research
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System Approach Using Metabolite Structural Similarity Toward TOM Suggested
A Korean research team at KAIST suggests that a system approach using metabolite structural similarity helps to elucidate the mechanisms of action of traditional oriental medicine.
Traditional oriental medicine (TOM) has been practiced in Asian countries for centuries, and is gaining increasing popularity around the world. Despite its efficacy in various symptoms, TOM has been practiced without precise knowledge of its mechanisms of action. Use of TOM largely comes from empirical knowledge practiced over a long period of time. The fact that some of the compounds found in TOM have led to successful modern drugs such as artemisinin for malaria and taxol (Paclitaxel) for cancer has spurred modernization of TOM.
A research team led by Sang-Yup Lee at KAIST has focused on structural similarities between compounds in TOM and human metabolites to help explain TOM’s mechanisms of action. This systems approach using structural similarities assumes that compounds which are structurally similar to metabolites could affect relevant metabolic pathways and reactions by biosynthesizing structurally similar metabolites.
Structural similarity analysis has helped to identify mechanisms of action of TOM. This is described in a recent study entitled “A systems approach to traditional oriental medicine,” published online in Nature Biotechnology on March 6, 2015. In this study, the research team conducted structural comparisons of all the structurally known compounds in TOM and human metabolites on a large-scale. As a control, structures of all available approved drugs were also compared against human metabolites. This structural analysis provides two important results. First, the identification of metabolites structurally similar to TOM compounds helped to narrow down the candidate target pathways and reactions for the effects from TOM compounds. Second, it suggested that a greater fraction of all the structurally known TOM compounds appeared to be more similar to human metabolites than the approved drugs. This second finding indicates that TOM has a great potential to interact with diverse metabolic pathways with strong efficacy. This finding, in fact, shows that TOM compounds might be advantageous for the multitargeting required to cure complex diseases. “Once we have narrowed down candidate target pathways and reactions using this structural similarity approach, additional in silico tools will be necessary to characterize the mechanisms of action of many TOM compounds at a molecular level,” said Hyun Uk Kim, a research professor at KAIST.
TOM’s multicomponent, multitarget approach wherein multiple components show synergistic effects to treat symptoms is highly distinctive. The researchers investigated previously observed effects recorded since 2000 of a set of TOM compounds with known mechanisms of action. TOM compounds’ synergistic combinations largely consist of a major compound providing the intended efficacy to the target site and supporting compounds which maximize the efficacy of the major compound. In fact, such combination designs appear to mirror the Kun-Shin-Choa-Sa design principle of TOM.
That principle, Kun-Shin-Choa-Sa (君臣佐使 or Jun-Chen-Zuo-Shi in Chinese) literally means “king-minister-assistant-ambassador.” In ancient East Asian medicine, treating human diseases and taking good care of the human body are analogous to the politics of governing a nation. Just as good governance requires that a king be supported by ministers, assistants and/or ambassadors, treating diseases or good care of the body required the combined use of herbal medicines designed based on the concept of Kun-Shin-Choa-Sa. Here, the Kun (king or the major component) indicates the major medicine (or herb) conveying the major drug efficacy, and is supported by three different types of medicines: the Shin (minister or the complementary component) for enhancing and/or complementing the efficacy of the Kun, Choa (assistant or the neutralizing component) for reducing any side effects caused by the Kun and reducing the minor symptoms accompanying major symptom, and Sa (ambassador or the delivery/retaining component) which facilitated the delivery of the Kun to the target site, and retaining the Kun for prolonged availability in the cells.
The synergistic combinations of TOM compounds reported in the literature showed four different types of synergisms: complementary action (similar to Kun-Shin), neutralizing action (similar to Kun-Choa), facilitating action or pharmacokinetic potentiation (both similar to Kun-Choa or Kun-Sa). Additional structural analyses for these compounds with synergism show that they appeared to affect metabolism of amino acids, co-factors and vitamins as major targets.
Professor Sang Yup Lee remarks, “This study lays a foundation for the integration of traditional oriental medicine with modern drug discovery and development. The systems approach taken in this analysis will be used to elucidate mechanisms of action of unknown TOM compounds which will then be subjected to rigorous validation through clinical and in silico experiments.”
Sources: Kim, H.U. et al. “A systems approach to traditional oriental medicine.” Nature Biotechnology. 33: 264-268 (2015).
This work was supported by the Bio-Synergy Research Project (2012M3A9C4048759) of the Ministry of Science, ICT and Future Planning through the National Research Foundation. This work was also supported by the Novo Nordisk Foundation.
The picture below presents the structural similarity analysis of comparing compounds in traditional oriental medicine and those in all available approved drugs against the structures of human metabolites.
2015.03.09 View 10772 -
The Real Time Observation of the Birth of a Molecule
From right to left: Dr. Kyung-Hwan Kim, Professor Hyotcherl Lhee, and Jong-Gu Kim, a Ph.D. candidate
Professor Hyotcherl Lhee of the Department of Chemistry at KAIST and Japanese research teams jointly published their research results showing that they have succeeded in the direct observation of how atoms form a molecule in the online issue of Nature on February 19, 2015.
The researchers used water in which gold atoms ([Au(CN) 2- ]) are dissolved and fired X-ray pulses over the specimen in femtosecond timescales to study chemical reactions taking place among the gold atoms. They were able to examine in real time the instant process of how gold atoms bond together to become a molecule, to a trimer or tetramer state.
This direct viewing of the formation of a gold trimer complex ([Au(CN) 2- ] 3 ) will provide an opportunity to understand complex chemical and biological systems.
For details, please see the following press release that was distributed by the High Energy Accelerator Research Organization, KEK, in Japan:
Direct Observation of Bond Formations
February 18, 2015
A collaboration between researchers from KEK, the Institute for Basic Science (IBS), the Korea Advanced Institute of Science and Technology (KAIST), RIKEN, and the Japan Synchrotron Radiation Research Institute (JASRI) used the SACLA X-ray free electron laser (XFEL) facility for a real time visualization of the birth of a molecular that occurs via photoinduced formation of a chemical bonds. This achievement was published in the online version of the scientific journal “Nature” (published on 19 February 2015).
Direct “observation” of the bond making, through a chemical reaction, has been longstanding dream for chemists. However, the distance between atoms is very small, at about 100 picometer, and the bonding is completed very quickly, taking less than one picosecond (ps). Hence, previously, one could only imagine the bond formation between atoms while looking at the chemical reaction progressing in the test-tube.
In this study, the research group focused on the process of photoinduced bond formation between gold (Au) ions dissolved in water. In the ground state (S 0 state in Fig. 1) Au ions that are weakly bound to each other by an electron affinity and aligned in a bent geometry. Upon a photoexcitation, the S 0 state rapidly converts into an excited (S 1 state in Fig. 1) state where Au-Au covalent bonds are formed among Au ions aligned in a linear geometry. Subsequently, the S 1 state transforms to a triplet state (T 1 state in Fig. 1) in 1.6 ps while accompanying further contraction of Au-Au bonds by 0.1 Å. Later, the T 1 state of the trimer converts to a tetramer (tetramer state in Fig. 1) on nanosecond time scale. Finally, the Au ions returned to their original loosely interacting bent structure.
In this research, the direct observation of a very fast chemical reaction, induced by the photo-excitation, was succeeded (Fig. 2, 3). Therefore, this method is expected to be a fundamental technology for understanding the light energy conversion reaction. The research group is actively working to apply this method to the development of viable renewable energy resources, such as a photocatalysts for artificial photosynthesis using sunlight.
This research was supported by the X-ray Free Electron Laser Priority Strategy Program of the MEXT, PRESTO of the JST, and the the Innovative Areas "Artificial Photosynthesis (AnApple)" grant from the Japan Society for the Promotion of Science (JSPS).
Publication: Nature , 518 (19 February 2015)
Title: Direct observation of bond formation in solution with femtosecond X-ray scattering
Authors: K. H. Kim 1 , J. G. Kim 1 , S. Nozawa 1 , T. Sato 1 , K. Y. Oang, T. W. Kim, H. Ki, J. Jo, S. Park, C. Song, T. Sato, K. Ogawa, T. Togashi, K. Tono, M. Yabashi, T. Ishikawa, J. Kim, R. Ryoo, J. Kim, H. Ihee, S. Adachi. ※ 1: These authors contributed equally to the work.
DOI: 10.1038/nature14163
Figure 1. Structure of a gold cyano trimer complex (Au(CN) 2 - ) 3 .
Figure 2. Observed changes in the molecular structure of the gold complex
Figure 3. Schematic view of the research of photo-chemical reactions by the molecular movie
2015.02.27 View 12786 -
KAIST Develops Subminiature, Power-Efficient Air Pollution Sensing Probe
Professor Inkyu Park and his research team from the Department of Mechanical Engineering at KAIST have developed a subminiature, power-efficient air-pollution sensing probe that can be applied to mobile devices. Their research findings were published online in the January 30th issue of Scientific Reports.
As air pollution has increased, people have taken greater interest in health care. The developed technology could allow people to measure independently the air pollution level of their surrounding environments.
Previous instruments used to measure air pollution levels were bulky and consumed a lot of power. They also often produced inaccurate results when measuring air pollution in which different toxic gases were mixed. These problems could not be resolved with existing semiconductor manufacturing process.
Using local temperature field control technology, Professor Park’s team succeeded in integrating multiple heterogeneous nanomaterials and fitting them onto a small, low-power electronic chip. This microheating sensor can heat microscale regions through local hydrothermal synthesis. Because it requires a miniscale amount of nanomaterials to manufacture, the sensor is most suitable for mobile devices.
Professor Park said, “Our research will contribute to the development of convergence technology in such field as air pollution sensing probes, biosensors, electronic devices, and displays.”
The team's research was supported by the Ministry of Education and the Ministry of Science, ICT and Future Planning, Republic of Korea.
Figure 1 – The Concept of Multiple Nanomaterial Device and Numerical Simulation Results of Precursor Solutions
Figure 2 - Multiple Nanomaterial Manufactured in a Microscale Region
2015.02.27 View 11031 -
News Article: Flexible, High-performance Nonvolatile Memory Developed with SONOS Technology
Professor Yang-Kyu Choi of KAIST’s Department of Electrical Engineering and his team presented a research paper entitled “Flexible High-performance Nonvolatile Memory by Transferring GAA Silicon Nanowire SONOS onto a Plastic Substrate” at the conference of the International Electron Devices Meeting that took place on December 15-17, 2014 in San Francisco.
The Electronic Engineering Journal (http://www.eejournal.com/) recently posted an article on the paper:
Electronic Engineering Journal, February 2, 2015
“A Flat-Earth Memory”
Another Way to Make the Brittle Flexible
http://www.techfocusmedia.net/archives/articles/20150202-flexiblegaa/?printView=true
2015.02.03 View 7887 -
Light Driven Drug-Enzyme Reaction Catalytic Platform Developed
Low Cost Dye Used, Hope for Future Development of High Value Medicinal Products to Treat Cardiovascular Disease and Gastric Ulcers
A KAIST research team from the Departments of Materials Science and Engineering and of Chemical and Biomolecular Engineering, led respectively by Professors Chan Beum Park and Ki Jun Jeong, has developed a new reaction platform to induce drug-enzyme reaction using light.
The research results were published in the journal Angewandte Chemie, International Edition, as the back cover on 12 January 2015.
Applications of this technology may enable production of high value products such as medicine for cardiovascular disease and gastric ulcers, for example Omeprazole, using an inexpensive dye.
Cytochrome P450 is an enzyme involved in oxidative response which has an important role in drug and hormone metabolism in organisms. It is known to be responsible for metabolism of 75% of drugs in humans and is considered a fundamental factor in new drug development.
To activate cytochrome P450, the enzyme must receive an electron by reducing the enzyme. In addition, NADPH (a coenzyme) needs to be present. However, since NADPH is expensive, the use of cytochrome P450 was limited to the laboratory and has not yet been commercialized.
The research team used photosensitizer eosin Y instead of NADPH to develop “Whole Cell Photo-Biocatalysis” in bacteria E. coli. By exposing inexpensive eosin Y to light, cytochrome P450 reaction was catalyzed to produce the expensive metabolic material.
Professor Park said, “This research enabled industrial application of cytochrome P450 enzyme, which was previous limited.” He continued, “This technology will help greatly in producing high value medical products using cytochrome P450 enzyme.”
The research was funded by the National Research Foundation of Korea and KAIST's High Risk High Return Project (HRHRP).
Figure 1: Mimetic Diagram of Electron Transfer from Light to Cytochrome P450 Enzyme via Eosin Y, EY
Figure 2: The back cover of Angewandte Chemie published on 12 January 2015, showing the research results
2015.01.26 View 10804 -
KAIST Develops a Method to Transfer Graphene by Stamping
Professor Sung-Yool Choi’s research team from KAIST's Department of Electrical Engineering has developed a technique that can produce a single-layer graphene from a metal etching. Through this, transferring a graphene layer onto a circuit board can be done as easily as stamping a seal on paper.
The research findings were published in the January 14th issue of Small as the lead article.
This technology will allow different types of wafer transfer methods such as transfer onto a surface of a device or a curved surface, and large surface transfer onto a 4 inch wafer. It will be applied in the field of wearable smart gadgets through commercialization of graphene electronic devices.
The traditional method used to transfer graphene onto a circuit board is a wet transfer. However, it has some drawbacks as the graphene layer can be damaged or contaminated during the transfer process from residue from the metal etching. This may affect the electrical properties of the transferred graphene.
After a graphene growth substrate formed on a catalytic metal substrate is pretreated in an aqueous poly vinyl alcohol (PVA) solution, a PVA film forms on the pretreated substrate. The substrate and the graphene layers bond strongly. The graphene is lifted from the growth substrate by means of an elastomeric stamp.
The delaminated graphene layer is isolated state from the elastomeric stamp and thus can be freely transferred onto a circuit board. As the catalytic metal substrate can be reused and does not contain harmful chemical substances, such transfer method is very eco-friendly.
Professor Choi said, “As the new graphene transfer method has a wide range of applications and allows a large surface transfer, it will contribute to the commercialization of graphene electronic devices.” He added that “because this technique has a high degree of freedom in transfer process, it has a variety of usages for graphene and 2 dimensional nano-devices.”
This research was sponsored by the Ministry of Science, ICT and Future Planning, the Republic of Korea.
Figure 1. Cover photo of the journal Small which illustrates the research findings
Figure 2. Above view of Graphene layer transferred through the new method
Figure 3. Large surface transfer of Graphene
2015.01.23 View 11530 -
Hierarchically-Porous Polymers with Fast Absorption
KAIST's Professor Myungeun Seo and his research team from the Graduate School of Nanoscience and Technology has developed a method to form micropores of less than 2 nanometers within porous polymers where 10 nanometers long mesopores connect like a net. The advantage of the porous polymers is fast absorption of molecules.
Porous polymers with micropores of less than 2 nanometers, like a zeolite, have a large surface area. They are used as a means to store hydrogen-based molecules or as a catalytic support that can be used as a surface to convert a material into a desired form. However, because the size of the pores in its path was too small for the molecules, it took a long time to spread into the pores and reach the surface.
To reach the surface efficiently, a lung cell or the vein of a leaf has a structure wherein the pores are subdivided into different sizes so that the molecule can spread throughout the organ. A technology that can create not only micropores but also bigger pores was necessary in order to create such structure.
The research team solved the issue by implementing a "self-assembly" of block polymers to easily form a net-like nanostructure from mesopores of 10 nanometers.
The team created hierarchically-porous polymers consisting of two different types of pores by using a hypercrosslinking reaction along with the "self-assembly" method. The reaction creates micropores within the chain after the polymer chain is confined by a chemical bond.
This porous polymer has micropores that are smaller than 2 nanometers on the walls of mesopores while 10 nanometers long mesopores forming 3-dimensional net structures. Because of the "self-assembly" method, the size of mesopores can be adjusted within the range of 6 to 15 nanometers.
This is the first case where a porous polymer has both well-defined mesopores and micropores. The research team verified the effect of hierarchically-porous structures on absorption of molecules by confirming that the porous polymer had faster absorption speeds than a polymer consisting only of micropores.
Professor Seo said, “The study has found a simple way to create different sizes of pores within a polymer.” He expected that the hierarchically-porous polymers can be used as a catalytic support in which fast diffusion of molecules is essential, or for molecule collection.
The research was sponsored by National Research Foundation of Korea and published online in the Journal of the American Chemical Society.
Figure 1 – Net-like Structure of Hierarchically-Porous Polymers with Mesopores and Micropores on the walls of Mesopores.
Figure 2 - Hierarchically-Porous Polymers
Figure 3 – Comparison of Porous-Polymers consisting of Mesopores only (left), and Mesopores and Micropores (right)
2015.01.13 View 8994 -
An Advanced Method of DNA Nanostructure Formation Developed
Professor Tae-Young Yoon’s research team from the Department of Physics at KAIST has developed a new method to form DNA nanostructures by using magnetic tweezers to observe and to induce the formation of the structure in real time.
Unlike traditional designs of "DNA origami" which relies on thermal or chemical annealing methods, the new technology utilizes a completely different dynamic in DNA folding. This allows the folding to be done within only ten minutes.
Developed in 2006, the "DNA origami" allows a long skeleton of DNA to be folded into an arbitrary structure by using small stapler DNA pieces. This has been a prominent method in DNA nanotechnology.
However, the traditional technology which adopts thermal processes could not control the DNA formation during the folding because every interaction among DNAs occurs simultaneously. Thus, the thermal processes, which take dozens of hours to complete, had to be repeated multiple times in order to find the optimal condition.
The research team designed a DNA folding using uni-molecular magnetic tweezers that applied force to a single DNA molecule while measuring the state of the DNA. Through this technology, they were able to induce the formation of DNA nanostructure and observe it at the same time.
During high temperature heat treatment, the first stage of conventional thermal processes, the internal structure of the long skeleton DNA untangles. To induce such state, after attaching one side of the skeleton DNA to the surface of glass and the other side to a magnetic material, the team unfolded the internal structure of the DNA by pulling the two sides apart with magnetic force.
Unlike the conventional thermal processes, this method lets the stapler DNA swiftly adhere to the skeleton DNA within a minute because the sites are revealed at room temperature.
After the stapler pieces connected to the skeleton, the team removed the magnetic force. Next, the structure folded through self-assembly as the stapler DNAs stuck to different sites on the skeleton DNA.
Professor Yoon said, “With the existing thermal methods, we could not differentiate the reactions of the DNA because the response of each DNA pieces mutually interacted with each other.” He added that “Using the magnetic tweezers, we were able to sort the process of DNA nanostructure formation into a series of reactions of DNA molecules that are well known, and shorten the time taken for formation in only ten minutes.”
He commented, “This nanostructure formation method will enable us to create more intricate and desirable DNA nanostructures by programming the folding of DNA origami structures.”
Conducted by Dr. Woori Bae under the guidance of Professor Yoon, the research findings were published online in the December 4th issue of Nature Communications.
Figure 1: Uni-molecular magnetic tweezers orchestrating the DNA nanostructure formation
Figure 2: The evolution of DNA nanostructure formation using magnetic tweezers. The DNA nanostructure with a 21-nanometer size was formed in about eight minutes.
2015.01.06 View 7557 -
A Key Signal Transduction Pathway Switch in Cardiomyocyte Identified
A KAIST research team has identified the fundamental principle in deciding the fate of cardiomyocyte or heart muscle cells. They have determined that it depends on the degree of stimulus in β-adrenergic receptor signal transduction pathway in the cardiomyocyte to control cells' survival or death. The findings, the team hopes, can be used to treat various heart diseases including heart failure.
The research was led by KAIST Department of Bio and Brain Engineering Chair Professor Kwang-Hyun Cho and conducted by Dr. Sung-Young Shin (lead author) and Ph.D. candidates Ho-Sung Lee and Joon-Hyuk Kang. The research was conducted jointly with GIST (Gwangju Institute of Science and Technology) Department of Biological Sciences Professor Do-Han Kim’s team. The research was supported by the Ministry of Science, ICT and Future Planning, Republic of Korea, and the National Research Foundation of Korea. The paper was published in Nature Communications on December 17, 2014 with the title, “The switching role of β-adrenergic receptor signalling in cell survival or death decision of cardiomyocytes.”
The β-adrenergic receptor signal transduction pathway can promote cell survival (mediated by β2 receptors), but also can result in cell death by inducing toxin (mediated by β1 receptors) that leads to various heart diseases including heart failure. Past attempts to identify the fundamental principle in the fate determining process of cardiomyocyte based on β-adrenergic receptor signalling concluded without much success.
The β-adrenergic receptor is a type of protein on the cell membrane of cardiomyocyte (heart muscle cell) that when stimulated by neurohormones such as epinephrine or norepinephrine would transduce signals making the cardiomyocyte contract faster and stronger.
The research team used large-scale computer simulation analysis and systems biology to identify ERK* and ICER** signal transduction pathways mediated by a feed-forward circuit as a key molecular switch that decides between cell survival and death.
Weak β-adrenergic receptor stimulations activate ERK signal transduction pathway, increasing Bcl-2*** protein expression to promote cardiomyocyte survival. On the other hand, strong β-adrenergic receptor stimulations activate ICER signal transduction pathway, reducing Bcl-2 protein expression to promote cardiomyocyte death.
Researchers used a systems biology approach to identify the mechanism of B-blocker****, a common drug prescribed for heart failure. When cardiomyocyte is treated with β1 inhibitor, strong stimulation on β-adrenergic receptor increases Bcl-2 expression, improving the chance of cardiomyocyte survival, a cell protection effect.
Professor Kwang-Hyun Cho said, “This research used systems biology, an integrated, convergence research of IT (information technology) and BT (biotechnology), to successfully identify the mechanism in deciding the fate of cardiomyocytes based on the β-adrenergic receptor signal transduction pathway for the first time. I am hopeful that this research will enable the control of cardiomyocyte survival and death to treat various heart diseases including heart failure.”
Professor Cho’s team was the first to pioneer a new field of systems biology, especially concerning the complex signal transduction network involved in diseases. Their research is focused on modelling, analyzing simulations, and experimentally proving signal pathways. Professor Cho has published 140 articles in international journals including Cell, Science, and Nature.
* ERK (Extracellular signal-regulated kinases): Signal transduction molecule involved in cell survival
** ICER (Inducible cAMP early repressor): Signal transduction molecule involved in cell death
*** Bcl-2 (B-cell lymphoma 2): Key signal transduction molecule involved in promotion of cell survival
**** β-blocker: Drug that acts as β-adrenergic receptor inhibitor known to slow the progression of heart failure, hence used most commonly in medicine.
Picture: A schematic diagram for the β-AR signalling network
2015.01.05 View 13981 -
How Science Understands the Beauty of Fine Arts from the Medieval Era to the 19th Century
A research team, consisting of Professor Hawoong Jeong of the Department of Physics at KAIST and Assistant Professor Seung-Woo Son of the Department of Applied Physics at Hanyang University, conducted a research project to understand visual representations through the eyes of science, i.e., quantitative analyses. Researchers took a sample of reproductions of European paintings from the 11th to the early 19th centuries and analyzed them based on three elements: the usage of color, the variety of painted colors, and the brightness of the images.
For the large-scale quantitative analysis, the research team utilized digital images of the paintings obtained from the Web Gallery of Art, a virtual museum and searchable database of European fine arts that includes over 29,000 pieces, ranging from the years 1000 to 1850. The Web Gallery classifies paintings into ten art historical periods such as Medieval, Renaissance, Mannerist, Baroque, Rococo, Romantic, and Realist.
For each period, researchers investigated the frequency of certain colors which appear in paintings and examined the variety of painted colors, paying particular attention to paintings created by two iconoclastic artists from different eras: Pieter Bruegel the Elder and Jackson Pollock. In their works, the researchers discovered that specific pigments were preferred in each period, the result of reflecting historical facts into fine arts. For example, certain rare colors were used in the medieval age for political and religious reasons, and artists in that era employed a technique to layer one color over another dry color in order to express mixed colors, resulting in thickly textured brushstrokes because they considered mixing colors impure. Moreover, oil colors and color mixing techniques were not fully developed until the Renaissance age.
According to the research team, fewer numbers of colors were used before the 20th century, and the introduction of new expressionist tools, like the use of pastels and fingers directly on canvas, and painting techniques, such as “chiaroscuro” and “sfumato,” made much more colorful and natural expressions possible after the Renaissance period. The team said that the color arrangement of Jackson Pollock’s drip paintings differed substantially from other paintings, showing randomness, especially in the spatial arrangement of colors.
Researchers also examined one of the artistic effects applied to paintings, contrast, an important element to express shape and space in two dimensional fine arts. Among various types of contrasts, they said, brightness contrast is the most important in art history due to the cultural background of Europe which usually adopts the contrast of light and darkness as a metaphorical expression. Taking the color information of pixels and their spatial arrangement, the researchers studied the prevalence of brightness contrast in European paintings over ten artistic periods by developing a correlation function to measure the contrast. These mathematical measurements quantitatively describe the birth of new painting techniques including chiaroscuro and sfumato and their increasing use. For instance, in the medieval age, the contour of objects or images in paintings was vague, but it became much clearer later in the Romantic period.
Professor Jeong said, “The complexity of the material world has been a long-lasting topic of interest in natural science, but research in the structural complexity of art and humanities has only begun since the development of the Internet, with the availability of big data in these fields. Our research is a meaningful attempt to understand the underling intricacy of art and humanities based on a scientific approach, expressed quantitatively.”
The research results were published online on December 11, 2014 in Scientific Reports, entitled “Large-Scale Quantitative Analysis of Painting Arts.” The paper was also selected as one of the weekly research highlights by Nature and is noted on its online journal’s website.
YouTube link on “the brightness contrast”: http://youtu.be/SFo0h1EU2aw
Figure 1: Constructing brightness surfaces and measuring roughness exponents
Figure 2: Visual representations of Mona Lisa painted by Leonardo da Vinci, which was reproduced in accordance with the art historical periods
Figure 3: The screenshot of Nature online webpage
2014.12.23 View 8852 -
KAIST Presents the Largest Number of Research Papers at the 2015 ISSCC
KAIST will present the largest number of research papers at the 2015 IEEE International Solid-State Circuits Conference (ISSCC), a leading global forum held every year to share professional knowledge and advancements in solid-state circuits and systems-on-a-chip. The Institute of Electrical and Electronics Engineers (IEEE) Solid-State Circuits Society sponsors the conference.
This year, the conference accepted 13 research papers from KAIST, ranking first among the participating organizations. Samsung Electronics Co., Ltd. took second (9 papers) place, and Intel Corporation and IMEC were in third place with 8 papers, respectively. A total of 610 papers were submitted, and reviewers selected only 206 papers for presentation at the next year's conference.
Since 2011, KAIST has been the number one institution among universities with the largest number of papers presented at the conference.
The Associate Chair of ISSCC Program Committee Chair, Professor Hoi-Jun Yoo of the Department of Electrical Engineering at KAIST, said, “Korea started the semiconductor industry in the 1970s, and since then, KAIST has been the center of research and development for the industry. With the establishment of IC (integrated circuit) Design Education Center in 1995, KAIST has contributed tremendously to the education and research of semiconductor production, nationally and globally. As shown from the record of presenting research results at the ISSCC, KAIST will continue to collaborate closely with the industry and lead the field.”
The 2015 IEEE ISSCC will take place on February 22-26, 2015 in San Francisco, CA, in the US.
2014.12.08 View 8544 -
Nanoparticle Cluster Manufacturing Technique Using DNA Binding Protein Developed
Professor Hak-Sung Kim of the Department of Biological Sciences at KAIST and Yiseul Ryu, a doctoral candidate, used the Zinc Finger protein that specifically binds to target DNA sequence to develop a new manufacturing technique for size-controllable magnetic Nanoparticle Clusters (NPCs). Their research results were published in Angewandte Chemie International Edition online on 25 November 2014.
NPCs are structures consisting of magnetic nanoparticles, gold nanoparticles, and quantum dots, each of which are smaller than 100 nm (10-9m). NPCs have a distinctive property of collectivity not seen in single nanoparticles.
Specifically NPCS differ in physical and optical properties such as Plasmon coupling absorbance, energy transfers between particles, electron transfers, and conductivity. Therefore, NPCs can be employed in biological and medical research as well as the development of nanoelectric and nanoplasmon devices.
To make use of these novel properties, the size and the composition of the cluster must be exquisitely controlled. However, previous techniques relied on chemical binding which required complex steps, making it difficult to control the size and composition of NPCs.
Professor Kim’s team used Zinc Finger, a DNA binding protein, to develop a NPCs manufacturing technique to create clusters of the desired size easily. The Zinc Finger protein contains a zinc ion and specifically recognizes DNA sequence upon binding, which allows the exquisite control of the size and the cluster composition. The technique is also bio-friendly.
Professor Kim’s team created linear structure of different sizes of NPCs using Zinc Finger proteins and three DNA sequences of different lengths. The NPCs they produced confirmed their ability to control the size and structure of the cluster by using different DNA lengths.
The NPCs showed tripled T2 relaxation rates compared to the existing MRI contrast media (Feridex) and effectively transported to targeted cells. The research findings show the potential use of NPCs in biological and medical fields such as MRI contrast media, fluorescence imaging, and drug transport.
The research used the specific binding property of protein and DNA to develop a new method to create an inorganic nanoparticle’s supramolecular assembly. The technique can be used and applied extensively in other nanoparticles for future research in diagnosis, imaging, and drug and gene delivery.
Figure 1. A Mimetic Diagram of NPCs Manufacturing Technique Using DNA Binding Protein Zinc Finger
Figure 2. Transmission Electron Microscopy Images showing different sizes of NPCs depending on the length of the DNA
2014.12.04 View 13409