• 한국신뢰성학회지:신뢰성응용연구
• /
• 제6권1호
• /
• pp.51-61
• /
• 2006

Failure analyses were conducted on a crank shaft and a chock liner by using X-ray diffraction, optical microscopy and SEM/EDS techniques. In the crank shaft, a crack developed where a maximum tensile stress coincided with band structure formed by hot forging. The maximum tensile stress was observed to originate from volume expansion during high frequency induction heat treatment and the band structure to develop between upper and lower dies during hot forging. In the chock liner, the wear mechanism varied with the chemical affinity and hardness of liner material relative to friction pair of housing liner. Brass of low chemical affinity and hardness compared to housing liner showed uniform adhesive wear. STS 304 and STS 420J2 of high chemical affinity showed galling and scoring respectively.

• 대한임상독성학회지
• /
• 제7권1호
• /
• pp.32-37
• /
• 2009

Formic acid or formate is a common industrial compound used in the production of ensilage, disinfectants, decalcifying agents and mainly as a precursor in industrial chemical synthesis. It is also a well-known toxic metabolite produced in methanol poisoning. Thus, formate is a potential source of both accidental and deliberate poisoning. Very few reports have been published thus far, on the toxicology of direct formic acid poisoning. Here, we report a case of a 74-year-old man without a history of depression, who ingested about 30 gm of formic acid. The patient presented with profound high anion gap metabolic acidosis, acute renal failure and esophageal stricture. The patient was successfully treated with hemodialysis and supportive measures. But permanent esophageal stricture was complicated by formic acid burns in the gastrointestinal tract. We discuss the pathophysiology and treatment of this case.

• 대한치과보철학회지
• /
• 제41권6호
• /
• pp.714-719
• /
• 2003

Conical crown-retained denture (CCRD) has been used as a very effective treatment method in cases with few remaining teeth with heterogeneous prognosis. However, in spite of many advantages of CCRD, high technical failure rate was a problem to be considered. Incorrect path of insertion and excessive retention were thought to be the main cause of technical failure and to result from laboratory procedure with a coping misfit and/or a coping transfer error. In order to prevent this error, secure anchoring of inner coping and re-examination and milling of convergence angle were recommended on the master model from pick-up impression.

• 한국표면공학회지
• /
• 제33권4호
• /
• pp.241-250
• /
• 2000

Popcorn cracking phenomena frequently occur in thin plastic packages during the solder reflow process, which are definitely affected by poor adhesion of Cu-based leadframe to epoxy molding compounds (EMCs). In the present work, in order to enhance the adhesion strength, a brown-oxide treatment on the Cu-based leadframe was carried out and the adhesion strength of leadframe/EMC interface was measured in terms of fracture toughness by using sandwiched double-cantilever beam (SDCB) specimens. After the adhesion tests, fracture surfaces were analyzed by SEM, AES, EDS and AFM to make the failure path clear. Results showed that failure path was closely related to the oxidation time and the interfacial fracture toughness.

• Journal of Yeungnam Medical Science
• /
• 제22권2호
• /
• pp.131-140
• /
• 2005

Heart failure is a clinical syndrome comprised of a number of symptoms and signs associated with congestion and/or hypoperfusion. Specific pharmacologic therapies have been developed to slow disease progression from early to more advanced stages. Once symptoms have developed, aggressive multimodality interventions are instituted to alleviate symptoms and improve clinical status and quality of life; especially in those patients that present symptoms. Recently, an evolving adjunctive therapeutic modality, that involves using implanted electrical devices: cardiac resynchronization with or without implantable cardioverter defibrillators (ICD). has been used for management. Cardiac resynchronization therapy (CRT) is a proven treatment for selected patients with heart failure-induced conduction disturbances and ventricular dyssynchrony. When used in combination with stable, optimal medical therapy, CRT is designed to reduce symptoms and improve cardiac function by restoring the mechanical sequence of ventricular activation and contraction. This review summarizes the rationale, procedure, clinical trials, and clinical indications for CRT.

• Journal of Medicine and Life Science
• /
• 제17권3호
• /
• pp.103-106
• /
• 2020

Bone marrow failure, such as aplastic or myelophthisic anemia, can occur due to an underlying lymphoid malignancy and cause life-threatening events. A 58-year-old man diagnosed with angioimmunoblastic T-cell lymphoma had recently visited the emergency department because of an altered level of consciousness caused by acute severe anemia. The laboratory findings were strongly suggestive of bone marrow failure syndrome. Bone marrow examination was immediately performed and, subsequently, dexamethasone was initiated to control the underlying lymphoma. Intravenous immunoglobulin was also administered in combination due to combined immune hemolytic anemia and thrombocytopenia. Bone marrow examination revealed a packed marrow with marked fibrosis and lymphoma involvement. A diagnosis of secondary myelofibrosis related to the underlying lymphoma was made, and sequential combination chemotherapy was introduced despite the presence of severe anemia and thrombocytopenia. After combination chemotherapy, his hematologic profile and underlying lymphoma improved. Better understanding of various hematologic manifestations and knowledge of the rare condition of lymphoma are essential for appropriate diagnostic approaches and treatment.

• 한국동물위생학회지
• /
• 제46권1호
• /
• pp.75-79
• /
• 2023

An eight-year-old, 28-kg male bull terrier who showed signs of lethargy and cough was referred for further evaluation of congestive heart failure. On presentation, physical examination revealed a systolic murmur at the left apex of the heart. Moreover, chest radiograph evaluation confirmed the mild alveolar and interstitial patterns in the caudal lung lobes and a grossly enlarged left atrium and left ventricle. Electrocardiography showed atrial fibrillation with a wide QRS complex, and transthoracic echocardiography revealed marked enlargement of the left atrium with abnormal morphology of the mitral valve. The thickened, hammer-like appearance and abnormal diastolic motion of the mitral valve leaflets were characterized by decreased leaflet separation and doming of the valve. The diagnosis was mitral stenosis with congestive heart failure and atrial fibrillation. The owner declined interventional valvuloplasty. Medical treatment included furosemide, pimobendan and diltiazem. Regular health check-ups have shown that vitality and clinical signs have improved considerably, and the dog have remained stable for 6 months after the presentation.

• Journal of Digestive Cancer Research
• /
• 제7권2호
• /
• pp.57-60
• /
• 2019

Definitive chemoradiotherapy (CRT) with its significant efficacy and safety in esophageal cancer is reserved for patients with unresectable tumor or those who decline surgery. However, the incidence of locoregional failure or recurrence after definitive CRT remains high. Although esophagectomy is the standard treatment for locoregional failure or recurrence, this approach is associated with high mortality and morbidity. A 56-year-old man diagnosed with esophageal squamous cell carcinoma who refused to undergo surgery received definitive CRT. An endoscopy for response assessment performed after 2 months revealed a residual lesion, which was completely resected by salvage endoscopic submucosal dissection. To the best of our knowledge, endoscopic resection in locoregional failure or recurrence after definitive CRT is very rarely reported, and there are no guidelines or consensus to date. Here, we report a case of successful salvage endoscopic resection of residual lesion after definitive CRT.

• Radiation Oncology Journal
• /
• 제32권2호
• /
• pp.63-69
• /
• 2014

Purpose: To find the applicability of adjuvant radiotherapy for extrahepatic bile duct cancer (EBDC), we analyzed the pattern of failure and evaluate prognostic factors of locoregional failure after curative resection without adjuvant treatment. Materials and Methods: In 97 patients with resected EBDC, the location of tumor was classified as proximal (n = 26) and distal (n = 71), using the junction of the cystic duct and common hepatic duct as the dividing point. Locoregional failure sites were categorized as follows: the hepatoduodenal ligament and tumor bed, the celiac artery and superior mesenteric artery, and other sites. Results: The median follow-up time was 29 months for surviving patients. Three-year locoregional progression-free survival, progression-free survival, and overall survival rates were 50%, 42%, and 52%, respectively. Regarding initial failures, 79% and 81% were locoregional failures in proximal and distal EBDC patients, respectively. The most common site was the hepatoduodenal ligament and tumor bed. In the multivariate analysis, perineural invasion was associated with poor locoregional progression-free survival (p = 0.023) and progression-free survival (p = 0.012); and elevated postoperative CA19-9 (${\geq}37U/mL$) did with poor locoregional progression-free survival (p = 0.002), progression-free survival (p < 0.001) and overall survival (p < 0.001). Conclusion: Both proximal and distal EBDC showed remarkable proportion of locoregional failure. Perineural invasion and elevated postoperative CA19-9 were risk factors of locoregional failure. In these patients with high risk of locoregional failure, adjuvant radiotherapy could be considered to improve locoregional control.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제15권3호
• /
• pp.113-119
• /
• 2015

Background: The inferior alveolar nerve block (IANB) is the most common anesthetic techniques in dentistry; however, its success rate is low. The purpose of this study was to determine the correlation between IANB failure and mandibular skeletal characteristics Methods: In total, 693 cases of lower third molar extraction (n = 575 patients) were examined in this study. The ratio of the condylar and coronoid distances from the mandibular foramen (condyle-coronoid ratio [CC ratio]) was calculated, and the mandibular skeleton was then classified as normal, retrognathic, or prognathic. The correlation between IANB failure and sex, treatment side, and the CC ratio was assessed. Results: The IANB failure rates for normal, retrognathic, and prognathic mandibles were 7.3%, 14.5%, and 9.5%, respectively, and the failure rate was highest among those with a CC ratio < 0.8 (severe retrognathic mandible). The failure rate was significantly higher in the retrognathic group than in normal group (P = 0.019), and there was no statistically significant difference between the other two groups. Conclusions: IANB failure could be attributable, in part, to the skeletal characteristics of the mandible. In addition, the failure rate was found to be significantly higher in the retrognathic group.