• 제목/요약/키워드: Common-cause failure

검색결과 243건 처리시간 0.028초

유기인제 중독에서 콜린성 위기 회복후 급성 호흡부전을 보인 Intermediate Syndrome 2예 (Two Cases of Respiratory Failure After Recovery of Cholinergic Crisis in Organophosphate Poisoning: The Intermediate Syndrome)

  • 조대경;이성은;백재중;정연태;정근호
    • Tuberculosis and Respiratory Diseases
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    • 제47권2호
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    • pp.247-254
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    • 1999
  • 급성 유기인제 중독에서의 주사망 원인인 호흡부전은 급성 콜린성 위기시에 발생하지만 콜린성 위기에서 회복된 후 콜린양 증상의 동반없이 24-96시간에 근위부 사지근육, 경부굴근 및 운동뇌신경 분포근육의 무력증과 함께 호흡부전이 발생하기도 한다. 이를 IMS이라 하며 조기에 인지하고 적절히 치료하지 못했을 때 호흡근 마비로 사망 할 수 있어 모든 유기인제 중독환자를 최소 5일 이상 병원내에서 무호흡보조 치료에 대한 준비상태를 갖추고 근접관찰 하여야 한다. 저자들은 유기인제 중독에서 콜린성 위기 회복후 호흡부전을 유발한 IMS 2 례를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

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강우에 의한 사면붕괴에 관한 2차원 수치모의 (Two-dimensional Numerical Simulation of Rainfall-induced Slope Failure)

  • 램 크리쉬나 레그미;정관수;이기하
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2012년도 학술발표회
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    • pp.34-34
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    • 2012
  • Heavy storms rainfall has caused many landslides and slope failures especially in the mountainous area of the world. Landslides and slope failures are common geologic hazards and posed serious threats and globally cause billions in monetary losses and thousands of casualies each year so that studies on slope stability and its failure mechanism under rainfall are being increasing attention of these days. Rainfall-induced slope failures are generally caused by the rise in ground water level, and increase in pore water pressures and seepage forces during periods of intense rainfall. The effective stress in the soil will be decreased due to the increased pore pressure, which thus reduces the soil shear strength, eventually resulting in slope failure. During the rainfall, a wetting front goes downward into the slope, resulting in a gradual increase of the water content and a decrease of the negative pore-water pressure. This negative pore-water pressure is referred to as matric suction when referenced to the pore air pressure that contributes to the stability of unsaturated soil slopes. Therefore, the importance is the study of saturated unsaturated soil behaviors in evaluation of slope stability under heavy rainfall condition. In an actual field, a series of failures may occur in a slope due to a rainfall event. So, this study attempts to develop a numerical model to investigate this failure mechanism. A two-dimensional seepage flow model coupled with a one-dimensional surface flow and erosion/deposition model is used for seepage analysis. It is necessary to identify either there is surface runoff produced or not in a soil slope during a rainfall event, while analyzing the seepage and stability of such slopes. Runoff produced by rainfall may result erosion/deposition process on the surface of the slope. The depth of runoff has vital role in the seepage process within the soil domain so that surface flow and erosion/deposition model computes the surface water head of the runoff produced by the rainfall, and erosion/deposition on the surface of the model slope. Pore water pressure and moisture content data obtained by the seepage flow model are then used to analyze the stability of the slope. Spencer method of slope stability analysis is incorporated into dynamic programming to locate the critical slip surface of a general slope.

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A STUDY ON SURFACE ALTERATION OF IMPLANT SCREWS AFTER FUNCTION

  • Han, Myung-Ju;Chung, Chae-Heon;Choi, Han-Cheol
    • 대한치과보철학회지
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    • 제40권3호
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    • pp.275-286
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    • 2002
  • Statement of problem. Surface alteration of the implant screws after function may be associated with mechanical failure. Theses metal fatigue appears to be the most common cause of structural failure. Purpose. The purpose of this study was to evaluate surface alteration of the implant screws after function through the examination of used and unused implant screws in SEM(scanning electron microscope). Materials and methods. In this study, abutment screws(Steri-oss, 3i), gold retaining screw(3i) and titanium retaining screw(3i) were retrieved from patients. New, unused abutment and retaining screws were prepared for control group. Each of the old, used screws was retrieved with a screwdriver. And retrieved implant complex of Steri-oss system was prepared for this study. Then, SEM investigation and EDS analysis of abutment and retaining screws were performed. And SEM investigation of cross-sectioned sample of retrieved implant complex was performed. Results. In the case of new, unused implant screws, as maunfactured circumferential grooves are regularly examined and screw thread are sharply remained. Before ultrasonic cleansing of old, used implant screw, a lot of accumulation and corrosion products were existed. After ultrasonic cleansing of old, used implant screws, circumferential grooves as examined before function were randomly deepened and scratches increased. Also, dull screw thread was examined. More surface alterations after function were examined in titanium screw than gold screw. And more surface alteration was examined when retrieved with driver than retrieved without driver. Conclusions. These surface alteration after function may result in the screw instability. Regularly cleansing and exchange of screws was recommended. We recommend the use of gold screw rather than titanium screw, and careful manipulation of the driver.

심실 중격결손증에 대한 임상적 고찰 [70예] (Clinical Evaluation of 70 Cases of Ventricular Septal Defect in Korea)

  • 조규석
    • Journal of Chest Surgery
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    • 제11권1호
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    • pp.46-57
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    • 1978
  • Ventricular septal defect was the most common congenital Heart disease admitted to the Severance Hospital from December, 1963 to June 30. 1977. A total of 1,811 cardiac patients received cardiac catheterization in the CardiacCenter of Yonsei University Medical College. Out of the 1,811 cardiac patients, 791 cases had congenital heart disease and of these 172 cases had ventricular septal defect. This amounted to 21.7% of all those with congenital heart disease. Seventy cases of ventricular septal defect operated on in the chest surgery department are presented. Of these 70 cases of ventricular septal defect, 54 cases were male and 16 cases were female. Their ages ranged from 4/12 months to 32 years. The ratio of systolic pressure of the main pulmonary to systemic artery [Pp/Ps] for 29 of the 59 isolated ventricular septal defects was below 45 percent. Pp/Ps ratio for 19 of the 59 isolated ventricular septal defects was 75 percent. The patients were mostly below fifteen years of age. Out of 64 cases, there were 36 cases of type II defects, 20 cases of type I, 4 cases of type III , 2 cases of type IV, one case of both type II and one case of left ventricular right atrial communication. The anomalies associated with ventricular septal defect were 13 in all; 4 cases of aortic insufficiency, 3 cases of ruptured aneurysm of the sortie sinus of valsalva, 2 cases of ruptured aneurysm of the sortie sinus of valsalva with aortic insufficiency, 2 cases of patent ductus arteriosus, one case of ruptured aneurysm of the aortic sinus of valsalva with atrial septal defect [secundum type] and one case of atrial septal defect [secundum type]. Overall mortality was 8.6 percent. The mortality in pulmonary artery banding was 37.5 percent. The causes of mortality were in one case congestive heart failure, in one case asphyxia and in one case respiratory insufficiency. Tile mortality in ventricular septal defect associated with pulmonary hypertension was 7.1 percent. The cause of mortality was in one case low cardiac output syndrome. There was no mortality in the ventricular septal defects without pulmonary hypertension and mortality in the ventricular septal defect. In ventricular septal defect associated with combined anomalies, the causes mortality were in one case respiratory insufficiency and in one case congestive heart failure.

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광배근 유리 피판술을 이용한 사지 재건술 (Reconstruction of the Limb Using Latissimus Dorsi Free Flap)

  • 김주성;정준모;백구현;정문상
    • Archives of Reconstructive Microsurgery
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    • 제6권1호
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    • pp.56-62
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    • 1997
  • Latissimus dorsi(LD) muscle is the largest transplantable block of vascularized tissue. Since LD free flap was introduced in 1970's, this flap has been widely used for the reconstruction of large soft tissue defect of the limb. From 1981 to 1996, we had experienced 37 cases of LD free flap. Serratus anterior muscle was combined with LD in three of them whose defects were very large. The average age of the patients was 31 years(range : 4-74 years), and thirty one patients were male. Trauma was cause of the defect in every case. For the recipient sites, the foot and ankle was the most common(22 cases); and the knee and lower leg(11 cases), the elbow and forearm(2 cases), the hand(2 cases) were the next. The duration of follow-up was averaged as 16 months(range: 6 months-12 years). Thirty one cases(84%) out of 37 were successful transplantations. In one case the failure of the flap was due to heart attack and subsequent death of the patient. One failure was caused by sudden violent seizure of the patient who had organic brain damage. Immediate reexploration of the flap was performed in 4 patients, and the flap survived in three of them. There was one necrosis of the grafted split-thickness skin on the survived LD flap. LD free flap was considered as one of the good methods, for the reconstruction of the large soft tissue defect of the limb.

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인공 심장판막의 재치환술 -수술 위험인자와 수술 결과의 분석- (Reoperation of Prosthetic Heart Valve; An Analysis of Operative Risks and Late Results)

  • 김관민
    • Journal of Chest Surgery
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    • 제28권1호
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    • pp.23-30
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    • 1995
  • From January 1985 to December 1992, of 1257 patients who underwent a heart valve replacement 210 [16.8% underwent reoperation on prosthetic heart valves, and 6 of them had a second valve reoperation. The indications for reoperation were structural deterioration [176 cases, 81.5% , prosthetic valve endocarditis [25 cases, 11.6% , paravalvular leak [12 cases, 5.6% , valve thrombosis [2 cases, 0.9% and ascending aortic aneurysm [1 case, 0.4% . Prosthetic valve failure developed most frequently in mitral position [57.9% and prosthetic valve endocarditis and paravalvular leak developed significantly in the aortic valve [40%, 75% [P<0.02 . Mean intervals between the primary valve operation and reoperation were 105.3$\pm$28.4 months in the case of prosthetic valve failure, 61.5$\pm$38.5 months in prosthetic valve endocarditis, 26.8$\pm$31.2 months in paravalvualr leak, and 25.0$\pm$7.0 months in valve thrombosis. In bioprostheses, the intervals were in 102.0$\pm$23.9 months in the aortic valve, and 103.6$\pm$30.8 months in the mitral valve. The overall hospital mortality rate was 7.9% [17/26 : 15% in aortic valve reoperation [6/40 , 6.5% in reoperation on the mitral prostheses [9/135 and 5.7% in multiple valve replacement [2.35 . Low cardiac output syndrome was the most common cause of death [70.6% . Advanced New York Heart Association class [P=0.00298 , explant period [P=0.0031 , aortic cross-clamp time [P=0.0070 , prosthetic valve endocarditis [P=0.0101 , paravalvularr leak [P=0.0096 , and second reoperation [P=0.00036 were the independent risk factors, but age, sex, valve position and multiple valve replacement did not have any influence on operative mortality. Mean follow up period was 38.6$\pm$24.5 months and total patient follow up period was 633.3 patient year. Actuarial survival at 8 year was 97.3$\pm$3.0% and 5 year event-free survival was 80.0$\pm$13.7%. The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, so reoperation before severe hemodynamic impairment occurs is recommended.

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부유물 충돌을 고려한 교각의 홍수 취약도 해석 기법 (Flood fragility analysis of bridge piers in consideration of debris impacts)

  • 김현준;심성한
    • 한국산학기술학회논문지
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    • 제17권5호
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    • pp.325-331
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    • 2016
  • 본 연구에서는 홍수 시 부유물의 충돌하중을 고려하여 교량의 홍수 취약도 곡선을 도출하였다. 자연재해에 의해 불가피하게 발생하는 사회기반시설물의 손상 또는 기능 손실은 심각한 인명피해 뿐만 아니라 국가적으로 사회적, 경제적 손실을 불러올 수 있다. 따라서 국가주요시설물을 재난으로부터 효과적으로 유지관리하기 위해 취약도 곡선은 중요한 도구로 사용되고 있다. 특히 한국은 산지 지형이 많이 형성되어 있고 하절기에 강수량의 2/3이상이 집중되어, 홍수 피해 가능성이 매우 높다. 홍수 시 교량 파괴의 주원인으로는 부유물의 충돌과 하상세굴이 있는데, 부유물의 충돌은 여러 가지 불확실성으로 인하여 상대적으로 연구가 부족한 실정이다. 본 연구에서는 FERUM-ABAQUS 기반의 취약도 해석 시스템을 도입하여, 홍수시 부유물의 충돌에 대한 교량의 취약성을 평가하였다. 교량의 취약도 해석을 효과적으로 수행하기 위하여 한계상태함수, 손상도 지수, 확률변수, 유한요소모델, 취약도 해석 소프트웨어 시스템을 주로 고려하였으며, 가속도 및 변위 응답해석을 통하여 모델 상태를 확인하였다. 다음으로는 홍수 시 부유물 충돌에 발생 가능한 다양한 파라미터를 기반으로 교량의 취약도 곡선을 성공적으로 도출하였다.

기도 및 식도 이물에 대한 임상적 고찰 (Clinical Analysis of Upper Aerodigestive Tract Foreign Body)

  • 이민영;정성도;김영훈;정필상;이상준
    • 대한기관식도과학회지
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    • 제15권1호
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    • pp.28-34
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    • 2009
  • Background and Objectives: Foreign bodies of upper aerodigestive tract are common problem for primary care physicians. Delayed diagnosis or failure of removal might cause fatal problemsand complications. Therefore proper diagnosis and management is imperative. In this study, we described clinical features of upper aerodigestive tract foreign body, and analyzed efficacy of different management modality. Materials and Methods: 250 cases of foreign bodies in the esophagus and trachea, between Jan. 1998 through Jan. 2009 has been retrospectively analyzed. A total of 24 cases and 226 cases had been found each as airway foreign bodies and esophageal foreign bodies. The clinical features are described and treatment outcomes, prognosis, and rate of complications of each management modality have been compared. Results: In airway foreign bodies, ventilating bronchoscopy yielded better results, 19 success out of 19 trials than fiberoptic bronchoscopy, 3 success out of 5 trials. Hospitalization days after removal of foreign body didn't show difference between two treatment modalities, although patients who had ventilating bronchoscopy had gone through general anesthesia. And there was no complication after removal of foreign body. In esophageal foreign bodies, rigid esophagoscope yielded better results, 99% of successful removal rate, compared to the EGD, only 78% of successful removal rate. There was no difference of hospitalization days between two modalities. And complication rate was even low in patients who had done rigid esophagoscopic foreign body removal. Conclusion: In upper aerodigestivetract foreign body. Rapid diagnosis and successful foreign body removal is important. Removal by rigid scope(ventilating bronchoscope, rigid esophagoscope) revealed less failure in both airway and esophageal foreign bodies.

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재활용재료를 이용한 지하매설물용 뒤채움재 - 설계입력변수 정량화 (Backfill Materials for Underground Facility with Recycling Materials - Quantification of Design Parameters)

  • 이관호;김성겸
    • 한국방재학회 논문집
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    • 제11권3호
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    • pp.91-96
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    • 2011
  • 지하매설물은 국가기간시설물로서 설계, 시공 및 유지관리가 적정하게 이루어져야 한다. 이러한 지하매설물 파손의 주요 원인 중의 하나는 부적절한 뒤채움재의 시공이다. 부적절한 뒤채움재 시공은 특히, 원형관로의 시공시 발생하며, 부적절한 다짐으로 인한 침하 및 내구성저하로 인한 파손이 발생한다. 이러한 문제를 해결할 수 있는 하나의 대안으로 유동성뒤채움재를 이용할 수 있다. 유동성뒤채움재는 초기유동성, 시간에 따른 자기강도발현, 무다짐공법 적용 등 많은 장점을 가지고 있다. 본 연구에서는 현장발생토사, 정수장슬러지 및 폐타이어분말 등 재활용 재료를 이용한 유동성 뒤채움재의 기본물성을 평가하였다. 각각의 재활용재료에 대한 입도 및 비중을 평가하였고, 최적배합설계를 결정하였다. 지반 및 도로공학적 설계입력변수 결정을 위해 일축압축시험, 삼축압축시험, 공진주시험 등을 수행하였다.

Treatment of Mycobacterium avium Complex Pulmonary Disease

  • Kwon, Yong-Soo;Koh, Won-Jung;Daley, Charles L.
    • Tuberculosis and Respiratory Diseases
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    • 제82권1호
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    • pp.15-26
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    • 2019
  • The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.