• Advances in nano research
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• 제14권4호
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• pp.391-397
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• 2023

This manuscript describes the one-step eco-friendly green fabrication of silver nanoparticles (AgNPs) through the in-situ bio-reduction of an aqueous solution of silver nitrate using Syzygium aromaticum leaf extract. UV-vis spectroscopy shows a characteristic SPR peak around 442 nm. FTIR spectroscopy showed that the AgNPs were capped with bioactive phyto-molecules. TEM images revealed oval and spherical particles with a mean diameter of ~12.6 nm. XRD analysis revealed crystalline and face-cantered cubic AgNPs. The phytosynthesized AgNPs showed broad-spectrum anti-microbial activity against two foodborne pathogenic bacteria, Listeria monocytogenes and Staphylococcus aureus. The AgNPs showed a prominent ability to inhibit biofilms formed by L. monocytogenes and S. aureus in laboratory conditions through a crystal violet assay. The results suggest that the AgNPs could be a novel nanotool to develop effective antimicrobial and anti-biofilm agents in food preservation.

• Restorative Dentistry and Endodontics
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• 제33권1호
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• pp.9-19
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• 2008

본 연구의 목적은 두 가지 실험용 소수성 상아질 접착제와 전통적인 3-step 상아질 접착제의 nanoleakage 양상을 load cycling 전, 후에 비교하여 상아질 접착제의 내구성을 예측해 보고자 하는 것이다. 두 가지 실험용 소수성 상아질 접착제 즉, 에탄을 포함 상아질 접착제, 메탄을 포함 상아질 접착제를 만들었다. 대구치 30개의 치관부 3분의 1을 절단하고 임의로 3군으로 나누어 각각 Scotchbond Multi-Purpose (3M ESPE, St. Paul, MN, USA), 에탄올 포함 상아질 접착제 및 메탄을 포함 상아질 접착제를 사용하여 상아질 접착 후, 복합레진으로 치관부를 수복하였다. 각각의 접착 시스템을 Load cycling 여부에 따라 두 군으로 나누고 각각의 치아를 접착 계면에 수직으로, 약 2.0 mm의 두께가 되도록 절단하여 치아마다 2개의 시편을 얻어 각 군 당10개의 시편을 얻었다. 시편을 50 % ammoniacal silver nitrate를 이용하여 염색한 후 주사전자현미경을 이용하여 혼성층의 nanoleakage를 관찰하였다. 은 침착의 분포는 image analysis software (Scion Image Beta 4.03, Scion Corp., Frederick, MD, USA)를 이용하여 gray value로 계산하였고 이 원분산 분석법으로 통계처리 하였다. 3종의 상아질 접착제에서 모두 nanoleakage가 관찰되었으나, 에탄올 포함 상아질 접착제와 메탄을 포함 상아질 접착제에서 Scotchbond Multi-Purpose 보다 적은 양의 nanoleakage 가 관찰되었다 (p < .0001). 각각의 상아질 접착제에서 load cycling에 따른 nanoleakage 양상의 변화는 관찰되지 않았다. 이상의 결과에서 친수성기를 줄이고 소수성기를 극대화 한 실험용 상아질 접착제가 접착 계면의 내구성 향상에 도움을 줄 수 있을 것으로 사료된다.

• 대한소아치과학회지
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• 제35권3호
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• pp.389-398
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• 2008

본 연구는 상아질 접착계면에서 collagenase와 esterase가 접착강도와 극미세누출에 미치는 영향을 살펴보기 위해 시행하였다. 발치된 치아의 교합면 상아질에 Single Bond 2(SB)와 Clearfil SE bond(SE)를 사용하여 상아질-레진 접착시편을 제작하고, 시편을 인산완충용액(PBS)에 24시간(I), 또는 PBS(II), collagenase 용액(III), esterase 용액(IV)에 4주간 보관 한 후 질산은 용액으로 염색하였다. 시편의 미세인장접착강도(${\mu}TBS$)와 질산은 침투 면적을 측정하여 다음과 같은 결과를 얻었다. 1. SB군의 접착강도가 $II{\sim}IV$군에서 SE군에 비해 낮은 값을 나타내었다(p<0.05). SB군은 $II{\sim}IV$군의 접착강도가 I군에 비해 낮은 값을 보였으나(p<0.05), SE군의 접착강도는 $I{\sim}IV$군간에 차이를 보이지 않았다(p>0.05). 2. SB군의 질산은 침투 면적이 SE군에 비해 높았으며(p<0.05), SB군과 SE군에서 질산은 침투 면적은 $I{\sim}IV$군간에 차이를 보이지 않았다(p>0.05). 3. 접착강도와 질산은 침투 면적은 SE군의 I, II, III군에서 음의 상관관계를 보였다(p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제6권3호
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• pp.441-445
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• 1993

Ten bacteriocin-producing Enterococcus faecium strains with urease activity ($1.10-6.2nkat.mL^{-1}$) were isolated from the rumen of 2-8 weeks old calves. All strains were resistant aginst disodium arsenate at a minimal inhibition concentration - MIC $5g.L^{-1}$ and mercury chloride ($MIC=10-20mg.L^{-1}$). Eight strains were resistant against silver nitrate ($MIC=40-50mg.L^{-1}$) and three against antibiotics used. The resistance against six antibiotics was found in A23 strain. Values of adherence index ranged from 5.02 to 20.4 enterococci adhered per one epithelial cell of rumen wall. All isolates produced bacteriocins which inhibited the growth at least of one of five indicator organisms. The EF1 strain with a good affinity to the epithelial cell ($15.2{\pm}1.2$) produced bacteriocin substance with antimicrobial activity against grampositive and gramnegative indicator bacteria.

• 환경생물
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• 제23권4호
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• pp.374-378
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• 2005

A diffusion - precipitation method was developed to determine acid volatile sulfide (AVS) concentrations in freshwater sediments. This method uses silver nitrate as a sulfide trap solution and the concentration of trapped sulfide is determined gravimetrically. The proposed diffusion - precipitation method is more rapid and less expensive than previously developed purge- and - trap methods. Spiked sodium sulfide recoveries using this method $(97\~120\%)$ were similar with a previously developed diffusion - absorption method $(93.8\~115\%)$ and about $20\%$ greater than a previously developed purge-and-trap method $(74.6\~105\%)$. Detection limit of this method $(0.1\;{\mu}mole\;S\;g^{-l})$ was comparable with that of diffusion-absorption method $(0.06\;{\mu}mole\;S\;g^{-l})$ and purge-and-trap method $(0.05\~0.5\;{\mu}mole\;S\;g^{-l})$.

• Journal of Nutrition and Health
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• 제7권1호
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• pp.25-29
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• 1974

In order to help food habits of Korean, major foods of side dishes in Korean foods were analyzed by Mohr's Silver Nitrate Method. The kinds of foods were Kanchang (Sa)Sauce) Kochuchaag(Redpepperbean paste), Doeuchang(Soy bean Paste) and Kimchies, and selected into 3 areas in Korea; Seoul (city area), Kyung Puk Province (Fishery area) and Chun-Puk Province (Farming area). The results are as follows; Average NaCl content of Kan-chang is 26.04g/dl ranged from 24.27 to 28.22g/dl and among them Farming area is the highest content. In Ko-chu-chang, average content is 11.36g% ranged from 10.77 to 11.60g%. Doen-chang has an average 15.89% ranged from 13.28 to 18.54g% and in Kimckies they were resulted 3.36g%.

• 통합자연과학논문집
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• 제6권3호
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• pp.170-175
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• 2013

Silicon nanowires were detached and obtained from silicon nanowire arrays on silicon substrate using a ultrasono-method. Silicon nanowire arrays on silicon substrate were prepared with an electroless metal assisted etching of p-type silicon. The etching solution was an aqueous HF solution containing silver nitrate. SEM observation shows that well-aligned nanowire arrays perpendicular to the surface of the silicon substrate were produced. After sonication of silicon nanowire array, an individual silicon nanowire was confirmed by FESEM. Optical characteristics of SiNWs were measured by FT-IR spectroscopy. The surface of SiNWs are terminated with hydrogen.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.203-205
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• 2002

Light is an environmental signal that regulates photomovement and main energy source of photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). Syn6803 is a popular model system for study of plant functional genomics. In this report, we adopted 2D gel based proteomics study to investigate proteins related with the light absorption and photo-protection in Syn6803. More than 700 proteins were detected on the SDS-gels stained with silver nitrate. Several proteins showing different expression level under various light conditions were identified with MALDI-TOF Mass spectrometry. As a comparison, we also conducted ICAT-based proteome study using WT and cphl (cyanobacterial phytochrome 1) mutant. A cphl deletion led to changes in the expression of proteins involved in translation, photosynthesis including photosystem and CO2 fixation, and cellular regulation. We are currently involved in TAP-tagging method to study protein-protein interactions in search for the molecular component involved in the light signal transduction of Syn6803 photomovement.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.27-28
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• 2018

Deterioration of reinforced concrete structures due to salt corrosion is a phenomenon that can be easily seen, and the main reason for deterioration is chloride ion. Therefore, researches are actively conducted to control chlorine ion penetration worldwide. The purpose of this study is to evaluate the chloride ion fixation capacity of Portland cement paste containing Hydrotalcite. For this purpose, cement paste containing 0%, 2.5%, and 5% of Hydrotalcite was sealed and cured for 28 days, and the cured cement paste was crushed. Chloride ion solution was prepared at a concentration of 0.5M using NaCl, and the powdered cement paste was reacted for a specific time in aqueous chloride ion solution. After the reaction, the concentration of the chloride ion aqueous solution was measured using a silver nitrate potentiometric titrator, and the reacted cement paste was analyzed using XRD and FT-IR.

• 한국동물학회지
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• 제9권1호
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• pp.39-45
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• 1966

백서(Rattus horvegicus var. albinus) 50 두를 키우며 자성백서의 발정을 질정도말법으로 확인하여 임신케 한후 각 단계별로 80개의 배를 얻었다. 고정액은 Bouin's solution 과 Carnoy's solution II였으며 표본은 5-7$\mu$의 두께로 연속절편을 만들었다. 염색은 Delafield's hematoxylin 과 eosin-Y의 이중염색법과 신경섬유를 관찰하기 위하여 Ramoney Cajal's silver-nitrate method를 사용하였다. 실험결과는 안와가 stage 17에서 나타났고 안포가 stage 18에서 형성되었다. 심안포가 stage 19에서 형성되었고 망막판과 수정체판이 stage 21에서 형성되었으며 체표외배엽과 접촉하고 있는 안포의 부분은 stage 22(A)에서 안배를 형성하기 위해 몰입되었다. state 22 (B)에서 수정체공은 아직 열려 있었고 stage 23(A)에서 색소립이 망막의 색소층에 나타났고 수정체공이 닫혀졌다. 수정체와는 stage 23(B)에서 체표외배엽으로부터 분리되었고 수정체 내벽세포의 신장이 stage23(C)에서 시작되었다. 수정체강은 stage 25에서 수정체섬유에 의해서 인멸되었고 stage 26에서 홍채가 형성되기 시작하였다.