Differences in the relationship between traumatic experiences, self-esteem, negative cognition, and Internet addiction symptoms among North Korean adolescent defectors and South Korean adolescents: A preliminary study

Park, Subin,Lee, Yeeun,Jun, Jin Yong Elsevier/North Holland Biomedical Press 2017 Psychiatry research Vol.257 No.-

<P><B>Abstract</B></P> <P>North Korean adolescent defectors experience adaptation difficulties along with a wide range of psychosocial problems, but no study has yet examined their Internet addiction symptoms. We compared early traumatic experiences, self-esteem, negative cognition, and Internet addiction symptoms, as well as the relationships between these variables, between North Korean adolescent defectors and South Korean adolescents. Fifty-six North Korean adolescent defectors and 112 age- and sex- matched South Korean adolescents participated. The analyses examined the relationship between traumatic experiences and Internet addiction symptoms, with negative automatic thoughts or low self-esteem as mediators of these relations. North Korean adolescent defectors tended to have higher levels of negative automatic thoughts and more severe Internet addiction symptoms, as well as better self-esteem, than did South Korean adolescents. Furthermore, only among North Korean adolescent defectors, traumatic experiences were positively associated with Internet addition symptoms via increasing negative automatic thoughts. North Korean adolescent defectors are more susceptible to Internet addiction, negative cognitions, and early traumatic experiences compared to South Korean adolescents. However, the cross-sectional design of this study precludes consideration of the causality of these relationships. Interventions aiming to correct negative cognitions and increase self-esteem may be helpful for North Korean adolescent defectors with problematic Internet use.</P> <P><B>Highlights</B></P> <P> <UL> <LI> North Korean adolescent defectors had higher trauma and Internet addiction (IA). </LI> <LI> North Korean defectors also had greater self-esteem and negative automatic thoughts. </LI> <LI> Self-esteem and negative thoughts were mediators in the relation of trauma and IA. </LI> <LI> Country of origin (North vs. South Korea) moderated the mediating effects. </LI> </UL> </P>

The neuroprotective effect of eupatilin against ischemia/reperfusion-induced delayed neuronal damage in mice

Cai, M.,Phan, P.T.T.,Hong, J.G.,Kim, D.H.,Kim, J.M.,Park, S.J.,Liu, X.,Han, J.E.,Park, H.,Choi, J.W.,Ryu, J.H. North-Holland ; Elsevier Science Ltd 2012 european journal of pharmacology Vol.689 No.1

Eupatilin, a pharmacologically active flavone derived from the Artemisia plant species, has been reported to have anti-oxidant, anti-inflammatory, anti-allergic, and anti-tumor activities. In the present study, we investigated whether eupatilin exhibits neuroprotective activities against ischemia/reperfusion-induced delayed neuronal injury in mice. Transient global cerebral ischemia was induced in mice by bilateral common carotid artery occlusion (BCCAO) for 15min followed by reperfusion for 4 days. Eupatilin (1, 3, or 10mg/kg, p.o.) was administered immediately after the reperfusion. Histochemical studies showed that eupatilin (10mg/kg) increased the number of viable cells detected by Nissl staining and decreased the number of degenerating neuronal cells detected by Fluoro-Jade B staining in the hippocampal CA1 region. Western blotting indicated that eupatilin further increased the level of Akt phosphorylation at 8h after BCCAO. Furthermore, wortmannin, a phosphatidylinositol 3-kinase inhibitor, attenuated the eupatilin-induced increase of Akt phosphorylation. In addition, wortmannin completely reversed the eupatilin-induced neuroprotective effects observed at 4 days after reperfusion. These findings suggest that eupatilin is a promising therapeutic agent against global cerebral ischemia-induced neuronal damage and that its neuroprotective effects may be mediated in part by increased Akt phosphorylation.

Improvement in operational characteristics of KEPCO's line-commutation-type superconducting hybrid fault current limiter

Yim, S.W.,Park, B.C.,Jeong, Y.T.,Kim, Y.J.,Yang, S.E.,Kim, W.S.,Kim, H.R.,Du, H.I. North-Holland 2013 Physica. C, Superconductivity Vol.484 No.-

A 22.9kV class hybrid fault current limiter (FCL) developed by Korea Electric Power Corporation and LS Industrial Systems in 2006 operates using the line commutation mechanism and begins to limit the fault current after the first half-cycle. The first peak of the fault current is available for protective coordination in the power system. However, it also produces a large electromagnetic force and imposes a huge stress on power facilities such as the main transformer and gas-insulated switchgear. In this study, we improved the operational characteristics of the hybrid FCL in order to reduce the first peak of the fault current. While maintaining the structure of the hybrid FCL system, we developed a superconducting module that detects and limits the fault current during the first half-cycle. To maintain the protective coordination capacity, the hybrid FCL was designed to reduce the first peak value of the fault current by up to approximately 30%. The superconducting module was also designed to produce a minimum AC loss, generating a small, uniform magnetic field distribution during normal operation. Performance tests confirmed that when applied to the hybrid FCL, the superconducting module showed successful current limiting operation without any damage.

Binding properties of a nitrogen atom onto an anionic golden fullerene Au₁₆^-

Kim, G.,Kang, S.H.,Lim, C.y.,Kwon, Y.K. North Holland ; Elsevier Science Ltd 2012 Chemical physics letters Vol.545 No.-

Using density functional theory, we examine the effects of a nitrogen atom adsorbed onto an anionic golden cage (Au<SUB>16</SUB><SUP>-</SUP>) on the properties of the nanocage. For the exohedral adsorption that is more stable than the endohedral doping, the bridge and hollow sites have larger binding energies than the atop sites by ~1eV. When the N atom is adsorbed on the cage, electrons are transferred to nitrogen from Au<SUB>16</SUB><SUP>-</SUP>. The nitrogen atom may move thermally from the exterior to the interior through a bridge site. In infrared spectra, exohedral doping causes greater intensities at higher frequencies than endohedral doping.

Spectroscopic identification and conversion rate of gaseous guest-loaded hydroquinone clathrates

Lee, J.W.,Choi, K.J.,Lee, Y.,Yoon, J.H. North Holland ; Elsevier Science Ltd 2012 Chemical physics letters Vol.528 No.-

The formation of hydroquinone clathrates with CO<SUB>2</SUB>, CH<SUB>4</SUB>, N<SUB>2</SUB>, and H<SUB>2</SUB> was investigated using X-ray diffraction, Raman spectroscopy, and solid-state <SUP>13</SUP>C NMR spectroscopy. Of the hydroquinones prepared at 5.0MPa, the CH<SUB>4</SUB>- and CO<SUB>2</SUB>-loaded hydroquinones show complete conversion to β-form hydroquinone clathrates while the N<SUB>2</SUB>-loaded hydroquinone shows only partial conversion; there is no indication of the formation of hydroquinone clathrate with H<SUB>2</SUB>. The CO<SUB>2</SUB>-loaded hydroquinone is fully converted to the β-form hydroquinone clathrate even at 1.0MPa. Solid-state <SUP>13</SUP>C NMR measurements of the hydroquinone clathrate samples prepared at different pressures reveal that the conversion rate for the formation of clathrate compounds from CH<SUB>4</SUB> and N<SUB>2</SUB> decreases with decreasing pressure.

Measurement and CFD calculation of spacer loss coefficient for a tight-lattice fuel bundle

In, W.K.,Shin, C.H.,Kwack, Y.K.,Lee, C.Y. North-Holland Pub. Co 2015 Nuclear engineering and design Vol.284 No.-

An experiment and computational fluid dynamics (CFD) analysis were performed to evaluate the pressure drop in a spacer grid for a dual-cooled annular fuel (DCAF) bundle. The DCAF bundle for the Korean optimum power reactor (OPR1000) is a 12x12 tight-lattice rod array with a pitch-to-diameter ratio of 1.08 owing to a larger outer diameter of the annular fuel rod. An experiment was conducted to measure the pressure drop in spacer grid for the DCAF bundle. The test bundle is a full-size 12x12 rod bundle with 11 spacer grid. The test condition covers a Reynolds number range of 2x10<SUP>4</SUP>-2x10<SUP>5</SUP> by changing the temperature and flow rate of water. A CFD analysis was also performed to predict the pressure drop through a spacer grid using the full-size and partial bundle models. The pressure drop and loss coefficient of a spacer grid were predicted and compared with the experimental results. The CFD predictions of spacer pressure drop and loss coefficient agree with the measured values within 8%. The spacer loss coefficient for the DCAF bundle is estimated to be approximately 1.50 at a nominal operating condition of OPR1000, i.e., Re=4x10<SUP>5</SUP>.

Tsp66E, the Drosophila KAI1 homologue, and Tsp74F function to regulate ovarian follicle cell and wing development by stabilizing integrin localization

Han, S.Y.,Lee, M.,Hong, Y.K.,Hwang, S.,Choi, G.,Suh, Y.S.,Park, S.H.,Lee, S.,Lee, S.H.,Chung, J.,Baek, S.H.,Cho, K.S. North-Holland Pub ; Elsevier Science Ltd 2012 FEBS letters Vol.586 No.22

The metastasis suppressor KAI1/CD82 has been implicated in various cellular processes; however, its function in development is not fully understood. Here, we generated and characterized mutants of Tsp66E and Tsp74F, which are Drosophila homologues of KAI1/CD82 and Tspan11, respectively. These mutants exhibited egg elongation defects along with disturbed integrin localization and actin polarity. Moreover, the defects were enhanced by mutation of inflated, an αPS2 integrin gene. Mutant ovaries had elevated αPS2 integrin levels and reduced endocytic trafficking. These results suggest that Drosophila KAI1/CD82 affects the polarized localization and the level of integrin, which may contribute to epithelial cell polarity.

Controllable modification of the conduction properties of carbon nanotube devices through deposition of a metal overlayer onto the sidewalls

Park, N.,Lee, A.R.,Kim, H.S.,Kim, J.J.,Lee, J.O. North-Holland 2012 Physica E, Low-dimensional systems & nanostructure Vol.44 No.7

The effects of metal contacts and metal overlayers on the electrical properties of carbon nanotubes (CNTs) were studied. We show that the conduction properties of a CNT device can be controllably designed through metal depositions on the sidewall even though the conduction type is not clearly defined by the work function of the contact metal. The conversion from an n-type to a p-type conductor was observed with deposition of an overlayer using a large work function metal (Pd), whereas a p-type to n-type conversion was observed with deposition of an overlayer using a low work function metal (Ti). This behavior was attributed to charge transfer doping or the local bending of nanotube bands beneath the metal overlayer. First-principle calculations revealed that charge transfer doping may be uniquely defined by the work function difference if a metal layer forms a weak contact with the sidewall of a CNT.

Systematic treatment of circular logics in a fault tree analysis

Lim, H.G.,Han, S.H. North-Holland Pub. Co 2012 Nuclear engineering and design Vol.245 No.-

An occurrence of a circular logic (CL) has been a problematic issue in a fault tree analysis (FTA). A variety of methods have been developed to solve and/or to treat the CL in a fault tree (FT). The CL may be generated if a system is finally supported by itself in a FT structure. The circulation of supporting relations among several systems can result in such a self-supporting relation of a system. The present article suggests a treatment method of the CL. The main idea to treat a CL is to use the initial condition of a system before its failure. A decision rule for two types of CLs is introduced to remove or break CLs depending on the initial conditions of a system. It has been shown that a CL can be properly handled through real examples of CL from a Probabilistic Safety Analysis (PSA). In addition, an algorithm is proposed to automatically treat the CLs for complex FT containing numerous CLs.

The crystal structure of arginyl-tRNA synthetase from Homo sapiens

Kim, H.S.,Cha, S.Y.,Jo, C.H.,Han, A.,Hwang, K.Y. North-Holland Pub ; Elsevier Science Ltd 2014 FEBS letters Vol.588 No.14

Arginyl-tRNA synthetase (ArgRS) is a tRNA-binding protein that catalyzes the esterification of l-arginine to its cognate tRNA. l-Canavanine, a structural analog of l-arginine, has recently been studied as an anticancer agent. Here, we determined the crystal structures of the apo, l-arginine-complexed, and l-canavanine-complexed forms of the cytoplasmic free isoform of human ArgRS (hArgRS). Similar interactions were formed upon binding to l-canavanine or l-arginine, but the interaction between Tyr312 and the oxygen of the oxyguanidino group was a little bit different. Detailed conformational changes that occur upon substrate binding were explained. The hArgRS structure was also compared with previously reported homologue structures. The results presented here may provide a basis for the design of new anticancer drugs, such as l-canavanine analogs.