• Journal of Korean Neurosurgical Society
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• 제38권1호
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• pp.41-46
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• 2005

Objective : A study of the histopathologic and neurobehavioral correlates of cortical impact injury produced by increasing impact velocity using the controlled cortical impact[CCI] injury model is studied. Methods : Twenty-four Sprague-Dawley rats [$200{\sim}250g$] were given CCI injury using a pneumatically driven piston. Effect of impact velocity on a 3mm deformation was assessed at 2.5m/sec [n=6], 3.0m/sec [n=6], 3.5m/sec [n=6], and no injury [n=6]. After postoperative 24hours the rats were evaluated using several neurobehavioral tests including the rotarod test, beam-balance performance, and postural reflex test. Contusion volume and histopathologic findings were evaluated for each of the impact velocities. Results : On the rota rod test, all the injured rats exhibited a significant difference compared to the sham-operated rats and increased velocity correlated with increased deficit [p<0.001]. Contusion volume increased with increasing impact velocity. For the 2.5, 3.0, and 3.5m/sec groups, injured volumes were $18.8{\pm}2.3mm^3$, $26.8{\pm}3.1mm^3$, and $32.5{\pm}3.5mm^3$, respectively. In addition, neuronal loss in the hippocampal sub-region increased with increasing impact velocity. In the TUNEL staining, all the injured groups exhibited definitely positive cells at pericontusional area. However, there were no significant differences in the number of positive cells among the injured groups. Conclusion : Cortical impact velocity is a critical parameter in producing cortical contusion. Severity of cortical injury is proportional to increasing impact velocity of cortical injury.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권2호
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• pp.100-104
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• 2023

Autogenous bone grafts from the mandibular ramus are a known source of inadequate bone volume scenarios of the residual alveolar ridge. However, the conventional block-type harvesting technique cannot prevent bone marrow invasion, which can cause postoperative complications such as pain, swelling, and inferior alveolar nerve injury. This study aims to suggest a complication-free harvesting technique and present the results of bone grafting and donor sites. One patient received two dental implants with a complication-free harvesting technique that involves creation of ditching holes with a 1 mm round bur. Sagittal, coronal, and axial osteotomies produced grid-type cortical squares using a micro-saw and a round bur to confirm the cortical thickness. The grid-type cortical bone was harvested from the occlusal aspect, and the harvesting was extended through an additional osteotomy on the exposed and remaining cortical bone to prevent bone marrow invasion. The patient did not suffer postoperative severe pain, swelling, or numbness. After 15 months, the harvested site exhibited new cortical bone lining, and the grafted area had healed to a cortico-cancellous complex with functional loading of the implants. Our technique, grid-type cortical bone harvesting without bone marrow invasion, allowed application of autogenous bone without bone marrow invasion to achieve acceptable bone healing of the dental implants and to regenerate the harvested cortical bone.

• Imaging Science in Dentistry
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• 제33권4호
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• pp.211-215
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• 2003

Purpose: To assess the radiographic findings of odontogenic cysts showing displacement of the mandibular canal using computed tomographic (CT) and panoramic images. Materials and Methods : CT and panoramic images of 63 odontogenic cysts (27 dentigerous, 16 odontogenic keratocysts, and 20 radicular cysts) were analyzed to evaluate the following parameters: the dimension and shape of the cysts, and the effect of the cysts on the mandibular canal and cortical plates. Results: Of the 63 cysts examined in the study, 35 (55.6%) showed inferior displacement of the mandibular canal and 46 (73.0%) showed perforation of the canal. There were statistically significant differences between CT and panoramic images in depicting displacement and perforation of the mandibular canal. Cortical expansion was seen in 46 cases (73.0%) and cortical perforation in 23 cases (36.5%). The radicular cysts showed cortical expansion and perforation less frequently than the other cyst groups. Conclusion: Large cysts of mandible should be evaluated by multiplanar CT images inorder to detect the mandibular canal and cortical bone involvement.

• Natural Product Sciences
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• 제15권3호
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• pp.125-129
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• 2009

Neurodegenerative diseases such as Alzheimer's disease, stroke, and Parkinson's disease, are caused by neuronal cell death. Apoptosis, oxidative stress, inflammation, excitotoxicity or ischemia are discussed to play a role of neuronal cell death. In order to find the candidate of neuroprotective agent, neuroprotective activity of some medicinal plants was investigated with in vitro assay system using glutamate-induced neurotoxicity in primary cultures of rat cortical cells. The aqueous methanolic extracts of twenty-seven medicinal plants were evaluated the protective effects against glutamate-injured excitotoxicity in rat cortical cells at the concentration of 50 $\mu$g/ml and 100 $\mu$g/ml, respectively. Among them, extracts of Lonicera japonica, Taraxacum platycarpum, Polygonum aviculare, Gardenia jasminoides, Forsythia viridissima, Lygodium japonicum, Panax notoginseng, Akebia quinata, Anemarrhena asphodeloides and Phellodendron amurense showed significantly neuroprotective activities against glutamate-induced neurotoxicity in primary rat cortical cells.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.527-528
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• 2006

In the proposed research plan, the effects of anisotropic and time-dependent mechanical properties on nanoindentation measurements of osteonic lamellae in a human cortical bone are investigated. The most popular method(Oliver-Pharr method) in nanoindentation data analysis is based on the assumption of elastic isotropy. Since cortical bone has exhibited anisotropy, it is necessary to consider the effects of anisotropy on nanoindentation measurement for cortical bone. By comparison with the contact area obtained from monitoring the contact profile in FEA simulations, the Oliver-Pharr method was found to underpredict or overpredict the contact area due to effects of anisotropy. The mount of error depended on the indentation orientation. The indentation modulus results and were also similar to moduli calculated from mathematical model. The Oliver-Pharr method has been shown to be useful for providing first order approximations in analysis of anisotropic mechanical properties of cortical bone, although the indentation modulus is influenced by anisotropy.

• Imaging Science in Dentistry
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• 제41권4호
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• pp.151-153
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• 2011

Purpose : The purpose of this study was to obtain the description of the mandibular bone quality of male and female patients between 40-60 years old and their differences based on mandibular cortical bone thickness measured using Mental Index (MI). Materials and Methods : Forty digital panoramic radiographs, which consisted of twenty male and twenty female patients, 40-60 years old, were observed. Mandibular cortical bone thickness was measured using MI on both sides of the mandible. The average MI score of two groups were then assessed using t-sample independent test. Results : There were significant differences of mandibular bone quality based on mandibular cortical bone thickness measurement using MI between male and female patients (p<0.05). Conclusion : Mandibular bone quality based on cortical bone thickness measurement using MI of male and female patients indicated a significant difference.

• 약학회지
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• 제41권1호
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• pp.111-116
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• 1997

The neurotoxicity induced by L-glutamate in primary cultures of rat cortical cells could be attenuated by sesquiterpene constituent of Ginkgo biloba leaves, bilobalide. At the c oncentration of 100 nM, Bilobalide elevated the combined levels of reduced/oxidized glutathione in rat cortical cells exposed to 100 ${\mu}$M glutamate. Furthermore, bilobalide promoted a reduction in superoxide dismutase activity in glutamate-treated cells. Finally, bilobalide markedly inhibited the production of malondialdehyde. a measure of lipid peroxidation, in glutamate-treated rat cortical cells.

• Journal of Chest Surgery
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• 제27권9호
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• pp.785-792
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• 1994

In this study, the authors analyzed the prognostic value of four clinical variables[age and sex of patients, association with myasthenia gravis and clinical stage] and histological type in 30 consecutive patients with thymoma, histologically classified as cortical[10],medullary[5] and mixed[15]type according to Marino and Muller-Hermelink classification. There were significant differences between the histological types in the frequency of the different tumor stages and myasthenia gravis and prognosis.Most of the cortical thymomas were at stage III and all of the medullary and most of the mixed tumors at stage I or II.Myasthenia gravis occurred more commonly in patients with cortical[30%] and mixed thymoma[60%] than in patients with medullary thymoma[10%]. Follow-up was conducted in 30 patients,with follow-up range from 3 months to 120 months[mean,47.3months]. 5 year actuarial survival was 100% for medullary thymoma, 73% for mixed thymoma, and 47% for cortical thymoma.The overall survival curve shows that 87.6% of the patients are alive at 2 years and 72.8% at 5 years. And 7 patients was dead during follow-up periods.By Kaplan-Meier technique, we found that the patients who had myasthenia gravis had better prognosis[P<0.05]. Medullary thymoma is a comparatively rare, benign tumor, and usually not associated with myasthenia gravis. Cortical thymoma must be regarded as malignant. Mixed thymoma is intermediate in its behavior between medullary and cortical thymoma. But these tumors should be considered potentially malignant despite of presence as stage I of II disease. Also, the patients with stageI,II had good prognosis and the patients with total resection had good prognosis[P<0.05].

• 대한수의학회지
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• 제37권1호
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• pp.111-117
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• 1997

This study was carried out determine the effect of renal ischemia on amino acid transport in rabbit renal cortical slices. The animal models of renal ischemia induced experimentally by clamping the renal artery. These results were summarized as follows: 1. The uptake of amino acids lysine and ${\alpha}$-aminobutyrate(AIB), dicarboxylate succinate and organic anion PAH in cortical slices was normal or increased after 30 or 60 min of ischemia in vivo. 2. In a 30 min ischemic kidney, the slice uptake of amino acids was returned to the control level by 30 min of reflow. In a 60 or 90 min ischemic kidney, the lysine uptake was returned to the control level after of reflow, but the uptake of AIB and succinate was significantly reduced during reflow period of 30-120 min. 3. Oxygen consumption in cortical slices was increased after 30 min of ischemia but was not altered by 60 min of ischemia. This results indicat that transient ischemia caused increasing of amino acid uptake in renal cortical slices without metabolic disorder of renal proximal tubule.

• 한국음향학회지
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• 제30권1호
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• pp.56-62
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• 2011

본 연구에서는 생체 외 조건에서 12개의 관형 피질골 샘플에 대하여 피질골 샘플의 축방향을 따라 전파하는 first arriving signal (FAS) 및 slow guided wave (SGW)와 같은 유도초음파의 위상속도를 측정하고, 각각의 위상속도와 피질골 두께 사이의 상관관계를 고찰하였다. FAS 및 SGW의 위상속도는 12.7 mm의 직경 및 200 kHz의 중심 주파수를 갖는 한 쌍의 비집속형 초음파 변환기와 함께 공기중에서 축방향 전파법을 이용하여 측정되었다. 200 kHz에서 측정된 FAS의 위상속도는 피질골 두께와 매우 높은 음의 상관관계를 나타냈으며, FAS 이후에 수신되는 SGW의 위상속도는 피질골 두께와 높은 양의 상관관계를 나타냈다. FAS 및 SGW의 위상속도를 독립변수로 하고, 피질골 두께를 종속변수로 하는 단순 및 다중선형회귀모델의 결과로부터 다중선형회귀모델의 결정계수가 단순선형회귀모델의 결정계수보다 높게 나타났다. 또한 12개의 관형 피질골 샘플에 대하여 200 kHz에서 측정된 FAS 및 SGW의 위상속도는 각각 판형 피질골에 대하여 200 kHz에서 계산된 S0 및 A0 램 모드의 위상속도와 잘 일치하였다.