• Radiation Oncology Journal
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• v.18 no.2
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• pp.92-100
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• 2000

Purpose :This study was performed to determine the optimal treatment velum of Patients treating with radiation therapy for intracranial germ cell tumor. Materials and Methods : From 1993 to 1998, 19 patients with intracranial germ cell tumors treated by gamma knife radiosurgery were analyzed. The location of tumor was as follows; 9 cases on pineal region, 1 case on suprasellar region, and 9 cases of multiple lesion. 7 patients were pathologically verified; 5 cases of germ cell tumor and 2 cases of non germinomatous germ cell tumor. Tumor volume was ranged from 2.4 cm$^{3}$ to 74 cm$^{3}$. Irradiation dose was 10 Gy to 20 Gy with 50% isodose curve. Follow up period was 10 months to 54 months. Results : Recurrences were observed in 14 cases among 19 (74%) patients. Complete remission and partial remission were achieved in 2 (11%) and 10 (53%) respectively. No response was observed in 7 (36%). 2 cases were recurred within original tumor bed. 6 cases were recurred beyond but contiguous with tumor bed. Ventricular relapses separated from pretreatment tumor bed were 3. Spinal recurrences were 4. Among 8 recurred cases of which tumor volume is smaller than 20 cm$^{3}$, 2 were recurred within original tumor bed, 4 were recurred beyond but contiguous with tumor bed, and 1 spinal recurrence. Meanwhile, 6 cases of which tumor volume larger than 20 cm3, 1 case was recurred beyond but contiguous with tumorbed, 2 ventricular recurrences separated with original tumor bed, and 3 spinal recurrences. 5 cases which did not show any recurrence sign showed characteristics of single lesion, tumor volume smaller than 20 cm$^{3}$ and normal tumor marker. All of 4 cases of spinal recurrences happened in the case having ventricular invasion or lesion. Among 9 cases having multiple lesion, only 3 cases recurred within original tumor bed or around tumor bed, the other 6 cases recurred separated from pretreatment tumor bed. Conclusion : Gamma knife radiosurgery is not recommended for the treatment of intracranial germ cell tumor. It is because of small treatment volume and inadequate radiation dose that are characteristics of gamma knife radiosurgery. Tumor volume, ventricular invasion or ventricular lesion in multiple lesion are important factors to be considered for the wide field radiation therapy Tumor volume smaller than 20 cm$^{3}$, single lesion, no ventricular lesion or invasion, and normal tumor marker are ideal indications for small involved field radiation therapy. Prophylactic spinal irradiation seems to be necessary when there is ventricular lesion, ventricular invasion, and multiple lesions. When the tumor volume is larger than 20 cm$^{3}$, multiple lesions, abnormal tumor marker, and whole ventricular irradiation or partial brain irradiation would be possible and neoadjuvant chemotherapy would be most beneficial in these group.

• Journal of Life Science
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• v.13 no.3
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• pp.291-297
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• 2003

A human endogenous retroviral family (HERV-W) has recently been described that is related to multiple sclerosis-associated retrovirus (MSRV) sequences that have been identified in particles recovered from monocyte cultures from patients with multiple sclerosis. Two pol fragments (HWP-FB10 and HWP-FBl2) of HERV-W family were identified and analysed by the PCR approach with cDNA library of human fetal brain. They showed 89 percent nucleotide sequence similarity with that of the HERV-W (accession no. AF009668). Deletion/insertion or point mutation in the coding region of the pol fragments from human fetal brain resulted in amino acid frameshift that induced a mutated protein. Phylogenetic analysis of the HERV-W family from GenBank database indicates that the HWP-FB10 is very closely related to the AC000064 derived from human chromosome 7q21-q22. Further studies on the genetic relationship with neighbouring genes and functional role of these new HERV-W pol sequences are indicated.

• Progress in Medical Physics
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• v.5 no.2
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• pp.57-68
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• 1994

Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.316-321
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• 2017

The occurrence of subclavian steal syndrome is possible in patients with either severe stenosis or occlusion in the left proximal subclavian or brachiocephalic arteries. Limited and insufficient blood flow in the vessel with a lesion induces blood supply from the opposite side via any of the connected vessels, which is called a subclavian steal phenomenon. The duplex sonography is useful for detecting this phenomenon. Some patients who experience this phenomenon complain of vertebrobasilar insufficiency, such as headache or numbness and weakness in the arm, and so on. Subclavian steal syndrome means subclavian steal phenomenon accompanied by these symptoms. We present a patient with focal severe stenosis of the brachiocephalic artery, manifested as blood flow reversal in the vertebral, and a "to-and-fro" waveform pattern in the external carotid, internal carotid, and common carotid arteries.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.141-151
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• 2007

Parkinson's disease is one of the most frequent neurodegenerative diseases, which mainly affects the elderly. Parkinson's disease is often difficult to differentiate from atypical parkinson diorder such as progressive supranuclear palsy, multiple system atrophy, dementia with Lewy body, and corticobasal ganglionic degeneration, based on the clinical findings because of the similarity of phenotypes and lack of diagnostic markers. The accurate diagnosis of Parkinson's disease and atypical Parkinson disorders is not only important for deciding on treatment regimens and providing prognosis, but also it is critical for studies designed to investigate etiology and pathogenesis of parkinsonism and to develop new therapeutic strategies. Although degeneration of the nigrostriatal dopamine system results in marked loss of striatal dopamine content in most of the diseases causing parkinsonism, pathologic studies revealed different topographies of the neuronal cell loss in Parkisonism. Since the regional cerebral glucose metabolism is a marker of integrated local synaptic activity and as such is sensitive to both direct neuronal/synaptic damage and secondary functional disruption at synapses distant from the primary site of pathology, an assessment of the regional cerebral glucose metabolism with F-18 FDG PET is useful in the differential diagnosis of parkinsonism and evaluating the pathophysiology of parkisonism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1743-1750
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• 2003

DC motor requires a rotor speed sensor for accurate speed control. The speed sensors such as resolvers and encoders are used as a speed detector, but they increase cost and size of the motor and restrict the industrial drive applications. So in these days, many papers have reported in the sensorless operation of DC motor〔3­5〕. This paper presents a new sensorless strategy using neural networks〔6­8〕. Neural network has three layers which are input layer, hidden layer and output layer. The optimal neural network structure was tracked down by trial and error, and it was found that 4­16­1 neural network structure has given suitable results for the instantaneous rotor speed. Also, learning method is very important in neural network. Supervised learning methods〔8〕 are typically used to train the neural network for learning the input/output pattern presented. The back­propagation technique adjusts the neural network weights during training. The rotor speed is gained by weights and four inputs to the neural network. The experimental results were found satisfactory in both the independency on machine parameters and the insensitivity to the load condition.

• Industry Promotion Research
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• v.8 no.4
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• pp.187-200
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• 2023

The purpose of this paper is to correspond to four-elements in astrology theory, an intellectual from ancient times, that show personality temperament among MBTI, a representative personality type test in modern times, furthermore, by examining 16 personality type cards in tarot, a play culture and fortune telling culture in which the four-element theory is integrated in symbols, it is a comparative consideration that connects the characteristics of the character types contained in them to the 16 personality types of MBTI. The four preferred types of MBTI are Extravesion(E) and Introversion(I), Sensing(S) and Intuition(N), Thinking(T) and Feeling(F), Judgment(J) and Perception(P). Among them, Western four-elements were able to respond to Fire, Water, Air, and Earth in the order of NF(iNtuitive Feeling Type), SF(Sensory Feeling Type), NT(iNtuitive Thinking Type), and ST(Sensory Thinking Type). This is a result that can be derived by comparing individual personality theory and MBTI temperament theory among the symbols contained in ancient astrological theories. And the classification of boys, knights, queens, and kings in the four classes of person cards could be divided according to the MBTI attitude index. The boy showed an adaptive introvert using I and P, the knight showed an adaptive extrovert using E and P, the queen showed a decisive introvert using I and J, and the king showed an adaptive extrovert using E and J.

• Applied Microscopy
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• v.42 no.2
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• pp.77-86
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• 2012

The morphological and histologic differentiation of the central nervous system (CNS) in the wolf spider Arctosa kwangreungensis with respect to postembryonic development are studied using light and scanning electron microscopes. The organization of CNS which consisted of supraesophageal ganglion (SpG) and subesophageal ganglion (SbG) are established prior to the postembryo stage. The brain of first instar spiderling after a molt of the postembryo is also made up of supraesophageal ganglion and subesophageal ganglion. Although development of the optic nerve and optic lobe in SpG are not completed during the postembryoic stage, completion of whole neural system resemble to that of adult are established during the second instar stage. In particular, optic gangalion is developed from the undifferentiated cell clusters of the SpG, moreover four pairs of appendage ganglia and another pairs of abdominal ganglia are produced from the SbG. Nerve cells of the most developing stages are composed of typical monopolar neur1ons, and total three types of neurons can be identified through the histological and morphological basis of present study. These cell clusters are differentiated into neurons and grow dendritic fibers according to further development of the CNS.

• Korean Journal of Cognitive Science
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• v.27 no.2
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• pp.159-219
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• 2016

Mathematical ability is important for academic achievement and technological renovations in the STEM disciplines. This study concentrated on the relationship between neural basis of mathematical cognition and its mechanisms. These cognitive functions include domain specific abilities such as numerical skills and visuospatial abilities, as well as domain general abilities which include language, long term memory, and working memory capacity. Individuals can perform higher cognitive functions such as abstract thinking and reasoning based on these basic cognitive functions. The next topic covered in this study is about individual differences in mathematical abilities. Neural efficiency theory was incorporated in this study to view mathematical talent. According to the theory, a person with mathematical talent uses his or her brain more efficiently than the effortful endeavour of the average human being. Mathematically gifted students show different brain activities when compared to average students. Interhemispheric and intrahemispheric connectivities are enhanced in those students, particularly in the right brain along fronto-parietal longitudinal fasciculus. The third topic deals with growth and development in mathematical capacity. As individuals mature, practice mathematical skills, and gain knowledge, such changes are reflected in cortical activation, which include changes in the activation level, redistribution, and reorganization in the supporting cortex. Among these, reorganization can be related to neural plasticity. Neural plasticity was observed in professional mathematicians and children with mathematical learning disabilities. Last topic is about mathematical creativity viewed from Neural Darwinism. When the brain is faced with a novel problem, it needs to collect all of the necessary concepts(knowledge) from long term memory, make multitudes of connections, and test which ones have the highest probability in helping solve the unusual problem. Having followed the above brain modifying steps, once the brain finally finds the correct response to the novel problem, the final response comes as a form of inspiration. For a novice, the first step of acquisition of knowledge structure is the most important. However, as expertise increases, the latter two stages of making connections and selection become more important.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.25-31
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• 2007

Background: Cerebral protection is one of the most important procedures during aortic arch surgery. We can minimize neurological complications through short period of total circulatory arrest and resuming of brain perfusion. We evaluated 11 patients who underwent arch replacement using antegrade brain perfusion via right axillary artery. Material and Method: Between July 2004 and July 2006, 11 patients (male 9, female 2) underwent aortic arch replacement with antegrade brain perfusion via right axillary artery. Preoperative diagnosis was listed; 5 type A aortic dissections (5/11, 45.5%), 5 aortic aneurysms (5/11, 45,5%) and 1 type A IMH (intramural hematoma, 1/11, 9%). The mean age at the time of operation was $60.3{\pm}12.8$ years. For antegrade brain perfusion, we performed right axillary artery cannulation in all patients. Retrograde brain perfusion was used briefly during total circulatory arrest. Result: The mean total circulatory arrest time was $31.1{\pm}16.9$ minutes and the mean retrograde brain perfusion time was $21{\pm}17.8$ minutes. Mean antegrade brain perfusion time was $77.9{\pm}17.5\;(43{\sim}101)$ minutes. We had neither operative mortality nor permanent neurological complications. Conclusion: By means of antegrade brain perfusion via right axillary artery, that could lead to decrease circulatory arrest time and minimize damages to severely atheromatous arch vessels, we can expect to reduce neurological complications after aortic arch replacement. Further investigation with iarge patient populations will be required.