• Journal of The Korean Association For Science Education
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• v.38 no.4
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• pp.481-494
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• 2018

This study investigated elementary students' understanding of Earth revolution and its accompanied apparent motion of constellation in terms of spatial reasoning. We designed a set of multi-tiered constructed response items in which students described their own idea about the reason of consecutive movement of constellations for three months and drew a diagram about relative locations of the Sun, the Earth, and the constellations. Sixty-five sixth grade students from four elementary schools participated in the tests both before and after science classes on the relative movement of Earth and Moon. Their answers to the items were categorized inductively in terms of transforming frames of reference which are observed on the Earth and designed from the Space-based perspective. We analyzed those categories by the levels of spatial reasoning and depicted the change of students' levels between pre/post-tests so that we could get an idea on the preliminary developmental pathway of students' understanding of this topic. The lower anchor description was that constellations move around the Earth with geocentric perspective. Intermediate level descriptions were planar understanding of Earth movement, intuitive idea on constellation movement along with the Earth. Students with intermediate levels did not reach understanding of the apparent motion of constellations. As the upper anchor description students understood the apparent motion of constellations according to the Earth revolution and could transform their frames of reference between Earth-based view and Space-based view. The features as the case of evolutionary learning progressions and critical points of students' development for this topic were discussed.

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.100-107
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• 2003

Objectives: Periodic leg movements in sleep (PLMS) might be subdivided based upon whether or not they are associated with visible EEG microarousals (MA). MA is considered to be responsible for nonrestorative sleep and daytime fatigue. The American Sleep Disorders Association's (ASDA) scoring rules for MA based on visual analysis of the EEG changes suggest that MA should last more than 3 seconds. However, it has been suggested that visual analysis may not detect some changes in EEG activity. This study is aimed at measuring changes in EEG spectra during PLMS without MA in order to better understand the arousing response of PLMS. Methods: Ten drug-free patients (three men and seven women) diagnosed with PLMS by polysomnography were studied. Spectral analysis of the EEG was performed in each patient on 30 episodes of PLMS without MA, chosen randomly across the night in stage 2 non-REM sleep. We applied stricter criteria for MA compared to ASDA, by defining it as a return to alpha and theta frequency lasting at least 1 second. Results: The mean PLMS index was $16.7{\pm}10.0$. The mean PLMS duration was $1.3{\pm}0.7$ seconds. Comparison of 4-second EEG activity both before and after the onset of PLMS without MA using independent t-test showed that the movements were associated with significant increase of relative activity in the delta band (p=0.000) and significant decrease of activity in the alpha (p=0.01) and sigma (p=0.000) bands. No significant decrease in the theta (p=0.05), beta (p=0.129), or gamma (p=0.062) bands was found. Conclusion: PLMS without MA was found to be associated with EEG change characterized by increase in the delta frequency band. This finding seems to be compatible with the hypothesis of an integrative hierarchy of arousal responses of Sforza's. Considering that the subjects had lower PLMS index and shorter PLMS duration than those of the previous study, it is suggested that an even less severe form of PLMS without MA could induce neurophysiologic change, which may potentially be of clinical significance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.2
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• pp.197-204
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• 2012

This study examined the protective effects of an ethanol extract of Youngia denticulata leaf (YDL) and Youngia denticulata root (YDR), and Youngia sonchifolia leaf (YSL) and Youngia sonchifolia root (YSR) on acute ethanol-intoxicated rat. The rats were pretreated with an ethanol extract of YDL, YDR, YSL and YSR for 4 weeks before being exposed to ethanol (5 g ethanol, po/kg BW). The biochemical indices (hepatic alcohol metabolic enzymes and serum ALT activities, and hepatic and serum lipid profiles) were examined to evaluate the protective effects. The hepatic ADH activities in all experimental groups were not changed significantly by acute ethanol after a pretreatment with the YS and YD ethanol extracts. In contrast, the ALDH activity in EC (ethanol control) was higher than that of NC (normal control); these activities in the YDL and YSL groups were significantly higher than that of the EC group. On the other hand, acute ethanol exposure resulted in a significant increase in the serum TG, total cholesterol, LDL-cholesterol, hepatic TG, total lipid and cholesterol levels, and serum ALT activity, and a decrease in the serum HDL-cholesterol. A pretreatment with the YS and YD ethanol extracts dramatically attenuated these adverse effects. In particular, the YDL pretreatment markedly suppressed the ethanol-induced increase in the serum and hepatic TG and total cholesterol levels. Furthermore, serum ethanol was decreased by a pretreatment with YSL, YSR, YDL, or YDR. Overall, YD and YS ethanol extracts attenuate acute ethanol-induced hyperlipidemia and fatty liver significantly. Nevertheless, further study will be needed.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.922-928
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• 2010

There is a little information on the effect of calcium cloride ($CaCl_2$) which is used as deicing salt in Korea on the physiological responses of the street trees. Prunus sargentii is one of the most widespread tree species of street vegetation in Korea. In this study, the effect of $CaCl_2$ on photosynthetic apparatus such as chlorophyll fluorescence image and light response curve of P. sargentii in relation to their leaf and root collar growth responses were investigated. To study the effect of $CaCl_2$ treatment in the early spring, we irrigated twice in rhizosphere of P. sargentii (3-year-old) planted plastic pots with solution of 0.5%, 1.0%, 3.0% $CaCl_2$ concentration before leaf expansion. Results after treatments, total chlorophyll contents and the chlorophyll a/b, photosynthetic rate, quantum yield, dark respiration decreased with increasing $CaCl_2$ concentration. On the contrary, light compensation point increased with increasing $CaCl_2$ concentration. Through the linear regressions of correlation of photosynthetic rate with photosynthetic parameters (quantum yield, dark respiration and light compensation point), we found a significant relationship (p<0.05) between photosynthetic rate and quantum yield and light compensation point except dark respiration. Calcium cloride ($CaCl_2$) induced inhibition of photochemical efficiency ($F_v/F_M$) and non-photochemical quenching (NPQ) were found in treatments of $CaCl_2$, and these reduction rates between control and CaCl2 treatments were drastically showed at 80 days. We suggest that physiological activities are limited from treatment of $CaCl_2$. These reductions of photosynthetic apparatus ability caused eventually the reduction of leaf and diameter at root collar growth.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.964-970
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• 2008

Purpose : Methylmalonic aciduria (MMA) and propionic aciduria (PA) are inborn errors in the catabolism of branched-chain amino acids. The study was undertaken to investigate the genotypes and clinical features of Korean patients with MMA and PA. Methods : This study examined 12 patients with MMA and eight with PA. We analyzed various clinical features, laboratory findings, treatments, and neuro-developmental outcomes. Diagnoses were based on the presence of characteristic compounds detected by amino acid analysis in serum and organic acid analysis in urine. Mutation analysis was performed in the genes of MUT, MMAA, MMAB, and MMACHC for MMA and PCCA and PCCB for PA. Results : Among the 20 patients, six patients were diagnosed before one month of age and nine patients were diagnosed after the newborn period. Five patients were diagnosed via a neonatal screening test. Patients with early-onset forms had more severe illness at presentation and generally poor outcomes. A favorable outcome was obtained in 55% patients; most of them were of a late-onset type or diagnosed by neonatal mass screening test without symptoms. Genotypes were confirmed in all patients with MMA. We detected 11 different mutations by MUT gene analysis in 10 patients, and three different mutations in MMACHC genes in two patients. PCCA and PCCB gene mutations were identified in 14 of the 16 alleles, in eight patients with PA. Conclusion : Organic aciduria is a fatal disease; however, better outcomes are expected whenever early diagnosis and prompt management are made possible. Mutation analysis is useful for confirming diagnoses and planning management strategies.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.151-157
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• 2012

General treatment for cholangiocarcinoma is complete surgical resection. However recurrence is common in those patients. In most of cases the purpose of the treatment for patients with recurrent is palliative. Therefore we adopt intraluminal catheter to treat a recurrent patient with high-dose-rate intraluminal brachytherapy. This study aims to evaluate the treatment procedure and set-up reproducibility of intraluminal brachytherapy in the recurrent patient. Study patient was diagnosed at rcT1N0M0 and undergone intraluminal brachytherapy after Arrow Sheath insertion. 3 Gy was delivered in every fraction with a total dose of 30 Gy. We planned dose normalization at distal, proximal and central axis point of narrowed bile duct far from 1 cm. To evaluate set-up reproducibility, we measured distance between distal, proximal treatment target volume point and anterior surface of the thoracic vertebral body respectively for five times before every treatment with dummy seed insertion. Mean distance between distal, proximal treatment target volume point and anterior surface of 10th and 11th thoracic vertebral bodies is 0.5 cm, 6.1 cm and standard deviation is 0.06, 0.08 respectively. In addition, set-up reproducibility was maintained significantly. The patient has been alive with no evidence of disease recurrence for more than a year and has not yet reported severe complications. In conclusion, high-dose-rate intraluminal brachytherapy for unresectable recurrence of cholangiocarcinoma maintains high set-up reproducibility without severe side effects.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.169-176
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• 2010

Purpose : We aimed to evaluate predictive parameters for non-response to intravenous immunoglobulin (IVIG) in patients with Kawasaki disease (KD) before IVIG use using two controls. Methods : We evaluated 229 consecutive KD patients who were treated with 2 g/kg of IVIG at a single center. Those who had persistent fever >24 hours after IVIG infusion made up the 23 IVIG non-responders; the first control included a total 206 defervesced cases and the second control included 46 cases that were matched for age and pre-treatment fever duration to non-responders. Results : Demographic and clinical characteristics were similar in IVIG non-responders and responders at presentation. As for laboratory findings, the neutrophil differential, CRP, AST, ALT, and LDH were higher, and lymphocyte differential, total protein, albumin, platelet count, and total cholesterol were significantly lower in IVIG non-responders compared to responders by univariate analysis in both study designs. However in multivariate analysis, non-responders showed a significantly higher neutrophil differential (cutoff value, >77%, sensitivity 68.4% and specificity 79.5%) and lower cholesterol (<124 mg/dL, sensitivity 79% and specificity 70.5%). Whereas plasma albumin (<3.6 g/dL, sensitivity 73.7% and specificity 60%) was the sole laboratory parameter of non-responders in the second study design. Conclusion : Severity of inflammation in KD was reflected by higher or lower laboratory values at presentation. Because the multivariate analysis for these indices may be influenced by some confounding factors, including the numbers of patients of different ages and fever duration, other assessment modalities are needed for KD patients with the greatest risk of coronary artery lesions.

• Journal of Preventive Medicine and Public Health
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• v.25 no.4 s.40
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• pp.343-356
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• 1992

Authors studied the workers' knowledge about the health problems detected through the previous workers' periodic health examination, content of follow-up management ana actions taken for their health problem detected on previous health examination. From June to September 1992, workers' periodic health examination was peformed on workers employed in 10 companies located in 2 middle-sized Korean cities. A questionnaire survey was done far 150 workers who reported to have $D_2$ result of either hypertension or liver disorder at the previous workers' periodic health examination done in 1991. The results are as follows; 1. Of 160 workers who had $D_2$ result of either hypertension or liver disorder in previous examination one year before, only 85 workers(51.3%, 43 workers with hypertension, 38 workers with live disorder) responded that they have such disorders. The other 65 workers responded to questionnaire were all those with C results. Respondents' knowledge about their diagnoses was relatively precise (95.2% in hypertension group, 94.6% in liver disorder group) but knowledge about classification of diseases was poor. 2. The main efforts to solve the health problem nab self management (20 spells, 55.3%), visiting clinic or hospital(6 spells, 12.8%), use of herb medicine (2 spells, 4.3%) and use of drug store(2 spells, 4.3%) in hypertension group. In liver disorder group, 30 spells (71.4%) relied on self management,6 spells (14.3%) on hospital or clinic and 9 spells (21.4%) had no effort to improve the health problem. Content of self management was low salt diet, quit smoking, regular exercise and quit alcohol drinking in order. Avoidance of salt in diet was high in hypertension group and quitting alcohol drinking was high in liver disorder group. In those with self management, 80.7% of hypertension group and 83.3% of liver disorder group continued previous effort. Those, however, who utilized clinic or hospital, only 16.7% and 50.0% were still visiting hospital or clinic. 3. Fifty seven percent of hypertension group and 64.3% of liver disorder group was presently smoking,8.5% and 11.9% reduced smoking and 21.3% and 14.3% stopped smoking. Forty nine percent of hypertension group and 28.6% of liver disorder group was presently drinking. Reduced alcohol intake was reported in 29.8% and 40.5%, 12.8ole and 23.8% stopped alcohol drinking. Sixty six percent of hypertension group and 73.8% of liver disorder group did no regular exercise, but 12.8% and 11.9% of each group increased their physical exercise far last one year. Forty three percent of hypertension group and 38.l% of liver disorder group was overweight (defined by bodymass index greater or equal than 25). Reduced body Weight was reported in 17.2% and 16.7% of each group. Reduced dietary salt intake was high in hypertension group (51.5%). The study results suggest that follow-up management after workers' periodic health examination is not satisfactory. In order to improve this situation, adequate information on the result of the workers' periodic health examination should be distributed to each worker group with health education and counselling.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.10.1-10
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• 1982

The use of phonosurgery in the recent development of laryngomicrosurgery has enabled the restoration of a normal voice in respect to functional laryngeal surgery which in Korea in the past limited to simple removal of benign laryngeal tumor such as laryngeal polyp or nodules and cordal injection of $Teflon^{{\circledR}}$ for the treatment of recurrent nerve paralysis under the vision of suspension laryngoscopy. Performance of phonosurgery for the treatment of cord paralysis, mutational dysphonia, vocal cord atrophy, hyperkinetic dysphonia and sulcus vocalis is a happy event in the view point of development of phonosurgery in Korea. In this aspect thyroplasty to change the position and physical characteristics of the cord outside the glottis instead of the direct handling of the vocal cord through direct endoscopy is popular. Among the 4 types of thyroplasty, classified by Insshiki(1974), type I thyroplasty(1ateral compression of vocal cord) and type IV thyroplasty(lengthening of vocal cord) were effective in the treatment of unilateral vocal cord paralysis. Advantages of this operation are the fine adjustment of the degree of lateral compression under local anesthesia according to the phonation of the patient during operation and avoidance of dyspnea and intralaryngeal hemorrhage due to the manipulation outside the internal perichondrium of the thyroid cartilage. We did 7 cases of thyroplasty for the treatment of unilateral vocal cord paralysis in the 7 months from September 1981 to March 1982. Before the operation aerodynamic study, psychoacoustical evaluation, stroboscopy and sound spectrographic analysis were done. Two months after the operation the above procedures were performed again. Results of preoperative and postoperative examination were compared and the following results were obtained. 1) In the aerodynamic study, maximum phonation time increased to 158% of the preoperative value and the phonation quotient and the mean flow rate decreased to 58% and 54% of preoperative values. 2) The degree of hoarseness improved in the psychoacoustical evaluation and the glottic chink during phonation was decreased in the stroboscopic examiantion. 3) In the sound spectrographic analysis, periodicity was much restored and noise distribution decreased especially in the high frequency area.

• Economic and Environmental Geology
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• v.39 no.1 s.176
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• pp.63-74
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• 2006

In order to identify the Pb pollution and its sources in continental shelf and slope areas, Pb concentration and Pb isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were determined far 6 box corer sediments collected from the southern East/japan Sea. Pb concentration, and $^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$ ratios were constant at around $25\pm5 ppm$ and 0.842 and 2.092 from 1700 to 1930 year, respectively and increased steadily up to $40\pm5 ppm$ and 0.867 and 2.123 at the beginning of 1990s', respectively. The increase of concentration and isotope ratios in the labile fraction (leached by 2M HC1+0.5M $HNO_3$) explains their increase in bulk sediments, while Pb concentration and isotope ratios in the residual fraction were nearly constant during 300yrs. Temporal variation of Pb isotope ratios was explained by simple two end-members mixing of geo-genic and anthropogenic sources because isotope ratios and the inverse of Pb concentration showed the good linear relationships. Using Pb isotope ratios, we can constrain two Pb sources in the study area. The one is atmospheric particulates, compared with mean values of isotope ratios in atmospheric particulates collected at Jeju and Oki ;stands, based on the history of Pb emmission in Korea and China, and judged by oceanographic processes capable of homogenizing many sources. The other is local sources related to iron mills, refineries of Pb ore and of petroleum located at the coast of the study area. Isotope ratios of anthropogenic Pb can be estimated using two end-members mixing equation and were $0.879\pm0.005\;and\;2.144\pm0.008$ before 1950s' while they increased up to $0.900\pm0.008\;and\;2.162\pm0.011$ after 1980s', respectively.