Regulation of Systemic Energy Homeostasis by Peripheral Serotonin

Namkung, Jun,Oh, Chang-Myung,Park, Sangkyu,Kim, Hail Association for Research of MPS and Rare Diseases 2016 Journal of mucopolysaccharidosis and rare disease Vol.2 No.2

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. Serotonin is among those traditional pharmacological targets for anti-obesity treatment because central 5-HT functions as an anorexigenic neurotransmitter in the brain. Thus, there have been many trials aimed at increasing the activity of 5-HT in the central nervous system, and some of the developed methods are already used in the clinical setting as anti-obesity drugs. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Pharmacological inhibition of 5-HT synthesis leads to inhibition of lipogenesis in epididymal white adipose tissue (WAT), induction of browning in inguinal WAT and activation of adaptive thermogenesis in brown adipose tissue (BAT). Fat specific Tph1 knock-out (Tph1 FKO) mice exhibit similar phenotypes as mice with pharmacological inhibition of 5-HT synthesis, suggesting the localized effects of 5-HT in adipose tissues. In addition, Htr3a KO mice exhibit increased energy expenditure in BAT and Htr2a KO mice exhibit the decreased lipid accumulation in WAT. These data suggest the clinical significance of the peripheral serotonergic system as a new therapeutic target for anti-obesity treatment.

Expression of alkA and ada Genes Involved in Adaptive Response

Namkung, Rock,Choe, Soo Y,Lee, Hee W,Park, Sang D 한국유전학회 1988 Genes & Genomics Vol.10 No.4

The regulation of the gene expression was investigated using the cloned alkA and ada genes. The alkA and ada promoters were fused with lac Z structural region without frame shift in reading frame by in vitro gene fusion technique. The induced β-galactosidase activities were examined. The activities of β-galactosidase expressed from the fused genes were highly induced when treated with methylating agents, but the nonalkylating agents did not induce the β-galactosidase activities. The inducible pattern did not observe in PJ 1 cells even after treatment with the methylating agents. These results indicate that the alkA and ada gene would not be expressed in the absence of Ada protein.

Blending effect of sewage sludge and woody biomass into coal on combustion and ash agglomeration behavior

Namkung, Hueon,Lee, Young-Joo,Park, Ju-Hyoung,Song, Gyu-Seob,Choi, Jong Won,Choi, Young-Chan,Park, Se-Joon,Kim, Joeng-Geun Elsevier 2018 Fuel Vol.225 No.-

<P><B>Abstract</B></P> <P>The co-combustion of sewage sludge and woody biomass is a key issue in coal power plants. Different combustion and ash behaviors of sewage sludge and woody biomass cause unpredictable operating concerns. In this study, the combustion and ash agglomeration behavior of blended fuel of sewage sludge and woody biomass (BSW) were investigated while coal co-combusted with it. Thermogravimetric analysis (TGA) revealed that adding a high amount of BSW into the coal lowered volatilization, ignition, and burn-out temperature. The char combustion reactivity of coal differed from that of BSW. The shrinking core model (SCM) and volumetric reaction model (VRM) were used to fit the char combustion reactivity of coal and BSW. In the case of ash agglomeration behavior, BSW addition led to increasing particle agglomeration at fouling temperatures. In particular, phosphorus composition influenced particle growth, which was verified using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) analysis. Furthermore, the ash mixture ratio of BSW and coal changed the intensity of the phosphorus-bearing mineral phase from X-ray diffraction (XRD) analysis, and finally influenced the melting temperature of the ash.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The combustion and ash agglomeration characteristics of coal and BSW mixture were investigated. </LI> <LI> Addition of BSW into the coal lowered the combustion temperature profiles during non-isothermal heating conditions. </LI> <LI> Carbon and reagent gas reaction occurred on exterior and interior of the particle during char combustion. </LI> <LI> BSW containing high phosphorus contents made a high agglomeration tendency and low melting mineral phase. </LI> </UL> </P>

Multilateral approaches for investigation of particle stickiness of coal ash at low temperature fouling conditions

Namkung, Hueon,Kim, Hyung-Taek,Wang, Fuchen,Lin, Kuangfei,Yu, Guangsuo Springer-Verlag 2017 Korean Journal of Chemical Engineering Vol.34 No.12

<P>Particle stickiness is a key parameter for increasing ash deposition in gasification process. We conducted multilateral investigations to evaluate particle stickiness of coal ash at low temperature fouling conditions through Watt and Fereday's viscosity model, dilatometry (DIL) and laser flash apparatus (LFA) technique. Seventeen coals were employed for ash deposition experiments under gasification condition through drop tube furnace (DTF). The low viscosity not only led to increasing ash deposition behavior, but also increasing the particle size of deposited ash. From DIL analysis, the ash sintering behavior increased with increasing temperature due to increase of particle stickiness. The high amount of Fe2O3, CaO and MgO components resulted in low sintering temperature and high reduction of physical length. Through LFA analysis, the thermal conductivity increased with increasing temperature, because of increasing particle stickiness. In addition, its value was correlated with the propensity of common fouling indices.</P>

Peripheral Serotonin: a New Player in Systemic Energy Homeostasis

Namkung, Jun,Kim, Hail,Park, Sangkyu Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.12

Whole body energy balance is achieved through the coordinated regulation of energy intake and energy expenditure in various tissues including liver, muscle and adipose tissues. A positive energy imbalance by excessive energy intake or insufficient energy expenditure results in obesity and related metabolic diseases. Although there have been many obesity treatment trials aimed at the reduction of energy intake, these strategies have achieved only limited success because of their associated adverse effects. An ancient neurotransmitter, serotonin is among those traditional pharmacological targets for anti-obesity treatment because it exhibits strong anorectic effect in the brain. However, recent studies suggest the new functions of peripheral serotonin in energy homeostasis ranging from the endocrine regulation by gut-derived serotonin to the autocrine/paracrine regulation by adipocyte-derived serotonin. Here, we discuss the role of serotonin in the regulation of energy homeostasis and introduce peripheral serotonin as a possible target for anti-obesity treatment.

Understanding non-classical correlation using optical hybrid states in noisy quantum channels

Namkung, Min,Kwon, Younghun IOP 2018 JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL Vol.51 No.45

<P>In this article we investigate the non-classical correlation in a macroscopic physical system. As a tool, we consider an optical hybrid state that is a micro–macro entangled state. Our strategy is to study the behavior of non-classical correlation in an optical hybrid state that may go through noisy channels. We study the violation of two inequalities, which are the CHSH-inequality and the (generalized) CHSH-like-inequality, as measures of non-classical correlation. First, we find that when on/off or parity measurements are used for the side of the coherent state in an optical hybrid state, the violation of the CHSH-inequality is the same as that of the (generalized) CHSH-like-inequality. Second, we see that each measurement provides a different value of violation of (generalized) CHSH-inequality when it is an optical hybrid state that goes through noisy channels. A suprising result is that the on/off measurement can provide a violation of CHSH-inequality (or (generalized) CHSH-like-inequality) for an optical hybrid state with any amount of colored noise. This implies that colored noise cannot break the non-classical correlation in an optical hybrid state.</P>

Group-Specific Component(Gc) Polymophism in Korean : Ⅰ. An Investigation on the Phenotypic Distribution of Jeju-do Population Ⅰ. 濟州島人集團에서의 Gc 表現型의 分布에 대하여

Namkung, Yong,Lee, Chung-Choo,Oh, Moon-You 제주대학교 1980 논문집 Vol.12 No.-

The polymorphism of the Group-Specific Component(Gc) was studied in serum samples from Jeju-do population of Korea using thin layered (1mm) polyacrylamide gel isoelectric focusing (PAGIF). Six common subtypes, 1F-1F, 1F-1S, 1S-1S, 1S-2, 1F-S and 2-2, were found. The allele frequencies were for Gc 1F;0.518, for 1S;0.312 and for Gc 2;0. 170, respectively. The heterogeneity rate was 0.5065.

One New Species of the Genus Galloisiana (Notoptera: Grylloblattidae) from Korea

Namkung, Joon(南宮焌) 한국동물분류학회 1986 Animal Systematics, Evolution and Diversity Vol.2 No.2

A New Species of Cave Dwelling Grylloblattoidea (Grylloblattidae) from Korea

Namkung, Joon 한국곤충학회 1974 Korean journal of entomology Vol.4 No.1

원시무시곤충으로 주목되고 있는 Grylloblattoidea는 1914년 E.M. Walker가 최초로 발표한 이래, 북미각지에서 7종.2아종, 일본에서 5종, Siberia에서 1종이 기재된 바 있으나 우리나라에서는 아직껏 밝혀진 바가 없다. 저자는 1966년 6월 보한강상류인 정선군 비룡동굴에서 완전한 1성웅을 채집한 바 있어 여기에 Gallcisiana biryongensis(비룡갈르와 벌레)로 명명 기재한다. 본종은 다양색.무안.체장 34mm로 기지의 어느 것보다도 대형종이다. 대체적구조는 일본산 Galloisiana nipponensis에 닮으나 제10복배판 끝 Supra-anal plate가 둔만년필촉과 같이 무듸게 되며, 북미종과는 부절욕반이 있음에서 외관상으로도 분명히 구별된다. 본종의 중요 표징은 다음과 같다. (1) 두부는 편본하고 폭이 약간 넓은 원형으로 두개선이 명료하고, 복안은 퇴화되었으나 강대한 안부강모가 나있다. (2) 전흉배는 저대한 정방형, 중흉배는 전변이 좁은 제형, 후흉배는 전변이 약천 좁은 제형으로 각 측연과 중앙부에 불규칙한 강모가 나있다. (3) 복배판은 제4, 5절이 최대이며, 각 절의 하변에 8개, 측연에 1개씩의 강모가 정열하며 제10배판 끝은 순한 만년필촉 꼴로 일견 2분 된 듯한 감을 준다. (4) 미모는 9절로 되며, 각 말단부에 3,4재의 장강모가 나 있고, 미세 투명한 긴 감각모가 보인다. (5) 보각은 완장하며 부절욕반이 명료하다. (6) 웅생식기관은 복잡한 구조를 갖추며, 복지는 좌우비대칭으로 좌지는 폭광인 ?꼴이고, 우지는 장삼각형으로 기부끝에 투명한 단추꼴 돌기가 보인다. (7) 대형의 주름진 반전낭이 우음경엽부에서 돌출하고 있으며, 비교적 완장한 주음경과 부음경이 보인다.

Allocation in Multi-way Stratification by Linear Programing

NamKung, Pyong,Choi, Jae-Hyuk 한국통계학회 2006 Communications for statistical applications and me Vol.13 No.2

Winkler (1990, 2001), Sitter and Skinner (1994), Wilson and Sitter (2002) present a method which applies linear programing to designing surveys with multi-way stratification, primarily in situation where the desired sample size is less than or only slightly larger than the total number of stratification cells. A comparison is made with existing methods both by illustrating the sampling schemes generated for specific examples, by evaluating sample mean, variance estimation, and mean squared errors, and by simulating sample mean for all methods. The computations required can, however, increase rapidly as the number of cells in the multi-way classification increase. In this article their approach is applied to multi-way stratification using real data.