• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.206-219
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• 2013

This study aims to estimate firing temperature and physicochemical properties of the four clay bricks excavated from the Maritime Province of Siberia. Analysis result shows that the specimens are composed of clay, quartz and feldspar, and some specimens include carbonized organic materials which were probably added in order to enhance its physical strength in bricks. Major mineral components of the bricks are quartz, illite and clay minerals. The result identifying the existence of silimanite by XRD suggests that white material of the Koc 1 was painted for a certain purpose. Unlike most specimens which contained hematite, several samples contain Mullite. Such result suggests that some bricks were fired at high temperature. Furthermore, the results from TG analysis which does not display exothermic peak which appears at between $800^{\circ}C$ to $1,000^{\circ}C$ but display endothermic peak at $900^{\circ}C$ and it also confirms that they were exposed at $900^{\circ}C$ or higher.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.402-413
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• 2022

Objectives: In this study, the scale of exceeding the extreme heat exposure standard at the construction site was estimated using the nationally approved statistical data and wet bulb globe temperature modeling method. By comparing and analyzing the modeling results with the existing work environment monitoring results, the risk of heat exposure at outdoor construction sites was considered. Methods: Using the coordinates of second level administrative districts and meteorological observatories as the key, the automated synoptic observing system data and building permit data for 2021 were matched. The wet-bulb temperature was obtained using Stull's formula, and the globe temperature was obtained using the Tg_KMA2006 model. WBGT was calculated using these. Excess rates were obtained compared to exposure limits for heavy work-continuous work and moderate work-25% rest. It was compared with the results of the work environment monitoring in 2020. Results: As a result, 1,827,536 cases were estimated for 11,052 workplaces in one year. This is much higher than the 5,116 cases of 3818 workplaces of the existing work environment monitoring results. It is confirmed that the exposure limit was exceeded in 10.6~24.0% of the entire period and 70.2~84.1% of the peak period of the heat wave. It is very high compared to 0.9% of the existing work environment monitoring result. Conclusions: It is necessary to improve the system of monitoring and statistics related to extreme heat. Additional considerations are needed regarding WBGT estimation methods, meteorological data, and evaluation time. Various follow-up risk assessment studies for other industries and time series need to be continued.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.80-87
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• 2009

This research was conducted to evaluate pyrolysis characteristics of the sludge discharged from paper mill process with sintering temperature. The sludge was composed of 70.72% of moisture, 9.52% of volatile solids, and 19.76% of ash, respectively. The sludge contained high 66.40% of $Fe_2O_3$ and CaO(15.80%), $Al_2O_3$(9.42%), and $SO_3$(3.75%) components, and minor $SiO_2$, $Na_2O$, and $Cr_2O_3$ were also contained in it. The other components except $Fe_2O_3$ and $Cr_2O_3$ were slightly decreased with increase of sintering temperature. Specific surface area of the sludge before sintering was $130m^2/g$ and ones after sintering at $400^{\circ}C$ and $700^{\circ}C$ were $114m^2/g$ and $33m^2/g$ respectively. Specific surface area of sludge was decreased with increase of sintering temperature. From the result of TG-DTA, it was shown that weight of the sludge was decreased by moisture and organic loss until $600^{\circ}C$ and decreased by volatilization of metal components and additional combustion of carbon until $800^{\circ}C$.

• Journal of Korean Neurosurgical Society
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• v.67 no.5
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• pp.510-520
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• 2024

Objective : Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. The treatment of PD aims to alleviate motor symptoms by replacing the reduced endogenous dopamine. Currently, there are no disease-modifying agents for the treatment of PD. Zebrafish (Danio rerio) have emerged as an effective tool for new drug discovery and screening in the age of translational research. The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to cause a similar loss of dopaminergic neurons in the human midbrain, with corresponding Parkinsonian symptoms. L-type calcium channels (LTCCs) have been implicated in the generation of mitochondrial oxidative stress, which underlies the pathogenesis of PD. Therefore, we investigated the neuro-restorative effect of LTCC inhibition in an MPTP-induced zebrafish PD model and suggested a possible drug candidate that might modify the progression of PD. Methods : All experiments were conducted using a line of transgenic zebrafish, Tg(dat:EGFP), in which green fluorescent protein (GFP) is expressed in dopaminergic neurons. The experimental groups were exposed to 500 μmol MPTP from 1 to 3 days post fertilization (dpf). The drug candidates : levodopa 1 mmol, nifedipine 10 μmol, nimodipine 3.5 μmol, diethylstilbestrol 0.3 μmol, luteolin 100 μmol, and calcitriol 0.25 μmol were exposed from 3 to 5 dpf. Locomotor activity was assessed by automated tracking and dopaminergic neurons were visualized in vivo by confocal microscopy. Results : Levodopa, nimodipine, diethylstilbestrol, and calcitriol had significant positive effects on the restoration of motor behavior, which was damaged by MPTP. Nimodipine and calcitriol have significant positive effects on the restoration of dopaminergic neurons, which were reduced by MPTP. Through locomotor analysis and dopaminergic neuron quantification, we identified the neuro-restorative effects of nimodipine and calcitriol in zebrafish MPTP-induced PD model. Conclusion : The present study identified the neuro-restorative effects of nimodipine and calcitriol in an MPTP-induced zebrafish model of PD. They restored dopaminergic neurons which were damaged due to the effects of MPTP and normalized the locomotor activity. LTCCs have potential pathological roles in neurodevelopmental and neurodegenerative disorders. Zebrafish are highly amenable to high-throughput drug screening and might, therefore, be a useful tool to work towards the identification of disease-modifying treatment for PD. Further studies including zebrafish genetic models to elucidate the mechanism of action of the disease-modifying candidate by investigating Ca2+ influx and mitochondrial function in dopaminergic neurons, are needed to reveal the pathogenesis of PD and develop disease-modifying treatments for PD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.65-72
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• 2012

The aim of this study was to evaluate the effects of unripened cheese supplements on lipid metabolism and antioxidant status in hypercholesterolemic SD rats. Rats were induced to have hypercholesterolemia by feeding them high cholesterol diet (0.5% cholesterol and 0.2% sodium cholate) for 4 weeks and then divided into 2 groups. One group was fed a high cholesterol diet with 5% unripened cheese (URC) daily for 6 weeks, and the other one was fed a high cholesterol diet without 5% unripened cheese (URC) daily for 6 weeks. Significantly-increased plasma total cholesterol (TC), triglycerides (TG), and AST activity because of the high-cholesterol diet were reduced 18.8%, 40.5%, and 33%, respectively, by URC supplementation. Also, URC lowered hepatic total lipids, TCs, and TGs, whereas fecal lipid profiles were not changed by URC. The supplementation of URC resulted in an increase of plasma retinol and ${\alpha}$-tocopherol by 40.5% and 39.2% and leukoytic DNA resistance to oxidative stress by 52.3% compared to hypercholesterolemic control. These results suggest that unripened cheese supplements could exert significant health benefits to those with hypercholesterolemia through ameliorating lipid profiles and antioxidant effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.943-949
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• 2012

This study investigated the effects of diets with a supplement of Job's tears (JT) and Cudrania tricuspidata leaf (CTL) powder as a functional food ingredient on obesity and lipid profiles in diet-induced obese rats. Male Sprague-Dawley rats were fed a high-fat diet (D12492, 45 kcal fat) for 5 weeks during the first phase. In the second phase, which lasted 5 weeks, the rats were divided into four experimental groups. The groups were a high-fat diet group as a control (HFD), a high-fat diet with 10% JT powder supplement group (JT-10), a 10% CTL powder supplement group (CTL-10), and a 20% JT and CTL 1:1 mixed-powder supplement group (MIX-20). The adipose tissue (RFP, EFP) weights were significantly decreased in the CTL-10 and MIX-20 groups than in the HFD group (p<0.05). The fecal weight produced by the MIX-20 group was highest among all experimental groups (p<0.05), and it was significantly increased during the second phase compared to the first phase (p<0.05). The serum total cholesterol content was significantly decreased in the CTL-10 and MIX-20 groups, and the LDL-cholesterol content was significantly low in the JT-10 and MIX-20 groups than in the HFD group (p<0.05). The blood glucose levels were significantly decreased in all experimental diet supplement groups than in the HFD group (p<0.05). The findings show that a diet of mixed JT and CTL could improve lipid metabolism.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1095-1101
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• 2003

This study was carried out to investigate the effect of Gastrodiae Rhizoma (G. Rhizoma) on blood pressure-lowering in spontaneously hypertensive rats (SHR) fed high-fat diet supplemented with 10% (w/w) of lard during the experimental period of 8 weeks. Forty of male SHR weighing approximately 100 g were randomly divided into eight groups; A: negative control (lard 10%), B: positive control (lard 10% ＋ basal diet ＋ 5 brix water extract), C: lard 10% ＋ 1% G. Rhizoma powder, D: lard 10%＋5% G. Rhizoma powder, E: lard 10%＋2 brix 50% ethanol extract, F: lard 10%＋10 brix 50% ethanol extract, G: lard 10%＋2 brix water extract, H: lard 10% ＋ 10 brix water extract. A gain in weight did not differ significantly among dietary groups, but a little higher in control groups than in G. Rhizoma dietary groups. Except for spleen, weights of liver, kidney and testis are significantly different among dietary groups. Serum total cholesterol concentration was markedly higher in control groups than in G. Rhizoma groups (p<0.05), however, there was no significant difference in serum triglyceride. Except for negative control (A) and group D, serum HDL concentration was significantly higher in G. Rhizoma groups (p<0.05). On the other hand, serum LDL concentration was significantly higher in two control groups (A, B) and markedly lower in E and G groups of hot water extract of G. Rhizoma (p<0.05). Reference systolic blood pressure (BP) showed average 185.7$\pm$5.8 mmHg for 4 weeks after feeding high-fat diet, and the pressure was measured on every 7 days intervals after feeding of G. Rhizoma diet. Comparing with reference BP before feeding of G. Rhizoma diet, the groups of 50% ethanol (E, F) and water (G) extracts on BP level after 28 days were shown to be reduced at 16.8, 20.2 and 11.7 mmHg, respectively. When the pressure (187 mmHg) of group A was considered as 100%, the reduction rate of BP in group F was 11% (20.5 mmHg). These results indicated that the groups treated with ethanol extracts of G. Rhizoma showed to have lower blood pressure level compacred to the groups treated with whole powder or water extracts of G.Rhizoma in SHR fed with high-fat diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.437-444
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• 2008

Anti-obesity effects of ginseng and herbal plant mixtures were investigated to develop natural materials for anti-obesity. After inducing obesity with high fat diet for 8 weeks in male SD rats, ginseng and herbal plant mixtures DM1 (ginseng, puer tea, opuntia) and DM2 (ginseng, puer tea) were administrated orally to rats for another 8 weeks. During administration, food efficacy ratio and body weight of rat were measured twice weekly. After administration, body weight, body fat contents, and serum lipid level were estimated for anti-obesity effect and hematological analysis blood level of ALP and ASP was checked for safety. Body weight in rats fed high fat diet was significantly increased. Body weight in obese rats induced by high fat diet was significantly decreased by DM1 and DM2 feedings. The amount of body fat (epididymal, perirenal and visceral fat, brown adipose tissue) was significantly reduced by DM1 and DM2 treatments. The amount of TG, the concentration of leptin in blood plasma, and the concentration of insulin in blood plasma were significantly diminished by DM1 and DM2. Lipid accumulation on liver was reduced in DM2. There were no side effects among all groups according to blood analysis, hematological findings, and body weight. The findings of this study suggest that DM1 and DM2 may be effective materials for anti-obesity through reducing plasma triglyceride and body fats, and also decreasing body weight without side effects.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.202-212
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• 1992

This study reports on the genesis and mineralogical characteristics of the clay minerals in the soils derived from the five major parent rocks of granite, granite-gneiss, limestone, shale, and basalt in Korea. The investigation on the mineralogical aspects of primary and secondary minerals of the rocks and coarse fractions in the soils have been already reported. In this report, the identification of clay minerals in the soil clay fractions was done through the analyses of chemical, X-ray diffraction, and thermal methods. The studies showed clearly that much of the clay minerals was evolved by the weathering of primary minerals and some were further developed by the transformation of secondary minerals. Cation exchange capacity(CEC) of the clay fractions increased with higher amotunts of vermiculite, chlorite, and illite, however, decreased with higher hydroxy octahedral sheet within the interlayer spaces of vermiculite even if dominant clay with vermiculite. Feldspars in the granite and granite-gneiss might be completely transformed to kaolin mineral, Illite, chlolrite, and vermiculite formed by the alteration of micas, amphibole, augite, and primary chlorile seem to be subsequently transformed to the mixed layer minerals such as illite/vermiculite, illite/chlorite, and chlorite/vermiculite. These weathering products may be ultimately transformed into kaolin minerals. The smectite minerals in the clay fractions of the soils developed on the limestone are considerably present and they seem to be formed directly by the precipitation from high Mg solution and/or by the transformation of vermiculite from micas and chlorite in the parent materials. Abundant presence of illite in the soil clays developed on the shale is considered to have inherited from the fine particles and more resistant hydrous muscovite. The weathering sequences of the hydrous muscovite were as follows according to the degree of soil development ; hydrous muscovite ${\rightarrow}$ illite/vermiculite mixed layer(Inceptisols, Daegu series) and hydrous muscovite ${\rightarrow}$ illite/vermiculite mixed layer ${\rightarrow}$ vermiculite ${\rightarrow}$ kaolin mineral(Alfisols, Buyeo series). The plagioclase in the basalt might be mostly weathered to kaolin minerais. The augite in the basalt is likely to be transformed through progressive stage of weathering, augite ${\rightarrow}$ chlorite ${\rightarrow}$ chlorote/vermiculite mixed layer ${\rightarrow}$ vermiculite ${\rightarrow}$ kaolin. Another weathering sequence of augite could be expected, augite ${\rightarrow}$ chlorite ${\rightarrow}$ illite by the presence of illite and illite/vermiculite mixed layer in the clay fractions. Vermiculite and gibbsite were quantified from thermogravimetry(TG) and kaolin minerals, from both TG and differerential thermal analysis (DTA). Vermiculite in Jangseong series from the limestone was the dominant clay mineral of 21.7 percent and had a range in the order of 9.2 percent in Buyeo series to 5.4 percent in Daegu series from the shale. The rest soils ranged from 8.8 to 28.3 percent. Kaolin minerals were the dominant clay mineral of 32.7 percent in Asan series from the granite-gneiss and Gueom series of 32.0 percent from the basalt. The soils from the limestone ranged from 9.4 to 14.9 percent. The rest soils ranged from 8.9 to 28.6 percent. Gibbsite were 3.9 and 2.3 percent for Weoljeong and Chahang series from the granite, respectively. In Asan and Cheongsan series from the giranite-gneiss were 1.4 and 4.5 percent, respectively, and 3.6 percent in Jangpa series from the basalt.

• Journal of the Korean Geographical Society
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• v.41 no.5 s.116
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• pp.527-544
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• 2006

This study provides a definition of heat waves, which indicate the conditions of strong sultriness in summer, appropriate to Korea and intends to clarify long term(1973-2006) averaged spatial and temporal patterns of annual frequency of heat waves with respect to their intensity. Based on examination of the Korean mortality rate changes due to increase of apparent temperature under hot and humid summer conditions, three consecutive days with at least $32.5^{\circ}C,\;35.5^{\circ}C,\;38.5^{\circ}C,\;and\;41.5^{\circ}C$ of daily maximum Heat Index are defined as the Hot Spell(HS), the Heat Wave(HW), the Strong Heat Wave(SHW), and the Extreme Heat Wave(EHW), respectively. The annual frequency of all categories of heat waves is relatively low in high-elevated regions or on islands adjacent to seas. In contrast, the maximum annual frequency of heat waves during the study period as well as annual average frequency are highest in interior, low-elevated regions along major rivers in South Korea, particularly during the Changma Break period(between late July and mid-August). There is no obvious increasing or decreasing trend in the annual total frequency of all categories of heat waves for the study period However, the maximum annual frequencies of HS days at each weather station were recorded mainly in the 1970s, while most of maximum frequency records of both the HW and the SHW at individual weather stations were observed in the 1990s. It is also revealed that when heat waves occur in South Korea high humidity as well as high temperature contributes to increasing the heat wave intensity by $4.3-9.5^{\circ}C$. These results provide a useful basis to help develop a heat wave warning system appropriate to Korea.