Comparison of trophic factors changes in the hippocampal CA1 region between the young and adult gerbil induced by transient cerebral ischemia.

Yan, Bing Chun,Park, Joon Ha,Kim, Sung Koo,Choi, Jung Hoon,Lee, Choong Hyun,Yoo, Ki-Yeon,Kwon, Young-Geun,Kim, Young-Myeong,Kim, Jong-Dai,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2012 Cellular and molecular neurobiology Vol.32 No.8

<P>In the present study, we investigated neuronal death/damage in the gerbil hippocampal CA1 region (CA1) and compared changes in some trophic factors, such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and vascular endothelial growth factor (VEGF), in the CA1 between the adult and young gerbils after 5 min of transient cerebral ischemia. Most of pyramidal neurons (89%) were damaged 4 days after ischemia-reperfusion (I-R) in the adult; however, in the young, about 59% of pyramidal neurons were damaged 7 days after I-R. The immunoreactivity and levels of BDNF and VEGF, not GDNF, in the CA1 of the normal young were lower than those in the normal adult. Four days after I-R in the adult group, the immunoreactivity and levels of BDNF and VEGF were distinctively decreased, and the immunoreactivity and level of GDNF were increased. However, in the young group, all of their immunoreactivities and levels were much higher than those in the normal young group. From 7 days after I-R, all the immunoreactivities and levels were apparently decreased compared to those of the normal adult and young. In brief, we confirmed our recent finding: more delayed and less neuronal death occurred in the young following I-R, and we newly found that the immunoreactivities of trophic factors, such as BDNF, GDNF, and VEGF, in the stratum pyramidale of the CA1 in the young gerbil were much higher than those in the adult gerbil 4 days after transient cerebral ischemia.</P>

A Study on Bias Effect on Model Selection Criteria in Graphical Lasso

Young-Geun Choi,Seyoung Jeong,유동현 계명대학교 자연과학연구소 2018 Quantitative Bio-Science Vol.37 No.2

Graphical lasso is one of the most popular methods to estimate a sparse precision matrix, which is an inverse of a covariance matrix. The objective function of graphical lasso imposes an 1 A study on Bias Effect on Model Selection Criteria in Graphical Lasso Young-Geun Choi1, Seyoung Jeong2, Donghyeon Yu2* 1SK Telecom, Seoul 04539, Korea 2Department of Statistics, Inha University, Incheon 22212, Korea (Received Oct 8, 2018; Revised Nov 4, 2018; Accepted Nov 12, 2018) Abstract Graphical lasso is one of the most popular methods to estimate a sparse precision matrix, which is an inverse of a covariance matrix. The objective function of graphical lasso imposes an ℓ-penalty on the (vectorized) precision matrix, where a tuning parameter controls the strength of the penalization. The selection of the tuning parameter is practically and theoretically important since the performance of the estimation depends on an appropriate choice of tuning parameter. While information criteria (e.g. AIC, BIC, or extended BIC) have been widely used, they require an asymptotically unbiased estimator to select optimal tuning parameter. Thus, the biasedness of the ℓ- regularized estimate in the graphical lasso may lead to a suboptimal tuning. In this paper, we propose a two-staged bias-correction procedure for the graphical lasso, where the first stage runs the usual graphical lasso and the second stage reruns the procedure with an additional constraint that zero estimates at the first stage remain zero

Agrobacterium을 이용한 고추의 형질전환체계개발

최근원,박영두,박승국,전영주,유일웅,김인태,백운돈 경희대학교 생명자원과학연구원 1997 硏究論文集 Vol.18 No.-

본 실험은 고추의 형질전환체 선발을 위한 최소의 항생제농도를 결정하고 그 결과를 이용하여 형질전환체를 유기하고 효율을 최대화하기 위하여 수행한 바 그 결과는 다음과 같다. 1. 항생제 감응성 검정결과 kanamycin 40㎎/ℓ와 hygromycin 20 ㎎/ℓ에서 신초형성이 완전히 억제되었다. 2. Agrobacterium 제거에 사용되는 carbenicillin과 cefotaxime 처리시 재분화에 아무런 영향을 미치지 않았으며 cefotaxime 200㎎/ℓ 처리에서는 무처리구보다 신초형성이 더 활발하였다. 3. 회복친인 135Q와 276F에서는 형질 전환시 높은 재분화율을 보였으나 형질전환율은 각각 10%와 11.1%의 낮은 빈도를 보였다. 4. 재분화된 신초들을 대상으로 histochemical GUS assay를 실시한 결과 부분적으로 푸른발색이 확인되었다. 5. GUS활성을 보인 신초들에 대한 NPTⅡprimer를 이용한 PCR검정에서 NPTⅡ 유전자의 존재가 확인되었다. A transformation system using Agrobacterium tumefaciens was developed with different genotypes of hot peppers (Capsicum annuum). Four antibiotics commonly used in Agrobacterium-mediated transformation were tested for their effects on shoot regeneration. Shoot induction was completely inhibited by kanamycin at 40㎎/ℓ and hygromycin at 20㎎/ℓ or higher, but not by carbenicillin and cefotaxime. Cotyledon explants of hot peppers were cocultivated with Agrobacterium turnefaciens LBA4404 which carries a binary. vector pBI121 harboring the neomycin phosphotransferase, type Ⅱ (NPT Ⅱ) gene and β-glucuronidase (GUS) gene. For selection of transformed cells, 40㎎/ℓ kanamycin were used because the sensitivity test showed that 40㎎/ℓ kanamycin completely inhibited shoot induction from nontransformed cells. Histochemical GUS assay showed the presence of the GUS gene and PCR analysis confirmed the NP TⅡ gene was integrated. Transformation frequency was about 10.0% and 11.1% of total regenerants from 135Q and 276F, respectively.

PZT께 압전 세라믹스의 제조 및 기계적 특성에 관한 연구

崔永根,權鍾完 慶一大學校 1993 論文集 Vol.9 No.1

Densification behavior, microstructural evolution and mechanical properties of hot-pressed specimens using PZT ceramics with PbO additive were studied, and bulk density, microstructure, mechanical properties were investigated for sintering time. Fracture toughness of the spections containing 1mol% PbO was increased as the hot-pressing temperature up to 1080℃ and maximum value was 1.60MN/m??, while fracture toughness of the specimens containing 2mol% PbO was decreased. The enhanced fracture toughness by PbO is probably due to the crack deflection along the boundaries of the elongated grains. Vicker's hardness of the specimens was in the range of 270-320Kgf/mm² and was decreased due to the incrasing of pore according to PbO addition. As the sintering time becomes longer, fracture toughness was gradually decreased for the the increasing of grain size and vicker's hardness was shown the linear increasing lue to increase of density.

남북상사중재위원회 운영상의 문제점과 활성화방안

최석범,박근식,김태환,김재학,박선영 한국중재학회 2007 중재연구 Vol.17 No.1

The commercial relationship between South and North Korea is defined under the concept of economic relation and cooperation. To resolve any dispute that can arise from the trade and investment relations between South and North Korea, 'Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea' came into force in August 2003. Commercial Arbitration Committee of South-North Korea will be organized as the member lists of the committee were exchanged in July 2006 between South and North Korea. This committee must become a central system to settle the trade and investment disputes between South and North Korea. North Korea's Foreign Economic Arbitration Act was enacted to provide the foreign investors with the safe measures in their investments such as dispute resolution. But this Act can not dispute the trade and investment disputes between South and North Korea. The purpose of this paper is to contribute to the activation of arbitration between South and North Korea by studying Commercial Arbitration Committee of South-North Korea introduced by Agreement on the Procedures to Resolve Commercial Arbitration of South-North Korea and Agreement on the Construction and Operation of Commercial Arbitration Committee of South-North Korea and finding the problems and solutions of Commercial Arbitration Committee of South-North Korea.

저 유전상수 시클로헥산계 플라즈마 고분자 박막의 특성

최자영,권영춘,여상학,정동근 성균관대학교 기초과학연구소 1999 論文集 Vol.50 No.-

In this work, we report on the investigation of the properties of cyclohexane-based plasma polymers (CHexPP) as functions of the deposition pressure and the plasma power. As the deposition pressure was decreased from 2 torr to 0.2 ton with a fixed plasma power of 60W, k value of the CHexPP thin film increased from 2.42 to 3.24. CHexPP thin films deposited at lower deposition pressure showed very good thermal stability, even the one deposited at 0.2 torn was stable up to 400℃. As the plasma power was increased from 10W to 90W with a fixed deposition pressure of 0.2 ton, k value increased from 2.61 to 3.39. The CHexPP thin film deposited at 90W were stable up to 450℃. All the deposited films were insulating. Under applied fields less than 1 MV/cm, leakage current densities were less than 10^-7 A/㎠.

선형유도전자펌프내의 자기유체 유동에 관한 수치적 연구

최훈기,유근종,박태봉,은재정,장남영 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

Numerical analysis is performed for magnetic and MHD flow fields in Electro-Magnetic(EM) pump. A finite volume method is applied to solve magnetic field governing equations and the Navier-Stokes equations. Vector and scalar potential methods are adopted to obtain the electric and magnetic fields and the resulting Lorentz force in solving Maxwell equations. The magnetic field and velocity distributions are found to be influenced by the magnitude of the Reynolds number and the phase of applied electric current. Computational results indicate that the magnetic flux distribution with changing phase of electric current is characterized by a pair of counter-rotating closed loops. The velocity distribution of the flow field is influenced on the intensity of Lorentz force.

한번의 간질발작 후 혈청 Neuron-Specific Enolase 농도 변화

최승호,박영춘,이장준,임정근,김지언,이상도 啓明大學校 醫科大學 1999 계명의대학술지 Vol.18 No.4

An increase in neuron-specific enolase (NSE) levels in serum and CSF has been shown to be an useful marker of brain damage after stroke, global ischemia, and coma. We report the changes of serum NSE levels after seizure attacks in epileptic patients compared with the levels in normal controls and epileptic patients without seizure attack at least 7 days (epileptic controls). Twenty-four seizures were included in this study. Blood was drawn within 1 hour, at 12 hour, 24 hour, and 48 hour after seizure attack. Serum NSE levels were measured with radioimmunoassay. The mean NSE levels for normal controls and epileptic controls were 6.94 ng/ml and 7.46 ng/ml, respectively. There were significant increase in level of serum NSE measured within 1 hour after seizure attack in epileptics compared with the level in normal controls (15.10ng/ml versus 6.94ng/ml, p<0.05) and epileptic controls (15.10ng/ml versus 7.46ng/ml, p<0.05). Serum NSE measured at 12 hours after seizure also increased compared with normal controls (12.32ng/ml versus 6.94ng/ml, p<0.05) and epileptic controls (12.43ng/ml versus 7.46ng/ml, p<0.05). Between normal controls and epileptic controls, there were no significant difference in serum NSE levels. We conclude that serum NSE level was elevated in epileptic patients who had seizure attack within 12 hours. Serum NSE levels can be useful marker for seizure within 12 hours after onser. The elevated serum NSE level after single seizure attack may suggest that the brain was injured in single seizure.

딸기에 있어서 뿌리썩이 線? (Pratylenchus vulnus) 防除를 위한 土壤 燻蒸劑 處理 ?果에 關한 硏究

崔永然,金東根 COLLEGE OF AGRICULTURE KYUNGPOOK NATIONAL UNIVERSI 1984 慶北大農學誌 Vol.2 No.-

In order to control the root-lesion nematode, Pratylenchus vulnus on strawberry, the effects of six soil fumigants; Cylone, Dowfume MC-2, Di-Trapex, D-D, Telone C-17 and Telone Ⅱ, were evaluated in the farmer's field in 1982 and 1983 in Korea. The number of nematodes were reduced in plots treated with fumigants and the number of leaves and total fresh weight of strawberry were superior to untreated control plots. The treatments of Dowfume Mc-2 at 50㎏/10a and Telone C-17 at 10ℓ/10a increased the yields of strawberry by 38 and 26%, respectively, compared with untreated control plots in 1982. In 1983, the number of nematodes were maintained at considerably low on 180 days after applications. However, on 270 days after the fumigants applications, the number of nematodes in treated plots resumed the similar levels as that before the treatment of chemicals. These values were less than those of untreated control plots investigated on 270 days after. The treatments of Cylone at 30ℓ/10a and Di-Trapex at 30ℓ/10a gave the best results, with increases in yield of 21 and 16%, respectively, compared with untreated control plots. The treatments of Dowfume MC-2 at 50㎏/10a, D-D at 50ℓ/10a, Telone C-17 at 10ℓ/10a and Telone Ⅱ at 8.4ℓ/10a increased the yields by 14, 13, 12 and 10%, respectively.

기제와 피부투과촉진제가 아포모르핀의 피부투과에 미치는 영향

최영근,최옥,김건남,박은석,지상철 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

In order to evaluate the effects of vehicles and penetration enhancers on skin permeation of apomorphine, the skin permeation rates of apomorphine from vehicles of different composition were determined using Franz diffusion cells fitted with excised rat skins. Solubility of apomorphine in various solvents was investigated to select a vehicle suitable for the percutaneous absorption of apomorphine. The solvents used were propylene glycol (PG), Transcutol^??, Labrasol^??, Labrafac hydro WL^??, Labrafil WL 2609 BS^?? and isopropyl alcohol. Even though permeation rates of apomorphine from each vehicle were low (0.08-0.36㎍/㎠/hr), the combination of PG and Labrafac^?? increased it significantly. The permeation rates of apomophine from PG/Labrafac^?? mixtures increased as the volume fraction of PG in the mixture increased. The maximum permeation rate of 18㎍/㎠/hr was achieved at 30% of PG, which decreased with further increase of PG fraction. A series of fatty acids, alcohols and monoterpenes were employed as penetration enhancers. Incorporation of each enhancer in the PG/Labrafac^?? (30:70) mixture at the level of 10% improved the skin permeation significantly. The highest permeation rate, 117㎍/㎠/hr, was attained with myristic acid.