Regulation of transferrin recycling kinetics by PtdIns[4,5]P ₂ availability

Kim, Sunyun,Kim, Hyunmyung,Chang, Belle,Ahn, Namhui,Hwang, Suha,Di Paolo, Gilbert,Chang, Sunghoe,Kim, Sunyun,Kim, Hyunmyung,Chang, Belle,Ahn, Namhui,Hwang, Suha,Di Paolo, Gilbert,Chang, Sunghoe Federation of American Society for Experimental Bi 2006 The FASEB Journal Vol.20 No.13

<P>Phosphatidylinositol 4,5-bisphosphate (PtdIns[4,5]P2) is a phosphoinositide involved in a variety of cellular functions, including signal transduction, organelle trafficking, and actin dynamics. Although the role of PtdIns[4,5]P2 in endocytosis is well established, the precise trafficking steps relying on normal PtdIns[4,5]P2 balance in the endosomal pathway have not yet been elucidated. Here we show that decrease in intracellular PtdIns[4,5]P2 levels achieved by the overexpression of the 5-phosphatase domain of synaptojanin 1 or by siRNA knock-down of PIP5Ks expression lead to severe defects in the internalization of transferrin as well as in the recycling of internalized transferrin back to the cell surface in COS-7 cells. These defects suggest that PtdIns[4,5]P2 participates in multiple trafficking and/or sorting events during endocytosis. Coexpression of the PtdIns[4,5]P2 synthesizing enzyme, PIP5KI gamma, was able to rescue these endocytic defects. Furthermore, decreased levels of PtdIns[4,5]P2 caused delays in rapid and slow membrane recycling pathways as well as a severe backup of endocytosed membrane. Taken together, our results demonstrate that PtdIns[4,5]P2 availability regulates multiple steps in the endocytic cycle in non-neuronal cells.</P>

Challenges to Next Generation Services in IP Multimedia Subsystem

Chang, Kai-Di,Chen, Chi-Yuan,Chen, Jiann-Liang,Chao, Han-Chieh Korea Information Processing Society 2010 Journal of information processing systems Vol.6 No.2

The trend of Next Generation Networks' (NGN) evolution is towards providing multiple and multimedia services to users through ubiquitous networks. The aim of IP Multimedia Subsystem (IMS) is to integrate mobile communication networks and computer networks. The IMS plays an important role in NGN services, which can be achieved by heterogeneous networks and different access technologies. IMS can be used to manage all service related issues such as Quality of Service (QoS), Charging, Access Control, User and Services Management. Nowadays, internet technology is changing with each passing day. New technologies yield new impact to IMS. In this paper, we perform a survey of IMS and discuss the different impacts of new technologies on IMS such as P2P, SCIM, Web Service and its security issues.

A survey of Trust Management in WSNs, Internet of Things and Future Internet

( Kai-di Chang ),( Jiann-liang Chen ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

Nowadays, most researchers and manufacturers always pay attention on wireless sensor networks (WSNs) due to its potential applications in many regions such as military, industrial and civilian areas. WSNs are the basic components of Internet of Things (IoT) and the key to machine-to-machine communications and the future Internet. Also, the security is an essential element for deploying WSNs. Recently the concept of trust-based mechanism was proposed in WSNs such as traditional cryptographic and authentication mechanisms. However, there is lack a survey on trust management for WSNs, IoT even future Internet. In this paper, we discuss the concept and potential application areas of trust management for WSNs and IoT worlds. Furthermore, we survey different trust management issues (i.e., cluster, aggregation, reputation). Finally, future research directions with respect to trust management in WSNs and future IoT world are provided. We give not only simple WSNs for IoT environments but also a simulated bootstrap platform to provide the discussion of open challenges and solutions for deploying IoT in Future Internet.

Apoptosis of Human Burkitt’s Lymphoma Cells Induced by 2-N,NDiethylaminocarbonyloxymethyl-1-diphenylmethyl-4-(3,4,5-trimethoxybenzoyl) piperazine Hydrochloride (PMS-1077)

Wen-di Wang,Xi-ming Xu,Ying Chen,Peng Jiang,Chang-zhi Dong,Qin Wang 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12

Piperazine is one of the heterocycles which are associated with diverse pharmacological activities. 2-N,N-Diethylaminocarbonyloxymethyl-1-diphenylmethyl-4-(3,4,5-trimethoxybenzoyl) piperazine hydrochloride (PMS-1077) is a trisubstituted piperazine which contains a trimethoxybenzene ring and a benzhydrylpiperazine fragment, both of which can induce cell proliferation regression by different mechanisms. We have therefore examined the effects of PMS-1077 on Human Burkitt’s lymphoma cells (Raji). The viability of Raji cells was determined by MTT assay and also assessed by trypan blue dye exclusion method. The results demonstrate that PMS-1077 can suppress the proliferation of Raji cells in a dose- and timedependent manner, while inhibit colony formation ability of Raji cells merely in a dose-dependent manner in vitro. Meanwhile, morphological changes were observed using fluorescence microscope. Flow cytometric analysis through PI stains showed that PMS-1077 blocked the growth of Raji cells in the G0/G1 period, and induced apoptosis of Raji cells after 48 h of incubation. Cell apoptosis induced by PMS-1077 was further confirmed by staining with Annexin-V FITC and PI. Preliminary study by molecular docking suggests that PMS-1077 may inhibit tubulin polymerization. More experiments are in progress in our laboratory to reveal the mode of action of PMS-1077 in the induction of apoptosis of Raji cells.

Advanced Path-Migration Mechanism for Enhancing Signaling Efficiency in IP Multimedia Subsystem

( Kai-di Chang ),( Chi-yuan Chen ),( Shih-wen Hsu ),( Han-chieh Chao ),( Jiann-liang Chen ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

Since Internet Protocol (IP) is the most important protocol in Next Generation Networks (NGNs), 3rd Generation Partnership Project (3GPP) utilizes Session Initial Protocol (SIP) based on IP as the base protocol for negotiating sessions in IP Multimedia Subsystem (IMS). Different from traditional circuit-switched network, in IMS, the media traffic and signaling are delivered through IP transport. The media traffic may affect the signaling efficiency in core network, due to traffic collisions and best effort packets delivery. This paper proposes a novel path-migration mechanism for enhancing the traffic efficiency in integrated NGN-IMS. The simulation results show that the interference and traffic collision can be reduce by applying proposed path-migration mechanism and the signaling efficiency in core network can be improved with higher system capability and voice quality.

Challenges to Next Generation Services in IP Multimedia Subsystem

Kai Di Chang,Chi Yuan Chen,Jiann Liang Chen,Han Chieh Chao 한국정보처리학회 2010 Journal of information processing systems Vol.6 No.2

Key competencies and characteristics for innovative teaching among secondary school teachers: a mixed-methods research

Chang ZhuAffiliated,Di Wang 서울대학교 교육연구소 2014 Asia Pacific Education Review Vol.15 No.2

This research aims to understand the key competencies and characteristics for innovative teaching as perceived by Chinese secondary teachers. A mixed-methods research was used to investigate secondary teachers’ views. First, a qualitative study was conducted with interviews of teachers to understand the perceived key competencies and characteristics for innovative teaching among Chinese secondary teachers. Seventeen characteristics were identified underlying four key competencies that were perceived critical for innovative teaching. Secondly, an instrument was developed in order to validate the identified key competencies and characteristics and to measure teachers’ perceived importance of the key competencies and characteristics for innovative teaching. A total of 325 secondary teachers participated in the survey. The results show that the four-factor model of key competencies for innovative teaching was validated and the importance level of the perceived characteristics was also identified. This research has theoretical and practical significance with regard to the development of competence-based teacher education programs.

Modeling volatile organic compounds sorption on dry building materials using double-exponential model

Chang Nyung Kim,Baoqing Deng,Di Ge,Jiajia Li,Yuan Guo 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.7

A double-exponential surface sink model for VOCs sorption on building materials is presented. Here, the diffusion of VOCs in the material is neglected and the material is viewed as a surface sink. The VOCs concentration in the air adjacent to the material surface is introduced and assumed to always maintain equilibrium with the materialphase concentration. It is assumed that the sorption can be described by mass transfer between the room air and the air adjacent to the material surface. The mass transfer coefficient is evaluated from the empirical correlation, and the equilibrium constant can be obtained by linear fitting to the experimental data. The present model is validated through experiments in small and large test chambers. The predicted results accord well with the experimental data in both the adsorption stage and desorption stage. The model avoids the ambiguity of model constants found in other surface sink models and is easy to scale up.

A Robust and Removable Watermarking Scheme Using Singular Value Decomposition

Di, Ya-Feng,Lee, Chin-Feng,Wang, Zhi-Hui,Chang, Chin-Chen,Li, Jianjun Korean Society for Internet Information 2016 KSII Transactions on Internet and Information Syst Vol.10 No.12

Digital watermarking techniques are widely applied to protect the integrity and copyright of digital content. In a majority of the literature for watermarking techniques, the watermarked image often causes some distortions after embedding a watermark. For image-quality-concerned users, the distortions from a watermarked image are unacceptable. In this article, we propose a removable watermarking scheme that can restore an original-like image and resist signal-processing attacks to protect the ownership of an image by utilizing the property of singular value decomposition (SVD). The experimental results reveal that the proposed scheme meets the requirements of watermarking robustness, and also reestablishes an image like the original with average PSNR values of 59.07 dB for reconstructed images.

Alcoholic and Nonalcoholic Fatty Liver Disease and Incident Hospitalization for Liver and Cardiovascular Diseases

Chang, Yoosoo,Cho, Juhee,Cho, Yong Kyun,Cho, Ara,Hong, Yun Soo,Zhao, Di,Ahn, Jiin,Sohn, Chong Il,Shin, Hocheol,Guallar, Eliseo,Ryu, Seungho Elsevier 2020 Clinical gastroenterology and hepatology Vol.18 No.1

<P><B>Background & Aims</B></P> <P>We compared the associations of nonalcoholic fatty liver disease (NAFLD) and alcohol-associated fatty liver disease (AFLD) with risk of incident hospitalization for liver and cardiovascular diseases.</P> <P><B>Methods</B></P> <P>We collected data from the Kangbuk Samsung Health Study on 218,030 men and women in Korea who underwent a health examination from 2011 through 2016. Fatty liver disease (FLD) was detected by ultrasound during the initial examination. The Fibrosis-4 index was used to identify individuals with liver fibrosis. Participants were followed up for as long as 5.9 years and data on hospitalizations for liver and cardiovascular diseases were collected.</P> <P><B>Results</B></P> <P>The prevalence of NAFLD was 22.0% and the prevalence of AFLD was 6.4%. Over a median follow-up period of 4.2 years, we observed 51 and 1097 incident cases of liver disease– or cardiovascular disease–related hospitalizations, respectively. After adjustment for potential confounders, the multivariable-adjusted hazard ratios for liver disease–related hospitalization, comparing NAFLD and AFLD with the reference category (no excessive alcohol intake and no FLD), were 1.73 (95% CI, 0.76–3.96) and 5.00 (95% CI, 2.12–11.83), respectively. The corresponding hazard ratios for cardiovascular disease hospitalization were 1.20 (95% CI, 1.02–1.40) and 1.08 (95% CI, 0.86–1.34), respectively. Among participants with FLD, the risk of liver disease–related hospitalization increased with high Fibrosis-4 index scores, whereas the risk of incident cardiovascular disease did not.</P> <P><B>Conclusions</B></P> <P>In a large cohort study, we found an increased risk of liver disease–related hospitalizations for patients with NAFLD or AFLD, especially among those with Fibrosis-4 index scores. An increased risk of cardiovascular disease–associated hospitalization was observed in patients with NAFLD but not AFLD.</P>