http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
( Sang-yeop Lee ),( Sung Ho Yun ),( Geul Bang ),( Chang-seop Lee ),( Seung Il Kim ) 한국질량분석학회 2021 Mass spectrometry letters Vol.12 No.3
Scrub typhus is an acute febrile disease caused by the pathogenic bacterium Orientia tsutsugamushi, belonging to the Rickettsiaceae family. The shotgun proteomic analysis was performed using the sera of scrub typhus patients to identify the proteins having their origin in O. tsutsugamushi. Three different databases approaches were used for the identification of the proteomes. We identified the RsmD, an RNA methyltransferase as the commonly detected protein from all three approaches. This protein was not detected in the sera of healthy negative controls. We believe that this protein is a potential biomarker of Orientia tsutsugamushi present in the sera of scrub typhus patients.
Sang June Park,Moonoh Kim,Jun-Yeop Lee,Hang-Rae Cho,Suil Bang 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
Safety for the radioactive waste disposed of in the disposal facility should be secured through safety assessment in consideration of the various situations. In this study, the influence and correlation of EDTA and ISA, which are the factors that can impede the safety of the disposal facility, were analyzed using the PHREEQC computational code. Thermodynamic database (TDB) of Andra, specific ion interaction theory (SIT) model as ionic strength correction model, radionuclides (Ni, Am, Pu) were adopted to perform the calculation on the distribution of chemical species by pH. According to the results, EDTA dominated the system and the effect of ISA is relatively small for the distribution of the chemical species of divalent and trivalent cations in neutral and weak base conditions. In the case of the tetravalent cations, the effect of ISA increased compared to the previous case especially in the strong base conditions. In conclusion, EDTA has a more significant effect on the system than ISA under the environment of the domestic disposal facility. Furthermore, when EDTA and ISA are present simultaneously in the system, the effects of two materials are inversely proportional and this characteristic should be considered during the safety assessment.
Improving Culture Performance and Antibody Titer in CHO Cell Fed-batch Culture by Controlling pH
Sang Yeop LEE,Seungjib JEON,Mi Rae KIM,Hyejeong HEO,Byung Cheon LEE,Joon-Chul LEE 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
Mammalian cell culture is most common industrial process for the production of recombinant proteins. However, higher cell density and titer are still limited due to factors such as excessive metabolites production, nutrients limitation, and high osmolality. Lactate is the major product from glucose metabolism, and lactate accumulation has been demonstrated to inhibit growth rate and negatively affect antibody production in mammalian cells. To partly overcome this factor, we investigated a simple method using pH control in Chinese hamster ovary (CHO) cells. We performed CHO-DG44 fed-batch cultures under pH conditions (6.9 and 7.0) using rocking bioreactor. As a result, cells grown under low pH condition produced lactate approximately 70% lower than cells grown under high pH condition. We also found that peak viable cell density (PVCD) and final antibody titer were increased in fed-batch culture under low pH condition. Taken together, our results demonstrate that fed-batch culture under pH of 6.9 improves the PVCD and titer in CHO cell culture.Mammalian cell culture is most common industrial process for the production of recombinant proteins. However, higher cell density and titer are still limited due to factors such as excessive metabolites production, nutrients limitation, and high osmolality. Lactate is the major product from glucose metabolism, and lactate accumulation has been demonstrated to inhibit growth rate and negatively affect antibody production in mammalian cells. To partly overcome this factor, we investigated a simple method using pH control in Chinese hamster ovary (CHO) cells. We performed CHO-DG44 fed-batch cultures under pH conditions (6.9 and 7.0) using rocking bioreactor. As a result, cells grown under low pH condition produced lactate approximately 70% lower than cells grown under high pH condition. We also found that peak viable cell density (PVCD) and final antibody titer were increased in fed-batch culture under low pH condition. Taken together, our results demonstrate that fed-batch culture under pH of 6.9 improves the PVCD and titer in CHO cell culture.
Lee, Won-Kyu,Lee, Sang-Yeop,Na, Jung-Hyun,Jang, Sung-Woo,Park, Chan-Ryang,Kim, Soo-Youl,Lee, Si-Hyeong,Han, Kyou-Hoon,Yu, Yeon-Gyu Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.6
Nopp140 is a highly phosphorylated protein that resides in the nucleolus of mammalian cell and is involved in the biogenesis of the nucleolus. It interacts with a variety of proteins related to the synthesis and assembly of the ribosome. It also can bind to a ubiquitous protein kinase CK2 that mediates cell growth and prevents apoptosis. We found that Nopp140 is an intrinsically unfolded protein (IUP) lacking stable secondary structures over its entire sequence of 709 residues. We discovered that mitoxantrone, an anticancer agent, was able to enhance the interaction between Nopp140 and CK2 and maintain suppressed activity of CK2. Surface plasma resonance studies on different domains of Nopp140 show that the C-terminal region of Nopp140 is responsible for binding with mitoxantrone. Our results present an interesting example where a small chemical compound binds to an intrinsically unfolded protein (IUP) and enhances protein-protein interactions.
Study on the Release of Bentonite Colloids by Clay Chip-based Microfluidics
Sang-Ho Lee,Ki Jong Jang,Jinseok Kim,Seung Yeop Lee,Jang-Soon Kwon 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
Colloid-facilitated migration has been significantly concerned with the acceleration of the radionuclide mobility in the HLW repository. In the repository system, the compacted bentonite, which is the buffer material, could be the major source for colloid generation; hence, the understanding of colloid generation from the bentonite is the essential to expect the colloid-facilitated radionuclide migration. This study aimed to investigate the colloid generation using a bentonite-based micro-scale flow path system, which called microfluidics. In order to fabricate the microfluidics, direct milling method was applied to make a mold by computer numerical control. The fabricated mold applied to prepare the microfluidic chip by Polydimethylsiloxane (PDMS), in which the size of microchannel was designed to be one micrometer. Initially, sylgard 184 and curing agent mixed and stirred for 10 min, afterwards the bubbles in the paste was removed in the vacuum desiccator for 30 min. Then the paste was poured into the mold, and finally dried for 4 hours at 80°C in a dry oven. The compacted Ca-bentonite chip was prepared by the cold isostatic pressing (CIP) method with the dry density of 1.6 g·cm?3. The microfluidic chip and compacted bentonite chip were assembled by an acryl jig, the flow rate was adjusted by 20 mL syringe equipped syringe pump. The degree of colloid generation accompanied with the erosion of bentonite was gravimetrically examined after the experiment. The effect of the pH and ionic strength on the colloid formation was investigated through the particle size, stability and aggregation. To the best of our knowledge, this is the first examination for the colloid generation using microfluidics; these results would give information to understand the colloid formation from the compacted Ca-bentonite in the HLW repository system.