• Macromolecular Research
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• v.11 no.5
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• pp.334-340
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• 2003

In order to fabricate new sustained delivery device of nerve growth factor (NGF), we developed NGF-loaded biodegradable poly(L-lactide-co-glycolide) (PLGA, the mole ratio of lactide to glycolide 75:25, molecular weight: 83,000 and 43,000 g/mole, respectively) film by novel and simple sandwich solvent casting method for the possibility of the application of neural tissue engineering. PLGA was copolymerized by direct condensation reaction and the molecular weight was controlled by reaction time. Released behavior of NGF from NGF-loaded films was characterized by enzyme linked immunosorbent assay (ELISA) and degradation characteristics were observed by scanning electron microscopy (SEM) and gel permeation chromatography (GPC). The bioactivity of released NGF was identified using a rat pheochromocytoma (PC-12) cell based bioassay. The release of NGF from the NGF-loaded PLGA films was prolonged over 35 days with zero-order rate of 0.5-0.8 ng NGF/day without initial burst and could be controlled by the variations of molecular weight and NGF loading amount. After 7 days NGF released in phosphate buffered saline and PC-12 cell cultured on the NGF-loaded PLGA film for 3 days. The released NGF stimulated neurite sprouting in cultured PC-12 cells, that is to say, the remained NGF in the NGF/PLGA film at 37 $^{\circ}C$ for 7 days was still bioactive. This study suggested that NGF-loaded PLGA sandwich film is released the desired period in delivery system and useful neuronal growth culture as nerve contact guidance tube for the application of neural tissue engineering.

• Journal of the Korean Society of Systems Engineering
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• v.18 no.2
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• pp.94-107
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• 2022

Accidents prevention and mitigation is the highest priority of nuclear power plant (NPP) operation, particularly in the aftermath of the Fukushima Daiichi accident, which has reignited public anxieties and skepticism regarding nuclear energy usage. To deal with accident scenarios more effectively, operators must have ample and precise information about key safety parameters as well as their future trajectories. This work investigates the potential of machine learning in forecasting NPP response in real-time to provide an additional validation method and help reduce human error, especially in accident situations where operators are under a lot of stress. First, a base-case SGTR simulation is carried out by the best-estimate code RELAP5/MOD3.4 to confirm the validity of the model against results reported in the APR1400 Design Control Document (DCD). Then, uncertainty quantification is performed by coupling RELAP5/MOD3.4 and the statistical tool DAKOTA to generate a large enough dataset for the construction and training of neural-based machine learning (ML) models, namely LSTM, GRU, and hybrid CNN-LSTM. Finally, the accuracy and reliability of these models in forecasting system response are tested by their performance on fresh data. To facilitate and oversee the process of developing the ML models, a Systems Engineering (SE) methodology is used to ensure that the work is consistently in line with the originating mission statement and that the findings obtained at each subsequent phase are valid.

• Journal of Korean Medicine Rehabilitation
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• v.18 no.3
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• pp.19-39
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• 2008

Objectives : It has been reported that CG was effective in decreasing injury to neural tissues. To investigate neural responses in the injured spinal cord, an extract of CG was examined to determine its effect on neural responses in the injured spinal cords of rats. Methods : After CG treatment was applied to the spinal cord of rats given a contusion injury, the re-growth responses of injured neural tissues and corticospinal tract axons was observed by measuring the number of GAP-43, Cdc2, and phospho-Erk1/2 proteins, CST axons, GFAP-stained astrocytes, and Glial scarring in the injured spinal cord. Results : Levels of GAP-43, Cdc2, and phospho-Erk1/2 proteins were found to have increased in the injured spinal cord region. The number of GFAP-stained astrocytes also increased within and around the injury cavity. Glial scarring, which was identified by CSPG immunofluorescence staining, was reduced by CG treatment. Anterograde tracing by Dil dye showed that the elongation of the CST axons in the dorso-medial white matter area was almost completely prevented at the injury site. Collateral sprouting was observed in the spinal cord rostrally close to the injury site, and CG treatment further increased axonal arborization in the corresponding region. In vivo migration of CST axons and astrocytes using an implanted polymer tube system showed more of an increase in enhanced migration of axons and astrocytes in CG-treated group compared to the injury control group. Conclusions : These results suggest that CG activated neural responses - including astrocyte migration - and promotes axonal regenerative activity in the injured spinal cord area.

• BMB Reports
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• v.44 no.2
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• pp.113-117
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• 2011

Previous studies suggest that EphA7 plays a critical role in neural tube closure or cortical progenitor apoptosis. In this report, enhancer trap assay was used to modify various EphA7 BAC clones and screen a large genomic region spanning 570 kb downstream of the EphA7 gene. We found that the dorsal midline-specific EphA7 enhancer resides on the 457D20 EphA7 BAC clone and is localized to a 35 kb genomic region in between +345.7 kb to +379.8 kb downstream of the EphA7 transcription start site. Identification of the EphA7 BAC clone containing a long-range dorsal midline enhancer may constitute a useful tool for investigating the biological functions of EphA7 in vivo.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.321-326
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• 2020

There has been confusion in the classification of terminal myelocystocele (TMCC) due to its diverse morphology and vague pathoembryogenesis. TMCC could be summarized as having the essential features of an elongated caudal spinal cord extruding out of the dorsal extraspinal space that fuses with the subcutaneous fat, which is in the shape of a trumpet-shaped cerebrospinal fluid-filled cyst. The extraspinal portion of the extruded spinal cord is nonfunctional. The morphological features suggest that TMCC is formed during secondary neurulation, specifically the failure of the degeneration of the secondary neural tube near the time of the terminal balloon. This review discusses the definition, as well as the clinical and surgical features, of TMCC with special emphasis on its pathoembryogenesis.

• Journal of Korean Neurosurgical Society
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• v.63 no.3
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• pp.272-278
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• 2020

Compared to any other decade, the last two decades have been the most dynamic period in terms of advances in the knowledge on spinal dysraphism. Among the several factors of rapid advancement, such as embryology during secondary neurulation and intraoperative neurophysiological monitoring, there is no doubt that Professor Dachling Pang stood high amidst the period. I review here the last two decades from my personal point of view on what has been achieved in the field of spinal dysraphism, focusing on occult tethered cord syndrome, lumbosacral lipomatous malformation, terminal myelocystocele, retained medullary cord, limited dorsal myeloschisis and junctional neural tube defect. There are still many issues to revise, add and extend. Profound knowledge of basic science is critical, as well as refined clinical analysis. I expect that young scholars who follow the footsteps of precedent giants will shed bright light on this topic in the future.

• Journal of Genetic Medicine
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• v.5 no.1
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• pp.7-14
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• 2008

Twenty years have passed since a prenatal screening for Down syndrome and neural tube defect was applied to obstetric field. The Quad test (AFP, hCG, uE3, Inhibin-A) of the second trimester and the combination test (PAPP-A, hCG, NT) of the first trimester became popular now. The recent trend of prenatal screening is to combine these two screening tests together in order to increase a detection rate of Down syndrome. Three types of screening methods are introduced as follows; integrated test, sequential test and contingent test. In addition to combination of each test, an incorporation of characteristic ultrasound findings of Down syndrome is suggested for its risk calculation. The absence of fetal nasal bone would be a very useful marker especially in the first trimester screening test. According to a change of way calculating risk of Down syndrome, obstetrician's role will be more increased not by passive participation, but by active participation using ultrasound in risk calculation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.7
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• pp.306-312
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• 2006

Support Vector Machine(SVM), of which the foundations have been developed by Vapnik (1995), is gaining popularity thanks to many attractive features and promising empirical performance. In this paper, we propose a new short-term load forecasting technique based on SVM. We discuss the input vector selection of SVM for load forecasting and analyze the prediction performance for various SVM parameters such as kernel function, cost coefficient C, and $\varepsilon$ (the width of 8 $\varepsilon-tube$). The computer simulation shows that the prediction performance of the proposed method is superior to that of the conventional neural networks.

• Perinatology
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• v.29 no.4
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• pp.185-188
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• 2018

Jarcho-Levin syndrome is a congenital disorder characterized by several vertebral and costal anomalies. Other abnormalities have also been described, including neural tube defects, Arnold-Chiari malformation, renal/urinary tract abnormalities, hydrocephalus, hydroureteronephrosis, and meningomyelocele. We describe a spondylocostal dysplasia form of Jarcho-Levin syndrome that was prenatally diagnosed at 11 weeks of gestation and surviving. Although the patient had sporadic-type Jarcho-Levin syndrome, with normal karyotype and no family history of disease, the assessment of inheritance patterns and genetic counseling for the parents was important to inform them about the potential risks.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.173-175
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• 2019

Animated images formats such as WebP are highly portable graphics formats that are being used everywhere on the Internet. Despite their small sizes and duration, WebP image previews the video without watching the entire content with minimum bandwidth. This paper proposed a novel method to generate personalized WebP images in the client side using its computation resources. The proposed system automatically extracts the WebP image from climax point using music analysis. Based on user interest, the system predicts the genre using Convolutional Neural Network (CNN). The proposed method can easily integrate with streaming platforms such as YouTube, Netflix, Hulu, and others.