• Journal of Korean Society of Environmental Engineers
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• v.34 no.6
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• pp.406-413
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• 2012

Effect of three additives, chitosan, ferric chloride, and MPE50 on membrane fouling reduction was studied. They were introduced with various dosing rate into activated sludge, and changes in filtration resistance measured by the batch cell filtration test were evaluated. Both the filtration resistance and the specific cake resistance were minimized at 20 mg/g-MLSS with chitosan, 70 mg/g-MLSS with ferric chloride, and 20 mg/g-MLSS with MPE50 addition, respectively. Introduction of the additives into the activated sludge resulted in reduction of not only cake resistance, but also fouling resistance. However, the chitosan addition to three different activated sludge resulted in three different optimal dose of 10, 20, 30 mg/g-MLSS, respectively. This implies that the optimal dose is dependent on sludge characteristics rather than a constant value. Overdose above the optimal dosage always aggravated filterability in all cases. Zeta potential of sludge flocs, relative hydrophobicity, floc size distribution, soluble EPS concentration and supernatant turbidity were measured in order to analyze fouling reduction mechanism. Nearly neutral surface charge along with the largest particle size was observed at the optimal dose. This could be explained by particle destabilization and restabilization mechanism as positively charged additives were injected into sludge flocs of negative surface charge. Both soluble EPS concentration and supernatant turbidity also showed the lowest value at the optimal dose. These foulants are believed to be coagulated and entrapped in sludge flocs during flocculation. Chitosan and MPE50 which are cationic polymeric substances showed higher reduction in both soluble EPS and fine particles comparing with ferric chloride.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.960-964
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• 2007

This study was performed to examine the toxicity of Psoralea corylifolia L. by the single-dose oral toxicity tests in rat and bacterial reverse mutation assay. In single-dose oral toxicity tests, 5 mL ethanol extract of P. corylifolia L. were directly injected into 10 rats (5 males and 5 females) at a dosage of 2 g/kg. Death practice was not detected during breeding periods (14 days), and $LD_{50}$ was calculated over 2 g/kg. No difference were observed with control group in the growth rate and histological observations. In bacterial reverse mutation assay, his(-) Salmonella Typhimurium TA98, TA100, TA1535, TA1537 and trp(-) Escherichia coli WP2uvrA (pKM101) were used for assessing the toxicity of ethanol extracts of P. corylifolia L.. No significant difference in formation of the colonies and no dose-dependent increase was observed regardless of the addition of S9 mix. The results showed that ethanol extracts of P. corylifolia L. did not have single-dose oral toxicity and mutagenic toxicity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1166-1173
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• 2014

This study investigated the detoxification effects of enzymatic hydrolysate from oyster on acetaminophen-induced toxicity using HepG-2 cells. Oyster hydrolysate was made with 1% Protamex and 1% Neutrase after treatment with transglutaminase (TGPN) or without (PN). Two types of oyster hydrolysate were added to human-derived HepG-2 hepatocytes damaged by acetaminophen, after which the survival rate of HepG-2 cell was measured. In addition, glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities in the culture media were evaluated. The survival rates of HepG-2 cells were $136.2{\pm}1.4%$ at $100{\mu}g/mL$ of TGPN and $179.6{\pm}3.8%$ at $200{\mu}g/mL$ of TGPN. These cell survival rates were higher compared to that of the negative control group ($60.7{\pm}3.2%$) treated only with acetaminophen. GOT activity was $38.3{\pm}0.2$ Karmen/mL in the negative control group, whereas it was $19.9{\pm}0.5$ for TGPN ($200{\mu}g/mL$) and $22.0{\pm}2.4$ Karmen/mL for PN ($200{\mu}g/mL$). GOT and GTP activities were shown to be dependent on TGPN concentration, and significant reduction in activities could be conformed. The detoxification efficacy of TGPN was higher compared to that of PN. These results suggest that oyster hydrolysate has potential as a healthy food or pro-drug for liver protection.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.373-378
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• 2011

The striped fruit fly, Bactrocera scutellata, damages pumpkin and other cucurbitaceous plants. The developmental period of each stage was measured at seven constant temperatures (15, 18, 21, 24, 27, 30, and $33{\pm}1.0^{\circ}C$). The developmental time of eggs ranged from 4.2 days at $15^{\circ}C$ to 0.9 days at $33^{\circ}C$. The developmental period of larvae was 4.2 days at $15^{\circ}C$, and slowed in temperatures above $27^{\circ}C$. The developmental period of pupa was 21.5 days at $15^{\circ}C$ and 7.6 days at $33^{\circ}C$. The mortality of eggs was 17.1% at $15^{\circ}C$ and 22.9% at $33^{\circ}C$, Larval mortalities (1st, 2nd, 3rd) were 24.1, 27.3 and 18.2%, respectively, at $15^{\circ}C$, Pupal mortalities were 18.2% at $15^{\circ}C$ and 23.1% at $33^{\circ}C$. The relationship between developmental rate and temperature fit both a linear model and a nonlinear model. The lower threshold temperatures of eggs, larvae, and pupae were 12.5, 10.7, and $6.3^{\circ}C$, respectively, and threshold temperature of the total immature period was $8.5^{\circ}C$. The thermal constants required to complete the egg, larval, and pupal stages were 33.2, 118.3, and 181.2 DD, respectively. The distribution of each development stages was described by a 3-parameter Weibull function.

• Korean Journal of Agricultural Science
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• v.32 no.1
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• pp.71-80
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• 2005

Phytic acid chelates excellently the metallic ions and the positive ions, especially has high affinity with $Fe^{2+}$ and $Ca^{2+}$. Merits of phytic acid can be taked in easily, edibile and harmless to body, so it was investigated that phytic acid can be substituted for EDTA in this study. 1. The Intensificative effect of chelating agent and disinfective osmotic shock of Vibrio vulnificus The number of initial existent fungi measured $1.7{\times}10^6$. The percentages of the survival fungi against the osmotic shock by distillated water were calculated at 1 minute, 3 minute and 5 minute after inoculation. The percentages of the survival fungi in $Mg^{2+}$ were 92.5%, 91.8% and 79.8% at each time, the average percentage was 88%. Also the sudden extinction was observed around 1 minute after inoculation and the survival fungi were not observed from 3 through 5 minute in spite of repeated experimentation. 2. Influence of Vibrio vulnificus on the survival of the mice. The first mouse started to die in 180 minute after inoculation in case that the inoculating number was $2.3{\times}10^7cfu/ml$. All died within 4.5 hour. The average of survival time was 226 minute. The first mouse started to die in 228 minute after inoculation in case that the inoculating number was $0.8{\times}10^6cfu/ml$. All died within 5 hour. The average of survival time was 300 minute and the survival time was 1.3 times high. The tendencies of death in two cases were similar, but the fatal rate were largely dependent on inoculating number.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.182-206
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• 2003

Statement of problem : Successful osseointegration of endosseous threaded implants is dependent on many factors. These may include the surface characteristics and gross geometry of implants, the quality and quantity of bone where implants are placed, and the magnitude and direction of stress in functional occlusion. Therefore clinical quantitative measurement of primary stability at placement and functional state of implant may play a role in prediction of possible clinical symptoms and the renovation of implant geometry, types and surface characteristic according to each patients conditions. Ultimately, it may increase success rate of implants. Purpose : Many available non-invasive techniques used for the clinical measurement of implant stability and osseointegration include percussion, radiography, the $Periotest^{(R)}$, Dental Fine $Tester^{(R)}$ and so on. There is, however, relatively little research undertaken to standardize quantitative measurement of stability of implant and osseointegration due to the various clinical applications performed by each individual operator. Therefore, in order to develop non-invasive experimental method to measure stability of implant quantitatively, the resonance frequency analyzer to measure the natural frequency of specific substance was developed in the procedure of this study. Material & method : To test the stability of the resonance frequency analyzer developed in this study, following methods and materials were used : 1) In-vitro study: the implant was placed in both epoxy resin of which physical properties are similar to the bone stiffness of human and fresh cow rib bone specimen. Then the resonance frequency values of them were measured and analyzed. In an attempt to test the reliability of the data gathered with the resonance frequency analyzer, comparative analysis with the data from the Periotest was conducted. 2) In-vivo study: the implants were inserted into the tibiae of 10 New Zealand rabbits and the resonance frequency value of them with connected abutments at healing time are measured immediately after insertion and gauged every 4 weeks for 16 weeks. Results : Results from these studies were such as follows : The same length implants placed in Hot Melt showed the repetitive resonance frequency values. As the length of abutment increased, the resonance frequency value changed significantly (p<0.01). As the thickness of transducer increased in order of 0.5, 1.0 and 2.0 mm, the resonance frequency value significantly increased (p<0.05). The implants placed in PL-2 and epoxy resin with different exposure degree resulted in the increase of resonance frequency value as the exposure degree of implants and the length of abutment decreased. In comparative experiment based on physical properties, as the thickness of transducer increased, the resonance frequency value increased significantly(p<0.01). As the stiffness of substances where implants were placed increased, and the effective length of implants decreased, the resonance frequencies value increased significantly (p<0.05). In the experiment with cow rib bone specimen, the increase of the length of abutment resulted in significant difference between the results from resonance frequency analyzer and the $Periotest^{(R)}$. There was no difference with significant meaning in the comparison based on the direction of measurement between the resonance frequency value and the $Periotest^{(R)}$ value (p<0.05). In-vivo experiment resulted in repetitive patternes of resonance frequency. As the time elapsed, the resonance frequency value increased significantly with the exception of 4th and 8th week (p<0.05). Conclusion : The development of resonance frequency analyzer is an attempt to standardize the quantitative measurement of stability of implant and osseointegration and compensate for the reliability of data from other non-invasive measuring devices It is considered that further research is needed to improve the efficiency of clinical application of resonance frequency analyzer. In addition, further investigation is warranted on the standardized quantitative analysis of the stability of implant.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.293-303
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• 2007

Objective: Previously, we identified differentially expressed genes between GV and MII stage mouse oocytes using ACP technology. When we study one of GV selective genes, Obox family, we found Obox4 mRNA expression in ovaries that has been reported as expressed exclusively in testis. Therefore, this study was conducted for characterization and functional analysis for Obox4. Methods: Expression of Obox4 mRNA was examined in gonads and oocytes by RT-PCR. To determine the role of Obox4 in oocyte maturation, Obox4 dsRNA was microinjected into the cytoplasm of GV oocytes followed by 16 h of incubation in the plain medium or by 24 h of incubation in the medium containing IBMX. After RNAi, phenotypes and maturation rates were observed, change in mRNA expression was evaluated, and chromosomal status was confirmed by orcein staining. Results: Obox4 has minimal expression in the ovary compared to that of the other family members. When oocytes were cultured for 16 h in M16 medium after RNAi, maturation rate was not changed significantly, compared with that of non-injected or buffer-injected control oocytes. Surprisingly, however, when oocytes were cultured for 24 h in M16 containing IBMX, in which oocytes were supposed to arrest at GV stage, Obox4 RNAi oocytes were advanced to MI and MII. Spindle structure was disappeared and the chromosomes were condensed in the oocytes after Obox4 RNAi. Conclusions: This is the first report on the expression of Obox4 in the ovary and oocytes. Results of the study suggest that Obox4 plays a crucial role in spindle formation and chromosome segregation during meiosis in oocytes. In addition, Obox4 may play an important role in cAMP-dependent signal cascades of GV-arrest in mouse oocytes.

• Journal of Life Science
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• v.26 no.6
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• pp.663-672
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• 2016

The Cnidium monnieri (L.) Cusson is an annual plant distributed in China and Korea. The fruit of C. monnieri is used as a medicinal herb that is effective for the treatment of carbuncle and pain in female genitalia. However, the anti-cancer effects of CME have not yet been reported. In this study, we assessed the apoptotic effects and cell cycle arrest effects of ethanol extracts from C. monnieri on HCT116 colon cancer cells. The results of an MTT assay and LDH assay demonstrated a decrease in cell viability and the cytotoxic effects of CME. In addition, the number of apoptotic body and the apoptotic rate were increased in a dose-dependent manner through Hoechst 33342 staining and Annexin V-PI double staining. In addition, cell cycle arrest occurred at the G1 phase by CME. Protein kinase B (Akt) plays an important role in cancer cell survival, growth, and division. Akt down-regulates apoptosis-mediated proteins, such as mammalian target of rapamycin (mTOR), p53, and Glycogen Synthase kinase-3β (GSK-3β). CME could regulate the expression levels of p-Akt, p-mTOR, p-GSK-3β, Bcl-2 family members, caspase-3, and PARP. Furthermore, treatment with CME, LY294002 (PI3K/Akt inhibitor), BIO (GSK-3β inhibitor), and Rapamycin (mTOR inhibitor) showed that apoptotic effects occurred through the regulation of the AKT/mTOR/GSK-3β signaling pathway. Our results demonstrated CME could induce apoptosis and cell cycle arrest in HCT116 colon cancer cells.

• Journal of Life Science
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• v.17 no.11
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• pp.1576-1581
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• 2007

Dopamine reward pathway projecting from ventral tegmental area to nucleus accumbens is well known as playing an important role in alcohol dependence. It is supposed that this dopamine pathway is modulated by $5-HT_3$ nervous system, and it was reported that ondansetron (OND), $5-HT_3$ receptor antagonist, reduced drinking amount and increased abstinence rate in alcohol-dependent patients. The purpose of this study is to investigate the effect of combination of OND and naltrexone (NTX), non-specific opioid receptor antagonist, on alcohol intake in C57BL/6 mice. In 40 C57BL/6 mice in the state of alcohol dependence, vehicle, while OND 0.01 mg/kg, or NTX 1.0 mg/kg administrated respectively, or OND 0.01 mg/kg and NTX 1.0 mg/kg administrated simultaneously for ten days, medication effects on 2-hr alcohol, 22-hr water, 24-hr food intake and body weight were studied. When vehicle group was compared with 3 medication groups respectively, using a repeated measure ANOVA, NTX alone and vehicle groups showed a significant medication by time interaction (p=0.042) in 2-hr alcohol intake, but in the other 2 groups, OND and NTX combination group and OND alone group, there was no significant interaction with vehicle group in 2-hr alcohol intake. From these results, it is suggested that there is no effect on alcohol intake in mice treating with OND, and naltrexone#s suppression effect on alcohol intake in mice is attenuated when treating with OND and NTX simultaneously. It is supposed that a further study looking at the interactions of serotonin, dopamine and opioid nerves systems will be needed.

• Journal of Life Science
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• v.22 no.9
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• pp.1243-1253
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• 2012

The production and secretion of growth hormone (GH) in the anterior pituitary gland can be induced by several natural products to control cell proliferation, differentiation, and migration. To investigate whether Chungkookjang (CKJ) produced by the fermentation process affects GH-related metabolism, the secretion and the response of GH were observed in pituitary cells and GH target cells. Among six CKJs manufactured by different strains of glycine max, only three CKJs, including Daewon (DW), Daepung (DP), and Taegwang (TG), induced GH secretion from GH3 cells at 5.0 mg/ml concentration. There were no significant changes detected in the viability of any of the cells treated with these CKJs. In addition, the increase in GH secretion from the GH3 cells was dependent on the concentration of the three types of CKJs. The proliferation of cell lines, including MG63 and HepG2 cells, that originated from those derived from the GH target organs was significantly activated by treatment with the GH-containing conditional medium (GCM) harvested from the three CKJ-treated GH3 cells, although their induction rate was different from each other. In these cells, p-STAT5 was maximally translocated into the nucleus of MG63 cells 30 min after DW treatment, while it was translocated in HepG2 cells at 60 min. These results suggest that these three types of CKJ could enhance the secretion of GH, as well as the GCM-derived response, in the two target organs.