• Journal of Periodontal and Implant Science
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• v.44 no.2
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• pp.57-64
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• 2014

Purpose: Both chronic periodontitis (CP) and iron deficiency anemia (IDA) induce oxidative stress in the body and cause an imbalance between reactive oxygen species and antioxidants, such as superoxide dismutase (SOD). This study explored the SOD enzyme activity of saliva and serum in CP patients with and without IDA and analyzed the impact of IDA on CP. Methods: A total of 82 patients were divided into four groups: control group (CG, 22), periodontally healthy IDA patients (IDA-PH, 20), CP patients (CP, 20), and IDA patients with CP (IDA-CP, 20). After clinical measurements and samplings, serum and salivary SOD levels were determined using an SOD assay kit. Results: IDA-CP patients exhibited a higher gingival index, bleeding on probing, probing pocket depth, and percentage (%) of sites with a clinical attachment loss (CAL) of ${\geq}6mm$ (P<0.008) than CP patients. The mean salivary and serum SOD levels were significantly lower in the IDA-PH, CP, and IDA-CP patients than in the CG group (P<0.008). A significant positive correlation between salivary and serum SOD activity was observed in IDA (P<0.05). Furthermore, serum and salivary SOD levels were significantly and negatively correlated with all periodontal parameters including the percentage of sites with CAL of 4-5 and ${\geq}6mm$ (P<0.05) except the significant correlation between salivary SOD activity and mean CAL and the percentage of sites with CAL of 4-5 mm (P>0.05) in these patients. Conclusions: Within the limits of this study, it may be suggested that IDA patients with chronic periodontitis have more periodontal breakdowns than patients with chronic periodontitis. Serum and salivary SOD activity levels were lower in the IDA-PH, CP and IDA-CP groups than in the CG. Iron deficiency anemia influenced the serum SOD activity but did not seem to affect the salivary SOD activity in these patients.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.170-174
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• 2005

Barley plants growing in the wet paddy field easily encounter suboptimal oxygen concentration in the rhizosphere that causes molecular oxygen deficiency in root cells. The capacity of root cells to utilize energy sources is known to be positively related to resistance to hypoxia stress. This study was conducted to investigate effects of hypoxia on enzymes involved in the starch and sucrose metabolism. Barley seedlings at the third leaf stage were subjected to hypoxia (1 ppm dissolved oxygen) by purging the culture solution with nitrogen gas for up to seven days. The protein content was slightly decreased by hypoxia for 7 days. $\alpha-Amylase$ activities increased significantly in the root but not in the shoot after 3 to 7 days of hypoxia. $\beta-Amylase$ activities were not affected significantly in both tissues. Additionally, sucrose synthase activities were affected little in both tissues by 7 days of hypoxia. The results indicate that root cells activate break­down of polysaccharide reserves in response to an acute hypoxia to supply energy sources for fermentative glycolysis and cell wall fortification.

• Journal of the Korean Institute of Gas
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• v.15 no.3
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• pp.26-30
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• 2011

Instantaneous water heater being not properly installed and not adequately maintained may produce fatal accidents due to carbon monoxide poisoning and suffocation. Insufficient supply of air into the gas appliance for complete burning of the fuel or blocking the outlet of the combustion gas could be a cause to increase carbon monoxide concentration in the exhaust gas of the gas appliance. In this work, the experiments are done with a collected instantaneous water heater using in domestic and the concentration of oxygen near the gas appliance and carbon monoxide in exhaust gas are observed to investigate the risk of instantaneous water heater. The concentration of oxygen near the gas appliance is reduced until 17.7% for the ratio of the ventilation area and floor area being 3.5%. If the outlet of combustion gas is blocked, the carbon monoxide concentration is steeply increasing more than 4,000ppm. Therefore, periodic checking the outlet of combustion gas is more important than vent area to reduce the risk of carbon monoxide poisoning.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.76-81
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• 1991

- The effect of redox potential (ORP) on lysine production by a leucine auxotrophic regulatory mutant of Corynebacterium glutclmicum on molasses medium was investigated in a 2-1 jar fermentor at pH 6.9 and $32^{\circ}C$. At a dilution rate of D=O.l $h ^1$, a maximum yield of Yr,,s=0.24 was obtained in either carbon- or leucine-limited chemostat where the redox potential was between -60 mV and - 100 mV. This level of redox potential corresponded to moderate oxygen deficiency. Under a high oxygen deficient condition of the redox potential of - 130 rnV (oxygen-limited chemostat), all the kinetic parameters such as $Y_[p/s}, q_s\; and \; q_p$ were decreased significantly and significant amounts of byproducts including glycine, alanine and valine were accumulated in the culture, indicating that the control of redox potential is important in lysine fermentation. At the redox potential of - 40 mV, on the other hand, large quantities of arginine (up to 0.38g/l) and glutamic acid (up to 0.12 g/l) were produced. A maximum lysine productivity of 2.41 g/l/h was achieved at - 66 mV under a carbon-limited condition.

• Clinical and Experimental Reproductive Medicine
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• v.41 no.3
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• pp.125-131
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• 2014

Objective: Under estrogen deficiency, blastocysts cannot initiate implantation and enter dormancy. Dormant blastocysts live longer in utero than normal blastocysts, and autophagy has been suggested as a mechanism underlying the sustained survival of dormant blastocysts during delayed implantation. Autophagy is a cellular degradation pathway and a central component of the integrated stress response. Reactive oxygen species (ROS) are produced within cells during normal metabolism, but their levels increase dramatically under stressful conditions. We investigated whether heightened autophagy in dormant blastocysts is associated with the increased oxidative stress under the unfavorable condition of delayed implantation. Methods: To visualize ROS production, day 8 (short-term dormancy) and day 20 (long-term dormancy) dormant blastocysts were loaded with $1-{\mu}M$ 5-(and-6)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-$H_2DCFDA$). To block autophagic activation, 3-methyladenine (3-MA) and wortmannin were used in vivo and in vitro, respectively. Results: We observed that ROS production was not significantly affected by the status of dormancy; in other words, both dormant and activated blastocysts showed high levels of ROS. However, ROS production was higher in the dormant blastocysts of the long-term dormancy group than in those of the short-term group. The addition of wortmannin to dormant blastocysts in vitro and 3-MA injection in vivo significantly increased ROS production in the short-term dormant blastocysts. In the long-term dormant blastocysts, ROS levels were not significantly affected by the treatment of the autophagy inhibitor. Conclusion: During delayed implantation, heightened autophagy in dormant blastocysts may be operative as a potential mechanism to reduce oxidative stress. Further, ROS may be one of the potential causes of compromised developmental competence of long-term dormant blastocysts after implantation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.284-288
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• 2004

The response of dissolved oxygen (DO) concentrations caused significant change in root number, root length, coleoptile length, shoot length and leaf age of seedlings. The genotypic difference in the effect of DO also highly significant (P<0.01) for all of the seedling traits. The number and length of root were extremely inhibited at the condition of $0.39\pm0.09$ DO concentration. While the coleoptile elongated markedly in the lowest DO concentrations, the shoot did not develop. The root growth was improved slightly at the $1.39\pm0.27mg L^{-1}$, however, there were no difference among genotypes at these two low DO concentrations. As the DO concentration become higher, the growth of root and shoot was improved remarkably. Root number, root length and shoot length was significantly different between $20\;and\;30^{\circ}C$ in DO rich and normal conditions, the development of those traits were apparently accelerated in high water temperature, however those traits of seedlings in DO deficiency were not different between the two temperatures except for shoot length. On the other hand the coleoptile length was not affected by the stagnant water temperature; it was stimulated by the low DO concentration. The competition of DO was greater as the seedling density was increased in the stagnant water, therefore the seedlings grown under high density have long and white coleoptiles, and the growth of roots and shoots was retarded severely.

• International Journal of Oral Biology
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• v.41 no.1
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• pp.17-23
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• 2016

Chronic/cyclic neutropenia, leukocyte adhesion deficiency syndrome, Papillon-$Lef{\grave{e}}vre$ syndrome, and $Ch{\grave{e}}diak$-Higashi syndrome are associated with severe periodontitis, suggesting the importance of neutrophils in the maintenance of periodontal health. Various Toll-like receptor (TLR) ligands are known to stimulate neutrophil function, including FcR-mediated phagocytosis. In the present study, the effect of TLR2 activation on the non-opsonic phagocytosis of oral bacteria and concomitant production of reactive oxygen species (ROS) by human neutrophils was evaluated. Neutrophils isolated from peripheral blood were incubated with Streptococcus sanguinis or Porphyromonas gingivalis in the presence of various concentrations of $Pam_3CSK_4$, a synthetic TLR2 ligand, and analyzed for phagocytosis and ROS production by flow cytometry and chemiluminescence, respectively. $Pam_3CSK_4$ significantly increased the phagocytosis of both bacterial species in a dose-dependent manner. However, the enhancing effect was greater for S. sanguinis than for P. gingivalis. $Pam_3CSK_4$ alone induced ROS production in neutrophils and also increased concomitant ROS production induced by bacteria. Interestingly, incubation with P. gingivalis and $Pam_3CSK_4$ decreased the amounts of ROS, as compared to $Pam_3CSK_4$ alone, indicating the possibility that P. gingivalis survives within neutrophils. However, neutrophils efficiently killed phagocytosed bacteria of both species despite the absence of $Pam_3CSK_4$. Although P. gingivalis is poorly phagocytosed even by the TLR2-activated neutrophils, TLR2 activation of neutrophils may help to reduce the colonization of P. gingivalis by efficiently eliminating S. sanguinis, an early colonizer, in subgingival biofilm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.200-214
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• 1994

In order to clarify the benthic environmental properties as a part of a study on the macrobenthic community in the Chinhae Bay System, water temperature, salinity and dissolved oxygen (DO) in surface and bottom water layers, mean grain size (${\phi}$) and sediment organic carborn (SOC) in surface sediment were analyzed at twelve stations during the period from June 1987 to May 1990. A high sediment organic carbon and hypoxic condition in bottom water due to the development of summer stratification and fine sediment texture toward the inner bay were important environmental characteristics of Chinhae Bay. Hypoxic conditions began to develop in the inner bay from May, and gradually spread toward the outer bay in summer with a peak in September when half the bay was affected by this oxygen deficiency. Recovery from this hypoxic condition in the bottom layer was observed from the beginning of autumn together with a disappearance of the summer stratification. Principal component analyses were carried out from the following five environmental variables:mean water temperature, salinity, dissolved oxygen in the bottom layer and mean grain size, sediment organic carbon in surface sediment. The twelve stations were classified into four areal groups based on the analyses. The division of the areal groups had high correlations to the sediment organic carbon content.

• Journal of Aquaculture
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• v.10 no.4
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• pp.457-462
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• 1997

During the period of the Cochlodinium polykrikoides red tide occurrence in the southern coast of Korea in 1997, we obseved the vertical migration of red tide organisms in situ, along with environmental factors such as water temperature, dissolved oxygen, pH, chlorophyll $\alpha$ and nutrients for practical application of loess suspension techniques ot diminish fisheries damage. To cope with serious outbreaks of red tide of C. polykrikoides, the finfish culturists resorted with loess suspension to disperse the bloom watermass by turning around it with fishing boats in full speed. Peak in afternoon the cell numbers were diminished in the surface layer after sunset red tide organisms settled down in the middle and bottom layer progressively again after sunrise. Chlorophyll $\alpha$ and dissolved oxygen showed the same trends of variation with the cell number. In the course of controlling the red tide with loess suspension we could not find any severs oxygen deficiency to kill the culture species.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.59-75
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• 2016

Reduced or black $TiO_{2-x}$ materials with oxygen-deficiency have been achieved by creating oxygen vacancies and/or defects at the surface using different methods. Fascinatingly, they exhibited an extended absorption in VIS and IR instead of only UV light with bandgap decrease from 3.2 (anatase) to ~1 eV. However, despite the dramatic enhancement of optical absorption in black $TiO_{2-x}$ materials, they have failed to show expected visible light-assisted water splitting efficiency. This was ascribed to the high concentration of the surface defects and/or oxygen vacancies, considered as an electron donor to enhance donor density and improve the charge transportation in black $TiO_2$ can also act as charge recombination centers, which eventually decrease photocatalytic activity. Therefore, a black ot reducd $TiO_2$ material with optimized properties would be highly desired for visible light photocatalysis. In this report, a new controlled magnesiothermic reduction has been developed to synthesize reduced black $TiO_{2-x}$ in the presence $H_2/Ar$ for photocatalytic $H_2$ production from methanol-water system. The material possesses an optimum band gap and band position, oxygen vacancies, and surface defects and shows significantly improved optical absorption in the visible and infrared region. The synergistic effects enable the reduced $TiO_{2-x}$ material to show an excellent hydrogen production ability along with long-term stability under the full solar wavelength range of light and visible light, respectively, in the methanol-water system in the presence of Pt as a co-catalyst. These values are superior to those of previously reported black $TiO_2$ materials. On the basis of all the results, it can be realized that the outstanding activity and stability of the reduced of $TiO_{2-x}$ NPs suggest that a balanced combination of different factors like $Ti^{3+}$, surface defects, oxygen vacancy, and recombination center is achieved along with optimized bandgap and band position during the preparation employing magnesiothermic reduction in the presence of $H_2$. The controlled magnesiothermic reduction in the presence of $H_2$ is one of the best alternative ways to produce active and stable $TiO_2-based$ photocatalyst for $H_2$ production.