• Health Policy and Management
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• v.3 no.2
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• pp.81-99
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• 1993

The purpose of this research is to assess the geographical distribution of physicians and dentists and the degree of maldistribution of the physician. Data were obtained form the Korean Medical Association's report on physicians registry and census for 1990. To assess the degree of disparity in the rural-urban distribution of physician manpower and to identify changes in the distribution pattern, the Gini index of concentration was used. Major findings are as follows; 1. Urban-rural disparity in the distribution of physician manpower exists in all categories of manpower, i.e. physician, dentist, oriental medical doctor, general practitioner, medical specialist, practitioner, public health physician and public health dentist. Urban area which had 74.4% of nation's population, accounted for over 90% of all physician manpower. 2. In terms of the ration of physician manpower per 10, 000 population, in urban area, they were 8.2 physicians, 2.7 general practitioners, 5.5 specialists, 3.0 practitioners, 1.8 dentists and 1.3 oriental medical doctors. In rural area, the ratios were 1.4 physicians, 0.6 general practitioners, 0.9 specialists, 1.0 practitioners, 0.4 dentists and 0.4 oriental medical doctors. 3. Gini indicies computed to measure inequality of physician manpower distribution were 0. 3675 for physicians, 0.3372 for general practitioners, 0.3338 for specialists, 0.2263 for practitioners, 0.3132 for dentists and 0.3293 for oriental medical doctors. 4. Inspite of increase in the number of physician manpower, urban concentration of physician manpower intensified from 1980 to 1990. However, the Gini index for all physician manpower fell by 18.3~36.7% from 1980 to 1990, indicating more even distribution. 5. In rural area, the public health physicians and dentists had increased the ratios of physicians, general practitioners, practitioners and dentists per 10, 000 population remarkebly, and had decreased the Gini indicies of physicians, general practitioners, practitioners and dentists. Thus, public health physicians and dentists contributed to improve the distribution of physician manpower in rural area. Based on the results of this study, long-term and rational manpower policies should be developed to solve the problem of geographical maldistribution of physician manpower as well as short-term policy for inducing physicians to the rural areas.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.3
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• pp.159-169
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• 2023

Purpose : Though other Citrus spp. have reported their anti-inflammatory and antioxidative activities in previous studies, the biological activity of Kiyomi (Citrus unshiu × C. sinensis) has not been reported yet. Therefore, this study attempted to analyze the anti-inflammatory mechanisms of Kiyomi leaf ethanol extract (KLEE) in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Methods : The cytotoxic effect of KLEE in RAW 264.7 cells was determined by WST-1 assay. Bacterial endotoxin, the concentration of nitric oxide (NO) was analyzed by the Griess reaction. In addition, Western blot analysis was applied to measure the protein expression level of inducible NO synthase (iNOS). The phosphorylated status of the critical inflammatory transcription factor, nuclear factor (NF)-𝜅B, and its upstream signaling molecules, phosphoinositide 3-kinase (PI3K)/Akt as well as mitogen-activated protein kinases (MAPKs), were also measured by Western blot analysis. Results : KLEE was not cytotoxic up to a concentration of 200 ㎍/㎖, and protein expression levels of iNOS and cyclooxygenase (COX)-2, enzymes that counteract NO and prostaglandin (PG) E2 production, were inhibited by KLEE treatment. The phosphorylated status of PI3K/Akt as well as MAPKs including extracellular regulated kinase (ERK), c-jun NH2kinase (JNK), and p38, were significantly attenuated by KLEE treatment in LPS stimulated RAW 264.7 cells. Moreover, one of phase II enzymes, heme oxygenase (HO)-1 which has known for its anti-inflammatory capacity, was strongly induced by KLEE treatment. Conclusion : Consequently, KLEE treatment significantly attenuated the production of NO as well as the expression levels of iNOS and COX-2 in LPS-stimulated RAW 264.7 cells. The inflammatory transcription factor, NF-𝜅B, as well as its upstream signaling molecules, PI3K/Akt and MAPKs, were also diminished by KLEE treatment with statistical significance in LPS-stimulated RAW 264.7 cells. These results suggest that KLEE might be a promising candidate for the attenuation of inflammatory disorders.

• The Korea Journal of Herbology
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• v.38 no.5
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• pp.61-67
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• 2023

Objective : Mori Fructus has been used to relieve thirst, and treat dizziness, tinnitus, and insomnia caused by poor constitution. This study was performed to investigate the protective effect of the ethanol extract of Mori Fructus (MF) in ultraviolet B (UVB)-induced apoptotic cell death in human keratinocyte cells. Methods : MF was prepared by extracting 100 g of Mori Fructus in 1 L of 100% ethanol for 48 h. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to measure cell viability. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and the expression of apoptosis-related proteins was observed by Western blot. Tyrosinase activity was measured with a colorimetric commercial kit. Results : MF promoted cell vitality and inhibited apoptosis of UVB-induced HaCaT cells. MF pretreatment reduced TUNEL-positive cells and increased the expression of caspase-3 and -9. MF also displayed antioxidant effect with high radical scavenging ability. At 2 ㎎/㎖ concentration, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition rates were 55.3 ± 4.6% and 48.5 ± 1.3%, respectively. Furthermore, MF showed a concentration-dependent inhibitory effect on tyrosinase. Conclusion : These results suggest that MF functions as a protective regulator in UVB-induced HaCaT cells by regulating apoptosis and partially exerting antioxidant effects. In addition, the tyrosinase inhibitory effect of MF shows the potential for MF to be used for skin pigmentation.

• Journal of Surface Science and Engineering
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• v.34 no.5
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• pp.435-444
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• 2001

WC-( $Ti_{1-x}$ A $l_{x}$) N coatings of constant changing Al concentration were deposited on S45C substrates by high-ionization sputtered PVD method. The Al concentration could be controlled by using evaporation source for Al and fixing the evaporation rate of the metals (i.e, WC- $Ti_{0.86}$A $l_{0.14}$N, WC- $Ti_{0.72}$A $l_{0.28}$N, and WC- $Ti_{0.58}$A $l_{0.42}$N). The corrosion behavior of WC-( $Ti_{1-x}$ A $l_{x}$)N coatings in a deaerated 3.5% NaCl solution was investigated by electrochemical corrosion tests and surface analyses. The measured galvanic corrosion currents between coating and substrate indicated that WC- $Ti_{0.72}$A $l_{0.28}$N coating showed the best resistance of the coating tested. The results of potentiodynamic polarization tests showed that the WC- $Ti_{0.72}$A $l_{0.28}$N coating deposited with 32W/c $m^2$ of Al target revealed higher corrosion resistance. This indicated that the WC- $Ti_{0.72}$A $l_{0.28}$N coating is effective in improving corrosion resistance. In EIS, the WC- $Ti_{0.72}$A $l_{0.28}$N coating showed one time constant loop and increased a polarization resistance of coating ( $R_{coat}$) relative to other samples. Compositional variations of WC-( $Ti_{1-x}$ A $l_{x}$)N coatings were analyzed by EDS and XRD analysis was performed to evaluate the crystal structure and compounds formation behavior. Surface morphologies of the films were observed using SEM and AFM. Scratch test was performed to measure film adhesion strength.strength. adhesion strength.strength.

• Journal of Korean Port Research
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• v.11 no.2
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• pp.305-320
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• 1997

The objective of this paper is to analysis & forecast on the change in spatial structures of southeast region by development of the Seoul-Pusan high-speed Rail. To measure the spatial structures, it was used the method of mean center and standard distance among of centrographic measures as analytical tools. The changes of spatial structures patten over time and space in the southeast region were surveyed using population and employment data of 57 zones. And also, to forecast the spatial structures of the southeast region after opening of the Seoul-Pusan high-speed rail, it was supposed three(3) scenarios which designed using influential area with centering around of the proposed high-speed rail stations. Therefore, the results of this research indicate as follows; 1) The spatial structures of population is showed a trend of continual concentration toward Ulsan city area, and also the spatial structures of employment is showed a trend of continual dispersion over time. 2) The forecast of three93) scenarios supposed after opening of the Seoul-Pusan high-speed rail in 2006 show a change of the spatial structures with both population concentration and employment dispersion. In the meantime, the rapid increase of population and wide dispersion of employment is reform with centering around HSR stations which builted in the southeast region after opening of high-speed rail. 3) It shall furnish valuable data to establish the development strategy of urban and local region, and also forecast the change of spatial structures about population and employment in influential area which passed on high-speed rail line & stations by method of mean center and standard distance among of centrographic measures as analytical tools.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.1
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• pp.11-18
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• 2022

Background: The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats. Methods: Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure-volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function. Results: After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5-15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Conclusion: Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.

• Analytical Science and Technology
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• v.19 no.6
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• pp.553-558
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• 2006

In this study, an attempt was made to measure uncertainties involved in the VOC analysis for the VOC working standards prepared by a dilution technique using Tedlar bags. For this purpose, VOC standard gases of benzene, toluene, xylene, and styrene were prepared at four different concentrations (4, 8, 20, and 40 ppb). These standard samples were then loaded on to the GC system equipped with air server/thermal desorption (AS/TD) system. Each of these four standard concentrations was analyzed individually to derive their respective calibration results. These calibration data sets were then compared across four different compounds. According to this comparison, differences in calibration patterns were moderately insignificant within the selected concentration range of 4~40 ppb. It was also observed that the loss of styrene standard was fairly high compared to other VOCs investigated simultaneously. The results of our study suggest that the analytical uncertainty associated with the preparation of VOC starndard gas using a dilution technique can be assessed in a fairly reasonable manner for samples with a narrow concentration range.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.313-313
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• 2022

The Smilacis chinae Radix refers to the root of Smilax chinae L distributed in mountain and filed of Korea, and it is a vine shrub in the Lilaceae family, called Berchemia berchemiaefolia, and is referred to as Smilacis chinae Radix in it's a natural medicine name. Antibacterial, inflammatory, and antioxidant activity were studied in Smilacis chinae Radix. In this study, biological activities such as antioxidant (DPPH, ABTs, TPC), cytotoxicity, wrinkle improvement, and whitening improvement to increase the utilization value of Smilacis chinae Radix and identify the botanical value. Therefore, we tried to explore the applicability of Smilacis chinae Radix as a functional cosmetic material. Smilacis chinae Radix (SCR) was dried and extracted with ethanol. In order to measure the biological activity of the SCR, antioxidant activity, inhibition activities of collagenase, tyrosinase and cell viability were measured. The DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity in the extract with a concentration of 400㎍/mL is 91.22% ± 0.41%%. ABTs (2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity in the extract with a concentration of 400㎍/mL is 99.60% ± 0.03%. Total polyphenol contents (TPC) are 0.203 ± 0.05 mg GAE/mg Ext when SCR was lmg/mL. And the Cell viability for HaCaT derived human keratinocyte and Raw264.7, a mouse-derived macrophage was determined using the MTT assay. When cell was treated with 100㎍/mL of SCR, HaCaT cell showed cell viability of 78.09 ± 0.1% and Raw264.7 cell showed cell viability of 91.88 ± 0.42%. From the above results, we have shown the possibility that the CSR have antioxidant ability, inhibition activity of collagenase and tyrosinase and cell safety ability which can be useful in a functional cosmetic material.

• Journal of Sensor Science and Technology
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• v.32 no.5
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• pp.290-294
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• 2023

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.132-140
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• 2024

In the event of a severe accident in Sodium Cooled Fast Reactors (SFR), the sodium combustion aerosols along with fission product aerosols would migrate to the environment through leak paths of the Reactor Containment Building (RCB) concrete wall under positive pressure. Understanding the characteristics of sodium aerosol transport through concrete leak paths is important as it governs the environmental source term. In this context, experiments are conducted to study the influence of various parameters like pressure, initial mass concentration, leak path diameter, humidity etc., on the transport and deposition of sodium aerosols in straight leak paths of concrete. The leak paths in concrete specimens are prepared by casting and the diameter of the leak path is measured using thermography technique. Aerosol transport experiments are conducted to measure the transported and plugged aerosol mass in the leak paths and corresponding plugging times. The values of differential pressure, aerosol concentration and relative humidity taken for the study are in the ranges 10-15 kPa, 0.65-3.04 g/m³ and 30-90% respectively. These observations are numerically simulated using 1-Dimensional transport equation. The simulated values are compared with the experimental results and reasonable agreement among them is observed. From the safety assessment view of reactor, the approach presented here is conservative as it is with straight leak paths.