• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2542-2546
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• 2010

The objective of this paper was to investigate the effect of dextran gel on preparation of nano-liposomes loaded with ginkgolide. During preparation, Sephadex G75, G50 and G25 were added in the aqueous phase respectively. From the experiment, nano-liposomes prepared by dextran gels were found spherical and smooth. The result indicated that aperture of dextran gels were narrower, particle size of nano-liposomes was smaller (207.13 ~ 89.16 nm) and zeta potential was greater (-36.2 ~ -29.5 mV) in more negative. The study also revealed that differences of the entrapment efficiency and drug loading among the three types of nano-liposomes were not significant. In vitro drug release test demonstrated that nano-liposomes had a better controlled release. To conclude, by using dextran gel in the preparation of nano-liposome loaded with ginkgolide, the particle size could be effectively controlled and the drug stability could be improved.

• The Korean Journal of Zoology
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• v.17 no.2
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• pp.81-92
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• 1974

The blood proteins of pine moth, Dendrolimus spectabilis Butler of different developmental stages were investigated by disc electrophoresis in acrylamide gels. Blood protein concentration was also determined during the metamorphosis. Protein concentration increased gradually with the growth of larva, reaching a maximum in themature larva, and the increase of protein bands also was accompanied. As the larva transforms into the prepupa the number of protein bands as well as the protein concentration dropped. A total of 22 bands were identified throughout the stages. Histochemical staining of the acrylamide gels by the PAS method, Toluidine blut O, and Sudan black demonstrated that the carbohydrate, mucopolysaccharide, and lipid were associated with certain blood proteins.

• YAKHAK HOEJI
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• v.35 no.4
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• pp.319-325
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• 1991

Aluminum phosphate gel was synthesized by reacting aluminum sulfate as a soluble aluminum salt to tribasic sodium phosphate in this study. The optimal synthesis conditions based on the yield of product were investigated by applying Box-Wilson experimental design. It was found that optimal synthesis conditions were as follows: Reaction temperature; $61~71^{\circ}C$, concentration of two reactants; 12.27~13.83%, concentration ratio of two reactants; [AI$_{2}$(SO$_{4}$)$_{3}$]/[Na$_{3}$PO$_{4}$]= 0.5, reaction time; 10.9~12.1 minutes, drying temperature of product; $60~72^{\circ}C$. Aluminum phosphate gel prepared by the optimal synthesis conditions was suspended with four types of natural and synthetic gums at the concentration of 0.375~1.5wv%. Their Theological properties of aluminum phosphate gels were examined with Haake-Rotovisco RV 20 rotational viscometer. It showed that the higher concentration of suspending agents and lower temperature, the higher viscosity. Aluminum phosphate gel suspended by pectin and agar showed plastic flow with rheopexy, and their gels suspended by sodium alginate and sod. CMC showed plastic flow with thixotropy.

• The Korean Journal of Food And Nutrition
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• v.16 no.2
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• pp.105-110
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• 2003

The effect of varietal differences of rice starches by amylose content and gel consistency on the retrogradation behavior was studied. The gel consistency test, which is designed to detect differences in the texture of cooked rice of varieties that have a similar amylose content, had been turned out to be useful in this study. Both Suwon 232 and San Li Cun had higher amylose content, but were greatly different in gel consistency values. The results showed that setback viscosity of rice flour measured in a Brabender amylograph was significantly affected by amylose content as well as gel consistency. Increase in the rigidity modulus (E) of rice starch gels during storage determined by using Texture analyzer indicated that amylose content was an important factor in terms of hardness development The study of Avrami kinetics of retrogradation showed that time constant of rice starch gels was influenced by amylose content, but not by gel consistency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.754-760
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• 1996

Effects of washing and additives on the texture of squid surimi gel which has been known to hard to gelation due to high protease activities and many water solubles were studied by SDS-PAGE, compression test, jelly strength and transmission electron microscopy analysis (TEM). Myosin (205 kDa) heavy chain was the major protein in water soluble fractions. It was impossible to make a gel after washing of the minced squid meat. These results suggested that squid (Todarodes pacificus) minced meat does not need a washing for good jelly products. $3.0\%$ of bovine plasma protein (BPP) produced the hardest gel ($16\%$ harder than the control) among the additives including egg white (EW), potato extracts (PE) and transglutaminase-K (TG-K) by compression test (P>0.05). Microstructure of control, $2\%$ EW and $4\%$ TG-K treated gels showed a sponge-like structure with more vacant space. Gels containing $3\%$ BPP formed the most rigid and arranged networks. Those results indicates that poor gel-network formation Was due to the degradation of myofibrillar proteins by proteases contained in the minced meat, which result in non-interlinkage.

• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.99-107
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• 1998

The objective of this study was to develop effective oral formulations of rhEGF for gastric ulcer healing using polycarbophil. hydroxypropylcellulose(HPC) and sucralfate as its bioadhesive bases. Cytoprotective effects of rhEGF, cell proliferation and differentiation. on the ulcers induced by ethanol or acetic acid in rats were studied. rhEGF release from HPC formulation was much faster than that from polycarbophil formulation. HPC formulation combined with small amount of sucralfate showed much slower release of rhEGF than only HPC base only. rhEGF preparations with bioadhesive polymers showed better effects on the healing of gastric ulcers than EGF solution when administered orally. When rhEGF preparations were administered at once and the animals were under starvation, polycarbophil formulation showed better effect on gastric ulcers than HPC formulation. Otherwise, when rhEGF preparations were given more than three times and the rats were fed normally, HPC formulation showed good healing efficacy of ulcers compared to polycarbophil formulation. rhEGF showed dose-dependent effect on the healing of both chronic and acute ulcers.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.469-473
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• 1985

The typical force-distance curves by puncture test and Back Extrusion test of acorn flour gels were investigated. Kc' and Ks' were calculated to estimate the compression and shear components of a puncture force. In this study, compression effect played a major role. The more concentration of acorn flour gel and diameter of probe increased, the more compression force contributed to the puncture force. In the Back Extrusion test, the effect of increasing the sample size was to extend the length of the plateau without affecting the maximum force. However, as the concentration of acorn flour gel increased, maximum Extrusion force became larger.

• Journal of the Korean Home Economics Association
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• v.19 no.4
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• pp.33-39
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• 1981

This study was attempted to determine the pectin contents of various fruits(Cherry, strawberry, plum, peach, apricot, apple, crabapple) and to investigate the changes in the properties of pectin and pectin gel during crabapple ripening. Methoxyl content, molecular weight and intrinsic viscosity were measured in ripened and unripened crabapples. In order to determine the characteristics of pectin gel, percent sag was measured by exchange Ridgelimeter, hardness and textural characteristics of jellies were measured by a penetrometer and a texturometer. The experimental results are summarized as follows: 1. The pectin contents of various fruits were 1.16% for cherry, 3.17% fir strawberry, 4.29% for plum, 5.51% for apricot, and pectin contents of peaches and apples varies depends on varieties from 4.54% to 5.61% to 6.52, respectively. The pectin contents of unripened and ripened crabapple wee 9.21% and 9.84% respectively, indicating that pectin content increased with fruit maturity. 2. The methoxyl contents, which was 6.61%~6.95%, was very low and it increased significantly during fruit ripening. Further, a decrease in acetyl content, intrinsic viscosity, molecular weight occurred during the ripening of crabapples. 3. The percent sag of crabapple jellies increased with fruit maturity from 5.26% to 5.79%, and the corresponding jelly grade decreased in ripened crabapple. 4. The hardness of jellies determined by a penetrometer was 79.15 pp.U. for ripened crabapple jelly, 90.62 pp.U. for unripe ned crabapple jelly. 5. In the textural characteristics of gels measured by a texturometer, the gels made from unripened crabapple were shown to have the highest values in hardness, cohesiveness, adhesiveness and gumminess.

• Polymer(Korea)
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• v.35 no.1
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• pp.94-98
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• 2011

Poly(2-hydroxyethyl methacrylate), PHEMA, hybrid gels containing Pluronic and acrylic acid (AAc) were prepared as new biocompatible and stimuli-responsive hydrogels by photo-polymerization technique. The prepared hybrid gel showed reversible, temperature-responsive swelling behavior due to the presence of Pluronic component, which underwent sol-gel transition at an elevated temperature to cause gel shrinkage. The hydrogel also exhibited increased swelling degrees and pH-sensitivity due to the AAc component with ionizable carboxylic acid groups. The microporous gel morphology and its changes upon stimuli was observed by scanning electron microscopy.

• Korean Journal of Materials Research
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• v.13 no.4
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• pp.219-223
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• 2003

Zirconia gels dispersed with fine Au particles have been prepared by the sol-gel method. Starting solution with (OC$Zr_4$$H_{ 9}$)$_4$, $C_4$ $H_{9}$ OH, $H_2$O,$ HNO_3$, $HAuC1_4$ was used to prepare gels in several molar ratio. After hydrolysis, viscosity of solutions as 4∼5 cP and gelling time of sols were spent about 9 days. As the heat-treatment temperature was increased,$ ZrO_2$ had the phase transition from tetragonal to monoclinic at $750^{\circ}C$. Heat-treatments of the gel have performed at 500, 700, 750, 800, 1000 and $1100^{\circ}C$ for 3 hrs, respectively. We have investigated TG-DTA, X-ray diffraction patterns, SEM and EDS. The size of Au fine particles dispersed in the heat-treatmented gel was about 0.15∼0.23 $\mu\textrm{m}$ and the shape was most sphericity.