• Title/Summary/Keyword: Desorption Time

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Preliminary Study on the Phase Transition of White Precipitates Found in the Acid Mine Drainage (산성광산배수에서 발견되는 흰색침전물의 상전이에 대한 예비 연구)

  • Yeo, Jin Woo;Kim, Yeongkyoo
    • Journal of the Mineralogical Society of Korea
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    • v.32 no.2
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    • pp.79-86
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    • 2019
  • The white aluminum phases in acid mine drainage usually precipitates when mixed with stream waters with relatively high pH. The minerals in white precipitates play important roles in controlling the behavior of heavy metals by adsorbing and coprecipitation. By the phase transition of these minerals in white precipitates, dissolution and readsorption of heavy metals may occur. This study was conducted to obtain preliminary information on the phase transition of the mineral phases in white precipitates. In this study, the mineral phase changes in the white precipitates collected from the stream around Dogye Mining Site over time were investigated with different pH values and temperatures. White precipitates consist mainly of basaluminite, amorphous $Al(OH)_3$ and a small amount of $Al_{13}$-tridecamer. During aging, the incongruent dissolution of the basaluminite occurs first, increasing the content of the amorphous $Al(OH)_3$. After that, pseudoboehmite is finally precipitated following the precursor phase of pseudoboehmite. At $80^{\circ}C$, this series of processes was clearly observed, but at relatively low temperatures, no noticeable changes were observed from the initial condition with coexisting basaluminite and amorphous $Al(OH)_3$. At high pH, the desorption of $SO{_4}^{2-}$ group in basaluminite was initiated to promote phase transition to the pseudoboehmite precursor. Over time, the solution pH decreases due to the dissolution and phase transition of the minerals, and even after the precipitation of pseudoboehmite, only the particle size slightly increased but no clear cystal form was observed.

Comparison of sample storage containers for the analysis of volatile organic compounds (VOC) (휘발성유기물(VOC) 분석을 위한 시료보관 용기의 비교)

  • Kim, Seokyung;Kim, Dalho
    • Analytical Science and Technology
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    • v.35 no.3
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    • pp.116-123
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    • 2022
  • Polymer bags, metallic canisters, and glass bottles have been used as containers for analyzing the volatile organic compounds (VOCs) in air. In this study, various sampling containers were compared to investigate the short-term stability of VOCs, that is, from the time they are sampled to the time they are analyzed. Polyvinyl fluoride (PVF), polypropylene (PP), polyester aluminum (PE-Al) bags, canisters, and glass bottles were used as sample containers. A 100 nmol/mol standard gas mixture of benzene, toluene, ethylbenzene, m-xylene, styrene, and o-xylene was used for the VOC comparison. Changes in the concentrations of samples stored for 10~20 day in each container were measured using a thermal desorption-gas chromatograph-flame ionization detector (TD-GC-FID). As a result, VOCs stored in a canister and two kinds of amber glass bottles have shown immaterial decreases in concentration in one week, and more than 80 % of the initial concentration was maintained for two weeks. In the case of polymer bags, the concentration of all VOCs, except benzene and toluene, were remarkably decreased below 70% of the initial concentration in one day. Particularly, ethylbenzene, xylene, and styrene have shown dramatic decreases in concentration below 30 % of the initial concentration in all polymer bags in one day.

Metabolic Characteristic of the Liver of Dairy Cows during Ketosis Based on Comparative Proteomics

  • Xu, Chuang;Wang, Zhe;Liu, Guowen;Li, Xiaobing;Xie, Guanghong;Xia, Cheng;Zhang, Hong You
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.1003-1010
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    • 2008
  • The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.

Investigation on Water Purification Effect Through Long-Term Continuous Flow Test of Porous Concrete Using Effective Microorganisms (유용미생물을 이용한 포러스 콘크리트의 장기간 연속흐름 실험을 통한 수질정화 효과 검토)

  • Park, Jun-Seok;Kim, Bong-Kyun;Kim, Woo-Suk;Seo, Dae-Sok;Kim, Wha-Jung
    • Journal of the Korea Concrete Institute
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    • v.26 no.2
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    • pp.219-227
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    • 2014
  • The purpose of this study is to investigate water purification properties of porous concrete by using effective microorganisms through the long-term continuous flow test. To solve the problems such as desorption of conventional microorganisms, in this study, tertiary treatment of the effective microorganisms identified by 16S rDNA sequence analysis was adopted per each step in the manufacturing process of porous concrete. And concentration for optimum continuous flow test and operation conditions through basic experiments according to retention time were investigated. Based on the experimental results, the porous concrete applying effective microorganisms showed no toxicity on the biological water quality and exhibited excellent removal efficiency than normal porous concrete. Therefore, contaminated water quality would be improved by treatment performance investigation of contaminants through long-term continuous flow test. If problems are complemented during the experiment process, it is expected to be able to reduce the non-point pollution sources flowing into river.

Bacterial Identification and Detection of Equol in Korean Soybean Paste (한국 된장에서 Equol의 검출 및 미생물 동정)

  • Woo, Seung-Gyun;Lee, So-Yeon;Choi, Go-Woon;Hong, You-Jin;Lee, So-Min;Park, Kang Gyun;Eom, Yong-Bin
    • Korean Journal of Clinical Laboratory Science
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    • v.47 no.4
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    • pp.286-291
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    • 2015
  • Equol has beneficial effects on human health. Fermented soy products contain equol, and many microbes participate in the equol production process. This study investigated fermented Korean soybean paste, doenjang. Thirty seven doenjang samples collected from different manufacturers were examined. Equol was detected in 3 samples (D2, D13, and D19) at the maximum content of 507 ng/100 g by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fifteen microbial species were isolated and identified by 16S rRNA gene sequence analysis and by matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). Bacillus spp, Paenibacillus spp, Tetragenococcus spp, Stapylococcus spp, and Clostridium species were the predominant bacteria in equol containing doenjang samples.

Protein Patterns on a Corpus Luteum during Pregnancy in Korean Native Cows

  • Chung, Hak-Jae;You, Dong-Min;Kim, Hyo-Ju;Choi, Hye-Young;Lee, Myeong-Suk;Kim, Jin-Bum;Lee, Suck-Dong;Park, Jung-Yong;Lee, Myeung-Sik
    • Reproductive and Developmental Biology
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    • v.34 no.3
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    • pp.263-270
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    • 2010
  • Luteal cells produce progesterone that supports pregnancy. Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism. In the present study, the corpus luteum (CL) in early pregnancy established from luteal phase and pregnant phase was analyzed. The first study determined progesterone changes in the bovine CL at day 19 (early maternal recognition period) and day 90 in mid-pregnancy and compared them to the CL from day 12 of the estrous cycle. CL alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF). Comparing CL from luteal phase to those from pregnant phase counterparts, significant changes in expression level were found in 23 proteins. Of these proteins 17 were not expressed in pregnant phase CL but expressed in luteal phase counterpart, whereas, the expression of the other 6 proteins was limited only in pregnant phase CL. Among these proteins, vimentin is considered to be involved in regulation of post-implantation development. In particular, vimentin may be used as marker for CL development during pregnancy because the expression level changed considerably in pregnant phase CL tissue compared with its luteal phase counterpart. Data from 2-DE suggest that protein expression was disorientated in mid pregnancy from luteal phase, but these changes was regulated with progression of pregnancy. These findings demonstrate CL development during mid-pregnancy from luteal phase and suggest that alternations of specific CL protein expression may be involved in maintenance of pregnancy.

Proteomic Analysis of Cytokinin Induced Proteins in Arabidopsis (단백체를 이용한 애기장대 Cytokinin 유도 단백질의 분석)

  • Liang Ying-Shi;Cha Joon-Yung;Ermawati Netty;Jung Min-Hee;Bae Dong-Won;Lee Chang-Won;Son Dae-Young
    • Journal of Plant Biotechnology
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    • v.32 no.4
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    • pp.251-256
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    • 2005
  • Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. To better understand the molecular mechanisms of cytokinin action, we identified cytokinin related proteins by a proteomic approach. Proteins extracted from control and trans-zeatin treated Arabidopsis seedlings were separated and analyzed by two dimensional gel analysis. Differentially expressed protein spots were identified with peptide mass fingerprinting based on matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and database searching, We obtained ten up-regulated and one down-regulated proteins upon t-zeatin treatment. The expression of the following proteins was induced; pollen allergen like protein, L-ascorbate peroxidase, tetrapyrrole methylase family protein, SGT1 protein homolog, disease resistance related protein, maternal embryogenesis control protein, paxneb related protein, gluthathione S-transferase and IAA amino acid hydrolase homolog.

Characterization of Placental Proteins in Bovine Somatic Cell Clone Fetuses

  • Woo, Jei-Hyun;Ko, Yeoung-Gyu;Kim, Bong-Ki;Kim, Jong-Mu;Lee, Youn-Su;Kim, Nam-Yun;Im, Gi-Sun;Yang, Boung-Chul;Seong, Hwan-Hoo;Jung, Jin-Kwan;Kwun, Moo-Sik;Chung, Hak-Jae
    • Reproductive and Developmental Biology
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    • v.29 no.2
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    • pp.83-91
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    • 2005
  • Somatic cell nuclear transfer in cattle has limited efficiency in terms of production of live offspring due to high incidence of fetal failure after embryo transfer to recipients. Such low efficiency of cloning could possibly arise from abnormal and poorly developed placenta. In the present study the placental proteome in late pregnancy established from in vitro fertilization (IVF) and nuclear transfer (NT) was analysed. Proteome alternation was tested using two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI- TOF). Comparing placenta from NT embryos to those from IVF counterparts, significant changes in expression level were found in 18 proteins. Of these proteins 12 were not expressed in NT placenta but expressed in IVF counterpart, whereas the expression of the other 6 proteins was limited only in NT placenta. Among these proteins, cytokeratin 8 and vimentin are considered to be involved in regulation of post-implantation development. In particular, cytokeratin 8 and vimentin may be used as makers for placental development during pregnancy because their expression levels changed considerably in NT placental tissue compared with its IVF counterpart. Data from 2-DE suggest that protein expression was disorientated in late pregnancy from NT, but this distortion was eliminated with progression of pregnancy. These findings demonstrate abnormal placental development during late pregnancy from NT and suggest that alterations of specific placental protein expression may be involved in abnormal function of placenta.

Synthesis of β-Galactooligosaccharide Using Bifidobacterial β-Galactosidase Purified from Recombinant Escherichia coli

  • Oh, So Young;Youn, So Youn;Park, Myung Soo;Kim, Hyoung-Geun;Baek, Nam-In;Li, Zhipeng;Ji, Geun Eog
    • Journal of Microbiology and Biotechnology
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    • v.27 no.8
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    • pp.1392-1400
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    • 2017
  • Galactooligosaccharides (GOSs) are known to be selectively utilized by Bifidobacterium, which can bring about healthy changes of the composition of intestinal microflora. In this study, ${\beta}-GOS$ were synthesized using bifidobacterial ${\beta}-galactosidase$ (G1) purified from recombinant E. coli with a high GOS yield and with high productivity and enhanced bifidogenic activity. The purified recombinant G1 showed maximum production of ${\beta}-GOSs$ at pH 8.5 and $45^{\circ}C$. A matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the major peaks of the produced ${\beta}-GOSs$ showed MW of 527 and 689, indicating the synthesis of ${\beta}-GOSs$ at degrees of polymerization (DP) of 3 and DP4, respectively. The trisaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose, and the tetrasaccharides were identified as ${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-galactopyranosyl-($1{\rightarrow}4$)-O-${\beta}-{\text\tiny{D}}$-glucopyranose. The maximal production yield of GOSs was as high as 25.3% (w/v) using purified recombinant ${\beta}-galactosidase$ and 36% (w/v) of lactose as a substrate at pH 8.5 and $45^{\circ}C$. After 140 min of the reaction under this condition, 268.3 g/l of GOSs was obtained. With regard to the prebiotic effect, all of the tested Bifidobacterium except for B. breve grew well in BHI medium containing ${\beta}-GOS$ as a sole carbon source, whereas lactobacilli and Streptococcus thermophilus scarcely grew in the same medium. Only Bacteroides fragilis, Clostridium ramosum, and Enterobacter cloacae among the 17 pathogens tested grew in BHI medium containing ${\beta}-GOS$ as a sole carbon source; the remaining pathogens did not grow in the same medium. Consequently, the ${\beta}-GOS$ are expected to contribute to the beneficial change of intestinal microbial flora.

Characteristics of Soy Protein Isolate Films Plasticized by Mixtures of Crystalline and Aqueous Sorbitol or Glycerin (솔비톨 혼합물과 글리세린 가소제에 의한 분리 대두단백질 필름의 특성연구)

  • Kim Ki-Myong;Hanna Milford A.;Choi Won-Seok;Cho Sung-Hwan;Choi Sung-Gil
    • Food Science and Preservation
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    • v.13 no.3
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    • pp.285-291
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    • 2006
  • The effects of sorbitol mixture as plasticizers on moisture sorption property (MSP), water vapor permeability (WVP), color, tensile strength (TS), elongation at break (E), and total soluble matter (TSM) of soy protein isolate (SPI) films were investigated. Two different types of sorbitols, aqueous and crystalline, were added to film-forming solutions in various ratios of crystalline to aqueous (0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25, or 1:0, based on weight). In addition, the characteristics of the SPI films plasticized by sorbitol mixtures and glycerin were compared with moisture sorption rate against time. Sorbitol-plasticized films had higher in TS, but lower in WVP and E than the glycerin-plasticized films. However the properties of SPI films did not differ appreciably by the type of sorbitol added to film-forming solutions. To explain the high solubility and low WVP of sorbitol-plasticized films, cumulative amounts of moisture content gained during adsorption and lost during desorption of films were compared between sorbitol and glycerin-plasticized films. The result suggest that use of sorbitol as a plasticizer for preparing SPI films improves moisture barrier properties of the films. However the high solubility of sorbitol-plasticized films needs to be reduced for improving the functionality of SPI films in potential packaging applications.