 1례

박관응,윤채중,김영학,진영기,윤성호,권용은,김태원,박찬국,김만우 朝鮮大學校 附設 醫學硏究所 1997 The Medical Journal of Chosun University Vol.22 No.2

Plasma levels of cholesterol (TC) and triglyceride(TG) physiologically increase during pregnancy. The lipid increment is 23-53% above the pregravidic level for TC and 2- to 3-fold of the prepregnancy level for TG. If the TC and TG are higher than normal values in pregnancy, the patient must be carefully monitored. Acute pancreatitis is the main consequence of hyperlipidemia and occurs either during pregnancy, in the third trimester, or in the puerperium. Mortality is high both for the mother (21%) and the fetus (20%). We report a case of 28 year-old pregnant woman at 29 weeks gestation with hypercholesterolemia (TC = 357 ㎎/dl) and severe hypertriglyceridemia (TG = 1300 ㎎/dl). The patient was admitted to the hospital because of severe epigastric pain, nausea and vomiting. Total serum cholesterol was increased and trigyleride was markedly increased. The electroporesis pattern of serum lipoprotein showed increase in pre-beta lipoprotein fraction, suggesting IV hypertriglyceridemia pattern. According to a review of the literature, the incidence of pancreatitis during pregnancy is 1 in 1000 to 3000 pregnancies. Severe hypertriglyceridemia in pregnancy should be treated with a careful restriction of calories and fat: for preventing acute pancreatitis, hospitalization for intravenous fluid therapy and plasma exchange must be required.

직장암 수술 후 국소재발과 예후

김태윤,백무준,김성용,신응진,박내경,이문수,김창호,송옥평 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

Locally recurrent rectal cancer is a difficult clinical problem. Local recurrence following treatment for rectal cancer is a major cause of morbidity and mortality. The reported range of local recurrence rates following surgical treatment for rectal cancer has varied from 4% to 50%. We retrospectively reviewed the charts of 142 rectal cancer patients from January 1991 to December 1999. Analysis of patients factors included age, gender, type of surgery, and adjuvant therapy. Tumors were assessed for level, stage, and grade. Local recurrence and distant metastases were also documented. Variables influencing local recurrence in this group were identified and disease-free survival is determined. Of the 142 patients(74 males, 68 females; mean age 62.6 years), 137 consecutive patients operated on for rectal cancer and followed up to December 2000 (range 23-118months) were analyzed. Local recurrence rate was 18.3%. Age and sex of patients, type of surgery, location of tumor in the rectum, size, morphology and grading of the tumor were all unrelated to the event under investigation. At Cox regression, the Dukes stage and the postoperative radiotherapy were the only independent prognostic factors for local recurrence, and Dukes stage (Hazard ratio=2.89, p<0.001) and local recurrence (Hazard ratio=3.31, p<0.01) were the only independent factors associated with improved survival.

Ruled Surface로 형성된 임펠러 블레이드 전용 CAD/CAM 시스템 개발 Ⅱ : 5-축 가공에 관한 연구 A Study on the 5-Axis Machining

조현덕,정대일,윤문철,최두선,신보성,이응숙,董玉革 한국공작기계학회 2002 한국생산제조학회지 Vol.11 No.3

This study is continuous with the study 1 (A Study on the Modeling) and the sample impeller of this study is defined by the modeling process of the exclusive CAD/CAM system developed in the study I. And, this study describes a method for the 5-axis machining of impeller blades formed by ruled surface. Therefore, the exclusive CAD/CAM system is the software for modeling and machining of impeller blades. By using the machining method suggested in this study, we could manufacture impeller blades on 5-axis CNC machining center and the machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades.

Ruled Surface로 형성된 임펠러 블레이드의 5-축 가공에 관한 연구

정대일,조현덕,윤문철,최두선,신보성,이응숙 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.

Ruled Surface로 형성된 임펠러 블레이드 전용 CAD/CAM 시스템 개발 Ⅰ : 모델링에 관한 연구 A Study on the Modeling

조현덕,정대일,윤문철,최두선,신보성,이응숙,董玉革 한국공작기계학회 2001 한국생산제조학회지 Vol.10 No.6

We have developed the exclusive CAD/CAM system for the machining of impeller blades. This study is about the modeling method for the effective machining of impeller blades formed by ruled surface. As the impeller is consisted of boss part and blade part, the boss is modeled by rotational surface of hub curve on z-axis and the blade is described by ruled-surfaces between hub curve and shroud curve. This modeling process can be carried out on the software developed in this study. And, the developed software can describe the impeller as a solid model through interface with Solid-Works software. The developed software containing the interface method proposed in this study was very effective for impeller modeling.

MOCVD법에 의해 제조된 Fe₂O₃-TiO₂계 산화물 박막의 내식특성에 관한 연구

李在鉉,杉本克久,許聖康,尹在弘,金顯洙,邊應善 國立 昌原大學校 産業技術硏究所 1998 産技硏論文集 Vol.12 No.-

Fe₂O₃-TiO₂artificial passive films were formed at the temperatures of 200-350℃ by low pressure MOCVD technique. The relationship between the formation temperature and corrosion resistance of the Fe₂O₃-TiO₂films was examined in acid solutions. Fe₂O₃-TiO₂films deposited above 300℃ were crystalline and the films deposited below 250℃ were amorphous. The dissolution rate of the Fe₂O₃-TiO₂films deposited at 200 and 250℃ decreased with increasing the formation temperature in 5 M HCl, but the films deposited at 300 and 350℃ hardly dissolved in the solution. The films deposited at 200 and 350℃ easily dissolved at cathodic potentials in 1 M H₂SO₄and HCl owing to te selective reduction of iron oxide components in the films. But, the selective reduction in the films deposited at 300 and 350℃ was suppressed. The Fe₂O₃-TiO₂films deposited above 300℃ have higher corrosion resistance than that of the films deposited below 250℃, because the former have high crystallinity and cotain high chemical resistant oxides.

세포질내 정자주입법(ICSI)에 있어서 정자흡입 및 난자내 주입방법에 관한 연구

이택후,김항진,송건호,김대근,전상식,박윤규,서태광,전병균,류은경,이은숙,문진수,김광철 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Study on Method of Sperm Aspiration and Injection into an Oocyte in Intracytoplasmic Sperm Injection(ICSI) Immobilization of spermatozoa prior to intracytoplasmic sperm iniection(ICSI) sometimes results in crooked tail and this makes it difficult to aspirate sperm into an injection pipette tail first. Head-first sperm aspiration into an injection pipette avoid this problem due to the bigger size of the sperm head. The effect of head or tail-first sperm injection into an oocyte on fertilization cleavage, percentage of grade I embryos and development to blastocyst stage in ICSI program has been studied. A single living immobilized spermatozoa from oligoasthenozoospermic patient was injected into an oocyte head-first or tail-first according to the treatment. Eighteen hours after microinjection, oocytes ware inspected for survival and fertilization Fertilized oocytes with two pronuclei were cultured in 30μl drop of mHTF supplemented with 10% heat-inactivated follicular fluid(FF) at 37℃. On day 2. embryo transfer was performed with cleaved embryos. The remaining 2-8 cell stage embryos were co-cultured with BRL cells in mHTF + 10% FF for 72 hours and the developmental stage was observed. The data were analyzed by Analysis of Variance. A total of 164 oocytes from 36 cycles were assigned to earth treatment and ICSI was performed(88 head-first, tail-first). The rates of normal fertilization were 81.8% and 76.3% for head-first and tail-first, respectively. Of the fertilized oocytes, the percentage of cleaved embryos and the percentage of grade 1 embryo among cleaved embryos were 88.9% and 68.8%, 93.1% and 74.1% for head-first and tail-first, respectively. Of the 2-8 cell embryos cultured, 44.4%(16/36) and 50.0%(10/20) for head first and tail first, respectively developed to blastocyst stage. There were no differences in fertilization, cleavage, rates of grade 1 embryos, and development to blastocyst stage. In conclusion, head-first or tail-first sperm injection into an oocyte in ICSI program does not affect fertilization and subsequent embryo development to blastocyst stage in vitro.

Fat Tissue Infiltration into the Pancreas Parenchyme and Its Effect on the Result of Surgery

Sang Ho Yoon,Eung-Ho Cho,Sang Bum Kim,Sun-Hoo Park 한국간담췌외과학회 2011 한국간담췌외과학회지 Vol.15 No.2

Purpose: In Korea, there are few reports regarding the infiltration of fat tissue in pancreatic parenchyma in surgically resected organs. It is necessary to ascertain the correlation between the presence of fat tissue in the resection margin of the pancreas and the surgery outcome. Methods: Fifty four patients who underwent pancreatic resection from Jan. 2007 to Nov. 2008 were enrolled in this study. Pathologic examination was performed to determine the presence of fat tissue in resected pancreatic parenchyma. Statistical correlation between the presence of fat tissue with clinical parameters and postoperative complication rates was analyzed. Results: Among the specimens of all fifty four patients, fat tissue was found in 32 specimens of patients (59.3%). Female gender and patients whose body mass index exceeded 24 kg/m2 were statistically correlated with the presence of the fat tissue in pancreatic parenchyma. There was no statistical relationship between infiltration of fat tissue with postoperative complications. Conclusion: This study may serve as the base data for study in radiological imaging in detecting pancreatic tissue. A further larger scaled study is needed to validate the result of this study.