• 한국토양비료학회지
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• 제45권1호
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• pp.30-36
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• 2012

The active fraction of soil organic matter, which includes organic debris and light organic fraction, plays a major role in nutrient cycling. In addition, particulate organic matter is a valuable index of labile soil organic matter and can reflect differences in various soil behaviors. Since soil organic matter bound to soil mineral particles has its density lower than soil minerals, we partitioned soil organic matter into debris ($<1.5g\;cm^{-3}$), light fraction ($1.5-2.0g\;cm^{-3}$), and heavy fraction ($>2.0g\;cm^{-3}$), based on high density $ZnCl_{2-}$ sucrose solutions. Generally, partitioned organic bands were clearly separated, demonstrating that the $ZnCl_{2-}$ sucrose solutions are useful for such a density gradient centrifugation. The available gradient ranges from 1.2 to $2.0g\;cm^{-3}$. Although there was not a statistically meaningful difference in organic debris and organomineral fractions among the examined soils, there was a general trend that a higher content of organic debris resulted in a higher proportion of light organomineral fraction. In addition, high clay content was associated with increased fraction of light organomineals. Partitioning of soil organic carbon revealed that carbon content is reduced in the heavy fraction than in the light fraction, reflecting that the light fraction contains more fresh and abundant carbon than the passive resistant fraction. It was also found that carbon contents in the overall organic matter, debris, light fraction, and heavy fractions may differ considerably in response to different farming practices.

• 한국물환경학회지
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• 제36권3호
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• pp.194-205
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• 2020

The characteristics and behavior of dissolved organic matter (DOM) were determined by analyzing the molecular weight fractions and fluorescence properties of water samples in the downstream Nakdong River. Biogeochemical water quality parameters and fluorescent dissolved organic matter (FDOM) were analyzed at five sampling points in the downstream area of the Nakdong River January-August 2019. The molecular weight fractions of the DOM were separated by the Liquid Chromatography-Organic Carbon Detection (LC-OCD). The DOM predominantly comprised humic substances, followed by the building blocks, low molecular weight neutrals and biopolymers. The hydrophobic (aromatic) and hydrophilic properties were shown as coexisting, as most of the SUVA_254nm values were under four. The FDOM was characterized as humic-like (FDOM_H) with allochthonous origin and protein-like (FDOM_P) with autochthonous origin; the FDOM_H with autochthonous origin was also identified. The FDOM_H relies on the aromaticity of the allochthonous organic matter and increases during summer. The FDOM_H and FDOM_P, which depend on the biodegradable dissolved organic matter from phytoplankton, were highly fluorescent in winter. The allochthonous organic matter was the dominant factor contributing to the behavior of the DOM, externally introduced to the river by rainfall. The FDOM only minimally contributed to the behavior of the DOM. It can be explained as the seasonal characteristics of the DOM, varied by the source of the organic matter.

• 한국응급구조학회지
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• 제24권1호
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• pp.37-55
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• 2020

Purpose: The purpose of this study was to provide basic data for improving the response capacity of 119 EMS systems by analyzing the effects of particulate matter on cardio-cerebrovascular and respiratory symptoms in the pre-hospital stage. Methods: We examined 46,389 patients who transferred to the hospital with complaints of cardiopulmonary arrest and cardio-cerebrovascular and respiratory symptoms by 119 ambulances in Incheon from 2016 to 2018. Results: The probability of 119 emergency dispatch for patients with cardiopulmonary arrest increased 2.8-4.0% from the day of symptom onset until two days before hospital presentation as particulate matter 10㎛ or less in diameter(PM₁₀) increased by 10㎍/㎥ (OR=1.028; 95% CI=1.014-1.041, p=0.000, lag 0), (OR=1.040; 95% CI=1.024-1.056, p=0.000, lag 1), (OR=1.032; 95% CI=1.016-1.049, p=0.000, lag 2). Meanwhile, emergency dispatch increased 3.6-6.1% for PM_2.5 in creased by 10㎍/㎥ (OR=1.046; 95% CI=1.024-1.068, p=0.000, lag 0), (OR=1.061; 95% CI=1.035-1.088, p=.000, lag 1), and (OR=1.036; 95% CI=1.010-1.063, p=0.006, lag 2). Conclusion: Emergency medical technicians (EMTs) who respond to 119 calls should rapidly and accurately evaluate patients and provide professional emergency care by identifying the characteristics of the vulnerable groups relative to particulate matter size. To prevent the occurrence and exacerbation of symptoms caused by particulate matter, EMTs should be prepared and equipped with a response system for high particulate matter in the EMS system.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.569-570
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• 2018

최근 미세먼지의 인체 영향에 관한 사회적 관심으로 미세먼지 모니터링에 대한 관심이 높아지고 있으나, 측정소 설치의 불균형 및 지형 차이로 인해 거주 환경에 적합한 데이터를 얻을 수 없다. 본 논문에서는 거주 환경의 미세먼지 측정을 위해 장거리 무선통신이 가능한 LoRa LPWA 기반의 미세먼지 측정 시스템을 제안한다. 제안하는 시스템의 경우 장거리 무선통신 기술인 LPWA를 활용하여 인터넷 구축이 어려운 외부 환경의 데이터를 효과적으로 수집 가능하다. 제안한 시스템을 거주 환경에 적용할 경우 거주 환경에 적합한 미세먼지 모니터링 정보를 제공할 수 있을 것으로 기대된다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.210-213
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• 1999

Magnetoresistance and magnetization of Sr$_{l-x}K_xBiO_3$ were both measured as functions of temperature and magnetic field. Resistivity goes to zero at T=10.1K and the overall superconducting transition behavior under applied magnetic fields is similar to that of other BiO based superconductors. Also, below T<5K we have observed the reappearance of finite resistivity with a power law temperature dependence( ${\rho}$ ${\sim}$T$^1$); the reentrant superconducting transition of resistivity. Contrary to the Josephson weak link effect in polycrystalline samples, which gives the depression of the superconducting state with increasing electrical current or magnetic field, the superconducting state for T<5K is resumed by applying a higher current or magnetic field. Magnetic susceptibility( ${\chi}$ ) of Sr$_{l-x}K_xBiO_3$ for T<5K also shows similar trends to that observed in transport measurements: increase of ${\chi}$ (paramagnetic-like behavior) at a low magnetic fields(B=50 Oe) and, the resumption of perfect diamagnetism at high fields.

• 생물정신의학
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• 제22권1호
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• pp.20-27
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• 2015

Objectives It is increasingly thought that the human cerebellum plays an important role in emotion and cognition. Although recent evidence suggests that the cerebellum may also be implicated in fear learning, only a limited number of studies have investigated the cerebellar abnormalities in panic disorder. The aim of this study was to evaluate the cerebellar gray matter deficits and their clinical correlations among patients with panic disorder. Methods Using a voxel-based morphometry approach with a high-resolution spatially unbiased infratentorial template, regional cerebellar gray matter density was compared between 23 patients with panic disorder and 33 healthy individuals. Results The gray matter density in the right posterior-superior (lobule Crus I) and left posterior-inferior (lobules Crus II, VIIb, VIIIa) cerebellum was significantly reduced in the panic disorder group compared to healthy individuals (p < 0.05, false discovery rate corrected, extent threshold = 100 voxels). Additionally, the gray matter reduction in the left posterior-inferior cerebellum (lobule VIIIa) was significantly associated with greater panic symptom severity (r = -0.55, p = 0.007). Conclusions Our findings suggest that the gray matter deficits in the posterior cerebellum may be involved in the pathogenesis of panic disorder. Further studies are needed to provide a comprehensive understanding of the cerebro-cerebellar network in panic disorder.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.145-155
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• 2014

Vascular dementia is characterized by white matter lesions involving the demyelination and activation of astrocytes and microglia. In a previous study, we showed that the supernatant of a laboratory-scale, hot water extract of ground whole wheat (TALE) attenuated white matter injury and astrocytic activation in a rat model of bilateral common carotid artery occlusion (BCCAO). In the present study, we made several modifications to the hot water extraction process to remove starch and enable large-scale production. We used wheat bran (WB), which contains less starch, instead of ground whole wheat. In addition, we removed starch granules with a decanter before hot water extraction. The final product, wheat bran extract (WBE), contained 2.42% arabinose, a surrogate marker of arabinoxylan, which is an active constituent of WBE. Supplementation of the rat model of BCCAO with WBE (400 mg/kg/day) for 33 days attenuated white matter injury, which was assessed by Luxol Fast Blue staining, in the corpus callosum (cc) and optic tract (opt) regions. Attenuation of white matter injury in the opt region was accompanied by improvement of the pupillary light reflex. Immunochemical staining revealed that supplementation with WBE reduced astrocytic activation in the cc and opt regions and reduced microglial activation in the opt region. These findings indicate that supplementation with WBE is effective at attenuating white matter injury accompanied by the inhibition of astrocytic and microglial activation. Therefore, extracts from WB, a cheap by-product of wheat milling, can be developed as a nutraceutical to prevent vascular dementia, a disease for which there is no approved pharmaceutical treatment.

• Investigative Magnetic Resonance Imaging
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• 제18권4호
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• pp.357-361
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• 2014

목적: 이전의 증례 보고에서는 저혈당성 뇌병증 환자의 뇌백질의 변화가 퇴행하기까지 수 일이 소요되었다. 본 저자들은 저혈당성 뇌병증에서 확산강조영상의 빠른 변화를 경험하였다. 이에 문헌 고찰과 함께 보고자 한다. 증례 보고: 58세 남자 환자가 반혼수 상태로 발견되었으나 혈액 검사 상 저혈당 (44 mg/dL)이 나타난 것 외 특이 소견이 없었다. 혈당 수치를 빠르게 교정한 후 곧바로 촬영한 뇌 확산강조영상에서 양쪽 피질하 백질의 병변이 관찰되었다. 5시간 후 재시행한 확산강조영상에서 피질하 백질이 회복된 대신 양쪽 전방측두두정엽 피질의 병변이 새로이 발견되었다. 결론: 저혈당성 뇌병증 환자에서 뇌백질과 피질이 모두 이상소견을 보이는 증례 보고는 이전에도 다수 있었지만 이처럼 뇌백질 변화가 빠른 퇴행을 보이는 증례는 거의 보고된 바 없다. 저자들은 저혈당성 뇌병증에서 자기공명 영상의 변화가 빠르게는 수 시간 내로도 나타날 수 있다는 걸 알리고자 한다.

• Journal of the korean society of oceanography
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• 제31권3호
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• pp.134-143
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• 1996

Sediment cores were collected from one site each in Amursky and Ussuriysky Bays in the Peter the great Bay for $^{210}Pb$, org C, N, biogenic Si, ${\delta}^{13}$C and ${\delta}^{15}$N analysis to elucidate the processes of biogenic particulate matter accumulation and early diagenetic change in the upper sediment column. Biogeochemistry at the core sites of both bays shows differences in sedimentation rate, sediment mixing, and diagenetic processes of particulate biogenic matter. Sedimentary organic matter at the core sites in both bays appeared to be largely derived from marine origin. Sedimentation rates are 173 and 118 mg $cm^{-2}$ $yr^{-1}$(0.13 and 0.11 cm $yr^{-1}$) in Amursky and Ussuriysky Bays, respectively. The surface mixed layer in the core top was present in Amursky Bay but not in Ussuriysky Bay. At the core site in Amursky Bay, incorporation of biogenic particulate matter into the sediment from the overlying waters is 236, 19, 142 mmol $cm^{-2}$ $yr^{-1}$ for organic C, N, and biogenic Si, respectively. Of which about 70${\%}$ of organic C and biogenic Si are degraded within the upper 25 cm sediment and the rest are buried at 25 cm sediment horizon. At the core site in Ussuriysky Bay, incorporation of biogenic particulate matter into the sediment from overlying waters is 164, 18, 76 mmol $cm^{-2}$ $yr^{-1}$ for organic C, N, and biogenic Si, respectively. Of which less than 50${\%}$ of organic C and biogenic Si are degraded within the upper 25 cm sediment and the remainder are buried at 25 cm sediment horizon. This large difference of degradation of biogenic matter in the upper 25 cm sediment column appears to be resulted from the difference in sediment mixing rates between the two cores.

• 한국초지조사료학회지
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• 제20권1호
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• pp.55-60
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• 2000

This experiment was carried out to determine the effect of cutting frequency(3rd and 5th cut) and level of nitrogen fertilization(l50 + liquid manure, 300 and 450kgha) on growth characteristics, dry matter yield and nutritive vaule of reed canarygrass(Pha1aris arundinacea L.), at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon. Plant height of 3rd cutting(79.2cm) was significantly higher than that of 5th cutting(58.0cm). And dry mattter yield of cutting frequency was observed in 3rd cutting(16,902kgPna) and 5th cutting(l7,833kg/ha) As the nitrogen fertilization was increased, DM yield was significantly increased(p<0.05). When the nitrogen fertilization was applied at the level 150 + liquid manure, 300 and 450kg, dry matter yields were 16,5 12, 17,123 and 18,368kg/ha, respectively. The contents of neutral detergent fiber(NDF), acid detergent fiber(ADF) and in vitro dry matter digestibility(1VDMD) were similar among cutting frequency. However, slightly higher NDF, ADF and IVDMD contents were found in 5th cutting, but there was not affected by nitrigen fertilization. Based on the results of this experiment, it were indicated that to 5th cutting and 450kg nitrogen fertilization could be obtained from the increase of dry matter yield and nutritive value (Key words : Cutting frequency, Nitrogen fertilization, Dry matter yield, Nutritive Value, Reed canarygrass)