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'KAIST the Most Innovative University in Asia-Pacific Region'
KAIST topped the most innovative universities ranking in the Asia and Pacific region for the second year in a row in 2017. Thomson Reuters released the second annual ranking of the Asia Pacific regions’ most innovative universities, a list that ranks the top 75 educational institutions doing the most to advance science and invent new technologies.
KAIST earned first place by producing a high volume of influential inventions. KAIST researchers submitted 923 patent filings from 2010 to 2015 and was the most cited in research papers, taking first place out of 75 top-ranked universities in the Asia and Pacific region. Those are key criteria in the rankings compiled in partnership with Clarivate Analytics. The Clarivate Analytics evaluates the institutions on 10 different metrics, focusing on academic paper citations and patent filings.
South Korean universities filled four out of the top five spots in the rankings and eight of the top 20 on the 2017 list. A total of 22 Korean universities were on the list of the top 75. Meanwhile 25 Chinese universities including Hong Kong, and 18 Japanese universities were listed in the rankings.
(Photo caption: Dr. Justin Kim (right), regional director of Clarivate Analytics Korea presents the plaque of the Most Innovative Univerisites in 2017 in Asia-Pacific region to President Sung-Chul Shin on June 15.)
2017.06.12 View 4429 -
KATT Tops at Appropriate Technology Competition
The KAIST Appropriate Technology Team (KATT) consisting of KAIST international students received gold and bronze awards at ‘the 9th Creative Design Competition for the Other 90%’. This year’s competition was hosted by the Ministry of Science, ICT and Future Planning at Seoul National University’s Global Convention Plaza on May 26. Undergraduate and graduate students nationwide formed 65 teams to participate in the competition.
The aim of the competition is to discover appropriate technology and sustainable design items to enhance quality of life for those with no or little access to science technology and its products around the world. This year’s competition categorized the designs into IT; water and energy; agriculture, hygiene, safety, and housing; and education. The teams were evaluated on their presentations and prototypes.
KATT produced alarm warning bracelets for people in developing countries and smart hybrid dryers for agricultural products. The alarm warning bracelets were designed for those living in tsunami risk zones; they use wireless communication technology to receive and transmit warning signals and can be produced for less than $4.
The smart hybrid dryers featured solar energy generation, aimed to help those with low income in subtropical, low-altitude regions with unstable climates, since there are currently no drying methods for agricultural products without direct exposure to sunlight. Therefore, the hybrid dryers allowed drying regardless of the weather, and thus increased the storage and distribution efficiency of agricultural products.
Ashar Alam from India who participated in developing the alarm warning bracelet said, “Through the appropriate technology club, I recognized problems in India that also affect neighboring countries such as Indonesia and Bangladesh. I wanted to actively use the science and technology knowledge I have accumulated in KAIST for the less fortunate.” He continued, “It was meaningful to develop the product using the respective talents of students from various countries with the spirit of developing appropriate technology.”
(Photo caption: Alarm warning bracelet team received the gold award)
2017.06.12 View 6701 -
Mutations Unveiled that Predispose Lung Cancer Cells to Refractory Histologic Transformation
Cancer pedigree analysis reveals the mutations in RB1 and TP53 genes play a key role in treatment-resistant, cancer cell-type transformation during EGFR inhibitor therapy for lung cancers.
Research led by Korean medical scientists has discovered that a specific type of drug resistance mechanism to EGFR inhibitor therapy in lung cancer is predisposed by mutations in two canonical cancer-related genes: RB1 and TP53. Published in Journal of Clinical Oncology on May 12, the study also found those mutations can be detectable in patients' tumors at the point of clinical diagnosis. Therefore, it can be used as strong markers in clinic for predicting poor outcome for the targeted treatment for lung adenocarcinoma.
Lung adenocarcinoma is the most common type of lung cancer, and about 15% of patients in Western countries and 50% of patients in Asian countries have mutations in the EGFR gene, which is critical for the development of lung cancer. Patients with lung adenocarcinoma harboring the EGFR mutation show favorable responses to EGFR inhibitors such as erlotinib (Tarceva) or gefitinib (Iressa), but ultimately relapse with drug-resistant tumors. Since the initial report in 2006, it has been known that in about 5~15% of patients, the lung adenocarcinoma cells undergo a mysterious transformation into a very different cancer cell type called “small cell lung cancer,” a much more aggressive lung cancer subtype, common in cigarette smokers.
To find out the genetic basis of this process, the researchers compared the genome sequences of multiple cancer tissues acquired during the treatment courses of patients whose tumors underwent small-cell transformation. They reconstructed the cancer cell pedigree by comparing mutations between cancer tissues, and identified that RB1 and TP53 genes are completely inactivated by mutations already in their lung adenocarcinoma tissues.
"We tried to compare the somatic mutational profile of pre-EGFR inhibitor treatment lung adenocarcinomas and post-treatment small cell carcinomas and to reconstruct the pedigrees of the cancer evolution in each patient. Strikingly, both copies of RB1 and TP53 genes were already inactivated at the stage of lung adenocarcinomas in all sequenced cases," said Dr. Jake June-Koo Lee, the first author from KAIST.
They further pursued the clinical implications of RB1 and TP53 inactivation by investigating 75 EGFR-mutated lung adenocarcinoma tissues from patients who received EGFR inhibitor therapy, including patients with small-cell transformation. In this analysis, the lung adenocarcinomas with a complete inactivation of both RB1 and TP53 genes tended to have a 43-times greater risk of transformation into small cell lung cancer during their EGFR inhibitor treatment courses.
Dr. Young Seok Ju, the co-last author from KAIST, explained, "This study shows the power of entire genome analyses to better understand the mechanisms underlying mysterious phenomenon encountered in clinic. Upon accurate bioinformatics, we are finding cancer-specific somatic mutations from the whole-genomes of patients’ cancer cells. These mutations allow us to track the evolution of cancer cells throughout the extraordinary clinical course of a special set of lung cancers."
The complete inactivation of both RB1 and TP53 tumor suppressor genes is found in a minor (<10%) subset of lung adenocarcinoma. This study suggests that the clinical course against targeted therapy is endogenously different for the cancers in the subgroup, and specific drug-resistance mechanisms are predisposed by the two genetic mutations. Indeed, RB1 and TP53 double inactivation is a genetic hallmark of primary small cell lung cancer, observed in nearly all cases.
"We are actively investigating patient tumor tissues to develop optimal surveillance plans and treatment options for patients with lung adenocarcinomas more prone to small-cell transformation," said Dr. Tae Min Kim, the co-last author from Seoul National University Hospital.
The researchers are implementing their findings into lung cancer clinics by screening the RB1 and TP53 mutational status in lung adenocarcinoma patients receiving EGFR inhibitor treatment, and following their treatment courses to develop a treatment strategy for those patients.
This research (doi.org/10.1200/JCO.2016.71.9096) was funded by the National Research Foundation of Korea (NRF-2013H1A2A1032691 to J.-K.L., NRF-2014R1A2A2A05003665 to Y.T.K.); Korea Institute of Science and Technology Information (K-16-L03-C02-S02 to J.L.); and the Korea Health Technology R&D Project through the Korea Health Industry Development Institute, which was funded by the Ministry of Health and Welfare (HI14C1234 to T.M.K., HI16C2387 to Y.S.J.)
Figure. Phylogeny analysis of serially-acquired tumors
A. Phylogeny trees of sequenced cases (LC1−LC4) are reconstructed from the WGS data. Conceptual illustrations are depicted with grey color. Circles indicate major clones of the tumors. The length of each branch is proportional to the number of mutations that occurred in the branch. Mutations of cancer-related genes in each branch are indicated with arrows. The time points of relevant treatments are summarized below the trees.
B. Mutations of RB1 and TP53 in two early LADCs (LC1b and LC4a) are visualized using Integrative Genomics Viewer (left panel). Allele-specific copy number analysis shows loss of heterozygosity of chromosomes 13 and 17 in both early LADCs and EGFR TKI-resistant SCLCs (right panel).
C. Clonal evolution of LC1 is described with clinical history and tumor volumes. The horizontal axis represents the time from the diagnosis (0), and the vertical axis indicates the volume of tumors calculated from the computed tomography images.
Abbreviations: LADC, lung adenocarcinoma; SCLC, small cell lung cancer
2017.06.07 View 8010 -
Bio-based p-Xylene Oxidation into Terephthalic Acid by Engineered E.coli
KAIST researchers have established an efficient biocatalytic system to produce terephthalic acid (TPA) from p-xylene (pX). It will allow this industrially important bulk chemical to be made available in a more environmentally-friendly manner.
The research team developed metabolically engineered Escherichia coli (E.coli) to biologically transform pX into TPA, a chemical necessary in the manufacturing of polyethylene terephthalate (PET). This biocatalysis system represents a greener and more efficient alternative to the traditional chemical methods for TPA production. This research, headed by Distinguished Professor Sang Yup Lee, was published in Nature Communications on May 31.
The research team utilized a metabolic engineering and synthetic biology approach to develop a recombinant microorganism that can oxidize pX into TPA using microbial fermentation. TPA is a globally important chemical commodity for manufacturing PET. It can be applied to manufacture plastic bottles, clothing fibers, films, and many other products. Currently, TPA is produced from pX oxidation through an industrially well-known chemical process (with a typical TPA yield of over 95 mol%), which shows, however, such drawbacks as intensive energy requirements at high temperatures and pressure, usage of heavy metal catalysts, and the unavoidable byproduct formation of 4-carboxybenzaldehyde.
The research team designed and constructed a synthetic metabolic pathway by incorporating the upper xylene degradation pathway of Pseudomonas putida F1 and the lower p-toluene sulfonate pathway of Comamonas testosteroni T-2, which successfully produced TPA from pX in small-scale cultures, with the formation of p-toluate (pTA) as the major byproduct. The team further optimized the pathway gene expression levels by using a synthetic biology toolkit, which gave the final engineered E. coli strain showing increased TPA production and the complete elimination of the byproduct.
Using this best-performing strain, the team designed an elegant two-phase (aqueous/organic) fermentation system for TPA production on a larger scale, where pX was supplied in the organic phase. Through a number of optimization steps, the team ultimately achieved production of 13.3 g TPA from 8.8 g pX, which represented an extraordinary yield of 97 mol%.
The team has developed a microbial biotechnology application which is reportedly the first successful example of the bio-based production of TPA from pX by the microbial fermentation of engineered E. coli. This bio-based TPA technology presents several advantages such as ambient reaction temperature and pressure, no use of heavy metals or other toxic chemicals, the removable of byproduct formation, and it is 100% environmentally compatible.
Professor Lee said, “We presented promising biotechnology for producing large amounts of the commodity chemical TPA, which is used for PET manufacturing, through metabolically engineered gut bacterium. Our research is meaningful in that it demonstrates the feasibility of the biotechnological production of bulk chemicals, and if reproducible when up-scaled, it will represent a breakthrough in hydrocarbon bioconversions.”
Ph.D. candidate Zi Wei Luo is the first author of this research (DOI:10.1038/ncomms15689).The research was supported by the Intelligent Synthetic Biology Center through the Global Frontier Project (2011-0031963) of the Ministry of Science, ICT & Future Planning through the National Research Foundation of Korea.
Figure: Biotransformation of pX into TPA by engineered E. coli.
This schematic diagram shows the overall conceptualization of how metabolically engineered E. coli produced TPA from pX. The engineered E. coli was developed through reconstituting a synthetic metabolic pathway for pX conversion to TPA and optimized for increased TPA yield and byproduct elimination. Two-phase partitioning fermentation system was developed for demonstrating the feasibility of large-scale production of TPA from pX using the engineered E. coli strains, where pX was supplied in the organic phase and TPA was produced in the aqueous phase.
2017.06.05 View 10279 -
Observation of the Phase Transition of Liquid Crystal Defects
KAIST researchers observed the phase transition of topological defects formed by liquid crystal (LC) materials for the first time.
The phase transition of topological defects, which was also the theme of the Nobel Prize for Physics in 2016, can be difficult to understand for a layperson but it needs to be studied to understand the mysteries of the universe or the underlying physics of skyrmions, which have intrinsic topological defects.
If the galaxy is taken as an example in the universe, it is difficult to observe the topological defects because the system is too large to observe some changes over a limited period of time. In the case of defect structures formed by LC molecules, they are not only a suitable size to observe with an optical microscope, but also the time period in which the phase transition of a defect occurring can be directly observed over a few seconds, which can be extended to a few minutes. The defect structures formed by LC material have radial, circular, or spiral shapes centering on a singularity (defect core), like the singularity that was already introduced in the famous movie "Interstellar,” which is the center point of black hole.
In general, LC materials are mainly used in liquid crystal displays (LCDs) and optical sensors because it is easy to control their specific orientation and they have fast response characteristics and huge anisotropic optical properties. It is advantageous in terms of the performance of LCDs that the defects of the LC materials are minimized. The research team led by Professor Dong Ki Yoon in the Graduate School of Nanoscience and Technology did not simply minimize such defects but actively tried to use the LC defects as building blocks to make micro- and nanostructures for the patterning applications. During these efforts, they found the way to directly study the phase transition of topological defects under in-situ conditions.
Considering the LC material from the viewpoint of a device like a LCD, robustness is important. Therefore, the LC material is injected through the capillary phenomenon between a rigid two-glass plate and the orientation of the LCs can be followed by the surface anchoring condition of the glass substrate. However, in this conventional case, it is difficult to observe the phase transition of the LC defect due to this strong surface anchoring force induced by the solid substrate.
In order to solve this problem, the research team designed a platform, in which the movement of the LC molecules was not restricted, by forming a thin film of LC material on water, which is like oil floating on water. For this, a droplet of LC material was dripped onto water and spread to form a thin film. The topological defects formed under this circumstance could show the thermal phase transition when the temperature was changed. In addition, this approach can trace back the morphology of the original defect structure from the sequential changes during the temperature changes, which can give hints to the study of the formation of topological defects in the cosmos or skyrmions.
Prof. Yoon said, “The study of LC crystal defects itself has been extensively studied by physicists and mathematicians for about 100 years. However, this is the first time that we have observed the phase transition of LC defects directly.” He also added, "Korea is leading in the LCD industry, but our basic research on LCs is not at the world's research level."
The first author of this study is Dr. Min-Jun Gimand supported by a grant from the National Research Foundation (NRF) and funded by the Korean Government (MSIP). The research result was published on May 30, 2017 in Nature Communications.
Figure 1. The phase transition of the LC topological defect on cooling.
Figure 2. Polarizing optical microscopy images of topological defects depending on the strength of the director field. (a,b,e) Convergent director field arrangements of LC molecules and corresponding schematic images; (c,d,f) Divergent director field arrangements of LC molecules and corresponding schematic images.
2017.06.02 View 8620 -
Augmented Reality Application for Smart Tour
‘K-Culture Time Machine,’ an augmented and virtual reality application will create a new way to take a tour. Prof. Woon-taek Woo's research team of Graduate School of Culture Technology of KAIST developed AR/VR application for smart tourism.
The 'K-Culture Time Machine' application (iOS App Store app name: KCTM) was launched on iOS App Store in Korea on May 22 as a pilot service that is targetting the Changdeokgung Palace of Seoul.
The application provides remote experience over time and space for cultural heritage or relics thorough wearable 360-degree video. Users can remotely experience cultural heritage sites with 360-degree video provided by installing a smartphone in a smartphone HMD device, and can search information on historical figures, places, and events related to cultural heritage. Also, 3D reconstruction of lost cultural heritage can be experienced.
Without using wearable HMD devices, mobile-based cultural heritage guides can be provided based on the vision-based recognition on the cultural heritages. Through the embedded camera in smartphone, the application can identify the heritages and provide related information and contents of the hertages. For example, in Changdeokgung Palace, a user can move inside the Changdeokgung Palace from Donhwa-Gate (the main gate of the Changdeokgung Palace), Injeong-Jeon(main hall), Injeong-Moon (Main gate of Injeong-Jeon), and to Huijeongdang (rest place for the king). Through the 360 degree panoramic image or video, the user can experience the virtual scene of heritages.
The virtual 3D reconstruction of the seungjeongwon (Royal Secretariat) which does not exist at present can be shown of the east side of the Injeong-Jeon The functions can be experienced on a smartphone without a wearable device, and it would be a commercial application that can be utilized in the field once the augmented reality function which is under development is completed.
Professor Woo and his research team constructed and applied standardized metadata of cultural heritage database and AR/VR contents. Through this standardized metadata, unlike existing applications which are temporarily consumed after development, reusable and interoperable contents can be made.Professor Woo said, "By enhancing the interoperability and reusability of AR contents, we will be able to preoccupy new markets in the field of smart tourism."
The research was conducted through the joint work with Post Media (CEO Hong Seung-mo) in the CT R&D project of the Ministry of Culture, Sports and Tourism of Korea. The results of the research will be announced through the HCI International 2017 conference in Canada this July.
Figure 1. 360 degree panorama image / video function screen of 'K-Culture Time Machine'. Smartphone HMD allows users to freely experience various cultural sites remotely.
Figure 2. 'K-Culture Time Machine' mobile augmented reality function screen. By analyzing the location of the user and the screen viewed through the camera, information related to the cultural heritage are provided to enhance the user experience.
Figure 3. The concept of 360-degree panoramic video-based VR service of "K-Culture Time Machine", a wearable application supporting smart tour of the historical sites. Through the smartphone HMD, a user can remotely experience cultural heritage sites and 3D reconstruction of cultural heritage that does not currently exist.
2017.05.30 View 10819 -
KAIST Alumni Take a Strong Hold on Tech-Based Startups
Average sales for KAIST alumni startups in 2015 doubled from the previous year to 20.7 billion KRW. They reportedly recorded approximately 37-times higher sales than non-KAIST alumni startups, demonstrating that KAIST is emerging as strong tech-based venture startup incubator.
According to a white paper on the Profile and Performance of KAIST Startups released recently, the number of KAIST startups stood 1,112, of which 877 were founded by alumni (78.9%), 36 by faculty and staff (3.2%), and 199 by those funded by the KAIST Technology Business Incubation Center (17.9%) at the end of 2015.
The total sales of KAIST startups stood at 13.6 trillion KRW in 2015, a 25% increase compared to the previous year. KAIST alumni startups created about 32,400 jobs in that year.
Most KAIST founders majored in engineering (649 people, 71.1%), followed by business (121 people, 13.3%), natural sciences (86, 9.4%), life science and bio engineering (32 people, 3.5%), and liberal arts and convergence science (24 people, 2.6%), making a total of 913 founders, excluding the 199 startups funded by KAIST Technology Business Incubation Center.
By department, most founders come from electrical engineering (148 people, 16.2%), followed by mechanical engineering (135 people, 14.8%), and computer science (114 people, 12.5%).
KAIST startups produced 63 listed companies (1 KOSPI, 51 KOSDAQ, and 11 KONEX), which accounted for 5.7% of the total 1112 startups. This is significantly higher than the average for venture companies (1.1%). It should be noted that the rate is only around 10% for Korean conglomerate-affiliated companies.
At the point of startup establishment, KAIST alumni startup founders were mostly in their 40s (430 people, 40%), followed by their 30s (415 people, 38.6%), 20s (110 people, 10.2%) and 50s (110 people, 10.2%). Around half of the founders were in their 20s and 30s. In particular, the number of founders in their 20s and 30s was around 3.5 times higher in KAIST startups compared to general startups and 1.2 times higher than venture startups.
The average lifespan of KAIST startups is 10.3 years; 276 companies (25%) were established over 16 years ago, 282 companies (25.4%) between 6 and 10 years, 246 companies (22.1%) between 11 and 15 years, and 308 companies (27.7%) less than five years ago. By type of business, startups based on technology accounted for 88.1%; 510 manufacturing companies accounted for 46.2%, followed by 321 information service companies with 29.1%, and 147 science and technology service companies with 13.3%.
By region, 617 companies (55.5%) were located in Seoul and the nearby metropolitan area, followed by 350 companies (31.5%) located in Daejeon.
2017.05.30 View 5667 -
The 2017 International Food Festival
The savory smell of exotic dishes filled the main plaza of the KAIST campus on May 26. Exotic music reverberated throughout the campus. The KAIST community took a break together on a breezy early summer Friday afternoon sharing food with their friends and family. KAIST international student body, KISA (KAIST International Students Association), installed white food tents and prepared their country’s favorite dishes at their 13th annual International Food Festival.
The festival was co-organized with Chungnam National University and the University of Science & Technology (UST). At the festival, students from 18 nations cooked about 60 dishes and sold them to the public. Foreign students’ performances of traditional dance and music on the stage livened the atmosphere.
KISA President Sanzhar Kerimbek of the Department of Chemical and Biomolecular Engineering said, “We are so glad to show the diversity of KAIST and its rich culture. This is a big opportunity to get together with neighboring universities, CNU and UST and say thank you for their participation and support." Valentin Porcellini, an exchange students from France in the School of Computing, said, “We are so excited to have people taste our crepes, ratatouille, and other dishes.”
Associate Vice President of the International Office Jay Hyung Lee also said he was glad to see so many people joining this festival. While congratulating the students on the success of the festival, he said the festival will serve as an opportunity to better understand each other by sharing the food and culture.
(Photo caption: Paricipants stop by the Indonesian booth to purchase the food at the International Food Festival on May 26.)
2017.05.29 View 5082 -
Extreme Materials for Fusion with Metal Cocktail
The research team under Professor Ryu Ho-jin of the Department of Nuclear and Quantum Engineering has developed a new material for facing fusion plasma environments using metal powder mixing technology. This technology is expected to extend the range of materials that can be designed for use in extreme environments such as in fusion power generators.
The durability of the tokamak vessel, which holds high-temperature plasma, is very important to create fusion power reactors, which are expected to be a future energy source. Currently, high-melting-point metals, such as tungsten, are considered plasma-facing materials to protect the tokamak vessel. However, high-energy thermal shocks, plasma ions, and neutrons are fatal to the plasma-facing material during high temperature fusion plasma operation. Therefore, it is necessary to develop new high-performance materials.
The ITER project, in which seven countries including the United States, the EU, and Korea participate jointly, is constructing a nuclear fusion experimental reactor in France with the goal of achieving the first plasma in 2025 and deuterium-tritium fusion operation in 2035. In Korea, the KSTAR tokamak at the National Fusion Research Institute has succeeded in maintaining high-performance plasma for 70 seconds.
Researchers in Europe, the United States, and China, who are leading the research on fusion plasma-facing materials, are studying the improvement of physical properties by adding a small amount of metal elements to tungsten. However, Professor Ryu’s team reported that by mixing various metals’ powders, including tungsten, they have succeeded in producing a new material that has twice the hardness and strength of tungsten. The difference in the atomic sizes of the well-mixed elements in the alloy is very significant because it makes it difficult to deform the alloy.
The team will continue its research to find alloying compositions that optimize mechanical properties as well as thermal conductivity, plasma interactions, neutron irradiation embrittlement, tritium absorption, and high-temperature oxidation properties.
Professor Ryu said, "Fusion plasma-facing materials are exposed to extreme environments and no metal is capable of withstanding thermal shock, plasma, and neutron damage simultaneously. As a result of this research, attempts to develop complex metallic materials for nuclear fusion and nuclear power are expected to become more active around the world. "
Ph.D. candidate Owais Ahmed Waseem is the first author of this project. The research is supported by the Ministry of Science, ICT and Future Planning, the Korea Research Foundation's Fusion Basic Research project, and the Engineering Research Center. The results were published in 'Scientific Report' on May 16.
Figure 1. Tungsten-based high strengh alloy sample
Figure 2. Fusion plasma facing material development by powder processing of refractory elements
2017.05.26 View 8506 -
Controlling 3D Behavior of Biological Cells Using Laser Holographic Techniques
A research team led by Professor YongKeun Park of the Physics Department at KAIST has developed an optical manipulation technique that can freely control the position, orientation, and shape of microscopic samples having complex shapes. The study has been published online in Nature Communications on May 22.
Conventional optical manipulation techniques called “optical tweezers,” have been used as an invaluable tool for exerting micro-scale force on microscopic particles and manipulating three-dimensional (3-D) positions of particles. Optical tweezers employ a tightly-focused laser whose beam diameter is smaller than one micrometer (1/100 of hair thickness), which can generate attractive force on neighboring microscopic particles moving toward the beam focus. Controlling the positions of the beam focus enabled researchers to hold the particles and move them freely to other locations so they coined the name “optical tweezers,” and have been widely used in various fields of physical and biological studies.
So far, most experiments using optical tweezers have been conducted for trapping spherical particles because physical principles can easily predict optical forces and the responding motion of microspheres. For trapping objects having complicated shapes, however, conventional optical tweezers induce unstable motion of such particles, and controllable orientation of such objects is limited, which hinder controlling the 3-D motion of microscopic objects having complex shapes such as living cells.
The research team has developed a new optical manipulation technique that can trap complex objects of arbitrary shapes. This technique first measures 3-D structures of an object in real time using a 3-D holographic microscope, which shares the same physical principle of X-Ray CT imaging. Based on the measured 3-D shape of the object, the researchers precisely calculates the shape of light that can stably control the object. When the shape of light is the same as the shape of the object, the energy of the object is minimized, which provides the stable trapping of the object having the complicated shape.
Moreover, by controlling the shape of light to have various positions, directions, and shapes of objects, it is possible to freely control the 3-D motion of the object and make the object have a desired shape. This process resembles the generation of a mold for casting a statue having desired shape so the researchers coined the name of the present technique “tomographic mold for optical trapping (TOMOTRAP).” The team succeeded in trapping individual human red blood cells stably, rotating them with desired orientations, folding them in an L-shape, and assembling two red blood cells together to form a new structure. In addition, colon cancer cells having a complex structure could be stably trapped and rotated at desired orientations. All of which have been difficult to be realized by the conventional optical techniques.
Professor Park said, “Our technique has the advantage of controlling the 3-D motion of complex shaped objects without knowing prior information about their shape and optical characteristics, and can be applied in various fields including physics, optics, nanotechnology, and medical science.”
Dr. Kyoohyun Kim, the lead author of this paper, noted that this technique can induce controlled deformation of biological cells with desired shapes. “This approach can be also applied to real-time monitoring of surgical prognosis of cellular-level surgeries for capturing and deforming cells as well as subcellular organelles,” added Kim.
Figure 1. Concept of optical manipulation techniques
Figure 2. Experimental setup
Figure 3. Research results
2017.05.25 View 7814 -
Total Synthesis of Flueggenine C via an Accelerated Intermolecular Rauhut-Currier Reaction
The first total synthesis of dimeric securinega alkaloid (-)-flueggenine C was completed via an accelerated intermolecular Rauhut–Currier (RC) reaction. The research team led by Professor Sunkyu Han in the Department of Chemistry succeeded in synthesizing the natural product by reinventing the conventional RC reaction.
The total synthesis of natural products refers to the process of synthesizing secondary metabolites isolated from living organisms in the laboratory through a series of chemical reactions. Each stage of chemical reaction needs to be successful to produce the final target molecule, and thus the process requires high levels of patience and creativity. For that reason, the researchers working on natural products total synthesis are often called “molecular artists”.
Despite numerous reports on the total synthesis of monomeric securinegas, the synthesis of dimeric securinegas, whose monomeric units are connected by a putative enzymatic RC reaction, has not been reported to date.
The team used a Rauhut-Currier (RC) reaction, a carboncarbon bond forming a reaction between two Michael acceptors first reported by Rauhut and Currier in 1963, to successfully synthesize a dimeric natural product, flueggenine C. This new work featured the first application of an intermolecular RC reaction in total synthesis.
The conventional intermolecular RC reaction was driven non-selectively by a toxic nucleophilic catalyst at a high temperature of over 150°C and a highly concentrated reaction mixture, and thus has never been applied to natural products total synthesis. To overcome this long-standing problem, the research team placed a nucleophilic moiety at the γ-position of the enone derivative. As a result, the RC reaction could be induced by the simple addition of a base at ambient temperature and dilute solution, without the need of a nucleophilic catalyst. Using this newly discovered reactivity, the team successfully synthesized the natural product (-)-flueggenine C from commercially available amino acid derivative in 12 steps.
Professor Han said, “Our key finding regarding the remarkably improved reactivity and selectivity of the intermolecular RC reaction will serve as a significant stepping stone in allowing this reaction to be considered a practical and reliable chemical tool with broad applicability in natural products, pharmaceuticals, and materials syntheses. ”
This research was led by Ph.D. candidate Sangbin Jeon and was published in The Journal of the American Chemical Society (JACS) on May 10. This research was funded by KAIST start-up funds, HRHR (High-Risk High-Return), RED&B (Research, Education, Development & Business) projects, the National Research Foundation of Korea, and the Institute for Basic Science.
(Figure 1: Representative dimeric/oligomeric securinega alkaloids)
(Figure 2: Our reinvented Rauhut-Currier reaction)
(Figure 3: Total Synthesis of (-)-flueggenine C)
2017.05.23 View 8312 -
2017 KAIST Research Day Honors Professor Hoon Sohn
The 2017 KAIST Research Day recognized Professor Hoon Sohn of the Department of Civil and Environmental Engineering as Research Grand Prize Awardee in addition to the 10 most distinguished research achievements of the past year.
The Research Grand Prize recognizes the professor whose comprehensive research performance evaluation indicator is the highest over the past five years. The indicator combines the factors of the number of research contracts, IPR, royalty income, as well as research overhead cost inclusion.
During the ceremony, which was held on May 23, Professor Jun-Ho Oh of the Department of Mechanical Engineering and Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering also won the Best Research Award. The two professors had the best scores when evaluating their research performance for one-year periods.
Meanwhile, the Research Innovation Award went to Professor YongKeun Park of the Department of Physics. The Research Innovation Award scores the factors of foreign patent registration, contracts of technological transfer and income from technology fees, technology consultations, and startups and selected Professor Park as the top winner.
Professors Yong Hee Lee of the Department of Physics and Jonghwa Shin of the Department of Material Science won the Convergence Research Award. The Convergence Research Award recognizes the most outstanding research team who created innovative research results for a year.
After the ceremony, President Chen Shiyi of the Southern University of Science and Technology gave a distinguished lecture on the “Global & Entrepreneurial Universities for the Age of the Fourth Industrial Revolution.” the Research Day ceremony, KAIST also presented the ten most distinguished research achievements made by KAIST professors during the last year as follows (Click):
▲ Commercialization of 3D Holographic Microscopy by Professor YongKeun Park of the Department of Physics
▲ Designer Proteins with Chemical Modifications by Professor Hee-Sung Park of the Department of Chemistry
▲ Lanthanum-Catalyzed Synthesis of Microporous 3D Graphene-Like Carbons in a Zeolite Template by Professor Ryong Ryoo of the Department of Chemistry
▲ Complete Prevention of Blood Loss by Self-Sealing Hemostatic Needles by Professor Haeshin Lee of the Department of Chemistry
▲ An Immunological Mechanism for the Contribution of Commensal Microbiota Against Herpes Simplex Virus Infection in Genital Mucosa by Heung Kyu Lee of the Graduate School of Medical Science and Engineering
▲ Development of a Pulse-Echo Laser Ultrasonic Propagation Imaging System by Professor Jung-Ryul Lee of the Department of Aerospace Engineering
▲ Bi-refractive Stereo Imaging for Single-Shot Depth Acquisition by Professor Min H. Kim of the School of Computing
▲ Development of Environment Friendly Geotechnical Construction Material Using Biopolymer by Professor Gye-Chun Cho of the Department of Civil and Environmental Engineering
▲ Protein Delivery Via Engineered Exosomes by Professor Chulhee Choi of the Department of Bio and Brain Engineering
▲ Hot Electron Detection Under Catalytic Reactions by Professor Jeong Young Park of the Graduate School of EEWS.
After the ceremony, President Chen Shiyi of the Southern University of Science and Technology gave a distinguished lecture on the “Global & Entrepreneurial Universities for the Age of the Fourth Industrial Revolution.”
(Photo:President Shin poses with the 2017 KAIST Research Grand Prize Winner Professor Hoon Sohn on May 23.)
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