NT
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Simple Molecular Reagents to Treat Alzheimer’s Disease
- Researchers report minimalistic principles for designing small molecules with multiple reactivities against dementia. -
Sometimes the most complex problems actually have very simple solutions. A group of South Korean researchers reported an efficient and effective redox-based strategy for incorporating multiple functions into simple molecular reagents against neurodegenerative disorders. The team developed redox-active aromatic molecular reagents with a simple structural composition that can simultaneously target and modulate various pathogenic factors in complex neurodegenerative disorders such as Alzheimer’s disease.
Alzheimer’s disease is one of the most prevalent neurodegenerative disorders, affecting one in ten people over the age of 65. Early-onset dementia also increasingly affects younger people.
A number of pathogenic elements such as reactive oxygen species, amyloid-beta, and metal ions have been suggested as potential causes of Alzheimer’s disease. Each element itself can lead to Alzheimer’s disease, but interactions between them may also aggravate the patient’s condition or interfere with the appropriate clinical care.
For example, when interacting with amyloid-beta, metal ions foster the aggregation and accumulation of amyloid-beta peptides that can induce oxidative stress and toxicity in the brain and lead to neurodegeneration.
Because these pathogenic factors of Alzheimer’s disease are intertwined, developing therapeutic agents that are capable of simultaneously regulating metal ion dyshomeostasis, amyloid-beta agglutination, and oxidative stress responses remains a key to halting the progression of the disease.
A research team led by Professor Mi Hee Lim from the Department of Chemistry at KAIST demonstrated the feasibility of structure-mechanism-based molecular design for controlling a molecule’s chemical reactivity toward the various pathological factors of Alzheimer’s disease by tuning the redox properties of the molecule.
This study, featured as the ‘ACS Editors’ Choice’ in the May 6th issue of the Journal of the American Chemical Society (JACS), was conducted in conjunction with KAIST Professor Mu-Hyun Baik’s group and Professor Joo-Young Lee’s group at the Asan Medical Center.
Professor Lim and her collaborators rationally designed and generated 10 compact aromatic molecules presenting a range of redox potentials by adjusting the electronic distribution of the phenyl, phenylene, or pyridyl moiety to impart redox-dependent reactivities against the multiple pathogenic factors in Alzheimer’s disease.
During the team’s biochemical and biophysical studies, these designed molecular reagents displayed redox-dependent reactivities against numerous desirable targets that are associated with Alzheimer’s disease such as free radicals, metal-free amyloid-beta, and metal-bound amyloid-beta.
Further mechanistic results revealed that the redox properties of these designed molecular reagents were essential for their function. The team demonstrated that these reagents engaged in oxidative reactions with metal-free and metal-bound amyloid-beta and led to chemical modifications. The products of such oxidative transformations were observed to form covalent adducts with amyloid-beta and alter its aggregation.
Moreover, the administration of the most promising candidate molecule significantly attenuated the amyloid pathology in the brains of Alzheimer’s disease transgenic mice and improved their cognitive defects.
Professor Lim said, “This strategy is straightforward, time-saving, and cost-effective, and its effect is significant. We are excited to help enable the advancement of new therapeutic agents for neurodegenerative disorders, which can improve the lives of so many patients.”
This work was supported by the National Research Foundation (NRF) of Korea, the Institute for Basic Science (IBS), and the Asan Institute for Life Sciences.
Image credit: Professor Mi Hee Lim, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of the news coverage of this paper only.
Publication:
Kim, M. et al. (2020) ‘Minimalistic Principles for Designing Small Molecules with Multiple Reactivities against Pathological Factors in Dementia.’ Journal of the American Chemical Society (JACS), Volume 142, Issue 18, pp.8183-8193. Available online at https://doi.org/10.1021/jacs.9b13100
Profile:
Mi Hee Lim
Professor
miheelim@kaist.ac.kr
http://sites.google.com/site/miheelimlab
Lim Laboratory
Department of Chemistry
KAIST
Profile:
Mu-Hyun Baik
Professor
mbaik2805@kaist.ac.kr
https://baik-laboratory.com/
Baik Laboratory
Department of Chemistry
KAIST
Profile:
Joo-Yong Lee
Professor
jlee@amc.seoul.kr
Asan Institute for Life Sciences
Asan Medical Center
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2020.05.11 View 15221 -
Professor Sukyung Park Named Presidential Science and Technology Adviser
Professor Sukyung Park from the Department of Mechanical Engineering was appointed as the science and technology adviser to the President Jae-in Moon on May 4. Professor Park, at the age of 47, became the youngest member of the president’s senior aide team at Chong Wa Dae.
A Chong Wa Dae spokesman said on May 4 while announcing the appointment, “Professor Park, a talent with a great deal of policymaking participation in science and technology, will contribute to accelerating the government’s push for science and technology innovation, especially in the information and communications technology (ICT) sector.”
Professor Park joined KAIST in 2004 as the first female professor of mechanical engineering. She is a biomechanics expert who has conducted extensive research on biometric mechanical behaviors. Professor Park is also a member of the KAIST Board of Trustees. Before that, she served as a senior researcher at the Korea Institute of Machinery and Materials (KIMM) as well as a member of the Presidential Advisory Council on Science and Technology.
After graduating from Seoul Science High School as the first ever two-year graduate, Professor Park earned a bachelor and master’s degrees in mechanical engineering at KAIST. She then finished her Ph.D. from the University of Michigan.
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2020.05.06 View 13343 -
Long Economic Depressions and Disparities Loom in the Wake of the COVID-19
"Global Cooperation for Managing Data Key to Mitigating the Impacts Around the World"
<Full recorded video of the GSI-IF2020>
The COVID-19 pandemic will lead to long economic depressions around the entire world. Experts predicted that the prevalent inequities among the countries, regions, and individuals will aggravate the economic crisis. However, crises always come with new opportunities and international cooperation and solidarity will help creating a new normal in the post-coronavirus era.
In a very basic but urgent step, global cooperation for managing data is the key to respond to COVID-19 since medicine and healthcare are intertwined with data science, said experts during an online international forum hosted by the Global Strategy Institute at KAIST on April 22.
KAIST launched its think-tank, the Global Strategy Institute (GSI), in February. The GSI aims to identify global issues proactively and help make breakthroughs well aligned with solid science-based policies.
The inaugural forum of the GSI focused on how the COVID-19 pandemic would impact socio-economic, scientific, and political landscapes, under the theme “Global Cooperation in the Coronavirus Era.”
In his opening remarks, KAIST President Sung-Chul Shin stressed that future global governance will be dominated by the power of science and technology. “If we can implement efficient policies together with troubleshooting technology for responding to future crises, we will emerge stronger than before,” he said.
President Shin said ‘the Korean model’, which is being recognized as a shining example for dealing with the pandemic, is the result of collaborations combining the creativity of the private sector, the public sector’s strong infrastructure, and the full support of the citizens. He added, “Without the technological prowess coming from the competent R&D power of Korea, we could not achieve these impressive results.”
“Creative collaboration among the private and public sectors, along with research universities from around the world, will help shore up global resilience against the epidemic. We should work together to build a world of growing prosperity,” President Shin said.
Prime Minister Sye-Kyun Chung, who is in charge of the Central Disaster and Safety Countermeasures Headquarters in Korea, stressed global solidarity in his welcoming remarks, saying that “We need to share information and rely on the strength of our connections, rather than retreating into nationalistic isolation.”
Peter Lee, Vice President of the Microsoft Healthcare, pointed out in his welcoming remarks three critical sectors for global cooperation: medicine and healthcare, public health and prevention, and life and the economy. He emphasized the rule of thumb for managing data, saying that data in these fields should be open, standardized, and shared among countries to combat this global pandemic.
During a keynote session, Director General of the International Vaccine Institute (IVI) Jerome Kim described the challenges that go along with developing a vaccine. Dr. Kim said that only 7% of vaccine candidates go through the clinical trial stages, and it will take five to 10 years to completely prove a new vaccine’s safety after completing three stages of clinical tests.
“It’s very challenging to develop the vaccine for COVID-19 within 12 to 15 months,” said Dr. Kim. He added that 78 out of 115 candidates are currently undergoing clinical trials around the world.
There are five groups, including Moderna, Inovio, Jenner Institute, CanSino, and the Beijing Institute of Biological Products, who are doing clinical trials in phases 1 and 2. “Given the fact that COVID-19 is a totally new type of virus, various stakeholders’ participation, such as the National Immunization Technical Advisory Groups, the WHO, and UNICEF, is needed to work together to benefit the entire world,” he pointed out.
Professor Edward Yoonjae Choi from the Graduate School of AI at KAIST shared how AI and data sciences are being utilized to interpret the major trends of the epidemic. His group mainly focuses on deep learning to model electronic health records (EHR) for disease predictions. Professor Choi said AI and machine learning would be crucial solutions and collaborative research projects will surely accelerate how quickly we can overcome the pandemic.
In addition, Dr. Kijung Shin’s group is interpreting the SIR (Susceptible, Infected, and Recovered) model in Korea to predict the number of infections and when people were infected. However, researchers noticed that they could not see the typical modeling in Korea for predicting the number of infections since the model disregarded the new variable of humans’ efforts to stop the spread the virus.
According to research by Professor Steven Whang’s group on social distancing and face mask distribution among vulnerable age groups, people in their 20s, 60s, and 70s followed the social distancing guidelines the most strictly. The research team analyzed the data provided by SK Telecom in the Gangnam district of Seoul. The data provided on people in their 70s, a group that accounted for half of all fatalities, showed that masks were generally well distributed nationwide.
Dr. Alexandros Papaspyrids, Tertiary Education Industry Director of the Asia region of Microsoft, said that despite all the disadvantages and problems related to remote education, we shouldn’t expect to return to the days before the COVID-19 any time soon. “We should accept the new normal and explore new opportunities in the new educational environment,” he said.
Hongtaek Yong, Deputy Minister at the Office of R&D Policy at the Ministry of Science and ICT presented the Korean government’s disease prevention and response policy and how they tried to mitigate the economic and social impact.
He stressed the government’s fast testing, tracing, and openness for successfully flattening the curve, adding that the government used an ICT-based approach in all aspects of their response. From early this year when the first patient was reported, the government aggressively encouraged the biotech industry to develop diagnostic kits and novel therapeutic medications.
As a result, five companies were able to produce genetic diagnostic reagents through the emergency approval. More notably, four of them are conducting massive R&D projects sponsored by the government and this is the result of the government’s continuous investment in R&D. Korea is the leader in R&D investment among the OECD countries.
According to Yong, the government’s big data project that was launched in 2017 continuously traces the trends of epidemics in Korea. The epidemiological studies based on the paths taken by suspected patients using credit card transaction made the difference in predicting the spread of the coronavirus and implementing countermeasures. The data has been provided to the Korea’s Center for Disease Control (CDC).
“In addition to the epidemics, we have so many other pending issues arising from digital and social equities, un-contact services, and job security. We are very open to collaborate and cooperate with other countries to deal with this global crisis,” Yong said.
During the subsequent panel discussions, David Dollar, a senior fellow at the Brookings Institution, said, “The global economy in the coronavirus era will not have a rapid V-shaped recovery, but rather will fall into a long depression for at least two years.” He pointed out that if countries practice protectionism like they did during the Great Depression, the recession will be even worse. Hence, he urged the international community, especially developed nations, to avoid protectionism, consider the economic difficulties of developing countries, and provide them with financial support.
Co-Director of the Center for Universal Education at the Brookings Institution Rebecca Winthrop raised concerns over the recent shift to online teaching and learning, claiming that insufficient infrastructures in low-income families in developing nations are already causing added educational disparities and provoking the inequity issue around the world. “The ways to provide quality education equally through faster and more effective means should be studied,” she said.
Professor Joungho Kim, the director of the KAIST GSI and the forum’s organizer, concluded the event by saying that this forum will be a valuable resource for everyone who is providing assistance to those in need, both during and after the COVID-19 pandemic.
(END)
2020.04.22 View 21206 -
14-Day Drawing Challenge Helps Maintain a Sense of Connection Amid Prolonged Social Distancing
- “You need space, but you also need connections.” -
Schools and workplaces have closed and people are staying at home around the globe. Governments across the world have urged their people to keep a distance from others as a measure to slow the spread of the pandemic.
With the Korean government’s decision to extend the intensive social distancing campaign until at least April 19, people in Korea are advised to avoid nonessential trips, public facilities, and social gatherings for another two weeks or so.
This unprecedented prolonged social distancing drive leads people to feel fatigue and frustration. Such emotional stress is worse for those who live alone in a foreign country.
The International Scholar and Student Services (ISSS) Team at KAIST has been working around the clock to build a dedicated COVID-19 Mental Health Support Service to support the university’s international community on campus and abroad and help get them connected online.
As the COVID-19 situation lingers, there has been a growing demand for mental health support from many KAIST international members including 299 students who have been staying in Korea on their own and away from their families, as well as from those who could not return to campus from their overseas homes.
In response to this, the KAIST ISSS Team has been offering some special online events and programs that can help the KAIST international community stay feeling connected whereever they are, while still keeping a safe distance from each other.
For instance, the team is running an art-therapy program called ‘The 14-day Drawing Challenge’ March 30 through April 12. This program is online and individual-based, so it does not require any physical contact between participants.
Each participant is asked to draw a picture at home using the daily topics previously set by the ISSS Team over 14 days. The topics include (Day 1) self-portrait, (Day 2) spring flowers, (Day 3) if you could become anything…, (Day 4) funniest memory you have, (Day 5) animals at KAIST, (Day 6) something you love, (Day 7) country or city you want to visit, (Day 8) what’s for dinner? (Day 9) person you miss, (Day 10) your favorite place at KAIST, (Day 11) your feeling today, (Day 12) things in your favorite color, (Day 13) song lyrics, and (Day 14) your future self in 10 years.
Once all 14 pieces have been completed, submissions can be made online by sending an e-mail to the ISSS Team after scanning or taking a photo of each drawing. Selected submissions will be awarded small prizes for participation and shared through the university’s official website and SNS channels.
“All the participants need is paper, coloring tools, and their creativity and imagination. They don’t have to be a great artist to join this challenge. There is no right or wrong or good or bad. They just need to have fun drawing every day for two weeks, ease their coronavirus anxiety, and remain emotionally stable just like they did back in the normal days,” said Su-yeon Ahn, the manager of the KAIST ISSS Team. She added, “In times like these, you need space, but you also need connections. Our team wants our international students, professors, and researchers to build strong connections with each other, even online.”
Katherine Michelle Pena Santana, an M.S. candidate from the Department of Industrial and Systems Engineering who is taking part in ‘The 14-day Drawing Challenge,’ looked back and said, “Lately with the new coronavirus spreading around Korea and the entire world, I was feeling very anxious. I didn't get out of my room and lived by just looking at the same walls and creating some kind of a psychological burden on myself.”
Santana added that these kinds of activities could give many foreign members of KAIST an opportunity to not only relieve fear and stress, but also share each other’s experiences dealing with this pandemic. She explained that this is why she decided to participate in this challenge.
An undergraduate student from the Department of Physics, Ada Carpenter, appreciated the KAIST ISSS Team’s efforts to provide a variety of special online mental health support services to help the university’s international community socialize, while strictly following the government’s guidelines for social distancing. She expressed excitement about participating and said, “I’m so looking forward to the challenge of things that I wouldn’t normally draw.”
< Short Self-interview Video Clip Filmed by Ada Carpenter >
The COVID-19 Mental Health Support Service by the KAIST ISSS Team will be continually updated with new information and enhanced with other tools and support over the coming weeks and months. Some of the upcoming events and programs include ‘The Online Guitar Lessons’, ‘The Growing Houseplants Challenge’, and ‘The Any Song Challenge*’.
* The song titled “Any Song” by Korean rapper Zico has been gaining attention on social media thanks to many celebrities taking on the ‘Any Song Challenge’, performing a short dance to the chorus of the song and sharing it on social media.
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2020.04.08 View 10520 -
Former Minister of Science and Technology Woo Sik Kim Elected as New Chairman of Board of Trustees
Dr. Woo Sik Kim, former Minister of Science and Technology and Deputy Prime Minister, was elected as the new chairman of the KAIST Board of Trustees on March 26. Dr. Kim will succeed Chairman Jang-Mu Lee, whose three-year term expired last month.
Dr. Kim is a chemical engineering professor who spent most of his academic career at Yonsei University from 1968. In 2000, he held the office of president of Yonsei University for four years before moving to the Presidential Office of President Roh Moo-Hyun as his chief of staff in 2004. After serving in the Blue House for two years, he served as the Minister of Science and Technology from 2006 to 2008.
An emeritus fellow of the National Academy of Engineering of Korea (NAEK), Chairman Kim also taught at KAIST as an invited distinguished professor from 2008 to 2010. He is currently the chairman of the Creativity Engineering Institute (CEI).
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2020.04.06 View 12169 -
Cyber MOU Signing with Zhejiang University
KAIST signed an MOU with Zhejiang University (ZJU) in China on March 25. This MOU signing ceremony took place via video conference due to the outbreak of COVID-19.
The collaboration with ZJU had already started with the signing of an MOU for cooperation in technology commercialization last December. Possible cooperation initiatives included facilitating joint start-up businesses, patent portfolios, and technology marketing.
With this general agreement signing, it is expected that the two institutes will expand mutual exchanges and collaborations at the institutional level for education and research.
President Sung-Chul Shin said, “We will work together to devise measures for the systematic advancement of cooperation in various directions, including education, research, and the commercialization of technologies.”
ZJU, a member of the C9 League known as China’s Ivy League, was established in 1897 and is located in the city of Hangzhou. Its population across 37 colleges and schools comprises 54,641 students and 3,741 faculty members. The university was ranked 6th in Asia and 54th in the world in the 2020 QS Rankings.
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2020.03.30 View 12845 -
Highly Efficient and Stable Double Layer Solar Cell Developed
Solar cells convert light into energy, but they can be inefficient and vulnerable to the environment, degrading with, ironically, too much light or other factors, including moisture and low temperature. An international research team has developed a new type of solar cell that can both withstand environmental hazards and is 26.7% efficient in power conversion.
They published their results on March 26 in Science.
The researchers, led by Byungha Shin, a professor from the Department of Materials Science and Engineering at KAIST, focused on developing a new class of light-absorbing material, called a wide bandgap perovskite. The material has a highly effective crystal structure that can process the power needs, but it can become problematic when exposed to environmental hazards, such as moisture. Researchers have made some progress increasing the efficiency of solar cells based on perovskite, but the material has greater potential than what was previously achieved.
To achieve better performance, Shin and his team built a double layer solar cell, called tandem, in which two or more light absorbers are stacked together to better utilize solar energy. To use perovskite in these tandem devices, the scientists modified the material’s optical property, which allows it to absorb a wider range of solar energy. Without the adjustment, the material is not as useful in achieving high performing tandem solar cells. The modification of the optical property of perovskite, however, comes with a penalty — the material becomes hugely vulnerable to the environment, in particular, to light.
To counteract the wide bandgap perovskite’s delicate nature, the researchers engineered combinations of molecules composing a two-dimensional layer in the perovskite, stabilizing the solar cells.
“We developed a high-quality wide bandgap perovskite material and, in combination with silicon solar cells, achieved world-class perovskite-silicon tandem cells,” Shin said.
The development was only possible due to the engineering method, in which the mixing ratio of the molecules building the two-dimensional layer are carefully controlled. In this case, the perovskite material not only improved efficiency of the resulting solar cell but also gained durability, retaining 80% of its initial power conversion capability even after 1,000 hours of continuous illumination. This is the first time such a high efficiency has been achieved with a wide bandgap perovskite single layer alone, according to Shin.
“Such high-efficiency wide bandgap perovskite is an essential technology for achieving ultra-high efficiency of perovskite-silicon tandem (double layer) solar cells,” Shin said. “The results also show the importance of bandgap matching of upper and lower cells in these tandem solar cells.”
The researchers, having stabilized the wide bandgap perovskite material, are now focused on developing even more efficient tandem solar cells that are expected to have more than 30% of power conversion efficiency, something that no one has achieved yet,
“Our ultimate goal is to develop ultra-high-efficiency tandem solar cells that contribute to the increase of shared solar energy among all energy sources,” Shin said. “We want to contribute to making the planet healthier.”
This work was supported by the National Research Foundation of Korea, the Korea Institute of Energy Technology Evaluation and Planning, the Ministry of Trade Industry and Energy of Korea, and the U.S. Department of Energy.
Other contributors include Daehan Kim, Jekyung Kim, Passarut Boonmongkolras, Seong Ryul Pae and Minkyu Kim, all of whom affiliated with the Department of Materials Science and Engineering at KAIST. Other authors include Byron W. Larson, Sean P. Dunfield, Chuanxiao Xiao, Jinhui Tong, Fei Zhang, Joseph J. Berry, Kai Zhu and Dong Hoe Kim, all of who are affiliated with the National Renewable Energy Laboratory in Colorado. Dunfield is also affiliated with the Materials Science and Engineering Program at the University of Colorado; Berry is also affiliated with the Department of Physics and the Renewable and Sustainable Energy Institute at the University of Colorado Boulder; and Kim is also affiliated with the Department of Nanotechnology and Advanced Materials Engineering at Sejong University. Hee Joon Jung and Vinayak Dravid of the Department of Materials Science and Engineering at Northwestern University; Ik Jae Park, Su Geun Ji and Jin Young Kim of the Department of Materials Science and Engineering at Seoul National University; and Seok Beom Kang of the Department of Nanotechnology and Advanced Materials Engineering of Sejong University also contributed.
Image credit: Professor Byungha Shin, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only.
Publication: Kim et al. (2020) “Efficient, stable silicon tandem cells enabled by anion-engineered wide band gap perovskites”. Science. Available online at https://doi.org/10.1126/science.aba3433
Profile:
Byungha Shin
Professor
byungha@kaist.ac.kr
http://energymatlab.kaist.ac.kr/
Department of Materials Science and Engineering
KAIST
Profile:
Daehan Kim
Ph.D. Candidate
zxzx4592@kaist.ac.kr
http://energymatlab.kaist.ac.kr/
Department of Materials Science and Engineering
KAIST
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2020.03.27 View 20303 -
COVID-19 Update: Students and Professors Adjust to 1,200 Online Classes
- Approximately 1,200 online classes are being offered during the cyber semester. -
COVID-19 is transforming the way KAISTians live. Many restrictions imposed to contain the spread of the virus have us adjusting to a new environment swiftly. A cyber MOU signing ceremony with a foreign partner university took place on March 25, as did a cyber Board of Trustees Meeting on March 26. KAIST’s Main Campus is normally one of the most iconic picnic destinations for the citizens of Daejeon, but this is not the case this spring, as the campus has been temporarily closed to protect our own community as well as our neighboring communities.
KAIST has been offering approximately 1,200 courses remotely since this semester opened on March 16 and will do so until further notice. Students and faculty members are experiencing the newly emerging norms of remote education in this time of social distancing. This unexpected disruption might advance the new digital pedagogy at KAIST, which was already ahead of the curve with its online learning and teaching infrastructure.
Professor Youngsun Kwon, the Dean of KAIST Academy and the Director of the Center for Excellence in Learning and Teaching, said, “We had already initiated the KAIST Learning Management System (KLMS) in 2011 for introducing flipped learning, a student-centric creative-learning pedagogy. Since then, about nine percent of all our classes have been run using this methodology. Students pre-study the online streaming lecture materials that professors have uploaded in advance outside the classroom, and in-class activities are mainly group discussions and problem-solving activities.”
According to Dean Kwon, the university was planning to further introduce real-time online education from this spring semester and were in the process of setting up the system started from last year. “Our plan was to connect the real-time video conferencing service Zoom to our existing remote educational platform KLMS. However, things related to COVID-19 all happened so rapidly that we didn’t yet have a full-fledged connection,” said Dean Kwon.
Professors had to choose either to conduct their lectures remotely in the form of a pre-made one-way lesson or a real-time two-way lesson. They could also modify them using both platforms. Professor Youngchul Kim from the Department of Civil and Environmental Engineering said, “I had to also make some changes in my class activities and assignments. I removed a group design project and some tutorial workshops that were meant to provide students with hands-on experience using design tools such a 3D printer and a laser cutting system. Ironically, I found that students seem to focus on online lectures more intensely than I expected. I feel like students give me their thoughts and respond much quicker as well.”
Unfortunately, the online learning and teaching infrastructure and resources that had been put in place could not handle the overwhelming volume of classes being uploaded over very short period of time.
To handle the new demand, IT technicians are setting up the technical environment with stable servers to improve network traffic. For professors, teaching assistants, and students to teach and learn better in an online space, department offices have been lending spare equipment such as laptops, tablets, headsets, and webcams to those who do not have their own, based on availability. Academic support staff have also been pitching in by developing the best guidelines for online training.
“Even in these uncharted waters, all of the members of KAIST are doing their best to keep the ship steadily sailing in the right direction. I am very grateful for everyone’s efforts to make things work,” said Dean Kwon.
About 60% of the courses currently offered online are being uploaded using the non-real-time KLMS, and the remaining 40% are run in real time via Zoom. Each class runs for 50 minutes per academic credit, and comprises at least 25 minutes of lecture, a Q&A session, and a group discussion.
Students enrolled in the 481 courses that include experiments are asked to conduct their experiments individually after watching a 50-minute online lecture. Experimental, practical, and physical courses that are impossible to provide online have been cancelled or postponed until the next semester or summer/winter breaks.
“I find the online lessons quite convenient for the courses that I am taking this semester, especially the non-real-time ones, because I can watch the lecture videos over and over again even after the class has finished to understand the contents better,” said Jaymee Palma, an undergraduate student from the Department of Chemistry.
Ada Carpenter, an undergraduate student from the Department of Physics, added, “Students who normally feel uncomfortable speaking in class raise their questions on an online Q&A board more easily. Besides, I saw many other students asking questions and leading a discussion verbally as well. I think, when students join a synchronous Zoom classroom, they are more engaged than when just attending a regular lecture in a conventional classroom. It’s like everyone can sit in the front row of the class.”
Still, there are reportedly pedagogical, logistical, and technological challenges to these extraordinary educational measures. Some students express concerns about keeping up with professors and other students if they don’t have sufficient technological knowledge and skills. Some also cite the disadvantage of online classes having much less interaction and engagement among students and between professors and students than offline ones. “Fortunately, I think my professors are all excellent, so I can immerse myself well during all my cyber classes,” said Sang-Hyeon Lee, a graduate student from the School of Computing.
(END)
2020.03.26 View 9318 -
Ultrathin but Fully Packaged High-Resolution Camera
- Biologically inspired ultrathin arrayed camera captures super-resolution images. -
The unique structures of biological vision systems in nature inspired scientists to design ultracompact imaging systems. A research group led by Professor Ki-Hun Jeong have made an ultracompact camera that captures high-contrast and high-resolution images. Fully packaged with micro-optical elements such as inverted micro-lenses, multilayered pinhole arrays, and gap spacers on the image sensor, the camera boasts a total track length of 740 μm and a field of view of 73°.
Inspired by the eye structures of the paper wasp species Xenos peckii, the research team completely suppressed optical noise between micro-lenses while reducing camera thickness. The camera has successfully demonstrated high-contrast clear array images acquired from tiny micro lenses. To further enhance the image quality of the captured image, the team combined the arrayed images into one image through super-resolution imaging.
An insect’s compound eye has superior visual characteristics, such as a wide viewing angle, high motion sensitivity, and a large depth of field while maintaining a small volume of visual structure with a small focal length. Among them, the eyes of Xenos peckii and an endoparasite found on paper wasps have hundreds of photoreceptors in a single lens unlike conventional compound eyes. In particular, the eye structures of an adult Xenos peckii exhibit hundreds of photoreceptors on an individual eyelet and offer engineering inspiration for ultrathin cameras or imaging applications because they have higher visual acuity than other compound eyes.
For instance, Xenos peckii’s eye-inspired cameras provide a 50 times higher spatial resolution than those based on arthropod eyes. In addition, the effective image resolution of the Xenos peckii’s eye can be further improved using the image overlaps between neighboring eyelets. This unique structure offers higher visual resolution than other insect eyes.
The team achieved high-contrast and super-resolution imaging through a novel arrayed design of micro-optical elements comprising multilayered aperture arrays and inverted micro-lens arrays directly stacked over an image sensor. This optical component was integrated with a complementary metal oxide semiconductor image sensor.
This is first demonstration of super-resolution imaging which acquires a single integrated image with high contrast and high resolving power reconstructed from high-contrast array images. It is expected that this ultrathin arrayed camera can be applied for further developing mobile devices, advanced surveillance vehicles, and endoscopes.
Professor Jeong said, “This research has led to technological advances in imaging technology. We will continue to strive to make significant impacts on multidisciplinary research projects in the fields of microtechnology and nanotechnology, seeking inspiration from natural photonic structures.”
This work was featured in Light Science & Applications last month and was supported by the National Research Foundation (NRF) of and the Ministry of Health and Welfare (MOHW) of Korea.
Image credit: Professor Ki-Hun Jeong, KAIST
Image usage restrictions: News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only.
Publication:
Kisoo Kim, Kyung-Won Jang, Jae-Kwan Ryu, and Ki-Hun Jeong. (2020) “Biologically inspired ultrathin arrayed camera for high-contrast and high-resolution imaging”. Light Science & Applications. Volume 9. Article 28. Available online at https://doi.org/10.1038/s41377-020-0261-8
Profile:
Ki-Hun Jeong
Professor
kjeong@kaist.ac.kr
http://biophotonics.kaist.ac.kr/
Department of Bio and Brain Engineering
KAIST
Profile:
Kisoo Kim
Ph.D. Candidate
kisoo.kim1@kaist.ac.kr
http://biophotonics.kaist.ac.kr/
Department of Bio and Brain Engineering
KAIST
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2020.03.23 View 17836 -
Wearable Strain Sensor Using Light Transmittance Helps Measure Physical Signals Better
KAIST researchers have developed a novel wearable strain sensor based on the modulation of optical transmittance of a carbon nanotube (CNT)-embedded elastomer. The sensor is capable of sensitive, stable, and continuous measurement of physical signals. This technology, featured in the March 4th issue of ACS Applied Materials & Interfaces as a front cover article, shows great potential for the detection of subtle human motions and the real-time monitoring of body postures for healthcare applications.
A wearable strain sensor must have high sensitivity, flexibility, and stretchability, as well as low cost. Those used especially for health monitoring should also be tied to long-term solid performance, and be environmentally stable. Various stretchable strain sensors based on piezo-resistive and capacitive principles have been developed to meet all these requirements.
Conventional piezo-resistive strain sensors using functional nanomaterials, including CNTs as the most common example, have shown high sensitivity and great sensing performance. However, they suffer from poor long-term stability and linearity, as well as considerable signal hysteresis. As an alternative, piezo-capacitive strain sensors with better stability, lower hysteresis, and higher stretchability have been suggested. But due to the fact that piezo-capacitive strain sensors exhibit limited sensitivity and strong electromagnetic interference caused by the conductive objects in the surrounding environment, these conventional stretchable strain sensors are still facing limitations that are yet to be resolved.
A KAIST research team led by Professor Inkyu Park from the Department of Mechanical Engineering suggested that an optical-type stretchable strain sensor can be a good alternative to resolve the limitations of conventional piezo-resistive and piezo-capacitive strain sensors, because they have high stability and are less affected by environmental disturbances. The team then introduced an optical wearable strain sensor based on the light transmittance changes of a CNT-embedded elastomer, which further addresses the low sensitivity problem of conventional optical stretchable strain sensors.
In order to achieve a large dynamic range for the sensor, Professor Park and his researchers chose Ecoflex as an elastomeric substrate with good mechanical durability, flexibility, and attachability on human skin, and the new optical wearable strain sensor developed by the research group actually shows a wide dynamic range of 0 to 400%.
In addition, the researchers propagated the microcracks under tensile strain within the film of multi-walled CNTs embedded in the Ecoflex substrate, changing the optical transmittance of the film. By doing so, it was possible for them to develop a wearable strain sensor having a sensitivity 10 times higher than conventional optical stretchable strain sensors.
The proposed sensor has also passed the durability test with excellent results. The sensor’s response after 13,000 sets of cyclic loading was stable without any noticeable drift. This suggests that the sensor response can be used without degradation, even if the sensor is repeatedly used for a long time and in various environmental conditions.
Using the developed sensor, the research team could measure the finger bending motion and used it for robot control. They also developed a three-axes sensor array for body posture monitoring. The sensor was able to monitor human motions with small strains such as a pulse near the carotid artery and muscle movement around the mouth during pronunciation.
Professor Park said, “In this study, our group developed a new wearable strain sensor platform that overcomes many limitations of previously developed resistive, capacitive, and optical-type stretchable strain sensors. Our sensor could be widely used in a variety of fields including soft robotics, wearable electronics, electronic skin, healthcare, and even entertainment.”
This work was supported by the National Research Foundation (NRF) of Korea.
Publication:
Jimin Gu, Donguk Kwon, Junseong Ahn, and Inkyu Park. (2020) “Wearable Strain sensors Using Light Transmittance Change of Carbon Nanotube-Embedded Elastomers with Microcracks” ACS Applied Materials & Interfaces. Volume 12. Issue 9. Available online at https://doi.org/10.1021/acsami.9b18069
Profile:
Inkyu Park
Professor
inkyu@kaist.ac.kr
http://mintlab1.kaist.ac.kr
Micro/Nano Transducers Laboratory (MINT Lab)
Department of Mechanical Engineering (ME)Korea Advanced Institute of Science and Technology (KAIST)
Profile:
Jimin Gu
Ph.D. Candidate
mint9411@kaist.ac.kr
http://mintlab1.kaist.ac.kr
MINT Lab
KAIST ME
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2020.03.20 View 18477 -
COVID-19 Update: All Undergrad Housing Closed
KAIST stepped up preventive measures against the outbreak of COVID-19 by closing all housing complexes for undergraduate students.
Provost Kwang-Hyung Lee, in an email to KAIST community members on March 12, advised all undergraduate students who had already moved in to the dormitories to move out by March 23. The university opened the spring semester on March 16, two weeks later than originally scheduled, due to the outbreak. All in-person classes have been shifted to online classes and this will continue until further notice.
“The dormitory would likely become the source of a COVID-19 cluster on the campus. Given the gravity of the current situation, we can’t help but make this unprecedented measure. It is fully for the best interests for our students’ health and safety. It saddens me to say that students are required to go back to their homes,” said Provost Lee. Dormitory fees will be refunded, and transportation and storage services will be provided for students who return back home. It has not yet been decided when they can return to the campus.
There are four exceptional cases for this special measure: 1. when a student does not have legal residency in Korea, 2. if a student’s legal residence is located in a severely affected region such as Daegu, Chongdo, and Kyongsan, 3. if students in their final semester before the graduation need to take a research class that is not available online, 4. if students have a very special reason that does not allow them to stay at home. Such students are required to meet the Associate Vice President of Student Life for approval of the exceptional stay.
Meanwhile, the first day of the online semester on March 16 saw an overwhelming amount of traffic on the remote educational platform, the KAIST learning management system (KLMS), and the real-time platform, Zoom. The two systems were both overloaded. The Dean of the KAIST Academy sent an email to the community, explaining the technical glitch causing the overload. He said his office had fixed the problem, allowing resumed access to the system from inside and outside the campus. Considered the nature of classes that are difficult or impossible to provide online, the university decided to cancel the some of physical training classes such as golf, dance sports, badminton, swimming, and tennis this semester.
Social distancing is another issue the university is enhancing throughout the campus. The university announced new lunch break shifts to disperse the dining hall crowds; the first shift is from 11:30 to 12:30 and the second shift is from 12:30 to 13:30, effective from March 17. The COVID-19 response bulletin also instructed KAIST community members to sit in a row, not face to face, when eating together with colleagues, and asked them to refrain from talking while eating. In addition, a total of 29 virus and fine duster filtering machines have been installed across the campus dining facilities.
The bulletin posted on March 13 restressed the importance of wearing a face mask in compact areas such as elevators and refrain the non-essential business or personal travel. Parents who need to take care of their children due to the closure of schools and day care centers are advised to work from home.
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2020.03.16 View 8248 -
Scientists Observe the Elusive Kondo Screening Cloud
Scientists ended a 50-year quest by directly observing a quantum phenomenon
An international research group of Professor Heung-Sun Sim has ended a 50-year quest by directly observing a quantum phenomenon known as a Kondo screening cloud. This research, published in Nature on March 11, opens a novel way to engineer spin screening and entanglement. According to the research, the cloud can mediate interactions between distant spins confined in quantum dots, which is a necessary protocol for semiconductor spin-based quantum information processing. This spin-spin interaction mediated by the Kondo cloud is unique since both its strength and sign (two spins favor either parallel or anti-parallel configuration) are electrically tunable, while conventional schemes cannot reverse the sign.
This phenomenon, which is important for many physical phenomena such as dilute magnetic impurities and spin glasses, is essentially a cloud that masks magnetic impurities in a material. It was known to exist but its spatial extension had never been observed, creating controversy over whether such an extension actually existed.
Magnetism arises from a property of electrons known as spin, meaning that they have angular momentum aligned in one of either two directions, conventionally known as up and down. However, due to a phenomenon known as the Kondo effect, the spins of conduction electrons—the electrons that flow freely in a material—become entangled with a localized magnetic impurity, and effectively screen it. The strength of this spin coupling, calibrated as a temperature, is known as the Kondo temperature.
The size of the cloud is another important parameter for a material containing multiple magnetic impurities because the spins in the cloud couple with one another and mediate the coupling between magnetic impurities when the clouds overlap. This happens in various materials such as Kondo lattices, spin glasses, and high temperature superconductors.
Although the Kondo effect for a single magnetic impurity is now a text-book subject in many-body physics, detection of its key object, the Kondo cloud and its length, has remained elusive despite many attempts during the past five decades. Experiments using nuclear magnetic resonance or scanning tunneling microscopy, two common methods for understanding the structure of matter, have either shown no signature of the cloud, or demonstrated a signature only at a very short distance, less than 1 nanometer, so much shorter than the predicted cloud size, which was in the micron range.
In the present study, the authors observed a Kondo screening cloud formed by an impurity defined as a localized electron spin in a quantum dot—a type of “artificial atom”—coupled to quasi-one-dimensional conduction electrons, and then used an interferometer to measure changes in the Kondo temperature, allowing them to investigate the presence of a cloud at the interferometer end.
Essentially, they slightly perturbed the conduction electrons at a location away from the quantum dot using an electrostatic gate. The wave of conducting electrons scattered by this perturbation returned back to the quantum dot and interfered with itself. This is similar to how a wave on a water surface being scattered by a wall forms a stripe pattern. The Kondo cloud is a quantum mechanical object which acts to preserve the wave nature of electrons inside the cloud.
Even though there is no direct electrostatic influence of the perturbation on the quantum dot, this interference modifies the Kondo signature measured by electron conductance through the quantum dot if the perturbation is present inside the cloud. In the study, the researchers found that the length as well as the shape of the cloud is universally scaled by the inverse of the Kondo temperature, and that the cloud’s size and shape were in good agreement with theoretical calculations.
Professor Sim at the Department of Physics proposed the method for detecting the Kondo cloud in the co-research with the RIKEN Center for Emergent Matter Science, the City University of Hong Kong, the University of Tokyo, and Ruhr University Bochum in Germany.
Professor Sim said, “The observed spin cloud is a micrometer-size object that has quantum mechanical wave nature and entanglement. This is why the spin cloud has not been observed despite a long search. It is remarkable in a fundamental and technical point of view that such a large quantum object can now be created, controlled, and detected.
Dr. Michihisa Yamamoto of the RIKEN Center for Emergent Matter Science also said, “It is very satisfying to have been able to obtain real space image of the Kondo cloud, as it is a real breakthrough for understanding various systems containing multiple magnetic impurities. The size of the Kondo cloud in semiconductors was found to be much larger than the typical size of semiconductor devices.”
Publication:
Borzenets et al. (2020) Observation of the Kondo screening cloud. Nature, 579. pp.210-213. Available online at https://doi.org/10.1038/s41586-020-2058-6
Profile:
Heung-Sun Sim, PhD
Professor
hssim@kaist.ac.kr
https://qet.kaist.ac.kr/
Quantum Electron Correlation & Transport Theory Group (QECT Lab)
https://qc.kaist.ac.kr/index.php/group1/
Center for Quantum Coherence In COndensed Matter
Department of Physics
https://www.kaist.ac.kr
Korea Advanced Institute of Science and Technology (KAIST)
Daejeon, Republic of Korea
2020.03.13 View 15558