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히드록시 프로필 키틴과 키토산의 합성 및 이들의 액정성에 관한 연구
마영대,정승용,정종현,김경희 단국대학교 1998 論文集 Vol.33 No.-
The hydroxypropylated chitin and chitosan were prepared by reaction of alkali chitin and chitosan with propylene oxide (1,2epoxypropane) in hexane as a second dilute solvent at 70℃. The derivatives with different total degree of substitution (DS) and molar substitution (MS) were obtained by adjusting the mole ratio of propylene oxide and NaOH to glucosamine unit or Nacetylglucosamine unit and the reaction pressure. The MS value and the site of substitution were determined by the FTIR and ^1HNMR analysis. The results showed that all the samples are the Oalkylation products, suggesting that the DS values of all the derivatives are less than 2. On the other hand, the observed values of MS for almost all the samples were found to be larger than 2, indicating that propylene oxide molecules became more and more difficult to reach the main cain as the side chain grew. By optical microscopic observation, the derivatives with high MS values, all the which are soluble in water as well as common organic solvents, were found to form both thermotropic and lyotropic phases.
Ma, Seung Hyun,Park, Bo-Young,Yang, Jae Jeong,Jung, En-Joo,Yeo, Yohwan,Whang, Yungi,Chang, Soung-Hoon,Shin, Hai-Rim,Kang, Daehee,Yoo, Keun-Young,Park, Sue Kyung The Korean Society for Preventive Medicine 2012 예방의학회지 Vol.45 No.6
Objectives: Diabetes and obesity each increases mortality, but recent papers have shown that lean Asian persons were at greater risk for mortality than were obese persons. The objective of this study is to determine whether an interaction exists between body mass index (BMI) and diabetes, which can modify the risk of death by cardiovascular disease (CVD). Methods: Subjects who were over 20 years of age, and who had information regarding BMI, past history of diabetes, and fasting blood glucose levels (n=16 048), were selected from the Korea Multi-center Cancer Cohort study participants. By 2008, a total of 1290 participants had died; 251 and 155 had died of CVD and stroke, respectively. The hazard for deaths was calculated with hazard ratio (HR) and 95% confidence interval (95% CI) by Cox proportional hazard model. Results: Compared with the normal population, patients with diabetes were at higher risk for CVD and stroke deaths (HR, 1.84; 95% CI, 1.33 to 2.56; HR, 1.82; 95% CI, 1.20 to 2.76; respectively). Relative to subjects with no diabetes and normal BMI (21 to 22.9 $kg/m^2$), lean subjects with diabetes (BMI <21 $kg/m^2$) had a greater risk for CVD and stroke deaths (HR, 2.83; 95% CI, 1.57 to 5.09; HR, 3.27; 95% CI, 1.58 to 6.76; respectively), while obese subjects with diabetes (BMI ${\geq}25kg/m^2$) had no increased death risk (p-interaction <0.05). This pattern was consistent in sub-populations with no incidence of hypertension. Conclusions: This study suggests that diabetes in lean people is more critical to CVD deaths than it is in obese people.
Korean Epithelial Ovarian Cancer Study (Ko-EVE): Protocols and Interim Report
Ma, Seung Hyun,Kim, Byoung-Gie,Choi, Ji-Yeob,Kim, Tae-Joong,Kim, Yong-Man,Kim, Jae Weon,Kang, Sokbom,Kang, Daehee,Yoo, Keun-Young,Park, Sue K. Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8
Background: There have been few studies of Asian ovarian cancer and benign tumors. The primary aim of this paper was to report the protocol of the Ko-EVE study to examine epidemiological and molecular factors for ovarian cancer and benign neoplasms and to ascertain the major risk factors for ovarian cancer control in Korea. Methods: This case-control study covers incident epithelial ovarian cancers and benign neoplasms, four major centers participating in enrolling incident cases and 3 hospitals enrolling healthy controls among health examinees. Standardized questionnaires were administered by trained interviewers, including sections on socio-demographics characteristics, past medical history, medication usage, family history, lifetime consumption of alcohol and tobacco, diet, physical activity, and reproductive factors for women. Various biological specimens were collected in the biorepository according to the standardized protocol. Annual follow-up for cancer cases and follow-up at the 1st year for benign tumor cases are performing to evaluate treatment effect and progression. Passive follow to see long-term survival will be conducting using record linkage with national data. Results: The total number recruited in 2010-2011 was 246 epithelial ovarian cancer cases, 362 benign epithelial tumors and 345 controls. We are planning to collect subjects for at least 1,500 sets of ovarian cancer, 2,000 benign tumors and 1,500 controls till 2018. Conclusions: The Ko-EVE will provide unique and important data to probe the etiology and natural history of Korean epithelial ovarian cancer. It will be continued by genomic and proteomic epidemiological analyses and future intervention studies for the prevention of ovarian cancer among Koreans.
Eyeball model-based iris center localization for visible image-based eye-gaze tracking systems
Seung-Jin Baek,Kang-A Choi,Chunfei Ma,Young-Hyun Kim,Sung-Jea Ko IEEE 2013 IEEE transactions on consumer electronics Vol.59 No.2
<P>In general, the visible image-based eye-gaze tracking system is heavily dependent on the accuracy of the iris center (IC) localization. In this paper, we propose a novel IC localization method based on the fact that the elliptical shape (ES) of the iris varies according to the rotation of the eyeball. We use the spherical model of the human eyeball and estimate the radius of the iris from the frontal and upright-view image of the eye. By projecting the eyeball rotated in pitch and yaw onto the 2-D plane, a certain number of the ESs of the iris and their corresponding IC locations are generated and registered as a database (DB). Finally, the location of IC is detected by matching the ES of the iris of the input eye image with the ES candidates in the DB. Moreover, combined with facial landmark points-based image rectification, the proposed IC localization method can successfully operate under natural head movement. Experimental results in terms of the IC localization and gaze tracking show that the proposed method achieves superior performance compared with conventional ones.</P>
Ma, Choong Je,Kim, Seung Hyun,Lee, Ki Yong,Oh, Taehwan,Kim, Sun Yeou,Sung, Sang Hyun,Kim, Young Choong John Wiley Sons, Ltd. 2009 Phytotherapy research Vol.23 No.11
<P>It was reported previously that ESP-102, a combined extract of Angelica gigas, Saururus chinensis and Schizandra chinensis, significantly improved scopolamine-induced memory impairment in mice and protected primary cultured rat cortical cells against glutamate-induced toxicity. To corroborate this effect, the action patterns of ESP-102 were elucidated using the same in vitro system. ESP-102 decreased the cellular calcium concentration increased by glutamate, and inhibited the subsequent overproduction of cellular nitric oxide and reactive oxygen species to the level of control cells. It also preserved cellular activities of antioxidative enzymes such as superoxide dismutase, glutathione peroxidase and glutathione reductase reduced in the glutamate-injured neuronal cells. While a loss of mitochondrial membrane potential was observed in glutamate treated cells, the mitochondrial membrane potential was maintained by ESP-102. These results support that the actual mechanism of neuroprotective activity of ESP-102 against glutamate-induced oxidative stress might be its antioxidative activity. Copyright © 2009 John Wiley & Sons, Ltd.</P>
( Seung Hwan Kwon ),( Shi Xun Ma ),( Hyun Joong Joo ),( Seok Yong Lee ),( Choon Gon Jang ) 한국응용약물학회 2013 Biomolecules & Therapeutics(구 응용약물학회지) Vol.21 No.6
Eucommia ulmoides Oliv. Bark (EUE) is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia as well as to promote longevity. In this study, we tested the effects of EUE aqueous extract in graded doses to protect and enhance cognition in scopolamine-induced learning and memory impairments in mice. EUE signifi cantly improved the impairment of short-term or working memory induced by scopolamine in the Y-maze and signifi cantly reversed learning and memory defi cits in mice as measured by the passive avoidance and Morris water maze tests. One day after the last trial session of the Morris water maze test (probe trial session), EUE dramatically increased the latency time in the target quadrant in a dose-dependent manner. Furthermore, EUE signifi cantly inhibited acetylcholinesterase (AChE) and thiobarbituric acid reactive substance (TBARS) activities in the hippocampus and frontal cortex in a dose-dependent manner. EUE also markedly increased brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP element binding protein (CREB) in the hippocampus of scopolamine-induced mice. Based on these fi ndings, we suggest that EUE may be useful for the treatment of cognitive defi cits, and that the benefi cial effects of EUE are mediated, in part, by cholinergic signaling enhancement and/or protection.
( Seung Hwan Kwon ),( Shi Xun Ma ),( Ji Young Hwang ),( Yong Hyun Ko ),( Ji Yeon Seo ),( Bo Ram Lee ),( Seok Yong Lee ),( Choon Gon Jang ) 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.3
In the present study, we investigated the anti-inflammatory properties of Eucommia ulmoides Oliv. Bark. (EUE) in lipopolysaccharide (LPS)-stimulated microglial BV-2 cells and found that EUE inhibited LPS-mediated up-regulation of pro-inflammatory response factors. In addition, EUE inhibited the elevated production of pro-inflammatory cytokines, mediators, and reactive oxygen species (ROS) in LPS-stimulated BV-2 microglial cells. Subsequent mechanistic studies revealed that EUE suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), phosphoinositide-3-kinase (PI3K)/Akt, glycogen synthase kinase-3β (GSK-3β), and their downstream transcription factor, nuclear factor-kappa B (NF-κB). EUE also blocked the nuclear translocation of NF-κB and inhibited its binding to DNA. We next demonstrated that EUE induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression. We determined that the significant up-regulation of HO-1 expression by EUE was a consequence of Nrf2 nuclear translocation; furthermore, EUE increased the DNA binding of Nrf2. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, blocked the ability of EUE to inhibit NO and PGE2 production, indicating the vital role of HO-1. Overall, our results indicate that EUE inhibits pro-inflammatory responses by modulating MAPKs, PI3K/Akt, and GSK-3β, consequently suppressing NF-κB activation and inducing Nrf2-dependent HO-1 activation.