http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Choi, Seung‐,Hoon,Hwang, Daesub,Kim, Dong‐,Young,Kervella, Yann,Maldivi, Pascale,Jang, Sung‐,Yeon,Demadrille, Renaud,Kim, Il‐,Doo WILEY‐VCH Verlag 2013 Advanced Functional Materials Vol.23 No.25
<P>Highly porous amorphous Zn<SUB>2</SUB>SnO<SUB>4</SUB> electrodes are prepared using electrospinning techniques and combined with organic or ruthenium dyes to fabricate dye‐sensitized solar cells. As reported by Sung‐Yeon Jang, Renaud Demadrille, Il‐Doo Kim, and co‐workers on page 3146, the devices based on 3‐μm‐thick electrodes and the organic dyes demonstrate significantly improved performances compared to those using the ruthenium complex. Using this approach, solar cells with power conversion efficiencies up to 3.7% are obtained. </P>
Doo‑Won Kim,Dae Ho Kim,Sung Ryong Kim,Bo‑Hye Kim,Yun Hyuk Bang,Duck Joo Yang,Go Bong Choi,Yoong Ahm Kim,Kap Seung Yang 한국탄소학회 2019 Carbon Letters Vol.29 No.5
This study demonstrates that low processing rate for producing polyacrylonitrile (PAN)-based carbon fiber is a critical to obtain a homogeneous radial microstructure with high resistance to oxidation, thereby resulting in their improved mechanical strength. The dry-jet wet spun PAN organic fibers were processed (e.g., stabilized and then carbonized) utilizing two different rates; one is 1.6 times longer than the other. The effect of processing rate on the microstructural evolutions of carbon fibers was analyzed by scanning electron microscopy after slow etching in air, as well as Raman mapping after graphitization. The rapidly processed fiber exhibited the multilayered radial structure, which is caused by the radial direction stretching of the extrusion in the spinning. In case of the slowly processed fiber, the layered radial structure formed in the spinning process was changed into a more homogeneous radial microstructure. The slowly processed fibers showed higher oxidation resistance, higher mechanical properties, and higher crystallinity than the rapidly processed one. Raman mapping confirmed that the microstructure developed during spinning was sustained even though fiber was thermally treated up to 2800 °C.
Protective effect of betaine against galactosamine-induced acute liver injury in rats
Choi, Yeo Jin,Na, Jong Deok,Jun, Doo Sung,Kim, Young Chul Elsevier 2018 Journal of Functional Foods Vol.44 No.-
<P><B>Abstract</B></P> <P>We investigated the protective effect of betaine against galactosamine (GalN)-induced acute hepatic injury. Male rats received betaine from 2 wk prior to GalN treatment. Betaine supplementation inhibited the elevation of serum enzyme activities and the histopathological changes induced by GalN challenge. However, hepatic lipid peroxidation, glutathione levels, and oxidative DNA damage were unaffected by either GalN or betaine treatment. GalN treatment suppressed ornithine decarboxylase (ODC) expression and decreased putrescine levels in liver, both of which were prevented by betaine supplementation. In H4IIE cells, treatment with betaine or <I>S</I>-adenosylmethionine provided complete protection against GalN-induced cytotoxicity. Addition of difluoromethylornithine, an irreversible ODC inhibitor, abolished the protective effect of betaine and <I>S</I>-adenosylmethionine<B>,</B> indicating that depletion of putrescine is critically implicated in GalN-induced cytotoxicity. These results suggest that the beneficial effect of betaine against GalN-induced hepatotoxicity can be attributed to the improvement of polyamine metabolism via elevation of <I>S</I>-adenosylmethionine availability in the liver.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Betaine prevents GalN-induced liver injury both <I>in vivo</I> and <I>in vitro.</I> </LI> <LI> Induction of liver injury by GalN does not involve oxidative stress. </LI> <LI> GalN-induced liver injury is associated with impairment of the polyamine metabolism. </LI> <LI> By increasing SAM, betaine improves the polyamine metabolism dysregulated by GalN. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Choi, Sung-Hee,Kim, Il-Doo,Dhungana, Sanjeev Kumar,Park, Kwangsoo Korean Society of Food Science and Technology 2019 한국식품과학회지 Vol.51 No.6
Of all the various types of tea that are available, Pu-erh tea has attracted much attention because of its healthpromoting effects. The objective of this study was to investigate the physicochemical and antioxidant properties of two types of Pu-erh tea, Gushu Pu-erh and typical Pu-erh, extracted at 80 and 100℃, respectively. The Gushu Pu-erh extracts showed lower pH but higher antioxidant potential at both the temperatures, as compared to the typical Pu-erh. The mineral content of the tea extracts was greater at 100℃ than at 80℃. Among the seven categories of the flavor compounds that were detected, the peak area of esters was the highest in the Gushu Pu-erh extracts. The type of tea and the extraction temperature significantly affected the physicochemical and functional properties of these tea extracts. This study revealed that Gushu Pu-erh extracted at 100℃ for 3 min with 30 s of shaking provides better results in terms of the antioxidant potential and mineral content.
Doo-Ho Lee,Yeon Ho Park,Seok Won Choi,Kug Hyun Nam,Sang Tae Choi,Doojin Kim 대한외과학회 2021 Annals of Surgical Treatment and Research(ASRT) Vol.101 No.6
Purpose: In June 2016, the Model for End-Stage Liver Disease (MELD) score was employed in South Korea instead of the Child-Turcotte-Pugh (CTP) score. This study compared the outcomes of deceased donor liver transplantation (DDLT) before and after the MELD system application. Methods: This retrospective study reviewed 48 patients who underwent DDLT for end-stage liver disease at a single tertiary referral center between January 2014 and December 2018. The patients were categorized into the pre-MELD (22 patients) and post-MELD (26 patients) groups. The demographics, postoperative outcomes, and overall survival time were evaluated between the 2 groups. Results: The 2 groups had no differences in age, sex, ABO type, etiology for liver transplantation, CTP-score, operation time, cold ischemic time, and amount of red blood cell transfusion, although their MELD score differed significantly (post-MELD group, 36.2 ± 4.9; pre-MELD group, 27.7 ± 11.8; P < 0.001). The post-MELD group has longer intensive care unit stay (11.2 ± 9.5 days vs. 5.7 ± 4.5 days, P = 0.018) and hospital stay than the pre-MELD group (36.8 ± 26 days vs. 22.8 ± 9.3 days, P = 0.016). The 1-year survival rate was lower in the post-MELD group (61.5% vs. 86.4%, P = 0.029). Conclusion: After MELD allocation, patients with high MELD scores had increased DDLT and consequently required a longer recovery time, which could negatively affect survival. According to the experience of a small-volume center, these problems were related to both severe organ shortages in South Korea and MELD allocation.
Doo Jin Choi,Jae Kweon Park,Sung Min Kim,Woo Jung Kim,Hye Ran Moon,Yong Il Park 한국당과학회 2010 한국당과학회 학술대회 Vol.2010 No.1
A novel polysialic acid-specific endo-sialidase referred to Endo-PS was purified from the culture filtrate of Pseudomonas fluorescens JK-0412 to apparent homogeneity and has a subunit molecular mass of 20 kDa. The purified enzyme Endo-PS has a molecular weight of 110 kDa by native-PAGE, suggesting that the active enzyme is a hexamer. Although 12 residues of N-terminal amino acid sequence of Endo-PS showed 75% identity with 21-kDa chitin binding protein CBP21 of Serratia marcescens 2170, no significant homology with other known proteins was observed. The specific activity of Endo-PS toward an artificial substrate 4-methylumbelliferyl-sialic acid (4-MU-Neu5A) was determined to be 16 nmole/mg/min with Km value of 0.08 mM. The enzyme was maximally active at an optimal temperature of 37℃ and pH 8. It possesses the ability to only hydrolyze natural substrate α2-8 linked homo-polysialic acid (or colominic acid), but not α2-3 or α2-6 sialyllactoses. Under optimal condition, sialyloligosaccharides ranging from dimer up to 30 residues long liberated from the cleavage of polysialic acid in the function of time were identified by high performance anion-exchange chromatography (HPAEC). Taken together these results suggest that the biochemical properties of Endo-PS purified from the culture filtrate of P. fluorescens JK-0412 are specificfor polysialic acid, referred as a novel endo-polysialidase, reporting first about the properties of non-pathogenic bacterial-derived endo-sialidase.
Sung-Hwan Lee,Eun Wha Choi,Doo Kim 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.2
Dehydration, electrolyte disturbance, and acid-base imbalance are the most significant consequences of diarrhea in calves. We aimed to determine blood gas, hematological, electrolyte, and biochemical values and investigate the relationship between the physical status and blood parameters in Korean native calves (KNCs) with diarrhea. One hundred eighty KNCs with diarrhea (age < 75 days) were investigated. Blood samples were collected from the external jugular vein and analyzed using a portable clinical blood gas analyzer. The measured parameters were statistically compared according to the status of physical activity, dehydration, or prognosis. The mean values of parameters in the Calves with diarrhea showed metabolic acidosis, hyponatremia, and azotemia. The mean values of potassium, chloride, hematocrit, and hemoglobin were in the upper limit of their reference ranges. More than 75% of the calves had metabolic acidosis caused by bicarbonate loss, and 63.6% had high blood urea nitrogen (BUN) values. Moreover, BUN showed the highest correlation with the physical activity status and dehydration. pH, base excess of the extracellular fluid (BE), anion gap, potassium, hematocrit, bicarbonate, and hemoglobin were closely correlated with physical deterioration and dehydration (p < 0.001). BUN, pH, BE, and anion gap were closely correlated with physical deterioration and dehydration. These correlations between clinical symptoms and blood gas parameters can be clinically relevant in predicting the status of parameters according to clinical symptoms.