• Journal of Environmental Science International
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• v.28 no.1
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• pp.107-123
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• 2019

The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

• Journal of Astronomy and Space Sciences
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• v.36 no.3
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• pp.159-168
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• 2019

In solstices during the solar minimum, the hemispheric difference of the equatorial ionization anomaly (EIA) intensity (hereafter hemispheric asymmetry) is understood as being opposite in the morning and afternoon. This phenomenon is explained by the temporal variation of the combined effects of the fountain process and interhemispheric wind. However, the mechanism applied to the observations during the solar minimum has not yet been validated with observations made during other periods of the solar cycle. We investigate the variability of the hemispheric asymmetry with local time (LT), altitude, season, and solar cycle using the electron density taken by the CHAllenging Minisatellite Payload satellite and the global total electron content (TEC) maps acquired during 2001-2008. The electron density profiles provided by the Constellation Observing System for Meteorology, Ionosphere, and Climate satellites during 2007-2008 are also used to investigate the variation of the hemispheric asymmetry with altitude during the solar minimum. During the solar minimum, the location of a stronger EIA moves from the winter hemisphere to the summer hemisphere around 1200-1400 LT. The reversal of the hemispheric asymmetry is more clearly visible in the F-peak density than in TEC or in topside plasma density. During the solar maximum, the EIA in the winter hemisphere is stronger than that in the summer hemisphere in both the morning and afternoon. When the location of a stronger EIA in the afternoon is viewed as a function of the year, the transition from the winter hemisphere to the summer hemisphere occurs near 2004 (yearly average F10.7 index = 106). We discuss the mechanisms that cause the variation of the hemispheric asymmetry with LT and solar cycle.

• The Journal of the Korean dental association
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• v.56 no.12
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• pp.658-666
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• 2018

This study analyzes 21,686 dental clinic business names from 1946 to February 2016, where official records exist. The results of this study will be used as a historical data of Korean dental clinic and contribute to the decision of dental clinic name. According to the results of analysis, the first official dental clinic used in Korea was 'Chu' in 1946, 'Minsaeng' and 'Chusaeng' in 1958, and "Won" in 1959. In the 1960s, dentists' family names were often used as dental clinics. In the 1970s, dental clinic names were often used as dentists' family name, 'Jung-ang' and 'Seongsin'. In the 1980s, dental clinic name was used more than other names such as 'Seoul', 'Yonsei', 'Hyundai' and 'Sang-a' along with the dentist's family name. In the 1990s, a dental clinic name was used to refer to the words 'Yeonsei', 'Seoul', 'Hyundai', 'Sang-a', 'Isalang', 'Uli', 'Jeil', 'Bubu' used a lot. In the 2000s, Dental Clinic's name began to use english words such as $^{\circ}{\AE}Good$ Morning','White','Prime 'and adjectives such as 'Haengboghan', 'Ipyeonhan'. The characteristic of the dental clinic name in 2010 is the increase of the business name 'UD'. From 1946 to February 2016, the most commonly used dental clinic name was 'Seoul', 'Uri', 'Isarang', 'Yonsei', 'Hyundai', 'Good Morning' 'Jung-ang', 'UD', 'I', 'Miso'.

• Journal of Korean Biological Nursing Science
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• v.23 no.3
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• pp.227-236
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• 2021

Purpose: The purpose of this study was to investigate the sleep duration, social jetlag (SJL), and subjective sleep disturbance according to the individual chronotype in rotating shift nurses. Methods: A total of 344 rotating 3-shift nurses (mean age 28.67 years) were recruited at one university affiliated hospital. They completed the following questionnaires, which were used to assess their chronotype and sleep: the morningness-eveningness questionnaire (MEQ), self-reported sleep duration of work days (SDW_shift) and free days (SDF_shift) in each shift (day [D], evening [E], night [N]), and sleep disturbance (Insomnia severity index, ISI). SJL_shift was calculated as the difference in midsleep (MS=sleep onset+1/2 sleep duration) between work days (MSW) and free days (MSF). Results: Subjects were divided into 3 chronotype groups according to the MEQ; morning (MG, 4.4%) intermediate (IG, 57.8%), and evening groups (EG, 37.8%). SDW_D was shortest (4.68 hr) and SDF_E was longest (8.93 hr) in the EG. SJL_D was longest in the EG (3.77 hr), and SJL_N was longest in the MG (7.37 hr). The prevalence of sleep disturbance was 33.3% (MG), 29.6% (IG), and 40.0% (EG), respectively, without any statistical significance. Conclusion: In order to improve the sleep of shift workers, it is recommended that the evening chronotypes should reduce the day shifts and the morning chronotypes should reduce the night shifts. We also propose a study to determine whether these shift assignments can improve the sleep in shift nurses.

• Journal of Astronomy and Space Sciences
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• v.38 no.4
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• pp.203-215
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• 2021

The auroral observation has been started at Jang Bogo Station (JBS), Antarctica by using a visible All-sky camera (v-ASC) in 2018 to routinely monitor the aurora in association with the simultaneous observations of the ionosphere, thermosphere and magnetosphere at the station. In this article, the auroral observations are introduced with the analysis procedure to recognize the aurora from the v-ASC image data and to compute the auroral occurrences and the initial results on their spatial and temporal distributions are presented. The auroral occurrences are mostly confined to the northern horizon in the evening sector and extend to the zenith from the northwest to cover almost the entire sky disk over JBS at around 08 MLT (magnetic local time; 03 LT) and then retract to the northeast in the morning sector. At near the magnetic local noon, the occurrences are horizontally distributed in the northern sky disk, which shows the auroral occurrences in the cusp region. The results of the auroral occurrences indicate that JBS is located most of the time in the polar cap near the poleward boundary of the auroral oval in the nightside and approaches closer to the oval in the morning sector. At around 08 MLT (03 LT), JBS is located within the auroral oval and then moves away from it, finally being located in the cusp region at the magnetic local noon, which indicates that the location of JBS turns out to be ideal to investigate the variabilities of the poleward boundary of the auroral oval from long-term observations of the auroral occurrences. The future plan for the ground auroral observations near JBS is presented.

• The Korea Journal of Herbology
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• v.24 no.1
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• pp.133-139
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• 2009

Objectives : This study was designed to investigate the effects of alcoholic fermentation extract from ovary and rind of pear on human skin. Methods : We investigated the effects of samples on human skin in terms of clinical trial. 32 of healthy volunteers, who lived in mokpo participated in clinical trial. Effects of sample on hygroscopicity and water-holding capacity were investigated. Sebum, moisture, scabrousness and desquamation were also investigated. Facial massages were conducted 8 times in each volunteers. Results : Single treatment group showed elevated levels of hygroscopicity (Normal : 106.4$\pm$2.1%, vs Pear : 114.1$\pm$6.2) and water-holding capacity (Normal : 87.1$\pm$4.4%, vs Pear : 96.2$\pm$1.3) on forearm of 16 volunteers respectively. In addition, massage group using sample showed elevated moisture (Control : 3.8$\pm$5.8%, vs Sample : 15.2$\pm$4.7%) and lowered scabrousness levels (Control : -12.3$\pm$4.4%, vs Sample : -22.0$\pm$5.2%) significantly. However, the levels of sebum did not affected by sample. Conclusions : These result suggest that alcoholic fermentation extract from ovary and rind of pear has moisturizing effect on human skin.

• Animal Bioscience
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• v.36 no.5
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• pp.704-709
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• 2023

Objective: In tropical, subtropical and arid zones, heat stress is the main cause of productivity reduction in cattle. When climate stressors occur, animals become thermal adapted through differential expression of some genes, including heat shock proteins (HSP) family. The aim of this study was to determine levels of expression of HSP60, HSP70, and HSP90 genes in Simmental cattle raised in tropical environments of Mexico. Methods: In this study, expression of HSP60, HSP70, and HSP90 genes was analyzed in 116 Simmental cattle from three farms with tropical climate located in western Mexico. Animals were sampled twice a day, in the morning and noon. Gene expression was evaluated by quantitative polymerase chain reaction using probes marked with fluorescence. The MIXED procedure of SAS with repeated measures was used for all statistical analysis. Results: HSP60 gene expression differences were found for sex (p = 0.0349). HSP70 gene differences were detected for sampling hour (p = 0.0042), farm (p<0.0001), sex (p = 0.0476), and the interaction sampling hour×farm (p = 0.0002). Gene expression differences for HSP90 were observed for farm (p<0.0001) and year (p = 0.0521). HSP70 gene showed to be a better marker of heat stress than HSP60 and HSP90 genes. Conclusion: Expression of HSP70 gene in Simmental herds of the tropical region of western México was different during early morning and noon, but the expression of the HSP60 and HSP90 genes was similar. Identification of resilient animals to heat stress will be useful in the genetic improvement of the Simmental breed.

• Childhood Kidney Diseases
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• v.28 no.2
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• pp.74-79
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• 2024

Purpose: To compare the Doppler sonographic findings of the left renal vein (LRV) of children diagnosed with nutcracker syndrome with and without orthostatic proteinuria. Methods: Fifty and 53 consecutive children with and without orthostatic proteinuria, respectively, underwent renal Doppler ultrasonography examinations. The peak velocity (PV) was measured at the hilar portion of the LRV and between the aorta and superior mesenteric artery. Renal Doppler ultrasonography findings and clinical data including urine protein-to-creatinine ratio (UPCR) were compared according to the presence or absence of orthostatic proteinuria. Results: Between the two groups, no significant differences were observed in terms of age or sex. The PV ratio between the aortomesenteric and hilar portions was 7.79±2.65 and 6.32±3.01 in children with and without orthostatic proteinuria, respectively (P=0.009). No significant differences were observed between the two groups in terms of the UPCR in the first morning urine sample. However, the UPCR in the afternoon urine sample was significantly higher in children with orthostatic proteinuria than in those without orthostatic proteinuria (0.49±0.46 mg/mg vs. 0.11±0.04 mg/mg, P<0.001). Furthermore, the PV ratio between the aortomesenteric and hilar portions revealed a positive correlation with the ratio of UPCR of the afternoon to that of first morning urine samples (R=0.21, P=0.034). Conclusions: This study suggests that there can be a significant correlation of the PV ratio between the aortomesenteric and hilar portion of the LRV with orthostatic proteinuria in pediatric patients with nutcracker syndrome.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.919-924
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• 2005

This study was carried out to estimate the effects of parity, milking time, milking interval and days in milk(DIM) on variation in milk yield between consecutive milkings(am to pm to am), morning and evening milk yield and its components, somatic cell counts(SCS), milking duration, milk flow rate and peak milk flow in Holstein dairy cattle. Records from one hundred and twenty two heads of Holstein cattle at National Livestock Research Institute, Korea were used for this study from July 1 to August 8, 2005. The experimental herd had average 1.6$\pm$0.9 parities, 199.8$\pm$109.1 DIM and 12.26$\pm$4.06kg milk yields at each milking. Milking yield, percent milk fat and SNF, milking duration and average milk flow were significantly varied by parity, milking time and DIM. Percent milk protein and lactose were varied by parity and DIM, however SCS and average milk flow were affected by parity and milking time. Milking interval significantly affected the consecutive, morning and evening milk yield and average milk flow. However, MUN was not affected by parity, milking time, DIM and milking interval. Milk yield was decreased with increasing parity. Milk yield in the morning was higher than that of in the evening. Milk yield between consecutive milking was not affected by parity, however, affected by milking time. Percent milk Fat, SNF and SCS were higher at in evening milk than those of in morning milk. Milk protein, lactose, SNF, SCS, milking duration and peak milk flow rate were influenced by parity. This study suggested that milk yield variation between consecutive milking, milking flow rate, and milking duration could be important traits for enhancing Holstein cattle productivity however, and more study is needed to estimate genetic parameters for such traits.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.129-149
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• 1991

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ＝0.121, p＜0.01, λ＝0.112, p＜0.01, biweekly shift group : λ＝0.116, p＜0.01, λ＝0.084, p＜0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t＝-2.28, p＜0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝5.79, p＜0.01, F＝4.56, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝12.65, p＜0.01, F＝7.77, p＜0.01, F＝9.68, p＜0.01). There was a significant difference between the shift groups and the control group(p＜0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.79, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.68, p＜0.05, F＝5.55, p＜0.01), and both showed a significant difference between the shift groups and the control group(p＜0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.