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Measurements of $T_1$-and $T_2$-relaxation Time Changes According to the Morphological Characteristics of Gold Nanoparticles (GNPs) (금 나노 입자의 형태적 특성에 따른 $T_1$, $T_2$ 이완 시간의 변화 측정)

  • Jang, M.Y.;Han, Y.H.;Mun, C.W.
    • Investigative Magnetic Resonance Imaging
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    • v.15 no.1
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    • pp.48-56
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    • 2011
  • Purpose : The aim of this study is to measure the typical MR variables such as $T_1$- and $T_2$-relaxation times according to morphological characteristics of gold nanopartides as a preliminary study to perform theragnosis using local heating by gold nanopartides. Materials and Methods : Two types of gold nanoparticles were used. Spheres were synthesized by various methods and stirring speed. Rods were synthesized by adding various concentrations of sphere nanopartides. Gold nanopartides were mixed with 2% agarose gel at 1:1 ratio and then signals were acquired using a 1.5T MRI. For the measurements of $T_1$-and $T_2$-relaxation times, TR and TE were varied, respectively. The results were acquired through $T_1$ and $T_2$ curves based on the intensities of MR image using self-developed software. And Statistical analysis was performed. Results : $T_1$ times were measured 1.86 sec and 2.08 sec for sphere and rod, respectively. On the other hands, $T_2$ times were measured 57 ms and 35.45 ms for sphere and rod. Conclusion : The changes of the MR variables according to the morphological characteristics of the gold nanopartides were confirmed. Optimal MR imaging conditions can be obtained by choosing proper TR and TE according to the type of nanoparticles.

Determination of Adequate Method for Protein Extraction from Rice Bran and the Substitution of Dried Skim Milk with Protein Concentrate from Rice Bran in Early Weaned Pigs

  • Phipek, W.;Nagasinha, C.;Vallisuth, S.;Nongyao, C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.9
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    • pp.1268-1273
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    • 2011
  • The present study was conducted to determine a feasible method of protein concentrate extraction from rice bran (RBPC) and its effect as a substitution for skim milk in early weaning pig diets. An investigation to extract protein concentrate from full fat rice bran was undertaken to determine the best ratio of water and rice bran, the amount of NaOH and a HCl solvent to use in a simple paddle-type mixer with modified spinning to produce RBPC. The results stated that the best ratio for water mixing in the RBPC extraction process was 1:5 with 20 g NaOH and 30 min in a paddle-type mixer at 300 rpm. A mix of 250 ml 0.2 N HCl was optimum for neutralization and protein precipitation. After the fluid was spun out with a washing machine, the sediment was left for 12-14 hours to complete the filtration. One kilogram of rice bran could produce an average of 324.5 gram RBPC and it contained 3.40% ash, 496.48 kcal of GE/100 gram, 1.94% crude fiber, 28.20% ether extract, 7.64% moisture and 16.66% crude protein, respectively. A total of 45 crossbred piglets, weaned at 3 weeks of age were allotted into control diet (A) and dietary treatments formulated with a four different rates of RBPC substitution for skim milk at a percentage of 25 (B), 50 (C), 77 (D) and 100 (E) respectively, in a randomized complete block (RCB) design. All piglets had free access to feed and water until 8 week of age when the experiment ended. Feed intake, average daily gain, growth rate and feed efficiency were not affected by dietary treatments. Blood test parameters after completion of the growth trial indicated normal health. Even though the mean of cell hemoglobin concentration was significantly different between treatments (p<0.05) it was still within the normal range. The cost difference for BW gain of 100% RBPC substituted for skim milk in the weaning diet was approximately 35% lower than that of the control and the relative cost of production was 96.67, 92.85, 70.75 and 64.48% lower for the replacement of 25, 50, 75 and 100% of skim milk respectively. These results implied that this technology is feasible for use by small scale farmers to improve their self-reliance.

Studies on the Microbial Glucose Isomerase Part 2. Culture Conditions of Streptomytes sp. K-14 in Producing Glucose Isomerase (미생물의 포도당 이성화효소에 관한 연구 (제2보) Streptomyces sp. K-14 균주의 배양특성에 하여)

  • Tai Wha Chung;Moon H. Han
    • Microbiology and Biotechnology Letters
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    • v.4 no.4
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    • pp.145-151
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    • 1976
  • Cultural characteristics of a strain of Streptomyces sp. K-14 (KFCC 35051) producing glucose isomerase were demonstrated. The glucose isomerase was produced when the strain was grown in the medium containing pure xylan or xylan.containing materials such as wheat bran or com cob. The optimum condition was attained in a culture medium composed of 3 % wheat bran or com cob, 2 % com steep liquor, 0.1% $MgSO_4$$7H_2O$ and 0.012 % $CoSO_4$$7H_2O$ for the production of the glucose isomera,e. The production of the enzyme reached to a maximum level when the strain was cultured for 40 hrs $30^{\circ}C$ and pH 7.0.

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Effect of Medium Components and Culture Methods on Prothallus Propagation of Pteridium aquilinum var. latiusculum (Desv.) Underw. ex Hell. (고사리 전엽체의 증식에 미치는 배지구성물질과 배양방법의 영향)

  • Shin, So-Lim;Lee, Moo-Yeul;Choi, Jae-Sun;Lee, Cheol-Hee
    • Korean Journal of Plant Resources
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    • v.22 no.4
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    • pp.337-342
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    • 2009
  • Present studies were conducted to evaluate the effects of medium strength(MS and Hyponex), carbon sources and their concentrations, agar concentrations, and inoculation amounts on prothallus propagation of Pterdium aquilinum var. latiusculum(Desv.) Underw. ex Hell in vitro. The optimum MS medium strength for prothallus propagation was 2MS concentration. Phosphate source was most effective for prothallus growth of P. aquilinum var. latisculum. The addition of 1% sucrose or glucose to MS medium promoted prothallus multiplication. Growth of prothallus was not affected by agar concentration. Propagation of homogenized prothallus was vigorous even in liquid medium. Chopped gametophytes(100 and 200 mg) were inoculated on 250 ml ${\Delta}$flask with 100 mL of 2MS concentration medium and suspension culture was done at 100 rpm for 22 days. After 20 days, prothallus multiplication slowed down, so 100 mg of chopped prothalli is recommended for initial inoculation, since initial amount of inoculum did not affect subsequent prothallus multiplication. Consequently after 20 days of suspension culture, prothallus should be subcultured or transplanted outside of growing vessels.

Effect of Angiotensin-I Converting Enzyme Inhibitory from Hydrolysate of Soybean Protein Isolate (분리대두단백질 가수분해물의 Angiotensin-I Converting Enzyme 저해효과)

  • Back, Su-Yeon;Do, Jeong-Ryong;Do, Gun-Pyo;Kim, Hyun-Ku
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.1
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    • pp.8-13
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    • 2010
  • The angiotensin converting enzyme (ACE) inhibition effect of soybean protein isolate hydrolysate was studied using protease. Soybean protein isolate was hydrolysed by seven enzymes (Alcalase 2.4 L, Flavourzyme 500 MG, GC 106, Multifect Neutral, Neutrase 0.8 L, Papain 30,000 and Protamex), enzyme concentrations (0, 0.5, 1.0 and 1.5%), at various hydrolysis times (0, 1, 2, 3, 4, 5 and 6 hr) and suspension concentrations (1, 5, 7, 10 and 15%). Absorbance at 280 nm, brix and ACE inhibitory activity of soybean protein isolate hydrolysates were investigated. Absorbance at 280 nm and brix of Alcalase 2.4 L treatment were higher than other enzyme treatments. The optimum condition of hydrolysis was Alcalase 2.4 L, 1% enzyme concentration, 5% suspension concentration for 4 hr. $IC_{50}$ value of ACE inhibitory activity of soybean protein isolate hydrolysate was $79.94 {\mu}g/mL$. These results suggest that soybean isolate protein hydrolysate from Alcalase 2.4 L may be of benefit for developing antihypertensive therapeutics.

A Numerical Study on an Optimum Design of a Hybrid Collector Coupled with the Principle of Cyclone, Baffle and Bag-Filter (싸이클론과 배플 및 백필터 원리를 결합한 하이브리드형 집진기의 최적화 설계를 위한 수치해석)

  • Hong, Sung-Gil;Jung, Yu-Jin;Lim, Ki-Hyuk;Yoo, Jeong-Kun;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.983-989
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    • 2013
  • The current research reviewed the design conditions that would maximize the efficiency of the hybrid collector that combines in one unit "cyclone-inertial impaction-bag filter". The computational analysis for the shape of cyclone entry predicts that a design that installs the guide vane at the entry of the tangential type cyclone brings a high-rpm and powerful vortex, very effective in promoting the deflection of coarse particles from the streamline at the cyclone. As the lower part of the cyclone is venturi-shaped, however, a strong flow downward of 4 to 5 m/sec persists through the lower part of the hopper, revealing the likely reentrainment of collected dust. And the removal of the venturi at the lower part of the cyclone would solve the problem of the reentrainment of collected dust. The acceleration of the flow velocity through the adjustment of the gap of the collision baffle would increase the effect of collision, but as the interference with the dust separation is expected, the original design should be kept for the baffle.

A Study on the Torque Characteristics Depending on the Elastic Body Materials of a Hexadecagon Shaped Ultrasonic Motor (탄성체 재질 변화에 따른 16각형 초음파모터의 토크 특성 연구)

  • Cheon, Seong-Kyu;Jeong, Seong-Su;Lee, Byung-Ha;Ha, Yong-Woo;Kim, Myong-Ho;Park, Tae-Gone
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.5
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    • pp.286-291
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    • 2014
  • In this study, novel ultrasonic rotary motor of hexadecagon shape stator was proposed. Stator of the hexadecagon ultrasonic motor was composed of an elastic ring and ceramics. The elastic ring had sixteen sides and sixteen angular points. Eight ceramics were attached on the outer surface of the eight sides of the ring. When rotor of cylindrical shaft was inserted inside of the ring stator, central lines of the sixteen sides of the stator hold the shaft by the slight pressures(frictions). This slight pressure was a preload of the motor and it could be controlled by radius and thickness of the ring. When two sinusoidal voltages which have 90 degree phase difference were applied to each four ceramics, elliptical displacements of inner surface of the ring were obtained. These elliptical displacements of the inner surface rotated the shaft rotor through the frictions. The proposed hexadecagon ultrasonic motor was designed and analyzed by using the finite element method (FEM), depending on materials of the elastic ring. Based on the FEM results, one model of motor which showed maximum displacement at contact points was chosen and fabricated. And characteristics of the motor were compared with simulated results. When the motor was fabricated with these results, EL20ET0.5CT0.5CW2 model showed 115[rpm] speed about input voltage of 60[Vrms] at 65.6[kHz]. And the maximum torque of 6[gfcm] was obtained. From these results, the hexadecagon shaped ultrasonic motor can be used to actuator for optical device which needs detailed position control. Also it can be used to medical and portable device by reducing size and weight.

Development of Drainage Pump for Rescue Sinking Ship (침수선박 구조를 위한 대용량 배수펌프 개발)

  • Kim, Kyeong-Soo;Jung, Kang-Hyun;Kim, Hae-Young;Kim, Nam-Hun;Cho, Je-Hyoung
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.3
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    • pp.248-254
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    • 2015
  • There has been no previous study on technology development of large capacity drainage pump for rescue sinking ship in the country. The agricultural drainage pump was widely used for rescue sinking ship but this pump has several problems such as efficiency, low displacement and malfunction in winter. Therefore, this paper proposes to solve the problems for swiftly rescue sinking ship and develops the drainage pump system that has $20m^3/min$ mass flow rate specification at suction head 8 m. The centrifugal pump type the most commonly used in the field of naval architecture and ocean engineering was selected and designed based on the requirement specification. The blade design of impeller was derived from the Stepanoff coefficient and requirement specification and used computational fluid dynamics to review the target mass flow rate according to the impeller RPM at design operating conditions. We also performed structure analysis of the impeller to find structurally vulnerable points for the pump in service and completed the theoretical design of drainage pump system.

Characterization of Endochitosanases-Producing Bacillus cereus P16

  • Jo, Yu-Young;Jo, Kyu-Jong;Jin, Yu-Lan;Jung, Woo-Jin;Kuk, Ju-Hee;Kim, Kil-Yong;Kim, Tae-Hwan;Park, Ro-Dong
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.960-968
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    • 2003
  • A bacterial isolate showing a strong endochitosanase activity was isolated from soil and then characterized. The isolate was identified and designated as Bacillus cereus P16, based on morphological and biochemical properties, assimilation tests, cellular fatty acids pattern, along with 16S rRNA gene sequence. The optimized medium for producing extracellular chitosanase in a batch culture contained 1% tryptone, 0.5% chitosan, and 1% NaCl (pH 7.0). Powder chitosan and tryptone served the best as carbon and nitrogen sources, respectively, for the chitosanase production. Chitosanase activity was the highest when culture was completed at $37^{\circ}C$ among various temperatures ($20-42^{\circ}C$) tested in a shaking incubator (200 rpm). The levels of chitosanase activity in the culture fluid were 2.0 U/ml and 3.8 U/ml, respectively, when incubated in a flask for 60 h and in a jar fermenter for 24 h. The culture supernatant showed a strong liquefying activity on the soluble chitosan. The viscosity of 1% chitosan solution, that was incubated with the culture supernatant, was rapidly decreased, suggesting the secretion of endochitosanolytic enzymes by P16. The culture fluid revealed six endo-type chitosanase isozymes, two major (38 and 45 kD), and four minor (54, 65, 82, and 96 kD) forms by staining profile. The crude enzymes were very stable, and full activity was maintained for 4 weeks at $4^{\circ}C\;or\;-20^{\circ}C$ in the culture supernatant, suggesting a highly desirable stability rate for making an industrial application of the crude enzymes. The supernatant also cleaved the insoluble chitosan powder, but the hydrolysis rate was much lower. The enzymic degradation products of chitosan contained $(GlcN)_n$ (n=2-8). The concentration of chitosan in the reaction mixture of the crude enzyme affected the chitooligosaccharides composition of the hydrolysis products. When the higher concentration of chitosan was used, the higher degree of polymerized chitooligosaccharides were produced. By comparison with other commercial chitosanase preparations, P16 was indeed found to be a valuable enzyme source for industrial production of chitooligosaccharides from chitosan.

Proliposomal Clenbuterol Patch for Transdermal Delivery (프로리포솜을 이용한 클렌부테롤의 경피흡수 제제화)

  • Lee, Young-Joo;Chung, Suk-Jae;Lee, Min-Hwa;Shim, Chang-Koo
    • Journal of Pharmaceutical Investigation
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    • v.27 no.4
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    • pp.303-311
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    • 1997
  • Proliposomal patch of clenbuterol, ${\beta}_2-agonist$ bronchodilator, was prepared and its feasibility as a novel transdermal drug delivery system was examined. Proliposomal granules containing clenbuterol was prepared by a standard method using sorbitol and lecithin with (Rx 2) or without cholesterol (Rx 1). The porous structure of sorbitol in the proliposomes was maintained allowing tree flowability of the granules. Following contact with water, the granules were converted probably to liposomes almost completely within several minutes. It indicates that proliposomes may be hydrated, when they are applied on the skin under occlusive condition in vivo, by the sweat to form liposomes. Clenbuterol release from Rx 1 and Rx 2 proliposomes to pH 7.4 isotonic phospate buffer (PBS) across cellulose membrane (mol. wt. cut-off of 12000-14000) was retarded significantly compared with that from the mixture of clenbuterol powder and blank proliposomes. Interestingly, proliposomes prepared with lecithin and cholesterol (i.e., Rx 2 proliposomes) showed much more retarded release of clenbuterol than proliposomes prepared only with lecithin (i.e.. Rx 1 proliposomes), indicating that clenbuterol release from proliposomes can be controlled by the addition of cholesterol to the proliposomes. Proliposomal patches were prepared using PVC film as an occlusive backing sheet, two sides adhesive tape (urethane, 1.45 mm thickness) as a reservoir for proliposome granules and Millipore MF-membrane (0.45 mm pore size) as a drug release-controlling membrane. Rx 1 or Rx 2 proliposomes containing 4.6 mg of clenbuterol were loaded into the reservoir of the patch. Clenbuterol release from the patches to pH 7.4 PBS was determined using USP paddle (50 rpm)-over-disc release method. Clenbuterol release from the proliposomal patches was much more retarded even than from a matrix type clenbuterol patch (Boehringer Ingelheim ltd). Being consistent with clenbuterol release from the proliposomal granules, the release from the patches was highly dependent on the presence of cholesterol in the proliposomes : Patches containing Rx 2 proliposomes showed several fold slower drug release than patches containing Rx 1 proliposomes. When the patch containing Rx 1 proliposomes was applied on to the back of a hair-removed rat, clenbuterol concentration in the rat blood was maintained during 6-72 hrs. Transdermal absorption of clenbuterol from the patch was accelerated when the patch was prehydrated with 50 ml of pH 7.4 PBS before topical application. Above results indicate that sustained transdermal delivery of clenbuterol is feasible using proliposomal patches if the cholesterol content and pore size of the release rate-controlling membrane of patches, for example, are appropriately controlled.

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