• 한국수산과학회지
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• 제42권3호
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• pp.276-283
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• 2009

Enrichment in nutrients coming from urban sewage outfalls can lead to eutrophication in coastal areas, which can also change the species composition and community structure of macro algal communities. We investigated the structure of the macro algal community within three rocky shores in order to assess any possible differences in their characteristics. Site 1 was located near Tongyeong city's sewage outfall, Site 2 was located near a public beach area, and Site 3 faced open channel of the Ocean. All three sites were located within the same stretch of the coast, where Site 2 was located between sites 1 and 3. We measured the nutrient concentration in water and the tissue nitrogen content in macro algae samples. Nutrients in the water column surrounding site 1 were high in ammonium ($30.2\pm1.8{\mu}M$), nitrate ($26.2{\pm}0.1{\mu}M$), and phosphate ($2.7{\pm}0.1{\mu}M$) content, and were characterized by low numbers of macroalgal species and species and a low species diversity index. In contrast, site 3 exhibited relatively low nutrient concentration levels and a high number of macroalgal species and a high species diversity index. Comparative analysis showed that the tissue nitrogen content of macroalgae were significantly (P<0.05) affected by the nutrient concentration in the water column. The tissue nitrogen content of green algae within site 1 was higher than the others sites. However, the tissue nitrogen content of brown algae was similar at all three sites. Thus, the tissue nitrogen content of macro algae and the macro algal community structure of intertidal rocky shores were dependent on location and the performance of macroalgal communities was dependent on water quality.

• 한국환경과학회지
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• 제22권10호
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• pp.1345-1351
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• 2013

Leaf characteristics of two representative deciduous-tree species in Korean peninsula were compared to assess directional ridge effect on leaf traits of both species. Leaf mass per unit area (LMA) of Rhododendron schilippenbachii in south-facing ridge slope was significantly higher than that in north-facing ridge slope, while Quercus mongolica did not change LMA. Leaf mass of Q. mongolica was increased depending on leaf size irrespective of slope. However, leaf mass of R. schilippenbachii changed differently in responding to expansion of leaf area between both slopes resulting from retardation of leaf expansion in south-facing slope. R. schilippenbachii showed higher leaf nitrogen concentration per unit area (LNCA) in south-facing slope than that in north-facing slope, while Q. mongolica indicated no difference in LNCA between southand north-facing slopes. However, both species revealed no significant difference in leaf nitrogen concentration per unit mass (LNCM) between south- and north-facing slopes. LNCA of Q. mongolica was about two times higher than that of R. schilippenbachii. These results indicate that there is a difference in leaf characteristics including leaf thickness and nitrogen allocation between Q. mongolica and R. schilippenbachii, suggesting the difference of plasticity.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 총회 및 춘계학술발표회
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• pp.195-198
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• 2002

Nitrogen pollution in urban and rural groundwater is a common problem and poses a major threat to drinking water supplies based on groundwater. In this work, the kinetics of nitrification-denitrification coupled reactions are modeled and new reaction modules for the RT3D code (Clement, 1997) describing the fate and transport nitrogen species, dissolved oxygen, dissolved organic carbon, and biomass are developed. The proposed nitrogen transformations and transport model showed very good match with results of a conceptual model. However, the model simulation results for the major reactive species should be tested for validation using experimental and field data.

• Journal of Ceramic Processing Research
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• 제19권6호
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• pp.499-503
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• 2018

In this paper, cobalt embedded in nitrogen and sulfur co-doped carbon nanotubes (CoNSTs) were synthesized for oxygen reduction reaction (ORR) catalysts. The CoNSTs were prepared through a facile heat treatment method without any templates. Different amounts of the metal salt were employed to examine the physicochemical and electrochemical properties of the CoNSTs. The CoNSTs showed the bamboo-like tube morphology with the encased Co nanoparticles in the tubes. Through the x-ray photoelectron spectroscopy analysis, the catalysts exhibited different chemical states of the nitrogen and sulfur species. As a result, the CoNST performed high activity toward the ORR in an acidic condition with the onset potential of 0.863 V (vs. reversible hydrogen electrode). It was clearly demonstrated from the electrochemical characterizations that the quality of the nitrogen and sulfur species significantly influences the ORR activity rather than the total amount of the dopants.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.230.2-230.2
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• 2016

A new approach for antimicrobial is based on the overproduction of reactive nitrogen species (RNS), especially; nitric oxide (NO) and peroxinitrite ($ONOO^-$-) are important factors to deactivate the bacteria. Recently, non-thermal atmospheric pressure plasma jet (APPJ) has been frequently used in the field of microbial sterilization through the generation of different kinds of RNS/ROS species. However, in previous study we showed APPJ has combine effects ROS/RNS on bacterial sterilization. It is not still clear whether this bacterial killing effect has been done through ROS or RNS. We need to further investigate separate effect of ROS and RNS on bacterial sterilization. Hence, in this work, we have enhanced NO production, especially; by applying a 1% of HNO3 vapour to the N2 based APPJ. In comparison with nitrogen plasma with inclusion of water vapour plasma, it has been shown that nitrogen plasma with inclusion of 1% of HNO3 vapour has higher efficiency in killing the E. coli and different type of cancer cell through the high production of NO. We also investigate the enhancement of NO species both in atmosphere by emission spectrum and inside the solution by ultraviolet absorption spectroscopy. Moreover, qPCR analysis of oxidative stress mRNA shows higher gene expression. It is noted that 1% of HNO3 vapour plasma generates high amount of NO for killing bacteria and cancer cell killing.

• Molecules and Cells
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• 제39권1호
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• pp.60-64
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• 2016

Inflammation is a pathophysiological response to infection or tissue damage during which high levels of reactive oxygen and nitrogen species are produced by phagocytes to kill microorganisms. Reactive oxygen and nitrogen species serve also in the complex regulation of inflammatory processes. Recently, it has been proposed that peroxiredoxins may play key roles in innate immunity and inflammation. Indeed, peroxiredoxins are evolutionarily conserved peroxidases able to reduce, with high rate constants, hydrogen peroxide, alkyl hydroperoxides and peroxynitrite which are generated during inflammation. In this minireview, we point out different possible roles of peroxiredoxins during inflammatory processes such as cytoprotective enzymes against oxidative stress, modulators of redox signaling, and extracellular pathogen- or damage-associated molecular patterns. A better understanding of peroxiredoxin functions in inflammation could lead to the discovery of new therapeutic targets.

• Mycobiology
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• 제33권1호
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• pp.23-29
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• 2005

The effects of different concentrations of three amino acids as carbon and or nitrogen sources on mycelial dry weights, changes in pH values of synthetic medium, ammonia secretion and extracellular protease activity by three zoosporic fungi, pathogens of fish and shellfish, were studied. As compared with the control, the addition of isoleucine and aspartic acid as nitrogen sources were generally stimulative for mycelial dry weight production whereas phenylalanine was inhibitory irrespective to the tested fungal species. When amino acids served as carbon and nitrogen sources, the mycelial dry weights of the three fungi were increased (mostly non-significantly) relative to untreated control but weights were decreased as the concentrations of the three amino acids raised. The addition of individual amino acids as carbon and nitrogen sources to the medium significantly increased pH values of the medium comparable to the control. The addition of each of the three amino acids as carbon and nitrogen sources to the medium significantly induced ammonia secretion by the three species of zoosporic fungi. Ammonia secretion in synthetic medium amended with amino acids as nitrogen source raised by the three zoosporic fungi relative to untreated control except in case of Achlya racemosa treated with isoleucine. Extracellular protease activity was almost promoted in case of Achlya proliferoides and Saprolegnia furcata cultures treated with isoleucine and aspartic acid individually in presence of glucose and vice versa in case of phenylalanine. However, extracellular protease activity of A. racemosa decreased compared with the control at various concentrations of isoleucine and both phenylalanine and aspartic acid assumed inconsistent effects. Extracellular protease activity of the three zoosporic fungi in the medium devoid of glucose varied depending upon zoosporic fungal species, the tested amino acid and the applied concentrations. The values of protease activity were approximately less two folds than that obtained in presence of glucose.

• Journal of Forest and Environmental Science
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• 제38권1호
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• pp.21-37
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• 2022

The present study was carried out to evaluate the chemical properties of soil in relation to forest structure and composition at different altitudes (900-2,600 m asl) in a part of Western Himalaya. The composite soil samples were taken from three (viz. upper, middle and lower) depths. The soils of the whole study area were acidic in nature (pH=4.90-5.51). Contents of Nitrogen (N), Phosphorus (P), Potassium (K), Carbon (C) and soil organic matter (SOM) showed much fluctuation during different seasons of year. Nitrogen content showed significant positive correlations with altitude (r=0.924, p<0.05) and different community parameters like species diversity (r=0.892, p<0.01) and species richness (r=0.941, p<0.05). Phosphorus exhibited direct correlations with carbon (r=0.637) while weak negative correlations with different community parameters like species richness & diversity, total basal cover (TBC), density and canopy cover. Carbon content and hence SOM showed direct correlations with Nitrogen (r=0.821, p<0.01); Phosphorus (r=0.637, ns) and Potassium (r=0.540, ns). But no significant relationship was observed between K content and species richness (p=0.30, r=-0.504); between K content and species diversity (p=0.14, r=-0.672); between P content and species diversity (p=0.29, r=-0.513) and species richness (p=0.23, r=-0.575). Among the different soil nutrients, only N showed a significant positive correlation with altitude while all others exhibited negative (but non-significant) correlation with it. The study revealed that the chemical properties affect and are reciprocally affected by forest structure and composition and that N rich soils of higher altitudes are best for the growth and development of forests.

• 미생물학회지
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• 제13권1호
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• pp.24-30
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• 1975

this work was designed to study the species belonging to Family Rhodospirillaceae in Korea. The species of Rhodopseudomonas palustris and R. gelatinosa were isolated and identified. The utilization of various substrates such as malate, succinate, citrate, pyruvate, propionate and acetate were tested with isolated KS 007 and KS o16. Though there were some differences according to nitrogen source in media it was thought that he intermediates of TCA cycle were comparatively good substrates, Also it was confirmed that isolated strains have the ability of nitrogen fixation.

• Journal of Plant Biology
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• 제29권2호
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• pp.109-115
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• 1986

Actinorhizal plants being capable of fixing atmospheric nitrogen in symbiotic association with Frankia were surveyed for their root nodules, and the root nodules were collected for further studies. Three species of Alnus and Elaeagnus (A. hirsuta, a. firma, A. japonica; E. glabra, e. umbellata, E. macrophylla) and one species of Myrica (M. rubura) were confirmed to bear the root nodules of typical external shape. Morphological studies using light microscope and scanning electron microscope revealed the presence of vesicle clusters in the cortex region of the root. Two tentative endophyte colonies were isolated from the root nodule of A. hirsuta.