• Title/Summary/Keyword: pHi

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Cyanide Degradation by Two Recombinant Cyanide Hydratases (Recombinant Cyanide Hydratases에 의한 시안화물 분해)

  • Kwon, Sung-Hyun;Cho, Dae-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.6
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    • pp.1287-1291
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    • 2009
  • The genes of cyanide hydratase(CHT), a kind of nitrilases whichhydrolyze cyanide to formamide were extracted from N. crassa and A. nidulans, the two fungal strains. The recombinant forms of the CHT originated from N. crassa and A. nidulans were prepared with N-terminal hexahistidine purificationtags or no tags, and expressed in E. coli. The enzymes were purified using immobilized metal affinity chromatography. They were compared according to their pH activity profiles, and kinetic parameters. The N. crassa CHT has the wider pH range of activity above 50% and three-fold higher turnover rate (6.6 ${\times}$ $10^8$ $min^{-1}$) than the A. nidulans, meanwhile the CHT of A. nidulans has the higher $K_m$ value. Expression of CHT in both N. crassa and A. nidulans were induced by the presence of KCN, regardless of any presence of nitrogen sources. Max. 82% of KCN was degraded in 60 min for biological degradation tests.

Effect of Increased Intracellular pH by HMA on the Cytotoxicity of Combined Treatment of Hyperthermia and Chemotherapy (HMA의 세포내 산도증가가 온열과 항암화학 치료의 세포독성에 미치는 효과)

  • Hur, Won-Joo;Song, Chang-Won
    • Radiation Oncology Journal
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    • v.13 no.2
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    • pp.121-128
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    • 1995
  • Purpose: The enhanced cytotoxic effect of combined treatment of hyper-thermia and chemotherapy by increasing intracellular acidity with HMA was investigated. Materials and Methods: FSall tumor cells were injected on the hindlegs of female $C_3H$ mice. When the tumor volume reached about 200mm3, experiments were performed on the groups classified as follows: Group I :Control, Group II : Melphalan alone (2.5mg/kg, 5mg/kg, 10mg/kg, 15mg/kg), Group III : Heat alone $(42.5^{\cdot}C$ for 1 hour) Group IV : Melphalan + Heat $(42.5^{\cdot}C$ for 1 hour), Group V : HMA(10mg/kg) + Melphalan(5.0mg/kg) + Heat$(42.5^{\cdot}C$ for 1hour). Each group included 8-12 mice on each experiment HMA (3-amino-6-chloro-5-(1-homopiperidyl )-N-(diaminomethylene) -c-pyrazinecarboxamide), an analog of amiloride which increases intracellular pH(pHi) was dissolved in dimethyl sulfoxide (DMS) and injected into the tumor-bearing mice through the tail vein. 10mg/kg of HMA and each dose of melphalan were injected into peritoneum of the tumor-bearing mice 30 minutes before heating. Tumor growth delay was calculated when the tumor volme reached at $1500mm^3$ Excision assay was performed on each group and repeated 2-4 times. Results : Tumor growth delay of each experimental groups at $1500mm^3$ were 9, 10, 13 and 19 days respectively. In vivo-in vitro excision assay using FSall tumor cells, the cytotoxicity of each experimental groups was $1.2{\times}10^7,\;1{\times}10^7,\;6{\times}10^6,\;1.7{\times}10^6\;and\;1{\times}10^5$ clonogenic cells/gm respectively When HMA was added to the combined treatment of heat and .chemotherapy, the tumor growth was delayed more than combined treatment without HMA i.e., 6 days tumor growth delay at $1500mm^3$ of tumor volume. Conclusion: The combined effect of cytotoxicity by heat and chemotherapy can be much more enhanced by HMA.

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Immobilization and Characterization of Rifamycin B Oxidase in Cellulose Acetate Beads (셀룰로오스 아세테이트에 고정화된 리파마이신 B 산화효소의 특성)

  • Chung, Bong-Hyun;Chang, Ho-Nam;Han, Moon-Hi
    • Microbiology and Biotechnology Letters
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    • v.13 no.2
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    • pp.115-118
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    • 1985
  • Rifamycin B oxidase converts rifamycin B to rifamycin S using oxygen as cosubstrate. Humnicola spp. (ATCC 20620) was treated with acetone and the cell powder was immobilized with cellulose acetate. The properties of the immobilized enzyme was examined. The optimum pHs of the immobilized and the free enzymes were 7.2. The optimum temperature of the immobilized enzyme was at 50-55$^{\circ}C$, which was 5$^{\circ}C$ higher than that of the free enzyme. The activities of the immobilized enzyme appeared less sensistive with respect to the changes of temperature and pH as compared to those of the free enzyme. Twenty percent of the enzyme activity was recovered when the enzyme was immobilized in 3mm beads. The storage stability was good below 4$0^{\circ}C$, but the activity decreased very rapidly above 5$0^{\circ}C$. The physical strength of the beads was good and was suitable as packing material in a three-phase enzyme reactor.

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A Study on the Measurement of Thermal conductivity of Vertical Borehole heat Exchanger (수직형 지중열교환기 열전도도 측정기술에 관한 연구)

  • Kim, Ji-Young;Lee, Euy-Joon;Chang, Ki-Chang;Kang, Eun-Chul
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.39-44
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    • 2008
  • The heat exchange between the Borehole Heat Exchanger(BHE) and the surrounding ground depends directly on ground thermal conductivity k at the certain site. The k is thus a key parameter in designing BHE and coupled geothermal heat pump systems. Currently, although a thermal hydraulic response test(TRT) is mostly used in practice, the thermal hydraulic TRT needs additional power and is generally time-consuming. A new, simple wireless P/T probe for a hi-speed k determination was introduced in this paper. This technique using a wireless P/T probe is less time-consuming and requires no external source of energy for measurement and predicts local thermal properties by measuring soil temperatures along the depth. Measured temperature data along the depth was analyzed. In order to verify the new technique for the determination of ground thermal conductivity, ground thermal conductivity k that calculated from the measured temperature data using a wireless P/T probe was compared with one obtained from conventional hydraulic TRT. When comparing the average k of two methods, the relative error was approximately 10%. As a result, the electronic TRT can replace the conventional hydraulic TRT method after carrying out the additional research on a lot of sites.

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Effect of Fertilizer Levels on Maior Agronomic Characteristics and Seed Yield in Job′s Tears [Coix lachryma-iobi L. var. mayeur STAPF] (율무 시비량 차이에 따른 주요형질 및 수량변이)

  • Kwon, Byung-Sun;Lee, Jung-Il;Park, Hi-Jin
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.33 no.4
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    • pp.404-411
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    • 1988
  • This study was conducted to find out the optimum fertilizer level for two job's tear varieties. Heuksuk and Ewon from local cultivars at 18 compositions of fertilizer levels. Plant height was longest. number of tillers and leaves were increased. stem diameter was thickest, 100 grains weight. stem and grain yield were heaviest at the compositions of fertilizer amounts with N-P$_2$O$\sub$5/-K$_2$O were 18-9-9$\^$kg/ (3-2-2) per 10a. Plant height. number of tillers and leaves. stem diameter, 100 grains weight and stem yield showed significant difference between grain yield and showed positive correlation. Judging from the results reported above, in optimum fertilizer amounts for N-P$_2$O$\sub$5/-K$_2$O seemed to he 18-9-9$\^$kg/ (3-2-2) per 10a.

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Enhanced visualization of the root canal morphology using a chitosan-based endo-radiopaque solution

  • Shashirekha Govind;Amit Jena;Satabdi Pattanaik;Mahaprasad Anarasi ;Satyajit Mohapatra;Vinay Shivagange
    • Restorative Dentistry and Endodontics
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    • v.46 no.3
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    • pp.33.1-33.12
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    • 2021
  • Objectives: This study aimed to investigate the efficacy of ionic and non-ionic-based contrast media (in vitro study) and the combinatorial effect of chitosan-based endo-radiopaque solution (CERS) (in vivo study) for visualization of the root canal anatomy. Materials and Methods: In vitro study (120 teeth): The root canal of maxillary premolars and molars (in vitro group 1 and 2 respectively, n = 60 each) were analyzed using 4 different contrast media (subgroups: Omnipaque 350, Iopamidol, Xenetix 350, and Urografin 76; n = 15 each) in combination with 5.25% sodium hypochlorite (NaOCl). Based on the results of the in vitro study, in vivo study (80 teeth) was done to compare Xenetix 350 + 5.25% NaOCl with CERS (in vivo group 1 and 2 respectively, n = 40 each) on maxillary and mandibular premolars and molars. Two endodontists used radiovisiography to assess the depth of ingress and identify the aberrant root anatomy after access cavity preparation, and after initial cleaning and shaping of canals. Kruskal-Wallis test was used for in vitro comparison (p < 0.05), and Wilcoxon signed-rank test and Mann-Whitney U test for in vivo analysis (p < 0.01). Results: In vitro study, Xenetix 350 + 5.25% NaOCl facilitated a significant higher visualization (p < 0.05). For in vivo study, CERS had a statistically significant depth of ingress (p < 0.01), and was efficient in identifying the aberrant root canal anatomy of premolars and molars. Conclusions: CERS facilitates better visualization of the root canal anatomy of human premolars and molars.

Rheological Properties of Dough and Quality Characteristics of Bread Added with Pumpkin Powder (단호박 분말을 첨가한 반죽의 물성 및 빵의 품질특성)

  • Bae, Jong-Ho;Woo, Hi-Seob;Jung, In-Chang
    • Journal of the Korean Society of Food Culture
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    • v.21 no.3
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    • pp.311-318
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    • 2006
  • This study aims to investigate the quality characteristics of breads with the addition of sweet pumpkin powder. Farinogram showed that the absorption rate of the dough decreased, the development time and stability became shortened, and the degree of attenuation tended to be grown along with increasing the amount of pumpkin powder. From the amylogram, it was found that the gelatinization starting temperature and the maximum viscosity of pumpkin powder added dough seemed to be decreased as the amount of pumpkin powder was increased. Extensogram showed that there was a decrease in the degree of extension of the dough added with increasing the amount of pumpkin powder, while an increase in the degree of resistance and resistance/extensibility. The lightness (L value) and redness (a value) of bread was found to be decreased with increasing the amount of pumpkin powder, while the yellowness (b value) increased. In terms of the dough texture, for which the hardness, cohesiveness and gumminess of the dough were measured, there were no significant differences between groups, while the dough added with 8.0% pumpkin powder showed a significant decrease in the elasticity. The results of sensory evaluation showed that the highest score of color (p<0.05) and taste (p<0.05) were obtained from the bread added with 6.0% and 8.0% pumpkin powder, while the highest score of texture in control and 3.0% pumpkin bread. In addition, the highest score of flavor (p<0.05) and overall acceptance (p<0.05) were observed in bread added with 6.0% pumpkin powder. Upon the results of this study, it was assumed that the development of food products using pumpkin are prospective in response to health-oriented consumers.

Expression of full and fragment-B of diphtheria toxin genes in Escherichia coli for generating of recombinant diphtheria vaccines

  • Shaimaa Abulmagd;Abd El-Nasser A. Khattab;Hamdallah Zedan
    • Clinical and Experimental Vaccine Research
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    • v.11 no.1
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    • pp.12-29
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    • 2022
  • Purpose: In the present study, whole diphtheria toxin (dt) and fragment B (dtb) genes from Corynebacterium diphtheriae Park William were cloned into Escherichia coli, the purified expressed proteins were evaluated for ultimately using as a candidate vaccine. Materials and Methods: The dt and dtb genes were isolated from bacterial strain ATCC (American Type Culture Collection) no. 13812. Plasmid pET29a+ was extracted by DNA-spin TM plasmid purification kit where genes were inserted using BamHI and HindIII-HF. Cloned pET29a+dt and pET29a+dtb plasmids were transformed into E. coli BL21(DE3)PlysS as expression host. The identity of the sequences was validated by blasting the sequence (BLASTn) against all the reported nucleotide sequences in the NCBI (National Center for Biotechnology Information) GenBank. Production of proteins in high yield by different types and parameters of fermentation to determine optimal conditions. Lastly, the purified concentrated rdtx and rdtb were injected to BALB/c mice and antibody titers were detected. Results: The genetic transformation of E. coli DH5α and E. coli BL21 with the pET-29a(+) carrying the dt and dtb genes was confirmed by colony polymerase chain reaction assay and were positive to grow on Luria-Bertani/kanamycin medium. The open reading frame of dt and dtb sequences consisted of 1,600 bp and 1,000 bp, were found to be 100% identical to dt and dtb sequence of C. diphtheriae (accession number KX702999.1 and KX702993.1) respectively. The optimal condition for high cell density is fed-batch fermentation production to express the rdtx and rdtb at 280 and 240 Lf/mL, dissolved oxygen was about 24% and 22% and the dry cell weight of bacteria was 2.41 g/L and 2.18 g/L, respectively. Conclusion: This study concluded with success in preparing genetically modified two strains for the production of a diphtheria vaccine, and to reach ideal production conditions to achieve the highest productivity.

The Effects of Aromatherapy on Skin pH and Pruritis in Patients with Xerosis Cutis (피부건조증 환자에 대한 아로마오일 사용시 스킨 pH.소양증 변화)

  • Kim Eun-Jeong;Yoo Wang-Keun
    • Journal of Society of Preventive Korean Medicine
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    • v.8 no.2
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    • pp.55-63
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    • 2004
  • Objectives : This study was designed to identify the possibility of aroma oils as the complementary medical goods specially for the effects of aromatheraphy on xerosis cutis. Materials and Methods : The participants were 23 adult patients and all participants of this study use aroma oils which is known to effect on xerosis cutis. The subjects consist of voluntary patients with xerosis cutis in Seong-So Hospital in Andong Kyoungbuk, Korea. From April 1st to April 30th, 2004 for 4 weeks, the subjects massaged aroma oils on itching parts or the whole body. Aroma oils were Lavender, Losemary, Jasmine and blended drop by drop per 10ml jojoba oil which used a carrier oil. Skin pH was measured with a skin pH meter(Model : HI98110, Se-Chang instruments, made in Portuga. After 4weeks using aroma oils, the participants answered questions about the feeling of satisfaction with aroma oils. Results : Changes in the physiological indices. The mean deviation of skin pH was $5.58{\pm}0.47$ points before using aroma oils and $5.53{\pm}0.45$ points after 2 weeks, no statistical significance was found(p=0.221). MD was $5.36{\pm}0.41$ points after 4 weeks using aroma oils, which was statistically significant decrease of 0.22 points(p=0.001) Changes on the Pruritus Score Scale. A modified scale of the Pruritus Score Scale(Duo, 1987) was used to measure the severity, location, frequency, and the inconveniences of daily life due to prurius. The maximum scale of severity was 4 points, the full marks of location was 2 points, the full marks of frequency was 3 points, the full marks of inconveniences of daily life due to pruritus was 3 points. The scores ranged from 0 to 12, with 12 indicating the most severe pruritus. There was no statistical difference in severity and frequency score at 4 weeks later(severity p=0.097, frequency p=0.633). A statistically significant difference was found in the score of location and the inconveniences of daily life due to pruritus(each p=0.003). Conclusion : Generally speaking, the patient suffering from renal itch is the higher than normal in skin pH levels. that means to show alkaline condition of skin surface. In some case in this study, skin pH levels was rather lower than normal levels when measured actually patients suffering from renal itch by skin pH meter. But in this study post-test skin pH levels decreased, showing the contribution of aromathrapy to acidic condition of skin surface in suffering from renal itch. It seems to be some help to cure a pruritus and also have no ill effects on aroma oils.

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Convergence Factors Affecting Aggression of College Students in a City -Focusing on Life Stresses- (일개 도시 대학생의 공격성에 영향을 미치는 융합적 요인 -생활스트레스 중심으로-)

  • Ha, Tae Hi
    • Journal of Digital Convergence
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    • v.17 no.5
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    • pp.319-326
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    • 2019
  • This study was examined the influences of life stress on the aggression of college students. For this purpose 262 college students in Daegu completed the related study. Data were collected from September 5 to September 7, 2017. Collected data were analyzed using IBM SPSS 25.0. The major findings were as follow; 1) The life stress of the subject was the highest in study problem. 2) There were significant differences in aggression according to gender(t=4.43, p<.001) and major(F=13.66, p<.001). 3) The aggression was positively correlated with interpersonal problem(r=.49, p<.001), study problem(r=.34, p<.001), economic problem(r=.34, p<.001), future problem(r=.35, p<.001) and value problem(r=.31, p<.001). 4) The factors affecting to aggression were interpersonal problem, science and engineering, and study problem, and these factors accounted for 30% of aggression. Through this study, it was possible to grasp the degree of life stress and the influencing factors of aggression of college students. And the significance of this study is to suggest the direction of program for the management of aggression of college students.