• Korean journal of food and cookery science
• /
• v.11 no.1
• /
• pp.26-32
• /
• 1995

This study was carried out to investigate the effect of protease on the functionality of soymilk protein. The protease from Bacillus polymyxa was selected because of the least production of bitter taste and calcium-aggregation. The results are summarized as follows: 1. Solubility of SMP(soymilk protein) and SPI(soyprotein isolate) were lowest at pH 4.7 and increased as the pH value reached closer to either ends. PT-SMP(pretense treated soymilk protein) showed higher solubility at all pH range, especially at pH 4.7 than SMP, SPI. 2. Emulsion activity of three samples was lowest at pH 4.7 and significantly increased as pH approched higher acidic or alkaline regions. PT-SMP showed similar activity to other samples, but less stability. 3. Foam capacity of PT-SMP was lowest at pH 8 and increased in acidic, alkaline pH. PT-SMP showed higher foam capacity at all pH range, but lower foam stability than SMP and SPI. 4. PT-SMP showed higher heat coagulability than other samples at all pH range except pH 4.7.

• Journal of Korean Neurosurgical Society
• /
• v.63 no.6
• /
• pp.707-716
• /
• 2020

Objective : The function of B7H3, a member of the B7 family of proteins, in neuroblastoma (NB) remains poorly characterized. Here we examine the expression pattern of B7H3 in clinical NB specimens and characterize the phenotype of B7H3 knock-down in NB cell line. Methods : Immunohistochemical (IHC) staining was carried out to assess the expression of B7H3 in clinical NB specimens. Survival association was analyzed using five Gene Expression Omnibus (GEO) datasets (GSE85047, GSE45480, GSE62564, GSE16476, GSE49710). Clonogenic survival and flow cytometry were performed after B7H3 knockdown to assess the cellular proliferation and cell survival in vitro. Impact of B7H3 silencing on NB growth was examined in vivo using the SH-SY5Y xenograft model. Results : On IHC staining, B7H3 was widely expressed in clinical NB specimens. Analysis of the transcriptional profiles of five GEO datasets clinically annotated NB specimens revealed that decreased B7H3 expression was associated with improved overall survival. B7H3 knockdown suppressed the proliferation of the SH-SY5Y NB model in vitro and in vivo. Cell cycle analysis revealed that B7H3 silencing induced G1/S arrest. This arrest was associated with the suppression of E2F1 expression and induction of Rb expression. Conclusion : Our results demonstrate that B7H3 expression correlate with clinical survival in NB patients. Preliminary studies suggest that B7H3 may mediate the G1/S transition.

• YAKHAK HOEJI
• /
• v.41 no.2
• /
• pp.181-186
• /
• 1997

A series of 7-deazahypoxanthine and 7-deazaadenine derivatives[6,7.8.9.10,13] as purine antagonists was prepared. The pyrrolidine-5-one derivatives[4,11] were treated vith $(C_2H_5)_3OBF_4$ to give 3- aryl-5-ethoxy-2H-3,4-dihydropyrrole[5,12], which were converted to 7-aryl-7,8-dihydro-7(9H)-deazahy-poxanthine[6,7,8,9,10] and 7-phenyl-2-methyl-7,8- dihydro-7(9H)-deazaadenine[13].

• Journal of Food Hygiene and Safety
• /
• v.12 no.3
• /
• pp.200-204
• /
• 1997

Effects of benzoate (0~0.6 g/$\ell$ ) and sorbate (0~2.0 g/$\ell$) on the growth of Escherichia coli O157:H7 in tryptic soy broth at various pH levels (4~8) and temperatures (4$^{\circ}C$, 37$^{\circ}C$) were investigated. Benzoate and sorbate were inhibited the growth of E. coli O157:H7 up to 12 hours cultivation at 4$^{\circ}C$, and 2.0 g/$\ell$ sorbate was only inhibited during 48 hours cultivation at 37$^{\circ}C$. Among the pH levels tested, pH 4 showed significant inhibitory effect against the E. coli O157:H7 on 4$^{\circ}C$ and at 37$^{\circ}C$, respectively. When used in combination 0.2 g/$\ell$ benzoate and sorbate were completely inhibited the growth of E. coli O157:H7 on pH 4 and at 37$^{\circ}C$. While on pH 5 at 4$^{\circ}C$, all of the concentration tested did not exert any inhibitory effect. The combined effects were retarded more than single treatment of E. coli O157:H7.

• Journal of Food Hygiene and Safety
• /
• v.13 no.4
• /
• pp.365-369
• /
• 1998

The in vitro effects of trisodium phosphate and cetylpyridinium chloride on E. coli 0157:H7 and L. monocytogenes were investigated. The trisodium phosphate and cetylpyridinium chloride was bactericidal toward E. coli 0157:H7 and L. monocytogenes. The killing effects of the $1{\times}10^{-2}\;M$ trisodium phosphate on E. coli 0157:H7 and L. monocytogenes were 30~40%, 40~50%, respectively. The killing effects of the $5{\times}10^{-7}\;M$ cetylpyridinium chloride on E. coli 0157:H7 and L. monocytogenes were 90~95%, 95~99%, respectively. The killing effects of the trisodium phosphate was $10^5$ times that of the cetylpyridinium chloride. Factors effecting the bactericidal action of trisodium phosphate and cetylpyridinium chloride were investigated and the action depended on temperature and pH.

• Food Science of Animal Resources
• /
• v.23 no.3
• /
• pp.278-283
• /
• 2003

Feasibility tests on using liposomes for detecting food-borne pathogenic bacteria were studied with E. coli 0157:H7 as a model analyte. lmmunoliposomes, whose surface was conjugated with anti-E. coli 0157:H7 IgG and which encapsulated the marker dye, sulforhodamine B, were used for the detection label. Among the feasibility tests, the first test was to use a test-strip on which antibodies to anti-E. coli O157:H7 IgG were immobilized. In this format, immunoliposomes that did not bind to E. coli O157:H7 in sample were captured and then exhibited a visible signal which was inversely related with the number of E. coli O157:H7 in sample. The second test was a direct liposome assay followed by immunomagnetic separation. In this format, immunoliposomes which were bound to E. coli O157:H7 were lysed with detergent and produced a signal which was proportionally related with the number of E. coli O157:H7 in sample. The results from both formats indicate that liposomes can be utilized as a detection label.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.4
• /
• pp.514-521
• /
• 2022

We report the effect of pH on the supramolecular complexation of two biothiols, viz., homocysteine (Hcy) and cysteine (Cys), with cucurbit[7]uril (CB[7]). Under basic pH conditions, Cys did not complex with CB[7], whereas Hcy efficiently complexed with CB[7], as confirmed by ¹H NMR spectroscopy and Ellman's reagent (5,5'-dithio-bis(2-nitrobenzoic acid), DTNB) assay. ¹H NMR and Raman spectroscopic studies revealed that, in the absence of CB[7], Hcy auto-oxidized slowly (~36 h) to homocystine (HSSH) under basic pH conditions. However, the rate of Hcy oxidation increased by up to 150 fold in the presence of CB[7], as suggested by the DTNB assay. Thus, supramolecular complexation under basic pH conditions led to the formation of a HSSH-CB[7] complex, and not Hcy-CB[7]. The results indicate that Hcy is rapidly oxidized to HSSH under the catalysis of CB[7], which acts as a reaction chamber, in basic pH conditions. Our studies suggest that Hcy concentration, a risk factor for cardiovascular disease, can be selectively and more easily quantified by supramolecular complexation with CB [7].

• Journal of Plant Biology
• /
• v.19 no.4
• /
• pp.95-99
• /
• 1976

This work deals with different extraction media and reaction mixtures on photosystem II activity of Spinach chloroplasts. The photoreduction rate of ferricyanide and DPIP by intact chloroplasts which extracted with four kinds of extraction media; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, was measured in five kinds of reaction mixtures; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, 0.05 M-Tris pH 7.2. The extraction medium which shows the highest photoreduction rate was S-Tris-N at pH 7.2 and S-Tricine-N at pH 8.0. As to the reaciton mixture, S-Tricine-N pH 8.0 showed the highest rate. On the complex effects of extraction media and reaction mixtures, the highest photordeuction rate of Hill oxidant by intact chloroplasts was obtained by S-Tris-N pH 7.2 extraction medium and S-Tricine-N pH 8.0 reaction mixture. The second highest activity was obtained by S-Tricine-N pH 8.0 extraction medium and reaction mixture.

• Journal of Environmental Science International
• /
• v.16 no.7
• /
• pp.779-784
• /
• 2007

Dinitrophenol is preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. The effect of pH on toxicity of dinitrophenol at high concentration was investigated, over a pH range of 5.7 to 8.7. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 7.0 to 7.8; at pH 6.0 degradation of 0.41 mM dinitrophenol was significantly inhibited; at pH <5.7, dinitrophenol degradation was completely inhibited after approximately 25% of the dinitrophenol was degraded. However no significant effect of pH variation was seen on glucose uptake by the activated sludge mixed culture.

• Korean Journal of Animal Reproduction
• /
• v.15 no.1
• /
• pp.7-13
• /
• 1991

This study was carried out to investigate the effects of pH of sperm-washing solution, sperm-washing frequency and individual bull on concentration of hydrogen ion in sperm-washed solution and sperm acrosome reaction. The results obtained were as follow. 1. When bovine sperm was washed at 4 times with SHP solution and incubated, the difference of light absorbance between sperm-washing and sperm-washed solution(${\Delta}$Ao-${\Delta}$At) was higher in 2nd sperm-washed solution than that in the other washed solutions. 2. When sperm was thrice washed with SHP solutions of pH 5.99, 6.38, 6.78, 7.10, 7.40, 7.69, 8.15, 8.45, and 8.83, ${\Delta}$Ao-${\Delta}$At was significantly increased at pH7.69 to 8.83, and ${\Delta}$Ao-${\Delta}$At in 1st sperm washed solution was significantly higher than that in 2nd and 3rd sperm washed solution. 3. When sperm of Holstein, KNC and Hereford was thrice washed with SHP solutions of pH 5.99, 6.38, 6.78, 7.10, 7.40, 7.69, 8.15, 8.45, and 8.83, Holstein showed higher ${\Delta}$Ao-${\Delta}$At of sperm Washed solution than KNC and Hereford, and ${\Delta}$Ao-${\Delta}$At in sperm washed solution was significantly increased at 7.69 for Holstein and at 8.15 for KNC and Hereford, respectively. 4. When sperm was thrice with SHP solution of pH 6.8, 7.1 and 7.4, and then incubated in mTALP of pH 7.4 for 15 minutes, in 1st and 2nd sperm washing ${\Delta}$Ao-${\Delta}$At of sperm washed solution was significantly higher at pH 7.1 and 7.4 than at pH 6.8, and the sperm acrosome reaction of pH 6.8, 7.1 and 7.4 was 49.1, 68.8 and 72.9%, respectively. The sperm acrosome reaction of pH 7.1 and 7.4 was higher than that of pH 6.8.