• 한국물환경학회지
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• 제30권1호
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• pp.1-7
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• 2014

The purpose of this study was to investigate the nitrification characteristics of biological aerated filter (BAF) packed with ceramic media, especially focusing on nitrite build-up during nitrification. When increasing the nitrogen load above $1.63kgNH_4{^+}-N/m^3{\cdot}d$, ammonium removal efficiency decreased to less than 60% and the nitrite ratio ($NO_2{^-}-N/NO_x-N$) of higher than 75% was achieved due to the inhibitory free ammonia (FA, $NH_3-N$) concentration and oxygen limitation. FA inhibition, however, is not recommended strategy to promote nitrite build-up since FA concentration in the reactor is coupled with decreased ammonium removal efficiency. Nitrite ratio in the effluent was also affected by aeration rate and influent ammonium concentration. Ammonium oxidation was enhanced at a higher aeration rate regardless of influent ammonium concentration but, the nitrite ratio was dependent on both aeration rate and influent ammonium concentration. While a higher nitrite ratio was obtained when BAFs were fed with $50mgNH_4{^+}-N/L$ of influent, the nitrite ratio significantly decreased for a greater influent concentration of $200-300mgNH_4{^+}-N/L$. Taken together, aeration rate, influent ammonium concentration and FA concentrations kept in the BAF were found to be critical variables for nitrite accumulation in the BAF system.

• 한국식품위생안전성학회지
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• 제15권2호
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• pp.101-107
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• 2000

우리나라 고유의 염건품인 굴비를 섭취하였을 때 체내에서 생성되는 NA를 예측하기 위해서 인공타액과 위액을 혼합하여 37。C에서 2시간동안 배양한 굴비의 인공소화물로부터 NA를 분석하였고, 동시에 nitrite, thiocyanate 및 ascorbic acid가 공존할 경우 NA생성에 미치는 영향을 실험하였다. 굴비시료에 인공타액과 위액을 가하여 소화시킨 인공소화물에서는 N-nitrosodimethylamine(NDMA)이 전혀 검출되지 않았으나, nitrite농도를 증가시킬수록 이에 비례하여 NDMA의 생성은 증가하였다. 굴비시료에 thiocyanate를 농도별(0∼6.4 mM)로 첨가하여 인공소화 시킨 결과 nitrite첨가량에 비례하여 NDMA 생성이 증가되었으나, 고농도의 nitrite(100 mM)를 함유한 시료에 thiocyanate를 8mM이상 첨가한 경우에는 뚜렷한 촉매효과를 나타내지 않았다. 반면에 10g의 굴비시료에 ascorbic acid를 농도별로 첨가한 인공 소화물에서 NDMA생성억제를 실험한 결과 nitrite농도가 0.5 및 1 mM인 경우에는 NDMA의 생성을 억제시키지 못하였으나 nitrite와 ascorbic acid의 농도가 높아짐에 따라 비례적으로 NDMA 생성억제도 뛰어났다.

• 한국어병학회지
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• 제20권3호
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• pp.291-297
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• 2007

양식 뱀장어(Anguilla japonica)의 사육 중 발생하는 아질산중독에 대한 aspirin(ASA)의 효과를 알아보기 위하여 인위적으로 메트헤모글로빈혈증을 유발시킨 다음 ASA, 식염, 식염과 ASA 및 1/2 환수시키고 24시간 동안 사육하였다. 각 처리군의 뱀장어에서 동맥구에서 말초혈액을 채취하여 헤마토크리트치, 혈구의 형태 변화, 혈장 중의 아질산의 농도 및 메트헤모글로빈의 농도와 아가미의 병리조직학적 변화를 조사하였다. ASA약욕군이 헤마토크리트치가 높고, 혈장중의 아질산 농도와 메트헤모글로빈의 농도가 낮을 뿐만 아니라 적혈구의 형태도 정상어와 유사하였다. 또한 아가미의 병리조직변화도 다른 처리군에서는 상피세포의 증생과 유착 및 모세혈관의 충혈 등이 확인되었지만, ASA처리군에서는 발견할 수 없었다. 이러한 결과로부터 ASA의 약욕이 뱀장어의 아질산의 독성저하에 효과적일 것으로 판단되었다.

• 한국어병학회지
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• 제26권1호
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• pp.1-9
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• 2013

The acute toxicity and sublethal effects of nitrite on the dark-banded rockfish, Sebastes inermis (mean body weight: $83.3{\pm}7.2$ g), were studied under static conditions for a period of 96 h. The acute toxicity of nitrite was at the 50% lethal concentration ($LC_{50}$) of 700 mg/L. The sublethal effects on selected hematological parameters of the dark-banded rockfish, such as its osmolality, hematocrit, cortisol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST), were measured after 0, 6, 12, 24, 48, 72, and 96 h of exposure to 0, 50, 100, 200, 400, or 700 mg/L nitrite. Sublethal nitrite caused a progressive reduction in the hematocrit of the fish, depending on the nitrite concentration and the exposure period. Exposure to 100-700 mg/L nitrite for 96 h caused a reduction in the hematocrit and an increase in cortisol, ALT, and AST compared with the control levels. Abnormal ultrastructural changes in the gills and liver tissues were observed in fish exposed to 700 mg/L nitrite for up to 96 h compared with the control tissues. Ultrastructural changes included atrophic gill mitochondria and hepatocytes that developed smooth endoplasmic reticulum and atrophic mitochondria. Although no rockfish mortality occurred at 500 mg/L nitrite, all the hematological parameters examined responded adversely to a nitrite dose of 200 mg/L for 96 h. These results show that although the acute toxic concentration of nitrite for the dark-banded rockfish is > 700 mg/L, sublethal concentrations of nitrite also negatively affect its hematological parameters.

• 한국어병학회지
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• 제36권2호
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• pp.361-368
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• 2023

Juveniles of the white leg shrimp Litopenaeus vannamei (Weight 0.18±0.08 g) were exposed to nitrite-N at 0, 25, 50, 100, 200 and 400 mg/L for 72 hours, and the lethal concentration, heamolymph and genes regulation were evaluated. The lethal concentration 50 (LC₅₀) of L. vannamei exposed to nitrite-N was 141.2 mg/L at 25℃ and 33 psu. In Total protein, total cholesterol, and BUN in heamolymph temporarily increased after the start of the experiment and then stabilized, but glucose, an indicator of stress, decreased over time in the entire experimental group, and creatines, an indicator of tissue damage, decreased with nitrite concentration until the first 12 hours. The genes of immune-related showed that masquerade-like serine proteinase(Mas) increased at 50 and 400 ppm for 24 hours, and then gradually decreased depending on concentration. In the case of prophenoloxidase, it was highest at 400 ppm for 40 hours, and other genes(Ras-related nuclear protein, Masquerade-like serine proteinase, proPO-activating enzyme) showed a response for 48 hours and then gradually decreased. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of L. vannamei.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.282-285
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• 2001

질산화 생물여과 시스템 내 생물막 안에 존재하는 ammonia oxidizers 및 nitrite oxidizers의 군집 구조 및 공간적 분포를 조사하였다. FISH 분석 결과 생물막 내 숫적으로 우점종을 이루는 미생물은 ammonia oxidizer인 Nitrosomonas spp.로 나타났으며 nitrite oxidizer 인 Nilrospira spp.에 비해 3 ${\sim}$ 5 정도 더 많이 존재하였다. 이는 실협 기간동안 완전한 질산화를 보였지만 반응기가 2 년 이상 nitrite 축적을 위해 높은 free ammonia 농도 빛 낮은 용존 산소 상태에서 운선되어 nitrite oxidizers에 저해를 주었기 때문인 것으로 사료된다. FISH와 결합된 CLSM 관찰 결과 생물막 전체에 걸쳐 ammonia oxidizer가 분포하는 반면 안쪽으로 갈수록 nitrite oxidizers가 분포함을 보였다. 이는 폐수의 ammonium 을 생물막 내 ammon ia oxidizer가 먼저 nitrite로 산화시키고 이를 nitrite oxidizers가 곧바로 nitrate로 산화시키기 때문이다.

• 대한환경공학회지
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• 제22권10호
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• pp.1789-1797
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• 2000

질산화에 요구되는 산소량과 탈질소화에 요구되는 탄소원의 양을 감소시킬 수 있는 암모니아성 질소의 아질산성 질소로의 부분적 질산화 반응을 유도하기 위해 생물막 반응기를 이용하여 고농도 암모니아성 질소를 함유하고 있는 혐기성 소화슬러지 탈수여액을 대상으로 알칼리도/암모니아성 질소의 농도비, pH, FA(free ammonia), 온도변화에 따른 아질산성 질소의 축적현상에 대한 연구를 수행하였다. 실험결과 유입수의 알칼리도/암모니아성 질소의 농도비를 증가시킴에 따라 유출수의 아질산성 질소의 축적도 증가하였으며, 이는 알칼리도의 농도가 증가함에 따라 반응기내의 pH가 높게 유지됨으로서 FA의 농도가 증가하게 되어 Nitrobacter의 성장을 선택적으로 저해시키기 때문인 것으로 판단된다. 일정한 알칼리도/암모니아성 질소의 농도비 조건에서 온도가 증가할수록 아질산성 질소의 축적도 증가하였다.

• 생물정신의학
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• 제11권1호
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• pp.33-39
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• 2004

Objective:Nitric oxide(NO) has been known to be associated with tolerance and preference to alcohol. It has also been known to affect various alcohol drinking behavior, alcohol withdrawal symptoms and alcohol- induced brain damage. The purpose of this study was to determine the difference, among alcohol dependence group, alcohol drinking group and abstinence group, in serum concentration of nitrite, a stable metabolite of NO, and it's relationship to clinical and biochemical markers of alcoholism. Methods:Forty subjects diagnosed as alcohol dependence according to DSM-IV diagnostic criteria were evaluated for the clinical characteristics and biochemical markers of alcohol dependence including nitrite with their CIWA-Ar scores checked just after admission. Thirty-nine healthy controls were also evaluated, divided into twenty-three alcohol drinking group and sixteen abstinence group. Clinical characteristics were evaluated by CIWA-Ar, CAGE and AUDIT questionnaires. Aspartate aminotransferase(AST), alanine aminotransferase (ALT), gamma glutamyltransferase(GGT) and mean corpuscular volume(MCV) were used as the biochemical markers of alcohol dependence. Serum nitrite concentrations were measured by Griess reaction. Results:1) The concentrations of nitrite in alcohol dependence patients were not different from those in the control subjects. 2) There were no significant association between the nitrite concentrations and the CIWA-Ar scores in alcohol dependence patients. 3) Nitrites are significantly increased in alcohol dependence group and alcohol drinking group compared with abstinence group. Conclusions:These findings suggest that serum nitrite concentration has no relation with alcohol withdrawal symptoms, but alcohol drinking increases serum nitrite concentration influenced by general condition of the body.

• 생명과학회지
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• 제11권4호
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• pp.321-327
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• 2001

The purpose of this study was to investigate the nitrite scavenging activity of the ethanol and water extracts obtained from Hizikia fusiforme and Sargassum fulvelum using sodium nitrite under different pH conditions. The nitrite scavenging activity was appeared in all the extracts examined and it showed the highest value at pH 1.2 The ethanol extract of Hizikia fusiforme provided higher activity than the water extract of that. Ohterwise, the nitrite scavenging activity of Sargassum fulvelum ethanol extract was similar to that Sargassum fulvelum water extract. There was significant difference among concentration of extracts Hizikia fusiforme and Sargassum fulvelum. Also, nitrite scavenging activity of the extracts Hizikia fusiforme and Sargassum fulvelum decreased with higher pH condition. In addition, the activity was increaed with higher concentration of extracts Hizikia fusiforme and Sargassum fulvelum in the course of reaction time 30 minute to 3 hour.

• 한국어병학회지
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• 제36권2호
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• pp.349-360
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• 2023

Common carp (Cyprinus carpio) (Weight 23.05 ± 6.98 g, Length 12.65 ± 1.38 cm) were exposed to waterborne nitrite at 0, 50, 100, 200, 400 and 800 mg NO₂ ^-/L for 96 hours. The lethal concentration 50 (LC₅₀) of C. carpio exposed to waterborne nitrite was 398.6 mg NO₂ ^-/L. Hemoglobin, hematocrit and RBC count were significantly decreased by waterborne nitrite exposure. The MCV (mean mean corpuscular volume) (µl), MCH (mean corpuscular hemoglobin) (pg) and MCHC (mean corpuscular hemoglobin concentration) (%) were significantly increased. The inorganic component, plasma calcium, was significantly increased, and the organic components such as plasma cholesterol and total protein were significantly increased showing a similar tendency with calcium. In enzymatic components, the AST and ALT were also significantly increased by nitrite exposure. The results of this study indicate that exposure to nitrite can affect the survival and hematological physiology of C. carpio.