• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권3호
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• pp.127-137
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• 2000

This study presents an analysis of the characteristics of vertical ozone distribution near the surface using ozonesonde data(l995 to 1998), plus surface ozone and meteorological data from the Pohang region. These features were examined in detail using three case studies. The first related to episodes of high surface ozone concentrations during the Spring season when the frontogenesis between the high and low pressure associated with the upper-level jet stream was found to be located near the surface. The second was a 5-day winter period(l3 -17 December, 1997) in the Pohang province when the hourly concentrations exceeded 90 ppb on several occasions owing to low-level jets(LLJs) induced by a nocturnal stable layer. Accordingly, this explains why the high surface ozone concentrations occurred at night as the ozone was transported across the zone by a strong wind speed( over 12.5 ms .1). The third case study was ozone enhancement due to photochemical reactions. In this case, the maximum concentration of ozone exceeded 60 ppb in the summer(23 -28 August, 1997). When an ozone peak appeared within the boundary layer, the occurrence frequency of a low-level jet due to the nocturnal stable layer was about 77%, similarly the occurrence frequency of a near-surface ozone peak relative to the appearance of an LLJ was about 76%. Accordingly, there is clearly a close correlation between the occurrence of LLJs and near-surface ozone peaks.

• Clinical and Experimental Pediatrics
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• 제53권12호
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• pp.1006-1011
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• 2010

Purpose: This study aimed to identify 'objective' differential factors for normal frequent loose stool (NFLS) and diarrheal illness with dehydration and nutritional deficiency (DIDN) among infants with chronic frequent loose stool (CFLS). Methods: Data were analyzed from infants under 2 years of age with CFLS who had been transferred from general pediatricians. These 46 patients were divided into 2 groups (NFLS versus DIDN). Nocturnal stool was defined as evacuation between 10 pm and 6 am. Maximal stool amount/day (measured using the mother's hand) was specified as the highest score during the period of CFLS obtained by adding up each evacuation's score (range, 0-2 points). Results: There were 36 cases of NFLS and 10 of DIDN. A failure to gain weight ($P$=0.0001), fever ($P$=0.0079), colic/abdominal pain ($P$=0.0014), gross blood in stool (except allergic proctocolitis) ($P$=0.0113), nocturnal stool ($P$=0.0001), and the score of stool amount ($P$=0.0001) were found to significantly differentiate the groups. A failure to gain weight was observed in 39% of even NFLS. The frequency, mucus content, and microbiological findings of stools, as well as diaper dermatitis were not found to significantly differentiate the groups. Conclusion: NFLS was more common than DIDN in infants with CFLS. The most 'objective' differential factors were nocturnal stool and the score of stool amount (${\geq}7$ points/day).

• Tuberculosis and Respiratory Diseases
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• 제47권2호
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• pp.231-238
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• 1999

Background: Nocturnal hypoxemia occurs in patients with chronic obstructive pulmonary disease(COPD) and the detection and treatment of nocturnal hypoxemia should be part of the management of COPD patients. We performed this study to evaluate the factors influencing to sleep related arterial oxygen desaturation($SaO_2$) in patients with COPD. Methods: Resting and exercise cardiopulmonary function test, polysomnography, and $SaO_2$ during resting, exercise and sleep were measured in 12 patients with COPD. Results: The $SaO_2$ fell twice as much during sleep as during maximal exercise($13.1{\pm}9.3%$ fall in nocturnal $SaO_2$ vs. $6.4{\pm}3.3%$, p<0.05). Fall in nocturnal $SaO_2$ was well correlated with mean exercise $SaO_2$(r=-0.78, p<0.05), minimum exercise $SaO_2$(r=-0.90, p<0.01), and resting $SaO_2$(Cr=-0.82, p<0.05). Lowest sleep $SaO_2$ was well correlated with mean exercise $SaO_2$(r=0.80, p<0.05), lowest exercise $SaO_2$(r=0.90, p<0.01), and resting $SaO_2$(r=0.84, p<0.05). Conclusion: Resting and exercise $SaO_2$ was well correlated with nocturnal $SaO_2$, but exercise study add no additional information to predicting the nocturnal oxygen desaturation in patients with COPD.

• Childhood Kidney Diseases
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• 제15권2호
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• pp.146-153
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• 2011

Purpose : Hypercalciuria has been suggested to be involved in the pathogenesis of nocturnal enuresis associated with polyuria. We have measured the amount of calcium excretion in the urine from children with monosymptomatic nocturnal enuresis and studied the association with enuresis. Methods : Thirty-six children (20 males and 16 females, age 5 to 15.6 years) presenting with monosymptomatic nocturnal enuresis were recruited for this study. Results : Among 36 patients, 6 patients had hypercalciuria, providing a 16.7% frequency. The mean Ca/Cr ratio of hypercalciuria group showed $0.23{\pm}0.10$ on daytime, and $0.33{\pm}0.10$ on nighttime showing higher values in nighttime, but it was not statistically significant. Average 24 hour calcium excretion was 8.95 mg/kg. Night/day time urine volume ratio in hypercalciuria group was $0.87{\pm}0.20$, and that in normocalciuria group was $0.81{\pm}0.33$, also showing no difference. Daytime Ca/Cr ratio and nighttime Ca/Cr ratio from all enuresis patients showed a significant correlation (P=0.0001). However, Ca/Cr ratio between daytime and nighttime urine volume had no significant correlation, respectively (daytime P=0.08; nighttime P=0.07). Also, daytime and nighttime Na concentration, urea concentration, and osmolality also had no significant correlation with urine Ca/Cr ratio, respectively. Conclusion: Hypercalciuria shown in some of enuresis patients is not directly caused by primary monosymptomatic nocturnal enuresis.

• Journal of Environmental Science International
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• 제13권11호
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• pp.965-985
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• 2004

The investigation of driving mechanism for the formation of tropical night in the coastal region, defined as persistent high air temperature over than 25$^{\circ}C$ at night was carried out from August 14 through 15, 1995. Convective boundary layer (CBL) of a 1 km depth with big turbulent vertical diffusion coefficients is developed over the ground surface of the inland basin in the west of the mountain and near the top of the mountain, while a depth of thermal internal boundary layer (TIBL) like CBL shrunken by relatively cool sea breeze starting at 100 km off the eastern sea is less than 150 m from the coast along the eastern slope of the mountain. The TIBL extends up to the height of 1500 m parallel to upslope wind combined with valley wind and easterly sea breeze from the sea. As sensible heat flux convergences between the surface and lower atmosphere both at the top of mountain and the inland coast are much greater than on the coastal sea, sensible heat flux should be accumulated inside both the TIBL and the CBL near the mountain top and then, accumulated sensible heat flux under the influence of sea breeze circulation combined with easterly sea breeze from sea to inland and uplifted valley wind from inland to the mountain top returning down toward the eastern coastal sea surface should be transported into the coast, resulting in high air temperatures near the coastal inland. Under nighttime cooling of ground surface after sunset, mountain wind causes the daytime existed westerly wind to be an intensified westerly downslope wind and land breeze further induces it to be strong offshore wind. No sensible heat flux divergence or very small flux divergence occurs in the coast, but the flux divergences are much greater on the top of the mountain and along its eastern slope than on the coastal inland and sea surfaces. Thus, less cooling down of the coastal surface than the mountain surface and sensible heat transfer from warm pool over the coast into the coastal surface produce nocturnal high air temperature on the coastal inland surfaces, which is not much changed from daytime ones, resulting in the persistence of tropical night (nocturnal thermal high) until the early in the morning.

• Sleep Medicine and Psychophysiology
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• 제2권1호
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• pp.55-64
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• 1995

During sleep, relatively major respiratory physiological changes occur in healthy subjects. The contributions and interactions of voluntary and metabolic breathing control systems during waking and sleep are quite different Alterations of ventilatory control occur in chemosensitivity, response to mechanical loads, and stability of ventilation. The activities of intercostal muscles and muscles involved in regulating upper airway size are decreased during sleep. These respiratory physiological changes during sleep compromise the nocturnal ventilatory function, and sleep is an important physiological cause of the nocturnal alveolar hypoventilation. There are several causes of chronic alveolar hypoventilation including cardiopulmonary, neuromuscular diseases. Obstructive sleep apnea syndrome (OSAS) is an important cause of nocturnal hypoventilation and hypoxia. Coexistent cardiopulmonary or neuromuscular disease in patients with OSAS contributes to the development of diurnal alveolar hypoventilation, diurnal hypoxia and hypercapnia. The existing data indicates that nocturnal recurrent hypoxia and fragmentation of sleep in patients with OSAS contributes to the development of systemic hypertension and cardiac bradytachyarrhythmia, and diurnal pulmonary hypertension and cor pulmonale in patients with OSAS is usually present in patients with coexisting cardiac or pulmonary disease. Recent studies reported that untreated patients with OSAS had high long-term mortality rates, cardiovascular complications of OSAS had a major effect on mortality, and effective management of OSAS significantly decreased mortality.

• Korean Journal of Agricultural and Forest Meteorology
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• 제11권4호
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• pp.135-142
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• 2009

In order to predict frostfall, nocturnal cooling rate and air temperature changes were analyzed on days with and without frost when the maximum temperature was lower than $20^{\circ}C$. In general, the nocturnal cooling rates on frosty days were higher than those on non-frosty days. The cooling rates averaged from 19:00 to 24:00 on frosty and non-frosty days were $1.7^{\circ}Ch^{-1}$ and $0.7^{\circ}Ch^{-1}$ respectively. As expected, the nocturnal temperature on frosty days was lower than that on non-frosty days. Especially, the midnight air temperature averaged about $3.9{\pm}1.5^{\circ}C$ on frosty days, which was lower than that on non-frosty days (i.e., $10.1{\pm}2.9^{\circ}C$). The discriminant analysis using three independent variables (i.e., total cloud amount, air temperature at 24:00, and 5-day rainfall amount) successfully classified the presence of frost with 87% accuracy.

• Journal of Korean Biological Nursing Science
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• 제2권2호
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• pp.81-89
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• 2000

To determine the optimal rotational shift system, the effect of the direction of the rotational work shifting on the nocturnal rhythm of plasma melatonin were investigated in nursing students. Two groups of nine volunteers participated as experimental subjects, and two nursing students participated as a control group. The directions of the rotational work shift were as follows: CW(clockwise)-shift were rotated in the direction of day shift(3 days), evening shift(3 days), off duty(1 day) and night shift(5 days), and CCW(conuterclockwise)-shift were done in the reverse direction. Plasma melatonin concentrations was measured by radioimmunoassay. The results were as follows : The plasma melatonin levels were kept low at night and in the following morning in the CW night shift workers, whereas the level started to increase at 05 : 00 hr in two workers of four CCW shift workers. These result suggests that the shift rotation in the CW direction is more acceptable in terms of the adaptation of hormonal rhythms. These results indicate that the CCW rotation of shift work is somewhat better than CCW rotation for the adaptation to shift work on hormonal aspects in nurses.

• Korean Parent-Child Health Journal
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• 제12권1호
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• pp.77-87
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• 2009

Purpose: The purpose of this study was to determine the knowledge of nocturnal emissions, or wet dreams and to provide information for developing a wet dream education program for elementary school boys. Method: The research design was a descriptive study through questionnaires. Data was collected from May 10, 2009 to May 20, 2009. A total of 197 late elementary school boys in Incheon, Korea participated in this study. Data was analyzed using the SPSS WIN 15.0 program. Result: The results of this study were as follows; Knowledge of wet dreams in late elementary school boys was low; The mean of the information about wet dreams was 14.00 on a 100 point scale; There were significant differences of knowledge regarding wet dreams according to the educational experience at 6 items and wet dreams experience at 12 items of total 21 items. This indicates that present education for wet dreams is not efficient and does not provide appropriate information when they need practical information. Conclusion: Self education learning program for wet dreams should be developed for late elementary school boys which includes different contents and time required for further study, evaluation and assessment.

• Sleep Medicine and Psychophysiology
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• 제15권2호
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• pp.67-70
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• 2008

Overlap syndrome can be defined as a coexistence of chronic obstructive pulmonary disease (COPD) and sleep apnea-hypopnea syndrome (SAHS). The association of COPD and SAHS has been suspected because of the frequency of both diseases. Prevalence of COPD and SAHS is respectively 10 and 5% of the adult population over 40 years of age. However, a recent study has shown that the prevalence of SAHS is not higher in COPD than in the general population. The coexistence of the two diseases is only due to chance. SAHS does not affect the pathophysiology of COPD and vice versa. Prevalence of overlap syndrome is expected to occur in about 0.5% of the adult population over 40 years of age. Patients with overlap syndrome have a more profound hypoxemia, hypercapnia, and pulmonary hypertension when compared with patients with SAHS alone or usual COPD patients without SAHS. To treat the overlap syndrome, nocturnal noninvasive ventilation (NIV) or nasal continuous positive airway pressure (nCPAP) can be applied with or without nocturnal oxygen supplement.