고양이 소뇌 치상핵 자극에 따른 전경골근의 근전도 변화

성재훈,김문찬,강준기,최창락 대한신경외과학회 1994 Journal of Korean neurosurgical society Vol.23 No.7

Through the use of stereotactic neurosurgical operation, some authors have employed chronic electrical stimulation of the dentate nucleus reduce spasticity and each trial on spastic patients has show marked clinical improvement. We investigated the eletrophysiological changes of cats after stereotactic electrical stimulation of the dentate nucleus to elucidate the possibility of clinical application and to evaluate the clinical results The M-wave is an initial response and the F-wave is a late response in the electromyography of a muscle, which is stimulated by its original controlling nerve itself. There is evidence that the sue of the F-wave is dependent on motor neuron excitability and its amplitude is increased significantly at spastic condition. If such a relationship exists, procedures which are cam& out to relieve spasticity might be exerted to change the F-wave sue and thus it might be possible to use the F-wave as an objective monitor during electrical stimulation of the dentate nucleus. We investigated this possibility in experiments on 10 cats weighing betHieen 27kg and 4.4kg. We studied the change% of M and F waves, recorded in EMG, after stereotactic stimulation to cerebellar dentate nucleus in cats. The results were as follows 1) The change of mean value of M-wave amplitude was not significant(contro1 group, 3591 ± 1029μV stimulation group, 3424± 927μV, 00.05). 2) The mean value of F-wave amplitude was significantly reduced about 56.7% after the dentate stimulation(contro1 p u p , 443.2± 119μV stimulation p u p , 251.3±99.4μV, P<0.05). 3) The F/M ratio also significantly reduced about 56.8% after the dentate stimulation(contro1 group, 12.5±1.9%, stimulation group, 7.1± 1.2%, P<0.05). Our experimental results demonstrated that the dentate stimulation markedly decreased the sue of F-wave amplitude and F/M ratio in the experimental cats and we concluded that theseelectrophysiological changes can be applied as a parameter of clinical evaluation of electrical dentate stimulation for the spasticity.

척수손상후 운동 유발전위와 지각 유발전위의 비교

지철,이재수,하영수,최창락,송진언 대한신경외과학회 1987 Journal of Korean neurosurgical society Vol.16 No.4

Electrical monitoring of the nervous system offers the potential for the detection of injury, intraoperatively. The relationship of MEP(Motor Evoked Potential) and SEP(Sensory Evoked Potential) taken in 30 rats before and after spinal cord injury is reported. MEP was obtained from distal portion to the site of spinal cord injury by electrical stimulation of the cerebral motor cortex after insertion of a ball electrode in the cerebral motor cortex. SEP was collected at the cerebral somatosensory cortex during the sciatic nerve stimulation. Experimental animals were divided into a 20g㎝ spinal cord-trauma group and 50g㎝ spinal cord-trauma group. Changes of cardiopulmonary function after cerebral motor cortex stimulation and pre-and post-injury MEP and SEP were obtained at constant time interval. The results were follows : 1) Significant changes in blood pressure, pulse rate, and respiratory rate were noted to be elevated after stimulation of cerebral motor cortex and these were returned to normal in 10 minutes after stimulation. 2) MEP in control group showed that the latency was 8.6±1.54msec and the amplitude was 20.60±3.2㎶. In MEP of 20g㎝ spinal cord trauma group, the latency was increased to 30% (11.26±1.76msec) compared to control group at 10 minutes after the injury and the amplitude was decreased to 29% (14.60±2.99㎶). The latency was slowly decreased with the passage of time, to 21% increase. (10.42±1.84msec) at 1 hour after injury but the amplitude was not changed. In 50 g㎝ spinal cord-trauma group the latency was decreased to 75%(4.9±1.52㎶) compared to control group. With the passage of time, no change was revealed in latency but amplitude was decreased. The amplitude was decreased to 80%(4.00±1.49㎶) compared to control group. Change of MEP was marked in 50g㎝ spinal cord-trauma group. With the passage of time MEP was slightly improved in 20g㎝ spinal cord-trauma group but deteriorated in 50g㎝ spinal cord-trauma group. 3) The latency of SEP in control group was 12.22±0.7msec and the amplitude of those was 20.00±2.21㎶. No significant statistical change was recorded in the SEP of each spinal cord-trauma group compared to control group. MEP might be more important indicator than SEP in estimation and evaluation of the functional change of spinal cord injury.

Economic Threshold for Diamondback Moth (Plutella xylostella (L.) ) on Leaf Broccoli (Brassica oleracea var. botrytis italiana)

Seon-u Choi,Ju-Rak Lim,Ju-Hee Kim,Ki-Kwan Lee,Chang-yun Hwang 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

This study was conducted to develop the economic threshold for the diamondback moth (Plutella xylostella (L.) on Leaf Broccoli (leaf vegetable) in 2007. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 2.0, 4.0 larvae per plant) as initial density were established. We inoculated larvae in chesses cloth covering to survey larvae density change. When grown to eat, leaves of broccoli were harvested by periods. 60-70% of larvae were removed whenever we picked the leaves. High levels of larvae were associated with significant reductions in leaf yield. There were 85%, 64%, 58%, and 56% yield reductions from the diamond back moth larvae density in 0, 0.5, 1,0, 1.5, 2.0 per plant, respectively 25days after larvae inoculation. The regression equation used to predict leaf yield based on the number of initial larvae density per a plant was y=1635-393x(R2=0.79***). The economic injury level of diamondback moth on leaf broccoli was 2-3 larvae per 10 plants for a damage level of 5%. The economic thresholds was 1-2 larvae per 10 plants. Thus, the diamond back moth management should be initiated 1-2 larvae occurrence per plant.

미세조류의 Methane 발효특성

강창민,최명락 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

미세조류 Chlorella vulgaris를 기질로 하여 메탄발효에 의한 회분실험 및 연속실험을 실시한 결과, 다음과 같은 결론이 얻어졌다. 회분실험에서 조류의 분해는 경과 일수 10일을 기준하여 2단계로 구분 가능하고, 조류의 성분 중에서 분해되기 쉬운 부분은 최초의 10일간에 거의 분해되었다. 30일간의 회분실험에 있어, 기질 농도 1400~36000 mg/ℓ까지는 경시변화와 함께 가스 생성 속도가 직선적으로 증가하여, 적정 기질농도는 이 범위였다. 연속실험에 있어서는 중간대사물질인 용해성 유기물이 빠르게 소비되어, 반응조내에 축적되지 않았다. 즉 고형 유기물의 가수분해속도가 공정 전체를 제어했다. 생성되는 휘발성 유기산의 농도의 크기는 acetic acid>propionic acid>n-butylic acid>i-valeric acid>n-valeric acid>i-butylic acid의 순서였다. 조류의 분해가능성 유기물의 가수분해속도는 외견상 1차반응식으로 표현 가능하다. 또 가수분해속도정수는 VSS를 기준하여 K_h :0.23~0.28 day^-1, 난분해성 물질 비율(S_e/S_i)·100% : 72.2~84.2%가 구해졌다. 한편, 조류의 가용화를 위해 열처리, 알칼리처리 및 초음파처리에 의한 검토가 요구된다. This study was carried out to examine degradation characteristics of microalgae Chlorella vulgaris in methane fermentation. We measured COD and VS reduction, gas and methane productivity, VFA (volatile fatty acid), respectively. Then we calculated material balance and hydrolysis rates in soluble and solid material. The substrate concentration was controlled from 14 gCOD_cr/ℓ to 64 gCOD_cr/ℓ in batch cultures, and HRT (hydraulic retention time) controlled from 2 days to 30 days in continuous experiments. The results were as follows. In batch culture, accumulated gas productivity increased with the increase of the substrate concentration. The SS and VSS was removed all about 30% increase of substrate concentration and the most of the degradable material removed during the first 10 days. The curve of gas and methane production rate straightly increased until substrate concentration is 26 gCOD_cr/ℓ. In continuous culture experiments, the removal rates at HRT 10days were 20% for total COD and TOC, respectively. At longer HRT, there was no increase in the removal efficiency. At HRT 15 days, the removal rates were 30% for SS and VSS, respectively. Soluble organic materials were rapidly degraded, and so there was no accumulated. Soluble COD concentration was not increase regardless of HRT-increasing. That meaned the hydrolysis was one of the rate-limiting stage of methane fermentation. The first-order rate constants of hydrolysis were 0.23~0.28 day^-1 for VSS, and 0.07~0.08 day^-1 for COD.

FET형 반도체 바이오센서를 위한 웨이퍼 규모의 효소 고정화막 형성기술

김창수,조병옥,최성문,남동현,김의락,손병기 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

To improve the standardization of enzyme membranes for FET-type biosensor, wafer-scale formation technique had been studied by using photo-sensitive polymers. Glucose Oxidase, the enzyme which decomposes the glucose, had been used for application of this method to glucose sensors. Thin standardized memebranes could be obtained by spin coating of the mixed solution, composed of PVA-SbQ polymer and glucose oxidase, followed by photolithographic techniques. The performance characteristics of the glucose sensor having this thin enzyme membrane had been investigated.

백서의 질식성 심정지모델에서 N-acetylcysteine의 뇌신경보호 효과

박승현,최창락,오동렬,최세민,김세경 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: A major pathway leading toward neuronal injury following ischemia-reperfusion of the brain involves elevation of extracellular glutamate and activation of glutamate receptors, with a subsequent increase in intracellular calcium, resulting in a generation of free radicals. Oxygen free radicals cause brain injury following resuscitation from cardiac arrest. Oxyradicals produce strand breakage in DNA, which triggers energy-consuming DNA repair mechanisms and activates the nuclear enzyme poly(ADP-ribose) synthetase(PARS). However, excessive PARS activation leads to energy depletion and exacerbation of neuronal damage in cerebral ischemia. Methods: We investigated the effect of a potent, free-radical scavenger, N-acetylcysteine(NAC), on hippocampal neuronal death in an asphyxial cardiac arrest model of rats. The effect of NAC on hippocampal neuronal death was studied in 32 rats which were subjected to asphyxial cardiac arrest for 7 minutes, followed by resuscitation. The animals were divided into four group(8 rats in each group) as follows: Group I was saline treated for 3 days, Group II was NAC treated for 3 days, Group III was saline treated for 6 days, and Group IV was NAC treated for 6 days. In the NAC-treated groups, NAC(150㎎/kg) was intravenously injected after return of spontaneous circulation. The coronal sections with hippocampus levels were stained with hematoxylin-eosin(H-E) and PARS antibodies at 3 and 6 days after survival. In addition, the levels of myeloperoxidase(MPO) and malondialdehyde(MDA) were determined in the brains of each group. Results: The results are as follows: 1. MPO & MDA levels were significantly lower in the NAC-treated groups, II and IV, than in the saline-treated groups, I and III. 2. The histologic damage score(HDS), as determined by H-E staining, was significantly lower in the NAC-treated groups, II and IV, than in the saline-treated groups, I and III. 3. In PARS immunohistochemical staining, the HDS was significantly lower in the NAC-treated groups, II and IV, than in the saline-treated groups, I and III. Conclusion·. These results suggest that a free-radical scavenger, N-acetylcysteine, may effectively prevent neuronal damages after reperfusion from asphyxial cardiac arrest in rats. Further studies will be required to examine both the mechanism of the action and the clinical application of NAC in patients with cardiac arrest.

청신경종의 진단과 치료

안명수,최창락 한국의학사 1984 診斷과治療 Vol.4 No.4

정보 품질 성숙도 모델에 관한 연구

김창재,최용락,류성열,Kim Chang-Jae,Choi Yong-Rak,Rhew Sung-Yul 한국정보처리학회 2006 정보처리학회논문지D Vol.13 No.4

정보는 효과적으로 활용되어 이윤 창출에 기여하고, 신속하고 올바른 경영 판단을 지원하며, 재사용이 가능해야 하는 중요한 자원이다. 최근의 정보 시스템들은 사용자들의 다양한 요구를 반영하여 기업의 경쟁력을 높이고, 급변하는 환경 변화에 적응하기 위해 점차 대형화, 복잡화 되고 있으며 정보 품질의 중요성도 점차 강조 되고 있는 추세이다. 사용자들이 원하는 정보 제공에 있어 가장 큰 문제점은 저 품질의 데이터를 기반으로 하는 낮은 품질의 정보 제공에 있다. 낮은 정보 품질에 의해 기업 경영이 이루어질 경우 기업의 전략 수립, 전략 수행, 고객과 경쟁 기업에 대한 경영 집중력 분산 등 기업의 경영에 있어 경쟁력이 떨어 질 수밖에 없다. 낮은 품질의 정보는 부정확한 데이터를 개선하거나 조정하기 위한 시간 및 비용을 증가 시키고, 특정 현황에 대한 정확한 정보를 제공 받기가 어려워진다. 이러한 문제점들을 해결하기 위해서는 데이터에 대한 명확한 이해, 데이터 관리 체계 확립, 그리고 체계적인 데이터 관리 수행 등을 통하여 고품질의 데이터를 획득 할 수 있게 해야 한다. 현재까지 정보 품질과 관련된 연구 및 방법론은 부분적으로 진전이 있으나, 정보 품질 관리 전반에 대한 체계적인 방법론은 존재하지 않는 실정이다. 따라서 본 논문에서는 정보 품질 관리를 위한 프로세스들을 도출하고 정보 품질과 관련된 평가 요소를 도출하여 이를 정보 품질 보증 프로세스 단계인 CMM(Capacity Maturity Mode]) 5단계를 참조하여 제시한다. 본 논문은 정보 품질 개선 관리 프로세스 정립을 통해 기업의 정보 품질 관련 전략을 수립 하고, 경쟁력 있는 기업 또는 조직 활동에 이바지 하며, 품질 좋은 정보 활용에 따른 경쟁력 있는 운영에 이바지 하고자한다. Information is used effectively and contributes in profit creation and not only support management judgment quick but important resource to be possible recycled. The recent information systems improve enterprise's competitive power by reflection of user's various requirements and becoming big and complex for adaptation of rapidly circumstance change. Also it is trend that importance of information quality is emphasized gradually. The biggest problem in user requirement that is based on low quality data support. In case of business management is achieved by low quality information, company can not help dropping their competitive power such as company's strategy establishment, strategy achievement and management concentration breakup against competitor. Information of low quality increase time and expense to improve inaccurate data or revise and it is hard to accept correct information from specific situation. To solve these problems, we have to gain high quality data through definite comprehension, data management system establishment, and systematic data management achievement etc. Up to now, information quality and connected study were developed partially, but systematic methodology of information quality management's whole condition was not existed. Therefore, in this paper can show you how to extract process for information quality management & related evaluate factor with CMM (Capacity Maturity Mode]) 5 steps that is information warranty of quality process step. This paper whishes to contributes in competitive company or organization activity through information quality improvement management process.

완전뇌허혈후 재관류시에 국소뇌혈류, 체성감각유발전위 및 신경학적 회복에 대한 Mannitol과 Thiopental의 효과

박춘근,이상원,박영섭,최승진,허필우,정동섭,강준기,최창락 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.2

The cardiopulmonary bypass or cerebral circulation arrest is often used in the treatment of complex aneurysm or of arteriovenous malformation to decrease the risk of intraoperative aneurysm rupture. Although experimental studies have suggested that some drugs may protect the brain from ischemic injury, there are limitations in maintaining cerebral perfusion arrest without incurring neurologic deficits due to the initiation of detrimental processes including excitotoxic neuronal injury, activation of phospholipases, influx of calcium, and generation of damaging free radicals. The purpose of this study is to determine wheter mannitol or thiopental has any favorable effects on the recovery of neurologic deficits and on the regional cerebral blood flow(rCBF), somatosensory evoked potential(SEP) and electroencephalogram(EEG) in cats which underwent 15 minutes-complete global ishcemia-reperfusion. The complete global ischemia was produced in 38 cats by temporary intrathoracic occlusion of the innominate artery and the subclavian artery following ligation of bilateral mammary arteries and simultaneous induction of hypotension. The cats were allocated randomly to one of 4 treatment groups : (1) control group, 8 cats received equal volume of saline solution : (2) thiopental group, 10 cats received 45㎎/㎏ thiopental intravenously, (3) mannitol group, 10 cats received 2g/㎏ mannitol intravenously, (4) combined mannitol and thiopental group, 10 cats received equal dose of mannitol and thiopental intravenously. The drugs were administrated in a equally divided dosage before and after the ischemic episode. The results were as follos : 1) Eight animals which received saline showed the severe postischemic hypoperfusion and poor recovery of SEP and EEG, and 6 of them died within 6 hours after the ischemia. 2) Ten thiopental-treated animals also showed the severe postischemic hypoperfusion and poor recovery of SEP and EEG, and 6 of them died within 6 hours the ischemia. 3) Both mannitol-and combined treated groups showed early recovery of EEG, good recovery of SEP and EEG without the severe postischemic hypoperfusion, and 7 of 10 mannitol-treated animals and 8 of 10 combined treated animals were significantly recovered in all parameters. There were not significant differences in all parameters between the mannitol-and combined treated groups. 4) Thirty-four of 38 animals involved in this 15 minutes-ischemia resulted in the severe neurologic deficits inspite of treatment with mannitol, thiopental or both of them. These results suggest that, in cats, mannitol treatment is effective but not thiopental in preventing severe neurologic injury following complete global ischemia and the duration of complete ischemia should be far less than 15 minutes.

리튬-필로카르핀으로 유발된 경련중첩증 흰쥐에서 뇌량절개술의 효과

전신수,홍용길,박춘근,김문찬,최창락,강준기 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.5