최근 6년간 연세의료원에서 경험한 한국인 안면골 골절에 대한 임상적 연구

권준호,이충국,이의웅,민우석,윤중호,박형식 大韓顎顔面成形外科學會 1989 Maxillofacial Plastic Reconstructive Surgery Vol.11 No.1

This is a series of continuing research on facial bone fractures of Koreans worked by Dept. of Oral and Maxillofacial surgery, Dental College of Yonsei University, Seoul, Korea, since 1972. The study was based on a series of 630 patients with facial bone fractures treated as in patient at Yonsei Medical Center, Yonsei University, during the period of Jan. 1982 through Dec, 1987. The results obtained are as follows: 1. The ratio of Men to Women was 4.3 : 1, and admissions for facial bone fractures have been increased year after 1984. 2. The age frequency was highest in the third decade(38.3%). and fourth, second, fifth decade in orders. 3. The traffic accident was the most frequent cause of facial bone fractures(51.3%). 4. The most common location of facial bone fractures was the Mandible(35.3%), and Zygoma complex(29.8%), Nasal bone(15.0%), Maxilla(11.0%) were next in order of frequency. 5. In 291 patients of Mandible fractures, 226(77.7%) had fractures only in Mandible and 65(22.3%) had another facial bone fractures. The most frequent fracture site of mandible was the Symphysis(43.0%) and Angle(22.4%), and Simple fracture was the most frequent in type of fracture(66.9%). Intermaxillarty fixatin & Open reduction was major method of treatment(36.9%). 6. In 394 patients of Midface fractures 323(82.0%) had fractures only in Midface and 71(18.0%) had another facial bone fractures. The most frequent site of Midface fractures was zygoma complex & zygomatic arch(42.7%), and Simple fracture was the most common type of fractures. Observation(Maxilla :44.2%, Zygoma :51.0%) and Open Reduction(Maxilla :20.0%. Zygoma :23.5%) were the major method of treatment. 7. The frequency of Nasal bone fracture was about 1/5 of Midface fractures, and Closed Reduction(42.2%) was the major method of treatment. 8. The complication was reported in only 16 patients, and Malunion was the major complication. 9. Head(44.4%), Lower extrimities(14.5%) and Eye(12.3%) were injured commonly with facial bone fractures. 10. The elapsed time from injury to hospital was within 24 hours in 73.8% of patients, however 15.5% of patients arrived the hospital 72 hours after injury.

절삭저항의 동적성분에 의한 표면거칠기의 인프로세스 인식

정의식,권경우 大田産業大學校 1996 한밭대학교 논문집 Vol.13 No.1

The in-process recognition of the cutting state is one of the very important technologies to enhance the reliability of the modern machining process. In this study, the dynamic component of the cutting force, which is closely related to chip breaking (cut-off frequency 80~500 Hz), has been measured to recognize the state of the machined surface in turning process. From the measured results on various cutting conditions, the relationship between the surface roughness and the dynamic component of the cutting force has been investigated, and as a result it can be anticipated that the monitoring of the maximum amplitude in the dynamic component of the cutting force enables the inferiority state of the machined surface to be recognized.

Centerless Feeder 장치의 개발

강형모,권경우,김기길,정의식,허영환 한밭대학교 산업과학기술연구소 1994 논문집 Vol.2 No.-

This paper presents results of the development of centerless feeding system which are applicable to bearing metal processes. As a result, the feeding system can be applied to automatic surface finishing on the bearing metal process such as bush, and has greatly effects on the increase of the prodnctiving and the decrease of the man power an effect on increase the productivity and decrease the man power and effect on increase the productivity and decrease the man power of the bush machining process.

Mechanism of Relaxation of Rat Aorta by Scopoletin : an Active Constituent of Artemisa Capillaris

Kwon, Eui Kwang,Jin, Sang Sik,Choi, Min Ho,Hwang, Kyung Taek,Shim, Jin Chan,Hwang, Il Taek,Han, Jong Hyun 대한동의생리학회,대한동의병리학회 2002 동의생리병리학회지 Vol.16 No.2

In the present work, we examined the mechanism of vasorelaxant effect of scopoletin, an active constituent of Artemisia capillaris on rat thoracic descending aortic rings. Scopoletin induced a concentration-dependent relaxation in rat thoracic descending aortic rings pre-contracted with phenylephrine (EC_50 = 238.94±37.4 μM), while it was less effective in rat thoracic descending aortic rings precontracted with high potassium solution (KCl 30 mM). Vasorelaxation by scopoletin was significantly inhibited after endothelial removal, but recovered at high concentration. Pretreatment of rat thoracic descending aortic rings with N^G-nitro-L-arginine (100 μM), a nitric oxide synthase inhibitor, and atropine (1 μM), a muscarinic receptor antagonist, significantly inhibited scopoletin-induced relaxation of rat thoracic descending aortic rings. Neither indomethacin (3 μM), an inhibitor of cyclooxygenase, nor propranolol (1 μM), a β-adrenoceptor antagonist, modified the effect of scopoletin. The combination of N^G-nitro-L-arginine (100 μM) and miconazole (10 μM), an inhibitor of cytochrome P 450, did not modify the effect of scopoletin, when compared with pretreatment with N^G-nitro-L-arginine (100 μM) alone. Vasorelaxant effect of scopoletin was inverted by pretreatment with diltiazem (10 μM), a Ca^2+-channel blocker, at low concentration, while restored at high concentration. Apamin (K_Ca-channel blocker, 1 μM), 4-aminopyridine (4-AP, K_V-channel blocker, 1 mM), and tetrodotoxin (TTX, Na^+-channel blocker 1 μM ) potentiated the vasorelaxant effect of scopoletin, but glibenclamide (K_ATP-channel blocker, 10 μM), tetraetylammonium (TEA, non-selective K-channel blocker, 10 mM) did not affect the relaxation of scopoletin. Free radical scavengers (TEMPO, catalase, mannitol) did not modify vascular tone. These results suggest that nitric oxide, Ca^2+- channels play a role in endothelium-dependent relaxations to scopoletin in rat aortas, that apamin, 4-AP, TTX but not glibenclamide, TEA potentiated relaxation to scopoletin mediated by these channels, and that free radicals do not concern to the vasorelaxant effect of scopoletin.

간경변 환자의 정맥류 출혈에서 Octreotide의 지혈효과

권운용,정중식,김규석,김성혜,신상도,이중의,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.1

Purpose: This study was conducted to confirm the effects of octreotide in patients with variceal bleeding. Methods: We performed a retrospective analysis of 26 patients with variceal bleeding, who visited the Emergency Center of Seoul National University Hospital from January 1st to June 31st,1996, the control group, and a prospective analysis of 28 patients with variceal bleeding, who visited the Emergency Center of Seoul National University Hospital from March 1st to August 31st, 1999, for the octreotide-infused group. The octreotide-infused group recieved a continuous infusion of octreotide, 25㎍/hr, for 5 days after an initial bolus of 50 ㎍. When active bleeding continued over 1 hour, over 5 pints of packed-RBC were needed for transfusion within 24 hours, or when the systolic blood pressure was under 90mmHg, a ballon tamponade with Sengstaken-Blackemore tube was used. T-test and X2 test were used for statistic at analysis (p<0.05). Results: Forty-one patients were male(octreotide-infused group 22, control group 19) and 13 were female(octreotide-infused group 6, control group 7). The mean age was 55 years(octreotide-infused group 56 years, control group 52 years). There were no significant differences in vital signs, hemoglobin/hematocrit levels, and Child-Pugh's classifications between the octreotide-infused group and the control group initially. There was a significant difference in the rates of early bleeding control within 24 hours(p<0.05), but there were no significant differences in the rates of rebleeding, mortality within 1 week, and use of a balloon tamponade. Conclusion: Variceal bleeding is a serious complication of liver cirrhosis and has a high mortality rate. Octreotide is an effective vasoactive agent for control of early bleeding, Thus, octreotide should be used first before endoscopic definitive therapies, to stabilize the vital signs of patients and to secure a field for endoscopic procedures.

폐암환자에서 늑막조직천자검사에 의하여 전이된 피부사피세포암의 1 예

권오진,송준영,박의수,한대식 대한피부과학회 1981 大韓皮膚科學會誌 Vol.19 No.4

A case of metastatic tumor of the skin is described with literature review. Cutaneous metastases of malignant tumor is rarely seen but lung cancer in male and breast cancer in female are not infrequently reported. This patient, 37 year old male, had lung cancer, had several chest tappings for pleural effusion and a pleural biopsy. 8 months later, skin manifestation of diffuse erythematous sclerotic patches and confluent nodules was noted on pleural biopsy site, right lateral chest wall. Histopathological finding was compatible with metastatic carcinoma. This metastatic skin tumor is considered to be arisen from the lung probably due to pleural biopsy.

Mechanism of Relaxation of Rat Aorta by Scopoletin

Eui Kwang Kwon,Sang Sik Jin,Min Ho Choi,Kyung Taek Hwang,Jin Chan Shim,Il Taek Hwang,Jong Hyun Han 한의병리학회 2002 동의생리병리학회지 Vol.16 No.2

Current Controller Design of a Grid Connected Inverter Using LCL Filter

Kwon-Sik Park,Byuong-Jun Seo,Kwang-Rae Jo,Jin-Yong Heo,Haksoo Kim,Eui-Cheol Nho 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

This Paper proposes a current controller design method of grid connected inverter using an LCL filter without damping method. In case of a grid side current control, it is not necessary for the system to use the damping method if the ratio of the LCL filter resonant frequency to a system sampling frequency is larger than 1/6. However, if the grid impedance is changed, it is not sure whether the system is in the stable region or not. If an LPF (Low Pass Filter) is used in the feedback path of the system, the stable region of the inverter system can be expanded. This paper proposes a new current controller using the LPF in the feedback path. The proposed controller uses the HC (Harmonic Compensator) in order to improve the grid current quality. The validity of the proposed method is verified through simulation.

LCL 필터를 사용하는 계통 연계형 인버터의 넓은 안정 영역을 갖는 새로운 제어 및 설계 기법

박권식(Kwon-Sik Park),서병준(Byung-Jun Seo),김학수(Hak-Soo Kim),노의철(Eui-Cheol Nho) 전력전자학회 2018 전력전자학회 논문지 Vol.23 No.6

발열이 있는 호중구 감소증 환자에서의 위험도 예측인자

정중식,권운용,김규석,임용수,이중의,서길준,윤여규 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Most febrile neutropenic patients are treated in an aggressive manner. However, identification of low-risk patients may enable clinicians to administer risk-based treatment. The object of this study is to certify the factors associated with increased risk at the time of visiting the emergency department. Methods: This is a retrospective study. We reviewed the medical records of 101 febrile neutropenic patients who had visited the emergency department of Seoul National University Hospital from January 1998 to August 1999. We assumed 22 risk prediction factors that could be assessed at admission to the emergency department and 5 factors that could be assessed during treatment course. To find independent risk-prediction factors, we analyzed these factors respectively by using multiple regression analysis. Results: Tachycardia(aOR=136.5), altered mentality(aOR=28.8), decreased renal function(aOR=20.1), and significant comorbidity(aOR=17,2) are the independent factors associated with higher mortality. Altered mentality(aOR=31.6) and decreased renal function(CCr < 75㎖/min, aOR=5.4) are those associated with a higher incidence of septic shock. Independent factors associated with persistent(more than 3 days) fever are the early(within 10 days) onset of fever after last chemotherapy(aOR=8.8) and the existence of new pulmonary infiltrates on a simple chest X-ray(aOR=4.3). Conclusion: The stability of vital signs, the change of mentality, the renal function, the existence of significant comorbidity, the existence of new pulmonary infiltrates, and the rate of neutropenia are clinically useful risk-prediction factors in febrile neutropenia at the time of visiting the emergency department.