• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.335-341
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• 2018

With the improvement of medical state, patients' expectations for the most advanced medical equipment are increasing. Particularly, Magnetic Resonance Image (MRI) is used as one of the core image diagnosis methods in all clinical area. However, it has been reported that many of patients who go through the examination suffer from anxiety to the severe noise level during the examination. In this study, both the noise reduction evaluation of headsets with sound-blocking materials added to existing sound-absorbing materials and the existence of sound blocking materials as artifacts on the examination image are tested. An MRI test noise is recorded as a speaker by cross-ordination the sound material (sponge) and the sound material (acrylic plate, copper plate, and 3D copper plate) inside the headset made from 3D pring. A quantitative assessment of headsets showed that the average headset value was 81.8 dB. The average dB value of the most soundproof material combination(Copper, acrylic plate, sponge, sponge) headsets on headsets with added charactering material was measured at 70.4 dB, and MRI showed that the copper was diamagnetic substance and excluded. The second most soundproof headset(Sponge, acrylic plate, 3D copper plate, sponge) was measured at 70.6 dB and MRI showed no artifacts. The same simulation of the material printed with a 3D copper PLA containing approximately 40 % copper powder resulted in no artifacts, therefore, the material output as a 3D printing was better suited for use. For MRI related research, the mutual development of 3D printing is highly anticipated.

• Biomolecules & Therapeutics
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• v.31 no.3
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• pp.330-339
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• 2023

Liver kinase B1 (LKB1) is a crucial tumor suppressor involved in various cellular processes, including embryonic development, tumor initiation and progression, cell adhesion, apoptosis, and metabolism. However, the precise mechanisms underlying its functions remain elusive. In this study, we demonstrate that LKB1 interacts directly with malic enzyme 3 (ME3) through the N-terminus of the enzyme and identified the binding regions necessary for this interaction. The binding activity was confirmed to promote the expression of ME3 in an LKB1-dependent manner and was also shown to induce apoptosis activity. Furthermore, LKB1 and ME3 overexpression upregulated the expression of tumour suppressor proteins (p53 and p21) and downregulated the expression of antiapoptotic proteins (nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and B-cell lymphoma 2 (Bcl-2)). Additionally, LKB1 and ME3 enhanced the transcription of p21 and p53 and inhibited the transcription of NF-κB. Moreover, LKB1 and ME3 suppressed the phosphorylation of various components of the phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B signaling pathway. Overall, these results suggest that LKB1 promotes pro-apoptotic activities by inducing ME3 expression.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.47-53
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• 1993

Antibiotics KG-431A and KG-431B were isolated from the fermentation broth of the Clostridium sp. KH-431. As we have shown previously, only KG-431B was successful to recrystallize. These antibiotics showed antimicrobial activities against broad spectrum of bacteria and fungi. KG-431B also showed anticancer activity against some animal tumor cells according to the SRB method. Physico-chemical properties of KG-431B were determined using UV, IR, NMR and Mass spectra. It was identified to be 3-Indole propionic acid and the structure of the KG-431A is currently under investigation.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1053-1058
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• 2021

This paper presents the multi-band mixer which converts a X-, K- and Ka-band adaptively by adjusting the gate-bias voltage of an active device. The proposed mixer presented a conversion loss of -10 dB at -0.8 V gate-bias voltage for X-band, a conversion loss of -9 dB at -0.3 V gate-bias voltage for K-band and for Ka-band, a conversion loss of -7 dB at -0.2 V gate-bias voltage under the LO power of +6.0 dBm. The 1dB compression point (P1dB) is +0.5 dBm for all band.

• YAKHAK HOEJI
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• v.39 no.2
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• pp.205-209
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• 1995

Methylene protons of benzyl and ethyl ester in ethyl 1-benzyl-2, 3-dioxo-cyclopenta[b]-pyrrole-3a-carboxylate (A) exhibited opposite$^{1}$H-NMR spectral patterns mutually between magnetic equivalence and nonequivalence depending on concentration and temperature. The diastereotopic spectral data of compound A were reported with brief interpretation.

• Korean Journal of Radiology
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• v.22 no.9
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• pp.1525-1536
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• 2021

Objective: To investigate the feasibility of cine three-dimensional (3D) balanced steady-state free precession (b-SSFP) imaging combined with a non-local means (NLM) algorithm for image denoising in evaluating cardiac function in children with repaired tetralogy of Fallot (rTOF). Materials and Methods: Thirty-five patients with rTOF (mean age, 12 years; range, 7-18 years) were enrolled to undergo cardiac cine image acquisition, including two-dimensional (2D) b-SSFP, 3D b-SSFP, and 3D b-SSFP combined with NLM. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and ejection fraction (EF) of the two ventricles were measured and indexed by body surface index. Acquisition time and image quality were recorded and compared among the three imaging sequences. Results: 3D b-SSFP with denoising vs. 2D b-SSFP had high correlation coefficients for EDV, ESV, SV, and EF of the left (0.959-0.991; p < 0.001) as well as right (0.755-0.965; p < 0.001) ventricular metrics. The image acquisition time ± standard deviation (SD) was 25.1 ± 2.4 seconds for 3D b-SSFP compared with 277.6 ± 0.7 seconds for 2D b-SSFP, indicating a significantly shorter time with the 3D than the 2D sequence (p < 0.001). Image quality score was better with 3D b-SSFP combined with denoising than with 3D b-SSFP (mean ± SD, 3.8 ± 0.6 vs. 3.5 ± 0.6; p = 0.005). Signal-to-noise ratios for blood and myocardium as well as contrast between blood and myocardium were higher for 3D b-SSFP combined with denoising than for 3D b-SSFP (p < 0.05 for all but septal myocardium). Conclusion: The 3D b-SSFP sequence can significantly reduce acquisition time compared to the 2D b-SSFP sequence for cine imaging in the evaluation of ventricular function in children with rTOF, and its quality can be further improved by combining it with an NLM denoising method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.181-187
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• 1996

본 연구에서는 비타민 $B_{2}$ 결핍이 3일간 금식과 6일간 감식시 체내 저장연료 이용에 어떠한 영향을 미치는 가를 알아본 결과, -B2군은 pair-feeding을 감식시켰음에도 불구하고 +B2군에 비해 체중이 유의적으로 낮게 나타났으며 식이 이용효율도 낮았다. 모든 장기, 특히 간장 무게는 -B2군이 +B2군에 비해 무겁게 나타났으며, 감식과 금식시에도 -B2군의 장기무게가 가벼워졌으나 여전히 유의하게 무거웠으며 -B2군의 간장 중성 지방이 높게 나타나 지방간 증상으로 간장이 비대해진 것으로 추정된다. 혈장 포도당과 단백질 함량은 섭식, 금식 및 감식시 +B2군과 -B2군 사이에 유의적인 차이가 없었다. 혈장 중성지방 수준은 +B2군에 비해 -B2군이 섭식시는 높은 수준을 나타냈으나 금식 및 감식시에는 유의적인 차이를 나타내지 않았다. 간장 중성 지방도 이와 유사한 경향을 나타내었다. 혈장 유리지방산 수준은 섭식시에는 +B2군과 -B2군 사이에 유의적인 차이가 없었으나, 금식으로 인해 +B2군은 유리지방산 수준이 증가하였고 -B2군은 오히려 감소하여 -B2군이 +B2군 보다 낮게 나타났다. 그러므로 비타민 $B_{2}$ 결핍으로 인해 이 유리지방산의 유리가 원활히 일어나지 않았거나, 비타민 $B_{2}$ 결핍으로 인해 지방산화가 저해된 것이 금식으로 지방이 에저지원으로 이용되어야만 하는 상황이 발생하여 감소된 지방산 산화가 다소 회복된 것으로 추정된다. 금식 및 감식시 +B2군에 비해 -B2군이 근육단백질 수준은 높은 경향을 나타내었고 근육 글리코겐 수준은 낮은 경향을 나타내어 -B2군이 심각한 비타민 $B_{2}$ 결핍으로 저지방이나 근육단백질을 이용하지 못하게 됨에 따라 근육 글리코겐을 이용한 것으로 추정된다. 이는 +B2군에 비해 -B2군의 뇨중 총질소 배설량이 적은 것으로도 재확인되었다. 그러므로 금식이나 감식시 체지방이나 체단백질을 이용하는 에너지 보충 적응기전이 일어나야 하나 비타민 $B_{2}$ 결핍상태에서는 이러한 체내 열량공급이 지장을 받게 되며, 체단백질 이용저하로 포도당 신생이 영향을 받아 장기간의 금식 또는 감식시에는 혈장 포도당 수준도 낮아질 것으로 예상된다.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.566-573
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• 2017

The study was conducted to evaluate the growth performance, viability, and uniformity of female crossbred Korean native chickens (KNC) for the first twelve weeks after hatching. Six crossbreed lines of chickens (1B, 2B, 3B, 4B, 5B, and 6B) bred from 1 paternal line and 6 maternal lines of KNC were compared in this study. Sixty newly hatched 1-day old chicks from each crossbreed, for a total of 360 chickens, were allocated into 6 replicates (10 birds per replicate) in a complete randomized design. Experimental diets used in this study consisted of 3 phases: 1) week 0 to 5, crude protein 20.3% and metabolizable energy 3,059 kcal/kg; 2) week 5 to 8, crude protein 18.6% and metabolizable energy 3,123 kcal/kg; and 3) week 8 to 12, crude protein 16.7% and metabolizable energy 3,187 kcal/kg. Body weight and feed intake were measured bi-weekly during the experiment. The 4B crossbreed had a higher body weight, average daily gain, and average daily feed intake on week 12 (p < 0.05) than the other groups. The 4B crossbreed had a lower (p < 0.05) uniformity during weeks 10 to 12 than crossbreeds 1B and 5B. However, a lower viability was observed (p > 0.05) in 4B in weeks 2 to 12 than those in the other groups. Results of the current study indicate that the 4B crossbreed had a higher growth performance in week 12 but had a lower viability for weeks 2 to 12 than the other crossbreeds.

• Journal of Preventive Medicine and Public Health
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• v.7 no.1
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• pp.177-183
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• 1974

It is generally recognized that the environmental noise of the various working places thought to be the cause of hearing disturbance. This survey was carried out to evaluate the prevalence of noise-induced occupational bearing loss among the weavers of 39 textile industries in Taegu, Korea. For this survey, 432 male workers and 2,023 female workers were examined their hearing acuity by Individual pure tone threshold determination test(air conduction), from November, 1972, to January, 1973. Main findings were as follows : 1. The mean of noise intensity of the 54 weaving rooms was, in over all, $95.6{\pm}4.2dB\;(A),\;95.9{\pm}4.0dB\;(B)\;and\;96.2{\pm}3.9dB\;(C)$. 2. The mean hearing threshold levels by service years in the 4,000 Hz were intensively increased from 1st to 3rd year and slightly decreased. than that of 3rd year, from after 3rd to 5th year, after 5th year that increased slightly. 3. The mean hearing threshold levels by frequencies were highest in the 4,000 Hz(male: $25.0{\pm}11.3dB$, female: $22.0{\pm}10.2dB$) and followed by 6,000, 8,000 and 3,000 Hz. 4. The mean hearing threshold level of the 6,000 Hz (male: 17.0 dB. female: 17.9dB) was higher than that of 4,000Hz (male: 16.4 dB, female: 17.1dB) in tile 1st service year. 5. The mean hearing loss of examinees was $16.2{\pm}8.0dB$ in male and $15.4{\pm}7.8dB$ in female.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.267-276
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• 2020

T In the present study, we investigated the effect of oncogenic H-Ras on rat mdr1b expression in NIH3T3 cells. The constitutive expression of H-Ras^V12 was found to downregulate the mdr1b promoter activity and mdr1b mRNA expression. The doxorubicin-induced mdr1b promoter activity of the H-Ras^V12 expressing NIH3T3 cells was markedly lower than that of control NIH3T3 cells. Additionally, there is a positive correlation between the level of H-Ras^V12 expression and a sensitivity to doxorubicin toxicity. To examine the detailed mechanism of H-Ras^V12-mediated down-regulation of mdr1b expression, antioxidant N-acetylcysteine (NAC) and NADPH oxidase inhibitor diphenylene iodonium (DPI) were used. Pretreating cells with either NAC or DPI significantly enhanced the oncogenic H-Ras-mediated down-regulation of mdr1b expression and markedly prevented doxorubicin-induced cell death. Moreover, NAC and DPI treatment led to a decrease in ERK activity, and the ERK inhibitors PD98059 or U0126 enhanced the mdr1b-Luc activity of H-Ras^V12-NIH3T3 and reduced doxorubicin-induced apoptosis. These data suggest that Ras^V12 expression could downregulate mdr1b expression through intracellular reactive oxygen species (ROS) production, and ERK activation induced by ROS, is at least in part, contributed to the downregulation of mdr1b expression.