• Korean Journal of Radiology
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• v.20 no.4
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• pp.662-670
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• 2019

Objective: A developmental venous anomaly (DVA) is a vascular malformation of ambiguous clinical significance. We aimed to quantify the susceptibility of draining veins (χ_vein) in DVA and determine its significance with respect to oxygen metabolism using quantitative susceptibility mapping (QSM). Materials and Methods: Brain magnetic resonance imaging of 27 consecutive patients with incidentally detected DVAs were retrospectively reviewed. Based on the presence of abnormal hyperintensity on T2-weighted images (T2WI) in the brain parenchyma adjacent to DVA, the patients were grouped into edema (E+, n = 9) and non-edema (E-, n = 18) groups. A 3T MR scanner was used to obtain fully flow-compensated gradient echo images for susceptibility-weighted imaging with source images used for QSM processing. The χ_vein was measured semi-automatically using QSM. The normalized χ_vein was also estimated. Clinical and MR measurements were compared between the E+ and E- groups using Student's t-test or Mann-Whitney U test. Correlations between the χ_vein and area of hyperintensity on T2WI and between χ_vein and diameter of the collecting veins were assessed. The correlation coefficient was also calculated using normalized veins. Results: The DVAs of the E+ group had significantly higher χ_vein (196.5 ± 27.9 vs. 167.7 ± 33.6, p = 0.036) and larger diameter of the draining veins (p = 0.006), and patients were older (p = 0.006) than those in the E- group. The χ_vein was also linearly correlated with the hyperintense area on T2WI (r = 0.633, 95% confidence interval 0.333-0.817, p < 0.001). Conclusion: DVAs with abnormal hyperintensity on T2WI have higher susceptibility values for draining veins, indicating an increased oxygen extraction fraction that might be associated with venous congestion.

• Economic and Environmental Geology
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• v.22 no.3
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• pp.207-219
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• 1989

Eight under 2 micron size fractions of the montmorillonite from Jugjeonri area, Gyeongsanbug-do, were studied and then this result has been compared with data from Yongdongri area. Montmorillonites occurring at the same stratigraphic horizon in each area show limited variation in chemical composition, but shows some degree of differences in exchangeable cation compositions and total layer charges of montmorillonites from Jugjeonri to Yongdongri area. In general, samples from Jugjeonri show higher amount of exchangeable Na and layer charge due to relatively higher substitution of Mg for Al in octahedral sites than those from Yongdongri area. But Their dehydroxylation endothermic peaks of the samples from both areas are abnormal type with a small range of variation of peak temperature. This variation seems to reflect tetrahedral substitution of AI for Si for samples from Yongdongri whereas samples from Jugjeonri do not show shuch a tendency. However, samples from Jugjeonri proved to be relatively higher dehydroxylation peak temperatures than those of the other. DSC data for sample from Jugjeonri also show that divalent-cation saturated montmorillonite have relatively a higher endothermic heat capacities than monovalent-cation saturated one as shown in previous work. Two different morphologies of montmorillonites, honeycomb structure and closely packed intergrowth, by SEM were observed in samples from both areas but the later one is common. The scalloped type is relatively abundant in the sample from Yongdongri than the other. The dominant habit by TEM are irregularly shaped foliated aggregates and platy shaped particles. In general, foliated aggregates which are easy to disperse are relatively abundant in the samples from Jugjeon compared with those from Yongdongri area.

• Journal of radiological science and technology
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• v.24 no.2
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• pp.19-22
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• 2001

The purpose of this study is to evaluate time course of signal enhancement on Gadomer-17 enhance MRI, and to correlate the size of enhanced area with that of the infarct area on 2'3'5'-triphenyl tetrazolium chloride(TTC) histochemical examination for the assessment of myocardial viability in reperfused Myocardial Infarction in a cat model. Tan cats(average weight: 3.8 kg) which had undergone 90 minutes of occlusion of the LAD followed by 90 minutes of reperfusion underwent MR T2-weighted imaging, and T1-weighted imaging, enhanced T1-weighted imaging. We used 1.5T Magneton Vision MRI system(Siemens, Erlangen, Germany). Signal intensities were measured in the enhanced and non-enhanced areas of enhanced T1-weighted imaging. and TTC histochemical staining the size of the abnormal signal area on each image was compared with that of the infarct area. Maximum enhancement was detected during a $40{\sim}60$ minute period with an average enhancement of $168{\pm}9.9%$ of normal myocardium. TTC staining revealed that the size of the high signal area on T2-weighted images and of the enhanced area on enhanced T1-weighted images was greater than that of the infarct area($T2=48.1%{\pm}3.7$, enhanced $T1=47.2%{\pm}2.6$, TTC $staining=38.7%{\pm}3.1$ ; p<0.05). In reperfused Myocardial Infarction in a cat model, enhanced MR imaging delineates reversibly and irreversibly damaged myocardium, with a strong enhancement and a broad temporal window. We may therefore expect that enhanced MR image is useful for demonstrating myocardial injury.

• Korean Journal of Bronchoesophagology
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• v.5 no.2
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• pp.113-118
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• 1999

Background & Objectives : Nasal resistance which is halfly responsible for airway resistance is known to be influenced by hypoxia, hypercapnia, exercise, pregnancy, alcohol, ammonia and smoking. Smoking is a common part of our sociocultural environment and we have many a times been introduced to its various adverse effects, which have usually been more focused on lung problems. The purpose of this study is to determine any relationship between smoking and nasal resistance and to evaluate it's effective sites. Materials and Methods : Acoustic rhinometry was performed in 25 smokers and 25 nonsmokers who had no nasal symptoms nor abnormal rhinoscopic findings, and used an acoustic rhinometry to measure the distance from nose-piece to the C-notch, cross sectional area at the C-notch, and volume of the nasal cavity from nose-piece to 7cm. The authors compared the data between the two groups. Results : The cross sectional area at the C-notch was significantly decreased(p<0.05) in smoking group. The distance to the C-notch and the volume of nasal cavity were decreased likely in smoking group but there were no significant difference(p>0.05). Conclusion : Smoking reduced the cross sectional area at the C-notch, so increased the nasal resistance. The underlying mechanisms seems to be decreased nasal mucosal reactivity and congestion of the nasal mucosa. The authors believe there should follow more studies on pathophysiologic mechanisms and the histopathologic changes which involve the effect of smoking on nasal structures.

• Tuberculosis and Respiratory Diseases
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• v.42 no.1
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• pp.115-118
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• 1995

A 32-year-old female was admitted for evaluation of known mass on right suprahilar area. Chest PA showed $4{\times}3cm$ round and homogenous mass on suprahilar area. No abnormal findings were found in PFT, cytology, bacterial study, and fine needle aspiration biopsy(FNAB). On chest computed tomography, solitary mass was on right suprahilar area and no evidence of intrapulmonary metastasis or lymphnode metastasis was seen. Right upper lobectomy of lung was performed and Castleman's disease of hyaline vascular type was diagnosed based on the histologic findings of multiple and large lymphoid follicles with prominent vascular proliferation and hyalization in the central portion.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.584-588
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• 2019

Wireless body area network (WBAN) is a networking technology that enables early detection of abnormal health conditions, real-time medical monitoring, and telemedicine support systems. The internet of things (IoT) for healthcare, which has become an issue recently, is one of the most promising areas for improving the quality of human life. It must meet the high QoS requirements of the medical communication system like any other communication system. Therefore, the bit error rate (BER) threshold was chosen to accommodate the QoS requirements of the WBAN communication system. In this paper, we calculated BER performance of WBAN channel using IR-UWB PPM modulation and analyzed link budget and system margin of WBAN according to various system parameters.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.315-320
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• 1975

A total of 364 quarter milk samples of 91 dairy cattle from 4 area around Jeonju in Jeonbug area were examined for infection rate and causative abets of mastitis by the Laboratory Procedures used in the Connecticut Mastitis-Control Program. The results obtained were as follows: 1. One hundred and thirty quarters (35.7%) from 67 cows (73.6%) were found to be infected with mastitis. It was found that 5 (1.37%) of the infected quarters were clinical mastitis and all of the rest were subclinical mastitis (125 quarters). 2. The main causative agents were found to be Staphylococcus aureus (46 quarters), Streptococcus agalactiae (49 quarters), streptococcus disgalactiae (18 quarters), Steptococcus uberis (13 quarters). Corynebacteria, Coliform organisms, Pseudomonas were also occasionally found to be causative organisms. 3. Having examined the number of infection Quarter per head of mastitis dairy cattle samplings, major findings were that the average number of infection quarter to total dairy cattle examined was 1.4 quarters, and that average number of infection quarter to the infected cattle was 1.9 quarters.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.389-397
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• 1993

This is a report of multiple myeloma occurred in the left mandibular body and skull. 66-year-old patient was referred to our hospital with a complaint of painful swelling on the left mandibular body area. The author diagnosed it as a multiple myeloma by the clinical examination, radiographic findings, laboratory findings and the histopathological findings. The purpose of this report is to aid in the diagnosis of multiple myeloma and to aid to differentiate it from malignant tumours. The characteristic features are as follows: 1. In clinical examination, painful swelling was observed in left mandibular body area. 2. In radiographic findings, radiograms showed relatively ill-defined radiolucency without sclerotic border in left mandibular body area. And also represented multiple punched-out radiolucency in the skull and pathologic fracture of vertebral body on lumbar 3 level. 3. In histopathologic findings, infiltration of abnormal plasma cells was observed. 4. In laboratory findings, decreasing of albumin/globulin ratio, hypercalcemia, renal impairment was observed, but we could not find the Bence-Jones protein in urin.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.197-204
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• 2021

If a failure or an abnormal maneuver occurs during the flight test of a missile, the missile is deliberately self-destructed so as not to continue the flight. At this time, debris are produced and it is important to estimate the impact area in real-time whether it is out of the safety area. In this paper, we propose a method to estimate the debris dispersion area and falling time in real-time using a Fully-Connected Neural Network (FCNN). We applied the Unscented Transform (UT) to generate a large amount of training data. UT parameters were selected by comparing with Monte-Carlo (MC) simulation to secure reliability. Also, we analyzed the performance of the proposed method by comparing the estimation result of MC.

• Journal of Veterinary Science
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• v.21 no.5
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• pp.69.1-69.11
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• 2020

Background: An inappropriate Q angle may affect the biomechanics of the canine patellofemoral joint. Objectives: The purpose of this study was to evaluate the effects of changes in quadriceps angle (Q angle) on patellofemoral joint pressure distribution in dogs. Methods: Eight stifles were positioned at 45, 60, 75, 90, 105, and 120° of flexion in vitro, and 30% body weight was applied through the quadriceps. Patellofemoral contact pressure distribution was mapped and quantified using pressure-sensitive film. For the pressure area, mean pressure, peak pressure, medial peak pressure, and lateral peak pressure, differences between groups according to conditions for changing the Q angle were statistically compared. Results: Increases of 10° of the Q angle result in increases in the pressure area (P = 0.04), mean pressure (P = 0.003), peak pressure, and medial peak pressure (P ≤ 0.01). Increasing the Q angle by 20° increases the pressure area (P = 0.021), mean pressure (P ≤ 0.001), peak pressure (P ≤ 0.01), and medial peak pressure (P ≤ 0.01) significantly, and shows higher mean (P ≤ 0.001) and peak pressures than increasing by 10°. Decreasing the Q angle increases the mean pressure (P = 0.013), peak pressure, and lateral peak pressure (P ≤ 0.001). Conclusions: Both increases and decreases in the Q angle were associated with increased peak patellofemoral pressure, which could contribute to the overloading of the cartilage. Therefore, the abnormal Q angle should be corrected to the physiologically normal value during patellar luxation repair and overcorrection should be avoided.