• Title/Summary/Keyword: Common-cause failure

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Assessment of CATHARE code against DEC-A upper head SBLOCA experiments

  • Anis Bousbia Salah
    • Nuclear Engineering and Technology
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    • v.56 no.3
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    • pp.866-872
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    • 2024
  • Design Extension Conditions (DEC)-A assessments of the operating nuclear power plants are generally considered for the purpose of getting additional safety demonstrations of their capability to undergo conditions that are generally more severe than DBAs by features implemented in the design and accident management measures. The pursued methodology is generally based upon Best Estimate approaches aiming at verifying that the safety limits in terms of integrity of the barriers against eventual large or early releases of radioactive material are fulfilled. These aspects are nowadays being experimentally and analytically addressed within the OECD/NEA experimental projects like the ATLAS and PKL series where a set of DEC-A experiments are considered. In this paper, experiments related to SBLOCA at the vessel upper head of the pressurized vessel of ATLAS and PKL are analytically assessed using the CATHARE code. These experiments includes issues related to common cause failure of the safety injection system and operator actions for preventing core excessive overheating. It is shown that, on the one hand, the safety features embedded in the design together with the operator actions are capable to prevent the progression towards a severe accident state and on the other hand, the code prediction capabilities for such scenario are generally good but still to be enhanced.

The Analysis of Risk Factors of Pulmonary Tuberculosis Patients Failed in Retreatment (재치료실패 폐결핵 환자의 위험인자 분석)

  • Kim, Hyoung-Soo;Lee, Won-Jin;Kong, Seok-Jun;Shon, Mal-Hyun
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.6
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    • pp.684-690
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    • 2000
  • Background : The most common cause of treatment failure of pulmonary tuberculosis is early stoppage of treatment or irregular medication. The most important aspect of a retreatment is regular medication provided over a long period. Inadequate treatment may cause drug resistance and prolong the duration of chemotherapy. This study analyzed the risk factors of pulmonary tuberculosis patients, who failed in retreatment, and to use the results as basic data in the management of intractable tuberculosis patients with improving the rate of retreatment success. Methods : We performed a retroactive study of 62 pulmonary tuberculosis patients in retreatment at National Mokpo Tuberculosis Hospital from Jan. 1994 to Dec. 1995. The patients were separated into two groups: group I was retreatment failure and group II was retreatrnent success. For the analysis of risk factors in retreatment failure, we compared the difference between the two groups and tested the confidence limit about results of the results by independent t-test, ${\chi}^2$ test and Fisher's exact test. Results : The treatment failure rate of retreatment patients was 13(21%), and treatment success 49(79%). No significant difference (p>0.05)in age, sex, number of treatment, irregular rate of treatment, extent of the disease & cavitary lesion on the chest X-ray, number of resistance drugs, number of used drugs to medication, number of sensitive bactericidal drugs to medication, rate of sensitive drugs to medication and resisiance to INH & RFP had not significant difference. was found. However, the number of treatment was $2.4{\pm}0.8$ in group I and $1.6{\pm}0.9$ in group II, and had showing a significant difference(p<0.05) between the two groups. Conclusion : The risk factor of retreatment failure was more irregular previous treatment the irregularity of the previous treatment. For reducing the retreatment failure of pulmonary tuberculosis, greater efforts are needed more need to be done to prevent failure of first treatment.

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Clinical Study of Children Using Home Mechanical Ventilation (가정용 인공 호흡기를 사용하는 소아의 임상적 고찰)

  • Ahn, Young Joon;Lee, Seung Hyeon;Kim, Hyo-Bin;Park, Seong Jong;Ko, Tae Sung;Hong, Soo Jong
    • Clinical and Experimental Pediatrics
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    • v.48 no.4
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    • pp.401-405
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    • 2005
  • Purpose : The use of mechanically-assisted ventilators at home reduces morbidity and improves the quality of life in children with chronic respiratory failure. But in Korea there is no clinical data of children with home mechanical ventilation. We investigated ventilator types, duration, the causes of failure or death, and the cost needed for care. Methods : We retrospectively analyzed the medical records of 21 children who were admitted and who applied for home mechanical ventilation at the Pediatric Intensive Care Unit in Asan Medical Center. Phone interviews took place after discharge. and interviewed by phone after discharge. Results : The median age was 31 months; the median duration with ventilator was 25 months. Underlying diseases were 16 neuromuscular diseases, one metabolic disease and four chronic respiratory diseases. The types of ventilator were pressure and volume type(16 and five patients, respectively). The frequency of ventilation failure was once per 19 months. Weaning could be performed in three cases. Frequencies of admission after receiving ventilators were 1.7 times per year; the most common cause was pneumonia. Nine patients(43%) died; four of them died because of endotracheal tube obstruction. The costs for medical care were about 1,110,000 won per month. Conclusion : There is an increment in the numbers of individuals who need mechanical ventilation support. The most common cause of death was endotracheal tube obstruction. The most important problem for the patients was medical cost. There needs to be more interest in patients with ventilator and social welfare systems to support their families need to be prepared.

Hemolytic uremic syndrome (용혈성 요독 증후군)

  • Park, Hye Won
    • Clinical and Experimental Pediatrics
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    • v.50 no.10
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    • pp.931-937
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    • 2007
  • The hemolytic uremic syndrome (HUS) is a rare disease of microangiopathic hemolytic anemia, low platelet count and renal impairment. HUS usually occurs in young children after hemorrhagic colitis by shigatoxin-producing enterohemorrhagic E. coli (D+HUS). HUS is the most common cause of acute renal failure in infants and young children, and is a substantial cause of acute mortality and morbidity; however, renal function recovers in most of them. About 10% of children with HUS do not reveal preceding diarrheal illness, and is referred to as D- HUS or atypical HUS. Atypical HUS comprises a heterogeneous group of thrombomicroangiopathy (TMA) triggered by non-enteric infection, virus, drug, malignancies, transplantation, and other underlying medical condition. Emerging data indicate dysregulation of alternative complement pathway in atypical HUS, and genetic analyses have identified mutations of several regulatory genes; i.e. the fluid phase complement regulator Factor H (CFH), the integral membrane regulator membrane cofactor protein (MCP; CD46) and the serine protease Factor I (IF). The uncontrolled activation of the complement alternative pathway results in the excessive consumption of C3. Plasma exchange or plasma infusion is recommended for treatment of, and has dropped the mortality rate. However, overall prognosis is poor, and many patients succumb to end-stage renal disease. Clinical presentations, response to plasma therapy, and outcome after renal transplantation are influenced by the genotype of the complement regulators. Thrombotic thrombocytopenic purpura (TTP), another type of TMA, occurs mainly in adults as an acquired disease accompanied by fever, neurologic deficits and renal abnormalities. However, less frequent cases of congenital or hereditary TTP associated with ADAMTS-13 (a disintegrin and metalloprotease, with thrombospondin 1-like domains 13) gene mutations have been reported, also. Recent advances in molecular genetics better allow various HUS to be distinguished on the basis of their pathogenesis. The genetic analysis of HUS is important in defining the underlying etiology, predicting the genotype-related outcome and optimizing the management of the patients.

BAG3 mutation in a patient with atypical phenotypes of myofibrillar myopathy and Charcot-Marie-Tooth disease

  • Kim, Seung Ju;Nam, Soo Hyun;Kanwal, Sumaira;Nam, Da Eun;Yoo, Da Hye;Chae, Jong?Hee;Suh, Yeon?Lim;Chung, Ki Wha;Choi, Byung?Ok
    • Genes and Genomics
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    • v.40 no.12
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    • pp.1269-1277
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    • 2018
  • Bcl2-associated athanogene 3 (BAG3) mutations have been reported to cause the myofibrillar myopathy (MFM) which shows progressive limb muscle weakness, respiratory failure, and cardiomyopathy. Myopathy patients with BAG3 mutation are very rare. We described a patient showing atypical phenotypes. We aimed to find the genetic cause of Korean patients with sensory motor polyneuropathy, myopathy and rigid spine. We performed whole exome sequencing (WES) with 423 patients with sensory motor polyneuropathy. We found BAG3 mutation in one patient with neuropathy, myopathy and rigid spine syndrome, and performed electrophysiological study, whole body MRI and muscle biopsy on the patient. A de novo heterozygous p.Pro209Leu (c.626C>T) mutation in BAG3 was identified in a female myopathy. She first noticed a gait disturbance and spinal rigidity at the age of 11, and serum creatine kinase levels were elevated ninefolds than normal. She showed an axonal sensory-motor polyneuropathy like Charcot-Marie-Tooth disease (CMT), myopathy, rigid spine and respiratory dysfunction; however, she did not show any cardiomyopathy, which is a common symptom in BAG3 mutation. Lower limb MRI and whole spine MRI showed bilateral symmetric fatty atrophy of muscles at the lower limb and paraspinal muscles. When we track traceable MRI 1 year later, the muscle damage progressed slowly. As far as our knowledge, this is the first Korean patient with BAG3 mutation. We described a BAG3 mutation patient with atypical phenotype of CMT and myopathy, and those are expected to broaden the clinical spectrum of the disease and help to diagnose it.

Observation of Estrus and Control of Abnormal Estrus in Cattle and Pig (소와 돼지에서 발정관찰과 이상발정의 대책)

  • 김창근
    • Korean Journal of Animal Reproduction
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    • v.7 no.2
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    • pp.72-85
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    • 1983
  • This presentation firstly is discussed the characteristics of estrus, the time of first postpartum estrus, and the relative accurate of various estrus detection aids and secondly discussed the abnormalities of estrus and ovarian function and its control by treatment of exogenous hormones in cattle and pig. Longer estrus cycles as well as the shorter than 18 day cycles showed the lowered conception rates as compared to the normal cycles of 18 to 25 days. Other characteristics of est겨s such as duration of estrus, intensity of estrus and time of estrus are reviewed to affect fertility. The first postpartum ovulation and estrus in cows usually occurs about 20 to 30 days and 40 to 50 days after parturition, respectively. Irregularities in estrus cycle length have been conducted during early postpartum period. In sows, weaning is followed by ovulation and estrus although there is some individual variation. The most common method of estrus detection is direct visual observation on standing estrus behavior, but various aids of estrus detection have been empolyed with varying degree of effectiveness. The results from heat detector devices are about as accurate as twice-daily observation(about 90%). The abnormal estrus can be classified into three types; irregular or continuous estrus, silent estrus and anestrus. Cystic ovarian disease, follicular cysts and luteal cysts, is a serious cause of reproductive failure in cattle and pig. The follicular cysts are much more common than luteal cysts and the incidence of ovarian cysts in dairy cattle is higher than beef cattle and pig. The occurrences of ovarian cysts have been closely associated with levels of milk production, stages of postpartum period, nutritional levels and seasons. The luteal cysts and persistent corpora lutea are responsive to the luteolytic effects of the recently synthetic analogues of PGF2$\alpha$ in cows and sows and recently GnRH or LH-RH has been successfully used as a treatment for cows and sows with ovarian follicular cysts.

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Surgical Observations of Diseases of the Aorta (대동맥질환에 대한 외과적 고찰)

  • Rho, Joon Ryang
    • Journal of Chest Surgery
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    • v.9 no.2
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    • pp.251-264
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    • 1976
  • Forty three patients with disease of the aorta were admitted in this department during the period from beginning of 1956 to the end of 1976. They consisted of eighteen cases of aortic aneurysms, eight cases of Takayasu's arteritis, eight Leriche syndromes, six dissecting aneurysms, two aortic coarctations and one case of vascular ring. Of eighteen aortic aneurysms, twelve were operated resulting in eight survivors. Three of four mortalities were in shock preoperatively because of aneurysmal rupture. Among six dissecting aortic aneurysms, four were type III and two were type I according to DeBakey's classification. For the purpose of relief of acute arterial insufficiency in the lower extremities, a re-entry operation grafting a Y-shaped dacron vessel between abdominal aorta and common iliac arteries was performed. The patient regained consciousness soon after the operation and was well until postoperative second day, when severe convulsion developed abruptly and died. And in a chronic case of type III dissecting aneurysm, a dacron graft bypass shunt between ascending aorta and lower descending thoracic aorta with resection of the aneurysm was performed, but acute severe aortic insufficiency developed soon after the operation and fell into intractable heart failure resulting in death. The cause of the aortic insufficiency seems to be retrograde dissection from the proximal anastomosis site in the ascending aorta. Three cases were treated medically with Wheat's regimen. Two of them survived with relief of symptoms. Eight patients of Takayasu's arteritis were all females and aged between twenty and forty-four averaging twenty nine. Bypass graft operation between aortic arch and carotid arteries using Y-shaped nylon prostheses were performed in three patients resulting in death in two cases postoperatively due to severe cerebral arterial insufficiency during the procedure. All the patients with Leriche syndrome were males and over forty. In two cases, bypass graft with Y-shaped dacron vessel between terminal aorta and common iliac or femoral arteries were performed with good result. Thromboembolectomy or thromboendarterectomy was employed in three patients, of whom one was aggravated in sexual problem postoperatively. One out of two aortic coarctations and a vascular ring were treated surgically with excellent results.

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An Analysis of Infertility Patients (불임증(不姙症) 환자(患者)의 통계적(統計的) 고찰(考察);서울대학교병원(大學校病院) 불임상담실(不姙相談室) 1872 예(例)의 분석(分析))

  • Chang, Y.S.;Lee, J.Y.;Moon, S.Y.;Kim, J.K.;Choi, S.H.;Lim, Y.T.
    • Clinical and Experimental Reproductive Medicine
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    • v.12 no.1
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    • pp.47-70
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    • 1985
  • This study was presented of the 1,872 cases of infertile couples who visited and examined at the sterility clinic of Department of Obstetrics & Gynecology, Seoul National University Hospital from Sept., 1980 to Dec., 1983. Age, duration of infertility, past medical history, and other general factors were analyzed, and the factors responsible for infertility were classified and discussed. Mode of treatment, outcome of pregnancy, pregnancy rate responsible for each factor were also presented. The results were as follows: 1) The infertility was primary in 1,128, or 60.3% and secondary in 744, or 39.7%. 2) The age between 26 and 30 years of age comprised about one half of the total patients. 3) The duration of infertility between 1 and 4 years comprised about three quarters of the total patients, and the mean duration was 3.8 years. 4) The most common medical history in primary infertility was tuberculous disease, and that in secondary infertility was history of previous laparotomy. 5) About two thirds of antecedent pregnancies were abortion. 6) The major etiologic factor of infertility were male factor in 12.3%, tubal factor in 38.8%, ovulatory failure in 25.4%, uterine factor in 8.8%, cervical factor in 5.2%, peritoneal factor in 9.5%, and no demonstrable cause in 11.3%. 7) The types of male factor were azoospermia in 61.6%, oligospermia in 25.8%, low motility in 11.6%, and other abnormality in 1.0%. 8) The types of ovulatory failure were ovarian failure in 7.4%, hypothalamo-pituitary failure in 8.1 %, hypothalamo-pituitary dysfunction (including Polycystic ovarian syndrome) in 30.2%, and hyperprolactinemia in 22.4%. 9) The types of uterine factor were endometrial tuberculosis in 27.5%, uterine synechia in 33.8%, uterine anomaly in 19.7%, myoma and polyp in 9.1 %, and luteal phase defect in 9.9%. 10) The types of peritoneal factor were pelvic adhesion in 80.9% and endometriosis in 19.6%. 11) Surgeries were done in 408 patients, and they were salpingolysis, lysis of extraadnexal adhesion, salpingostomy, fimbrioplasty, ovarian wedge resection for polycystic ovarian disease, tubo-tubal anastomosis, and tubo-uterine implantation in orders. 12) 243 pregnancies were achieved during the infertility work-up, of which livebirth was 46.5%, ectopic pregnancy was 7.4%, spontaneous abortion was 7.8%, and on-going pregnancy or lost to follow-up was 36.2%. 13) Pregnancy rates in various factors were male factor in 18.7%, ovulatory factor in 31.7%, tubal factor in 24.2%, uterine factor in 34.6%, cervical factor in 19.0%, peritoneal factor in 29.0%, combined factors in 10.5%, and unexplained infertility in 37.1%. Pregnancy rate in whole patients was 25.2%.

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A Study on Factors that Trigger Human Errors Related to Causes of Ship Collisions (선박충돌사고 원인과 관련된 인적과실 유발요인에 관한 연구)

  • Kim, Dae-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.7
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    • pp.801-809
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    • 2017
  • The purpose of this study is to contribute to the prevention of ship collisions by investigating real ship collision cases and statistically analyzing causes of human error for captains and Officers of the Watch (OOW). This study encompassed a total of 109 cases for 218 vessels, which were suitable for the analysis of ship accidents between merchant ships or merchant ships and fishing boats over the 7 years from 2010 to 2016. Data was collected while classifying vessels according to type, Give-way and Stand-on vessels, along with the cause of human error. Factors causing human error were identified after focusing on the cause of each collision given by the OOW ; frequency and cross tabulation analyses were conducted using SPSS, a statistical analysis tool. As a result, the main causes of human error by an OOW in a ship collision situation were that lookout was neglected in a Give-way vessel including radar surveillance (74.3 %) or continuous observation of an opponent vessel was carried out (17.4 %). A major factor for Stand-on vessels was failure to act to avoid collision with another vessel (63.3 %). In particular, most neglect for lookout type merchant ships occurred after the opponent ship was first observed, and a common cause of lookout neglect and neglect of duty was a focus on other tasks during navigational watch time.

A Review on Cases of Skin Adverse Reactions through the Search for Articles (논문 검색을 통한 피부 부작용 사례 고찰)

  • Cho, Hye-Sin;Song, Ah-Ryun;Seo, Hyung-Sik
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.31 no.3
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    • pp.50-59
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    • 2018
  • Objectives : The aim of this review is to investigate studies on skin adverse reactions and to demonstrate subjects related to the adverse effects in dermatology. Methods : Electric searches were performed with KISS(Korean studies Information Search System) and the key words were combination of 'skin' and 'adverse effect'. 87 literatures investigated in this review were issued from 1900 to 2016. Results : Among the 87 papers, dermatologic adverse reactions were reported in 83 papers in medicine, accounting for 95.4%. Of the adverse effects seen on the skin, 84 discoloration such as erythema, pigmentation and hemotelangiosis were the most common, accounting for 21%. Among the medical adverse reactions not seen on the skin, 21 infection were the most common, accounting for 25%. Among the subjective adverse reactions, of which 32 pruritus were the most common, accounting for 43%. Among the 87 papers, there were 3 cases with underlying diabetes and 3 cases with underlying hypertension, followed by 2 cases with chronic renal failure, HBV, atopic dermatitis and respectively 1 case with alcoholism, depression addiction, multiple myeloma, arthritis and psoriasis. The most frequent period until adverse reactions appeared was within 2 weeks, accounting for 13 papers. And 4 were the most frequent adverse reactions lasting less than 1 month, and 4 were more than 3 months and less than 6 months. There were 48 cases where adverse reactions were caused by nonmedical practioner's treatment. The adverse reactions by the pharmacist were the highest at 11 cases (23%). There were 17 cases of adverse reactions due to medical treatment, among which dermatologists and nondermatologists accounted for the majority of 5 cases, 29%. The most common cause of adverse reactions was the application of external medicine (41 cases), followed by 36 cases of foreign body implantation, eyebrow tattooing, ear piercing, etc. Conclusions : In this report, we demonstrated patterns of adverse reactions in the medical field of dermatology caused by non-medical personnel than medical personnel. We suggest that more effort should be followed by medical personnel to establish clear awareness of skin disease and by patients to be aware of the risks of the illegal medical treatment by non-medical personnel.