S C Lee

Korea Atomic Energy Research Institute (KAERI), Daiden, Daejeon, South Korea

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Publications (29)46.56 Total impact

  • G A Kim · T H Rim · S C Lee · S H Byeon · H J Koh · S S Kim · C S Lee
    [Show abstract] [Hide abstract] ABSTRACT: PurposeTo investigate factors associated with good response to intravitreal bevacizumab (IVB) in central serous chorioretinopathy (CSC) patients.Methods We retrospectively reviewed 42 eyes of CSC patients of symptom duration more than 3 months who received a single or multiple successive IVBs on an as-needed basis (0.05 ml, 1.25 mg). High responders (HRs) were defined as complete resolution of subretinal fluid (SRF) on spectral domain optical coherence tomography (SD-OCT). Moderate responders (MRs) were defined as SRF resolution of 50-99% of pretreatment volume and poor responders (PRs) as SRF resolution <50%. Clinical, SD-OCT, fluorescein, and indocyanine green angiography findings were analyzed to find factors associated with HR. Descriptive statistics for all demographic and clinical variables were calculated, and comparisons were made using Wilcoxon's matched-pairs signed-rank test, the Mann-Whitney U-test for means with continuous data, Pearson's χ(2) test, and Fisher's exact test for categorical data.ResultsThe mean number of IVB was 1.9. At postoperative 1 month, there were 10 (24%) HRs, 18 (43%) MRs, and 14 (33%) PRs. At the last follow-up (the mean 8.6 months), there were 25 HRs (60%), 9 MRs (21%), and 8 PRs (19%). Thicker subfoveal choroid (P=0.036), smaller lesion diameter (P=0.019), and better baseline best-corrected visual acuity (P=0.002) predicted HRs at postoperative 1 month. HR at the last follow-up was associated with classic pattern fluorescein angiography finding.Conclusions Suboptimal effects of IVB on persistent CSC suggest primary IVB on selective cases with better vision, smaller lesion, and thicker choroid at baseline.Eye advance online publication, 8 May 2015; doi:10.1038/eye.2015.58.
    No preview · Article · May 2015 · Eye (London, England)
  • No preview · Article · May 2012 · Retina
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    W K Song · S S Kim · J-H Yi · S H Byeon · H J Koh · S C Lee · O W Kwon
    [Show abstract] [Hide abstract] ABSTRACT: To evaluate the relationship of axial length (AXL), intraoperatively assessed posterior vitreous detachment (PVD) status, and surgical outcomes of diabetic vitrectomy. Retrospective, consecutive case series. Clinical records were reviewed for 115 eyes (50 males, 65 females) with more than a 6-month follow-up who underwent diabetic vitrectomy from a single surgeon. Thirty-three eyes had vitreous haemorrhage, 37 had tractional retinal detachment (TRD) threatening the macula, 43 had TRD involving the macula, and two had neovascular glaucoma. AXL was measured preoperatively by ultrasonography, and PVD status was classified intraoperatively: broad vitreo-retinal adhesion as no PVD, PVD at the macular area with attachment at the disc as incomplete PVD, and complete PVD. Forty-four eyes had no PVD, 23 had incomplete PVD, and 48 had complete PVD. A majority of the no PVD group had macula off TRD (97.7%), whereas vitreous haemorrhage (68.7%) predominated in the complete PVD group. Longer AXLs were noted in the complete PVD group compared with the no PVD and incomplete PVD groups (ANOVA in three groups P=0.0001). Univariate analysis showed that AXL had an influence on anatomical success (P=0.02). Multiple logistic regression analysis yielded that PVD status is a significant predictor of the final best corrected visual acuity (BCVA)>20/100, and BCVA>20/40 (P=0.01, P=0.02). Intraoperatively assessed PVD status is a prognostic factor for functional outcomes of diabetic vitrectomy. Shorter AXL was associated with lesser PVD. In eyes with a lack of PVD, careful timing and decision of surgery are mandatory.
    Full-text · Article · Jul 2010 · Eye (London, England)
  • H C Kim · YJ Cho · C W Ahn · K S Park · J C Kim · J S Nam · Y S Im · J E Lee · S C Lee · H K Lee
    [Show abstract] [Hide abstract] ABSTRACT: Low serum nerve growth factor (NGF) levels have been reported in patients with diabetic peripheral neuropathy (DPN), but the role of NGF in the development of neuropathy is unclear. Thus, we investigated the associations of serum NGF level and NGF receptor activity with the presence and severity of DPN. One hundred and thirty-six patients with Type 2 diabetes were included in this cross-sectional study. Serum NGF levels were measured by ELISA. Expressions of NGF receptors (TrkA and p75(NTR)) were measured by immunohistochemical staining. The presence and severity of DPN were assessed by neuropathy disability score (NDS) and by corneal nerve fibre length (cNFL) and nerve branch density (cNBD) using in vivo confocal microscopy. Patients with DPN had higher serum NGF levels (56-451 pg/ml) than patients without DPN (4-54 pg/ml). However, in DPN patients, serum NGF was negatively associated with neuropathy severity (mild 222 +/- 64 pg/ml; moderate 114 +/- 17 pg/ml; severe 89 +/- 20 pg/ml). This negative association was consistent in all severity indices (NDS, P < 0.001; cNFL, P < 0.001; cNBD P = 0.010) even after adjustment for age, sex, diabetes duration, insulin use, fasting glucose and glycated haemoglobin. Although NGF receptor activities had significantly (P < 0.05) negative associations with the presence and severity of neuropathy, these associations were not significant when adjusted for other factors. Serum NGF level was positively associated with the presence of DPN but negatively associated with neuropathy severity in DPN patients. The change in serum NGF might be a consequence of, rather than a contributor to, the early development of DPN.
    No preview · Article · Dec 2009 · Diabetic Medicine
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    J H Bae · S C Lee
    [Show abstract] [Hide abstract] ABSTRACT: Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
    Full-text · Article · Jul 2009 · Eye (London, England)
  • W K Song · S H Byeon · S S Kim · O W Kwon · S C Lee
    No preview · Article · Jul 2009 · The British journal of ophthalmology
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    W K Song · W I Yang · S C Lee
    [Show abstract] [Hide abstract] ABSTRACT: Eye is the official journal of the Royal College of Ophthalmologists. It aims to provide the practising ophthalmologist with information on the latest clinical and laboratory-based research.
    Full-text · Article · Aug 2008 · Eye (London, England)
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    J Lee · S-H Chung · S C Lee · H J Koh
    Full-text · Article · Jan 2007 · Eye
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    S C Lee · J H Song · E J Chung · O W Kwon
    Preview · Article · Aug 2004 · Eye
  • SG Kim · SC Lee · YS Scong · SW Kim · OW Kwon
    [Show abstract] [Hide abstract] ABSTRACT: The classification, size and activity of choroidal neovascularization (CNV) by optical coherence tomography (OCT) were compared with those obtained by fluorescein angiography (FA) and Inclocyanine green angiography (ICG). This study included 32 patients (32 eyes) diagnosed as having CNV. The etiology of CNV was found to be age-related macular degeneration (AMD) or non-AMD. Patients were studied retrospectively by FA, ICG, and OCT. Of the 13 eyes with AMD, the boundary of the lesion could not be defined using FA in 7 patients. Among the 7 poorly defined CNV cases by FA, the identification of the boundary was possible in one case by OCT. The mean diameter of the classic well-defined lesions was 3500 +/- 421 mum by FA, 2624 +/- 1044 mum by 1CG, and 1927 +/- 1272 mum by OCT. The size of the CNV by OCT was always smaller than by FA or ICG. Of the 19 eyes with Non-AMD, the boundary of the lesion could not be defined by FA in 5 patients. Among the 5 poorly defined cases by FA, the identification of the boundary was possible in 3 cases by OCT. The mean diameter of the well-defined CNV lesions was 2153 +/- 759 pin by FA, 1929 +/- 673 mum by ICG, and 1322 +/- 566 mum by OCT. Retinal thickness, which represents retinal edema, was found to be proportional to lesion size, although the relationship was not statistically significant. Regardless of CNV type, FA, ICG and OCT used in combination increase the specificity of diagnosis if their findings are compared.
    No preview · Article · Oct 2003 · Yonsei Medical Journal
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    Y.W. Lee · H.J. Ahn · C.H. Choi · J.W. Sa · S.C. Lee
    [Show abstract] [Hide abstract] ABSTRACT: The toroidal field (TF) magnet system of Korea superconducting tokamak advanced research (KSTAR) device consists of 16 superconducting coils enclosed in the steel cases. The TF magnet structure protects the winding pack from mechanical, electrical, and thermal loads, and also supports three pairs of poloidal field (PF) coils as well as four pairs of central solenoid (CS) coils. A three-dimensional finite element (FE) model including the winding pack, insulation and filler material has been developed using solid brick elements, and a hybrid model with beam-shell elements has been also built for the verification purposes. The structural reliability of the TF magnet system is investigated by performing various analyzes such as a global/local analysis, a detailed analysis, and a fatigue evaluation. The results reveal that the maximum stress intensities of the TF magnet structure are below the allowable stress limit and its fatigue life complies with the requirements of the design criteria, so it can safely withstand the reference scenario operations. In addition, the design loads obtained from analysis results can be used for the detailed structural design of other supplementary components.
    Full-text · Article · Sep 2003 · Fusion Engineering and Design
  • SR Choi · SC Lee · BS Kim · SY Yoon · HC Park · SW Kang · KH Choi · YS Kim · SK Ha · K Park · DS Han · HY Lee
    [Show abstract] [Hide abstract] ABSTRACT: The number of diabetic ESRD patients has increased and death rates of diabetic patients on hemodialysis (HD), peritoneal dialysis (PD) and renal transplantation (RT) have remained higher than the death rate of non-diabetic patients. An attempt was made to compare the clinical characteristics, patients' cumulative survival, and technical survival among the three groups retrospectively according to the mode of renal replacement therapy(RRT), and to analyze the risk factors associated with mortality. A total of 229 diabetic ESRD patients diagnosed between 1986 and 1995 at the Severance Hospital who began dialysis or who underwent a kidney transplant were included and their medical charts were reviewed. Hypertension was the most common co-morbid disease in all study groups. The prevalence of cardiovascular disease was the only co-morbid condition that was significantly different among the three groups, which was highest in the PD group (24.4%) and lowest in the RT group (8%). In the analysis of a patient's cumulative survival rate not adjusted for age and sex, the RT group had the highest survival rate, and the cumulative survival rate of the HD and PD group were similar. The 5-year survival rate of the patients treated with HD, PD and RT was 28.8%, 19.8%, and 72.0%, respectively. No differences were observed in the patient's cumulative survival rate between the HD and PD patients even when it was adjusted for age. When adjusted for age, sex and risk factors, the relative death rate of the RT group was significantly lower in male patients younger than 60 years of age. With the exception of male patients younger than 60 years of age, the PD group showed a slightly lower relative death rate although it was not significant. The multiple Cox regression analysis of patient survival showed that age, serum albumin, BUN, mean hospital days, the presence of cardiovascular disease at the initiation of RRT were associated with mortality. The analysis of the technique survival rate revealed a better result in the HD group compared to PD group, but a limitation in being able to investigate the AVF function disturbed the accuracy of the analysis of technical survival rate. In conclusion, the survival rate between the PD and HD patients was not different and the RT group had the best survival rate. Therefore, kidney transplantation in diabetic ESRD patients should be considered positively if no other contraindicated condition for RT exit.
    No preview · Article · Jun 2003 · Yonsei Medical Journal
  • Y.W. Lee · S.C. Lee · H.S. Kim · C.Y. Joung · C. Degueldre
    [Show abstract] [Hide abstract] ABSTRACT: Modification of thermo-mechanical properties of simulated (SiC) silicon carbide-, (ZrO2) zirconia- and (MgAl2O4) spinel-based inert matrix nuclear fuels after cyclic thermal shock was analyzed in terms of Vickers hardness (HV), fracture toughness (KIC) and thermal conductivity. Three different simulated specimens were used for the experiment; a solid solution of yttria-stabilized zirconia and ceria (composition: Er0.07Y0.10Ce0.15Zr0.68O1.915, 92.0% TD, specimen hereafter called Ce–ZrO2), a CeO2-dispersed Mg-spinel (composition: 15wt%CeO2–MgAl2O4, 93.7% TD, specimen hereafter called Ce-spinel) and a CeO2-dispersed silicon carbide (composition: 80.8 wt% SiC, 6.9 wt% Al2O3, 5.1 wt% Y2O3 and 5.0 wt% CeO2, specimen hereafter called Ce–SiC), CeO2 being surrogate materials for PuO2. Cyclic thermal shock experiment and thermal conductivity measurements were simultaneously carried out by heating disc-shaped specimens up to maximum temperature ranging from 1073 to 1673 K and then cooling down to 343 K with Ar gas during 20–25 min. The Vickers hardness of the three different thermally shocked specimens showed nearly constant values with increasing number of cycles, except for the specimen heated at 1673 K. The KIC values of the corresponding specimens increased with the increasing number of cyclic thermal shock at 1673 K. For Ce–ZrO2 heated at 1673 K, however, it decreases considerably due to the combined effects of formation of second phase and modification of the matrix composition thereby. The calculated thermal conductivity of Ce-spinel decreases as the number of cycles in thermal shock increases in the temperature range between 1073 and 1673 K, and Ce–SiC slightly decreased with the number of cycles in cyclic thermal shock and the variations in thermal conductivity are almost the same for the temperature increases of 1073 and 1373 K, whereas, in Ce–ZrO2, it remains nearly constant.
    No preview · Article · Jun 2003 · Journal of Nuclear Materials
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    H.J. Lee · S.C. Lee
    [Show abstract] [Hide abstract] ABSTRACT: This study was conducted to investigate the national methane emission from livestock enteric fermentation. For methane emission estimation, livestock were mainly categorized to cattle, swine, poultry, sheep, goats and horses, and cattle were further sub-categorized to calves, fattening cattle, breeding cows in Hanwoo and calves, fattening cattle and lactating cows in dairy cattle. Tier 2 methane emission factors were deduced based on the characteristics of animal performances, live weight, slaughter weight, daily weight gain, and feed digestibility in each category. Tier 2 emission factors of Hanwoo range from 39 to 49 kg/head/year and it is similar to that of Tier 1(47kg/head/year). Tier 2 emission factor of dairy cattle was 107 kg/head/year and it is slightly lower than that of Tier 1(118kg/head/year). Total methane emission from livestock enteric fermentation by Tier 2 method was estimated to be 126.8 tones in 2001. The methane emissions by Hanwoo, dairy cattle, swine, goats, horses and sheep were 61.70, 47.76, 13.08, 2.25, 0.17 and 0.01 tones, respectively. By the use of Tier 2 method instead of Tier 1, the accuracy and reliability of methane emission estimates from livestock enteric fermentation in Korea is considered to be improved.
    Preview · Article · Jan 2003
  • YW Lee · S. C. Lee · C. Y. Joung · H. S. Kim · H. L. Lee
    [Show abstract] [Hide abstract] ABSTRACT: The response of UO2 and (U-Ce)O2 nuclear fuel material to thermal stress was analyzed in terms of tine density and microstructural characteristics by measurement of the critical temperature difference in fracture ΔTC or thermal shock resistance R. An attempt was also made to correlate the decrease in ΔTC in UO2-5wt.-%CeO2 with the microstructural characteristics. The change in thermal shock resistance by the different material characteristics is complemented by cyclic thermal shock experiments in order to deduce additional properties such as durability of the materials.
    No preview · Article · Aug 2002 · Advanced Engineering Materials
  • ES Lee · HJ Koh · OW Kwon · SC Lee
    [Show abstract] [Hide abstract] ABSTRACT: Laser photocoagulation was performed around a detached retina in 4 patients who developed localized retina] detachment after successful scleral buckling. The range of retinal redetachment in all 4 patients was no larger than that of the initial retinal detachment and did not go over the vascular arcade. No evidence of vitreous traction or proliferative vitreoretinopathy was observed in these cases. Laser photocoagulation was performed in 3 lines of gray-white burn around the detached retina. Retinal attachment occurred between 4 and 14 days of laser treatment in all cases. No procedure related complications were seen. Laser photocoagulation may be an alternative procedure for the treatment of redetached retina with little and shallow detachment, before considering resurgery.
    No preview · Conference Paper · Aug 2002
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    [Show abstract] [Hide abstract] ABSTRACT: The toroidal field (TF) magnet system of Korea Superconducting Tokamak Advanced Research (KSTAR) device consists of 16 superconducting coils enclosed in steel cases. The TF cases are wedged along the inboard straight legs to sustain in-plane centering forces. The inter-coil structures contain adjustable shear keys and conical bolts to provide pre-loading in toroidal direction and to resist in-plane and out-of-plane forces, which are the most critical loads on the TF magnet system. For effective cooling of the TF case, a pad-type cooling channel has been designed to ensure structural and thermal stability. In order to investigate the structural integrity and to increase the structural reliability of the KSTAR magnet system, structural analyses have been conducted. From the analysis results, it has been found that the TF magnet structure can safely withstand the reference scenario operations.
    Full-text · Article · Apr 2002 · IEEE Transactions on Applied Superconductivity
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    [Show abstract] [Hide abstract] ABSTRACT: The central solenoid (CS) magnet system of the Korea Superconducting Tokamak Advanced Research (KSTAR) device consists of four pairs of segmented CS coils and a CS coil structure. The maximum repulsive force between CS coils is about 12 MN. The functions of the CS structure are to apply preload on the CS coils and to support the repulsive force between CS coils during operation. The designed axial compression of 15 MN at 4.5 K will be applied partly by assembling the preload structure at room temperature with preload of about 13.4 MN and partly by the thermal contraction difference between the CS coils and the structure during cool down. Additional preload will be given by minute adjustment of wedges. The structural analysis of the CS magnet system has been performed to verify the CS structure design reliability.
    Full-text · Article · Apr 2002 · IEEE Transactions on Applied Superconductivity
  • J S Yun · H S Kim · M K Lee · K W Oh · C G Jang · W K Park · YH Seong · S C Lee · S K Oh
    [Show abstract] [Hide abstract] ABSTRACT: A single high dose of apomorphine (10 mg x kg(-1)) produced not only contextual sensitization to and conditioning of climbing behavior, but also context-independent tolerance to hypothermia. MK-801 (0.15 and 0.3 mg x kg(-1)) inhibited contextual sensitization to and conditioning of climbing behavior. Development of tolerance to hypothermia was also inhibited by MK-801. Dopamine D1 antagonist, SCH23390 (0.5 mg x kg(-1)), but not D2 antagonist, sulpiride, inhibited sensitization to and conditioning of climbing behavior. D2 antagonist, sulpiride (50 mg x kg(-1)), but not D1 antagonist, SCH23390, inhibited development of tolerance to hypothermia. These results suggest that MK-801 inhibited contextual sensitization to climbing behavior and development of tolerance to hypothermia through glutamatergic modulation of dopaminergic functions at dopamine receptors.
    No preview · Article · Jan 2002 · Pharmacological Research
  • SC Lee · SH Kim · HJ Koh · OW Kwon
    [Show abstract] [Hide abstract] ABSTRACT: The present study investigated the effects of transforming growth factor (TGF)-beta on retinal pigment epithelial (RPE) transformation in a simplified model and also whether or not TGF-beta exhibits similar proliferation effects on transformed RPE cells that it has on primary RPE cells. Furthermore, we examined the cell proliferation effects of RPE-conditioned medium (CM). A vertical wound measuring 2 mm in diameter was made on primary RPE monolayers. The expression of a smooth muscle actin (SMA) by the cells located at the wound edges was observed using a confocal microscope under immunofluorescent staining. Cell proliferation was measured by incorporating 3H-thymidine into DNA. The presence of alpha -SMA was observed in the cells within the wound after treatment with TGF-beta2, while negative expression was observed in control cells. TGF-betas inhibited the proliferation of the primary cultures of RPE cells in a dose-dependent manner, but the spindle-shaped late-passaged RPE cells were not inhibited by these growth factors. The medium conditioned by RPE cells stimulated the proliferation of subconjunctival fibroblasts and inhibited the proliferation of primary RPE cells, in a manner similar to TGF-beta. These findings demonstrate that TGF-beta -stimulated RPE cells may evoke proliferative vitreoretinopathy through mesenchymal transformation and cell proliferation.
    No preview · Article · Jun 2001 · Yonsei Medical Journal

Publication Stats

234 Citations
46.56 Total Impact Points

Institutions

  • 2001-2003
    • Korea Atomic Energy Research Institute (KAERI)
      Daiden, Daejeon, South Korea
    • Korea Institute of Energy Research
      Sŏul, Seoul, South Korea
  • 2001-2002
    • Yonsei University
      • Department of Ophthalmology
      Sŏul, Seoul, South Korea