• Korean journal of communication and information
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• v.81
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• pp.299-328
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• 2017

This study investigated news comprehension via the social media by comparing the reading of a news story on the news paper. A news story on the social media was suggested to present information in a conversational form, which differs from a traditional reporting style. To compare the different forms of news information presentation, two conditions were created: in a control condition, a news story was written in a traditional reporting form. In the experimental condition, the same news story was constructed in a conversational form. Participants were assigned randomly in one of two conditions. They read the news story and afterwards, they were asked to recall firstly, the core idea of the news story, secondly the whole news story, and finally to answer to the 10 questions that assessed how well they learned from the news story. Participants' responses were content-analyzed and produced six variables, the extent to recall the core idea, the extent to recall the whole story, the extent to recall wrong information, the extent to recall additional information, the extent to recall causally related contents in general, and finally the extent to recall causally related contents in story-specific. Analyses on the six variables revealed that the group in the news paper condition recalled more core idea, the whole story, and additional information than the group in the social media. But the news paper condition recalled less of wrong information than the group in the social media condition. Additionally, the news paper condition learned more than the group in the social media. Regarding the recall of causally related contents, the general causal relationships were recalled more in the group in the social media condition but the story specific causal relationships were recalled more in the group in the news paper condition. The findings seemingly indicated that a traditional news reporting contributes to news story comprehension more than the conversational form. Authors however added discussions and advised that the findings needed to be read under caution.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.4
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• pp.173-177
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• 2019

Objective: We investigated the clinical characteristics of men with testosterone replacement therapy (TRT)-induced hypogonadism and its effect on assisted reproductive technology (ART) in infertile couples. Methods: This study examined the records of 20 consecutive male patients diagnosed with azoospermia or severe oligozoospermia (< 5 × 10⁶/mL) who visited a single infertility center from January 2008 to July 2018. All patients were treated at a primary clinic for erectile dysfunction or androgen deficiency symptoms combined with low serum testosterone. All men received a phosphodiesterase 5 inhibitor and TRT with testosterone undecanoate (Nebido^®) or testosterone enanthate (Jenasteron^®). Patients older than 50 years or with a chronic medical disease such as diabetes were excluded. Results: The mean age of patients was 37 years and the mean duration of infertility was 16.3 ± 11.6 months. At the initial presentation, eight patients had azoospermia, nine had cryptozoospermia, and three had severe oligozoospermia. Serum follicle-stimulating hormone levels were below 1.0 mIU/mL in most patients. Three ongoing ART programs with female factor infertility were cancelled due to male spermatogenic dysfunction; two of these men had normal semen parameters in the previous cycle. After withholding TRT, serum hormone levels and sperm concentrations returned to normal range after a median duration of 8 months. Conclusion: TRT with high-dose testosterone can cause spermatogenic dysfunction due to suppression of the hypothalamic-pituitary-testicular axis, with adverse effects on infertility treatment programs. TRT is therefore contraindicated for infertile couples attempting to conceive, and the patient's desire for fertility must be considered before initiation of TRT in a hypogonadal man.

• Journal of The Korean Society of Clinical Toxicology
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• v.8 no.1
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• pp.24-29
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• 2010

Purpose: Neonicotinoid insecticides are widely used as they have been proven by experimental studies to have low toxicity to mammals, including humans. As the use of neonicotioids increases, the number of patients with neonicotinoid poisoning has also increased. We conducted a study to investigate the clinical manifestations of neonicotinid poisoning. Methods: We retrospectively analyzed the patients who ingested neonicotinids and who visited the emergency department located in Korea from March 2002 to February 2010. We reviewed the patients' age, gender, the amount of exposure, the elapsed time to presentation, the treatment and the outcome. According to the poisoning severity score, we divided the patients with a Poisoning severity score (PSS) of 0 or 1 into the mild/moderate toxicity group and the patients with a PSS of 2 or 3 into the severe/fatal toxicity group. Results: A total of 24 patients were analyzed. The most common clinical manifestations of neonicotinoid insecticide toxicity were gastrointestinal symptoms (66.7%) such as nausea, vomiting and abdominal pain and the others are respiratory symptoms (16.7%), cardiovascular symptoms (12.5%), metabolic imbalance (12.5%), renal dysfunction (8.3%), CNS symptoms (8.3%), and asymptomatic (29.2%). Twenty patients (83.3%) showed mild/moderate toxicity and 4 patients (16.7%) showed fatal conditions such as shock and mutiorgan failure. The mortality rate was 4.2%. In these fatal cases, the patients developed respiratory failure, hypotension, altered mentality and renal failure at the acute stage and they deteriorated to a more serious condition. This severe toxicity was caused by decreased renal excretion of neonicotinid metabolite, and this was improved after hemodialysis. Conclusion: Most patients with neonicotinoid poisoning and who showed mild toxicity usually improved after symptomatic treatment. However, some patients showed significant toxicity with respiratory failure and renal function deterioration, and intensive care needed, including mechanical ventilation and hemodialysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.92-92
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• 2014

Recently, many state-of-art spectroscopy techniques are used to unravel the mysteries of condensed matters. And numerous heterostructures have provided a new avenue to search for new emergent phenomena. Especially, near the interface, various forms of symmetry-breaking can appear, which induces many novel phenomena. Although these intriguing phenomena can be emerged at the interface, by using conventional measurement techniques, the experimental investigations have been limited due to the buried nature of interface. One of the ways to overcome this limitation is in situ investigation of the layer-by-layer evolution of the electronic structure with increasing of the thickness. Namely, with very thin layer, we can measure the electronic structure strongly affected by the interface effect, but with thick layer, the bulk property becomes strong. Angle-resolved photoemission spectroscopy (ARPES) is powerful tool to directly obtain electronic structure, and it is very surface sensitive. Thus, the layer-by-layer evolution of the electronic structure in oxide heterostructure can be investigated by using in situ ARPES. LaNiO3 (LNO) heterostructures have recently attracted much attention due to theoretical predictions for many intriguing quantum phenomena. The theories suggest that, by tuning external parameters such as misfit strain and dimensionality in LNO heterostructure, the latent orders, which is absent in bulk, including charge disproportionation, spin-density-wave order and Mott insulator, could be emerged in LNO heterostructure. Here, we performed in situ ARPES studies on LNO films with varying the misfit strain and thickness. (1) By using LaAlO3 (-1.3%), NdGaO3 (+0.3%), and SrTiO3 (+1.7%) substrates, we could obtain LNO films under compressive strain, nearly strain-free, and tensile strain, respectively. As strain state changes from compressive to tensile, the Ni eg bands are rearranged and cross the Fermi level, which induces a change of Fermi surface (FS) topology. Additionally, two different FS superstructures are observed depending on strain states, which are attributed to signatures of latent charge and spin orderings in LNO films. (2) We also deposited LNO ultrathin films under tensile strain with thickness between 1 and 10 unit-cells. We found that the Fermi surface nesting effect becomes strong in two-dimensions and significantly enhances spin-density-wave order. The further details are discussed more in presentation. This work was collaborated with Hyang Keun Yoo, Seung Ill Hyun, Eli Rotenberg, Ji Hoon Shim, Young Jun Chang and Hyeong-Do Kim.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.982-986
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• 2007

Purpose : Intravenous immunoglobulin (IVIG) is effective for the treatment of idiopathic thrombocytopenic purpura (ITP) in children. Recently, several reports have been published that show its impact on the absolute neutrophil count. The present study was performed to confirm these findings. Methods : Data on 26 ITP patients were analyzed. Patients with febrile illness or increased C-reactive protein levels at presentation, which would influence the neutrophil counts, were excluded to determine the sole impact of IVIG. In addition, patients who received steroid treatment were also excluded. Results : Sixteen boys and ten girls were analyzed. For patients who received an IVIG dose of 0.4 g/kg/day (n=17), the absolute neutrophil count (ANC) measured next day was significantly decreased. For patients who received an IVIG dose of 1 g/kg/day (n=9), the ANC measured the next day was also significantly decreased. However, the decrease was more profound in the high-dose group compared to the low-dose group. Among six cases with profoundly decreased ANC greater than $1,000/mm^3$, four patients (67%) received IVIG at a dose of 1 g/kg/day. All four cases with increased ANC were treated with IVIG dose of 0.4 g/kg/day, and three cases (75%) among them had a febrile reaction during IVIG administration. None of the cases with decreased ANC had a febrile reaction. No cases had infectious complications reported. Conclusion : IVIG treatment for ITP patients appears to suppress the ANC. This decrease of ANC was more pronounced when a higher dose of IVIG was used. Some cases with increased ANC counts after IVIG use were found only in low-dose IVIG group, and was associated with febrile reactions during IVIG use.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.149-157
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• 2018

One of the purposes of radiation protection is to minimize stochastic effects. PCXMC 2.0 is a Monte Carlo Simulation based program and makes it possible to predict effective dose and the probability of cancer development through entrance surface dose. Therefore, it is especially important to measure entrance surface dose through dosimeter. The purpose of this study is to measure entrance surface dose through semiconductor dosimeter, general dosimeter, glass dosimeter, and to compare and analyze the effective dose and probability of disease of critical organs. As an experimental method, the entrance surface dose of skull, chest, abdomen was measured per dosimeter and the effective dose and the probability of cancer development of critical organs per area was evaluated by PCXMC 2.0. As a result, the entrance surface dose per area was different in the order of a general dosimeter, a semiconductor dosimeter, and a glass dosimeter even under the same condition. Base on this analysis, the effective dose and probability of developing cancer of critical organs were also different in the order of a general dosimeter, a semiconductor dosimeter, and a glass dosimeter. In conclusion, it was found that the effective dose and the risk of diseases differ according to the dosimeter used, even under the same conditions, and through this study it was found that it is important to present an accurate entrance surface dose model according to each dosimeter.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1999.04a
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• pp.5-5
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• 1999

The Principal deficiency of the existing notion about the sintering-mixtures consists in the fact that almost no attention is focused on the Phenomenon of alloy formation during sintering, its connection with dimensional changes of powder bodies, and no correct ideas on the driving force for the sintering process in the stage of establishing chemical equilibrium in a system are available as well. Another disadvantage of the classical sintering theory is an erroneous conception on the dissolution mechanism of solid in liquid. The two-particle model widely used in the literature to describe the sintering phenomenon in solid state disregards the nature of the neighbouring surrounding particles, the presence of pores between them, and the rise of so called arch effect. In this presentation, new basic scientific principles of the driving forces for the sintering process of a two-component powder body, of a diffusion mechanism of the interaction between solid and liquid phases, of stresses and deformation arising in the diffusion zone have been developed. The major driving force for sintering the mixture from components capable of forming solid solutions and intermetallic compounds is attributed to the alloy formation rather than the reduction of the free surface area until the chemical equilibrium is achieved in a system. The lecture considers a multiparticle model of the mixed powder-body and the nature of its volume changes during solid-state and liquid-phase sintering. It explains the discovered S-and V-type concentration dependencies of the change in the compact volume during solid-state sintering. It is supposed in the literature that the dissolution of solid in liquid is realised due to the removal of atoms from the surface of the solid phase into the melt and then their diffusicn transfer from the solid-liquid interface into the bulk of liquid. It has been shown in our experimental studies that the mechanism of the interaction between two components, one of them being liquid, consist in diffusion of the solvent atoms from the liquid into the solid phase until the concentration of solid solutions or an intermetallic compound in the surface layer enables them to pass into the liquid by means of melting. The lecture discusses peculimities of liquid phase formation in systems with intermediate compounds and the role of the liquid phase in bringing about the exothermic effect. At the frist stage of liquid phase sintering the diffusion of atoms from the melt into the solid causes the powder body to grow. At the second stage the diminution of particles in size as a result of their dissolution in the liquid draws their centres closer to each other and makes the compact to shrink Analytical equations were derived to describe quantitatively the porosity and volume changes of compacts as a result of alloy formation during liquid phase sinteIing. Selection criteria for an additive, its concentration and the temperature regime of sintering to control the density the structure of sintered alloys are given.

• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.757-760
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• 2007

Purpose : Febrile convulsions (FC) were considered to be a benign seizure syndrome that is distinct from epilepsy. But it is thought that children with complex features i.e., partial or prolonged seizures or multiple episodes of FC would bear a higher risk of developing unprovoked seizures. The aim of this study is to look into the relative significance of each criteria that define complex febrile convulsions (CFC) as a predictor of subsequent epilepsy. Methods : All children were retrospectively identified for a febrile seizure through pediatric departments of the Konyang University Hospital. Information was collected from medical records and interviews with parents. Patients with abnormal neurological examinations at presentation were excluded. Results : This study was performed from March 2000 to December 2003. Sixty-three out of 314 children (20.0%) with febrile convulsion fulfilled the criteria for CFC and forty-four children of them have been followed for 12 months or more. Ten of these (23.2%) had unprovoked seizures for 14-62 months (median $34.2{\pm}11.6$ months). The patients with partial FC showed a trend toward a higher risk (57.1%) of developing epilepsy than the patients with multiple or prolonged febrile convulsions (26.7%, 24.1% respectively). Conclusion : We found that the partial feature of febrile convulsion is associated with subsequent epilepsy.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.8.1-8.14
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• 2018

We previously demonstrated that the direct transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) into the dentate gyrus ameliorated the neurological symptoms of Niemann-Pick type C1 (NPC1)-mutant mice. However, the clinical presentation of NPC1-mutant mice was not fully understood with a molecular mechanism. Here, we found 14,15-epoxyeicosatrienoic acid (14,15-EET), a cytochrome P450 (CYP) metabolite, from hUCB-MSCs and the cerebella of NPC1-mutant mice and investigated the functional consequence of this metabolite. Our screening of the CYP2J family indicated a dysregulation in the CYP system in a cerebellar-specific manner. Moreover, in Purkinje cells, CYP2J6 showed an elevated expression level compared to that of astrocytes, granule cells, and microglia. In this regard, we found that one CYP metabolite, 14,15-EET, acts as a key mediator in ameliorating cholesterol accumulation. In confirming this hypothesis, 14,15-EET treatment reduced the accumulation of cholesterol in human NPC1 patient-derived fibroblasts in vitro by suppressing cholesterol synthesis and ameliorating the impaired autophagic flux. We show that the reduced activity within the CYP system in the cerebellum could cause the neurological symptoms of NPC1 patients, as 14,15-EET treatment significantly rescued cholesterol accumulation and impaired autophagy. We also provide evidence that the intranasal administration of hUCB-MSCs is a highly promising alternative to traumatic surgical transplantation for NPC1 patients.

• Journal of Korean Elementary Science Education
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• v.40 no.3
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• pp.311-325
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• 2021

Modern society demands a new science teacher image. Compared to other school ages, elementary school students are the time when the teacher's influence plays a large role and is the time when they first encounter science subjects. The role of science teachers is very important as the starting point for the initial image of science learning and attitudes toward science by elementary science teachers. Therefore, it is very important to correctly establish an image of an elementary science teacher. The purpose of this study is to analyze the images of science teachers that elementary school students prefer and avoid according to their class situation. To this end, 534 elementary school students were divided into five classes: class type, class material presentation method, subject instruction method, subject content explanation method, and class atmosphere, and the image of science teacher who prefers and avoids is described in an open format. Concepts presented by elementary school students were analyzed using Semantic network analysis. The conclusions of this study are as follows. First, the image of a science teacher preferred or avoided by elementary school students was determined according to how the science teacher did the class. Second, elementary school students prefer activity-oriented classes such as experimental classes, and there is a need for classes to be conducted in this manner. Lastly, small changes and efforts of teachers in teaching methods are needed so that changes to science classes preferred by elementary school students can be achieved.