Chem
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'Scientist-Engineer of the Month' for December: Professor Choi Joon Ho
Professor Choi Joon Ho (department of Biological Sciences) was made ‘Scientist-Engineer of December’ for his discovery of new gene (twenty-four) that helps biorhythm and proving that this gene helps control biorhythm.
Professor Choi published 100 dissertations over the past 25 years and made significant advancements in the field of molecular virus and neurobiology.
In 1995 Professor Choi uncovered the fact that the NS3 protein in C type hepatitis function as RNA helicase thereby opening the path to developing a cure for C type hepatitis; this is an international patent with Chiron corporation. The result was published in Biochemical and Biophysical Research Communications Journal and was the most domestically referred to dissertation in biological sciences in 1999.
In addition Professor Choi published in Nature magazine in 1999, a dissertation that uncovered the fact that the DNA of papillomar virus has another protein (hSNF5) that direct it apart from ordinary proteins.
In 2000~2005 Professor Choi published many dissertations in journals like Immunity, Cancer Research, Molecular and Cellular Biology, Oncogene, Journal of Virology, and etc.
Professor Choi screened over 10,000 species of pomace fly mutations and discovered the twenty-four gene that affects the biorhythm of pomace flies. He analyzed this gene further and found a new function that was different from known biorhythm mechanisms.
This research allowed a better understanding of biological clock of pomace flies and therefore was another step towards better understanding the control mechanism of human biological clock.
2012.01.31 View 8937 -
Review of organophosphonate nerve agent remediation and sensing chemistry
Professor David Churchill, Dept. of Chemistry, KAIST
Scientists in Daejeon, South Korea and Lexington, Kentucky (USA) have recently published a review on the subject of nerve agent remediation and probing chemistry (Chemical Reviews, DOI:10.1021/cr100193y). This article endeavored to pursue organophosphonate nerve agent chemistry deeply and comprehensively and to reflect that decontamination / sensing and nerve agents / pesticides are quite inextricable: when one tries to degrade nerve agents one also needs to detect what components are still present “downstream,” etc. Nerve agents and many pesticides also share a common generalized organophosphate / -phosphonate structure.
Also, the use of simulant molecules (mimics) and a consideration of the closely related organophosphonate pesticides were also treated comprehensively in the Review. The authors reached back into the literature when developing some sections to make important connections to the contemporary topics of interest. The review also includes industrial insights.
Kibong Kim, Olga G. Tsay and David G. Churchill of the Department of Chemistry at KAIST and David A. Atwood of the Department of Chemistry of the University of Kentucky endeavored to "make a variety of connections in research strategies and (sub-) fields to present what is still possible, fruitful, practical, and necessary and to facilitate a current comprehensive molecular level understanding of organophosphonate degradation and sensing," Churchill says.
The authors feel that for the time being, researchers in varying research areas “can use this manuscript effectively when considering future research directions.”
2011.09.19 View 8502 -
Scientists develop highly efficient industrial catalyst
http://english.yonhapnews.co.kr/business/2011/07/14/48/0501000000AEN20110714009600320F.HTML
SEOUL, July 15 (Yonhap) -- South Korean scientists said Friday that they have developed a highly efficient nanoporous industrial catalyst that can have a considerable impact on chemical and oil-refining sectors.
The team of scientists led by Ryoo Ryong, a chemistry professor at the Korea Advanced Institute of Science and Technology (KAIST), said the solid zeolite compound developed in the laboratory has a reaction speed five to 10 times faster than that of conventional materials.
Zeolite, which is made from silica and aluminium, is frequently used as an absorbent, water purifier and in nuclear reprocessing, although it is mainly employed in the chemical industry.
The annual size of the zeolite market is estimated at US$2.5 billion with output using the material topping $30 billion. At present, 41 percent of all catalysts used in the chemical sector are nano-scale zeolite materials.
The KAIST team said that because the new zeolite is made up of different sized pores, the material can be used as a catalyst when existing materials are unable to act as a changing agent.
"Existing zeolites only have pores under 1 nanometer in diameter, but the new material has holes that range from 1 nanometer to 3.5 nanometers, which are all arranged in a regular honeycomb arrangement," Ryoo said. A nanometer is one-billionth of a meter.
He said the ability to have both micro- and meso-sized pores is key to the faster reaction speed that is an integral part of raising efficiency. The South Korean researchers used a so-called surfactant process to make the different sizes of pores.
The development is a breakthrough because researchers and companies such as Exxon Mobil Corp. have been trying to build zeolite with different sizes of pores for the past two decades without making serious headway. There are more than 200 different types of zeolites in the world.
Ryoo, who received funding from the government, has requested intellectual property rights for the discovery, which has been published in the latest issue of Science magazine. He also developed another zeolite in the past that can transform methanol to gasoline up to 10 times more efficiently than existing catalysts.
Exxon Mobil has expressed interest in the two zeolites made by Ryoo"s team. Undisclosed South Korean petrochemical companies have also made inquiries that may lead to commercial development in the future.
"There are some technical issues to resolve, mainly related with mass production and stability," the scientist said.
He said full-fledge production will be determined by how much companies are willing to spend on research to speed up development that can bring down overall production costs.
The KAIST team said it took two years to make the new zeolite, which can be custom made to meet specific needs.
(END)
2011.07.15 View 11485
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New Diagnosis System for Cardiovascular Disease Developed
Professor Park Hyun Kyu of the department of Biological-Chemical Engineering developed a new diagnosis system for diagnosing cardiovascular diseases using E.coli to test the homocysteine concentration in the blood.
The research team used the genetic recombination process to produce two different biologically illuminant nutrition cultures and compared the growth rate of the homocysteine between the two cultures by comparing the degree of luminescence.
The technology can allow the simultaneous analysis of blood samples en masse and is also economical and thus is being regarded as a major step forward in the field of homocysteine concentration analysis which is a rapidly growing field.
The conventional method used high performance liquid chromatography which took a long time to complete and was costly to run.
The advantage of the newly developed system is that it gets rid of costly steps as it only needs to grow E.coli and measure the luminescence of the naturally occurring illuminant.
The research was published as the cover paper of the April edition of ‘Analytical Chemistry’.
2011.05.11 View 8247
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Low Cost and Simple Gene Analysis Technology Developed
Professor Park Hyun Kyu of the Department of Biology and Chemical Engineering has developed a ‘real time CPR’ using Methylene Blue (nucleic acid bonding molecule with Electro-Chemical property).
The current gene analysis being used in the field is the real time PCR (Polymerase Chain Reaction) which takes advantage of the luminescent property of the gene and therefore requires expensive machines and chemicals to run.
By contrast, the electro-chemical method is easy to use and low cost and, most importantly, it allows the machine to become small and portable.
Professor Park’s research team used the decrease in the electro-chemical signal when the Methylene Blue reacts with nucleic acid and applied this to PCR which allowed for the real time analysis of the nucleic acid amplification process.
With the result of the experiment as the basis, the team was able to perform a trial with Chlamydia trachomatis, a pathogen that causes sexually transmitted disease.
The result showed that the electro-chemical method showed the same performance level as the real time PCR, which proved that the technology can be applied to diagnosing various diseases and gene research.
2011.04.30 View 9207
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Industrial Liaison Program Membership Implemented
KAIST implemented, for the first time as a Korean University, the Industrial Liaison Program Membership (ILPM).
ILPM is a structure where it does not limit the university as a minor technological counseling institute and encourages the university to provide expert services that the companies need in a proactive manner.
The ILPM is an Industry-Scholar Cooperative Model that offers companies with patents, technologies, labor force, research tools, and information to the companies all the while serving as the leader in research and development that will bring competitiveness to the company.
The first member of the ILPM at KAIST is ‘Yeul Chon’ Chemicals which is a subsidiary of the Nong-Shim Group and is a leading group in the field of high tech packaging, film and environmentally friendly materials.
KAIST and Yeul Chon Chemicals signed a MOU for technological cooperation and agreement to become a member of ILPM at KAIST on the 22nd of March.
With the agreement, the Yeul Chon Chemicals will now have access to all of KAIST’s information, technology, students, and counseling from professors.
2011.04.13 View 8961
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Artificial Spore Production Technology Developed
The core technology needed in the development of ‘biosensors’ so crucial in diagnosing illnesses or pathogens was developed by Korean research team.
KAIST’s Professor Choi In Seung of the department of Chemistry developed the technology that allows for the production of Artificial Spore by selectively coating a live cell.
In the field of engineering the problem in developing the next generation bio sensor, the cell based sensor, was that it was difficult to keep a cell alive without division for a long time. Once a cell is taken out of the body, it will either divide or die easily.
Professor Choi’s research team mimicked the spore, which has the capability to survive harsh conditions without division, and chemically coated a live cell and artificially created a cell similar to that of a spore.
The physical and biological stabilities of the cell increased by coating an artificial shell over the yeast cell. The shell is composed with a protein similar to that of the protein that gives mussels its stickiness. In addition by controlling the thickness of the shell, the division rate of the yeast can be controlled.
Professor Choi commented that this technology will serve as the basis for the single cell based biosensor.
The research was conducted together with Professor Lee Hae Shin of KAIST department of Chemistry and Professor Jeong Taek Dong of Seoul National University’s department of Chemistry and was published as the cover paper of ‘Journal of the American Chemical Society’.
2011.04.01 View 12063
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Explanation for the polymerized nucleic acid enzyme's abnormal activation found
KAIST’s Professor Park Hyun Kyu of the Department of Bio Chemical Engineering revealed on the 23rd of December 2010 that his team had successfully developed the technology that uses the metal ions to control the abnormal activation of nucleic acids’ enzymes and using this, created a logic gate, which is a core technology in the field of future bio electrons.
The polymerized nucleic acid enzyme works to increase the synthesis of DNA and kicks into action only when the target DNA and primers form complimentary pairs (A and T, C and G).
Professor Park broke the common conception and found that it is possible for none complimentary pairs like T-T and C-C to initiate the activation of the enzyme and thus increase the nucleic acid production, given that there are certain metal ions present.
What Professor Park realized is that the enzymes mistake the uncomplimentary T-T and C-C pairs (with stabilized structures due to the bonding with mercury and silver ions) as being complimentary base pairs. Professor Park described this phenomenon as the “illusionary polymerase activity.”
The research team developed a logic gate based on the “illusionary polymerase activity’ phenomenon.” The logic gate paves the way to the development of future bio electron needed for bio computers and high performance memories.
Professor Park commented, “The research is an advancement of the previous research carried on about metal ions and nucleic acid synthesis. Our research is the first attempt at merging the concepts of the two previously separately carried out researches and can be adapted for testing presence of metal ions and development of a new single nucleotide polymorphic gene analysis technology.”
Professor Park added that, “Our research is a great stride in the field of nano scale electron element research as the results made possible the formation of accurate logic gates through relatively cost efficient and simple system designs.”
On a side note, the research was funded by Korea Research Foundation (Chairman: Park Chan Mo) and was selected as the cover paper for the December issue of ‘Angewandte Chemie International Edition’.
2011.01.18 View 10192 -
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 10561 -
New Text Book on Chemistry Published by KAIST Professor and Student
A chemistry textbook written in English and Korean will aid Korean students to learn General Chemistry in a global academic setting.
Korean students majoring in chemistry and looking for an opportunity to study abroad will have a new, handy textbook that presents them with a practical introduction to an English speaking lecture on general chemistry.
Aiming for advanced Korean high school and college/university students, the inter-language textbook is written by two incumbent professors teaching chemistry at a university in Korea and the US. The book will help Korean students prepare for a classroom where various topics of general chemistry are presented and discussed in English. Clear, collated sections of English and Korean text provide the student with sufficient explanation of the rudimentary topics and concepts.
Composed of 15 chapters on the core subjects of General Chemistry, i.e., Stoichiometry and Chemical Reactions, Thermochemistry, Atomic Structure, and Bonding, the textbook includes essential English vocabulary and usage sections for each chapter; it also contains a pre-reading study guide on the subject that prepares the student for listening to a lecture. This section includes view-graph type slides, audio files, and follow-up questions the student can use to prepare for an English-speaking course. The various accompanying audio files are prepared to expose the student to English scientific dialogue and serve as examples for instruction at Korean secondary and tertiary schools.
The book was coauthored by Korean and American scientists: A father and son, who have taught chemistry at an American and Korean university, wrote the book. Professor Melvyn R. Churchill at the State University of New York at Buffalo and Professor David G. Churchill at KAIST prepared all of the technical English text which was adapted from General Chemistry course lecture notes; the text was further shaped by original perspectives arising from many student interactions and questions.
This English text was translated into Korean by Professor Kwanhee Lee from the Department of Life and Food Science at Handong Global University, who coauthored a previous preparatory book for Korean students in a different subject. He also supplied an important introductory section which serves as a general guide to the classroom student. Kibong Kim, a doctoral student in the Department of Chemistry at KAIST, helped in preparing the book as well.
“This has been definitely a collaborative undertaking with an international academic crew and it underscores that the Korean internationalization in science is mainstream. Professors and a Korean student created a new book for Korean consumption and benefit,” Professor David G. Churchill says.
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Bibliography: “How to Prepare for General Chemistry Taught in English” by David George Churchill, Melvyn Rowen Churchill, Kwanhee Lee & Kibong Kim, Darakwon Publishing, Paju, Republic of Korea, 2010, 400 pp, ISBN 978-89-5995-730-9 (1 Audio CD included)
2010.04.02 View 13709
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Prof. Lee"s Team Succeeds in Producing Plastics Without Use of Fossil Fuels
A team of scientists led by Prof. Sang-Yup Lee of the Department of Biological Sciences at KAIST have succeeded in producing the polymers used for everyday plastics through bioengineering, rather than through the use of fossil fuel based chemicals, the university authorities said on Tuesday (Nov. 24).
This groundbreaking research, which may now allow for the production of environmentally conscious plastics, has been published in two papers in the journal Biotechnology and Bioengineering.
Polymers are molecules found in everyday life in the form of plastics and rubbers. The team consisted of scientists from KAIST and Korean chemical company LG Chem focused their research on polylactic acid (PLA), a bio-based polymer which holds the key to producing plastics through natural and renewable resources.
"The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process," said Lee. "The idea of producing polymers from renewable biomass has attracted much attention due to the increasing concerns of environmental problems and the limited nature of fossil resources. PLA is considered a good alternative to petroleum based plastics as it is both biodegradable and has a low toxicity to humans."
Until now PLA has been produced in a two-step fermentation and chemical process of polymerization, which is both complex and expensive. Now, through the use of a metabolically engineered strain of E.coli, the team has developed a one-stage process which produces polylactic acid and its copolymers through direct fermentation. This makes the renewable production of PLA and lactate-containing copolymers cheaper and more commercially viable.
"By developing a strategy which combines metabolic engineering and enzyme engineering, we"ve developed an efficient bio-based one-step production process for PLA and its copolymers," said Lee. "This means that a developed E. coli strain is now capable of efficiently producing unnatural polymers, through a one-step fermentation process,"
This combined approach of systems-level metabolic engineering and enzyme engineering now allows for the production of polymer and polyester based products through direct microbial fermentation of renewable resources.
"Global warming and other environmental problems are urging us to develop sustainable processes based on renewable resources," concluded Lee. "This new strategy should be generally useful for developing other engineered organisms capable of producing various unnatural polymers by direct fermentation from renewable resources".
2009.11.30 View 14035 -
Prof. Woo's Team Discovers Eco-Friendly Solid-Oxide Fuel Cell System
A KAIST research team led by Prof. Seong-Ihl Woo of the Department of Chemical & Biomolecular Engineering has found a method to use glycerol, a byproduct from the production of biodiesel, as fuel for solid oxide fuel cells (SOFC), university authorities said on Tuesday (Oct. 27).
The research finding shows that glycerol can be an environmentally sustainable fuel when it is used for operating SOFCs with internal reforming, instead of hydrogen and methane. The finding was published in the Oct. 14, 2009 online edition of ChemSusChem, a sister journal of Angewandte Chemie, the world"s leading chemistry journal.
Biodiesel is an attractive alternative energy source because of its low sulfur content and demand is growing worldwide as oil price soars. Bio-derived glycerol will not contribute to the greenhouse effect and has the potential to contribute to reducing global warming.
Currently, glycereol is used as a raw material in the cosmetic, pharmacy, food, and tobacco industries. However, its supply exceeds its demand as the volume of biodiesel production increases. The production of 1 ton of biodiesel produces 0.1 ton of glycerol. Many researchers have investigated various routes for the consumption of surplus glycerol.
The research is expected to contribute to sustainable growth by reducing the emissions of carbon dioxide and reusing generated carbon dioxide for the production of biomass. The new method enables manufacturers to use glycerol as a fuel for operating SOFC.
2009.10.28 View 12463