• Proceedings of the Korean Society of Applied Pharmacology
• /
• 2001.11a
• /
• pp.88-88
• /
• 2001

The effects of pH and temperature on the degradation of prokidn in various buffered aqueous solutions(pH 1.32~9.66) and temperatures (35, 45 and 6$0^{\circ}C$ were investigated. The effect of ionic strength on the degradation of prokidin was also measured by varying ionic strength (0.0466~1.5) at pH 1.35 and 45$^{\circ}C$ The effect of metal ions on the degradation of prokidin at pH 7.35 and 3.98 was observed. The degradation of prokidin followed the pseudo- first- order kinetics. The degradation rate of prokidin showed pH-dependent and temperature-dependent patterns. Prokidin was very stable at the pH below 3.95, where half-lives at 35, 45 and 6$0^{\circ}C$were 294, 206 and 107 day, respectively. However, it degraded very rapidly at pH above 6.49; the half-lives at 35, 45 and 6$0^{\circ}C$were 60, 25 and 13 day, respectively. As ionic strength increased, the degradation rate of prokidin increased. Some metal ions increased the degradation rate in the rank order of Mn > Fe > Cu >Fe On the other hand. other metal ions such as Bi, Ba. Zn, Ni, Co did not show unfavorable effect.

• Journal of the Korean Chemical Society
• /
• v.44 no.5
• /
• pp.429-434
• /
• 2000

The rate constants for the hydrolysis of styryldiphossphine oxide(SDPO) were deter-mined by ultraviolet visible spectrophotometric method and rate equation which can be applied over wide pH ranges was obtained. On the basis of pH-rate profile, hydrolysis product analysis, general base catalysis and substituent effect, a plausible hydrolysis mechanism is proposed : Below pH 4.5, the hydrolysis reaction is pro-ceeded by the attack of water to carbocation after protonaticentration of hydroxide ion.

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1979.10a
• /
• pp.243.3-244
• /
• 1979

Low molecular weight endo-glucanase fraction of cellulase from Trichoderma reesei was purified using Sephadex G-100 and concanavalin A-Sepha-rose 4B affinity chromatography. Its biochemical characteristics including pH profile, temperature profile and kinetic behavior were studied. The optimum conditions for enzymatic reaction were pH 6.0 and $5^{\circ}C.$ The activation energy for CMC (carboxymethylcellulose) was 10,800 cal/mole. Its adsorption to amorhous and crystalline cellulose was observed. Adsorption to amorphous cellulose was more rapid and greater than that of crystalline cellulose. Reconstitution study was performed. Significance of low molecular weight endo-glucanase on cellulose hydrolysis will be further discussed.

• Archives of Pharmacal Research
• /
• v.18 no.5
• /
• pp.314-319
• /
• 1995

Antacid granules were prepared by agglomeration and powder method in high speed agitation type granulator. The copmositions of the test antacids were sodium bicarbonate nad magnesium carbonate nad a coating material was powder of polyvinylacetal diethyl-aminocacetate (AEA) and an additive material was talc powder. The dissolution characteristics of base from the antacid granules were investigated to evaluate neutralization capacity of hydrochloric profile of base and neutralization behavior, the following results were obtained : The prepared granules showed a pH-dependent dissolution pattern of a base. The dissolution profile of a base was varied with addition of talc powder as well as coating amount of AEA. The relationship between the ratio of dissolution retarded time for 20% and 10% AEA. The relationship between the ratio of dissolution retarded time for 20% AEA coated granules $\theta_{20}/\theta_{10}$ and the diameter reduction of the granules was explained by the rate process of neutralization of hydrochloric acid.

• Journal of Pharmaceutical Investigation
• /
• v.26 no.4
• /
• pp.257-261
• /
• 1996

The seeds of Zizyphus Jujuba have been used as an antianxiety agent for the treatment of insomnia from the earliest times. Sanjoinine-A, isolated from the seeds of Zizyphus Jujuba, have been found to have a minor tranquilizer activity. However this drug is poorly soluble in water. In order to increase the dissolution rate of sanjoinine-A, solid dispersions with PVP-MC and inclusion complex with ${\beta}-cyclodextrin$ were prepared and evaluated. All of these systems increased the dissolution rate of sanjoinine A comparing with sanjoinine-A free base. From pH-rate profile of sanjoinine-A at $60^{\circ}C$, it was found that sanjoinine A was relatively stable in acidic solution, but unstable in basic solution.

• Journal of the Korean institute of surface engineering
• /
• v.35 no.6
• /
• pp.383-390
• /
• 2002

To investigate behaviors of Ti and O elements and microstructures of anodic titanium oxide films, the films were prepared by anodizing pure titanium in $H_2$S $O_4$, $H_3$P $O_4$, and $H_2O$$_2$ mixed solution at 180V. The microstructures and chemical states of the elements were analyzed using SEM, X-ray mapping, AFM, XRD, XPS (depth profile). The films formed on a titanium substrate showed porous layers which were composed of pore and wall, And with increasing anodizing time a hexagonal shape of cell structures were dominant and solace roughness increased. From the XRD result the structure of the Ti $O_2$ layer was anatase type of crystal on the whole. In the XPS spectra it was found that Ti and O were chemically binded in forms of Ti $O_2$, TiOH, $Ti_2$ $O_3$ at Ti 2p, and Ti $O_2$, $Ti_2$ $O_3$, $P_2$ $O_{5}$, S $O_4^{2-}$ at O ls respectively. Concentration of Ti $O_2$ decreased as the depth increased from the surface of the oxide film towards the substrate, but to the contrary concentrations of TiOH and $Ti_2$ $O_3$ increased.d.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.2
• /
• pp.211-218
• /
• 1993

The effect of active immunization against porcine somatostatin (SRIF-14) on somatostation and somatotropin secretion profile in 18 gilts was investigated. Gilts were assigned to the following treatments: control (sham injection, n = 6); bovine serum albumin (BSA) (injection of BSA with bacterial protein adjuvant, n = 6); SRIF (injection of BSA-SRIF-14 conjugate with bacterial protein adjuvant n = 6). Serum SRIF and pST were assayed from the blood samples taken on day 7 after the last immunization injection. Anti-SRIF antibody titres were assayed in weekly samples two weeks after the initial immunization to one week after the last immunization. Results revealed that the immunization protocol used in the present investigation failed to produce antibodies capable of neutralizing endogenous somatostatin. In addition, the porcine somatotropin assay revealed no significant differences in baseline pST concentration, mean peak amplitude and number of peaks during a 24 h secretory period among SRIF, BSA and control treatment. There were also no differences in SRIF baseline concentration, peak amplitude, and number of peaks during a 24 h secretory period among any of the three treatments. Circulating concentrations of pST and pSRIF were highly correlated (r = -0.09). Furthermore, anti-SRIF antibody titre was not detected in the serum of the gilts actively immunized against SRIF. These data, collectively, suggest that the protocol employed in the present investigation for active immunization against SRIF is not an effective method for changing SRIF and pST secretion profiles of the gilt and thus to enhance performance.

• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.3
• /
• pp.365-373
• /
• 2013

This study is performed to investigate the quality characteristics of sulgidduk added with cheonnyuncho fruit powder. Sulgidduk was prepared with freeze-dried cheonnyuncho, rice flour, sugar syrup and salt. The sulgidduk was made with various amounts (0, 3, 6, 9, 12%) of added cheonnyuncho fruit powder. The proximate composition, pH, Hunter's color value, texture profile analysis, sensory characteristics and SEM of cheonnyuncho sulgidduk were being examined. The addition of cheonnyuncho fruit powder has a tendency to decrease the moisture contents of sulgidduk while the crude ash, crude lipid and crude protein increased. The pH of sulgidduk decreased when the amounts of cheonnyuncho fruit powder increased. As the amount of cheonnyuncho fruit powder increased, the lightness (L) decreased, while the redness (a) and yellowness (b) increased. In texture profile analysis, the hardness decreased with increasing cheonnyuncho fruit powder contents, whereas cohesiveness, springiness, gumminess and brittleness increased. The results of sensory evaluation showed that the sulgidduk with 3%, 6% of cheonnyuncho fruit powder got the highest scores on the color, taste, springiness and acceptability. The air cells of sulgidduk observed by SEM were big and uniform with the amount of cheonnyuncho fruit powder increased. In conclusion, these results show that the quality and preference increased when 3%, 6% of cheonnyuncho fruit powder was added to the sulgidduk.

• Journal of the Mineralogical Society of Korea
• /
• v.10 no.2
• /
• pp.139-147
• /
• 1997

The Janghang smelter is the first lead, zinc and copper smelting facility in Korea which was operated for a half century from 1936 to 1989. The clay minerals and their heavy metal association in the soil profile around the smelter have been studied using XRD, EPMA, SEM-EDS, TEM, EPR and sequential extraction techniques. The soils in A horizon are highly acidic showing pH 4.45. The pH is going up with increasing depth. They have residual water contents of 1.18-1.51 wt%, loss on ignition of 6.32-7.79 wt%, and carbon contents of 0.08-0.88 wt%. Soils consist of quartz, feldspar, muscovite, kaolinite, vermiculite, biotite, chlorite, goethite and hematite in the decreasing abundance. The contents of clay minerals, especially vermiculite and chlorite, decrease with increasing depth. Sequential extraction experiments for the profile samples show that heavy metals (Zn, Cu, Pb, Cd) are highly concentrated in the A horizon of the soil profile as water-extractable (mostly amorphous), MgCl2-extractable (exchangeable in clay minerals), and organic phases. The heavy metal contents decrease with increasing depth. It suggests that the heavy metals are mainly associate with clay minerlas in an exchangeable state. It is also noted that heavy metals are highly concentrated in the manganese and iron oxide phases.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.7
• /
• pp.1403-1406
• /
• 2008