• The korean journal of orthodontics
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• v.41 no.6
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• pp.423-430
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• 2011

Objective: To evaluate the extent and aspect of stress to the cortical bone after application of a lateral force to a two-component orthodontic mini-implant (OMI, mini-implant) by using three-dimensional finite element analysis (FEA). Methods: The 3D-finite element models consisted of the maxilla, maxillary first molars, second premolars, and OMIs. The screw part of the OMI had a diameter of 1.8 mm and length of 8.5 mm and was placed between the roots of the upper second premolar and the first molar. The cortical bone thickness was set to 1 mm. The head part of the OMI was available in 3 sizes: 1 mm, 2 mm, and 3 mm. After a 2 N lateral force was applied to the center of the head part, the stress distribution and magnitude were analyzed using FEA. Results: When the head part of the OMI was friction fitted (tapped into place) into the inserted screw part, the stress was uniformly distributed over the surface where the head part was inserted. The extent of the minimum principal stress suggested that the length of the head part was proportionate with the amount of stress to the cortical bone; the stress varied between 10.84 and 15.33 MPa. Conclusions: These results suggest that the stress level at the cortical bone around the OMI does not have a detrimental influence on physiologic bone remodeling.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.68-72
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• 2007

An 8-year-old, male Shih-tzu dog with clinical signs of hemorrhage from penile orifice and pain on lifting hindlimb was brought to the Veterinary Medicine Teaching Hospital, Chungnam National University. The patient was shown polyuria/polydipsia (PU/PD), more than 10 times per day, and gasterointestinal signs such as intermittent vomiting and melena. On laboratory examination, BUN, creatinine and amylase level were all highly increased. Radiographic and ultrasonographic findings included that both kidneys were abnormal, and both prostates were hyperplastic bilaterally and cysts were presented in parenchyma. Additionally, hyperechoic pancreas and intact urinary bladder were observed from ultrasonographic examination. The dog was diagnosed as pancreatitis, acute renal failure and benign prostatic hyperplasia (BPH). After the appropriate treatment for pancreatitis and acute renal failure, He dog was treated with administration of azasteroid for BPH. On day 71 after azasteroid treatment, good response to the treatment was defined by ultrasonography and clinical signs cured completely.

• Korean Journal of Clinical Pharmacy
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• v.22 no.1
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• pp.21-29
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• 2012

Modern biologics are biotechnology-derived therapeutics, including recombinant therapeutic proteins like monoclonal antibodies, cytokines and tissue growth factors. Although the pharmacokinetics of therapeutic biologics should be evaluated based on the same general principles as small molecules, careful considerations should be given to bioanalytics and pharmacokinetics when designing pharmacokinetic studies of biologics during their drug development, due to their different physicochemical properties compared with small molecules. The aim of this study was to develop a draft guidance on pharmacokinetic studies of therapeutic biologics in clinical studies. All the elements outlined in the current Food and Drug Administration (FDA), European Medicinal Agency (EMEA), and International Conference on Harmonisation (ICH) guidelines and regulations, and the related literatures previously published were searched and evaluated. In this draft guidance, the specific problems related to the pharmacokinetics of therapeutic biologics that need special consideration during drug development process were addressed, and differences in pharmacokinetic characteristics between biologics and small molecules affecting the content of the development programme were presented.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.217-221
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• 2000

Objective : Brainstem hemorrhages usually result in much higher mortality and morbidty than any other intracranial vascular lesions. The purpose of the study is to evaluate the relationship of the radiological classification of the lesions and the clinical outcomes, and to evaluate the value of such classification on the choice of management modality. Method : Thirty seven patients with primary brainstem hemorrhage were managed medically or surgically between Oct. 1995 and Mar. 1998. The lesions were classified as two groups based on radiological findings as follows : Focal subependymal hematoma(group I, n＝7) and diffuse tegmentobasilar hemorrhage(group II, n＝30). The outcomes at discharge were retrospectively reviewed according to such classification. Result : The most common clinical pictures and radiological findings in each group were as followings : 1) Group I : focal compressive lesion which displaces rather than destroys brain tissue. It occurs in a younger age group and causes neurological deficits which are often partially reversible. Operative hematoma evacuation was performed in 43.3%. Their mean improved Glasgow Coma Scale(GCS) score was 4.7. 2) Group II : hypertensive brain stem hemorrhage. It usually causes a diffuse lesion occurring in an older age group and most often associated with profound irreversible neurological deficits which are often fatal. Operative hematoma evacuation was performed in 16.7%. Their mean improved GCS score was 1.4. In both conservatively treated group I and II has no siginificant clinical improvement. Conclusion : Although there is an overlap among them and the size of the group is small, the pathophysiologic classification of this lesion based on clinical features and radiological findings may be useful for decision of treatment method.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.311-315
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• 2014

In this study, we investigated the effect of space plasmas on the floating potential variation of a low-altitude, polar-orbiting satellite using the Langmuir Probe (LP) measurement onboard the STSAT-1 spacecraft. We focused on small potential drops, for which the estimation of plasma density and temperature from LP is available. The floating potential varied according to the variations of plasma density and temperature, similar to the previously reported observations. Most of the potential drops occurred around the nightside auroral region. However, unlike the previous studies where large potential drops were observed with the precipitation of auroral electrons, the potential drops occurred before or after the precipitation of auroral electrons. Statistical analysis shows that the potential drops have good correlation with the temperature increase of cold electrons, which suggests the small potential drops be mainly controlled by the cold ionospheric plasmas.

• Journal of Korean Neurosurgical Society
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• v.58 no.5
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• pp.419-425
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• 2015

Objective : Acute vertebrobasilar artery occlusion (AVBAO) is a devastating disease with a high mortality rate. One of the most important factors affecting favorable clinical outcome is early recanalization. Mechanical thrombectomy is an emerging treatment strategy for achieving a high recanalization rates. However, thrombectomy alone can be insufficient to complete recanalization, especially for acute stroke involving large artery atheromatous disease. The purpose of this study is to investigate the safety and efficacy of mechanical thrombectomy in AVBAO. Methods : Fourteen consecutive patients with AVBAO were treated with mechanical thrombectomy. Additional multimodal treatments were intra-arterial (IA) thrombolysis, balloon angioplasty, or permanent stent placement. Recanalization by thrombectomy alone and multimodal treatments were assessed by the Thrombolysis in Cerebral Infarction (TICI) score. Clinical outcome was determined using the National Institutes of Health Stroke Scale (NIHSS) at 7 days and the modified Rankin Scale (mRS) at 3 months. Results : Thrombectomy alone and multimodal treatments were performed in 10 patients (71.4%) and 4 patients (28.6%), respectively. Successful recanalization (TICI 2b-3) was achieved in 11 (78.6%). Among these 11 patients, 3 (27.3%) underwent multimodal treatment due to underlying atherosclerotic stenosis. Ten (71.4%) of the 14 showed NIHSS score improvement of >10. Overall mortality was 3 (21.4%) of 14. Conclusion : We suggest that mechanical thrombectomy is safe and effective for improving recanalization rates in AVBAO, with low complication rates. Also, in carefully selected patients after the failure of recanalization by thrombectomy alone, additional multimodal treatment such as IA thrombolysis, balloons, or stents can be needed to achieve successful recanalization.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.10
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• pp.881-884
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• 2008

In this study, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) in the composition from 51/49, was deposited on platinum for a metal-ferroelectric-metal structure. From XRD patterns, the 70 nm- and 140 nm-thick PVDF-TrFE films showed the intensity peak of near $20^{\circ}$ connected to a ferroelectric phase. Moreover, the thicker film indicated the higher intensity than thinner one. The difference of the remanent polarization (2Pr) at 0 V is decreased gradually from 10.19 to $5.7{\mu}C/cm^2$ as the thickness decrease from 140 to 70 nm. However, when the thickness decreased to 50 nm, the 2Pr rapidly drop to $1.6{\mu}C/cm^2$ so the minimum critical thickness might be at least 70 nm for device. Both different thickness films, 70 and 140 nm, indicated that the characteristic of current density-voltage was measured for $10^{-6}{\sim}10^{-7}A/cm^2$ below 15 V and the thicker film maintained relatively lower current density than thinner one. From these results, we can expect that the electrical properties for the devices particularly ferroelectric thin film transistor using PVDF-TrFE copolymer were able to be on the trade-off relationship between the remanent polarization with the bias voltage and the leakage current.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.8
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• pp.439-447
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• 2009

Cogeneration system produces power as well as heat recovered from waste heat during power generation process. This system has higher energy efficiency than that of the power plant. In this study the optimal design for the cogeneration system with the increase of the capacity considering life cycle cost(LCC) analysis has been performed in the general facilities such as hotels and hospitals under the assumption of electricity cost of 95 won/kWh, the initial cost of cogeneration system of 1,500,000 won!kW and the value of 0.5${\sim}$1.0 in the ratio of heat to power. The optimal ratio of cogeneration capacity divided by average electricity load of facility was found out more than 0.5 in case of electricity cost with the increase of>30%, and the percentage of $CO_2$ reduction was about 9%. The most important factors in the economic analysis of cogeneration system was found out the electrity cost and the initial cost of cogeneration system. Also the ratio of heat to power at the value of>0.5 was not affected in the economy of cogeneration system, but was very important in the $CO_2$ reduction.

• Journal of Sensor Science and Technology
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• v.16 no.3
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• pp.165-173
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• 2007

A differential floating mass transducer has been developed in Korea for fully implantable middle ear hearing devices (F-IMEHDs). In particular, the performance of a differential floating mass transducer (DFMT) is very important among the parts of the F-IMEHDs because the mechanical vibration generated by DFMT is delivered to the inner ear directly. In this paper, the electrical model is proposed to analyze the DFMT vibration characteristic using the mechanical model of the DFMT. The electrical model enables the simple analysis of DFMT vibration characteristics using a computer program. The proposed electrical model is simulated through PSpice as changing the values of passive elements in the electrical model. To verify the proposed model, the DFMT has been implemented on the basis of the simulated results and the experiment for vibration measurement has been carried out. Through the comparison, it is verified that the proposed model is useful to analyze the vibration characteristics of the DFMT.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.6
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• pp.447-451
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• 2016

In this study, Albizziae Cortex extracts (ACE) have potent effects on adipogenesis and on lipolysis in OP9 cells. There was no cytotoxicity while cells were treated with ACE in designated time intervals, unaffected by various concentrations. In the cells with ACE-treated, increases in fat storage were inhibited, and also confirmed by Oil red O. To understand the underlying mechanism at the molecular level, the effects of ACE were examined on the expression of the genes involved in adipogenesis by using real-time PCR. In this cell model, the mRNA level of adipogenic genes such as peroxisome-proliferator-activated receptors gamma ($PPAR{\gamma}$) and CAAAT/enhancer binding protein alpha ($C/EBP{\alpha}$) were decreased by ACE treatment, comparing with those of control group. Collectively, our data suggest that ACE may have great potential as a novel anti-obesity agent.