• Journal of Environmental Health Sciences
• /
• v.31 no.4 s.85
• /
• pp.340-348
• /
• 2005

Laboratory scale experiments were conducted to compare the performance of two types of sequencing batch reactor(SBR) systems, anoxic-oxic-anoxic-oxic $((AO)_2)$ SBR and anoxic-oxic-anoxic $(A_2O)$ SBR on the biological nitrogen and phosphorus removal. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBRs. The break point in the pH and DO curves at the oxic period coincided with the end of nitrifying activity at about 1 h 30 min in oxic phase, and the change in pH appears to be related to nitrate concentration. The TOC removal efficiency in $A_2O$ SBR was higher than that in $(AO)_2$ SBR. The denitrification was completed at the influent period. The 2nd non-aeration and aeration periods were not necessary for the nitrogen and phosphorus removal because of the low influent TOC concentration in this study. The release and uptake of phosphorus in $AO_2$ SBR was much higher than that in $(AO)_2SBR.$ In order to uptake more phosphorus, the 1st aeration period in $A_2O$ SBR should be prolonged.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.1
• /
• pp.51-55
• /
• 2004

Sopungsungi-won has been used as a traditional medicine for diabetes and it has been proved to be a potential remedy for type 2 diabetes mellitus. We previously reported that water extract of Sopungsungi-won exhibits anti-diabetic effects both in vivo and in vitro experiments. In the present study, we have chosen to examined anti-apoptotic effect of Rheum undulatum, which is the main component of Sopungsungi-won, on pancreatic ${\beta}-cells$, HIT-T15, against hydrogen peroxide $(H_2O_2)$. oxidative stress. To investigate the anti-apoptotic effect of Rheum undulatum water extract (RUWE) against $H_2O_2-induced$ apoptosis in pancreatic ${\beta}-cell$ line of hamster, HIT-T15, MTT assay, DAPI staining, TUNEL assay, RT-PCR and caspase-3 enzyme assay were performed. The morphological analysis demonstrated that cells treated with $H_2O_2$ exhibited classical apoptotic features, while such changes was reduced in cells pre-treated with RUWE. In addition, RUWE pre-treated cells prior to $H_2O_2$ treatment induced increase of levels of bcl-2 expression and decrease of caspase-3 enzyme activity compared to cells treated with $H_2O_2$ only. These results provide the possibility of usage of RU in patients with progressively deteriorated diabetes.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.2
• /
• pp.224-237
• /
• 2015

We hypothesized that the extract from steam exploded Q. variabilis might be cytoprotective for tenofibroblasts cells during oxidative stress. In the present study, the extracts obtained from steam exploded (severity log Ro 4.68) Q. variabilis contained high quantities of phenolics and flavonoids contents. Also, the extracts appear to have, on these tenofibroblasts, a protective effect against oxidative stress. Tenofibroblasts cells incubated with the extracts and stressed with $H_2O_2$ showed an increase in cell viability by MTT assay. The extracts is found to inhibit $H_2O_2$-induced apoptosis in tenofibroblasts cells, as shown by Annexin V/PI double staining analysis. Western blot data showed that in the extracts/$H_2O_2$-treated cells, the extracts inhibited the $H_2O_2$-dependent phosphorylation of ERK and p38. From these results, it is suggested that the extracts showed the protective effect on $H_2O_2$-mediated oxidative stress. The main chemical compounds of the extract was identified as 1,8-cineole by GC-MS analysis. The anti-apoptosis activity is accordingly believed to be attributable to the 1,8-cineole.

• Korean Journal of Agricultural Science
• /
• v.49 no.1
• /
• pp.137-149
• /
• 2022

We investigated the effects of Cirsium japonicum var. maackii (CJM) against oxidative stress-induced C6 glial cells and cognitive impairment in mice. To evaluate the anti-oxidative effect of the extract and fractions from CJM, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reactive oxygen species (ROS), and nitric oxide (NO) assays were conducted in H₂O₂-treated C6 glial cells. Furthermore, we identified the protective mechanisms of CJM with a scopolamine-treated mice model. The results revealed that H₂O₂ decreased the cell viability in C6 glial cells, indicating that H₂O₂ induced oxidative stress in glial cells. However, CJM fractions significantly increased cell viability in H₂O₂-treated C6 glial cells, which suggested that CJM protected against oxidative stress. CJM extract and fractions also reduced ROS and NO production, which were increased by H₂O₂ in C6 glial cells. In particular, the EtOAc fraction from CJM (EACJM) effectively protected against oxidative stress by increasing the cell viability and decreasing ROS and NO. Therefore, we carried out further in vivo experiments with EACJM. Scopolamine caused increases of ROS, thiobarbituric acid reactive substances (TBARS), and NO production. However, EACJM effectively alleviated ROS, TBARS, and NO levels compared to scopolamine-injected mice. In addition, EACJM up-regulated protein expressions of superoxide dismutase and glutathione peroxidase, indicating that EACJM enhanced the antioxidative system. Our results demonstrated that CJM had protective effects against oxidative stress in glial cells and memory dysfunction in mice. Based on these results, we propose that CJM could be a potential AD preventive and therapeutic agent.

• Current Optics and Photonics
• /
• v.8 no.5
• /
• pp.441-455
• /
• 2024

This study objective was to evaluate the effects and mechanisms of low-level laser therapy in H₂O₂-induced cell death in mouse macrophage RAW264.7 cell. After irradiation with 630 and 850 nm wavelength diode lasers with an intensity of 10 mW/cm² in RAW264.7 cells treated with 0.7 Mm H₂O₂, the effects and mechanisms of the two wavelengths on cell death inhibition were evaluated using MTT assay, ROS staining, TUNEL assay, flow cytometry analysis, and Western blot analysis. As a result, 630 or 850 nm light-emitting diodes (LED) were irradiated for 10 or 40 minutes to increase cell viability with H₂O₂ by about 1.7- or 1.6-fold, respectively. In addition, irradiation with two LEDs showed significant ROS scavenging effects, and TUNEL-positive cells were significantly reduced by 45.7% (630 nm) and 37.8% (850 nm) compared to cells treated with H₂O₂ alone. The Bax/Bcl-2 ratio of cells irradiated with both LEDs was significantly lower than that of cells treated with H₂O₂ only, and the expression of procaspase-3 and cleaved PARP was also significantly expressed in the direction of suppressing cell death. In conclusion, ROS scavenging activity by both LEDs irradiation leads to the expression of cell death pathway proteins in the direction of inhibiting cell death.

• Journal of the Korean Magnetics Society
• /
• v.21 no.1
• /
• pp.10-14
• /
• 2011

We have measured the ferromagnetic resonance (FMR) signal in as deposited and $400^{\circ}C$ annealed CoFeB/MgO thin film to investigate the annealing effect on magnetic anisotropies and FMR linewidth (${\Delta}H_{PP}$). The uniaxial anisotropy field ($H_{K1}$) was only observed in the as deposited sample. Whereas, in the $400^{\circ}C$ annealed sample, the biaxial anisotropy field ($H_{K2}$) was additionally observed in accompany with uniaxial anisotropy field ($H_{K1}$). The appearance of biaxial anisotropy fields was originated from the crystalline growth of bcc CoFeB(001) from the MgO(001) interface and by the B diffusion during thermal annealing. Also, the ${\Delta}H_{PP}$ of $400^{\circ}C$ annealed sample was increased compared with that of as deposited sample, which was due to the broad distribution of the magnetization axis by the biaxial anisotropy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.442-442
• /
• 2008

Hydrogen was produced by water plasma excited in very high frequency inductively coupled tube reactor. Mass spectrometry was used to monitor gas phase species at various process conditions. Water dissociation rate depend on the process parameters such as ICP power, flow-rate and pressure. Water dissociation percent in ICP reactor decrease with increase of chamber pressure and $H_2O$ flow rate, while increase with increase of ICP power. In our experimental range, maximum water dissociation rate was 65.5% at the process conditions of 265 mTorr, 68 sccm, and 400 Watt. The effect of $CH_4$ addition to a water plasma on the hydrogen production has been studied in a VHF ICP reactor. With the addition of $CH_4$ gas, $H_2$ production increases to 12% until the $CH_4$ flow rate increases up to 15 sccm. But, with the flow rate of $CH_4$ more than 20 sccm, chamber wall was deposited with carbon film because of deficiency of oxygen in gas phase, hydrogen production rate decreased. The main roles of $CH_4$ gas are to reacts with O forming CO, CHO and $CO_2$ and releasing additional $H_2$ and furthermore to prevent reverse reaction for forming $H_2O$ from $H_2$ and $O_2$. But, $CH_4$ addition has negative effects such as cost increase and $CO_x$ emission, therefore process optimization is required.

• The Korean Journal of Mycology
• /
• v.24 no.3 s.78
• /
• pp.214-222
• /
• 1996

This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The optimum condition for the mycelial growth was $25{\sim}30^{\circ}C$ and pH $6.0{\sim}7.0$. The carbon sources such as D-glucose, D-mannose and Dextrose were favorable to mycelial growth. As nitrogen sources, peptone, cassamino acid and glutamic acid appeared to be favorable. The optimum C/N ratio was about 20:1, when 2% of glucose was provided as a carbon source. The better organic acids and vitamin among tested ones were gallic, silicic acids and biotin. The mineral nutrients of $KH_2PO_4,\;FeSO_4{\cdot}7H_2O,\; MgSO_4{\cdot}7H_2O,\;ZnSO_4{\cdot}7H_2O$ were effective and the optimum concentrations were 0.05, 0.001, 0.02 and 0.003%, respectively.

• Journal of Korean Society for Atmospheric Environment
• /
• v.29 no.5
• /
• pp.545-552
• /
• 2013

While attainment rates for $SO_2$ and CO approached 100%, those for $PM_{10}$, $NO_2$, and $O_3$ have been low during the past decade. The attainment rates for 24-h $PM_{10}$ and 8-h $O_3$ have been only 1~3% and 5~12%, respectively, since the standards were strengthened in 2007. Variations in the 99th percentiles of 24-h $PM_{10}$, 8-h $O_3$, and 24-h $NO_2$, which are used as criteria for determining exceedance of standards, were examined by region. Because the analysis was based on short-term high-concentrations, the effects of Asian dust were observed for $PM_{10}$. Accordingly, it is necessary to specify whether exceptional events such as Asian dust will be included or not in determining the exceedances of standards. While variations in $NO_2$ were not large, there was an increasing trend in $O_3$. In the Yeongnam region, the increasing rate of $O_3$ concentrations was small although the decreasing rate of $NO_2$ was the greatest. In the Gangwon region, $NO_2$ concentrations were almost unchanged, but $O_3$ concentrations experienced a significant increase. Regional management strategies targeting short-term high concentrations of criteria pollutants analogous to the Special Act for the greater Seoul area will aid in improving attainment rates.

• Journal of Preventive Medicine and Public Health
• /
• v.54 no.1
• /
• pp.31-36
• /
• 2021

Objectives: Non-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as "N95 alternatives." This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control. Methods: A heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted. Results: The particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH2O, 5.9 mmH2O, and 5.1 mmH2O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH2O during initial inhalation and 25 mmH2O during initial exhalation. Conclusions: The sterilization wrap's particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.