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Nanowire crystal transformation method was newly developed by a KAIST research team.
Figure 1
Schematic illustration of NW crystal transformation process. FeSi is converted to Fe3Si by high-temperature thermal annealing in diluted O2 condition and subsequent wet etching by 5% HF.
Figure 2
Low-resolution TEM images of FeSi; Fe3Si@SiO2 core—shell; Fe3Si NW after shell-etching; and Scale bars are 20 nm
Professor Bongsoo Kim of the Department of Chemistry, KAIST, and his research team succeeded to fabricate Heusler alloy Fe3Si nanowires by a diffusion-driven crystal structure transformation method from paramagnetic FeSi nanowires. This methodology is also applied to Co2Si nanowires in order to obtain metal-rich nanowires (Co) as another evidence of the structural transformation process. The newly developed nanowire crystal transformation method, Professor Kim said, would be valuable as a general method to fabricate metal-rich silicide nanowires that are otherwise difficult to synthesize.
Metal silicide nanowires are potentially useful in a wide array of fields including nao-optics, information technology, biosensors, and medicine. Chemical synthesis of these nanowires, however, is challenging due to the complex phase behavior of silicides.
The metal silicide nanowires are grown on a silicon substrate covered with a thin layer of silicon oxide via a simple chemical vapor deposition (CVD) process using single or multiple source precursors. Alternatively, the nanowires can be grown on the thin silicon oxide film via a chemical vapor transport (CVT) process using solid metal silicide precursors.
The CVT-based method has been highly effective for the syntheses of metal silicide NWs, but changing the composition of metal silicide NWs in a wider range, especially achieving a composition of a metal to silicon, has been quite difficult.
Thus, developing efficient and reliable synthetic methods to adjust flexibly the elemental compositions in metal silicide NWs can be valuable for the fabrication of practical spintronic and neonelectronic devices.
Professor Kim expliained, “The key concept underlying this work is metal-enrichment of metal silicide NWs by thermal diffusion. This conversion method could prove highly valuable, since novel metal-rich silicide NWs that are difficult to synthesize but possess interesting physical properties can be fabricated from other metal silicide NWs.”
The research result was published in Nanao Letters, a leading peer-reviewed journal, and posted online in early August 2010.
2010.08.25 View 11896 -
An internationally renowned academic journal published the research result produced by a KAST research team on its cover.
Fc DAAP VEGF-Trap
Photograph showing the gross features of tumor growth along the mesentery-intestinal border. T: tumor. Scale bars represent 5 mm.
Professor Gou-Young Koh of the Biological Sciences Department, KAIST, and his research team published their research result in Cancer Cell, a peer-review scientific journal, as a cover article dated August 17, 2010. It is the first time for the journal to pick up a paper written by a Korean research team and publish it as the cover.
It has been known that a vascular growth factor (VEGF) is closely related to the growth of a tumor. The research team recently discovered that in addition to VEGF, another growth factor, angiopoietin-2 (Ang2), is also engaged with the increase of tumors.
Professor Koh said, “VEGF and the angiopoietins play critical roles in tumor progression and metastasis, and a single inhibitor targeting both factors have not been available.”
The team led by Professor Koh has developed a double anti-angiogenic protein (DAAP) that can simultaneously bind VEGF-A and the angiopoietins and block their actions.
Professor Koh said in his paper, “DAAP is a highly effective molecule for regressing tumor angiogenesis and metastasis in implanted and spontaneous solid tumor; it can also effectively reduce ascites formation and vascular leakage in an ovarian carcinoma model. Thus, simultaneous blockade of VEGF-A and angiopoietins with DAAP is an effective therapeutic strategy for blocking tumor angiogenesis, metastasis, and vascular leakage.”
So far, cancer patients have received Avastin, anticancer drug, to inhibit VEGF, but the drug has not successfully restrained the growth of cancer tumors and brought to some of the patients with serious side effects instead.
Professor Koh said, “DAAP will be very effective to control the expansion of tumor growth factors, which will open up a new possibility for the development of more helpful cancer medicine with low side effects.”
2010.08.20 View 12876 -
Bioengineers develop a new strategy for accurate prediction of cellular metabolic fluxes
A team of pioneering South Korean scientists has developed a new strategy for accurately predicting cellular metabolic fluxes under various genotypic and environmental conditions. This groundbreaking research is published in the journal Proceedings of the National Academy of Sciences of the USA (PNAS) on August 2, 2010.
To understand cellular metabolism and predict its metabolic capability at systems-level, systems biological analysis by modeling and simulation of metabolic network plays an important role. The team from the Korea Advanced Institute of Science and Technology (KAIST), led by Distinguished Professor Sang Yup Lee, focused their research on the development of a new strategy for more accurate prediction of cellular metabolism.
“For strain improvement, biologists have made every effort to understand the global picture of biological systems and investigate the changes of all metabolic fluxes of the system under changing genotypic and environmental conditions,” said Lee. The accumulation of omics data, including genome, transcriptome, proteome, metabolome, and fluxome, provides an opportunity to understand the cellular physiology and metabolic characteristics at systems-level. With the availability of the fully annotated genome sequence, the genome-scale in silico (means “performed on computer or via computer simulation.”) metabolic models for a number of organisms have been successfully developed to improve our understanding on these biological systems. With these advances, the development of new simulation methods to analyze and integrate systematically large amounts of biological data and predict cellular metabolic capability for systems biological analysis is important.
Information used to reconstruct the genome-scale in silico cell is not yet complete, which can make the simulation results different from the physiological performances of the real cell. Thus, additional information and procedures, such as providing additional constraints (constraint: a term to exclude incorrect metabolic fluxes by restricting the solution space of in silico cell) to the model, are often incorporated to improve the accuracy of the in silico cell.
By employing information generated from the genome sequence and annotation, the KAIST team developed a new set of constraints, called Grouping Reaction (GR) constraints, to accurately predict metabolic fluxes. Based on the genomic information, functionally related reactions were organized into different groups. These groups were considered for the generation of GR constraints, as condition- and objective function- independent constraints. Since the method developed in this study does not require complex information but only the genome sequence and annotation, this strategy can be applied to any organism with a completely annotated genome sequence.
“As we become increasingly concerned with environmental problems and the limits of fossil resources, bio-based production of chemicals from renewable biomass has been receiving great attention. Systems biological analysis by modeling and simulation of biological systems, to understand cellular metabolism and identify the targets for the strain improvement, has provided a new paradigm for developing successful bioprocesses,” concluded Lee. This new strategy for predicting cellular metabolism is expected to contribute to more accurate determination of cellular metabolic characteristics, and consequently to the development of metabolic engineering strategies for the efficient production of important industrial products and identification of new drug targets in pathogens.”
2010.08.05 View 14591 -
Native-like Spider Silk Produced in Metabolically Engineered Bacterium
Microscopic picture of 285 kilodalton recombinant spider silk fiber
Researchers have long envied spiders’ ability to manufacture silk that is light-weighted while as strong and tough as steel or Kevlar. Indeed, finer than human hair, five times stronger by weight than steel, and three times tougher than the top quality man-made fiber Kevlar, spider dragline silk is an ideal material for numerous applications. Suggested industrial applications have ranged from parachute cords and protective clothing to composite materials in aircrafts. Also, many biomedical applications are envisioned due to its biocompatibility and biodegradability.
Unfortunately, natural dragline silk cannot be conveniently obtained by farming spiders because they are highly territorial and aggressive. To develop a more sustainable process, can scientists mass-produce artificial silk while maintaining the amazing properties of native silk? That is something Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, the Republic of Korea, and his collaborators, Professor Young Hwan Park at Seoul National University and Professor David Kaplan at Tufts University, wanted to figure out. Their method is very similar to what spiders essentially do: first, expression of recombinant silk proteins; second, making the soluble silk proteins into water-insoluble fibers through spinning.
For the successful expression of high molecular weight spider silk protein, Professor Lee and his colleagues pieced together the silk gene from chemically synthesized oligonucleotides, and then inserted it into the expression host (in this case, an industrially safe bacterium Escherichia coli which is normally found in our gut). Initially, the bacterium refused to the challenging task of producing high molecular weight spider silk protein due to the unique characteristics of the protein, such as extremely large size, repetitive nature of the protein structure, and biased abundance of a particular amino acid glycine. “To make E. coli synthesize this ultra high molecular weight (as big as 285 kilodalton) spider silk protein having highly repetitive amino acid sequence, we helped E. coli overcome the difficulties by systems metabolic engineering,” says Sang Yup Lee, Distinguished Professor of KAIST, who led this project. His team boosted the pool of glycyl-tRNA, the major building block of spider silk protein synthesis. “We could obtain appreciable expression of the 285 kilodalton spider silk protein, which is the largest recombinant silk protein ever produced in E. coli. That was really incredible.” says Dr. Xia.
But this was only step one. The KAIST team performed high-cell-density cultures for mass production of the recombinant spider silk protein. Then, the team developed a simple, easy to scale-up purification process for the recombinant spider silk protein. The purified spider silk protein could be spun into beautiful silk fiber. To study the mechanical properties of the artificial spider silk, the researchers determined tenacity, elongation, and Young’s modulus, the three critical mechanical parameters that represent a fiber’s strength, extensibility, and stiffness. Importantly, the artificial fiber displayed the tenacity, elongation, and Young’s modulus of 508 MPa, 15%, and 21 GPa, respectively, which are comparable to those of the native spider silk.
“We have offered an overall platform for mass production of native-like spider dragline silk. This platform would enable us to have broader industrial and biomedical applications for spider silk. Moreover, many other silk-like biomaterials such as elastin, collagen, byssus, resilin, and other repetitive proteins have similar features to spider silk protein. Thus, our platform should also be useful for their efficient bio-based production and applications,” concludes Professor Lee.
This work is published on July 26 in the Proceedings of the National Academy of Sciences (PNAS) online.
2010.07.28 View 18940 -
The 8th International Conference on Metabolic Engineering was held on June 13-18, 2010 in Jeju Island, South Korea.
From left to right, top row: Distinguished Professor and the conference chair Sang Yup Lee, Sang-Hyup Kim - Secretary to the President of Korea, Dr. Jay Keasling, Dr. Greg Stephanopoulos. Left to right, bottom row: Dr. William Provine, Dr. Terry Papoutsakis, Dr, Jens Nielsen, Dr. Lars Nielsen.
The importance of industrial biotechnology that produces chemicals and materials from renewable biomass is increasing due to climate change and the dearth of natural resources. Industrial biotechnology refers to a technology that allows sustainable bio-based production of chemicals and materials that could enrich human"s lives using microorganisms. This is where metabolic engineering comes into play for successful application of microorganisms, in which they are engineered in our intended way for improved production capability.
The 8th International Conference on Metabolic Engineering, the longest running conference of its kind, was held on June 13-18, 2010 at the International Convention Center in Jeju Island, South Korea. Distinguished Professor Sang Yup Lee of KAIST, Dean of College of Life Science and Bioengineering and Co-Director of Institute for the BioCentury, chaired the conference with the main theme of "metabolic engineering for green growth."
With 300 delegates selected by the committee, papers on production of biofuels, chemicals, biopolymers, and pharmaceutics and the development of fundamental metabolic engineering techniques were presented at the conference along with examples of successful commercialization of products developed by several global companies.
Sang Hyup Kim, Secretary to the President of Korea, gave an opening plenary lecture entitled "Korean green growth initiative," to inform experts from around the globe of the leadership on green growth in Korea. Young Hoon Park, President of Korea Research Institute of Bioscience and Biotechnology (KRIBB, Korea) delivered his congratulatory address.
Sang Hyup Kim said, "Hosting an international conference in Korea on metabolic engineering, which forms a core technology necessary for the development of environmentally friendly processes for producing chemicals and biofuels from renewable biomass, is very meaningful as green growth is a big issue around the globe. This is a great chance to show the excellence of Korea"s green growth associated technology to experts in metabolic engineering and industrial biotechnology."
A total of 47 invited lectures in this conference included recent and important topics, for instance, "Synthetic biology for synthetic fuels" by Dr. Jay Keasling from the Joint BioEnergy Institute (USA), "Microbial oil production from renewable feedstocks" by Dr. Greg Stephanopoulos from MIT (USA), "Yeast as a platform cell factory for production of fuels and chemicals" by Dr. Jens Nielsen from Chalmers University (Sweden), "Mammalian synthetic biology - from tools to therapies" by Dr. Martin Fussengger from ETH (Switzerland), "Building, modeling, and applications of metabolic and transcriptional regulatory networks at a genome-scale" by Dr. Bernhard Palsson from the University of California - San Diego (USA), "Genome analysis and engineering Eschericha coli for sucrose utilization" by Dr. Lars Nielsen from the University of Queensland (Australia), "Artificial microorganisms by synthetic biology" by Dr. Daniel Gibson from JCVI (USA), and "Metabolomics and its applications" by Dr. Masaru Tomita from Keio University (Japan). From Korea, Dr. Jin Hwan Park from the research group of Dr. Sang Yup Lee at KAIST presented "Systems metabolic engineering of Escherichia coli for amino acid production," and Dr. Ji Hyun Kim from KRIBB presented "Genome sequencing and omics systems analysis of the protein cell factory of Escherichia coli".
Global companies involved in biorefinery presented their recent research outcomes with emphasis on commercialized technologies. They included "Metabolic and process engineering for commercial outcomes" by Dr. William Provine from DuPont (USA), "Direct production of 1,4-butanediol from renewable feedstocks" by Dr. Mark Burk from Genomatica (USA), "Development of an economically sustainable bioprocess for the production of bio 1,2-propanediol" by Dr. Francis Voelker from Metabolic Explorer (France), "Biotechnology to the bottom-line: low pH lactic acid production at industrial scale" by Dr. Pirkko Suominen from Cargill (USA), "Bioisoprene™: traditional monomer, traditional chemistry, sustainable source" by Dr. Gregg Whited from Danisco (USA) and "Efficient production of pharmaceuticals by engineered fungi" by Dr. Roel Bovenberg from DSM (Netherlands).
This biennial conference also presented the International Metabolic Engineering Award (expanded version of the previous Merck Metabolic Engineering Award) to the best metabolic engineer in the world. The 2010 International Metabolic Engineering Award went to Dr. E. Terry Papoutsakis from the University of Delaware (USA) who has contributed to the production of biobutanol through the metabolic engineering of Clostridia in the last three decades, and he gave an award lecture. Dr. Sang Yup Lee, the current chair of the upcoming conference, was the previous recipient of this award at the last metabolic engineering conference in 2008.
In addition to the invited lectures, a total of 156 carefully selected poster papers were chosen for presentation, and awards were presented to the best posters after rigorous review by the committee members. Such awards included "The 2010 Metabolic Engineering Best Poster Award" and the "2010 Young Metabolic Engineer Award" from the Metabolic Engineering conference, and prestigious international journal awards, including "Wiley Biotechnology Journal Best Poster Award", "Wiley Biotechnology and Bioengineering Best Poster Award" and "Elsevier Metabolic Engineering Best Paper Award." Dr. Catherine Goodman, a senior editor of Nature Chemical Biology, also presented the "Nature Chemical Biology Best Poster Award on Metabolic Engineering."
Regarding this conference, Dr. Sang Yup Lee, the conference chair, said, "This conference is the best international conference in the field of metabolic engineering, which is held every two years, and Korea is the first Asian country to host it. All the experts and students spend time together from early breakfast to late poster sessions, which is a distinct feature of this conference. Although the number of delegates had typically been limited to 200, around 300 delegates were selected this year to accept more attendees from many people who have been interested in metabolic engineering. Also, it is very fitting that "green growth" is the main topic of this conference because Korea is playing a key role in this field. I"m grateful to the Lotte Scholarship Foundation, COFCO, GS Caltex, Bioneer, US DOE, US NSF, Daesang, CJ Cheiljedang, Genomatica and DuPont who provided us with generous financial support that allowed the successful organization of this conference."
The conference was organized by the Systems Biology Research Project Team supported by the Ministry of Eduction, Science and Technology (MEST), Microbial Frontier Research Project Group, World Class University Project Group at KAIST, Institute for the BioCentury at KAIST, Korean Society for Biotechnology and Bioengineering, and the Engineering Conference International (ECI) of the United States.
Inquiries: Professor Sang Yup Lee (+82-42-350-3930), industrialbio@gmail.com
2010.06.25 View 20134 -
President of Israel visited KAIST on June 9, 2010.
President of Israel, Shimon Peres, visited KAIST today on June 9, 2010 to witness the development of science and technology in Korea and explore ways of establishing collaboration and cooperation with industries and universities between Korea and Israel. President Peres led a delegation consisted of the Israeli Mister of Industry, Trade, and Labor, the Minister of Communication, and 60 business leaders from the top companies in the security, infrastructure, communication, high-tech, and water industries.
Upon their arrival to the campus, the Israeli delegation was greeted by KAIST’s humanoid robot, “HUBO,” and then moved to its branch campus, IT Convergence Campus, for a ride of Online Electric Vehicle (OLEV) that has been developed by KAIST. The OLEV receives the necessary power through the cable lines buried underground, so it can be provided with a constant and continuous supply of electricity while running or stopping.
Between roads and OLEVs is nothing but space. There is no electrical wires intricately crossed underbody of the electric car or above the road. The pick-up equipment installed beneath the body of the electric car collects magnetic fields created around the underground cables, which then converts the filed into electricity. The OLEV’s wireless, non-contact charging system made it possible for a battery currently used for hybrid or pure electric cars on the market to be smaller and cheaper.
President Peres expressed a great interest in the technology applied to the OLVE, quoting, “the OLEV system is indeed very impressive.” He talked about efforts being made in Israel with respect to the development of electric cars. The country plans to replace the conventional transportation system with electric cars by constructing a network of battery exchange stations and roadside charge points which allow the cars to be charged whenever they are parked.
“Despite the different approach taken by the two nations for the development of electric cars, I believe that transforming the automobile industry from combustion engine to electric system is the right direction we should all follow. Without addressing the current transportation system that heavily dependent on natural resources, we will not be able to promote “green growth on a global scale,” added President Peres.
In addition to electric cars, President Peres took up a considerable portion of his time to exchange ideas on how to expand cooperative relations between universities in Korea and Israel, specifically in the area of space, biotechnology, nanotechnology, high-tech, renewable and alternative energy, and the EEWS initiatives that have been implemented by KAIST to find answers to global issues such as climate change and depletion of natural resources. The EEWS stands for energy, environment, water, and sustainability.
In response, the president of KAIST pledged to set up a stronger and greater tie with research universities in Israel, particularly called for more collaboration between KAIST and Technion-Israel Institute of Technology.
Also, the Israeli delegation had a tour for several Korean research and development centers in Daedeok Innopolis, located in the City of Daejeon, which is the 2nd largest science and research complex in Korea.
Shimon Peres, the 9th president of Israel, held many of important government positions in Israel, among other things, Prime Minster and Minister of Defense. He won Nobel Peace Prize in 1994, together with Yitzhak Rabin and Yasser Arafat for the conclusion of a peace agreement, Oslo Accords, between Israel and Palestine Liberation Organization.
2010.06.09 View 17479 -
KAIST held an opening ceremony for the completion of KAIST Institute Building.
A Korean American businessman and his wife, Byiung Jun Park and Chunghi Hong, donated 10 million USD for the construction of the building.
KAIST hosted an opening ceremony on May 11, 2010 for the new addition to its campus, called the Chunghi & Byiung Jun (BJ) Park KAIST Institute Building. The KI Building will serve as a hub for creative multidisciplinary researches.
A Korean American businessman and his wife made a considerable contribution for the construction of the building, worth 10 million USD. KAIST called the building Byiung Jun (BJ) Park and Chunghi Hong in recognition of their contribution. Chairman Park was the founder of the Merchandise Testing Laboratory, a leading textile quality control multinational.
It took 19 months to finish the construction of the KI Building with a total cost of 36 billion Korean won. The building consists of one basement and five ground floors. At the basement, there are clean room and equipment storage room; on the 2nd and 3rd floors, conference and exhibition halls; and on the rest of the floors, research labs and administration offices are to be located.
KAIST’s eight integral research institutes will be placed inside the building: the BioCentury; Information Technology Convergence; Design of Complex Systems; Entertainment Engineering; the NanoCentury; Eco-Energy; Urban Space and Systems; and Optical Science and Technology. Approximately 230 professors from 25 departments of various academic fields will make the KI Building home for study and research. The KI Building will play a great role in producing world-class convergence research works by KAIST researchers and professors, thereby making a contribution to the improvement of national competitiveness.
Vice President of KI Building, Sang-Soo Kim, said, “There has been no such place for us to concentrate research manpower and equipment scattered around the campus. By having all the necessary resources at one place will allow us to conduct convergence researches more efficiently and effectively. I’d like to express my appreciation for the Ministry of Education and Science and Technology as well as Chairman Byiung Jun (BJ) Park, who gave us tremendous supports in the process of constructing the KI Building.”
“The building’s inside has a unique office structure, getting rid of walls or partitions between institutes or departments, to stimulate an environment conducive to convergence researches. We hope to present a new model for creative multidisciplinary researches through a selective and focused approach to be facilitated by institutes at the KI Building,” added by the vice president.
2010.05.20 View 13024 -
KAIST listed 27 research subjects for EEWS.
The Office of EEWS Initiative at KAIST announced 27 research projects to be implemented in 2010. The EEWS stands for energy, environment, water, and suitability.
KAIST established the EEWS Office in 2008 in efforts to solve problems facing mankind today such as depletion of natural resources, environment pollution, climate changes, water shortages, and sustainable growth. On the nationwide, the Korean government has taken initiatives to support “green growth” and “green technology” projects.
In 2009, the EEWS Office supported 24 research projects and received 28 patent rights, 6 patent registrations, and 57 Science Citation Index (SCI) papers. This year, the office chose 27 research subjects including 7 flagship projects: flexible lithium polymer batteries, spent nuclear fuel recycling, highly efficient bio-butanol, liquid electrolyte battery solid oxide fuel cell, LED lighting, artificial photosynthesis, and nano organic solar cells. New research topics begun this year include energy-saving desalination system and ultra-thin film of silicon solar cells.
Jae-Kyu Lee, Dean of EEWS Initiative Office said, “Having multiple volume of small-scaled, topic-focused research projects will encourage us to come up with large-scale convergence research projects. In so doing, we can explore new frontiers of science and technology and serve as the new growth engine for the development of green technology and industry in Korea.”
All the research projects selected will be subject to evaluations. For example, the EEWS Initiative Office will host an international workshop in September 2010 where it plans to introduce and evaluate the ongoing research projects.
2010.05.19 View 10571 -
A KAIST graduate to become a professor at a prestigious university in UAE
A KAIST graduate to become a professor at a prestigious university in UAE
Dr. Jerald Yoo, a KAIST graduate, has been appointed as an assistant professor at the Masdar Institute of Science and Technology (MIST) in Abu Dhabi, United Arab Emirates (UAE), by the recommendation of the Massachusetts Institute of Technology (MIT) since April 1, 2010.
The MIST is a private, not-for-profit, independent, research-driven institute developed with the support and cooperation of MIT and the Abu Dhabi government, which was opened in September 2009. Currently, at the school, there are 25 professors and 100 students from 22 countries around the world. The institute has a campus in Masdar City where the Abu Dhabi government plans to nurture it as a “place for zero carbon emissions.”
According to an agreement between the MIST and MIT, Professor Yoo will teach and work on co-research projects at MIT for one year beginning in May 2010 and then working at the MIST thereafter.
Professor Yoo received all of his degrees (BS, MS, and Ph.D.) from KAIST majoring in electrical engineering and earned his doctoral degree in January 2010. His research works included developing a wearable patch to monitor bio signals with an application of wearable sensor networks and low energy electronic circuit technologies. During his doctoral study, Professor Yoo published papers at the IEEE International Solid-State Circuits Conference (ISSCC) and in journals of IEEE Solid-State Circuits Society (SSCS).
Professor Yoo said, "The wearable health care system is certainly necessary to improve the quality of our lives, and the field should receive a sustaining support for further research. I will do my best to continuously produce valuable research results and hope that my research works will be helpful for an academic exchange between South Korea and Abu Dhabi.”
About the Masdar Institute of Science and Technology (MIST) in Abu Dhabi:
http://www.masdar.ac.ae/
The Masdar Institute is the centerpiece of the Masdar Initiative, a landmark program announced in April 2006 by the government of Abu Dhabi to establish an entirely new economic sector dedicated to alternative and sustainable energy. Masdar is a highly-strategic initiative with primary objectives of: helping drive the economic diversification of Abu Dhabi; maintaining and expanding Abu Dhabi"s position in evolving global energy markets; positioning Abu Dhabi as a developer of technology; and making a meaningful contribution towards sustainable human development.
The Masdar Institute is a private, not-for-profit, independent, research-driven institute developed with the support and cooperation of the Massachusetts Institute of Technology (MIT). The Institute offers Masters and (eventually) PhD programs in science and engineering disciplines, with a focus on advanced energy and sustainable technologies. It welcomes and encourages applications from qualified local and international students and provides fellowships to talented students who meet its high admission standards. Its faculty is of the highest quality and the intent is to have the structure of its top administration similar to MIT"s.
2010.04.13 View 13612 -
New drug targeting method for microbial pathogens developed using in silico cell
A ripple effect is expected on the new antibacterial discovery using “in silico” cells
Featured as a journal cover paper of Molecular BioSystems
A research team of Distinguished Professor Sang Yup Lee at KAIST recently constructed an in silico cell of a microbial pathogen that is resistant to antibiotics and developed a new drug targeting method that could effectively disrupt the pathogen"s growth using the in silico cell.
Hyun Uk Kim, a graduate research assistant at the Department of Chemical and Biomolecular Engineering, KAIST, conducted this study as a part of his thesis research, and the study was featured as a journal cover paper in the February issue of Molecular BioSystems this year, published by The Royal Society of Chemistry based in Europe.
It was relatively easy to treat infectious microbes using antibiotics in the past. However, the overdose of antibiotics has caused pathogens to increase their resistance to various antibiotics, and it has become more difficult to cure infectious diseases these days.
A representative microbial pathogen is Acinetobacter baumannaii. Originally isolated from soils and water, this microorganism did not have resistance to antibiotics, and hence it was easy to eradicate them if infected. However, within a decade, this miroorganism has transformed into a dreadful super-bacterium resistant to antibiotics and caused many casualties among the U.S. and French soldiers who were injured from the recent Iraqi war and infected with Acinetobacter baumannaii.
Professor Lee’s group constructed an in silico cell of this A. baumannii by computationally collecting, integrating, and analyzing the biological information of the bacterium, scattered over various databases and literatures, in order to study this organism"s genomic features and system-wide metabolic characteristics. Furthermore, they employed this in silico cell for integrative approaches, including several network analysis and analysis of essential reactions and metabolites, to predict drug targets that effectively disrupt the pathogen"s growth. Final drug targets are the ones that selectively kill pathogens without harming human body.
Here, essential reactions refer to enzymatic reactions required for normal metabolic functioning in organisms, while essential metabolites indicate chemical compounds required in the metabolism for proper functioning, and their removal brings about the effect of simultaneously disrupting their associated enzymes that interact with them.
This study attempted to predict highly reliable drug targets by systematically scanning biological components, including metabolic genes, enzymatic reactions, that constitute an in silico cell in a short period of time.
This research achievement is highly regarded as it, for the first time, systematically scanned essential metabolites for the effective drug targets using the concept of systems biology, and paved the way for a new antibacterial discovery. This study is also expected to contribute to elucidating the infectious mechanism caused by pathogens.
"Although tons of genomic information is poured in at this moment, application research that efficiently converts this preliminary information into actually useful information is still lagged behind. In this regard, this study is meaningful in that medically useful information is generated from the genomic information of Acinetobacter baumannii," says Professor Lee. "In particular, development of this organism"s in silico cell allows generation of new knowledge regarding essential genes and enzymatic reactions under specific conditions," he added.
This study was supported by the Korean Systems Biology Project of the Ministry of Education, Science and Technology, and the patent for the development of in silico cells of microbial pathogens and drug targeting methods has been filed.
[Picture 1 Cells in silico]
[Picture 2 A process of generating drug targets without harming human body while effectively disrupting the growth of a pathogen, after predicting metabolites from in silico cells]
2010.04.05 View 17346
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Photonic crystals allow the fabrication of miniaturized spectrometers
By Courtesy of Nanowerk
Photonic crystals allow the fabrication of miniaturized spectrometers
(Nanowerk Spotlight) Spectrometers are used in materials analysis by measuring the absorption of light by a surface or chemical substance. These instruments measure properties of light over a specific portion of the electromagnetic spectrum. In conventional spectrometers, a diffraction grating splits the light source into several beams with different propagation directions according to the wavelength of the light. Thus, to achieve sufficient spatial separation for intensity measurements at a small slit, a long light path – i.e., a large instrument – is required.
However, for lab-on-a-chip or microTAS (total analysis system) applications, the spectrometer must be integrated into a sub-centimeter scale device to produce a stand-alone platform. To achieve this, researchers at the Korea Advanced Institute of Science and Technology (KAIST) propose a new paradigm in which the spectrometer is based on an array of photonic crystals with different bandgaps.
"Because photonic crystals refelct light of different wavelengths selectively depending on their bandgaps, we can generate reflected light spanning the entire wavelength range for analysis at different spatial positions using patterned photonic crystals," Seung-Man Yang, Director of the National Creative Research Initiative Center for Intergrated Optofluidic Systems and Professor of the Department of Chemical & Biomolecular Engineering at KAIST, tells Nanowerk. "Therefore, when the light source impinges on the patterned photonic crytals, we can construct the spectrum using the reflection intensity profile from the constituent photonic crystals."
Photonic crystals – also known as photonic band gap material – are similar to semiconductors, only that the electrons are replaced by photons (i.e. light). By creating periodic structures out of materials with contrast in their dielectric constants, it becomes possible to guide the flow of light through the photonic crystals in a way similar to how electrons are directed through doped regions of semiconductors. The photonic band gap (that forbids propagation of a certain frequency range of light) gives rise to distinct optical phenomena and enables one to control light with amazing facility and produce effects that are impossible with conventional optics.
To demonstrate this new concept based on patterned photonic crystals, Yang and his group used non-close-packed colloidal crystals of silica particles dispersed in photocurable resin. Due to the repulsive interparticle potential, monodisperse silica particles spontaneously crystallize into non-close-packed face-centered cubic (fcc) structures at volume fractions above 0.1. Therefore, the particle volume fraction determines both the lattice constant and the bandgap position.
a) Optical image of an ETPTA film containing porous photonic crystal stripe patterns with 20 different bandgaps. b) Reflectance spectra from the 20 strips. c) Optical microscope image of the middle region with the parallel stripe pattern (denoted as white-dotted box in a). d) Cross-sectional SEM images of first, sixth, eleventh and seventeenth strips. The scale bars in a, c and d are 1 cm, 2mm and 2 µm, respectively. (reprinted with permission from Wiley-VCH Verlag)
Reporting their findings in a recent issue of Advanced Materials ("Integration of Colloidal Photonic Crystals toward Miniaturized Spectrometers"), the KAIST team has demonstrated the integration of colloidal photonic crystals with 20 different bandgaps into freestanding films (prepared by soft lithography), and their application as a spectrometer.
Yang explains that the team was able to precisely control the photonic bandgap by varying the particle size and volume fration.
"The prepared colloidal composite structures showed high physical rigidity and chemical resistivity" he says. "The composite structure is suitable for spectroscopic use due to the small full widths at half maximum (FWHMs) of the reflectance spectra, which mean that there is little overlap of the reflectance spectra of neighboring photonic crystal strips."
"On the other hand" says Yang, "porous photonic crystals showed large FWHMs and high reflectivities, which should prove useful in many practical photonic applications that require high optical performance and physical rigidity as well as simple and inexpensive preparation."
In addition to fabricating miniaturized spectrometers, which can for instance be integrated into small lab-on-a-chip devices, these integrated photonic crystals can be potentially used for tunable band reflection mirrors, optical switches, and tunable lasing cavities. Moreover, patterned photonic crystals with RGB colors are well-suited for use in reflection-mode microdisplay devices.
Yang points out that, although the spectrometric resolution can be reduced by employing the smaller bandgap interval and photonic bandwidth, there is a limitation. "Now, we are studying photonic crystals with continuous modulation of bandgap position. We expect that the photonic crystals can reduce the resolution to 0.01 nm."
By Michael Berger. Copyright 2010 Nanowerk
2010.03.17 View 14745
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KAIST Commencement 2010 was held on February 26, 2010.
A total of 2,205 are the newly conferred degree holders: 479 for Ph.D., 988 for Master’s, and 738 for B.S. degrees. Since its foundation in 1971, KAIST has so far produced 38,882 graduates.
KAIST held the 2010 graduation ceremony on February 26, 2010 at its newly built place, called “Sports Complex Building.” Approximately 2,500 guests including Minister Byung-Man Ahn, Education, Science and Technology Ministry; Chairman Mun-Sul Jeong, KAIST Board of Trustees; representatives from the KAIST alumni; graduating students; and faculty joined the ceremony to celebrate the commencement.
Honorary Doctorates
At the ceremony, KAIST has conferred four honorary doctorate degrees in recognition of recipients’ contribution to the advancement of science and technology and development of science and engineering education in Korea and the world. The recipients were Arden L. Bement Jr., Director of US National Science Foundation; Lars Pallesen, President of Technical University of Denmark; Donald C.W. Kim, Chairman of AMKOR A&E, Inc.; and Beang-Ho Kim, Chairman of Seojeon Farm.
Graduation Honors: President’s List
Dong-Han Kim, majoring in Mathematical Sciences, College of Natural Science, was nominated as President’s List. He received an award for an outstanding academic achievement from the Minister of Education, Science and Technology and gave a gradation speech on behalf of the graduating class.
Birthplace of Promising Young Scientists in Korea
KAIST has earned a reputation for training the next generation of young scientists in Korea, and its 2010 Commencement has confirmed such fame. Among 479 Ph.D. degree holders, 151 (31%) students are in their 20s. The youngest who has received a doctoral degree is Jin-Ah Lee, graduating from College of Life Science and Bioengineering.
Commencing International Students
Among international students graduating this year, two students from India received their doctoral degrees in Biological Sciences: Kataru Raghu Prasad and Chaya Mohan. They are a married couple and now both postdoctoral researchers, working at KAIST labs. Wearing academic regalia and standing together to take a picture, the couple said, “We would definitely recommend KAIST to prospective international students because it offers the best education and research facilities comparable to those of any leading universities in the world. With the knowledge and experience acquired from studying at KAIST, we hope to contribute to the development of our country in the future.”
2010.03.04 View 15425