Enhancing Cancer Immunotherapy using Biomaterials

Chun Gwon PARK 한국생물공학회 2019 한국생물공학회 학술대회 Vol.2019 No.10

Production of microbial lipid by <i>Cryptococcus curvatus</i> on rice straw hydrolysates

Park, Gwon Woo,Chang, Ho Nam,Jung, Kwonsu,Seo, Charles,Kim, Yeu-Chun,Choi, Jae Hyung,Woo, Hee Chul,Hwang, In-ju Elsevier 2017 Process biochemistry Vol.56 No.-

<P><B>Abstract</B></P> <P>Microbial biolipids/biodiesels derived from volatile fatty acids (VFAs) can be a valuable alternative to plant oils if optimum fermentation conditions are determined. VFAs were used for cell mass and microbial lipid production by <I>Cryptococcus curvatus</I>. The lipid content in the cells increased up to 48% and 28% in batch cultures with the use of 20g/L glucose and 6g/L of VFAs as the carbon source, respectively. In this study, <I>C. curvatus</I> used VFAs as a carbon source via anaerobic digestion of rice straw hydrolysates. VFAs produced from rice straw resulted in yield of 0.43g VFAs/g substrate and 40% higher specific growth rate(0.305h<SUP>−1</SUP>) than synthetic VFAs. The highest fatty acid composition observed was C18:1, was obtained using glucose and VFAs as the carbon source to yield a cetane number of 56–59, which is suitable for biodiesel production. The cost of microbial lipids was estimated to be 0.30–1.15 USD/L given 0–150 USD/ton of VFAs cost for a yield of 0.17g/g of lipids. Thus, VFAs can be a suitable carbon source for economical biodiesel production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Rice straw, one of the most abundant agricultural byproduct biomass, can be converted to volatile fatty acids (VFAs) via anaerobic digestion. </LI> <LI> Microbial lipid can be produced from the rice-straw VFAs by an oleaginous yeast <I>Cryptococcus curvatus.</I>. </LI> <LI> Biomass and lipid content can be controlled by the pH and initial VFAs concentration. </LI> <LI> Specific growth rate of VFAs from rice straw hydrolysates is 40% higher than that of synthetic VFAs in yeast cultivation. </LI> <LI> Microbial lipid from the rice-straw VFAs has a potential of economic biodiesel production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhancement of volatile fatty acids production from rice straw via anaerobic digestion with chemical pretreatment.

Park, Gwon Woo,Kim, Ilgook,Jung, Kwonsu,Seo, Charles,Han, Jong-In,Chang, Ho Nam,Kim, Yeu-Chun Springer-Verlag 2015 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.38 No.8

<P>Rice straw is one of the most abundant renewable biomass sources and was selected as the feedstock for the production of volatile fatty acids (VFAs) from which microbial biodiesel can be produced. Two kinds of chemical pretreatments involving nitric acid and sodium hydroxide were investigated at 150?C with 20?min of reaction time. The nitric acid pretreatment generated the most hemicellulose hydrolyzate, while significant reduction of the lignin occurred with sodium hydroxide pretreatment. Anaerobic digestion of 20?g/L rice straw yielded 6.00 and 7.09?g VFAs/L with 0.5?% HNO3 and 2?% NaOH, respectively. The VFAs yield with 2?% NaOH was 0.35?g/g.</P>

Volatile fatty acids derived from waste organics provide an economical carbon source for microbial lipids/biodiesel production

Park, Gwon Woo,Fei, Qiang,Jung, Kwonsu,Chang, Ho Nam,Kim, Yeu-Chun,Kim, Nag-jong,Choi, Jin-dal-rae,Kim, Sangyong,Cho, Jaehoon Wiley (John WileySons) 2014 Biotechnology journal Vol.9 No.12

Voltage Source Equipment for the Grid Fault Testing and Analysis of Total Harmonic Distortion According to PWM Methods

Gwon, Jin-Su,Kim, Chun-Sung,Kang, Dae-Wook,Park, Jung-Woo,Kim, Sungshin The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.6

Renewable energy is being spotlighted as the electric power generating source for the next generation. Due to an increase in renewable energy systems in the grid system, their impact on the grid has become non-negligible. Thus, many countries in the world, including Europe, present their own grid codes for grid power conversion devices. In order to experiment with these grid codes, grid fault test equipment is required. This paper proposes both equipment and a control method, which are constructed with a 7-level cascaded H-bridge converter, that are capable of generating various grid faults. In addition, the Pulse Width Modulation (PWM) method for multilevel converters is compared and analyzed. The proposed structure, the control method, and the PWM method are verified through simulation and experimental results.

A comprehensive study on volatile fatty acids production from rice straw coupled with microbial community analysis.

Park, Gwon Woo,Seo, Charles,Jung, Kwonsu,Chang, Ho Nam,Kim, Woong,Kim, Yeu-Chun Springer-Verlag 2015 BIOPROCESS AND BIOSYSTEMS ENGINEERING Vol.38 No.6

<P>Rice straw is one of the most abundant renewable energy sources available. Through anaerobic acidogenesis, the substance of rice straw can be converted to volatile fatty acids (VFAs). VFAs itself is of value and is a precursor to biofuels. Hence, it can be converted to mixed alcohols by addition of hydrogen, and biodiesel can be produced as a carbon source for oleaginous microorganism. To maximize VFAs production during anaerobic digestion (AD), response surface analysis (RSM) was carried out with respect to temperature, substrate concentration, and pH variables. Optimization results showed maximal VFAs concentration of 12.37 g/L at 39.23 C, 52.85 g/L of rice straw, and pH 10. In quantification of microbial community by quantitative polymerase chain reaction, the bacterial profile showed that the growth of methanogens was effectively inhibited by methanogenic inhibitors. Furthermore, 454 pyrosequencing showed that members of the Ruminococcaceae family, capable of hydrolyzing lignocellulosic biomass, were the most dominant species in many RSM trials. This study provided a useful insight on the biological improvement of AD performance through the combinational linkage between process parameters and microbial information.</P>

초등학교 아동들의 환경인식 조사

박춘배 ( Chun Bae Park ),백남권 ( Nam Gwon Back ) 한국환경과학회 2011 한국환경과학회지 Vol.20 No.5

The sense of crisis on seriousness of earth environment is gradually getting greater and the importance of environment education followed by this trend is being highlighted. As an environment friendly New Environmental Paradigm opposed to the human Dominant Social Paradigm on the existing environment is on the rise, the environment education considers not only the perceptive field, but the definitive field and behavioral pattern to follow as important values. Accordingly, the basic awareness of students on environment was found out in order to perform a proper environment education and tried to find out the behavior pattern that the students have on environment on this basis . For the research tool of this study, the one that has revised the Revised NEP Scale for elementary school students which Geum, Ji Hun·Kim, Jin Mo have validated the feasibility and reliability while the test paper was prepared by dividing into recycling behavior, energy preservation behavior and source of information. The target of this study was 600 students in sixth grade of elementary school residing in Kimhae, Gyeongsangnamdo while the mean, average, standard deviation, independent t-test and correlation analysis were performed using SPSS 15.0 statistics program for a total of 462 copies including 235 copies from male students and 227 copies from female students. The results of this study are as follows. First, everyone had high pro-NEP tendencies on the environmental problem with 4.14. On the other hand, the anti-NEP did not have high awareness standard with 2.98. Second, the awareness level on resource recycling was shown as being quite high with 4.05. Between NEP and resource recycling, a positive correlation of r=.155 was shown so that the awareness level on resource recycling was getting quite high as the awareness on environment problem was getting higher. Third, the awareness level on energy saving activity was shown as being very high with 3.0. Between NEP and resource recycling, a positive correlation of r=.210 so that the awareness level on energy saving was getting quite high as the awareness on environment problem was getting higher. Fourth, for the source of information on environmental problems of region, our country and global village, the television and internet were shown as main sources of information while the ratio of positive answers on teachers and region as sources of information was shown as quite low.

포항 대형산불지역 전소피해 시설물들의 피해특성분석

권춘근(Gwon, Chun-Geun),이시영(Lee, Si-Yeong),염찬호(Yeom, Chan-Ho),박흥석(Park, Heung-Seok) 한국화재소방학회 2013 한국화재소방학회 학술대회 논문집 Vol.2013 No.추계

본 연구는 2013년 3월 9일부터 3월 10일 동안 79ha의 산림피해와 110동의 시설물 피해를 준 포항산불에 대하여 산림 내 시설물들의 산불피해 특성분석을 위하여 현장조사를 실시하였다. 조사대상물은 전소피해를 입은 주택 10개소, 창고 1개소 등 총 11개소에 대하여 2013년 3월부터 5월까지 현지조사를 실시하였다. 조사항목은 시설물주변의 지형적 특성, 임상 및 이격거리, 수관화발생여부, 시설물의 재질 등 총 5개 항목에 대하여 피해특성을 분석하였으며, 전소지역의 피해 특성은 지형의 경우 골짜기막장형 지형, 주변임상은 침엽수, 임분밀도는 중임분, 산림과의 평균 이격거리는 3.1m, 산불의 종류는 수관화 발생지역 이었으며, 시설물의 재질은 슬레이트, 조립식 판넬인 것으로 조사되었다.

성인 미세변화신증후군의 치료 반응과 재발에 관련된 인자

박정환 ( Park Jeong Hwan ),허남주 ( Heo Nam Ju ),이정표 ( Lee Jeong Pyo ),박동준 ( Park Dong Jun ),성은영 ( Seong Eun Yeong ),주권욱 ( Ju Gwon Ug ),임춘수 ( Im Chun Su ),김연수 ( Kim Yeon Su ),안규리 ( An Gyu Li ),한진석 ( Han Jin 대한신장학회 2004 Kidney Research and Clinical Practice Vol.23 No.3

배경 : 미세변화신증후군은 우리나라에서는 성인 신증후군 중에서 제일 흔한 원인 질환이다. 방법 : 1979년 1월부터 2002년 12월까지 신조직 검사로 확진된 일차성 미세변화신증후군 환자로 16세 이상 성인이면서 최소 6개월 이상 추적 관찰된 환자들을 대상으로 치료에 대한 반응과 재발에 관련된 인자들을 분석하였다. 결과 : 대상은 94명으로 남녀비는 1.6:1이었으며, 초진 시 연령은 평균 30.5 (16-73)세였고, 관찰 기간은 66 (6-297)개월이었다. 스테로이드 초치료를 한 81명 중 완전관해가 68명 (84%), 부분관해 7명 (8.6%), 저항성을 보인 경우는 6명 (7.4%)이었다. 4주까지 완전관해가 온 47명과 그 이후에 완전관해가 오거나 부분관해 또는 저항성을 보인 34명을 비교할 때, 후자에 남자가 더 많았고 (p=0.04), 신기능 저하군 (p=0.01)이 더 많았다. Cyclophosphamide와 스테로이드 복합요법 초치료를 한 환자는 10명으로 이들은 모두 완전관해가 왔다. 모든 초치료로 완전관해가 왔던 79명의 환자에서 관찰 기간 동안 재발 횟수는 0.37회/환자/년였다. 40세 이하군 (61명)과 40세 초과군 (18명)으로 나누었을 때 각각 재발 횟수는 0.44와 0.15로 후자에서 재발 횟수가 적었다 (p=0.02). 완전관해 후 관해 유지 기간을 보았을 때 40세 초과군 (p=0.005), 1일 단백뇨 10 g 이하군 (p=0.04)이 관해가 더 오래 유지되었다. 결론 : 신기능 저하가 있는 환자는 치료에 대한 반응이 좋지 않았고, 고연령 군이 재발이 적고 관해 유지 기간이 길었으며 단백뇨량이 적을 때 관해 유지 기간이 길었다. Background : Minimal change nephrotic syndrome (MCNS) is the most common cause of idiopathic nephrotic syndrome in Korea, not only in children but also in adults. Methods : We reviewed the medical records of patients older than 16 years who were diagnosed MCNS by percutaneous renal biopsy between 1979 and 2002 and followed more than 6 months there after. Results : Of total 94 patients enrolled, there were 58 men and 36 women (male to female 1.6 : 1), the mean age of onset was 30.5 (16-73) years, and the mean follow-up period was 66 (6-297) months. Of 81 patients who were initially given corticosteroid, complete remission (CR) was observed in 68 (84%), partial remission in 7 (8.6%), and failure to remission in 6 (7.4%). In comparison of the 47 patients who showed CR by the 4th week with the group who showed CR after 4 weeks plus who did not show CII after all, male (p=0.04) and renal insufficiency (p=0.01) were more dominant in the latter group. All of 10 patients who were initially given the combination of cyclophosphamide and corticosteroid showed CR. The mean number of relapse per patient per year was 0.37 in 79 patients who achieved CR with initial treatment, 0.44 in 61 patients younger than 40 years, and 0.15 in 18 patients older than 40 years (p=0.02). Remission was maintained longer in patients older than 40 years (p=0.005), and in those with proteinuria less than 10 grams per day (p=0.04). Conclusion : Among patients with MCNS, those who presented with initial renal insufficiency show a less favorable response to corticosteroid. Patients older than 40 years show less frequent relapse and longer duration of remission. (Korean J Nephrol 2004;23 (3):419- 428)

연구논문 : 부동산금융시장의 스트레스테스트에 관한 연구

박천규 ( Chun Gyu Park ),지대식 ( Dae Sik Ji ),권수연 ( Soo Yun Gwon ) 전남대학교 지역개발연구소 2011 지역개발연구 Vol.43 No.1

이 연구는 부동산금융시장에 대한 스트레스테스트 모형을 구축하고, 여러 시나리오에 따라 부동산금융시장의 스트레스테스트를 하는 데 목적이 있다. 부동산금융시장을 수요자금융시장과 개발금융시장으로 구분하여 스트레스테스트를 실시하였다. 스트레스테스트는 대표적인 신용리스크측정모형 중 스트레스테스트에 가장 적합하다고 알려진 McKinsey사의 Credit Portfolio View(CPV) 모형을 이용하였다. 부동산금융시장의 스트레스테스트 결과를 종합하고 시사점을 정리하면 다음과 같다. 첫째, 소비자금융시장의 부실이 개발금융시장으로 전이되는 양상을 보이고 있다. 둘째, 소비자금융시장은 실업률 상승 스트레스에 상대적으로 취약한 것으로 보인다. 셋째, 개발금융시장은 가계대출연체율, 주택가격 변화에 매우 민감하다. 넷째, 주택가격의 안정은 부동산금융시장의 부실방지에 매우 중요한 과제이다. 다섯째, 개발금융시장은 소비자금융시장에 비해 거시경제변수에 크게 취약한 편이다. 여섯째, 본격적인 출구전략은 경제가 충분히 회복되었다고 판단될 때 시행될 필요가 있다. This study aims to carry stress test on real estate financial market using the Credit Portfolio View(CPV) model. The summary of the findings and the implications of the study is as follows. First, the consumer financial market`s risk moves to the construction financial market. Second, the consumer financial market is vulnerable to unemployment rate. Third, the construction financial market is vulnerable to housing price and default rate. Forth, the stabilization of housing market is very important for prevention from real estate financial market failure. Sixth, a full-scale exit strategy should be started when the economy recovers sufficiently.