Multilateral Engagement of North Korea: An Assessment of the Six-Party Talks and the ASEAN Regional Forum

( Ming Hui Tan ) 서울대학교 통일평화연구원 2017 Asian Journal of Peacebuilding Vol.5 No.2

North Korea’s unchecked missile and nuclear program is one of the most pressing global security concerns. This article evaluates the multilateral engagement efforts that have been pursued by regional stakeholders, specifically assessing the Six-Party Talks vis-a-vis the ASEAN Regional Forum (ARF), and explaining why these multilateral efforts have failed to resolve the nuclear crisis. Given the poor performances of these two multilateral platforms, this article seeks to assess the feasibility and policy implications of defusing the longstanding nuclear crisis through multilateral engagement. Despite stalling and a myriad of obstacles, the Six-Party Talks has a better chance than the ARF at curbing the nuclear crisis. At best, the ARF can contribute by playing a complementary role by helping deescalate tensions or cultivating better diplomatic ties.

Global prevalence of depression and anxiety in patients with hepatocellular carcinoma: Systematic review and meta-analysis

Darren Jun Hao Tan,Sabrina Xin Zi Quek,Jie Ning Yong,Adithya Suresh,Kaiser Xuan Ming Koh,Wen Hui Lim,Jingxuan Quek,Ansel Tang,Caitlyn Tan,Benjamin Nah,Eunice Tan,Taisei Keitoku,Mark D. Muthiah,Nichola 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.4

Background/Aims: Depression and anxiety are associated with poorer outcomes in patients with hepatocellular carcinoma (HCC). However, the prevalence of depression and anxiety in HCC are unclear. We aimed to establish the prevalence of depression and anxiety in patients with HCC. Methods: MEDLINE and Embase were searched and original articles reporting prevalence of anxiety or depression in patients with HCC were included. A generalized linear mixed model with Clopper-Pearson intervals was used to obtain the pooled prevalence of depression and anxiety in patients with HCC. Risk factors were analyzed via a fractional-logistic regression model. Results: Seventeen articles involving 64,247 patients with HCC were included. The pooled prevalence of depression and anxiety in patients with HCC was 24.04% (95% confidence interval [CI], 13.99–38.11%) and 22.20% (95% CI, 10.07–42.09%) respectively. Subgroup analysis determined that the prevalence of depression was lowest in studies where depression was diagnosed via clinician-administered scales (16.07%;95% CI, 4.42–44.20%) and highest in self-reported scales (30.03%; 95% CI, 17.19–47.01%). Depression in patients with HCC was lowest in the Americas (16.44%; 95% CI, 6.37–36.27%) and highest in South-East Asia (66.67%; 95% CI, 56.68–75.35%). Alcohol consumption, cirrhosis, and college education significantly increased risk of depression in patients with HCC. Conclusions: One in four patients with HCC have depression, while one in five have anxiety. Further studies are required to validate these findings, as seen from the wide CIs in certain subgroup analyses. Screening strategies for depression and anxiety should also be developed for patients with HCC.

The role of ginsenoside Rb1, a potential natural glutathione reductase agonist, in preventing oxidative stress-induced apoptosis of H9C2 cells

Hui-Jie Fan,Zhang-Bin Tan,Yu-Ting Wu,Xiao-Reng Feng,Yi-Ming Bi,Ling-Peng Xie,Wen-Tong Zhang,Zhi Ming,Bin Liu,Ying-Chun Zhou 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.2

Background: Oxidative stress-induced cardiomyocytes apoptosis is a key pathological process inischemic heart disease. Glutathione reductase (GR) reduces glutathione disulfide to glutathione (GSH) toalleviate oxidative stress. Ginsenoside Rb1 (GRb1) prevents the apoptosis of cardiomyocytes; however,the role of GR in this process is unclear. Therefore, the effects of GRb1 on GR were investigated in thisstudy. Methods: The antiapoptotic effects of GRb1 were evaluated in H9C2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, annexin V/propidium iodide staining, and Western blotting. Theantioxidative effects were measured by a reactive oxygen species assay, and GSH levels and GR activitywere examined in the presence and absence of the GR inhibitor 1,3-bis-(2-chloroethyl)-1-nitrosourea. Molecular docking and molecular dynamics simulations were used to investigate the binding of GRb1 toGR. The direct influence of GRb1 on GR was confirmed by recombinant human GR protein. Results: GRb1 pretreatment caused dose-dependent inhibition of tert-butyl hydroperoxide-induced cellapoptosis, at a level comparable to that of the positive control N-acetyl-L-cysteine. The binding energybetween GRb1 and GR was positive ( 6.426 kcal/mol), and the binding was stable. GRb1 significantlyreduced reactive oxygen species production and increased GSH level and GR activity without altering GRprotein expression in H9C2 cells. Moreover, GRb1 enhanced the recombinant human GR protein activityin vitro, with a half-maximal effective concentration of z2.317 mM. Conversely, 1,3-bis-(2-chloroethyl)-1-nitrosourea co-treatment significantly abolished the GRb1’s apoptotic and antioxidative effects of GRb1in H9C2 cells. Conclusion: GRb1 is a potential natural GR agonist that protects against oxidative stresseinducedapoptosis of H9C2 cells.

New Non-uniformity Correction Approach for Infrared Focal Plane Arrays Imaging

Qu Hui-Ming,Gong Jing-tan,Huang Yuan,Chen Qian 한국광학회 2013 Current Optics and Photonics Vol.17 No.2

Although infrared focal plane array (IRFPA) detectors have been commonly used, non-uniformity correction (NUC) remains an important problem in the infrared imaging realm. Non-uniformity severely degrades image quality and affects radiometric accuracy in infrared imaging applications. Residual non-uniformity (RNU) significantly affects the detection range of infrared surveillance and reconnaissance systems. More effort should be exerted to improve IRFPA uniformity. A novel NUC method that considers the surrounding temperature variation compensation is proposed based on the binary nonlinear non-uniformity theory model. The implementing procedure is described in detail. This approach simultaneously corrects response nonlinearity and compensates for the influence of surrounding temperature shift. Both qualitative evaluation and quantitative test comparison are performed among several correction technologies. The experimental result shows that the residual non-uniformity, which is corrected by the proposed method,is steady at approximately 0.02 percentage points within the target temperature range of 283 K to 373K. Real-time imaging shows that the proposed method improves image quality better than traditional techniques.

The role of ginsenoside Rb1, a potential natural glutathione reductase agonist, in preventing oxidative stress-induced apoptosis of H9C2 cells

Fan, Hui-Jie,Tan, Zhang-Bin,Wu, Yu-Ting,Feng, Xiao-Reng,Bi, Yi-Ming,Xie, Ling-Peng,Zhang, Wen-Tong,Ming, Zhi,Liu, Bin,Zhou, Ying-Chun The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.2

Background: Oxidative stress-induced cardiomyocytes apoptosis is a key pathological process in ischemic heart disease. Glutathione reductase (GR) reduces glutathione disulfide to glutathione (GSH) to alleviate oxidative stress. Ginsenoside Rb1 (GRb1) prevents the apoptosis of cardiomyocytes; however, the role of GR in this process is unclear. Therefore, the effects of GRb1 on GR were investigated in this study. Methods: The antiapoptotic effects of GRb1 were evaluated in H9C2 cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, annexin V/propidium iodide staining, and Western blotting. The antioxidative effects were measured by a reactive oxygen species assay, and GSH levels and GR activity were examined in the presence and absence of the GR inhibitor 1,3-bis-(2-chloroethyl)-1-nitrosourea. Molecular docking and molecular dynamics simulations were used to investigate the binding of GRb1 to GR. The direct influence of GRb1 on GR was confirmed by recombinant human GR protein. Results: GRb1 pretreatment caused dose-dependent inhibition of tert-butyl hydroperoxide-induced cell apoptosis, at a level comparable to that of the positive control N-acetyl-L-cysteine. The binding energy between GRb1 and GR was positive (-6.426 kcal/mol), and the binding was stable. GRb1 significantl reduced reactive oxygen species production and increased GSH level and GR activity without altering GR protein expression in H9C2 cells. Moreover, GRb1 enhanced the recombinant human GR protein activity in vitro, with a half-maximal effective concentration of ≈2.317 μM. Conversely, 1,3-bis-(2-chloroethyl)-1-nitrosourea co-treatment significantly abolished the GRb1's apoptotic and antioxidative effects of GRb1 in H9C2 cells. Conclusion: GRb1 is a potential natural GR agonist that protects against oxidative stress-induced apoptosis of H9C2 cells.

중국 Changzhou댐의 방수로 운용에 따른 어류밀도와 분포에 관한 음향조사

( Xi Chang Tan ),강명희 ( Myoung Hee Kang ),( Jiang Ping Tao ),( Xin Hui Li ),( Dao Ming Huang ) 한국수산과학회(구 한국수산학회) 2011 한국수산과학회지 Vol.44 No.4

Hydroacoustic surveys were performed to clarify the density and spatial distribution of fish upstream and downstream of Changzhou Dam in the Pearl River, China, with regard to the condition of the spillways. Fish were densely distributed in the forebay of the upstream dam and the average fish density was 0.22 individuals/㎥ under open spillways on 24 June 2010, but when the spillways were closed on 25 June 2010, the fish in the upstream dam dispersed and the average fish density decreased to 0.007 individuals/㎥. Meanwhile, the average fish density in the downstream region was 0.28 individuals/㎥ before the spillway was opened on 24 May 2010, but it decreased to 0.08 individuals/㎥ on 26 June, just after the spillway was closed. The vertical distribution of fish upstream of the dam was not consistent. The target strength (TS) of fish upstream of the dam was larger than that of fish in the downstream region, although the distribution of TS was similar between the upstream and downstream regions. Therefore, we concluded that while numerous fish could swim to the upstream region while the spillways were open, closed spillways obstructed fish migrating upward from the downstream region.

A heat shock protein 70 protects the green peach aphid (Myzus persicae) against high-temperature stress

Chen Nan,Tan Jia-Yu,Wang Ying,Qi Ming-Hui,Peng Jiang-Nan,Chen De-Xin,Liu Su,Li Mao-Ye 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.4

Heat shock proteins (HSPs) are encoded by Hsp genes and are important in insect tolerance to heat stress. The green peach aphid, Myzus persicae, is an important agricultural pest. The functions of Hsp genes in the thermal tolerance of M. persicae are unknown. This study identified an Hsp70 gene (MpHsp70a) and analyzed its role in protection against high-temperature stress. MpHsp70a encoded a protein consisting of 659 amino acid residues. The protein had three signature motifs of the HSP70 family and was predicted to be localized in the cytoplasm. The highest expression level of MpHsp70a was in adults, and differences in the mRNA levels between apterous and alate adults were not significant. Exposure to high temperatures (30, 35 and 40 ◦ C) for one hour and treatment with 40 ◦ C for different times (0.5, 1 and 2 h) all resulted in a greatly elevated expression level of MpHsp70a, suggesting that the gene is heat-inducible. The transcriptional level of MpHsp70a was suppressed by injection with double-stranded RNA (dsRNA), and knockdown of MpHsp70a significantly increased the suscep tibility of apterous adults to 40 ◦ C. These results indicate that MpHsp70a is required for tolerance to hightemperature stress in M. persicae. Our findings highlight the molecular mechanism underlying Hsp70-mediated thermal adaptation in M. persicae.

Investigation on Machining Characteristic of Pneumatic Wheel based on Softness Consolidation Abrasives

Xi Zeng,Shi-ming Ji,Ming-sheng Jin,Da-peng Tan,Jue-hui Li,Wen-tao Zeng 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

In order to improve material removal rate of laser hardening workpiece and also make machining tool suitable for free-form surface,a new method based on the softness consolidation abrasives (SCA) is put forward, which means the abrasives are consolidated onthe outer layer of pneumatic wheel to achieve the softness-machining. Binder selecting test shows that acidic silicone is proved tosuit for consolidating particles in cutting process. Combined with robot, the machining system has been established. The machiningeffects of SCA are investigated when it faces with workpiece of different hardness. According to the Preston predicted model, thesimulation results of stress and velocity are proven by analysis of average roughness in the contact region. The contrastive machiningexperimental results show that SCA can supply high cutting stress for material removal and fit for freeform surface’s machining byself-adjustment of flexible body.

Parecoxib: an Enhancer of Radiation Therapy for Colorectal Cancer

Xiong, Wei,Li, Wen-Hui,Jiang, Yong-Xin,Liu, Shan,Ai, Yi-Qin,Liu, Rong,Chang, Li,Zhang, Ming,Wang, Xiao-Li,Bai, Han,Wang, Hong,Zheng, Rui,Tan, Jing Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Background: To study the effect of parecoxib, a novel cyclooxygenase-2 selective inhibitor, on the radiation response of colorectal cancer (CRC) cells and its underlying mechanisms. Materials and Methods: Both in vitro colony formation and apoptosis assays as well as in vivo mouse xenograft experiments were used to explore the radiosensitizing effects of parecoxib in human HCT116 and HT29 CRC cells. Results: Parecoxib sensitized CRC cells to radiation in vitro with a sensitivity enhancement ratio of 1.32 for HCT116 cells and 1.15 for HT29 cells at a surviving fraction of 0.37. This effect was partially attributable to enhanced apoptosis induction by parecoxib combined with radiation, as illustrated using an in vitro apoptosis assays. Parecoxib augmented the tumor response of HCT116 xenografts to radiation, achieving growth delay more than 20 days and an enhancement factor of 1.53. In accordance with the in vitro results, parecoxib combined with radiation resulted in less proliferation and more apoptosis in tumors than radiation alone. Radiation monotherapy decreased microvessel density (MVD) and microvessel intensity (MVI), but increased the hypoxia level in xenografts. Parecoxib did not affect MVD, but it increased MVI and attenuated hypoxia. Conclusions: Parecoxib can effectively enhance radiation sensitivity in CRC cells through direct effects on tumor cells and indirect effects on tumor vasculature.

Optimization Design of the Electromagnetic Torque for Surface-Mounted PMSM Using GA and Finite Element Analysis for Electric Vehicle

Wong Edric Wee Ming,Mohd-Shafri Syauqina Akmar,Tiang Tow Leong,Tan Choo Jun,Ishak Dahaman,Ahmad Mohd Saufi,Leong Jenn Hwai,Ong Hui Lin 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

This research off ers an optimization design for a three-phase surface-mounted permanent magnet synchronous machine (SMPMSM) by employing the computer framework consists of fi nite element analysis (FEA) and genetic algorithm (GA) utilized in the applications of electric vehicles. This framework aims to evaluate and determine the optimal setting of SMPMSMs, which require maximum average electromagnetic torque ( T em_avg ) and minimum its ripple ( T em_rip ). Several motor performances, such as magnetic fi eld distribution across the motor, magnetic fl ux density distribution in the mid air gap, phase back-EMF, electromagnetic torque, and its ripple, are investigated for the initial and optimal designs of PM machines during open-circuit and on-load conditions by using FEA. The important parameter of PM machines, i.e. the magnet pole-arc and slot opening angle are taken into account. In order to determine the objective function of the GA framework, the T em_avg and the T em_rip are used to formulate the computing equations where the fi tness value provided by the computing framework is further assessed. The GA framework is used to assess the comparison of parameters and motor performance between the initial and optimal designs of 12s/8p PM motors in terms of electromagnetic torque under BLAC operation. Consequently, the framework of FEA and GA has been proven in the design of SMPMSM, which is very viable for electric cars by reducing the magnet materials and electromagnetic torque ripple.