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The Crisis in US-China Bilateral Security Relations
Christopher Yung 경남대학교 극동문제연구소 2021 ASIAN PERSPECTIVE Vol.Special No.-
Although the US and Chinese security relationship has been tense for over three decades, the last three years has seen it slide into acute crisis. The two countries are in a full-blown security dilemma, going after each other’s “core interests,” using their alliances and partnerships to attempt to weaken or restrain the other, and pushing aside confidence-building measures designed to help manage the competitive relationship. Before deriving new policy measures that can foster habits of cooperation between the two countries, the United States and China must create a new strategic consensus around which the bilateral security relationship can be defined.
Hou Angela Yung-Chi,Hill Christopher,Chen Karen Hui Jung,Tsai Sandy 서울대학교 교육연구소 2018 Asia Pacific Education Review Vol.19 No.4
Malaysia, Singapore, China, and South Korea employed branch campuses as a means to develop and promote economic growth and global competitiveness. The aim of this study was to explore national policies and regulatory frameworks for international branch campuses in the four key nations identified above. The development of internal quality assurance mechanisms and external review approaches in international branch campuses were investigated, via in-depth interview and document analysis. The study presented three major findings. First, an inclusive model of internal quality has been developed in international branch campuses found in the four nations. Second, the international branch campuses’ external quality assurance approaches, in the four countries, were diverse and included exemption, reliance on home country accreditation, duplication, and international accreditation. Third, South Korea and Singapore were more closely aligned to liberal regulation with minimal quality assurance, whereas Malaysia and China were in the category of liberal regulation and restrict regulation, respectively, but with comprehensive quality assurance process.
Ee Jean Lim,Khi Yung Fong,Jingqiu Li,Hong Hong Huang,Kenneth Chen,Kae Jack Tay,Christopher Wai Sam Cheng,Henry Sun Sien Ho,Nye Thane Ngo,John Shyi Peng Yuen 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.2
Purpose: To perform a retrospective review of the clinicopathological features of patients with conventional and non-conventional renal cell carcinoma (cRCC and ncRCC). Materials and Methods: A large prospectively maintained uro-oncological registry was accessed to extract clinicopathological data of patients diagnosed with renal tumors who subsequently underwent nephrectomy from 1990–2019. Demographics and operative parameters were extracted. Analyses of overall survival (OS) and cancer-specific survival (CSS) were performed using the Kaplan–Meier method. Cox proportional-hazards analysis was used to identify risk factors which influenced survival. Results: There were a total of 1,686 consecutive nephrectomies which was retrieved, with 1,286 cRCC and 400 ncRCC. The commonest ncRCC subtypes were papillary (n=198, 11.7%), clear cell papillary (n=50, 3.0%) and chromophobe (n=49, 2.9%) RCC. Kaplan–Meier estimates of OS were higher in cRCC (0.74; 95% confidence interval [CI], 0.71–0.78) than ncRCC (hazard ratio, 1.47; 95% CI, 1.16–1.87). Among individual subtypes, chromophobe RCC had the highest 5-year OS (0.90; 95% CI, 0.79–1.0). Among ncRCC subtypes, acquired cystic RCC demonstrated the highest association with end-stage renal failure and hypertension, with the highest CSS. MiT family translocation RCC had the youngest mean age at presentation (45.6±12.8 y) and excellent CSS. Factors associated with increased OS in the entire cohort included shorter operative time, partial nephrectomy and lower tumor stages. Conclusions: This study provides a comprehensive contemporary overview of ncRCCs which are yet poorly characterized, in comparison to cRCCs. Data from this study would contribute towards tailored patient counseling and healthcare resource planning.
Robertson, Alex W.,Lin, Yung-Chang,Wang, Shanshan,Sawada, Hidetaka,Allen, Christopher S.,Chen, Qu,Lee, Sungwoo,Lee, Gun-Do,Lee, Joohee,Han, Seungwu,Yoon, Euijoon,Kirkland, Angus I.,Kim, Heeyeon,Suenag American Chemical Society 2016 ACS NANO Vol.10 No.11
<P>Dopants in two-dimensional dichalcogenides have a significant role in affecting electronic, mechanical, and interfacial properties. Controllable doping is desired for the intentional modification of such properties to enhance performance; however, unwanted defects and impurity dopants also have a detrimental impact, as often found for chemical vapor deposition (CVD) grown films. The reliable identification, and subsequent characterization, of dopants is therefore of significant importance. Here, we show that Cr and V impurity atoms are found in CVD grown MoS2 monolayer 2D crystals as single atom substitutional dopants in place of Mo. We attribute these impurities to trace elements present in the MoO3 CVD precursor. Simultaneous annular dark field scanning transmission electron microscopy (ADF-STEM) and electron energy loss spectroscopy (EELS) is used to map the location of metal atom substitutions of Cr and V in MoS2 monolayers with single atom precision. The Cr and V are stable under electron irradiation at 60 to 80 kV, when incorporated into line defects, and when heated to elevated temperatures. The combined ADF-STEM and EELS differentiates these Cr and V dopants from other similar contrast defect structures, such as 2S self-interstitials at the Mo site, preventing misidentification. Density functional theory calculations reveal that the presence of Cr or V causes changes to the density of states, indicating doping of the MoS2 material. These transferred impurities could help explain the presence of trapped charges in CVD prepared MoS2.</P>
Starch based polyhydroxybutyrate production in engineered Escherichia coli.
Bhatia, Shashi Kant,Shim, Young-Ha,Jeon, Jong-Min,Brigham, Christopher J,Kim, Yong-Hyun,Kim, Hyun-Joong,Seo, Hyung-Min,Lee, Ju-Hee,Kim, Jung-Ho,Yi, Da-Hye,Lee, Yoo Kyung,Yang, Yung-Hun Springer-Verlag 2015 Bioprocess and biosystems engineering Vol.38 No.8
<P>Every year, the amount of chemosynthetic plastic accumulating in the environment is increasing, and significant time is required for decomposition. Bio-based, biodegradable plastic is a promising alternative, but its production is not yet a cost effective process. Decreasing the production cost of polyhydroxyalkanoate by utilizing renewable carbon sources for biosynthesis is an important aspect of commercializing this biodegradable polymer. An Escherichia coli strain that expresses a functional amylase and accumulate polyhydroxybutyrate (PHB), was constructed using different plasmids containing the amylase gene of Panibacillus sp. and PHB synthesis genes from Ralstonia eutropha. This engineered strain can utilize starch as the sole carbon source. The maximum PHB production (1.24?g/L) was obtained with 2?% (w/v) starch in M9 media containing 0.15?% (w/v) yeast extract and 10?mM glycine betaine. The engineered E. coli SKB99 strain can accumulate intracellular PHB up to 57.4?% of cell dry mass.</P>
Polymerization of conducting polymers inside carbon nanotubes
Steinmetz, Johannes,Kwon, Soyoung,Lee, Hyun-Jung,Abou-Hamad, Edy,Almairac, Robert,Goze-Bac, Christophe,Kim, Hwayong,Park, Yung-Woo Elsevier 2006 Chemical physics letters Vol.431 No.1
<P><B>Graphical abstract</B></P><P>Supercritical carbon dioxide impregnation is used to prepare carbon nanotubes filled with pyrrole and <I>N</I>-vinyl carbazole. After the impregnation, the monomers were polymerized inside the nanotubes. The samples are characterized by HRTEM and <SUP>1</SUP>H NMR.</P><ce:figure id='figure.0010'></ce:figure> <P><B>Abstract</B></P><P>Supercritical carbon dioxide is an universal tool to impregnate carbon nanotubes with a wide range of organic molecules. In this Letter, we present our results of carbon nanotubes filled with the photo-conducting polymer poly(<I>N</I>-vinyl carbazole) and the conducting polymer polypyrrole which were prepared by polymerizing the monomers inside the nanotubes. The endohedral nanotubes were characterized by HRTEM and <SUP>1</SUP>H NMR which confirmed that the encapsulated material was indeed the conducting polymer.</P>
Lee, Stanfield Youngwon,Chung, Dong Young,Lee, Myeong Jae,Kang, Yun Sik,Shin, Heejong,Kim, Mi-Ju,Bielawski, Christopher W.,Sung, Yung-Eun American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.43
<P>This study was focused On elucidating the origin of the catalytic activity displayed by non-precious-metal-based, oxygen reduction reaction (ORR) catalysts before and after heat treatment. Electrochemical measurements were recorded using a series of metal phthalocyanines calculated to exhibit varying oxygen adsorption energies before and after heat treatment at a temperature Sufficiently high to facilitate degradation. Collectively, the results indicate that while the oxygen adsorption is germane to the catalytic activity before heat, treatment, the ORR appears to proceed through. a different pathway that is not dependent on adsorption energy after heat treatment. These conclusions help to explain the high catalytic activities exhibited by carbon- or nitrogen-based materials containing metal ions after heat treatment and may lead to the realization of substitutes for ORB. catalysts that utilize precious transition metals.</P>
Correlating Atomic Structure and Transport in Suspended Graphene Nanoribbons
Qi, Zhengqing John,Rodrí,guez-Manzo, Julio A.,Botello-Mé,ndez, André,s R.,Hong, Sung Ju,Stach, Eric A.,Park, Yung Woo,Charlier, Jean-Christophe,Drndić,, Marija,Johnson, A. T. Ch American Chemical Society 2014 NANO LETTERS Vol.14 No.8
<P/><P>Graphene nanoribbons (GNRs) are promising candidates for next generation integrated circuit (IC) components; this fact motivates exploration of the relationship between crystallographic structure and transport of graphene patterned at IC-relevant length scales (<10 nm). We report on the controlled fabrication of pristine, freestanding GNRs with widths as small as 0.7 nm, paired with simultaneous lattice-resolution imaging and electrical transport characterization, all conducted within an aberration-corrected transmission electron microscope. Few-layer GNRs very frequently formed bonded-bilayers and were remarkably robust, sustaining currents in excess of 1.5 μA per carbon bond across a 5 atom-wide ribbon. We found that the intrinsic conductance of a sub-10 nm bonded bilayer GNR scaled with width as <I>G</I><SUB>BL</SUB>(<I>w</I>) ≈ 3/4(<I>e</I><SUP>2</SUP><I>/h</I>)<I>w</I>, where <I>w</I> is the width in nanometers, while a monolayer GNR was roughly five times less conductive. Nanosculpted, crystalline monolayer GNRs exhibited armchair-terminated edges after current annealing, presenting a pathway for the controlled fabrication of semiconducting GNRs with known edge geometry. Finally, we report on simulations of quantum transport in GNRs that are in qualitative agreement with the observations.</P>