• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1188-1193
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• 2007

Purpose : The prevalence of rickets in the world is on the rise not only in developing but also in developed countries. In Korea, breastfeeding has increased. There have been few studies on the possible association of rickets with breastfeeding. The purpose of this study was to identify the development and the clinical presentation of subclinical rickets in breastfed infants. Methods : We investigated patients who were breastfed and had hypovitaminosis D in the blood from May 2006 to April 2007, and who were diagnosed with vitamin D deficient rickets from May 2003 to April 2006. We evaluated the results of blood tests, x-rays and other relevant information in the medical record. A questionnaire that included questions on the diet of patients, the mothers activity during pregnancy and place of residence was administered. Results : Twelve patients (66%: male, 34%: female) were enrolled in this study. There were eight in the asymptomatic and four in the symptomatic group. The median age for each group was 8 months (range 4-11 month) and 5.5 months (5-8 month). All patients in the symptomatic group were breastfed until diagnosed. In the asymptomatic group, they were breastfed for four to six months, and then weaned with only thin rice soup and vegetables. Nine patients had a vitamin D concentration below 20 ng/mL and three patients had levels between 20 and 29 ng/mL. Alkaline phosphatase (ALP) and parathyroid hormone (PTH) were elevated in both groups. There were statistically significant $25-OHD_3$ levels in the blood in both groups (P=0.008). Ten of the patients (83%) also had iron deficient anemia. Conclusion : Vitamin D deficiency and subclinical rickets has been identified in Korea. However, the prevalence of this disease has not been determined. The main limitation of this study was the small number of patients and the absence of a control group.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1058-1064
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• 2008

Purpose : This study aimed to assess current knowledge of and training experiences with the intraosseous (IO) line among emergency medicine (EM) and pediatric residents who care for critically ill children and to evaluate the educational effectiveness of the IO line workshop. Methods : During May and June 2008, a workshops on IO line insertion was held for EM and pediatric residents. The workshop comprised a 45-min lecture and a 15-min hands-on session. A semi-drill type EZ-IO machine was used for education. Self-assessment questionnaires gauged residents knowledge of and experiences with IO line insertion or bone marrow (BM) examination and their confidence with IO line insertion before and after the workshop. Performance tests were completed for skill evaluation. Results : Forty-five pediatric residents and 22 EM residents participated in the workshop. The pre-educational questionnaire revealed that EM residents had more educational experience in IO line insertion than pediatric residents (P<0.001), while pediatric residents reported more experience in BM examination (P<0.001). The post-educational questionnaire showed a statistically significant higher percentage of correct answers (P<0.001). Although the pediatric residents inserted an IO line more quickly (P=0.001), most residents (88.7%) succeeded in IO line insertion on their first attempt; there was no difference in the groups success rates. Both groups showed higher confidence in performing IO line insertion after training (P<0.001). Conclusion : Observed educational effectiveness in both knowledge and confidence of IO line insertion skill suggest educational opportunities for pediatric and EM residents should be increased.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.405-416
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• 2017

This study evaluated a model unconfined aquifer comprising a sand or gravel layer, a filter layer, a pumping well, and an observation well. The model was employed in step drawdown tests and then used to assess the permeability of each test tank. The optimal yield and well efficiency were then calculated. Evaluation of yield by step in sand layer filters of equal thickness gave optimized watering rates of 22.03 L/min in the double filter and 19.71 L/min in the single filter. The double filter's yield was 115.0% that of the single filter. A comparison of double and single filters, each 10 cm thick, showed the double filter to have a maximum yield of 182.7%. Yields for the gravel layer were 73.56 L/min for a double filter and 65.47 L/min for a single filter of the same thickness; the former value is 112.3% of that of the latter. Comparison of double and single filters with 10-cm-thick gravel layers revealed that the double filter had a maximum yield of 160.9%. Results for sand wells showed the double filter to have a maximum efficiency of 70.4% and the single filter to have a minimum efficiency of 37.1%. Gravel-layer well efficiencies were >66.5% for both double and single filters (each 30 cm thick), but only 22.5% for a 10-cm-thick single filter. This study confirms that permeability improved as the filter material became thicker; it also shows that a double filter has a higher yield and well efficiency than a single filter. These results can be applied to the practical design of wells.

• Clinical and Experimental Pediatrics
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• v.48 no.6
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• pp.619-623
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• 2005

Purpose : Bacteremia in immunocompromised pediatric cancer patients can lead to high morbidity and mortality, if not treated early and properly. The incidence and antibiotic sensitivities to common pathogens of bacteremia in pediatric cancer patients are liable to change, according to region and time. We investigated the causative organisms and antibiotic sensitivities of bacteremia in pediatric cancer patients to assess the adequacy of empiric antimicrobial therapy. Methods : From September 1995 to August 2003, we retrospectively evaluated 58 episodes in 39 pediatric cancer patients with bacteremia treated at the Pediatric Department of Yeungnam University Hospital. We investigated and analyzed the causative organisms and the antibiotic sensitivity test results by reviewing the records of the microbiologically proven positive blood culture results. Results : The incidence of bacteremia in pediatric cancer patients in this study was 5.7 percent (58 episodes out of 1,022 occasions of blood cultures). Gram-positive organisms were isolated more often than gram-negative organisms (63.8 percent vs 36.2 percent) in the following order : Staphylococcus epidermidis (37.9 percent), Staphylococcus aureus (17.3 percent), Escherichia coli (12 percent), Streptococcus (8.6 percent), Enterobacter (6.9 percent), Klesiella (6.9 percent), Serratia (3.5 percent), Acinetobacter (3.5 percent), Proteus (1.7 percent) and Morganella morganii (1.7 percent). In antibiotic sensitivity tests, only six of 37 isolates (16 percent) of gram positive bacteria were sensitive to penicillin and 15 of 37 isolates (40 percent) were sensitive to oxacillin. All except one Staphylococcus aureus were sensitive to vancomycin and all except one Staphylococcus epidermidis were sensitive to teicoplanin among 37 isolates of gram positive bacteria. In the case of gram negative bacteria, two of 21 isolates (10 percent) and four of 21 isolates (19 percent) were sensitive to cefotaxime and ceftazidime, respectively. Only six of 21 isolates (29 percent) were sensitive to aminoglycoside, but all 21 isolates (100 percent) were sensitive to imipenem. All seven isolates tested after the year 2000 were sensitive to meropenem. Conclusion : In conclusion, we should choose the proper antimicrobials in treating pediatric cancer patients with suspected bacteremia, reflecting the increasing episodes of gram positive bacteremia and polymicrobial resistance of gram positive and negative organisms.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.976-985
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• 2005

Purpose : Although influenza is one of the most important causes of acute respiratory tract infections in children, effective antiviral therapies are not common and there are only a few clinical studies on treatment of influenza in children. We evaluated the efficacy of oseltamivir in the treatment of naturally aquired influenza in children during the first half of 2004 in Busan. Methods : From January 2004 to June 2004, throat swabs and nasal washes were performed and cultured for the isolation of influenza virus and tested by rapid antigen detection test(QuickVue influenza test) in children with suspected influenza infections. The children who responded positively to the QuickVue influenza test, we divided into two groups : an oseltamivir treatment group and a control group. We compared their clinical symptoms(including fever duration) and diagnosis. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : A total of 621 individuals were suspected of influenza infection. Influenza viruses were isolated in 79(17.2 percent) out of 621 patients examined. QuickVue influenza tests were positive in 181 cases. The treatment group(83 individuals) received oseltamivir twice daily for 5 days, and the control group(99 individuals) were administered only symptom relief medicine. There was no differences between the two groups in clinical diagnosis and symptoms. Oseltamivir treatment reduced the fever duration and other respiratory symptoms. There were no adverse events associated with oseltamivir treatment. Conclusion : Our data suggest that oral oseltamivir treatment reduces the fever duration and other respiratory symptoms of acute influenza without side effects in children.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.716-722
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• 2005

Purpose : A full view of the spectrum of all bacterial diseases in healthy children is essential to the establishment of public health priorities. Accurate information on the relative importance of the various pathogens in terms of the age of the affected patients, the site of infection and the case fatality rate are valuable to the clinician in choosing antimicrobial treatments. Methods : Fifty-nine episodes of bacteremia were analysed. Data were collected at Ilsan Paik Hospital from January 2000 to December 2003. Analysis of each collected episode included isolating pathogen from blood culture, diagnosis, hospital course, isolating pathogens from other tissue sites, and studying results of antimicrobial sensitivity tests. Results : Fifty-nine cases of community-acquired bacteremia were reviewed. The most common pathogen was Staphylococcus aureus(11 cases, 18.6 percent), followed by Salmonella(10 cases, 16.9 percent), E. coli(7 cases, 11.9 percent), Streptococcus pneumoniae(five cases, 8.5 percent), Streptococcus viridans(5 cases 8.5 percent). The most common diagnosis was bacteremia without an indentified focus(61 percent), followed by meningitis(12 percent), bacteremia with enteritis(10.2 percent) and bacteremia with urinary tract infection(8.5 percent). Salmonella was still an important causative agent of bacteremia. The relative importance of Haemophilus influenza and Streptococcus pneumoniae was lower than in other studies. The most common organism responsible for bacteremia without an identified focus was Staphylococcus aureus. The case-fatality was 3.4 percent for all cases of bacteremia. Conclusion : We reviewed the etiology of community-acquired bacteremia. These data may be useful in the establishment of public health priorities and serve as a reference for selection of antibiotics in the empirical therapy of suspected invasive bacterial infection.

• Clinical and Experimental Pediatrics
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• v.48 no.9
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• pp.969-975
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• 2005

Purpose : We performed a study of clinical findings of Mycoplasma Pneumonia in children, to know differences between recent clinical manifestations of Mycoplasma pneumonia and previous studies. Methods : The subjects of this study were 393 children who were diagnosed as Mycoplasma pneumonia with high titers of Mycoplasma antibody(${\geq}1$ : 160) or fourfold rises of Mycoplasma antibody at Chung Ang University Hospital from January 1998 to December 2003. We practiced a retrospective study on the clinical manifestations of Mycoplasma pneumonia based on their medical records. Results : Male to female ratio was 1.06 to 1 and mean age was $4.32{\pm}2.94years$. The highest incidence was in the age of 2 to 3 years(18.6 percent). Most frequent months were October, and November in 2000, April in 2002, and October and, December in 2003. Twenty six point seven percent showed allergic diseases. Second degree relatives of 10.7 percent patients had allergic diseases. Forty three point three percent were admitted before this admission for pneumonia. Allergic tests were positive in 65.7 percent. Cough, and sputum were the most common symptoms and abdominal pain, and vomiting were the most frequent extrapulmonary symptoms. Atelectasis and pleural effusion were seen in 2.5 percent and 1.8 percent. Infiltrations were more common on the right side. Titers of each simultaneous test for cold agglutinin and mycoplasma antibody were not in proportion to each other (P=0.163). Conclusion : The onset age of mycoplasma pneumonia was found to be lower than it used to be. More patients had a past medical history or a family history of allergic disease, and more wheezing was heard and associated with recurrent pneumonia.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.539-544
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• 2005

Purpose : The aim of this study was to investigate the pathophysiologic role of serum E-selectin, vascular endothelial growth factor(VEGF)-induced cell adhesion mollecule in Kawasaki disease(KD) and to look for the evidence of direct relationship between the plasma levels of soluble E-selectin and the incidence of coronary artery lesion(CAL). Methods : Changes in plasma levels of sE-selectin(n=98) over time were measured by enzyme-linked immunosorbent assay(ELISA) in 23 patients with acute KD and 25 age-matched febrile children. Results : Compared with control values, the peak levels of plasma sE-selectin were significantly elevated($mean{\pm}S.E$. : $22.89{\pm}12.53ng/mL$ vs $10.65{\pm}3.42ng/mL$, P=0.01) in KD. 5 patients with CAL, plasma sE-selectin levels before treatment were higher than in 18 patients without CAL($mean{\pm}S.E$. : $39.43{\pm}15.08ng/mL$ and $19.00{\pm}8.32ng/mL$, respectively; P=0.01). Plasma sE-selectin declined rapidly in the majority of KD patients regardless of the presence of CAL. Plasma sE-selectin levels after treatment and convalesent period were similar in KD patients with and without CAL. The plasma levels sE-selectin were correlated with those of white blood cell count(r=0.299, P<0.05), CRP(r=0.430, P<0.05), serum albumin(r=-0.483, P<0.05), serum protein(r=-0.502, P<0.05) and hemoglobin(r=-0.372, P<0.05) not with those of ESR, platelet, or duration of fever. There were significant differences in the initial level of serum sE-selectin between KD with and without CAL($mean{\pm}S.E$. : $39.44{\pm}15.08ng/mL$ vs. $19.00{\pm}17.18ng/mL$) in multivariated linear tests. Conclusion : Plasma sE-selectin levels were significantly higher in KD than in other febrile illness. Higher plamsa levels of sE-selectin may have potential as a predictor of CAL in patients with KD.

• Clinical and Experimental Pediatrics
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• v.52 no.9
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• pp.1021-1028
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• 2009

Purpose:Medical therapy is the initial treatment for children with Graves disease to avoid complications of other treatments. However, optimal treatment for childhood Graves disease is controversial because most patients require relatively long periods of medical therapy and relapse is common after medication discontinuation. Therefore, this study aimed to search clinical or biochemical characteristics that could be used as remission predictors in Graves disease. Methods:We retrospectively studied children diagnosed with Graves disease, treated with anti-thyroid agents, and observed for at least 3 years. Patients were categorized into remission and non-remission groups, and the groups were compared to determine the variables that were predictive of achieving remission. Results:Sixty-four patients were enrolled, of which 37 (57.8%) achieved remission and 27 (42.2%) could not achieve remission until the last visit. Normalization of thyroid-stimulating hormone-binding inhibitory immunoglobulin (TBII) after treatment was faster in the remission group than in the non-remission group (remission group, $15.5{\pm}12.07$ vs. non-remission group, $41.69{\pm}35.70$ months). Thyrotropin-releasing hormone (TRH) stimulation tests were performed in 28 patients. Only 2 (8.3%) of 26 patients who showed normal or hyper-response in TRH stimulation test relapsed. Binary logistic regression analysis identified rapid achievement of TBII normalization after treatment as a significant predictor of remission. Six percent of patients achieved remission within 3 years and 55.8% achieved it within 6 years. Conclusion:Rapid achievement of TBII normalization can be a predictor of remission in childhood Graves disease. The TRH stimulation test can be a predictor of maintenance of remission.

• Magazine of the Korean Society of Agricultural Engineers
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• v.20 no.2
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• pp.4645-4687
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• 1978

This study was attempted to investigate the mechanical properties of concrete and crack control effects of reinforced concrete with steel and glass fiber. The experimental program includes tests on the properties of fresh concrete containing fibers, compressive strength, tensile strength, flexural strength, Young's modulus, Shrinkage and deformation of steel or glass fiber reinforced concrete. Also this study was carried out to investigate the effect of steel or glass fiber to retard the development in reinforced concrete subject to uniaxial tension and thus facilitate the use of steels of higher strength. The major conclusions that can be drawn from the studies are as follows: 1. The effect of the fibers in various mixes on fresh concrete confirmed that fibers do have a significant effect on the properties of fresh concrete, bringing much more stable and exhibiting a signiflcant reduction in surface bleeding, and that the cohesion is greatly improved and the internal resistance increases with fiber concentration. But the addition of an excess contents and length of fibers brings about the reduction of workability. 2. With the addition of steel fibers(1.5% Vol.) to concrete, the compressive strength as compared with plain concrete showed a very slight increase, but excess addition, over 1.5% Vol. of steel and glass fiber reduced its strength. 3. Splitting tensile strength of fiber reinforced concrete showed a significant increase tendency, as compared with plain concrete. In case of containing steel fiber (2.5%, 30mm), it showed that the maximum increase rate of 1.48 times as much rate, and in case of containing glass fiber (2.5%, 30mm), the increase rate of strength was 1.25 times as much rate. 4. Flexural strength of fiber reinforced concrete showed a significant tendency, as compared with plain concrete. Containing steel fiber (2.5%, 30mm) showed the maximum increase rate of 1.64 times as much rate and containing glass fiber (2.5%, 30mm) showed the increase rate of strength of 1.32 times as much rate, and in general, the 30mm length brougth the best results. 5. The strength ratio ($\sigma$b/$\sigma$c and $\sigma$t/$\sigma$c) increased, when steel fiber's average spacing was up to 3.05mm, but decreased when beyond 3.05mm, and it was confirmed that tensile or flexural strengths of steel fiber reinforced concrete are apparently governed by fiber's average spacing. 6. The compressive strain of fiber reinforced concrete showed a significant increasing tendency as the fiber was added, but Young's modulus. with the addition of steel and glass fibers, showed a slight decrease tendency. And according to the increase of flexural strength, a considerable increase was seen in toughness. 7. With the addition of fiber's the shrinkage of concrete was significantly decreased, in both case of adding steel fibers 12.5%, 30mm, and showed a significant decrease ratio, in average 30.4% and 36.7%, as compared with plain concrete. 8. With the increase of fiber volume fraction and length, the gained stress in reinforcing bar in concrete specimens increased in all crack widths, but at different rates, with the decrease of fiber diameter, the stress showed a considerable increasing tendency. And the duoform steel fibers showed the greatest improvement, as compared with the other types tested. 9. The influence of fiber dimensions in order of significanse on the machanical properties of concrete and the crack control of reinforced concrete was explained as follows: content, length, aspect ratio and dimeter.