• Journal of Periodontal and Implant Science
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• 제46권1호
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• pp.46-56
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• 2016

Purpose: We evaluated the efficacy of a mouthwash containing potassium nitrate ($KNO_3$) as its main component, along with sodium fluoride (NaF) and cetylpyridinium chloride (CPC). The primary endpoint was the relief of dentin hypersensitivity (DH) against the cold stimuli. The effects on other DH tests and periodontal inflammation were also evaluated. Methods: We used a single-center, double-blind, placebo-controlled, randomized design. A total of 82 patients with DH (40 in the test group, 42 placebo controls) were analyzed using visual analog scales (VASs) for a cold test, a tactile test, a compressive air test, and self-reported pain during daily activities, as well as clinical parameters including plaque index, gingival index, modified sulcular bleeding index (mSBI), gingival recession, and probing depth, which were collected at baseline and after four and six weeks of mouthwash use. Results: VAS scores for cold sensations, tactile sensations, the compressive air test, and self-reported pain significantly decreased from baseline during the six weeks in both groups (P<0.01), and no significant differences between the groups were found. In male patients (10 in the test group and 7 in the control group), both groups showed significant reductions in VAS scores for the cold test over the six weeks, and greater reductions were found in the test group than in the control group between four and six weeks (P=0.01) and between baseline and six weeks (P<0.01). In addition, the mSBI in the test group significantly decreased from baseline during the six weeks (P<0.01), and the changes at four and six weeks from baseline were significantly greater in the test group compared to the control group (P=0.03 and P=0.02, respectively). Conclusions: A mouthwash containing a mixture of $KNO_3$, NaF, and CPC reduced DH and gingival inflammation, however, the efficacy was comparable to the control group.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.412-420
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• 2005

In order to investigate factors affecting the denitrification in the F-STEP PROCESS using a loess ball as support media and Pseudomonas DWC 17-8, calcining temperature, loess ball size, pH, nitrate concentration, working temperature, and inhibitor were studied in batch mode using synthetic sludge. A 5- 10 mm of loess ball (960$^{circ}$ of calcining temperature) was the most suitable for denitrification. When the initial pH was increased from 3.0 to 7.0, the removal efficiency of nitrate was increased. Specifically, at initial pH of 7.0, the maximum removal efficiency of nitrate was 5.0 mg/min. When the initial concentration of nitrate was increased from 100 to 400 mg/l, the removal efficiency of nitrate was proportional to the concentration of nitrate. The maximum removal efficiency of nitrate was 5.72 mg/min at 400 mg/l of initial concentration. When the operating temperature was increased from 10 to 30$^{circ}$, the removal efficiency of nitrate was increased from 0.76 to 6.15 mg/min, and at above 40$^{circ}$ of operating temperature, it was decreased from 4.0 to 2.0 mg/min. Among the various inhibitors, higher than 10$^{-1}$ M of sodium azide abolished this reaction completely. When the KCN concentration was above 10$^{-1}$ M, the reaction was inhibited completely. In the case of 2,4-dinitrophenol and sodium sulphide, it was inhibited at above 10$^{-2}$ M completely. For testing the various flow orders of the F-STEP PROCESS for effective denitrification using practical wastewater, continuous experiments under the optimum conditions were carried out for 60 days. Among the various processes, the PROCESS A gave the highest efficiencies of denitrification, nitrification, and total nitrogen (TN) removal with 86.5, 89.5, and $90\%$, respectively. For scale-up in the PROCESS A, real farm wastewater was used and pilot tests carried out for 90 days. The denitrification efficiency was $97.5\%$, which was increased by $12.7\%$. The efficiencies of TN removal and nitrification were 96.6 and $70.0\%$, respectively. The removal efficiency of chemical oxygen demand (COD) was $63.7\%$, which was increased by $20\%$.

• 한국축산식품학회지
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• 제40권5호
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• pp.831-843
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• 2020

This study investigated the potential for using vegetable powders as a natural replacement for sodium nitrite and their effects on the physicochemical characteristics of alternatively cured pork products. We analyzed pork products subjected to four treatments: control (0.015% sodium nitrite), Chinese cabbabe powder (CCP) treatment (0.4% Chinese cabbage powder), radish powder (RP) treatment (0.4% radish powder), and spinach powder (SP) treatment (0.4% spinach powder). Among the vegetable powders prepared in this study, SP had the highest (p<0.05) nitrate content, while CCP had the lowest (p<0.05). The cooking yields from these treatments were not significantly different from each other. However, the products with vegetable powders had higher (p<0.05) pH and thiobarbituric acid reactive substances values than the control. Pork products with vegetable powders also showed lower CIE L^⁎ values and higher CIE b^⁎ values than the nitrite-added control. RP treatment had similar (p>0.05) CIE a^⁎ values to the control, while SP treatment had the lowest (p<0.05) CIE a^⁎ values. The residual nitrite content was lower (p<0.05) in the vegetable powder added pork products than in the control, although nitrosyl hemochrome and total pigment contents in the CCP and RP treatments were similar (p>0.05) to those in the control. The control, CCP, and RP treatments showed curing efficiencies greater than 80%, indicating that CCP and RP would be promising potential replacements for sodium nitrite. The results of this study suggest that RP may be a suitable natural replacement for sodium nitrite to produce alternatively cured meat products, compared to other leafy vegetable powders.

• 한국식물병리학회지
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• 제1권1호
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• pp.44-50
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• 1985

벼 잎집무늬마름병균(Rhizoctonia solani Kuhn)의 생리적 특성을 조사하기 위하여 충북지역을 중심으로 채집 분리한 60여 Rhizoctonia 균중 균사생장 및 균핵형성에 특징이 있는 3개 균주를 선발하여 그들의 배양적 특성, 병원성 및 균핵형성에 미치는 질소원의 효과를 시험하였다. 이들 분리균주에서 PSA 배지상의 균사생장 및 균핵형성 등의 배양적 특성에 따라 선발한 3개 분리균주의 병원성은 균주간에 달랐다. 질소원으로서 Arginine, Alanine, Urea, Ammonium sulfate 및 Sodium nitrate 등은 균사생장 및 균사형성에 효과적이었으나 Cystine, Methionine, Lysine, Histidine, Tryptophan 및 Tyrosine 등은 뚜렷한 효과가 없었다. Urea, Sodium nitrate, Agrinine, Ammonium sulfate 및 Lysine 등은 질소원의 농도가 낮게 첨가된 배지에서 균사생장이 양호하였으나 Proline, Histidine, Alanine은 높은 농도 수준에서 양호하였으며 균핵형성은 모든 공시 질소원의 높은 농도 수준에서 양호하였다. 균사생장 및 균핵형성에 양호한 질소원인 Arginine, Alanine, Urea, Ammonium sulfate는 병원성도 증가시켰다. Proline 첨가 배지에서는 각 균주 공히 큰 균핵이 형성되었으며 Tryptophan을 함유한 배지에서 각 균주 모두 생육이 저조하였고, 배지의 갈변화가 가장 심하였다.

• 한국환경과학회지
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• 제16권11호
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• pp.1219-1223
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• 2007

The removal of nitrogen compounds from a wastewater is essential and it is often accomplished by bio-logical process. An aerobic nitrate-removing bacterium was isolated from a municipal sewage treatment plant and soil. On the basis of its morphological, cultural and physiological characteristics and 16S rRNA sequencing data, this strain was identified as Pseudomonas fluorescens, and named as P. fluorescens K4. The optimal conditions of the initial pH and temperature of media for its growth were $7.0{\sim}8.0$ and $30^{\circ}C$, respectively. P. fluorescens K4 was able to remove 99.9% of nitrate after 24 h in a culture. The strain could grow with a nitrate concentration up to 800 mg/l and was able to remove 99.9% of nitrate after 104 h of incubation. The optimal electron donor was sodium citrate for a nitrate removal. The strain K4 showed a capability of a complete nitrate removal when the initial C/N ratio was 1.0. An effect of the initial seed concentration was observed for a cell of 10% (v/v) for a nitrate removal. Especially P. fluorescens K4 could completely remove 200 mg/l ammonium for 3 days.

• 한국응용곤충학회지
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• 제47권4호
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• pp.479-486
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• 2008

Cordyceps militaris(번데기동충하초)와 Paecilomyces tenuipes(눈꽃동충하초)의 배양특성 및 항균활성을 비교하였다. 균사 생장 최적 배지는 C. militaris는 MCM, P. tenuipes는 YMA이며 MMM 배지 상에서는 두 균주 모두 생장이 저조하였다. 균사 생육 최적 온도는 $25^{\circ}C$이였고 C. militaris는 5회 이상 계대 시 균사 생육이 저하되었다. 적정 영양원 선발에 있어 두 균주 모두 탄소원은 단당류의 fructose, 이당류의 maltose 그리고 다당류의 dextrin이 적합하였다. 질소원은 유기태에서 C. militaris는 calcium nitrate, P. tenuipes는 sodium nitrate가 적합하였으며 무기태에서는 ammonium tartrate가 적합하였다. 항균활성은 Gram(+)의 Bacillus cereus에 대하여 C. militaris에서만 나타났다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.251-255
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• 1999

In last paper, it was suggested electrochemical polishing method using the point electrode tools. It was aimed that Machining rate in ECM using the point electrode method should be ultimately small and also high dimension accuracy and surface integrity should be fine. In this paper, the machining characteristics were investigated by using the several types of electrolyte.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.807-813
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• 2016

Two experiments were conducted assessing the effects of presence or absence of rumen protozoa and dietary nitrate addition on rumen fermentation characteristics and in vitro methane production in Brahman heifers. The first experiment assessed changes in rumen fermentation pattern and in vitro methane production post-refaunation and the second experiment investigated whether addition of nitrate to the incubation would give rise to methane mitigation additional to that contributed by defaunation. Ten Brahman heifers were progressively adapted to a diet containing 4.5% coconut oil distillate for 18 d and then all heifers were defaunated using sodium 1-(2-sulfonatooxyethoxy) dodecane (Empicol). After 15 d, the heifers were given a second dose of Empicol. Fifteen days after the second dosing, all heifers were allocated to defaunated or refaunated groups by stratified randomisation, and the experiment commenced (d 0). On d 0, an oral dose of rumen fluid collected from unrelated faunated cattle was used to inoculate 5 heifers and form a refaunated group so that the effects of re-establishment of protozoa on fermentation characteristics could be investigated. Samples of rumen fluid collected from each animal using oesophageal intubation before feeding on d 0, 7, 14, and 21 were incubated for in vitro methane production. On d 35, 2% nitrate (as $NaNO_3$) was included in in vitro incubations to test for additivity of nitrate and absence of protozoa effects on fermentation and methane production. It was concluded that increasing protozoal numbers were associated with increased methane production in refaunated heifers 7, 14, and 21 d after refaunation. Methane production rate was significantly higher from refaunated heifers than from defaunated heifers 35 d after refaunation. Concentration and proportions of major volatile fatty acids, however, were not affected by protozoal treatments. There is scope for further reducing methane output through combining defaunation and dietary nitrate as the addition of nitrate in the defaunated heifers resulted in 86% reduction in methane production in vitro.

• 한국대기환경학회지
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• 제16권6호
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• pp.573-583
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• 2000

In order to investigate the characteristics of PM(sub)2.5 in the background area, the following pollutant were measured from February 1996 to June 1999 in Kanghwa: PM(sub)2.5 mass, sulfate, nitrate, chloride, ammonium, sodium, calcium, magnesium and potassium. The mean concentration of PM(sub)2.5 mass was 25.8$\pm$1.2$\mu\textrm{g}$/㎥(range 5.18~85.74). This value was higher than the annual PM(sub)2.5 US NAAQS(15$\mu\textrm{g}$/㎥) and the total number of samples higher than the 24-h PM(sub)2.5 US NAAQS(65$\mu\textrm{g}$/㎥) was seven. PM(sub)2.5 masses also showed temporal variations both yearly and seasonally. Total water soluble ions constituted about 45% of PM(sub)2.5 miss, and sulfate, nitrate and ammonium were main components in water soluble ions. Compared with the literature data from other areas, the measured PM(sub)2.5 concentrations were relatively high.

• Applied Biological Chemistry
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• 제20권1호
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• pp.117-122
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• 1977

담배에 질산염을 청가하면 질소화합물이 증가되므로 질산염의 대체물(代替物)을 개발(開發)하기위한 실험을 한 결과 다음과 같은 결론을 얻었다. 여러가지 첨가제 중에서 $0.6{\sim}1%$의 시트르산나트륨을 첨가하는 것이 연소성 및 Tar, Nicotine의 감소효과(減少效果)가 가장 양호했다. 특히 조연제첨가(助燃濟添加)에 따른 연소성(燃燒性)과 유해성분감소효과(有害成分減少效果) 및 열특성(熱特性)에 대(對)한 다음과 같은 결과를 얻었다. 1) 연소성이 좋으면 Tar, Nicotine, Bonzpyrene Phenols, NO, $NO_2E, 등의 유해성분이 감소됐다. 2) 단엽에 첨가(添加)된 질산염과 시트르산염의 시차열분석효과(示差熱分析效果)는 시트르산염 첨가시(時) L치(値)가 가장 적고 H치(値)가 가장 컸다. 3) 순수한 질산염과 시트르산염의 시차열분석(示差熱分析)에서 전자는 발열반응(發熱反應)이 없는데 후자는 발열반응(發熱反應)이 있었다. 4) $0.6{\sim}1%$의 시트르산나트륨 첨가시(時)에 Zone A에서는 Tar생성량이 많았고 Zone B에서는 Tar 생성량이 가장 적었다. 또한 이들 담배의 연기에서는 Tar, Nicotine, Phenols, Nitrogen oxides, Benzpyrene의 함량(含量)이 적었으며 연소성이 향상되었다.