• 한국환경과학회지
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• 제32권1호
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• pp.37-46
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• 2023

This study investigated the effect of May 31, 2022 Miryang wildfire on fine particle concentrations in Busan and Gimhae, which are neighboring urban areas. In addition, fine particle characteristics and air pollution concentrations were investigated in Miryang, where haze occurred. The Miryang city wildfire that occurred on May 31, 2022, at 0925 LST, was driven by strong north winds and increased fine particle concentrations in Dongsangdong and Jangyoodong, Gimhae City, which are approximately 35 km to the southeast and south, respectively, of the wildfire occurrence site. Furthermore, the fine particle concentration in Myeongjidong, which is approximately 50 km south-southeast of the wildfire site, exhibited a temporary increase at 1400 LST owing to the effects of wildfire smoke. On the morning of June 1, the day after the fire, the Miryang area had very bad visibility because of the smoke from the fire. Therefore the PM₁₀ and PM_2.5 concentrations in Naeildong, 3 km south of the wildfire site, were 276 ㎍/㎥ and 222 ㎍/㎥, respectively, at 1200 LST. In addition, the gases O₃, CO, and SO₂ showed high concentrations at the time of haze generation. This study provides insights into policy making in response to the rapid increase in fine dust when wildfire occurs near cities.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.493-500
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• 2022

The objective of this study was to derive derived concentration guideline levels (DCGLs) reflecting the site-specific characteristics of KRR-1&2. A total of 7 nuclides (H-3, C-14, Co-60, Sr-90, Cs-137, Eu-152, and Eu-154) were selected for DCGLs derivation. Radiation dose at the sites was evaluated with RESRAD-ONSITE program. The dose contribution due to direct external exposure was the highest during the entire evaluation period. Ingestion had the second effect. The DCGLs of Co-60 was derived to be 0.051 Bq/g, and DCGLs of Cs-137 was 0.193 Bq/g. The DCGLs of H-3 showed the highest value of 129 Bq/g. The ratio of DCGLs derived by applying site-specific values and default values ranged from 0.27 to 19.6. For six nuclides excluding H-3, KRR-1&2 sites and the overseas NPP sites showed similar DCGLs. H-3 showed large differences in DCGLs from this study and overseas NPPs. The large difference resulted from input parameter values applied to the sites. In conclusion, it is critical to apply site-specific parameter values reflecting the site characteristics to derive DCGLs for decommissioned site clearance. The result of this study can be used as a reference for nuclide selection and DCGLs derivation reflecting the site characteristics when decommissioning nuclear facilities, including nuclear power plants in Korea.

• Journal of Dental Anesthesia and Pain Medicine
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• 제20권4호
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• pp.195-202
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• 2020

Background: Nasotracheal intubation is the most commonly used method to secure the field of view when performing surgery on the oral cavity or neck. Like orotracheal intubation, nasotracheal intubation uses a laryngoscope. Hemodynamic change occurs due to the stimulation of the sympathetic nervous system. Recently, video laryngoscope with a camera attached to the end of the direct laryngoscope blade has been used to minimize this change. In this study, we investigated the optimal effect-site concentration (Ce) of remifentanil for minimizing hemodynamic responses during nasotracheal intubation with a video laryngoscope. Methods: Twenty-one patients, aged between 19 and 60 years old, scheduled for elective surgery were included in this study. Anesthesia was induced by slowly injecting propofol. At the same time, remifentanil infusion was initiated at 3.0 ng/ml via target-controlled infusion (TCI). When remifentanil attained the preset Ce, nasotracheal intubation was performed using a video laryngoscope. The patient's blood pressure and heart rate were checked pre-induction, right before and after intubation, and 1 min after intubation. Hemodynamic stability was defined as an increase in systolic blood pressure and heart rate by 20% before and after nasotracheal intubation. The response of each patient determined the Ce of remifentanil for the next patient at an interval of 0.3 ng/ml. Results: The Ce of remifentanil administered ranged from 2.4 to 3.6 ng/ml for the patients evaluated. The estimated optimal effective effect-site concentrations of remifentanil were 3.22 and 4.25 ng/ml, that were associated with a 50% and 95% probability of maintaining hemodynamic stability, respectively. Conclusion: Nasotracheal intubation using a video laryngoscope can be successfully performed in a hemodynamically stable state by using the optimal remifentanil effect-site concentration (Ce₅₀, 3.22 ng/ml; Ce₉₅, 4.25 ng/ml).

• International Journal of Contents
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• 제11권2호
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• pp.69-73
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• 2015

This study was performed to determine the optimal doses of alfentanil or remifentanil (effect-site concentrations) required to prevent pain and other suffering after abdominal general surgery in ICU patients. A total of 52 general abdominal surgical patients (ASA IIIII) requiring artificial ventilatory care in the ICU were provided with either alfentanil (24 patients) or remifentanil (28 patients) through target controlled infusion (TCI). Alfentanil and remifentanil concentrations were titrated up and down until the pain score became less than 3 (VAS; Visual Analogue Score < 3). The effect-site concentrations (ng/ml) of alfentanil or remifentanil required to adequately control postoperative pain in the ICU were 64 +/- 12 and 1.9 +/- 0.5 for intubation with artificial ventilation, 57 +/- 9 and 1.7 +/- 0.7 for intubation with spontaneous ventilation, and 41 +/- 10 and 1.2 +/- 0.5 after extubation, respectively. Pain scores and the corresponding opioid concentrations were independent from respiratory condition. The three effect-site concentrations of alfentanil and remifentanil obtained from this clinical trial using the TCI technique can be a guideline in the administration of the same opioids to relieve the discomfort of ICU patients who have undergone abdominal general surgery.

• 한국대기환경학회지
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• 제25권6호
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• pp.571-578
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• 2009

$PM_{2.5}$ black carbon (BC) concentrations were measured to investigate the filter spot loading effect in raw BC data at 5-minute time-based resolution using a single-wavelength aethalometer at a Gwangju site. Also the elemental carbon (EC) concentrations from 24-hr integrated filter-based measurements of $PM_{2.5}$ particles were determined to compare with the loading compensated BC values. Close examination of the time-series BC data showed clearly the "gaps" when the filter tape advances, suggesting the correction of raw BC data. Therefore, we calculated the average BC concentration in each range of attenuation (ATN) to decide if there was (or was not) an effect on the aethalometer data according to the loading of the filter spot. A consistent decrease of average BC concentration was found with increasing ATN values for every month, suggesting there was a consistent "spot loading effect" in the raw BC data. The loading compensated BC concentration according to a simple compensation model with loading effect was 1.01~1.15 times greater than the raw BC data. The 24-hr average concentration of EC observed during summer sampling period was about 3% higher than the original 24-hr average BC value and 2% lower than the loading compensated BC concentration.

• The Korean Journal of Physiology and Pharmacology
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• 제2권3호
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• pp.385-393
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• 1998

Human neutrophil elastase (HNElastase, EC 3.4.21.37), a causative factor of inflammatory diseases, was purified by Ultrogel AcA54 gel filtration and CM-Sephadex ion exchange chromatography. HNElastase was inhibited by phenylbutazone in a concentration dependent manner up to 0.4 mM, but as the concentration increased, the inhibitory effect gradually diminished. Binding of phenylbutazone to the human neutrophil elastase caused strong Raman shifts at 200, 440, and 1194 $cm^{-1}$. The peak at 1194 $cm^{-1}$ might be evidence of the presence $of\;-N=N-{\Phi}$ radical. The core area of the elastase, according to the visual molecular model of human neutrophil elastase, was structurally stable. A deeply situated active center was at the core area surrounded by hydrophobic amino acids. Directly neighboring the active site was one positively charged atom and two atoms carrying a negative charge, which enabled the enzyme and the drug to form a strong interaction. Phenylbutazone may form a binding, similar to a key & lock system to the atoms carrying opposite charges near the active site of the enzyme molecule. Furthermore, the hydrophobicity of the surrounding amino acid near the active site seemed to enhance the binding strength of phenylbutazone. Binding of phenylbutazone near the active site may cause masking of the active site, preventing the substrate from approaching the active site and inhibiting elastase activity.

• 한국입자에어로졸학회지
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• 제8권3호
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• pp.111-120
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• 2012

In Daegu, a road cleaning system was constructed in the central part of the city and has been operated from April, 2011. We evaluated the effect of the system on the concentration of $PM_{10}$ at a roadside monitoring site. The ambient $PM_{10}$ concentration data were logged every 1 min for a period of 20 weeks from May to October, 2011, by means of light scattering method, and then every 5 min data were used in the statistical analysis. The measured data were verified by comparing them with beta-ray data obtained at the same site. Correlation coefficient between the two groups was highly significant (r=0.79), though the absolute levels of light scattering data appeared to be approximately 2.8 times higher than the beta-ray data. Diurnal, daily, weekly, and monthly variations of $PM_{10}$ data did not show any evidence of decreasing effect owing to the clean road system. A comparison of roadside $PM_{10}$ data with non-roadside data also revealed very similar pattern, implying the variation of the $PM_{10}$ concentrations is mainly affected by the traffic conditions near the monitoring site. However, if the operating conditions of the clean road system can be improved, i.e. increasing the frequency and duration of water cleaning, the road cleaning effect may improve the air quality indirectly by means of removing the resuspended particles from the road.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2004년도 추계 학술대회 및 정기총회
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• pp.7-11
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• 2004

We previously reported that ginseng inhibited NMDA receptors in cultured hippocampal neurons. Here, we further examined the detailed mechanism of ginseng-mediated inhibition using its main active ingredient, ginsenoside Rg$_3$. Co-application of ginsenoside Rg$_3$ with increasing concentrations of NMDA did not change the EC$_{50}$ of NMDA to the receptor, suggesting ginsenoside Rg$_3$ inhibits NMDA receptors without competing with the NMDA-binding site. Ginsenoside Rg$_3$-mediated inhibition also occurred in a distinctive manner from the well-characterized NMDA receptor open channel blocker, MK-801, However, ginsenoside Rg$_3$ produced its effect in a glycine concentration-dependent manner and shifted the glycine concentration-response curve to the right without changing the maximal response, suggesting the role of ginsenoside Rg$_3$ as a competitive NMDA receptor antagonist. We also demonstrated that ginsenoside Rg$_3$ significantly protected neurons against NMDA insults. Therefore, these results suggest that ginsenoside Rg$_3$ protects NMDA-induced neuronal death via a competitive interaction with the glycine-binding site of NMDA receptors in cultured hippocampal neurons.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1997-2001
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• 2010

Generally, railroad soil around turnout was caused by leakage of lubricant oils during its maintenance. So, TPH concentration in soil was much higher than standard in Soil Envirnment Law. In additiont, railroad site was still difficult to assess due to railcar operation. This research was conducted to investigate the effect on electrolyte concentration during the Electrokinetic-Fenton process for contaminated soil around railroad turnout. As a result, experimental result shows that TPH removal in soil and amount of EOF were changed depending on electrolyte concentration. In future, the removal efficiency can be enhanced to optimize concentration in EK-Fenton Process.

• 한국환경과학회지
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• 제12권4호
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• pp.419-426
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• 2003

This study was performed to research ozone concentration related to airmass thunderstorm using 12 years meteorological data(1990~2001) at Busan. The occurrence frequency of thunderstorm during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence at summertime(59%). In case August 4, 1996, increase of ozone concentration was simultaneous with the decrease of temperature and increase of relative humidity, In case July 23, 1997, ozone concentration of western site at Busan increased, while its of eastern site decreased as airmass thunderstorm occurred(about 1500LST). It is supposed that these ozone increases are the effect of ozone rich air that is brought down by cumulus downdrafts from height levels where the ozone mixing ratio is larger. Thunderstorms can cause downward transport of ozone from the reservoir layer in the upper troposphere into planeta교 boundary layer(PBL). This complex interaction of source and sink processes can result in large variability fer vertical and horizontal ozone distributions. Thus a variety of meteorological precesses can act to enhance vertical mixing between the earth's surface and the atmospheric in the manner described fer thunderstorm.