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Kang CM, Kim SH, Shin Y, Lee HS, Lee JH, Kim GT, Song JS. A randomized controlled trial of ProRoot MTA, OrthoMTA and RetroMTA for pulpotomy in primary molars. Oral Dis 2015; 21:785-91. [DOI: 10.1111/odi.12348] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 04/21/2015] [Accepted: 04/29/2015] [Indexed: 11/27/2022]
Affiliation(s)
- C-M Kang
- Department of Pediatric Dentistry; College of Dentistry; Yonsei University; Seoul Korea
| | - S-H Kim
- Department of Pediatric Dentistry; College of Dentistry; Yonsei University; Seoul Korea
| | - Y Shin
- Department of Conservative Dentistry; College of Dentistry; Yonsei University; Seoul Korea
| | - H-S Lee
- Department of Pediatric Dentistry; Dental school; Kyung Hee University; Seoul Korea
| | - J-H Lee
- Department of Pediatric Dentistry; College of Dentistry; Yonsei University; Seoul Korea
| | - GT Kim
- Department of Oral and Maxillofacial radiology; Dental school; Kyung Hee University; Seoul Korea
| | - JS Song
- Department of Pediatric Dentistry; College of Dentistry; Yonsei University; Seoul Korea
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2
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Jang KI, Chung HU, Xu S, Lee CH, Luan H, Jeong J, Cheng H, Kim GT, Han SY, Lee JW, Kim J, Cho M, Miao F, Yang Y, Jung HN, Flavin M, Liu H, Kong GW, Yu KJ, Rhee SI, Chung J, Kim B, Kwak JW, Yun MH, Kim JY, Song YM, Paik U, Zhang Y, Huang Y, Rogers JA. Soft network composite materials with deterministic and bio-inspired designs. Nat Commun 2015; 6:6566. [PMID: 25782446 PMCID: PMC4383007 DOI: 10.1038/ncomms7566] [Citation(s) in RCA: 160] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 02/06/2015] [Indexed: 12/11/2022] Open
Abstract
Hard and soft structural composites found in biology provide inspiration for the design of advanced synthetic materials. Many examples of bio-inspired hard materials can be found in the literature; far less attention has been devoted to soft systems. Here we introduce deterministic routes to low-modulus thin film materials with stress/strain responses that can be tailored precisely to match the non-linear properties of biological tissues, with application opportunities that range from soft biomedical devices to constructs for tissue engineering. The approach combines a low-modulus matrix with an open, stretchable network as a structural reinforcement that can yield classes of composites with a wide range of desired mechanical responses, including anisotropic, spatially heterogeneous, hierarchical and self-similar designs. Demonstrative application examples in thin, skin-mounted electrophysiological sensors with mechanics precisely matched to the human epidermis and in soft, hydrogel-based vehicles for triggered drug release suggest their broad potential uses in biomedical devices.
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Affiliation(s)
- Kyung-In Jang
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ha Uk Chung
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sheng Xu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Chi Hwan Lee
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Haiwen Luan
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Jaewoong Jeong
- Department of Electrical, Computer and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Huanyu Cheng
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Gwang-Tae Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sang Youn Han
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
- Samsung Display Co. Display R&D Center, Yongin-city, Gyeongki-do 446–711, Republic of Korea
| | - Jung Woo Lee
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Material Science and Engineering, Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Jeonghyun Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Material Science and Engineering, Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Moongee Cho
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Fuxing Miao
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
- Department of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211, China
| | - Yiyuan Yang
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Han Na Jung
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Matthew Flavin
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Howard Liu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gil Woo Kong
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ki Jun Yu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sang Il Rhee
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jeahoon Chung
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Byunggik Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jean Won Kwak
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Myoung Hee Yun
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
- School of Energy and Chemical Engineering, Ulsan National Institute Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Jin Young Kim
- School of Energy and Chemical Engineering, Ulsan National Institute Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
| | - Young Min Song
- Department of Electronic Engineering, Biomedical Research Institute, Pusan National University, Geumjeong-gu, Busan 609-735, Republic of Korea
| | - Ungyu Paik
- Department of Material Science and Engineering, Department of Energy Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Yihui Zhang
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
- Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Yonggang Huang
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - John A. Rogers
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
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3
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Jang KI, Han SY, Xu S, Mathewson KE, Zhang Y, Jeong JW, Kim GT, Webb RC, Lee JW, Dawidczyk TJ, Kim RH, Song YM, Yeo WH, Kim S, Cheng H, Rhee SI, Chung J, Kim B, Chung HU, Lee D, Yang Y, Cho M, Gaspar JG, Carbonari R, Fabiani M, Gratton G, Huang Y, Rogers JA. Rugged and breathable forms of stretchable electronics with adherent composite substrates for transcutaneous monitoring. Nat Commun 2014; 5:4779. [PMID: 25182939 DOI: 10.1038/ncomms5779] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 07/23/2014] [Indexed: 11/09/2022] Open
Abstract
Research in stretchable electronics involves fundamental scientific topics relevant to applications with importance in human healthcare. Despite significant progress in active components, routes to mechanically robust construction are lacking. Here, we introduce materials and composite designs for thin, breathable, soft electronics that can adhere strongly to the skin, with the ability to be applied and removed hundreds of times without damaging the devices or the skin, even in regions with substantial topography and coverage of hair. The approach combines thin, ultralow modulus, cellular silicone materials with elastic, strain-limiting fabrics, to yield a compliant but rugged platform for stretchable electronics. Theoretical and experimental studies highlight the mechanics of adhesion and elastic deformation. Demonstrations include cutaneous optical, electrical and radio frequency sensors for measuring hydration state, electrophysiological activity, pulse and cerebral oximetry. Multipoint monitoring of a subject in an advanced driving simulator provides a practical example.
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Affiliation(s)
- Kyung-In Jang
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sang Youn Han
- 1] Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Samsung Display Co. Display R&D Center, Yongin-city, Gyeongki-do 446-711, Republic of Korea
| | - Sheng Xu
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Kyle E Mathewson
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Psychology, University of Alberta, Edmonton, Alberta, Canada T6G 2R3
| | - Yihui Zhang
- 1] Department of Civil and Environmental Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [3] Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Jae-Woong Jeong
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gwang-Tae Kim
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - R Chad Webb
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jung Woo Lee
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Thomas J Dawidczyk
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Rak Hwan Kim
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Young Min Song
- Department of Electronic Engineering, Pusan National University, Geumjeong-gu, Busan 609735, Republic of Korea
| | - Woon-Hong Yeo
- Department of Mechanical and Nuclear Engineering, VCU Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia 23284, USA
| | - Stanley Kim
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Huanyu Cheng
- 1] Department of Civil and Environmental Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Sang Il Rhee
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jeahoon Chung
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Byunggik Kim
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ha Uk Chung
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Dongjun Lee
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yiyuan Yang
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Moongee Cho
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - John G Gaspar
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ronald Carbonari
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Monica Fabiani
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gabriele Gratton
- 1] Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Psychology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yonggang Huang
- 1] Department of Civil and Environmental Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - John A Rogers
- Department of Materials Science and Engineering, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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4
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Xu L, Gutbrod SR, Bonifas AP, Su Y, Sulkin MS, Lu N, Chung HJ, Jang KI, Liu Z, Ying M, Lu C, Webb RC, Kim JS, Laughner JI, Cheng H, Liu Y, Ameen A, Jeong JW, Kim GT, Huang Y, Efimov IR, Rogers JA. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium. Nat Commun 2014; 5:3329. [PMID: 24569383 DOI: 10.1038/ncomms4329] [Citation(s) in RCA: 278] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Accepted: 01/27/2014] [Indexed: 01/07/2023] Open
Abstract
Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy.
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Affiliation(s)
- Lizhi Xu
- 1] Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2]
| | - Sarah R Gutbrod
- 1] Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA [2]
| | - Andrew P Bonifas
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yewang Su
- 1] Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA [2] Center for Mechanics and Materials, Tsinghua University, Beijing 100084, China
| | - Matthew S Sulkin
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - Nanshu Lu
- Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, Texas 78712, USA
| | - Hyun-Joong Chung
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada T6G 2V4
| | - Kyung-In Jang
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Zhuangjian Liu
- Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
| | - Ming Ying
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Chi Lu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - R Chad Webb
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jong-Seon Kim
- 1] Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA [2] Department of Chemical and Biomolecular Engineering (BK21 Program), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Jacob I Laughner
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - Huanyu Cheng
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Yuhao Liu
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Abid Ameen
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jae-Woong Jeong
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Gwang-Tae Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yonggang Huang
- Department of Civil and Environmental Engineering, Department of Mechanical Engineering, Center for Engineering and Health and Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208, USA
| | - Igor R Efimov
- Department of Biomedical Engineering, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
| | - John A Rogers
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Park SJ, Park J, Lee HY, Moon SE, Park KH, Kim J, Maeng S, Udrea F, Milne WI, Kim GT. High sensitive NO2 gas sensor with low power consumption using selectively grown ZnO nanorods. J Nanosci Nanotechnol 2010; 10:3385-3388. [PMID: 20358962 DOI: 10.1166/jnn.2010.2261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The noble gas sensor using multiple ZnO nanorods was fabricated with CMOS compatible process and sol-gel growth method on selective area and gas response characteristics to NO2 gas of the sensor device were investigated. We confirmed the sensors had high sensitive response denoted by the sensitivity of several tens for NO2 gas sensing and also showed pretty low power consumption close to 20 mW even though the recovery of resistance come up to almost the initial value.
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Affiliation(s)
- S J Park
- IT Convergence Component Laboratory, Electronics and Telecommunications Research Institute, Daejeon 305-350, Korea
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6
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Kim EK, Lee HY, Moon SE, Park J, Park SJ, Kwak JH, Maeng S, Park KH, Kim J, Kim SW, Ji HJ, Kim GT. Electrical characterization of ZnO single nanowire device for chemical sensor application. J Nanosci Nanotechnol 2008; 8:4698-4701. [PMID: 19049088 DOI: 10.1166/jnn.2008.ic65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Vertically well-aligned high quality ZnO nanowires were grown on GaN epilayer on c-plane sapphire via a vapor-liquid-solid (VLS) process by introducing an Au thin film (3 nm) as a catalyst. ZnO single nanowire device was ingenuously fabricated by combining conventional optical lithography and high resolution electron beam lithography and its current-voltage characteristics were measured with doing the post process to acquire reproducible performance as a chemical gas sensor. And its temperature dependent current-voltage characteristics were measured to investigate temperature dependant electrical transport. The ZnO nanowire device showed slightly non-ohmic current-voltage characteristics which may be due to back-to-back configuration of the diodes with the insulating contact barriers and showed an relatively small activation energy of 0.2 eV. To test our device as a chemical sensor, the NO2 gas response was reported at the elevated temperature.
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Affiliation(s)
- E K Kim
- Electronics and Telecommunications Research Institute, Daejeon, 305-700, Korea
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7
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Kim GT, Park ES. Thermal reproducibility and voltage stability of carbon black/multiwalled carbon nanotube and carbon black/SnO2-Sb coated titanium dioxide filled silicone rubber heaters. J Appl Polym Sci 2008. [DOI: 10.1002/app.28200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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8
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Kim GT, Webster G, Wimpenny JWT, Kim BH, Kim HJ, Weightman AJ. Bacterial community structure, compartmentalization and activity in a microbial fuel cell. J Appl Microbiol 2007; 101:698-710. [PMID: 16907820 DOI: 10.1111/j.1365-2672.2006.02923.x] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To characterize bacterial populations and their activities within a microbial fuel cell (MFC), using cultivation-independent and cultivation approaches. METHODS AND RESULTS Electron microscopic observations showed that the fuel cell electrode had a microbial biofilm attached to its surface with loosely associated microbial clumps. Bacterial 16S rRNA gene libraries were constructed and analysed from each of four compartments within the fuel cell: the planktonic community; the membrane biofilm; bacterial clumps (BC) and the anode biofilm. Results showed that the bacterial community structure varied significantly between these compartments. It was observed that Gammaproteobacteria phylotypes were present at higher numbers within libraries from the BC and electrode biofilm compared with other parts of the fuel cell. Community structure of the MFC determined by analyses of bacterial 16S rRNA gene libraries and anaerobic cultivation showed excellent agreement with community profiles from denaturing gradient gel electrophoresis (DGGE) analysis. CONCLUSIONS Members of the family Enterobacteriaceae, such as Klebsiella sp. and Enterobacter sp. and other Gammaproteobacteria with Fe(III)-reducing and electrochemical activity had a significant potential for energy generation in this system. SIGNIFICANCE AND IMPACT OF THE STUDY This study has shown that electrochemically active bacteria can be enriched using an electrochemical fuel cell.
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Affiliation(s)
- G T Kim
- Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
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9
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Kim GT, Hyun MS, Chang IS, Kim HJ, Park HS, Kim BH, Kim SD, Wimpenny JWT, Weightman AJ. Dissimilatory Fe(III) reduction by an electrochemically active lactic acid bacterium phylogenetically related to Enterococcus gallinarum isolated from submerged soil. J Appl Microbiol 2005; 99:978-87. [PMID: 16162251 DOI: 10.1111/j.1365-2672.2004.02514.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS The isolation and identification of a glucose-oxidizing Fe(III)-reducing bacteria (FRB) with electrochemical activity from an anoxic environment, and characterization of the role of Fe(III) in its metabolism. METHODS AND RESULTS A Gram-positive (Firmicutes), nonmotile, coccoid and facultative anaerobic FRB was isolated based on its ability to reduce Fe(III). Using the Vitek Gram-positive identification card kit and 16S rRNA gene sequence analysis, the isolate was identified as Enterococcus gallinarum, designated strain MG25. On glucose this isolate produced lactate plus small amounts of acetate, formate and CO2 and its growth rates were similar in the presence and absence of Fe(O)OH. These results suggest that MG25 can couple glucose oxidation to Fe(III) reduction, but without conservation of energy to support growth. Cyclic voltammetry showed that strain MG25 was electrochemically active. CONCLUSIONS An electrochemically active and FRB, E. gallinarum MG25, was isolated from submerged soil. Fe(III) is used in the bacterial metabolism as an electron sink. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report concerning the electrochemical activity of glucose-oxidizing FRB, E. gallinarum. This organism and others like it could be used as new biocatalysts to improve the performance of a mediator-less microbial fuel cell.
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Affiliation(s)
- G T Kim
- Cardiff School of Biosciences, Cardiff University, Cardiff, UK
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10
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Kim BH, Park HS, Kim HJ, Kim GT, Chang IS, Lee J, Phung NT. Enrichment of microbial community generating electricity using a fuel-cell-type electrochemical cell. Appl Microbiol Biotechnol 2004; 63:672-81. [PMID: 12908088 DOI: 10.1007/s00253-003-1412-6] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2003] [Revised: 06/27/2003] [Accepted: 06/28/2003] [Indexed: 11/30/2022]
Abstract
A fuel cell was used to enrich a microbial consortium generating electricity, using organic wastewater as the fuel. Within 30 days of enrichment the maximum current of 0.2 mA was generated with a resistance of 1 kOhms. Current generation was coupled to a fall in chemical oxygen demand from over 1,700 mg l(-1) down to 50 mg l(-1). Denaturing gradient gel electrophoresis showed a different microbial population in the enriched electrode from that in the sludge used as the inoculum. Electron microscopic observation showed a biofilm on the electrode surface and microbial clumps. Nanobacteria-like particles were present on the biofilm surface. Metabolic inhibitors and electron acceptors inhibited the current generation. 16S ribosomal RNA gene analysis showed a diverse bacterial population in the enrichment culture. These findings demonstrate that an electricity-generating microbial consortium can be enriched using a fuel cell and that the electrochemical activity is a form of anaerobic electron transfer.
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MESH Headings
- Bacteria/classification
- Bacteria/growth & development
- Bacteria/metabolism
- Bacteria/ultrastructure
- Bioelectric Energy Sources
- Biofilms/growth & development
- Catalysis
- DNA, Bacterial/analysis
- DNA, Bacterial/chemistry
- DNA, Bacterial/isolation & purification
- DNA, Ribosomal/analysis
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/isolation & purification
- Electricity
- Electrochemistry
- Electrodes
- Electron Transport/physiology
- Electrophoresis, Polyacrylamide Gel
- Environmental Microbiology
- Industrial Waste
- Molecular Sequence Data
- Organic Chemicals/metabolism
- Oxidation-Reduction
- Phylogeny
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Sewage/microbiology
- Waste Disposal, Fluid/methods
- Water Microbiology
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Affiliation(s)
- B H Kim
- Water Environment & Remediation Research Center, Korea Institute of Science and Technology, 39-1 Hawolgok, Sungpook, 136-791, Seoul, Korea.
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11
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Park ES, Yun SJ, Kim GT, Park IJ, Choi WH, Jeong JW, Hong SY, Park HW, Jang LW, Yoon JS. Preparation of positive-temperature coefficient heaters using platinum-catalyzed silicone rubber. J Appl Polym Sci 2004. [DOI: 10.1002/app.20107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Kim CH, Choi H, Chun YS, Kim GT, Park JW, Kim MS. Hyperbaric oxygenation pretreatment induces catalase and reduces infarct size in ischemic rat myocardium. Pflugers Arch 2001; 442:519-25. [PMID: 11510883 DOI: 10.1007/s004240100571] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ischemia-reperfusion injury is a major complication occurring in heart stroke, cardiopulmonary bypass surgeries, and heart transplantation. Reactive oxygen species generated during the reperfusion phase overwhelm the scavenging capacities of antioxidant enzymes, and result in oxidative damage to the myocardium. We examined whether hyperbaric oxygenation (HBO) pretreatment induces antioxidant enzymes and protects the heart from subsequent ischemia-reperfusion injury. Rats were intermittently exposed to 100% O2 at 3 ATA (where ATA is absolute atmosphere) for 1 h daily and then sacrificed after 24 h of recovery in room air. Isolated hearts were subjected to 40 min of ischemia and 90 min of reperfusion. HBO pretreatment was found to condition the heart and enhance enzymatic activity and gene expression of catalase, thereby significantly reducing infarct size after reperfusion. A catalase inhibitor, 3-amino-1,2,4-triazole, completely abolished the infarct-limiting effect of HBO pretreatment, which suggests that HBO-induced tolerance against ischemia-reperfusion injury is due to catalase induction. Our results imply that HBO preconditioning may be developed as a new preventive measure for reperfusion injury in the heart.
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Affiliation(s)
- C H Kim
- Department of Pharmacology and BK21 Human Life Sciences, Seoul National University College of Medicine and Heart Research Institute SNUMRC, South Korea.
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13
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Chun YS, Park JW, Kim GT, Shima H, Nagao M, Kim MS, Chung MH. A sds22 homolog that is associated with the testis-specific serine/threonine protein phosphatase 1gamma2 in rat testis. Biochem Biophys Res Commun 2000; 273:972-6. [PMID: 10891357 DOI: 10.1006/bbrc.2000.3045] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two cDNAs sequences (1320 bp and 1180 bp) of the 55-kDa subunit associated with a testis-specific serine/threonine protein phosphatase 1gamma2 (PP1gamma2) were cloned. They were the same up to 1180 bp, suggesting that they may be generated by alternative splicing. Sequence studies showed that the 1320 bp-cDNA is a homolog of the human sds22alpha(1) (thus, named rat sds22alpha(1)). The 1180 bp-cDNA is a new splice-variant since its sequence at the 3' end has not been identified in human sds22 genes (named rat sds22alpha(3)). The 1320 bp-cDNA is ubiquitously expressed in various tissues including the immature testis. However, the expression of 1180 bp-cDNA was only observed in the testis after puberty. This expression pattern matches very well with that of PP1gamma2, suggesting that 1180 bp-cDNA may encode the 55-kDa subunit to associate with PP1gamma2 in rat testis and is involved in spermatogenesis by controlling PP1gamma2 activity.
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Affiliation(s)
- Y S Chun
- Department of Pharmacology, Heart Research Institute Medical Research Center, Seoul National University, College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Korea
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14
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Chun YS, Choi E, Kim GT, Choi H, Kim CH, Lee MJ, Kim MS, Park JW. Cadmium blocks hypoxia-inducible factor (HIF)-1-mediated response to hypoxia by stimulating the proteasome-dependent degradation of HIF-1alpha. Eur J Biochem 2000; 267:4198-204. [PMID: 10866824 DOI: 10.1046/j.1432-1327.2000.01453.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cadmium is a substantial industrial and environmental pollutant which seriously impairs erythropoiesis. Cd has been demonstrated to aggravate anemia by suppressing erythropoietin gene expression in anemic patients. As hypoxic induction of erythropoietin mRNA depends on a transcription factor, hypoxia-inducible factor 1 (HIF-1), we hypothesized that Cd suppresses the hypoxic activation of HIF-1. In hypoxic Hep3B cells, all mRNAs of various genes, which are known to be upregulated by HIF-1 activation under hypoxia, were suppressed by Cd in a dose-dependent manner. Cd inhibited the hypoxia-induced activity of luciferase in 293 cells which was transfected with a reporter plasmid carrying a hypoxia response element. By electrophoretic mobility gel shift assay, Cd inhibited the DNA-binding activity of HIF-1 in hypoxic Hep3B cells. Cd reduced the amount of HIF-1alpha protein in hypoxia, whereas it didn't affect HIF-1 alpha mRNA levels. Moreover, Cd inhibited HIF-1alpha accumulation induced by cobalt and desferrioxamine. Antioxidants and a proteasome inhibitor prevented the HIF-1alpha degradation caused by Cd. The possibility that oxidative stress mediates this action of Cd was examined. Cd didn't affect protein oxidation and reduced glutathione levels in hypoxic cells. These results indicate that Cd triggers a redox/proteasome-dependent degradation of HIF-1alpha protein, reducing HIF-1 activity and in turn suppressing the hypoxic induction of hypoxia-inducible genes.
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Affiliation(s)
- Y S Chun
- Department of Pharmacology and Heart Research Institute, Seoul National University College of Medicine, Korea
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15
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Ito T, Kim GT, Shinozaki K. Disruption of an Arabidopsis cytoplasmic ribosomal protein S13-homologous gene by transposon-mediated mutagenesis causes aberrant growth and development. Plant J 2000; 22:257-64. [PMID: 10849343 DOI: 10.1046/j.1365-313x.2000.00728.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We identified a Dissociation (Ds) transposon-inserted Arabidopsis mutant of a gene (AtRPS13A) homologous to cytoplasmic ribosomal protein (RP) S13. We named our mutant pointed first leaf (pfl) 2 because of its similar phenotype to the pfl1 mutant of the RPS18 gene. This mutant caused multiple phenotypic changes, including aberrant leaf and trichome morphology, retarded root growth, and late flowering. Microscopic analysis showed that the first leaf blade of pfl2 contained a significantly reduced number of palisade cells, which suggests that the mutant phenotype was caused by reduced cell division. However, no phenotypic changes were observed during reproductive growth. In Arabidopsis, the RPS13 protein was encoded by a small expressed gene family including AtRPS13A. A pfl1 pfl2 double mutant showed no additive effect. These results suggest that RPS13 functions in quantitative and pleiotropic ways during growth and development, and that mutations at different kinds of RP gene loci are accumulatable without serious growth defects because they belong to small gene families.
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Affiliation(s)
- T Ito
- Laboratory of Plant Molecular Biology, Tsukuba Life Science Center, The Institute of Physical and Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
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16
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Abstract
Heteroblasty in Arabidopsis thaliana was analyzed in a variety of plants with mutations in leaf morphology using a tissue-specific beta-glucuronidase gene marker. Some mutants exhibited their mutant phenotypes specifically in foliage leaves. The phenotypes associated with the foliage-leaf-specific mutations were also found to be induced ectopically in cotyledons in the presence of the lec1 mutation. Moreover, the features of an emfl lec1 double mutant showed that cotyledons can be partially converted into carpelloids. When heteroblastic traits were examined in foliage leaves in the presence of certain mutations or natural deviations by histochemical analysis of the expression of the tissue-specific marker gene, it was found that ectopic expression of the developmental program for the first foliage leaves in lec1 cotyledons seemed to affect the heteroblastic features of the first set of foliage leaves, while foliage leaves beyond the third position appeared normal. Similarly, in wild-type plants, discrepancies in heteroblastic features, relative to standard features, of foliage leaves at early positions seemed to be eliminated in foliage leaves at later positions. These results suggest that heteroblasty in foliage leaves might be affected in part by the heteroblastic stage of the preceding foliage leaves but is finally controlled autonomously at each leaf position.
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Affiliation(s)
- H Tsukaya
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan.
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17
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Chun YS, Choi E, Kim GT, Lee MJ, Lee MJ, Lee SE, Kim MS, Park JW. Zinc induces the accumulation of hypoxia-inducible factor (HIF)-1alpha, but inhibits the nuclear translocation of HIF-1beta, causing HIF-1 inactivation. Biochem Biophys Res Commun 2000; 268:652-6. [PMID: 10679259 DOI: 10.1006/bbrc.2000.2180] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The replacement of heme iron by cobalt or nickel in a putative oxygen sensor is supposed to reduce oxygen binding to the heme protein, resulting in HIF-1 activation and erythropoietin (EPO) induction. According to this hypothesis, zinc might be another example of a transition metal which is capable of stimulating EPO production. By substituting for heme iron, zinc protoporphyrin IX is produced, which has a known low oxygen affinity. However, it has been reported that zinc fails to induce EPO in normoxia, and that it suppresses EPO production in hypoxic cells. This unexpected effect of zinc on EPO production is not understood. In this study, we found that zinc induced the accumulation and nuclear translocation of hypoxia-inducible factor (HIF)-1alpha but inhibited the nuclear translocation of HIF-1beta, which inactivated HIF-1 and suppressed EPO mRNA induction in hypoxic cells.
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Affiliation(s)
- Y S Chun
- Department of Pharmacology and Heart Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, 110-799, Korea
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18
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Kim GT, Tsukaya H, Saito Y, Uchimiya H. Changes in the shapes of leaves and flowers upon overexpression of cytochrome P450 in Arabidopsis. Proc Natl Acad Sci U S A 1999; 96:9433-7. [PMID: 10430960 PMCID: PMC17800 DOI: 10.1073/pnas.96.16.9433] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In Arabidopsis, the two-dimensional expansion of leaves is regulated via the polarized elongation of cells. The ROTUNDIFOLIA3 (ROT3) protein, a member of the family of cytochromes P450, is involved in this process and regulates leaf length. Transgenic plants that overexpressed a wild-type ROT3 gene had longer leaves than parent plants, without any changes in leaf width. The shapes of floral organs were also altered, but elongation of the stem, roots, and hypocotyls was unaffected. To our knowledge, no similar specific regulation of leaf length has been reported previously. Transgenic plants overexpressing the rot3-2 gene had enlarged leaf blades but leaf petioles of normal length. Morphological alterations in such transgenic plants were associated with changes in shape of leaf cells. The ROT3 gene seems to play an important role in the polar elongation of leafy organs and should be a useful tool for the biodesign of plant organs.
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Affiliation(s)
- G T Kim
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-0032, Japan
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19
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Kim GT, Tsukaya H, Uchimiya H. The CURLY LEAF gene controls both division and elongation of cells during the expansion of the leaf blade in Arabidopsis thaliana. Planta 1998; 206:175-83. [PMID: 9736998 DOI: 10.1007/s004250050389] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The CURLY LEAF (CLF) gene in Arabidopsis thaliana (L). Heynh. is required for stable repression of a floral homeotic gene, AGAMOUS in leaves and stems To clarify the function of CLF in organ development, we characterized clf mutants using an anatomical and genetic approach. The clf mutants had normal roots, hypocotyls, and cotyledons, but the foliage leaves and the stems had reduced dimensions. A decrease both in the extent of cell elongation and in the number of cells was evident in the clf mutant leaves, suggesting that the CLF gene might be involved in the division and elongation of cells during leaf morphogenesis. An analysis of the development of clf mutant leaves revealed that the period during which tell division or cell elongation occurred was of normal duration, while the rates of both cell production and cell elongation were lower than in the wild type. Two phases in the elongation of cells were also recognized from this analysis. From analysis of an angustifolia clf double mutant, we found that the two phases of elongation of leaf cells were regulated independently by each gene. Thus, the CLF gene appears to affect cell division at an earlier stage and cell elongation throughout the development of leaf primordia.
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Affiliation(s)
- G T Kim
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Japan
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20
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Kim GT, Tsukaya H, Uchimiya H. The ROTUNDIFOLIA3 gene of Arabidopsis thaliana encodes a new member of the cytochrome P-450 family that is required for the regulated polar elongation of leaf cells. Genes Dev 1998; 12:2381-91. [PMID: 9694802 PMCID: PMC317051 DOI: 10.1101/gad.12.15.2381] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The polarized processes of cell elongation play a crucial role in morphogenesis of higher plants. We reported previously that the rotundifolia3 (rot3) mutant of Arabidopsis has a defect in the polar elongation of leaf cells. In the present study, we isolated two additional alleles with mutations in the ROT3 gene. The ROT3 gene was cloned by a T-DNA-tagging method and isolation of the gene was confirmed by a molecular analysis of three rot3 mutant alleles obtained from different mutagenesis. The ROT3 gene encodes a cytochrome P-450 (CYP90C1) with domains homologous to regions of steroid hydroxylases of animals and plants. Expression of the ROT3 gene was detected in all major plant organs. Especially, higher expression was detected in the tissues that had high activity of cell division. We confirmed that the ROT3 gene controls polar elongation specifically in leaf cells by an analysis of three rot3 mutants obtained from different mutagenesis experiments. Our results imply that the ROT3 protein is a member of a new class of cytochrome P-450 encoding putative steroid hydroxylases, which is required for the regulated polar elongation of cells in leaves of Arabidopsis.
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Affiliation(s)
- G T Kim
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
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Abstract
The vmc gene encoding a metalloprotease of Vibrio mimicus (ATCC 33653) was cloned in Escherichia coli and sequenced. The vmc gene contained 1884 nt sequence which codes a polypeptide of 628 amino acids with a predicted molecular mass of 71,275 Da. The deduced amino acid sequence had the similarity of 68.5% with V. parahaemolyticus metalloprotease. The consensus sequence of a zinc binding motif (HEXXH) was identified to be HEYTH. The zymography analysis showed a gelatinolytic protein band around molecular mass of 61 kDa, and this result suggested that the cloned metalloprotease may undergo processing during secretion.
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Affiliation(s)
- J H Lee
- Department of Biotechnology and Bioengineering, Pukyong National University, Pusan, South Korea
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Ha JC, Kim GT, Kim SK, Oh TK, Yu JH, Kong IS. beta-Agarase from Pseudomonas sp. W7: purification of the recombinant enzyme from Escherichia coli and the effects of salt on its activity. Biotechnol Appl Biochem 1997; 26:1-6. [PMID: 9261996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The recombinant plasmid (pJAI), harbouring the agarase gene (pjaA) of Pseudomonas sp. W7, was introduced and expressed in Escherichia coli JM83. The agarase was purified using a combination of acetone precipitation and anion-exchange, gel-filtration and affinity chromatographies, with overall yield of 10% from the culture supernatant of E. coli JM83 (pJAI). The purified agarase migrated as a single band (molecular mass 59 kDa) on SDS/PAGE and was found to be beta-agarase, which could hydrolyse the beta-1,4 linkage of agarose to yield neoagarotetraose as the main product. Optimal enzyme activity was at pH 7.8 and the temperature optimum spanned the broad range 20-40 degrees C. The recombinant agarase was halophilic, maximum activity being exhibited at 0.9 M NaCl. This halophilic property could improve the production of neoagaro-oligosaccharides available in a marine environment.
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Affiliation(s)
- J C Ha
- Department of Biotechnology and Bioengineering, Pukyong National University, Pusan, South Korea
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Abstract
The structural gene (vmhA) of hemolysin from Vibrio mimicus (ATCC33653) was cloned and sequenced. The vmhA gene contains an open reading frame consisting of 2232 nucleotides which can code for a protein of 744 amino acids with a predicted molecular mass of 83,059. The similarity of amino acid sequence shows 81.6% identity with Vibrio cholerae El Tor hemolysin.
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Affiliation(s)
- G T Kim
- RCOID and Department of Biotechnology and Bioengineering, Pusan, South Korea
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