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KAIST student wins Aerospace Student Papers Grand Prize
Dong-Il Yoo, a doctoral candidate under Professor Hyun-Chul Shim, at the Department of Aerospace Engineering, KAIST, has been awarded the Second Prize Award at the 11th Korea Aerospace Industries (KAI) Paper Contest. The award ceremony was held on October 30th at the media conference room at the KINTEX ADEX 2013 Exhibition in Seoul.
Yoo"s paper, titled "A Study on Virtual Pursuit Point-based Autonomous Air Combat Guidance Law for UCAV," is highly regarded for originality and creativity. The Field Robotics Center at the KAIST Institute, where Yoo conducted his research, also received the first prize at the 7th KAI Paper Contest.
The KAI Paper Contest was first organized in 2003 to promote academic interest and advance research and development in aerospace engineering among university students.
The KAI Paper Contest is one of the most prestigious contests in Korea. It is sponsored by the Ministry of Trade, Industry and Energy, the Ministry of Land, Infrastructure and Transport, the Korean Society for Aeronautical and Space Sciences, the Korea Aerospace Industries Association, and the Korea Civil Aviation Development Association.
Dong-Il Yoo (left) and Professor Hyun-Chul Shim (right)
2013.11.11 View 12860 -
Kinetic Lighting, Dlight, Dominates World Renowned Design Awards
Professor Sang-Min Bae
“D’light,” a lamp that transforms its lampshade shape, developed by a team led by KAIST Department of Industrial Design’s Professor Sang-Min Bae, won Japan’s Good Design Awards on October the 2nd, soon after winning the internationally renowned 2013 International Design Excellence Awards (IDEA) in August.
IDEA, sponsored by the Industrial Design Society of America (IDSA) and BusinessWeek, awards the best work from over 6,000 exhibits from 50 countries. Japan’s Good Design Awards, founded by the Japan Institute of Design Promotion (JDP) in 1957, is the most prestigious and one of the World’s four major design awards.
“D’light” combines “donative” and “light.” Its meaning originates from the meaning of “delight” which means “giving great joy.” The shape and the brightness of the lamp can be transformed by turning the end of the heart-shaped lampshade. The team states that the lamp carries a figurative meaning of generous hearts lighting the neglected of the world by designing the lamp to be the brightest when it takes the shape of a heart. D’light developed as the 5th product of “the Nanum” project that started in 2006. Professor Bae first participated in the project in developing the 2nd product, “Cross Cube” in 2007. The he designed and launched the environmentally friendly humidifier “Lovepot” in 2008 and interactive tumbler “Hearty” in 2009.
The “Nanum” project aims to develop innovative products for charity to create a humane social circulatory system. The project, led by the international relief and development organisation, World Vision and KAIST’s ID+IM laboratory run by Professor Bae, donates all profits to educate the children of low-income families. The project raised a total of 1.7 billion Korean won from 2007 this year to provide scholarships to 240 children in need.
Professor Bae’s team has undertaken seed and “Nanum” projects with the theme of philanthropy design helping people in need by creating innovative designs. The project has produced four excellent and authentic products which received 44 world renowned design awards.
Professor Bae said, “’The Nanum’ project consists of planning, designing, producing and selling for charity and donates all profit to children in need through education and scholarship.” He continued, “The consumers can purchase products that are aesthetically pleasing and convenient as well as gaining an opportunity to donate to children in need.”
Figure1 Kinetic lighting D’light
Figure 2. Characteristics of “Nanum” D’light
The shape of the lampshade can be transformed. The lamp sheds the brightest light when it takes the shape of a heart, hence showing the figurative meaning of brightening the neglected parts of the world with generous hearts.
Figure 3. Detailed Images of D’light
2013.11.11 View 10220 -
KAIST graduate appointed as professor at Southeast University in China
Dr. Yoon-Kyu Ahn has been appointed as a professor in the civil engineering department at Southeast University in Nanjing, China.
Dr. Ahn earned his Master’s and Ph.D. in civil & environmental engineering at KAIST, under the guidance of Professor Hoon Sohn, following his undergraduate studies at Korea University.His appointment is considered quite exceptional since most of top Chinese universities are likely hiring professors from the US and EU as a general trend.Ranked third in the field of civil engineering in China, Southeast University has been among the top ten universities in the nation. The university has 27,000 students with 1,300 faculty members in 34 schools.
2013.11.06 View 7247 -
Professor Jae-Hyung Lee appointed as AIChE fellow
Professor Jae-Hyung Lee from the Department of Chemical and Bimolecular Engineering at KAIST was appointed as a fellow in the American Institute of Chemical Engineers (AIChE).
Established in 1908, AIChE is the largest association of chemical engineers worldwide, which now boasts more than 40,000 members from 90 countries.
Following Distinguished Professor Sang Yup Lee from the same department at KAIST, Professor Jae-Hyung Lee is the second Korean appointed as a fellow by the organization.
He has been acknowledged for his innovative research on the improvement of model predictive control of industrial processes.
Professor Lee is the director of the Saudi Armaco-KAIST CO2 Management Center at KAIST, a fellow of the Institute of Electrical and Electronics Engineers (IEEE) and the International Federation of Automatic Control (IFAC), and a member of the Korean Academy of Science and Technology.
He received the Young Investigator Award from the National Science Foundation (NSF) in 1994 and the Computing in Chemical Engineering Award from AIChE in 2013.
2013.11.05 View 9924 -
Metabolically engineered E. coli producing phenol
Many chemicals we use in everyday life are derived from fossil resources. Due to the increasing concerns on the use of fossil resources, there has been much interest in producing chemicals from renewable resources through biotechnology.
Phenol is an important commodity chemical, and is a starting material for the production of numerous industrial chemicals and polymers, including bisphenol A and phenolic resins, and others. At present, the production of phenol entirely depends on the chemical synthesis from benzene, and its annual production exceeds 8 million tons worldwide. Microbial production of phenol seems to be a non-viable process considering the high toxicity of phenol to the cell.
In the paper published online in Biotechnology Journal, a Korean research team led by Distinguished Professor Sang Yup Lee at the Department of Chemical and Biomolecular Engineering from the Korea Advanced Institute of Science and Technology (KAIST) reported the successful development of an engineered Escherichia coli (E. coli) strain which can produce phenol from glucose. E. coli has been a workhorse for biological production of various value-added compounds such as succinic acid and 1,4-butanediol in industrial scale. However, due to its low tolerance to phenol, E. coli was not considered a viable host strain for the biological production of phenol.
Professor Lee"s team, a leading research group in metabolic engineering, noted the genetic and physiological differences of various E. coli strains and investigated 18 different E. coli strains with respect to phenol tolerance and engineered all of the 18 strains simultaneously. If the traditional genetic engineering methods were used, this work would have taken years to do. To overcome this challenge, the research team used synthetic small RNA (sRNA) technology they recently developed (Nature Biotechnology, vol 31, pp 170-174, 2013). The sRNA technology allowed the team to screen 18 E. coli strains with respect to the phenol tolerance, and the activities of the metabolic pathway and enzyme involved in the production of phenol. The research team also metabolically engineered the E. coli strains to increase carbon flux toward phenol and finally generated an engineered E. coli strain which can produce phenol from glucose.
Furthermore, the team developed a biphasic extractive fermentation process to minimize the toxicity of phenol to E. coli cells. Glycerol tributyrate was found to have low toxicity to E. coli and allowed efficient extraction of phenol from the culture broth. Through the biphasic fed-batch fermentation using glycerol tributyrate as an in situ extractant, the final engineered E. coli strain produced phenol to the highest titer and productivity reported (3.8 g/L and 0.18 g/L/h, respectively). The strategy used for the strain development and the fermentation process will serve as a framework for metabolic engineering of microorganisms for the production of toxic chemicals from renewable resources.
This work 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.
Process of Phenol Production
2013.11.05 View 10482 -
KAIST announced a novel technology to produce gasoline by a metabolically engineered microorganism
A major scientific breakthrough in the development of renewable energy sources and other important chemicals; The research team succeeded in producing 580 mg of gasoline per liter of cultured broth by converting in vivo generated fatty acids
For many decades, we have been relying on fossil resources to produce liquid fuels such as gasoline, diesel, and many industrial and consumer chemicals for daily use. However, increasing strains on natural resources as well as environmental issues including global warming have triggered a strong interest in developing sustainable ways to obtain fuels and chemicals.
Gasoline, the petroleum-derived product that is most widely used as a fuel for transportation, is a mixture of hydrocarbons, additives, and blending agents. The hydrocarbons, called alkanes, consist only of carbon and hydrogen atoms. Gasoline has a combination of straight-chain and branched-chain alkanes (hydrocarbons) consisted of 4-12 carbon atoms linked by direct carbon-carbon bonds.
Previously, through metabolic engineering of Escherichia coli (E. coli), there have been a few research results on the production of long-chain alkanes, which consist of 13-17 carbon atoms, suitable for replacing diesel. However, there has been no report on the microbial production of short-chain alkanes, a possible substitute for gasoline.
In the paper (entitled "Microbial Production of Short-chain Alkanes") published online in Nature on September 29, a Korean research team led by Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering at the Korea Advanced Institute of Science and Technology (KAIST) reported, for the first time, the development of a novel strategy for microbial gasoline production through metabolic engineering of E. coli.
The research team engineered the fatty acid metabolism to provide the fatty acid derivatives that are shorter than normal intracellular fatty acid metabolites, and introduced a novel synthetic pathway for the biosynthesis of short-chain alkanes. This allowed the development of platform E. coli strain capable of producing gasoline for the first time. Furthermore, this platform strain, if desired, can be modified to produce other products such as short-chain fatty esters and short-chain fatty alcohols.
In this paper, the Korean researchers described detailed strategies for 1) screening of enzymes associated with the production of fatty acids, 2) engineering of enzymes and fatty acid biosynthetic pathways to concentrate carbon flux towards the short-chain fatty acid production, and 3) converting short-chain fatty acids to their corresponding alkanes (gasoline) by introducing a novel synthetic pathway and optimization of culture conditions. Furthermore, the research team showed the possibility of producing fatty esters and alcohols by introducing responsible enzymes into the same platform strain.
Professor Sang Yup Lee said, "It is only the beginning of the work towards sustainable production of gasoline. The titer is rather low due to the low metabolic flux towards the formation of short-chain fatty acids and their derivatives. We are currently working on increasing the titer, yield and productivity of bio-gasoline. Nonetheless, we are pleased to report, for the first time, the production of gasoline through the metabolic engineering of E. coli, which we hope will serve as a basis for the metabolic engineering of microorganisms to produce fuels and chemicals from renewable resources."
This research was supported by the Advanced Biomass Research and Development Center of Korea (ABC-2010-0029799) through the Global Frontier Research Program of the Ministry of Science, ICT and Future Planning (MSIP) through the National Research Foundation (NRF), Republic of Korea. Systems metabolic engineering work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012-C1AAA001-2012M1A2A2026556) by MSIP through NRF.
Short-Chain Alkanes Generated from Renewable Biomass
This diagram shows the metabolic engineering of Escherichia coli for the production of short-chain alkanes (gasoline) from renewable biomass.
Nature Cover Page (September 29th, 2013)
2013.11.04 View 12390 -
KAIST Hosted the 6th International Presidential Forum on Global Research Universities
More than 120 global leaders from higher education, private and public sectors, to discuss the promotion of economic growth through knowledge creation and entrepreneurship
The Korea Advanced Institute of Science and Technology (KAIST) held the 6th International Presidential Forum on Global Research Universities (IPFGRU) on October 15th at the Westin Chosun Hotel in Seoul, Republic of Korea.
About 64 presidents and vice presidents from 57 research universities in 28 nations attended for a presentation and panel discussion on the topic of “The Role and Responsibility of Research Universities: Knowledge Creation, Technology Transfer, and Entrepreneurship.”Annually held, the forum is organized to promote excellence and innovation in higher education and provide a place for discussion among prominent research university leaders and key policy-makers in the private and public sectors from across the world.Among the notable universities attending the 2013 forum were the University of California, Irvine, the École Polytechnique Fédérale de Lausanne, Technische Universität Berlin, Technion-Israel Institute of Technology, Tokyo Institute of Technology, Rice University, the University of Waterloo, and Massachusetts Institute of Technology (MIT). Government officials as well as representatives from business and industry such as Samsung Electronics, Korea Telecom, and Elsevier also joined the event.
The forum was proceeded with three separate sessions: Enabling Knowledge Creation, Entrepreneurship & University-Based Technology Transfer, and Higher Education & Strategic Knowledge Creation: Specialization & Performance, through which speakers and panelists examined how universities have played a role in knowledge creation and technology transfer, and ultimately how they have contributed to the development of national economies.
Keynote speakers were Michael Drake, chancellor of UC Irvine, and Jörg Steinbach, president of Technische Universität Berlin. Forum participants shared their experiences and insights in starting up knowledge- and technolgy-based new businesses.
Steve Kang, president of KAIST, talked about the purpose of the 2013 IPFGRU:
“In the face of an ever-changing economic climate driven by shifts in technological advancement, demographic trends, and global integration, the role of research universities is becoming ever more significant in achieving sustainable economic growth. This forum will help participants from around the world to define the choices ahead as universities seek the most productive and beneficial models for cooperation with industry, venture startups, and government.”For the 2013 IPFGRU, Ministry of Science, ICT, and Future Planning, ROK, Saudi Aramco, Samsung Heavy Industries, S-Oil, Elsevier, Thomson Reuters, and the Korea Economic Daily were forum sponsors.
2013.11.04 View 10798 -
First Prize in the 2013 International Military Science and Technology Contest
Professor James R. Morrison and his students of the Industrial and Systems Engineering Department at KAIST were awarded the first prize in the 2013 International Military Science and Technology Contest organized by the Defense Acquisition Program Administration held in COEX from July 11 to 14.
The research group, Byungduk Song (Ph.D candidate), Jonghoe Kim (Ph.D candidate), Hyolin Park (MS candidate) and Professor James R. Morrison, received the first prize with their paper entitled “Automated and persistent UAV system for a complementary method for border patrol and target tracking.”
The Defense Acquisition Program Administration is the host of the annual contest which aims to contribute to the future of the defense industry and to expand technology exchange between private institutes and the military through the coordination of defense technology and advanced technology from industrial and educational cooperation.Professor Morrison’s team received the honor of the first-place prize out of 56 competitors from within Korea and 7 from overseas in the field of Synthetic New Technology/Academic Thesis.
2013.10.31 View 9368 -
Distinguished Professor Sang Yup Lee appointed as an advisor for Shanghai Jiao Tong University in China
In recognition of his outstanding accomplishments in the area of bioengineering, specializing in metabolic engineering, Sang Yup Lee, a distinguished professor of Chemical & Biomolecular Engineering at KAIST, was assigned as an advisory professor for the bioengineering department at Shanghai Jiao Tong University in China for five years from August 2013 to July 2018.
Together with Peking University and Tsinghua University, Shanghai Jiao Tong University is one of the top three universities in China.
The advisory professors carry out collaborated research programs in special areas and provide advice on education and research issues.
Professor Lee, a specialist in metabolic engineering, has initiated systems metabolic engineering which integrates metabolic engineering, systems biology, and synthetic biology and has applied it to various chemical production systems to develop bio fuel and many eco-friendly chemical production processes. Recently, he received the Marvin J. Johnson Award from the American Chemistry Society, the Charles Thom Award from the American Society for Industrial Microbiology, as well as the Amgen Biochemical Engineering Award. As a global leader in the area of bioengineering, Professor Lee is a member of the Korean Academy of Science & Technology, the National Academy of Engineering of Korea, the US National Academy of Engineering, and is the chairman of the Global Agenda Council on Biotechnology at the World Economic Forum.
2013.10.31 View 9150 -
Core Technology for Lithium Air Secondary Battery Developed
KAIST-Kyonggi University joint research team developed composite catalyst out of nano fiber and graphene
Five times improvement in capacity compared to lithium-ion secondary battery, driving 800 km at maximum
The core technology for lithium air secondary battery, the next generation high capacity battery, has been developed.
A research team formed by KAIST Department of Materials Science’s Professors Il-Doo Kim and Seokwoo Jeon, and Kyonggi University Department of Materials Science’s Professor Yong-Joon Park has created a lithium air secondary battery, with five times greater storage than the lithium-ion secondary battery, by developing a nano fiber-graphene composite catalyst. The research results are published in the August 8th online edition of Nano Letters.
A cathode of a lithium-ion battery consists of graphite and an anode of the battery consists of a lithium transition metal oxide. Lithium-ion batteries are widely used in mobile phones and laptops. However, lithium-ion batteries cannot support electric vehicles, providing energy for only 160 kilometers on one full charge. The lithium air secondary battery just developed by the research team uses lithium on the cathode and oxygen on the anode. It is earning a popular acknowledgement among the next generation secondary battery research community for having lightweight mass and high energy density.
However, lithium-ion batteries remain difficult to commercialize because of their short lifespan. Lithium and oxygen meet up to form lithium oxide (Li2O2) at discharge, and decompose again at charge. In a traditional lithium air battery, this cycle does not occur smoothly and results in high resistance, thereby reducing the lifespan of the battery. It is thus essential to develop high efficiency catalyst that facilitates the formation and decomposition of lithium oxides.
The research team used electric radiation to develop a nano composite catalyst by mixing cobalt oxide nano fiber and graphene. The performance of the battery has been maximized by settling nonoxidative graphene, which has high specific surface area and electrical conductivity, on catalyst active cobalt oxide nano fiber. Applying the nano composite catalyst on both poles of the lithium air battery resulted in an improved lifespan of over 80 recharge cycles with capacity greater than 100mAh/g, five times greater than a lithium ion battery. The newly discovered charge-discharge property is the highest among the reported performances of the lithium air battery so far.
The lithium air battery is cheap to make, as the main materials are metal oxide and graphene. “There are yet more issues to resolve such as stability, but we will collaborate with other organizations to open up the era of electronic vehicles,” said Professor Il-Doo Kim. “We hope to contribute to vitalizing the fields of next generation lithium air battery by leading nanocatalyst synthesis technology, one of the core materials in the fields of secondary battery,” Professor Kim spoke of his aspiration.
The graduate students participated in the research are Won-Hee Ryu, a postdoctorate at KAIST Department of Materials Science, Sungho Song, a PhD candidate at KAIST Department of Materials Science, and Taek-Han Yoon, a graduate student at Kyonggi University.
Picture I: Schematic Diagram of Lithium Air Battery Made of Nano Composite Catalysts
Picture II: Images of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts
Picture III: Images of Manufacturing Process of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts for Lithium Air Battery
2013.10.18 View 12209 -
Nanowire Made of Diverse Materials May Become Marketable
- Technology to commercialize nanowire developed after 2 years of industrial-academic joint research -
- 2 million strands of 50nm-width, 20 cm-length nanowire mass producible in 2 hours –
A South Korean joint industrial-academic research team has developed the technology to put forward the commercialization of nanowire that is only a few nanometers wide. It is expected to be applied in various fields such as semiconductors, high performance sensors, and biodevices.
In cooperation with LG Innotek and the National Nanofab center, Professor Jun-Bo Yoon, from KAIST Department of Electrical Engineering, developed the technology to mass produce nanowire at any length with various materials. The research results are published on the online edition of Nano Letters on July 30th.
Nanowire has a long linear structure with its width at 100 nanometers at maximum. It is a multifunctional material that has yet undiscovered thermal, electric, and mechanical properties. Nanowire is highly acclaimed as a cutting-edge material with unique nano-level properties that can be applied in semiconductors, energy, biodevices, and optic devices.
Previously, nanowires had an extremely low synthesis rate that required three or four days to grow few millimeters. It was therefore difficult to produce the desired products using nanowires. Moreover, nanowires needed to be evenly arranged for practical application, but the traditional technology required complex post-treatment, not to mention the arrangement was not immaculate.
The research team applied semiconductor process instead of chemical synthesis to resolve these issues. The team first formed a pattern greater that of the target frequency by using a photo-engraving process on a silicon wafer board whose diameter was 20 centimeters, then repeatedly reduced the frequency to produce 100 nm ultrafine linear grid pattern. Based on this pattern, the research team applied the sputtering process to mass-produce nanowires in perfect shapes of 50 nm width and 20 cm maximum length.
The new technology requires neither a lengthy synthesis process nor post-cleaning to attain a perfectly aligned state. Thus, academic and industrial circles consider the technology has high possibilities for commercialization.
“The significance is in resolving the issues in traditional technology, such as low productivity, long manufacturing time, restrictions in material synthesis, and nanowire alignment,” commented Professor Yoon on this research. “Nanowires have not been widely applied in the industry, but this technology will bring forward the commercialization of high performance semiconductors, optic devices, and biodevices that make use of nanowires.”
2013.10.18 View 9678 -
Therapy developed to induce Angiogenesis of Retina
- Junyeop Lee, Graduate School of Medical Sciences and Engineering
- Research results expected to be applied for treatment of diabetic retinopathy
A major clue to treatment of retinovascular disease, which causes blindness, has been found. The key to protection of the retinal nerve is the angiogenic protein that promotes healthy retinal vessel growth around the retina, which usually does not receive blood supply readily. This research offers a beginning to the possible improvement of therapy for diabetic retinopathy1 and retinopathy of prematurity2. Also important to the research is the fact that the ophthalmology specialist researcher, currently undergoing professional training, provided the results.
KAIST Graduate School of Medical Sciences and Engineering’s Junyeop Lee is the opthalmology specialist, who carried out the research under supervision by academic advisers Gyuyeong Go and Wookjun Yoo. The Ministry of Science, ICT and Future Planning as well as the National Research Foundation of Korea have funded his research. The research results have been published as a cover paper on ‘Science Translational Medicine’ on 18th August. This journal is a sister publication of Science, which is prestigious in the field of translational medicine that ties the basic science with clinical medicine. (Thesis title: Angiopoietin-1 Guides Directional Angiogenesis Through Integrin αvβ5 Signaling for Recovery of Ischemic Retinopathy)
The traditional treatment of diabetic retinopathy includes laser photocoagulation to destroy the retinal tissues or antibody therapeutics, which prevents vessel proliferation and blood leaking. The advantage of antibody therapeutics3 is that it retains the retinal nerves, however, it is not the fundamental solution but merely a temporary one, which requires repeated treatments.
The research team identified that Angiopoietin-14 protein, known as essential for growth and stabilization of vessels, also plays an important role in retinal vessel growth. The protein protects the retinal nerves, as well as provides improvement for retinal ischemia5 that is the root cause of vision loss due to retinal hemorrhages. It is expected to become a key to finding fundamental treatment method – by providing sufficient blood supply to the retina, thereby preserving the retinal nerve functions.
The results show that administration of Angiopoietin-1 to retinopathy mouse model promotes growth of healthy vessel growth, further preventing abnormal vessel growth, retinal hemorrhage and vision loss due to retinal ischemia.
Junyeop Lee said, “This research has identified that Angiopoietin-1 is an important factor in retinal vessel generation and stabilization. The paradigm will shift from traditional treatment method, which prevents vessel growth, to a new method that generates healthy vessels and strengthens vessel functions.”
1 Diabetic retinopathy: This retinovascular disease is a diabetic complication caused by insufficient blood supply. It is the major causes of blindness in adults.
2 Retinopathy of prematurity: The retinal vascular disease that occurs in premature infants with incomplete retinal vascular development. It is also the most common cause of blindness in children.
3 Antibody Therapeutics: Antibody developed to selectively inhibit abnormal blood vessel growth and leakage. Typical antibody therapeutics is Avastin and Lucentis, which hinder vascular endothelial growth factor (VEGF).
4 Angiopoietin-1: A critical growth factor that induces the production of healthy blood vessels and maintains the stability of the created vessel.
5 Retinal ischemia: State of ailment where retinal tissue blood supply is not sufficient.
Figure 1. Retinopathy mouse models show that, in comparison to the control group, the VEGF-Trap treatment and Angiopoietin-1 (Ang1) treatment groups significantly suppresses the pathological vascular proliferation. In addition, the Ang 1 group show vessel growth toward the central avascular area (region of retinal ischemia), which is not observed in VEGF-Trap treatment.
Figure 2. Reduced retinal ischemia, retinal bleeding and blood vessel normalization by Angiopoietin-1. Retinal ischemic region (arrow) and retinal bleeding significantly reduced in the Angiopoietin-1 (Ang1) treatment model in comparison to control group (left). The newly generated vessels in Ang 1 model are structurally supported by perivascular cells as normal retinal vessels do (right).
2013.10.12 View 11774