• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.78-85
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• 2023

This study evaluates the performance of reinforced concrete columns using hybrid fiber sheets for structural behavior. The purpose of this method is to improve the load-bearing capacity of the reinforced structure by impregnating a hybrid fiber sheet, which is woven by arranging aramid and glass fibers uniaxially and attached to an aged concrete structure requiring reinforcement with epoxy. In particular, not only the weight reduction of the material obtained by using a fiber lighter than the steel material, but also the low-strength, high-toughness fiber element among the fibers used delays the brittle fracture of the high-strength, low-toughness fiber element. The low-strength, high-toughness fiber element among the fibers used delays the brittle fracture of the high-strength, low-toughness fiber element, resulting in weight reduction compared to steel. The study conducted structural tests on four specimens, with the hybrid reinforcement method and failure mode as main variables. Specimen size and loading conditions were chosen to be comparable with previous studies. The structural performance of the specimen was evaluated using energy dissipation capacity and ductility. Analysis shows that excellent results can be obtained with the hybrid fiber sheet reinforcement.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.465-472
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• 2023

In predicting vascular disease, this study attempted to identify changes in the carotid intima-media thickness in patients who underwent carotid artery ultrasonography and hematological tests and to find out the effect of risk factors on the expression of atherosclerotic plaque. A retrospective analysis was conducted on 469 healthy adults who visited the hospital for the purpose of medical examination and performed carotid artery ultrasonography. As a result, carotid intima-media thickness, age, body mass index, waist circumference, systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and glucose were analyzed as significant predictors of atherosclerotic plaque (p<0.001). The risk ratio was calculated based on the cut off value of the risk factors of the atherosclerotic plaque determined through ROC curve analysis, followed by 8.06 times the carotid intima-media thickness, 7.53 times the age, 3.97 times the waist circumference and 2.02 times the glucose. Therefore, in this study it was possible to prepare a Korean standard for clinical risk factors that affect the presence of absence of atherosclerotic plaque and observation of carotid artery ultrasonography is thought to help diagnose or predict cardiovascular disease early.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.22-29
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• 2023

In the evaluation of seismic performance for structural materials and components, the loading rate and axial force can have a significant impact. Due to time-delay effects between input and output displacements, It is difficult to apply high-rate displacement in cyclic tests and hybrid simulations. Additionally, the difficulty of maintaining a consistent vertical load in the presence of lateral displacement has limited fast and real-time tests performed while maintaining a constant vertical load. In this study, slow, fast cyclic tests and real-time hybrid simulations were conducted to investigate the rate dependency and the influence of vertical loads of Isolation Bearing. In the experiment, the FLB System including an Adaptive Time Series (ATS) compensation and a state estimator was constructed for real-time control of displacement and vertical load. It was found that the vertical load from the superstructure and loading rate can have a significant impact on the strength of the seismic isolation bearing and its behavior during an earthquake. When conducting experiments for seismic performance evaluation, they must be implemented to be similar to reality. This study demonstrates the excellent performance of the system built and used for seismic performance evaluation and enables accurate and efficient seismic performance evaluation.

• The Korean Journal of Nuclear Medicine
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• v.33 no.5
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• pp.452-460
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• 1999

Purpose: The purpose of this study was to evaluate the diagnostic usefulness of scintimammography per-formed with Tc-99m tetrofosmin in the detection of primary breast cancer Materials and Methods: Sixty-one patients underwent Tc-99m tetrofosmin scintimammography, plain-film mammography and ultrasonography. After intravenous injection of Tc-99m tetrofosmin (740 MBq), prone lateral and anterior scintimammograms were obtained. Scintimammogram was visually interpreted as positive, probably positive, probably negative and negative for malignancy. The tumor to background count ratio (T/B) was measured at 5 minutes and 1 hour. Plain-film mammogram was interpreted as one of 5 categories. Final diagnosis was achieved by surgical histology (58/61) or fine needle aspiration (3/61). Of 61 patients, 44 had cancer and 17 had benign lesion. Tumor size of malignant and benign lesions on ultrasonogram were $2.51{\pm}1.30cm$ (range 1-8 cm), $2.50{\pm}1.35cm$ (range 0.96-6 cm), respectively. Results: The sensitivity of plain-film mammography was 88.6%, specificity 58.8%, positive predictive value 84.7%, and negative predictive value 66.7% The sensitivity of Tc-99m tetrofosmin scintimammography was 90.9%; specificity, 88.2%; positive predictive value, 94.9%, negative predictive value, 18.9%. Of 25 patients with indeterminate degree of suspicion for malignancy on plain-film mammogram, 23 were correctly diagnosed by scintimammography. The T/B at 5 minutes and 1 hour were $3.78{\pm}2.21$, $3.25{\pm}1.80$ respectively. The T/B was decreased significantly at 1 hour (p<0.001). Conclusion: Tc-99m tetrofosmin scintimammography was useful dia-gnostic procedure in the detection of primary breast cancer, especially in patients with indeterminate degree of suspicion for malignancy on plain-film mammogram.

• Tuberculosis and Respiratory Diseases
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• v.52 no.4
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• pp.367-375
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• 2002

Background : Murine typhus is a flea-borne, worldwide Rickettsial disease caused by Rickettsia typhi. Its symptoms are typically mild but sometimes can be fatal. The major clinical features include fever, rash, and headache. Recently, we experienced 6 cases of ARDS associated with a Rickettsia typhi infection. This study was aimed to analyze the attributing factors for fatal murine typhus and to review the characteristics of the patients who showed acute respiratory distress syndrome as the initial presentation. Methods : The medical records of 15 patients diagnosed as murine typhus were reviewed. The diagnosis was made by single titers of 1:512 or higher, or a 4-fold rise with compatible clinical features. Acute Respiratory Distress Syndrome (ARDS) was defined according to the American-European Consensus Conference. The Characteristics between the ARDS group and the non-ARDS group of murine typhus were compared. Results : Six patients developed ARDS as their initial presentation. Two of them were women and three of them had lived urban area. None of Them a showed skin rash. One of them expired during treatment. The time lapse until the commencement of the specific treatment, the lower serum albumin level, the higher serum total bilirubin level, the higher APACHE III score and the higher MOD score were significantly associated with the ARDS group compared to the non-ARDS group. Conclusion : Murine typhus should be considered as one of the etiologies for the ARDS of unknown cause, particularly in an endemic regions. ARDS caused by Murine typhus generally has a good prognosis.

• Tuberculosis and Respiratory Diseases
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• v.54 no.3
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• pp.283-294
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• 2003

Introduction : Rapidly growing nontuberculous mycobacteria (RGM) can produce numerous types of manifestations including a pulmonary infection. Managing a pulmonary infection due to RGM is unusually difficult to treat because the organism is invariably resistant to traditional antituberculous drugs and has a varying susceptibility to other antibiotics. The experiences of treatments for a RGM pulmonary infection with various antibiotics are also limited. This study evaluated the clinical manifestations, treatment, and the therapeutic outcomes of a RGM pulmonary infection. Subjects and method : Fifty-four cases with RGM from respiratory specimens were identified between November of 1996 and September of 2002 in the Asan medical center. The medical records and radiographic findings in 20 patients who fulfilled the diagnostic criteria of nontuberculous mycobacteria (NTM) pulmonary disease by ATS guidelines. The clinical, laboratory, and radiological parameters between subgroups. Results : Of the 20 patients, 15 were female. The mean age was 57.7 yrs (${\pm}7.5$), and all of the patients had a history of pulmonary tuberculosis. Most (90%) had an underlying lung disease. The majority of the isolates (80%) were M. abscessus. Chest radiography showed bilateral involvement in 80% of the patients. Bronchiectasis and multiple nodules were the main findings. Cavitation was present in 35% of the patients. Even though 70 % of the patients received antituberculous drugs prior to the correct diagnosis, all of the patients eventually received antibiotics. A mean of 3.5 antibiotics were given for an average of 439 days(${\pm}168$). After completing treatment, nine patients showed improvement after a mean 591(${\pm}311$) days of treatment, whereas the antibiotic treatment was unsuccessful in 2 patients. Conclusion : Many patients with a RGM pulmonary infection show an atypical pattern of radiological findings (bronchiectasis and multiple centrilobular nodules). It is very important to differentiate between M. tuberculosis and NTM and to identify the causative organisms among the NTM because a misdiagnosis can lead to an inappropriate and prolonged treatment. Combined antibiotic treatment yielded promising results, and is recommended for treating patients with a RGM pulmonary infection.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.12 no.1
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• pp.23-34
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• 2012

Purpose: Acute symptomatic seizures are caused by structural changes, inflammation or metabolic changes of brain, such as tumor, stroke, meningitis, encephalitis and metabolic disorders. Inherited metabolic disorders that can cause seizures are organic acidopathies, lysosomal storage disorders, peroxisomal disorders and mineral disorders. We have done this study to find out the importance of organic acidopathies causing seizure disorders in Korean childhood and adolescent patients. Method: Retrograde analysis for 1,306 patients with seizure disorders whose clinical informations are available and have done urine organic acid analysis for 5 years period, between Jan. 1st 2007 to Dec. 31th 2011. Statistical analysis was done with Student's t test using SPSS. Result: Out of 1,306 patients, 665 patients (51%) showed abnormalities on urine organic acid analysis. The most frequent disease was mitochondrial respiratory chain disorders (394, 30.1%), followed by mandelic aciduria (127, 9.7%), ketolytic defects (81, 6.2%), 3-hydroxyisobutyric aciduria (19, 1.4%), glutaric aciduria type II (10, 0.8%), ethylmalonic aciduria (4), propionic aciduria (4), methylmalonic aciduria (3), glutaric aciduria type I (3), pyruvate dehydrogenase deficiency (3), pyruvate carboxylase deficiency (3), isovaleric aciduria (2), HMG-CoA lyase deficiency (2), 3-methylcrotonylglycinuria (2), fatty acid oxidation disorders (2), fumaric aciduria (1), citrullinemia (1), CPS deficiency (1), MCAD deficiency (1). Conclusion: On neonatal period, mandelic aciduria due to infection was found relatively frequently. Mitochondrial disorders are most frequent etiologic disease on all age group, followed by ketolytic defects and various organic acidopathies. The number and diversities of organic acidopathies emphasize meticulous evaluation of basic routine laboratory examinations and organic acid analysis with initial sample on every seizure patient.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.3
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• pp.148-154
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• 2006

Purpose: Although radionuclide cisternography (RNC) is an useful study to detect cerebrospinal fluid (CSF) leakage in the patient with spontaneous intracranial hypotension (SIH), it sometimes fails to demonstrate the site of CSF leakage. The aim of the study is to improve the detection of leakage site of CSF and to reduce time for the study in RNC using modified protocol (m-RNC). Materials & methods : The study consists of 8 studies of 7 patients ($38{\pm}8$ years, M:F=2:5) with SIH, who underwent m-RNC following administration of 185-222 MBq of $^{99m}Tc$-DTPA into the lumbar subarachnoid space. Sequential images were obtained the whole spine with the head including urinary bladder at 10 minute, 30 minute, 1 hour, 2 hour, 4 hour and 6 hour. Radioactivity of extradural space and urinary bladder was evaluated. Results: Leakage site of CSF was identified in all 8 cases by m-RNC. Leakage site was cervicothoracic junction (CTJ, n=3), CTJ with C1-2 (n=2), CTJ with thoracic spine, thoracolumbar spine and lumbar spine (each n=1). All cases presented leakage sites within 1 hour and multiple sites, where CTJ was included in 6 cases. Only one case presented additional site in 6 hour image. Early radioactivity within the urinary bladder was noted in 6 cases, but that was fellowing after identification of the leakage site. Conclusion: Radionuclide cisternography is sensitive to detect the leakage site of CSF and is expected to improve the detection of CSF leakage site and reduce time for the study using modified protocol.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.484-491
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• 1995

It is well known that hepatobiliary agent are taken up by metastatic hepatocellular carcinoma(HCC) as well as primary HCC. But the reported cases of the extrahepatic metastasis of HCC diagnosed by hepatobiliary scintigraphy are for the most part hematogenous ones. The relation of the uptake pattern of hepatobiliary agent in the primary and metastatic HCC is also still remains unknown. So we undertook this study to evaluate the relation of the hepatobiliary scintigraphic patterns of primary and metastatic HCC with different metastatic routes. Nine patients with primary HCC and twelve cases of metastatic HCC including four lung metastases, one bone metastasis, one right atrial metastasis, one peritoneal wall metastasis, and five lymph node metastases were studied with $^{99m}Tc-DISIDA$ scintigraphy. The images were taken on 10, 30 minutes, 1, 2, 4-6 hours. The overall detection rates of hematogenous metastases(lung and bone) is 60%(3 of 5), direct metastasis(right atrium and peritoneal wall), 100%(2 of 2) and lymphatic metastases, 0%(0 of 5). In four of five metastatic cases demonstrated with hepatobiliary scintigraphy, biliary agent is also taken up by primary HCC lesions. And the appearing time of the radioactivity in the direct metastatic HCC lesioin is same as that of primary HCC and in the cases of hematogenous metastasis, earlier than that of primary HCC. Hepatobiliary scintigraphy is more useful in the diagnosis of the metastatic HCC than primary HCC, in the cases of hematogenous and direct metastasis.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.2
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• pp.35-42
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• 2018

Purpose: To follow up Korean patients with metabolic and endocrine disorders ascertained by Korea Genetics Research Center, and assess the long-term effectiveness of extended newborn screening program in Korea. Methods: From January 2000 to December 2017, tandem mass spectrometry and fluoroimmunoassay were employed in extended newborn screening (NBS). The NBS program obtained dried blood spots from 283,626 babies, 48 hours after birth, and screened for galactosemia, congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), and 50 preventable inborn errors of amino acid, fatty acid, and organic acid metabolism. Results: 28 cases of amino acid disorders, 75 cases of organic acid disorders, 27 cases of fatty acid disorders, 51 cases of urea cycle disorders, 127 cases of CH, 14 cases of CAH, and 15 cases of galactosemia were ascertained through NBS and subsequent confirmatory laboratory tests. Patients with amino acid metabolic disorders, galactosemia, CH, or CAH were more likely to have a better long-term outcome if detected early. Early management of MSUD led to much better outcome in over 90%. Despite early intervention, 32% of other organic acidemia cases still resulted in developmental delay and neurological problems. Fatty acid disorders showed varied results; those with EMA and MCAD had a good outcome, but those with VLCAD had serious neurological problems and considerably higher mortality. 75% with UCD experienced serious neurological complications and higher mortality. Conclusion: The nation-wide NBS program must be accompanied by comprehensive long-term management and physician and family education of inborn errors of metabolism for a better outcome.