SUNGKYUNKWAN UNIVERSITY (SKKU), SEOUL, KOREA


January-February, 2018 Vol. 1
Worldwide
  • "SKKU, A University Always Ahead of Its Time" by Nature
  • Rector of RWTH Aachen University Visits SKKU
  • SKKU Holds Southeast Asia Sungkyun Writing Contest
Discovery
  • SKKU Ranks No.2 in Korean University Rankings by JoongAng Daily
  • SKKU Ranks 200th in U.S. News & World Report's 2018 Global University Rankings
  • SKKU Ranks 1st Korean Private Comprehensive University in the 2018 Asia University Rankings
  • SKK GSB Ranked as No. 1 MBA Program in Korea and No. 54 in the World by FT
Top Schools
  • H.E. Ernesto Cordero Arroyo, Speaker of the Mexican Senate, Gives Special Lecture at SKKU
  • The 5th Korea-Russia Rector's Forum
  • SKKU-Leiden Joint Forum Successfully Held on Jan 31st
  • AORC Signs MOU with the Center for Combinatorics at Nankai University and the Center for Applied Mathematics
Leading Alumni in a Global Society
  • New Year's Message from SKKU President CHUNG Kyu-sang
Leading Alumni in a Global Society
  • Noticeable Articles Recently Published in Journals
Leading Alumni in a Global Society
  • 2017 Graduate School of China ìéÓáìéÒÊ Long March
  • SKKU Receives Best Students Project Award at IETF Hackathon 2017
  • Capstone Design Team Wins Gold Medal at 2017 iENA
Leading Alumni in a Global Society
  • 647 International Students Newly Entered SKKU in Fall 2017
Lithium-ion Battery with 5x Capacity Developed

Through a collaborative research project of Prof. PARK Nam-gyu together with Samsung Electronics a semiconductor material that can reduce the amount of radiation exposure while taking medical X-ray images to less than 1/10 has been developed. The "X-ray detector" can increase sensitivity over 20 times more than conventional flat X-rays by using the perovskite semiconductor material.

An X-ray detector is a kind of image sensor that absorbs X-rays. The new material developed by the research team has high sensitivity, so it is possible to obtain a clear medical image while reducing the radiation dose. The cost of production is also low. Unlike conventional detectors, which are made by vacuum processing used in semiconductor manufacturing, the new detector can be made through a liquid process, so a large screen can be made. If this technology is commercialized, it will be possible to make X-ray devices that can take an image of the whole body at once. Perovskite has the excellent characteristic of converting light into an electric current, so it is a material that is very popular in the fields of solar cells and X-rays.

X-ray devices are widely used for medical purposes because they can convert X-rays transmitted through the human body into pictures and images, but they are expensive and result in large doses of radiation. For this reason, research and development projects to reduce X-ray exposure are being widely carried out in the United States, European Union, etc.

The research team expects that X-ray devices that can dramatically reduce X-ray exposure will be developed in a few years. If the remaining technical problems are improved, X-ray medical imaging technology that reduces the radiation dose to less than 1/10 is expected to be available in the practical field of medicine.

The results of this research have been published in the online edition of the worldwide scientific journal "Nature" with the title "Printable Organometallic Perovskite Enables Large-Area, Low-Dose X-Ray Imaging".

Find more information at:
http://www.nature.com/articles/nature24032

The Instant a Water Drop Evaporates Has Been Captured

By imitating the antennae of insects, ultrafast H2 sensors that require no additional electrical apparatus were developed. The new sensors that realize high hydrogen detection performance and safety simultaneously can be widely applied from precise measuring equipment to simple leak alarms, so it is expected to have a great ripple effect across the industry and households in the future.

Hydrogen is used as an essential material in many industries such as petroleum, chemicals, and steel, and its usage is increasing every year in everyday life. However, the use of a hydrogen leak detection system is essential because it can explode easily, even when the concentration exceeds only 4% in the air. Existing commercialized hydrogen sensors such as electrochemical sensors, catalytic sensors, acoustic sensors, ceramic sensors, and semiconductor sensors require additional apparatuses such as displays and speakers. These also requires a power supply for hydrogen detection, which increases the risk of explosion when hydrogen is leaked.

In order to overcome these limitations, sensors that use optical signals instead of electrical signals and make it possible to detect the leakage of hydrogen visually have been developed. However, because these are usually based on chemical reactions between hydrogen and reactive materials, the response time is slow. In addition, since these have irreversible characteristics at room temperature, the possibility of actual commercialization is very low.

In order to develop a hydrogen sensor with high sensitivity and a high response rate without the need for power, the researchers developed nano-microactuators that change their shape in response to hydrogen by imitating the antenna structures of insects. These nano-microactuators are made by coating palladium on the flexible polymer asymmetrically. Hydrogen gas stimulation can be detected visually without an additional display and power supply by maximizing the changes in the optical characteristics of the dev ice due to changes in the shape of the nano-microactuators by hydrogen. Furthermore, the researchers developed a new hydrogen sensitive locking device capable of controlling adhesion by hydrogen by wetting-controllable H2-selective smart surfaces.

The results of this research can be applied not only to existing industries such as petroleum, chemicals, and steel, but also to everyday life such as hydrogen stations, hydrogen vehicles, and fuel cell distributed generation systems. Especially, because of its distinguishable advantages including being a non-power source, non-explosive, and ultrasensitive, it is expected to be in high demand with the explosive growth of the hydrogen fuel cell market. Also, the fact that it is produced at low cost compared with existing hydrogen sensors although it requires no additional electrical apparatus and makes it possible to detect hydrogen with the naked eye is makes it competitive both at home and abroad.

This study was supported by a middle-grade researcher leap business and leading research center of the Ministry of Science and ICT, and it was selected as an online edition cover paper of "Advanced Functional Materials (Impact Factor = 12.124)".

Find more information at:
http://onlinelibrary.wiley.com/doi/10.1002/adfm.201770170/full

Restraining Fat Stem Cell Differentiation to Avoid Child Obesity

A tumor is a devastating disease, and it is important to apply appropriate therapeutic and diagnostic tools to accurately detect the cancer stage and type. Early detection of cancer is associated with a higher percentage of recovery after treatment, and it is more important to identify the molecular signature of cancer as early as possible. Micro-RNA, which is abbreviated miR or miRNA, has recently been shown to be a potential tumor-associated signature that can indicate early cancer development. In addition, because miRNAs regulate transcription of mRNA in the upper level of the cascade, a miRNA network significantly influences cellular metabolism, development, differentiation, establishment, and even stress response. miRNA profiles provide essential clues about metabolic heterology in tumorigenesis. Types and mechanisms of cancer-specific miRNAs can be identified for clinical index. Quantification of multiple miRNAs in a living cell leads to better understanding of cancer. Significant correlation of specific miRNA variances that exist during progression from primary tumor to metastasis can be used to predict the effective diagnosis of whole-stage cancer. Moreover, in addition to a change of tumor concept, in which there is a successive process of clonal evolution at the tumor site, cell-to-cell variation and interfacial communication should be detected for personalized medicine.

Several nanotechnology-based systems were developed for miRNA detection at the cellular level. However, quantitative analysis of multiplex miRNAs in a living cell is difficult due to the cellular transport kinetics of each cell type To date, Prof. UM Soong-ho and Dr. SHIN Seung-won present a novel miRNA detection platform using fluorescence-encoded nanostructured DNA probing for quantitative analysis of multiplexed miRNAs in living cells. His research group has been working for over a decade to design novel molecular diagnostic tool kits based on DNA nanotechnology for biomedical purposes. Nanotechnology-engineered platforms as synthesized can provide highly programmable and predictable labeling of various miRNAs specific to the type of cancer in a technically simple manner at the molecular scale. In this study, Prof. UM and his colleagues demonstrate that it is eventually possible to encode fluorescence colors of cancer-specific miRNA signatures in cells using new DNA nanotechnology and to track the presence of fluorescent cells in situ.

Prof. Um speculates that this novel nanostructured DNA-based diagnosis can provide not only important information for tumorigenesis, but can also be applied in personalized medicine as an easy-to-use toolkit. This demonstration of efficient cancer cell labeling and its in situ cancer-staged tracking and tumor heterogeneity, which may be not easy to be realized without this new scientific toolkit, will be of great interest to anyone who is seeking a new scientific report for progressive technology developments in cutting-edge cancer diagnosis methods.

This work was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare as well as the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning, Republic of Korea.

Find more information at:
http://www.nature.com/articles/s41598-017-13456-3

Finding New Protein to Cure Obesity and Metabolic Diseases

The research group of Professor KIM In-su at SKKU's School of Pharmacy has published its outstanding work in the October issue of "Advanced Synthesis & Catalysis (IF 6.453, JCR ranking 1.4%, in applied chemistry)" and was highlighted as the cover picture.

Prof. Kim's group has developed a Rh(III)-catalyzed novel synthetic method for 7-azaindole compounds, which is known as a key unit structure of drug molecules. In particular, by introducing a selective and efficient amination reaction of the carbon-hydrogen bond, they have developed a new effective substance which shows stronger anticancer effects than existing anticancer drugs.

Prof. Kim is pursuing research to maximize the efficiency of new drug development under the theme "Late-Stage Drug Optimization laboratory". In particular, he has been studying to produce new drug candidates that have anti-cancer, anti-diabetic, and antimicrobial effects. The results of the study showed that the unit structure containing an amine group was introduced into azaindole compounds found in a variety of pharmaceutical molecules. Synthetic compounds have been shown to have superior anticancer properties than doxorubicin, a well-known anticancer drug.

Prof. Kim said, "As a new technology that is different from conventional methods, it is a new way to drastically improve the synthesis process of pharmaceuticals, especially anticancer drugs," and "As part of the development of new anticancer drugs, we plan to develop new anticancer drug molecules through our synthetic methodology."

This research was carried out with the support of the Basic Research Support Program (BRL) initiated by the Ministry of Science, ICT and Future Planning (Minister, Young Min YOU) and the National Research Foundation of Korea.

Find more information at:
http://onlinelibrary.wiley.com/doi/10.1002/adsc.201701100/full

‘The World Class High-Performance Photodetector’ Has Finally Been Created

A research collaboration team led by Prof. LEE Jin-yong (Dept. of Chemistry) and Prof. Francesc Illas (University of Barcelona, Spain) theoretically investigated the changes of band alignment according to the size of titanium dioxide nanoparticles using quantum calculations. This research was published in the "Journal of the Physical Chemistry Letters (IF: 9.353, JCR top 1.4 %)" as November 16, 2017, with the title "Size-Dependent Level Alignment between Rutile and Anatase TiO2 Nanoparticles: Implications for Photocatalysis".

Titanium dioxide is definitely the most popular resource for photocatalytic materials in the fields of academia and industry. They have commonly used a mixture of nanoparticles of anatase and rutile polymorphs to increase photocatalytic activity. Up until now, various experiments have been conducted to demonstrate the type of band alignment between two polymorphs. However, there are many difficulties to guarantee the same experimental condition and uniformity of titanium dioxide samples in each experiment. For this reason, several different types of band alignment have been reported from many experiments. Still many arguments about the type of band alignment have not been agreed upon yet. Prof. Lee's group theoretically investigated the changes of band alignment according to the size of titanium dioxide nanoparticles based on quantum calculations for the first time. This work will be very useful to make researchers comprehensively understand the photocatalytic activities of various experiments handling titanium dioxide nanoparticles.

Prof. Lee said, "Our theoretical prediction properly explains the type of band alignment for Degussa P25, which is composed of anatase and rutile titanium dioxide nanoparticles and has been the most widely used commercially. Our results on the nanoparticle size effect could provide invaluable information to explain the photocatalytic activity changes between different titanium dioxide samples in real experiments."

This research was supported by the National Research Foundation of Korea (NFR) and Korea Institute of Science and Technology Information (KISTI) supercomputing center.

Find more information at:
https://pubs.acs.org/doi/abs/10.1021/acs.jpclett.7b02474

A Conductive Nano-Bio Composite 'Fullerene-Protein' Structure in a Regular Arrangement

Dr. JANG Am, a Professor from the College of Construction and Environmental System Engineering and Graduate School of Water Resources, and his research team have developed a volume retarded osmosis (VRO) - low pressure membrane (LPM) hybrid system. The discovery has led to the publication of a paper in "Scientific Report (Impact factor=4.259, upper 16% of JCR journal in multidisciplinary sciences field)", a journal from the publishers of Nature, on November 6, 2017. Additionally, they have identified the initial organic fouling phenomenon that could occur in the spiral-wound forward osmosis process at semi-pilot scale, with the use of real wastewater and the membrane surface analysis method. This lead to a publication in "Chemical Engineering Journal (primary author: Im Sung-ju, phD student) (Impact factor = 6.216, upper 4.5% of JCR journals in chemical engineering field)", one of the most influential journals around the world, on November 2, 2017.

Forward Osmosis (FO) technology is a water treatment technology based on the osmotic pressure gradient of both solutions (feed and draw). It has been actively studied in academia and industry, and is considered as a substitute for reverse osmosis-based seawater desalination technology and a next-generation desalination technology. In general, since the forward osmosis technology requires a post-treatment technique for separating the draw solute from a high concentration of the draw solution, many researches and attempts have been made to develop an appropriate post-treatment technique. However, the high operating pressure (energy) of the post-treatment technology is pointed out as a limitation of the forward osmosis technology, and the development of a forward osmosis process that does not require post treatment, or post treatment with low or no energy requirement is urgently needed.

Through this research, Prof. Jang and his research team, was the first to devise and develop a water treatment system design that can utilize the pressure to be used as the driving force for the low pressure membrane by increasing the solution volume of a closed tank. The value of this study is immeasurably high. Due to the fact that the limitation of the existing osmosis process was improved upon and the possibility of the practical use of the osmosis process was increased, the direction of new osmosis technology was suggested through the study. In addition, the spiral wound forward osmosis element is the most common form of conventional element types, and it is similar to the reverse osmosis module that is used for seawater desalination. To date, the identification of the fouling phenomena of forward osmosis membranes has been limited to laboratory scale (Lab-scale) or to identifying them using model foulants. However, there are limitations in terms of operating conditions and structural characteristics of elements in order to apply the results to the actual process (element scale or pilot scale). Professor Jang's research team determined the initial fouling mechanism, when the spiral wound forward osmosis element was used with wastewater as feed solution. The results of this study are very valuable, since they can help comprehensively understand the fouling mechanism of forward osmosis, allow prediction of overall fouling phenomena in the actual process, and help understand the overall development of the forward osmosis process.

Prof. Jang said, "The results of this study are of great significance in regard to overcoming the limitations of the forward osmosis process, a next generation water treatment technology. Not only is it significant, but the results from this study are also valuable, since understanding of the fouling phenomena is the key factor in the development of forward osmosis technology."

Based on the results of this study, IM Sung-ju, a PhD student and the first author of the published paper, presented at the International Desalination Workshop 2017, and was given an award by the Ministery of Land, Transport and Tourism.

This study was carried out through research on the forward osmosis-reverse osmosis hybrid system, which is supported by the Korea Agency for Infrastructure Technology Advancement, and through monitoring of irreversible foulants in the osmosis-based membrane process, supported by a research project of the Korea Research Foundation.

Find more information at:
http://www.nature.com/articles/s41598-017-15274-z
https://www.sciencedirect.com/science/article/pii/S1385894717319289

‘The World Class High-Performance Photodetector’ Has Finally Been Created

A team comprised of Prof. RHEE Dongk-won (SKKU School of Pharmacy) and Dr. SONG Man-ki (International Vaccine Institute (IVI)) developed a novel vaccine that can prevent the influenza (flu) virus and pneumococcal infections. The vaccine they developed is highly feasible as a novel vaccine for preventing or mitigating the influenza virus as well as pneumococcal infections.

To prevent flu infection, it is highly recommended to get vaccinated every year. Also, for pneumococcal disease prevention, the 23 valent polysaccharide vaccine or 13 valent conjugate vaccine is recommended. However, the live attenuated vaccine the team developed can prevent these irrelevant two infections at the same time.

In the future, a new variety of flu virus infection could lead to significant mortality, due to secondary bacterial infections such as pneumococci and staphylococcus aureus after flu virus infection. Thus, it is essential to develop a vaccine that can prevent secondary bacterial infections after a flu pandemic. However, the current 13 valent conjugate vaccine cannot prevent the pneumococcus infection effectively after flu infection (Metzger et al., 2015).

The team developed an attenuated pneumococcus vaccine devoid of the "pep27'" gene and immunized mice intranasally. Subsequently, the immunized mice were challenged with flu virus followed by pneumococcus infections. The immunized group showed a significantly higher survival rate than the non-immunized group. Through this study, they also discovered that mice immunized with the live attenuated pneumococcal vaccine showed no body weight decrease after flu virus infection. Since body weight decrease is a token trait of flu virus infection, this discovery is highly meaningful. Moreover, the flu virus titer in the immunized mice lungs was much lower than the non-immunized control. This finding could be a milestone in vaccine development since the vaccine can prevent a specific pathogen.

They are now studying how this intranasal vaccine can provide protection from the flu virus as well as pneumococcal infections. Also, they are checking whether this vaccine can provide other pathogen infections.

This study is being supported by the Korea Science Foundation and published in advance as a brief report in the "Journal of Infectious Diseases (Impact Factor 6.273: infectious diseases category top 92.26%)" on June 14.

Find more information at:
https://academic.oup.com/jid/article/217/4/637/4627914

‘The World Class High-Performance Photodetector’ Has Finally Been Created

A team comprised of Prof. LEE Chang-gu's group (SKKU School of Mechanical Engineering) and Prof. RYU Sun-min's group (Department of Chemistry, Postech) identified the crystal lattice structure of a new 2-dimensional (2D) magnetic semiconductor using optical characterization methods. 2D materials, such as graphene, have atomic-level thickness and exhibit excellent electrical, mechanical, and chemical properties, thus are expected to find abundant applications in next-generation opto/electronic devices. The recently studied binary metal chalcogenides, such as MoS2, consist of 2 elements and show various electrical characteristics and will be used for flexible electronics and displays. However, these materials lack one important physical property, which is magnetism. Since silicon-based electronic circuits are approaching the physical limit in their performance, scientists are searching for alternative electronic devices and materials. Hence, they are paying attention to spintronic devices, which utilize spinning motion along with the charge of electrons to operate. Now, 2D magnetic semiconductors can be a good candidate material for spintronic devices and circuits due to their low-dimensionality.

The team studied a ternary 2D magnetic semiconductor CrPS4, which consists of chromium, phosphorus, and sulfur, to investigate its lattice structure using an optical microscope and Raman spectroscopy and confirmed it with a tunneling electron microscope. It is an antiferromagnetic material and has an anisotropic in-plane structure. Therefore, its optical and electrical properties can be dependent on its crystalline orientation. When the polarized light was irradiated on the crystal, the light showed different reflection intensity depending on the crystal direction, and the lattice structure could be identified from angle measurement.

This was an important result because the crystal orientation of a material is usually determined by an expensive tool such as tunneling electron microscope. This method can provide a simple but powerful tool for 2D materials researchers to check the crystalline orientation easily and lower the barrier to high-quality experiments. This research will enable many researchers to study these kinds of materials with ease and can contribute to the study of spintronics using 2D magnetic semiconductors.

This work was published in "ACS Nano" on Nov. 25, 2017.

Find more information at:
https://pubs.acs.org/doi/10.1021/acsnano.7b04679

‘The World Class High-Performance Photodetector’ Has Finally Been Created

Solar-to-chemical and solar-to-fuel production from CO2 have been developed using engineered microorganisms that assimilate CO2 and convert target chemicals and fuels using solar energy. In addition to integrated bio-electrochemical systems, photosynthetic cyanobacteria have been metabolically engineered to redirect CO2 to value-added chemicals as bio-solar cell factories. The research team of Profs. Hanmin WOO and Hyunjeong LEE reported the metabolic engineering of unicellular Synechococcus elongatus PCC 7942 to improve the photosynthetic production of ¥á-farnesene from CO2 in the "Journal of Agricultural and Food Chemistry" December 6, 2017.

As a result of the lack of farnesene synthase (FS) activity in the wild-type cyanobacterium, the research team metabolically engineered S. elongatus PCC 7942 to express heterologous FS from apple fruit, resulting in detectable peaks of ¥á-farnesene. To enhance ¥á-farnesene production, an optimized methylerythritol phosphate (MEP) pathway was introduced in the farnesene-producing strain to supply farnesyl diphosphate. Subsequent cyanobacterial culture with a dodecane overlay resulted in photosynthetic production of ¥á-farnesene from CO2. Prof. Woo said that to the best of our knowledge, this is the first report of photosynthetic production of ¥á-farnesene from CO2 in the unicellular cyanobacterium S. elongatus PCC 7942. This engineered strain could be further optimized to accelerate the development of bio-solar cell factories to convert CO2 to ¥á-farnesene as a value-added bioproduct (fragrance, surfactants, etc.) or ¥á-farnesane, a potential bio-jet fuel.

This work was supported by the Korea Carbon Capture & Sequestration R&D Center the Basic Science Research Program, and through the National Research Foundation of Korea funded by the Korean Government's Ministry of Science and Information and Communications Technology.

Find more information at:
http://pubs.acs.org/doi/full/10.1021/acs.jafc.7b03625

A Conductive Nano-Bio Composite 'Fullerene-Protein' Structure in a Regular Arrangement

A team led by Prof. LEE Young-hee of the Center for Integrated Nanostructure Physics at the Institute for Basic Science has successfully developed a new method for converting monolayer molybdenum disulfide (MoS2) into molybdenum ditelluride (MoTe2) via substitution of tellurium to MoS2 by chemical vapor deposition (CVD). In order to trigger such a substitutional reaction, a high reaction temperature is necessary for Te-substitution, but the instability arises because of the lower thermal stability of MoTe2 than that of MoS2. Although the MoTe2, which is product after Te-substitution, is vaporized above 700 ¡ÆC due to the thermal instability, the substitutional reaction below 700¡Æ C is no longer possible. To resolve this issue, the team introduced sodium telluride (Na2Te) as a telluriding catalyst and was able to achieve stable MoTe2 by provoking substitutional reaction at temperature below 700¡Æ C.

The research team confirmed that the Te-substitution reaction occurs preferentially from the edge and grain boundary of the MoS2 flake and further constructed lateral hetero semiconductor junction of MoS2-MoTe2. Furthermore, various phases such as alloy (MoS2-xTex), semiconductor (2H-MoTe2), and metal (1T'-MoTe2) were obtained by adjusting experimental parameters of temperature and sodium concentration. The team also demonstrated that the band gap of MoS2-xTex alloy can be modulated by controlling the tellurium composition.

Dr. YUN Seok-joon, the leading scientist of the research team, predicted that, "It is possible to synthesize compound materials by a substitutional technique even for the unstable compounds."

The conversion method using the telluriding catalyst (Na2Te) can be applied not only to MoS2, but also to tungsten disulfide (WS2), which is another type of transition metal dichalcogenide.

This research, conducted by Prof. LEE Young-hee and Dr. YUN Seok-joon who is the first author of this research, and was published in "Nature Communications (IF 12.124)", a worldwide scientific journal in science and technology, on December 18, 2017.

Find more information at:
http://www.nature.com/articles/s41467-017-02238-0


ADDRESS HUMANITIES AND SOCIAL SCIENCES CAMPUS : 53 MYEONGHYUN-DONG 3-GA, JONGHO-Gu, SEOUL 110-745, KOREA

MATURAL SCIEMCES CAMPUS : 300 CHEONCHEON-DONG, JANGAN-GU, SUWON, GYEONGGI-DO 440-746, KOREA

COPYRIGHT 2018 SUNGKYUNKWAN UNIVERSITY ALL RIGHTS RESERVED.