• 제목/요약/키워드: Repeated failure

검색결과 322건 처리시간 0.03초

Immunogenicity of botulinum toxin

  • Wee, Syeo Young;Park, Eun Soo
    • Archives of Plastic Surgery
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    • 제49권1호
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    • pp.12-18
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    • 2022
  • Botulinum toxin treatment is the most common non-surgical cosmetic treatment. Although there are many available treatments using botulinum toxin, their effects are temporary and repeated injections are required. These frequent injections can trigger an immunological response. In addition, botulinum toxin acts as an antigen in the body; thus, its effect disappears progressively due to this immunological reaction, which may cause treatment failure. Active botulinum toxin consists of a core neurotoxin and complexing proteins, the exact effects of which remain unclear. However, the complexing proteins are closely related to the immune response and the formation of neutralizing antibodies. Since neutralizing antibodies can lead to treatment failure, their formation should be prevented. Furthermore, various methods of detecting neutralizing antibodies have been used to predict treatment failure.

체외수정에서 반복 착상 실패(RIF) 환자 침치료 최근 연구 동향 (Recent Research Trends of Acupuncture Treatment for Recurrent Implantation Failure (RIF) Patients in In Vitro Fertilization)

  • 조세연;김승규;황덕상;이진무;장준복;이창훈
    • 대한한방부인과학회지
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    • 제37권2호
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    • pp.120-134
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    • 2024
  • Objectives: This research aimed at investigating the trends of acupuncture treatment for Recurrent Implantation Failure (RIF) patients in IVF. Methods: Studies were searched from PubMed, Cochrane Library, EMBASE, CNKI up to April 2024. Terms as 'Implantation failure', 'Recurrent implantation failure', 'Repeated implantation failure', 'RIF' and 'Acupuncture', 'Electroacupuncture', 'Needling' were used. Results: Of 136 screened, 10 studies are selected and analyzed. Studies were conducted using manual acupuncture and electroacupuncture. The results showed that acupuncture (electroacupuncture) treatment for RIF patients is effective in improving clinical pregnancy rate, endometrial blood flow, uterus morphology, endometrium thickness. The most frequently used acupoints were 三陰交 (SP6) and 子宮 (EX-CA1). Conclusions: Included studies showed that acupuncture (electroacupuncture) might have effect on RIF. Further research and meta-analysis should be conducted to verify its therapeutic mechanisms and safety.

Ovarian stimulation and liver dysfunction: Is a clinical relationship possible? A case of hepatic failure after repeated cycles of ovarian stimulation

  • Giugliano, Emilio;Cagnazzo, Elisa;Pansini, Giancarlo;Vesce, Fortunato;Marci, Roberto
    • Clinical and Experimental Reproductive Medicine
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    • 제40권1호
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    • pp.38-41
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    • 2013
  • Liver damage induced by ovarian stimulation has been demonstrated in some cases reported in the literature. However, there has never been a fruitful debate on this topic. The present manuscript tried to fill this gap. We reported a case of a 35-year-old nulliparous woman admitted to our obstetric emergency room for severe pre-eclampsia. She had been subjected to four cycles of controlled ovarian stimulation for intrauterine insemination. At 32 weeks of gestation, she developed severe pre-eclampsia, which led to HELLP syndrome complicated by fatal liver failure. The etiological link between ovarian stimulation and HELLP syndrome is intriguing. Further investigations are needed to understand whether repeated ovarian stimulation may represent a risk factor in pre-eclamptic patients.

Chronic endometritis and infertility

  • Park, Hyun Jong;Kim, You Shin;Yoon, Tae Ki;Lee, Woo Sik
    • Clinical and Experimental Reproductive Medicine
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    • 제43권4호
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    • pp.185-192
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    • 2016
  • Chronic endometritis (CE) is a condition involving the breakdown of the peaceful co-existence between microorganisms and the host immune system in the endometrium. A majority of CE cases produce no noticeable signs or mild symptoms, and the prevalence rate of CE has been found to be approximately 10%. Gynecologists and pathologists often do not focus much clinical attention on CE due to the time-consuming microscopic examinations necessary to diagnose CE, its mild clinical manifestations, and the benign nature of the disease. However, the relationship between CE and infertility-related conditions such as repeated implantation failure and recurrent miscarriage has recently emerged as an area of inquiry. In this study, we reviewed the literature on the pathophysiology of CE and how it may be associated with infertility, as well as the literature regarding the diagnosis and treatment of CE. In addition, we discuss the value of hysteroscopic procedures in the diagnosis and treatment of CE.

Ultimate and fatigue response of shear dominated full-scale pretensioned concrete box girders

  • Saiidi, M. Saiid;Bush, Anita
    • Structural Engineering and Mechanics
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    • 제23권4호
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    • pp.353-367
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    • 2006
  • Two full-scale, precast, pretensioned box girders were subjected to shear-dominated loading, one under monotonic loads to failure and the other subjected to one-half million cycles of fatigue loads followed by monotonic ultimate loads. The number of cycles was selected to allow for comparison with previous research. The fatigue loads were applied in combination with occasional overloads. In the present study, fatigue loading reduced the shear capacity by only six percent compared to the capacity under monotonic loading. However, previous research on flexure-dominated girders subjected to the same number of repeated loads showed that fatigue loading changed the mode of failure from flexure to shear/flexure and the girder capacity dropped by 14 percent. The comparison of the measured data with calculated shear capacity from five different theoretical methods showed that the ACI code method, the compression field theory, and the modified compression field theory led to reasonable estimates of the shear strength. The truss model led to an overly conservative estimate of the capacity.

복사전열 가열로 튜브의 파손방지에 대한 연구 (A Study on Failure Prevention of Radiant Heater Tube)

  • 윤기봉;심상훈;유홍선;오현환
    • 한국안전학회지
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    • 제13권1호
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    • pp.47-53
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    • 1998
  • Radiant heater tubes with an inside burner are designed to transfer the heat generated from the burner to the outside of the tube by radiation. Hence, tube metal must suffer high temperature of approximately 900-$1000^{\circ}C$. The radiant tube is usually manufactured by centrifugal casting with high Ni-Cr alloys. In this study, failure analysis results of the radiant tube are reported. Failure mechanism of the tube was investigated by visual observation of the foiled tube, metallographic study of the cracked region and chemical analysis of tube metal and oxide scales. It was argued that the main cause of the cracking is repeated oxidation of the tube metal located beneath the thick oxide scale. Oxidation was caused by abnormally high operating temperature which can be verified by aged microstructure and internal void formation.

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휠로더 엔진 밸브 커버 볼트의 파손 원인 규명 및 개선 (A study on the fatigue fracture of engine valve cover bolt for a wheel loader)

  • 이군희;주원호;김동해;배종국
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.1218-1222
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    • 2006
  • The bolts fixing the valve cover to the engine were often reported to be failed in a wheel loader model. Recently this failures were continually repeated in the specified equipment. In order to identify the fatigue fractures of the bolts, various vibration tests were carried out. From these tests, it was found out that the failure was due to the resonance between the excitation force of engine and the transverse mode of engine valve cover. So, the several modifications for the bolts were considered to avoid the resonance. Finally, the bolt failure problem was clearly resolved.

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기계 학습을 이용한 치구 공정 계획 모듈의 개발 (A Development of Fixture Planning Module using Machine Learning)

  • 김선우;이수홍
    • 한국CDE학회논문집
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    • 제2권2호
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    • pp.111-121
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    • 1997
  • This study intends to develop a fixture planning module as a part of the planning system for cutting. The fixture module uses machine learning method to reuse previous failure results so that the system can reduce the repeated failures. Machine learning is one of efforts to incorporate human reasoning ability into a computerized system. A human expert designs better than a novice does because he has a wide experience in a specific area. This study implements the machine learning algorithm to have a wide experience in the fixture planning area as a human expert does. When the fixture planner finds a setup failure for the suggested operations by a process planner, it makes the process planner store its attributes and other information for the failed setup. Then the process planner applies the learned knowledge when it meets a similar case so that the planner can reduce possibility of setup failure. Also the system can teach a novice user by showing a failed setup with a modified setup.

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가속내구해석을 이용한 평기어의 신뢰성 평가 (An Evaluation of Reliability of the Spur Gear Using the Accelerated Durability Analysis)

  • 김철수;김정규;권여현
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 추계학술대회 논문집
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    • pp.722-727
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    • 2004
  • The gear that is used in various mechanical components occurs easily damages due to the repeated torque and the high oil temperature. The main failure mode of the gear is the surface deterioration with the tooth surface fatigue. Therefore, the life evaluation and the failure analysis of the gear were very important since it may cause fatal damage of entire gear box system. In this paper, the failure mechanism and the life of the gear were evaluated using the durability analysis simulator such as MSC.FATIGUE. Moreover, the reliability analysis model of the spur gear with the accelerated life testing technique was proposed.

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창의적 문제해결 이론을 이용한 소성역깊이 측정에 관한 연구 (A Study on the Measurement of Plastic Zone Depth using TRIZ)

  • 이동우;주원식
    • 한국기계가공학회지
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    • 제7권1호
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    • pp.62-66
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    • 2008
  • Machine parts subjected to fluctuating or cyclic loads induce repeated stresses that often result in failure by fatigue. In such cases, the fatigue failures unfortunately sometimes occur. These may arise from a lack of knowledge with regard to the design, fabrication and operation of the machines or structures. The failure analysis provides valuable information regarding the prevention of similar failures. Furthermore, this information will be useful to improve or to develop new products. Failure stress analysis is classified into X-ray fractography. X-ray fractography has the limited applications because of material crystal size, difficult measurement method, electrolytic polishing precision, and long test time. Therefore, this study proposed the new method to improve the measurement precision of plastic zone depth and test time using TRIZ.

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