• Childhood Kidney Diseases
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• v.8 no.2
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• pp.195-204
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• 2004

Purpose: Hypophosphatemic rickets is a hereditary disease, characterized by hypophosphatemia due to renal phosphate wasting, impaired renal production of 1,25-dihydroxyvitamin $D_3$, rachitic bone deformities and impaired growth. The purpose of this study is to provide clinical profiles of patients with hypophosphatemic rickets in our hospital. Methods: Between July 1983 and February 2004, 56 patients were diagnosed as having hypophosphatemic rickets. The medical records of these patients were reviewed retrospectively. Clinical manifestations, family histories, laboratory data, treatment outcomes were described. Results: Fifty six patients were enrolled in this study. The average age at symptom onset and diagnosis were 20 months and 5 years respectively. Fourteen patients had family histories. The main clinical manifestations were bow legs and short stature. There was a significant negative correlation between the ages and the height z-scores at the time of diagnosis(r=-0.47, P=0.005). Initial laboratory data showed normocalcemia, hypophosphatemia, elevated serum alkaline phosphatase, decreased tubular reabsorption of phosphate and a normal range of 1,25-dihydroxyvitamin $D_3$ Radiographic examinations of bone revealed fraying, widening and cupping of the metaphyseal ends. Treatment consisted of Joulie solution and vitamin D metabolites, and resulted in improved biochemical and radiographic findings. However, height z-scores remained essentially unchanged(P=0.224). Complications of treatment were frequently observed, including hyperparathyroidism, nephrocalcinosis, and hypercalciuria. Sixteen patients had corrective osteotomy and 4 of them underwent leg lengthening together. Conclusion: There was a gap of several years between the onset of symptoms and the diagnosis. Early treatment seems to be essential to growth. For the earlier treatment, the offsprings of affected parents should be followed up closely.

• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.31-39
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• 2016

Purpose: The aim of this study was to investigate the prognostic factors for Pneumocystis jirovecii pneumonia (PCP) and to evaluate the influence of PCP prophylaxis in pediatric patients. Methods: From January 2002 to April 2015, patients aged <18 years with a diagnosis of confirmed PCP at our institute were reviewed retrospectively. Clinical characteristics and outcomes were compared according to the groups with or without PCP prophylaxis. Risk factors associated with PCP-related death were analyzed by logistic regression analysis. Results: During study period, a total of 24 patients were diagnosed with PCP by immunofluorescence assay and/or PCR. The median age of the patients was 5 years (range, 3 months-18 years) and 23 (96%) had immunocompromised conditions including hematologic disorders with or without hematopoietic stem cell transplantation (n=15), solid organ transplantation (n=4), and primary immune deficiency (n=4). Most common presenting symptoms were tachypnea and cough (92%, each). At the time of diagnosis, 79% (19/24) and 25% (6/24) suffered from respiratory failure and multi-organ dysfunction syndrome (MODS), respectively. Mechanical ventilation was required in 8 (33%) patients and 5 (21%) patients died of PCP. Multivariate analysis showed that MODS at initial presentation was an indicator of poor prognosis (OR, 17.1 [95% CI 1.13-257.67]; P=0.04). Compared to the patients without PCP prophylaxis, the frequency of MODS at diagnosis, need for mechanical ventilation and length of hospital days were significantly less common in the children who received PCP prophylaxis. Conclusions: MODS at presentation was a significant predictor for poor outcome and PCP prophylaxis could alleviate the clinical courses of pediatric PCP. Prospective study will be mandatory to determine the risk factors for development and deterioration of PCP in children.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.163-170
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• 2015

The interest of the people in the radioactive contamination of the water has increased significantly and the study about analysis and management of radioactive materials are being actively conducted. And monitoring spots have been expanded to the range of public water as well as drinking water by publishing the rule of drinking water quality standards and examination in the Environmental Enforcement Ordinance No. 553 of Korea. In this study, US EPA was investigated as the foreign advanced cases and the way that is appropriate for the Korea was sought by analyzing investigate radionuclide, interval and management. As a result, in the selection part of investigate radionuclide, geological survey, status of nuclear power plants and the presence of the use of artificial radionuclides of the Korea should be investigated and additionally after the selection of a few radionuclides, the systems should be extended to cover all possible radionuclides by considering radioactive pollution levels in humans may be exposed due to the annual drinking water. In the part of the investigate interval, the concept(MCL, DL) should be set up for preventing concentration detection of above MCL and it needs to the maintenance and management. For example, when the concentration is more than MCL, it should be investigated on a quarterly and when the concentration is lower than MCL, it should be investigated to each different interval and management. And the US EPA divided the management area and make the roadmap for managing drinking water. The each classified area has been organized to match the state budget and labor force and the individual data have been managed effectively by HPGe, the NaI, TLD and so on.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.49-61
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• 1994

As the groundwater flows along the fractures of crystalline rocks, it will be in contact with the fracture walls mostly coated by secondary minerals which are quite different form those of host rocks. The presence of fracture-filling minerals in crystalline rocks is important on the view point of radioactive waste disposal because of their great surface reactivity. The Surichi drill hole of 200 m in depth in the Yugu area composed mainly of Precambrian gneiss was selected to study the formation process of clay minerals on the fracture wall of gneiss, and their relation with present groundwater. The water-rock interaction in fractures resulted in the formation of gibbsite and clay minerals. They are formed by two different processes : (1) Incongruent dissolution of feldspar by groundwater diffused from a fracture path into rock matrix produced smectite and illite in situ, (2) on the wall of fracture, gibbsite, kaolinite, smectite and illite are formed by precipitation of dissolved species in groundwater. They show the paragenetic sequence such as gibbsite${\leftrightarrow}$kaolinite${\leftrightarrow}$smectite or illite. The paragenetic sequence of fracture-filling minerals was controlled by increase of pH of groundwater, decrease of fracture permeability by precipitation of fillings, and immobility of alkali or alkaline earths in groundwater. The groundwater from the Surichi borehole is a $Na-HCO_{3}$ type with pH range of 8.6-9.2. The sodium and bicarbonate in groundwater would be supplied by the dissolution of albite and calcite, respectively. The saturation index of groundwater and surface water calculated by WATEQ4F indicates that gibbsite and kaolinite are under precipitation to equilibrium state, and that smectite and illite are under equilibrium to redissolution environment. The stability relation of clay minerals in the $Na_{2}O-Al_{2}O_{3}-SiO_{2}-H_{2}O$ system shows that kaolinite is stable for all waters.

• 대한공업교육학회지
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• v.45 no.2
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• pp.21-45
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• 2020

The purpose of this study was to verify how the vocational education for training industrial workforce as a national human resource development (NHRD) system has undergone a transition process in relation to the national economic, industrial, and socio-cultural contexts. First, how vocational education as an industrial workforce training system has changed in accordance with Korea's economic environment, industrial development, and social changes; second, what are the main factors that influenced the role and importance of vocational education; and third, vocational education as a system for training industrial workforce and training workforce in science and engineering were analyzed differently from the perspective of the NHRD model. To this end, domestic and international academic journal papers, research reports, and thesis were investigated and classified by period, and major changes in vocational education were analyzed in relation to economic, industrial, and social issues and policies by period. As a result of the research, first, as the industry advanced, the level of vocational education increased and the scope expanded. Second, vocational education tended to shrink gradually after the manufacturing industry base, and especially secondary vocational education tended to decline after the national industry focused on light industry. Third, since the 1970s, the diversification of the NHRD and jobs has resulted in wage gaps depending on the level of education, which has increased the preference for university education and avoided secondary vocational education. In addition, a NHRD model focusing on training science and engineering workforce was proposed to compare the existing NHRD model focusing on overall vocational education, and it was revealed that the NHRD needs to be subdivided into various fields or levels to derive a model and examine changes. From the results of the study, vocational education in Korea, especially in secondary vocational education, has declined due to large impacts on socio-cultural perception due to economic growth, enthusiasm for education, and external shocks such as the financial crisis, and the long-term effort to change this perception is suggested to overcome the crisis of vocational education.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.440-446
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• 2003

Purpose : The genetic disturbance of galactosemia is expressed as a cellular deficiency of either galactose-1-phosphate uridyltransferase(GALT) or galactokinase(GALK) or UDP galactose 4-epimerase(GALE). To find-out the pattern of galactosemia in Korea, we retrospectively analyzed cases of galactosemia detected by neonatal screening program. Methods : We analyzed medical records of patients who visited Soonchunhyang University Hospital at age of 1 month after showing abnormalities in neonatal screening of galactosemia. For accurate diagnosis, galactose was measured by enzyme immunoassay(EIA) and fluorophotometer, also galactose-1-phosphate by fluorophotometer. Enzyme activities of GALK, GALT and GALE in RBC and galactose-1-phosphate were measured by radioisotope assay(RIA). Beutler test were done. Patients went on a lactose-free diet and follow-up tests for galactose, galactose-1-phosphate level and enzyme activity were performed. Results : 10 patients(male : 6, female : 4) were diagnosed as galactosemia. Two patients had GALK deficiency and two had GALT deficiency. Six were GALE deficient showing the largest number. In two patients with GALK deficiency, GALT and GALE activities were normal but GALK activities showed respectively reduced activity. For GALT deficiency, two patients had low GALT activity in RBC and showed genotype of Duarte 2/G(galactosemia) in DNA analysis. In one patient, GALT activity was normal. Three patients seemed to be heterozygote state of GALE deficiency according to GALE activity levels. Four patients showed GALK hyperactivity. Conclusion : GALE deficiency provided the highest number. After lactose-free diet, galactose and galactose-1-phosphate were normaly maintained. Neonatal screening on galactosemia is essential for preventing life-threatening symptoms and an accurate diagnosis is needed for finding out the type of galactosemia which is important for prognosis.

• Composites Research
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• v.12 no.4
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• pp.71-78
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• 1999

To determine the effect of chemical structure of linear amine curing agents on thermal and mechanical properties, standard epoxy resin DGEBA was cured with diaminodiphenyl methane (DDM), diaminodiphenyl sulphone (DDS) in a stoichiometrically equivalent ratio. From this work, the effect of aromatic amine curing agents. In contrast, the results show that the DGEBA/DDS cure system having the sulfone structure between the benzene rings had higher values in the conversion of epoxide, density, shrinkage (%), glass transition temperature, tensile modulus and strength, flexural modulus and strength than the DGEBA/DDM cure system having methylene structure between the benzene rings, whereas the DGEBA/DDM cure system presented higher values in the maximum exothermic temperature, thermal expansion coefficient, and thermal stability. These results are caused by the relative effects of sulfone group having strong electronegativity and methylene group having (+) repulsive property and stem from the effect of the conversion ratio of epoxide group. The result of fractography shows that the each grain size of the DDM/DGEBA system with feather-like structure is larger than that of the DDS/DGEBA system.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.194-205
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• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.1-13
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• 1969

A total of 129 surface(upto 30 cm depth) soil samples were selected from the profile samples collected during reconnaissance soil survey in 1967, for the determination of phosphorus absorption co-efficient. The distribution range for each soil association has been established. The physicochemical factors affecting the phosphorus absorption coefficient have also been examined. The following general conclusions can be drown: 1. In general, the phosphorus absorption coefficient of the soil association of presently arable land are lower than the soils which are not in cultivation. 2. The higher the cation exchange capacity of soils, the higher is the phosphorus absorption coefficient. The factors governing phosphorus absorption coefficient in various soil associations are as follows: Parent Material Soil Association Governing Factor Fluvio marine Low Humic Gley Fluvio marine Alluvial Complex Narrow valley Siliceo mafic materials Red-yellow podzolic Redish Siliceo mafic materials Brown Lateritic Clay content Siliceous crystalline materials Lithosols C.E.C. & Clay content Alluvium Low Humic Alluvium Gley Alluvial Organic matter Siliceous crystalline materials Red-Yellow Podzolic Organic matter and clay content 4. The relation between phosphorus absorption coefficient determined by $(NH_4)_2HPO_4(y)$ and by the P 700 ppm $NaH_2PO_4(x)$ is $Y=2.716X+37(r=0.96^{**})$ which shows highly significant positive correlation and linear regression.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.524-529
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• 2004

Background: Since the Nuss procedure for the correction of pectus excavatum is in its early stage, there have been problems that need to be solved. We examined complications in a single-institute experience of the Nuss technique in order to develop possible solutions to prevent them. Material and Method: 335 consecutive patients, who underwent the modified Nuss procedure between August 1999 and October 2002, were studied retrospectively. Median age was 8 years (range 1 to 46). 264 patients (78.8%) were in pediatric group (age$\leq$15) and 71 patients (21.2%) were in adult group (age> 15). 193 patients (57.6%) had symmetric and 142 patients (42.4%) had asymmetric pectus configurations. Risk factors predicting postoperative complications were analyzed using multi-variate logistic regression. Result: Postoperative complication rates were 18.9% (61/335) in total patients. Frequent complications were pneumothorax 24 (7.5%), bar displacement 11 (3.4%), and wound seroma 10 (3.1%) in order. Early complications (within a month, 49 cases, 15.2%) were pneumothorax (n=23, 6.9%), wound seroma (n=12, 3.6%), and bar displacement (n=8, 2.4%). Late complications (after a month, 12 cases, 3.7%) were pericarditis and pericardial effusion (n=5, 1.5%), bar displacement (n=4, 1.2%), and hemothorax (n=3, 0.9%). Techniques were modified to prevent complications especially in bar shaping and fixation, which led to decrease complication rate in later experience (Operation Date 1: 15/51 (29.4%) vs Operation Date 2: 34/284 (12.0%), p=0.004). Grand Canyon type (eccentric long canal type) showed higher complication rate than other types (GC type: 12/30(40%) vs Others: 37/305 (12.1%), p<0.001). Major risk factors are severity of pectus (OR=2.88, p=0.038), Grand Canyon type (OR=2.82, p=0.044), and Op. Date 1 (OR=4.05, p=0.001). Conclusion: Major complications were related to severe eccentric type of pectus configuration (Grand Canyon type) and lack of surgeon's experience (Op. Date 1). Com-plication rate was reduced with accumulation of experience and advancement of surgical techniques. The Nuss procedure can be performed at a low risk of complications with our current technique.