• 제목/요약/키워드: Bleeding

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일차계 모델을 이용한 고분자전해질 연료전지 스택의 CO Poisoning 및 Air Bleeding 효과 분석 (Analysis of the Effects of CO Poisoning and Air Bleeding on the Performance of a PEM Fuel Cell Stack using First-Order System Model)

  • 한인수;신현길
    • Korean Chemical Engineering Research
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    • 제51권3호
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    • pp.370-375
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    • 2013
  • 상업용 막전극접합체를 사용하여 제작한 고분자전해질 연료전지의 CO poisoning 및 air bleeding 효과가 스택의 셀전압 성능에 미치는 영향을 분석하였다. 실험을 통해 확보한 동적 응답 데이터에 일차 미분방정식으로 표현되는 일차계 모델을 적용하여 정상상태 이득과 시간상수를 계산하는 방법으로 스택 셀전압의 응답 특성을 정량화하였다. 연료전지 개질기로부터 공급되는 개질 가스에 포함된 CO 농도가 1 ppm 증가할 때마다 셀전압은 1.3~1.6 mV 저하되고, CO 농도의 변화폭이 클수록 정상상태에 도달하기까지 걸리는 시간이 점점 짧아지는 것으로 분석되었다. CO poisoning에 의해 저하된 스택 성능을 회복시키기 위해 air bleeding을 수행할 경우, 주입하는 공기의 농도를 증가시킬수록 셀전압 상승폭(정상상태 이득)이 커지고 회복시간(시간상수)은 짧아지나, 1% 수준의 air bleeding만으로도 CO poisoning이 일어나기 전 셀전압의 87%~96%를 1~30 min 이내에 회복시킬 수 있는 것으로 분석되었다.

만성신장병환자에서 apixaban과 warfarin의 안전성 비교: 체계적 문헌고찰 및 메타분석 (Apixaban versus Warfarin in Patients with Chronic Kidney Disease; A Systematic Review and Meta-analysis)

  • 남재현;김채영;이유경;정다움;곽혜영;정지은
    • 한국임상약학회지
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    • 제31권2호
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    • pp.87-95
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    • 2021
  • Background: Patients with chronic kidney disease (CKD) are at a high risk of stroke-related morbidity, mortality, and bleeding. However, the overall risk/benefit of anticoagulant therapy among patients with CKD remains unclear. Methods: The MEDLINE, EMBASE, and CENTRAL databases were comprehensively searched until July 31, 2020, to investigate the safety and efficacy of apixaban in patients with stage 4 or 5 CKD, as compared with warfarin. The primary outcome was an incidence of major bleeding. Secondary outcomes included composite bleeding (major, clinically relevant, and minor bleeding), venous thromboembolism (VTE), stroke, and death. Results: In total, seven studies consisting of 10,816 patients were included. Compared with warfarin, apixaban was associated with a reduced risk of major bleeding (OR 0.49, 95% CI 0.41-0.58). In terms of composite bleeding, apixaban tended to pose a significantly lower risk than warfarin (OR 0.51, 95% CI 0.37-0.71). There was no difference between apixaban and warfarin with respect to the risk of stroke or death (stroke: OR 1.23, 95% CI 0.49-3.12; death: OR 0.73, 95% CI 0.45-1.18). Conclusion: Among patients with stage 4 or 5 CKD, the use of apixaban was associated with a lower risk of bleeding compared to warfarin and was also found to pose no excess risk of thromboembolic events.

Food protein-induced proctocolitis: Is this allergic disorder a reality or a phantom in neonates?

  • Hwang, Jin-Bok;Hong, Jeana
    • Clinical and Experimental Pediatrics
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    • 제56권12호
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    • pp.514-518
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    • 2013
  • The etiology of small and fresh rectal bleeding in neonates who are not sick is usually unknown; the only known cause is food protein-induced proctocolitis (FPIPC). It has been recently reported that FPIPC is a rare cause of rectal bleeding in newborns, and most cases have been proved to be due to idiopathic neonatal transient colitis. A recommended strategy for diagnosing suspected FPIPC in neonates is as follows. During the early stage, the etiology of small and fresh rectal bleeding in an otherwise healthy newborn need not be studied through extensive investigations. In patients showing continued bleeding even after 4 days, sigmoidoscopy and rectal mucosal biopsy may be performed. Even if mucosal histological findings indicate a diagnosis of FPIPC, further oral food elimination and challenge tests must be performed sequentially to confirm FPIPC. Food elimination and challenge tests should be included in the diagnostic criteria of FPIPC.

Cervical Spinal Epidural Hematoma Following Cervical Posterior Laminoforaminotomy

  • Choi, Jeong Hoon;Kim, Jin-Sung;Lee, Sang-Ho
    • Journal of Korean Neurosurgical Society
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    • 제53권2호
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    • pp.125-128
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    • 2013
  • A 65-year-old man who had lateral cervical disc herniation underwent cervical posterior laminoforaminotomy at C5-6 and C6-7 level right side. During the operation, there was no serious surgical bleeding event. After operation, he complained persistent right shoulder pain and neck pain. Repeated magnetic resonance image (MRI) showed diffuse cervical epidural hematoma (EDH) extending from C5 to T1 level right side and spinal cord compression at C5-6-7 level. He underwent exploration. There was active bleeding at muscular layer. Muscular active bleeding was controlled and intramuscular hematoma was removed. The patient's symptom was reduced after second operation. Symptomatic postoperative spinal EDH requiring reoperation is rare. Meticulous bleeding control is important before wound closure. In addition, if patient presents persistent or aggravated pain after operation, rapid evaluation using MRI and second look operation is needed as soon as possible.

기훈(氣暈)을 동반한 붕루(崩漏) 환자 치험 1례 (A Case report of Function Uterine Bleeding with Heavy Bleeding)

  • 조국령;김경수;양승정
    • 대한한의학방제학회지
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    • 제14권2호
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    • pp.109-115
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    • 2006
  • A 50-year-old female patient who had anovulational uterine with acute heavy uterine bleeding from the 18th., October, 2006 was hosptalized from the 7th November, 2006 to the 18th, November, 2006 in Dongshindae suncheon Oriental Medical hospital. The patient had been treated with herb-meidcation, acupuncture therapy and moxa therapy. In acupuncture therapy Sp10(Hyulhae, 血海,) Liv3(Taechung, 太衝) Sp6(Samumgyo, 三陰交) Cv6(Gihae. 氣海) Cv12(chunwan, 中脘) L14(Hapgok. 合谷) L7(列缺), were used on the 7th, November, 2006. In the Herbal Therapy, Seungynaggihyultang, Gamiguibitang, was used, In the Moxa therapy, Cv6(Gigae, 氣海) Cv12(chunwnas, 中脘) were used.

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Recent Trends in the Endoscopic Management of Variceal Bleeding in Children

  • Kim, Seung Jin;Kim, Kyung Mo
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제16권1호
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    • pp.1-9
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    • 2013
  • Variceal bleeding results in significant morbidity and mortality in both children and adults. The guidelines for the management of variceal bleeding are well established in adults but not in children as there have been insufficient pediatric studies of this disorder. In addition, the adult guidelines for treatment of variceal bleeding cannot be applied directly to children as the etiology and natural course of this disease differs between children and adults. Examples of recommended treatments in children include endoscopic variceal ligation as secondary prophylaxis for biliary atresia whereas a meso-Rex shunt operation for extrahepatic portal vein obstruction. In this review, we discuss prophylaxis options and some technical aspects of endoscopic management for variceal bleeding in children.

터빈 추기를 이용한 재생 유기랭킨사이클의 열역학적 성능 해석 (Thermodynamic Performance Analysis of Regenerative Organic Rankine Cycle using Turbine Bleeding)

  • 김경훈;황선;김만회
    • 한국수소및신에너지학회논문집
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    • 제26권4호
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    • pp.377-385
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    • 2015
  • This paper presents a thermodynamic performance analysis of regenerative organic Rankine cycle (ORC) using turbine bleeding to utilize low-grade finite thermal energy. Refrigerant R245fa was selected as the working fluid. Special attention is paid to the effects of the turbine bleeding pressure and the turbine bleed fraction on the thermodynamic performance of the system such as net power production and thermal efficiency. Results show that the thermal efficiency has an optimum value with respect to the turbine bleeding pressure and the net power production is lower than the basic ORC while the thermal efficiency is higher.

응고인자 VII 부족 환자에서의 악교정 수술: 증례보고 (Orthognathic surgery in a patient with Factor VII deficiency: A Case Report)

  • 백롱민;오명준;이상우
    • Archives of Plastic Surgery
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    • 제36권1호
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    • pp.93-95
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    • 2009
  • Purpose: Congenital factor VII (FVII) deficiency is a rare bleeding disorder and surgery can cause excessive bleeding due to an extrinsic pathway problem. It can be diagnosed by increased PT and decreased FVII level in coagulation test. Symptom varies according to the level of FVII, but it is essential to prevent intraoperative excessive bleeding. Methods: In this report, we described the orthognatic surgery experience in a mandibular prognathism patient with congenital FVII deficiency, in which recombinant activated factor VII (rFVIIa) was used to manage the bleeding. Rsults: We could get a successful result without any complication and there was minimal intraoperative bleeding. Conclusion: The orthognathic surgery could therefore be safely performed in patients with congenital factor VII deficiency using rFVIIa.

Evaluation of Bleeding After Denal Extraction in Patients Taking Single Antiplatelet Treatment

  • Kim, Jae Jin;Kim, Hak Kyun
    • International Journal of Oral Biology
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    • 제40권3호
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    • pp.147-150
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    • 2015
  • The purpose of this study was to evaluate the effect of single antiplatelet treatment on delayed bleeding, in patients undergoing dental extraction. A total of 154 teeth were extracted in 94 patients with ongoing antiplatelet treatment, who were taking single antiplatelet of either aspirin or clopidogrel. All patients underwent simple dental extraction; local hemostasis was performed with gauze-biting, suturing, and/or application of a local hemostatic agent. Delayed bleeding was recorded in 5 teeth out of a total of 154 teeth after extraction, the incidence of postoperative delayed bleeding being 3.2%. The bleeding was controlled by the patients themselves, through application of pressure with additional gauze-biting. No one visited the doctor or emergency room for hemostasis. These results confirmed that patients taking single antiplatelet drugs may have teeth extracted safely without interruption of the antiplatelet treatment.

항혈소판제를 투여받는 환자의 치과치료 (Dental treatment of the patient with antiplatelet agent)

  • 박홍주
    • 대한치과의사협회지
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    • 제57권10호
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    • pp.606-612
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    • 2019
  • Antiplatelet agent is administered to the patients who have ischemic heart disease, transient cerebral infarction, as well as hypertension, etc. Antiplatelet agent prevents thromboembolism by inhibition of platelet aggregation by various mechanism. Due to that reason, patient who administered antiplatelet agent has bleeding tendency. Surgeon does not want to make a complication by bleeding during and after operation, and want to stop taking antiplatelet agent. However, It is very dangerous for the patient to stop antiplatelet agent. Local bleeding as a complication after operation is considered minor one, whereas thromboembolism is life threatening serious complication. Most dental intervention can be performed without withdrawal of antiplatelet agent. Dental intervention should be limited area, and surgeon should do active bleeding control.

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