• Journal of the Microelectronics and Packaging Society
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• v.8 no.4
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• pp.25-33
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• 2001

Sn-3.5Ag-xBi alloys with five different levels of Bi (0, 2.5, 4.8, 7.5, 10 wt%) were prepared for evaluating creep properties. Cast alloys were roiled and heat treated to provide stable microstructures during the subsequent creep tests, which were conducted under constant load using dog-bone specimens. For the Bi containing alloys, creep strength showed the maximum around 2.5 wt%Bi and tended to decrease with increasing Bi content. The stress exponent of the alloy was around 4, suggesting typical dislocation creep, but the exponent was 2 for the 10 wt%Bi alloy, suggesting creep assisted by grain boundary Sliding. For the Bi containing alloys, the brittle fracture mode appeared showing small amount of reduction of area, while the ductile fracture mode was true for the Bi free alloy. Microstructural examination of ruptured specimens showed cavitations on grain boundaries normal to the load axis, and a significant of grain boundary sliding for the Bi containing alloys.

• BMB Reports
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• v.41 no.2
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• pp.119-125
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• 2008

Our previous work confirmed that Sph2/LA1029 was a sphigomyelinase-like hemolyisn of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai. Characteristics of both hemolytic and cytotoxic activities of Sph2 were reported in this paper. Sph2 was a heat-labile neutral hemolysin and had similar hemolytic behavior as the typical sphingomyelinase C of Staphylococcus aureus upon sheep erythrocytes. The cytotoxic activity of Sph2 was shown in mammalian cells such as BALB/C mouse lymphocytes and macrophages, as well as human L-02 liver cells. Transmission electron microscopic observation showed that the Sph2 treated BALB/C mouse lymphocytes were swollen and ruptured with membrane breakage. They also demonstrated condensed chromatin as a high-density area. Cytoskeleton changes were observed via fluorescence confocal microscope in Sph2 treated BALB/C mouse lymphocytes and macrophages, where both cytokine IL-$1{\beta}$ and IL-6 were induced. In addition, typical apoptotic morphological features were observed in Sph2 treated L-02 cells via transmission electron microscope and the percentage of apoptotic cells did increase after the Sph2 treatment detected by flow cytometry. Therefore, Sph2 was likely an apoptosis-inducing factor of human L-02 liver cells.

• Journal of Korean Neurosurgical Society
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• v.57 no.3
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• pp.159-166
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• 2015

Objective : We reviewed the feasibility, safety and efficacy as well as the clinical outcome and long-term angiographic results of endovascular treatment (EVT) of the anterior communicating artery (ACoA) aneurysms. Methods : A total of 429 ACoA aneurysms in 426 patients were treated using coil embolization between March 1996 and October 2010 in a single institution. Pretreatment aneurysmal features were checked using angiogram. We had usually used tailored steam shaped microcatheter according to individual angiographic architectures. Immediate postembolization outcomes were evaluated using an angiographic outcome scale and clinical evaluation was performed using the Glasgow Outcome Scale (GOS). Results : Postembolization angiograms demonstrated total occlusion of aneurysm in 290 of 429 (67.6%) aneurysms, neck remnant in 80 (18.6%) and body filling in 59 (13.8%). Dome direction and aneurysm angle was not associated with initial angiographic outcomes. The procedure-related morbidity rate was 0.9% (4 of 429). Clinical and imaging follow-up more than 6 months were available in 382 (89.0%) patients with a mean of 26.2 months. Overall rate of major recanalization was 7.9% (30 of 382) and all of them were retreated without complications. At the last follow-up, 233 (99.2%) of 235 patients had GOS of 5 in unruptured group, and 152 (79.5%) of 191 patients showed good clinical outcomes (GOS of 4 or 5) in ruptured group. Conclusion : Tailored steam shaping of the microcatheter is vital to achieve good angiographic outcomes regardless of aneurysmal direction. EVT is feasible and safe for most ACoA aneurysms with acceptable immediate and long-term outcomes.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.116-122
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• 2009

Objective: Intracranial arteriovenous malformation (AVM) associated with aneurysm has been infrequently encountered and the treatment for this malady is challenging. We report here on our clinical experience with AVMs associated with arterial aneurysms that were managed by multimodality treatments, including clipping of the aneurysm, microsurgery, Gamma-knife radiosurgery (GKS) and Guglielmi detachable coil (GDC) embolization. Methods: We reviewed the treatment plans, radiological findings and clinical courses of 21 patients who were treated with GKS for AVM associated with aneurysm. Results: Twenty-seven aneurysms in 21 patients with AVMs were enrolled in this study. Hemorrhage was the most frequent presenting symptom (17 patients: 80.9%). Bleeding was caused by an AVM nidus in 11 cases, aneurysm rupture in 5 and an undetermined origin in 1. Five patients were treated for associated aneurysm with clipping followed by GKS for the AVM and 11 patients were treated with GDC embolization combined with GKS for an AVM. Although 11 associated aneurysms remained untreated after GKS, none of them ruptured and 4 aneurysms regressed during the follow up period. Two aneurysms increased in size despite the disappearance of the AVM nidus after GKS and then these aneurysms were treated with GDC embolization. Conclusion: If combined treatment using microsurgery, GKS and endovascular treatment can be adequately used for these patients, a better prognosis can be obtained. In particular, GKS and GDC embolization are considered to have significant roles to minimize neurologic injury.

• Journal of Korean Neurosurgical Society
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• v.46 no.2
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• pp.99-102
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• 2009

Objective: Cardiac dysfunction after aneurysmal subarachnoid hemorrhage (SAH) is associated with elevation of serum cardiac troponin I (cTnl) levels. Elevation of cTnl predicts cardiopulmonary and neurological complications, and poor outcome. Methods: We retrospectively reviewed the medical and radiologic records of 114 (male: 30, female: 84) patients who developed aneurysmal SAH between January 2006 and June 2007 and had no history of previous cardiac problems. We evaluated their electrocardiography and cTnl level, which had been measured at admission. A cTnl level above 0.5 $\mu$g/L was defined as an indicator of cardiac injury following SAH. We examined various clinical factors for their association with cTnl elevation and analyzed data using chi-square test, t-test and logistic regression test with SPSS version 12.0. The results were considered significant at p< 0.05. Results: The following parameters shows a correlation with cTnl elevation: higher Hunt-Hess (H-H) grade (p = 0.000), poor Glasgow Outcome Scale (GOS) score (p = 0.000), profound pulmonary complication (p = 0.043), higher heart rate during initial three days following SAH (p = 0.029), ruptured aneurysm on communicating segment of internal carotid artery (p = 0.025), incidence of vasospasm (p = 0.421), and duration of hyperdynamic therapy for vasospasm (p = 0.292). A significant determinants for outcome were cTnl elevation (p = 0.046) and H-H grade (p = 0.000) in a multivariate study. Conclusion: A cTnl is a good indicator for cardiopulmonary and neurologic complications and outcome following SAH. Consideration of variable clinical factors that related with cTnl elevation may be useful tactics for treatment of SAH and concomitant complications.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.146-154
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• 2017

Objective : The semi-jailing technique (SJT) provides stent-assisted remodeling of the aneurysm neck during coil embolization without grasping the coil delivery microcatheter. We retrospectively evaluated the efficacy and safety of SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms. Methods : We collected the clinical and radiological data between January 2009 and June 2015 of the wide-necked aneurysms treated with SJT using a Neuroform3 stent. Results : SJT using a Neuroform3 stent was attempted in 70 wide-necked aneurysms (68 patients). There were 56 unruptured and 14 ruptured aneurysms. The size of aneurysm ranged from 1.7 to 28.1 mm (mean 6.1 mm). The immediate angiographic results were complete occlusion in 55 aneurysms (78.6%), neck remnant in 7 (10.0%), and aneurysm remnant in 8 (11.4%). Overall, periprocedural complications occurred in 13 patients (19.1%), including asymptomatic thromboembolism in 7 (10.3%), symptomatic thromboembolism in 4 (5.9%), and symptomatic hemorrhagic complications in 2 (2.9%). Conventional angiography follow-up was obtained in 55 (78.6%) of 70 aneurysms (mean, 10.9 months). The result showed progressive occlusion in 7 aneurysms (12.7%) and recanalization in 1 aneurysm (1.8%). At the end of the observation period (mean, 17.5 months), all 54 patients without subarachnoid hemorrhage showed excellent clinical outcomes (modified Rankin Scale [mRS] 0), except two (mRS 1 or 2) and seven of 14 patients with subarachnoid hemorrhage remained symptom-free (mRS 0). Conclusion : In this report of 70 aneurysms, SJT using a Neuroform3 stent for coiling of wide-necked intracranial aneurysms showed good technical safety, as well as favorable clinical and angiographic outcomes.

• Journal of Korean Neurosurgical Society
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• v.63 no.4
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• pp.415-426
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• 2020

Arteriovenous malformations (AVMs) are congenital anomalies of the cerebrovascular system. AVM harbors 2.2% annual hemorrhage risk in unruptured cases and 4.5% annual hemorrhage risk of previously ruptured cases. Stereotactic radiosurgery (SRS) have been shown excellent treatment outcomes for patients with small- to moderated sized AVM which can be achieved in 80-90% complete obliteration rate with a 2-3 years latency period. The most important factors are associated with obliteration after SRS is the radiation dose to the AVM. In our institutional clinical practice, now 22 Gy (50% isodose line) dose of radiation has been used for treatment of cerebral AVM in single-session radiosurgery. However, dose-volume relationship can be unfavorable for large AVMs when treated in a single-session radiosurgery, resulting high complication rates for effective dose. Thus, various strategies should be considered to treat large AVM. The role of pre-SRS embolization is permanent volume reduction of the nidus and treat high-risk lesion such as AVM-related aneurysm and high-flow arteriovenous shunt. Various staging technique of radiosurgery including volume-staged radiosurgery, hypofractionated radiotherapy and dose-staged radiosurgery are possible option for large AVM. The incidence of post-radiosurgery complication is varied, the incidence rate of radiological post-radiosurgical complication has been reported 30-40% and symptomatic complication rate was reported from 8.1% to 11.8%. In the future, novel therapy which incorporate endovascular treatment using liquid embolic material and new radiosurgical technique such as gene or cytokine-targeted radio-sensitization should be needed.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.1
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• pp.175-184
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• 2018

The purpose of this study is to report the effectiveness of complex Korean Medicine treatment for anterior cruciate ligament (ACL) injuries with meniscus tear. Four patients were treated with complex Korean Medicine by acupuncture, pharmacopuncture and herbal medication. We evaluated the improvement of knee pain and function by Numeric Rating Scale (NRS), Western Ontario and McMaster Universities Arthritis Index (WOMAC Index), EuroQol-5 Dimension Index (EQ-5D Index). After treatment, we found that knee pain was reduced and joint function was improved by NRS and WOMAC index in all cases. In the evaluation of health-related quality of life through EQ-5D index, there was no significant difference in patients with degenerative knee osteoarthritis and severe meniscal injury. This results show that complex Korean Medicine may be an effective option for ACL injuries with meniscus tear. Further clinical studies are needed to clarify the effect of Korean Medicine therapy on ACL injuries with meniscus tear.

• Journal of Korean Neurosurgical Society
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• v.52 no.5
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• pp.441-446
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• 2012

Objective : Shunt-dependent chronic hydrocephalus (SDCH) is known to be a major complication associated with aneurysmal subarachnoid hemorrhage (aSAH). Old age is known to be one of numerous factors related to the development of SDCH. This study investigated whether postoperative cisternal drainage affects the incidence of SDCH and clinical outcome in elderly patients with aSAH. Methods : Fifty-nine patients participated in this study. All patients underwent aneurysmal clipping with cisternal cerebrospinal fluid (CSF) drainage. Clinical variables relevant to the study included age, sex, location of ruptured aneurysm, CT finding and clinical state on admission, clinical outcome, and CSF drainage. We first divided patients into two groups according to age (<70 years of age and ${\geq}70$ years of age) and compared the two groups. Secondly, we analyzed variables to find factors associated with SDCH in both groups (<70 years of age and ${\geq}70$ years of age). Results : Of 59 patients, SDCH was observed in 20 patients (33.9 %), who underwent shunt placement for treatment of hydrocephalus. Forty seven percent of cases of acute hydrocephalus developed SDCH. In the elderly group (${\geq}70$ years of age), the duration and amount of CSF drainage did not affect the development of chronic hydrocephalus. Conclusion : In elderly patients, although the incidence of SDCH was significantly higher, clinical outcome was acceptable. The duration and the amount of cisternal drainage did not seem to be related to subsequent development of chronic hydrocephalus within elderly patients aged 70 or older.

• Journal of Korean Neurosurgical Society
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• v.44 no.3
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• pp.136-140
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• 2008

Objective : Numerous studies have compared the characteristics of familial intracranial aneurysms with those of non-familial aneurysms. To better understand familial subarachnoid hemorrhage (SAH), we studied a series of patients with SAH who had at least one first-degree relative with SAH, and compared our results with those of previous studies. Methods : We identified patients treated for SAH at our hospital between January 1993 and October 2006 and analyzed those patients with one or more first-degree relatives with SAH. We retrospectively collected data from patients with a family history and searched for patients who had relatives with aneurysms or who had been treated at other hospitals for SAH. Results : We identified 12 patients from six families with at least two first-degree relatives with SAH. All patients had affected first-degree relatives; in five families, they were siblings. The mean age at the time of rupture was 49.75 years; in four families, the age difference was within 5 years. In five patients (42%), the aneurysm was located in the middle cerebral artery. Only one patient had an aneurysm in the anterior communicating artery. Conclusion : In agreement with previous studies, our results showed that familial aneurysms, in comparison with non-familiar aneurysms, ruptured at a younger age and smaller size, had a high incidence in the middle cerebral artery, and were underrepresented in the anterior communicating artery. Interestingly, the age at the time of rupture was similar between relatives. Screening should be considered in the fifth or sixth decade for those who have a sibling with SAH.