• Title/Summary/Keyword: TOF method

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The Importance of the Aging Time to Prepare Cu/ZnO/Al2O3 Catalyst with High Surface Area in Methanol Synthesis

  • Jung, Heon;Yang, Dae-Ryook;Joo, Oh-Shim;Jung, Kwang-Deog
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1241-1246
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    • 2010
  • Ternary Cu/ZnO/$Al_2O_3$ catalysts were prepared by a co-precipitation method. The precursor structures were monitored during the aging. The first precipitate structure was amorphous georgeite, which transformed into the unknown crystalline structure. The transition crystalline structure was assigned to the crystalline georgeite, which was suggested with elemental analysis, IR and XRD. The final structure of precursors was malachite. The Cu surface area of the resulting Cu/ZnO/$Al_2O_3$ was maximized to be 30.6 $m^2$/g at the aging time of 36 h. The further aging rapidly decreased Cu surface areas of Cu/ZnO/$Al_2O_3$. ZnO characteristic peaks in oxide samples almost disappeared after 24 h aging, indicating that ZnO was dispersed in around bulk CuO. TOF of the prepared catalysts of the Cu surface area ranges from 13.0 to 30.6 $m^2/g_{cat}$ was to be 2.67 ${\pm}$ 0.27 mmol/$m^2$.h in methanol synthesis at the condition of $250^{\circ}C$, 50 atm and 12,000 mL/$g_{cat}$. h irrespective of the XRD and TPR patterns of CuO and ZnO structure in CuO/ZnO/$Al_2O_3$. The pH of the precipitate solution during the aging time can be maintained at 7 by $CO_2$ bubbling into the precipitate solution. Then, the decrease of Cu surface area by a long aging time can be prevented and minimize the aging time to get the highest Cu surface area.

Purification of Caudal-Related Homeodomain Transcription Factor and Its Binding Characterization

  • Jeong, Mi-Suk;Hwang, Eun-Young;Kim, Hyun-Tae;Yoo, Mi-Ae;Jang, Se-Bok
    • Journal of Microbiology and Biotechnology
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    • v.19 no.12
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    • pp.1557-1564
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    • 2009
  • Human CDX2 is known as a caudal-related homeodomain transcription factor that is expressed in the intestinal epithelium and is important in differentiation and maintenance of the intestinal epithelial cells. The caudal-related homeobox proteins bind DNA according to a helix-turn-helix structure, thereby increasing the structural stability of DNA. A cancer-tumor suppressor role for Cdx2 has been shown by a decrease in the level of the expression of Cdx2 in colorectal cancer, but the mechanism of transcriptional regulation has not been examined at the molecular level. We developed a large-scale system for expression of the recombinant, novel CDX2, in Escherichia coli. A highly purified and soluble CDX2 protein was obtained in E. coli strain BL21(DE3)RIL and a hexahistidine fusion system using Ni-NTA affinity column, anion exchange, and gel filtration chromatographies. The identity and secondary structure of the purified CDX2 protein were confirmed by MALDI-TOF MS, Western blot, and a circular dichroism analyses. In addition, we studied the DNA-binding activity of recombinant CDX2 by ELISA experiment and isolated human CDX2-binding proteins derived from rat cells by an immobilized GST-fusion method. Three CDX2-binding proteins were found in the gastric tissue, and those proteins were identified to the homeobox protein Hox-D8, LIM homeobox protein 6, and SMC1L1 protein.

Novel Modification of Growth Medium Enables Efficient E. coli Expression and Simple Purification of an Endotoxin-Free Recombinant Murine Hsp70 Protein

  • Zachova, Katerinat;Krupka, Michal;Chamrad, Ivo;Belakova, Jana;Horynova, Milada;Weigl, Evzen;Sebela, Marek;Raska, Milan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.7
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    • pp.727-733
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    • 2009
  • Heat shock protein 70 kDa (hsp70), a molecular chaperone involved in folding of nascent proteins, has been studied for its ability to activate innate and specific immunity. High purity hsp70 preparation is generally required for immunization experiments, because endotoxins and other immunologically active contaminants may affect immune responses independently of hsp70. We have developed a novel modification of E. coli-expression medium that enabled a simple two-step production and purification method for endotoxin-free recombinant hsp70. During Ni-NTA-based affinity purification of hsp70, a contaminating protein from host E. coli cells, L-glutamine-n-fructose-6-phosphate aminotransferase (GFAT), was identified. By testing various compounds, supplementation of growth medium with a GFAT metabolite,N-acetylglucosamine, was found to reduce GFAT expression and increase the total hsp70 yield five times. The new protocol is based on column purification of His-tagged hsp70 protein produced by E. coli with the modified medium, followed by endotoxin removal by Triton X-114 extraction. This approach yielded hsp70 with high purity and minimal endotoxin contamination, making the final product acceptable for immunization experiments. In summary, a simple modification of growth medium allowed production of recombinant mouse hsp70 in high yield and purity, thus compatible with immunological studies. This protocol may be useful for production of other Histagged proteins expressed in E. coli.

Plasma Lipidomics as a Tool for Diagnosis of Extrahepatic Cholangiocarcinoma in Biliary Strictures: a Pilot Study

  • Prachayakul, Varayu;Thearavathanasingha, Phataraphong;Thuwajit, Chanitra;Roytrakul, Sittiruk;Jaresitthikunchai, Janthima;Thuwajit, Peti
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.4155-4161
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    • 2016
  • Biliary obstruction is a common clinical manifestation of various conditions, including extrahepatic cholangiocarcinoma. However, a screening test for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction is not yet available. According to the rationale that the biliary system plays a major role in lipid metabolism, biliary obstruction may interfere with lipid profiles in the body. Therefore, plasma lipidomics may help indicate the presence or status of disease in biliary obstruction suspected extrahepatic cholangiocarcinoma. This study aimed to use plasma lipidomics for diagnosis of extrahepatic cholangiocarcinoma in patients with biliary obstruction. Plasma from healthy volunteers, patients with benign biliary obstruction extrahepatic cholangiocarcinoma, and other related cancers were used in this study. Plasma lipids were extracted and lipidomic analysis was performed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Lipid profiles from extrahepatic cholangiocarcinoma patients showed significant differences from both normal and benign biliary obstruction conditions, with no distinction between the latter two. Relative intensity of the selected lipid mass was able to successfully differentiate all extrahepatic cholangiocarcinoma samples from patient samples taken from healthy volunteers, patients with benign biliary obstruction, and patients with other related cancers. In conclusion, lipidomics is a non-invasive method with high sensitivity and specificity for identification of extrahepatic cholangiocarcinoma in patients with biliary obstruction.

Measurement of Energy Dependent Differential Neutron Capture Cross-section of Natural Sm by Using a Continuous Neutron Flux below (연속에너지 중성자에 대한 천연 Sm의 중성자 포획단면적 측정)

  • Yoon, Jungran
    • Journal of the Korean Society of Radiology
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    • v.10 no.5
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    • pp.337-341
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    • 2016
  • We measured the neutron capture cross-section of natural Sm(n,${\gamma}$) reaction in the energy regions from 0.003 to 10 eV. The 46-MeV electron linear accelerator of Research Reactor Institute, Kyoto University was used for generating a continuous neutron source. The neutron time-of-flight method was adopted for energy measurement. An assembly of BGO($Bi_4Ge_3O_{12}$) scintillators composed of 12 pieces of BGO crystals measured prompt gamma rays from Sm(n,${\gamma}$) reaction. The BGO assembly was located at a distance of $12.7{\pm}0.02m$ from the neutron source. In order to determine the neutron flux impinging on the Sm, the $^{10}B(n,{\alpha}{\gamma})^7Li$ standard cross-section were used. Natural Sm(n,${\gamma}$) reaction measurement result of the neutron capture cross-section was compared with the results of evaluation of the BROND-2.2 and the previous experimental data of J. C. Chou and V. N. Kononov.

Quantification of Pre-parturition Restlessness in Crated Sows Using Ultrasonic Measurement

  • Wang, J.S.;Huang, Y.S.;Wu, M.C.;Lai, Y.Y.;Chang, H.L.;Young, M.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.6
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    • pp.780-786
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    • 2005
  • This study presents a non-video, non-invasive, automatic, on-site monitoring system the system employs ultrasonic transducers to detect behavior in sows before, during and after parturition. An ultrasonic transmitting/receiving (T/R) circuit of 40 kHz was mounted above a conventional parturition bed. The T/R units use ultrasonic time-of-flight (TOF) ranging technology to measure the height of the confined sows at eight predetermined locations. From this data, three momentary postures of the sow are determined, characterized as standing-posture (SP), lateral-lying-posture (LLP) and sitting posture (STP). By examining the frequencies of position switch Stand-Up-Sequence (SUS) between standing-posture (SP), lateral-lying-posture (LLP) and sitting-posture (STP) rate can be determined for the duration of the sow' confinement. Three experimental pureblooded Landrace sows undergoing normal gestation were monitored for the duration of confinement. In agreement with common observation, the sows exhibited increased restlessness as parturition approached. Analysis of the data collected in our study showed a distinct peak in Stand-Up-Sequence (SUS, i.e. the transition from lying laterally to standing up ) and sitting-posture (STP) rate approximately 12 h prior to parturition, the observed peak being 5 to 10 times higher than observed on any other measurement day. It is concluded that the presented methodology is a robust, low-cost, lowlabor method for the continuous remote monitoring of sows and similar large animals for parturition and other behavior. It is suggested that the system could be applied to automatic prediction of sow parturition, with automatic notification of remote management personnel so human attendance at birth could reduce rates of sow and piglet mortality. The results of this study provide a good basis for enhancing automation and reducing costs in large-scale sow husbandry and have applications in the testing of various large mammals for the effects of medications, diets, genetic modifications and environmental factors.

Proteomic Analysis of Bovine Pregnancy-specific Serum Proteins by 2D Fluorescence Difference Gel Electrophoresis

  • Lee, Jae Eun;Lee, Jae Young;Kim, Hong Rye;Shin, Hyun Young;Lin, Tao;Jin, Dong Il
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.788-795
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    • 2015
  • Two dimensional-fluorescence difference gel electrophoresis (2D DIGE) is an emerging technique for comparative proteomics, which improves the reproducibility and reliability of differential protein expression analysis between samples. The purpose of this study was to investigate bovine pregnancy-specific proteins in the proteome between bovine pregnant and non-pregnant serum using DIGE technique. Serums of 2 pregnant Holstein dairy cattle at day 21 after artificial insemination and those of 2 non-pregnant were used in this study. The pre-electrophoretic labeling of pregnant and non-pregnant serum proteins were mixed with Cy3 and Cy5 fluorescent dyes, respectively, and an internal standard was labeled with Cy2. Labeled proteins with Cy2, Cy3, and Cy5 were separated together in a single gel, and then were detected by fluorescence image analyzer. The 2D DIGE method using fluorescence CyDye DIGE flour had higher sensitivity than conventional 2D gel electrophoresis, and showed reproducible results. Approximately 1,500 protein spots were detected by 2D DIGE. Several proteins showed a more than 1.5-fold up and down regulation between non-pregnant and pregnant serum proteins. The differentially expressed proteins were identified by MALDI-TOF mass spectrometer. A total 16 protein spots were detected to regulate differentially in the pregnant serum, among which 7 spots were up-regulated proteins such as conglutinin precursor, modified bovine fibrinogen and IgG1, and 6 spots were down-regulated proteins such as hemoglobin, complement component 3, bovine fibrinogen and IgG2a three spots were not identified. The identified proteins demonstrate that early pregnant bovine serum may have several pregnancy-specific proteins, and these could be a valuable information for the development of pregnancy-diagnostic markers in early pregnancy bovine serum.

Isolation and Quantitative Analysis of Cinnamtannin B-1 from Osmunda japonica Thunb (고비로부터 Cinnamtannin B-1의 분리 및 함량 분석)

  • Kim, Min Suk;Woo, Kyeong Wan;Lee, Ki Ho;Lee, Hyun Joo;Lee, Seon Yu;Kang, Byoung Man;Jeon, Byung Hun;Cho, Jung Hee;Cho, Hyun Woo
    • Korean Journal of Pharmacognosy
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    • v.47 no.3
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    • pp.232-236
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    • 2016
  • In traditional Korean medicine, Osmunda japonica Thunb has been used as hemostasis and antipyretic treatment. The main compound "cinnamtannin B-1" was obtained by column chromatographic separation, and its structure was determined by spectroscopic methods, including $^1H$, $^{13}C$ NMR, and IT-TOF-ESI MS. Ash, moisture and extract content and acidinsoluble ash were monitored as identification test to establish the analytical methods. The optimum reflux extraction condition was 100% methanol extracted 30 min for 2 times. A quantitative analysis using HPLC method exhibited that the main compound at 24.7 min and its content was 0.96% in methanol extraction.

Quantitative Analysis of Chemical Composition and In Vitro Anti-oxidant and Anti-inflammatory Properties of Asparagus oligoclonos (방울비짜루 지표성분의 함량분석과 항산화·항염증 활성)

  • Lee, Hyun Joo;Jeong, Da Eun;Gang, Ju Eun;Sim, Mi-Ok;Seong, Tae Kyoung;Woo, Kyeong Wan;An, Byeongkwan;Jung, Ho Kyung;Cho, Hyun Woo
    • Korean Journal of Pharmacognosy
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    • v.49 no.2
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    • pp.138-144
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    • 2018
  • Asparagus oligoclonos is one of the endemic halophytes used folk medicine in Korea. We isolated the main compound rutin from methanol extracts of A. oligoclonos based on nuclear magnetic resonance and TOF ESI-MS data. We have investigated the quantitative analysis method of main compound using HPLC and the results exhibit that rutin content of A.oligoclonos were 1.816%. To explore anti-oxidant from A. oligoclonos ethanol extracts (AOE), we investigated the antioxidant effects of AOE on $H_2O_2$-induced oxidative stress in RAW 264.7 cell. AOE were reduced $H_2O_2$-induced oxidative stress via enhancement of cell viability, and AOE significantly decreased ROS production depending on concentration. Next, to screen for anti-inflammatory activity of AOE, we investigated the inhibitory effects of AOE in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. AOE had no effect on cell viability at a concentration of $500{\mu}g/mL$. Nitric oxide (NO) production inhibited in a dose-dependent manner. These results suggest that AOE may be a useful antioxidant and anti-inflammatory agent.

Proteomic analysis of rice mutants susceptible to Magnaporthe oryzae

  • Ryu, Hak-Seung;Song, Min-Young;Kim, Chi-Yeol;Han, Muho;Lee, Sang-Kyu;Ryoo, Nayeon;Cho, Jung-Il;Hahn, Tae-Ryong;Jeon, Jong-Seong
    • Plant Biotechnology Reports
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    • v.3 no.2
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    • pp.167-174
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    • 2009
  • To identify genes involved in rice Pi5-mediated disease resistance to Magnaporthe oryzae, we compared the proteomes of the RIL260 rice strain carrying the Pi5 resistance gene with its susceptible mutants M5465 and M7023. Proteins were extracted from the leaf tissues of both RIL260 and the mutant lines at 0, 24, and 48 h after M. oryzae inoculation and separated by two-dimensional polyacrylamide gel electrophoresis (2-DE). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis identified eight proteins that were differently expressed between the resistant and susceptible plants (three down- and five up-regulated proteins in the mutants). The down-regulated proteins included a triosephosphate isomerase (spot no. 2210), a 2,3-bisphosphoglycerate-independent phosphoglycerate mutase (no. 3611), and an unknown protein (no. 4505). In addition, the five up-regulated proteins in the mutants were predicted to be a fructokinase I (no. 313), a glutathione S-transferase (no. 2310), an atpB of chloroplast ATP synthase (no. 3616), an aminopeptidase N (no. 3724), and an unknown protein (no. 308). These results suggest that proteomic analysis of rice susceptible mutants is a useful method for identifying novel proteins involved in resistance to the M. oryzae pathogen.