• Title/Summary/Keyword: modifiers

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Effects of Modifiers on the Supercritical $CO_{2}$ Extraction of Glycyrrhizin from Licorice and the Morphology of Licorice Tissue after Extraction

  • Kim Hyun Seok;Lee Sang Yun;Kim Byung Yong;Lee Eun Kyu;Ryu Jong Hoon;Lim Gio Bin
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.9 no.6
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    • pp.447-453
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    • 2004
  • Optimal conditions for the supercritical carbon dioxide $(scCO_{2})$ extraction of glycyr­rhizin from licorice (Glycyrrhiza glabra) were investigated, with an emphasis on the types and levels of modifiers. The morphology of the licorice tissue remaining after the $scCO_{2} $ extraction of glycyrrhizin was examined by scanning electron microscopy, coupled with measurements of ab­solute density. Conventional organic solvent extraction was also carried out for purpose of quantitative comparison. At 50 MPa and $60^{circ}C$ glycyrrhizin could not be extracted with pure $scCO_{2}$, while a considerable amount of glycyrrhizin was extracted when water was added to $scCO_{2}$ as a modifier. The highest recovery was found to be about $97\%$ when $70\%$ aqueous methanol was added to $scCO_{2}$ at a concentration of $15\%$. The optimal pressure and temperature for the supercritical fluid extraction of glycyrrhizin were observed to be 30 M Pa and $60^{circ}C$, respectively. Under these conditions, the percentage recovery of glycyrrhizin attained a maximum value of 102.67\pm$ $1.13\%$ within 60 min. Furthermore, in the case of $scCO_{2}$ modified with $70\%$ aqueous methanol, the licorice tissue obtained after extraction was found to be severely de­graded by excessive swelling, and the absolute density of the licorice residues was observed to be the highest.

Enhancement of Bt-Plus Toxicity by Unidentified Biological Response Modifiers Derived from the Bacterial Culture Broth of Xenornabdus nematiphila (Xenorhabuds nematophila 세균 배양액 유래 미확인 생리활성 물질의 비티플러스 살충력 상승효과)

  • Park, Youngjin;Kim, Minwoo;Kim, Kunwoo;Kim, Yonggyun
    • Korean journal of applied entomology
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    • v.54 no.2
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    • pp.55-62
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    • 2015
  • 'Bt-Plus' has been developed by mixing spores of Bacillus thuringiensis (Bt) and culture broth of Xenorhabdus nematophila (Xn). Despite its high toxicity, it has some imitation to broaden its efficacy against diverse insect pest spectrum. This study focuses on enhancement of Bt-Plus toxicity against semi-susceptible insect, Spodoptera exitgua, by addition of Xn metabolites. Two main Xn metabolites, oxindole (OI) and benzylideneacetone (BZA), are known to enhance the Bt insecticidal activities. The addition of OI or BZA significantly increased Bt-Plus pathogenicity. However, when the freeze-dried Xn culture broth was added to Bt-Plus, much less amount was enough to enhance the toxicity compared to the amount of OI or BZA. An HPLC analysis indicated that there were more than 12 unidentifed bacterial metabolites in Xn culture broth. These suggest that there are potent biological response modifiers in Xn metabolites other than OI and BZA.

Identification of Amino Acid Residues Involved in Xylanase Activity from Bacillus alcalophilus AX2000 by Chemical Modifiers (화학수식제에 의한 Bacillus alcalophilus AX2000 유래 Xylanase의 활성에 관여하는 아미노산 잔기의 확인)

  • Park Young-Seo
    • Microbiology and Biotechnology Letters
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    • v.34 no.2
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    • pp.121-128
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    • 2006
  • The purified xylanase from Bacillus alcalophilus AX2000 was modified with various chemical modifiers to determine amino acid residues in the active site of the enzyme. Treatment of the enzyme with group-specific reagents such as carbodiimide or N-bromosuccinimide resulted in complete loss of enzyme activity. These results suggested that these reagents reacted with glutamic acid or aspartic acid and tryptophan residues located at or near the active site. In each case, inactivation was performed by pseudo first-order kinetics. Inhibition of enzyme activity by carbodiimide and N-bromosuccinimide showed non-competitive and competitive inhibition type, respectively. Addition of xylan to the enzyme solution containing N-bromosuccinimide prevented the inactivation, indicating the presence of tryptophan at the substrate binding site. Analysis of kinetics for inactivation showed that the loss of enzyme activity was due to modification of two glutamic acid or aspartic acid residues and single tryptophan residue.

A Study on Reactive Extraction of Citric Acid in Citric-acetic-lactic Acid System (구연산-초산-유산계에서 구연산의 반응추출에 관한 연구)

  • Lee, Han-Seob;Kang, An-Soo
    • Applied Chemistry for Engineering
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    • v.5 no.1
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    • pp.90-98
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    • 1994
  • For elucidation of various parameters' effects on the reactive extraction of citric acids, citric-acetic-lactic acid system with various carriers, diluents, and modifiers were investigated. Carries used were secondary amines, tertiary amines, and solvation extract. Dileunts were n-butylacetate, methoisobutylketon(MIBK), kerosine, and xylene. Modifiers were TBP and isodecanol. The effects of temperature and pH in aquous phase were studied, and equilibrium constants for the reactive extraction were obtained. The re-extraction was performed by alkali solutions such as NaOH, $Na_2CO_3$, and $K_2HPO_4$. Based on the experiment Di-isotridecylamine(secondary amine ) gave higher degree of extraction and more selective than other extractants tested for the extraction of citric acid. N-butylacetate and TBP showed heigher performance for a diluent and modifier, repetitively. The degree of extraction was getting better with decreasing the pH in the aquous phase and the temperature of extraction system. The degree of re-extraction was getting higher with decreasing basicity in the stripping phase and the system temperature, and with increasing the concentration of alkali solution.

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Properties of Polymer Cement Mortar Based on Styrene-Butyl Acrylate according to Emulsifier and Monomer Ratios (유화제 및 단량체비에 따른 스티렌-부틸 아크릴레이트계 폴리머 시멘트 모르타르의 특성)

  • Jo, Youngkug;Hyung, Wongil
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.148-155
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    • 2013
  • The purpose of this study is to clarify the effect of the emulsifier ratio on the properties of the polymer cement mortars based on styrene-butyl acrylate (S/BA) latexes, and to obtain necessary basic data to develop appropriate latexes for cement modifiers. The polymer dispersions for cement modifiers was synthesized using styrene and butyl acrylate. Polymer cement mortars based on S/BA latexes were prepared with various monomer and emulsifier ratios, and their water-cement ratio, air content, flexural and compressive strengths, water absorption and chloride ion penetration were tested. From the test results, the maximum flexural and compressive strengths of polymer cement mortars based on S/BA latexes were obtained at a bound styrene content of 60% and an emulsifier ratio of 6%. Also, the water absorption and chloride ion penetration depth are greatly affected by the polymer-cement ratio rather than the bound styrene and emulsifier content. Accordingly, it is judged that S/BA latexes can be used place of the conventional polymer dispersions of cement modifier.

The design for therapeutic agents of Leucine Rich Repeat protein using bioinformatics

  • Kim, Seong Yeol;Park, Beom Seok
    • International Journal of Advanced Culture Technology
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    • v.7 no.4
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    • pp.156-162
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    • 2019
  • Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by progressive joint deterioration; Furthermore, RA can also affect body tissues, including the skin, eyes, lungs, heart and blood vessels. The early stages of RA can be difficult to diagnose because the signs and symptoms mimic those of many other diseases. It is not known exactly what triggers the onset of RA and how to cure the disease. But recent discoveries indicate that remission of symptoms is more likely when treatment begins early with strong medications known as disease-modifying anti-rheumatic drugs (DMARDs). Tumor necrosis factor (TNF) inhibitors are typical examples of biotherapies that have been developed for RA. The substances may occur naturally in the body or may be made in the laboratory. Other biological therapies care biological response modifiers (BRMs)such as monoclonal antibodies, interferon, interleukin-2 (IL-2) and a protein binder using repeat units. These substances play significant anti-inflammatory roles. Proteins with recurrent, conserved amino acid stretches mediate interactions among proteins for essential biological functions; for example, ankyrin (ANK), Heat repeat protein (HEAT), armadillo repeat protein (ARM) and tetratricopeptide repeats (TPR). Here, we describe Leucine rich repeats (LRR) that ideally fold together to form a solenoid protein domain and is more applicable to our current study than the previously mentioned examples. Although BRMs have limitations in terms of immunogenicity and effector functions, among other factors, in the context therapeutic use and for proteomics research, We has become clear that repeat-unit-derived binding proteins will increasingly be used in biotechnology and medicine.

Role of modifiers on the structural, mechanical, optical and radiation protection attributes of Eu3+ incorporated multi constituent glasses

  • Poojha, M.K. Komal;Marimuthu, K.;Teresa, P. Evangelin;Almousa, Nouf;Sayyed, M.I.
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3841-3848
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    • 2022
  • The effect of modifiers on the optical features and radiation defying ability of the Eu3+ ions doped multi constituent glasses was examined. XRD has established the amorphous nature of the specimen. The presence of various functional/fundamental groups in the present glasses was analyzed through FTIR spectra. The physical, structural and elastic traits of the glasses were explored. The variation in the structural compactness of the glass structure according to the incorporated modifier was enlightened to describe their suitability for a better shielding media. For the examined glasses, the metallization criterion value varied in the range 0.613-0.692, indicating the non-metallic character of the glasses with possible nonlinear optical applications. The computed elastic moduli expose the Li-containing glass (BTLi:Eu) to be tightly packed and rigid, which is a requirement for a better shielding channel. Furthermore, the optical bandgap and the Urbach energy values are calculated based on the optical absorption spectra. The evaluated bonding parameters revealed the nature of the fabricated glasses covalent. In addition, we investigated the radiation attenuation attributes of the prepared Eu3+ ions doped multi constituent glasses using Phy-X software. We determined the linear attenuation coefficient (LAC) and reported the influence of the five oxides Li2O3, CaO, BaO, SrO, and ZnO on the LAC values. The LAC varied between 0.433 and 0.549 cm-1 at 0.284 MeV. The 39B2O3-25TeO2-15Li2O3-10Na2O-10K2O-1Eu2O3 glass has a much smaller LAC than the other glasses.

Equations for Calculating Lateral-Torsional Buckling Capacity of H-Beam with Continuous Lateral Top-Flange Bracing (상부플랜지 연속 횡지지에 따른 초간편 H형강의 횡-비틀림 좌굴강도식 비교에 관한 연구)

  • Park, Jong-Sup;Lee, Son-Ho;Yoon, Ki-Young;Park, Jeong-Ung;Kim, Snag-Seup
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.437-440
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    • 2007
  • Design equations for calculating the lateral-torsional buckling moment resistances of I-section beams with continuous lateral top-flange bracing subjected to several loading conditions are investigated based on elastic finite-element analyses. The equations presented in this study are compared with current moment gradient modifiers presented by other researchers and specifications. The equation suggested in the SSRC Guides(1998) has a good agreement with the results of finite-element analyses. The moment gradient correction factors proposed in the SSRC Guides(1998) should be easily used to calculate the lateral-torsional buckling moment resistance of I-beams with continuous lateral top-flange bracing.

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Sequential Shape Modification for Monotone Convex Function: L2 Monotonization and Uniform Convexifiation

  • Lim, Jo-Han;Lee, Sung-Im
    • Communications for Statistical Applications and Methods
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    • v.15 no.5
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    • pp.675-685
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    • 2008
  • This paper studies two sequential procedures to estimate a monotone convex function using $L_2$ monotonization and uniform convexification; one, denoted by FMSC, monotonizes the data first and then, convexifis the monotone estimate; the other, denoted by FCSM, first convexifies the data and then monotonizes the convex estimate. We show that two shape modifiers are not commutable and so does FMSC and FCSM. We compare them numerically in uniform error(UE) and integrated mean squared error(IMSE). The results show that FMSC has smaller uniform error(UE) and integrated mean squared error(IMSE) than those of FCSC.

Implicit Adjuncts : The Cases of Degree Modifiers in Japanese and English

  • Ikeya, Akira;Ikawa, Hisako
    • Proceedings of the Korean Society for Language and Information Conference
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    • 2002.02a
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    • pp.92-102
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    • 2002
  • The issue of adjuncts has long been a neglected field of linguistic study whether it be syntactic or semantic. It is only in Pustejovsky (1995) that we find a brief mention of adjuncts. In addition to what the author calls true arguments, default arguments, and shadow arguments, he sets up a class of true adjuncts citing the following sentence, Mary drove down to new York on Tuesday. We will take up a small lexical item sugiru in Japanese, and we will argue that we should posit the notion of implicit adjuncts in describing the properties with the small Japanese lexical item sugiru. Throughout the discussions that follow we will demonstrate how the notion is independently motivated irrespective of what linguistic theory we are going to adopt.

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