• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1366-1372
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• 2021

Bacterial nanocellulose (BNC) is a biocompatible material with a lot of potential. To make BNC commercially feasible, improvements in its production and surface qualities must be made. Here, we investigated the in situ fermentation and generation of BNC by addition of different cellulosic substrates such as Avicel and carboxymethylcellulose (CMC) and using Komagataeibacter sp. SFCB22-18. The addition of cellulosic substrates improved BNC production by a maximum of about 5 times and slightly modified its structural properties. The morphological and structural properties of BNC were investigated by using Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy and X-ray diffraction. Furthermore, a type-A cellulose-binding protein derived from Clostridium thermocellum, CtCBD3, was used in a novel biological analytic approach to measure the surface crystallinity of the BNC. Because Avicel and CMC may adhere to microfibrils during BNC synthesis or crystallization, cellulose-binding protein could be a useful tool for identifying the crystalline properties of BNC with high sensitivity.

• 한국초전도ㆍ저온공학회논문지
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• 제23권4호
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• pp.30-34
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• 2021

Superconducting magnets have paved the way for opening new horizons in designing an electromagnet of a high field magnetic resonance imaging (MRI) device. In the first phase of the superconducting MRI magnet era, low-temperature superconductor (LTS) has played a key role in constructing the main magnet of an MRI device. The highest magnetic resonance (MR) field of 11.7 T was indeed reached using LTS, which is generated by the well-known Iseult project. However, as the limit of current carrying capacity and mechanical robustness under a high field environment is revealed, it is widely believed that commercial LTS wires would be challenging to manufacture a high field (>10 T) MRI magnet. As a result, high-temperature superconductor together with the conducting cooling approach has been spotlighted as a promising alternative to the conventional LTS. In 2020, the Korean government launched a national project to develop an HTS magnet for a high field MRI magnet as an extent of this interest. We have performed a design study of a 7 T 320 mm winding bore HTS MRI magnet, which may be the ultimate goal of this project. Thus, in this paper, design study results are provided. Electromagnetic design and analysis were performed considering the requirements of central magnetic field and spatial field uniformity.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.617-624
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• 2019

Bacterial nanocellulose (BNC) which is generally synthesized by several species of bacteria has a wide variety of industrial uses, particularly in the food and material industries. However, the low levels of BNC production during the fermentation process should be overcome to reduce its production cost. Therefore, in this study, we screened and identified a new cellulose-producing bacterium, optimized production of the cellulose, and investigated the morphological properties of the cellulosic materials. Out of 147 bacterial isolates from ripened fruits and traditional vinegars, strain SFCB22-18 showed the highest capacity for BNC production and was identified as Komagataeibacter sp. based on 16S rRNA sequence analysis. During 6-week fermentation of the strain using an optimized medium containing 3.0% glucose, 2.5% yeast extract, 0.24% acetic acid, 0.27% $Na_2HPO_4$, and 0.5% ethanol at $30^{\circ}C$, about 5 g/l of cellulosic material was produced. Both imaging and IR analysis proved that the produced cellulose would be nanoscale bacterial cellulose.

• 한국항공우주학회지
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• 제47권4호
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• pp.274-282
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• 2019

무인항공기의 영상 기반 항법은 널리 사용되는 GPS/INS 통합 항법 시스템의 취약점을 보강할 수 있는 중요한 기술로 이에 대한 연구가 활발히 이루어지고 있다. 하지만 일반적인 영상 대조 기법은 실제 항공기 비행 상황들을 적절하게 고려하기 힘들다는 단점이 있다. 따라서 본 논문에서는 영상기반 항법을 위한 가우시안 혼합 모델 기반의 파티클 필터를 제안한다. 제안한 파티클 필터는 영상과 데이터베이스를 가우시안 혼합 모델로 가정하여 둘 간의 유사도를 이용하여 항체의 위치를 추정한다. 또한 몬테카를로 시뮬레이션을 통해 위치 추정 성능을 확인한다.

• Journal of Chest Surgery
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• 제51권6호
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• pp.410-414
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• 2018

Primary pulmonary meningioma is a rare disease, and chordoid meningioma is an uncommon variant of meningioma in the central nervous system (CNS) with a high recurrence rate. We report a case of primary pulmonary chordoid meningioma that presented as a solitary pulmonary nodule (SPN). The SPN was resected by thoracoscopic wedge resection and was revealed to have characteristics of chordoid meningioma. After confirming the absence of a meningioma in the CNS by brain imaging, the nodule was diagnosed as a primary pulmonary chordoid meningioma. The patient remained disease-free after 26 months postoperatively. To our knowledge, this is the third case of primary pulmonary chordoid meningioma to be reported.

• PNF and Movement
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• 제17권2호
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• pp.189-197
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• 2019

Purpose: The aim of our study was to evaluate the therapeutic effects of walking and turning plus treadmill training on the functional balance and walking ability of individuals with Parkinson's disease (PD). Methods: Twenty-four participants with Stage 1 to 3 ($2.13{\pm}0.64$) PD based on the Hoehn and Yahr scale were randomly allocated to the experimental group (EG) and control group (CG), with 12 participants in each group. The measured outcomes included the motor subscale of the unified Parkinson's disease rating scale (UPDRS-M), the Berg balance scale (BBS), the Timed Up and Go (TUG) test, the 10-meter walk test (10MWT), and the 6-minute walk test (6MWT). Results: Pre-to-post intervention improvements were noted for all the outcome measures for both groups (p < 0.05). Post intervention, there was a significant improvement in the EG compared to the CG for the following measured outcomes (p < 0.05): UPDRS-M (p = 0.021; 95% CI, 0.081-6.519), BBS (p = 0.042; 95% CI, 1.375-4.541), TUG (p = 0.034; 95% CI, -3.315--0.143), 10MWT (p = 0.011; 95% CI, -2.032--0.289), and 6MWT (p = 0.002; 95% CI, 24.39-91.273). Conclusion: Our study suggests that walking and turning plus treadmill training improves balance and walking compared to treadmill training only in patients with PD.

• Journal of Medicine and Life Science
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• 제16권2호
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• pp.43-45
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• 2019

Intraoperative delivery of salbutamol (${\beta}_2$ agonist) through a breathing circuit may be performed in asthma patient. A 28-year-old woman with a history of asthma was diagnosed with chronic sinusitis and bilateral nasal polyps, and an endoscopic sinus surgery was performed. The patient was recommended salbutamol nebulization every 4 hours during the perioperative period because of the risk of asthma attack. At the end of the operation, when salbutamol was sprayed through the tube before extubation and the connector tip went inside the tube during injection. The patient was immediately referred to the pulmonary medicine department for bronchoscopy, where the foreign body was removed safely without any complications. When general anesthesia is performed on a patient who usually uses an inhaler for asthma, caution is required because the tip that connects the inhaler and the breathing circuit can aspirate into the endotracheal tube and enter the lungs when applying the inhaler before waking up the patient.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.11-18
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• 2017

The safety inspection cost of the construction work was based on commercial facilities classified as a single building. Therefore, it is not possible to fully reflect the characteristics of the multi-building construction project such as apartment houses. Therefore, this study suggests a reasonable estimation model that can fully reflect the characteristics of the multi-building construction project. The safety inspection cost estimation model proposed two models such as construction cost ratio method and cost plus fixed fee method. And these models were simulated by the apartment construction work and compared with the current standard. As a result, the current construction cost ratio method has shown that the safety inspection cost tends to be overestimated as the construction size increases. Therefore, the proposed model has reflected characteristics of the multi-building construction project, so that it can reasonably estimate the safety inspection cost more than the current standard.

• 한국양봉학회지
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• 제34권4호
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• pp.325-328
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• 2019

We investigated the food storage stability of propolis extracts using homemade meatballs. Propolis extracts were prepared by using the ethanol extraction method. After making the meatballs, propolis was mixed into the meatball materials and egg water with a final concentration of 1% v/v. Microbial cultivation results showed that the cultivation of Staphylococcus aureus, which is one of the food poisoning bacteria, was reduced by more than 90% and the period of storage was 1.5 times longer. Also, it was observed to be effective when propolis was added to meatballs, it was even more effective when propolis was mixed with egg water. Thus, propolis extracts may be a useful ingredient for food storage stability due to its anti-microbacterial function.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.152-161
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• 2022

We analyzed mitigation strategies for steam generator tube rupture (SGTR) accidents using MARS code under both full-power and low-power and shutdown (LPSD) conditions. In general, there are two approaches to mitigating SGTR accidents: supplementing the reactor coolant inventory using safety injection systems and depressurizing the reactor coolant system (RCS) by cooling it down using the intact steam generator. These mitigation strategies were compared from the viewpoint of break flow from the ruptured steam generator tube, the core integrity, and the possibility of the main steam safety valves opening, which is associated with the potential release of radiation. The "cooldown strategy" is recommended for break flow control, whereas the "RCS make-up strategy" is better for RCS inventory control. Under full power, neither mitigation strategy made a significant difference except for on the break flow while, in LPSD modes, the RCS cooldown strategy resulted in lower break and discharge flows, and thus less radiation release. As a result, using the cooldown strategy for an SGTR under LPSD conditions is recommended. These results can be used as a fundamental guide for mitigation strategies for SGTR accidents according to the operational mode.