• 대한의생명과학회지
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• 제18권4호
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• pp.428-434
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• 2012

Epilepsy is a chronic neurological disease showing a symptom of repeated seizures without any other physical disorders. Among the diagnostic examination for epilepsy, the electroencephalogram (EEG) has been known as an important test. This study aimed to investigate the EEG with photic stimulation in the pediatric epilepsy patients. They underwent digital sleep and waking EEGs or waking EEGs with photic stimulation. Epilepsy type, seizure history, and season of occurring seizure were analyzed. Epilepsy patients showed more response during the period of photic-on and eye close at the frequency of 10~20 Hz during the EEG activation procedure. Photoparoxysmal response (PPR) was shown in 206 patients out of total 1,551 epilepsy patients. PPR was appeared more frequently during summer and winter seasons, and especially in the patients who had a history of seizure. During the PPR, EEG pattern showed spike (77.18%), theta (9.71%), and spike + theta (13.11%). On the other hand, beta and theta waves were not significantly changed by photic stimulation. However, alpha wave was decreased and delta wave was increased by photic stimulation (P<0.05). These changes may be due to temporarily altered electrophysiological function of the epileptic patient's brain by the photic stimulation. There was no difference in the EEG pattern between the left and right side in the brain. In conclusion, condition of photic-on with closed eyes and frequency of 10~20 Hz during the procedure of EEG activation could be appropriate for obtaining a definite photoparoxysmal response in the electroencephalogram of the pediatric epilepsy patients.

• Journal of Photoscience
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• 제9권2호
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• pp.530-533
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• 2002

We present a case of The Miller Fisher Syndrome (MFS), showing a remission during a recently developed noninvasive therapy. Two weeks after an appearance of cough and fever, a 35 years old Japanese male developed diplopia, ataxia and numbness of his fingers and toes. He was diagnosed as MFS, and a fixed dose of prednisolone acetate (60mg/day) was administered for 3 months, but little improvement was observed. In addition to this administration, we tried 20 minutes of Photic Feedback (PFB) treatment daily for 40 days. The PFB system detects brain waves from the subject's forehead, and extracts alpha waves by the band-pass filter with a center frequency set at 10.0Hz. It also simultaneously modulates the augmentation of a red light-emitting diode, corresponding with the amplitudes of the extracted alpha waves. In this treatment, this adjusted photic stimulation was given to the subject's closed eyes, resulting in the effective alpha enhancement by photic driving response. The numbness increased during each of PFB treatment, but the symptoms started to improve gradually after 10 days. Other symptoms disappeared after 40 days. CD20 levels increased with this treatment. This case suggests that the PFB treatment may speed the natural remission of MFS. This treatment may be worth considering in patients who suffer polyneuropathy.

• Journal of Photoscience
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• 제9권2호
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• pp.472-474
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• 2002

Till date the phenomenon of maternal transfer of photic information was reported to regulate the fetal/neonatal growth, however its influence on neonatal immune system is still an enigma. In the present study, we observed an increase in maternal plasma melatonin level under short day length (SOL) condition with a consequent decrease in TLC and LC in their respective neonates. However, a significant decrease in maternal plasma melatonin level was noted under constant darkness (DD) with an increase in TLC and LC of their neonates. The blastogenic response (BGR) to Con A of splenocytes exhibited a significant increase in neonates of SDL females and a significant decrease in the neonates of DD females. Hence, it appears that the increase in maternal plasma melatonin under SOL condition transmitted information to decrease the immune status. Continuous exposure of females to darkness (DD) negatively regulated the maternal pineal gland activity thereby decreasing their plasma melatonin level. This information was transmitted for elevation of immune status in neonates, so that they exhibit better growth and sexual maturation. Therefore, we may suggest that the maternal photic information transmitted either prenatally through placenta or postnatally via the milk regulate the hormonal profile of Melatonin to regulate the immune status of neonates in order to influence their growth and sexual maturation.

• Journal of Photoscience
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• 제9권2호
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• pp.246-248
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• 2002

Light is a major environmental signal for entrainment of the circadian clock, but little is known about the phototransduction pathway triggered by light-activation of photoreceptive molecule(s) responsible for the phase shift of the clock in vertebrates. The chicken pineal gland and retina contain the autonomous circadian oscillators together with the photic entrainment pathway, and hence they provide useful experimental model for the clock system. We previously demonstrated the expression and light-dependent activation of rod-type transducin $\alpha$-subunit (Gtl$\alpha$) in the chicken pineal gland. It is unlikely, however, that the pineal Gt$_1$$\alpha$ plays a major role in the photic entrainment, because the light-induced phase shift is unaffected by bloking the signaling function of Gt$_1$$\alpha$. Here, we show the expression of G 11 $\alpha$, an $\alpha$-subunit of another heterotrimeric G-protein, in the chicken pineal gland and retina by cDNA cloning, Northern blot and Western blot analyses. GIl$\alpha$-immunoreactivity was colocalized with pinopsin in the chicken pineal cells and it was found predominantly at the outer segments of photoreceptor cells in the retinal sections, suggesting functional coupling of G11 $\alpha$ with opsins in the both the tissues. By coimmunoprecipitation experiments using the retina, we showed the light- and GTP-dependent interaction between rhodopsin and G11 $\alpha$. Upon ectopic expression of a Gq/ 11-coupled receptor in cultured pineal cells, pharmacological (non-photic) activation of endogenous G11 induced phase-dependent phase shifts of the melatonin rhythm in a manner very similar to the effect of light. These results suggested opsin-G11 pathway contributing to the photic entrainment of the circadian clock.

• Investigative Magnetic Resonance Imaging
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• 제1권1호
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• pp.114-118
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• 1997

목적: 기능적 MR 영상은 외부자극에 따라, 이에 상응하는 특정한 뇌피질 부위의 혈류량의 변화를 신호강도의 차이로 나타내는 방법이다. 시각피질에 대한 기능적 MR은 환자가 광자극을 응시함으로써 수행될 수 있는 것으로, 이의 수행에는 적절한 형태의 광자극원이 필수적이다. 이에 저자는 광자극원의 크기가 시각피질 활성화에 영향을 미칠 수 있는지 알아보기 위하여 본 연구를 하였다. 대상 및 방법: 정상적인 시력을 가진 자원자 5명을 대상으로 시각활성화 기능적 MR을 시행하였다. 광자극원은 $11{\times}8cm$ 크기의 기판에 적색 LED(light-emitting diodes) 39개를 박고 직류전원을 사용하도록 만들었다. 이를 크기에 따라 full field, half field 및 focal central field의 3가지로 구분하고 8Hz로 점멸하였다. EPI 기법으로 6회의 광자극 기간과 6회의 휴식기간을 번갈아 3차례 시행하여 총 36회의 검사를 하고, Z-score로 통계처리하였다. 이 때 얻은 활성화 영상을 같은 부위의 T1강조영상에 결합시켰다. 각 경우에서 시각피질에서 활성화된 pixel의 수를 full field, half field 및 focal central field에서 얻어진 pixel 수의 합으로 나누어 활성화지수를 구하였다. 이 활성화지수를 토대로 광원크기와의 관계를 분석하였다. 결과: Full field로 자극을 주었을 때 시각피질의 평균 신호강도의 증가는 약 9.6%였다. 4명에서 활성화지수는 full field, half field, focal central field의 순으로 감소하였으며, 나머지 1명에서는 half field 시의 값이 full field 시의 값보다 컸다. 광원크기에 따른 활성화지수의 범위는 full field 43-73%(평균 55%), half field 22-40%(평균 32%), focal central field 5-24%(평균 13%)였다. 결론: 기능적 MR영상을 이용하여 시각피질의 활성화를 용이하게 확인할 수 있었으며 광자극원의 크기에 따라 증가되는 시각피질 활성화를 입증할 수 있었다.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2003년도 학술대회지
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• pp.43-46
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• 2003

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 춘계학술대회
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• pp.21-24
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• 1993

The experimental results of visual stimulation with the tailored RF pulse are reported. Tailored RF pulse is used for the susceptibility effect imaging. Around 25% signal change of visual cortex area is detected during photic stimulation. Interestingly, with the tailored RF pulse, the signal intensity of visual cortex is deceased during photic stimulation. It is, however, increased with normal $T_2$ weighted imaging. The comparison between normal $T_2$ weighted imaging and the tailored RF pulse imaging are performed with 4T NMR system and the results with human volunteer are also presented.

• 생태와환경
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• 제37권4호통권109호
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• pp.406-410
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• 2004

2000년 두 댐 저수지와 유입 하천에서 월별 alkaline phosphatase activity (APA)을 측정하였다. 또한 2001년 여름 동안은 한 댐 저수지에서 APA의 수직변화와 관련된 요인들을 조사하였다. APA는 여름 동안 저수지 표층에서 상대적으로 높게 나타났으나 심층에서는 거의 변화가 없었다. 그러나 바닥층 바로 윗부분에서는 APA의 미미한 증가 관찰되었다. APA변화와 용존무기인 농도 변화와는 상관관계가 없었으며, 이 결과 조사 대상 저수지에서 APA는 인 이용성의 상태를 의미하지는 않는 것으로 추정되었다. 시료의 size-fractionation 분석 결과, 조사 대상 저수지들에서 APA는 $0.4{\mu}m$보다 큰 입자들에 흡착된 반면, 유입 하천에서는 용존형태로 존재하는 것으로 판단되었다. 저수지 유광층에서 엽록소-a의 농도와 APA간에 유의한 양의 상관성이 나타났다. 무광층에서 APA는 세균의 colony count와 양의 상관성을 나타냈으나 총 세균수와는 상관성이 없었다.

• 한국환경보건학회지
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• 제27권4호
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• pp.1-8
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• 2001

From August 2000 to August 2001, 9 variables of physicochemical factors and phytase activity were investigated at 4 sites in the River Yungpyung and the influences of Physicochemical factors to Phytase activity were analyzed. Phytase activities of Site 1, Site 2, Site 3, and Site 4 varied between N.D ∼566 nmol/ ι /hr, N.D \" 434 nmol/ ι /hr, N.D ∼557 nmol/ ι /hr, and N.D ∼723 nmol/ ι /hr, respectively. The activities of summer season were higher than those of other season. But the activities were not detected on the winter season. The phytase activity and temperature showed high correlation. The correlation coefficients of Site 1, Site 2, Site 3, and Site 4 were 0.82(p<0.01).0.92(p<0.01),0.87(p<0.01), and 0.88(p<0.01), respectively. The phytase activity and NOI₃/sup -/ ion showed negative relation(r=-0.59, p<0.05) at Site 1. And the phytase activity had relation with Zn/sup 2+/at Site 2(r=().57, p<0.05) and Site 3(r=0.7E, p<7.07).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.127-130
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• 2000

Classification of Electroencephalogram(EEG) makes one of key roles in the field of clinical diagnosis, such as detection for epilepsy. Spectrum analysis using the fourier transform(FT) uses the same window to signals, so classification rate decreases for nonstationary signals such as EEG's. In this paper, wavelet power spectrum method using wavelet transform which is excellent in detection of transient components of time-varying signals is applied to the classification of three types of Event Related Potential(EP) and compared with the result by fourier transform. In the experiments, two types of photic stimulation, which are caused by eye opening/closing and artificial light, are used to collect the data to be classified. After choosing a specific range of scales, scale-averaged wavelet spectrums extracted from the wavelet power spectrum is used to find features by Back-Propagation(13P) algorithm. As a result, wavelet analysis shows superiority to fourier transform for nonstationary EEG signal classification.