• Title/Summary/Keyword: biological stability

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Studies on Cellulolytic Enzymes Produced by Chaetomium globosum -Part . 1 ; Properties of Crude Cellulolytic Enzymes- (Chaetomium globosum 이 생성(生成)하는 Cellulose 분해효소(分解酵素)에 관(關)한 연구(硏究) -제1보(第1報) 조효소(粗酵素)의 성질(性質)-)

  • Chung, Dong-Hyo
    • Applied Biological Chemistry
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    • v.10
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    • pp.23-31
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    • 1968
  • We have obtained the following results, at the production of cellulase of Chaetomium globosum and its properties of crude enzyme. 1. At the production of enzyme, wheat bran solid culture was more active than surface or shaking culture. 2. The production of enzyme was maximum between the eighth and the tenth days, but slightly decreased thereafter. 3. The optimum condition of the reactions in saccharification with CMC were obtained the following results. 1) The optimum pH was within the range of from 4.0 to 5.0 and stable pH range was within 3.5 to 6.5. 2) The optimum temperature was $40^{\circ}C$ and thermal stability was below $50^{\circ}C$ and completely inactivated at $70^{\circ}C$ 4 Dialyzed crude enzyme was activated by $Mn^{++}\;Mg^{++}\;Fe^{++}\;and\;Mo^{++}\;respectively\;but\;Hg^{++}$ was inhibited its enzyme action.

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Thermodynamic Properties of Ubiquitin Folding Intermediate (Ubiquitin 폴딩 intermediate의 열역학적 특성)

  • Park, Soon-Ho
    • Applied Biological Chemistry
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    • v.47 no.1
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    • pp.33-40
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    • 2004
  • Thermodynamic properties of ubiquitin transient folding intermediate were studied by measuring folding kinetics in varying temperatures and denaturant concentrations. Through quantitative kinetic modeling, the equilibrium constant, hence folding free energy, between unfolded state and intermediate state in several different temperatures were calculated. Using these values, the thermodynamic parameters were estimated. The heat capacity change $({\Delta}C_p)$ upon formation of folding intermediate from unfolded state were estimated to be around 80% of the overall folding reaction, indicating that ubiquitin folding intermediate is highly compact. At room temperature, the changes of enthalpy and entropy upon formation of the intermediate state were observed to be positive. The positive enthalpy change suggests that the breaking up of the highly ordered solvent structure surrounding hydrophobic side-chain upon formation of intermediate state. This positive enthalpy was compensated for by the positive entropy change of whole system so that formation of transient intermediate has negative free energy.

Effect of Chlorine Treatment on the Rheological Properties of Soft Wheat Flour (박력분의 리올로지 특성에 대한 염소처리의 영향)

  • Han, Myung-Kyoo;Chang, Young-Sang;Shin, Hyo-Sun
    • Applied Biological Chemistry
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    • v.32 no.4
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    • pp.327-331
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    • 1989
  • In this study the Theological properties between C1-treated soft wheat flour and untreated soft wheat flour was determined. Chlorine treatment lowered pH of the flour in a linear fashion. Water absorption and dough stability was high in proportion to the increase of treatment level but mechanical tolerance index was reduced by each increment of chlorine. The valorimeter value did not exhibit reproducible trend on treatment of chlorine. In general, resistance(BU), resistance to extension and maximum viscosity(BU) were highest in control group; lowest in 1 oz./cwt. flour and tended to rise in 2 oz./cwt. flour when it fermented in chamber for 90 min and 135 min. The maximum viscosity was highest (1,160BU) in 4 oz./cwt. flour and temperature at maximum viscosity tended to rise gradually in proportion to the increase of treated level.

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Effect of the Modified Starch on the Physical Properties of Tomato Ketchup (토마토 케찹의 물리적 성질에 변성전분이 미치는 영향)

  • Lee, Young-In;Noh, Wan-Seob;Lee, Seung-Ju
    • Applied Biological Chemistry
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    • v.40 no.1
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    • pp.48-52
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    • 1997
  • Modified starches were used as additives to make tomato ketchup, and their effects on the rheological properties, serum separation and sensory characteristics of the tomato ketchup were examined. The magnitudes of the yield stress and the consistency index of the tomato ketchup with the additives, regarded as a Herschel-Bulkley fluid, were found to be in the order of ADA(acetylated distarch adipate)>SA(starch acetate) >HDP(hydroxypropyl distarch phosphate)>RCS(raw corn starch)>NS(no starch). The flow behavior indices of SA added ketchup and HDP added one were nearly constant regardless of the additive concentrations, whereas those of ADA and RCS increased with the additive concentration. In the serum separation test centrifugation, the ADA added ketchup showed the highest stability against separation, being fol-lowed by SA>HDP>RCS>NS. In the sensory evaluation, the magnitudes of the acceptance of the ketchup with the additives were as ADA(2%)>SA(2%)>RCS(2%)>NS>HDP(2%).

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The Comparison in the Physicochemical Properties of Sesame Seeds by Producing Areas (산지에 따른 참깨종자의 이화학적 특성 비교)

  • Lee, Min-Jung;Kim, Ki-Hong
    • Applied Biological Chemistry
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    • v.48 no.2
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    • pp.128-131
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    • 2005
  • Sesame seed is known as a good nutritional source containing high oil (51%) and protein (20%). Sesame oil contains a very high oxidative stability compared to other vegetable oils. To obtain basic information for quality evaluation, imported and domestic sesame seeds were investigated to measure general components (ash, protein, moisture and oil), fatty acid composition and lignan content. Although the protein contents were the highest in domestic sesame seeds, yet the lipid contents were the highest in imported sesame seeds. Unsaturated fatty acids such as oleic acid and linoleic acids were the highest in the domestic sesame seeds. Lignan contents, the most important component known as antioxidant, were significantly higher in domestic sesame seeds than other imported sesame seeds. These results suggest that domestic sesame seed may have the best quality in terms of the functional components.

Computer-aided design/computer-aided manufacturing of hydroxyapatite scaffolds for bone reconstruction in jawbone atrophy: a systematic review and case report

  • Garagiola, Umberto;Grigolato, Roberto;Soldo, Rossano;Bacchini, Marco;Bassi, Gianluca;Roncucci, Rachele;De Nardi, Sandro
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.38
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    • pp.2.1-2.9
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    • 2016
  • Background: We reviewed the biological and mechanical properties of porous hydroxyapatite (HA) compared to other synthetic materials. Computer-aided design/computer-aided manufacturing (CAD/CAM) was also evaluated to estimate its efficacy with clinical and radiological assessments. Method: A systematic search of the electronic literature database of the National Library of Medicine (PubMed-MEDLINE) was performed for articles published in English between January 1985 and September 2013. The inclusion criteria were (1) histological evaluation of the biocompatibility and osteoconductivity of porous HA in vivo and in vitro, (2) evaluation of the mechanical properties of HA in relation to its porosity, (3) comparison of the biological and mechanical properties between several biomaterials, and (4) clinical and radiological evaluation of the precision of CAD/CAM techniques. Results: HA had excellent osteoconductivity and biocompatibility in vitro and in vivo compared to other biomaterials. HA grafts are suitable for milling and finishing, depending on the design. In computed tomography, porous HA is a more resorbable and more osteoconductive material than dense HA; however, its strength decreases exponentially with an increase in porosity. Conclusions: Mechanical tests showed that HA scaffolds with pore diameters ranging from 400 to $1200{\mu}m$ had compressive moduli and strength within the range of the human craniofacial trabecular bone. In conclusion, using CAD/CAM techniques for preparing HA scaffolds may increase graft stability and reduce surgical operating time.

Assessment of Body Condition in Amphibians Using Radiography: Relationship between Bone Mineral Density and Food Resource Availability (방사선 촬영 기법을 이용한 양서류 신체상태 평가: 골밀도와 먹이 자원 가용성 간의 상관 관계)

  • Park, Jun Kyu;Do, Yuno
    • Korean Journal of Ecology and Environment
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    • v.52 no.4
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    • pp.358-365
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    • 2019
  • We measured the body composition, including bone mineral density (BMD) and food resource availability using dual energy X-ray absorptiometry and the carbon and nitrogen stable isotope ratios of body condition of 4 anuran species(Hyla japonica, Glandirana rugosa, Pelophylax nigromaculatus, Lithobates catesbeianus) in South Korea. Additionally, the carbon and nitrogen stable isotope ratios were employed to determine the food resource availability of anurans. We figured out the relationship between the body composition, including BMDs and food resource availability. The body composition and BMDs did not differ between male and female while there was difference among the species. Food resource availability and BMDs were the highest in L. catesbeianus, the lowest in H. japonica. BMDs tended to increase with higher food resource availability. Body composition and BMDs, which represent the body condition of an individual, can be used as an ecological indicator to assess the stability of the habitat of anurans.

Insights into evolution and speciation in the red alga Bostrychia: 15 years of research

  • Zuccarello, Giuseppe C.;West, John A.
    • ALGAE
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    • v.26 no.1
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    • pp.21-32
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    • 2011
  • Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

Fabrication of Micron-sized Organic Field Effect Transistors (마이크로미터 크기의 유기 전계 효과 트랜지스터 제작)

  • Park, Sung-Chan;Huh, Jung-Hwan;Kim, Gyu-Tae;Ha, Jeong-Sook
    • Journal of the Korean Vacuum Society
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    • v.20 no.1
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    • pp.63-69
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    • 2011
  • In this study, we report on the novel lithographic patterning method to fabricate organic thin film field effect transistors (OTFTs) based on photo and e-beam lithography with well-known silicon technology. The method is applied to fabricate pentacene-based organic field effect transistors. Owing to their solubility, sub-micron sized patterning of P3HT and PEDOT has been well established via micromolding in capillaries and inkjet printing techniques. Since the thermally deposited pentacene cannot be dissolved in solvents, other approach was done to fabricate pentacene FETs with a very short channel length (~30 nm), or in-plane orientation of pentacene molecules by using nanometer-scale periodic groove patterns as an alignment layer for high-performance pentacene devices. Here, we introduce $Al_2O_3$ film grown via atomic layer deposition method onto pentacene as a passivation layer. $Al_2O_3$ passivation layer on OTFTs has some advantages in preventing the penetration of water and oxygen and obtaining the long-term stability of electrical properties. AZ5214 and ma N-2402 were used as a photo and e-beam resist, respectively. A few micrometer sized lithography patterns were transferred by wet and dry etching processes. Finally, we fabricated micron sized pentacene FETs and measured their electrical characteristics.

A Study on the Development of Cosmeceutical Ingredient, Rhododendron mucronulatum, and the Application of Rheology Properties (진달래꽃(Rhododendron mucronulatum Turczaninow)을 이용한 화장품 소재 개발 및 물성에 관한 연구)

  • An, Bong-Jeun;Lee, Jin-Tae;Lee, Chang-Eon;Son, Jun-Ho;Lee, Jin-Young;Park, Tae-Soon
    • Applied Biological Chemistry
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    • v.48 no.3
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    • pp.273-279
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    • 2005
  • To develop cosmetics using Jindalae flowers (Rhododendron mucronulatum), the surface tensions of extracts were measured and the properties and stability of cream with extracts were investigated. The surface tension of 0.1% ethanol extract was 30.42 mN/m and that of distilled water was 72.2 mN/m. The surface tension of cream with 0.1% ethanol extract was similar to that of sample cream and the measured pH were weakly alkalic. The surface tension of 1% ethanol extract was the lowest value of 24.98 mN/m, the measured pH of cream with 1% ethanol extract was weakly acidic and the particle size of cream was stable. According to an oscillatory test, linear viscoelastic region was extended by adding of 1% water extract and 1% ethanol extract to cream, indicating that the cream had greater enhanced resistance for preserving inner structure as compared to outside stress. Besides, as a result of the diminished loss angle of ethanol extract cream, the elasticity of cream was increased more than that of sample cream and cream with 0.1% ethanol extract. In contrast, in the case of the increased loss angle of water extract cream, the viscosity of cream was increased. In conclusion, Rhododendron mucronulatum can be deliberated as a cosmetic material because 0.1% water and ethanol extracts showed efficacious physiological activities and cream with 1% extracts could extend linear viscoelastic region.