• Kosin Medical Journal
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• v.33 no.3
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• pp.369-379
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• 2018

Objectives: Analysis of heart rate variability (HRV) has been used as a measure of cardiac autonomic function. According to the pNN50 statistic, the percentage of differences between successive normal RR intervals (RRI) that exceed 50 ms, has been known to reflect cardiac vagal modulation. Relatively little is known about the validity of pNN50 during general anesthesia (GA). Therefore, we evaluated the correlation of pNN50 with other variables such as HF, RMSSD, SD1 of HRV reflecting the vagal tone, and examined the validity of pNN50 in anesthetized patients. Methods: We assessed changes in RRI, pNN50, root mean square of successive differences of RRI (RMSSD), high frequency (HF) and standard deviation 1 (SD1) of $Poincar{\acute{e}}$ plots after GA using sevoflurane anesthesia. We also calculated the probability distributions for the family of pNNx statistics (x: 2-50 ms). Results: All HRV variables were significantly decreased during GA. HF power was not correlated with pNN50 during GA (r = 0.096, P = 0.392). Less than pNN47 was shown to have a correlation with other variables. Conclusions: These data suggest that pNN50 can not reflect the level of vagal tone during GA.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.55-62
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• 2021

This study aims to reduce the rancid odor generated during the fermentation process of kimchi by inserting zinc oxide (ZnO) into an inorganic porous material with a high surface area to decompose or adsorb the fermentation odor. ZnO activated by the presence of moisture exhibits decomposition of rancid odors. Mixed with Titanium dioxide (TiO₂), a photocatalyst. To manufacture the packaging liner used in this study, NaOH, ZnCl₂, and TiO₂ powder were placed in a tank with diatomite and water. The sludge obtained via a hydrothermal ultrasonication synthesis was sintered in an oven. After being pin-milled and melt-blended, the powders were mixed with linear low-density polyethylene (L-LDPE) to make a masterbatch (M/B), which was further used to manufacture liners. A gas detector (GasTiger 2000) was used to investigate the total amount of sulfur compounds during fermentation and determine the reduction rate of the odor-causing compounds. The packaging liner cross-section and surface were investigated using a scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS) to observe the adsorption of sulfur compounds. A variety of sulfur compounds associated with the perceived unpleasant odor of kimchi were analyzed using gas chromatography-mass spectrometry (GC-MS). For the analyses, kimchi was homogenized at room temperature and divided into several sample dishes. The performance of the liner was evaluated by comparing the total area of the GC-MS signals of major off-flavor sulfur compounds during the five days of fermentation at 20℃. As a result, Nano-grade inorganic compound liners reduced the sulfur content by 67 % on average, compared to ordinary polyethylene (PE) foam liners. Afterwards SEM-EDS was used to analyze the sulfur content adsorbed by the liners. The findings of this study strongly suggest that decomposition and adsorption of the odor-generating compounds occur more effectively in the newly-developed inorganic nanocomposite liners.

• Advances in concrete construction
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• v.14 no.1
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• pp.1-13
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• 2022

Due to the physical-chemical characteristics of some bottom ash (BA), there are technical, economic and environmental limitations to find a destination that will add value to it. In Brazil, this residue is eventually used for filling coal extraction pits or remains in sedimentation ponds, creating a susceptible panorama to environmental issues. The geopolymers binders are one of the alternatives to the proper use high amounts of these materials. In this work, geopolymeric binder pastes were produced with BA mixed to activators with different alkali contents (expressed as %Na₂O), as well as the incorporation of soluble silicates (Ms content). The production of binary geopolymeric pastes based on the use of two industrial wastes: fluid catalytic cracking (FCC) and aluminum anodizing sludge (AAS), was also assessed. The content in mass of BA/FCC and BA/AAS ranged from 100/0, 90/10; 80/20 and 70/30. Systems with soluble silicates as activator in a molar ratio SiO₂/Na₂O of 1.0 (Ms = 1.0) and Na₂O content of 15%, showed the best results of mechanical strength (42 MPa at day 28^th). The improvement is up to 5X when compared to NaOH based systems. For systems with partial replacement of BA of 10% of AAS and 20% of FCC (80/20), the presence of soluble silicates was also effective to increase compressive strength.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1029-1039
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• 2024

This study explores beneficial bacteria isolated from the roots and rhizosphere soil of Khao Rai Leum Pua Phetchabun rice plants. A total of 315 bacterial isolates (KK001 to KK315) were obtained. Plant growth-promoting traits (phosphate solubilization and indole-3-acetic acid (IAA) production), and antimicrobial activity against three rice pathogens (Curvularia lunata NUF001, Bipolaris oryzae 2464, and Xanthomonas oryzae pv. oryzae) were assessed. KK074 was the most prolific in IAA production, generating 362.6 ± 28.0 ㎍/ml, and KK007 excelled in tricalcium phosphate solubilization, achieving 714.2 ± 12.1 ㎍/ml. In antimicrobial assays using the dual culture method, KK024 and KK281 exhibited strong inhibitory activity against C. lunata, and KK269 was particularly effective against B. oryzae. In the evaluation of antimicrobial metabolite production, KK281 and KK288 exhibited strong antifungal activities in cell-free supernatants. Given the superior performance of KK281, taxonomically identified as Bacillus sp. KK281, it was investigated further. Lipopeptide extracts from KK281 had significant antimicrobial activity against C. lunata and a minimum inhibitory concentration (MIC) of 3.1 mg/ml against X. oryzae pv. oryzae. LC-ESI-MS/MS analysis revealed the presence of surfactin in the lipopeptide extract. The crude extract was non-cytotoxic to the L-929 cell line at tested concentrations. In conclusion, the in vitro plant growth-promoting and disease-controlling attributes of Bacillus sp. KK281 make it a strong candidate for field evaluation to boost plant growth and manage disease in upland rice.

• Journal of the Korea Society of Computer and Information
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• v.29 no.8
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• pp.43-51
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• 2024

This paper proposes a method for acquiring and analyzing ocular data using a special-purpose diver mask targeted at divers who primarily engage in underwater activities. This involves tracking the user's gaze with the help of a custom-built ocular dataset and a YOLOv8-nano model developed for this purpose. The model achieved an average processing time of 45.52ms per frame and successfully recognized states of eyes being open or closed with 99% accuracy. Based on the analysis of the ocular data, a gaze tracking algorithm was developed that can map to real-world coordinates. The validation of this algorithm showed an average error rate of about 1% on the x-axis and about 6% on the y-axis.

• Investigative Magnetic Resonance Imaging
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• v.3 no.2
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• pp.146-153
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• 1999

Purpose : To evaluate the proton MR spectroscopy (MRS) findings of early and late ischemic infarcts and to compare these MRS findings with clinical symptoms. Materials and Methods : We obtained MRs spectra of 28 consecutive patients with early ischemic infarct (15 me, 13 women) between 2-10 (mean 6.2) days after stroke onset. Follow-up MRS was carried out between 20-32 (mean 25) days in 12 patients. The MRs spectra were acquired at 1.5T MR unit using single voxel technique with PRESS sequence, TR of 2000ms, TE of 288 (144)ms, and voxel size of 2cm x 2cm x 2cm in the three areas; an infarct lesion, the brain parenchyma adjacent to the lesion, and contralateral normal brain parenchyma. The NAA/creatine, choline/creatine, and lactate/creatine ratios were calculated in each spectrum. The spectra of MRS were compared with clinical symptoms. Results : In early infarct, decreased NAA/creatine ratio (n=22) and increased lactate/creatine ratio (n=25) were found in the infarct lesion. Choline/creastine ratio was within normal range (n=25). On follow-up MRS in late stage, NAA/creatine ratio in the infarct lesion decreased further (n=5), did not change (n=6), or increased (n=1). Lactate/creatine ratio became less elevated (n=10), or did not changed (n=2). Choline/creatine ratio had a trend for increase. The decreased NAA/creatine and increased lactate/creatine ratios were correlated well with the severity of symptoms, respectively. Conclusion : Decreased NAA/creatine and increased lactate/creatine ratios were common MRS findings characteristic in early ischemic infarct and correlated well with clinical severity. On follow-up MRS in late stage, NAA/creatine ratio decreased further or did not change, and lactate/creatine ratio became less elevated.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.6
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• pp.229-236
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• 2014

A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.104-112
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• 1998

Purpose : To evaluate the clinical utility of diffusion-weighted imaging by analyzing the signal intersity of lesions in patients with various intracranial diseases. Materials and Methods : difusion-weighted MR imaging was prospectively perormed in randomly selected 70 patients with various intracranial idseases. They consisted of 20 patients with acute infarct, 21 patients with chronic infarct of small vessel disease, 14 patients with primary intracranial tumor, three patients with brain metastasis, five patient with brain abscess, five patients with brain abscess, five patients with cerebral hemorrhage, one patient with neurocysticercosis, and one patient with epidermoid cyst. the diffusion-weighted images were obtained immediately after routine T2-weighted imaging on a 1.5T MR unit using single shot spin echo EPI technique with 6500 ms TR, 107ms TE, $128{\times}128$ matrix, 1 number of excitation, $24{\times}24$ field of view, 5-7 mm slice thickness, 2-3 mm inter-slice gap. The diffusion-gradients (b value of ($1000s{\;}/{\;}textrm{mm}^2$)) were applied along three directions(x, y, z). On visual inspection of diffusion-weighted images, the signal intersity of lesions was arbitrarily graded as one of 5 grades. In quantitative assessment, we measured the signal intensity of all the lesions and the contralateral corresponding normal area using round region of interest(ROI), and then calculated the signal intensity ratio of the lesion to the normal brain parenchyma. Results : On visual inspection, markedly hyperintense signals were seen in all cases of acute infarct, brain abscess, epidermoid cyst, and neurocysticercosis in degenerating stage. In all cases of cerebral hematoma, the very high signal internsity was intermingled with low signal intensity. focal very high signal intersity was also seen in a solid portion of the tumor in a patient. the mean signal intensity ratios of all those lesions to the normal brain parenchyma were above 2.5. Gliosis, solid component of brain tumor, brain metastasis, and vasogenic dedma appeared isointense to the normal brain parenchyma in 71%, 64%, 100%, and 67%, respectively ; the mean signal intensity ratios of those lesions to the normal brain parenchyma ranged 1.15 to 1.28 and there was no significant difference among these(p>0.1). Cystic cerebromalacia and necrotic or cystic portions in tumor were markedly or slightly hypointense, and the mean signal intensity ratios were 0.45 and 0.42, respectively. Conclusion : Very high signal intensity of acute infarct, brain abscess, epidermoid cyst, and cystic neurocysticercosis in degenerating stage on diffusion-weighted images may be helpful in differentiating from other diseases that are hypointense or isointense to the normal brain parenchyma. It may be especially useful differentiation of brain abscess from brain tumor with necrotic or cystic portion.

• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.328-336
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• 1997

The CdSe thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). The source and substrate temperature are $600^{\circ}C$ and $430^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the temperature range 30K to 150K by impurity scattering and decreased in the temperature range 150k to 293k by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity(${\gamma}$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.39{\times}10^{7}$, the MAPD of 335mW, and the rise and decay time of 10ms and 9.5ms, respectively.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.546-554
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• 2006

To understand antitumor activity of Zanthoxylum schinfolium, which has been used as an aromatic and medicinal plant in Korea, the cytotoxic effect of various organic solvent extracts of its leaves on human tumor cells were investigated. Among these extracts such as methanol extract (SL-13), methylene chloride extract (SL-14), ethyl acetate extract (SL-15), n-butanol extract (SL-16), and residual fraction (SL-17), SL-14 appeared to contain the most cytotoxic activity against leukemia and breast cancer cells tested. The methylene chloride extra.1 (SL-14) possessed an apoptogenic activity causing apoptotic DNA fragmentation of human acute leukemia Jurkat T cells via mitochondrial cytochrome c release into cytoplasm, subsequent activation of caspase-9 and caspase-3, and cleavage of PARP, which could be negatively regulated by antiapoptotic protein Bcl-xL. The GC-MS analysis of SL-14 revealed that the twenty-two ingredients of SL-14 were 9,19-cyclolanost-24-en-3-ol (15.1%), 2-a-methyl-17, b-hop-21-ene (15.1%), 15-methyl-2,3-dihydro-1H benzazepin (11.95%), phytol (10.38%), lupeol (9.92%), 12-methylbenzofuran (8.23%), hexadecanoic acid (5.96%), cis,cis,cis-9,12,15-octadecatrienoic acid-methyl-ester (5.49%), 9,12,15-octadecatrienoic acid-methylester (3.59%), 15-methyl-4-(1-methylethylidene)-2-(4-nitrophenyl) (3.36%), hexadecanoic acid methyl ester (1.93%), vitamine E (1.88%), beta-amyrin (0.96%), and auraptene (0.89%). These results demonstrate that the cytotoxicity of the methylene chloride extract of the leaves of Z. schinifolium toward Jurkat T cells is mainly attributable to apoptosis mediated by mitochondria-dependent caspase cascade regulated by Bcl-xL, and provide an insight into the mechanism underlying antitumor activity of the edible plant Z. schinifolium.