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Autophagy in Dendritic Cells Helps Anticancer Activity
Autophagy contributes to the homeostasis of a cell and recently another function of autophagy has been reported. A KAIST research team found that the autophagy of dendritic cells supports T-cell anticancer activity. Autophagy is a process of maintaining cell homeostasis by removing cellular waste and damaged cellular organelles; nevertheless, its role in the presentation of phagocytized tumor-associated antigens remains vague. Meanwhile, dendritic cells are the ones that recognize pathogens or cancer antigens, and induce immune responses in T cells. When cancer cells are killed by radiation or an anticancer drug, dendritic cells absorb and remove them and present antigens on their surface to transfer them to T-cells. Professor Heung Kyu Lee from the Graduate School of Medical Science and Engineering and his team found that the autophagy of dendritic cells plays a key role in T-cell activation and they proposed the principles of enhancing anti-cancer effects. Their experiments showed that T-cell activation of dendritic cells as well as anticancer immune response dropped when there is a deficiency of Atg5 (autophagy-related) in dendritic cells. Interestingly, Atg5-deficient dendritic cells significantly elevated receptor CD36 on the surface of the cells, which increased the phagocytosis of apoptotic tumor cells yet restricted the activation of T-cells. At this time, when introducing antibodies into the system in order to block the receptor CD36, the anti-tumor T-cell response increased substantially while tumor growth declined. Professor Lee said, “This study allowed us to explore the role of autophagy in the anti-cancer immune response of T-cells. We look forward to developing targeted anti-cancer therapies using the receptor CD36.” This research was published in Autophagy (10.1080/15548627.2019.1596493) on March 22, 2019. Figure 1.Mechanism of autophagy in dendritic cells Figure 2. A role of autophagy in dendritic cells
2019.05.13
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The Embassy Day Builds the Global Presence of KAIST
(Photo caption: Diplomats and KAIST faculty pose at the Embassy Day KAIST hosted on June 23.) KAIST is stepping up its initiative for building global competitiveness. The Embassy Day hosted on June 23 will be a stepping stone to diversify its channels for promoting the global presence of KAIST. KAIST invited the foreign diplomatic corps from Seoul to share their successful journey to emerge as the world-class university. The event featured KAIST’s research highlights, academic experiences, and global environment through presentations by faculty and students. KAIST President Sung-Chul Shin said in his welcoming speech that he hopes for brains from around the world to come to KAIST and believes this event will serve as an opportunity to spread the global reputation of KAIST more widely. President Shin, who took office in March, ambitiously hosted this event for the first time, saying, “We didn’t expect this big of a response from the diplomats. The presence of this leading group of diplomats reflects how KAIST’s reputation has blossomed.” Nearly 100 diplomats from 65 countries attended the event held at the Grand Hyatt Seoul. Among the participants were ambassadors from 33 countries including Australian Amb. James Choi, Canadian Amb. Eric Walsh, and German Amb. Stephan Auer, reflecting the growing interest in the advancements in science and technology education and innovation in KAIST. The entire leadership team of KAIST turned out for the event including Provost O-Ok Park, Associate Vice President of the International Office Jay Hyung Lee, and Dean of Admissions Hayong Shin to provide an update on KAIST activities as well as admission policies, and make a new network with the foreign envoys. At the event, KAIST presented some of its latest research highlights that are gaining international acclaim. Professor Jun-ho Oh, director at the Humanoid Robot Research Center talked on the short history of the development of the KAIST humanoid robot, HUBO, which won the DARPA Robotics Challenge (DRC) in 2015. Distinguished Professor Sang-Yup Lee, dean of the KAIST Institute, which is the center of multidisciplinary research projects in KAIST, made a presentation on advances in metabolic engineering. In addition, Professor David Helfman of the Department of Biological Science shared his research on breast cancer and metastasis. Foreign students and faculty shared their experiences on becoming part of the KAIST community during the testimonial session. In particular, the story of Professor Jean-Charles Bazin of the Graduate School of Culture Technology was quite moving. Originally from France, Professor Bazin talked about his unique career path, starting as an exchange student at KAIST before settling down as a faculty member here. He cited the high caliber group of faculty as one of the reasons he completed his Ph.D. at KAIST. “Most of the faculty members are from top institutions in the US, Europe, and around the world, so they have very resourceful contacts with distinguished researchers and scholars abroad. That helped me make up my mind to choose KAIST,” he said. Currently, 179 foreign faculty and researchers from over 31 countries, representing 8.7% of the total faculty, are working at KAIST. Also, 710 foreign students from 86 countries, representing about 8% of the total students, are now studying at KAIST. President Shin continued, “In this complex global era, brains follow the best path to where they can reach their potential. KAIST is now gaining tremendous strength by becoming a magnet for talents from around the world. We would like to recruit these brains to create new knowledge with a global impact. Then we will become true global university with supremacy in research and education. President Shin said KAIST is gearing up for another round of innovation initiatives in education, convergence research, technology commercialization, future strategies, and globalization. He emphasized that globalization of the campus is a must for building up our global competitiveness. (Photo caption from the top: President Shin greets participant. Professor Oh explains the functions of the HUBO. Professor Helfman presents on his research of breast cancer and metastasis. KAIST a capella group showcases singing skills at the event. Participants meet and greet at the Embassy Day.)
2017.06.23
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Controlling Turtle Motion with Human Thought
KAIST researchers have developed a technology that can remotely control an animal’s movement with human thought. In the 2009 blockbuster “Avatar,” a human remotely controls the body of an alien. It does so by injecting human intelligence into a remotely located, biological body. Although still in the realm of science fiction, researchers are nevertheless developing so-called ‘brain-computer interfaces’ (BCIs) following recent advances in electronics and computing. These technologies can ‘read’ and use human thought to control machines, for example, humanoid robots. New research has demonstrated the possibility of combining a BCI with a device that transmits information from a computer to a brain, or known as a ‘computer-to-brain interface’ (CBI). The combination of these devices could be used to establish a functional link between the brains of different species. Now, researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed a human-turtle interaction system in which a signal originating from a human brain can affect where a turtle moves. Unlike previous research that has tried to control animal movement by applying invasive methods, most notably in insects, Professors Phill-Seung Lee of the Mechanical Engineering Department and Sungho Jo of the Computing School propose a conceptual system that can guide an animal’s moving path by controlling its instinctive escape behavior. They chose a turtle because of its cognitive abilities as well as its ability to distinguish different wavelengths of light. Specifically, turtles can recognize a white light source as an open space and so move toward it. They also show specific avoidance behavior to things that might obstruct their view. Turtles also move toward and away from obstacles in their environment in a predictable manner. It was this instinctive, predictable behavior that the researchers induced using the BCI. The entire human-turtle setup is as follows: A head-mounted display (HMD) is combined with a BCI to immerse the human user in the turtle’s environment. The human operator wears the BCI-HMD system, while the turtle has a 'cyborg system'—consisting of a camera, Wi-Fi transceiver, computer control module, and battery—all mounted on the turtle’s upper shell. Also included on the turtle’s shell is a black semi-cylinder with a slit, which forms the ‘stimulation device.’ This can be turned ±36 degrees via the BCI. The entire process works like this: the human operator receives images from the camera mounted on the turtle. These real-time video images allow the human operator to decide where the turtle should move. The human provides thought commands that are recognized by the wearable BCI system as electroencephalography (EEG) signals. The BCI can distinguish between three mental states: left, right, and idle. The left and right commands activate the turtle’s stimulation device via Wi-Fi, turning it so that it obstructs the turtle’s view. This invokes its natural instinct to move toward light and change its direction. Finally, the human acquires updated visual feedback from the camera mounted on the shell and in this way continues to remotely navigate the turtle’s trajectory. The research demonstrates that the animal guiding scheme via BCI can be used in a variety of environments with turtles moving indoors and outdoors on many different surfaces, like gravel and grass, and tackling a range of obstacles, such as shallow water and trees. This technology could be developed to integrate positioning systems and improved augmented and virtual reality techniques, enabling various applications, including devices for military reconnaissance and surveillance. *** Reference: “Remote Navigation of Turtle by Controlling Instinct Behavior via Human Brain-computer Interface,” Journal of Bionic Engineering, July 2016 (DOI: 10.1016/S1672-6529(16)60322-0) Depiction of Cyborg System A human controller influences the turtle’s escape behavior by sending left and right signals via Wi-Fi to a control system on the back of the turtle.
2017.02.21
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Nobel Laureate Dr. John Michael Kosterlitz Speaks at KAIST
KAIST’s Department of Physics will invite one of three co-recipients of the Nobel Prize in Physics 2016, Professor John Michael Kosterlitz of Brown University, on January 9, 2017, to speak about the exotic states of matter, which is entitled “Topological Defects and Phase Transitions.” Professor Kosterlitz shares the Nobel award with two other researchers, David Thouless and Duncan Haldane. He is considered one of the pioneers in the field of topological phases. In the early 1970s, along with Thouless, he demonstrated that superconductivity could occur at low temperatures and explained the mechanism behind, phase transition, that makes superconductivity disappear at higher temperatures. Over the last decade, topological materials and their applications have been widely studied with the hope of using them in new generations of electronics and superconductors, or in future quantum computers. Details of the lecture follow below: Distinguished Lecture Series by KAIST’s Physics Department · Speaker: Professor John Michael Kosterlitz of the Physics Department, Brown University · Topic: “Topological Defects and Phase Transitions” · Date: January 9, 2017, 4:00 PM · Place: Lecture Hall (#1501), College of Natural Sciences (E6-2)
2017.01.06
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Mystery of Biological Plastic Synthesis Machinery Unveiled
Plastics and other polymers are used every day. These polymers are mostly made from fossil resources by refining petrochemicals. On the other hand, many microorganisms naturally synthesize polyesters known as polyhydroxyalkanoates (PHAs) as distinct granules inside cells. PHAs are a family of microbial polyesters that have attracted much attention as biodegradable and biocompatible plastics and elastomers that can substitute petrochemical counterparts. There have been numerous papers and patents on gene cloning and metabolic engineering of PHA biosynthetic machineries, biochemical studies, and production of PHAs; simple Google search with “polyhydroxyalkanoates” yielded returns of 223,000 document pages. PHAs have always been considered amazing examples of biological polymer synthesis. It is astounding to see PHAs of 500 kDa to sometimes as high as 10,000 kDa can be synthesized in vivo by PHA synthase, the key polymerizing enzyme in PHA biosynthesis. They have attracted great interest in determining the crystal structure of PHA synthase over the last 30 years, but unfortunately without success. Thus, the characteristics and molecular mechanisms of PHA synthase were under a dark veil. In two papers published back-to-back in Biotechnology Journal online on November 30, 2016, a Korean research team led by Professor Kyung-Jin Kim at Kyungpook National University and Distinguished Professor Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) described the crystal structure of PHA synthase from Ralstonia eutropha, the best studied bacterium for PHA production, and reported the structural basis for the detailed molecular mechanisms of PHA biosynthesis. The crystal structure has been deposited to Protein Data Bank in February 2016. After deciphering the crystal structure of the catalytic domain of PHA synthase, in addition to other structural studies on whole enzyme and related proteins, the research team also performed experiments to elucidate the mechanisms of the enzyme reaction, validating detailed structures, enzyme engineering, and also N-terminal domain studies among others. Through several biochemical studies based on crystal structure, the authors show that PHA synthase exists as a dimer and is divided into two distinct domains, the N-terminal domain (RePhaC1ND) and the C-terminal domain (RePhaC1CD). The RePhaC1CD catalyzes the polymerization reaction via a non-processive ping-pong mechanism using a Cys-His-Asp catalytic triad. The two catalytic sites of the RePhaC1CD dimer are positioned 33.4 Å apart, suggesting that the polymerization reaction occurs independently at each site. This study also presents the structure-based mechanisms for substrate specificities of various PHA synthases from different classes. Professor Sang Yup Lee, who has worked on this topic for more than 20 years, said, “The results and information presented in these two papers have long been awaited not only in the PHA community, but also metabolic engineering, bacteriology/microbiology, and in general biological sciences communities. The structural information on PHA synthase together with the recently deciphered reaction mechanisms will be valuable for understanding the detailed mechanisms of biosynthesizing this important energy/redox storage material, and also for the rational engineering of PHA synthases to produce designer bioplastics from various monomers more efficiently.” Indeed, these two papers published in Biotechnology Journal finally reveal the 30-year mystery of machinery of biological polyester synthesis, and will serve as the essential compass in creating designer and more efficient bioplastic machineries. References: Jieun Kim, Yeo-Jin Kim, So Young Choi, Sang Yup Lee and Kyung-Jin Kim. “Crystal structure of Ralstonia eutropha polyhydroxyalkanoate synthase C-terminal domain and reaction mechanisms” Biotechnology Journal DOI: 10.1002/biot.201600648 http://onlinelibrary.wiley.com/doi/10.1002/biot.201600648/abstract Yeo-Jin Kim, So Young Choi, Jieun Kim, Kyeong Sik Jin, Sang Yup Lee and Kyung-Jin Kim. “Structure and function of the N-terminal domain of Ralstonia eutropha polyhydroxyalkanoate synthase, and the proposed structure and mechanisms of the whole enzyme” Biotechnology Journal DOI: 10.1002/biot.201600649 http://onlinelibrary.wiley.com/doi/10.1002/biot.201600649/abstract
2016.12.02
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KAIST Team Develops Flexible PRAM
Phase change random access memory (PRAM) is one of the strongest candidates for next-generation nonvolatile memory for flexible and wearable electronics. In order to be used as a core memory for flexible devices, the most important issue is reducing high operating current. The effective solution is to decrease cell size in sub-micron region as in commercialized conventional PRAM. However, the scaling to nano-dimension on flexible substrates is extremely difficult due to soft nature and photolithographic limits on plastics, thus practical flexible PRAM has not been realized yet. Recently, a team led by Professors Keon Jae Lee and Yeon Sik Jung of the Department of Materials Science and Engineering at KAIST has developed the first flexible PRAM enabled by self-assembled block copolymer (BCP) silica nanostructures with an ultralow current operation (below one quarter of conventional PRAM without BCP) on plastic substrates. BCP is the mixture of two different polymer materials, which can easily create self-ordered arrays of sub-20 nm features through simple spin-coating and plasma treatments. BCP silica nanostructures successfully lowered the contact area by localizing the volume change of phase-change materials and thus resulted in significant power reduction. Furthermore, the ultrathin silicon-based diodes were integrated with phase-change memories (PCM) to suppress the inter-cell interference, which demonstrated random access capability for flexible and wearable electronics. Their work was published in the March issue of ACS Nano: "Flexible One Diode-One Phase Change Memory Array Enabled by Block Copolymer Self-Assembly." Another way to achieve ultralow-powered PRAM is to utilize self-structured conductive filaments (CF) instead of the resistor-type conventional heater. The self-structured CF nanoheater originated from unipolar memristor can generate strong heat toward phase-change materials due to high current density through the nanofilament. This ground-breaking methodology shows that sub-10 nm filament heater, without using expensive and non-compatible nanolithography, achieved nanoscale switching volume of phase change materials, resulted in the PCM writing current of below 20 uA, the lowest value among top-down PCM devices. This achievement was published in the June online issue of ACS Nano: "Self-Structured Conductive Filament Nanoheater for Chalcogenide Phase Transition." In addition, due to self-structured low-power technology compatible to plastics, the research team has recently succeeded in fabricating a flexible PRAM on wearable substrates. Professor Lee said, "The demonstration of low power PRAM on plastics is one of the most important issues for next-generation wearable and flexible non-volatile memory. Our innovative and simple methodology represents the strong potential for commercializing flexible PRAM." In addition, he wrote a review paper regarding the nanotechnology-based electronic devices in the June online issue of Advanced Materials entitled "Performance Enhancement of Electronic and Energy Devices via Block Copolymer Self-Assembly." Picture Caption: Low-power nonvolatile PRAM for flexible and wearable memories enabled by (a) self-assembled BCP silica nanostructures and (b) self-structured conductive filament nanoheater.
2015.06.15
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Op-Ed by Professor David Helfman: Global Science and Education in Korea for the 21st Century
Professor David Helfman from the Department of Biological Sciences and Graduate School of Nanoscience and Technology contributed an op-ed, “Global Science and Education in Korea for the 21st Century, to the Korea Herald on February 20, 2013. For the article, please click the link below: http://www.koreaherald.com/view.php?ud=20130220000623.
2013.02.26
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Op-Ed by Prof. David Helfman: Global Science and Education in the 21st Century
Professor David Helfman from the Department of Biological Sciences and Graduate School of Nanoscience and Technology(https://sites.google.com/site/cellsignalinglaboratory/home) recently wrote an Op-Ed in the January 2013 issue of Journal of Happy Scientists and Engineers that ispublished by the Ministry of Science, Education and Technology, the Republic of Korea. In the article entitled “Global Science and Education in the 21st Century,” Professor Helfman addressed three important issues in science and education, which will have a great impact for the development of world-leading universities in Korea. For the article, please see the attachment.
2013.01.22
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Bio Pharmaceutical Business Center: Now Open
The Signboard Hanging Ceremony for the Bio Pharmaceutical Business Center for the Integrated Research for the field of Bio Pharmaceutics. 150 representatives from various bio pharmaceutics related businesses and institutes were present for this ceremony. The Ministry of Education, Science and Technology placed the Molecular Process research team, Personalized Drug Delivery Medium research team, and the newly formed Cancer Cell Detection using Blood research team at the Bio Pharmaceutical Business Center at KAIST.
2012.01.31
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Nature Photonics, a peer-reviewed scientific journal, released a paper written by a KAIST research team on the time-of-flight measurement.
Professor Seung-Woo Kim of the Mechanical Engineering Department, KAIST, and his research team published the result of their study on the measurement of 1 nanometer (nm) precision. “The time-of-flight of light pulses has long been used as a direct measure of distance, but state-of-the-art measurement precision using conventional light pulses or microwaves peaks at only several hundreds of micrometers. Here, we improve the time-of-flight precision to the nanometer regime by timing femtosecond pulses through phase-locking control of the pulse repetition rate using the optical cross-correlation technique,” Professor Kim said. According to the experiment conducted by the research team, “An Allan deviation of 117 nm in measuring a 700m distance in air at a sampling rate of 5 millisecond (ms) once the pulse repetition is phased-locked, which reduces to 7 nm as the averaging time increases to 1 second (s).” When measuring an object located in a far distance, a laser beam is projected to the object, and the reflected light is analyzed; the light is then converted into an electric signal to calculate the distance. In so doing, Professor Kim said, the conventional method of measurement creates at least 1 mm of deviation. He argues, “This enhanced capability is maintained at long range without periodic ambiguity, and is well suited to lidar applications. This method could also be applied to future space missions involving formation-flying satellites for synthetic aperture imaging and remote experiments related to general relativity theory." Nature Photonics published the article online on August 8, 2010.
2010.08.18
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KAIST Professor Exposes Structural Dynamics of Protein in Solution
-- Dr. Hyot-Cherl Ihee"s 3-Year Research Is Valuable in Pharmaceutical Application Prof. Hyot-Cherl Ihee and his team at the Department of Chemistry, KAIST, has successfully unveiled the structural dynamics of protein in solution as a result of more than three years" research work. Nature Methods, a sister publication of the authoritative science magazine Nature, published the treatise, titled "Tracking the structural dynamics of proteins in solution using time-resolved wide-angle X-ray scattering" in its Sept. 22 online edition. The research paper will be carried in the magazine"s printed version in its October edition, according to Dr. Lee who is its correspondence author. In May 2005, Prof. Ihee successfully photographed the structural dynamics of protein in solid state and his findings were published in the Proceedings of National Academy of Science of the United States. As protein normally exists in human body in solution, not in solid state, he directed his research to developing the technology to capture protein"s dynamics in resolved state. In July that year, Prof. Ihee succeeded in measuring the structural changes of simple organic molecules in real time. He further developed the technology to uncover the structural dynamics of hemoglobin, myoglobin and cytochrome C. Prof. Ihee"s research, helped with the Education-Science-Technology Ministry"s Creative Research Promotion Fund, can be applied to new pharmaceutical development projects as well as nanotechnology development, according to KAIST officials. Prof. Ihee who earned his doctorate at California Institute of Technology in 1994 began teaching at KAIST in 2003. He won the Young Scientist Award given by the Korean government in 2006.
2008.09.22
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Prof. Chung Named Winner of 2008 KAIST Scientific Award
Professor Chung Jong-Kyeong of the Department of Biological Sciences was named the winner of the 2008 KAIST Scientific Award. The prize was awarded by KAIST President Suh Nam-Pyo during the 37th KAIST anniversary ceremony on Feb. 16. Chung was cited for disclosing the new anti-cancer aspect of adenosine monophosphate-activated protein kinase (AMPK). His papers, published in the science magazine Nature in 2006 and again in 2007, revealed that the protein could be used to treat certain forms of cancer, as well as prevent malignant growths.
2008.02.28
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