• Mycobiology
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• v.49 no.5
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• pp.469-475
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• 2021

Three strains, YP416^T, YP421^T, and Y422, were isolated from soil samples in Pocheon City, Gyeonggi province, South Korea. The strains belong to two novel yeast species in the genus Mrakia. Molecular phylogenetic analysis showed that the strain YP416^T was closely related to Mrakia niccombsii. Still, it differed by 9 nucleotide substitutions with no gap (1.51%) in the D1/D2 domain of the LSU rRNA gene and 14 nucleotide substitutions with 7 gaps (2.36%) in the ITS region. The strain YP421^T differed from the type strain of the most closely related species, Mrakia aquatica, by 5 nucleotide substitutions with no gap (0.81%) in the D1/D2 domain of the LSU rRNA gene and 9 nucleotide substitutions with one gap (1.43%) in the ITS region. The names Mrakia terrae sp. nov. and Mrakia soli sp. nov. are proposed, with type strains YP416^T (KCTC 27886^T) and YP421^T (KCTC 27890^T), respectively. MycoBank numbers of the strains YP416^T and YP421^T are MB 836844 and MB 836847, respectively.

• Journal of Labour Economics
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• v.43 no.4
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• pp.1-34
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• 2020

After the global financial crisis, doubts have been raised about the usefulness of traditional unemployment rate for the labor market slackness, hence, this study provides alternative indicators that can help estimate the labor market slackness in Korea, and investigates the degree of biasness of traditional indices of Korean labor market. In particular, this study intends to focus on the possibility of employing the labor underutilization index officially announced by Statistics Korea (KOSIS) from 2015. To do this, we first define the labor underutilization indices from 2003 to 2014 by applying current definitions of labor underutilization indices retrospectively to these periods. Based on these indices, the empirical analysis shows that the employment gap using labor underutilization indices is highly correlated with total output gap, and has significantly improved the performance of forecasting inflation rate compared to other labor market slackness indicators.

• Explosives and Blasting
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• v.40 no.3
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• pp.33-43
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• 2022

In order to minimize the impact on the structure during an internal explosion, the explosives storage must be kept at a distance from the inner wall to prevent the sympathetic detonation of the others explosives in an unexpected explosion. For safe explosives storage, a gap test was conducted by simulating the split arrangement of explosives inside the storage. In this study, the separation distance and arrangement between the emulsion explosives were applied differently to be sympathetic detonation at 2D of diameter and non-detonated at 2.5D. Considering the coefficient of detonation transmission and the size of the explosives storage, the explosive amount of 3kg was set, and most of the gap tests according to various arrangement changes were non-detonated, and safety was confirmed when applying the batch.

• Analytical Science and Technology
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• v.20 no.1
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• pp.61-69
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• 2007

The geometrical parameters, total and relative energies, vibrational frequencies, the HOMO-LUMO energy gap, and reorganization energies for the neutral molecule, anion, and cation of $C_{16}H_{16}O_3$ have been determined using density functional method (DFT). The highest level of theory employed in this study is $B3LYP/6-311G^{**}$. Harmonic vibrational frequencies were determined at the $B3LYP/6-311G^{**}$ level of theory. All positive vibrational frequencies were obtained to confirm minimum structures. The HOMO-LUMO energy gap and reorganization energies were calculated to predict the charge transport property of liquid-crystal.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.699-705
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• 2015

Aircraft needs high lift-to-drag ratio and weight reduction of the structure for long endurance flight with a small power. Generally high aspect ratio wing is applied to HALE(High Altitude Long Endurance) aircraft. Also high modulus, and high strength CFRP(Carbon Fiber Reinforced Plastic) has been used in primary structures. and thin mylar(membrane material) film has been applied to skin of wing. As a result, wing is more flexible than the other structures. and the stiffness of thin mylar film has an affect on dynamic stability. In this study, the membrane characteristic of mylar film has been simulated using nonlinear gap elements. And equivalent modeling method using shell elements is presented using the nonlinear simulation result. The linear equivalent model has verified using the results of nonlinear membrane method. Proposed linear equivalent shell model has applied to mode analysis for estimate the effect of mylar mechanical properties on natural frequency.

• The Journal of Advanced Prosthodontics
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• v.15 no.3
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• pp.155-170
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• 2023

PURPOSE. This study aims to clinically compare the fitness and trueness of zirconia crowns fabricated by different combinations of open CAD-CAM systems. MATERIALS AND METHODS. Total of 40 patients were enrolled in this study, and 9 different zirconia crowns were prepared per patient. Each crown was made through the cross-application of 3 different design software (EZIS VR, 3Shape Dental System, Exocad) with 3 different processing devices (Aegis HM, Trione Z, Motion 2). The marginal gap, absolute marginal discrepancy, internal gap(axial, line angle, occlusal) by a silicone replica technique were measured to compare the fit of the crown. The scanned inner and outer surfaces of the crowns were compared to CAD data using 3D metrology software to evaluate trueness. RESULTS. There were significant differences in the marginal gap, absolute marginal discrepancy, axial and line angle internal gap among the groups (P < .05) in the comparison of fit. There was no statistically significant difference among the groups in terms of occlusal internal gap. The trueness ranged from 36.19 to 43.78 ㎛ but there was no statistically significant difference within the groups (P > .05). CONCLUSION. All 9 groups showed clinically acceptable level of marginal gaps ranging from 74.26 to 112.20 ㎛ in terms of fit comparison. In the comparison of trueness, no significant difference within each group was spotted. Within the limitation of this study, open CAD-CAM systems used in this study can be assembled properly to fabricate zirconia crown.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.705-715
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• 2021

Objective : Through our previous clinical trials, the demonstrated therapeutic effects of MSC in chronic spinal cord injury (SCI) were found to be not sufficient. Therefore, the need to develop stem cell agent with enhanced efficacy is increased. We transplanted enhanced Wnt3-asecreting human mesenchymal stem cells (hMSC) into injured spines at 6 weeks after SCI to improve axonal regeneration in a rat model of chronic SCI. We hypothesized that enhanced Wnt3a protein expression could augment neuro-regeneration after SCI. Methods : Thirty-six Sprague-Dawley rats were injured using an Infinite Horizon (IH) impactor at the T9-10 vertebrae and separated into five groups : 1) phosphate-buffered saline injection (injury only group, n=7); 2) hMSC transplantation (MSC, n=7); 3) hMSC transfected with pLenti vector (without Wnt3a gene) transplantation (pLenti-MSC, n=7); 4) hMSC transfected with Wnt3a gene transplantation (Wnt3a-MSC, n=7); and 5) hMSC transfected with enhanced Wnt3a gene (1.7 fold Wnt3a mRNA expression) transplantation (1.7 Wnt3a-MSC, n=8). Six weeks after SCI, each 5×10⁵ cells/15 µL at 2 points were injected using stereotactic and microsyringe pump. To evaluate functional recovery from SCI, rats underwent Basso-Beattie-Bresnahan (BBB) locomotor test on the first, second, and third days post-injury and then weekly for 14 weeks. Axonal regeneration was assessed using growth-associated protein 43 (GAP43), microtubule-associated protein 2 (MAP2), and neurofilament (NF) immunostaining. Results : Fourteen weeks after injury (8 weeks after transplantation), BBB score of the 1.7 Wnt3a-MSC group (15.0±0.28) was significantly higher than that of the injury only (10.0±0.48), MSC (12.57±0.48), pLenti-MSC (12.42±0.48), and Wnt3a-MSC (13.71±0.61) groups (p<0.05). Immunostaining revealed increased expression of axonal regeneration markers GAP43, MAP2, and NF in the Wnt3a-MSC and 1.7 Wnt3a-MSC groups. Conclusion : Our results showed that enhanced gene expression of Wnt3a in hMSC can potentiate axonal regeneration and improve functional recovery in a rat model of chronic SCI.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.656-664
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• 2014

The purpose of this study was to analyze myosin heavy chain (MHC) isoforms in bovine longissimus thoracis (LT) muscle by liquid chromatography (LC) and mass spectrometry (MS). LT muscles taken from Hanwoo (Korean native cattle) steer (n=3) used to separate myosin bands by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The peptide queries were obtained from the myosin bands by LC-MS/MS analysis following in-gel digestion with trypsin. A total of 33 and 43 queries were identified as common and unique peptides, respectively, of MHC isoforms (individual ions scores >43 indicate identity or extensive homology, p<0.05). MHC-1 (IIx), -2 (IIa), -4 (IIb), and -7 (slow/I) were identified based on the Mowse score (5118, 3951, 2526, and 2541 for MHC-1, -2, -4, and -7, respectively). However, more analysis is needed to confirm the expression of MHC-4 in bovine LT muscle because any query identified as a unique peptide of MHC-4 was not found. The queries that were identified as unique peptides could be used as peptide markers to confirm MHC-1 (14 queries), -2 (8 queries), and -7 (21 queries) in bovine LT muscle; no query identified as a unique peptide of MHC-4 was found. LC-MS/MS analysis is a useful approach to study MHC isoforms at the protein level.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.405-410
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• 2016

Auxins are essential in plant growth and development. The auxin-stimulated elongation of plant cells has been explained by the "acid-growth theory", which was proposed forty years ago. According to this theory, the auxin activates plasma membrane $H^+-ATPase$ to induce proton extrusion into the apoplast, promoting cell expansion through the activation of cell wall-loosening proteins such as expansins. Even though accepted as the classical theory of auxin-induced cell growth for decades, the major signaling components comprising this model were unknown, until publication of recent reports. The major gap in the acid growth theory is the signaling mechanism by which auxin activates the plasma membrane $H^+-ATPase$. Recent genetic, molecular, and biochemical approaches reveal that several auxin-related molecules, such as TIR1/AFB AUX/IAA coreceptors and SMALL AUXIN UP RNA (SAUR), serve as important components of the acid-growth model, phosphorylating and subsequently activating the plasma membrane $H^+-ATPase$. These researches reestablish the four-decade-old theory by providing us the detailed signaling mechanism of auxininduced cell growth. In this review, we discuss the recent research progress in auxin-induced cell elongation, and a set of possible future works based on the reestablished acid-growth model.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.350-355
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• 2009

Arachidonic acid (AA) is a polyunsaturated fatty acid that is a normal constituent of membrane lipids in animal cells. In addition to its role as a precursor of prostaglandins, AA itself may play an important role in the regulation of cell function. The effect of AA on functions of granulosa cells was investigated in pre-hierarchical small yellow follicles of laying hens. Immuno-cytochemical staining showed that AA ($10^{-7}-10^{-5}$ M) increased the expression of the extracellular matrix glycoprotein laminin, gap junction connexin 43 and protein kinase C (PKC). Therefore, mediated by the PKC signal pathway, AA may regulate the intercellular communication of granulosa cells and follicular development by increasing the expression of laminin and connexin.