• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.308-314
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• 1996

The crystal growth rate of benzene from benzene-cyclohexane mixtures at a cylindrical layer crystallizer was determined from the slope of the line of correlation between operating time and layer thickness. The thickness of crystal layer was obtained from the amount of crystal deposited on the cooled wall surface of the crystallizer. The crystal growth rate was related with the degree of subcooling, which was defined as the difference between temperature of melt and that of growing crystal surface. The linear crystal growth rate for binary mixtures was proportional to the second power of the degree of subcooling. Equation model which was obtained from data through the rate of heat and mass transfer in the crystallizer and thus can tell crystal thickness and surface temperature of crystal layer according to the elapsed time was presented and successfully correlated to the experimental data. For the benzene-cyclohexane mixtures contains 5wt% and 10wt% of cyclohexane, the comparison of experimental data with calculation using model equation was done for crystal thickness corresponding to the various cooling temperatures.

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.389-394
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• 2001

Cerebral dural sinus thrombosis(CDST) has been described as a rare disease with a variety of patho-etiological factors. The diagnosis of CDST is difficult due to various symptoms and signs, none of which is specific to CDST. But timely diagosis is critical for effective management. The introduction and widespread use of computed tomography(CT), magnetic resonance imaging(MRI) and cerebral angiography made early diagnosis of CDST possible. In particular, MR venography is the most useful tool for establishing a correct diagnosis quickly. In early literature, mortality ranked between 30% and 50% but in more recent series it is between 5.5% and 30%. With the advent of diagnostic and therapeutic tools, early diagnosis and proper management has made the prognosis better. The appropriate therapy for CDST, however, has been the subject of much cortroversy. Individual variations of the venous system and collateral vessels are key factors to decide the proper treatment. In this report, we present two cases with symptomatic CDST treated without open surgical or direct endovascular interventions with good outcome.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.551-557
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• 2001

Occlusion of the dural-sac in the lumbar spine was quantitatively analysed using a one motion segment finite element mode developed in this study. Occlusion was quantified by calculating the cross sectional area chance of the dural-sac. In static analysis. less than 2 kN of compressive load could Produced no dural-sac occlusion. whereas 6kN load reduced cross sectional area by 4%, and produced 7.4%, 10.5% occlusion for additional 8 Nm. 10 Nm extension moments. respectively. In creep analysis, 10 Nm extension reduced cross sectional area and volume of the dural-sac by 6.9% and 2.4%, respectively. However. flexion moment could not produce any occlusion. The results suggested that occlusions may result mainly from slackening of ligamentum flavum and disc budging.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.193-198
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• 2021

The purpose of spinal dural arteriovenous fistula (SDAVF) ligation is to prevent neurological injury and the poor blood supply through ligation of arteriovenous fistula. Therefore, intraoperative neurophysiological monitoring (INM) is required via multimodal neurological examination for minimizing the side effects after surgery based on the patient's symptoms. Transcranial electric motor-evoked potentials (TceMEP) help to check the condition of the corticospinal tract. Whenever ligation is performed, TceMEP should be performed every minute to check for abnormalities. However, an examiner's lack of knowledge about the operation procedure and examination and also poor communication between the examiner and surgeon can cause incorrect timing of the stimulation of TceMEP that interferes with the procedure and causes side effects such as paralysis and motor weakness. As a result of this SDAVF ligation survey, it is believed that for proper INM, case reports will be needed along with further research and the examiner will also have to work closely with the surgeon to minimize neurological damage to patients.

• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.112-117
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• 1999

Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.

• Journal of Oriental Neuropsychiatry
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• v.16 no.2
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• pp.189-199
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• 2005

We experienced a 71year-old man who had a traumatic subdural hemorrhage as well as delirium, and whose condition was improved through oriental medical treatment. Herbal medicine Hwaeo-jeon is administered three times a day. We did Mini-Mental State Examination-Korean(MMSE-K) and Korean-Dementia Rating Scale(K-DRS). After being treated, the patient showed that symptoms of delirium(diminished or altered state of consciousness, impairment of cognitive abilities or physical function) was improved considerably. This result suggests that Hwaeo-jeon has good effects on delirium with Traumatic Subdural Hemorrhage.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.430-433
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• 1996

It is common practice to use epidural catheter for anesthesia or for postoperative analgesia and other kinds of pain control. However, Intraspinal infection associated with this practice is rare event. We report a case of spinal subdural abscess occuring in patient who had recently received epidural catheterization. The cause in this case is not certain, although infection from the epidural catheter is the best possibility. We recommand an aseptic technique in all procedure for epidural or spinal analgesia.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.155-159
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• 1998

Epidural neurolysis with phenol has appeared in literature since 1960. Complications due to accidental subdural block is a rare and unexpected sensory and/or motor disturbance, but it does occur. A 74 years old woman had postherpectic neuralgia for 3 weeks and VAS score of 10. She was treated with intercostal nerve block and intravenous infusion of lidocaine for 7 days and VAS score decreased to 6. To proceed further, we decided to perform epidural neurolysis with 4% phenol 1.5 ml. During thoracic epidural catherization, we encountered unexpected subdural catheterization in subdurographic finding, but we could not precisely rule out subdural catheterization. We had to check CT for exact location of catheter tip. We then performed subdural neurolysis with phenol. This procedure reduced VAS score to between 3 and 4, and we removed the catheter. She had no complication.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.810-814
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• 2000

We report two cases of spinal subdural hematoma in the lumbar region after trauma. They developed in a 27-years old man and a 32-year-old woman. They had no other causes such as bleeding tendency, preexisting spinal lesions, lumbar puncture, vascular malformation and anticoagulant therapy. There lesions were diagnosed with MRI(fat suppression) and treated by lumbar puncture.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.275-278
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• 1996

The placement of epidural catheter may cause complications such as epidural hematoma, epidural abscess and neural damage. Among the above complications, epidural abscess is a rare but serious complication. This report pertains to a diabetic metlitus patient who developed spinal epidural and subdural abscess after continuous epidural catheterization for management of pain caused by reflex sympathetic dystrophy. The patient experienced urinary incontinence, as a neurologic sign, 8 days after epidural catherization. In was considered that the poor prognosis was due to a combination effects of a delayed visit to the hospital for treatment, rapid progression of abscess and uncontrolled blood sugar level. We therefore recommend aseptic technique and proper control of blood sugar level to prevent infection during and after epidural catheterization for diabetic patients. Early diagnosis of epidural abscess following surgical procedure must be required to avoid sequelae.