• Journal of Korean Neurosurgical Society
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• 제50권5호
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• pp.434-440
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• 2011

Objective : The goals of surgical intervention for metastatic spinal cord compression (MSCC) are prolonging survival and improving quality of life. Non-ambulatory paraplegic patients, either at presentation or after treatment, have a much shorter life expectancy than ambulatory patients. We therefore analyzed prognostic factors for survival and postoperative ambulation in patients surgically treated for MSCC. Methods : We assessed 103 patients with surgically treated MSCC who presented with lower extremity weakness between January 2001 and December 2008. Factors prognostic for overall survival (OS) and postoperative ambulation, including surgical method, age, sex, primary tumor site, metastatic spinal site, surgical levels, Tokuhashi score, and treatment with chemo- or radiation therapy, were analyzed retrospectively. Results : Median OS was significantly longer in the postoperatively ambulatory group [11.0 months; 95% confidence interval (CI), 9.29-12.71 months] than in the non-ambulatory group (5.0 months; 95% CI, 1.80-8.20 months) ($p$=0.035). When we compared median OS in patients with high (9-11) and low (0-8) Tokuhashi scores, they were significantly longer in the former (15.0 months; 95% CI, 9.29-20.71 months vs. 9.0 months; 95% CI, 7.48-10.52 months; $p$=0.003). Multivariate logistic regression analysis showed that preoperative ambulation with or without aid [odds ratio (OR) 5.35; 95% CI 1.57-18.17; $p$=0.007] and hip flexion power greater than grade III (OR 6.23; 95% CI, 1.29-7.35; $p$=0.038) were prognostic of postoperative ambulation. Conclusion : We found that postoperative ambulation and preoperative high Tokuhashi score were significantly associated with longer patient survival. In addition, preoperative hip flexion power greater than grade III was critical for postoperative ambulation.

• 한방재활의학과학회지
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• 제23권2호
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• pp.1-15
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• 2013

Objectives : In present study, we investigated the effects of ginsenoside Rg3 on early-stage inflammatory response in spinal cord compression of rodents. Methods : Spinal cord injury(SCI) was induced by a vascular clip method(30 g, 5 min) on the spinal cord of mice. Rg3 was treated orally at 1 hour prior to the SCI induction. Messenger ribonucleic acid(mRNA) expression of tumor necrosis factor-${\alpha}$(TNF-${\alpha}$), interleukin-1${\beta}$(IL-1${\beta}$), interleukin-6(IL-6) and cyclooxygenase-2(COX-2) was measured by the real-time polymerase chain reaction(RT-PCR). Microglia in the spinal cord tissue, neurophils and COX-2 in the peri-lesion and inducible nitric oxide synthase(iNOS) expression in the ventral horn of SCI induced rats were measured by immunohistochemical stain. Results : 1. Rg3 significantly reduced the mRNA expression of TNF-${\alpha}$, IL-1${\beta}$, and COX-2 in the spinal cord tissue compared with SCI group(p<0.05, p<0.01). 2. Rg3 significantly reduced the total number of activated microglia and proportion of phagocytic form in the total activated microglia compared with SCI group(p<0.05, p<0.01). 3. Rg3 significantly reduced myeloperoxidase(MPO) positive neurophil in the peri-lesion compared with SCI group(p<0.05). 4. Rg3 reduced the COX-2 expression in the tissue and motor neurons compared with SCI group. 5. Rg3 significantly reduced iNOS positive motor neurons in the ventral horn compared with SCI group(p<0.01). Conclusions : In conclusion, we demonstrated at first that treatment of ginsenoside Rg3 could reduce significantly the levels of inflammatory mediators in a spinal cord compression model of rodents. Therefore, these results suggested that ginsenoside Rg3 may be a useful antimiflamatory therapeutic candidate for SCI.

• 임산에너지
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• 제22권2호
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• pp.26-35
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• 2003

Bamboo strand board (BSB) was made with Phyllostachys banbusoides growing in Damyang district. Physical and mechanical properties of this BSB were summarized as follows; The specific gravity of BSB was 0.63∼0.79. Specific gravity decreased slightly with the thickness and length of BSB. Moisture content of BSB manufactured was 5.8∼6.9%. The absorption ate of BSB (42∼48%) did not show any relationship with the thickness and length of BSB. The thickness swelling rate of BSB was 13.9∼17.0%, relatively higher than any other panel products. Thickness swelling rate increased with the thickness of BSB, showing the strand thickness influenced much more on the rate of thickness swelling of BSB than the length of strand. The 3-point bending strength of BSB was 98∼126kgf/$\textrm{cm}^2$. Bending strength of showed the tendency of increase with the increased length of BSB, but with the decreased thickness. In particular, the length of BSB showed more effect on the increase of bending strength of BSB than the thickness of BSB. The compression strength perpendicular to BSB surface was 411 ∼ 465 kgf/$\textrm{cm}^2$, and the optimal length of strand for the 1mm- and 2mm-thickness of strand was 40mm and 60mm, respectively. Compression strength paralleled to BSD was 160∼221kgf/$\textrm{cm}^2$ and the optimal length of strand for the 2mm-thickness of strand appeared to be 60mm. The present work showed that appearance, physical and mechanical strength of BSB appeared quite positive in terms of board qualities, suggesting that bamboo would be appropriate for the production of board materials. In addition, our work showed that the crucial factor for determining the mechanical characteristics of BSB was the dimension of strand.

• 한국지반공학회논문집
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• 제20권9호
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• pp.125-131
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• 2004

본 연구에서는 준설토와 시멘트, 기포를 이용하여 제작한 경량기포혼합토에 대한 일련의 일축압축시험으로 경량기포혼합토의 역학적 거동에 미치는 준설토의 초기 함수비 및 시멘트 함유율의 영향을 정량적으로 조사하였다 또한, 기존의 연구결과(윤과 김, 2004)와의 비교검토를 통해 광양항 중마지역의 준설토를 채취하여 지역에 따른 경량기포 혼합토의 역학적 특성의 차이를 분석하였다. 일축압축시험결과 경량기포 혼합토의 변형계수$(E_{50})$는 시멘트 함유량이 증가하면서 그 크기도 증가하나 준설토의 초기함수비가 클수록 작게 나타났다. 또한, 경량혼합토의 구성요소인 준설토의 초기 함수비, 시멘트 함유량, 기포 함유량을 고려한 정규화계수로 표현되는 일축압축강도의 적절한 회귀식을 제시하였다. 본 연구의 결과, 경량기포혼합토의 역학적 특성은 준설토의 채취지역에 따라 다르므로 설계반영을 위해서는 적절히 실내실험을 통하여 검토해야 할 필요성이 있음을 확인하였다.

• 한국지반공학회논문집
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• 제19권2호
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• pp.7-14
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• 2003

본 연구는 광양만 지역과 목포 남악지역의 점토를 이용하여 양생온도를 20$\times$, 50$\times$ , 80$\times$로 달리하고 각각의 온도에서 양생기간을 1일, 7일 14일, 40일로 하여 재성형.재압밀 시료를 제작하여 양생온도.양생기간이 연대효과 재현에 어떤 영향이 있는지를 밝히고, 불교란시료와 재압밀된 점토의 역학적 특성과 연대효과의 특성을 알아보기 위하여 1축압축시험, 3축압축시험 그리고 표준압밀시험을 실시하였다. 그 결과 압축지수비는 원지반점토의 연대효과를 나타내는데 유용한 지수임을 확인할 수 있었으며 또한 고온으로 양생한 점토가 연대효과를 잘 표현하고 연대효과의 재현에 필요한 최적의 양생온도는 80$\times$ 정도 부근이고 양생기간은 27일정도 임을 알 수 있었다.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.357-363
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• 2005

Objective: The microvascular decompression(MVD) for trigeminal neuralgia(TN) is known as an effective surgical technique. But the failed MVD cases have been reported in long term follow-up studies. This study is to evaluate the efficacy of MVD through our operative techniques, offending vessels in operative field, failed cases with the review of the literatures. Methods: We analyzed total 63 cases of TN which underwent MVD from 1955 to 2003 according to characters of pain, operative findings, operative results related to causative vessel compression and operative method, progonotic factor. Statistical analysis was performed using paired t-test with SPSS Ver 11.0. Results: In TN, the most common offending vessel was superior cerebellar artery(45.0%). In compression group of nerve root by offending vessel, the cure rate was 91.7%. However, the cure rate of the contact group was 64.7% and the cure rate of the negative group was 37.5%. There was no statistical significance between the degree of compression by vessel and the operative result(p=0.076). In 51 cases with MVD only, the cure rate was 84.3% and in 3 cases with PSR only, 42.8% and in 2 cases with PSR(partial sensory rhizotomy) with MVD, 50.0%. TN recurred in 7 cases within the follow-up period and reoperations(PSR) were added in 2 cases of them. Conclusion: This study shows that MVD provided a high rate of success with a minor risk of complications, which has been regarded as the most safe and effective procedure for trigeminal neuralgia. Additional MVD in recurred TN by severe adhesion of teflon showed poor outcome. But, revisional operation(PSR) in recurred TN showed relatively good outcome. PSR should be considered for treatment of recurrent TN after MVD.

• 한국안전학회지
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• 제37권4호
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• pp.36-43
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• 2022

Generally, in construction sites, the pipe support installation workers often use support pins of 9~10 mm which are much smaller than the safety standard sizes for work convenience. Although the safety certification standard thickness of the support pins is 11 mm, and the supervisors are often indifferent to this. Hence, products with far lower performance than the pipe support safety certification value of 40,000 N, which is applied in the supporting post-structural review, are used. Accordingly, this acts as a factor causing collapse accidents in the process of pouring concrete at the construction site. Therefore, this study performed compression experiments on new and reused pipe supports to determine how the thickness of the support pins affects the structural compression performance of the pipe support by considering the thickness of the support pins as a critical variable among various factors affecting the pipe support performance. In the course of the study, the compression test of the pipe support (V2, V4) for the new products showed that only 14 (58.3%) of the total 24 samples satisfied the safety certification standard value of 40,000 N, which indicates that more thorough quality control is required in the manufacturing process. Additionally, comparing the thickness of the support pins and their fracture shape shows that the pipes with support length of 4.0 m or longer are much more affected by the buckling of the entire length than the thickness of the support pins. Of the several factors affecting the performance of reused pipe supports, it was found that, similar to the new products, the use of support pins, with thickness of 12 mm rather than 11 mm, can satisfy the safety certification value more appropriately. Therefore, regardless of the state of usage, it could be concluded that it is necessary to use 12 mm products, whose thickness is larger than that of the safety certification standard value of 11 mm, to improve the performance of the pipe supports.

• Journal of Korean Neurosurgical Society
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• 제57권2호
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• pp.73-76
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• 2015

Objective : Tumor necrosis factor alpha (TNF-${\alpha}$) have proven effects in pathogenesis of neuroinflammation after spinal cord injury (SCI). Current study is designed to evaluate the effects of an anti-TNF-${\alpha}$ agent, adalimumab, on spinal cord clip compression injury in rats. Methods : Thirty two male adult Wistar rats were divided into four groups (sham, trauma, infliximab, and adalimumab groups) and SCI was introduced using an aneurysm clip. Animals in treatment groups received 5 mg/kg subcutaneous adalimumab and infliximab right after the trauma. Malondialdehyde (MDA) levels were studied in traumatized spinal cord tissues 72 hours after the injury as a marker of lipid peroxidation. Results : Animals that received anti-TNF-${\alpha}$ agents are found to have significantly decreased MDA levels. MDA levels were significantly different between the trauma and infliximab groups (p<0.01) and trauma and adalimumab groups (p=0.022). There was no significant difference in neurological evaluation of the rats using Tarlov scale. Conclusion : These results suggest that, like infliximab, adalimumab has favorable effects on lipid peroxidation induced by spinal cord trauma in rats.

• 한국안전학회지
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• 제27권5호
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• pp.117-125
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• 2012

In recent years, polymer concrete based on polyester resin have been widely generalized and the research of polymer concrete have been actively pursued by the technical innovations. Polymer concrete is a composite consisting of aggregates and an organic resin binder that hardens by polymerization. Polymer concrete are stronger by a factor of three or more in compression, a factor of four to six in tension and flexural and a factor of two in impact when compared with portland cement concrete. In view of the growing use of polymer concrete, it is important to study the physical characteristics of the material, emphasizing the short term properties as well as long term mechanical behavior. If polymer concrete is to be used in flexural load-bearing application such as in beam, it is imperative to understand the deformation of the material under sustained loading conditions. This study is proposed to empirical and mechanical model of polymer concrete tension creep using long-term experimental results and mathematical development. The test results showed that proposed model has been used successfully to predict creep deformations at a stress level that was 20 percent of the ultimate strength and viscoelastic behavior of recycled-PET polymer concrete is linear of stress level up to 30 percent. It is expected that the present model allows more realistic evaluation of varying stresses in polymer concrete structures with a constant loading.

• Structural Engineering and Mechanics
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• 제58권1호
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• pp.1-19
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• 2016

Recently, the high-strength concrete is increasingly used in the construction of reinforced concrete structures due to its benefits, but this use is influenced negatively on the local ductility of structural elements. The objective of this study is the prediction of a new approach to evaluate the curvature ductility factor of high strength concrete beams according to Eurocode 2. After the presentation of the Constitutive laws of materials and the evaluation method of curvature ductility according to the Eurocode 2, we conduct a parametric study on the factors influencing the curvature ductility of inflected sections. The calibrating of the obtained results allows predicting a very simple approach for estimating the curvature ductility factor. The proposed formula allows to calculate the curvature ductility factor of high strength concrete beams directly according to the concrete strength $f_{ck}$, the yield strength of steel $f_{yk}$ and the ratio of tension and compression reinforcements ${\rho}$ and ${\rho}^{\prime}$ respectively, this proposed formula is validated by theoretical and experimental results of different researchers.