• 제목/요약/키워드: Neutral current

검색결과 487건 처리시간 0.029초

대두(大豆)-근류균(根瘤菌) 공생(共生)에서 뿌리분비물(分泌物)과 화학주성(化學走性)이 숙주인식(宿主認識)에 미치는 영향(影響) (The Effect of Root Exudate and Chemotaxis on Host Recognition in Soybean-Bradyrhizobium Symbiosis)

  • 강상재;박우철
    • Current Research on Agriculture and Life Sciences
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    • 제11권
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    • pp.121-132
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    • 1993
  • 대두(大豆)-근류균(根瘤菌)의 공생(共生)에서 숙주식물(宿主植物)의 Root Exudate에 대한 근류균(根瘤菌)의 화학주성(化學走性)이 근류형성(根瘤形性)(숙주식물(宿主植物))에 미치는 영향(影響)을 밝히기 위해 연구(硏究)한 결과(結果)는 다음과 같다. 대두(大豆) Seed Lectin은 품종간(品種間) 차이(差異)가 없었으며 분자량(分子量) 120,000정도(程度)의 4개(個)의 동일(同一)한 subunit를 가지는 물질(物質)이며, Pea Seed Lectin은 분자량(分子量) 44,000정도(程度)이며 15,000과 7,000정도(程度)의 두 종류(種類)의 subunit를 가지는 물질(物質)이며 대두(大豆) lectin은 표준 lectin 항체와 침강선을 형성하였다. 그러나 완두의 lectin은 표준 lectin과 항원-항체반응이 없었으므로 두 lectin은 동일 항원이 되지 않아 서로 다른 물질이었다. 팔달의 Crude Root Exudate에 대(對)한 근류균(根瘤菌)의 화학주성(化學走性) 비(比)는 KCTC 2422는 각각(各各) 3.5이고 LPN-100은 1.4이며 LCR-101은 각각(各各) 1.4이었다. 뿌리분비물의 각 fraction에 대한 근류균의 화학주성은 중성분획이 가장 높고 양성분획이 그다음이며 음성분획이 가장 낮은 화학주성을 나타내어 각물질에 대한 근류균의 친화도에 차이가 있었다. 근류형성(根瘤形性)의 정도(程度)는 KCTC 2422의 경우(境遇)는 접종(接種)후 7日경부터 Nitrogenase Activity가 나타났으며 LCR-101는 15일 이후(以後)에 Nitrogenase Activity를 나타내었다. LPN-100은 Nitrogenase Activity가 전혀 나타나지 않아 근류균(根瘤菌)의 화학주성(化學走性)이 숙주인식과정(宿主認識過程)에 영향(影響)을 미쳤음을 확인(確認)할 수 있었다.

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Current status of Atomic and Molecular Data for Low-Temperature Plasmas

  • Yoon, Jung-Sik;Song, Mi-Young;Kwon, Deuk-Chul
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.64-64
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    • 2015
  • Control of plasma processing methodologies can only occur by obtaining a thorough understanding of the physical and chemical properties of plasmas. However, all plasma processes are currently used in the industry with an incomplete understanding of the coupled chemical and physical properties of the plasma involved. Thus, they are often 'non-predictive' and hence it is not possible to alter the manufacturing process without the risk of considerable product loss. Only a more comprehensive understanding of such processes will allow models of such plasmas to be constructed that in turn can be used to design the next generation of plasma reactors. Developing such models and gaining a detailed understanding of the physical and chemical mechanisms within plasma systems is intricately linked to our knowledge of the key interactions within the plasma and thus the status of the database for characterizing electron, ion and photon interactions with those atomic and molecular species within the plasma and knowledge of both the cross-sections and reaction rates for such collisions, both in the gaseous phase and on the surfaces of the plasma reactor. The compilation of databases required for understanding most plasmas remains inadequate. The spectroscopic database required for monitoring both technological and fusion plasmas and thence deriving fundamental quantities such as chemical composition, neutral, electron and ion temperatures is incomplete with several gaps in our knowledge of many molecular spectra, particularly for radicals and excited (vibrational and electronic) species. However, the compilation of fundamental atomic and molecular data required for such plasma databases is rarely a coherent, planned research program, instead it is a parasitic process. The plasma community is a rapacious user of atomic and molecular data but is increasingly faced with a deficit of data necessary to both interpret observations and build models that can be used to develop the next-generation plasma tools that will continue the scientific and technological progress of the late 20th and early 21st century. It is therefore necessary to both compile and curate the A&M data we do have and thence identify missing data needed by the plasma community (and other user communities). Such data may then be acquired using a mixture of benchmarking experiments and theoretical formalisms. However, equally important is the need for the scientific/technological community to recognize the need to support the value of such databases and the underlying fundamental A&M that populates them. This must be conveyed to funders who are currently attracted to more apparent high-profile projects.

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열선 CVD 증착 다결정 실리콘에서 전하를 띈 클러스터의 생성 및 증착 (Generation of Charged Clusters and their Deposition in Polycrystalline Silicon Hot-Wire Chemical Vapor Deposition)

  • 이재익;김진용;김도연;황농문
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 제17회 워크샵 및 추계학술대회
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    • pp.561-566
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    • 2005
  • Polycrystalline silicon films were deposited using hot wire CVD (HWCVD). The deposition of silicon thin films was approached by the theory of charged clusters (TCC). The TCC states that thin films grow by self-assembly of charged clusters or nanoparticles that have nucleated in the gas phase during the normal thin film process. Negatively charged clusters of a few nanometer in size were captured on a transmission electron microscopy (TEM) grid and observed by TEM. The negatively charged clusters are believed to have been generated by ion-induced nucleation on negative ions, which are produced by negative surface ionization on a tungsten hot wire. The electric current on the substrate carried by the negatively charged clusters during deposition was measured to be approximately $-2{\mu}A/cm^2$. Silicon thin films were deposited at different $SiH_4$ and $H_2$ gas mixtures and filament temperatures. The crystalline volume fraction, grain size and the growth rate of the films were measured by Raman spectroscopy, X-ray diffraction and scanning electron microscopy. The deposit ion behavior of the si1icon thin films was related to properties of the charged clusters, which were in turn controlled by the process conditions. In order to verify the effect of the charged clusters on the growth behavior, three different electric biases of -200 V, 0 V and +25 V were applied to the substrate during the process, The deposition rate at an applied bias of +25 V was greater than that at 0 V and -200 V, which means that the si1icon film deposition was the result of the deposit ion of charged clusters generated in the gas phase. The working pressures had a large effect on the growth rate dependency on the bias appled to the substrate, which indicates that pressure affects the charging ratio of neutral to negatively charged clusters. These results suggest that polycrystalline silicon thin films with high crystalline volume fraction and large grain size can be produced by control1ing the behavior of the charged clusters generated in the gas phase of a normal HWCVD reactor.

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The importance of NIR spectroscopy in the estimation of nutritional quality of grains for ruminants

  • Flinn, Peter C.
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1612-1612
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    • 2001
  • The production of grain for export and domestic use is one of Australia's most important agricultural industries, and the NIR technique has been used extensively over many years for the routine monitoring of grain quality, particularly moisture and protein content. Because most Australian grain is intended for human food production, the determinants of grain quality for livestock feed, apart from protein, have been largely ignored. However the increasing use of grain for feeding to pigs, poultry, beef cattle and dairy cows has led to an important national research project entitled “Premium Grains for Livestock”. Two of the objectives of this project are to determine the compositional and functional characteristics of grains which influence their nutritional quality for the various classes of livestock, and to adopt rapid and objective analytical tests for these quality criteria. NIR has been used in this project firstly to identify a set of grain samples from a large population of breeders' lines which showed a wide spectral variation, and hence a potentially wide variation in nutritional value. The selected samples were not only subjected to an extensive array of chemical, physical and in vitro analyses, but also were grown out to produce sufficient quantities of grain to feed to animals in vivo studies. Additional grains were also strategically selected from farms in order to include the effect of weather damage, such as rain, drought and frost. In this study to date, NIR calibrations have been derived or attempted, on both ground and whole grains, for in vivo dry matter digestibility (DMD), pepsin-cellulase dry matter disappearance, protein, fat, acid detergent fibre, neutral detergent fibre, starch, in sacco DMD and in vitro assays to simulate starch digestion in the lumen and small intestine. Results so far indicate high calibration accuracy for chemical components (SECV 0.3 to 2.6%) and very promising statistics for in vivo DMD (SECV 1.8, $R^2$ 0.93, SD 7.0, range 61.9 to 92.3, n=60). There appears to be some potential for NIR to estimate some in vitro properties, depending upon the accuracy of reference methods and appropriate sample populations. Current work is in progress to extend the range of grains with in vivo DMD values (a very laborious and expensive process) and to increase the robustness of the various NIR calibrations, with the aim of implementing uniform testing procedures for nutritional value of grains throughout Australia.

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원료배합(原料配合)이 간장의 품질(品質)과 풍미(風味)에 미치는 영향(影響) - 제1보(第一報) 원료배합(原料配合)을 달리한 고일(一)지제조중(製造中)의 효소역가(酵素力價)및 성분변화(成分變化)에 관(關)한 실험(實驗) - (Effects of the ratio of raw materials on the quality and taste of soy sauce - (1) Studies on the changes of Enzymatic activities and chemical components during Koji Preparation with various ratio of raw materials -)

  • 김용휘;김재욱
    • Applied Biological Chemistry
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    • 제4권
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    • pp.17-22
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    • 1963
  • 원료배합(原料配合)을 다리한 간장용(用) 고일(一)지의 제국중(製麴中)에 있어서와 건조(乾燥)고일(一)지의 각종효소(各種酵素) activity 및 성분(成分)의 변화(變化)를 측정(測定)하여 다음결과(結果)를 얻었다. 1. 건조(乾燥)고일(一)지는 중성부근(中性附近)(pH 6.0)에 활성(活性)을 갖는 Protease가 주체(主體)를 이루며 산성(酸性) 및 alkali성측(性側)의 Protease activity는 이보다 미약(微弱)하고 밀을 많이 배합(配合)한 구(區)일수록 산성(酸性) 및 중성측(中性側) Protease activity가 높아지는 반면(反面)에 alkali성측(性側)은 이와 반대(反對)되는 경향(傾向)을 보였다. 2. 제국중(製麴中) 각종효소(各種酵素) activity는 모두 증가(增加)되었고 밀이 많은 배합구(配合區)일수록 ${\alpha}-Amylase$는 그 activity가 높아졌다. 3. 제국중(製麴中) 전당(全糖)은 감소(減少)되었으나 직당(直糖) 및 아미노 태질소(態窒素)와 전질소(全窒素)는 증가(增加)되었다. 4. 건조(乾燥)고일(一)지에 있어서 밀이 많은 배합구(配合區)일수록 직당(直糖) 및 전당(全糖)의 함량(含量)이 많어졌으나 전질소(全窒素)는 적어졌고 아미노(態窒素)는 차이(差異)가 없었다.

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Evaluation of Different Yeast Species for Improving In vitro Fermentation of Cereal Straws

  • Wang, Zuo;He, Zhixiong;Beauchemin, Karen A.;Tang, Shaoxun;Zhou, Chuanshe;Han, Xuefeng;Wang, Min;Kang, Jinhe;Odongo, Nicholas E.;Tan, Zhiliang
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권2호
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    • pp.230-240
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    • 2016
  • Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a $3{\times}4$ factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, $0.25{\times}10^7$, $0.50{\times}10^7$, and $0.75{\times}10^7$ colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen ($NH_3$-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The $NH_3$-N concentration and $CH_4$ production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be $0.25{\times}10^7$ cfu/500 mg substrates in vitro.

Degradation Kinetics of Carbohydrate Fractions of Ruminant Feeds Using Automated Gas Production Technique

  • Seo, S.;Lee, Sang C.;Lee, S.Y.;Seo, J.G.;Ha, Jong K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권3호
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    • pp.356-364
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    • 2009
  • The current ruminant feeding models require parameterization of the digestion kinetics of carbohydrate fractions in feed ingredients to estimate the supply of nutrients from a ration. Using an automated gas production technique, statistically welldefined digestion rate of carbohydrate, including soluble carbohydrate, can be estimated in a relatively easy way. In this study, the gas production during in vitro fermentation was measured and recorded by an automated gas production system to investigate degradation kinetics of carbohydrate fractions of a wide range of ruminant feeds: corn silage, rice straw, corn, soybean hull, soybean meal, and cell mass from lysine production (CMLP). The gas production from un-fractionated, ethanol insoluble residue and neutral detergent insoluble residue of the feed samples were obtained. The gas profiles of carbohydrate fractions on the basis of the carbohydrate scheme of the Cornell Net Carbohydrate and Protein System (A, B1, B2, B3 and C) were generated using a subtraction approach. After the gas profiles were plotted with time, a curve was fitted with a single-pool exponential equation with a discrete lag to obtain kinetic parameters that can be used as inputs for modern nutritional models. The fractional degradation rate constants (Kd) of corn silage were 11.6, 25.7, 14.8 and 0.8%/h for un-fractioned, A, B1 and B2 fractions, respectively. The values were statistically well estimated, assessed by high t-value (>12.9). The Kd of carbohydrate fractions in rice straw were 4.8, 21.1, 5.7 and 0.5%/h for un-fractioned, A, B1 and B2 fractions, respectively. Although the Kd of B2 fraction was poorly defined with a t-value of 4.4, the Kd of the other fractions showed tvalues higher than 21.9. The un-fractioned corn showed the highest Kd (18.2%/h) among the feeds tested, and the Kd of A plus B1 fraction was 18.7%/h. Soybean hull had a Kd of 6.0, 29.0, 3.8 and 13.8%/h for un-fractioned, A, B1 and B2, respectively. The large Kd of fraction B2 indicated that NDF in soybean hull was easily degradable. The t-values were higher than 20 except for the B1 fraction (5.7). The estimated Kd of soybean meal was 9.6, 24.3, 5.0%/h for un-fractioned, A and B1 fractions, respectively. A small amount of gas (5.6 ml at 48 ho of incubation) was produced from fermentation of CMLP which contained little carbohydrate. In summary, the automated gas production system was satisfactory for the estimation of well defined (t-value >12) kinetic parameters and Kd of soluble carbohydrate fractions of various feedstuffs that supply mainly carbohydrate. The subtraction approach, however, should be applied with caution for some concentrates, especially those which contain a high level of crude protein since nitrogen-containing compounds can interfere with gas production.

Anticancer and Immunopotentiating Activities of Crude Polysaccharides from Pleurotus nebrodensis on Mouse Sarcoma 180

  • Cha, Youn Jeong;Alam, Nuhu;Lee, Jae Seong;Lee, Kyung Rim;Shim, Mi Ja;Lee, Min Woong;Kim, Hye Young;Shin, Pyung Gyun;Cheong, Jong Chun;Yoo, Young Bok;Lee, Tae Soo
    • Mycobiology
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    • 제40권4호
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    • pp.236-243
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    • 2012
  • Pleurotus nebrodensis is an edible and commercially available mushroom in Korea. This study was conducted in order to evaluate the anticancer and immunopotentiating activities of crude polysaccharides, extracted in methanol, neutral saline, and hot water (hereafter referred to as Fr. MeOH, Fr. NaCl, and Fr. HW, respectively) from the fruiting bodies of P. nebrodensis. ${\beta}$-Glucan and protein contents in Fr. MeOH, Fr. NaCl, and Fr. HW extracts of P. nebrodensis ranged from 23.79~36.63 g/100 g and 4.45~6.12 g/100 g, respectively. Crude polysaccharides were not cytotoxic against sarcoma 180, HT-29, NIH3T3, and RAW 264.7 cell lines at a range of $10{\sim}2,000{\mu}g/mL$. Intraperitoneal injection with crude polysaccharides resulted in a life prolongation effect of 11.76~27.06% in mice previously inoculated with sarcoma 180. Treatment with Fr. NaCl resulted in an increase in the numbers of spleen cells by 1.49 fold at the concentration of $50{\mu}g/mL$, compared with control. Fr. HW improved the immuno-potentiating activity of B lymphocytes through an increase in alkaline phosphatase activity by 1.65 fold, compared with control at $200{\mu}g/mL$. Maximum production of nitric oxide ($14.3{\mu}M$) was recorded in the Fr. NaCl fraction at $200{\mu}g/mL$. Production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-$1{\beta}$ (IL-$1{\beta}$), and interleukin-6 (IL-6) was significantly higher, compared to control, and IL-6 production was highest, in contrast to TNF-${\alpha}$, IL-$1{\beta}$, and positive control, concanavalin at the tested concentration of the various fractions. Results of the current study suggest that polysaccharides extracted from P. nebrodensis have a strong anticancer effect and may be useful as an ingredient of biopharmaceutical products for treatment of cancer.

교정력 및 외인성 전류가 고양이 치조골의 prostaglandin $E_2$에 미치는 영향에 관한 연구 (A STUDY ON THE EFFECT OF ORTHODONTIC FORCES AND EXOGENOUS ELECTRIC CURRENTS ON $PGE_2$ CONTNET OF ALVEOLAR BONE IN CATS)

  • 김종태;김중수;양원식
    • 대한치과교정학회지
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    • 제14권2호
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    • pp.203-215
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    • 1984
  • This experiment was performed to explore the effect of electric currents and orthodontic forces on bone $PGE_2$ content and orthodontic tooth movement on cats. Stainless steel electrodes were connected a power pack consisting of five miniature batteries, a transistor, and a resistor. The current $(10{\pm}2{\mu}A)$ was provided by a constant source encased in a palatal acrylic plate. In first experiment, the cathode was placed mesial to the right maxillary canine tooth and the anode was positioned distal to the tooth, Sham electrodes were placed new the left cuspid, to serve as control. Nine cats were divided into three groups evenly. Groups of three animals were treated with electric currents only-for 1, 3 and 7 days, respectively. In second experiment, electric currents and the orthodontic forces of about 80 gm were applied to the right maxillary canine, and the orthodontic forces only were applied to the left maxillary canine. 3 groups of three cats each were treated in this experiment-for 1, 3 and 7 days, respectively. Alveolar bone samples were obtained from sites of tension and compression as well as from contralateral sites. Bone samples were extracted by homogenization in $40\%$ ethanal. The supernatant partitioned twice with 2 volumes of petroleum ether to remove neutral lipids and the aqueous supernatant partitioned in ethyl acetate. After drying the solvent, $PGE_2$ was measured by radioimmunoassay technique. The obtained results were as follows. 1. Teeth treated with combined force and electricity moved faster than those treated with force alone. 2. Alveolar bone $PGE_2$ content of electric stimulation was increased at both electrodes. 3. Alveolar bone $PGE_2$ content of mechanical stimulation at compression sites was gradually increased at all time period. At tension site, $PGE_2$ content increased after 1 day of mechanical stimulation remained elevated at all time period. 4. Alveolar bone $PGE_2$ content of compression sites was increased more than that of tension sites from mechanical stimulation as well as electrical stimulation.

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기존 구강청결제를 대체할 수 있는 치아우식 예방을 위한 전기분해수 (Neutral Electrolyzed Water for Prevention of Dental Caries)

  • 이기암
    • 대한소아치과학회지
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    • 제43권3호
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    • pp.306-312
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    • 2016
  • 치아우식은 Streptococcus mutans와 S. sobrinus가 주요 원인균이며, 이를 예방하기 위해서 구강 청결제를 사용한다. 그러나 구강청결제의 부작용 및 해로움으로 인하여 소아에게 권장하기에 주위를 요한다. 전기 분해수는 물을 전극을 통해서 전류를 흘려주어 생성되는 용액으로 항균력을 갖는다. 본 연구에서는 전기 분해수를 구강 청결제 대용으로 사용하기 위해서 치아 우식원성 세균 및 바이오 필름에 대한 항균력을 조사하였다. 염화나트륨이 포함된 증류수를 백금전극을 이용하여 전기 분해수를 생성하였다. 전기분해 수소수의 물리화학적 성분을 분석하고 S. mutans 및 S. sobrinus 배양액을 원심분리하여 세균을 얻고 전기 분해수, 알코올 및 불소가 포함된 구강 청결제를 처리하고 살아있는 세균 수를 배양을 통해서 조사하였다. 또한 치아우식균의 바이오 필름을 형성시킨 후, 전기 분해수 및 구강 청결제를 처리하여 바이오 필름 제거능을 크리스탈 바이올렛 염색을 이용하여 분석하고, 바이오 필름 내 살아있는 세균수의 양은 배양을 통하여 분석하였다. 전기분해수는 높은 농도의 자유염소 (free chlorine)을 포함하고 중성 페하를 보였다. 전기 분해수는 유의하게 S. mutans 및 S. sobrinus에 대해서 항균력을 보였으며, 이 세균들의 바이오 필름 제거능 및 바이오 필름 내 세균에 대해서도 항균력을 보였다. 전기 분해수는 부유세균에 대해서 알코올이 포함된 구강청결제보다 약한 항균력을 보였지만, 바이오 필름 세균에 대해서는 더 강한 항균력을 나타냈다. 이러한 결과를 바탕으로 중성 전기 분해수는 치아우식 예방을 위한 기존 구강 청결제의 대체 용액으로 사용이 가능할 것으로 사료된다.