• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.89-94
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• 1992

A 16 years old girl with systemic lupus erythematosus had a high fever for 20 days. Skin and renal biopsy showed diffuse granular deposits (IgG, IgM, $C_3$, $C_{1q}$ at dermo-epideral junction and IgG, IgA, IgM, $C_3$, $C_{1q}$, fibrinogen in the renal mesangium and segmentally along the capillary walls) which were compatable with systemic lupus erythematosus. The chest X-ray revealed patchy mottled densities in whole lung field when she complained more dyspnea at 9th hospital days. Even with the parenteral administration of broad-spectrum antibiotics, the symptoms of high fever, cough, tachydyspnea and hypoxia were continued. At 24th hospital day, the clinical course was rapidly deteriorated after sudden loss of consciousness with focal seizure which suggested CNS involvement during hydrocortisone administration for 10 days. She died of respiratory failure despite the mechanical ventilatory support with PEEP. The limited necropsy showed interstitial pneumonia, alveolar hemorrhage and occlusive necrotizing vasculitis of acute lupus pneumonitis.

• Journal of Korean Society of Steel Construction
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• v.14 no.1
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• pp.121-130
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• 2002

This paper presents the tensile behavior of a Concrete-Filled Square Steel Tubular (CFT) column to H-beam welded connections. These connections were externally reinforced with T-shaped stiffeners at the junction of CFT column and beam. The tensile loading tests of eighteen tee-joint connections and finite element analysis using ANSYS were carried out. The main parameters of tests are as follows: 1) the thickness of Square Steel Tubular Column : 6 mm, 9 mm, 2) the strength ratios of tensile strength of horizontal stiffeners to tensile strength of beam flange : 70 %, 100 %, 150 %, 3) the strength ratios of shear strength of vertical stiffeners to tensile strength of beam flange : 80 %, 115 %, 160 %. The results of the tests demonstrate that overall behavior and failure modes of all the specimens are governed mainly by the horizontal stiffeners rather than the vertical stiffeners, and the vertical stiffener played only a role in transferring load introduced from beam to column.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.45-51
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• 2004

We have proposed a new shallow trench isolation (STI) process using flowable oxide (F-oxide) chemical vapor deposition (CVD) for DRAM application and it was successfully developed. The combination of F-oxide CVD and HDP CVD is thought to be the superior STI gap-filling process for next generation DRAM fabrication because F-oxide not only improves STI gap-filling capability, but also the reduced local stress by F-oxide in narrow trenches leads to decrease in junction leakage and gate induced drain leakage (GIDL) current. Finally, this process increased data retention time of DRAM compared to HDP STI. However, a serious failure occurred by symphonizing its structural dependency of deposited thickness with poor resistance against HF chemicals. It could be suppressed by reducing the flow time during F-oxide deposition. It was investigated collectively in terms of device yield. In conclusion, the combination of F-oxide and HDP oxide is the very promising technology for STI gap filling process of sub-100nm DRAM technology.

• Reproductive and Developmental Biology
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• v.40 no.2
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• pp.23-26
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• 2016

Transcription factor called activating enhancer binding protein 2C (AP2-gamma) is found in a variety of species and expressed from oocyte stage onwards, particularly restricted to the trophectoderm. Recent studies demonstrated that ablation of Tfap2c led to failure of tight junction biogenesis, particularly the knock-down embryos of Tfap2c did not form cavity from morula to blastocyst in mouse and pig. We speculated that the Tfa2pc may also be involved in desmosome biogenesis because blastocoel formation is coincident with the establishment of desmosome. To determine this, we depleted Tfap2c injecting siRNA into one-cell zygote and analysed the expression levels of genes that are required for desmosome complex such as PkP2, Pkp3, Dsc2, and Dsg2. We found only Pkp3 was up-regulated in the knockdowned morula embryos. Interestingly, upstream region of Pkp3 had putative Tfap2c binding sites. In conclusion, our results suggest that Tfap2c is not a crucial factor but somehow it might be involved in desmosome biogenesis directly or indirectly via Pkp3.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.1
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• pp.189-196
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• 1991

This paper is an illustration of the application of the reliability analysis to the transverse structure of a SWATH ship. The ultimate strength of plate members on the cross structure and upper part of strut are considered in the reliability analysis. The fatigue reliability analysis has been also carried out at the junction of cross structure, sponsors and strut. Included is also an example of the allowable fatigue damage level. Demonstrated is the reliability study of series system of which elements are the ultimate and fatigue failure as well. Doing this would be desirable to get a truer solution of the structural safety level. The paper ends with a brief summary of the present reliability study and same important points which may be useful at the design stage.

• The Journal of the Korean dental association
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• v.48 no.4
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• pp.297-307
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• 2010

Noncarious cervical lesions(NCCLs) are characterized as structural defects found on the tooth surface of the cement-enamel junction. Loss of tooth structure through noncarious mechanisms may vary in etiology and clinical presentation for each individual but presently many clinician now classify this as tooth failure of abfraction due to the stress applied in the cervical area of the tooth under oral physiological and pathological loads. In the current study, we investigated the stress distribution of maxillary premolar with NCCL using simulated 3D finite element analysis. The results were as follows: 1. In the sound maxillary premolar, the stresses were highly concentrated at cervical enamel surface of the mesiobuccal line angle, asymmetrically. 2. Once the lesion has been formed, the highest stress concentration was observed around the apex of the wedge shaped lesion. 3. In four types of NCCL, the patterns of stress distribution were similar and the peak stress was observed at mesial corner and also stresses concentrated at lesion apex. 4. Lesion cavity modification of rounding apex, reduced stress of lesion apex. 5. When restoring the notch-shaped lesion, material with high elastic modulus worked well at the lesion apex and material with low elastic modulus worked well at the cervical cavosurface margin.

• Journal of Power Electronics
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• v.19 no.1
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• pp.307-315
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• 2019

Condition monitoring has been recognized as an effective and low-cost method to enhance the reliability and improve the maintainability of power electronic converters. In power electronic converters, high-frequency oscillation occurs during the switching transients of power transistors, which is known as ringing. The ringing frequency mainly depends on the values of the parasitic capacitance and stray inductance in the oscillation loop. Although circuit stray inductance is an important factor that leads to the ringing, it does not change with transistor aging. A shift in either the inside inductance or junction capacitance is an important failure precursor for power transistors. Therefore, ringing frequency can be used to monitor the health of power transistors. However, the switching actions of power transistors usually result in a dynamic behavior that can generate oscillation signals mixed with background noise, which makes it hard to directly extract the ringing frequency. A frequency extraction method based on empirical mode decomposition (EMD) and Fast Fourier transformation (FFT) is proposed in this paper. The proposed method is simple and has a high precision. Simulation results are given to verify the ringing analysis and experimental results are given to verify the effectiveness of the proposed method.

• Journal of Aerospace System Engineering
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• v.12 no.1
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• pp.57-67
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• 2018

The APD (Antenna Pointing Driver) is an electronic equipment tool that is used to drive the two-axis gimbal-type antenna for the image data transmission of CAS (Compact Advanced Satellite). In this study, a heat dissipation of EEE (Electrical, Electronic and Electromechanical) is reviewed, to identify the parts that directly affected its efficiency, lifetime as well as the reliability of the structure. This event eventually incurs a failure of the EEE part itself, or even the entire satellite system as noted in experiments in this case. To guarantee reliability of electronic equipment during the mission, the junction temperature of EEE parts is considered a significant and important design factor, and subsequently must be secured within the allowable range. Therefore, the notation of the thermal analysis considering the derating is indispensable, and a proper thermal mathematical model should be constructed for this case. In this study, the thermal design and thermal analysis are performed to confirm the temperature requirement of the APD. In addition, we noted that the validity of the thermal model, according to each of the identified modeling methods, was therefore compared through the thermal analysis utilized in this case.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.2
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• pp.220-227
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• 2017

Pre-eruptive intracoronal resorption (PEIR) is a rare radiolucent lesion often located within the dentin and adjacent to the dentin-enamel junction, underneath the occlusal aspect of the crowns of unerupted teeth. The treatment approaches for these lesions involved with unerupted teeth have been known as to be relatively simple; depending on the extent of resorption, follow-up or restoration can be performed after surgical exposure. However, once the tooth is exposed to the oral cavity after eruption, it becomes highly vulnerable to the development of carious lesions. Thus, immediate intervention is required in such cases; failure to address it may result in the need for more complex treatments including endodontic therapy. The aim of this case report was to describe the characteristics of PEIR and the clinical management of the impacted immature permanent teeth diagnosed with PEIR.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.696-703
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• 2014

Clostridium difficile causes mucosal damage and diarrhea by releasing two exotoxins: toxin A and toxin B. C. difficile colitis is associated with alterations in bowel flora and the failure to mount an effective antibody response. The aim of the current study was to investigate whether antitoxin sera prevent toxin-A-induced apoptosis, cytoskeletal disaggregation, cell detachment, and tight junction loss in cultured colonic epithelial cells. Serum samples were isolated from mice that survived a C. difficile infection following antibiotic treatment, and the antitoxin effects of these samples were investigated in toxin-A-exposed HT29 colonic epithelial cells and a toxin-A-induced animal model of gut inflammation. Unchallenged mice did not produce IgG against toxin A, whereas serum (antiserum) from C. difficile-challenged mice showed significant IgG responses against toxin A. Treatment with the antiserum markedly inhibited mucosal damage and inflammation in the toxin-A-treated mouse model. In contrast to control mouse serum, the antiserum also markedly inhibited toxin-A-induced DNA fragmentation, dephosphorylation of paxillin and Epo receptor (EpoR), deacetylation of tubulin, and upregulation of p21(WAF1/CIP1) and p53. Taken together, these results reveal that the generated antitoxin serum has biotherapeutic effects in preventing various C. difficile toxin-A-induced cellular toxicities.