• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.99-102
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• 2005

Organic solvents are widely used in biotransformation systems. There are many efforts to reduce the consumption of organic solvents because of their toxicity to the environment and human health. In recent years, several groups have started to explore novel organic solvents called room temperature ionic liquids in order to substitute conventional organic solvents. In this work, lipase-catalyzed transesterification in several uni- and bi-phasic systems was studied. Two representative hydrophobic ionic liquids based on 1-butyl-3-methylimidazolum coupled with hexafluorophosphate ([BMIM][$PF_6$]) and bis[{trifluoromethylsulfonyl} imide] ([BMIM] [$Tf_{2}N$]) were employed as reaction media for the transesterification of n-butanol. The commercial lipase, Novozym 435, was used for the transesterification reaction with vinyl acetate as an acyl donor. The conversion yield was increased around $10\%$ in a water/[BMIM][$Tf_{2}N$] bi-phasic system compared with that in a water/hexane system. A higher distribution of substrates into the water phase is believed to enhance the conversion yield in a water/[BMIM][$Tf_{2}N$] system. Partition coefficients of the substrates in the water/[BMIM][$Tf_{2}N$] bi-phasic system were higher than three times that found in the water/hexane system, while n-butyl acetate showed a similar distribution in both systems. Thus, RTILs appear to be a promising substitute of organic solvents in some biotransformation systems.

• 한국동물생명공학회지
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• 제36권3호
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• pp.162-167
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• 2021

Camel (camelus dromedarius) is a unique large mammalian species that can survive harsh environmental conditions and produce milk, meat, and wool. Camel reproduction is inferior when compared to other farm animal species such as cattle and sheep. Several trials have been reported to increase camel reproduction and production through assisted reproductive techniques (ARTs) such as in vitro fertilization and cloning. For these reasons, obtaining enough mature oocytes is a cornerstone for ARTs. This demand would be improved by the oocyte in vitro maturation (IVM) systems. In this review, the current approaches and views from different laboratories using ARTs and the IVM to produce embryos in vitro in camel species. For the last two decades, conventional IVM system was the common approach, however, recently the bi-phasic IVM system has been introduced and showed promising improvement in IVM of camel oocytes. Detailed studies are needed to understand camel meiosis and IVM to efficiently increase the production of this species.

• Composites Research
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• 제36권6호
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• pp.416-421
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• 2023

Multifunctional composite materials capable of both load-carrying and energy functions are promising innovative candidates for the advancement of contemporary technologies owing to their relative feasibility, cost-effectiveness, and optimized performance. Carbon fiber (CF)-based structural batteries utilize the graphitic inherent structure to enable the employment of carbon fibers as electrodes, current collectors, and reinforcement, while the matrix system is an ion-conduction and load transfer medium. Although it is possible to enhance performance through the modification of constituents, there remains a need for a systematic design methodology scheme to streamline the commercialization of structural batteries. In this work, a bi-phasic epoxy-based ionic liquid (IL) modified structural battery electrolyte (SBE) was developed via thermally initiated phase separation. The polymer's morphological, mechanical, and electrochemical characteristics were studied. In addition, the interfacial shear strength (IFSS) between CF/SBE was investigated via microdroplet tests. The results accentuated the significance of considering IFSS and matrix plasticity in designing composite structural batteries. This approach is expected to lay the foundation for realizing smart structures with optimized performance while minimizing the need for extensive trial and error, by paving the way for a streamlined computational design scheme in the future.

• 대한의용생체공학회:의공학회지
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• 제25권2호
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• pp.151-156
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• 2004

편마비 환자에서 상지 기능을 효과적으로 회복시키기 위하여 근전도 유발 기능적 전기자극기 개발과 편마비 환자를 대상으로 손목, 수지신전 운동 시 가장 효과적으로 근수축을 감지 할 수 있는 위치와 전기 자극 시 가장 이상적인 손목, 수지 신전 운동이 일어나는 부위를 탐색하여 두 부과가 일치하는 이상적인 전극부착 위치를 설정하였다. 1) 전기자극 시스템으로 EMC 계측부, 정전류 회로부를 개발하고 프로그램으로는 근전도 유발 전기자극기와 Passive FES의 동작이 가능한 형태로 개발하였다 자극조건은 주파수 35 Hz, 펄스폭 150 ${\mu}\textrm{s}$, 비대칭적 이상성 파형을 선택하였다. 2) 상지 편마비 환자 15명을 대상으로 전완의 근위부 1/2부위를 12개의 영역으로 나눈 후 근위부의 외측으로부터 영역의 순서를 정하였다. 각 영역에서 환자의 손목을 신전 하였을 때 근전도 유발 자극기가 감지하는 활동전위의 진폭을 측정하였으며 가장 크게 감지된 영역은 4, 5 영역이었고, 전기자극을 시행하였을 때 손목과 수지부위가 신전 되는 모양이 이상적인 영역은 4, 5, 7, 8 영역이었다. 근전도 유발 전기자극을 시행하였을 때 근 수축을 감지하여 근전도 유발 전기자극이 일어나는 일련의 과정이 이상적인 영역은 해부학적으로 4, 5 영역이었다.